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![Julia Lawall](/assets/img/avatar_default.png)
Spelling mistake (triple letters) in comment. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Daniel Müller <deso@posteo.net> Link: https://lore.kernel.org/bpf/20220521111145.81697-71-Julia.Lawall@inria.fr
13202 lines
345 KiB
C
13202 lines
345 KiB
C
// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
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/*
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* Common eBPF ELF object loading operations.
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*
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* Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
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* Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
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* Copyright (C) 2015 Huawei Inc.
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* Copyright (C) 2017 Nicira, Inc.
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* Copyright (C) 2019 Isovalent, Inc.
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*/
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#ifndef _GNU_SOURCE
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#define _GNU_SOURCE
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#endif
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#include <stdlib.h>
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#include <stdio.h>
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#include <stdarg.h>
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#include <libgen.h>
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#include <inttypes.h>
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#include <limits.h>
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#include <string.h>
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#include <unistd.h>
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#include <endian.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <ctype.h>
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#include <asm/unistd.h>
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/bpf.h>
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#include <linux/btf.h>
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#include <linux/filter.h>
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#include <linux/list.h>
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#include <linux/limits.h>
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#include <linux/perf_event.h>
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#include <linux/ring_buffer.h>
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#include <linux/version.h>
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#include <sys/epoll.h>
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#include <sys/ioctl.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <sys/vfs.h>
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#include <sys/utsname.h>
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#include <sys/resource.h>
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#include <libelf.h>
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#include <gelf.h>
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#include <zlib.h>
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#include "libbpf.h"
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#include "bpf.h"
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#include "btf.h"
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#include "str_error.h"
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#include "libbpf_internal.h"
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#include "hashmap.h"
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#include "bpf_gen_internal.h"
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#ifndef BPF_FS_MAGIC
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#define BPF_FS_MAGIC 0xcafe4a11
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#endif
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#define BPF_INSN_SZ (sizeof(struct bpf_insn))
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/* vsprintf() in __base_pr() uses nonliteral format string. It may break
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* compilation if user enables corresponding warning. Disable it explicitly.
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*/
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#pragma GCC diagnostic ignored "-Wformat-nonliteral"
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#define __printf(a, b) __attribute__((format(printf, a, b)))
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static struct bpf_map *bpf_object__add_map(struct bpf_object *obj);
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static bool prog_is_subprog(const struct bpf_object *obj, const struct bpf_program *prog);
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static int __base_pr(enum libbpf_print_level level, const char *format,
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va_list args)
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{
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if (level == LIBBPF_DEBUG)
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return 0;
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return vfprintf(stderr, format, args);
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}
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static libbpf_print_fn_t __libbpf_pr = __base_pr;
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libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn)
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{
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libbpf_print_fn_t old_print_fn = __libbpf_pr;
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__libbpf_pr = fn;
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return old_print_fn;
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}
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__printf(2, 3)
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void libbpf_print(enum libbpf_print_level level, const char *format, ...)
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{
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va_list args;
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if (!__libbpf_pr)
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return;
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va_start(args, format);
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__libbpf_pr(level, format, args);
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va_end(args);
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}
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static void pr_perm_msg(int err)
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{
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struct rlimit limit;
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char buf[100];
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if (err != -EPERM || geteuid() != 0)
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return;
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err = getrlimit(RLIMIT_MEMLOCK, &limit);
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if (err)
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return;
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if (limit.rlim_cur == RLIM_INFINITY)
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return;
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if (limit.rlim_cur < 1024)
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snprintf(buf, sizeof(buf), "%zu bytes", (size_t)limit.rlim_cur);
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else if (limit.rlim_cur < 1024*1024)
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snprintf(buf, sizeof(buf), "%.1f KiB", (double)limit.rlim_cur / 1024);
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else
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snprintf(buf, sizeof(buf), "%.1f MiB", (double)limit.rlim_cur / (1024*1024));
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pr_warn("permission error while running as root; try raising 'ulimit -l'? current value: %s\n",
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buf);
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}
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#define STRERR_BUFSIZE 128
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/* Copied from tools/perf/util/util.h */
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#ifndef zfree
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# define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
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#endif
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#ifndef zclose
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# define zclose(fd) ({ \
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int ___err = 0; \
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if ((fd) >= 0) \
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___err = close((fd)); \
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fd = -1; \
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___err; })
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#endif
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static inline __u64 ptr_to_u64(const void *ptr)
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{
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return (__u64) (unsigned long) ptr;
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}
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/* this goes away in libbpf 1.0 */
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enum libbpf_strict_mode libbpf_mode = LIBBPF_STRICT_NONE;
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int libbpf_set_strict_mode(enum libbpf_strict_mode mode)
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{
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libbpf_mode = mode;
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return 0;
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}
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__u32 libbpf_major_version(void)
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{
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return LIBBPF_MAJOR_VERSION;
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}
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__u32 libbpf_minor_version(void)
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{
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return LIBBPF_MINOR_VERSION;
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}
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const char *libbpf_version_string(void)
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{
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#define __S(X) #X
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#define _S(X) __S(X)
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return "v" _S(LIBBPF_MAJOR_VERSION) "." _S(LIBBPF_MINOR_VERSION);
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#undef _S
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#undef __S
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}
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enum reloc_type {
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RELO_LD64,
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RELO_CALL,
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RELO_DATA,
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RELO_EXTERN_VAR,
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RELO_EXTERN_FUNC,
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RELO_SUBPROG_ADDR,
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RELO_CORE,
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};
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struct reloc_desc {
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enum reloc_type type;
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int insn_idx;
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union {
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const struct bpf_core_relo *core_relo; /* used when type == RELO_CORE */
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struct {
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int map_idx;
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int sym_off;
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};
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};
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};
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/* stored as sec_def->cookie for all libbpf-supported SEC()s */
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enum sec_def_flags {
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SEC_NONE = 0,
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/* expected_attach_type is optional, if kernel doesn't support that */
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SEC_EXP_ATTACH_OPT = 1,
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/* legacy, only used by libbpf_get_type_names() and
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* libbpf_attach_type_by_name(), not used by libbpf itself at all.
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* This used to be associated with cgroup (and few other) BPF programs
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* that were attachable through BPF_PROG_ATTACH command. Pretty
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* meaningless nowadays, though.
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*/
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SEC_ATTACHABLE = 2,
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SEC_ATTACHABLE_OPT = SEC_ATTACHABLE | SEC_EXP_ATTACH_OPT,
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/* attachment target is specified through BTF ID in either kernel or
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* other BPF program's BTF object */
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SEC_ATTACH_BTF = 4,
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/* BPF program type allows sleeping/blocking in kernel */
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SEC_SLEEPABLE = 8,
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/* allow non-strict prefix matching */
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SEC_SLOPPY_PFX = 16,
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/* BPF program support non-linear XDP buffer */
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SEC_XDP_FRAGS = 32,
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/* deprecated sec definitions not supposed to be used */
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SEC_DEPRECATED = 64,
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};
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struct bpf_sec_def {
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char *sec;
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enum bpf_prog_type prog_type;
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enum bpf_attach_type expected_attach_type;
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long cookie;
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int handler_id;
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libbpf_prog_setup_fn_t prog_setup_fn;
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libbpf_prog_prepare_load_fn_t prog_prepare_load_fn;
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libbpf_prog_attach_fn_t prog_attach_fn;
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};
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/*
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* bpf_prog should be a better name but it has been used in
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* linux/filter.h.
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*/
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struct bpf_program {
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const struct bpf_sec_def *sec_def;
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char *sec_name;
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size_t sec_idx;
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/* this program's instruction offset (in number of instructions)
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* within its containing ELF section
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*/
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size_t sec_insn_off;
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/* number of original instructions in ELF section belonging to this
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* program, not taking into account subprogram instructions possible
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* appended later during relocation
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*/
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size_t sec_insn_cnt;
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/* Offset (in number of instructions) of the start of instruction
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* belonging to this BPF program within its containing main BPF
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* program. For the entry-point (main) BPF program, this is always
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* zero. For a sub-program, this gets reset before each of main BPF
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* programs are processed and relocated and is used to determined
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* whether sub-program was already appended to the main program, and
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* if yes, at which instruction offset.
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*/
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size_t sub_insn_off;
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char *name;
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/* name with / replaced by _; makes recursive pinning
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* in bpf_object__pin_programs easier
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*/
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char *pin_name;
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/* instructions that belong to BPF program; insns[0] is located at
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* sec_insn_off instruction within its ELF section in ELF file, so
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* when mapping ELF file instruction index to the local instruction,
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* one needs to subtract sec_insn_off; and vice versa.
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*/
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struct bpf_insn *insns;
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/* actual number of instruction in this BPF program's image; for
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* entry-point BPF programs this includes the size of main program
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* itself plus all the used sub-programs, appended at the end
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*/
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size_t insns_cnt;
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struct reloc_desc *reloc_desc;
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int nr_reloc;
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/* BPF verifier log settings */
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char *log_buf;
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size_t log_size;
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__u32 log_level;
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struct {
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int nr;
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int *fds;
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} instances;
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bpf_program_prep_t preprocessor;
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struct bpf_object *obj;
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void *priv;
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bpf_program_clear_priv_t clear_priv;
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bool autoload;
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bool mark_btf_static;
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enum bpf_prog_type type;
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enum bpf_attach_type expected_attach_type;
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int prog_ifindex;
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__u32 attach_btf_obj_fd;
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__u32 attach_btf_id;
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__u32 attach_prog_fd;
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void *func_info;
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__u32 func_info_rec_size;
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__u32 func_info_cnt;
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void *line_info;
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__u32 line_info_rec_size;
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__u32 line_info_cnt;
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__u32 prog_flags;
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};
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struct bpf_struct_ops {
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const char *tname;
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const struct btf_type *type;
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struct bpf_program **progs;
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__u32 *kern_func_off;
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/* e.g. struct tcp_congestion_ops in bpf_prog's btf format */
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void *data;
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/* e.g. struct bpf_struct_ops_tcp_congestion_ops in
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* btf_vmlinux's format.
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* struct bpf_struct_ops_tcp_congestion_ops {
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* [... some other kernel fields ...]
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* struct tcp_congestion_ops data;
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* }
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* kern_vdata-size == sizeof(struct bpf_struct_ops_tcp_congestion_ops)
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* bpf_map__init_kern_struct_ops() will populate the "kern_vdata"
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* from "data".
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*/
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void *kern_vdata;
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__u32 type_id;
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};
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#define DATA_SEC ".data"
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#define BSS_SEC ".bss"
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#define RODATA_SEC ".rodata"
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#define KCONFIG_SEC ".kconfig"
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#define KSYMS_SEC ".ksyms"
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#define STRUCT_OPS_SEC ".struct_ops"
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enum libbpf_map_type {
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LIBBPF_MAP_UNSPEC,
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LIBBPF_MAP_DATA,
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LIBBPF_MAP_BSS,
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LIBBPF_MAP_RODATA,
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LIBBPF_MAP_KCONFIG,
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};
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struct bpf_map {
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struct bpf_object *obj;
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char *name;
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/* real_name is defined for special internal maps (.rodata*,
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* .data*, .bss, .kconfig) and preserves their original ELF section
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* name. This is important to be be able to find corresponding BTF
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* DATASEC information.
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*/
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char *real_name;
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int fd;
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int sec_idx;
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size_t sec_offset;
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int map_ifindex;
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int inner_map_fd;
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struct bpf_map_def def;
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__u32 numa_node;
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__u32 btf_var_idx;
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__u32 btf_key_type_id;
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__u32 btf_value_type_id;
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__u32 btf_vmlinux_value_type_id;
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void *priv;
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bpf_map_clear_priv_t clear_priv;
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enum libbpf_map_type libbpf_type;
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void *mmaped;
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struct bpf_struct_ops *st_ops;
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struct bpf_map *inner_map;
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void **init_slots;
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int init_slots_sz;
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char *pin_path;
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bool pinned;
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bool reused;
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bool autocreate;
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__u64 map_extra;
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};
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enum extern_type {
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EXT_UNKNOWN,
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EXT_KCFG,
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EXT_KSYM,
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};
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enum kcfg_type {
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KCFG_UNKNOWN,
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KCFG_CHAR,
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KCFG_BOOL,
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KCFG_INT,
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KCFG_TRISTATE,
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KCFG_CHAR_ARR,
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};
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struct extern_desc {
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enum extern_type type;
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int sym_idx;
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int btf_id;
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int sec_btf_id;
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const char *name;
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bool is_set;
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bool is_weak;
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union {
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struct {
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enum kcfg_type type;
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int sz;
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int align;
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int data_off;
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bool is_signed;
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} kcfg;
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struct {
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unsigned long long addr;
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/* target btf_id of the corresponding kernel var. */
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int kernel_btf_obj_fd;
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int kernel_btf_id;
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/* local btf_id of the ksym extern's type. */
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__u32 type_id;
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/* BTF fd index to be patched in for insn->off, this is
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* 0 for vmlinux BTF, index in obj->fd_array for module
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* BTF
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*/
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__s16 btf_fd_idx;
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} ksym;
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};
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};
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static LIST_HEAD(bpf_objects_list);
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struct module_btf {
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struct btf *btf;
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char *name;
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__u32 id;
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int fd;
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int fd_array_idx;
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};
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enum sec_type {
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SEC_UNUSED = 0,
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SEC_RELO,
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SEC_BSS,
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SEC_DATA,
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SEC_RODATA,
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};
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|
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struct elf_sec_desc {
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enum sec_type sec_type;
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Elf64_Shdr *shdr;
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Elf_Data *data;
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};
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struct elf_state {
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int fd;
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const void *obj_buf;
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size_t obj_buf_sz;
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Elf *elf;
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Elf64_Ehdr *ehdr;
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Elf_Data *symbols;
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Elf_Data *st_ops_data;
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size_t shstrndx; /* section index for section name strings */
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size_t strtabidx;
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struct elf_sec_desc *secs;
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int sec_cnt;
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int maps_shndx;
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int btf_maps_shndx;
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__u32 btf_maps_sec_btf_id;
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int text_shndx;
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int symbols_shndx;
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int st_ops_shndx;
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};
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|
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struct usdt_manager;
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|
|
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struct bpf_object {
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char name[BPF_OBJ_NAME_LEN];
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char license[64];
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__u32 kern_version;
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|
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struct bpf_program *programs;
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size_t nr_programs;
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struct bpf_map *maps;
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size_t nr_maps;
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size_t maps_cap;
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char *kconfig;
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struct extern_desc *externs;
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int nr_extern;
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int kconfig_map_idx;
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|
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bool loaded;
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bool has_subcalls;
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bool has_rodata;
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struct bpf_gen *gen_loader;
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/* Information when doing ELF related work. Only valid if efile.elf is not NULL */
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struct elf_state efile;
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/*
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* All loaded bpf_object are linked in a list, which is
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* hidden to caller. bpf_objects__<func> handlers deal with
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* all objects.
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*/
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struct list_head list;
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struct btf *btf;
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struct btf_ext *btf_ext;
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|
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/* Parse and load BTF vmlinux if any of the programs in the object need
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* it at load time.
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*/
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struct btf *btf_vmlinux;
|
|
/* Path to the custom BTF to be used for BPF CO-RE relocations as an
|
|
* override for vmlinux BTF.
|
|
*/
|
|
char *btf_custom_path;
|
|
/* vmlinux BTF override for CO-RE relocations */
|
|
struct btf *btf_vmlinux_override;
|
|
/* Lazily initialized kernel module BTFs */
|
|
struct module_btf *btf_modules;
|
|
bool btf_modules_loaded;
|
|
size_t btf_module_cnt;
|
|
size_t btf_module_cap;
|
|
|
|
/* optional log settings passed to BPF_BTF_LOAD and BPF_PROG_LOAD commands */
|
|
char *log_buf;
|
|
size_t log_size;
|
|
__u32 log_level;
|
|
|
|
void *priv;
|
|
bpf_object_clear_priv_t clear_priv;
|
|
|
|
int *fd_array;
|
|
size_t fd_array_cap;
|
|
size_t fd_array_cnt;
|
|
|
|
struct usdt_manager *usdt_man;
|
|
|
|
char path[];
|
|
};
|
|
|
|
static const char *elf_sym_str(const struct bpf_object *obj, size_t off);
|
|
static const char *elf_sec_str(const struct bpf_object *obj, size_t off);
|
|
static Elf_Scn *elf_sec_by_idx(const struct bpf_object *obj, size_t idx);
|
|
static Elf_Scn *elf_sec_by_name(const struct bpf_object *obj, const char *name);
|
|
static Elf64_Shdr *elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn);
|
|
static const char *elf_sec_name(const struct bpf_object *obj, Elf_Scn *scn);
|
|
static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn);
|
|
static Elf64_Sym *elf_sym_by_idx(const struct bpf_object *obj, size_t idx);
|
|
static Elf64_Rel *elf_rel_by_idx(Elf_Data *data, size_t idx);
|
|
|
|
void bpf_program__unload(struct bpf_program *prog)
|
|
{
|
|
int i;
|
|
|
|
if (!prog)
|
|
return;
|
|
|
|
/*
|
|
* If the object is opened but the program was never loaded,
|
|
* it is possible that prog->instances.nr == -1.
|
|
*/
|
|
if (prog->instances.nr > 0) {
|
|
for (i = 0; i < prog->instances.nr; i++)
|
|
zclose(prog->instances.fds[i]);
|
|
} else if (prog->instances.nr != -1) {
|
|
pr_warn("Internal error: instances.nr is %d\n",
|
|
prog->instances.nr);
|
|
}
|
|
|
|
prog->instances.nr = -1;
|
|
zfree(&prog->instances.fds);
|
|
|
|
zfree(&prog->func_info);
|
|
zfree(&prog->line_info);
|
|
}
|
|
|
|
static void bpf_program__exit(struct bpf_program *prog)
|
|
{
|
|
if (!prog)
|
|
return;
|
|
|
|
if (prog->clear_priv)
|
|
prog->clear_priv(prog, prog->priv);
|
|
|
|
prog->priv = NULL;
|
|
prog->clear_priv = NULL;
|
|
|
|
bpf_program__unload(prog);
|
|
zfree(&prog->name);
|
|
zfree(&prog->sec_name);
|
|
zfree(&prog->pin_name);
|
|
zfree(&prog->insns);
|
|
zfree(&prog->reloc_desc);
|
|
|
|
prog->nr_reloc = 0;
|
|
prog->insns_cnt = 0;
|
|
prog->sec_idx = -1;
|
|
}
|
|
|
|
static char *__bpf_program__pin_name(struct bpf_program *prog)
|
|
{
|
|
char *name, *p;
|
|
|
|
if (libbpf_mode & LIBBPF_STRICT_SEC_NAME)
|
|
name = strdup(prog->name);
|
|
else
|
|
name = strdup(prog->sec_name);
|
|
|
|
if (!name)
|
|
return NULL;
|
|
|
|
p = name;
|
|
|
|
while ((p = strchr(p, '/')))
|
|
*p = '_';
|
|
|
|
return name;
|
|
}
|
|
|
|
static bool insn_is_subprog_call(const struct bpf_insn *insn)
|
|
{
|
|
return BPF_CLASS(insn->code) == BPF_JMP &&
|
|
BPF_OP(insn->code) == BPF_CALL &&
|
|
BPF_SRC(insn->code) == BPF_K &&
|
|
insn->src_reg == BPF_PSEUDO_CALL &&
|
|
insn->dst_reg == 0 &&
|
|
insn->off == 0;
|
|
}
|
|
|
|
static bool is_call_insn(const struct bpf_insn *insn)
|
|
{
|
|
return insn->code == (BPF_JMP | BPF_CALL);
|
|
}
|
|
|
|
static bool insn_is_pseudo_func(struct bpf_insn *insn)
|
|
{
|
|
return is_ldimm64_insn(insn) && insn->src_reg == BPF_PSEUDO_FUNC;
|
|
}
|
|
|
|
static int
|
|
bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog,
|
|
const char *name, size_t sec_idx, const char *sec_name,
|
|
size_t sec_off, void *insn_data, size_t insn_data_sz)
|
|
{
|
|
if (insn_data_sz == 0 || insn_data_sz % BPF_INSN_SZ || sec_off % BPF_INSN_SZ) {
|
|
pr_warn("sec '%s': corrupted program '%s', offset %zu, size %zu\n",
|
|
sec_name, name, sec_off, insn_data_sz);
|
|
return -EINVAL;
|
|
}
|
|
|
|
memset(prog, 0, sizeof(*prog));
|
|
prog->obj = obj;
|
|
|
|
prog->sec_idx = sec_idx;
|
|
prog->sec_insn_off = sec_off / BPF_INSN_SZ;
|
|
prog->sec_insn_cnt = insn_data_sz / BPF_INSN_SZ;
|
|
/* insns_cnt can later be increased by appending used subprograms */
|
|
prog->insns_cnt = prog->sec_insn_cnt;
|
|
|
|
prog->type = BPF_PROG_TYPE_UNSPEC;
|
|
|
|
/* libbpf's convention for SEC("?abc...") is that it's just like
|
|
* SEC("abc...") but the corresponding bpf_program starts out with
|
|
* autoload set to false.
|
|
*/
|
|
if (sec_name[0] == '?') {
|
|
prog->autoload = false;
|
|
/* from now on forget there was ? in section name */
|
|
sec_name++;
|
|
} else {
|
|
prog->autoload = true;
|
|
}
|
|
|
|
prog->instances.fds = NULL;
|
|
prog->instances.nr = -1;
|
|
|
|
/* inherit object's log_level */
|
|
prog->log_level = obj->log_level;
|
|
|
|
prog->sec_name = strdup(sec_name);
|
|
if (!prog->sec_name)
|
|
goto errout;
|
|
|
|
prog->name = strdup(name);
|
|
if (!prog->name)
|
|
goto errout;
|
|
|
|
prog->pin_name = __bpf_program__pin_name(prog);
|
|
if (!prog->pin_name)
|
|
goto errout;
|
|
|
|
prog->insns = malloc(insn_data_sz);
|
|
if (!prog->insns)
|
|
goto errout;
|
|
memcpy(prog->insns, insn_data, insn_data_sz);
|
|
|
|
return 0;
|
|
errout:
|
|
pr_warn("sec '%s': failed to allocate memory for prog '%s'\n", sec_name, name);
|
|
bpf_program__exit(prog);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int
|
|
bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data,
|
|
const char *sec_name, int sec_idx)
|
|
{
|
|
Elf_Data *symbols = obj->efile.symbols;
|
|
struct bpf_program *prog, *progs;
|
|
void *data = sec_data->d_buf;
|
|
size_t sec_sz = sec_data->d_size, sec_off, prog_sz, nr_syms;
|
|
int nr_progs, err, i;
|
|
const char *name;
|
|
Elf64_Sym *sym;
|
|
|
|
progs = obj->programs;
|
|
nr_progs = obj->nr_programs;
|
|
nr_syms = symbols->d_size / sizeof(Elf64_Sym);
|
|
sec_off = 0;
|
|
|
|
for (i = 0; i < nr_syms; i++) {
|
|
sym = elf_sym_by_idx(obj, i);
|
|
|
|
if (sym->st_shndx != sec_idx)
|
|
continue;
|
|
if (ELF64_ST_TYPE(sym->st_info) != STT_FUNC)
|
|
continue;
|
|
|
|
prog_sz = sym->st_size;
|
|
sec_off = sym->st_value;
|
|
|
|
name = elf_sym_str(obj, sym->st_name);
|
|
if (!name) {
|
|
pr_warn("sec '%s': failed to get symbol name for offset %zu\n",
|
|
sec_name, sec_off);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
if (sec_off + prog_sz > sec_sz) {
|
|
pr_warn("sec '%s': program at offset %zu crosses section boundary\n",
|
|
sec_name, sec_off);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
if (sec_idx != obj->efile.text_shndx && ELF64_ST_BIND(sym->st_info) == STB_LOCAL) {
|
|
pr_warn("sec '%s': program '%s' is static and not supported\n", sec_name, name);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
pr_debug("sec '%s': found program '%s' at insn offset %zu (%zu bytes), code size %zu insns (%zu bytes)\n",
|
|
sec_name, name, sec_off / BPF_INSN_SZ, sec_off, prog_sz / BPF_INSN_SZ, prog_sz);
|
|
|
|
progs = libbpf_reallocarray(progs, nr_progs + 1, sizeof(*progs));
|
|
if (!progs) {
|
|
/*
|
|
* In this case the original obj->programs
|
|
* is still valid, so don't need special treat for
|
|
* bpf_close_object().
|
|
*/
|
|
pr_warn("sec '%s': failed to alloc memory for new program '%s'\n",
|
|
sec_name, name);
|
|
return -ENOMEM;
|
|
}
|
|
obj->programs = progs;
|
|
|
|
prog = &progs[nr_progs];
|
|
|
|
err = bpf_object__init_prog(obj, prog, name, sec_idx, sec_name,
|
|
sec_off, data + sec_off, prog_sz);
|
|
if (err)
|
|
return err;
|
|
|
|
/* if function is a global/weak symbol, but has restricted
|
|
* (STV_HIDDEN or STV_INTERNAL) visibility, mark its BTF FUNC
|
|
* as static to enable more permissive BPF verification mode
|
|
* with more outside context available to BPF verifier
|
|
*/
|
|
if (ELF64_ST_BIND(sym->st_info) != STB_LOCAL
|
|
&& (ELF64_ST_VISIBILITY(sym->st_other) == STV_HIDDEN
|
|
|| ELF64_ST_VISIBILITY(sym->st_other) == STV_INTERNAL))
|
|
prog->mark_btf_static = true;
|
|
|
|
nr_progs++;
|
|
obj->nr_programs = nr_progs;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
__u32 get_kernel_version(void)
|
|
{
|
|
/* On Ubuntu LINUX_VERSION_CODE doesn't correspond to info.release,
|
|
* but Ubuntu provides /proc/version_signature file, as described at
|
|
* https://ubuntu.com/kernel, with an example contents below, which we
|
|
* can use to get a proper LINUX_VERSION_CODE.
|
|
*
|
|
* Ubuntu 5.4.0-12.15-generic 5.4.8
|
|
*
|
|
* In the above, 5.4.8 is what kernel is actually expecting, while
|
|
* uname() call will return 5.4.0 in info.release.
|
|
*/
|
|
const char *ubuntu_kver_file = "/proc/version_signature";
|
|
__u32 major, minor, patch;
|
|
struct utsname info;
|
|
|
|
if (access(ubuntu_kver_file, R_OK) == 0) {
|
|
FILE *f;
|
|
|
|
f = fopen(ubuntu_kver_file, "r");
|
|
if (f) {
|
|
if (fscanf(f, "%*s %*s %d.%d.%d\n", &major, &minor, &patch) == 3) {
|
|
fclose(f);
|
|
return KERNEL_VERSION(major, minor, patch);
|
|
}
|
|
fclose(f);
|
|
}
|
|
/* something went wrong, fall back to uname() approach */
|
|
}
|
|
|
|
uname(&info);
|
|
if (sscanf(info.release, "%u.%u.%u", &major, &minor, &patch) != 3)
|
|
return 0;
|
|
return KERNEL_VERSION(major, minor, patch);
|
|
}
|
|
|
|
static const struct btf_member *
|
|
find_member_by_offset(const struct btf_type *t, __u32 bit_offset)
|
|
{
|
|
struct btf_member *m;
|
|
int i;
|
|
|
|
for (i = 0, m = btf_members(t); i < btf_vlen(t); i++, m++) {
|
|
if (btf_member_bit_offset(t, i) == bit_offset)
|
|
return m;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static const struct btf_member *
|
|
find_member_by_name(const struct btf *btf, const struct btf_type *t,
|
|
const char *name)
|
|
{
|
|
struct btf_member *m;
|
|
int i;
|
|
|
|
for (i = 0, m = btf_members(t); i < btf_vlen(t); i++, m++) {
|
|
if (!strcmp(btf__name_by_offset(btf, m->name_off), name))
|
|
return m;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
#define STRUCT_OPS_VALUE_PREFIX "bpf_struct_ops_"
|
|
static int find_btf_by_prefix_kind(const struct btf *btf, const char *prefix,
|
|
const char *name, __u32 kind);
|
|
|
|
static int
|
|
find_struct_ops_kern_types(const struct btf *btf, const char *tname,
|
|
const struct btf_type **type, __u32 *type_id,
|
|
const struct btf_type **vtype, __u32 *vtype_id,
|
|
const struct btf_member **data_member)
|
|
{
|
|
const struct btf_type *kern_type, *kern_vtype;
|
|
const struct btf_member *kern_data_member;
|
|
__s32 kern_vtype_id, kern_type_id;
|
|
__u32 i;
|
|
|
|
kern_type_id = btf__find_by_name_kind(btf, tname, BTF_KIND_STRUCT);
|
|
if (kern_type_id < 0) {
|
|
pr_warn("struct_ops init_kern: struct %s is not found in kernel BTF\n",
|
|
tname);
|
|
return kern_type_id;
|
|
}
|
|
kern_type = btf__type_by_id(btf, kern_type_id);
|
|
|
|
/* Find the corresponding "map_value" type that will be used
|
|
* in map_update(BPF_MAP_TYPE_STRUCT_OPS). For example,
|
|
* find "struct bpf_struct_ops_tcp_congestion_ops" from the
|
|
* btf_vmlinux.
|
|
*/
|
|
kern_vtype_id = find_btf_by_prefix_kind(btf, STRUCT_OPS_VALUE_PREFIX,
|
|
tname, BTF_KIND_STRUCT);
|
|
if (kern_vtype_id < 0) {
|
|
pr_warn("struct_ops init_kern: struct %s%s is not found in kernel BTF\n",
|
|
STRUCT_OPS_VALUE_PREFIX, tname);
|
|
return kern_vtype_id;
|
|
}
|
|
kern_vtype = btf__type_by_id(btf, kern_vtype_id);
|
|
|
|
/* Find "struct tcp_congestion_ops" from
|
|
* struct bpf_struct_ops_tcp_congestion_ops {
|
|
* [ ... ]
|
|
* struct tcp_congestion_ops data;
|
|
* }
|
|
*/
|
|
kern_data_member = btf_members(kern_vtype);
|
|
for (i = 0; i < btf_vlen(kern_vtype); i++, kern_data_member++) {
|
|
if (kern_data_member->type == kern_type_id)
|
|
break;
|
|
}
|
|
if (i == btf_vlen(kern_vtype)) {
|
|
pr_warn("struct_ops init_kern: struct %s data is not found in struct %s%s\n",
|
|
tname, STRUCT_OPS_VALUE_PREFIX, tname);
|
|
return -EINVAL;
|
|
}
|
|
|
|
*type = kern_type;
|
|
*type_id = kern_type_id;
|
|
*vtype = kern_vtype;
|
|
*vtype_id = kern_vtype_id;
|
|
*data_member = kern_data_member;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool bpf_map__is_struct_ops(const struct bpf_map *map)
|
|
{
|
|
return map->def.type == BPF_MAP_TYPE_STRUCT_OPS;
|
|
}
|
|
|
|
/* Init the map's fields that depend on kern_btf */
|
|
static int bpf_map__init_kern_struct_ops(struct bpf_map *map,
|
|
const struct btf *btf,
|
|
const struct btf *kern_btf)
|
|
{
|
|
const struct btf_member *member, *kern_member, *kern_data_member;
|
|
const struct btf_type *type, *kern_type, *kern_vtype;
|
|
__u32 i, kern_type_id, kern_vtype_id, kern_data_off;
|
|
struct bpf_struct_ops *st_ops;
|
|
void *data, *kern_data;
|
|
const char *tname;
|
|
int err;
|
|
|
|
st_ops = map->st_ops;
|
|
type = st_ops->type;
|
|
tname = st_ops->tname;
|
|
err = find_struct_ops_kern_types(kern_btf, tname,
|
|
&kern_type, &kern_type_id,
|
|
&kern_vtype, &kern_vtype_id,
|
|
&kern_data_member);
|
|
if (err)
|
|
return err;
|
|
|
|
pr_debug("struct_ops init_kern %s: type_id:%u kern_type_id:%u kern_vtype_id:%u\n",
|
|
map->name, st_ops->type_id, kern_type_id, kern_vtype_id);
|
|
|
|
map->def.value_size = kern_vtype->size;
|
|
map->btf_vmlinux_value_type_id = kern_vtype_id;
|
|
|
|
st_ops->kern_vdata = calloc(1, kern_vtype->size);
|
|
if (!st_ops->kern_vdata)
|
|
return -ENOMEM;
|
|
|
|
data = st_ops->data;
|
|
kern_data_off = kern_data_member->offset / 8;
|
|
kern_data = st_ops->kern_vdata + kern_data_off;
|
|
|
|
member = btf_members(type);
|
|
for (i = 0; i < btf_vlen(type); i++, member++) {
|
|
const struct btf_type *mtype, *kern_mtype;
|
|
__u32 mtype_id, kern_mtype_id;
|
|
void *mdata, *kern_mdata;
|
|
__s64 msize, kern_msize;
|
|
__u32 moff, kern_moff;
|
|
__u32 kern_member_idx;
|
|
const char *mname;
|
|
|
|
mname = btf__name_by_offset(btf, member->name_off);
|
|
kern_member = find_member_by_name(kern_btf, kern_type, mname);
|
|
if (!kern_member) {
|
|
pr_warn("struct_ops init_kern %s: Cannot find member %s in kernel BTF\n",
|
|
map->name, mname);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
kern_member_idx = kern_member - btf_members(kern_type);
|
|
if (btf_member_bitfield_size(type, i) ||
|
|
btf_member_bitfield_size(kern_type, kern_member_idx)) {
|
|
pr_warn("struct_ops init_kern %s: bitfield %s is not supported\n",
|
|
map->name, mname);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
moff = member->offset / 8;
|
|
kern_moff = kern_member->offset / 8;
|
|
|
|
mdata = data + moff;
|
|
kern_mdata = kern_data + kern_moff;
|
|
|
|
mtype = skip_mods_and_typedefs(btf, member->type, &mtype_id);
|
|
kern_mtype = skip_mods_and_typedefs(kern_btf, kern_member->type,
|
|
&kern_mtype_id);
|
|
if (BTF_INFO_KIND(mtype->info) !=
|
|
BTF_INFO_KIND(kern_mtype->info)) {
|
|
pr_warn("struct_ops init_kern %s: Unmatched member type %s %u != %u(kernel)\n",
|
|
map->name, mname, BTF_INFO_KIND(mtype->info),
|
|
BTF_INFO_KIND(kern_mtype->info));
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
if (btf_is_ptr(mtype)) {
|
|
struct bpf_program *prog;
|
|
|
|
prog = st_ops->progs[i];
|
|
if (!prog)
|
|
continue;
|
|
|
|
kern_mtype = skip_mods_and_typedefs(kern_btf,
|
|
kern_mtype->type,
|
|
&kern_mtype_id);
|
|
|
|
/* mtype->type must be a func_proto which was
|
|
* guaranteed in bpf_object__collect_st_ops_relos(),
|
|
* so only check kern_mtype for func_proto here.
|
|
*/
|
|
if (!btf_is_func_proto(kern_mtype)) {
|
|
pr_warn("struct_ops init_kern %s: kernel member %s is not a func ptr\n",
|
|
map->name, mname);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
prog->attach_btf_id = kern_type_id;
|
|
prog->expected_attach_type = kern_member_idx;
|
|
|
|
st_ops->kern_func_off[i] = kern_data_off + kern_moff;
|
|
|
|
pr_debug("struct_ops init_kern %s: func ptr %s is set to prog %s from data(+%u) to kern_data(+%u)\n",
|
|
map->name, mname, prog->name, moff,
|
|
kern_moff);
|
|
|
|
continue;
|
|
}
|
|
|
|
msize = btf__resolve_size(btf, mtype_id);
|
|
kern_msize = btf__resolve_size(kern_btf, kern_mtype_id);
|
|
if (msize < 0 || kern_msize < 0 || msize != kern_msize) {
|
|
pr_warn("struct_ops init_kern %s: Error in size of member %s: %zd != %zd(kernel)\n",
|
|
map->name, mname, (ssize_t)msize,
|
|
(ssize_t)kern_msize);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
pr_debug("struct_ops init_kern %s: copy %s %u bytes from data(+%u) to kern_data(+%u)\n",
|
|
map->name, mname, (unsigned int)msize,
|
|
moff, kern_moff);
|
|
memcpy(kern_mdata, mdata, msize);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__init_kern_struct_ops_maps(struct bpf_object *obj)
|
|
{
|
|
struct bpf_map *map;
|
|
size_t i;
|
|
int err;
|
|
|
|
for (i = 0; i < obj->nr_maps; i++) {
|
|
map = &obj->maps[i];
|
|
|
|
if (!bpf_map__is_struct_ops(map))
|
|
continue;
|
|
|
|
err = bpf_map__init_kern_struct_ops(map, obj->btf,
|
|
obj->btf_vmlinux);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__init_struct_ops_maps(struct bpf_object *obj)
|
|
{
|
|
const struct btf_type *type, *datasec;
|
|
const struct btf_var_secinfo *vsi;
|
|
struct bpf_struct_ops *st_ops;
|
|
const char *tname, *var_name;
|
|
__s32 type_id, datasec_id;
|
|
const struct btf *btf;
|
|
struct bpf_map *map;
|
|
__u32 i;
|
|
|
|
if (obj->efile.st_ops_shndx == -1)
|
|
return 0;
|
|
|
|
btf = obj->btf;
|
|
datasec_id = btf__find_by_name_kind(btf, STRUCT_OPS_SEC,
|
|
BTF_KIND_DATASEC);
|
|
if (datasec_id < 0) {
|
|
pr_warn("struct_ops init: DATASEC %s not found\n",
|
|
STRUCT_OPS_SEC);
|
|
return -EINVAL;
|
|
}
|
|
|
|
datasec = btf__type_by_id(btf, datasec_id);
|
|
vsi = btf_var_secinfos(datasec);
|
|
for (i = 0; i < btf_vlen(datasec); i++, vsi++) {
|
|
type = btf__type_by_id(obj->btf, vsi->type);
|
|
var_name = btf__name_by_offset(obj->btf, type->name_off);
|
|
|
|
type_id = btf__resolve_type(obj->btf, vsi->type);
|
|
if (type_id < 0) {
|
|
pr_warn("struct_ops init: Cannot resolve var type_id %u in DATASEC %s\n",
|
|
vsi->type, STRUCT_OPS_SEC);
|
|
return -EINVAL;
|
|
}
|
|
|
|
type = btf__type_by_id(obj->btf, type_id);
|
|
tname = btf__name_by_offset(obj->btf, type->name_off);
|
|
if (!tname[0]) {
|
|
pr_warn("struct_ops init: anonymous type is not supported\n");
|
|
return -ENOTSUP;
|
|
}
|
|
if (!btf_is_struct(type)) {
|
|
pr_warn("struct_ops init: %s is not a struct\n", tname);
|
|
return -EINVAL;
|
|
}
|
|
|
|
map = bpf_object__add_map(obj);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
|
|
map->sec_idx = obj->efile.st_ops_shndx;
|
|
map->sec_offset = vsi->offset;
|
|
map->name = strdup(var_name);
|
|
if (!map->name)
|
|
return -ENOMEM;
|
|
|
|
map->def.type = BPF_MAP_TYPE_STRUCT_OPS;
|
|
map->def.key_size = sizeof(int);
|
|
map->def.value_size = type->size;
|
|
map->def.max_entries = 1;
|
|
|
|
map->st_ops = calloc(1, sizeof(*map->st_ops));
|
|
if (!map->st_ops)
|
|
return -ENOMEM;
|
|
st_ops = map->st_ops;
|
|
st_ops->data = malloc(type->size);
|
|
st_ops->progs = calloc(btf_vlen(type), sizeof(*st_ops->progs));
|
|
st_ops->kern_func_off = malloc(btf_vlen(type) *
|
|
sizeof(*st_ops->kern_func_off));
|
|
if (!st_ops->data || !st_ops->progs || !st_ops->kern_func_off)
|
|
return -ENOMEM;
|
|
|
|
if (vsi->offset + type->size > obj->efile.st_ops_data->d_size) {
|
|
pr_warn("struct_ops init: var %s is beyond the end of DATASEC %s\n",
|
|
var_name, STRUCT_OPS_SEC);
|
|
return -EINVAL;
|
|
}
|
|
|
|
memcpy(st_ops->data,
|
|
obj->efile.st_ops_data->d_buf + vsi->offset,
|
|
type->size);
|
|
st_ops->tname = tname;
|
|
st_ops->type = type;
|
|
st_ops->type_id = type_id;
|
|
|
|
pr_debug("struct_ops init: struct %s(type_id=%u) %s found at offset %u\n",
|
|
tname, type_id, var_name, vsi->offset);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct bpf_object *bpf_object__new(const char *path,
|
|
const void *obj_buf,
|
|
size_t obj_buf_sz,
|
|
const char *obj_name)
|
|
{
|
|
bool strict = (libbpf_mode & LIBBPF_STRICT_NO_OBJECT_LIST);
|
|
struct bpf_object *obj;
|
|
char *end;
|
|
|
|
obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
|
|
if (!obj) {
|
|
pr_warn("alloc memory failed for %s\n", path);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
strcpy(obj->path, path);
|
|
if (obj_name) {
|
|
libbpf_strlcpy(obj->name, obj_name, sizeof(obj->name));
|
|
} else {
|
|
/* Using basename() GNU version which doesn't modify arg. */
|
|
libbpf_strlcpy(obj->name, basename((void *)path), sizeof(obj->name));
|
|
end = strchr(obj->name, '.');
|
|
if (end)
|
|
*end = 0;
|
|
}
|
|
|
|
obj->efile.fd = -1;
|
|
/*
|
|
* Caller of this function should also call
|
|
* bpf_object__elf_finish() after data collection to return
|
|
* obj_buf to user. If not, we should duplicate the buffer to
|
|
* avoid user freeing them before elf finish.
|
|
*/
|
|
obj->efile.obj_buf = obj_buf;
|
|
obj->efile.obj_buf_sz = obj_buf_sz;
|
|
obj->efile.maps_shndx = -1;
|
|
obj->efile.btf_maps_shndx = -1;
|
|
obj->efile.st_ops_shndx = -1;
|
|
obj->kconfig_map_idx = -1;
|
|
|
|
obj->kern_version = get_kernel_version();
|
|
obj->loaded = false;
|
|
|
|
INIT_LIST_HEAD(&obj->list);
|
|
if (!strict)
|
|
list_add(&obj->list, &bpf_objects_list);
|
|
return obj;
|
|
}
|
|
|
|
static void bpf_object__elf_finish(struct bpf_object *obj)
|
|
{
|
|
if (!obj->efile.elf)
|
|
return;
|
|
|
|
elf_end(obj->efile.elf);
|
|
obj->efile.elf = NULL;
|
|
obj->efile.symbols = NULL;
|
|
obj->efile.st_ops_data = NULL;
|
|
|
|
zfree(&obj->efile.secs);
|
|
obj->efile.sec_cnt = 0;
|
|
zclose(obj->efile.fd);
|
|
obj->efile.obj_buf = NULL;
|
|
obj->efile.obj_buf_sz = 0;
|
|
}
|
|
|
|
static int bpf_object__elf_init(struct bpf_object *obj)
|
|
{
|
|
Elf64_Ehdr *ehdr;
|
|
int err = 0;
|
|
Elf *elf;
|
|
|
|
if (obj->efile.elf) {
|
|
pr_warn("elf: init internal error\n");
|
|
return -LIBBPF_ERRNO__LIBELF;
|
|
}
|
|
|
|
if (obj->efile.obj_buf_sz > 0) {
|
|
/*
|
|
* obj_buf should have been validated by
|
|
* bpf_object__open_buffer().
|
|
*/
|
|
elf = elf_memory((char *)obj->efile.obj_buf, obj->efile.obj_buf_sz);
|
|
} else {
|
|
obj->efile.fd = open(obj->path, O_RDONLY | O_CLOEXEC);
|
|
if (obj->efile.fd < 0) {
|
|
char errmsg[STRERR_BUFSIZE], *cp;
|
|
|
|
err = -errno;
|
|
cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
|
|
pr_warn("elf: failed to open %s: %s\n", obj->path, cp);
|
|
return err;
|
|
}
|
|
|
|
elf = elf_begin(obj->efile.fd, ELF_C_READ_MMAP, NULL);
|
|
}
|
|
|
|
if (!elf) {
|
|
pr_warn("elf: failed to open %s as ELF file: %s\n", obj->path, elf_errmsg(-1));
|
|
err = -LIBBPF_ERRNO__LIBELF;
|
|
goto errout;
|
|
}
|
|
|
|
obj->efile.elf = elf;
|
|
|
|
if (elf_kind(elf) != ELF_K_ELF) {
|
|
err = -LIBBPF_ERRNO__FORMAT;
|
|
pr_warn("elf: '%s' is not a proper ELF object\n", obj->path);
|
|
goto errout;
|
|
}
|
|
|
|
if (gelf_getclass(elf) != ELFCLASS64) {
|
|
err = -LIBBPF_ERRNO__FORMAT;
|
|
pr_warn("elf: '%s' is not a 64-bit ELF object\n", obj->path);
|
|
goto errout;
|
|
}
|
|
|
|
obj->efile.ehdr = ehdr = elf64_getehdr(elf);
|
|
if (!obj->efile.ehdr) {
|
|
pr_warn("elf: failed to get ELF header from %s: %s\n", obj->path, elf_errmsg(-1));
|
|
err = -LIBBPF_ERRNO__FORMAT;
|
|
goto errout;
|
|
}
|
|
|
|
if (elf_getshdrstrndx(elf, &obj->efile.shstrndx)) {
|
|
pr_warn("elf: failed to get section names section index for %s: %s\n",
|
|
obj->path, elf_errmsg(-1));
|
|
err = -LIBBPF_ERRNO__FORMAT;
|
|
goto errout;
|
|
}
|
|
|
|
/* Elf is corrupted/truncated, avoid calling elf_strptr. */
|
|
if (!elf_rawdata(elf_getscn(elf, obj->efile.shstrndx), NULL)) {
|
|
pr_warn("elf: failed to get section names strings from %s: %s\n",
|
|
obj->path, elf_errmsg(-1));
|
|
err = -LIBBPF_ERRNO__FORMAT;
|
|
goto errout;
|
|
}
|
|
|
|
/* Old LLVM set e_machine to EM_NONE */
|
|
if (ehdr->e_type != ET_REL || (ehdr->e_machine && ehdr->e_machine != EM_BPF)) {
|
|
pr_warn("elf: %s is not a valid eBPF object file\n", obj->path);
|
|
err = -LIBBPF_ERRNO__FORMAT;
|
|
goto errout;
|
|
}
|
|
|
|
return 0;
|
|
errout:
|
|
bpf_object__elf_finish(obj);
|
|
return err;
|
|
}
|
|
|
|
static int bpf_object__check_endianness(struct bpf_object *obj)
|
|
{
|
|
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
|
|
if (obj->efile.ehdr->e_ident[EI_DATA] == ELFDATA2LSB)
|
|
return 0;
|
|
#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
|
|
if (obj->efile.ehdr->e_ident[EI_DATA] == ELFDATA2MSB)
|
|
return 0;
|
|
#else
|
|
# error "Unrecognized __BYTE_ORDER__"
|
|
#endif
|
|
pr_warn("elf: endianness mismatch in %s.\n", obj->path);
|
|
return -LIBBPF_ERRNO__ENDIAN;
|
|
}
|
|
|
|
static int
|
|
bpf_object__init_license(struct bpf_object *obj, void *data, size_t size)
|
|
{
|
|
/* libbpf_strlcpy() only copies first N - 1 bytes, so size + 1 won't
|
|
* go over allowed ELF data section buffer
|
|
*/
|
|
libbpf_strlcpy(obj->license, data, min(size + 1, sizeof(obj->license)));
|
|
pr_debug("license of %s is %s\n", obj->path, obj->license);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_object__init_kversion(struct bpf_object *obj, void *data, size_t size)
|
|
{
|
|
__u32 kver;
|
|
|
|
if (size != sizeof(kver)) {
|
|
pr_warn("invalid kver section in %s\n", obj->path);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
memcpy(&kver, data, sizeof(kver));
|
|
obj->kern_version = kver;
|
|
pr_debug("kernel version of %s is %x\n", obj->path, obj->kern_version);
|
|
return 0;
|
|
}
|
|
|
|
static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
|
|
{
|
|
if (type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
|
|
type == BPF_MAP_TYPE_HASH_OF_MAPS)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
static int find_elf_sec_sz(const struct bpf_object *obj, const char *name, __u32 *size)
|
|
{
|
|
Elf_Data *data;
|
|
Elf_Scn *scn;
|
|
|
|
if (!name)
|
|
return -EINVAL;
|
|
|
|
scn = elf_sec_by_name(obj, name);
|
|
data = elf_sec_data(obj, scn);
|
|
if (data) {
|
|
*size = data->d_size;
|
|
return 0; /* found it */
|
|
}
|
|
|
|
return -ENOENT;
|
|
}
|
|
|
|
static int find_elf_var_offset(const struct bpf_object *obj, const char *name, __u32 *off)
|
|
{
|
|
Elf_Data *symbols = obj->efile.symbols;
|
|
const char *sname;
|
|
size_t si;
|
|
|
|
if (!name || !off)
|
|
return -EINVAL;
|
|
|
|
for (si = 0; si < symbols->d_size / sizeof(Elf64_Sym); si++) {
|
|
Elf64_Sym *sym = elf_sym_by_idx(obj, si);
|
|
|
|
if (ELF64_ST_TYPE(sym->st_info) != STT_OBJECT)
|
|
continue;
|
|
|
|
if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL &&
|
|
ELF64_ST_BIND(sym->st_info) != STB_WEAK)
|
|
continue;
|
|
|
|
sname = elf_sym_str(obj, sym->st_name);
|
|
if (!sname) {
|
|
pr_warn("failed to get sym name string for var %s\n", name);
|
|
return -EIO;
|
|
}
|
|
if (strcmp(name, sname) == 0) {
|
|
*off = sym->st_value;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return -ENOENT;
|
|
}
|
|
|
|
static struct bpf_map *bpf_object__add_map(struct bpf_object *obj)
|
|
{
|
|
struct bpf_map *map;
|
|
int err;
|
|
|
|
err = libbpf_ensure_mem((void **)&obj->maps, &obj->maps_cap,
|
|
sizeof(*obj->maps), obj->nr_maps + 1);
|
|
if (err)
|
|
return ERR_PTR(err);
|
|
|
|
map = &obj->maps[obj->nr_maps++];
|
|
map->obj = obj;
|
|
map->fd = -1;
|
|
map->inner_map_fd = -1;
|
|
map->autocreate = true;
|
|
|
|
return map;
|
|
}
|
|
|
|
static size_t bpf_map_mmap_sz(const struct bpf_map *map)
|
|
{
|
|
long page_sz = sysconf(_SC_PAGE_SIZE);
|
|
size_t map_sz;
|
|
|
|
map_sz = (size_t)roundup(map->def.value_size, 8) * map->def.max_entries;
|
|
map_sz = roundup(map_sz, page_sz);
|
|
return map_sz;
|
|
}
|
|
|
|
static char *internal_map_name(struct bpf_object *obj, const char *real_name)
|
|
{
|
|
char map_name[BPF_OBJ_NAME_LEN], *p;
|
|
int pfx_len, sfx_len = max((size_t)7, strlen(real_name));
|
|
|
|
/* This is one of the more confusing parts of libbpf for various
|
|
* reasons, some of which are historical. The original idea for naming
|
|
* internal names was to include as much of BPF object name prefix as
|
|
* possible, so that it can be distinguished from similar internal
|
|
* maps of a different BPF object.
|
|
* As an example, let's say we have bpf_object named 'my_object_name'
|
|
* and internal map corresponding to '.rodata' ELF section. The final
|
|
* map name advertised to user and to the kernel will be
|
|
* 'my_objec.rodata', taking first 8 characters of object name and
|
|
* entire 7 characters of '.rodata'.
|
|
* Somewhat confusingly, if internal map ELF section name is shorter
|
|
* than 7 characters, e.g., '.bss', we still reserve 7 characters
|
|
* for the suffix, even though we only have 4 actual characters, and
|
|
* resulting map will be called 'my_objec.bss', not even using all 15
|
|
* characters allowed by the kernel. Oh well, at least the truncated
|
|
* object name is somewhat consistent in this case. But if the map
|
|
* name is '.kconfig', we'll still have entirety of '.kconfig' added
|
|
* (8 chars) and thus will be left with only first 7 characters of the
|
|
* object name ('my_obje'). Happy guessing, user, that the final map
|
|
* name will be "my_obje.kconfig".
|
|
* Now, with libbpf starting to support arbitrarily named .rodata.*
|
|
* and .data.* data sections, it's possible that ELF section name is
|
|
* longer than allowed 15 chars, so we now need to be careful to take
|
|
* only up to 15 first characters of ELF name, taking no BPF object
|
|
* name characters at all. So '.rodata.abracadabra' will result in
|
|
* '.rodata.abracad' kernel and user-visible name.
|
|
* We need to keep this convoluted logic intact for .data, .bss and
|
|
* .rodata maps, but for new custom .data.custom and .rodata.custom
|
|
* maps we use their ELF names as is, not prepending bpf_object name
|
|
* in front. We still need to truncate them to 15 characters for the
|
|
* kernel. Full name can be recovered for such maps by using DATASEC
|
|
* BTF type associated with such map's value type, though.
|
|
*/
|
|
if (sfx_len >= BPF_OBJ_NAME_LEN)
|
|
sfx_len = BPF_OBJ_NAME_LEN - 1;
|
|
|
|
/* if there are two or more dots in map name, it's a custom dot map */
|
|
if (strchr(real_name + 1, '.') != NULL)
|
|
pfx_len = 0;
|
|
else
|
|
pfx_len = min((size_t)BPF_OBJ_NAME_LEN - sfx_len - 1, strlen(obj->name));
|
|
|
|
snprintf(map_name, sizeof(map_name), "%.*s%.*s", pfx_len, obj->name,
|
|
sfx_len, real_name);
|
|
|
|
/* sanitise map name to characters allowed by kernel */
|
|
for (p = map_name; *p && p < map_name + sizeof(map_name); p++)
|
|
if (!isalnum(*p) && *p != '_' && *p != '.')
|
|
*p = '_';
|
|
|
|
return strdup(map_name);
|
|
}
|
|
|
|
static int
|
|
bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map);
|
|
|
|
static int
|
|
bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
|
|
const char *real_name, int sec_idx, void *data, size_t data_sz)
|
|
{
|
|
struct bpf_map_def *def;
|
|
struct bpf_map *map;
|
|
int err;
|
|
|
|
map = bpf_object__add_map(obj);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
|
|
map->libbpf_type = type;
|
|
map->sec_idx = sec_idx;
|
|
map->sec_offset = 0;
|
|
map->real_name = strdup(real_name);
|
|
map->name = internal_map_name(obj, real_name);
|
|
if (!map->real_name || !map->name) {
|
|
zfree(&map->real_name);
|
|
zfree(&map->name);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
def = &map->def;
|
|
def->type = BPF_MAP_TYPE_ARRAY;
|
|
def->key_size = sizeof(int);
|
|
def->value_size = data_sz;
|
|
def->max_entries = 1;
|
|
def->map_flags = type == LIBBPF_MAP_RODATA || type == LIBBPF_MAP_KCONFIG
|
|
? BPF_F_RDONLY_PROG : 0;
|
|
def->map_flags |= BPF_F_MMAPABLE;
|
|
|
|
pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n",
|
|
map->name, map->sec_idx, map->sec_offset, def->map_flags);
|
|
|
|
map->mmaped = mmap(NULL, bpf_map_mmap_sz(map), PROT_READ | PROT_WRITE,
|
|
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
|
|
if (map->mmaped == MAP_FAILED) {
|
|
err = -errno;
|
|
map->mmaped = NULL;
|
|
pr_warn("failed to alloc map '%s' content buffer: %d\n",
|
|
map->name, err);
|
|
zfree(&map->real_name);
|
|
zfree(&map->name);
|
|
return err;
|
|
}
|
|
|
|
/* failures are fine because of maps like .rodata.str1.1 */
|
|
(void) bpf_map_find_btf_info(obj, map);
|
|
|
|
if (data)
|
|
memcpy(map->mmaped, data, data_sz);
|
|
|
|
pr_debug("map %td is \"%s\"\n", map - obj->maps, map->name);
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__init_global_data_maps(struct bpf_object *obj)
|
|
{
|
|
struct elf_sec_desc *sec_desc;
|
|
const char *sec_name;
|
|
int err = 0, sec_idx;
|
|
|
|
/*
|
|
* Populate obj->maps with libbpf internal maps.
|
|
*/
|
|
for (sec_idx = 1; sec_idx < obj->efile.sec_cnt; sec_idx++) {
|
|
sec_desc = &obj->efile.secs[sec_idx];
|
|
|
|
switch (sec_desc->sec_type) {
|
|
case SEC_DATA:
|
|
sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx));
|
|
err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA,
|
|
sec_name, sec_idx,
|
|
sec_desc->data->d_buf,
|
|
sec_desc->data->d_size);
|
|
break;
|
|
case SEC_RODATA:
|
|
obj->has_rodata = true;
|
|
sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx));
|
|
err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA,
|
|
sec_name, sec_idx,
|
|
sec_desc->data->d_buf,
|
|
sec_desc->data->d_size);
|
|
break;
|
|
case SEC_BSS:
|
|
sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx));
|
|
err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS,
|
|
sec_name, sec_idx,
|
|
NULL,
|
|
sec_desc->data->d_size);
|
|
break;
|
|
default:
|
|
/* skip */
|
|
break;
|
|
}
|
|
if (err)
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
static struct extern_desc *find_extern_by_name(const struct bpf_object *obj,
|
|
const void *name)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < obj->nr_extern; i++) {
|
|
if (strcmp(obj->externs[i].name, name) == 0)
|
|
return &obj->externs[i];
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val,
|
|
char value)
|
|
{
|
|
switch (ext->kcfg.type) {
|
|
case KCFG_BOOL:
|
|
if (value == 'm') {
|
|
pr_warn("extern (kcfg) %s=%c should be tristate or char\n",
|
|
ext->name, value);
|
|
return -EINVAL;
|
|
}
|
|
*(bool *)ext_val = value == 'y' ? true : false;
|
|
break;
|
|
case KCFG_TRISTATE:
|
|
if (value == 'y')
|
|
*(enum libbpf_tristate *)ext_val = TRI_YES;
|
|
else if (value == 'm')
|
|
*(enum libbpf_tristate *)ext_val = TRI_MODULE;
|
|
else /* value == 'n' */
|
|
*(enum libbpf_tristate *)ext_val = TRI_NO;
|
|
break;
|
|
case KCFG_CHAR:
|
|
*(char *)ext_val = value;
|
|
break;
|
|
case KCFG_UNKNOWN:
|
|
case KCFG_INT:
|
|
case KCFG_CHAR_ARR:
|
|
default:
|
|
pr_warn("extern (kcfg) %s=%c should be bool, tristate, or char\n",
|
|
ext->name, value);
|
|
return -EINVAL;
|
|
}
|
|
ext->is_set = true;
|
|
return 0;
|
|
}
|
|
|
|
static int set_kcfg_value_str(struct extern_desc *ext, char *ext_val,
|
|
const char *value)
|
|
{
|
|
size_t len;
|
|
|
|
if (ext->kcfg.type != KCFG_CHAR_ARR) {
|
|
pr_warn("extern (kcfg) %s=%s should be char array\n", ext->name, value);
|
|
return -EINVAL;
|
|
}
|
|
|
|
len = strlen(value);
|
|
if (value[len - 1] != '"') {
|
|
pr_warn("extern (kcfg) '%s': invalid string config '%s'\n",
|
|
ext->name, value);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* strip quotes */
|
|
len -= 2;
|
|
if (len >= ext->kcfg.sz) {
|
|
pr_warn("extern (kcfg) '%s': long string config %s of (%zu bytes) truncated to %d bytes\n",
|
|
ext->name, value, len, ext->kcfg.sz - 1);
|
|
len = ext->kcfg.sz - 1;
|
|
}
|
|
memcpy(ext_val, value + 1, len);
|
|
ext_val[len] = '\0';
|
|
ext->is_set = true;
|
|
return 0;
|
|
}
|
|
|
|
static int parse_u64(const char *value, __u64 *res)
|
|
{
|
|
char *value_end;
|
|
int err;
|
|
|
|
errno = 0;
|
|
*res = strtoull(value, &value_end, 0);
|
|
if (errno) {
|
|
err = -errno;
|
|
pr_warn("failed to parse '%s' as integer: %d\n", value, err);
|
|
return err;
|
|
}
|
|
if (*value_end) {
|
|
pr_warn("failed to parse '%s' as integer completely\n", value);
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static bool is_kcfg_value_in_range(const struct extern_desc *ext, __u64 v)
|
|
{
|
|
int bit_sz = ext->kcfg.sz * 8;
|
|
|
|
if (ext->kcfg.sz == 8)
|
|
return true;
|
|
|
|
/* Validate that value stored in u64 fits in integer of `ext->sz`
|
|
* bytes size without any loss of information. If the target integer
|
|
* is signed, we rely on the following limits of integer type of
|
|
* Y bits and subsequent transformation:
|
|
*
|
|
* -2^(Y-1) <= X <= 2^(Y-1) - 1
|
|
* 0 <= X + 2^(Y-1) <= 2^Y - 1
|
|
* 0 <= X + 2^(Y-1) < 2^Y
|
|
*
|
|
* For unsigned target integer, check that all the (64 - Y) bits are
|
|
* zero.
|
|
*/
|
|
if (ext->kcfg.is_signed)
|
|
return v + (1ULL << (bit_sz - 1)) < (1ULL << bit_sz);
|
|
else
|
|
return (v >> bit_sz) == 0;
|
|
}
|
|
|
|
static int set_kcfg_value_num(struct extern_desc *ext, void *ext_val,
|
|
__u64 value)
|
|
{
|
|
if (ext->kcfg.type != KCFG_INT && ext->kcfg.type != KCFG_CHAR) {
|
|
pr_warn("extern (kcfg) %s=%llu should be integer\n",
|
|
ext->name, (unsigned long long)value);
|
|
return -EINVAL;
|
|
}
|
|
if (!is_kcfg_value_in_range(ext, value)) {
|
|
pr_warn("extern (kcfg) %s=%llu value doesn't fit in %d bytes\n",
|
|
ext->name, (unsigned long long)value, ext->kcfg.sz);
|
|
return -ERANGE;
|
|
}
|
|
switch (ext->kcfg.sz) {
|
|
case 1: *(__u8 *)ext_val = value; break;
|
|
case 2: *(__u16 *)ext_val = value; break;
|
|
case 4: *(__u32 *)ext_val = value; break;
|
|
case 8: *(__u64 *)ext_val = value; break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
ext->is_set = true;
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__process_kconfig_line(struct bpf_object *obj,
|
|
char *buf, void *data)
|
|
{
|
|
struct extern_desc *ext;
|
|
char *sep, *value;
|
|
int len, err = 0;
|
|
void *ext_val;
|
|
__u64 num;
|
|
|
|
if (!str_has_pfx(buf, "CONFIG_"))
|
|
return 0;
|
|
|
|
sep = strchr(buf, '=');
|
|
if (!sep) {
|
|
pr_warn("failed to parse '%s': no separator\n", buf);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Trim ending '\n' */
|
|
len = strlen(buf);
|
|
if (buf[len - 1] == '\n')
|
|
buf[len - 1] = '\0';
|
|
/* Split on '=' and ensure that a value is present. */
|
|
*sep = '\0';
|
|
if (!sep[1]) {
|
|
*sep = '=';
|
|
pr_warn("failed to parse '%s': no value\n", buf);
|
|
return -EINVAL;
|
|
}
|
|
|
|
ext = find_extern_by_name(obj, buf);
|
|
if (!ext || ext->is_set)
|
|
return 0;
|
|
|
|
ext_val = data + ext->kcfg.data_off;
|
|
value = sep + 1;
|
|
|
|
switch (*value) {
|
|
case 'y': case 'n': case 'm':
|
|
err = set_kcfg_value_tri(ext, ext_val, *value);
|
|
break;
|
|
case '"':
|
|
err = set_kcfg_value_str(ext, ext_val, value);
|
|
break;
|
|
default:
|
|
/* assume integer */
|
|
err = parse_u64(value, &num);
|
|
if (err) {
|
|
pr_warn("extern (kcfg) %s=%s should be integer\n",
|
|
ext->name, value);
|
|
return err;
|
|
}
|
|
err = set_kcfg_value_num(ext, ext_val, num);
|
|
break;
|
|
}
|
|
if (err)
|
|
return err;
|
|
pr_debug("extern (kcfg) %s=%s\n", ext->name, value);
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__read_kconfig_file(struct bpf_object *obj, void *data)
|
|
{
|
|
char buf[PATH_MAX];
|
|
struct utsname uts;
|
|
int len, err = 0;
|
|
gzFile file;
|
|
|
|
uname(&uts);
|
|
len = snprintf(buf, PATH_MAX, "/boot/config-%s", uts.release);
|
|
if (len < 0)
|
|
return -EINVAL;
|
|
else if (len >= PATH_MAX)
|
|
return -ENAMETOOLONG;
|
|
|
|
/* gzopen also accepts uncompressed files. */
|
|
file = gzopen(buf, "r");
|
|
if (!file)
|
|
file = gzopen("/proc/config.gz", "r");
|
|
|
|
if (!file) {
|
|
pr_warn("failed to open system Kconfig\n");
|
|
return -ENOENT;
|
|
}
|
|
|
|
while (gzgets(file, buf, sizeof(buf))) {
|
|
err = bpf_object__process_kconfig_line(obj, buf, data);
|
|
if (err) {
|
|
pr_warn("error parsing system Kconfig line '%s': %d\n",
|
|
buf, err);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
out:
|
|
gzclose(file);
|
|
return err;
|
|
}
|
|
|
|
static int bpf_object__read_kconfig_mem(struct bpf_object *obj,
|
|
const char *config, void *data)
|
|
{
|
|
char buf[PATH_MAX];
|
|
int err = 0;
|
|
FILE *file;
|
|
|
|
file = fmemopen((void *)config, strlen(config), "r");
|
|
if (!file) {
|
|
err = -errno;
|
|
pr_warn("failed to open in-memory Kconfig: %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
while (fgets(buf, sizeof(buf), file)) {
|
|
err = bpf_object__process_kconfig_line(obj, buf, data);
|
|
if (err) {
|
|
pr_warn("error parsing in-memory Kconfig line '%s': %d\n",
|
|
buf, err);
|
|
break;
|
|
}
|
|
}
|
|
|
|
fclose(file);
|
|
return err;
|
|
}
|
|
|
|
static int bpf_object__init_kconfig_map(struct bpf_object *obj)
|
|
{
|
|
struct extern_desc *last_ext = NULL, *ext;
|
|
size_t map_sz;
|
|
int i, err;
|
|
|
|
for (i = 0; i < obj->nr_extern; i++) {
|
|
ext = &obj->externs[i];
|
|
if (ext->type == EXT_KCFG)
|
|
last_ext = ext;
|
|
}
|
|
|
|
if (!last_ext)
|
|
return 0;
|
|
|
|
map_sz = last_ext->kcfg.data_off + last_ext->kcfg.sz;
|
|
err = bpf_object__init_internal_map(obj, LIBBPF_MAP_KCONFIG,
|
|
".kconfig", obj->efile.symbols_shndx,
|
|
NULL, map_sz);
|
|
if (err)
|
|
return err;
|
|
|
|
obj->kconfig_map_idx = obj->nr_maps - 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
|
|
{
|
|
Elf_Data *symbols = obj->efile.symbols;
|
|
int i, map_def_sz = 0, nr_maps = 0, nr_syms;
|
|
Elf_Data *data = NULL;
|
|
Elf_Scn *scn;
|
|
|
|
if (obj->efile.maps_shndx < 0)
|
|
return 0;
|
|
|
|
if (libbpf_mode & LIBBPF_STRICT_MAP_DEFINITIONS) {
|
|
pr_warn("legacy map definitions in SEC(\"maps\") are not supported\n");
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
if (!symbols)
|
|
return -EINVAL;
|
|
|
|
scn = elf_sec_by_idx(obj, obj->efile.maps_shndx);
|
|
data = elf_sec_data(obj, scn);
|
|
if (!scn || !data) {
|
|
pr_warn("elf: failed to get legacy map definitions for %s\n",
|
|
obj->path);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Count number of maps. Each map has a name.
|
|
* Array of maps is not supported: only the first element is
|
|
* considered.
|
|
*
|
|
* TODO: Detect array of map and report error.
|
|
*/
|
|
nr_syms = symbols->d_size / sizeof(Elf64_Sym);
|
|
for (i = 0; i < nr_syms; i++) {
|
|
Elf64_Sym *sym = elf_sym_by_idx(obj, i);
|
|
|
|
if (sym->st_shndx != obj->efile.maps_shndx)
|
|
continue;
|
|
if (ELF64_ST_TYPE(sym->st_info) == STT_SECTION)
|
|
continue;
|
|
nr_maps++;
|
|
}
|
|
/* Assume equally sized map definitions */
|
|
pr_debug("elf: found %d legacy map definitions (%zd bytes) in %s\n",
|
|
nr_maps, data->d_size, obj->path);
|
|
|
|
if (!data->d_size || nr_maps == 0 || (data->d_size % nr_maps) != 0) {
|
|
pr_warn("elf: unable to determine legacy map definition size in %s\n",
|
|
obj->path);
|
|
return -EINVAL;
|
|
}
|
|
map_def_sz = data->d_size / nr_maps;
|
|
|
|
/* Fill obj->maps using data in "maps" section. */
|
|
for (i = 0; i < nr_syms; i++) {
|
|
Elf64_Sym *sym = elf_sym_by_idx(obj, i);
|
|
const char *map_name;
|
|
struct bpf_map_def *def;
|
|
struct bpf_map *map;
|
|
|
|
if (sym->st_shndx != obj->efile.maps_shndx)
|
|
continue;
|
|
if (ELF64_ST_TYPE(sym->st_info) == STT_SECTION)
|
|
continue;
|
|
|
|
map = bpf_object__add_map(obj);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
|
|
map_name = elf_sym_str(obj, sym->st_name);
|
|
if (!map_name) {
|
|
pr_warn("failed to get map #%d name sym string for obj %s\n",
|
|
i, obj->path);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
pr_warn("map '%s' (legacy): legacy map definitions are deprecated, use BTF-defined maps instead\n", map_name);
|
|
|
|
if (ELF64_ST_BIND(sym->st_info) == STB_LOCAL) {
|
|
pr_warn("map '%s' (legacy): static maps are not supported\n", map_name);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
map->libbpf_type = LIBBPF_MAP_UNSPEC;
|
|
map->sec_idx = sym->st_shndx;
|
|
map->sec_offset = sym->st_value;
|
|
pr_debug("map '%s' (legacy): at sec_idx %d, offset %zu.\n",
|
|
map_name, map->sec_idx, map->sec_offset);
|
|
if (sym->st_value + map_def_sz > data->d_size) {
|
|
pr_warn("corrupted maps section in %s: last map \"%s\" too small\n",
|
|
obj->path, map_name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
map->name = strdup(map_name);
|
|
if (!map->name) {
|
|
pr_warn("map '%s': failed to alloc map name\n", map_name);
|
|
return -ENOMEM;
|
|
}
|
|
pr_debug("map %d is \"%s\"\n", i, map->name);
|
|
def = (struct bpf_map_def *)(data->d_buf + sym->st_value);
|
|
/*
|
|
* If the definition of the map in the object file fits in
|
|
* bpf_map_def, copy it. Any extra fields in our version
|
|
* of bpf_map_def will default to zero as a result of the
|
|
* calloc above.
|
|
*/
|
|
if (map_def_sz <= sizeof(struct bpf_map_def)) {
|
|
memcpy(&map->def, def, map_def_sz);
|
|
} else {
|
|
/*
|
|
* Here the map structure being read is bigger than what
|
|
* we expect, truncate if the excess bits are all zero.
|
|
* If they are not zero, reject this map as
|
|
* incompatible.
|
|
*/
|
|
char *b;
|
|
|
|
for (b = ((char *)def) + sizeof(struct bpf_map_def);
|
|
b < ((char *)def) + map_def_sz; b++) {
|
|
if (*b != 0) {
|
|
pr_warn("maps section in %s: \"%s\" has unrecognized, non-zero options\n",
|
|
obj->path, map_name);
|
|
if (strict)
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
memcpy(&map->def, def, sizeof(struct bpf_map_def));
|
|
}
|
|
|
|
/* btf info may not exist but fill it in if it does exist */
|
|
(void) bpf_map_find_btf_info(obj, map);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
const struct btf_type *
|
|
skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id)
|
|
{
|
|
const struct btf_type *t = btf__type_by_id(btf, id);
|
|
|
|
if (res_id)
|
|
*res_id = id;
|
|
|
|
while (btf_is_mod(t) || btf_is_typedef(t)) {
|
|
if (res_id)
|
|
*res_id = t->type;
|
|
t = btf__type_by_id(btf, t->type);
|
|
}
|
|
|
|
return t;
|
|
}
|
|
|
|
static const struct btf_type *
|
|
resolve_func_ptr(const struct btf *btf, __u32 id, __u32 *res_id)
|
|
{
|
|
const struct btf_type *t;
|
|
|
|
t = skip_mods_and_typedefs(btf, id, NULL);
|
|
if (!btf_is_ptr(t))
|
|
return NULL;
|
|
|
|
t = skip_mods_and_typedefs(btf, t->type, res_id);
|
|
|
|
return btf_is_func_proto(t) ? t : NULL;
|
|
}
|
|
|
|
static const char *__btf_kind_str(__u16 kind)
|
|
{
|
|
switch (kind) {
|
|
case BTF_KIND_UNKN: return "void";
|
|
case BTF_KIND_INT: return "int";
|
|
case BTF_KIND_PTR: return "ptr";
|
|
case BTF_KIND_ARRAY: return "array";
|
|
case BTF_KIND_STRUCT: return "struct";
|
|
case BTF_KIND_UNION: return "union";
|
|
case BTF_KIND_ENUM: return "enum";
|
|
case BTF_KIND_FWD: return "fwd";
|
|
case BTF_KIND_TYPEDEF: return "typedef";
|
|
case BTF_KIND_VOLATILE: return "volatile";
|
|
case BTF_KIND_CONST: return "const";
|
|
case BTF_KIND_RESTRICT: return "restrict";
|
|
case BTF_KIND_FUNC: return "func";
|
|
case BTF_KIND_FUNC_PROTO: return "func_proto";
|
|
case BTF_KIND_VAR: return "var";
|
|
case BTF_KIND_DATASEC: return "datasec";
|
|
case BTF_KIND_FLOAT: return "float";
|
|
case BTF_KIND_DECL_TAG: return "decl_tag";
|
|
case BTF_KIND_TYPE_TAG: return "type_tag";
|
|
default: return "unknown";
|
|
}
|
|
}
|
|
|
|
const char *btf_kind_str(const struct btf_type *t)
|
|
{
|
|
return __btf_kind_str(btf_kind(t));
|
|
}
|
|
|
|
/*
|
|
* Fetch integer attribute of BTF map definition. Such attributes are
|
|
* represented using a pointer to an array, in which dimensionality of array
|
|
* encodes specified integer value. E.g., int (*type)[BPF_MAP_TYPE_ARRAY];
|
|
* encodes `type => BPF_MAP_TYPE_ARRAY` key/value pair completely using BTF
|
|
* type definition, while using only sizeof(void *) space in ELF data section.
|
|
*/
|
|
static bool get_map_field_int(const char *map_name, const struct btf *btf,
|
|
const struct btf_member *m, __u32 *res)
|
|
{
|
|
const struct btf_type *t = skip_mods_and_typedefs(btf, m->type, NULL);
|
|
const char *name = btf__name_by_offset(btf, m->name_off);
|
|
const struct btf_array *arr_info;
|
|
const struct btf_type *arr_t;
|
|
|
|
if (!btf_is_ptr(t)) {
|
|
pr_warn("map '%s': attr '%s': expected PTR, got %s.\n",
|
|
map_name, name, btf_kind_str(t));
|
|
return false;
|
|
}
|
|
|
|
arr_t = btf__type_by_id(btf, t->type);
|
|
if (!arr_t) {
|
|
pr_warn("map '%s': attr '%s': type [%u] not found.\n",
|
|
map_name, name, t->type);
|
|
return false;
|
|
}
|
|
if (!btf_is_array(arr_t)) {
|
|
pr_warn("map '%s': attr '%s': expected ARRAY, got %s.\n",
|
|
map_name, name, btf_kind_str(arr_t));
|
|
return false;
|
|
}
|
|
arr_info = btf_array(arr_t);
|
|
*res = arr_info->nelems;
|
|
return true;
|
|
}
|
|
|
|
static int build_map_pin_path(struct bpf_map *map, const char *path)
|
|
{
|
|
char buf[PATH_MAX];
|
|
int len;
|
|
|
|
if (!path)
|
|
path = "/sys/fs/bpf";
|
|
|
|
len = snprintf(buf, PATH_MAX, "%s/%s", path, bpf_map__name(map));
|
|
if (len < 0)
|
|
return -EINVAL;
|
|
else if (len >= PATH_MAX)
|
|
return -ENAMETOOLONG;
|
|
|
|
return bpf_map__set_pin_path(map, buf);
|
|
}
|
|
|
|
int parse_btf_map_def(const char *map_name, struct btf *btf,
|
|
const struct btf_type *def_t, bool strict,
|
|
struct btf_map_def *map_def, struct btf_map_def *inner_def)
|
|
{
|
|
const struct btf_type *t;
|
|
const struct btf_member *m;
|
|
bool is_inner = inner_def == NULL;
|
|
int vlen, i;
|
|
|
|
vlen = btf_vlen(def_t);
|
|
m = btf_members(def_t);
|
|
for (i = 0; i < vlen; i++, m++) {
|
|
const char *name = btf__name_by_offset(btf, m->name_off);
|
|
|
|
if (!name) {
|
|
pr_warn("map '%s': invalid field #%d.\n", map_name, i);
|
|
return -EINVAL;
|
|
}
|
|
if (strcmp(name, "type") == 0) {
|
|
if (!get_map_field_int(map_name, btf, m, &map_def->map_type))
|
|
return -EINVAL;
|
|
map_def->parts |= MAP_DEF_MAP_TYPE;
|
|
} else if (strcmp(name, "max_entries") == 0) {
|
|
if (!get_map_field_int(map_name, btf, m, &map_def->max_entries))
|
|
return -EINVAL;
|
|
map_def->parts |= MAP_DEF_MAX_ENTRIES;
|
|
} else if (strcmp(name, "map_flags") == 0) {
|
|
if (!get_map_field_int(map_name, btf, m, &map_def->map_flags))
|
|
return -EINVAL;
|
|
map_def->parts |= MAP_DEF_MAP_FLAGS;
|
|
} else if (strcmp(name, "numa_node") == 0) {
|
|
if (!get_map_field_int(map_name, btf, m, &map_def->numa_node))
|
|
return -EINVAL;
|
|
map_def->parts |= MAP_DEF_NUMA_NODE;
|
|
} else if (strcmp(name, "key_size") == 0) {
|
|
__u32 sz;
|
|
|
|
if (!get_map_field_int(map_name, btf, m, &sz))
|
|
return -EINVAL;
|
|
if (map_def->key_size && map_def->key_size != sz) {
|
|
pr_warn("map '%s': conflicting key size %u != %u.\n",
|
|
map_name, map_def->key_size, sz);
|
|
return -EINVAL;
|
|
}
|
|
map_def->key_size = sz;
|
|
map_def->parts |= MAP_DEF_KEY_SIZE;
|
|
} else if (strcmp(name, "key") == 0) {
|
|
__s64 sz;
|
|
|
|
t = btf__type_by_id(btf, m->type);
|
|
if (!t) {
|
|
pr_warn("map '%s': key type [%d] not found.\n",
|
|
map_name, m->type);
|
|
return -EINVAL;
|
|
}
|
|
if (!btf_is_ptr(t)) {
|
|
pr_warn("map '%s': key spec is not PTR: %s.\n",
|
|
map_name, btf_kind_str(t));
|
|
return -EINVAL;
|
|
}
|
|
sz = btf__resolve_size(btf, t->type);
|
|
if (sz < 0) {
|
|
pr_warn("map '%s': can't determine key size for type [%u]: %zd.\n",
|
|
map_name, t->type, (ssize_t)sz);
|
|
return sz;
|
|
}
|
|
if (map_def->key_size && map_def->key_size != sz) {
|
|
pr_warn("map '%s': conflicting key size %u != %zd.\n",
|
|
map_name, map_def->key_size, (ssize_t)sz);
|
|
return -EINVAL;
|
|
}
|
|
map_def->key_size = sz;
|
|
map_def->key_type_id = t->type;
|
|
map_def->parts |= MAP_DEF_KEY_SIZE | MAP_DEF_KEY_TYPE;
|
|
} else if (strcmp(name, "value_size") == 0) {
|
|
__u32 sz;
|
|
|
|
if (!get_map_field_int(map_name, btf, m, &sz))
|
|
return -EINVAL;
|
|
if (map_def->value_size && map_def->value_size != sz) {
|
|
pr_warn("map '%s': conflicting value size %u != %u.\n",
|
|
map_name, map_def->value_size, sz);
|
|
return -EINVAL;
|
|
}
|
|
map_def->value_size = sz;
|
|
map_def->parts |= MAP_DEF_VALUE_SIZE;
|
|
} else if (strcmp(name, "value") == 0) {
|
|
__s64 sz;
|
|
|
|
t = btf__type_by_id(btf, m->type);
|
|
if (!t) {
|
|
pr_warn("map '%s': value type [%d] not found.\n",
|
|
map_name, m->type);
|
|
return -EINVAL;
|
|
}
|
|
if (!btf_is_ptr(t)) {
|
|
pr_warn("map '%s': value spec is not PTR: %s.\n",
|
|
map_name, btf_kind_str(t));
|
|
return -EINVAL;
|
|
}
|
|
sz = btf__resolve_size(btf, t->type);
|
|
if (sz < 0) {
|
|
pr_warn("map '%s': can't determine value size for type [%u]: %zd.\n",
|
|
map_name, t->type, (ssize_t)sz);
|
|
return sz;
|
|
}
|
|
if (map_def->value_size && map_def->value_size != sz) {
|
|
pr_warn("map '%s': conflicting value size %u != %zd.\n",
|
|
map_name, map_def->value_size, (ssize_t)sz);
|
|
return -EINVAL;
|
|
}
|
|
map_def->value_size = sz;
|
|
map_def->value_type_id = t->type;
|
|
map_def->parts |= MAP_DEF_VALUE_SIZE | MAP_DEF_VALUE_TYPE;
|
|
}
|
|
else if (strcmp(name, "values") == 0) {
|
|
bool is_map_in_map = bpf_map_type__is_map_in_map(map_def->map_type);
|
|
bool is_prog_array = map_def->map_type == BPF_MAP_TYPE_PROG_ARRAY;
|
|
const char *desc = is_map_in_map ? "map-in-map inner" : "prog-array value";
|
|
char inner_map_name[128];
|
|
int err;
|
|
|
|
if (is_inner) {
|
|
pr_warn("map '%s': multi-level inner maps not supported.\n",
|
|
map_name);
|
|
return -ENOTSUP;
|
|
}
|
|
if (i != vlen - 1) {
|
|
pr_warn("map '%s': '%s' member should be last.\n",
|
|
map_name, name);
|
|
return -EINVAL;
|
|
}
|
|
if (!is_map_in_map && !is_prog_array) {
|
|
pr_warn("map '%s': should be map-in-map or prog-array.\n",
|
|
map_name);
|
|
return -ENOTSUP;
|
|
}
|
|
if (map_def->value_size && map_def->value_size != 4) {
|
|
pr_warn("map '%s': conflicting value size %u != 4.\n",
|
|
map_name, map_def->value_size);
|
|
return -EINVAL;
|
|
}
|
|
map_def->value_size = 4;
|
|
t = btf__type_by_id(btf, m->type);
|
|
if (!t) {
|
|
pr_warn("map '%s': %s type [%d] not found.\n",
|
|
map_name, desc, m->type);
|
|
return -EINVAL;
|
|
}
|
|
if (!btf_is_array(t) || btf_array(t)->nelems) {
|
|
pr_warn("map '%s': %s spec is not a zero-sized array.\n",
|
|
map_name, desc);
|
|
return -EINVAL;
|
|
}
|
|
t = skip_mods_and_typedefs(btf, btf_array(t)->type, NULL);
|
|
if (!btf_is_ptr(t)) {
|
|
pr_warn("map '%s': %s def is of unexpected kind %s.\n",
|
|
map_name, desc, btf_kind_str(t));
|
|
return -EINVAL;
|
|
}
|
|
t = skip_mods_and_typedefs(btf, t->type, NULL);
|
|
if (is_prog_array) {
|
|
if (!btf_is_func_proto(t)) {
|
|
pr_warn("map '%s': prog-array value def is of unexpected kind %s.\n",
|
|
map_name, btf_kind_str(t));
|
|
return -EINVAL;
|
|
}
|
|
continue;
|
|
}
|
|
if (!btf_is_struct(t)) {
|
|
pr_warn("map '%s': map-in-map inner def is of unexpected kind %s.\n",
|
|
map_name, btf_kind_str(t));
|
|
return -EINVAL;
|
|
}
|
|
|
|
snprintf(inner_map_name, sizeof(inner_map_name), "%s.inner", map_name);
|
|
err = parse_btf_map_def(inner_map_name, btf, t, strict, inner_def, NULL);
|
|
if (err)
|
|
return err;
|
|
|
|
map_def->parts |= MAP_DEF_INNER_MAP;
|
|
} else if (strcmp(name, "pinning") == 0) {
|
|
__u32 val;
|
|
|
|
if (is_inner) {
|
|
pr_warn("map '%s': inner def can't be pinned.\n", map_name);
|
|
return -EINVAL;
|
|
}
|
|
if (!get_map_field_int(map_name, btf, m, &val))
|
|
return -EINVAL;
|
|
if (val != LIBBPF_PIN_NONE && val != LIBBPF_PIN_BY_NAME) {
|
|
pr_warn("map '%s': invalid pinning value %u.\n",
|
|
map_name, val);
|
|
return -EINVAL;
|
|
}
|
|
map_def->pinning = val;
|
|
map_def->parts |= MAP_DEF_PINNING;
|
|
} else if (strcmp(name, "map_extra") == 0) {
|
|
__u32 map_extra;
|
|
|
|
if (!get_map_field_int(map_name, btf, m, &map_extra))
|
|
return -EINVAL;
|
|
map_def->map_extra = map_extra;
|
|
map_def->parts |= MAP_DEF_MAP_EXTRA;
|
|
} else {
|
|
if (strict) {
|
|
pr_warn("map '%s': unknown field '%s'.\n", map_name, name);
|
|
return -ENOTSUP;
|
|
}
|
|
pr_debug("map '%s': ignoring unknown field '%s'.\n", map_name, name);
|
|
}
|
|
}
|
|
|
|
if (map_def->map_type == BPF_MAP_TYPE_UNSPEC) {
|
|
pr_warn("map '%s': map type isn't specified.\n", map_name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void fill_map_from_def(struct bpf_map *map, const struct btf_map_def *def)
|
|
{
|
|
map->def.type = def->map_type;
|
|
map->def.key_size = def->key_size;
|
|
map->def.value_size = def->value_size;
|
|
map->def.max_entries = def->max_entries;
|
|
map->def.map_flags = def->map_flags;
|
|
map->map_extra = def->map_extra;
|
|
|
|
map->numa_node = def->numa_node;
|
|
map->btf_key_type_id = def->key_type_id;
|
|
map->btf_value_type_id = def->value_type_id;
|
|
|
|
if (def->parts & MAP_DEF_MAP_TYPE)
|
|
pr_debug("map '%s': found type = %u.\n", map->name, def->map_type);
|
|
|
|
if (def->parts & MAP_DEF_KEY_TYPE)
|
|
pr_debug("map '%s': found key [%u], sz = %u.\n",
|
|
map->name, def->key_type_id, def->key_size);
|
|
else if (def->parts & MAP_DEF_KEY_SIZE)
|
|
pr_debug("map '%s': found key_size = %u.\n", map->name, def->key_size);
|
|
|
|
if (def->parts & MAP_DEF_VALUE_TYPE)
|
|
pr_debug("map '%s': found value [%u], sz = %u.\n",
|
|
map->name, def->value_type_id, def->value_size);
|
|
else if (def->parts & MAP_DEF_VALUE_SIZE)
|
|
pr_debug("map '%s': found value_size = %u.\n", map->name, def->value_size);
|
|
|
|
if (def->parts & MAP_DEF_MAX_ENTRIES)
|
|
pr_debug("map '%s': found max_entries = %u.\n", map->name, def->max_entries);
|
|
if (def->parts & MAP_DEF_MAP_FLAGS)
|
|
pr_debug("map '%s': found map_flags = 0x%x.\n", map->name, def->map_flags);
|
|
if (def->parts & MAP_DEF_MAP_EXTRA)
|
|
pr_debug("map '%s': found map_extra = 0x%llx.\n", map->name,
|
|
(unsigned long long)def->map_extra);
|
|
if (def->parts & MAP_DEF_PINNING)
|
|
pr_debug("map '%s': found pinning = %u.\n", map->name, def->pinning);
|
|
if (def->parts & MAP_DEF_NUMA_NODE)
|
|
pr_debug("map '%s': found numa_node = %u.\n", map->name, def->numa_node);
|
|
|
|
if (def->parts & MAP_DEF_INNER_MAP)
|
|
pr_debug("map '%s': found inner map definition.\n", map->name);
|
|
}
|
|
|
|
static const char *btf_var_linkage_str(__u32 linkage)
|
|
{
|
|
switch (linkage) {
|
|
case BTF_VAR_STATIC: return "static";
|
|
case BTF_VAR_GLOBAL_ALLOCATED: return "global";
|
|
case BTF_VAR_GLOBAL_EXTERN: return "extern";
|
|
default: return "unknown";
|
|
}
|
|
}
|
|
|
|
static int bpf_object__init_user_btf_map(struct bpf_object *obj,
|
|
const struct btf_type *sec,
|
|
int var_idx, int sec_idx,
|
|
const Elf_Data *data, bool strict,
|
|
const char *pin_root_path)
|
|
{
|
|
struct btf_map_def map_def = {}, inner_def = {};
|
|
const struct btf_type *var, *def;
|
|
const struct btf_var_secinfo *vi;
|
|
const struct btf_var *var_extra;
|
|
const char *map_name;
|
|
struct bpf_map *map;
|
|
int err;
|
|
|
|
vi = btf_var_secinfos(sec) + var_idx;
|
|
var = btf__type_by_id(obj->btf, vi->type);
|
|
var_extra = btf_var(var);
|
|
map_name = btf__name_by_offset(obj->btf, var->name_off);
|
|
|
|
if (map_name == NULL || map_name[0] == '\0') {
|
|
pr_warn("map #%d: empty name.\n", var_idx);
|
|
return -EINVAL;
|
|
}
|
|
if ((__u64)vi->offset + vi->size > data->d_size) {
|
|
pr_warn("map '%s' BTF data is corrupted.\n", map_name);
|
|
return -EINVAL;
|
|
}
|
|
if (!btf_is_var(var)) {
|
|
pr_warn("map '%s': unexpected var kind %s.\n",
|
|
map_name, btf_kind_str(var));
|
|
return -EINVAL;
|
|
}
|
|
if (var_extra->linkage != BTF_VAR_GLOBAL_ALLOCATED) {
|
|
pr_warn("map '%s': unsupported map linkage %s.\n",
|
|
map_name, btf_var_linkage_str(var_extra->linkage));
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
def = skip_mods_and_typedefs(obj->btf, var->type, NULL);
|
|
if (!btf_is_struct(def)) {
|
|
pr_warn("map '%s': unexpected def kind %s.\n",
|
|
map_name, btf_kind_str(var));
|
|
return -EINVAL;
|
|
}
|
|
if (def->size > vi->size) {
|
|
pr_warn("map '%s': invalid def size.\n", map_name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
map = bpf_object__add_map(obj);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
map->name = strdup(map_name);
|
|
if (!map->name) {
|
|
pr_warn("map '%s': failed to alloc map name.\n", map_name);
|
|
return -ENOMEM;
|
|
}
|
|
map->libbpf_type = LIBBPF_MAP_UNSPEC;
|
|
map->def.type = BPF_MAP_TYPE_UNSPEC;
|
|
map->sec_idx = sec_idx;
|
|
map->sec_offset = vi->offset;
|
|
map->btf_var_idx = var_idx;
|
|
pr_debug("map '%s': at sec_idx %d, offset %zu.\n",
|
|
map_name, map->sec_idx, map->sec_offset);
|
|
|
|
err = parse_btf_map_def(map->name, obj->btf, def, strict, &map_def, &inner_def);
|
|
if (err)
|
|
return err;
|
|
|
|
fill_map_from_def(map, &map_def);
|
|
|
|
if (map_def.pinning == LIBBPF_PIN_BY_NAME) {
|
|
err = build_map_pin_path(map, pin_root_path);
|
|
if (err) {
|
|
pr_warn("map '%s': couldn't build pin path.\n", map->name);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
if (map_def.parts & MAP_DEF_INNER_MAP) {
|
|
map->inner_map = calloc(1, sizeof(*map->inner_map));
|
|
if (!map->inner_map)
|
|
return -ENOMEM;
|
|
map->inner_map->fd = -1;
|
|
map->inner_map->sec_idx = sec_idx;
|
|
map->inner_map->name = malloc(strlen(map_name) + sizeof(".inner") + 1);
|
|
if (!map->inner_map->name)
|
|
return -ENOMEM;
|
|
sprintf(map->inner_map->name, "%s.inner", map_name);
|
|
|
|
fill_map_from_def(map->inner_map, &inner_def);
|
|
}
|
|
|
|
err = bpf_map_find_btf_info(obj, map);
|
|
if (err)
|
|
return err;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict,
|
|
const char *pin_root_path)
|
|
{
|
|
const struct btf_type *sec = NULL;
|
|
int nr_types, i, vlen, err;
|
|
const struct btf_type *t;
|
|
const char *name;
|
|
Elf_Data *data;
|
|
Elf_Scn *scn;
|
|
|
|
if (obj->efile.btf_maps_shndx < 0)
|
|
return 0;
|
|
|
|
scn = elf_sec_by_idx(obj, obj->efile.btf_maps_shndx);
|
|
data = elf_sec_data(obj, scn);
|
|
if (!scn || !data) {
|
|
pr_warn("elf: failed to get %s map definitions for %s\n",
|
|
MAPS_ELF_SEC, obj->path);
|
|
return -EINVAL;
|
|
}
|
|
|
|
nr_types = btf__type_cnt(obj->btf);
|
|
for (i = 1; i < nr_types; i++) {
|
|
t = btf__type_by_id(obj->btf, i);
|
|
if (!btf_is_datasec(t))
|
|
continue;
|
|
name = btf__name_by_offset(obj->btf, t->name_off);
|
|
if (strcmp(name, MAPS_ELF_SEC) == 0) {
|
|
sec = t;
|
|
obj->efile.btf_maps_sec_btf_id = i;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!sec) {
|
|
pr_warn("DATASEC '%s' not found.\n", MAPS_ELF_SEC);
|
|
return -ENOENT;
|
|
}
|
|
|
|
vlen = btf_vlen(sec);
|
|
for (i = 0; i < vlen; i++) {
|
|
err = bpf_object__init_user_btf_map(obj, sec, i,
|
|
obj->efile.btf_maps_shndx,
|
|
data, strict,
|
|
pin_root_path);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__init_maps(struct bpf_object *obj,
|
|
const struct bpf_object_open_opts *opts)
|
|
{
|
|
const char *pin_root_path;
|
|
bool strict;
|
|
int err;
|
|
|
|
strict = !OPTS_GET(opts, relaxed_maps, false);
|
|
pin_root_path = OPTS_GET(opts, pin_root_path, NULL);
|
|
|
|
err = bpf_object__init_user_maps(obj, strict);
|
|
err = err ?: bpf_object__init_user_btf_maps(obj, strict, pin_root_path);
|
|
err = err ?: bpf_object__init_global_data_maps(obj);
|
|
err = err ?: bpf_object__init_kconfig_map(obj);
|
|
err = err ?: bpf_object__init_struct_ops_maps(obj);
|
|
|
|
return err;
|
|
}
|
|
|
|
static bool section_have_execinstr(struct bpf_object *obj, int idx)
|
|
{
|
|
Elf64_Shdr *sh;
|
|
|
|
sh = elf_sec_hdr(obj, elf_sec_by_idx(obj, idx));
|
|
if (!sh)
|
|
return false;
|
|
|
|
return sh->sh_flags & SHF_EXECINSTR;
|
|
}
|
|
|
|
static bool btf_needs_sanitization(struct bpf_object *obj)
|
|
{
|
|
bool has_func_global = kernel_supports(obj, FEAT_BTF_GLOBAL_FUNC);
|
|
bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC);
|
|
bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT);
|
|
bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
|
|
bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
|
|
bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG);
|
|
|
|
return !has_func || !has_datasec || !has_func_global || !has_float ||
|
|
!has_decl_tag || !has_type_tag;
|
|
}
|
|
|
|
static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
|
|
{
|
|
bool has_func_global = kernel_supports(obj, FEAT_BTF_GLOBAL_FUNC);
|
|
bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC);
|
|
bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT);
|
|
bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
|
|
bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
|
|
bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG);
|
|
struct btf_type *t;
|
|
int i, j, vlen;
|
|
|
|
for (i = 1; i < btf__type_cnt(btf); i++) {
|
|
t = (struct btf_type *)btf__type_by_id(btf, i);
|
|
|
|
if ((!has_datasec && btf_is_var(t)) || (!has_decl_tag && btf_is_decl_tag(t))) {
|
|
/* replace VAR/DECL_TAG with INT */
|
|
t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
|
|
/*
|
|
* using size = 1 is the safest choice, 4 will be too
|
|
* big and cause kernel BTF validation failure if
|
|
* original variable took less than 4 bytes
|
|
*/
|
|
t->size = 1;
|
|
*(int *)(t + 1) = BTF_INT_ENC(0, 0, 8);
|
|
} else if (!has_datasec && btf_is_datasec(t)) {
|
|
/* replace DATASEC with STRUCT */
|
|
const struct btf_var_secinfo *v = btf_var_secinfos(t);
|
|
struct btf_member *m = btf_members(t);
|
|
struct btf_type *vt;
|
|
char *name;
|
|
|
|
name = (char *)btf__name_by_offset(btf, t->name_off);
|
|
while (*name) {
|
|
if (*name == '.')
|
|
*name = '_';
|
|
name++;
|
|
}
|
|
|
|
vlen = btf_vlen(t);
|
|
t->info = BTF_INFO_ENC(BTF_KIND_STRUCT, 0, vlen);
|
|
for (j = 0; j < vlen; j++, v++, m++) {
|
|
/* order of field assignments is important */
|
|
m->offset = v->offset * 8;
|
|
m->type = v->type;
|
|
/* preserve variable name as member name */
|
|
vt = (void *)btf__type_by_id(btf, v->type);
|
|
m->name_off = vt->name_off;
|
|
}
|
|
} else if (!has_func && btf_is_func_proto(t)) {
|
|
/* replace FUNC_PROTO with ENUM */
|
|
vlen = btf_vlen(t);
|
|
t->info = BTF_INFO_ENC(BTF_KIND_ENUM, 0, vlen);
|
|
t->size = sizeof(__u32); /* kernel enforced */
|
|
} else if (!has_func && btf_is_func(t)) {
|
|
/* replace FUNC with TYPEDEF */
|
|
t->info = BTF_INFO_ENC(BTF_KIND_TYPEDEF, 0, 0);
|
|
} else if (!has_func_global && btf_is_func(t)) {
|
|
/* replace BTF_FUNC_GLOBAL with BTF_FUNC_STATIC */
|
|
t->info = BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0);
|
|
} else if (!has_float && btf_is_float(t)) {
|
|
/* replace FLOAT with an equally-sized empty STRUCT;
|
|
* since C compilers do not accept e.g. "float" as a
|
|
* valid struct name, make it anonymous
|
|
*/
|
|
t->name_off = 0;
|
|
t->info = BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 0);
|
|
} else if (!has_type_tag && btf_is_type_tag(t)) {
|
|
/* replace TYPE_TAG with a CONST */
|
|
t->name_off = 0;
|
|
t->info = BTF_INFO_ENC(BTF_KIND_CONST, 0, 0);
|
|
}
|
|
}
|
|
}
|
|
|
|
static bool libbpf_needs_btf(const struct bpf_object *obj)
|
|
{
|
|
return obj->efile.btf_maps_shndx >= 0 ||
|
|
obj->efile.st_ops_shndx >= 0 ||
|
|
obj->nr_extern > 0;
|
|
}
|
|
|
|
static bool kernel_needs_btf(const struct bpf_object *obj)
|
|
{
|
|
return obj->efile.st_ops_shndx >= 0;
|
|
}
|
|
|
|
static int bpf_object__init_btf(struct bpf_object *obj,
|
|
Elf_Data *btf_data,
|
|
Elf_Data *btf_ext_data)
|
|
{
|
|
int err = -ENOENT;
|
|
|
|
if (btf_data) {
|
|
obj->btf = btf__new(btf_data->d_buf, btf_data->d_size);
|
|
err = libbpf_get_error(obj->btf);
|
|
if (err) {
|
|
obj->btf = NULL;
|
|
pr_warn("Error loading ELF section %s: %d.\n", BTF_ELF_SEC, err);
|
|
goto out;
|
|
}
|
|
/* enforce 8-byte pointers for BPF-targeted BTFs */
|
|
btf__set_pointer_size(obj->btf, 8);
|
|
}
|
|
if (btf_ext_data) {
|
|
struct btf_ext_info *ext_segs[3];
|
|
int seg_num, sec_num;
|
|
|
|
if (!obj->btf) {
|
|
pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
|
|
BTF_EXT_ELF_SEC, BTF_ELF_SEC);
|
|
goto out;
|
|
}
|
|
obj->btf_ext = btf_ext__new(btf_ext_data->d_buf, btf_ext_data->d_size);
|
|
err = libbpf_get_error(obj->btf_ext);
|
|
if (err) {
|
|
pr_warn("Error loading ELF section %s: %d. Ignored and continue.\n",
|
|
BTF_EXT_ELF_SEC, err);
|
|
obj->btf_ext = NULL;
|
|
goto out;
|
|
}
|
|
|
|
/* setup .BTF.ext to ELF section mapping */
|
|
ext_segs[0] = &obj->btf_ext->func_info;
|
|
ext_segs[1] = &obj->btf_ext->line_info;
|
|
ext_segs[2] = &obj->btf_ext->core_relo_info;
|
|
for (seg_num = 0; seg_num < ARRAY_SIZE(ext_segs); seg_num++) {
|
|
struct btf_ext_info *seg = ext_segs[seg_num];
|
|
const struct btf_ext_info_sec *sec;
|
|
const char *sec_name;
|
|
Elf_Scn *scn;
|
|
|
|
if (seg->sec_cnt == 0)
|
|
continue;
|
|
|
|
seg->sec_idxs = calloc(seg->sec_cnt, sizeof(*seg->sec_idxs));
|
|
if (!seg->sec_idxs) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
sec_num = 0;
|
|
for_each_btf_ext_sec(seg, sec) {
|
|
/* preventively increment index to avoid doing
|
|
* this before every continue below
|
|
*/
|
|
sec_num++;
|
|
|
|
sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
|
|
if (str_is_empty(sec_name))
|
|
continue;
|
|
scn = elf_sec_by_name(obj, sec_name);
|
|
if (!scn)
|
|
continue;
|
|
|
|
seg->sec_idxs[sec_num - 1] = elf_ndxscn(scn);
|
|
}
|
|
}
|
|
}
|
|
out:
|
|
if (err && libbpf_needs_btf(obj)) {
|
|
pr_warn("BTF is required, but is missing or corrupted.\n");
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int compare_vsi_off(const void *_a, const void *_b)
|
|
{
|
|
const struct btf_var_secinfo *a = _a;
|
|
const struct btf_var_secinfo *b = _b;
|
|
|
|
return a->offset - b->offset;
|
|
}
|
|
|
|
static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf,
|
|
struct btf_type *t)
|
|
{
|
|
__u32 size = 0, off = 0, i, vars = btf_vlen(t);
|
|
const char *name = btf__name_by_offset(btf, t->name_off);
|
|
const struct btf_type *t_var;
|
|
struct btf_var_secinfo *vsi;
|
|
const struct btf_var *var;
|
|
int ret;
|
|
|
|
if (!name) {
|
|
pr_debug("No name found in string section for DATASEC kind.\n");
|
|
return -ENOENT;
|
|
}
|
|
|
|
/* .extern datasec size and var offsets were set correctly during
|
|
* extern collection step, so just skip straight to sorting variables
|
|
*/
|
|
if (t->size)
|
|
goto sort_vars;
|
|
|
|
ret = find_elf_sec_sz(obj, name, &size);
|
|
if (ret || !size) {
|
|
pr_debug("Invalid size for section %s: %u bytes\n", name, size);
|
|
return -ENOENT;
|
|
}
|
|
|
|
t->size = size;
|
|
|
|
for (i = 0, vsi = btf_var_secinfos(t); i < vars; i++, vsi++) {
|
|
t_var = btf__type_by_id(btf, vsi->type);
|
|
if (!t_var || !btf_is_var(t_var)) {
|
|
pr_debug("Non-VAR type seen in section %s\n", name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
var = btf_var(t_var);
|
|
if (var->linkage == BTF_VAR_STATIC)
|
|
continue;
|
|
|
|
name = btf__name_by_offset(btf, t_var->name_off);
|
|
if (!name) {
|
|
pr_debug("No name found in string section for VAR kind\n");
|
|
return -ENOENT;
|
|
}
|
|
|
|
ret = find_elf_var_offset(obj, name, &off);
|
|
if (ret) {
|
|
pr_debug("No offset found in symbol table for VAR %s\n",
|
|
name);
|
|
return -ENOENT;
|
|
}
|
|
|
|
vsi->offset = off;
|
|
}
|
|
|
|
sort_vars:
|
|
qsort(btf_var_secinfos(t), vars, sizeof(*vsi), compare_vsi_off);
|
|
return 0;
|
|
}
|
|
|
|
static int btf_finalize_data(struct bpf_object *obj, struct btf *btf)
|
|
{
|
|
int err = 0;
|
|
__u32 i, n = btf__type_cnt(btf);
|
|
|
|
for (i = 1; i < n; i++) {
|
|
struct btf_type *t = btf_type_by_id(btf, i);
|
|
|
|
/* Loader needs to fix up some of the things compiler
|
|
* couldn't get its hands on while emitting BTF. This
|
|
* is section size and global variable offset. We use
|
|
* the info from the ELF itself for this purpose.
|
|
*/
|
|
if (btf_is_datasec(t)) {
|
|
err = btf_fixup_datasec(obj, btf, t);
|
|
if (err)
|
|
break;
|
|
}
|
|
}
|
|
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
int btf__finalize_data(struct bpf_object *obj, struct btf *btf)
|
|
{
|
|
return btf_finalize_data(obj, btf);
|
|
}
|
|
|
|
static int bpf_object__finalize_btf(struct bpf_object *obj)
|
|
{
|
|
int err;
|
|
|
|
if (!obj->btf)
|
|
return 0;
|
|
|
|
err = btf_finalize_data(obj, obj->btf);
|
|
if (err) {
|
|
pr_warn("Error finalizing %s: %d.\n", BTF_ELF_SEC, err);
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool prog_needs_vmlinux_btf(struct bpf_program *prog)
|
|
{
|
|
if (prog->type == BPF_PROG_TYPE_STRUCT_OPS ||
|
|
prog->type == BPF_PROG_TYPE_LSM)
|
|
return true;
|
|
|
|
/* BPF_PROG_TYPE_TRACING programs which do not attach to other programs
|
|
* also need vmlinux BTF
|
|
*/
|
|
if (prog->type == BPF_PROG_TYPE_TRACING && !prog->attach_prog_fd)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static bool obj_needs_vmlinux_btf(const struct bpf_object *obj)
|
|
{
|
|
struct bpf_program *prog;
|
|
int i;
|
|
|
|
/* CO-RE relocations need kernel BTF, only when btf_custom_path
|
|
* is not specified
|
|
*/
|
|
if (obj->btf_ext && obj->btf_ext->core_relo_info.len && !obj->btf_custom_path)
|
|
return true;
|
|
|
|
/* Support for typed ksyms needs kernel BTF */
|
|
for (i = 0; i < obj->nr_extern; i++) {
|
|
const struct extern_desc *ext;
|
|
|
|
ext = &obj->externs[i];
|
|
if (ext->type == EXT_KSYM && ext->ksym.type_id)
|
|
return true;
|
|
}
|
|
|
|
bpf_object__for_each_program(prog, obj) {
|
|
if (!prog->autoload)
|
|
continue;
|
|
if (prog_needs_vmlinux_btf(prog))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static int bpf_object__load_vmlinux_btf(struct bpf_object *obj, bool force)
|
|
{
|
|
int err;
|
|
|
|
/* btf_vmlinux could be loaded earlier */
|
|
if (obj->btf_vmlinux || obj->gen_loader)
|
|
return 0;
|
|
|
|
if (!force && !obj_needs_vmlinux_btf(obj))
|
|
return 0;
|
|
|
|
obj->btf_vmlinux = btf__load_vmlinux_btf();
|
|
err = libbpf_get_error(obj->btf_vmlinux);
|
|
if (err) {
|
|
pr_warn("Error loading vmlinux BTF: %d\n", err);
|
|
obj->btf_vmlinux = NULL;
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
|
|
{
|
|
struct btf *kern_btf = obj->btf;
|
|
bool btf_mandatory, sanitize;
|
|
int i, err = 0;
|
|
|
|
if (!obj->btf)
|
|
return 0;
|
|
|
|
if (!kernel_supports(obj, FEAT_BTF)) {
|
|
if (kernel_needs_btf(obj)) {
|
|
err = -EOPNOTSUPP;
|
|
goto report;
|
|
}
|
|
pr_debug("Kernel doesn't support BTF, skipping uploading it.\n");
|
|
return 0;
|
|
}
|
|
|
|
/* Even though some subprogs are global/weak, user might prefer more
|
|
* permissive BPF verification process that BPF verifier performs for
|
|
* static functions, taking into account more context from the caller
|
|
* functions. In such case, they need to mark such subprogs with
|
|
* __attribute__((visibility("hidden"))) and libbpf will adjust
|
|
* corresponding FUNC BTF type to be marked as static and trigger more
|
|
* involved BPF verification process.
|
|
*/
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
struct bpf_program *prog = &obj->programs[i];
|
|
struct btf_type *t;
|
|
const char *name;
|
|
int j, n;
|
|
|
|
if (!prog->mark_btf_static || !prog_is_subprog(obj, prog))
|
|
continue;
|
|
|
|
n = btf__type_cnt(obj->btf);
|
|
for (j = 1; j < n; j++) {
|
|
t = btf_type_by_id(obj->btf, j);
|
|
if (!btf_is_func(t) || btf_func_linkage(t) != BTF_FUNC_GLOBAL)
|
|
continue;
|
|
|
|
name = btf__str_by_offset(obj->btf, t->name_off);
|
|
if (strcmp(name, prog->name) != 0)
|
|
continue;
|
|
|
|
t->info = btf_type_info(BTF_KIND_FUNC, BTF_FUNC_STATIC, 0);
|
|
break;
|
|
}
|
|
}
|
|
|
|
sanitize = btf_needs_sanitization(obj);
|
|
if (sanitize) {
|
|
const void *raw_data;
|
|
__u32 sz;
|
|
|
|
/* clone BTF to sanitize a copy and leave the original intact */
|
|
raw_data = btf__raw_data(obj->btf, &sz);
|
|
kern_btf = btf__new(raw_data, sz);
|
|
err = libbpf_get_error(kern_btf);
|
|
if (err)
|
|
return err;
|
|
|
|
/* enforce 8-byte pointers for BPF-targeted BTFs */
|
|
btf__set_pointer_size(obj->btf, 8);
|
|
bpf_object__sanitize_btf(obj, kern_btf);
|
|
}
|
|
|
|
if (obj->gen_loader) {
|
|
__u32 raw_size = 0;
|
|
const void *raw_data = btf__raw_data(kern_btf, &raw_size);
|
|
|
|
if (!raw_data)
|
|
return -ENOMEM;
|
|
bpf_gen__load_btf(obj->gen_loader, raw_data, raw_size);
|
|
/* Pretend to have valid FD to pass various fd >= 0 checks.
|
|
* This fd == 0 will not be used with any syscall and will be reset to -1 eventually.
|
|
*/
|
|
btf__set_fd(kern_btf, 0);
|
|
} else {
|
|
/* currently BPF_BTF_LOAD only supports log_level 1 */
|
|
err = btf_load_into_kernel(kern_btf, obj->log_buf, obj->log_size,
|
|
obj->log_level ? 1 : 0);
|
|
}
|
|
if (sanitize) {
|
|
if (!err) {
|
|
/* move fd to libbpf's BTF */
|
|
btf__set_fd(obj->btf, btf__fd(kern_btf));
|
|
btf__set_fd(kern_btf, -1);
|
|
}
|
|
btf__free(kern_btf);
|
|
}
|
|
report:
|
|
if (err) {
|
|
btf_mandatory = kernel_needs_btf(obj);
|
|
pr_warn("Error loading .BTF into kernel: %d. %s\n", err,
|
|
btf_mandatory ? "BTF is mandatory, can't proceed."
|
|
: "BTF is optional, ignoring.");
|
|
if (!btf_mandatory)
|
|
err = 0;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static const char *elf_sym_str(const struct bpf_object *obj, size_t off)
|
|
{
|
|
const char *name;
|
|
|
|
name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, off);
|
|
if (!name) {
|
|
pr_warn("elf: failed to get section name string at offset %zu from %s: %s\n",
|
|
off, obj->path, elf_errmsg(-1));
|
|
return NULL;
|
|
}
|
|
|
|
return name;
|
|
}
|
|
|
|
static const char *elf_sec_str(const struct bpf_object *obj, size_t off)
|
|
{
|
|
const char *name;
|
|
|
|
name = elf_strptr(obj->efile.elf, obj->efile.shstrndx, off);
|
|
if (!name) {
|
|
pr_warn("elf: failed to get section name string at offset %zu from %s: %s\n",
|
|
off, obj->path, elf_errmsg(-1));
|
|
return NULL;
|
|
}
|
|
|
|
return name;
|
|
}
|
|
|
|
static Elf_Scn *elf_sec_by_idx(const struct bpf_object *obj, size_t idx)
|
|
{
|
|
Elf_Scn *scn;
|
|
|
|
scn = elf_getscn(obj->efile.elf, idx);
|
|
if (!scn) {
|
|
pr_warn("elf: failed to get section(%zu) from %s: %s\n",
|
|
idx, obj->path, elf_errmsg(-1));
|
|
return NULL;
|
|
}
|
|
return scn;
|
|
}
|
|
|
|
static Elf_Scn *elf_sec_by_name(const struct bpf_object *obj, const char *name)
|
|
{
|
|
Elf_Scn *scn = NULL;
|
|
Elf *elf = obj->efile.elf;
|
|
const char *sec_name;
|
|
|
|
while ((scn = elf_nextscn(elf, scn)) != NULL) {
|
|
sec_name = elf_sec_name(obj, scn);
|
|
if (!sec_name)
|
|
return NULL;
|
|
|
|
if (strcmp(sec_name, name) != 0)
|
|
continue;
|
|
|
|
return scn;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static Elf64_Shdr *elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn)
|
|
{
|
|
Elf64_Shdr *shdr;
|
|
|
|
if (!scn)
|
|
return NULL;
|
|
|
|
shdr = elf64_getshdr(scn);
|
|
if (!shdr) {
|
|
pr_warn("elf: failed to get section(%zu) header from %s: %s\n",
|
|
elf_ndxscn(scn), obj->path, elf_errmsg(-1));
|
|
return NULL;
|
|
}
|
|
|
|
return shdr;
|
|
}
|
|
|
|
static const char *elf_sec_name(const struct bpf_object *obj, Elf_Scn *scn)
|
|
{
|
|
const char *name;
|
|
Elf64_Shdr *sh;
|
|
|
|
if (!scn)
|
|
return NULL;
|
|
|
|
sh = elf_sec_hdr(obj, scn);
|
|
if (!sh)
|
|
return NULL;
|
|
|
|
name = elf_sec_str(obj, sh->sh_name);
|
|
if (!name) {
|
|
pr_warn("elf: failed to get section(%zu) name from %s: %s\n",
|
|
elf_ndxscn(scn), obj->path, elf_errmsg(-1));
|
|
return NULL;
|
|
}
|
|
|
|
return name;
|
|
}
|
|
|
|
static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn)
|
|
{
|
|
Elf_Data *data;
|
|
|
|
if (!scn)
|
|
return NULL;
|
|
|
|
data = elf_getdata(scn, 0);
|
|
if (!data) {
|
|
pr_warn("elf: failed to get section(%zu) %s data from %s: %s\n",
|
|
elf_ndxscn(scn), elf_sec_name(obj, scn) ?: "<?>",
|
|
obj->path, elf_errmsg(-1));
|
|
return NULL;
|
|
}
|
|
|
|
return data;
|
|
}
|
|
|
|
static Elf64_Sym *elf_sym_by_idx(const struct bpf_object *obj, size_t idx)
|
|
{
|
|
if (idx >= obj->efile.symbols->d_size / sizeof(Elf64_Sym))
|
|
return NULL;
|
|
|
|
return (Elf64_Sym *)obj->efile.symbols->d_buf + idx;
|
|
}
|
|
|
|
static Elf64_Rel *elf_rel_by_idx(Elf_Data *data, size_t idx)
|
|
{
|
|
if (idx >= data->d_size / sizeof(Elf64_Rel))
|
|
return NULL;
|
|
|
|
return (Elf64_Rel *)data->d_buf + idx;
|
|
}
|
|
|
|
static bool is_sec_name_dwarf(const char *name)
|
|
{
|
|
/* approximation, but the actual list is too long */
|
|
return str_has_pfx(name, ".debug_");
|
|
}
|
|
|
|
static bool ignore_elf_section(Elf64_Shdr *hdr, const char *name)
|
|
{
|
|
/* no special handling of .strtab */
|
|
if (hdr->sh_type == SHT_STRTAB)
|
|
return true;
|
|
|
|
/* ignore .llvm_addrsig section as well */
|
|
if (hdr->sh_type == SHT_LLVM_ADDRSIG)
|
|
return true;
|
|
|
|
/* no subprograms will lead to an empty .text section, ignore it */
|
|
if (hdr->sh_type == SHT_PROGBITS && hdr->sh_size == 0 &&
|
|
strcmp(name, ".text") == 0)
|
|
return true;
|
|
|
|
/* DWARF sections */
|
|
if (is_sec_name_dwarf(name))
|
|
return true;
|
|
|
|
if (str_has_pfx(name, ".rel")) {
|
|
name += sizeof(".rel") - 1;
|
|
/* DWARF section relocations */
|
|
if (is_sec_name_dwarf(name))
|
|
return true;
|
|
|
|
/* .BTF and .BTF.ext don't need relocations */
|
|
if (strcmp(name, BTF_ELF_SEC) == 0 ||
|
|
strcmp(name, BTF_EXT_ELF_SEC) == 0)
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static int cmp_progs(const void *_a, const void *_b)
|
|
{
|
|
const struct bpf_program *a = _a;
|
|
const struct bpf_program *b = _b;
|
|
|
|
if (a->sec_idx != b->sec_idx)
|
|
return a->sec_idx < b->sec_idx ? -1 : 1;
|
|
|
|
/* sec_insn_off can't be the same within the section */
|
|
return a->sec_insn_off < b->sec_insn_off ? -1 : 1;
|
|
}
|
|
|
|
static int bpf_object__elf_collect(struct bpf_object *obj)
|
|
{
|
|
struct elf_sec_desc *sec_desc;
|
|
Elf *elf = obj->efile.elf;
|
|
Elf_Data *btf_ext_data = NULL;
|
|
Elf_Data *btf_data = NULL;
|
|
int idx = 0, err = 0;
|
|
const char *name;
|
|
Elf_Data *data;
|
|
Elf_Scn *scn;
|
|
Elf64_Shdr *sh;
|
|
|
|
/* ELF section indices are 0-based, but sec #0 is special "invalid"
|
|
* section. e_shnum does include sec #0, so e_shnum is the necessary
|
|
* size of an array to keep all the sections.
|
|
*/
|
|
obj->efile.sec_cnt = obj->efile.ehdr->e_shnum;
|
|
obj->efile.secs = calloc(obj->efile.sec_cnt, sizeof(*obj->efile.secs));
|
|
if (!obj->efile.secs)
|
|
return -ENOMEM;
|
|
|
|
/* a bunch of ELF parsing functionality depends on processing symbols,
|
|
* so do the first pass and find the symbol table
|
|
*/
|
|
scn = NULL;
|
|
while ((scn = elf_nextscn(elf, scn)) != NULL) {
|
|
sh = elf_sec_hdr(obj, scn);
|
|
if (!sh)
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
|
|
if (sh->sh_type == SHT_SYMTAB) {
|
|
if (obj->efile.symbols) {
|
|
pr_warn("elf: multiple symbol tables in %s\n", obj->path);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
data = elf_sec_data(obj, scn);
|
|
if (!data)
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
|
|
idx = elf_ndxscn(scn);
|
|
|
|
obj->efile.symbols = data;
|
|
obj->efile.symbols_shndx = idx;
|
|
obj->efile.strtabidx = sh->sh_link;
|
|
}
|
|
}
|
|
|
|
if (!obj->efile.symbols) {
|
|
pr_warn("elf: couldn't find symbol table in %s, stripped object file?\n",
|
|
obj->path);
|
|
return -ENOENT;
|
|
}
|
|
|
|
scn = NULL;
|
|
while ((scn = elf_nextscn(elf, scn)) != NULL) {
|
|
idx = elf_ndxscn(scn);
|
|
sec_desc = &obj->efile.secs[idx];
|
|
|
|
sh = elf_sec_hdr(obj, scn);
|
|
if (!sh)
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
|
|
name = elf_sec_str(obj, sh->sh_name);
|
|
if (!name)
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
|
|
if (ignore_elf_section(sh, name))
|
|
continue;
|
|
|
|
data = elf_sec_data(obj, scn);
|
|
if (!data)
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
|
|
pr_debug("elf: section(%d) %s, size %ld, link %d, flags %lx, type=%d\n",
|
|
idx, name, (unsigned long)data->d_size,
|
|
(int)sh->sh_link, (unsigned long)sh->sh_flags,
|
|
(int)sh->sh_type);
|
|
|
|
if (strcmp(name, "license") == 0) {
|
|
err = bpf_object__init_license(obj, data->d_buf, data->d_size);
|
|
if (err)
|
|
return err;
|
|
} else if (strcmp(name, "version") == 0) {
|
|
err = bpf_object__init_kversion(obj, data->d_buf, data->d_size);
|
|
if (err)
|
|
return err;
|
|
} else if (strcmp(name, "maps") == 0) {
|
|
obj->efile.maps_shndx = idx;
|
|
} else if (strcmp(name, MAPS_ELF_SEC) == 0) {
|
|
obj->efile.btf_maps_shndx = idx;
|
|
} else if (strcmp(name, BTF_ELF_SEC) == 0) {
|
|
if (sh->sh_type != SHT_PROGBITS)
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
btf_data = data;
|
|
} else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
|
|
if (sh->sh_type != SHT_PROGBITS)
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
btf_ext_data = data;
|
|
} else if (sh->sh_type == SHT_SYMTAB) {
|
|
/* already processed during the first pass above */
|
|
} else if (sh->sh_type == SHT_PROGBITS && data->d_size > 0) {
|
|
if (sh->sh_flags & SHF_EXECINSTR) {
|
|
if (strcmp(name, ".text") == 0)
|
|
obj->efile.text_shndx = idx;
|
|
err = bpf_object__add_programs(obj, data, name, idx);
|
|
if (err)
|
|
return err;
|
|
} else if (strcmp(name, DATA_SEC) == 0 ||
|
|
str_has_pfx(name, DATA_SEC ".")) {
|
|
sec_desc->sec_type = SEC_DATA;
|
|
sec_desc->shdr = sh;
|
|
sec_desc->data = data;
|
|
} else if (strcmp(name, RODATA_SEC) == 0 ||
|
|
str_has_pfx(name, RODATA_SEC ".")) {
|
|
sec_desc->sec_type = SEC_RODATA;
|
|
sec_desc->shdr = sh;
|
|
sec_desc->data = data;
|
|
} else if (strcmp(name, STRUCT_OPS_SEC) == 0) {
|
|
obj->efile.st_ops_data = data;
|
|
obj->efile.st_ops_shndx = idx;
|
|
} else {
|
|
pr_info("elf: skipping unrecognized data section(%d) %s\n",
|
|
idx, name);
|
|
}
|
|
} else if (sh->sh_type == SHT_REL) {
|
|
int targ_sec_idx = sh->sh_info; /* points to other section */
|
|
|
|
if (sh->sh_entsize != sizeof(Elf64_Rel) ||
|
|
targ_sec_idx >= obj->efile.sec_cnt)
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
|
|
/* Only do relo for section with exec instructions */
|
|
if (!section_have_execinstr(obj, targ_sec_idx) &&
|
|
strcmp(name, ".rel" STRUCT_OPS_SEC) &&
|
|
strcmp(name, ".rel" MAPS_ELF_SEC)) {
|
|
pr_info("elf: skipping relo section(%d) %s for section(%d) %s\n",
|
|
idx, name, targ_sec_idx,
|
|
elf_sec_name(obj, elf_sec_by_idx(obj, targ_sec_idx)) ?: "<?>");
|
|
continue;
|
|
}
|
|
|
|
sec_desc->sec_type = SEC_RELO;
|
|
sec_desc->shdr = sh;
|
|
sec_desc->data = data;
|
|
} else if (sh->sh_type == SHT_NOBITS && strcmp(name, BSS_SEC) == 0) {
|
|
sec_desc->sec_type = SEC_BSS;
|
|
sec_desc->shdr = sh;
|
|
sec_desc->data = data;
|
|
} else {
|
|
pr_info("elf: skipping section(%d) %s (size %zu)\n", idx, name,
|
|
(size_t)sh->sh_size);
|
|
}
|
|
}
|
|
|
|
if (!obj->efile.strtabidx || obj->efile.strtabidx > idx) {
|
|
pr_warn("elf: symbol strings section missing or invalid in %s\n", obj->path);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
/* sort BPF programs by section name and in-section instruction offset
|
|
* for faster search */
|
|
if (obj->nr_programs)
|
|
qsort(obj->programs, obj->nr_programs, sizeof(*obj->programs), cmp_progs);
|
|
|
|
return bpf_object__init_btf(obj, btf_data, btf_ext_data);
|
|
}
|
|
|
|
static bool sym_is_extern(const Elf64_Sym *sym)
|
|
{
|
|
int bind = ELF64_ST_BIND(sym->st_info);
|
|
/* externs are symbols w/ type=NOTYPE, bind=GLOBAL|WEAK, section=UND */
|
|
return sym->st_shndx == SHN_UNDEF &&
|
|
(bind == STB_GLOBAL || bind == STB_WEAK) &&
|
|
ELF64_ST_TYPE(sym->st_info) == STT_NOTYPE;
|
|
}
|
|
|
|
static bool sym_is_subprog(const Elf64_Sym *sym, int text_shndx)
|
|
{
|
|
int bind = ELF64_ST_BIND(sym->st_info);
|
|
int type = ELF64_ST_TYPE(sym->st_info);
|
|
|
|
/* in .text section */
|
|
if (sym->st_shndx != text_shndx)
|
|
return false;
|
|
|
|
/* local function */
|
|
if (bind == STB_LOCAL && type == STT_SECTION)
|
|
return true;
|
|
|
|
/* global function */
|
|
return bind == STB_GLOBAL && type == STT_FUNC;
|
|
}
|
|
|
|
static int find_extern_btf_id(const struct btf *btf, const char *ext_name)
|
|
{
|
|
const struct btf_type *t;
|
|
const char *tname;
|
|
int i, n;
|
|
|
|
if (!btf)
|
|
return -ESRCH;
|
|
|
|
n = btf__type_cnt(btf);
|
|
for (i = 1; i < n; i++) {
|
|
t = btf__type_by_id(btf, i);
|
|
|
|
if (!btf_is_var(t) && !btf_is_func(t))
|
|
continue;
|
|
|
|
tname = btf__name_by_offset(btf, t->name_off);
|
|
if (strcmp(tname, ext_name))
|
|
continue;
|
|
|
|
if (btf_is_var(t) &&
|
|
btf_var(t)->linkage != BTF_VAR_GLOBAL_EXTERN)
|
|
return -EINVAL;
|
|
|
|
if (btf_is_func(t) && btf_func_linkage(t) != BTF_FUNC_EXTERN)
|
|
return -EINVAL;
|
|
|
|
return i;
|
|
}
|
|
|
|
return -ENOENT;
|
|
}
|
|
|
|
static int find_extern_sec_btf_id(struct btf *btf, int ext_btf_id) {
|
|
const struct btf_var_secinfo *vs;
|
|
const struct btf_type *t;
|
|
int i, j, n;
|
|
|
|
if (!btf)
|
|
return -ESRCH;
|
|
|
|
n = btf__type_cnt(btf);
|
|
for (i = 1; i < n; i++) {
|
|
t = btf__type_by_id(btf, i);
|
|
|
|
if (!btf_is_datasec(t))
|
|
continue;
|
|
|
|
vs = btf_var_secinfos(t);
|
|
for (j = 0; j < btf_vlen(t); j++, vs++) {
|
|
if (vs->type == ext_btf_id)
|
|
return i;
|
|
}
|
|
}
|
|
|
|
return -ENOENT;
|
|
}
|
|
|
|
static enum kcfg_type find_kcfg_type(const struct btf *btf, int id,
|
|
bool *is_signed)
|
|
{
|
|
const struct btf_type *t;
|
|
const char *name;
|
|
|
|
t = skip_mods_and_typedefs(btf, id, NULL);
|
|
name = btf__name_by_offset(btf, t->name_off);
|
|
|
|
if (is_signed)
|
|
*is_signed = false;
|
|
switch (btf_kind(t)) {
|
|
case BTF_KIND_INT: {
|
|
int enc = btf_int_encoding(t);
|
|
|
|
if (enc & BTF_INT_BOOL)
|
|
return t->size == 1 ? KCFG_BOOL : KCFG_UNKNOWN;
|
|
if (is_signed)
|
|
*is_signed = enc & BTF_INT_SIGNED;
|
|
if (t->size == 1)
|
|
return KCFG_CHAR;
|
|
if (t->size < 1 || t->size > 8 || (t->size & (t->size - 1)))
|
|
return KCFG_UNKNOWN;
|
|
return KCFG_INT;
|
|
}
|
|
case BTF_KIND_ENUM:
|
|
if (t->size != 4)
|
|
return KCFG_UNKNOWN;
|
|
if (strcmp(name, "libbpf_tristate"))
|
|
return KCFG_UNKNOWN;
|
|
return KCFG_TRISTATE;
|
|
case BTF_KIND_ARRAY:
|
|
if (btf_array(t)->nelems == 0)
|
|
return KCFG_UNKNOWN;
|
|
if (find_kcfg_type(btf, btf_array(t)->type, NULL) != KCFG_CHAR)
|
|
return KCFG_UNKNOWN;
|
|
return KCFG_CHAR_ARR;
|
|
default:
|
|
return KCFG_UNKNOWN;
|
|
}
|
|
}
|
|
|
|
static int cmp_externs(const void *_a, const void *_b)
|
|
{
|
|
const struct extern_desc *a = _a;
|
|
const struct extern_desc *b = _b;
|
|
|
|
if (a->type != b->type)
|
|
return a->type < b->type ? -1 : 1;
|
|
|
|
if (a->type == EXT_KCFG) {
|
|
/* descending order by alignment requirements */
|
|
if (a->kcfg.align != b->kcfg.align)
|
|
return a->kcfg.align > b->kcfg.align ? -1 : 1;
|
|
/* ascending order by size, within same alignment class */
|
|
if (a->kcfg.sz != b->kcfg.sz)
|
|
return a->kcfg.sz < b->kcfg.sz ? -1 : 1;
|
|
}
|
|
|
|
/* resolve ties by name */
|
|
return strcmp(a->name, b->name);
|
|
}
|
|
|
|
static int find_int_btf_id(const struct btf *btf)
|
|
{
|
|
const struct btf_type *t;
|
|
int i, n;
|
|
|
|
n = btf__type_cnt(btf);
|
|
for (i = 1; i < n; i++) {
|
|
t = btf__type_by_id(btf, i);
|
|
|
|
if (btf_is_int(t) && btf_int_bits(t) == 32)
|
|
return i;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int add_dummy_ksym_var(struct btf *btf)
|
|
{
|
|
int i, int_btf_id, sec_btf_id, dummy_var_btf_id;
|
|
const struct btf_var_secinfo *vs;
|
|
const struct btf_type *sec;
|
|
|
|
if (!btf)
|
|
return 0;
|
|
|
|
sec_btf_id = btf__find_by_name_kind(btf, KSYMS_SEC,
|
|
BTF_KIND_DATASEC);
|
|
if (sec_btf_id < 0)
|
|
return 0;
|
|
|
|
sec = btf__type_by_id(btf, sec_btf_id);
|
|
vs = btf_var_secinfos(sec);
|
|
for (i = 0; i < btf_vlen(sec); i++, vs++) {
|
|
const struct btf_type *vt;
|
|
|
|
vt = btf__type_by_id(btf, vs->type);
|
|
if (btf_is_func(vt))
|
|
break;
|
|
}
|
|
|
|
/* No func in ksyms sec. No need to add dummy var. */
|
|
if (i == btf_vlen(sec))
|
|
return 0;
|
|
|
|
int_btf_id = find_int_btf_id(btf);
|
|
dummy_var_btf_id = btf__add_var(btf,
|
|
"dummy_ksym",
|
|
BTF_VAR_GLOBAL_ALLOCATED,
|
|
int_btf_id);
|
|
if (dummy_var_btf_id < 0)
|
|
pr_warn("cannot create a dummy_ksym var\n");
|
|
|
|
return dummy_var_btf_id;
|
|
}
|
|
|
|
static int bpf_object__collect_externs(struct bpf_object *obj)
|
|
{
|
|
struct btf_type *sec, *kcfg_sec = NULL, *ksym_sec = NULL;
|
|
const struct btf_type *t;
|
|
struct extern_desc *ext;
|
|
int i, n, off, dummy_var_btf_id;
|
|
const char *ext_name, *sec_name;
|
|
Elf_Scn *scn;
|
|
Elf64_Shdr *sh;
|
|
|
|
if (!obj->efile.symbols)
|
|
return 0;
|
|
|
|
scn = elf_sec_by_idx(obj, obj->efile.symbols_shndx);
|
|
sh = elf_sec_hdr(obj, scn);
|
|
if (!sh || sh->sh_entsize != sizeof(Elf64_Sym))
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
|
|
dummy_var_btf_id = add_dummy_ksym_var(obj->btf);
|
|
if (dummy_var_btf_id < 0)
|
|
return dummy_var_btf_id;
|
|
|
|
n = sh->sh_size / sh->sh_entsize;
|
|
pr_debug("looking for externs among %d symbols...\n", n);
|
|
|
|
for (i = 0; i < n; i++) {
|
|
Elf64_Sym *sym = elf_sym_by_idx(obj, i);
|
|
|
|
if (!sym)
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
if (!sym_is_extern(sym))
|
|
continue;
|
|
ext_name = elf_sym_str(obj, sym->st_name);
|
|
if (!ext_name || !ext_name[0])
|
|
continue;
|
|
|
|
ext = obj->externs;
|
|
ext = libbpf_reallocarray(ext, obj->nr_extern + 1, sizeof(*ext));
|
|
if (!ext)
|
|
return -ENOMEM;
|
|
obj->externs = ext;
|
|
ext = &ext[obj->nr_extern];
|
|
memset(ext, 0, sizeof(*ext));
|
|
obj->nr_extern++;
|
|
|
|
ext->btf_id = find_extern_btf_id(obj->btf, ext_name);
|
|
if (ext->btf_id <= 0) {
|
|
pr_warn("failed to find BTF for extern '%s': %d\n",
|
|
ext_name, ext->btf_id);
|
|
return ext->btf_id;
|
|
}
|
|
t = btf__type_by_id(obj->btf, ext->btf_id);
|
|
ext->name = btf__name_by_offset(obj->btf, t->name_off);
|
|
ext->sym_idx = i;
|
|
ext->is_weak = ELF64_ST_BIND(sym->st_info) == STB_WEAK;
|
|
|
|
ext->sec_btf_id = find_extern_sec_btf_id(obj->btf, ext->btf_id);
|
|
if (ext->sec_btf_id <= 0) {
|
|
pr_warn("failed to find BTF for extern '%s' [%d] section: %d\n",
|
|
ext_name, ext->btf_id, ext->sec_btf_id);
|
|
return ext->sec_btf_id;
|
|
}
|
|
sec = (void *)btf__type_by_id(obj->btf, ext->sec_btf_id);
|
|
sec_name = btf__name_by_offset(obj->btf, sec->name_off);
|
|
|
|
if (strcmp(sec_name, KCONFIG_SEC) == 0) {
|
|
if (btf_is_func(t)) {
|
|
pr_warn("extern function %s is unsupported under %s section\n",
|
|
ext->name, KCONFIG_SEC);
|
|
return -ENOTSUP;
|
|
}
|
|
kcfg_sec = sec;
|
|
ext->type = EXT_KCFG;
|
|
ext->kcfg.sz = btf__resolve_size(obj->btf, t->type);
|
|
if (ext->kcfg.sz <= 0) {
|
|
pr_warn("failed to resolve size of extern (kcfg) '%s': %d\n",
|
|
ext_name, ext->kcfg.sz);
|
|
return ext->kcfg.sz;
|
|
}
|
|
ext->kcfg.align = btf__align_of(obj->btf, t->type);
|
|
if (ext->kcfg.align <= 0) {
|
|
pr_warn("failed to determine alignment of extern (kcfg) '%s': %d\n",
|
|
ext_name, ext->kcfg.align);
|
|
return -EINVAL;
|
|
}
|
|
ext->kcfg.type = find_kcfg_type(obj->btf, t->type,
|
|
&ext->kcfg.is_signed);
|
|
if (ext->kcfg.type == KCFG_UNKNOWN) {
|
|
pr_warn("extern (kcfg) '%s' type is unsupported\n", ext_name);
|
|
return -ENOTSUP;
|
|
}
|
|
} else if (strcmp(sec_name, KSYMS_SEC) == 0) {
|
|
ksym_sec = sec;
|
|
ext->type = EXT_KSYM;
|
|
skip_mods_and_typedefs(obj->btf, t->type,
|
|
&ext->ksym.type_id);
|
|
} else {
|
|
pr_warn("unrecognized extern section '%s'\n", sec_name);
|
|
return -ENOTSUP;
|
|
}
|
|
}
|
|
pr_debug("collected %d externs total\n", obj->nr_extern);
|
|
|
|
if (!obj->nr_extern)
|
|
return 0;
|
|
|
|
/* sort externs by type, for kcfg ones also by (align, size, name) */
|
|
qsort(obj->externs, obj->nr_extern, sizeof(*ext), cmp_externs);
|
|
|
|
/* for .ksyms section, we need to turn all externs into allocated
|
|
* variables in BTF to pass kernel verification; we do this by
|
|
* pretending that each extern is a 8-byte variable
|
|
*/
|
|
if (ksym_sec) {
|
|
/* find existing 4-byte integer type in BTF to use for fake
|
|
* extern variables in DATASEC
|
|
*/
|
|
int int_btf_id = find_int_btf_id(obj->btf);
|
|
/* For extern function, a dummy_var added earlier
|
|
* will be used to replace the vs->type and
|
|
* its name string will be used to refill
|
|
* the missing param's name.
|
|
*/
|
|
const struct btf_type *dummy_var;
|
|
|
|
dummy_var = btf__type_by_id(obj->btf, dummy_var_btf_id);
|
|
for (i = 0; i < obj->nr_extern; i++) {
|
|
ext = &obj->externs[i];
|
|
if (ext->type != EXT_KSYM)
|
|
continue;
|
|
pr_debug("extern (ksym) #%d: symbol %d, name %s\n",
|
|
i, ext->sym_idx, ext->name);
|
|
}
|
|
|
|
sec = ksym_sec;
|
|
n = btf_vlen(sec);
|
|
for (i = 0, off = 0; i < n; i++, off += sizeof(int)) {
|
|
struct btf_var_secinfo *vs = btf_var_secinfos(sec) + i;
|
|
struct btf_type *vt;
|
|
|
|
vt = (void *)btf__type_by_id(obj->btf, vs->type);
|
|
ext_name = btf__name_by_offset(obj->btf, vt->name_off);
|
|
ext = find_extern_by_name(obj, ext_name);
|
|
if (!ext) {
|
|
pr_warn("failed to find extern definition for BTF %s '%s'\n",
|
|
btf_kind_str(vt), ext_name);
|
|
return -ESRCH;
|
|
}
|
|
if (btf_is_func(vt)) {
|
|
const struct btf_type *func_proto;
|
|
struct btf_param *param;
|
|
int j;
|
|
|
|
func_proto = btf__type_by_id(obj->btf,
|
|
vt->type);
|
|
param = btf_params(func_proto);
|
|
/* Reuse the dummy_var string if the
|
|
* func proto does not have param name.
|
|
*/
|
|
for (j = 0; j < btf_vlen(func_proto); j++)
|
|
if (param[j].type && !param[j].name_off)
|
|
param[j].name_off =
|
|
dummy_var->name_off;
|
|
vs->type = dummy_var_btf_id;
|
|
vt->info &= ~0xffff;
|
|
vt->info |= BTF_FUNC_GLOBAL;
|
|
} else {
|
|
btf_var(vt)->linkage = BTF_VAR_GLOBAL_ALLOCATED;
|
|
vt->type = int_btf_id;
|
|
}
|
|
vs->offset = off;
|
|
vs->size = sizeof(int);
|
|
}
|
|
sec->size = off;
|
|
}
|
|
|
|
if (kcfg_sec) {
|
|
sec = kcfg_sec;
|
|
/* for kcfg externs calculate their offsets within a .kconfig map */
|
|
off = 0;
|
|
for (i = 0; i < obj->nr_extern; i++) {
|
|
ext = &obj->externs[i];
|
|
if (ext->type != EXT_KCFG)
|
|
continue;
|
|
|
|
ext->kcfg.data_off = roundup(off, ext->kcfg.align);
|
|
off = ext->kcfg.data_off + ext->kcfg.sz;
|
|
pr_debug("extern (kcfg) #%d: symbol %d, off %u, name %s\n",
|
|
i, ext->sym_idx, ext->kcfg.data_off, ext->name);
|
|
}
|
|
sec->size = off;
|
|
n = btf_vlen(sec);
|
|
for (i = 0; i < n; i++) {
|
|
struct btf_var_secinfo *vs = btf_var_secinfos(sec) + i;
|
|
|
|
t = btf__type_by_id(obj->btf, vs->type);
|
|
ext_name = btf__name_by_offset(obj->btf, t->name_off);
|
|
ext = find_extern_by_name(obj, ext_name);
|
|
if (!ext) {
|
|
pr_warn("failed to find extern definition for BTF var '%s'\n",
|
|
ext_name);
|
|
return -ESRCH;
|
|
}
|
|
btf_var(t)->linkage = BTF_VAR_GLOBAL_ALLOCATED;
|
|
vs->offset = ext->kcfg.data_off;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
struct bpf_program *
|
|
bpf_object__find_program_by_title(const struct bpf_object *obj,
|
|
const char *title)
|
|
{
|
|
struct bpf_program *pos;
|
|
|
|
bpf_object__for_each_program(pos, obj) {
|
|
if (pos->sec_name && !strcmp(pos->sec_name, title))
|
|
return pos;
|
|
}
|
|
return errno = ENOENT, NULL;
|
|
}
|
|
|
|
static bool prog_is_subprog(const struct bpf_object *obj,
|
|
const struct bpf_program *prog)
|
|
{
|
|
/* For legacy reasons, libbpf supports an entry-point BPF programs
|
|
* without SEC() attribute, i.e., those in the .text section. But if
|
|
* there are 2 or more such programs in the .text section, they all
|
|
* must be subprograms called from entry-point BPF programs in
|
|
* designated SEC()'tions, otherwise there is no way to distinguish
|
|
* which of those programs should be loaded vs which are a subprogram.
|
|
* Similarly, if there is a function/program in .text and at least one
|
|
* other BPF program with custom SEC() attribute, then we just assume
|
|
* .text programs are subprograms (even if they are not called from
|
|
* other programs), because libbpf never explicitly supported mixing
|
|
* SEC()-designated BPF programs and .text entry-point BPF programs.
|
|
*
|
|
* In libbpf 1.0 strict mode, we always consider .text
|
|
* programs to be subprograms.
|
|
*/
|
|
|
|
if (libbpf_mode & LIBBPF_STRICT_SEC_NAME)
|
|
return prog->sec_idx == obj->efile.text_shndx;
|
|
|
|
return prog->sec_idx == obj->efile.text_shndx && obj->nr_programs > 1;
|
|
}
|
|
|
|
struct bpf_program *
|
|
bpf_object__find_program_by_name(const struct bpf_object *obj,
|
|
const char *name)
|
|
{
|
|
struct bpf_program *prog;
|
|
|
|
bpf_object__for_each_program(prog, obj) {
|
|
if (prog_is_subprog(obj, prog))
|
|
continue;
|
|
if (!strcmp(prog->name, name))
|
|
return prog;
|
|
}
|
|
return errno = ENOENT, NULL;
|
|
}
|
|
|
|
static bool bpf_object__shndx_is_data(const struct bpf_object *obj,
|
|
int shndx)
|
|
{
|
|
switch (obj->efile.secs[shndx].sec_type) {
|
|
case SEC_BSS:
|
|
case SEC_DATA:
|
|
case SEC_RODATA:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
static bool bpf_object__shndx_is_maps(const struct bpf_object *obj,
|
|
int shndx)
|
|
{
|
|
return shndx == obj->efile.maps_shndx ||
|
|
shndx == obj->efile.btf_maps_shndx;
|
|
}
|
|
|
|
static enum libbpf_map_type
|
|
bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx)
|
|
{
|
|
if (shndx == obj->efile.symbols_shndx)
|
|
return LIBBPF_MAP_KCONFIG;
|
|
|
|
switch (obj->efile.secs[shndx].sec_type) {
|
|
case SEC_BSS:
|
|
return LIBBPF_MAP_BSS;
|
|
case SEC_DATA:
|
|
return LIBBPF_MAP_DATA;
|
|
case SEC_RODATA:
|
|
return LIBBPF_MAP_RODATA;
|
|
default:
|
|
return LIBBPF_MAP_UNSPEC;
|
|
}
|
|
}
|
|
|
|
static int bpf_program__record_reloc(struct bpf_program *prog,
|
|
struct reloc_desc *reloc_desc,
|
|
__u32 insn_idx, const char *sym_name,
|
|
const Elf64_Sym *sym, const Elf64_Rel *rel)
|
|
{
|
|
struct bpf_insn *insn = &prog->insns[insn_idx];
|
|
size_t map_idx, nr_maps = prog->obj->nr_maps;
|
|
struct bpf_object *obj = prog->obj;
|
|
__u32 shdr_idx = sym->st_shndx;
|
|
enum libbpf_map_type type;
|
|
const char *sym_sec_name;
|
|
struct bpf_map *map;
|
|
|
|
if (!is_call_insn(insn) && !is_ldimm64_insn(insn)) {
|
|
pr_warn("prog '%s': invalid relo against '%s' for insns[%d].code 0x%x\n",
|
|
prog->name, sym_name, insn_idx, insn->code);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
|
|
if (sym_is_extern(sym)) {
|
|
int sym_idx = ELF64_R_SYM(rel->r_info);
|
|
int i, n = obj->nr_extern;
|
|
struct extern_desc *ext;
|
|
|
|
for (i = 0; i < n; i++) {
|
|
ext = &obj->externs[i];
|
|
if (ext->sym_idx == sym_idx)
|
|
break;
|
|
}
|
|
if (i >= n) {
|
|
pr_warn("prog '%s': extern relo failed to find extern for '%s' (%d)\n",
|
|
prog->name, sym_name, sym_idx);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
pr_debug("prog '%s': found extern #%d '%s' (sym %d) for insn #%u\n",
|
|
prog->name, i, ext->name, ext->sym_idx, insn_idx);
|
|
if (insn->code == (BPF_JMP | BPF_CALL))
|
|
reloc_desc->type = RELO_EXTERN_FUNC;
|
|
else
|
|
reloc_desc->type = RELO_EXTERN_VAR;
|
|
reloc_desc->insn_idx = insn_idx;
|
|
reloc_desc->sym_off = i; /* sym_off stores extern index */
|
|
return 0;
|
|
}
|
|
|
|
/* sub-program call relocation */
|
|
if (is_call_insn(insn)) {
|
|
if (insn->src_reg != BPF_PSEUDO_CALL) {
|
|
pr_warn("prog '%s': incorrect bpf_call opcode\n", prog->name);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
/* text_shndx can be 0, if no default "main" program exists */
|
|
if (!shdr_idx || shdr_idx != obj->efile.text_shndx) {
|
|
sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, shdr_idx));
|
|
pr_warn("prog '%s': bad call relo against '%s' in section '%s'\n",
|
|
prog->name, sym_name, sym_sec_name);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
if (sym->st_value % BPF_INSN_SZ) {
|
|
pr_warn("prog '%s': bad call relo against '%s' at offset %zu\n",
|
|
prog->name, sym_name, (size_t)sym->st_value);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
reloc_desc->type = RELO_CALL;
|
|
reloc_desc->insn_idx = insn_idx;
|
|
reloc_desc->sym_off = sym->st_value;
|
|
return 0;
|
|
}
|
|
|
|
if (!shdr_idx || shdr_idx >= SHN_LORESERVE) {
|
|
pr_warn("prog '%s': invalid relo against '%s' in special section 0x%x; forgot to initialize global var?..\n",
|
|
prog->name, sym_name, shdr_idx);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
|
|
/* loading subprog addresses */
|
|
if (sym_is_subprog(sym, obj->efile.text_shndx)) {
|
|
/* global_func: sym->st_value = offset in the section, insn->imm = 0.
|
|
* local_func: sym->st_value = 0, insn->imm = offset in the section.
|
|
*/
|
|
if ((sym->st_value % BPF_INSN_SZ) || (insn->imm % BPF_INSN_SZ)) {
|
|
pr_warn("prog '%s': bad subprog addr relo against '%s' at offset %zu+%d\n",
|
|
prog->name, sym_name, (size_t)sym->st_value, insn->imm);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
|
|
reloc_desc->type = RELO_SUBPROG_ADDR;
|
|
reloc_desc->insn_idx = insn_idx;
|
|
reloc_desc->sym_off = sym->st_value;
|
|
return 0;
|
|
}
|
|
|
|
type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx);
|
|
sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, shdr_idx));
|
|
|
|
/* generic map reference relocation */
|
|
if (type == LIBBPF_MAP_UNSPEC) {
|
|
if (!bpf_object__shndx_is_maps(obj, shdr_idx)) {
|
|
pr_warn("prog '%s': bad map relo against '%s' in section '%s'\n",
|
|
prog->name, sym_name, sym_sec_name);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
for (map_idx = 0; map_idx < nr_maps; map_idx++) {
|
|
map = &obj->maps[map_idx];
|
|
if (map->libbpf_type != type ||
|
|
map->sec_idx != sym->st_shndx ||
|
|
map->sec_offset != sym->st_value)
|
|
continue;
|
|
pr_debug("prog '%s': found map %zd (%s, sec %d, off %zu) for insn #%u\n",
|
|
prog->name, map_idx, map->name, map->sec_idx,
|
|
map->sec_offset, insn_idx);
|
|
break;
|
|
}
|
|
if (map_idx >= nr_maps) {
|
|
pr_warn("prog '%s': map relo failed to find map for section '%s', off %zu\n",
|
|
prog->name, sym_sec_name, (size_t)sym->st_value);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
reloc_desc->type = RELO_LD64;
|
|
reloc_desc->insn_idx = insn_idx;
|
|
reloc_desc->map_idx = map_idx;
|
|
reloc_desc->sym_off = 0; /* sym->st_value determines map_idx */
|
|
return 0;
|
|
}
|
|
|
|
/* global data map relocation */
|
|
if (!bpf_object__shndx_is_data(obj, shdr_idx)) {
|
|
pr_warn("prog '%s': bad data relo against section '%s'\n",
|
|
prog->name, sym_sec_name);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
for (map_idx = 0; map_idx < nr_maps; map_idx++) {
|
|
map = &obj->maps[map_idx];
|
|
if (map->libbpf_type != type || map->sec_idx != sym->st_shndx)
|
|
continue;
|
|
pr_debug("prog '%s': found data map %zd (%s, sec %d, off %zu) for insn %u\n",
|
|
prog->name, map_idx, map->name, map->sec_idx,
|
|
map->sec_offset, insn_idx);
|
|
break;
|
|
}
|
|
if (map_idx >= nr_maps) {
|
|
pr_warn("prog '%s': data relo failed to find map for section '%s'\n",
|
|
prog->name, sym_sec_name);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
|
|
reloc_desc->type = RELO_DATA;
|
|
reloc_desc->insn_idx = insn_idx;
|
|
reloc_desc->map_idx = map_idx;
|
|
reloc_desc->sym_off = sym->st_value;
|
|
return 0;
|
|
}
|
|
|
|
static bool prog_contains_insn(const struct bpf_program *prog, size_t insn_idx)
|
|
{
|
|
return insn_idx >= prog->sec_insn_off &&
|
|
insn_idx < prog->sec_insn_off + prog->sec_insn_cnt;
|
|
}
|
|
|
|
static struct bpf_program *find_prog_by_sec_insn(const struct bpf_object *obj,
|
|
size_t sec_idx, size_t insn_idx)
|
|
{
|
|
int l = 0, r = obj->nr_programs - 1, m;
|
|
struct bpf_program *prog;
|
|
|
|
while (l < r) {
|
|
m = l + (r - l + 1) / 2;
|
|
prog = &obj->programs[m];
|
|
|
|
if (prog->sec_idx < sec_idx ||
|
|
(prog->sec_idx == sec_idx && prog->sec_insn_off <= insn_idx))
|
|
l = m;
|
|
else
|
|
r = m - 1;
|
|
}
|
|
/* matching program could be at index l, but it still might be the
|
|
* wrong one, so we need to double check conditions for the last time
|
|
*/
|
|
prog = &obj->programs[l];
|
|
if (prog->sec_idx == sec_idx && prog_contains_insn(prog, insn_idx))
|
|
return prog;
|
|
return NULL;
|
|
}
|
|
|
|
static int
|
|
bpf_object__collect_prog_relos(struct bpf_object *obj, Elf64_Shdr *shdr, Elf_Data *data)
|
|
{
|
|
const char *relo_sec_name, *sec_name;
|
|
size_t sec_idx = shdr->sh_info, sym_idx;
|
|
struct bpf_program *prog;
|
|
struct reloc_desc *relos;
|
|
int err, i, nrels;
|
|
const char *sym_name;
|
|
__u32 insn_idx;
|
|
Elf_Scn *scn;
|
|
Elf_Data *scn_data;
|
|
Elf64_Sym *sym;
|
|
Elf64_Rel *rel;
|
|
|
|
if (sec_idx >= obj->efile.sec_cnt)
|
|
return -EINVAL;
|
|
|
|
scn = elf_sec_by_idx(obj, sec_idx);
|
|
scn_data = elf_sec_data(obj, scn);
|
|
|
|
relo_sec_name = elf_sec_str(obj, shdr->sh_name);
|
|
sec_name = elf_sec_name(obj, scn);
|
|
if (!relo_sec_name || !sec_name)
|
|
return -EINVAL;
|
|
|
|
pr_debug("sec '%s': collecting relocation for section(%zu) '%s'\n",
|
|
relo_sec_name, sec_idx, sec_name);
|
|
nrels = shdr->sh_size / shdr->sh_entsize;
|
|
|
|
for (i = 0; i < nrels; i++) {
|
|
rel = elf_rel_by_idx(data, i);
|
|
if (!rel) {
|
|
pr_warn("sec '%s': failed to get relo #%d\n", relo_sec_name, i);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
sym_idx = ELF64_R_SYM(rel->r_info);
|
|
sym = elf_sym_by_idx(obj, sym_idx);
|
|
if (!sym) {
|
|
pr_warn("sec '%s': symbol #%zu not found for relo #%d\n",
|
|
relo_sec_name, sym_idx, i);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
if (sym->st_shndx >= obj->efile.sec_cnt) {
|
|
pr_warn("sec '%s': corrupted symbol #%zu pointing to invalid section #%zu for relo #%d\n",
|
|
relo_sec_name, sym_idx, (size_t)sym->st_shndx, i);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
if (rel->r_offset % BPF_INSN_SZ || rel->r_offset >= scn_data->d_size) {
|
|
pr_warn("sec '%s': invalid offset 0x%zx for relo #%d\n",
|
|
relo_sec_name, (size_t)rel->r_offset, i);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
insn_idx = rel->r_offset / BPF_INSN_SZ;
|
|
/* relocations against static functions are recorded as
|
|
* relocations against the section that contains a function;
|
|
* in such case, symbol will be STT_SECTION and sym.st_name
|
|
* will point to empty string (0), so fetch section name
|
|
* instead
|
|
*/
|
|
if (ELF64_ST_TYPE(sym->st_info) == STT_SECTION && sym->st_name == 0)
|
|
sym_name = elf_sec_name(obj, elf_sec_by_idx(obj, sym->st_shndx));
|
|
else
|
|
sym_name = elf_sym_str(obj, sym->st_name);
|
|
sym_name = sym_name ?: "<?";
|
|
|
|
pr_debug("sec '%s': relo #%d: insn #%u against '%s'\n",
|
|
relo_sec_name, i, insn_idx, sym_name);
|
|
|
|
prog = find_prog_by_sec_insn(obj, sec_idx, insn_idx);
|
|
if (!prog) {
|
|
pr_debug("sec '%s': relo #%d: couldn't find program in section '%s' for insn #%u, probably overridden weak function, skipping...\n",
|
|
relo_sec_name, i, sec_name, insn_idx);
|
|
continue;
|
|
}
|
|
|
|
relos = libbpf_reallocarray(prog->reloc_desc,
|
|
prog->nr_reloc + 1, sizeof(*relos));
|
|
if (!relos)
|
|
return -ENOMEM;
|
|
prog->reloc_desc = relos;
|
|
|
|
/* adjust insn_idx to local BPF program frame of reference */
|
|
insn_idx -= prog->sec_insn_off;
|
|
err = bpf_program__record_reloc(prog, &relos[prog->nr_reloc],
|
|
insn_idx, sym_name, sym, rel);
|
|
if (err)
|
|
return err;
|
|
|
|
prog->nr_reloc++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map)
|
|
{
|
|
struct bpf_map_def *def = &map->def;
|
|
__u32 key_type_id = 0, value_type_id = 0;
|
|
int ret;
|
|
|
|
if (!obj->btf)
|
|
return -ENOENT;
|
|
|
|
/* if it's BTF-defined map, we don't need to search for type IDs.
|
|
* For struct_ops map, it does not need btf_key_type_id and
|
|
* btf_value_type_id.
|
|
*/
|
|
if (map->sec_idx == obj->efile.btf_maps_shndx ||
|
|
bpf_map__is_struct_ops(map))
|
|
return 0;
|
|
|
|
if (!bpf_map__is_internal(map)) {
|
|
pr_warn("Use of BPF_ANNOTATE_KV_PAIR is deprecated, use BTF-defined maps in .maps section instead\n");
|
|
#pragma GCC diagnostic push
|
|
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
|
|
ret = btf__get_map_kv_tids(obj->btf, map->name, def->key_size,
|
|
def->value_size, &key_type_id,
|
|
&value_type_id);
|
|
#pragma GCC diagnostic pop
|
|
} else {
|
|
/*
|
|
* LLVM annotates global data differently in BTF, that is,
|
|
* only as '.data', '.bss' or '.rodata'.
|
|
*/
|
|
ret = btf__find_by_name(obj->btf, map->real_name);
|
|
}
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
map->btf_key_type_id = key_type_id;
|
|
map->btf_value_type_id = bpf_map__is_internal(map) ?
|
|
ret : value_type_id;
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_get_map_info_from_fdinfo(int fd, struct bpf_map_info *info)
|
|
{
|
|
char file[PATH_MAX], buff[4096];
|
|
FILE *fp;
|
|
__u32 val;
|
|
int err;
|
|
|
|
snprintf(file, sizeof(file), "/proc/%d/fdinfo/%d", getpid(), fd);
|
|
memset(info, 0, sizeof(*info));
|
|
|
|
fp = fopen(file, "r");
|
|
if (!fp) {
|
|
err = -errno;
|
|
pr_warn("failed to open %s: %d. No procfs support?\n", file,
|
|
err);
|
|
return err;
|
|
}
|
|
|
|
while (fgets(buff, sizeof(buff), fp)) {
|
|
if (sscanf(buff, "map_type:\t%u", &val) == 1)
|
|
info->type = val;
|
|
else if (sscanf(buff, "key_size:\t%u", &val) == 1)
|
|
info->key_size = val;
|
|
else if (sscanf(buff, "value_size:\t%u", &val) == 1)
|
|
info->value_size = val;
|
|
else if (sscanf(buff, "max_entries:\t%u", &val) == 1)
|
|
info->max_entries = val;
|
|
else if (sscanf(buff, "map_flags:\t%i", &val) == 1)
|
|
info->map_flags = val;
|
|
}
|
|
|
|
fclose(fp);
|
|
|
|
return 0;
|
|
}
|
|
|
|
bool bpf_map__autocreate(const struct bpf_map *map)
|
|
{
|
|
return map->autocreate;
|
|
}
|
|
|
|
int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate)
|
|
{
|
|
if (map->obj->loaded)
|
|
return libbpf_err(-EBUSY);
|
|
|
|
map->autocreate = autocreate;
|
|
return 0;
|
|
}
|
|
|
|
int bpf_map__reuse_fd(struct bpf_map *map, int fd)
|
|
{
|
|
struct bpf_map_info info = {};
|
|
__u32 len = sizeof(info);
|
|
int new_fd, err;
|
|
char *new_name;
|
|
|
|
err = bpf_obj_get_info_by_fd(fd, &info, &len);
|
|
if (err && errno == EINVAL)
|
|
err = bpf_get_map_info_from_fdinfo(fd, &info);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
new_name = strdup(info.name);
|
|
if (!new_name)
|
|
return libbpf_err(-errno);
|
|
|
|
new_fd = open("/", O_RDONLY | O_CLOEXEC);
|
|
if (new_fd < 0) {
|
|
err = -errno;
|
|
goto err_free_new_name;
|
|
}
|
|
|
|
new_fd = dup3(fd, new_fd, O_CLOEXEC);
|
|
if (new_fd < 0) {
|
|
err = -errno;
|
|
goto err_close_new_fd;
|
|
}
|
|
|
|
err = zclose(map->fd);
|
|
if (err) {
|
|
err = -errno;
|
|
goto err_close_new_fd;
|
|
}
|
|
free(map->name);
|
|
|
|
map->fd = new_fd;
|
|
map->name = new_name;
|
|
map->def.type = info.type;
|
|
map->def.key_size = info.key_size;
|
|
map->def.value_size = info.value_size;
|
|
map->def.max_entries = info.max_entries;
|
|
map->def.map_flags = info.map_flags;
|
|
map->btf_key_type_id = info.btf_key_type_id;
|
|
map->btf_value_type_id = info.btf_value_type_id;
|
|
map->reused = true;
|
|
map->map_extra = info.map_extra;
|
|
|
|
return 0;
|
|
|
|
err_close_new_fd:
|
|
close(new_fd);
|
|
err_free_new_name:
|
|
free(new_name);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
__u32 bpf_map__max_entries(const struct bpf_map *map)
|
|
{
|
|
return map->def.max_entries;
|
|
}
|
|
|
|
struct bpf_map *bpf_map__inner_map(struct bpf_map *map)
|
|
{
|
|
if (!bpf_map_type__is_map_in_map(map->def.type))
|
|
return errno = EINVAL, NULL;
|
|
|
|
return map->inner_map;
|
|
}
|
|
|
|
int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries)
|
|
{
|
|
if (map->fd >= 0)
|
|
return libbpf_err(-EBUSY);
|
|
map->def.max_entries = max_entries;
|
|
return 0;
|
|
}
|
|
|
|
int bpf_map__resize(struct bpf_map *map, __u32 max_entries)
|
|
{
|
|
if (!map || !max_entries)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
return bpf_map__set_max_entries(map, max_entries);
|
|
}
|
|
|
|
static int
|
|
bpf_object__probe_loading(struct bpf_object *obj)
|
|
{
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
struct bpf_insn insns[] = {
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
BPF_EXIT_INSN(),
|
|
};
|
|
int ret, insn_cnt = ARRAY_SIZE(insns);
|
|
|
|
if (obj->gen_loader)
|
|
return 0;
|
|
|
|
ret = bump_rlimit_memlock();
|
|
if (ret)
|
|
pr_warn("Failed to bump RLIMIT_MEMLOCK (err = %d), you might need to do it explicitly!\n", ret);
|
|
|
|
/* make sure basic loading works */
|
|
ret = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", insns, insn_cnt, NULL);
|
|
if (ret < 0)
|
|
ret = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL", insns, insn_cnt, NULL);
|
|
if (ret < 0) {
|
|
ret = errno;
|
|
cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
|
|
pr_warn("Error in %s():%s(%d). Couldn't load trivial BPF "
|
|
"program. Make sure your kernel supports BPF "
|
|
"(CONFIG_BPF_SYSCALL=y) and/or that RLIMIT_MEMLOCK is "
|
|
"set to big enough value.\n", __func__, cp, ret);
|
|
return -ret;
|
|
}
|
|
close(ret);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int probe_fd(int fd)
|
|
{
|
|
if (fd >= 0)
|
|
close(fd);
|
|
return fd >= 0;
|
|
}
|
|
|
|
static int probe_kern_prog_name(void)
|
|
{
|
|
struct bpf_insn insns[] = {
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
BPF_EXIT_INSN(),
|
|
};
|
|
int ret, insn_cnt = ARRAY_SIZE(insns);
|
|
|
|
/* make sure loading with name works */
|
|
ret = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, "test", "GPL", insns, insn_cnt, NULL);
|
|
return probe_fd(ret);
|
|
}
|
|
|
|
static int probe_kern_global_data(void)
|
|
{
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
struct bpf_insn insns[] = {
|
|
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 16),
|
|
BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 42),
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
BPF_EXIT_INSN(),
|
|
};
|
|
int ret, map, insn_cnt = ARRAY_SIZE(insns);
|
|
|
|
map = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, sizeof(int), 32, 1, NULL);
|
|
if (map < 0) {
|
|
ret = -errno;
|
|
cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
|
|
pr_warn("Error in %s():%s(%d). Couldn't create simple array map.\n",
|
|
__func__, cp, -ret);
|
|
return ret;
|
|
}
|
|
|
|
insns[0].imm = map;
|
|
|
|
ret = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", insns, insn_cnt, NULL);
|
|
close(map);
|
|
return probe_fd(ret);
|
|
}
|
|
|
|
static int probe_kern_btf(void)
|
|
{
|
|
static const char strs[] = "\0int";
|
|
__u32 types[] = {
|
|
/* int */
|
|
BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4),
|
|
};
|
|
|
|
return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
|
|
strs, sizeof(strs)));
|
|
}
|
|
|
|
static int probe_kern_btf_func(void)
|
|
{
|
|
static const char strs[] = "\0int\0x\0a";
|
|
/* void x(int a) {} */
|
|
__u32 types[] = {
|
|
/* int */
|
|
BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
|
|
/* FUNC_PROTO */ /* [2] */
|
|
BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 1), 0),
|
|
BTF_PARAM_ENC(7, 1),
|
|
/* FUNC x */ /* [3] */
|
|
BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0), 2),
|
|
};
|
|
|
|
return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
|
|
strs, sizeof(strs)));
|
|
}
|
|
|
|
static int probe_kern_btf_func_global(void)
|
|
{
|
|
static const char strs[] = "\0int\0x\0a";
|
|
/* static void x(int a) {} */
|
|
__u32 types[] = {
|
|
/* int */
|
|
BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
|
|
/* FUNC_PROTO */ /* [2] */
|
|
BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 1), 0),
|
|
BTF_PARAM_ENC(7, 1),
|
|
/* FUNC x BTF_FUNC_GLOBAL */ /* [3] */
|
|
BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, BTF_FUNC_GLOBAL), 2),
|
|
};
|
|
|
|
return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
|
|
strs, sizeof(strs)));
|
|
}
|
|
|
|
static int probe_kern_btf_datasec(void)
|
|
{
|
|
static const char strs[] = "\0x\0.data";
|
|
/* static int a; */
|
|
__u32 types[] = {
|
|
/* int */
|
|
BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
|
|
/* VAR x */ /* [2] */
|
|
BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
|
|
BTF_VAR_STATIC,
|
|
/* DATASEC val */ /* [3] */
|
|
BTF_TYPE_ENC(3, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
|
|
BTF_VAR_SECINFO_ENC(2, 0, 4),
|
|
};
|
|
|
|
return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
|
|
strs, sizeof(strs)));
|
|
}
|
|
|
|
static int probe_kern_btf_float(void)
|
|
{
|
|
static const char strs[] = "\0float";
|
|
__u32 types[] = {
|
|
/* float */
|
|
BTF_TYPE_FLOAT_ENC(1, 4),
|
|
};
|
|
|
|
return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
|
|
strs, sizeof(strs)));
|
|
}
|
|
|
|
static int probe_kern_btf_decl_tag(void)
|
|
{
|
|
static const char strs[] = "\0tag";
|
|
__u32 types[] = {
|
|
/* int */
|
|
BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
|
|
/* VAR x */ /* [2] */
|
|
BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
|
|
BTF_VAR_STATIC,
|
|
/* attr */
|
|
BTF_TYPE_DECL_TAG_ENC(1, 2, -1),
|
|
};
|
|
|
|
return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
|
|
strs, sizeof(strs)));
|
|
}
|
|
|
|
static int probe_kern_btf_type_tag(void)
|
|
{
|
|
static const char strs[] = "\0tag";
|
|
__u32 types[] = {
|
|
/* int */
|
|
BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
|
|
/* attr */
|
|
BTF_TYPE_TYPE_TAG_ENC(1, 1), /* [2] */
|
|
/* ptr */
|
|
BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 2), /* [3] */
|
|
};
|
|
|
|
return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
|
|
strs, sizeof(strs)));
|
|
}
|
|
|
|
static int probe_kern_array_mmap(void)
|
|
{
|
|
LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_MMAPABLE);
|
|
int fd;
|
|
|
|
fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, sizeof(int), sizeof(int), 1, &opts);
|
|
return probe_fd(fd);
|
|
}
|
|
|
|
static int probe_kern_exp_attach_type(void)
|
|
{
|
|
LIBBPF_OPTS(bpf_prog_load_opts, opts, .expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE);
|
|
struct bpf_insn insns[] = {
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
BPF_EXIT_INSN(),
|
|
};
|
|
int fd, insn_cnt = ARRAY_SIZE(insns);
|
|
|
|
/* use any valid combination of program type and (optional)
|
|
* non-zero expected attach type (i.e., not a BPF_CGROUP_INET_INGRESS)
|
|
* to see if kernel supports expected_attach_type field for
|
|
* BPF_PROG_LOAD command
|
|
*/
|
|
fd = bpf_prog_load(BPF_PROG_TYPE_CGROUP_SOCK, NULL, "GPL", insns, insn_cnt, &opts);
|
|
return probe_fd(fd);
|
|
}
|
|
|
|
static int probe_kern_probe_read_kernel(void)
|
|
{
|
|
struct bpf_insn insns[] = {
|
|
BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), /* r1 = r10 (fp) */
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), /* r1 += -8 */
|
|
BPF_MOV64_IMM(BPF_REG_2, 8), /* r2 = 8 */
|
|
BPF_MOV64_IMM(BPF_REG_3, 0), /* r3 = 0 */
|
|
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_probe_read_kernel),
|
|
BPF_EXIT_INSN(),
|
|
};
|
|
int fd, insn_cnt = ARRAY_SIZE(insns);
|
|
|
|
fd = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL", insns, insn_cnt, NULL);
|
|
return probe_fd(fd);
|
|
}
|
|
|
|
static int probe_prog_bind_map(void)
|
|
{
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
struct bpf_insn insns[] = {
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
BPF_EXIT_INSN(),
|
|
};
|
|
int ret, map, prog, insn_cnt = ARRAY_SIZE(insns);
|
|
|
|
map = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, sizeof(int), 32, 1, NULL);
|
|
if (map < 0) {
|
|
ret = -errno;
|
|
cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
|
|
pr_warn("Error in %s():%s(%d). Couldn't create simple array map.\n",
|
|
__func__, cp, -ret);
|
|
return ret;
|
|
}
|
|
|
|
prog = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", insns, insn_cnt, NULL);
|
|
if (prog < 0) {
|
|
close(map);
|
|
return 0;
|
|
}
|
|
|
|
ret = bpf_prog_bind_map(prog, map, NULL);
|
|
|
|
close(map);
|
|
close(prog);
|
|
|
|
return ret >= 0;
|
|
}
|
|
|
|
static int probe_module_btf(void)
|
|
{
|
|
static const char strs[] = "\0int";
|
|
__u32 types[] = {
|
|
/* int */
|
|
BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4),
|
|
};
|
|
struct bpf_btf_info info;
|
|
__u32 len = sizeof(info);
|
|
char name[16];
|
|
int fd, err;
|
|
|
|
fd = libbpf__load_raw_btf((char *)types, sizeof(types), strs, sizeof(strs));
|
|
if (fd < 0)
|
|
return 0; /* BTF not supported at all */
|
|
|
|
memset(&info, 0, sizeof(info));
|
|
info.name = ptr_to_u64(name);
|
|
info.name_len = sizeof(name);
|
|
|
|
/* check that BPF_OBJ_GET_INFO_BY_FD supports specifying name pointer;
|
|
* kernel's module BTF support coincides with support for
|
|
* name/name_len fields in struct bpf_btf_info.
|
|
*/
|
|
err = bpf_obj_get_info_by_fd(fd, &info, &len);
|
|
close(fd);
|
|
return !err;
|
|
}
|
|
|
|
static int probe_perf_link(void)
|
|
{
|
|
struct bpf_insn insns[] = {
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
BPF_EXIT_INSN(),
|
|
};
|
|
int prog_fd, link_fd, err;
|
|
|
|
prog_fd = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL",
|
|
insns, ARRAY_SIZE(insns), NULL);
|
|
if (prog_fd < 0)
|
|
return -errno;
|
|
|
|
/* use invalid perf_event FD to get EBADF, if link is supported;
|
|
* otherwise EINVAL should be returned
|
|
*/
|
|
link_fd = bpf_link_create(prog_fd, -1, BPF_PERF_EVENT, NULL);
|
|
err = -errno; /* close() can clobber errno */
|
|
|
|
if (link_fd >= 0)
|
|
close(link_fd);
|
|
close(prog_fd);
|
|
|
|
return link_fd < 0 && err == -EBADF;
|
|
}
|
|
|
|
static int probe_kern_bpf_cookie(void)
|
|
{
|
|
struct bpf_insn insns[] = {
|
|
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_attach_cookie),
|
|
BPF_EXIT_INSN(),
|
|
};
|
|
int ret, insn_cnt = ARRAY_SIZE(insns);
|
|
|
|
ret = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, "GPL", insns, insn_cnt, NULL);
|
|
return probe_fd(ret);
|
|
}
|
|
|
|
enum kern_feature_result {
|
|
FEAT_UNKNOWN = 0,
|
|
FEAT_SUPPORTED = 1,
|
|
FEAT_MISSING = 2,
|
|
};
|
|
|
|
typedef int (*feature_probe_fn)(void);
|
|
|
|
static struct kern_feature_desc {
|
|
const char *desc;
|
|
feature_probe_fn probe;
|
|
enum kern_feature_result res;
|
|
} feature_probes[__FEAT_CNT] = {
|
|
[FEAT_PROG_NAME] = {
|
|
"BPF program name", probe_kern_prog_name,
|
|
},
|
|
[FEAT_GLOBAL_DATA] = {
|
|
"global variables", probe_kern_global_data,
|
|
},
|
|
[FEAT_BTF] = {
|
|
"minimal BTF", probe_kern_btf,
|
|
},
|
|
[FEAT_BTF_FUNC] = {
|
|
"BTF functions", probe_kern_btf_func,
|
|
},
|
|
[FEAT_BTF_GLOBAL_FUNC] = {
|
|
"BTF global function", probe_kern_btf_func_global,
|
|
},
|
|
[FEAT_BTF_DATASEC] = {
|
|
"BTF data section and variable", probe_kern_btf_datasec,
|
|
},
|
|
[FEAT_ARRAY_MMAP] = {
|
|
"ARRAY map mmap()", probe_kern_array_mmap,
|
|
},
|
|
[FEAT_EXP_ATTACH_TYPE] = {
|
|
"BPF_PROG_LOAD expected_attach_type attribute",
|
|
probe_kern_exp_attach_type,
|
|
},
|
|
[FEAT_PROBE_READ_KERN] = {
|
|
"bpf_probe_read_kernel() helper", probe_kern_probe_read_kernel,
|
|
},
|
|
[FEAT_PROG_BIND_MAP] = {
|
|
"BPF_PROG_BIND_MAP support", probe_prog_bind_map,
|
|
},
|
|
[FEAT_MODULE_BTF] = {
|
|
"module BTF support", probe_module_btf,
|
|
},
|
|
[FEAT_BTF_FLOAT] = {
|
|
"BTF_KIND_FLOAT support", probe_kern_btf_float,
|
|
},
|
|
[FEAT_PERF_LINK] = {
|
|
"BPF perf link support", probe_perf_link,
|
|
},
|
|
[FEAT_BTF_DECL_TAG] = {
|
|
"BTF_KIND_DECL_TAG support", probe_kern_btf_decl_tag,
|
|
},
|
|
[FEAT_BTF_TYPE_TAG] = {
|
|
"BTF_KIND_TYPE_TAG support", probe_kern_btf_type_tag,
|
|
},
|
|
[FEAT_MEMCG_ACCOUNT] = {
|
|
"memcg-based memory accounting", probe_memcg_account,
|
|
},
|
|
[FEAT_BPF_COOKIE] = {
|
|
"BPF cookie support", probe_kern_bpf_cookie,
|
|
},
|
|
};
|
|
|
|
bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id)
|
|
{
|
|
struct kern_feature_desc *feat = &feature_probes[feat_id];
|
|
int ret;
|
|
|
|
if (obj && obj->gen_loader)
|
|
/* To generate loader program assume the latest kernel
|
|
* to avoid doing extra prog_load, map_create syscalls.
|
|
*/
|
|
return true;
|
|
|
|
if (READ_ONCE(feat->res) == FEAT_UNKNOWN) {
|
|
ret = feat->probe();
|
|
if (ret > 0) {
|
|
WRITE_ONCE(feat->res, FEAT_SUPPORTED);
|
|
} else if (ret == 0) {
|
|
WRITE_ONCE(feat->res, FEAT_MISSING);
|
|
} else {
|
|
pr_warn("Detection of kernel %s support failed: %d\n", feat->desc, ret);
|
|
WRITE_ONCE(feat->res, FEAT_MISSING);
|
|
}
|
|
}
|
|
|
|
return READ_ONCE(feat->res) == FEAT_SUPPORTED;
|
|
}
|
|
|
|
static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd)
|
|
{
|
|
struct bpf_map_info map_info = {};
|
|
char msg[STRERR_BUFSIZE];
|
|
__u32 map_info_len;
|
|
int err;
|
|
|
|
map_info_len = sizeof(map_info);
|
|
|
|
err = bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len);
|
|
if (err && errno == EINVAL)
|
|
err = bpf_get_map_info_from_fdinfo(map_fd, &map_info);
|
|
if (err) {
|
|
pr_warn("failed to get map info for map FD %d: %s\n", map_fd,
|
|
libbpf_strerror_r(errno, msg, sizeof(msg)));
|
|
return false;
|
|
}
|
|
|
|
return (map_info.type == map->def.type &&
|
|
map_info.key_size == map->def.key_size &&
|
|
map_info.value_size == map->def.value_size &&
|
|
map_info.max_entries == map->def.max_entries &&
|
|
map_info.map_flags == map->def.map_flags &&
|
|
map_info.map_extra == map->map_extra);
|
|
}
|
|
|
|
static int
|
|
bpf_object__reuse_map(struct bpf_map *map)
|
|
{
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
int err, pin_fd;
|
|
|
|
pin_fd = bpf_obj_get(map->pin_path);
|
|
if (pin_fd < 0) {
|
|
err = -errno;
|
|
if (err == -ENOENT) {
|
|
pr_debug("found no pinned map to reuse at '%s'\n",
|
|
map->pin_path);
|
|
return 0;
|
|
}
|
|
|
|
cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg));
|
|
pr_warn("couldn't retrieve pinned map '%s': %s\n",
|
|
map->pin_path, cp);
|
|
return err;
|
|
}
|
|
|
|
if (!map_is_reuse_compat(map, pin_fd)) {
|
|
pr_warn("couldn't reuse pinned map at '%s': parameter mismatch\n",
|
|
map->pin_path);
|
|
close(pin_fd);
|
|
return -EINVAL;
|
|
}
|
|
|
|
err = bpf_map__reuse_fd(map, pin_fd);
|
|
close(pin_fd);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
map->pinned = true;
|
|
pr_debug("reused pinned map at '%s'\n", map->pin_path);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
|
|
{
|
|
enum libbpf_map_type map_type = map->libbpf_type;
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
int err, zero = 0;
|
|
|
|
if (obj->gen_loader) {
|
|
bpf_gen__map_update_elem(obj->gen_loader, map - obj->maps,
|
|
map->mmaped, map->def.value_size);
|
|
if (map_type == LIBBPF_MAP_RODATA || map_type == LIBBPF_MAP_KCONFIG)
|
|
bpf_gen__map_freeze(obj->gen_loader, map - obj->maps);
|
|
return 0;
|
|
}
|
|
err = bpf_map_update_elem(map->fd, &zero, map->mmaped, 0);
|
|
if (err) {
|
|
err = -errno;
|
|
cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
|
|
pr_warn("Error setting initial map(%s) contents: %s\n",
|
|
map->name, cp);
|
|
return err;
|
|
}
|
|
|
|
/* Freeze .rodata and .kconfig map as read-only from syscall side. */
|
|
if (map_type == LIBBPF_MAP_RODATA || map_type == LIBBPF_MAP_KCONFIG) {
|
|
err = bpf_map_freeze(map->fd);
|
|
if (err) {
|
|
err = -errno;
|
|
cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
|
|
pr_warn("Error freezing map(%s) as read-only: %s\n",
|
|
map->name, cp);
|
|
return err;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void bpf_map__destroy(struct bpf_map *map);
|
|
|
|
static bool is_pow_of_2(size_t x)
|
|
{
|
|
return x && (x & (x - 1));
|
|
}
|
|
|
|
static size_t adjust_ringbuf_sz(size_t sz)
|
|
{
|
|
__u32 page_sz = sysconf(_SC_PAGE_SIZE);
|
|
__u32 mul;
|
|
|
|
/* if user forgot to set any size, make sure they see error */
|
|
if (sz == 0)
|
|
return 0;
|
|
/* Kernel expects BPF_MAP_TYPE_RINGBUF's max_entries to be
|
|
* a power-of-2 multiple of kernel's page size. If user diligently
|
|
* satisified these conditions, pass the size through.
|
|
*/
|
|
if ((sz % page_sz) == 0 && is_pow_of_2(sz / page_sz))
|
|
return sz;
|
|
|
|
/* Otherwise find closest (page_sz * power_of_2) product bigger than
|
|
* user-set size to satisfy both user size request and kernel
|
|
* requirements and substitute correct max_entries for map creation.
|
|
*/
|
|
for (mul = 1; mul <= UINT_MAX / page_sz; mul <<= 1) {
|
|
if (mul * page_sz > sz)
|
|
return mul * page_sz;
|
|
}
|
|
|
|
/* if it's impossible to satisfy the conditions (i.e., user size is
|
|
* very close to UINT_MAX but is not a power-of-2 multiple of
|
|
* page_size) then just return original size and let kernel reject it
|
|
*/
|
|
return sz;
|
|
}
|
|
|
|
static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, bool is_inner)
|
|
{
|
|
LIBBPF_OPTS(bpf_map_create_opts, create_attr);
|
|
struct bpf_map_def *def = &map->def;
|
|
const char *map_name = NULL;
|
|
int err = 0;
|
|
|
|
if (kernel_supports(obj, FEAT_PROG_NAME))
|
|
map_name = map->name;
|
|
create_attr.map_ifindex = map->map_ifindex;
|
|
create_attr.map_flags = def->map_flags;
|
|
create_attr.numa_node = map->numa_node;
|
|
create_attr.map_extra = map->map_extra;
|
|
|
|
if (bpf_map__is_struct_ops(map))
|
|
create_attr.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
|
|
|
|
if (obj->btf && btf__fd(obj->btf) >= 0) {
|
|
create_attr.btf_fd = btf__fd(obj->btf);
|
|
create_attr.btf_key_type_id = map->btf_key_type_id;
|
|
create_attr.btf_value_type_id = map->btf_value_type_id;
|
|
}
|
|
|
|
if (bpf_map_type__is_map_in_map(def->type)) {
|
|
if (map->inner_map) {
|
|
err = bpf_object__create_map(obj, map->inner_map, true);
|
|
if (err) {
|
|
pr_warn("map '%s': failed to create inner map: %d\n",
|
|
map->name, err);
|
|
return err;
|
|
}
|
|
map->inner_map_fd = bpf_map__fd(map->inner_map);
|
|
}
|
|
if (map->inner_map_fd >= 0)
|
|
create_attr.inner_map_fd = map->inner_map_fd;
|
|
}
|
|
|
|
switch (def->type) {
|
|
case BPF_MAP_TYPE_RINGBUF:
|
|
map->def.max_entries = adjust_ringbuf_sz(map->def.max_entries);
|
|
/* fallthrough */
|
|
case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
|
|
case BPF_MAP_TYPE_CGROUP_ARRAY:
|
|
case BPF_MAP_TYPE_STACK_TRACE:
|
|
case BPF_MAP_TYPE_ARRAY_OF_MAPS:
|
|
case BPF_MAP_TYPE_HASH_OF_MAPS:
|
|
case BPF_MAP_TYPE_DEVMAP:
|
|
case BPF_MAP_TYPE_DEVMAP_HASH:
|
|
case BPF_MAP_TYPE_CPUMAP:
|
|
case BPF_MAP_TYPE_XSKMAP:
|
|
case BPF_MAP_TYPE_SOCKMAP:
|
|
case BPF_MAP_TYPE_SOCKHASH:
|
|
case BPF_MAP_TYPE_QUEUE:
|
|
case BPF_MAP_TYPE_STACK:
|
|
create_attr.btf_fd = 0;
|
|
create_attr.btf_key_type_id = 0;
|
|
create_attr.btf_value_type_id = 0;
|
|
map->btf_key_type_id = 0;
|
|
map->btf_value_type_id = 0;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
if (obj->gen_loader) {
|
|
bpf_gen__map_create(obj->gen_loader, def->type, map_name,
|
|
def->key_size, def->value_size, def->max_entries,
|
|
&create_attr, is_inner ? -1 : map - obj->maps);
|
|
/* Pretend to have valid FD to pass various fd >= 0 checks.
|
|
* This fd == 0 will not be used with any syscall and will be reset to -1 eventually.
|
|
*/
|
|
map->fd = 0;
|
|
} else {
|
|
map->fd = bpf_map_create(def->type, map_name,
|
|
def->key_size, def->value_size,
|
|
def->max_entries, &create_attr);
|
|
}
|
|
if (map->fd < 0 && (create_attr.btf_key_type_id ||
|
|
create_attr.btf_value_type_id)) {
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
|
|
err = -errno;
|
|
cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
|
|
pr_warn("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n",
|
|
map->name, cp, err);
|
|
create_attr.btf_fd = 0;
|
|
create_attr.btf_key_type_id = 0;
|
|
create_attr.btf_value_type_id = 0;
|
|
map->btf_key_type_id = 0;
|
|
map->btf_value_type_id = 0;
|
|
map->fd = bpf_map_create(def->type, map_name,
|
|
def->key_size, def->value_size,
|
|
def->max_entries, &create_attr);
|
|
}
|
|
|
|
err = map->fd < 0 ? -errno : 0;
|
|
|
|
if (bpf_map_type__is_map_in_map(def->type) && map->inner_map) {
|
|
if (obj->gen_loader)
|
|
map->inner_map->fd = -1;
|
|
bpf_map__destroy(map->inner_map);
|
|
zfree(&map->inner_map);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int init_map_in_map_slots(struct bpf_object *obj, struct bpf_map *map)
|
|
{
|
|
const struct bpf_map *targ_map;
|
|
unsigned int i;
|
|
int fd, err = 0;
|
|
|
|
for (i = 0; i < map->init_slots_sz; i++) {
|
|
if (!map->init_slots[i])
|
|
continue;
|
|
|
|
targ_map = map->init_slots[i];
|
|
fd = bpf_map__fd(targ_map);
|
|
|
|
if (obj->gen_loader) {
|
|
bpf_gen__populate_outer_map(obj->gen_loader,
|
|
map - obj->maps, i,
|
|
targ_map - obj->maps);
|
|
} else {
|
|
err = bpf_map_update_elem(map->fd, &i, &fd, 0);
|
|
}
|
|
if (err) {
|
|
err = -errno;
|
|
pr_warn("map '%s': failed to initialize slot [%d] to map '%s' fd=%d: %d\n",
|
|
map->name, i, targ_map->name, fd, err);
|
|
return err;
|
|
}
|
|
pr_debug("map '%s': slot [%d] set to map '%s' fd=%d\n",
|
|
map->name, i, targ_map->name, fd);
|
|
}
|
|
|
|
zfree(&map->init_slots);
|
|
map->init_slots_sz = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int init_prog_array_slots(struct bpf_object *obj, struct bpf_map *map)
|
|
{
|
|
const struct bpf_program *targ_prog;
|
|
unsigned int i;
|
|
int fd, err;
|
|
|
|
if (obj->gen_loader)
|
|
return -ENOTSUP;
|
|
|
|
for (i = 0; i < map->init_slots_sz; i++) {
|
|
if (!map->init_slots[i])
|
|
continue;
|
|
|
|
targ_prog = map->init_slots[i];
|
|
fd = bpf_program__fd(targ_prog);
|
|
|
|
err = bpf_map_update_elem(map->fd, &i, &fd, 0);
|
|
if (err) {
|
|
err = -errno;
|
|
pr_warn("map '%s': failed to initialize slot [%d] to prog '%s' fd=%d: %d\n",
|
|
map->name, i, targ_prog->name, fd, err);
|
|
return err;
|
|
}
|
|
pr_debug("map '%s': slot [%d] set to prog '%s' fd=%d\n",
|
|
map->name, i, targ_prog->name, fd);
|
|
}
|
|
|
|
zfree(&map->init_slots);
|
|
map->init_slots_sz = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object_init_prog_arrays(struct bpf_object *obj)
|
|
{
|
|
struct bpf_map *map;
|
|
int i, err;
|
|
|
|
for (i = 0; i < obj->nr_maps; i++) {
|
|
map = &obj->maps[i];
|
|
|
|
if (!map->init_slots_sz || map->def.type != BPF_MAP_TYPE_PROG_ARRAY)
|
|
continue;
|
|
|
|
err = init_prog_array_slots(obj, map);
|
|
if (err < 0) {
|
|
zclose(map->fd);
|
|
return err;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int map_set_def_max_entries(struct bpf_map *map)
|
|
{
|
|
if (map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && !map->def.max_entries) {
|
|
int nr_cpus;
|
|
|
|
nr_cpus = libbpf_num_possible_cpus();
|
|
if (nr_cpus < 0) {
|
|
pr_warn("map '%s': failed to determine number of system CPUs: %d\n",
|
|
map->name, nr_cpus);
|
|
return nr_cpus;
|
|
}
|
|
pr_debug("map '%s': setting size to %d\n", map->name, nr_cpus);
|
|
map->def.max_entries = nr_cpus;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_object__create_maps(struct bpf_object *obj)
|
|
{
|
|
struct bpf_map *map;
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
unsigned int i, j;
|
|
int err;
|
|
bool retried;
|
|
|
|
for (i = 0; i < obj->nr_maps; i++) {
|
|
map = &obj->maps[i];
|
|
|
|
/* To support old kernels, we skip creating global data maps
|
|
* (.rodata, .data, .kconfig, etc); later on, during program
|
|
* loading, if we detect that at least one of the to-be-loaded
|
|
* programs is referencing any global data map, we'll error
|
|
* out with program name and relocation index logged.
|
|
* This approach allows to accommodate Clang emitting
|
|
* unnecessary .rodata.str1.1 sections for string literals,
|
|
* but also it allows to have CO-RE applications that use
|
|
* global variables in some of BPF programs, but not others.
|
|
* If those global variable-using programs are not loaded at
|
|
* runtime due to bpf_program__set_autoload(prog, false),
|
|
* bpf_object loading will succeed just fine even on old
|
|
* kernels.
|
|
*/
|
|
if (bpf_map__is_internal(map) && !kernel_supports(obj, FEAT_GLOBAL_DATA))
|
|
map->autocreate = false;
|
|
|
|
if (!map->autocreate) {
|
|
pr_debug("map '%s': skipped auto-creating...\n", map->name);
|
|
continue;
|
|
}
|
|
|
|
err = map_set_def_max_entries(map);
|
|
if (err)
|
|
goto err_out;
|
|
|
|
retried = false;
|
|
retry:
|
|
if (map->pin_path) {
|
|
err = bpf_object__reuse_map(map);
|
|
if (err) {
|
|
pr_warn("map '%s': error reusing pinned map\n",
|
|
map->name);
|
|
goto err_out;
|
|
}
|
|
if (retried && map->fd < 0) {
|
|
pr_warn("map '%s': cannot find pinned map\n",
|
|
map->name);
|
|
err = -ENOENT;
|
|
goto err_out;
|
|
}
|
|
}
|
|
|
|
if (map->fd >= 0) {
|
|
pr_debug("map '%s': skipping creation (preset fd=%d)\n",
|
|
map->name, map->fd);
|
|
} else {
|
|
err = bpf_object__create_map(obj, map, false);
|
|
if (err)
|
|
goto err_out;
|
|
|
|
pr_debug("map '%s': created successfully, fd=%d\n",
|
|
map->name, map->fd);
|
|
|
|
if (bpf_map__is_internal(map)) {
|
|
err = bpf_object__populate_internal_map(obj, map);
|
|
if (err < 0) {
|
|
zclose(map->fd);
|
|
goto err_out;
|
|
}
|
|
}
|
|
|
|
if (map->init_slots_sz && map->def.type != BPF_MAP_TYPE_PROG_ARRAY) {
|
|
err = init_map_in_map_slots(obj, map);
|
|
if (err < 0) {
|
|
zclose(map->fd);
|
|
goto err_out;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (map->pin_path && !map->pinned) {
|
|
err = bpf_map__pin(map, NULL);
|
|
if (err) {
|
|
zclose(map->fd);
|
|
if (!retried && err == -EEXIST) {
|
|
retried = true;
|
|
goto retry;
|
|
}
|
|
pr_warn("map '%s': failed to auto-pin at '%s': %d\n",
|
|
map->name, map->pin_path, err);
|
|
goto err_out;
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_out:
|
|
cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
|
|
pr_warn("map '%s': failed to create: %s(%d)\n", map->name, cp, err);
|
|
pr_perm_msg(err);
|
|
for (j = 0; j < i; j++)
|
|
zclose(obj->maps[j].fd);
|
|
return err;
|
|
}
|
|
|
|
static bool bpf_core_is_flavor_sep(const char *s)
|
|
{
|
|
/* check X___Y name pattern, where X and Y are not underscores */
|
|
return s[0] != '_' && /* X */
|
|
s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */
|
|
s[4] != '_'; /* Y */
|
|
}
|
|
|
|
/* Given 'some_struct_name___with_flavor' return the length of a name prefix
|
|
* before last triple underscore. Struct name part after last triple
|
|
* underscore is ignored by BPF CO-RE relocation during relocation matching.
|
|
*/
|
|
size_t bpf_core_essential_name_len(const char *name)
|
|
{
|
|
size_t n = strlen(name);
|
|
int i;
|
|
|
|
for (i = n - 5; i >= 0; i--) {
|
|
if (bpf_core_is_flavor_sep(name + i))
|
|
return i + 1;
|
|
}
|
|
return n;
|
|
}
|
|
|
|
void bpf_core_free_cands(struct bpf_core_cand_list *cands)
|
|
{
|
|
if (!cands)
|
|
return;
|
|
|
|
free(cands->cands);
|
|
free(cands);
|
|
}
|
|
|
|
int bpf_core_add_cands(struct bpf_core_cand *local_cand,
|
|
size_t local_essent_len,
|
|
const struct btf *targ_btf,
|
|
const char *targ_btf_name,
|
|
int targ_start_id,
|
|
struct bpf_core_cand_list *cands)
|
|
{
|
|
struct bpf_core_cand *new_cands, *cand;
|
|
const struct btf_type *t, *local_t;
|
|
const char *targ_name, *local_name;
|
|
size_t targ_essent_len;
|
|
int n, i;
|
|
|
|
local_t = btf__type_by_id(local_cand->btf, local_cand->id);
|
|
local_name = btf__str_by_offset(local_cand->btf, local_t->name_off);
|
|
|
|
n = btf__type_cnt(targ_btf);
|
|
for (i = targ_start_id; i < n; i++) {
|
|
t = btf__type_by_id(targ_btf, i);
|
|
if (btf_kind(t) != btf_kind(local_t))
|
|
continue;
|
|
|
|
targ_name = btf__name_by_offset(targ_btf, t->name_off);
|
|
if (str_is_empty(targ_name))
|
|
continue;
|
|
|
|
targ_essent_len = bpf_core_essential_name_len(targ_name);
|
|
if (targ_essent_len != local_essent_len)
|
|
continue;
|
|
|
|
if (strncmp(local_name, targ_name, local_essent_len) != 0)
|
|
continue;
|
|
|
|
pr_debug("CO-RE relocating [%d] %s %s: found target candidate [%d] %s %s in [%s]\n",
|
|
local_cand->id, btf_kind_str(local_t),
|
|
local_name, i, btf_kind_str(t), targ_name,
|
|
targ_btf_name);
|
|
new_cands = libbpf_reallocarray(cands->cands, cands->len + 1,
|
|
sizeof(*cands->cands));
|
|
if (!new_cands)
|
|
return -ENOMEM;
|
|
|
|
cand = &new_cands[cands->len];
|
|
cand->btf = targ_btf;
|
|
cand->id = i;
|
|
|
|
cands->cands = new_cands;
|
|
cands->len++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int load_module_btfs(struct bpf_object *obj)
|
|
{
|
|
struct bpf_btf_info info;
|
|
struct module_btf *mod_btf;
|
|
struct btf *btf;
|
|
char name[64];
|
|
__u32 id = 0, len;
|
|
int err, fd;
|
|
|
|
if (obj->btf_modules_loaded)
|
|
return 0;
|
|
|
|
if (obj->gen_loader)
|
|
return 0;
|
|
|
|
/* don't do this again, even if we find no module BTFs */
|
|
obj->btf_modules_loaded = true;
|
|
|
|
/* kernel too old to support module BTFs */
|
|
if (!kernel_supports(obj, FEAT_MODULE_BTF))
|
|
return 0;
|
|
|
|
while (true) {
|
|
err = bpf_btf_get_next_id(id, &id);
|
|
if (err && errno == ENOENT)
|
|
return 0;
|
|
if (err) {
|
|
err = -errno;
|
|
pr_warn("failed to iterate BTF objects: %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
fd = bpf_btf_get_fd_by_id(id);
|
|
if (fd < 0) {
|
|
if (errno == ENOENT)
|
|
continue; /* expected race: BTF was unloaded */
|
|
err = -errno;
|
|
pr_warn("failed to get BTF object #%d FD: %d\n", id, err);
|
|
return err;
|
|
}
|
|
|
|
len = sizeof(info);
|
|
memset(&info, 0, sizeof(info));
|
|
info.name = ptr_to_u64(name);
|
|
info.name_len = sizeof(name);
|
|
|
|
err = bpf_obj_get_info_by_fd(fd, &info, &len);
|
|
if (err) {
|
|
err = -errno;
|
|
pr_warn("failed to get BTF object #%d info: %d\n", id, err);
|
|
goto err_out;
|
|
}
|
|
|
|
/* ignore non-module BTFs */
|
|
if (!info.kernel_btf || strcmp(name, "vmlinux") == 0) {
|
|
close(fd);
|
|
continue;
|
|
}
|
|
|
|
btf = btf_get_from_fd(fd, obj->btf_vmlinux);
|
|
err = libbpf_get_error(btf);
|
|
if (err) {
|
|
pr_warn("failed to load module [%s]'s BTF object #%d: %d\n",
|
|
name, id, err);
|
|
goto err_out;
|
|
}
|
|
|
|
err = libbpf_ensure_mem((void **)&obj->btf_modules, &obj->btf_module_cap,
|
|
sizeof(*obj->btf_modules), obj->btf_module_cnt + 1);
|
|
if (err)
|
|
goto err_out;
|
|
|
|
mod_btf = &obj->btf_modules[obj->btf_module_cnt++];
|
|
|
|
mod_btf->btf = btf;
|
|
mod_btf->id = id;
|
|
mod_btf->fd = fd;
|
|
mod_btf->name = strdup(name);
|
|
if (!mod_btf->name) {
|
|
err = -ENOMEM;
|
|
goto err_out;
|
|
}
|
|
continue;
|
|
|
|
err_out:
|
|
close(fd);
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct bpf_core_cand_list *
|
|
bpf_core_find_cands(struct bpf_object *obj, const struct btf *local_btf, __u32 local_type_id)
|
|
{
|
|
struct bpf_core_cand local_cand = {};
|
|
struct bpf_core_cand_list *cands;
|
|
const struct btf *main_btf;
|
|
const struct btf_type *local_t;
|
|
const char *local_name;
|
|
size_t local_essent_len;
|
|
int err, i;
|
|
|
|
local_cand.btf = local_btf;
|
|
local_cand.id = local_type_id;
|
|
local_t = btf__type_by_id(local_btf, local_type_id);
|
|
if (!local_t)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
local_name = btf__name_by_offset(local_btf, local_t->name_off);
|
|
if (str_is_empty(local_name))
|
|
return ERR_PTR(-EINVAL);
|
|
local_essent_len = bpf_core_essential_name_len(local_name);
|
|
|
|
cands = calloc(1, sizeof(*cands));
|
|
if (!cands)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
/* Attempt to find target candidates in vmlinux BTF first */
|
|
main_btf = obj->btf_vmlinux_override ?: obj->btf_vmlinux;
|
|
err = bpf_core_add_cands(&local_cand, local_essent_len, main_btf, "vmlinux", 1, cands);
|
|
if (err)
|
|
goto err_out;
|
|
|
|
/* if vmlinux BTF has any candidate, don't got for module BTFs */
|
|
if (cands->len)
|
|
return cands;
|
|
|
|
/* if vmlinux BTF was overridden, don't attempt to load module BTFs */
|
|
if (obj->btf_vmlinux_override)
|
|
return cands;
|
|
|
|
/* now look through module BTFs, trying to still find candidates */
|
|
err = load_module_btfs(obj);
|
|
if (err)
|
|
goto err_out;
|
|
|
|
for (i = 0; i < obj->btf_module_cnt; i++) {
|
|
err = bpf_core_add_cands(&local_cand, local_essent_len,
|
|
obj->btf_modules[i].btf,
|
|
obj->btf_modules[i].name,
|
|
btf__type_cnt(obj->btf_vmlinux),
|
|
cands);
|
|
if (err)
|
|
goto err_out;
|
|
}
|
|
|
|
return cands;
|
|
err_out:
|
|
bpf_core_free_cands(cands);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
/* Check local and target types for compatibility. This check is used for
|
|
* type-based CO-RE relocations and follow slightly different rules than
|
|
* field-based relocations. This function assumes that root types were already
|
|
* checked for name match. Beyond that initial root-level name check, names
|
|
* are completely ignored. Compatibility rules are as follows:
|
|
* - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs are considered compatible, but
|
|
* kind should match for local and target types (i.e., STRUCT is not
|
|
* compatible with UNION);
|
|
* - for ENUMs, the size is ignored;
|
|
* - for INT, size and signedness are ignored;
|
|
* - for ARRAY, dimensionality is ignored, element types are checked for
|
|
* compatibility recursively;
|
|
* - CONST/VOLATILE/RESTRICT modifiers are ignored;
|
|
* - TYPEDEFs/PTRs are compatible if types they pointing to are compatible;
|
|
* - FUNC_PROTOs are compatible if they have compatible signature: same
|
|
* number of input args and compatible return and argument types.
|
|
* These rules are not set in stone and probably will be adjusted as we get
|
|
* more experience with using BPF CO-RE relocations.
|
|
*/
|
|
int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
|
|
const struct btf *targ_btf, __u32 targ_id)
|
|
{
|
|
const struct btf_type *local_type, *targ_type;
|
|
int depth = 32; /* max recursion depth */
|
|
|
|
/* caller made sure that names match (ignoring flavor suffix) */
|
|
local_type = btf__type_by_id(local_btf, local_id);
|
|
targ_type = btf__type_by_id(targ_btf, targ_id);
|
|
if (btf_kind(local_type) != btf_kind(targ_type))
|
|
return 0;
|
|
|
|
recur:
|
|
depth--;
|
|
if (depth < 0)
|
|
return -EINVAL;
|
|
|
|
local_type = skip_mods_and_typedefs(local_btf, local_id, &local_id);
|
|
targ_type = skip_mods_and_typedefs(targ_btf, targ_id, &targ_id);
|
|
if (!local_type || !targ_type)
|
|
return -EINVAL;
|
|
|
|
if (btf_kind(local_type) != btf_kind(targ_type))
|
|
return 0;
|
|
|
|
switch (btf_kind(local_type)) {
|
|
case BTF_KIND_UNKN:
|
|
case BTF_KIND_STRUCT:
|
|
case BTF_KIND_UNION:
|
|
case BTF_KIND_ENUM:
|
|
case BTF_KIND_FWD:
|
|
return 1;
|
|
case BTF_KIND_INT:
|
|
/* just reject deprecated bitfield-like integers; all other
|
|
* integers are by default compatible between each other
|
|
*/
|
|
return btf_int_offset(local_type) == 0 && btf_int_offset(targ_type) == 0;
|
|
case BTF_KIND_PTR:
|
|
local_id = local_type->type;
|
|
targ_id = targ_type->type;
|
|
goto recur;
|
|
case BTF_KIND_ARRAY:
|
|
local_id = btf_array(local_type)->type;
|
|
targ_id = btf_array(targ_type)->type;
|
|
goto recur;
|
|
case BTF_KIND_FUNC_PROTO: {
|
|
struct btf_param *local_p = btf_params(local_type);
|
|
struct btf_param *targ_p = btf_params(targ_type);
|
|
__u16 local_vlen = btf_vlen(local_type);
|
|
__u16 targ_vlen = btf_vlen(targ_type);
|
|
int i, err;
|
|
|
|
if (local_vlen != targ_vlen)
|
|
return 0;
|
|
|
|
for (i = 0; i < local_vlen; i++, local_p++, targ_p++) {
|
|
skip_mods_and_typedefs(local_btf, local_p->type, &local_id);
|
|
skip_mods_and_typedefs(targ_btf, targ_p->type, &targ_id);
|
|
err = bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id);
|
|
if (err <= 0)
|
|
return err;
|
|
}
|
|
|
|
/* tail recurse for return type check */
|
|
skip_mods_and_typedefs(local_btf, local_type->type, &local_id);
|
|
skip_mods_and_typedefs(targ_btf, targ_type->type, &targ_id);
|
|
goto recur;
|
|
}
|
|
default:
|
|
pr_warn("unexpected kind %s relocated, local [%d], target [%d]\n",
|
|
btf_kind_str(local_type), local_id, targ_id);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
static size_t bpf_core_hash_fn(const void *key, void *ctx)
|
|
{
|
|
return (size_t)key;
|
|
}
|
|
|
|
static bool bpf_core_equal_fn(const void *k1, const void *k2, void *ctx)
|
|
{
|
|
return k1 == k2;
|
|
}
|
|
|
|
static void *u32_as_hash_key(__u32 x)
|
|
{
|
|
return (void *)(uintptr_t)x;
|
|
}
|
|
|
|
static int record_relo_core(struct bpf_program *prog,
|
|
const struct bpf_core_relo *core_relo, int insn_idx)
|
|
{
|
|
struct reloc_desc *relos, *relo;
|
|
|
|
relos = libbpf_reallocarray(prog->reloc_desc,
|
|
prog->nr_reloc + 1, sizeof(*relos));
|
|
if (!relos)
|
|
return -ENOMEM;
|
|
relo = &relos[prog->nr_reloc];
|
|
relo->type = RELO_CORE;
|
|
relo->insn_idx = insn_idx;
|
|
relo->core_relo = core_relo;
|
|
prog->reloc_desc = relos;
|
|
prog->nr_reloc++;
|
|
return 0;
|
|
}
|
|
|
|
static const struct bpf_core_relo *find_relo_core(struct bpf_program *prog, int insn_idx)
|
|
{
|
|
struct reloc_desc *relo;
|
|
int i;
|
|
|
|
for (i = 0; i < prog->nr_reloc; i++) {
|
|
relo = &prog->reloc_desc[i];
|
|
if (relo->type != RELO_CORE || relo->insn_idx != insn_idx)
|
|
continue;
|
|
|
|
return relo->core_relo;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static int bpf_core_resolve_relo(struct bpf_program *prog,
|
|
const struct bpf_core_relo *relo,
|
|
int relo_idx,
|
|
const struct btf *local_btf,
|
|
struct hashmap *cand_cache,
|
|
struct bpf_core_relo_res *targ_res)
|
|
{
|
|
struct bpf_core_spec specs_scratch[3] = {};
|
|
const void *type_key = u32_as_hash_key(relo->type_id);
|
|
struct bpf_core_cand_list *cands = NULL;
|
|
const char *prog_name = prog->name;
|
|
const struct btf_type *local_type;
|
|
const char *local_name;
|
|
__u32 local_id = relo->type_id;
|
|
int err;
|
|
|
|
local_type = btf__type_by_id(local_btf, local_id);
|
|
if (!local_type)
|
|
return -EINVAL;
|
|
|
|
local_name = btf__name_by_offset(local_btf, local_type->name_off);
|
|
if (!local_name)
|
|
return -EINVAL;
|
|
|
|
if (relo->kind != BPF_CORE_TYPE_ID_LOCAL &&
|
|
!hashmap__find(cand_cache, type_key, (void **)&cands)) {
|
|
cands = bpf_core_find_cands(prog->obj, local_btf, local_id);
|
|
if (IS_ERR(cands)) {
|
|
pr_warn("prog '%s': relo #%d: target candidate search failed for [%d] %s %s: %ld\n",
|
|
prog_name, relo_idx, local_id, btf_kind_str(local_type),
|
|
local_name, PTR_ERR(cands));
|
|
return PTR_ERR(cands);
|
|
}
|
|
err = hashmap__set(cand_cache, type_key, cands, NULL, NULL);
|
|
if (err) {
|
|
bpf_core_free_cands(cands);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return bpf_core_calc_relo_insn(prog_name, relo, relo_idx, local_btf, cands, specs_scratch,
|
|
targ_res);
|
|
}
|
|
|
|
static int
|
|
bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path)
|
|
{
|
|
const struct btf_ext_info_sec *sec;
|
|
struct bpf_core_relo_res targ_res;
|
|
const struct bpf_core_relo *rec;
|
|
const struct btf_ext_info *seg;
|
|
struct hashmap_entry *entry;
|
|
struct hashmap *cand_cache = NULL;
|
|
struct bpf_program *prog;
|
|
struct bpf_insn *insn;
|
|
const char *sec_name;
|
|
int i, err = 0, insn_idx, sec_idx, sec_num;
|
|
|
|
if (obj->btf_ext->core_relo_info.len == 0)
|
|
return 0;
|
|
|
|
if (targ_btf_path) {
|
|
obj->btf_vmlinux_override = btf__parse(targ_btf_path, NULL);
|
|
err = libbpf_get_error(obj->btf_vmlinux_override);
|
|
if (err) {
|
|
pr_warn("failed to parse target BTF: %d\n", err);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
cand_cache = hashmap__new(bpf_core_hash_fn, bpf_core_equal_fn, NULL);
|
|
if (IS_ERR(cand_cache)) {
|
|
err = PTR_ERR(cand_cache);
|
|
goto out;
|
|
}
|
|
|
|
seg = &obj->btf_ext->core_relo_info;
|
|
sec_num = 0;
|
|
for_each_btf_ext_sec(seg, sec) {
|
|
sec_idx = seg->sec_idxs[sec_num];
|
|
sec_num++;
|
|
|
|
sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
|
|
if (str_is_empty(sec_name)) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
pr_debug("sec '%s': found %d CO-RE relocations\n", sec_name, sec->num_info);
|
|
|
|
for_each_btf_ext_rec(seg, sec, i, rec) {
|
|
if (rec->insn_off % BPF_INSN_SZ)
|
|
return -EINVAL;
|
|
insn_idx = rec->insn_off / BPF_INSN_SZ;
|
|
prog = find_prog_by_sec_insn(obj, sec_idx, insn_idx);
|
|
if (!prog) {
|
|
/* When __weak subprog is "overridden" by another instance
|
|
* of the subprog from a different object file, linker still
|
|
* appends all the .BTF.ext info that used to belong to that
|
|
* eliminated subprogram.
|
|
* This is similar to what x86-64 linker does for relocations.
|
|
* So just ignore such relocations just like we ignore
|
|
* subprog instructions when discovering subprograms.
|
|
*/
|
|
pr_debug("sec '%s': skipping CO-RE relocation #%d for insn #%d belonging to eliminated weak subprogram\n",
|
|
sec_name, i, insn_idx);
|
|
continue;
|
|
}
|
|
/* no need to apply CO-RE relocation if the program is
|
|
* not going to be loaded
|
|
*/
|
|
if (!prog->autoload)
|
|
continue;
|
|
|
|
/* adjust insn_idx from section frame of reference to the local
|
|
* program's frame of reference; (sub-)program code is not yet
|
|
* relocated, so it's enough to just subtract in-section offset
|
|
*/
|
|
insn_idx = insn_idx - prog->sec_insn_off;
|
|
if (insn_idx >= prog->insns_cnt)
|
|
return -EINVAL;
|
|
insn = &prog->insns[insn_idx];
|
|
|
|
err = record_relo_core(prog, rec, insn_idx);
|
|
if (err) {
|
|
pr_warn("prog '%s': relo #%d: failed to record relocation: %d\n",
|
|
prog->name, i, err);
|
|
goto out;
|
|
}
|
|
|
|
if (prog->obj->gen_loader)
|
|
continue;
|
|
|
|
err = bpf_core_resolve_relo(prog, rec, i, obj->btf, cand_cache, &targ_res);
|
|
if (err) {
|
|
pr_warn("prog '%s': relo #%d: failed to relocate: %d\n",
|
|
prog->name, i, err);
|
|
goto out;
|
|
}
|
|
|
|
err = bpf_core_patch_insn(prog->name, insn, insn_idx, rec, i, &targ_res);
|
|
if (err) {
|
|
pr_warn("prog '%s': relo #%d: failed to patch insn #%u: %d\n",
|
|
prog->name, i, insn_idx, err);
|
|
goto out;
|
|
}
|
|
}
|
|
}
|
|
|
|
out:
|
|
/* obj->btf_vmlinux and module BTFs are freed after object load */
|
|
btf__free(obj->btf_vmlinux_override);
|
|
obj->btf_vmlinux_override = NULL;
|
|
|
|
if (!IS_ERR_OR_NULL(cand_cache)) {
|
|
hashmap__for_each_entry(cand_cache, entry, i) {
|
|
bpf_core_free_cands(entry->value);
|
|
}
|
|
hashmap__free(cand_cache);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/* base map load ldimm64 special constant, used also for log fixup logic */
|
|
#define MAP_LDIMM64_POISON_BASE 2001000000
|
|
#define MAP_LDIMM64_POISON_PFX "200100"
|
|
|
|
static void poison_map_ldimm64(struct bpf_program *prog, int relo_idx,
|
|
int insn_idx, struct bpf_insn *insn,
|
|
int map_idx, const struct bpf_map *map)
|
|
{
|
|
int i;
|
|
|
|
pr_debug("prog '%s': relo #%d: poisoning insn #%d that loads map #%d '%s'\n",
|
|
prog->name, relo_idx, insn_idx, map_idx, map->name);
|
|
|
|
/* we turn single ldimm64 into two identical invalid calls */
|
|
for (i = 0; i < 2; i++) {
|
|
insn->code = BPF_JMP | BPF_CALL;
|
|
insn->dst_reg = 0;
|
|
insn->src_reg = 0;
|
|
insn->off = 0;
|
|
/* if this instruction is reachable (not a dead code),
|
|
* verifier will complain with something like:
|
|
* invalid func unknown#2001000123
|
|
* where lower 123 is map index into obj->maps[] array
|
|
*/
|
|
insn->imm = MAP_LDIMM64_POISON_BASE + map_idx;
|
|
|
|
insn++;
|
|
}
|
|
}
|
|
|
|
/* Relocate data references within program code:
|
|
* - map references;
|
|
* - global variable references;
|
|
* - extern references.
|
|
*/
|
|
static int
|
|
bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < prog->nr_reloc; i++) {
|
|
struct reloc_desc *relo = &prog->reloc_desc[i];
|
|
struct bpf_insn *insn = &prog->insns[relo->insn_idx];
|
|
const struct bpf_map *map;
|
|
struct extern_desc *ext;
|
|
|
|
switch (relo->type) {
|
|
case RELO_LD64:
|
|
map = &obj->maps[relo->map_idx];
|
|
if (obj->gen_loader) {
|
|
insn[0].src_reg = BPF_PSEUDO_MAP_IDX;
|
|
insn[0].imm = relo->map_idx;
|
|
} else if (map->autocreate) {
|
|
insn[0].src_reg = BPF_PSEUDO_MAP_FD;
|
|
insn[0].imm = map->fd;
|
|
} else {
|
|
poison_map_ldimm64(prog, i, relo->insn_idx, insn,
|
|
relo->map_idx, map);
|
|
}
|
|
break;
|
|
case RELO_DATA:
|
|
map = &obj->maps[relo->map_idx];
|
|
insn[1].imm = insn[0].imm + relo->sym_off;
|
|
if (obj->gen_loader) {
|
|
insn[0].src_reg = BPF_PSEUDO_MAP_IDX_VALUE;
|
|
insn[0].imm = relo->map_idx;
|
|
} else if (map->autocreate) {
|
|
insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;
|
|
insn[0].imm = map->fd;
|
|
} else {
|
|
poison_map_ldimm64(prog, i, relo->insn_idx, insn,
|
|
relo->map_idx, map);
|
|
}
|
|
break;
|
|
case RELO_EXTERN_VAR:
|
|
ext = &obj->externs[relo->sym_off];
|
|
if (ext->type == EXT_KCFG) {
|
|
if (obj->gen_loader) {
|
|
insn[0].src_reg = BPF_PSEUDO_MAP_IDX_VALUE;
|
|
insn[0].imm = obj->kconfig_map_idx;
|
|
} else {
|
|
insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;
|
|
insn[0].imm = obj->maps[obj->kconfig_map_idx].fd;
|
|
}
|
|
insn[1].imm = ext->kcfg.data_off;
|
|
} else /* EXT_KSYM */ {
|
|
if (ext->ksym.type_id && ext->is_set) { /* typed ksyms */
|
|
insn[0].src_reg = BPF_PSEUDO_BTF_ID;
|
|
insn[0].imm = ext->ksym.kernel_btf_id;
|
|
insn[1].imm = ext->ksym.kernel_btf_obj_fd;
|
|
} else { /* typeless ksyms or unresolved typed ksyms */
|
|
insn[0].imm = (__u32)ext->ksym.addr;
|
|
insn[1].imm = ext->ksym.addr >> 32;
|
|
}
|
|
}
|
|
break;
|
|
case RELO_EXTERN_FUNC:
|
|
ext = &obj->externs[relo->sym_off];
|
|
insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL;
|
|
if (ext->is_set) {
|
|
insn[0].imm = ext->ksym.kernel_btf_id;
|
|
insn[0].off = ext->ksym.btf_fd_idx;
|
|
} else { /* unresolved weak kfunc */
|
|
insn[0].imm = 0;
|
|
insn[0].off = 0;
|
|
}
|
|
break;
|
|
case RELO_SUBPROG_ADDR:
|
|
if (insn[0].src_reg != BPF_PSEUDO_FUNC) {
|
|
pr_warn("prog '%s': relo #%d: bad insn\n",
|
|
prog->name, i);
|
|
return -EINVAL;
|
|
}
|
|
/* handled already */
|
|
break;
|
|
case RELO_CALL:
|
|
/* handled already */
|
|
break;
|
|
case RELO_CORE:
|
|
/* will be handled by bpf_program_record_relos() */
|
|
break;
|
|
default:
|
|
pr_warn("prog '%s': relo #%d: bad relo type %d\n",
|
|
prog->name, i, relo->type);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int adjust_prog_btf_ext_info(const struct bpf_object *obj,
|
|
const struct bpf_program *prog,
|
|
const struct btf_ext_info *ext_info,
|
|
void **prog_info, __u32 *prog_rec_cnt,
|
|
__u32 *prog_rec_sz)
|
|
{
|
|
void *copy_start = NULL, *copy_end = NULL;
|
|
void *rec, *rec_end, *new_prog_info;
|
|
const struct btf_ext_info_sec *sec;
|
|
size_t old_sz, new_sz;
|
|
int i, sec_num, sec_idx, off_adj;
|
|
|
|
sec_num = 0;
|
|
for_each_btf_ext_sec(ext_info, sec) {
|
|
sec_idx = ext_info->sec_idxs[sec_num];
|
|
sec_num++;
|
|
if (prog->sec_idx != sec_idx)
|
|
continue;
|
|
|
|
for_each_btf_ext_rec(ext_info, sec, i, rec) {
|
|
__u32 insn_off = *(__u32 *)rec / BPF_INSN_SZ;
|
|
|
|
if (insn_off < prog->sec_insn_off)
|
|
continue;
|
|
if (insn_off >= prog->sec_insn_off + prog->sec_insn_cnt)
|
|
break;
|
|
|
|
if (!copy_start)
|
|
copy_start = rec;
|
|
copy_end = rec + ext_info->rec_size;
|
|
}
|
|
|
|
if (!copy_start)
|
|
return -ENOENT;
|
|
|
|
/* append func/line info of a given (sub-)program to the main
|
|
* program func/line info
|
|
*/
|
|
old_sz = (size_t)(*prog_rec_cnt) * ext_info->rec_size;
|
|
new_sz = old_sz + (copy_end - copy_start);
|
|
new_prog_info = realloc(*prog_info, new_sz);
|
|
if (!new_prog_info)
|
|
return -ENOMEM;
|
|
*prog_info = new_prog_info;
|
|
*prog_rec_cnt = new_sz / ext_info->rec_size;
|
|
memcpy(new_prog_info + old_sz, copy_start, copy_end - copy_start);
|
|
|
|
/* Kernel instruction offsets are in units of 8-byte
|
|
* instructions, while .BTF.ext instruction offsets generated
|
|
* by Clang are in units of bytes. So convert Clang offsets
|
|
* into kernel offsets and adjust offset according to program
|
|
* relocated position.
|
|
*/
|
|
off_adj = prog->sub_insn_off - prog->sec_insn_off;
|
|
rec = new_prog_info + old_sz;
|
|
rec_end = new_prog_info + new_sz;
|
|
for (; rec < rec_end; rec += ext_info->rec_size) {
|
|
__u32 *insn_off = rec;
|
|
|
|
*insn_off = *insn_off / BPF_INSN_SZ + off_adj;
|
|
}
|
|
*prog_rec_sz = ext_info->rec_size;
|
|
return 0;
|
|
}
|
|
|
|
return -ENOENT;
|
|
}
|
|
|
|
static int
|
|
reloc_prog_func_and_line_info(const struct bpf_object *obj,
|
|
struct bpf_program *main_prog,
|
|
const struct bpf_program *prog)
|
|
{
|
|
int err;
|
|
|
|
/* no .BTF.ext relocation if .BTF.ext is missing or kernel doesn't
|
|
* supprot func/line info
|
|
*/
|
|
if (!obj->btf_ext || !kernel_supports(obj, FEAT_BTF_FUNC))
|
|
return 0;
|
|
|
|
/* only attempt func info relocation if main program's func_info
|
|
* relocation was successful
|
|
*/
|
|
if (main_prog != prog && !main_prog->func_info)
|
|
goto line_info;
|
|
|
|
err = adjust_prog_btf_ext_info(obj, prog, &obj->btf_ext->func_info,
|
|
&main_prog->func_info,
|
|
&main_prog->func_info_cnt,
|
|
&main_prog->func_info_rec_size);
|
|
if (err) {
|
|
if (err != -ENOENT) {
|
|
pr_warn("prog '%s': error relocating .BTF.ext function info: %d\n",
|
|
prog->name, err);
|
|
return err;
|
|
}
|
|
if (main_prog->func_info) {
|
|
/*
|
|
* Some info has already been found but has problem
|
|
* in the last btf_ext reloc. Must have to error out.
|
|
*/
|
|
pr_warn("prog '%s': missing .BTF.ext function info.\n", prog->name);
|
|
return err;
|
|
}
|
|
/* Have problem loading the very first info. Ignore the rest. */
|
|
pr_warn("prog '%s': missing .BTF.ext function info for the main program, skipping all of .BTF.ext func info.\n",
|
|
prog->name);
|
|
}
|
|
|
|
line_info:
|
|
/* don't relocate line info if main program's relocation failed */
|
|
if (main_prog != prog && !main_prog->line_info)
|
|
return 0;
|
|
|
|
err = adjust_prog_btf_ext_info(obj, prog, &obj->btf_ext->line_info,
|
|
&main_prog->line_info,
|
|
&main_prog->line_info_cnt,
|
|
&main_prog->line_info_rec_size);
|
|
if (err) {
|
|
if (err != -ENOENT) {
|
|
pr_warn("prog '%s': error relocating .BTF.ext line info: %d\n",
|
|
prog->name, err);
|
|
return err;
|
|
}
|
|
if (main_prog->line_info) {
|
|
/*
|
|
* Some info has already been found but has problem
|
|
* in the last btf_ext reloc. Must have to error out.
|
|
*/
|
|
pr_warn("prog '%s': missing .BTF.ext line info.\n", prog->name);
|
|
return err;
|
|
}
|
|
/* Have problem loading the very first info. Ignore the rest. */
|
|
pr_warn("prog '%s': missing .BTF.ext line info for the main program, skipping all of .BTF.ext line info.\n",
|
|
prog->name);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int cmp_relo_by_insn_idx(const void *key, const void *elem)
|
|
{
|
|
size_t insn_idx = *(const size_t *)key;
|
|
const struct reloc_desc *relo = elem;
|
|
|
|
if (insn_idx == relo->insn_idx)
|
|
return 0;
|
|
return insn_idx < relo->insn_idx ? -1 : 1;
|
|
}
|
|
|
|
static struct reloc_desc *find_prog_insn_relo(const struct bpf_program *prog, size_t insn_idx)
|
|
{
|
|
if (!prog->nr_reloc)
|
|
return NULL;
|
|
return bsearch(&insn_idx, prog->reloc_desc, prog->nr_reloc,
|
|
sizeof(*prog->reloc_desc), cmp_relo_by_insn_idx);
|
|
}
|
|
|
|
static int append_subprog_relos(struct bpf_program *main_prog, struct bpf_program *subprog)
|
|
{
|
|
int new_cnt = main_prog->nr_reloc + subprog->nr_reloc;
|
|
struct reloc_desc *relos;
|
|
int i;
|
|
|
|
if (main_prog == subprog)
|
|
return 0;
|
|
relos = libbpf_reallocarray(main_prog->reloc_desc, new_cnt, sizeof(*relos));
|
|
if (!relos)
|
|
return -ENOMEM;
|
|
if (subprog->nr_reloc)
|
|
memcpy(relos + main_prog->nr_reloc, subprog->reloc_desc,
|
|
sizeof(*relos) * subprog->nr_reloc);
|
|
|
|
for (i = main_prog->nr_reloc; i < new_cnt; i++)
|
|
relos[i].insn_idx += subprog->sub_insn_off;
|
|
/* After insn_idx adjustment the 'relos' array is still sorted
|
|
* by insn_idx and doesn't break bsearch.
|
|
*/
|
|
main_prog->reloc_desc = relos;
|
|
main_prog->nr_reloc = new_cnt;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_object__reloc_code(struct bpf_object *obj, struct bpf_program *main_prog,
|
|
struct bpf_program *prog)
|
|
{
|
|
size_t sub_insn_idx, insn_idx, new_cnt;
|
|
struct bpf_program *subprog;
|
|
struct bpf_insn *insns, *insn;
|
|
struct reloc_desc *relo;
|
|
int err;
|
|
|
|
err = reloc_prog_func_and_line_info(obj, main_prog, prog);
|
|
if (err)
|
|
return err;
|
|
|
|
for (insn_idx = 0; insn_idx < prog->sec_insn_cnt; insn_idx++) {
|
|
insn = &main_prog->insns[prog->sub_insn_off + insn_idx];
|
|
if (!insn_is_subprog_call(insn) && !insn_is_pseudo_func(insn))
|
|
continue;
|
|
|
|
relo = find_prog_insn_relo(prog, insn_idx);
|
|
if (relo && relo->type == RELO_EXTERN_FUNC)
|
|
/* kfunc relocations will be handled later
|
|
* in bpf_object__relocate_data()
|
|
*/
|
|
continue;
|
|
if (relo && relo->type != RELO_CALL && relo->type != RELO_SUBPROG_ADDR) {
|
|
pr_warn("prog '%s': unexpected relo for insn #%zu, type %d\n",
|
|
prog->name, insn_idx, relo->type);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
if (relo) {
|
|
/* sub-program instruction index is a combination of
|
|
* an offset of a symbol pointed to by relocation and
|
|
* call instruction's imm field; for global functions,
|
|
* call always has imm = -1, but for static functions
|
|
* relocation is against STT_SECTION and insn->imm
|
|
* points to a start of a static function
|
|
*
|
|
* for subprog addr relocation, the relo->sym_off + insn->imm is
|
|
* the byte offset in the corresponding section.
|
|
*/
|
|
if (relo->type == RELO_CALL)
|
|
sub_insn_idx = relo->sym_off / BPF_INSN_SZ + insn->imm + 1;
|
|
else
|
|
sub_insn_idx = (relo->sym_off + insn->imm) / BPF_INSN_SZ;
|
|
} else if (insn_is_pseudo_func(insn)) {
|
|
/*
|
|
* RELO_SUBPROG_ADDR relo is always emitted even if both
|
|
* functions are in the same section, so it shouldn't reach here.
|
|
*/
|
|
pr_warn("prog '%s': missing subprog addr relo for insn #%zu\n",
|
|
prog->name, insn_idx);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
} else {
|
|
/* if subprogram call is to a static function within
|
|
* the same ELF section, there won't be any relocation
|
|
* emitted, but it also means there is no additional
|
|
* offset necessary, insns->imm is relative to
|
|
* instruction's original position within the section
|
|
*/
|
|
sub_insn_idx = prog->sec_insn_off + insn_idx + insn->imm + 1;
|
|
}
|
|
|
|
/* we enforce that sub-programs should be in .text section */
|
|
subprog = find_prog_by_sec_insn(obj, obj->efile.text_shndx, sub_insn_idx);
|
|
if (!subprog) {
|
|
pr_warn("prog '%s': no .text section found yet sub-program call exists\n",
|
|
prog->name);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
|
|
/* if it's the first call instruction calling into this
|
|
* subprogram (meaning this subprog hasn't been processed
|
|
* yet) within the context of current main program:
|
|
* - append it at the end of main program's instructions blog;
|
|
* - process is recursively, while current program is put on hold;
|
|
* - if that subprogram calls some other not yet processes
|
|
* subprogram, same thing will happen recursively until
|
|
* there are no more unprocesses subprograms left to append
|
|
* and relocate.
|
|
*/
|
|
if (subprog->sub_insn_off == 0) {
|
|
subprog->sub_insn_off = main_prog->insns_cnt;
|
|
|
|
new_cnt = main_prog->insns_cnt + subprog->insns_cnt;
|
|
insns = libbpf_reallocarray(main_prog->insns, new_cnt, sizeof(*insns));
|
|
if (!insns) {
|
|
pr_warn("prog '%s': failed to realloc prog code\n", main_prog->name);
|
|
return -ENOMEM;
|
|
}
|
|
main_prog->insns = insns;
|
|
main_prog->insns_cnt = new_cnt;
|
|
|
|
memcpy(main_prog->insns + subprog->sub_insn_off, subprog->insns,
|
|
subprog->insns_cnt * sizeof(*insns));
|
|
|
|
pr_debug("prog '%s': added %zu insns from sub-prog '%s'\n",
|
|
main_prog->name, subprog->insns_cnt, subprog->name);
|
|
|
|
/* The subprog insns are now appended. Append its relos too. */
|
|
err = append_subprog_relos(main_prog, subprog);
|
|
if (err)
|
|
return err;
|
|
err = bpf_object__reloc_code(obj, main_prog, subprog);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
/* main_prog->insns memory could have been re-allocated, so
|
|
* calculate pointer again
|
|
*/
|
|
insn = &main_prog->insns[prog->sub_insn_off + insn_idx];
|
|
/* calculate correct instruction position within current main
|
|
* prog; each main prog can have a different set of
|
|
* subprograms appended (potentially in different order as
|
|
* well), so position of any subprog can be different for
|
|
* different main programs */
|
|
insn->imm = subprog->sub_insn_off - (prog->sub_insn_off + insn_idx) - 1;
|
|
|
|
pr_debug("prog '%s': insn #%zu relocated, imm %d points to subprog '%s' (now at %zu offset)\n",
|
|
prog->name, insn_idx, insn->imm, subprog->name, subprog->sub_insn_off);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Relocate sub-program calls.
|
|
*
|
|
* Algorithm operates as follows. Each entry-point BPF program (referred to as
|
|
* main prog) is processed separately. For each subprog (non-entry functions,
|
|
* that can be called from either entry progs or other subprogs) gets their
|
|
* sub_insn_off reset to zero. This serves as indicator that this subprogram
|
|
* hasn't been yet appended and relocated within current main prog. Once its
|
|
* relocated, sub_insn_off will point at the position within current main prog
|
|
* where given subprog was appended. This will further be used to relocate all
|
|
* the call instructions jumping into this subprog.
|
|
*
|
|
* We start with main program and process all call instructions. If the call
|
|
* is into a subprog that hasn't been processed (i.e., subprog->sub_insn_off
|
|
* is zero), subprog instructions are appended at the end of main program's
|
|
* instruction array. Then main program is "put on hold" while we recursively
|
|
* process newly appended subprogram. If that subprogram calls into another
|
|
* subprogram that hasn't been appended, new subprogram is appended again to
|
|
* the *main* prog's instructions (subprog's instructions are always left
|
|
* untouched, as they need to be in unmodified state for subsequent main progs
|
|
* and subprog instructions are always sent only as part of a main prog) and
|
|
* the process continues recursively. Once all the subprogs called from a main
|
|
* prog or any of its subprogs are appended (and relocated), all their
|
|
* positions within finalized instructions array are known, so it's easy to
|
|
* rewrite call instructions with correct relative offsets, corresponding to
|
|
* desired target subprog.
|
|
*
|
|
* Its important to realize that some subprogs might not be called from some
|
|
* main prog and any of its called/used subprogs. Those will keep their
|
|
* subprog->sub_insn_off as zero at all times and won't be appended to current
|
|
* main prog and won't be relocated within the context of current main prog.
|
|
* They might still be used from other main progs later.
|
|
*
|
|
* Visually this process can be shown as below. Suppose we have two main
|
|
* programs mainA and mainB and BPF object contains three subprogs: subA,
|
|
* subB, and subC. mainA calls only subA, mainB calls only subC, but subA and
|
|
* subC both call subB:
|
|
*
|
|
* +--------+ +-------+
|
|
* | v v |
|
|
* +--+---+ +--+-+-+ +---+--+
|
|
* | subA | | subB | | subC |
|
|
* +--+---+ +------+ +---+--+
|
|
* ^ ^
|
|
* | |
|
|
* +---+-------+ +------+----+
|
|
* | mainA | | mainB |
|
|
* +-----------+ +-----------+
|
|
*
|
|
* We'll start relocating mainA, will find subA, append it and start
|
|
* processing sub A recursively:
|
|
*
|
|
* +-----------+------+
|
|
* | mainA | subA |
|
|
* +-----------+------+
|
|
*
|
|
* At this point we notice that subB is used from subA, so we append it and
|
|
* relocate (there are no further subcalls from subB):
|
|
*
|
|
* +-----------+------+------+
|
|
* | mainA | subA | subB |
|
|
* +-----------+------+------+
|
|
*
|
|
* At this point, we relocate subA calls, then go one level up and finish with
|
|
* relocatin mainA calls. mainA is done.
|
|
*
|
|
* For mainB process is similar but results in different order. We start with
|
|
* mainB and skip subA and subB, as mainB never calls them (at least
|
|
* directly), but we see subC is needed, so we append and start processing it:
|
|
*
|
|
* +-----------+------+
|
|
* | mainB | subC |
|
|
* +-----------+------+
|
|
* Now we see subC needs subB, so we go back to it, append and relocate it:
|
|
*
|
|
* +-----------+------+------+
|
|
* | mainB | subC | subB |
|
|
* +-----------+------+------+
|
|
*
|
|
* At this point we unwind recursion, relocate calls in subC, then in mainB.
|
|
*/
|
|
static int
|
|
bpf_object__relocate_calls(struct bpf_object *obj, struct bpf_program *prog)
|
|
{
|
|
struct bpf_program *subprog;
|
|
int i, err;
|
|
|
|
/* mark all subprogs as not relocated (yet) within the context of
|
|
* current main program
|
|
*/
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
subprog = &obj->programs[i];
|
|
if (!prog_is_subprog(obj, subprog))
|
|
continue;
|
|
|
|
subprog->sub_insn_off = 0;
|
|
}
|
|
|
|
err = bpf_object__reloc_code(obj, prog, prog);
|
|
if (err)
|
|
return err;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
bpf_object__free_relocs(struct bpf_object *obj)
|
|
{
|
|
struct bpf_program *prog;
|
|
int i;
|
|
|
|
/* free up relocation descriptors */
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
prog = &obj->programs[i];
|
|
zfree(&prog->reloc_desc);
|
|
prog->nr_reloc = 0;
|
|
}
|
|
}
|
|
|
|
static int cmp_relocs(const void *_a, const void *_b)
|
|
{
|
|
const struct reloc_desc *a = _a;
|
|
const struct reloc_desc *b = _b;
|
|
|
|
if (a->insn_idx != b->insn_idx)
|
|
return a->insn_idx < b->insn_idx ? -1 : 1;
|
|
|
|
/* no two relocations should have the same insn_idx, but ... */
|
|
if (a->type != b->type)
|
|
return a->type < b->type ? -1 : 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void bpf_object__sort_relos(struct bpf_object *obj)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
struct bpf_program *p = &obj->programs[i];
|
|
|
|
if (!p->nr_reloc)
|
|
continue;
|
|
|
|
qsort(p->reloc_desc, p->nr_reloc, sizeof(*p->reloc_desc), cmp_relocs);
|
|
}
|
|
}
|
|
|
|
static int
|
|
bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path)
|
|
{
|
|
struct bpf_program *prog;
|
|
size_t i, j;
|
|
int err;
|
|
|
|
if (obj->btf_ext) {
|
|
err = bpf_object__relocate_core(obj, targ_btf_path);
|
|
if (err) {
|
|
pr_warn("failed to perform CO-RE relocations: %d\n",
|
|
err);
|
|
return err;
|
|
}
|
|
bpf_object__sort_relos(obj);
|
|
}
|
|
|
|
/* Before relocating calls pre-process relocations and mark
|
|
* few ld_imm64 instructions that points to subprogs.
|
|
* Otherwise bpf_object__reloc_code() later would have to consider
|
|
* all ld_imm64 insns as relocation candidates. That would
|
|
* reduce relocation speed, since amount of find_prog_insn_relo()
|
|
* would increase and most of them will fail to find a relo.
|
|
*/
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
prog = &obj->programs[i];
|
|
for (j = 0; j < prog->nr_reloc; j++) {
|
|
struct reloc_desc *relo = &prog->reloc_desc[j];
|
|
struct bpf_insn *insn = &prog->insns[relo->insn_idx];
|
|
|
|
/* mark the insn, so it's recognized by insn_is_pseudo_func() */
|
|
if (relo->type == RELO_SUBPROG_ADDR)
|
|
insn[0].src_reg = BPF_PSEUDO_FUNC;
|
|
}
|
|
}
|
|
|
|
/* relocate subprogram calls and append used subprograms to main
|
|
* programs; each copy of subprogram code needs to be relocated
|
|
* differently for each main program, because its code location might
|
|
* have changed.
|
|
* Append subprog relos to main programs to allow data relos to be
|
|
* processed after text is completely relocated.
|
|
*/
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
prog = &obj->programs[i];
|
|
/* sub-program's sub-calls are relocated within the context of
|
|
* its main program only
|
|
*/
|
|
if (prog_is_subprog(obj, prog))
|
|
continue;
|
|
if (!prog->autoload)
|
|
continue;
|
|
|
|
err = bpf_object__relocate_calls(obj, prog);
|
|
if (err) {
|
|
pr_warn("prog '%s': failed to relocate calls: %d\n",
|
|
prog->name, err);
|
|
return err;
|
|
}
|
|
}
|
|
/* Process data relos for main programs */
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
prog = &obj->programs[i];
|
|
if (prog_is_subprog(obj, prog))
|
|
continue;
|
|
if (!prog->autoload)
|
|
continue;
|
|
err = bpf_object__relocate_data(obj, prog);
|
|
if (err) {
|
|
pr_warn("prog '%s': failed to relocate data references: %d\n",
|
|
prog->name, err);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
|
|
Elf64_Shdr *shdr, Elf_Data *data);
|
|
|
|
static int bpf_object__collect_map_relos(struct bpf_object *obj,
|
|
Elf64_Shdr *shdr, Elf_Data *data)
|
|
{
|
|
const int bpf_ptr_sz = 8, host_ptr_sz = sizeof(void *);
|
|
int i, j, nrels, new_sz;
|
|
const struct btf_var_secinfo *vi = NULL;
|
|
const struct btf_type *sec, *var, *def;
|
|
struct bpf_map *map = NULL, *targ_map = NULL;
|
|
struct bpf_program *targ_prog = NULL;
|
|
bool is_prog_array, is_map_in_map;
|
|
const struct btf_member *member;
|
|
const char *name, *mname, *type;
|
|
unsigned int moff;
|
|
Elf64_Sym *sym;
|
|
Elf64_Rel *rel;
|
|
void *tmp;
|
|
|
|
if (!obj->efile.btf_maps_sec_btf_id || !obj->btf)
|
|
return -EINVAL;
|
|
sec = btf__type_by_id(obj->btf, obj->efile.btf_maps_sec_btf_id);
|
|
if (!sec)
|
|
return -EINVAL;
|
|
|
|
nrels = shdr->sh_size / shdr->sh_entsize;
|
|
for (i = 0; i < nrels; i++) {
|
|
rel = elf_rel_by_idx(data, i);
|
|
if (!rel) {
|
|
pr_warn(".maps relo #%d: failed to get ELF relo\n", i);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
sym = elf_sym_by_idx(obj, ELF64_R_SYM(rel->r_info));
|
|
if (!sym) {
|
|
pr_warn(".maps relo #%d: symbol %zx not found\n",
|
|
i, (size_t)ELF64_R_SYM(rel->r_info));
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
name = elf_sym_str(obj, sym->st_name) ?: "<?>";
|
|
|
|
pr_debug(".maps relo #%d: for %zd value %zd rel->r_offset %zu name %d ('%s')\n",
|
|
i, (ssize_t)(rel->r_info >> 32), (size_t)sym->st_value,
|
|
(size_t)rel->r_offset, sym->st_name, name);
|
|
|
|
for (j = 0; j < obj->nr_maps; j++) {
|
|
map = &obj->maps[j];
|
|
if (map->sec_idx != obj->efile.btf_maps_shndx)
|
|
continue;
|
|
|
|
vi = btf_var_secinfos(sec) + map->btf_var_idx;
|
|
if (vi->offset <= rel->r_offset &&
|
|
rel->r_offset + bpf_ptr_sz <= vi->offset + vi->size)
|
|
break;
|
|
}
|
|
if (j == obj->nr_maps) {
|
|
pr_warn(".maps relo #%d: cannot find map '%s' at rel->r_offset %zu\n",
|
|
i, name, (size_t)rel->r_offset);
|
|
return -EINVAL;
|
|
}
|
|
|
|
is_map_in_map = bpf_map_type__is_map_in_map(map->def.type);
|
|
is_prog_array = map->def.type == BPF_MAP_TYPE_PROG_ARRAY;
|
|
type = is_map_in_map ? "map" : "prog";
|
|
if (is_map_in_map) {
|
|
if (sym->st_shndx != obj->efile.btf_maps_shndx) {
|
|
pr_warn(".maps relo #%d: '%s' isn't a BTF-defined map\n",
|
|
i, name);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
if (map->def.type == BPF_MAP_TYPE_HASH_OF_MAPS &&
|
|
map->def.key_size != sizeof(int)) {
|
|
pr_warn(".maps relo #%d: hash-of-maps '%s' should have key size %zu.\n",
|
|
i, map->name, sizeof(int));
|
|
return -EINVAL;
|
|
}
|
|
targ_map = bpf_object__find_map_by_name(obj, name);
|
|
if (!targ_map) {
|
|
pr_warn(".maps relo #%d: '%s' isn't a valid map reference\n",
|
|
i, name);
|
|
return -ESRCH;
|
|
}
|
|
} else if (is_prog_array) {
|
|
targ_prog = bpf_object__find_program_by_name(obj, name);
|
|
if (!targ_prog) {
|
|
pr_warn(".maps relo #%d: '%s' isn't a valid program reference\n",
|
|
i, name);
|
|
return -ESRCH;
|
|
}
|
|
if (targ_prog->sec_idx != sym->st_shndx ||
|
|
targ_prog->sec_insn_off * 8 != sym->st_value ||
|
|
prog_is_subprog(obj, targ_prog)) {
|
|
pr_warn(".maps relo #%d: '%s' isn't an entry-point program\n",
|
|
i, name);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
} else {
|
|
return -EINVAL;
|
|
}
|
|
|
|
var = btf__type_by_id(obj->btf, vi->type);
|
|
def = skip_mods_and_typedefs(obj->btf, var->type, NULL);
|
|
if (btf_vlen(def) == 0)
|
|
return -EINVAL;
|
|
member = btf_members(def) + btf_vlen(def) - 1;
|
|
mname = btf__name_by_offset(obj->btf, member->name_off);
|
|
if (strcmp(mname, "values"))
|
|
return -EINVAL;
|
|
|
|
moff = btf_member_bit_offset(def, btf_vlen(def) - 1) / 8;
|
|
if (rel->r_offset - vi->offset < moff)
|
|
return -EINVAL;
|
|
|
|
moff = rel->r_offset - vi->offset - moff;
|
|
/* here we use BPF pointer size, which is always 64 bit, as we
|
|
* are parsing ELF that was built for BPF target
|
|
*/
|
|
if (moff % bpf_ptr_sz)
|
|
return -EINVAL;
|
|
moff /= bpf_ptr_sz;
|
|
if (moff >= map->init_slots_sz) {
|
|
new_sz = moff + 1;
|
|
tmp = libbpf_reallocarray(map->init_slots, new_sz, host_ptr_sz);
|
|
if (!tmp)
|
|
return -ENOMEM;
|
|
map->init_slots = tmp;
|
|
memset(map->init_slots + map->init_slots_sz, 0,
|
|
(new_sz - map->init_slots_sz) * host_ptr_sz);
|
|
map->init_slots_sz = new_sz;
|
|
}
|
|
map->init_slots[moff] = is_map_in_map ? (void *)targ_map : (void *)targ_prog;
|
|
|
|
pr_debug(".maps relo #%d: map '%s' slot [%d] points to %s '%s'\n",
|
|
i, map->name, moff, type, name);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__collect_relos(struct bpf_object *obj)
|
|
{
|
|
int i, err;
|
|
|
|
for (i = 0; i < obj->efile.sec_cnt; i++) {
|
|
struct elf_sec_desc *sec_desc = &obj->efile.secs[i];
|
|
Elf64_Shdr *shdr;
|
|
Elf_Data *data;
|
|
int idx;
|
|
|
|
if (sec_desc->sec_type != SEC_RELO)
|
|
continue;
|
|
|
|
shdr = sec_desc->shdr;
|
|
data = sec_desc->data;
|
|
idx = shdr->sh_info;
|
|
|
|
if (shdr->sh_type != SHT_REL) {
|
|
pr_warn("internal error at %d\n", __LINE__);
|
|
return -LIBBPF_ERRNO__INTERNAL;
|
|
}
|
|
|
|
if (idx == obj->efile.st_ops_shndx)
|
|
err = bpf_object__collect_st_ops_relos(obj, shdr, data);
|
|
else if (idx == obj->efile.btf_maps_shndx)
|
|
err = bpf_object__collect_map_relos(obj, shdr, data);
|
|
else
|
|
err = bpf_object__collect_prog_relos(obj, shdr, data);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
bpf_object__sort_relos(obj);
|
|
return 0;
|
|
}
|
|
|
|
static bool insn_is_helper_call(struct bpf_insn *insn, enum bpf_func_id *func_id)
|
|
{
|
|
if (BPF_CLASS(insn->code) == BPF_JMP &&
|
|
BPF_OP(insn->code) == BPF_CALL &&
|
|
BPF_SRC(insn->code) == BPF_K &&
|
|
insn->src_reg == 0 &&
|
|
insn->dst_reg == 0) {
|
|
*func_id = insn->imm;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static int bpf_object__sanitize_prog(struct bpf_object *obj, struct bpf_program *prog)
|
|
{
|
|
struct bpf_insn *insn = prog->insns;
|
|
enum bpf_func_id func_id;
|
|
int i;
|
|
|
|
if (obj->gen_loader)
|
|
return 0;
|
|
|
|
for (i = 0; i < prog->insns_cnt; i++, insn++) {
|
|
if (!insn_is_helper_call(insn, &func_id))
|
|
continue;
|
|
|
|
/* on kernels that don't yet support
|
|
* bpf_probe_read_{kernel,user}[_str] helpers, fall back
|
|
* to bpf_probe_read() which works well for old kernels
|
|
*/
|
|
switch (func_id) {
|
|
case BPF_FUNC_probe_read_kernel:
|
|
case BPF_FUNC_probe_read_user:
|
|
if (!kernel_supports(obj, FEAT_PROBE_READ_KERN))
|
|
insn->imm = BPF_FUNC_probe_read;
|
|
break;
|
|
case BPF_FUNC_probe_read_kernel_str:
|
|
case BPF_FUNC_probe_read_user_str:
|
|
if (!kernel_supports(obj, FEAT_PROBE_READ_KERN))
|
|
insn->imm = BPF_FUNC_probe_read_str;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attach_name,
|
|
int *btf_obj_fd, int *btf_type_id);
|
|
|
|
/* this is called as prog->sec_def->prog_prepare_load_fn for libbpf-supported sec_defs */
|
|
static int libbpf_prepare_prog_load(struct bpf_program *prog,
|
|
struct bpf_prog_load_opts *opts, long cookie)
|
|
{
|
|
enum sec_def_flags def = cookie;
|
|
|
|
/* old kernels might not support specifying expected_attach_type */
|
|
if ((def & SEC_EXP_ATTACH_OPT) && !kernel_supports(prog->obj, FEAT_EXP_ATTACH_TYPE))
|
|
opts->expected_attach_type = 0;
|
|
|
|
if (def & SEC_SLEEPABLE)
|
|
opts->prog_flags |= BPF_F_SLEEPABLE;
|
|
|
|
if (prog->type == BPF_PROG_TYPE_XDP && (def & SEC_XDP_FRAGS))
|
|
opts->prog_flags |= BPF_F_XDP_HAS_FRAGS;
|
|
|
|
if (def & SEC_DEPRECATED) {
|
|
pr_warn("SEC(\"%s\") is deprecated, please see https://github.com/libbpf/libbpf/wiki/Libbpf-1.0-migration-guide#bpf-program-sec-annotation-deprecations for details\n",
|
|
prog->sec_name);
|
|
}
|
|
|
|
if ((def & SEC_ATTACH_BTF) && !prog->attach_btf_id) {
|
|
int btf_obj_fd = 0, btf_type_id = 0, err;
|
|
const char *attach_name;
|
|
|
|
attach_name = strchr(prog->sec_name, '/');
|
|
if (!attach_name) {
|
|
/* if BPF program is annotated with just SEC("fentry")
|
|
* (or similar) without declaratively specifying
|
|
* target, then it is expected that target will be
|
|
* specified with bpf_program__set_attach_target() at
|
|
* runtime before BPF object load step. If not, then
|
|
* there is nothing to load into the kernel as BPF
|
|
* verifier won't be able to validate BPF program
|
|
* correctness anyways.
|
|
*/
|
|
pr_warn("prog '%s': no BTF-based attach target is specified, use bpf_program__set_attach_target()\n",
|
|
prog->name);
|
|
return -EINVAL;
|
|
}
|
|
attach_name++; /* skip over / */
|
|
|
|
err = libbpf_find_attach_btf_id(prog, attach_name, &btf_obj_fd, &btf_type_id);
|
|
if (err)
|
|
return err;
|
|
|
|
/* cache resolved BTF FD and BTF type ID in the prog */
|
|
prog->attach_btf_obj_fd = btf_obj_fd;
|
|
prog->attach_btf_id = btf_type_id;
|
|
|
|
/* but by now libbpf common logic is not utilizing
|
|
* prog->atach_btf_obj_fd/prog->attach_btf_id anymore because
|
|
* this callback is called after opts were populated by
|
|
* libbpf, so this callback has to update opts explicitly here
|
|
*/
|
|
opts->attach_btf_obj_fd = btf_obj_fd;
|
|
opts->attach_btf_id = btf_type_id;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void fixup_verifier_log(struct bpf_program *prog, char *buf, size_t buf_sz);
|
|
|
|
static int bpf_object_load_prog_instance(struct bpf_object *obj, struct bpf_program *prog,
|
|
struct bpf_insn *insns, int insns_cnt,
|
|
const char *license, __u32 kern_version,
|
|
int *prog_fd)
|
|
{
|
|
LIBBPF_OPTS(bpf_prog_load_opts, load_attr);
|
|
const char *prog_name = NULL;
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
size_t log_buf_size = 0;
|
|
char *log_buf = NULL, *tmp;
|
|
int btf_fd, ret, err;
|
|
bool own_log_buf = true;
|
|
__u32 log_level = prog->log_level;
|
|
|
|
if (prog->type == BPF_PROG_TYPE_UNSPEC) {
|
|
/*
|
|
* The program type must be set. Most likely we couldn't find a proper
|
|
* section definition at load time, and thus we didn't infer the type.
|
|
*/
|
|
pr_warn("prog '%s': missing BPF prog type, check ELF section name '%s'\n",
|
|
prog->name, prog->sec_name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!insns || !insns_cnt)
|
|
return -EINVAL;
|
|
|
|
load_attr.expected_attach_type = prog->expected_attach_type;
|
|
if (kernel_supports(obj, FEAT_PROG_NAME))
|
|
prog_name = prog->name;
|
|
load_attr.attach_prog_fd = prog->attach_prog_fd;
|
|
load_attr.attach_btf_obj_fd = prog->attach_btf_obj_fd;
|
|
load_attr.attach_btf_id = prog->attach_btf_id;
|
|
load_attr.kern_version = kern_version;
|
|
load_attr.prog_ifindex = prog->prog_ifindex;
|
|
|
|
/* specify func_info/line_info only if kernel supports them */
|
|
btf_fd = bpf_object__btf_fd(obj);
|
|
if (btf_fd >= 0 && kernel_supports(obj, FEAT_BTF_FUNC)) {
|
|
load_attr.prog_btf_fd = btf_fd;
|
|
load_attr.func_info = prog->func_info;
|
|
load_attr.func_info_rec_size = prog->func_info_rec_size;
|
|
load_attr.func_info_cnt = prog->func_info_cnt;
|
|
load_attr.line_info = prog->line_info;
|
|
load_attr.line_info_rec_size = prog->line_info_rec_size;
|
|
load_attr.line_info_cnt = prog->line_info_cnt;
|
|
}
|
|
load_attr.log_level = log_level;
|
|
load_attr.prog_flags = prog->prog_flags;
|
|
load_attr.fd_array = obj->fd_array;
|
|
|
|
/* adjust load_attr if sec_def provides custom preload callback */
|
|
if (prog->sec_def && prog->sec_def->prog_prepare_load_fn) {
|
|
err = prog->sec_def->prog_prepare_load_fn(prog, &load_attr, prog->sec_def->cookie);
|
|
if (err < 0) {
|
|
pr_warn("prog '%s': failed to prepare load attributes: %d\n",
|
|
prog->name, err);
|
|
return err;
|
|
}
|
|
insns = prog->insns;
|
|
insns_cnt = prog->insns_cnt;
|
|
}
|
|
|
|
if (obj->gen_loader) {
|
|
bpf_gen__prog_load(obj->gen_loader, prog->type, prog->name,
|
|
license, insns, insns_cnt, &load_attr,
|
|
prog - obj->programs);
|
|
*prog_fd = -1;
|
|
return 0;
|
|
}
|
|
|
|
retry_load:
|
|
/* if log_level is zero, we don't request logs initially even if
|
|
* custom log_buf is specified; if the program load fails, then we'll
|
|
* bump log_level to 1 and use either custom log_buf or we'll allocate
|
|
* our own and retry the load to get details on what failed
|
|
*/
|
|
if (log_level) {
|
|
if (prog->log_buf) {
|
|
log_buf = prog->log_buf;
|
|
log_buf_size = prog->log_size;
|
|
own_log_buf = false;
|
|
} else if (obj->log_buf) {
|
|
log_buf = obj->log_buf;
|
|
log_buf_size = obj->log_size;
|
|
own_log_buf = false;
|
|
} else {
|
|
log_buf_size = max((size_t)BPF_LOG_BUF_SIZE, log_buf_size * 2);
|
|
tmp = realloc(log_buf, log_buf_size);
|
|
if (!tmp) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
log_buf = tmp;
|
|
log_buf[0] = '\0';
|
|
own_log_buf = true;
|
|
}
|
|
}
|
|
|
|
load_attr.log_buf = log_buf;
|
|
load_attr.log_size = log_buf_size;
|
|
load_attr.log_level = log_level;
|
|
|
|
ret = bpf_prog_load(prog->type, prog_name, license, insns, insns_cnt, &load_attr);
|
|
if (ret >= 0) {
|
|
if (log_level && own_log_buf) {
|
|
pr_debug("prog '%s': -- BEGIN PROG LOAD LOG --\n%s-- END PROG LOAD LOG --\n",
|
|
prog->name, log_buf);
|
|
}
|
|
|
|
if (obj->has_rodata && kernel_supports(obj, FEAT_PROG_BIND_MAP)) {
|
|
struct bpf_map *map;
|
|
int i;
|
|
|
|
for (i = 0; i < obj->nr_maps; i++) {
|
|
map = &prog->obj->maps[i];
|
|
if (map->libbpf_type != LIBBPF_MAP_RODATA)
|
|
continue;
|
|
|
|
if (bpf_prog_bind_map(ret, bpf_map__fd(map), NULL)) {
|
|
cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
|
|
pr_warn("prog '%s': failed to bind map '%s': %s\n",
|
|
prog->name, map->real_name, cp);
|
|
/* Don't fail hard if can't bind rodata. */
|
|
}
|
|
}
|
|
}
|
|
|
|
*prog_fd = ret;
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
if (log_level == 0) {
|
|
log_level = 1;
|
|
goto retry_load;
|
|
}
|
|
/* On ENOSPC, increase log buffer size and retry, unless custom
|
|
* log_buf is specified.
|
|
* Be careful to not overflow u32, though. Kernel's log buf size limit
|
|
* isn't part of UAPI so it can always be bumped to full 4GB. So don't
|
|
* multiply by 2 unless we are sure we'll fit within 32 bits.
|
|
* Currently, we'll get -EINVAL when we reach (UINT_MAX >> 2).
|
|
*/
|
|
if (own_log_buf && errno == ENOSPC && log_buf_size <= UINT_MAX / 2)
|
|
goto retry_load;
|
|
|
|
ret = -errno;
|
|
|
|
/* post-process verifier log to improve error descriptions */
|
|
fixup_verifier_log(prog, log_buf, log_buf_size);
|
|
|
|
cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
|
|
pr_warn("prog '%s': BPF program load failed: %s\n", prog->name, cp);
|
|
pr_perm_msg(ret);
|
|
|
|
if (own_log_buf && log_buf && log_buf[0] != '\0') {
|
|
pr_warn("prog '%s': -- BEGIN PROG LOAD LOG --\n%s-- END PROG LOAD LOG --\n",
|
|
prog->name, log_buf);
|
|
}
|
|
|
|
out:
|
|
if (own_log_buf)
|
|
free(log_buf);
|
|
return ret;
|
|
}
|
|
|
|
static char *find_prev_line(char *buf, char *cur)
|
|
{
|
|
char *p;
|
|
|
|
if (cur == buf) /* end of a log buf */
|
|
return NULL;
|
|
|
|
p = cur - 1;
|
|
while (p - 1 >= buf && *(p - 1) != '\n')
|
|
p--;
|
|
|
|
return p;
|
|
}
|
|
|
|
static void patch_log(char *buf, size_t buf_sz, size_t log_sz,
|
|
char *orig, size_t orig_sz, const char *patch)
|
|
{
|
|
/* size of the remaining log content to the right from the to-be-replaced part */
|
|
size_t rem_sz = (buf + log_sz) - (orig + orig_sz);
|
|
size_t patch_sz = strlen(patch);
|
|
|
|
if (patch_sz != orig_sz) {
|
|
/* If patch line(s) are longer than original piece of verifier log,
|
|
* shift log contents by (patch_sz - orig_sz) bytes to the right
|
|
* starting from after to-be-replaced part of the log.
|
|
*
|
|
* If patch line(s) are shorter than original piece of verifier log,
|
|
* shift log contents by (orig_sz - patch_sz) bytes to the left
|
|
* starting from after to-be-replaced part of the log
|
|
*
|
|
* We need to be careful about not overflowing available
|
|
* buf_sz capacity. If that's the case, we'll truncate the end
|
|
* of the original log, as necessary.
|
|
*/
|
|
if (patch_sz > orig_sz) {
|
|
if (orig + patch_sz >= buf + buf_sz) {
|
|
/* patch is big enough to cover remaining space completely */
|
|
patch_sz -= (orig + patch_sz) - (buf + buf_sz) + 1;
|
|
rem_sz = 0;
|
|
} else if (patch_sz - orig_sz > buf_sz - log_sz) {
|
|
/* patch causes part of remaining log to be truncated */
|
|
rem_sz -= (patch_sz - orig_sz) - (buf_sz - log_sz);
|
|
}
|
|
}
|
|
/* shift remaining log to the right by calculated amount */
|
|
memmove(orig + patch_sz, orig + orig_sz, rem_sz);
|
|
}
|
|
|
|
memcpy(orig, patch, patch_sz);
|
|
}
|
|
|
|
static void fixup_log_failed_core_relo(struct bpf_program *prog,
|
|
char *buf, size_t buf_sz, size_t log_sz,
|
|
char *line1, char *line2, char *line3)
|
|
{
|
|
/* Expected log for failed and not properly guarded CO-RE relocation:
|
|
* line1 -> 123: (85) call unknown#195896080
|
|
* line2 -> invalid func unknown#195896080
|
|
* line3 -> <anything else or end of buffer>
|
|
*
|
|
* "123" is the index of the instruction that was poisoned. We extract
|
|
* instruction index to find corresponding CO-RE relocation and
|
|
* replace this part of the log with more relevant information about
|
|
* failed CO-RE relocation.
|
|
*/
|
|
const struct bpf_core_relo *relo;
|
|
struct bpf_core_spec spec;
|
|
char patch[512], spec_buf[256];
|
|
int insn_idx, err, spec_len;
|
|
|
|
if (sscanf(line1, "%d: (%*d) call unknown#195896080\n", &insn_idx) != 1)
|
|
return;
|
|
|
|
relo = find_relo_core(prog, insn_idx);
|
|
if (!relo)
|
|
return;
|
|
|
|
err = bpf_core_parse_spec(prog->name, prog->obj->btf, relo, &spec);
|
|
if (err)
|
|
return;
|
|
|
|
spec_len = bpf_core_format_spec(spec_buf, sizeof(spec_buf), &spec);
|
|
snprintf(patch, sizeof(patch),
|
|
"%d: <invalid CO-RE relocation>\n"
|
|
"failed to resolve CO-RE relocation %s%s\n",
|
|
insn_idx, spec_buf, spec_len >= sizeof(spec_buf) ? "..." : "");
|
|
|
|
patch_log(buf, buf_sz, log_sz, line1, line3 - line1, patch);
|
|
}
|
|
|
|
static void fixup_log_missing_map_load(struct bpf_program *prog,
|
|
char *buf, size_t buf_sz, size_t log_sz,
|
|
char *line1, char *line2, char *line3)
|
|
{
|
|
/* Expected log for failed and not properly guarded CO-RE relocation:
|
|
* line1 -> 123: (85) call unknown#2001000345
|
|
* line2 -> invalid func unknown#2001000345
|
|
* line3 -> <anything else or end of buffer>
|
|
*
|
|
* "123" is the index of the instruction that was poisoned.
|
|
* "345" in "2001000345" are map index in obj->maps to fetch map name.
|
|
*/
|
|
struct bpf_object *obj = prog->obj;
|
|
const struct bpf_map *map;
|
|
int insn_idx, map_idx;
|
|
char patch[128];
|
|
|
|
if (sscanf(line1, "%d: (%*d) call unknown#%d\n", &insn_idx, &map_idx) != 2)
|
|
return;
|
|
|
|
map_idx -= MAP_LDIMM64_POISON_BASE;
|
|
if (map_idx < 0 || map_idx >= obj->nr_maps)
|
|
return;
|
|
map = &obj->maps[map_idx];
|
|
|
|
snprintf(patch, sizeof(patch),
|
|
"%d: <invalid BPF map reference>\n"
|
|
"BPF map '%s' is referenced but wasn't created\n",
|
|
insn_idx, map->name);
|
|
|
|
patch_log(buf, buf_sz, log_sz, line1, line3 - line1, patch);
|
|
}
|
|
|
|
static void fixup_verifier_log(struct bpf_program *prog, char *buf, size_t buf_sz)
|
|
{
|
|
/* look for familiar error patterns in last N lines of the log */
|
|
const size_t max_last_line_cnt = 10;
|
|
char *prev_line, *cur_line, *next_line;
|
|
size_t log_sz;
|
|
int i;
|
|
|
|
if (!buf)
|
|
return;
|
|
|
|
log_sz = strlen(buf) + 1;
|
|
next_line = buf + log_sz - 1;
|
|
|
|
for (i = 0; i < max_last_line_cnt; i++, next_line = cur_line) {
|
|
cur_line = find_prev_line(buf, next_line);
|
|
if (!cur_line)
|
|
return;
|
|
|
|
/* failed CO-RE relocation case */
|
|
if (str_has_pfx(cur_line, "invalid func unknown#195896080\n")) {
|
|
prev_line = find_prev_line(buf, cur_line);
|
|
if (!prev_line)
|
|
continue;
|
|
|
|
fixup_log_failed_core_relo(prog, buf, buf_sz, log_sz,
|
|
prev_line, cur_line, next_line);
|
|
return;
|
|
} else if (str_has_pfx(cur_line, "invalid func unknown#"MAP_LDIMM64_POISON_PFX)) {
|
|
prev_line = find_prev_line(buf, cur_line);
|
|
if (!prev_line)
|
|
continue;
|
|
|
|
fixup_log_missing_map_load(prog, buf, buf_sz, log_sz,
|
|
prev_line, cur_line, next_line);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int bpf_program_record_relos(struct bpf_program *prog)
|
|
{
|
|
struct bpf_object *obj = prog->obj;
|
|
int i;
|
|
|
|
for (i = 0; i < prog->nr_reloc; i++) {
|
|
struct reloc_desc *relo = &prog->reloc_desc[i];
|
|
struct extern_desc *ext = &obj->externs[relo->sym_off];
|
|
|
|
switch (relo->type) {
|
|
case RELO_EXTERN_VAR:
|
|
if (ext->type != EXT_KSYM)
|
|
continue;
|
|
bpf_gen__record_extern(obj->gen_loader, ext->name,
|
|
ext->is_weak, !ext->ksym.type_id,
|
|
BTF_KIND_VAR, relo->insn_idx);
|
|
break;
|
|
case RELO_EXTERN_FUNC:
|
|
bpf_gen__record_extern(obj->gen_loader, ext->name,
|
|
ext->is_weak, false, BTF_KIND_FUNC,
|
|
relo->insn_idx);
|
|
break;
|
|
case RELO_CORE: {
|
|
struct bpf_core_relo cr = {
|
|
.insn_off = relo->insn_idx * 8,
|
|
.type_id = relo->core_relo->type_id,
|
|
.access_str_off = relo->core_relo->access_str_off,
|
|
.kind = relo->core_relo->kind,
|
|
};
|
|
|
|
bpf_gen__record_relo_core(obj->gen_loader, &cr);
|
|
break;
|
|
}
|
|
default:
|
|
continue;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object_load_prog(struct bpf_object *obj, struct bpf_program *prog,
|
|
const char *license, __u32 kern_ver)
|
|
{
|
|
int err = 0, fd, i;
|
|
|
|
if (obj->loaded) {
|
|
pr_warn("prog '%s': can't load after object was loaded\n", prog->name);
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
if (prog->instances.nr < 0 || !prog->instances.fds) {
|
|
if (prog->preprocessor) {
|
|
pr_warn("Internal error: can't load program '%s'\n",
|
|
prog->name);
|
|
return libbpf_err(-LIBBPF_ERRNO__INTERNAL);
|
|
}
|
|
|
|
prog->instances.fds = malloc(sizeof(int));
|
|
if (!prog->instances.fds) {
|
|
pr_warn("Not enough memory for BPF fds\n");
|
|
return libbpf_err(-ENOMEM);
|
|
}
|
|
prog->instances.nr = 1;
|
|
prog->instances.fds[0] = -1;
|
|
}
|
|
|
|
if (!prog->preprocessor) {
|
|
if (prog->instances.nr != 1) {
|
|
pr_warn("prog '%s': inconsistent nr(%d) != 1\n",
|
|
prog->name, prog->instances.nr);
|
|
}
|
|
if (obj->gen_loader)
|
|
bpf_program_record_relos(prog);
|
|
err = bpf_object_load_prog_instance(obj, prog,
|
|
prog->insns, prog->insns_cnt,
|
|
license, kern_ver, &fd);
|
|
if (!err)
|
|
prog->instances.fds[0] = fd;
|
|
goto out;
|
|
}
|
|
|
|
for (i = 0; i < prog->instances.nr; i++) {
|
|
struct bpf_prog_prep_result result;
|
|
bpf_program_prep_t preprocessor = prog->preprocessor;
|
|
|
|
memset(&result, 0, sizeof(result));
|
|
err = preprocessor(prog, i, prog->insns,
|
|
prog->insns_cnt, &result);
|
|
if (err) {
|
|
pr_warn("Preprocessing the %dth instance of program '%s' failed\n",
|
|
i, prog->name);
|
|
goto out;
|
|
}
|
|
|
|
if (!result.new_insn_ptr || !result.new_insn_cnt) {
|
|
pr_debug("Skip loading the %dth instance of program '%s'\n",
|
|
i, prog->name);
|
|
prog->instances.fds[i] = -1;
|
|
if (result.pfd)
|
|
*result.pfd = -1;
|
|
continue;
|
|
}
|
|
|
|
err = bpf_object_load_prog_instance(obj, prog,
|
|
result.new_insn_ptr, result.new_insn_cnt,
|
|
license, kern_ver, &fd);
|
|
if (err) {
|
|
pr_warn("Loading the %dth instance of program '%s' failed\n",
|
|
i, prog->name);
|
|
goto out;
|
|
}
|
|
|
|
if (result.pfd)
|
|
*result.pfd = fd;
|
|
prog->instances.fds[i] = fd;
|
|
}
|
|
out:
|
|
if (err)
|
|
pr_warn("failed to load program '%s'\n", prog->name);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
int bpf_program__load(struct bpf_program *prog, const char *license, __u32 kern_ver)
|
|
{
|
|
return bpf_object_load_prog(prog->obj, prog, license, kern_ver);
|
|
}
|
|
|
|
static int
|
|
bpf_object__load_progs(struct bpf_object *obj, int log_level)
|
|
{
|
|
struct bpf_program *prog;
|
|
size_t i;
|
|
int err;
|
|
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
prog = &obj->programs[i];
|
|
err = bpf_object__sanitize_prog(obj, prog);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
prog = &obj->programs[i];
|
|
if (prog_is_subprog(obj, prog))
|
|
continue;
|
|
if (!prog->autoload) {
|
|
pr_debug("prog '%s': skipped loading\n", prog->name);
|
|
continue;
|
|
}
|
|
prog->log_level |= log_level;
|
|
err = bpf_object_load_prog(obj, prog, obj->license, obj->kern_version);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
bpf_object__free_relocs(obj);
|
|
return 0;
|
|
}
|
|
|
|
static const struct bpf_sec_def *find_sec_def(const char *sec_name);
|
|
|
|
static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object_open_opts *opts)
|
|
{
|
|
struct bpf_program *prog;
|
|
int err;
|
|
|
|
bpf_object__for_each_program(prog, obj) {
|
|
prog->sec_def = find_sec_def(prog->sec_name);
|
|
if (!prog->sec_def) {
|
|
/* couldn't guess, but user might manually specify */
|
|
pr_debug("prog '%s': unrecognized ELF section name '%s'\n",
|
|
prog->name, prog->sec_name);
|
|
continue;
|
|
}
|
|
|
|
prog->type = prog->sec_def->prog_type;
|
|
prog->expected_attach_type = prog->sec_def->expected_attach_type;
|
|
|
|
#pragma GCC diagnostic push
|
|
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
|
|
if (prog->sec_def->prog_type == BPF_PROG_TYPE_TRACING ||
|
|
prog->sec_def->prog_type == BPF_PROG_TYPE_EXT)
|
|
prog->attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0);
|
|
#pragma GCC diagnostic pop
|
|
|
|
/* sec_def can have custom callback which should be called
|
|
* after bpf_program is initialized to adjust its properties
|
|
*/
|
|
if (prog->sec_def->prog_setup_fn) {
|
|
err = prog->sec_def->prog_setup_fn(prog, prog->sec_def->cookie);
|
|
if (err < 0) {
|
|
pr_warn("prog '%s': failed to initialize: %d\n",
|
|
prog->name, err);
|
|
return err;
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct bpf_object *bpf_object_open(const char *path, const void *obj_buf, size_t obj_buf_sz,
|
|
const struct bpf_object_open_opts *opts)
|
|
{
|
|
const char *obj_name, *kconfig, *btf_tmp_path;
|
|
struct bpf_object *obj;
|
|
char tmp_name[64];
|
|
int err;
|
|
char *log_buf;
|
|
size_t log_size;
|
|
__u32 log_level;
|
|
|
|
if (elf_version(EV_CURRENT) == EV_NONE) {
|
|
pr_warn("failed to init libelf for %s\n",
|
|
path ? : "(mem buf)");
|
|
return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
|
|
}
|
|
|
|
if (!OPTS_VALID(opts, bpf_object_open_opts))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
obj_name = OPTS_GET(opts, object_name, NULL);
|
|
if (obj_buf) {
|
|
if (!obj_name) {
|
|
snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
|
|
(unsigned long)obj_buf,
|
|
(unsigned long)obj_buf_sz);
|
|
obj_name = tmp_name;
|
|
}
|
|
path = obj_name;
|
|
pr_debug("loading object '%s' from buffer\n", obj_name);
|
|
}
|
|
|
|
log_buf = OPTS_GET(opts, kernel_log_buf, NULL);
|
|
log_size = OPTS_GET(opts, kernel_log_size, 0);
|
|
log_level = OPTS_GET(opts, kernel_log_level, 0);
|
|
if (log_size > UINT_MAX)
|
|
return ERR_PTR(-EINVAL);
|
|
if (log_size && !log_buf)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
obj = bpf_object__new(path, obj_buf, obj_buf_sz, obj_name);
|
|
if (IS_ERR(obj))
|
|
return obj;
|
|
|
|
obj->log_buf = log_buf;
|
|
obj->log_size = log_size;
|
|
obj->log_level = log_level;
|
|
|
|
btf_tmp_path = OPTS_GET(opts, btf_custom_path, NULL);
|
|
if (btf_tmp_path) {
|
|
if (strlen(btf_tmp_path) >= PATH_MAX) {
|
|
err = -ENAMETOOLONG;
|
|
goto out;
|
|
}
|
|
obj->btf_custom_path = strdup(btf_tmp_path);
|
|
if (!obj->btf_custom_path) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
kconfig = OPTS_GET(opts, kconfig, NULL);
|
|
if (kconfig) {
|
|
obj->kconfig = strdup(kconfig);
|
|
if (!obj->kconfig) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
err = bpf_object__elf_init(obj);
|
|
err = err ? : bpf_object__check_endianness(obj);
|
|
err = err ? : bpf_object__elf_collect(obj);
|
|
err = err ? : bpf_object__collect_externs(obj);
|
|
err = err ? : bpf_object__finalize_btf(obj);
|
|
err = err ? : bpf_object__init_maps(obj, opts);
|
|
err = err ? : bpf_object_init_progs(obj, opts);
|
|
err = err ? : bpf_object__collect_relos(obj);
|
|
if (err)
|
|
goto out;
|
|
|
|
bpf_object__elf_finish(obj);
|
|
|
|
return obj;
|
|
out:
|
|
bpf_object__close(obj);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static struct bpf_object *
|
|
__bpf_object__open_xattr(struct bpf_object_open_attr *attr, int flags)
|
|
{
|
|
DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
|
|
.relaxed_maps = flags & MAPS_RELAX_COMPAT,
|
|
);
|
|
|
|
/* param validation */
|
|
if (!attr->file)
|
|
return NULL;
|
|
|
|
pr_debug("loading %s\n", attr->file);
|
|
return bpf_object_open(attr->file, NULL, 0, &opts);
|
|
}
|
|
|
|
struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr)
|
|
{
|
|
return libbpf_ptr(__bpf_object__open_xattr(attr, 0));
|
|
}
|
|
|
|
struct bpf_object *bpf_object__open(const char *path)
|
|
{
|
|
struct bpf_object_open_attr attr = {
|
|
.file = path,
|
|
.prog_type = BPF_PROG_TYPE_UNSPEC,
|
|
};
|
|
|
|
return libbpf_ptr(__bpf_object__open_xattr(&attr, 0));
|
|
}
|
|
|
|
struct bpf_object *
|
|
bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts)
|
|
{
|
|
if (!path)
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
pr_debug("loading %s\n", path);
|
|
|
|
return libbpf_ptr(bpf_object_open(path, NULL, 0, opts));
|
|
}
|
|
|
|
struct bpf_object *
|
|
bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
|
|
const struct bpf_object_open_opts *opts)
|
|
{
|
|
if (!obj_buf || obj_buf_sz == 0)
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
return libbpf_ptr(bpf_object_open(NULL, obj_buf, obj_buf_sz, opts));
|
|
}
|
|
|
|
struct bpf_object *
|
|
bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
|
|
const char *name)
|
|
{
|
|
DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
|
|
.object_name = name,
|
|
/* wrong default, but backwards-compatible */
|
|
.relaxed_maps = true,
|
|
);
|
|
|
|
/* returning NULL is wrong, but backwards-compatible */
|
|
if (!obj_buf || obj_buf_sz == 0)
|
|
return errno = EINVAL, NULL;
|
|
|
|
return libbpf_ptr(bpf_object_open(NULL, obj_buf, obj_buf_sz, &opts));
|
|
}
|
|
|
|
static int bpf_object_unload(struct bpf_object *obj)
|
|
{
|
|
size_t i;
|
|
|
|
if (!obj)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
for (i = 0; i < obj->nr_maps; i++) {
|
|
zclose(obj->maps[i].fd);
|
|
if (obj->maps[i].st_ops)
|
|
zfree(&obj->maps[i].st_ops->kern_vdata);
|
|
}
|
|
|
|
for (i = 0; i < obj->nr_programs; i++)
|
|
bpf_program__unload(&obj->programs[i]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bpf_object__unload(struct bpf_object *obj) __attribute__((alias("bpf_object_unload")));
|
|
|
|
static int bpf_object__sanitize_maps(struct bpf_object *obj)
|
|
{
|
|
struct bpf_map *m;
|
|
|
|
bpf_object__for_each_map(m, obj) {
|
|
if (!bpf_map__is_internal(m))
|
|
continue;
|
|
if (!kernel_supports(obj, FEAT_ARRAY_MMAP))
|
|
m->def.map_flags ^= BPF_F_MMAPABLE;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int libbpf_kallsyms_parse(kallsyms_cb_t cb, void *ctx)
|
|
{
|
|
char sym_type, sym_name[500];
|
|
unsigned long long sym_addr;
|
|
int ret, err = 0;
|
|
FILE *f;
|
|
|
|
f = fopen("/proc/kallsyms", "r");
|
|
if (!f) {
|
|
err = -errno;
|
|
pr_warn("failed to open /proc/kallsyms: %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
while (true) {
|
|
ret = fscanf(f, "%llx %c %499s%*[^\n]\n",
|
|
&sym_addr, &sym_type, sym_name);
|
|
if (ret == EOF && feof(f))
|
|
break;
|
|
if (ret != 3) {
|
|
pr_warn("failed to read kallsyms entry: %d\n", ret);
|
|
err = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
err = cb(sym_addr, sym_type, sym_name, ctx);
|
|
if (err)
|
|
break;
|
|
}
|
|
|
|
fclose(f);
|
|
return err;
|
|
}
|
|
|
|
static int kallsyms_cb(unsigned long long sym_addr, char sym_type,
|
|
const char *sym_name, void *ctx)
|
|
{
|
|
struct bpf_object *obj = ctx;
|
|
const struct btf_type *t;
|
|
struct extern_desc *ext;
|
|
|
|
ext = find_extern_by_name(obj, sym_name);
|
|
if (!ext || ext->type != EXT_KSYM)
|
|
return 0;
|
|
|
|
t = btf__type_by_id(obj->btf, ext->btf_id);
|
|
if (!btf_is_var(t))
|
|
return 0;
|
|
|
|
if (ext->is_set && ext->ksym.addr != sym_addr) {
|
|
pr_warn("extern (ksym) '%s' resolution is ambiguous: 0x%llx or 0x%llx\n",
|
|
sym_name, ext->ksym.addr, sym_addr);
|
|
return -EINVAL;
|
|
}
|
|
if (!ext->is_set) {
|
|
ext->is_set = true;
|
|
ext->ksym.addr = sym_addr;
|
|
pr_debug("extern (ksym) %s=0x%llx\n", sym_name, sym_addr);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__read_kallsyms_file(struct bpf_object *obj)
|
|
{
|
|
return libbpf_kallsyms_parse(kallsyms_cb, obj);
|
|
}
|
|
|
|
static int find_ksym_btf_id(struct bpf_object *obj, const char *ksym_name,
|
|
__u16 kind, struct btf **res_btf,
|
|
struct module_btf **res_mod_btf)
|
|
{
|
|
struct module_btf *mod_btf;
|
|
struct btf *btf;
|
|
int i, id, err;
|
|
|
|
btf = obj->btf_vmlinux;
|
|
mod_btf = NULL;
|
|
id = btf__find_by_name_kind(btf, ksym_name, kind);
|
|
|
|
if (id == -ENOENT) {
|
|
err = load_module_btfs(obj);
|
|
if (err)
|
|
return err;
|
|
|
|
for (i = 0; i < obj->btf_module_cnt; i++) {
|
|
/* we assume module_btf's BTF FD is always >0 */
|
|
mod_btf = &obj->btf_modules[i];
|
|
btf = mod_btf->btf;
|
|
id = btf__find_by_name_kind_own(btf, ksym_name, kind);
|
|
if (id != -ENOENT)
|
|
break;
|
|
}
|
|
}
|
|
if (id <= 0)
|
|
return -ESRCH;
|
|
|
|
*res_btf = btf;
|
|
*res_mod_btf = mod_btf;
|
|
return id;
|
|
}
|
|
|
|
static int bpf_object__resolve_ksym_var_btf_id(struct bpf_object *obj,
|
|
struct extern_desc *ext)
|
|
{
|
|
const struct btf_type *targ_var, *targ_type;
|
|
__u32 targ_type_id, local_type_id;
|
|
struct module_btf *mod_btf = NULL;
|
|
const char *targ_var_name;
|
|
struct btf *btf = NULL;
|
|
int id, err;
|
|
|
|
id = find_ksym_btf_id(obj, ext->name, BTF_KIND_VAR, &btf, &mod_btf);
|
|
if (id < 0) {
|
|
if (id == -ESRCH && ext->is_weak)
|
|
return 0;
|
|
pr_warn("extern (var ksym) '%s': not found in kernel BTF\n",
|
|
ext->name);
|
|
return id;
|
|
}
|
|
|
|
/* find local type_id */
|
|
local_type_id = ext->ksym.type_id;
|
|
|
|
/* find target type_id */
|
|
targ_var = btf__type_by_id(btf, id);
|
|
targ_var_name = btf__name_by_offset(btf, targ_var->name_off);
|
|
targ_type = skip_mods_and_typedefs(btf, targ_var->type, &targ_type_id);
|
|
|
|
err = bpf_core_types_are_compat(obj->btf, local_type_id,
|
|
btf, targ_type_id);
|
|
if (err <= 0) {
|
|
const struct btf_type *local_type;
|
|
const char *targ_name, *local_name;
|
|
|
|
local_type = btf__type_by_id(obj->btf, local_type_id);
|
|
local_name = btf__name_by_offset(obj->btf, local_type->name_off);
|
|
targ_name = btf__name_by_offset(btf, targ_type->name_off);
|
|
|
|
pr_warn("extern (var ksym) '%s': incompatible types, expected [%d] %s %s, but kernel has [%d] %s %s\n",
|
|
ext->name, local_type_id,
|
|
btf_kind_str(local_type), local_name, targ_type_id,
|
|
btf_kind_str(targ_type), targ_name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
ext->is_set = true;
|
|
ext->ksym.kernel_btf_obj_fd = mod_btf ? mod_btf->fd : 0;
|
|
ext->ksym.kernel_btf_id = id;
|
|
pr_debug("extern (var ksym) '%s': resolved to [%d] %s %s\n",
|
|
ext->name, id, btf_kind_str(targ_var), targ_var_name);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__resolve_ksym_func_btf_id(struct bpf_object *obj,
|
|
struct extern_desc *ext)
|
|
{
|
|
int local_func_proto_id, kfunc_proto_id, kfunc_id;
|
|
struct module_btf *mod_btf = NULL;
|
|
const struct btf_type *kern_func;
|
|
struct btf *kern_btf = NULL;
|
|
int ret;
|
|
|
|
local_func_proto_id = ext->ksym.type_id;
|
|
|
|
kfunc_id = find_ksym_btf_id(obj, ext->name, BTF_KIND_FUNC, &kern_btf, &mod_btf);
|
|
if (kfunc_id < 0) {
|
|
if (kfunc_id == -ESRCH && ext->is_weak)
|
|
return 0;
|
|
pr_warn("extern (func ksym) '%s': not found in kernel or module BTFs\n",
|
|
ext->name);
|
|
return kfunc_id;
|
|
}
|
|
|
|
kern_func = btf__type_by_id(kern_btf, kfunc_id);
|
|
kfunc_proto_id = kern_func->type;
|
|
|
|
ret = bpf_core_types_are_compat(obj->btf, local_func_proto_id,
|
|
kern_btf, kfunc_proto_id);
|
|
if (ret <= 0) {
|
|
pr_warn("extern (func ksym) '%s': func_proto [%d] incompatible with kernel [%d]\n",
|
|
ext->name, local_func_proto_id, kfunc_proto_id);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* set index for module BTF fd in fd_array, if unset */
|
|
if (mod_btf && !mod_btf->fd_array_idx) {
|
|
/* insn->off is s16 */
|
|
if (obj->fd_array_cnt == INT16_MAX) {
|
|
pr_warn("extern (func ksym) '%s': module BTF fd index %d too big to fit in bpf_insn offset\n",
|
|
ext->name, mod_btf->fd_array_idx);
|
|
return -E2BIG;
|
|
}
|
|
/* Cannot use index 0 for module BTF fd */
|
|
if (!obj->fd_array_cnt)
|
|
obj->fd_array_cnt = 1;
|
|
|
|
ret = libbpf_ensure_mem((void **)&obj->fd_array, &obj->fd_array_cap, sizeof(int),
|
|
obj->fd_array_cnt + 1);
|
|
if (ret)
|
|
return ret;
|
|
mod_btf->fd_array_idx = obj->fd_array_cnt;
|
|
/* we assume module BTF FD is always >0 */
|
|
obj->fd_array[obj->fd_array_cnt++] = mod_btf->fd;
|
|
}
|
|
|
|
ext->is_set = true;
|
|
ext->ksym.kernel_btf_id = kfunc_id;
|
|
ext->ksym.btf_fd_idx = mod_btf ? mod_btf->fd_array_idx : 0;
|
|
pr_debug("extern (func ksym) '%s': resolved to kernel [%d]\n",
|
|
ext->name, kfunc_id);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__resolve_ksyms_btf_id(struct bpf_object *obj)
|
|
{
|
|
const struct btf_type *t;
|
|
struct extern_desc *ext;
|
|
int i, err;
|
|
|
|
for (i = 0; i < obj->nr_extern; i++) {
|
|
ext = &obj->externs[i];
|
|
if (ext->type != EXT_KSYM || !ext->ksym.type_id)
|
|
continue;
|
|
|
|
if (obj->gen_loader) {
|
|
ext->is_set = true;
|
|
ext->ksym.kernel_btf_obj_fd = 0;
|
|
ext->ksym.kernel_btf_id = 0;
|
|
continue;
|
|
}
|
|
t = btf__type_by_id(obj->btf, ext->btf_id);
|
|
if (btf_is_var(t))
|
|
err = bpf_object__resolve_ksym_var_btf_id(obj, ext);
|
|
else
|
|
err = bpf_object__resolve_ksym_func_btf_id(obj, ext);
|
|
if (err)
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__resolve_externs(struct bpf_object *obj,
|
|
const char *extra_kconfig)
|
|
{
|
|
bool need_config = false, need_kallsyms = false;
|
|
bool need_vmlinux_btf = false;
|
|
struct extern_desc *ext;
|
|
void *kcfg_data = NULL;
|
|
int err, i;
|
|
|
|
if (obj->nr_extern == 0)
|
|
return 0;
|
|
|
|
if (obj->kconfig_map_idx >= 0)
|
|
kcfg_data = obj->maps[obj->kconfig_map_idx].mmaped;
|
|
|
|
for (i = 0; i < obj->nr_extern; i++) {
|
|
ext = &obj->externs[i];
|
|
|
|
if (ext->type == EXT_KCFG &&
|
|
strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) {
|
|
void *ext_val = kcfg_data + ext->kcfg.data_off;
|
|
__u32 kver = get_kernel_version();
|
|
|
|
if (!kver) {
|
|
pr_warn("failed to get kernel version\n");
|
|
return -EINVAL;
|
|
}
|
|
err = set_kcfg_value_num(ext, ext_val, kver);
|
|
if (err)
|
|
return err;
|
|
pr_debug("extern (kcfg) %s=0x%x\n", ext->name, kver);
|
|
} else if (ext->type == EXT_KCFG && str_has_pfx(ext->name, "CONFIG_")) {
|
|
need_config = true;
|
|
} else if (ext->type == EXT_KSYM) {
|
|
if (ext->ksym.type_id)
|
|
need_vmlinux_btf = true;
|
|
else
|
|
need_kallsyms = true;
|
|
} else {
|
|
pr_warn("unrecognized extern '%s'\n", ext->name);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
if (need_config && extra_kconfig) {
|
|
err = bpf_object__read_kconfig_mem(obj, extra_kconfig, kcfg_data);
|
|
if (err)
|
|
return -EINVAL;
|
|
need_config = false;
|
|
for (i = 0; i < obj->nr_extern; i++) {
|
|
ext = &obj->externs[i];
|
|
if (ext->type == EXT_KCFG && !ext->is_set) {
|
|
need_config = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (need_config) {
|
|
err = bpf_object__read_kconfig_file(obj, kcfg_data);
|
|
if (err)
|
|
return -EINVAL;
|
|
}
|
|
if (need_kallsyms) {
|
|
err = bpf_object__read_kallsyms_file(obj);
|
|
if (err)
|
|
return -EINVAL;
|
|
}
|
|
if (need_vmlinux_btf) {
|
|
err = bpf_object__resolve_ksyms_btf_id(obj);
|
|
if (err)
|
|
return -EINVAL;
|
|
}
|
|
for (i = 0; i < obj->nr_extern; i++) {
|
|
ext = &obj->externs[i];
|
|
|
|
if (!ext->is_set && !ext->is_weak) {
|
|
pr_warn("extern %s (strong) not resolved\n", ext->name);
|
|
return -ESRCH;
|
|
} else if (!ext->is_set) {
|
|
pr_debug("extern %s (weak) not resolved, defaulting to zero\n",
|
|
ext->name);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object_load(struct bpf_object *obj, int extra_log_level, const char *target_btf_path)
|
|
{
|
|
int err, i;
|
|
|
|
if (!obj)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
if (obj->loaded) {
|
|
pr_warn("object '%s': load can't be attempted twice\n", obj->name);
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
if (obj->gen_loader)
|
|
bpf_gen__init(obj->gen_loader, extra_log_level, obj->nr_programs, obj->nr_maps);
|
|
|
|
err = bpf_object__probe_loading(obj);
|
|
err = err ? : bpf_object__load_vmlinux_btf(obj, false);
|
|
err = err ? : bpf_object__resolve_externs(obj, obj->kconfig);
|
|
err = err ? : bpf_object__sanitize_and_load_btf(obj);
|
|
err = err ? : bpf_object__sanitize_maps(obj);
|
|
err = err ? : bpf_object__init_kern_struct_ops_maps(obj);
|
|
err = err ? : bpf_object__create_maps(obj);
|
|
err = err ? : bpf_object__relocate(obj, obj->btf_custom_path ? : target_btf_path);
|
|
err = err ? : bpf_object__load_progs(obj, extra_log_level);
|
|
err = err ? : bpf_object_init_prog_arrays(obj);
|
|
|
|
if (obj->gen_loader) {
|
|
/* reset FDs */
|
|
if (obj->btf)
|
|
btf__set_fd(obj->btf, -1);
|
|
for (i = 0; i < obj->nr_maps; i++)
|
|
obj->maps[i].fd = -1;
|
|
if (!err)
|
|
err = bpf_gen__finish(obj->gen_loader, obj->nr_programs, obj->nr_maps);
|
|
}
|
|
|
|
/* clean up fd_array */
|
|
zfree(&obj->fd_array);
|
|
|
|
/* clean up module BTFs */
|
|
for (i = 0; i < obj->btf_module_cnt; i++) {
|
|
close(obj->btf_modules[i].fd);
|
|
btf__free(obj->btf_modules[i].btf);
|
|
free(obj->btf_modules[i].name);
|
|
}
|
|
free(obj->btf_modules);
|
|
|
|
/* clean up vmlinux BTF */
|
|
btf__free(obj->btf_vmlinux);
|
|
obj->btf_vmlinux = NULL;
|
|
|
|
obj->loaded = true; /* doesn't matter if successfully or not */
|
|
|
|
if (err)
|
|
goto out;
|
|
|
|
return 0;
|
|
out:
|
|
/* unpin any maps that were auto-pinned during load */
|
|
for (i = 0; i < obj->nr_maps; i++)
|
|
if (obj->maps[i].pinned && !obj->maps[i].reused)
|
|
bpf_map__unpin(&obj->maps[i], NULL);
|
|
|
|
bpf_object_unload(obj);
|
|
pr_warn("failed to load object '%s'\n", obj->path);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
int bpf_object__load_xattr(struct bpf_object_load_attr *attr)
|
|
{
|
|
return bpf_object_load(attr->obj, attr->log_level, attr->target_btf_path);
|
|
}
|
|
|
|
int bpf_object__load(struct bpf_object *obj)
|
|
{
|
|
return bpf_object_load(obj, 0, NULL);
|
|
}
|
|
|
|
static int make_parent_dir(const char *path)
|
|
{
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
char *dname, *dir;
|
|
int err = 0;
|
|
|
|
dname = strdup(path);
|
|
if (dname == NULL)
|
|
return -ENOMEM;
|
|
|
|
dir = dirname(dname);
|
|
if (mkdir(dir, 0700) && errno != EEXIST)
|
|
err = -errno;
|
|
|
|
free(dname);
|
|
if (err) {
|
|
cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg));
|
|
pr_warn("failed to mkdir %s: %s\n", path, cp);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int check_path(const char *path)
|
|
{
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
struct statfs st_fs;
|
|
char *dname, *dir;
|
|
int err = 0;
|
|
|
|
if (path == NULL)
|
|
return -EINVAL;
|
|
|
|
dname = strdup(path);
|
|
if (dname == NULL)
|
|
return -ENOMEM;
|
|
|
|
dir = dirname(dname);
|
|
if (statfs(dir, &st_fs)) {
|
|
cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
|
|
pr_warn("failed to statfs %s: %s\n", dir, cp);
|
|
err = -errno;
|
|
}
|
|
free(dname);
|
|
|
|
if (!err && st_fs.f_type != BPF_FS_MAGIC) {
|
|
pr_warn("specified path %s is not on BPF FS\n", path);
|
|
err = -EINVAL;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int bpf_program_pin_instance(struct bpf_program *prog, const char *path, int instance)
|
|
{
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
int err;
|
|
|
|
err = make_parent_dir(path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
err = check_path(path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
if (prog == NULL) {
|
|
pr_warn("invalid program pointer\n");
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
if (instance < 0 || instance >= prog->instances.nr) {
|
|
pr_warn("invalid prog instance %d of prog %s (max %d)\n",
|
|
instance, prog->name, prog->instances.nr);
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
if (bpf_obj_pin(prog->instances.fds[instance], path)) {
|
|
err = -errno;
|
|
cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
|
|
pr_warn("failed to pin program: %s\n", cp);
|
|
return libbpf_err(err);
|
|
}
|
|
pr_debug("pinned program '%s'\n", path);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_program_unpin_instance(struct bpf_program *prog, const char *path, int instance)
|
|
{
|
|
int err;
|
|
|
|
err = check_path(path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
if (prog == NULL) {
|
|
pr_warn("invalid program pointer\n");
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
if (instance < 0 || instance >= prog->instances.nr) {
|
|
pr_warn("invalid prog instance %d of prog %s (max %d)\n",
|
|
instance, prog->name, prog->instances.nr);
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
err = unlink(path);
|
|
if (err != 0)
|
|
return libbpf_err(-errno);
|
|
|
|
pr_debug("unpinned program '%s'\n", path);
|
|
|
|
return 0;
|
|
}
|
|
|
|
__attribute__((alias("bpf_program_pin_instance")))
|
|
int bpf_object__pin_instance(struct bpf_program *prog, const char *path, int instance);
|
|
|
|
__attribute__((alias("bpf_program_unpin_instance")))
|
|
int bpf_program__unpin_instance(struct bpf_program *prog, const char *path, int instance);
|
|
|
|
int bpf_program__pin(struct bpf_program *prog, const char *path)
|
|
{
|
|
int i, err;
|
|
|
|
err = make_parent_dir(path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
err = check_path(path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
if (prog == NULL) {
|
|
pr_warn("invalid program pointer\n");
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
if (prog->instances.nr <= 0) {
|
|
pr_warn("no instances of prog %s to pin\n", prog->name);
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
if (prog->instances.nr == 1) {
|
|
/* don't create subdirs when pinning single instance */
|
|
return bpf_program_pin_instance(prog, path, 0);
|
|
}
|
|
|
|
for (i = 0; i < prog->instances.nr; i++) {
|
|
char buf[PATH_MAX];
|
|
int len;
|
|
|
|
len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
|
|
if (len < 0) {
|
|
err = -EINVAL;
|
|
goto err_unpin;
|
|
} else if (len >= PATH_MAX) {
|
|
err = -ENAMETOOLONG;
|
|
goto err_unpin;
|
|
}
|
|
|
|
err = bpf_program_pin_instance(prog, buf, i);
|
|
if (err)
|
|
goto err_unpin;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_unpin:
|
|
for (i = i - 1; i >= 0; i--) {
|
|
char buf[PATH_MAX];
|
|
int len;
|
|
|
|
len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
|
|
if (len < 0)
|
|
continue;
|
|
else if (len >= PATH_MAX)
|
|
continue;
|
|
|
|
bpf_program_unpin_instance(prog, buf, i);
|
|
}
|
|
|
|
rmdir(path);
|
|
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
int bpf_program__unpin(struct bpf_program *prog, const char *path)
|
|
{
|
|
int i, err;
|
|
|
|
err = check_path(path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
if (prog == NULL) {
|
|
pr_warn("invalid program pointer\n");
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
if (prog->instances.nr <= 0) {
|
|
pr_warn("no instances of prog %s to pin\n", prog->name);
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
if (prog->instances.nr == 1) {
|
|
/* don't create subdirs when pinning single instance */
|
|
return bpf_program_unpin_instance(prog, path, 0);
|
|
}
|
|
|
|
for (i = 0; i < prog->instances.nr; i++) {
|
|
char buf[PATH_MAX];
|
|
int len;
|
|
|
|
len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
|
|
if (len < 0)
|
|
return libbpf_err(-EINVAL);
|
|
else if (len >= PATH_MAX)
|
|
return libbpf_err(-ENAMETOOLONG);
|
|
|
|
err = bpf_program_unpin_instance(prog, buf, i);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
err = rmdir(path);
|
|
if (err)
|
|
return libbpf_err(-errno);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bpf_map__pin(struct bpf_map *map, const char *path)
|
|
{
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
int err;
|
|
|
|
if (map == NULL) {
|
|
pr_warn("invalid map pointer\n");
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
if (map->pin_path) {
|
|
if (path && strcmp(path, map->pin_path)) {
|
|
pr_warn("map '%s' already has pin path '%s' different from '%s'\n",
|
|
bpf_map__name(map), map->pin_path, path);
|
|
return libbpf_err(-EINVAL);
|
|
} else if (map->pinned) {
|
|
pr_debug("map '%s' already pinned at '%s'; not re-pinning\n",
|
|
bpf_map__name(map), map->pin_path);
|
|
return 0;
|
|
}
|
|
} else {
|
|
if (!path) {
|
|
pr_warn("missing a path to pin map '%s' at\n",
|
|
bpf_map__name(map));
|
|
return libbpf_err(-EINVAL);
|
|
} else if (map->pinned) {
|
|
pr_warn("map '%s' already pinned\n", bpf_map__name(map));
|
|
return libbpf_err(-EEXIST);
|
|
}
|
|
|
|
map->pin_path = strdup(path);
|
|
if (!map->pin_path) {
|
|
err = -errno;
|
|
goto out_err;
|
|
}
|
|
}
|
|
|
|
err = make_parent_dir(map->pin_path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
err = check_path(map->pin_path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
if (bpf_obj_pin(map->fd, map->pin_path)) {
|
|
err = -errno;
|
|
goto out_err;
|
|
}
|
|
|
|
map->pinned = true;
|
|
pr_debug("pinned map '%s'\n", map->pin_path);
|
|
|
|
return 0;
|
|
|
|
out_err:
|
|
cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg));
|
|
pr_warn("failed to pin map: %s\n", cp);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
int bpf_map__unpin(struct bpf_map *map, const char *path)
|
|
{
|
|
int err;
|
|
|
|
if (map == NULL) {
|
|
pr_warn("invalid map pointer\n");
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
if (map->pin_path) {
|
|
if (path && strcmp(path, map->pin_path)) {
|
|
pr_warn("map '%s' already has pin path '%s' different from '%s'\n",
|
|
bpf_map__name(map), map->pin_path, path);
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
path = map->pin_path;
|
|
} else if (!path) {
|
|
pr_warn("no path to unpin map '%s' from\n",
|
|
bpf_map__name(map));
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
err = check_path(path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
err = unlink(path);
|
|
if (err != 0)
|
|
return libbpf_err(-errno);
|
|
|
|
map->pinned = false;
|
|
pr_debug("unpinned map '%s' from '%s'\n", bpf_map__name(map), path);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bpf_map__set_pin_path(struct bpf_map *map, const char *path)
|
|
{
|
|
char *new = NULL;
|
|
|
|
if (path) {
|
|
new = strdup(path);
|
|
if (!new)
|
|
return libbpf_err(-errno);
|
|
}
|
|
|
|
free(map->pin_path);
|
|
map->pin_path = new;
|
|
return 0;
|
|
}
|
|
|
|
__alias(bpf_map__pin_path)
|
|
const char *bpf_map__get_pin_path(const struct bpf_map *map);
|
|
|
|
const char *bpf_map__pin_path(const struct bpf_map *map)
|
|
{
|
|
return map->pin_path;
|
|
}
|
|
|
|
bool bpf_map__is_pinned(const struct bpf_map *map)
|
|
{
|
|
return map->pinned;
|
|
}
|
|
|
|
static void sanitize_pin_path(char *s)
|
|
{
|
|
/* bpffs disallows periods in path names */
|
|
while (*s) {
|
|
if (*s == '.')
|
|
*s = '_';
|
|
s++;
|
|
}
|
|
}
|
|
|
|
int bpf_object__pin_maps(struct bpf_object *obj, const char *path)
|
|
{
|
|
struct bpf_map *map;
|
|
int err;
|
|
|
|
if (!obj)
|
|
return libbpf_err(-ENOENT);
|
|
|
|
if (!obj->loaded) {
|
|
pr_warn("object not yet loaded; load it first\n");
|
|
return libbpf_err(-ENOENT);
|
|
}
|
|
|
|
bpf_object__for_each_map(map, obj) {
|
|
char *pin_path = NULL;
|
|
char buf[PATH_MAX];
|
|
|
|
if (!map->autocreate)
|
|
continue;
|
|
|
|
if (path) {
|
|
int len;
|
|
|
|
len = snprintf(buf, PATH_MAX, "%s/%s", path,
|
|
bpf_map__name(map));
|
|
if (len < 0) {
|
|
err = -EINVAL;
|
|
goto err_unpin_maps;
|
|
} else if (len >= PATH_MAX) {
|
|
err = -ENAMETOOLONG;
|
|
goto err_unpin_maps;
|
|
}
|
|
sanitize_pin_path(buf);
|
|
pin_path = buf;
|
|
} else if (!map->pin_path) {
|
|
continue;
|
|
}
|
|
|
|
err = bpf_map__pin(map, pin_path);
|
|
if (err)
|
|
goto err_unpin_maps;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_unpin_maps:
|
|
while ((map = bpf_object__prev_map(obj, map))) {
|
|
if (!map->pin_path)
|
|
continue;
|
|
|
|
bpf_map__unpin(map, NULL);
|
|
}
|
|
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
int bpf_object__unpin_maps(struct bpf_object *obj, const char *path)
|
|
{
|
|
struct bpf_map *map;
|
|
int err;
|
|
|
|
if (!obj)
|
|
return libbpf_err(-ENOENT);
|
|
|
|
bpf_object__for_each_map(map, obj) {
|
|
char *pin_path = NULL;
|
|
char buf[PATH_MAX];
|
|
|
|
if (path) {
|
|
int len;
|
|
|
|
len = snprintf(buf, PATH_MAX, "%s/%s", path,
|
|
bpf_map__name(map));
|
|
if (len < 0)
|
|
return libbpf_err(-EINVAL);
|
|
else if (len >= PATH_MAX)
|
|
return libbpf_err(-ENAMETOOLONG);
|
|
sanitize_pin_path(buf);
|
|
pin_path = buf;
|
|
} else if (!map->pin_path) {
|
|
continue;
|
|
}
|
|
|
|
err = bpf_map__unpin(map, pin_path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bpf_object__pin_programs(struct bpf_object *obj, const char *path)
|
|
{
|
|
struct bpf_program *prog;
|
|
int err;
|
|
|
|
if (!obj)
|
|
return libbpf_err(-ENOENT);
|
|
|
|
if (!obj->loaded) {
|
|
pr_warn("object not yet loaded; load it first\n");
|
|
return libbpf_err(-ENOENT);
|
|
}
|
|
|
|
bpf_object__for_each_program(prog, obj) {
|
|
char buf[PATH_MAX];
|
|
int len;
|
|
|
|
len = snprintf(buf, PATH_MAX, "%s/%s", path,
|
|
prog->pin_name);
|
|
if (len < 0) {
|
|
err = -EINVAL;
|
|
goto err_unpin_programs;
|
|
} else if (len >= PATH_MAX) {
|
|
err = -ENAMETOOLONG;
|
|
goto err_unpin_programs;
|
|
}
|
|
|
|
err = bpf_program__pin(prog, buf);
|
|
if (err)
|
|
goto err_unpin_programs;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_unpin_programs:
|
|
while ((prog = bpf_object__prev_program(obj, prog))) {
|
|
char buf[PATH_MAX];
|
|
int len;
|
|
|
|
len = snprintf(buf, PATH_MAX, "%s/%s", path,
|
|
prog->pin_name);
|
|
if (len < 0)
|
|
continue;
|
|
else if (len >= PATH_MAX)
|
|
continue;
|
|
|
|
bpf_program__unpin(prog, buf);
|
|
}
|
|
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
int bpf_object__unpin_programs(struct bpf_object *obj, const char *path)
|
|
{
|
|
struct bpf_program *prog;
|
|
int err;
|
|
|
|
if (!obj)
|
|
return libbpf_err(-ENOENT);
|
|
|
|
bpf_object__for_each_program(prog, obj) {
|
|
char buf[PATH_MAX];
|
|
int len;
|
|
|
|
len = snprintf(buf, PATH_MAX, "%s/%s", path,
|
|
prog->pin_name);
|
|
if (len < 0)
|
|
return libbpf_err(-EINVAL);
|
|
else if (len >= PATH_MAX)
|
|
return libbpf_err(-ENAMETOOLONG);
|
|
|
|
err = bpf_program__unpin(prog, buf);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bpf_object__pin(struct bpf_object *obj, const char *path)
|
|
{
|
|
int err;
|
|
|
|
err = bpf_object__pin_maps(obj, path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
err = bpf_object__pin_programs(obj, path);
|
|
if (err) {
|
|
bpf_object__unpin_maps(obj, path);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void bpf_map__destroy(struct bpf_map *map)
|
|
{
|
|
if (map->clear_priv)
|
|
map->clear_priv(map, map->priv);
|
|
map->priv = NULL;
|
|
map->clear_priv = NULL;
|
|
|
|
if (map->inner_map) {
|
|
bpf_map__destroy(map->inner_map);
|
|
zfree(&map->inner_map);
|
|
}
|
|
|
|
zfree(&map->init_slots);
|
|
map->init_slots_sz = 0;
|
|
|
|
if (map->mmaped) {
|
|
munmap(map->mmaped, bpf_map_mmap_sz(map));
|
|
map->mmaped = NULL;
|
|
}
|
|
|
|
if (map->st_ops) {
|
|
zfree(&map->st_ops->data);
|
|
zfree(&map->st_ops->progs);
|
|
zfree(&map->st_ops->kern_func_off);
|
|
zfree(&map->st_ops);
|
|
}
|
|
|
|
zfree(&map->name);
|
|
zfree(&map->real_name);
|
|
zfree(&map->pin_path);
|
|
|
|
if (map->fd >= 0)
|
|
zclose(map->fd);
|
|
}
|
|
|
|
void bpf_object__close(struct bpf_object *obj)
|
|
{
|
|
size_t i;
|
|
|
|
if (IS_ERR_OR_NULL(obj))
|
|
return;
|
|
|
|
if (obj->clear_priv)
|
|
obj->clear_priv(obj, obj->priv);
|
|
|
|
usdt_manager_free(obj->usdt_man);
|
|
obj->usdt_man = NULL;
|
|
|
|
bpf_gen__free(obj->gen_loader);
|
|
bpf_object__elf_finish(obj);
|
|
bpf_object_unload(obj);
|
|
btf__free(obj->btf);
|
|
btf_ext__free(obj->btf_ext);
|
|
|
|
for (i = 0; i < obj->nr_maps; i++)
|
|
bpf_map__destroy(&obj->maps[i]);
|
|
|
|
zfree(&obj->btf_custom_path);
|
|
zfree(&obj->kconfig);
|
|
zfree(&obj->externs);
|
|
obj->nr_extern = 0;
|
|
|
|
zfree(&obj->maps);
|
|
obj->nr_maps = 0;
|
|
|
|
if (obj->programs && obj->nr_programs) {
|
|
for (i = 0; i < obj->nr_programs; i++)
|
|
bpf_program__exit(&obj->programs[i]);
|
|
}
|
|
zfree(&obj->programs);
|
|
|
|
list_del(&obj->list);
|
|
free(obj);
|
|
}
|
|
|
|
struct bpf_object *
|
|
bpf_object__next(struct bpf_object *prev)
|
|
{
|
|
struct bpf_object *next;
|
|
bool strict = (libbpf_mode & LIBBPF_STRICT_NO_OBJECT_LIST);
|
|
|
|
if (strict)
|
|
return NULL;
|
|
|
|
if (!prev)
|
|
next = list_first_entry(&bpf_objects_list,
|
|
struct bpf_object,
|
|
list);
|
|
else
|
|
next = list_next_entry(prev, list);
|
|
|
|
/* Empty list is noticed here so don't need checking on entry. */
|
|
if (&next->list == &bpf_objects_list)
|
|
return NULL;
|
|
|
|
return next;
|
|
}
|
|
|
|
const char *bpf_object__name(const struct bpf_object *obj)
|
|
{
|
|
return obj ? obj->name : libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
unsigned int bpf_object__kversion(const struct bpf_object *obj)
|
|
{
|
|
return obj ? obj->kern_version : 0;
|
|
}
|
|
|
|
struct btf *bpf_object__btf(const struct bpf_object *obj)
|
|
{
|
|
return obj ? obj->btf : NULL;
|
|
}
|
|
|
|
int bpf_object__btf_fd(const struct bpf_object *obj)
|
|
{
|
|
return obj->btf ? btf__fd(obj->btf) : -1;
|
|
}
|
|
|
|
int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version)
|
|
{
|
|
if (obj->loaded)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
obj->kern_version = kern_version;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bpf_object__set_priv(struct bpf_object *obj, void *priv,
|
|
bpf_object_clear_priv_t clear_priv)
|
|
{
|
|
if (obj->priv && obj->clear_priv)
|
|
obj->clear_priv(obj, obj->priv);
|
|
|
|
obj->priv = priv;
|
|
obj->clear_priv = clear_priv;
|
|
return 0;
|
|
}
|
|
|
|
void *bpf_object__priv(const struct bpf_object *obj)
|
|
{
|
|
return obj ? obj->priv : libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
int bpf_object__gen_loader(struct bpf_object *obj, struct gen_loader_opts *opts)
|
|
{
|
|
struct bpf_gen *gen;
|
|
|
|
if (!opts)
|
|
return -EFAULT;
|
|
if (!OPTS_VALID(opts, gen_loader_opts))
|
|
return -EINVAL;
|
|
gen = calloc(sizeof(*gen), 1);
|
|
if (!gen)
|
|
return -ENOMEM;
|
|
gen->opts = opts;
|
|
obj->gen_loader = gen;
|
|
return 0;
|
|
}
|
|
|
|
static struct bpf_program *
|
|
__bpf_program__iter(const struct bpf_program *p, const struct bpf_object *obj,
|
|
bool forward)
|
|
{
|
|
size_t nr_programs = obj->nr_programs;
|
|
ssize_t idx;
|
|
|
|
if (!nr_programs)
|
|
return NULL;
|
|
|
|
if (!p)
|
|
/* Iter from the beginning */
|
|
return forward ? &obj->programs[0] :
|
|
&obj->programs[nr_programs - 1];
|
|
|
|
if (p->obj != obj) {
|
|
pr_warn("error: program handler doesn't match object\n");
|
|
return errno = EINVAL, NULL;
|
|
}
|
|
|
|
idx = (p - obj->programs) + (forward ? 1 : -1);
|
|
if (idx >= obj->nr_programs || idx < 0)
|
|
return NULL;
|
|
return &obj->programs[idx];
|
|
}
|
|
|
|
struct bpf_program *
|
|
bpf_program__next(struct bpf_program *prev, const struct bpf_object *obj)
|
|
{
|
|
return bpf_object__next_program(obj, prev);
|
|
}
|
|
|
|
struct bpf_program *
|
|
bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prev)
|
|
{
|
|
struct bpf_program *prog = prev;
|
|
|
|
do {
|
|
prog = __bpf_program__iter(prog, obj, true);
|
|
} while (prog && prog_is_subprog(obj, prog));
|
|
|
|
return prog;
|
|
}
|
|
|
|
struct bpf_program *
|
|
bpf_program__prev(struct bpf_program *next, const struct bpf_object *obj)
|
|
{
|
|
return bpf_object__prev_program(obj, next);
|
|
}
|
|
|
|
struct bpf_program *
|
|
bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *next)
|
|
{
|
|
struct bpf_program *prog = next;
|
|
|
|
do {
|
|
prog = __bpf_program__iter(prog, obj, false);
|
|
} while (prog && prog_is_subprog(obj, prog));
|
|
|
|
return prog;
|
|
}
|
|
|
|
int bpf_program__set_priv(struct bpf_program *prog, void *priv,
|
|
bpf_program_clear_priv_t clear_priv)
|
|
{
|
|
if (prog->priv && prog->clear_priv)
|
|
prog->clear_priv(prog, prog->priv);
|
|
|
|
prog->priv = priv;
|
|
prog->clear_priv = clear_priv;
|
|
return 0;
|
|
}
|
|
|
|
void *bpf_program__priv(const struct bpf_program *prog)
|
|
{
|
|
return prog ? prog->priv : libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex)
|
|
{
|
|
prog->prog_ifindex = ifindex;
|
|
}
|
|
|
|
const char *bpf_program__name(const struct bpf_program *prog)
|
|
{
|
|
return prog->name;
|
|
}
|
|
|
|
const char *bpf_program__section_name(const struct bpf_program *prog)
|
|
{
|
|
return prog->sec_name;
|
|
}
|
|
|
|
const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy)
|
|
{
|
|
const char *title;
|
|
|
|
title = prog->sec_name;
|
|
if (needs_copy) {
|
|
title = strdup(title);
|
|
if (!title) {
|
|
pr_warn("failed to strdup program title\n");
|
|
return libbpf_err_ptr(-ENOMEM);
|
|
}
|
|
}
|
|
|
|
return title;
|
|
}
|
|
|
|
bool bpf_program__autoload(const struct bpf_program *prog)
|
|
{
|
|
return prog->autoload;
|
|
}
|
|
|
|
int bpf_program__set_autoload(struct bpf_program *prog, bool autoload)
|
|
{
|
|
if (prog->obj->loaded)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
prog->autoload = autoload;
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_program_nth_fd(const struct bpf_program *prog, int n);
|
|
|
|
int bpf_program__fd(const struct bpf_program *prog)
|
|
{
|
|
return bpf_program_nth_fd(prog, 0);
|
|
}
|
|
|
|
size_t bpf_program__size(const struct bpf_program *prog)
|
|
{
|
|
return prog->insns_cnt * BPF_INSN_SZ;
|
|
}
|
|
|
|
const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog)
|
|
{
|
|
return prog->insns;
|
|
}
|
|
|
|
size_t bpf_program__insn_cnt(const struct bpf_program *prog)
|
|
{
|
|
return prog->insns_cnt;
|
|
}
|
|
|
|
int bpf_program__set_insns(struct bpf_program *prog,
|
|
struct bpf_insn *new_insns, size_t new_insn_cnt)
|
|
{
|
|
struct bpf_insn *insns;
|
|
|
|
if (prog->obj->loaded)
|
|
return -EBUSY;
|
|
|
|
insns = libbpf_reallocarray(prog->insns, new_insn_cnt, sizeof(*insns));
|
|
if (!insns) {
|
|
pr_warn("prog '%s': failed to realloc prog code\n", prog->name);
|
|
return -ENOMEM;
|
|
}
|
|
memcpy(insns, new_insns, new_insn_cnt * sizeof(*insns));
|
|
|
|
prog->insns = insns;
|
|
prog->insns_cnt = new_insn_cnt;
|
|
return 0;
|
|
}
|
|
|
|
int bpf_program__set_prep(struct bpf_program *prog, int nr_instances,
|
|
bpf_program_prep_t prep)
|
|
{
|
|
int *instances_fds;
|
|
|
|
if (nr_instances <= 0 || !prep)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
if (prog->instances.nr > 0 || prog->instances.fds) {
|
|
pr_warn("Can't set pre-processor after loading\n");
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
instances_fds = malloc(sizeof(int) * nr_instances);
|
|
if (!instances_fds) {
|
|
pr_warn("alloc memory failed for fds\n");
|
|
return libbpf_err(-ENOMEM);
|
|
}
|
|
|
|
/* fill all fd with -1 */
|
|
memset(instances_fds, -1, sizeof(int) * nr_instances);
|
|
|
|
prog->instances.nr = nr_instances;
|
|
prog->instances.fds = instances_fds;
|
|
prog->preprocessor = prep;
|
|
return 0;
|
|
}
|
|
|
|
__attribute__((alias("bpf_program_nth_fd")))
|
|
int bpf_program__nth_fd(const struct bpf_program *prog, int n);
|
|
|
|
static int bpf_program_nth_fd(const struct bpf_program *prog, int n)
|
|
{
|
|
int fd;
|
|
|
|
if (!prog)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
if (n >= prog->instances.nr || n < 0) {
|
|
pr_warn("Can't get the %dth fd from program %s: only %d instances\n",
|
|
n, prog->name, prog->instances.nr);
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
fd = prog->instances.fds[n];
|
|
if (fd < 0) {
|
|
pr_warn("%dth instance of program '%s' is invalid\n",
|
|
n, prog->name);
|
|
return libbpf_err(-ENOENT);
|
|
}
|
|
|
|
return fd;
|
|
}
|
|
|
|
__alias(bpf_program__type)
|
|
enum bpf_prog_type bpf_program__get_type(const struct bpf_program *prog);
|
|
|
|
enum bpf_prog_type bpf_program__type(const struct bpf_program *prog)
|
|
{
|
|
return prog->type;
|
|
}
|
|
|
|
int bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type)
|
|
{
|
|
if (prog->obj->loaded)
|
|
return libbpf_err(-EBUSY);
|
|
|
|
prog->type = type;
|
|
return 0;
|
|
}
|
|
|
|
static bool bpf_program__is_type(const struct bpf_program *prog,
|
|
enum bpf_prog_type type)
|
|
{
|
|
return prog ? (prog->type == type) : false;
|
|
}
|
|
|
|
#define BPF_PROG_TYPE_FNS(NAME, TYPE) \
|
|
int bpf_program__set_##NAME(struct bpf_program *prog) \
|
|
{ \
|
|
if (!prog) \
|
|
return libbpf_err(-EINVAL); \
|
|
return bpf_program__set_type(prog, TYPE); \
|
|
} \
|
|
\
|
|
bool bpf_program__is_##NAME(const struct bpf_program *prog) \
|
|
{ \
|
|
return bpf_program__is_type(prog, TYPE); \
|
|
} \
|
|
|
|
BPF_PROG_TYPE_FNS(socket_filter, BPF_PROG_TYPE_SOCKET_FILTER);
|
|
BPF_PROG_TYPE_FNS(lsm, BPF_PROG_TYPE_LSM);
|
|
BPF_PROG_TYPE_FNS(kprobe, BPF_PROG_TYPE_KPROBE);
|
|
BPF_PROG_TYPE_FNS(sched_cls, BPF_PROG_TYPE_SCHED_CLS);
|
|
BPF_PROG_TYPE_FNS(sched_act, BPF_PROG_TYPE_SCHED_ACT);
|
|
BPF_PROG_TYPE_FNS(tracepoint, BPF_PROG_TYPE_TRACEPOINT);
|
|
BPF_PROG_TYPE_FNS(raw_tracepoint, BPF_PROG_TYPE_RAW_TRACEPOINT);
|
|
BPF_PROG_TYPE_FNS(xdp, BPF_PROG_TYPE_XDP);
|
|
BPF_PROG_TYPE_FNS(perf_event, BPF_PROG_TYPE_PERF_EVENT);
|
|
BPF_PROG_TYPE_FNS(tracing, BPF_PROG_TYPE_TRACING);
|
|
BPF_PROG_TYPE_FNS(struct_ops, BPF_PROG_TYPE_STRUCT_OPS);
|
|
BPF_PROG_TYPE_FNS(extension, BPF_PROG_TYPE_EXT);
|
|
BPF_PROG_TYPE_FNS(sk_lookup, BPF_PROG_TYPE_SK_LOOKUP);
|
|
|
|
__alias(bpf_program__expected_attach_type)
|
|
enum bpf_attach_type bpf_program__get_expected_attach_type(const struct bpf_program *prog);
|
|
|
|
enum bpf_attach_type bpf_program__expected_attach_type(const struct bpf_program *prog)
|
|
{
|
|
return prog->expected_attach_type;
|
|
}
|
|
|
|
int bpf_program__set_expected_attach_type(struct bpf_program *prog,
|
|
enum bpf_attach_type type)
|
|
{
|
|
if (prog->obj->loaded)
|
|
return libbpf_err(-EBUSY);
|
|
|
|
prog->expected_attach_type = type;
|
|
return 0;
|
|
}
|
|
|
|
__u32 bpf_program__flags(const struct bpf_program *prog)
|
|
{
|
|
return prog->prog_flags;
|
|
}
|
|
|
|
int bpf_program__set_flags(struct bpf_program *prog, __u32 flags)
|
|
{
|
|
if (prog->obj->loaded)
|
|
return libbpf_err(-EBUSY);
|
|
|
|
prog->prog_flags = flags;
|
|
return 0;
|
|
}
|
|
|
|
__u32 bpf_program__log_level(const struct bpf_program *prog)
|
|
{
|
|
return prog->log_level;
|
|
}
|
|
|
|
int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level)
|
|
{
|
|
if (prog->obj->loaded)
|
|
return libbpf_err(-EBUSY);
|
|
|
|
prog->log_level = log_level;
|
|
return 0;
|
|
}
|
|
|
|
const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size)
|
|
{
|
|
*log_size = prog->log_size;
|
|
return prog->log_buf;
|
|
}
|
|
|
|
int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size)
|
|
{
|
|
if (log_size && !log_buf)
|
|
return -EINVAL;
|
|
if (prog->log_size > UINT_MAX)
|
|
return -EINVAL;
|
|
if (prog->obj->loaded)
|
|
return -EBUSY;
|
|
|
|
prog->log_buf = log_buf;
|
|
prog->log_size = log_size;
|
|
return 0;
|
|
}
|
|
|
|
#define SEC_DEF(sec_pfx, ptype, atype, flags, ...) { \
|
|
.sec = (char *)sec_pfx, \
|
|
.prog_type = BPF_PROG_TYPE_##ptype, \
|
|
.expected_attach_type = atype, \
|
|
.cookie = (long)(flags), \
|
|
.prog_prepare_load_fn = libbpf_prepare_prog_load, \
|
|
__VA_ARGS__ \
|
|
}
|
|
|
|
static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link);
|
|
static int attach_uprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link);
|
|
static int attach_usdt(const struct bpf_program *prog, long cookie, struct bpf_link **link);
|
|
static int attach_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link);
|
|
static int attach_raw_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link);
|
|
static int attach_trace(const struct bpf_program *prog, long cookie, struct bpf_link **link);
|
|
static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link);
|
|
static int attach_lsm(const struct bpf_program *prog, long cookie, struct bpf_link **link);
|
|
static int attach_iter(const struct bpf_program *prog, long cookie, struct bpf_link **link);
|
|
|
|
static const struct bpf_sec_def section_defs[] = {
|
|
SEC_DEF("socket", SOCKET_FILTER, 0, SEC_NONE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("sk_reuseport/migrate", SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("sk_reuseport", SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("kprobe+", KPROBE, 0, SEC_NONE, attach_kprobe),
|
|
SEC_DEF("uprobe+", KPROBE, 0, SEC_NONE, attach_uprobe),
|
|
SEC_DEF("kretprobe+", KPROBE, 0, SEC_NONE, attach_kprobe),
|
|
SEC_DEF("uretprobe+", KPROBE, 0, SEC_NONE, attach_uprobe),
|
|
SEC_DEF("kprobe.multi+", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi),
|
|
SEC_DEF("kretprobe.multi+", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi),
|
|
SEC_DEF("usdt+", KPROBE, 0, SEC_NONE, attach_usdt),
|
|
SEC_DEF("tc", SCHED_CLS, 0, SEC_NONE),
|
|
SEC_DEF("classifier", SCHED_CLS, 0, SEC_NONE | SEC_SLOPPY_PFX | SEC_DEPRECATED),
|
|
SEC_DEF("action", SCHED_ACT, 0, SEC_NONE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("tracepoint+", TRACEPOINT, 0, SEC_NONE, attach_tp),
|
|
SEC_DEF("tp+", TRACEPOINT, 0, SEC_NONE, attach_tp),
|
|
SEC_DEF("raw_tracepoint+", RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
|
|
SEC_DEF("raw_tp+", RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
|
|
SEC_DEF("raw_tracepoint.w+", RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp),
|
|
SEC_DEF("raw_tp.w+", RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp),
|
|
SEC_DEF("tp_btf+", TRACING, BPF_TRACE_RAW_TP, SEC_ATTACH_BTF, attach_trace),
|
|
SEC_DEF("fentry+", TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF, attach_trace),
|
|
SEC_DEF("fmod_ret+", TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF, attach_trace),
|
|
SEC_DEF("fexit+", TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF, attach_trace),
|
|
SEC_DEF("fentry.s+", TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
|
|
SEC_DEF("fmod_ret.s+", TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
|
|
SEC_DEF("fexit.s+", TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
|
|
SEC_DEF("freplace+", EXT, 0, SEC_ATTACH_BTF, attach_trace),
|
|
SEC_DEF("lsm+", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF, attach_lsm),
|
|
SEC_DEF("lsm.s+", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_lsm),
|
|
SEC_DEF("iter+", TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF, attach_iter),
|
|
SEC_DEF("iter.s+", TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_iter),
|
|
SEC_DEF("syscall", SYSCALL, 0, SEC_SLEEPABLE),
|
|
SEC_DEF("xdp.frags/devmap", XDP, BPF_XDP_DEVMAP, SEC_XDP_FRAGS),
|
|
SEC_DEF("xdp/devmap", XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE),
|
|
SEC_DEF("xdp_devmap/", XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE | SEC_DEPRECATED),
|
|
SEC_DEF("xdp.frags/cpumap", XDP, BPF_XDP_CPUMAP, SEC_XDP_FRAGS),
|
|
SEC_DEF("xdp/cpumap", XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE),
|
|
SEC_DEF("xdp_cpumap/", XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE | SEC_DEPRECATED),
|
|
SEC_DEF("xdp.frags", XDP, BPF_XDP, SEC_XDP_FRAGS),
|
|
SEC_DEF("xdp", XDP, BPF_XDP, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
|
|
SEC_DEF("perf_event", PERF_EVENT, 0, SEC_NONE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("lwt_in", LWT_IN, 0, SEC_NONE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("lwt_out", LWT_OUT, 0, SEC_NONE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("lwt_xmit", LWT_XMIT, 0, SEC_NONE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("lwt_seg6local", LWT_SEG6LOCAL, 0, SEC_NONE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup_skb/ingress", CGROUP_SKB, BPF_CGROUP_INET_INGRESS, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup_skb/egress", CGROUP_SKB, BPF_CGROUP_INET_EGRESS, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/skb", CGROUP_SKB, 0, SEC_NONE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/sock_create", CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/sock_release", CGROUP_SOCK, BPF_CGROUP_INET_SOCK_RELEASE, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/sock", CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/post_bind4", CGROUP_SOCK, BPF_CGROUP_INET4_POST_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/post_bind6", CGROUP_SOCK, BPF_CGROUP_INET6_POST_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/dev", CGROUP_DEVICE, BPF_CGROUP_DEVICE, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
|
|
SEC_DEF("sockops", SOCK_OPS, BPF_CGROUP_SOCK_OPS, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
|
|
SEC_DEF("sk_skb/stream_parser", SK_SKB, BPF_SK_SKB_STREAM_PARSER, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
|
|
SEC_DEF("sk_skb/stream_verdict",SK_SKB, BPF_SK_SKB_STREAM_VERDICT, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
|
|
SEC_DEF("sk_skb", SK_SKB, 0, SEC_NONE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("sk_msg", SK_MSG, BPF_SK_MSG_VERDICT, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
|
|
SEC_DEF("lirc_mode2", LIRC_MODE2, BPF_LIRC_MODE2, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
|
|
SEC_DEF("flow_dissector", FLOW_DISSECTOR, BPF_FLOW_DISSECTOR, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/bind4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/bind6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/connect4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_CONNECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/connect6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_CONNECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/sendmsg4", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_SENDMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/sendmsg6", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_SENDMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/recvmsg4", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_RECVMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/recvmsg6", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_RECVMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/getpeername4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETPEERNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/getpeername6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETPEERNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/getsockname4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETSOCKNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/getsockname6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETSOCKNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/sysctl", CGROUP_SYSCTL, BPF_CGROUP_SYSCTL, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/getsockopt", CGROUP_SOCKOPT, BPF_CGROUP_GETSOCKOPT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("cgroup/setsockopt", CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
SEC_DEF("struct_ops+", STRUCT_OPS, 0, SEC_NONE),
|
|
SEC_DEF("sk_lookup", SK_LOOKUP, BPF_SK_LOOKUP, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
|
|
};
|
|
|
|
static size_t custom_sec_def_cnt;
|
|
static struct bpf_sec_def *custom_sec_defs;
|
|
static struct bpf_sec_def custom_fallback_def;
|
|
static bool has_custom_fallback_def;
|
|
|
|
static int last_custom_sec_def_handler_id;
|
|
|
|
int libbpf_register_prog_handler(const char *sec,
|
|
enum bpf_prog_type prog_type,
|
|
enum bpf_attach_type exp_attach_type,
|
|
const struct libbpf_prog_handler_opts *opts)
|
|
{
|
|
struct bpf_sec_def *sec_def;
|
|
|
|
if (!OPTS_VALID(opts, libbpf_prog_handler_opts))
|
|
return libbpf_err(-EINVAL);
|
|
|
|
if (last_custom_sec_def_handler_id == INT_MAX) /* prevent overflow */
|
|
return libbpf_err(-E2BIG);
|
|
|
|
if (sec) {
|
|
sec_def = libbpf_reallocarray(custom_sec_defs, custom_sec_def_cnt + 1,
|
|
sizeof(*sec_def));
|
|
if (!sec_def)
|
|
return libbpf_err(-ENOMEM);
|
|
|
|
custom_sec_defs = sec_def;
|
|
sec_def = &custom_sec_defs[custom_sec_def_cnt];
|
|
} else {
|
|
if (has_custom_fallback_def)
|
|
return libbpf_err(-EBUSY);
|
|
|
|
sec_def = &custom_fallback_def;
|
|
}
|
|
|
|
sec_def->sec = sec ? strdup(sec) : NULL;
|
|
if (sec && !sec_def->sec)
|
|
return libbpf_err(-ENOMEM);
|
|
|
|
sec_def->prog_type = prog_type;
|
|
sec_def->expected_attach_type = exp_attach_type;
|
|
sec_def->cookie = OPTS_GET(opts, cookie, 0);
|
|
|
|
sec_def->prog_setup_fn = OPTS_GET(opts, prog_setup_fn, NULL);
|
|
sec_def->prog_prepare_load_fn = OPTS_GET(opts, prog_prepare_load_fn, NULL);
|
|
sec_def->prog_attach_fn = OPTS_GET(opts, prog_attach_fn, NULL);
|
|
|
|
sec_def->handler_id = ++last_custom_sec_def_handler_id;
|
|
|
|
if (sec)
|
|
custom_sec_def_cnt++;
|
|
else
|
|
has_custom_fallback_def = true;
|
|
|
|
return sec_def->handler_id;
|
|
}
|
|
|
|
int libbpf_unregister_prog_handler(int handler_id)
|
|
{
|
|
struct bpf_sec_def *sec_defs;
|
|
int i;
|
|
|
|
if (handler_id <= 0)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
if (has_custom_fallback_def && custom_fallback_def.handler_id == handler_id) {
|
|
memset(&custom_fallback_def, 0, sizeof(custom_fallback_def));
|
|
has_custom_fallback_def = false;
|
|
return 0;
|
|
}
|
|
|
|
for (i = 0; i < custom_sec_def_cnt; i++) {
|
|
if (custom_sec_defs[i].handler_id == handler_id)
|
|
break;
|
|
}
|
|
|
|
if (i == custom_sec_def_cnt)
|
|
return libbpf_err(-ENOENT);
|
|
|
|
free(custom_sec_defs[i].sec);
|
|
for (i = i + 1; i < custom_sec_def_cnt; i++)
|
|
custom_sec_defs[i - 1] = custom_sec_defs[i];
|
|
custom_sec_def_cnt--;
|
|
|
|
/* try to shrink the array, but it's ok if we couldn't */
|
|
sec_defs = libbpf_reallocarray(custom_sec_defs, custom_sec_def_cnt, sizeof(*sec_defs));
|
|
if (sec_defs)
|
|
custom_sec_defs = sec_defs;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool sec_def_matches(const struct bpf_sec_def *sec_def, const char *sec_name,
|
|
bool allow_sloppy)
|
|
{
|
|
size_t len = strlen(sec_def->sec);
|
|
|
|
/* "type/" always has to have proper SEC("type/extras") form */
|
|
if (sec_def->sec[len - 1] == '/') {
|
|
if (str_has_pfx(sec_name, sec_def->sec))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/* "type+" means it can be either exact SEC("type") or
|
|
* well-formed SEC("type/extras") with proper '/' separator
|
|
*/
|
|
if (sec_def->sec[len - 1] == '+') {
|
|
len--;
|
|
/* not even a prefix */
|
|
if (strncmp(sec_name, sec_def->sec, len) != 0)
|
|
return false;
|
|
/* exact match or has '/' separator */
|
|
if (sec_name[len] == '\0' || sec_name[len] == '/')
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/* SEC_SLOPPY_PFX definitions are allowed to be just prefix
|
|
* matches, unless strict section name mode
|
|
* (LIBBPF_STRICT_SEC_NAME) is enabled, in which case the
|
|
* match has to be exact.
|
|
*/
|
|
if (allow_sloppy && str_has_pfx(sec_name, sec_def->sec))
|
|
return true;
|
|
|
|
/* Definitions not marked SEC_SLOPPY_PFX (e.g.,
|
|
* SEC("syscall")) are exact matches in both modes.
|
|
*/
|
|
return strcmp(sec_name, sec_def->sec) == 0;
|
|
}
|
|
|
|
static const struct bpf_sec_def *find_sec_def(const char *sec_name)
|
|
{
|
|
const struct bpf_sec_def *sec_def;
|
|
int i, n;
|
|
bool strict = libbpf_mode & LIBBPF_STRICT_SEC_NAME, allow_sloppy;
|
|
|
|
n = custom_sec_def_cnt;
|
|
for (i = 0; i < n; i++) {
|
|
sec_def = &custom_sec_defs[i];
|
|
if (sec_def_matches(sec_def, sec_name, false))
|
|
return sec_def;
|
|
}
|
|
|
|
n = ARRAY_SIZE(section_defs);
|
|
for (i = 0; i < n; i++) {
|
|
sec_def = §ion_defs[i];
|
|
allow_sloppy = (sec_def->cookie & SEC_SLOPPY_PFX) && !strict;
|
|
if (sec_def_matches(sec_def, sec_name, allow_sloppy))
|
|
return sec_def;
|
|
}
|
|
|
|
if (has_custom_fallback_def)
|
|
return &custom_fallback_def;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
#define MAX_TYPE_NAME_SIZE 32
|
|
|
|
static char *libbpf_get_type_names(bool attach_type)
|
|
{
|
|
int i, len = ARRAY_SIZE(section_defs) * MAX_TYPE_NAME_SIZE;
|
|
char *buf;
|
|
|
|
buf = malloc(len);
|
|
if (!buf)
|
|
return NULL;
|
|
|
|
buf[0] = '\0';
|
|
/* Forge string buf with all available names */
|
|
for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
|
|
const struct bpf_sec_def *sec_def = §ion_defs[i];
|
|
|
|
if (attach_type) {
|
|
if (sec_def->prog_prepare_load_fn != libbpf_prepare_prog_load)
|
|
continue;
|
|
|
|
if (!(sec_def->cookie & SEC_ATTACHABLE))
|
|
continue;
|
|
}
|
|
|
|
if (strlen(buf) + strlen(section_defs[i].sec) + 2 > len) {
|
|
free(buf);
|
|
return NULL;
|
|
}
|
|
strcat(buf, " ");
|
|
strcat(buf, section_defs[i].sec);
|
|
}
|
|
|
|
return buf;
|
|
}
|
|
|
|
int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
|
|
enum bpf_attach_type *expected_attach_type)
|
|
{
|
|
const struct bpf_sec_def *sec_def;
|
|
char *type_names;
|
|
|
|
if (!name)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
sec_def = find_sec_def(name);
|
|
if (sec_def) {
|
|
*prog_type = sec_def->prog_type;
|
|
*expected_attach_type = sec_def->expected_attach_type;
|
|
return 0;
|
|
}
|
|
|
|
pr_debug("failed to guess program type from ELF section '%s'\n", name);
|
|
type_names = libbpf_get_type_names(false);
|
|
if (type_names != NULL) {
|
|
pr_debug("supported section(type) names are:%s\n", type_names);
|
|
free(type_names);
|
|
}
|
|
|
|
return libbpf_err(-ESRCH);
|
|
}
|
|
|
|
static struct bpf_map *find_struct_ops_map_by_offset(struct bpf_object *obj,
|
|
size_t offset)
|
|
{
|
|
struct bpf_map *map;
|
|
size_t i;
|
|
|
|
for (i = 0; i < obj->nr_maps; i++) {
|
|
map = &obj->maps[i];
|
|
if (!bpf_map__is_struct_ops(map))
|
|
continue;
|
|
if (map->sec_offset <= offset &&
|
|
offset - map->sec_offset < map->def.value_size)
|
|
return map;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Collect the reloc from ELF and populate the st_ops->progs[] */
|
|
static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
|
|
Elf64_Shdr *shdr, Elf_Data *data)
|
|
{
|
|
const struct btf_member *member;
|
|
struct bpf_struct_ops *st_ops;
|
|
struct bpf_program *prog;
|
|
unsigned int shdr_idx;
|
|
const struct btf *btf;
|
|
struct bpf_map *map;
|
|
unsigned int moff, insn_idx;
|
|
const char *name;
|
|
__u32 member_idx;
|
|
Elf64_Sym *sym;
|
|
Elf64_Rel *rel;
|
|
int i, nrels;
|
|
|
|
btf = obj->btf;
|
|
nrels = shdr->sh_size / shdr->sh_entsize;
|
|
for (i = 0; i < nrels; i++) {
|
|
rel = elf_rel_by_idx(data, i);
|
|
if (!rel) {
|
|
pr_warn("struct_ops reloc: failed to get %d reloc\n", i);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
sym = elf_sym_by_idx(obj, ELF64_R_SYM(rel->r_info));
|
|
if (!sym) {
|
|
pr_warn("struct_ops reloc: symbol %zx not found\n",
|
|
(size_t)ELF64_R_SYM(rel->r_info));
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
name = elf_sym_str(obj, sym->st_name) ?: "<?>";
|
|
map = find_struct_ops_map_by_offset(obj, rel->r_offset);
|
|
if (!map) {
|
|
pr_warn("struct_ops reloc: cannot find map at rel->r_offset %zu\n",
|
|
(size_t)rel->r_offset);
|
|
return -EINVAL;
|
|
}
|
|
|
|
moff = rel->r_offset - map->sec_offset;
|
|
shdr_idx = sym->st_shndx;
|
|
st_ops = map->st_ops;
|
|
pr_debug("struct_ops reloc %s: for %lld value %lld shdr_idx %u rel->r_offset %zu map->sec_offset %zu name %d (\'%s\')\n",
|
|
map->name,
|
|
(long long)(rel->r_info >> 32),
|
|
(long long)sym->st_value,
|
|
shdr_idx, (size_t)rel->r_offset,
|
|
map->sec_offset, sym->st_name, name);
|
|
|
|
if (shdr_idx >= SHN_LORESERVE) {
|
|
pr_warn("struct_ops reloc %s: rel->r_offset %zu shdr_idx %u unsupported non-static function\n",
|
|
map->name, (size_t)rel->r_offset, shdr_idx);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
if (sym->st_value % BPF_INSN_SZ) {
|
|
pr_warn("struct_ops reloc %s: invalid target program offset %llu\n",
|
|
map->name, (unsigned long long)sym->st_value);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
insn_idx = sym->st_value / BPF_INSN_SZ;
|
|
|
|
member = find_member_by_offset(st_ops->type, moff * 8);
|
|
if (!member) {
|
|
pr_warn("struct_ops reloc %s: cannot find member at moff %u\n",
|
|
map->name, moff);
|
|
return -EINVAL;
|
|
}
|
|
member_idx = member - btf_members(st_ops->type);
|
|
name = btf__name_by_offset(btf, member->name_off);
|
|
|
|
if (!resolve_func_ptr(btf, member->type, NULL)) {
|
|
pr_warn("struct_ops reloc %s: cannot relocate non func ptr %s\n",
|
|
map->name, name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
prog = find_prog_by_sec_insn(obj, shdr_idx, insn_idx);
|
|
if (!prog) {
|
|
pr_warn("struct_ops reloc %s: cannot find prog at shdr_idx %u to relocate func ptr %s\n",
|
|
map->name, shdr_idx, name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* prevent the use of BPF prog with invalid type */
|
|
if (prog->type != BPF_PROG_TYPE_STRUCT_OPS) {
|
|
pr_warn("struct_ops reloc %s: prog %s is not struct_ops BPF program\n",
|
|
map->name, prog->name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* if we haven't yet processed this BPF program, record proper
|
|
* attach_btf_id and member_idx
|
|
*/
|
|
if (!prog->attach_btf_id) {
|
|
prog->attach_btf_id = st_ops->type_id;
|
|
prog->expected_attach_type = member_idx;
|
|
}
|
|
|
|
/* struct_ops BPF prog can be re-used between multiple
|
|
* .struct_ops as long as it's the same struct_ops struct
|
|
* definition and the same function pointer field
|
|
*/
|
|
if (prog->attach_btf_id != st_ops->type_id ||
|
|
prog->expected_attach_type != member_idx) {
|
|
pr_warn("struct_ops reloc %s: cannot use prog %s in sec %s with type %u attach_btf_id %u expected_attach_type %u for func ptr %s\n",
|
|
map->name, prog->name, prog->sec_name, prog->type,
|
|
prog->attach_btf_id, prog->expected_attach_type, name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
st_ops->progs[member_idx] = prog;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define BTF_TRACE_PREFIX "btf_trace_"
|
|
#define BTF_LSM_PREFIX "bpf_lsm_"
|
|
#define BTF_ITER_PREFIX "bpf_iter_"
|
|
#define BTF_MAX_NAME_SIZE 128
|
|
|
|
void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type,
|
|
const char **prefix, int *kind)
|
|
{
|
|
switch (attach_type) {
|
|
case BPF_TRACE_RAW_TP:
|
|
*prefix = BTF_TRACE_PREFIX;
|
|
*kind = BTF_KIND_TYPEDEF;
|
|
break;
|
|
case BPF_LSM_MAC:
|
|
*prefix = BTF_LSM_PREFIX;
|
|
*kind = BTF_KIND_FUNC;
|
|
break;
|
|
case BPF_TRACE_ITER:
|
|
*prefix = BTF_ITER_PREFIX;
|
|
*kind = BTF_KIND_FUNC;
|
|
break;
|
|
default:
|
|
*prefix = "";
|
|
*kind = BTF_KIND_FUNC;
|
|
}
|
|
}
|
|
|
|
static int find_btf_by_prefix_kind(const struct btf *btf, const char *prefix,
|
|
const char *name, __u32 kind)
|
|
{
|
|
char btf_type_name[BTF_MAX_NAME_SIZE];
|
|
int ret;
|
|
|
|
ret = snprintf(btf_type_name, sizeof(btf_type_name),
|
|
"%s%s", prefix, name);
|
|
/* snprintf returns the number of characters written excluding the
|
|
* terminating null. So, if >= BTF_MAX_NAME_SIZE are written, it
|
|
* indicates truncation.
|
|
*/
|
|
if (ret < 0 || ret >= sizeof(btf_type_name))
|
|
return -ENAMETOOLONG;
|
|
return btf__find_by_name_kind(btf, btf_type_name, kind);
|
|
}
|
|
|
|
static inline int find_attach_btf_id(struct btf *btf, const char *name,
|
|
enum bpf_attach_type attach_type)
|
|
{
|
|
const char *prefix;
|
|
int kind;
|
|
|
|
btf_get_kernel_prefix_kind(attach_type, &prefix, &kind);
|
|
return find_btf_by_prefix_kind(btf, prefix, name, kind);
|
|
}
|
|
|
|
int libbpf_find_vmlinux_btf_id(const char *name,
|
|
enum bpf_attach_type attach_type)
|
|
{
|
|
struct btf *btf;
|
|
int err;
|
|
|
|
btf = btf__load_vmlinux_btf();
|
|
err = libbpf_get_error(btf);
|
|
if (err) {
|
|
pr_warn("vmlinux BTF is not found\n");
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
err = find_attach_btf_id(btf, name, attach_type);
|
|
if (err <= 0)
|
|
pr_warn("%s is not found in vmlinux BTF\n", name);
|
|
|
|
btf__free(btf);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd)
|
|
{
|
|
struct bpf_prog_info info = {};
|
|
__u32 info_len = sizeof(info);
|
|
struct btf *btf;
|
|
int err;
|
|
|
|
err = bpf_obj_get_info_by_fd(attach_prog_fd, &info, &info_len);
|
|
if (err) {
|
|
pr_warn("failed bpf_obj_get_info_by_fd for FD %d: %d\n",
|
|
attach_prog_fd, err);
|
|
return err;
|
|
}
|
|
|
|
err = -EINVAL;
|
|
if (!info.btf_id) {
|
|
pr_warn("The target program doesn't have BTF\n");
|
|
goto out;
|
|
}
|
|
btf = btf__load_from_kernel_by_id(info.btf_id);
|
|
err = libbpf_get_error(btf);
|
|
if (err) {
|
|
pr_warn("Failed to get BTF %d of the program: %d\n", info.btf_id, err);
|
|
goto out;
|
|
}
|
|
err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC);
|
|
btf__free(btf);
|
|
if (err <= 0) {
|
|
pr_warn("%s is not found in prog's BTF\n", name);
|
|
goto out;
|
|
}
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static int find_kernel_btf_id(struct bpf_object *obj, const char *attach_name,
|
|
enum bpf_attach_type attach_type,
|
|
int *btf_obj_fd, int *btf_type_id)
|
|
{
|
|
int ret, i;
|
|
|
|
ret = find_attach_btf_id(obj->btf_vmlinux, attach_name, attach_type);
|
|
if (ret > 0) {
|
|
*btf_obj_fd = 0; /* vmlinux BTF */
|
|
*btf_type_id = ret;
|
|
return 0;
|
|
}
|
|
if (ret != -ENOENT)
|
|
return ret;
|
|
|
|
ret = load_module_btfs(obj);
|
|
if (ret)
|
|
return ret;
|
|
|
|
for (i = 0; i < obj->btf_module_cnt; i++) {
|
|
const struct module_btf *mod = &obj->btf_modules[i];
|
|
|
|
ret = find_attach_btf_id(mod->btf, attach_name, attach_type);
|
|
if (ret > 0) {
|
|
*btf_obj_fd = mod->fd;
|
|
*btf_type_id = ret;
|
|
return 0;
|
|
}
|
|
if (ret == -ENOENT)
|
|
continue;
|
|
|
|
return ret;
|
|
}
|
|
|
|
return -ESRCH;
|
|
}
|
|
|
|
static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attach_name,
|
|
int *btf_obj_fd, int *btf_type_id)
|
|
{
|
|
enum bpf_attach_type attach_type = prog->expected_attach_type;
|
|
__u32 attach_prog_fd = prog->attach_prog_fd;
|
|
int err = 0;
|
|
|
|
/* BPF program's BTF ID */
|
|
if (attach_prog_fd) {
|
|
err = libbpf_find_prog_btf_id(attach_name, attach_prog_fd);
|
|
if (err < 0) {
|
|
pr_warn("failed to find BPF program (FD %d) BTF ID for '%s': %d\n",
|
|
attach_prog_fd, attach_name, err);
|
|
return err;
|
|
}
|
|
*btf_obj_fd = 0;
|
|
*btf_type_id = err;
|
|
return 0;
|
|
}
|
|
|
|
/* kernel/module BTF ID */
|
|
if (prog->obj->gen_loader) {
|
|
bpf_gen__record_attach_target(prog->obj->gen_loader, attach_name, attach_type);
|
|
*btf_obj_fd = 0;
|
|
*btf_type_id = 1;
|
|
} else {
|
|
err = find_kernel_btf_id(prog->obj, attach_name, attach_type, btf_obj_fd, btf_type_id);
|
|
}
|
|
if (err) {
|
|
pr_warn("failed to find kernel BTF type ID of '%s': %d\n", attach_name, err);
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int libbpf_attach_type_by_name(const char *name,
|
|
enum bpf_attach_type *attach_type)
|
|
{
|
|
char *type_names;
|
|
const struct bpf_sec_def *sec_def;
|
|
|
|
if (!name)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
sec_def = find_sec_def(name);
|
|
if (!sec_def) {
|
|
pr_debug("failed to guess attach type based on ELF section name '%s'\n", name);
|
|
type_names = libbpf_get_type_names(true);
|
|
if (type_names != NULL) {
|
|
pr_debug("attachable section(type) names are:%s\n", type_names);
|
|
free(type_names);
|
|
}
|
|
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
if (sec_def->prog_prepare_load_fn != libbpf_prepare_prog_load)
|
|
return libbpf_err(-EINVAL);
|
|
if (!(sec_def->cookie & SEC_ATTACHABLE))
|
|
return libbpf_err(-EINVAL);
|
|
|
|
*attach_type = sec_def->expected_attach_type;
|
|
return 0;
|
|
}
|
|
|
|
int bpf_map__fd(const struct bpf_map *map)
|
|
{
|
|
return map ? map->fd : libbpf_err(-EINVAL);
|
|
}
|
|
|
|
const struct bpf_map_def *bpf_map__def(const struct bpf_map *map)
|
|
{
|
|
return map ? &map->def : libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
static bool map_uses_real_name(const struct bpf_map *map)
|
|
{
|
|
/* Since libbpf started to support custom .data.* and .rodata.* maps,
|
|
* their user-visible name differs from kernel-visible name. Users see
|
|
* such map's corresponding ELF section name as a map name.
|
|
* This check distinguishes .data/.rodata from .data.* and .rodata.*
|
|
* maps to know which name has to be returned to the user.
|
|
*/
|
|
if (map->libbpf_type == LIBBPF_MAP_DATA && strcmp(map->real_name, DATA_SEC) != 0)
|
|
return true;
|
|
if (map->libbpf_type == LIBBPF_MAP_RODATA && strcmp(map->real_name, RODATA_SEC) != 0)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
const char *bpf_map__name(const struct bpf_map *map)
|
|
{
|
|
if (!map)
|
|
return NULL;
|
|
|
|
if (map_uses_real_name(map))
|
|
return map->real_name;
|
|
|
|
return map->name;
|
|
}
|
|
|
|
enum bpf_map_type bpf_map__type(const struct bpf_map *map)
|
|
{
|
|
return map->def.type;
|
|
}
|
|
|
|
int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type)
|
|
{
|
|
if (map->fd >= 0)
|
|
return libbpf_err(-EBUSY);
|
|
map->def.type = type;
|
|
return 0;
|
|
}
|
|
|
|
__u32 bpf_map__map_flags(const struct bpf_map *map)
|
|
{
|
|
return map->def.map_flags;
|
|
}
|
|
|
|
int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags)
|
|
{
|
|
if (map->fd >= 0)
|
|
return libbpf_err(-EBUSY);
|
|
map->def.map_flags = flags;
|
|
return 0;
|
|
}
|
|
|
|
__u64 bpf_map__map_extra(const struct bpf_map *map)
|
|
{
|
|
return map->map_extra;
|
|
}
|
|
|
|
int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra)
|
|
{
|
|
if (map->fd >= 0)
|
|
return libbpf_err(-EBUSY);
|
|
map->map_extra = map_extra;
|
|
return 0;
|
|
}
|
|
|
|
__u32 bpf_map__numa_node(const struct bpf_map *map)
|
|
{
|
|
return map->numa_node;
|
|
}
|
|
|
|
int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node)
|
|
{
|
|
if (map->fd >= 0)
|
|
return libbpf_err(-EBUSY);
|
|
map->numa_node = numa_node;
|
|
return 0;
|
|
}
|
|
|
|
__u32 bpf_map__key_size(const struct bpf_map *map)
|
|
{
|
|
return map->def.key_size;
|
|
}
|
|
|
|
int bpf_map__set_key_size(struct bpf_map *map, __u32 size)
|
|
{
|
|
if (map->fd >= 0)
|
|
return libbpf_err(-EBUSY);
|
|
map->def.key_size = size;
|
|
return 0;
|
|
}
|
|
|
|
__u32 bpf_map__value_size(const struct bpf_map *map)
|
|
{
|
|
return map->def.value_size;
|
|
}
|
|
|
|
int bpf_map__set_value_size(struct bpf_map *map, __u32 size)
|
|
{
|
|
if (map->fd >= 0)
|
|
return libbpf_err(-EBUSY);
|
|
map->def.value_size = size;
|
|
return 0;
|
|
}
|
|
|
|
__u32 bpf_map__btf_key_type_id(const struct bpf_map *map)
|
|
{
|
|
return map ? map->btf_key_type_id : 0;
|
|
}
|
|
|
|
__u32 bpf_map__btf_value_type_id(const struct bpf_map *map)
|
|
{
|
|
return map ? map->btf_value_type_id : 0;
|
|
}
|
|
|
|
int bpf_map__set_priv(struct bpf_map *map, void *priv,
|
|
bpf_map_clear_priv_t clear_priv)
|
|
{
|
|
if (!map)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
if (map->priv) {
|
|
if (map->clear_priv)
|
|
map->clear_priv(map, map->priv);
|
|
}
|
|
|
|
map->priv = priv;
|
|
map->clear_priv = clear_priv;
|
|
return 0;
|
|
}
|
|
|
|
void *bpf_map__priv(const struct bpf_map *map)
|
|
{
|
|
return map ? map->priv : libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
int bpf_map__set_initial_value(struct bpf_map *map,
|
|
const void *data, size_t size)
|
|
{
|
|
if (!map->mmaped || map->libbpf_type == LIBBPF_MAP_KCONFIG ||
|
|
size != map->def.value_size || map->fd >= 0)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
memcpy(map->mmaped, data, size);
|
|
return 0;
|
|
}
|
|
|
|
const void *bpf_map__initial_value(struct bpf_map *map, size_t *psize)
|
|
{
|
|
if (!map->mmaped)
|
|
return NULL;
|
|
*psize = map->def.value_size;
|
|
return map->mmaped;
|
|
}
|
|
|
|
bool bpf_map__is_offload_neutral(const struct bpf_map *map)
|
|
{
|
|
return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY;
|
|
}
|
|
|
|
bool bpf_map__is_internal(const struct bpf_map *map)
|
|
{
|
|
return map->libbpf_type != LIBBPF_MAP_UNSPEC;
|
|
}
|
|
|
|
__u32 bpf_map__ifindex(const struct bpf_map *map)
|
|
{
|
|
return map->map_ifindex;
|
|
}
|
|
|
|
int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
|
|
{
|
|
if (map->fd >= 0)
|
|
return libbpf_err(-EBUSY);
|
|
map->map_ifindex = ifindex;
|
|
return 0;
|
|
}
|
|
|
|
int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd)
|
|
{
|
|
if (!bpf_map_type__is_map_in_map(map->def.type)) {
|
|
pr_warn("error: unsupported map type\n");
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
if (map->inner_map_fd != -1) {
|
|
pr_warn("error: inner_map_fd already specified\n");
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
if (map->inner_map) {
|
|
bpf_map__destroy(map->inner_map);
|
|
zfree(&map->inner_map);
|
|
}
|
|
map->inner_map_fd = fd;
|
|
return 0;
|
|
}
|
|
|
|
static struct bpf_map *
|
|
__bpf_map__iter(const struct bpf_map *m, const struct bpf_object *obj, int i)
|
|
{
|
|
ssize_t idx;
|
|
struct bpf_map *s, *e;
|
|
|
|
if (!obj || !obj->maps)
|
|
return errno = EINVAL, NULL;
|
|
|
|
s = obj->maps;
|
|
e = obj->maps + obj->nr_maps;
|
|
|
|
if ((m < s) || (m >= e)) {
|
|
pr_warn("error in %s: map handler doesn't belong to object\n",
|
|
__func__);
|
|
return errno = EINVAL, NULL;
|
|
}
|
|
|
|
idx = (m - obj->maps) + i;
|
|
if (idx >= obj->nr_maps || idx < 0)
|
|
return NULL;
|
|
return &obj->maps[idx];
|
|
}
|
|
|
|
struct bpf_map *
|
|
bpf_map__next(const struct bpf_map *prev, const struct bpf_object *obj)
|
|
{
|
|
return bpf_object__next_map(obj, prev);
|
|
}
|
|
|
|
struct bpf_map *
|
|
bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev)
|
|
{
|
|
if (prev == NULL)
|
|
return obj->maps;
|
|
|
|
return __bpf_map__iter(prev, obj, 1);
|
|
}
|
|
|
|
struct bpf_map *
|
|
bpf_map__prev(const struct bpf_map *next, const struct bpf_object *obj)
|
|
{
|
|
return bpf_object__prev_map(obj, next);
|
|
}
|
|
|
|
struct bpf_map *
|
|
bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *next)
|
|
{
|
|
if (next == NULL) {
|
|
if (!obj->nr_maps)
|
|
return NULL;
|
|
return obj->maps + obj->nr_maps - 1;
|
|
}
|
|
|
|
return __bpf_map__iter(next, obj, -1);
|
|
}
|
|
|
|
struct bpf_map *
|
|
bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name)
|
|
{
|
|
struct bpf_map *pos;
|
|
|
|
bpf_object__for_each_map(pos, obj) {
|
|
/* if it's a special internal map name (which always starts
|
|
* with dot) then check if that special name matches the
|
|
* real map name (ELF section name)
|
|
*/
|
|
if (name[0] == '.') {
|
|
if (pos->real_name && strcmp(pos->real_name, name) == 0)
|
|
return pos;
|
|
continue;
|
|
}
|
|
/* otherwise map name has to be an exact match */
|
|
if (map_uses_real_name(pos)) {
|
|
if (strcmp(pos->real_name, name) == 0)
|
|
return pos;
|
|
continue;
|
|
}
|
|
if (strcmp(pos->name, name) == 0)
|
|
return pos;
|
|
}
|
|
return errno = ENOENT, NULL;
|
|
}
|
|
|
|
int
|
|
bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name)
|
|
{
|
|
return bpf_map__fd(bpf_object__find_map_by_name(obj, name));
|
|
}
|
|
|
|
struct bpf_map *
|
|
bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset)
|
|
{
|
|
return libbpf_err_ptr(-ENOTSUP);
|
|
}
|
|
|
|
static int validate_map_op(const struct bpf_map *map, size_t key_sz,
|
|
size_t value_sz, bool check_value_sz)
|
|
{
|
|
if (map->fd <= 0)
|
|
return -ENOENT;
|
|
|
|
if (map->def.key_size != key_sz) {
|
|
pr_warn("map '%s': unexpected key size %zu provided, expected %u\n",
|
|
map->name, key_sz, map->def.key_size);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!check_value_sz)
|
|
return 0;
|
|
|
|
switch (map->def.type) {
|
|
case BPF_MAP_TYPE_PERCPU_ARRAY:
|
|
case BPF_MAP_TYPE_PERCPU_HASH:
|
|
case BPF_MAP_TYPE_LRU_PERCPU_HASH:
|
|
case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: {
|
|
int num_cpu = libbpf_num_possible_cpus();
|
|
size_t elem_sz = roundup(map->def.value_size, 8);
|
|
|
|
if (value_sz != num_cpu * elem_sz) {
|
|
pr_warn("map '%s': unexpected value size %zu provided for per-CPU map, expected %d * %zu = %zd\n",
|
|
map->name, value_sz, num_cpu, elem_sz, num_cpu * elem_sz);
|
|
return -EINVAL;
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
if (map->def.value_size != value_sz) {
|
|
pr_warn("map '%s': unexpected value size %zu provided, expected %u\n",
|
|
map->name, value_sz, map->def.value_size);
|
|
return -EINVAL;
|
|
}
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int bpf_map__lookup_elem(const struct bpf_map *map,
|
|
const void *key, size_t key_sz,
|
|
void *value, size_t value_sz, __u64 flags)
|
|
{
|
|
int err;
|
|
|
|
err = validate_map_op(map, key_sz, value_sz, true);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
return bpf_map_lookup_elem_flags(map->fd, key, value, flags);
|
|
}
|
|
|
|
int bpf_map__update_elem(const struct bpf_map *map,
|
|
const void *key, size_t key_sz,
|
|
const void *value, size_t value_sz, __u64 flags)
|
|
{
|
|
int err;
|
|
|
|
err = validate_map_op(map, key_sz, value_sz, true);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
return bpf_map_update_elem(map->fd, key, value, flags);
|
|
}
|
|
|
|
int bpf_map__delete_elem(const struct bpf_map *map,
|
|
const void *key, size_t key_sz, __u64 flags)
|
|
{
|
|
int err;
|
|
|
|
err = validate_map_op(map, key_sz, 0, false /* check_value_sz */);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
return bpf_map_delete_elem_flags(map->fd, key, flags);
|
|
}
|
|
|
|
int bpf_map__lookup_and_delete_elem(const struct bpf_map *map,
|
|
const void *key, size_t key_sz,
|
|
void *value, size_t value_sz, __u64 flags)
|
|
{
|
|
int err;
|
|
|
|
err = validate_map_op(map, key_sz, value_sz, true);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
return bpf_map_lookup_and_delete_elem_flags(map->fd, key, value, flags);
|
|
}
|
|
|
|
int bpf_map__get_next_key(const struct bpf_map *map,
|
|
const void *cur_key, void *next_key, size_t key_sz)
|
|
{
|
|
int err;
|
|
|
|
err = validate_map_op(map, key_sz, 0, false /* check_value_sz */);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
return bpf_map_get_next_key(map->fd, cur_key, next_key);
|
|
}
|
|
|
|
long libbpf_get_error(const void *ptr)
|
|
{
|
|
if (!IS_ERR_OR_NULL(ptr))
|
|
return 0;
|
|
|
|
if (IS_ERR(ptr))
|
|
errno = -PTR_ERR(ptr);
|
|
|
|
/* If ptr == NULL, then errno should be already set by the failing
|
|
* API, because libbpf never returns NULL on success and it now always
|
|
* sets errno on error. So no extra errno handling for ptr == NULL
|
|
* case.
|
|
*/
|
|
return -errno;
|
|
}
|
|
|
|
__attribute__((alias("bpf_prog_load_xattr2")))
|
|
int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
|
|
struct bpf_object **pobj, int *prog_fd);
|
|
|
|
static int bpf_prog_load_xattr2(const struct bpf_prog_load_attr *attr,
|
|
struct bpf_object **pobj, int *prog_fd)
|
|
{
|
|
struct bpf_object_open_attr open_attr = {};
|
|
struct bpf_program *prog, *first_prog = NULL;
|
|
struct bpf_object *obj;
|
|
struct bpf_map *map;
|
|
int err;
|
|
|
|
if (!attr)
|
|
return libbpf_err(-EINVAL);
|
|
if (!attr->file)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
open_attr.file = attr->file;
|
|
open_attr.prog_type = attr->prog_type;
|
|
|
|
obj = __bpf_object__open_xattr(&open_attr, 0);
|
|
err = libbpf_get_error(obj);
|
|
if (err)
|
|
return libbpf_err(-ENOENT);
|
|
|
|
bpf_object__for_each_program(prog, obj) {
|
|
enum bpf_attach_type attach_type = attr->expected_attach_type;
|
|
/*
|
|
* to preserve backwards compatibility, bpf_prog_load treats
|
|
* attr->prog_type, if specified, as an override to whatever
|
|
* bpf_object__open guessed
|
|
*/
|
|
if (attr->prog_type != BPF_PROG_TYPE_UNSPEC) {
|
|
prog->type = attr->prog_type;
|
|
prog->expected_attach_type = attach_type;
|
|
}
|
|
if (bpf_program__type(prog) == BPF_PROG_TYPE_UNSPEC) {
|
|
/*
|
|
* we haven't guessed from section name and user
|
|
* didn't provide a fallback type, too bad...
|
|
*/
|
|
bpf_object__close(obj);
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
prog->prog_ifindex = attr->ifindex;
|
|
prog->log_level = attr->log_level;
|
|
prog->prog_flags |= attr->prog_flags;
|
|
if (!first_prog)
|
|
first_prog = prog;
|
|
}
|
|
|
|
bpf_object__for_each_map(map, obj) {
|
|
if (map->def.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY)
|
|
map->map_ifindex = attr->ifindex;
|
|
}
|
|
|
|
if (!first_prog) {
|
|
pr_warn("object file doesn't contain bpf program\n");
|
|
bpf_object__close(obj);
|
|
return libbpf_err(-ENOENT);
|
|
}
|
|
|
|
err = bpf_object__load(obj);
|
|
if (err) {
|
|
bpf_object__close(obj);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
*pobj = obj;
|
|
*prog_fd = bpf_program__fd(first_prog);
|
|
return 0;
|
|
}
|
|
|
|
COMPAT_VERSION(bpf_prog_load_deprecated, bpf_prog_load, LIBBPF_0.0.1)
|
|
int bpf_prog_load_deprecated(const char *file, enum bpf_prog_type type,
|
|
struct bpf_object **pobj, int *prog_fd)
|
|
{
|
|
struct bpf_prog_load_attr attr;
|
|
|
|
memset(&attr, 0, sizeof(struct bpf_prog_load_attr));
|
|
attr.file = file;
|
|
attr.prog_type = type;
|
|
attr.expected_attach_type = 0;
|
|
|
|
return bpf_prog_load_xattr2(&attr, pobj, prog_fd);
|
|
}
|
|
|
|
/* Replace link's underlying BPF program with the new one */
|
|
int bpf_link__update_program(struct bpf_link *link, struct bpf_program *prog)
|
|
{
|
|
int ret;
|
|
|
|
ret = bpf_link_update(bpf_link__fd(link), bpf_program__fd(prog), NULL);
|
|
return libbpf_err_errno(ret);
|
|
}
|
|
|
|
/* Release "ownership" of underlying BPF resource (typically, BPF program
|
|
* attached to some BPF hook, e.g., tracepoint, kprobe, etc). Disconnected
|
|
* link, when destructed through bpf_link__destroy() call won't attempt to
|
|
* detach/unregisted that BPF resource. This is useful in situations where,
|
|
* say, attached BPF program has to outlive userspace program that attached it
|
|
* in the system. Depending on type of BPF program, though, there might be
|
|
* additional steps (like pinning BPF program in BPF FS) necessary to ensure
|
|
* exit of userspace program doesn't trigger automatic detachment and clean up
|
|
* inside the kernel.
|
|
*/
|
|
void bpf_link__disconnect(struct bpf_link *link)
|
|
{
|
|
link->disconnected = true;
|
|
}
|
|
|
|
int bpf_link__destroy(struct bpf_link *link)
|
|
{
|
|
int err = 0;
|
|
|
|
if (IS_ERR_OR_NULL(link))
|
|
return 0;
|
|
|
|
if (!link->disconnected && link->detach)
|
|
err = link->detach(link);
|
|
if (link->pin_path)
|
|
free(link->pin_path);
|
|
if (link->dealloc)
|
|
link->dealloc(link);
|
|
else
|
|
free(link);
|
|
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
int bpf_link__fd(const struct bpf_link *link)
|
|
{
|
|
return link->fd;
|
|
}
|
|
|
|
const char *bpf_link__pin_path(const struct bpf_link *link)
|
|
{
|
|
return link->pin_path;
|
|
}
|
|
|
|
static int bpf_link__detach_fd(struct bpf_link *link)
|
|
{
|
|
return libbpf_err_errno(close(link->fd));
|
|
}
|
|
|
|
struct bpf_link *bpf_link__open(const char *path)
|
|
{
|
|
struct bpf_link *link;
|
|
int fd;
|
|
|
|
fd = bpf_obj_get(path);
|
|
if (fd < 0) {
|
|
fd = -errno;
|
|
pr_warn("failed to open link at %s: %d\n", path, fd);
|
|
return libbpf_err_ptr(fd);
|
|
}
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link) {
|
|
close(fd);
|
|
return libbpf_err_ptr(-ENOMEM);
|
|
}
|
|
link->detach = &bpf_link__detach_fd;
|
|
link->fd = fd;
|
|
|
|
link->pin_path = strdup(path);
|
|
if (!link->pin_path) {
|
|
bpf_link__destroy(link);
|
|
return libbpf_err_ptr(-ENOMEM);
|
|
}
|
|
|
|
return link;
|
|
}
|
|
|
|
int bpf_link__detach(struct bpf_link *link)
|
|
{
|
|
return bpf_link_detach(link->fd) ? -errno : 0;
|
|
}
|
|
|
|
int bpf_link__pin(struct bpf_link *link, const char *path)
|
|
{
|
|
int err;
|
|
|
|
if (link->pin_path)
|
|
return libbpf_err(-EBUSY);
|
|
err = make_parent_dir(path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
err = check_path(path);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
link->pin_path = strdup(path);
|
|
if (!link->pin_path)
|
|
return libbpf_err(-ENOMEM);
|
|
|
|
if (bpf_obj_pin(link->fd, link->pin_path)) {
|
|
err = -errno;
|
|
zfree(&link->pin_path);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
pr_debug("link fd=%d: pinned at %s\n", link->fd, link->pin_path);
|
|
return 0;
|
|
}
|
|
|
|
int bpf_link__unpin(struct bpf_link *link)
|
|
{
|
|
int err;
|
|
|
|
if (!link->pin_path)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
err = unlink(link->pin_path);
|
|
if (err != 0)
|
|
return -errno;
|
|
|
|
pr_debug("link fd=%d: unpinned from %s\n", link->fd, link->pin_path);
|
|
zfree(&link->pin_path);
|
|
return 0;
|
|
}
|
|
|
|
struct bpf_link_perf {
|
|
struct bpf_link link;
|
|
int perf_event_fd;
|
|
/* legacy kprobe support: keep track of probe identifier and type */
|
|
char *legacy_probe_name;
|
|
bool legacy_is_kprobe;
|
|
bool legacy_is_retprobe;
|
|
};
|
|
|
|
static int remove_kprobe_event_legacy(const char *probe_name, bool retprobe);
|
|
static int remove_uprobe_event_legacy(const char *probe_name, bool retprobe);
|
|
|
|
static int bpf_link_perf_detach(struct bpf_link *link)
|
|
{
|
|
struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
|
|
int err = 0;
|
|
|
|
if (ioctl(perf_link->perf_event_fd, PERF_EVENT_IOC_DISABLE, 0) < 0)
|
|
err = -errno;
|
|
|
|
if (perf_link->perf_event_fd != link->fd)
|
|
close(perf_link->perf_event_fd);
|
|
close(link->fd);
|
|
|
|
/* legacy uprobe/kprobe needs to be removed after perf event fd closure */
|
|
if (perf_link->legacy_probe_name) {
|
|
if (perf_link->legacy_is_kprobe) {
|
|
err = remove_kprobe_event_legacy(perf_link->legacy_probe_name,
|
|
perf_link->legacy_is_retprobe);
|
|
} else {
|
|
err = remove_uprobe_event_legacy(perf_link->legacy_probe_name,
|
|
perf_link->legacy_is_retprobe);
|
|
}
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static void bpf_link_perf_dealloc(struct bpf_link *link)
|
|
{
|
|
struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
|
|
|
|
free(perf_link->legacy_probe_name);
|
|
free(perf_link);
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,
|
|
const struct bpf_perf_event_opts *opts)
|
|
{
|
|
char errmsg[STRERR_BUFSIZE];
|
|
struct bpf_link_perf *link;
|
|
int prog_fd, link_fd = -1, err;
|
|
|
|
if (!OPTS_VALID(opts, bpf_perf_event_opts))
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
if (pfd < 0) {
|
|
pr_warn("prog '%s': invalid perf event FD %d\n",
|
|
prog->name, pfd);
|
|
return libbpf_err_ptr(-EINVAL);
|
|
}
|
|
prog_fd = bpf_program__fd(prog);
|
|
if (prog_fd < 0) {
|
|
pr_warn("prog '%s': can't attach BPF program w/o FD (did you load it?)\n",
|
|
prog->name);
|
|
return libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link)
|
|
return libbpf_err_ptr(-ENOMEM);
|
|
link->link.detach = &bpf_link_perf_detach;
|
|
link->link.dealloc = &bpf_link_perf_dealloc;
|
|
link->perf_event_fd = pfd;
|
|
|
|
if (kernel_supports(prog->obj, FEAT_PERF_LINK)) {
|
|
DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_opts,
|
|
.perf_event.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0));
|
|
|
|
link_fd = bpf_link_create(prog_fd, pfd, BPF_PERF_EVENT, &link_opts);
|
|
if (link_fd < 0) {
|
|
err = -errno;
|
|
pr_warn("prog '%s': failed to create BPF link for perf_event FD %d: %d (%s)\n",
|
|
prog->name, pfd,
|
|
err, libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
goto err_out;
|
|
}
|
|
link->link.fd = link_fd;
|
|
} else {
|
|
if (OPTS_GET(opts, bpf_cookie, 0)) {
|
|
pr_warn("prog '%s': user context value is not supported\n", prog->name);
|
|
err = -EOPNOTSUPP;
|
|
goto err_out;
|
|
}
|
|
|
|
if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) {
|
|
err = -errno;
|
|
pr_warn("prog '%s': failed to attach to perf_event FD %d: %s\n",
|
|
prog->name, pfd, libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
if (err == -EPROTO)
|
|
pr_warn("prog '%s': try add PERF_SAMPLE_CALLCHAIN to or remove exclude_callchain_[kernel|user] from pfd %d\n",
|
|
prog->name, pfd);
|
|
goto err_out;
|
|
}
|
|
link->link.fd = pfd;
|
|
}
|
|
if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) {
|
|
err = -errno;
|
|
pr_warn("prog '%s': failed to enable perf_event FD %d: %s\n",
|
|
prog->name, pfd, libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
goto err_out;
|
|
}
|
|
|
|
return &link->link;
|
|
err_out:
|
|
if (link_fd >= 0)
|
|
close(link_fd);
|
|
free(link);
|
|
return libbpf_err_ptr(err);
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd)
|
|
{
|
|
return bpf_program__attach_perf_event_opts(prog, pfd, NULL);
|
|
}
|
|
|
|
/*
|
|
* this function is expected to parse integer in the range of [0, 2^31-1] from
|
|
* given file using scanf format string fmt. If actual parsed value is
|
|
* negative, the result might be indistinguishable from error
|
|
*/
|
|
static int parse_uint_from_file(const char *file, const char *fmt)
|
|
{
|
|
char buf[STRERR_BUFSIZE];
|
|
int err, ret;
|
|
FILE *f;
|
|
|
|
f = fopen(file, "r");
|
|
if (!f) {
|
|
err = -errno;
|
|
pr_debug("failed to open '%s': %s\n", file,
|
|
libbpf_strerror_r(err, buf, sizeof(buf)));
|
|
return err;
|
|
}
|
|
err = fscanf(f, fmt, &ret);
|
|
if (err != 1) {
|
|
err = err == EOF ? -EIO : -errno;
|
|
pr_debug("failed to parse '%s': %s\n", file,
|
|
libbpf_strerror_r(err, buf, sizeof(buf)));
|
|
fclose(f);
|
|
return err;
|
|
}
|
|
fclose(f);
|
|
return ret;
|
|
}
|
|
|
|
static int determine_kprobe_perf_type(void)
|
|
{
|
|
const char *file = "/sys/bus/event_source/devices/kprobe/type";
|
|
|
|
return parse_uint_from_file(file, "%d\n");
|
|
}
|
|
|
|
static int determine_uprobe_perf_type(void)
|
|
{
|
|
const char *file = "/sys/bus/event_source/devices/uprobe/type";
|
|
|
|
return parse_uint_from_file(file, "%d\n");
|
|
}
|
|
|
|
static int determine_kprobe_retprobe_bit(void)
|
|
{
|
|
const char *file = "/sys/bus/event_source/devices/kprobe/format/retprobe";
|
|
|
|
return parse_uint_from_file(file, "config:%d\n");
|
|
}
|
|
|
|
static int determine_uprobe_retprobe_bit(void)
|
|
{
|
|
const char *file = "/sys/bus/event_source/devices/uprobe/format/retprobe";
|
|
|
|
return parse_uint_from_file(file, "config:%d\n");
|
|
}
|
|
|
|
#define PERF_UPROBE_REF_CTR_OFFSET_BITS 32
|
|
#define PERF_UPROBE_REF_CTR_OFFSET_SHIFT 32
|
|
|
|
static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
|
|
uint64_t offset, int pid, size_t ref_ctr_off)
|
|
{
|
|
struct perf_event_attr attr = {};
|
|
char errmsg[STRERR_BUFSIZE];
|
|
int type, pfd, err;
|
|
|
|
if (ref_ctr_off >= (1ULL << PERF_UPROBE_REF_CTR_OFFSET_BITS))
|
|
return -EINVAL;
|
|
|
|
type = uprobe ? determine_uprobe_perf_type()
|
|
: determine_kprobe_perf_type();
|
|
if (type < 0) {
|
|
pr_warn("failed to determine %s perf type: %s\n",
|
|
uprobe ? "uprobe" : "kprobe",
|
|
libbpf_strerror_r(type, errmsg, sizeof(errmsg)));
|
|
return type;
|
|
}
|
|
if (retprobe) {
|
|
int bit = uprobe ? determine_uprobe_retprobe_bit()
|
|
: determine_kprobe_retprobe_bit();
|
|
|
|
if (bit < 0) {
|
|
pr_warn("failed to determine %s retprobe bit: %s\n",
|
|
uprobe ? "uprobe" : "kprobe",
|
|
libbpf_strerror_r(bit, errmsg, sizeof(errmsg)));
|
|
return bit;
|
|
}
|
|
attr.config |= 1 << bit;
|
|
}
|
|
attr.size = sizeof(attr);
|
|
attr.type = type;
|
|
attr.config |= (__u64)ref_ctr_off << PERF_UPROBE_REF_CTR_OFFSET_SHIFT;
|
|
attr.config1 = ptr_to_u64(name); /* kprobe_func or uprobe_path */
|
|
attr.config2 = offset; /* kprobe_addr or probe_offset */
|
|
|
|
/* pid filter is meaningful only for uprobes */
|
|
pfd = syscall(__NR_perf_event_open, &attr,
|
|
pid < 0 ? -1 : pid /* pid */,
|
|
pid == -1 ? 0 : -1 /* cpu */,
|
|
-1 /* group_fd */, PERF_FLAG_FD_CLOEXEC);
|
|
if (pfd < 0) {
|
|
err = -errno;
|
|
pr_warn("%s perf_event_open() failed: %s\n",
|
|
uprobe ? "uprobe" : "kprobe",
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
return err;
|
|
}
|
|
return pfd;
|
|
}
|
|
|
|
static int append_to_file(const char *file, const char *fmt, ...)
|
|
{
|
|
int fd, n, err = 0;
|
|
va_list ap;
|
|
|
|
fd = open(file, O_WRONLY | O_APPEND | O_CLOEXEC, 0);
|
|
if (fd < 0)
|
|
return -errno;
|
|
|
|
va_start(ap, fmt);
|
|
n = vdprintf(fd, fmt, ap);
|
|
va_end(ap);
|
|
|
|
if (n < 0)
|
|
err = -errno;
|
|
|
|
close(fd);
|
|
return err;
|
|
}
|
|
|
|
static void gen_kprobe_legacy_event_name(char *buf, size_t buf_sz,
|
|
const char *kfunc_name, size_t offset)
|
|
{
|
|
static int index = 0;
|
|
|
|
snprintf(buf, buf_sz, "libbpf_%u_%s_0x%zx_%d", getpid(), kfunc_name, offset,
|
|
__sync_fetch_and_add(&index, 1));
|
|
}
|
|
|
|
static int add_kprobe_event_legacy(const char *probe_name, bool retprobe,
|
|
const char *kfunc_name, size_t offset)
|
|
{
|
|
const char *file = "/sys/kernel/debug/tracing/kprobe_events";
|
|
|
|
return append_to_file(file, "%c:%s/%s %s+0x%zx",
|
|
retprobe ? 'r' : 'p',
|
|
retprobe ? "kretprobes" : "kprobes",
|
|
probe_name, kfunc_name, offset);
|
|
}
|
|
|
|
static int remove_kprobe_event_legacy(const char *probe_name, bool retprobe)
|
|
{
|
|
const char *file = "/sys/kernel/debug/tracing/kprobe_events";
|
|
|
|
return append_to_file(file, "-:%s/%s", retprobe ? "kretprobes" : "kprobes", probe_name);
|
|
}
|
|
|
|
static int determine_kprobe_perf_type_legacy(const char *probe_name, bool retprobe)
|
|
{
|
|
char file[256];
|
|
|
|
snprintf(file, sizeof(file),
|
|
"/sys/kernel/debug/tracing/events/%s/%s/id",
|
|
retprobe ? "kretprobes" : "kprobes", probe_name);
|
|
|
|
return parse_uint_from_file(file, "%d\n");
|
|
}
|
|
|
|
static int perf_event_kprobe_open_legacy(const char *probe_name, bool retprobe,
|
|
const char *kfunc_name, size_t offset, int pid)
|
|
{
|
|
struct perf_event_attr attr = {};
|
|
char errmsg[STRERR_BUFSIZE];
|
|
int type, pfd, err;
|
|
|
|
err = add_kprobe_event_legacy(probe_name, retprobe, kfunc_name, offset);
|
|
if (err < 0) {
|
|
pr_warn("failed to add legacy kprobe event for '%s+0x%zx': %s\n",
|
|
kfunc_name, offset,
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
return err;
|
|
}
|
|
type = determine_kprobe_perf_type_legacy(probe_name, retprobe);
|
|
if (type < 0) {
|
|
pr_warn("failed to determine legacy kprobe event id for '%s+0x%zx': %s\n",
|
|
kfunc_name, offset,
|
|
libbpf_strerror_r(type, errmsg, sizeof(errmsg)));
|
|
return type;
|
|
}
|
|
attr.size = sizeof(attr);
|
|
attr.config = type;
|
|
attr.type = PERF_TYPE_TRACEPOINT;
|
|
|
|
pfd = syscall(__NR_perf_event_open, &attr,
|
|
pid < 0 ? -1 : pid, /* pid */
|
|
pid == -1 ? 0 : -1, /* cpu */
|
|
-1 /* group_fd */, PERF_FLAG_FD_CLOEXEC);
|
|
if (pfd < 0) {
|
|
err = -errno;
|
|
pr_warn("legacy kprobe perf_event_open() failed: %s\n",
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
return err;
|
|
}
|
|
return pfd;
|
|
}
|
|
|
|
struct bpf_link *
|
|
bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
|
|
const char *func_name,
|
|
const struct bpf_kprobe_opts *opts)
|
|
{
|
|
DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts);
|
|
char errmsg[STRERR_BUFSIZE];
|
|
char *legacy_probe = NULL;
|
|
struct bpf_link *link;
|
|
size_t offset;
|
|
bool retprobe, legacy;
|
|
int pfd, err;
|
|
|
|
if (!OPTS_VALID(opts, bpf_kprobe_opts))
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
retprobe = OPTS_GET(opts, retprobe, false);
|
|
offset = OPTS_GET(opts, offset, 0);
|
|
pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
|
|
|
|
legacy = determine_kprobe_perf_type() < 0;
|
|
if (!legacy) {
|
|
pfd = perf_event_open_probe(false /* uprobe */, retprobe,
|
|
func_name, offset,
|
|
-1 /* pid */, 0 /* ref_ctr_off */);
|
|
} else {
|
|
char probe_name[256];
|
|
|
|
gen_kprobe_legacy_event_name(probe_name, sizeof(probe_name),
|
|
func_name, offset);
|
|
|
|
legacy_probe = strdup(probe_name);
|
|
if (!legacy_probe)
|
|
return libbpf_err_ptr(-ENOMEM);
|
|
|
|
pfd = perf_event_kprobe_open_legacy(legacy_probe, retprobe, func_name,
|
|
offset, -1 /* pid */);
|
|
}
|
|
if (pfd < 0) {
|
|
err = -errno;
|
|
pr_warn("prog '%s': failed to create %s '%s+0x%zx' perf event: %s\n",
|
|
prog->name, retprobe ? "kretprobe" : "kprobe",
|
|
func_name, offset,
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
goto err_out;
|
|
}
|
|
link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts);
|
|
err = libbpf_get_error(link);
|
|
if (err) {
|
|
close(pfd);
|
|
pr_warn("prog '%s': failed to attach to %s '%s+0x%zx': %s\n",
|
|
prog->name, retprobe ? "kretprobe" : "kprobe",
|
|
func_name, offset,
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
goto err_out;
|
|
}
|
|
if (legacy) {
|
|
struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
|
|
|
|
perf_link->legacy_probe_name = legacy_probe;
|
|
perf_link->legacy_is_kprobe = true;
|
|
perf_link->legacy_is_retprobe = retprobe;
|
|
}
|
|
|
|
return link;
|
|
err_out:
|
|
free(legacy_probe);
|
|
return libbpf_err_ptr(err);
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog,
|
|
bool retprobe,
|
|
const char *func_name)
|
|
{
|
|
DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts,
|
|
.retprobe = retprobe,
|
|
);
|
|
|
|
return bpf_program__attach_kprobe_opts(prog, func_name, &opts);
|
|
}
|
|
|
|
/* Adapted from perf/util/string.c */
|
|
static bool glob_match(const char *str, const char *pat)
|
|
{
|
|
while (*str && *pat && *pat != '*') {
|
|
if (*pat == '?') { /* Matches any single character */
|
|
str++;
|
|
pat++;
|
|
continue;
|
|
}
|
|
if (*str != *pat)
|
|
return false;
|
|
str++;
|
|
pat++;
|
|
}
|
|
/* Check wild card */
|
|
if (*pat == '*') {
|
|
while (*pat == '*')
|
|
pat++;
|
|
if (!*pat) /* Tail wild card matches all */
|
|
return true;
|
|
while (*str)
|
|
if (glob_match(str++, pat))
|
|
return true;
|
|
}
|
|
return !*str && !*pat;
|
|
}
|
|
|
|
struct kprobe_multi_resolve {
|
|
const char *pattern;
|
|
unsigned long *addrs;
|
|
size_t cap;
|
|
size_t cnt;
|
|
};
|
|
|
|
static int
|
|
resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type,
|
|
const char *sym_name, void *ctx)
|
|
{
|
|
struct kprobe_multi_resolve *res = ctx;
|
|
int err;
|
|
|
|
if (!glob_match(sym_name, res->pattern))
|
|
return 0;
|
|
|
|
err = libbpf_ensure_mem((void **) &res->addrs, &res->cap, sizeof(unsigned long),
|
|
res->cnt + 1);
|
|
if (err)
|
|
return err;
|
|
|
|
res->addrs[res->cnt++] = (unsigned long) sym_addr;
|
|
return 0;
|
|
}
|
|
|
|
struct bpf_link *
|
|
bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
|
|
const char *pattern,
|
|
const struct bpf_kprobe_multi_opts *opts)
|
|
{
|
|
LIBBPF_OPTS(bpf_link_create_opts, lopts);
|
|
struct kprobe_multi_resolve res = {
|
|
.pattern = pattern,
|
|
};
|
|
struct bpf_link *link = NULL;
|
|
char errmsg[STRERR_BUFSIZE];
|
|
const unsigned long *addrs;
|
|
int err, link_fd, prog_fd;
|
|
const __u64 *cookies;
|
|
const char **syms;
|
|
bool retprobe;
|
|
size_t cnt;
|
|
|
|
if (!OPTS_VALID(opts, bpf_kprobe_multi_opts))
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
syms = OPTS_GET(opts, syms, false);
|
|
addrs = OPTS_GET(opts, addrs, false);
|
|
cnt = OPTS_GET(opts, cnt, false);
|
|
cookies = OPTS_GET(opts, cookies, false);
|
|
|
|
if (!pattern && !addrs && !syms)
|
|
return libbpf_err_ptr(-EINVAL);
|
|
if (pattern && (addrs || syms || cookies || cnt))
|
|
return libbpf_err_ptr(-EINVAL);
|
|
if (!pattern && !cnt)
|
|
return libbpf_err_ptr(-EINVAL);
|
|
if (addrs && syms)
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
if (pattern) {
|
|
err = libbpf_kallsyms_parse(resolve_kprobe_multi_cb, &res);
|
|
if (err)
|
|
goto error;
|
|
if (!res.cnt) {
|
|
err = -ENOENT;
|
|
goto error;
|
|
}
|
|
addrs = res.addrs;
|
|
cnt = res.cnt;
|
|
}
|
|
|
|
retprobe = OPTS_GET(opts, retprobe, false);
|
|
|
|
lopts.kprobe_multi.syms = syms;
|
|
lopts.kprobe_multi.addrs = addrs;
|
|
lopts.kprobe_multi.cookies = cookies;
|
|
lopts.kprobe_multi.cnt = cnt;
|
|
lopts.kprobe_multi.flags = retprobe ? BPF_F_KPROBE_MULTI_RETURN : 0;
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link) {
|
|
err = -ENOMEM;
|
|
goto error;
|
|
}
|
|
link->detach = &bpf_link__detach_fd;
|
|
|
|
prog_fd = bpf_program__fd(prog);
|
|
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_KPROBE_MULTI, &lopts);
|
|
if (link_fd < 0) {
|
|
err = -errno;
|
|
pr_warn("prog '%s': failed to attach: %s\n",
|
|
prog->name, libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
goto error;
|
|
}
|
|
link->fd = link_fd;
|
|
free(res.addrs);
|
|
return link;
|
|
|
|
error:
|
|
free(link);
|
|
free(res.addrs);
|
|
return libbpf_err_ptr(err);
|
|
}
|
|
|
|
static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link)
|
|
{
|
|
DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts);
|
|
unsigned long offset = 0;
|
|
const char *func_name;
|
|
char *func;
|
|
int n;
|
|
|
|
*link = NULL;
|
|
|
|
/* no auto-attach for SEC("kprobe") and SEC("kretprobe") */
|
|
if (strcmp(prog->sec_name, "kprobe") == 0 || strcmp(prog->sec_name, "kretprobe") == 0)
|
|
return 0;
|
|
|
|
opts.retprobe = str_has_pfx(prog->sec_name, "kretprobe/");
|
|
if (opts.retprobe)
|
|
func_name = prog->sec_name + sizeof("kretprobe/") - 1;
|
|
else
|
|
func_name = prog->sec_name + sizeof("kprobe/") - 1;
|
|
|
|
n = sscanf(func_name, "%m[a-zA-Z0-9_.]+%li", &func, &offset);
|
|
if (n < 1) {
|
|
pr_warn("kprobe name is invalid: %s\n", func_name);
|
|
return -EINVAL;
|
|
}
|
|
if (opts.retprobe && offset != 0) {
|
|
free(func);
|
|
pr_warn("kretprobes do not support offset specification\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
opts.offset = offset;
|
|
*link = bpf_program__attach_kprobe_opts(prog, func, &opts);
|
|
free(func);
|
|
return libbpf_get_error(*link);
|
|
}
|
|
|
|
static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link)
|
|
{
|
|
LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
|
|
const char *spec;
|
|
char *pattern;
|
|
int n;
|
|
|
|
*link = NULL;
|
|
|
|
/* no auto-attach for SEC("kprobe.multi") and SEC("kretprobe.multi") */
|
|
if (strcmp(prog->sec_name, "kprobe.multi") == 0 ||
|
|
strcmp(prog->sec_name, "kretprobe.multi") == 0)
|
|
return 0;
|
|
|
|
opts.retprobe = str_has_pfx(prog->sec_name, "kretprobe.multi/");
|
|
if (opts.retprobe)
|
|
spec = prog->sec_name + sizeof("kretprobe.multi/") - 1;
|
|
else
|
|
spec = prog->sec_name + sizeof("kprobe.multi/") - 1;
|
|
|
|
n = sscanf(spec, "%m[a-zA-Z0-9_.*?]", &pattern);
|
|
if (n < 1) {
|
|
pr_warn("kprobe multi pattern is invalid: %s\n", pattern);
|
|
return -EINVAL;
|
|
}
|
|
|
|
*link = bpf_program__attach_kprobe_multi_opts(prog, pattern, &opts);
|
|
free(pattern);
|
|
return libbpf_get_error(*link);
|
|
}
|
|
|
|
static void gen_uprobe_legacy_event_name(char *buf, size_t buf_sz,
|
|
const char *binary_path, uint64_t offset)
|
|
{
|
|
int i;
|
|
|
|
snprintf(buf, buf_sz, "libbpf_%u_%s_0x%zx", getpid(), binary_path, (size_t)offset);
|
|
|
|
/* sanitize binary_path in the probe name */
|
|
for (i = 0; buf[i]; i++) {
|
|
if (!isalnum(buf[i]))
|
|
buf[i] = '_';
|
|
}
|
|
}
|
|
|
|
static inline int add_uprobe_event_legacy(const char *probe_name, bool retprobe,
|
|
const char *binary_path, size_t offset)
|
|
{
|
|
const char *file = "/sys/kernel/debug/tracing/uprobe_events";
|
|
|
|
return append_to_file(file, "%c:%s/%s %s:0x%zx",
|
|
retprobe ? 'r' : 'p',
|
|
retprobe ? "uretprobes" : "uprobes",
|
|
probe_name, binary_path, offset);
|
|
}
|
|
|
|
static inline int remove_uprobe_event_legacy(const char *probe_name, bool retprobe)
|
|
{
|
|
const char *file = "/sys/kernel/debug/tracing/uprobe_events";
|
|
|
|
return append_to_file(file, "-:%s/%s", retprobe ? "uretprobes" : "uprobes", probe_name);
|
|
}
|
|
|
|
static int determine_uprobe_perf_type_legacy(const char *probe_name, bool retprobe)
|
|
{
|
|
char file[512];
|
|
|
|
snprintf(file, sizeof(file),
|
|
"/sys/kernel/debug/tracing/events/%s/%s/id",
|
|
retprobe ? "uretprobes" : "uprobes", probe_name);
|
|
|
|
return parse_uint_from_file(file, "%d\n");
|
|
}
|
|
|
|
static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe,
|
|
const char *binary_path, size_t offset, int pid)
|
|
{
|
|
struct perf_event_attr attr;
|
|
int type, pfd, err;
|
|
|
|
err = add_uprobe_event_legacy(probe_name, retprobe, binary_path, offset);
|
|
if (err < 0) {
|
|
pr_warn("failed to add legacy uprobe event for %s:0x%zx: %d\n",
|
|
binary_path, (size_t)offset, err);
|
|
return err;
|
|
}
|
|
type = determine_uprobe_perf_type_legacy(probe_name, retprobe);
|
|
if (type < 0) {
|
|
pr_warn("failed to determine legacy uprobe event id for %s:0x%zx: %d\n",
|
|
binary_path, offset, err);
|
|
return type;
|
|
}
|
|
|
|
memset(&attr, 0, sizeof(attr));
|
|
attr.size = sizeof(attr);
|
|
attr.config = type;
|
|
attr.type = PERF_TYPE_TRACEPOINT;
|
|
|
|
pfd = syscall(__NR_perf_event_open, &attr,
|
|
pid < 0 ? -1 : pid, /* pid */
|
|
pid == -1 ? 0 : -1, /* cpu */
|
|
-1 /* group_fd */, PERF_FLAG_FD_CLOEXEC);
|
|
if (pfd < 0) {
|
|
err = -errno;
|
|
pr_warn("legacy uprobe perf_event_open() failed: %d\n", err);
|
|
return err;
|
|
}
|
|
return pfd;
|
|
}
|
|
|
|
/* uprobes deal in relative offsets; subtract the base address associated with
|
|
* the mapped binary. See Documentation/trace/uprobetracer.rst for more
|
|
* details.
|
|
*/
|
|
static long elf_find_relative_offset(const char *filename, Elf *elf, long addr)
|
|
{
|
|
size_t n;
|
|
int i;
|
|
|
|
if (elf_getphdrnum(elf, &n)) {
|
|
pr_warn("elf: failed to find program headers for '%s': %s\n", filename,
|
|
elf_errmsg(-1));
|
|
return -ENOENT;
|
|
}
|
|
|
|
for (i = 0; i < n; i++) {
|
|
int seg_start, seg_end, seg_offset;
|
|
GElf_Phdr phdr;
|
|
|
|
if (!gelf_getphdr(elf, i, &phdr)) {
|
|
pr_warn("elf: failed to get program header %d from '%s': %s\n", i, filename,
|
|
elf_errmsg(-1));
|
|
return -ENOENT;
|
|
}
|
|
if (phdr.p_type != PT_LOAD || !(phdr.p_flags & PF_X))
|
|
continue;
|
|
|
|
seg_start = phdr.p_vaddr;
|
|
seg_end = seg_start + phdr.p_memsz;
|
|
seg_offset = phdr.p_offset;
|
|
if (addr >= seg_start && addr < seg_end)
|
|
return addr - seg_start + seg_offset;
|
|
}
|
|
pr_warn("elf: failed to find prog header containing 0x%lx in '%s'\n", addr, filename);
|
|
return -ENOENT;
|
|
}
|
|
|
|
/* Return next ELF section of sh_type after scn, or first of that type if scn is NULL. */
|
|
static Elf_Scn *elf_find_next_scn_by_type(Elf *elf, int sh_type, Elf_Scn *scn)
|
|
{
|
|
while ((scn = elf_nextscn(elf, scn)) != NULL) {
|
|
GElf_Shdr sh;
|
|
|
|
if (!gelf_getshdr(scn, &sh))
|
|
continue;
|
|
if (sh.sh_type == sh_type)
|
|
return scn;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Find offset of function name in object specified by path. "name" matches
|
|
* symbol name or name@@LIB for library functions.
|
|
*/
|
|
static long elf_find_func_offset(const char *binary_path, const char *name)
|
|
{
|
|
int fd, i, sh_types[2] = { SHT_DYNSYM, SHT_SYMTAB };
|
|
bool is_shared_lib, is_name_qualified;
|
|
char errmsg[STRERR_BUFSIZE];
|
|
long ret = -ENOENT;
|
|
size_t name_len;
|
|
GElf_Ehdr ehdr;
|
|
Elf *elf;
|
|
|
|
fd = open(binary_path, O_RDONLY | O_CLOEXEC);
|
|
if (fd < 0) {
|
|
ret = -errno;
|
|
pr_warn("failed to open %s: %s\n", binary_path,
|
|
libbpf_strerror_r(ret, errmsg, sizeof(errmsg)));
|
|
return ret;
|
|
}
|
|
elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
|
|
if (!elf) {
|
|
pr_warn("elf: could not read elf from %s: %s\n", binary_path, elf_errmsg(-1));
|
|
close(fd);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
if (!gelf_getehdr(elf, &ehdr)) {
|
|
pr_warn("elf: failed to get ehdr from %s: %s\n", binary_path, elf_errmsg(-1));
|
|
ret = -LIBBPF_ERRNO__FORMAT;
|
|
goto out;
|
|
}
|
|
/* for shared lib case, we do not need to calculate relative offset */
|
|
is_shared_lib = ehdr.e_type == ET_DYN;
|
|
|
|
name_len = strlen(name);
|
|
/* Does name specify "@@LIB"? */
|
|
is_name_qualified = strstr(name, "@@") != NULL;
|
|
|
|
/* Search SHT_DYNSYM, SHT_SYMTAB for symbol. This search order is used because if
|
|
* a binary is stripped, it may only have SHT_DYNSYM, and a fully-statically
|
|
* linked binary may not have SHT_DYMSYM, so absence of a section should not be
|
|
* reported as a warning/error.
|
|
*/
|
|
for (i = 0; i < ARRAY_SIZE(sh_types); i++) {
|
|
size_t nr_syms, strtabidx, idx;
|
|
Elf_Data *symbols = NULL;
|
|
Elf_Scn *scn = NULL;
|
|
int last_bind = -1;
|
|
const char *sname;
|
|
GElf_Shdr sh;
|
|
|
|
scn = elf_find_next_scn_by_type(elf, sh_types[i], NULL);
|
|
if (!scn) {
|
|
pr_debug("elf: failed to find symbol table ELF sections in '%s'\n",
|
|
binary_path);
|
|
continue;
|
|
}
|
|
if (!gelf_getshdr(scn, &sh))
|
|
continue;
|
|
strtabidx = sh.sh_link;
|
|
symbols = elf_getdata(scn, 0);
|
|
if (!symbols) {
|
|
pr_warn("elf: failed to get symbols for symtab section in '%s': %s\n",
|
|
binary_path, elf_errmsg(-1));
|
|
ret = -LIBBPF_ERRNO__FORMAT;
|
|
goto out;
|
|
}
|
|
nr_syms = symbols->d_size / sh.sh_entsize;
|
|
|
|
for (idx = 0; idx < nr_syms; idx++) {
|
|
int curr_bind;
|
|
GElf_Sym sym;
|
|
|
|
if (!gelf_getsym(symbols, idx, &sym))
|
|
continue;
|
|
|
|
if (GELF_ST_TYPE(sym.st_info) != STT_FUNC)
|
|
continue;
|
|
|
|
sname = elf_strptr(elf, strtabidx, sym.st_name);
|
|
if (!sname)
|
|
continue;
|
|
|
|
curr_bind = GELF_ST_BIND(sym.st_info);
|
|
|
|
/* User can specify func, func@@LIB or func@@LIB_VERSION. */
|
|
if (strncmp(sname, name, name_len) != 0)
|
|
continue;
|
|
/* ...but we don't want a search for "foo" to match 'foo2" also, so any
|
|
* additional characters in sname should be of the form "@@LIB".
|
|
*/
|
|
if (!is_name_qualified && sname[name_len] != '\0' && sname[name_len] != '@')
|
|
continue;
|
|
|
|
if (ret >= 0) {
|
|
/* handle multiple matches */
|
|
if (last_bind != STB_WEAK && curr_bind != STB_WEAK) {
|
|
/* Only accept one non-weak bind. */
|
|
pr_warn("elf: ambiguous match for '%s', '%s' in '%s'\n",
|
|
sname, name, binary_path);
|
|
ret = -LIBBPF_ERRNO__FORMAT;
|
|
goto out;
|
|
} else if (curr_bind == STB_WEAK) {
|
|
/* already have a non-weak bind, and
|
|
* this is a weak bind, so ignore.
|
|
*/
|
|
continue;
|
|
}
|
|
}
|
|
ret = sym.st_value;
|
|
last_bind = curr_bind;
|
|
}
|
|
/* For binaries that are not shared libraries, we need relative offset */
|
|
if (ret > 0 && !is_shared_lib)
|
|
ret = elf_find_relative_offset(binary_path, elf, ret);
|
|
if (ret > 0)
|
|
break;
|
|
}
|
|
|
|
if (ret > 0) {
|
|
pr_debug("elf: symbol address match for '%s' in '%s': 0x%lx\n", name, binary_path,
|
|
ret);
|
|
} else {
|
|
if (ret == 0) {
|
|
pr_warn("elf: '%s' is 0 in symtab for '%s': %s\n", name, binary_path,
|
|
is_shared_lib ? "should not be 0 in a shared library" :
|
|
"try using shared library path instead");
|
|
ret = -ENOENT;
|
|
} else {
|
|
pr_warn("elf: failed to find symbol '%s' in '%s'\n", name, binary_path);
|
|
}
|
|
}
|
|
out:
|
|
elf_end(elf);
|
|
close(fd);
|
|
return ret;
|
|
}
|
|
|
|
static const char *arch_specific_lib_paths(void)
|
|
{
|
|
/*
|
|
* Based on https://packages.debian.org/sid/libc6.
|
|
*
|
|
* Assume that the traced program is built for the same architecture
|
|
* as libbpf, which should cover the vast majority of cases.
|
|
*/
|
|
#if defined(__x86_64__)
|
|
return "/lib/x86_64-linux-gnu";
|
|
#elif defined(__i386__)
|
|
return "/lib/i386-linux-gnu";
|
|
#elif defined(__s390x__)
|
|
return "/lib/s390x-linux-gnu";
|
|
#elif defined(__s390__)
|
|
return "/lib/s390-linux-gnu";
|
|
#elif defined(__arm__) && defined(__SOFTFP__)
|
|
return "/lib/arm-linux-gnueabi";
|
|
#elif defined(__arm__) && !defined(__SOFTFP__)
|
|
return "/lib/arm-linux-gnueabihf";
|
|
#elif defined(__aarch64__)
|
|
return "/lib/aarch64-linux-gnu";
|
|
#elif defined(__mips__) && defined(__MIPSEL__) && _MIPS_SZLONG == 64
|
|
return "/lib/mips64el-linux-gnuabi64";
|
|
#elif defined(__mips__) && defined(__MIPSEL__) && _MIPS_SZLONG == 32
|
|
return "/lib/mipsel-linux-gnu";
|
|
#elif defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
|
|
return "/lib/powerpc64le-linux-gnu";
|
|
#elif defined(__sparc__) && defined(__arch64__)
|
|
return "/lib/sparc64-linux-gnu";
|
|
#elif defined(__riscv) && __riscv_xlen == 64
|
|
return "/lib/riscv64-linux-gnu";
|
|
#else
|
|
return NULL;
|
|
#endif
|
|
}
|
|
|
|
/* Get full path to program/shared library. */
|
|
static int resolve_full_path(const char *file, char *result, size_t result_sz)
|
|
{
|
|
const char *search_paths[3] = {};
|
|
int i;
|
|
|
|
if (str_has_sfx(file, ".so") || strstr(file, ".so.")) {
|
|
search_paths[0] = getenv("LD_LIBRARY_PATH");
|
|
search_paths[1] = "/usr/lib64:/usr/lib";
|
|
search_paths[2] = arch_specific_lib_paths();
|
|
} else {
|
|
search_paths[0] = getenv("PATH");
|
|
search_paths[1] = "/usr/bin:/usr/sbin";
|
|
}
|
|
|
|
for (i = 0; i < ARRAY_SIZE(search_paths); i++) {
|
|
const char *s;
|
|
|
|
if (!search_paths[i])
|
|
continue;
|
|
for (s = search_paths[i]; s != NULL; s = strchr(s, ':')) {
|
|
char *next_path;
|
|
int seg_len;
|
|
|
|
if (s[0] == ':')
|
|
s++;
|
|
next_path = strchr(s, ':');
|
|
seg_len = next_path ? next_path - s : strlen(s);
|
|
if (!seg_len)
|
|
continue;
|
|
snprintf(result, result_sz, "%.*s/%s", seg_len, s, file);
|
|
/* ensure it is an executable file/link */
|
|
if (access(result, R_OK | X_OK) < 0)
|
|
continue;
|
|
pr_debug("resolved '%s' to '%s'\n", file, result);
|
|
return 0;
|
|
}
|
|
}
|
|
return -ENOENT;
|
|
}
|
|
|
|
LIBBPF_API struct bpf_link *
|
|
bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
|
|
const char *binary_path, size_t func_offset,
|
|
const struct bpf_uprobe_opts *opts)
|
|
{
|
|
DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts);
|
|
char errmsg[STRERR_BUFSIZE], *legacy_probe = NULL;
|
|
char full_binary_path[PATH_MAX];
|
|
struct bpf_link *link;
|
|
size_t ref_ctr_off;
|
|
int pfd, err;
|
|
bool retprobe, legacy;
|
|
const char *func_name;
|
|
|
|
if (!OPTS_VALID(opts, bpf_uprobe_opts))
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
retprobe = OPTS_GET(opts, retprobe, false);
|
|
ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0);
|
|
pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
|
|
|
|
if (binary_path && !strchr(binary_path, '/')) {
|
|
err = resolve_full_path(binary_path, full_binary_path,
|
|
sizeof(full_binary_path));
|
|
if (err) {
|
|
pr_warn("prog '%s': failed to resolve full path for '%s': %d\n",
|
|
prog->name, binary_path, err);
|
|
return libbpf_err_ptr(err);
|
|
}
|
|
binary_path = full_binary_path;
|
|
}
|
|
func_name = OPTS_GET(opts, func_name, NULL);
|
|
if (func_name) {
|
|
long sym_off;
|
|
|
|
if (!binary_path) {
|
|
pr_warn("prog '%s': name-based attach requires binary_path\n",
|
|
prog->name);
|
|
return libbpf_err_ptr(-EINVAL);
|
|
}
|
|
sym_off = elf_find_func_offset(binary_path, func_name);
|
|
if (sym_off < 0)
|
|
return libbpf_err_ptr(sym_off);
|
|
func_offset += sym_off;
|
|
}
|
|
|
|
legacy = determine_uprobe_perf_type() < 0;
|
|
if (!legacy) {
|
|
pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path,
|
|
func_offset, pid, ref_ctr_off);
|
|
} else {
|
|
char probe_name[PATH_MAX + 64];
|
|
|
|
if (ref_ctr_off)
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
gen_uprobe_legacy_event_name(probe_name, sizeof(probe_name),
|
|
binary_path, func_offset);
|
|
|
|
legacy_probe = strdup(probe_name);
|
|
if (!legacy_probe)
|
|
return libbpf_err_ptr(-ENOMEM);
|
|
|
|
pfd = perf_event_uprobe_open_legacy(legacy_probe, retprobe,
|
|
binary_path, func_offset, pid);
|
|
}
|
|
if (pfd < 0) {
|
|
err = -errno;
|
|
pr_warn("prog '%s': failed to create %s '%s:0x%zx' perf event: %s\n",
|
|
prog->name, retprobe ? "uretprobe" : "uprobe",
|
|
binary_path, func_offset,
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
goto err_out;
|
|
}
|
|
|
|
link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts);
|
|
err = libbpf_get_error(link);
|
|
if (err) {
|
|
close(pfd);
|
|
pr_warn("prog '%s': failed to attach to %s '%s:0x%zx': %s\n",
|
|
prog->name, retprobe ? "uretprobe" : "uprobe",
|
|
binary_path, func_offset,
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
goto err_out;
|
|
}
|
|
if (legacy) {
|
|
struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
|
|
|
|
perf_link->legacy_probe_name = legacy_probe;
|
|
perf_link->legacy_is_kprobe = false;
|
|
perf_link->legacy_is_retprobe = retprobe;
|
|
}
|
|
return link;
|
|
err_out:
|
|
free(legacy_probe);
|
|
return libbpf_err_ptr(err);
|
|
|
|
}
|
|
|
|
/* Format of u[ret]probe section definition supporting auto-attach:
|
|
* u[ret]probe/binary:function[+offset]
|
|
*
|
|
* binary can be an absolute/relative path or a filename; the latter is resolved to a
|
|
* full binary path via bpf_program__attach_uprobe_opts.
|
|
*
|
|
* Specifying uprobe+ ensures we carry out strict matching; either "uprobe" must be
|
|
* specified (and auto-attach is not possible) or the above format is specified for
|
|
* auto-attach.
|
|
*/
|
|
static int attach_uprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link)
|
|
{
|
|
DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts);
|
|
char *probe_type = NULL, *binary_path = NULL, *func_name = NULL;
|
|
int n, ret = -EINVAL;
|
|
long offset = 0;
|
|
|
|
*link = NULL;
|
|
|
|
n = sscanf(prog->sec_name, "%m[^/]/%m[^:]:%m[a-zA-Z0-9_.]+%li",
|
|
&probe_type, &binary_path, &func_name, &offset);
|
|
switch (n) {
|
|
case 1:
|
|
/* handle SEC("u[ret]probe") - format is valid, but auto-attach is impossible. */
|
|
ret = 0;
|
|
break;
|
|
case 2:
|
|
pr_warn("prog '%s': section '%s' missing ':function[+offset]' specification\n",
|
|
prog->name, prog->sec_name);
|
|
break;
|
|
case 3:
|
|
case 4:
|
|
opts.retprobe = strcmp(probe_type, "uretprobe") == 0;
|
|
if (opts.retprobe && offset != 0) {
|
|
pr_warn("prog '%s': uretprobes do not support offset specification\n",
|
|
prog->name);
|
|
break;
|
|
}
|
|
opts.func_name = func_name;
|
|
*link = bpf_program__attach_uprobe_opts(prog, -1, binary_path, offset, &opts);
|
|
ret = libbpf_get_error(*link);
|
|
break;
|
|
default:
|
|
pr_warn("prog '%s': invalid format of section definition '%s'\n", prog->name,
|
|
prog->sec_name);
|
|
break;
|
|
}
|
|
free(probe_type);
|
|
free(binary_path);
|
|
free(func_name);
|
|
|
|
return ret;
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_uprobe(const struct bpf_program *prog,
|
|
bool retprobe, pid_t pid,
|
|
const char *binary_path,
|
|
size_t func_offset)
|
|
{
|
|
DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts, .retprobe = retprobe);
|
|
|
|
return bpf_program__attach_uprobe_opts(prog, pid, binary_path, func_offset, &opts);
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_usdt(const struct bpf_program *prog,
|
|
pid_t pid, const char *binary_path,
|
|
const char *usdt_provider, const char *usdt_name,
|
|
const struct bpf_usdt_opts *opts)
|
|
{
|
|
char resolved_path[512];
|
|
struct bpf_object *obj = prog->obj;
|
|
struct bpf_link *link;
|
|
__u64 usdt_cookie;
|
|
int err;
|
|
|
|
if (!OPTS_VALID(opts, bpf_uprobe_opts))
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
if (bpf_program__fd(prog) < 0) {
|
|
pr_warn("prog '%s': can't attach BPF program w/o FD (did you load it?)\n",
|
|
prog->name);
|
|
return libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
if (!strchr(binary_path, '/')) {
|
|
err = resolve_full_path(binary_path, resolved_path, sizeof(resolved_path));
|
|
if (err) {
|
|
pr_warn("prog '%s': failed to resolve full path for '%s': %d\n",
|
|
prog->name, binary_path, err);
|
|
return libbpf_err_ptr(err);
|
|
}
|
|
binary_path = resolved_path;
|
|
}
|
|
|
|
/* USDT manager is instantiated lazily on first USDT attach. It will
|
|
* be destroyed together with BPF object in bpf_object__close().
|
|
*/
|
|
if (IS_ERR(obj->usdt_man))
|
|
return libbpf_ptr(obj->usdt_man);
|
|
if (!obj->usdt_man) {
|
|
obj->usdt_man = usdt_manager_new(obj);
|
|
if (IS_ERR(obj->usdt_man))
|
|
return libbpf_ptr(obj->usdt_man);
|
|
}
|
|
|
|
usdt_cookie = OPTS_GET(opts, usdt_cookie, 0);
|
|
link = usdt_manager_attach_usdt(obj->usdt_man, prog, pid, binary_path,
|
|
usdt_provider, usdt_name, usdt_cookie);
|
|
err = libbpf_get_error(link);
|
|
if (err)
|
|
return libbpf_err_ptr(err);
|
|
return link;
|
|
}
|
|
|
|
static int attach_usdt(const struct bpf_program *prog, long cookie, struct bpf_link **link)
|
|
{
|
|
char *path = NULL, *provider = NULL, *name = NULL;
|
|
const char *sec_name;
|
|
int n, err;
|
|
|
|
sec_name = bpf_program__section_name(prog);
|
|
if (strcmp(sec_name, "usdt") == 0) {
|
|
/* no auto-attach for just SEC("usdt") */
|
|
*link = NULL;
|
|
return 0;
|
|
}
|
|
|
|
n = sscanf(sec_name, "usdt/%m[^:]:%m[^:]:%m[^:]", &path, &provider, &name);
|
|
if (n != 3) {
|
|
pr_warn("invalid section '%s', expected SEC(\"usdt/<path>:<provider>:<name>\")\n",
|
|
sec_name);
|
|
err = -EINVAL;
|
|
} else {
|
|
*link = bpf_program__attach_usdt(prog, -1 /* any process */, path,
|
|
provider, name, NULL);
|
|
err = libbpf_get_error(*link);
|
|
}
|
|
free(path);
|
|
free(provider);
|
|
free(name);
|
|
return err;
|
|
}
|
|
|
|
static int determine_tracepoint_id(const char *tp_category,
|
|
const char *tp_name)
|
|
{
|
|
char file[PATH_MAX];
|
|
int ret;
|
|
|
|
ret = snprintf(file, sizeof(file),
|
|
"/sys/kernel/debug/tracing/events/%s/%s/id",
|
|
tp_category, tp_name);
|
|
if (ret < 0)
|
|
return -errno;
|
|
if (ret >= sizeof(file)) {
|
|
pr_debug("tracepoint %s/%s path is too long\n",
|
|
tp_category, tp_name);
|
|
return -E2BIG;
|
|
}
|
|
return parse_uint_from_file(file, "%d\n");
|
|
}
|
|
|
|
static int perf_event_open_tracepoint(const char *tp_category,
|
|
const char *tp_name)
|
|
{
|
|
struct perf_event_attr attr = {};
|
|
char errmsg[STRERR_BUFSIZE];
|
|
int tp_id, pfd, err;
|
|
|
|
tp_id = determine_tracepoint_id(tp_category, tp_name);
|
|
if (tp_id < 0) {
|
|
pr_warn("failed to determine tracepoint '%s/%s' perf event ID: %s\n",
|
|
tp_category, tp_name,
|
|
libbpf_strerror_r(tp_id, errmsg, sizeof(errmsg)));
|
|
return tp_id;
|
|
}
|
|
|
|
attr.type = PERF_TYPE_TRACEPOINT;
|
|
attr.size = sizeof(attr);
|
|
attr.config = tp_id;
|
|
|
|
pfd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, 0 /* cpu */,
|
|
-1 /* group_fd */, PERF_FLAG_FD_CLOEXEC);
|
|
if (pfd < 0) {
|
|
err = -errno;
|
|
pr_warn("tracepoint '%s/%s' perf_event_open() failed: %s\n",
|
|
tp_category, tp_name,
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
return err;
|
|
}
|
|
return pfd;
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
|
|
const char *tp_category,
|
|
const char *tp_name,
|
|
const struct bpf_tracepoint_opts *opts)
|
|
{
|
|
DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts);
|
|
char errmsg[STRERR_BUFSIZE];
|
|
struct bpf_link *link;
|
|
int pfd, err;
|
|
|
|
if (!OPTS_VALID(opts, bpf_tracepoint_opts))
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
|
|
|
|
pfd = perf_event_open_tracepoint(tp_category, tp_name);
|
|
if (pfd < 0) {
|
|
pr_warn("prog '%s': failed to create tracepoint '%s/%s' perf event: %s\n",
|
|
prog->name, tp_category, tp_name,
|
|
libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
|
|
return libbpf_err_ptr(pfd);
|
|
}
|
|
link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts);
|
|
err = libbpf_get_error(link);
|
|
if (err) {
|
|
close(pfd);
|
|
pr_warn("prog '%s': failed to attach to tracepoint '%s/%s': %s\n",
|
|
prog->name, tp_category, tp_name,
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
return libbpf_err_ptr(err);
|
|
}
|
|
return link;
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_tracepoint(const struct bpf_program *prog,
|
|
const char *tp_category,
|
|
const char *tp_name)
|
|
{
|
|
return bpf_program__attach_tracepoint_opts(prog, tp_category, tp_name, NULL);
|
|
}
|
|
|
|
static int attach_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link)
|
|
{
|
|
char *sec_name, *tp_cat, *tp_name;
|
|
|
|
*link = NULL;
|
|
|
|
/* no auto-attach for SEC("tp") or SEC("tracepoint") */
|
|
if (strcmp(prog->sec_name, "tp") == 0 || strcmp(prog->sec_name, "tracepoint") == 0)
|
|
return 0;
|
|
|
|
sec_name = strdup(prog->sec_name);
|
|
if (!sec_name)
|
|
return -ENOMEM;
|
|
|
|
/* extract "tp/<category>/<name>" or "tracepoint/<category>/<name>" */
|
|
if (str_has_pfx(prog->sec_name, "tp/"))
|
|
tp_cat = sec_name + sizeof("tp/") - 1;
|
|
else
|
|
tp_cat = sec_name + sizeof("tracepoint/") - 1;
|
|
tp_name = strchr(tp_cat, '/');
|
|
if (!tp_name) {
|
|
free(sec_name);
|
|
return -EINVAL;
|
|
}
|
|
*tp_name = '\0';
|
|
tp_name++;
|
|
|
|
*link = bpf_program__attach_tracepoint(prog, tp_cat, tp_name);
|
|
free(sec_name);
|
|
return libbpf_get_error(*link);
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
|
|
const char *tp_name)
|
|
{
|
|
char errmsg[STRERR_BUFSIZE];
|
|
struct bpf_link *link;
|
|
int prog_fd, pfd;
|
|
|
|
prog_fd = bpf_program__fd(prog);
|
|
if (prog_fd < 0) {
|
|
pr_warn("prog '%s': can't attach before loaded\n", prog->name);
|
|
return libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link)
|
|
return libbpf_err_ptr(-ENOMEM);
|
|
link->detach = &bpf_link__detach_fd;
|
|
|
|
pfd = bpf_raw_tracepoint_open(tp_name, prog_fd);
|
|
if (pfd < 0) {
|
|
pfd = -errno;
|
|
free(link);
|
|
pr_warn("prog '%s': failed to attach to raw tracepoint '%s': %s\n",
|
|
prog->name, tp_name, libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
|
|
return libbpf_err_ptr(pfd);
|
|
}
|
|
link->fd = pfd;
|
|
return link;
|
|
}
|
|
|
|
static int attach_raw_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link)
|
|
{
|
|
static const char *const prefixes[] = {
|
|
"raw_tp",
|
|
"raw_tracepoint",
|
|
"raw_tp.w",
|
|
"raw_tracepoint.w",
|
|
};
|
|
size_t i;
|
|
const char *tp_name = NULL;
|
|
|
|
*link = NULL;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
|
|
size_t pfx_len;
|
|
|
|
if (!str_has_pfx(prog->sec_name, prefixes[i]))
|
|
continue;
|
|
|
|
pfx_len = strlen(prefixes[i]);
|
|
/* no auto-attach case of, e.g., SEC("raw_tp") */
|
|
if (prog->sec_name[pfx_len] == '\0')
|
|
return 0;
|
|
|
|
if (prog->sec_name[pfx_len] != '/')
|
|
continue;
|
|
|
|
tp_name = prog->sec_name + pfx_len + 1;
|
|
break;
|
|
}
|
|
|
|
if (!tp_name) {
|
|
pr_warn("prog '%s': invalid section name '%s'\n",
|
|
prog->name, prog->sec_name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
*link = bpf_program__attach_raw_tracepoint(prog, tp_name);
|
|
return libbpf_get_error(link);
|
|
}
|
|
|
|
/* Common logic for all BPF program types that attach to a btf_id */
|
|
static struct bpf_link *bpf_program__attach_btf_id(const struct bpf_program *prog,
|
|
const struct bpf_trace_opts *opts)
|
|
{
|
|
LIBBPF_OPTS(bpf_link_create_opts, link_opts);
|
|
char errmsg[STRERR_BUFSIZE];
|
|
struct bpf_link *link;
|
|
int prog_fd, pfd;
|
|
|
|
if (!OPTS_VALID(opts, bpf_trace_opts))
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
prog_fd = bpf_program__fd(prog);
|
|
if (prog_fd < 0) {
|
|
pr_warn("prog '%s': can't attach before loaded\n", prog->name);
|
|
return libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link)
|
|
return libbpf_err_ptr(-ENOMEM);
|
|
link->detach = &bpf_link__detach_fd;
|
|
|
|
/* libbpf is smart enough to redirect to BPF_RAW_TRACEPOINT_OPEN on old kernels */
|
|
link_opts.tracing.cookie = OPTS_GET(opts, cookie, 0);
|
|
pfd = bpf_link_create(prog_fd, 0, bpf_program__expected_attach_type(prog), &link_opts);
|
|
if (pfd < 0) {
|
|
pfd = -errno;
|
|
free(link);
|
|
pr_warn("prog '%s': failed to attach: %s\n",
|
|
prog->name, libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
|
|
return libbpf_err_ptr(pfd);
|
|
}
|
|
link->fd = pfd;
|
|
return link;
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_trace(const struct bpf_program *prog)
|
|
{
|
|
return bpf_program__attach_btf_id(prog, NULL);
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_trace_opts(const struct bpf_program *prog,
|
|
const struct bpf_trace_opts *opts)
|
|
{
|
|
return bpf_program__attach_btf_id(prog, opts);
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_lsm(const struct bpf_program *prog)
|
|
{
|
|
return bpf_program__attach_btf_id(prog, NULL);
|
|
}
|
|
|
|
static int attach_trace(const struct bpf_program *prog, long cookie, struct bpf_link **link)
|
|
{
|
|
*link = bpf_program__attach_trace(prog);
|
|
return libbpf_get_error(*link);
|
|
}
|
|
|
|
static int attach_lsm(const struct bpf_program *prog, long cookie, struct bpf_link **link)
|
|
{
|
|
*link = bpf_program__attach_lsm(prog);
|
|
return libbpf_get_error(*link);
|
|
}
|
|
|
|
static struct bpf_link *
|
|
bpf_program__attach_fd(const struct bpf_program *prog, int target_fd, int btf_id,
|
|
const char *target_name)
|
|
{
|
|
DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts,
|
|
.target_btf_id = btf_id);
|
|
enum bpf_attach_type attach_type;
|
|
char errmsg[STRERR_BUFSIZE];
|
|
struct bpf_link *link;
|
|
int prog_fd, link_fd;
|
|
|
|
prog_fd = bpf_program__fd(prog);
|
|
if (prog_fd < 0) {
|
|
pr_warn("prog '%s': can't attach before loaded\n", prog->name);
|
|
return libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link)
|
|
return libbpf_err_ptr(-ENOMEM);
|
|
link->detach = &bpf_link__detach_fd;
|
|
|
|
attach_type = bpf_program__expected_attach_type(prog);
|
|
link_fd = bpf_link_create(prog_fd, target_fd, attach_type, &opts);
|
|
if (link_fd < 0) {
|
|
link_fd = -errno;
|
|
free(link);
|
|
pr_warn("prog '%s': failed to attach to %s: %s\n",
|
|
prog->name, target_name,
|
|
libbpf_strerror_r(link_fd, errmsg, sizeof(errmsg)));
|
|
return libbpf_err_ptr(link_fd);
|
|
}
|
|
link->fd = link_fd;
|
|
return link;
|
|
}
|
|
|
|
struct bpf_link *
|
|
bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd)
|
|
{
|
|
return bpf_program__attach_fd(prog, cgroup_fd, 0, "cgroup");
|
|
}
|
|
|
|
struct bpf_link *
|
|
bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd)
|
|
{
|
|
return bpf_program__attach_fd(prog, netns_fd, 0, "netns");
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex)
|
|
{
|
|
/* target_fd/target_ifindex use the same field in LINK_CREATE */
|
|
return bpf_program__attach_fd(prog, ifindex, 0, "xdp");
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_freplace(const struct bpf_program *prog,
|
|
int target_fd,
|
|
const char *attach_func_name)
|
|
{
|
|
int btf_id;
|
|
|
|
if (!!target_fd != !!attach_func_name) {
|
|
pr_warn("prog '%s': supply none or both of target_fd and attach_func_name\n",
|
|
prog->name);
|
|
return libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
if (prog->type != BPF_PROG_TYPE_EXT) {
|
|
pr_warn("prog '%s': only BPF_PROG_TYPE_EXT can attach as freplace",
|
|
prog->name);
|
|
return libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
if (target_fd) {
|
|
btf_id = libbpf_find_prog_btf_id(attach_func_name, target_fd);
|
|
if (btf_id < 0)
|
|
return libbpf_err_ptr(btf_id);
|
|
|
|
return bpf_program__attach_fd(prog, target_fd, btf_id, "freplace");
|
|
} else {
|
|
/* no target, so use raw_tracepoint_open for compatibility
|
|
* with old kernels
|
|
*/
|
|
return bpf_program__attach_trace(prog);
|
|
}
|
|
}
|
|
|
|
struct bpf_link *
|
|
bpf_program__attach_iter(const struct bpf_program *prog,
|
|
const struct bpf_iter_attach_opts *opts)
|
|
{
|
|
DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_create_opts);
|
|
char errmsg[STRERR_BUFSIZE];
|
|
struct bpf_link *link;
|
|
int prog_fd, link_fd;
|
|
__u32 target_fd = 0;
|
|
|
|
if (!OPTS_VALID(opts, bpf_iter_attach_opts))
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
link_create_opts.iter_info = OPTS_GET(opts, link_info, (void *)0);
|
|
link_create_opts.iter_info_len = OPTS_GET(opts, link_info_len, 0);
|
|
|
|
prog_fd = bpf_program__fd(prog);
|
|
if (prog_fd < 0) {
|
|
pr_warn("prog '%s': can't attach before loaded\n", prog->name);
|
|
return libbpf_err_ptr(-EINVAL);
|
|
}
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link)
|
|
return libbpf_err_ptr(-ENOMEM);
|
|
link->detach = &bpf_link__detach_fd;
|
|
|
|
link_fd = bpf_link_create(prog_fd, target_fd, BPF_TRACE_ITER,
|
|
&link_create_opts);
|
|
if (link_fd < 0) {
|
|
link_fd = -errno;
|
|
free(link);
|
|
pr_warn("prog '%s': failed to attach to iterator: %s\n",
|
|
prog->name, libbpf_strerror_r(link_fd, errmsg, sizeof(errmsg)));
|
|
return libbpf_err_ptr(link_fd);
|
|
}
|
|
link->fd = link_fd;
|
|
return link;
|
|
}
|
|
|
|
static int attach_iter(const struct bpf_program *prog, long cookie, struct bpf_link **link)
|
|
{
|
|
*link = bpf_program__attach_iter(prog, NULL);
|
|
return libbpf_get_error(*link);
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach(const struct bpf_program *prog)
|
|
{
|
|
struct bpf_link *link = NULL;
|
|
int err;
|
|
|
|
if (!prog->sec_def || !prog->sec_def->prog_attach_fn)
|
|
return libbpf_err_ptr(-EOPNOTSUPP);
|
|
|
|
err = prog->sec_def->prog_attach_fn(prog, prog->sec_def->cookie, &link);
|
|
if (err)
|
|
return libbpf_err_ptr(err);
|
|
|
|
/* When calling bpf_program__attach() explicitly, auto-attach support
|
|
* is expected to work, so NULL returned link is considered an error.
|
|
* This is different for skeleton's attach, see comment in
|
|
* bpf_object__attach_skeleton().
|
|
*/
|
|
if (!link)
|
|
return libbpf_err_ptr(-EOPNOTSUPP);
|
|
|
|
return link;
|
|
}
|
|
|
|
static int bpf_link__detach_struct_ops(struct bpf_link *link)
|
|
{
|
|
__u32 zero = 0;
|
|
|
|
if (bpf_map_delete_elem(link->fd, &zero))
|
|
return -errno;
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map)
|
|
{
|
|
struct bpf_struct_ops *st_ops;
|
|
struct bpf_link *link;
|
|
__u32 i, zero = 0;
|
|
int err;
|
|
|
|
if (!bpf_map__is_struct_ops(map) || map->fd == -1)
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link)
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
st_ops = map->st_ops;
|
|
for (i = 0; i < btf_vlen(st_ops->type); i++) {
|
|
struct bpf_program *prog = st_ops->progs[i];
|
|
void *kern_data;
|
|
int prog_fd;
|
|
|
|
if (!prog)
|
|
continue;
|
|
|
|
prog_fd = bpf_program__fd(prog);
|
|
kern_data = st_ops->kern_vdata + st_ops->kern_func_off[i];
|
|
*(unsigned long *)kern_data = prog_fd;
|
|
}
|
|
|
|
err = bpf_map_update_elem(map->fd, &zero, st_ops->kern_vdata, 0);
|
|
if (err) {
|
|
err = -errno;
|
|
free(link);
|
|
return libbpf_err_ptr(err);
|
|
}
|
|
|
|
link->detach = bpf_link__detach_struct_ops;
|
|
link->fd = map->fd;
|
|
|
|
return link;
|
|
}
|
|
|
|
static enum bpf_perf_event_ret
|
|
perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
|
|
void **copy_mem, size_t *copy_size,
|
|
bpf_perf_event_print_t fn, void *private_data)
|
|
{
|
|
struct perf_event_mmap_page *header = mmap_mem;
|
|
__u64 data_head = ring_buffer_read_head(header);
|
|
__u64 data_tail = header->data_tail;
|
|
void *base = ((__u8 *)header) + page_size;
|
|
int ret = LIBBPF_PERF_EVENT_CONT;
|
|
struct perf_event_header *ehdr;
|
|
size_t ehdr_size;
|
|
|
|
while (data_head != data_tail) {
|
|
ehdr = base + (data_tail & (mmap_size - 1));
|
|
ehdr_size = ehdr->size;
|
|
|
|
if (((void *)ehdr) + ehdr_size > base + mmap_size) {
|
|
void *copy_start = ehdr;
|
|
size_t len_first = base + mmap_size - copy_start;
|
|
size_t len_secnd = ehdr_size - len_first;
|
|
|
|
if (*copy_size < ehdr_size) {
|
|
free(*copy_mem);
|
|
*copy_mem = malloc(ehdr_size);
|
|
if (!*copy_mem) {
|
|
*copy_size = 0;
|
|
ret = LIBBPF_PERF_EVENT_ERROR;
|
|
break;
|
|
}
|
|
*copy_size = ehdr_size;
|
|
}
|
|
|
|
memcpy(*copy_mem, copy_start, len_first);
|
|
memcpy(*copy_mem + len_first, base, len_secnd);
|
|
ehdr = *copy_mem;
|
|
}
|
|
|
|
ret = fn(ehdr, private_data);
|
|
data_tail += ehdr_size;
|
|
if (ret != LIBBPF_PERF_EVENT_CONT)
|
|
break;
|
|
}
|
|
|
|
ring_buffer_write_tail(header, data_tail);
|
|
return libbpf_err(ret);
|
|
}
|
|
|
|
__attribute__((alias("perf_event_read_simple")))
|
|
enum bpf_perf_event_ret
|
|
bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
|
|
void **copy_mem, size_t *copy_size,
|
|
bpf_perf_event_print_t fn, void *private_data);
|
|
|
|
struct perf_buffer;
|
|
|
|
struct perf_buffer_params {
|
|
struct perf_event_attr *attr;
|
|
/* if event_cb is specified, it takes precendence */
|
|
perf_buffer_event_fn event_cb;
|
|
/* sample_cb and lost_cb are higher-level common-case callbacks */
|
|
perf_buffer_sample_fn sample_cb;
|
|
perf_buffer_lost_fn lost_cb;
|
|
void *ctx;
|
|
int cpu_cnt;
|
|
int *cpus;
|
|
int *map_keys;
|
|
};
|
|
|
|
struct perf_cpu_buf {
|
|
struct perf_buffer *pb;
|
|
void *base; /* mmap()'ed memory */
|
|
void *buf; /* for reconstructing segmented data */
|
|
size_t buf_size;
|
|
int fd;
|
|
int cpu;
|
|
int map_key;
|
|
};
|
|
|
|
struct perf_buffer {
|
|
perf_buffer_event_fn event_cb;
|
|
perf_buffer_sample_fn sample_cb;
|
|
perf_buffer_lost_fn lost_cb;
|
|
void *ctx; /* passed into callbacks */
|
|
|
|
size_t page_size;
|
|
size_t mmap_size;
|
|
struct perf_cpu_buf **cpu_bufs;
|
|
struct epoll_event *events;
|
|
int cpu_cnt; /* number of allocated CPU buffers */
|
|
int epoll_fd; /* perf event FD */
|
|
int map_fd; /* BPF_MAP_TYPE_PERF_EVENT_ARRAY BPF map FD */
|
|
};
|
|
|
|
static void perf_buffer__free_cpu_buf(struct perf_buffer *pb,
|
|
struct perf_cpu_buf *cpu_buf)
|
|
{
|
|
if (!cpu_buf)
|
|
return;
|
|
if (cpu_buf->base &&
|
|
munmap(cpu_buf->base, pb->mmap_size + pb->page_size))
|
|
pr_warn("failed to munmap cpu_buf #%d\n", cpu_buf->cpu);
|
|
if (cpu_buf->fd >= 0) {
|
|
ioctl(cpu_buf->fd, PERF_EVENT_IOC_DISABLE, 0);
|
|
close(cpu_buf->fd);
|
|
}
|
|
free(cpu_buf->buf);
|
|
free(cpu_buf);
|
|
}
|
|
|
|
void perf_buffer__free(struct perf_buffer *pb)
|
|
{
|
|
int i;
|
|
|
|
if (IS_ERR_OR_NULL(pb))
|
|
return;
|
|
if (pb->cpu_bufs) {
|
|
for (i = 0; i < pb->cpu_cnt; i++) {
|
|
struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i];
|
|
|
|
if (!cpu_buf)
|
|
continue;
|
|
|
|
bpf_map_delete_elem(pb->map_fd, &cpu_buf->map_key);
|
|
perf_buffer__free_cpu_buf(pb, cpu_buf);
|
|
}
|
|
free(pb->cpu_bufs);
|
|
}
|
|
if (pb->epoll_fd >= 0)
|
|
close(pb->epoll_fd);
|
|
free(pb->events);
|
|
free(pb);
|
|
}
|
|
|
|
static struct perf_cpu_buf *
|
|
perf_buffer__open_cpu_buf(struct perf_buffer *pb, struct perf_event_attr *attr,
|
|
int cpu, int map_key)
|
|
{
|
|
struct perf_cpu_buf *cpu_buf;
|
|
char msg[STRERR_BUFSIZE];
|
|
int err;
|
|
|
|
cpu_buf = calloc(1, sizeof(*cpu_buf));
|
|
if (!cpu_buf)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
cpu_buf->pb = pb;
|
|
cpu_buf->cpu = cpu;
|
|
cpu_buf->map_key = map_key;
|
|
|
|
cpu_buf->fd = syscall(__NR_perf_event_open, attr, -1 /* pid */, cpu,
|
|
-1, PERF_FLAG_FD_CLOEXEC);
|
|
if (cpu_buf->fd < 0) {
|
|
err = -errno;
|
|
pr_warn("failed to open perf buffer event on cpu #%d: %s\n",
|
|
cpu, libbpf_strerror_r(err, msg, sizeof(msg)));
|
|
goto error;
|
|
}
|
|
|
|
cpu_buf->base = mmap(NULL, pb->mmap_size + pb->page_size,
|
|
PROT_READ | PROT_WRITE, MAP_SHARED,
|
|
cpu_buf->fd, 0);
|
|
if (cpu_buf->base == MAP_FAILED) {
|
|
cpu_buf->base = NULL;
|
|
err = -errno;
|
|
pr_warn("failed to mmap perf buffer on cpu #%d: %s\n",
|
|
cpu, libbpf_strerror_r(err, msg, sizeof(msg)));
|
|
goto error;
|
|
}
|
|
|
|
if (ioctl(cpu_buf->fd, PERF_EVENT_IOC_ENABLE, 0) < 0) {
|
|
err = -errno;
|
|
pr_warn("failed to enable perf buffer event on cpu #%d: %s\n",
|
|
cpu, libbpf_strerror_r(err, msg, sizeof(msg)));
|
|
goto error;
|
|
}
|
|
|
|
return cpu_buf;
|
|
|
|
error:
|
|
perf_buffer__free_cpu_buf(pb, cpu_buf);
|
|
return (struct perf_cpu_buf *)ERR_PTR(err);
|
|
}
|
|
|
|
static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt,
|
|
struct perf_buffer_params *p);
|
|
|
|
DEFAULT_VERSION(perf_buffer__new_v0_6_0, perf_buffer__new, LIBBPF_0.6.0)
|
|
struct perf_buffer *perf_buffer__new_v0_6_0(int map_fd, size_t page_cnt,
|
|
perf_buffer_sample_fn sample_cb,
|
|
perf_buffer_lost_fn lost_cb,
|
|
void *ctx,
|
|
const struct perf_buffer_opts *opts)
|
|
{
|
|
struct perf_buffer_params p = {};
|
|
struct perf_event_attr attr = {};
|
|
|
|
if (!OPTS_VALID(opts, perf_buffer_opts))
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
attr.config = PERF_COUNT_SW_BPF_OUTPUT;
|
|
attr.type = PERF_TYPE_SOFTWARE;
|
|
attr.sample_type = PERF_SAMPLE_RAW;
|
|
attr.sample_period = 1;
|
|
attr.wakeup_events = 1;
|
|
|
|
p.attr = &attr;
|
|
p.sample_cb = sample_cb;
|
|
p.lost_cb = lost_cb;
|
|
p.ctx = ctx;
|
|
|
|
return libbpf_ptr(__perf_buffer__new(map_fd, page_cnt, &p));
|
|
}
|
|
|
|
COMPAT_VERSION(perf_buffer__new_deprecated, perf_buffer__new, LIBBPF_0.0.4)
|
|
struct perf_buffer *perf_buffer__new_deprecated(int map_fd, size_t page_cnt,
|
|
const struct perf_buffer_opts *opts)
|
|
{
|
|
return perf_buffer__new_v0_6_0(map_fd, page_cnt,
|
|
opts ? opts->sample_cb : NULL,
|
|
opts ? opts->lost_cb : NULL,
|
|
opts ? opts->ctx : NULL,
|
|
NULL);
|
|
}
|
|
|
|
DEFAULT_VERSION(perf_buffer__new_raw_v0_6_0, perf_buffer__new_raw, LIBBPF_0.6.0)
|
|
struct perf_buffer *perf_buffer__new_raw_v0_6_0(int map_fd, size_t page_cnt,
|
|
struct perf_event_attr *attr,
|
|
perf_buffer_event_fn event_cb, void *ctx,
|
|
const struct perf_buffer_raw_opts *opts)
|
|
{
|
|
struct perf_buffer_params p = {};
|
|
|
|
if (!attr)
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
if (!OPTS_VALID(opts, perf_buffer_raw_opts))
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
p.attr = attr;
|
|
p.event_cb = event_cb;
|
|
p.ctx = ctx;
|
|
p.cpu_cnt = OPTS_GET(opts, cpu_cnt, 0);
|
|
p.cpus = OPTS_GET(opts, cpus, NULL);
|
|
p.map_keys = OPTS_GET(opts, map_keys, NULL);
|
|
|
|
return libbpf_ptr(__perf_buffer__new(map_fd, page_cnt, &p));
|
|
}
|
|
|
|
COMPAT_VERSION(perf_buffer__new_raw_deprecated, perf_buffer__new_raw, LIBBPF_0.0.4)
|
|
struct perf_buffer *perf_buffer__new_raw_deprecated(int map_fd, size_t page_cnt,
|
|
const struct perf_buffer_raw_opts *opts)
|
|
{
|
|
LIBBPF_OPTS(perf_buffer_raw_opts, inner_opts,
|
|
.cpu_cnt = opts->cpu_cnt,
|
|
.cpus = opts->cpus,
|
|
.map_keys = opts->map_keys,
|
|
);
|
|
|
|
return perf_buffer__new_raw_v0_6_0(map_fd, page_cnt, opts->attr,
|
|
opts->event_cb, opts->ctx, &inner_opts);
|
|
}
|
|
|
|
static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt,
|
|
struct perf_buffer_params *p)
|
|
{
|
|
const char *online_cpus_file = "/sys/devices/system/cpu/online";
|
|
struct bpf_map_info map;
|
|
char msg[STRERR_BUFSIZE];
|
|
struct perf_buffer *pb;
|
|
bool *online = NULL;
|
|
__u32 map_info_len;
|
|
int err, i, j, n;
|
|
|
|
if (page_cnt == 0 || (page_cnt & (page_cnt - 1))) {
|
|
pr_warn("page count should be power of two, but is %zu\n",
|
|
page_cnt);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
/* best-effort sanity checks */
|
|
memset(&map, 0, sizeof(map));
|
|
map_info_len = sizeof(map);
|
|
err = bpf_obj_get_info_by_fd(map_fd, &map, &map_info_len);
|
|
if (err) {
|
|
err = -errno;
|
|
/* if BPF_OBJ_GET_INFO_BY_FD is supported, will return
|
|
* -EBADFD, -EFAULT, or -E2BIG on real error
|
|
*/
|
|
if (err != -EINVAL) {
|
|
pr_warn("failed to get map info for map FD %d: %s\n",
|
|
map_fd, libbpf_strerror_r(err, msg, sizeof(msg)));
|
|
return ERR_PTR(err);
|
|
}
|
|
pr_debug("failed to get map info for FD %d; API not supported? Ignoring...\n",
|
|
map_fd);
|
|
} else {
|
|
if (map.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
|
|
pr_warn("map '%s' should be BPF_MAP_TYPE_PERF_EVENT_ARRAY\n",
|
|
map.name);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
}
|
|
|
|
pb = calloc(1, sizeof(*pb));
|
|
if (!pb)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
pb->event_cb = p->event_cb;
|
|
pb->sample_cb = p->sample_cb;
|
|
pb->lost_cb = p->lost_cb;
|
|
pb->ctx = p->ctx;
|
|
|
|
pb->page_size = getpagesize();
|
|
pb->mmap_size = pb->page_size * page_cnt;
|
|
pb->map_fd = map_fd;
|
|
|
|
pb->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
|
|
if (pb->epoll_fd < 0) {
|
|
err = -errno;
|
|
pr_warn("failed to create epoll instance: %s\n",
|
|
libbpf_strerror_r(err, msg, sizeof(msg)));
|
|
goto error;
|
|
}
|
|
|
|
if (p->cpu_cnt > 0) {
|
|
pb->cpu_cnt = p->cpu_cnt;
|
|
} else {
|
|
pb->cpu_cnt = libbpf_num_possible_cpus();
|
|
if (pb->cpu_cnt < 0) {
|
|
err = pb->cpu_cnt;
|
|
goto error;
|
|
}
|
|
if (map.max_entries && map.max_entries < pb->cpu_cnt)
|
|
pb->cpu_cnt = map.max_entries;
|
|
}
|
|
|
|
pb->events = calloc(pb->cpu_cnt, sizeof(*pb->events));
|
|
if (!pb->events) {
|
|
err = -ENOMEM;
|
|
pr_warn("failed to allocate events: out of memory\n");
|
|
goto error;
|
|
}
|
|
pb->cpu_bufs = calloc(pb->cpu_cnt, sizeof(*pb->cpu_bufs));
|
|
if (!pb->cpu_bufs) {
|
|
err = -ENOMEM;
|
|
pr_warn("failed to allocate buffers: out of memory\n");
|
|
goto error;
|
|
}
|
|
|
|
err = parse_cpu_mask_file(online_cpus_file, &online, &n);
|
|
if (err) {
|
|
pr_warn("failed to get online CPU mask: %d\n", err);
|
|
goto error;
|
|
}
|
|
|
|
for (i = 0, j = 0; i < pb->cpu_cnt; i++) {
|
|
struct perf_cpu_buf *cpu_buf;
|
|
int cpu, map_key;
|
|
|
|
cpu = p->cpu_cnt > 0 ? p->cpus[i] : i;
|
|
map_key = p->cpu_cnt > 0 ? p->map_keys[i] : i;
|
|
|
|
/* in case user didn't explicitly requested particular CPUs to
|
|
* be attached to, skip offline/not present CPUs
|
|
*/
|
|
if (p->cpu_cnt <= 0 && (cpu >= n || !online[cpu]))
|
|
continue;
|
|
|
|
cpu_buf = perf_buffer__open_cpu_buf(pb, p->attr, cpu, map_key);
|
|
if (IS_ERR(cpu_buf)) {
|
|
err = PTR_ERR(cpu_buf);
|
|
goto error;
|
|
}
|
|
|
|
pb->cpu_bufs[j] = cpu_buf;
|
|
|
|
err = bpf_map_update_elem(pb->map_fd, &map_key,
|
|
&cpu_buf->fd, 0);
|
|
if (err) {
|
|
err = -errno;
|
|
pr_warn("failed to set cpu #%d, key %d -> perf FD %d: %s\n",
|
|
cpu, map_key, cpu_buf->fd,
|
|
libbpf_strerror_r(err, msg, sizeof(msg)));
|
|
goto error;
|
|
}
|
|
|
|
pb->events[j].events = EPOLLIN;
|
|
pb->events[j].data.ptr = cpu_buf;
|
|
if (epoll_ctl(pb->epoll_fd, EPOLL_CTL_ADD, cpu_buf->fd,
|
|
&pb->events[j]) < 0) {
|
|
err = -errno;
|
|
pr_warn("failed to epoll_ctl cpu #%d perf FD %d: %s\n",
|
|
cpu, cpu_buf->fd,
|
|
libbpf_strerror_r(err, msg, sizeof(msg)));
|
|
goto error;
|
|
}
|
|
j++;
|
|
}
|
|
pb->cpu_cnt = j;
|
|
free(online);
|
|
|
|
return pb;
|
|
|
|
error:
|
|
free(online);
|
|
if (pb)
|
|
perf_buffer__free(pb);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
struct perf_sample_raw {
|
|
struct perf_event_header header;
|
|
uint32_t size;
|
|
char data[];
|
|
};
|
|
|
|
struct perf_sample_lost {
|
|
struct perf_event_header header;
|
|
uint64_t id;
|
|
uint64_t lost;
|
|
uint64_t sample_id;
|
|
};
|
|
|
|
static enum bpf_perf_event_ret
|
|
perf_buffer__process_record(struct perf_event_header *e, void *ctx)
|
|
{
|
|
struct perf_cpu_buf *cpu_buf = ctx;
|
|
struct perf_buffer *pb = cpu_buf->pb;
|
|
void *data = e;
|
|
|
|
/* user wants full control over parsing perf event */
|
|
if (pb->event_cb)
|
|
return pb->event_cb(pb->ctx, cpu_buf->cpu, e);
|
|
|
|
switch (e->type) {
|
|
case PERF_RECORD_SAMPLE: {
|
|
struct perf_sample_raw *s = data;
|
|
|
|
if (pb->sample_cb)
|
|
pb->sample_cb(pb->ctx, cpu_buf->cpu, s->data, s->size);
|
|
break;
|
|
}
|
|
case PERF_RECORD_LOST: {
|
|
struct perf_sample_lost *s = data;
|
|
|
|
if (pb->lost_cb)
|
|
pb->lost_cb(pb->ctx, cpu_buf->cpu, s->lost);
|
|
break;
|
|
}
|
|
default:
|
|
pr_warn("unknown perf sample type %d\n", e->type);
|
|
return LIBBPF_PERF_EVENT_ERROR;
|
|
}
|
|
return LIBBPF_PERF_EVENT_CONT;
|
|
}
|
|
|
|
static int perf_buffer__process_records(struct perf_buffer *pb,
|
|
struct perf_cpu_buf *cpu_buf)
|
|
{
|
|
enum bpf_perf_event_ret ret;
|
|
|
|
ret = perf_event_read_simple(cpu_buf->base, pb->mmap_size,
|
|
pb->page_size, &cpu_buf->buf,
|
|
&cpu_buf->buf_size,
|
|
perf_buffer__process_record, cpu_buf);
|
|
if (ret != LIBBPF_PERF_EVENT_CONT)
|
|
return ret;
|
|
return 0;
|
|
}
|
|
|
|
int perf_buffer__epoll_fd(const struct perf_buffer *pb)
|
|
{
|
|
return pb->epoll_fd;
|
|
}
|
|
|
|
int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms)
|
|
{
|
|
int i, cnt, err;
|
|
|
|
cnt = epoll_wait(pb->epoll_fd, pb->events, pb->cpu_cnt, timeout_ms);
|
|
if (cnt < 0)
|
|
return -errno;
|
|
|
|
for (i = 0; i < cnt; i++) {
|
|
struct perf_cpu_buf *cpu_buf = pb->events[i].data.ptr;
|
|
|
|
err = perf_buffer__process_records(pb, cpu_buf);
|
|
if (err) {
|
|
pr_warn("error while processing records: %d\n", err);
|
|
return libbpf_err(err);
|
|
}
|
|
}
|
|
return cnt;
|
|
}
|
|
|
|
/* Return number of PERF_EVENT_ARRAY map slots set up by this perf_buffer
|
|
* manager.
|
|
*/
|
|
size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb)
|
|
{
|
|
return pb->cpu_cnt;
|
|
}
|
|
|
|
/*
|
|
* Return perf_event FD of a ring buffer in *buf_idx* slot of
|
|
* PERF_EVENT_ARRAY BPF map. This FD can be polled for new data using
|
|
* select()/poll()/epoll() Linux syscalls.
|
|
*/
|
|
int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx)
|
|
{
|
|
struct perf_cpu_buf *cpu_buf;
|
|
|
|
if (buf_idx >= pb->cpu_cnt)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
cpu_buf = pb->cpu_bufs[buf_idx];
|
|
if (!cpu_buf)
|
|
return libbpf_err(-ENOENT);
|
|
|
|
return cpu_buf->fd;
|
|
}
|
|
|
|
/*
|
|
* Consume data from perf ring buffer corresponding to slot *buf_idx* in
|
|
* PERF_EVENT_ARRAY BPF map without waiting/polling. If there is no data to
|
|
* consume, do nothing and return success.
|
|
* Returns:
|
|
* - 0 on success;
|
|
* - <0 on failure.
|
|
*/
|
|
int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx)
|
|
{
|
|
struct perf_cpu_buf *cpu_buf;
|
|
|
|
if (buf_idx >= pb->cpu_cnt)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
cpu_buf = pb->cpu_bufs[buf_idx];
|
|
if (!cpu_buf)
|
|
return libbpf_err(-ENOENT);
|
|
|
|
return perf_buffer__process_records(pb, cpu_buf);
|
|
}
|
|
|
|
int perf_buffer__consume(struct perf_buffer *pb)
|
|
{
|
|
int i, err;
|
|
|
|
for (i = 0; i < pb->cpu_cnt; i++) {
|
|
struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i];
|
|
|
|
if (!cpu_buf)
|
|
continue;
|
|
|
|
err = perf_buffer__process_records(pb, cpu_buf);
|
|
if (err) {
|
|
pr_warn("perf_buffer: failed to process records in buffer #%d: %d\n", i, err);
|
|
return libbpf_err(err);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
struct bpf_prog_info_array_desc {
|
|
int array_offset; /* e.g. offset of jited_prog_insns */
|
|
int count_offset; /* e.g. offset of jited_prog_len */
|
|
int size_offset; /* > 0: offset of rec size,
|
|
* < 0: fix size of -size_offset
|
|
*/
|
|
};
|
|
|
|
static struct bpf_prog_info_array_desc bpf_prog_info_array_desc[] = {
|
|
[BPF_PROG_INFO_JITED_INSNS] = {
|
|
offsetof(struct bpf_prog_info, jited_prog_insns),
|
|
offsetof(struct bpf_prog_info, jited_prog_len),
|
|
-1,
|
|
},
|
|
[BPF_PROG_INFO_XLATED_INSNS] = {
|
|
offsetof(struct bpf_prog_info, xlated_prog_insns),
|
|
offsetof(struct bpf_prog_info, xlated_prog_len),
|
|
-1,
|
|
},
|
|
[BPF_PROG_INFO_MAP_IDS] = {
|
|
offsetof(struct bpf_prog_info, map_ids),
|
|
offsetof(struct bpf_prog_info, nr_map_ids),
|
|
-(int)sizeof(__u32),
|
|
},
|
|
[BPF_PROG_INFO_JITED_KSYMS] = {
|
|
offsetof(struct bpf_prog_info, jited_ksyms),
|
|
offsetof(struct bpf_prog_info, nr_jited_ksyms),
|
|
-(int)sizeof(__u64),
|
|
},
|
|
[BPF_PROG_INFO_JITED_FUNC_LENS] = {
|
|
offsetof(struct bpf_prog_info, jited_func_lens),
|
|
offsetof(struct bpf_prog_info, nr_jited_func_lens),
|
|
-(int)sizeof(__u32),
|
|
},
|
|
[BPF_PROG_INFO_FUNC_INFO] = {
|
|
offsetof(struct bpf_prog_info, func_info),
|
|
offsetof(struct bpf_prog_info, nr_func_info),
|
|
offsetof(struct bpf_prog_info, func_info_rec_size),
|
|
},
|
|
[BPF_PROG_INFO_LINE_INFO] = {
|
|
offsetof(struct bpf_prog_info, line_info),
|
|
offsetof(struct bpf_prog_info, nr_line_info),
|
|
offsetof(struct bpf_prog_info, line_info_rec_size),
|
|
},
|
|
[BPF_PROG_INFO_JITED_LINE_INFO] = {
|
|
offsetof(struct bpf_prog_info, jited_line_info),
|
|
offsetof(struct bpf_prog_info, nr_jited_line_info),
|
|
offsetof(struct bpf_prog_info, jited_line_info_rec_size),
|
|
},
|
|
[BPF_PROG_INFO_PROG_TAGS] = {
|
|
offsetof(struct bpf_prog_info, prog_tags),
|
|
offsetof(struct bpf_prog_info, nr_prog_tags),
|
|
-(int)sizeof(__u8) * BPF_TAG_SIZE,
|
|
},
|
|
|
|
};
|
|
|
|
static __u32 bpf_prog_info_read_offset_u32(struct bpf_prog_info *info,
|
|
int offset)
|
|
{
|
|
__u32 *array = (__u32 *)info;
|
|
|
|
if (offset >= 0)
|
|
return array[offset / sizeof(__u32)];
|
|
return -(int)offset;
|
|
}
|
|
|
|
static __u64 bpf_prog_info_read_offset_u64(struct bpf_prog_info *info,
|
|
int offset)
|
|
{
|
|
__u64 *array = (__u64 *)info;
|
|
|
|
if (offset >= 0)
|
|
return array[offset / sizeof(__u64)];
|
|
return -(int)offset;
|
|
}
|
|
|
|
static void bpf_prog_info_set_offset_u32(struct bpf_prog_info *info, int offset,
|
|
__u32 val)
|
|
{
|
|
__u32 *array = (__u32 *)info;
|
|
|
|
if (offset >= 0)
|
|
array[offset / sizeof(__u32)] = val;
|
|
}
|
|
|
|
static void bpf_prog_info_set_offset_u64(struct bpf_prog_info *info, int offset,
|
|
__u64 val)
|
|
{
|
|
__u64 *array = (__u64 *)info;
|
|
|
|
if (offset >= 0)
|
|
array[offset / sizeof(__u64)] = val;
|
|
}
|
|
|
|
struct bpf_prog_info_linear *
|
|
bpf_program__get_prog_info_linear(int fd, __u64 arrays)
|
|
{
|
|
struct bpf_prog_info_linear *info_linear;
|
|
struct bpf_prog_info info = {};
|
|
__u32 info_len = sizeof(info);
|
|
__u32 data_len = 0;
|
|
int i, err;
|
|
void *ptr;
|
|
|
|
if (arrays >> BPF_PROG_INFO_LAST_ARRAY)
|
|
return libbpf_err_ptr(-EINVAL);
|
|
|
|
/* step 1: get array dimensions */
|
|
err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
|
|
if (err) {
|
|
pr_debug("can't get prog info: %s", strerror(errno));
|
|
return libbpf_err_ptr(-EFAULT);
|
|
}
|
|
|
|
/* step 2: calculate total size of all arrays */
|
|
for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
|
|
bool include_array = (arrays & (1UL << i)) > 0;
|
|
struct bpf_prog_info_array_desc *desc;
|
|
__u32 count, size;
|
|
|
|
desc = bpf_prog_info_array_desc + i;
|
|
|
|
/* kernel is too old to support this field */
|
|
if (info_len < desc->array_offset + sizeof(__u32) ||
|
|
info_len < desc->count_offset + sizeof(__u32) ||
|
|
(desc->size_offset > 0 && info_len < desc->size_offset))
|
|
include_array = false;
|
|
|
|
if (!include_array) {
|
|
arrays &= ~(1UL << i); /* clear the bit */
|
|
continue;
|
|
}
|
|
|
|
count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
|
|
size = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
|
|
|
|
data_len += count * size;
|
|
}
|
|
|
|
/* step 3: allocate continuous memory */
|
|
data_len = roundup(data_len, sizeof(__u64));
|
|
info_linear = malloc(sizeof(struct bpf_prog_info_linear) + data_len);
|
|
if (!info_linear)
|
|
return libbpf_err_ptr(-ENOMEM);
|
|
|
|
/* step 4: fill data to info_linear->info */
|
|
info_linear->arrays = arrays;
|
|
memset(&info_linear->info, 0, sizeof(info));
|
|
ptr = info_linear->data;
|
|
|
|
for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
|
|
struct bpf_prog_info_array_desc *desc;
|
|
__u32 count, size;
|
|
|
|
if ((arrays & (1UL << i)) == 0)
|
|
continue;
|
|
|
|
desc = bpf_prog_info_array_desc + i;
|
|
count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
|
|
size = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
|
|
bpf_prog_info_set_offset_u32(&info_linear->info,
|
|
desc->count_offset, count);
|
|
bpf_prog_info_set_offset_u32(&info_linear->info,
|
|
desc->size_offset, size);
|
|
bpf_prog_info_set_offset_u64(&info_linear->info,
|
|
desc->array_offset,
|
|
ptr_to_u64(ptr));
|
|
ptr += count * size;
|
|
}
|
|
|
|
/* step 5: call syscall again to get required arrays */
|
|
err = bpf_obj_get_info_by_fd(fd, &info_linear->info, &info_len);
|
|
if (err) {
|
|
pr_debug("can't get prog info: %s", strerror(errno));
|
|
free(info_linear);
|
|
return libbpf_err_ptr(-EFAULT);
|
|
}
|
|
|
|
/* step 6: verify the data */
|
|
for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
|
|
struct bpf_prog_info_array_desc *desc;
|
|
__u32 v1, v2;
|
|
|
|
if ((arrays & (1UL << i)) == 0)
|
|
continue;
|
|
|
|
desc = bpf_prog_info_array_desc + i;
|
|
v1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
|
|
v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
|
|
desc->count_offset);
|
|
if (v1 != v2)
|
|
pr_warn("%s: mismatch in element count\n", __func__);
|
|
|
|
v1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
|
|
v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
|
|
desc->size_offset);
|
|
if (v1 != v2)
|
|
pr_warn("%s: mismatch in rec size\n", __func__);
|
|
}
|
|
|
|
/* step 7: update info_len and data_len */
|
|
info_linear->info_len = sizeof(struct bpf_prog_info);
|
|
info_linear->data_len = data_len;
|
|
|
|
return info_linear;
|
|
}
|
|
|
|
void bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear)
|
|
{
|
|
int i;
|
|
|
|
for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
|
|
struct bpf_prog_info_array_desc *desc;
|
|
__u64 addr, offs;
|
|
|
|
if ((info_linear->arrays & (1UL << i)) == 0)
|
|
continue;
|
|
|
|
desc = bpf_prog_info_array_desc + i;
|
|
addr = bpf_prog_info_read_offset_u64(&info_linear->info,
|
|
desc->array_offset);
|
|
offs = addr - ptr_to_u64(info_linear->data);
|
|
bpf_prog_info_set_offset_u64(&info_linear->info,
|
|
desc->array_offset, offs);
|
|
}
|
|
}
|
|
|
|
void bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear)
|
|
{
|
|
int i;
|
|
|
|
for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
|
|
struct bpf_prog_info_array_desc *desc;
|
|
__u64 addr, offs;
|
|
|
|
if ((info_linear->arrays & (1UL << i)) == 0)
|
|
continue;
|
|
|
|
desc = bpf_prog_info_array_desc + i;
|
|
offs = bpf_prog_info_read_offset_u64(&info_linear->info,
|
|
desc->array_offset);
|
|
addr = offs + ptr_to_u64(info_linear->data);
|
|
bpf_prog_info_set_offset_u64(&info_linear->info,
|
|
desc->array_offset, addr);
|
|
}
|
|
}
|
|
|
|
int bpf_program__set_attach_target(struct bpf_program *prog,
|
|
int attach_prog_fd,
|
|
const char *attach_func_name)
|
|
{
|
|
int btf_obj_fd = 0, btf_id = 0, err;
|
|
|
|
if (!prog || attach_prog_fd < 0)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
if (prog->obj->loaded)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
if (attach_prog_fd && !attach_func_name) {
|
|
/* remember attach_prog_fd and let bpf_program__load() find
|
|
* BTF ID during the program load
|
|
*/
|
|
prog->attach_prog_fd = attach_prog_fd;
|
|
return 0;
|
|
}
|
|
|
|
if (attach_prog_fd) {
|
|
btf_id = libbpf_find_prog_btf_id(attach_func_name,
|
|
attach_prog_fd);
|
|
if (btf_id < 0)
|
|
return libbpf_err(btf_id);
|
|
} else {
|
|
if (!attach_func_name)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
/* load btf_vmlinux, if not yet */
|
|
err = bpf_object__load_vmlinux_btf(prog->obj, true);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
err = find_kernel_btf_id(prog->obj, attach_func_name,
|
|
prog->expected_attach_type,
|
|
&btf_obj_fd, &btf_id);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
prog->attach_btf_id = btf_id;
|
|
prog->attach_btf_obj_fd = btf_obj_fd;
|
|
prog->attach_prog_fd = attach_prog_fd;
|
|
return 0;
|
|
}
|
|
|
|
int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz)
|
|
{
|
|
int err = 0, n, len, start, end = -1;
|
|
bool *tmp;
|
|
|
|
*mask = NULL;
|
|
*mask_sz = 0;
|
|
|
|
/* Each sub string separated by ',' has format \d+-\d+ or \d+ */
|
|
while (*s) {
|
|
if (*s == ',' || *s == '\n') {
|
|
s++;
|
|
continue;
|
|
}
|
|
n = sscanf(s, "%d%n-%d%n", &start, &len, &end, &len);
|
|
if (n <= 0 || n > 2) {
|
|
pr_warn("Failed to get CPU range %s: %d\n", s, n);
|
|
err = -EINVAL;
|
|
goto cleanup;
|
|
} else if (n == 1) {
|
|
end = start;
|
|
}
|
|
if (start < 0 || start > end) {
|
|
pr_warn("Invalid CPU range [%d,%d] in %s\n",
|
|
start, end, s);
|
|
err = -EINVAL;
|
|
goto cleanup;
|
|
}
|
|
tmp = realloc(*mask, end + 1);
|
|
if (!tmp) {
|
|
err = -ENOMEM;
|
|
goto cleanup;
|
|
}
|
|
*mask = tmp;
|
|
memset(tmp + *mask_sz, 0, start - *mask_sz);
|
|
memset(tmp + start, 1, end - start + 1);
|
|
*mask_sz = end + 1;
|
|
s += len;
|
|
}
|
|
if (!*mask_sz) {
|
|
pr_warn("Empty CPU range\n");
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
cleanup:
|
|
free(*mask);
|
|
*mask = NULL;
|
|
return err;
|
|
}
|
|
|
|
int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz)
|
|
{
|
|
int fd, err = 0, len;
|
|
char buf[128];
|
|
|
|
fd = open(fcpu, O_RDONLY | O_CLOEXEC);
|
|
if (fd < 0) {
|
|
err = -errno;
|
|
pr_warn("Failed to open cpu mask file %s: %d\n", fcpu, err);
|
|
return err;
|
|
}
|
|
len = read(fd, buf, sizeof(buf));
|
|
close(fd);
|
|
if (len <= 0) {
|
|
err = len ? -errno : -EINVAL;
|
|
pr_warn("Failed to read cpu mask from %s: %d\n", fcpu, err);
|
|
return err;
|
|
}
|
|
if (len >= sizeof(buf)) {
|
|
pr_warn("CPU mask is too big in file %s\n", fcpu);
|
|
return -E2BIG;
|
|
}
|
|
buf[len] = '\0';
|
|
|
|
return parse_cpu_mask_str(buf, mask, mask_sz);
|
|
}
|
|
|
|
int libbpf_num_possible_cpus(void)
|
|
{
|
|
static const char *fcpu = "/sys/devices/system/cpu/possible";
|
|
static int cpus;
|
|
int err, n, i, tmp_cpus;
|
|
bool *mask;
|
|
|
|
tmp_cpus = READ_ONCE(cpus);
|
|
if (tmp_cpus > 0)
|
|
return tmp_cpus;
|
|
|
|
err = parse_cpu_mask_file(fcpu, &mask, &n);
|
|
if (err)
|
|
return libbpf_err(err);
|
|
|
|
tmp_cpus = 0;
|
|
for (i = 0; i < n; i++) {
|
|
if (mask[i])
|
|
tmp_cpus++;
|
|
}
|
|
free(mask);
|
|
|
|
WRITE_ONCE(cpus, tmp_cpus);
|
|
return tmp_cpus;
|
|
}
|
|
|
|
static int populate_skeleton_maps(const struct bpf_object *obj,
|
|
struct bpf_map_skeleton *maps,
|
|
size_t map_cnt)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < map_cnt; i++) {
|
|
struct bpf_map **map = maps[i].map;
|
|
const char *name = maps[i].name;
|
|
void **mmaped = maps[i].mmaped;
|
|
|
|
*map = bpf_object__find_map_by_name(obj, name);
|
|
if (!*map) {
|
|
pr_warn("failed to find skeleton map '%s'\n", name);
|
|
return -ESRCH;
|
|
}
|
|
|
|
/* externs shouldn't be pre-setup from user code */
|
|
if (mmaped && (*map)->libbpf_type != LIBBPF_MAP_KCONFIG)
|
|
*mmaped = (*map)->mmaped;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int populate_skeleton_progs(const struct bpf_object *obj,
|
|
struct bpf_prog_skeleton *progs,
|
|
size_t prog_cnt)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < prog_cnt; i++) {
|
|
struct bpf_program **prog = progs[i].prog;
|
|
const char *name = progs[i].name;
|
|
|
|
*prog = bpf_object__find_program_by_name(obj, name);
|
|
if (!*prog) {
|
|
pr_warn("failed to find skeleton program '%s'\n", name);
|
|
return -ESRCH;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int bpf_object__open_skeleton(struct bpf_object_skeleton *s,
|
|
const struct bpf_object_open_opts *opts)
|
|
{
|
|
DECLARE_LIBBPF_OPTS(bpf_object_open_opts, skel_opts,
|
|
.object_name = s->name,
|
|
);
|
|
struct bpf_object *obj;
|
|
int err;
|
|
|
|
/* Attempt to preserve opts->object_name, unless overriden by user
|
|
* explicitly. Overwriting object name for skeletons is discouraged,
|
|
* as it breaks global data maps, because they contain object name
|
|
* prefix as their own map name prefix. When skeleton is generated,
|
|
* bpftool is making an assumption that this name will stay the same.
|
|
*/
|
|
if (opts) {
|
|
memcpy(&skel_opts, opts, sizeof(*opts));
|
|
if (!opts->object_name)
|
|
skel_opts.object_name = s->name;
|
|
}
|
|
|
|
obj = bpf_object__open_mem(s->data, s->data_sz, &skel_opts);
|
|
err = libbpf_get_error(obj);
|
|
if (err) {
|
|
pr_warn("failed to initialize skeleton BPF object '%s': %d\n",
|
|
s->name, err);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
*s->obj = obj;
|
|
err = populate_skeleton_maps(obj, s->maps, s->map_cnt);
|
|
if (err) {
|
|
pr_warn("failed to populate skeleton maps for '%s': %d\n", s->name, err);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
err = populate_skeleton_progs(obj, s->progs, s->prog_cnt);
|
|
if (err) {
|
|
pr_warn("failed to populate skeleton progs for '%s': %d\n", s->name, err);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bpf_object__open_subskeleton(struct bpf_object_subskeleton *s)
|
|
{
|
|
int err, len, var_idx, i;
|
|
const char *var_name;
|
|
const struct bpf_map *map;
|
|
struct btf *btf;
|
|
__u32 map_type_id;
|
|
const struct btf_type *map_type, *var_type;
|
|
const struct bpf_var_skeleton *var_skel;
|
|
struct btf_var_secinfo *var;
|
|
|
|
if (!s->obj)
|
|
return libbpf_err(-EINVAL);
|
|
|
|
btf = bpf_object__btf(s->obj);
|
|
if (!btf) {
|
|
pr_warn("subskeletons require BTF at runtime (object %s)\n",
|
|
bpf_object__name(s->obj));
|
|
return libbpf_err(-errno);
|
|
}
|
|
|
|
err = populate_skeleton_maps(s->obj, s->maps, s->map_cnt);
|
|
if (err) {
|
|
pr_warn("failed to populate subskeleton maps: %d\n", err);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
err = populate_skeleton_progs(s->obj, s->progs, s->prog_cnt);
|
|
if (err) {
|
|
pr_warn("failed to populate subskeleton maps: %d\n", err);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
for (var_idx = 0; var_idx < s->var_cnt; var_idx++) {
|
|
var_skel = &s->vars[var_idx];
|
|
map = *var_skel->map;
|
|
map_type_id = bpf_map__btf_value_type_id(map);
|
|
map_type = btf__type_by_id(btf, map_type_id);
|
|
|
|
if (!btf_is_datasec(map_type)) {
|
|
pr_warn("type for map '%1$s' is not a datasec: %2$s",
|
|
bpf_map__name(map),
|
|
__btf_kind_str(btf_kind(map_type)));
|
|
return libbpf_err(-EINVAL);
|
|
}
|
|
|
|
len = btf_vlen(map_type);
|
|
var = btf_var_secinfos(map_type);
|
|
for (i = 0; i < len; i++, var++) {
|
|
var_type = btf__type_by_id(btf, var->type);
|
|
var_name = btf__name_by_offset(btf, var_type->name_off);
|
|
if (strcmp(var_name, var_skel->name) == 0) {
|
|
*var_skel->addr = map->mmaped + var->offset;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s)
|
|
{
|
|
if (!s)
|
|
return;
|
|
free(s->maps);
|
|
free(s->progs);
|
|
free(s->vars);
|
|
free(s);
|
|
}
|
|
|
|
int bpf_object__load_skeleton(struct bpf_object_skeleton *s)
|
|
{
|
|
int i, err;
|
|
|
|
err = bpf_object__load(*s->obj);
|
|
if (err) {
|
|
pr_warn("failed to load BPF skeleton '%s': %d\n", s->name, err);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
for (i = 0; i < s->map_cnt; i++) {
|
|
struct bpf_map *map = *s->maps[i].map;
|
|
size_t mmap_sz = bpf_map_mmap_sz(map);
|
|
int prot, map_fd = bpf_map__fd(map);
|
|
void **mmaped = s->maps[i].mmaped;
|
|
|
|
if (!mmaped)
|
|
continue;
|
|
|
|
if (!(map->def.map_flags & BPF_F_MMAPABLE)) {
|
|
*mmaped = NULL;
|
|
continue;
|
|
}
|
|
|
|
if (map->def.map_flags & BPF_F_RDONLY_PROG)
|
|
prot = PROT_READ;
|
|
else
|
|
prot = PROT_READ | PROT_WRITE;
|
|
|
|
/* Remap anonymous mmap()-ed "map initialization image" as
|
|
* a BPF map-backed mmap()-ed memory, but preserving the same
|
|
* memory address. This will cause kernel to change process'
|
|
* page table to point to a different piece of kernel memory,
|
|
* but from userspace point of view memory address (and its
|
|
* contents, being identical at this point) will stay the
|
|
* same. This mapping will be released by bpf_object__close()
|
|
* as per normal clean up procedure, so we don't need to worry
|
|
* about it from skeleton's clean up perspective.
|
|
*/
|
|
*mmaped = mmap(map->mmaped, mmap_sz, prot,
|
|
MAP_SHARED | MAP_FIXED, map_fd, 0);
|
|
if (*mmaped == MAP_FAILED) {
|
|
err = -errno;
|
|
*mmaped = NULL;
|
|
pr_warn("failed to re-mmap() map '%s': %d\n",
|
|
bpf_map__name(map), err);
|
|
return libbpf_err(err);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
|
|
{
|
|
int i, err;
|
|
|
|
for (i = 0; i < s->prog_cnt; i++) {
|
|
struct bpf_program *prog = *s->progs[i].prog;
|
|
struct bpf_link **link = s->progs[i].link;
|
|
|
|
if (!prog->autoload)
|
|
continue;
|
|
|
|
/* auto-attaching not supported for this program */
|
|
if (!prog->sec_def || !prog->sec_def->prog_attach_fn)
|
|
continue;
|
|
|
|
/* if user already set the link manually, don't attempt auto-attach */
|
|
if (*link)
|
|
continue;
|
|
|
|
err = prog->sec_def->prog_attach_fn(prog, prog->sec_def->cookie, link);
|
|
if (err) {
|
|
pr_warn("prog '%s': failed to auto-attach: %d\n",
|
|
bpf_program__name(prog), err);
|
|
return libbpf_err(err);
|
|
}
|
|
|
|
/* It's possible that for some SEC() definitions auto-attach
|
|
* is supported in some cases (e.g., if definition completely
|
|
* specifies target information), but is not in other cases.
|
|
* SEC("uprobe") is one such case. If user specified target
|
|
* binary and function name, such BPF program can be
|
|
* auto-attached. But if not, it shouldn't trigger skeleton's
|
|
* attach to fail. It should just be skipped.
|
|
* attach_fn signals such case with returning 0 (no error) and
|
|
* setting link to NULL.
|
|
*/
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void bpf_object__detach_skeleton(struct bpf_object_skeleton *s)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < s->prog_cnt; i++) {
|
|
struct bpf_link **link = s->progs[i].link;
|
|
|
|
bpf_link__destroy(*link);
|
|
*link = NULL;
|
|
}
|
|
}
|
|
|
|
void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s)
|
|
{
|
|
if (!s)
|
|
return;
|
|
|
|
if (s->progs)
|
|
bpf_object__detach_skeleton(s);
|
|
if (s->obj)
|
|
bpf_object__close(*s->obj);
|
|
free(s->maps);
|
|
free(s->progs);
|
|
free(s);
|
|
}
|