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![Andrii Nakryiko](/assets/img/avatar_default.png)
Remove invalid assumption in libbpf that .bss map doesn't have to be updated
in kernel. With addition of skeleton and memory-mapped initialization image,
.bss doesn't have to be all zeroes when BPF map is created, because user-code
might have initialized those variables from user-space.
Fixes: eba9c5f498
("libbpf: Refactor global data map initialization")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200612194504.557844-1-andriin@fb.com
9028 lines
224 KiB
C
9028 lines
224 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 <tools/libc_compat.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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/* make sure libbpf doesn't use kernel-only integer typedefs */
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#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64
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#ifndef EM_BPF
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#define EM_BPF 247
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#endif
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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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/* 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 struct bpf_program *bpf_object__find_prog_by_idx(struct bpf_object *obj,
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int idx);
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static const struct btf_type *
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skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id);
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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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#ifdef HAVE_LIBELF_MMAP_SUPPORT
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# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP
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#else
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# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
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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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struct bpf_capabilities {
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/* v4.14: kernel support for program & map names. */
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__u32 name:1;
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/* v5.2: kernel support for global data sections. */
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__u32 global_data:1;
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/* BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO support */
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__u32 btf_func:1;
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/* BTF_KIND_VAR and BTF_KIND_DATASEC support */
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__u32 btf_datasec:1;
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/* BPF_F_MMAPABLE is supported for arrays */
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__u32 array_mmap:1;
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/* BTF_FUNC_GLOBAL is supported */
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__u32 btf_func_global:1;
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/* kernel support for expected_attach_type in BPF_PROG_LOAD */
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__u32 exp_attach_type:1;
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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,
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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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int map_idx;
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int sym_off;
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};
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struct bpf_sec_def;
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typedef struct bpf_link *(*attach_fn_t)(const struct bpf_sec_def *sec,
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struct bpf_program *prog);
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struct bpf_sec_def {
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const char *sec;
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size_t len;
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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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bool is_exp_attach_type_optional;
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bool is_attachable;
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bool is_attach_btf;
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attach_fn_t 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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/* Index in elf obj file, for relocation use. */
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int idx;
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char *name;
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int prog_ifindex;
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char *section_name;
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const struct bpf_sec_def *sec_def;
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/* section_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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struct bpf_insn *insns;
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size_t insns_cnt, main_prog_cnt;
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enum bpf_prog_type type;
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struct reloc_desc *reloc_desc;
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int nr_reloc;
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int 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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enum bpf_attach_type expected_attach_type;
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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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struct bpf_capabilities *caps;
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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 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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static const char * const libbpf_type_to_btf_name[] = {
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[LIBBPF_MAP_DATA] = DATA_SEC,
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[LIBBPF_MAP_BSS] = BSS_SEC,
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[LIBBPF_MAP_RODATA] = RODATA_SEC,
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[LIBBPF_MAP_KCONFIG] = KCONFIG_SEC,
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};
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struct bpf_map {
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char *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 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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};
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enum extern_type {
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EXT_UNKNOWN,
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EXT_CHAR,
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EXT_BOOL,
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EXT_INT,
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EXT_TRISTATE,
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EXT_CHAR_ARR,
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};
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struct extern_desc {
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const char *name;
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int sym_idx;
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int btf_id;
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enum extern_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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bool is_weak;
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bool is_set;
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};
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static LIST_HEAD(bpf_objects_list);
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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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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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bool loaded;
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bool has_pseudo_calls;
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/*
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* Information when doing elf related work. Only valid if fd
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* is valid.
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*/
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struct {
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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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GElf_Ehdr ehdr;
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Elf_Data *symbols;
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Elf_Data *data;
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Elf_Data *rodata;
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Elf_Data *bss;
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Elf_Data *st_ops_data;
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size_t strtabidx;
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struct {
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GElf_Shdr shdr;
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Elf_Data *data;
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} *reloc_sects;
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int nr_reloc_sects;
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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 data_shndx;
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int rodata_shndx;
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int bss_shndx;
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int st_ops_shndx;
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} efile;
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/*
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* All loaded bpf_object is 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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/* 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;
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struct btf_ext *btf_ext;
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void *priv;
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bpf_object_clear_priv_t clear_priv;
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struct bpf_capabilities caps;
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char path[];
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};
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#define obj_elf_valid(o) ((o)->efile.elf)
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|
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void bpf_program__unload(struct bpf_program *prog)
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{
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int i;
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if (!prog)
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return;
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|
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/*
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* If the object is opened but the program was never loaded,
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* it is possible that prog->instances.nr == -1.
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*/
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if (prog->instances.nr > 0) {
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for (i = 0; i < prog->instances.nr; i++)
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zclose(prog->instances.fds[i]);
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} else if (prog->instances.nr != -1) {
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pr_warn("Internal error: instances.nr is %d\n",
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prog->instances.nr);
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}
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|
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prog->instances.nr = -1;
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zfree(&prog->instances.fds);
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|
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zfree(&prog->func_info);
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zfree(&prog->line_info);
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}
|
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|
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static void bpf_program__exit(struct bpf_program *prog)
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{
|
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if (!prog)
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return;
|
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|
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if (prog->clear_priv)
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prog->clear_priv(prog, prog->priv);
|
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|
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prog->priv = NULL;
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prog->clear_priv = NULL;
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|
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bpf_program__unload(prog);
|
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zfree(&prog->name);
|
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zfree(&prog->section_name);
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zfree(&prog->pin_name);
|
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zfree(&prog->insns);
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zfree(&prog->reloc_desc);
|
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|
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prog->nr_reloc = 0;
|
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prog->insns_cnt = 0;
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prog->idx = -1;
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}
|
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|
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static char *__bpf_program__pin_name(struct bpf_program *prog)
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{
|
|
char *name, *p;
|
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|
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name = p = strdup(prog->section_name);
|
|
while ((p = strchr(p, '/')))
|
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*p = '_';
|
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|
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return name;
|
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}
|
|
|
|
static int
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bpf_program__init(void *data, size_t size, char *section_name, int idx,
|
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struct bpf_program *prog)
|
|
{
|
|
const size_t bpf_insn_sz = sizeof(struct bpf_insn);
|
|
|
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if (size == 0 || size % bpf_insn_sz) {
|
|
pr_warn("corrupted section '%s', size: %zu\n",
|
|
section_name, size);
|
|
return -EINVAL;
|
|
}
|
|
|
|
memset(prog, 0, sizeof(*prog));
|
|
|
|
prog->section_name = strdup(section_name);
|
|
if (!prog->section_name) {
|
|
pr_warn("failed to alloc name for prog under section(%d) %s\n",
|
|
idx, section_name);
|
|
goto errout;
|
|
}
|
|
|
|
prog->pin_name = __bpf_program__pin_name(prog);
|
|
if (!prog->pin_name) {
|
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pr_warn("failed to alloc pin name for prog under section(%d) %s\n",
|
|
idx, section_name);
|
|
goto errout;
|
|
}
|
|
|
|
prog->insns = malloc(size);
|
|
if (!prog->insns) {
|
|
pr_warn("failed to alloc insns for prog under section %s\n",
|
|
section_name);
|
|
goto errout;
|
|
}
|
|
prog->insns_cnt = size / bpf_insn_sz;
|
|
memcpy(prog->insns, data, size);
|
|
prog->idx = idx;
|
|
prog->instances.fds = NULL;
|
|
prog->instances.nr = -1;
|
|
prog->type = BPF_PROG_TYPE_UNSPEC;
|
|
|
|
return 0;
|
|
errout:
|
|
bpf_program__exit(prog);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int
|
|
bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
|
|
char *section_name, int idx)
|
|
{
|
|
struct bpf_program prog, *progs;
|
|
int nr_progs, err;
|
|
|
|
err = bpf_program__init(data, size, section_name, idx, &prog);
|
|
if (err)
|
|
return err;
|
|
|
|
prog.caps = &obj->caps;
|
|
progs = obj->programs;
|
|
nr_progs = obj->nr_programs;
|
|
|
|
progs = reallocarray(progs, nr_progs + 1, sizeof(progs[0]));
|
|
if (!progs) {
|
|
/*
|
|
* In this case the original obj->programs
|
|
* is still valid, so don't need special treat for
|
|
* bpf_close_object().
|
|
*/
|
|
pr_warn("failed to alloc a new program under section '%s'\n",
|
|
section_name);
|
|
bpf_program__exit(&prog);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
pr_debug("found program %s\n", prog.section_name);
|
|
obj->programs = progs;
|
|
obj->nr_programs = nr_progs + 1;
|
|
prog.obj = obj;
|
|
progs[nr_progs] = prog;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_object__init_prog_names(struct bpf_object *obj)
|
|
{
|
|
Elf_Data *symbols = obj->efile.symbols;
|
|
struct bpf_program *prog;
|
|
size_t pi, si;
|
|
|
|
for (pi = 0; pi < obj->nr_programs; pi++) {
|
|
const char *name = NULL;
|
|
|
|
prog = &obj->programs[pi];
|
|
|
|
for (si = 0; si < symbols->d_size / sizeof(GElf_Sym) && !name;
|
|
si++) {
|
|
GElf_Sym sym;
|
|
|
|
if (!gelf_getsym(symbols, si, &sym))
|
|
continue;
|
|
if (sym.st_shndx != prog->idx)
|
|
continue;
|
|
if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL)
|
|
continue;
|
|
|
|
name = elf_strptr(obj->efile.elf,
|
|
obj->efile.strtabidx,
|
|
sym.st_name);
|
|
if (!name) {
|
|
pr_warn("failed to get sym name string for prog %s\n",
|
|
prog->section_name);
|
|
return -LIBBPF_ERRNO__LIBELF;
|
|
}
|
|
}
|
|
|
|
if (!name && prog->idx == obj->efile.text_shndx)
|
|
name = ".text";
|
|
|
|
if (!name) {
|
|
pr_warn("failed to find sym for prog %s\n",
|
|
prog->section_name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
prog->name = strdup(name);
|
|
if (!prog->name) {
|
|
pr_warn("failed to allocate memory for prog sym %s\n",
|
|
name);
|
|
return -ENOMEM;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static __u32 get_kernel_version(void)
|
|
{
|
|
__u32 major, minor, patch;
|
|
struct utsname info;
|
|
|
|
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;
|
|
|
|
mtype = skip_mods_and_typedefs(btf, mtype->type, &mtype_id);
|
|
kern_mtype = skip_mods_and_typedefs(kern_btf,
|
|
kern_mtype->type,
|
|
&kern_mtype_id);
|
|
if (!btf_is_func_proto(mtype) ||
|
|
!btf_is_func_proto(kern_mtype)) {
|
|
pr_warn("struct_ops init_kern %s: non func ptr %s is not supported\n",
|
|
map->name, mname);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
prog = st_ops->progs[i];
|
|
if (!prog) {
|
|
pr_debug("struct_ops init_kern %s: func ptr %s is not set\n",
|
|
map->name, mname);
|
|
continue;
|
|
}
|
|
|
|
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)
|
|
{
|
|
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) {
|
|
strncpy(obj->name, obj_name, sizeof(obj->name) - 1);
|
|
obj->name[sizeof(obj->name) - 1] = 0;
|
|
} else {
|
|
/* Using basename() GNU version which doesn't modify arg. */
|
|
strncpy(obj->name, basename((void *)path),
|
|
sizeof(obj->name) - 1);
|
|
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.data_shndx = -1;
|
|
obj->efile.rodata_shndx = -1;
|
|
obj->efile.bss_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);
|
|
list_add(&obj->list, &bpf_objects_list);
|
|
return obj;
|
|
}
|
|
|
|
static void bpf_object__elf_finish(struct bpf_object *obj)
|
|
{
|
|
if (!obj_elf_valid(obj))
|
|
return;
|
|
|
|
if (obj->efile.elf) {
|
|
elf_end(obj->efile.elf);
|
|
obj->efile.elf = NULL;
|
|
}
|
|
obj->efile.symbols = NULL;
|
|
obj->efile.data = NULL;
|
|
obj->efile.rodata = NULL;
|
|
obj->efile.bss = NULL;
|
|
obj->efile.st_ops_data = NULL;
|
|
|
|
zfree(&obj->efile.reloc_sects);
|
|
obj->efile.nr_reloc_sects = 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)
|
|
{
|
|
int err = 0;
|
|
GElf_Ehdr *ep;
|
|
|
|
if (obj_elf_valid(obj)) {
|
|
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().
|
|
*/
|
|
obj->efile.elf = elf_memory((char *)obj->efile.obj_buf,
|
|
obj->efile.obj_buf_sz);
|
|
} else {
|
|
obj->efile.fd = open(obj->path, O_RDONLY);
|
|
if (obj->efile.fd < 0) {
|
|
char errmsg[STRERR_BUFSIZE], *cp;
|
|
|
|
err = -errno;
|
|
cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
|
|
pr_warn("failed to open %s: %s\n", obj->path, cp);
|
|
return err;
|
|
}
|
|
|
|
obj->efile.elf = elf_begin(obj->efile.fd,
|
|
LIBBPF_ELF_C_READ_MMAP, NULL);
|
|
}
|
|
|
|
if (!obj->efile.elf) {
|
|
pr_warn("failed to open %s as ELF file\n", obj->path);
|
|
err = -LIBBPF_ERRNO__LIBELF;
|
|
goto errout;
|
|
}
|
|
|
|
if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
|
|
pr_warn("failed to get EHDR from %s\n", obj->path);
|
|
err = -LIBBPF_ERRNO__FORMAT;
|
|
goto errout;
|
|
}
|
|
ep = &obj->efile.ehdr;
|
|
|
|
/* Old LLVM set e_machine to EM_NONE */
|
|
if (ep->e_type != ET_REL ||
|
|
(ep->e_machine && ep->e_machine != EM_BPF)) {
|
|
pr_warn("%s is not an 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 == __LITTLE_ENDIAN
|
|
if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2LSB)
|
|
return 0;
|
|
#elif __BYTE_ORDER == __BIG_ENDIAN
|
|
if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2MSB)
|
|
return 0;
|
|
#else
|
|
# error "Unrecognized __BYTE_ORDER__"
|
|
#endif
|
|
pr_warn("endianness mismatch.\n");
|
|
return -LIBBPF_ERRNO__ENDIAN;
|
|
}
|
|
|
|
static int
|
|
bpf_object__init_license(struct bpf_object *obj, void *data, size_t size)
|
|
{
|
|
memcpy(obj->license, data, min(size, sizeof(obj->license) - 1));
|
|
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 bpf_object_search_section_size(const struct bpf_object *obj,
|
|
const char *name, size_t *d_size)
|
|
{
|
|
const GElf_Ehdr *ep = &obj->efile.ehdr;
|
|
Elf *elf = obj->efile.elf;
|
|
Elf_Scn *scn = NULL;
|
|
int idx = 0;
|
|
|
|
while ((scn = elf_nextscn(elf, scn)) != NULL) {
|
|
const char *sec_name;
|
|
Elf_Data *data;
|
|
GElf_Shdr sh;
|
|
|
|
idx++;
|
|
if (gelf_getshdr(scn, &sh) != &sh) {
|
|
pr_warn("failed to get section(%d) header from %s\n",
|
|
idx, obj->path);
|
|
return -EIO;
|
|
}
|
|
|
|
sec_name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
|
|
if (!sec_name) {
|
|
pr_warn("failed to get section(%d) name from %s\n",
|
|
idx, obj->path);
|
|
return -EIO;
|
|
}
|
|
|
|
if (strcmp(name, sec_name))
|
|
continue;
|
|
|
|
data = elf_getdata(scn, 0);
|
|
if (!data) {
|
|
pr_warn("failed to get section(%d) data from %s(%s)\n",
|
|
idx, name, obj->path);
|
|
return -EIO;
|
|
}
|
|
|
|
*d_size = data->d_size;
|
|
return 0;
|
|
}
|
|
|
|
return -ENOENT;
|
|
}
|
|
|
|
int bpf_object__section_size(const struct bpf_object *obj, const char *name,
|
|
__u32 *size)
|
|
{
|
|
int ret = -ENOENT;
|
|
size_t d_size;
|
|
|
|
*size = 0;
|
|
if (!name) {
|
|
return -EINVAL;
|
|
} else if (!strcmp(name, DATA_SEC)) {
|
|
if (obj->efile.data)
|
|
*size = obj->efile.data->d_size;
|
|
} else if (!strcmp(name, BSS_SEC)) {
|
|
if (obj->efile.bss)
|
|
*size = obj->efile.bss->d_size;
|
|
} else if (!strcmp(name, RODATA_SEC)) {
|
|
if (obj->efile.rodata)
|
|
*size = obj->efile.rodata->d_size;
|
|
} else if (!strcmp(name, STRUCT_OPS_SEC)) {
|
|
if (obj->efile.st_ops_data)
|
|
*size = obj->efile.st_ops_data->d_size;
|
|
} else {
|
|
ret = bpf_object_search_section_size(obj, name, &d_size);
|
|
if (!ret)
|
|
*size = d_size;
|
|
}
|
|
|
|
return *size ? 0 : ret;
|
|
}
|
|
|
|
int bpf_object__variable_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(GElf_Sym); si++) {
|
|
GElf_Sym sym;
|
|
|
|
if (!gelf_getsym(symbols, si, &sym))
|
|
continue;
|
|
if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL ||
|
|
GELF_ST_TYPE(sym.st_info) != STT_OBJECT)
|
|
continue;
|
|
|
|
sname = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
|
|
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 *new_maps;
|
|
size_t new_cap;
|
|
int i;
|
|
|
|
if (obj->nr_maps < obj->maps_cap)
|
|
return &obj->maps[obj->nr_maps++];
|
|
|
|
new_cap = max((size_t)4, obj->maps_cap * 3 / 2);
|
|
new_maps = realloc(obj->maps, new_cap * sizeof(*obj->maps));
|
|
if (!new_maps) {
|
|
pr_warn("alloc maps for object failed\n");
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
obj->maps_cap = new_cap;
|
|
obj->maps = new_maps;
|
|
|
|
/* zero out new maps */
|
|
memset(obj->maps + obj->nr_maps, 0,
|
|
(obj->maps_cap - obj->nr_maps) * sizeof(*obj->maps));
|
|
/*
|
|
* fill all fd with -1 so won't close incorrect fd (fd=0 is stdin)
|
|
* when failure (zclose won't close negative fd)).
|
|
*/
|
|
for (i = obj->nr_maps; i < obj->maps_cap; i++) {
|
|
obj->maps[i].fd = -1;
|
|
obj->maps[i].inner_map_fd = -1;
|
|
}
|
|
|
|
return &obj->maps[obj->nr_maps++];
|
|
}
|
|
|
|
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,
|
|
enum libbpf_map_type type)
|
|
{
|
|
char map_name[BPF_OBJ_NAME_LEN], *p;
|
|
const char *sfx = libbpf_type_to_btf_name[type];
|
|
int sfx_len = max((size_t)7, strlen(sfx));
|
|
int 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, libbpf_type_to_btf_name[type]);
|
|
|
|
/* 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_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
|
|
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->name = internal_map_name(obj, type);
|
|
if (!map->name) {
|
|
pr_warn("failed to alloc map name\n");
|
|
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->name);
|
|
return err;
|
|
}
|
|
|
|
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)
|
|
{
|
|
int err;
|
|
|
|
/*
|
|
* Populate obj->maps with libbpf internal maps.
|
|
*/
|
|
if (obj->efile.data_shndx >= 0) {
|
|
err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA,
|
|
obj->efile.data_shndx,
|
|
obj->efile.data->d_buf,
|
|
obj->efile.data->d_size);
|
|
if (err)
|
|
return err;
|
|
}
|
|
if (obj->efile.rodata_shndx >= 0) {
|
|
err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA,
|
|
obj->efile.rodata_shndx,
|
|
obj->efile.rodata->d_buf,
|
|
obj->efile.rodata->d_size);
|
|
if (err)
|
|
return err;
|
|
}
|
|
if (obj->efile.bss_shndx >= 0) {
|
|
err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS,
|
|
obj->efile.bss_shndx,
|
|
NULL,
|
|
obj->efile.bss->d_size);
|
|
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_ext_value_tri(struct extern_desc *ext, void *ext_val,
|
|
char value)
|
|
{
|
|
switch (ext->type) {
|
|
case EXT_BOOL:
|
|
if (value == 'm') {
|
|
pr_warn("extern %s=%c should be tristate or char\n",
|
|
ext->name, value);
|
|
return -EINVAL;
|
|
}
|
|
*(bool *)ext_val = value == 'y' ? true : false;
|
|
break;
|
|
case EXT_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 EXT_CHAR:
|
|
*(char *)ext_val = value;
|
|
break;
|
|
case EXT_UNKNOWN:
|
|
case EXT_INT:
|
|
case EXT_CHAR_ARR:
|
|
default:
|
|
pr_warn("extern %s=%c should be bool, tristate, or char\n",
|
|
ext->name, value);
|
|
return -EINVAL;
|
|
}
|
|
ext->is_set = true;
|
|
return 0;
|
|
}
|
|
|
|
static int set_ext_value_str(struct extern_desc *ext, char *ext_val,
|
|
const char *value)
|
|
{
|
|
size_t len;
|
|
|
|
if (ext->type != EXT_CHAR_ARR) {
|
|
pr_warn("extern %s=%s should char array\n", ext->name, value);
|
|
return -EINVAL;
|
|
}
|
|
|
|
len = strlen(value);
|
|
if (value[len - 1] != '"') {
|
|
pr_warn("extern '%s': invalid string config '%s'\n",
|
|
ext->name, value);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* strip quotes */
|
|
len -= 2;
|
|
if (len >= ext->sz) {
|
|
pr_warn("extern '%s': long string config %s of (%zu bytes) truncated to %d bytes\n",
|
|
ext->name, value, len, ext->sz - 1);
|
|
len = ext->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_ext_value_in_range(const struct extern_desc *ext, __u64 v)
|
|
{
|
|
int bit_sz = ext->sz * 8;
|
|
|
|
if (ext->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->is_signed)
|
|
return v + (1ULL << (bit_sz - 1)) < (1ULL << bit_sz);
|
|
else
|
|
return (v >> bit_sz) == 0;
|
|
}
|
|
|
|
static int set_ext_value_num(struct extern_desc *ext, void *ext_val,
|
|
__u64 value)
|
|
{
|
|
if (ext->type != EXT_INT && ext->type != EXT_CHAR) {
|
|
pr_warn("extern %s=%llu should be integer\n",
|
|
ext->name, (unsigned long long)value);
|
|
return -EINVAL;
|
|
}
|
|
if (!is_ext_value_in_range(ext, value)) {
|
|
pr_warn("extern %s=%llu value doesn't fit in %d bytes\n",
|
|
ext->name, (unsigned long long)value, ext->sz);
|
|
return -ERANGE;
|
|
}
|
|
switch (ext->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 (strncmp(buf, "CONFIG_", 7))
|
|
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->data_off;
|
|
value = sep + 1;
|
|
|
|
switch (*value) {
|
|
case 'y': case 'n': case 'm':
|
|
err = set_ext_value_tri(ext, ext_val, *value);
|
|
break;
|
|
case '"':
|
|
err = set_ext_value_str(ext, ext_val, value);
|
|
break;
|
|
default:
|
|
/* assume integer */
|
|
err = parse_u64(value, &num);
|
|
if (err) {
|
|
pr_warn("extern %s=%s should be integer\n",
|
|
ext->name, value);
|
|
return err;
|
|
}
|
|
err = set_ext_value_num(ext, ext_val, num);
|
|
break;
|
|
}
|
|
if (err)
|
|
return err;
|
|
pr_debug("extern %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;
|
|
size_t map_sz;
|
|
int err;
|
|
|
|
if (obj->nr_extern == 0)
|
|
return 0;
|
|
|
|
last_ext = &obj->externs[obj->nr_extern - 1];
|
|
map_sz = last_ext->data_off + last_ext->sz;
|
|
|
|
err = bpf_object__init_internal_map(obj, LIBBPF_MAP_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 (!symbols)
|
|
return -EINVAL;
|
|
|
|
scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx);
|
|
if (scn)
|
|
data = elf_getdata(scn, NULL);
|
|
if (!scn || !data) {
|
|
pr_warn("failed to get Elf_Data from map section %d\n",
|
|
obj->efile.maps_shndx);
|
|
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(GElf_Sym);
|
|
for (i = 0; i < nr_syms; i++) {
|
|
GElf_Sym sym;
|
|
|
|
if (!gelf_getsym(symbols, i, &sym))
|
|
continue;
|
|
if (sym.st_shndx != obj->efile.maps_shndx)
|
|
continue;
|
|
nr_maps++;
|
|
}
|
|
/* Assume equally sized map definitions */
|
|
pr_debug("maps in %s: %d maps in %zd bytes\n",
|
|
obj->path, nr_maps, data->d_size);
|
|
|
|
if (!data->d_size || nr_maps == 0 || (data->d_size % nr_maps) != 0) {
|
|
pr_warn("unable to determine map definition size section %s, %d maps in %zd bytes\n",
|
|
obj->path, nr_maps, data->d_size);
|
|
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++) {
|
|
GElf_Sym sym;
|
|
const char *map_name;
|
|
struct bpf_map_def *def;
|
|
struct bpf_map *map;
|
|
|
|
if (!gelf_getsym(symbols, i, &sym))
|
|
continue;
|
|
if (sym.st_shndx != obj->efile.maps_shndx)
|
|
continue;
|
|
|
|
map = bpf_object__add_map(obj);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
|
|
map_name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
|
|
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;
|
|
}
|
|
|
|
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("failed to alloc map name\n");
|
|
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));
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static 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;
|
|
}
|
|
|
|
/*
|
|
* 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 %u.\n",
|
|
map_name, name, btf_kind(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 %u.\n",
|
|
map_name, name, btf_kind(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 err, 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;
|
|
|
|
err = bpf_map__set_pin_path(map, buf);
|
|
if (err)
|
|
return err;
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int parse_btf_map_def(struct bpf_object *obj,
|
|
struct bpf_map *map,
|
|
const struct btf_type *def,
|
|
bool strict, bool is_inner,
|
|
const char *pin_root_path)
|
|
{
|
|
const struct btf_type *t;
|
|
const struct btf_member *m;
|
|
int vlen, i;
|
|
|
|
vlen = btf_vlen(def);
|
|
m = btf_members(def);
|
|
for (i = 0; i < vlen; i++, m++) {
|
|
const char *name = btf__name_by_offset(obj->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, obj->btf, m,
|
|
&map->def.type))
|
|
return -EINVAL;
|
|
pr_debug("map '%s': found type = %u.\n",
|
|
map->name, map->def.type);
|
|
} else if (strcmp(name, "max_entries") == 0) {
|
|
if (!get_map_field_int(map->name, obj->btf, m,
|
|
&map->def.max_entries))
|
|
return -EINVAL;
|
|
pr_debug("map '%s': found max_entries = %u.\n",
|
|
map->name, map->def.max_entries);
|
|
} else if (strcmp(name, "map_flags") == 0) {
|
|
if (!get_map_field_int(map->name, obj->btf, m,
|
|
&map->def.map_flags))
|
|
return -EINVAL;
|
|
pr_debug("map '%s': found map_flags = %u.\n",
|
|
map->name, map->def.map_flags);
|
|
} else if (strcmp(name, "key_size") == 0) {
|
|
__u32 sz;
|
|
|
|
if (!get_map_field_int(map->name, obj->btf, m, &sz))
|
|
return -EINVAL;
|
|
pr_debug("map '%s': found key_size = %u.\n",
|
|
map->name, sz);
|
|
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;
|
|
} else if (strcmp(name, "key") == 0) {
|
|
__s64 sz;
|
|
|
|
t = btf__type_by_id(obj->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: %u.\n",
|
|
map->name, btf_kind(t));
|
|
return -EINVAL;
|
|
}
|
|
sz = btf__resolve_size(obj->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;
|
|
}
|
|
pr_debug("map '%s': found key [%u], sz = %zd.\n",
|
|
map->name, t->type, (ssize_t)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->btf_key_type_id = t->type;
|
|
} else if (strcmp(name, "value_size") == 0) {
|
|
__u32 sz;
|
|
|
|
if (!get_map_field_int(map->name, obj->btf, m, &sz))
|
|
return -EINVAL;
|
|
pr_debug("map '%s': found value_size = %u.\n",
|
|
map->name, sz);
|
|
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;
|
|
} else if (strcmp(name, "value") == 0) {
|
|
__s64 sz;
|
|
|
|
t = btf__type_by_id(obj->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: %u.\n",
|
|
map->name, btf_kind(t));
|
|
return -EINVAL;
|
|
}
|
|
sz = btf__resolve_size(obj->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;
|
|
}
|
|
pr_debug("map '%s': found value [%u], sz = %zd.\n",
|
|
map->name, t->type, (ssize_t)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->btf_value_type_id = t->type;
|
|
}
|
|
else if (strcmp(name, "values") == 0) {
|
|
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 (!bpf_map_type__is_map_in_map(map->def.type)) {
|
|
pr_warn("map '%s': should be map-in-map.\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(obj->btf, m->type);
|
|
if (!t) {
|
|
pr_warn("map '%s': map-in-map inner type [%d] not found.\n",
|
|
map->name, m->type);
|
|
return -EINVAL;
|
|
}
|
|
if (!btf_is_array(t) || btf_array(t)->nelems) {
|
|
pr_warn("map '%s': map-in-map inner spec is not a zero-sized array.\n",
|
|
map->name);
|
|
return -EINVAL;
|
|
}
|
|
t = skip_mods_and_typedefs(obj->btf, btf_array(t)->type,
|
|
NULL);
|
|
if (!btf_is_ptr(t)) {
|
|
pr_warn("map '%s': map-in-map inner def is of unexpected kind %u.\n",
|
|
map->name, btf_kind(t));
|
|
return -EINVAL;
|
|
}
|
|
t = skip_mods_and_typedefs(obj->btf, t->type, NULL);
|
|
if (!btf_is_struct(t)) {
|
|
pr_warn("map '%s': map-in-map inner def is of unexpected kind %u.\n",
|
|
map->name, btf_kind(t));
|
|
return -EINVAL;
|
|
}
|
|
|
|
map->inner_map = calloc(1, sizeof(*map->inner_map));
|
|
if (!map->inner_map)
|
|
return -ENOMEM;
|
|
map->inner_map->sec_idx = obj->efile.btf_maps_shndx;
|
|
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);
|
|
|
|
err = parse_btf_map_def(obj, map->inner_map, t, strict,
|
|
true /* is_inner */, NULL);
|
|
if (err)
|
|
return err;
|
|
} else if (strcmp(name, "pinning") == 0) {
|
|
__u32 val;
|
|
int err;
|
|
|
|
if (is_inner) {
|
|
pr_debug("map '%s': inner def can't be pinned.\n",
|
|
map->name);
|
|
return -EINVAL;
|
|
}
|
|
if (!get_map_field_int(map->name, obj->btf, m, &val))
|
|
return -EINVAL;
|
|
pr_debug("map '%s': found pinning = %u.\n",
|
|
map->name, val);
|
|
|
|
if (val != LIBBPF_PIN_NONE &&
|
|
val != LIBBPF_PIN_BY_NAME) {
|
|
pr_warn("map '%s': invalid pinning value %u.\n",
|
|
map->name, val);
|
|
return -EINVAL;
|
|
}
|
|
if (val == 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;
|
|
}
|
|
}
|
|
} 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.type == BPF_MAP_TYPE_UNSPEC) {
|
|
pr_warn("map '%s': map type isn't specified.\n", map->name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
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)
|
|
{
|
|
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;
|
|
|
|
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 %u.\n",
|
|
map_name, btf_kind(var));
|
|
return -EINVAL;
|
|
}
|
|
if (var_extra->linkage != BTF_VAR_GLOBAL_ALLOCATED &&
|
|
var_extra->linkage != BTF_VAR_STATIC) {
|
|
pr_warn("map '%s': unsupported var linkage %u.\n",
|
|
map_name, 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 %u.\n",
|
|
map_name, btf_kind(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);
|
|
|
|
return parse_btf_map_def(obj, map, def, strict, false, pin_root_path);
|
|
}
|
|
|
|
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_getscn(obj->efile.elf, obj->efile.btf_maps_shndx);
|
|
if (scn)
|
|
data = elf_getdata(scn, NULL);
|
|
if (!scn || !data) {
|
|
pr_warn("failed to get Elf_Data from map section %d (%s)\n",
|
|
obj->efile.maps_shndx, MAPS_ELF_SEC);
|
|
return -EINVAL;
|
|
}
|
|
|
|
nr_types = btf__get_nr_types(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);
|
|
if (err)
|
|
return err;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool section_have_execinstr(struct bpf_object *obj, int idx)
|
|
{
|
|
Elf_Scn *scn;
|
|
GElf_Shdr sh;
|
|
|
|
scn = elf_getscn(obj->efile.elf, idx);
|
|
if (!scn)
|
|
return false;
|
|
|
|
if (gelf_getshdr(scn, &sh) != &sh)
|
|
return false;
|
|
|
|
if (sh.sh_flags & SHF_EXECINSTR)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static void bpf_object__sanitize_btf(struct bpf_object *obj)
|
|
{
|
|
bool has_func_global = obj->caps.btf_func_global;
|
|
bool has_datasec = obj->caps.btf_datasec;
|
|
bool has_func = obj->caps.btf_func;
|
|
struct btf *btf = obj->btf;
|
|
struct btf_type *t;
|
|
int i, j, vlen;
|
|
|
|
if (!obj->btf || (has_func && has_datasec && has_func_global))
|
|
return;
|
|
|
|
for (i = 1; i <= btf__get_nr_types(btf); i++) {
|
|
t = (struct btf_type *)btf__type_by_id(btf, i);
|
|
|
|
if (!has_datasec && btf_is_var(t)) {
|
|
/* replace VAR 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);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void bpf_object__sanitize_btf_ext(struct bpf_object *obj)
|
|
{
|
|
if (!obj->btf_ext)
|
|
return;
|
|
|
|
if (!obj->caps.btf_func) {
|
|
btf_ext__free(obj->btf_ext);
|
|
obj->btf_ext = NULL;
|
|
}
|
|
}
|
|
|
|
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);
|
|
if (IS_ERR(obj->btf)) {
|
|
err = PTR_ERR(obj->btf);
|
|
obj->btf = NULL;
|
|
pr_warn("Error loading ELF section %s: %d.\n",
|
|
BTF_ELF_SEC, err);
|
|
goto out;
|
|
}
|
|
err = 0;
|
|
}
|
|
if (btf_ext_data) {
|
|
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);
|
|
if (IS_ERR(obj->btf_ext)) {
|
|
pr_warn("Error loading ELF section %s: %ld. Ignored and continue.\n",
|
|
BTF_EXT_ELF_SEC, PTR_ERR(obj->btf_ext));
|
|
obj->btf_ext = NULL;
|
|
goto out;
|
|
}
|
|
}
|
|
out:
|
|
if (err && libbpf_needs_btf(obj)) {
|
|
pr_warn("BTF is required, but is missing or corrupted.\n");
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
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)
|
|
return 0;
|
|
|
|
pr_warn("Error finalizing %s: %d.\n", BTF_ELF_SEC, err);
|
|
btf__free(obj->btf);
|
|
obj->btf = NULL;
|
|
btf_ext__free(obj->btf_ext);
|
|
obj->btf_ext = NULL;
|
|
|
|
if (libbpf_needs_btf(obj)) {
|
|
pr_warn("BTF is required, but is missing or corrupted.\n");
|
|
return -ENOENT;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static inline bool libbpf_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 int bpf_object__load_vmlinux_btf(struct bpf_object *obj)
|
|
{
|
|
struct bpf_program *prog;
|
|
int err;
|
|
|
|
bpf_object__for_each_program(prog, obj) {
|
|
if (libbpf_prog_needs_vmlinux_btf(prog)) {
|
|
obj->btf_vmlinux = libbpf_find_kernel_btf();
|
|
if (IS_ERR(obj->btf_vmlinux)) {
|
|
err = PTR_ERR(obj->btf_vmlinux);
|
|
pr_warn("Error loading vmlinux BTF: %d\n", err);
|
|
obj->btf_vmlinux = NULL;
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
|
|
{
|
|
int err = 0;
|
|
|
|
if (!obj->btf)
|
|
return 0;
|
|
|
|
bpf_object__sanitize_btf(obj);
|
|
bpf_object__sanitize_btf_ext(obj);
|
|
|
|
err = btf__load(obj->btf);
|
|
if (err) {
|
|
pr_warn("Error loading %s into kernel: %d.\n",
|
|
BTF_ELF_SEC, err);
|
|
btf__free(obj->btf);
|
|
obj->btf = NULL;
|
|
/* btf_ext can't exist without btf, so free it as well */
|
|
if (obj->btf_ext) {
|
|
btf_ext__free(obj->btf_ext);
|
|
obj->btf_ext = NULL;
|
|
}
|
|
|
|
if (kernel_needs_btf(obj))
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__elf_collect(struct bpf_object *obj)
|
|
{
|
|
Elf *elf = obj->efile.elf;
|
|
GElf_Ehdr *ep = &obj->efile.ehdr;
|
|
Elf_Data *btf_ext_data = NULL;
|
|
Elf_Data *btf_data = NULL;
|
|
Elf_Scn *scn = NULL;
|
|
int idx = 0, err = 0;
|
|
|
|
/* Elf is corrupted/truncated, avoid calling elf_strptr. */
|
|
if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) {
|
|
pr_warn("failed to get e_shstrndx from %s\n", obj->path);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
while ((scn = elf_nextscn(elf, scn)) != NULL) {
|
|
char *name;
|
|
GElf_Shdr sh;
|
|
Elf_Data *data;
|
|
|
|
idx++;
|
|
if (gelf_getshdr(scn, &sh) != &sh) {
|
|
pr_warn("failed to get section(%d) header from %s\n",
|
|
idx, obj->path);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
|
|
if (!name) {
|
|
pr_warn("failed to get section(%d) name from %s\n",
|
|
idx, obj->path);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
data = elf_getdata(scn, 0);
|
|
if (!data) {
|
|
pr_warn("failed to get section(%d) data from %s(%s)\n",
|
|
idx, name, obj->path);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
pr_debug("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) {
|
|
btf_data = data;
|
|
} else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
|
|
btf_ext_data = data;
|
|
} else if (sh.sh_type == SHT_SYMTAB) {
|
|
if (obj->efile.symbols) {
|
|
pr_warn("bpf: multiple SYMTAB in %s\n",
|
|
obj->path);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
obj->efile.symbols = data;
|
|
obj->efile.symbols_shndx = idx;
|
|
obj->efile.strtabidx = sh.sh_link;
|
|
} 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_program(obj, data->d_buf,
|
|
data->d_size,
|
|
name, idx);
|
|
if (err) {
|
|
char errmsg[STRERR_BUFSIZE];
|
|
char *cp;
|
|
|
|
cp = libbpf_strerror_r(-err, errmsg,
|
|
sizeof(errmsg));
|
|
pr_warn("failed to alloc program %s (%s): %s",
|
|
name, obj->path, cp);
|
|
return err;
|
|
}
|
|
} else if (strcmp(name, DATA_SEC) == 0) {
|
|
obj->efile.data = data;
|
|
obj->efile.data_shndx = idx;
|
|
} else if (strcmp(name, RODATA_SEC) == 0) {
|
|
obj->efile.rodata = data;
|
|
obj->efile.rodata_shndx = idx;
|
|
} else if (strcmp(name, STRUCT_OPS_SEC) == 0) {
|
|
obj->efile.st_ops_data = data;
|
|
obj->efile.st_ops_shndx = idx;
|
|
} else {
|
|
pr_debug("skip section(%d) %s\n", idx, name);
|
|
}
|
|
} else if (sh.sh_type == SHT_REL) {
|
|
int nr_sects = obj->efile.nr_reloc_sects;
|
|
void *sects = obj->efile.reloc_sects;
|
|
int sec = sh.sh_info; /* points to other section */
|
|
|
|
/* Only do relo for section with exec instructions */
|
|
if (!section_have_execinstr(obj, sec) &&
|
|
strcmp(name, ".rel" STRUCT_OPS_SEC) &&
|
|
strcmp(name, ".rel" MAPS_ELF_SEC)) {
|
|
pr_debug("skip relo %s(%d) for section(%d)\n",
|
|
name, idx, sec);
|
|
continue;
|
|
}
|
|
|
|
sects = reallocarray(sects, nr_sects + 1,
|
|
sizeof(*obj->efile.reloc_sects));
|
|
if (!sects) {
|
|
pr_warn("reloc_sects realloc failed\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
obj->efile.reloc_sects = sects;
|
|
obj->efile.nr_reloc_sects++;
|
|
|
|
obj->efile.reloc_sects[nr_sects].shdr = sh;
|
|
obj->efile.reloc_sects[nr_sects].data = data;
|
|
} else if (sh.sh_type == SHT_NOBITS &&
|
|
strcmp(name, BSS_SEC) == 0) {
|
|
obj->efile.bss = data;
|
|
obj->efile.bss_shndx = idx;
|
|
} else {
|
|
pr_debug("skip section(%d) %s\n", idx, name);
|
|
}
|
|
}
|
|
|
|
if (!obj->efile.strtabidx || obj->efile.strtabidx > idx) {
|
|
pr_warn("Corrupted ELF file: index of strtab invalid\n");
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
return bpf_object__init_btf(obj, btf_data, btf_ext_data);
|
|
}
|
|
|
|
static bool sym_is_extern(const GElf_Sym *sym)
|
|
{
|
|
int bind = GELF_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) &&
|
|
GELF_ST_TYPE(sym->st_info) == STT_NOTYPE;
|
|
}
|
|
|
|
static int find_extern_btf_id(const struct btf *btf, const char *ext_name)
|
|
{
|
|
const struct btf_type *t;
|
|
const char *var_name;
|
|
int i, n;
|
|
|
|
if (!btf)
|
|
return -ESRCH;
|
|
|
|
n = btf__get_nr_types(btf);
|
|
for (i = 1; i <= n; i++) {
|
|
t = btf__type_by_id(btf, i);
|
|
|
|
if (!btf_is_var(t))
|
|
continue;
|
|
|
|
var_name = btf__name_by_offset(btf, t->name_off);
|
|
if (strcmp(var_name, ext_name))
|
|
continue;
|
|
|
|
if (btf_var(t)->linkage != BTF_VAR_GLOBAL_EXTERN)
|
|
return -EINVAL;
|
|
|
|
return i;
|
|
}
|
|
|
|
return -ENOENT;
|
|
}
|
|
|
|
static enum extern_type find_extern_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 ? EXT_BOOL : EXT_UNKNOWN;
|
|
if (is_signed)
|
|
*is_signed = enc & BTF_INT_SIGNED;
|
|
if (t->size == 1)
|
|
return EXT_CHAR;
|
|
if (t->size < 1 || t->size > 8 || (t->size & (t->size - 1)))
|
|
return EXT_UNKNOWN;
|
|
return EXT_INT;
|
|
}
|
|
case BTF_KIND_ENUM:
|
|
if (t->size != 4)
|
|
return EXT_UNKNOWN;
|
|
if (strcmp(name, "libbpf_tristate"))
|
|
return EXT_UNKNOWN;
|
|
return EXT_TRISTATE;
|
|
case BTF_KIND_ARRAY:
|
|
if (btf_array(t)->nelems == 0)
|
|
return EXT_UNKNOWN;
|
|
if (find_extern_type(btf, btf_array(t)->type, NULL) != EXT_CHAR)
|
|
return EXT_UNKNOWN;
|
|
return EXT_CHAR_ARR;
|
|
default:
|
|
return EXT_UNKNOWN;
|
|
}
|
|
}
|
|
|
|
static int cmp_externs(const void *_a, const void *_b)
|
|
{
|
|
const struct extern_desc *a = _a;
|
|
const struct extern_desc *b = _b;
|
|
|
|
/* descending order by alignment requirements */
|
|
if (a->align != b->align)
|
|
return a->align > b->align ? -1 : 1;
|
|
/* ascending order by size, within same alignment class */
|
|
if (a->sz != b->sz)
|
|
return a->sz < b->sz ? -1 : 1;
|
|
/* resolve ties by name */
|
|
return strcmp(a->name, b->name);
|
|
}
|
|
|
|
static int bpf_object__collect_externs(struct bpf_object *obj)
|
|
{
|
|
const struct btf_type *t;
|
|
struct extern_desc *ext;
|
|
int i, n, off, btf_id;
|
|
struct btf_type *sec;
|
|
const char *ext_name;
|
|
Elf_Scn *scn;
|
|
GElf_Shdr sh;
|
|
|
|
if (!obj->efile.symbols)
|
|
return 0;
|
|
|
|
scn = elf_getscn(obj->efile.elf, obj->efile.symbols_shndx);
|
|
if (!scn)
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
if (gelf_getshdr(scn, &sh) != &sh)
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
n = sh.sh_size / sh.sh_entsize;
|
|
|
|
pr_debug("looking for externs among %d symbols...\n", n);
|
|
for (i = 0; i < n; i++) {
|
|
GElf_Sym sym;
|
|
|
|
if (!gelf_getsym(obj->efile.symbols, i, &sym))
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
if (!sym_is_extern(&sym))
|
|
continue;
|
|
ext_name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
|
|
sym.st_name);
|
|
if (!ext_name || !ext_name[0])
|
|
continue;
|
|
|
|
ext = obj->externs;
|
|
ext = 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 = GELF_ST_BIND(sym.st_info) == STB_WEAK;
|
|
ext->sz = btf__resolve_size(obj->btf, t->type);
|
|
if (ext->sz <= 0) {
|
|
pr_warn("failed to resolve size of extern '%s': %d\n",
|
|
ext_name, ext->sz);
|
|
return ext->sz;
|
|
}
|
|
ext->align = btf__align_of(obj->btf, t->type);
|
|
if (ext->align <= 0) {
|
|
pr_warn("failed to determine alignment of extern '%s': %d\n",
|
|
ext_name, ext->align);
|
|
return -EINVAL;
|
|
}
|
|
ext->type = find_extern_type(obj->btf, t->type,
|
|
&ext->is_signed);
|
|
if (ext->type == EXT_UNKNOWN) {
|
|
pr_warn("extern '%s' type is unsupported\n", ext_name);
|
|
return -ENOTSUP;
|
|
}
|
|
}
|
|
pr_debug("collected %d externs total\n", obj->nr_extern);
|
|
|
|
if (!obj->nr_extern)
|
|
return 0;
|
|
|
|
/* sort externs by (alignment, size, name) and calculate their offsets
|
|
* within a map */
|
|
qsort(obj->externs, obj->nr_extern, sizeof(*ext), cmp_externs);
|
|
off = 0;
|
|
for (i = 0; i < obj->nr_extern; i++) {
|
|
ext = &obj->externs[i];
|
|
ext->data_off = roundup(off, ext->align);
|
|
off = ext->data_off + ext->sz;
|
|
pr_debug("extern #%d: symbol %d, off %u, name %s\n",
|
|
i, ext->sym_idx, ext->data_off, ext->name);
|
|
}
|
|
|
|
btf_id = btf__find_by_name(obj->btf, KCONFIG_SEC);
|
|
if (btf_id <= 0) {
|
|
pr_warn("no BTF info found for '%s' datasec\n", KCONFIG_SEC);
|
|
return -ESRCH;
|
|
}
|
|
|
|
sec = (struct btf_type *)btf__type_by_id(obj->btf, btf_id);
|
|
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;
|
|
}
|
|
vs->offset = ext->data_off;
|
|
btf_var(t)->linkage = BTF_VAR_GLOBAL_ALLOCATED;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct bpf_program *
|
|
bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx)
|
|
{
|
|
struct bpf_program *prog;
|
|
size_t i;
|
|
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
prog = &obj->programs[i];
|
|
if (prog->idx == idx)
|
|
return prog;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
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->section_name && !strcmp(pos->section_name, title))
|
|
return pos;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
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 (!strcmp(prog->name, name))
|
|
return prog;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static bool bpf_object__shndx_is_data(const struct bpf_object *obj,
|
|
int shndx)
|
|
{
|
|
return shndx == obj->efile.data_shndx ||
|
|
shndx == obj->efile.bss_shndx ||
|
|
shndx == obj->efile.rodata_shndx;
|
|
}
|
|
|
|
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.data_shndx)
|
|
return LIBBPF_MAP_DATA;
|
|
else if (shndx == obj->efile.bss_shndx)
|
|
return LIBBPF_MAP_BSS;
|
|
else if (shndx == obj->efile.rodata_shndx)
|
|
return LIBBPF_MAP_RODATA;
|
|
else if (shndx == obj->efile.symbols_shndx)
|
|
return LIBBPF_MAP_KCONFIG;
|
|
else
|
|
return LIBBPF_MAP_UNSPEC;
|
|
}
|
|
|
|
static int bpf_program__record_reloc(struct bpf_program *prog,
|
|
struct reloc_desc *reloc_desc,
|
|
__u32 insn_idx, const char *name,
|
|
const GElf_Sym *sym, const GElf_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;
|
|
struct bpf_map *map;
|
|
|
|
/* sub-program call relocation */
|
|
if (insn->code == (BPF_JMP | BPF_CALL)) {
|
|
if (insn->src_reg != BPF_PSEUDO_CALL) {
|
|
pr_warn("incorrect bpf_call opcode\n");
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
/* text_shndx can be 0, if no default "main" program exists */
|
|
if (!shdr_idx || shdr_idx != obj->efile.text_shndx) {
|
|
pr_warn("bad call relo against section %u\n", shdr_idx);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
if (sym->st_value % 8) {
|
|
pr_warn("bad call relo offset: %zu\n",
|
|
(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;
|
|
obj->has_pseudo_calls = true;
|
|
return 0;
|
|
}
|
|
|
|
if (insn->code != (BPF_LD | BPF_IMM | BPF_DW)) {
|
|
pr_warn("invalid relo for insns[%d].code 0x%x\n",
|
|
insn_idx, insn->code);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
|
|
if (sym_is_extern(sym)) {
|
|
int sym_idx = GELF_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("extern relo failed to find extern for sym %d\n",
|
|
sym_idx);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
pr_debug("found extern #%d '%s' (sym %d, off %u) for insn %u\n",
|
|
i, ext->name, ext->sym_idx, ext->data_off, insn_idx);
|
|
reloc_desc->type = RELO_EXTERN;
|
|
reloc_desc->insn_idx = insn_idx;
|
|
reloc_desc->sym_off = ext->data_off;
|
|
return 0;
|
|
}
|
|
|
|
if (!shdr_idx || shdr_idx >= SHN_LORESERVE) {
|
|
pr_warn("invalid relo for \'%s\' in special section 0x%x; forgot to initialize global var?..\n",
|
|
name, shdr_idx);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
|
|
type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx);
|
|
|
|
/* generic map reference relocation */
|
|
if (type == LIBBPF_MAP_UNSPEC) {
|
|
if (!bpf_object__shndx_is_maps(obj, shdr_idx)) {
|
|
pr_warn("bad map relo against section %u\n",
|
|
shdr_idx);
|
|
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("found map %zd (%s, sec %d, off %zu) for insn %u\n",
|
|
map_idx, map->name, map->sec_idx,
|
|
map->sec_offset, insn_idx);
|
|
break;
|
|
}
|
|
if (map_idx >= nr_maps) {
|
|
pr_warn("map relo failed to find map for sec %u, off %zu\n",
|
|
shdr_idx, (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("bad data relo against section %u\n", shdr_idx);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
for (map_idx = 0; map_idx < nr_maps; map_idx++) {
|
|
map = &obj->maps[map_idx];
|
|
if (map->libbpf_type != type)
|
|
continue;
|
|
pr_debug("found data map %zd (%s, sec %d, off %zu) for insn %u\n",
|
|
map_idx, map->name, map->sec_idx, map->sec_offset,
|
|
insn_idx);
|
|
break;
|
|
}
|
|
if (map_idx >= nr_maps) {
|
|
pr_warn("data relo failed to find map for sec %u\n",
|
|
shdr_idx);
|
|
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 int
|
|
bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
|
|
Elf_Data *data, struct bpf_object *obj)
|
|
{
|
|
Elf_Data *symbols = obj->efile.symbols;
|
|
int err, i, nrels;
|
|
|
|
pr_debug("collecting relocating info for: '%s'\n", prog->section_name);
|
|
nrels = shdr->sh_size / shdr->sh_entsize;
|
|
|
|
prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels);
|
|
if (!prog->reloc_desc) {
|
|
pr_warn("failed to alloc memory in relocation\n");
|
|
return -ENOMEM;
|
|
}
|
|
prog->nr_reloc = nrels;
|
|
|
|
for (i = 0; i < nrels; i++) {
|
|
const char *name;
|
|
__u32 insn_idx;
|
|
GElf_Sym sym;
|
|
GElf_Rel rel;
|
|
|
|
if (!gelf_getrel(data, i, &rel)) {
|
|
pr_warn("relocation: failed to get %d reloc\n", i);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
|
|
pr_warn("relocation: symbol %"PRIx64" not found\n",
|
|
GELF_R_SYM(rel.r_info));
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
if (rel.r_offset % sizeof(struct bpf_insn))
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
|
|
insn_idx = rel.r_offset / sizeof(struct bpf_insn);
|
|
name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
|
|
sym.st_name) ? : "<?>";
|
|
|
|
pr_debug("relo for shdr %u, symb %zu, value %zu, type %d, bind %d, name %d (\'%s\'), insn %u\n",
|
|
(__u32)sym.st_shndx, (size_t)GELF_R_SYM(rel.r_info),
|
|
(size_t)sym.st_value, GELF_ST_TYPE(sym.st_info),
|
|
GELF_ST_BIND(sym.st_info), sym.st_name, name,
|
|
insn_idx);
|
|
|
|
err = bpf_program__record_reloc(prog, &prog->reloc_desc[i],
|
|
insn_idx, name, &sym, &rel);
|
|
if (err)
|
|
return err;
|
|
}
|
|
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 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)) {
|
|
ret = btf__get_map_kv_tids(obj->btf, map->name, def->key_size,
|
|
def->value_size, &key_type_id,
|
|
&value_type_id);
|
|
} else {
|
|
/*
|
|
* LLVM annotates global data differently in BTF, that is,
|
|
* only as '.data', '.bss' or '.rodata'.
|
|
*/
|
|
ret = btf__find_by_name(obj->btf,
|
|
libbpf_type_to_btf_name[map->libbpf_type]);
|
|
}
|
|
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;
|
|
}
|
|
|
|
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)
|
|
return err;
|
|
|
|
new_name = strdup(info.name);
|
|
if (!new_name)
|
|
return -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;
|
|
|
|
return 0;
|
|
|
|
err_close_new_fd:
|
|
close(new_fd);
|
|
err_free_new_name:
|
|
free(new_name);
|
|
return err;
|
|
}
|
|
|
|
int bpf_map__resize(struct bpf_map *map, __u32 max_entries)
|
|
{
|
|
if (!map || !max_entries)
|
|
return -EINVAL;
|
|
|
|
/* If map already created, its attributes can't be changed. */
|
|
if (map->fd >= 0)
|
|
return -EBUSY;
|
|
|
|
map->def.max_entries = max_entries;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_object__probe_loading(struct bpf_object *obj)
|
|
{
|
|
struct bpf_load_program_attr attr;
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
struct bpf_insn insns[] = {
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
BPF_EXIT_INSN(),
|
|
};
|
|
int ret;
|
|
|
|
/* make sure basic loading works */
|
|
|
|
memset(&attr, 0, sizeof(attr));
|
|
attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
|
|
attr.insns = insns;
|
|
attr.insns_cnt = ARRAY_SIZE(insns);
|
|
attr.license = "GPL";
|
|
|
|
ret = bpf_load_program_xattr(&attr, NULL, 0);
|
|
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
|
|
bpf_object__probe_name(struct bpf_object *obj)
|
|
{
|
|
struct bpf_load_program_attr attr;
|
|
struct bpf_insn insns[] = {
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
BPF_EXIT_INSN(),
|
|
};
|
|
int ret;
|
|
|
|
/* make sure loading with name works */
|
|
|
|
memset(&attr, 0, sizeof(attr));
|
|
attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
|
|
attr.insns = insns;
|
|
attr.insns_cnt = ARRAY_SIZE(insns);
|
|
attr.license = "GPL";
|
|
attr.name = "test";
|
|
ret = bpf_load_program_xattr(&attr, NULL, 0);
|
|
if (ret >= 0) {
|
|
obj->caps.name = 1;
|
|
close(ret);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_object__probe_global_data(struct bpf_object *obj)
|
|
{
|
|
struct bpf_load_program_attr prg_attr;
|
|
struct bpf_create_map_attr map_attr;
|
|
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;
|
|
|
|
memset(&map_attr, 0, sizeof(map_attr));
|
|
map_attr.map_type = BPF_MAP_TYPE_ARRAY;
|
|
map_attr.key_size = sizeof(int);
|
|
map_attr.value_size = 32;
|
|
map_attr.max_entries = 1;
|
|
|
|
map = bpf_create_map_xattr(&map_attr);
|
|
if (map < 0) {
|
|
cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
|
|
pr_warn("Error in %s():%s(%d). Couldn't create simple array map.\n",
|
|
__func__, cp, errno);
|
|
return -errno;
|
|
}
|
|
|
|
insns[0].imm = map;
|
|
|
|
memset(&prg_attr, 0, sizeof(prg_attr));
|
|
prg_attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
|
|
prg_attr.insns = insns;
|
|
prg_attr.insns_cnt = ARRAY_SIZE(insns);
|
|
prg_attr.license = "GPL";
|
|
|
|
ret = bpf_load_program_xattr(&prg_attr, NULL, 0);
|
|
if (ret >= 0) {
|
|
obj->caps.global_data = 1;
|
|
close(ret);
|
|
}
|
|
|
|
close(map);
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__probe_btf_func(struct bpf_object *obj)
|
|
{
|
|
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),
|
|
};
|
|
int btf_fd;
|
|
|
|
btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types),
|
|
strs, sizeof(strs));
|
|
if (btf_fd >= 0) {
|
|
obj->caps.btf_func = 1;
|
|
close(btf_fd);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__probe_btf_func_global(struct bpf_object *obj)
|
|
{
|
|
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),
|
|
};
|
|
int btf_fd;
|
|
|
|
btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types),
|
|
strs, sizeof(strs));
|
|
if (btf_fd >= 0) {
|
|
obj->caps.btf_func_global = 1;
|
|
close(btf_fd);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__probe_btf_datasec(struct bpf_object *obj)
|
|
{
|
|
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),
|
|
};
|
|
int btf_fd;
|
|
|
|
btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types),
|
|
strs, sizeof(strs));
|
|
if (btf_fd >= 0) {
|
|
obj->caps.btf_datasec = 1;
|
|
close(btf_fd);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__probe_array_mmap(struct bpf_object *obj)
|
|
{
|
|
struct bpf_create_map_attr attr = {
|
|
.map_type = BPF_MAP_TYPE_ARRAY,
|
|
.map_flags = BPF_F_MMAPABLE,
|
|
.key_size = sizeof(int),
|
|
.value_size = sizeof(int),
|
|
.max_entries = 1,
|
|
};
|
|
int fd;
|
|
|
|
fd = bpf_create_map_xattr(&attr);
|
|
if (fd >= 0) {
|
|
obj->caps.array_mmap = 1;
|
|
close(fd);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_object__probe_exp_attach_type(struct bpf_object *obj)
|
|
{
|
|
struct bpf_load_program_attr attr;
|
|
struct bpf_insn insns[] = {
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
BPF_EXIT_INSN(),
|
|
};
|
|
int fd;
|
|
|
|
memset(&attr, 0, sizeof(attr));
|
|
/* 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
|
|
*/
|
|
attr.prog_type = BPF_PROG_TYPE_CGROUP_SOCK;
|
|
attr.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE;
|
|
attr.insns = insns;
|
|
attr.insns_cnt = ARRAY_SIZE(insns);
|
|
attr.license = "GPL";
|
|
|
|
fd = bpf_load_program_xattr(&attr, NULL, 0);
|
|
if (fd >= 0) {
|
|
obj->caps.exp_attach_type = 1;
|
|
close(fd);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_object__probe_caps(struct bpf_object *obj)
|
|
{
|
|
int (*probe_fn[])(struct bpf_object *obj) = {
|
|
bpf_object__probe_name,
|
|
bpf_object__probe_global_data,
|
|
bpf_object__probe_btf_func,
|
|
bpf_object__probe_btf_func_global,
|
|
bpf_object__probe_btf_datasec,
|
|
bpf_object__probe_array_mmap,
|
|
bpf_object__probe_exp_attach_type,
|
|
};
|
|
int i, ret;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(probe_fn); i++) {
|
|
ret = probe_fn[i](obj);
|
|
if (ret < 0)
|
|
pr_debug("Probe #%d failed with %d.\n", i, ret);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
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;
|
|
|
|
map_info_len = sizeof(map_info);
|
|
|
|
if (bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len)) {
|
|
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);
|
|
}
|
|
|
|
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);
|
|
if (err) {
|
|
close(pin_fd);
|
|
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;
|
|
|
|
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 int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map)
|
|
{
|
|
struct bpf_create_map_attr create_attr;
|
|
struct bpf_map_def *def = &map->def;
|
|
|
|
memset(&create_attr, 0, sizeof(create_attr));
|
|
|
|
if (obj->caps.name)
|
|
create_attr.name = map->name;
|
|
create_attr.map_ifindex = map->map_ifindex;
|
|
create_attr.map_type = def->type;
|
|
create_attr.map_flags = def->map_flags;
|
|
create_attr.key_size = def->key_size;
|
|
create_attr.value_size = def->value_size;
|
|
|
|
if (def->type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && !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);
|
|
create_attr.max_entries = nr_cpus;
|
|
} else {
|
|
create_attr.max_entries = def->max_entries;
|
|
}
|
|
|
|
if (bpf_map__is_struct_ops(map))
|
|
create_attr.btf_vmlinux_value_type_id =
|
|
map->btf_vmlinux_value_type_id;
|
|
|
|
create_attr.btf_fd = 0;
|
|
create_attr.btf_key_type_id = 0;
|
|
create_attr.btf_value_type_id = 0;
|
|
if (obj->btf && !bpf_map_find_btf_info(obj, map)) {
|
|
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) {
|
|
int err;
|
|
|
|
err = bpf_object__create_map(obj, map->inner_map);
|
|
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;
|
|
}
|
|
|
|
map->fd = bpf_create_map_xattr(&create_attr);
|
|
if (map->fd < 0 && (create_attr.btf_key_type_id ||
|
|
create_attr.btf_value_type_id)) {
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
int 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_create_map_xattr(&create_attr);
|
|
}
|
|
|
|
if (map->fd < 0)
|
|
return -errno;
|
|
|
|
if (bpf_map_type__is_map_in_map(def->type) && map->inner_map) {
|
|
bpf_map__destroy(map->inner_map);
|
|
zfree(&map->inner_map);
|
|
}
|
|
|
|
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;
|
|
|
|
for (i = 0; i < obj->nr_maps; i++) {
|
|
map = &obj->maps[i];
|
|
|
|
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 (map->fd >= 0) {
|
|
pr_debug("map '%s': skipping creation (preset fd=%d)\n",
|
|
map->name, map->fd);
|
|
continue;
|
|
}
|
|
|
|
err = bpf_object__create_map(obj, map);
|
|
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) {
|
|
for (j = 0; j < map->init_slots_sz; j++) {
|
|
const struct bpf_map *targ_map;
|
|
int fd;
|
|
|
|
if (!map->init_slots[j])
|
|
continue;
|
|
|
|
targ_map = map->init_slots[j];
|
|
fd = bpf_map__fd(targ_map);
|
|
err = bpf_map_update_elem(map->fd, &j, &fd, 0);
|
|
if (err) {
|
|
err = -errno;
|
|
pr_warn("map '%s': failed to initialize slot [%d] to map '%s' fd=%d: %d\n",
|
|
map->name, j, targ_map->name,
|
|
fd, err);
|
|
goto err_out;
|
|
}
|
|
pr_debug("map '%s': slot [%d] set to map '%s' fd=%d\n",
|
|
map->name, j, targ_map->name, fd);
|
|
}
|
|
zfree(&map->init_slots);
|
|
map->init_slots_sz = 0;
|
|
}
|
|
|
|
if (map->pin_path && !map->pinned) {
|
|
err = bpf_map__pin(map, NULL);
|
|
if (err) {
|
|
pr_warn("map '%s': failed to auto-pin at '%s': %d\n",
|
|
map->name, map->pin_path, err);
|
|
zclose(map->fd);
|
|
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 int
|
|
check_btf_ext_reloc_err(struct bpf_program *prog, int err,
|
|
void *btf_prog_info, const char *info_name)
|
|
{
|
|
if (err != -ENOENT) {
|
|
pr_warn("Error in loading %s for sec %s.\n",
|
|
info_name, prog->section_name);
|
|
return err;
|
|
}
|
|
|
|
/* err == -ENOENT (i.e. prog->section_name not found in btf_ext) */
|
|
|
|
if (btf_prog_info) {
|
|
/*
|
|
* Some info has already been found but has problem
|
|
* in the last btf_ext reloc. Must have to error out.
|
|
*/
|
|
pr_warn("Error in relocating %s for sec %s.\n",
|
|
info_name, prog->section_name);
|
|
return err;
|
|
}
|
|
|
|
/* Have problem loading the very first info. Ignore the rest. */
|
|
pr_warn("Cannot find %s for main program sec %s. Ignore all %s.\n",
|
|
info_name, prog->section_name, info_name);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_program_reloc_btf_ext(struct bpf_program *prog, struct bpf_object *obj,
|
|
const char *section_name, __u32 insn_offset)
|
|
{
|
|
int err;
|
|
|
|
if (!insn_offset || prog->func_info) {
|
|
/*
|
|
* !insn_offset => main program
|
|
*
|
|
* For sub prog, the main program's func_info has to
|
|
* be loaded first (i.e. prog->func_info != NULL)
|
|
*/
|
|
err = btf_ext__reloc_func_info(obj->btf, obj->btf_ext,
|
|
section_name, insn_offset,
|
|
&prog->func_info,
|
|
&prog->func_info_cnt);
|
|
if (err)
|
|
return check_btf_ext_reloc_err(prog, err,
|
|
prog->func_info,
|
|
"bpf_func_info");
|
|
|
|
prog->func_info_rec_size = btf_ext__func_info_rec_size(obj->btf_ext);
|
|
}
|
|
|
|
if (!insn_offset || prog->line_info) {
|
|
err = btf_ext__reloc_line_info(obj->btf, obj->btf_ext,
|
|
section_name, insn_offset,
|
|
&prog->line_info,
|
|
&prog->line_info_cnt);
|
|
if (err)
|
|
return check_btf_ext_reloc_err(prog, err,
|
|
prog->line_info,
|
|
"bpf_line_info");
|
|
|
|
prog->line_info_rec_size = btf_ext__line_info_rec_size(obj->btf_ext);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define BPF_CORE_SPEC_MAX_LEN 64
|
|
|
|
/* represents BPF CO-RE field or array element accessor */
|
|
struct bpf_core_accessor {
|
|
__u32 type_id; /* struct/union type or array element type */
|
|
__u32 idx; /* field index or array index */
|
|
const char *name; /* field name or NULL for array accessor */
|
|
};
|
|
|
|
struct bpf_core_spec {
|
|
const struct btf *btf;
|
|
/* high-level spec: named fields and array indices only */
|
|
struct bpf_core_accessor spec[BPF_CORE_SPEC_MAX_LEN];
|
|
/* high-level spec length */
|
|
int len;
|
|
/* raw, low-level spec: 1-to-1 with accessor spec string */
|
|
int raw_spec[BPF_CORE_SPEC_MAX_LEN];
|
|
/* raw spec length */
|
|
int raw_len;
|
|
/* field bit offset represented by spec */
|
|
__u32 bit_offset;
|
|
};
|
|
|
|
static bool str_is_empty(const char *s)
|
|
{
|
|
return !s || !s[0];
|
|
}
|
|
|
|
static bool is_flex_arr(const struct btf *btf,
|
|
const struct bpf_core_accessor *acc,
|
|
const struct btf_array *arr)
|
|
{
|
|
const struct btf_type *t;
|
|
|
|
/* not a flexible array, if not inside a struct or has non-zero size */
|
|
if (!acc->name || arr->nelems > 0)
|
|
return false;
|
|
|
|
/* has to be the last member of enclosing struct */
|
|
t = btf__type_by_id(btf, acc->type_id);
|
|
return acc->idx == btf_vlen(t) - 1;
|
|
}
|
|
|
|
/*
|
|
* Turn bpf_field_reloc into a low- and high-level spec representation,
|
|
* validating correctness along the way, as well as calculating resulting
|
|
* field bit offset, specified by accessor string. Low-level spec captures
|
|
* every single level of nestedness, including traversing anonymous
|
|
* struct/union members. High-level one only captures semantically meaningful
|
|
* "turning points": named fields and array indicies.
|
|
* E.g., for this case:
|
|
*
|
|
* struct sample {
|
|
* int __unimportant;
|
|
* struct {
|
|
* int __1;
|
|
* int __2;
|
|
* int a[7];
|
|
* };
|
|
* };
|
|
*
|
|
* struct sample *s = ...;
|
|
*
|
|
* int x = &s->a[3]; // access string = '0:1:2:3'
|
|
*
|
|
* Low-level spec has 1:1 mapping with each element of access string (it's
|
|
* just a parsed access string representation): [0, 1, 2, 3].
|
|
*
|
|
* High-level spec will capture only 3 points:
|
|
* - intial zero-index access by pointer (&s->... is the same as &s[0]...);
|
|
* - field 'a' access (corresponds to '2' in low-level spec);
|
|
* - array element #3 access (corresponds to '3' in low-level spec).
|
|
*
|
|
*/
|
|
static int bpf_core_spec_parse(const struct btf *btf,
|
|
__u32 type_id,
|
|
const char *spec_str,
|
|
struct bpf_core_spec *spec)
|
|
{
|
|
int access_idx, parsed_len, i;
|
|
struct bpf_core_accessor *acc;
|
|
const struct btf_type *t;
|
|
const char *name;
|
|
__u32 id;
|
|
__s64 sz;
|
|
|
|
if (str_is_empty(spec_str) || *spec_str == ':')
|
|
return -EINVAL;
|
|
|
|
memset(spec, 0, sizeof(*spec));
|
|
spec->btf = btf;
|
|
|
|
/* parse spec_str="0:1:2:3:4" into array raw_spec=[0, 1, 2, 3, 4] */
|
|
while (*spec_str) {
|
|
if (*spec_str == ':')
|
|
++spec_str;
|
|
if (sscanf(spec_str, "%d%n", &access_idx, &parsed_len) != 1)
|
|
return -EINVAL;
|
|
if (spec->raw_len == BPF_CORE_SPEC_MAX_LEN)
|
|
return -E2BIG;
|
|
spec_str += parsed_len;
|
|
spec->raw_spec[spec->raw_len++] = access_idx;
|
|
}
|
|
|
|
if (spec->raw_len == 0)
|
|
return -EINVAL;
|
|
|
|
/* first spec value is always reloc type array index */
|
|
t = skip_mods_and_typedefs(btf, type_id, &id);
|
|
if (!t)
|
|
return -EINVAL;
|
|
|
|
access_idx = spec->raw_spec[0];
|
|
spec->spec[0].type_id = id;
|
|
spec->spec[0].idx = access_idx;
|
|
spec->len++;
|
|
|
|
sz = btf__resolve_size(btf, id);
|
|
if (sz < 0)
|
|
return sz;
|
|
spec->bit_offset = access_idx * sz * 8;
|
|
|
|
for (i = 1; i < spec->raw_len; i++) {
|
|
t = skip_mods_and_typedefs(btf, id, &id);
|
|
if (!t)
|
|
return -EINVAL;
|
|
|
|
access_idx = spec->raw_spec[i];
|
|
acc = &spec->spec[spec->len];
|
|
|
|
if (btf_is_composite(t)) {
|
|
const struct btf_member *m;
|
|
__u32 bit_offset;
|
|
|
|
if (access_idx >= btf_vlen(t))
|
|
return -EINVAL;
|
|
|
|
bit_offset = btf_member_bit_offset(t, access_idx);
|
|
spec->bit_offset += bit_offset;
|
|
|
|
m = btf_members(t) + access_idx;
|
|
if (m->name_off) {
|
|
name = btf__name_by_offset(btf, m->name_off);
|
|
if (str_is_empty(name))
|
|
return -EINVAL;
|
|
|
|
acc->type_id = id;
|
|
acc->idx = access_idx;
|
|
acc->name = name;
|
|
spec->len++;
|
|
}
|
|
|
|
id = m->type;
|
|
} else if (btf_is_array(t)) {
|
|
const struct btf_array *a = btf_array(t);
|
|
bool flex;
|
|
|
|
t = skip_mods_and_typedefs(btf, a->type, &id);
|
|
if (!t)
|
|
return -EINVAL;
|
|
|
|
flex = is_flex_arr(btf, acc - 1, a);
|
|
if (!flex && access_idx >= a->nelems)
|
|
return -EINVAL;
|
|
|
|
spec->spec[spec->len].type_id = id;
|
|
spec->spec[spec->len].idx = access_idx;
|
|
spec->len++;
|
|
|
|
sz = btf__resolve_size(btf, id);
|
|
if (sz < 0)
|
|
return sz;
|
|
spec->bit_offset += access_idx * sz * 8;
|
|
} else {
|
|
pr_warn("relo for [%u] %s (at idx %d) captures type [%d] of unexpected kind %d\n",
|
|
type_id, spec_str, i, id, btf_kind(t));
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
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.
|
|
*/
|
|
static 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;
|
|
}
|
|
|
|
/* dynamically sized list of type IDs */
|
|
struct ids_vec {
|
|
__u32 *data;
|
|
int len;
|
|
};
|
|
|
|
static void bpf_core_free_cands(struct ids_vec *cand_ids)
|
|
{
|
|
free(cand_ids->data);
|
|
free(cand_ids);
|
|
}
|
|
|
|
static struct ids_vec *bpf_core_find_cands(const struct btf *local_btf,
|
|
__u32 local_type_id,
|
|
const struct btf *targ_btf)
|
|
{
|
|
size_t local_essent_len, targ_essent_len;
|
|
const char *local_name, *targ_name;
|
|
const struct btf_type *t;
|
|
struct ids_vec *cand_ids;
|
|
__u32 *new_ids;
|
|
int i, err, n;
|
|
|
|
t = btf__type_by_id(local_btf, local_type_id);
|
|
if (!t)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
local_name = btf__name_by_offset(local_btf, t->name_off);
|
|
if (str_is_empty(local_name))
|
|
return ERR_PTR(-EINVAL);
|
|
local_essent_len = bpf_core_essential_name_len(local_name);
|
|
|
|
cand_ids = calloc(1, sizeof(*cand_ids));
|
|
if (!cand_ids)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
n = btf__get_nr_types(targ_btf);
|
|
for (i = 1; i <= n; i++) {
|
|
t = btf__type_by_id(targ_btf, i);
|
|
targ_name = btf__name_by_offset(targ_btf, t->name_off);
|
|
if (str_is_empty(targ_name))
|
|
continue;
|
|
|
|
t = skip_mods_and_typedefs(targ_btf, i, NULL);
|
|
if (!btf_is_composite(t) && !btf_is_array(t))
|
|
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) {
|
|
pr_debug("[%d] %s: found candidate [%d] %s\n",
|
|
local_type_id, local_name, i, targ_name);
|
|
new_ids = reallocarray(cand_ids->data,
|
|
cand_ids->len + 1,
|
|
sizeof(*cand_ids->data));
|
|
if (!new_ids) {
|
|
err = -ENOMEM;
|
|
goto err_out;
|
|
}
|
|
cand_ids->data = new_ids;
|
|
cand_ids->data[cand_ids->len++] = i;
|
|
}
|
|
}
|
|
return cand_ids;
|
|
err_out:
|
|
bpf_core_free_cands(cand_ids);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
/* Check two types for compatibility, skipping const/volatile/restrict and
|
|
* typedefs, to ensure we are relocating compatible entities:
|
|
* - any two STRUCTs/UNIONs are compatible and can be mixed;
|
|
* - any two FWDs are compatible, if their names match (modulo flavor suffix);
|
|
* - any two PTRs are always compatible;
|
|
* - for ENUMs, names should be the same (ignoring flavor suffix) or at
|
|
* least one of enums should be anonymous;
|
|
* - for ENUMs, check sizes, names are ignored;
|
|
* - for INT, size and signedness are ignored;
|
|
* - for ARRAY, dimensionality is ignored, element types are checked for
|
|
* compatibility recursively;
|
|
* - everything else shouldn't be ever a target of relocation.
|
|
* These rules are not set in stone and probably will be adjusted as we get
|
|
* more experience with using BPF CO-RE relocations.
|
|
*/
|
|
static int bpf_core_fields_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;
|
|
|
|
recur:
|
|
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_is_composite(local_type) && btf_is_composite(targ_type))
|
|
return 1;
|
|
if (btf_kind(local_type) != btf_kind(targ_type))
|
|
return 0;
|
|
|
|
switch (btf_kind(local_type)) {
|
|
case BTF_KIND_PTR:
|
|
return 1;
|
|
case BTF_KIND_FWD:
|
|
case BTF_KIND_ENUM: {
|
|
const char *local_name, *targ_name;
|
|
size_t local_len, targ_len;
|
|
|
|
local_name = btf__name_by_offset(local_btf,
|
|
local_type->name_off);
|
|
targ_name = btf__name_by_offset(targ_btf, targ_type->name_off);
|
|
local_len = bpf_core_essential_name_len(local_name);
|
|
targ_len = bpf_core_essential_name_len(targ_name);
|
|
/* one of them is anonymous or both w/ same flavor-less names */
|
|
return local_len == 0 || targ_len == 0 ||
|
|
(local_len == targ_len &&
|
|
strncmp(local_name, targ_name, local_len) == 0);
|
|
}
|
|
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_ARRAY:
|
|
local_id = btf_array(local_type)->type;
|
|
targ_id = btf_array(targ_type)->type;
|
|
goto recur;
|
|
default:
|
|
pr_warn("unexpected kind %d relocated, local [%d], target [%d]\n",
|
|
btf_kind(local_type), local_id, targ_id);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Given single high-level named field accessor in local type, find
|
|
* corresponding high-level accessor for a target type. Along the way,
|
|
* maintain low-level spec for target as well. Also keep updating target
|
|
* bit offset.
|
|
*
|
|
* Searching is performed through recursive exhaustive enumeration of all
|
|
* fields of a struct/union. If there are any anonymous (embedded)
|
|
* structs/unions, they are recursively searched as well. If field with
|
|
* desired name is found, check compatibility between local and target types,
|
|
* before returning result.
|
|
*
|
|
* 1 is returned, if field is found.
|
|
* 0 is returned if no compatible field is found.
|
|
* <0 is returned on error.
|
|
*/
|
|
static int bpf_core_match_member(const struct btf *local_btf,
|
|
const struct bpf_core_accessor *local_acc,
|
|
const struct btf *targ_btf,
|
|
__u32 targ_id,
|
|
struct bpf_core_spec *spec,
|
|
__u32 *next_targ_id)
|
|
{
|
|
const struct btf_type *local_type, *targ_type;
|
|
const struct btf_member *local_member, *m;
|
|
const char *local_name, *targ_name;
|
|
__u32 local_id;
|
|
int i, n, found;
|
|
|
|
targ_type = skip_mods_and_typedefs(targ_btf, targ_id, &targ_id);
|
|
if (!targ_type)
|
|
return -EINVAL;
|
|
if (!btf_is_composite(targ_type))
|
|
return 0;
|
|
|
|
local_id = local_acc->type_id;
|
|
local_type = btf__type_by_id(local_btf, local_id);
|
|
local_member = btf_members(local_type) + local_acc->idx;
|
|
local_name = btf__name_by_offset(local_btf, local_member->name_off);
|
|
|
|
n = btf_vlen(targ_type);
|
|
m = btf_members(targ_type);
|
|
for (i = 0; i < n; i++, m++) {
|
|
__u32 bit_offset;
|
|
|
|
bit_offset = btf_member_bit_offset(targ_type, i);
|
|
|
|
/* too deep struct/union/array nesting */
|
|
if (spec->raw_len == BPF_CORE_SPEC_MAX_LEN)
|
|
return -E2BIG;
|
|
|
|
/* speculate this member will be the good one */
|
|
spec->bit_offset += bit_offset;
|
|
spec->raw_spec[spec->raw_len++] = i;
|
|
|
|
targ_name = btf__name_by_offset(targ_btf, m->name_off);
|
|
if (str_is_empty(targ_name)) {
|
|
/* embedded struct/union, we need to go deeper */
|
|
found = bpf_core_match_member(local_btf, local_acc,
|
|
targ_btf, m->type,
|
|
spec, next_targ_id);
|
|
if (found) /* either found or error */
|
|
return found;
|
|
} else if (strcmp(local_name, targ_name) == 0) {
|
|
/* matching named field */
|
|
struct bpf_core_accessor *targ_acc;
|
|
|
|
targ_acc = &spec->spec[spec->len++];
|
|
targ_acc->type_id = targ_id;
|
|
targ_acc->idx = i;
|
|
targ_acc->name = targ_name;
|
|
|
|
*next_targ_id = m->type;
|
|
found = bpf_core_fields_are_compat(local_btf,
|
|
local_member->type,
|
|
targ_btf, m->type);
|
|
if (!found)
|
|
spec->len--; /* pop accessor */
|
|
return found;
|
|
}
|
|
/* member turned out not to be what we looked for */
|
|
spec->bit_offset -= bit_offset;
|
|
spec->raw_len--;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Try to match local spec to a target type and, if successful, produce full
|
|
* target spec (high-level, low-level + bit offset).
|
|
*/
|
|
static int bpf_core_spec_match(struct bpf_core_spec *local_spec,
|
|
const struct btf *targ_btf, __u32 targ_id,
|
|
struct bpf_core_spec *targ_spec)
|
|
{
|
|
const struct btf_type *targ_type;
|
|
const struct bpf_core_accessor *local_acc;
|
|
struct bpf_core_accessor *targ_acc;
|
|
int i, sz, matched;
|
|
|
|
memset(targ_spec, 0, sizeof(*targ_spec));
|
|
targ_spec->btf = targ_btf;
|
|
|
|
local_acc = &local_spec->spec[0];
|
|
targ_acc = &targ_spec->spec[0];
|
|
|
|
for (i = 0; i < local_spec->len; i++, local_acc++, targ_acc++) {
|
|
targ_type = skip_mods_and_typedefs(targ_spec->btf, targ_id,
|
|
&targ_id);
|
|
if (!targ_type)
|
|
return -EINVAL;
|
|
|
|
if (local_acc->name) {
|
|
matched = bpf_core_match_member(local_spec->btf,
|
|
local_acc,
|
|
targ_btf, targ_id,
|
|
targ_spec, &targ_id);
|
|
if (matched <= 0)
|
|
return matched;
|
|
} else {
|
|
/* for i=0, targ_id is already treated as array element
|
|
* type (because it's the original struct), for others
|
|
* we should find array element type first
|
|
*/
|
|
if (i > 0) {
|
|
const struct btf_array *a;
|
|
bool flex;
|
|
|
|
if (!btf_is_array(targ_type))
|
|
return 0;
|
|
|
|
a = btf_array(targ_type);
|
|
flex = is_flex_arr(targ_btf, targ_acc - 1, a);
|
|
if (!flex && local_acc->idx >= a->nelems)
|
|
return 0;
|
|
if (!skip_mods_and_typedefs(targ_btf, a->type,
|
|
&targ_id))
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* too deep struct/union/array nesting */
|
|
if (targ_spec->raw_len == BPF_CORE_SPEC_MAX_LEN)
|
|
return -E2BIG;
|
|
|
|
targ_acc->type_id = targ_id;
|
|
targ_acc->idx = local_acc->idx;
|
|
targ_acc->name = NULL;
|
|
targ_spec->len++;
|
|
targ_spec->raw_spec[targ_spec->raw_len] = targ_acc->idx;
|
|
targ_spec->raw_len++;
|
|
|
|
sz = btf__resolve_size(targ_btf, targ_id);
|
|
if (sz < 0)
|
|
return sz;
|
|
targ_spec->bit_offset += local_acc->idx * sz * 8;
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int bpf_core_calc_field_relo(const struct bpf_program *prog,
|
|
const struct bpf_field_reloc *relo,
|
|
const struct bpf_core_spec *spec,
|
|
__u32 *val, bool *validate)
|
|
{
|
|
const struct bpf_core_accessor *acc = &spec->spec[spec->len - 1];
|
|
const struct btf_type *t = btf__type_by_id(spec->btf, acc->type_id);
|
|
__u32 byte_off, byte_sz, bit_off, bit_sz;
|
|
const struct btf_member *m;
|
|
const struct btf_type *mt;
|
|
bool bitfield;
|
|
__s64 sz;
|
|
|
|
/* a[n] accessor needs special handling */
|
|
if (!acc->name) {
|
|
if (relo->kind == BPF_FIELD_BYTE_OFFSET) {
|
|
*val = spec->bit_offset / 8;
|
|
} else if (relo->kind == BPF_FIELD_BYTE_SIZE) {
|
|
sz = btf__resolve_size(spec->btf, acc->type_id);
|
|
if (sz < 0)
|
|
return -EINVAL;
|
|
*val = sz;
|
|
} else {
|
|
pr_warn("prog '%s': relo %d at insn #%d can't be applied to array access\n",
|
|
bpf_program__title(prog, false),
|
|
relo->kind, relo->insn_off / 8);
|
|
return -EINVAL;
|
|
}
|
|
if (validate)
|
|
*validate = true;
|
|
return 0;
|
|
}
|
|
|
|
m = btf_members(t) + acc->idx;
|
|
mt = skip_mods_and_typedefs(spec->btf, m->type, NULL);
|
|
bit_off = spec->bit_offset;
|
|
bit_sz = btf_member_bitfield_size(t, acc->idx);
|
|
|
|
bitfield = bit_sz > 0;
|
|
if (bitfield) {
|
|
byte_sz = mt->size;
|
|
byte_off = bit_off / 8 / byte_sz * byte_sz;
|
|
/* figure out smallest int size necessary for bitfield load */
|
|
while (bit_off + bit_sz - byte_off * 8 > byte_sz * 8) {
|
|
if (byte_sz >= 8) {
|
|
/* bitfield can't be read with 64-bit read */
|
|
pr_warn("prog '%s': relo %d at insn #%d can't be satisfied for bitfield\n",
|
|
bpf_program__title(prog, false),
|
|
relo->kind, relo->insn_off / 8);
|
|
return -E2BIG;
|
|
}
|
|
byte_sz *= 2;
|
|
byte_off = bit_off / 8 / byte_sz * byte_sz;
|
|
}
|
|
} else {
|
|
sz = btf__resolve_size(spec->btf, m->type);
|
|
if (sz < 0)
|
|
return -EINVAL;
|
|
byte_sz = sz;
|
|
byte_off = spec->bit_offset / 8;
|
|
bit_sz = byte_sz * 8;
|
|
}
|
|
|
|
/* for bitfields, all the relocatable aspects are ambiguous and we
|
|
* might disagree with compiler, so turn off validation of expected
|
|
* value, except for signedness
|
|
*/
|
|
if (validate)
|
|
*validate = !bitfield;
|
|
|
|
switch (relo->kind) {
|
|
case BPF_FIELD_BYTE_OFFSET:
|
|
*val = byte_off;
|
|
break;
|
|
case BPF_FIELD_BYTE_SIZE:
|
|
*val = byte_sz;
|
|
break;
|
|
case BPF_FIELD_SIGNED:
|
|
/* enums will be assumed unsigned */
|
|
*val = btf_is_enum(mt) ||
|
|
(btf_int_encoding(mt) & BTF_INT_SIGNED);
|
|
if (validate)
|
|
*validate = true; /* signedness is never ambiguous */
|
|
break;
|
|
case BPF_FIELD_LSHIFT_U64:
|
|
#if __BYTE_ORDER == __LITTLE_ENDIAN
|
|
*val = 64 - (bit_off + bit_sz - byte_off * 8);
|
|
#else
|
|
*val = (8 - byte_sz) * 8 + (bit_off - byte_off * 8);
|
|
#endif
|
|
break;
|
|
case BPF_FIELD_RSHIFT_U64:
|
|
*val = 64 - bit_sz;
|
|
if (validate)
|
|
*validate = true; /* right shift is never ambiguous */
|
|
break;
|
|
case BPF_FIELD_EXISTS:
|
|
default:
|
|
pr_warn("prog '%s': unknown relo %d at insn #%d\n",
|
|
bpf_program__title(prog, false),
|
|
relo->kind, relo->insn_off / 8);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Patch relocatable BPF instruction.
|
|
*
|
|
* Patched value is determined by relocation kind and target specification.
|
|
* For field existence relocation target spec will be NULL if field is not
|
|
* found.
|
|
* Expected insn->imm value is determined using relocation kind and local
|
|
* spec, and is checked before patching instruction. If actual insn->imm value
|
|
* is wrong, bail out with error.
|
|
*
|
|
* Currently three kinds of BPF instructions are supported:
|
|
* 1. rX = <imm> (assignment with immediate operand);
|
|
* 2. rX += <imm> (arithmetic operations with immediate operand);
|
|
*/
|
|
static int bpf_core_reloc_insn(struct bpf_program *prog,
|
|
const struct bpf_field_reloc *relo,
|
|
int relo_idx,
|
|
const struct bpf_core_spec *local_spec,
|
|
const struct bpf_core_spec *targ_spec)
|
|
{
|
|
__u32 orig_val, new_val;
|
|
struct bpf_insn *insn;
|
|
bool validate = true;
|
|
int insn_idx, err;
|
|
__u8 class;
|
|
|
|
if (relo->insn_off % sizeof(struct bpf_insn))
|
|
return -EINVAL;
|
|
insn_idx = relo->insn_off / sizeof(struct bpf_insn);
|
|
insn = &prog->insns[insn_idx];
|
|
class = BPF_CLASS(insn->code);
|
|
|
|
if (relo->kind == BPF_FIELD_EXISTS) {
|
|
orig_val = 1; /* can't generate EXISTS relo w/o local field */
|
|
new_val = targ_spec ? 1 : 0;
|
|
} else if (!targ_spec) {
|
|
pr_debug("prog '%s': relo #%d: substituting insn #%d w/ invalid insn\n",
|
|
bpf_program__title(prog, false), relo_idx, insn_idx);
|
|
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 the following message:
|
|
* invalid func unknown#195896080
|
|
*/
|
|
insn->imm = 195896080; /* => 0xbad2310 => "bad relo" */
|
|
return 0;
|
|
} else {
|
|
err = bpf_core_calc_field_relo(prog, relo, local_spec,
|
|
&orig_val, &validate);
|
|
if (err)
|
|
return err;
|
|
err = bpf_core_calc_field_relo(prog, relo, targ_spec,
|
|
&new_val, NULL);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
switch (class) {
|
|
case BPF_ALU:
|
|
case BPF_ALU64:
|
|
if (BPF_SRC(insn->code) != BPF_K)
|
|
return -EINVAL;
|
|
if (validate && insn->imm != orig_val) {
|
|
pr_warn("prog '%s': relo #%d: unexpected insn #%d (ALU/ALU64) value: got %u, exp %u -> %u\n",
|
|
bpf_program__title(prog, false), relo_idx,
|
|
insn_idx, insn->imm, orig_val, new_val);
|
|
return -EINVAL;
|
|
}
|
|
orig_val = insn->imm;
|
|
insn->imm = new_val;
|
|
pr_debug("prog '%s': relo #%d: patched insn #%d (ALU/ALU64) imm %u -> %u\n",
|
|
bpf_program__title(prog, false), relo_idx, insn_idx,
|
|
orig_val, new_val);
|
|
break;
|
|
case BPF_LDX:
|
|
case BPF_ST:
|
|
case BPF_STX:
|
|
if (validate && insn->off != orig_val) {
|
|
pr_warn("prog '%s': relo #%d: unexpected insn #%d (LD/LDX/ST/STX) value: got %u, exp %u -> %u\n",
|
|
bpf_program__title(prog, false), relo_idx,
|
|
insn_idx, insn->off, orig_val, new_val);
|
|
return -EINVAL;
|
|
}
|
|
if (new_val > SHRT_MAX) {
|
|
pr_warn("prog '%s': relo #%d: insn #%d (LDX/ST/STX) value too big: %u\n",
|
|
bpf_program__title(prog, false), relo_idx,
|
|
insn_idx, new_val);
|
|
return -ERANGE;
|
|
}
|
|
orig_val = insn->off;
|
|
insn->off = new_val;
|
|
pr_debug("prog '%s': relo #%d: patched insn #%d (LDX/ST/STX) off %u -> %u\n",
|
|
bpf_program__title(prog, false), relo_idx, insn_idx,
|
|
orig_val, new_val);
|
|
break;
|
|
default:
|
|
pr_warn("prog '%s': relo #%d: trying to relocate unrecognized insn #%d, code:%x, src:%x, dst:%x, off:%x, imm:%x\n",
|
|
bpf_program__title(prog, false), relo_idx,
|
|
insn_idx, insn->code, insn->src_reg, insn->dst_reg,
|
|
insn->off, insn->imm);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Output spec definition in the format:
|
|
* [<type-id>] (<type-name>) + <raw-spec> => <offset>@<spec>,
|
|
* where <spec> is a C-syntax view of recorded field access, e.g.: x.a[3].b
|
|
*/
|
|
static void bpf_core_dump_spec(int level, const struct bpf_core_spec *spec)
|
|
{
|
|
const struct btf_type *t;
|
|
const char *s;
|
|
__u32 type_id;
|
|
int i;
|
|
|
|
type_id = spec->spec[0].type_id;
|
|
t = btf__type_by_id(spec->btf, type_id);
|
|
s = btf__name_by_offset(spec->btf, t->name_off);
|
|
libbpf_print(level, "[%u] %s + ", type_id, s);
|
|
|
|
for (i = 0; i < spec->raw_len; i++)
|
|
libbpf_print(level, "%d%s", spec->raw_spec[i],
|
|
i == spec->raw_len - 1 ? " => " : ":");
|
|
|
|
libbpf_print(level, "%u.%u @ &x",
|
|
spec->bit_offset / 8, spec->bit_offset % 8);
|
|
|
|
for (i = 0; i < spec->len; i++) {
|
|
if (spec->spec[i].name)
|
|
libbpf_print(level, ".%s", spec->spec[i].name);
|
|
else
|
|
libbpf_print(level, "[%u]", spec->spec[i].idx);
|
|
}
|
|
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* CO-RE relocate single instruction.
|
|
*
|
|
* The outline and important points of the algorithm:
|
|
* 1. For given local type, find corresponding candidate target types.
|
|
* Candidate type is a type with the same "essential" name, ignoring
|
|
* everything after last triple underscore (___). E.g., `sample`,
|
|
* `sample___flavor_one`, `sample___flavor_another_one`, are all candidates
|
|
* for each other. Names with triple underscore are referred to as
|
|
* "flavors" and are useful, among other things, to allow to
|
|
* specify/support incompatible variations of the same kernel struct, which
|
|
* might differ between different kernel versions and/or build
|
|
* configurations.
|
|
*
|
|
* N.B. Struct "flavors" could be generated by bpftool's BTF-to-C
|
|
* converter, when deduplicated BTF of a kernel still contains more than
|
|
* one different types with the same name. In that case, ___2, ___3, etc
|
|
* are appended starting from second name conflict. But start flavors are
|
|
* also useful to be defined "locally", in BPF program, to extract same
|
|
* data from incompatible changes between different kernel
|
|
* versions/configurations. For instance, to handle field renames between
|
|
* kernel versions, one can use two flavors of the struct name with the
|
|
* same common name and use conditional relocations to extract that field,
|
|
* depending on target kernel version.
|
|
* 2. For each candidate type, try to match local specification to this
|
|
* candidate target type. Matching involves finding corresponding
|
|
* high-level spec accessors, meaning that all named fields should match,
|
|
* as well as all array accesses should be within the actual bounds. Also,
|
|
* types should be compatible (see bpf_core_fields_are_compat for details).
|
|
* 3. It is supported and expected that there might be multiple flavors
|
|
* matching the spec. As long as all the specs resolve to the same set of
|
|
* offsets across all candidates, there is no error. If there is any
|
|
* ambiguity, CO-RE relocation will fail. This is necessary to accomodate
|
|
* imprefection of BTF deduplication, which can cause slight duplication of
|
|
* the same BTF type, if some directly or indirectly referenced (by
|
|
* pointer) type gets resolved to different actual types in different
|
|
* object files. If such situation occurs, deduplicated BTF will end up
|
|
* with two (or more) structurally identical types, which differ only in
|
|
* types they refer to through pointer. This should be OK in most cases and
|
|
* is not an error.
|
|
* 4. Candidate types search is performed by linearly scanning through all
|
|
* types in target BTF. It is anticipated that this is overall more
|
|
* efficient memory-wise and not significantly worse (if not better)
|
|
* CPU-wise compared to prebuilding a map from all local type names to
|
|
* a list of candidate type names. It's also sped up by caching resolved
|
|
* list of matching candidates per each local "root" type ID, that has at
|
|
* least one bpf_field_reloc associated with it. This list is shared
|
|
* between multiple relocations for the same type ID and is updated as some
|
|
* of the candidates are pruned due to structural incompatibility.
|
|
*/
|
|
static int bpf_core_reloc_field(struct bpf_program *prog,
|
|
const struct bpf_field_reloc *relo,
|
|
int relo_idx,
|
|
const struct btf *local_btf,
|
|
const struct btf *targ_btf,
|
|
struct hashmap *cand_cache)
|
|
{
|
|
const char *prog_name = bpf_program__title(prog, false);
|
|
struct bpf_core_spec local_spec, cand_spec, targ_spec;
|
|
const void *type_key = u32_as_hash_key(relo->type_id);
|
|
const struct btf_type *local_type, *cand_type;
|
|
const char *local_name, *cand_name;
|
|
struct ids_vec *cand_ids;
|
|
__u32 local_id, cand_id;
|
|
const char *spec_str;
|
|
int i, j, err;
|
|
|
|
local_id = relo->type_id;
|
|
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 (str_is_empty(local_name))
|
|
return -EINVAL;
|
|
|
|
spec_str = btf__name_by_offset(local_btf, relo->access_str_off);
|
|
if (str_is_empty(spec_str))
|
|
return -EINVAL;
|
|
|
|
err = bpf_core_spec_parse(local_btf, local_id, spec_str, &local_spec);
|
|
if (err) {
|
|
pr_warn("prog '%s': relo #%d: parsing [%d] %s + %s failed: %d\n",
|
|
prog_name, relo_idx, local_id, local_name, spec_str,
|
|
err);
|
|
return -EINVAL;
|
|
}
|
|
|
|
pr_debug("prog '%s': relo #%d: kind %d, spec is ", prog_name, relo_idx,
|
|
relo->kind);
|
|
bpf_core_dump_spec(LIBBPF_DEBUG, &local_spec);
|
|
libbpf_print(LIBBPF_DEBUG, "\n");
|
|
|
|
if (!hashmap__find(cand_cache, type_key, (void **)&cand_ids)) {
|
|
cand_ids = bpf_core_find_cands(local_btf, local_id, targ_btf);
|
|
if (IS_ERR(cand_ids)) {
|
|
pr_warn("prog '%s': relo #%d: target candidate search failed for [%d] %s: %ld",
|
|
prog_name, relo_idx, local_id, local_name,
|
|
PTR_ERR(cand_ids));
|
|
return PTR_ERR(cand_ids);
|
|
}
|
|
err = hashmap__set(cand_cache, type_key, cand_ids, NULL, NULL);
|
|
if (err) {
|
|
bpf_core_free_cands(cand_ids);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
for (i = 0, j = 0; i < cand_ids->len; i++) {
|
|
cand_id = cand_ids->data[i];
|
|
cand_type = btf__type_by_id(targ_btf, cand_id);
|
|
cand_name = btf__name_by_offset(targ_btf, cand_type->name_off);
|
|
|
|
err = bpf_core_spec_match(&local_spec, targ_btf,
|
|
cand_id, &cand_spec);
|
|
pr_debug("prog '%s': relo #%d: matching candidate #%d %s against spec ",
|
|
prog_name, relo_idx, i, cand_name);
|
|
bpf_core_dump_spec(LIBBPF_DEBUG, &cand_spec);
|
|
libbpf_print(LIBBPF_DEBUG, ": %d\n", err);
|
|
if (err < 0) {
|
|
pr_warn("prog '%s': relo #%d: matching error: %d\n",
|
|
prog_name, relo_idx, err);
|
|
return err;
|
|
}
|
|
if (err == 0)
|
|
continue;
|
|
|
|
if (j == 0) {
|
|
targ_spec = cand_spec;
|
|
} else if (cand_spec.bit_offset != targ_spec.bit_offset) {
|
|
/* if there are many candidates, they should all
|
|
* resolve to the same bit offset
|
|
*/
|
|
pr_warn("prog '%s': relo #%d: offset ambiguity: %u != %u\n",
|
|
prog_name, relo_idx, cand_spec.bit_offset,
|
|
targ_spec.bit_offset);
|
|
return -EINVAL;
|
|
}
|
|
|
|
cand_ids->data[j++] = cand_spec.spec[0].type_id;
|
|
}
|
|
|
|
/*
|
|
* For BPF_FIELD_EXISTS relo or when used BPF program has field
|
|
* existence checks or kernel version/config checks, it's expected
|
|
* that we might not find any candidates. In this case, if field
|
|
* wasn't found in any candidate, the list of candidates shouldn't
|
|
* change at all, we'll just handle relocating appropriately,
|
|
* depending on relo's kind.
|
|
*/
|
|
if (j > 0)
|
|
cand_ids->len = j;
|
|
|
|
/*
|
|
* If no candidates were found, it might be both a programmer error,
|
|
* as well as expected case, depending whether instruction w/
|
|
* relocation is guarded in some way that makes it unreachable (dead
|
|
* code) if relocation can't be resolved. This is handled in
|
|
* bpf_core_reloc_insn() uniformly by replacing that instruction with
|
|
* BPF helper call insn (using invalid helper ID). If that instruction
|
|
* is indeed unreachable, then it will be ignored and eliminated by
|
|
* verifier. If it was an error, then verifier will complain and point
|
|
* to a specific instruction number in its log.
|
|
*/
|
|
if (j == 0)
|
|
pr_debug("prog '%s': relo #%d: no matching targets found for [%d] %s + %s\n",
|
|
prog_name, relo_idx, local_id, local_name, spec_str);
|
|
|
|
/* bpf_core_reloc_insn should know how to handle missing targ_spec */
|
|
err = bpf_core_reloc_insn(prog, relo, relo_idx, &local_spec,
|
|
j ? &targ_spec : NULL);
|
|
if (err) {
|
|
pr_warn("prog '%s': relo #%d: failed to patch insn at offset %d: %d\n",
|
|
prog_name, relo_idx, relo->insn_off, err);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_core_reloc_fields(struct bpf_object *obj, const char *targ_btf_path)
|
|
{
|
|
const struct btf_ext_info_sec *sec;
|
|
const struct bpf_field_reloc *rec;
|
|
const struct btf_ext_info *seg;
|
|
struct hashmap_entry *entry;
|
|
struct hashmap *cand_cache = NULL;
|
|
struct bpf_program *prog;
|
|
struct btf *targ_btf;
|
|
const char *sec_name;
|
|
int i, err = 0;
|
|
|
|
if (targ_btf_path)
|
|
targ_btf = btf__parse_elf(targ_btf_path, NULL);
|
|
else
|
|
targ_btf = libbpf_find_kernel_btf();
|
|
if (IS_ERR(targ_btf)) {
|
|
pr_warn("failed to get target BTF: %ld\n", PTR_ERR(targ_btf));
|
|
return PTR_ERR(targ_btf);
|
|
}
|
|
|
|
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->field_reloc_info;
|
|
for_each_btf_ext_sec(seg, sec) {
|
|
sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
|
|
if (str_is_empty(sec_name)) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
prog = bpf_object__find_program_by_title(obj, sec_name);
|
|
if (!prog) {
|
|
pr_warn("failed to find program '%s' for CO-RE offset relocation\n",
|
|
sec_name);
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
pr_debug("prog '%s': performing %d CO-RE offset relocs\n",
|
|
sec_name, sec->num_info);
|
|
|
|
for_each_btf_ext_rec(seg, sec, i, rec) {
|
|
err = bpf_core_reloc_field(prog, rec, i, obj->btf,
|
|
targ_btf, cand_cache);
|
|
if (err) {
|
|
pr_warn("prog '%s': relo #%d: failed to relocate: %d\n",
|
|
sec_name, i, err);
|
|
goto out;
|
|
}
|
|
}
|
|
}
|
|
|
|
out:
|
|
btf__free(targ_btf);
|
|
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;
|
|
}
|
|
|
|
static int
|
|
bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path)
|
|
{
|
|
int err = 0;
|
|
|
|
if (obj->btf_ext->field_reloc_info.len)
|
|
err = bpf_core_reloc_fields(obj, targ_btf_path);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int
|
|
bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
|
|
struct reloc_desc *relo)
|
|
{
|
|
struct bpf_insn *insn, *new_insn;
|
|
struct bpf_program *text;
|
|
size_t new_cnt;
|
|
int err;
|
|
|
|
if (prog->idx != obj->efile.text_shndx && prog->main_prog_cnt == 0) {
|
|
text = bpf_object__find_prog_by_idx(obj, obj->efile.text_shndx);
|
|
if (!text) {
|
|
pr_warn("no .text section found yet relo into text exist\n");
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
new_cnt = prog->insns_cnt + text->insns_cnt;
|
|
new_insn = reallocarray(prog->insns, new_cnt, sizeof(*insn));
|
|
if (!new_insn) {
|
|
pr_warn("oom in prog realloc\n");
|
|
return -ENOMEM;
|
|
}
|
|
prog->insns = new_insn;
|
|
|
|
if (obj->btf_ext) {
|
|
err = bpf_program_reloc_btf_ext(prog, obj,
|
|
text->section_name,
|
|
prog->insns_cnt);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
memcpy(new_insn + prog->insns_cnt, text->insns,
|
|
text->insns_cnt * sizeof(*insn));
|
|
prog->main_prog_cnt = prog->insns_cnt;
|
|
prog->insns_cnt = new_cnt;
|
|
pr_debug("added %zd insn from %s to prog %s\n",
|
|
text->insns_cnt, text->section_name,
|
|
prog->section_name);
|
|
}
|
|
|
|
insn = &prog->insns[relo->insn_idx];
|
|
insn->imm += relo->sym_off / 8 + prog->main_prog_cnt - relo->insn_idx;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
|
|
{
|
|
int i, err;
|
|
|
|
if (!prog)
|
|
return 0;
|
|
|
|
if (obj->btf_ext) {
|
|
err = bpf_program_reloc_btf_ext(prog, obj,
|
|
prog->section_name, 0);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
if (!prog->reloc_desc)
|
|
return 0;
|
|
|
|
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];
|
|
|
|
if (relo->insn_idx + 1 >= (int)prog->insns_cnt) {
|
|
pr_warn("relocation out of range: '%s'\n",
|
|
prog->section_name);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
|
|
switch (relo->type) {
|
|
case RELO_LD64:
|
|
insn[0].src_reg = BPF_PSEUDO_MAP_FD;
|
|
insn[0].imm = obj->maps[relo->map_idx].fd;
|
|
break;
|
|
case RELO_DATA:
|
|
insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;
|
|
insn[1].imm = insn[0].imm + relo->sym_off;
|
|
insn[0].imm = obj->maps[relo->map_idx].fd;
|
|
break;
|
|
case RELO_EXTERN:
|
|
insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;
|
|
insn[0].imm = obj->maps[obj->kconfig_map_idx].fd;
|
|
insn[1].imm = relo->sym_off;
|
|
break;
|
|
case RELO_CALL:
|
|
err = bpf_program__reloc_text(prog, obj, relo);
|
|
if (err)
|
|
return err;
|
|
break;
|
|
default:
|
|
pr_warn("relo #%d: bad relo type %d\n", i, relo->type);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
zfree(&prog->reloc_desc);
|
|
prog->nr_reloc = 0;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path)
|
|
{
|
|
struct bpf_program *prog;
|
|
size_t i;
|
|
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;
|
|
}
|
|
}
|
|
/* ensure .text is relocated first, as it's going to be copied as-is
|
|
* later for sub-program calls
|
|
*/
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
prog = &obj->programs[i];
|
|
if (prog->idx != obj->efile.text_shndx)
|
|
continue;
|
|
|
|
err = bpf_program__relocate(prog, obj);
|
|
if (err) {
|
|
pr_warn("failed to relocate '%s'\n", prog->section_name);
|
|
return err;
|
|
}
|
|
break;
|
|
}
|
|
/* now relocate everything but .text, which by now is relocated
|
|
* properly, so we can copy raw sub-program instructions as is safely
|
|
*/
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
prog = &obj->programs[i];
|
|
if (prog->idx == obj->efile.text_shndx)
|
|
continue;
|
|
|
|
err = bpf_program__relocate(prog, obj);
|
|
if (err) {
|
|
pr_warn("failed to relocate '%s'\n", prog->section_name);
|
|
return err;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
|
|
GElf_Shdr *shdr, Elf_Data *data);
|
|
|
|
static int bpf_object__collect_map_relos(struct bpf_object *obj,
|
|
GElf_Shdr *shdr, Elf_Data *data)
|
|
{
|
|
int i, j, nrels, new_sz, ptr_sz = sizeof(void *);
|
|
const struct btf_var_secinfo *vi = NULL;
|
|
const struct btf_type *sec, *var, *def;
|
|
const struct btf_member *member;
|
|
struct bpf_map *map, *targ_map;
|
|
const char *name, *mname;
|
|
Elf_Data *symbols;
|
|
unsigned int moff;
|
|
GElf_Sym sym;
|
|
GElf_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;
|
|
|
|
symbols = obj->efile.symbols;
|
|
nrels = shdr->sh_size / shdr->sh_entsize;
|
|
for (i = 0; i < nrels; i++) {
|
|
if (!gelf_getrel(data, i, &rel)) {
|
|
pr_warn(".maps relo #%d: failed to get ELF relo\n", i);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
|
|
pr_warn(".maps relo #%d: symbol %zx not found\n",
|
|
i, (size_t)GELF_R_SYM(rel.r_info));
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
|
|
sym.st_name) ? : "<?>";
|
|
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;
|
|
}
|
|
|
|
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 + sizeof(void *) <= 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;
|
|
}
|
|
|
|
if (!bpf_map_type__is_map_in_map(map->def.type))
|
|
return -EINVAL;
|
|
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)
|
|
return -ESRCH;
|
|
|
|
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;
|
|
if (moff % ptr_sz)
|
|
return -EINVAL;
|
|
moff /= ptr_sz;
|
|
if (moff >= map->init_slots_sz) {
|
|
new_sz = moff + 1;
|
|
tmp = realloc(map->init_slots, new_sz * 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) * ptr_sz);
|
|
map->init_slots_sz = new_sz;
|
|
}
|
|
map->init_slots[moff] = targ_map;
|
|
|
|
pr_debug(".maps relo #%d: map '%s' slot [%d] points to map '%s'\n",
|
|
i, map->name, moff, name);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__collect_reloc(struct bpf_object *obj)
|
|
{
|
|
int i, err;
|
|
|
|
if (!obj_elf_valid(obj)) {
|
|
pr_warn("Internal error: elf object is closed\n");
|
|
return -LIBBPF_ERRNO__INTERNAL;
|
|
}
|
|
|
|
for (i = 0; i < obj->efile.nr_reloc_sects; i++) {
|
|
GElf_Shdr *shdr = &obj->efile.reloc_sects[i].shdr;
|
|
Elf_Data *data = obj->efile.reloc_sects[i].data;
|
|
int idx = shdr->sh_info;
|
|
struct bpf_program *prog;
|
|
|
|
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 {
|
|
prog = bpf_object__find_prog_by_idx(obj, idx);
|
|
if (!prog) {
|
|
pr_warn("relocation failed: no prog in section(%d)\n", idx);
|
|
return -LIBBPF_ERRNO__RELOC;
|
|
}
|
|
err = bpf_program__collect_reloc(prog, shdr, data, obj);
|
|
}
|
|
if (err)
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
|
|
char *license, __u32 kern_version, int *pfd)
|
|
{
|
|
struct bpf_load_program_attr load_attr;
|
|
char *cp, errmsg[STRERR_BUFSIZE];
|
|
size_t log_buf_size = 0;
|
|
char *log_buf = NULL;
|
|
int btf_fd, ret;
|
|
|
|
if (!insns || !insns_cnt)
|
|
return -EINVAL;
|
|
|
|
memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
|
|
load_attr.prog_type = prog->type;
|
|
/* old kernels might not support specifying expected_attach_type */
|
|
if (!prog->caps->exp_attach_type && prog->sec_def &&
|
|
prog->sec_def->is_exp_attach_type_optional)
|
|
load_attr.expected_attach_type = 0;
|
|
else
|
|
load_attr.expected_attach_type = prog->expected_attach_type;
|
|
if (prog->caps->name)
|
|
load_attr.name = prog->name;
|
|
load_attr.insns = insns;
|
|
load_attr.insns_cnt = insns_cnt;
|
|
load_attr.license = license;
|
|
if (prog->type == BPF_PROG_TYPE_STRUCT_OPS ||
|
|
prog->type == BPF_PROG_TYPE_LSM) {
|
|
load_attr.attach_btf_id = prog->attach_btf_id;
|
|
} else if (prog->type == BPF_PROG_TYPE_TRACING ||
|
|
prog->type == BPF_PROG_TYPE_EXT) {
|
|
load_attr.attach_prog_fd = prog->attach_prog_fd;
|
|
load_attr.attach_btf_id = prog->attach_btf_id;
|
|
} else {
|
|
load_attr.kern_version = kern_version;
|
|
load_attr.prog_ifindex = prog->prog_ifindex;
|
|
}
|
|
/* if .BTF.ext was loaded, kernel supports associated BTF for prog */
|
|
if (prog->obj->btf_ext)
|
|
btf_fd = bpf_object__btf_fd(prog->obj);
|
|
else
|
|
btf_fd = -1;
|
|
load_attr.prog_btf_fd = btf_fd >= 0 ? btf_fd : 0;
|
|
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 = prog->log_level;
|
|
load_attr.prog_flags = prog->prog_flags;
|
|
|
|
retry_load:
|
|
if (log_buf_size) {
|
|
log_buf = malloc(log_buf_size);
|
|
if (!log_buf)
|
|
return -ENOMEM;
|
|
|
|
*log_buf = 0;
|
|
}
|
|
|
|
ret = bpf_load_program_xattr(&load_attr, log_buf, log_buf_size);
|
|
|
|
if (ret >= 0) {
|
|
if (log_buf && load_attr.log_level)
|
|
pr_debug("verifier log:\n%s", log_buf);
|
|
*pfd = ret;
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
if (!log_buf || errno == ENOSPC) {
|
|
log_buf_size = max((size_t)BPF_LOG_BUF_SIZE,
|
|
log_buf_size << 1);
|
|
|
|
free(log_buf);
|
|
goto retry_load;
|
|
}
|
|
ret = -errno;
|
|
cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
|
|
pr_warn("load bpf program failed: %s\n", cp);
|
|
pr_perm_msg(ret);
|
|
|
|
if (log_buf && log_buf[0] != '\0') {
|
|
ret = -LIBBPF_ERRNO__VERIFY;
|
|
pr_warn("-- BEGIN DUMP LOG ---\n");
|
|
pr_warn("\n%s\n", log_buf);
|
|
pr_warn("-- END LOG --\n");
|
|
} else if (load_attr.insns_cnt >= BPF_MAXINSNS) {
|
|
pr_warn("Program too large (%zu insns), at most %d insns\n",
|
|
load_attr.insns_cnt, BPF_MAXINSNS);
|
|
ret = -LIBBPF_ERRNO__PROG2BIG;
|
|
} else if (load_attr.prog_type != BPF_PROG_TYPE_KPROBE) {
|
|
/* Wrong program type? */
|
|
int fd;
|
|
|
|
load_attr.prog_type = BPF_PROG_TYPE_KPROBE;
|
|
load_attr.expected_attach_type = 0;
|
|
fd = bpf_load_program_xattr(&load_attr, NULL, 0);
|
|
if (fd >= 0) {
|
|
close(fd);
|
|
ret = -LIBBPF_ERRNO__PROGTYPE;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
out:
|
|
free(log_buf);
|
|
return ret;
|
|
}
|
|
|
|
static int libbpf_find_attach_btf_id(struct bpf_program *prog);
|
|
|
|
int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver)
|
|
{
|
|
int err = 0, fd, i, btf_id;
|
|
|
|
if ((prog->type == BPF_PROG_TYPE_TRACING ||
|
|
prog->type == BPF_PROG_TYPE_LSM ||
|
|
prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) {
|
|
btf_id = libbpf_find_attach_btf_id(prog);
|
|
if (btf_id <= 0)
|
|
return btf_id;
|
|
prog->attach_btf_id = btf_id;
|
|
}
|
|
|
|
if (prog->instances.nr < 0 || !prog->instances.fds) {
|
|
if (prog->preprocessor) {
|
|
pr_warn("Internal error: can't load program '%s'\n",
|
|
prog->section_name);
|
|
return -LIBBPF_ERRNO__INTERNAL;
|
|
}
|
|
|
|
prog->instances.fds = malloc(sizeof(int));
|
|
if (!prog->instances.fds) {
|
|
pr_warn("Not enough memory for BPF fds\n");
|
|
return -ENOMEM;
|
|
}
|
|
prog->instances.nr = 1;
|
|
prog->instances.fds[0] = -1;
|
|
}
|
|
|
|
if (!prog->preprocessor) {
|
|
if (prog->instances.nr != 1) {
|
|
pr_warn("Program '%s' is inconsistent: nr(%d) != 1\n",
|
|
prog->section_name, prog->instances.nr);
|
|
}
|
|
err = load_program(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->section_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->section_name);
|
|
prog->instances.fds[i] = -1;
|
|
if (result.pfd)
|
|
*result.pfd = -1;
|
|
continue;
|
|
}
|
|
|
|
err = load_program(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->section_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->section_name);
|
|
zfree(&prog->insns);
|
|
prog->insns_cnt = 0;
|
|
return err;
|
|
}
|
|
|
|
static bool bpf_program__is_function_storage(const struct bpf_program *prog,
|
|
const struct bpf_object *obj)
|
|
{
|
|
return prog->idx == obj->efile.text_shndx && obj->has_pseudo_calls;
|
|
}
|
|
|
|
static int
|
|
bpf_object__load_progs(struct bpf_object *obj, int log_level)
|
|
{
|
|
size_t i;
|
|
int err;
|
|
|
|
for (i = 0; i < obj->nr_programs; i++) {
|
|
if (bpf_program__is_function_storage(&obj->programs[i], obj))
|
|
continue;
|
|
obj->programs[i].log_level |= log_level;
|
|
err = bpf_program__load(&obj->programs[i],
|
|
obj->license,
|
|
obj->kern_version);
|
|
if (err)
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static const struct bpf_sec_def *find_sec_def(const char *sec_name);
|
|
|
|
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;
|
|
struct bpf_program *prog;
|
|
struct bpf_object *obj;
|
|
char tmp_name[64];
|
|
int err;
|
|
|
|
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);
|
|
}
|
|
|
|
obj = bpf_object__new(path, obj_buf, obj_buf_sz, obj_name);
|
|
if (IS_ERR(obj))
|
|
return obj;
|
|
|
|
kconfig = OPTS_GET(opts, kconfig, NULL);
|
|
if (kconfig) {
|
|
obj->kconfig = strdup(kconfig);
|
|
if (!obj->kconfig)
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
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_prog_names(obj);
|
|
err = err ? : bpf_object__collect_reloc(obj);
|
|
if (err)
|
|
goto out;
|
|
bpf_object__elf_finish(obj);
|
|
|
|
bpf_object__for_each_program(prog, obj) {
|
|
prog->sec_def = find_sec_def(prog->section_name);
|
|
if (!prog->sec_def)
|
|
/* couldn't guess, but user might manually specify */
|
|
continue;
|
|
|
|
bpf_program__set_type(prog, prog->sec_def->prog_type);
|
|
bpf_program__set_expected_attach_type(prog,
|
|
prog->sec_def->expected_attach_type);
|
|
|
|
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);
|
|
}
|
|
|
|
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 __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 bpf_object__open_xattr(&attr);
|
|
}
|
|
|
|
struct bpf_object *
|
|
bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts)
|
|
{
|
|
if (!path)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
pr_debug("loading %s\n", path);
|
|
|
|
return __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 ERR_PTR(-EINVAL);
|
|
|
|
return __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 NULL;
|
|
|
|
return bpf_object__open_mem(obj_buf, obj_buf_sz, &opts);
|
|
}
|
|
|
|
int bpf_object__unload(struct bpf_object *obj)
|
|
{
|
|
size_t i;
|
|
|
|
if (!obj)
|
|
return -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;
|
|
}
|
|
|
|
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 (!obj->caps.global_data) {
|
|
pr_warn("kernel doesn't support global data\n");
|
|
return -ENOTSUP;
|
|
}
|
|
if (!obj->caps.array_mmap)
|
|
m->def.map_flags ^= BPF_F_MMAPABLE;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_object__resolve_externs(struct bpf_object *obj,
|
|
const char *extra_kconfig)
|
|
{
|
|
bool need_config = false;
|
|
struct extern_desc *ext;
|
|
int err, i;
|
|
void *data;
|
|
|
|
if (obj->nr_extern == 0)
|
|
return 0;
|
|
|
|
data = obj->maps[obj->kconfig_map_idx].mmaped;
|
|
|
|
for (i = 0; i < obj->nr_extern; i++) {
|
|
ext = &obj->externs[i];
|
|
|
|
if (strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) {
|
|
void *ext_val = data + ext->data_off;
|
|
__u32 kver = get_kernel_version();
|
|
|
|
if (!kver) {
|
|
pr_warn("failed to get kernel version\n");
|
|
return -EINVAL;
|
|
}
|
|
err = set_ext_value_num(ext, ext_val, kver);
|
|
if (err)
|
|
return err;
|
|
pr_debug("extern %s=0x%x\n", ext->name, kver);
|
|
} else if (strncmp(ext->name, "CONFIG_", 7) == 0) {
|
|
need_config = 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, data);
|
|
if (err)
|
|
return -EINVAL;
|
|
need_config = false;
|
|
for (i = 0; i < obj->nr_extern; i++) {
|
|
ext = &obj->externs[i];
|
|
if (!ext->is_set) {
|
|
need_config = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (need_config) {
|
|
err = bpf_object__read_kconfig_file(obj, data);
|
|
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;
|
|
}
|
|
|
|
int bpf_object__load_xattr(struct bpf_object_load_attr *attr)
|
|
{
|
|
struct bpf_object *obj;
|
|
int err, i;
|
|
|
|
if (!attr)
|
|
return -EINVAL;
|
|
obj = attr->obj;
|
|
if (!obj)
|
|
return -EINVAL;
|
|
|
|
if (obj->loaded) {
|
|
pr_warn("object should not be loaded twice\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
obj->loaded = true;
|
|
|
|
err = bpf_object__probe_loading(obj);
|
|
err = err ? : bpf_object__probe_caps(obj);
|
|
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__load_vmlinux_btf(obj);
|
|
err = err ? : bpf_object__init_kern_struct_ops_maps(obj);
|
|
err = err ? : bpf_object__create_maps(obj);
|
|
err = err ? : bpf_object__relocate(obj, attr->target_btf_path);
|
|
err = err ? : bpf_object__load_progs(obj, attr->log_level);
|
|
|
|
btf__free(obj->btf_vmlinux);
|
|
obj->btf_vmlinux = NULL;
|
|
|
|
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 err;
|
|
}
|
|
|
|
int bpf_object__load(struct bpf_object *obj)
|
|
{
|
|
struct bpf_object_load_attr attr = {
|
|
.obj = obj,
|
|
};
|
|
|
|
return bpf_object__load_xattr(&attr);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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 err;
|
|
|
|
err = check_path(path);
|
|
if (err)
|
|
return err;
|
|
|
|
if (prog == NULL) {
|
|
pr_warn("invalid program pointer\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (instance < 0 || instance >= prog->instances.nr) {
|
|
pr_warn("invalid prog instance %d of prog %s (max %d)\n",
|
|
instance, prog->section_name, prog->instances.nr);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (bpf_obj_pin(prog->instances.fds[instance], path)) {
|
|
cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
|
|
pr_warn("failed to pin program: %s\n", cp);
|
|
return -errno;
|
|
}
|
|
pr_debug("pinned program '%s'\n", path);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bpf_program__unpin_instance(struct bpf_program *prog, const char *path,
|
|
int instance)
|
|
{
|
|
int err;
|
|
|
|
err = check_path(path);
|
|
if (err)
|
|
return err;
|
|
|
|
if (prog == NULL) {
|
|
pr_warn("invalid program pointer\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (instance < 0 || instance >= prog->instances.nr) {
|
|
pr_warn("invalid prog instance %d of prog %s (max %d)\n",
|
|
instance, prog->section_name, prog->instances.nr);
|
|
return -EINVAL;
|
|
}
|
|
|
|
err = unlink(path);
|
|
if (err != 0)
|
|
return -errno;
|
|
pr_debug("unpinned program '%s'\n", path);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bpf_program__pin(struct bpf_program *prog, const char *path)
|
|
{
|
|
int i, err;
|
|
|
|
err = make_parent_dir(path);
|
|
if (err)
|
|
return err;
|
|
|
|
err = check_path(path);
|
|
if (err)
|
|
return err;
|
|
|
|
if (prog == NULL) {
|
|
pr_warn("invalid program pointer\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (prog->instances.nr <= 0) {
|
|
pr_warn("no instances of prog %s to pin\n",
|
|
prog->section_name);
|
|
return -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 err;
|
|
}
|
|
|
|
int bpf_program__unpin(struct bpf_program *prog, const char *path)
|
|
{
|
|
int i, err;
|
|
|
|
err = check_path(path);
|
|
if (err)
|
|
return err;
|
|
|
|
if (prog == NULL) {
|
|
pr_warn("invalid program pointer\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (prog->instances.nr <= 0) {
|
|
pr_warn("no instances of prog %s to pin\n",
|
|
prog->section_name);
|
|
return -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 -EINVAL;
|
|
else if (len >= PATH_MAX)
|
|
return -ENAMETOOLONG;
|
|
|
|
err = bpf_program__unpin_instance(prog, buf, i);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
err = rmdir(path);
|
|
if (err)
|
|
return -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 -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 -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 -EINVAL;
|
|
} else if (map->pinned) {
|
|
pr_warn("map '%s' already pinned\n", bpf_map__name(map));
|
|
return -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 err;
|
|
|
|
err = check_path(map->pin_path);
|
|
if (err)
|
|
return 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 err;
|
|
}
|
|
|
|
int bpf_map__unpin(struct bpf_map *map, const char *path)
|
|
{
|
|
int err;
|
|
|
|
if (map == NULL) {
|
|
pr_warn("invalid map pointer\n");
|
|
return -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 -EINVAL;
|
|
}
|
|
path = map->pin_path;
|
|
} else if (!path) {
|
|
pr_warn("no path to unpin map '%s' from\n",
|
|
bpf_map__name(map));
|
|
return -EINVAL;
|
|
}
|
|
|
|
err = check_path(path);
|
|
if (err)
|
|
return err;
|
|
|
|
err = unlink(path);
|
|
if (err != 0)
|
|
return -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 -errno;
|
|
}
|
|
|
|
free(map->pin_path);
|
|
map->pin_path = new;
|
|
return 0;
|
|
}
|
|
|
|
const char *bpf_map__get_pin_path(const struct bpf_map *map)
|
|
{
|
|
return map->pin_path;
|
|
}
|
|
|
|
bool bpf_map__is_pinned(const struct bpf_map *map)
|
|
{
|
|
return map->pinned;
|
|
}
|
|
|
|
int bpf_object__pin_maps(struct bpf_object *obj, const char *path)
|
|
{
|
|
struct bpf_map *map;
|
|
int err;
|
|
|
|
if (!obj)
|
|
return -ENOENT;
|
|
|
|
if (!obj->loaded) {
|
|
pr_warn("object not yet loaded; load it first\n");
|
|
return -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) {
|
|
err = -EINVAL;
|
|
goto err_unpin_maps;
|
|
} else if (len >= PATH_MAX) {
|
|
err = -ENAMETOOLONG;
|
|
goto err_unpin_maps;
|
|
}
|
|
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_map__prev(map, obj))) {
|
|
if (!map->pin_path)
|
|
continue;
|
|
|
|
bpf_map__unpin(map, NULL);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
int bpf_object__unpin_maps(struct bpf_object *obj, const char *path)
|
|
{
|
|
struct bpf_map *map;
|
|
int err;
|
|
|
|
if (!obj)
|
|
return -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 -EINVAL;
|
|
else if (len >= PATH_MAX)
|
|
return -ENAMETOOLONG;
|
|
pin_path = buf;
|
|
} else if (!map->pin_path) {
|
|
continue;
|
|
}
|
|
|
|
err = bpf_map__unpin(map, pin_path);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bpf_object__pin_programs(struct bpf_object *obj, const char *path)
|
|
{
|
|
struct bpf_program *prog;
|
|
int err;
|
|
|
|
if (!obj)
|
|
return -ENOENT;
|
|
|
|
if (!obj->loaded) {
|
|
pr_warn("object not yet loaded; load it first\n");
|
|
return -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_program__prev(prog, obj))) {
|
|
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 err;
|
|
}
|
|
|
|
int bpf_object__unpin_programs(struct bpf_object *obj, const char *path)
|
|
{
|
|
struct bpf_program *prog;
|
|
int err;
|
|
|
|
if (!obj)
|
|
return -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 -EINVAL;
|
|
else if (len >= PATH_MAX)
|
|
return -ENAMETOOLONG;
|
|
|
|
err = bpf_program__unpin(prog, buf);
|
|
if (err)
|
|
return 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 err;
|
|
|
|
err = bpf_object__pin_programs(obj, path);
|
|
if (err) {
|
|
bpf_object__unpin_maps(obj, path);
|
|
return 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->pin_path);
|
|
|
|
if (map->fd >= 0)
|
|
zclose(map->fd);
|
|
}
|
|
|
|
void bpf_object__close(struct bpf_object *obj)
|
|
{
|
|
size_t i;
|
|
|
|
if (!obj)
|
|
return;
|
|
|
|
if (obj->clear_priv)
|
|
obj->clear_priv(obj, obj->priv);
|
|
|
|
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->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;
|
|
|
|
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 : 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_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 : ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
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 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)
|
|
{
|
|
struct bpf_program *prog = prev;
|
|
|
|
do {
|
|
prog = __bpf_program__iter(prog, obj, true);
|
|
} while (prog && bpf_program__is_function_storage(prog, obj));
|
|
|
|
return prog;
|
|
}
|
|
|
|
struct bpf_program *
|
|
bpf_program__prev(struct bpf_program *next, const struct bpf_object *obj)
|
|
{
|
|
struct bpf_program *prog = next;
|
|
|
|
do {
|
|
prog = __bpf_program__iter(prog, obj, false);
|
|
} while (prog && bpf_program__is_function_storage(prog, obj));
|
|
|
|
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 : 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__title(const struct bpf_program *prog, bool needs_copy)
|
|
{
|
|
const char *title;
|
|
|
|
title = prog->section_name;
|
|
if (needs_copy) {
|
|
title = strdup(title);
|
|
if (!title) {
|
|
pr_warn("failed to strdup program title\n");
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
}
|
|
|
|
return title;
|
|
}
|
|
|
|
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 * sizeof(struct bpf_insn);
|
|
}
|
|
|
|
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 -EINVAL;
|
|
|
|
if (prog->instances.nr > 0 || prog->instances.fds) {
|
|
pr_warn("Can't set pre-processor after loading\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
instances_fds = malloc(sizeof(int) * nr_instances);
|
|
if (!instances_fds) {
|
|
pr_warn("alloc memory failed for fds\n");
|
|
return -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;
|
|
}
|
|
|
|
int bpf_program__nth_fd(const struct bpf_program *prog, int n)
|
|
{
|
|
int fd;
|
|
|
|
if (!prog)
|
|
return -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->section_name, prog->instances.nr);
|
|
return -EINVAL;
|
|
}
|
|
|
|
fd = prog->instances.fds[n];
|
|
if (fd < 0) {
|
|
pr_warn("%dth instance of program '%s' is invalid\n",
|
|
n, prog->section_name);
|
|
return -ENOENT;
|
|
}
|
|
|
|
return fd;
|
|
}
|
|
|
|
enum bpf_prog_type bpf_program__get_type(struct bpf_program *prog)
|
|
{
|
|
return prog->type;
|
|
}
|
|
|
|
void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type)
|
|
{
|
|
prog->type = type;
|
|
}
|
|
|
|
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 -EINVAL; \
|
|
bpf_program__set_type(prog, TYPE); \
|
|
return 0; \
|
|
} \
|
|
\
|
|
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);
|
|
|
|
enum bpf_attach_type
|
|
bpf_program__get_expected_attach_type(struct bpf_program *prog)
|
|
{
|
|
return prog->expected_attach_type;
|
|
}
|
|
|
|
void bpf_program__set_expected_attach_type(struct bpf_program *prog,
|
|
enum bpf_attach_type type)
|
|
{
|
|
prog->expected_attach_type = type;
|
|
}
|
|
|
|
#define BPF_PROG_SEC_IMPL(string, ptype, eatype, eatype_optional, \
|
|
attachable, attach_btf) \
|
|
{ \
|
|
.sec = string, \
|
|
.len = sizeof(string) - 1, \
|
|
.prog_type = ptype, \
|
|
.expected_attach_type = eatype, \
|
|
.is_exp_attach_type_optional = eatype_optional, \
|
|
.is_attachable = attachable, \
|
|
.is_attach_btf = attach_btf, \
|
|
}
|
|
|
|
/* Programs that can NOT be attached. */
|
|
#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 0, 0)
|
|
|
|
/* Programs that can be attached. */
|
|
#define BPF_APROG_SEC(string, ptype, atype) \
|
|
BPF_PROG_SEC_IMPL(string, ptype, atype, true, 1, 0)
|
|
|
|
/* Programs that must specify expected attach type at load time. */
|
|
#define BPF_EAPROG_SEC(string, ptype, eatype) \
|
|
BPF_PROG_SEC_IMPL(string, ptype, eatype, false, 1, 0)
|
|
|
|
/* Programs that use BTF to identify attach point */
|
|
#define BPF_PROG_BTF(string, ptype, eatype) \
|
|
BPF_PROG_SEC_IMPL(string, ptype, eatype, false, 0, 1)
|
|
|
|
/* Programs that can be attached but attach type can't be identified by section
|
|
* name. Kept for backward compatibility.
|
|
*/
|
|
#define BPF_APROG_COMPAT(string, ptype) BPF_PROG_SEC(string, ptype)
|
|
|
|
#define SEC_DEF(sec_pfx, ptype, ...) { \
|
|
.sec = sec_pfx, \
|
|
.len = sizeof(sec_pfx) - 1, \
|
|
.prog_type = BPF_PROG_TYPE_##ptype, \
|
|
__VA_ARGS__ \
|
|
}
|
|
|
|
static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec,
|
|
struct bpf_program *prog);
|
|
static struct bpf_link *attach_tp(const struct bpf_sec_def *sec,
|
|
struct bpf_program *prog);
|
|
static struct bpf_link *attach_raw_tp(const struct bpf_sec_def *sec,
|
|
struct bpf_program *prog);
|
|
static struct bpf_link *attach_trace(const struct bpf_sec_def *sec,
|
|
struct bpf_program *prog);
|
|
static struct bpf_link *attach_lsm(const struct bpf_sec_def *sec,
|
|
struct bpf_program *prog);
|
|
static struct bpf_link *attach_iter(const struct bpf_sec_def *sec,
|
|
struct bpf_program *prog);
|
|
|
|
static const struct bpf_sec_def section_defs[] = {
|
|
BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER),
|
|
BPF_PROG_SEC("sk_reuseport", BPF_PROG_TYPE_SK_REUSEPORT),
|
|
SEC_DEF("kprobe/", KPROBE,
|
|
.attach_fn = attach_kprobe),
|
|
BPF_PROG_SEC("uprobe/", BPF_PROG_TYPE_KPROBE),
|
|
SEC_DEF("kretprobe/", KPROBE,
|
|
.attach_fn = attach_kprobe),
|
|
BPF_PROG_SEC("uretprobe/", BPF_PROG_TYPE_KPROBE),
|
|
BPF_PROG_SEC("classifier", BPF_PROG_TYPE_SCHED_CLS),
|
|
BPF_PROG_SEC("action", BPF_PROG_TYPE_SCHED_ACT),
|
|
SEC_DEF("tracepoint/", TRACEPOINT,
|
|
.attach_fn = attach_tp),
|
|
SEC_DEF("tp/", TRACEPOINT,
|
|
.attach_fn = attach_tp),
|
|
SEC_DEF("raw_tracepoint/", RAW_TRACEPOINT,
|
|
.attach_fn = attach_raw_tp),
|
|
SEC_DEF("raw_tp/", RAW_TRACEPOINT,
|
|
.attach_fn = attach_raw_tp),
|
|
SEC_DEF("tp_btf/", TRACING,
|
|
.expected_attach_type = BPF_TRACE_RAW_TP,
|
|
.is_attach_btf = true,
|
|
.attach_fn = attach_trace),
|
|
SEC_DEF("fentry/", TRACING,
|
|
.expected_attach_type = BPF_TRACE_FENTRY,
|
|
.is_attach_btf = true,
|
|
.attach_fn = attach_trace),
|
|
SEC_DEF("fmod_ret/", TRACING,
|
|
.expected_attach_type = BPF_MODIFY_RETURN,
|
|
.is_attach_btf = true,
|
|
.attach_fn = attach_trace),
|
|
SEC_DEF("fexit/", TRACING,
|
|
.expected_attach_type = BPF_TRACE_FEXIT,
|
|
.is_attach_btf = true,
|
|
.attach_fn = attach_trace),
|
|
SEC_DEF("freplace/", EXT,
|
|
.is_attach_btf = true,
|
|
.attach_fn = attach_trace),
|
|
SEC_DEF("lsm/", LSM,
|
|
.is_attach_btf = true,
|
|
.expected_attach_type = BPF_LSM_MAC,
|
|
.attach_fn = attach_lsm),
|
|
SEC_DEF("iter/", TRACING,
|
|
.expected_attach_type = BPF_TRACE_ITER,
|
|
.is_attach_btf = true,
|
|
.attach_fn = attach_iter),
|
|
BPF_EAPROG_SEC("xdp_devmap", BPF_PROG_TYPE_XDP,
|
|
BPF_XDP_DEVMAP),
|
|
BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP),
|
|
BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT),
|
|
BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN),
|
|
BPF_PROG_SEC("lwt_out", BPF_PROG_TYPE_LWT_OUT),
|
|
BPF_PROG_SEC("lwt_xmit", BPF_PROG_TYPE_LWT_XMIT),
|
|
BPF_PROG_SEC("lwt_seg6local", BPF_PROG_TYPE_LWT_SEG6LOCAL),
|
|
BPF_APROG_SEC("cgroup_skb/ingress", BPF_PROG_TYPE_CGROUP_SKB,
|
|
BPF_CGROUP_INET_INGRESS),
|
|
BPF_APROG_SEC("cgroup_skb/egress", BPF_PROG_TYPE_CGROUP_SKB,
|
|
BPF_CGROUP_INET_EGRESS),
|
|
BPF_APROG_COMPAT("cgroup/skb", BPF_PROG_TYPE_CGROUP_SKB),
|
|
BPF_APROG_SEC("cgroup/sock", BPF_PROG_TYPE_CGROUP_SOCK,
|
|
BPF_CGROUP_INET_SOCK_CREATE),
|
|
BPF_EAPROG_SEC("cgroup/post_bind4", BPF_PROG_TYPE_CGROUP_SOCK,
|
|
BPF_CGROUP_INET4_POST_BIND),
|
|
BPF_EAPROG_SEC("cgroup/post_bind6", BPF_PROG_TYPE_CGROUP_SOCK,
|
|
BPF_CGROUP_INET6_POST_BIND),
|
|
BPF_APROG_SEC("cgroup/dev", BPF_PROG_TYPE_CGROUP_DEVICE,
|
|
BPF_CGROUP_DEVICE),
|
|
BPF_APROG_SEC("sockops", BPF_PROG_TYPE_SOCK_OPS,
|
|
BPF_CGROUP_SOCK_OPS),
|
|
BPF_APROG_SEC("sk_skb/stream_parser", BPF_PROG_TYPE_SK_SKB,
|
|
BPF_SK_SKB_STREAM_PARSER),
|
|
BPF_APROG_SEC("sk_skb/stream_verdict", BPF_PROG_TYPE_SK_SKB,
|
|
BPF_SK_SKB_STREAM_VERDICT),
|
|
BPF_APROG_COMPAT("sk_skb", BPF_PROG_TYPE_SK_SKB),
|
|
BPF_APROG_SEC("sk_msg", BPF_PROG_TYPE_SK_MSG,
|
|
BPF_SK_MSG_VERDICT),
|
|
BPF_APROG_SEC("lirc_mode2", BPF_PROG_TYPE_LIRC_MODE2,
|
|
BPF_LIRC_MODE2),
|
|
BPF_APROG_SEC("flow_dissector", BPF_PROG_TYPE_FLOW_DISSECTOR,
|
|
BPF_FLOW_DISSECTOR),
|
|
BPF_EAPROG_SEC("cgroup/bind4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
|
|
BPF_CGROUP_INET4_BIND),
|
|
BPF_EAPROG_SEC("cgroup/bind6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
|
|
BPF_CGROUP_INET6_BIND),
|
|
BPF_EAPROG_SEC("cgroup/connect4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
|
|
BPF_CGROUP_INET4_CONNECT),
|
|
BPF_EAPROG_SEC("cgroup/connect6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
|
|
BPF_CGROUP_INET6_CONNECT),
|
|
BPF_EAPROG_SEC("cgroup/sendmsg4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
|
|
BPF_CGROUP_UDP4_SENDMSG),
|
|
BPF_EAPROG_SEC("cgroup/sendmsg6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
|
|
BPF_CGROUP_UDP6_SENDMSG),
|
|
BPF_EAPROG_SEC("cgroup/recvmsg4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
|
|
BPF_CGROUP_UDP4_RECVMSG),
|
|
BPF_EAPROG_SEC("cgroup/recvmsg6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
|
|
BPF_CGROUP_UDP6_RECVMSG),
|
|
BPF_EAPROG_SEC("cgroup/getpeername4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
|
|
BPF_CGROUP_INET4_GETPEERNAME),
|
|
BPF_EAPROG_SEC("cgroup/getpeername6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
|
|
BPF_CGROUP_INET6_GETPEERNAME),
|
|
BPF_EAPROG_SEC("cgroup/getsockname4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
|
|
BPF_CGROUP_INET4_GETSOCKNAME),
|
|
BPF_EAPROG_SEC("cgroup/getsockname6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
|
|
BPF_CGROUP_INET6_GETSOCKNAME),
|
|
BPF_EAPROG_SEC("cgroup/sysctl", BPF_PROG_TYPE_CGROUP_SYSCTL,
|
|
BPF_CGROUP_SYSCTL),
|
|
BPF_EAPROG_SEC("cgroup/getsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT,
|
|
BPF_CGROUP_GETSOCKOPT),
|
|
BPF_EAPROG_SEC("cgroup/setsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT,
|
|
BPF_CGROUP_SETSOCKOPT),
|
|
BPF_PROG_SEC("struct_ops", BPF_PROG_TYPE_STRUCT_OPS),
|
|
};
|
|
|
|
#undef BPF_PROG_SEC_IMPL
|
|
#undef BPF_PROG_SEC
|
|
#undef BPF_APROG_SEC
|
|
#undef BPF_EAPROG_SEC
|
|
#undef BPF_APROG_COMPAT
|
|
#undef SEC_DEF
|
|
|
|
#define MAX_TYPE_NAME_SIZE 32
|
|
|
|
static const struct bpf_sec_def *find_sec_def(const char *sec_name)
|
|
{
|
|
int i, n = ARRAY_SIZE(section_defs);
|
|
|
|
for (i = 0; i < n; i++) {
|
|
if (strncmp(sec_name,
|
|
section_defs[i].sec, section_defs[i].len))
|
|
continue;
|
|
return §ion_defs[i];
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
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++) {
|
|
if (attach_type && !section_defs[i].is_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 -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 -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,
|
|
GElf_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;
|
|
Elf_Data *symbols;
|
|
unsigned int moff;
|
|
const char *name;
|
|
__u32 member_idx;
|
|
GElf_Sym sym;
|
|
GElf_Rel rel;
|
|
int i, nrels;
|
|
|
|
symbols = obj->efile.symbols;
|
|
btf = obj->btf;
|
|
nrels = shdr->sh_size / shdr->sh_entsize;
|
|
for (i = 0; i < nrels; i++) {
|
|
if (!gelf_getrel(data, i, &rel)) {
|
|
pr_warn("struct_ops reloc: failed to get %d reloc\n", i);
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
|
|
pr_warn("struct_ops reloc: symbol %zx not found\n",
|
|
(size_t)GELF_R_SYM(rel.r_info));
|
|
return -LIBBPF_ERRNO__FORMAT;
|
|
}
|
|
|
|
name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
|
|
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;
|
|
}
|
|
|
|
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 = bpf_object__find_prog_by_idx(obj, shdr_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;
|
|
}
|
|
|
|
if (prog->type == BPF_PROG_TYPE_UNSPEC) {
|
|
const struct bpf_sec_def *sec_def;
|
|
|
|
sec_def = find_sec_def(prog->section_name);
|
|
if (sec_def &&
|
|
sec_def->prog_type != BPF_PROG_TYPE_STRUCT_OPS) {
|
|
/* for pr_warn */
|
|
prog->type = sec_def->prog_type;
|
|
goto invalid_prog;
|
|
}
|
|
|
|
prog->type = BPF_PROG_TYPE_STRUCT_OPS;
|
|
prog->attach_btf_id = st_ops->type_id;
|
|
prog->expected_attach_type = member_idx;
|
|
} else if (prog->type != BPF_PROG_TYPE_STRUCT_OPS ||
|
|
prog->attach_btf_id != st_ops->type_id ||
|
|
prog->expected_attach_type != member_idx) {
|
|
goto invalid_prog;
|
|
}
|
|
st_ops->progs[member_idx] = prog;
|
|
}
|
|
|
|
return 0;
|
|
|
|
invalid_prog:
|
|
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->section_name, prog->type,
|
|
prog->attach_btf_id, prog->expected_attach_type, name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
#define BTF_TRACE_PREFIX "btf_trace_"
|
|
#define BTF_LSM_PREFIX "bpf_lsm_"
|
|
#define BTF_ITER_PREFIX "bpf_iter_"
|
|
#define BTF_MAX_NAME_SIZE 128
|
|
|
|
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
|
|
* 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_vmlinux_btf_id(struct btf *btf, const char *name,
|
|
enum bpf_attach_type attach_type)
|
|
{
|
|
int err;
|
|
|
|
if (attach_type == BPF_TRACE_RAW_TP)
|
|
err = find_btf_by_prefix_kind(btf, BTF_TRACE_PREFIX, name,
|
|
BTF_KIND_TYPEDEF);
|
|
else if (attach_type == BPF_LSM_MAC)
|
|
err = find_btf_by_prefix_kind(btf, BTF_LSM_PREFIX, name,
|
|
BTF_KIND_FUNC);
|
|
else if (attach_type == BPF_TRACE_ITER)
|
|
err = find_btf_by_prefix_kind(btf, BTF_ITER_PREFIX, name,
|
|
BTF_KIND_FUNC);
|
|
else
|
|
err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC);
|
|
|
|
if (err <= 0)
|
|
pr_warn("%s is not found in vmlinux BTF\n", name);
|
|
|
|
return err;
|
|
}
|
|
|
|
int libbpf_find_vmlinux_btf_id(const char *name,
|
|
enum bpf_attach_type attach_type)
|
|
{
|
|
struct btf *btf;
|
|
int err;
|
|
|
|
btf = libbpf_find_kernel_btf();
|
|
if (IS_ERR(btf)) {
|
|
pr_warn("vmlinux BTF is not found\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
err = __find_vmlinux_btf_id(btf, name, attach_type);
|
|
btf__free(btf);
|
|
return err;
|
|
}
|
|
|
|
static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd)
|
|
{
|
|
struct bpf_prog_info_linear *info_linear;
|
|
struct bpf_prog_info *info;
|
|
struct btf *btf = NULL;
|
|
int err = -EINVAL;
|
|
|
|
info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0);
|
|
if (IS_ERR_OR_NULL(info_linear)) {
|
|
pr_warn("failed get_prog_info_linear for FD %d\n",
|
|
attach_prog_fd);
|
|
return -EINVAL;
|
|
}
|
|
info = &info_linear->info;
|
|
if (!info->btf_id) {
|
|
pr_warn("The target program doesn't have BTF\n");
|
|
goto out;
|
|
}
|
|
if (btf__get_from_id(info->btf_id, &btf)) {
|
|
pr_warn("Failed to get BTF of the program\n");
|
|
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:
|
|
free(info_linear);
|
|
return err;
|
|
}
|
|
|
|
static int libbpf_find_attach_btf_id(struct bpf_program *prog)
|
|
{
|
|
enum bpf_attach_type attach_type = prog->expected_attach_type;
|
|
__u32 attach_prog_fd = prog->attach_prog_fd;
|
|
const char *name = prog->section_name;
|
|
int i, err;
|
|
|
|
if (!name)
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
|
|
if (!section_defs[i].is_attach_btf)
|
|
continue;
|
|
if (strncmp(name, section_defs[i].sec, section_defs[i].len))
|
|
continue;
|
|
if (attach_prog_fd)
|
|
err = libbpf_find_prog_btf_id(name + section_defs[i].len,
|
|
attach_prog_fd);
|
|
else
|
|
err = __find_vmlinux_btf_id(prog->obj->btf_vmlinux,
|
|
name + section_defs[i].len,
|
|
attach_type);
|
|
return err;
|
|
}
|
|
pr_warn("failed to identify btf_id based on ELF section name '%s'\n", name);
|
|
return -ESRCH;
|
|
}
|
|
|
|
int libbpf_attach_type_by_name(const char *name,
|
|
enum bpf_attach_type *attach_type)
|
|
{
|
|
char *type_names;
|
|
int i;
|
|
|
|
if (!name)
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
|
|
if (strncmp(name, section_defs[i].sec, section_defs[i].len))
|
|
continue;
|
|
if (!section_defs[i].is_attachable)
|
|
return -EINVAL;
|
|
*attach_type = section_defs[i].expected_attach_type;
|
|
return 0;
|
|
}
|
|
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 -EINVAL;
|
|
}
|
|
|
|
int bpf_map__fd(const struct bpf_map *map)
|
|
{
|
|
return map ? map->fd : -EINVAL;
|
|
}
|
|
|
|
const struct bpf_map_def *bpf_map__def(const struct bpf_map *map)
|
|
{
|
|
return map ? &map->def : ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
const char *bpf_map__name(const struct bpf_map *map)
|
|
{
|
|
return map ? map->name : NULL;
|
|
}
|
|
|
|
__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 -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 : 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 -EINVAL;
|
|
|
|
memcpy(map->mmaped, data, size);
|
|
return 0;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
|
|
{
|
|
map->map_ifindex = ifindex;
|
|
}
|
|
|
|
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 -EINVAL;
|
|
}
|
|
if (map->inner_map_fd != -1) {
|
|
pr_warn("error: inner_map_fd already specified\n");
|
|
return -EINVAL;
|
|
}
|
|
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 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 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)
|
|
{
|
|
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)
|
|
{
|
|
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 (pos->name && !strcmp(pos->name, name))
|
|
return pos;
|
|
}
|
|
return 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 ERR_PTR(-ENOTSUP);
|
|
}
|
|
|
|
long libbpf_get_error(const void *ptr)
|
|
{
|
|
return PTR_ERR_OR_ZERO(ptr);
|
|
}
|
|
|
|
int bpf_prog_load(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_xattr(&attr, pobj, prog_fd);
|
|
}
|
|
|
|
int bpf_prog_load_xattr(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 -EINVAL;
|
|
if (!attr->file)
|
|
return -EINVAL;
|
|
|
|
open_attr.file = attr->file;
|
|
open_attr.prog_type = attr->prog_type;
|
|
|
|
obj = bpf_object__open_xattr(&open_attr);
|
|
if (IS_ERR_OR_NULL(obj))
|
|
return -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) {
|
|
bpf_program__set_type(prog, attr->prog_type);
|
|
bpf_program__set_expected_attach_type(prog,
|
|
attach_type);
|
|
}
|
|
if (bpf_program__get_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 -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 (!bpf_map__is_offload_neutral(map))
|
|
map->map_ifindex = attr->ifindex;
|
|
}
|
|
|
|
if (!first_prog) {
|
|
pr_warn("object file doesn't contain bpf program\n");
|
|
bpf_object__close(obj);
|
|
return -ENOENT;
|
|
}
|
|
|
|
err = bpf_object__load(obj);
|
|
if (err) {
|
|
bpf_object__close(obj);
|
|
return err;
|
|
}
|
|
|
|
*pobj = obj;
|
|
*prog_fd = bpf_program__fd(first_prog);
|
|
return 0;
|
|
}
|
|
|
|
struct bpf_link {
|
|
int (*detach)(struct bpf_link *link);
|
|
int (*destroy)(struct bpf_link *link);
|
|
char *pin_path; /* NULL, if not pinned */
|
|
int fd; /* hook FD, -1 if not applicable */
|
|
bool disconnected;
|
|
};
|
|
|
|
/* Replace link's underlying BPF program with the new one */
|
|
int bpf_link__update_program(struct bpf_link *link, struct bpf_program *prog)
|
|
{
|
|
return bpf_link_update(bpf_link__fd(link), bpf_program__fd(prog), NULL);
|
|
}
|
|
|
|
/* 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 (!link)
|
|
return 0;
|
|
|
|
if (!link->disconnected && link->detach)
|
|
err = link->detach(link);
|
|
if (link->destroy)
|
|
link->destroy(link);
|
|
if (link->pin_path)
|
|
free(link->pin_path);
|
|
free(link);
|
|
|
|
return 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 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 ERR_PTR(fd);
|
|
}
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link) {
|
|
close(fd);
|
|
return 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 ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
return link;
|
|
}
|
|
|
|
int bpf_link__pin(struct bpf_link *link, const char *path)
|
|
{
|
|
int err;
|
|
|
|
if (link->pin_path)
|
|
return -EBUSY;
|
|
err = make_parent_dir(path);
|
|
if (err)
|
|
return err;
|
|
err = check_path(path);
|
|
if (err)
|
|
return err;
|
|
|
|
link->pin_path = strdup(path);
|
|
if (!link->pin_path)
|
|
return -ENOMEM;
|
|
|
|
if (bpf_obj_pin(link->fd, link->pin_path)) {
|
|
err = -errno;
|
|
zfree(&link->pin_path);
|
|
return 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 -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;
|
|
}
|
|
|
|
static int bpf_link__detach_perf_event(struct bpf_link *link)
|
|
{
|
|
int err;
|
|
|
|
err = ioctl(link->fd, PERF_EVENT_IOC_DISABLE, 0);
|
|
if (err)
|
|
err = -errno;
|
|
|
|
close(link->fd);
|
|
return err;
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog,
|
|
int pfd)
|
|
{
|
|
char errmsg[STRERR_BUFSIZE];
|
|
struct bpf_link *link;
|
|
int prog_fd, err;
|
|
|
|
if (pfd < 0) {
|
|
pr_warn("program '%s': invalid perf event FD %d\n",
|
|
bpf_program__title(prog, false), pfd);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
prog_fd = bpf_program__fd(prog);
|
|
if (prog_fd < 0) {
|
|
pr_warn("program '%s': can't attach BPF program w/o FD (did you load it?)\n",
|
|
bpf_program__title(prog, false));
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link)
|
|
return ERR_PTR(-ENOMEM);
|
|
link->detach = &bpf_link__detach_perf_event;
|
|
link->fd = pfd;
|
|
|
|
if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) {
|
|
err = -errno;
|
|
free(link);
|
|
pr_warn("program '%s': failed to attach to pfd %d: %s\n",
|
|
bpf_program__title(prog, false), pfd,
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
return ERR_PTR(err);
|
|
}
|
|
if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) {
|
|
err = -errno;
|
|
free(link);
|
|
pr_warn("program '%s': failed to enable pfd %d: %s\n",
|
|
bpf_program__title(prog, false), pfd,
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
return ERR_PTR(err);
|
|
}
|
|
return link;
|
|
}
|
|
|
|
/*
|
|
* 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");
|
|
}
|
|
|
|
static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
|
|
uint64_t offset, int pid)
|
|
{
|
|
struct perf_event_attr attr = {};
|
|
char errmsg[STRERR_BUFSIZE];
|
|
int type, pfd, err;
|
|
|
|
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.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;
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
|
|
bool retprobe,
|
|
const char *func_name)
|
|
{
|
|
char errmsg[STRERR_BUFSIZE];
|
|
struct bpf_link *link;
|
|
int pfd, err;
|
|
|
|
pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name,
|
|
0 /* offset */, -1 /* pid */);
|
|
if (pfd < 0) {
|
|
pr_warn("program '%s': failed to create %s '%s' perf event: %s\n",
|
|
bpf_program__title(prog, false),
|
|
retprobe ? "kretprobe" : "kprobe", func_name,
|
|
libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
|
|
return ERR_PTR(pfd);
|
|
}
|
|
link = bpf_program__attach_perf_event(prog, pfd);
|
|
if (IS_ERR(link)) {
|
|
close(pfd);
|
|
err = PTR_ERR(link);
|
|
pr_warn("program '%s': failed to attach to %s '%s': %s\n",
|
|
bpf_program__title(prog, false),
|
|
retprobe ? "kretprobe" : "kprobe", func_name,
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
return link;
|
|
}
|
|
return link;
|
|
}
|
|
|
|
static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec,
|
|
struct bpf_program *prog)
|
|
{
|
|
const char *func_name;
|
|
bool retprobe;
|
|
|
|
func_name = bpf_program__title(prog, false) + sec->len;
|
|
retprobe = strcmp(sec->sec, "kretprobe/") == 0;
|
|
|
|
return bpf_program__attach_kprobe(prog, retprobe, func_name);
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog,
|
|
bool retprobe, pid_t pid,
|
|
const char *binary_path,
|
|
size_t func_offset)
|
|
{
|
|
char errmsg[STRERR_BUFSIZE];
|
|
struct bpf_link *link;
|
|
int pfd, err;
|
|
|
|
pfd = perf_event_open_probe(true /* uprobe */, retprobe,
|
|
binary_path, func_offset, pid);
|
|
if (pfd < 0) {
|
|
pr_warn("program '%s': failed to create %s '%s:0x%zx' perf event: %s\n",
|
|
bpf_program__title(prog, false),
|
|
retprobe ? "uretprobe" : "uprobe",
|
|
binary_path, func_offset,
|
|
libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
|
|
return ERR_PTR(pfd);
|
|
}
|
|
link = bpf_program__attach_perf_event(prog, pfd);
|
|
if (IS_ERR(link)) {
|
|
close(pfd);
|
|
err = PTR_ERR(link);
|
|
pr_warn("program '%s': failed to attach to %s '%s:0x%zx': %s\n",
|
|
bpf_program__title(prog, false),
|
|
retprobe ? "uretprobe" : "uprobe",
|
|
binary_path, func_offset,
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
return link;
|
|
}
|
|
return link;
|
|
}
|
|
|
|
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(struct bpf_program *prog,
|
|
const char *tp_category,
|
|
const char *tp_name)
|
|
{
|
|
char errmsg[STRERR_BUFSIZE];
|
|
struct bpf_link *link;
|
|
int pfd, err;
|
|
|
|
pfd = perf_event_open_tracepoint(tp_category, tp_name);
|
|
if (pfd < 0) {
|
|
pr_warn("program '%s': failed to create tracepoint '%s/%s' perf event: %s\n",
|
|
bpf_program__title(prog, false),
|
|
tp_category, tp_name,
|
|
libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
|
|
return ERR_PTR(pfd);
|
|
}
|
|
link = bpf_program__attach_perf_event(prog, pfd);
|
|
if (IS_ERR(link)) {
|
|
close(pfd);
|
|
err = PTR_ERR(link);
|
|
pr_warn("program '%s': failed to attach to tracepoint '%s/%s': %s\n",
|
|
bpf_program__title(prog, false),
|
|
tp_category, tp_name,
|
|
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
|
|
return link;
|
|
}
|
|
return link;
|
|
}
|
|
|
|
static struct bpf_link *attach_tp(const struct bpf_sec_def *sec,
|
|
struct bpf_program *prog)
|
|
{
|
|
char *sec_name, *tp_cat, *tp_name;
|
|
struct bpf_link *link;
|
|
|
|
sec_name = strdup(bpf_program__title(prog, false));
|
|
if (!sec_name)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
/* extract "tp/<category>/<name>" */
|
|
tp_cat = sec_name + sec->len;
|
|
tp_name = strchr(tp_cat, '/');
|
|
if (!tp_name) {
|
|
link = ERR_PTR(-EINVAL);
|
|
goto out;
|
|
}
|
|
*tp_name = '\0';
|
|
tp_name++;
|
|
|
|
link = bpf_program__attach_tracepoint(prog, tp_cat, tp_name);
|
|
out:
|
|
free(sec_name);
|
|
return link;
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_raw_tracepoint(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("program '%s': can't attach before loaded\n",
|
|
bpf_program__title(prog, false));
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link)
|
|
return 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("program '%s': failed to attach to raw tracepoint '%s': %s\n",
|
|
bpf_program__title(prog, false), tp_name,
|
|
libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
|
|
return ERR_PTR(pfd);
|
|
}
|
|
link->fd = pfd;
|
|
return link;
|
|
}
|
|
|
|
static struct bpf_link *attach_raw_tp(const struct bpf_sec_def *sec,
|
|
struct bpf_program *prog)
|
|
{
|
|
const char *tp_name = bpf_program__title(prog, false) + sec->len;
|
|
|
|
return bpf_program__attach_raw_tracepoint(prog, tp_name);
|
|
}
|
|
|
|
/* Common logic for all BPF program types that attach to a btf_id */
|
|
static struct bpf_link *bpf_program__attach_btf_id(struct bpf_program *prog)
|
|
{
|
|
char errmsg[STRERR_BUFSIZE];
|
|
struct bpf_link *link;
|
|
int prog_fd, pfd;
|
|
|
|
prog_fd = bpf_program__fd(prog);
|
|
if (prog_fd < 0) {
|
|
pr_warn("program '%s': can't attach before loaded\n",
|
|
bpf_program__title(prog, false));
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link)
|
|
return ERR_PTR(-ENOMEM);
|
|
link->detach = &bpf_link__detach_fd;
|
|
|
|
pfd = bpf_raw_tracepoint_open(NULL, prog_fd);
|
|
if (pfd < 0) {
|
|
pfd = -errno;
|
|
free(link);
|
|
pr_warn("program '%s': failed to attach: %s\n",
|
|
bpf_program__title(prog, false),
|
|
libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
|
|
return ERR_PTR(pfd);
|
|
}
|
|
link->fd = pfd;
|
|
return (struct bpf_link *)link;
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_trace(struct bpf_program *prog)
|
|
{
|
|
return bpf_program__attach_btf_id(prog);
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach_lsm(struct bpf_program *prog)
|
|
{
|
|
return bpf_program__attach_btf_id(prog);
|
|
}
|
|
|
|
static struct bpf_link *attach_trace(const struct bpf_sec_def *sec,
|
|
struct bpf_program *prog)
|
|
{
|
|
return bpf_program__attach_trace(prog);
|
|
}
|
|
|
|
static struct bpf_link *attach_lsm(const struct bpf_sec_def *sec,
|
|
struct bpf_program *prog)
|
|
{
|
|
return bpf_program__attach_lsm(prog);
|
|
}
|
|
|
|
static struct bpf_link *attach_iter(const struct bpf_sec_def *sec,
|
|
struct bpf_program *prog)
|
|
{
|
|
return bpf_program__attach_iter(prog, NULL);
|
|
}
|
|
|
|
static struct bpf_link *
|
|
bpf_program__attach_fd(struct bpf_program *prog, int target_fd,
|
|
const char *target_name)
|
|
{
|
|
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("program '%s': can't attach before loaded\n",
|
|
bpf_program__title(prog, false));
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link)
|
|
return ERR_PTR(-ENOMEM);
|
|
link->detach = &bpf_link__detach_fd;
|
|
|
|
attach_type = bpf_program__get_expected_attach_type(prog);
|
|
link_fd = bpf_link_create(prog_fd, target_fd, attach_type, NULL);
|
|
if (link_fd < 0) {
|
|
link_fd = -errno;
|
|
free(link);
|
|
pr_warn("program '%s': failed to attach to %s: %s\n",
|
|
bpf_program__title(prog, false), target_name,
|
|
libbpf_strerror_r(link_fd, errmsg, sizeof(errmsg)));
|
|
return ERR_PTR(link_fd);
|
|
}
|
|
link->fd = link_fd;
|
|
return link;
|
|
}
|
|
|
|
struct bpf_link *
|
|
bpf_program__attach_cgroup(struct bpf_program *prog, int cgroup_fd)
|
|
{
|
|
return bpf_program__attach_fd(prog, cgroup_fd, "cgroup");
|
|
}
|
|
|
|
struct bpf_link *
|
|
bpf_program__attach_netns(struct bpf_program *prog, int netns_fd)
|
|
{
|
|
return bpf_program__attach_fd(prog, netns_fd, "netns");
|
|
}
|
|
|
|
struct bpf_link *
|
|
bpf_program__attach_iter(struct bpf_program *prog,
|
|
const struct bpf_iter_attach_opts *opts)
|
|
{
|
|
char errmsg[STRERR_BUFSIZE];
|
|
struct bpf_link *link;
|
|
int prog_fd, link_fd;
|
|
|
|
if (!OPTS_VALID(opts, bpf_iter_attach_opts))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
prog_fd = bpf_program__fd(prog);
|
|
if (prog_fd < 0) {
|
|
pr_warn("program '%s': can't attach before loaded\n",
|
|
bpf_program__title(prog, false));
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link)
|
|
return ERR_PTR(-ENOMEM);
|
|
link->detach = &bpf_link__detach_fd;
|
|
|
|
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_ITER, NULL);
|
|
if (link_fd < 0) {
|
|
link_fd = -errno;
|
|
free(link);
|
|
pr_warn("program '%s': failed to attach to iterator: %s\n",
|
|
bpf_program__title(prog, false),
|
|
libbpf_strerror_r(link_fd, errmsg, sizeof(errmsg)));
|
|
return ERR_PTR(link_fd);
|
|
}
|
|
link->fd = link_fd;
|
|
return link;
|
|
}
|
|
|
|
struct bpf_link *bpf_program__attach(struct bpf_program *prog)
|
|
{
|
|
const struct bpf_sec_def *sec_def;
|
|
|
|
sec_def = find_sec_def(bpf_program__title(prog, false));
|
|
if (!sec_def || !sec_def->attach_fn)
|
|
return ERR_PTR(-ESRCH);
|
|
|
|
return sec_def->attach_fn(sec_def, prog);
|
|
}
|
|
|
|
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(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 ERR_PTR(-EINVAL);
|
|
|
|
link = calloc(1, sizeof(*link));
|
|
if (!link)
|
|
return 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 ERR_PTR(err);
|
|
}
|
|
|
|
link->detach = bpf_link__detach_struct_ops;
|
|
link->fd = map->fd;
|
|
|
|
return link;
|
|
}
|
|
|
|
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_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 ret;
|
|
}
|
|
|
|
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 (!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);
|
|
|
|
struct perf_buffer *perf_buffer__new(int map_fd, size_t page_cnt,
|
|
const struct perf_buffer_opts *opts)
|
|
{
|
|
struct perf_buffer_params p = {};
|
|
struct perf_event_attr attr = { 0, };
|
|
|
|
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 = opts ? opts->sample_cb : NULL;
|
|
p.lost_cb = opts ? opts->lost_cb : NULL;
|
|
p.ctx = opts ? opts->ctx : NULL;
|
|
|
|
return __perf_buffer__new(map_fd, page_cnt, &p);
|
|
}
|
|
|
|
struct perf_buffer *
|
|
perf_buffer__new_raw(int map_fd, size_t page_cnt,
|
|
const struct perf_buffer_raw_opts *opts)
|
|
{
|
|
struct perf_buffer_params p = {};
|
|
|
|
p.attr = opts->attr;
|
|
p.event_cb = opts->event_cb;
|
|
p.ctx = opts->ctx;
|
|
p.cpu_cnt = opts->cpu_cnt;
|
|
p.cpus = opts->cpus;
|
|
p.map_keys = opts->map_keys;
|
|
|
|
return __perf_buffer__new(map_fd, page_cnt, &p);
|
|
}
|
|
|
|
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 & (page_cnt - 1)) {
|
|
pr_warn("page count should be power of two, but is %zu\n",
|
|
page_cnt);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
map_info_len = sizeof(map);
|
|
err = bpf_obj_get_info_by_fd(map_fd, &map, &map_info_len);
|
|
if (err) {
|
|
err = -errno;
|
|
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);
|
|
}
|
|
|
|
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 < 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 = bpf_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__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);
|
|
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 err;
|
|
}
|
|
}
|
|
return cnt < 0 ? -errno : cnt;
|
|
}
|
|
|
|
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("error while processing records: %d\n", err);
|
|
return 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 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 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 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 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_id;
|
|
|
|
if (!prog || attach_prog_fd < 0 || !attach_func_name)
|
|
return -EINVAL;
|
|
|
|
if (attach_prog_fd)
|
|
btf_id = libbpf_find_prog_btf_id(attach_func_name,
|
|
attach_prog_fd);
|
|
else
|
|
btf_id = __find_vmlinux_btf_id(prog->obj->btf_vmlinux,
|
|
attach_func_name,
|
|
prog->expected_attach_type);
|
|
|
|
if (btf_id < 0)
|
|
return btf_id;
|
|
|
|
prog->attach_btf_id = btf_id;
|
|
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);
|
|
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 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;
|
|
}
|
|
|
|
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 i;
|
|
|
|
/* 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);
|
|
if (IS_ERR(obj)) {
|
|
pr_warn("failed to initialize skeleton BPF object '%s': %ld\n",
|
|
s->name, PTR_ERR(obj));
|
|
return PTR_ERR(obj);
|
|
}
|
|
|
|
*s->obj = obj;
|
|
|
|
for (i = 0; i < s->map_cnt; i++) {
|
|
struct bpf_map **map = s->maps[i].map;
|
|
const char *name = s->maps[i].name;
|
|
void **mmaped = s->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;
|
|
}
|
|
|
|
for (i = 0; i < s->prog_cnt; i++) {
|
|
struct bpf_program **prog = s->progs[i].prog;
|
|
const char *name = s->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__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 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 err;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < s->prog_cnt; i++) {
|
|
struct bpf_program *prog = *s->progs[i].prog;
|
|
struct bpf_link **link = s->progs[i].link;
|
|
const struct bpf_sec_def *sec_def;
|
|
const char *sec_name = bpf_program__title(prog, false);
|
|
|
|
sec_def = find_sec_def(sec_name);
|
|
if (!sec_def || !sec_def->attach_fn)
|
|
continue;
|
|
|
|
*link = sec_def->attach_fn(sec_def, prog);
|
|
if (IS_ERR(*link)) {
|
|
pr_warn("failed to auto-attach program '%s': %ld\n",
|
|
bpf_program__name(prog), PTR_ERR(*link));
|
|
return PTR_ERR(*link);
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
if (!IS_ERR_OR_NULL(*link))
|
|
bpf_link__destroy(*link);
|
|
*link = NULL;
|
|
}
|
|
}
|
|
|
|
void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s)
|
|
{
|
|
if (s->progs)
|
|
bpf_object__detach_skeleton(s);
|
|
if (s->obj)
|
|
bpf_object__close(*s->obj);
|
|
free(s->maps);
|
|
free(s->progs);
|
|
free(s);
|
|
}
|