mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-31 16:38:12 +00:00
2341d6bb13
Improve selftest to check that btf_load is working from bpf program. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210514003623.28033-8-alexei.starovoitov@gmail.com
121 lines
3.1 KiB
C
121 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/* Copyright (c) 2021 Facebook */
|
|
#include <linux/stddef.h>
|
|
#include <linux/bpf.h>
|
|
#include <bpf/bpf_helpers.h>
|
|
#include <bpf/bpf_tracing.h>
|
|
#include <../../../tools/include/linux/filter.h>
|
|
#include <linux/btf.h>
|
|
|
|
char _license[] SEC("license") = "GPL";
|
|
|
|
struct args {
|
|
__u64 log_buf;
|
|
__u32 log_size;
|
|
int max_entries;
|
|
int map_fd;
|
|
int prog_fd;
|
|
int btf_fd;
|
|
};
|
|
|
|
#define BTF_INFO_ENC(kind, kind_flag, vlen) \
|
|
((!!(kind_flag) << 31) | ((kind) << 24) | ((vlen) & BTF_MAX_VLEN))
|
|
#define BTF_TYPE_ENC(name, info, size_or_type) (name), (info), (size_or_type)
|
|
#define BTF_INT_ENC(encoding, bits_offset, nr_bits) \
|
|
((encoding) << 24 | (bits_offset) << 16 | (nr_bits))
|
|
#define BTF_TYPE_INT_ENC(name, encoding, bits_offset, bits, sz) \
|
|
BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_INT, 0, 0), sz), \
|
|
BTF_INT_ENC(encoding, bits_offset, bits)
|
|
|
|
static int btf_load(void)
|
|
{
|
|
struct btf_blob {
|
|
struct btf_header btf_hdr;
|
|
__u32 types[8];
|
|
__u32 str;
|
|
} raw_btf = {
|
|
.btf_hdr = {
|
|
.magic = BTF_MAGIC,
|
|
.version = BTF_VERSION,
|
|
.hdr_len = sizeof(struct btf_header),
|
|
.type_len = sizeof(__u32) * 8,
|
|
.str_off = sizeof(__u32) * 8,
|
|
.str_len = sizeof(__u32),
|
|
},
|
|
.types = {
|
|
/* long */
|
|
BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 64, 8), /* [1] */
|
|
/* unsigned long */
|
|
BTF_TYPE_INT_ENC(0, 0, 0, 64, 8), /* [2] */
|
|
},
|
|
};
|
|
static union bpf_attr btf_load_attr = {
|
|
.btf_size = sizeof(raw_btf),
|
|
};
|
|
|
|
btf_load_attr.btf = (long)&raw_btf;
|
|
return bpf_sys_bpf(BPF_BTF_LOAD, &btf_load_attr, sizeof(btf_load_attr));
|
|
}
|
|
|
|
SEC("syscall")
|
|
int bpf_prog(struct args *ctx)
|
|
{
|
|
static char license[] = "GPL";
|
|
static struct bpf_insn insns[] = {
|
|
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
|
|
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
|
|
BPF_LD_MAP_FD(BPF_REG_1, 0),
|
|
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
BPF_EXIT_INSN(),
|
|
};
|
|
static union bpf_attr map_create_attr = {
|
|
.map_type = BPF_MAP_TYPE_HASH,
|
|
.key_size = 8,
|
|
.value_size = 8,
|
|
.btf_key_type_id = 1,
|
|
.btf_value_type_id = 2,
|
|
};
|
|
static union bpf_attr map_update_attr = { .map_fd = 1, };
|
|
static __u64 key = 12;
|
|
static __u64 value = 34;
|
|
static union bpf_attr prog_load_attr = {
|
|
.prog_type = BPF_PROG_TYPE_XDP,
|
|
.insn_cnt = sizeof(insns) / sizeof(insns[0]),
|
|
};
|
|
int ret;
|
|
|
|
ret = btf_load();
|
|
if (ret <= 0)
|
|
return ret;
|
|
|
|
ctx->btf_fd = ret;
|
|
map_create_attr.max_entries = ctx->max_entries;
|
|
map_create_attr.btf_fd = ret;
|
|
|
|
prog_load_attr.license = (long) license;
|
|
prog_load_attr.insns = (long) insns;
|
|
prog_load_attr.log_buf = ctx->log_buf;
|
|
prog_load_attr.log_size = ctx->log_size;
|
|
prog_load_attr.log_level = 1;
|
|
|
|
ret = bpf_sys_bpf(BPF_MAP_CREATE, &map_create_attr, sizeof(map_create_attr));
|
|
if (ret <= 0)
|
|
return ret;
|
|
ctx->map_fd = ret;
|
|
insns[3].imm = ret;
|
|
|
|
map_update_attr.map_fd = ret;
|
|
map_update_attr.key = (long) &key;
|
|
map_update_attr.value = (long) &value;
|
|
ret = bpf_sys_bpf(BPF_MAP_UPDATE_ELEM, &map_update_attr, sizeof(map_update_attr));
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = bpf_sys_bpf(BPF_PROG_LOAD, &prog_load_attr, sizeof(prog_load_attr));
|
|
if (ret <= 0)
|
|
return ret;
|
|
ctx->prog_fd = ret;
|
|
return 1;
|
|
}
|