linuxdebug/kernel/bpf/preload/iterators/iterators.bpf.c

114 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_core_read.h>
#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)
struct seq_file;
struct bpf_iter_meta {
struct seq_file *seq;
__u64 session_id;
__u64 seq_num;
};
struct bpf_map {
__u32 id;
char name[16];
__u32 max_entries;
};
struct bpf_iter__bpf_map {
struct bpf_iter_meta *meta;
struct bpf_map *map;
};
struct btf_type {
__u32 name_off;
};
struct btf_header {
__u32 str_len;
};
struct btf {
const char *strings;
struct btf_type **types;
struct btf_header hdr;
};
struct bpf_prog_aux {
__u32 id;
char name[16];
const char *attach_func_name;
struct bpf_prog *dst_prog;
struct bpf_func_info *func_info;
struct btf *btf;
};
struct bpf_prog {
struct bpf_prog_aux *aux;
};
struct bpf_iter__bpf_prog {
struct bpf_iter_meta *meta;
struct bpf_prog *prog;
};
#pragma clang attribute pop
static const char *get_name(struct btf *btf, long btf_id, const char *fallback)
{
struct btf_type **types, *t;
unsigned int name_off;
const char *str;
if (!btf)
return fallback;
str = btf->strings;
types = btf->types;
bpf_probe_read_kernel(&t, sizeof(t), types + btf_id);
name_off = BPF_CORE_READ(t, name_off);
if (name_off >= btf->hdr.str_len)
return fallback;
return str + name_off;
}
SEC("iter/bpf_map")
int dump_bpf_map(struct bpf_iter__bpf_map *ctx)
{
struct seq_file *seq = ctx->meta->seq;
__u64 seq_num = ctx->meta->seq_num;
struct bpf_map *map = ctx->map;
if (!map)
return 0;
if (seq_num == 0)
BPF_SEQ_PRINTF(seq, " id name max_entries\n");
BPF_SEQ_PRINTF(seq, "%4u %-16s%6d\n", map->id, map->name, map->max_entries);
return 0;
}
SEC("iter/bpf_prog")
int dump_bpf_prog(struct bpf_iter__bpf_prog *ctx)
{
struct seq_file *seq = ctx->meta->seq;
__u64 seq_num = ctx->meta->seq_num;
struct bpf_prog *prog = ctx->prog;
struct bpf_prog_aux *aux;
if (!prog)
return 0;
aux = prog->aux;
if (seq_num == 0)
BPF_SEQ_PRINTF(seq, " id name attached\n");
BPF_SEQ_PRINTF(seq, "%4u %-16s %s %s\n", aux->id,
get_name(aux->btf, aux->func_info[0].type_id, aux->name),
aux->attach_func_name, aux->dst_prog->aux->name);
return 0;
}
char LICENSE[] SEC("license") = "GPL";