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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/kernel/bpf/preload/iterators/iterators.bpf.c
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// SPDX-License-Identifier: GPL-2.0

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/* Copyright (c) 2020 Facebook */

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#include <linux/bpf.h>

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#include <bpf/bpf_helpers.h>

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#include <bpf/bpf_core_read.h>

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#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)

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struct seq_file;

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struct bpf_iter_meta {

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	struct seq_file *seq;

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	__u64 session_id;

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	__u64 seq_num;

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};

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struct bpf_map {

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	__u32 id;

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	char name[16];

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	__u32 max_entries;

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};

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struct bpf_iter__bpf_map {

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	struct bpf_iter_meta *meta;

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	struct bpf_map *map;

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};

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struct btf_type {

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	__u32 name_off;

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};

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struct btf_header {

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	__u32   str_len;

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};

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struct btf {

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	const char *strings;

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	struct btf_type **types;

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	struct btf_header hdr;

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};

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struct bpf_prog_aux {

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	__u32 id;

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	char name[16];

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	const char *attach_func_name;

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	struct bpf_prog *dst_prog;

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	struct bpf_func_info *func_info;

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	struct btf *btf;

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};

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struct bpf_prog {

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	struct bpf_prog_aux *aux;

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};

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struct bpf_iter__bpf_prog {

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	struct bpf_iter_meta *meta;

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	struct bpf_prog *prog;

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};

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#pragma clang attribute pop

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static const char *get_name(struct btf *btf, long btf_id, const char *fallback)

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{

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	struct btf_type **types, *t;

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	unsigned int name_off;

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	const char *str;

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	if (!btf)

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		return fallback;

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	str = btf->strings;

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	types = btf->types;

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	bpf_probe_read_kernel(&t, sizeof(t), types + btf_id);

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	name_off = BPF_CORE_READ(t, name_off);

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	if (name_off >= btf->hdr.str_len)

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		return fallback;

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	return str + name_off;

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}

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__s64 bpf_map_sum_elem_count(struct bpf_map *map) __ksym;

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SEC("iter/bpf_map")

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int dump_bpf_map(struct bpf_iter__bpf_map *ctx)

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{

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	struct seq_file *seq = ctx->meta->seq;

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	__u64 seq_num = ctx->meta->seq_num;

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	struct bpf_map *map = ctx->map;

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	if (!map)

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		return 0;

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	if (seq_num == 0)

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		BPF_SEQ_PRINTF(seq, "  id name             max_entries  cur_entries\n");

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	BPF_SEQ_PRINTF(seq, "%4u %-16s  %10d   %10lld\n",

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		       map->id, map->name, map->max_entries,

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		       bpf_map_sum_elem_count(map));

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	return 0;

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}

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SEC("iter/bpf_prog")

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int dump_bpf_prog(struct bpf_iter__bpf_prog *ctx)

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{

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	struct seq_file *seq = ctx->meta->seq;

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	__u64 seq_num = ctx->meta->seq_num;

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	struct bpf_prog *prog = ctx->prog;

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	struct bpf_prog_aux *aux;

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	if (!prog)

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		return 0;

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	aux = prog->aux;

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	if (seq_num == 0)

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		BPF_SEQ_PRINTF(seq, "  id name             attached\n");

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	BPF_SEQ_PRINTF(seq, "%4u %-16s %s %s\n", aux->id,

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		       get_name(aux->btf, aux->func_info[0].type_id, aux->name),

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		       aux->attach_func_name, aux->dst_prog->aux->name);

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	return 0;

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}

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char LICENSE[] SEC("license") = "GPL";

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