linux/kernel/bpf/map_iter.c

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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2020 Facebook */
#include <linux/bpf.h>
#include <linux/fs.h>
#include <linux/filter.h>
#include <linux/kernel.h>
#include <linux/btf_ids.h>
struct bpf_iter_seq_map_info {
u32 mid;
};
static void *bpf_map_seq_start(struct seq_file *seq, loff_t *pos)
{
struct bpf_iter_seq_map_info *info = seq->private;
struct bpf_map *map;
map = bpf_map_get_curr_or_next(&info->mid);
if (!map)
return NULL;
++*pos;
return map;
}
static void *bpf_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct bpf_iter_seq_map_info *info = seq->private;
struct bpf_map *map;
++*pos;
++info->mid;
bpf_map_put((struct bpf_map *)v);
map = bpf_map_get_curr_or_next(&info->mid);
if (!map)
return NULL;
return map;
}
struct bpf_iter__bpf_map {
__bpf_md_ptr(struct bpf_iter_meta *, meta);
__bpf_md_ptr(struct bpf_map *, map);
};
DEFINE_BPF_ITER_FUNC(bpf_map, struct bpf_iter_meta *meta, struct bpf_map *map)
static int __bpf_map_seq_show(struct seq_file *seq, void *v, bool in_stop)
{
struct bpf_iter__bpf_map ctx;
struct bpf_iter_meta meta;
struct bpf_prog *prog;
int ret = 0;
ctx.meta = &meta;
ctx.map = v;
meta.seq = seq;
prog = bpf_iter_get_info(&meta, in_stop);
if (prog)
ret = bpf_iter_run_prog(prog, &ctx);
return ret;
}
static int bpf_map_seq_show(struct seq_file *seq, void *v)
{
return __bpf_map_seq_show(seq, v, false);
}
static void bpf_map_seq_stop(struct seq_file *seq, void *v)
{
if (!v)
(void)__bpf_map_seq_show(seq, v, true);
else
bpf_map_put((struct bpf_map *)v);
}
static const struct seq_operations bpf_map_seq_ops = {
.start = bpf_map_seq_start,
.next = bpf_map_seq_next,
.stop = bpf_map_seq_stop,
.show = bpf_map_seq_show,
};
BTF_ID_LIST(btf_bpf_map_id)
BTF_ID(struct, bpf_map)
static struct bpf_iter_reg bpf_map_reg_info = {
.target = "bpf_map",
.seq_ops = &bpf_map_seq_ops,
.init_seq_private = NULL,
.fini_seq_private = NULL,
.seq_priv_size = sizeof(struct bpf_iter_seq_map_info),
.ctx_arg_info_size = 1,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__bpf_map, map),
PTR_TO_BTF_ID_OR_NULL },
},
};
static int __init bpf_map_iter_init(void)
{
bpf_map_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_map_id;
return bpf_iter_reg_target(&bpf_map_reg_info);
}
late_initcall(bpf_map_iter_init);