mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-26 10:15:13 +07:00
3c32cc1bce
Commit b121b341e5 ("bpf: Add PTR_TO_BTF_ID_OR_NULL
support") adds a field btf_id_or_null_non0_off to
bpf_prog->aux structure to indicate that the
first ctx argument is PTR_TO_BTF_ID reg_type and
all others are PTR_TO_BTF_ID_OR_NULL.
This approach does not really scale if we have
other different reg types in the future, e.g.,
a pointer to a buffer.
This patch enables bpf_iter targets registering ctx argument
reg types which may be different from the default one.
For example, for pointers to structures, the default reg_type
is PTR_TO_BTF_ID for tracing program. The target can register
a particular pointer type as PTR_TO_BTF_ID_OR_NULL which can
be used by the verifier to enforce accesses.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200513180221.2949882-1-yhs@fb.com
103 lines
2.1 KiB
C
103 lines
2.1 KiB
C
// 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>
|
|
|
|
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,
|
|
};
|
|
|
|
static const 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)
|
|
{
|
|
return bpf_iter_reg_target(&bpf_map_reg_info);
|
|
}
|
|
|
|
late_initcall(bpf_map_iter_init);
|