github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-14 16:10:02 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

bpf: Rename 'early' BTF checking as a preparation phase

Browse Source 
BTF processing is split around subprogram discovery. The first phase gets
program BTF and imports func_info because a BTF-tagged exception callback
may not be referenced by any instruction. Subprogram discovery needs this
metadata to find it.

The later phase validates func_info and line_info against the complete
subprogram table and applies CO-RE relocations. This split breaks a real
dependency cycle rather than merely running the same checks early.

Rename bpf_check_btf_info_early() and check_btf_func_early() to preparation
names that reflect this role. Add short call-site comments to make the two
phases and their responsibilities clear.

No functional change is intended.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Reviewed-by: Amery Hung <ameryhung@gmail.com>
Link: https://patch.msgid.link/20260808003938.3486067-2-memxor@gmail.com
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
This commit is contained in:
Kumar Kartikeya Dwivedi 2026-08-08 02:39:21 +02:00 committed by Eduard Zingerman
parent 8b365b3c68
commit 04962afb3c
3 changed files with 12 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
include/linux/bpf_verifier.h
View File

@ -1172,8 +1172,8 @@ static inline void bpf_trampoline_unpack_key(u64 key, u32 *obj_id, u32 *btf_id)
*btf_id = key & 0x7FFFFFFF;
}
int bpf_check_btf_info_early(struct bpf_verifier_env *env,
const union bpf_attr *attr, bpfptr_t uattr);
int bpf_prepare_btf_info(struct bpf_verifier_env *env,
const union bpf_attr *attr, bpfptr_t uattr);
int bpf_check_btf_info(struct bpf_verifier_env *env,
const union bpf_attr *attr, bpfptr_t uattr);

14
kernel/bpf/check_btf.c
View File

@ -28,9 +28,9 @@ static int check_abnormal_return(struct bpf_verifier_env *env)
#define MIN_BPF_FUNCINFO_SIZE 8
#define MAX_FUNCINFO_REC_SIZE 252
static int check_btf_func_early(struct bpf_verifier_env *env,
const union bpf_attr *attr,
bpfptr_t uattr)
static int prepare_btf_func(struct bpf_verifier_env *env,
const union bpf_attr *attr,
bpfptr_t uattr)
{
u32 krec_size = sizeof(struct bpf_func_info);
const struct btf_type *type, *func_proto;
@ -407,9 +407,9 @@ static int check_core_relo(struct bpf_verifier_env *env,
return err;
}
int bpf_check_btf_info_early(struct bpf_verifier_env *env,
const union bpf_attr *attr,
bpfptr_t uattr)
int bpf_prepare_btf_info(struct bpf_verifier_env *env,
const union bpf_attr *attr,
bpfptr_t uattr)
{
struct btf *btf;
int err;
@ -429,7 +429,7 @@ int bpf_check_btf_info_early(struct bpf_verifier_env *env,
}
env->prog->aux->btf = btf;
err = check_btf_func_early(env, attr, uattr);
err = prepare_btf_func(env, attr, uattr);
if (err)
return err;
return 0;

4
kernel/bpf/verifier.c
View File

@ -20135,7 +20135,8 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr,
INIT_LIST_HEAD(&env->explored_states[i]);
INIT_LIST_HEAD(&env->free_list);
ret = bpf_check_btf_info_early(env, attr, uattr);
/* Prepare BTF and func_info needed to discover all subprograms. */
ret = bpf_prepare_btf_info(env, attr, uattr);
if (ret < 0)
goto skip_full_check;
@ -20147,6 +20148,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr,
if (ret < 0)
goto skip_full_check;
/* Validate BTF against the complete subprogram layout and apply CO-RE. */
ret = bpf_check_btf_info(env, attr, uattr);
if (ret < 0)
goto skip_full_check;