From: Andrey Ignatov <rdna@fb.com>
Date: Fri, 19 Jun 2020 14:11:41 -0700
Subject: bpf: Switch btf_parse_vmlinux to btf_find_by_name_kind
Patch-mainline: v5.9-rc1
Git-commit: a2d0d62f4d9e3546134ba08e102ca7decd4ed836
References: bsc#1177028
btf_parse_vmlinux() implements manual search for struct bpf_ctx_convert
since at the time of implementing btf_find_by_name_kind() was not
available.
Later btf_find_by_name_kind() was introduced in 27ae7997a661 ("bpf:
Introduce BPF_PROG_TYPE_STRUCT_OPS"). It provides similar search
functionality and can be leveraged in btf_parse_vmlinux(). Do it.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/6e12d5c3e8a3d552925913ef73a695dd1bb27800.1592600985.git.rdna@fb.com
Acked-by: Gary Lin <glin@suse.com>
---
kernel/bpf/btf.c | 23 ++++++-----------------
1 file changed, 6 insertions(+), 17 deletions(-)
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3591,7 +3591,7 @@ struct btf *btf_parse_vmlinux(void)
struct btf_verifier_env *env = NULL;
struct bpf_verifier_log *log;
struct btf *btf = NULL;
- int err, i;
+ int err, btf_id;
env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
if (!env)
@@ -3626,24 +3626,13 @@ struct btf *btf_parse_vmlinux(void)
goto errout;
/* find struct bpf_ctx_convert for type checking later */
- for (i = 1; i <= btf->nr_types; i++) {
- const struct btf_type *t;
- const char *tname;
-
- t = btf_type_by_id(btf, i);
- if (!__btf_type_is_struct(t))
- continue;
- tname = __btf_name_by_offset(btf, t->name_off);
- if (!strcmp(tname, "bpf_ctx_convert")) {
- /* btf_parse_vmlinux() runs under bpf_verifier_lock */
- bpf_ctx_convert.t = t;
- break;
- }
- }
- if (i > btf->nr_types) {
- err = -ENOENT;
+ btf_id = btf_find_by_name_kind(btf, "bpf_ctx_convert", BTF_KIND_STRUCT);
+ if (btf_id < 0) {
+ err = btf_id;
goto errout;
}
+ /* btf_parse_vmlinux() runs under bpf_verifier_lock */
+ bpf_ctx_convert.t = btf_type_by_id(btf, btf_id);
bpf_struct_ops_init(btf, log);