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| author | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2026-09-01 23:21:37 +0900 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2026-09-03 09:04:25 +0900 |
| commit | f36d94a20ca185bcadef3a10b980cd2cfd72d53a (patch) | |
| tree | b872e15c33951162f3d458e20a6d5b989eef04ff | |
| parent | 738ef4cd82818b13f492fd5ddec7e00f177ffe60 (diff) | |
| download | linux-next-f36d94a20ca185bcadef3a10b980cd2cfd72d53a.tar.gz linux-next-f36d94a20ca185bcadef3a10b980cd2cfd72d53a.zip | |
tracing/probes: Fix anon_stack check for unnamed bitfields in btf_find_struct_member
btf_find_struct_member() traverses into nested anonymous structures
and unions by pushing members with !member->name_off onto anon_stack.
However, it does not consider the unnamed bitfields (e.g. `int : 5`
or `unsigned int : 0`) which also have member->name_off == 0.
If such an unnamed bitfield is pushed to anon_stack, the
btf_find_struct_member() return an error even if there are other
valid entries in anon_stack.
To fix this, only push unnamed struct/union members to anon_stack.
Also move the btf_type_is_struct() check to the entry of this function
because now it is sure only struct/union are pushed to anon_stack.
Link: https://lore.kernel.org/all/178827249775.123716.7813217688423513612.stgit@devnote2/
Fixes: 302db0f5b3d8 ("tracing/probes: Add a function to search a member of a struct/union")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260830143859.D56991F00A3D@smtp.kernel.org/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/trace_btf.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/trace/trace_btf.c b/kernel/trace/trace_btf.c index 00172f301f25..d3ba356d5503 100644 --- a/kernel/trace/trace_btf.c +++ b/kernel/trace/trace_btf.c @@ -74,24 +74,24 @@ const struct btf_member *btf_find_struct_member(struct btf *btf, { struct btf_anon_stack *anon_stack; const struct btf_member *member; + const struct btf_type *mtype; u32 tid, cur_offset = 0; const char *name; int i, top = 0; + if (!btf_type_is_struct(type)) + return ERR_PTR(-EINVAL); + anon_stack = kzalloc_objs(*anon_stack, BTF_ANON_STACK_MAX); if (!anon_stack) return ERR_PTR(-ENOMEM); retry: - if (!btf_type_is_struct(type)) { - member = ERR_PTR(-EINVAL); - goto out; - } - for_each_member(i, type, member) { if (!member->name_off) { /* Anonymous union/struct: push it for later use */ - if (btf_type_skip_modifiers(btf, member->type, &tid) && + mtype = btf_type_skip_modifiers(btf, member->type, &tid); + if (mtype && btf_type_is_struct(mtype) && top < BTF_ANON_STACK_MAX) { anon_stack[top].tid = tid; anon_stack[top++].offset = |