From 9704669c386f9bbfef2e002e7e690c56b7dcf5de Mon Sep 17 00:00:00 2001 From: "Masami Hiramatsu (Google)" Date: Sat, 17 Feb 2024 21:25:42 +0900 Subject: [PATCH] tracing/probes: Fix to search structure fields correctly Fix to search a field from the structure which has anonymous union correctly. Since the reference `type` pointer was updated in the loop, the search loop suddenly aborted where it hits an anonymous union. Thus it can not find the field after the anonymous union. This avoids updating the cursor `type` pointer in the loop. Link: https://lore.kernel.org/all/170791694361.389532.10047514554799419688.stgit@devnote2/ Fixes: 302db0f5b3d8 ("tracing/probes: Add a function to search a member of a struct/union") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_btf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_btf.c b/kernel/trace/trace_btf.c index ca224d53bfdc..5bbdbcbbde3c 100644 --- a/kernel/trace/trace_btf.c +++ b/kernel/trace/trace_btf.c @@ -91,8 +91,8 @@ retry: for_each_member(i, type, member) { if (!member->name_off) { /* Anonymous union/struct: push it for later use */ - type = btf_type_skip_modifiers(btf, member->type, &tid); - if (type && top < BTF_ANON_STACK_MAX) { + if (btf_type_skip_modifiers(btf, member->type, &tid) && + top < BTF_ANON_STACK_MAX) { anon_stack[top].tid = tid; anon_stack[top++].offset = cur_offset + member->offset;