From: Ian Rogers <irogers@google.com>
Date: Thu, 12 Mar 2026 22:31:31 +0000 (-0700)
Subject: perf branch: Avoid incrementing NULL
X-Git-Tag: v7.1-rc1~91^2~108
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=c969a9d7bbf46f983c4a48566b3b2f7340b02296;p=thirdparty%2Fkernel%2Flinux.git

perf branch: Avoid incrementing NULL

If the entry is NULL the value is meaningless so early return NULL to
avoid an increment of NULL. This was happening in calls from
has_stitched_lbr when running the "perf record LBR tests". The return
value isn't used in that case, so returning NULL as no effect.

Fixes: 42bbabed09ce ("perf tools: Add hw_idx in struct branch_stack")
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---

diff --git a/tools/perf/util/branch.h b/tools/perf/util/branch.h
index 7429530fa7749..a1d4736497c40 100644
--- a/tools/perf/util/branch.h
+++ b/tools/perf/util/branch.h
@@ -66,6 +66,9 @@ static inline struct branch_entry *perf_sample__branch_entries(struct perf_sampl
 {
 	u64 *entry = (u64 *)sample->branch_stack;
 
+	if (entry == NULL)
+		return NULL;
+
 	entry++;
 	if (sample->no_hw_idx)
 		return (struct branch_entry *)entry;