From: Ian Rogers <irogers@google.com>
Date: Thu, 14 Sep 2023 04:42:32 +0000 (-0700)
Subject: perf symbol: Avoid an undefined behavior warning
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=21ce931e55c19c1f74378b4836d9dae631da0e62;p=linux.git

perf symbol: Avoid an undefined behavior warning

The node (nd) may be NULL and pointer arithmetic on NULL is undefined
behavior. Move the computation of next below the NULL check on the
node.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20230914044233.1550195-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 3f36675b7c8ff..5b54d2639df47 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -202,11 +202,10 @@ void symbols__fixup_duplicate(struct rb_root_cached *symbols)
 		curr = rb_entry(nd, struct symbol, rb_node);
 again:
 		nd = rb_next(&curr->rb_node);
-		next = rb_entry(nd, struct symbol, rb_node);
-
 		if (!nd)
 			break;
 
+		next = rb_entry(nd, struct symbol, rb_node);
 		if (curr->start != next->start)
 			continue;