From: Ian Rogers <irogers@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
Ian Rogers <irogers@google.com>,
Adrian Hunter <adrian.hunter@intel.com>,
James Clark <james.clark@arm.com>,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v1] perf symbol: Avoid an undefined behavior warning
Date: Wed, 13 Sep 2023 21:42:32 -0700 [thread overview]
Message-ID: <20230914044233.1550195-1-irogers@google.com> (raw)
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>
---
tools/perf/util/symbol.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 3f36675b7c8f..5b54d2639df4 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;
--
2.42.0.459.ge4e396fd5e-goog
next reply other threads:[~2023-09-14 4:42 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-14 4:42 Ian Rogers [this message]
2023-09-17 5:29 ` [PATCH v1] perf symbol: Avoid an undefined behavior warning Namhyung Kim
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