From b6e2d1e253a4134eb2985453ccae78c1115e67db Mon Sep 17 00:00:00 2001
From: Markus Elfring <Markus.Elfring@web.de>
Date: Thu, 13 Apr 2023 14:46:39 +0200
Subject: [PATCH] perf map: Delete two variable initialisations before null
pointer checks in sort__sym_from_cmp()
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[ Upstream commit c160118a90d4acf335993d8d59b02ae2147a524e ]
Addresses of two data structure members were determined before
corresponding null pointer checks in the implementation of the function
“sort__sym_from_cmp”.
Thus avoid the risk for undefined behaviour by removing extra
initialisations for the local variables “from_l” and “from_r” (also
because they were already reassigned with the same value behind this
pointer check).
This issue was detected by using the Coccinelle software.
Fixes: 1b9e97a2a95e4941 ("perf tools: Fix report -F symbol_from for data without branch info")
Signed-off-by: <elfring@users.sourceforge.net>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/cocci/54a21fea-64e3-de67-82ef-d61b90ffad05@web.de/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/util/sort.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index a111065b484e..a4f2ffe2bdb6 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -876,8 +876,7 @@ static int hist_entry__dso_to_filter(struct hist_entry *he, int type,
static int64_t
sort__sym_from_cmp(struct hist_entry *left, struct hist_entry *right)
{
- struct addr_map_symbol *from_l = &left->branch_info->from;
- struct addr_map_symbol *from_r = &right->branch_info->from;
+ struct addr_map_symbol *from_l, *from_r;
if (!left->branch_info || !right->branch_info)
return cmp_null(left->branch_info, right->branch_info);