[cocci] [PATCH] perf map: Delete two variable initialisations before null pointer checks in sort__sym_from_cmp()

[Markus Elfring <Markus.Elfring@web.de>]

Date: Thu, 13 Apr 2023 14:46:39 +0200

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: 1b9e97a2a95e4941dcfa968c4b2e04022e9a343e ("perf tools: Fix report -F symbol_from for data without branch info")
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 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 80c9960c37e5..f2ffaf90648e 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -1020,8 +1020,7 @@ 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);
--
2.40.0