From: Ian Rogers <irogers@google.com>
Date: Thu, 21 Aug 2025 16:38:15 +0000 (-0700)
Subject: perf disasm: Avoid undefined behavior in incrementing NULL
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=78d853512d6f979cf0cc41566e4f6cd82995ff34;p=users%2Fhch%2Fmisc.git

perf disasm: Avoid undefined behavior in incrementing NULL

Incrementing NULL is undefined behavior and triggers ubsan during the
perf annotate test.

Split a compound statement over two lines to avoid this.

Fixes: 98f69a573c668a18 ("perf annotate: Split out util/disasm.c")
Reviewed-by: Collin Funk <collin.funk1@gmail.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.ibm.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Chun-Tse Shao <ctshao@google.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Polensky <japo@linux.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Li Huafei <lihuafei1@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Nam Cao <namcao@linutronix.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20250821163820.1132977-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/util/disasm.c b/tools/perf/util/disasm.c
index b1e4919d016f..e257bd918c89 100644
--- a/tools/perf/util/disasm.c
+++ b/tools/perf/util/disasm.c
@@ -390,13 +390,16 @@ static int jump__parse(struct arch *arch, struct ins_operands *ops, struct map_s
 	 * skip over possible up to 2 operands to get to address, e.g.:
 	 * tbnz	 w0, #26, ffff0000083cd190 <security_file_permission+0xd0>
 	 */
-	if (c++ != NULL) {
+	if (c != NULL) {
+		c++;
 		ops->target.addr = strtoull(c, NULL, 16);
 		if (!ops->target.addr) {
 			c = strchr(c, ',');
 			c = validate_comma(c, ops);
-			if (c++ != NULL)
+			if (c != NULL) {
+				c++;
 				ops->target.addr = strtoull(c, NULL, 16);
+			}
 		}
 	} else {
 		ops->target.addr = strtoull(ops->raw, NULL, 16);