[PATCH v1] perf intel-pt: Fix memory sanitizer use-of-uninitialized-value
From: Ian Rogers
Date: Wed Mar 20 2024 - 12:26:32 EST
Running the test "Miscellaneous Intel PT testing" with a build with
-fsanitize=memory and -fsanitize-memory-track-origins I saw:
```
==1257749==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x5581c00a76b3 in intel_pt_sample_flags tools/perf/util/intel-pt.c:1527:17
#1 0x5581c00c5cf6 in intel_pt_run_decoder tools/perf/util/intel-pt.c:2961:3
#2 0x5581c00968f8 in intel_pt_process_timeless_queues tools/perf/util/intel-pt.c:3074:4
#3 0x5581c007cf49 in intel_pt_process_event tools/perf/util/intel-pt.c:3482:10
#4 0x5581bffa269a in auxtrace__process_event tools/perf/util/auxtrace.c:2830:9
#5 0x5581bfb826c0 in perf_session__deliver_event tools/perf/util/session.c:1649:8
#6 0x5581bfba1d7f in perf_session__process_event tools/perf/util/session.c:1891:9
#7 0x5581bfba82e4 in process_simple tools/perf/util/session.c:2452:9
#8 0x5581bfbabcc3 in reader__read_event tools/perf/util/session.c:2381:14
#9 0x5581bfbad942 in reader__process_events tools/perf/util/session.c:2430:8
#10 0x5581bfb78256 in __perf_session__process_events tools/perf/util/session.c:2477:8
#11 0x5581bfb702c4 in perf_session__process_events tools/perf/util/session.c:2643:9
#12 0x5581bf2da266 in __cmd_script tools/perf/builtin-script.c:2855:8
#13 0x5581bf2bfcdd in cmd_script tools/perf/builtin-script.c:4402:8
#14 0x5581bf67004b in run_builtin tools/perf/perf.c:350:11
#15 0x5581bf66b8ea in handle_internal_command tools/perf/perf.c:403:8
#16 0x5581bf66f527 in run_argv tools/perf/perf.c:447:2
#17 0x5581bf669d2d in main tools/perf/perf.c:561:3
Uninitialized value was stored to memory at
#0 0x5581c005ddf8 in intel_pt_walk_insn tools/perf/util/intel-pt-decoder/intel-pt-decoder.c:1256:25
#1 0x5581c001a932 in intel_pt_walk_fup tools/perf/util/intel-pt-decoder/intel-pt-decoder.c:1428:9
#2 0x5581c000f76c in intel_pt_walk_trace tools/perf/util/intel-pt-decoder/intel-pt-decoder.c:3299:10
#3 0x5581c000899b in intel_pt_decode tools/perf/util/intel-pt-decoder/intel-pt-decoder.c:3988:10
#4 0x5581c00c5180 in intel_pt_run_decoder tools/perf/util/intel-pt.c:2941:11
#5 0x5581c00968f8 in intel_pt_process_timeless_queues tools/perf/util/intel-pt.c:3074:4
#6 0x5581c007cf49 in intel_pt_process_event tools/perf/util/intel-pt.c:3482:10
#7 0x5581bffa269a in auxtrace__process_event tools/perf/util/auxtrace.c:2830:9
#8 0x5581bfb826c0 in perf_session__deliver_event tools/perf/util/session.c:1649:8
#9 0x5581bfba1d7f in perf_session__process_event tools/perf/util/session.c:1891:9
#10 0x5581bfba82e4 in process_simple tools/perf/util/session.c:2452:9
#11 0x5581bfbabcc3 in reader__read_event tools/perf/util/session.c:2381:14
#12 0x5581bfbad942 in reader__process_events tools/perf/util/session.c:2430:8
#13 0x5581bfb78256 in __perf_session__process_events tools/perf/util/session.c:2477:8
#14 0x5581bfb702c4 in perf_session__process_events tools/perf/util/session.c:2643:9
#15 0x5581bf2da266 in __cmd_script tools/perf/builtin-script.c:2855:8
#16 0x5581bf2bfcdd in cmd_script tools/perf/builtin-script.c:4402:8
#17 0x5581bf67004b in run_builtin tools/perf/perf.c:350:11
#18 0x5581bf66b8ea in handle_internal_command tools/perf/perf.c:403:8
#19 0x5581bf66f527 in run_argv tools/perf/perf.c:447:2
```
Adding a curly brace initializer for the intel_pt_insn in
intel_pt_walk_fup rectifies this, however, there may be other issues
lurking behind this so initialize all similar instances.
Fixes: f4aa081949e7 ("perf tools: Add Intel PT decoder")
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
index b450178e3420..b4a95af2e4cc 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1115,7 +1115,7 @@ static void intel_pt_sample_insn(struct intel_pt_decoder *decoder)
*/
static void intel_pt_sample_fup_insn(struct intel_pt_decoder *decoder)
{
- struct intel_pt_insn intel_pt_insn;
+ struct intel_pt_insn intel_pt_insn = {};
uint64_t max_insn_cnt, insn_cnt = 0;
int err;
@@ -1418,7 +1418,7 @@ static inline bool intel_pt_fup_with_nlip(struct intel_pt_decoder *decoder,
static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
{
- struct intel_pt_insn intel_pt_insn;
+ struct intel_pt_insn intel_pt_insn = {};
uint64_t ip;
int err;
@@ -1461,7 +1461,7 @@ static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
{
- struct intel_pt_insn intel_pt_insn;
+ struct intel_pt_insn intel_pt_insn = {};
int err;
err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
@@ -1626,7 +1626,7 @@ static int intel_pt_emulated_ptwrite(struct intel_pt_decoder *decoder)
static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
{
- struct intel_pt_insn intel_pt_insn;
+ struct intel_pt_insn intel_pt_insn = {};
int err;
while (1) {
--
2.44.0.291.gc1ea87d7ee-goog