[PATCH v1] perf intel-pt: Fix memory sanitizer use-of-uninitialized-value

[PATCH v1] perf intel-pt: Fix memory sanitizer use-of-uninitialized-value

[Ian Rogers]

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@google.com>
---
 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

Re: [PATCH v1] perf intel-pt: Fix memory sanitizer use-of-uninitialized-value

[Ian Rogers]

On Wed, Mar 20, 2024 at 9:26 AM Ian Rogers <irogers@google.com> wrote:
>
> 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@google.com>

Adrian, could you take a look at this for the sake of tests passing with msan.

Thanks,
Ian

> ---
>  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
>

Re: [PATCH v1] perf intel-pt: Fix memory sanitizer use-of-uninitialized-value

[Adrian Hunter]

On 25/03/24 17:44, Ian Rogers wrote:
> On Wed, Mar 20, 2024 at 9:26 AM Ian Rogers <irogers@google.com> wrote:
>>
>> 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@google.com>
> 
> Adrian, could you take a look at this for the sake of tests passing with msan.

I did have a look, but I found msan so slow and full of errors
that it never gave any results.

However, it is easy enough to instrument some debugging which is
what I am still looking at.

Just initializing intel_pt_insn is not quite right, so I need
to check things a bit more.

> 
> Thanks,
> Ian
> 
>> ---
>>  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
>>

[PATCH] perf intel-pt: Fix unassigned instruction op

[Adrian Hunter]

MemorySanitizer discovered instances where the instruction op value was
not assigned.:

  WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x5581c00a76b3 in intel_pt_sample_flags tools/perf/util/intel-pt.c:1527:17
  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

The op value is used to set branch flags for branch instructions
encountered when walking the code, so fix by setting op to
INTEL_PT_OP_OTHER in other cases.

Reported-by: Ian Rogers <irogers@google.com>
Closes: https://lore.kernel.org/linux-perf-users/20240320162619.1272015-1-irogers@google.com/
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 2 ++
 tools/perf/util/intel-pt.c                          | 2 ++
 2 files changed, 4 insertions(+)

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..e733f6b1f7ac 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1319,6 +1319,8 @@ static bool intel_pt_fup_event(struct intel_pt_decoder *decoder, bool no_tip)
 	bool ret = false;
 
 	decoder->state.type &= ~INTEL_PT_BRANCH;
+	decoder->state.insn_op = INTEL_PT_OP_OTHER;
+	decoder->state.insn_len = 0;
 
 	if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
 		bool ip = decoder->set_fup_cfe_ip;
diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index f38893e0b036..4db9a098f592 100644
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -764,6 +764,7 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
 
 	addr_location__init(&al);
 	intel_pt_insn->length = 0;
+	intel_pt_insn->op = INTEL_PT_OP_OTHER;
 
 	if (to_ip && *ip == to_ip)
 		goto out_no_cache;
@@ -898,6 +899,7 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
 
 			if (to_ip && *ip == to_ip) {
 				intel_pt_insn->length = 0;
+				intel_pt_insn->op = INTEL_PT_OP_OTHER;
 				goto out_no_cache;
 			}
 
-- 
2.34.1

Re: [PATCH] perf intel-pt: Fix unassigned instruction op

[Ian Rogers]

On Tue, Mar 26, 2024 at 1:32 AM Adrian Hunter <adrian.hunter@intel.com> wrote:
>
> MemorySanitizer discovered instances where the instruction op value was
> not assigned.:
>
>   WARNING: MemorySanitizer: use-of-uninitialized-value
>     #0 0x5581c00a76b3 in intel_pt_sample_flags tools/perf/util/intel-pt.c:1527:17
>   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
>
> The op value is used to set branch flags for branch instructions
> encountered when walking the code, so fix by setting op to
> INTEL_PT_OP_OTHER in other cases.
>
> Reported-by: Ian Rogers <irogers@google.com>
> Closes: https://lore.kernel.org/linux-perf-users/20240320162619.1272015-1-irogers@google.com/
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>

Great, thanks! Should it have a Fixes tag like:

Fixes: 4c761d805bb2 ("perf intel-pt: Fix intel_pt_fup_event()
assumptions about setting state type")

Tested-by: Ian Rogers <irogers@google.com>

Ian

> ---
>  tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 2 ++
>  tools/perf/util/intel-pt.c                          | 2 ++
>  2 files changed, 4 insertions(+)
>
> 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..e733f6b1f7ac 100644
> --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
> +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
> @@ -1319,6 +1319,8 @@ static bool intel_pt_fup_event(struct intel_pt_decoder *decoder, bool no_tip)
>         bool ret = false;
>
>         decoder->state.type &= ~INTEL_PT_BRANCH;
> +       decoder->state.insn_op = INTEL_PT_OP_OTHER;
> +       decoder->state.insn_len = 0;
>
>         if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
>                 bool ip = decoder->set_fup_cfe_ip;
> diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
> index f38893e0b036..4db9a098f592 100644
> --- a/tools/perf/util/intel-pt.c
> +++ b/tools/perf/util/intel-pt.c
> @@ -764,6 +764,7 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
>
>         addr_location__init(&al);
>         intel_pt_insn->length = 0;
> +       intel_pt_insn->op = INTEL_PT_OP_OTHER;
>
>         if (to_ip && *ip == to_ip)
>                 goto out_no_cache;
> @@ -898,6 +899,7 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
>
>                         if (to_ip && *ip == to_ip) {
>                                 intel_pt_insn->length = 0;
> +                               intel_pt_insn->op = INTEL_PT_OP_OTHER;
>                                 goto out_no_cache;
>                         }
>
> --
> 2.34.1
>

Re: [PATCH] perf intel-pt: Fix unassigned instruction op

[Adrian Hunter]

On 26/03/24 18:13, Ian Rogers wrote:
> On Tue, Mar 26, 2024 at 1:32 AM Adrian Hunter <adrian.hunter@intel.com> wrote:
>>
>> MemorySanitizer discovered instances where the instruction op value was
>> not assigned.:
>>
>>   WARNING: MemorySanitizer: use-of-uninitialized-value
>>     #0 0x5581c00a76b3 in intel_pt_sample_flags tools/perf/util/intel-pt.c:1527:17
>>   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
>>
>> The op value is used to set branch flags for branch instructions
>> encountered when walking the code, so fix by setting op to
>> INTEL_PT_OP_OTHER in other cases.
>>
>> Reported-by: Ian Rogers <irogers@google.com>
>> Closes: https://lore.kernel.org/linux-perf-users/20240320162619.1272015-1-irogers@google.com/
>> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> 
> Great, thanks! Should it have a Fixes tag like:
> 
> Fixes: 4c761d805bb2 ("perf intel-pt: Fix intel_pt_fup_event()
> assumptions about setting state type")

Yes, I should have put a fixes tag, cc stable.  I think the issue
has always been there, so:

Fixes: 90e457f7be087 ("perf tools: Add Intel PT support")
Cc: stable@vger.kernel.org

> 
> Tested-by: Ian Rogers <irogers@google.com>
> 
> Ian
> 
>> ---
>>  tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 2 ++
>>  tools/perf/util/intel-pt.c                          | 2 ++
>>  2 files changed, 4 insertions(+)
>>
>> 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..e733f6b1f7ac 100644
>> --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
>> +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
>> @@ -1319,6 +1319,8 @@ static bool intel_pt_fup_event(struct intel_pt_decoder *decoder, bool no_tip)
>>         bool ret = false;
>>
>>         decoder->state.type &= ~INTEL_PT_BRANCH;
>> +       decoder->state.insn_op = INTEL_PT_OP_OTHER;
>> +       decoder->state.insn_len = 0;
>>
>>         if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
>>                 bool ip = decoder->set_fup_cfe_ip;
>> diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
>> index f38893e0b036..4db9a098f592 100644
>> --- a/tools/perf/util/intel-pt.c
>> +++ b/tools/perf/util/intel-pt.c
>> @@ -764,6 +764,7 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
>>
>>         addr_location__init(&al);
>>         intel_pt_insn->length = 0;
>> +       intel_pt_insn->op = INTEL_PT_OP_OTHER;
>>
>>         if (to_ip && *ip == to_ip)
>>                 goto out_no_cache;
>> @@ -898,6 +899,7 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
>>
>>                         if (to_ip && *ip == to_ip) {
>>                                 intel_pt_insn->length = 0;
>> +                               intel_pt_insn->op = INTEL_PT_OP_OTHER;
>>                                 goto out_no_cache;
>>                         }
>>
>> --
>> 2.34.1
>>

Re: [PATCH] perf intel-pt: Fix unassigned instruction op

[Arnaldo Carvalho de Melo]

On Tue, Mar 26, 2024 at 06:52:12PM +0200, Adrian Hunter wrote:
> On 26/03/24 18:13, Ian Rogers wrote:
> > On Tue, Mar 26, 2024 at 1:32 AM Adrian Hunter <adrian.hunter@intel.com> wrote:
> >>
> >> MemorySanitizer discovered instances where the instruction op value was
> >> not assigned.:
> >>
> >>   WARNING: MemorySanitizer: use-of-uninitialized-value
> >>     #0 0x5581c00a76b3 in intel_pt_sample_flags tools/perf/util/intel-pt.c:1527:17
> >>   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
> >>
> >> The op value is used to set branch flags for branch instructions
> >> encountered when walking the code, so fix by setting op to
> >> INTEL_PT_OP_OTHER in other cases.
> >>
> >> Reported-by: Ian Rogers <irogers@google.com>
> >> Closes: https://lore.kernel.org/linux-perf-users/20240320162619.1272015-1-irogers@google.com/
> >> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> > 
> > Great, thanks! Should it have a Fixes tag like:
> > 
> > Fixes: 4c761d805bb2 ("perf intel-pt: Fix intel_pt_fup_event()
> > assumptions about setting state type")
> 
> Yes, I should have put a fixes tag, cc stable.  I think the issue
> has always been there, so:
> 
> Fixes: 90e457f7be087 ("perf tools: Add Intel PT support")
> Cc: stable@vger.kernel.org

Thanks, applied, had fell thru the cracks :-\

- Arnaldo
 
> > 
> > Tested-by: Ian Rogers <irogers@google.com>
> > 
> > Ian
> > 
> >> ---
> >>  tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 2 ++
> >>  tools/perf/util/intel-pt.c                          | 2 ++
> >>  2 files changed, 4 insertions(+)
> >>
> >> 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..e733f6b1f7ac 100644
> >> --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
> >> +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
> >> @@ -1319,6 +1319,8 @@ static bool intel_pt_fup_event(struct intel_pt_decoder *decoder, bool no_tip)
> >>         bool ret = false;
> >>
> >>         decoder->state.type &= ~INTEL_PT_BRANCH;
> >> +       decoder->state.insn_op = INTEL_PT_OP_OTHER;
> >> +       decoder->state.insn_len = 0;
> >>
> >>         if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
> >>                 bool ip = decoder->set_fup_cfe_ip;
> >> diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
> >> index f38893e0b036..4db9a098f592 100644
> >> --- a/tools/perf/util/intel-pt.c
> >> +++ b/tools/perf/util/intel-pt.c
> >> @@ -764,6 +764,7 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
> >>
> >>         addr_location__init(&al);
> >>         intel_pt_insn->length = 0;
> >> +       intel_pt_insn->op = INTEL_PT_OP_OTHER;
> >>
> >>         if (to_ip && *ip == to_ip)
> >>                 goto out_no_cache;
> >> @@ -898,6 +899,7 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
> >>
> >>                         if (to_ip && *ip == to_ip) {
> >>                                 intel_pt_insn->length = 0;
> >> +                               intel_pt_insn->op = INTEL_PT_OP_OTHER;
> >>                                 goto out_no_cache;
> >>                         }
> >>
> >> --
> >> 2.34.1
> >>
>