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

Adrian Hunter posted 1 patch 1 year, 10 months ago 
tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 2 ++
tools/perf/util/intel-pt.c                          | 2 ++
2 files changed, 4 insertions(+)
[PATCH] perf intel-pt: Fix unassigned instruction op
Posted by Adrian Hunter 1 year, 10 months ago 
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
Posted by Ian Rogers 1 year, 10 months ago 
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
Posted by Adrian Hunter 1 year, 10 months ago 
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
Posted by Arnaldo Carvalho de Melo 1 year, 9 months ago 
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
> >>
>

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