1346725 - [Static Analysis][Dereference before null check] In function DoSampleStackTrace

Status: RESOLVED FIXED

(Core :: Gecko Profiler, defect)

Description

[Andi [:andi]]

The Static Analysis tool Coverity detected that |aSample| is null checked after being dereferenced witch implies that a potential null pointer dereference can happen. 
Looking at the places where DoSampleStackTrace gets called we have:

>>#if defined(USE_NS_STACKWALK) || defined(USE_EHABI_STACKWALK) || \
>>    defined(USE_LUL_STACKWALK)
>>  if (gPS->FeatureStackWalk(aLock)) {
>>    DoNativeBacktrace(aLock, aBuffer, aSample);
>>  } else {
>>    DoSampleStackTrace(aLock, aBuffer, aSample);
>>  }
>>#else
>>  DoSampleStackTrace(aLock, aBuffer, aSample);
>>#endif

from function |Tick|, that also gets called in one place:

>>  sample.isSamplingCurrentThread = true;
>>  sample.timestamp = mozilla::TimeStamp::Now();
>>
>>  Tick(lock, buffer, &sample);

Being |sample| passed as an address we can consider that the null check is useless.

Comment 1

[Andi [:andi]]

Attachment: Bug 1346725 - removed useless null check in DoSampleStackTrace.

Review commit: https://reviewboard.mozilla.org/r/119622/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/119622/

Comment 2

[Markus Stange [:mstange]]

Comment on attachment 8846569 [details]
Bug 1346725 - removed useless null check in DoSampleStackTrace.

https://reviewboard.mozilla.org/r/119622/#review122126

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8a30570bc738
removed useless null check in DoSampleStackTrace. r=mstange

Comment 4

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/8a30570bc738