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tsan: fix signal handling during stop-the-world
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Authored by dvyukov on Feb 18 2015, 5:57 AM.

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earthdok
Summary

Long story short: stop-the-world briefly resets SIGSEGV handler to SIG_DFL. This breaks programs that handle and continue after SIGSEGV (namely JVM). See the test and comments for details.

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dvyukov updated this revision to Diff 20166.Feb 18 2015, 5:57 AM
dvyukov retitled this revision from to tsan: fix signal handling during stop-the-world.
dvyukov updated this object.
dvyukov edited the test plan for this revision. (Show Details)
dvyukov added a reviewer: earthdok.
dvyukov added a subscriber: Unknown Object (MLST).
earthdok added inline comments.Feb 18 2015, 6:33 AM
lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
253

Why did you remove this?

268

We shouldn't ever run TracerThreadDieCallback() from other threads. It wouldn't work anyway.

I think TracerThreadDieCallback() should check that internal_getpid() == stoptheworld_tracer_pid. If not, just call the old callback.

earthdok edited edge metadata.Feb 18 2015, 6:33 AM

The general approach LGTM

dvyukov added inline comments.Feb 18 2015, 6:42 AM
lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
253

I see no reason for it to be here. We are going to die anyway, so why bother blocking signals?
If there is a reason for it to be here, then we need to comment this line.

268

Agree.
But this is a separate issue, let's fix it separately.

Committed revision 229678.