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[compiler-rt][UBSan] silence_unsigned_overflow: do *NOT* ignore *fatal* unsigned overflows
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Authored by lebedev.ri on Nov 20 2018, 1:05 PM.

Details

Summary

D48660 / rL335762 added a silence_unsigned_overflow env flag for oss-fuzz needs,
that allows to silence the reports from unsigned overflows.
It makes sense, it is there because -fsanitize=integer sanitizer is not enabled on oss-fuzz,
so this allows to still use it as an interestingness signal, without getting the actual reports.

However there is a slight problem here.
All types of unsigned overflows are ignored.
Even if -fno-sanitize-recover=unsigned was used (which means the program will die after the report)
there will still be no report, the program will just silently die.

At the moment there are just two projects on oss-fuzz that care:

I suppose this could be overridden there ^, but i really don't think this is intended behavior in any case..

Diff Detail

Event Timeline

lebedev.ri created this revision.Nov 20 2018, 1:05 PM

Adjust the help text, too.

Dor1s accepted this revision.Nov 21 2018, 12:36 PM

Nice! LGTM!

This revision is now accepted and ready to land.Nov 21 2018, 12:36 PM

Roman, I can land this CL for you next week, unless other reviewers have any complains :)

Nice! LGTM!

Thank you for the speedy review!

This revision was automatically updated to reflect the committed changes.