[PATCHv3][PING] Enable -fsanitize-recover for KASan

[Jakub Jelinek]

On Mon, Sep 29, 2014 at 05:24:02PM -0700, Konstantin Serebryany wrote:
> > I don't think we ever going to support recovery for regular ASan
> > (Kostya, correct me if I'm wrong).
> 
> I hope so too.
> Another point is that with asan-instrumentation-with-call-threshold=0
> (instrumentation with callbacks)

The normal (non-recovery) callbacks are __attribute__((noreturn)) for
performance reasons, and you do need different callbacks and different
generated code if you want to recover (after the callback you need jump
back to a basic block after the conditional jump).
So, in that case you would need -fsanitize-recover=address.

> > I see no problem in enabling -fsanitize-recover by default for
> > -fsanitize=undefined and
> 
> This becomes more interesting when we use asan and ubsan together.

That is fairly common case.

	Jakub