[LLVMdev] [cfe-dev] Address sanitizer regression test failures for PPC64 targets

[Hal Finkel]

Samuel,

Was this ever resolved?

 -Hal

----- Original Message -----
> From: "Samuel F Antao" <sfantao at us.ibm.com>
> To: "will schmidt" <will_schmidt at vnet.ibm.com>
> Cc: "Clang Developers List" <cfe-dev at cs.uiuc.edu>, "LLVM Dev" <llvmdev at cs.uiuc.edu>
> Sent: Friday, September 26, 2014 10:40:06 AM
> Subject: Re: [LLVMdev] [cfe-dev] Address sanitizer regression test failures for PPC64 targets
> 
> 
> 
> 
> Hi Will,
> 
> Do the sanitizer tests work for you with gcc 4.9? I was using clang
> 3.4.2 and started using clang 3.5.0. For both versions, I configured
> clang to use the gcc 4.8.2 tooIchain.
> 
> My understanding is that the compiler was not the problem but an
> endianess issue in the sanitizer implementation that was causing
> memory to get corrupted. The different versions of compiler just
> caused the memory corruption to affect different ranges, causing
> some tests that were not working to start working and vice-versa.
> 
> I identified one of the places with the endianess issue in my
> previous email. I'm unsure whether there are other places in the
> code that only work for little endian.
> 
> Thanks,
> Samuel
> 
> Inactive hide details for Will Schmidt ---09/26/2014 11:25:23 AM---On
> Mon, 2014-09-08 at 22:00 -0400, Samuel F Antao wrote: > AWill
> Schmidt ---09/26/2014 11:25:23 AM---On Mon, 2014-09-08 at 22:00
> -0400, Samuel F Antao wrote: > Alexey, Alexander,
> 
> From: Will Schmidt <will_schmidt at vnet.ibm.com>
> To: Samuel F Antao/Watson/IBM at IBMUS
> Cc: Alexander Potapenko <glider at google.com>, Clang Developers List
> <cfe-dev at cs.uiuc.edu>, LLVM Dev <llvmdev at cs.uiuc.edu>
> Date: 09/26/2014 11:25 AM
> Subject: Re: [LLVMdev] [cfe-dev] Address sanitizer regression test
> failures for PPC64 targets
> 
> 
> 
> 
> On Mon, 2014-09-08 at 22:00 -0400, Samuel F Antao wrote:
> > Alexey, Alexander,
> > 
> > Thanks for the suggestions. I tried removing the flag SA_NODEFER
> > but
> > it didn't do any good... I have been digging into the problem with
> > the
> > null_deref test today but I was unable to clearly identify the
> > problem. I suspect that it was either a bug with the calling
> > convention/unwinding that lead to the flags() pointer to get
> > corrupted. It is also possible that it was related with endianess
> > issues caused by some bug in the pointer arithmetic inserted by the
> > sanitizer code (there are many type and bit casts which makes hard
> > to
> > follow the
> 
> > references). I decided to upgrade the compiler I was using to build
> > clang which made the problem with this testcase to go away (!).
> 
> Hi Samuel,
> Which compiler versions were you using before/after ? At the moment,
> I'm building with a gcc 4.9 snapshot, but can switch to something
> newer
> if you had a recommendation.
> 
> Thanks,
> -Will
> 
> 
> 
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-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory