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<p><font size="2" face="sans-serif">Hi Will,</font><br>
<br>
<font size="2" face="sans-serif">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.</font><br>
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<font size="2" face="sans-serif">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. </font><br>
<br>
<font size="2" face="sans-serif">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.</font><br>
<br>
<font size="2" face="sans-serif">Thanks,</font><br>
<font size="2" face="sans-serif">Samuel</font><br>
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<img width="16" height="16" src="cid:1__=0ABBF7CCDFC699F98f9e8a93df938@us.ibm.com" border="0" alt="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: > A"><font size="2" color="#424282" face="sans-serif">Will Schmidt ---09/26/2014 11:25:23 AM---On Mon, 2014-09-08 at 22:00 -0400, Samuel F Antao wrote: > Alexey, Alexander,</font><br>
<br>
<font size="1" color="#5F5F5F" face="sans-serif">From: </font><font size="1" face="sans-serif">Will Schmidt <will_schmidt@vnet.ibm.com></font><br>
<font size="1" color="#5F5F5F" face="sans-serif">To: </font><font size="1" face="sans-serif">Samuel F Antao/Watson/IBM@IBMUS</font><br>
<font size="1" color="#5F5F5F" face="sans-serif">Cc: </font><font size="1" face="sans-serif">Alexander Potapenko <glider@google.com>, Clang Developers List <cfe-dev@cs.uiuc.edu>, LLVM Dev <llvmdev@cs.uiuc.edu></font><br>
<font size="1" color="#5F5F5F" face="sans-serif">Date: </font><font size="1" face="sans-serif">09/26/2014 11:25 AM</font><br>
<font size="1" color="#5F5F5F" face="sans-serif">Subject: </font><font size="1" face="sans-serif">Re: [LLVMdev] [cfe-dev] Address sanitizer regression test failures for PPC64 targets</font><br>
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<tt><font size="2">On Mon, 2014-09-08 at 22:00 -0400, Samuel F Antao wrote:<br>
> Alexey, Alexander,<br>
> <br>
> Thanks for the suggestions. I tried removing the flag SA_NODEFER but<br>
> it didn't do any good... I have been digging into the problem with the<br>
> null_deref test today but I was unable to clearly identify the<br>
> problem. I suspect that it was either a bug with the calling<br>
> convention/unwinding that lead to the flags() pointer to get<br>
> corrupted. It is also possible that it was related with endianess<br>
> issues caused by some bug in the pointer arithmetic inserted by the<br>
> sanitizer code (there are many type and bit casts which makes hard to<br>
> follow the<br>
<br>
> references). I decided to upgrade the compiler I was using to build<br>
> clang which made the problem with this testcase to go away (!).<br>
<br>
Hi Samuel, <br>
Which compiler versions were you using before/after ? At the moment,<br>
I'm building with a gcc 4.9 snapshot, but can switch to something newer<br>
if you had a recommendation.<br>
<br>
Thanks, <br>
-Will<br>
<br>
</font></tt><br>
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