[compiler-rt] r227230 - tsan: properly instrument unaligned accesses

[Dmitry Vyukov]

Hummm....

Just checked out latest clang (228284), all tests pass like a charm.

I think mine is configured with clang. But I don't see how it can make
a difference, because the test is built with the new clang... unless
tsan runtime is miscompiled by one of the host compilers.

Do you have llvm-symbolizer in PATH? Is it of the latest version? That
could explain simple_stack failures.



On Mon, Feb 2, 2015 at 10:33 AM, Yury Gribov <y.gribov at samsung.com> wrote:
> On 02/01/2015 11:00 PM, Dmitry Vyukov wrote:
>>
>> On Fri, Jan 30, 2015 at 4:48 PM, Yury Gribov <y.gribov at samsung.com> wrote:
>>>
>>> On 01/27/2015 11:19 PM, Dmitry Vyukov wrote:
>>>>
>>>>
>>>> Author: dvyukov
>>>> Date: Tue Jan 27 14:19:12 2015
>>>> New Revision: 227230
>>>>
>>>> URL: http://llvm.org/viewvc/llvm-project?rev=227230&view=rev
>>>> Log:
>>>> tsan: properly instrument unaligned accesses
>>>>
>>>> If a memory access is unaligned, emit __tsan_unaligned_read/write
>>>> callbacks instead of __tsan_read/write.
>>>> Required to change semantics of __tsan_unaligned_read/write to not do
>>>> the
>>>> user memory.
>>>> But since they were unused (other than through
>>>> __sanitizer_unaligned_load/store) this is fine.
>>>> Fixes long standing issue 17:
>>>> https://code.google.com/p/thread-sanitizer/issues/detail?id=17
>>>
>>>
>>>
>>> FYI I've been seeing TSan regressions on Ubuntu 14 lately:
>>>
>>> FAIL: ThreadSanitizer :: aligned_vs_unaligned_race.cc (21921 of 22245)
>>> ******************** TEST 'ThreadSanitizer ::
>>> aligned_vs_unaligned_race.cc'
>>> FAILED ********************
>>> Script:
>>> --
>>> /home/ygribov/build/llvm-master-gcc/./bin/clang --driver-mode=g++
>>> -fsanitize=thread -Wall -m64 -gline-tables-only -O1
>>>
>>> /home/ygribov/src/llvm-master/projects/compiler-rt/test/tsan/aligned_vs_unaligned_race.cc
>>> -o
>>>
>>> /home/ygribov/build/llvm-master-gcc/projects/compiler-rt/test/tsan/Output/aligned_vs_unaligned_race.cc.tmp
>>> &&
>>> /home/ygribov/src/llvm-master/projects/compiler-rt/test/tsan/deflake.bash
>>>
>>> /home/ygribov/build/llvm-master-gcc/projects/compiler-rt/test/tsan/Output/aligned_vs_unaligned_race.cc.tmp
>>> | FileCheck
>>>
>>> /home/ygribov/src/llvm-master/projects/compiler-rt/test/tsan/aligned_vs_unaligned_race.cc
>>> --
>>> Exit Code: 2
>>>
>>> Command Output (stderr):
>>> --
>>> FileCheck error: '-' is empty.
>>
>>
>>
>> Hi Yuri,
>>
>> Please provide exact reproduction instructions.
>
>
> I was just doing a regular make check-all on TOT Clang+LLVM+compiler-rt.
>
> I configured with -DLLVM_TARGETS_TO_BUILD=X86
> -DCOMPILER_RT_BUILD_SHARED_ASAN=ON and used standard system compiler (Ubuntu
> 4.8.2-19ubuntu1).
>
> -Y
>