ppc64 asan issue

[Michael Ellerman]

William Kennington <wak at google.com> writes:
> I'm doing autodetection for it now, but it is something I need to test
> with a compiler closer to upstream.
> https://github.com/openbmc/openbmc-build-scripts/commit/0b7fb2bcfd603949f9999127f56e3fc0e0351fbc

For me on 18.04 with GCC 8 it works OK (just a small test program, not
openbmc). Whereas with GCC 7 I get ASAN asserts when compiling.

So I wonder what exact GCC 8 version you're using.

I have: gcc-8 (Ubuntu 8.2.0-1ubuntu2~18.04) 8.2.0


There's a GCC bug tracking some backports to GCC 8:
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89308

But it's not clear if they will fix your problem or not.

cheers

> On Tue, Feb 12, 2019 at 3:03 AM Joel Stanley <joel at jms.id.au> wrote:
>>
>> Hi William,
>>
>> I saw this change to our build scripts, where we disable the sanitiser
>> for ppc64:
>>
>> https://github.com/openbmc/openbmc-build-scripts/commit/282e33011ea62fe80bff2c5ab0e9ef9446d6c551
>>
>> It would be great if you could open a bug report about this one. As a
>> starting point it should file it against GCC, but even an openbmc
>> issue would be a good start.
>>
>> I did some investigation myself and I could reproduce the failure on
>> GCC 7 on Ubuntu 18.04 ppc64le. It didn't happen with GCC 8, nor with
>> GCC trunk.
>>
>> However even GCC 7 took a few compiles before I started hitting the
>> issue, so my testing may have not been comprehensive.
>>
>> Cheers,
>>
>> Joel
>>
>> --
>> My testing looked like this:
>>
>> $ cat san.c
>> #include <stdlib.h>
>> #include <stdio.h>
>>
>> int main()
>> {
>>     void *p = malloc(4);
>>     printf("%p\n", p);
>>     return 0;
>> }
>> $ gcc -fsanitize=address -o san{,.c}
>> $ ./san