ppc64 asan issue

[Joel Stanley]

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