[CRIU] [PATCH] Fix gcc9 build failures

[Salvatore Bonaccorso]

Hi,

On Wed, Jan 09, 2019 at 12:49:11PM +0000, Adrian Reber wrote:
> From: Adrian Reber <areber at redhat.com>
> 
> I received this patch from Jeff Law as a fix for build failures with the
> upcoming GCC 9. The following is Jeff Law's description of the patch:
> 
>  Attached you'll find the fix for criu.  You'll see it's just a matter
>  of dropping the sp/esp clobber from the relevant asm statements.  THe
>  details:
> 
>  criu has a macro which defines an asm which appears to want to set a new
>  stack pointer, then directly issue a sigreturn call to the kernel.  Some
>  variants clobber sp (aarch64, arm, x86), others do not (ppc, s390)
> 
>  While the asm does indeed set a new stack pointer, we never return from
>  a sigreturn syscall -- at least not in the normal way.  We actually
>  return back to the point where the process was interrupted by the
>  signal.  So describing the affect of the asm on the stack pointer is
>  pedantically correct, it actually has no real effect and can just be
>  dropped to avoid the hard error from gcc-9.

In Debian, with gcc-9 we are seeing as well build failures on ppc64el
and s390x similarly. See:

https://buildd.debian.org/status/fetch.php?pkg=criu&arch=s390x&ver=3.12-1&stamp=1570688225&raw=0
https://buildd.debian.org/status/fetch.php?pkg=criu&arch=ppc64el&ver=3.12-1&stamp=1570688342&raw=0

Regards,
Salvatore