Subject: Re: [PATCH] powerpc: 32 bit getcpu VDSO function uses 64 bit instructions

From: Segher Boessenkool <[email-masked]>
Date: Wed, 26 Nov 2014 17:23:18 -0600

On Thu, Nov 27, 2014 at 09:38:17AM +1100, Michael Ellerman wrote:
> On Thu, 2014-11-27 at 08:11 +1100, Anton Blanchard wrote:
> > I used some 64 bit instructions when adding the 32 bit getcpu VDSO
> > function. Fix it.
> 
> Ouch. The symptom is a SIGILL I presume?
> 
> Could we catch this by forcing -m32 in the CFLAGS for vdso32 ?

GCC has added -many to the assembler flags for over ten years now, so
no that will not work.  You can use -mppc or similar with the assembler
if you invoke it correctly (use  $(CC) -print-prog-name=as  to figure
out how to call the assembler, if you want to stay sane and use the
same one as the rest of the toolchain you use).

Segher