Re: [RFC-PATCH] x86: really use __builtin_memcmp on x86_32

Harvey Harrison
2008-11-10T16:53:29Z

On Mon, 2008-11-10 at 09:05 +0100, Ingo Molnar wrote:
> * Ingo Molnar <mingo@elte.hu> wrote:
>
> > * Harvey Harrison <harvey.harrison@gmail.com> wrote:
> >
> > > Impact: prevent generic code from overriding __builtin_memcmp
> > >
> > > lib/string.c was using a generic implementation of memcmp
> > > because __HAVE_ARCH_MEMCMP was not defined and it was then doing
> > > #undef memcmp and defining a generic version.
> > >
> > > Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
> > > ---
> > > arch/x86/include/asm/string_32.h | 1 +
> > > 1 files changed, 1 insertions(+), 0 deletions(-)
> >
> > > +#define __HAVE_ARCH_MEMCMP
> > > #define memcmp __builtin_memcmp
> > >
> > > #define __HAVE_ARCH_MEMCHR
>
> doesnt work that well:
>
> arch/x86/kernel/built-in.o: In function `efi_guidcmp':
> efi.c:(.text+0x108b2): undefined reference to `memcmp'
> arch/x86/kernel/built-in.o: In function `smp_check_mpc':
> mpparse.c:(.init.text+0x4ec6): undefined reference to `memcmp'
> arch/x86/kernel/built-in.o: In function `powernowk8_cpu_init':
>
> with the attached config.
>

Just let this one go to the bitbucket.

Harvey