Re: Kconfig: ARCH=x86 causes wrong utsname.machine

Sam Ravnborg
2007-11-16T22:14:43Z

On Fri, Nov 16, 2007 at 07:20:15AM -0800, H. Peter Anvin wrote:
> Andreas Herrmann wrote:
> >The new ARCH=x86 kernel build causes weired machine strings on 32-bit.
> >For a cross-compiled kernel I have
> >
> > $ uname -m
> > x66_64
> >
> >For a kernel natively built on a 32 bit machine I have
> >
> > $ uname -m
> > x66
> >
> >Looking at the sources, I think that utsname->machine was initially
> >set as "x86_64" and "x86", respectively.
> >But in arch/x86/kernel/cpu/bugs.c in check_bugs() the second character
> >is set to '6' on my K7.
> >
> >I think the right solution for that problem is to use "x86_64" as the
> >machine name for 64-bit and to keep the old "i[3456]86" strings for
> >32-bit kernels.
>
> Absolutely. This would be userspace-visible ABI breakage.

Any good suggestions here???
UTS_MACHINE is set in top-level Makefile and if we specify
make ARCH=x86
we do not know if i386 or x86_&4 is correct until the configuration
has been read.

Should we report a "make ARCH=x86" as uname -m == x86??

Sam