x86-32: Use symbolic constants, safer CPUID when enabling EFER.NX
x86-32: Use symbolic constants, safer CPUID when enabling EFER.NX

Use symbolic constants rather than hard-coded values when setting
EFER.NX in head_32.S, and do a more rigorous test for the validity of
the response when probing for the extended CPUID range.

Signed-off-by: H. Peter Anvin <8a453bad9912ffe59bc0f0b8abe03df9be19379e@zytor.com>
LKML-Reference: <1258154897-6770-2-git-send-email-8a453bad9912ffe59bc0f0b8abe03df9be19379e@zytor.com>
Acked-by: Kees Cook <e9b0cc8b545b1477b7cee8fbfcd6abb9c2d70cb5@canonical.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs