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SubjectRe: asm-x86/msr.h for sanitized headers: clean it or punt it
On Mon, Dec 31, 2007 at 01:49:27PM -0500, Mike Frysinger wrote:
> Use __asm__ and __volatile__ in code that is exported to userspace. Wrap
> kernel functions with __KERNEL__ so they get scrubbed.
>
> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
> ---
> diff --git a/include/asm-x86/msr.h b/include/asm-x86/msr.h
> index ba4b314..664a2fa 100644
> --- a/include/asm-x86/msr.h
> +++ b/include/asm-x86/msr.h
>...
> #define rdtscp(low,high,aux) \
> - asm volatile (".byte 0x0f,0x01,0xf9" : "=a" (low), "=d" (high), "=c" (aux))
> + __asm__ __volatile__ (".byte 0x0f,0x01,0xf9" : "=a" (low), "=d" (high), "=c" (aux))
>
> #define rdtscll(val) do { \
> unsigned int __a,__d; \
> - asm volatile("rdtsc" : "=a" (__a), "=d" (__d)); \
> + __asm__ __volatile__("rdtsc" : "=a" (__a), "=d" (__d)); \
> (val) = ((unsigned long)__a) | (((unsigned long)__d)<<32); \
> } while(0)
>
> #define rdtscpll(val, aux) do { \
> unsigned long __a, __d; \
> - asm volatile (".byte 0x0f,0x01,0xf9" : "=a" (__a), "=d" (__d), "=c" (aux)); \
> + __asm__ __volatile__ (".byte 0x0f,0x01,0xf9" : "=a" (__a), "=d" (__d), "=c" (aux)); \
> (val) = (__d << 32) | __a; \
> } while (0)
>...

How is this part of the kernel<->userspace interface?

Unless I miss anything this sounds more like userspace abusing kernel
headers as a utility library?

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed



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