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Message-Id: <200712311310.32337.vapier@gentoo.org>
Date: Mon, 31 Dec 2007 13:10:31 -0500
From: Mike Frysinger <vapier@...too.org>
To: Andi Kleen <andi@...stfloor.org>
Cc: tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
LKML <linux-kernel@...r.kernel.org>
Subject: Re: asm-x86/msr.h for sanitized headers: clean it or punt it
On Monday 31 December 2007, Andi Kleen wrote:
> > can you enumerate which functions need to actually go to userspace then ?
> > the
>
> rdtscl/rdtscll/rdpmc primarily
i'll just mark out the useless C funcs then
> > __KERNEL__ markings are a crapshoot at the moment. you must also be
> > jumping through hoops in order to use the header in the first place since
> > the vanilla one wont compile out of the box.
>
> At least the 64bit one or older 32bit one works without hoops. Agreed that
> the paravirt changes destroyed it on newer 32bit though. That's an
> unfortunate regression.
i dont see how when the exported code has prototypes with "u32" types in them.
but at any rate ...
---
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@...too.org>
---
diff --git a/include/asm-x86/msr.h b/include/asm-x86/msr.h
index ba4b314..ffb9319 100644
--- a/include/asm-x86/msr.h
+++ b/include/asm-x86/msr.h
@@ -193,7 +193,7 @@ static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
/* wrmsr with exception handling */
#define wrmsr_safe(msr,a,b) ({ int ret__; \
- asm volatile("2: wrmsr ; xorl %0,%0\n" \
+ __asm__ __volatile__("2: wrmsr ; xorl %0,%0\n" \
"1:\n\t" \
".section .fixup,\"ax\"\n\t" \
"3: movl %4,%0 ; jmp 1b\n\t" \
@@ -210,7 +210,7 @@ static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
#define rdmsr_safe(msr,a,b) \
({ int ret__; \
- asm volatile ("1: rdmsr\n" \
+ __asm__ __volatile__ ("1: rdmsr\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: movl %4,%0\n" \
@@ -230,17 +230,17 @@ static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
__asm__ __volatile__ ("rdtsc" : "=a" (low) : : "edx")
#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)
@@ -320,6 +320,7 @@ static inline unsigned int cpuid_edx(unsigned int op)
return edx;
}
+#ifdef __KERNEL__
#ifdef CONFIG_SMP
void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
@@ -343,6 +344,7 @@ static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
return wrmsr_safe(msr_no, l, h);
}
#endif /* CONFIG_SMP */
+#endif /* __KERNEL__ */
#endif /* __ASSEMBLY__ */
#endif /* !__i386__ */
--
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