From: Zachary Amsden Date: Thu, 23 Jun 2011 16:35:23 +0000 (-0300) Subject: KVM: Fix register corruption in pvclock_scale_delta X-Git-Tag: v2.6.39.3~4 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a6e5fedf94a24caa2bd80dd83a81d245b1b895b4;p=karo-tx-linux.git KVM: Fix register corruption in pvclock_scale_delta (cherry picked from commit de2d1a524e94a79078d9fe22c57c0c6009237547) The 128-bit multiply in pvclock.h was missing an output constraint for EDX which caused a register corruption to appear. Thanks to Ulrich for diagnosing the EDX corruption and Avi for providing this fix. Signed-off-by: Zachary Amsden Signed-off-by: Avi Kivity Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h index 31d84acc1512..a518c0a45044 100644 --- a/arch/x86/include/asm/pvclock.h +++ b/arch/x86/include/asm/pvclock.h @@ -22,6 +22,8 @@ static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift) u64 product; #ifdef __i386__ u32 tmp1, tmp2; +#else + ulong tmp; #endif if (shift < 0) @@ -42,8 +44,11 @@ static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift) : "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) ); #elif defined(__x86_64__) __asm__ ( - "mul %%rdx ; shrd $32,%%rdx,%%rax" - : "=a" (product) : "0" (delta), "d" ((u64)mul_frac) ); + "mul %[mul_frac] ; shrd $32, %[hi], %[lo]" + : [lo]"=a"(product), + [hi]"=d"(tmp) + : "0"(delta), + [mul_frac]"rm"((u64)mul_frac)); #else #error implement me! #endif