diff options
| author | Zachary Amsden <zamsden@redhat.com> | 2011-06-15 20:50:04 -0700 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-06-19 19:23:14 +0300 |
| commit | de2d1a524e94a79078d9fe22c57c0c6009237547 (patch) | |
| tree | 0f4c747a26aa45b3f670324064284e21ad4cd034 /arch | |
| parent | a0a8eaba1661232f094654422bdabe2df4e26863 (diff) | |
KVM: Fix register corruption in pvclock_scale_delta
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 <zamsden@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/pvclock.h | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h index 31d84acc151..a518c0a4504 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 |