Messages in this thread Patch in this message | | | From | Andy Lutomirski <> | Subject | [PATCH v2 2/2] x86/msr: Set the return value to zero when native_rdmsr_safe fails | Date | Sun, 20 Sep 2015 17:02:56 -0700 |
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This will cause unchecked native_rdmsr_safe failures to return deterministic results.
Signed-off-by: Andy Lutomirski <luto@kernel.org> --- arch/x86/include/asm/msr.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index 77d8b284e4a7..9eda52205d42 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -73,7 +73,10 @@ static inline unsigned long long native_read_msr_safe(unsigned int msr, asm volatile("2: rdmsr ; xor %[err],%[err]\n" "1:\n\t" ".section .fixup,\"ax\"\n\t" - "3: mov %[fault],%[err] ; jmp 1b\n\t" + "3: mov %[fault],%[err]\n\t" + "xorl %%eax, %%eax\n\t" + "xorl %%edx, %%edx\n\t" + "jmp 1b\n\t" ".previous\n\t" _ASM_EXTABLE(2b, 3b) : [err] "=r" (*err), EAX_EDX_RET(val, low, high) -- 2.4.3
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