Re: [tip:x86/pti] x86/retpoline: Fill return stack buffer on vmexit

From: Borislav Petkov
Date: Thu Jan 25 2018 - 14:11:02 EST


On Thu, Jan 25, 2018 at 08:07:29PM +0100, Borislav Petkov wrote:
> static inline void vmexit_fill_RSB(void)
> {
> #ifdef CONFIG_RETPOLINE
> alternative_input("", "call __fill_rsb_clobber_ax", X86_FEATURE_RETPOLINE, ASM_NO_INPUT_CLOBBER("memory"));

Whoops, forgot the clobbers:

alternative_input("", "call __fill_rsb_clobber_ax", X86_FEATURE_RETPOLINE, ASM_NO_INPUT_CLOBBER(_ASM_AX, "memory"));

--
Regards/Gruss,
Boris.

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