Messages in this thread | | | Subject | Re: [PATCH v2 07/11] arm64: Add skeleton to harden the branch predictor against aliasing attacks | From | Yisheng Xie <> | Date | Thu, 18 Jan 2018 16:37:17 +0800 |
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Hi Will,
On 2018/1/17 18:07, Will Deacon wrote: > On Wed, Jan 17, 2018 at 12:10:33PM +0800, Yisheng Xie wrote: >> Hi Will, >> >> On 2018/1/5 21:12, Will Deacon wrote: >>> diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c >>> index 5f7097d0cd12..d99b36555a16 100644 >>> --- a/arch/arm64/mm/context.c >>> +++ b/arch/arm64/mm/context.c >>> @@ -246,6 +246,8 @@ asmlinkage void post_ttbr_update_workaround(void) >>> "ic iallu; dsb nsh; isb", >>> ARM64_WORKAROUND_CAVIUM_27456, >>> CONFIG_CAVIUM_ERRATUM_27456)); >>> + >>> + arm64_apply_bp_hardening(); >>> } >> >> post_ttbr_update_workaround was used for fix Cavium erratum 2745? so does that >> means, if we do not have this erratum, we do not need arm64_apply_bp_hardening()? >> when mm_swtich and kernel_exit? >> >> From the code logical, it seems not only related to erratum 2745 anymore? >> should it be renamed? > > post_ttbr_update_workaround just runs code after a TTBR update, which > includes mitigations against variant 2 of "spectre" and also a workaround > for a Cavium erratum. These are separate issues.
Get it, Thanks for your kind explain.
Thanks Yisheng > > Will > > . >
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