Re: [PATCH] ARM: spectre-v2: remove Brahma-B53 from hardening

From: Florian Fainelli
Date: Sun Nov 10 2019 - 22:33:13 EST




On 10/31/2019 3:00 PM, Florian Fainelli wrote:
> From: Doug Berger <opendmb@xxxxxxxxx>
>
> When the default processor handling was added to the function
> cpu_v7_spectre_init() it only excluded other ARM implemented processor
> cores. The Broadcom Brahma B53 core is not implemented by ARM so it
> ended up falling through into the set of processors that attempt to use
> the ARM_SMCCC_ARCH_WORKAROUND_1 service to harden the branch predictor.
>
> Since this workaround is not necessary for the Brahma-B53 this commit
> explicitly checks for it and prevents it from applying a branch
> predictor hardening workaround.
>
> Fixes: 10115105cb3a ("ARM: spectre-v2: add firmware based hardening")
> Signed-off-by: Doug Berger <opendmb@xxxxxxxxx>
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>

Submitted:

https://www.armlinux.org.uk/developer/patches/viewpatch.php?id=8937/1
--
Florian