[PATCH v2 4/4] powerpc/64s: Sanitise user registers on interrupt in pseries

[Nicholas Piggin]

On Mon Nov 7, 2022 at 1:32 PM AEST, Rohan McLure wrote:
> Cause pseries platforms to default to zeroising all potentially user-defined
> registers when entering the kernel by means of any interrupt source,
> reducing user-influence of the kernel and the likelihood or producing
> speculation gadgets.

For POWERNV as well?

Thanks,
Nick

>
> Signed-off-by: Rohan McLure <rmclure at linux.ibm.com>
> ---
> Resubmitting patches as their own series after v6 partially merged:
> Link: https://lore.kernel.org/all/166488988686.779920.13794870102696416283.b4-ty@ellerman.id.au/t/
> ---
>  arch/powerpc/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 9d3d20c6f365..2eb328b25e49 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -532,7 +532,7 @@ config HOTPLUG_CPU
>  config INTERRUPT_SANITIZE_REGISTERS
>  	bool "Clear gprs on interrupt arrival"
>  	depends on PPC64 && ARCH_HAS_SYSCALL_WRAPPER
> -	default PPC_BOOK3E_64
> +	default PPC_BOOK3E_64 || PPC_PSERIES
>  	help
>  	  Reduce the influence of user register state on interrupt handlers and
>  	  syscalls through clearing user state from registers before handling
> -- 
> 2.34.1