On Mon, Aug 05, 2019 at 06:14:10PM +0100, Will Deacon wrote:
> commit 147b9635e6347104b91f48ca9dca61eb0fbf2a54 upstream.
>
> If CTR_EL0.{CWG,ERG} are 0b0000 then they must be interpreted to have
> their architecturally maximum values, which defeats the use of
> FTR_HIGHER_SAFE when sanitising CPU ID registers on heterogeneous
> machines.
>
> Introduce FTR_HIGHER_OR_ZERO_SAFE so that these fields effectively
> saturate at zero.
>
> Fixes: 3c739b571084 ("arm64: Keep track of CPU feature registers")
> Cc: <stable@xxxxxxxxxxxxxxx> # 4.14.y only
> Reviewed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
> Signed-off-by: Will Deacon <will@xxxxxxxxxx>
> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
> ---
>
> Backport for 4.14.y -stable kernel, after original failed to apply:
Now queued up, thanks.
greg k-h
