On Fri, Feb 23, 2018 at 06:29:02PM +0000, Ard Biesheuvel wrote:
> Stable backport commit 173358a49173 ("arm64: kpti: Add ->enable callback
> to remap swapper using nG mappings") of upstream commit f992b4dfd58b did
> not survive the backporting process unscathed, and ends up writing garbage
> into the TTBR1_EL1 register, rather than pointing it to the zero page to
> disable translations. Fix that.
>
> Cc: <stable@xxxxxxxxxxxxxxx> #v4.14
> Reported-by: Nicolas Dechesne <nicolas.dechesne@xxxxxxxxxx>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> ---
> arch/arm64/mm/proc.S | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Any reason why you didn't cc: the stable list, as this is a patch that
is not needed in mainline, right?
> diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
> index 08572f95bd8a..2b473ddeb7a3 100644
> --- a/arch/arm64/mm/proc.S
> +++ b/arch/arm64/mm/proc.S
> @@ -155,7 +155,7 @@ ENDPROC(cpu_do_switch_mm)
>
> .macro __idmap_cpu_set_reserved_ttbr1, tmp1, tmp2
> adrp \tmp1, empty_zero_page
> - msr ttbr1_el1, \tmp2
> + msr ttbr1_el1, \tmp1
I don't understand why this isn't also needed in Linus's tree. What
commit there prevents this from being required?
thanks,
greg k-h