Re: [PATCH v7 11/11] arm64: mm: Display guarded pages in ptdump

Kees Cook
2020-02-26T21:38:59Z

On Wed, Feb 26, 2020 at 03:57:14PM +0000, Mark Brown wrote:
> v8.5-BTI introduces the GP field in stage 1 translation tables which
> indicates that blocks and pages with it set are guarded pages for which
> branch target identification checks should be performed. Decode this
> when dumping the page tables to aid debugging.
>
> Signed-off-by: Mark Brown <broonie@kernel.org>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
> arch/arm64/mm/dump.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
> index 860c00ec8bd3..78163b7a7dde 100644
> --- a/arch/arm64/mm/dump.c
> +++ b/arch/arm64/mm/dump.c
> @@ -145,6 +145,11 @@ static const struct prot_bits pte_bits[] = {
> .val = PTE_UXN,
> .set = "UXN",
> .clear = " ",
> + }, {
> + .mask = PTE_GP,
> + .val = PTE_GP,
> + .set = "GP",
> + .clear = " ",
> }, {
> .mask = PTE_ATTRINDX_MASK,
> .val = PTE_ATTRINDX(MT_DEVICE_nGnRnE),
> --
> 2.20.1
>

--
Kees Cook