Re: [PATCH v2 05/20] kasan: allow VMAP_STACK for HW_TAGS mode

From: Marco Elver
Date: Wed Nov 11 2020 - 11:21:01 EST


On Tue, Nov 10, 2020 at 11:20PM +0100, Andrey Konovalov wrote:
> Even though hardware tag-based mode currently doesn't support checking
> vmalloc allocations, it doesn't use shadow memory and works with
> VMAP_STACK as is. Change VMAP_STACK definition accordingly.
>
> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> Link: https://linux-review.googlesource.com/id/I3552cbc12321dec82cd7372676e9372a2eb452ac
> ---

Shouldn't this be in the other series?

FWIW,

Reviewed-by: Marco Elver <elver@xxxxxxxxxx>

> arch/Kconfig | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/Kconfig b/arch/Kconfig
> index 56b6ccc0e32d..7e7d14fae568 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -914,16 +914,16 @@ config VMAP_STACK
> default y
> bool "Use a virtually-mapped stack"
> depends on HAVE_ARCH_VMAP_STACK
> - depends on !KASAN || KASAN_VMALLOC
> + depends on !KASAN || KASAN_HW_TAGS || KASAN_VMALLOC
> help
> Enable this if you want the use virtually-mapped kernel stacks
> with guard pages. This causes kernel stack overflows to be
> caught immediately rather than causing difficult-to-diagnose
> corruption.
>
> - To use this with KASAN, the architecture must support backing
> - virtual mappings with real shadow memory, and KASAN_VMALLOC must
> - be enabled.
> + To use this with software KASAN modes, the architecture must support
> + backing virtual mappings with real shadow memory, and KASAN_VMALLOC
> + must be enabled.
>
> config ARCH_OPTIONAL_KERNEL_RWX
> def_bool n
> --
> 2.29.2.222.g5d2a92d10f8-goog
>