[PATCH mm v3 05/19] kasan: allow VMAP_STACK for HW_TAGS mode

From: Andrey Konovalov
Date: Fri Nov 13 2020 - 17:22:19 EST


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>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Link: https://linux-review.googlesource.com/id/I3552cbc12321dec82cd7372676e9372a2eb452ac
---
arch/Kconfig | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index 9ebdab3d0ca2..546869c3269d 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -921,16 +921,16 @@ 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
--
2.29.2.299.gdc1121823c-goog