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authorDaniel Axtens <dja@axtens.net>2019-11-30 17:54:57 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-12-01 12:59:05 -0800
commiteafb149ed73a8bb8359c0ce027b98acd4e95b070 (patch)
tree802baca4c0db333693b9104f690938e9d4097de7 /arch/Kconfig
parent06513916930125cdb4d0662f8b675d719abe7f32 (diff)
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fork: support VMAP_STACK with KASAN_VMALLOC
Supporting VMAP_STACK with KASAN_VMALLOC is straightforward: - clear the shadow region of vmapped stacks when swapping them in - tweak Kconfig to allow VMAP_STACK to be turned on with KASAN Link: http://lkml.kernel.org/r/20191031093909.9228-4-dja@axtens.net Signed-off-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/Kconfig')
-rw-r--r--arch/Kconfig9
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index 17c42bc36321..ec07f9ba1152 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -843,16 +843,17 @@ config HAVE_ARCH_VMAP_STACK
config VMAP_STACK
default y
bool "Use a virtually-mapped stack"
- depends on HAVE_ARCH_VMAP_STACK && !KASAN
+ depends on HAVE_ARCH_VMAP_STACK
+ depends on !KASAN || 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.
- This is presently incompatible with KASAN because KASAN expects
- the stack to map directly to the KASAN shadow map using a formula
- that is incorrect if the stack is in vmalloc space.
+ To use this with KASAN, 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