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| author |   Andrey Konovalov <andreyknvl@google.com> | 2018-12-28 00:29:57 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2018-12-28 12:11:43 -0800 |
| commit | b2f557eae9ed0ab2b612ce9ce7e3f06174a83e76 (patch) | |
| tree | d5496a218f24a1963635bd4b478ca17fdd8894f7 /arch/arm64/include/asm/memory.h | |
| parent | kasan: add CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS (diff) | |
| download | linux-dev-b2f557eae9ed0ab2b612ce9ce7e3f06174a83e76.tar.xz linux-dev-b2f557eae9ed0ab2b612ce9ce7e3f06174a83e76.zip | |
kasan, arm64: adjust shadow size for tag-based mode
Tag-based KASAN uses 1 shadow byte for 16 bytes of kernel memory, so it
requires 1/16th of the kernel virtual address space for the shadow memory.
This commit sets KASAN_SHADOW_SCALE_SHIFT to 4 when the tag-based KASAN
mode is enabled.
Link: http://lkml.kernel.org/r/308b6bd49f756bb5e533be93c6f085ba99b30339.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arm64/include/asm/memory.h')
| -rw-r--r-- | arch/arm64/include/asm/memory.h | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 0385752bd079..7640feed268d 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -74,13 +74,11 @@ #endif /* - * KASAN requires 1/8th of the kernel virtual address space for the shadow - * region. KASAN can bloat the stack significantly, so double the (minimum) - * stack size when KASAN is in use, and then double it again if KASAN_EXTRA is - * on. + * Generic and tag-based KASAN require 1/8th and 1/16th of the kernel virtual + * address space for the shadow region respectively. They can bloat the stack + * significantly, so double the (minimum) stack size when they are in use. */ #ifdef CONFIG_KASAN -#define KASAN_SHADOW_SCALE_SHIFT 3 #define KASAN_SHADOW_SIZE (UL(1) << (VA_BITS - KASAN_SHADOW_SCALE_SHIFT)) #ifdef CONFIG_KASAN_EXTRA #define KASAN_THREAD_SHIFT 2 |