From 917538e212a2c080af95ccb4376c5387fac08176 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Tue, 6 Feb 2018 15:36:44 -0800 Subject: kasan: clean up KASAN_SHADOW_SCALE_SHIFT usage Right now the fact that KASAN uses a single shadow byte for 8 bytes of memory is scattered all over the code. This change defines KASAN_SHADOW_SCALE_SHIFT early in asm include files and makes use of this constant where necessary. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/34937ca3b90736eaad91b568edf5684091f662e3.1515775666.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Acked-by: Andrey Ryabinin Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/include/asm/kasan.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'arch/x86/include/asm/kasan.h') diff --git a/arch/x86/include/asm/kasan.h b/arch/x86/include/asm/kasan.h index b577dd0916aa..13e70da38bed 100644 --- a/arch/x86/include/asm/kasan.h +++ b/arch/x86/include/asm/kasan.h @@ -4,6 +4,7 @@ #include #define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL) +#define KASAN_SHADOW_SCALE_SHIFT 3 /* * Compiler uses shadow offset assuming that addresses start @@ -12,12 +13,15 @@ * 'kernel address space start' >> KASAN_SHADOW_SCALE_SHIFT */ #define KASAN_SHADOW_START (KASAN_SHADOW_OFFSET + \ - ((-1UL << __VIRTUAL_MASK_SHIFT) >> 3)) + ((-1UL << __VIRTUAL_MASK_SHIFT) >> \ + KASAN_SHADOW_SCALE_SHIFT)) /* - * 47 bits for kernel address -> (47 - 3) bits for shadow - * 56 bits for kernel address -> (56 - 3) bits for shadow + * 47 bits for kernel address -> (47 - KASAN_SHADOW_SCALE_SHIFT) bits for shadow + * 56 bits for kernel address -> (56 - KASAN_SHADOW_SCALE_SHIFT) bits for shadow */ -#define KASAN_SHADOW_END (KASAN_SHADOW_START + (1ULL << (__VIRTUAL_MASK_SHIFT - 3))) +#define KASAN_SHADOW_END (KASAN_SHADOW_START + \ + (1ULL << (__VIRTUAL_MASK_SHIFT - \ + KASAN_SHADOW_SCALE_SHIFT))) #ifndef __ASSEMBLY__ -- cgit