linux-stable/arch/x86/include/asm/kasan.h
Andrey Konovalov 917538e212 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 <andreyknvl@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00

38 lines
1.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_KASAN_H
#define _ASM_X86_KASAN_H
#include <linux/const.h>
#define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
#define KASAN_SHADOW_SCALE_SHIFT 3
/*
* Compiler uses shadow offset assuming that addresses start
* from 0. Kernel addresses don't start from 0, so shadow
* for kernel really starts from compiler's shadow offset +
* 'kernel address space start' >> KASAN_SHADOW_SCALE_SHIFT
*/
#define KASAN_SHADOW_START (KASAN_SHADOW_OFFSET + \
((-1UL << __VIRTUAL_MASK_SHIFT) >> \
KASAN_SHADOW_SCALE_SHIFT))
/*
* 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 - \
KASAN_SHADOW_SCALE_SHIFT)))
#ifndef __ASSEMBLY__
#ifdef CONFIG_KASAN
void __init kasan_early_init(void);
void __init kasan_init(void);
#else
static inline void kasan_early_init(void) { }
static inline void kasan_init(void) { }
#endif
#endif
#endif