xref: /openbmc/linux/arch/riscv/include/asm/kasan.h (revision 0bf49ffb)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Copyright (C) 2019 Andes Technology Corporation */
3 
4 #ifndef __ASM_KASAN_H
5 #define __ASM_KASAN_H
6 
7 #ifndef __ASSEMBLY__
8 
9 #ifdef CONFIG_KASAN
10 
11 /*
12  * The following comment was copied from arm64:
13  * KASAN_SHADOW_START: beginning of the kernel virtual addresses.
14  * KASAN_SHADOW_END: KASAN_SHADOW_START + 1/N of kernel virtual addresses,
15  * where N = (1 << KASAN_SHADOW_SCALE_SHIFT).
16  *
17  * KASAN_SHADOW_OFFSET:
18  * This value is used to map an address to the corresponding shadow
19  * address by the following formula:
20  *     shadow_addr = (address >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET
21  *
22  * (1 << (64 - KASAN_SHADOW_SCALE_SHIFT)) shadow addresses that lie in range
23  * [KASAN_SHADOW_OFFSET, KASAN_SHADOW_END) cover all 64-bits of virtual
24  * addresses. So KASAN_SHADOW_OFFSET should satisfy the following equation:
25  *      KASAN_SHADOW_OFFSET = KASAN_SHADOW_END -
26  *                              (1ULL << (64 - KASAN_SHADOW_SCALE_SHIFT))
27  */
28 #define KASAN_SHADOW_SCALE_SHIFT	3
29 
30 #define KASAN_SHADOW_SIZE	(UL(1) << ((CONFIG_VA_BITS - 1) - KASAN_SHADOW_SCALE_SHIFT))
31 #define KASAN_SHADOW_START	KERN_VIRT_START
32 #define KASAN_SHADOW_END	(KASAN_SHADOW_START + KASAN_SHADOW_SIZE)
33 #define KASAN_SHADOW_OFFSET	(KASAN_SHADOW_END - (1ULL << \
34 					(64 - KASAN_SHADOW_SCALE_SHIFT)))
35 
36 void kasan_init(void);
37 asmlinkage void kasan_early_init(void);
38 
39 #endif
40 #endif
41 #endif /* __ASM_KASAN_H */
42