/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __ASM_KASAN_H #define __ASM_KASAN_H #include <asm/pgtable.h> #ifdef CONFIG_KASAN #define KASAN_SHADOW_SCALE_SHIFT 3 #define KASAN_SHADOW_SIZE \ (_AC(1, UL) << (_REGION1_SHIFT - KASAN_SHADOW_SCALE_SHIFT)) #define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL) #define KASAN_SHADOW_START KASAN_SHADOW_OFFSET #define KASAN_SHADOW_END (KASAN_SHADOW_START + KASAN_SHADOW_SIZE) extern void kasan_early_init(void); extern void kasan_copy_shadow_mapping(void); extern void kasan_free_early_identity(void); /* * Estimate kasan memory requirements, which it will reserve * at the very end of available physical memory. To estimate * that, we take into account that kasan would require * 1/8 of available physical memory (for shadow memory) + * creating page tables for the whole memory + shadow memory * region (1 + 1/8). To keep page tables estimates simple take * the double of combined ptes size. * * physmem parameter has to be already adjusted if not entire physical memory * would be used (e.g. due to effect of "mem=" option). */ static inline unsigned long kasan_estimate_memory_needs(unsigned long physmem) { unsigned long kasan_needs; unsigned long pages; /* for shadow memory */ kasan_needs = round_up(physmem / 8, PAGE_SIZE); /* for paging structures */ pages = DIV_ROUND_UP(physmem + kasan_needs, PAGE_SIZE); kasan_needs += DIV_ROUND_UP(pages, _PAGE_ENTRIES) * _PAGE_TABLE_SIZE * 2; return kasan_needs; } #else static inline void kasan_early_init(void) { } static inline void kasan_copy_shadow_mapping(void) { } static inline void kasan_free_early_identity(void) { } static inline unsigned long kasan_estimate_memory_needs(unsigned long physmem) { return 0; } #endif #endif