From 9b04c764af18a1dab6d48ca0671f70cdcccf90a2 Mon Sep 17 00:00:00 2001 From: Qing Zhang Date: Wed, 6 Sep 2023 22:54:16 +0800 Subject: [PATCH] kasan: Add __HAVE_ARCH_SHADOW_MAP to support arch specific mapping MIPS, LoongArch and some other architectures have many holes between different segments and the valid address space (256T available) is insufficient to map all these segments to kasan shadow memory with the common formula provided by kasan core. So we need architecture specific mapping formulas to ensure different segments are mapped individually, and only limited space lengths of those specific segments are mapped to shadow. Therefore, when the incoming address is converted to a shadow, we need to add a condition to determine whether it is valid. Reviewed-by: Andrey Konovalov Signed-off-by: Qing Zhang Signed-off-by: Huacai Chen --- include/linux/kasan.h | 2 ++ mm/kasan/kasan.h | 6 ++++++ 2 files changed, 8 insertions(+) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 819b6bc..3df5499 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -54,11 +54,13 @@ extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D]; int kasan_populate_early_shadow(const void *shadow_start, const void *shadow_end); +#ifndef __HAVE_ARCH_SHADOW_MAP static inline void *kasan_mem_to_shadow(const void *addr) { return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET; } +#endif int kasan_add_zero_shadow(void *start, unsigned long size); void kasan_remove_zero_shadow(void *start, unsigned long size); diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 2e973b3..f70e3d7 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -291,16 +291,22 @@ struct kasan_stack_ring { #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) +#ifndef __HAVE_ARCH_SHADOW_MAP static inline const void *kasan_shadow_to_mem(const void *shadow_addr) { return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT); } +#endif static __always_inline bool addr_has_metadata(const void *addr) { +#ifdef __HAVE_ARCH_SHADOW_MAP + return (kasan_mem_to_shadow((void *)addr) != NULL); +#else return (kasan_reset_tag(addr) >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START)); +#endif } /** -- 2.7.4