diff options
Diffstat (limited to 'arch/arm64/include/asm/memory.h')
| -rw-r--r-- | arch/arm64/include/asm/memory.h | 43 |
1 files changed, 34 insertions, 9 deletions
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 0385752bd079..2bb8721da7ef 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -74,13 +74,11 @@ #endif /* - * KASAN requires 1/8th of the kernel virtual address space for the shadow - * region. KASAN can bloat the stack significantly, so double the (minimum) - * stack size when KASAN is in use, and then double it again if KASAN_EXTRA is - * on. + * Generic and tag-based KASAN require 1/8th and 1/16th of the kernel virtual + * address space for the shadow region respectively. They can bloat the stack + * significantly, so double the (minimum) stack size when they are in use. */ #ifdef CONFIG_KASAN -#define KASAN_SHADOW_SCALE_SHIFT 3 #define KASAN_SHADOW_SIZE (UL(1) << (VA_BITS - KASAN_SHADOW_SCALE_SHIFT)) #ifdef CONFIG_KASAN_EXTRA #define KASAN_THREAD_SHIFT 2 @@ -221,6 +219,26 @@ extern u64 vabits_user; #define PHYS_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT) /* + * When dealing with data aborts, watchpoints, or instruction traps we may end + * up with a tagged userland pointer. Clear the tag to get a sane pointer to + * pass on to access_ok(), for instance. + */ +#define untagged_addr(addr) \ + ((__typeof__(addr))sign_extend64((u64)(addr), 55)) + +#ifdef CONFIG_KASAN_SW_TAGS +#define __tag_shifted(tag) ((u64)(tag) << 56) +#define __tag_set(addr, tag) (__typeof__(addr))( \ + ((u64)(addr) & ~__tag_shifted(0xff)) | __tag_shifted(tag)) +#define __tag_reset(addr) untagged_addr(addr) +#define __tag_get(addr) (__u8)((u64)(addr) >> 56) +#else +#define __tag_set(addr, tag) (addr) +#define __tag_reset(addr) (addr) +#define __tag_get(addr) 0 +#endif + +/* * Physical vs virtual RAM address space conversion. These are * private definitions which should NOT be used outside memory.h * files. Use virt_to_phys/phys_to_virt/__pa/__va instead. @@ -303,7 +321,13 @@ static inline void *phys_to_virt(phys_addr_t x) #define __virt_to_pgoff(kaddr) (((u64)(kaddr) & ~PAGE_OFFSET) / PAGE_SIZE * sizeof(struct page)) #define __page_to_voff(kaddr) (((u64)(kaddr) & ~VMEMMAP_START) * PAGE_SIZE / sizeof(struct page)) -#define page_to_virt(page) ((void *)((__page_to_voff(page)) | PAGE_OFFSET)) +#define page_to_virt(page) ({ \ + unsigned long __addr = \ + ((__page_to_voff(page)) | PAGE_OFFSET); \ + __addr = __tag_set(__addr, page_kasan_tag(page)); \ + ((void *)__addr); \ +}) + #define virt_to_page(vaddr) ((struct page *)((__virt_to_pgoff(vaddr)) | VMEMMAP_START)) #define _virt_addr_valid(kaddr) pfn_valid((((u64)(kaddr) & ~PAGE_OFFSET) \ @@ -311,9 +335,10 @@ static inline void *phys_to_virt(phys_addr_t x) #endif #endif -#define _virt_addr_is_linear(kaddr) (((u64)(kaddr)) >= PAGE_OFFSET) -#define virt_addr_valid(kaddr) (_virt_addr_is_linear(kaddr) && \ - _virt_addr_valid(kaddr)) +#define _virt_addr_is_linear(kaddr) \ + (__tag_reset((u64)(kaddr)) >= PAGE_OFFSET) +#define virt_addr_valid(kaddr) \ + (_virt_addr_is_linear(kaddr) && _virt_addr_valid(kaddr)) #include <asm-generic/memory_model.h> |