From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan: rename KASAN_SHADOW_* to KASAN_GRANULE_* This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. The new mode won't be using shadow memory, but will still use the concept of memory granules. Each memory granule maps to a single metadata entry: 8 bytes per one shadow byte for generic mode, 16 bytes per one shadow byte for software tag-based mode, and 16 bytes per one allocation tag for hardware tag-based mode. Rename KASAN_SHADOW_SCALE_SIZE to KASAN_GRANULE_SIZE, and KASAN_SHADOW_MASK to KASAN_GRANULE_MASK. Also use MASK when used as a mask, otherwise use SIZE. No functional changes. Link: https://lkml.kernel.org/r/939b5754e47f528a6e6a6f28ffc5815d8d128033.1606161801.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx> Tested-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx> Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/dev-tools/kasan.rst | 2 - lib/test_kasan.c | 2 - lib/test_kasan_module.c | 2 - mm/kasan/common.c | 39 ++++++++++++++-------------- mm/kasan/generic.c | 14 +++++----- mm/kasan/generic_report.c | 8 ++--- mm/kasan/init.c | 8 ++--- mm/kasan/kasan.h | 4 +- mm/kasan/report.c | 10 +++---- mm/kasan/tags_report.c | 2 - 10 files changed, 46 insertions(+), 45 deletions(-) --- a/Documentation/dev-tools/kasan.rst~kasan-rename-kasan_shadow_-to-kasan_granule_ +++ a/Documentation/dev-tools/kasan.rst @@ -265,7 +265,7 @@ Most mappings in vmalloc space are small page of shadow space. Allocating a full shadow page per mapping would therefore be wasteful. Furthermore, to ensure that different mappings use different shadow pages, mappings would have to be aligned to -``KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE``. +``KASAN_GRANULE_SIZE * PAGE_SIZE``. Instead, we share backing space across multiple mappings. We allocate a backing page when a mapping in vmalloc space uses a particular page --- a/lib/test_kasan.c~kasan-rename-kasan_shadow_-to-kasan_granule_ +++ a/lib/test_kasan.c @@ -25,7 +25,7 @@ #include "../mm/kasan/kasan.h" -#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_SHADOW_SCALE_SIZE) +#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE) /* * We assign some test results to these globals to make sure the tests --- a/lib/test_kasan_module.c~kasan-rename-kasan_shadow_-to-kasan_granule_ +++ a/lib/test_kasan_module.c @@ -15,7 +15,7 @@ #include "../mm/kasan/kasan.h" -#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_SHADOW_SCALE_SIZE) +#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE) static noinline void __init copy_user_test(void) { --- a/mm/kasan/common.c~kasan-rename-kasan_shadow_-to-kasan_granule_ +++ a/mm/kasan/common.c @@ -106,7 +106,7 @@ void *memcpy(void *dest, const void *src /* * Poisons the shadow memory for 'size' bytes starting from 'addr'. - * Memory addresses should be aligned to KASAN_SHADOW_SCALE_SIZE. + * Memory addresses should be aligned to KASAN_GRANULE_SIZE. */ void poison_range(const void *address, size_t size, u8 value) { @@ -138,13 +138,13 @@ void unpoison_range(const void *address, poison_range(address, size, tag); - if (size & KASAN_SHADOW_MASK) { + if (size & KASAN_GRANULE_MASK) { u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size); if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) *shadow = tag; else - *shadow = size & KASAN_SHADOW_MASK; + *shadow = size & KASAN_GRANULE_MASK; } } @@ -301,7 +301,7 @@ void kasan_unpoison_object_data(struct k void kasan_poison_object_data(struct kmem_cache *cache, void *object) { poison_range(object, - round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE), + round_up(cache->object_size, KASAN_GRANULE_SIZE), KASAN_KMALLOC_REDZONE); } @@ -373,7 +373,7 @@ static inline bool shadow_invalid(u8 tag { if (IS_ENABLED(CONFIG_KASAN_GENERIC)) return shadow_byte < 0 || - shadow_byte >= KASAN_SHADOW_SCALE_SIZE; + shadow_byte >= KASAN_GRANULE_SIZE; /* else CONFIG_KASAN_SW_TAGS: */ if ((u8)shadow_byte == KASAN_TAG_INVALID) @@ -412,7 +412,7 @@ static bool __kasan_slab_free(struct kme return true; } - rounded_up_size = round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE); + rounded_up_size = round_up(cache->object_size, KASAN_GRANULE_SIZE); poison_range(object, rounded_up_size, KASAN_KMALLOC_FREE); if ((IS_ENABLED(CONFIG_KASAN_GENERIC) && !quarantine) || @@ -445,9 +445,9 @@ static void *__kasan_kmalloc(struct kmem return NULL; redzone_start = round_up((unsigned long)(object + size), - KASAN_SHADOW_SCALE_SIZE); + KASAN_GRANULE_SIZE); redzone_end = round_up((unsigned long)object + cache->object_size, - KASAN_SHADOW_SCALE_SIZE); + KASAN_GRANULE_SIZE); if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) tag = assign_tag(cache, object, false, keep_tag); @@ -491,7 +491,7 @@ void * __must_check kasan_kmalloc_large( page = virt_to_page(ptr); redzone_start = round_up((unsigned long)(ptr + size), - KASAN_SHADOW_SCALE_SIZE); + KASAN_GRANULE_SIZE); redzone_end = (unsigned long)ptr + page_size(page); unpoison_range(ptr, size); @@ -589,8 +589,8 @@ static int __meminit kasan_mem_notifier( shadow_size = nr_shadow_pages << PAGE_SHIFT; shadow_end = shadow_start + shadow_size; - if (WARN_ON(mem_data->nr_pages % KASAN_SHADOW_SCALE_SIZE) || - WARN_ON(start_kaddr % (KASAN_SHADOW_SCALE_SIZE << PAGE_SHIFT))) + if (WARN_ON(mem_data->nr_pages % KASAN_GRANULE_SIZE) || + WARN_ON(start_kaddr % (KASAN_GRANULE_SIZE << PAGE_SHIFT))) return NOTIFY_BAD; switch (action) { @@ -748,7 +748,7 @@ void kasan_poison_vmalloc(const void *st if (!is_vmalloc_or_module_addr(start)) return; - size = round_up(size, KASAN_SHADOW_SCALE_SIZE); + size = round_up(size, KASAN_GRANULE_SIZE); poison_range(start, size, KASAN_VMALLOC_INVALID); } @@ -861,22 +861,22 @@ void kasan_release_vmalloc(unsigned long unsigned long region_start, region_end; unsigned long size; - region_start = ALIGN(start, PAGE_SIZE * KASAN_SHADOW_SCALE_SIZE); - region_end = ALIGN_DOWN(end, PAGE_SIZE * KASAN_SHADOW_SCALE_SIZE); + region_start = ALIGN(start, PAGE_SIZE * KASAN_GRANULE_SIZE); + region_end = ALIGN_DOWN(end, PAGE_SIZE * KASAN_GRANULE_SIZE); free_region_start = ALIGN(free_region_start, - PAGE_SIZE * KASAN_SHADOW_SCALE_SIZE); + PAGE_SIZE * KASAN_GRANULE_SIZE); if (start != region_start && free_region_start < region_start) - region_start -= PAGE_SIZE * KASAN_SHADOW_SCALE_SIZE; + region_start -= PAGE_SIZE * KASAN_GRANULE_SIZE; free_region_end = ALIGN_DOWN(free_region_end, - PAGE_SIZE * KASAN_SHADOW_SCALE_SIZE); + PAGE_SIZE * KASAN_GRANULE_SIZE); if (end != region_end && free_region_end > region_end) - region_end += PAGE_SIZE * KASAN_SHADOW_SCALE_SIZE; + region_end += PAGE_SIZE * KASAN_GRANULE_SIZE; shadow_start = kasan_mem_to_shadow((void *)region_start); shadow_end = kasan_mem_to_shadow((void *)region_end); @@ -902,7 +902,8 @@ int kasan_module_alloc(void *addr, size_ unsigned long shadow_start; shadow_start = (unsigned long)kasan_mem_to_shadow(addr); - scaled_size = (size + KASAN_SHADOW_MASK) >> KASAN_SHADOW_SCALE_SHIFT; + scaled_size = (size + KASAN_GRANULE_SIZE - 1) >> + KASAN_SHADOW_SCALE_SHIFT; shadow_size = round_up(scaled_size, PAGE_SIZE); if (WARN_ON(!PAGE_ALIGNED(shadow_start))) --- a/mm/kasan/generic.c~kasan-rename-kasan_shadow_-to-kasan_granule_ +++ a/mm/kasan/generic.c @@ -46,7 +46,7 @@ static __always_inline bool memory_is_po s8 shadow_value = *(s8 *)kasan_mem_to_shadow((void *)addr); if (unlikely(shadow_value)) { - s8 last_accessible_byte = addr & KASAN_SHADOW_MASK; + s8 last_accessible_byte = addr & KASAN_GRANULE_MASK; return unlikely(last_accessible_byte >= shadow_value); } @@ -62,7 +62,7 @@ static __always_inline bool memory_is_po * Access crosses 8(shadow size)-byte boundary. Such access maps * into 2 shadow bytes, so we need to check them both. */ - if (unlikely(((addr + size - 1) & KASAN_SHADOW_MASK) < size - 1)) + if (unlikely(((addr + size - 1) & KASAN_GRANULE_MASK) < size - 1)) return *shadow_addr || memory_is_poisoned_1(addr + size - 1); return memory_is_poisoned_1(addr + size - 1); @@ -73,7 +73,7 @@ static __always_inline bool memory_is_po u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr); /* Unaligned 16-bytes access maps into 3 shadow bytes. */ - if (unlikely(!IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE))) + if (unlikely(!IS_ALIGNED(addr, KASAN_GRANULE_SIZE))) return *shadow_addr || memory_is_poisoned_1(addr + 15); return *shadow_addr; @@ -134,7 +134,7 @@ static __always_inline bool memory_is_po s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte); if (unlikely(ret != (unsigned long)last_shadow || - ((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow))) + ((long)(last_byte & KASAN_GRANULE_MASK) >= *last_shadow))) return true; } return false; @@ -200,7 +200,7 @@ void kasan_cache_shutdown(struct kmem_ca static void register_global(struct kasan_global *global) { - size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE); + size_t aligned_size = round_up(global->size, KASAN_GRANULE_SIZE); unpoison_range(global->beg, global->size); @@ -274,10 +274,10 @@ EXPORT_SYMBOL(__asan_handle_no_return); /* Emitted by compiler to poison alloca()ed objects. */ void __asan_alloca_poison(unsigned long addr, size_t size) { - size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE); + size_t rounded_up_size = round_up(size, KASAN_GRANULE_SIZE); size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) - rounded_up_size; - size_t rounded_down_size = round_down(size, KASAN_SHADOW_SCALE_SIZE); + size_t rounded_down_size = round_down(size, KASAN_GRANULE_SIZE); const void *left_redzone = (const void *)(addr - KASAN_ALLOCA_REDZONE_SIZE); --- a/mm/kasan/generic_report.c~kasan-rename-kasan_shadow_-to-kasan_granule_ +++ a/mm/kasan/generic_report.c @@ -34,7 +34,7 @@ void *find_first_bad_addr(void *addr, si void *p = addr; while (p < addr + size && !(*(u8 *)kasan_mem_to_shadow(p))) - p += KASAN_SHADOW_SCALE_SIZE; + p += KASAN_GRANULE_SIZE; return p; } @@ -46,14 +46,14 @@ static const char *get_shadow_bug_type(s shadow_addr = (u8 *)kasan_mem_to_shadow(info->first_bad_addr); /* - * If shadow byte value is in [0, KASAN_SHADOW_SCALE_SIZE) we can look + * If shadow byte value is in [0, KASAN_GRANULE_SIZE) we can look * at the next shadow byte to determine the type of the bad access. */ - if (*shadow_addr > 0 && *shadow_addr <= KASAN_SHADOW_SCALE_SIZE - 1) + if (*shadow_addr > 0 && *shadow_addr <= KASAN_GRANULE_SIZE - 1) shadow_addr++; switch (*shadow_addr) { - case 0 ... KASAN_SHADOW_SCALE_SIZE - 1: + case 0 ... KASAN_GRANULE_SIZE - 1: /* * In theory it's still possible to see these shadow values * due to a data race in the kernel code. --- a/mm/kasan/init.c~kasan-rename-kasan_shadow_-to-kasan_granule_ +++ a/mm/kasan/init.c @@ -442,8 +442,8 @@ void kasan_remove_zero_shadow(void *star end = addr + (size >> KASAN_SHADOW_SCALE_SHIFT); if (WARN_ON((unsigned long)start % - (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)) || - WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE))) + (KASAN_GRANULE_SIZE * PAGE_SIZE)) || + WARN_ON(size % (KASAN_GRANULE_SIZE * PAGE_SIZE))) return; for (; addr < end; addr = next) { @@ -477,8 +477,8 @@ int kasan_add_zero_shadow(void *start, u shadow_end = shadow_start + (size >> KASAN_SHADOW_SCALE_SHIFT); if (WARN_ON((unsigned long)start % - (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)) || - WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE))) + (KASAN_GRANULE_SIZE * PAGE_SIZE)) || + WARN_ON(size % (KASAN_GRANULE_SIZE * PAGE_SIZE))) return -EINVAL; ret = kasan_populate_early_shadow(shadow_start, shadow_end); --- a/mm/kasan/kasan.h~kasan-rename-kasan_shadow_-to-kasan_granule_ +++ a/mm/kasan/kasan.h @@ -5,8 +5,8 @@ #include <linux/kasan.h> #include <linux/stackdepot.h> -#define KASAN_SHADOW_SCALE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT) -#define KASAN_SHADOW_MASK (KASAN_SHADOW_SCALE_SIZE - 1) +#define KASAN_GRANULE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT) +#define KASAN_GRANULE_MASK (KASAN_GRANULE_SIZE - 1) #define KASAN_TAG_KERNEL 0xFF /* native kernel pointers tag */ #define KASAN_TAG_INVALID 0xFE /* inaccessible memory tag */ --- a/mm/kasan/report.c~kasan-rename-kasan_shadow_-to-kasan_granule_ +++ a/mm/kasan/report.c @@ -314,24 +314,24 @@ static bool __must_check get_address_sta return false; aligned_addr = round_down((unsigned long)addr, sizeof(long)); - mem_ptr = round_down(aligned_addr, KASAN_SHADOW_SCALE_SIZE); + mem_ptr = round_down(aligned_addr, KASAN_GRANULE_SIZE); shadow_ptr = kasan_mem_to_shadow((void *)aligned_addr); shadow_bottom = kasan_mem_to_shadow(end_of_stack(current)); while (shadow_ptr >= shadow_bottom && *shadow_ptr != KASAN_STACK_LEFT) { shadow_ptr--; - mem_ptr -= KASAN_SHADOW_SCALE_SIZE; + mem_ptr -= KASAN_GRANULE_SIZE; } while (shadow_ptr >= shadow_bottom && *shadow_ptr == KASAN_STACK_LEFT) { shadow_ptr--; - mem_ptr -= KASAN_SHADOW_SCALE_SIZE; + mem_ptr -= KASAN_GRANULE_SIZE; } if (shadow_ptr < shadow_bottom) return false; - frame = (const unsigned long *)(mem_ptr + KASAN_SHADOW_SCALE_SIZE); + frame = (const unsigned long *)(mem_ptr + KASAN_GRANULE_SIZE); if (frame[0] != KASAN_CURRENT_STACK_FRAME_MAGIC) { pr_err("KASAN internal error: frame info validation failed; invalid marker: %lu\n", frame[0]); @@ -599,6 +599,6 @@ void kasan_non_canonical_hook(unsigned l else bug_type = "maybe wild-memory-access"; pr_alert("KASAN: %s in range [0x%016lx-0x%016lx]\n", bug_type, - orig_addr, orig_addr + KASAN_SHADOW_MASK); + orig_addr, orig_addr + KASAN_GRANULE_SIZE - 1); } #endif --- a/mm/kasan/tags_report.c~kasan-rename-kasan_shadow_-to-kasan_granule_ +++ a/mm/kasan/tags_report.c @@ -76,7 +76,7 @@ void *find_first_bad_addr(void *addr, si void *end = p + size; while (p < end && tag == *(u8 *)kasan_mem_to_shadow(p)) - p += KASAN_SHADOW_SCALE_SIZE; + p += KASAN_GRANULE_SIZE; return p; } _
