On Tue, Nov 10, 2020 at 11:11 PM Andrey Konovalov <andreyk...@google.com> wrote: > > 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. > > Signed-off-by: Andrey Konovalov <andreyk...@google.com> > Signed-off-by: Vincenzo Frascino <vincenzo.frasc...@arm.com> > Reviewed-by: Marco Elver <el...@google.com> Reviewed-by: Alexander Potapenko <gli...@google.com>
> --- > Change-Id: Iac733e2248aa9d29f6fc425d8946ba07cca73ecf > --- > 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(-) > > diff --git a/Documentation/dev-tools/kasan.rst > b/Documentation/dev-tools/kasan.rst > index 2b68addaadcd..edca4be5e405 100644 > --- a/Documentation/dev-tools/kasan.rst > +++ b/Documentation/dev-tools/kasan.rst > @@ -264,7 +264,7 @@ Most mappings in vmalloc space are small, requiring less > than a full > 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 > diff --git a/lib/test_kasan.c b/lib/test_kasan.c > index 662f862702fc..2947274cc2d3 100644 > --- a/lib/test_kasan.c > +++ b/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 > diff --git a/lib/test_kasan_module.c b/lib/test_kasan_module.c > index 2d68db6ae67b..fcb991c3aaf8 100644 > --- a/lib/test_kasan_module.c > +++ b/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) > { > diff --git a/mm/kasan/common.c b/mm/kasan/common.c > index a4b73fa0dd7e..f65c9f792f8f 100644 > --- a/mm/kasan/common.c > +++ b/mm/kasan/common.c > @@ -106,7 +106,7 @@ void *memcpy(void *dest, const void *src, size_t len) > > /* > * 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 kasan_poison_memory(const void *address, size_t size, u8 value) > { > @@ -138,13 +138,13 @@ void kasan_unpoison_memory(const void *address, size_t > size) > > kasan_poison_memory(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; > } > } > > @@ -296,7 +296,7 @@ void kasan_unpoison_object_data(struct kmem_cache *cache, > void *object) > void kasan_poison_object_data(struct kmem_cache *cache, void *object) > { > kasan_poison_memory(object, > - round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE), > + round_up(cache->object_size, KASAN_GRANULE_SIZE), > KASAN_KMALLOC_REDZONE); > } > > @@ -368,7 +368,7 @@ static inline bool shadow_invalid(u8 tag, s8 shadow_byte) > { > 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) > @@ -407,7 +407,7 @@ static bool __kasan_slab_free(struct kmem_cache *cache, > void *object, > 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); > kasan_poison_memory(object, rounded_up_size, KASAN_KMALLOC_FREE); > > if ((IS_ENABLED(CONFIG_KASAN_GENERIC) && !quarantine) || > @@ -440,9 +440,9 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, > const void *object, > 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); > @@ -486,7 +486,7 @@ void * __must_check kasan_kmalloc_large(const void *ptr, > size_t size, > > 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); > > kasan_unpoison_memory(ptr, size); > @@ -584,8 +584,8 @@ static int __meminit kasan_mem_notifier(struct > notifier_block *nb, > 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) { > @@ -743,7 +743,7 @@ void kasan_poison_vmalloc(const void *start, unsigned > long size) > if (!is_vmalloc_or_module_addr(start)) > return; > > - size = round_up(size, KASAN_SHADOW_SCALE_SIZE); > + size = round_up(size, KASAN_GRANULE_SIZE); > kasan_poison_memory(start, size, KASAN_VMALLOC_INVALID); > } > > @@ -856,22 +856,22 @@ void kasan_release_vmalloc(unsigned long start, > unsigned long end, > 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); > @@ -897,7 +897,8 @@ int kasan_module_alloc(void *addr, size_t 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))) > diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c > index 7006157c674b..ec4417156943 100644 > --- a/mm/kasan/generic.c > +++ b/mm/kasan/generic.c > @@ -46,7 +46,7 @@ static __always_inline bool memory_is_poisoned_1(unsigned > long addr) > 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_poisoned_2_4_8(unsigned long addr, > * 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_poisoned_16(unsigned > long addr) > 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_poisoned_n(unsigned > long addr, > 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_cache *cache) > > 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); > > kasan_unpoison_memory(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); > diff --git a/mm/kasan/generic_report.c b/mm/kasan/generic_report.c > index 6bb3f66992df..7d5b9e5c7cfe 100644 > --- a/mm/kasan/generic_report.c > +++ b/mm/kasan/generic_report.c > @@ -34,7 +34,7 @@ void *find_first_bad_addr(void *addr, size_t size) > 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(struct > kasan_access_info *info) > 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. > diff --git a/mm/kasan/init.c b/mm/kasan/init.c > index 9ce8cc5b8621..dfddd6c39fe6 100644 > --- a/mm/kasan/init.c > +++ b/mm/kasan/init.c > @@ -442,8 +442,8 @@ void kasan_remove_zero_shadow(void *start, unsigned long > size) > 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, unsigned long size) > 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); > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h > index 03450d3b31f7..c31e2c739301 100644 > --- a/mm/kasan/kasan.h > +++ b/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 */ > diff --git a/mm/kasan/report.c b/mm/kasan/report.c > index d500923abc8b..7b8dcb799a78 100644 > --- a/mm/kasan/report.c > +++ b/mm/kasan/report.c > @@ -314,24 +314,24 @@ static bool __must_check > get_address_stack_frame_info(const void *addr, > 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 long addr) > 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 > diff --git a/mm/kasan/tags_report.c b/mm/kasan/tags_report.c > index 5f183501b871..c87d5a343b4e 100644 > --- a/mm/kasan/tags_report.c > +++ b/mm/kasan/tags_report.c > @@ -76,7 +76,7 @@ void *find_first_bad_addr(void *addr, size_t size) > 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; > } > > -- > 2.29.2.222.g5d2a92d10f8-goog > -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg