track->stack = kasan_save_stack(flags);
}
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
void kasan_enable_current(void)
{
current->kasan_depth++;
{
current->kasan_depth--;
}
+#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
-void kasan_unpoison_range(const void *address, size_t size)
+void __kasan_unpoison_range(const void *address, size_t size)
{
unpoison_range(address, size);
}
-static void __kasan_unpoison_stack(struct task_struct *task, const void *sp)
-{
- void *base = task_stack_page(task);
- size_t size = sp - base;
-
- unpoison_range(base, size);
-}
-
+#if CONFIG_KASAN_STACK
/* Unpoison the entire stack for a task. */
void kasan_unpoison_task_stack(struct task_struct *task)
{
- __kasan_unpoison_stack(task, task_stack_page(task) + THREAD_SIZE);
+ void *base = task_stack_page(task);
+
+ unpoison_range(base, THREAD_SIZE);
}
/* Unpoison the stack for the current task beyond a watermark sp value. */
unpoison_range(base, watermark - base);
}
+#endif /* CONFIG_KASAN_STACK */
+
+/*
+ * Only allow cache merging when stack collection is disabled and no metadata
+ * is present.
+ */
+slab_flags_t __kasan_never_merge(void)
+{
+ if (kasan_stack_collection_enabled())
+ return SLAB_KASAN;
+ return 0;
+}
-void kasan_alloc_pages(struct page *page, unsigned int order)
+void __kasan_alloc_pages(struct page *page, unsigned int order)
{
u8 tag;
unsigned long i;
unpoison_range(page_address(page), PAGE_SIZE << order);
}
-void kasan_free_pages(struct page *page, unsigned int order)
+void __kasan_free_pages(struct page *page, unsigned int order)
{
if (likely(!PageHighMem(page)))
poison_range(page_address(page),
*/
static inline unsigned int optimal_redzone(unsigned int object_size)
{
- if (IS_ENABLED(CONFIG_KASAN_SW_TAGS))
- return 0;
-
return
object_size <= 64 - 16 ? 16 :
object_size <= 128 - 32 ? 32 :
object_size <= (1 << 16) - 1024 ? 1024 : 2048;
}
-void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
- slab_flags_t *flags)
+void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
+ slab_flags_t *flags)
{
- unsigned int orig_size = *size;
- unsigned int redzone_size;
- int redzone_adjust;
+ unsigned int ok_size;
+ unsigned int optimal_size;
- /* Add alloc meta. */
- cache->kasan_info.alloc_meta_offset = *size;
- *size += sizeof(struct kasan_alloc_meta);
+ /*
+ * SLAB_KASAN is used to mark caches as ones that are sanitized by
+ * KASAN. Currently this flag is used in two places:
+ * 1. In slab_ksize() when calculating the size of the accessible
+ * memory within the object.
+ * 2. In slab_common.c to prevent merging of sanitized caches.
+ */
+ *flags |= SLAB_KASAN;
- /* Add free meta. */
- if (IS_ENABLED(CONFIG_KASAN_GENERIC) &&
- (cache->flags & SLAB_TYPESAFE_BY_RCU || cache->ctor ||
- cache->object_size < sizeof(struct kasan_free_meta))) {
- cache->kasan_info.free_meta_offset = *size;
- *size += sizeof(struct kasan_free_meta);
- }
+ if (!kasan_stack_collection_enabled())
+ return;
- redzone_size = optimal_redzone(cache->object_size);
- redzone_adjust = redzone_size - (*size - cache->object_size);
- if (redzone_adjust > 0)
- *size += redzone_adjust;
+ ok_size = *size;
- *size = min_t(unsigned int, KMALLOC_MAX_SIZE,
- max(*size, cache->object_size + redzone_size));
+ /* Add alloc meta into redzone. */
+ cache->kasan_info.alloc_meta_offset = *size;
+ *size += sizeof(struct kasan_alloc_meta);
/*
- * If the metadata doesn't fit, don't enable KASAN at all.
+ * If alloc meta doesn't fit, don't add it.
+ * This can only happen with SLAB, as it has KMALLOC_MAX_SIZE equal
+ * to KMALLOC_MAX_CACHE_SIZE and doesn't fall back to page_alloc for
+ * larger sizes.
*/
- if (*size <= cache->kasan_info.alloc_meta_offset ||
- *size <= cache->kasan_info.free_meta_offset) {
+ if (*size > KMALLOC_MAX_SIZE) {
cache->kasan_info.alloc_meta_offset = 0;
- cache->kasan_info.free_meta_offset = 0;
- *size = orig_size;
+ *size = ok_size;
+ /* Continue, since free meta might still fit. */
+ }
+
+ /* Only the generic mode uses free meta or flexible redzones. */
+ if (!IS_ENABLED(CONFIG_KASAN_GENERIC)) {
+ cache->kasan_info.free_meta_offset = KASAN_NO_FREE_META;
return;
}
- *flags |= SLAB_KASAN;
+ /*
+ * Add free meta into redzone when it's not possible to store
+ * it in the object. This is the case when:
+ * 1. Object is SLAB_TYPESAFE_BY_RCU, which means that it can
+ * be touched after it was freed, or
+ * 2. Object has a constructor, which means it's expected to
+ * retain its content until the next allocation, or
+ * 3. Object is too small.
+ * Otherwise cache->kasan_info.free_meta_offset = 0 is implied.
+ */
+ if ((cache->flags & SLAB_TYPESAFE_BY_RCU) || cache->ctor ||
+ cache->object_size < sizeof(struct kasan_free_meta)) {
+ ok_size = *size;
+
+ cache->kasan_info.free_meta_offset = *size;
+ *size += sizeof(struct kasan_free_meta);
+
+ /* If free meta doesn't fit, don't add it. */
+ if (*size > KMALLOC_MAX_SIZE) {
+ cache->kasan_info.free_meta_offset = KASAN_NO_FREE_META;
+ *size = ok_size;
+ }
+ }
+
+ /* Calculate size with optimal redzone. */
+ optimal_size = cache->object_size + optimal_redzone(cache->object_size);
+ /* Limit it with KMALLOC_MAX_SIZE (relevant for SLAB only). */
+ if (optimal_size > KMALLOC_MAX_SIZE)
+ optimal_size = KMALLOC_MAX_SIZE;
+ /* Use optimal size if the size with added metas is not large enough. */
+ if (*size < optimal_size)
+ *size = optimal_size;
}
-size_t kasan_metadata_size(struct kmem_cache *cache)
+size_t __kasan_metadata_size(struct kmem_cache *cache)
{
+ if (!kasan_stack_collection_enabled())
+ return 0;
return (cache->kasan_info.alloc_meta_offset ?
sizeof(struct kasan_alloc_meta) : 0) +
(cache->kasan_info.free_meta_offset ?
sizeof(struct kasan_free_meta) : 0);
}
-struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,
- const void *object)
+struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
+ const void *object)
{
- return (void *)object + cache->kasan_info.alloc_meta_offset;
+ if (!cache->kasan_info.alloc_meta_offset)
+ return NULL;
+ return kasan_reset_tag(object) + cache->kasan_info.alloc_meta_offset;
}
-struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
- const void *object)
+#ifdef CONFIG_KASAN_GENERIC
+struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
+ const void *object)
{
BUILD_BUG_ON(sizeof(struct kasan_free_meta) > 32);
- return (void *)object + cache->kasan_info.free_meta_offset;
+ if (cache->kasan_info.free_meta_offset == KASAN_NO_FREE_META)
+ return NULL;
+ return kasan_reset_tag(object) + cache->kasan_info.free_meta_offset;
}
+#endif
-void kasan_poison_slab(struct page *page)
+void __kasan_poison_slab(struct page *page)
{
unsigned long i;
KASAN_KMALLOC_REDZONE);
}
-void kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
+void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
{
unpoison_range(object, cache->object_size);
}
-void kasan_poison_object_data(struct kmem_cache *cache, void *object)
+void __kasan_poison_object_data(struct kmem_cache *cache, void *object)
{
- poison_range(object,
- round_up(cache->object_size, KASAN_GRANULE_SIZE),
- KASAN_KMALLOC_REDZONE);
+ poison_range(object, cache->object_size, KASAN_KMALLOC_REDZONE);
}
/*
static u8 assign_tag(struct kmem_cache *cache, const void *object,
bool init, bool keep_tag)
{
+ if (IS_ENABLED(CONFIG_KASAN_GENERIC))
+ return 0xff;
+
/*
* 1. When an object is kmalloc()'ed, two hooks are called:
* kasan_slab_alloc() and kasan_kmalloc(). We assign the
#endif
}
-void * __must_check kasan_init_slab_obj(struct kmem_cache *cache,
+void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,
const void *object)
{
- struct kasan_alloc_meta *alloc_info;
-
- if (!(cache->flags & SLAB_KASAN))
- return (void *)object;
+ struct kasan_alloc_meta *alloc_meta;
- alloc_info = get_alloc_info(cache, object);
- __memset(alloc_info, 0, sizeof(*alloc_info));
+ if (kasan_stack_collection_enabled()) {
+ alloc_meta = kasan_get_alloc_meta(cache, object);
+ if (alloc_meta)
+ __memset(alloc_meta, 0, sizeof(*alloc_meta));
+ }
- if (IS_ENABLED(CONFIG_KASAN_SW_TAGS))
- object = set_tag(object,
- assign_tag(cache, object, true, false));
+ /* Tag is ignored in set_tag() without CONFIG_KASAN_SW/HW_TAGS */
+ object = set_tag(object, assign_tag(cache, object, true, false));
return (void *)object;
}
-static inline bool shadow_invalid(u8 tag, s8 shadow_byte)
-{
- if (IS_ENABLED(CONFIG_KASAN_GENERIC))
- return shadow_byte < 0 ||
- shadow_byte >= KASAN_GRANULE_SIZE;
-
- /* else CONFIG_KASAN_SW_TAGS: */
- if ((u8)shadow_byte == KASAN_TAG_INVALID)
- return true;
- if ((tag != KASAN_TAG_KERNEL) && (tag != (u8)shadow_byte))
- return true;
-
- return false;
-}
-
-static bool __kasan_slab_free(struct kmem_cache *cache, void *object,
+static bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
unsigned long ip, bool quarantine)
{
- s8 shadow_byte;
u8 tag;
void *tagged_object;
- unsigned long rounded_up_size;
tag = get_tag(object);
tagged_object = object;
- object = reset_tag(object);
+ object = kasan_reset_tag(object);
if (unlikely(nearest_obj(cache, virt_to_head_page(object), object) !=
object)) {
if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU))
return false;
- shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object));
- if (shadow_invalid(tag, shadow_byte)) {
+ if (check_invalid_free(tagged_object)) {
kasan_report_invalid_free(tagged_object, ip);
return true;
}
- rounded_up_size = round_up(cache->object_size, KASAN_GRANULE_SIZE);
- poison_range(object, rounded_up_size, KASAN_KMALLOC_FREE);
+ poison_range(object, cache->object_size, KASAN_KMALLOC_FREE);
+
+ if (!kasan_stack_collection_enabled())
+ return false;
- if ((IS_ENABLED(CONFIG_KASAN_GENERIC) && !quarantine) ||
- unlikely(!(cache->flags & SLAB_KASAN)))
+ if ((IS_ENABLED(CONFIG_KASAN_GENERIC) && !quarantine))
return false;
kasan_set_free_info(cache, object, tag);
- quarantine_put(get_free_info(cache, object), cache);
+ return quarantine_put(cache, object);
+}
- return IS_ENABLED(CONFIG_KASAN_GENERIC);
+bool __kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip)
+{
+ return ____kasan_slab_free(cache, object, ip, true);
+}
+
+void __kasan_slab_free_mempool(void *ptr, unsigned long ip)
+{
+ struct page *page;
+
+ page = virt_to_head_page(ptr);
+
+ /*
+ * Even though this function is only called for kmem_cache_alloc and
+ * kmalloc backed mempool allocations, those allocations can still be
+ * !PageSlab() when the size provided to kmalloc is larger than
+ * KMALLOC_MAX_SIZE, and kmalloc falls back onto page_alloc.
+ */
+ if (unlikely(!PageSlab(page))) {
+ if (ptr != page_address(page)) {
+ kasan_report_invalid_free(ptr, ip);
+ return;
+ }
+ poison_range(ptr, page_size(page), KASAN_FREE_PAGE);
+ } else {
+ ____kasan_slab_free(page->slab_cache, ptr, ip, false);
+ }
}
-bool kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip)
+static void set_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
{
- return __kasan_slab_free(cache, object, ip, true);
+ struct kasan_alloc_meta *alloc_meta;
+
+ alloc_meta = kasan_get_alloc_meta(cache, object);
+ if (alloc_meta)
+ kasan_set_track(&alloc_meta->alloc_track, flags);
}
-static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object,
+static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object,
size_t size, gfp_t flags, bool keep_tag)
{
unsigned long redzone_start;
unsigned long redzone_end;
- u8 tag = 0xff;
+ u8 tag;
if (gfpflags_allow_blocking(flags))
quarantine_reduce();
KASAN_GRANULE_SIZE);
redzone_end = round_up((unsigned long)object + cache->object_size,
KASAN_GRANULE_SIZE);
+ tag = assign_tag(cache, object, false, keep_tag);
- if (IS_ENABLED(CONFIG_KASAN_SW_TAGS))
- tag = assign_tag(cache, object, false, keep_tag);
-
- /* Tag is ignored in set_tag without CONFIG_KASAN_SW_TAGS */
+ /* Tag is ignored in set_tag without CONFIG_KASAN_SW/HW_TAGS */
unpoison_range(set_tag(object, tag), size);
poison_range((void *)redzone_start, redzone_end - redzone_start,
KASAN_KMALLOC_REDZONE);
- if (cache->flags & SLAB_KASAN)
- kasan_set_track(&get_alloc_info(cache, object)->alloc_track, flags);
+ if (kasan_stack_collection_enabled())
+ set_alloc_info(cache, (void *)object, flags);
return set_tag(object, tag);
}
-void * __must_check kasan_slab_alloc(struct kmem_cache *cache, void *object,
- gfp_t flags)
+void * __must_check __kasan_slab_alloc(struct kmem_cache *cache,
+ void *object, gfp_t flags)
{
- return __kasan_kmalloc(cache, object, cache->object_size, flags, false);
+ return ____kasan_kmalloc(cache, object, cache->object_size, flags, false);
}
-void * __must_check kasan_kmalloc(struct kmem_cache *cache, const void *object,
- size_t size, gfp_t flags)
+void * __must_check __kasan_kmalloc(struct kmem_cache *cache, const void *object,
+ size_t size, gfp_t flags)
{
- return __kasan_kmalloc(cache, object, size, flags, true);
+ return ____kasan_kmalloc(cache, object, size, flags, true);
}
-EXPORT_SYMBOL(kasan_kmalloc);
+EXPORT_SYMBOL(__kasan_kmalloc);
-void * __must_check kasan_kmalloc_large(const void *ptr, size_t size,
+void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
gfp_t flags)
{
struct page *page;
return (void *)ptr;
}
-void * __must_check kasan_krealloc(const void *object, size_t size, gfp_t flags)
+void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flags)
{
struct page *page;
page = virt_to_head_page(object);
if (unlikely(!PageSlab(page)))
- return kasan_kmalloc_large(object, size, flags);
+ return __kasan_kmalloc_large(object, size, flags);
else
- return __kasan_kmalloc(page->slab_cache, object, size,
+ return ____kasan_kmalloc(page->slab_cache, object, size,
flags, true);
}
-void kasan_poison_kfree(void *ptr, unsigned long ip)
-{
- struct page *page;
-
- page = virt_to_head_page(ptr);
-
- if (unlikely(!PageSlab(page))) {
- if (ptr != page_address(page)) {
- kasan_report_invalid_free(ptr, ip);
- return;
- }
- poison_range(ptr, page_size(page), KASAN_FREE_PAGE);
- } else {
- __kasan_slab_free(page->slab_cache, ptr, ip, false);
- }
-}
-
-void kasan_kfree_large(void *ptr, unsigned long ip)
+void __kasan_kfree_large(void *ptr, unsigned long ip)
{
if (ptr != page_address(virt_to_head_page(ptr)))
kasan_report_invalid_free(ptr, ip);
- /* The object will be poisoned by page_alloc. */
+ /* The object will be poisoned by kasan_free_pages(). */
}
projects / linux-2.6-microblaze.git / blobdiff