From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Evict stack traces from the stack depot for the tag-based KASAN modes once they are evicted from the stack ring. Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> --- mm/kasan/tags.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c index 7dcfe341d48e..fa6b0f77a7dd 100644 --- a/mm/kasan/tags.c +++ b/mm/kasan/tags.c @@ -96,7 +96,7 @@ static void save_stack_info(struct kmem_cache *cache, void *object, gfp_t gfp_flags, bool is_free) { unsigned long flags; - depot_stack_handle_t stack; + depot_stack_handle_t stack, old_stack; u64 pos; struct kasan_stack_ring_entry *entry; void *old_ptr; @@ -120,6 +120,8 @@ static void save_stack_info(struct kmem_cache *cache, void *object, if (!try_cmpxchg(&entry->ptr, &old_ptr, STACK_RING_BUSY_PTR)) goto next; /* Busy slot. */ + old_stack = READ_ONCE(entry->stack); + WRITE_ONCE(entry->size, cache->object_size); WRITE_ONCE(entry->pid, current->pid); WRITE_ONCE(entry->stack, stack); @@ -131,6 +133,9 @@ static void save_stack_info(struct kmem_cache *cache, void *object, smp_store_release(&entry->ptr, (s64)object); read_unlock_irqrestore(&stack_ring.lock, flags); + + if (old_stack) + stack_depot_evict(old_stack); } void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags) -- 2.25.1