From 47b5c2a0f021e90a79845d1a1353780e5edd0bce Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Tue, 2 Aug 2016 14:02:49 -0700 Subject: [PATCH] mm/kasan: get rid of ->alloc_size in struct kasan_alloc_meta Size of slab object already stored in cache->object_size. Note, that kmalloc() internally rounds up size of allocation, so object_size may be not equal to alloc_size, but, usually we don't need to know the exact size of allocated object. In case if we need that information, we still can figure it out from the report. The dump of shadow memory allows to identify the end of allocated memory, and thereby the exact allocation size. Link: http://lkml.kernel.org/r/1470062715-14077-4-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin Cc: Alexander Potapenko Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/kasan/kasan.c | 1 - mm/kasan/kasan.h | 3 +-- mm/kasan/report.c | 8 +++----- 3 files changed, 4 insertions(+), 8 deletions(-) diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index c99ef40..388e812 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -584,7 +584,6 @@ void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size, get_alloc_info(cache, object); alloc_info->state = KASAN_STATE_ALLOC; - alloc_info->alloc_size = size; set_track(&alloc_info->track, flags); } } diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 31972cd..aa17546 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -75,8 +75,7 @@ struct kasan_track { struct kasan_alloc_meta { struct kasan_track track; - u32 state : 2; /* enum kasan_state */ - u32 alloc_size : 30; + u32 state; }; struct qlist_node { diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 861b977..d67a7e0 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -136,7 +136,9 @@ static void kasan_object_err(struct kmem_cache *cache, struct page *page, struct kasan_free_meta *free_info; dump_stack(); - pr_err("Object at %p, in cache %s\n", object, cache->name); + pr_err("Object at %p, in cache %s size: %d\n", object, cache->name, + cache->object_size); + if (!(cache->flags & SLAB_KASAN)) return; switch (alloc_info->state) { @@ -144,15 +146,11 @@ static void kasan_object_err(struct kmem_cache *cache, struct page *page, pr_err("Object not allocated yet\n"); break; case KASAN_STATE_ALLOC: - pr_err("Object allocated with size %u bytes.\n", - alloc_info->alloc_size); pr_err("Allocation:\n"); print_track(&alloc_info->track); break; case KASAN_STATE_FREE: case KASAN_STATE_QUARANTINE: - pr_err("Object freed, allocated with size %u bytes\n", - alloc_info->alloc_size); free_info = get_free_info(cache, object); pr_err("Allocation:\n"); print_track(&alloc_info->track); -- 2.7.4