From e4b7818b9aa8fa8dfd5fc7bb98f0d4c16b50fd8b Mon Sep 17 00:00:00 2001 From: Walter Wu Date: Thu, 6 Aug 2020 23:24:39 -0700 Subject: kasan: record and print the free track Move free track from kasan_alloc_meta to kasan_free_meta in order to make struct kasan_alloc_meta and kasan_free_meta size are both 16 bytes. It is a good size because it is the minimal redzone size and a good number of alignment. For free track, we make some modifications as shown below: 1) Remove the free_track from struct kasan_alloc_meta. 2) Add the free_track into struct kasan_free_meta. 3) Add a macro KASAN_KMALLOC_FREETRACK in order to check whether it can print free stack in KASAN report. [1]https://bugzilla.kernel.org/show_bug.cgi?id=198437 [walter-zh.wu@mediatek.com: build fix] Link: http://lkml.kernel.org/r/20200710162440.23887-1-walter-zh.wu@mediatek.com Suggested-by: Dmitry Vyukov Co-developed-by: Dmitry Vyukov Signed-off-by: Walter Wu Signed-off-by: Andrew Morton Tested-by: Dmitry Vyukov Reviewed-by: Dmitry Vyukov Reviewed-by: Andrey Konovalov Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Joel Fernandes Cc: Jonathan Corbet Cc: Josh Triplett Cc: Lai Jiangshan Cc: Mathieu Desnoyers Cc: Matthias Brugger Cc: "Paul E . McKenney" Link: http://lkml.kernel.org/r/20200601051022.1230-1-walter-zh.wu@mediatek.com Signed-off-by: Linus Torvalds --- mm/kasan/kasan.h | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'mm/kasan/kasan.h') diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index f89a195e336a..ac499456740f 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -17,15 +17,17 @@ #define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocations */ #define KASAN_KMALLOC_REDZONE 0xFC /* redzone inside slub object */ #define KASAN_KMALLOC_FREE 0xFB /* object was freed (kmem_cache_free/kfree) */ +#define KASAN_KMALLOC_FREETRACK 0xFA /* object was freed and has free track set */ #else #define KASAN_FREE_PAGE KASAN_TAG_INVALID #define KASAN_PAGE_REDZONE KASAN_TAG_INVALID #define KASAN_KMALLOC_REDZONE KASAN_TAG_INVALID #define KASAN_KMALLOC_FREE KASAN_TAG_INVALID +#define KASAN_KMALLOC_FREETRACK KASAN_TAG_INVALID #endif -#define KASAN_GLOBAL_REDZONE 0xFA /* redzone for global variable */ -#define KASAN_VMALLOC_INVALID 0xF9 /* unallocated space in vmapped page */ +#define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */ +#define KASAN_VMALLOC_INVALID 0xF8 /* unallocated space in vmapped page */ /* * Stack redzone shadow values @@ -110,8 +112,9 @@ struct kasan_alloc_meta { * The free stack is stored into struct kasan_free_meta. */ depot_stack_handle_t aux_stack[2]; -#endif +#else struct kasan_track free_track[KASAN_NR_FREE_STACKS]; +#endif #ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY u8 free_pointer_tag[KASAN_NR_FREE_STACKS]; u8 free_track_idx; @@ -126,6 +129,9 @@ struct kasan_free_meta { * Otherwise it might be used for the allocator freelist. */ struct qlist_node quarantine_link; +#ifdef CONFIG_KASAN_GENERIC + struct kasan_track free_track; +#endif }; struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache, @@ -167,6 +173,10 @@ void kasan_report_invalid_free(void *object, unsigned long ip); struct page *kasan_addr_to_page(const void *addr); depot_stack_handle_t kasan_save_stack(gfp_t flags); +void kasan_set_track(struct kasan_track *track, gfp_t flags); +void kasan_set_free_info(struct kmem_cache *cache, void *object, u8 tag); +struct kasan_track *kasan_get_free_track(struct kmem_cache *cache, + void *object, u8 tag); #if defined(CONFIG_KASAN_GENERIC) && \ (defined(CONFIG_SLAB) || defined(CONFIG_SLUB)) -- cgit v1.2.3