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/common.c | 22 ++-------------------- 1 file changed, 2 insertions(+), 20 deletions(-) (limited to 'mm/kasan/common.c') diff --git a/mm/kasan/common.c b/mm/kasan/common.c index ad24666f50e4..f18067736f7c 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -50,7 +50,7 @@ depot_stack_handle_t kasan_save_stack(gfp_t flags) return stack_depot_save(entries, nr_entries, flags); } -static inline void set_track(struct kasan_track *track, gfp_t flags) +void kasan_set_track(struct kasan_track *track, gfp_t flags) { track->pid = current->pid; track->stack = kasan_save_stack(flags); @@ -298,24 +298,6 @@ struct kasan_free_meta *get_free_info(struct kmem_cache *cache, return (void *)object + cache->kasan_info.free_meta_offset; } - -static void kasan_set_free_info(struct kmem_cache *cache, - void *object, u8 tag) -{ - struct kasan_alloc_meta *alloc_meta; - u8 idx = 0; - - alloc_meta = get_alloc_info(cache, object); - -#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY - idx = alloc_meta->free_track_idx; - alloc_meta->free_pointer_tag[idx] = tag; - alloc_meta->free_track_idx = (idx + 1) % KASAN_NR_FREE_STACKS; -#endif - - set_track(&alloc_meta->free_track[idx], GFP_NOWAIT); -} - void kasan_poison_slab(struct page *page) { unsigned long i; @@ -491,7 +473,7 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, KASAN_KMALLOC_REDZONE); if (cache->flags & SLAB_KASAN) - set_track(&get_alloc_info(cache, object)->alloc_track, flags); + kasan_set_track(&get_alloc_info(cache, object)->alloc_track, flags); return set_tag(object, tag); } -- cgit v1.2.3