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ecf3b270 SL |
1 | From a8146d43007331bebbe675fd3acbcd6a46342a37 Mon Sep 17 00:00:00 2001 |
2 | From: Andrey Konovalov <andreyknvl@google.com> | |
3 | Date: Wed, 20 Feb 2019 22:19:23 -0800 | |
4 | Subject: kasan, slub: move kasan_poison_slab hook before page_address | |
5 | ||
6 | [ Upstream commit a71012242837fe5e67d8c999cfc357174ed5dba0 ] | |
7 | ||
8 | With tag based KASAN page_address() looks at the page flags to see whether | |
9 | the resulting pointer needs to have a tag set. Since we don't want to set | |
10 | a tag when page_address() is called on SLAB pages, we call | |
11 | page_kasan_tag_reset() in kasan_poison_slab(). However in allocate_slab() | |
12 | page_address() is called before kasan_poison_slab(). Fix it by changing | |
13 | the order. | |
14 | ||
15 | [andreyknvl@google.com: fix compilation error when CONFIG_SLUB_DEBUG=n] | |
16 | Link: http://lkml.kernel.org/r/ac27cc0bbaeb414ed77bcd6671a877cf3546d56e.1550066133.git.andreyknvl@google.com | |
17 | Link: http://lkml.kernel.org/r/cd895d627465a3f1c712647072d17f10883be2a1.1549921721.git.andreyknvl@google.com | |
18 | Signed-off-by: Andrey Konovalov <andreyknvl@google.com> | |
19 | Cc: Alexander Potapenko <glider@google.com> | |
20 | Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> | |
21 | Cc: Catalin Marinas <catalin.marinas@arm.com> | |
22 | Cc: Christoph Lameter <cl@linux.com> | |
23 | Cc: David Rientjes <rientjes@google.com> | |
24 | Cc: Dmitry Vyukov <dvyukov@google.com> | |
25 | Cc: Evgeniy Stepanov <eugenis@google.com> | |
26 | Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> | |
27 | Cc: Kostya Serebryany <kcc@google.com> | |
28 | Cc: Pekka Enberg <penberg@kernel.org> | |
29 | Cc: Qian Cai <cai@lca.pw> | |
30 | Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> | |
31 | Signed-off-by: Andrew Morton <akpm@linux-foundation.org> | |
32 | Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> | |
33 | Signed-off-by: Sasha Levin <sashal@kernel.org> | |
34 | --- | |
35 | mm/slub.c | 19 +++++++++++++++---- | |
36 | 1 file changed, 15 insertions(+), 4 deletions(-) | |
37 | ||
38 | diff --git a/mm/slub.c b/mm/slub.c | |
39 | index 220d42e592ef..f14ef59c9e57 100644 | |
40 | --- a/mm/slub.c | |
41 | +++ b/mm/slub.c | |
42 | @@ -1087,6 +1087,16 @@ static void setup_object_debug(struct kmem_cache *s, struct page *page, | |
43 | init_tracking(s, object); | |
44 | } | |
45 | ||
46 | +static void setup_page_debug(struct kmem_cache *s, void *addr, int order) | |
47 | +{ | |
48 | + if (!(s->flags & SLAB_POISON)) | |
49 | + return; | |
50 | + | |
51 | + metadata_access_enable(); | |
52 | + memset(addr, POISON_INUSE, PAGE_SIZE << order); | |
53 | + metadata_access_disable(); | |
54 | +} | |
55 | + | |
56 | static inline int alloc_consistency_checks(struct kmem_cache *s, | |
57 | struct page *page, | |
58 | void *object, unsigned long addr) | |
59 | @@ -1304,6 +1314,8 @@ unsigned long kmem_cache_flags(unsigned long object_size, | |
60 | #else /* !CONFIG_SLUB_DEBUG */ | |
61 | static inline void setup_object_debug(struct kmem_cache *s, | |
62 | struct page *page, void *object) {} | |
63 | +static inline void setup_page_debug(struct kmem_cache *s, | |
64 | + void *addr, int order) {} | |
65 | ||
66 | static inline int alloc_debug_processing(struct kmem_cache *s, | |
67 | struct page *page, void *object, unsigned long addr) { return 0; } | |
68 | @@ -1599,12 +1611,11 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) | |
69 | if (page_is_pfmemalloc(page)) | |
70 | SetPageSlabPfmemalloc(page); | |
71 | ||
72 | - start = page_address(page); | |
73 | + kasan_poison_slab(page); | |
74 | ||
75 | - if (unlikely(s->flags & SLAB_POISON)) | |
76 | - memset(start, POISON_INUSE, PAGE_SIZE << order); | |
77 | + start = page_address(page); | |
78 | ||
79 | - kasan_poison_slab(page); | |
80 | + setup_page_debug(s, start, order); | |
81 | ||
82 | shuffle = shuffle_freelist(s, page); | |
83 | ||
84 | -- | |
85 | 2.19.1 | |
86 |