Commit | Line | Data |
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b1eeab67 | 1 | #include <linux/gfp.h> |
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2 | #include <linux/mm_types.h> |
3 | #include <linux/mm.h> | |
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4 | #include <linux/kmemcheck.h> |
5 | ||
b1eeab67 | 6 | void kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node) |
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7 | { |
8 | struct page *shadow; | |
9 | int pages; | |
10 | int i; | |
11 | ||
12 | pages = 1 << order; | |
13 | ||
14 | /* | |
15 | * With kmemcheck enabled, we need to allocate a memory area for the | |
16 | * shadow bits as well. | |
17 | */ | |
b1eeab67 | 18 | shadow = alloc_pages_node(node, flags | __GFP_NOTRACK, order); |
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19 | if (!shadow) { |
20 | if (printk_ratelimit()) | |
21 | printk(KERN_ERR "kmemcheck: failed to allocate " | |
22 | "shadow bitmap\n"); | |
23 | return; | |
24 | } | |
25 | ||
26 | for(i = 0; i < pages; ++i) | |
27 | page[i].shadow = page_address(&shadow[i]); | |
28 | ||
29 | /* | |
30 | * Mark it as non-present for the MMU so that our accesses to | |
31 | * this memory will trigger a page fault and let us analyze | |
32 | * the memory accesses. | |
33 | */ | |
34 | kmemcheck_hide_pages(page, pages); | |
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35 | } |
36 | ||
b1eeab67 | 37 | void kmemcheck_free_shadow(struct page *page, int order) |
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38 | { |
39 | struct page *shadow; | |
40 | int pages; | |
41 | int i; | |
42 | ||
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43 | if (!kmemcheck_page_is_tracked(page)) |
44 | return; | |
45 | ||
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46 | pages = 1 << order; |
47 | ||
48 | kmemcheck_show_pages(page, pages); | |
49 | ||
50 | shadow = virt_to_page(page[0].shadow); | |
51 | ||
52 | for(i = 0; i < pages; ++i) | |
53 | page[i].shadow = NULL; | |
54 | ||
55 | __free_pages(shadow, order); | |
56 | } | |
57 | ||
58 | void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object, | |
59 | size_t size) | |
60 | { | |
61 | /* | |
62 | * Has already been memset(), which initializes the shadow for us | |
63 | * as well. | |
64 | */ | |
65 | if (gfpflags & __GFP_ZERO) | |
66 | return; | |
67 | ||
68 | /* No need to initialize the shadow of a non-tracked slab. */ | |
69 | if (s->flags & SLAB_NOTRACK) | |
70 | return; | |
71 | ||
72 | if (!kmemcheck_enabled || gfpflags & __GFP_NOTRACK) { | |
73 | /* | |
74 | * Allow notracked objects to be allocated from | |
75 | * tracked caches. Note however that these objects | |
76 | * will still get page faults on access, they just | |
77 | * won't ever be flagged as uninitialized. If page | |
78 | * faults are not acceptable, the slab cache itself | |
79 | * should be marked NOTRACK. | |
80 | */ | |
81 | kmemcheck_mark_initialized(object, size); | |
82 | } else if (!s->ctor) { | |
83 | /* | |
84 | * New objects should be marked uninitialized before | |
85 | * they're returned to the called. | |
86 | */ | |
87 | kmemcheck_mark_uninitialized(object, size); | |
88 | } | |
89 | } | |
90 | ||
91 | void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size) | |
92 | { | |
93 | /* TODO: RCU freeing is unsupported for now; hide false positives. */ | |
94 | if (!s->ctor && !(s->flags & SLAB_DESTROY_BY_RCU)) | |
95 | kmemcheck_mark_freed(object, size); | |
96 | } | |
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97 | |
98 | void kmemcheck_pagealloc_alloc(struct page *page, unsigned int order, | |
99 | gfp_t gfpflags) | |
100 | { | |
101 | int pages; | |
102 | ||
103 | if (gfpflags & (__GFP_HIGHMEM | __GFP_NOTRACK)) | |
104 | return; | |
105 | ||
106 | pages = 1 << order; | |
107 | ||
108 | /* | |
109 | * NOTE: We choose to track GFP_ZERO pages too; in fact, they | |
110 | * can become uninitialized by copying uninitialized memory | |
111 | * into them. | |
112 | */ | |
113 | ||
114 | /* XXX: Can use zone->node for node? */ | |
115 | kmemcheck_alloc_shadow(page, order, gfpflags, -1); | |
116 | ||
117 | if (gfpflags & __GFP_ZERO) | |
118 | kmemcheck_mark_initialized_pages(page, pages); | |
119 | else | |
120 | kmemcheck_mark_uninitialized_pages(page, pages); | |
121 | } |