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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
b1eeab67 | 2 | #include <linux/gfp.h> |
2dff4405 VN |
3 | #include <linux/mm_types.h> |
4 | #include <linux/mm.h> | |
5 | #include <linux/slab.h> | |
07f361b2 | 6 | #include "slab.h" |
2dff4405 VN |
7 | #include <linux/kmemcheck.h> |
8 | ||
b1eeab67 | 9 | void kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node) |
2dff4405 VN |
10 | { |
11 | struct page *shadow; | |
12 | int pages; | |
13 | int i; | |
14 | ||
15 | pages = 1 << order; | |
16 | ||
17 | /* | |
18 | * With kmemcheck enabled, we need to allocate a memory area for the | |
19 | * shadow bits as well. | |
20 | */ | |
b1eeab67 | 21 | shadow = alloc_pages_node(node, flags | __GFP_NOTRACK, order); |
2dff4405 VN |
22 | if (!shadow) { |
23 | if (printk_ratelimit()) | |
1170532b | 24 | pr_err("kmemcheck: failed to allocate shadow bitmap\n"); |
2dff4405 VN |
25 | return; |
26 | } | |
27 | ||
28 | for(i = 0; i < pages; ++i) | |
29 | page[i].shadow = page_address(&shadow[i]); | |
30 | ||
31 | /* | |
32 | * Mark it as non-present for the MMU so that our accesses to | |
33 | * this memory will trigger a page fault and let us analyze | |
34 | * the memory accesses. | |
35 | */ | |
36 | kmemcheck_hide_pages(page, pages); | |
2dff4405 VN |
37 | } |
38 | ||
b1eeab67 | 39 | void kmemcheck_free_shadow(struct page *page, int order) |
2dff4405 VN |
40 | { |
41 | struct page *shadow; | |
42 | int pages; | |
43 | int i; | |
44 | ||
b1eeab67 VN |
45 | if (!kmemcheck_page_is_tracked(page)) |
46 | return; | |
47 | ||
2dff4405 VN |
48 | pages = 1 << order; |
49 | ||
50 | kmemcheck_show_pages(page, pages); | |
51 | ||
52 | shadow = virt_to_page(page[0].shadow); | |
53 | ||
54 | for(i = 0; i < pages; ++i) | |
55 | page[i].shadow = NULL; | |
56 | ||
57 | __free_pages(shadow, order); | |
58 | } | |
59 | ||
60 | void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object, | |
61 | size_t size) | |
62 | { | |
0142eae3 JDB |
63 | if (unlikely(!object)) /* Skip object if allocation failed */ |
64 | return; | |
65 | ||
2dff4405 VN |
66 | /* |
67 | * Has already been memset(), which initializes the shadow for us | |
68 | * as well. | |
69 | */ | |
70 | if (gfpflags & __GFP_ZERO) | |
71 | return; | |
72 | ||
73 | /* No need to initialize the shadow of a non-tracked slab. */ | |
74 | if (s->flags & SLAB_NOTRACK) | |
75 | return; | |
76 | ||
77 | if (!kmemcheck_enabled || gfpflags & __GFP_NOTRACK) { | |
78 | /* | |
79 | * Allow notracked objects to be allocated from | |
80 | * tracked caches. Note however that these objects | |
81 | * will still get page faults on access, they just | |
82 | * won't ever be flagged as uninitialized. If page | |
83 | * faults are not acceptable, the slab cache itself | |
84 | * should be marked NOTRACK. | |
85 | */ | |
86 | kmemcheck_mark_initialized(object, size); | |
87 | } else if (!s->ctor) { | |
88 | /* | |
89 | * New objects should be marked uninitialized before | |
90 | * they're returned to the called. | |
91 | */ | |
92 | kmemcheck_mark_uninitialized(object, size); | |
93 | } | |
94 | } | |
95 | ||
96 | void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size) | |
97 | { | |
98 | /* TODO: RCU freeing is unsupported for now; hide false positives. */ | |
5f0d5a3a | 99 | if (!s->ctor && !(s->flags & SLAB_TYPESAFE_BY_RCU)) |
2dff4405 VN |
100 | kmemcheck_mark_freed(object, size); |
101 | } | |
b1eeab67 VN |
102 | |
103 | void kmemcheck_pagealloc_alloc(struct page *page, unsigned int order, | |
104 | gfp_t gfpflags) | |
105 | { | |
106 | int pages; | |
107 | ||
108 | if (gfpflags & (__GFP_HIGHMEM | __GFP_NOTRACK)) | |
109 | return; | |
110 | ||
111 | pages = 1 << order; | |
112 | ||
113 | /* | |
114 | * NOTE: We choose to track GFP_ZERO pages too; in fact, they | |
115 | * can become uninitialized by copying uninitialized memory | |
116 | * into them. | |
117 | */ | |
118 | ||
119 | /* XXX: Can use zone->node for node? */ | |
120 | kmemcheck_alloc_shadow(page, order, gfpflags, -1); | |
121 | ||
122 | if (gfpflags & __GFP_ZERO) | |
123 | kmemcheck_mark_initialized_pages(page, pages); | |
124 | else | |
125 | kmemcheck_mark_uninitialized_pages(page, pages); | |
126 | } |