2 #include <linux/mm_types.h>
4 #include <linux/kmemcheck.h>
6 void kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node)
15 * With kmemcheck enabled, we need to allocate a memory area for the
16 * shadow bits as well.
18 shadow = alloc_pages_node(node, flags | __GFP_NOTRACK, order);
20 if (printk_ratelimit())
21 printk(KERN_ERR "kmemcheck: failed to allocate "
26 for(i = 0; i < pages; ++i)
27 page[i].shadow = page_address(&shadow[i]);
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.
34 kmemcheck_hide_pages(page, pages);
37 void kmemcheck_free_shadow(struct page *page, int order)
43 if (!kmemcheck_page_is_tracked(page))
48 kmemcheck_show_pages(page, pages);
50 shadow = virt_to_page(page[0].shadow);
52 for(i = 0; i < pages; ++i)
53 page[i].shadow = NULL;
55 __free_pages(shadow, order);
58 void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
62 * Has already been memset(), which initializes the shadow for us
65 if (gfpflags & __GFP_ZERO)
68 /* No need to initialize the shadow of a non-tracked slab. */
69 if (s->flags & SLAB_NOTRACK)
72 if (!kmemcheck_enabled || gfpflags & __GFP_NOTRACK) {
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.
81 kmemcheck_mark_initialized(object, size);
82 } else if (!s->ctor) {
84 * New objects should be marked uninitialized before
85 * they're returned to the called.
87 kmemcheck_mark_uninitialized(object, size);
91 void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size)
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);
98 void kmemcheck_pagealloc_alloc(struct page *page, unsigned int order,
103 if (gfpflags & (__GFP_HIGHMEM | __GFP_NOTRACK))
109 * NOTE: We choose to track GFP_ZERO pages too; in fact, they
110 * can become uninitialized by copying uninitialized memory
114 /* XXX: Can use zone->node for node? */
115 kmemcheck_alloc_shadow(page, order, gfpflags, -1);
117 if (gfpflags & __GFP_ZERO)
118 kmemcheck_mark_initialized_pages(page, pages);
120 kmemcheck_mark_uninitialized_pages(page, pages);