2 #include <linux/mm_types.h>
4 #include <linux/slab.h>
6 #include <linux/kmemcheck.h>
8 void kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node)
17 * With kmemcheck enabled, we need to allocate a memory area for the
18 * shadow bits as well.
20 shadow = alloc_pages_node(node, flags | __GFP_NOTRACK, order);
22 if (printk_ratelimit())
23 printk(KERN_ERR "kmemcheck: failed to allocate "
28 for(i = 0; i < pages; ++i)
29 page[i].shadow = page_address(&shadow[i]);
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.
36 kmemcheck_hide_pages(page, pages);
39 void kmemcheck_free_shadow(struct page *page, int order)
45 if (!kmemcheck_page_is_tracked(page))
50 kmemcheck_show_pages(page, pages);
52 shadow = virt_to_page(page[0].shadow);
54 for(i = 0; i < pages; ++i)
55 page[i].shadow = NULL;
57 __free_pages(shadow, order);
60 void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
63 if (unlikely(!object)) /* Skip object if allocation failed */
67 * Has already been memset(), which initializes the shadow for us
70 if (gfpflags & __GFP_ZERO)
73 /* No need to initialize the shadow of a non-tracked slab. */
74 if (s->flags & SLAB_NOTRACK)
77 if (!kmemcheck_enabled || gfpflags & __GFP_NOTRACK) {
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.
86 kmemcheck_mark_initialized(object, size);
87 } else if (!s->ctor) {
89 * New objects should be marked uninitialized before
90 * they're returned to the called.
92 kmemcheck_mark_uninitialized(object, size);
96 void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size)
98 /* TODO: RCU freeing is unsupported for now; hide false positives. */
99 if (!s->ctor && !(s->flags & SLAB_DESTROY_BY_RCU))
100 kmemcheck_mark_freed(object, size);
103 void kmemcheck_pagealloc_alloc(struct page *page, unsigned int order,
108 if (gfpflags & (__GFP_HIGHMEM | __GFP_NOTRACK))
114 * NOTE: We choose to track GFP_ZERO pages too; in fact, they
115 * can become uninitialized by copying uninitialized memory
119 /* XXX: Can use zone->node for node? */
120 kmemcheck_alloc_shadow(page, order, gfpflags, -1);
122 if (gfpflags & __GFP_ZERO)
123 kmemcheck_mark_initialized_pages(page, pages);
125 kmemcheck_mark_uninitialized_pages(page, pages);