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
);