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