125 lines
2.9 KiB
C
125 lines
2.9 KiB
C
#include <linux/gfp.h>
|
|
#include <linux/mm_types.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/slab.h>
|
|
#include "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())
|
|
pr_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)
|
|
{
|
|
if (unlikely(!object)) /* Skip object if allocation failed */
|
|
return;
|
|
|
|
/*
|
|
* 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);
|
|
}
|