kmemcheck: add hooks for the page allocator
This adds support for tracking the initializedness of memory that
was allocated with the page allocator. Highmem requests are not
tracked.
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
[build fix for !CONFIG_KMEMCHECK]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
diff --git a/mm/kmemcheck.c b/mm/kmemcheck.c
index eaa41b8..fd814fd 100644
--- a/mm/kmemcheck.c
+++ b/mm/kmemcheck.c
@@ -1,10 +1,10 @@
+#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 kmem_cache *s, gfp_t flags, int node,
- struct page *page, int order)
+void kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node)
{
struct page *shadow;
int pages;
@@ -16,7 +16,7 @@
* With kmemcheck enabled, we need to allocate a memory area for the
* shadow bits as well.
*/
- shadow = alloc_pages_node(node, flags, order);
+ shadow = alloc_pages_node(node, flags | __GFP_NOTRACK, order);
if (!shadow) {
if (printk_ratelimit())
printk(KERN_ERR "kmemcheck: failed to allocate "
@@ -33,23 +33,17 @@
* the memory accesses.
*/
kmemcheck_hide_pages(page, pages);
-
- /*
- * Objects from caches that have a constructor don't get
- * cleared when they're allocated, so we need to do it here.
- */
- if (s->ctor)
- kmemcheck_mark_uninitialized_pages(page, pages);
- else
- kmemcheck_mark_unallocated_pages(page, pages);
}
-void kmemcheck_free_shadow(struct kmem_cache *s, struct page *page, int order)
+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);
@@ -101,3 +95,28 @@
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);
+}