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>

1 files changed, 18 insertions, 5 deletions

diff --git a/mm/slub.c b/mm/slub.c
index 1cebaa747ad3..898fb5047dcc 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1066,6 +1066,8 @@ static inline struct page *alloc_slab_page(gfp_t flags, int node,
 {
         int order = oo_order(oo);
 
+        flags |= __GFP_NOTRACK;
+
         if (node == -1)
                 return alloc_pages(flags, order);
         else
@@ -1097,7 +1099,18 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
         if (kmemcheck_enabled
                 && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS)))
         {
-                kmemcheck_alloc_shadow(s, flags, node, page, compound_order(page));
+                int pages = 1 << oo_order(oo);
+
+                kmemcheck_alloc_shadow(page, oo_order(oo), flags, node);
+
+                /*
+                 * 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);
         }
 
         page->objects = oo_objects(oo);
@@ -1173,8 +1186,7 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
                 __ClearPageSlubDebug(page);
         }
 
-        if (kmemcheck_page_is_tracked(page))
-                kmemcheck_free_shadow(s, page, compound_order(page));
+        kmemcheck_free_shadow(page, compound_order(page));
 
         mod_zone_page_state(page_zone(page),
                 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
@@ -2734,9 +2746,10 @@ EXPORT_SYMBOL(__kmalloc);
 
 static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
 {
-        struct page *page = alloc_pages_node(node, flags | __GFP_COMP,
-                                                get_order(size));
+        struct page *page;
 
+        flags |= __GFP_COMP | __GFP_NOTRACK;
+        page = alloc_pages_node(node, flags, get_order(size));
         if (page)
                 return page_address(page);
         else