[PATCH v13 02/25] kasan, slub: handle pointer tags in early_kmem_cache_node_alloc

From: Andrey Konovalov
Date: Thu Dec 06 2018 - 07:27:37 EST


The previous patch updated KASAN hooks signatures and their usage in SLAB
and SLUB code, except for the early_kmem_cache_node_alloc function. This
patch handles that function separately, as it requires to reorder some of
the initialization code to correctly propagate a tagged pointer in case a
tag is assigned by kasan_kmalloc.

Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
---
mm/slub.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index fdd4a86aa882..8561a32910dd 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3364,16 +3364,16 @@ static void early_kmem_cache_node_alloc(int node)

n = page->freelist;
BUG_ON(!n);
- page->freelist = get_freepointer(kmem_cache_node, n);
- page->inuse = 1;
- page->frozen = 0;
- kmem_cache_node->node[node] = n;
#ifdef CONFIG_SLUB_DEBUG
init_object(kmem_cache_node, n, SLUB_RED_ACTIVE);
init_tracking(kmem_cache_node, n);
#endif
- kasan_kmalloc(kmem_cache_node, n, sizeof(struct kmem_cache_node),
+ n = kasan_kmalloc(kmem_cache_node, n, sizeof(struct kmem_cache_node),
GFP_KERNEL);
+ page->freelist = get_freepointer(kmem_cache_node, n);
+ page->inuse = 1;
+ page->frozen = 0;
+ kmem_cache_node->node[node] = n;
init_kmem_cache_node(n);
inc_slabs_node(kmem_cache_node, node, page->objects);

--
2.20.0.rc1.387.gf8505762e3-goog