summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorSuren Baghdasaryan <surenb@google.com>2022-07-31 11:19:31 -0700
committerSuren Baghdasaryan <surenb@google.com>2024-03-05 15:58:58 +0000
commit9451386d2cb8832d42a07099e2874606517fde1b (patch)
tree81fa19a8219f569b79707d79be18298d3d93a1b0
parent4e8da0047c46d35a5dee3d9083f3dea1d622d04f (diff)
mm: introduce __GFP_NO_OBJ_EXT flag to selectively prevent slabobj_ext creation
Introduce __GFP_NO_OBJ_EXT flag in order to prevent recursive allocations when allocating slabobj_ext on a slab. Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
-rw-r--r--include/linux/gfp_types.h11
-rw-r--r--mm/slub.c2
2 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h
index 868c8fb1bbc1..e36e168d8cfd 100644
--- a/include/linux/gfp_types.h
+++ b/include/linux/gfp_types.h
@@ -53,6 +53,9 @@ enum {
#ifdef CONFIG_LOCKDEP
___GFP_NOLOCKDEP_BIT,
#endif
+#ifdef CONFIG_SLAB_OBJ_EXT
+ ___GFP_NO_OBJ_EXT_BIT,
+#endif
___GFP_LAST_BIT
};
@@ -93,6 +96,11 @@ enum {
#else
#define ___GFP_NOLOCKDEP 0
#endif
+#ifdef CONFIG_SLAB_OBJ_EXT
+#define ___GFP_NO_OBJ_EXT BIT(___GFP_NO_OBJ_EXT_BIT)
+#else
+#define ___GFP_NO_OBJ_EXT 0
+#endif
/*
* Physical address zone modifiers (see linux/mmzone.h - low four bits)
@@ -133,12 +141,15 @@ enum {
* node with no fallbacks or placement policy enforcements.
*
* %__GFP_ACCOUNT causes the allocation to be accounted to kmemcg.
+ *
+ * %__GFP_NO_OBJ_EXT causes slab allocation to have no object extension.
*/
#define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE)
#define __GFP_WRITE ((__force gfp_t)___GFP_WRITE)
#define __GFP_HARDWALL ((__force gfp_t)___GFP_HARDWALL)
#define __GFP_THISNODE ((__force gfp_t)___GFP_THISNODE)
#define __GFP_ACCOUNT ((__force gfp_t)___GFP_ACCOUNT)
+#define __GFP_NO_OBJ_EXT ((__force gfp_t)___GFP_NO_OBJ_EXT)
/**
* DOC: Watermark modifiers
diff --git a/mm/slub.c b/mm/slub.c
index 6ab9f8f38ac5..2ba5d7b2711d 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1899,6 +1899,8 @@ static int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
void *vec;
gfp &= ~OBJCGS_CLEAR_MASK;
+ /* Prevent recursive extension vector allocation */
+ gfp |= __GFP_NO_OBJ_EXT;
vec = kcalloc_node(objects, sizeof(struct slabobj_ext), gfp,
slab_nid(slab));
if (!vec)