4 files changed, 32 insertions, 25 deletions

diff --git a/mm/slab.c b/mm/slab.c
index 1f7fd5f51f87..6ebb9515a3e9 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -162,23 +162,6 @@
  */
 static bool pfmemalloc_active __read_mostly;
 
-/* Legal flag mask for kmem_cache_create(). */
-#if DEBUG
-# define CREATE_MASK    (SLAB_RED_ZONE | \
-                         SLAB_POISON | SLAB_HWCACHE_ALIGN | \
-                         SLAB_CACHE_DMA | \
-                         SLAB_STORE_USER | \
-                         SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
-                         SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \
-                         SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK)
-#else
-# define CREATE_MASK    (SLAB_HWCACHE_ALIGN | \
-                         SLAB_CACHE_DMA | \
-                         SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
-                         SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \
-                         SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK)
-#endif
-
 /*
  * kmem_bufctl_t:
  *
@@ -2378,11 +2361,6 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
         if (flags & SLAB_DESTROY_BY_RCU)
                 BUG_ON(flags & SLAB_POISON);
 #endif
-        /*
-         * Always checks flags, a caller might be expecting debug support which
-         * isn't available.
-         */
-        BUG_ON(flags & ~CREATE_MASK);
 
         /*
          * Check that size is in terms of words.  This is needed to avoid
diff --git a/mm/slab.h b/mm/slab.h
index 5a43c2f13621..66a62d3536c6 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -45,6 +45,31 @@ static inline struct kmem_cache *__kmem_cache_alias(const char *name, size_t siz
 #endif
 
 
+/* Legal flag mask for kmem_cache_create(), for various configurations */
+#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
+                         SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS )
+
+#if defined(CONFIG_DEBUG_SLAB)
+#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
+#elif defined(CONFIG_SLUB_DEBUG)
+#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
+                          SLAB_TRACE | SLAB_DEBUG_FREE)
+#else
+#define SLAB_DEBUG_FLAGS (0)
+#endif
+
+#if defined(CONFIG_SLAB)
+#define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
+                          SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | SLAB_NOTRACK)
+#elif defined(CONFIG_SLUB)
+#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
+                          SLAB_TEMPORARY | SLAB_NOTRACK)
+#else
+#define SLAB_CACHE_FLAGS (0)
+#endif
+
+#define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
+
 int __kmem_cache_shutdown(struct kmem_cache *);
 
 struct seq_file;
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 5fb753da6cf0..b705be7faa48 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -109,6 +109,13 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size, size_t align
         if (!kmem_cache_sanity_check(name, size) == 0)
                 goto out_locked;
 
+        /*
+         * Some allocators will constraint the set of valid flags to a subset
+         * of all flags. We expect them to define CACHE_CREATE_MASK in this
+         * case, and we'll just provide them with a sanitized version of the
+         * passed flags.
+         */
+        flags &= CACHE_CREATE_MASK;
 
         s = __kmem_cache_alias(name, size, align, flags, ctor);
         if (s)
diff --git a/mm/slub.c b/mm/slub.c
index deee7c754a7d..b2ada3db4225 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -112,9 +112,6 @@
  *                      the fast path and disables lockless freelists.
  */
 
-#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
-                SLAB_TRACE | SLAB_DEBUG_FREE)
-
 static inline int kmem_cache_debug(struct kmem_cache *s)
 {
 #ifdef CONFIG_SLUB_DEBUG