1 files changed, 27 insertions, 14 deletions

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 50697a1d6621..231abc8976c5 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -135,9 +135,15 @@ struct mem_cgroup;
 void __init kmem_cache_init(void);
 bool slab_is_available(void);
 
-struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
-			slab_flags_t,
-			void (*)(void *));
+extern bool usercopy_fallback;
+
+struct kmem_cache *kmem_cache_create(const char *name, size_t size,
+			size_t align, slab_flags_t flags,
+			void (*ctor)(void *));
+struct kmem_cache *kmem_cache_create_usercopy(const char *name,
+			size_t size, size_t align, slab_flags_t flags,
+			size_t useroffset, size_t usersize,
+			void (*ctor)(void *));
 void kmem_cache_destroy(struct kmem_cache *);
 int kmem_cache_shrink(struct kmem_cache *);
 
@@ -153,9 +159,20 @@ void memcg_destroy_kmem_caches(struct mem_cgroup *);
  * f.e. add ____cacheline_aligned_in_smp to the struct declaration
  * then the objects will be properly aligned in SMP configurations.
  */
-#define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
-		sizeof(struct __struct), __alignof__(struct __struct),\
-		(__flags), NULL)
+#define KMEM_CACHE(__struct, __flags)					\
+		kmem_cache_create(#__struct, sizeof(struct __struct),	\
+			__alignof__(struct __struct), (__flags), NULL)
+
+/*
+ * To whitelist a single field for copying to/from usercopy, use this
+ * macro instead for KMEM_CACHE() above.
+ */
+#define KMEM_CACHE_USERCOPY(__struct, __flags, __field)			\
+		kmem_cache_create_usercopy(#__struct,			\
+			sizeof(struct __struct),			\
+			__alignof__(struct __struct), (__flags),	\
+			offsetof(struct __struct, __field),		\
+			sizeof_field(struct __struct, __field), NULL)
 
 /*
  * Common kmalloc functions provided by all allocators
@@ -167,15 +184,11 @@ void kzfree(const void *);
 size_t ksize(const void *);
 
 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
-const char *__check_heap_object(const void *ptr, unsigned long n,
-				struct page *page);
+void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
+			bool to_user);
 #else
-static inline const char *__check_heap_object(const void *ptr,
-					      unsigned long n,
-					      struct page *page)
-{
-	return NULL;
-}
+static inline void __check_heap_object(const void *ptr, unsigned long n,
+				       struct page *page, bool to_user) { }
 #endif
 
 /*