slab: make usercopy region 32-bit

If kmem case sizes are 32-bit, then usecopy region should be too.

Link: http://lkml.kernel.org/r/20180305200730.15812-21-adobriyan@gmail.com
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/slab.h

@@ -143,7 +143,7 @@ struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
 struct kmem_cache *kmem_cache_create_usercopy(const char *name,
 			unsigned int size, unsigned int align,
 			slab_flags_t flags,
-			size_t useroffset, size_t usersize,
+			unsigned int useroffset, unsigned int usersize,
 			void (*ctor)(void *));
 void kmem_cache_destroy(struct kmem_cache *);
 int kmem_cache_shrink(struct kmem_cache *);

include/linux/slab_def.h

@@ -85,8 +85,8 @@ struct kmem_cache {
 	unsigned int *random_seq;
 #endif
 
-	size_t useroffset;		/* Usercopy region offset */
-	size_t usersize;		/* Usercopy region size */
+	unsigned int useroffset;	/* Usercopy region offset */
+	unsigned int usersize;		/* Usercopy region size */
 
 	struct kmem_cache_node *node[MAX_NUMNODES];
 };

include/linux/slub_def.h

@@ -137,8 +137,8 @@ struct kmem_cache {
 	struct kasan_cache kasan_info;
 #endif
 
-	size_t useroffset;		/* Usercopy region offset */
-	size_t usersize;		/* Usercopy region size */
+	unsigned int useroffset;	/* Usercopy region offset */
+	unsigned int usersize;		/* Usercopy region size */
 
 	struct kmem_cache_node *node[MAX_NUMNODES];
 };

include/net/sock.h

@@ -1114,8 +1114,8 @@ struct proto {
 	struct kmem_cache	*slab;
 	unsigned int		obj_size;
 	slab_flags_t		slab_flags;
-	size_t			useroffset;	/* Usercopy region offset */
-	size_t			usersize;	/* Usercopy region size */
+	unsigned int		useroffset;	/* Usercopy region offset */
+	unsigned int		usersize;	/* Usercopy region size */
 
 	struct percpu_counter	*orphan_count;
 

mm/slab.h

@@ -22,8 +22,8 @@ struct kmem_cache {
 	unsigned int size;	/* The aligned/padded/added on size  */
 	unsigned int align;	/* Alignment as calculated */
 	slab_flags_t flags;	/* Active flags on the slab */
-	size_t useroffset;	/* Usercopy region offset */
-	size_t usersize;	/* Usercopy region size */
+	unsigned int useroffset;/* Usercopy region offset */
+	unsigned int usersize;	/* Usercopy region size */
 	const char *name;	/* Slab name for sysfs */
 	int refcount;		/* Use counter */
 	void (*ctor)(void *);	/* Called on object slot creation */

mm/slab_common.c

@@ -380,8 +380,8 @@ struct kmem_cache *find_mergeable(unsigned int size, unsigned int align,
 
 static struct kmem_cache *create_cache(const char *name,
 		unsigned int object_size, unsigned int size, unsigned int align,
-		slab_flags_t flags, size_t useroffset,
-		size_t usersize, void (*ctor)(void *),
+		slab_flags_t flags, unsigned int useroffset,
+		unsigned int usersize, void (*ctor)(void *),
 		struct mem_cgroup *memcg, struct kmem_cache *root_cache)
 {
 	struct kmem_cache *s;
@@ -454,7 +454,8 @@ out_free_cache:
 struct kmem_cache *
 kmem_cache_create_usercopy(const char *name,
 		  unsigned int size, unsigned int align,
-		  slab_flags_t flags, size_t useroffset, size_t usersize,
+		  slab_flags_t flags,
+		  unsigned int useroffset, unsigned int usersize,
 		  void (*ctor)(void *))
 {
 	struct kmem_cache *s = NULL;

mm/slub.c

@@ -5081,7 +5081,7 @@ SLAB_ATTR_RO(cache_dma);
 
 static ssize_t usersize_show(struct kmem_cache *s, char *buf)
 {
-	return sprintf(buf, "%zu\n", s->usersize);
+	return sprintf(buf, "%u\n", s->usersize);
 }
 SLAB_ATTR_RO(usersize);