slub: make ->size unsigned int

Linux doesn't support negative length objects (including meta data).

Link: http://lkml.kernel.org/r/20180305200730.15812-18-adobriyan@gmail.comSigned-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: 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/slub_def.h

@@ -84,7 +84,7 @@ struct kmem_cache {
 	/* Used for retriving partial slabs etc */
 	slab_flags_t flags;
 	unsigned long min_partial;
-	int size;		/* The size of an object including meta data */
+	unsigned int size;	/* The size of an object including meta data */
 	unsigned int object_size;/* The size of an object without meta data */
 	unsigned int offset;	/* Free pointer offset. */
 #ifdef CONFIG_SLUB_CPU_PARTIAL

mm/slub.c

@@ -2399,7 +2399,7 @@ slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
 
 	pr_warn("SLUB: Unable to allocate memory on node %d, gfp=%#x(%pGg)\n",
 		nid, gfpflags, &gfpflags);
-	pr_warn("  cache: %s, object size: %u, buffer size: %d, default order: %d, min order: %d\n",
+	pr_warn("  cache: %s, object size: %u, buffer size: %u, default order: %d, min order: %d\n",
 		s->name, s->object_size, s->size, oo_order(s->oo),
 		oo_order(s->min));
 
@@ -3633,8 +3633,8 @@ static int kmem_cache_open(struct kmem_cache *s, slab_flags_t flags)
 	free_kmem_cache_nodes(s);
 error:
 	if (flags & SLAB_PANIC)
-		panic("Cannot create slab %s size=%lu realsize=%u order=%u offset=%u flags=%lx\n",
-		      s->name, (unsigned long)s->size, s->size,
+		panic("Cannot create slab %s size=%u realsize=%u order=%u offset=%u flags=%lx\n",
+		      s->name, s->size, s->size,
 		      oo_order(s->oo), s->offset, (unsigned long)flags);
 	return -EINVAL;
 }
@@ -3825,7 +3825,7 @@ void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
 			 bool to_user)
 {
 	struct kmem_cache *s;
-	unsigned long offset;
+	unsigned int offset;
 	size_t object_size;
 
 	/* Find object and usable object size. */
@@ -4889,7 +4889,7 @@ struct slab_attribute {
 
 static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
 {
-	return sprintf(buf, "%d\n", s->size);
+	return sprintf(buf, "%u\n", s->size);
 }
 SLAB_ATTR_RO(slab_size);
 
@@ -5664,7 +5664,7 @@ static char *create_unique_id(struct kmem_cache *s)
 		*p++ = 'A';
 	if (p != name + 1)
 		*p++ = '-';
-	p += sprintf(p, "%07d", s->size);
+	p += sprintf(p, "%07u", s->size);
 
 	BUG_ON(p > name + ID_STR_LENGTH - 1);
 	return name;