slub: Check kasprintf results in kmem_cache_init()

Small allocations may fail during slab bringup which is fatal. Add a BUG_ON()
so that we fail immediately rather than failing later during sysfs
processing.
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

mm/slub.c

@@ -3118,9 +3118,12 @@ void __init kmem_cache_init(void)
 	slab_state = UP;
 
 	/* Provide the correct kmalloc names now that the caches are up */
-	for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++)
-		kmalloc_caches[i]. name =
-			kasprintf(GFP_NOWAIT, "kmalloc-%d", 1 << i);
+	for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) {
+		char *s = kasprintf(GFP_NOWAIT, "kmalloc-%d", 1 << i);
+
+		BUG_ON(!s);
+		kmalloc_caches[i].name = s;
+	}
 
 #ifdef CONFIG_SMP
 	register_cpu_notifier(&slab_notifier);