slub: register slabinfo to procfs

We need to register slabinfo to procfs when CONFIG_SLUB is enabled to
make the file actually visible to user-space.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/proc/proc_misc.c

@@ -451,6 +451,20 @@ static const struct file_operations proc_slabstats_operations = {
 #endif
 #endif
 
+#ifdef CONFIG_SLUB
+static int slabinfo_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &slabinfo_op);
+}
+
+static const struct file_operations proc_slabinfo_operations = {
+	.open		= slabinfo_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+#endif
+
 static int show_stat(struct seq_file *p, void *v)
 {
 	int i;
@@ -733,6 +747,9 @@ void __init proc_misc_init(void)
 #ifdef CONFIG_DEBUG_SLAB_LEAK
 	create_seq_entry("slab_allocators", 0 ,&proc_slabstats_operations);
 #endif
+#endif
+#ifdef CONFIG_SLUB
+	create_seq_entry("slabinfo", S_IWUSR|S_IRUGO, &proc_slabinfo_operations);
 #endif
 	create_seq_entry("buddyinfo",S_IRUGO, &fragmentation_file_operations);
 	create_seq_entry("pagetypeinfo", S_IRUGO, &pagetypeinfo_file_ops);