[PATCH] add check to /proc/devices read routines

Patch to add check to get_chrdev_list and get_blkdev_list to prevent reads
of /proc/devices from spilling over the provided page if more than 4096
bytes of string data are generated from all the registered character and
block devices in a system

Signed-off-by: Neil Horman <nhorman@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index af26dc7..01796c4 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -224,7 +224,7 @@
 extern void disk_round_stats(struct gendisk *disk);
 
 /* drivers/block/genhd.c */
-extern int get_blkdev_list(char *);
+extern int get_blkdev_list(char *, int);
 extern void add_disk(struct gendisk *disk);
 extern void del_gendisk(struct gendisk *gp);
 extern void unlink_gendisk(struct gendisk *gp);