Driver-Core: extend devnode callbacks to provide permissions

This allows subsytems to provide devtmpfs with non-default permissions
for the device node. Instead of the default mode of 0600, null, zero,
random, urandom, full, tty, ptmx now have a mode of 0666, which allows
non-privileged processes to access standard device nodes in case no
other userspace process applies the expected permissions.

This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index a3afa0c..c70d9da 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -3056,11 +3056,22 @@
 	}
 }
 
+static char *tty_devnode(struct device *dev, mode_t *mode)
+{
+	if (!mode)
+		return NULL;
+	if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) ||
+	    dev->devt == MKDEV(TTYAUX_MAJOR, 2))
+		*mode = 0666;
+	return NULL;
+}
+
 static int __init tty_class_init(void)
 {
 	tty_class = class_create(THIS_MODULE, "tty");
 	if (IS_ERR(tty_class))
 		return PTR_ERR(tty_class);
+	tty_class->devnode = tty_devnode;
 	return 0;
 }