Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 38ad2ed0 authored by Paul Fulghum's avatar Paul Fulghum Committed by Linus Torvalds
Browse files

tty: restore locked ioctl file op 



Restore tty locked ioctl handler which was replaced with
an unlocked ioctl handler in hung_up_tty_fops by the patch:

commit e10cc1df
Author: Paul Fulghum <paulkf@microgate.com>
Date:   Thu May 10 22:22:50 2007 -0700

    tty: add compat_ioctl

This was reported in:
[Bug 8473] New: Oops: 0010 [1] SMP

The bug is caused by switching to hung_up_tty_fops in do_tty_hangup.  An
ioctl call can be waiting on BLK after testing for existence of the locked
ioctl handler in the normal tty fops, but before calling the locked ioctl
handler.  If a hangup occurs at that point, the locked ioctl fop is NULL
and an oops occurs.

(akpm: we can remove my debugging code from do_ioctl() now, but it'll be OK to
do that for 2.6.23)

Signed-off-by: default avatarPaul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f4d27817

drivers/char/tty_io.c

+10 −4
Original line number Diff line number Diff line
@@ -1173,7 +1173,13 @@ static unsigned int hung_up_tty_poll(struct file * filp, poll_table * wait) 
	return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM;

}



static long hung_up_tty_ioctl(struct file * file,

static int hung_up_tty_ioctl(struct inode * inode, struct file * file,

			     unsigned int cmd, unsigned long arg)

{

	return cmd == TIOCSPGRP ? -ENOTTY : -EIO;

}



static long hung_up_tty_compat_ioctl(struct file * file,

				     unsigned int cmd, unsigned long arg)

{

	return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
@@ -1222,8 +1228,8 @@ static const struct file_operations hung_up_tty_fops = { 
	.read		= hung_up_tty_read,

	.write		= hung_up_tty_write,

	.poll		= hung_up_tty_poll,

	.unlocked_ioctl = hung_up_tty_ioctl,

	.compat_ioctl	= hung_up_tty_ioctl,

	.ioctl		= hung_up_tty_ioctl,

	.compat_ioctl	= hung_up_tty_compat_ioctl,

	.release	= tty_release,

};