On Thu, 14 Jun 2007 10:42:23 +0000 Dave Young <hidave.darkstar@gmail.com> wrote:
Right, thanks. This should repair it:
From: Paul Fulghum <paulkf@microgate.com>
Restore tty locked ioctl handler which was replaced with
an unlocked ioctl handler in hung_up_tty_fops by the patch:
commit e10cc1df1d2014f68a4bdcf73f6dd122c4561f94
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: Paul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
drivers/char/tty_io.c | 14 ++++++++++----
1 files changed, 10 insertions(+), 4 deletions(-)
diff -puN drivers/char/tty_io.c~tty-restore-locked-ioctl-file-op drivers/char/tty_io.c
--- a/drivers/char/tty_io.c~tty-restore-locked-ioctl-file-op
+++ a/drivers/char/tty_io.c
@@ -1173,8 +1173,14 @@ static unsigned int hung_up_tty_poll(str
return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM;
}
-static long hung_up_tty_ioctl(struct file * file,
- unsigned int cmd, unsigned long arg)
+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
.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,
};
_
-
