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[PATCH] tty: lock ticogwinsz

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Now we lock the set ioctl its trivial to lock the get one so the data
copied is consistent.  At the moment we have the BKL here but this removes
the need for it and is a step in the right direction

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Alan Cox 2006-09-29 02:00:40 -07:00 committed by Linus Torvalds
parent 1266b1e1ae
commit 808a0d389f
1 changed files with 10 additions and 7 deletions
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17
drivers/char/tty_io.c
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@ -2740,18 +2740,21 @@ static int tiocsti(struct tty_struct *tty, char __user *p)
* @tty; tty * @tty; tty
* @arg: user buffer for result * @arg: user buffer for result
* *
* Copies the kernel idea of the window size into the user buffer. No * Copies the kernel idea of the window size into the user buffer.
* locking is done.
* *
* FIXME: Returning random values racing a window size set is wrong * Locking: tty->termios_sem is taken to ensure the winsize data
* should lock here against that * is consistent.
*/ */
static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg) static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg)
{ {
if (copy_to_user(arg, &tty->winsize, sizeof(*arg))) int err;
return -EFAULT;
return 0; down(&tty->termios_sem);
err = copy_to_user(arg, &tty->winsize, sizeof(*arg));
up(&tty->termios_sem);
return err ? -EFAULT: 0;
} }
/** /**