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Diffstat (limited to 'drivers/char/tty_io.c')
-rw-r--r--drivers/char/tty_io.c17
1 files changed, 10 insertions, 7 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 18085a20df2..b4f37c65b95 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -2740,18 +2740,21 @@ static int tiocsti(struct tty_struct *tty, char __user *p)
* @tty; tty
* @arg: user buffer for result
*
- * Copies the kernel idea of the window size into the user buffer. No
- * locking is done.
+ * Copies the kernel idea of the window size into the user buffer.
*
- * FIXME: Returning random values racing a window size set is wrong
- * should lock here against that
+ * Locking: tty->termios_sem is taken to ensure the winsize data
+ * is consistent.
*/
static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg)
{
- if (copy_to_user(arg, &tty->winsize, sizeof(*arg)))
- return -EFAULT;
- return 0;
+ int err;
+
+ down(&tty->termios_sem);
+ err = copy_to_user(arg, &tty->winsize, sizeof(*arg));
+ up(&tty->termios_sem);
+
+ return err ? -EFAULT: 0;
}
/**