diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index b940127ba1c89a..25c9bc7837229a 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -281,7 +281,7 @@ static int pty_resize(struct tty_struct *tty, struct winsize *ws) struct tty_struct *pty = tty->link; /* For a PTY we need to lock the tty side */ - down_write(&tty->termios_rwsem); + mutex_lock(&tty->winsize_mutex); if (!memcmp(ws, &tty->winsize, sizeof(*ws))) goto done; @@ -308,7 +308,7 @@ static int pty_resize(struct tty_struct *tty, struct winsize *ws) tty->winsize = *ws; pty->winsize = *ws; /* Never used so will go away soon */ done: - up_write(&tty->termios_rwsem); + mutex_unlock(&tty->winsize_mutex); return 0; } diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 2174698dd6f722..26bb78c30a0094 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2229,7 +2229,7 @@ static int tiocsti(struct tty_struct *tty, char __user *p) * * Copies the kernel idea of the window size into the user buffer. * - * Locking: tty->termios_rwsem is taken to ensure the winsize data + * Locking: tty->winsize_mutex is taken to ensure the winsize data * is consistent. */ @@ -2237,9 +2237,9 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) { int err; - down_read(&tty->termios_rwsem); + mutex_lock(&tty->winsize_mutex); err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); - up_read(&tty->termios_rwsem); + mutex_unlock(&tty->winsize_mutex); return err ? -EFAULT: 0; } @@ -2260,7 +2260,7 @@ int tty_do_resize(struct tty_struct *tty, struct winsize *ws) unsigned long flags; /* Lock the tty */ - down_write(&tty->termios_rwsem); + mutex_lock(&tty->winsize_mutex); if (!memcmp(ws, &tty->winsize, sizeof(*ws))) goto done; /* Get the PID values and reference them so we can @@ -2275,7 +2275,7 @@ int tty_do_resize(struct tty_struct *tty, struct winsize *ws) tty->winsize = *ws; done: - up_write(&tty->termios_rwsem); + mutex_unlock(&tty->winsize_mutex); return 0; } EXPORT_SYMBOL(tty_do_resize); @@ -3016,6 +3016,7 @@ void initialize_tty_struct(struct tty_struct *tty, mutex_init(&tty->legacy_mutex); mutex_init(&tty->throttle_mutex); init_rwsem(&tty->termios_rwsem); + mutex_init(&tty->winsize_mutex); init_ldsem(&tty->ldisc_sem); init_waitqueue_head(&tty->write_wait); init_waitqueue_head(&tty->read_wait); diff --git a/include/linux/tty.h b/include/linux/tty.h index 554b732d8b555f..64f864651d8696 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -245,6 +245,7 @@ struct tty_struct { struct mutex legacy_mutex; struct mutex throttle_mutex; struct rw_semaphore termios_rwsem; + struct mutex winsize_mutex; spinlock_t ctrl_lock; /* Termios values are protected by the termios rwsem */ struct ktermios termios, termios_locked; @@ -254,7 +255,7 @@ struct tty_struct { struct pid *session; unsigned long flags; int count; - struct winsize winsize; /* termios rwsem */ + struct winsize winsize; /* winsize_mutex */ unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1; unsigned char ctrl_status; /* ctrl_lock */ unsigned int receive_room; /* Bytes free for queue */