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path: root/drivers/char/tty_io.c
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Diffstat (limited to 'drivers/char/tty_io.c')
-rw-r--r--drivers/char/tty_io.c79
1 files changed, 44 insertions, 35 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index e1b46bc7e43..daeb8f76697 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -1161,8 +1161,8 @@ void disassociate_ctty(int on_exit)
tty = get_current_tty();
if (tty) {
tty_pgrp = get_pid(tty->pgrp);
- mutex_unlock(&tty_mutex);
lock_kernel();
+ mutex_unlock(&tty_mutex);
/* XXX: here we race, there is nothing protecting tty */
if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY)
tty_vhangup(tty);
@@ -2496,45 +2496,26 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
}
/**
- * tiocswinsz - implement window size set ioctl
- * @tty; tty
- * @arg: user buffer for result
- *
- * Copies the user idea of the window size to the kernel. Traditionally
- * this is just advisory information but for the Linux console it
- * actually has driver level meaning and triggers a VC resize.
+ * tty_do_resize - resize event
+ * @tty: tty being resized
+ * @real_tty: real tty (not the same as tty if using a pty/tty pair)
+ * @rows: rows (character)
+ * @cols: cols (character)
*
- * Locking:
- * Called function use the console_sem is used to ensure we do
- * not try and resize the console twice at once.
- * The tty->termios_mutex is used to ensure we don't double
- * resize and get confused. Lock order - tty->termios_mutex before
- * console sem
+ * Update the termios variables and send the neccessary signals to
+ * peform a terminal resize correctly
*/
-static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty,
- struct winsize __user *arg)
+int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty,
+ struct winsize *ws)
{
- struct winsize tmp_ws;
struct pid *pgrp, *rpgrp;
unsigned long flags;
- if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
- return -EFAULT;
-
- mutex_lock(&tty->termios_mutex);
- if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg)))
+ /* For a PTY we need to lock the tty side */
+ mutex_lock(&real_tty->termios_mutex);
+ if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
goto done;
-
-#ifdef CONFIG_VT
- if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) {
- if (vc_lock_resize(tty->driver_data, tmp_ws.ws_col,
- tmp_ws.ws_row)) {
- mutex_unlock(&tty->termios_mutex);
- return -ENXIO;
- }
- }
-#endif
/* Get the PID values and reference them so we can
avoid holding the tty ctrl lock while sending signals */
spin_lock_irqsave(&tty->ctrl_lock, flags);
@@ -2550,14 +2531,42 @@ static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty,
put_pid(pgrp);
put_pid(rpgrp);
- tty->winsize = tmp_ws;
- real_tty->winsize = tmp_ws;
+ tty->winsize = *ws;
+ real_tty->winsize = *ws;
done:
- mutex_unlock(&tty->termios_mutex);
+ mutex_unlock(&real_tty->termios_mutex);
return 0;
}
/**
+ * tiocswinsz - implement window size set ioctl
+ * @tty; tty
+ * @arg: user buffer for result
+ *
+ * Copies the user idea of the window size to the kernel. Traditionally
+ * this is just advisory information but for the Linux console it
+ * actually has driver level meaning and triggers a VC resize.
+ *
+ * Locking:
+ * Driver dependant. The default do_resize method takes the
+ * tty termios mutex and ctrl_lock. The console takes its own lock
+ * then calls into the default method.
+ */
+
+static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty,
+ struct winsize __user *arg)
+{
+ struct winsize tmp_ws;
+ if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
+ return -EFAULT;
+
+ if (tty->ops->resize)
+ return tty->ops->resize(tty, real_tty, &tmp_ws);
+ else
+ return tty_do_resize(tty, real_tty, &tmp_ws);
+}
+
+/**
* tioccons - allow admin to move logical console
* @file: the file to become console
*