if (left && !old_left) {
WARN_RATELIMIT(tty->port->itty == NULL,
"scheduling with invalid itty\n");
+ /* see if ldisc has been killed - if so, this means that
+ * even though the ldisc has been halted and ->buf.work
+ * cancelled, ->buf.work is about to be rescheduled
+ */
+ WARN_RATELIMIT(test_bit(TTY_LDISC_HALTED, &tty->flags),
+ "scheduling buffer work for halted ldisc\n");
schedule_work(&tty->port->buf.work);
}
}
* reset_buffer_flags - reset buffer state
* @tty: terminal to reset
*
- * Reset the read buffer counters, clear the flags,
- * and make sure the driver is unthrottled. Called
- * from n_tty_open() and n_tty_flush_buffer().
+ * Reset the read buffer counters and clear the flags.
+ * Called from n_tty_open() and n_tty_flush_buffer().
*
* Locking: tty_read_lock for read fields.
*/
-static void reset_buffer_flags(struct tty_struct *tty)
+static void reset_buffer_flags(struct n_tty_data *ldata)
{
- struct n_tty_data *ldata = tty->disc_data;
unsigned long flags;
raw_spin_lock_irqsave(&ldata->read_lock, flags);
ldata->canon_head = ldata->canon_data = ldata->erasing = 0;
bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
- n_tty_set_room(tty);
+}
+
+static void n_tty_packet_mode_flush(struct tty_struct *tty)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ if (tty->link->packet) {
+ tty->ctrl_status |= TIOCPKT_FLUSHREAD;
+ wake_up_interruptible(&tty->link->read_wait);
+ }
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
}
/**
* n_tty_flush_buffer - clean input queue
* @tty: terminal device
*
- * Flush the input buffer. Called when the line discipline is
- * being closed, when the tty layer wants the buffer flushed (eg
- * at hangup) or when the N_TTY line discipline internally has to
- * clean the pending queue (for example some signals).
+ * Flush the input buffer. Called when the tty layer wants the
+ * buffer flushed (eg at hangup) or when the N_TTY line discipline
+ * internally has to clean the pending queue (for example some signals).
*
* Locking: ctrl_lock, read_lock.
*/
static void n_tty_flush_buffer(struct tty_struct *tty)
{
- unsigned long flags;
- /* clear everything and unthrottle the driver */
- reset_buffer_flags(tty);
-
- if (!tty->link)
- return;
+ reset_buffer_flags(tty->disc_data);
+ n_tty_set_room(tty);
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- if (tty->link->packet) {
- tty->ctrl_status |= TIOCPKT_FLUSHREAD;
- wake_up_interruptible(&tty->link->read_wait);
- }
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ if (tty->link)
+ n_tty_packet_mode_flush(tty);
}
/**
* isig - handle the ISIG optio
* @sig: signal
* @tty: terminal
- * @flush: force flush
*
- * Called when a signal is being sent due to terminal input. This
- * may caus terminal flushing to take place according to the termios
- * settings and character used. Called from the driver receive_buf
- * path so serialized.
+ * Called when a signal is being sent due to terminal input.
+ * Called from the driver receive_buf path so serialized.
*
- * Locking: ctrl_lock, read_lock (both via flush buffer)
+ * Locking: ctrl_lock
*/
-static inline void isig(int sig, struct tty_struct *tty, int flush)
+static inline void isig(int sig, struct tty_struct *tty)
{
- if (tty->pgrp)
- kill_pgrp(tty->pgrp, sig, 1);
- if (flush || !L_NOFLSH(tty)) {
- n_tty_flush_buffer(tty);
- tty_driver_flush_buffer(tty);
+ struct pid *tty_pgrp = tty_get_pgrp(tty);
+ if (tty_pgrp) {
+ kill_pgrp(tty_pgrp, sig, 1);
+ put_pid(tty_pgrp);
}
}
if (I_IGNBRK(tty))
return;
if (I_BRKINT(tty)) {
- isig(SIGINT, tty, 1);
+ isig(SIGINT, tty);
+ if (!L_NOFLSH(tty)) {
+ n_tty_flush_buffer(tty);
+ tty_driver_flush_buffer(tty);
+ }
return;
}
if (I_PARMRK(tty)) {
signal = SIGTSTP;
if (c == SUSP_CHAR(tty)) {
send_signal:
- /*
- * Note that we do not use isig() here because we want
- * the order to be:
- * 1) flush, 2) echo, 3) signal
- */
if (!L_NOFLSH(tty)) {
n_tty_flush_buffer(tty);
tty_driver_flush_buffer(tty);
echo_char(c, tty);
process_echoes(tty);
}
- if (tty->pgrp)
- kill_pgrp(tty->pgrp, signal, 1);
+ isig(signal, tty);
return;
}
}
{
struct n_tty_data *ldata = tty->disc_data;
- n_tty_flush_buffer(tty);
+ if (tty->link)
+ n_tty_packet_mode_flush(tty);
+
kfree(ldata->read_buf);
kfree(ldata->echo_buf);
kfree(ldata);
goto err_free_bufs;
tty->disc_data = ldata;
- reset_buffer_flags(tty);
- tty_unthrottle(tty);
+ reset_buffer_flags(tty->disc_data);
ldata->column = 0;
- n_tty_set_termios(tty, NULL);
tty->minimum_to_wake = 1;
tty->closing = 0;
+ /* indicate buffer work may resume */
+ clear_bit(TTY_LDISC_HALTED, &tty->flags);
+ n_tty_set_termios(tty, NULL);
+ tty_unthrottle(tty);
return 0;
err_free_bufs:
* and if appropriate send any needed signals and return a negative
* error code if action should be taken.
*
- * FIXME:
- * Locking: None - redirected write test is safe, testing
- * current->signal should possibly lock current->sighand
- * pgrp locking ?
+ * Locking: redirected write test is safe
+ * current->signal->tty check is safe
+ * ctrl_lock to safely reference tty->pgrp
*/
static int job_control(struct tty_struct *tty, struct file *file)
/* NOTE: not yet done after every sleep pending a thorough
check of the logic of this change. -- jlc */
/* don't stop on /dev/console */
- if (file->f_op->write != redirected_tty_write &&
- current->signal->tty == tty) {
- if (!tty->pgrp)
- printk(KERN_ERR "n_tty_read: no tty->pgrp!\n");
- else if (task_pgrp(current) != tty->pgrp) {
- if (is_ignored(SIGTTIN) ||
- is_current_pgrp_orphaned())
- return -EIO;
- kill_pgrp(task_pgrp(current), SIGTTIN, 1);
- set_thread_flag(TIF_SIGPENDING);
- return -ERESTARTSYS;
- }
+ if (file->f_op->write == redirected_tty_write ||
+ current->signal->tty != tty)
+ return 0;
+
+ spin_lock_irq(&tty->ctrl_lock);
+ if (!tty->pgrp)
+ printk(KERN_ERR "n_tty_read: no tty->pgrp!\n");
+ else if (task_pgrp(current) != tty->pgrp) {
+ spin_unlock_irq(&tty->ctrl_lock);
+ if (is_ignored(SIGTTIN) || is_current_pgrp_orphaned())
+ return -EIO;
+ kill_pgrp(task_pgrp(current), SIGTTIN, 1);
+ set_thread_flag(TIF_SIGPENDING);
+ return -ERESTARTSYS;
}
+ spin_unlock_irq(&tty->ctrl_lock);
return 0;
}
projects / cascardo / linux.git / blobdiff