diff options
Diffstat (limited to 'drivers/char/tty_io.c')
-rw-r--r-- | drivers/char/tty_io.c | 124 |
1 files changed, 36 insertions, 88 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 66b99a2049e..a3afa0c387c 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -295,7 +295,7 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line) struct tty_driver *p, *res = NULL; int tty_line = 0; int len; - char *str; + char *str, *stp; for (str = name; *str; str++) if ((*str >= '0' && *str <= '9') || *str == ',') @@ -311,13 +311,14 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line) list_for_each_entry(p, &tty_drivers, tty_drivers) { if (strncmp(name, p->name, len) != 0) continue; - if (*str == ',') - str++; - if (*str == '\0') - str = NULL; + stp = str; + if (*stp == ',') + stp++; + if (*stp == '\0') + stp = NULL; if (tty_line >= 0 && tty_line <= p->num && p->ops && - p->ops->poll_init && !p->ops->poll_init(p, tty_line, str)) { + p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { res = tty_driver_kref_get(p); *line = tty_line; break; @@ -470,43 +471,6 @@ void tty_wakeup(struct tty_struct *tty) EXPORT_SYMBOL_GPL(tty_wakeup); /** - * tty_ldisc_flush - flush line discipline queue - * @tty: tty - * - * Flush the line discipline queue (if any) for this tty. If there - * is no line discipline active this is a no-op. - */ - -void tty_ldisc_flush(struct tty_struct *tty) -{ - struct tty_ldisc *ld = tty_ldisc_ref(tty); - if (ld) { - if (ld->ops->flush_buffer) - ld->ops->flush_buffer(tty); - tty_ldisc_deref(ld); - } - tty_buffer_flush(tty); -} - -EXPORT_SYMBOL_GPL(tty_ldisc_flush); - -/** - * tty_reset_termios - reset terminal state - * @tty: tty to reset - * - * Restore a terminal to the driver default state - */ - -static void tty_reset_termios(struct tty_struct *tty) -{ - mutex_lock(&tty->termios_mutex); - *tty->termios = tty->driver->init_termios; - tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); - tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); - mutex_unlock(&tty->termios_mutex); -} - -/** * do_tty_hangup - actual handler for hangup events * @work: tty device * @@ -535,7 +499,6 @@ static void do_tty_hangup(struct work_struct *work) struct file *cons_filp = NULL; struct file *filp, *f = NULL; struct task_struct *p; - struct tty_ldisc *ld; int closecount = 0, n; unsigned long flags; int refs = 0; @@ -566,40 +529,8 @@ static void do_tty_hangup(struct work_struct *work) filp->f_op = &hung_up_tty_fops; } file_list_unlock(); - /* - * FIXME! What are the locking issues here? This may me overdoing - * things... This question is especially important now that we've - * removed the irqlock. - */ - ld = tty_ldisc_ref(tty); - if (ld != NULL) { - /* We may have no line discipline at this point */ - if (ld->ops->flush_buffer) - ld->ops->flush_buffer(tty); - tty_driver_flush_buffer(tty); - if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) && - ld->ops->write_wakeup) - ld->ops->write_wakeup(tty); - if (ld->ops->hangup) - ld->ops->hangup(tty); - } - /* - * FIXME: Once we trust the LDISC code better we can wait here for - * ldisc completion and fix the driver call race - */ - wake_up_interruptible_poll(&tty->write_wait, POLLOUT); - wake_up_interruptible_poll(&tty->read_wait, POLLIN); - /* - * Shutdown the current line discipline, and reset it to - * N_TTY. - */ - if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) - tty_reset_termios(tty); - /* Defer ldisc switch */ - /* tty_deferred_ldisc_switch(N_TTY); - This should get done automatically when the port closes and - tty_release is called */ + tty_ldisc_hangup(tty); read_lock(&tasklist_lock); if (tty->session) { @@ -628,12 +559,15 @@ static void do_tty_hangup(struct work_struct *work) read_unlock(&tasklist_lock); spin_lock_irqsave(&tty->ctrl_lock, flags); - tty->flags = 0; + clear_bit(TTY_THROTTLED, &tty->flags); + clear_bit(TTY_PUSH, &tty->flags); + clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); put_pid(tty->session); put_pid(tty->pgrp); tty->session = NULL; tty->pgrp = NULL; tty->ctrl_status = 0; + set_bit(TTY_HUPPED, &tty->flags); spin_unlock_irqrestore(&tty->ctrl_lock, flags); /* Account for the p->signal references we killed */ @@ -659,10 +593,7 @@ static void do_tty_hangup(struct work_struct *work) * can't yet guarantee all that. */ set_bit(TTY_HUPPED, &tty->flags); - if (ld) { - tty_ldisc_enable(tty); - tty_ldisc_deref(ld); - } + tty_ldisc_enable(tty); unlock_kernel(); if (f) fput(f); @@ -1332,7 +1263,9 @@ static int tty_reopen(struct tty_struct *tty) tty->count++; tty->driver = driver; /* N.B. why do this every time?? */ + mutex_lock(&tty->ldisc_mutex); WARN_ON(!test_bit(TTY_LDISC, &tty->flags)); + mutex_unlock(&tty->ldisc_mutex); return 0; } @@ -2480,6 +2413,24 @@ static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int return tty->ops->tiocmset(tty, file, set, clear); } +struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) +{ + if (tty->driver->type == TTY_DRIVER_TYPE_PTY && + tty->driver->subtype == PTY_TYPE_MASTER) + tty = tty->link; + return tty; +} +EXPORT_SYMBOL(tty_pair_get_tty); + +struct tty_struct *tty_pair_get_pty(struct tty_struct *tty) +{ + if (tty->driver->type == TTY_DRIVER_TYPE_PTY && + tty->driver->subtype == PTY_TYPE_MASTER) + return tty; + return tty->link; +} +EXPORT_SYMBOL(tty_pair_get_pty); + /* * Split this up, as gcc can choke on it otherwise.. */ @@ -2495,11 +2446,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (tty_paranoia_check(tty, inode, "tty_ioctl")) return -EINVAL; - real_tty = tty; - if (tty->driver->type == TTY_DRIVER_TYPE_PTY && - tty->driver->subtype == PTY_TYPE_MASTER) - real_tty = tty->link; - + real_tty = tty_pair_get_tty(tty); /* * Factor out some common prep work @@ -2555,7 +2502,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case TIOCGSID: return tiocgsid(tty, real_tty, p); case TIOCGETD: - return put_user(tty->ldisc.ops->num, (int __user *)p); + return put_user(tty->ldisc->ops->num, (int __user *)p); case TIOCSETD: return tiocsetd(tty, p); /* @@ -2770,6 +2717,7 @@ void initialize_tty_struct(struct tty_struct *tty, tty->buf.head = tty->buf.tail = NULL; tty_buffer_init(tty); mutex_init(&tty->termios_mutex); + mutex_init(&tty->ldisc_mutex); init_waitqueue_head(&tty->write_wait); init_waitqueue_head(&tty->read_wait); INIT_WORK(&tty->hangup_work, do_tty_hangup); |