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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.c124
1 files changed, 36 insertions, 88 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 66b99a2049e3..a3afa0c387cd 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);
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-06-12 07:09:05 +0200