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path: root/drivers/tty/pty.c
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Diffstat (limited to 'drivers/tty/pty.c')
-rw-r--r--drivers/tty/pty.c49
1 files changed, 24 insertions, 25 deletions
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index b3110040164a..e16a49b507ef 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -263,8 +263,7 @@ static void pty_set_termios(struct tty_struct *tty,
{
/* See if packet mode change of state. */
if (tty->link && tty->link->packet) {
- int extproc = (old_termios->c_lflag & EXTPROC) |
- (tty->termios.c_lflag & EXTPROC);
+ int extproc = (old_termios->c_lflag & EXTPROC) | L_EXTPROC(tty);
int old_flow = ((old_termios->c_iflag & IXON) &&
(old_termios->c_cc[VSTOP] == '\023') &&
(old_termios->c_cc[VSTART] == '\021'));
@@ -406,13 +405,8 @@ static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
if (legacy) {
/* We always use new tty termios data so we can do this
the easy way .. */
- retval = tty_init_termios(tty);
- if (retval)
- goto err_deinit_tty;
-
- retval = tty_init_termios(o_tty);
- if (retval)
- goto err_free_termios;
+ tty_init_termios(tty);
+ tty_init_termios(o_tty);
driver->other->ttys[idx] = o_tty;
driver->ttys[idx] = tty;
@@ -444,12 +438,7 @@ static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
tty->count++;
o_tty->count++;
return 0;
-err_free_termios:
- if (legacy)
- tty_free_termios(tty);
-err_deinit_tty:
- deinitialize_tty_struct(o_tty);
- free_tty_struct(o_tty);
+
err_put_module:
module_put(driver->other->owner);
err:
@@ -666,22 +655,22 @@ static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
return tty;
}
-/* We have no need to install and remove our tty objects as devpts does all
- the work for us */
-
static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
{
return pty_common_install(driver, tty, false);
}
+/* this is called once with whichever end is closed last */
static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
{
-}
+ struct inode *ptmx_inode;
-/* this is called once with whichever end is closed last */
-static void pty_unix98_shutdown(struct tty_struct *tty)
-{
- devpts_kill_index(tty->driver_data, tty->index);
+ if (tty->driver->subtype == PTY_TYPE_MASTER)
+ ptmx_inode = tty->driver_data;
+ else
+ ptmx_inode = tty->link->driver_data;
+ devpts_kill_index(ptmx_inode, tty->index);
+ devpts_del_ref(ptmx_inode);
}
static const struct tty_operations ptm_unix98_ops = {
@@ -697,7 +686,6 @@ static const struct tty_operations ptm_unix98_ops = {
.unthrottle = pty_unthrottle,
.ioctl = pty_unix98_ioctl,
.resize = pty_resize,
- .shutdown = pty_unix98_shutdown,
.cleanup = pty_cleanup
};
@@ -715,7 +703,6 @@ static const struct tty_operations pty_unix98_ops = {
.set_termios = pty_set_termios,
.start = pty_start,
.stop = pty_stop,
- .shutdown = pty_unix98_shutdown,
.cleanup = pty_cleanup,
};
@@ -773,6 +760,18 @@ static int ptmx_open(struct inode *inode, struct file *filp)
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
tty->driver_data = inode;
+ /*
+ * In the case where all references to ptmx inode are dropped and we
+ * still have /dev/tty opened pointing to the master/slave pair (ptmx
+ * is closed/released before /dev/tty), we must make sure that the inode
+ * is still valid when we call the final pty_unix98_shutdown, thus we
+ * hold an additional reference to the ptmx inode. For the same /dev/tty
+ * last close case, we also need to make sure the super_block isn't
+ * destroyed (devpts instance unmounted), before /dev/tty is closed and
+ * on its release devpts_kill_index is called.
+ */
+ devpts_add_ref(inode);
+
tty_add_file(tty, filp);
slave_inode = devpts_pty_new(inode,