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Commit d739e65b authored by Alan Cox's avatar Alan Cox Committed by Greg Kroah-Hartman
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pty: Lock the devpts bits privately 



This is a private pty affair, we don't want to tangle it with the tty_lock
any more as we know all the other non tty locking is now handled by the vfs
so we too can move.

Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3af502b9

drivers/tty/pty.c

+15 −4
Original line number Diff line number Diff line
@@ -26,11 +26,13 @@ 
#include <linux/bitops.h>

#include <linux/devpts_fs.h>

#include <linux/slab.h>

#include <linux/mutex.h>





#ifdef CONFIG_UNIX98_PTYS

static struct tty_driver *ptm_driver;

static struct tty_driver *pts_driver;

static DEFINE_MUTEX(devpts_mutex);

#endif



static void pty_close(struct tty_struct *tty, struct file *filp)
@@ -54,8 +56,11 @@ static void pty_close(struct tty_struct *tty, struct file *filp) 
	if (tty->driver->subtype == PTY_TYPE_MASTER) {

		set_bit(TTY_OTHER_CLOSED, &tty->flags);

#ifdef CONFIG_UNIX98_PTYS

		if (tty->driver == ptm_driver)

		if (tty->driver == ptm_driver) {

		        mutex_lock(&devpts_mutex);

			devpts_pty_kill(tty->link);

		        mutex_unlock(&devpts_mutex);

		}

#endif

		tty_unlock();

		tty_vhangup(tty->link);
@@ -475,13 +480,17 @@ static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, 
 *	@idx: tty index

 *

 *	Look up a pty master device. Called under the tty_mutex for now.

 *	This provides our locking.

 *	This provides our locking for the tty pointer.

 */



static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,

		struct inode *pts_inode, int idx)

{

	struct tty_struct *tty = devpts_get_tty(pts_inode, idx);

	struct tty_struct *tty;



	mutex_lock(&devpts_mutex);

	tty = devpts_get_tty(pts_inode, idx);

	mutex_unlock(&devpts_mutex);

	/* Master must be open before slave */

	if (!tty)

		return ERR_PTR(-EIO);
@@ -622,8 +631,10 @@ static int ptmx_open(struct inode *inode, struct file *filp) 
	}



	mutex_lock(&tty_mutex);

	tty_lock();

	mutex_lock(&devpts_mutex);

	tty = tty_init_dev(ptm_driver, index);

	mutex_unlock(&devpts_mutex);

	tty_lock();

	mutex_unlock(&tty_mutex);



	if (IS_ERR(tty)) {