diff options
Diffstat (limited to 'drivers/tty/pty.c')
| -rw-r--r-- | drivers/tty/pty.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index eeae7fafe9a7..5505ffc91da4 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -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)) { |