Merge branch 'master' into gfs2

[pandora-kernel.git] / drivers / char / tty_io.c

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 48b5900..3337417 100644 (file)
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -2065,8 +2065,9 @@ fail_no_mem:
 
        /* call the tty release_mem routine to clean out this slot */
 release_mem_out:
-       printk(KERN_INFO "init_dev: ldisc open failed, "
-                        "clearing slot %d\n", idx);
+       if (printk_ratelimit())
+               printk(KERN_INFO "init_dev: ldisc open failed, "
+                                "clearing slot %d\n", idx);
        release_mem(tty, idx);
        goto end_init;
 }
@@ -2719,6 +2720,8 @@ static int tty_fasync(int fd, struct file * filp, int on)
  *     Locking:
  *             Called functions take tty_ldisc_lock
  *             current->signal->tty check is safe without locks
+ *
+ *     FIXME: may race normal receive processing
  */
 
 static int tiocsti(struct tty_struct *tty, char __user *p)
@@ -2878,9 +2881,7 @@ static int fionbio(struct file *file, int __user *p)
  *     Locking:
  *             Takes tasklist lock internally to walk sessions
  *             Takes task_lock() when updating signal->tty
- *
- *     FIXME: tty_mutex is needed to protect signal->tty references.
- *     FIXME: why task_lock on the signal->tty reference ??
+ *             Takes tty_mutex() to protect tty instance
  *
  */
 
@@ -2915,9 +2916,11 @@ static int tiocsctty(struct tty_struct *tty, int arg)
                } else
                        return -EPERM;
        }
+       mutex_lock(&tty_mutex);
        task_lock(current);
        current->signal->tty = tty;
        task_unlock(current);
+       mutex_unlock(&tty_mutex);
        current->signal->tty_old_pgrp = 0;
        tty->session = current->signal->session;
        tty->pgrp = process_group(current);
@@ -2957,8 +2960,6 @@ static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
  *     permitted where the tty session is our session.
  *
  *     Locking: None
- *
- *     FIXME: current->signal->tty referencing is unsafe.
  */
 
 static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
@@ -3037,19 +3038,20 @@ static int tiocsetd(struct tty_struct *tty, int __user *p)
  *     timed break functionality.
  *
  *     Locking:
- *             None
+ *             atomic_write_lock serializes
  *
- *     FIXME:
- *             What if two overlap
  */
 
 static int send_break(struct tty_struct *tty, unsigned int duration)
 {
+       if (mutex_lock_interruptible(&tty->atomic_write_lock))
+               return -EINTR;
        tty->driver->break_ctl(tty, -1);
        if (!signal_pending(current)) {
                msleep_interruptible(duration);
        }
        tty->driver->break_ctl(tty, 0);
+       mutex_unlock(&tty->atomic_write_lock);
        if (signal_pending(current))
                return -EINTR;
        return 0;
@@ -3142,6 +3144,8 @@ int tty_ioctl(struct inode * inode, struct file * file,
        if (tty_paranoia_check(tty, inode, "tty_ioctl"))
                return -EINVAL;
 
+       /* CHECKME: is this safe as one end closes ? */
+
        real_tty = tty;
        if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
            tty->driver->subtype == PTY_TYPE_MASTER)