Merge branch 'x86/numa' into x86/urgent

[cascardo/linux.git] / drivers / tty / tty_io.c

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index c05c5af..35480dd 100644 (file)
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -559,6 +559,9 @@ void __tty_hangup(struct tty_struct *tty)
 
        tty_lock();
 
+       /* some functions below drop BTM, so we need this bit */
+       set_bit(TTY_HUPPING, &tty->flags);
+
        /* inuse_filps is protected by the single tty lock,
           this really needs to change if we want to flush the
           workqueue with the lock held */
@@ -578,6 +581,10 @@ void __tty_hangup(struct tty_struct *tty)
        }
        spin_unlock(&tty_files_lock);
 
+       /*
+        * it drops BTM and thus races with reopen
+        * we protect the race by TTY_HUPPING
+        */
        tty_ldisc_hangup(tty);
 
        read_lock(&tasklist_lock);
@@ -615,7 +622,6 @@ void __tty_hangup(struct tty_struct *tty)
        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 */
@@ -641,6 +647,7 @@ void __tty_hangup(struct tty_struct *tty)
         * can't yet guarantee all that.
         */
        set_bit(TTY_HUPPED, &tty->flags);
+       clear_bit(TTY_HUPPING, &tty->flags);
        tty_ldisc_enable(tty);
 
        tty_unlock();
@@ -1310,7 +1317,9 @@ static int tty_reopen(struct tty_struct *tty)
 {
        struct tty_driver *driver = tty->driver;
 
-       if (test_bit(TTY_CLOSING, &tty->flags))
+       if (test_bit(TTY_CLOSING, &tty->flags) ||
+                       test_bit(TTY_HUPPING, &tty->flags) ||
+                       test_bit(TTY_LDISC_CHANGING, &tty->flags))
                return -EIO;
 
        if (driver->type == TTY_DRIVER_TYPE_PTY &&