Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw

[linux-2.6] / drivers / char / tty_io.c

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index df467284ff4e4f267c100c687891766e9d2370ea..389da364e6b6ebb2a70e732927e3e6e92f01243e 100644 (file)
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -1376,6 +1376,8 @@ static void do_tty_hangup(struct work_struct *work)
        read_unlock(&tasklist_lock);
 
        tty->flags = 0;
+       put_pid(tty->session);
+       put_pid(tty->pgrp);
        tty->session = NULL;
        tty->pgrp = NULL;
        tty->ctrl_status = 0;
@@ -1533,7 +1535,7 @@ void disassociate_ctty(int on_exit)
 
        spin_lock_irq(&current->sighand->siglock);
        tty_pgrp = current->signal->tty_old_pgrp;
-       current->signal->tty_old_pgrp = 0;
+       current->signal->tty_old_pgrp = NULL;
        spin_unlock_irq(&current->sighand->siglock);
        put_pid(tty_pgrp);
 
@@ -1901,6 +1903,20 @@ static int init_dev(struct tty_driver *driver, int idx,
        /* check whether we're reopening an existing tty */
        if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
                tty = devpts_get_tty(idx);
+               /*
+                * If we don't have a tty here on a slave open, it's because
+                * the master already started the close process and there's
+                * no relation between devpts file and tty anymore.
+                */
+               if (!tty && driver->subtype == PTY_TYPE_SLAVE) {
+                       retval = -EIO;
+                       goto end_init;
+               }
+               /*
+                * It's safe from now on because init_dev() is called with
+                * tty_mutex held and release_dev() won't change tty->count
+                * or tty->flags without having to grab tty_mutex
+                */
                if (tty && driver->subtype == PTY_TYPE_MASTER)
                        tty = tty->link;
        } else {
@@ -3704,11 +3720,10 @@ int tty_register_driver(struct tty_driver *driver)
        if (driver->flags & TTY_DRIVER_INSTALLED)
                return 0;
 
-       if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
-               p = kmalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL);
+       if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) {
+               p = kzalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL);
                if (!p)
                        return -ENOMEM;
-               memset(p, 0, driver->num * 3 * sizeof(void *));
        }
 
        if (!driver->major) {
@@ -3827,6 +3842,9 @@ static struct pid *__proc_set_tty(struct task_struct *tsk, struct tty_struct *tt
 {
        struct pid *old_pgrp;
        if (tty) {
+               /* We should not have a session or pgrp to here but.... */
+               put_pid(tty->session);
+               put_pid(tty->pgrp);
                tty->session = get_pid(task_session(tsk));
                tty->pgrp = get_pid(task_pgrp(tsk));
        }