Merge master.kernel.org:/pub/scm/linux/kernel/git/herbert/crypto-2.6

[linux-drm-fsl-dcu.git] / drivers / char / tty_io.c

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 5289254e7ab3f1e0d0fdfbf48e411e07fdc9c31a..7710a6a77d971351cd053c2dc6dbb736383a2204 100644 (file)
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -141,8 +141,6 @@ static DECLARE_MUTEX(allocated_ptys_lock);
 static int ptmx_open(struct inode *, struct file *);
 #endif
 
-extern void disable_early_printk(void);
-
 static void initialize_tty_struct(struct tty_struct *tty);
 
 static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
@@ -155,8 +153,8 @@ int tty_ioctl(struct inode * inode, struct file * file,
              unsigned int cmd, unsigned long arg);
 static int tty_fasync(int fd, struct file * filp, int on);
 static void release_tty(struct tty_struct *tty, int idx);
-static struct pid *__proc_set_tty(struct task_struct *tsk,
-                               struct tty_struct *tty);
+static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
+static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
 
 /**
  *     alloc_tty_struct        -       allocate a tty object
@@ -1376,6 +1374,8 @@ 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;
@@ -1532,10 +1532,9 @@ 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;
+       put_pid(current->signal->tty_old_pgrp);
+       current->signal->tty_old_pgrp = NULL;
        spin_unlock_irq(&current->sighand->siglock);
-       put_pid(tty_pgrp);
 
        mutex_lock(&tty_mutex);
        /* It is possible that do_tty_hangup has free'd this tty */
@@ -1560,6 +1559,18 @@ void disassociate_ctty(int on_exit)
        unlock_kernel();
 }
 
+/**
+ *
+ *     no_tty  - Ensure the current process does not have a controlling tty
+ */
+void no_tty(void)
+{
+       struct task_struct *tsk = current;
+       if (tsk->signal->leader)
+               disassociate_ctty(0);
+       proc_clear_tty(tsk);
+}
+
 
 /**
  *     stop_tty        -       propogate flow control
@@ -1901,6 +1912,20 @@ 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 {
@@ -2492,7 +2517,6 @@ static int tty_open(struct inode * inode, struct file * filp)
        int index;
        dev_t device = inode->i_rdev;
        unsigned short saved_flags = filp->f_flags;
-       struct pid *old_pgrp;
 
        nonseekable_open(inode, filp);
        
@@ -2586,17 +2610,15 @@ got_driver:
                goto retry_open;
        }
 
-       old_pgrp = NULL;
        mutex_lock(&tty_mutex);
        spin_lock_irq(&current->sighand->siglock);
        if (!noctty &&
            current->signal->leader &&
            !current->signal->tty &&
            tty->session == NULL)
-               old_pgrp = __proc_set_tty(current, tty);
+               __proc_set_tty(current, tty);
        spin_unlock_irq(&current->sighand->siglock);
        mutex_unlock(&tty_mutex);
-       put_pid(old_pgrp);
        return 0;
 }
 
@@ -3271,9 +3293,7 @@ int tty_ioctl(struct inode * inode, struct file * file,
                case TIOCNOTTY:
                        if (current->signal->tty != tty)
                                return -ENOTTY;
-                       if (current->signal->leader)
-                               disassociate_ctty(0);
-                       proc_clear_tty(current);
+                       no_tty();
                        return 0;
                case TIOCSCTTY:
                        return tiocsctty(tty, arg);
@@ -3704,24 +3724,22 @@ 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) {
                error = alloc_chrdev_region(&dev, driver->minor_start, driver->num,
-                                               (char*)driver->name);
+                                               driver->name);
                if (!error) {
                        driver->major = MAJOR(dev);
                        driver->minor_start = MINOR(dev);
                }
        } else {
                dev = MKDEV(driver->major, driver->minor_start);
-               error = register_chrdev_region(dev, driver->num,
-                                               (char*)driver->name);
+               error = register_chrdev_region(dev, driver->num, driver->name);
        }
        if (error < 0) {
                kfree(p);
@@ -3752,7 +3770,9 @@ int tty_register_driver(struct tty_driver *driver)
        if (!driver->put_char)
                driver->put_char = tty_default_put_char;
        
+       mutex_lock(&tty_mutex);
        list_add(&driver->tty_drivers, &tty_drivers);
+       mutex_unlock(&tty_mutex);
        
        if ( !(driver->flags & TTY_DRIVER_DYNAMIC_DEV) ) {
                for(i = 0; i < driver->num; i++)
@@ -3778,8 +3798,9 @@ int tty_unregister_driver(struct tty_driver *driver)
 
        unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
                                driver->num);
-
+       mutex_lock(&tty_mutex);
        list_del(&driver->tty_drivers);
+       mutex_unlock(&tty_mutex);
 
        /*
         * Free the termios and termios_locked structures because
@@ -3822,30 +3843,26 @@ void proc_clear_tty(struct task_struct *p)
        p->signal->tty = NULL;
        spin_unlock_irq(&p->sighand->siglock);
 }
-EXPORT_SYMBOL(proc_clear_tty);
 
-static struct pid *__proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
+static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
 {
-       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));
        }
-       old_pgrp = tsk->signal->tty_old_pgrp;
+       put_pid(tsk->signal->tty_old_pgrp);
        tsk->signal->tty = tty;
        tsk->signal->tty_old_pgrp = NULL;
-       return old_pgrp;
 }
 
-void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
+static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
 {
-       struct pid *old_pgrp;
-
        spin_lock_irq(&tsk->sighand->siglock);
-       old_pgrp = __proc_set_tty(tsk, tty);
+       __proc_set_tty(tsk, tty);
        spin_unlock_irq(&tsk->sighand->siglock);
-
-       put_pid(old_pgrp);
 }
 
 struct tty_struct *get_current_tty(void)
@@ -3880,9 +3897,6 @@ void __init console_init(void)
         * set up the console device so that later boot sequences can 
         * inform about problems etc..
         */
-#ifdef CONFIG_EARLY_PRINTK
-       disable_early_printk();
-#endif
        call = __con_initcall_start;
        while (call < __con_initcall_end) {
                (*call)();