X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=drivers%2Fchar%2Ftty_io.c;h=bf5a00145c0b01796adb5f318b7489828baa7209;hb=e61a1c1c4f240cec61300c8f27518c3e47570fd4;hp=f24c26d2dba116fbbd833eb29a5acf07facddc42;hpb=038c068f63a950c3a6ccfa814831ccac0ad48fb1;p=powerpc.git

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index f24c26d2db..bf5a00145c 100644
--- 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
@@ -935,13 +933,6 @@ restart:
 	if (ld == NULL)
 		return -EINVAL;
 
-	/*
-	 *	No more input please, we are switching. The new ldisc
-	 *	will update this value in the ldisc open function
-	 */
-
-	tty->receive_room = 0;
-
 	/*
 	 *	Problem: What do we do if this blocks ?
 	 */
@@ -953,6 +944,13 @@ restart:
 		return 0;
 	}
 
+	/*
+	 *	No more input please, we are switching. The new ldisc
+	 *	will update this value in the ldisc open function
+	 */
+
+	tty->receive_room = 0;
+
 	o_ldisc = tty->ldisc;
 	o_tty = tty->link;
 
@@ -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;
+	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);
@@ -3704,11 +3724,10 @@ 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) {
@@ -3751,7 +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++)
@@ -3777,8 +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
@@ -3821,30 +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)
@@ -3879,9 +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)();