X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fchar%2Ftty_io.c;h=52bd25904b2a0263bb807b882c54c2e3b840f0d2;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=d70a259953f3d4ff4a36a8bf3ce772b1ff535b4b;hpb=7172c64a7cee4dfa95864f49c914f7ea8cf497c8;p=linux-2.6.git

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index d70a25995..52bd25904 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -103,20 +103,22 @@
 #include <linux/selection.h>
 
 #include <linux/kmod.h>
-#include <linux/vs_cvirt.h>
+#include <linux/vs_pid.h>
 
 #undef TTY_DEBUG_HANGUP
 
 #define TTY_PARANOIA_CHECK 1
 #define CHECK_TTY_COUNT 1
 
-struct termios tty_std_termios = {	/* for the benefit of tty drivers  */
+struct ktermios tty_std_termios = {	/* for the benefit of tty drivers  */
 	.c_iflag = ICRNL | IXON,
 	.c_oflag = OPOST | ONLCR,
 	.c_cflag = B38400 | CS8 | CREAD | HUPCL,
 	.c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK |
 		   ECHOCTL | ECHOKE | IEXTEN,
-	.c_cc = INIT_C_CC
+	.c_cc = INIT_C_CC,
+	.c_ispeed = 38400,
+	.c_ospeed = 38400
 };
 
 EXPORT_SYMBOL(tty_std_termios);
@@ -184,6 +186,7 @@ static inline void free_tty_struct(struct tty_struct *tty)
 {
 	kfree(tty->write_buf);
 	tty_buffer_free_all(tty);
+	memset(tty, 0xDEADDEAD, sizeof(struct tty_struct));
 	kfree(tty);
 }
 
@@ -1240,10 +1243,26 @@ void tty_ldisc_flush(struct tty_struct *tty)
 }
 
 EXPORT_SYMBOL_GPL(tty_ldisc_flush);
+
+/**
+ *	tty_reset_termios	-	reset terminal state
+ *	@tty: tty to reset
+ *
+ *	Restore a terminal to the driver default state
+ */
+
+static void tty_reset_termios(struct tty_struct *tty)
+{
+	mutex_lock(&tty->termios_mutex);
+	*tty->termios = tty->driver->init_termios;
+	tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
+	tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
+	mutex_unlock(&tty->termios_mutex);
+}
 	
 /**
  *	do_tty_hangup		-	actual handler for hangup events
- *	@data: tty device
+ *	@work: tty device
  *
  *	This can be called by the "eventd" kernel thread.  That is process
  *	synchronous but doesn't hold any locks, so we need to make sure we
@@ -1263,9 +1282,10 @@ EXPORT_SYMBOL_GPL(tty_ldisc_flush);
  *		  tasklist_lock to walk task list for hangup event
  *		    ->siglock to protect ->signal/->sighand
  */
-static void do_tty_hangup(void *data)
+static void do_tty_hangup(struct work_struct *work)
 {
-	struct tty_struct *tty = (struct tty_struct *) data;
+	struct tty_struct *tty =
+		container_of(work, struct tty_struct, hangup_work);
 	struct file * cons_filp = NULL;
 	struct file *filp, *f = NULL;
 	struct task_struct *p;
@@ -1327,11 +1347,7 @@ static void do_tty_hangup(void *data)
 	 * N_TTY.
 	 */
 	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
-	{
-		mutex_lock(&tty->termios_mutex);
-		*tty->termios = tty->driver->init_termios;
-		mutex_unlock(&tty->termios_mutex);
-	}
+		tty_reset_termios(tty);
 	
 	/* Defer ldisc switch */
 	/* tty_deferred_ldisc_switch(N_TTY);
@@ -1426,7 +1442,7 @@ void tty_vhangup(struct tty_struct * tty)
 
 	printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf));
 #endif
-	do_tty_hangup((void *) tty);
+	do_tty_hangup(&tty->hangup_work);
 }
 EXPORT_SYMBOL(tty_vhangup);
 
@@ -1511,7 +1527,7 @@ void disassociate_ctty(int on_exit)
 
 	spin_lock_irq(&current->sighand->siglock);
 	current->signal->tty_old_pgrp = 0;
-	session = current->signal->session;
+	session = process_session(current);
 	spin_unlock_irq(&current->sighand->siglock);
 
 	mutex_lock(&tty_mutex);
@@ -1629,7 +1645,7 @@ static ssize_t tty_read(struct file * file, char __user * buf, size_t count,
 	struct tty_ldisc *ld;
 
 	tty = (struct tty_struct *)file->private_data;
-	inode = file->f_dentry->d_inode;
+	inode = file->f_path.dentry->d_inode;
 	if (tty_paranoia_check(tty, inode, "tty_read"))
 		return -EIO;
 	if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags)))
@@ -1732,7 +1748,7 @@ static inline ssize_t do_tty_write(
 		cond_resched();
 	}
 	if (written) {
-		struct inode *inode = file->f_dentry->d_inode;
+		struct inode *inode = file->f_path.dentry->d_inode;
 		inode->i_mtime = current_fs_time(inode->i_sb);
 		ret = written;
 	}
@@ -1763,7 +1779,7 @@ static ssize_t tty_write(struct file * file, const char __user * buf, size_t cou
 			 loff_t *ppos)
 {
 	struct tty_struct * tty;
-	struct inode *inode = file->f_dentry->d_inode;
+	struct inode *inode = file->f_path.dentry->d_inode;
 	ssize_t ret;
 	struct tty_ldisc *ld;
 	
@@ -1870,13 +1886,27 @@ static int init_dev(struct tty_driver *driver, int idx,
 	struct tty_struct **ret_tty)
 {
 	struct tty_struct *tty, *o_tty;
-	struct termios *tp, **tp_loc, *o_tp, **o_tp_loc;
-	struct termios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc;
+	struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc;
+	struct ktermios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc;
 	int retval = 0;
 
 	/* 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 {
@@ -1918,7 +1948,7 @@ static int init_dev(struct tty_driver *driver, int idx,
 	}
 
 	if (!*tp_loc) {
-		tp = (struct termios *) kmalloc(sizeof(struct termios),
+		tp = (struct ktermios *) kmalloc(sizeof(struct ktermios),
 						GFP_KERNEL);
 		if (!tp)
 			goto free_mem_out;
@@ -1926,11 +1956,11 @@ static int init_dev(struct tty_driver *driver, int idx,
 	}
 
 	if (!*ltp_loc) {
-		ltp = (struct termios *) kmalloc(sizeof(struct termios),
+		ltp = (struct ktermios *) kmalloc(sizeof(struct ktermios),
 						 GFP_KERNEL);
 		if (!ltp)
 			goto free_mem_out;
-		memset(ltp, 0, sizeof(struct termios));
+		memset(ltp, 0, sizeof(struct ktermios));
 	}
 
 	if (driver->type == TTY_DRIVER_TYPE_PTY) {
@@ -1951,19 +1981,19 @@ static int init_dev(struct tty_driver *driver, int idx,
 		}
 
 		if (!*o_tp_loc) {
-			o_tp = (struct termios *)
-				kmalloc(sizeof(struct termios), GFP_KERNEL);
+			o_tp = (struct ktermios *)
+				kmalloc(sizeof(struct ktermios), GFP_KERNEL);
 			if (!o_tp)
 				goto free_mem_out;
 			*o_tp = driver->other->init_termios;
 		}
 
 		if (!*o_ltp_loc) {
-			o_ltp = (struct termios *)
-				kmalloc(sizeof(struct termios), GFP_KERNEL);
+			o_ltp = (struct ktermios *)
+				kmalloc(sizeof(struct ktermios), GFP_KERNEL);
 			if (!o_ltp)
 				goto free_mem_out;
-			memset(o_ltp, 0, sizeof(struct termios));
+			memset(o_ltp, 0, sizeof(struct ktermios));
 		}
 
 		/*
@@ -2002,6 +2032,9 @@ static int init_dev(struct tty_driver *driver, int idx,
 		*ltp_loc = ltp;
 	tty->termios = *tp_loc;
 	tty->termios_locked = *ltp_loc;
+	/* Compatibility until drivers always set this */
+	tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
+	tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
 	driver->refcount++;
 	tty->count++;
 
@@ -2080,8 +2113,9 @@ 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;
 }
@@ -2103,7 +2137,7 @@ release_mem_out:
 static void release_mem(struct tty_struct *tty, int idx)
 {
 	struct tty_struct *o_tty;
-	struct termios *tp;
+	struct ktermios *tp;
 	int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM;
 
 	if ((o_tty = tty->link) != NULL) {
@@ -2169,7 +2203,7 @@ static void release_dev(struct file * filp)
 	unsigned long flags;
 	
 	tty = (struct tty_struct *)filp->private_data;
-	if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "release_dev"))
+	if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "release_dev"))
 		return;
 
 	check_tty_count(tty, "release_dev");
@@ -2679,7 +2713,7 @@ static unsigned int tty_poll(struct file * filp, poll_table * wait)
 	int ret = 0;
 
 	tty = (struct tty_struct *)filp->private_data;
-	if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_poll"))
+	if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll"))
 		return 0;
 		
 	ld = tty_ldisc_ref_wait(tty);
@@ -2695,7 +2729,7 @@ static int tty_fasync(int fd, struct file * filp, int on)
 	int retval;
 
 	tty = (struct tty_struct *)filp->private_data;
-	if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_fasync"))
+	if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync"))
 		return 0;
 	
 	retval = fasync_helper(fd, filp, on, &tty->fasync);
@@ -2896,7 +2930,7 @@ static int tiocsctty(struct tty_struct *tty, int arg)
 {
 	int ret = 0;
 	if (current->signal->leader &&
-	    (current->signal->session == tty->session))
+			(process_session(current) == tty->session))
 		return ret;
 
 	mutex_lock(&tty_mutex);
@@ -2981,7 +3015,7 @@ static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
 		return retval;
 	if (!current->signal->tty ||
 	    (current->signal->tty != real_tty) ||
-	    (real_tty->session != current->signal->session))
+	    (real_tty->session != process_session(current)))
 		return -ENOTTY;
 	if (get_user(pgrp, p))
 		return -EFAULT;
@@ -2989,7 +3023,7 @@ static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
 	pgrp = vx_rmap_pid(pgrp);
 	if (pgrp < 0)
 		return -EINVAL;
-	if (session_of_pgrp(pgrp) != current->signal->session)
+	if (session_of_pgrp(pgrp) != process_session(current))
 		return -EPERM;
 	real_tty->pgrp = pgrp;
 	return 0;
@@ -3311,28 +3345,24 @@ int tty_ioctl(struct inode * inode, struct file * file,
  * Nasty bug: do_SAK is being called in interrupt context.  This can
  * deadlock.  We punt it up to process context.  AKPM - 16Mar2001
  */
-static void __do_SAK(void *arg)
+static void __do_SAK(struct work_struct *work)
 {
+	struct tty_struct *tty =
+		container_of(work, struct tty_struct, SAK_work);
 #ifdef TTY_SOFT_SAK
 	tty_hangup(tty);
 #else
-	struct tty_struct *tty = arg;
 	struct task_struct *g, *p;
 	int session;
 	int		i;
 	struct file	*filp;
-	struct tty_ldisc *disc;
 	struct fdtable *fdt;
 	
 	if (!tty)
 		return;
 	session = tty->session;
 	
-	/* We don't want an ldisc switch during this */
-	disc = tty_ldisc_ref(tty);
-	if (disc && disc->flush_buffer)
-		disc->flush_buffer(tty);
-	tty_ldisc_deref(disc);
+	tty_ldisc_flush(tty);
 
 	if (tty->driver->flush_buffer)
 		tty->driver->flush_buffer(tty);
@@ -3341,7 +3371,7 @@ static void __do_SAK(void *arg)
 	/* Kill the entire session */
 	do_each_task_pid(session, PIDTYPE_SID, p) {
 		printk(KERN_NOTICE "SAK: killed process %d"
-			" (%s): p->signal->session==tty->session\n",
+			" (%s): process_session(p)==tty->session\n",
 			p->pid, p->comm);
 		send_sig(SIGKILL, p, 1);
 	} while_each_task_pid(session, PIDTYPE_SID, p);
@@ -3351,7 +3381,7 @@ static void __do_SAK(void *arg)
 	do_each_thread(g, p) {
 		if (p->signal->tty == tty) {
 			printk(KERN_NOTICE "SAK: killed process %d"
-			    " (%s): p->signal->session==tty->session\n",
+			    " (%s): process_session(p)==tty->session\n",
 			    p->pid, p->comm);
 			send_sig(SIGKILL, p, 1);
 			continue;
@@ -3395,7 +3425,7 @@ void do_SAK(struct tty_struct *tty)
 {
 	if (!tty)
 		return;
-	PREPARE_WORK(&tty->SAK_work, __do_SAK, tty);
+	PREPARE_WORK(&tty->SAK_work, __do_SAK);
 	schedule_work(&tty->SAK_work);
 }
 
@@ -3403,7 +3433,7 @@ EXPORT_SYMBOL(do_SAK);
 
 /**
  *	flush_to_ldisc
- *	@private_: tty structure passed from work queue.
+ *	@work: tty structure passed from work queue.
  *
  *	This routine is called out of the software interrupt to flush data
  *	from the buffer chain to the line discipline.
@@ -3413,9 +3443,10 @@ EXPORT_SYMBOL(do_SAK);
  *	receive_buf method is single threaded for each tty instance.
  */
  
-static void flush_to_ldisc(void *private_)
+static void flush_to_ldisc(struct work_struct *work)
 {
-	struct tty_struct *tty = (struct tty_struct *) private_;
+	struct tty_struct *tty =
+		container_of(work, struct tty_struct, buf.work.work);
 	unsigned long 	flags;
 	struct tty_ldisc *disc;
 	struct tty_buffer *tbuf, *head;
@@ -3460,84 +3491,6 @@ static void flush_to_ldisc(void *private_)
 	tty_ldisc_deref(disc);
 }
 
-/*
- * Routine which returns the baud rate of the tty
- *
- * Note that the baud_table needs to be kept in sync with the
- * include/asm/termbits.h file.
- */
-static int baud_table[] = {
-	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
-	9600, 19200, 38400, 57600, 115200, 230400, 460800,
-#ifdef __sparc__
-	76800, 153600, 307200, 614400, 921600
-#else
-	500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
-	2500000, 3000000, 3500000, 4000000
-#endif
-};
-
-static int n_baud_table = ARRAY_SIZE(baud_table);
-
-/**
- *	tty_termios_baud_rate
- *	@termios: termios structure
- *
- *	Convert termios baud rate data into a speed. This should be called
- *	with the termios lock held if this termios is a terminal termios
- *	structure. May change the termios data.
- *
- *	Locking: none
- */
- 
-int tty_termios_baud_rate(struct termios *termios)
-{
-	unsigned int cbaud;
-	
-	cbaud = termios->c_cflag & CBAUD;
-
-	if (cbaud & CBAUDEX) {
-		cbaud &= ~CBAUDEX;
-
-		if (cbaud < 1 || cbaud + 15 > n_baud_table)
-			termios->c_cflag &= ~CBAUDEX;
-		else
-			cbaud += 15;
-	}
-	return baud_table[cbaud];
-}
-
-EXPORT_SYMBOL(tty_termios_baud_rate);
-
-/**
- *	tty_get_baud_rate	-	get tty bit rates
- *	@tty: tty to query
- *
- *	Returns the baud rate as an integer for this terminal. The
- *	termios lock must be held by the caller and the terminal bit
- *	flags may be updated.
- *
- *	Locking: none
- */
- 
-int tty_get_baud_rate(struct tty_struct *tty)
-{
-	int baud = tty_termios_baud_rate(tty->termios);
-
-	if (baud == 38400 && tty->alt_speed) {
-		if (!tty->warned) {
-			printk(KERN_WARNING "Use of setserial/setrocket to "
-					    "set SPD_* flags is deprecated\n");
-			tty->warned = 1;
-		}
-		baud = tty->alt_speed;
-	}
-	
-	return baud;
-}
-
-EXPORT_SYMBOL(tty_get_baud_rate);
-
 /**
  *	tty_flip_buffer_push	-	terminal
  *	@tty: tty to push
@@ -3560,7 +3513,7 @@ void tty_flip_buffer_push(struct tty_struct *tty)
 	spin_unlock_irqrestore(&tty->buf.lock, flags);
 
 	if (tty->low_latency)
-		flush_to_ldisc((void *) tty);
+		flush_to_ldisc(&tty->buf.work.work);
 	else
 		schedule_delayed_work(&tty->buf.work, 1);
 }
@@ -3587,17 +3540,17 @@ static void initialize_tty_struct(struct tty_struct *tty)
 	tty->overrun_time = jiffies;
 	tty->buf.head = tty->buf.tail = NULL;
 	tty_buffer_init(tty);
-	INIT_WORK(&tty->buf.work, flush_to_ldisc, tty);
+	INIT_DELAYED_WORK(&tty->buf.work, flush_to_ldisc);
 	init_MUTEX(&tty->buf.pty_sem);
 	mutex_init(&tty->termios_mutex);
 	init_waitqueue_head(&tty->write_wait);
 	init_waitqueue_head(&tty->read_wait);
-	INIT_WORK(&tty->hangup_work, do_tty_hangup, tty);
+	INIT_WORK(&tty->hangup_work, do_tty_hangup);
 	mutex_init(&tty->atomic_read_lock);
 	mutex_init(&tty->atomic_write_lock);
 	spin_lock_init(&tty->read_lock);
 	INIT_LIST_HEAD(&tty->tty_files);
-	INIT_WORK(&tty->SAK_work, NULL, NULL);
+	INIT_WORK(&tty->SAK_work, NULL);
 }
 
 /*
@@ -3619,7 +3572,8 @@ static struct class *tty_class;
  *		This field is optional, if there is no known struct device
  *		for this tty device it can be set to NULL safely.
  *
- *	Returns a pointer to the class device (or ERR_PTR(-EFOO) on error).
+ *	Returns a pointer to the struct device for this tty device
+ *	(or ERR_PTR(-EFOO) on error).
  *
  *	This call is required to be made to register an individual tty device
  *	if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set.  If
@@ -3629,8 +3583,8 @@ static struct class *tty_class;
  *	Locking: ??
  */
 
-struct class_device *tty_register_device(struct tty_driver *driver,
-					 unsigned index, struct device *device)
+struct device *tty_register_device(struct tty_driver *driver, unsigned index,
+				   struct device *device)
 {
 	char name[64];
 	dev_t dev = MKDEV(driver->major, driver->minor_start) + index;
@@ -3646,7 +3600,7 @@ struct class_device *tty_register_device(struct tty_driver *driver,
 	else
 		tty_line_name(driver, index, name);
 
-	return class_device_create(tty_class, NULL, dev, device, "%s", name);
+	return device_create(tty_class, device, dev, name);
 }
 
 /**
@@ -3662,7 +3616,7 @@ struct class_device *tty_register_device(struct tty_driver *driver,
 
 void tty_unregister_device(struct tty_driver *driver, unsigned index)
 {
-	class_device_destroy(tty_class, MKDEV(driver->major, driver->minor_start) + index);
+	device_destroy(tty_class, MKDEV(driver->major, driver->minor_start) + index);
 }
 
 EXPORT_SYMBOL(tty_register_device);
@@ -3687,7 +3641,8 @@ void put_tty_driver(struct tty_driver *driver)
 	kfree(driver);
 }
 
-void tty_set_operations(struct tty_driver *driver, struct tty_operations *op)
+void tty_set_operations(struct tty_driver *driver,
+			const struct tty_operations *op)
 {
 	driver->open = op->open;
 	driver->close = op->close;
@@ -3758,8 +3713,8 @@ int tty_register_driver(struct tty_driver *driver)
 
 	if (p) {
 		driver->ttys = (struct tty_struct **)p;
-		driver->termios = (struct termios **)(p + driver->num);
-		driver->termios_locked = (struct termios **)(p + driver->num * 2);
+		driver->termios = (struct ktermios **)(p + driver->num);
+		driver->termios_locked = (struct ktermios **)(p + driver->num * 2);
 	} else {
 		driver->ttys = NULL;
 		driver->termios = NULL;
@@ -3798,7 +3753,7 @@ EXPORT_SYMBOL(tty_register_driver);
 int tty_unregister_driver(struct tty_driver *driver)
 {
 	int i;
-	struct termios *tp;
+	struct ktermios *tp;
 	void *p;
 
 	if (driver->refcount)
@@ -3836,9 +3791,56 @@ int tty_unregister_driver(struct tty_driver *driver)
 	cdev_del(&driver->cdev);
 	return 0;
 }
-
 EXPORT_SYMBOL(tty_unregister_driver);
 
+dev_t tty_devnum(struct tty_struct *tty)
+{
+	WARN_ON(!tty);
+	WARN_ON(!tty->magic);
+	WARN_ON(!tty->driver);
+	return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
+}
+EXPORT_SYMBOL(tty_devnum);
+
+void proc_clear_tty(struct task_struct *p)
+{
+	spin_lock_irq(&p->sighand->siglock);
+	p->signal->tty = NULL;
+	spin_unlock_irq(&p->sighand->siglock);
+}
+EXPORT_SYMBOL(proc_clear_tty);
+
+void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
+{
+	if (tty) {
+		tty->session = process_session(tsk);
+		tty->pgrp = process_group(tsk);
+	}
+	tsk->signal->tty = tty;
+	tsk->signal->tty_old_pgrp = 0;
+}
+
+void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
+{
+	spin_lock_irq(&tsk->sighand->siglock);
+	__proc_set_tty(tsk, tty);
+	spin_unlock_irq(&tsk->sighand->siglock);
+}
+
+struct tty_struct *get_current_tty(void)
+{
+	struct tty_struct *tty;
+	WARN_ON_ONCE(!mutex_is_locked(&tty_mutex));
+	tty = current->signal->tty;
+	/*
+	 * session->tty can be changed/cleared from under us, make sure we
+	 * issue the load. The obtained pointer, when not NULL, is valid as
+	 * long as we hold tty_mutex.
+	 */
+	barrier();
+	return tty;
+}
+EXPORT_SYMBOL_GPL(get_current_tty);
 
 /*
  * Initialize the console device. This is called *early*, so
@@ -3901,20 +3903,20 @@ static int __init tty_init(void)
 	if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
 	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
 		panic("Couldn't register /dev/tty driver\n");
-	class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty");
+	device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), "tty");
 
 	cdev_init(&console_cdev, &console_fops);
 	if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
 	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
 		panic("Couldn't register /dev/console driver\n");
-	class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, "console");
+	device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), "console");
 
 #ifdef CONFIG_UNIX98_PTYS
 	cdev_init(&ptmx_cdev, &ptmx_fops);
 	if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
 	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
 		panic("Couldn't register /dev/ptmx driver\n");
-	class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
+	device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), "ptmx");
 #endif
 
 #ifdef CONFIG_VT
@@ -3922,7 +3924,7 @@ static int __init tty_init(void)
 	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
 	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
 		panic("Couldn't register /dev/tty0 driver\n");
-	class_device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
+	device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), "tty0");
 
 	vty_init();
  out_vt: