X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=drivers%2Fchar%2Ftty_io.c;h=e453268566805238288ba64f96e1c5da0f8a1ba3;hb=9333907084da2b05db787dba3e714d0be7c84f36;hp=558ca927e32b1ebd4d9a7ea0c5b5b41b028b696b;hpb=c827ba4cb49a30ce581201fd0ba2be77cde412c7;p=cascardo%2Flinux.git

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 558ca927e32b..e45326856680 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -155,6 +155,8 @@ 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);
 
 /**
  *	alloc_tty_struct	-	allocate a tty object
@@ -1109,17 +1111,17 @@ int tty_check_change(struct tty_struct * tty)
 {
 	if (current->signal->tty != tty)
 		return 0;
-	if (tty->pgrp <= 0) {
-		printk(KERN_WARNING "tty_check_change: tty->pgrp <= 0!\n");
+	if (!tty->pgrp) {
+		printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n");
 		return 0;
 	}
-	if (process_group(current) == tty->pgrp)
+	if (task_pgrp(current) == tty->pgrp)
 		return 0;
 	if (is_ignored(SIGTTOU))
 		return 0;
-	if (is_orphaned_pgrp(process_group(current)))
+	if (is_current_pgrp_orphaned())
 		return -EIO;
-	(void) kill_pg(process_group(current), SIGTTOU, 1);
+	(void) kill_pgrp(task_pgrp(current), SIGTTOU, 1);
 	return -ERESTARTSYS;
 }
 
@@ -1354,8 +1356,8 @@ static void do_tty_hangup(struct work_struct *work)
 	  tty_release is called */
 	
 	read_lock(&tasklist_lock);
-	if (tty->session > 0) {
-		do_each_task_pid(tty->session, PIDTYPE_SID, p) {
+	if (tty->session) {
+		do_each_pid_task(tty->session, PIDTYPE_SID, p) {
 			spin_lock_irq(&p->sighand->siglock);
 			if (p->signal->tty == tty)
 				p->signal->tty = NULL;
@@ -1365,16 +1367,17 @@ static void do_tty_hangup(struct work_struct *work)
 			}
 			__group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p);
 			__group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p);
-			if (tty->pgrp > 0)
-				p->signal->tty_old_pgrp = tty->pgrp;
+			put_pid(p->signal->tty_old_pgrp);  /* A noop */
+			if (tty->pgrp)
+				p->signal->tty_old_pgrp = get_pid(tty->pgrp);
 			spin_unlock_irq(&p->sighand->siglock);
-		} while_each_task_pid(tty->session, PIDTYPE_SID, p);
+		} while_each_pid_task(tty->session, PIDTYPE_SID, p);
 	}
 	read_unlock(&tasklist_lock);
 
 	tty->flags = 0;
-	tty->session = 0;
-	tty->pgrp = -1;
+	tty->session = NULL;
+	tty->pgrp = NULL;
 	tty->ctrl_status = 0;
 	/*
 	 *	If one of the devices matches a console pointer, we
@@ -1459,12 +1462,12 @@ int tty_hung_up_p(struct file * filp)
 
 EXPORT_SYMBOL(tty_hung_up_p);
 
-static void session_clear_tty(pid_t session)
+static void session_clear_tty(struct pid *session)
 {
 	struct task_struct *p;
-	do_each_task_pid(session, PIDTYPE_SID, p) {
+	do_each_pid_task(session, PIDTYPE_SID, p) {
 		proc_clear_tty(p);
-	} while_each_task_pid(session, PIDTYPE_SID, p);
+	} while_each_pid_task(session, PIDTYPE_SID, p);
 }
 
 /**
@@ -1494,46 +1497,54 @@ static void session_clear_tty(pid_t session)
 void disassociate_ctty(int on_exit)
 {
 	struct tty_struct *tty;
-	int tty_pgrp = -1;
-	int session;
+	struct pid *tty_pgrp = NULL;
 
 	lock_kernel();
 
 	mutex_lock(&tty_mutex);
 	tty = get_current_tty();
 	if (tty) {
-		tty_pgrp = tty->pgrp;
+		tty_pgrp = get_pid(tty->pgrp);
 		mutex_unlock(&tty_mutex);
 		/* XXX: here we race, there is nothing protecting tty */
 		if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY)
 			tty_vhangup(tty);
-	} else {
-		pid_t old_pgrp = current->signal->tty_old_pgrp;
+	} else if (on_exit) {
+		struct pid *old_pgrp;
+		spin_lock_irq(&current->sighand->siglock);
+		old_pgrp = current->signal->tty_old_pgrp;
+		current->signal->tty_old_pgrp = NULL;
+		spin_unlock_irq(&current->sighand->siglock);
 		if (old_pgrp) {
-			kill_pg(old_pgrp, SIGHUP, on_exit);
-			kill_pg(old_pgrp, SIGCONT, on_exit);
+			kill_pgrp(old_pgrp, SIGHUP, on_exit);
+			kill_pgrp(old_pgrp, SIGCONT, on_exit);
+			put_pid(old_pgrp);
 		}
 		mutex_unlock(&tty_mutex);
 		unlock_kernel();	
 		return;
 	}
-	if (tty_pgrp > 0) {
-		kill_pg(tty_pgrp, SIGHUP, on_exit);
+	if (tty_pgrp) {
+		kill_pgrp(tty_pgrp, SIGHUP, on_exit);
 		if (!on_exit)
-			kill_pg(tty_pgrp, SIGCONT, on_exit);
+			kill_pgrp(tty_pgrp, SIGCONT, on_exit);
+		put_pid(tty_pgrp);
 	}
 
 	spin_lock_irq(&current->sighand->siglock);
-	current->signal->tty_old_pgrp = 0;
-	session = process_session(current);
+	tty_pgrp = 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 */
 	tty = get_current_tty();
 	if (tty) {
-		tty->session = 0;
-		tty->pgrp = 0;
+		put_pid(tty->session);
+		put_pid(tty->pgrp);
+		tty->session = NULL;
+		tty->pgrp = NULL;
 	} else {
 #ifdef TTY_DEBUG_HANGUP
 		printk(KERN_DEBUG "error attempted to write to tty [0x%p]"
@@ -1544,7 +1555,7 @@ void disassociate_ctty(int on_exit)
 
 	/* Now clear signal->tty under the lock */
 	read_lock(&tasklist_lock);
-	session_clear_tty(session);
+	session_clear_tty(task_session(current));
 	read_unlock(&tasklist_lock);
 	unlock_kernel();
 }
@@ -1890,6 +1901,20 @@ 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 {
@@ -2481,6 +2506,7 @@ 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);
 	
@@ -2574,15 +2600,17 @@ 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 == 0)
-		__proc_set_tty(current, tty);
+	    tty->session == NULL)
+		old_pgrp = __proc_set_tty(current, tty);
 	spin_unlock_irq(&current->sighand->siglock);
 	mutex_unlock(&tty_mutex);
+	put_pid(old_pgrp);
 	return 0;
 }
 
@@ -2721,9 +2749,18 @@ static int tty_fasync(int fd, struct file * filp, int on)
 		return retval;
 
 	if (on) {
+		enum pid_type type;
+		struct pid *pid;
 		if (!waitqueue_active(&tty->read_wait))
 			tty->minimum_to_wake = 1;
-		retval = f_setown(filp, (-tty->pgrp) ? : current->pid, 0);
+		if (tty->pgrp) {
+			pid = tty->pgrp;
+			type = PIDTYPE_PGID;
+		} else {
+			pid = task_pid(current);
+			type = PIDTYPE_PID;
+		}
+		retval = __f_setown(filp, pid, type, 0);
 		if (retval)
 			return retval;
 	} else {
@@ -2825,10 +2862,10 @@ static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty,
 		}
 	}
 #endif
-	if (tty->pgrp > 0)
-		kill_pg(tty->pgrp, SIGWINCH, 1);
-	if ((real_tty->pgrp != tty->pgrp) && (real_tty->pgrp > 0))
-		kill_pg(real_tty->pgrp, SIGWINCH, 1);
+	if (tty->pgrp)
+		kill_pgrp(tty->pgrp, SIGWINCH, 1);
+	if ((real_tty->pgrp != tty->pgrp) && real_tty->pgrp)
+		kill_pgrp(real_tty->pgrp, SIGWINCH, 1);
 	tty->winsize = tmp_ws;
 	real_tty->winsize = tmp_ws;
 done:
@@ -2913,8 +2950,7 @@ static int fionbio(struct file *file, int __user *p)
 static int tiocsctty(struct tty_struct *tty, int arg)
 {
 	int ret = 0;
-	if (current->signal->leader &&
-			(process_session(current) == tty->session))
+	if (current->signal->leader && (task_session(current) == tty->session))
 		return ret;
 
 	mutex_lock(&tty_mutex);
@@ -2927,7 +2963,7 @@ static int tiocsctty(struct tty_struct *tty, int arg)
 		goto unlock;
 	}
 
-	if (tty->session > 0) {
+	if (tty->session) {
 		/*
 		 * This tty is already the controlling
 		 * tty for another session group!
@@ -2970,7 +3006,7 @@ static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
 	 */
 	if (tty == real_tty && current->signal->tty != real_tty)
 		return -ENOTTY;
-	return put_user(real_tty->pgrp, p);
+	return put_user(pid_nr(real_tty->pgrp), p);
 }
 
 /**
@@ -2987,7 +3023,8 @@ static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
 
 static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
 {
-	pid_t pgrp;
+	struct pid *pgrp;
+	pid_t pgrp_nr;
 	int retval = tty_check_change(real_tty);
 
 	if (retval == -EIO)
@@ -2996,16 +3033,26 @@ 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 != process_session(current)))
+	    (real_tty->session != task_session(current)))
 		return -ENOTTY;
-	if (get_user(pgrp, p))
+	if (get_user(pgrp_nr, p))
 		return -EFAULT;
-	if (pgrp < 0)
+	if (pgrp_nr < 0)
 		return -EINVAL;
-	if (session_of_pgrp(pgrp) != process_session(current))
-		return -EPERM;
-	real_tty->pgrp = pgrp;
-	return 0;
+	rcu_read_lock();
+	pgrp = find_pid(pgrp_nr);
+	retval = -ESRCH;
+	if (!pgrp)
+		goto out_unlock;
+	retval = -EPERM;
+	if (session_of_pgrp(pgrp) != task_session(current))
+		goto out_unlock;
+	retval = 0;
+	put_pid(real_tty->pgrp);
+	real_tty->pgrp = get_pid(pgrp);
+out_unlock:
+	rcu_read_unlock();
+	return retval;
 }
 
 /**
@@ -3028,9 +3075,9 @@ static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t _
 	*/
 	if (tty == real_tty && current->signal->tty != real_tty)
 		return -ENOTTY;
-	if (real_tty->session <= 0)
+	if (!real_tty->session)
 		return -ENOTTY;
-	return put_user(real_tty->session, p);
+	return put_user(pid_nr(real_tty->session), p);
 }
 
 /**
@@ -3330,7 +3377,7 @@ void __do_SAK(struct tty_struct *tty)
 	tty_hangup(tty);
 #else
 	struct task_struct *g, *p;
-	int session;
+	struct pid *session;
 	int		i;
 	struct file	*filp;
 	struct fdtable *fdt;
@@ -3346,12 +3393,12 @@ void __do_SAK(struct tty_struct *tty)
 	
 	read_lock(&tasklist_lock);
 	/* Kill the entire session */
-	do_each_task_pid(session, PIDTYPE_SID, p) {
+	do_each_pid_task(session, PIDTYPE_SID, p) {
 		printk(KERN_NOTICE "SAK: killed process %d"
 			" (%s): process_session(p)==tty->session\n",
 			p->pid, p->comm);
 		send_sig(SIGKILL, p, 1);
-	} while_each_task_pid(session, PIDTYPE_SID, p);
+	} while_each_pid_task(session, PIDTYPE_SID, p);
 	/* Now kill any processes that happen to have the
 	 * tty open.
 	 */
@@ -3409,7 +3456,6 @@ void do_SAK(struct tty_struct *tty)
 {
 	if (!tty)
 		return;
-	PREPARE_WORK(&tty->SAK_work, do_SAK_work);
 	schedule_work(&tty->SAK_work);
 }
 
@@ -3520,7 +3566,8 @@ static void initialize_tty_struct(struct tty_struct *tty)
 	memset(tty, 0, sizeof(struct tty_struct));
 	tty->magic = TTY_MAGIC;
 	tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
-	tty->pgrp = -1;
+	tty->session = NULL;
+	tty->pgrp = NULL;
 	tty->overrun_time = jiffies;
 	tty->buf.head = tty->buf.tail = NULL;
 	tty_buffer_init(tty);
@@ -3534,7 +3581,7 @@ static void initialize_tty_struct(struct tty_struct *tty)
 	mutex_init(&tty->atomic_write_lock);
 	spin_lock_init(&tty->read_lock);
 	INIT_LIST_HEAD(&tty->tty_files);
-	INIT_WORK(&tty->SAK_work, NULL);
+	INIT_WORK(&tty->SAK_work, do_SAK_work);
 }
 
 /*
@@ -3680,15 +3727,14 @@ int tty_register_driver(struct tty_driver *driver)
 
 	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);
@@ -3791,21 +3837,28 @@ void proc_clear_tty(struct task_struct *p)
 }
 EXPORT_SYMBOL(proc_clear_tty);
 
-void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
+static struct pid *__proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
 {
+	struct pid *old_pgrp;
 	if (tty) {
-		tty->session = process_session(tsk);
-		tty->pgrp = process_group(tsk);
+		tty->session = get_pid(task_session(tsk));
+		tty->pgrp = get_pid(task_pgrp(tsk));
 	}
+	old_pgrp = tsk->signal->tty_old_pgrp;
 	tsk->signal->tty = tty;
-	tsk->signal->tty_old_pgrp = 0;
+	tsk->signal->tty_old_pgrp = NULL;
+	return old_pgrp;
 }
 
 void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
 {
+	struct pid *old_pgrp;
+
 	spin_lock_irq(&tsk->sighand->siglock);
-	__proc_set_tty(tsk, tty);
+	old_pgrp = __proc_set_tty(tsk, tty);
 	spin_unlock_irq(&tsk->sighand->siglock);
+
+	put_pid(old_pgrp);
 }
 
 struct tty_struct *get_current_tty(void)