diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 0e1e9a20a4d67b032f59f910d6adafa5a760978d..01d4ab6b0ef1889582f4d5defb4142138b0141f0 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -774,7 +774,7 @@ static irqreturn_t winch_interrupt(int irq, void *data)
 		line = tty->driver_data;
 		chan_window_size(&line->chan_list, &tty->winsize.ws_row,
 				 &tty->winsize.ws_col);
-		kill_pg(tty->pgrp, SIGWINCH, 1);
+		kill_pgrp(tty->pgrp, SIGWINCH, 1);
 	}
  out:
 	if(winch->fd != -1)
diff --git a/drivers/char/ip2/ip2main.c b/drivers/char/ip2/ip2main.c
index 7c70310a49b5b48a771a86f188f8489521c07123..83c7258d358067c3d72944494b4ff49a891407e4 100644
--- a/drivers/char/ip2/ip2main.c
+++ b/drivers/char/ip2/ip2main.c
@@ -1271,8 +1271,8 @@ static void do_input(struct work_struct *work)
 // code duplicated from n_tty (ldisc)
 static inline void  isig(int sig, struct tty_struct *tty, int flush)
 {
-	if (tty->pgrp > 0)
-		kill_pg(tty->pgrp, sig, 1);
+	if (tty->pgrp)
+		kill_pgrp(tty->pgrp, sig, 1);
 	if (flush || !L_NOFLSH(tty)) {
 		if ( tty->ldisc.flush_buffer )  
 			tty->ldisc.flush_buffer(tty);
diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index c035c2f1f462bb6d8ad5cf4c32bc525090d15166..6ac3ca4c723c2c660c5d084b9c7834035767fbb5 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -579,8 +579,8 @@ static void eraser(unsigned char c, struct tty_struct *tty)
  
 static inline void isig(int sig, struct tty_struct *tty, int flush)
 {
-	if (tty->pgrp > 0)
-		kill_pg(tty->pgrp, sig, 1);
+	if (tty->pgrp)
+		kill_pgrp(tty->pgrp, sig, 1);
 	if (flush || !L_NOFLSH(tty)) {
 		n_tty_flush_buffer(tty);
 		if (tty->driver->flush_buffer)
@@ -1184,13 +1184,13 @@ static int job_control(struct tty_struct *tty, struct file *file)
 	/* don't stop on /dev/console */
 	if (file->f_op->write != redirected_tty_write &&
 	    current->signal->tty == tty) {
-		if (tty->pgrp <= 0)
-			printk("read_chan: tty->pgrp <= 0!\n");
-		else if (process_group(current) != tty->pgrp) {
+		if (!tty->pgrp)
+			printk("read_chan: no tty->pgrp!\n");
+		else if (task_pgrp(current) != tty->pgrp) {
 			if (is_ignored(SIGTTIN) ||
 			    is_current_pgrp_orphaned())
 				return -EIO;
-			kill_pg(process_group(current), SIGTTIN, 1);
+			kill_pgrp(task_pgrp(current), SIGTTIN, 1);
 			return -ERESTARTSYS;
 		}
 	}
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 94070f7bf38963845bcdd783b02ff305cc46d0c9..65672c57470b87282c3f4a73d261564310ca5565 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -155,7 +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 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);
 
 /**
  *	alloc_tty_struct	-	allocate a tty object
@@ -1110,17 +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_current_pgrp_orphaned())
 		return -EIO;
-	(void) kill_pg(process_group(current), SIGTTOU, 1);
+	(void) kill_pgrp(task_pgrp(current), SIGTTOU, 1);
 	return -ERESTARTSYS;
 }
 
@@ -1355,8 +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;
@@ -1366,16 +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
@@ -1460,12 +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);
 }
 
 /**
@@ -1495,48 +1497,54 @@ static void session_clear_tty(pid_t session)
 void disassociate_ctty(int on_exit)
 {
 	struct tty_struct *tty;
-	int tty_pgrp = -1;
+	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 if (on_exit) {
-		pid_t old_pgrp;
+		struct pid *old_pgrp;
 		spin_lock_irq(&current->sighand->siglock);
 		old_pgrp = current->signal->tty_old_pgrp;
-		current->signal->tty_old_pgrp = 0;
+		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);
+	tty_pgrp = current->signal->tty_old_pgrp;
 	current->signal->tty_old_pgrp = 0;
 	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]"
@@ -1547,7 +1555,7 @@ void disassociate_ctty(int on_exit)
 
 	/* Now clear signal->tty under the lock */
 	read_lock(&tasklist_lock);
-	session_clear_tty(process_session(current));
+	session_clear_tty(task_session(current));
 	read_unlock(&tasklist_lock);
 	unlock_kernel();
 }
@@ -2484,6 +2492,7 @@ 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);
 	
@@ -2577,15 +2586,17 @@ static int tty_open(struct inode * inode, struct file * filp)
 		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;
 }
 
@@ -2724,9 +2735,18 @@ 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 {
@@ -2828,10 +2848,10 @@ 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:
@@ -2916,8 +2936,7 @@ 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);
@@ -2930,7 +2949,7 @@ 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!
@@ -2973,7 +2992,7 @@ 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);
 }
 
 /**
@@ -3000,7 +3019,7 @@ 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 != process_session(current)))
+	    (real_tty->session != task_session(current)))
 		return -ENOTTY;
 	if (get_user(pgrp_nr, p))
 		return -EFAULT;
@@ -3015,7 +3034,8 @@ static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
 	if (session_of_pgrp(pgrp) != task_session(current))
 		goto out_unlock;
 	retval = 0;
-	real_tty->pgrp = pgrp_nr;
+	put_pid(real_tty->pgrp);
+	real_tty->pgrp = get_pid(pgrp);
 out_unlock:
 	rcu_read_unlock();
 	return retval;
@@ -3041,9 +3061,9 @@ 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);
 }
 
 /**
@@ -3343,7 +3363,7 @@ 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;
@@ -3359,12 +3379,12 @@ 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.
 	 */
@@ -3533,7 +3553,8 @@ 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);
@@ -3804,21 +3825,28 @@ void proc_clear_tty(struct task_struct *p)
 }
 EXPORT_SYMBOL(proc_clear_tty);
 
-static 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)
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index d6694163b6f1db001c8392859194caec1653672c..94ce3e7fc9e419be797bcd46647586d30a4457b5 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -866,8 +866,8 @@ int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int lines)
 		ws.ws_col = vc->vc_cols;
 		ws.ws_ypixel = vc->vc_scan_lines;
 		if ((ws.ws_row != cws->ws_row || ws.ws_col != cws->ws_col) &&
-		    vc->vc_tty->pgrp > 0)
-			kill_pg(vc->vc_tty->pgrp, SIGWINCH, 1);
+		    vc->vc_tty->pgrp)
+			kill_pgrp(vc->vc_tty->pgrp, SIGWINCH, 1);
 		*cws = ws;
 	}
 
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 70e4fab117b154ec0379aea1f924e5f021195e7e..07c9cdbcdcac6f6a2be5fa40f97a340b2f5980a4 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -351,7 +351,7 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole)
 		struct signal_struct *sig = task->signal;
 
 		if (sig->tty) {
-			tty_pgrp = sig->tty->pgrp;
+			tty_pgrp = pid_nr(sig->tty->pgrp);
 			tty_nr = new_encode_dev(tty_devnum(sig->tty));
 		}
 
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 6383d2d83bb0c5b12e233c5fbfe53e6e47c49578..a2d95ff50e9bd71eb741d5ef9a293574245ab244 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -66,7 +66,7 @@
 	.cpu_timers	= INIT_CPU_TIMERS(sig.cpu_timers),		\
 	.rlim		= INIT_RLIMITS,					\
 	.pgrp		= 1,						\
-	.tty_old_pgrp   = 0,						\
+	.tty_old_pgrp   = NULL,						\
 	{ .__session      = 1},						\
 }
 
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 76c8e2dc48dd3833969d2da24b9c7dbdd6bcc306..39d40c51853100d22a90d0dbbd2edfb5e3f205b9 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -436,7 +436,7 @@ struct signal_struct {
 
 	/* job control IDs */
 	pid_t pgrp;
-	pid_t tty_old_pgrp;
+	struct pid *tty_old_pgrp;
 
 	union {
 		pid_t session __deprecated;
diff --git a/include/linux/tty.h b/include/linux/tty.h
index d0e03c4a71b1c5ba95859747d203c7d8986bd474..dee72b9a20fb320e6809002f3d186e4d0103e611 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -197,8 +197,8 @@ struct tty_struct {
 	struct mutex termios_mutex;
 	struct ktermios *termios, *termios_locked;
 	char name[64];
-	int pgrp;
-	int session;
+	struct pid *pgrp;
+	struct pid *session;
 	unsigned long flags;
 	int count;
 	struct winsize winsize;
diff --git a/kernel/fork.c b/kernel/fork.c
index 80284eb488ced61808dedf0b999af2f55c494d28..0b6293d94d96b412bfb8f33af4903728cf418a7b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -869,7 +869,7 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts
 	sig->it_prof_incr = cputime_zero;
 
 	sig->leader = 0;	/* session leadership doesn't inherit */
-	sig->tty_old_pgrp = 0;
+	sig->tty_old_pgrp = NULL;
 
 	sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero;
 	sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0;
diff --git a/kernel/sys.c b/kernel/sys.c
index e1024383314de0428e4739e0f9c782330ecd63d5..efcf76e0dadababe9c7d2188628cb47a0ad757b6 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1510,7 +1510,6 @@ asmlinkage long sys_setsid(void)
 
 	spin_lock(&group_leader->sighand->siglock);
 	group_leader->signal->tty = NULL;
-	group_leader->signal->tty_old_pgrp = 0;
 	spin_unlock(&group_leader->sighand->siglock);
 
 	err = process_group(group_leader);