11 files changed, 96 insertions, 69 deletions

diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 0e1e9a20a4d6..01d4ab6b0ef1 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 7c70310a49b5..83c7258d3580 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 c035c2f1f462..6ac3ca4c723c 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 94070f7bf389..65672c57470b 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 @@ 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;
 }
 
@@ -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 d6694163b6f1..94ce3e7fc9e4 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 70e4fab117b1..07c9cdbcdcac 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 6383d2d83bb0..a2d95ff50e9b 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 76c8e2dc48dd..39d40c518531 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 d0e03c4a71b1..dee72b9a20fb 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 80284eb488ce..0b6293d94d96 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 e1024383314d..efcf76e0dada 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);