Merge branch 'gfar' of master.kernel.org:/pub/scm/linux/kernel/git/galak/powerpc into upstream

1 files changed, 146 insertions, 100 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 47a6eacb10bc..65672c57470b 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -154,7 +154,9 @@ static int tty_release(struct inode *, struct file *);
 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_mem(struct tty_struct *tty, int idx);
+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);
+        tty_pgrp = current->signal->tty_old_pgrp;
         current->signal->tty_old_pgrp = 0;
-        session = process_session(current);
         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();
 }
@@ -1612,7 +1623,6 @@ void start_tty(struct tty_struct *tty)
 
         /* If we have a running line discipline it may need kicking */
         tty_wakeup(tty);
-        wake_up_interruptible(&tty->write_wait);
 }
 
 EXPORT_SYMBOL(start_tty);
@@ -2003,7 +2013,7 @@ static int init_dev(struct tty_driver *driver, int idx,
 
         /* 
          * All structures have been allocated, so now we install them.
-         * Failures after this point use release_mem to clean up, so 
+         * Failures after this point use release_tty to clean up, so
          * there's no need to null out the local pointers.
          */
         if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
@@ -2024,8 +2034,8 @@ static int init_dev(struct tty_driver *driver, int idx,
 
         /* 
          * Structures all installed ... call the ldisc open routines.
-         * If we fail here just call release_mem to clean up.  No need
-         * to decrement the use counts, as release_mem doesn't care.
+         * If we fail here just call release_tty to clean up.  No need
+         * to decrement the use counts, as release_tty doesn't care.
          */
 
         if (tty->ldisc.open) {
@@ -2095,17 +2105,17 @@ fail_no_mem:
         retval = -ENOMEM;
         goto end_init;
 
-        /* call the tty release_mem routine to clean out this slot */
+        /* call the tty release_tty routine to clean out this slot */
 release_mem_out:
         if (printk_ratelimit())
                 printk(KERN_INFO "init_dev: ldisc open failed, "
                                  "clearing slot %d\n", idx);
-        release_mem(tty, idx);
+        release_tty(tty, idx);
         goto end_init;
 }
 
 /**
- *      release_mem             -       release tty structure memory
+ *      release_one_tty         -       release tty structure memory
  *
  *      Releases memory associated with a tty structure, and clears out the
  *      driver table slots. This function is called when a device is no longer
@@ -2117,37 +2127,14 @@ release_mem_out:
  *      of ttys that the driver keeps.
  *              FIXME: should we require tty_mutex is held here ??
  */
-
-static void release_mem(struct tty_struct *tty, int idx)
+static void release_one_tty(struct tty_struct *tty, int idx)
 {
-        struct tty_struct *o_tty;
-        struct ktermios *tp;
         int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM;
-
-        if ((o_tty = tty->link) != NULL) {
-                if (!devpts)
-                        o_tty->driver->ttys[idx] = NULL;
-                if (o_tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
-                        tp = o_tty->termios;
-                        if (!devpts)
-                                o_tty->driver->termios[idx] = NULL;
-                        kfree(tp);
-
-                        tp = o_tty->termios_locked;
-                        if (!devpts)
-                                o_tty->driver->termios_locked[idx] = NULL;
-                        kfree(tp);
-                }
-                o_tty->magic = 0;
-                o_tty->driver->refcount--;
-                file_list_lock();
-                list_del_init(&o_tty->tty_files);
-                file_list_unlock();
-                free_tty_struct(o_tty);
-        }
+        struct ktermios *tp;
 
         if (!devpts)
                 tty->driver->ttys[idx] = NULL;
+
         if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
                 tp = tty->termios;
                 if (!devpts)
@@ -2160,15 +2147,39 @@ static void release_mem(struct tty_struct *tty, int idx)
                 kfree(tp);
         }
 
+
         tty->magic = 0;
         tty->driver->refcount--;
+
         file_list_lock();
         list_del_init(&tty->tty_files);
         file_list_unlock();
-        module_put(tty->driver->owner);
+
         free_tty_struct(tty);
 }
 
+/**
+ *      release_tty             -       release tty structure memory
+ *
+ *      Release both @tty and a possible linked partner (think pty pair),
+ *      and decrement the refcount of the backing module.
+ *
+ *      Locking:
+ *              tty_mutex - sometimes only
+ *              takes the file list lock internally when working on the list
+ *      of ttys that the driver keeps.
+ *              FIXME: should we require tty_mutex is held here ??
+ */
+static void release_tty(struct tty_struct *tty, int idx)
+{
+        struct tty_driver *driver = tty->driver;
+
+        if (tty->link)
+                release_one_tty(tty->link, idx);
+        release_one_tty(tty, idx);
+        module_put(driver->owner);
+}
+
 /*
  * Even releasing the tty structures is a tricky business.. We have
  * to be very careful that the structures are all released at the
@@ -2436,10 +2447,10 @@ static void release_dev(struct file * filp)
                 tty_set_termios_ldisc(o_tty,N_TTY); 
         }
         /*
-         * The release_mem function takes care of the details of clearing
+         * The release_tty function takes care of the details of clearing
          * the slots and preserving the termios structure.
          */
-        release_mem(tty, idx);
+        release_tty(tty, idx);
 
 #ifdef CONFIG_UNIX98_PTYS
         /* Make this pty number available for reallocation */
@@ -2481,6 +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);
         
@@ -2574,15 +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;
 }
 
@@ -2721,9 +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 {
@@ -2825,10 +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:
@@ -2913,8 +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);
@@ -2927,7 +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!
@@ -2970,7 +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);
 }
 
 /**
@@ -2987,7 +3009,8 @@ 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 +3019,26 @@ 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 +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);
 }
 
 /**
@@ -3324,15 +3357,13 @@ 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(struct work_struct *work)
+void __do_SAK(struct tty_struct *tty)
 {
-        struct tty_struct *tty =
-                container_of(work, struct tty_struct, SAK_work);
 #ifdef TTY_SOFT_SAK
         tty_hangup(tty);
 #else
         struct task_struct *g, *p;
-        int session;
+        struct pid *session;
         int             i;
         struct file     *filp;
         struct fdtable *fdt;
@@ -3348,12 +3379,12 @@ static void __do_SAK(struct work_struct *work)
         
         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.
          */
@@ -3394,6 +3425,13 @@ static void __do_SAK(struct work_struct *work)
 #endif
 }
 
+static void do_SAK_work(struct work_struct *work)
+{
+        struct tty_struct *tty =
+                container_of(work, struct tty_struct, SAK_work);
+        __do_SAK(tty);
+}
+
 /*
  * The tq handling here is a little racy - tty->SAK_work may already be queued.
  * Fortunately we don't need to worry, because if ->SAK_work is already queued,
@@ -3404,7 +3442,7 @@ void do_SAK(struct tty_struct *tty)
 {
         if (!tty)
                 return;
-        PREPARE_WORK(&tty->SAK_work, __do_SAK);
+        PREPARE_WORK(&tty->SAK_work, do_SAK_work);
         schedule_work(&tty->SAK_work);
 }
 
@@ -3515,7 +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);
@@ -3786,21 +3825,28 @@ 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)