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authorKumar Gala <galak@kernel.crashing.org>2007-02-12 23:57:21 -0600
committerKumar Gala <galak@kernel.crashing.org>2007-02-12 23:57:21 -0600
commit54c66f6d781e03dc0b23956234963c4911e6d1c0 (patch)
tree40619a66ae6d8703a57bf681d087ffeabbffd346 /drivers/char/tty_io.c
parent8ce0a7df6e6117d8814e976d4b7ce6a6b2c9cf93 (diff)
parent17e0e27020d028a790d97699aff85a43af5be472 (diff)
Merge branch 'master' into 85xx
Diffstat (limited to 'drivers/char/tty_io.c')
-rw-r--r--drivers/char/tty_io.c246
1 files changed, 146 insertions, 100 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 47a6eacb10b..65672c57470 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)