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path: root/drivers/tty/tty_io.c
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Diffstat (limited to 'drivers/tty/tty_io.c')
-rw-r--r--drivers/tty/tty_io.c440
1 files changed, 223 insertions, 217 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 0508a1d8e4cd..4f35b43e2475 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -153,8 +153,6 @@ static long tty_compat_ioctl(struct file *file, unsigned int cmd,
static int __tty_fasync(int fd, struct file *filp, int on);
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 void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
/**
* free_tty_struct - free a disused tty
@@ -169,8 +167,7 @@ void free_tty_struct(struct tty_struct *tty)
{
if (!tty)
return;
- if (tty->dev)
- put_device(tty->dev);
+ put_device(tty->dev);
kfree(tty->write_buf);
tty->magic = 0xDEADDEAD;
kfree(tty);
@@ -277,6 +274,7 @@ int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
return 0;
}
+/* Caller must hold tty_lock */
static int check_tty_count(struct tty_struct *tty, const char *routine)
{
#ifdef CHECK_TTY_COUNT
@@ -492,6 +490,78 @@ static const struct file_operations hung_up_tty_fops = {
static DEFINE_SPINLOCK(redirect_lock);
static struct file *redirect;
+
+void proc_clear_tty(struct task_struct *p)
+{
+ unsigned long flags;
+ struct tty_struct *tty;
+ spin_lock_irqsave(&p->sighand->siglock, flags);
+ tty = p->signal->tty;
+ p->signal->tty = NULL;
+ spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ tty_kref_put(tty);
+}
+
+/**
+ * proc_set_tty - set the controlling terminal
+ *
+ * Only callable by the session leader and only if it does not already have
+ * a controlling terminal.
+ *
+ * Caller must hold: tty_lock()
+ * a readlock on tasklist_lock
+ * sighand lock
+ */
+static void __proc_set_tty(struct tty_struct *tty)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ /*
+ * The session and fg pgrp references will be non-NULL if
+ * tiocsctty() is stealing the controlling tty
+ */
+ put_pid(tty->session);
+ put_pid(tty->pgrp);
+ tty->pgrp = get_pid(task_pgrp(current));
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ tty->session = get_pid(task_session(current));
+ if (current->signal->tty) {
+ printk(KERN_DEBUG "tty not NULL!!\n");
+ tty_kref_put(current->signal->tty);
+ }
+ put_pid(current->signal->tty_old_pgrp);
+ current->signal->tty = tty_kref_get(tty);
+ current->signal->tty_old_pgrp = NULL;
+}
+
+static void proc_set_tty(struct tty_struct *tty)
+{
+ spin_lock_irq(&current->sighand->siglock);
+ __proc_set_tty(tty);
+ spin_unlock_irq(&current->sighand->siglock);
+}
+
+struct tty_struct *get_current_tty(void)
+{
+ struct tty_struct *tty;
+ unsigned long flags;
+
+ spin_lock_irqsave(&current->sighand->siglock, flags);
+ tty = tty_kref_get(current->signal->tty);
+ spin_unlock_irqrestore(&current->sighand->siglock, flags);
+ return tty;
+}
+EXPORT_SYMBOL_GPL(get_current_tty);
+
+static void session_clear_tty(struct pid *session)
+{
+ struct task_struct *p;
+ do_each_pid_task(session, PIDTYPE_SID, p) {
+ proc_clear_tty(p);
+ } while_each_pid_task(session, PIDTYPE_SID, p);
+}
+
/**
* tty_wakeup - request more data
* @tty: terminal
@@ -620,9 +690,6 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
return;
}
- /* some functions below drop BTM, so we need this bit */
- set_bit(TTY_HUPPING, &tty->flags);
-
/* inuse_filps is protected by the single tty lock,
this really needs to change if we want to flush the
workqueue with the lock held */
@@ -647,10 +714,6 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
while (refs--)
tty_kref_put(tty);
- /*
- * it drops BTM and thus races with reopen
- * we protect the race by TTY_HUPPING
- */
tty_ldisc_hangup(tty);
spin_lock_irq(&tty->ctrl_lock);
@@ -682,8 +745,6 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
* can't yet guarantee all that.
*/
set_bit(TTY_HUPPED, &tty->flags);
- clear_bit(TTY_HUPPING, &tty->flags);
-
tty_unlock(tty);
if (f)
@@ -792,14 +853,6 @@ int tty_hung_up_p(struct file *filp)
EXPORT_SYMBOL(tty_hung_up_p);
-static void session_clear_tty(struct pid *session)
-{
- struct task_struct *p;
- do_each_pid_task(session, PIDTYPE_SID, p) {
- proc_clear_tty(p);
- } while_each_pid_task(session, PIDTYPE_SID, p);
-}
-
/**
* disassociate_ctty - disconnect controlling tty
* @on_exit: true if exiting so need to "hang up" the session
@@ -927,7 +980,7 @@ void __stop_tty(struct tty_struct *tty)
return;
tty->stopped = 1;
if (tty->ops->stop)
- (tty->ops->stop)(tty);
+ tty->ops->stop(tty);
}
void stop_tty(struct tty_struct *tty)
@@ -958,7 +1011,7 @@ void __start_tty(struct tty_struct *tty)
return;
tty->stopped = 0;
if (tty->ops->start)
- (tty->ops->start)(tty);
+ tty->ops->start(tty);
tty_wakeup(tty);
}
@@ -1012,7 +1065,7 @@ static ssize_t tty_read(struct file *file, char __user *buf, size_t count,
situation */
ld = tty_ldisc_ref_wait(tty);
if (ld->ops->read)
- i = (ld->ops->read)(tty, file, buf, count);
+ i = ld->ops->read(tty, file, buf, count);
else
i = -EIO;
tty_ldisc_deref(ld);
@@ -1024,14 +1077,12 @@ static ssize_t tty_read(struct file *file, char __user *buf, size_t count,
}
static void tty_write_unlock(struct tty_struct *tty)
- __releases(&tty->atomic_write_lock)
{
mutex_unlock(&tty->atomic_write_lock);
wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
}
static int tty_write_lock(struct tty_struct *tty, int ndelay)
- __acquires(&tty->atomic_write_lock)
{
if (!mutex_trylock(&tty->atomic_write_lock)) {
if (ndelay)
@@ -1146,7 +1197,7 @@ void tty_write_message(struct tty_struct *tty, char *msg)
if (tty) {
mutex_lock(&tty->atomic_write_lock);
tty_lock(tty);
- if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) {
+ if (tty->ops->write && tty->count > 0) {
tty_unlock(tty);
tty->ops->write(tty, msg, strlen(msg));
} else
@@ -1293,19 +1344,24 @@ static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p)
* @driver: the driver for the tty
* @idx: the minor number
*
- * Return the tty, if found or ERR_PTR() otherwise.
+ * Return the tty, if found. If not found, return NULL or ERR_PTR() if the
+ * driver lookup() method returns an error.
*
- * Locking: tty_mutex must be held. If tty is found, the mutex must
- * be held until the 'fast-open' is also done. Will change once we
- * have refcounting in the driver and per driver locking
+ * Locking: tty_mutex must be held. If the tty is found, bump the tty kref.
*/
static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver,
struct inode *inode, int idx)
{
+ struct tty_struct *tty;
+
if (driver->ops->lookup)
- return driver->ops->lookup(driver, inode, idx);
+ tty = driver->ops->lookup(driver, inode, idx);
+ else
+ tty = driver->ttys[idx];
- return driver->ttys[idx];
+ if (!IS_ERR(tty))
+ tty_kref_get(tty);
+ return tty;
}
/**
@@ -1393,29 +1449,21 @@ void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty)
* @tty - the tty to open
*
* Return 0 on success, -errno on error.
+ * Re-opens on master ptys are not allowed and return -EIO.
*
- * Locking: tty_mutex must be held from the time the tty was found
- * till this open completes.
+ * Locking: Caller must hold tty_lock
*/
static int tty_reopen(struct tty_struct *tty)
{
struct tty_driver *driver = tty->driver;
- if (test_bit(TTY_CLOSING, &tty->flags) ||
- test_bit(TTY_HUPPING, &tty->flags))
+ if (!tty->count)
return -EIO;
if (driver->type == TTY_DRIVER_TYPE_PTY &&
- driver->subtype == PTY_TYPE_MASTER) {
- /*
- * special case for PTY masters: only one open permitted,
- * and the slave side open count is incremented as well.
- */
- if (tty->count)
- return -EIO;
+ driver->subtype == PTY_TYPE_MASTER)
+ return -EIO;
- tty->link->count++;
- }
tty->count++;
WARN_ON(!tty->ldisc);
@@ -1535,15 +1583,19 @@ void tty_free_termios(struct tty_struct *tty)
EXPORT_SYMBOL(tty_free_termios);
/**
- * tty_flush_works - flush all works of a tty
- * @tty: tty device to flush works for
+ * tty_flush_works - flush all works of a tty/pty pair
+ * @tty: tty device to flush works for (or either end of a pty pair)
*
- * Sync flush all works belonging to @tty.
+ * Sync flush all works belonging to @tty (and the 'other' tty).
*/
static void tty_flush_works(struct tty_struct *tty)
{
flush_work(&tty->SAK_work);
flush_work(&tty->hangup_work);
+ if (tty->link) {
+ flush_work(&tty->link->SAK_work);
+ flush_work(&tty->link->hangup_work);
+ }
}
/**
@@ -1635,8 +1687,7 @@ static void release_tty(struct tty_struct *tty, int idx)
tty->link->port->itty = NULL;
cancel_work_sync(&tty->port->buf.work);
- if (tty->link)
- tty_kref_put(tty->link);
+ tty_kref_put(tty->link);
tty_kref_put(tty);
}
@@ -1649,8 +1700,7 @@ static void release_tty(struct tty_struct *tty, int idx)
* Performs some paranoid checking before true release of the @tty.
* This is a no-op unless TTY_PARANOIA_CHECK is defined.
*/
-static int tty_release_checks(struct tty_struct *tty, struct tty_struct *o_tty,
- int idx)
+static int tty_release_checks(struct tty_struct *tty, int idx)
{
#ifdef TTY_PARANOIA_CHECK
if (idx < 0 || idx >= tty->driver->num) {
@@ -1669,6 +1719,8 @@ static int tty_release_checks(struct tty_struct *tty, struct tty_struct *o_tty,
return -1;
}
if (tty->driver->other) {
+ struct tty_struct *o_tty = tty->link;
+
if (o_tty != tty->driver->other->ttys[idx]) {
printk(KERN_DEBUG "%s: other->table[%d] not o_tty for (%s)\n",
__func__, idx, tty->name);
@@ -1705,8 +1757,8 @@ static int tty_release_checks(struct tty_struct *tty, struct tty_struct *o_tty,
int tty_release(struct inode *inode, struct file *filp)
{
struct tty_struct *tty = file_tty(filp);
- struct tty_struct *o_tty;
- int pty_master, tty_closing, o_tty_closing, do_sleep;
+ struct tty_struct *o_tty = NULL;
+ int do_sleep, final;
int idx;
char buf[64];
long timeout = 0;
@@ -1721,12 +1773,11 @@ int tty_release(struct inode *inode, struct file *filp)
__tty_fasync(-1, filp, 0);
idx = tty->index;
- pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
- tty->driver->subtype == PTY_TYPE_MASTER);
- /* Review: parallel close */
- o_tty = tty->link;
+ if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+ tty->driver->subtype == PTY_TYPE_MASTER)
+ o_tty = tty->link;
- if (tty_release_checks(tty, o_tty, idx)) {
+ if (tty_release_checks(tty, idx)) {
tty_unlock(tty);
return 0;
}
@@ -1739,7 +1790,9 @@ int tty_release(struct inode *inode, struct file *filp)
if (tty->ops->close)
tty->ops->close(tty, filp);
- tty_unlock(tty);
+ /* If tty is pty master, lock the slave pty (stable lock order) */
+ tty_lock_slave(o_tty);
+
/*
* Sanity check: if tty->count is going to zero, there shouldn't be
* any waiters on tty->read_wait or tty->write_wait. We test the
@@ -1750,25 +1803,13 @@ int tty_release(struct inode *inode, struct file *filp)
* The test for the o_tty closing is necessary, since the master and
* slave sides may close in any order. If the slave side closes out
* first, its count will be one, since the master side holds an open.
- * Thus this test wouldn't be triggered at the time the slave closes,
+ * Thus this test wouldn't be triggered at the time the slave closed,
* so we do it now.
- *
- * Note that it's possible for the tty to be opened again while we're
- * flushing out waiters. By recalculating the closing flags before
- * each iteration we avoid any problems.
*/
while (1) {
- /* Guard against races with tty->count changes elsewhere and
- opens on /dev/tty */
-
- mutex_lock(&tty_mutex);
- tty_lock_pair(tty, o_tty);
- tty_closing = tty->count <= 1;
- o_tty_closing = o_tty &&
- (o_tty->count <= (pty_master ? 1 : 0));
do_sleep = 0;
- if (tty_closing) {
+ if (tty->count <= 1) {
if (waitqueue_active(&tty->read_wait)) {
wake_up_poll(&tty->read_wait, POLLIN);
do_sleep++;
@@ -1778,7 +1819,7 @@ int tty_release(struct inode *inode, struct file *filp)
do_sleep++;
}
}
- if (o_tty_closing) {
+ if (o_tty && o_tty->count <= 1) {
if (waitqueue_active(&o_tty->read_wait)) {
wake_up_poll(&o_tty->read_wait, POLLIN);
do_sleep++;
@@ -1796,8 +1837,6 @@ int tty_release(struct inode *inode, struct file *filp)
printk(KERN_WARNING "%s: %s: read/write wait queue active!\n",
__func__, tty_name(tty, buf));
}
- tty_unlock_pair(tty, o_tty);
- mutex_unlock(&tty_mutex);
schedule_timeout_killable(timeout);
if (timeout < 120 * HZ)
timeout = 2 * timeout + 1;
@@ -1805,15 +1844,7 @@ int tty_release(struct inode *inode, struct file *filp)
timeout = MAX_SCHEDULE_TIMEOUT;
}
- /*
- * The closing flags are now consistent with the open counts on
- * both sides, and we've completed the last operation that could
- * block, so it's safe to proceed with closing.
- *
- * We must *not* drop the tty_mutex until we ensure that a further
- * entry into tty_open can not pick up this tty.
- */
- if (pty_master) {
+ if (o_tty) {
if (--o_tty->count < 0) {
printk(KERN_WARNING "%s: bad pty slave count (%d) for %s\n",
__func__, o_tty->count, tty_name(o_tty, buf));
@@ -1840,21 +1871,11 @@ int tty_release(struct inode *inode, struct file *filp)
/*
* Perform some housekeeping before deciding whether to return.
*
- * Set the TTY_CLOSING flag if this was the last open. In the
- * case of a pty we may have to wait around for the other side
- * to close, and TTY_CLOSING makes sure we can't be reopened.
- */
- if (tty_closing)
- set_bit(TTY_CLOSING, &tty->flags);
- if (o_tty_closing)
- set_bit(TTY_CLOSING, &o_tty->flags);
-
- /*
* If _either_ side is closing, make sure there aren't any
* processes that still think tty or o_tty is their controlling
* tty.
*/
- if (tty_closing || o_tty_closing) {
+ if (!tty->count) {
read_lock(&tasklist_lock);
session_clear_tty(tty->session);
if (o_tty)
@@ -1862,13 +1883,16 @@ int tty_release(struct inode *inode, struct file *filp)
read_unlock(&tasklist_lock);
}
- mutex_unlock(&tty_mutex);
- tty_unlock_pair(tty, o_tty);
- /* At this point the TTY_CLOSING flag should ensure a dead tty
+ /* check whether both sides are closing ... */
+ final = !tty->count && !(o_tty && o_tty->count);
+
+ tty_unlock_slave(o_tty);
+ tty_unlock(tty);
+
+ /* At this point, the tty->count == 0 should ensure a dead tty
cannot be re-opened by a racing opener */
- /* check whether both sides are closing ... */
- if (!tty_closing || (o_tty && !o_tty_closing))
+ if (!final)
return 0;
#ifdef TTY_DEBUG_HANGUP
@@ -1877,12 +1901,10 @@ int tty_release(struct inode *inode, struct file *filp)
/*
* Ask the line discipline code to release its structures
*/
- tty_ldisc_release(tty, o_tty);
+ tty_ldisc_release(tty);
/* Wait for pending work before tty destruction commmences */
tty_flush_works(tty);
- if (o_tty)
- tty_flush_works(o_tty);
#ifdef TTY_DEBUG_HANGUP
printk(KERN_DEBUG "%s: %s: freeing structure...\n", __func__, tty_name(tty, buf));
@@ -1901,20 +1923,20 @@ int tty_release(struct inode *inode, struct file *filp)
}
/**
- * tty_open_current_tty - get tty of current task for open
+ * tty_open_current_tty - get locked tty of current task
* @device: device number
* @filp: file pointer to tty
- * @return: tty of the current task iff @device is /dev/tty
+ * @return: locked tty of the current task iff @device is /dev/tty
+ *
+ * Performs a re-open of the current task's controlling tty.
*
* We cannot return driver and index like for the other nodes because
* devpts will not work then. It expects inodes to be from devpts FS.
- *
- * We need to move to returning a refcounted object from all the lookup
- * paths including this one.
*/
static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp)
{
struct tty_struct *tty;
+ int retval;
if (device != MKDEV(TTYAUX_MAJOR, 0))
return NULL;
@@ -1925,9 +1947,14 @@ static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp)
filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */
/* noctty = 1; */
- tty_kref_put(tty);
- /* FIXME: we put a reference and return a TTY! */
- /* This is only safe because the caller holds tty_mutex */
+ tty_lock(tty);
+ tty_kref_put(tty); /* safe to drop the kref now */
+
+ retval = tty_reopen(tty);
+ if (retval < 0) {
+ tty_unlock(tty);
+ tty = ERR_PTR(retval);
+ }
return tty;
}
@@ -2025,13 +2052,9 @@ retry_open:
index = -1;
retval = 0;
- mutex_lock(&tty_mutex);
- /* This is protected by the tty_mutex */
tty = tty_open_current_tty(device, filp);
- if (IS_ERR(tty)) {
- retval = PTR_ERR(tty);
- goto err_unlock;
- } else if (!tty) {
+ if (!tty) {
+ mutex_lock(&tty_mutex);
driver = tty_lookup_driver(device, filp, &noctty, &index);
if (IS_ERR(driver)) {
retval = PTR_ERR(driver);
@@ -2044,21 +2067,25 @@ retry_open:
retval = PTR_ERR(tty);
goto err_unlock;
}
- }
- if (tty) {
- tty_lock(tty);
- retval = tty_reopen(tty);
- if (retval < 0) {
- tty_unlock(tty);
- tty = ERR_PTR(retval);
+ if (tty) {
+ mutex_unlock(&tty_mutex);
+ tty_lock(tty);
+ /* safe to drop the kref from tty_driver_lookup_tty() */
+ tty_kref_put(tty);
+ retval = tty_reopen(tty);
+ if (retval < 0) {
+ tty_unlock(tty);
+ tty = ERR_PTR(retval);
+ }
+ } else { /* Returns with the tty_lock held for now */
+ tty = tty_init_dev(driver, index);
+ mutex_unlock(&tty_mutex);
}
- } else /* Returns with the tty_lock held for now */
- tty = tty_init_dev(driver, index);
- mutex_unlock(&tty_mutex);
- if (driver)
tty_driver_kref_put(driver);
+ }
+
if (IS_ERR(tty)) {
retval = PTR_ERR(tty);
goto err_file;
@@ -2100,25 +2127,23 @@ retry_open:
/*
* Need to reset f_op in case a hangup happened.
*/
- if (filp->f_op == &hung_up_tty_fops)
+ if (tty_hung_up_p(filp))
filp->f_op = &tty_fops;
goto retry_open;
}
clear_bit(TTY_HUPPED, &tty->flags);
- tty_unlock(tty);
- mutex_lock(&tty_mutex);
- tty_lock(tty);
+ read_lock(&tasklist_lock);
spin_lock_irq(&current->sighand->siglock);
if (!noctty &&
current->signal->leader &&
!current->signal->tty &&
tty->session == NULL)
- __proc_set_tty(current, tty);
+ __proc_set_tty(tty);
spin_unlock_irq(&current->sighand->siglock);
+ read_unlock(&tasklist_lock);
tty_unlock(tty);
- mutex_unlock(&tty_mutex);
return 0;
err_unlock:
mutex_unlock(&tty_mutex);
@@ -2155,7 +2180,7 @@ static unsigned int tty_poll(struct file *filp, poll_table *wait)
ld = tty_ldisc_ref_wait(tty);
if (ld->ops->poll)
- ret = (ld->ops->poll)(tty, filp, wait);
+ ret = ld->ops->poll(tty, filp, wait);
tty_ldisc_deref(ld);
return ret;
}
@@ -2283,18 +2308,14 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
int tty_do_resize(struct tty_struct *tty, struct winsize *ws)
{
struct pid *pgrp;
- unsigned long flags;
/* Lock the tty */
mutex_lock(&tty->winsize_mutex);
if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
goto done;
- /* Get the PID values and reference them so we can
- avoid holding the tty ctrl lock while sending signals */
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- pgrp = get_pid(tty->pgrp);
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ /* Signal the foreground process group */
+ pgrp = tty_get_pgrp(tty);
if (pgrp)
kill_pgrp(pgrp, SIGWINCH, 1);
put_pid(pgrp);
@@ -2403,7 +2424,7 @@ static int fionbio(struct file *file, int __user *p)
* leader to set this tty as the controlling tty for the session.
*
* Locking:
- * Takes tty_mutex() to protect tty instance
+ * Takes tty_lock() to serialize proc_set_tty() for this tty
* Takes tasklist_lock internally to walk sessions
* Takes ->siglock() when updating signal->tty
*/
@@ -2411,10 +2432,13 @@ static int fionbio(struct file *file, int __user *p)
static int tiocsctty(struct tty_struct *tty, int arg)
{
int ret = 0;
+
+ tty_lock(tty);
+ read_lock(&tasklist_lock);
+
if (current->signal->leader && (task_session(current) == tty->session))
- return ret;
+ goto unlock;
- mutex_lock(&tty_mutex);
/*
* The process must be a session leader and
* not have a controlling tty already.
@@ -2433,17 +2457,16 @@ static int tiocsctty(struct tty_struct *tty, int arg)
/*
* Steal it away
*/
- read_lock(&tasklist_lock);
session_clear_tty(tty->session);
- read_unlock(&tasklist_lock);
} else {
ret = -EPERM;
goto unlock;
}
}
- proc_set_tty(current, tty);
+ proc_set_tty(tty);
unlock:
- mutex_unlock(&tty_mutex);
+ read_unlock(&tasklist_lock);
+ tty_unlock(tty);
return ret;
}
@@ -2468,6 +2491,27 @@ struct pid *tty_get_pgrp(struct tty_struct *tty)
}
EXPORT_SYMBOL_GPL(tty_get_pgrp);
+/*
+ * This checks not only the pgrp, but falls back on the pid if no
+ * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
+ * without this...
+ *
+ * The caller must hold rcu lock or the tasklist lock.
+ */
+static struct pid *session_of_pgrp(struct pid *pgrp)
+{
+ struct task_struct *p;
+ struct pid *sid = NULL;
+
+ p = pid_task(pgrp, PIDTYPE_PGID);
+ if (p == NULL)
+ p = pid_task(pgrp, PIDTYPE_PID);
+ if (p != NULL)
+ sid = task_session(p);
+
+ return sid;
+}
+
/**
* tiocgpgrp - get process group
* @tty: tty passed by user
@@ -2714,23 +2758,35 @@ static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
return 0;
}
-struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
+static void tty_warn_deprecated_flags(struct serial_struct __user *ss)
{
- if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
- tty->driver->subtype == PTY_TYPE_MASTER)
- tty = tty->link;
- return tty;
+ static DEFINE_RATELIMIT_STATE(depr_flags,
+ DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+ char comm[TASK_COMM_LEN];
+ int flags;
+
+ if (get_user(flags, &ss->flags))
+ return;
+
+ flags &= ASYNC_DEPRECATED;
+
+ if (flags && __ratelimit(&depr_flags))
+ pr_warning("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n",
+ __func__, get_task_comm(comm, current), flags);
}
-EXPORT_SYMBOL(tty_pair_get_tty);
-struct tty_struct *tty_pair_get_pty(struct tty_struct *tty)
+/*
+ * if pty, return the slave side (real_tty)
+ * otherwise, return self
+ */
+static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
{
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
tty->driver->subtype == PTY_TYPE_MASTER)
- return tty;
- return tty->link;
+ tty = tty->link;
+ return tty;
}
-EXPORT_SYMBOL(tty_pair_get_pty);
/*
* Split this up, as gcc can choke on it otherwise..
@@ -2859,13 +2915,16 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case TCIFLUSH:
case TCIOFLUSH:
/* flush tty buffer and allow ldisc to process ioctl */
- tty_buffer_flush(tty);
+ tty_buffer_flush(tty, NULL);
break;
}
break;
+ case TIOCSSERIAL:
+ tty_warn_deprecated_flags(p);
+ break;
}
if (tty->ops->ioctl) {
- retval = (tty->ops->ioctl)(tty, cmd, arg);
+ retval = tty->ops->ioctl(tty, cmd, arg);
if (retval != -ENOIOCTLCMD)
return retval;
}
@@ -2892,7 +2951,7 @@ static long tty_compat_ioctl(struct file *file, unsigned int cmd,
return -EINVAL;
if (tty->ops->compat_ioctl) {
- retval = (tty->ops->compat_ioctl)(tty, cmd, arg);
+ retval = tty->ops->compat_ioctl(tty, cmd, arg);
if (retval != -ENOIOCTLCMD)
return retval;
}
@@ -3443,59 +3502,6 @@ dev_t tty_devnum(struct tty_struct *tty)
}
EXPORT_SYMBOL(tty_devnum);
-void proc_clear_tty(struct task_struct *p)
-{
- unsigned long flags;
- struct tty_struct *tty;
- spin_lock_irqsave(&p->sighand->siglock, flags);
- tty = p->signal->tty;
- p->signal->tty = NULL;
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
- tty_kref_put(tty);
-}
-
-/* Called under the sighand lock */
-
-static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
-{
- if (tty) {
- unsigned long flags;
- /* We should not have a session or pgrp to put here but.... */
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- put_pid(tty->session);
- put_pid(tty->pgrp);
- tty->pgrp = get_pid(task_pgrp(tsk));
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- tty->session = get_pid(task_session(tsk));
- if (tsk->signal->tty) {
- printk(KERN_DEBUG "tty not NULL!!\n");
- tty_kref_put(tsk->signal->tty);
- }
- }
- put_pid(tsk->signal->tty_old_pgrp);
- tsk->signal->tty = tty_kref_get(tty);
- tsk->signal->tty_old_pgrp = NULL;
-}
-
-static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
-{
- spin_lock_irq(&tsk->sighand->siglock);
- __proc_set_tty(tsk, tty);
- spin_unlock_irq(&tsk->sighand->siglock);
-}
-
-struct tty_struct *get_current_tty(void)
-{
- struct tty_struct *tty;
- unsigned long flags;
-
- spin_lock_irqsave(&current->sighand->siglock, flags);
- tty = tty_kref_get(current->signal->tty);
- spin_unlock_irqrestore(&current->sighand->siglock, flags);
- return tty;
-}
-EXPORT_SYMBOL_GPL(get_current_tty);
-
void tty_default_fops(struct file_operations *fops)
{
*fops = tty_fops;