void disassociate_ctty(int on_exit)
{
struct tty_struct *tty;
- struct pid *tty_pgrp = NULL;
if (!current->signal->leader)
return;
tty = get_current_tty();
if (tty) {
- tty_pgrp = get_pid(tty->pgrp);
+ struct pid *tty_pgrp = get_pid(tty->pgrp);
if (on_exit) {
if (tty->driver->type != TTY_DRIVER_TYPE_PTY)
tty_vhangup(tty);
}
tty_kref_put(tty);
+ if (tty_pgrp) {
+ kill_pgrp(tty_pgrp, SIGHUP, on_exit);
+ if (!on_exit)
+ kill_pgrp(tty_pgrp, SIGCONT, on_exit);
+ put_pid(tty_pgrp);
+ }
} else if (on_exit) {
struct pid *old_pgrp;
spin_lock_irq(¤t->sighand->siglock);
}
return;
}
- if (tty_pgrp) {
- kill_pgrp(tty_pgrp, SIGHUP, on_exit);
- if (!on_exit)
- kill_pgrp(tty_pgrp, SIGCONT, on_exit);
- put_pid(tty_pgrp);
- }
spin_lock_irq(¤t->sighand->siglock);
put_pid(current->signal->tty_old_pgrp);
tty_kref_put(tty);
}
+/**
+ * tty_release_checks - check a tty before real release
+ * @tty: tty to check
+ * @o_tty: link of @tty (if any)
+ * @idx: index of the tty
+ *
+ * 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)
+{
+#ifdef TTY_PARANOIA_CHECK
+ if (idx < 0 || idx >= tty->driver->num) {
+ printk(KERN_DEBUG "%s: bad idx when trying to free (%s)\n",
+ __func__, tty->name);
+ return -1;
+ }
+
+ /* not much to check for devpts */
+ if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)
+ return 0;
+
+ if (tty != tty->driver->ttys[idx]) {
+ printk(KERN_DEBUG "%s: driver.table[%d] not tty for (%s)\n",
+ __func__, idx, tty->name);
+ return -1;
+ }
+ if (tty->termios != tty->driver->termios[idx]) {
+ printk(KERN_DEBUG "%s: driver.termios[%d] not termios for (%s)\n",
+ __func__, idx, tty->name);
+ return -1;
+ }
+ if (tty->driver->other) {
+ 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);
+ return -1;
+ }
+ if (o_tty->termios != tty->driver->other->termios[idx]) {
+ printk(KERN_DEBUG "%s: other->termios[%d] not o_termios for (%s)\n",
+ __func__, idx, tty->name);
+ return -1;
+ }
+ if (o_tty->link != tty) {
+ printk(KERN_DEBUG "%s: bad pty pointers\n", __func__);
+ return -1;
+ }
+ }
+#endif
+ return 0;
+}
+
/**
* tty_release - vfs callback for close
* @inode: inode of tty
int idx;
char buf[64];
- if (tty_paranoia_check(tty, inode, "tty_release_dev"))
+ if (tty_paranoia_check(tty, inode, __func__))
return 0;
tty_lock();
- check_tty_count(tty, "tty_release_dev");
+ check_tty_count(tty, __func__);
__tty_fasync(-1, filp, 0);
devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0;
o_tty = tty->link;
-#ifdef TTY_PARANOIA_CHECK
- if (idx < 0 || idx >= tty->driver->num) {
- printk(KERN_DEBUG "tty_release_dev: bad idx when trying to "
- "free (%s)\n", tty->name);
+ if (tty_release_checks(tty, o_tty, idx)) {
tty_unlock();
return 0;
}
- if (!devpts) {
- if (tty != tty->driver->ttys[idx]) {
- tty_unlock();
- printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty "
- "for (%s)\n", idx, tty->name);
- return 0;
- }
- if (tty->termios != tty->driver->termios[idx]) {
- tty_unlock();
- printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios "
- "for (%s)\n",
- idx, tty->name);
- return 0;
- }
- }
-#endif
#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...",
- tty_name(tty, buf), tty->count);
+ printk(KERN_DEBUG "%s: %s (tty count=%d)...\n", __func__,
+ tty_name(tty, buf), tty->count);
#endif
-#ifdef TTY_PARANOIA_CHECK
- if (tty->driver->other &&
- !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
- if (o_tty != tty->driver->other->ttys[idx]) {
- tty_unlock();
- printk(KERN_DEBUG "tty_release_dev: other->table[%d] "
- "not o_tty for (%s)\n",
- idx, tty->name);
- return 0 ;
- }
- if (o_tty->termios != tty->driver->other->termios[idx]) {
- tty_unlock();
- printk(KERN_DEBUG "tty_release_dev: other->termios[%d] "
- "not o_termios for (%s)\n",
- idx, tty->name);
- return 0;
- }
- if (o_tty->link != tty) {
- tty_unlock();
- printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n");
- return 0;
- }
- }
-#endif
if (tty->ops->close)
tty->ops->close(tty, filp);
if (!do_sleep)
break;
- printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue "
- "active!\n", tty_name(tty, buf));
+ printk(KERN_WARNING "%s: %s: read/write wait queue active!\n",
+ __func__, tty_name(tty, buf));
tty_unlock();
mutex_unlock(&tty_mutex);
schedule();
*/
if (pty_master) {
if (--o_tty->count < 0) {
- printk(KERN_WARNING "tty_release_dev: bad pty slave count "
- "(%d) for %s\n",
- o_tty->count, tty_name(o_tty, buf));
+ printk(KERN_WARNING "%s: bad pty slave count (%d) for %s\n",
+ __func__, o_tty->count, tty_name(o_tty, buf));
o_tty->count = 0;
}
}
if (--tty->count < 0) {
- printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n",
- tty->count, tty_name(tty, buf));
+ printk(KERN_WARNING "%s: bad tty->count (%d) for %s\n",
+ __func__, tty->count, tty_name(tty, buf));
tty->count = 0;
}
}
#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "freeing tty structure...");
+ printk(KERN_DEBUG "%s: freeing tty structure...\n", __func__);
#endif
/*
* Ask the line discipline code to release its structures
return 0;
}
+/**
+ * tty_open_current_tty - get tty of current task for open
+ * @device: device number
+ * @filp: file pointer to tty
+ * @return: tty of the current task iff @device is /dev/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.
+ */
+static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp)
+{
+ struct tty_struct *tty;
+
+ if (device != MKDEV(TTYAUX_MAJOR, 0))
+ return NULL;
+
+ tty = get_current_tty();
+ if (!tty)
+ return ERR_PTR(-ENXIO);
+
+ 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! */
+ return tty;
+}
+
+/**
+ * tty_lookup_driver - lookup a tty driver for a given device file
+ * @device: device number
+ * @filp: file pointer to tty
+ * @noctty: set if the device should not become a controlling tty
+ * @index: index for the device in the @return driver
+ * @return: driver for this inode (with increased refcount)
+ *
+ * If @return is not erroneous, the caller is responsible to decrement the
+ * refcount by tty_driver_kref_put.
+ *
+ * Locking: tty_mutex protects get_tty_driver
+ */
+static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp,
+ int *noctty, int *index)
+{
+ struct tty_driver *driver;
+
+ switch (device) {
+#ifdef CONFIG_VT
+ case MKDEV(TTY_MAJOR, 0): {
+ extern struct tty_driver *console_driver;
+ driver = tty_driver_kref_get(console_driver);
+ *index = fg_console;
+ *noctty = 1;
+ break;
+ }
+#endif
+ case MKDEV(TTYAUX_MAJOR, 1): {
+ struct tty_driver *console_driver = console_device(index);
+ if (console_driver) {
+ driver = tty_driver_kref_get(console_driver);
+ if (driver) {
+ /* Don't let /dev/console block */
+ filp->f_flags |= O_NONBLOCK;
+ *noctty = 1;
+ break;
+ }
+ }
+ return ERR_PTR(-ENODEV);
+ }
+ default:
+ driver = get_tty_driver(device, index);
+ if (!driver)
+ return ERR_PTR(-ENODEV);
+ break;
+ }
+ return driver;
+}
+
/**
* tty_open - open a tty device
* @inode: inode of device file
* The termios state of a pty is reset on first open so that
* settings don't persist across reuse.
*
- * Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work.
+ * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev.
* tty->count should protect the rest.
* ->siglock protects ->signal/->sighand
*/
static int tty_open(struct inode *inode, struct file *filp)
{
- struct tty_struct *tty = NULL;
+ struct tty_struct *tty;
int noctty, retval;
- struct tty_driver *driver;
+ struct tty_driver *driver = NULL;
int index;
dev_t device = inode->i_rdev;
unsigned saved_flags = filp->f_flags;
mutex_lock(&tty_mutex);
tty_lock();
- if (device == MKDEV(TTYAUX_MAJOR, 0)) {
- tty = get_current_tty();
- if (!tty) {
- tty_unlock();
- mutex_unlock(&tty_mutex);
- tty_free_file(filp);
- return -ENXIO;
- }
- driver = tty_driver_kref_get(tty->driver);
- index = tty->index;
- filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */
- /* noctty = 1; */
- /* FIXME: Should we take a driver reference ? */
- tty_kref_put(tty);
- goto got_driver;
- }
-#ifdef CONFIG_VT
- if (device == MKDEV(TTY_MAJOR, 0)) {
- extern struct tty_driver *console_driver;
- driver = tty_driver_kref_get(console_driver);
- index = fg_console;
- noctty = 1;
- goto got_driver;
- }
-#endif
- if (device == MKDEV(TTYAUX_MAJOR, 1)) {
- struct tty_driver *console_driver = console_device(&index);
- if (console_driver) {
- driver = tty_driver_kref_get(console_driver);
- if (driver) {
- /* Don't let /dev/console block */
- filp->f_flags |= O_NONBLOCK;
- noctty = 1;
- goto got_driver;
- }
+ tty = tty_open_current_tty(device, filp);
+ if (IS_ERR(tty)) {
+ retval = PTR_ERR(tty);
+ goto err_unlock;
+ } else if (!tty) {
+ driver = tty_lookup_driver(device, filp, &noctty, &index);
+ if (IS_ERR(driver)) {
+ retval = PTR_ERR(driver);
+ goto err_unlock;
}
- tty_unlock();
- mutex_unlock(&tty_mutex);
- tty_free_file(filp);
- return -ENODEV;
- }
- driver = get_tty_driver(device, &index);
- if (!driver) {
- tty_unlock();
- mutex_unlock(&tty_mutex);
- tty_free_file(filp);
- return -ENODEV;
- }
-got_driver:
- if (!tty) {
/* check whether we're reopening an existing tty */
tty = tty_driver_lookup_tty(driver, inode, index);
-
if (IS_ERR(tty)) {
- tty_unlock();
- mutex_unlock(&tty_mutex);
- tty_driver_kref_put(driver);
- tty_free_file(filp);
- return PTR_ERR(tty);
+ retval = PTR_ERR(tty);
+ goto err_unlock;
}
}
tty = tty_init_dev(driver, index, 0);
mutex_unlock(&tty_mutex);
- tty_driver_kref_put(driver);
+ if (driver)
+ tty_driver_kref_put(driver);
if (IS_ERR(tty)) {
tty_unlock();
- tty_free_file(filp);
- return PTR_ERR(tty);
+ retval = PTR_ERR(tty);
+ goto err_file;
}
tty_add_file(tty, filp);
- check_tty_count(tty, "tty_open");
+ check_tty_count(tty, __func__);
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
tty->driver->subtype == PTY_TYPE_MASTER)
noctty = 1;
#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "opening %s...", tty->name);
+ printk(KERN_DEBUG "%s: opening %s...\n", __func__, tty->name);
#endif
if (tty->ops->open)
retval = tty->ops->open(tty, filp);
if (retval) {
#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "error %d in opening %s...", retval,
- tty->name);
+ printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__,
+ retval, tty->name);
#endif
tty_unlock(); /* need to call tty_release without BTM */
tty_release(inode, filp);
tty_unlock();
mutex_unlock(&tty_mutex);
return 0;
+err_unlock:
+ tty_unlock();
+ mutex_unlock(&tty_mutex);
+ /* after locks to avoid deadlock */
+ if (!IS_ERR_OR_NULL(driver))
+ tty_driver_kref_put(driver);
+err_file:
+ tty_free_file(filp);
+ return retval;
}
projects / firefly-linux-kernel-4.4.55.git / blobdiff