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 void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
/**
* alloc_tty_struct - allocate a tty object
/* If we have a running line discipline it may need kicking */
tty_wakeup(tty);
- wake_up_interruptible(&tty->write_wait);
}
EXPORT_SYMBOL(start_tty);
/*
* 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)) {
/*
* 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) {
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
* 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)
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
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 */
* 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
int session;
int i;
struct file *filp;
- struct tty_ldisc *disc;
struct fdtable *fdt;
if (!tty)
return;
session = tty->session;
- /* We don't want an ldisc switch during this */
- disc = tty_ldisc_ref(tty);
- if (disc && disc->flush_buffer)
- disc->flush_buffer(tty);
- tty_ldisc_deref(disc);
+ tty_ldisc_flush(tty);
if (tty->driver->flush_buffer)
tty->driver->flush_buffer(tty);
#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,
{
if (!tty)
return;
- PREPARE_WORK(&tty->SAK_work, __do_SAK);
+ PREPARE_WORK(&tty->SAK_work, do_SAK_work);
schedule_work(&tty->SAK_work);
}
}
EXPORT_SYMBOL(proc_clear_tty);
-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)
{
if (tty) {
tty->session = process_session(tsk);