*
* Added support for a Unix98-style ptmx device.
* -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
- * Added TTY_DO_WRITE_WAKEUP to enable n_tty to send POLL_OUT to
- * waiting writers -- Sapan Bhatia <sapan@corewars.org>
- *
*
+ * When reading this code see also fs/devpts. In particular note that the
+ * driver_data field is used by the devpts side as a binding to the devpts
+ * inode.
*/
-#include <linux/module.h> /* For EXPORT_SYMBOL */
+#include <linux/module.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/device.h>
-
-#include <asm/uaccess.h>
-#include <asm/system.h>
+#include <linux/uaccess.h>
#include <linux/bitops.h>
#include <linux/devpts_fs.h>
+#include <asm/system.h>
+
/* These are global because they are accessed in tty_io.c */
#ifdef CONFIG_UNIX98_PTYS
-struct tty_driver *ptm_driver;
+static struct tty_driver *ptm_driver;
static struct tty_driver *pts_driver;
#endif
-static void pty_close(struct tty_struct * tty, struct file * filp)
+static void pty_close(struct tty_struct *tty, struct file *filp)
{
- if (!tty)
- return;
- if (tty->driver->subtype == PTY_TYPE_MASTER) {
- if (tty->count > 1)
- printk("master pty_close: count = %d!!\n", tty->count);
- } else {
+ BUG_ON(!tty);
+ if (tty->driver->subtype == PTY_TYPE_MASTER)
+ WARN_ON(tty->count > 1);
+ else {
if (tty->count > 2)
return;
}
set_bit(TTY_OTHER_CLOSED, &tty->flags);
#ifdef CONFIG_UNIX98_PTYS
if (tty->driver == ptm_driver)
- devpts_pty_kill(tty->index);
+ devpts_pty_kill(tty->link);
#endif
tty_vhangup(tty->link);
}
* The unthrottle routine is called by the line discipline to signal
* that it can receive more characters. For PTY's, the TTY_THROTTLED
* flag is always set, to force the line discipline to always call the
- * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
+ * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
* characters in the queue. This is necessary since each time this
* happens, we need to wake up any sleeping processes that could be
* (1) trying to send data to the pty, or (2) waiting in wait_until_sent()
* for the pty buffer to be drained.
*/
-static void pty_unthrottle(struct tty_struct * tty)
+static void pty_unthrottle(struct tty_struct *tty)
{
struct tty_struct *o_tty = tty->link;
}
/*
- * WSH 05/24/97: modified to
+ * WSH 05/24/97: modified to
* (1) use space in tty->flip instead of a shared temp buffer
* The flip buffers aren't being used for a pty, so there's lots
* of space available. The buffer is protected by a per-pty
* not our partners. We can't just take the other one blindly without
* risking deadlocks.
*/
-static int pty_write(struct tty_struct * tty, const unsigned char *buf, int count)
+static int pty_write(struct tty_struct *tty, const unsigned char *buf,
+ int count)
{
struct tty_struct *to = tty->link;
int c;
if (c > count)
c = count;
to->ldisc.ops->receive_buf(to, buf, NULL, c);
-
+
return c;
}
/*
* WSH 05/24/97: Modified for asymmetric MASTER/SLAVE behavior
- * The chars_in_buffer() value is used by the ldisc select() function
+ * The chars_in_buffer() value is used by the ldisc select() function
* to hold off writing when chars_in_buffer > WAKEUP_CHARS (== 256).
* The pty driver chars_in_buffer() Master/Slave must behave differently:
*
* The Master side needs to allow typed-ahead commands to accumulate
* while being canonicalized, so we report "our buffer" as empty until
* some threshold is reached, and then report the count. (Any count >
- * WAKEUP_CHARS is regarded by select() as "full".) To avoid deadlock
- * the count returned must be 0 if no canonical data is available to be
+ * WAKEUP_CHARS is regarded by select() as "full".) To avoid deadlock
+ * the count returned must be 0 if no canonical data is available to be
* read. (The N_TTY ldisc.chars_in_buffer now knows this.)
- *
+ *
* The Slave side passes all characters in raw mode to the Master side's
* buffer where they can be read immediately, so in this case we can
* return the true count in the buffer.
/* The ldisc must report 0 if no characters available to be read */
count = to->ldisc.ops->chars_in_buffer(to);
- if (tty->driver->subtype == PTY_TYPE_SLAVE) return count;
+ if (tty->driver->subtype == PTY_TYPE_SLAVE)
+ return count;
- /* Master side driver ... if the other side's read buffer is less than
+ /* Master side driver ... if the other side's read buffer is less than
* half full, return 0 to allow writers to proceed; otherwise return
- * the count. This leaves a comfortable margin to avoid overflow,
+ * the count. This leaves a comfortable margin to avoid overflow,
* and still allows half a buffer's worth of typed-ahead commands.
*/
- return ((count < N_TTY_BUF_SIZE/2) ? 0 : count);
+ return (count < N_TTY_BUF_SIZE/2) ? 0 : count;
}
/* Set the lock flag on a pty */
-static int pty_set_lock(struct tty_struct *tty, int __user * arg)
+static int pty_set_lock(struct tty_struct *tty, int __user *arg)
{
int val;
- if (get_user(val,arg))
+ if (get_user(val, arg))
return -EFAULT;
if (val)
set_bit(TTY_PTY_LOCK, &tty->flags);
{
struct tty_struct *to = tty->link;
unsigned long flags;
-
+
if (!to)
return;
-
+
if (to->ldisc.ops->flush_buffer)
to->ldisc.ops->flush_buffer(to);
-
+
if (to->packet) {
spin_lock_irqsave(&tty->ctrl_lock, flags);
tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
}
}
-static int pty_open(struct tty_struct *tty, struct file * filp)
+static int pty_open(struct tty_struct *tty, struct file *filp)
{
int retval = -ENODEV;
clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
set_bit(TTY_THROTTLED, &tty->flags);
- set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
retval = 0;
out:
return retval;
}
-static void pty_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
+static void pty_set_termios(struct tty_struct *tty,
+ struct ktermios *old_termios)
{
- tty->termios->c_cflag &= ~(CSIZE | PARENB);
- tty->termios->c_cflag |= (CS8 | CREAD);
+ tty->termios->c_cflag &= ~(CSIZE | PARENB);
+ tty->termios->c_cflag |= (CS8 | CREAD);
+}
+
+/**
+ * pty_do_resize - resize event
+ * @tty: tty being resized
+ * @ws: window size being set.
+ *
+ * Update the termios variables and send the neccessary signals to
+ * peform a terminal resize correctly
+ */
+
+int pty_resize(struct tty_struct *tty, struct winsize *ws)
+{
+ struct pid *pgrp, *rpgrp;
+ unsigned long flags;
+ struct tty_struct *pty = tty->link;
+
+ /* For a PTY we need to lock the tty side */
+ mutex_lock(&tty->termios_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.
+ We need to lock these individually however. */
+
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ pgrp = get_pid(tty->pgrp);
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+ spin_lock_irqsave(&pty->ctrl_lock, flags);
+ rpgrp = get_pid(pty->pgrp);
+ spin_unlock_irqrestore(&pty->ctrl_lock, flags);
+
+ if (pgrp)
+ kill_pgrp(pgrp, SIGWINCH, 1);
+ if (rpgrp != pgrp && rpgrp)
+ kill_pgrp(rpgrp, SIGWINCH, 1);
+
+ put_pid(pgrp);
+ put_pid(rpgrp);
+
+ tty->winsize = *ws;
+ pty->winsize = *ws; /* Never used so will go away soon */
+done:
+ mutex_unlock(&tty->termios_mutex);
+ return 0;
}
static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
tty_free_termios(tty);
goto free_mem_out;
}
-
+
/*
* Everything allocated ... set up the o_tty structure.
*/
.chars_in_buffer = pty_chars_in_buffer,
.unthrottle = pty_unthrottle,
.set_termios = pty_set_termios,
+ .resize = pty_resize
};
/* Traditional BSD devices */
.unthrottle = pty_unthrottle,
.set_termios = pty_set_termios,
.ioctl = pty_bsd_ioctl,
+ .resize = pty_resize
};
static void __init legacy_pty_init(void)
* Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
*/
int pty_limit = NR_UNIX98_PTY_DEFAULT;
-static int pty_limit_min = 0;
+static int pty_limit_min;
static int pty_limit_max = NR_UNIX98_PTY_MAX;
-static int pty_count = 0;
+static int pty_count;
static struct cdev ptmx_cdev;
* This provides our locking.
*/
-static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, int idx)
+static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
+ struct inode *ptm_inode, int idx)
{
- struct tty_struct *tty = devpts_get_tty(idx);
+ struct tty_struct *tty = devpts_get_tty(ptm_inode, idx);
if (tty)
tty = tty->link;
return tty;
* This provides our locking.
*/
-static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, int idx)
+static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
+ struct inode *pts_inode, int idx)
{
- struct tty_struct *tty = devpts_get_tty(idx);
+ struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
/* Master must be open before slave */
if (!tty)
return ERR_PTR(-EIO);
{
/* We have our own method as we don't use the tty index */
kfree(tty->termios);
- kfree(tty->termios_locked);
}
/* We have no need to install and remove our tty objects as devpts does all
}
initialize_tty_struct(o_tty, driver->other, idx);
- tty->termios = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
+ tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
if (tty->termios == NULL)
goto free_mem_out;
*tty->termios = driver->init_termios;
- tty->termios_locked = kzalloc(sizeof(struct ktermios), GFP_KERNEL);
- if (tty->termios_locked == NULL)
- goto free_mem_out;
- o_tty->termios = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
+ tty->termios_locked = tty->termios + 1;
+
+ o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
if (o_tty->termios == NULL)
goto free_mem_out;
*o_tty->termios = driver->other->init_termios;
- o_tty->termios_locked = kzalloc(sizeof(struct ktermios), GFP_KERNEL);
- if (o_tty->termios_locked == NULL)
- goto free_mem_out;
+ o_tty->termios_locked = o_tty->termios + 1;
tty_driver_kref_get(driver->other);
if (driver->subtype == PTY_TYPE_MASTER)
kfree(o_tty->termios);
module_put(o_tty->driver->owner);
free_tty_struct(o_tty);
- kfree(tty->termios_locked);
kfree(tty->termios);
- free_tty_struct(tty);
- module_put(driver->owner);
return -ENOMEM;
}
.unthrottle = pty_unthrottle,
.set_termios = pty_set_termios,
.ioctl = pty_unix98_ioctl,
- .shutdown = pty_unix98_shutdown
+ .shutdown = pty_unix98_shutdown,
+ .resize = pty_resize
};
static const struct tty_operations pty_unix98_ops = {
nonseekable_open(inode, filp);
/* find a device that is not in use. */
- index = devpts_new_index();
+ index = devpts_new_index(inode);
if (index < 0)
return index;
filp->private_data = tty;
file_move(filp, &tty->tty_files);
- retval = devpts_pty_new(tty->link);
+ retval = devpts_pty_new(inode, tty->link);
if (retval)
goto out1;
tty_release_dev(filp);
return retval;
out:
- devpts_kill_index(index);
+ devpts_kill_index(inode, index);
return retval;
}
TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
pts_driver->other = ptm_driver;
tty_set_operations(pts_driver, &pty_unix98_ops);
-
+
if (tty_register_driver(ptm_driver))
panic("Couldn't register Unix98 ptm driver");
if (tty_register_driver(pts_driver))
panic("Couldn't register Unix98 pts driver");
- register_sysctl_table(pty_root_table);
+ register_sysctl_table(pty_root_table);
/* Now create the /dev/ptmx special device */
tty_default_fops(&ptmx_fops);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff