mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 08:19:28 +00:00
![Yang Yingliang](/assets/img/avatar_default.png)
Fix the following make W=1 kernel build warning: drivers/tty/pty.c:307: warning: expecting prototype for pty_do_resize(). Prototype was for pty_resize() instead Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Link: https://lore.kernel.org/r/20210518045353.611017-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
957 lines
24 KiB
C
957 lines
24 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
*
|
|
* Added support for a Unix98-style ptmx device.
|
|
* -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/tty_flip.h>
|
|
#include <linux/fcntl.h>
|
|
#include <linux/sched/signal.h>
|
|
#include <linux/string.h>
|
|
#include <linux/major.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/init.h>
|
|
#include <linux/device.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/bitops.h>
|
|
#include <linux/devpts_fs.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/poll.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/file.h>
|
|
#include <linux/ioctl.h>
|
|
#include <linux/compat.h>
|
|
#include "tty.h"
|
|
|
|
#undef TTY_DEBUG_HANGUP
|
|
#ifdef TTY_DEBUG_HANGUP
|
|
# define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args)
|
|
#else
|
|
# define tty_debug_hangup(tty, f, args...) do {} while (0)
|
|
#endif
|
|
|
|
#ifdef CONFIG_UNIX98_PTYS
|
|
static struct tty_driver *ptm_driver;
|
|
static struct tty_driver *pts_driver;
|
|
static DEFINE_MUTEX(devpts_mutex);
|
|
#endif
|
|
|
|
static void pty_close(struct tty_struct *tty, struct file *filp)
|
|
{
|
|
if (tty->driver->subtype == PTY_TYPE_MASTER)
|
|
WARN_ON(tty->count > 1);
|
|
else {
|
|
if (tty_io_error(tty))
|
|
return;
|
|
if (tty->count > 2)
|
|
return;
|
|
}
|
|
set_bit(TTY_IO_ERROR, &tty->flags);
|
|
wake_up_interruptible(&tty->read_wait);
|
|
wake_up_interruptible(&tty->write_wait);
|
|
spin_lock_irq(&tty->ctrl.lock);
|
|
tty->ctrl.packet = false;
|
|
spin_unlock_irq(&tty->ctrl.lock);
|
|
/* Review - krefs on tty_link ?? */
|
|
if (!tty->link)
|
|
return;
|
|
set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
|
|
wake_up_interruptible(&tty->link->read_wait);
|
|
wake_up_interruptible(&tty->link->write_wait);
|
|
if (tty->driver->subtype == PTY_TYPE_MASTER) {
|
|
set_bit(TTY_OTHER_CLOSED, &tty->flags);
|
|
#ifdef CONFIG_UNIX98_PTYS
|
|
if (tty->driver == ptm_driver) {
|
|
mutex_lock(&devpts_mutex);
|
|
if (tty->link->driver_data)
|
|
devpts_pty_kill(tty->link->driver_data);
|
|
mutex_unlock(&devpts_mutex);
|
|
}
|
|
#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
|
|
* 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)
|
|
{
|
|
tty_wakeup(tty->link);
|
|
set_bit(TTY_THROTTLED, &tty->flags);
|
|
}
|
|
|
|
/**
|
|
* pty_write - write to a pty
|
|
* @tty: the tty we write from
|
|
* @buf: kernel buffer of data
|
|
* @c: bytes to write
|
|
*
|
|
* Our "hardware" write method. Data is coming from the ldisc which
|
|
* may be in a non sleeping state. We simply throw this at the other
|
|
* end of the link as if we were an IRQ handler receiving stuff for
|
|
* the other side of the pty/tty pair.
|
|
*/
|
|
|
|
static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
|
|
{
|
|
struct tty_struct *to = tty->link;
|
|
unsigned long flags;
|
|
|
|
if (tty->flow.stopped)
|
|
return 0;
|
|
|
|
if (c > 0) {
|
|
spin_lock_irqsave(&to->port->lock, flags);
|
|
/* Stuff the data into the input queue of the other end */
|
|
c = tty_insert_flip_string(to->port, buf, c);
|
|
spin_unlock_irqrestore(&to->port->lock, flags);
|
|
/* And shovel */
|
|
if (c)
|
|
tty_flip_buffer_push(to->port);
|
|
}
|
|
return c;
|
|
}
|
|
|
|
/**
|
|
* pty_write_room - write space
|
|
* @tty: tty we are writing from
|
|
*
|
|
* Report how many bytes the ldisc can send into the queue for
|
|
* the other device.
|
|
*/
|
|
|
|
static unsigned int pty_write_room(struct tty_struct *tty)
|
|
{
|
|
if (tty->flow.stopped)
|
|
return 0;
|
|
return tty_buffer_space_avail(tty->link->port);
|
|
}
|
|
|
|
/* Set the lock flag on a pty */
|
|
static int pty_set_lock(struct tty_struct *tty, int __user *arg)
|
|
{
|
|
int val;
|
|
|
|
if (get_user(val, arg))
|
|
return -EFAULT;
|
|
if (val)
|
|
set_bit(TTY_PTY_LOCK, &tty->flags);
|
|
else
|
|
clear_bit(TTY_PTY_LOCK, &tty->flags);
|
|
return 0;
|
|
}
|
|
|
|
static int pty_get_lock(struct tty_struct *tty, int __user *arg)
|
|
{
|
|
int locked = test_bit(TTY_PTY_LOCK, &tty->flags);
|
|
|
|
return put_user(locked, arg);
|
|
}
|
|
|
|
/* Set the packet mode on a pty */
|
|
static int pty_set_pktmode(struct tty_struct *tty, int __user *arg)
|
|
{
|
|
int pktmode;
|
|
|
|
if (get_user(pktmode, arg))
|
|
return -EFAULT;
|
|
|
|
spin_lock_irq(&tty->ctrl.lock);
|
|
if (pktmode) {
|
|
if (!tty->ctrl.packet) {
|
|
tty->link->ctrl.pktstatus = 0;
|
|
smp_mb();
|
|
tty->ctrl.packet = true;
|
|
}
|
|
} else
|
|
tty->ctrl.packet = false;
|
|
spin_unlock_irq(&tty->ctrl.lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Get the packet mode of a pty */
|
|
static int pty_get_pktmode(struct tty_struct *tty, int __user *arg)
|
|
{
|
|
int pktmode = tty->ctrl.packet;
|
|
|
|
return put_user(pktmode, arg);
|
|
}
|
|
|
|
/* Send a signal to the slave */
|
|
static int pty_signal(struct tty_struct *tty, int sig)
|
|
{
|
|
struct pid *pgrp;
|
|
|
|
if (sig != SIGINT && sig != SIGQUIT && sig != SIGTSTP)
|
|
return -EINVAL;
|
|
|
|
if (tty->link) {
|
|
pgrp = tty_get_pgrp(tty->link);
|
|
if (pgrp)
|
|
kill_pgrp(pgrp, sig, 1);
|
|
put_pid(pgrp);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void pty_flush_buffer(struct tty_struct *tty)
|
|
{
|
|
struct tty_struct *to = tty->link;
|
|
|
|
if (!to)
|
|
return;
|
|
|
|
tty_buffer_flush(to, NULL);
|
|
if (to->ctrl.packet) {
|
|
spin_lock_irq(&tty->ctrl.lock);
|
|
tty->ctrl.pktstatus |= TIOCPKT_FLUSHWRITE;
|
|
wake_up_interruptible(&to->read_wait);
|
|
spin_unlock_irq(&tty->ctrl.lock);
|
|
}
|
|
}
|
|
|
|
static int pty_open(struct tty_struct *tty, struct file *filp)
|
|
{
|
|
if (!tty || !tty->link)
|
|
return -ENODEV;
|
|
|
|
if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
|
|
goto out;
|
|
if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
|
|
goto out;
|
|
if (tty->driver->subtype == PTY_TYPE_SLAVE && tty->link->count != 1)
|
|
goto out;
|
|
|
|
clear_bit(TTY_IO_ERROR, &tty->flags);
|
|
clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
|
|
set_bit(TTY_THROTTLED, &tty->flags);
|
|
return 0;
|
|
|
|
out:
|
|
set_bit(TTY_IO_ERROR, &tty->flags);
|
|
return -EIO;
|
|
}
|
|
|
|
static void pty_set_termios(struct tty_struct *tty,
|
|
struct ktermios *old_termios)
|
|
{
|
|
/* See if packet mode change of state. */
|
|
if (tty->link && tty->link->ctrl.packet) {
|
|
int extproc = (old_termios->c_lflag & EXTPROC) | L_EXTPROC(tty);
|
|
int old_flow = ((old_termios->c_iflag & IXON) &&
|
|
(old_termios->c_cc[VSTOP] == '\023') &&
|
|
(old_termios->c_cc[VSTART] == '\021'));
|
|
int new_flow = (I_IXON(tty) &&
|
|
STOP_CHAR(tty) == '\023' &&
|
|
START_CHAR(tty) == '\021');
|
|
if ((old_flow != new_flow) || extproc) {
|
|
spin_lock_irq(&tty->ctrl.lock);
|
|
if (old_flow != new_flow) {
|
|
tty->ctrl.pktstatus &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
|
|
if (new_flow)
|
|
tty->ctrl.pktstatus |= TIOCPKT_DOSTOP;
|
|
else
|
|
tty->ctrl.pktstatus |= TIOCPKT_NOSTOP;
|
|
}
|
|
if (extproc)
|
|
tty->ctrl.pktstatus |= TIOCPKT_IOCTL;
|
|
spin_unlock_irq(&tty->ctrl.lock);
|
|
wake_up_interruptible(&tty->link->read_wait);
|
|
}
|
|
}
|
|
|
|
tty->termios.c_cflag &= ~(CSIZE | PARENB);
|
|
tty->termios.c_cflag |= (CS8 | CREAD);
|
|
}
|
|
|
|
/**
|
|
* pty_resize - resize event
|
|
* @tty: tty being resized
|
|
* @ws: window size being set.
|
|
*
|
|
* Update the termios variables and send the necessary signals to
|
|
* peform a terminal resize correctly
|
|
*/
|
|
|
|
static int pty_resize(struct tty_struct *tty, struct winsize *ws)
|
|
{
|
|
struct pid *pgrp, *rpgrp;
|
|
struct tty_struct *pty = tty->link;
|
|
|
|
/* For a PTY we need to lock the tty side */
|
|
mutex_lock(&tty->winsize_mutex);
|
|
if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
|
|
goto done;
|
|
|
|
/* Signal the foreground process group of both ptys */
|
|
pgrp = tty_get_pgrp(tty);
|
|
rpgrp = tty_get_pgrp(pty);
|
|
|
|
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->winsize_mutex);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* pty_start - start() handler
|
|
* pty_stop - stop() handler
|
|
* @tty: tty being flow-controlled
|
|
*
|
|
* Propagates the TIOCPKT status to the master pty.
|
|
*
|
|
* NB: only the master pty can be in packet mode so only the slave
|
|
* needs start()/stop() handlers
|
|
*/
|
|
static void pty_start(struct tty_struct *tty)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (tty->link && tty->link->ctrl.packet) {
|
|
spin_lock_irqsave(&tty->ctrl.lock, flags);
|
|
tty->ctrl.pktstatus &= ~TIOCPKT_STOP;
|
|
tty->ctrl.pktstatus |= TIOCPKT_START;
|
|
spin_unlock_irqrestore(&tty->ctrl.lock, flags);
|
|
wake_up_interruptible_poll(&tty->link->read_wait, EPOLLIN);
|
|
}
|
|
}
|
|
|
|
static void pty_stop(struct tty_struct *tty)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (tty->link && tty->link->ctrl.packet) {
|
|
spin_lock_irqsave(&tty->ctrl.lock, flags);
|
|
tty->ctrl.pktstatus &= ~TIOCPKT_START;
|
|
tty->ctrl.pktstatus |= TIOCPKT_STOP;
|
|
spin_unlock_irqrestore(&tty->ctrl.lock, flags);
|
|
wake_up_interruptible_poll(&tty->link->read_wait, EPOLLIN);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* pty_common_install - set up the pty pair
|
|
* @driver: the pty driver
|
|
* @tty: the tty being instantiated
|
|
* @legacy: true if this is BSD style
|
|
*
|
|
* Perform the initial set up for the tty/pty pair. Called from the
|
|
* tty layer when the port is first opened.
|
|
*
|
|
* Locking: the caller must hold the tty_mutex
|
|
*/
|
|
static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
|
|
bool legacy)
|
|
{
|
|
struct tty_struct *o_tty;
|
|
struct tty_port *ports[2];
|
|
int idx = tty->index;
|
|
int retval = -ENOMEM;
|
|
|
|
/* Opening the slave first has always returned -EIO */
|
|
if (driver->subtype != PTY_TYPE_MASTER)
|
|
return -EIO;
|
|
|
|
ports[0] = kmalloc(sizeof **ports, GFP_KERNEL);
|
|
ports[1] = kmalloc(sizeof **ports, GFP_KERNEL);
|
|
if (!ports[0] || !ports[1])
|
|
goto err;
|
|
if (!try_module_get(driver->other->owner)) {
|
|
/* This cannot in fact currently happen */
|
|
goto err;
|
|
}
|
|
o_tty = alloc_tty_struct(driver->other, idx);
|
|
if (!o_tty)
|
|
goto err_put_module;
|
|
|
|
tty_set_lock_subclass(o_tty);
|
|
lockdep_set_subclass(&o_tty->termios_rwsem, TTY_LOCK_SLAVE);
|
|
|
|
if (legacy) {
|
|
/* We always use new tty termios data so we can do this
|
|
the easy way .. */
|
|
tty_init_termios(tty);
|
|
tty_init_termios(o_tty);
|
|
|
|
driver->other->ttys[idx] = o_tty;
|
|
driver->ttys[idx] = tty;
|
|
} else {
|
|
memset(&tty->termios_locked, 0, sizeof(tty->termios_locked));
|
|
tty->termios = driver->init_termios;
|
|
memset(&o_tty->termios_locked, 0, sizeof(tty->termios_locked));
|
|
o_tty->termios = driver->other->init_termios;
|
|
}
|
|
|
|
/*
|
|
* Everything allocated ... set up the o_tty structure.
|
|
*/
|
|
tty_driver_kref_get(driver->other);
|
|
/* Establish the links in both directions */
|
|
tty->link = o_tty;
|
|
o_tty->link = tty;
|
|
tty_port_init(ports[0]);
|
|
tty_port_init(ports[1]);
|
|
tty_buffer_set_limit(ports[0], 8192);
|
|
tty_buffer_set_limit(ports[1], 8192);
|
|
o_tty->port = ports[0];
|
|
tty->port = ports[1];
|
|
o_tty->port->itty = o_tty;
|
|
|
|
tty_buffer_set_lock_subclass(o_tty->port);
|
|
|
|
tty_driver_kref_get(driver);
|
|
tty->count++;
|
|
o_tty->count++;
|
|
return 0;
|
|
|
|
err_put_module:
|
|
module_put(driver->other->owner);
|
|
err:
|
|
kfree(ports[0]);
|
|
kfree(ports[1]);
|
|
return retval;
|
|
}
|
|
|
|
static void pty_cleanup(struct tty_struct *tty)
|
|
{
|
|
tty_port_put(tty->port);
|
|
}
|
|
|
|
/* Traditional BSD devices */
|
|
#ifdef CONFIG_LEGACY_PTYS
|
|
|
|
static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
|
|
{
|
|
return pty_common_install(driver, tty, true);
|
|
}
|
|
|
|
static void pty_remove(struct tty_driver *driver, struct tty_struct *tty)
|
|
{
|
|
struct tty_struct *pair = tty->link;
|
|
|
|
driver->ttys[tty->index] = NULL;
|
|
if (pair)
|
|
pair->driver->ttys[pair->index] = NULL;
|
|
}
|
|
|
|
static int pty_bsd_ioctl(struct tty_struct *tty,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
switch (cmd) {
|
|
case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
|
|
return pty_set_lock(tty, (int __user *) arg);
|
|
case TIOCGPTLCK: /* Get PT Lock status */
|
|
return pty_get_lock(tty, (int __user *)arg);
|
|
case TIOCPKT: /* Set PT packet mode */
|
|
return pty_set_pktmode(tty, (int __user *)arg);
|
|
case TIOCGPKT: /* Get PT packet mode */
|
|
return pty_get_pktmode(tty, (int __user *)arg);
|
|
case TIOCSIG: /* Send signal to other side of pty */
|
|
return pty_signal(tty, (int) arg);
|
|
case TIOCGPTN: /* TTY returns ENOTTY, but glibc expects EINVAL here */
|
|
return -EINVAL;
|
|
}
|
|
return -ENOIOCTLCMD;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static long pty_bsd_compat_ioctl(struct tty_struct *tty,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
/*
|
|
* PTY ioctls don't require any special translation between 32-bit and
|
|
* 64-bit userspace, they are already compatible.
|
|
*/
|
|
return pty_bsd_ioctl(tty, cmd, (unsigned long)compat_ptr(arg));
|
|
}
|
|
#else
|
|
#define pty_bsd_compat_ioctl NULL
|
|
#endif
|
|
|
|
static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
|
|
/*
|
|
* not really modular, but the easiest way to keep compat with existing
|
|
* bootargs behaviour is to continue using module_param here.
|
|
*/
|
|
module_param(legacy_count, int, 0);
|
|
|
|
/*
|
|
* The master side of a pty can do TIOCSPTLCK and thus
|
|
* has pty_bsd_ioctl.
|
|
*/
|
|
static const struct tty_operations master_pty_ops_bsd = {
|
|
.install = pty_install,
|
|
.open = pty_open,
|
|
.close = pty_close,
|
|
.write = pty_write,
|
|
.write_room = pty_write_room,
|
|
.flush_buffer = pty_flush_buffer,
|
|
.unthrottle = pty_unthrottle,
|
|
.ioctl = pty_bsd_ioctl,
|
|
.compat_ioctl = pty_bsd_compat_ioctl,
|
|
.cleanup = pty_cleanup,
|
|
.resize = pty_resize,
|
|
.remove = pty_remove
|
|
};
|
|
|
|
static const struct tty_operations slave_pty_ops_bsd = {
|
|
.install = pty_install,
|
|
.open = pty_open,
|
|
.close = pty_close,
|
|
.write = pty_write,
|
|
.write_room = pty_write_room,
|
|
.flush_buffer = pty_flush_buffer,
|
|
.unthrottle = pty_unthrottle,
|
|
.set_termios = pty_set_termios,
|
|
.cleanup = pty_cleanup,
|
|
.resize = pty_resize,
|
|
.start = pty_start,
|
|
.stop = pty_stop,
|
|
.remove = pty_remove
|
|
};
|
|
|
|
static void __init legacy_pty_init(void)
|
|
{
|
|
struct tty_driver *pty_driver, *pty_slave_driver;
|
|
|
|
if (legacy_count <= 0)
|
|
return;
|
|
|
|
pty_driver = tty_alloc_driver(legacy_count,
|
|
TTY_DRIVER_RESET_TERMIOS |
|
|
TTY_DRIVER_REAL_RAW |
|
|
TTY_DRIVER_DYNAMIC_ALLOC);
|
|
if (IS_ERR(pty_driver))
|
|
panic("Couldn't allocate pty driver");
|
|
|
|
pty_slave_driver = tty_alloc_driver(legacy_count,
|
|
TTY_DRIVER_RESET_TERMIOS |
|
|
TTY_DRIVER_REAL_RAW |
|
|
TTY_DRIVER_DYNAMIC_ALLOC);
|
|
if (IS_ERR(pty_slave_driver))
|
|
panic("Couldn't allocate pty slave driver");
|
|
|
|
pty_driver->driver_name = "pty_master";
|
|
pty_driver->name = "pty";
|
|
pty_driver->major = PTY_MASTER_MAJOR;
|
|
pty_driver->minor_start = 0;
|
|
pty_driver->type = TTY_DRIVER_TYPE_PTY;
|
|
pty_driver->subtype = PTY_TYPE_MASTER;
|
|
pty_driver->init_termios = tty_std_termios;
|
|
pty_driver->init_termios.c_iflag = 0;
|
|
pty_driver->init_termios.c_oflag = 0;
|
|
pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
|
|
pty_driver->init_termios.c_lflag = 0;
|
|
pty_driver->init_termios.c_ispeed = 38400;
|
|
pty_driver->init_termios.c_ospeed = 38400;
|
|
pty_driver->other = pty_slave_driver;
|
|
tty_set_operations(pty_driver, &master_pty_ops_bsd);
|
|
|
|
pty_slave_driver->driver_name = "pty_slave";
|
|
pty_slave_driver->name = "ttyp";
|
|
pty_slave_driver->major = PTY_SLAVE_MAJOR;
|
|
pty_slave_driver->minor_start = 0;
|
|
pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
|
|
pty_slave_driver->subtype = PTY_TYPE_SLAVE;
|
|
pty_slave_driver->init_termios = tty_std_termios;
|
|
pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
|
|
pty_slave_driver->init_termios.c_ispeed = 38400;
|
|
pty_slave_driver->init_termios.c_ospeed = 38400;
|
|
pty_slave_driver->other = pty_driver;
|
|
tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
|
|
|
|
if (tty_register_driver(pty_driver))
|
|
panic("Couldn't register pty driver");
|
|
if (tty_register_driver(pty_slave_driver))
|
|
panic("Couldn't register pty slave driver");
|
|
}
|
|
#else
|
|
static inline void legacy_pty_init(void) { }
|
|
#endif
|
|
|
|
/* Unix98 devices */
|
|
#ifdef CONFIG_UNIX98_PTYS
|
|
static struct cdev ptmx_cdev;
|
|
|
|
/**
|
|
* ptm_open_peer - open the peer of a pty
|
|
* @master: the open struct file of the ptmx device node
|
|
* @tty: the master of the pty being opened
|
|
* @flags: the flags for open
|
|
*
|
|
* Provide a race free way for userspace to open the slave end of a pty
|
|
* (where they have the master fd and cannot access or trust the mount
|
|
* namespace /dev/pts was mounted inside).
|
|
*/
|
|
int ptm_open_peer(struct file *master, struct tty_struct *tty, int flags)
|
|
{
|
|
int fd;
|
|
struct file *filp;
|
|
int retval = -EINVAL;
|
|
struct path path;
|
|
|
|
if (tty->driver != ptm_driver)
|
|
return -EIO;
|
|
|
|
fd = get_unused_fd_flags(flags);
|
|
if (fd < 0) {
|
|
retval = fd;
|
|
goto err;
|
|
}
|
|
|
|
/* Compute the slave's path */
|
|
path.mnt = devpts_mntget(master, tty->driver_data);
|
|
if (IS_ERR(path.mnt)) {
|
|
retval = PTR_ERR(path.mnt);
|
|
goto err_put;
|
|
}
|
|
path.dentry = tty->link->driver_data;
|
|
|
|
filp = dentry_open(&path, flags, current_cred());
|
|
mntput(path.mnt);
|
|
if (IS_ERR(filp)) {
|
|
retval = PTR_ERR(filp);
|
|
goto err_put;
|
|
}
|
|
|
|
fd_install(fd, filp);
|
|
return fd;
|
|
|
|
err_put:
|
|
put_unused_fd(fd);
|
|
err:
|
|
return retval;
|
|
}
|
|
|
|
static int pty_unix98_ioctl(struct tty_struct *tty,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
switch (cmd) {
|
|
case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
|
|
return pty_set_lock(tty, (int __user *)arg);
|
|
case TIOCGPTLCK: /* Get PT Lock status */
|
|
return pty_get_lock(tty, (int __user *)arg);
|
|
case TIOCPKT: /* Set PT packet mode */
|
|
return pty_set_pktmode(tty, (int __user *)arg);
|
|
case TIOCGPKT: /* Get PT packet mode */
|
|
return pty_get_pktmode(tty, (int __user *)arg);
|
|
case TIOCGPTN: /* Get PT Number */
|
|
return put_user(tty->index, (unsigned int __user *)arg);
|
|
case TIOCSIG: /* Send signal to other side of pty */
|
|
return pty_signal(tty, (int) arg);
|
|
}
|
|
|
|
return -ENOIOCTLCMD;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static long pty_unix98_compat_ioctl(struct tty_struct *tty,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
/*
|
|
* PTY ioctls don't require any special translation between 32-bit and
|
|
* 64-bit userspace, they are already compatible.
|
|
*/
|
|
return pty_unix98_ioctl(tty, cmd,
|
|
cmd == TIOCSIG ? arg : (unsigned long)compat_ptr(arg));
|
|
}
|
|
#else
|
|
#define pty_unix98_compat_ioctl NULL
|
|
#endif
|
|
|
|
/**
|
|
* ptm_unix98_lookup - find a pty master
|
|
* @driver: ptm driver
|
|
* @file: unused
|
|
* @idx: tty index
|
|
*
|
|
* Look up a pty master device. Called under the tty_mutex for now.
|
|
* This provides our locking.
|
|
*/
|
|
|
|
static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
|
|
struct file *file, int idx)
|
|
{
|
|
/* Master must be open via /dev/ptmx */
|
|
return ERR_PTR(-EIO);
|
|
}
|
|
|
|
/**
|
|
* pts_unix98_lookup - find a pty slave
|
|
* @driver: pts driver
|
|
* @file: file pointer to tty
|
|
* @idx: tty index
|
|
*
|
|
* Look up a pty master device. Called under the tty_mutex for now.
|
|
* This provides our locking for the tty pointer.
|
|
*/
|
|
|
|
static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
|
|
struct file *file, int idx)
|
|
{
|
|
struct tty_struct *tty;
|
|
|
|
mutex_lock(&devpts_mutex);
|
|
tty = devpts_get_priv(file->f_path.dentry);
|
|
mutex_unlock(&devpts_mutex);
|
|
/* Master must be open before slave */
|
|
if (!tty)
|
|
return ERR_PTR(-EIO);
|
|
return tty;
|
|
}
|
|
|
|
static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
|
|
{
|
|
return pty_common_install(driver, tty, false);
|
|
}
|
|
|
|
/* this is called once with whichever end is closed last */
|
|
static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
|
|
{
|
|
struct pts_fs_info *fsi;
|
|
|
|
if (tty->driver->subtype == PTY_TYPE_MASTER)
|
|
fsi = tty->driver_data;
|
|
else
|
|
fsi = tty->link->driver_data;
|
|
|
|
if (fsi) {
|
|
devpts_kill_index(fsi, tty->index);
|
|
devpts_release(fsi);
|
|
}
|
|
}
|
|
|
|
static void pty_show_fdinfo(struct tty_struct *tty, struct seq_file *m)
|
|
{
|
|
seq_printf(m, "tty-index:\t%d\n", tty->index);
|
|
}
|
|
|
|
static const struct tty_operations ptm_unix98_ops = {
|
|
.lookup = ptm_unix98_lookup,
|
|
.install = pty_unix98_install,
|
|
.remove = pty_unix98_remove,
|
|
.open = pty_open,
|
|
.close = pty_close,
|
|
.write = pty_write,
|
|
.write_room = pty_write_room,
|
|
.flush_buffer = pty_flush_buffer,
|
|
.unthrottle = pty_unthrottle,
|
|
.ioctl = pty_unix98_ioctl,
|
|
.compat_ioctl = pty_unix98_compat_ioctl,
|
|
.resize = pty_resize,
|
|
.cleanup = pty_cleanup,
|
|
.show_fdinfo = pty_show_fdinfo,
|
|
};
|
|
|
|
static const struct tty_operations pty_unix98_ops = {
|
|
.lookup = pts_unix98_lookup,
|
|
.install = pty_unix98_install,
|
|
.remove = pty_unix98_remove,
|
|
.open = pty_open,
|
|
.close = pty_close,
|
|
.write = pty_write,
|
|
.write_room = pty_write_room,
|
|
.flush_buffer = pty_flush_buffer,
|
|
.unthrottle = pty_unthrottle,
|
|
.set_termios = pty_set_termios,
|
|
.start = pty_start,
|
|
.stop = pty_stop,
|
|
.cleanup = pty_cleanup,
|
|
};
|
|
|
|
/**
|
|
* ptmx_open - open a unix 98 pty master
|
|
* @inode: inode of device file
|
|
* @filp: file pointer to tty
|
|
*
|
|
* Allocate a unix98 pty master device from the ptmx driver.
|
|
*
|
|
* Locking: tty_mutex protects the init_dev work. tty->count should
|
|
* protect the rest.
|
|
* allocated_ptys_lock handles the list of free pty numbers
|
|
*/
|
|
|
|
static int ptmx_open(struct inode *inode, struct file *filp)
|
|
{
|
|
struct pts_fs_info *fsi;
|
|
struct tty_struct *tty;
|
|
struct dentry *dentry;
|
|
int retval;
|
|
int index;
|
|
|
|
nonseekable_open(inode, filp);
|
|
|
|
/* We refuse fsnotify events on ptmx, since it's a shared resource */
|
|
filp->f_mode |= FMODE_NONOTIFY;
|
|
|
|
retval = tty_alloc_file(filp);
|
|
if (retval)
|
|
return retval;
|
|
|
|
fsi = devpts_acquire(filp);
|
|
if (IS_ERR(fsi)) {
|
|
retval = PTR_ERR(fsi);
|
|
goto out_free_file;
|
|
}
|
|
|
|
/* find a device that is not in use. */
|
|
mutex_lock(&devpts_mutex);
|
|
index = devpts_new_index(fsi);
|
|
mutex_unlock(&devpts_mutex);
|
|
|
|
retval = index;
|
|
if (index < 0)
|
|
goto out_put_fsi;
|
|
|
|
|
|
mutex_lock(&tty_mutex);
|
|
tty = tty_init_dev(ptm_driver, index);
|
|
/* The tty returned here is locked so we can safely
|
|
drop the mutex */
|
|
mutex_unlock(&tty_mutex);
|
|
|
|
retval = PTR_ERR(tty);
|
|
if (IS_ERR(tty))
|
|
goto out;
|
|
|
|
/*
|
|
* From here on out, the tty is "live", and the index and
|
|
* fsi will be killed/put by the tty_release()
|
|
*/
|
|
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
|
|
tty->driver_data = fsi;
|
|
|
|
tty_add_file(tty, filp);
|
|
|
|
dentry = devpts_pty_new(fsi, index, tty->link);
|
|
if (IS_ERR(dentry)) {
|
|
retval = PTR_ERR(dentry);
|
|
goto err_release;
|
|
}
|
|
tty->link->driver_data = dentry;
|
|
|
|
retval = ptm_driver->ops->open(tty, filp);
|
|
if (retval)
|
|
goto err_release;
|
|
|
|
tty_debug_hangup(tty, "opening (count=%d)\n", tty->count);
|
|
|
|
tty_unlock(tty);
|
|
return 0;
|
|
err_release:
|
|
tty_unlock(tty);
|
|
// This will also put-ref the fsi
|
|
tty_release(inode, filp);
|
|
return retval;
|
|
out:
|
|
devpts_kill_index(fsi, index);
|
|
out_put_fsi:
|
|
devpts_release(fsi);
|
|
out_free_file:
|
|
tty_free_file(filp);
|
|
return retval;
|
|
}
|
|
|
|
static struct file_operations ptmx_fops __ro_after_init;
|
|
|
|
static void __init unix98_pty_init(void)
|
|
{
|
|
ptm_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
|
|
TTY_DRIVER_RESET_TERMIOS |
|
|
TTY_DRIVER_REAL_RAW |
|
|
TTY_DRIVER_DYNAMIC_DEV |
|
|
TTY_DRIVER_DEVPTS_MEM |
|
|
TTY_DRIVER_DYNAMIC_ALLOC);
|
|
if (IS_ERR(ptm_driver))
|
|
panic("Couldn't allocate Unix98 ptm driver");
|
|
pts_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
|
|
TTY_DRIVER_RESET_TERMIOS |
|
|
TTY_DRIVER_REAL_RAW |
|
|
TTY_DRIVER_DYNAMIC_DEV |
|
|
TTY_DRIVER_DEVPTS_MEM |
|
|
TTY_DRIVER_DYNAMIC_ALLOC);
|
|
if (IS_ERR(pts_driver))
|
|
panic("Couldn't allocate Unix98 pts driver");
|
|
|
|
ptm_driver->driver_name = "pty_master";
|
|
ptm_driver->name = "ptm";
|
|
ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
|
|
ptm_driver->minor_start = 0;
|
|
ptm_driver->type = TTY_DRIVER_TYPE_PTY;
|
|
ptm_driver->subtype = PTY_TYPE_MASTER;
|
|
ptm_driver->init_termios = tty_std_termios;
|
|
ptm_driver->init_termios.c_iflag = 0;
|
|
ptm_driver->init_termios.c_oflag = 0;
|
|
ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
|
|
ptm_driver->init_termios.c_lflag = 0;
|
|
ptm_driver->init_termios.c_ispeed = 38400;
|
|
ptm_driver->init_termios.c_ospeed = 38400;
|
|
ptm_driver->other = pts_driver;
|
|
tty_set_operations(ptm_driver, &ptm_unix98_ops);
|
|
|
|
pts_driver->driver_name = "pty_slave";
|
|
pts_driver->name = "pts";
|
|
pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
|
|
pts_driver->minor_start = 0;
|
|
pts_driver->type = TTY_DRIVER_TYPE_PTY;
|
|
pts_driver->subtype = PTY_TYPE_SLAVE;
|
|
pts_driver->init_termios = tty_std_termios;
|
|
pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
|
|
pts_driver->init_termios.c_ispeed = 38400;
|
|
pts_driver->init_termios.c_ospeed = 38400;
|
|
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");
|
|
|
|
/* Now create the /dev/ptmx special device */
|
|
tty_default_fops(&ptmx_fops);
|
|
ptmx_fops.open = ptmx_open;
|
|
|
|
cdev_init(&ptmx_cdev, &ptmx_fops);
|
|
if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
|
|
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
|
|
panic("Couldn't register /dev/ptmx driver");
|
|
device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
|
|
}
|
|
|
|
#else
|
|
static inline void unix98_pty_init(void) { }
|
|
#endif
|
|
|
|
static int __init pty_init(void)
|
|
{
|
|
legacy_pty_init();
|
|
unix98_pty_init();
|
|
return 0;
|
|
}
|
|
device_initcall(pty_init);
|