static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
{
struct tty_struct *o_tty;
int idx = tty->index;
int retval;
o_tty = alloc_tty_struct();
if (!o_tty)
return -ENOMEM;
if (!try_module_get(driver->other->owner)) {
/* This cannot in fact currently happen */
retval = -ENOMEM;
goto err_free_tty;
}
initialize_tty_struct(o_tty, driver->other, idx);
/* We always use new tty termios data so we can do this
the easy way .. */
retval = tty_init_termios(tty);
if (retval)
goto err_deinit_tty;
retval = tty_init_termios(o_tty);
if (retval)
goto err_free_termios;
/*
* Everything allocated ... set up the o_tty structure.
*/
driver->other->ttys[idx] = o_tty;
tty_driver_kref_get(driver->other);
if (driver->subtype == PTY_TYPE_MASTER)
o_tty->count++;
/* Establish the links in both directions */
tty->link = o_tty;
o_tty->link = tty;
tty_driver_kref_get(driver);
tty->count++;
driver->ttys[idx] = tty;
return 0;
err_free_termios:
tty_free_termios(tty);
err_deinit_tty:
deinitialize_tty_struct(o_tty);
module_put(o_tty->driver->owner);
err_free_tty:
free_tty_struct(o_tty);
return retval;
}
static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
{
struct tty_struct *o_tty;
int idx = tty->index;
o_tty = alloc_tty_struct();
if (!o_tty)
return -ENOMEM;
if (!try_module_get(driver->other->owner)) {
/* This cannot in fact currently happen */
goto err_free_tty;
}
initialize_tty_struct(o_tty, driver->other, idx);
tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
if (tty->termios == NULL)
goto err_free_mem;
*tty->termios = driver->init_termios;
tty->termios_locked = tty->termios + 1;
o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
if (o_tty->termios == NULL)
goto err_free_mem;
*o_tty->termios = driver->other->init_termios;
o_tty->termios_locked = o_tty->termios + 1;
tty_driver_kref_get(driver->other);
if (driver->subtype == PTY_TYPE_MASTER)
o_tty->count++;
/* Establish the links in both directions */
tty->link = o_tty;
o_tty->link = tty;
/*
* All structures have been allocated, so now we install them.
* Failures after this point use release_tty to clean up, so
* there's no need to null out the local pointers.
*/
tty_driver_kref_get(driver);
tty->count++;
return 0;
err_free_mem:
deinitialize_tty_struct(o_tty);
kfree(o_tty->termios);
kfree(tty->termios);
module_put(o_tty->driver->owner);
err_free_tty:
free_tty_struct(o_tty);
return -ENOMEM;
}
/**
* pty_common_install - set up the pty pair
* @driver: the pty driver
* @tty: the tty being instantiated
* @bool: 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;
o_tty = alloc_tty_struct();
if (!o_tty)
goto err;
ports[0] = kmalloc(sizeof **ports, GFP_KERNEL);
ports[1] = kmalloc(sizeof **ports, GFP_KERNEL);
if (!ports[0] || !ports[1])
goto err_free_tty;
if (!try_module_get(driver->other->owner)) {
/* This cannot in fact currently happen */
goto err_free_tty;
}
initialize_tty_struct(o_tty, driver->other, idx);
if (legacy) {
/* We always use new tty termios data so we can do this
the easy way .. */
retval = tty_init_termios(tty);
if (retval)
goto err_deinit_tty;
retval = tty_init_termios(o_tty);
if (retval)
goto err_free_termios;
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);
if (driver->subtype == PTY_TYPE_MASTER)
o_tty->count++;
/* Establish the links in both directions */
tty->link = o_tty;
o_tty->link = tty;
tty_port_init(ports[0]);
tty_port_init(ports[1]);
o_tty->port = ports[0];
tty->port = ports[1];
o_tty->port->itty = o_tty;
tty_driver_kref_get(driver);
tty->count++;
return 0;
err_free_termios:
if (legacy)
tty_free_termios(tty);
err_deinit_tty:
deinitialize_tty_struct(o_tty);
module_put(o_tty->driver->owner);
err_free_tty:
kfree(ports[0]);
kfree(ports[1]);
free_tty_struct(o_tty);
err:
return retval;
}
/*
* This is so ripe with races that you should *really* not touch this
* unless you know exactly what you are doing. All the changes have to be
* made atomically, or there may be incorrect pointers all over the place.
*/
static int init_dev(int dev)
{
struct tty_struct *tty, *o_tty;
struct termios *tp, *o_tp, *ltp, *o_ltp;
int retval;
int o_dev;
o_dev = PTY_OTHER(dev);
tty = o_tty = NULL;
tp = o_tp = NULL;
ltp = o_ltp = NULL;
repeat:
retval = -EAGAIN;
if (IS_A_PTY_MASTER(dev) && tty_table[dev] && tty_table[dev]->count)
goto end_init;
retval = -ENOMEM;
if (!tty_table[dev] && !tty) {
if (!(tty = (struct tty_struct*) get_free_page(GFP_KERNEL)))
goto end_init;
initialize_tty_struct(dev, tty);
goto repeat;
}
if (!tty_termios[dev] && !tp) {
tp = (struct termios *) kmalloc(sizeof(struct termios),
GFP_KERNEL);
if (!tp)
goto end_init;
initialize_termios(dev, tp);
goto repeat;
}
if (!termios_locked[dev] && !ltp) {
ltp = (struct termios *) kmalloc(sizeof(struct termios),
GFP_KERNEL);
if (!ltp)
goto end_init;
memset(ltp, 0, sizeof(struct termios));
goto repeat;
}
if (IS_A_PTY(dev)) {
if (!tty_table[o_dev] && !o_tty) {
o_tty = (struct tty_struct *)
get_free_page(GFP_KERNEL);
if (!o_tty)
goto end_init;
initialize_tty_struct(o_dev, o_tty);
goto repeat;
}
if (!tty_termios[o_dev] && !o_tp) {
o_tp = (struct termios *)
kmalloc(sizeof(struct termios), GFP_KERNEL);
if (!o_tp)
goto end_init;
initialize_termios(o_dev, o_tp);
goto repeat;
}
if (!termios_locked[o_dev] && !o_ltp) {
o_ltp = (struct termios *)
kmalloc(sizeof(struct termios), GFP_KERNEL);
if (!o_ltp)
goto end_init;
memset(o_ltp, 0, sizeof(struct termios));
goto repeat;
}
}
/* Now we have allocated all the structures: update all the pointers.. */
if (!tty_termios[dev]) {
tty_termios[dev] = tp;
tp = NULL;
}
if (!tty_table[dev]) {
tty->termios = tty_termios[dev];
tty_table[dev] = tty;
tty = NULL;
}
if (!termios_locked[dev]) {
termios_locked[dev] = ltp;
ltp = NULL;
}
if (IS_A_PTY(dev)) {
if (!tty_termios[o_dev]) {
tty_termios[o_dev] = o_tp;
o_tp = NULL;
}
if (!termios_locked[o_dev]) {
termios_locked[o_dev] = o_ltp;
o_ltp = NULL;
}
if (!tty_table[o_dev]) {
o_tty->termios = tty_termios[o_dev];
tty_table[o_dev] = o_tty;
o_tty = NULL;
}
tty_table[dev]->link = tty_table[o_dev];
tty_table[o_dev]->link = tty_table[dev];
}
tty_table[dev]->count++;
if (IS_A_PTY_MASTER(dev))
tty_table[o_dev]->count++;
retval = 0;
end_init:
if (tty)
free_page((unsigned long) tty);
if (o_tty)
free_page((unsigned long) o_tty);
if (tp)
kfree_s(tp, sizeof(struct termios));
if (o_tp)
kfree_s(o_tp, sizeof(struct termios));
if (ltp)
kfree_s(ltp, sizeof(struct termios));
if (o_ltp)
kfree_s(o_ltp, sizeof(struct termios));
return retval;
}
