static int normal_select(struct tty_struct * tty, struct inode * inode,
struct file * file, int sel_type, select_table *wait)
{
switch (sel_type) {
case SEL_IN:
if (input_available_p(tty))
return 1;
/* fall through */
case SEL_EX:
if (tty->packet && tty->link->ctrl_status)
return 1;
if (tty->flags & (1 << TTY_SLAVE_CLOSED))
return 1;
if (tty_hung_up_p(file))
return 1;
select_wait(&tty->secondary.proc_list, wait);
return 0;
case SEL_OUT:
if (LEFT(&tty->write_q) > WAKEUP_CHARS)
return 1;
select_wait(&tty->write_q.proc_list, wait);
return 0;
}
return 0;
}
static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
poll_table *wait)
{
unsigned int mask = 0;
poll_wait(file, &tty->read_wait, wait);
poll_wait(file, &tty->write_wait, wait);
if (input_available_p(tty, TIME_CHAR(tty) ? 0 : MIN_CHAR(tty)))
mask |= POLLIN | POLLRDNORM;
if (tty->packet && tty->link->ctrl_status)
mask |= POLLPRI | POLLIN | POLLRDNORM;
if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
mask |= POLLHUP;
if (tty_hung_up_p(file))
mask |= POLLHUP;
if (!(mask & (POLLHUP | POLLIN | POLLRDNORM))) {
if (MIN_CHAR(tty) && !TIME_CHAR(tty))
tty->minimum_to_wake = MIN_CHAR(tty);
else
tty->minimum_to_wake = 1;
}
if (tty->ops->write && !tty_is_writelocked(tty) &&
tty_chars_in_buffer(tty) < WAKEUP_CHARS &&
tty_write_room(tty) > 0)
mask |= POLLOUT | POLLWRNORM;
return mask;
}
static int normal_select(struct tty_struct * tty, struct inode * inode,
struct file * file, int sel_type, select_table *wait)
{
switch (sel_type) {
case SEL_IN:
if (input_available_p(tty, TIME_CHAR(tty) ? 0 :
MIN_CHAR(tty)))
return 1;
/* fall through */
case SEL_EX:
if (tty->packet && tty->link->ctrl_status)
return 1;
if (tty->flags & (1 << TTY_OTHER_CLOSED))
return 1;
if (tty_hung_up_p(file))
return 1;
if (!waitqueue_active(&tty->read_wait)) {
if (MIN_CHAR(tty) && !TIME_CHAR(tty))
tty->minimum_to_wake = MIN_CHAR(tty);
else
tty->minimum_to_wake = 1;
}
select_wait(&tty->read_wait, wait);
return 0;
case SEL_OUT:
if (tty->driver.chars_in_buffer(tty) < WAKEUP_CHARS)
return 1;
select_wait(&tty->write_wait, wait);
return 0;
}
return 0;
}
/* When the subprocess has generated some output, this reads as much as it
can into s->buf at s->buf_tail.
*/
static void
drain_input (state *s)
{
XtAppContext app = XtDisplayToApplicationContext (s->dpy);
if (! s->pipe) return;
/* if (! s->input_available_p) return; */
/* s->input_available_p = False; */
if (! input_available_p (fileno (s->pipe)))
return;
if (s->buf_tail < sizeof(s->buf) - 2)
{
int target = sizeof(s->buf) - s->buf_tail - 2;
int n;
n = read (fileno (s->pipe),
(void *) (s->buf + s->buf_tail),
target);
if (n > 0)
{
s->buf_tail += n;
s->buf[s->buf_tail] = 0;
}
else
{
XtRemoveInput (s->pipe_id);
s->pipe_id = 0;
pclose (s->pipe);
s->pipe = 0;
/* If the process didn't print a terminating newline, add one. */
if (s->buf_tail > 1 &&
s->buf[s->buf_tail-1] != '\n')
{
s->buf[s->buf_tail++] = '\n';
s->buf[s->buf_tail] = 0;
}
/* Then add one more, to make sure there's a sentence break at EOF.
*/
s->buf[s->buf_tail++] = '\n';
s->buf[s->buf_tail] = 0;
/* Set up a timer to re-launch the subproc in a bit. */
if (s->timer_id) abort();
s->timer_id = XtAppAddTimeOut (app, s->subproc_relaunch_delay,
relaunch_generator_timer,
(XtPointer) s);
}
}
}
static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
unsigned char __user *buf, size_t nr)
{
unsigned char __user *b = buf;
DECLARE_WAITQUEUE(wait, current);
int c;
int minimum, time;
ssize_t retval = 0;
ssize_t size;
long timeout;
unsigned long flags;
int packet;
do_it_again:
BUG_ON(!tty->read_buf);
c = job_control(tty, file);
if (c < 0)
return c;
minimum = time = 0;
timeout = MAX_SCHEDULE_TIMEOUT;
if (!tty->icanon) {
time = (HZ / 10) * TIME_CHAR(tty);
minimum = MIN_CHAR(tty);
if (minimum) {
if (time)
tty->minimum_to_wake = 1;
else if (!waitqueue_active(&tty->read_wait) ||
(tty->minimum_to_wake > minimum))
tty->minimum_to_wake = minimum;
} else {
timeout = 0;
if (time) {
timeout = time;
time = 0;
}
tty->minimum_to_wake = minimum = 1;
}
}
if (file->f_flags & O_NONBLOCK) {
if (!mutex_trylock(&tty->atomic_read_lock))
return -EAGAIN;
} else {
if (mutex_lock_interruptible(&tty->atomic_read_lock))
return -ERESTARTSYS;
}
packet = tty->packet;
add_wait_queue(&tty->read_wait, &wait);
while (nr) {
if (packet && tty->link->ctrl_status) {
unsigned char cs;
if (b != buf)
break;
spin_lock_irqsave(&tty->link->ctrl_lock, flags);
cs = tty->link->ctrl_status;
tty->link->ctrl_status = 0;
spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
if (tty_put_user(tty, cs, b++)) {
retval = -EFAULT;
b--;
break;
}
nr--;
break;
}
set_current_state(TASK_INTERRUPTIBLE);
if (((minimum - (b - buf)) < tty->minimum_to_wake) &&
((minimum - (b - buf)) >= 1))
tty->minimum_to_wake = (minimum - (b - buf));
if (!input_available_p(tty, 0)) {
if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
retval = -EIO;
break;
}
if (tty_hung_up_p(file))
break;
if (!timeout)
break;
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
n_tty_set_room(tty);
timeout = schedule_timeout(timeout);
BUG_ON(!tty->read_buf);
continue;
}
__set_current_state(TASK_RUNNING);
if (packet && b == buf) {
if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
retval = -EFAULT;
b--;
break;
}
nr--;
}
if (tty->icanon && !L_EXTPROC(tty)) {
while (nr && tty->read_cnt) {
int eol;
eol = test_and_clear_bit(tty->read_tail,
tty->read_flags);
c = tty->read_buf[tty->read_tail];
spin_lock_irqsave(&tty->read_lock, flags);
tty->read_tail = ((tty->read_tail+1) &
(N_TTY_BUF_SIZE-1));
tty->read_cnt--;
if (eol) {
if (--tty->canon_data < 0)
tty->canon_data = 0;
}
spin_unlock_irqrestore(&tty->read_lock, flags);
if (!eol || (c != __DISABLED_CHAR)) {
if (tty_put_user(tty, c, b++)) {
retval = -EFAULT;
b--;
break;
}
nr--;
}
if (eol) {
tty_audit_push(tty);
break;
}
}
if (retval)
break;
} else {
int uncopied;
uncopied = copy_from_read_buf(tty, &b, &nr);
uncopied += copy_from_read_buf(tty, &b, &nr);
if (uncopied) {
retval = -EFAULT;
break;
}
}
if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) {
n_tty_set_room(tty);
check_unthrottle(tty);
}
if (b - buf >= minimum)
break;
if (time)
timeout = time;
}
mutex_unlock(&tty->atomic_read_lock);
remove_wait_queue(&tty->read_wait, &wait);
if (!waitqueue_active(&tty->read_wait))
tty->minimum_to_wake = minimum;
__set_current_state(TASK_RUNNING);
size = b - buf;
if (size) {
retval = size;
if (nr)
clear_bit(TTY_PUSH, &tty->flags);
} else if (test_and_clear_bit(TTY_PUSH, &tty->flags))
goto do_it_again;
n_tty_set_room(tty);
return retval;
}
static int read_chan(struct tty_struct *tty, struct file *file,
unsigned char *buf, unsigned int nr)
{
struct wait_queue wait = { current, NULL };
int c;
unsigned char *b = buf;
int minimum, time;
int retval = 0;
int size;
do_it_again:
if (!tty->read_buf) {
printk("n_tty_read_chan: called with read_buf == NULL?!?\n");
return -EIO;
}
/* Job control check -- must be done at start and after
every sleep (POSIX.1 7.1.1.4). */
/* NOTE: not yet done after every sleep pending a thorough
check of the logic of this change. -- jlc */
/* don't stop on /dev/console */
if (file->f_inode->i_rdev != CONSOLE_DEV &&
current->tty == tty) {
if (tty->pgrp <= 0)
printk("read_chan: tty->pgrp <= 0!\n");
else if (current->pgrp != tty->pgrp) {
if (is_ignored(SIGTTIN) ||
is_orphaned_pgrp(current->pgrp))
return -EIO;
kill_pg(current->pgrp, SIGTTIN, 1);
return -ERESTARTSYS;
}
}
if (L_ICANON(tty)) {
minimum = time = 0;
current->timeout = (unsigned long) -1;
} else {
time = (HZ / 10) * TIME_CHAR(tty);
minimum = MIN_CHAR(tty);
if (minimum) {
current->timeout = (unsigned long) -1;
if (time)
tty->minimum_to_wake = 1;
else if (!waitqueue_active(&tty->read_wait) ||
(tty->minimum_to_wake > minimum))
tty->minimum_to_wake = minimum;
} else {
if (time) {
current->timeout = time + jiffies;
time = 0;
} else
current->timeout = 0;
tty->minimum_to_wake = minimum = 1;
}
}
add_wait_queue(&tty->read_wait, &wait);
while (1) {
/* First test for status change. */
if (tty->packet && tty->link->ctrl_status) {
if (b != buf)
break;
put_user(tty->link->ctrl_status, b++);
tty->link->ctrl_status = 0;
break;
}
/* This statement must be first before checking for input
so that any interrupt will set the state back to
TASK_RUNNING. */
current->state = TASK_INTERRUPTIBLE;
if (((minimum - (b - buf)) < tty->minimum_to_wake) &&
((minimum - (b - buf)) >= 1))
tty->minimum_to_wake = (minimum - (b - buf));
if (!input_available_p(tty, 0)) {
if (tty->flags & (1 << TTY_OTHER_CLOSED)) {
retval = -EIO;
break;
}
if (tty_hung_up_p(file))
break;
if (!current->timeout)
break;
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
if (current->signal & ~current->blocked) {
retval = -ERESTARTSYS;
break;
}
schedule();
continue;
}
current->state = TASK_RUNNING;
/* Deal with packet mode. */
if (tty->packet && b == buf) {
put_user(TIOCPKT_DATA, b++);
nr--;
}
if (L_ICANON(tty)) {
while (1) {
int eol;
disable_bh(TQUEUE_BH);
if (!tty->read_cnt) {
enable_bh(TQUEUE_BH);
break;
}
eol = clear_bit(tty->read_tail,
&tty->read_flags);
c = tty->read_buf[tty->read_tail];
tty->read_tail = ((tty->read_tail+1) &
(N_TTY_BUF_SIZE-1));
tty->read_cnt--;
enable_bh(TQUEUE_BH);
if (!eol) {
put_user(c, b++);
if (--nr)
continue;
break;
}
if (--tty->canon_data < 0) {
tty->canon_data = 0;
}
if (c != __DISABLED_CHAR) {
put_user(c, b++);
nr--;
}
break;
}
} else {
disable_bh(TQUEUE_BH);
copy_from_read_buf(tty, &b, &nr);
copy_from_read_buf(tty, &b, &nr);
enable_bh(TQUEUE_BH);
}
/* If there is enough space in the read buffer now, let the
low-level driver know. */
if (tty->driver.unthrottle &&
(tty->read_cnt <= TTY_THRESHOLD_UNTHROTTLE)
&& clear_bit(TTY_THROTTLED, &tty->flags))
tty->driver.unthrottle(tty);
if (b - buf >= minimum || !nr)
break;
if (time)
current->timeout = time + jiffies;
}
remove_wait_queue(&tty->read_wait, &wait);
if (!waitqueue_active(&tty->read_wait))
tty->minimum_to_wake = minimum;
current->state = TASK_RUNNING;
current->timeout = 0;
size = b - buf;
if (size && nr)
clear_bit(TTY_PUSH, &tty->flags);
if (!size && clear_bit(TTY_PUSH, &tty->flags))
goto do_it_again;
if (!size && !retval)
clear_bit(TTY_PUSH, &tty->flags);
return (size ? size : retval);
}
static ssize_t read_chan(struct tty_struct *tty, struct file *file,
unsigned char *buf, size_t nr)
{
unsigned char *b = buf;
struct wait_queue wait = { current, NULL };
int c;
int minimum, time;
ssize_t retval = 0;
ssize_t size;
long timeout;
do_it_again:
if (!tty->read_buf) {
printk("n_tty_read_chan: called with read_buf == NULL?!?\n");
return -EIO;
}
/* Job control check -- must be done at start and after
every sleep (POSIX.1 7.1.1.4). */
/* NOTE: not yet done after every sleep pending a thorough
check of the logic of this change. -- jlc */
/* don't stop on /dev/console */
if (file->f_dentry->d_inode->i_rdev != CONSOLE_DEV &&
file->f_dentry->d_inode->i_rdev != SYSCONS_DEV &&
current->tty == tty) {
if (tty->pgrp <= 0)
printk("read_chan: tty->pgrp <= 0!\n");
else if (current->pgrp != tty->pgrp) {
if (is_ignored(SIGTTIN) ||
is_orphaned_pgrp(current->pgrp))
return -EIO;
kill_pg(current->pgrp, SIGTTIN, 1);
return -ERESTARTSYS;
}
}
minimum = time = 0;
timeout = MAX_SCHEDULE_TIMEOUT;
if (!tty->icanon) {
time = (HZ / 10) * TIME_CHAR(tty);
minimum = MIN_CHAR(tty);
if (minimum) {
if (time)
tty->minimum_to_wake = 1;
else if (!waitqueue_active(&tty->read_wait) ||
(tty->minimum_to_wake > minimum))
tty->minimum_to_wake = minimum;
} else {
timeout = 0;
if (time) {
timeout = time;
time = 0;
}
tty->minimum_to_wake = minimum = 1;
}
}
if (file->f_flags & O_NONBLOCK) {
if (down_trylock(&tty->atomic_read))
return -EAGAIN;
}
else {
if (down_interruptible(&tty->atomic_read))
return -ERESTARTSYS;
}
add_wait_queue(&tty->read_wait, &wait);
set_bit(TTY_DONT_FLIP, &tty->flags);
while (nr) {
/* First test for status change. */
if (tty->packet && tty->link->ctrl_status) {
unsigned char cs;
if (b != buf)
break;
cs = tty->link->ctrl_status;
tty->link->ctrl_status = 0;
put_user(cs, b++);
nr--;
break;
}
/* This statement must be first before checking for input
so that any interrupt will set the state back to
TASK_RUNNING. */
current->state = TASK_INTERRUPTIBLE;
if (((minimum - (b - buf)) < tty->minimum_to_wake) &&
((minimum - (b - buf)) >= 1))
tty->minimum_to_wake = (minimum - (b - buf));
if (!input_available_p(tty, 0)) {
if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
retval = -EIO;
break;
}
if (tty_hung_up_p(file))
break;
if (!timeout)
break;
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
clear_bit(TTY_DONT_FLIP, &tty->flags);
timeout = schedule_timeout(timeout);
set_bit(TTY_DONT_FLIP, &tty->flags);
continue;
}
current->state = TASK_RUNNING;
/* Deal with packet mode. */
if (tty->packet && b == buf) {
put_user(TIOCPKT_DATA, b++);
nr--;
}
if (tty->icanon) {
/* N.B. avoid overrun if nr == 0 */
while (nr && tty->read_cnt) {
int eol;
eol = test_and_clear_bit(tty->read_tail,
&tty->read_flags);
c = tty->read_buf[tty->read_tail];
tty->read_tail = ((tty->read_tail+1) &
(N_TTY_BUF_SIZE-1));
tty->read_cnt--;
if (!eol || (c != __DISABLED_CHAR)) {
put_user(c, b++);
nr--;
}
if (eol) {
/* this test should be redundant:
* we shouldn't be reading data if
* canon_data is 0
*/
if (--tty->canon_data < 0)
tty->canon_data = 0;
break;
}
}
} else {
int uncopied;
uncopied = copy_from_read_buf(tty, &b, &nr);
uncopied += copy_from_read_buf(tty, &b, &nr);
if (uncopied) {
retval = -EFAULT;
break;
}
}
/* If there is enough space in the read buffer now, let the
* low-level driver know. We use n_tty_chars_in_buffer() to
* check the buffer, as it now knows about canonical mode.
* Otherwise, if the driver is throttled and the line is
* longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode,
* we won't get any more characters.
*/
if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE)
check_unthrottle(tty);
if (b - buf >= minimum)
break;
if (time)
timeout = time;
}
clear_bit(TTY_DONT_FLIP, &tty->flags);
up(&tty->atomic_read);
remove_wait_queue(&tty->read_wait, &wait);
if (!waitqueue_active(&tty->read_wait))
tty->minimum_to_wake = minimum;
current->state = TASK_RUNNING;
size = b - buf;
if (size) {
retval = size;
if (nr)
clear_bit(TTY_PUSH, &tty->flags);
} else if (test_and_clear_bit(TTY_PUSH, &tty->flags))
goto do_it_again;
return retval;
}
static ssize_t read_chan(struct tty_struct *tty, struct file *file,
unsigned char __user *buf, size_t nr)
{
unsigned char __user *b = buf;
DECLARE_WAITQUEUE(wait, current);
int c;
int minimum, time;
ssize_t retval = 0;
ssize_t size;
long timeout;
unsigned long flags;
do_it_again:
if (!tty->read_buf) {
printk("n_tty_read_chan: called with read_buf == NULL?!?\n");
return -EIO;
}
c = job_control(tty, file);
if(c < 0)
return c;
minimum = time = 0;
timeout = MAX_SCHEDULE_TIMEOUT;
if (!tty->icanon) {
time = (HZ / 10) * TIME_CHAR(tty);
minimum = MIN_CHAR(tty);
if (minimum) {
if (time)
tty->minimum_to_wake = 1;
else if (!waitqueue_active(&tty->read_wait) ||
(tty->minimum_to_wake > minimum))
tty->minimum_to_wake = minimum;
} else {
timeout = 0;
if (time) {
timeout = time;
time = 0;
}
tty->minimum_to_wake = minimum = 1;
}
}
/*
* Internal serialization of reads.
*/
if (tx_cache_get_file_ro(file)->f_flags & O_NONBLOCK) {
if (!mutex_trylock(&tty->atomic_read_lock))
return -EAGAIN;
}
else {
if (mutex_lock_interruptible(&tty->atomic_read_lock))
return -ERESTARTSYS;
}
add_wait_queue(&tty->read_wait, &wait);
while (nr) {
/* First test for status change. */
if (tty->packet && tty->link->ctrl_status) {
unsigned char cs;
if (b != buf)
break;
cs = tty->link->ctrl_status;
tty->link->ctrl_status = 0;
if (put_user(cs, b++)) {
retval = -EFAULT;
b--;
break;
}
nr--;
break;
}
/* This statement must be first before checking for input
so that any interrupt will set the state back to
TASK_RUNNING. */
set_current_state(TASK_INTERRUPTIBLE);
if (((minimum - (b - buf)) < tty->minimum_to_wake) &&
((minimum - (b - buf)) >= 1))
tty->minimum_to_wake = (minimum - (b - buf));
if (!input_available_p(tty, 0)) {
if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
retval = -EIO;
break;
}
if (tty_hung_up_p(file))
break;
if (!timeout)
break;
if (tx_cache_get_file_ro(file)->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
n_tty_set_room(tty);
timeout = schedule_timeout(timeout);
continue;
}
__set_current_state(TASK_RUNNING);
/* Deal with packet mode. */
if (tty->packet && b == buf) {
if (put_user(TIOCPKT_DATA, b++)) {
retval = -EFAULT;
b--;
break;
}
nr--;
}
if (tty->icanon) {
/* N.B. avoid overrun if nr == 0 */
while (nr && tty->read_cnt) {
int eol;
eol = test_and_clear_bit(tty->read_tail,
tty->read_flags);
c = tty->read_buf[tty->read_tail];
spin_lock_irqsave(&tty->read_lock, flags);
tty->read_tail = ((tty->read_tail+1) &
(N_TTY_BUF_SIZE-1));
tty->read_cnt--;
if (eol) {
/* this test should be redundant:
* we shouldn't be reading data if
* canon_data is 0
*/
if (--tty->canon_data < 0)
tty->canon_data = 0;
}
spin_unlock_irqrestore(&tty->read_lock, flags);
if (!eol || (c != __DISABLED_CHAR)) {
if (put_user(c, b++)) {
retval = -EFAULT;
b--;
break;
}
nr--;
}
if (eol)
break;
}
if (retval)
break;
} else {
int uncopied;
uncopied = copy_from_read_buf(tty, &b, &nr);
uncopied += copy_from_read_buf(tty, &b, &nr);
if (uncopied) {
retval = -EFAULT;
break;
}
}
/* If there is enough space in the read buffer now, let the
* low-level driver know. We use n_tty_chars_in_buffer() to
* check the buffer, as it now knows about canonical mode.
* Otherwise, if the driver is throttled and the line is
* longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode,
* we won't get any more characters.
*/
if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) {
n_tty_set_room(tty);
check_unthrottle(tty);
}
if (b - buf >= minimum)
break;
if (time)
timeout = time;
}
mutex_unlock(&tty->atomic_read_lock);
remove_wait_queue(&tty->read_wait, &wait);
if (!waitqueue_active(&tty->read_wait))
tty->minimum_to_wake = minimum;
__set_current_state(TASK_RUNNING);
size = b - buf;
if (size) {
retval = size;
if (nr)
clear_bit(TTY_PUSH, &tty->flags);
} else if (test_and_clear_bit(TTY_PUSH, &tty->flags))
goto do_it_again;
n_tty_set_room(tty);
return retval;
}
static int read_chan(struct tty_struct *tty, struct file *file,
unsigned char *buf, unsigned int nr)
{
struct wait_queue wait = { current, NULL };
int c;
unsigned char *b = buf;
int minimum, time;
int retval = 0;
/* Job control check -- must be done at start and after
every sleep (POSIX.1 7.1.1.4). */
/* NOTE: not yet done after every sleep pending a thorough
check of the logic of this change. -- jlc */
/* don't stop on /dev/console */
if (file->f_inode->i_rdev != CONSOLE_DEV &&
current->tty == tty->line) {
if (tty->pgrp <= 0)
printk("read_chan: tty->pgrp <= 0!\n");
else if (current->pgrp != tty->pgrp) {
if (is_ignored(SIGTTIN) ||
is_orphaned_pgrp(current->pgrp))
return -EIO;
kill_pg(current->pgrp, SIGTTIN, 1);
return -ERESTARTSYS;
}
}
if (L_ICANON(tty)) {
minimum = time = 0;
current->timeout = (unsigned long) -1;
} else {
time = (HZ / 10) * TIME_CHAR(tty);
minimum = MIN_CHAR(tty);
if (minimum)
current->timeout = (unsigned long) -1;
else {
if (time) {
current->timeout = time + jiffies;
time = 0;
} else
current->timeout = 0;
minimum = 1;
}
}
add_wait_queue(&tty->secondary.proc_list, &wait);
while (1) {
/* First test for status change. */
if (tty->packet && tty->link->ctrl_status) {
if (b != buf)
break;
put_fs_byte(tty->link->ctrl_status, b++);
tty->link->ctrl_status = 0;
break;
}
/* This statement must be first before checking for input
so that any interrupt will set the state back to
TASK_RUNNING. */
current->state = TASK_INTERRUPTIBLE;
if (!input_available_p(tty)) {
if (tty->flags & (1 << TTY_SLAVE_CLOSED)) {
retval = -EIO;
break;
}
if (tty_hung_up_p(file))
break;
if (!current->timeout)
break;
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
if (current->signal & ~current->blocked) {
retval = -ERESTARTSYS;
break;
}
schedule();
continue;
}
current->state = TASK_RUNNING;
/* Deal with packet mode. */
if (tty->packet && b == buf) {
put_fs_byte(TIOCPKT_DATA, b++);
nr--;
}
while (1) {
int eol;
cli();
if (EMPTY(&tty->secondary)) {
sti();
break;
}
eol = clear_bit(tty->secondary.tail,
&tty->secondary_flags);
c = tty->secondary.buf[tty->secondary.tail];
if (!nr) {
/* Gobble up an immediately following EOF if
there is no more room in buf (this can
happen if the user "pushes" some characters
using ^D). This prevents the next read()
from falsely returning EOF. */
if (eol) {
if (c == __DISABLED_CHAR) {
tty->canon_data--;
INC(tty->secondary.tail);
} else {
set_bit(tty->secondary.tail,
&tty->secondary_flags);
}
}
sti();
break;
}
INC(tty->secondary.tail);
sti();
if (eol) {
if (--tty->canon_data < 0) {
printk("read_chan: canon_data < 0!\n");
tty->canon_data = 0;
}
if (c == __DISABLED_CHAR)
break;
put_fs_byte(c, b++);
nr--;
break;
}
put_fs_byte(c, b++);
nr--;
}
/* If there is enough space in the secondary queue now, let the
low-level driver know. */
if (tty->throttle && (LEFT(&tty->secondary) >= SQ_THRESHOLD_HW)
&& clear_bit(TTY_SQ_THROTTLED, &tty->flags))
tty->throttle(tty, TTY_THROTTLE_SQ_AVAIL);
if (b - buf >= minimum || !nr)
break;
if (time)
current->timeout = time + jiffies;
}
remove_wait_queue(&tty->secondary.proc_list, &wait);
current->state = TASK_RUNNING;
current->timeout = 0;
return (b - buf) ? b - buf : retval;
}
