/*
* n_tty.c --- implements the N_TTY line discipline.
- *
+ *
* This code used to be in tty_io.c, but things are getting hairy
* enough that it made sense to split things off. (The N_TTY
* processing has changed so much that it's hardly recognizable,
*
* Note that the open routine for N_TTY is guaranteed never to return
* an error. This is because Linux will fall back to setting a line
- * to N_TTY if it can not switch to any other line discipline.
+ * to N_TTY if it can not switch to any other line discipline.
*
* Written by Theodore Ts'o, Copyright 1994.
- *
+ *
* This file also contains code originally written by Linus Torvalds,
* Copyright 1991, 1992, 1993, and by Julian Cowley, Copyright 1994.
- *
+ *
* This file may be redistributed under the terms of the GNU General Public
* License.
*
* Reduced memory usage for older ARM systems - Russell King.
*
- * 2000/01/20 Fixed SMP locking on put_tty_queue using bits of
+ * 2000/01/20 Fixed SMP locking on put_tty_queue using bits of
* the patch by Andrew J. Kroll <ag784@freenet.buffalo.edu>
* who actually finally proved there really was a race.
*
* 2002/03/18 Implemented n_tty_wakeup to send SIGIO POLL_OUTs to
* waiting writing processes-Sapan Bhatia <sapan@corewars.org>.
- * Also fixed a bug in BLOCKING mode where write_chan returns
+ * Also fixed a bug in BLOCKING mode where n_tty_write returns
* EAGAIN
*/
static void n_tty_set_room(struct tty_struct *tty)
{
+ /* tty->read_cnt is not read locked ? */
int left = N_TTY_BUF_SIZE - tty->read_cnt - 1;
/*
}
}
+/**
+ * put_tty_queue - add character to tty
+ * @c: character
+ * @tty: tty device
+ *
+ * Add a character to the tty read_buf queue. This is done under the
+ * read_lock to serialize character addition and also to protect us
+ * against parallel reads or flushes
+ */
+
static void put_tty_queue(unsigned char c, struct tty_struct *tty)
{
unsigned long flags;
* check_unthrottle - allow new receive data
* @tty; tty device
*
- * Check whether to call the driver.unthrottle function.
- * We test the TTY_THROTTLED bit first so that it always
- * indicates the current state. The decision about whether
- * it is worth allowing more input has been taken by the caller.
+ * Check whether to call the driver unthrottle functions
+ *
* Can sleep, may be called under the atomic_read_lock mutex but
* this is not guaranteed.
*/
-
-static void check_unthrottle(struct tty_struct * tty)
+static void check_unthrottle(struct tty_struct *tty)
{
- if (tty->count &&
- test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
- tty->driver->unthrottle)
- tty->driver->unthrottle(tty);
+ if (tty->count)
+ tty_unthrottle(tty);
}
/**
* reset_buffer_flags - reset buffer state
* @tty: terminal to reset
*
- * Reset the read buffer counters, clear the flags,
+ * Reset the read buffer counters, clear the flags,
* and make sure the driver is unthrottled. Called
* from n_tty_open() and n_tty_flush_buffer().
+ *
+ * Locking: tty_read_lock for read fields.
*/
static void reset_buffer_flags(struct tty_struct *tty)
{
* at hangup) or when the N_TTY line discipline internally has to
* clean the pending queue (for example some signals).
*
- * FIXME: tty->ctrl_status is not spinlocked and relies on
- * lock_kernel() still.
+ * Locking: ctrl_lock, read_lock.
*/
-
-static void n_tty_flush_buffer(struct tty_struct * tty)
+
+static void n_tty_flush_buffer(struct tty_struct *tty)
{
+ unsigned long flags;
/* clear everything and unthrottle the driver */
reset_buffer_flags(tty);
-
+
if (!tty->link)
return;
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
if (tty->link->packet) {
tty->ctrl_status |= TIOCPKT_FLUSHREAD;
wake_up_interruptible(&tty->link->read_wait);
}
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
}
/**
* @tty: tty device
*
* Report the number of characters buffered to be delivered to user
- * at this instant in time.
+ * at this instant in time.
+ *
+ * Locking: read_lock
*/
-
+
static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
{
unsigned long flags;
* character. We use this to correctly compute the on screen size
* of the character when printing
*/
-
+
static inline int is_utf8_continuation(unsigned char c)
{
return (c & 0xc0) == 0x80;
* Returns true if the utf8 character 'c' is a multibyte continuation
* character and the terminal is in unicode mode.
*/
-
+
static inline int is_continuation(unsigned char c, struct tty_struct *tty)
{
return I_IUTF8(tty) && is_utf8_continuation(c);
* relevant in the world today. If you ever need them, add them here.
*
* Called from both the receive and transmit sides and can be called
- * re-entrantly. Relies on lock_kernel() still.
+ * re-entrantly. Relies on lock_kernel() for tty->column state.
*/
-
+
static int opost(unsigned char c, struct tty_struct *tty)
{
int space, spaces;
- space = tty->driver->write_room(tty);
+ space = tty_write_room(tty);
if (!space)
return -1;
+ lock_kernel();
if (O_OPOST(tty)) {
switch (c) {
case '\n':
if (O_ONLRET(tty))
tty->column = 0;
if (O_ONLCR(tty)) {
- if (space < 2)
+ if (space < 2) {
+ unlock_kernel();
return -1;
- tty->driver->put_char(tty, '\r');
+ }
+ tty_put_char(tty, '\r');
tty->column = 0;
}
tty->canon_column = tty->column;
break;
case '\r':
- if (O_ONOCR(tty) && tty->column == 0)
+ if (O_ONOCR(tty) && tty->column == 0) {
+ unlock_kernel();
return 0;
+ }
if (O_OCRNL(tty)) {
c = '\n';
if (O_ONLRET(tty))
case '\t':
spaces = 8 - (tty->column & 7);
if (O_TABDLY(tty) == XTABS) {
- if (space < spaces)
+ if (space < spaces) {
+ unlock_kernel();
return -1;
+ }
tty->column += spaces;
- tty->driver->write(tty, " ", spaces);
+ tty->ops->write(tty, " ", spaces);
+ unlock_kernel();
return 0;
}
tty->column += spaces;
break;
}
}
- tty->driver->put_char(tty, c);
+ tty_put_char(tty, c);
+ unlock_kernel();
return 0;
}
* the simple cases normally found and helps to generate blocks of
* symbols for the console driver and thus improve performance.
*
- * Called from write_chan under the tty layer write lock.
+ * Called from n_tty_write under the tty layer write lock. Relies
+ * on lock_kernel for the tty->column state.
*/
-
-static ssize_t opost_block(struct tty_struct * tty,
- const unsigned char * buf, unsigned int nr)
+
+static ssize_t opost_block(struct tty_struct *tty,
+ const unsigned char *buf, unsigned int nr)
{
int space;
int i;
const unsigned char *cp;
- space = tty->driver->write_room(tty);
+ space = tty_write_room(tty);
if (!space)
return 0;
if (nr > space)
nr = space;
+ lock_kernel();
for (i = 0, cp = buf; i < nr; i++, cp++) {
switch (*cp) {
case '\n':
}
}
break_out:
- if (tty->driver->flush_chars)
- tty->driver->flush_chars(tty);
- i = tty->driver->write(tty, buf, i);
+ if (tty->ops->flush_chars)
+ tty->ops->flush_chars(tty);
+ i = tty->ops->write(tty, buf, i);
+ unlock_kernel();
return i;
}
/**
- * put_char - write character to driver
- * @c: character (or part of unicode symbol)
- * @tty: terminal device
- *
- * Queue a byte to the driver layer for output
- */
-
-static inline void put_char(unsigned char c, struct tty_struct *tty)
-{
- tty->driver->put_char(tty, c);
-}
-
-/**
* echo_char - echo characters
* @c: unicode byte to echo
* @tty: terminal device
*
- * Echo user input back onto the screen. This must be called only when
+ * Echo user input back onto the screen. This must be called only when
* L_ECHO(tty) is true. Called from the driver receive_buf path.
+ *
+ * Relies on BKL for tty column locking
*/
static void echo_char(unsigned char c, struct tty_struct *tty)
{
if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t') {
- put_char('^', tty);
- put_char(c ^ 0100, tty);
+ tty_put_char(tty, '^');
+ tty_put_char(tty, c ^ 0100);
tty->column += 2;
} else
opost(c, tty);
}
+/**
+ * finsh_erasing - complete erase
+ * @tty: tty doing the erase
+ *
+ * Relies on BKL for tty column locking
+ */
static inline void finish_erasing(struct tty_struct *tty)
{
if (tty->erasing) {
- put_char('/', tty);
+ tty_put_char(tty, '/');
tty->column++;
tty->erasing = 0;
}
* Perform erase and necessary output when an erase character is
* present in the stream from the driver layer. Handles the complexities
* of UTF-8 multibyte symbols.
+ *
+ * Locking: read_lock for tty buffers, BKL for column/erasing state
*/
-
+
static void eraser(unsigned char c, struct tty_struct *tty)
{
enum { ERASE, WERASE, KILL } kill_type;
int head, seen_alnums, cnt;
unsigned long flags;
+ /* FIXME: locking needed ? */
if (tty->read_head == tty->canon_head) {
/* opost('\a', tty); */ /* what do you think? */
return;
}
seen_alnums = 0;
+ /* FIXME: Locking ?? */
while (tty->read_head != tty->canon_head) {
head = tty->read_head;
if (L_ECHO(tty)) {
if (L_ECHOPRT(tty)) {
if (!tty->erasing) {
- put_char('\\', tty);
+ tty_put_char(tty, '\\');
tty->column++;
tty->erasing = 1;
}
echo_char(c, tty);
while (--cnt > 0) {
head = (head+1) & (N_TTY_BUF_SIZE-1);
- put_char(tty->read_buf[head], tty);
+ tty_put_char(tty, tty->read_buf[head]);
}
} else if (kill_type == ERASE && !L_ECHOE(tty)) {
echo_char(ERASE_CHAR(tty), tty);
/* should never happen */
if (tty->column > 0x80000000)
- tty->column = 0;
+ tty->column = 0;
/* Now backup to that column. */
while (tty->column > col) {
/* Can't use opost here. */
- put_char('\b', tty);
+ tty_put_char(tty, '\b');
if (tty->column > 0)
tty->column--;
}
} else {
if (iscntrl(c) && L_ECHOCTL(tty)) {
- put_char('\b', tty);
- put_char(' ', tty);
- put_char('\b', tty);
+ tty_put_char(tty, '\b');
+ tty_put_char(tty, ' ');
+ tty_put_char(tty, '\b');
if (tty->column > 0)
tty->column--;
}
if (!iscntrl(c) || L_ECHOCTL(tty)) {
- put_char('\b', tty);
- put_char(' ', tty);
- put_char('\b', tty);
+ tty_put_char(tty, '\b');
+ tty_put_char(tty, ' ');
+ tty_put_char(tty, '\b');
if (tty->column > 0)
tty->column--;
}
* may caus terminal flushing to take place according to the termios
* settings and character used. Called from the driver receive_buf
* path so serialized.
+ *
+ * Locking: ctrl_lock, read_lock (both via flush buffer)
*/
-
+
static inline void isig(int sig, struct tty_struct *tty, int flush)
{
if (tty->pgrp)
kill_pgrp(tty->pgrp, sig, 1);
if (flush || !L_NOFLSH(tty)) {
n_tty_flush_buffer(tty);
- if (tty->driver->flush_buffer)
- tty->driver->flush_buffer(tty);
+ tty_driver_flush_buffer(tty);
}
}
*
* Called from the receive_buf path so single threaded.
*/
-
+
static inline void n_tty_receive_break(struct tty_struct *tty)
{
if (I_IGNBRK(tty))
* need locking as num_overrun and overrun_time are function
* private.
*/
-
+
static inline void n_tty_receive_overrun(struct tty_struct *tty)
{
char buf[64];
static inline void n_tty_receive_parity_error(struct tty_struct *tty,
unsigned char c)
{
- if (I_IGNPAR(tty)) {
+ if (I_IGNPAR(tty))
return;
- }
if (I_PARMRK(tty)) {
put_tty_queue('\377', tty);
put_tty_queue('\0', tty);
* @c: character
*
* Process an individual character of input received from the driver.
- * This is serialized with respect to itself by the rules for the
+ * This is serialized with respect to itself by the rules for the
* driver above.
*/
put_tty_queue(c, tty);
return;
}
-
+
if (I_ISTRIP(tty))
c &= 0x7f;
if (I_IUCLC(tty) && L_IEXTEN(tty))
if (tty->stopped && !tty->flow_stopped && I_IXON(tty) &&
((I_IXANY(tty) && c != START_CHAR(tty) && c != STOP_CHAR(tty)) ||
- c == INTR_CHAR(tty) || c == QUIT_CHAR(tty)))
+ c == INTR_CHAR(tty) || c == QUIT_CHAR(tty) || c == SUSP_CHAR(tty)))
start_tty(tty);
if (tty->closing) {
tty->lnext = 0;
if (L_ECHO(tty)) {
if (tty->read_cnt >= N_TTY_BUF_SIZE-1) {
- put_char('\a', tty); /* beep if no space */
+ tty_put_char(tty, '\a'); /* beep if no space */
return;
}
/* Record the column of first canon char. */
put_tty_queue(c, tty);
return;
}
-
- if (c == '\r') {
- if (I_IGNCR(tty))
- return;
- if (I_ICRNL(tty))
- c = '\n';
- } else if (c == '\n' && I_INLCR(tty))
- c = '\r';
+
if (I_IXON(tty)) {
if (c == START_CHAR(tty)) {
start_tty(tty);
return;
}
}
+
if (L_ISIG(tty)) {
int signal;
signal = SIGINT;
*/
if (!L_NOFLSH(tty)) {
n_tty_flush_buffer(tty);
- if (tty->driver->flush_buffer)
- tty->driver->flush_buffer(tty);
+ tty_driver_flush_buffer(tty);
}
if (L_ECHO(tty))
echo_char(c, tty);
return;
}
}
+
+ if (c == '\r') {
+ if (I_IGNCR(tty))
+ return;
+ if (I_ICRNL(tty))
+ c = '\n';
+ } else if (c == '\n' && I_INLCR(tty))
+ c = '\r';
+
if (tty->icanon) {
if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) ||
(c == WERASE_CHAR(tty) && L_IEXTEN(tty))) {
if (L_ECHO(tty)) {
finish_erasing(tty);
if (L_ECHOCTL(tty)) {
- put_char('^', tty);
- put_char('\b', tty);
+ tty_put_char(tty, '^');
+ tty_put_char(tty, '\b');
}
}
return;
if (c == '\n') {
if (L_ECHO(tty) || L_ECHONL(tty)) {
if (tty->read_cnt >= N_TTY_BUF_SIZE-1)
- put_char('\a', tty);
+ tty_put_char(tty, '\a');
opost('\n', tty);
}
goto handle_newline;
}
if (c == EOF_CHAR(tty)) {
- if (tty->canon_head != tty->read_head)
- set_bit(TTY_PUSH, &tty->flags);
+ if (tty->canon_head != tty->read_head)
+ set_bit(TTY_PUSH, &tty->flags);
c = __DISABLED_CHAR;
goto handle_newline;
}
*/
if (L_ECHO(tty)) {
if (tty->read_cnt >= N_TTY_BUF_SIZE-1)
- put_char('\a', tty);
+ tty_put_char(tty, '\a');
/* Record the column of first canon char. */
if (tty->canon_head == tty->read_head)
tty->canon_column = tty->column;
if (I_PARMRK(tty) && c == (unsigned char) '\377')
put_tty_queue(c, tty);
- handle_newline:
+handle_newline:
spin_lock_irqsave(&tty->read_lock, flags);
set_bit(tty->read_head, tty->read_flags);
put_tty_queue_nolock(c, tty);
return;
}
}
-
+
finish_erasing(tty);
if (L_ECHO(tty)) {
if (tty->read_cnt >= N_TTY_BUF_SIZE-1) {
- put_char('\a', tty); /* beep if no space */
+ tty_put_char(tty, '\a'); /* beep if no space */
return;
}
if (c == '\n')
put_tty_queue(c, tty);
put_tty_queue(c, tty);
-}
+}
/**
static void n_tty_write_wakeup(struct tty_struct *tty)
{
- if (tty->fasync)
- {
- set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+ if (tty->fasync) {
+ set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
kill_fasync(&tty->fasync, SIGIO, POLL_OUT);
}
- return;
}
/**
* not from interrupt context. The driver is responsible for making
* calls one at a time and in order (or using flush_to_ldisc)
*/
-
+
static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
char *fp, int count)
{
tty->read_cnt += i;
spin_unlock_irqrestore(&tty->read_lock, cpuflags);
} else {
- for (i=count, p = cp, f = fp; i; i--, p++) {
+ for (i = count, p = cp, f = fp; i; i--, p++) {
if (f)
flags = *f++;
switch (flags) {
n_tty_receive_overrun(tty);
break;
default:
- printk("%s: unknown flag %d\n",
+ printk(KERN_ERR "%s: unknown flag %d\n",
tty_name(tty, buf), flags);
break;
}
}
- if (tty->driver->flush_chars)
- tty->driver->flush_chars(tty);
+ if (tty->ops->flush_chars)
+ tty->ops->flush_chars(tty);
}
n_tty_set_room(tty);
* mode. We don't want to throttle the driver if we're in
* canonical mode and don't have a newline yet!
*/
- if (tty->receive_room < TTY_THRESHOLD_THROTTLE) {
- /* check TTY_THROTTLED first so it indicates our state */
- if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
- tty->driver->throttle)
- tty->driver->throttle(tty);
- }
+ if (tty->receive_room < TTY_THRESHOLD_THROTTLE)
+ tty_throttle(tty);
}
int is_ignored(int sig)
{
return (sigismember(¤t->blocked, sig) ||
- current->sighand->action[sig-1].sa.sa_handler == SIG_IGN);
+ current->sighand->action[sig-1].sa.sa_handler == SIG_IGN);
}
/**
*
* Called by the tty layer when the user changes termios flags so
* that the line discipline can plan ahead. This function cannot sleep
- * and is protected from re-entry by the tty layer. The user is
+ * and is protected from re-entry by the tty layer. The user is
* guaranteed that this function will not be re-entered or in progress
* when the ldisc is closed.
+ *
+ * Locking: Caller holds tty->termios_mutex
*/
-
-static void n_tty_set_termios(struct tty_struct *tty, struct ktermios * old)
+
+static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
{
- if (!tty)
- return;
-
+ int canon_change = 1;
+ BUG_ON(!tty);
+
+ if (old)
+ canon_change = (old->c_lflag ^ tty->termios->c_lflag) & ICANON;
+ if (canon_change) {
+ memset(&tty->read_flags, 0, sizeof tty->read_flags);
+ tty->canon_head = tty->read_tail;
+ tty->canon_data = 0;
+ tty->erasing = 0;
+ }
+
+ if (canon_change && !L_ICANON(tty) && tty->read_cnt)
+ wake_up_interruptible(&tty->read_wait);
+
tty->icanon = (L_ICANON(tty) != 0);
if (test_bit(TTY_HW_COOK_IN, &tty->flags)) {
tty->raw = 1;
tty->real_raw = 0;
}
n_tty_set_room(tty);
+ /* The termios change make the tty ready for I/O */
+ wake_up_interruptible(&tty->write_wait);
+ wake_up_interruptible(&tty->read_wait);
}
/**
* n_tty_close - close the ldisc for this tty
* @tty: device
*
- * Called from the terminal layer when this line discipline is
- * being shut down, either because of a close or becsuse of a
+ * Called from the terminal layer when this line discipline is
+ * being shut down, either because of a close or becsuse of a
* discipline change. The function will not be called while other
* ldisc methods are in progress.
*/
-
+
static void n_tty_close(struct tty_struct *tty)
{
n_tty_flush_buffer(tty);
* n_tty_open - open an ldisc
* @tty: terminal to open
*
- * Called when this line discipline is being attached to the
+ * Called when this line discipline is being attached to the
* terminal device. Can sleep. Called serialized so that no
* other events will occur in parallel. No further open will occur
* until a close.
* @b: user data
* @nr: size of data
*
- * Helper function to speed up read_chan. It is only called when
+ * Helper function to speed up n_tty_read. It is only called when
* ICANON is off; it copies characters straight from the tty queue to
* user space directly. It can be profitably called twice; once to
* drain the space from the tail pointer to the (physical) end of the
* Called under the tty->atomic_read_lock sem
*
*/
-
+
static int copy_from_read_buf(struct tty_struct *tty,
unsigned char __user **b,
size_t *nr)
return retval;
}
-extern ssize_t redirected_tty_write(struct file *,const char *,size_t,loff_t *);
+extern ssize_t redirected_tty_write(struct file *, const char __user *,
+ size_t, loff_t *);
/**
* job_control - check job control
* @file: file handle
*
* Perform job control management checks on this file/tty descriptor
- * and if appropriate send any needed signals and return a negative
+ * and if appropriate send any needed signals and return a negative
* error code if action should be taken.
+ *
+ * FIXME:
+ * Locking: None - redirected write test is safe, testing
+ * current->signal should possibly lock current->sighand
+ * pgrp locking ?
*/
-
+
static int job_control(struct tty_struct *tty, struct file *file)
{
/* Job control check -- must be done at start and after
if (file->f_op->write != redirected_tty_write &&
current->signal->tty == tty) {
if (!tty->pgrp)
- printk("read_chan: no tty->pgrp!\n");
+ printk(KERN_ERR "n_tty_read: no tty->pgrp!\n");
else if (task_pgrp(current) != tty->pgrp) {
if (is_ignored(SIGTTIN) ||
is_current_pgrp_orphaned())
}
return 0;
}
-
+
/**
- * read_chan - read function for tty
+ * n_tty_read - read function for tty
* @tty: tty device
* @file: file object
* @buf: userspace buffer pointer
*
* This code must be sure never to sleep through a hangup.
*/
-
-static ssize_t read_chan(struct tty_struct *tty, struct file *file,
+
+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;
ssize_t size;
long timeout;
unsigned long flags;
+ int packet;
do_it_again:
- if (!tty->read_buf) {
- printk("n_tty_read_chan: called with read_buf == NULL?!?\n");
- return -EIO;
- }
+ BUG_ON(!tty->read_buf);
c = job_control(tty, file);
- if(c < 0)
+ if (c < 0)
return c;
-
+
minimum = time = 0;
timeout = MAX_SCHEDULE_TIMEOUT;
if (!tty->icanon) {
if (file->f_flags & O_NONBLOCK) {
if (!mutex_trylock(&tty->atomic_read_lock))
return -EAGAIN;
- }
- else {
+ } else {
if (mutex_lock_interruptible(&tty->atomic_read_lock))
return -ERESTARTSYS;
}
+ packet = tty->packet;
add_wait_queue(&tty->read_wait, &wait);
while (nr) {
/* First test for status change. */
- if (tty->packet && tty->link->ctrl_status) {
+ 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--;
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;
retval = -ERESTARTSYS;
break;
}
+ /* FIXME: does n_tty_set_room need locking ? */
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 (packet && b == buf) {
if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
retval = -EFAULT;
b--;
if (tty->icanon) {
/* N.B. avoid overrun if nr == 0 */
while (nr && tty->read_cnt) {
- int eol;
+ int eol;
eol = test_and_clear_bit(tty->read_tail,
tty->read_flags);
break;
} else {
int uncopied;
+ /* The copy function takes the read lock and handles
+ locking internally for this case */
uncopied = copy_from_read_buf(tty, &b, &nr);
uncopied += copy_from_read_buf(tty, &b, &nr);
if (uncopied) {
if (size) {
retval = size;
if (nr)
- clear_bit(TTY_PUSH, &tty->flags);
+ 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;
}
/**
- * write_chan - write function for tty
+ * n_tty_write - write function for tty
* @tty: tty device
* @file: file object
* @buf: userspace buffer pointer
*
* This code must be sure never to sleep through a hangup.
*/
-
-static ssize_t write_chan(struct tty_struct * tty, struct file * file,
- const unsigned char * buf, size_t nr)
+
+static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
+ const unsigned char *buf, size_t nr)
{
const unsigned char *b = buf;
DECLARE_WAITQUEUE(wait, current);
break;
b++; nr--;
}
- if (tty->driver->flush_chars)
- tty->driver->flush_chars(tty);
+ if (tty->ops->flush_chars)
+ tty->ops->flush_chars(tty);
} else {
while (nr > 0) {
- c = tty->driver->write(tty, b, nr);
+ c = tty->ops->write(tty, b, nr);
if (c < 0) {
retval = c;
goto break_out;
}
/**
- * normal_poll - poll method for N_TTY
+ * n_tty_poll - poll method for N_TTY
* @tty: terminal device
* @file: file accessing it
* @wait: poll table
*
* This code must be sure never to sleep through a hangup.
* Called without the kernel lock held - fine
- *
- * FIXME: if someone changes the VMIN or discipline settings for the
- * terminal while another process is in poll() the poll does not
- * recompute the new limits. Possibly set_termios should issue
- * a read wakeup to fix this bug.
*/
-
-static unsigned int normal_poll(struct tty_struct * tty, struct file * file, poll_table *wait)
+
+static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
+ poll_table *wait)
{
unsigned int mask = 0;
else
tty->minimum_to_wake = 1;
}
- if (!tty_is_writelocked(tty) &&
- tty->driver->chars_in_buffer(tty) < WAKEUP_CHARS &&
- tty->driver->write_room(tty) > 0)
+ 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;
}
-struct tty_ldisc tty_ldisc_N_TTY = {
+static unsigned long inq_canon(struct tty_struct *tty)
+{
+ int nr, head, tail;
+
+ if (!tty->canon_data)
+ return 0;
+ head = tty->canon_head;
+ tail = tty->read_tail;
+ nr = (head - tail) & (N_TTY_BUF_SIZE-1);
+ /* Skip EOF-chars.. */
+ while (head != tail) {
+ if (test_bit(tail, tty->read_flags) &&
+ tty->read_buf[tail] == __DISABLED_CHAR)
+ nr--;
+ tail = (tail+1) & (N_TTY_BUF_SIZE-1);
+ }
+ return nr;
+}
+
+static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int retval;
+
+ switch (cmd) {
+ case TIOCOUTQ:
+ return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
+ case TIOCINQ:
+ /* FIXME: Locking */
+ retval = tty->read_cnt;
+ if (L_ICANON(tty))
+ retval = inq_canon(tty);
+ return put_user(retval, (unsigned int __user *) arg);
+ default:
+ return n_tty_ioctl_helper(tty, file, cmd, arg);
+ }
+}
+
+struct tty_ldisc_ops tty_ldisc_N_TTY = {
.magic = TTY_LDISC_MAGIC,
.name = "n_tty",
.open = n_tty_open,
.close = n_tty_close,
.flush_buffer = n_tty_flush_buffer,
.chars_in_buffer = n_tty_chars_in_buffer,
- .read = read_chan,
- .write = write_chan,
+ .read = n_tty_read,
+ .write = n_tty_write,
.ioctl = n_tty_ioctl,
.set_termios = n_tty_set_termios,
- .poll = normal_poll,
+ .poll = n_tty_poll,
.receive_buf = n_tty_receive_buf,
.write_wakeup = n_tty_write_wakeup
};
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff