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path: root/drivers/tty/n_tty.c
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Diffstat (limited to 'drivers/tty/n_tty.c')
-rw-r--r--drivers/tty/n_tty.c89
1 files changed, 49 insertions, 40 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index c9a9ddd1d0bc..34aacaaae14a 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -93,6 +93,7 @@ struct n_tty_data {
size_t canon_head;
size_t echo_head;
size_t echo_commit;
+ size_t echo_mark;
DECLARE_BITMAP(char_map, 256);
/* private to n_tty_receive_overrun (single-threaded) */
@@ -336,6 +337,7 @@ static void reset_buffer_flags(struct n_tty_data *ldata)
{
ldata->read_head = ldata->canon_head = ldata->read_tail = 0;
ldata->echo_head = ldata->echo_tail = ldata->echo_commit = 0;
+ ldata->echo_mark = 0;
ldata->line_start = 0;
ldata->erasing = 0;
@@ -767,8 +769,8 @@ static size_t __process_echoes(struct tty_struct *tty)
* of echo overrun before the next commit), then discard enough
* data at the tail to prevent a subsequent overrun */
while (ldata->echo_commit - tail >= ECHO_DISCARD_WATERMARK) {
- if (echo_buf(ldata, tail == ECHO_OP_START)) {
- if (echo_buf(ldata, tail) == ECHO_OP_ERASE_TAB)
+ if (echo_buf(ldata, tail) == ECHO_OP_START) {
+ if (echo_buf(ldata, tail + 1) == ECHO_OP_ERASE_TAB)
tail += 3;
else
tail += 2;
@@ -787,6 +789,7 @@ static void commit_echoes(struct tty_struct *tty)
size_t head;
head = ldata->echo_head;
+ ldata->echo_mark = head;
old = ldata->echo_commit - ldata->echo_tail;
/* Process committed echoes if the accumulated # of bytes
@@ -810,10 +813,12 @@ static void process_echoes(struct tty_struct *tty)
struct n_tty_data *ldata = tty->disc_data;
size_t echoed;
- if (!L_ECHO(tty) || ldata->echo_commit == ldata->echo_tail)
+ if ((!L_ECHO(tty) && !L_ECHONL(tty)) ||
+ ldata->echo_mark == ldata->echo_tail)
return;
mutex_lock(&ldata->output_lock);
+ ldata->echo_commit = ldata->echo_mark;
echoed = __process_echoes(tty);
mutex_unlock(&ldata->output_lock);
@@ -821,11 +826,13 @@ static void process_echoes(struct tty_struct *tty)
tty->ops->flush_chars(tty);
}
+/* NB: echo_mark and echo_head should be equivalent here */
static void flush_echoes(struct tty_struct *tty)
{
struct n_tty_data *ldata = tty->disc_data;
- if (!L_ECHO(tty) || ldata->echo_commit == ldata->echo_head)
+ if ((!L_ECHO(tty) && !L_ECHONL(tty)) ||
+ ldata->echo_commit == ldata->echo_head)
return;
mutex_lock(&ldata->output_lock);
@@ -1752,21 +1759,14 @@ int is_ignored(int sig)
static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
{
struct n_tty_data *ldata = tty->disc_data;
- int canon_change = 1;
- if (old)
- canon_change = (old->c_lflag ^ tty->termios.c_lflag) & ICANON;
- if (canon_change) {
+ if (!old || (old->c_lflag ^ tty->termios.c_lflag) & ICANON) {
bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
- ldata->line_start = 0;
- ldata->canon_head = ldata->read_tail;
+ ldata->line_start = ldata->canon_head = ldata->read_tail;
ldata->erasing = 0;
ldata->lnext = 0;
}
- if (canon_change && !L_ICANON(tty) && read_cnt(ldata))
- wake_up_interruptible(&tty->read_wait);
-
ldata->icanon = (L_ICANON(tty) != 0);
if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) ||
@@ -1821,9 +1821,8 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
* Fix tty hang when I_IXON(tty) is cleared, but the tty
* been stopped by STOP_CHAR(tty) before it.
*/
- if (!I_IXON(tty) && old && (old->c_iflag & IXON) && !tty->flow_stopped) {
+ if (!I_IXON(tty) && old && (old->c_iflag & IXON) && !tty->flow_stopped)
start_tty(tty);
- }
/* The termios change make the tty ready for I/O */
wake_up_interruptible(&tty->write_wait);
@@ -2006,7 +2005,10 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
found = 1;
size = N_TTY_BUF_SIZE - tail;
- n = (found + eol + size) & (N_TTY_BUF_SIZE - 1);
+ n = eol - tail;
+ if (n > 4096)
+ n += 4096;
+ n += found;
c = n;
if (found && read_buf(ldata, eol) == __DISABLED_CHAR) {
@@ -2184,28 +2186,34 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
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);
- up_read(&tty->termios_rwsem);
+ up_read(&tty->termios_rwsem);
+ tty_flush_to_ldisc(tty);
+ down_read(&tty->termios_rwsem);
+ if (!input_available_p(tty, 0)) {
+ retval = -EIO;
+ break;
+ }
+ } else {
+ 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);
+ up_read(&tty->termios_rwsem);
- timeout = schedule_timeout(timeout);
+ timeout = schedule_timeout(timeout);
- down_read(&tty->termios_rwsem);
- continue;
+ down_read(&tty->termios_rwsem);
+ continue;
+ }
}
__set_current_state(TASK_RUNNING);
@@ -2245,18 +2253,19 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
if (time)
timeout = time;
}
- mutex_unlock(&ldata->atomic_read_lock);
- remove_wait_queue(&tty->read_wait, &wait);
+ n_tty_set_room(tty);
+ up_read(&tty->termios_rwsem);
+ remove_wait_queue(&tty->read_wait, &wait);
if (!waitqueue_active(&tty->read_wait))
ldata->minimum_to_wake = minimum;
+ mutex_unlock(&ldata->atomic_read_lock);
+
__set_current_state(TASK_RUNNING);
if (b - buf)
retval = b - buf;
- n_tty_set_room(tty);
- up_read(&tty->termios_rwsem);
return retval;
}
generated by cgit v1.2.3 (git 2.0.4) at 2024-06-12 07:26:58 +0000