lkml.org 
[lkml]   [2014]   [Feb]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3.13 36/99] n_tty: Fix stale echo output
Date
3.13-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Peter Hurley <peter@hurleysoftware.com>

commit e2613be5093d04e6589924d36a1e363eef3c87c7 upstream.

When echoes cannot be flushed to output (usually because the tty
has no more write room) and L_ECHO is subsequently turned off, then
when L_ECHO is turned back on, stale echoes are output.

Output completed echoes regardless of the L_ECHO setting:
1. before normal writes to that tty
2. if the tty was stopped by soft flow control and is being
restarted

Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/tty/n_tty.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -813,8 +813,7 @@ static void process_echoes(struct tty_st
struct n_tty_data *ldata = tty->disc_data;
size_t echoed;

- if ((!L_ECHO(tty) && !L_ECHONL(tty)) ||
- ldata->echo_mark == ldata->echo_tail)
+ if (ldata->echo_mark == ldata->echo_tail)
return;

mutex_lock(&ldata->output_lock);
@@ -1238,7 +1237,8 @@ n_tty_receive_signal_char(struct tty_str
if (L_ECHO(tty)) {
echo_char(c, tty);
commit_echoes(tty);
- }
+ } else
+ process_echoes(tty);
isig(signal, tty);
return;
}
@@ -1269,7 +1269,7 @@ n_tty_receive_char_special(struct tty_st
if (I_IXON(tty)) {
if (c == START_CHAR(tty)) {
start_tty(tty);
- commit_echoes(tty);
+ process_echoes(tty);
return 0;
}
if (c == STOP_CHAR(tty)) {
@@ -1821,8 +1821,10 @@ static void n_tty_set_termios(struct tty
* 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);
+ process_echoes(tty);
+ }

/* The termios change make the tty ready for I/O */
wake_up_interruptible(&tty->write_wait);



\
 
 \ /
  Last update: 2014-02-21 02:02    [W:0.396 / U:0.716 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site