diff options
| author |   Peter Hurley <peter@hurleysoftware.com> | 2014-02-11 16:34:55 -0500 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-13 10:02:19 -0800 |
| commit | e2613be5093d04e6589924d36a1e363eef3c87c7 (patch) | |
| tree | fd31a291d7f076ba1776cb490ae0baa75f54c712 /drivers | |
| parent | serial: sirf: fix kernel panic caused by unpaired spinlock (diff) | |
| download | linux-dev-e2613be5093d04e6589924d36a1e363eef3c87c7.tar.xz linux-dev-e2613be5093d04e6589924d36a1e363eef3c87c7.zip | |
n_tty: Fix stale echo output
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>
Cc: <stable@vger.kernel.org> # 3.13.x
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/n_tty.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 2747a3b20a50..d15624c1b751 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -817,8 +817,7 @@ static void process_echoes(struct tty_struct *tty) 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); @@ -1244,7 +1243,8 @@ n_tty_receive_signal_char(struct tty_struct *tty, int signal, unsigned char c) if (L_ECHO(tty)) { echo_char(c, tty); commit_echoes(tty); - } + } else + process_echoes(tty); isig(signal, tty); return; } @@ -1274,7 +1274,7 @@ n_tty_receive_char_special(struct tty_struct *tty, unsigned char c) 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)) { @@ -1820,8 +1820,10 @@ 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); + process_echoes(tty); + } /* The termios change make the tty ready for I/O */ if (waitqueue_active(&tty->write_wait)) |