From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Karl Dahlke , Mikulas Patocka , Peter Hurley Subject: [PATCH 3.12 008/144] n_tty: Fix apparent order of echoed output Date: Mon, 6 Jan 2014 14:36:09 -0800 Message-Id: <20140106223745.568086451@linuxfoundation.org> In-Reply-To: <20140106223745.326293132@linuxfoundation.org> References: <20140106223745.326293132@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Hurley commit 1075a6e2dc7e2a96efc417b98dd98f57fdae985d upstream. With block processing of echoed output, observed output order is still required. Push completed echoes and echo commands prior to output. Introduce echo_mark echo buffer index, which tracks completed echo commands; ie., those submitted via commit_echoes but which may not have been committed. Ensure that completed echoes are output prior to subsequent terminal writes in process_echoes(). Fixes newline/prompt output order in cooked mode shell. Reported-by: Karl Dahlke Reported-by: Mikulas Patocka Signed-off-by: Peter Hurley Tested-by: Karl Dahlke Signed-off-by: Greg Kroah-Hartman --- drivers/tty/n_tty.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- 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_ { 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; @@ -787,6 +789,7 @@ static void commit_echoes(struct tty_str 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 @@ -811,10 +814,11 @@ static void process_echoes(struct tty_st size_t echoed; if ((!L_ECHO(tty) && !L_ECHONL(tty)) || - ldata->echo_commit == ldata->echo_tail) + 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); @@ -822,6 +826,7 @@ static void process_echoes(struct tty_st 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;