n_tty: Fix apparent order of echoed output (1075a6e2) · Commits · 戴 / test

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. Cc: <stable@vger.kernel.org> # 3.12.x : n_tty: Fix missing newline echo Reported-by:

Karl Dahlke <eklhad@comcast.net> Reported-by:

Mikulas Patocka <mpatocka@redhat.com> Signed-off-by:

Peter Hurley <peter@hurleysoftware.com> Tested-by:

Karl Dahlke <eklhad@comcast.net> Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/n_tty.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -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;
		@@ -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
		@@ -811,10 +814,11 @@ static void process_echoes(struct tty_struct *tty)
		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_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;

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