n_tty: Fix apparent order of echoed output
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 : 39434ab 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>
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 268b627..34aacaa 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -93,6 +93,7 @@
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 @@
{
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 @@
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 @@
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 @@
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;