n_tty: honor opost flag for echoes

Fixes the following bug:

      http://bugs.linuxbase.org/show_bug.cgi?id=2692

Causes processing of echoed characters (output from the echo buffer) to
honor the O_OPOST flag, which is consistent with the old behavior.

Note that this and the next patch ("n_tty: move echoctl check and
clean up logic") were verified together by the bug reporters, and
the test now passes.

Signed-off-by: Joe Peterson <joe@skyrush.com>
Cc: Linux Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index 4e28b35..e6eeeb2 100644 (file)
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -272,7 +272,8 @@ static inline int is_continuation(unsigned char c, struct tty_struct *tty)
  *
  *     This is a helper function that handles one output character
  *     (including special characters like TAB, CR, LF, etc.),
- *     putting the results in the tty driver's write buffer.
+ *     doing OPOST processing and putting the results in the
+ *     tty driver's write buffer.
  *
  *     Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY
  *     and NLDLY.  They simply aren't relevant in the world today.
@@ -350,8 +351,9 @@ static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
  *     @c: character (or partial unicode symbol)
  *     @tty: terminal device
  *
- *     Perform OPOST processing.  Returns -1 when the output device is
- *     full and the character must be retried.
+ *     Output one character with OPOST processing.
+ *     Returns -1 when the output device is full and the character
+ *     must be retried.
  *
  *     Locking: output_lock to protect column state and space left
  *              (also, this is called from n_tty_write under the
@@ -377,8 +379,11 @@ static int process_output(unsigned char c, struct tty_struct *tty)
 /**
  *     process_output_block            -       block post processor
  *     @tty: terminal device
- *     @inbuf: user buffer
- *     @nr: number of bytes
+ *     @buf: character buffer
+ *     @nr: number of bytes to output
+ *
+ *     Output a block of characters with OPOST processing.
+ *     Returns the number of characters output.
  *
  *     This path is used to speed up block console writes, among other
  *     things when processing blocks of output data. It handles only
@@ -605,12 +610,18 @@ static void process_echoes(struct tty_struct *tty)
                        if (no_space_left)
                                break;
                } else {
-                       int retval;
-
-                       retval = do_output_char(c, tty, space);
-                       if (retval < 0)
-                               break;
-                       space -= retval;
+                       if (O_OPOST(tty) &&
+                           !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
+                               int retval = do_output_char(c, tty, space);
+                               if (retval < 0)
+                                       break;
+                               space -= retval;
+                       } else {
+                               if (!space)
+                                       break;
+                               tty_put_char(tty, c);
+                               space -= 1;
+                       }
                        cp += 1;
                        nr -= 1;
                }