From ee5aa7b8b98774f408d20a2f61f97a89ac66c29b Mon Sep 17 00:00:00 2001 From: Joe Peterson Date: Wed, 9 Sep 2009 15:03:13 -0600 Subject: [PATCH] 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 Cc: Linux Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/char/n_tty.c | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-) diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c index 4e28b35024ec..e6eeeb234e5d 100644 --- 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; } -- 2.20.1