From 62b263585bb5005d44a764c90d80f9c4bb8188c1 Mon Sep 17 00:00:00 2001 From: Joe Peterson Date: Wed, 9 Sep 2009 15:03:47 -0600 Subject: [PATCH] n_tty: move echoctl check and clean up logic Check L_ECHOCTL before insertting a character in the echo buffer (rather than as the buffer is processed), to be more consistent with when all other L_ flags are checked. Also cleaned up the related logic. Note that this and the previous patch ("n_tty: honor opost flag for echoes") were verified together by the reporters of the bug that patch addresses (http://bugs.linuxbase.org/show_bug.cgi?id=2692), and the test now passes. Signed-off-by: Joe Peterson Cc: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/char/n_tty.c | 46 +++++++++++++++++--------------------------- 1 file changed, 18 insertions(+), 28 deletions(-) diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c index e6eeeb234e5d..2e50f4dfc79c 100644 --- a/drivers/char/n_tty.c +++ b/drivers/char/n_tty.c @@ -576,33 +576,23 @@ static void process_echoes(struct tty_struct *tty) break; default: - if (iscntrl(op)) { - if (L_ECHOCTL(tty)) { - /* - * Ensure there is enough space - * for the whole ctrl pair. - */ - if (space < 2) { - no_space_left = 1; - break; - } - tty_put_char(tty, '^'); - tty_put_char(tty, op ^ 0100); - tty->column += 2; - space -= 2; - } else { - if (!space) { - no_space_left = 1; - break; - } - tty_put_char(tty, op); - space--; - } - } /* - * If above falls through, this was an - * undefined op. + * If the op is not a special byte code, + * it is a ctrl char tagged to be echoed + * as "^X" (where X is the letter + * representing the control char). + * Note that we must ensure there is + * enough space for the whole ctrl pair. + * */ + if (space < 2) { + no_space_left = 1; + break; + } + tty_put_char(tty, '^'); + tty_put_char(tty, op ^ 0100); + tty->column += 2; + space -= 2; cp += 2; nr -= 2; } @@ -809,8 +799,8 @@ static void echo_char_raw(unsigned char c, struct tty_struct *tty) * Echo user input back onto the screen. This must be called only when * L_ECHO(tty) is true. Called from the driver receive_buf path. * - * This variant tags control characters to be possibly echoed as - * as "^X" (where X is the letter representing the control char). + * This variant tags control characters to be echoed as "^X" + * (where X is the letter representing the control char). * * Locking: echo_lock to protect the echo buffer */ @@ -823,7 +813,7 @@ static void echo_char(unsigned char c, struct tty_struct *tty) add_echo_byte(ECHO_OP_START, tty); add_echo_byte(ECHO_OP_START, tty); } else { - if (iscntrl(c) && c != '\t') + if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t') add_echo_byte(ECHO_OP_START, tty); add_echo_byte(c, tty); } -- 2.30.2