Messages in this thread Patch in this message | | | Date | Sat, 22 Dec 2007 07:19:58 -0700 | From | Joe Peterson <> | Subject | [PATCH] Fix IXANY and restart after signal (e.g. ctrl-C) in n_tty line discipline |
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Here is a patch that fixes a couple of issues with ttys in the stopped state. See patch below for more details.
Note that this patch assumes that my previous patch from last month (called "tty-enable-the-echoing-of-c-in-the-n_tty-discipline.patch" in the -mm tree) has been applied, since part of this patch is adjacent to that code.
Happy holidays! Joe Fix two N_TTY line discipline issues related to resuming a stopped TTY (typically done with ctrl-S):
1) Fix handling of character that resumes a stopped TTY (with IXANY)
With "stty ixany", the TTY line discipline would lose the first character after the stop, so typing, for example, "hi^Sthere" resulted in "hihere" (the 't' would cause the resume after ^S, but it would then be thrown away rather than processed as an input character). This was inconsistent with the behavior of other Unix systems.
2) Fix interrupt signal (e.g. ctrl-C) behavior in stopped TTYs
With "stty -ixany" (often the default), interrupt signals were ignored in a stopped TTY until the TTY was resumed with the start char (typically ctrl-Q), which was inconsistent with the behavior of other Unix systems.
Signed-off-by: Joe Peterson <joe@skyrush.com> ---
diff -puN a/drivers/char/n_tty.c~tty-fix-ixany-and-restart-after-signal-in-the-n_tty-discipline a/drivers/char/n_tty.c --- a/drivers/char/n_tty.c~tty-fix-ixany-and-restart-after-signal-in-the-n_tty-discipline 2007-12-20 11:35:05.000000000 -0700 +++ a/drivers/char/n_tty.c 2007-12-20 11:35:36.000000000 -0700 @@ -695,11 +695,8 @@ static inline void n_tty_receive_char(st return; } - if (tty->stopped && !tty->flow_stopped && - I_IXON(tty) && I_IXANY(tty)) { + if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) start_tty(tty); - return; - } if (I_ISTRIP(tty)) c &= 0x7f; @@ -769,6 +766,8 @@ static inline void n_tty_receive_char(st signal = SIGTSTP; if (c == SUSP_CHAR(tty)) { send_signal: + if (tty->stopped && !tty->flow_stopped && I_IXON(tty)) + start_tty(tty); /* * Echo character, and then send the signal. * Note that we do not use isig() here because we want | |