linux-kernel - Re: tty: ctrl-c not always echoed, especially under load

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 06 Aug 2008 14:17:29 -0600
From:	Joe Peterson <joe@...rush.com>
To:	Alan Cox <alan@...rguk.ukuu.org.uk>
CC:	linux-kernel@...r.kernel.org
Subject: Re: tty: ctrl-c not always echoed, especially under load

Alan Cox wrote:
> If the output buffer is full then echoed characters/^C etc will vanish the
> way n_tty implements its buffering internally. It's always worked that
> way.

One more observation:

In Linux, try this:

# cat > foo
hi^Sthere^Q
^D

(in other words, during the cat into "foo", type "hi", hit ^S, then type
"there", then hit ^Q, then, on the next line, ^D to end the file)

Note that the "there" does not appear after hitting ^Q, but it does
appear in the file.  So the characters were accepted, but they were not
echoed (not even saved for echo when the terminal is restarted).

This behavior differs from that of FreeBSD (just tried it for fun -
haven't tried other Unix's yet).  I have noticed other times that the
echo seems to get lost while the tty is stopped.  Not sure if all this
is related, but something seems amiss.  Thoughts?

					Thanks, Joe
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/