| 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
| ||
|
Date: Tue, 5 Aug 2008 00:11:29 +0100 From: Alan Cox <alan@...rguk.ukuu.org.uk> To: Joe Peterson <joe@...rush.com> Cc: linux-kernel@...r.kernel.org Subject: Re: tty: ctrl-c not always echoed, especially under load On Mon, 04 Aug 2008 16:03:02 -0600 Joe Peterson <joe@...rush.com> wrote: > I am experiencing a rather intermittent and hard-to-reproduce issue in the tty > layer, and I am posting here to get ideas on how to debug it from those of you > who have delved into the tty internals. I suspect some kind of race is going on > or the echo is caught in the tty buffer when it gets flushed (and never makes it > to the tty). Heavy load (compiling, etc.) seems to make it more likely. > > When a signal character (e.g. ctrl-c) is received, the tty ldisc and driver are > flushed, the character is echoed (e.g. "^C" if echoctl is on), and the signal is > issued. Because the flush happens first, the echo should always appear on the > tty, but sometimes it does not. What I am wondering is how the echo could get > "swallowed". The code I have been using to test this is: 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. Alan -- 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/
Powered by blists - more mailing lists