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 for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Wed, 25 Apr 2012 11:52:28 -0400
From:	Jeff Moyer <jmoyer@...hat.com>
To:	Jörn Engel <joern@...fs.org>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: [RFC][PATCH] add blockconsole

Jörn Engel <joern@...fs.org> writes:

> On Wed, 25 April 2012 09:42:39 -0400, Jeff Moyer wrote:
>> 
>> Neat idea, but I'm curious to know how it works when the system panics
>> and you no longer can schedule the writeback thread.  What are the
>> limitations you've seen in practice?
>
> If the writeback thread doesn't get scheduled, you lose that
> information.  Formerly I did the submit_bio directly, but lockdep
> reminded me that I shouldn't do so from interrupt context.  Bummer.

Well, submit_bio can sleep, obviously.  Perhaps you could explore
registering a panic notifier, and then flush the logs from there?
Unfortunately, there is always the possibility that some required locks
will be taken, but it might get you a little bit further.  Or, you could
explore the route that the diskdump or lkcd folks took, implementing
their own polling mode drivers.

Cheers,
Jeff
--
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

Powered by Openwall GNU/*/Linux Powered by OpenVZ