linux-kernel - Re: [PATCH] Fix leap second message hang

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] [day] [month] [year] [list]

Message-Id: <1231537682.29452.4.camel@twins>
Date:	Fri, 09 Jan 2009 22:48:02 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	Chris Adams <cmadams@...aay.net>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Fix leap second message hang

On Fri, 2009-01-09 at 14:31 -0600, Chris Adams wrote:
> Resending this outside the big long thread to make sure it gets added
> (it isn't critical right now but I don't want to forget it).

Best way to get stuff added is to CC the right people -- loose patches
get lost easily.

> The code to handle leap seconds printks an information message when the
> second is inserted or deleted.  It does this while holding xtime_lock.
> However, printk wakes up klogd, and in some cases, the scheduler tries
> to get the current kernel time, trying to get xtime_lock (which results
> in a deadlock).  This moved the printks outside of the lock.  It also
> adds a comment to not use printk while holding xtime_lock.

That should actually work these days, we don't actually do a direct wake
up anymore.

printk should work from all places, including holding rq->lock and
xtime_lock.
--
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/