linux-kernel - [RFC][PATCH 0/7] improve printk reliability

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-next>] [day] [month] [year] [list]

Message-Id: <20111221105739.798864333@chello.nl>
Date:	Wed, 21 Dec 2011 11:57:39 +0100
From:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
To:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Ted Ts'o <tytso@....edu>, Greg KH <greg@...ah.com>,
	Ingo Molnar <mingo@...e.hu>,
	Thomas Gleixner <tglx@...utronix.de>, akpm@...ux-foundation.org
Cc:	linux-kernel <linux-kernel@...r.kernel.org>
Subject: [RFC][PATCH 0/7] improve printk reliability

Hi,

So these are my current efforts to make my own console output more
reliable. I've hit every deadlock described in this series and a few
more.

With these patches applied I can printk() and WARN() from inside 
scheduler context and not have my machine deadlock, even without the 
aid of early_printk().

While I'll go an remove the sole printk() I found in the scheduler
so that we don't have to rely on the console doing this, it is good
to have a reliable console that can do this.

As it stands some of the patches, the semaphore one in particular,
are really too ugly to live so I won't push those but wanted to share
anyway.

Debugging this was 'fun', and I really hope to not have to do it
again :-)

--
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/