netdev - Re: [PCNET32] Lock solid with netconsole

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: <20070528220021.GB4927@electric-eye.fr.zoreil.com>
Date:	Tue, 29 May 2007 00:00:21 +0200
From:	Francois Romieu <romieu@...zoreil.com>
To:	Thomas Bogendoerfer <tsbogend@...ha.franken.de>
Cc:	Lennart Sorensen <lsorense@...lub.uwaterloo.ca>,
	Emmanuel Fust? <emmanuel.fuste@...oste.net>,
	pcnet32 <pcnet32@...izon.net>, netdev <netdev@...r.kernel.org>
Subject: Re: [PCNET32] Lock solid with netconsole

Thomas Bogendoerfer <tsbogend@...ha.franken.de> :
[...]
> for normal interrupt delivery it doesn't matter, because there shouldn't
> be any more interrupts coming in at that point. But netconsole uses
> pcnet32_interrupt for polling the chip. So if during service of a
> a real interrupt a polled pcnet32_interrupt call is done, the machine
> will deadlock.

Even if the driver-agnostic part of the irq processing can be interrupted
locally, the irq handlers are run sequentially on a given cpu. It does not
leave a lot of room for a deadlock-prone printk().

It _can_ happen but I'd prefer to pinpoint a specific candidate path
where it would have happened.

-- 
Ueimor
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html