linux-kernel - Re: [patch] forcedeth: fix locking bug 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]

Date:	Fri, 21 Mar 2008 17:32:54 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Jeff Garzik <jgarzik@...ox.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [patch] forcedeth: fix locking bug with netconsole


* Jeff Garzik <jgarzik@...ox.com> wrote:

> Ingo Molnar wrote:
>> Subject: forcedeth: fix locking bug with netconsole
>> From: Ingo Molnar <mingo@...e.hu>
>>
>> while using netconsole on forcedeth, lockdep noticed the following
>> locking bug:
> [...]
>> the fix is to disable/restore irqs instead of disable/enable.
>
> So we make _the_ TX fast path slower, to accomodate a path that is 
> rarely executed?

no strong opinion but a single PCI mmio access far outweighs any flags 
save/restore, so i'd not fight about something like that. I've never 
seen flags save/restore costs show up in NMI-driven profiles that had 
networking load.

	Ingo
--
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/