linux-kernel - Re: lockdep and threaded IRQs

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

Date:	Sat, 28 Feb 2009 12:20:08 +0100
From:	Stefan Richter <stefanr@...6.in-berlin.de>
To:	David Brownell <david-b@...bell.net>
CC:	me@...ipebalbi.com, Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org, linux-input@...r.kernel.org,
	felipe.balbi@...ia.com, dmitry.torokhov@...il.com,
	sameo@...nedhand.com, Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: lockdep and threaded IRQs

David Brownell wrote:
> The other is that Linux needs real support for threaded
> interrupts.  Almost every I2C (or SPI) device that raises
> an IRQ needs its IRQ handler to run in a thread, and most
> of them have the same type of workqueue-based hack to
> get such a thread.  (Some others have bugs instead...)

Since when is having an IRQ handler scheduling a workqueue job a hack?
In kernels whose IRQ handlers don't sleep, we don't pretend that they
could; instead we defer sleeping work to a context which can sleep.

Or from another angle:  If a driver requires a kernel with sleeping IRQ
handlers, why submit it for inclusion into a kernel which does not
provide nonatomic context to IRQ handlers?
-- 
Stefan Richter
-=====-==--= --=- ===--
http://arcgraph.de/sr/
--
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/