linux-kernel - Re: [PATCH PREEMPT_RT]: On AT91 ARM: GPIO Interrupt handling can/will stall forever

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]

Message-Id: <1196282672.27964.32.camel@imap.mvista.com>
Date:	Wed, 28 Nov 2007 12:44:31 -0800
From:	Daniel Walker <dwalker@...sta.com>
To:	Steven Rostedt <rostedt@...dmis.org>
Cc:	Russell King - ARM Linux <linux@....linux.org.uk>,
	Remy Bohmer <linux@...mer.net>,
	RT <linux-rt-users@...r.kernel.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	ARM Linux Mailing List 
	<linux-arm-kernel@...ts.arm.linux.org.uk>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...e.hu>
Subject: Re: [PATCH PREEMPT_RT]: On AT91 ARM: GPIO Interrupt handling
	can/will stall forever

On Wed, 2007-11-28 at 15:16 -0500, Steven Rostedt wrote:

> 
> This could also simply be unique to the interrupt threads (only in RT). So
> perhaps the patch is OK.
> 
> Remy, sorry about this round-a-bout. But I don't have any of the hardware
> that this affects, and I'm just being cautious.

Ignoring the ARM side of things for a sec, handle_simple_irq() will
mask() the interrupt in the special case that an interrupt is already in
the processes of being handled.. handle_simple_irq() also unmasks when
it finishes handling an interrupt (something real time adds for some
reason) ..

In terms of threading the irq everything is the same except there is no
unmask() call when the thread finishes .. 

Daniel

-
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/