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: <20110607090500.4f060390@archvile>
Date:	Tue, 7 Jun 2011 09:05:00 +0200
From:	David Jander <david.jander@...tonic.nl>
To:	Thomas Gleixner <tglx@...utronix.de>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Why does handle_simple_irq() require IRQ's to be disabled?


Hi Thomas,

On Mon, 6 Jun 2011 18:18:41 +0200 (CEST)
Thomas Gleixner <tglx@...utronix.de> wrote:

> On Mon, 6 Jun 2011, David Jander wrote:
> > 
> > Hi,
> > 
> > I am trying to implement/fix interrupt controller functionality in
> > gpio/pca953x.c, and for some reason which I don't understand, I need to
> > disable interrupts with local_irq_disable() before calling
> > generic_handle_irq(). This does not seem right.
> > If I follow the code of handle_simple_irq(), the handler function setup for
> > this IRQ, I get to handle_irq_event_percpu(), which has a
> > WARN_ONCE(!irqs_disabled(),...
> > This WARN is triggered, since nobody explicitly disables interrupts. Why?
> >  
> > generic_hanlde_irq() is called from a threaded interrupt handler of the
> > parent of this interrupt controller, and calling local_irq_disable() here
> > seems like a crime. What am I doing wrong?
> 
> handle_nested_irq() is your friend.

Thanks! This worked without disabling IRQ's.
One last question, though:

I set up the handler using irq_set_chip_and_handler(irq, ...,
handle_simple_irq);
>From the interrupt thread, I call handle_nested_irq(). Is it OK, that in this
case, the defined handler function (handle_simple_irq) is not used? Does this
still make sense? Wouldn't calling just irq_set_chip() be enough here (it
seems to work correctly)?

Best regards,

-- 
David Jander
Protonic Holland.
--
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/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ