linux-kernel - Re: [PATCH v1] x86/irq: handle chained interrupts during IRQ migration

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20120530025555.GC11445@linux-sh.org>
Date:	Wed, 30 May 2012 11:55:56 +0900
From:	Paul Mundt <lethal@...ux-sh.org>
To:	Sundar Iyer <sundar.iyer@...el.com>
Cc:	tglx@...utronix.de, linux-kernel@...r.kernel.org,
	arjan.van.de.ven@...el.com, german.monroy@...el.com
Subject: Re: [PATCH v1] x86/irq: handle chained interrupts during IRQ
 migration

On Tue, May 29, 2012 at 07:10:08PM +0530, Sundar Iyer wrote:
> diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
> index 2d921b3..7880722 100644
> --- a/include/linux/irqdesc.h
> +++ b/include/linux/irqdesc.h
> @@ -120,6 +120,16 @@ static inline int irq_has_action(unsigned int irq)
>  	return desc->action != NULL;
>  }
>  
> +/*
> + * Test to see if the IRQ is chained; it would not be requested and hence
> + * _IRQ_NOREQUEST would be set
> + */
> +static inline int irq_is_chained(unsigned int irq)
> +{
> +	struct irq_desc *desc = irq_to_desc(irq);
> +	return !(desc->status_use_accessors & IRQ_NOREQUEST);
> +}
> +

This approach looks highly suspect. There are many non-chained cases that
are also NOREQUEST. Chained IRQs are at the very least NOREQUEST,
NOPROBE, and NOTHREAD. You could test a mask of those and at least have a
vague change of not catching other unrelated IRQs. It would still be a
hack though, given that none of those status flags in and of themselves
require an IRQ to be chained.
--
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/