linux-kernel - Re: [PATCH] genirq: Skip chained interrupt trigger configuration if type is IRQ_TYPE

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: <alpine.DEB.2.20.1609191127500.5618@nanos>
Date:   Mon, 19 Sep 2016 11:28:42 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Marc Zyngier <marc.zyngier@....com>
cc:     linux-kernel@...r.kernel.org,
        Geert Uytterhoeven <geert@...ux-m68k.org>
Subject: Re: [PATCH] genirq: Skip chained interrupt trigger configuration if
 type is IRQ_TYPE_NONE

On Mon, 19 Sep 2016, Marc Zyngier wrote:
> On 19/09/16 10:12, Thomas Gleixner wrote:
> > On Mon, 19 Sep 2016, Marc Zyngier wrote:
> >>  	if (handle != handle_bad_irq && is_chained) {
> >> +		unsigned int type = irqd_get_trigger_type(&desc->irq_data);
> >> +
> >>  		/*
> >>  		 * We're about to start this interrupt immediately,
> >>  		 * hence the need to set the trigger configuration.
> >> @@ -828,8 +830,10 @@ __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle,
> >>  		 * chained interrupt. Reset it immediately because we
> >>  		 * do know better.
> >>  		 */
> >> -		__irq_set_trigger(desc, irqd_get_trigger_type(&desc->irq_data));
> >> -		desc->handle_irq = handle;
> >> +		if (type != IRQ_TYPE_NONE) {
> >> +			__irq_set_trigger(desc, type);
> >> +			desc->handle_irq = handle;
> > 
> > Are you really sure that the handler should only be set when the trigger
> > type is != NONE? I seriously doubt that this is correct.
> 
> The handler has already been set outside of if() statement (at line
> 819). Here, we only set it again if we've actually called
> __irq_set_trigger() which could have changed it to something that takes
> the type into account (handle_level_irq or handle_edge_irq, for example).

Ah. I'll add a comment...