linux-kernel - Re: [Patch Part2 v4 01/31] irqdomain: Introduce new interfaces to support hierarchy irqdomains

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.2.11.1411060044100.24960@nanos>
Date:	Thu, 6 Nov 2014 00:48:41 +0100 (CET)
From:	Thomas Gleixner <tglx@...utronix.de>
To:	Jiang Liu <jiang.liu@...ux.intel.com>
cc:	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Randy Dunlap <rdunlap@...radead.org>,
	Yinghai Lu <yinghai@...nel.org>,
	Borislav Petkov <bp@...en8.de>,
	Grant Likely <grant.likely@...aro.org>,
	Marc Zyngier <marc.zyngier@....com>,
	Yingjoe Chen <yingjoe.chen@...iatek.com>,
	Jonathan Corbet <corbet@....net>,
	Matthias Brugger <matthias.bgg@...il.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Tony Luck <tony.luck@...el.com>,
	Joerg Roedel <joro@...tes.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	x86@...nel.org, linux-kernel@...r.kernel.org,
	linux-pci@...r.kernel.org, linux-acpi@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-doc@...r.kernel.org
Subject: Re: [Patch Part2 v4 01/31] irqdomain: Introduce new interfaces to
 support hierarchy irqdomains

On Tue, 4 Nov 2014, Jiang Liu wrote:
>  /* Number of irqs reserved for a legacy isa controller */
>  #define NUM_ISA_INTERRUPTS	16
> @@ -64,6 +66,16 @@ struct irq_domain_ops {
>  	int (*xlate)(struct irq_domain *d, struct device_node *node,
>  		     const u32 *intspec, unsigned int intsize,
>  		     unsigned long *out_hwirq, unsigned int *out_type);
> +
> +#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
> +	/* extended V2 interfaces to support hierarchy irq_domains */
> +	int (*alloc)(struct irq_domain *d, unsigned int virq,
> +		     unsigned int nr_irqs, void *arg);
> +	void (*free)(struct irq_domain *d, unsigned int virq,
> +		     unsigned int nr_irqs);
> +	int (*activate)(struct irq_domain *d, struct irq_data *irq_data);
> +	int (*deactivate)(struct irq_domain *d, struct irq_data *irq_data);

Why do we have a return value here? Especially the deactivate one
makes no sense at all.

> +extern int irq_domain_activate_irq(struct irq_data *irq_data);
> +extern int irq_domain_deactivate_irq(struct irq_data *irq_data);

And here.

> @@ -178,6 +179,7 @@ int irq_startup(struct irq_desc *desc, bool resend)
>  	irq_state_clr_disabled(desc);
>  	desc->depth = 0;
>  
> +	irq_domain_activate_irq(&desc->irq_data);

We do not check it and we cannot do here AFAICT.

>  	if (desc->irq_data.chip->irq_startup) {
>  		ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
>  		irq_state_clr_masked(desc);
> @@ -199,6 +201,7 @@ void irq_shutdown(struct irq_desc *desc)
>  		desc->irq_data.chip->irq_disable(&desc->irq_data);
>  	else
>  		desc->irq_data.chip->irq_mask(&desc->irq_data);
> +	irq_domain_deactivate_irq(&desc->irq_data);

Ditto.

So the return value for irq_domain_deactivate_irq() is silly to begin
with, but also the return value for irq_domain_activate_irq() does not
really make sense. We've allocated the resources for the interrupt
already down the hierarchy chain. So there is no reason why the actual
activation should fail.

Thanks,

	tglx
--
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/