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Message-ID: <86802c440808070351m6400b290jb826d10407c7de77@mail.gmail.com>
Date: Thu, 7 Aug 2008 03:51:48 -0700
From: "Yinghai Lu" <yhlu.kernel@gmail.com>
To: "Alan Cox" <alan@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH 00/33] dyn_array and nr_irqs support v4
Cc: "Eric W. Biederman" <ebiederm@xmission.com>, "Ingo Molnar" <mingo@elte.hu>,
       "Thomas Gleixner" <tglx@linutronix.de>,
       "H. Peter Anvin" <hpa@zytor.com>,
       "Dhaval Giani" <dhaval@linux.vnet.ibm.com>,
       "Mike Travis" <travis@sgi.com>,
       "Andrew Morton" <akpm@linux-foundation.org>,
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On Thu, Aug 7, 2008 at 3:12 AM, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> On Wed, 06 Aug 2008 18:02:18 -0700
> ebiederm@xmission.com (Eric W. Biederman) wrote:
>
>> Alan Cox <alan@lxorguk.ukuu.org.uk> writes:
>>
>> > A lot of these are range checks so could be replaced by a single
>> > valid_irq(irq) test.
>>
>> Yes.  My first impression was that with NR_IRQS dead valid_irq could
>> easily become. #define valid_irq(irq) ((irq) != 0)
>
> Not really - there are lots of cases where we sanity check an IRQ passed
> from user space or module parameter configuration. So we do actually need
>
>        valid_irq(irq)          ((irq) > 0 && (irq) < nr_irqs)
>
> [or relevant per arch alternatives]

#ifndef CONFIG_HAVE_SPARSE_IRQ
#define   valid_irq(irq)          ((irq) > 0 && (irq) < nr_irqs)
#else
#define   valid_irq(irq)          ((irq) > 0)

anyway why 0 is invalid instead of -1U...?

YH


#endif