From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeremy Fitzhardinge <jeremy@goop.org>
Subject: Re: Re: [PATCH] xen: fix off-by-one error
	in	find_unbound_irq
Date: Fri, 26 Feb 2010 12:13:38 -0800
Message-ID: <4B882B72.3000207@goop.org>
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	<1267183329.11737.12225.camel@zakaz.uk.xensource.com>
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To: Ian Campbell <Ian.Campbell@citrix.com>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>, Jeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
List-Id: xen-devel@lists.xenproject.org

On 02/26/2010 03:22 AM, Ian Campbell wrote:
> BTW, this is against xen/master, the original patch isn't in xen/next.
>    

Looks like it came from the pcifront branch which isn't in xen/next yet.

     J

> On Fri, 2010-02-26 at 10:59 +0000, Ian Campbell wrote:
>    
>> e459de95 "Find an unbound irq number in reverse order (high to low)" introduced
>> an off by one error which would cause repeated allocations of the nr_irq'th IRQ
>> if there are no spare interrupts (i.e. get_nr_hw_irqs() == nr_irqs).
>>
>> Signed-off-by: Ian Campbell<ian.campbell@citrix.com>
>> Cc: Konrad Rzeszutek Wilk<konrad.wilk@oracle.com>
>> Cc: Jeremy Fitzhardinge<jeremy.fitzhardinge@citrix.com>
>> ---
>>   drivers/xen/events.c |    2 +-
>>   1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/xen/events.c b/drivers/xen/events.c
>> index 99f2b2a..5c64e1d 100644
>> --- a/drivers/xen/events.c
>> +++ b/drivers/xen/events.c
>> @@ -377,7 +377,7 @@ static int find_unbound_irq(void)
>>   		if (irq_info[irq].type == IRQT_UNBOUND)
>>   			break;
>>
>> -	if (irq == start || irq == nr_irqs)
>> +	if (irq == start || irq == nr_irqs - 1)
>>   		panic("No available IRQ to bind to: increase nr_irqs!\n");
>>
>>   	desc = irq_to_desc_alloc_node(irq, 0);
>>      
>
>
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