From mboxrd@z Thu Jan  1 00:00:00 1970
From: Julien Grall <julien.grall@linaro.org>
Subject: Re: [PATCH v4 18/18] xen/arm: IRQ: Handle multiple
	action per IRQ
Date: Wed, 23 Apr 2014 16:28:20 +0100
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To: Ian Campbell <Ian.Campbell@citrix.com>
Cc: xen-devel@lists.xenproject.org, Keir Fraser <keir@xen.org>, tim@xen.org, Jan Beulich <jbeulich@suse.com>, stefano.stabellini@citrix.com
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On 04/23/2014 04:16 PM, Ian Campbell wrote:
> On Wed, 2014-04-23 at 15:56 +0100, Julien Grall wrote:
>>>> +        do
>>>> +        {
>>>> +            action->handler(irq, action->dev_id, regs);
>>>> +            action = action->next;
>>>> +        } while ( action );
>>>
>>> What happens if action is freed and recycled in the midst of this loop?
>>
>> Nothing, the action won't be free until IRQ_INPROGRESS is set (see do ..
>> while at the end of release_irq).
> 
> BY that logic wasn't the version which used the list macros also safe
> then?

No because we had to modify two pointers (next and prev). Here as we
modify only one pointer, do_IRQ may or may not call action for a last time.

-- 
Julien Grall