From mboxrd@z Thu Jan  1 00:00:00 1970
From: Julien Grall <julien.grall@linaro.org>
Subject: Re: [PATCH v2 2/7] xen/arm: Implement hip04-d01 platform
Date: Tue, 04 Nov 2014 14:23:49 +0000
Message-ID: <5458E175.40409@linaro.org>
References: <1415033196-30529-1-git-send-email-frediano.ziglio@huawei.com>
	<1415033196-30529-3-git-send-email-frediano.ziglio@huawei.com>
	<5458D2C5.7050900@linaro.org>
	<B944B469BF5302468AC6EB05E56CC70D17B11C@lhreml509-mbb>
	<5458DCC9.9090406@linaro.org>
	<B944B469BF5302468AC6EB05E56CC70D17B168@lhreml509-mbb>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
In-Reply-To: <B944B469BF5302468AC6EB05E56CC70D17B168@lhreml509-mbb>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Frediano Ziglio <frediano.ziglio@huawei.com>, Ian Campbell <ian.campbell@citrix.com>, Stefano Stabellini <stefano.stabellini@citrix.com>, Tim Deegan <tim@xen.org>
Cc: Zoltan Kiss <zoltan.kiss@huawei.com>, "xen-devel@lists.xen.org" <xen-devel@lists.xen.org>
List-Id: xen-devel@lists.xenproject.org

On 11/04/2014 02:17 PM, Frediano Ziglio wrote:
>> If you really want to keep the *p = NULL. This could be simplify into:
>>
>> hip04_iounmap(....)
>> {
>>    iounmap(*p);
>>    *p = NULL;
>> }
>>
>> This is because iounmap takes care of NULL pointer.
>>
> 
> Are you sure? I looked at code and is not a simple vm_free call, it does some mapping even if address is NULL.

Yes, vm_size(va) will return 0 and destroy_xen_mappings won't unmap
anything because start == end.

I agree that an explicit check in vunmap would be nice.

Regards,

-- 
Julien Grall