From mboxrd@z Thu Jan  1 00:00:00 1970
From: Olivier MATZ <olivier.matz@6wind.com>
Subject: Re: test-pmd: Free of address-of expression
Date: Tue, 17 May 2016 10:16:23 +0200
Message-ID: <573AD357.40602@6wind.com>
References: <158888A50F43E34AAE179517F56C97455A52C6@IRSMSX103.ger.corp.intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: quoted-printable
Cc: "dev@dpdk.org" <dev@dpdk.org>
To: "Mrozowicz, SlawomirX" <slawomirx.mrozowicz@intel.com>
Return-path: <dev-bounces@dpdk.org>
Received: from proxy.6wind.com (host.76.145.23.62.rev.coltfrance.com
 [62.23.145.76]) by dpdk.org (Postfix) with ESMTP id 6673C691A
 for <dev@dpdk.org>; Tue, 17 May 2016 10:16:36 +0200 (CEST)
In-Reply-To: <158888A50F43E34AAE179517F56C97455A52C6@IRSMSX103.ger.corp.intel.com>
List-Id: patches and discussions about DPDK <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

Hi,


On 05/17/2016 09:55 AM, Mrozowicz, SlawomirX wrote:
> Hi,
>
> Noticed is that in the file:
>
> app/test-pmd/mempool.c
>
> using of the function munmap() could cause a problem.
>
> Coverity static code analyzer provide error (CID 13184) in line 158:
>
> munmap frees incorrect pointer uv.
>
> I noticed information on the net:
>
> https://www.ibm.com/support/knowledgecenter/SSLTBW_2.1.0/com.ibm.zos.v2=
r1.bpxbd00/mumap.htm
>
> =93If addr is not the address of a mapping established by a prior call =
to
> mmap(), the behavior is undefined=94
>
> I have analyzed the code and I have done some test with gcc.
>
> It seems that it is possible to free subrange of the mapping memory.
>
> In the mempool.c code the address is calculated independently.
>
> Anyway in my opinion the address variable uv is calculated correctly.
>
> So we should classify this issue as a  False Positive.
>
> Please accept the conclusion.

This file (app/test-pmd/mempool_anon.c) will be removed soon.
Please see http://dpdk.org/dev/patchwork/patch/12067/

So I think we can ignore this alert, as the new code does not
have the same issue.

Regards,
Olivier