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To: "Mrozowicz, SlawomirX" <slawomirx.mrozowicz@intel.com>
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From: Olivier MATZ <olivier.matz@6wind.com>
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Date: Tue, 17 May 2016 10:16:23 +0200
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Subject: Re: [dpdk-dev] test-pmd: Free of address-of expression
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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.v2r1.bpxbd00/mumap.htm
>
> “If addr is not the address of a mapping established by a prior call to
> mmap(), the behavior is undefined”
>
> 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