From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1752602AbdBMLNU (ORCPT <rfc822;w@1wt.eu>);
        Mon, 13 Feb 2017 06:13:20 -0500
Received: from mout.web.de ([212.227.15.4]:63736 "EHLO mout.web.de"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1752043AbdBMLNS (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 13 Feb 2017 06:13:18 -0500
Subject: Re: IB/hfi1: Use memdup_user() rather than duplicating its
 implementation in hfi1_user_sdma_process_request()
To: Dan Carpenter <dan.carpenter@oracle.com>, linux-rdma@vger.kernel.org
References: <8a997282-09c7-0f9f-645e-d7c6e8c79e67@users.sourceforge.net>
 <b19e44b3-601f-c642-b8d3-12c000511ce2@users.sourceforge.net>
 <477c8499-93ad-253d-aa2b-8f209ecfad62@intel.com>
 <20170213105350.GA4108@mwanda>
Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>,
        Doug Ledford <dledford@redhat.com>,
        Hal Rosenstock <hal.rosenstock@gmail.com>,
        Mike Marciniszyn <mike.marciniszyn@intel.com>,
        Sean Hefty <sean.hefty@intel.com>, LKML <linux-kernel@vger.kernel.org>,
        kernel-janitors@vger.kernel.org
From: SF Markus Elfring <elfring@users.sourceforge.net>
Message-ID: <4094dc04-bb2c-a74e-8d4d-8879ac4e7761@users.sourceforge.net>
Date: Mon, 13 Feb 2017 12:12:51 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.7.1
MIME-Version: 1.0
In-Reply-To: <20170213105350.GA4108@mwanda>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 8bit
X-Provags-ID: V03:K0:FNLVd9KFl+3cM/MN/e5GcVTHkWwzp6kjQhyFelNZdkAp2DjXruf
 DE75EZ4my/v3nTAi6h2aJBwa56pqaXNOBBtDaVSQcji7/67pGx8Y018fmiqM8wT0nXKKUQ2
 7S1C7/jC3i5Kz37ZuPcGuCvVb8xSBr2jWD2StXgeK0VCo29+SPTUrxNjoHaLg9mygscnbyu
 NnBrN1+VldRXACA4f6uyA==
X-UI-Out-Filterresults: notjunk:1;V01:K0:r4Mg6jv1isI=:O4SZwD/l9s0K7J5RoXQOIn
 GYO7aoR9/ZS4cAKl+o4ZpA+O/1dPLemBkdhhIdF8/SHhmuT6ApEBIkk4hu6fkUKjy0ZBMUdfR
 gZ7uGYFPqbpn7PBi7zJY7H40EWX11Tb8XoOX5YVMsMvcmxheMkxyMDqk4A1gfg8ls6CA+xRGq
 89amqAk6AMAZyMgbeLNDbWOTQjtuGsvHQgD/LXvAyTOhOBFELQRzKKOicYJho9X9nJ65hspiX
 MU9mYQRqgBZKJBSopcr/klAWTVkIsbQHK6M9axmwdJpjbpmqFOCYWLdvhbItJayQH8qgPtlG5
 0uVvJyguR6HLRigqmoGhcA82AmCf3+FrrK+/ybLQttNMJsXMkrQIO0zd0RvC3ALMQNzmtiRMf
 G3LGuTjQTrJLWqWk+KyFuOV2HOf1T0O08/v1USH0DZUyAmPKXXk2bie74QA/oF9PM2Bevd3gM
 u+qYluggwxjmaNuP8xnA6O2SijLpqespsI8TZcJD4aXge2xSYXYFbHDnkd3KbzQ5aTlM4aFSk
 6zKpeXvA1//oMUM1o9Heepre9hrFHhtdGjm73BHh4k5aOmSt4tjGzqyYPhL/pYzGUq95upDNZ
 pruHBBlV6YaEURdlOQQvMhGziX7WYhM1BBb7c+Udrq/q779FgHCPYSwex08M1QMxu1WE37znK
 q38MQSfZ50VQwsYzfg1k7/be5Yd1Uy0gDN3bAdFBeAmpc1nPgB3dKBZGKU+z2Y66HU6OQZ/sT
 zeXh70po5x7/eZYjXeDP4xs4eXznOY/K3b+h1rS2mftL+O7WjNygsmVgqSbwuP2bcUQgw1Sp7
 q+BYeHd
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

>> Thanks for the patch, but this one is already taken care of along
>> with other similar uses of kmalloc/copy:
>>
>> http://marc.info/?l=linux-rdma&m=148656088729538&w=2
>>
> 
> Michael's patch doesn't change user_sdma_free_request() so it introduces
> a kfreeing an error pointer bug.

Did you notice that another local variable “tmp” was introduced in the update step
“[PATCH 27/27] IB/hfi1: Code reuse with memdup_copy” so that
the mentioned function will usually get a null pointer after a failure there?

Regards,
Markus