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[156.151.31.85]) by mx.google.com with ESMTPS id k12si35845014pgi.107.2019.04.11.11.40.14 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 11 Apr 2019 11:40:14 -0700 (PDT) Received-SPF: pass (google.com: domain of mike.kravetz@oracle.com designates 156.151.31.85 as permitted sender) client-ip=156.151.31.85; Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2018-07-02 header.b="C3RuE/4y"; spf=pass (google.com: domain of mike.kravetz@oracle.com designates 156.151.31.85 as permitted sender) smtp.mailfrom=mike.kravetz@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x3BIcft3103044; Thu, 11 Apr 2019 18:40:07 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=GB8LfO77Jy6JgNbe7pmliFg2YECUcEkjiuvkWQ7pqHo=; b=C3RuE/4yqybULo8qV1Vv7aydlTkpNoAfka9yhSfCHfvmWgjDsP0ilTAjnBJ+Ndm6CuBl lGZe7L47sq7tzdY3377JHsnBQQoDGDzZ3ZYkuUr3TCaK1UgxVaJVGoXk9tWrIUtns+k7 Ur/QPvOZ1vyqtTuIcVl2u1Pd1QDxG0WmzO9w4zSqi/+Wjd2ZuMBPKYfwykto6ZIt8apS G5Bc4LL4tyqybrdB4Zu10vO94jjUigFpPhL9E6T0/QwA0yBqqhlYcgkYP11VQdZFbne0 3HxQ3gF32+CI4WQVOKN7psF4TAyWzdpaQYaKZPRRSHGbz2cUfVjGe2kFTDq7ILYTIUMB VA== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2120.oracle.com with ESMTP id 2rpmrqjku5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 11 Apr 2019 18:40:06 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x3BIdffI194833; Thu, 11 Apr 2019 18:40:06 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3030.oracle.com with ESMTP id 2rt9upsbwk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 11 Apr 2019 18:40:05 +0000 Received: from abhmp0001.oracle.com (abhmp0001.oracle.com [141.146.116.7]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x3BIe4fm013938; Thu, 11 Apr 2019 18:40:04 GMT Received: from [192.168.1.222] (/50.38.38.67) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 11 Apr 2019 11:40:03 -0700 Subject: Re: [PATCH v2] hugetlbfs: fix protential null pointer dereference To: Michal Hocko Cc: Yufen Yu , linux-mm@kvack.org, kirill.shutemov@linux.intel.com, n-horiguchi@ah.jp.nec.com References: <20190411035318.32976-1-yuyufen@huawei.com> <20190411081900.GP10383@dhcp22.suse.cz> <20190411182220.GD10383@dhcp22.suse.cz> From: Mike Kravetz Message-ID: Date: Thu, 11 Apr 2019 11:40:02 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190411182220.GD10383@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9224 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904110124 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9224 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904110124 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 4/11/19 11:22 AM, Michal Hocko wrote: > On Thu 11-04-19 09:52:45, Mike Kravetz wrote: >> Or, do you think that is too much? >> Ideally, that comment should have been added as part of 58b6e5e8f1ad >> ("hugetlbfs: fix memory leak for resv_map") as it could cause one to wonder >> if resv_map could be NULL. > > I would much rather explain a comment explaining _when_ inode_resv_map > might return NULL than add checks just to be sure. You are right. That would make more sense. It has been a while since I looked into that code and unfortunately I did not save notes. I'll do some research to come up with an appropriate explanation/comment. -- Mike Kravetz