From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90DD7CDB47F for ; Wed, 11 Oct 2023 19:22:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347015AbjJKTV7 (ORCPT ); Wed, 11 Oct 2023 15:21:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347010AbjJKTV5 (ORCPT ); Wed, 11 Oct 2023 15:21:57 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B29BEA4 for ; Wed, 11 Oct 2023 12:21:56 -0700 (PDT) Received: from pps.filterd (m0356517.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 39BJHVFe023054; Wed, 11 Oct 2023 19:21:49 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : references : from : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=h+v1IOG/jmNDJTRhW9IuaIpAohQ4Dp4Gm4L7ijlhMLQ=; b=ZAVIne1qZ+e/BJWw3nQbQntJdSvHIqv8FsfTOZKEpWPJWycCaukcZEPfpvLJxvrUbDKc f66Q7wzKU4Ump9IGeuVXKLTOQ6LL0r9pDu/Cp1apsA5qbe4BjNGFOx1AdSNQP176afU0 1Rr8k+w4OGwXRnr3+cC3nBXCTpJXduexv/99lbWWjqMpuQFyf6+p2jDOIawNd1IZlE59 9h5andyJSpX2GDYbzmRDmPj7nGQLc3uUboNeqQkYdIntlv+kTwEpFkb/EzPSFLORYwFJ S4XPbCTcMFGFQ+qyNriI1FLZMIGDmz01mGAC2uS4TanZ7hQSHSezztvV2/xC2e40sGpP KA== Received: from ppma12.dal12v.mail.ibm.com (dc.9e.1632.ip4.static.sl-reverse.com [50.22.158.220]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3tp1qx07nx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 11 Oct 2023 19:21:49 +0000 Received: from pps.filterd (ppma12.dal12v.mail.ibm.com [127.0.0.1]) by ppma12.dal12v.mail.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 39BI4bYK024465; Wed, 11 Oct 2023 19:21:48 GMT Received: from smtprelay05.dal12v.mail.ibm.com ([172.16.1.7]) by ppma12.dal12v.mail.ibm.com (PPS) with ESMTPS id 3tkhnstqgh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 11 Oct 2023 19:21:48 +0000 Received: from smtpav06.dal12v.mail.ibm.com (smtpav06.dal12v.mail.ibm.com [10.241.53.105]) by smtprelay05.dal12v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 39BJLmnE24773120 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 11 Oct 2023 19:21:48 GMT Received: from smtpav06.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3FB0158055; Wed, 11 Oct 2023 19:21:48 +0000 (GMT) Received: from smtpav06.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 161CB58043; Wed, 11 Oct 2023 19:21:48 +0000 (GMT) Received: from [9.61.37.205] (unknown [9.61.37.205]) by smtpav06.dal12v.mail.ibm.com (Postfix) with ESMTP; Wed, 11 Oct 2023 19:21:48 +0000 (GMT) Message-ID: <8a81172f-e920-88d2-41ec-f9ce90a0afc1@linux.ibm.com> Date: Wed, 11 Oct 2023 14:21:47 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [PATCH v3 2/2] fsi: sbefifo: Handle pending write command Content-Language: en-US To: Ninad Palsule , jk@ozlabs.org, joel@jms.id.au, alistair@popple.id.au, linux-fsi@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <20231010204348.2600242-1-ninad@linux.ibm.com> <20231010204348.2600242-3-ninad@linux.ibm.com> From: Eddie James In-Reply-To: <20231010204348.2600242-3-ninad@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: FOHvAE02bLqYh64MaygYn6MUziDIyB7G X-Proofpoint-GUID: FOHvAE02bLqYh64MaygYn6MUziDIyB7G X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.980,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-10-11_14,2023-10-11_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 phishscore=0 mlxscore=0 suspectscore=0 impostorscore=0 adultscore=0 spamscore=0 mlxlogscore=999 malwarescore=0 bulkscore=0 lowpriorityscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2309180000 definitions=main-2310110171 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/10/23 15:43, Ninad Palsule wrote: > If previous write command is still pending then free it first. > > As per the current kernel driver design, write operation prepares a > buffer for FSI write, the actual FSI write is performed on next read > operation. There is a possibility of memory leak if buggy application > sends two back to back writes or two parallel writes. Reviewed-by: Eddie James > > Signed-off-by: Ninad Palsule > --- > v3: > - Incorporated review comments by Eddie. > --- > drivers/fsi/fsi-sbefifo.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/fsi/fsi-sbefifo.c b/drivers/fsi/fsi-sbefifo.c > index a95b32461f8f3..1cc88a78e588a 100644 > --- a/drivers/fsi/fsi-sbefifo.c > +++ b/drivers/fsi/fsi-sbefifo.c > @@ -877,6 +877,13 @@ static ssize_t sbefifo_user_write(struct file *file, const char __user *buf, > > mutex_lock(&user->file_lock); > > + /* If previous write command is still pending then free it. It is safe > + * to do that because read cannot be in progress since we hold the > + * lock. > + */ > + if (user->pending_cmd) > + sbefifo_release_command(user); > + > /* Can we use the pre-allocate buffer ? If not, allocate */ > if (len <= PAGE_SIZE) > user->pending_cmd = user->cmd_page;