Received: by 2002:a25:1985:0:0:0:0:0 with SMTP id 127csp755851ybz;
        Wed, 15 Apr 2020 18:15:39 -0700 (PDT)
X-Google-Smtp-Source: APiQypIjRTbYiRj4BjHyPSHFvwmCXM6+WKTwaga/qBL5Mycmg9tX/10dPE2Cy1t6/8eKB9JHAgPV
X-Received: by 2002:aa7:d14e:: with SMTP id r14mr24540772edo.200.1586999739365;
        Wed, 15 Apr 2020 18:15:39 -0700 (PDT)
ARC-Seal: i=1; a=rsa-sha256; t=1586999739; cv=none;
        d=google.com; s=arc-20160816;
        b=KFVLIuez4+sxK95JhakveQQC9EGOIsJBWJHKV+sNukTNogMi8ej7GjxySDF+BpF6zi
         XlVAM/7On2JJeZYZgpxVPxbfVOIk0G8vJg3d89n3vqB/PVH2fVCpfo2PgU5hWx5XdOud
         6+BjEIFmiQKpJNjd6VgkfHBVMszP+8Nf0QNRqNM4inprMcw6AHCI65KUoJvZqudNE7GQ
         2jKDAAjrI6TKSFJ1ct+zJ04FTGIFhlDzDXeYqDaUWwA6k0KFextbYu/5aHL5T0p62+90
         A7OSey+o90o4R5aivNR1dWz5PoiiwP7YoZlIEGy/vbUF/e6b5tZT34Hrx3h82kOiZDoK
         2MbA==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816;
        h=list-id:precedence:sender:dkim-signature:content-language
         :content-transfer-encoding:in-reply-to:mime-version:user-agent:date
         :message-id:references:cc:to:from:subject;
        bh=bWNDLEJ+w5gMa9E53iRd9p5tkU2TJO/QPK6MrfCvJ3s=;
        b=JSgi/trYQtgzNjxyynod5b7eIG9Az1aYzxoosxU56hXS+GlZHvJJC4fU/hu2IbTK2U
         2RDlUrMoLQI7lIooixISeb4V9QFiuEkZiZyn8OdFg7axcPJucgq5r1xh+HfLv3IS5MII
         jdcUsD7aSvegCo93Icblt7FB3MWvhQ1WhK4eIE6bZ2fXrU2vpfW1npfBRUha1h2OX2jO
         G+3iWOk0bC8HBq/TeZF96lOFFyMBT9Z9ny6Eap+SHLRSwTCVA8ckTJNkhoQnjJimBWXs
         N8KSyTqB8u6iiQpAOwdDeEmoSAblTW0K/bTnaI+raRSyRx7Jty/HpHgzah2F34L/rEJk
         vbEQ==
ARC-Authentication-Results: i=1; mx.google.com;
       dkim=pass header.i=@nvidia.com header.s=n1 header.b=YflXSRWW;
       spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org;
       dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18])
        by mx.google.com with ESMTP id y23si11628759ejc.425.2020.04.15.18.15.16;
        Wed, 15 Apr 2020 18:15:39 -0700 (PDT)
Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Authentication-Results: mx.google.com;
       dkim=pass header.i=@nvidia.com header.s=n1 header.b=YflXSRWW;
       spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org;
       dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S2388251AbgDOXIZ (ORCPT <rfc822;kerneldev.sdk@gmail.com>
        + 99 others); Wed, 15 Apr 2020 19:08:25 -0400
Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:6648 "EHLO
        hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S2387913AbgDOXIU (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Wed, 15 Apr 2020 19:08:20 -0400
Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA)
        id <B5e9793750000>; Wed, 15 Apr 2020 16:06:29 -0700
Received: from hqmail.nvidia.com ([172.20.161.6])
  by hqpgpgate102.nvidia.com (PGP Universal service);
  Wed, 15 Apr 2020 16:08:19 -0700
X-PGP-Universal: processed;
        by hqpgpgate102.nvidia.com on Wed, 15 Apr 2020 16:08:19 -0700
Received: from DRHQMAIL107.nvidia.com (10.27.9.16) by HQMAIL109.nvidia.com
 (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 15 Apr
 2020 23:08:19 +0000
Received: from [10.2.171.241] (10.124.1.5) by DRHQMAIL107.nvidia.com
 (10.27.9.16) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 15 Apr
 2020 23:08:18 +0000
Subject: Re: [RFC PATCH v7 6/9] media: tegra: Add Tegra210 Video input driver
From:   Sowjanya Komatineni <skomatineni@nvidia.com>
To:     Dmitry Osipenko <digetx@gmail.com>
CC:     <thierry.reding@gmail.com>, <jonathanh@nvidia.com>,
        <frankc@nvidia.com>, <hverkuil@xs4all.nl>, <sakari.ailus@iki.fi>,
        <helen.koike@collabora.com>, <sboyd@kernel.org>,
        <linux-media@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-clk@vger.kernel.org>, <linux-tegra@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <1586919463-30542-1-git-send-email-skomatineni@nvidia.com>
 <1586919463-30542-7-git-send-email-skomatineni@nvidia.com>
 <4118112f-f865-5460-6319-d71271fd78d1@gmail.com>
 <a69a8b34-beea-3ad0-e08e-f7df8b9e7047@nvidia.com>
 <6afa951e-d904-f3c0-053f-82a02fb18979@nvidia.com>
 <b1c78827-13ea-0c94-a575-97b5afc0ede1@nvidia.com>
 <5954a7e1-910e-7f48-56d3-e671b56ead74@nvidia.com>
 <d6a9e07c-474a-a076-8313-32f5f4ca8d64@nvidia.com>
 <786949a9-8507-7723-f29b-b91a216bfd28@nvidia.com>
 <f831408b-bbf4-3047-20e3-5bebfa9fc1ad@gmail.com>
 <2ad9352f-cb65-1643-e540-a21f9c570266@nvidia.com>
Message-ID: <31924f2b-8f85-d28d-4f5d-4e232bff94a5@nvidia.com>
Date:   Wed, 15 Apr 2020 16:08:16 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.9.0
MIME-Version: 1.0
In-Reply-To: <2ad9352f-cb65-1643-e540-a21f9c570266@nvidia.com>
X-Originating-IP: [10.124.1.5]
X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To
 DRHQMAIL107.nvidia.com (10.27.9.16)
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Transfer-Encoding: quoted-printable
Content-Language: en-US
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1;
        t=1586991989; bh=bWNDLEJ+w5gMa9E53iRd9p5tkU2TJO/QPK6MrfCvJ3s=;
        h=X-PGP-Universal:Subject:From:To:CC:References:Message-ID:Date:
         User-Agent:MIME-Version:In-Reply-To:X-Originating-IP:
         X-ClientProxiedBy:Content-Type:Content-Transfer-Encoding:
         Content-Language;
        b=YflXSRWWbkvaMf+QCkVdC+sj2kwfrMlhXgM16P93X9oIuJcMLD05S2FUtqeEvceu9
         lcIrPxdMmiI70FtBalem7oudEhLsDryvGLUGnmWKzTPJHzfp58egM3kk98GyAsZxCB
         JdPhSNtQXe/3nWGJYxz/fS9KcqL9PsxYPnBr0AEUYyRDwyxpgwWU9y52lma4nwp6jE
         saedVvrZNUwFH3OvKPZ81sjYL+bYJquz07Ac7DP+X6RNDk9CTYbkj1LbWDx2UtsBUD
         TL8NJM11xdzplWo78CWedttg59n4TUMnSPjpU6OG4BAQFY0i/Mo5F231bu2q3OEYS/
         k7UdR+/KWUpTA==
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

With minor change of not using vi reference after=20
host1x_client_unregister and freeing vi during v4l2 device release works.

For csi, we can use devm_kzalloc for now untill we decide later if we=20
want to expose async subdev nodes during sensor support.

Will have this fix in v8 with a comment in vi_remove to make sure not to=20
use vi reference after host1x_client_unregister.

Will test more and will release v8 with above fix to allow direct host1x=20
client driver unbind.

Thanks

sowjanya


On 4/15/20 12:51 PM, Sowjanya Komatineni wrote:
>
> On 4/15/20 12:21 PM, Dmitry Osipenko wrote:
>> External email: Use caution opening links or attachments
>>
>>
>> 15.04.2020 21:53, Sowjanya Komatineni =D0=BF=D0=B8=D1=88=D0=B5=D1=82:
>> ...
>>>>>>>>> Have you tried to test this driver under KASAN? I suspect that
>>>>>>>>> you just
>>>>>>>>> masked the problem, instead of fixing it.
>>> Tested with kmemleak scan and did not see any memory leaks
>> You should get use-after-free and not memleak.
> I don't see use-after-free bugs during the testing.
>
> But as mentioned when direct vi/csi client driver unbind happens while=20
> video device node is kept opened, vi driver remove will free vi=20
> structure memory but actual video device memory which is part of=20
> channels remains but list head gets lost when vi structure is freed.
>
> So, when device node is released and executes release callback as list=20
> head is lost it can't free allocated channels which is not good.
>
> This happens only with direct host1x client vi/csi driver unbind.
>
> Need to find better place to free host1x client driver data structure=20
> to allow direct client driver unbind->bind.
>