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 X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ADBD0C32753 for ; Fri, 2 Aug 2019 05:37:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4D0B82073D for ; Fri, 2 Aug 2019 05:37:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ftzFVjyf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D0B82073D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A1C196B0008; Fri, 2 Aug 2019 01:37:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9CD416B000A; Fri, 2 Aug 2019 01:37:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8BB146B000C; Fri, 2 Aug 2019 01:37:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pl1-f199.google.com (mail-pl1-f199.google.com [209.85.214.199]) by kanga.kvack.org (Postfix) with ESMTP id 56A946B0008 for ; Fri, 2 Aug 2019 01:37:27 -0400 (EDT) Received: by mail-pl1-f199.google.com with SMTP id q11so40919896pll.22 for ; Thu, 01 Aug 2019 22:37:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:date:from:to:cc:subject :message-id:references:mime-version:content-disposition:in-reply-to :user-agent; bh=ihRIEHRjtJIPus/danpDF2O/WfsfhF+xvDGQLaVGba0=; b=s7GD5VXE+mktIj3vDSUhyBnW3s7dSmOelTj4JB/BdlAjAdOtyHUvfmXPurpLSZ3DQF WGTJEUg5YUtPVGLEDCt4rKXS8D8nwf2r8QDfmPSqgMV4ZiVUK92xVWQgNXtlY9fVGX7k +jRf/qf1rpf7yis+EbF5HfyGw//6+fnum5lD9YwzUBndlbmxj4/1GASEJ16XjQK4V2G3 zI6ISwDa/jwyX8mtZpL9Y45KzigvPpgxFmwUe82gdRVGDMszcnul3mjnVQqhyaYptKo4 kIgtcjllxhWFAN83hGcuctpdd5TmZ6ZLSQO6dz0xDS2YEaCNl2zjvFIgA5s6EqbBcF+z pCyw== X-Gm-Message-State: APjAAAWjDkVyJRzUj2BvthsCOW3YDFLDy+HExMZAe8YQs7hfhBgSMJ5g Y5tz8Tp6U5kUHBN0W7f36LXuXji9VO0oLrCIoxx3DT457Ne1uSL28n1uATPK+/chetIJ2ue5cds tkWUTxfiGfBzYeAHu+Zb/qo232wjFstzxRpYdRmWT+Mz99DFjDlNjwyPU5qAkuvTh6w== X-Received: by 2002:a63:2264:: with SMTP id t36mr115304245pgm.87.1564724246771; Thu, 01 Aug 2019 22:37:26 -0700 (PDT) X-Received: by 2002:a63:2264:: with SMTP id t36mr115304202pgm.87.1564724245828; Thu, 01 Aug 2019 22:37:25 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1564724245; cv=none; d=google.com; s=arc-20160816; b=Ul4m8ESkDOUmHCoWYfE3t5rzZC8AzW4ff42j7t81/dbWt1GhH/RmX4iKASLZInnM8J RzFapm/EEFkUp63Ajb6EiE65CD0jZX+m2j8zqoE8BuGnegqhTA3im7NP47IXLbd6n3v9 xasX5c63+F9bCQAJFspFBCCMXBw73QtzSk1PraP/tlIyuiqXm50ijpmRHV/P8sDP7dGD 639oYntTlr5cnHibqsxCTm6VN/6KlwX3tP/61J0I+fevw/2DS6d7vhJBaVOFvERITW0j ndFjlvez/j3JpCi1kEgQzUEiFh7LgLHZnL6l5EAGCDuHJ5AMFSdZD7EXsNVs2ETOd3L2 9VZg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:dkim-signature; bh=ihRIEHRjtJIPus/danpDF2O/WfsfhF+xvDGQLaVGba0=; b=LnVUyoxrQmSI4B3P1nuw5YmbnXCiHx4Zy6k/utJ6M6kj+X7lBUcQCX94RNQPX4OzZm p8cJU+p8qAx3ToSWImDFN6umKs/rYDA5GbvtcdJf+eHAqpGqv/hCwx5jbJy+VotlAX0z BuvB7MZT8JMT/eqgtPktfC8FNdmapprRb3hRIHSr3+qfxh+cRCyGSn/Zp8+LIZxw2uTU pSeSAjMRoNY5bhCYN3Ju5wethQoZNdHq63YTR7XXl7IdFJMXTMo/Q7t5T9PjPgenqT1s RRGjFul/O/v9Lu8DmYrnKEvrwKteHsyAGxVnYZkz8aIxAG4KaTQ1+TXCcVu/oeDqaXCE /GQg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=ftzFVjyf; spf=pass (google.com: domain of sergey.senozhatsky.work@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=sergey.senozhatsky.work@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id b9sor88523364plb.21.2019.08.01.22.37.25 for (Google Transport Security); Thu, 01 Aug 2019 22:37:25 -0700 (PDT) Received-SPF: pass (google.com: domain of sergey.senozhatsky.work@gmail.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=ftzFVjyf; spf=pass (google.com: domain of sergey.senozhatsky.work@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=sergey.senozhatsky.work@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=ihRIEHRjtJIPus/danpDF2O/WfsfhF+xvDGQLaVGba0=; b=ftzFVjyfXoKLkBYNUMy31X98rL/NnJ8hllXWpl0KRZE/jG55BdBSqB5J1eDuE9kY7a aOrDSt03+MjcLtacH3layAaidKQ6bFw2OUKmk1j6Ol9G426SpZEcIf/M1fZRfSsuAJYj C6+SzwOAVWFe0xcQC/KGNlvgWQMGGBooqyrnAWQom/dNI0UjuYp7RayvRxOegnWThP25 Tey1oildsxoH7wSomoGATwjH1OmclS1/j9TMY7I6PZ9Fe70UuJMWMHkIR5Z1qfdJ+JvX asuve8Y7Sd9y66IvBmlGl2LuEZN88zQPY/rDQC+SP4UvLmMQWmpALsqq4rtj5qPrJU3d 2Wfw== X-Google-Smtp-Source: APXvYqyxSYMw4QN2SRQ515CrxjGKV3nanM01epjwWH4RWeHALCxAI0t+x/3BqYGx0VGsG1ZUoXSy1Q== X-Received: by 2002:a17:902:1004:: with SMTP id b4mr131792482pla.325.1564724245276; Thu, 01 Aug 2019 22:37:25 -0700 (PDT) Received: from localhost ([175.223.19.29]) by smtp.gmail.com with ESMTPSA id q19sm77991081pfc.62.2019.08.01.22.37.23 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Thu, 01 Aug 2019 22:37:24 -0700 (PDT) Date: Fri, 2 Aug 2019 14:37:20 +0900 From: Sergey Senozhatsky To: Chris Wilson Cc: Sergey Senozhatsky , David Airlie , intel-gfx@lists.freedesktop.org, Hugh Dickins , linux-kernel@vger.kernel.org, David Howells , linux-mm@kvack.org, dri-devel@lists.freedesktop.org, Andrew Morton Subject: Re: [Intel-gfx] [linux-next] mm/i915: i915_gemfs_init() NULL dereference Message-ID: <20190802053720.GA3838@jagdpanzerIV> References: <20190721142930.GA480@tigerII.localdomain> <20190731164829.GA399@tigerII.localdomain> <156468064507.12570.1311173864105235053@skylake-alporthouse-com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <156468064507.12570.1311173864105235053@skylake-alporthouse-com> User-Agent: Mutt/1.12.1 (2019-06-15) 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 (08/01/19 18:30), Chris Wilson wrote: > Quoting Sergey Senozhatsky (2019-07-31 17:48:29) > > @@ -36,19 +38,35 @@ int i915_gemfs_init(struct drm_i915_private *i915) [..] > > + if (!fc->ops->parse_monolithic) > > + goto err; > > + > > + err = fc->ops->parse_monolithic(fc, options); > > + if (err) > > + goto err; > > + > > + if (!fc->ops->reconfigure) > > It would be odd for fs_context_for_reconfigure() to allow creation of a > context if that context couldn't perform a reconfigre, nevertheless that > seems to be the case. Well, I kept those checks just because fs/ code does the same. E.g. fs/super.c reconfigure_super() { if (fc->ops->reconfigure) fc->ops->reconfigure(fc) } do_emergency_remount_callback() { fc = fs_context_for_reconfigure(); reconfigure_super(fc); } > > + goto err; > > + > > + err = fc->ops->reconfigure(fc); > > + if (err) > > + goto err; > > Only thing that stands out is that we should put_fs_context() here as > well. Oh... Indeed, somehow I forgot to put_fs_context(). > I guess it's better than poking at the SB_INFO directly ourselves. > I think though we shouldn't bail if we can't change the thp setting, and > just accept whatever with a warning. OK. > Looks like the API is already available in dinq, so we can apply this > ahead of the next merge window. OK, will cook a formal patch then. Thanks! -ss