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=-2.2 required=3.0 tests=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 724A9C282DD for ; Thu, 9 Jan 2020 19:01:35 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 47D82206ED for ; Thu, 9 Jan 2020 19:01:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 47D82206ED Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B72EE6E030; Thu, 9 Jan 2020 19:01:34 +0000 (UTC) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by gabe.freedesktop.org (Postfix) with ESMTPS id AE22E6E030 for ; Thu, 9 Jan 2020 19:01:33 +0000 (UTC) X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Jan 2020 11:01:33 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,414,1571727600"; d="scan'208";a="235797790" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by orsmga002.jf.intel.com with SMTP; 09 Jan 2020 11:01:30 -0800 Received: by stinkbox (sSMTP sendmail emulation); Thu, 09 Jan 2020 21:01:28 +0200 Date: Thu, 9 Jan 2020 21:01:28 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Chris Wilson Message-ID: <20200109190127.GH13686@intel.com> References: <20200109141152.975687-1-chris@chris-wilson.co.uk> <20200109145241.GO1208@intel.com> <20200109183709.GG13686@intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200109183709.GG13686@intel.com> X-Patchwork-Hint: comment User-Agent: Mutt/1.10.1 (2018-07-13) Subject: Re: [Intel-gfx] [PATCH] drm/i915/gt: Validation rotated vma bounds are within the object X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Thu, Jan 09, 2020 at 08:37:09PM +0200, Ville Syrj=E4l=E4 wrote: > On Thu, Jan 09, 2020 at 04:52:41PM +0200, Ville Syrj=E4l=E4 wrote: > > On Thu, Jan 09, 2020 at 02:11:52PM +0000, Chris Wilson wrote: > > > Quite understandably, we bug out when asked to find a page that doesn= 't > > > belong to the object. However, we should report the error back to the > > > user long before we attempt the out-of-bound access! In this case, it= is > > > insufficient validation on the rotated vma, with the simplest/cheapest > > > point for us to insert a bound check when we are computing the rotated > > > page lookups. > > > = > > > Similarly, it might be wise to see if we can validate the user input > > > upon creating the rotated framebuffer. > > = > > We do. Did someone break it? > = > One theory on how this could happens is that we are using a stale gtt > view here. But AFAICS the only way that could happen is that we take > a shortcut out from the plane check somewhere before populating > plane_state->gtt_view afresh, after using a rotated fb previously so > that plane_state->gtt_view has been populated with a rotated view. > = > The first such path I see is: > intel_plane_atomic_check_with_state() > { > ... > if (!new_plane_state->hw.crtc && !old_plane_state->hw.crtc) > return 0; > = > but that should also imply new_plane_state->hw.fb=3D=3DNULL and so we > should not end up pinning the fb. > = > The second path is: > intel_plane_compute_gtt() > { > const struct intel_framebuffer *fb =3D > to_intel_framebuffer(plane_state->hw.fb); > = > if (!fb) > return 0; > = > and so we won't have a new fb there either and so shouldn't try > to pin it. > = > So can't see how that could happen from these normal paths. Which > leads me to wonder if this might have something to do with nv12 > slave planes... That may well be it. Looks like we may not end up calling intel_plane_copy_uapi_to_hw_state() for old slave planes at all, thus leaving a stale plane_state->hw.fb pointer behind. -- = Ville Syrj=E4l=E4 Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx