From patchwork Wed Dec 21 23:19:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marijn Suijten X-Patchwork-Id: 13079302 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 C2F8DC10F1B for ; Wed, 21 Dec 2022 23:20:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235081AbiLUXUS (ORCPT ); Wed, 21 Dec 2022 18:20:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234731AbiLUXUF (ORCPT ); Wed, 21 Dec 2022 18:20:05 -0500 Received: from m-r1.th.seeweb.it (m-r1.th.seeweb.it [IPv6:2001:4b7a:2000:18::170]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EFA0224F1C; Wed, 21 Dec 2022 15:20:03 -0800 (PST) Received: from localhost.localdomain (94-209-172-39.cable.dynamic.v4.ziggo.nl [94.209.172.39]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by m-r1.th.seeweb.it (Postfix) with ESMTPSA id 74115203C9; Thu, 22 Dec 2022 00:20:01 +0100 (CET) From: Marijn Suijten To: phone-devel@vger.kernel.org, Rob Clark , Abhinav Kumar , Dmitry Baryshkov , Vinod Koul Cc: ~postmarketos/upstreaming@lists.sr.ht, AngeloGioacchino Del Regno , Konrad Dybcio , Martin Botka , Jami Kettunen , Marijn Suijten , Sean Paul , David Airlie , Daniel Vetter , Stephen Boyd , Bjorn Andersson , Jessica Zhang , =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= , Kuogee Hsieh , Jani Nikula , sunliming , Sam Ravnborg , Haowen Bai , Konrad Dybcio , Loic Poulain , Vinod Polimera , Douglas Anderson , Vladimir Lypak , linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org, Drew Davenport Subject: [PATCH v2 4/8] drm/msm/dpu: Disallow unallocated resources to be returned Date: Thu, 22 Dec 2022 00:19:39 +0100 Message-Id: <20221221231943.1961117-5-marijn.suijten@somainline.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221221231943.1961117-1-marijn.suijten@somainline.org> References: <20221221231943.1961117-1-marijn.suijten@somainline.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org In the event that the topology requests resources that have not been created by the system (because they are typically not represented in dpu_mdss_cfg ^1), the resource(s) in global_state (in this case DSC blocks) remain NULL but will still be returned out of dpu_rm_get_assigned_resources, where the caller expects to get an array containing num_blks valid pointers (but instead gets these NULLs). To prevent this from happening, where null-pointer dereferences typically result in a hard-to-debug platform lockup, num_blks shouldn't increase past NULL blocks and will print an error and break instead. After all, max_blks represents the static size of the maximum number of blocks whereas the actual amount varies per platform. ^1: which can happen after a git rebase ended up moving additions to _dpu_cfg to a different struct which has the same patch context. Fixes: bb00a452d6f7 ("drm/msm/dpu: Refactor resource manager") Signed-off-by: Marijn Suijten --- drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c index 73b3442e7467..8471d04bff50 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c @@ -660,6 +660,11 @@ int dpu_rm_get_assigned_resources(struct dpu_rm *rm, blks_size, enc_id); break; } + if (!hw_blks[i]) { + DPU_ERROR("No more resource %d available to assign to enc %d\n", + type, enc_id); + break; + } blks[num_blks++] = hw_blks[i]; }