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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 866E4C3F349 for ; Thu, 27 Feb 2020 13:43:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 54C5F20726 for ; Thu, 27 Feb 2020 13:43:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582810988; bh=IEqL5xJdvkCDBxzC/BErSDTVMFN7oI3hvjjONr0p9Tw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jPcL/WFRdXVsJe+LYHDjJahvFdEVXy5q5ca6h5+/T3Sp7A04Z9I42a8eTQvdoA14c 1O50Ey1ry9vFwk2lKU+nhvkrrvmEco3Nk0P6an5pn3/uQGJdQ8KuOCBhIEesg2SWXa W2W+QsZCShDhCzDvyxroN1LLNADqA0z/3nlAO1rk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729908AbgB0NnH (ORCPT ); Thu, 27 Feb 2020 08:43:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:38196 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729580AbgB0NnE (ORCPT ); Thu, 27 Feb 2020 08:43:04 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E52A020726; Thu, 27 Feb 2020 13:43:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582810984; bh=IEqL5xJdvkCDBxzC/BErSDTVMFN7oI3hvjjONr0p9Tw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m7r6GJI2m/q861am+/PTQ4S6EU+5gsHzVepu6/noGOz7aAd7ugIA2S1BdjGXvtfZH pizRB6pk8pyyySJYlcPXhAxIjuhUUSViuH+RROBgwA196Fiphgn7ulfvJCMzWWK4sm fvfj7N+M6ZVOCWksQtw3iwj0RFyDJU3UOgvRxGIg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ben Skeggs , Sasha Levin Subject: [PATCH 4.4 073/113] drm/nouveau/disp/nv50-: prevent oops when no channel method map provided Date: Thu, 27 Feb 2020 14:36:29 +0100 Message-Id: <20200227132223.480230801@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200227132211.791484803@linuxfoundation.org> References: <20200227132211.791484803@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ben Skeggs [ Upstream commit 0e6176c6d286316e9431b4f695940cfac4ffe6c2 ] The implementations for most channel types contains a map of methods to priv registers in order to provide debugging info when a disp exception has been raised. This info is missing from the implementation of PIO channels as they're rather simplistic already, however, if an exception is raised by one of them, we'd end up triggering a NULL-pointer deref. Not ideal... Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=206299 Signed-off-by: Ben Skeggs Signed-off-by: Sasha Levin --- drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c index 01803c0679b68..d012df9fb9df0 100644 --- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c +++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c @@ -72,6 +72,8 @@ nv50_disp_chan_mthd(struct nv50_disp_chan *chan, int debug) if (debug > subdev->debug) return; + if (!mthd) + return; for (i = 0; (list = mthd->data[i].mthd) != NULL; i++) { u32 base = chan->head * mthd->addr; -- 2.20.1