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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 B7EDFC433E0 for ; Mon, 18 Jan 2021 19:12:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8448B22573 for ; Mon, 18 Jan 2021 19:12:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437189AbhARTMP convert rfc822-to-8bit (ORCPT ); Mon, 18 Jan 2021 14:12:15 -0500 Received: from aposti.net ([89.234.176.197]:38822 "EHLO aposti.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390494AbhARLiv (ORCPT ); Mon, 18 Jan 2021 06:38:51 -0500 Date: Mon, 18 Jan 2021 11:37:49 +0000 From: Paul Cercueil Subject: Re: [PATCH 2/3] drm/ingenic: Register devm action to cleanup encoders To: Laurent Pinchart Cc: David Airlie , Daniel Vetter , linux-kernel@vger.kernel.org, stable@vger.kernel.org, od@zcrc.me, dri-devel@lists.freedesktop.org, Sam Ravnborg Message-Id: <1BO4NQ.1RZAXLMVC01T@crapouillou.net> In-Reply-To: References: <20210117112646.98353-1-paul@crapouillou.net> <20210117112646.98353-3-paul@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Laurent, Le lun. 18 janv. 2021 à 11:43, Laurent Pinchart a écrit : > Hi Paul, > > Thank you for the patch. > > On Sun, Jan 17, 2021 at 11:26:45AM +0000, Paul Cercueil wrote: >> Since the encoders have been devm-allocated, they will be freed way >> before drm_mode_config_cleanup() is called. To avoid use-after-free >> conditions, we then must ensure that drm_encoder_cleanup() is called >> before the encoders are freed. > > How about allocating the encoder with drmm_encoder_alloc() instead ? That would work, but it is not yet in drm-misc-fixes :( -Paul >> Fixes: c369cb27c267 ("drm/ingenic: Support multiple panels/bridges") >> Cc: # 5.8+ >> Signed-off-by: Paul Cercueil >> --- >> drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c >> b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c >> index 368bfef8b340..d23a3292a0e0 100644 >> --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c >> +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c >> @@ -803,6 +803,11 @@ static void __maybe_unused >> ingenic_drm_release_rmem(void *d) >> of_reserved_mem_device_release(d); >> } >> >> +static void ingenic_drm_encoder_cleanup(void *encoder) >> +{ >> + drm_encoder_cleanup(encoder); >> +} >> + >> static int ingenic_drm_bind(struct device *dev, bool >> has_components) >> { >> struct platform_device *pdev = to_platform_device(dev); >> @@ -1011,6 +1016,11 @@ static int ingenic_drm_bind(struct device >> *dev, bool has_components) >> return ret; >> } >> >> + ret = devm_add_action_or_reset(dev, ingenic_drm_encoder_cleanup, >> + encoder); >> + if (ret) >> + return ret; >> + >> ret = drm_bridge_attach(encoder, bridge, NULL, 0); >> if (ret) { >> dev_err(dev, "Unable to attach bridge\n"); > > -- > Regards, > > Laurent Pinchart