From patchwork Wed Dec 28 14:42:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 637301 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 93D93C3DA7A for ; Wed, 28 Dec 2022 15:53:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234124AbiL1Pxc (ORCPT ); Wed, 28 Dec 2022 10:53:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232938AbiL1Px2 (ORCPT ); Wed, 28 Dec 2022 10:53:28 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8840186C2; Wed, 28 Dec 2022 07:53:27 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 84529613E9; Wed, 28 Dec 2022 15:53:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4CF8EC433EF; Wed, 28 Dec 2022 15:53:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672242807; bh=3pFuYycp5XaySMSnYBC9uKdZny+VGlfNZ0G0lpWOGrM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p3e/7pZVq2vyyhCntsryNPXW7ZaO6J/uvTjcWxrTz3g19bfLVqhjYhs+lPc1iAVy4 7u8jOvV79did+vEbT3yR7Zj3UuN787r9QrLSllwRxtsG+JQSzEnHMamOd3Q/6sfekG VvpRrqOe/Nsqc8rdbXfNL7vx9koKn3IoHVN6smHw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Rob Clark , Sean Paul , Abhinav Kumar , linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, Dmitry Baryshkov , Daniel Vetter , =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= , Sasha Levin Subject: [PATCH 5.15 649/731] drm/msm: Use drm_mode_copy() Date: Wed, 28 Dec 2022 15:42:36 +0100 Message-Id: <20221228144315.322114745@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144256.536395940@linuxfoundation.org> References: <20221228144256.536395940@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org From: Ville Syrjälä [ Upstream commit b2a1c5ca50db22b3677676dd5bad5f6092429acf ] struct drm_display_mode embeds a list head, so overwriting the full struct with another one will corrupt the list (if the destination mode is on a list). Use drm_mode_copy() instead which explicitly preserves the list head of the destination mode. Even if we know the destination mode is not on any list using drm_mode_copy() seems decent as it sets a good example. Bad examples of not using it might eventually get copied into code where preserving the list head actually matters. Obviously one case not covered here is when the mode itself is embedded in a larger structure and the whole structure is copied. But if we are careful when copying into modes embedded in structures I think we can be a little more reassured that bogus list heads haven't been propagated in. @is_mode_copy@ @@ drm_mode_copy(...) { ... } @depends on !is_mode_copy@ struct drm_display_mode *mode; expression E, S; @@ ( - *mode = E + drm_mode_copy(mode, &E) | - memcpy(mode, E, S) + drm_mode_copy(mode, E) ) @depends on !is_mode_copy@ struct drm_display_mode mode; expression E; @@ ( - mode = E + drm_mode_copy(&mode, &E) | - memcpy(&mode, E, S) + drm_mode_copy(&mode, E) ) @@ struct drm_display_mode *mode; @@ - &*mode + mode Cc: Rob Clark Cc: Sean Paul Cc: Abhinav Kumar Cc: linux-arm-msm@vger.kernel.org Cc: freedreno@lists.freedesktop.org Reviewed-by: Dmitry Baryshkov Reviewed-by: Abhinav Kumar Reviewed-by: Daniel Vetter Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20221107192545.9896-5-ville.syrjala@linux.intel.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/msm/dp/dp_display.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index d13fd39f05de..15e38ad7aefb 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -840,7 +840,7 @@ static int dp_display_set_mode(struct msm_dp *dp_display, dp = container_of(dp_display, struct dp_display_private, dp_display); - dp->panel->dp_mode.drm_mode = mode->drm_mode; + drm_mode_copy(&dp->panel->dp_mode.drm_mode, &mode->drm_mode); dp->panel->dp_mode.bpp = mode->bpp; dp->panel->dp_mode.capabilities = mode->capabilities; dp_panel_init_panel_info(dp->panel);