From patchwork Mon Nov 7 19:25:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ville Syrjala X-Patchwork-Id: 13035179 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 52CA7C4332F for ; Mon, 7 Nov 2022 19:26:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232153AbiKGT0W (ORCPT ); Mon, 7 Nov 2022 14:26:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56370 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230527AbiKGT0F (ORCPT ); Mon, 7 Nov 2022 14:26:05 -0500 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E54682AE07 for ; Mon, 7 Nov 2022 11:26:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1667849164; x=1699385164; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=2bw5zKTHI9yIJMex3mKA2JskRc/jd7Risgf6Zf76vdU=; b=ADcUgeX5zBP3SnnsP4fFWGbRKB+pcED6yXiWSzfAVNqUizD8k4YHyJg+ NayGg+Ma51hvpLsFXruQu8I9TrZV7jou6j8pgLEt4+CY8AQjktWBsBs2p UwQ7SPg58CEaBhNFl3ALbDm/XknlHWji55SSFFs6tH2HJ5h6sI0DmPuYd wtNnDTBTlPqGNqtieo9/aPP8TAmWz7SqPu7Wu+YQ9FrBF3CRdZVJCyd4O aWJamV/gLgLZ1e1OgF/0C62mykLfHWMbZwPutn4H5AXCy5sTrDne0UlLt PnIYyzerZ6WxjHxSmox+4Pdd3sRLHUmpmEBABsxWD1so0wS6iEfw8A5Rd g==; X-IronPort-AV: E=McAfee;i="6500,9779,10524"; a="372642946" X-IronPort-AV: E=Sophos;i="5.96,145,1665471600"; d="scan'208";a="372642946" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Nov 2022 11:26:04 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10524"; a="705009791" X-IronPort-AV: E=Sophos;i="5.96,145,1665471600"; d="scan'208";a="705009791" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.191]) by fmsmga004.fm.intel.com with SMTP; 07 Nov 2022 11:26:01 -0800 Received: by stinkbox (sSMTP sendmail emulation); Mon, 07 Nov 2022 21:26:00 +0200 From: Ville Syrjala To: dri-devel@lists.freedesktop.org Cc: Rob Clark , Sean Paul , Abhinav Kumar , linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, Dmitry Baryshkov Subject: [PATCH v2 4/7] drm/msm: Use drm_mode_copy() Date: Mon, 7 Nov 2022 21:25:42 +0200 Message-Id: <20221107192545.9896-5-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 2.37.4 In-Reply-To: <20221107192545.9896-1-ville.syrjala@linux.intel.com> References: <20221107192545.9896-1-ville.syrjala@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org From: Ville Syrjälä 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 Signed-off-by: Ville Syrjälä --- 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 a49f6dbbe888..c9d9b384ddd0 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -857,7 +857,7 @@ 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);