From patchwork Fri Feb 18 10:03:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= X-Patchwork-Id: 12751225 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0E425C433F5 for ; Fri, 18 Feb 2022 10:05:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 18D1E10F021; Fri, 18 Feb 2022 10:05:26 +0000 (UTC) Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1627E10F020; Fri, 18 Feb 2022 10:05:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1645178721; x=1676714721; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=eCrT7k2mHaCOKRYO1OSCuF6nl+eIp+hDzsgznOb6nEY=; b=asdFGhZd3EJrRk7+gHa4w5TejVjlm5pOwOGRSm0w0LHMCnmb/Sd2CRpq ST/86yS1xoLPx5HW2ez5JztarS88R0UMkJiQCjtJ0pD3/xl0XDABEI61m w3cn+qNHPSi/X5THFo2w24et9+qGySLqmtANiJb7JouzL0SIMi653Fpz6 rP00PMQsnbkZDPWdG2+a+ifgLmcwqZoL1RFxdbmgQvb1bKDrHzMZYzKyp AehAHmnAfPu/C5k51FElBYs/zDzDvQcKvAYoo1Ntyc+Lacbp7k+A83a7u n/oSezVRMloiLGRuWVojsZUmC4x77gzCSpvnxRtCVGr44VOMxOhs2z4Jb w==; X-IronPort-AV: E=McAfee;i="6200,9189,10261"; a="311839937" X-IronPort-AV: E=Sophos;i="5.88,378,1635231600"; d="scan'208";a="311839937" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Feb 2022 02:05:20 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,378,1635231600"; d="scan'208";a="590153924" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.151]) by fmsmga008.fm.intel.com with SMTP; 18 Feb 2022 02:05:17 -0800 Received: by stinkbox (sSMTP sendmail emulation); Fri, 18 Feb 2022 12:05:17 +0200 From: Ville Syrjala To: dri-devel@lists.freedesktop.org Subject: [PATCH 17/22] drm/vc4: Use drm_mode_copy() Date: Fri, 18 Feb 2022 12:03:58 +0200 Message-Id: <20220218100403.7028-18-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220218100403.7028-1-ville.syrjala@linux.intel.com> References: <20220218100403.7028-1-ville.syrjala@linux.intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, Emma Anholt Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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: Emma Anholt Cc: Maxime Ripard Signed-off-by: Ville Syrjälä --- drivers/gpu/drm/vc4/vc4_hdmi.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index 5ac3216f2d4a..6c58b0fd13fb 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -1234,9 +1234,8 @@ static void vc4_hdmi_encoder_atomic_mode_set(struct drm_encoder *encoder, struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder); mutex_lock(&vc4_hdmi->mutex); - memcpy(&vc4_hdmi->saved_adjusted_mode, - &crtc_state->adjusted_mode, - sizeof(vc4_hdmi->saved_adjusted_mode)); + drm_mode_copy(&vc4_hdmi->saved_adjusted_mode, + &crtc_state->adjusted_mode); mutex_unlock(&vc4_hdmi->mutex); }