From patchwork Fri Feb 18 10:04:03 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: 12751228 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 520B0C433F5 for ; Fri, 18 Feb 2022 10:05:42 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D6C1210F035; Fri, 18 Feb 2022 10:05:39 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7075710F047; Fri, 18 Feb 2022 10:05:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1645178737; x=1676714737; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=qaTNC+xXZmSxaE21z5U0LL34TH0l+uk/IjYSVhvcYhs=; b=G4E6EmJA1xui9xLsIYcj3s5+yPvt27LJHUWZZEoIE1iki5K0IQV+lVpG 9lSzYMRiWxVB/hsBR8zNsK4eXPwzbq3NUVf53Ez1r/3Uv7s5bFFRHiDSI dgh4QQ2FatAriqjiN+SFMvo7abPC2uB1kTNo9KN0JIzdJwaCcOiDwixLG sBeLhxgBW/hSBTVXatlaIVbwdysmE1VYQiKY79CvFGFXe0dg9btz4l0n3 YI2wdd2scFQXGvlW5K32B75rK4teOdN2pPd9h/mo7UsWaztPoXqAL4Wt4 O+J8KZXahpcyW/o/UWe9OLHwtI406uOjQyjgx0+6zOV4gm0jULF73rubk g==; X-IronPort-AV: E=McAfee;i="6200,9189,10261"; a="337541527" X-IronPort-AV: E=Sophos;i="5.88,378,1635231600"; d="scan'208";a="337541527" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Feb 2022 02:05:36 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,378,1635231600"; d="scan'208";a="530863934" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.151]) by orsmga007.jf.intel.com with SMTP; 18 Feb 2022 02:05:33 -0800 Received: by stinkbox (sSMTP sendmail emulation); Fri, 18 Feb 2022 12:05:33 +0200 From: Ville Syrjala To: dri-devel@lists.freedesktop.org Subject: [PATCH 22/22] drm: Use drm_mode_copy() Date: Fri, 18 Feb 2022 12:04:03 +0200 Message-Id: <20220218100403.7028-23-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 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 Signed-off-by: Ville Syrjälä Reviewed-by: Andrzej Hajda --- drivers/gpu/drm/drm_crtc_helper.c | 4 ++-- drivers/gpu/drm/drm_vblank.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index a34aa009725f..b632825654a9 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -305,7 +305,7 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc, /* Update crtc values up front so the driver can rely on them for mode * setting. */ - crtc->mode = *mode; + drm_mode_copy(&crtc->mode, mode); crtc->x = x; crtc->y = y; @@ -341,7 +341,7 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc, } DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name); - crtc->hwmode = *adjusted_mode; + drm_mode_copy(&crtc->hwmode, adjusted_mode); /* Prepare the encoders and CRTCs before setting the mode. */ drm_for_each_encoder(encoder, dev) { diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index b701cda86d0c..2ff31717a3de 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -644,7 +644,7 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc, vblank->linedur_ns = linedur_ns; vblank->framedur_ns = framedur_ns; - vblank->hwmode = *mode; + drm_mode_copy(&vblank->hwmode, mode); drm_dbg_core(dev, "crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",