From patchwork Fri Feb 18 10:03:48 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: 12751215 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 E3BF7C433FE for ; Fri, 18 Feb 2022 10:04:47 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 68FD210EE77; Fri, 18 Feb 2022 10:04:46 +0000 (UTC) Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id B5D7810ED5F; Fri, 18 Feb 2022 10:04:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1645178682; x=1676714682; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=egpcGDWyNA+kSMrTnKY0NnLDjm381z1cwgUobC378rU=; b=ShBuVxJGZro71XeWwDQi1mcwMGbhbQnYCiPOv91kDpixzFMaQpbgQtwo B3vya6LAkwNmSlPxZby8GWnZHCwgW4sPzP8Tv5hjqdb1jr7BmMBeLSKtJ F6RYcHTIL6G9eKo7YRLIPQmWP6trb7Jnw8VfyR5Y7fnetQuGch65f5Wlp P4liPah5duHFqjymwMZLHF3vI4LCWFXel6cxJ0y0snjdE3a64fjrA5bwl A3LR5QbGy6DG8ZUtBE+mYbddeyhGeqNaofXVyZwwllEYIfMaBj4REnTJQ 7GMk6zApcqed4D7Jx0WYSoyjbfqKhBowpovwp4PI083GymXDra7rMe6J+ w==; X-IronPort-AV: E=McAfee;i="6200,9189,10261"; a="249931187" X-IronPort-AV: E=Sophos;i="5.88,378,1635231600"; d="scan'208";a="249931187" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Feb 2022 02:04:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,378,1635231600"; d="scan'208";a="590153734" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.151]) by fmsmga008.fm.intel.com with SMTP; 18 Feb 2022 02:04:39 -0800 Received: by stinkbox (sSMTP sendmail emulation); Fri, 18 Feb 2022 12:04:39 +0200 From: Ville Syrjala To: dri-devel@lists.freedesktop.org Subject: [PATCH 07/22] drm/gma500: Use drm_mode_copy() Date: Fri, 18 Feb 2022 12:03:48 +0200 Message-Id: <20220218100403.7028-8-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 Cc: Patrik Jakobsson Signed-off-by: Ville Syrjälä Acked-by: Patrik Jakobsson --- drivers/gpu/drm/gma500/oaktrail_crtc.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/gma500/oaktrail_crtc.c b/drivers/gpu/drm/gma500/oaktrail_crtc.c index 36c7c2686c90..79fc602b35bc 100644 --- a/drivers/gpu/drm/gma500/oaktrail_crtc.c +++ b/drivers/gpu/drm/gma500/oaktrail_crtc.c @@ -385,12 +385,8 @@ static int oaktrail_crtc_mode_set(struct drm_crtc *crtc, if (!gma_power_begin(dev, true)) return 0; - memcpy(&gma_crtc->saved_mode, - mode, - sizeof(struct drm_display_mode)); - memcpy(&gma_crtc->saved_adjusted_mode, - adjusted_mode, - sizeof(struct drm_display_mode)); + drm_mode_copy(&gma_crtc->saved_mode, mode); + drm_mode_copy(&gma_crtc->saved_adjusted_mode, adjusted_mode); list_for_each_entry(connector, &mode_config->connector_list, head) { if (!connector->encoder || connector->encoder->crtc != crtc)