From mboxrd@z Thu Jan 1 00:00:00 1970 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 C72E1C433FE for ; Fri, 18 Feb 2022 10:05:45 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4763D10F036; Fri, 18 Feb 2022 10:05:41 +0000 (UTC) Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 14C9310F03B; Fri, 18 Feb 2022 10:05:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1645178738; x=1676714738; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=o6QmNTSo++wA41tkK2nAoAqaUjde1XukDSiTKroARZY=; b=OyCr0ZvzubFEpBi/6s9iHSbUZ9hISWCf2yl3MEnZceRmb+uPJg+KL/lF MBB+krnm5StPxzAFslNsXVzgFKmGvrddNEaiYQ1hs5srMch/1x2VIjDKQ WlCWmtGuuET32D0nt2oZWOY3VEcqKtreDmB3XtBDCcAcb3/CNVfZkRAjA 0O3HoaPoXBUZQ5hMX8GiiWC6OAPQc9cWqdIkbAnF/6Z55P9paL6CSye/s d/ivmG00Gwgzoi8N19N05AoMbRNlNChar348+JE6yqFZMzqW9UEK4PcEt idto2fpbEbWOXr1oyHTrCl+e8lAAKDtLpToGXHaFE7bDd+UPKMW6NYKFt g==; X-IronPort-AV: E=McAfee;i="6200,9189,10261"; a="249931329" X-IronPort-AV: E=Sophos;i="5.88,378,1635231600"; d="scan'208";a="249931329" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Feb 2022 02:05:16 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,378,1635231600"; d="scan'208";a="626574532" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.151]) by FMSMGA003.fm.intel.com with SMTP; 18 Feb 2022 02:05:14 -0800 Received: by stinkbox (sSMTP sendmail emulation); Fri, 18 Feb 2022 12:05:13 +0200 From: Ville Syrjala To: dri-devel@lists.freedesktop.org Subject: [PATCH 16/22] drm/tilcdc: Use drm_mode_copy() Date: Fri, 18 Feb 2022 12:03:57 +0200 Message-Id: <20220218100403.7028-17-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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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, Jyri Sarha , Tomi Valkeinen 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: Jyri Sarha Cc: Tomi Valkeinen Signed-off-by: Ville Syrjälä --- drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c index 29890d704cb4..853c6b443fff 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c @@ -433,7 +433,7 @@ static void tilcdc_crtc_set_mode(struct drm_crtc *crtc) set_scanout(crtc, fb); - crtc->hwmode = crtc->state->adjusted_mode; + drm_mode_copy(&crtc->hwmode, &crtc->state->adjusted_mode); tilcdc_crtc->hvtotal_us = tilcdc_mode_hvtotal(&crtc->hwmode); -- 2.34.1 From mboxrd@z Thu Jan 1 00:00:00 1970 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 C43F8C433F5 for ; Fri, 18 Feb 2022 10:05:49 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C630B10F042; Fri, 18 Feb 2022 10:05:42 +0000 (UTC) Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 14C9310F03B; Fri, 18 Feb 2022 10:05:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1645178738; x=1676714738; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=o6QmNTSo++wA41tkK2nAoAqaUjde1XukDSiTKroARZY=; b=OyCr0ZvzubFEpBi/6s9iHSbUZ9hISWCf2yl3MEnZceRmb+uPJg+KL/lF MBB+krnm5StPxzAFslNsXVzgFKmGvrddNEaiYQ1hs5srMch/1x2VIjDKQ WlCWmtGuuET32D0nt2oZWOY3VEcqKtreDmB3XtBDCcAcb3/CNVfZkRAjA 0O3HoaPoXBUZQ5hMX8GiiWC6OAPQc9cWqdIkbAnF/6Z55P9paL6CSye/s d/ivmG00Gwgzoi8N19N05AoMbRNlNChar348+JE6yqFZMzqW9UEK4PcEt idto2fpbEbWOXr1oyHTrCl+e8lAAKDtLpToGXHaFE7bDd+UPKMW6NYKFt g==; X-IronPort-AV: E=McAfee;i="6200,9189,10261"; a="249931329" X-IronPort-AV: E=Sophos;i="5.88,378,1635231600"; d="scan'208";a="249931329" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Feb 2022 02:05:16 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,378,1635231600"; d="scan'208";a="626574532" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.151]) by FMSMGA003.fm.intel.com with SMTP; 18 Feb 2022 02:05:14 -0800 Received: by stinkbox (sSMTP sendmail emulation); Fri, 18 Feb 2022 12:05:13 +0200 From: Ville Syrjala To: dri-devel@lists.freedesktop.org Date: Fri, 18 Feb 2022 12:03:57 +0200 Message-Id: <20220218100403.7028-17-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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Intel-gfx] [PATCH 16/22] drm/tilcdc: Use drm_mode_copy() X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, Jyri Sarha , Tomi Valkeinen Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" 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: Jyri Sarha Cc: Tomi Valkeinen Signed-off-by: Ville Syrjälä --- drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c index 29890d704cb4..853c6b443fff 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c @@ -433,7 +433,7 @@ static void tilcdc_crtc_set_mode(struct drm_crtc *crtc) set_scanout(crtc, fb); - crtc->hwmode = crtc->state->adjusted_mode; + drm_mode_copy(&crtc->hwmode, &crtc->state->adjusted_mode); tilcdc_crtc->hvtotal_us = tilcdc_mode_hvtotal(&crtc->hwmode); -- 2.34.1