From patchwork Tue Nov 24 17:36:25 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jani Nikula X-Patchwork-Id: 7692411 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 51F2FBF90C for ; Tue, 24 Nov 2015 17:36:35 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C316F207D3 for ; Tue, 24 Nov 2015 17:36:32 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id A8E31207BB for ; Tue, 24 Nov 2015 17:36:31 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E5BD96E930; Tue, 24 Nov 2015 09:36:30 -0800 (PST) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTP id 5EC156E2DD for ; Tue, 24 Nov 2015 09:36:29 -0800 (PST) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP; 24 Nov 2015 09:36:29 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,339,1444719600"; d="scan'208";a="858864624" Received: from unknown (HELO localhost) ([10.252.29.210]) by fmsmga002.fm.intel.com with ESMTP; 24 Nov 2015 09:36:26 -0800 From: Jani Nikula To: intel-gfx@lists.freedesktop.org Date: Tue, 24 Nov 2015 19:36:25 +0200 Message-Id: <1448386585-4144-1-git-send-email-jani.nikula@intel.com> X-Mailer: git-send-email 2.1.4 Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Cc: jani.nikula@intel.com Subject: [Intel-gfx] [RFC PATCH] drm/i915: fix potential dangling else problems in for_each_ macros X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Spam-Status: No, score=-4.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We have serious dangling else bugs waiting to happen in our for_each_ style macros with ifs. Consider, for example, #define for_each_power_domain(domain, mask) \ for ((domain) = 0; (domain) < POWER_DOMAIN_NUM; (domain)++) \ for_each_if ((1 << (domain)) & (mask)) If this is used in context: if (condition) for_each_power_domain(domain, mask); else foo(); foo() will be called for each domain *not* in mask, if condition holds, and not at all if condition doesn't hold. Fix this by reversing the conditions in the macros, and adding an else branch for the "for each" block, so that other if/else blocks can't interfere. Provide a "for_each_if" helper macro to make it easier to get this right. Signed-off-by: Jani Nikula Reviewed-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_drv.h | 14 ++++++++------ drivers/gpu/drm/i915/intel_display.c | 2 +- drivers/gpu/drm/i915/intel_dsi.h | 2 +- drivers/gpu/drm/i915/intel_runtime_pm.c | 4 ++-- 4 files changed, 12 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 3d8741eff7d3..f9c779fd84ad 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -263,6 +263,8 @@ struct i915_hotplug { I915_GEM_DOMAIN_INSTRUCTION | \ I915_GEM_DOMAIN_VERTEX) +#define for_each_if(condition) if (!(condition)); else + #define for_each_pipe(__dev_priv, __p) \ for ((__p) = 0; (__p) < INTEL_INFO(__dev_priv)->num_pipes; (__p)++) #define for_each_plane(__dev_priv, __pipe, __p) \ @@ -286,7 +288,7 @@ struct i915_hotplug { list_for_each_entry(intel_plane, \ &(dev)->mode_config.plane_list, \ base.head) \ - if ((intel_plane)->pipe == (intel_crtc)->pipe) + for_each_if ((intel_plane)->pipe == (intel_crtc)->pipe) #define for_each_intel_crtc(dev, intel_crtc) \ list_for_each_entry(intel_crtc, &dev->mode_config.crtc_list, base.head) @@ -303,15 +305,15 @@ struct i915_hotplug { #define for_each_encoder_on_crtc(dev, __crtc, intel_encoder) \ list_for_each_entry((intel_encoder), &(dev)->mode_config.encoder_list, base.head) \ - if ((intel_encoder)->base.crtc == (__crtc)) + for_each_if ((intel_encoder)->base.crtc == (__crtc)) #define for_each_connector_on_encoder(dev, __encoder, intel_connector) \ list_for_each_entry((intel_connector), &(dev)->mode_config.connector_list, base.head) \ - if ((intel_connector)->base.encoder == (__encoder)) + for_each_if ((intel_connector)->base.encoder == (__encoder)) #define for_each_power_domain(domain, mask) \ for ((domain) = 0; (domain) < POWER_DOMAIN_NUM; (domain)++) \ - if ((1 << (domain)) & (mask)) + for_each_if ((1 << (domain)) & (mask)) struct drm_i915_private; struct i915_mm_struct; @@ -730,7 +732,7 @@ struct intel_uncore { for ((i__) = 0, (domain__) = &(dev_priv__)->uncore.fw_domain[0]; \ (i__) < FW_DOMAIN_ID_COUNT; \ (i__)++, (domain__) = &(dev_priv__)->uncore.fw_domain[i__]) \ - if (((mask__) & (dev_priv__)->uncore.fw_domains) & (1 << (i__))) + for_each_if (((mask__) & (dev_priv__)->uncore.fw_domains) & (1 << (i__))) #define for_each_fw_domain(domain__, dev_priv__, i__) \ for_each_fw_domain_mask(domain__, FORCEWAKE_ALL, dev_priv__, i__) @@ -1969,7 +1971,7 @@ static inline struct drm_i915_private *guc_to_i915(struct intel_guc *guc) /* Iterate over initialised rings */ #define for_each_ring(ring__, dev_priv__, i__) \ for ((i__) = 0; (i__) < I915_NUM_RINGS; (i__)++) \ - if (((ring__) = &(dev_priv__)->ring[(i__)]), intel_ring_initialized((ring__))) + for_each_if ((((ring__) = &(dev_priv__)->ring[(i__)]), intel_ring_initialized((ring__)))) enum hdmi_force_audio { HDMI_AUDIO_OFF_DVI = -2, /* no aux data for HDMI-DVI converter */ diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 75f03e5bee51..4b21d5e137dc 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -12417,7 +12417,7 @@ static bool intel_fuzzy_clock_check(int clock1, int clock2) list_for_each_entry((intel_crtc), \ &(dev)->mode_config.crtc_list, \ base.head) \ - if (mask & (1 <<(intel_crtc)->pipe)) + for_each_if (mask & (1 <<(intel_crtc)->pipe)) static bool intel_compare_m_n(unsigned int m, unsigned int n, diff --git a/drivers/gpu/drm/i915/intel_dsi.h b/drivers/gpu/drm/i915/intel_dsi.h index e6cb25239941..02551ff228c2 100644 --- a/drivers/gpu/drm/i915/intel_dsi.h +++ b/drivers/gpu/drm/i915/intel_dsi.h @@ -117,7 +117,7 @@ static inline struct intel_dsi_host *to_intel_dsi_host(struct mipi_dsi_host *h) #define for_each_dsi_port(__port, __ports_mask) \ for ((__port) = PORT_A; (__port) < I915_MAX_PORTS; (__port)++) \ - if ((__ports_mask) & (1 << (__port))) + for_each_if ((__ports_mask) & (1 << (__port))) static inline struct intel_dsi *enc_to_intel_dsi(struct drm_encoder *encoder) { diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c index 3fa43af94946..469927edf459 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -54,13 +54,13 @@ i < (power_domains)->power_well_count && \ ((power_well) = &(power_domains)->power_wells[i]); \ i++) \ - if ((power_well)->domains & (domain_mask)) + for_each_if ((power_well)->domains & (domain_mask)) #define for_each_power_well_rev(i, power_well, domain_mask, power_domains) \ for (i = (power_domains)->power_well_count - 1; \ i >= 0 && ((power_well) = &(power_domains)->power_wells[i]);\ i--) \ - if ((power_well)->domains & (domain_mask)) + for_each_if ((power_well)->domains & (domain_mask)) bool intel_display_power_well_is_enabled(struct drm_i915_private *dev_priv, int power_well_id);