Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754545AbcKYJAA (ORCPT ); Fri, 25 Nov 2016 04:00:00 -0500 Received: from mx2.suse.de ([195.135.220.15]:45310 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752550AbcKYIbK (ORCPT ); Fri, 25 Nov 2016 03:31:10 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Arnd Bergmann , Inki Dae , Jiri Slaby Subject: [PATCH 3.12 043/127] drm/exynos: fix error handling in exynos_drm_subdrv_open Date: Fri, 25 Nov 2016 09:29:16 +0100 Message-Id: <77b4c57fbe7ea2fbc337040b511cad340ffbf058.1480062521.git.jslaby@suse.cz> X-Mailer: git-send-email 2.10.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1844 Lines: 48 From: Arnd Bergmann 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 55c4b906aa2aec3fa66310ec03c6842e34a04b2a upstream. gcc-6 warns about a pointless loop in exynos_drm_subdrv_open: drivers/gpu/drm/exynos/exynos_drm_core.c: In function 'exynos_drm_subdrv_open': drivers/gpu/drm/exynos/exynos_drm_core.c:104:199: error: self-comparison always evaluates to false [-Werror=tautological-compare] list_for_each_entry_reverse(subdrv, &subdrv->list, list) { Here, the list_for_each_entry_reverse immediately terminates because the subdrv pointer is compared to itself as the loop end condition. If we were to take the current subdrv pointer as the start of the list (as we would do if list_for_each_entry_reverse() was not a macro), we would iterate backwards over the &exynos_drm_subdrv_list anchor, which would be even worse. Instead, we need to use list_for_each_entry_continue_reverse() to go back over each subdrv that was successfully opened until the first entry. Signed-off-by: Arnd Bergmann Signed-off-by: Inki Dae Signed-off-by: Jiri Slaby --- drivers/gpu/drm/exynos/exynos_drm_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/exynos/exynos_drm_core.c b/drivers/gpu/drm/exynos/exynos_drm_core.c index 1bef6dc77478..6d521497e3b4 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_core.c +++ b/drivers/gpu/drm/exynos/exynos_drm_core.c @@ -204,7 +204,7 @@ int exynos_drm_subdrv_open(struct drm_device *dev, struct drm_file *file) return 0; err: - list_for_each_entry_reverse(subdrv, &subdrv->list, list) { + list_for_each_entry_continue_reverse(subdrv, &exynos_drm_subdrv_list, list) { if (subdrv->close) subdrv->close(dev, subdrv->dev, file); } -- 2.10.2