Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754524AbdCTLYU (ORCPT ); Mon, 20 Mar 2017 07:24:20 -0400 Received: from mga09.intel.com ([134.134.136.24]:63912 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753906AbdCTLYQ (ORCPT ); Mon, 20 Mar 2017 07:24:16 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,194,1486454400"; d="scan'208";a="836600446" From: Jani Nikula To: Arnd Bergmann Cc: Daniel Vetter , David Airlie , Mika Kuoppala , Ville =?utf-8?B?U3lyasOkbMOk?= , Chris Wilson , Imre Deak , Ander Conselvan de Oliveira , Robert Bragg , intel-gfx@lists.freedesktop.org, dri-devel , Linux Kernel Mailing List Subject: Re: [PATCH 3/3] [RFC] Revert "drm/i915: use variadic macros and arrays to choose port/pipe based registers" In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20170320094335.1266306-1-arnd@arndb.de> <20170320094335.1266306-3-arnd@arndb.de> <87shm8b6rj.fsf@intel.com> Date: Mon, 20 Mar 2017 13:24:02 +0200 Message-ID: <87o9wwb38t.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 989 Lines: 28 On Mon, 20 Mar 2017, Arnd Bergmann wrote: > I don't know how to generate a URL for it, but after adding this to the > command line for gcc-7, > > -fsanitize=kernel-address -fasan-shadow-offset=0xdfff900000000000 > --param asan-stack=1 --param asan-globals=1 --param > asan-instrumentation-with-call-threshold=10000 > -fsanitize-address-use-after-scope > > the code turned from really nice into the log series of checks below. > Without -fsanitize-address-use-after-scope (which didn't exist before gcc-7), > it's less bad but still exceeds the (arbitrary) 1536 byte limit. It seems to be the combination of --param asan-stack=1 and -fsanitize-address-use-after-scope that really blows up the code [1]. I filed a GCC bug on it, mostly to see what they say [2]. I don't know, maybe they think it's expected. *shrug*. BR, Jani. [1] https://godbolt.org/g/hgS817 [2] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80114 -- Jani Nikula, Intel Open Source Technology Center