From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754947AbcLOSKC (ORCPT ); Thu, 15 Dec 2016 13:10:02 -0500 Received: from mail-wm0-f65.google.com ([74.125.82.65]:33474 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753378AbcLOSKA (ORCPT ); Thu, 15 Dec 2016 13:10:00 -0500 To: linux-kbuild@vger.kernel.org Cc: LKML , yann.morin.1998@free.fr, mmarek@suse.com From: Nikolay Borisov Subject: default 0 if KASAN expression not working in kbuild Message-ID: Date: Thu, 15 Dec 2016 20:09:27 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, I was doing some kasan-related debugging and when I enabled it I started getting warnings for large stackframes. So CONFIG_FRAME_WARN has : int "Warn for stack frames larger than (needs gcc 4.4)" range 0 8192 default 0 if KASAN default 2048 if GCC_PLUGIN_LATENT_ENTROPY default 1024 if !64BIT default 2048 if 64BIT This means that frame_warns should effectively be disabled when kasan is enabled. However in my case this is not the situation. http://sprunge.us/FiGf here is the config file. It does have CONFIG_KASAN=y and CONFIG_FRAME_WARN=1024 . And even this is erroneous since it's a 64bit kernel, so it should be 2k. I haven't manually set the limit to 1k either. Regards, Nikolay