From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756688Ab3K0R4q (ORCPT ); Wed, 27 Nov 2013 12:56:46 -0500 Received: from terminus.zytor.com ([198.137.202.10]:50362 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752799Ab3K0R4p (ORCPT ); Wed, 27 Nov 2013 12:56:45 -0500 Message-ID: <52963223.9080701@zytor.com> Date: Wed, 27 Nov 2013 09:55:47 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Ingo Molnar , Kees Cook CC: LKML , Nicolas Pitre , Ingo Molnar , Russell King , Thomas Gleixner , "x86@kernel.org" , Shawn Guo , Olof Johansson , "linux-arm-kernel@lists.infradead.org" , Linus Torvalds , Andrew Morton Subject: Re: [PATCH v2] use -fstack-protector-strong References: <20131126203727.GA352@www.outflux.net> <20131127112731.GA10435@gmail.com> <20131127175442.GA28088@gmail.com> In-Reply-To: <20131127175442.GA28088@gmail.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/27/2013 09:54 AM, Ingo Molnar wrote: >> >> Looks to be 2% for defconfig. That's way better. Shall I send a v3? > > Well, it's better than 9%, but still almost an order of magnitude > higher than the cost is today, and a lot of distros have > CONFIG_CC_STACKPROTECTOR=y. > > So it would be nice to measure how much the instruction count goes up > in some realistic system-bound test. How much does something like > kernel/built-in.o increase, as per 'size' output? > Do we need CONFIG_CC_STACKPROTECTOR_STRONG? -hpa