From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932121AbZACWod (ORCPT ); Sat, 3 Jan 2009 17:44:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755979AbZACWoZ (ORCPT ); Sat, 3 Jan 2009 17:44:25 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:36392 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753134AbZACWoY (ORCPT ); Sat, 3 Jan 2009 17:44:24 -0500 Date: Sat, 3 Jan 2009 23:44:08 +0100 From: Ingo Molnar To: Arjan van de Ven Cc: Linus Torvalds , linux-kernel@vger.kernel.org, Andrew Morton , "H. Peter Anvin" , Thomas Gleixner Subject: Re: [git pull] stackprotector re-enabling patches Message-ID: <20090103224408.GC17047@elte.hu> References: <20090103214353.GA22949@elte.hu> <20090103135513.20f14f1d@infradead.org> <20090103143455.4c23d243@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090103143455.4c23d243@infradead.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Arjan van de Ven wrote: > On Sat, 3 Jan 2009 13:55:13 -0800 > Arjan van de Ven wrote: > > > On Sat, 3 Jan 2009 22:43:53 +0100 > > Ingo Molnar wrote: > > > > > > diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug > > > index 10d6cc3..28f1114 100644 > > > --- a/arch/x86/Kconfig.debug > > > +++ b/arch/x86/Kconfig.debug > > > @@ -117,6 +117,7 @@ config DEBUG_RODATA > > > config DEBUG_RODATA_TEST > > > bool "Testcase for the DEBUG_RODATA feature" > > > depends on DEBUG_RODATA > > > + default y > > > help > > > This option enables a testcase for the DEBUG_RODATA > > > feature as well as for the change_page_attr() > > > > I think this chunk isn't meant to be there... > > actually never mind. > it does make sense in general (in fact, I'd be tempted to remove the > KConfig for this one and just always do the check) yes. The reason why this change went into the stackprotector tree was because it was the same pattern: security feature breaking because it didnt have efficient self-tests - while attackers obviously never notified us that it's broken. DEBUG_RODATA had similar bugs: it didnt work correctly in some cases and nothing really tested that so we had long latency of bugs. So i turned on that self-test too. [and that did catch some bugs, which you fixed, many moons ago ;-) ] Ingo