From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754461AbcAVTPD (ORCPT ); Fri, 22 Jan 2016 14:15:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46620 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752220AbcAVTO5 (ORCPT ); Fri, 22 Jan 2016 14:14:57 -0500 Date: Fri, 22 Jan 2016 13:14:47 -0600 From: Josh Poimboeuf To: Chris J Arges Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, Michal Marek , Peter Zijlstra , Andy Lutomirski , Borislav Petkov , Linus Torvalds , Andi Kleen , Pedro Alves , Namhyung Kim , Bernd Petrovitsch , Andrew Morton , Jiri Slaby , Arnaldo Carvalho de Melo , David Vrabel , Borislav Petkov , Konrad Rzeszutek Wilk , Boris Ostrovsky , Jeremy Fitzhardinge , Chris Wright , Alok Kataria , Rusty Russell , Herbert Xu , "David S. Miller" , Pavel Machek , "Rafael J. Wysocki" , Len Brown , Matt Fleming , Alexei Starovoitov , netdev@vger.kernel.org, Ananth N Mavinakayanahalli , Anil S Keshavamurthy , Masami Hiramatsu , Gleb Natapov , Paolo Bonzini , kvm@vger.kernel.org, Wim Van Sebroeck , Guenter Roeck , linux-watchdog@vger.kernel.org, Waiman Long Subject: Re: [PATCH 00/33] Compile-time stack metadata validation Message-ID: <20160122191447.GH20502@treble.redhat.com> References: <20160122174348.GB29221@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20160122174348.GB29221@canonical.com> User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 22, 2016 at 11:43:48AM -0600, Chris J Arges wrote: > On Thu, Jan 21, 2016 at 04:49:04PM -0600, Josh Poimboeuf wrote: > > This is v16 of the compile-time stack metadata validation patch set, > > along with proposed fixes for most of the warnings it found. It's based > > on the tip/master branch. > > > Josh, > > Looks good, with my config [1] I do still get a few warnings building > linux/linux-next. > > Here are the warnings: > $ grep ^stacktool build.log | grep -v staging Thanks for reporting these! > stacktool: arch/x86/kvm/vmx.o: vmx_handle_external_intr()+0x67: call without frame pointer save/setup This can be fixed by setting the stack pointer as an output operand for the inline asm call in vmx_handle_external_intr(). Feel free to submit a patch, or I'll get around to it eventually. > stacktool: fs/reiserfs/namei.o: set_de_name_and_namelen()+0x9e: return without frame pointer restore > stacktool: fs/reiserfs/namei.o: set_de_name_and_namelen()+0x89: duplicate frame pointer save > stacktool: fs/reiserfs/namei.o: set_de_name_and_namelen()+0x8a: duplicate frame pointer setup > stacktool: fs/reiserfs/namei.o: set_de_name_and_namelen()+0x9e: frame pointer state mismatch > stacktool: fs/reiserfs/namei.o: set_de_name_and_namelen()+0x0: frame pointer state mismatch These are false positives. Stacktool is confused by the use of a "noreturn" function which it doesn't know about (__reiserfs_panic). Unfortunately the only solution I currently have for dealing with global noreturn functions is to just hard-code a list of them. So the short term fix would be to add "__reiserfs_panic" to the global_noreturns list in tools/stacktool/builtin-check.c. I'm still trying to figure out a better way to deal with this type of issue, as it's a pain to have to keep a hard-coded list of noreturn functions. Unfortunately that info isn't available in the ELF. > stacktool: fs/reiserfs/ibalance.o: .text: unexpected end of section > stacktool: fs/reiserfs/tail_conversion.o: .text: unexpected end of section For some reason I'm not able to recreate these warnings... Can you share one of the .o files? -- Josh