Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753481Ab2HCLT3 (ORCPT ); Fri, 3 Aug 2012 07:19:29 -0400 Received: from mail-gh0-f174.google.com ([209.85.160.174]:49116 "EHLO mail-gh0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753409Ab2HCLTZ (ORCPT ); Fri, 3 Aug 2012 07:19:25 -0400 MIME-Version: 1.0 In-Reply-To: <20120803110247.GB11952@moon> References: <20120323190855.GA27213@www.outflux.net> <87pq7935w2.fsf@xmission.com> <20120803110247.GB11952@moon> Date: Fri, 3 Aug 2012 13:19:24 +0200 Message-ID: Subject: Re: [PATCH v2] futex: mark get_robust_list as deprecated From: richard -rw- weinberger To: Cyrill Gorcunov Cc: Pavel Emelyanov , "Eric W. Biederman" , Kees Cook , Thomas Gleixner , linux-kernel@vger.kernel.org, Randy Dunlap , Darren Hart , Peter Zijlstra , Andrew Morton , Jiri Kosina , David Howells , "Serge E. Hallyn" , linux-doc@vger.kernel.org, kernel-hardening@lists.openwall.com, spender@grsecurity.net Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1674 Lines: 40 On Fri, Aug 3, 2012 at 1:02 PM, Cyrill Gorcunov wrote: >> >> I'm using this system call in an application and noticed that's marked >> >> as deprecated now. >> >> My application collects all kind of information from crashing programs. >> >> It's installed in /proc/sys/kernel/core_pattern. >> >> >> >> If program X is crashing it executes get_robust_list(X) to get the >> >> address of the robust list >> >> and reads the list from /proc/X/mem. >> >> >> >> Is there another way to get the robust list from another program (by it's pid)? >> > >> > The folks doing checkpoint/restart claim to not need this, so there >> > might be a way either that or they just haven't hit this problem yet. >> > >> > What you are doing sounds like a reasonable use of get_robust_list to me. >> > >> >> CRIU folks, how do you deal with futex robust lists? > > Well, I believe we were over-optimistic in claiming that we don't need this > syscall (to be fair I think we simply yet not faced the problem Eric points). > So we need some way to fetch this address and set it back. If get_robust_list > get deprecated maybe we could print it out in /proc/pid/stat or something? Kees, you said get_robust_list() can be used to bypass ASLR. How? What makes it worse than /proc/pid/maps? If the robust list address itself is bad, removing get_robust_list() and putting the information into /proc is useless. -- Thanks, //richard -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/