Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934191AbcCIVUJ (ORCPT ); Wed, 9 Mar 2016 16:20:09 -0500 Received: from mail-oi0-f54.google.com ([209.85.218.54]:35825 "EHLO mail-oi0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932504AbcCIVUG (ORCPT ); Wed, 9 Mar 2016 16:20:06 -0500 MIME-Version: 1.0 In-Reply-To: References: <06079088639eddd756e2092b735ce4a682081308.1457486598.git.luto@kernel.org> From: Andy Lutomirski Date: Wed, 9 Mar 2016 13:19:45 -0800 Message-ID: Subject: Re: [RFC PATCH] x86/vdso/32: Add AT_SYSINFO cancellation helpers To: Andy Lutomirski Cc: X86 ML , "linux-kernel@vger.kernel.org" , Borislav Petkov , "musl@lists.openwall.com" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 811 Lines: 19 On Wed, Mar 9, 2016 at 9:58 AM, Andy Lutomirski wrote: > On Tue, Mar 8, 2016 at 5:24 PM, Andy Lutomirski wrote: >> musl implements system call cancellation in an unusual but clever way. >> When a thread issues a cancellable syscall, musl issues the syscall >> through a special thunk that looks roughly like this: >> > > FWIW, this patch fails disastrously on 64-bit kernels. I fixed it, > but it needs kbuild changes. I'll send those out to the maintainers. This version should be okay: https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git/commit/?h=x86/vdso&id=fed6d35d3941bc53896ab80b5c8d68d54cc00347 You'll need the parent, too, if you want to test. I'm going to give the 0day bot a good long chew, since the parent change is a little bit scary. --Andy