Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753318AbcCLSOQ (ORCPT ); Sat, 12 Mar 2016 13:14:16 -0500 Received: from mail-ob0-f169.google.com ([209.85.214.169]:33694 "EHLO mail-ob0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750782AbcCLSOA (ORCPT ); Sat, 12 Mar 2016 13:14:00 -0500 MIME-Version: 1.0 In-Reply-To: References: <06079088639eddd756e2092b735ce4a682081308.1457486598.git.luto@kernel.org> From: Andy Lutomirski Date: Sat, 12 Mar 2016 10:13:39 -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: 1087 Lines: 25 On Wed, Mar 9, 2016 at 1:19 PM, Andy Lutomirski wrote: > 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. Nope, that version was also not okay. But the version currently in that branch has survived the kbuild bot for a while now. Yikes our build process for usermode code sucks. --Andy