Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751729AbaANNSB (ORCPT ); Tue, 14 Jan 2014 08:18:01 -0500 Received: from mail-pb0-f54.google.com ([209.85.160.54]:40864 "EHLO mail-pb0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751733AbaANNRz (ORCPT ); Tue, 14 Jan 2014 08:17:55 -0500 MIME-Version: 1.0 In-Reply-To: <20140114125153.GY7572@laptop.programming.kicks-ass.net> References: <20140114155331.88d170d3c991b9465c23a537@canb.auug.org.au> <20140114125153.GY7572@laptop.programming.kicks-ass.net> Date: Tue, 14 Jan 2014 14:17:55 +0100 X-Google-Sender-Auth: -kJqBQzm8M5hTulzUFff3VhHfsk Message-ID: Subject: Re: linux-next: manual merge of the akpm-current tree with the tip tree From: Geert Uytterhoeven To: Peter Zijlstra Cc: Stephen Rothwell , Andrew Morton , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Linux-Next , "linux-kernel@vger.kernel.org" , Davidlohr Bueso Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 14, 2014 at 1:51 PM, Peter Zijlstra wrote: > On Tue, Jan 14, 2014 at 03:53:31PM +1100, Stephen Rothwell wrote: >> Today's linux-next merge of the akpm-current tree got a conflict in >> kernel/futex.c between commit a52b89ebb6d4 ("futexes: Increase hash table >> size for better performance") from the tip tree and commit 61beee6c76e5 >> ("futex: switch to USER_DS for futex test") from the akpm-current tree. >> >> @@@ -2869,10 -2748,13 +2871,13 @@@ >> * implementation, the non-functional ones will return >> * -ENOSYS. >> */ >> + fs = get_fs(); >> + set_fs(USER_DS); >> if (cmpxchg_futex_value_locked(&curval, NULL, 0, 0) == -EFAULT) >> futex_cmpxchg_enabled = 1; >> + set_fs(fs); >> > > This seems terribly broken, the *futex_value*() ops should not need > that; they are supposed to access userspace without any of that. Why don't they need set_fs(USER_DS)? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- 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/