From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752374AbbHRG34 (ORCPT ); Tue, 18 Aug 2015 02:29:56 -0400 Received: from smtp13.mail.ru ([94.100.181.94]:33005 "EHLO smtp13.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752214AbbHRG3z (ORCPT ); Tue, 18 Aug 2015 02:29:55 -0400 Subject: Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu To: Brian Gerst , Andy Lutomirski References: <55CA90B4.2010205@list.ru> Cc: Linux kernel From: Stas Sergeev Message-ID: <55D2D0DE.3080707@list.ru> Date: Tue, 18 Aug 2015 09:29:50 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Mras: Ok Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 13.08.2015 20:00, Brian Gerst пишет: > On Thu, Aug 13, 2015 at 11:43 AM, Andy Lutomirski wrote: >> On Thu, Aug 13, 2015 at 8:37 AM, Linus Torvalds >> wrote: >>> On Tue, Aug 11, 2015 at 5:17 PM, Stas Sergeev wrote: >>>> I realize this patch may be good to have in general, but >>>> breaking userspace without a single warning is a bit >>>> discouraging. Seems like the old "we don't break userspace" >>>> rule have gone. >>> That rule hasn't gone anywhere. >>> >>> Does a plain revert just fix everything? Because if so, that's the >>> right thing to do, and we can just re-visit this later. >>> >>> I don't understand why Andy and Ingo are even discussing this. What >>> the f*ck, guys? >>> >> I'm trying to fix it without reverting. If that doesn't work, then we >> revert. Yesterday, I thought I had a reasonably clean fix, but it >> turned out that it only solved half of the problem. >> >> If we revert, I think I need to check what will break due to the >> revert. I need to check at least Wine, and we'll have to do something >> about all the selftests that will start failing. I also need to check >> CRIU, and IIRC CRIU has started using the new sigcontext SS in new >> versions. > I don't think Wine will be a problem, at least how it is currently set > up. 16-bit support is only in the 32-bit build. The 64-bit build > only supports Win64 apps, and will call the 32-bit version (installed > in parallel) to run 32 and 16-bit apps. Is this also because of the lack of the proper 32/16bit support in a 64bit kernels? If so, dosemu's work-arounds do not look like the too bad thing compared to that. :)