From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932163AbbJRQrL (ORCPT ); Sun, 18 Oct 2015 12:47:11 -0400 Received: from fallback8.mail.ru ([94.100.181.110]:47024 "EHLO fallback8.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932081AbbJRQrJ (ORCPT ); Sun, 18 Oct 2015 12:47:09 -0400 Subject: Re: [RFC 3/4] x86/signal/64: Re-add support for SS in the 64-bit signal context To: Andy Lutomirski References: <6e14e2f7ce1c38fc1996bd4d5d3d9dc70b8bd94d.1444697927.git.luto@kernel.org> <561D1C53.8080302@list.ru> <561E93A9.3030500@list.ru> <561EA021.9060901@list.ru> <561ECB36.8050003@list.ru> <5623A072.9000100@list.ru> <5623C8CF.4020405@list.ru> Cc: Denys Vlasenko , Pavel Emelyanov , Borislav Petkov , "linux-kernel@vger.kernel.org" , Cyrill Gorcunov , Brian Gerst , X86 ML , Linus Torvalds From: Stas Sergeev Message-ID: <5623CC44.9030202@list.ru> Date: Sun, 18 Oct 2015 19:43:48 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 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 18.10.2015 19:36, Andy Lutomirski пишет: > On Sun, Oct 18, 2015 at 9:29 AM, Stas Sergeev wrote: >> 18.10.2015 19:12, Andy Lutomirski пишет: >>> On Sun, Oct 18, 2015 at 6:36 AM, Stas Sergeev wrote: >>>> 15.10.2015 00:41, Andy Lutomirski пишет: >>>>>> If this my >>>>>> understanding is correct and the flag is just an indication rather >>>>>> than a requested action, perhaps the name should be different, >>>>>> e.g. UC_SIG_FROM_32BIT or the like? >>>>>> Anyway, this is minor. :) >>>>>> I'll try to test the patch within a few days, thanks for you time! >>>>> No problem. Thanks for being willing to test! >>>> Hello Andy, I am unlucky at testing this. >>>> dosemu doesn't even start for me on the git kernels. >>>> After a half day of debugging, it seems the kernel forgets >>>> to fill in the "err" field in the sigcontext struct when >>>> page fault occurs. That confuses the dosemu's instruction >>>> decoder. >>>> Does this ring any bells? >>> No, but I can reproduce it on some kernels. Let me see if I can fix it, >>> too. >> Thanks! >> You should really consider adding dosemu as your test-case. >> It feels very unhappy on all recent kernels. I was getting hard >> lock-ups under different circumstances (when starting windows, >> for example). But fedora-packaged kernels are quite good, as of >> yet. I fear the problems will soon populate to them too. > I'll work on that. It's a lot easier to have a packaged set of tests > that say yes/no, though, and it's handy when those tests are fully > open-source and easy to run (DOSEMU, in contrast, requires the > annoyingly impossible-to-compile freedos stuff iirc, and the > interesting bits need other test programs). In any case, I'll add a > self-test for the > err thing once I figure out what's going on. I meant just a local test-case on your PC. :) It can't be a part of an automated test-suit of course. But after changing anything in vm86 or signal handling, running dosemu will never hurt, as it is probably the most rigorous test-case for them. I deduce that based on its breakage frequency with the kernel updates.