From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932234AbbIBVHw (ORCPT ); Wed, 2 Sep 2015 17:07:52 -0400 Received: from smtp15.mail.ru ([94.100.176.133]:58424 "EHLO smtp15.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754914AbbIBVHv (ORCPT ); Wed, 2 Sep 2015 17:07:51 -0400 Subject: Re: stop breaking dosemu (Re: x86/kconfig/32: Rename CONFIG_VM86 and default it to 'n') To: Andy Lutomirski References: <55E6C36F.6080309@list.ru> <55E736E9.2000201@list.ru> <55E7607B.4070800@list.ru> Cc: Josh Boyer , "linux-kernel@vger.kernel.org" , "Andrew Bird (Sphere Systems)" , Linus Torvalds , Ingo Molnar , Kees Cook , Brian Gerst From: Stas Sergeev Message-ID: <55E7663B.30402@list.ru> Date: Thu, 3 Sep 2015 00:12:27 +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 02.09.2015 23:55, Andy Lutomirski пишет: > On Wed, Sep 2, 2015 at 1:47 PM, Stas Sergeev wrote: >> 02.09.2015 23:22, Josh Boyer пишет: >>> On Wed, Sep 2, 2015 at 1:50 PM, Stas Sergeev wrote: >>>> 02.09.2015 20:46, Josh Boyer пишет: >>>>> On Wed, Sep 2, 2015 at 10:08 AM, Andy Lutomirski >>>>> wrote: >>>>>> I'd be amenable to switching the default back to y and perhaps adding >>>>>> a sysctl to make the distros more comfortable. Ingo, Kees, Brian, >>>>>> what do you think? >>>>> Can you please leave the default as N, and have a sysctl option to >>>>> enable it instead? While dosemu might still be in use, it isn't going >>>>> to be the common case at all. So from a distro perspective, I think >>>>> we'd probably rather have the default match the common case. >>>> The fact that fedora doesn't package dosemu, doesn't automatically >>>> mean all other distros do not too. Since when kernel defaults should >>>> match the ones of fedora? >>> I didn't say that. >> What you said was: >> --- >> >> While dosemu might still be in use, it isn't going >> to be the common case at all. So from a distro perspective >> >> --- >> ... which is likely true only in fedora circe. >> >>> The default right now is N. >> In a not yet released kernel, unless I am mistaken. >> If fedora already provides that kernel, other distros likely not. >> >>> I asked it be left >>> that way. That's all. >> Lets assume its not yet N, unless there was a kernel release already. >> Its easy to get back if its not too late. > How about CONFIG_SYSCTL_VM86_DEFAULT which defaults to Y? Fedora > could set it to N. Sorry, I don't understand this sysctl proposal. Could you please educate me what is it all about? This sysctl will disable or enable the vm86() syscall at run-time, right? What does it give us? If you disable something in the config, this gives you, say, smaller kernel image. If OTOH you add the run-time switch, it gives you a bigger image, regardless of its default value. I might be missing something, but I don't understand what problem will this solve? Have I missed some earlier message in this thread?