Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752054AbbGIJDs (ORCPT ); Thu, 9 Jul 2015 05:03:48 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:59343 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751525AbbGIJDa (ORCPT ); Thu, 9 Jul 2015 05:03:30 -0400 Date: Thu, 9 Jul 2015 11:03:28 +0200 From: Pavel Machek To: Thomas Gleixner Cc: Arjan van de Ven , Andy Lutomirski , x86@kernel.org, LKML , Oleg Nesterov , Kees Cook , Peter Zijlstra , Borislav Petkov , Linus Torvalds Subject: Re: [PATCH] x86/kconfig/32: Mark CONFIG_VM86 as BROKEN Message-ID: <20150709090327.GA16677@amd> References: <23d4709cee2fe92c32d41b99c7a3c1823725925a.1436312944.git.luto@kernel.org> <559C8BFE.6050604@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2426 Lines: 58 On Wed 2015-07-08 16:00:48, Thomas Gleixner wrote: > On Tue, 7 Jul 2015, Arjan van de Ven wrote: > > > On 7/7/2015 6:25 PM, Andy Lutomirski wrote: > > > VM86 is entirely broken if ptrace, syscall auditing, or NOHZ_FULL is > > > in use. The code is a big undocumented mess, it's a real PITA to > > > test, and it looks like a big chunk of vm86_32.c is dead code. It > > > also plays awful games with the entry asm. > > > > > > No one should be using it anyway. Use DOSBOX or KVM instead. > > > > > > Mark it BROKEN. I want to remove some (obviously incorrect) exit > > > asm that it depends on, and I don't want to figure out how to run > > > severely obsolete programs just to test something that no one uses > > > for anything other than exploits anyway. > > > > > > > while it is never great to deprecate features, in this case I am not sure > > there is another choice unless someone steps up to seriously revamp this code. > > (and look at it from a PREEMPT, NO_HZ etc etc angle) > > Aside of being broken in so many aspects it's even more obsolete than > 386 support, we should just remove it right away. Bad news for you: vbetool-0.5/lrmi.c:#include vbetool-0.5/lrmi.c:#include vbetool-0.5/lrmi.c:#include vbetool-0.5/lrmi.c: struct vm86_struct vm; vbetool-0.5/lrmi.c: struct vm86_init_args init; ... vbetool-0.5/lrmi.c:lrmi_vm86(struct vm86_struct *vm) vbetool-0.5/lrmi.c:#define lrmi_vm86 vm86 vbetool-0.5/lrmi.c: fputs("vm86() failed\n", stderr); vbetool-0.5/lrmi.c:run_vm86(void) vbetool-0.5/lrmi.c: vret = lrmi_vm86(&context.vm); vbetool-0.5/lrmi.c:vm86_callback(int sig, int code, struct sigcontext *sc) vbetool-0.5/lrmi.c:vm86_callback(int sig, int code, struct sigcontext *sc) vbetool-0.5/lrmi.c:run_vm86(void) vbetool-0.5/lrmi.c: fprintf(stderr, "run_vm86: callback already installed\n"); vbetool depends on it, and s2ram depends on vbetool. When we get proper kernel drivers, this one will be solved, but it is not "more obsolete than 386". Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/