From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) by kanga.kvack.org (Postfix) with ESMTP id 9F1656B0008 for ; Tue, 24 Jul 2018 18:03:03 -0400 (EDT) Received: by mail-ed1-f72.google.com with SMTP id b9-v6so2209271edn.18 for ; Tue, 24 Jul 2018 15:03:03 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id v9-v6si4026386edl.190.2018.07.24.15.03.02 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 24 Jul 2018 15:03:02 -0700 (PDT) Date: Wed, 25 Jul 2018 00:02:55 +0200 (CEST) From: Jiri Kosina Subject: Re: [RESEND] Spectre-v2 (IBPB/IBRS) and SSBD fixes for 4.4.y In-Reply-To: Message-ID: References: <153156030832.10043.13438231886571087086.stgit@srivatsa-ubuntu> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: "Srivatsa S. Bhat" Cc: gregkh@linuxfoundation.org, stable@vger.kernel.org, Denys Vlasenko , Bo Gan , Konrad Rzeszutek Wilk , Borislav Petkov , Thomas Gleixner , Ricardo Neri , Tom Lendacky , Andi Kleen , linux-tip-commits@vger.kernel.org, Jia Zhang , Josh Poimboeuf , xen-devel@lists.xenproject.org, =?ISO-8859-2?Q?Kr=E8m=E1=F8?= , Peter Zijlstra , Andy Lutomirski , Arnaldo Carvalho de Melo , Sherry Hurwitz , Kees Cook , linux-kernel@vger.kernel.org, Shuah Khan , Oleg Nesterov , Linus Torvalds , David Woodhouse , KarimAllah Ahmed , Borislav Petkov , Dave Hansen , linux@dominikbrodowski.net, Quentin Casasnovas , Joerg Roedel , Alexander Shishkin , Kyle Huey , Will Drewry , Andrey Ryabinin , "H. Peter Anvin" , Brian Gerst , Kristen Carlson Accardi , Thomas Garnier , Andrew Morton , Joe Konno , kvm , Piotr Luc , Boris Ostrovsky , Jan Beulich , Arjan van de Ven , Alexander Kuleshov , Juergen Gross , Ross Zwisler , =?ISO-8859-15?Q?J=F6rg_Otte?= , Tim Chen , Alexander Sergeyev , Josh Triplett , gnomes@lxorguk.ukuu.org.uk, Tony Luck , Laura Abbott , Dave Hansen , Ingo Molnar , Mike Galbraith , Rik van Riel , "Kirill A. Shutemov" , Alexey Makhalov , Dave Hansen , ashok.raj@intel.com, Mel Gorman , =?ISO-8859-15?Q?Micka=EBlSala=FCn?= , Fenghua Yu , "Matt Helsley (VMware)" , Vince Weaver , Prarit Bhargava , Steven Rostedt , Dan Williams , Jim Mattson , gregkh@linux-foundation.org, Dave Young , linux-edac , Jon Masters , Andy Lutomirski , Paolo Bonzini , Arnd Bergmann , linux-mm@kvack.org, Jiri Olsa , arjan.van.de.ven@intel.com, sironi@amazon.de, Frederic Weisbecker , Kyle Huey , Alexander Popov , Andy Shevchenko , Nadav Amit , Yazen Ghannam , Wanpeng Li , Stephane Eranian , David Woodhouse , srivatsab@vmware.com On Tue, 24 Jul 2018, Srivatsa S. Bhat wrote: > However, if you are proposing that you'd like to contribute the enhanced > PTI/Spectre (upstream) patches from the SLES 4.4 tree to 4.4 stable, and > have them merged instead of this patch series, then I would certainly > welcome it! I'd in principle love us to push everything back to 4.4, but there are a few reasons (*) why that's not happening shortly. Anyway, to point out explicitly what's really needed for those folks running 4.4-stable and relying on PTI providing The Real Thing(TM), it's either a 4.4-stable port of http://kernel.suse.com/cgit/kernel-source/plain/patches.suse/x86-entry-64-use-a-per-cpu-trampoline-stack.patch?id=3428a77b02b1ba03e45d8fc352ec350429f57fc7 or making THREADINFO_GFP imply __GFP_ZERO. (*) IBRS is not upstream, we historically have had very different x86 codebase compared to either 4.4, 4.4-stable or current Linus' tree, and there are simply too many things happening right now to give this high enough priority, sadly. We're not fully-dependent downstream consumer of -stable any more, so this is one of the expected outcomes, unfortunately; we don't immediately benefit from pushing our downstream changes to stable, as we have to carry those over forward ourselves anyway. Thanks, -- Jiri Kosina SUSE Labs