From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f198.google.com (mail-wr0-f198.google.com [209.85.128.198]) by kanga.kvack.org (Postfix) with ESMTP id 4C90D6B029D for ; Tue, 16 Jan 2018 16:06:53 -0500 (EST) Received: by mail-wr0-f198.google.com with SMTP id 31so1771935wri.9 for ; Tue, 16 Jan 2018 13:06:53 -0800 (PST) Received: from Galois.linutronix.de (Galois.linutronix.de. [2a01:7a0:2:106d:700::1]) by mx.google.com with ESMTPS id o204si2402985wma.183.2018.01.16.13.06.52 for (version=TLS1_2 cipher=AES128-SHA bits=128/128); Tue, 16 Jan 2018 13:06:52 -0800 (PST) Date: Tue, 16 Jan 2018 22:06:48 +0100 (CET) From: Thomas Gleixner Subject: Re: [PATCH 10/16] x86/mm/pti: Populate valid user pud entries In-Reply-To: <1516120619-1159-11-git-send-email-joro@8bytes.org> Message-ID: References: <1516120619-1159-1-git-send-email-joro@8bytes.org> <1516120619-1159-11-git-send-email-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Joerg Roedel Cc: Ingo Molnar , "H . Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Linus Torvalds , Andy Lutomirski , Dave Hansen , Josh Poimboeuf , Juergen Gross , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , Brian Gerst , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , Will Deacon , aliguori@amazon.com, daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, Andrea Arcangeli , Waiman Long , jroedel@suse.de On Tue, 16 Jan 2018, Joerg Roedel wrote: > From: Joerg Roedel > > With PAE paging we don't have PGD and P4D levels in the > page-table, instead the PUD level is the highest one. > > In PAE page-tables at the top-level most bits we usually set > with _KERNPG_TABLE are reserved, resulting in a #GP when > they are loaded by the processor. > > Work around this by populating PUD entries in the user > page-table only with _PAGE_PRESENT set. > > I am pretty sure there is a cleaner way to do this, but > until I find it use this #ifdef solution. Stick somehting like #define _KERNELPG_TABLE_PUD_ENTRY into the 32 and 64 bit variants of some relevant header file Thanks, tglx -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org