From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id A06126B0003 for ; Thu, 15 Feb 2018 08:25:18 -0500 (EST) Received: by mail-pg0-f71.google.com with SMTP id m3so3917955pgd.20 for ; Thu, 15 Feb 2018 05:25:18 -0800 (PST) Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTPS id f20-v6si2996142plj.254.2018.02.15.05.25.17 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 15 Feb 2018 05:25:17 -0800 (PST) Subject: [PATCH 0/3] Use global pages with PTI From: Dave Hansen Date: Thu, 15 Feb 2018 05:20:53 -0800 Message-Id: <20180215132053.6C9B48C8@viggo.jf.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Dave Hansen , luto@kernel.org, torvalds@linux-foundation.org, keescook@google.com, hughd@google.com, jgross@suse.com, x86@kernel.org The later verions of the KAISER pathces (pre-PTI) allowed the user/kernel shared areas to be GLOBAL. The thought was that this would reduce the TLB overhead of keeping two copies of these mappings. During the switch over to PTI, we seem to have lost our ability to have GLOBAL mappings. This adds them back. Did we have some reason for leaving out global pages entirely? We _should_ have all the TLB flushing mechanics in place to handle these already since all of our kernel mapping changes have to know how to flush global pages regardless. Cc: Andy Lutomirski Cc: Linus Torvalds Cc: Kees Cook Cc: Hugh Dickins Cc: Juergen Gross Cc: x86@kernel.org -- 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