Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933723AbbENSkf (ORCPT ); Thu, 14 May 2015 14:40:35 -0400 Received: from mail-la0-f44.google.com ([209.85.215.44]:35815 "EHLO mail-la0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933511AbbENSkb (ORCPT ); Thu, 14 May 2015 14:40:31 -0400 MIME-Version: 1.0 In-Reply-To: References: <20150512090156.24768.2521.stgit@buzz> Date: Thu, 14 May 2015 19:40:30 +0100 Message-ID: Subject: Re: [PATCH RFC 0/3] pagemap: make useable for non-privilege users From: Mark Williamson To: Konstantin Khlebnikov Cc: linux-mm@kvack.org, Naoya Horiguchi , kernel list , Andrew Morton , Pavel Emelyanov , Linux API , Andy Lutomirski , Vlastimil Babka , Pavel Machek , Mark Seaborn , "Kirill A. Shutemov" , Linus Torvalds , Daniel James , Finn Grimwood Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2079 Lines: 54 Hi Konstantin, I modified our code to check for the map-exclusive flag where it used to compare pageframe numbers. First tests look pretty promising, so this patch looks like a viable approach for us. Is there anything further we can do to help? Thanks, Mark On Tue, May 12, 2015 at 12:13 PM, Mark Williamson wrote: > Hi Konstantin, > > Thanks very much for continuing to look at this! It's very much > appreciated. I've been investigating from our end but got caught up > in some gnarly details of our pagemap-consuming code. > > I like the approach and it seems like the information you're exposing > will be useful for our application. I'll test the patch and see if it > works for us as-is. > > Will follow up with any comments on the individual patches. > > Thanks, > Mark > > On Tue, May 12, 2015 at 10:43 AM, Konstantin Khlebnikov > wrote: >> This patchset tries to make pagemap useable again in the safe way. >> First patch adds bit 'map-exlusive' which is set if page is mapped only here. >> Second patch restores access for non-privileged users but hides pfn if task >> has no capability CAP_SYS_ADMIN. Third patch removes page-shift bits and >> completes migration to the new pagemap format (flags soft-dirty and >> mmap-exlusive are available only in the new format). >> >> --- >> >> Konstantin Khlebnikov (3): >> pagemap: add mmap-exclusive bit for marking pages mapped only here >> pagemap: hide physical addresses from non-privileged users >> pagemap: switch to the new format and do some cleanup >> >> >> Documentation/vm/pagemap.txt | 3 - >> fs/proc/task_mmu.c | 178 +++++++++++++++++------------------------- >> tools/vm/page-types.c | 35 ++++---- >> 3 files changed, 91 insertions(+), 125 deletions(-) -- 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/