Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935844Ab3DHM3B (ORCPT ); Mon, 8 Apr 2013 08:29:01 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:44163 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935007Ab3DHM27 (ORCPT ); Mon, 8 Apr 2013 08:28:59 -0400 Message-ID: <5162B7FF.7010603@canonical.com> Date: Mon, 08 Apr 2013 14:28:47 +0200 From: Stefan Bader User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: Borislav Petkov , Ingo Molnar , Andrea Arcangeli , Linux Kernel Mailing List , Andrew Morton , Andy Whitcroft , Mel Gorman Subject: Re: x86/mm/pageattr: Code without effect? References: <515E92CE.2000509@canonical.com> <20130405142104.GB29290@pd.tnic> <20130406145804.GJ3423@redhat.com> <20130406154751.GB3612@pd.tnic> <20130408115344.GA7513@gmail.com> <20130408115959.GB4395@pd.tnic> In-Reply-To: <20130408115959.GB4395@pd.tnic> X-Enigmail-Version: 1.4.6 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="------------enig8DBCC990AE501458D21073D6" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3478 Lines: 93 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig8DBCC990AE501458D21073D6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 08.04.2013 13:59, Borislav Petkov wrote: > On Mon, Apr 08, 2013 at 01:53:44PM +0200, Ingo Molnar wrote: >> >> * Borislav Petkov wrote: >> >>>> have been the source of the confusion. Remove the noop initializatio= n >>>> accordingly. >>>> >>>> Signed-off-by: Andrea Arcangeli >>> >>> Yeah, looks good to me. I've folded it into my pile of changes touchi= ng this and=20 >>> there are no visible issues. [...] >> >> Logistics question: is this fix coming upstream-wards via your pile of= changes=20 >> anytime soon? >=20 > Actually I was thinking Andrea would send it since it is his fix. And > besides, my pile is still stinking. :-) >=20 > AFAICT, the patch fixes a noop so the current code works anyway - IOW, > it is basically a code correctness fix which doesn't have any other > effect. What I mean by that is, no need to go in now for 3.9 and stable= =2E >=20 > Long story, short: best it would be, IMO, if Andrea would send it to > you soonish but you apply it for 3.10 so that it sees a whole cycle of > testing just in case - it is CPA code after all. To me it would read as someone or something may use change page attribute= to set PSE or GLOBAL (or any or the masked off bits from canon_pgprot) in an une= xpected way for a huge page as long as it is not split. As Boris says, it has not happened as far as it is known. Probably even i= f it happens it is one of those "on the right day of week when the phase of th= e moon is right" errors... To enforce the PSE bit here sounds reasonably right. And also apply canon_pgprot, too. GLOBAL I don't know for sure. By the way there is a usage of new_prot a bit down of try_preserve_large_= page which probably should be changed into req_prot, too. That was enforcing t= he canon_pgprot before the change. So that may be considered a regression to= before. -Stefan >=20 > Thanks. >=20 --------------enig8DBCC990AE501458D21073D6 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with undefined - http://www.enigmail.net/ iQIcBAEBCgAGBQJRYrf/AAoJEOhnXe7L7s6jHPMP/2aEmMFpiXx82WCQPrl6Sz3h 6ACADTSDcD3wbzEgGqAqBDP938tC4ACFXxMMXfUdlDQezIcKb5Q/ixg6XyPH6FJt BZsNrw6n6nWBhJn7Ex8B0cyRO9SQM+UC28PX+kUah6sNSVIw6iqbPhfTjckwNwcp ynABKRQKzMLWYGFY7uBz0yvvtcvv1oiuEc6srXVYPKCYpibv1Nfh+/LhGdGQzQU8 4wzvrOUWkAGKeQ5P7/xcOMA7mMCfYEgULDo2X8vUsD+V66UHTk62BVb+c2HrrSld oJbC8y5R3pQPK2+NRfQFraCke7/KqB0am49EGdPFxLzSG9moGRIAzap4s+d4e3b2 poM45Q/g/3V0wd7DSlNGavzZvxox0ulw0tUwUDbL/ti8Ryn/nAeKDtsc/Aw+mDwl HulsaiUiTwCYIzYLzDTG4iDPQ0cSXPcJMQZ4f/7b+2CQ5t26Nigj5ZB6gIQYcPYD oncqnEOuhKNPo/D0B2wyxxwXEu/7L5JPYe782lhE+90SDdD5iUK7Hj5BNSs6V7Gx qbgSxH2Rg/y/ShMN3tYFU05C3VYFt2Y17XoFKJIygtBAXC+flFuybm3A91AZ7jRX J+n5SMtbhdCPY4fDEnGBr67wMJJdoMYTQuvirUkqTOskd9PI0YxOjxDO4J6xCB+j tswIqkBUAt+MH1MPJI4Y =VxOT -----END PGP SIGNATURE----- --------------enig8DBCC990AE501458D21073D6-- -- 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/