From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5CC95C433FE for ; Tue, 29 Mar 2022 15:50:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CA2ED8D0002; Tue, 29 Mar 2022 11:50:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C52588D0001; Tue, 29 Mar 2022 11:50:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AF3CD8D0002; Tue, 29 Mar 2022 11:50:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id A1ECD8D0001 for ; Tue, 29 Mar 2022 11:50:08 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay12.hostedemail.com (Postfix) with ESMTP id 6CA9B12165F for ; Tue, 29 Mar 2022 15:50:08 +0000 (UTC) X-FDA: 79297860096.02.6C9E11A Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) by imf29.hostedemail.com (Postfix) with ESMTP id 39D10120009 for ; Tue, 29 Mar 2022 15:50:07 +0000 (UTC) Received: from imladris.surriel.com ([96.67.55.152]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1nZE6V-0004sG-4e; Tue, 29 Mar 2022 11:49:55 -0400 Message-ID: <47936edb3b0f9c9f04f0d0d2e7f38383a22b6a3d.camel@surriel.com> Subject: Re: [PATCH] mm,hwpoison: unmap poisoned page before invalidation From: Rik van Riel To: Oscar Salvador Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-team@fb.com, Miaohe Lin , Naoya Horiguchi , Mel Gorman , Johannes Weiner , Andrew Morton , stable@vger.kernel.org Date: Tue, 29 Mar 2022 11:49:53 -0400 In-Reply-To: References: <20220325161428.5068d97e@imladris.surriel.com> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-1nbVtLEU+9mQSE0QbNkg" User-Agent: Evolution 3.42.4 (3.42.4-1.fc35) MIME-Version: 1.0 X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 39D10120009 X-Rspam-User: Authentication-Results: imf29.hostedemail.com; dkim=none; dmarc=none; spf=none (imf29.hostedemail.com: domain of riel@shelob.surriel.com has no SPF policy when checking 96.67.55.147) smtp.mailfrom=riel@shelob.surriel.com X-Stat-Signature: 5a4e6w3wqqd75aoupaxq5eg81d9f4oqw X-HE-Tag: 1648569007-528988 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000030, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: --=-1nbVtLEU+9mQSE0QbNkg Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2022-03-28 at 11:00 +0200, Oscar Salvador wrote: > On Fri, Mar 25, 2022 at 04:14:28PM -0400, Rik van Riel wrote: > > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0if (in= validate_inode_page(page)) > > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0poisonret =3D VM_FAULT_NOPAGE; >=20 > What is the effect of returning VM_FAULT_NOPAGE? > I take that we are cool because the pte has been installed and points > to > a new page? (I could not find where that is being done). >=20 It results in us returning to userspace as if the page fault had been handled, resulting in a second fault on the same address. However, now the page is no longer in the page cache, and we can read it in from disk, to a page that is not hardware poisoned, and we can then use that second page without issues. --=20 All Rights Reversed. --=-1nbVtLEU+9mQSE0QbNkg Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEKR73pCCtJ5Xj3yADznnekoTE3oMFAmJDKqEACgkQznnekoTE 3oPaQwgAjpAAjbiuOWl9S6LuGLV7gTR6piiEa7NFUs+d/D8ndjxb0ImtJrHrTF4b 3YO9bln7laVN1+jACN/9FfGQh7YobgviPQ3HJc0bkdxHC1eMrwIEA3n02e1RaZ6Z x5Z14n2+DretUQs8O9CFDR5ioV36yWFpe0VKFlcMik20SDdaE3pbATgHvCnXb8nl NOJcnP95djsEgLMSmSFlBE2EpEF9e1MyYfHF1RVqnNm4KljTEjCouPbiuBU/y/kR 5Wsc8fVZaDSVNKFVM4GCdzBqziwCdYsAaPemPMTO5D9jWrA6f1wudmIKNiO6B1+X KE2keqO/4AXE0JZc/m+f4157Owu0dA== =9sBD -----END PGP SIGNATURE----- --=-1nbVtLEU+9mQSE0QbNkg--