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 X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52611C433B4 for ; Fri, 16 Apr 2021 15:42:03 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 00AEF6137D for ; Fri, 16 Apr 2021 15:42:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 00AEF6137D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AB001900008; Fri, 16 Apr 2021 11:41:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A12CC900007; Fri, 16 Apr 2021 11:41:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7ED88900008; Fri, 16 Apr 2021 11:41:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0021.hostedemail.com [216.40.44.21]) by kanga.kvack.org (Postfix) with ESMTP id 603AA900007 for ; Fri, 16 Apr 2021 11:41:47 -0400 (EDT) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 1477C181D9039 for ; Fri, 16 Apr 2021 15:41:47 +0000 (UTC) X-FDA: 78038645454.11.A95993C Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by imf08.hostedemail.com (Postfix) with ESMTP id 1531880192C0 for ; Fri, 16 Apr 2021 15:41:30 +0000 (UTC) IronPort-SDR: dy8ShhUr0WePtTeiO++Wm2/LT/c58k4XBtXZDP3QyeO9iaEKeVVasMbikHe1X4kFkd54sc2BRK ZGr/EW4rGiHw== X-IronPort-AV: E=McAfee;i="6200,9189,9956"; a="215592506" X-IronPort-AV: E=Sophos;i="5.82,226,1613462400"; d="scan'208";a="215592506" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Apr 2021 08:41:44 -0700 IronPort-SDR: BiatwMA0y8qUcIW7/n3v5VFpxjtDSkQkoZb1k+sB1Z4cLkxVSZkRIORtiu9iZm6VdBUjhLkGV4 eMT6uG8NXbTQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,226,1613462400"; d="scan'208";a="422038787" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga007.jf.intel.com with ESMTP; 16 Apr 2021 08:41:38 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 41BE135E; Fri, 16 Apr 2021 18:41:50 +0300 (EEST) From: "Kirill A. Shutemov" To: Dave Hansen , Andy Lutomirski , Peter Zijlstra , Sean Christopherson , Jim Mattson Cc: David Rientjes , "Edgecombe, Rick P" , "Kleen, Andi" , "Yamahata, Isaku" , Erdem Aktas , Steve Rutherford , Peter Gonda , David Hildenbrand , x86@kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [RFCv2 11/13] mm: Replace hwpoison entry with present PTE if page got unpoisoned Date: Fri, 16 Apr 2021 18:41:04 +0300 Message-Id: <20210416154106.23721-12-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210416154106.23721-1-kirill.shutemov@linux.intel.com> References: <20210416154106.23721-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 1531880192C0 X-Stat-Signature: ieb674kebib8qcwmjn36j13z4ydqduf1 Received-SPF: none (linux.intel.com>: No applicable sender policy available) receiver=imf08; identity=mailfrom; envelope-from=""; helo=mga01.intel.com; client-ip=192.55.52.88 X-HE-DKIM-Result: none/none X-HE-Tag: 1618587690-644227 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: If the page got unpoisoned we can replace hwpoison entry with a present PTE on page fault instead of delivering SIGBUS. Signed-off-by: Kirill A. Shutemov --- mm/memory.c | 38 +++++++++++++++++++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) diff --git a/mm/memory.c b/mm/memory.c index b15b0c582186..56f93e8e98f9 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3280,7 +3280,43 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) vmf->page =3D device_private_entry_to_page(entry); ret =3D vmf->page->pgmap->ops->migrate_to_ram(vmf); } else if (is_hwpoison_entry(entry)) { - ret =3D VM_FAULT_HWPOISON; + page =3D hwpoison_entry_to_page(entry); + + locked =3D lock_page_or_retry(page, vma->vm_mm, vmf->flags); + if (!locked) { + ret =3D VM_FAULT_RETRY; + goto out; + } + + vmf->pte =3D pte_offset_map_lock(vma->vm_mm, vmf->pmd, + vmf->address, &vmf->ptl); + + if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte))) { + ret =3D 0; + } else if (PageHWPoison(page)) { + ret =3D VM_FAULT_HWPOISON; + } else { + /* + * The page is unpoisoned. Replace hwpoison + * entry with a present PTE. + */ + + inc_mm_counter(vma->vm_mm, mm_counter(page)); + pte =3D mk_pte(page, vma->vm_page_prot); + + if (PageAnon(page)) { + page_add_anon_rmap(page, vma, + vmf->address, false); + } else { + page_add_file_rmap(page, false); + } + + set_pte_at(vma->vm_mm, vmf->address, + vmf->pte, pte); + } + + pte_unmap_unlock(vmf->pte, vmf->ptl); + unlock_page(page); } else { print_bad_pte(vma, vmf->address, vmf->orig_pte, NULL); ret =3D VM_FAULT_SIGBUS; --=20 2.26.3