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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 4586EC12002 for ; Wed, 14 Jul 2021 22:25:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D7C7613C9 for ; Wed, 14 Jul 2021 22:25:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235744AbhGNW15 (ORCPT ); Wed, 14 Jul 2021 18:27:57 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:32085 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235716AbhGNW14 (ORCPT ); Wed, 14 Jul 2021 18:27:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626301503; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pgOZ+9IjwVfKb5tKhAxRusG1z8GoeGAv34cmBph/B3s=; b=fNWVSmgh45wBt2Cyt31RGD5DCfcx6EYGI+4Mbb50PiB6J6DCBKb5ErCWW187Q+j1bSz20W bIBgL8d3KpaMxObJpLMQj1UfhjDv0QDcrj31MqCwY8R9NiE9BU1IJ9ZkPxYg5RV2UpWsSA ZmdYsHqYbnsmwHY+FlaiZFJCj14lGQE= Received: from mail-qv1-f72.google.com (mail-qv1-f72.google.com [209.85.219.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-586-gIaLPR-lOfmpUXS57lEcTQ-1; Wed, 14 Jul 2021 18:25:02 -0400 X-MC-Unique: gIaLPR-lOfmpUXS57lEcTQ-1 Received: by mail-qv1-f72.google.com with SMTP id u8-20020a0562141c08b02902e82df307f0so2712846qvc.4 for ; Wed, 14 Jul 2021 15:25:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=pgOZ+9IjwVfKb5tKhAxRusG1z8GoeGAv34cmBph/B3s=; b=TOkvV1lwBgXvg9PLcvh6SAzS15So2devs3i0FxAuIX277WylVPJcMxGep7QM9lJtgP G6dqHdYxbIWHUaiLOP7ATrfv97/6SvHTkKFQw2UhPuRl4dWkv/QatGVfgUIEPbnbsFre PPJKIKZxmaVzRk48U3bIGaO5kwVACz7PCcuqqIWp0hzQbVnXOSLQ6cSgGtig1zRB72Iy mo8YechkCYji80K1gDGPIySf50KIEfLutQbMFtkLMy9g2WUXDfW5g5MfNSDKQcWzT+0A o65m7cy9fZTZHWEiEErSu3SrAQSr1XTHrLBjLpIGNfHMpTnzzF9gtPhA/iFV0bpQztFP KfKQ== X-Gm-Message-State: AOAM531fk9FFkVzfm3+e8RYJxF+iWCFbU2u8u5SwdpdRPK+W5870C9e2 zXVGKvadhZfZEbbl5l2/pENEv2h7TCPaSRxcJx1xn7PeJP9KPjumrQzo3u2itM/Ahtp8W33E6rz stHCDJqS6129rx/o7QW9hE7cE X-Received: by 2002:ac8:5ac3:: with SMTP id d3mr318883qtd.257.1626301502381; Wed, 14 Jul 2021 15:25:02 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwmUP5TjPEpwzMNS3GOKkC/oUMalgKy2Zc3e2y7pAB8MiTJNFhofDrLUpO66BNt/9fBL+Yu3A== X-Received: by 2002:ac8:5ac3:: with SMTP id d3mr318869qtd.257.1626301502188; Wed, 14 Jul 2021 15:25:02 -0700 (PDT) Received: from localhost.localdomain (bras-base-toroon474qw-grc-65-184-144-111-238.dsl.bell.ca. [184.144.111.238]) by smtp.gmail.com with ESMTPSA id o126sm1606702qka.74.2021.07.14.15.25.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Jul 2021 15:25:01 -0700 (PDT) From: Peter Xu To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Andrew Morton , Mike Kravetz , Axel Rasmussen , Miaohe Lin , "Kirill A . Shutemov" , Hugh Dickins , Jason Gunthorpe , Alistair Popple , Matthew Wilcox , peterx@redhat.com, Jerome Glisse , Andrea Arcangeli , Mike Rapoport , Nadav Amit , David Hildenbrand Subject: [PATCH v4 17/26] hugetlb/userfaultfd: Hook page faults for uffd write protection Date: Wed, 14 Jul 2021 18:24:58 -0400 Message-Id: <20210714222458.48942-1-peterx@redhat.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210714222117.47648-1-peterx@redhat.com> References: <20210714222117.47648-1-peterx@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hook up hugetlbfs_fault() with the capability to handle userfaultfd-wp faults. We do this slightly earlier than hugetlb_cow() so that we can avoid taking some extra locks that we definitely don't need. Reviewed-by: Mike Kravetz Signed-off-by: Peter Xu --- mm/hugetlb.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 924553aa8f78..8559b8bb7fa5 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5059,6 +5059,25 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) goto out_ptl; + /* Handle userfault-wp first, before trying to lock more pages */ + if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(ptep)) && + (flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { + struct vm_fault vmf = { + .vma = vma, + .address = haddr, + .flags = flags, + }; + + spin_unlock(ptl); + if (pagecache_page) { + unlock_page(pagecache_page); + put_page(pagecache_page); + } + mutex_unlock(&hugetlb_fault_mutex_table[hash]); + i_mmap_unlock_read(mapping); + return handle_userfault(&vmf, VM_UFFD_WP); + } + /* * hugetlb_cow() requires page locks of pte_page(entry) and * pagecache_page, so here we need take the former one -- 2.31.1