From patchwork Tue Apr 7 03:05:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11477249 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A4F6D14B4 for ; Tue, 7 Apr 2020 03:05:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7283F20801 for ; Tue, 7 Apr 2020 03:05:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="i+gI713V" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7283F20801 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 489738E002E; Mon, 6 Apr 2020 23:05:56 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 413098E0001; Mon, 6 Apr 2020 23:05:56 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3506C8E002E; Mon, 6 Apr 2020 23:05:56 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0167.hostedemail.com [216.40.44.167]) by kanga.kvack.org (Postfix) with ESMTP id 217648E0001 for ; Mon, 6 Apr 2020 23:05:56 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id D2A69A2B0 for ; Tue, 7 Apr 2020 03:05:55 +0000 (UTC) X-FDA: 76679569470.15.time02_6dec11983174e X-Spam-Summary: 2,0,0,a552a06cf97ffc39,d41d8cd98f00b204,akpm@linux-foundation.org,,RULES_HIT:41:355:379:800:960:967:973:988:989:1260:1263:1345:1359:1381:1431:1437:1534:1542:1711:1730:1747:1777:1792:2194:2199:2393:2525:2559:2563:2682:2685:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3353:3865:3867:3868:3871:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4250:4321:4605:5007:6119:6261:6653:6737:6738:7514:7576:8599:8957:9025:9545:10004:10913:11026:11473:11658:11914:12043:12048:12296:12297:12438:12517:12519:12555:12679:12783:12986:13846:14093:14181:14381:14721:14849:21080:21451:21627:21939:30054:30064,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-64.100.201.201 62.2.0.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:1,LUA_SUMMARY:none X-HE-Tag: time02_6dec11983174e X-Filterd-Recvd-Size: 4322 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Tue, 7 Apr 2020 03:05:55 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C9892217D8; Tue, 7 Apr 2020 03:05:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586228754; bh=HmiklbTPXPF9adNo3V1HQv15ZTvZBcz0SSjanPdrKnk=; h=Date:From:To:Subject:In-Reply-To:From; b=i+gI713VdxK/2eqCDd3klqsoGQpagmiANU9SVsVmwe3UnAiM7ndm4Dtrs1rYECWPC O/8C1M3bNniEKt8IdzWpYhKaOEIJFt7ZUzscEB/fH+I627fLRUzbzMUpgoSBdSsCE5 a8Yk1iUtGO8Bex9j0OsZpYuNkqxFN7kzZ0FGD0V0= Date: Mon, 06 Apr 2020 20:05:53 -0700 From: Andrew Morton To: aarcange@redhat.com, akpm@linux-foundation.org, bgeffon@google.com, bobbypowers@gmail.com, cracauer@cons.org, david@redhat.com, dgilbert@redhat.com, dplotnikov@virtuozzo.com, gokhale2@llnl.gov, hannes@cmpxchg.org, hughd@google.com, jglisse@redhat.com, kirill@shutemov.name, linux-mm@kvack.org, mcfadden8@llnl.gov, mgorman@suse.de, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, peterx@redhat.com, riel@redhat.com, rppt@linux.vnet.ibm.com, shli@fb.com, torvalds@linux-foundation.org, xemul@openvz.org Subject: [patch 040/166] userfaultfd: wp: drop _PAGE_UFFD_WP properly when fork Message-ID: <20200407030553.BrbbIQvwC%akpm@linux-foundation.org> In-Reply-To: <20200406200254.a69ebd9e08c4074e41ddebaf@linux-foundation.org> User-Agent: s-nail v14.8.16 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: From: Peter Xu Subject: userfaultfd: wp: drop _PAGE_UFFD_WP properly when fork UFFD_EVENT_FORK support for uffd-wp should be already there, except that we should clean the uffd-wp bit if uffd fork event is not enabled. Detect that to avoid _PAGE_UFFD_WP being set even if the VMA is not being tracked by VM_UFFD_WP. Do this for both small PTEs and huge PMDs. Link: http://lkml.kernel.org/r/20200220163112.11409-9-peterx@redhat.com Signed-off-by: Peter Xu Reviewed-by: Jerome Glisse Reviewed-by: Mike Rapoport Cc: Andrea Arcangeli Cc: Bobby Powers Cc: Brian Geffon Cc: David Hildenbrand Cc: Denis Plotnikov Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Johannes Weiner Cc: "Kirill A . Shutemov" Cc: Martin Cracauer Cc: Marty McFadden Cc: Maya Gokhale Cc: Mel Gorman Cc: Mike Kravetz Cc: Pavel Emelyanov Cc: Rik van Riel Cc: Shaohua Li Signed-off-by: Andrew Morton --- mm/huge_memory.c | 8 ++++++++ mm/memory.c | 8 ++++++++ 2 files changed, 16 insertions(+) --- a/mm/huge_memory.c~userfaultfd-wp-drop-_page_uffd_wp-properly-when-fork +++ a/mm/huge_memory.c @@ -1044,6 +1044,14 @@ int copy_huge_pmd(struct mm_struct *dst_ ret = -EAGAIN; pmd = *src_pmd; + /* + * Make sure the _PAGE_UFFD_WP bit is cleared if the new VMA + * does not have the VM_UFFD_WP, which means that the uffd + * fork event is not enabled. + */ + if (!(vma->vm_flags & VM_UFFD_WP)) + pmd = pmd_clear_uffd_wp(pmd); + #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION if (unlikely(is_swap_pmd(pmd))) { swp_entry_t entry = pmd_to_swp_entry(pmd); --- a/mm/memory.c~userfaultfd-wp-drop-_page_uffd_wp-properly-when-fork +++ a/mm/memory.c @@ -785,6 +785,14 @@ copy_one_pte(struct mm_struct *dst_mm, s pte = pte_mkclean(pte); pte = pte_mkold(pte); + /* + * Make sure the _PAGE_UFFD_WP bit is cleared if the new VMA + * does not have the VM_UFFD_WP, which means that the uffd + * fork event is not enabled. + */ + if (!(vm_flags & VM_UFFD_WP)) + pte = pte_clear_uffd_wp(pte); + page = vm_normal_page(vma, addr, pte); if (page) { get_page(page);