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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96DA3C46467 for ; Fri, 16 Dec 2022 17:18:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231750AbiLPRSO (ORCPT ); Fri, 16 Dec 2022 12:18:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230089AbiLPRSD (ORCPT ); Fri, 16 Dec 2022 12:18:03 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69E19389FB for ; Fri, 16 Dec 2022 09:18:02 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 280C5B81DDA for ; Fri, 16 Dec 2022 17:18:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D8BEDC433EF; Fri, 16 Dec 2022 17:17:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1671211079; bh=aA9G/dKRFqc8JFfqIdtgjVrVSUZDXXc5u9b0e9VuW4o=; h=Date:To:From:Subject:From; b=L0CxIzzIubrh5RqrmV791ZK7O0aGtfShjDT5Vm7qotuF8W9LpbFW94AdElvDvy3sC JW8oPjoiYvewxpfZREqK489eukI9x55wm4NlH6O59t7sxs2vmAX2AhEcpyo3mZBRun qsO9jNFj1Pgv5rVsEj4frRO2nN3qxW9TeWxvccRw= Date: Fri, 16 Dec 2022 09:17:59 -0800 To: mm-commits@vger.kernel.org, songmuchun@bytedance.com, riel@surriel.com, nadav.amit@gmail.com, mike.kravetz@oracle.com, linmiaohe@huawei.com, jthoughton@google.com, jhubbard@nvidia.com, jannh@google.com, david@redhat.com, aarcange@redhat.com, peterx@redhat.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-hugetlb-make-hugetlb_follow_page_mask-safe-to-pmd-unshare.patch added to mm-unstable branch Message-Id: <20221216171759.D8BEDC433EF@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm/hugetlb: make hugetlb_follow_page_mask() safe to pmd unshare has been added to the -mm mm-unstable branch. Its filename is mm-hugetlb-make-hugetlb_follow_page_mask-safe-to-pmd-unshare.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-make-hugetlb_follow_page_mask-safe-to-pmd-unshare.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Peter Xu Subject: mm/hugetlb: make hugetlb_follow_page_mask() safe to pmd unshare Date: Fri, 16 Dec 2022 10:52:19 -0500 Since hugetlb_follow_page_mask() walks the pgtable, it needs the vma lock to make sure the pgtable page will not be freed concurrently. Link: https://lkml.kernel.org/r/20221216155219.2043714-1-peterx@redhat.com Signed-off-by: Peter Xu Acked-by: David Hildenbrand Reviewed-by: Mike Kravetz Reviewed-by: John Hubbard Cc: Andrea Arcangeli Cc: James Houghton Cc: Jann Horn Cc: Miaohe Lin Cc: Muchun Song Cc: Nadav Amit Cc: Rik van Riel Signed-off-by: Andrew Morton --- mm/hugetlb.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/mm/hugetlb.c~mm-hugetlb-make-hugetlb_follow_page_mask-safe-to-pmd-unshare +++ a/mm/hugetlb.c @@ -6375,9 +6375,10 @@ struct page *hugetlb_follow_page_mask(st if (WARN_ON_ONCE(flags & FOLL_PIN)) return NULL; + hugetlb_vma_lock_read(vma); pte = huge_pte_offset(mm, haddr, huge_page_size(h)); if (!pte) - return NULL; + goto out_unlock; ptl = huge_pte_lock(h, mm, pte); entry = huge_ptep_get(pte); @@ -6400,6 +6401,8 @@ struct page *hugetlb_follow_page_mask(st } out: spin_unlock(ptl); +out_unlock: + hugetlb_vma_unlock_read(vma); return page; } _ Patches currently in -mm which might be from peterx@redhat.com are mm-uffd-fix-pte-marker-when-fork-without-fork-event.patch mm-fix-a-few-rare-cases-of-using-swapin-error-pte-marker.patch mm-uffd-always-wr-protect-pte-in-ptepmd_mkuffd_wp.patch mm-hugetlb-let-vma_offset_start-to-return-start.patch mm-hugetlb-dont-wait-for-migration-entry-during-follow-page.patch mm-hugetlb-document-huge_pte_offset-usage.patch mm-hugetlb-move-swap-entry-handling-into-vma-lock-when-faulted.patch mm-hugetlb-make-userfaultfd_huge_must_wait-safe-to-pmd-unshare.patch mm-hugetlb-make-hugetlb_follow_page_mask-safe-to-pmd-unshare.patch mm-hugetlb-make-follow_hugetlb_page-safe-to-pmd-unshare.patch mm-hugetlb-make-walk_hugetlb_range-safe-to-pmd-unshare.patch mm-hugetlb-introduce-hugetlb_walk.patch