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 53783C4332F for ; Tue, 29 Nov 2022 21:23:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237041AbiK2VXI (ORCPT ); Tue, 29 Nov 2022 16:23:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237051AbiK2VXH (ORCPT ); Tue, 29 Nov 2022 16:23:07 -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 2BC79120BC for ; Tue, 29 Nov 2022 13:23:06 -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 D2A09B8191E for ; Tue, 29 Nov 2022 21:23:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79D07C433D7; Tue, 29 Nov 2022 21:23:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1669756983; bh=ss2MFv93+xuey2cqRjFBcPnOdXbTegoNBBs5VERaqWs=; h=Date:To:From:Subject:From; b=N5v3uvty2Zbos74dQJKG9dlppj0MoCcMd80eT+e7eXAQ26qwqwQOr/a/XAbndLQHs hd0He1o+BMr6pLmuY7fJlA+Hj0iCUya7RKni0yweDHklYzrXcrLRAUsRONZeS0sdZr 0XmQ9QfRgzNJsO4cbxBr/An+CLjCwXKlzbKZ7NP4= Date: Tue, 29 Nov 2022 13:23:02 -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, jannh@google.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: <20221129212303.79D07C433D7@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: Tue, 29 Nov 2022 14:35:22 -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/20221129193526.3588187-7-peterx@redhat.com Signed-off-by: Peter Xu Cc: Andrea Arcangeli Cc: James Houghton Cc: Jann Horn Cc: Miaohe Lin Cc: Mike Kravetz 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 @@ -6232,9 +6232,10 @@ 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); @@ -6257,6 +6258,8 @@ 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-migrate-fix-read-only-page-got-writable-when-recover-pte.patch mm-always-compile-in-pte-markers.patch mm-use-pte-markers-for-swap-errors.patch mm-uffd-sanity-check-write-bit-for-uffd-wp-protected-ptes.patch selftests-vm-use-memfd-for-hugepage-mmap-test.patch mm-thp-re-apply-mkdirty-for-small-pages-after-split.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-make-page_vma_mapped_walk-safe-to-pmd-unshare.patch mm-hugetlb-introduce-hugetlb_walk.patch