From patchwork Thu Jan 28 00:09:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 372348 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED 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 2255DC433DB for ; Thu, 28 Jan 2021 00:11:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4D6D64DCE for ; Thu, 28 Jan 2021 00:11:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231645AbhA1ALW (ORCPT ); Wed, 27 Jan 2021 19:11:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:50892 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229835AbhA1AKc (ORCPT ); Wed, 27 Jan 2021 19:10:32 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id AF05164DD1; Thu, 28 Jan 2021 00:09:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1611792568; bh=meprjUpGiIVBheb707rmwX6RwWZvg57o5VvC2n4HDsk=; h=Date:From:To:Subject:From; b=pAHMDIQWJs4RMHGI0v3zCbPf0bTPThIpu7LAdSKfcRTiznKEcNldhW7/sOzbohdzF DFqOKsbZDPuRtOpTnDKTtoHhQHQBEEjr9QgFQ+HOSsdH8BOyuh4aA5Bxj3Xt01GskV 7DlZQUnUvBfF1t9PDUJ4mm6vlWzdn76yHeBrK0rk= Date: Wed, 27 Jan 2021 16:09:27 -0800 From: akpm@linux-foundation.org To: hannes@cmpxchg.org, linmiaohe@huawei.com, louhongxiang@huawei.com, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, shakeelb@google.com, stable@vger.kernel.org, vbabka@suse.cz, walken@google.com Subject: + mm-rmap-fix-potential-pte_unmap-on-an-not-mapped-pte.patch added to -mm tree Message-ID: <20210128000927.MhVdMWp-o%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch titled Subject: mm/rmap: fix potential pte_unmap on an not mapped pte has been added to the -mm tree. Its filename is mm-rmap-fix-potential-pte_unmap-on-an-not-mapped-pte.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-rmap-fix-potential-pte_unmap-on-an-not-mapped-pte.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-rmap-fix-potential-pte_unmap-on-an-not-mapped-pte.patch 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 and is updated there every 3-4 working days ------------------------------------------------------ From: Miaohe Lin Subject: mm/rmap: fix potential pte_unmap on an not mapped pte For PMD-mapped page (usually THP), pvmw->pte is NULL. For PTE-mapped THP, pvmw->pte is mapped. But for HugeTLB pages, pvmw->pte is not mapped and set to the relevant page table entry. So in page_vma_mapped_walk_done(), we may do pte_unmap() for HugeTLB pte which is not mapped. Fix this by checking pvmw->page against PageHuge before trying to do pte_unmap(). Link: https://lkml.kernel.org/r/20210127093349.39081-1-linmiaohe@huawei.com Fixes: ace71a19cec5 ("mm: introduce page_vma_mapped_walk()") Signed-off-by: Hongxiang Lou Signed-off-by: Miaohe Lin Cc: Mike Kravetz Cc: Shakeel Butt Cc: Johannes Weiner Cc: Vlastimil Babka Cc: Michel Lespinasse Cc: Signed-off-by: Andrew Morton --- include/linux/rmap.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/include/linux/rmap.h~mm-rmap-fix-potential-pte_unmap-on-an-not-mapped-pte +++ a/include/linux/rmap.h @@ -213,7 +213,8 @@ struct page_vma_mapped_walk { static inline void page_vma_mapped_walk_done(struct page_vma_mapped_walk *pvmw) { - if (pvmw->pte) + /* HugeTLB pte is set to the relevant page table entry without pte_mapped. */ + if (pvmw->pte && !PageHuge(pvmw->page)) pte_unmap(pvmw->pte); if (pvmw->ptl) spin_unlock(pvmw->ptl);