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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 14DD6C10F12 for ; Mon, 15 Apr 2019 19:11:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D3D45218DA for ; Mon, 15 Apr 2019 19:11:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555355503; bh=os3sHdUzInbdpZxlphxhiyFbwlwCjyFjrK3Nr0IaKOk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YDSUWOJRWWEM7aGU2XfZWwClDW17cEQyEuJSHI7RzSS7J5mYaxOnhUw4mRaPe40m6 qXtIP2nKRxBm5FfsppeHPm0jp8oSb6eC3vkG6QXknI38MEtqhUX3M2dJ6rBYnmPIGr Zeg3wpTbkAT8grJi0X4+pabUnaY/krCKSkNbkLKU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731283AbfDOTLm (ORCPT ); Mon, 15 Apr 2019 15:11:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:48694 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731268AbfDOTLj (ORCPT ); Mon, 15 Apr 2019 15:11:39 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 5DB6C218DA; Mon, 15 Apr 2019 19:11:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555355498; bh=os3sHdUzInbdpZxlphxhiyFbwlwCjyFjrK3Nr0IaKOk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nv7sILy4gMSrGuxcoZ0cNHa/zsRVhNPunYgfFFzWyGBB5xv7RML+F5WPJwEN0G4mK y3+UH5KmSirTUl3Qx0ZrnMjZeDB5LqHlCQ9Z4hAWoxjTurJgMJPXAdKGw31lG6Mu7e U/nWB5M84G3PAE9sy4+bGxldDoAblzatNs+ghnvA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Aneesh Kumar K.V" , Chandan Rajendra , Jan Kara , Dan Williams , Andrew Morton , Linus Torvalds Subject: [PATCH 5.0 058/117] mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd() Date: Mon, 15 Apr 2019 21:00:28 +0200 Message-Id: <20190415183747.881878682@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190415183744.887851196@linuxfoundation.org> References: <20190415183744.887851196@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Aneesh Kumar K.V commit c6f3c5ee40c10bb65725047a220570f718507001 upstream. With some architectures like ppc64, set_pmd_at() cannot cope with a situation where there is already some (different) valid entry present. Use pmdp_set_access_flags() instead to modify the pfn which is built to deal with modifying existing PMD entries. This is similar to commit cae85cb8add3 ("mm/memory.c: fix modifying of page protection by insert_pfn()") We also do similar update w.r.t insert_pfn_pud eventhough ppc64 don't support pud pfn entries now. Without this patch we also see the below message in kernel log "BUG: non-zero pgtables_bytes on freeing mm:" Link: http://lkml.kernel.org/r/20190402115125.18803-1-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V Reported-by: Chandan Rajendra Reviewed-by: Jan Kara Cc: Dan Williams Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/huge_memory.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -753,6 +753,21 @@ static void insert_pfn_pmd(struct vm_are spinlock_t *ptl; ptl = pmd_lock(mm, pmd); + if (!pmd_none(*pmd)) { + if (write) { + if (pmd_pfn(*pmd) != pfn_t_to_pfn(pfn)) { + WARN_ON_ONCE(!is_huge_zero_pmd(*pmd)); + goto out_unlock; + } + entry = pmd_mkyoung(*pmd); + entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); + if (pmdp_set_access_flags(vma, addr, pmd, entry, 1)) + update_mmu_cache_pmd(vma, addr, pmd); + } + + goto out_unlock; + } + entry = pmd_mkhuge(pfn_t_pmd(pfn, prot)); if (pfn_t_devmap(pfn)) entry = pmd_mkdevmap(entry); @@ -764,11 +779,16 @@ static void insert_pfn_pmd(struct vm_are if (pgtable) { pgtable_trans_huge_deposit(mm, pmd, pgtable); mm_inc_nr_ptes(mm); + pgtable = NULL; } set_pmd_at(mm, addr, pmd, entry); update_mmu_cache_pmd(vma, addr, pmd); + +out_unlock: spin_unlock(ptl); + if (pgtable) + pte_free(mm, pgtable); } vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, @@ -819,6 +839,20 @@ static void insert_pfn_pud(struct vm_are spinlock_t *ptl; ptl = pud_lock(mm, pud); + if (!pud_none(*pud)) { + if (write) { + if (pud_pfn(*pud) != pfn_t_to_pfn(pfn)) { + WARN_ON_ONCE(!is_huge_zero_pud(*pud)); + goto out_unlock; + } + entry = pud_mkyoung(*pud); + entry = maybe_pud_mkwrite(pud_mkdirty(entry), vma); + if (pudp_set_access_flags(vma, addr, pud, entry, 1)) + update_mmu_cache_pud(vma, addr, pud); + } + goto out_unlock; + } + entry = pud_mkhuge(pfn_t_pud(pfn, prot)); if (pfn_t_devmap(pfn)) entry = pud_mkdevmap(entry); @@ -828,6 +862,8 @@ static void insert_pfn_pud(struct vm_are } set_pud_at(mm, addr, pud, entry); update_mmu_cache_pud(vma, addr, pud); + +out_unlock: spin_unlock(ptl); }