From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [alternative-merged] mm-add-pte_present-check-on-existing-hugetlb_entry-callbacks.patch removed from -mm tree Date: Mon, 09 Jun 2014 11:59:02 -0700 Message-ID: <539603f6.0HgU/572TKrp3N9W%akpm@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]:53472 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750992AbaFIS7E (ORCPT ); Mon, 9 Jun 2014 14:59:04 -0400 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: mm-commits@vger.kernel.org, stable@vger.kernel.org, sasha.levin@oracle.com, riel@redhat.com, n-horiguchi@ah.jp.nec.com Subject: [alternative-merged] mm-add-pte_present-check-on-existing-hugetlb_entry-callbacks.patch removed from -mm tree To: n-horiguchi@ah.jp.nec.com,riel@redhat.com,sasha.levin@oracle.com,stable@vger.kernel.org,mm-commits@vger.kernel.org From: akpm@linux-foundation.org Date: Mon, 09 Jun 2014 11:59:02 -0700 The patch titled Subject: mm: add !pte_present() check on existing hugetlb_entry callbacks has been removed from the -mm tree. Its filename was mm-add-pte_present-check-on-existing-hugetlb_entry-callbacks.patch This patch was dropped because an alternative patch was merged ------------------------------------------------------ From: Naoya Horiguchi Subject: mm: add !pte_present() check on existing hugetlb_entry callbacks Page table walker doesn't check non-present hugetlb entry in common path, so hugetlb_entry() callbacks must check it. The reason for this behavior is that some callers want to handle it in its own way. However, some callers don't check it now, which causes unpredictable result, for example when we have a race between migrating hugepage and reading /proc/pid/numa_maps. This patch fixes it by adding !pte_present checks on buggy callbacks. This bug exists for years and got visible by introducing hugepage migration. ChangeLog v2: - fix if condition (check !pte_present() instead of pte_present()) Reported-by: Sasha Levin Signed-off-by: Naoya Horiguchi Cc: Rik van Riel Cc: [3.12+] Signed-off-by: Andrew Morton --- fs/proc/task_mmu.c | 3 +++ mm/mempolicy.c | 6 +++++- 2 files changed, 8 insertions(+), 1 deletion(-) diff -puN fs/proc/task_mmu.c~mm-add-pte_present-check-on-existing-hugetlb_entry-callbacks fs/proc/task_mmu.c --- a/fs/proc/task_mmu.c~mm-add-pte_present-check-on-existing-hugetlb_entry-callbacks +++ a/fs/proc/task_mmu.c @@ -1300,6 +1300,9 @@ static int gather_hugetlb_stats(pte_t *p if (pte_none(*pte)) return 0; + if (!pte_present(*pte)) + return 0; + page = pte_page(*pte); if (!page) return 0; diff -puN mm/mempolicy.c~mm-add-pte_present-check-on-existing-hugetlb_entry-callbacks mm/mempolicy.c --- a/mm/mempolicy.c~mm-add-pte_present-check-on-existing-hugetlb_entry-callbacks +++ a/mm/mempolicy.c @@ -524,8 +524,12 @@ static int queue_pages_hugetlb(pte_t *pt unsigned long flags = qp->flags; int nid; struct page *page; + pte_t entry; - page = pte_page(huge_ptep_get(pte)); + entry = huge_ptep_get(pte); + if (!pte_present(entry)) + return 0; + page = pte_page(entry); nid = page_to_nid(page); if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT)) return 0; _ Patches currently in -mm which might be from n-horiguchi@ah.jp.nec.com are origin.patch mm-hugetlbfs-fix-rmapping-for-anonymous-hugepages-with-page_pgoff.patch mm-hugetlbfs-fix-rmapping-for-anonymous-hugepages-with-page_pgoff-v2.patch mm-hugetlbfs-fix-rmapping-for-anonymous-hugepages-with-page_pgoff-v3.patch mm-hugetlbfs-fix-rmapping-for-anonymous-hugepages-with-page_pgoff-v3-fix.patch pagewalk-update-page-table-walker-core.patch pagewalk-update-page-table-walker-core-fix-end-address-calculation-in-walk_page_range.patch pagewalk-update-page-table-walker-core-fix-end-address-calculation-in-walk_page_range-fix.patch pagewalk-update-page-table-walker-core-fix.patch pagewalk-add-walk_page_vma.patch smaps-redefine-callback-functions-for-page-table-walker.patch clear_refs-redefine-callback-functions-for-page-table-walker.patch pagemap-redefine-callback-functions-for-page-table-walker.patch pagemap-redefine-callback-functions-for-page-table-walker-fix.patch numa_maps-redefine-callback-functions-for-page-table-walker.patch memcg-redefine-callback-functions-for-page-table-walker.patch arch-powerpc-mm-subpage-protc-use-walk_page_vma-instead-of-walk_page_range.patch pagewalk-remove-argument-hmask-from-hugetlb_entry.patch pagewalk-remove-argument-hmask-from-hugetlb_entry-fix.patch pagewalk-remove-argument-hmask-from-hugetlb_entry-fix-fix.patch mempolicy-apply-page-table-walker-on-queue_pages_range.patch mm-pagewalkc-move-pte-null-check.patch mm-prom-pid-clear_refs-avoid-split_huge_page.patch mm-introduce-do_shared_fault-and-drop-do_fault-fix-fix.patch do_shared_fault-check-that-mmap_sem-is-held.patch linux-next.patch