From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261647AbVFFTtd (ORCPT ); Mon, 6 Jun 2005 15:49:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261645AbVFFTta (ORCPT ); Mon, 6 Jun 2005 15:49:30 -0400 Received: from bay-bridge.veritas.com ([143.127.3.10]:20379 "EHLO MTVMIME03.enterprise.veritas.com") by vger.kernel.org with ESMTP id S261639AbVFFTrl (ORCPT ); Mon, 6 Jun 2005 15:47:41 -0400 Date: Mon, 6 Jun 2005 20:48:27 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@goblin.wat.veritas.com To: Andrew Morton cc: Andi Kleen , linux-kernel@vger.kernel.org Subject: [PATCH 1/2] mbind: fix verify_pages pte_page Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-OriginalArrivalTime: 06 Jun 2005 19:47:26.0636 (UTC) FILETIME=[90E166C0:01C56AD0] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Strict mbind's check that pages already mapped are on right node has been using pte_page without checking if pfn_valid, and without page_table_lock to prevent spurious failures when try_to_unmap_one intervenes between the pte_present and the pte_page. Signed-off-by: Hugh Dickins --- mm/mempolicy.c | 19 ++++++++++++++----- 1 files changed, 14 insertions(+), 5 deletions(-) --- 2.6.12-rc6/mm/mempolicy.c 2005-05-25 18:09:21.000000000 +0100 +++ linux/mm/mempolicy.c 2005-06-04 20:41:55.000000000 +0100 @@ -242,6 +242,9 @@ static int verify_pages(struct mm_struct *mm, unsigned long addr, unsigned long end, unsigned long *nodes) { + int err = 0; + + spin_lock(&mm->page_table_lock); while (addr < end) { struct page *p; pte_t *pte; @@ -268,17 +271,23 @@ verify_pages(struct mm_struct *mm, } p = NULL; pte = pte_offset_map(pmd, addr); - if (pte_present(*pte)) - p = pte_page(*pte); + if (pte_present(*pte)) { + unsigned long pfn = pte_pfn(*pte); + if (pfn_valid(pfn)) + p = pfn_to_page(pfn); + } pte_unmap(pte); if (p) { unsigned nid = page_to_nid(p); - if (!test_bit(nid, nodes)) - return -EIO; + if (!test_bit(nid, nodes)) { + err = -EIO; + break; + } } addr += PAGE_SIZE; } - return 0; + spin_unlock(&mm->page_table_lock); + return err; } /* Step 1: check the range */