From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754795Ab1FOK3M (ORCPT ); Wed, 15 Jun 2011 06:29:12 -0400 Received: from mga01.intel.com ([192.55.52.88]:26367 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752173Ab1FOK3L (ORCPT ); Wed, 15 Jun 2011 06:29:11 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.65,369,1304319600"; d="scan'208";a="16468778" Date: Wed, 15 Jun 2011 18:29:09 +0800 From: Shaohua Li To: linux-kernel@vger.kernel.org Cc: a.p.zijlstra@chello.nl, akpm@linux-foundation.org, torvalds@linux-foundation.org Subject: [PATCH]mm: use correct address for pte_unmap_unlock in zap_pte_range Message-ID: <20110615102909.GA23759@sli10-conroe.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Boot an i386 kernel, I got: [ 3.766613] WARNING: at /workshop/kernel/git/my/linux/arch/x86/mm/highmem_32.c:81 __kunmap_atomic+0x6f/0x113() [ 3.766615] Hardware name: Studio XPS 8000 [ 3.766617] Modules linked in: [ 3.766619] Pid: 214, comm: blkid Not tainted 3.0.0-rc3+ #529 [ 3.766621] Call Trace: [ 3.766625] [] warn_slowpath_common+0x6a/0x7f [ 3.766628] [] ? __kunmap_atomic+0x6f/0x113 [ 3.766631] [] warn_slowpath_null+0x14/0x18 [ 3.766633] [] __kunmap_atomic+0x6f/0x113 [ 3.766637] [] zap_pte_range+0x291/0x2b4 [ 3.766641] [] ? get_parent_ip+0xb/0x31 [ 3.766644] [] unmap_page_range+0x12a/0x147 [ 3.766647] [] unmap_vmas+0xa6/0xe2 [ 3.766650] [] exit_mmap+0x78/0xd3 [ 3.766654] [] mmput+0x39/0x99 [ 3.766657] [] exit_mm+0x101/0x109 [ 3.766660] [] do_exit+0x1e6/0x312 [ 3.766664] [] ? fput+0x18/0x1a [ 3.766666] [] do_group_exit+0x67/0x8a [ 3.766669] [] sys_exit_group+0x18/0x1c [ 3.766673] [] syscall_call+0x7/0xb the zap_pte_range does: pte = pte_offset_map_lock(mm, pmd, addr, &ptl); do { ... if (force_flush) break; ... } while (pte++, addr += PAGE_SIZE, addr != end); pte_unmap_unlock(pte - 1, ptl); the pte_unmap_unlock(pte - 1) only works if pte++ does once. this is a regression introduced by d16dfc550f5326a4000f3(mm: mmu_gather rework) Signed-off-by: Shaohua Li diff --git a/mm/memory.c b/mm/memory.c index 6953d39..f624945 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1112,11 +1112,11 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, int force_flush = 0; int rss[NR_MM_COUNTERS]; spinlock_t *ptl; - pte_t *pte; + pte_t *pte, *orig_pte; again: init_rss_vec(rss); - pte = pte_offset_map_lock(mm, pmd, addr, &ptl); + orig_pte = pte = pte_offset_map_lock(mm, pmd, addr, &ptl); arch_enter_lazy_mmu_mode(); do { pte_t ptent = *pte; @@ -1196,7 +1196,7 @@ again: add_mm_rss_vec(mm, rss); arch_leave_lazy_mmu_mode(); - pte_unmap_unlock(pte - 1, ptl); + pte_unmap_unlock(orig_pte, ptl); /* * mmu_gather ran out of room to batch pages, we break out of