From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162917AbdD0P4i (ORCPT ); Thu, 27 Apr 2017 11:56:38 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:55375 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1032196AbdD0PxW (ORCPT ); Thu, 27 Apr 2017 11:53:22 -0400 From: Laurent Dufour To: paulmck@linux.vnet.ibm.com, peterz@infradead.org, akpm@linux-foundation.org, kirill@shutemov.name, ak@linux.intel.com, mhocko@kernel.org, dave@stgolabs.net, jack@suse.cz Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, haren@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com, npiggin@gmail.com, bsingharora@gmail.com Subject: [RFC v3 10/17] mm/spf: don't set fault entry's fields if locking failed Date: Thu, 27 Apr 2017 17:52:49 +0200 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1493308376-23851-1-git-send-email-ldufour@linux.vnet.ibm.com> References: <1493308376-23851-1-git-send-email-ldufour@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17042715-0040-0000-0000-0000039703FE X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17042715-0041-0000-0000-00001FE4962E Message-Id: <1493308376-23851-11-git-send-email-ldufour@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-04-27_14:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1704270259 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In the case pte_map_lock failed to lock the pte or if the VMA is no more valid, the fault entry's fields should not be set so that caller won't try to unlock it. Signed-off-by: Laurent Dufour --- mm/memory.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index f8afd52f0d34..3b28de5838c7 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2135,6 +2135,8 @@ static bool pte_spinlock(struct vm_fault *vmf) static bool pte_map_lock(struct vm_fault *vmf) { bool ret = false; + pte_t *pte; + spinlock_t *ptl; if (!(vmf->flags & FAULT_FLAG_SPECULATIVE)) { vmf->pte = pte_offset_map_lock(vmf->vma->vm_mm, vmf->pmd, @@ -2159,18 +2161,20 @@ static bool pte_map_lock(struct vm_fault *vmf) * to invalidate TLB but this CPU has irq disabled. * Since we are in a speculative patch, accept it could fail */ - vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd); - vmf->pte = pte_offset_map(vmf->pmd, vmf->address); - if (unlikely(!spin_trylock(vmf->ptl))) { - pte_unmap(vmf->pte); + ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd); + pte = pte_offset_map(vmf->pmd, vmf->address); + if (unlikely(!spin_trylock(ptl))) { + pte_unmap(pte); goto out; } if (vma_is_dead(vmf->vma, vmf->sequence)) { - pte_unmap_unlock(vmf->pte, vmf->ptl); + pte_unmap_unlock(pte, ptl); goto out; } + vmf->pte = pte; + vmf->ptl = ptl; ret = true; out: local_irq_enable(); -- 2.7.4