Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751909AbdFIOWI (ORCPT ); Fri, 9 Jun 2017 10:22:08 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:58864 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751884AbdFIOWF (ORCPT ); Fri, 9 Jun 2017 10:22:05 -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, Matthew Wilcox 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 v4 20/20] mm/spf: Clear FAULT_FLAG_KILLABLE in the speculative path Date: Fri, 9 Jun 2017 16:21:09 +0200 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1497018069-17790-1-git-send-email-ldufour@linux.vnet.ibm.com> References: <1497018069-17790-1-git-send-email-ldufour@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17060914-0016-0000-0000-000004B95431 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17060914-0017-0000-0000-000027E980FC Message-Id: <1497018069-17790-21-git-send-email-ldufour@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-06-09_07:,, 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-1706090251 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2547 Lines: 75 The flag FAULT_FLAG_KILLABLE should be unset to not allow the mmap_sem to released in __lock_page_or_retry(). In this patch the unsetting of the flag FAULT_FLAG_ALLOW_RETRY is also moved into handle_speculative_fault() since this has to be done for all architectures. Signed-off-by: Laurent Dufour --- arch/powerpc/mm/fault.c | 3 +-- arch/x86/mm/fault.c | 3 +-- mm/memory.c | 6 +++++- 3 files changed, 7 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 6dd6a50f412f..4b6d0ed517ca 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -304,8 +304,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, if (is_write) flags |= FAULT_FLAG_WRITE; - fault = handle_speculative_fault(mm, address, - flags & ~FAULT_FLAG_ALLOW_RETRY); + fault = handle_speculative_fault(mm, address, flags); if (!(fault & VM_FAULT_RETRY || fault & VM_FAULT_ERROR)) goto done; diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 02c0b884ca18..c62a7ea5e27b 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1366,8 +1366,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code, flags |= FAULT_FLAG_INSTRUCTION; if (error_code & PF_USER) { - fault = handle_speculative_fault(mm, address, - flags & ~FAULT_FLAG_ALLOW_RETRY); + fault = handle_speculative_fault(mm, address, flags); /* * We also check against VM_FAULT_ERROR because we have to diff --git a/mm/memory.c b/mm/memory.c index 5b158549789b..35a311b0d314 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3945,7 +3945,6 @@ int handle_speculative_fault(struct mm_struct *mm, unsigned long address, { struct vm_fault vmf = { .address = address, - .flags = flags | FAULT_FLAG_SPECULATIVE, }; pgd_t *pgd; p4d_t *p4d; @@ -3954,6 +3953,10 @@ int handle_speculative_fault(struct mm_struct *mm, unsigned long address, int dead, seq, idx, ret = VM_FAULT_RETRY; struct vm_area_struct *vma; + /* Clear flags that may lead to release the mmap_sem to retry */ + flags &= ~(FAULT_FLAG_ALLOW_RETRY|FAULT_FLAG_KILLABLE); + flags |= FAULT_FLAG_SPECULATIVE; + idx = srcu_read_lock(&vma_srcu); vma = find_vma_srcu(mm, address); if (!vma) @@ -4040,6 +4043,7 @@ int handle_speculative_fault(struct mm_struct *mm, unsigned long address, vmf.pgoff = linear_page_index(vma, address); vmf.gfp_mask = __get_fault_gfp_mask(vma); vmf.sequence = seq; + vmf.flags = flags; local_irq_enable(); -- 2.7.4