Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751897AbdFIOWD (ORCPT ); Fri, 9 Jun 2017 10:22:03 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:58552 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751884AbdFIOWA (ORCPT ); Fri, 9 Jun 2017 10:22:00 -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 18/20] x86/mm: Update the handle_speculative_fault's path Date: Fri, 9 Jun 2017 16:21:07 +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: 17060914-0040-0000-0000-000003C652E8 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17060914-0041-0000-0000-0000205E6D51 Message-Id: <1497018069-17790-19-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: 1504 Lines: 55 If handle_speculative_fault failed due to a VM ERROR, we try again the slow path to allow the signal to be delivered. Signed-off-by: Laurent Dufour --- arch/x86/mm/fault.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 0c0b45dfda76..02c0b884ca18 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1369,10 +1369,14 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code, fault = handle_speculative_fault(mm, address, flags & ~FAULT_FLAG_ALLOW_RETRY); - if (fault & VM_FAULT_RETRY) - goto retry; - - goto done; + /* + * We also check against VM_FAULT_ERROR because we have to + * raise a signal by calling later mm_fault_error() which + * requires the vma pointer to be set. So in that case, + * we fall through the normal path. + */ + if (!(fault & VM_FAULT_RETRY || fault & VM_FAULT_ERROR)) + goto done; } /* @@ -1478,20 +1482,13 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code, return; } - if (unlikely(fault & VM_FAULT_RETRY)) { - if (fatal_signal_pending(current)) - return; - - goto done; - } - up_read(&mm->mmap_sem); -done: if (unlikely(fault & VM_FAULT_ERROR)) { mm_fault_error(regs, error_code, address, vma, fault); return; } +done: /* * Major/minor page fault accounting. If any of the events * returned VM_FAULT_MAJOR, we account it as a major fault. -- 2.7.4