From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23607C10F03 for ; Tue, 23 Apr 2019 15:48:43 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A173D2175B for ; Tue, 23 Apr 2019 15:48:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A173D2175B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 44pSXn0s9TzDqMM for ; Wed, 24 Apr 2019 01:48:41 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=ldufour@linux.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 44pSTv1Y1ZzDqN1 for ; Wed, 24 Apr 2019 01:46:11 +1000 (AEST) Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x3NFeflU024024 for ; Tue, 23 Apr 2019 11:46:08 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2s240rnbqn-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 23 Apr 2019 11:46:08 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 23 Apr 2019 16:45:56 +0100 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x3NFjsxQ46137354 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 23 Apr 2019 15:45:54 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 591F042041; Tue, 23 Apr 2019 15:45:54 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 033D842049; Tue, 23 Apr 2019 15:45:52 +0000 (GMT) Received: from [9.145.7.116] (unknown [9.145.7.116]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 23 Apr 2019 15:45:51 +0000 (GMT) Subject: Re: [PATCH v12 05/31] mm: prepare for FAULT_FLAG_SPECULATIVE To: Jerome Glisse References: <20190416134522.17540-1-ldufour@linux.ibm.com> <20190416134522.17540-6-ldufour@linux.ibm.com> <20190418220415.GE11645@redhat.com> From: Laurent Dufour Date: Tue, 23 Apr 2019 17:45:51 +0200 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190418220415.GE11645@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19042315-0020-0000-0000-00000332DF37 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19042315-0021-0000-0000-0000218540CC Message-Id: <8b102fee-e1bc-28e4-2187-994e39fb6734@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-04-23_05:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904230106 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jack@suse.cz, sergey.senozhatsky.work@gmail.com, peterz@infradead.org, Will Deacon , mhocko@kernel.org, linux-mm@kvack.org, paulus@samba.org, Punit Agrawal , hpa@zytor.com, Michel Lespinasse , Alexei Starovoitov , Andrea Arcangeli , ak@linux.intel.com, Minchan Kim , aneesh.kumar@linux.ibm.com, x86@kernel.org, Matthew Wilcox , Daniel Jordan , Ingo Molnar , David Rientjes , paulmck@linux.vnet.ibm.com, Haiyan Song , npiggin@gmail.com, sj38.park@gmail.com, dave@stgolabs.net, kirill@shutemov.name, Thomas Gleixner , zhong jiang , Ganesh Mahendran , Yang Shi , Mike Rapoport , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky , vinayak menon , akpm@linux-foundation.org, Tim Chen , haren@linux.vnet.ibm.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Le 19/04/2019 à 00:04, Jerome Glisse a écrit : > On Tue, Apr 16, 2019 at 03:44:56PM +0200, Laurent Dufour wrote: >> From: Peter Zijlstra >> >> When speculating faults (without holding mmap_sem) we need to validate >> that the vma against which we loaded pages is still valid when we're >> ready to install the new PTE. >> >> Therefore, replace the pte_offset_map_lock() calls that (re)take the >> PTL with pte_map_lock() which can fail in case we find the VMA changed >> since we started the fault. >> >> Signed-off-by: Peter Zijlstra (Intel) >> >> [Port to 4.12 kernel] >> [Remove the comment about the fault_env structure which has been >> implemented as the vm_fault structure in the kernel] >> [move pte_map_lock()'s definition upper in the file] >> [move the define of FAULT_FLAG_SPECULATIVE later in the series] >> [review error path in do_swap_page(), do_anonymous_page() and >> wp_page_copy()] >> Signed-off-by: Laurent Dufour > > Reviewed-by: Jérôme Glisse > >> --- >> mm/memory.c | 87 +++++++++++++++++++++++++++++++++++------------------ >> 1 file changed, 58 insertions(+), 29 deletions(-) >> >> diff --git a/mm/memory.c b/mm/memory.c >> index c6ddadd9d2b7..fc3698d13cb5 100644 >> --- a/mm/memory.c >> +++ b/mm/memory.c >> @@ -2073,6 +2073,13 @@ int apply_to_page_range(struct mm_struct *mm, unsigned long addr, >> } >> EXPORT_SYMBOL_GPL(apply_to_page_range); >> >> +static inline bool pte_map_lock(struct vm_fault *vmf) > > I am not fan of the name maybe pte_offset_map_lock_if_valid() ? But > that just a taste thing. So feel free to ignore this comment. I agree with you that adding _if_valid or something equivalent to highlight the conditional of this function would be a good idea. I'll think further about that name but yours looks good ;) >> +{ >> + vmf->pte = pte_offset_map_lock(vmf->vma->vm_mm, vmf->pmd, >> + vmf->address, &vmf->ptl); >> + return true; >> +} >> + >> /* >> * handle_pte_fault chooses page fault handler according to an entry which was >> * read non-atomically. Before making any commitment, on those architectures >