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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 A498CC10F00 for ; Mon, 25 Feb 2019 20:48:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 716762087C for ; Mon, 25 Feb 2019 20:48:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727569AbfBYUsb (ORCPT ); Mon, 25 Feb 2019 15:48:31 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:38230 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727230AbfBYUsb (ORCPT ); Mon, 25 Feb 2019 15:48:31 -0500 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1PKiLhC099902 for ; Mon, 25 Feb 2019 15:48:29 -0500 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2qvnuvngbs-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 25 Feb 2019 15:48:29 -0500 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 25 Feb 2019 20:48:27 -0000 Received: from b06cxnps4075.portsmouth.uk.ibm.com (9.149.109.197) by e06smtp03.uk.ibm.com (192.168.101.133) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 25 Feb 2019 20:48:22 -0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1PKmLPL30670850 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 25 Feb 2019 20:48:21 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 13A2C11C064; Mon, 25 Feb 2019 20:48:21 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 743B411C04C; Mon, 25 Feb 2019 20:48:18 +0000 (GMT) Received: from rapoport-lnx (unknown [9.148.204.243]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Mon, 25 Feb 2019 20:48:18 +0000 (GMT) Date: Mon, 25 Feb 2019 22:48:15 +0200 From: Mike Rapoport To: Peter Xu Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, David Hildenbrand , Hugh Dickins , Maya Gokhale , Jerome Glisse , Pavel Emelyanov , Johannes Weiner , Martin Cracauer , Shaohua Li , Marty McFadden , Andrea Arcangeli , Mike Kravetz , Denis Plotnikov , Mike Rapoport , Mel Gorman , "Kirill A . Shutemov" , "Dr . David Alan Gilbert" Subject: Re: [PATCH v2 19/26] userfaultfd: introduce helper vma_find_uffd References: <20190212025632.28946-1-peterx@redhat.com> <20190212025632.28946-20-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190212025632.28946-20-peterx@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-TM-AS-GCONF: 00 x-cbid: 19022520-0012-0000-0000-000002FA0E9C X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19022520-0013-0000-0000-00002131B02E Message-Id: <20190225204815.GB10454@rapoport-lnx> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-25_11:,, 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=956 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1902250149 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 12, 2019 at 10:56:25AM +0800, Peter Xu wrote: > We've have multiple (and more coming) places that would like to find a > userfault enabled VMA from a mm struct that covers a specific memory > range. This patch introduce the helper for it, meanwhile apply it to > the code. > > Suggested-by: Mike Rapoport > Signed-off-by: Peter Xu Reviewed-by: Mike Rapoport > --- > mm/userfaultfd.c | 54 +++++++++++++++++++++++++++--------------------- > 1 file changed, 30 insertions(+), 24 deletions(-) > > diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c > index 80bcd642911d..fefa81c301b7 100644 > --- a/mm/userfaultfd.c > +++ b/mm/userfaultfd.c > @@ -20,6 +20,34 @@ > #include > #include "internal.h" > > +/* > + * Find a valid userfault enabled VMA region that covers the whole > + * address range, or NULL on failure. Must be called with mmap_sem > + * held. > + */ > +static struct vm_area_struct *vma_find_uffd(struct mm_struct *mm, > + unsigned long start, > + unsigned long len) > +{ > + struct vm_area_struct *vma = find_vma(mm, start); > + > + if (!vma) > + return NULL; > + > + /* > + * Check the vma is registered in uffd, this is required to > + * enforce the VM_MAYWRITE check done at uffd registration > + * time. > + */ > + if (!vma->vm_userfaultfd_ctx.ctx) > + return NULL; > + > + if (start < vma->vm_start || start + len > vma->vm_end) > + return NULL; > + > + return vma; > +} > + > static int mcopy_atomic_pte(struct mm_struct *dst_mm, > pmd_t *dst_pmd, > struct vm_area_struct *dst_vma, > @@ -228,20 +256,9 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, > */ > if (!dst_vma) { > err = -ENOENT; > - dst_vma = find_vma(dst_mm, dst_start); > + dst_vma = vma_find_uffd(dst_mm, dst_start, len); > if (!dst_vma || !is_vm_hugetlb_page(dst_vma)) > goto out_unlock; > - /* > - * Check the vma is registered in uffd, this is > - * required to enforce the VM_MAYWRITE check done at > - * uffd registration time. > - */ > - if (!dst_vma->vm_userfaultfd_ctx.ctx) > - goto out_unlock; > - > - if (dst_start < dst_vma->vm_start || > - dst_start + len > dst_vma->vm_end) > - goto out_unlock; > > err = -EINVAL; > if (vma_hpagesize != vma_kernel_pagesize(dst_vma)) > @@ -488,20 +505,9 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm, > * both valid and fully within a single existing vma. > */ > err = -ENOENT; > - dst_vma = find_vma(dst_mm, dst_start); > + dst_vma = vma_find_uffd(dst_mm, dst_start, len); > if (!dst_vma) > goto out_unlock; > - /* > - * Check the vma is registered in uffd, this is required to > - * enforce the VM_MAYWRITE check done at uffd registration > - * time. > - */ > - if (!dst_vma->vm_userfaultfd_ctx.ctx) > - goto out_unlock; > - > - if (dst_start < dst_vma->vm_start || > - dst_start + len > dst_vma->vm_end) > - goto out_unlock; > > err = -EINVAL; > /* > -- > 2.17.1 > -- Sincerely yours, Mike.