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_HELO_NONE,SPF_PASS 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 194A3C04E87 for ; Mon, 20 May 2019 14:00:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EE7EA216B7 for ; Mon, 20 May 2019 14:00:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390919AbfETOA6 (ORCPT ); Mon, 20 May 2019 10:00:58 -0400 Received: from relay.sw.ru ([185.231.240.75]:39828 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387488AbfETOA5 (ORCPT ); Mon, 20 May 2019 10:00:57 -0400 Received: from [172.16.25.169] (helo=localhost.localdomain) by relay.sw.ru with esmtp (Exim 4.91) (envelope-from ) id 1hSiq4-00083Y-T0; Mon, 20 May 2019 17:00:29 +0300 Subject: [PATCH v2 5/7] mm: Introduce may_mmap_overlapped_region() helper From: Kirill Tkhai To: akpm@linux-foundation.org, dan.j.williams@intel.com, ktkhai@virtuozzo.com, mhocko@suse.com, keith.busch@intel.com, kirill.shutemov@linux.intel.com, alexander.h.duyck@linux.intel.com, ira.weiny@intel.com, andreyknvl@google.com, arunks@codeaurora.org, vbabka@suse.cz, cl@linux.com, riel@surriel.com, keescook@chromium.org, hannes@cmpxchg.org, npiggin@gmail.com, mathieu.desnoyers@efficios.com, shakeelb@google.com, guro@fb.com, aarcange@redhat.com, hughd@google.com, jglisse@redhat.com, mgorman@techsingularity.net, daniel.m.jordan@oracle.com, jannh@google.com, kilobyte@angband.pl, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Date: Mon, 20 May 2019 17:00:28 +0300 Message-ID: <155836082877.2441.3415778176783960096.stgit@localhost.localdomain> In-Reply-To: <155836064844.2441.10911127801797083064.stgit@localhost.localdomain> References: <155836064844.2441.10911127801797083064.stgit@localhost.localdomain> User-Agent: StGit/0.18 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Extract address space limit check for overlapped regions in a separate helper. v2: New Signed-off-by: Kirill Tkhai --- mm/mmap.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index e4ced5366643..260e47e917e6 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -583,6 +583,24 @@ static unsigned long count_vma_pages_range(struct mm_struct *mm, return nr_pages; } +/* + * Check against address space limit, whether we may expand mm + * with a new mapping. Currently mapped in the given range pages + * are not accounted in the limit. + */ +static bool may_mmap_overlapped_region(struct mm_struct *mm, + unsigned long vm_flags, unsigned long addr, unsigned long len) +{ + unsigned long nr_pages = len >> PAGE_SHIFT; + + if (!may_expand_vm(mm, vm_flags, nr_pages)) { + nr_pages -= count_vma_pages_range(mm, addr, addr + len); + if (!may_expand_vm(mm, vm_flags, nr_pages)) + return false; + } + return true; +} + void __vma_link_rb(struct mm_struct *mm, struct vm_area_struct *vma, struct rb_node **rb_link, struct rb_node *rb_parent) { @@ -1697,19 +1715,8 @@ unsigned long mmap_region(struct file *file, unsigned long addr, unsigned long charged = 0; /* Check against address space limit. */ - if (!may_expand_vm(mm, vm_flags, len >> PAGE_SHIFT)) { - unsigned long nr_pages; - - /* - * MAP_FIXED may remove pages of mappings that intersects with - * requested mapping. Account for the pages it would unmap. - */ - nr_pages = count_vma_pages_range(mm, addr, addr + len); - - if (!may_expand_vm(mm, vm_flags, - (len >> PAGE_SHIFT) - nr_pages)) - return -ENOMEM; - } + if (!may_mmap_overlapped_region(mm, vm_flags, addr, len)) + return -ENOMEM; /* Clear old maps */ while (find_vma_links(mm, addr, addr + len, &prev, &rb_link,