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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 5C0BAC33CB6 for ; Tue, 14 Jan 2020 13:02:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 215332469E for ; Tue, 14 Jan 2020 13:02:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729028AbgANNCk (ORCPT ); Tue, 14 Jan 2020 08:02:40 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:43210 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728921AbgANNCe (ORCPT ); Tue, 14 Jan 2020 08:02:34 -0500 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1irLpt-0004ec-4X; Tue, 14 Jan 2020 14:02:21 +0100 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id E8E301C0813; Tue, 14 Jan 2020 14:02:16 +0100 (CET) Date: Tue, 14 Jan 2020 13:02:16 -0000 From: "tip-bot2 for Dmitry Safonov" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: timers/core] x86/vdso: Restrict splitting VVAR VMA Cc: Andrei Vagin , Dmitry Safonov , Thomas Gleixner , x86 , LKML In-Reply-To: <20191112012724.250792-20-dima@arista.com> References: <20191112012724.250792-20-dima@arista.com> MIME-Version: 1.0 Message-ID: <157900693679.396.3734935657870398991.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the timers/core branch of tip: Commit-ID: 6f74acfde20af1eb2178d0bd846bfd8f50b3be32 Gitweb: https://git.kernel.org/tip/6f74acfde20af1eb2178d0bd846bfd8f50b3be32 Author: Dmitry Safonov AuthorDate: Tue, 12 Nov 2019 01:27:08 Committer: Thomas Gleixner CommitterDate: Tue, 14 Jan 2020 12:20:56 +01:00 x86/vdso: Restrict splitting VVAR VMA Forbid splitting VVAR VMA resulting in a stricter ABI and reducing the amount of corner-cases to consider while working further on VDSO time namespace support. As the offset from timens to VVAR page is computed compile-time, the pages in VVAR should stay together and not being partically mremap()'ed. Co-developed-by: Andrei Vagin Signed-off-by: Andrei Vagin Signed-off-by: Dmitry Safonov Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20191112012724.250792-20-dima@arista.com --- arch/x86/entry/vdso/vma.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index f593774..76cbe54 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -84,6 +84,18 @@ static int vdso_mremap(const struct vm_special_mapping *sm, return 0; } +static int vvar_mremap(const struct vm_special_mapping *sm, + struct vm_area_struct *new_vma) +{ + const struct vdso_image *image = new_vma->vm_mm->context.vdso_image; + unsigned long new_size = new_vma->vm_end - new_vma->vm_start; + + if (new_size != -image->sym_vvar_start) + return -EINVAL; + + return 0; +} + static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, struct vm_area_struct *vma, struct vm_fault *vmf) { @@ -136,6 +148,7 @@ static const struct vm_special_mapping vdso_mapping = { static const struct vm_special_mapping vvar_mapping = { .name = "[vvar]", .fault = vvar_fault, + .mremap = vvar_mremap, }; /*