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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 25F9FC4360C for ; Fri, 11 Oct 2019 01:25:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EFB8E214E0 for ; Fri, 11 Oct 2019 01:25:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b="KRF0RDQW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728420AbfJKBZX (ORCPT ); Thu, 10 Oct 2019 21:25:23 -0400 Received: from mail-wm1-f66.google.com ([209.85.128.66]:37887 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728169AbfJKBYN (ORCPT ); Thu, 10 Oct 2019 21:24:13 -0400 Received: by mail-wm1-f66.google.com with SMTP id f22so8514495wmc.2 for ; Thu, 10 Oct 2019 18:24:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=googlenew; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=NYMfxuYafYA15ogjer2QokPPquY/p6/+qp/AHoWSBKg=; b=KRF0RDQW8fNf4SrQJ/BJe77i7hG/VBLhOnS1pS7U5xdnRZ127l5a7U8pa8wF/27xTt V7m+VhiXUL8VvW3A89FP5ynREeyWGhn6DxVIO6OD7r22+3i7rtkUMNeGEvtZsldBXXQZ UURRZDKzaodNRm7GDlSliJ1oJIoBe3p1Yq3z+83N+182BdZuRNFNfx5xgFMFJPOeFeaM OrNmIPnWYZH/D9PAVEIfnPTBMAzqvsMs+8aim8fta2yioJMir3A7M2W1y+ZW/m3UZbps Vf2g8szA/LZ4BkRxUOqmsQjIQfImg806W2wltGdeO+O6xTsj6YysJ9TzRXfTT84bCnlU 9q7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=NYMfxuYafYA15ogjer2QokPPquY/p6/+qp/AHoWSBKg=; b=DMpmHLThV4RlIHy0f0Kl77R3iGMNBrOEMHa+R+QvBohn57S2/6Qt0x26P/A+YmBtIq oUnnk2cnJcGkzO2kNB80S/XAf8YLPCbuNxgs7++WLVMuZR4HvqPEXuFNVjFfa8ivREwS XTPrflAqN6miELY2tRGw4nZhbsC4HU5q6fkQ1lB7EhfDutnNtvy5dOEwSgPEWpwdJ7W2 YaGi2ppGfyhCt2kXuqwlGD83ckjEj+jpObhpt+8JCqEfR11Ww6czCkJnR8VUxM2RapfI nbbgLEnAhYdsx7XEijMfg7+80Uen6PNrA4XwfP0oHxE7vQ1+73M3tCR9YLwquxxPwzdG lbjQ== X-Gm-Message-State: APjAAAVvZVhoCtlPTqe1nH2s+H6wpAHYWJR8riHQJR0MeFGWRwRaKRxm F6PTwG8b+hS03rWETkNqcANdcr0lE28= X-Google-Smtp-Source: APXvYqzLSjse8Wf03RVf0lGrZ/pUjmmgECDppkbi+ynK/RnTDv4C5ECtxTzBn4dLKupFArlF53/QGw== X-Received: by 2002:a1c:f201:: with SMTP id s1mr895956wmc.59.1570757051151; Thu, 10 Oct 2019 18:24:11 -0700 (PDT) Received: from localhost.localdomain ([2a02:8084:ea2:c100:228:f8ff:fe6f:83a8]) by smtp.gmail.com with ESMTPSA id l13sm7699795wmj.25.2019.10.10.18.24.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Oct 2019 18:24:10 -0700 (PDT) From: Dmitry Safonov To: linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Dmitry Safonov , Adrian Reber , Andrei Vagin , Andy Lutomirski , Arnd Bergmann , Christian Brauner , Cyrill Gorcunov , "Eric W. Biederman" , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Jeff Dike , Oleg Nesterov , Pavel Emelyanov , Shuah Khan , Thomas Gleixner , Vincenzo Frascino , containers@lists.linux-foundation.org, criu@openvz.org, linux-api@vger.kernel.org, x86@kernel.org Subject: [PATCHv7 17/33] x86/vdso: Restrict splitting VVAR VMA Date: Fri, 11 Oct 2019 02:23:25 +0100 Message-Id: <20191011012341.846266-18-dima@arista.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191011012341.846266-1-dima@arista.com> References: <20191011012341.846266-1-dima@arista.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Forbid splitting VVAR resulting in stricter ABI and reducing amount of corner-cases to consider while working further on VDSO. As 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 --- 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 f5937742b290..000db8282cc8 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) +{ + unsigned long new_size = new_vma->vm_end - new_vma->vm_start; + const struct vdso_image *image = new_vma->vm_mm->context.vdso_image; + + 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, }; /* -- 2.23.0