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,URIBL_BLOCKED, 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 3F2EEC43331 for ; Tue, 12 Nov 2019 01:28:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F27A21D7F for ; Tue, 12 Nov 2019 01:28:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b="bxKujLwp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727431AbfKLB2G (ORCPT ); Mon, 11 Nov 2019 20:28:06 -0500 Received: from mail-wr1-f66.google.com ([209.85.221.66]:45136 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727351AbfKLB17 (ORCPT ); Mon, 11 Nov 2019 20:27:59 -0500 Received: by mail-wr1-f66.google.com with SMTP id z10so11374960wrs.12 for ; Mon, 11 Nov 2019 17:27:58 -0800 (PST) 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=SPSw/UOdt7xB1QuYCMoUI4pcnZZHq7LOyRGakzDPhvI=; b=bxKujLwpSvnSBfvq+9GxFXZBk0fosEFIQu9lr4CCpHjCV/1cevth4hWeSvwGu3jXUg iMTnekQcGqyu8pgBV8mUR5Aoc7otsDk6EAlPtSc3HK7VqBocmppGL3L5GjAaFdpCOaT5 YmqAw/nwAkf0ITdD9Wrzy5yom9JD730T7okBxndsP3B1o2IxyS4ZZlTz32imsooh0TwN yzuq33yvbBT5hRRykeOZmVsdUMp08FvumwBSyoxL0PXiHm4U4m7uf9wF4TB4hdl0e/4z CZgt4KoRn7GTL1AZo2W/8wiRiZRurgZP1uJFhOqvE2V8CZEPNBXpk5sZhMGjrsX98Fkt NUfg== 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=SPSw/UOdt7xB1QuYCMoUI4pcnZZHq7LOyRGakzDPhvI=; b=PN/lTXPIKQyGD6UzArHS0n2JVzHbQBn2u+KwP/5ipHY0YxfeFX7NmMbhWN8TY4q9Sd J7Kz4wVUiWcb0/qnOAZt4MAJ1lTxPuZ/E8Rfs3ZMVvwDQIoKOnODYCGSjE5MIKFb1BWI r47OQ+TotYeBLsd3tjCeeb/8abVOtD84OorN2GB0hcItUA4L0OKqmvNeHI2pvXnLhtfC Uyw7vZ7/HkSMfYdD7PCo+bEHUohCOyd3seKQQIAABhkTUbjveDmVhLNC+SUp0Yg9Wi+u 8dcJ+OjdJNyTQ+K9fC517YDnNbLDGrjhEYowL8IlmDjwdypVd0vPfWbU+gLm4oNJ4MJz DEmA== X-Gm-Message-State: APjAAAXhBa9iS9GUF7GY2/rsRraOhz9FYTLSNbBZ9nmztq6NtW1dS6Mh prjqotg1lvum7jDSrI59kWDQVsy2zgI= X-Google-Smtp-Source: APXvYqxJ52RCdRtZXBGKvF7hBbK4CsqzC6J5l2nywtYZwC4mbKUuLfByBGGlt3KvYWcvwHacM8yMHQ== X-Received: by 2002:a5d:5687:: with SMTP id f7mr2689884wrv.384.1573522077199; Mon, 11 Nov 2019 17:27:57 -0800 (PST) Received: from Mindolluin.ire.aristanetworks.com ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id u187sm1508096wme.15.2019.11.11.17.27.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Nov 2019 17:27:56 -0800 (PST) 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: [PATCHv8 19/34] x86/vdso: Restrict splitting VVAR VMA Date: Tue, 12 Nov 2019 01:27:08 +0000 Message-Id: <20191112012724.250792-20-dima@arista.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112012724.250792-1-dima@arista.com> References: <20191112012724.250792-1-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, }; /* -- 2.24.0