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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 93E57C433DF for ; Tue, 16 Jun 2020 07:56:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 720DF206D7 for ; Tue, 16 Jun 2020 07:56:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="jAeqV5Hh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727097AbgFPH4N (ORCPT ); Tue, 16 Jun 2020 03:56:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57980 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726753AbgFPH4C (ORCPT ); Tue, 16 Jun 2020 03:56:02 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F33BEC03E96A for ; Tue, 16 Jun 2020 00:56:01 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id n2so8009249pld.13 for ; Tue, 16 Jun 2020 00:56:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=hOFeWxf8l/srSoyQCmE9FGPNMQ1rcx/B9OKWA2Lr1tw=; b=jAeqV5HhZyYxsZ6KIgb17STQuBSzaVIfIkrSMQqXQaIfT/6CO29PLWJ41t8hnU2hZ6 RRlwvDlZ762LVTmAA/TnYh8g2Qz9mmqGZP9VJOMhmuHLLDqAwzOYo5y0M2+PYMo6+Fd4 hq9WbgYrztbgiLFbhTFTFgpUIaqSg8a1GhgBxFlTYgf/J/hHUnGx+2QqZlBY+J4ASr1T uRe9p0Tv+7dA8VR02tJ0/q8G1mKuUzhjB/I0us9MRRnC+D9ag7v8aB+Ylc6YSHSN19Ta 6Mf3lUNDx5PL5k3VXxcFQcxY6zZfR3xNSHcXXXk373+q6KyZGheOSNoVEnY5aUukplNE 7jWA== 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; bh=hOFeWxf8l/srSoyQCmE9FGPNMQ1rcx/B9OKWA2Lr1tw=; b=ew8N02aWadCHsmikyKzQghCd34W7AnBtn5ceEBjP7nlSbRjLDMJ6Wx9c3VOrHhzzxl i9nCuUq5JQAKBKoo6tbmUarli78dh7SlcQ3OZfGQFt6Dq6lek/7gxNsvD+WRxwGyhTVb p0WwPJ3B0yZkeDtl5qnxnYTAd8CSl1BAe4VdHFJlpFCbgQjcw+YMxdkJwkz3zEoV07lS op5GfuUlhbD0+zyndfOqHvVk9kbb3drE//fKJfsjd8CL/hUsbiQyLUPHa5c9CfKddHfu K9k2+jF2pkElHEKEYW6e37zVQsacBXb6QSTiPL2X/h/++/+bXaluB1097YYvgabDtpF4 oMcg== X-Gm-Message-State: AOAM533bqvHA7gWIIL4AttjcNFrkCfy0W3kCB75jjsj1jiaO38DiTQ9P +YH5JF6bV7DFqIlTwWSaUH0= X-Google-Smtp-Source: ABdhPJwOLCQsaIcJ1fFhE4hHC2egwIAnM+ejAPlFCeoi+Hbz5kYsARxJoXcjq2ZGwtsHiTohUaG5vw== X-Received: by 2002:a17:90b:3612:: with SMTP id ml18mr1671017pjb.153.1592294161414; Tue, 16 Jun 2020 00:56:01 -0700 (PDT) Received: from laptop.hsd1.wa.comcast.net ([2601:600:817f:a132:df3e:521d:99d5:710d]) by smtp.gmail.com with ESMTPSA id g6sm16168984pfb.164.2020.06.16.00.56.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Jun 2020 00:56:00 -0700 (PDT) From: Andrei Vagin To: linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon Cc: linux-kernel@vger.kernel.org, Vincenzo Frascino , Mark Rutland , Thomas Gleixner , Dmitry Safonov , Andrei Vagin Subject: [PATCH 5/6] arm64/vdso: Restrict splitting VVAR VMA Date: Tue, 16 Jun 2020 00:55:44 -0700 Message-Id: <20200616075545.312684-6-avagin@gmail.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20200616075545.312684-1-avagin@gmail.com> References: <20200616075545.312684-1-avagin@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Reviewed-by: Vincenzo Frascino Reviewed-by: Dmitry Safonov Signed-off-by: Andrei Vagin --- arch/arm64/kernel/vdso.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 21bdd0d74f40..68e021324113 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -226,6 +226,17 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, return vmf_insert_pfn(vma, vmf->address, pfn); } +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; + + if (new_size != VVAR_NR_PAGES * PAGE_SIZE) + return -EINVAL; + + return 0; +} + static int __setup_additional_pages(enum vdso_abi abi, struct mm_struct *mm, struct linux_binprm *bprm, @@ -308,6 +319,7 @@ static struct vm_special_mapping aarch32_vdso_maps[] = { [AA32_MAP_VVAR] = { .name = "[vvar]", .fault = vvar_fault, + .mremap = vvar_mremap, }, [AA32_MAP_VDSO] = { .name = "[vdso]", @@ -476,6 +488,7 @@ static struct vm_special_mapping aarch64_vdso_maps[] __ro_after_init = { [AA64_MAP_VVAR] = { .name = "[vvar]", .fault = vvar_fault, + .mremap = vvar_mremap, }, [AA64_MAP_VDSO] = { .name = "[vdso]", -- 2.24.1