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,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 EFBCAC433DF for ; Tue, 16 Jun 2020 07:56:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C61F1206F1 for ; Tue, 16 Jun 2020 07:56:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="HW8gH2+T" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726912AbgFPH4J (ORCPT ); Tue, 16 Jun 2020 03:56:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725896AbgFPHz5 (ORCPT ); Tue, 16 Jun 2020 03:55:57 -0400 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB7D8C05BD43 for ; Tue, 16 Jun 2020 00:55:57 -0700 (PDT) Received: by mail-pl1-x642.google.com with SMTP id x11so2623478plo.7 for ; Tue, 16 Jun 2020 00:55:57 -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=7Pc3zQ9D2av6U7xF9LkytuVQ3TEKU9mvAt7OV64zjjY=; b=HW8gH2+TWNb0LHKZx/L2PoIBSnyiXdbLTjOzJ/095pH2++lNTMOONJ7xnnd0H+jHXW cy2ds/KJlPcq6GvcObZ0FRsBjmMtjKWL04vJrlL98/z3To2opDDDxNgkBGN8RuF7Ae3x 26fr4H4QJtPjynRAQ+ouigUzMUv/iRlDT0tVGf/ctsZen6y3c52pZY+T9a7+kTgc7hfX +JWpN6PEiFPBEQX8/EqL6YsmcotVfmmhSi+4UuWoXiZEhIsClFPnNzka2k7W8rVdpxFy p/t6p2eVOdaj9vQ12Q81vUnfC+XghwjgAFfIukI5h4ap265404FgcNAAVN7Y1VA0acZ9 uP9g== 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=7Pc3zQ9D2av6U7xF9LkytuVQ3TEKU9mvAt7OV64zjjY=; b=uEMZxtJBcYUW9En2yAhTRlij65QkwJMXn+sJOYxe+0IW5qONbYJOjSWYitTWr2AaeI 6vJGRGMTnorm3mfVYDXYNiuUox8WsD6pb34VUiHp4dPDFff6sLPLr3k/bda1oRXhQ9ec JKy8iZ9hwlDsPciDQXNVHt4TrPo3pLlGUMdtIn/IiiT9jV6wcuem4NlTp6RI6ZuIBC3S DhfvCj3RMvQTrI0Fib0UF/ntF+OAgQ09+csydBTBZdlLjFamNSAHAOB3xyOUb1VgJU6n laZxumsgV2+VrE4BpPPzYrSDhOa5ZqKScGyXfkRdbMH9OoPEQ8l8oBN3jUDjRJSH2W3L wGGQ== X-Gm-Message-State: AOAM53361prmP1BKGGzZbhZXBGC28iySFXJRKG2/jaszKoP8jHQwu5bq KnxPAkBdJkBOnA6vrNmyQ+U= X-Google-Smtp-Source: ABdhPJysK/fjxfmRiTrNZmw9EgjGa6tFHoxvuUSFZZaxSjSNA9SxfwRSCAcSao3vO+Osm947ZTQLzw== X-Received: by 2002:a17:90b:3448:: with SMTP id lj8mr1567308pjb.163.1592294157009; Tue, 16 Jun 2020 00:55:57 -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.164.2020.06.16.00.55.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Jun 2020 00:55:56 -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 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace Date: Tue, 16 Jun 2020 00:55:41 -0700 Message-Id: <20200616075545.312684-3-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 The VVAR page layout depends on whether a task belongs to the root or non-root time namespace. Whenever a task changes its namespace, the VVAR page tables are cleared and then they will be re-faulted with a corresponding layout. Reviewed-by: Vincenzo Frascino Reviewed-by: Dmitry Safonov Signed-off-by: Andrei Vagin --- arch/arm64/kernel/vdso.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index b0aec4e8c9b4..df4bb736d28a 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -125,6 +125,38 @@ static int __vdso_init(enum vdso_abi abi) return 0; } +#ifdef CONFIG_TIME_NS +/* + * The vvar page layout depends on whether a task belongs to the root or + * non-root time namespace. Whenever a task changes its namespace, the VVAR + * page tables are cleared and then they will re-faulted with a + * corresponding layout. + * See also the comment near timens_setup_vdso_data() for details. + */ +int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) +{ + struct mm_struct *mm = task->mm; + struct vm_area_struct *vma; + + if (mmap_write_lock_killable(mm)) + return -EINTR; + + for (vma = mm->mmap; vma; vma = vma->vm_next) { + unsigned long size = vma->vm_end - vma->vm_start; + + if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA64].dm)) + zap_page_range(vma, vma->vm_start, size); +#ifdef CONFIG_COMPAT_VDSO + if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA32].dm)) + zap_page_range(vma, vma->vm_start, size); +#endif + } + + mmap_write_unlock(mm); + return 0; +} +#endif + static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, struct vm_area_struct *vma, struct vm_fault *vmf) { -- 2.24.1