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 87BC2C35247 for ; Tue, 4 Feb 2020 17:59:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D40621741 for ; Tue, 4 Feb 2020 17:59:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="f2D9vquN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727557AbgBDR7e (ORCPT ); Tue, 4 Feb 2020 12:59:34 -0500 Received: from mail-pl1-f195.google.com ([209.85.214.195]:32944 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727361AbgBDR70 (ORCPT ); Tue, 4 Feb 2020 12:59:26 -0500 Received: by mail-pl1-f195.google.com with SMTP id ay11so7583321plb.0 for ; Tue, 04 Feb 2020 09:59:25 -0800 (PST) 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=7Yq7DlP+MKcqgZ3wsjfCTguAnbXfIOKWROJvqxl0zoQ=; b=f2D9vquNX5DsXU5g1xuVZpuFt9sTH4kFwsIAWNMIjnxU4QKnljJhk9oBZx4jGkTBER L2lJn5kkTuXGKXMRxq1F7++Ge53ax+ujxh1P/CQHoT6Aa+x4zGIEGrGLIPiu3zV1MqqD IjnegYIZYOF9cHDeb5aYhnyZve7ybwBeT/ofK1QB2aM6Myt/7mATzhWcfhbwZm3rIOki By3TJYdZqvQBqPIxasrGkhNYd1py0kxsUijkqJ7xpQxmX8ygFycQ6L4uKslE7Jdc9pFV YQbTzpCfLKBG+UqTQqsBPCWELHqafw+dikqc9/SOsCJ9KcCXPR8uD9mRUrZxG41OinTK PT0Q== 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=7Yq7DlP+MKcqgZ3wsjfCTguAnbXfIOKWROJvqxl0zoQ=; b=gnYLqTIhQwWKxMa6eXJ31N0ROMaXH0GgD7vyLY3DWuR3fBj3fGgnAPI2IFJ3lpRiHp r3Gg+0KljoqQdiFux9A1dYWS0REh6PF2p25cwIA6fEzowcUm1XoyWlGtw40+w7bbROrC y1fHeo/M86tn2/UiEwi+QKJ1hMbImJk6fjoqJF2hITFfzLHdl/CYfv/siJU/Z4wYioGE Juygv4Zad9V0bYIayTDCl/urm4wrfKNPMWkI4/COUwN+cfXtwVe09HTyTnBUtE1n/Yy0 UHAYwkcevgmCgVnzeNxDQKD206vCctTtFErs5fjZxZKOZGLz/RcoASGExVs2tOeLa5iS MEpw== X-Gm-Message-State: APjAAAVRszgUAFw4+SHzGPwhqL7fTdRxA6hPQYkhuWeIJ44oNYjnuU4W 2yjGdbbl5OhYULY7xb/mBwc= X-Google-Smtp-Source: APXvYqzZ3hxUy2pgjYnm+E5KKwzAk92s+OrDRAm4xSLtLf0eFvS2+/aSnkqwr9PMcUcTGFMIy3Fd9A== X-Received: by 2002:a17:90a:1697:: with SMTP id o23mr363140pja.62.1580839165382; Tue, 04 Feb 2020 09:59:25 -0800 (PST) Received: from localhost.localdomain ([2620:0:1008:fd00:25a6:3140:768c:a64d]) by smtp.gmail.com with ESMTPSA id d73sm25414465pfd.109.2020.02.04.09.59.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Feb 2020 09:59:24 -0800 (PST) From: Andrei Vagin To: Vincenzo Frascino Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Andrei Vagin , Thomas Gleixner , Dmitry Safonov Subject: [PATCH 2/5] arm64/vdso: Zap vvar pages when switching to a time namespace Date: Tue, 4 Feb 2020 09:59:10 -0800 Message-Id: <20200204175913.74901-3-avagin@gmail.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20200204175913.74901-1-avagin@gmail.com> References: <20200204175913.74901-1-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. 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 c4b4758eaf0b..5ef808ddf08c 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -131,6 +131,38 @@ static int __vdso_init(enum arch_vdso_type arch_index) 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 (down_write_killable(&mm->mmap_sem)) + 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_lookup[ARM64_VDSO].dm)) + zap_page_range(vma, vma->vm_start, size); +#ifdef CONFIG_COMPAT_VDSO + if (vma_is_special_mapping(vma, vdso_lookup[ARM64_VDSO32].dm)) + zap_page_range(vma, vma->vm_start, size); +#endif + } + + up_write(&mm->mmap_sem); + 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