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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 19412C31E50 for ; Sun, 16 Jun 2019 17:51:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD0382145D for ; Sun, 16 Jun 2019 17:51:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AHmV61cN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727412AbfFPRvQ (ORCPT ); Sun, 16 Jun 2019 13:51:16 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:40199 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726121AbfFPRvQ (ORCPT ); Sun, 16 Jun 2019 13:51:16 -0400 Received: by mail-wm1-f67.google.com with SMTP id v19so6740691wmj.5; Sun, 16 Jun 2019 10:51:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=eVSTx+XKpmuAqrrVQWr/mEKYA3TUsuFexdVGwSEmrwY=; b=AHmV61cNcCytwE+8j8CjiMsjNIVOGRJl0x50kDtiUSH87Snpxrx+DQjlsrur1SfIqB //5heBapOMqdR6mE4KXvRhYF04XeAIcX5AX82SqojNUX3HwDn9QeOvHwrW5mCR/7W1v9 lDgQz/gYNcGt9xJCn4Dn2pHQSSxDETDWn0BSbN/oEfVHIe/mrJGhS4ha3mXeF8YEEZnt 8gMDj2Kp4huPCmhP7XjqhLIOm6PvSiZp/HgszoEmiRBNWTWi4B0otGGNvscDA8bKD/c4 H7AUWqwpY8ZnIwojAii3StsNC/TP5Hy1JUcBtmvd1ARtIBSFoEHLkoraSPVMPciIaZus Y1Bw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=eVSTx+XKpmuAqrrVQWr/mEKYA3TUsuFexdVGwSEmrwY=; b=a6wK+b1JCiAmUgQVlIFTffnfv0l/3Fdoa4nCff/fyLvSq1kW3pE3160uAjZWd7JdxL FFNDsDvClJamIsS3NFO0ZdENZcRwEoeZxHDCAN32zXy1sxS1kDlIpp3qaOnkezKhLnsf DWkbEwYqdQkLSLQ/cs3NWumMRDWs7w3rCxS58/w/htVNyWI9E0CdaQazQnfr3Xfwv/oG qMzcSeLvUyfPVRUs//FjbNBj3SZh23zFd/pseuMoVGzBcqCE7WZgidtMWRDXkhxLt2sp Oywc1SL9Mb7nLVMFrXg3u2cqlS+ku80fRpKvpPSrRUs9PLzqrSk0kyIhZWjIh4A5SLW7 NSNw== X-Gm-Message-State: APjAAAWsXp9r92bSf5FildTGE9gNT5EwwPk4J7OTxgER2BGiNOdjAmiM /UqHlp8mObRWyeiSC/mImso= X-Google-Smtp-Source: APXvYqyBF8D/KuFgdlt61asAqKXISiqUTVlj4ZuVudEgQCX1Wvy8FZxNRT73ct+SazvV623KepnaPw== X-Received: by 2002:a1c:a807:: with SMTP id r7mr15250572wme.137.1560707474190; Sun, 16 Jun 2019 10:51:14 -0700 (PDT) Received: from [10.83.36.153] ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id s12sm8502671wmh.34.2019.06.16.10.51.12 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Sun, 16 Jun 2019 10:51:13 -0700 (PDT) Subject: Re: [PATCHv4 17/28] x86/vdso: Switch image on setns()/unshare()/clone() To: Thomas Gleixner , Dmitry Safonov Cc: linux-kernel@vger.kernel.org, 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 , Vincenzo Frascino , containers@lists.linux-foundation.org, criu@openvz.org, linux-api@vger.kernel.org, x86@kernel.org, Andrei Vagin References: <20190612192628.23797-1-dima@arista.com> <20190612192628.23797-18-dima@arista.com> From: Dmitry Safonov <0x7f454c46@gmail.com> Message-ID: Date: Sun, 16 Jun 2019 18:51:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/14/19 3:05 PM, Thomas Gleixner wrote: > On Wed, 12 Jun 2019, Dmitry Safonov wrote: >> >> +#ifdef CONFIG_TIME_NS >> +int vdso_join_timens(struct task_struct *task) >> +{ >> + 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, &vvar_mapping) || >> + vma_is_special_mapping(vma, &vdso_mapping)) >> + zap_page_range(vma, vma->vm_start, size); >> + } >> + >> + up_write(&mm->mmap_sem); >> + return 0; >> +} >> +#else /* CONFIG_TIME_NS */ >> +int vdso_join_timens(struct task_struct *task) >> +{ >> + return -ENXIO; >> +} > > Is that else path really required? The callsite is only compiled when > CONFIG_TIME_NS is enabled, right? Oh, yes - will drop this. Thanks, Dmitry