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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 39556C433DB for ; Mon, 29 Mar 2021 20:00:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0728D61990 for ; Mon, 29 Mar 2021 20:00:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231859AbhC2UAJ (ORCPT ); Mon, 29 Mar 2021 16:00:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231843AbhC2T7i (ORCPT ); Mon, 29 Mar 2021 15:59:38 -0400 Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 976F4C061756 for ; Mon, 29 Mar 2021 12:59:38 -0700 (PDT) Received: by mail-wm1-x32a.google.com with SMTP id g25so7236353wmh.0 for ; Mon, 29 Mar 2021 12:59:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=DKVpcQ+QpAoXvlyjRMhAGyT+Qqak2JfgZMLiBaSa29E=; b=YJPerRzl5+2JaKjv1Eb55P40KGWj7y6pfAam3YE3y8qhoEgUMMSGIdVfB6lepj10yJ D9JgvhbtBcvf8hfGDmq8z3Zv50QkNtIZMKlL7qEOsF0W8nlkcRq2Gz4nkYLLJ4Opvwcy GeQxTIHi0wGIiu/1stxEX8XdpEX32jglLEn2f5JXz86HT81AdRitSFe+KAw4HGbMqphK DL1N4R+sQxYSbcUqJpXZk6egdDmBADKsmQ/uJ+kUO2jfcDoV/VEjpB4e2hoPxcjqs62B jlYp0Woty23AO0P9Hdodnyz6GSb0jC1JbWGj8zhE4+rI4qkYA+zhreLGydVxQMXtRKcv NAiA== 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=DKVpcQ+QpAoXvlyjRMhAGyT+Qqak2JfgZMLiBaSa29E=; b=gEpcr8y4fkcs5g6iNxKmeZrGijAcpm5NyG6vdPJfBKNlGcmXIJHjtrUzNQnOA+Lm19 smxQx6n0aZMWc6C9PqlLz2DIl+O5del41YGye+Pgh2HkQO77wipOPAIcKJCR/H7tYN9Y z2MGTDDZwp4W/t33peu09e4iO9KJypsfwKn5oSLJ6iQSzCtUWfdWRBj6TJCZaHeTXnlK 8bIMG/GtsJ0LcajZNuuW7aIUECS8sXF/Fi8xF4Qf6ZkaMnyKSeI+ePPf5WVmKoFRgyN0 NsLd4RHRttB7YM9EqQsQFqBxPbvO58cczdL4Xrhyr9Sx10x2LJwmcG7EsZwwIFakyGSH pp7A== X-Gm-Message-State: AOAM531TDRABy9oNGe2tdiUBWLbfI9PoKvEZRMa3ZghRRmcLV2MtSM6n GswKI9fGPVbzSguf0vgMzEKvxA== X-Google-Smtp-Source: ABdhPJxY4+UJ5NboEvKsiKSfoZc8oEQ4w+NW1XvxfFLt4qF5Y5WCR92gIYO1xNtxtzr0yNW21PC1TQ== X-Received: by 2002:a7b:cbcd:: with SMTP id n13mr624923wmi.112.1617047977314; Mon, 29 Mar 2021 12:59:37 -0700 (PDT) Received: from ?IPv6:2a02:8084:e84:2480:228:f8ff:fe6f:83a8? ([2a02:8084:e84:2480:228:f8ff:fe6f:83a8]) by smtp.gmail.com with ESMTPSA id l6sm32426474wrn.3.2021.03.29.12.59.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 29 Mar 2021 12:59:36 -0700 (PDT) Subject: Re: [PATCH] powerpc/vdso: Separate vvar vma from vdso To: Laurent Dufour , linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Christophe Leroy , Andrei Vagin , Andy Lutomirski , Benjamin Herrenschmidt , Michael Ellerman , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, stable@vger.kernel.org References: <20210326191720.138155-1-dima@arista.com> From: Dmitry Safonov Message-ID: <50b7a78a-76e6-7d28-5324-a3ada9c43019@arista.com> Date: Mon, 29 Mar 2021 20:59:35 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/29/21 4:14 PM, Laurent Dufour wrote: > Le 26/03/2021 à 20:17, Dmitry Safonov a écrit : >> Since commit 511157ab641e ("powerpc/vdso: Move vdso datapage up front") >> VVAR page is in front of the VDSO area. In result it breaks CRIU >> (Checkpoint Restore In Userspace) [1], where CRIU expects that "[vdso]" >> from /proc/../maps points at ELF/vdso image, rather than at VVAR data >> page. >> Laurent made a patch to keep CRIU working (by reading aux vector). >> But I think it still makes sence to separate two mappings into different >> VMAs. It will also make ppc64 less "special" for userspace and as >> a side-bonus will make VVAR page un-writable by debugger (which >> previously >> would COW page and can be unexpected). >> >> I opportunistically Cc stable on it: I understand that usually such >> stuff isn't a stable material, but that will allow us in CRIU have >> one workaround less that is needed just for one release (v5.11) on >> one platform (ppc64), which we otherwise have to maintain. >> I wouldn't go as far as to say that the commit 511157ab641e is ABI >> regression as no other userspace got broken, but I'd really appreciate >> if it gets backported to v5.11 after v5.12 is released, so as not >> to complicate already non-simple CRIU-vdso code. Thanks! >> >> Cc: Andrei Vagin >> Cc: Andy Lutomirski >> Cc: Benjamin Herrenschmidt >> Cc: Christophe Leroy >> Cc: Laurent Dufour >> Cc: Michael Ellerman >> Cc: Paul Mackerras >> Cc: linuxppc-dev@lists.ozlabs.org >> Cc: stable@vger.kernel.org # v5.11 >> [1]: https://github.com/checkpoint-restore/criu/issues/1417 >> Signed-off-by: Dmitry Safonov >> Tested-by: Christophe Leroy > > I run the CRIU's test suite and except the usual suspects, all the tests > passed. > > Tested-by: Laurent Dufour Thank you, Laurent! -- Dmitry 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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 2F8EAC433E0 for ; Mon, 29 Mar 2021 20:00:21 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A456261606 for ; Mon, 29 Mar 2021 20:00:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A456261606 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=arista.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4F8NjH1gKbz30MT for ; Tue, 30 Mar 2021 07:00:19 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=arista.com header.i=@arista.com header.a=rsa-sha256 header.s=google header.b=YJPerRzl; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=arista.com (client-ip=2a00:1450:4864:20::333; helo=mail-wm1-x333.google.com; envelope-from=dima@arista.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=arista.com header.i=@arista.com header.a=rsa-sha256 header.s=google header.b=YJPerRzl; dkim-atps=neutral Received: from mail-wm1-x333.google.com (mail-wm1-x333.google.com [IPv6:2a00:1450:4864:20::333]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4F8Nhf4vSFz2yR1 for ; Tue, 30 Mar 2021 06:59:45 +1100 (AEDT) Received: by mail-wm1-x333.google.com with SMTP id d191so7202346wmd.2 for ; Mon, 29 Mar 2021 12:59:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=DKVpcQ+QpAoXvlyjRMhAGyT+Qqak2JfgZMLiBaSa29E=; b=YJPerRzl5+2JaKjv1Eb55P40KGWj7y6pfAam3YE3y8qhoEgUMMSGIdVfB6lepj10yJ D9JgvhbtBcvf8hfGDmq8z3Zv50QkNtIZMKlL7qEOsF0W8nlkcRq2Gz4nkYLLJ4Opvwcy GeQxTIHi0wGIiu/1stxEX8XdpEX32jglLEn2f5JXz86HT81AdRitSFe+KAw4HGbMqphK DL1N4R+sQxYSbcUqJpXZk6egdDmBADKsmQ/uJ+kUO2jfcDoV/VEjpB4e2hoPxcjqs62B jlYp0Woty23AO0P9Hdodnyz6GSb0jC1JbWGj8zhE4+rI4qkYA+zhreLGydVxQMXtRKcv NAiA== 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=DKVpcQ+QpAoXvlyjRMhAGyT+Qqak2JfgZMLiBaSa29E=; b=KWP71K7KH9GmE1PWdtWjKVmPGZQsVdONaYnoGBasG/HHo+OafsPO/APpu3J6+R+6L+ fXUC+YKf3H343Oul+pwPyegM2OCUIA7LaJlMH8oJGz6KGchTxwjnlPfps0m+XW+w/t/m SvjMYmGc2LtfnFt3ix36ZCMeYZr6vkCrddkt+RbOd2XQco6nBQo6SN/8Socz+sQYTdf5 +dK5BFYM8ANsmMhRtBMAFMh9F5vuU/meEM6it9E8hxnqrjs2cBMrLE9ToLf4Q1QTtFjz F/I8tXkr6kuqgb9bTOB95qF1sRWAXVooF5TSmF0+DTA89PbY0kLl4l4Tvv1fgclDbLBk HSGw== X-Gm-Message-State: AOAM5316FlKNQP7wzOQiovlUBz5vfFds0MhHWMrog+ckCFsAbiKZM7Oa fLi2h/hnaNgCNqiR9hdhgljVZg== X-Google-Smtp-Source: ABdhPJxY4+UJ5NboEvKsiKSfoZc8oEQ4w+NW1XvxfFLt4qF5Y5WCR92gIYO1xNtxtzr0yNW21PC1TQ== X-Received: by 2002:a7b:cbcd:: with SMTP id n13mr624923wmi.112.1617047977314; Mon, 29 Mar 2021 12:59:37 -0700 (PDT) Received: from ?IPv6:2a02:8084:e84:2480:228:f8ff:fe6f:83a8? ([2a02:8084:e84:2480:228:f8ff:fe6f:83a8]) by smtp.gmail.com with ESMTPSA id l6sm32426474wrn.3.2021.03.29.12.59.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 29 Mar 2021 12:59:36 -0700 (PDT) Subject: Re: [PATCH] powerpc/vdso: Separate vvar vma from vdso To: Laurent Dufour , linux-kernel@vger.kernel.org References: <20210326191720.138155-1-dima@arista.com> From: Dmitry Safonov Message-ID: <50b7a78a-76e6-7d28-5324-a3ada9c43019@arista.com> Date: Mon, 29 Mar 2021 20:59:35 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Andrei Vagin , Paul Mackerras , stable@vger.kernel.org, Andy Lutomirski , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 3/29/21 4:14 PM, Laurent Dufour wrote: > Le 26/03/2021 à 20:17, Dmitry Safonov a écrit : >> Since commit 511157ab641e ("powerpc/vdso: Move vdso datapage up front") >> VVAR page is in front of the VDSO area. In result it breaks CRIU >> (Checkpoint Restore In Userspace) [1], where CRIU expects that "[vdso]" >> from /proc/../maps points at ELF/vdso image, rather than at VVAR data >> page. >> Laurent made a patch to keep CRIU working (by reading aux vector). >> But I think it still makes sence to separate two mappings into different >> VMAs. It will also make ppc64 less "special" for userspace and as >> a side-bonus will make VVAR page un-writable by debugger (which >> previously >> would COW page and can be unexpected). >> >> I opportunistically Cc stable on it: I understand that usually such >> stuff isn't a stable material, but that will allow us in CRIU have >> one workaround less that is needed just for one release (v5.11) on >> one platform (ppc64), which we otherwise have to maintain. >> I wouldn't go as far as to say that the commit 511157ab641e is ABI >> regression as no other userspace got broken, but I'd really appreciate >> if it gets backported to v5.11 after v5.12 is released, so as not >> to complicate already non-simple CRIU-vdso code. Thanks! >> >> Cc: Andrei Vagin >> Cc: Andy Lutomirski >> Cc: Benjamin Herrenschmidt >> Cc: Christophe Leroy >> Cc: Laurent Dufour >> Cc: Michael Ellerman >> Cc: Paul Mackerras >> Cc: linuxppc-dev@lists.ozlabs.org >> Cc: stable@vger.kernel.org # v5.11 >> [1]: https://github.com/checkpoint-restore/criu/issues/1417 >> Signed-off-by: Dmitry Safonov >> Tested-by: Christophe Leroy > > I run the CRIU's test suite and except the usual suspects, all the tests > passed. > > Tested-by: Laurent Dufour Thank you, Laurent! -- Dmitry