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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 504A8C433F5 for ; Thu, 10 Mar 2022 21:18:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343926AbiCJVTI (ORCPT ); Thu, 10 Mar 2022 16:19:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244230AbiCJVTF (ORCPT ); Thu, 10 Mar 2022 16:19:05 -0500 Received: from mail-wr1-x430.google.com (mail-wr1-x430.google.com [IPv6:2a00:1450:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0404220EC for ; Thu, 10 Mar 2022 13:18:02 -0800 (PST) Received: by mail-wr1-x430.google.com with SMTP id r10so9961103wrp.3 for ; Thu, 10 Mar 2022 13:18:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=google; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=GLYfYjKYhGeuO9cwBbNFdK5OLsNYW6r1/vF7iHoZpf8=; b=bnTSnEHsHQ9Ryu+/9on7487yeHcImgWtQ8wbY0FCN67k39bj93EVE5/lYcsfPbDuQs +zxxAnRthtpVWcSLOwl2xDYhs6VLwhE9kdIMBctK+b3etQfaMZ5FLOKLA49nMAO0N6Yy KYyOLTGeI1GHGJjX0f2tCJUFV5tZgDHnbazZFAoN9MzJclMaV8khV8jjVnMTcu8zFy1N YQhcSQYcvi1UT2Ne7Cy4q9SuY8bmoipv+yEWFHpJHCxnAlzk2stE+7up2jI7PeoBOgrD 93LsUeaRDXrzM29LCCo9Ex0r1V98kEAFC7kH1q8ikLsVdLLy65CJYypgpD/2J20y8jP0 7rGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=GLYfYjKYhGeuO9cwBbNFdK5OLsNYW6r1/vF7iHoZpf8=; b=7k35JraVeGxkaq4YbWrhwicxI42YpClPPPDQK8ttNyGzJs4OCWcVmUCLD56N3M8oew iZQOfg4gHXgSbiNhLyKDThnUW5gulqHvdO5GVHaZLM+1sSzHcJqp73oiW9BWlGDhc/+Q Q+EGkOKTDdjk9NDa+YDEvC2Mqoz/Soo6OZNWE+7Ryz3AC8+0U15p3FlfO5l7lcsMK0t6 ME5ikwGQkCCkqlnq/zuCVLY0+05HFshI808Zx4mZqX7Vi7JifvNHOoHBqImKnQqgJtZI /P/T4XlbNZrmoDIZ6jF6pVWYbbus6/U4IXqV8hKGB5jqR2Nahu2jRUPYESlyoDph+Z2w 6wig== X-Gm-Message-State: AOAM53296SjCy8QQgDOXDg6y8aTPRcKj5q3+mFmEZk+SwB/WzCUcKHIT eJkKGMvRDl18HKWrx00FtfgGtw== X-Google-Smtp-Source: ABdhPJytgTpS5Y9Kb/rhchWgE2PDTEK5dnB9LNEZLwUEbOA/kf5h9VMdXCqqQ17C1f75Z1sj5Q1M7w== X-Received: by 2002:a5d:47a1:0:b0:1f1:d733:ea8d with SMTP id 1-20020a5d47a1000000b001f1d733ea8dmr4849381wrb.557.1646947081442; Thu, 10 Mar 2022 13:18:01 -0800 (PST) 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 x2-20020adff0c2000000b001f1fa284a32sm5100744wro.115.2022.03.10.13.17.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 10 Mar 2022 13:18:01 -0800 (PST) Message-ID: <6b2513db-7c31-8da4-38ec-0b9898c6589c@arista.com> Date: Thu, 10 Mar 2022 21:17:58 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.2 Subject: Re: [PATCH v3 00/23] Add generic vdso_base tracking Content-Language: en-US To: Christophe Leroy , linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Alexander Viro , Andrew Morton , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Guo Ren , "H. Peter Anvin" , Ingo Molnar , Oleg Nesterov , Russell King , Thomas Bogendoerfer , Thomas Gleixner , Vincenzo Frascino , Will Deacon , x86@kernel.org References: <20210611180242.711399-1-dima@arista.com> <8bba9ed8-ae1f-7c98-fde5-808927935447@csgroup.eu> From: Dmitry Safonov In-Reply-To: <8bba9ed8-ae1f-7c98-fde5-808927935447@csgroup.eu> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christophe, On 3/9/22 15:41, Christophe Leroy wrote: > Hi Dmitry, > > I'm wondering the status of this series. Yeah, I plan to work on v4 addressing the reviews. WFH has quite affected my work on side-projects and I've laid aside for a while this patch set that touches every architecture and is besides a bit challenging to upstream. > Wondering what to do while reviewing pending powerpc patches and > especially > https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20201103171336.98883-1-ldufour@linux.ibm.com/ Please, go ahead with that - I'll base v4 patches on the top of that. Thanks for pinging me about this. > Christophe > > Le 11/06/2021 à 20:02, Dmitry Safonov a écrit : >> v3 Changes: >> - Migrated arch/powerpc to vdso_base >> - Added x86/selftest for unmapped vdso & no landing on fast syscall >> - Review comments from Andy & Christophe (thanks!) >> - Amended s/born process/execed process/ everywhere I noticed >> - Build robot warning on cast from __user pointer >> >> I've tested it on x86, I would appreciate any help with >> Tested-by on arm/arm64/mips/powerpc/s390/... platforms. >> >> One thing I've noticed while cooking this and haven't found a clean >> way to solve is zero-terminated .pages[] array in vdso mappings, which >> is not always zero-terminated but works by the reason of >> VM_DONTEXPAND on mappings. >> >> v2 Changes: >> - Rename user_landing to vdso_base as it tracks vDSO VMA start address, >>    rather than the explicit address to land (Andy) >> - Reword and don't use "new-execed" and "new-born" task (Andy) >> - Fix failures reported by build robot >> >> Started from discussion [1], where was noted that currently a couple of >> architectures support mremap() for vdso/sigpage, but not munmap(). >> If an application maps something on the ex-place of vdso/sigpage, >> later after processing signal it will land there (good luck!) >> >> Patches set is based on linux-next (next-20201123) and it depends on >> changes in x86/cleanups (those reclaim TIF_IA32/TIF_X32) and also >> on my changes in akpm (fixing several mremap() issues). >> >> Logically, the patches set divides on: >> - patch       1: a cleanup for patches in x86/cleanups >> - patches  2-13: cleanups for arch_setup_additional_pages() >> - patches 13-14: x86 signal changes for unmapped vdso >> - patches 15-22: provide generic vdso_base in mm_struct >> - patch      23: selftest for unmapped vDSO & fast syscalls >> >> In the end, besides cleanups, it's now more predictable what happens for >> applications with unmapped vdso on architectures those support .mremap() >> for vdso/sigpage. >> >> I'm aware of only one user that unmaps vdso - Valgrind [2]. >> (there possibly are more, but this one is "special", it unmaps vdso, but >>   not vvar, which confuses CRIU [Checkpoint Restore In Userspace], that's >>   why I'm aware of it) >> > > I'm wondering the status of this series. > > Wondering what to do while reviewing pending powerpc patches and > especially > https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20201103171336.98883-1-ldufour@linux.ibm.com/ > > > Christophe > Thanks, Dmitry