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=-2.1 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, USER_AGENT_SANE_1 autolearn=no 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 5A817C3A59D for ; Fri, 16 Aug 2019 20:21:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 312D62133F for ; Fri, 16 Aug 2019 20:21:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="CI0xUsIQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727650AbfHPUVF (ORCPT ); Fri, 16 Aug 2019 16:21:05 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:34269 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727608AbfHPUVE (ORCPT ); Fri, 16 Aug 2019 16:21:04 -0400 Received: by mail-wr1-f66.google.com with SMTP id s18so2676298wrn.1; Fri, 16 Aug 2019 13:21:02 -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=HSbCBY4QdI505ZahQQ32YYrjA5TNW/1raAfMSboMpfA=; b=CI0xUsIQ+H/XNaqKp3RkPVOR9R9uyWBLkicvYSW9uT1pLt+1y8VwcO2h+egsrsWBZY O8T7+5HI4yJmsIiLfJYgvEqsP1XzDNpe3Y8dRLYSdwGZd3X6HLP/7+mHExlNw7ySPV90 9JU4LptAPe9/Jdzln5g9MEO9XSlYR3XbrUN8dPul1MQBiT/Rz8ogzXfhNeXeO5E2/FHm uZa4H5l0XXrD16GsRhAQEgFuFwo89C/doTRFJ+jOOcYmk2iJ9T/3A9wOKJVHyUS3knBF LGI4yitDYHglnB5AbPdiQJXvmls4MPHAL4KQ/vj8o8KwI2CHjfxkCQg7dWszE4U5X+ex M/GA== 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=HSbCBY4QdI505ZahQQ32YYrjA5TNW/1raAfMSboMpfA=; b=Xeckq8QUHZcFG4XrSiGq0R1qOKb2rjdYMrIZUPLhTQigscSEj43iR1pLtRF/5G5e/F wAMMK+O7FZahAA9R1osYAmgJ+D4OaGMLvvCfpKcUWCKkiXuvpqC4IgKiac/p1l+n1TRu uuOm3boXR4at16q1X4LuMmLmYFkBLNIpxt4LIRKU4dUbs1AjxydUkyNMCM+UDeDR1q3T fJda10P1rFBgChjCbFkoK8KZ6cOtfuOOKJNbSS7/t9zgZ57rgqXGbWnlRfpPlFdqPDaP kWyDcBFg8E6v70VkskVGxdLmRN1EDPx8NsVlk/tTeDOX5gqiWzeS51ecDhn7UgPGi6kF XqrQ== X-Gm-Message-State: APjAAAWUo1MfTy5ASpgmwqCFrehYul02Ee+ZJBqftbMuwjn6PIZ0D2Qt /wdRsW4+v0wgWZKqGGQgVPo= X-Google-Smtp-Source: APXvYqwta2RmL2q4PYnVIins/WNeDrwRp2ETTjsH9PlTQpGfqqqFgzJUl7YEmvT7Dqsn0v7lynqb0g== X-Received: by 2002:adf:e887:: with SMTP id d7mr12690432wrm.282.1565986862226; Fri, 16 Aug 2019 13:21:02 -0700 (PDT) Received: from [10.83.36.153] ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id f23sm4247882wmj.37.2019.08.16.13.21.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 16 Aug 2019 13:21:01 -0700 (PDT) Subject: Re: [PATCHv6 22/36] x86/vdso: Add offsets page in vvar To: Thomas Gleixner , Dmitry Safonov Cc: linux-kernel@vger.kernel.org, Andrei Vagin , Adrian Reber , 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: <20190815163836.2927-1-dima@arista.com> <20190815163836.2927-23-dima@arista.com> From: Dmitry Safonov <0x7f454c46@gmail.com> Message-ID: <1a97f7a5-9380-fdb1-6b00-070950347355@gmail.com> Date: Fri, 16 Aug 2019 21:20:59 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 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 Hi Thomas, On 8/15/19 8:21 PM, Thomas Gleixner wrote: > On Thu, 15 Aug 2019, Dmitry Safonov wrote: >> --- >> arch/Kconfig | 5 +++ >> arch/x86/Kconfig | 1 + >> arch/x86/entry/vdso/vdso-layout.lds.S | 9 ++++- >> arch/x86/entry/vdso/vdso2c.c | 3 ++ >> arch/x86/entry/vdso/vma.c | 12 +++++++ >> arch/x86/include/asm/vdso.h | 1 + >> init/Kconfig | 1 + >> lib/vdso/gettimeofday.c | 47 +++++++++++++++++++++++++++ > > This needs to be split into the generic lib/vdso part and then x86 making > use of it. Ok >> +#ifdef CONFIG_TIME_NS > > This should be COMPILE_WITH_TIME_NS and not CONFIG_TIME_NS > >> +extern u8 timens_page >> + __attribute__((visibility("hidden"))); >> + >> +notrace static __always_inline void clk_to_ns(clockid_t clk, struct __kernel_timespec *ts) > > This needs notrace because? Heh, well it's alive from the time it was in arch/x86. I believe, functions there had it since commit 23adec554a76 ("x86: add notrace annotations to vsyscall"). Probably, lib/vdso is compiled without mcount in the Makefile somewhere. Will drop. [..] >> + /* >> + * The kernel allows to set a negative offset only if the current clock >> + * value in a namespace is positive, so the result tv_sec can't be >> + * negative here. >> + */ >> + ts->tv_nsec += offset64->tv_nsec; >> + ts->tv_sec += offset64->tv_sec; >> + if (ts->tv_nsec >= NSEC_PER_SEC) { >> + ts->tv_nsec -= NSEC_PER_SEC; >> + ts->tv_sec++; >> + } >> + if (ts->tv_nsec < 0) { >> + ts->tv_nsec += NSEC_PER_SEC; >> + ts->tv_sec--; >> + } > > That's broken for 32bit user space on 64bit hosts. On LE due to > misalignment and on BE because 32bit will read always 0. Ugh, will look into that. Thanks, Dmitry