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=-3.6 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,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 5F844C31E50 for ; Sun, 16 Jun 2019 17:43:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 279DB2145D for ; Sun, 16 Jun 2019 17:43:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="sr2VHyKH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727319AbfFPRnz (ORCPT ); Sun, 16 Jun 2019 13:43:55 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:52976 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726069AbfFPRny (ORCPT ); Sun, 16 Jun 2019 13:43:54 -0400 Received: by mail-wm1-f65.google.com with SMTP id s3so6932440wms.2; Sun, 16 Jun 2019 10:43:52 -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=que2swj0V47qMw6o/7WuGeIOPLMG0y81yFWSWpROV4I=; b=sr2VHyKHuKA0dnTZCgPBIHaROyB60v/TFp3jvmeh9zHh4UdGBiZEj6s2Da59R/KTCi zRkmUMxYcdl6nG36OxJI1Xa3QzD8MYrUxbPhvJ1HBWHK1cXUyTBogO1g7Lmrr/yYs7ur P7vFT5ydVUqCb0Et6dUrutZ/TckfzLNxTJ8PPD8TrpNurkHcy09YDW2Xi9SA4qhYr7JO LsvSObG99o64reQkzeEo4okgkdOwj0igpsavL21HkCQHLs2AJGSXttlaJcaQvtHbnwE5 fEnsOLPcQY/78BLWOebWOvv4PECbWxlK9PSmVBML9VyNc+59nZYhqIRBY2KZahJ7YjKK ju7w== 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=que2swj0V47qMw6o/7WuGeIOPLMG0y81yFWSWpROV4I=; b=s1zkw4hczp+iE7TbVwGUTPU5DdVEyVUyaNrjnu0Nggrx+2ybZ2TVPYpm2ATym51cIH MNg/NbDVC8zZUGXL3kB4IYoCOOxpQHwI6nSHsxXqkxVl8SO5CsMF+qeaBbZJVCaVnYAx APoH3AjTjlqjqlqdBeo1jri4eib6JT4lvICNQExCxF0t0ES2mK8bscDpy2iK78nzCPNl EgNTztseqV66tuv5D4AowJN/bufYRAISr2BpZPBkwxJvGVxn20WIQ3Ke6i75MuEzYgVY vPyUPpq2twy7tQJNd8yDz4JD9CwSylwC0GzfzI1NXisurwW5mksy74u2zT3OILTKkM+Y 2ugQ== X-Gm-Message-State: APjAAAXE4G3JyMsdFD2OKOTmPMqH6lvsD4p6bOIfbnaziOj9vER8mZQt ruOAHRXh2kFd5ODy5oyVozA= X-Google-Smtp-Source: APXvYqxuP6NBzLcQgq1Gfqfr/NPBip/sbjxzKzIOOw08EaRxZGa9wPyF1gU8Tar4EBtrnXvdhRX4FQ== X-Received: by 2002:a7b:cb84:: with SMTP id m4mr16663973wmi.50.1560707032125; Sun, 16 Jun 2019 10:43:52 -0700 (PDT) Received: from [10.83.36.153] ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id a81sm14875836wmh.3.2019.06.16.10.43.50 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Sun, 16 Jun 2019 10:43:51 -0700 (PDT) Subject: Re: [PATCHv4 06/28] timerfd/timens: Take into account ns clock offsets To: Thomas Gleixner , Dmitry Safonov Cc: linux-kernel@vger.kernel.org, Andrei Vagin , 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 References: <20190612192628.23797-1-dima@arista.com> <20190612192628.23797-7-dima@arista.com> From: Dmitry Safonov <0x7f454c46@gmail.com> Message-ID: Date: Sun, 16 Jun 2019 18:43:49 +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 2:37 PM, Thomas Gleixner wrote: > On Wed, 12 Jun 2019, Dmitry Safonov wrote: >> --- >> fs/timerfd.c | 3 +++ >> include/linux/time_namespace.h | 18 ++++++++++++++++++ >> kernel/time_namespace.c | 27 +++++++++++++++++++++++++++ >> 3 files changed, 48 insertions(+) > > Again, please split that into: > > 1) Introduce the new function > > 2) Make use of it Will do > >> diff --git a/fs/timerfd.c b/fs/timerfd.c >> index 6a6fc8aa1de7..9b0c2f65e7e8 100644 >> --- a/fs/timerfd.c >> +++ b/fs/timerfd.c >> @@ -26,6 +26,7 @@ >> #include >> #include >> #include >> +#include >> >> struct timerfd_ctx { >> union { >> @@ -196,6 +197,8 @@ static int timerfd_setup(struct timerfd_ctx *ctx, int flags, >> } >> >> if (texp != 0) { >> + if (flags & TFD_TIMER_ABSTIME) >> + texp = timens_ktime_to_host(clockid, texp); >> if (isalarm(ctx)) { >> if (flags & TFD_TIMER_ABSTIME) >> alarm_start(&ctx->t.alarm, texp); >> diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h >> index 1dda8af6b9fe..d32b55fad953 100644 >> --- a/include/linux/time_namespace.h >> +++ b/include/linux/time_namespace.h >> @@ -56,6 +56,19 @@ static inline void timens_add_boottime(struct timespec64 *ts) >> *ts = timespec64_add(*ts, ns_offsets->boottime); >> } >> >> +ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim, >> + struct timens_offsets *offsets); >> +static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim) >> +{ >> + struct timens_offsets *offsets = current->nsproxy->time_ns->offsets; >> + >> + if (!offsets) /* fast-path for the root time namespace */ > > Can you please avoid tail comments. They break the reading flow. Aside of > that I don't see the value of documenting the obvious. > >> +ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim, struct timens_offsets *ns_offsets) > > Please line break the arguments > > ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim, > struct timens_offsets *ns_offsets) Sure > >> +{ >> + ktime_t koff; >> + >> + switch (clockid) { >> + case CLOCK_MONOTONIC: >> + koff = timespec64_to_ktime(ns_offsets->monotonic); >> + break; >> + case CLOCK_BOOTTIME: >> + case CLOCK_BOOTTIME_ALARM: >> + koff = timespec64_to_ktime(ns_offsets->boottime); >> + break; >> + default: >> + return tim; >> + } >> + >> + /* tim - off has to be in [0, KTIME_MAX) */ > > Please be more elaborate why the below conditions can happen at all. > >> + if (tim < koff) >> + tim = 0; >> + else if (KTIME_MAX - tim < -koff) >> + tim = KTIME_MAX; >> + else >> + tim = ktime_sub(tim, koff); Thanks, Dmitry