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=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 9CA43C43461 for ; Mon, 14 Sep 2020 19:38:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64D97207EA for ; Mon, 14 Sep 2020 19:38:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IO6wp6FT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725961AbgINTid (ORCPT ); Mon, 14 Sep 2020 15:38:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725914AbgINTib (ORCPT ); Mon, 14 Sep 2020 15:38:31 -0400 Received: from mail-oi1-x242.google.com (mail-oi1-x242.google.com [IPv6:2607:f8b0:4864:20::242]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B89B3C06174A for ; Mon, 14 Sep 2020 12:38:30 -0700 (PDT) Received: by mail-oi1-x242.google.com with SMTP id x19so1138410oix.3 for ; Mon, 14 Sep 2020 12:38:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc; bh=Aq8LWZc8f73ZtkExUBb19aY77hQM68tRUlfl3AXudEw=; b=IO6wp6FTG10bMfXCoatuR5t8iN+7KkTsg02WWrAsYvSJexCDb8NcIj09K+X0xSu/9/ 85KeA7WpSt65BMN8obtszkbNgAsdCS7HR5XIQq4AuTKts2z2UxOocNP3x9RmiM4gzKkD LvXHpYM3UUEdgrFg0v6jIvqwq9ljEGilZD05rQGQ27w/YIrseRFWicfEv8sfcKztEmJ/ k6gEWNO2DQlh62wuwr2Z9FzeKXb9Mv7QUVyDFsIR/a7AoZlNJ1rWW8v+1VMSbcKP8bMe bXzRcc+NnYOikGbyN4P7pvZlHWBDxPMDxLhkH11l4LdQNlJ82t/3bmdRwdo37VBm0RWR Gpug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to:cc; bh=Aq8LWZc8f73ZtkExUBb19aY77hQM68tRUlfl3AXudEw=; b=Js4FlPHi8T28vS0puDEF/u64c3Wyj1b673M9UGNNQddr109o77+v0rdWOia2J1+qfI uZ2kpuNOxpqDSyxKbWqOjn68DHs9TOLnQrzoG1XsRrMxJa8EM58Dh6aXo6XdlpOHh0FX 3SUvCvILGJGitRQoFfxTOJubPBg7KItmDtA9/YgjqQmYDq+GyaAp4ouN8d+QrGbxMPkl v/pKavgFUjtUFldQovMrTcMOVDxSsyiXPF1BRIEP5nWhpbkJpFC3FZo/vJFD7euLBFTy 0L2wfy7sxzQldFgjE6UfY9TDBKvEJLkaBAI1XSlS7ebM+18ZcsNtHaj6LBupXyWl7z4R O4AQ== X-Gm-Message-State: AOAM533i+sL68bjFmqYvUR5Q5jr4IMzctr49qhgjHVMz+OaWl8lwOcu8 DSr0IIalhziq0mJ94ljDKaZDxf1GvUQ2lubujRw= X-Google-Smtp-Source: ABdhPJzRDzhR/J5LMHJ170PScqHZ930gJLkAaGZscIDvtE2uqr/MDhnZNfktvrNEuj/SCabBchw/P4EkUf+eA89/0cY= X-Received: by 2002:aca:2301:: with SMTP id e1mr680540oie.177.1600112309698; Mon, 14 Sep 2020 12:38:29 -0700 (PDT) MIME-Version: 1.0 References: <20200911231411.28406-1-colomar.6.4.3@gmail.com> <20200911231411.28406-4-colomar.6.4.3@gmail.com> <20200914085831.pdvkioetcw7fe4l7@jwilk.net> In-Reply-To: <20200914085831.pdvkioetcw7fe4l7@jwilk.net> Reply-To: mtk.manpages@gmail.com From: "Michael Kerrisk (man-pages)" Date: Mon, 14 Sep 2020 21:38:18 +0200 Message-ID: Subject: Re: [PATCH 03/12] pthread_getcpuclockid.3: Cast 'time_t' to 'intmax_t' for printf() To: Jakub Wilk Cc: Alejandro Colomar , linux-man Content-Type: text/plain; charset="UTF-8" Sender: linux-man-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-man@vger.kernel.org Hi Jakub, On Mon, 14 Sep 2020 at 10:58, Jakub Wilk wrote: > > * Michael Kerrisk , 2020-09-13, 07:58: > >Casting to long is the historical practive here, and should be > >sufficient, don't you think? > > It general, the practice of casting time_t to long is wrong. There are > existing systems that have 64-bit time_t but 32-bit long. > > In this particular case, we're measuring CPU time, so there's > practically no danger of overflow. Yes, what you say makes sense. > I'd either cast it to int (to make the code shortest and simplest) or to > intmax_t (to be pedantically correct). As per the patch from Alex, we'll universally move to intmax_t/uintmax_t casts. Thanks, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/