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=-2.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_NEOMUTT 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 27BDBC4360F for ; Thu, 4 Apr 2019 03:15:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DFCC82147C for ; Thu, 4 Apr 2019 03:15:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SyLIflsc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726624AbfDDDO7 (ORCPT ); Wed, 3 Apr 2019 23:14:59 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:36275 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726218AbfDDDO7 (ORCPT ); Wed, 3 Apr 2019 23:14:59 -0400 Received: by mail-pg1-f194.google.com with SMTP id 85so485370pgc.3; Wed, 03 Apr 2019 20:14:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=8TQ40qmDazPJecSGF8d1lVR7pVACTEC++D5hm/cHmS0=; b=SyLIflscTDUxNnVZoEyWuD7RhWKez6brnvftDRcsHVFsaXWyKepW38EXB4JqKI/uop yghJtcMZ+su+IEz9FLOVJ5tYxDWgVsMLFppHZ1uSnV9aC9I2m5iICLd0s8K8lJ6qNG+h CVDzffzErSvoA/y7tjphQtiikeNfXRQ4zU5oaj2Kha9TumQ0ZxM6OIk28WQTTh6dIVou z/FsA4KC7POcCqb9zxAHb4iKoZgbzgFpF1uOwmWeNe1iZqmoSLZ7yQQjnZ+0hz6YwJs/ 1YStbtpHfERx3MzZMyDpJms35VX6qLE16cVdhKBYcXfjkOCbBGMrbJrXbyx0zpF/scqW kJcg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=8TQ40qmDazPJecSGF8d1lVR7pVACTEC++D5hm/cHmS0=; b=UB6PxNwdyCF20LHVUVphajOGmHqYiS6I9u2IcNpBMsaTc3heAgPXboBO0nYEexW4fr Nst4/3qydGmSCirhJdircax/pz6nL7rZy/P91hQlF/aO14WKlNzxdaZrXAjIZ8+mv1W6 wzQv5GtQYylZk5jVW4LeBNXaQFhMo21sMlFMLDZMkY7kkW/273TgXg1zEDI03lzDuzQT pMbVVwbLONtamW7GSakgxMACm+eZyIY4L/p//yvHm+Z6Lxb5fGKU6OoH9AeMTa+F9xne QNcV/HzE/8kVmODdaXYHuBrUVXXOtzdB9pzhsV+laoQh3rXBmWtSl2z+sBxL4JBNG9Sz +bTQ== X-Gm-Message-State: APjAAAXGtD0kbYazKIYPElywmwNpEfuCBY1qhDMubbOl4A88ubtibx72 npB0HXG9C3hXQsaEvujWSxs= X-Google-Smtp-Source: APXvYqz9CcjRFhkOKUrZaHilUMRABwGeQXyCG7lKc3fBtEf0n2EPVNmDxI6JxCzNmZcvZfS/Rg51cA== X-Received: by 2002:a63:6f0a:: with SMTP id k10mr3337473pgc.78.1554347698138; Wed, 03 Apr 2019 20:14:58 -0700 (PDT) Received: from localhost (c-73-222-71-142.hsd1.ca.comcast.net. [73.222.71.142]) by smtp.gmail.com with ESMTPSA id f14sm21974316pfn.3.2019.04.03.20.14.57 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 03 Apr 2019 20:14:57 -0700 (PDT) Date: Wed, 3 Apr 2019 20:14:55 -0700 From: Richard Cochran To: Siddaraju D H Cc: john.stultz@linaro.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ptp/ptp_clock.c: Correct input parameter range check Message-ID: <20190404031455.cn4cc5wxbn6izvwe@localhost> References: <20190404000958.15236-1-siddarajudh@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190404000958.15236-1-siddarajudh@gmail.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 04, 2019 at 05:39:58AM +0530, Siddaraju D H wrote: > From: Siddaraju DH > > The ealier implementaion used to return EINVAL for -ve adjustments > in the range -1ns to -999999999ns as these -ve numbers will fail the > unsigned comaparison against NSEC_PER_SEC. Since the tv_sec field > will be ZERO in this range, the user will not be able to specify > the signedness of adjustment through the tv_sec field. NAK, the tv_sec field can be set to -1. See the example, below. Thanks, Richard void clockadj_step(clockid_t clkid, int64_t step) { struct timex tx; int sign = 1; if (step < 0) { sign = -1; step *= -1; } memset(&tx, 0, sizeof(tx)); tx.modes = ADJ_SETOFFSET | ADJ_NANO; tx.time.tv_sec = sign * (step / NS_PER_SEC); tx.time.tv_usec = sign * (step % NS_PER_SEC); /* * The value of a timeval is the sum of its fields, but the * field tv_usec must always be non-negative. */ if (tx.time.tv_usec < 0) { tx.time.tv_sec -= 1; tx.time.tv_usec += 1000000000; } if (clock_adjtime(clkid, &tx) < 0) pr_err("failed to step clock: %m"); }