From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753912AbcADWRU (ORCPT ); Mon, 4 Jan 2016 17:17:20 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39285 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752526AbcADWRO (ORCPT ); Mon, 4 Jan 2016 17:17:14 -0500 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [RFC PATCH 2/4] Handle ISO 8601 leap seconds and encodings of midnight in mktime64() From: David Howells To: keyrings@vger.kernel.org Cc: dhowells@redhat.com, linux-security-module@vger.kernel.org, John Stultz , linux-kernel@vger.kernel.org, Arnd Bergmann Date: Mon, 04 Jan 2016 22:17:12 +0000 Message-ID: <20160104221712.19818.69327.stgit@warthog.procyon.org.uk> In-Reply-To: <20160104221658.19818.56223.stgit@warthog.procyon.org.uk> References: <20160104221658.19818.56223.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Handle the following ISO 8601 features in mktime64(): (1) Leap seconds. Leap seconds are indicated by the seconds parameter being the value 60. Handle this by treating it the same as 00 of the following minute. (2) Alternate encodings of midnight. Two different encodings of midnight are permitted - 00:00:00 and 24:00:00 - the first is midnight today and the second is midnight tomorrow and is exactly equivalent to the first with tomorrow's date. As it happens, we don't actually need to change mktime64() to handle either of these - just comment them as valid parameters. These facility will be used by the X.509 parser. Doing it in mktime64() makes the policy common to the whole kernel and easier to find. Signed-off-by: David Howells cc: Arnd Bergmann cc: John Stultz --- kernel/time/time.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/kernel/time/time.c b/kernel/time/time.c index 86751c68e08d..be115b020d27 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -322,6 +322,13 @@ EXPORT_SYMBOL(timespec_trunc); * -year/100+year/400 terms, and add 10.] * * This algorithm was first published by Gauss (I think). + * + * A leap second can be indicated by calling this function with sec as + * 60 (allowable under ISO 8601). The leap second is treated the same + * as the following second since they don't exist in UNIX time. + * + * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight + * tomorrow - (allowable under ISO 8601) is supported. */ time64_t mktime64(const unsigned int year0, const unsigned int mon0, const unsigned int day, const unsigned int hour, @@ -338,7 +345,7 @@ time64_t mktime64(const unsigned int year0, const unsigned int mon0, return ((((time64_t) (year/4 - year/100 + year/400 + 367*mon/12 + day) + year*365 - 719499 - )*24 + hour /* now have hours */ + )*24 + hour /* now have hours - midnight tomorrow handled here */ )*60 + min /* now have minutes */ )*60 + sec; /* finally seconds */ }