Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751488AbaJ0Ftd (ORCPT ); Mon, 27 Oct 2014 01:49:33 -0400 Received: from mail-pa0-f42.google.com ([209.85.220.42]:63787 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752027AbaJ0FrS (ORCPT ); Mon, 27 Oct 2014 01:47:18 -0400 From: "pang.xunlei" To: linux-kernel@vger.kernel.org, rtc-linux@googlegroups.com Cc: John Stultz , Thomas Gleixner , Alessandro Zummo , "pang.xunlei" Subject: [PATCH RFC 04/12] time: Add rtc_tm_to_time() safe version(using time64_t) Date: Mon, 27 Oct 2014 13:46:34 +0800 Message-Id: <1414388802-5866-3-git-send-email-pang.xunlei@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1414388802-5866-1-git-send-email-pang.xunlei@linaro.org> References: <1414388802-5866-1-git-send-email-pang.xunlei@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The kernel uses 32-bit signed value(time_t) for seconds since 1970-01-01:00:00:00, thus it will overflow at 2038-01-19 03:14:08 on 32-bit systems. We call this "2038 safety" issue. As part of addressing 2038 saftey for in-kernel uses, this patch adds the safe rtc_tm_to_time() using time64_t. After this patch, rtc_tm_to_time_unsafe() should be replaced by rtc_tm_to_time() one by one. Eventually, rtc_tm_to_time_unsafe() will be removed from the kernel when it has no users. Signed-off-by: pang.xunlei --- drivers/rtc/rtc-lib.c | 9 +++++++++ include/linux/rtc.h | 1 + 2 files changed, 10 insertions(+) diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c index 168d2a2..829eef8 100644 --- a/drivers/rtc/rtc-lib.c +++ b/drivers/rtc/rtc-lib.c @@ -111,6 +111,15 @@ EXPORT_SYMBOL(rtc_valid_tm); /* * Convert Gregorian date to seconds since 01-01-1970 00:00:00. */ +int rtc_tm_to_time(struct rtc_time *tm, time64_t *time) +{ + *time = mktime(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, + tm->tm_hour, tm->tm_min, tm->tm_sec); + return 0; +} +EXPORT_SYMBOL(rtc_tm_to_time); + +/* TODO: [2038 safety] unsafe for legacy, and should be replaced by rtc_tm_to_time() */ int rtc_tm_to_time_unsafe(struct rtc_time *tm, unsigned long *time) { *time = (unsigned long) mktime(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, diff --git a/include/linux/rtc.h b/include/linux/rtc.h index 97bbb6f..ffd22e9 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -19,6 +19,7 @@ extern int rtc_month_days(unsigned int month, unsigned int year); extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year); extern int rtc_valid_tm(struct rtc_time *tm); +extern int rtc_tm_to_time(struct rtc_time *tm, time64_t *time); extern int rtc_tm_to_time_unsafe(struct rtc_time *tm, unsigned long *time); extern void rtc_time_to_tm(unsigned long time, struct rtc_time *tm); ktime_t rtc_tm_to_ktime(struct rtc_time tm); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/