From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753768AbcJESwv (ORCPT ); Wed, 5 Oct 2016 14:52:51 -0400 Received: from mga09.intel.com ([134.134.136.24]:31719 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753075AbcJESwu (ORCPT ); Wed, 5 Oct 2016 14:52:50 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,302,1473145200"; d="scan'208";a="17020445" From: Andrew Kim To: linux-kernel@vger.kernel.org Subject: [PATCH 1/1] rtc: add century field data boundary Date: Wed, 5 Oct 2016 11:48:16 -0700 Message-Id: <1475693296-36053-1-git-send-email-andrew.kim@intel.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org According to ACPI specification, the century field data should be ranged 0-63. so if it's over this range, it could cause system RTC settings error including alarmwakeup settings. So it's required to have this boundary for safe RTC init settings. Signed-off-by: Andrew Kim --- arch/x86/kernel/rtc.c | 5 ++++- drivers/rtc/rtc-mc146818-lib.c | 5 ++++- include/linux/mc146818rtc.h | 2 ++ 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c index 79c6311c..795a9ab 100644 --- a/arch/x86/kernel/rtc.c +++ b/arch/x86/kernel/rtc.c @@ -84,8 +84,11 @@ void mach_get_cmos_time(struct timespec *now) #ifdef CONFIG_ACPI if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && - acpi_gbl_FADT.century) + acpi_gbl_FADT.century) { century = CMOS_READ(acpi_gbl_FADT.century); + if (century > RTC_CENTURY_LIMIT) + century = 0; + } #endif status = CMOS_READ(RTC_CONTROL); diff --git a/drivers/rtc/rtc-mc146818-lib.c b/drivers/rtc/rtc-mc146818-lib.c index 2f1772a..81eb2a2 100644 --- a/drivers/rtc/rtc-mc146818-lib.c +++ b/drivers/rtc/rtc-mc146818-lib.c @@ -61,8 +61,11 @@ unsigned int mc146818_get_time(struct rtc_time *time) #endif #ifdef CONFIG_ACPI if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && - acpi_gbl_FADT.century) + acpi_gbl_FADT.century) { century = CMOS_READ(acpi_gbl_FADT.century); + if (century > RTC_CENTURY_LIMIT) + century = 0; + } #endif ctrl = CMOS_READ(RTC_CONTROL); spin_unlock_irqrestore(&rtc_lock, flags); diff --git a/include/linux/mc146818rtc.h b/include/linux/mc146818rtc.h index a585b4b..199065a 100644 --- a/include/linux/mc146818rtc.h +++ b/include/linux/mc146818rtc.h @@ -122,6 +122,8 @@ struct cmos_rtc_board_info { #define RTC_IO_EXTENT_USED RTC_IO_EXTENT #endif /* ARCH_RTC_LOCATION */ +#define RTC_CENTURY_LIMIT 0x3F + unsigned int mc146818_get_time(struct rtc_time *time); int mc146818_set_time(struct rtc_time *time); -- 1.9.1