Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752456AbaJ0Frx (ORCPT ); Mon, 27 Oct 2014 01:47:53 -0400 Received: from mail-pa0-f50.google.com ([209.85.220.50]:40764 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752352AbaJ0Fru (ORCPT ); Mon, 27 Oct 2014 01:47:50 -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 11/12] time: Convert xen_read_wallclock() to use timespec64 Date: Mon, 27 Oct 2014 13:46:41 +0800 Message-Id: <1414388802-5866-10-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, so 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 safety for in-kernel uses, this patch creates no functional change in existing users, converts xen_read_wallclock() to use timespec64 instead of timespec. Signed-off-by: pang.xunlei --- arch/x86/xen/time.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index cf1b591..2ce064a 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -169,20 +169,33 @@ static cycle_t xen_clocksource_get_cycles(struct clocksource *cs) return xen_clocksource_read(); } -static void xen_read_wallclock(struct timespec *ts) +static void xen_read_wallclock(struct timespec64 *ts) { + struct timespec ts32; struct shared_info *s = HYPERVISOR_shared_info; struct pvclock_wall_clock *wall_clock = &(s->wc); struct pvclock_vcpu_time_info *vcpu_time; vcpu_time = &get_cpu_var(xen_vcpu)->time; - pvclock_read_wallclock(wall_clock, vcpu_time, ts); + /* + * TODO: [2038 safety] pvclock_read_wallclock() should be changed + * to use timespec64 for 2038 safety as soon as possible. + */ + pvclock_read_wallclock(wall_clock, vcpu_time, &ts32); + *ts = timespec_to_timespec64(ts32); put_cpu_var(xen_vcpu); } +/* + * TODO: [2038 safety] xen_get_wallclock() should be changed to use + * timespec64 for 2038 safety as soon as possible. + */ static void xen_get_wallclock(struct timespec *now) { - xen_read_wallclock(now); + struct timespec64 now64; + + xen_read_wallclock(&now64); + *now = timespec64_to_timespec(now64); } static int xen_set_wallclock(const struct timespec *now) @@ -485,8 +498,7 @@ static const struct pv_time_ops xen_time_ops __initconst = { static void __init xen_time_init(void) { int cpu = smp_processor_id(); - struct timespec tp; - struct timespec64 tp64; + struct timespec64 tp; clocksource_register_hz(&xen_clocksource, NSEC_PER_SEC); @@ -497,14 +509,9 @@ static void __init xen_time_init(void) xen_clockevent = &xen_vcpuop_clockevent; } - /* - * Set initial system time with full resolution. - * TODO: [2038 safety] xen_read_wallclock() should be changed to use - * timespec64 for 2038 safety as soon as possible. - */ + /* Set initial system time with full resolution. */ xen_read_wallclock(&tp); - tp64 = timespec_to_timespec64(tp); - do_settimeofday(&tp64); + do_settimeofday(&tp); setup_force_cpu_cap(X86_FEATURE_TSC); -- 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/