Messages in this thread Patch in this message | | | From | "pang.xunlei" <> | Subject | [PATCH RFC 11/12] time: Convert xen_read_wallclock() to use timespec64 | Date | Mon, 27 Oct 2014 13:46:41 +0800 |
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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 <pang.xunlei@linaro.org> --- 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
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