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.xun...@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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
