The function "second_overflow" uses "unsign long"
as its input parameter type which will overflow after
year 2106 on 32bit systems.
Replace it with time64_t type.
Because 64-bit division is expensive, since "next_ntp_leap_sec"
has been calculated already, we can just re-use it in the
TIME_INS/DEL cases instead of re-doing divsion which may occur
once a second.
Signed-off-by: DengChao <chao.d...@linaro.org>
---
kernel/time/ntp.c | 16 +++++++++-------
kernel/time/ntp_internal.h | 2 +-
2 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 149cc80..37479305 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -16,6 +16,7 @@
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/rtc.h>
+#include <linux/math64.h>
#include "ntp_internal.h"
@@ -390,10 +391,11 @@ ktime_t ntp_get_next_leap(void)
*
* Also handles leap second processing, and returns leap offset
*/
-int second_overflow(unsigned long secs)
+int second_overflow(time64_t secs)
{
s64 delta;
int leap = 0;
+ s32 rem;
/*
* Leap second processing. If in leap-insert state at the end of the
@@ -404,19 +406,19 @@ int second_overflow(unsigned long secs)
case TIME_OK:
if (time_status & STA_INS) {
time_state = TIME_INS;
- ntp_next_leap_sec = secs + SECS_PER_DAY -
- (secs % SECS_PER_DAY);
+ div_s64_rem(secs, SECS_PER_DAY, &rem);
+ ntp_next_leap_sec = secs + SECS_PER_DAY - rem;
} else if (time_status & STA_DEL) {
time_state = TIME_DEL;
- ntp_next_leap_sec = secs + SECS_PER_DAY -
- ((secs+1) % SECS_PER_DAY);
+ div_s64_rem(secs + 1, SECS_PER_DAY, &rem);
+ ntp_next_leap_sec = secs + SECS_PER_DAY - rem;
}
break;
case TIME_INS:
if (!(time_status & STA_INS)) {
ntp_next_leap_sec = TIME64_MAX;
time_state = TIME_OK;
- } else if (secs % SECS_PER_DAY == 0) {
+ } else if (secs == ntp_next_leap_sec) {
leap = -1;
time_state = TIME_OOP;
printk(KERN_NOTICE
@@ -427,7 +429,7 @@ int second_overflow(unsigned long secs)
if (!(time_status & STA_DEL)) {
ntp_next_leap_sec = TIME64_MAX;
time_state = TIME_OK;
- } else if ((secs + 1) % SECS_PER_DAY == 0) {
+ } else if (secs == ntp_next_leap_sec) {
leap = 1;
ntp_next_leap_sec = TIME64_MAX;
time_state = TIME_WAIT;
diff --git a/kernel/time/ntp_internal.h b/kernel/time/ntp_internal.h
index af92447..d8a7c11 100644
--- a/kernel/time/ntp_internal.h
+++ b/kernel/time/ntp_internal.h
@@ -6,7 +6,7 @@ extern void ntp_clear(void);
/* Returns how long ticks are at present, in ns / 2^NTP_SCALE_SHIFT. */
extern u64 ntp_tick_length(void);
extern ktime_t ntp_get_next_leap(void);
-extern int second_overflow(unsigned long secs);
+extern int second_overflow(time64_t secs);
extern int ntp_validate_timex(struct timex *);
extern int __do_adjtimex(struct timex *, struct timespec64 *, s32 *);
extern void __hardpps(const struct timespec64 *, const struct timespec64 *);
--
1.9.1
--
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