Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 2ee96632 authored by Xunlei Pang's avatar Xunlei Pang Committed by Ingo Molnar
Browse files

time: Add y2038 safe read_persistent_clock64() 



As part of addressing in-kernel y2038 issues, this patch adds
read_persistent_clock64() and replaces all the call sites of
read_persistent_clock() with this function. This is a __weak
implementation, which simply calls the existing y2038 unsafe
read_persistent_clock().

This allows architecture specific implementations to be
converted independently, and eventually the y2038 unsafe
read_persistent_clock() can be removed after all its
architecture specific implementations have been converted to
read_persistent_clock64().

Suggested-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarXunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427945681-29972-3-git-send-email-john.stultz@linaro.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 9a806ddb

arch/mips/lasat/sysctl.c

+2 −2
Original line number Diff line number Diff line
@@ -75,11 +75,11 @@ static int rtctmp; 
int proc_dolasatrtc(struct ctl_table *table, int write,

		       void *buffer, size_t *lenp, loff_t *ppos)

{

	struct timespec ts;

	struct timespec64 ts;

	int r;



	if (!write) {

		read_persistent_clock(&ts);

		read_persistent_clock64(&ts);

		rtctmp = ts.tv_sec;

		/* check for time < 0 and set to 0 */

		if (rtctmp < 0)

include/linux/timekeeping.h

+1 −0
Original line number Diff line number Diff line
@@ -268,6 +268,7 @@ static inline bool has_persistent_clock(void) 
}



extern void read_persistent_clock(struct timespec *ts);

extern void read_persistent_clock64(struct timespec64 *ts);

extern void read_boot_clock(struct timespec *ts);

extern void read_boot_clock64(struct timespec64 *ts);

extern int update_persistent_clock(struct timespec now);

kernel/time/timekeeping.c

+12 −10
Original line number Diff line number Diff line
@@ -1173,6 +1173,14 @@ void __weak read_persistent_clock(struct timespec *ts) 
	ts->tv_nsec = 0;

}



void __weak read_persistent_clock64(struct timespec64 *ts64)

{

	struct timespec ts;



	read_persistent_clock(&ts);

	*ts64 = timespec_to_timespec64(ts);

}



/**

 * read_boot_clock -  Return time of the system start.

 *
@@ -1205,10 +1213,8 @@ void __init timekeeping_init(void) 
	struct clocksource *clock;

	unsigned long flags;

	struct timespec64 now, boot, tmp;

	struct timespec ts;



	read_persistent_clock(&ts);

	now = timespec_to_timespec64(ts);

	read_persistent_clock64(&now);

	if (!timespec64_valid_strict(&now)) {

		pr_warn("WARNING: Persistent clock returned invalid value!\n"

			"         Check your CMOS/BIOS settings.\n");
@@ -1278,7 +1284,7 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk, 
 * timekeeping_inject_sleeptime64 - Adds suspend interval to timeekeeping values

 * @delta: pointer to a timespec64 delta value

 *

 * This hook is for architectures that cannot support read_persistent_clock

 * This hook is for architectures that cannot support read_persistent_clock64

 * because their RTC/persistent clock is only accessible when irqs are enabled.

 *

 * This function should only be called by rtc_resume(), and allows
@@ -1325,12 +1331,10 @@ void timekeeping_resume(void) 
	struct clocksource *clock = tk->tkr_mono.clock;

	unsigned long flags;

	struct timespec64 ts_new, ts_delta;

	struct timespec tmp;

	cycle_t cycle_now, cycle_delta;

	bool suspendtime_found = false;



	read_persistent_clock(&tmp);

	ts_new = timespec_to_timespec64(tmp);

	read_persistent_clock64(&ts_new);



	clockevents_resume();

	clocksource_resume();
@@ -1406,10 +1410,8 @@ int timekeeping_suspend(void) 
	unsigned long flags;

	struct timespec64		delta, delta_delta;

	static struct timespec64	old_delta;

	struct timespec tmp;



	read_persistent_clock(&tmp);

	timekeeping_suspend_time = timespec_to_timespec64(tmp);

	read_persistent_clock64(&timekeeping_suspend_time);



	/*

	 * On some systems the persistent_clock can not be detected at