Commit c2c11ae4 authored by pang.xunlei's avatar pang.xunlei Committed by John Stultz
Browse files

rtc/lib: Provide y2038 safe rtc_tm_to_time()/rtc_time_to_tm() replacement 



As part of addressing "y2038 problem" for in-kernel uses, this patch
adds safe rtc_tm_to_time64()/rtc_time64_to_tm() respectively using
time64_t.

After this patch, rtc_tm_to_time() is deprecated and all its call
sites will be fixed using corresponding safe versions, it can be
removed when having no users. Also change rtc_tm_to_time64() to
return time64_t directly instead of just as a parameter like
rtc_tm_to_time() does.

After this patch, rtc_time_to_tm() is deprecated and all its call
sites will be fixed using corresponding safe versions, it can be
removed when having no users.

In addition, change rtc_tm_to_ktime() and rtc_ktime_to_tm() to use
the safe version in passing.

Signed-off-by: default avatarpang.xunlei <pang.xunlei@linaro.org>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent 5322e4c2

drivers/rtc/rtc-lib.c

+20 −18
Original line number Diff line number Diff line
@@ -45,16 +45,20 @@ int rtc_year_days(unsigned int day, unsigned int month, unsigned int year) 
}

EXPORT_SYMBOL(rtc_year_days);





/*

 * rtc_time_to_tm64 - Converts time64_t to rtc_time.

 * Convert seconds since 01-01-1970 00:00:00 to Gregorian date.

 */

void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)

void rtc_time64_to_tm(time64_t time, struct rtc_time *tm)

{

	unsigned int month, year;

	unsigned long secs;

	int days;



	days = time / 86400;

	time -= (unsigned int) days * 86400;

	/* time must be positive */

	days = div_s64(time, 86400);

	secs = time - (unsigned int) days * 86400;



	/* day of the week, 1970-01-01 was a Thursday */

	tm->tm_wday = (days + 4) % 7;
@@ -81,14 +85,14 @@ void rtc_time_to_tm(unsigned long time, struct rtc_time *tm) 
	tm->tm_mon = month;

	tm->tm_mday = days + 1;



	tm->tm_hour = time / 3600;

	time -= tm->tm_hour * 3600;

	tm->tm_min = time / 60;

	tm->tm_sec = time - tm->tm_min * 60;

	tm->tm_hour = secs / 3600;

	secs -= tm->tm_hour * 3600;

	tm->tm_min = secs / 60;

	tm->tm_sec = secs - tm->tm_min * 60;



	tm->tm_isdst = 0;

}

EXPORT_SYMBOL(rtc_time_to_tm);

EXPORT_SYMBOL(rtc_time64_to_tm);



/*

 * Does the rtc_time represent a valid date/time?
@@ -109,24 +113,22 @@ int rtc_valid_tm(struct rtc_time *tm) 
EXPORT_SYMBOL(rtc_valid_tm);



/*

 * rtc_tm_to_time64 - Converts rtc_time to time64_t.

 * Convert Gregorian date to seconds since 01-01-1970 00:00:00.

 */

int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)

time64_t rtc_tm_to_time64(struct rtc_time *tm)

{

	*time = mktime(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,

	return mktime64(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,

			tm->tm_hour, tm->tm_min, tm->tm_sec);

	return 0;

}

EXPORT_SYMBOL(rtc_tm_to_time);

EXPORT_SYMBOL(rtc_tm_to_time64);



/*

 * Convert rtc_time to ktime

 */

ktime_t rtc_tm_to_ktime(struct rtc_time tm)

{

	time_t time;

	rtc_tm_to_time(&tm, &time);

	return ktime_set(time, 0);

	return ktime_set(rtc_tm_to_time64(&tm), 0);

}

EXPORT_SYMBOL_GPL(rtc_tm_to_ktime);
@@ -135,14 +137,14 @@ EXPORT_SYMBOL_GPL(rtc_tm_to_ktime); 
 */

struct rtc_time rtc_ktime_to_tm(ktime_t kt)

{

	struct timespec ts;

	struct timespec64 ts;

	struct rtc_time ret;



	ts = ktime_to_timespec(kt);

	ts = ktime_to_timespec64(kt);

	/* Round up any ns */

	if (ts.tv_nsec)

		ts.tv_sec++;

	rtc_time_to_tm(ts.tv_sec, &ret);

	rtc_time64_to_tm(ts.tv_sec, &ret);

	return ret;

}

EXPORT_SYMBOL_GPL(rtc_ktime_to_tm);

include/linux/rtc.h

+19 −2
Original line number Diff line number Diff line
@@ -19,11 +19,28 @@ 
extern int rtc_month_days(unsigned int month, unsigned int year);

extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);

extern int rtc_valid_tm(struct rtc_time *tm);

extern int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time);

extern void rtc_time_to_tm(unsigned long time, struct rtc_time *tm);

extern time64_t rtc_tm_to_time64(struct rtc_time *tm);

extern void rtc_time64_to_tm(time64_t time, struct rtc_time *tm);

ktime_t rtc_tm_to_ktime(struct rtc_time tm);

struct rtc_time rtc_ktime_to_tm(ktime_t kt);



/**

 * Deprecated. Use rtc_time64_to_tm().

 */

static inline void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)

{

	rtc_time64_to_tm(time, tm);

}



/**

 * Deprecated. Use rtc_tm_to_time64().

 */

static inline int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)

{

	*time = rtc_tm_to_time64(tm);



	return 0;

}



#include <linux/device.h>

#include <linux/seq_file.h>

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