Commit e0956dcc authored by Arnd Bergmann's avatar Arnd Bergmann Committed by John Stultz
Browse files

timekeeping: Consolidate timekeeping_inject_offset code 



The code to check the adjtimex() or clock_adjtime() arguments is spread
out across multiple files for presumably only historic reasons. As a
preparatation for a rework to get rid of the use of 'struct timeval'
and 'struct timespec' in there, this moves all the portions into
kernel/time/timekeeping.c and marks them as 'static'.

The warp_clock() function here is not as closely related as the others,
but I feel it still makes sense to move it here in order to consolidate
all callers of timekeeping_inject_offset().

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
[jstultz: Whitespace fixup]
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent 0f295b06

include/linux/time.h

+0 −26
Original line number Diff line number Diff line
@@ -134,32 +134,6 @@ static inline bool timeval_valid(const struct timeval *tv) 


extern struct timespec timespec_trunc(struct timespec t, unsigned gran);



/*

 * Validates if a timespec/timeval used to inject a time offset is valid.

 * Offsets can be postive or negative. The value of the timeval/timespec

 * is the sum of its fields, but *NOTE*: the field tv_usec/tv_nsec must

 * always be non-negative.

 */

static inline bool timeval_inject_offset_valid(const struct timeval *tv)

{

	/* We don't check the tv_sec as it can be positive or negative */



	/* Can't have more microseconds then a second */

	if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)

		return false;

	return true;

}



static inline bool timespec_inject_offset_valid(const struct timespec *ts)

{

	/* We don't check the tv_sec as it can be positive or negative */



	/* Can't have more nanoseconds then a second */

	if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)

		return false;

	return true;

}



/* Some architectures do not supply their own clocksource.

 * This is mainly the case in architectures that get their

 * inter-tick times by reading the counter on their interval

kernel/time/ntp.c

+0 −61
Original line number Diff line number Diff line
@@ -713,67 +713,6 @@ static inline void process_adjtimex_modes(struct timex *txc, 
}







/**

 * ntp_validate_timex - Ensures the timex is ok for use in do_adjtimex

 */

int ntp_validate_timex(struct timex *txc)

{

	if (txc->modes & ADJ_ADJTIME) {

		/* singleshot must not be used with any other mode bits */

		if (!(txc->modes & ADJ_OFFSET_SINGLESHOT))

			return -EINVAL;

		if (!(txc->modes & ADJ_OFFSET_READONLY) &&

		    !capable(CAP_SYS_TIME))

			return -EPERM;

	} else {

		/* In order to modify anything, you gotta be super-user! */

		 if (txc->modes && !capable(CAP_SYS_TIME))

			return -EPERM;

		/*

		 * if the quartz is off by more than 10% then

		 * something is VERY wrong!

		 */

		if (txc->modes & ADJ_TICK &&

		    (txc->tick <  900000/USER_HZ ||

		     txc->tick > 1100000/USER_HZ))

			return -EINVAL;

	}



	if (txc->modes & ADJ_SETOFFSET) {

		/* In order to inject time, you gotta be super-user! */

		if (!capable(CAP_SYS_TIME))

			return -EPERM;



		if (txc->modes & ADJ_NANO) {

			struct timespec ts;



			ts.tv_sec = txc->time.tv_sec;

			ts.tv_nsec = txc->time.tv_usec;

			if (!timespec_inject_offset_valid(&ts))

				return -EINVAL;



		} else {

			if (!timeval_inject_offset_valid(&txc->time))

				return -EINVAL;

		}

	}



	/*

	 * Check for potential multiplication overflows that can

	 * only happen on 64-bit systems:

	 */

	if ((txc->modes & ADJ_FREQUENCY) && (BITS_PER_LONG == 64)) {

		if (LLONG_MIN / PPM_SCALE > txc->freq)

			return -EINVAL;

		if (LLONG_MAX / PPM_SCALE < txc->freq)

			return -EINVAL;

	}



	return 0;

}





/*

 * adjtimex mainly allows reading (and writing, if superuser) of

 * kernel time-keeping variables. used by xntpd.

kernel/time/ntp_internal.h

+0 −1
Original line number Diff line number Diff line
@@ -7,7 +7,6 @@ extern void ntp_clear(void); 
extern u64 ntp_tick_length(void);

extern ktime_t ntp_get_next_leap(void);

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 *);

#endif /* _LINUX_NTP_INTERNAL_H */

kernel/time/time.c

+1 −35
Original line number Diff line number Diff line
@@ -157,40 +157,6 @@ SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv, 
	return 0;

}



/*

 * Indicates if there is an offset between the system clock and the hardware

 * clock/persistent clock/rtc.

 */

int persistent_clock_is_local;



/*

 * Adjust the time obtained from the CMOS to be UTC time instead of

 * local time.

 *

 * This is ugly, but preferable to the alternatives.  Otherwise we

 * would either need to write a program to do it in /etc/rc (and risk

 * confusion if the program gets run more than once; it would also be

 * hard to make the program warp the clock precisely n hours)  or

 * compile in the timezone information into the kernel.  Bad, bad....

 *

 *						- TYT, 1992-01-01

 *

 * The best thing to do is to keep the CMOS clock in universal time (UTC)

 * as real UNIX machines always do it. This avoids all headaches about

 * daylight saving times and warping kernel clocks.

 */

static inline void warp_clock(void)

{

	if (sys_tz.tz_minuteswest != 0) {

		struct timespec adjust;



		persistent_clock_is_local = 1;

		adjust.tv_sec = sys_tz.tz_minuteswest * 60;

		adjust.tv_nsec = 0;

		timekeeping_inject_offset(&adjust);

	}

}



/*

 * In case for some reason the CMOS clock has not already been running

 * in UTC, but in some local time: The first time we set the timezone,
@@ -224,7 +190,7 @@ int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz 
		if (firsttime) {

			firsttime = 0;

			if (!tv)

				warp_clock();

				timekeeping_warp_clock();

		}

	}

	if (tv)

kernel/time/timekeeping.c

+121 −2
Original line number Diff line number Diff line
@@ -1258,13 +1258,39 @@ out: 
}

EXPORT_SYMBOL(do_settimeofday64);



/*

 * Validates if a timespec/timeval used to inject a time offset is valid.

 * Offsets can be postive or negative. The value of the timeval/timespec

 * is the sum of its fields, but *NOTE*: the field tv_usec/tv_nsec must

 * always be non-negative.

 */

static inline bool timeval_inject_offset_valid(const struct timeval *tv)

{

	/* We don't check the tv_sec as it can be positive or negative */



	/* Can't have more microseconds then a second */

	if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)

		return false;

	return true;

}



static inline bool timespec_inject_offset_valid(const struct timespec *ts)

{

	/* We don't check the tv_sec as it can be positive or negative */



	/* Can't have more nanoseconds then a second */

	if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)

		return false;

	return true;

}



/**

 * timekeeping_inject_offset - Adds or subtracts from the current time.

 * @tv:		pointer to the timespec variable containing the offset

 *

 * Adds or subtracts an offset value from the current time.

 */

int timekeeping_inject_offset(struct timespec *ts)

static int timekeeping_inject_offset(struct timespec *ts)

{

	struct timekeeper *tk = &tk_core.timekeeper;

	unsigned long flags;
@@ -1303,7 +1329,40 @@ error: /* even if we error out, we forwarded the time, so call update */ 


	return ret;

}

EXPORT_SYMBOL(timekeeping_inject_offset);



/*

 * Indicates if there is an offset between the system clock and the hardware

 * clock/persistent clock/rtc.

 */

int persistent_clock_is_local;



/*

 * Adjust the time obtained from the CMOS to be UTC time instead of

 * local time.

 *

 * This is ugly, but preferable to the alternatives.  Otherwise we

 * would either need to write a program to do it in /etc/rc (and risk

 * confusion if the program gets run more than once; it would also be

 * hard to make the program warp the clock precisely n hours)  or

 * compile in the timezone information into the kernel.  Bad, bad....

 *

 *						- TYT, 1992-01-01

 *

 * The best thing to do is to keep the CMOS clock in universal time (UTC)

 * as real UNIX machines always do it. This avoids all headaches about

 * daylight saving times and warping kernel clocks.

 */

void timekeeping_warp_clock(void)

{

	if (sys_tz.tz_minuteswest != 0) {

		struct timespec adjust;



		persistent_clock_is_local = 1;

		adjust.tv_sec = sys_tz.tz_minuteswest * 60;

		adjust.tv_nsec = 0;

		timekeeping_inject_offset(&adjust);

	}

}



/**

 * __timekeeping_set_tai_offset - Sets the TAI offset from UTC and monotonic
@@ -2247,6 +2306,66 @@ ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real, 
	return base;

}



/**

 * ntp_validate_timex - Ensures the timex is ok for use in do_adjtimex

 */

static int ntp_validate_timex(struct timex *txc)

{

	if (txc->modes & ADJ_ADJTIME) {

		/* singleshot must not be used with any other mode bits */

		if (!(txc->modes & ADJ_OFFSET_SINGLESHOT))

			return -EINVAL;

		if (!(txc->modes & ADJ_OFFSET_READONLY) &&

		    !capable(CAP_SYS_TIME))

			return -EPERM;

	} else {

		/* In order to modify anything, you gotta be super-user! */

		if (txc->modes && !capable(CAP_SYS_TIME))

			return -EPERM;

		/*

		 * if the quartz is off by more than 10% then

		 * something is VERY wrong!

		 */

		if (txc->modes & ADJ_TICK &&

		    (txc->tick <  900000/USER_HZ ||

		     txc->tick > 1100000/USER_HZ))

			return -EINVAL;

	}



	if (txc->modes & ADJ_SETOFFSET) {

		/* In order to inject time, you gotta be super-user! */

		if (!capable(CAP_SYS_TIME))

			return -EPERM;



		if (txc->modes & ADJ_NANO) {

			struct timespec ts;



			ts.tv_sec = txc->time.tv_sec;

			ts.tv_nsec = txc->time.tv_usec;

			if (!timespec_inject_offset_valid(&ts))

				return -EINVAL;



		} else {

			if (!timeval_inject_offset_valid(&txc->time))

				return -EINVAL;

		}

	}



	/*

	 * Check for potential multiplication overflows that can

	 * only happen on 64-bit systems:

	 */

	if ((txc->modes & ADJ_FREQUENCY) && (BITS_PER_LONG == 64)) {

		if (LLONG_MIN / PPM_SCALE > txc->freq)

			return -EINVAL;

		if (LLONG_MAX / PPM_SCALE < txc->freq)

			return -EINVAL;

	}



	return 0;

}





/**

 * do_adjtimex() - Accessor function to NTP __do_adjtimex function

 */

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