Commit 7e55b6ba authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

timekeeping: Avoid double notification in do_adjtimex() 



Consolidate do_adjtimex() so that it does not notify about clock changes
twice.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250519083025.779267274@linutronix.de
parent 506a54a0

kernel/time/timekeeping.c

+56 −42
Original line number Diff line number Diff line
@@ -1418,19 +1418,19 @@ int do_settimeofday64(const struct timespec64 *ts) 
EXPORT_SYMBOL(do_settimeofday64);



/**

 * timekeeping_inject_offset - Adds or subtracts from the current time.

 * __timekeeping_inject_offset - Adds or subtracts from the current time.

 * @ts:		Pointer to the timespec variable containing the offset

 *

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

 */

static int timekeeping_inject_offset(const struct timespec64 *ts)

static int __timekeeping_inject_offset(const struct timespec64 *ts)

{

	struct timekeeper *tks = &tk_core.shadow_timekeeper;

	struct timespec64 tmp;



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

		return -EINVAL;



	scoped_guard (raw_spinlock_irqsave, &tk_core.lock) {

		struct timekeeper *tks = &tk_core.shadow_timekeeper;

		struct timespec64 tmp;



	timekeeping_forward_now(tks);
@@ -1445,11 +1445,20 @@ static int timekeeping_inject_offset(const struct timespec64 *ts) 
	tk_xtime_add(tks, ts);

	tk_set_wall_to_mono(tks, timespec64_sub(tks->wall_to_monotonic, *ts));

	timekeeping_update_from_shadow(&tk_core, TK_UPDATE_ALL);

	return 0;

}



static int timekeeping_inject_offset(const struct timespec64 *ts)

{

	int ret;



	scoped_guard (raw_spinlock_irqsave, &tk_core.lock)

		ret = __timekeeping_inject_offset(ts);



	/* Signal hrtimers about time change */

	if (!ret)

		clock_was_set(CLOCK_SET_WALL);

	return 0;

	return ret;

}



/*
@@ -2186,7 +2195,7 @@ static u64 logarithmic_accumulation(struct timekeeper *tk, u64 offset, 
 * timekeeping_advance - Updates the timekeeper to the current time and

 * current NTP tick length

 */

static bool timekeeping_advance(enum timekeeping_adv_mode mode)

static bool __timekeeping_advance(enum timekeeping_adv_mode mode)

{

	struct timekeeper *tk = &tk_core.shadow_timekeeper;

	struct timekeeper *real_tk = &tk_core.timekeeper;
@@ -2194,8 +2203,6 @@ static bool timekeeping_advance(enum timekeeping_adv_mode mode) 
	int shift = 0, maxshift;

	u64 offset, orig_offset;



	guard(raw_spinlock_irqsave)(&tk_core.lock);



	/* Make sure we're fully resumed: */

	if (unlikely(timekeeping_suspended))

		return false;
@@ -2249,6 +2256,12 @@ static bool timekeeping_advance(enum timekeeping_adv_mode mode) 
	return !!clock_set;

}



static bool timekeeping_advance(enum timekeeping_adv_mode mode)

{

	guard(raw_spinlock_irqsave)(&tk_core.lock);

	return __timekeeping_advance(mode);

}



/**

 * update_wall_time - Uses the current clocksource to increment the wall time

 *
@@ -2537,10 +2550,10 @@ EXPORT_SYMBOL_GPL(random_get_entropy_fallback); 
 */

int do_adjtimex(struct __kernel_timex *txc)

{

	struct timespec64 delta, ts;

	struct audit_ntp_data ad;

	bool offset_set = false;

	bool clock_set = false;

	struct timespec64 ts;

	int ret;



	/* Validate the data before disabling interrupts */
@@ -2549,30 +2562,28 @@ int do_adjtimex(struct __kernel_timex *txc) 
		return ret;

	add_device_randomness(txc, sizeof(*txc));



	if (txc->modes & ADJ_SETOFFSET) {

		struct timespec64 delta;

	audit_ntp_init(&ad);



	ktime_get_real_ts64(&ts);

	add_device_randomness(&ts, sizeof(ts));



	scoped_guard (raw_spinlock_irqsave, &tk_core.lock) {

		struct timekeeper *tks = &tk_core.shadow_timekeeper;

		s32 orig_tai, tai;



		if (txc->modes & ADJ_SETOFFSET) {

			delta.tv_sec  = txc->time.tv_sec;

			delta.tv_nsec = txc->time.tv_usec;

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

				delta.tv_nsec *= 1000;

		ret = timekeeping_inject_offset(&delta);

			ret = __timekeeping_inject_offset(&delta);

			if (ret)

				return ret;



			offset_set = delta.tv_sec != 0;

		audit_tk_injoffset(delta);

			clock_set = true;

		}



	audit_ntp_init(&ad);



	ktime_get_real_ts64(&ts);

	add_device_randomness(&ts, sizeof(ts));



	scoped_guard (raw_spinlock_irqsave, &tk_core.lock) {

		struct timekeeper *tks = &tk_core.shadow_timekeeper;

		s32 orig_tai, tai;



		orig_tai = tai = tks->tai_offset;

		ret = __do_adjtimex(txc, &ts, &tai, &ad);
@@ -2583,13 +2594,16 @@ int do_adjtimex(struct __kernel_timex *txc) 
		} else {

			tk_update_leap_state_all(&tk_core);

		}

	}



	audit_ntp_log(&ad);



		/* Update the multiplier immediately if frequency was set directly */

		if (txc->modes & (ADJ_FREQUENCY | ADJ_TICK))

		clock_set |= timekeeping_advance(TK_ADV_FREQ);

			clock_set |= __timekeeping_advance(TK_ADV_FREQ);

	}



	if (txc->modes & ADJ_SETOFFSET)

		audit_tk_injoffset(delta);



	audit_ntp_log(&ad);



	if (clock_set)

		clock_was_set(CLOCK_SET_WALL);