[linux.git] / kernel / itimer.c

/*
 * linux/kernel/itimer.c
 *
 * Copyright (C) 1992 Darren Senn
 */

/* These are all the functions necessary to implement itimers */

#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/syscalls.h>
#include <linux/time.h>
#include <linux/posix-timers.h>
#include <linux/hrtimer.h>

#include <asm/uaccess.h>

/**
 * itimer_get_remtime - get remaining time for the timer
 *
 * @timer: the timer to read
 *
 * Returns the delta between the expiry time and now, which can be
 * less than zero or 1usec for an pending expired timer
 */
static struct timeval itimer_get_remtime(struct hrtimer *timer)
{
	ktime_t rem = hrtimer_get_remaining(timer);

	/*
	 * Racy but safe: if the itimer expires after the above
	 * hrtimer_get_remtime() call but before this condition
	 * then we return 0 - which is correct.
	 */
	if (hrtimer_active(timer)) {
		if (rem.tv64 <= 0)
			rem.tv64 = NSEC_PER_USEC;
	} else
		rem.tv64 = 0;

	return ktime_to_timeval(rem);
}

int do_getitimer(int which, struct itimerval *value)
{
	struct task_struct *tsk = current;
	cputime_t cinterval, cval;

	switch (which) {
	case ITIMER_REAL:
		spin_lock_irq(&tsk->sighand->siglock);
		value->it_value = itimer_get_remtime(&tsk->signal->real_timer);
		value->it_interval =
			ktime_to_timeval(tsk->signal->it_real_incr);
		spin_unlock_irq(&tsk->sighand->siglock);
		break;
	case ITIMER_VIRTUAL:
		read_lock(&tasklist_lock);
		spin_lock_irq(&tsk->sighand->siglock);
		cval = tsk->signal->it_virt_expires;
		cinterval = tsk->signal->it_virt_incr;
		if (!cputime_eq(cval, cputime_zero)) {
			struct task_struct *t = tsk;
			cputime_t utime = tsk->signal->utime;
			do {
				utime = cputime_add(utime, t->utime);
				t = next_thread(t);
			} while (t != tsk);
			if (cputime_le(cval, utime)) { /* about to fire */
				cval = jiffies_to_cputime(1);
			} else {
				cval = cputime_sub(cval, utime);
			}
		}
		spin_unlock_irq(&tsk->sighand->siglock);
		read_unlock(&tasklist_lock);
		cputime_to_timeval(cval, &value->it_value);
		cputime_to_timeval(cinterval, &value->it_interval);
		break;
	case ITIMER_PROF:
		read_lock(&tasklist_lock);
		spin_lock_irq(&tsk->sighand->siglock);
		cval = tsk->signal->it_prof_expires;
		cinterval = tsk->signal->it_prof_incr;
		if (!cputime_eq(cval, cputime_zero)) {
			struct task_struct *t = tsk;
			cputime_t ptime = cputime_add(tsk->signal->utime,
						      tsk->signal->stime);
			do {
				ptime = cputime_add(ptime,
						    cputime_add(t->utime,
								t->stime));
				t = next_thread(t);
			} while (t != tsk);
			if (cputime_le(cval, ptime)) { /* about to fire */
				cval = jiffies_to_cputime(1);
			} else {
				cval = cputime_sub(cval, ptime);
			}
		}
		spin_unlock_irq(&tsk->sighand->siglock);
		read_unlock(&tasklist_lock);
		cputime_to_timeval(cval, &value->it_value);
		cputime_to_timeval(cinterval, &value->it_interval);
		break;
	default:
		return(-EINVAL);
	}
	return 0;
}

asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
{
	int error = -EFAULT;
	struct itimerval get_buffer;

	if (value) {
		error = do_getitimer(which, &get_buffer);
		if (!error &&
		    copy_to_user(value, &get_buffer, sizeof(get_buffer)))
			error = -EFAULT;
	}
	return error;
}


/*
 * The timer is automagically restarted, when interval != 0
 */
int it_real_fn(void *data)
{
	struct task_struct *tsk = (struct task_struct *) data;

	send_group_sig_info(SIGALRM, SEND_SIG_PRIV, tsk);

	if (tsk->signal->it_real_incr.tv64 != 0) {
		hrtimer_forward(&tsk->signal->real_timer,
			       tsk->signal->it_real_incr);

		return HRTIMER_RESTART;
	}
	return HRTIMER_NORESTART;
}

int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
{
	struct task_struct *tsk = current;
	struct hrtimer *timer;
	ktime_t expires;
	cputime_t cval, cinterval, nval, ninterval;

	switch (which) {
	case ITIMER_REAL:
again:
		spin_lock_irq(&tsk->sighand->siglock);
		timer = &tsk->signal->real_timer;
		/* We are sharing ->siglock with it_real_fn() */
		if (hrtimer_try_to_cancel(timer) < 0) {
			spin_unlock_irq(&tsk->sighand->siglock);
			goto again;
		}
		if (ovalue) {
			ovalue->it_value = itimer_get_remtime(timer);
			ovalue->it_interval
				= ktime_to_timeval(tsk->signal->it_real_incr);
		}
		tsk->signal->it_real_incr =
			timeval_to_ktime(value->it_interval);
		expires = timeval_to_ktime(value->it_value);
		if (expires.tv64 != 0)
			hrtimer_start(timer, expires, HRTIMER_REL);
		spin_unlock_irq(&tsk->sighand->siglock);
		break;
	case ITIMER_VIRTUAL:
		nval = timeval_to_cputime(&value->it_value);
		ninterval = timeval_to_cputime(&value->it_interval);
		read_lock(&tasklist_lock);
		spin_lock_irq(&tsk->sighand->siglock);
		cval = tsk->signal->it_virt_expires;
		cinterval = tsk->signal->it_virt_incr;
		if (!cputime_eq(cval, cputime_zero) ||
		    !cputime_eq(nval, cputime_zero)) {
			if (cputime_gt(nval, cputime_zero))
				nval = cputime_add(nval,
						   jiffies_to_cputime(1));
			set_process_cpu_timer(tsk, CPUCLOCK_VIRT,
					      &nval, &cval);
		}
		tsk->signal->it_virt_expires = nval;
		tsk->signal->it_virt_incr = ninterval;
		spin_unlock_irq(&tsk->sighand->siglock);
		read_unlock(&tasklist_lock);
		if (ovalue) {
			cputime_to_timeval(cval, &ovalue->it_value);
			cputime_to_timeval(cinterval, &ovalue->it_interval);
		}
		break;
	case ITIMER_PROF:
		nval = timeval_to_cputime(&value->it_value);
		ninterval = timeval_to_cputime(&value->it_interval);
		read_lock(&tasklist_lock);
		spin_lock_irq(&tsk->sighand->siglock);
		cval = tsk->signal->it_prof_expires;
		cinterval = tsk->signal->it_prof_incr;
		if (!cputime_eq(cval, cputime_zero) ||
		    !cputime_eq(nval, cputime_zero)) {
			if (cputime_gt(nval, cputime_zero))
				nval = cputime_add(nval,
						   jiffies_to_cputime(1));
			set_process_cpu_timer(tsk, CPUCLOCK_PROF,
					      &nval, &cval);
		}
		tsk->signal->it_prof_expires = nval;
		tsk->signal->it_prof_incr = ninterval;
		spin_unlock_irq(&tsk->sighand->siglock);
		read_unlock(&tasklist_lock);
		if (ovalue) {
			cputime_to_timeval(cval, &ovalue->it_value);
			cputime_to_timeval(cinterval, &ovalue->it_interval);
		}
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

asmlinkage long sys_setitimer(int which,
			      struct itimerval __user *value,
			      struct itimerval __user *ovalue)
{
	struct itimerval set_buffer, get_buffer;
	int error;

	if (value) {
		if(copy_from_user(&set_buffer, value, sizeof(set_buffer)))
			return -EFAULT;
	} else
		memset((char *) &set_buffer, 0, sizeof(set_buffer));

	error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL);
	if (error || !ovalue)
		return error;

	if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))
		return -EFAULT; 
	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/kernel/itimer.c
	3	*
	4	* Copyright (C) 1992 Darren Senn
	5	*/
	6
	7	/* These are all the functions necessary to implement itimers */
	8
	9	#include <linux/mm.h>
	10	#include <linux/smp_lock.h>
	11	#include <linux/interrupt.h>
	12	#include <linux/syscalls.h>
	13	#include <linux/time.h>
	14	#include <linux/posix-timers.h>
2ff678b8	15	#include <linux/hrtimer.h>
1da177e4 LT	16
	17	#include <asm/uaccess.h>
	18
2ff678b8 TG	19	/**
	20	* itimer_get_remtime - get remaining time for the timer
	21	*
	22	* @timer: the timer to read
	23	*
	24	* Returns the delta between the expiry time and now, which can be
	25	* less than zero or 1usec for an pending expired timer
	26	*/
	27	static struct timeval itimer_get_remtime(struct hrtimer *timer)
1da177e4	28	{
2ff678b8	29	ktime_t rem = hrtimer_get_remaining(timer);
1da177e4	30
2ff678b8 TG	31	/*
	32	* Racy but safe: if the itimer expires after the above
	33	* hrtimer_get_remtime() call but before this condition
	34	* then we return 0 - which is correct.
	35	*/
	36	if (hrtimer_active(timer)) {
	37	if (rem.tv64 <= 0)
	38	rem.tv64 = NSEC_PER_USEC;
	39	} else
	40	rem.tv64 = 0;
	41
	42	return ktime_to_timeval(rem);
1da177e4 LT	43	}
	44
	45	int do_getitimer(int which, struct itimerval *value)
	46	{
	47	struct task_struct *tsk = current;
1da177e4 LT	48	cputime_t cinterval, cval;
	49
	50	switch (which) {
	51	case ITIMER_REAL:
bc1978d4	52	spin_lock_irq(&tsk->sighand->siglock);
2ff678b8 TG	53	value->it_value = itimer_get_remtime(&tsk->signal->real_timer);
	54	value->it_interval =
	55	ktime_to_timeval(tsk->signal->it_real_incr);
bc1978d4	56	spin_unlock_irq(&tsk->sighand->siglock);
1da177e4 LT	57	break;
	58	case ITIMER_VIRTUAL:
	59	read_lock(&tasklist_lock);
	60	spin_lock_irq(&tsk->sighand->siglock);
	61	cval = tsk->signal->it_virt_expires;
	62	cinterval = tsk->signal->it_virt_incr;
	63	if (!cputime_eq(cval, cputime_zero)) {
	64	struct task_struct *t = tsk;
	65	cputime_t utime = tsk->signal->utime;
	66	do {
	67	utime = cputime_add(utime, t->utime);
	68	t = next_thread(t);
	69	} while (t != tsk);
	70	if (cputime_le(cval, utime)) { /* about to fire */
	71	cval = jiffies_to_cputime(1);
	72	} else {
	73	cval = cputime_sub(cval, utime);
	74	}
	75	}
	76	spin_unlock_irq(&tsk->sighand->siglock);
	77	read_unlock(&tasklist_lock);
	78	cputime_to_timeval(cval, &value->it_value);
	79	cputime_to_timeval(cinterval, &value->it_interval);
	80	break;
	81	case ITIMER_PROF:
	82	read_lock(&tasklist_lock);
	83	spin_lock_irq(&tsk->sighand->siglock);
	84	cval = tsk->signal->it_prof_expires;
	85	cinterval = tsk->signal->it_prof_incr;
	86	if (!cputime_eq(cval, cputime_zero)) {
	87	struct task_struct *t = tsk;
	88	cputime_t ptime = cputime_add(tsk->signal->utime,
	89	tsk->signal->stime);
	90	do {
	91	ptime = cputime_add(ptime,
	92	cputime_add(t->utime,
	93	t->stime));
	94	t = next_thread(t);
	95	} while (t != tsk);
	96	if (cputime_le(cval, ptime)) { /* about to fire */
	97	cval = jiffies_to_cputime(1);
	98	} else {
	99	cval = cputime_sub(cval, ptime);
	100	}
	101	}
	102	spin_unlock_irq(&tsk->sighand->siglock);
	103	read_unlock(&tasklist_lock);
	104	cputime_to_timeval(cval, &value->it_value);
	105	cputime_to_timeval(cinterval, &value->it_interval);
	106	break;
	107	default:
	108	return(-EINVAL);
	109	}
	110	return 0;
	111	}
	112
	113	asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
	114	{
	115	int error = -EFAULT;
	116	struct itimerval get_buffer;
	117
	118	if (value) {
	119	error = do_getitimer(which, &get_buffer);
	120	if (!error &&
121	copy_to_user(value, &get_buffer, sizeof(get_buffer)))
122	error = -EFAULT;
123	}
124	return error;
125	}
126
1da177e4	127
2ff678b8 TG	128	/*
	129	* The timer is automagically restarted, when interval != 0
	130	*/
	131	int it_real_fn(void *data)
1da177e4	132	{
2ff678b8	133	struct task_struct tsk = (struct task_struct ) data;
1da177e4	134
2ff678b8	135	send_group_sig_info(SIGALRM, SEND_SIG_PRIV, tsk);
1da177e4	136
2ff678b8 TG	137	if (tsk->signal->it_real_incr.tv64 != 0) {
	138	hrtimer_forward(&tsk->signal->real_timer,
	139	tsk->signal->it_real_incr);
	140
	141	return HRTIMER_RESTART;
	142	}
	143	return HRTIMER_NORESTART;
1da177e4 LT	144	}
	145
	146	int do_setitimer(int which, struct itimerval value, struct itimerval ovalue)
	147	{
	148	struct task_struct *tsk = current;
2ff678b8 TG	149	struct hrtimer *timer;
2ff678b8 TG	150	ktime_t expires;
1da177e4 LT	151	cputime_t cval, cinterval, nval, ninterval;
	152
	153	switch (which) {
	154	case ITIMER_REAL:
bc1978d4 TG	155	again:
bc1978d4 TG	156	spin_lock_irq(&tsk->sighand->siglock);
2ff678b8	157	timer = &tsk->signal->real_timer;
bc1978d4 TG	158	/* We are sharing ->siglock with it_real_fn() */
	159	if (hrtimer_try_to_cancel(timer) < 0) {
	160	spin_unlock_irq(&tsk->sighand->siglock);
	161	goto again;
	162	}
1da177e4	163	if (ovalue) {
2ff678b8 TG	164	ovalue->it_value = itimer_get_remtime(timer);
	165	ovalue->it_interval
	166	= ktime_to_timeval(tsk->signal->it_real_incr);
1da177e4	167	}
2ff678b8 TG	168	tsk->signal->it_real_incr =
	169	timeval_to_ktime(value->it_interval);
	170	expires = timeval_to_ktime(value->it_value);
	171	if (expires.tv64 != 0)
	172	hrtimer_start(timer, expires, HRTIMER_REL);
bc1978d4	173	spin_unlock_irq(&tsk->sighand->siglock);
1da177e4 LT	174	break;
	175	case ITIMER_VIRTUAL:
	176	nval = timeval_to_cputime(&value->it_value);
	177	ninterval = timeval_to_cputime(&value->it_interval);
	178	read_lock(&tasklist_lock);
	179	spin_lock_irq(&tsk->sighand->siglock);
	180	cval = tsk->signal->it_virt_expires;
	181	cinterval = tsk->signal->it_virt_incr;
	182	if (!cputime_eq(cval, cputime_zero) \|\|
	183	!cputime_eq(nval, cputime_zero)) {
	184	if (cputime_gt(nval, cputime_zero))
	185	nval = cputime_add(nval,
	186	jiffies_to_cputime(1));
	187	set_process_cpu_timer(tsk, CPUCLOCK_VIRT,
	188	&nval, &cval);
	189	}
	190	tsk->signal->it_virt_expires = nval;
	191	tsk->signal->it_virt_incr = ninterval;
	192	spin_unlock_irq(&tsk->sighand->siglock);
	193	read_unlock(&tasklist_lock);
	194	if (ovalue) {
	195	cputime_to_timeval(cval, &ovalue->it_value);
	196	cputime_to_timeval(cinterval, &ovalue->it_interval);
	197	}
	198	break;
	199	case ITIMER_PROF:
	200	nval = timeval_to_cputime(&value->it_value);
	201	ninterval = timeval_to_cputime(&value->it_interval);
	202	read_lock(&tasklist_lock);
	203	spin_lock_irq(&tsk->sighand->siglock);
	204	cval = tsk->signal->it_prof_expires;
	205	cinterval = tsk->signal->it_prof_incr;
	206	if (!cputime_eq(cval, cputime_zero) \|\|
	207	!cputime_eq(nval, cputime_zero)) {
	208	if (cputime_gt(nval, cputime_zero))
	209	nval = cputime_add(nval,
	210	jiffies_to_cputime(1));
	211	set_process_cpu_timer(tsk, CPUCLOCK_PROF,
	212	&nval, &cval);
	213	}
	214	tsk->signal->it_prof_expires = nval;
	215	tsk->signal->it_prof_incr = ninterval;
	216	spin_unlock_irq(&tsk->sighand->siglock);
	217	read_unlock(&tasklist_lock);
	218	if (ovalue) {
	219	cputime_to_timeval(cval, &ovalue->it_value);
	220	cputime_to_timeval(cinterval, &ovalue->it_interval);
	221	}
	222	break;
	223	default:
	224	return -EINVAL;
	225	}
	226	return 0;
	227	}
	228
	229	asmlinkage long sys_setitimer(int which,
	230	struct itimerval __user *value,
	231	struct itimerval __user *ovalue)
	232	{
	233	struct itimerval set_buffer, get_buffer;
	234	int error;
	235
	236	if (value) {
	237	if(copy_from_user(&set_buffer, value, sizeof(set_buffer)))
238	return -EFAULT;
239	} else
240	memset((char *) &set_buffer, 0, sizeof(set_buffer));
241
242	error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL);
243	if (error \|\| !ovalue)
244	return error;
245
246	if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))
247	return -EFAULT;
248	return 0;
249	}