[deliverable/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:
		value->it_value = itimer_get_remtime(&tsk->signal->real_timer);
		value->it_interval =
			ktime_to_timeval(tsk->signal->it_real_incr);
		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:
		timer = &tsk->signal->real_timer;
		hrtimer_cancel(timer);
		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);
		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:
2ff678b8 TG	52	value->it_value = itimer_get_remtime(&tsk->signal->real_timer);
	53	value->it_interval =
	54	ktime_to_timeval(tsk->signal->it_real_incr);
1da177e4 LT	55	break;
	56	case ITIMER_VIRTUAL:
	57	read_lock(&tasklist_lock);
	58	spin_lock_irq(&tsk->sighand->siglock);
	59	cval = tsk->signal->it_virt_expires;
	60	cinterval = tsk->signal->it_virt_incr;
	61	if (!cputime_eq(cval, cputime_zero)) {
	62	struct task_struct *t = tsk;
	63	cputime_t utime = tsk->signal->utime;
	64	do {
	65	utime = cputime_add(utime, t->utime);
	66	t = next_thread(t);
	67	} while (t != tsk);
	68	if (cputime_le(cval, utime)) { /* about to fire */
	69	cval = jiffies_to_cputime(1);
	70	} else {
	71	cval = cputime_sub(cval, utime);
	72	}
	73	}
	74	spin_unlock_irq(&tsk->sighand->siglock);
	75	read_unlock(&tasklist_lock);
	76	cputime_to_timeval(cval, &value->it_value);
	77	cputime_to_timeval(cinterval, &value->it_interval);
	78	break;
	79	case ITIMER_PROF:
	80	read_lock(&tasklist_lock);
	81	spin_lock_irq(&tsk->sighand->siglock);
	82	cval = tsk->signal->it_prof_expires;
	83	cinterval = tsk->signal->it_prof_incr;
	84	if (!cputime_eq(cval, cputime_zero)) {
	85	struct task_struct *t = tsk;
	86	cputime_t ptime = cputime_add(tsk->signal->utime,
	87	tsk->signal->stime);
	88	do {
	89	ptime = cputime_add(ptime,
	90	cputime_add(t->utime,
	91	t->stime));
	92	t = next_thread(t);
	93	} while (t != tsk);
	94	if (cputime_le(cval, ptime)) { /* about to fire */
	95	cval = jiffies_to_cputime(1);
	96	} else {
	97	cval = cputime_sub(cval, ptime);
	98	}
	99	}
	100	spin_unlock_irq(&tsk->sighand->siglock);
	101	read_unlock(&tasklist_lock);
	102	cputime_to_timeval(cval, &value->it_value);
	103	cputime_to_timeval(cinterval, &value->it_interval);
	104	break;
	105	default:
	106	return(-EINVAL);
	107	}
	108	return 0;
	109	}
	110
	111	asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
	112	{
	113	int error = -EFAULT;
	114	struct itimerval get_buffer;
	115
	116	if (value) {
	117	error = do_getitimer(which, &get_buffer);
	118	if (!error &&
119	copy_to_user(value, &get_buffer, sizeof(get_buffer)))
120	error = -EFAULT;
121	}
122	return error;
123	}
124
1da177e4	125
2ff678b8 TG	126	/*
	127	* The timer is automagically restarted, when interval != 0
	128	*/
	129	int it_real_fn(void *data)
1da177e4	130	{
2ff678b8	131	struct task_struct tsk = (struct task_struct ) data;
1da177e4	132
2ff678b8	133	send_group_sig_info(SIGALRM, SEND_SIG_PRIV, tsk);
1da177e4	134
2ff678b8 TG	135	if (tsk->signal->it_real_incr.tv64 != 0) {
	136	hrtimer_forward(&tsk->signal->real_timer,
	137	tsk->signal->it_real_incr);
	138
	139	return HRTIMER_RESTART;
	140	}
	141	return HRTIMER_NORESTART;
1da177e4 LT	142	}
	143
	144	int do_setitimer(int which, struct itimerval value, struct itimerval ovalue)
	145	{
	146	struct task_struct *tsk = current;
2ff678b8 TG	147	struct hrtimer *timer;
2ff678b8 TG	148	ktime_t expires;
1da177e4 LT	149	cputime_t cval, cinterval, nval, ninterval;
	150
	151	switch (which) {
	152	case ITIMER_REAL:
2ff678b8 TG	153	timer = &tsk->signal->real_timer;
2ff678b8 TG	154	hrtimer_cancel(timer);
1da177e4	155	if (ovalue) {
2ff678b8 TG	156	ovalue->it_value = itimer_get_remtime(timer);
	157	ovalue->it_interval
	158	= ktime_to_timeval(tsk->signal->it_real_incr);
1da177e4	159	}
2ff678b8 TG	160	tsk->signal->it_real_incr =
	161	timeval_to_ktime(value->it_interval);
	162	expires = timeval_to_ktime(value->it_value);
	163	if (expires.tv64 != 0)
	164	hrtimer_start(timer, expires, HRTIMER_REL);
1da177e4 LT	165	break;
	166	case ITIMER_VIRTUAL:
	167	nval = timeval_to_cputime(&value->it_value);
	168	ninterval = timeval_to_cputime(&value->it_interval);
	169	read_lock(&tasklist_lock);
	170	spin_lock_irq(&tsk->sighand->siglock);
	171	cval = tsk->signal->it_virt_expires;
	172	cinterval = tsk->signal->it_virt_incr;
	173	if (!cputime_eq(cval, cputime_zero) \|\|
	174	!cputime_eq(nval, cputime_zero)) {
	175	if (cputime_gt(nval, cputime_zero))
	176	nval = cputime_add(nval,
	177	jiffies_to_cputime(1));
	178	set_process_cpu_timer(tsk, CPUCLOCK_VIRT,
	179	&nval, &cval);
	180	}
	181	tsk->signal->it_virt_expires = nval;
	182	tsk->signal->it_virt_incr = ninterval;
	183	spin_unlock_irq(&tsk->sighand->siglock);
	184	read_unlock(&tasklist_lock);
	185	if (ovalue) {
	186	cputime_to_timeval(cval, &ovalue->it_value);
	187	cputime_to_timeval(cinterval, &ovalue->it_interval);
	188	}
	189	break;
	190	case ITIMER_PROF:
	191	nval = timeval_to_cputime(&value->it_value);
	192	ninterval = timeval_to_cputime(&value->it_interval);
	193	read_lock(&tasklist_lock);
	194	spin_lock_irq(&tsk->sighand->siglock);
	195	cval = tsk->signal->it_prof_expires;
	196	cinterval = tsk->signal->it_prof_incr;
	197	if (!cputime_eq(cval, cputime_zero) \|\|
	198	!cputime_eq(nval, cputime_zero)) {
	199	if (cputime_gt(nval, cputime_zero))
	200	nval = cputime_add(nval,
	201	jiffies_to_cputime(1));
	202	set_process_cpu_timer(tsk, CPUCLOCK_PROF,
	203	&nval, &cval);
	204	}
	205	tsk->signal->it_prof_expires = nval;
	206	tsk->signal->it_prof_incr = ninterval;
	207	spin_unlock_irq(&tsk->sighand->siglock);
	208	read_unlock(&tasklist_lock);
	209	if (ovalue) {
	210	cputime_to_timeval(cval, &ovalue->it_value);
	211	cputime_to_timeval(cinterval, &ovalue->it_interval);
	212	}
	213	break;
	214	default:
	215	return -EINVAL;
	216	}
	217	return 0;
	218	}
	219
	220	asmlinkage long sys_setitimer(int which,
	221	struct itimerval __user *value,
	222	struct itimerval __user *ovalue)
	223	{
	224	struct itimerval set_buffer, get_buffer;
	225	int error;
	226
	227	if (value) {
	228	if(copy_from_user(&set_buffer, value, sizeof(set_buffer)))
229	return -EFAULT;
230	} else
231	memset((char *) &set_buffer, 0, sizeof(set_buffer));
232
233	error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL);
234	if (error \|\| !ovalue)
235	return error;
236
237	if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))
238	return -EFAULT;
239	return 0;
240	}