[linux-2.6-block.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/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
 */
enum hrtimer_restart it_real_fn(struct hrtimer *timer)
{
	struct signal_struct *sig =
	    container_of(timer, struct signal_struct, real_timer);

	send_group_sig_info(SIGALRM, SEND_SIG_PRIV, sig->tsk);

	return HRTIMER_NORESTART;
}

/*
 * We do not care about correctness. We just sanitize the values so
 * the ktime_t operations which expect normalized values do not
 * break. This converts negative values to long timeouts similar to
 * the code in kernel versions < 2.6.16
 *
 * Print a limited number of warning messages when an invalid timeval
 * is detected.
 */
static void fixup_timeval(struct timeval *tv, int interval)
{
	static int warnlimit = 10;
	unsigned long tmp;

	if (warnlimit > 0) {
		warnlimit--;
		printk(KERN_WARNING
		       "setitimer: %s (pid = %d) provided "
		       "invalid timeval %s: tv_sec = %ld tv_usec = %ld\n",
		       current->comm, current->pid,
		       interval ? "it_interval" : "it_value",
		       tv->tv_sec, (long) tv->tv_usec);
	}

	tmp = tv->tv_usec;
	if (tmp >= USEC_PER_SEC) {
		tv->tv_usec = tmp % USEC_PER_SEC;
		tv->tv_sec += tmp / USEC_PER_SEC;
	}

	tmp = tv->tv_sec;
	if (tmp > LONG_MAX)
		tv->tv_sec = LONG_MAX;
}

/*
 * Returns true if the timeval is in canonical form
 */
#define timeval_valid(t) \
	(((t)->tv_sec >= 0) && (((unsigned long) (t)->tv_usec) < USEC_PER_SEC))

/*
 * Check for invalid timevals, sanitize them and print a limited
 * number of warnings.
 */
static void check_itimerval(struct itimerval *value) {

	if (unlikely(!timeval_valid(&value->it_value)))
		fixup_timeval(&value->it_value, 0);

	if (unlikely(!timeval_valid(&value->it_interval)))
		fixup_timeval(&value->it_interval, 1);
}

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;

	/*
	 * Validate the timevals in value.
	 *
	 * Note: Although the spec requires that invalid values shall
	 * return -EINVAL, we just fixup the value and print a limited
	 * number of warnings in order not to break users of this
	 * historical misfeature.
	 *
	 * Scheduled for replacement in March 2007
	 */
	check_itimerval(value);

	switch (which) {
	case ITIMER_REAL:
again:
		spin_lock_irq(&tsk->sighand->siglock);
		timer = &tsk->signal->real_timer;
		if (ovalue) {
			ovalue->it_value = itimer_get_remtime(timer);
			ovalue->it_interval
				= ktime_to_timeval(tsk->signal->it_real_incr);
		}
		/* We are sharing ->siglock with it_real_fn() */
		if (hrtimer_try_to_cancel(timer) < 0) {
			spin_unlock_irq(&tsk->sighand->siglock);
			goto again;
		}
		expires = timeval_to_ktime(value->it_value);
		if (expires.tv64 != 0) {
			tsk->signal->it_real_incr =
				timeval_to_ktime(value->it_interval);
			hrtimer_start(timer, expires, HRTIMER_MODE_REL);
		} else
			tsk->signal->it_real_incr.tv64 = 0;

		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;
}

/**
 * alarm_setitimer - set alarm in seconds
 *
 * @seconds:	number of seconds until alarm
 *		0 disables the alarm
 *
 * Returns the remaining time in seconds of a pending timer or 0 when
 * the timer is not active.
 *
 * On 32 bit machines the seconds value is limited to (INT_MAX/2) to avoid
 * negative timeval settings which would cause immediate expiry.
 */
unsigned int alarm_setitimer(unsigned int seconds)
{
	struct itimerval it_new, it_old;

#if BITS_PER_LONG < 64
	if (seconds > INT_MAX)
		seconds = INT_MAX;
#endif
	it_new.it_value.tv_sec = seconds;
	it_new.it_value.tv_usec = 0;
	it_new.it_interval.tv_sec = it_new.it_interval.tv_usec = 0;

	do_setitimer(ITIMER_REAL, &it_new, &it_old);

	/*
	 * We can't return 0 if we have an alarm pending ...  And we'd
	 * better return too much than too little anyway
	 */
	if ((!it_old.it_value.tv_sec && it_old.it_value.tv_usec) ||
	      it_old.it_value.tv_usec >= 500000)
		it_old.it_value.tv_sec++;

	return it_old.it_value.tv_sec;
}

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>
1da177e4 LT	10	#include <linux/interrupt.h>
	11	#include <linux/syscalls.h>
	12	#include <linux/time.h>
	13	#include <linux/posix-timers.h>
2ff678b8	14	#include <linux/hrtimer.h>
1da177e4 LT	15
	16	#include <asm/uaccess.h>
	17
2ff678b8 TG	18	/**
	19	* itimer_get_remtime - get remaining time for the timer
	20	*
	21	* @timer: the timer to read
	22	*
	23	* Returns the delta between the expiry time and now, which can be
	24	* less than zero or 1usec for an pending expired timer
	25	*/
	26	static struct timeval itimer_get_remtime(struct hrtimer *timer)
1da177e4	27	{
2ff678b8	28	ktime_t rem = hrtimer_get_remaining(timer);
1da177e4	29
2ff678b8 TG	30	/*
	31	* Racy but safe: if the itimer expires after the above
	32	* hrtimer_get_remtime() call but before this condition
	33	* then we return 0 - which is correct.
	34	*/
	35	if (hrtimer_active(timer)) {
	36	if (rem.tv64 <= 0)
	37	rem.tv64 = NSEC_PER_USEC;
	38	} else
	39	rem.tv64 = 0;
	40
	41	return ktime_to_timeval(rem);
1da177e4 LT	42	}
	43
	44	int do_getitimer(int which, struct itimerval *value)
	45	{
	46	struct task_struct *tsk = current;
1da177e4 LT	47	cputime_t cinterval, cval;
	48
	49	switch (which) {
	50	case ITIMER_REAL:
bc1978d4	51	spin_lock_irq(&tsk->sighand->siglock);
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);
bc1978d4	55	spin_unlock_irq(&tsk->sighand->siglock);
1da177e4 LT	56	break;
	57	case ITIMER_VIRTUAL:
	58	read_lock(&tasklist_lock);
	59	spin_lock_irq(&tsk->sighand->siglock);
	60	cval = tsk->signal->it_virt_expires;
	61	cinterval = tsk->signal->it_virt_incr;
	62	if (!cputime_eq(cval, cputime_zero)) {
	63	struct task_struct *t = tsk;
	64	cputime_t utime = tsk->signal->utime;
	65	do {
	66	utime = cputime_add(utime, t->utime);
	67	t = next_thread(t);
	68	} while (t != tsk);
	69	if (cputime_le(cval, utime)) { /* about to fire */
	70	cval = jiffies_to_cputime(1);
	71	} else {
	72	cval = cputime_sub(cval, utime);
	73	}
	74	}
	75	spin_unlock_irq(&tsk->sighand->siglock);
	76	read_unlock(&tasklist_lock);
	77	cputime_to_timeval(cval, &value->it_value);
	78	cputime_to_timeval(cinterval, &value->it_interval);
	79	break;
	80	case ITIMER_PROF:
	81	read_lock(&tasklist_lock);
	82	spin_lock_irq(&tsk->sighand->siglock);
	83	cval = tsk->signal->it_prof_expires;
	84	cinterval = tsk->signal->it_prof_incr;
	85	if (!cputime_eq(cval, cputime_zero)) {
	86	struct task_struct *t = tsk;
	87	cputime_t ptime = cputime_add(tsk->signal->utime,
	88	tsk->signal->stime);
	89	do {
	90	ptime = cputime_add(ptime,
	91	cputime_add(t->utime,
	92	t->stime));
	93	t = next_thread(t);
	94	} while (t != tsk);
	95	if (cputime_le(cval, ptime)) { /* about to fire */
	96	cval = jiffies_to_cputime(1);
	97	} else {
	98	cval = cputime_sub(cval, ptime);
	99	}
	100	}
	101	spin_unlock_irq(&tsk->sighand->siglock);
	102	read_unlock(&tasklist_lock);
	103	cputime_to_timeval(cval, &value->it_value);
	104	cputime_to_timeval(cinterval, &value->it_interval);
	105	break;
	106	default:
	107	return(-EINVAL);
	108	}
	109	return 0;
	110	}
	111
	112	asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
	113	{
	114	int error = -EFAULT;
	115	struct itimerval get_buffer;
	116
	117	if (value) {
	118	error = do_getitimer(which, &get_buffer);
	119	if (!error &&
120	copy_to_user(value, &get_buffer, sizeof(get_buffer)))
121	error = -EFAULT;
122	}
123	return error;
124	}
125
1da177e4	126
2ff678b8 TG	127	/*
	128	* The timer is automagically restarted, when interval != 0
	129	*/
c9cb2e3d	130	enum hrtimer_restart it_real_fn(struct hrtimer *timer)
1da177e4	131	{
05cfb614 RZ	132	struct signal_struct *sig =
05cfb614 RZ	133	container_of(timer, struct signal_struct, real_timer);
1da177e4	134
05cfb614	135	send_group_sig_info(SIGALRM, SEND_SIG_PRIV, sig->tsk);
2ff678b8	136
2ff678b8	137	return HRTIMER_NORESTART;
1da177e4 LT	138	}
1da177e4 LT	139
7d99b7d6 TG	140	/*
	141	* We do not care about correctness. We just sanitize the values so
	142	* the ktime_t operations which expect normalized values do not
	143	* break. This converts negative values to long timeouts similar to
	144	* the code in kernel versions < 2.6.16
	145	*
	146	* Print a limited number of warning messages when an invalid timeval
	147	* is detected.
	148	*/
	149	static void fixup_timeval(struct timeval *tv, int interval)
	150	{
	151	static int warnlimit = 10;
	152	unsigned long tmp;
	153
	154	if (warnlimit > 0) {
	155	warnlimit--;
	156	printk(KERN_WARNING
	157	"setitimer: %s (pid = %d) provided "
	158	"invalid timeval %s: tv_sec = %ld tv_usec = %ld\n",
	159	current->comm, current->pid,
	160	interval ? "it_interval" : "it_value",
	161	tv->tv_sec, (long) tv->tv_usec);
	162	}
	163
	164	tmp = tv->tv_usec;
	165	if (tmp >= USEC_PER_SEC) {
	166	tv->tv_usec = tmp % USEC_PER_SEC;
	167	tv->tv_sec += tmp / USEC_PER_SEC;
	168	}
	169
	170	tmp = tv->tv_sec;
	171	if (tmp > LONG_MAX)
	172	tv->tv_sec = LONG_MAX;
	173	}
	174
	175	/*
	176	* Returns true if the timeval is in canonical form
	177	*/
	178	#define timeval_valid(t) \
	179	(((t)->tv_sec >= 0) && (((unsigned long) (t)->tv_usec) < USEC_PER_SEC))
	180
	181	/*
	182	* Check for invalid timevals, sanitize them and print a limited
	183	* number of warnings.
	184	*/
	185	static void check_itimerval(struct itimerval *value) {
	186
	187	if (unlikely(!timeval_valid(&value->it_value)))
	188	fixup_timeval(&value->it_value, 0);
	189
	190	if (unlikely(!timeval_valid(&value->it_interval)))
	191	fixup_timeval(&value->it_interval, 1);
	192	}
	193
1da177e4 LT	194	int do_setitimer(int which, struct itimerval value, struct itimerval ovalue)
	195	{
	196	struct task_struct *tsk = current;
2ff678b8 TG	197	struct hrtimer *timer;
2ff678b8 TG	198	ktime_t expires;
1da177e4 LT	199	cputime_t cval, cinterval, nval, ninterval;
1da177e4 LT	200
7d99b7d6 TG	201	/*
	202	* Validate the timevals in value.
	203	*
	204	* Note: Although the spec requires that invalid values shall
	205	* return -EINVAL, we just fixup the value and print a limited
	206	* number of warnings in order not to break users of this
	207	* historical misfeature.
	208	*
	209	* Scheduled for replacement in March 2007
	210	*/
	211	check_itimerval(value);
	212
1da177e4 LT	213	switch (which) {
1da177e4 LT	214	case ITIMER_REAL:
bc1978d4 TG	215	again:
bc1978d4 TG	216	spin_lock_irq(&tsk->sighand->siglock);
2ff678b8	217	timer = &tsk->signal->real_timer;
1da177e4	218	if (ovalue) {
2ff678b8 TG	219	ovalue->it_value = itimer_get_remtime(timer);
	220	ovalue->it_interval
	221	= ktime_to_timeval(tsk->signal->it_real_incr);
1da177e4	222	}
a16a1c09 TG	223	/* We are sharing ->siglock with it_real_fn() */
	224	if (hrtimer_try_to_cancel(timer) < 0) {
	225	spin_unlock_irq(&tsk->sighand->siglock);
	226	goto again;
	227	}
2ff678b8	228	expires = timeval_to_ktime(value->it_value);
8bfd9a7a TG	229	if (expires.tv64 != 0) {
	230	tsk->signal->it_real_incr =
	231	timeval_to_ktime(value->it_interval);
c9cb2e3d	232	hrtimer_start(timer, expires, HRTIMER_MODE_REL);
8bfd9a7a TG	233	} else
	234	tsk->signal->it_real_incr.tv64 = 0;
	235
bc1978d4	236	spin_unlock_irq(&tsk->sighand->siglock);
1da177e4 LT	237	break;
	238	case ITIMER_VIRTUAL:
	239	nval = timeval_to_cputime(&value->it_value);
	240	ninterval = timeval_to_cputime(&value->it_interval);
	241	read_lock(&tasklist_lock);
	242	spin_lock_irq(&tsk->sighand->siglock);
	243	cval = tsk->signal->it_virt_expires;
	244	cinterval = tsk->signal->it_virt_incr;
	245	if (!cputime_eq(cval, cputime_zero) \|\|
	246	!cputime_eq(nval, cputime_zero)) {
	247	if (cputime_gt(nval, cputime_zero))
	248	nval = cputime_add(nval,
	249	jiffies_to_cputime(1));
	250	set_process_cpu_timer(tsk, CPUCLOCK_VIRT,
	251	&nval, &cval);
	252	}
	253	tsk->signal->it_virt_expires = nval;
	254	tsk->signal->it_virt_incr = ninterval;
	255	spin_unlock_irq(&tsk->sighand->siglock);
	256	read_unlock(&tasklist_lock);
	257	if (ovalue) {
	258	cputime_to_timeval(cval, &ovalue->it_value);
	259	cputime_to_timeval(cinterval, &ovalue->it_interval);
	260	}
	261	break;
	262	case ITIMER_PROF:
	263	nval = timeval_to_cputime(&value->it_value);
	264	ninterval = timeval_to_cputime(&value->it_interval);
	265	read_lock(&tasklist_lock);
	266	spin_lock_irq(&tsk->sighand->siglock);
	267	cval = tsk->signal->it_prof_expires;
	268	cinterval = tsk->signal->it_prof_incr;
	269	if (!cputime_eq(cval, cputime_zero) \|\|
	270	!cputime_eq(nval, cputime_zero)) {
	271	if (cputime_gt(nval, cputime_zero))
	272	nval = cputime_add(nval,
	273	jiffies_to_cputime(1));
	274	set_process_cpu_timer(tsk, CPUCLOCK_PROF,
	275	&nval, &cval);
	276	}
	277	tsk->signal->it_prof_expires = nval;
	278	tsk->signal->it_prof_incr = ninterval;
	279	spin_unlock_irq(&tsk->sighand->siglock);
	280	read_unlock(&tasklist_lock);
	281	if (ovalue) {
	282	cputime_to_timeval(cval, &ovalue->it_value);
	283	cputime_to_timeval(cinterval, &ovalue->it_interval);
	284	}
	285	break;
	286	default:
	287	return -EINVAL;
	288	}
	289	return 0;
	290	}
	291
c08b8a49 TG	292	/**
	293	* alarm_setitimer - set alarm in seconds
	294	*
	295	* @seconds: number of seconds until alarm
	296	* 0 disables the alarm
	297	*
	298	* Returns the remaining time in seconds of a pending timer or 0 when
	299	* the timer is not active.
	300	*
	301	* On 32 bit machines the seconds value is limited to (INT_MAX/2) to avoid
	302	* negative timeval settings which would cause immediate expiry.
	303	*/
	304	unsigned int alarm_setitimer(unsigned int seconds)
	305	{
	306	struct itimerval it_new, it_old;
	307
	308	#if BITS_PER_LONG < 64
	309	if (seconds > INT_MAX)
	310	seconds = INT_MAX;
	311	#endif
	312	it_new.it_value.tv_sec = seconds;
	313	it_new.it_value.tv_usec = 0;
	314	it_new.it_interval.tv_sec = it_new.it_interval.tv_usec = 0;
	315
	316	do_setitimer(ITIMER_REAL, &it_new, &it_old);
	317
	318	/*
	319	* We can't return 0 if we have an alarm pending ... And we'd
	320	* better return too much than too little anyway
	321	*/
	322	if ((!it_old.it_value.tv_sec && it_old.it_value.tv_usec) \|\|
	323	it_old.it_value.tv_usec >= 500000)
	324	it_old.it_value.tv_sec++;
	325
	326	return it_old.it_value.tv_sec;
	327	}
	328
1da177e4 LT	329	asmlinkage long sys_setitimer(int which,
	330	struct itimerval __user *value,
	331	struct itimerval __user *ovalue)
	332	{
	333	struct itimerval set_buffer, get_buffer;
	334	int error;
	335
	336	if (value) {
	337	if(copy_from_user(&set_buffer, value, sizeof(set_buffer)))
	338	return -EFAULT;
	339	} else
	340	memset((char *) &set_buffer, 0, sizeof(set_buffer));
	341
	342	error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL);
	343	if (error \|\| !ovalue)
	344	return error;
	345
	346	if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))
	347	return -EFAULT;
	348	return 0;
	349	}