[net-next-2.6.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 <asm/uaccess.h>

static unsigned long it_real_value(struct signal_struct *sig)
{
	unsigned long val = 0;
	if (timer_pending(&sig->real_timer)) {
		val = sig->real_timer.expires - jiffies;

		/* look out for negative/zero itimer.. */
		if ((long) val <= 0)
			val = 1;
	}
	return val;
}

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

	switch (which) {
	case ITIMER_REAL:
		spin_lock_irq(&tsk->sighand->siglock);
		interval = tsk->signal->it_real_incr;
		val = it_real_value(tsk->signal);
		spin_unlock_irq(&tsk->sighand->siglock);
		jiffies_to_timeval(val, &value->it_value);
		jiffies_to_timeval(interval, &value->it_interval);
		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;
}


void it_real_fn(unsigned long __data)
{
	struct task_struct * p = (struct task_struct *) __data;
	unsigned long inc = p->signal->it_real_incr;

	send_group_sig_info(SIGALRM, SEND_SIG_PRIV, p);

	/*
	 * Now restart the timer if necessary.  We don't need any locking
	 * here because do_setitimer makes sure we have finished running
	 * before it touches anything.
	 * Note, we KNOW we are (or should be) at a jiffie edge here so
	 * we don't need the +1 stuff.  Also, we want to use the prior
	 * expire value so as to not "slip" a jiffie if we are late.
	 * Deal with requesting a time prior to "now" here rather than
	 * in add_timer.
	 */
	if (!inc)
		return;
	while (time_before_eq(p->signal->real_timer.expires, jiffies))
		p->signal->real_timer.expires += inc;
	add_timer(&p->signal->real_timer);
}

int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
{
	struct task_struct *tsk = current;
 	unsigned long val, interval, expires;
	cputime_t cval, cinterval, nval, ninterval;

	switch (which) {
	case ITIMER_REAL:
again:
		spin_lock_irq(&tsk->sighand->siglock);
		interval = tsk->signal->it_real_incr;
		val = it_real_value(tsk->signal);
		/* We are sharing ->siglock with it_real_fn() */
		if (try_to_del_timer_sync(&tsk->signal->real_timer) < 0) {
			spin_unlock_irq(&tsk->sighand->siglock);
			goto again;
		}
		tsk->signal->it_real_incr =
			timeval_to_jiffies(&value->it_interval);
		expires = timeval_to_jiffies(&value->it_value);
		if (expires)
			mod_timer(&tsk->signal->real_timer,
				  jiffies + 1 + expires);
		spin_unlock_irq(&tsk->sighand->siglock);
		if (ovalue) {
			jiffies_to_timeval(val, &ovalue->it_value);
			jiffies_to_timeval(interval,
					   &ovalue->it_interval);
		}
		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>
	15
	16	#include <asm/uaccess.h>
	17
	18	static unsigned long it_real_value(struct signal_struct *sig)
	19	{
	20	unsigned long val = 0;
	21	if (timer_pending(&sig->real_timer)) {
	22	val = sig->real_timer.expires - jiffies;
	23
	24	/* look out for negative/zero itimer.. */
	25	if ((long) val <= 0)
	26	val = 1;
	27	}
	28	return val;
	29	}
	30
	31	int do_getitimer(int which, struct itimerval *value)
	32	{
	33	struct task_struct *tsk = current;
	34	unsigned long interval, val;
	35	cputime_t cinterval, cval;
	36
	37	switch (which) {
	38	case ITIMER_REAL:
	39	spin_lock_irq(&tsk->sighand->siglock);
	40	interval = tsk->signal->it_real_incr;
	41	val = it_real_value(tsk->signal);
	42	spin_unlock_irq(&tsk->sighand->siglock);
	43	jiffies_to_timeval(val, &value->it_value);
	44	jiffies_to_timeval(interval, &value->it_interval);
	45	break;
	46	case ITIMER_VIRTUAL:
	47	read_lock(&tasklist_lock);
	48	spin_lock_irq(&tsk->sighand->siglock);
	49	cval = tsk->signal->it_virt_expires;
	50	cinterval = tsk->signal->it_virt_incr;
	51	if (!cputime_eq(cval, cputime_zero)) {
	52	struct task_struct *t = tsk;
	53	cputime_t utime = tsk->signal->utime;
	54	do {
	55	utime = cputime_add(utime, t->utime);
	56	t = next_thread(t);
	57	} while (t != tsk);
	58	if (cputime_le(cval, utime)) { /* about to fire */
	59	cval = jiffies_to_cputime(1);
	60	} else {
	61	cval = cputime_sub(cval, utime);
	62	}
	63	}
	64	spin_unlock_irq(&tsk->sighand->siglock);
65	read_unlock(&tasklist_lock);
66	cputime_to_timeval(cval, &value->it_value);
67	cputime_to_timeval(cinterval, &value->it_interval);
68	break;
69	case ITIMER_PROF:
70	read_lock(&tasklist_lock);
71	spin_lock_irq(&tsk->sighand->siglock);
72	cval = tsk->signal->it_prof_expires;
73	cinterval = tsk->signal->it_prof_incr;
74	if (!cputime_eq(cval, cputime_zero)) {
75	struct task_struct *t = tsk;
76	cputime_t ptime = cputime_add(tsk->signal->utime,
77	tsk->signal->stime);
78	do {
79	ptime = cputime_add(ptime,
80	cputime_add(t->utime,
81	t->stime));
82	t = next_thread(t);
83	} while (t != tsk);
84	if (cputime_le(cval, ptime)) { /* about to fire */
85	cval = jiffies_to_cputime(1);
86	} else {
87	cval = cputime_sub(cval, ptime);
88	}
89	}
90	spin_unlock_irq(&tsk->sighand->siglock);
91	read_unlock(&tasklist_lock);
92	cputime_to_timeval(cval, &value->it_value);
93	cputime_to_timeval(cinterval, &value->it_interval);
94	break;
95	default:
96	return(-EINVAL);
97	}
98	return 0;
99	}
100
101	asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
102	{
103	int error = -EFAULT;
104	struct itimerval get_buffer;
105
106	if (value) {
107	error = do_getitimer(which, &get_buffer);
108	if (!error &&
109	copy_to_user(value, &get_buffer, sizeof(get_buffer)))
110	error = -EFAULT;
111	}
112	return error;
113	}
114
1da177e4 LT	115
	116	void it_real_fn(unsigned long __data)
	117	{
	118	struct task_struct * p = (struct task_struct *) __data;
d912d1ff	119	unsigned long inc = p->signal->it_real_incr;
1da177e4 LT	120
	121	send_group_sig_info(SIGALRM, SEND_SIG_PRIV, p);
	122
	123	/*
	124	* Now restart the timer if necessary. We don't need any locking
	125	* here because do_setitimer makes sure we have finished running
	126	* before it touches anything.
d912d1ff GA	127	* Note, we KNOW we are (or should be) at a jiffie edge here so
	128	* we don't need the +1 stuff. Also, we want to use the prior
	129	* expire value so as to not "slip" a jiffie if we are late.
	130	* Deal with requesting a time prior to "now" here rather than
	131	* in add_timer.
1da177e4	132	*/
d912d1ff GA	133	if (!inc)
	134	return;
	135	while (time_before_eq(p->signal->real_timer.expires, jiffies))
	136	p->signal->real_timer.expires += inc;
	137	add_timer(&p->signal->real_timer);
1da177e4 LT	138	}
	139
	140	int do_setitimer(int which, struct itimerval value, struct itimerval ovalue)
	141	{
	142	struct task_struct *tsk = current;
d912d1ff	143	unsigned long val, interval, expires;
1da177e4 LT	144	cputime_t cval, cinterval, nval, ninterval;
	145
	146	switch (which) {
	147	case ITIMER_REAL:
f01b1b0b	148	again:
1da177e4 LT	149	spin_lock_irq(&tsk->sighand->siglock);
	150	interval = tsk->signal->it_real_incr;
	151	val = it_real_value(tsk->signal);
f01b1b0b ON	152	/* We are sharing ->siglock with it_real_fn() */
	153	if (try_to_del_timer_sync(&tsk->signal->real_timer) < 0) {
	154	spin_unlock_irq(&tsk->sighand->siglock);
	155	goto again;
	156	}
1da177e4 LT	157	tsk->signal->it_real_incr =
1da177e4 LT	158	timeval_to_jiffies(&value->it_interval);
d912d1ff GA	159	expires = timeval_to_jiffies(&value->it_value);
	160	if (expires)
	161	mod_timer(&tsk->signal->real_timer,
	162	jiffies + 1 + expires);
1da177e4 LT	163	spin_unlock_irq(&tsk->sighand->siglock);
	164	if (ovalue) {
	165	jiffies_to_timeval(val, &ovalue->it_value);
	166	jiffies_to_timeval(interval,
	167	&ovalue->it_interval);
	168	}
	169	break;
	170	case ITIMER_VIRTUAL:
	171	nval = timeval_to_cputime(&value->it_value);
	172	ninterval = timeval_to_cputime(&value->it_interval);
	173	read_lock(&tasklist_lock);
	174	spin_lock_irq(&tsk->sighand->siglock);
	175	cval = tsk->signal->it_virt_expires;
	176	cinterval = tsk->signal->it_virt_incr;
	177	if (!cputime_eq(cval, cputime_zero) \|\|
	178	!cputime_eq(nval, cputime_zero)) {
	179	if (cputime_gt(nval, cputime_zero))
	180	nval = cputime_add(nval,
	181	jiffies_to_cputime(1));
	182	set_process_cpu_timer(tsk, CPUCLOCK_VIRT,
	183	&nval, &cval);
	184	}
	185	tsk->signal->it_virt_expires = nval;
	186	tsk->signal->it_virt_incr = ninterval;
	187	spin_unlock_irq(&tsk->sighand->siglock);
	188	read_unlock(&tasklist_lock);
	189	if (ovalue) {
	190	cputime_to_timeval(cval, &ovalue->it_value);
	191	cputime_to_timeval(cinterval, &ovalue->it_interval);
	192	}
	193	break;
	194	case ITIMER_PROF:
	195	nval = timeval_to_cputime(&value->it_value);
	196	ninterval = timeval_to_cputime(&value->it_interval);
	197	read_lock(&tasklist_lock);
	198	spin_lock_irq(&tsk->sighand->siglock);
	199	cval = tsk->signal->it_prof_expires;
	200	cinterval = tsk->signal->it_prof_incr;
	201	if (!cputime_eq(cval, cputime_zero) \|\|
	202	!cputime_eq(nval, cputime_zero)) {
	203	if (cputime_gt(nval, cputime_zero))
	204	nval = cputime_add(nval,
	205	jiffies_to_cputime(1));
	206	set_process_cpu_timer(tsk, CPUCLOCK_PROF,
	207	&nval, &cval);
	208	}
	209	tsk->signal->it_prof_expires = nval;
	210	tsk->signal->it_prof_incr = ninterval;
	211	spin_unlock_irq(&tsk->sighand->siglock);
	212	read_unlock(&tasklist_lock);
	213	if (ovalue) {
	214	cputime_to_timeval(cval, &ovalue->it_value);
	215	cputime_to_timeval(cinterval, &ovalue->it_interval);
	216	}
	217	break;
	218	default:
	219	return -EINVAL;
	220	}
	221	return 0;
	222	}
	223
	224	asmlinkage long sys_setitimer(int which,
	225	struct itimerval __user *value,
	226	struct itimerval __user *ovalue)
227	{
228	struct itimerval set_buffer, get_buffer;
229	int error;
230
231	if (value) {
232	if(copy_from_user(&set_buffer, value, sizeof(set_buffer)))
233	return -EFAULT;
234	} else
235	memset((char *) &set_buffer, 0, sizeof(set_buffer));
236
237	error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL);
238	if (error \|\| !ovalue)
239	return error;
240
241	if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))
242	return -EFAULT;
243	return 0;
244	}