250 lines
6.6 KiB
C
250 lines
6.6 KiB
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;
|
|
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;
|
|
}
|
|
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;
|
|
}
|