2 * linux/kernel/itimer.c
4 * Copyright (C) 1992 Darren Senn
7 /* These are all the functions necessary to implement itimers */
10 #include <linux/smp_lock.h>
11 #include <linux/interrupt.h>
12 #include <linux/syscalls.h>
13 #include <linux/time.h>
15 #include <asm/uaccess.h>
17 int do_getitimer(int which, struct itimerval *value)
19 register unsigned long val, interval;
23 interval = current->it_real_incr;
26 * FIXME! This needs to be atomic, in case the kernel timer happens!
28 if (timer_pending(¤t->real_timer)) {
29 val = current->real_timer.expires - jiffies;
31 /* look out for negative/zero itimer.. */
37 val = current->it_virt_value;
38 interval = current->it_virt_incr;
41 val = current->it_prof_value;
42 interval = current->it_prof_incr;
47 jiffies_to_timeval(val, &value->it_value);
48 jiffies_to_timeval(interval, &value->it_interval);
52 /* SMP: Only we modify our itimer values. */
53 asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
56 struct itimerval get_buffer;
59 error = do_getitimer(which, &get_buffer);
61 copy_to_user(value, &get_buffer, sizeof(get_buffer)))
67 void it_real_fn(unsigned long __data)
69 struct task_struct * p = (struct task_struct *) __data;
70 unsigned long interval;
72 if (send_group_sig_info(SIGALRM, SEND_SIG_PRIV, p))
73 printk("*warning*: failed to send SIGALRM to %u\n", p->pid);
75 interval = p->it_real_incr;
77 if (interval > (unsigned long) LONG_MAX)
79 p->real_timer.expires = jiffies + interval;
80 add_timer(&p->real_timer);
84 int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
86 register unsigned long i, j;
89 i = timeval_to_jiffies(&value->it_interval);
90 j = timeval_to_jiffies(&value->it_value);
91 if (ovalue && (k = do_getitimer(which, ovalue)) < 0)
95 del_timer_sync(¤t->real_timer);
96 current->it_real_value = j;
97 current->it_real_incr = i;
100 if (j > (unsigned long) LONG_MAX)
103 current->real_timer.expires = i;
104 add_timer(¤t->real_timer);
109 current->it_virt_value = j;
110 current->it_virt_incr = i;
115 current->it_prof_value = j;
116 current->it_prof_incr = i;
124 /* SMP: Again, only we play with our itimers, and signals are SMP safe
125 * now so that is not an issue at all anymore.
127 asmlinkage long sys_setitimer(int which,
128 struct itimerval __user *value,
129 struct itimerval __user *ovalue)
131 struct itimerval set_buffer, get_buffer;
135 if(copy_from_user(&set_buffer, value, sizeof(set_buffer)))
138 memset((char *) &set_buffer, 0, sizeof(set_buffer));
140 error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL);
141 if (error || !ovalue)
144 if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))