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/time.h>
14 #include <asm/uaccess.h>
16 int do_getitimer(int which, struct itimerval *value)
18 register unsigned long val, interval;
22 interval = current->it_real_incr;
25 * FIXME! This needs to be atomic, in case the kernel timer happens!
27 if (timer_pending(¤t->real_timer)) {
28 val = current->real_timer.expires - jiffies;
30 /* look out for negative/zero itimer.. */
36 val = current->it_virt_value;
37 interval = current->it_virt_incr;
40 val = current->it_prof_value;
41 interval = current->it_prof_incr;
46 jiffies_to_timeval(val, &value->it_value);
47 jiffies_to_timeval(interval, &value->it_interval);
51 /* SMP: Only we modify our itimer values. */
52 asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
55 struct itimerval get_buffer;
58 error = do_getitimer(which, &get_buffer);
60 copy_to_user(value, &get_buffer, sizeof(get_buffer)))
66 void it_real_fn(unsigned long __data)
68 struct task_struct * p = (struct task_struct *) __data;
69 unsigned long interval;
71 send_group_sig_info(SIGALRM, SEND_SIG_PRIV, p);
72 interval = p->it_real_incr;
74 if (interval > (unsigned long) LONG_MAX)
76 p->real_timer.expires = jiffies + interval;
77 add_timer(&p->real_timer);
81 int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
83 register unsigned long i, j;
86 i = timeval_to_jiffies(&value->it_interval);
87 j = timeval_to_jiffies(&value->it_value);
88 if (ovalue && (k = do_getitimer(which, ovalue)) < 0)
92 del_timer_sync(¤t->real_timer);
93 current->it_real_value = j;
94 current->it_real_incr = i;
97 if (j > (unsigned long) LONG_MAX)
100 current->real_timer.expires = i;
101 add_timer(¤t->real_timer);
106 current->it_virt_value = j;
107 current->it_virt_incr = i;
112 current->it_prof_value = j;
113 current->it_prof_incr = i;
121 /* SMP: Again, only we play with our itimers, and signals are SMP safe
122 * now so that is not an issue at all anymore.
124 asmlinkage long sys_setitimer(int which,
125 struct itimerval __user *value,
126 struct itimerval __user *ovalue)
128 struct itimerval set_buffer, get_buffer;
132 if(copy_from_user(&set_buffer, value, sizeof(set_buffer)))
135 memset((char *) &set_buffer, 0, sizeof(set_buffer));
137 error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : 0);
138 if (error || !ovalue)
141 if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))