146 lines
3.3 KiB
C
146 lines
3.3 KiB
C
/*
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* linux/kernel/itimer.c
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*
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* Copyright (C) 1992 Darren Senn
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*/
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/* These are all the functions necessary to implement itimers */
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#include <linux/mm.h>
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#include <linux/smp_lock.h>
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#include <linux/interrupt.h>
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#include <linux/syscalls.h>
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#include <linux/time.h>
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#include <asm/uaccess.h>
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int do_getitimer(int which, struct itimerval *value)
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{
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register unsigned long val, interval;
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switch (which) {
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case ITIMER_REAL:
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interval = current->it_real_incr;
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val = 0;
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/*
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* FIXME! This needs to be atomic, in case the kernel timer happens!
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*/
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if (timer_pending(¤t->real_timer)) {
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val = current->real_timer.expires - jiffies;
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/* look out for negative/zero itimer.. */
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if ((long) val <= 0)
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val = 1;
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}
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break;
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case ITIMER_VIRTUAL:
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val = current->it_virt_value;
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interval = current->it_virt_incr;
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break;
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case ITIMER_PROF:
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val = current->it_prof_value;
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interval = current->it_prof_incr;
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break;
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default:
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return(-EINVAL);
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}
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jiffies_to_timeval(val, &value->it_value);
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jiffies_to_timeval(interval, &value->it_interval);
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return 0;
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}
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/* SMP: Only we modify our itimer values. */
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asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
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{
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int error = -EFAULT;
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struct itimerval get_buffer;
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if (value) {
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error = do_getitimer(which, &get_buffer);
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if (!error &&
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copy_to_user(value, &get_buffer, sizeof(get_buffer)))
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error = -EFAULT;
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}
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return error;
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}
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void it_real_fn(unsigned long __data)
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{
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struct task_struct * p = (struct task_struct *) __data;
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unsigned long interval;
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send_group_sig_info(SIGALRM, SEND_SIG_PRIV, p);
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interval = p->it_real_incr;
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if (interval) {
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if (interval > (unsigned long) LONG_MAX)
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interval = LONG_MAX;
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p->real_timer.expires = jiffies + interval;
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add_timer(&p->real_timer);
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}
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}
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int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
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{
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register unsigned long i, j;
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int k;
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i = timeval_to_jiffies(&value->it_interval);
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j = timeval_to_jiffies(&value->it_value);
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if (ovalue && (k = do_getitimer(which, ovalue)) < 0)
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return k;
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switch (which) {
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case ITIMER_REAL:
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del_timer_sync(¤t->real_timer);
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current->it_real_value = j;
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current->it_real_incr = i;
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if (!j)
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break;
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if (j > (unsigned long) LONG_MAX)
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j = LONG_MAX;
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i = j + jiffies;
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current->real_timer.expires = i;
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add_timer(¤t->real_timer);
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break;
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case ITIMER_VIRTUAL:
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if (j)
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j++;
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current->it_virt_value = j;
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current->it_virt_incr = i;
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break;
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case ITIMER_PROF:
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if (j)
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j++;
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current->it_prof_value = j;
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current->it_prof_incr = i;
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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/* SMP: Again, only we play with our itimers, and signals are SMP safe
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* now so that is not an issue at all anymore.
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*/
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asmlinkage long sys_setitimer(int which,
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struct itimerval __user *value,
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struct itimerval __user *ovalue)
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{
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struct itimerval set_buffer, get_buffer;
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int error;
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if (value) {
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if(copy_from_user(&set_buffer, value, sizeof(set_buffer)))
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return -EFAULT;
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} else
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memset((char *) &set_buffer, 0, sizeof(set_buffer));
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error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL);
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if (error || !ovalue)
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return error;
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if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))
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return -EFAULT;
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return 0;
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}
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