X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fitimer.c;h=ab982747d9bd8121c19b3327b96c7760adb7577e;hb=d839fd4d2e95a5fbc4d50aa9d17eed6a5f2094e6;hp=c2c05c4ff28d5bd7bd32cf8ca1eea1dc768b71c2;hpb=e7de369050534025b33aab1033358bf47a577e4d;p=linux-2.6-omap-h63xx.git

diff --git a/kernel/itimer.c b/kernel/itimer.c
index c2c05c4ff28..ab982747d9b 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -7,7 +7,6 @@
 /* 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>
@@ -49,9 +48,11 @@ int do_getitimer(int which, struct itimerval *value)
 
 	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);
@@ -126,21 +127,22 @@ asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
 /*
  * The timer is automagically restarted, when interval != 0
  */
-int it_real_fn(void *data)
+enum hrtimer_restart it_real_fn(struct hrtimer *timer)
 {
-	struct task_struct *tsk = (struct task_struct *) data;
+	struct signal_struct *sig =
+		container_of(timer, struct signal_struct, real_timer);
 
-	send_group_sig_info(SIGALRM, SEND_SIG_PRIV, tsk);
+	kill_pid_info(SIGALRM, SEND_SIG_PRIV, sig->leader_pid);
 
-	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;
 }
 
+/*
+ * Returns true if the timeval is in canonical form
+ */
+#define timeval_valid(t) \
+	(((t)->tv_sec >= 0) && (((unsigned long) (t)->tv_usec) < USEC_PER_SEC))
+
 int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
 {
 	struct task_struct *tsk = current;
@@ -148,20 +150,37 @@ int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
 	ktime_t expires;
 	cputime_t cval, cinterval, nval, ninterval;
 
+	/*
+	 * Validate the timevals in value.
+	 */
+	if (!timeval_valid(&value->it_value) ||
+	    !timeval_valid(&value->it_interval))
+		return -EINVAL;
+
 	switch (which) {
 	case ITIMER_REAL:
+again:
+		spin_lock_irq(&tsk->sighand->siglock);
 		timer = &tsk->signal->real_timer;
-		hrtimer_cancel(timer);
 		if (ovalue) {
 			ovalue->it_value = itimer_get_remtime(timer);
 			ovalue->it_interval
 				= ktime_to_timeval(tsk->signal->it_real_incr);
 		}
-		tsk->signal->it_real_incr =
-			timeval_to_ktime(value->it_interval);
+		/* We are sharing ->siglock with it_real_fn() */
+		if (hrtimer_try_to_cancel(timer) < 0) {
+			spin_unlock_irq(&tsk->sighand->siglock);
+			goto again;
+		}
 		expires = timeval_to_ktime(value->it_value);
-		if (expires.tv64 != 0)
-			hrtimer_start(timer, expires, HRTIMER_REL);
+		if (expires.tv64 != 0) {
+			tsk->signal->it_real_incr =
+				timeval_to_ktime(value->it_interval);
+			hrtimer_start(timer, expires, HRTIMER_MODE_REL);
+		} else
+			tsk->signal->it_real_incr.tv64 = 0;
+
+		spin_unlock_irq(&tsk->sighand->siglock);
 		break;
 	case ITIMER_VIRTUAL:
 		nval = timeval_to_cputime(&value->it_value);
@@ -217,6 +236,43 @@ int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
 	return 0;
 }
 
+/**
+ * alarm_setitimer - set alarm in seconds
+ *
+ * @seconds:	number of seconds until alarm
+ *		0 disables the alarm
+ *
+ * Returns the remaining time in seconds of a pending timer or 0 when
+ * the timer is not active.
+ *
+ * On 32 bit machines the seconds value is limited to (INT_MAX/2) to avoid
+ * negative timeval settings which would cause immediate expiry.
+ */
+unsigned int alarm_setitimer(unsigned int seconds)
+{
+	struct itimerval it_new, it_old;
+
+#if BITS_PER_LONG < 64
+	if (seconds > INT_MAX)
+		seconds = INT_MAX;
+#endif
+	it_new.it_value.tv_sec = seconds;
+	it_new.it_value.tv_usec = 0;
+	it_new.it_interval.tv_sec = it_new.it_interval.tv_usec = 0;
+
+	do_setitimer(ITIMER_REAL, &it_new, &it_old);
+
+	/*
+	 * We can't return 0 if we have an alarm pending ...  And we'd
+	 * better return too much than too little anyway
+	 */
+	if ((!it_old.it_value.tv_sec && it_old.it_value.tv_usec) ||
+	      it_old.it_value.tv_usec >= 500000)
+		it_old.it_value.tv_sec++;
+
+	return it_old.it_value.tv_sec;
+}
+
 asmlinkage long sys_setitimer(int which,
 			      struct itimerval __user *value,
 			      struct itimerval __user *ovalue)
@@ -235,6 +291,6 @@ asmlinkage long sys_setitimer(int which,
 		return error;
 
 	if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))
-		return -EFAULT; 
+		return -EFAULT;
 	return 0;
 }