[Bluetooth] Integrate services into the driver model
[pandora-kernel.git] / kernel / itimer.c
index c2c05c4..204ed79 100644 (file)
@@ -49,9 +49,11 @@ 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 +128,75 @@ asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
 /*
  * The timer is automagically restarted, when interval != 0
  */
-int it_real_fn(void *data)
+int it_real_fn(struct hrtimer *timer)
 {
-       struct task_struct *tsk = (struct task_struct *) data;
-
-       send_group_sig_info(SIGALRM, SEND_SIG_PRIV, tsk);
+       struct signal_struct *sig =
+           container_of(timer, struct signal_struct, real_timer);
 
-       if (tsk->signal->it_real_incr.tv64 != 0) {
-               hrtimer_forward(&tsk->signal->real_timer,
-                              tsk->signal->it_real_incr);
+       send_group_sig_info(SIGALRM, SEND_SIG_PRIV, sig->tsk);
 
+       if (sig->it_real_incr.tv64 != 0) {
+               hrtimer_forward(timer, timer->base->softirq_time,
+                               sig->it_real_incr);
                return HRTIMER_RESTART;
        }
        return HRTIMER_NORESTART;
 }
 
+/*
+ * We do not care about correctness. We just sanitize the values so
+ * the ktime_t operations which expect normalized values do not
+ * break. This converts negative values to long timeouts similar to
+ * the code in kernel versions < 2.6.16
+ *
+ * Print a limited number of warning messages when an invalid timeval
+ * is detected.
+ */
+static void fixup_timeval(struct timeval *tv, int interval)
+{
+       static int warnlimit = 10;
+       unsigned long tmp;
+
+       if (warnlimit > 0) {
+               warnlimit--;
+               printk(KERN_WARNING
+                      "setitimer: %s (pid = %d) provided "
+                      "invalid timeval %s: tv_sec = %ld tv_usec = %ld\n",
+                      current->comm, current->pid,
+                      interval ? "it_interval" : "it_value",
+                      tv->tv_sec, (long) tv->tv_usec);
+       }
+
+       tmp = tv->tv_usec;
+       if (tmp >= USEC_PER_SEC) {
+               tv->tv_usec = tmp % USEC_PER_SEC;
+               tv->tv_sec += tmp / USEC_PER_SEC;
+       }
+
+       tmp = tv->tv_sec;
+       if (tmp > LONG_MAX)
+               tv->tv_sec = LONG_MAX;
+}
+
+/*
+ * 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))
+
+/*
+ * Check for invalid timevals, sanitize them and print a limited
+ * number of warnings.
+ */
+static void check_itimerval(struct itimerval *value) {
+
+       if (unlikely(!timeval_valid(&value->it_value)))
+               fixup_timeval(&value->it_value, 0);
+
+       if (unlikely(!timeval_valid(&value->it_interval)))
+               fixup_timeval(&value->it_interval, 1);
+}
+
 int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
 {
        struct task_struct *tsk = current;
@@ -148,20 +204,39 @@ 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.
+        *
+        * Note: Although the spec requires that invalid values shall
+        * return -EINVAL, we just fixup the value and print a limited
+        * number of warnings in order not to break users of this
+        * historical misfeature.
+        *
+        * Scheduled for replacement in March 2007
+        */
+       check_itimerval(value);
+
        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);
                }
+               /* 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);
@@ -217,6 +292,43 @@ 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)