timer: fix overflow bug

This commit is contained in:
Matheus
2024-09-12 20:21:06 -03:00
parent 6e1343d5cc
commit 3c924116ee
+14 -5
View File
@@ -5,6 +5,10 @@
static void insert(timer_t *timer, timerentry_t *entry, time_t us) { static void insert(timer_t *timer, timerentry_t *entry, time_t us) {
entry->absolutetick = timer->tickcurrent + us * timer->ticksperus; entry->absolutetick = timer->tickcurrent + us * timer->ticksperus;
// it overflowed, this will be so far into the future we can just
// set it to be far off enough into the future that it really does not matter.
if (entry->absolutetick < timer->tickcurrent)
entry->absolutetick = timer->ticksperus * 1000 * 1000 * 60 * 60 * 24 * 30 * 12 * 1000; // a thousand years from now.
if (timer->queue == NULL) { // if no other entries in the queue if (timer->queue == NULL) { // if no other entries in the queue
entry->next = NULL; entry->next = NULL;
@@ -32,7 +36,7 @@ static void insert(timer_t *timer, timerentry_t *entry, time_t us) {
} }
} }
// expects IPL to be at least IPL_DPC // expects IPL to be at least IPL_TIMER
static void timercheck(timer_t *timer) { static void timercheck(timer_t *timer) {
while (timer->queue && timer->queue->absolutetick == timer->tickcurrent) { while (timer->queue && timer->queue->absolutetick == timer->tickcurrent) {
timerentry_t *entry = timer->queue; timerentry_t *entry = timer->queue;
@@ -127,11 +131,12 @@ void timer_insert(timer_t *timer, timerentry_t *entry, dpcfn_t fn, dpcarg_t arg,
} }
uintmax_t timer_remove(timer_t *timer, timerentry_t *entry) { uintmax_t timer_remove(timer_t *timer, timerentry_t *entry) {
timer_stop(timer);
long oldipl = interrupt_raiseipl(IPL_TIMER); long oldipl = interrupt_raiseipl(IPL_TIMER);
spinlock_acquire(&timer->lock); spinlock_acquire(&timer->lock);
if (timer->running)
timer->tickcurrent += timer->stop(timer);
uintmax_t timeremaining = 0; uintmax_t timeremaining = 0;
// if it had already fired by the time the lock was reached // if it had already fired by the time the lock was reached
@@ -154,14 +159,18 @@ uintmax_t timer_remove(timer_t *timer, timerentry_t *entry) {
prev->next = iterator->next; prev->next = iterator->next;
iterator->next = NULL; iterator->next = NULL;
// ALWAYS round up the time remaining // ALWAYS round up the time remaining
timeremaining = ROUND_UP(iterator->absolutetick - timer->tickcurrent, timer->ticksperus) / timer->ticksperus; timeremaining = ROUND_UP(iterator->absolutetick - timer->tickcurrent, timer->ticksperus) / timer->ticksperus;
if (timer->queue) {
timercheck(timer);
timer->arm(timer->queue->absolutetick - timer->tickcurrent);
}
cleanup: cleanup:
spinlock_release(&timer->lock); spinlock_release(&timer->lock);
interrupt_loweripl(oldipl); interrupt_loweripl(oldipl);
timer_resume(timer);
return timeremaining; return timeremaining;
} }