static int x86_pmu_add(struct perf_event *event, int flags)
{
	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
	struct hw_perf_event *hwc;
	int assign[X86_PMC_IDX_MAX];
	int n, n0, ret;

	hwc = &event->hw;

	perf_pmu_disable(event->pmu);
	n0 = cpuc->n_events;
	ret = n = collect_events(cpuc, event, false);
	if (ret < 0)
		goto out;

	hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
	if (!(flags & PERF_EF_START))
		hwc->state |= PERF_HES_ARCH;

	/*
	 * If group events scheduling transaction was started,
	 * skip the schedulability test here, it will be peformed
	 * at commit time (->commit_txn) as a whole
	 */
	if (cpuc->group_flag & PERF_EVENT_TXN)
		goto done_collect;

	ret = x86_pmu.schedule_events(cpuc, n, assign);
	if (ret)
		goto out;
	/*
	 * copy new assignment, now we know it is possible
	 * will be used by hw_perf_enable()
	 */
	memcpy(cpuc->assign, assign, n*sizeof(int));

done_collect:
	cpuc->n_events = n;
	cpuc->n_added += n - n0;
	cpuc->n_txn += n - n0;

	ret = 0;
out:
	perf_pmu_enable(event->pmu);
	return ret;
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.