static bool pmc_overflow(unsigned long val)
{
	if ((int)val < 0)
		return true;

	/*
	 * Events on POWER7 can roll back if a speculative event doesn't
	 * eventually complete. Unfortunately in some rare cases they will
	 * raise a performance monitor exception. We need to catch this to
	 * ensure we reset the PMC. In all cases the PMC will be 256 or less
	 * cycles from overflow.
	 *
	 * We only do this if the first pass fails to find any overflowing
	 * PMCs because a user might set a period of less than 256 and we
	 * don't want to mistakenly reset them.
	 */
	if (__is_processor(PV_POWER7) && ((0x80000000 - val) <= 256))
		return true;

	return false;
}
Weaknesses in this category are related to improper calculation or conversion of numbers.