static bool rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
{
	struct buffer_page *reader = cpu_buffer->reader_page;
	struct buffer_page *head = rb_set_head_page(cpu_buffer);
	struct buffer_page *commit = cpu_buffer->commit_page;

	/* In case of error, head will be NULL */
	if (unlikely(!head))
		return true;

	return reader->read == rb_page_commit(reader) &&
		(commit == reader ||
		 (commit == head &&
		  head->read == rb_page_commit(commit)));
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.