Note: I saw a similar question to part II get answered by a guy who just posted a graph. Please provide an answer in words, or I will thumbs down automatically.

uestion # 4 I.If a user program needs to perform IO, it needs to trap the OS via a system call that transfers control to the kernel. The kernel performs I/O on behalf of the user program. However, systems calls have added overheads, which can slow down the entire system. In that case, why not let user processes perform I/O directly, without going through the kernel? Consider a computer running in the user mode. It will switch to the monitor mode whenever an interrupt or trap occurs, jumping to the address determined from the nterrupt vector A smart, but malicious, user took advantage of a certain serious loophole in the computer's protection mechanism, by which he could make run his own user program in the monitor mode! This can cause disastrous effects What could have he possibly done to achieve this? What disastrous effects could it cause? Suggest a remedy for the loophole