what is exceptions?

      

                          Indeed, they are often called synchronous interrupts . Exceptions are produced by the processor while executing instructions either in response to a programming error (for example, divide by zero) or abnormal conditions that must be handled by the kernel (for example, a page fault). Because many processor architectures handle exceptions in a similar manner to interrupts, the kernel infrastructure for handling the two is similar. Much of the discussion of interrupts (asynchronous interrupts generated by hardware) in this chapter also pertains to exceptions (synchronous interrupts generated by the processor itself).