linux - Whose stack is used when an interrupt handle is running? -


i trying understand steps followed when interrupt taken account processor. reading understanding linux kernel discovered first of processor needs determine vector associated interrupt, somehow address of isr computed. after checking if interrupt issued authorized source, checked if there change of privilege.

"checks whether change of privilege level taking place—that is, if cpl different selected segment descriptor’s dpl. if so, control unit must start using stack associated new privilege level"

my questions are:

  1. if interrupt runs @ expense of same process running when interrupt occurred, why not using process' kernel stack?
  2. there different stacks different privilege levels? know there kernel stack per process.
  3. if so, why switch of stacks needed?


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