OSdev, Task State Segment and stacks?

Question

Programming

Two questions:
1. With the help of TSS it is possible to ensure that the stack changes during interruption and rip, cs, flags, rsp, ss are written there, to the new stack?
2. Do you need a zero ring stack for each task, or is only one per processor enough?

Answer 1

1. Yes, the third volume of the intel 64 and ia32 architecture software developer's manual, section 6.12.2 Interrupt Tasks, speaks directly about this.
2. Depends solely on your implementation. In Linux, for example, each task has its own kernel mode stack.