Re: [RFC PATCH v2 5/8] arm64: Detect an FTRACE frame and mark a stack trace unreliable

From: Madhavan T. Venkataraman
Date: Tue Mar 23 2021 - 10:16:50 EST

Hi Mark,

I have a general question. When exceptions are nested, how does it work? Let us consider 2 cases:

1. Exception in a page fault handler itself. In this case, I guess one more pt_regs will get
established in the task stack for the second exception.

2. Exception in an interrupt handler. Here the interrupt handler is running on the IRQ stack.
Will the pt_regs get created on the IRQ stack?

Also, is there a maximum nesting for exceptions?