On Tue, Mar 23, 2021 at 10:26:50AM -0500, Madhavan T. Venkataraman wrote: > On 3/23/21 9:57 AM, Mark Rutland wrote: > Thanks for explaining the nesting. It is now clear to me. No problem! > So, my next question is - can we define a practical limit for the > nesting so that any nesting beyond that is fatal? The reason I ask is > - if there is a max, then we can allocate an array of stack frames out > of band for the special frames so they are not part of the stack and > will not likely get corrupted. I suspect we can't define such a fatal limit without introducing a local DoS vector on some otherwise legitimate workload, and I fear this will further complicate the entry/exit logic, so I'd prefer to avoid introducing a new limit. What exactly do you mean by a "special frame", and why do those need additional protection over regular frame records? > Also, we don't have to do any special detection. If the number of out > of band frames used is one or more then we have exceptions and the > stack trace is unreliable. What is expected to protect against? Thanks, Mark.
