Stack pointer switch validity checking

Abstract

Processing circuitryperforms a stack pointer switch validity checking operation associated with a switch of the stack pointer from an outgoing stack pointer value to an incoming stack pointer value. The validity checking operation comprises verifying whether an incoming data value obtained by memory access circuitryin response to a memory access request specifying an address determined based on the incoming stack pointer value meets at least one stack cap value validity condition, including a condition that a predetermined portion of the incoming data value corresponds to a given page address indicative of a page of address space comprising the address determined based on the incoming stack pointer value. The at least one stack cap value validity condition is determined independent of whether a further portion of the incoming data value other than the predetermined portion corresponds to sub-page address bits of the address determined based on the incoming stack pointer value. An error handling response is triggered in response to determining that the incoming data value fails to meet the at least one stack cap value validity condition.