1. A method operational in a processing circuit, comprising: setting a state indicator for a first subset of a plurality of memory pages of executable code in a memory device to a non-executable state; setting the state indicator for a second subset of the plurality of memory pages to an executable state, where the second subset of the plurality of memory pages includes indirection stubs to functions in the first subset of the plurality of memory pages; and directing a function call to a corresponding indirection stub in the second subset of the plurality of memory pages which modifies the state indicator for a corresponding function in the first subset of the plurality of memory pages prior to directing execution of the called function from the first subset of the plurality of memory pages.