In an embodiment, dynamically-generated code may be supported in the system by ensuring that the code either remains executing within a predefined region of memory or exits to one of a set of valid exit addresses. Software embodiments are described in which the dynamically-generated code is scanned prior to permitting execution of the dynamically-generated code to ensure that various criteria are met including exclusion of certain disallowed instructions and control of branch target addresses. Hardware embodiments are described in which the dynamically-generated code is permitted to executed but is monitored to ensure that the execution criteria are met.