A friendly wrapper around the Linux ptrace(2)
system call.
The ptrace(2)
interface entails interpreting a series of wait(2)
statuses. The context used
to interpret a status includes the attach options set on each tracee, previously-seen stops,
recent ptrace
requests, and in some cases, extra event data that must be queried using
additional ptrace
calls.
Pete is meant to instead permit reasoning directly about ptrace-stops, as described in the manual. We hide the lowest-level contextual bookkeeping required to disambiguate ptrace-stops. Whenever we can, we avoid extraneous ptrace calls, deferring to downstream tracers implemented on top of the library. For example, Pete can distinguish a syscall-enter-stop and syscall-exit-stop, but does not automatically query register state to identify the specific syscall.