fn do_prctl(r: &Req<'_>) -> Result<Outcome, i32>Expand description
prctl(PR_SET_DUMPABLE) and PR_GET_DUMPABLE.
The flag is remembered for the process and never cleared in the kernel:
a non-dumpable tracee is unreachable through process_vm_readv,
/proc/<pid>/mem and /proc/<pid>/fd for a supervisor without
CAP_SYS_PTRACE, and every path syscall it made would fail with EACCES.
Other options reach the handler only through a filter without the
argument check and run natively.
§Returns
0 for a set of 0 or 1, the remembered flag for a get.
§Errors
EINVAL for a value the kernel refuses.