# ptrace_scope In case the kernel was compiled with the `yama` security module (`CONFIG_SECURITY_YAMA`), tracing processes with `ptrace(2)` can be restricted. ```config /proc/sys/kernel/yama/ptrace_scope 0 => No restrictions. 1 => Restricted attach, only the following can attach - A process in the parent hierarchy. - A process with CAP_SYS_PTRACE. - A process with the PID that the tracee allowed by via PR_SET_PTRACER. 2 => Only processes with CAP_SYS_PTRACE in the user namespace of the tracee can attach. 3 => No tracing allowed. ``` Further details in [`ptrace(2)`][man-ptrace]. [man-ptrace]: https://man7.org/linux/man-pages/man2/ptrace.2.html