PR_SET_PTRACER

Standard C library (libc, -lc)

#include <linux/prctl.h>  /* Definition of PR_* constants */
#include <sys/prctl.h>

int prctl(PR_SET_PTRACER, long pid);

This is meaningful only when the Yama LSM is enabled and in mode 1 ("restricted ptrace", visible via /proc/sys/kernel/yama/ptrace_scope).

When a "ptracer process ID" is passed in pid, the caller is declaring that the ptracer process can ptrace(2) the calling process as if it were a direct process ancestor.

Each PR_SET_PTRACER operation replaces the previous "ptracer process ID".

Employing PR_SET_PTRACER with pid set to 0 clears the caller's "ptracer process ID". If pid is PR_SET_PTRACER_ANY, the ptrace restrictions introduced by Yama are effectively disabled for the calling process.

On success, 0 is returned. On error, -1 is returned, and errno is set to indicate the error.

EINVAL

pid is not 0, PR_SET_PTRACER_ANY, nor the PID of an existing process.

Linux.

Linux 3.4.

prctl(2)

For further information, see the kernel source file Documentation/admin-guide/LSM/Yama.rst.