From: Oleg Nesterov Afaics, currently there are no kernel problems with ptracing init, it can't lose SIGNAL_UNKILLABLE flag and be killed/stopped by accident. The ability to strace/debug init can be very useful if you try to figure out why it does not work as expected. However, admin should know what he does, "gdb /sbin/init 1" stops init, it can't reap orphaned zombies or take care of /etc/inittab until continued. It is even possible to crash init (and thus the whole system) if you wish, ptracer has full control. See also the long discussion: http://marc.info/?t=120628018600001 Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath Signed-off-by: Andrew Morton --- kernel/ptrace.c | 8 -------- 1 file changed, 8 deletions(-) diff -puN kernel/ptrace.c~ptrace-allow-to-ptrace-sbin-init kernel/ptrace.c --- a/kernel/ptrace.c~ptrace-allow-to-ptrace-sbin-init +++ a/kernel/ptrace.c @@ -168,8 +168,6 @@ int ptrace_attach(struct task_struct *ta audit_ptrace(task); retval = -EPERM; - if (task->pid <= 1) - goto out; if (same_thread_group(task, current)) goto out; @@ -517,12 +515,6 @@ struct task_struct *ptrace_get_task_stru { struct task_struct *child; - /* - * Tracing init is not allowed. - */ - if (pid == 1) - return ERR_PTR(-EPERM); - read_lock(&tasklist_lock); child = find_task_by_vpid(pid); if (child) _