Cannot be attached to an existing process

[prcuzz]

Hi, I'm trying to track the process containerd, but I always get no output.

I used the following command, which did not produce any output:

sudo python3 strace.py -f -p 1363

I also tried the example in the documentation and rewrote it to:

import signal

import ptrace.debugger


def debugger_example(pid):
    debugger = ptrace.debugger.PtraceDebugger()

    print("Attach the running process %s" % pid)
    process = debugger.addProcess(pid, False)
    # process is a PtraceProcess instance
    print("IP before: %#x" % process.getInstrPointer())

    print("Execute a single step")
    process.singleStep()
    # singleStep() gives back control to the process. We have to wait
    # until the process is trapped again to retrieve the control on the
    # process.
    process.waitSignals(signal.SIGTRAP)
    print("IP after: %#x" % process.getInstrPointer())

    process.detach()
    debugger.quit()


def main():
    debugger_example(1363)


if __name__ == "__main__":
    main()

The error obtained is the following,

/home/zzc/Desktop/zzc/python3.6_sudo.sh /home/zzc/Desktop/zzc/python-ptrace/zzc-test.py
Attach the running process 1363
Traceback (most recent call last):
  File "/home/zzc/Desktop/zzc/python-ptrace/zzc-test.py", line 30, in <module>
    main()
  File "/home/zzc/Desktop/zzc/python-ptrace/zzc-test.py", line 26, in main
    debugger_example(1363)
  File "/home/zzc/Desktop/zzc/python-ptrace/zzc-test.py", line 10, in debugger_example
    process = debugger.addProcess(pid, False)
  File "/home/zzc/Desktop/zzc/python-ptrace/ptrace/debugger/debugger.py", line 83, in addProcess
    parent=parent, is_thread=is_thread)
  File "/home/zzc/Desktop/zzc/python-ptrace/ptrace/debugger/process.py", line 172, in __init__
    self.attach()
  File "/home/zzc/Desktop/zzc/python-ptrace/ptrace/debugger/process.py", line 189, in attach
    ptrace_attach(self.pid)
  File "/home/zzc/Desktop/zzc/python-ptrace/ptrace/binding/func.py", line 177, in ptrace_attach
    ptrace(PTRACE_ATTACH, pid)
  File "/home/zzc/Desktop/zzc/python-ptrace/ptrace/binding/func.py", line 168, in ptrace
    raise PtraceError(message, errno=errno, pid=pid)
ptrace.error.PtraceError: ptrace(cmd=16, pid=1363, 0, 0) error #1: Operation not permitted

Process finished with exit code 1

I want to know what I should do.