Cygwin kill utility //Was: cgwin_internal(): difference b/w CW_CYGWIN_PID_TO_WINPID and CW_GETPINFO_FULL for taking only dwProcessId ?

[Lavrentiev, Anton (NIH/NLM/NCBI) [C]]

Hello,

It looks like in order to effectively kill the process by Windows means (i.e. 
what Cygwin "kill -f" is supposed to do),
the process handle must be obtained with the SYNCHRONIZE right (in addition to 
PROCESS_TERMINATE), otherwise
WaitForSingleObject() fails with code 5, permission denied (at least for a 
regular user, i.e. not an administrator).

That's about this portion of kill.cc located at winsup\utils:

  HANDLE h = OpenProcess (PROCESS_TERMINATE, FALSE, (DWORD) dwpid);
  if (!h)
    {
      if (!wait || GetLastError () != ERROR_INVALID_PARAMETER)
        fprintf (stderr, "%s: couldn't open pid %u\n",
                 prog_name, (unsigned) dwpid);
      return;
    }
  if (!wait || WaitForSingleObject (h, 200) != WAIT_OBJECT_0)
    if (sig && !TerminateProcess (h, sig << 8)
        && WaitForSingleObject (h, 200) != WAIT_OBJECT_0)
      fprintf (stderr, "%s: couldn't kill pid %u, %lu\n",
               prog_name, (unsigned) dwpid, GetLastError ());

MSDN is in agreement with the observed behavior (access denied),

http://msdn.microsoft.com/en-us/library/windows/desktop/ms684320%28v=vs.85%29.aspx

<quote>
The handle returned by the OpenProcess function can be used in any function 
that requires a handle to a process, such as the wait functions, provided the 
appropriate access rights were requested.
</quote>

http://msdn.microsoft.com/en-us/library/windows/desktop/ms684880%28v=vs.85%29.aspx

HTH,

Anton Lavrentiev
Contractor NIH/NLM/NCBI