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glibc  2.9
kill.c File Reference
#include <errno.h>
#include <sys/types.h>
#include <signal.h>
#include <hurd.h>
#include <hurd/port.h>
#include <hurd/signal.h>
#include <hurd/msg.h>

Go to the source code of this file.


int __kill (pid_t pid, int sig)

Function Documentation

int __kill ( pid_t  pid,
int  sig 

Definition at line 31 of file kill.c.

  int delivered = 0;        /* Set when we deliver any signal.  */
  error_t err;
  mach_port_t proc;
  struct hurd_userlink ulink;

  void kill_pid (pid_t pid) /* Kill one PID.  */
      /* SIGKILL is not delivered as a normal signal.
        Sending SIGKILL to a process means to terminate its task.  */
      if (sig == SIGKILL)
       /* Fetch the process's task port and terminate the task.  We
          loop in case the process execs and changes its task port.
          If the old task port dies after we fetch it but before we
          send the RPC, we get MACH_SEND_INVALID_DEST; if it dies
          after we send the RPC request but before it is serviced, we
          get MIG_SERVER_DIED.  */
           task_t refport;
           err = __proc_pid2task (proc, pid, &refport);
           /* Ignore zombies.  */
           if (!err && refport != MACH_PORT_NULL)
              err = __task_terminate (refport);
              __mach_port_deallocate (__mach_task_self (), refport);
         } while (err == MACH_SEND_INVALID_DEST ||
                 err == MIG_SERVER_DIED);
         error_t taskerr;
         error_t kill_port (mach_port_t msgport, mach_port_t refport)
             if (msgport != MACH_PORT_NULL)
              /* Send a signal message to his message port.  */
              return __msg_sig_post (msgport, sig, 0, refport);

             /* The process has no message port.  Perhaps try direct
               frobnication of the task.  */

             if (taskerr)
              /* If we could not get the task port, we can do nothing.  */
              return taskerr;

             if (refport == MACH_PORT_NULL)
              /* proc_pid2task returned success with a null task port.
                 That means the process is a zombie.  Signals
                 to zombies should return success and do nothing.  */
              return 0;

             /* For user convenience in the case of a task that has
               not registered any message port with the proc server,
               translate a few signals to direct task operations.  */
             switch (sig)
                /* The only signals that really make sense for an
                   unregistered task are kill, suspend, and continue.  */
              case SIGSTOP:
              case SIGTSTP:
                return __task_suspend (refport);
              case SIGCONT:
                return __task_resume (refport);
              case SIGTERM:
              case SIGQUIT:
              case SIGINT:
                return __task_terminate (refport);
                /* We have full permission to send signals, but there is
                   no meaningful way to express this signal.  */
                return EPERM;
         err = HURD_MSGPORT_RPC (__proc_getmsgport (proc, pid, &msgport),
                              (taskerr = __proc_pid2task (proc, pid,
                                                       &refport)) ?
                              __proc_getsidport (proc, &refport) : 0, 1,
                              kill_port (msgport, refport));
      if (! err)
       delivered = 1;

  proc = _hurd_port_get (&_hurd_ports[INIT_PORT_PROC], &ulink);

  if (pid <= 0)
      /* Send SIG to each process in pgrp (- PID).  */
      pid_t pidbuf[10], *pids = pidbuf;
      mach_msg_type_number_t i, npids = sizeof (pidbuf) / sizeof (pidbuf[0]);

      err = __proc_getpgrppids (proc, - pid, &pids, &npids);
      if (!err)
         for (i = 0; i < npids; ++i)
             kill_pid (pids[i]);
             if (err == ESRCH)
              /* The process died already.  Ignore it.  */
              err = 0;
         if (pids != pidbuf)
           __vm_deallocate (__mach_task_self (),
                          (vm_address_t) pids, npids * sizeof (pids[0]));
    kill_pid (pid);

  _hurd_port_free (&_hurd_ports[INIT_PORT_PROC], &ulink, proc);

  /* If we delivered no signals, but ERR is clear, this must mean that
     every kill_pid call failed with ESRCH, meaning all the processes in
     the pgrp died between proc_getpgrppids and kill_pid; in that case we
     fail with ESRCH.  */
  return delivered ? 0 : __hurd_fail (err ?: ESRCH);

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