hurd/hurdkill.c

   1 /* Copyright (C) 1991-2020 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <sys/types.h>
  20 #include <signal.h>
  21 #include <hurd.h>
  22 #include <hurd/port.h>
  23 #include <hurd/signal.h>
  24 #include <hurd/msg.h>
  25
  26 /* Send a `sig_post' RPC to process number PID.  If PID is zero,
  27    send the message to all processes in the current process's process group.
  28    If PID is < -1, send SIG to all processes in process group - PID.
  29    SIG and REFPORT are passed along in the request message.  */
  30 error_t
  31 _hurd_sig_post (pid_t pid, int sig, mach_port_t arg_refport)
  32 {
  33   int delivered = 0;            /* Set when we deliver any signal.  */
  34   error_t err;
  35   mach_port_t proc;
  36   struct hurd_userlink ulink;
  37
  38   inline void kill_pid (pid_t pid) /* Kill one PID.  */
  39     {
  40       err = HURD_MSGPORT_RPC (__proc_getmsgport (proc, pid, &msgport),
  41                               (refport = arg_refport, 0), 0,
  42                               /* If no message port we cannot send signals.  */
  43                               msgport == MACH_PORT_NULL ? EPERM
  44                               : __msg_sig_post (msgport, sig, 0, refport));
  45       if (! err)
  46         delivered = 1;
  47     }
  48
  49   proc = _hurd_port_get (&_hurd_ports[INIT_PORT_PROC], &ulink);
  50
  51   if (pid <= 0)
  52     {
  53       /* Send SIG to each process in pgrp (- PID).  */
  54       mach_msg_type_number_t npids = 10, i;
  55       pid_t pidsbuf[10], *pids = pidsbuf;
  56
  57       err = __proc_getpgrppids (proc, - pid, &pids, &npids);
  58       if (!err)
  59         {
  60           int self = 0;
  61           for (i = 0; i < npids; ++i)
  62             if (pids[i] == _hurd_pid)
  63               /* We must do ourselves last so we are not suspended
  64                  and fail to suspend the other processes in the pgrp.  */
  65               self = 1;
  66             else
  67               {
  68                 kill_pid (pids[i]);
  69                 if (err == ESRCH)
  70                   /* The process died already.  Ignore it.  */
  71                   err = 0;
  72               }
  73           if (pids != pidsbuf)
  74             __vm_deallocate (__mach_task_self (),
  75                              (vm_address_t) pids, npids * sizeof (pids[0]));
  76
  77           if (self)
  78             kill_pid (_hurd_pid);
  79         }
  80     }
  81   else
  82     kill_pid (pid);
  83
  84   _hurd_port_free (&_hurd_ports[INIT_PORT_PROC], &ulink, proc);
  85
  86   /* If we delivered no signals, but ERR is clear, this must mean that
  87      every kill_pid call failed with ESRCH, meaning all the processes in
  88      the pgrp died between proc_getpgrppids and kill_pid; in that case we
  89      fail with ESRCH.  */
  90   return delivered ? 0 : err ?: ESRCH;
  91 }
  92 weak_alias (_hurd_sig_post, hurd_sig_post)