sysdeps/mach/hurd/waitid.c

   1 /* Implementation of waitid.  Hurd version.
   2    Copyright (C) 1997-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <errno.h>
  21 #include <sys/types.h>
  22 #include <sys/wait.h>
  23 #include <stddef.h>
  24 #include <hurd.h>
  25 #include <hurd/port.h>
  26 #include <hurd/version.h>
  27 #include <sysdep-cancel.h>
  28
  29 int
  30 __waitid (idtype_t idtype, id_t id, siginfo_t *infop, int options)
  31 {
  32   struct rusage ignored;
  33   error_t err;
  34   pid_t pid, child;
  35   int sigcode;
  36   int status;
  37   int cancel_oldtype;
  38
  39   switch (idtype)
  40     {
  41     case P_PID:
  42       if (id <= 0)
  43         goto invalid;
  44       pid = (pid_t) id;
  45       break;
  46     case P_PGID:
  47       if (id < 0 || id == 1)
  48         goto invalid;
  49       pid = (pid_t) -id;
  50       break;
  51     case P_ALL:
  52       pid = -1;
  53       break;
  54     default:
  55     invalid:
  56       __set_errno (EINVAL);
  57       return -1;
  58     }
  59
  60   /* Technically we're supposed to return EFAULT if infop is bogus,
  61      but that would involve mucking with signals, which is
  62      too much hassle.  User will have to deal with SIGSEGV/SIGBUS.
  63      We just check for a null pointer. */
  64
  65   if (infop == NULL)
  66     {
  67       __set_errno (EFAULT);
  68       return -1;
  69     }
  70
  71   cancel_oldtype = LIBC_CANCEL_ASYNC();
  72 #if HURD_INTERFACE_VERSION >= 20201227
  73   err = __USEPORT_CANCEL (PROC, __proc_waitid (port, pid, options,
  74                                                &status, &sigcode,
  75                                                &ignored, &child));
  76   if (err == MIG_BAD_ID || err == EOPNOTSUPP)
  77 #endif
  78     err = __USEPORT_CANCEL (PROC, __proc_wait (port, pid, options,
  79                                                &status, &sigcode,
  80                                                &ignored, &child));
  81   LIBC_CANCEL_RESET (cancel_oldtype);
  82
  83   if (err == EAGAIN)
  84     {
  85       /* POSIX.1-2008, Technical Corrigendum 1 XSH/TC1-2008/0713 [153] states
  86          that if waitid returns because WNOHANG was specified and status is
  87          not available for any process specified by idtype and id, then the
  88          si_signo and si_pid members of the structure pointed to by infop
  89          shall be set to zero.  */
  90       infop->si_signo = 0;
  91       infop->si_code = 0;
  92       return 0;
  93     }
  94
  95   if (err != 0)
  96     return __hurd_fail (err);
  97
  98   /* Decode the status field and set infop members... */
  99   infop->si_signo = SIGCHLD;
 100   infop->si_pid = child;
 101   infop->si_errno = 0;
 102
 103   if (WIFEXITED (status))
 104     {
 105       infop->si_code = CLD_EXITED;
 106       infop->si_status = WEXITSTATUS (status);
 107     }
 108   else if (WIFSIGNALED (status))
 109     {
 110       infop->si_code = WCOREDUMP (status) ? CLD_DUMPED : CLD_KILLED;
 111       infop->si_status = WTERMSIG (status);
 112     }
 113   else if (WIFSTOPPED (status))
 114     {
 115       infop->si_code = CLD_STOPPED;
 116       infop->si_status = WSTOPSIG (status);
 117     }
 118   else if (WIFCONTINUED (status))
 119     {
 120       infop->si_code = CLD_CONTINUED;
 121       infop->si_status = SIGCONT;
 122     }
 123
 124   return 0;
 125 }
 126 weak_alias (__waitid, waitid)
 127 strong_alias (__waitid, __libc_waitid)