sysdeps/mach/hurd/getgid.c

   1 /* Copyright (C) 1993-2024 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 <unistd.h>
  20 #include <hurd.h>
  21 #include <hurd/id.h>
  22
  23 /* Get the real group ID of the calling process.  */
  24 gid_t
  25 __getgid (void)
  26 {
  27   error_t err;
  28   gid_t gid;
  29
  30 retry:
  31   HURD_CRITICAL_BEGIN;
  32   __mutex_lock (&_hurd_id.lock);
  33
  34   if (err = _hurd_check_ids ())
  35     gid = __hurd_fail (err);
  36   else if (_hurd_id.aux.ngids >= 1)
  37     gid = _hurd_id.aux.gids[0];
  38   else
  39     /* We do not even have a real gid.  */
  40     gid = __hurd_fail (EGRATUITOUS);
  41
  42   __mutex_unlock (&_hurd_id.lock);
  43   HURD_CRITICAL_END;
  44   if (gid == -1 && errno == EINTR)
  45     /* Got a signal while inside an RPC of the critical section, retry again */
  46     goto retry;
  47
  48   return gid;
  49 }
  50
  51 weak_alias (__getgid, getgid)