1 /* Copyright (C) 1993-2021 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 #include <string.h>
23
24 int
__getgroups(int n,gid_t * gidset)25 __getgroups (int n, gid_t *gidset)
26 {
27 error_t err;
28 int ngids;
29 void *crit;
30
31 if (n < 0)
32 return __hurd_fail (EINVAL);
33
34 retry:
35 crit = _hurd_critical_section_lock ();
36 __mutex_lock (&_hurd_id.lock);
37
38 if (err = _hurd_check_ids ())
39 {
40 __mutex_unlock (&_hurd_id.lock);
41 _hurd_critical_section_unlock (crit);
42 if (err == EINTR)
43 /* Got a signal while inside an RPC of the critical section, retry again */
44 goto retry;
45 return __hurd_fail (err);
46 }
47
48 ngids = _hurd_id.gen.ngids;
49
50 if (n != 0)
51 {
52 /* Copy the gids onto stack storage and then release the idlock. */
53 gid_t gids[ngids];
54 memcpy (gids, _hurd_id.gen.gids, sizeof (gids));
55 __mutex_unlock (&_hurd_id.lock);
56 _hurd_critical_section_unlock (crit);
57
58 /* Now that the lock is released, we can safely copy the
59 group set into the user's array, which might fault. */
60 if (ngids > n)
61 return __hurd_fail (EINVAL);
62 memcpy (gidset, gids, ngids * sizeof (gid_t));
63 }
64 else
65 {
66 __mutex_unlock (&_hurd_id.lock);
67 _hurd_critical_section_unlock (crit);
68 }
69
70 return ngids;
71 }
72
73 weak_alias (__getgroups, getgroups)
74