summaryrefslogtreecommitdiff
path: root/sysdeps/unix/sysv/linux/i386/semctl.c
blob: 1693cd47c492a9513eac7901c742bca4ae577d14 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
/* Copyright (C) 1995,1997,1998,2000,2003,2004,2006
	Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <errno.h>
#include <stdarg.h>
#include <sys/sem.h>
#include <ipc_priv.h>

#include <sysdep.h>
#include <string.h>
#include <sys/syscall.h>

#include <kernel-features.h>
#include <shlib-compat.h>

struct __old_semid_ds
{
  struct __old_ipc_perm sem_perm;	/* operation permission struct */
  __time_t sem_otime;			/* last semop() time */
  __time_t sem_ctime;			/* last time changed by semctl() */
  struct sem *__sembase;		/* ptr to first semaphore in array */
  struct sem_queue *__sem_pending;	/* pending operations */
  struct sem_queue *__sem_pending_last; /* last pending operation */
  struct sem_undo *__undo;		/* ondo requests on this array */
  unsigned short int sem_nsems;		/* number of semaphores in set */
};

/* Define a `union semun' suitable for Linux here.  */
union semun
{
  int val;			/* value for SETVAL */
  struct semid_ds *buf;		/* buffer for IPC_STAT & IPC_SET */
  unsigned short int *array;	/* array for GETALL & SETALL */
  struct seminfo *__buf;	/* buffer for IPC_INFO */
  struct __old_semid_ds *__old_buf;
};

#include <bp-checks.h>
#include <bp-semctl.h>		/* definition of CHECK_SEMCTL needs union semum */

#ifdef __NR_getuid32
# if __ASSUME_32BITUIDS == 0
/* This variable is shared with all files that need to check for 32bit
   uids.  */
extern int __libc_missing_32bit_uids;
# endif
#endif

/* Return identifier for array of NSEMS semaphores associated with
   KEY.  */
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
int __old_semctl (int semid, int semnum, int cmd, ...);
#endif
int __new_semctl (int semid, int semnum, int cmd, ...);

#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
int
attribute_compat_text_section
__old_semctl (int semid, int semnum, int cmd, ...)
{
  union semun arg;
  va_list ap;

  va_start (ap, cmd);

  /* Get the argument.  */
  arg = va_arg (ap, union semun);

  va_end (ap);

  return INLINE_SYSCALL (ipc, 5, IPCOP_semctl, semid, semnum, cmd,
			 CHECK_SEMCTL (&arg, semid, cmd));
}
compat_symbol (libc, __old_semctl, semctl, GLIBC_2_0);
#endif

int
__new_semctl (int semid, int semnum, int cmd, ...)
{
  union semun arg;
  va_list ap;

  va_start (ap, cmd);

  /* Get the argument.  */
  arg = va_arg (ap, union semun);

  va_end (ap);

#if __ASSUME_32BITUIDS > 0
  return INLINE_SYSCALL (ipc, 5, IPCOP_semctl, semid, semnum, cmd | __IPC_64,
			 CHECK_SEMCTL (&arg, semid, cmd | __IPC_64));
#else
  switch (cmd) {
    case SEM_STAT:
    case IPC_STAT:
    case IPC_SET:
      break;
    default:
      return INLINE_SYSCALL (ipc, 5, IPCOP_semctl, semid, semnum, cmd,
			     CHECK_SEMCTL (&arg, semid, cmd));
  }

  {
    int result;
    struct __old_semid_ds old;
    struct semid_ds *buf;

#ifdef __NR_getuid32
    if (__libc_missing_32bit_uids <= 0)
      {
	if (__libc_missing_32bit_uids < 0)
	  {
	    int save_errno = errno;

	    /* Test presence of new IPC by testing for getuid32 syscall.  */
	    result = INLINE_SYSCALL (getuid32, 0);
	    if (result == -1 && errno == ENOSYS)
	      __libc_missing_32bit_uids = 1;
	    else
	      __libc_missing_32bit_uids = 0;
	    __set_errno(save_errno);
	  }
	if (__libc_missing_32bit_uids <= 0)
	  {
	    result = INLINE_SYSCALL (ipc, 5, IPCOP_semctl, semid, semnum, cmd | __IPC_64,
				     CHECK_SEMCTL (&arg, semid, cmd | __IPC_64));
	    return result;
	  }
      }
#endif

    buf = arg.buf;
    arg.__old_buf = &old;
    if (cmd == IPC_SET)
      {
	old.sem_perm.uid = buf->sem_perm.uid;
	old.sem_perm.gid = buf->sem_perm.gid;
	old.sem_perm.mode = buf->sem_perm.mode;
	if (old.sem_perm.uid != buf->sem_perm.uid ||
	    old.sem_perm.gid != buf->sem_perm.gid)
	  {
	    __set_errno (EINVAL);
	    return -1;
	  }
      }
    result = INLINE_SYSCALL (ipc, 5, IPCOP_semctl, semid, semnum, cmd,
			     CHECK_SEMCTL (&arg, semid, cmd));
    if (result != -1 && cmd != IPC_SET)
      {
	memset(buf, 0, sizeof(*buf));
	buf->sem_perm.__key = old.sem_perm.__key;
	buf->sem_perm.uid = old.sem_perm.uid;
	buf->sem_perm.gid = old.sem_perm.gid;
	buf->sem_perm.cuid = old.sem_perm.cuid;
	buf->sem_perm.cgid = old.sem_perm.cgid;
	buf->sem_perm.mode = old.sem_perm.mode;
	buf->sem_perm.__seq = old.sem_perm.__seq;
	buf->sem_otime = old.sem_otime;
	buf->sem_ctime = old.sem_ctime;
	buf->sem_nsems = old.sem_nsems;
      }
    return result;
  }
#endif
}

versioned_symbol (libc, __new_semctl, semctl, GLIBC_2_2);