about summary refs log tree commit diff
path: root/sysdeps/unix/sysv/linux/i386/shmctl.c
blob: ca25ff0c7a3d2a84767492c1f1ae6a08a1b8bff2 (plain) (blame)
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
/* Copyright (C) 1995, 1997, 1998, 2000 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 Library General Public License as
   published by the Free Software Foundation; either version 2 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
   Library General Public License for more details.

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

#include <errno.h>
#include <sys/shm.h>
#include <ipc_priv.h>

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

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

struct __old_shmid_ds
{
  struct __old_ipc_perm shm_perm;	/* operation permission struct */
  int shm_segsz;			/* size of segment in bytes */
  __time_t shm_atime;			/* time of last shmat() */
  __time_t shm_dtime;			/* time of last shmdt() */
  __time_t shm_ctime;			/* time of last change by shmctl() */
  __ipc_pid_t shm_cpid;			/* pid of creator */
  __ipc_pid_t shm_lpid;			/* pid of last shmop */
  unsigned short int shm_nattch;	/* number of current attaches */
  unsigned short int __shm_npages;	/* size of segment (pages) */
  unsigned long int *__shm_pages;	/* array of ptrs to frames -> SHMMAX */
  struct vm_area_struct *__attaches;	/* descriptors for attaches */
};

struct __old_shminfo
{
  int shmmax;
  int shmmin;
  int shmmni;
  int shmseg;
  int shmall;
};

#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

/* Provide operations to control over shared memory segments.  */
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
int __old_shmctl (int, int, struct __old_shmid_ds *);
#endif
int __new_shmctl (int, int, struct shmid_ds *);

#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
int
__old_shmctl (int shmid, int cmd, struct __old_shmid_ds *buf)
{
  return INLINE_SYSCALL (ipc, 5, IPCOP_shmctl, shmid, cmd, 0, buf);
}
compat_symbol (libc, __old_shmctl, shmctl, GLIBC_2_0);
#endif

int
__new_shmctl (int shmid, int cmd, struct shmid_ds *buf)
{
#if __ASSUME_32BITUIDS > 0
  return INLINE_SYSCALL (ipc, 5, IPCOP_shmctl, shmid, cmd | __IPC_64, 0, buf);
#else
  switch (cmd) {
    case SHM_STAT:
    case IPC_STAT:
    case IPC_SET:
# if __WORDSIZE != 32
    case IPC_INFO:
# endif
      break;
    default:
      return INLINE_SYSCALL (ipc, 5, IPCOP_shmctl, shmid, cmd, 0, buf);
  }

  {
    struct __old_shmid_ds old;
    int result;

# 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)
	  return INLINE_SYSCALL (ipc, 5, IPCOP_shmctl, shmid, cmd | __IPC_64,
				 0, buf);
      }
# endif

    if (cmd == IPC_SET)
      {
	old.shm_perm.uid = buf->shm_perm.uid;
	old.shm_perm.gid = buf->shm_perm.gid;
	old.shm_perm.mode = buf->shm_perm.mode;
	if (old.shm_perm.uid != buf->shm_perm.uid ||
	    old.shm_perm.gid != buf->shm_perm.gid)
	  {
	    __set_errno (EINVAL);
	    return -1;
	  }
      }
    result = INLINE_SYSCALL (ipc, 5, IPCOP_shmctl, shmid, cmd, 0, &old);
    if (result != -1 && (cmd == SHM_STAT || cmd == IPC_STAT))
      {
	memset(buf, 0, sizeof(*buf));
	buf->shm_perm.__key = old.shm_perm.__key;
	buf->shm_perm.uid = old.shm_perm.uid;
	buf->shm_perm.gid = old.shm_perm.gid;
	buf->shm_perm.cuid = old.shm_perm.cuid;
	buf->shm_perm.cgid = old.shm_perm.cgid;
	buf->shm_perm.mode = old.shm_perm.mode;
	buf->shm_perm.__seq = old.shm_perm.__seq;
	buf->shm_atime = old.shm_atime;
	buf->shm_dtime = old.shm_dtime;
	buf->shm_ctime = old.shm_ctime;
	buf->shm_segsz = old.shm_segsz;
	buf->shm_nattch = old.shm_nattch;
	buf->shm_cpid = old.shm_cpid;
	buf->shm_lpid = old.shm_lpid;
      }
# if __WORDSIZE != 32
    else if (result != -1 && cmd == IPC_INFO)
      {
	struct __old_shminfo *oldi = (struct __old_shminfo *)&old;
	struct shminfo *i = (struct shminfo *)buf;

	memset(i, 0, sizeof(*i));
	i->shmmax = oldi->shmmax;
	i->shmmin = oldi->shmmin;
	i->shmmni = oldi->shmmni;
	i->shmseg = oldi->shmseg;
	i->shmall = oldi->shmall;
      }
# endif
    return result;
  }
#endif
}

versioned_symbol (libc, __new_shmctl, shmctl, GLIBC_2_2);