about summary refs log tree commit diff
path: root/sysdeps/unix/sysv/linux/shmctl.c
blob: ea389354973edbe13533370eb7b766e9029fc965 (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
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
/* Copyright (C) 1995-2022 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   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, see
   <https://www.gnu.org/licenses/>.  */

#include <sys/shm.h>
#include <stdarg.h>
#include <ipc_priv.h>
#include <sysdep.h>
#include <shlib-compat.h>
#include <errno.h>
#include <linux/posix_types.h>  /* For __kernel_mode_t.  */

/* POSIX states ipc_perm mode should have type of mode_t.  */
_Static_assert (sizeof ((struct shmid_ds){0}.shm_perm.mode)
		== sizeof (mode_t),
		"sizeof (shmid_ds.shm_perm.mode) != sizeof (mode_t)");

#if __IPC_TIME64 == 0
typedef struct shmid_ds shmctl_arg_t;
#else
# include <struct_kernel_shmid64_ds.h>

static void
shmid64_to_kshmid64 (const struct __shmid64_ds *shmid64,
		     struct kernel_shmid64_ds *kshmid)
{
  kshmid->shm_perm       = shmid64->shm_perm;
  kshmid->shm_segsz      = shmid64->shm_segsz;
  kshmid->shm_atime      = shmid64->shm_atime;
  kshmid->shm_atime_high = shmid64->shm_atime >> 32;
  kshmid->shm_dtime      = shmid64->shm_dtime;
  kshmid->shm_dtime_high = shmid64->shm_dtime >> 32;
  kshmid->shm_ctime      = shmid64->shm_ctime;
  kshmid->shm_ctime_high = shmid64->shm_ctime >> 32;
  kshmid->shm_cpid       = shmid64->shm_cpid;
  kshmid->shm_lpid       = shmid64->shm_lpid;
  kshmid->shm_nattch     = shmid64->shm_nattch;
}

static void
kshmid64_to_shmid64 (const struct kernel_shmid64_ds *kshmid,
		     struct __shmid64_ds *shmid64)
{
  shmid64->shm_perm   = kshmid->shm_perm;
  shmid64->shm_segsz  = kshmid->shm_segsz;
  shmid64->shm_atime  = kshmid->shm_atime
		        | ((__time64_t) kshmid->shm_atime_high << 32);
  shmid64->shm_dtime  = kshmid->shm_dtime
		        | ((__time64_t) kshmid->shm_dtime_high << 32);
  shmid64->shm_ctime  = kshmid->shm_ctime
		        | ((__time64_t) kshmid->shm_ctime_high << 32);
  shmid64->shm_cpid   = kshmid->shm_cpid;
  shmid64->shm_lpid   = kshmid->shm_lpid;
  shmid64->shm_nattch = kshmid->shm_nattch;
}

typedef struct kernel_shmid64_ds shmctl_arg_t;
#endif

static int
shmctl_syscall (int shmid, int cmd, shmctl_arg_t *buf)
{
#ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
  return INLINE_SYSCALL_CALL (shmctl, shmid, cmd | __IPC_64, buf);
#else
  return INLINE_SYSCALL_CALL (ipc, IPCOP_shmctl, shmid, cmd | __IPC_64, 0,
			      buf);
#endif
}

/* Provide operations to control over shared memory segments.  */
int
__shmctl64 (int shmid, int cmd, struct __shmid64_ds *buf)
{
#if __IPC_TIME64
  struct kernel_shmid64_ds kshmid, *arg = NULL;
#else
  shmctl_arg_t *arg;
#endif

  switch (cmd)
    {
    case IPC_RMID:
    case SHM_LOCK:
    case SHM_UNLOCK:
      arg = NULL;
      break;

    case IPC_SET:
    case IPC_STAT:
    case SHM_STAT:
    case SHM_STAT_ANY:
#if __IPC_TIME64
      if (buf != NULL)
	{
	  shmid64_to_kshmid64 (buf, &kshmid);
	  arg = &kshmid;
	}
# ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
      if (cmd == IPC_SET)
        arg->shm_perm.mode *= 0x10000U;
# endif
#else
      arg = buf;
#endif
      break;

    case IPC_INFO:
    case SHM_INFO:
      /* This is a Linux extension where kernel expects either a
	 'struct shminfo' (IPC_INFO) or 'struct shm_info' (SHM_INFO).  */
      arg = (__typeof__ (arg)) buf;
      break;

    default:
      __set_errno (EINVAL);
      return -1;
    }


  int ret = shmctl_syscall (shmid, cmd, arg);
  if (ret < 0)
    return ret;

  switch (cmd)
    {
      case IPC_STAT:
      case SHM_STAT:
      case SHM_STAT_ANY:
#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
        arg->shm_perm.mode >>= 16;
#else
      /* Old Linux kernel versions might not clear the mode padding.  */
      if (sizeof ((struct shmid_ds){0}.shm_perm.mode)
	  != sizeof (__kernel_mode_t))
	arg->shm_perm.mode &= 0xFFFF;
#endif

#if __IPC_TIME64
      kshmid64_to_shmid64 (arg, buf);
#endif
    }

  return ret;
}
#if __TIMESIZE != 64
libc_hidden_def (__shmctl64)

static void
shmid_to_shmid64 (struct __shmid64_ds *shm64, const struct shmid_ds *shm)
{
  shm64->shm_perm   = shm->shm_perm;
  shm64->shm_segsz  = shm->shm_segsz;
  shm64->shm_atime  = shm->shm_atime
		      | ((__time64_t) shm->__shm_atime_high << 32);
  shm64->shm_dtime  = shm->shm_dtime
		      | ((__time64_t) shm->__shm_dtime_high << 32);
  shm64->shm_ctime  = shm->shm_ctime
		      | ((__time64_t) shm->__shm_ctime_high << 32);
  shm64->shm_cpid   = shm->shm_cpid;
  shm64->shm_lpid   = shm->shm_lpid;
  shm64->shm_nattch = shm->shm_nattch;
}

static void
shmid64_to_shmid (struct shmid_ds *shm, const struct __shmid64_ds *shm64)
{
  shm->shm_perm         = shm64->shm_perm;
  shm->shm_segsz        = shm64->shm_segsz;
  shm->shm_atime        = shm64->shm_atime;
  shm->__shm_atime_high = 0;
  shm->shm_dtime        = shm64->shm_dtime;
  shm->__shm_dtime_high = 0;
  shm->shm_ctime        = shm64->shm_ctime;
  shm->__shm_ctime_high = 0;
  shm->shm_cpid         = shm64->shm_cpid;
  shm->shm_lpid         = shm64->shm_lpid;
  shm->shm_nattch       = shm64->shm_nattch;
}

int
__shmctl (int shmid, int cmd, struct shmid_ds *buf)
{
  struct __shmid64_ds shmid64, *buf64 = NULL;
  if (buf != NULL)
    {
      /* This is a Linux extension where kernel expects either a
	 'struct shminfo' (IPC_INFO) or 'struct shm_info' (SHM_INFO).  */
      if (cmd == IPC_INFO || cmd == SHM_INFO)
	buf64 = (struct __shmid64_ds *) buf;
      else
	{
	  shmid_to_shmid64 (&shmid64, buf);
	  buf64 = &shmid64;
	}
    }

  int ret = __shmctl64 (shmid, cmd, buf64);
  if (ret < 0)
    return ret;

  switch (cmd)
    {
      case IPC_STAT:
      case SHM_STAT:
      case SHM_STAT_ANY:
	shmid64_to_shmid (buf, buf64);
    }

  return ret;
}
#endif

#ifndef DEFAULT_VERSION
# ifndef __ASSUME_SYSVIPC_BROKEN_MODE_T
#  define DEFAULT_VERSION GLIBC_2_2
# else
#  define DEFAULT_VERSION GLIBC_2_31
# endif
#endif

versioned_symbol (libc, __shmctl, shmctl, DEFAULT_VERSION);

#if defined __ASSUME_SYSVIPC_BROKEN_MODE_T \
    && SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_31)
int
attribute_compat_text_section
__shmctl_mode16 (int shmid, int cmd, struct shmid_ds *buf)
{
  return shmctl_syscall (shmid, cmd, (shmctl_arg_t *) buf);
}
compat_symbol (libc, __shmctl_mode16, shmctl, GLIBC_2_2);
#endif

#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
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 */
};

int
attribute_compat_text_section
__old_shmctl (int shmid, int cmd, struct __old_shmid_ds *buf)
{
#if defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS \
    && !defined __ASSUME_SYSVIPC_DEFAULT_IPC_64
  /* For architecture that have wire-up shmctl but also have __IPC_64 to a
     value different than default (0x0), it means the compat symbol used the
     __NR_ipc syscall.  */
  return INLINE_SYSCALL_CALL (shmctl, shmid, cmd, buf);
#else
  return INLINE_SYSCALL_CALL (ipc, IPCOP_shmctl, shmid, cmd, 0, buf);
#endif
}
compat_symbol (libc, __old_shmctl, shmctl, GLIBC_2_0);
#endif