1/* Copyright (C) 1995-2020 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <sys/sem.h>
20#include <stdarg.h>
21#include <ipc_priv.h>
22#include <sysdep.h>
23#include <shlib-compat.h>
24#include <bits/types/struct_semid64_ds.h> /* For __semid64_ds. */
25#include <linux/posix_types.h> /* For __kernel_mode_t. */
26
27/* The struct used to issue the syscall. For architectures that assume
28 64-bit time as default (!__ASSUME_TIME64_SYSCALLS) the syscall will
29 split the resulting 64-bit sem_{o,c}time in two fields (sem_{o,c}time
30 and __sem_{o,c}time_high). */
31union semun
32{
33 int val; /* value for SETVAL */
34 struct semid_ds *buf; /* buffer for IPC_STAT & IPC_SET */
35 unsigned short int *array; /* array for GETALL & SETALL */
36 struct seminfo *__buf; /* buffer for IPC_INFO */
37};
38
39#if __IPC_TIME64 == 0
40# define semun64 semun
41typedef union semun semctl_arg_t;
42#else
43# include <struct_kernel_semid64_ds.h>
44
45union ksemun64
46{
47 int val;
48 struct kernel_semid64_ds *buf;
49 unsigned short int *array;
50 struct seminfo *__buf;
51};
52
53# if __TIMESIZE == 64
54# define semun64 semun
55# else
56/* The struct used when __semctl64 is called. */
57union semun64
58{
59 int val;
60 struct __semid64_ds *buf;
61 unsigned short int *array;
62 struct seminfo *__buf;
63};
64# endif
65
66static void
67semid64_to_ksemid64 (const struct __semid64_ds *semid64,
68 struct kernel_semid64_ds *ksemid)
69{
70 ksemid->sem_perm = semid64->sem_perm;
71 ksemid->sem_otime = semid64->sem_otime;
72 ksemid->sem_otime_high = semid64->sem_otime >> 32;
73 ksemid->sem_ctime = semid64->sem_ctime;
74 ksemid->sem_ctime_high = semid64->sem_ctime >> 32;
75 ksemid->sem_nsems = semid64->sem_nsems;
76}
77
78static void
79ksemid64_to_semid64 (const struct kernel_semid64_ds *ksemid,
80 struct __semid64_ds *semid64)
81{
82 semid64->sem_perm = ksemid->sem_perm;
83 semid64->sem_otime = ksemid->sem_otime
84 | ((__time64_t) ksemid->sem_otime_high << 32);
85 semid64->sem_ctime = ksemid->sem_ctime
86 | ((__time64_t) ksemid->sem_ctime_high << 32);
87 semid64->sem_nsems = ksemid->sem_nsems;
88}
89
90static union ksemun64
91semun64_to_ksemun64 (int cmd, union semun64 semun64,
92 struct kernel_semid64_ds *buf)
93{
94 union ksemun64 r = { 0 };
95 switch (cmd)
96 {
97 case SETVAL:
98 r.val = semun64.val;
99 break;
100 case GETALL:
101 case SETALL:
102 r.array = semun64.array;
103 break;
104 case SEM_STAT:
105 case IPC_STAT:
106 case IPC_SET:
107 r.buf = buf;
108 semid64_to_ksemid64 (semun64.buf, r.buf);
109 break;
110 case IPC_INFO:
111 case SEM_INFO:
112 r.__buf = semun64.__buf;
113 break;
114 }
115 return r;
116}
117
118typedef union ksemun64 semctl_arg_t;
119#endif
120
121static int
122semctl_syscall (int semid, int semnum, int cmd, semctl_arg_t arg)
123{
124#ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
125 return INLINE_SYSCALL_CALL (semctl, semid, semnum, cmd | __IPC_64,
126 arg.array);
127#else
128 return INLINE_SYSCALL_CALL (ipc, IPCOP_semctl, semid, semnum, cmd | __IPC_64,
129 SEMCTL_ARG_ADDRESS (arg));
130#endif
131}
132
133/* POSIX states ipc_perm mode should have type of mode_t. */
134_Static_assert (sizeof ((struct semid_ds){0}.sem_perm.mode)
135 == sizeof (mode_t),
136 "sizeof (msqid_ds.msg_perm.mode) != sizeof (mode_t)");
137
138int
139__semctl64 (int semid, int semnum, int cmd, ...)
140{
141 union semun64 arg64 = { 0 };
142 va_list ap;
143
144 /* Get the argument only if required. */
145 switch (cmd)
146 {
147 case SETVAL: /* arg.val */
148 case GETALL: /* arg.array */
149 case SETALL:
150 case IPC_STAT: /* arg.buf */
151 case IPC_SET:
152 case SEM_STAT:
153 case IPC_INFO: /* arg.__buf */
154 case SEM_INFO:
155 va_start (ap, cmd);
156 arg64 = va_arg (ap, union semun64);
157 va_end (ap);
158 break;
159 }
160
161#if __IPC_TIME64
162 struct kernel_semid64_ds ksemid;
163 union ksemun64 ksemun = semun64_to_ksemun64 (cmd, arg64, &ksemid);
164# ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
165 if (cmd == IPC_SET)
166 ksemid.sem_perm.mode *= 0x10000U;
167# endif
168 union ksemun64 arg = ksemun;
169#else
170 union semun arg = arg64;
171#endif
172
173 int ret = semctl_syscall (semid, semnum, cmd, arg);
174 if (ret < 0)
175 return ret;
176
177 switch (cmd)
178 {
179 case IPC_STAT:
180 case SEM_STAT:
181 case SEM_STAT_ANY:
182#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
183 arg.buf->sem_perm.mode >>= 16;
184#else
185 /* Old Linux kernel versions might not clear the mode padding. */
186 if (sizeof ((struct semid_ds){0}.sem_perm.mode)
187 != sizeof (__kernel_mode_t))
188 arg.buf->sem_perm.mode &= 0xFFFF;
189#endif
190
191#if __IPC_TIME64
192 ksemid64_to_semid64 (arg.buf, arg64.buf);
193#endif
194 }
195
196 return ret;
197}
198#if __TIMESIZE != 64
199libc_hidden_def (__semctl64)
200
201
202/* The 64-bit time_t semid_ds version might have a different layout and
203 internal field alignment. */
204
205static void
206semid_to_semid64 (struct __semid64_ds *ds64, const struct semid_ds *ds)
207{
208 ds64->sem_perm = ds->sem_perm;
209 ds64->sem_otime = ds->sem_otime
210 | ((__time64_t) ds->__sem_otime_high << 32);
211 ds64->sem_ctime = ds->sem_ctime
212 | ((__time64_t) ds->__sem_ctime_high << 32);
213 ds64->sem_nsems = ds->sem_nsems;
214}
215
216static void
217semid64_to_semid (struct semid_ds *ds, const struct __semid64_ds *ds64)
218{
219 ds->sem_perm = ds64->sem_perm;
220 ds->sem_otime = ds64->sem_otime;
221 ds->__sem_otime_high = 0;
222 ds->sem_ctime = ds64->sem_ctime;
223 ds->__sem_ctime_high = 0;
224 ds->sem_nsems = ds64->sem_nsems;
225}
226
227static union semun64
228semun_to_semun64 (int cmd, union semun semun, struct __semid64_ds *semid64)
229{
230 union semun64 r = { 0 };
231 switch (cmd)
232 {
233 case SETVAL:
234 r.val = semun.val;
235 break;
236 case GETALL:
237 case SETALL:
238 r.array = semun.array;
239 break;
240 case SEM_STAT:
241 case IPC_STAT:
242 case IPC_SET:
243 r.buf = semid64;
244 semid_to_semid64 (r.buf, semun.buf);
245 break;
246 case IPC_INFO:
247 case SEM_INFO:
248 r.__buf = semun.__buf;
249 break;
250 }
251 return r;
252}
253
254int
255__semctl (int semid, int semnum, int cmd, ...)
256{
257 union semun arg = { 0 };
258
259 va_list ap;
260
261 /* Get the argument only if required. */
262 switch (cmd)
263 {
264 case SETVAL: /* arg.val */
265 case GETALL: /* arg.array */
266 case SETALL:
267 case IPC_STAT: /* arg.buf */
268 case IPC_SET:
269 case SEM_STAT:
270 case IPC_INFO: /* arg.__buf */
271 case SEM_INFO:
272 va_start (ap, cmd);
273 arg = va_arg (ap, union semun);
274 va_end (ap);
275 break;
276 }
277
278 struct __semid64_ds semid64;
279 union semun64 arg64 = semun_to_semun64 (cmd, arg, &semid64);
280
281 int ret = __semctl64 (semid, semnum, cmd, arg64);
282 if (ret < 0)
283 return ret;
284
285 switch (cmd)
286 {
287 case IPC_STAT:
288 case SEM_STAT:
289 case SEM_STAT_ANY:
290 semid64_to_semid (arg.buf, arg64.buf);
291 }
292
293 return ret;
294}
295#endif
296
297#ifndef DEFAULT_VERSION
298# ifndef __ASSUME_SYSVIPC_BROKEN_MODE_T
299# define DEFAULT_VERSION GLIBC_2_2
300# else
301# define DEFAULT_VERSION GLIBC_2_31
302# endif
303#endif
304versioned_symbol (libc, __semctl, semctl, DEFAULT_VERSION);
305
306#if defined __ASSUME_SYSVIPC_BROKEN_MODE_T \
307 && SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_31)
308int
309attribute_compat_text_section
310__semctl_mode16 (int semid, int semnum, int cmd, ...)
311{
312 semctl_arg_t arg = { 0 };
313 va_list ap;
314
315 /* Get the argument only if required. */
316 switch (cmd)
317 {
318 case SETVAL: /* arg.val */
319 case GETALL: /* arg.array */
320 case SETALL:
321 case IPC_STAT: /* arg.buf */
322 case IPC_SET:
323 case SEM_STAT:
324 case IPC_INFO: /* arg.__buf */
325 case SEM_INFO:
326 va_start (ap, cmd);
327 arg = va_arg (ap, semctl_arg_t);
328 va_end (ap);
329 break;
330 }
331
332 return semctl_syscall (semid, semnum, cmd, arg);
333}
334compat_symbol (libc, __semctl_mode16, semctl, GLIBC_2_2);
335#endif
336
337#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
338/* Since semctl use a variadic argument for semid_ds there is not need to
339 define and tie the compatibility symbol to the old 'union semun'
340 definition. */
341int
342attribute_compat_text_section
343__old_semctl (int semid, int semnum, int cmd, ...)
344{
345 union semun arg = { 0 };
346 va_list ap;
347
348 /* Get the argument only if required. */
349 switch (cmd)
350 {
351 case SETVAL: /* arg.val */
352 case GETALL: /* arg.array */
353 case SETALL:
354 case IPC_STAT: /* arg.buf */
355 case IPC_SET:
356 case SEM_STAT:
357 case IPC_INFO: /* arg.__buf */
358 case SEM_INFO:
359 va_start (ap, cmd);
360 arg = va_arg (ap, union semun);
361 va_end (ap);
362 break;
363 }
364
365#if defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS \
366 && !defined __ASSUME_SYSVIPC_DEFAULT_IPC_64
367 /* For architectures that have wire-up semctl but also have __IPC_64 to a
368 value different than default (0x0) it means the compat symbol used the
369 __NR_ipc syscall. */
370 return INLINE_SYSCALL_CALL (semctl, semid, semnum, cmd, arg.array);
371# else
372 return INLINE_SYSCALL_CALL (ipc, IPCOP_semctl, semid, semnum, cmd,
373 SEMCTL_ARG_ADDRESS (arg));
374# endif
375}
376compat_symbol (libc, __old_semctl, semctl, GLIBC_2_0);
377#endif
378