1/* Copyright (C) 1995-2021 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 <linux/posix_types.h> /* For __kernel_mode_t. */
25
26/* The struct used to issue the syscall. For architectures that assume
27 64-bit time as default (!__ASSUME_TIME64_SYSCALLS) the syscall will
28 split the resulting 64-bit sem_{o,c}time in two fields (sem_{o,c}time
29 and __sem_{o,c}time_high). */
30union semun
31{
32 int val; /* value for SETVAL */
33 struct semid_ds *buf; /* buffer for IPC_STAT & IPC_SET */
34 unsigned short int *array; /* array for GETALL & SETALL */
35 struct seminfo *__buf; /* buffer for IPC_INFO */
36};
37
38#if __IPC_TIME64 == 0
39# define semun64 semun
40typedef union semun semctl_arg_t;
41#else
42# include <struct_kernel_semid64_ds.h>
43
44union ksemun64
45{
46 int val;
47 struct kernel_semid64_ds *buf;
48 unsigned short int *array;
49 struct seminfo *__buf;
50};
51
52# if __TIMESIZE == 64
53# define semun64 semun
54# else
55/* The struct used when __semctl64 is called. */
56union semun64
57{
58 int val;
59 struct __semid64_ds *buf;
60 unsigned short int *array;
61 struct seminfo *__buf;
62};
63# endif
64
65static void
66semid64_to_ksemid64 (const struct __semid64_ds *semid64,
67 struct kernel_semid64_ds *ksemid)
68{
69 ksemid->sem_perm = semid64->sem_perm;
70 ksemid->sem_otime = semid64->sem_otime;
71 ksemid->sem_otime_high = semid64->sem_otime >> 32;
72 ksemid->sem_ctime = semid64->sem_ctime;
73 ksemid->sem_ctime_high = semid64->sem_ctime >> 32;
74 ksemid->sem_nsems = semid64->sem_nsems;
75}
76
77static void
78ksemid64_to_semid64 (const struct kernel_semid64_ds *ksemid,
79 struct __semid64_ds *semid64)
80{
81 semid64->sem_perm = ksemid->sem_perm;
82 semid64->sem_otime = ksemid->sem_otime
83 | ((__time64_t) ksemid->sem_otime_high << 32);
84 semid64->sem_ctime = ksemid->sem_ctime
85 | ((__time64_t) ksemid->sem_ctime_high << 32);
86 semid64->sem_nsems = ksemid->sem_nsems;
87}
88
89static union ksemun64
90semun64_to_ksemun64 (int cmd, union semun64 semun64,
91 struct kernel_semid64_ds *buf)
92{
93 union ksemun64 r = { 0 };
94 switch (cmd)
95 {
96 case SETVAL:
97 r.val = semun64.val;
98 break;
99 case GETALL:
100 case SETALL:
101 r.array = semun64.array;
102 break;
103 case SEM_STAT:
104 case SEM_STAT_ANY:
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 SEM_STAT_ANY:
154 case IPC_INFO: /* arg.__buf */
155 case SEM_INFO:
156 va_start (ap, cmd);
157 arg64 = va_arg (ap, union semun64);
158 va_end (ap);
159 break;
160 case IPC_RMID: /* arg ignored. */
161 case GETNCNT:
162 case GETPID:
163 case GETVAL:
164 case GETZCNT:
165 break;
166 default:
167 __set_errno (EINVAL);
168 return -1;
169 }
170
171#if __IPC_TIME64
172 struct kernel_semid64_ds ksemid;
173 union ksemun64 ksemun = semun64_to_ksemun64 (cmd, arg64, &ksemid);
174# ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
175 if (cmd == IPC_SET)
176 ksemid.sem_perm.mode *= 0x10000U;
177# endif
178 union ksemun64 arg = ksemun;
179#else
180 union semun arg = arg64;
181#endif
182
183 int ret = semctl_syscall (semid, semnum, cmd, arg);
184 if (ret < 0)
185 return ret;
186
187 switch (cmd)
188 {
189 case IPC_STAT:
190 case SEM_STAT:
191 case SEM_STAT_ANY:
192#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
193 arg.buf->sem_perm.mode >>= 16;
194#else
195 /* Old Linux kernel versions might not clear the mode padding. */
196 if (sizeof ((struct semid_ds){0}.sem_perm.mode)
197 != sizeof (__kernel_mode_t))
198 arg.buf->sem_perm.mode &= 0xFFFF;
199#endif
200
201#if __IPC_TIME64
202 ksemid64_to_semid64 (arg.buf, arg64.buf);
203#endif
204 }
205
206 return ret;
207}
208#if __TIMESIZE != 64
209libc_hidden_def (__semctl64)
210
211
212/* The 64-bit time_t semid_ds version might have a different layout and
213 internal field alignment. */
214
215static void
216semid_to_semid64 (struct __semid64_ds *ds64, const struct semid_ds *ds)
217{
218 ds64->sem_perm = ds->sem_perm;
219 ds64->sem_otime = ds->sem_otime
220 | ((__time64_t) ds->__sem_otime_high << 32);
221 ds64->sem_ctime = ds->sem_ctime
222 | ((__time64_t) ds->__sem_ctime_high << 32);
223 ds64->sem_nsems = ds->sem_nsems;
224}
225
226static void
227semid64_to_semid (struct semid_ds *ds, const struct __semid64_ds *ds64)
228{
229 ds->sem_perm = ds64->sem_perm;
230 ds->sem_otime = ds64->sem_otime;
231 ds->__sem_otime_high = 0;
232 ds->sem_ctime = ds64->sem_ctime;
233 ds->__sem_ctime_high = 0;
234 ds->sem_nsems = ds64->sem_nsems;
235}
236
237static union semun64
238semun_to_semun64 (int cmd, union semun semun, struct __semid64_ds *semid64)
239{
240 union semun64 r = { 0 };
241 switch (cmd)
242 {
243 case SETVAL:
244 r.val = semun.val;
245 break;
246 case GETALL:
247 case SETALL:
248 r.array = semun.array;
249 break;
250 case SEM_STAT:
251 case SEM_STAT_ANY:
252 case IPC_STAT:
253 case IPC_SET:
254 r.buf = semid64;
255 semid_to_semid64 (r.buf, semun.buf);
256 break;
257 case IPC_INFO:
258 case SEM_INFO:
259 r.__buf = semun.__buf;
260 break;
261 }
262 return r;
263}
264
265int
266__semctl (int semid, int semnum, int cmd, ...)
267{
268 union semun arg = { 0 };
269
270 va_list ap;
271
272 /* Get the argument only if required. */
273 switch (cmd)
274 {
275 case SETVAL: /* arg.val */
276 case GETALL: /* arg.array */
277 case SETALL:
278 case IPC_STAT: /* arg.buf */
279 case IPC_SET:
280 case SEM_STAT:
281 case SEM_STAT_ANY:
282 case IPC_INFO: /* arg.__buf */
283 case SEM_INFO:
284 va_start (ap, cmd);
285 arg = va_arg (ap, union semun);
286 va_end (ap);
287 break;
288 /* __semctl64 handles non-supported commands. */
289 }
290
291 struct __semid64_ds semid64;
292 union semun64 arg64 = semun_to_semun64 (cmd, arg, &semid64);
293
294 int ret = __semctl64 (semid, semnum, cmd, arg64);
295 if (ret < 0)
296 return ret;
297
298 switch (cmd)
299 {
300 case IPC_STAT:
301 case SEM_STAT:
302 case SEM_STAT_ANY:
303 semid64_to_semid (arg.buf, arg64.buf);
304 }
305
306 return ret;
307}
308#endif
309
310#ifndef DEFAULT_VERSION
311# ifndef __ASSUME_SYSVIPC_BROKEN_MODE_T
312# define DEFAULT_VERSION GLIBC_2_2
313# else
314# define DEFAULT_VERSION GLIBC_2_31
315# endif
316#endif
317versioned_symbol (libc, __semctl, semctl, DEFAULT_VERSION);
318
319#if defined __ASSUME_SYSVIPC_BROKEN_MODE_T \
320 && SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_31)
321int
322attribute_compat_text_section
323__semctl_mode16 (int semid, int semnum, int cmd, ...)
324{
325 semctl_arg_t arg = { 0 };
326 va_list ap;
327
328 /* Get the argument only if required. */
329 switch (cmd)
330 {
331 case SETVAL: /* arg.val */
332 case GETALL: /* arg.array */
333 case SETALL:
334 case IPC_STAT: /* arg.buf */
335 case IPC_SET:
336 case SEM_STAT:
337 case SEM_STAT_ANY:
338 case IPC_INFO: /* arg.__buf */
339 case SEM_INFO:
340 va_start (ap, cmd);
341 arg = va_arg (ap, semctl_arg_t);
342 va_end (ap);
343 break;
344 }
345
346 return semctl_syscall (semid, semnum, cmd, arg);
347}
348compat_symbol (libc, __semctl_mode16, semctl, GLIBC_2_2);
349#endif
350
351#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
352/* Since semctl use a variadic argument for semid_ds there is not need to
353 define and tie the compatibility symbol to the old 'union semun'
354 definition. */
355int
356attribute_compat_text_section
357__old_semctl (int semid, int semnum, int cmd, ...)
358{
359 union semun arg = { 0 };
360 va_list ap;
361
362 /* Get the argument only if required. */
363 switch (cmd)
364 {
365 case SETVAL: /* arg.val */
366 case GETALL: /* arg.array */
367 case SETALL:
368 case IPC_STAT: /* arg.buf */
369 case IPC_SET:
370 case SEM_STAT:
371 case SEM_STAT_ANY:
372 case IPC_INFO: /* arg.__buf */
373 case SEM_INFO:
374 va_start (ap, cmd);
375 arg = va_arg (ap, union semun);
376 va_end (ap);
377 break;
378 }
379
380#if defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS \
381 && !defined __ASSUME_SYSVIPC_DEFAULT_IPC_64
382 /* For architectures that have wire-up semctl but also have __IPC_64 to a
383 value different than default (0x0) it means the compat symbol used the
384 __NR_ipc syscall. */
385 return INLINE_SYSCALL_CALL (semctl, semid, semnum, cmd, arg.array);
386# else
387 return INLINE_SYSCALL_CALL (ipc, IPCOP_semctl, semid, semnum, cmd,
388 SEMCTL_ARG_ADDRESS (arg));
389# endif
390}
391compat_symbol (libc, __old_semctl, semctl, GLIBC_2_0);
392#endif
393