1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/sem.h>
30 
31 #include <stdarg.h>
32 #include <sys/syscall.h>
33 #include <unistd.h>
34 
semctl(int id,int num,int cmd,...)35 int semctl(int id, int num, int cmd, ...) {
36 #if !defined(__LP64__) || defined(__mips__)
37   // Annoyingly, the kernel requires this for 32-bit but rejects it for 64-bit.
38   // Mips64 is an exception to this, it requires the flag.
39   cmd |= IPC_64;
40 #endif
41   va_list ap;
42   va_start(ap, cmd);
43   semun arg = va_arg(ap, semun);
44   va_end(ap);
45 #if defined(SYS_semctl)
46   return syscall(SYS_semctl, id, num, cmd, arg);
47 #else
48   return syscall(SYS_ipc, SEMCTL, id, num, cmd, &arg, 0);
49 #endif
50 }
51 
semget(key_t key,int n,int flags)52 int semget(key_t key, int n, int flags) {
53 #if defined(SYS_semget)
54   return syscall(SYS_semget, key, n, flags);
55 #else
56   return syscall(SYS_ipc, SEMGET, key, n, flags, 0, 0);
57 #endif
58 }
59 
semop(int id,sembuf * ops,size_t op_count)60 int semop(int id, sembuf* ops, size_t op_count) {
61   return semtimedop(id, ops, op_count, nullptr);
62 }
63 
semtimedop(int id,sembuf * ops,size_t op_count,const timespec * ts)64 int semtimedop(int id, sembuf* ops, size_t op_count, const timespec* ts) {
65 #if defined(SYS_semtimedop)
66   return syscall(SYS_semtimedop, id, ops, op_count, ts);
67 #else
68   return syscall(SYS_ipc, SEMTIMEDOP, id, op_count, 0, ops, ts);
69 #endif
70 }
71