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/shm.h> 30 31 #include <sys/syscall.h> 32 #include <unistd.h> 33 34 void* shmat(int id, const void* address, int flags) { 35 #if defined(SYS_shmat) 36 return reinterpret_cast<void*>(syscall(SYS_shmat, id, address, flags)); 37 #else 38 // See the kernel's ipc/syscall.c for the other side of this dance. 39 void* result = nullptr; 40 if (syscall(SYS_ipc, SHMAT, id, flags, &result, address, 0) == -1) { 41 return reinterpret_cast<void*>(-1); 42 } 43 return result; 44 #endif 45 } 46 47 int shmctl(int id, int cmd, struct shmid_ds* buf) { 48 #if !defined(__LP64__) || defined(__mips__) 49 // Annoyingly, the kernel requires this for 32-bit but rejects it for 64-bit. 50 // Mips64 is an exception to this, it requires the flag. 51 cmd |= IPC_64; 52 #endif 53 #if defined(SYS_shmctl) 54 return syscall(SYS_shmctl, id, cmd, buf); 55 #else 56 return syscall(SYS_ipc, SHMCTL, id, cmd, 0, buf, 0); 57 #endif 58 } 59 60 int shmdt(const void* address) { 61 #if defined(SYS_shmdt) 62 return syscall(SYS_shmdt, address); 63 #else 64 return syscall(SYS_ipc, SHMDT, 0, 0, 0, address, 0); 65 #endif 66 } 67 68 int shmget(key_t key, size_t size, int flags) { 69 #if defined(SYS_shmget) 70 return syscall(SYS_shmget, key, size, flags); 71 #else 72 return syscall(SYS_ipc, SHMGET, key, size, flags, 0, 0); 73 #endif 74 } 75
