1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * William Jolitz. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * $OpenBSD: SYS.h,v 1.28 2023/12/10 16:45:51 deraadt Exp $ 33 */ 34 35 #include "DEFS.h" 36 #include <sys/syscall.h> 37 38 #define TCB_OFFSET_ERRNO 16 39 40 /* 41 * Design note: 42 * 43 * System calls entry points are really named _thread_sys_{syscall}, 44 * and weakly aliased to the name {syscall}. This allows the thread 45 * library to replace system calls at link time. 46 */ 47 48 /* Use both _thread_sys_{syscall} and [weak] {syscall}. */ 49 50 #define SYSENTRY(x) \ 51 ENTRY(_thread_sys_##x); \ 52 WEAK_ALIAS(x, _thread_sys_##x) 53 #define SYSENTRY_HIDDEN(x) \ 54 ENTRY(_thread_sys_ ## x) 55 #define __END_HIDDEN(x) END(_thread_sys_ ## x); \ 56 _HIDDEN_FALIAS(x,_thread_sys_ ## x); \ 57 END(_HIDDEN(x)) 58 #define __END(x) __END_HIDDEN(x); END(x) 59 60 #define __DO_SYSCALL(x) \ 61 movl $(SYS_ ## x),%eax; \ 62 97: int $0x80; \ 63 PINSYSCALL(SYS_ ## x, 97b) 64 65 66 #define SET_ERRNO() \ 67 movl %eax,%gs:(TCB_OFFSET_ERRNO); \ 68 movl $-1, %eax; \ 69 movl $-1, %edx /* for lseek */ 70 #define HANDLE_ERRNO() \ 71 jnc 99f; \ 72 SET_ERRNO(); \ 73 99: 74 75 /* perform a syscall */ 76 #define _SYSCALL_NOERROR(x,y) \ 77 SYSENTRY(x); \ 78 __DO_SYSCALL(y); 79 #define _SYSCALL_HIDDEN_NOERROR(x,y) \ 80 SYSENTRY_HIDDEN(x); \ 81 __DO_SYSCALL(y); 82 83 #define SYSCALL_NOERROR(x) \ 84 _SYSCALL_NOERROR(x,x) 85 86 /* perform a syscall, set errno */ 87 #define _SYSCALL(x,y) \ 88 .text; \ 89 .align 2; \ 90 _SYSCALL_NOERROR(x,y) \ 91 HANDLE_ERRNO() 92 #define _SYSCALL_HIDDEN(x,y) \ 93 .text; \ 94 .align 2; \ 95 _SYSCALL_HIDDEN_NOERROR(x,y) \ 96 HANDLE_ERRNO() 97 98 #define SYSCALL(x) \ 99 _SYSCALL(x,x) 100 #define SYSCALL_HIDDEN(x) \ 101 _SYSCALL_HIDDEN(x,y) 102 103 /* perform a syscall, return */ 104 #define PSEUDO_NOERROR(x,y) \ 105 _SYSCALL_NOERROR(x,y); \ 106 ret; \ 107 __END(x) 108 109 /* perform a syscall, set errno, return */ 110 #define PSEUDO(x,y) \ 111 _SYSCALL(x,y); \ 112 ret; \ 113 __END(x) 114 #define PSEUDO_HIDDEN(x,y) \ 115 _SYSCALL_HIDDEN(x,y); \ 116 ret; \ 117 __END_HIDDEN(x) 118 119 /* perform a syscall with the same name, set errno, return */ 120 #define RSYSCALL(x) \ 121 PSEUDO(x,x); 122 #define RSYSCALL_HIDDEN(x) \ 123 PSEUDO_HIDDEN(x,x) 124 #define SYSCALL_END(x) __END(x) 125 #define SYSCALL_END_HIDDEN(x) \ 126 __END_HIDDEN(x) 127