1 /* $OpenBSD: setjmp.h,v 1.5 2005/12/13 00:35:22 millert Exp $ */ 2 /* $NetBSD: setjmp.h,v 1.11 1994/12/20 10:35:44 cgd Exp $ */ 3 4 /*- 5 * Copyright (c) 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * (c) UNIX System Laboratories, Inc. 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)setjmp.h 8.2 (Berkeley) 1/21/94 38 */ 39 40 #pragma once 41 42 /** 43 * @file setjmp.h 44 * @brief Non-local jumps. 45 */ 46 47 #include <sys/cdefs.h> 48 49 #if defined(__aarch64__) 50 /** 51 * The size in words of an arm64 jmp_buf. Room for callee-saved registers, 52 * including floating point, stack pointer and program counter, various 53 * internal implementation details, and leaving some free space. 54 * 55 * Coincidentally matches OpenBSD, though they also save/restore the 56 * floating point status register too. 57 */ 58 #define _JBLEN 32 59 #elif defined(__arm__) 60 /** The size in words of an arm32 jmp_buf. Inherited from OpenBSD. */ 61 #define _JBLEN 64 62 #elif defined(__i386__) 63 /** The size in words of an x86 jmp_buf. Inherited from OpenBSD. */ 64 #define _JBLEN 10 65 #elif defined(__riscv) 66 /** 67 * The size in words of a riscv64 jmp_buf. Room for callee-saved registers, 68 * including floating point, stack pointer and program counter, various 69 * internal implementation details, and leaving lots of free space. 70 * 71 * Deliberately very large given the uncertainty around the final form of 72 * hardware shadow stack, and the fact that x86-64 glibc needed to steal 73 * space from their enormous sigset_t (which we don't have) to be able to 74 * implement the CET shadow stack. 75 */ 76 #define _JBLEN 64 77 #elif defined(__x86_64__) 78 /** The size in words of an x86-64 jmp_buf. Inherited from OpenBSD. */ 79 #define _JBLEN 11 80 #endif 81 82 /** The type of the buffer used by sigsetjmp()/siglongjmp(). */ 83 typedef long sigjmp_buf[_JBLEN + 1]; 84 85 /** The type of the buffer used by setjmp()/longjmp(). */ 86 typedef long jmp_buf[_JBLEN]; 87 88 #undef _JBLEN 89 90 __BEGIN_DECLS 91 92 /** 93 * Equivalent to sigsetjmp() with the second argument 0, so that the signal 94 * mask is not saved. 95 */ 96 int _setjmp(jmp_buf __env) __returns_twice; 97 98 /** Equivalent to siglongjmp(). */ 99 __noreturn void _longjmp(jmp_buf __env, int __value); 100 101 /** 102 * Equivalent to sigsetjmp() with the second argument 1, so that the signal 103 * mask is saved. 104 */ 105 int setjmp(jmp_buf __env) __returns_twice; 106 107 /** C11 says setjmp() must be a macro, but Android already had a function. */ 108 #define setjmp(__env) setjmp(__env) 109 110 /** Equivalent to siglongjmp(). */ 111 __noreturn void longjmp(jmp_buf __env, int __value); 112 113 /** 114 * [sigsetjmp(3)](http://man7.org/linux/man-pages/man3/sigsetjmp.3.html) 115 * sets the target of a future siglongjmp() call, saving or not saving the 116 * current signal mask based on the second argument. 117 * 118 * Returns 0 when first called, and returns the value passed to siglongjmp() 119 * when returning here as a result of a siglongjmp() call. 120 */ 121 int sigsetjmp(sigjmp_buf __env, int __save_signal_mask) __returns_twice; 122 123 /** 124 * [siglongjmp(3)](http://man7.org/linux/man-pages/man3/siglongjmp.3.html) 125 * transfers control back to the site of the sigsetjmp() call that initialized 126 * the given jump buffer, returning the given value. 127 * 128 * Does not return. 129 */ 130 __noreturn void siglongjmp(sigjmp_buf __env, int __value); 131 132 __END_DECLS 133