1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* 28 * Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T 29 * All Rights Reserved 30 * 31 * Portions of this source code were derived from Berkeley 32 * 4.3 BSD under license from the regents of the University of 33 * California. 34 */ 35 36 /* Swap handler for SIGFPE codes. */ 37 38 #include "lint.h" 39 #include <mtlib.h> 40 #include <errno.h> 41 #include <signal.h> 42 #include <floatingpoint.h> 43 #include <sys/types.h> 44 #include <sys/ucontext.h> 45 #include <sys/siginfo.h> 46 #include <thread.h> 47 #include <synch.h> 48 #include <stdlib.h> 49 50 #ifndef FPE_INTDIV 51 #define FPE_INTDIV 1 /* integer divide by zero */ 52 #endif 53 #ifndef FPE_INTOVF 54 #define FPE_INTOVF 2 /* integer overflow */ 55 #endif 56 #ifndef FPE_FLTDIV 57 #define FPE_FLTDIV 3 /* [floating divide by zero] */ 58 #endif 59 #ifndef FPE_FLTOVF 60 #define FPE_FLTOVF 4 /* [floating overflow] */ 61 #endif 62 #ifndef FPE_FLTUND 63 #define FPE_FLTUND 5 /* [floating underflow] */ 64 #endif 65 #ifndef FPE_FLTRES 66 #define FPE_FLTRES 6 /* [floating inexact result] */ 67 #endif 68 #ifndef FPE_FLTINV 69 #define FPE_FLTINV 7 /* [floating invalid operation] */ 70 #endif 71 72 #if defined(__i386) || defined(__amd64) 73 74 #ifndef FPE_FLTSUB 75 #define FPE_FLTSUB 8 /* subscript out of range */ 76 #endif 77 #ifndef FPE_FLTDEN 78 #define FPE_FLTDEN 9 /* x86-specific: denormal operand */ 79 #endif 80 81 #define N_SIGFPE_CODE 10 82 83 #else 84 85 #define N_SIGFPE_CODE 8 86 87 #endif /* __i386 */ 88 89 /* Array of SIGFPE codes. */ 90 91 static const sigfpe_code_type sigfpe_codes[N_SIGFPE_CODE] = { 92 FPE_INTDIV, 93 FPE_INTOVF, 94 FPE_FLTDIV, 95 FPE_FLTOVF, 96 FPE_FLTUND, 97 FPE_FLTRES, 98 FPE_FLTINV, 99 #if defined(__i386) || defined(__amd64) 100 FPE_FLTSUB, 101 FPE_FLTDEN, 102 #endif 103 0 104 }; 105 106 /* Array of handlers. */ 107 108 static mutex_t sigfpe_lock = DEFAULTMUTEX; 109 110 sigfpe_handler_type ieee_handlers[N_IEEE_EXCEPTION]; 111 static sigfpe_handler_type sigfpe_handlers[N_SIGFPE_CODE]; 112 113 static int _sigfpe_master_enabled; 114 /* Originally zero, set to 1 by _enable_sigfpe_master. */ 115 116 #ifndef BADSIG 117 #define BADSIG (void (*)(void))-1 118 #endif 119 120 static void 121 _sigfpe_master(int sig, siginfo_t *siginfo, void *arg) 122 { 123 ucontext_t *ucontext = arg; 124 int i; 125 int code; 126 enum fp_exception_type exception; 127 128 lmutex_lock(&sigfpe_lock); 129 code = siginfo->si_code; 130 for (i = 0; (i < N_SIGFPE_CODE) && (code != sigfpe_codes[i]); i++) 131 continue; 132 /* Find index of handler. */ 133 if (i >= N_SIGFPE_CODE) 134 i = N_SIGFPE_CODE - 1; 135 switch ((intptr_t)sigfpe_handlers[i]) { 136 case ((intptr_t)(SIGFPE_DEFAULT)): 137 switch (code) { 138 case FPE_FLTINV: 139 exception = fp_invalid; 140 goto ieee; 141 case FPE_FLTRES: 142 exception = fp_inexact; 143 goto ieee; 144 case FPE_FLTDIV: 145 exception = fp_division; 146 goto ieee; 147 case FPE_FLTUND: 148 exception = fp_underflow; 149 goto ieee; 150 case FPE_FLTOVF: 151 exception = fp_overflow; 152 goto ieee; 153 default: /* The common default treatment is to abort. */ 154 break; 155 } 156 /* FALLTHROUGH */ 157 case ((intptr_t)(SIGFPE_ABORT)): 158 abort(); 159 break; 160 case ((intptr_t)(SIGFPE_IGNORE)): 161 lmutex_unlock(&sigfpe_lock); 162 return; 163 default: /* User-defined not SIGFPE_DEFAULT or SIGFPE_ABORT. */ 164 (sigfpe_handlers[i])(sig, siginfo, ucontext); 165 lmutex_unlock(&sigfpe_lock); 166 return; 167 } 168 ieee: 169 switch ((intptr_t)ieee_handlers[(int)exception]) { 170 case ((intptr_t)(SIGFPE_DEFAULT)): /* Error condition but ignore it. */ 171 case ((intptr_t)(SIGFPE_IGNORE)): /* Error condition but ignore it. */ 172 lmutex_unlock(&sigfpe_lock); 173 return; 174 case ((intptr_t)(SIGFPE_ABORT)): 175 abort(); 176 default: 177 (ieee_handlers[(int)exception])(sig, siginfo, ucontext); 178 lmutex_unlock(&sigfpe_lock); 179 return; 180 } 181 } 182 183 static int 184 _enable_sigfpe_master(void) 185 { 186 /* Enable the sigfpe master handler always. */ 187 struct sigaction newsigact, oldsigact; 188 189 newsigact.sa_sigaction = _sigfpe_master; 190 (void) sigemptyset(&newsigact.sa_mask); 191 newsigact.sa_flags = SA_SIGINFO; /* enhanced handler */ 192 _sigfpe_master_enabled = 1; 193 return (sigaction(SIGFPE, &newsigact, &oldsigact)); 194 } 195 196 static int 197 _test_sigfpe_master(void) 198 { 199 /* 200 * Enable the sigfpe master handler if it's never been enabled 201 * before. 202 */ 203 204 if (_sigfpe_master_enabled == 0) 205 return (_enable_sigfpe_master()); 206 else 207 return (_sigfpe_master_enabled); 208 } 209 210 sigfpe_handler_type 211 sigfpe(sigfpe_code_type code, sigfpe_handler_type hdl) 212 { 213 sigfpe_handler_type oldhdl; 214 int i; 215 216 lmutex_lock(&sigfpe_lock); 217 (void) _test_sigfpe_master(); 218 for (i = 0; (i < N_SIGFPE_CODE) && (code != sigfpe_codes[i]); i++) 219 continue; 220 /* Find index of handler. */ 221 if (i >= N_SIGFPE_CODE) { 222 errno = EINVAL; 223 lmutex_unlock(&sigfpe_lock); 224 /* Not 0 or SIGFPE code */ 225 return ((sigfpe_handler_type)BADSIG); 226 } 227 oldhdl = sigfpe_handlers[i]; 228 sigfpe_handlers[i] = hdl; 229 lmutex_unlock(&sigfpe_lock); 230 return (oldhdl); 231 } 232