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 #pragma ident "%Z%%M% %I% %E% SMI" 37 38 /* Swap handler for SIGFPE codes. */ 39 40 #include "lint.h" 41 #include <mtlib.h> 42 #include <errno.h> 43 #include <signal.h> 44 #include <floatingpoint.h> 45 #include <sys/types.h> 46 #include <sys/ucontext.h> 47 #include <sys/siginfo.h> 48 #include <thread.h> 49 #include <synch.h> 50 #include <stdlib.h> 51 52 #ifndef FPE_INTDIV 53 #define FPE_INTDIV 1 /* integer divide by zero */ 54 #endif 55 #ifndef FPE_INTOVF 56 #define FPE_INTOVF 2 /* integer overflow */ 57 #endif 58 #ifndef FPE_FLTDIV 59 #define FPE_FLTDIV 3 /* [floating divide by zero] */ 60 #endif 61 #ifndef FPE_FLTOVF 62 #define FPE_FLTOVF 4 /* [floating overflow] */ 63 #endif 64 #ifndef FPE_FLTUND 65 #define FPE_FLTUND 5 /* [floating underflow] */ 66 #endif 67 #ifndef FPE_FLTRES 68 #define FPE_FLTRES 6 /* [floating inexact result] */ 69 #endif 70 #ifndef FPE_FLTINV 71 #define FPE_FLTINV 7 /* [floating invalid operation] */ 72 #endif 73 74 #if defined(__i386) || defined(__amd64) 75 76 #ifndef FPE_FLTSUB 77 #define FPE_FLTSUB 8 /* subscript out of range */ 78 #endif 79 #ifndef FPE_FLTDEN 80 #define FPE_FLTDEN 9 /* x86-specific: denormal operand */ 81 #endif 82 83 #define N_SIGFPE_CODE 10 84 85 #else 86 87 #define N_SIGFPE_CODE 8 88 89 #endif /* __i386 */ 90 91 /* Array of SIGFPE codes. */ 92 93 static const sigfpe_code_type sigfpe_codes[N_SIGFPE_CODE] = { 94 FPE_INTDIV, 95 FPE_INTOVF, 96 FPE_FLTDIV, 97 FPE_FLTOVF, 98 FPE_FLTUND, 99 FPE_FLTRES, 100 FPE_FLTINV, 101 #if defined(__i386) || defined(__amd64) 102 FPE_FLTSUB, 103 FPE_FLTDEN, 104 #endif 105 0 106 }; 107 108 /* Array of handlers. */ 109 110 static mutex_t sigfpe_lock = DEFAULTMUTEX; 111 112 sigfpe_handler_type ieee_handlers[N_IEEE_EXCEPTION]; 113 static sigfpe_handler_type sigfpe_handlers[N_SIGFPE_CODE]; 114 115 static int _sigfpe_master_enabled; 116 /* Originally zero, set to 1 by _enable_sigfpe_master. */ 117 118 #ifndef BADSIG 119 #define BADSIG (void (*)(void))-1 120 #endif 121 122 static void 123 _sigfpe_master(int sig, siginfo_t *siginfo, void *arg) 124 { 125 ucontext_t *ucontext = arg; 126 int i; 127 int code; 128 enum fp_exception_type exception; 129 130 lmutex_lock(&sigfpe_lock); 131 code = siginfo->si_code; 132 for (i = 0; (i < N_SIGFPE_CODE) && (code != sigfpe_codes[i]); i++) 133 continue; 134 /* Find index of handler. */ 135 if (i >= N_SIGFPE_CODE) 136 i = N_SIGFPE_CODE - 1; 137 switch ((intptr_t)sigfpe_handlers[i]) { 138 case ((intptr_t)(SIGFPE_DEFAULT)): 139 switch (code) { 140 case FPE_FLTINV: 141 exception = fp_invalid; 142 goto ieee; 143 case FPE_FLTRES: 144 exception = fp_inexact; 145 goto ieee; 146 case FPE_FLTDIV: 147 exception = fp_division; 148 goto ieee; 149 case FPE_FLTUND: 150 exception = fp_underflow; 151 goto ieee; 152 case FPE_FLTOVF: 153 exception = fp_overflow; 154 goto ieee; 155 default: /* The common default treatment is to abort. */ 156 break; 157 } 158 case ((intptr_t)(SIGFPE_ABORT)): 159 abort(); 160 break; 161 case ((intptr_t)(SIGFPE_IGNORE)): 162 lmutex_unlock(&sigfpe_lock); 163 return; 164 default: /* User-defined not SIGFPE_DEFAULT or SIGFPE_ABORT. */ 165 (sigfpe_handlers[i])(sig, siginfo, ucontext); 166 lmutex_unlock(&sigfpe_lock); 167 return; 168 } 169 ieee: 170 switch ((intptr_t)ieee_handlers[(int)exception]) { 171 case ((intptr_t)(SIGFPE_DEFAULT)): /* Error condition but ignore it. */ 172 case ((intptr_t)(SIGFPE_IGNORE)): /* Error condition but ignore it. */ 173 lmutex_unlock(&sigfpe_lock); 174 return; 175 case ((intptr_t)(SIGFPE_ABORT)): 176 abort(); 177 default: 178 (ieee_handlers[(int)exception])(sig, siginfo, ucontext); 179 lmutex_unlock(&sigfpe_lock); 180 return; 181 } 182 } 183 184 static int 185 _enable_sigfpe_master(void) 186 { 187 /* Enable the sigfpe master handler always. */ 188 struct sigaction newsigact, oldsigact; 189 190 newsigact.sa_sigaction = _sigfpe_master; 191 (void) sigemptyset(&newsigact.sa_mask); 192 newsigact.sa_flags = SA_SIGINFO; /* enhanced handler */ 193 _sigfpe_master_enabled = 1; 194 return (sigaction(SIGFPE, &newsigact, &oldsigact)); 195 } 196 197 static int 198 _test_sigfpe_master(void) 199 { 200 /* 201 * Enable the sigfpe master handler if it's never been enabled 202 * before. 203 */ 204 205 if (_sigfpe_master_enabled == 0) 206 return (_enable_sigfpe_master()); 207 else 208 return (_sigfpe_master_enabled); 209 } 210 211 sigfpe_handler_type 212 sigfpe(sigfpe_code_type code, sigfpe_handler_type hdl) 213 { 214 sigfpe_handler_type oldhdl; 215 int i; 216 217 lmutex_lock(&sigfpe_lock); 218 (void) _test_sigfpe_master(); 219 for (i = 0; (i < N_SIGFPE_CODE) && (code != sigfpe_codes[i]); i++) 220 continue; 221 /* Find index of handler. */ 222 if (i >= N_SIGFPE_CODE) { 223 errno = EINVAL; 224 lmutex_unlock(&sigfpe_lock); 225 /* Not 0 or SIGFPE code */ 226 return ((sigfpe_handler_type)BADSIG); 227 } 228 oldhdl = sigfpe_handlers[i]; 229 sigfpe_handlers[i] = hdl; 230 lmutex_unlock(&sigfpe_lock); 231 return (oldhdl); 232 } 233