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
_sigfpe_master(int sig,siginfo_t * siginfo,void * arg)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
_enable_sigfpe_master(void)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
_test_sigfpe_master(void)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
sigfpe(sigfpe_code_type code,sigfpe_handler_type hdl)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