root / prex-0.9.0 / usr / lib / posix / signal / __exception.c @ 03e9c04a
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1 | 03e9c04a | Brad Neuman | /*
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2 | * Copyright (c) 2005-2009, Kohsuke Ohtani
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3 | * All rights reserved.
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4 | *
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5 | * Redistribution and use in source and binary forms, with or without
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6 | * modification, are permitted provided that the following conditions
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7 | * are met:
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8 | * 1. Redistributions of source code must retain the above copyright
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9 | * notice, this list of conditions and the following disclaimer.
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10 | * 2. Redistributions in binary form must reproduce the above copyright
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11 | * notice, this list of conditions and the following disclaimer in the
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12 | * documentation and/or other materials provided with the distribution.
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13 | * 3. Neither the name of the author nor the names of any co-contributors
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14 | * may be used to endorse or promote products derived from this software
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15 | * without specific prior written permission.
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16 | *
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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27 | * SUCH DAMAGE.
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28 | */
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29 | |||
30 | #include <sys/prex.h> |
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31 | #include <sys/signal.h> |
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32 | |||
33 | #include <unistd.h> |
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34 | #include <signal.h> |
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35 | #include <stdlib.h> |
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36 | |||
37 | void __exception_init(void); |
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38 | void __exception_exit(int *); |
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39 | |||
40 | static int __sig_exit; |
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41 | |||
42 | struct sigaction __sig_act[NSIG];
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43 | sigset_t __sig_mask; |
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44 | sigset_t __sig_pending; |
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45 | |||
46 | #ifdef _REENTRANT
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47 | volatile mutex_t __sig_lock;
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48 | #endif
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49 | |||
50 | /*
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51 | * Process all pending and unmasked signal
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52 | *
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53 | * return 0 if at least one pending signal was processed.
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54 | * return -1 if no signal was processed.
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55 | */
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56 | int
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57 | __sig_flush(void)
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58 | { |
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59 | int sig;
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60 | sigset_t active, org_mask; |
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61 | struct sigaction action;
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62 | struct siginfo si;
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63 | int rc = -1; |
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64 | |||
65 | sig = 1;
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66 | for (;;) {
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67 | SIGNAL_LOCK(); |
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68 | active = __sig_pending & ~__sig_mask; |
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69 | action = __sig_act[sig]; |
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70 | SIGNAL_UNLOCK(); |
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71 | |||
72 | if (active == 0) |
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73 | break;
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74 | if (active & sigmask(sig)) {
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75 | |||
76 | SIGNAL_LOCK(); |
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77 | org_mask = __sig_mask; |
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78 | __sig_mask |= action.sa_mask; |
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79 | SIGNAL_UNLOCK(); |
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80 | |||
81 | if (action.sa_handler == SIG_DFL) {
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82 | /* Default */
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83 | switch (sig) {
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84 | case SIGCHLD:
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85 | case SIGTSTP:
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86 | /* XXX: */
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87 | break;
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88 | default:
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89 | SIGNAL_LOCK(); |
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90 | __sig_pending &= ~sigmask(sig); |
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91 | __sig_mask = org_mask; |
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92 | __sig_exit = sig; |
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93 | SIGNAL_UNLOCK(); |
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94 | exit(0);
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95 | } |
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96 | } else if (action.sa_handler != SIG_IGN) { |
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97 | /* User defined */
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98 | if (action.sa_flags & SA_SIGINFO) {
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99 | si.si_signo = sig; |
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100 | si.si_code = 0;
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101 | si.si_value.sival_int = 0;
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102 | action.sa_sigaction(sig, &si, NULL);
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103 | } else {
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104 | action.sa_handler(sig); |
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105 | } |
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106 | } |
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107 | SIGNAL_LOCK(); |
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108 | __sig_pending &= ~sigmask(sig); |
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109 | __sig_mask = org_mask; |
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110 | SIGNAL_UNLOCK(); |
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111 | |||
112 | switch (sig) {
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113 | case SIGILL:
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114 | case SIGTRAP:
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115 | case SIGFPE:
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116 | case SIGSEGV:
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117 | for (;;); /* exception from kernel */ |
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118 | break;
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119 | } |
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120 | if (action.sa_handler != SIG_IGN)
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121 | rc = 0; /* Signal is processed */ |
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122 | } |
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123 | |||
124 | if (++sig >= NSIG)
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125 | sig = 1;
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126 | } |
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127 | return rc;
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128 | } |
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129 | |||
130 | /*
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131 | * Exception handler for signal emulation
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132 | */
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133 | static void |
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134 | __exception_handler(int excpt)
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135 | { |
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136 | |||
137 | if (excpt > 0 && excpt <= NSIG) { |
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138 | |||
139 | SIGNAL_LOCK(); |
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140 | |||
141 | if (__sig_act[excpt].sa_handler != SIG_IGN)
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142 | __sig_pending |= sigmask(excpt); |
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143 | |||
144 | SIGNAL_UNLOCK(); |
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145 | } |
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146 | __sig_flush(); |
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147 | exception_return(); |
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148 | } |
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149 | |||
150 | /*
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151 | * Initialize exception
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152 | */
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153 | void
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154 | __exception_init(void)
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155 | { |
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156 | int i;
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157 | |||
158 | #ifdef _REENTRANT
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159 | mutex_init(&__sig_lock); |
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160 | #endif
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161 | exception_setup(EXC_DFL); |
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162 | |||
163 | __sig_mask = 0;
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164 | __sig_pending = 0;
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165 | __sig_exit = 0;
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166 | |||
167 | for (i = 0; i < NSIG; i++) { |
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168 | __sig_act[i].sa_flags = 0;
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169 | __sig_act[i].sa_handler = SIG_DFL; |
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170 | } |
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171 | |||
172 | /* Install exception handler */
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173 | exception_setup(__exception_handler); |
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174 | } |
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175 | |||
176 | /*
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177 | * Clean up
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178 | */
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179 | void
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180 | __exception_exit(int *signo)
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181 | { |
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182 | |||
183 | #ifdef _REENTRANT
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184 | mutex_destroy(&__sig_lock); |
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185 | #endif
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186 | exception_setup(EXC_DFL); |
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187 | |||
188 | *signo = __sig_exit; |
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189 | __sig_exit = 0;
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190 | __sig_pending = 0;
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191 | } |