1 | // |
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2 | // Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo |
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3 | // |
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4 | // The contents of this file are covered under the licence agreement in the |
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5 | // file "LICENCE" distributed with Cforall. |
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6 | // |
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7 | // interpose.c -- |
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8 | // |
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9 | // Author : Thierry Delisle |
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10 | // Created On : Wed Mar 29 16:10:31 2017 |
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11 | // Last Modified By : Peter A. Buhr |
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12 | // Last Modified On : Sat May 5 11:37:35 2018 |
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13 | // Update Count : 111 |
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14 | // |
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15 | |
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16 | #include <stdarg.h> // va_start, va_end |
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17 | #include <string.h> // strlen |
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18 | #include <unistd.h> // _exit, getpid |
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19 | #define __USE_GNU |
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20 | #include <signal.h> |
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21 | #undef __USE_GNU |
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22 | extern "C" { |
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23 | #include <dlfcn.h> // dlopen, dlsym |
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24 | #include <execinfo.h> // backtrace, messages |
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25 | } |
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26 | |
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27 | #include "bits/debug.h" |
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28 | #include "bits/defs.h" |
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29 | #include "bits/signal.h" // sigHandler_? |
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30 | #include "startup.h" // STARTUP_PRIORITY_CORE |
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31 | |
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32 | //============================================================================================= |
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33 | // Interposing helpers |
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34 | //============================================================================================= |
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35 | |
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36 | void preload_libgcc(void) { |
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37 | dlopen( "libgcc_s.so.1", RTLD_NOW ); |
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38 | if ( const char * error = dlerror() ) abort( "interpose_symbol : internal error pre-loading libgcc, %s\n", error ); |
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39 | } |
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40 | |
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41 | typedef void (* generic_fptr_t)(void); |
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42 | generic_fptr_t interpose_symbol( const char * symbol, const char * version ) { |
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43 | const char * error; |
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44 | |
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45 | static void * library; |
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46 | if ( ! library ) { |
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47 | #if defined( RTLD_NEXT ) |
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48 | library = RTLD_NEXT; |
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49 | #else |
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50 | // missing RTLD_NEXT => must hard-code library name, assuming libstdc++ |
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51 | library = dlopen( "libc.so.6", RTLD_LAZY ); |
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52 | error = dlerror(); |
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53 | if ( error ) { |
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54 | abort( "interpose_symbol : failed to open libc, %s\n", error ); |
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55 | } |
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56 | #endif |
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57 | } // if |
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58 | |
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59 | union { generic_fptr_t fptr; void * ptr; } originalFunc; |
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60 | |
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61 | #if defined( _GNU_SOURCE ) |
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62 | if ( version ) { |
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63 | originalFunc.ptr = dlvsym( library, symbol, version ); |
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64 | } else { |
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65 | originalFunc.ptr = dlsym( library, symbol ); |
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66 | } |
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67 | #else |
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68 | originalFunc.ptr = dlsym( library, symbol ); |
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69 | #endif // _GNU_SOURCE |
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70 | |
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71 | error = dlerror(); |
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72 | if ( error ) abort( "interpose_symbol : internal error, %s\n", error ); |
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73 | |
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74 | return originalFunc.fptr; |
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75 | } |
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76 | |
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77 | #define INTERPOSE_LIBC( x, ver ) __cabi_libc.x = (typeof(__cabi_libc.x))interpose_symbol( #x, ver ) |
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78 | |
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79 | //============================================================================================= |
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80 | // Interposition Startup logic |
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81 | //============================================================================================= |
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82 | |
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83 | void sigHandler_segv ( __CFA_SIGPARMS__ ); |
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84 | void sigHandler_ill ( __CFA_SIGPARMS__ ); |
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85 | void sigHandler_fpe ( __CFA_SIGPARMS__ ); |
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86 | void sigHandler_abort( __CFA_SIGPARMS__ ); |
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87 | void sigHandler_term ( __CFA_SIGPARMS__ ); |
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88 | |
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89 | struct { |
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90 | void (* exit)( int ) __attribute__(( __noreturn__ )); |
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91 | void (* abort)( void ) __attribute__(( __noreturn__ )); |
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92 | } __cabi_libc; |
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93 | |
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94 | extern "C" { |
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95 | void __cfaabi_interpose_startup(void) __attribute__(( constructor( STARTUP_PRIORITY_CORE ) )); |
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96 | void __cfaabi_interpose_startup( void ) { |
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97 | const char *version = NULL; |
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98 | |
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99 | preload_libgcc(); |
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100 | |
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101 | #pragma GCC diagnostic push |
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102 | #pragma GCC diagnostic ignored "-Wdiscarded-qualifiers" |
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103 | INTERPOSE_LIBC( abort, version ); |
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104 | INTERPOSE_LIBC( exit , version ); |
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105 | #pragma GCC diagnostic pop |
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106 | |
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107 | // Failure handler |
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108 | __cfaabi_sigaction( SIGSEGV, sigHandler_segv , SA_SIGINFO ); |
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109 | __cfaabi_sigaction( SIGBUS , sigHandler_segv , SA_SIGINFO ); |
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110 | __cfaabi_sigaction( SIGILL , sigHandler_ill , SA_SIGINFO ); |
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111 | __cfaabi_sigaction( SIGFPE , sigHandler_fpe , SA_SIGINFO ); |
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112 | __cfaabi_sigaction( SIGABRT, sigHandler_abort, SA_SIGINFO | SA_RESETHAND); |
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113 | __cfaabi_sigaction( SIGTERM, sigHandler_term , SA_SIGINFO ); |
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114 | __cfaabi_sigaction( SIGINT , sigHandler_term , SA_SIGINFO ); |
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115 | } |
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116 | } |
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117 | |
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118 | //============================================================================================= |
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119 | // Terminating Signals logic |
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120 | //============================================================================================= |
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121 | |
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122 | // Forward declare abort after the __typeof__ call to avoid ambiguities |
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123 | void exit( int status, const char fmt[], ... ) __attribute__(( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ )); |
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124 | void abort( const char fmt[], ... ) __attribute__(( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )); |
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125 | |
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126 | extern "C" { |
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127 | void abort( void ) __attribute__(( __nothrow__, __leaf__, __noreturn__ )) { |
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128 | abort( NULL ); |
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129 | } |
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130 | |
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131 | void __cabi_abort( const char fmt[], ... ) __attribute__(( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )) { |
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132 | va_list argp; |
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133 | va_start( argp, fmt ); |
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134 | abort( fmt, argp ); |
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135 | va_end( argp ); |
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136 | } |
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137 | |
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138 | void exit( int status ) __attribute__(( __nothrow__, __leaf__, __noreturn__ )) { |
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139 | __cabi_libc.exit( status ); |
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140 | } |
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141 | } |
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142 | |
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143 | void * kernel_abort ( void ) __attribute__(( __nothrow__, __leaf__, __weak__ )) { return NULL; } |
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144 | void kernel_abort_msg( void * data, char * buffer, int size ) __attribute__(( __nothrow__, __leaf__, __weak__ )) {} |
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145 | int kernel_abort_lastframe( void ) __attribute__(( __nothrow__, __leaf__, __weak__ )) { return 4; } |
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146 | |
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147 | enum { abort_text_size = 1024 }; |
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148 | static char abort_text[ abort_text_size ]; |
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149 | static int abort_lastframe; |
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150 | |
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151 | void exit( int status, const char fmt[], ... ) __attribute__(( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ )) { |
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152 | va_list args; |
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153 | va_start( args, fmt ); |
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154 | vfprintf( stderr, fmt, args ); |
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155 | va_end( args ); |
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156 | __cabi_libc.exit( status ); |
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157 | } |
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158 | |
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159 | void abort( const char fmt[], ... ) __attribute__(( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )) { |
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160 | void * kernel_data = kernel_abort(); // must be done here to lock down kernel |
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161 | int len; |
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162 | |
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163 | abort_lastframe = kernel_abort_lastframe(); |
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164 | len = snprintf( abort_text, abort_text_size, "Cforall Runtime error (UNIX pid:%ld) ", (long int)getpid() ); // use UNIX pid (versus getPid) |
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165 | __cfaabi_dbg_bits_write( abort_text, len ); |
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166 | |
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167 | if ( fmt ) { |
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168 | va_list args; |
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169 | va_start( args, fmt ); |
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170 | |
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171 | len = vsnprintf( abort_text, abort_text_size, fmt, args ); |
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172 | va_end( args ); |
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173 | __cfaabi_dbg_bits_write( abort_text, len ); |
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174 | |
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175 | if ( fmt[strlen( fmt ) - 1] != '\n' ) { // add optional newline if missing at the end of the format text |
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176 | __cfaabi_dbg_bits_write( "\n", 1 ); |
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177 | } |
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178 | } |
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179 | |
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180 | kernel_abort_msg( kernel_data, abort_text, abort_text_size ); |
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181 | __cabi_libc.abort(); |
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182 | } |
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183 | |
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184 | static void __cfaabi_backtrace() { |
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185 | enum { |
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186 | Frames = 50, // maximum number of stack frames |
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187 | Start = 8, // skip first N stack frames |
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188 | }; |
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189 | |
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190 | void * array[Frames]; |
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191 | size_t size = backtrace( array, Frames ); |
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192 | char ** messages = backtrace_symbols( array, size ); |
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193 | |
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194 | // find executable name |
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195 | *index( messages[0], '(' ) = '\0'; |
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196 | __cfaabi_dbg_bits_print_nolock( "Stack back trace for: %s\n", messages[0]); |
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197 | |
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198 | for ( int i = Start; i < size - abort_lastframe && messages != NULL; i += 1 ) { |
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199 | char * name = NULL, * offset_begin = NULL, * offset_end = NULL; |
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200 | |
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201 | for ( char * p = messages[i]; *p; ++p ) { |
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202 | //__cfaabi_dbg_bits_print_nolock( "X %s\n", p); |
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203 | // find parantheses and +offset |
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204 | if ( *p == '(' ) { |
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205 | name = p; |
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206 | } |
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207 | else if ( *p == '+' ) { |
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208 | offset_begin = p; |
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209 | } |
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210 | else if ( *p == ')' ) { |
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211 | offset_end = p; |
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212 | break; |
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213 | } |
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214 | } |
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215 | |
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216 | // if line contains symbol print it |
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217 | int frameNo = i - Start; |
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218 | if ( name && offset_begin && offset_end && name < offset_begin ) { |
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219 | // delimit strings |
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220 | *name++ = '\0'; |
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221 | *offset_begin++ = '\0'; |
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222 | *offset_end++ = '\0'; |
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223 | |
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224 | __cfaabi_dbg_bits_print_nolock( "(%i) %s : %s + %s %s\n", frameNo, messages[i], name, offset_begin, offset_end); |
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225 | } |
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226 | // otherwise, print the whole line |
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227 | else { |
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228 | __cfaabi_dbg_bits_print_nolock( "(%i) %s\n", frameNo, messages[i] ); |
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229 | } |
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230 | } |
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231 | free( messages ); |
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232 | } |
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233 | |
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234 | void sigHandler_segv( __CFA_SIGPARMS__ ) { |
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235 | abort( "Addressing invalid memory at location %p\n" |
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236 | "Possible cause is reading outside the address space or writing to a protected area within the address space with an invalid pointer or subscript.\n", |
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237 | sfp->si_addr ); |
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238 | } |
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239 | |
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240 | void sigHandler_ill( __CFA_SIGPARMS__ ) { |
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241 | abort( "Executing illegal instruction at location %p.\n" |
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242 | "Possible cause is stack corruption.\n", |
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243 | sfp->si_addr ); |
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244 | } |
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245 | |
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246 | void sigHandler_fpe( __CFA_SIGPARMS__ ) { |
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247 | const char * msg; |
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248 | |
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249 | choose( sfp->si_code ) { |
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250 | case FPE_INTDIV, FPE_FLTDIV: msg = "divide by zero"; |
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251 | case FPE_FLTOVF: msg = "overflow"; |
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252 | case FPE_FLTUND: msg = "underflow"; |
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253 | case FPE_FLTRES: msg = "inexact result"; |
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254 | case FPE_FLTINV: msg = "invalid operation"; |
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255 | default: msg = "unknown"; |
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256 | } // choose |
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257 | abort( "Computation error %s at location %p.\n", msg, sfp->si_addr ); |
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258 | } |
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259 | |
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260 | void sigHandler_abort( __CFA_SIGPARMS__ ) { |
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261 | __cfaabi_backtrace(); |
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262 | |
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263 | // reset default signal handler |
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264 | __cfaabi_sigdefault( SIGABRT ); |
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265 | |
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266 | raise( SIGABRT ); |
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267 | } |
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268 | |
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269 | void sigHandler_term( __CFA_SIGPARMS__ ) { |
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270 | abort( "Application stopped by %s signal.", sig == SIGINT ? "an interrupt (SIGINT)" : "a terminate (SIGTERM)" ); |
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271 | } |
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272 | |
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273 | // Local Variables: // |
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274 | // mode: c // |
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275 | // tab-width: 4 // |
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276 | // End: // |
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