111
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1 /* AddressSanitizer, a fast memory error detector.
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2 Copyright (C) 2012-2017 Free Software Foundation, Inc.
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3 Contributed by Kostya Serebryany <kcc@google.com>
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4
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5 This file is part of GCC.
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6
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7 GCC is free software; you can redistribute it and/or modify it under
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8 the terms of the GNU General Public License as published by the Free
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9 Software Foundation; either version 3, or (at your option) any later
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10 version.
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11
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12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
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14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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15 for more details.
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16
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17 You should have received a copy of the GNU General Public License
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18 along with GCC; see the file COPYING3. If not see
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19 <http://www.gnu.org/licenses/>. */
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20
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21
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22 #include "config.h"
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23 #include "system.h"
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24 #include "coretypes.h"
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25 #include "backend.h"
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26 #include "target.h"
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27 #include "rtl.h"
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28 #include "tree.h"
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29 #include "gimple.h"
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30 #include "cfghooks.h"
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31 #include "alloc-pool.h"
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32 #include "tree-pass.h"
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33 #include "memmodel.h"
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34 #include "tm_p.h"
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35 #include "ssa.h"
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36 #include "stringpool.h"
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37 #include "tree-ssanames.h"
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38 #include "optabs.h"
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39 #include "emit-rtl.h"
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40 #include "cgraph.h"
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41 #include "gimple-pretty-print.h"
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42 #include "alias.h"
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43 #include "fold-const.h"
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44 #include "cfganal.h"
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45 #include "gimplify.h"
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46 #include "gimple-iterator.h"
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47 #include "varasm.h"
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48 #include "stor-layout.h"
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49 #include "tree-iterator.h"
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50 #include "stringpool.h"
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51 #include "attribs.h"
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52 #include "asan.h"
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53 #include "dojump.h"
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54 #include "explow.h"
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55 #include "expr.h"
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56 #include "output.h"
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57 #include "langhooks.h"
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58 #include "cfgloop.h"
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59 #include "gimple-builder.h"
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60 #include "gimple-fold.h"
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61 #include "ubsan.h"
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62 #include "params.h"
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63 #include "builtins.h"
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64 #include "fnmatch.h"
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65 #include "tree-inline.h"
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66
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67 /* AddressSanitizer finds out-of-bounds and use-after-free bugs
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68 with <2x slowdown on average.
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69
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70 The tool consists of two parts:
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71 instrumentation module (this file) and a run-time library.
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72 The instrumentation module adds a run-time check before every memory insn.
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73 For a 8- or 16- byte load accessing address X:
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74 ShadowAddr = (X >> 3) + Offset
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75 ShadowValue = *(char*)ShadowAddr; // *(short*) for 16-byte access.
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76 if (ShadowValue)
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77 __asan_report_load8(X);
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78 For a load of N bytes (N=1, 2 or 4) from address X:
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79 ShadowAddr = (X >> 3) + Offset
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80 ShadowValue = *(char*)ShadowAddr;
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81 if (ShadowValue)
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82 if ((X & 7) + N - 1 > ShadowValue)
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83 __asan_report_loadN(X);
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84 Stores are instrumented similarly, but using __asan_report_storeN functions.
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85 A call too __asan_init_vN() is inserted to the list of module CTORs.
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86 N is the version number of the AddressSanitizer API. The changes between the
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87 API versions are listed in libsanitizer/asan/asan_interface_internal.h.
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88
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89 The run-time library redefines malloc (so that redzone are inserted around
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90 the allocated memory) and free (so that reuse of free-ed memory is delayed),
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91 provides __asan_report* and __asan_init_vN functions.
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92
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93 Read more:
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94 http://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm
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95
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96 The current implementation supports detection of out-of-bounds and
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97 use-after-free in the heap, on the stack and for global variables.
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98
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99 [Protection of stack variables]
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100
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101 To understand how detection of out-of-bounds and use-after-free works
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102 for stack variables, lets look at this example on x86_64 where the
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103 stack grows downward:
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104
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105 int
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106 foo ()
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107 {
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108 char a[23] = {0};
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109 int b[2] = {0};
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110
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111 a[5] = 1;
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112 b[1] = 2;
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113
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114 return a[5] + b[1];
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115 }
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116
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117 For this function, the stack protected by asan will be organized as
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118 follows, from the top of the stack to the bottom:
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119
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120 Slot 1/ [red zone of 32 bytes called 'RIGHT RedZone']
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121
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122 Slot 2/ [8 bytes of red zone, that adds up to the space of 'a' to make
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123 the next slot be 32 bytes aligned; this one is called Partial
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124 Redzone; this 32 bytes alignment is an asan constraint]
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125
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126 Slot 3/ [24 bytes for variable 'a']
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127
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128 Slot 4/ [red zone of 32 bytes called 'Middle RedZone']
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129
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130 Slot 5/ [24 bytes of Partial Red Zone (similar to slot 2]
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131
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132 Slot 6/ [8 bytes for variable 'b']
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133
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134 Slot 7/ [32 bytes of Red Zone at the bottom of the stack, called
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135 'LEFT RedZone']
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136
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137 The 32 bytes of LEFT red zone at the bottom of the stack can be
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138 decomposed as such:
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139
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140 1/ The first 8 bytes contain a magical asan number that is always
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141 0x41B58AB3.
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142
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143 2/ The following 8 bytes contains a pointer to a string (to be
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144 parsed at runtime by the runtime asan library), which format is
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145 the following:
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146
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147 "<function-name> <space> <num-of-variables-on-the-stack>
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148 (<32-bytes-aligned-offset-in-bytes-of-variable> <space>
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149 <length-of-var-in-bytes> ){n} "
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150
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151 where '(...){n}' means the content inside the parenthesis occurs 'n'
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152 times, with 'n' being the number of variables on the stack.
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153
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154 3/ The following 8 bytes contain the PC of the current function which
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155 will be used by the run-time library to print an error message.
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156
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157 4/ The following 8 bytes are reserved for internal use by the run-time.
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158
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159 The shadow memory for that stack layout is going to look like this:
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160
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161 - content of shadow memory 8 bytes for slot 7: 0xF1F1F1F1.
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162 The F1 byte pattern is a magic number called
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163 ASAN_STACK_MAGIC_LEFT and is a way for the runtime to know that
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164 the memory for that shadow byte is part of a the LEFT red zone
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165 intended to seat at the bottom of the variables on the stack.
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166
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167 - content of shadow memory 8 bytes for slots 6 and 5:
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168 0xF4F4F400. The F4 byte pattern is a magic number
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169 called ASAN_STACK_MAGIC_PARTIAL. It flags the fact that the
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170 memory region for this shadow byte is a PARTIAL red zone
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171 intended to pad a variable A, so that the slot following
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172 {A,padding} is 32 bytes aligned.
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173
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174 Note that the fact that the least significant byte of this
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175 shadow memory content is 00 means that 8 bytes of its
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176 corresponding memory (which corresponds to the memory of
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177 variable 'b') is addressable.
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178
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179 - content of shadow memory 8 bytes for slot 4: 0xF2F2F2F2.
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180 The F2 byte pattern is a magic number called
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181 ASAN_STACK_MAGIC_MIDDLE. It flags the fact that the memory
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182 region for this shadow byte is a MIDDLE red zone intended to
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183 seat between two 32 aligned slots of {variable,padding}.
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184
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185 - content of shadow memory 8 bytes for slot 3 and 2:
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186 0xF4000000. This represents is the concatenation of
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187 variable 'a' and the partial red zone following it, like what we
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188 had for variable 'b'. The least significant 3 bytes being 00
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189 means that the 3 bytes of variable 'a' are addressable.
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190
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191 - content of shadow memory 8 bytes for slot 1: 0xF3F3F3F3.
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192 The F3 byte pattern is a magic number called
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193 ASAN_STACK_MAGIC_RIGHT. It flags the fact that the memory
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194 region for this shadow byte is a RIGHT red zone intended to seat
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195 at the top of the variables of the stack.
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196
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197 Note that the real variable layout is done in expand_used_vars in
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198 cfgexpand.c. As far as Address Sanitizer is concerned, it lays out
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199 stack variables as well as the different red zones, emits some
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200 prologue code to populate the shadow memory as to poison (mark as
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201 non-accessible) the regions of the red zones and mark the regions of
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202 stack variables as accessible, and emit some epilogue code to
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203 un-poison (mark as accessible) the regions of red zones right before
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204 the function exits.
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205
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206 [Protection of global variables]
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207
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208 The basic idea is to insert a red zone between two global variables
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209 and install a constructor function that calls the asan runtime to do
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210 the populating of the relevant shadow memory regions at load time.
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211
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212 So the global variables are laid out as to insert a red zone between
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213 them. The size of the red zones is so that each variable starts on a
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214 32 bytes boundary.
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215
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216 Then a constructor function is installed so that, for each global
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217 variable, it calls the runtime asan library function
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218 __asan_register_globals_with an instance of this type:
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219
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220 struct __asan_global
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221 {
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222 // Address of the beginning of the global variable.
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223 const void *__beg;
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224
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225 // Initial size of the global variable.
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226 uptr __size;
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227
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228 // Size of the global variable + size of the red zone. This
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229 // size is 32 bytes aligned.
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230 uptr __size_with_redzone;
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231
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232 // Name of the global variable.
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233 const void *__name;
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234
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235 // Name of the module where the global variable is declared.
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236 const void *__module_name;
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237
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238 // 1 if it has dynamic initialization, 0 otherwise.
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239 uptr __has_dynamic_init;
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240
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241 // A pointer to struct that contains source location, could be NULL.
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242 __asan_global_source_location *__location;
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243 }
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244
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245 A destructor function that calls the runtime asan library function
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246 _asan_unregister_globals is also installed. */
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247
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248 static unsigned HOST_WIDE_INT asan_shadow_offset_value;
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249 static bool asan_shadow_offset_computed;
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250 static vec<char *> sanitized_sections;
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251 static tree last_alloca_addr;
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252
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253 /* Set of variable declarations that are going to be guarded by
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254 use-after-scope sanitizer. */
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255
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256 static hash_set<tree> *asan_handled_variables = NULL;
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257
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258 hash_set <tree> *asan_used_labels = NULL;
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259
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260 /* Sets shadow offset to value in string VAL. */
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261
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262 bool
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263 set_asan_shadow_offset (const char *val)
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264 {
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265 char *endp;
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266
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267 errno = 0;
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268 #ifdef HAVE_LONG_LONG
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269 asan_shadow_offset_value = strtoull (val, &endp, 0);
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270 #else
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271 asan_shadow_offset_value = strtoul (val, &endp, 0);
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272 #endif
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273 if (!(*val != '\0' && *endp == '\0' && errno == 0))
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274 return false;
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275
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276 asan_shadow_offset_computed = true;
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277
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278 return true;
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279 }
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280
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281 /* Set list of user-defined sections that need to be sanitized. */
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282
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283 void
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284 set_sanitized_sections (const char *sections)
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285 {
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286 char *pat;
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287 unsigned i;
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288 FOR_EACH_VEC_ELT (sanitized_sections, i, pat)
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289 free (pat);
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290 sanitized_sections.truncate (0);
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291
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292 for (const char *s = sections; *s; )
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293 {
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294 const char *end;
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295 for (end = s; *end && *end != ','; ++end);
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296 size_t len = end - s;
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297 sanitized_sections.safe_push (xstrndup (s, len));
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298 s = *end ? end + 1 : end;
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299 }
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300 }
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301
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302 bool
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303 asan_mark_p (gimple *stmt, enum asan_mark_flags flag)
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304 {
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305 return (gimple_call_internal_p (stmt, IFN_ASAN_MARK)
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306 && tree_to_uhwi (gimple_call_arg (stmt, 0)) == flag);
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307 }
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308
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309 bool
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310 asan_sanitize_stack_p (void)
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311 {
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312 return (sanitize_flags_p (SANITIZE_ADDRESS) && ASAN_STACK);
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313 }
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314
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315 bool
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316 asan_sanitize_allocas_p (void)
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317 {
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318 return (asan_sanitize_stack_p () && ASAN_PROTECT_ALLOCAS);
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319 }
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320
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321 /* Checks whether section SEC should be sanitized. */
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322
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323 static bool
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324 section_sanitized_p (const char *sec)
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325 {
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326 char *pat;
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327 unsigned i;
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328 FOR_EACH_VEC_ELT (sanitized_sections, i, pat)
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329 if (fnmatch (pat, sec, FNM_PERIOD) == 0)
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330 return true;
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331 return false;
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332 }
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333
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334 /* Returns Asan shadow offset. */
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335
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336 static unsigned HOST_WIDE_INT
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337 asan_shadow_offset ()
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338 {
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339 if (!asan_shadow_offset_computed)
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340 {
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341 asan_shadow_offset_computed = true;
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342 asan_shadow_offset_value = targetm.asan_shadow_offset ();
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343 }
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344 return asan_shadow_offset_value;
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345 }
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346
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347 alias_set_type asan_shadow_set = -1;
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348
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349 /* Pointer types to 1, 2 or 4 byte integers in shadow memory. A separate
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350 alias set is used for all shadow memory accesses. */
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351 static GTY(()) tree shadow_ptr_types[3];
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352
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353 /* Decl for __asan_option_detect_stack_use_after_return. */
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354 static GTY(()) tree asan_detect_stack_use_after_return;
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355
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356 /* Hashtable support for memory references used by gimple
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357 statements. */
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358
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359 /* This type represents a reference to a memory region. */
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360 struct asan_mem_ref
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361 {
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362 /* The expression of the beginning of the memory region. */
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363 tree start;
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364
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365 /* The size of the access. */
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366 HOST_WIDE_INT access_size;
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367 };
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368
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369 object_allocator <asan_mem_ref> asan_mem_ref_pool ("asan_mem_ref");
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370
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371 /* Initializes an instance of asan_mem_ref. */
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372
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373 static void
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374 asan_mem_ref_init (asan_mem_ref *ref, tree start, HOST_WIDE_INT access_size)
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375 {
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376 ref->start = start;
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377 ref->access_size = access_size;
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378 }
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379
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380 /* Allocates memory for an instance of asan_mem_ref into the memory
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381 pool returned by asan_mem_ref_get_alloc_pool and initialize it.
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382 START is the address of (or the expression pointing to) the
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383 beginning of memory reference. ACCESS_SIZE is the size of the
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384 access to the referenced memory. */
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385
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386 static asan_mem_ref*
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387 asan_mem_ref_new (tree start, HOST_WIDE_INT access_size)
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388 {
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389 asan_mem_ref *ref = asan_mem_ref_pool.allocate ();
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390
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391 asan_mem_ref_init (ref, start, access_size);
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392 return ref;
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393 }
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394
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395 /* This builds and returns a pointer to the end of the memory region
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396 that starts at START and of length LEN. */
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397
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398 tree
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399 asan_mem_ref_get_end (tree start, tree len)
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400 {
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401 if (len == NULL_TREE || integer_zerop (len))
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402 return start;
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403
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404 if (!ptrofftype_p (len))
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405 len = convert_to_ptrofftype (len);
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406
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407 return fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (start), start, len);
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408 }
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409
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410 /* Return a tree expression that represents the end of the referenced
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411 memory region. Beware that this function can actually build a new
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412 tree expression. */
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413
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414 tree
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415 asan_mem_ref_get_end (const asan_mem_ref *ref, tree len)
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416 {
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417 return asan_mem_ref_get_end (ref->start, len);
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418 }
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419
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420 struct asan_mem_ref_hasher : nofree_ptr_hash <asan_mem_ref>
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421 {
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422 static inline hashval_t hash (const asan_mem_ref *);
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423 static inline bool equal (const asan_mem_ref *, const asan_mem_ref *);
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424 };
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425
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426 /* Hash a memory reference. */
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427
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428 inline hashval_t
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429 asan_mem_ref_hasher::hash (const asan_mem_ref *mem_ref)
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430 {
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431 return iterative_hash_expr (mem_ref->start, 0);
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432 }
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433
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434 /* Compare two memory references. We accept the length of either
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435 memory references to be NULL_TREE. */
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436
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437 inline bool
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438 asan_mem_ref_hasher::equal (const asan_mem_ref *m1,
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439 const asan_mem_ref *m2)
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440 {
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441 return operand_equal_p (m1->start, m2->start, 0);
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442 }
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443
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444 static hash_table<asan_mem_ref_hasher> *asan_mem_ref_ht;
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445
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446 /* Returns a reference to the hash table containing memory references.
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447 This function ensures that the hash table is created. Note that
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448 this hash table is updated by the function
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449 update_mem_ref_hash_table. */
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450
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451 static hash_table<asan_mem_ref_hasher> *
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452 get_mem_ref_hash_table ()
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453 {
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454 if (!asan_mem_ref_ht)
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455 asan_mem_ref_ht = new hash_table<asan_mem_ref_hasher> (10);
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456
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457 return asan_mem_ref_ht;
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458 }
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459
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460 /* Clear all entries from the memory references hash table. */
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461
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462 static void
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463 empty_mem_ref_hash_table ()
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464 {
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465 if (asan_mem_ref_ht)
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466 asan_mem_ref_ht->empty ();
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467 }
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468
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469 /* Free the memory references hash table. */
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470
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471 static void
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472 free_mem_ref_resources ()
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473 {
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474 delete asan_mem_ref_ht;
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|
475 asan_mem_ref_ht = NULL;
|
|
476
|
|
477 asan_mem_ref_pool.release ();
|
|
478 }
|
|
479
|
|
480 /* Return true iff the memory reference REF has been instrumented. */
|
|
481
|
|
482 static bool
|
|
483 has_mem_ref_been_instrumented (tree ref, HOST_WIDE_INT access_size)
|
|
484 {
|
|
485 asan_mem_ref r;
|
|
486 asan_mem_ref_init (&r, ref, access_size);
|
|
487
|
|
488 asan_mem_ref *saved_ref = get_mem_ref_hash_table ()->find (&r);
|
|
489 return saved_ref && saved_ref->access_size >= access_size;
|
|
490 }
|
|
491
|
|
492 /* Return true iff the memory reference REF has been instrumented. */
|
|
493
|
|
494 static bool
|
|
495 has_mem_ref_been_instrumented (const asan_mem_ref *ref)
|
|
496 {
|
|
497 return has_mem_ref_been_instrumented (ref->start, ref->access_size);
|
|
498 }
|
|
499
|
|
500 /* Return true iff access to memory region starting at REF and of
|
|
501 length LEN has been instrumented. */
|
|
502
|
|
503 static bool
|
|
504 has_mem_ref_been_instrumented (const asan_mem_ref *ref, tree len)
|
|
505 {
|
|
506 HOST_WIDE_INT size_in_bytes
|
|
507 = tree_fits_shwi_p (len) ? tree_to_shwi (len) : -1;
|
|
508
|
|
509 return size_in_bytes != -1
|
|
510 && has_mem_ref_been_instrumented (ref->start, size_in_bytes);
|
|
511 }
|
|
512
|
|
513 /* Set REF to the memory reference present in a gimple assignment
|
|
514 ASSIGNMENT. Return true upon successful completion, false
|
|
515 otherwise. */
|
|
516
|
|
517 static bool
|
|
518 get_mem_ref_of_assignment (const gassign *assignment,
|
|
519 asan_mem_ref *ref,
|
|
520 bool *ref_is_store)
|
|
521 {
|
|
522 gcc_assert (gimple_assign_single_p (assignment));
|
|
523
|
|
524 if (gimple_store_p (assignment)
|
|
525 && !gimple_clobber_p (assignment))
|
|
526 {
|
|
527 ref->start = gimple_assign_lhs (assignment);
|
|
528 *ref_is_store = true;
|
|
529 }
|
|
530 else if (gimple_assign_load_p (assignment))
|
|
531 {
|
|
532 ref->start = gimple_assign_rhs1 (assignment);
|
|
533 *ref_is_store = false;
|
|
534 }
|
|
535 else
|
|
536 return false;
|
|
537
|
|
538 ref->access_size = int_size_in_bytes (TREE_TYPE (ref->start));
|
|
539 return true;
|
|
540 }
|
|
541
|
|
542 /* Return address of last allocated dynamic alloca. */
|
|
543
|
|
544 static tree
|
|
545 get_last_alloca_addr ()
|
|
546 {
|
|
547 if (last_alloca_addr)
|
|
548 return last_alloca_addr;
|
|
549
|
|
550 last_alloca_addr = create_tmp_reg (ptr_type_node, "last_alloca_addr");
|
|
551 gassign *g = gimple_build_assign (last_alloca_addr, null_pointer_node);
|
|
552 edge e = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
|
|
553 gsi_insert_on_edge_immediate (e, g);
|
|
554 return last_alloca_addr;
|
|
555 }
|
|
556
|
|
557 /* Insert __asan_allocas_unpoison (top, bottom) call after
|
|
558 __builtin_stack_restore (new_sp) call.
|
|
559 The pseudocode of this routine should look like this:
|
|
560 __builtin_stack_restore (new_sp);
|
|
561 top = last_alloca_addr;
|
|
562 bot = new_sp;
|
|
563 __asan_allocas_unpoison (top, bot);
|
|
564 last_alloca_addr = new_sp;
|
|
565 In general, we can't use new_sp as bot parameter because on some
|
|
566 architectures SP has non zero offset from dynamic stack area. Moreover, on
|
|
567 some architectures this offset (STACK_DYNAMIC_OFFSET) becomes known for each
|
|
568 particular function only after all callees were expanded to rtl.
|
|
569 The most noticeable example is PowerPC{,64}, see
|
|
570 http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html#DYNAM-STACK.
|
|
571 To overcome the issue we use following trick: pass new_sp as a second
|
|
572 parameter to __asan_allocas_unpoison and rewrite it during expansion with
|
|
573 virtual_dynamic_stack_rtx later in expand_asan_emit_allocas_unpoison
|
|
574 function.
|
|
575 */
|
|
576
|
|
577 static void
|
|
578 handle_builtin_stack_restore (gcall *call, gimple_stmt_iterator *iter)
|
|
579 {
|
|
580 if (!iter || !asan_sanitize_allocas_p ())
|
|
581 return;
|
|
582
|
|
583 tree last_alloca = get_last_alloca_addr ();
|
|
584 tree restored_stack = gimple_call_arg (call, 0);
|
|
585 tree fn = builtin_decl_implicit (BUILT_IN_ASAN_ALLOCAS_UNPOISON);
|
|
586 gimple *g = gimple_build_call (fn, 2, last_alloca, restored_stack);
|
|
587 gsi_insert_after (iter, g, GSI_NEW_STMT);
|
|
588 g = gimple_build_assign (last_alloca, restored_stack);
|
|
589 gsi_insert_after (iter, g, GSI_NEW_STMT);
|
|
590 }
|
|
591
|
|
592 /* Deploy and poison redzones around __builtin_alloca call. To do this, we
|
|
593 should replace this call with another one with changed parameters and
|
|
594 replace all its uses with new address, so
|
|
595 addr = __builtin_alloca (old_size, align);
|
|
596 is replaced by
|
|
597 left_redzone_size = max (align, ASAN_RED_ZONE_SIZE);
|
|
598 Following two statements are optimized out if we know that
|
|
599 old_size & (ASAN_RED_ZONE_SIZE - 1) == 0, i.e. alloca doesn't need partial
|
|
600 redzone.
|
|
601 misalign = old_size & (ASAN_RED_ZONE_SIZE - 1);
|
|
602 partial_redzone_size = ASAN_RED_ZONE_SIZE - misalign;
|
|
603 right_redzone_size = ASAN_RED_ZONE_SIZE;
|
|
604 additional_size = left_redzone_size + partial_redzone_size +
|
|
605 right_redzone_size;
|
|
606 new_size = old_size + additional_size;
|
|
607 new_alloca = __builtin_alloca (new_size, max (align, 32))
|
|
608 __asan_alloca_poison (new_alloca, old_size)
|
|
609 addr = new_alloca + max (align, ASAN_RED_ZONE_SIZE);
|
|
610 last_alloca_addr = new_alloca;
|
|
611 ADDITIONAL_SIZE is added to make new memory allocation contain not only
|
|
612 requested memory, but also left, partial and right redzones as well as some
|
|
613 additional space, required by alignment. */
|
|
614
|
|
615 static void
|
|
616 handle_builtin_alloca (gcall *call, gimple_stmt_iterator *iter)
|
|
617 {
|
|
618 if (!iter || !asan_sanitize_allocas_p ())
|
|
619 return;
|
|
620
|
|
621 gassign *g;
|
|
622 gcall *gg;
|
|
623 const HOST_WIDE_INT redzone_mask = ASAN_RED_ZONE_SIZE - 1;
|
|
624
|
|
625 tree last_alloca = get_last_alloca_addr ();
|
|
626 tree callee = gimple_call_fndecl (call);
|
|
627 tree old_size = gimple_call_arg (call, 0);
|
|
628 tree ptr_type = gimple_call_lhs (call) ? TREE_TYPE (gimple_call_lhs (call))
|
|
629 : ptr_type_node;
|
|
630 tree partial_size = NULL_TREE;
|
|
631 unsigned int align
|
|
632 = DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA
|
|
633 ? 0 : tree_to_uhwi (gimple_call_arg (call, 1));
|
|
634
|
|
635 /* If ALIGN > ASAN_RED_ZONE_SIZE, we embed left redzone into first ALIGN
|
|
636 bytes of allocated space. Otherwise, align alloca to ASAN_RED_ZONE_SIZE
|
|
637 manually. */
|
|
638 align = MAX (align, ASAN_RED_ZONE_SIZE * BITS_PER_UNIT);
|
|
639
|
|
640 tree alloca_rz_mask = build_int_cst (size_type_node, redzone_mask);
|
|
641 tree redzone_size = build_int_cst (size_type_node, ASAN_RED_ZONE_SIZE);
|
|
642
|
|
643 /* Extract lower bits from old_size. */
|
|
644 wide_int size_nonzero_bits = get_nonzero_bits (old_size);
|
|
645 wide_int rz_mask
|
|
646 = wi::uhwi (redzone_mask, wi::get_precision (size_nonzero_bits));
|
|
647 wide_int old_size_lower_bits = wi::bit_and (size_nonzero_bits, rz_mask);
|
|
648
|
|
649 /* If alloca size is aligned to ASAN_RED_ZONE_SIZE, we don't need partial
|
|
650 redzone. Otherwise, compute its size here. */
|
|
651 if (wi::ne_p (old_size_lower_bits, 0))
|
|
652 {
|
|
653 /* misalign = size & (ASAN_RED_ZONE_SIZE - 1)
|
|
654 partial_size = ASAN_RED_ZONE_SIZE - misalign. */
|
|
655 g = gimple_build_assign (make_ssa_name (size_type_node, NULL),
|
|
656 BIT_AND_EXPR, old_size, alloca_rz_mask);
|
|
657 gsi_insert_before (iter, g, GSI_SAME_STMT);
|
|
658 tree misalign = gimple_assign_lhs (g);
|
|
659 g = gimple_build_assign (make_ssa_name (size_type_node, NULL), MINUS_EXPR,
|
|
660 redzone_size, misalign);
|
|
661 gsi_insert_before (iter, g, GSI_SAME_STMT);
|
|
662 partial_size = gimple_assign_lhs (g);
|
|
663 }
|
|
664
|
|
665 /* additional_size = align + ASAN_RED_ZONE_SIZE. */
|
|
666 tree additional_size = build_int_cst (size_type_node, align / BITS_PER_UNIT
|
|
667 + ASAN_RED_ZONE_SIZE);
|
|
668 /* If alloca has partial redzone, include it to additional_size too. */
|
|
669 if (partial_size)
|
|
670 {
|
|
671 /* additional_size += partial_size. */
|
|
672 g = gimple_build_assign (make_ssa_name (size_type_node), PLUS_EXPR,
|
|
673 partial_size, additional_size);
|
|
674 gsi_insert_before (iter, g, GSI_SAME_STMT);
|
|
675 additional_size = gimple_assign_lhs (g);
|
|
676 }
|
|
677
|
|
678 /* new_size = old_size + additional_size. */
|
|
679 g = gimple_build_assign (make_ssa_name (size_type_node), PLUS_EXPR, old_size,
|
|
680 additional_size);
|
|
681 gsi_insert_before (iter, g, GSI_SAME_STMT);
|
|
682 tree new_size = gimple_assign_lhs (g);
|
|
683
|
|
684 /* Build new __builtin_alloca call:
|
|
685 new_alloca_with_rz = __builtin_alloca (new_size, align). */
|
|
686 tree fn = builtin_decl_implicit (BUILT_IN_ALLOCA_WITH_ALIGN);
|
|
687 gg = gimple_build_call (fn, 2, new_size,
|
|
688 build_int_cst (size_type_node, align));
|
|
689 tree new_alloca_with_rz = make_ssa_name (ptr_type, gg);
|
|
690 gimple_call_set_lhs (gg, new_alloca_with_rz);
|
|
691 gsi_insert_before (iter, gg, GSI_SAME_STMT);
|
|
692
|
|
693 /* new_alloca = new_alloca_with_rz + align. */
|
|
694 g = gimple_build_assign (make_ssa_name (ptr_type), POINTER_PLUS_EXPR,
|
|
695 new_alloca_with_rz,
|
|
696 build_int_cst (size_type_node,
|
|
697 align / BITS_PER_UNIT));
|
|
698 gsi_insert_before (iter, g, GSI_SAME_STMT);
|
|
699 tree new_alloca = gimple_assign_lhs (g);
|
|
700
|
|
701 /* Poison newly created alloca redzones:
|
|
702 __asan_alloca_poison (new_alloca, old_size). */
|
|
703 fn = builtin_decl_implicit (BUILT_IN_ASAN_ALLOCA_POISON);
|
|
704 gg = gimple_build_call (fn, 2, new_alloca, old_size);
|
|
705 gsi_insert_before (iter, gg, GSI_SAME_STMT);
|
|
706
|
|
707 /* Save new_alloca_with_rz value into last_alloca to use it during
|
|
708 allocas unpoisoning. */
|
|
709 g = gimple_build_assign (last_alloca, new_alloca_with_rz);
|
|
710 gsi_insert_before (iter, g, GSI_SAME_STMT);
|
|
711
|
|
712 /* Finally, replace old alloca ptr with NEW_ALLOCA. */
|
|
713 replace_call_with_value (iter, new_alloca);
|
|
714 }
|
|
715
|
|
716 /* Return the memory references contained in a gimple statement
|
|
717 representing a builtin call that has to do with memory access. */
|
|
718
|
|
719 static bool
|
|
720 get_mem_refs_of_builtin_call (gcall *call,
|
|
721 asan_mem_ref *src0,
|
|
722 tree *src0_len,
|
|
723 bool *src0_is_store,
|
|
724 asan_mem_ref *src1,
|
|
725 tree *src1_len,
|
|
726 bool *src1_is_store,
|
|
727 asan_mem_ref *dst,
|
|
728 tree *dst_len,
|
|
729 bool *dst_is_store,
|
|
730 bool *dest_is_deref,
|
|
731 bool *intercepted_p,
|
|
732 gimple_stmt_iterator *iter = NULL)
|
|
733 {
|
|
734 gcc_checking_assert (gimple_call_builtin_p (call, BUILT_IN_NORMAL));
|
|
735
|
|
736 tree callee = gimple_call_fndecl (call);
|
|
737 tree source0 = NULL_TREE, source1 = NULL_TREE,
|
|
738 dest = NULL_TREE, len = NULL_TREE;
|
|
739 bool is_store = true, got_reference_p = false;
|
|
740 HOST_WIDE_INT access_size = 1;
|
|
741
|
|
742 *intercepted_p = asan_intercepted_p ((DECL_FUNCTION_CODE (callee)));
|
|
743
|
|
744 switch (DECL_FUNCTION_CODE (callee))
|
|
745 {
|
|
746 /* (s, s, n) style memops. */
|
|
747 case BUILT_IN_BCMP:
|
|
748 case BUILT_IN_MEMCMP:
|
|
749 source0 = gimple_call_arg (call, 0);
|
|
750 source1 = gimple_call_arg (call, 1);
|
|
751 len = gimple_call_arg (call, 2);
|
|
752 break;
|
|
753
|
|
754 /* (src, dest, n) style memops. */
|
|
755 case BUILT_IN_BCOPY:
|
|
756 source0 = gimple_call_arg (call, 0);
|
|
757 dest = gimple_call_arg (call, 1);
|
|
758 len = gimple_call_arg (call, 2);
|
|
759 break;
|
|
760
|
|
761 /* (dest, src, n) style memops. */
|
|
762 case BUILT_IN_MEMCPY:
|
|
763 case BUILT_IN_MEMCPY_CHK:
|
|
764 case BUILT_IN_MEMMOVE:
|
|
765 case BUILT_IN_MEMMOVE_CHK:
|
|
766 case BUILT_IN_MEMPCPY:
|
|
767 case BUILT_IN_MEMPCPY_CHK:
|
|
768 dest = gimple_call_arg (call, 0);
|
|
769 source0 = gimple_call_arg (call, 1);
|
|
770 len = gimple_call_arg (call, 2);
|
|
771 break;
|
|
772
|
|
773 /* (dest, n) style memops. */
|
|
774 case BUILT_IN_BZERO:
|
|
775 dest = gimple_call_arg (call, 0);
|
|
776 len = gimple_call_arg (call, 1);
|
|
777 break;
|
|
778
|
|
779 /* (dest, x, n) style memops*/
|
|
780 case BUILT_IN_MEMSET:
|
|
781 case BUILT_IN_MEMSET_CHK:
|
|
782 dest = gimple_call_arg (call, 0);
|
|
783 len = gimple_call_arg (call, 2);
|
|
784 break;
|
|
785
|
|
786 case BUILT_IN_STRLEN:
|
|
787 source0 = gimple_call_arg (call, 0);
|
|
788 len = gimple_call_lhs (call);
|
|
789 break;
|
|
790
|
|
791 case BUILT_IN_STACK_RESTORE:
|
|
792 handle_builtin_stack_restore (call, iter);
|
|
793 break;
|
|
794
|
|
795 CASE_BUILT_IN_ALLOCA:
|
|
796 handle_builtin_alloca (call, iter);
|
|
797 break;
|
|
798 /* And now the __atomic* and __sync builtins.
|
|
799 These are handled differently from the classical memory memory
|
|
800 access builtins above. */
|
|
801
|
|
802 case BUILT_IN_ATOMIC_LOAD_1:
|
|
803 is_store = false;
|
|
804 /* FALLTHRU */
|
|
805 case BUILT_IN_SYNC_FETCH_AND_ADD_1:
|
|
806 case BUILT_IN_SYNC_FETCH_AND_SUB_1:
|
|
807 case BUILT_IN_SYNC_FETCH_AND_OR_1:
|
|
808 case BUILT_IN_SYNC_FETCH_AND_AND_1:
|
|
809 case BUILT_IN_SYNC_FETCH_AND_XOR_1:
|
|
810 case BUILT_IN_SYNC_FETCH_AND_NAND_1:
|
|
811 case BUILT_IN_SYNC_ADD_AND_FETCH_1:
|
|
812 case BUILT_IN_SYNC_SUB_AND_FETCH_1:
|
|
813 case BUILT_IN_SYNC_OR_AND_FETCH_1:
|
|
814 case BUILT_IN_SYNC_AND_AND_FETCH_1:
|
|
815 case BUILT_IN_SYNC_XOR_AND_FETCH_1:
|
|
816 case BUILT_IN_SYNC_NAND_AND_FETCH_1:
|
|
817 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_1:
|
|
818 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_1:
|
|
819 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_1:
|
|
820 case BUILT_IN_SYNC_LOCK_RELEASE_1:
|
|
821 case BUILT_IN_ATOMIC_EXCHANGE_1:
|
|
822 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_1:
|
|
823 case BUILT_IN_ATOMIC_STORE_1:
|
|
824 case BUILT_IN_ATOMIC_ADD_FETCH_1:
|
|
825 case BUILT_IN_ATOMIC_SUB_FETCH_1:
|
|
826 case BUILT_IN_ATOMIC_AND_FETCH_1:
|
|
827 case BUILT_IN_ATOMIC_NAND_FETCH_1:
|
|
828 case BUILT_IN_ATOMIC_XOR_FETCH_1:
|
|
829 case BUILT_IN_ATOMIC_OR_FETCH_1:
|
|
830 case BUILT_IN_ATOMIC_FETCH_ADD_1:
|
|
831 case BUILT_IN_ATOMIC_FETCH_SUB_1:
|
|
832 case BUILT_IN_ATOMIC_FETCH_AND_1:
|
|
833 case BUILT_IN_ATOMIC_FETCH_NAND_1:
|
|
834 case BUILT_IN_ATOMIC_FETCH_XOR_1:
|
|
835 case BUILT_IN_ATOMIC_FETCH_OR_1:
|
|
836 access_size = 1;
|
|
837 goto do_atomic;
|
|
838
|
|
839 case BUILT_IN_ATOMIC_LOAD_2:
|
|
840 is_store = false;
|
|
841 /* FALLTHRU */
|
|
842 case BUILT_IN_SYNC_FETCH_AND_ADD_2:
|
|
843 case BUILT_IN_SYNC_FETCH_AND_SUB_2:
|
|
844 case BUILT_IN_SYNC_FETCH_AND_OR_2:
|
|
845 case BUILT_IN_SYNC_FETCH_AND_AND_2:
|
|
846 case BUILT_IN_SYNC_FETCH_AND_XOR_2:
|
|
847 case BUILT_IN_SYNC_FETCH_AND_NAND_2:
|
|
848 case BUILT_IN_SYNC_ADD_AND_FETCH_2:
|
|
849 case BUILT_IN_SYNC_SUB_AND_FETCH_2:
|
|
850 case BUILT_IN_SYNC_OR_AND_FETCH_2:
|
|
851 case BUILT_IN_SYNC_AND_AND_FETCH_2:
|
|
852 case BUILT_IN_SYNC_XOR_AND_FETCH_2:
|
|
853 case BUILT_IN_SYNC_NAND_AND_FETCH_2:
|
|
854 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_2:
|
|
855 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_2:
|
|
856 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_2:
|
|
857 case BUILT_IN_SYNC_LOCK_RELEASE_2:
|
|
858 case BUILT_IN_ATOMIC_EXCHANGE_2:
|
|
859 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_2:
|
|
860 case BUILT_IN_ATOMIC_STORE_2:
|
|
861 case BUILT_IN_ATOMIC_ADD_FETCH_2:
|
|
862 case BUILT_IN_ATOMIC_SUB_FETCH_2:
|
|
863 case BUILT_IN_ATOMIC_AND_FETCH_2:
|
|
864 case BUILT_IN_ATOMIC_NAND_FETCH_2:
|
|
865 case BUILT_IN_ATOMIC_XOR_FETCH_2:
|
|
866 case BUILT_IN_ATOMIC_OR_FETCH_2:
|
|
867 case BUILT_IN_ATOMIC_FETCH_ADD_2:
|
|
868 case BUILT_IN_ATOMIC_FETCH_SUB_2:
|
|
869 case BUILT_IN_ATOMIC_FETCH_AND_2:
|
|
870 case BUILT_IN_ATOMIC_FETCH_NAND_2:
|
|
871 case BUILT_IN_ATOMIC_FETCH_XOR_2:
|
|
872 case BUILT_IN_ATOMIC_FETCH_OR_2:
|
|
873 access_size = 2;
|
|
874 goto do_atomic;
|
|
875
|
|
876 case BUILT_IN_ATOMIC_LOAD_4:
|
|
877 is_store = false;
|
|
878 /* FALLTHRU */
|
|
879 case BUILT_IN_SYNC_FETCH_AND_ADD_4:
|
|
880 case BUILT_IN_SYNC_FETCH_AND_SUB_4:
|
|
881 case BUILT_IN_SYNC_FETCH_AND_OR_4:
|
|
882 case BUILT_IN_SYNC_FETCH_AND_AND_4:
|
|
883 case BUILT_IN_SYNC_FETCH_AND_XOR_4:
|
|
884 case BUILT_IN_SYNC_FETCH_AND_NAND_4:
|
|
885 case BUILT_IN_SYNC_ADD_AND_FETCH_4:
|
|
886 case BUILT_IN_SYNC_SUB_AND_FETCH_4:
|
|
887 case BUILT_IN_SYNC_OR_AND_FETCH_4:
|
|
888 case BUILT_IN_SYNC_AND_AND_FETCH_4:
|
|
889 case BUILT_IN_SYNC_XOR_AND_FETCH_4:
|
|
890 case BUILT_IN_SYNC_NAND_AND_FETCH_4:
|
|
891 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_4:
|
|
892 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_4:
|
|
893 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_4:
|
|
894 case BUILT_IN_SYNC_LOCK_RELEASE_4:
|
|
895 case BUILT_IN_ATOMIC_EXCHANGE_4:
|
|
896 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_4:
|
|
897 case BUILT_IN_ATOMIC_STORE_4:
|
|
898 case BUILT_IN_ATOMIC_ADD_FETCH_4:
|
|
899 case BUILT_IN_ATOMIC_SUB_FETCH_4:
|
|
900 case BUILT_IN_ATOMIC_AND_FETCH_4:
|
|
901 case BUILT_IN_ATOMIC_NAND_FETCH_4:
|
|
902 case BUILT_IN_ATOMIC_XOR_FETCH_4:
|
|
903 case BUILT_IN_ATOMIC_OR_FETCH_4:
|
|
904 case BUILT_IN_ATOMIC_FETCH_ADD_4:
|
|
905 case BUILT_IN_ATOMIC_FETCH_SUB_4:
|
|
906 case BUILT_IN_ATOMIC_FETCH_AND_4:
|
|
907 case BUILT_IN_ATOMIC_FETCH_NAND_4:
|
|
908 case BUILT_IN_ATOMIC_FETCH_XOR_4:
|
|
909 case BUILT_IN_ATOMIC_FETCH_OR_4:
|
|
910 access_size = 4;
|
|
911 goto do_atomic;
|
|
912
|
|
913 case BUILT_IN_ATOMIC_LOAD_8:
|
|
914 is_store = false;
|
|
915 /* FALLTHRU */
|
|
916 case BUILT_IN_SYNC_FETCH_AND_ADD_8:
|
|
917 case BUILT_IN_SYNC_FETCH_AND_SUB_8:
|
|
918 case BUILT_IN_SYNC_FETCH_AND_OR_8:
|
|
919 case BUILT_IN_SYNC_FETCH_AND_AND_8:
|
|
920 case BUILT_IN_SYNC_FETCH_AND_XOR_8:
|
|
921 case BUILT_IN_SYNC_FETCH_AND_NAND_8:
|
|
922 case BUILT_IN_SYNC_ADD_AND_FETCH_8:
|
|
923 case BUILT_IN_SYNC_SUB_AND_FETCH_8:
|
|
924 case BUILT_IN_SYNC_OR_AND_FETCH_8:
|
|
925 case BUILT_IN_SYNC_AND_AND_FETCH_8:
|
|
926 case BUILT_IN_SYNC_XOR_AND_FETCH_8:
|
|
927 case BUILT_IN_SYNC_NAND_AND_FETCH_8:
|
|
928 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_8:
|
|
929 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_8:
|
|
930 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_8:
|
|
931 case BUILT_IN_SYNC_LOCK_RELEASE_8:
|
|
932 case BUILT_IN_ATOMIC_EXCHANGE_8:
|
|
933 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_8:
|
|
934 case BUILT_IN_ATOMIC_STORE_8:
|
|
935 case BUILT_IN_ATOMIC_ADD_FETCH_8:
|
|
936 case BUILT_IN_ATOMIC_SUB_FETCH_8:
|
|
937 case BUILT_IN_ATOMIC_AND_FETCH_8:
|
|
938 case BUILT_IN_ATOMIC_NAND_FETCH_8:
|
|
939 case BUILT_IN_ATOMIC_XOR_FETCH_8:
|
|
940 case BUILT_IN_ATOMIC_OR_FETCH_8:
|
|
941 case BUILT_IN_ATOMIC_FETCH_ADD_8:
|
|
942 case BUILT_IN_ATOMIC_FETCH_SUB_8:
|
|
943 case BUILT_IN_ATOMIC_FETCH_AND_8:
|
|
944 case BUILT_IN_ATOMIC_FETCH_NAND_8:
|
|
945 case BUILT_IN_ATOMIC_FETCH_XOR_8:
|
|
946 case BUILT_IN_ATOMIC_FETCH_OR_8:
|
|
947 access_size = 8;
|
|
948 goto do_atomic;
|
|
949
|
|
950 case BUILT_IN_ATOMIC_LOAD_16:
|
|
951 is_store = false;
|
|
952 /* FALLTHRU */
|
|
953 case BUILT_IN_SYNC_FETCH_AND_ADD_16:
|
|
954 case BUILT_IN_SYNC_FETCH_AND_SUB_16:
|
|
955 case BUILT_IN_SYNC_FETCH_AND_OR_16:
|
|
956 case BUILT_IN_SYNC_FETCH_AND_AND_16:
|
|
957 case BUILT_IN_SYNC_FETCH_AND_XOR_16:
|
|
958 case BUILT_IN_SYNC_FETCH_AND_NAND_16:
|
|
959 case BUILT_IN_SYNC_ADD_AND_FETCH_16:
|
|
960 case BUILT_IN_SYNC_SUB_AND_FETCH_16:
|
|
961 case BUILT_IN_SYNC_OR_AND_FETCH_16:
|
|
962 case BUILT_IN_SYNC_AND_AND_FETCH_16:
|
|
963 case BUILT_IN_SYNC_XOR_AND_FETCH_16:
|
|
964 case BUILT_IN_SYNC_NAND_AND_FETCH_16:
|
|
965 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_16:
|
|
966 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_16:
|
|
967 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_16:
|
|
968 case BUILT_IN_SYNC_LOCK_RELEASE_16:
|
|
969 case BUILT_IN_ATOMIC_EXCHANGE_16:
|
|
970 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_16:
|
|
971 case BUILT_IN_ATOMIC_STORE_16:
|
|
972 case BUILT_IN_ATOMIC_ADD_FETCH_16:
|
|
973 case BUILT_IN_ATOMIC_SUB_FETCH_16:
|
|
974 case BUILT_IN_ATOMIC_AND_FETCH_16:
|
|
975 case BUILT_IN_ATOMIC_NAND_FETCH_16:
|
|
976 case BUILT_IN_ATOMIC_XOR_FETCH_16:
|
|
977 case BUILT_IN_ATOMIC_OR_FETCH_16:
|
|
978 case BUILT_IN_ATOMIC_FETCH_ADD_16:
|
|
979 case BUILT_IN_ATOMIC_FETCH_SUB_16:
|
|
980 case BUILT_IN_ATOMIC_FETCH_AND_16:
|
|
981 case BUILT_IN_ATOMIC_FETCH_NAND_16:
|
|
982 case BUILT_IN_ATOMIC_FETCH_XOR_16:
|
|
983 case BUILT_IN_ATOMIC_FETCH_OR_16:
|
|
984 access_size = 16;
|
|
985 /* FALLTHRU */
|
|
986 do_atomic:
|
|
987 {
|
|
988 dest = gimple_call_arg (call, 0);
|
|
989 /* DEST represents the address of a memory location.
|
|
990 instrument_derefs wants the memory location, so lets
|
|
991 dereference the address DEST before handing it to
|
|
992 instrument_derefs. */
|
|
993 tree type = build_nonstandard_integer_type (access_size
|
|
994 * BITS_PER_UNIT, 1);
|
|
995 dest = build2 (MEM_REF, type, dest,
|
|
996 build_int_cst (build_pointer_type (char_type_node), 0));
|
|
997 break;
|
|
998 }
|
|
999
|
|
1000 default:
|
|
1001 /* The other builtins memory access are not instrumented in this
|
|
1002 function because they either don't have any length parameter,
|
|
1003 or their length parameter is just a limit. */
|
|
1004 break;
|
|
1005 }
|
|
1006
|
|
1007 if (len != NULL_TREE)
|
|
1008 {
|
|
1009 if (source0 != NULL_TREE)
|
|
1010 {
|
|
1011 src0->start = source0;
|
|
1012 src0->access_size = access_size;
|
|
1013 *src0_len = len;
|
|
1014 *src0_is_store = false;
|
|
1015 }
|
|
1016
|
|
1017 if (source1 != NULL_TREE)
|
|
1018 {
|
|
1019 src1->start = source1;
|
|
1020 src1->access_size = access_size;
|
|
1021 *src1_len = len;
|
|
1022 *src1_is_store = false;
|
|
1023 }
|
|
1024
|
|
1025 if (dest != NULL_TREE)
|
|
1026 {
|
|
1027 dst->start = dest;
|
|
1028 dst->access_size = access_size;
|
|
1029 *dst_len = len;
|
|
1030 *dst_is_store = true;
|
|
1031 }
|
|
1032
|
|
1033 got_reference_p = true;
|
|
1034 }
|
|
1035 else if (dest)
|
|
1036 {
|
|
1037 dst->start = dest;
|
|
1038 dst->access_size = access_size;
|
|
1039 *dst_len = NULL_TREE;
|
|
1040 *dst_is_store = is_store;
|
|
1041 *dest_is_deref = true;
|
|
1042 got_reference_p = true;
|
|
1043 }
|
|
1044
|
|
1045 return got_reference_p;
|
|
1046 }
|
|
1047
|
|
1048 /* Return true iff a given gimple statement has been instrumented.
|
|
1049 Note that the statement is "defined" by the memory references it
|
|
1050 contains. */
|
|
1051
|
|
1052 static bool
|
|
1053 has_stmt_been_instrumented_p (gimple *stmt)
|
|
1054 {
|
|
1055 if (gimple_assign_single_p (stmt))
|
|
1056 {
|
|
1057 bool r_is_store;
|
|
1058 asan_mem_ref r;
|
|
1059 asan_mem_ref_init (&r, NULL, 1);
|
|
1060
|
|
1061 if (get_mem_ref_of_assignment (as_a <gassign *> (stmt), &r,
|
|
1062 &r_is_store))
|
|
1063 return has_mem_ref_been_instrumented (&r);
|
|
1064 }
|
|
1065 else if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
|
|
1066 {
|
|
1067 asan_mem_ref src0, src1, dest;
|
|
1068 asan_mem_ref_init (&src0, NULL, 1);
|
|
1069 asan_mem_ref_init (&src1, NULL, 1);
|
|
1070 asan_mem_ref_init (&dest, NULL, 1);
|
|
1071
|
|
1072 tree src0_len = NULL_TREE, src1_len = NULL_TREE, dest_len = NULL_TREE;
|
|
1073 bool src0_is_store = false, src1_is_store = false,
|
|
1074 dest_is_store = false, dest_is_deref = false, intercepted_p = true;
|
|
1075 if (get_mem_refs_of_builtin_call (as_a <gcall *> (stmt),
|
|
1076 &src0, &src0_len, &src0_is_store,
|
|
1077 &src1, &src1_len, &src1_is_store,
|
|
1078 &dest, &dest_len, &dest_is_store,
|
|
1079 &dest_is_deref, &intercepted_p))
|
|
1080 {
|
|
1081 if (src0.start != NULL_TREE
|
|
1082 && !has_mem_ref_been_instrumented (&src0, src0_len))
|
|
1083 return false;
|
|
1084
|
|
1085 if (src1.start != NULL_TREE
|
|
1086 && !has_mem_ref_been_instrumented (&src1, src1_len))
|
|
1087 return false;
|
|
1088
|
|
1089 if (dest.start != NULL_TREE
|
|
1090 && !has_mem_ref_been_instrumented (&dest, dest_len))
|
|
1091 return false;
|
|
1092
|
|
1093 return true;
|
|
1094 }
|
|
1095 }
|
|
1096 else if (is_gimple_call (stmt) && gimple_store_p (stmt))
|
|
1097 {
|
|
1098 asan_mem_ref r;
|
|
1099 asan_mem_ref_init (&r, NULL, 1);
|
|
1100
|
|
1101 r.start = gimple_call_lhs (stmt);
|
|
1102 r.access_size = int_size_in_bytes (TREE_TYPE (r.start));
|
|
1103 return has_mem_ref_been_instrumented (&r);
|
|
1104 }
|
|
1105
|
|
1106 return false;
|
|
1107 }
|
|
1108
|
|
1109 /* Insert a memory reference into the hash table. */
|
|
1110
|
|
1111 static void
|
|
1112 update_mem_ref_hash_table (tree ref, HOST_WIDE_INT access_size)
|
|
1113 {
|
|
1114 hash_table<asan_mem_ref_hasher> *ht = get_mem_ref_hash_table ();
|
|
1115
|
|
1116 asan_mem_ref r;
|
|
1117 asan_mem_ref_init (&r, ref, access_size);
|
|
1118
|
|
1119 asan_mem_ref **slot = ht->find_slot (&r, INSERT);
|
|
1120 if (*slot == NULL || (*slot)->access_size < access_size)
|
|
1121 *slot = asan_mem_ref_new (ref, access_size);
|
|
1122 }
|
|
1123
|
|
1124 /* Initialize shadow_ptr_types array. */
|
|
1125
|
|
1126 static void
|
|
1127 asan_init_shadow_ptr_types (void)
|
|
1128 {
|
|
1129 asan_shadow_set = new_alias_set ();
|
|
1130 tree types[3] = { signed_char_type_node, short_integer_type_node,
|
|
1131 integer_type_node };
|
|
1132
|
|
1133 for (unsigned i = 0; i < 3; i++)
|
|
1134 {
|
|
1135 shadow_ptr_types[i] = build_distinct_type_copy (types[i]);
|
|
1136 TYPE_ALIAS_SET (shadow_ptr_types[i]) = asan_shadow_set;
|
|
1137 shadow_ptr_types[i] = build_pointer_type (shadow_ptr_types[i]);
|
|
1138 }
|
|
1139
|
|
1140 initialize_sanitizer_builtins ();
|
|
1141 }
|
|
1142
|
|
1143 /* Create ADDR_EXPR of STRING_CST with the PP pretty printer text. */
|
|
1144
|
|
1145 static tree
|
|
1146 asan_pp_string (pretty_printer *pp)
|
|
1147 {
|
|
1148 const char *buf = pp_formatted_text (pp);
|
|
1149 size_t len = strlen (buf);
|
|
1150 tree ret = build_string (len + 1, buf);
|
|
1151 TREE_TYPE (ret)
|
|
1152 = build_array_type (TREE_TYPE (shadow_ptr_types[0]),
|
|
1153 build_index_type (size_int (len)));
|
|
1154 TREE_READONLY (ret) = 1;
|
|
1155 TREE_STATIC (ret) = 1;
|
|
1156 return build1 (ADDR_EXPR, shadow_ptr_types[0], ret);
|
|
1157 }
|
|
1158
|
|
1159 /* Return a CONST_INT representing 4 subsequent shadow memory bytes. */
|
|
1160
|
|
1161 static rtx
|
|
1162 asan_shadow_cst (unsigned char shadow_bytes[4])
|
|
1163 {
|
|
1164 int i;
|
|
1165 unsigned HOST_WIDE_INT val = 0;
|
|
1166 gcc_assert (WORDS_BIG_ENDIAN == BYTES_BIG_ENDIAN);
|
|
1167 for (i = 0; i < 4; i++)
|
|
1168 val |= (unsigned HOST_WIDE_INT) shadow_bytes[BYTES_BIG_ENDIAN ? 3 - i : i]
|
|
1169 << (BITS_PER_UNIT * i);
|
|
1170 return gen_int_mode (val, SImode);
|
|
1171 }
|
|
1172
|
|
1173 /* Clear shadow memory at SHADOW_MEM, LEN bytes. Can't call a library call here
|
|
1174 though. */
|
|
1175
|
|
1176 static void
|
|
1177 asan_clear_shadow (rtx shadow_mem, HOST_WIDE_INT len)
|
|
1178 {
|
|
1179 rtx_insn *insn, *insns, *jump;
|
|
1180 rtx_code_label *top_label;
|
|
1181 rtx end, addr, tmp;
|
|
1182
|
|
1183 start_sequence ();
|
|
1184 clear_storage (shadow_mem, GEN_INT (len), BLOCK_OP_NORMAL);
|
|
1185 insns = get_insns ();
|
|
1186 end_sequence ();
|
|
1187 for (insn = insns; insn; insn = NEXT_INSN (insn))
|
|
1188 if (CALL_P (insn))
|
|
1189 break;
|
|
1190 if (insn == NULL_RTX)
|
|
1191 {
|
|
1192 emit_insn (insns);
|
|
1193 return;
|
|
1194 }
|
|
1195
|
|
1196 gcc_assert ((len & 3) == 0);
|
|
1197 top_label = gen_label_rtx ();
|
|
1198 addr = copy_to_mode_reg (Pmode, XEXP (shadow_mem, 0));
|
|
1199 shadow_mem = adjust_automodify_address (shadow_mem, SImode, addr, 0);
|
|
1200 end = force_reg (Pmode, plus_constant (Pmode, addr, len));
|
|
1201 emit_label (top_label);
|
|
1202
|
|
1203 emit_move_insn (shadow_mem, const0_rtx);
|
|
1204 tmp = expand_simple_binop (Pmode, PLUS, addr, gen_int_mode (4, Pmode), addr,
|
|
1205 true, OPTAB_LIB_WIDEN);
|
|
1206 if (tmp != addr)
|
|
1207 emit_move_insn (addr, tmp);
|
|
1208 emit_cmp_and_jump_insns (addr, end, LT, NULL_RTX, Pmode, true, top_label);
|
|
1209 jump = get_last_insn ();
|
|
1210 gcc_assert (JUMP_P (jump));
|
|
1211 add_reg_br_prob_note (jump,
|
|
1212 profile_probability::guessed_always ()
|
|
1213 .apply_scale (80, 100));
|
|
1214 }
|
|
1215
|
|
1216 void
|
|
1217 asan_function_start (void)
|
|
1218 {
|
|
1219 section *fnsec = function_section (current_function_decl);
|
|
1220 switch_to_section (fnsec);
|
|
1221 ASM_OUTPUT_DEBUG_LABEL (asm_out_file, "LASANPC",
|
|
1222 current_function_funcdef_no);
|
|
1223 }
|
|
1224
|
|
1225 /* Return number of shadow bytes that are occupied by a local variable
|
|
1226 of SIZE bytes. */
|
|
1227
|
|
1228 static unsigned HOST_WIDE_INT
|
|
1229 shadow_mem_size (unsigned HOST_WIDE_INT size)
|
|
1230 {
|
|
1231 return ROUND_UP (size, ASAN_SHADOW_GRANULARITY) / ASAN_SHADOW_GRANULARITY;
|
|
1232 }
|
|
1233
|
|
1234 /* Insert code to protect stack vars. The prologue sequence should be emitted
|
|
1235 directly, epilogue sequence returned. BASE is the register holding the
|
|
1236 stack base, against which OFFSETS array offsets are relative to, OFFSETS
|
|
1237 array contains pairs of offsets in reverse order, always the end offset
|
|
1238 of some gap that needs protection followed by starting offset,
|
|
1239 and DECLS is an array of representative decls for each var partition.
|
|
1240 LENGTH is the length of the OFFSETS array, DECLS array is LENGTH / 2 - 1
|
|
1241 elements long (OFFSETS include gap before the first variable as well
|
|
1242 as gaps after each stack variable). PBASE is, if non-NULL, some pseudo
|
|
1243 register which stack vars DECL_RTLs are based on. Either BASE should be
|
|
1244 assigned to PBASE, when not doing use after return protection, or
|
|
1245 corresponding address based on __asan_stack_malloc* return value. */
|
|
1246
|
|
1247 rtx_insn *
|
|
1248 asan_emit_stack_protection (rtx base, rtx pbase, unsigned int alignb,
|
|
1249 HOST_WIDE_INT *offsets, tree *decls, int length)
|
|
1250 {
|
|
1251 rtx shadow_base, shadow_mem, ret, mem, orig_base;
|
|
1252 rtx_code_label *lab;
|
|
1253 rtx_insn *insns;
|
|
1254 char buf[32];
|
|
1255 unsigned char shadow_bytes[4];
|
|
1256 HOST_WIDE_INT base_offset = offsets[length - 1];
|
|
1257 HOST_WIDE_INT base_align_bias = 0, offset, prev_offset;
|
|
1258 HOST_WIDE_INT asan_frame_size = offsets[0] - base_offset;
|
|
1259 HOST_WIDE_INT last_offset, last_size;
|
|
1260 int l;
|
|
1261 unsigned char cur_shadow_byte = ASAN_STACK_MAGIC_LEFT;
|
|
1262 tree str_cst, decl, id;
|
|
1263 int use_after_return_class = -1;
|
|
1264
|
|
1265 if (shadow_ptr_types[0] == NULL_TREE)
|
|
1266 asan_init_shadow_ptr_types ();
|
|
1267
|
|
1268 /* First of all, prepare the description string. */
|
|
1269 pretty_printer asan_pp;
|
|
1270
|
|
1271 pp_decimal_int (&asan_pp, length / 2 - 1);
|
|
1272 pp_space (&asan_pp);
|
|
1273 for (l = length - 2; l; l -= 2)
|
|
1274 {
|
|
1275 tree decl = decls[l / 2 - 1];
|
|
1276 pp_wide_integer (&asan_pp, offsets[l] - base_offset);
|
|
1277 pp_space (&asan_pp);
|
|
1278 pp_wide_integer (&asan_pp, offsets[l - 1] - offsets[l]);
|
|
1279 pp_space (&asan_pp);
|
|
1280 if (DECL_P (decl) && DECL_NAME (decl))
|
|
1281 {
|
|
1282 pp_decimal_int (&asan_pp, IDENTIFIER_LENGTH (DECL_NAME (decl)));
|
|
1283 pp_space (&asan_pp);
|
|
1284 pp_tree_identifier (&asan_pp, DECL_NAME (decl));
|
|
1285 }
|
|
1286 else
|
|
1287 pp_string (&asan_pp, "9 <unknown>");
|
|
1288 pp_space (&asan_pp);
|
|
1289 }
|
|
1290 str_cst = asan_pp_string (&asan_pp);
|
|
1291
|
|
1292 /* Emit the prologue sequence. */
|
|
1293 if (asan_frame_size > 32 && asan_frame_size <= 65536 && pbase
|
|
1294 && ASAN_USE_AFTER_RETURN)
|
|
1295 {
|
|
1296 use_after_return_class = floor_log2 (asan_frame_size - 1) - 5;
|
|
1297 /* __asan_stack_malloc_N guarantees alignment
|
|
1298 N < 6 ? (64 << N) : 4096 bytes. */
|
|
1299 if (alignb > (use_after_return_class < 6
|
|
1300 ? (64U << use_after_return_class) : 4096U))
|
|
1301 use_after_return_class = -1;
|
|
1302 else if (alignb > ASAN_RED_ZONE_SIZE && (asan_frame_size & (alignb - 1)))
|
|
1303 base_align_bias = ((asan_frame_size + alignb - 1)
|
|
1304 & ~(alignb - HOST_WIDE_INT_1)) - asan_frame_size;
|
|
1305 }
|
|
1306 /* Align base if target is STRICT_ALIGNMENT. */
|
|
1307 if (STRICT_ALIGNMENT)
|
|
1308 base = expand_binop (Pmode, and_optab, base,
|
|
1309 gen_int_mode (-((GET_MODE_ALIGNMENT (SImode)
|
|
1310 << ASAN_SHADOW_SHIFT)
|
|
1311 / BITS_PER_UNIT), Pmode), NULL_RTX,
|
|
1312 1, OPTAB_DIRECT);
|
|
1313
|
|
1314 if (use_after_return_class == -1 && pbase)
|
|
1315 emit_move_insn (pbase, base);
|
|
1316
|
|
1317 base = expand_binop (Pmode, add_optab, base,
|
|
1318 gen_int_mode (base_offset - base_align_bias, Pmode),
|
|
1319 NULL_RTX, 1, OPTAB_DIRECT);
|
|
1320 orig_base = NULL_RTX;
|
|
1321 if (use_after_return_class != -1)
|
|
1322 {
|
|
1323 if (asan_detect_stack_use_after_return == NULL_TREE)
|
|
1324 {
|
|
1325 id = get_identifier ("__asan_option_detect_stack_use_after_return");
|
|
1326 decl = build_decl (BUILTINS_LOCATION, VAR_DECL, id,
|
|
1327 integer_type_node);
|
|
1328 SET_DECL_ASSEMBLER_NAME (decl, id);
|
|
1329 TREE_ADDRESSABLE (decl) = 1;
|
|
1330 DECL_ARTIFICIAL (decl) = 1;
|
|
1331 DECL_IGNORED_P (decl) = 1;
|
|
1332 DECL_EXTERNAL (decl) = 1;
|
|
1333 TREE_STATIC (decl) = 1;
|
|
1334 TREE_PUBLIC (decl) = 1;
|
|
1335 TREE_USED (decl) = 1;
|
|
1336 asan_detect_stack_use_after_return = decl;
|
|
1337 }
|
|
1338 orig_base = gen_reg_rtx (Pmode);
|
|
1339 emit_move_insn (orig_base, base);
|
|
1340 ret = expand_normal (asan_detect_stack_use_after_return);
|
|
1341 lab = gen_label_rtx ();
|
|
1342 emit_cmp_and_jump_insns (ret, const0_rtx, EQ, NULL_RTX,
|
|
1343 VOIDmode, 0, lab,
|
|
1344 profile_probability::very_likely ());
|
|
1345 snprintf (buf, sizeof buf, "__asan_stack_malloc_%d",
|
|
1346 use_after_return_class);
|
|
1347 ret = init_one_libfunc (buf);
|
|
1348 ret = emit_library_call_value (ret, NULL_RTX, LCT_NORMAL, ptr_mode,
|
|
1349 GEN_INT (asan_frame_size
|
|
1350 + base_align_bias),
|
|
1351 TYPE_MODE (pointer_sized_int_node));
|
|
1352 /* __asan_stack_malloc_[n] returns a pointer to fake stack if succeeded
|
|
1353 and NULL otherwise. Check RET value is NULL here and jump over the
|
|
1354 BASE reassignment in this case. Otherwise, reassign BASE to RET. */
|
|
1355 emit_cmp_and_jump_insns (ret, const0_rtx, EQ, NULL_RTX,
|
|
1356 VOIDmode, 0, lab,
|
|
1357 profile_probability:: very_unlikely ());
|
|
1358 ret = convert_memory_address (Pmode, ret);
|
|
1359 emit_move_insn (base, ret);
|
|
1360 emit_label (lab);
|
|
1361 emit_move_insn (pbase, expand_binop (Pmode, add_optab, base,
|
|
1362 gen_int_mode (base_align_bias
|
|
1363 - base_offset, Pmode),
|
|
1364 NULL_RTX, 1, OPTAB_DIRECT));
|
|
1365 }
|
|
1366 mem = gen_rtx_MEM (ptr_mode, base);
|
|
1367 mem = adjust_address (mem, VOIDmode, base_align_bias);
|
|
1368 emit_move_insn (mem, gen_int_mode (ASAN_STACK_FRAME_MAGIC, ptr_mode));
|
|
1369 mem = adjust_address (mem, VOIDmode, GET_MODE_SIZE (ptr_mode));
|
|
1370 emit_move_insn (mem, expand_normal (str_cst));
|
|
1371 mem = adjust_address (mem, VOIDmode, GET_MODE_SIZE (ptr_mode));
|
|
1372 ASM_GENERATE_INTERNAL_LABEL (buf, "LASANPC", current_function_funcdef_no);
|
|
1373 id = get_identifier (buf);
|
|
1374 decl = build_decl (DECL_SOURCE_LOCATION (current_function_decl),
|
|
1375 VAR_DECL, id, char_type_node);
|
|
1376 SET_DECL_ASSEMBLER_NAME (decl, id);
|
|
1377 TREE_ADDRESSABLE (decl) = 1;
|
|
1378 TREE_READONLY (decl) = 1;
|
|
1379 DECL_ARTIFICIAL (decl) = 1;
|
|
1380 DECL_IGNORED_P (decl) = 1;
|
|
1381 TREE_STATIC (decl) = 1;
|
|
1382 TREE_PUBLIC (decl) = 0;
|
|
1383 TREE_USED (decl) = 1;
|
|
1384 DECL_INITIAL (decl) = decl;
|
|
1385 TREE_ASM_WRITTEN (decl) = 1;
|
|
1386 TREE_ASM_WRITTEN (id) = 1;
|
|
1387 emit_move_insn (mem, expand_normal (build_fold_addr_expr (decl)));
|
|
1388 shadow_base = expand_binop (Pmode, lshr_optab, base,
|
|
1389 GEN_INT (ASAN_SHADOW_SHIFT),
|
|
1390 NULL_RTX, 1, OPTAB_DIRECT);
|
|
1391 shadow_base
|
|
1392 = plus_constant (Pmode, shadow_base,
|
|
1393 asan_shadow_offset ()
|
|
1394 + (base_align_bias >> ASAN_SHADOW_SHIFT));
|
|
1395 gcc_assert (asan_shadow_set != -1
|
|
1396 && (ASAN_RED_ZONE_SIZE >> ASAN_SHADOW_SHIFT) == 4);
|
|
1397 shadow_mem = gen_rtx_MEM (SImode, shadow_base);
|
|
1398 set_mem_alias_set (shadow_mem, asan_shadow_set);
|
|
1399 if (STRICT_ALIGNMENT)
|
|
1400 set_mem_align (shadow_mem, (GET_MODE_ALIGNMENT (SImode)));
|
|
1401 prev_offset = base_offset;
|
|
1402 for (l = length; l; l -= 2)
|
|
1403 {
|
|
1404 if (l == 2)
|
|
1405 cur_shadow_byte = ASAN_STACK_MAGIC_RIGHT;
|
|
1406 offset = offsets[l - 1];
|
|
1407 if ((offset - base_offset) & (ASAN_RED_ZONE_SIZE - 1))
|
|
1408 {
|
|
1409 int i;
|
|
1410 HOST_WIDE_INT aoff
|
|
1411 = base_offset + ((offset - base_offset)
|
|
1412 & ~(ASAN_RED_ZONE_SIZE - HOST_WIDE_INT_1));
|
|
1413 shadow_mem = adjust_address (shadow_mem, VOIDmode,
|
|
1414 (aoff - prev_offset)
|
|
1415 >> ASAN_SHADOW_SHIFT);
|
|
1416 prev_offset = aoff;
|
|
1417 for (i = 0; i < 4; i++, aoff += ASAN_SHADOW_GRANULARITY)
|
|
1418 if (aoff < offset)
|
|
1419 {
|
|
1420 if (aoff < offset - (HOST_WIDE_INT)ASAN_SHADOW_GRANULARITY + 1)
|
|
1421 shadow_bytes[i] = 0;
|
|
1422 else
|
|
1423 shadow_bytes[i] = offset - aoff;
|
|
1424 }
|
|
1425 else
|
|
1426 shadow_bytes[i] = ASAN_STACK_MAGIC_MIDDLE;
|
|
1427 emit_move_insn (shadow_mem, asan_shadow_cst (shadow_bytes));
|
|
1428 offset = aoff;
|
|
1429 }
|
|
1430 while (offset <= offsets[l - 2] - ASAN_RED_ZONE_SIZE)
|
|
1431 {
|
|
1432 shadow_mem = adjust_address (shadow_mem, VOIDmode,
|
|
1433 (offset - prev_offset)
|
|
1434 >> ASAN_SHADOW_SHIFT);
|
|
1435 prev_offset = offset;
|
|
1436 memset (shadow_bytes, cur_shadow_byte, 4);
|
|
1437 emit_move_insn (shadow_mem, asan_shadow_cst (shadow_bytes));
|
|
1438 offset += ASAN_RED_ZONE_SIZE;
|
|
1439 }
|
|
1440 cur_shadow_byte = ASAN_STACK_MAGIC_MIDDLE;
|
|
1441 }
|
|
1442 do_pending_stack_adjust ();
|
|
1443
|
|
1444 /* Construct epilogue sequence. */
|
|
1445 start_sequence ();
|
|
1446
|
|
1447 lab = NULL;
|
|
1448 if (use_after_return_class != -1)
|
|
1449 {
|
|
1450 rtx_code_label *lab2 = gen_label_rtx ();
|
|
1451 char c = (char) ASAN_STACK_MAGIC_USE_AFTER_RET;
|
|
1452 emit_cmp_and_jump_insns (orig_base, base, EQ, NULL_RTX,
|
|
1453 VOIDmode, 0, lab2,
|
|
1454 profile_probability::very_likely ());
|
|
1455 shadow_mem = gen_rtx_MEM (BLKmode, shadow_base);
|
|
1456 set_mem_alias_set (shadow_mem, asan_shadow_set);
|
|
1457 mem = gen_rtx_MEM (ptr_mode, base);
|
|
1458 mem = adjust_address (mem, VOIDmode, base_align_bias);
|
|
1459 emit_move_insn (mem, gen_int_mode (ASAN_STACK_RETIRED_MAGIC, ptr_mode));
|
|
1460 unsigned HOST_WIDE_INT sz = asan_frame_size >> ASAN_SHADOW_SHIFT;
|
|
1461 if (use_after_return_class < 5
|
|
1462 && can_store_by_pieces (sz, builtin_memset_read_str, &c,
|
|
1463 BITS_PER_UNIT, true))
|
|
1464 store_by_pieces (shadow_mem, sz, builtin_memset_read_str, &c,
|
|
1465 BITS_PER_UNIT, true, 0);
|
|
1466 else if (use_after_return_class >= 5
|
|
1467 || !set_storage_via_setmem (shadow_mem,
|
|
1468 GEN_INT (sz),
|
|
1469 gen_int_mode (c, QImode),
|
|
1470 BITS_PER_UNIT, BITS_PER_UNIT,
|
|
1471 -1, sz, sz, sz))
|
|
1472 {
|
|
1473 snprintf (buf, sizeof buf, "__asan_stack_free_%d",
|
|
1474 use_after_return_class);
|
|
1475 ret = init_one_libfunc (buf);
|
|
1476 rtx addr = convert_memory_address (ptr_mode, base);
|
|
1477 rtx orig_addr = convert_memory_address (ptr_mode, orig_base);
|
|
1478 emit_library_call (ret, LCT_NORMAL, ptr_mode, addr, ptr_mode,
|
|
1479 GEN_INT (asan_frame_size + base_align_bias),
|
|
1480 TYPE_MODE (pointer_sized_int_node),
|
|
1481 orig_addr, ptr_mode);
|
|
1482 }
|
|
1483 lab = gen_label_rtx ();
|
|
1484 emit_jump (lab);
|
|
1485 emit_label (lab2);
|
|
1486 }
|
|
1487
|
|
1488 shadow_mem = gen_rtx_MEM (BLKmode, shadow_base);
|
|
1489 set_mem_alias_set (shadow_mem, asan_shadow_set);
|
|
1490
|
|
1491 if (STRICT_ALIGNMENT)
|
|
1492 set_mem_align (shadow_mem, (GET_MODE_ALIGNMENT (SImode)));
|
|
1493
|
|
1494 prev_offset = base_offset;
|
|
1495 last_offset = base_offset;
|
|
1496 last_size = 0;
|
|
1497 for (l = length; l; l -= 2)
|
|
1498 {
|
|
1499 offset = base_offset + ((offsets[l - 1] - base_offset)
|
|
1500 & ~(ASAN_RED_ZONE_SIZE - HOST_WIDE_INT_1));
|
|
1501 if (last_offset + last_size != offset)
|
|
1502 {
|
|
1503 shadow_mem = adjust_address (shadow_mem, VOIDmode,
|
|
1504 (last_offset - prev_offset)
|
|
1505 >> ASAN_SHADOW_SHIFT);
|
|
1506 prev_offset = last_offset;
|
|
1507 asan_clear_shadow (shadow_mem, last_size >> ASAN_SHADOW_SHIFT);
|
|
1508 last_offset = offset;
|
|
1509 last_size = 0;
|
|
1510 }
|
|
1511 last_size += base_offset + ((offsets[l - 2] - base_offset)
|
|
1512 & ~(ASAN_RED_ZONE_SIZE - HOST_WIDE_INT_1))
|
|
1513 - offset;
|
|
1514
|
|
1515 /* Unpoison shadow memory that corresponds to a variable that is
|
|
1516 is subject of use-after-return sanitization. */
|
|
1517 if (l > 2)
|
|
1518 {
|
|
1519 decl = decls[l / 2 - 2];
|
|
1520 if (asan_handled_variables != NULL
|
|
1521 && asan_handled_variables->contains (decl))
|
|
1522 {
|
|
1523 HOST_WIDE_INT size = offsets[l - 3] - offsets[l - 2];
|
|
1524 if (dump_file && (dump_flags & TDF_DETAILS))
|
|
1525 {
|
|
1526 const char *n = (DECL_NAME (decl)
|
|
1527 ? IDENTIFIER_POINTER (DECL_NAME (decl))
|
|
1528 : "<unknown>");
|
|
1529 fprintf (dump_file, "Unpoisoning shadow stack for variable: "
|
|
1530 "%s (%" PRId64 " B)\n", n, size);
|
|
1531 }
|
|
1532
|
|
1533 last_size += size & ~(ASAN_RED_ZONE_SIZE - HOST_WIDE_INT_1);
|
|
1534 }
|
|
1535 }
|
|
1536 }
|
|
1537 if (last_size)
|
|
1538 {
|
|
1539 shadow_mem = adjust_address (shadow_mem, VOIDmode,
|
|
1540 (last_offset - prev_offset)
|
|
1541 >> ASAN_SHADOW_SHIFT);
|
|
1542 asan_clear_shadow (shadow_mem, last_size >> ASAN_SHADOW_SHIFT);
|
|
1543 }
|
|
1544
|
|
1545 /* Clean-up set with instrumented stack variables. */
|
|
1546 delete asan_handled_variables;
|
|
1547 asan_handled_variables = NULL;
|
|
1548 delete asan_used_labels;
|
|
1549 asan_used_labels = NULL;
|
|
1550
|
|
1551 do_pending_stack_adjust ();
|
|
1552 if (lab)
|
|
1553 emit_label (lab);
|
|
1554
|
|
1555 insns = get_insns ();
|
|
1556 end_sequence ();
|
|
1557 return insns;
|
|
1558 }
|
|
1559
|
|
1560 /* Emit __asan_allocas_unpoison (top, bot) call. The BASE parameter corresponds
|
|
1561 to BOT argument, for TOP virtual_stack_dynamic_rtx is used. NEW_SEQUENCE
|
|
1562 indicates whether we're emitting new instructions sequence or not. */
|
|
1563
|
|
1564 rtx_insn *
|
|
1565 asan_emit_allocas_unpoison (rtx top, rtx bot, rtx_insn *before)
|
|
1566 {
|
|
1567 if (before)
|
|
1568 push_to_sequence (before);
|
|
1569 else
|
|
1570 start_sequence ();
|
|
1571 rtx ret = init_one_libfunc ("__asan_allocas_unpoison");
|
|
1572 top = convert_memory_address (ptr_mode, top);
|
|
1573 bot = convert_memory_address (ptr_mode, bot);
|
|
1574 ret = emit_library_call_value (ret, NULL_RTX, LCT_NORMAL, ptr_mode,
|
|
1575 top, ptr_mode, bot, ptr_mode);
|
|
1576
|
|
1577 do_pending_stack_adjust ();
|
|
1578 rtx_insn *insns = get_insns ();
|
|
1579 end_sequence ();
|
|
1580 return insns;
|
|
1581 }
|
|
1582
|
|
1583 /* Return true if DECL, a global var, might be overridden and needs
|
|
1584 therefore a local alias. */
|
|
1585
|
|
1586 static bool
|
|
1587 asan_needs_local_alias (tree decl)
|
|
1588 {
|
|
1589 return DECL_WEAK (decl) || !targetm.binds_local_p (decl);
|
|
1590 }
|
|
1591
|
|
1592 /* Return true if DECL, a global var, is an artificial ODR indicator symbol
|
|
1593 therefore doesn't need protection. */
|
|
1594
|
|
1595 static bool
|
|
1596 is_odr_indicator (tree decl)
|
|
1597 {
|
|
1598 return (DECL_ARTIFICIAL (decl)
|
|
1599 && lookup_attribute ("asan odr indicator", DECL_ATTRIBUTES (decl)));
|
|
1600 }
|
|
1601
|
|
1602 /* Return true if DECL is a VAR_DECL that should be protected
|
|
1603 by Address Sanitizer, by appending a red zone with protected
|
|
1604 shadow memory after it and aligning it to at least
|
|
1605 ASAN_RED_ZONE_SIZE bytes. */
|
|
1606
|
|
1607 bool
|
|
1608 asan_protect_global (tree decl)
|
|
1609 {
|
|
1610 if (!ASAN_GLOBALS)
|
|
1611 return false;
|
|
1612
|
|
1613 rtx rtl, symbol;
|
|
1614
|
|
1615 if (TREE_CODE (decl) == STRING_CST)
|
|
1616 {
|
|
1617 /* Instrument all STRING_CSTs except those created
|
|
1618 by asan_pp_string here. */
|
|
1619 if (shadow_ptr_types[0] != NULL_TREE
|
|
1620 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
|
|
1621 && TREE_TYPE (TREE_TYPE (decl)) == TREE_TYPE (shadow_ptr_types[0]))
|
|
1622 return false;
|
|
1623 return true;
|
|
1624 }
|
|
1625 if (!VAR_P (decl)
|
|
1626 /* TLS vars aren't statically protectable. */
|
|
1627 || DECL_THREAD_LOCAL_P (decl)
|
|
1628 /* Externs will be protected elsewhere. */
|
|
1629 || DECL_EXTERNAL (decl)
|
|
1630 || !DECL_RTL_SET_P (decl)
|
|
1631 /* Comdat vars pose an ABI problem, we can't know if
|
|
1632 the var that is selected by the linker will have
|
|
1633 padding or not. */
|
|
1634 || DECL_ONE_ONLY (decl)
|
|
1635 /* Similarly for common vars. People can use -fno-common.
|
|
1636 Note: Linux kernel is built with -fno-common, so we do instrument
|
|
1637 globals there even if it is C. */
|
|
1638 || (DECL_COMMON (decl) && TREE_PUBLIC (decl))
|
|
1639 /* Don't protect if using user section, often vars placed
|
|
1640 into user section from multiple TUs are then assumed
|
|
1641 to be an array of such vars, putting padding in there
|
|
1642 breaks this assumption. */
|
|
1643 || (DECL_SECTION_NAME (decl) != NULL
|
|
1644 && !symtab_node::get (decl)->implicit_section
|
|
1645 && !section_sanitized_p (DECL_SECTION_NAME (decl)))
|
|
1646 || DECL_SIZE (decl) == 0
|
|
1647 || ASAN_RED_ZONE_SIZE * BITS_PER_UNIT > MAX_OFILE_ALIGNMENT
|
|
1648 || !valid_constant_size_p (DECL_SIZE_UNIT (decl))
|
|
1649 || DECL_ALIGN_UNIT (decl) > 2 * ASAN_RED_ZONE_SIZE
|
|
1650 || TREE_TYPE (decl) == ubsan_get_source_location_type ()
|
|
1651 || is_odr_indicator (decl))
|
|
1652 return false;
|
|
1653
|
|
1654 rtl = DECL_RTL (decl);
|
|
1655 if (!MEM_P (rtl) || GET_CODE (XEXP (rtl, 0)) != SYMBOL_REF)
|
|
1656 return false;
|
|
1657 symbol = XEXP (rtl, 0);
|
|
1658
|
|
1659 if (CONSTANT_POOL_ADDRESS_P (symbol)
|
|
1660 || TREE_CONSTANT_POOL_ADDRESS_P (symbol))
|
|
1661 return false;
|
|
1662
|
|
1663 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
|
|
1664 return false;
|
|
1665
|
|
1666 if (!TARGET_SUPPORTS_ALIASES && asan_needs_local_alias (decl))
|
|
1667 return false;
|
|
1668
|
|
1669 return true;
|
|
1670 }
|
|
1671
|
|
1672 /* Construct a function tree for __asan_report_{load,store}{1,2,4,8,16,_n}.
|
|
1673 IS_STORE is either 1 (for a store) or 0 (for a load). */
|
|
1674
|
|
1675 static tree
|
|
1676 report_error_func (bool is_store, bool recover_p, HOST_WIDE_INT size_in_bytes,
|
|
1677 int *nargs)
|
|
1678 {
|
|
1679 static enum built_in_function report[2][2][6]
|
|
1680 = { { { BUILT_IN_ASAN_REPORT_LOAD1, BUILT_IN_ASAN_REPORT_LOAD2,
|
|
1681 BUILT_IN_ASAN_REPORT_LOAD4, BUILT_IN_ASAN_REPORT_LOAD8,
|
|
1682 BUILT_IN_ASAN_REPORT_LOAD16, BUILT_IN_ASAN_REPORT_LOAD_N },
|
|
1683 { BUILT_IN_ASAN_REPORT_STORE1, BUILT_IN_ASAN_REPORT_STORE2,
|
|
1684 BUILT_IN_ASAN_REPORT_STORE4, BUILT_IN_ASAN_REPORT_STORE8,
|
|
1685 BUILT_IN_ASAN_REPORT_STORE16, BUILT_IN_ASAN_REPORT_STORE_N } },
|
|
1686 { { BUILT_IN_ASAN_REPORT_LOAD1_NOABORT,
|
|
1687 BUILT_IN_ASAN_REPORT_LOAD2_NOABORT,
|
|
1688 BUILT_IN_ASAN_REPORT_LOAD4_NOABORT,
|
|
1689 BUILT_IN_ASAN_REPORT_LOAD8_NOABORT,
|
|
1690 BUILT_IN_ASAN_REPORT_LOAD16_NOABORT,
|
|
1691 BUILT_IN_ASAN_REPORT_LOAD_N_NOABORT },
|
|
1692 { BUILT_IN_ASAN_REPORT_STORE1_NOABORT,
|
|
1693 BUILT_IN_ASAN_REPORT_STORE2_NOABORT,
|
|
1694 BUILT_IN_ASAN_REPORT_STORE4_NOABORT,
|
|
1695 BUILT_IN_ASAN_REPORT_STORE8_NOABORT,
|
|
1696 BUILT_IN_ASAN_REPORT_STORE16_NOABORT,
|
|
1697 BUILT_IN_ASAN_REPORT_STORE_N_NOABORT } } };
|
|
1698 if (size_in_bytes == -1)
|
|
1699 {
|
|
1700 *nargs = 2;
|
|
1701 return builtin_decl_implicit (report[recover_p][is_store][5]);
|
|
1702 }
|
|
1703 *nargs = 1;
|
|
1704 int size_log2 = exact_log2 (size_in_bytes);
|
|
1705 return builtin_decl_implicit (report[recover_p][is_store][size_log2]);
|
|
1706 }
|
|
1707
|
|
1708 /* Construct a function tree for __asan_{load,store}{1,2,4,8,16,_n}.
|
|
1709 IS_STORE is either 1 (for a store) or 0 (for a load). */
|
|
1710
|
|
1711 static tree
|
|
1712 check_func (bool is_store, bool recover_p, HOST_WIDE_INT size_in_bytes,
|
|
1713 int *nargs)
|
|
1714 {
|
|
1715 static enum built_in_function check[2][2][6]
|
|
1716 = { { { BUILT_IN_ASAN_LOAD1, BUILT_IN_ASAN_LOAD2,
|
|
1717 BUILT_IN_ASAN_LOAD4, BUILT_IN_ASAN_LOAD8,
|
|
1718 BUILT_IN_ASAN_LOAD16, BUILT_IN_ASAN_LOADN },
|
|
1719 { BUILT_IN_ASAN_STORE1, BUILT_IN_ASAN_STORE2,
|
|
1720 BUILT_IN_ASAN_STORE4, BUILT_IN_ASAN_STORE8,
|
|
1721 BUILT_IN_ASAN_STORE16, BUILT_IN_ASAN_STOREN } },
|
|
1722 { { BUILT_IN_ASAN_LOAD1_NOABORT,
|
|
1723 BUILT_IN_ASAN_LOAD2_NOABORT,
|
|
1724 BUILT_IN_ASAN_LOAD4_NOABORT,
|
|
1725 BUILT_IN_ASAN_LOAD8_NOABORT,
|
|
1726 BUILT_IN_ASAN_LOAD16_NOABORT,
|
|
1727 BUILT_IN_ASAN_LOADN_NOABORT },
|
|
1728 { BUILT_IN_ASAN_STORE1_NOABORT,
|
|
1729 BUILT_IN_ASAN_STORE2_NOABORT,
|
|
1730 BUILT_IN_ASAN_STORE4_NOABORT,
|
|
1731 BUILT_IN_ASAN_STORE8_NOABORT,
|
|
1732 BUILT_IN_ASAN_STORE16_NOABORT,
|
|
1733 BUILT_IN_ASAN_STOREN_NOABORT } } };
|
|
1734 if (size_in_bytes == -1)
|
|
1735 {
|
|
1736 *nargs = 2;
|
|
1737 return builtin_decl_implicit (check[recover_p][is_store][5]);
|
|
1738 }
|
|
1739 *nargs = 1;
|
|
1740 int size_log2 = exact_log2 (size_in_bytes);
|
|
1741 return builtin_decl_implicit (check[recover_p][is_store][size_log2]);
|
|
1742 }
|
|
1743
|
|
1744 /* Split the current basic block and create a condition statement
|
|
1745 insertion point right before or after the statement pointed to by
|
|
1746 ITER. Return an iterator to the point at which the caller might
|
|
1747 safely insert the condition statement.
|
|
1748
|
|
1749 THEN_BLOCK must be set to the address of an uninitialized instance
|
|
1750 of basic_block. The function will then set *THEN_BLOCK to the
|
|
1751 'then block' of the condition statement to be inserted by the
|
|
1752 caller.
|
|
1753
|
|
1754 If CREATE_THEN_FALLTHRU_EDGE is false, no edge will be created from
|
|
1755 *THEN_BLOCK to *FALLTHROUGH_BLOCK.
|
|
1756
|
|
1757 Similarly, the function will set *FALLTRHOUGH_BLOCK to the 'else
|
|
1758 block' of the condition statement to be inserted by the caller.
|
|
1759
|
|
1760 Note that *FALLTHROUGH_BLOCK is a new block that contains the
|
|
1761 statements starting from *ITER, and *THEN_BLOCK is a new empty
|
|
1762 block.
|
|
1763
|
|
1764 *ITER is adjusted to point to always point to the first statement
|
|
1765 of the basic block * FALLTHROUGH_BLOCK. That statement is the
|
|
1766 same as what ITER was pointing to prior to calling this function,
|
|
1767 if BEFORE_P is true; otherwise, it is its following statement. */
|
|
1768
|
|
1769 gimple_stmt_iterator
|
|
1770 create_cond_insert_point (gimple_stmt_iterator *iter,
|
|
1771 bool before_p,
|
|
1772 bool then_more_likely_p,
|
|
1773 bool create_then_fallthru_edge,
|
|
1774 basic_block *then_block,
|
|
1775 basic_block *fallthrough_block)
|
|
1776 {
|
|
1777 gimple_stmt_iterator gsi = *iter;
|
|
1778
|
|
1779 if (!gsi_end_p (gsi) && before_p)
|
|
1780 gsi_prev (&gsi);
|
|
1781
|
|
1782 basic_block cur_bb = gsi_bb (*iter);
|
|
1783
|
|
1784 edge e = split_block (cur_bb, gsi_stmt (gsi));
|
|
1785
|
|
1786 /* Get a hold on the 'condition block', the 'then block' and the
|
|
1787 'else block'. */
|
|
1788 basic_block cond_bb = e->src;
|
|
1789 basic_block fallthru_bb = e->dest;
|
|
1790 basic_block then_bb = create_empty_bb (cond_bb);
|
|
1791 if (current_loops)
|
|
1792 {
|
|
1793 add_bb_to_loop (then_bb, cond_bb->loop_father);
|
|
1794 loops_state_set (LOOPS_NEED_FIXUP);
|
|
1795 }
|
|
1796
|
|
1797 /* Set up the newly created 'then block'. */
|
|
1798 e = make_edge (cond_bb, then_bb, EDGE_TRUE_VALUE);
|
|
1799 profile_probability fallthrough_probability
|
|
1800 = then_more_likely_p
|
|
1801 ? profile_probability::very_unlikely ()
|
|
1802 : profile_probability::very_likely ();
|
|
1803 e->probability = fallthrough_probability.invert ();
|
|
1804 if (create_then_fallthru_edge)
|
|
1805 make_single_succ_edge (then_bb, fallthru_bb, EDGE_FALLTHRU);
|
|
1806
|
|
1807 /* Set up the fallthrough basic block. */
|
|
1808 e = find_edge (cond_bb, fallthru_bb);
|
|
1809 e->flags = EDGE_FALSE_VALUE;
|
|
1810 e->probability = fallthrough_probability;
|
|
1811
|
|
1812 /* Update dominance info for the newly created then_bb; note that
|
|
1813 fallthru_bb's dominance info has already been updated by
|
|
1814 split_bock. */
|
|
1815 if (dom_info_available_p (CDI_DOMINATORS))
|
|
1816 set_immediate_dominator (CDI_DOMINATORS, then_bb, cond_bb);
|
|
1817
|
|
1818 *then_block = then_bb;
|
|
1819 *fallthrough_block = fallthru_bb;
|
|
1820 *iter = gsi_start_bb (fallthru_bb);
|
|
1821
|
|
1822 return gsi_last_bb (cond_bb);
|
|
1823 }
|
|
1824
|
|
1825 /* Insert an if condition followed by a 'then block' right before the
|
|
1826 statement pointed to by ITER. The fallthrough block -- which is the
|
|
1827 else block of the condition as well as the destination of the
|
|
1828 outcoming edge of the 'then block' -- starts with the statement
|
|
1829 pointed to by ITER.
|
|
1830
|
|
1831 COND is the condition of the if.
|
|
1832
|
|
1833 If THEN_MORE_LIKELY_P is true, the probability of the edge to the
|
|
1834 'then block' is higher than the probability of the edge to the
|
|
1835 fallthrough block.
|
|
1836
|
|
1837 Upon completion of the function, *THEN_BB is set to the newly
|
|
1838 inserted 'then block' and similarly, *FALLTHROUGH_BB is set to the
|
|
1839 fallthrough block.
|
|
1840
|
|
1841 *ITER is adjusted to still point to the same statement it was
|
|
1842 pointing to initially. */
|
|
1843
|
|
1844 static void
|
|
1845 insert_if_then_before_iter (gcond *cond,
|
|
1846 gimple_stmt_iterator *iter,
|
|
1847 bool then_more_likely_p,
|
|
1848 basic_block *then_bb,
|
|
1849 basic_block *fallthrough_bb)
|
|
1850 {
|
|
1851 gimple_stmt_iterator cond_insert_point =
|
|
1852 create_cond_insert_point (iter,
|
|
1853 /*before_p=*/true,
|
|
1854 then_more_likely_p,
|
|
1855 /*create_then_fallthru_edge=*/true,
|
|
1856 then_bb,
|
|
1857 fallthrough_bb);
|
|
1858 gsi_insert_after (&cond_insert_point, cond, GSI_NEW_STMT);
|
|
1859 }
|
|
1860
|
|
1861 /* Build (base_addr >> ASAN_SHADOW_SHIFT) + asan_shadow_offset ().
|
|
1862 If RETURN_ADDRESS is set to true, return memory location instread
|
|
1863 of a value in the shadow memory. */
|
|
1864
|
|
1865 static tree
|
|
1866 build_shadow_mem_access (gimple_stmt_iterator *gsi, location_t location,
|
|
1867 tree base_addr, tree shadow_ptr_type,
|
|
1868 bool return_address = false)
|
|
1869 {
|
|
1870 tree t, uintptr_type = TREE_TYPE (base_addr);
|
|
1871 tree shadow_type = TREE_TYPE (shadow_ptr_type);
|
|
1872 gimple *g;
|
|
1873
|
|
1874 t = build_int_cst (uintptr_type, ASAN_SHADOW_SHIFT);
|
|
1875 g = gimple_build_assign (make_ssa_name (uintptr_type), RSHIFT_EXPR,
|
|
1876 base_addr, t);
|
|
1877 gimple_set_location (g, location);
|
|
1878 gsi_insert_after (gsi, g, GSI_NEW_STMT);
|
|
1879
|
|
1880 t = build_int_cst (uintptr_type, asan_shadow_offset ());
|
|
1881 g = gimple_build_assign (make_ssa_name (uintptr_type), PLUS_EXPR,
|
|
1882 gimple_assign_lhs (g), t);
|
|
1883 gimple_set_location (g, location);
|
|
1884 gsi_insert_after (gsi, g, GSI_NEW_STMT);
|
|
1885
|
|
1886 g = gimple_build_assign (make_ssa_name (shadow_ptr_type), NOP_EXPR,
|
|
1887 gimple_assign_lhs (g));
|
|
1888 gimple_set_location (g, location);
|
|
1889 gsi_insert_after (gsi, g, GSI_NEW_STMT);
|
|
1890
|
|
1891 if (!return_address)
|
|
1892 {
|
|
1893 t = build2 (MEM_REF, shadow_type, gimple_assign_lhs (g),
|
|
1894 build_int_cst (shadow_ptr_type, 0));
|
|
1895 g = gimple_build_assign (make_ssa_name (shadow_type), MEM_REF, t);
|
|
1896 gimple_set_location (g, location);
|
|
1897 gsi_insert_after (gsi, g, GSI_NEW_STMT);
|
|
1898 }
|
|
1899
|
|
1900 return gimple_assign_lhs (g);
|
|
1901 }
|
|
1902
|
|
1903 /* BASE can already be an SSA_NAME; in that case, do not create a
|
|
1904 new SSA_NAME for it. */
|
|
1905
|
|
1906 static tree
|
|
1907 maybe_create_ssa_name (location_t loc, tree base, gimple_stmt_iterator *iter,
|
|
1908 bool before_p)
|
|
1909 {
|
|
1910 if (TREE_CODE (base) == SSA_NAME)
|
|
1911 return base;
|
|
1912 gimple *g = gimple_build_assign (make_ssa_name (TREE_TYPE (base)),
|
|
1913 TREE_CODE (base), base);
|
|
1914 gimple_set_location (g, loc);
|
|
1915 if (before_p)
|
|
1916 gsi_insert_before (iter, g, GSI_SAME_STMT);
|
|
1917 else
|
|
1918 gsi_insert_after (iter, g, GSI_NEW_STMT);
|
|
1919 return gimple_assign_lhs (g);
|
|
1920 }
|
|
1921
|
|
1922 /* LEN can already have necessary size and precision;
|
|
1923 in that case, do not create a new variable. */
|
|
1924
|
|
1925 tree
|
|
1926 maybe_cast_to_ptrmode (location_t loc, tree len, gimple_stmt_iterator *iter,
|
|
1927 bool before_p)
|
|
1928 {
|
|
1929 if (ptrofftype_p (len))
|
|
1930 return len;
|
|
1931 gimple *g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
|
|
1932 NOP_EXPR, len);
|
|
1933 gimple_set_location (g, loc);
|
|
1934 if (before_p)
|
|
1935 gsi_insert_before (iter, g, GSI_SAME_STMT);
|
|
1936 else
|
|
1937 gsi_insert_after (iter, g, GSI_NEW_STMT);
|
|
1938 return gimple_assign_lhs (g);
|
|
1939 }
|
|
1940
|
|
1941 /* Instrument the memory access instruction BASE. Insert new
|
|
1942 statements before or after ITER.
|
|
1943
|
|
1944 Note that the memory access represented by BASE can be either an
|
|
1945 SSA_NAME, or a non-SSA expression. LOCATION is the source code
|
|
1946 location. IS_STORE is TRUE for a store, FALSE for a load.
|
|
1947 BEFORE_P is TRUE for inserting the instrumentation code before
|
|
1948 ITER, FALSE for inserting it after ITER. IS_SCALAR_ACCESS is TRUE
|
|
1949 for a scalar memory access and FALSE for memory region access.
|
|
1950 NON_ZERO_P is TRUE if memory region is guaranteed to have non-zero
|
|
1951 length. ALIGN tells alignment of accessed memory object.
|
|
1952
|
|
1953 START_INSTRUMENTED and END_INSTRUMENTED are TRUE if start/end of
|
|
1954 memory region have already been instrumented.
|
|
1955
|
|
1956 If BEFORE_P is TRUE, *ITER is arranged to still point to the
|
|
1957 statement it was pointing to prior to calling this function,
|
|
1958 otherwise, it points to the statement logically following it. */
|
|
1959
|
|
1960 static void
|
|
1961 build_check_stmt (location_t loc, tree base, tree len,
|
|
1962 HOST_WIDE_INT size_in_bytes, gimple_stmt_iterator *iter,
|
|
1963 bool is_non_zero_len, bool before_p, bool is_store,
|
|
1964 bool is_scalar_access, unsigned int align = 0)
|
|
1965 {
|
|
1966 gimple_stmt_iterator gsi = *iter;
|
|
1967 gimple *g;
|
|
1968
|
|
1969 gcc_assert (!(size_in_bytes > 0 && !is_non_zero_len));
|
|
1970
|
|
1971 gsi = *iter;
|
|
1972
|
|
1973 base = unshare_expr (base);
|
|
1974 base = maybe_create_ssa_name (loc, base, &gsi, before_p);
|
|
1975
|
|
1976 if (len)
|
|
1977 {
|
|
1978 len = unshare_expr (len);
|
|
1979 len = maybe_cast_to_ptrmode (loc, len, iter, before_p);
|
|
1980 }
|
|
1981 else
|
|
1982 {
|
|
1983 gcc_assert (size_in_bytes != -1);
|
|
1984 len = build_int_cst (pointer_sized_int_node, size_in_bytes);
|
|
1985 }
|
|
1986
|
|
1987 if (size_in_bytes > 1)
|
|
1988 {
|
|
1989 if ((size_in_bytes & (size_in_bytes - 1)) != 0
|
|
1990 || size_in_bytes > 16)
|
|
1991 is_scalar_access = false;
|
|
1992 else if (align && align < size_in_bytes * BITS_PER_UNIT)
|
|
1993 {
|
|
1994 /* On non-strict alignment targets, if
|
|
1995 16-byte access is just 8-byte aligned,
|
|
1996 this will result in misaligned shadow
|
|
1997 memory 2 byte load, but otherwise can
|
|
1998 be handled using one read. */
|
|
1999 if (size_in_bytes != 16
|
|
2000 || STRICT_ALIGNMENT
|
|
2001 || align < 8 * BITS_PER_UNIT)
|
|
2002 is_scalar_access = false;
|
|
2003 }
|
|
2004 }
|
|
2005
|
|
2006 HOST_WIDE_INT flags = 0;
|
|
2007 if (is_store)
|
|
2008 flags |= ASAN_CHECK_STORE;
|
|
2009 if (is_non_zero_len)
|
|
2010 flags |= ASAN_CHECK_NON_ZERO_LEN;
|
|
2011 if (is_scalar_access)
|
|
2012 flags |= ASAN_CHECK_SCALAR_ACCESS;
|
|
2013
|
|
2014 g = gimple_build_call_internal (IFN_ASAN_CHECK, 4,
|
|
2015 build_int_cst (integer_type_node, flags),
|
|
2016 base, len,
|
|
2017 build_int_cst (integer_type_node,
|
|
2018 align / BITS_PER_UNIT));
|
|
2019 gimple_set_location (g, loc);
|
|
2020 if (before_p)
|
|
2021 gsi_insert_before (&gsi, g, GSI_SAME_STMT);
|
|
2022 else
|
|
2023 {
|
|
2024 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
|
|
2025 gsi_next (&gsi);
|
|
2026 *iter = gsi;
|
|
2027 }
|
|
2028 }
|
|
2029
|
|
2030 /* If T represents a memory access, add instrumentation code before ITER.
|
|
2031 LOCATION is source code location.
|
|
2032 IS_STORE is either TRUE (for a store) or FALSE (for a load). */
|
|
2033
|
|
2034 static void
|
|
2035 instrument_derefs (gimple_stmt_iterator *iter, tree t,
|
|
2036 location_t location, bool is_store)
|
|
2037 {
|
|
2038 if (is_store && !ASAN_INSTRUMENT_WRITES)
|
|
2039 return;
|
|
2040 if (!is_store && !ASAN_INSTRUMENT_READS)
|
|
2041 return;
|
|
2042
|
|
2043 tree type, base;
|
|
2044 HOST_WIDE_INT size_in_bytes;
|
|
2045 if (location == UNKNOWN_LOCATION)
|
|
2046 location = EXPR_LOCATION (t);
|
|
2047
|
|
2048 type = TREE_TYPE (t);
|
|
2049 switch (TREE_CODE (t))
|
|
2050 {
|
|
2051 case ARRAY_REF:
|
|
2052 case COMPONENT_REF:
|
|
2053 case INDIRECT_REF:
|
|
2054 case MEM_REF:
|
|
2055 case VAR_DECL:
|
|
2056 case BIT_FIELD_REF:
|
|
2057 break;
|
|
2058 /* FALLTHRU */
|
|
2059 default:
|
|
2060 return;
|
|
2061 }
|
|
2062
|
|
2063 size_in_bytes = int_size_in_bytes (type);
|
|
2064 if (size_in_bytes <= 0)
|
|
2065 return;
|
|
2066
|
|
2067 HOST_WIDE_INT bitsize, bitpos;
|
|
2068 tree offset;
|
|
2069 machine_mode mode;
|
|
2070 int unsignedp, reversep, volatilep = 0;
|
|
2071 tree inner = get_inner_reference (t, &bitsize, &bitpos, &offset, &mode,
|
|
2072 &unsignedp, &reversep, &volatilep);
|
|
2073
|
|
2074 if (TREE_CODE (t) == COMPONENT_REF
|
|
2075 && DECL_BIT_FIELD_REPRESENTATIVE (TREE_OPERAND (t, 1)) != NULL_TREE)
|
|
2076 {
|
|
2077 tree repr = DECL_BIT_FIELD_REPRESENTATIVE (TREE_OPERAND (t, 1));
|
|
2078 instrument_derefs (iter, build3 (COMPONENT_REF, TREE_TYPE (repr),
|
|
2079 TREE_OPERAND (t, 0), repr,
|
|
2080 TREE_OPERAND (t, 2)),
|
|
2081 location, is_store);
|
|
2082 return;
|
|
2083 }
|
|
2084
|
|
2085 if (bitpos % BITS_PER_UNIT
|
|
2086 || bitsize != size_in_bytes * BITS_PER_UNIT)
|
|
2087 return;
|
|
2088
|
|
2089 if (VAR_P (inner) && DECL_HARD_REGISTER (inner))
|
|
2090 return;
|
|
2091
|
|
2092 if (VAR_P (inner)
|
|
2093 && offset == NULL_TREE
|
|
2094 && bitpos >= 0
|
|
2095 && DECL_SIZE (inner)
|
|
2096 && tree_fits_shwi_p (DECL_SIZE (inner))
|
|
2097 && bitpos + bitsize <= tree_to_shwi (DECL_SIZE (inner)))
|
|
2098 {
|
|
2099 if (DECL_THREAD_LOCAL_P (inner))
|
|
2100 return;
|
|
2101 if (!ASAN_GLOBALS && is_global_var (inner))
|
|
2102 return;
|
|
2103 if (!TREE_STATIC (inner))
|
|
2104 {
|
|
2105 /* Automatic vars in the current function will be always
|
|
2106 accessible. */
|
|
2107 if (decl_function_context (inner) == current_function_decl
|
|
2108 && (!asan_sanitize_use_after_scope ()
|
|
2109 || !TREE_ADDRESSABLE (inner)))
|
|
2110 return;
|
|
2111 }
|
|
2112 /* Always instrument external vars, they might be dynamically
|
|
2113 initialized. */
|
|
2114 else if (!DECL_EXTERNAL (inner))
|
|
2115 {
|
|
2116 /* For static vars if they are known not to be dynamically
|
|
2117 initialized, they will be always accessible. */
|
|
2118 varpool_node *vnode = varpool_node::get (inner);
|
|
2119 if (vnode && !vnode->dynamically_initialized)
|
|
2120 return;
|
|
2121 }
|
|
2122 }
|
|
2123
|
|
2124 base = build_fold_addr_expr (t);
|
|
2125 if (!has_mem_ref_been_instrumented (base, size_in_bytes))
|
|
2126 {
|
|
2127 unsigned int align = get_object_alignment (t);
|
|
2128 build_check_stmt (location, base, NULL_TREE, size_in_bytes, iter,
|
|
2129 /*is_non_zero_len*/size_in_bytes > 0, /*before_p=*/true,
|
|
2130 is_store, /*is_scalar_access*/true, align);
|
|
2131 update_mem_ref_hash_table (base, size_in_bytes);
|
|
2132 update_mem_ref_hash_table (t, size_in_bytes);
|
|
2133 }
|
|
2134
|
|
2135 }
|
|
2136
|
|
2137 /* Insert a memory reference into the hash table if access length
|
|
2138 can be determined in compile time. */
|
|
2139
|
|
2140 static void
|
|
2141 maybe_update_mem_ref_hash_table (tree base, tree len)
|
|
2142 {
|
|
2143 if (!POINTER_TYPE_P (TREE_TYPE (base))
|
|
2144 || !INTEGRAL_TYPE_P (TREE_TYPE (len)))
|
|
2145 return;
|
|
2146
|
|
2147 HOST_WIDE_INT size_in_bytes = tree_fits_shwi_p (len) ? tree_to_shwi (len) : -1;
|
|
2148
|
|
2149 if (size_in_bytes != -1)
|
|
2150 update_mem_ref_hash_table (base, size_in_bytes);
|
|
2151 }
|
|
2152
|
|
2153 /* Instrument an access to a contiguous memory region that starts at
|
|
2154 the address pointed to by BASE, over a length of LEN (expressed in
|
|
2155 the sizeof (*BASE) bytes). ITER points to the instruction before
|
|
2156 which the instrumentation instructions must be inserted. LOCATION
|
|
2157 is the source location that the instrumentation instructions must
|
|
2158 have. If IS_STORE is true, then the memory access is a store;
|
|
2159 otherwise, it's a load. */
|
|
2160
|
|
2161 static void
|
|
2162 instrument_mem_region_access (tree base, tree len,
|
|
2163 gimple_stmt_iterator *iter,
|
|
2164 location_t location, bool is_store)
|
|
2165 {
|
|
2166 if (!POINTER_TYPE_P (TREE_TYPE (base))
|
|
2167 || !INTEGRAL_TYPE_P (TREE_TYPE (len))
|
|
2168 || integer_zerop (len))
|
|
2169 return;
|
|
2170
|
|
2171 HOST_WIDE_INT size_in_bytes = tree_fits_shwi_p (len) ? tree_to_shwi (len) : -1;
|
|
2172
|
|
2173 if ((size_in_bytes == -1)
|
|
2174 || !has_mem_ref_been_instrumented (base, size_in_bytes))
|
|
2175 {
|
|
2176 build_check_stmt (location, base, len, size_in_bytes, iter,
|
|
2177 /*is_non_zero_len*/size_in_bytes > 0, /*before_p*/true,
|
|
2178 is_store, /*is_scalar_access*/false, /*align*/0);
|
|
2179 }
|
|
2180
|
|
2181 maybe_update_mem_ref_hash_table (base, len);
|
|
2182 *iter = gsi_for_stmt (gsi_stmt (*iter));
|
|
2183 }
|
|
2184
|
|
2185 /* Instrument the call to a built-in memory access function that is
|
|
2186 pointed to by the iterator ITER.
|
|
2187
|
|
2188 Upon completion, return TRUE iff *ITER has been advanced to the
|
|
2189 statement following the one it was originally pointing to. */
|
|
2190
|
|
2191 static bool
|
|
2192 instrument_builtin_call (gimple_stmt_iterator *iter)
|
|
2193 {
|
|
2194 if (!ASAN_MEMINTRIN)
|
|
2195 return false;
|
|
2196
|
|
2197 bool iter_advanced_p = false;
|
|
2198 gcall *call = as_a <gcall *> (gsi_stmt (*iter));
|
|
2199
|
|
2200 gcc_checking_assert (gimple_call_builtin_p (call, BUILT_IN_NORMAL));
|
|
2201
|
|
2202 location_t loc = gimple_location (call);
|
|
2203
|
|
2204 asan_mem_ref src0, src1, dest;
|
|
2205 asan_mem_ref_init (&src0, NULL, 1);
|
|
2206 asan_mem_ref_init (&src1, NULL, 1);
|
|
2207 asan_mem_ref_init (&dest, NULL, 1);
|
|
2208
|
|
2209 tree src0_len = NULL_TREE, src1_len = NULL_TREE, dest_len = NULL_TREE;
|
|
2210 bool src0_is_store = false, src1_is_store = false, dest_is_store = false,
|
|
2211 dest_is_deref = false, intercepted_p = true;
|
|
2212
|
|
2213 if (get_mem_refs_of_builtin_call (call,
|
|
2214 &src0, &src0_len, &src0_is_store,
|
|
2215 &src1, &src1_len, &src1_is_store,
|
|
2216 &dest, &dest_len, &dest_is_store,
|
|
2217 &dest_is_deref, &intercepted_p, iter))
|
|
2218 {
|
|
2219 if (dest_is_deref)
|
|
2220 {
|
|
2221 instrument_derefs (iter, dest.start, loc, dest_is_store);
|
|
2222 gsi_next (iter);
|
|
2223 iter_advanced_p = true;
|
|
2224 }
|
|
2225 else if (!intercepted_p
|
|
2226 && (src0_len || src1_len || dest_len))
|
|
2227 {
|
|
2228 if (src0.start != NULL_TREE)
|
|
2229 instrument_mem_region_access (src0.start, src0_len,
|
|
2230 iter, loc, /*is_store=*/false);
|
|
2231 if (src1.start != NULL_TREE)
|
|
2232 instrument_mem_region_access (src1.start, src1_len,
|
|
2233 iter, loc, /*is_store=*/false);
|
|
2234 if (dest.start != NULL_TREE)
|
|
2235 instrument_mem_region_access (dest.start, dest_len,
|
|
2236 iter, loc, /*is_store=*/true);
|
|
2237
|
|
2238 *iter = gsi_for_stmt (call);
|
|
2239 gsi_next (iter);
|
|
2240 iter_advanced_p = true;
|
|
2241 }
|
|
2242 else
|
|
2243 {
|
|
2244 if (src0.start != NULL_TREE)
|
|
2245 maybe_update_mem_ref_hash_table (src0.start, src0_len);
|
|
2246 if (src1.start != NULL_TREE)
|
|
2247 maybe_update_mem_ref_hash_table (src1.start, src1_len);
|
|
2248 if (dest.start != NULL_TREE)
|
|
2249 maybe_update_mem_ref_hash_table (dest.start, dest_len);
|
|
2250 }
|
|
2251 }
|
|
2252 return iter_advanced_p;
|
|
2253 }
|
|
2254
|
|
2255 /* Instrument the assignment statement ITER if it is subject to
|
|
2256 instrumentation. Return TRUE iff instrumentation actually
|
|
2257 happened. In that case, the iterator ITER is advanced to the next
|
|
2258 logical expression following the one initially pointed to by ITER,
|
|
2259 and the relevant memory reference that which access has been
|
|
2260 instrumented is added to the memory references hash table. */
|
|
2261
|
|
2262 static bool
|
|
2263 maybe_instrument_assignment (gimple_stmt_iterator *iter)
|
|
2264 {
|
|
2265 gimple *s = gsi_stmt (*iter);
|
|
2266
|
|
2267 gcc_assert (gimple_assign_single_p (s));
|
|
2268
|
|
2269 tree ref_expr = NULL_TREE;
|
|
2270 bool is_store, is_instrumented = false;
|
|
2271
|
|
2272 if (gimple_store_p (s))
|
|
2273 {
|
|
2274 ref_expr = gimple_assign_lhs (s);
|
|
2275 is_store = true;
|
|
2276 instrument_derefs (iter, ref_expr,
|
|
2277 gimple_location (s),
|
|
2278 is_store);
|
|
2279 is_instrumented = true;
|
|
2280 }
|
|
2281
|
|
2282 if (gimple_assign_load_p (s))
|
|
2283 {
|
|
2284 ref_expr = gimple_assign_rhs1 (s);
|
|
2285 is_store = false;
|
|
2286 instrument_derefs (iter, ref_expr,
|
|
2287 gimple_location (s),
|
|
2288 is_store);
|
|
2289 is_instrumented = true;
|
|
2290 }
|
|
2291
|
|
2292 if (is_instrumented)
|
|
2293 gsi_next (iter);
|
|
2294
|
|
2295 return is_instrumented;
|
|
2296 }
|
|
2297
|
|
2298 /* Instrument the function call pointed to by the iterator ITER, if it
|
|
2299 is subject to instrumentation. At the moment, the only function
|
|
2300 calls that are instrumented are some built-in functions that access
|
|
2301 memory. Look at instrument_builtin_call to learn more.
|
|
2302
|
|
2303 Upon completion return TRUE iff *ITER was advanced to the statement
|
|
2304 following the one it was originally pointing to. */
|
|
2305
|
|
2306 static bool
|
|
2307 maybe_instrument_call (gimple_stmt_iterator *iter)
|
|
2308 {
|
|
2309 gimple *stmt = gsi_stmt (*iter);
|
|
2310 bool is_builtin = gimple_call_builtin_p (stmt, BUILT_IN_NORMAL);
|
|
2311
|
|
2312 if (is_builtin && instrument_builtin_call (iter))
|
|
2313 return true;
|
|
2314
|
|
2315 if (gimple_call_noreturn_p (stmt))
|
|
2316 {
|
|
2317 if (is_builtin)
|
|
2318 {
|
|
2319 tree callee = gimple_call_fndecl (stmt);
|
|
2320 switch (DECL_FUNCTION_CODE (callee))
|
|
2321 {
|
|
2322 case BUILT_IN_UNREACHABLE:
|
|
2323 case BUILT_IN_TRAP:
|
|
2324 /* Don't instrument these. */
|
|
2325 return false;
|
|
2326 default:
|
|
2327 break;
|
|
2328 }
|
|
2329 }
|
|
2330 tree decl = builtin_decl_implicit (BUILT_IN_ASAN_HANDLE_NO_RETURN);
|
|
2331 gimple *g = gimple_build_call (decl, 0);
|
|
2332 gimple_set_location (g, gimple_location (stmt));
|
|
2333 gsi_insert_before (iter, g, GSI_SAME_STMT);
|
|
2334 }
|
|
2335
|
|
2336 bool instrumented = false;
|
|
2337 if (gimple_store_p (stmt))
|
|
2338 {
|
|
2339 tree ref_expr = gimple_call_lhs (stmt);
|
|
2340 instrument_derefs (iter, ref_expr,
|
|
2341 gimple_location (stmt),
|
|
2342 /*is_store=*/true);
|
|
2343
|
|
2344 instrumented = true;
|
|
2345 }
|
|
2346
|
|
2347 /* Walk through gimple_call arguments and check them id needed. */
|
|
2348 unsigned args_num = gimple_call_num_args (stmt);
|
|
2349 for (unsigned i = 0; i < args_num; ++i)
|
|
2350 {
|
|
2351 tree arg = gimple_call_arg (stmt, i);
|
|
2352 /* If ARG is not a non-aggregate register variable, compiler in general
|
|
2353 creates temporary for it and pass it as argument to gimple call.
|
|
2354 But in some cases, e.g. when we pass by value a small structure that
|
|
2355 fits to register, compiler can avoid extra overhead by pulling out
|
|
2356 these temporaries. In this case, we should check the argument. */
|
|
2357 if (!is_gimple_reg (arg) && !is_gimple_min_invariant (arg))
|
|
2358 {
|
|
2359 instrument_derefs (iter, arg,
|
|
2360 gimple_location (stmt),
|
|
2361 /*is_store=*/false);
|
|
2362 instrumented = true;
|
|
2363 }
|
|
2364 }
|
|
2365 if (instrumented)
|
|
2366 gsi_next (iter);
|
|
2367 return instrumented;
|
|
2368 }
|
|
2369
|
|
2370 /* Walk each instruction of all basic block and instrument those that
|
|
2371 represent memory references: loads, stores, or function calls.
|
|
2372 In a given basic block, this function avoids instrumenting memory
|
|
2373 references that have already been instrumented. */
|
|
2374
|
|
2375 static void
|
|
2376 transform_statements (void)
|
|
2377 {
|
|
2378 basic_block bb, last_bb = NULL;
|
|
2379 gimple_stmt_iterator i;
|
|
2380 int saved_last_basic_block = last_basic_block_for_fn (cfun);
|
|
2381
|
|
2382 FOR_EACH_BB_FN (bb, cfun)
|
|
2383 {
|
|
2384 basic_block prev_bb = bb;
|
|
2385
|
|
2386 if (bb->index >= saved_last_basic_block) continue;
|
|
2387
|
|
2388 /* Flush the mem ref hash table, if current bb doesn't have
|
|
2389 exactly one predecessor, or if that predecessor (skipping
|
|
2390 over asan created basic blocks) isn't the last processed
|
|
2391 basic block. Thus we effectively flush on extended basic
|
|
2392 block boundaries. */
|
|
2393 while (single_pred_p (prev_bb))
|
|
2394 {
|
|
2395 prev_bb = single_pred (prev_bb);
|
|
2396 if (prev_bb->index < saved_last_basic_block)
|
|
2397 break;
|
|
2398 }
|
|
2399 if (prev_bb != last_bb)
|
|
2400 empty_mem_ref_hash_table ();
|
|
2401 last_bb = bb;
|
|
2402
|
|
2403 for (i = gsi_start_bb (bb); !gsi_end_p (i);)
|
|
2404 {
|
|
2405 gimple *s = gsi_stmt (i);
|
|
2406
|
|
2407 if (has_stmt_been_instrumented_p (s))
|
|
2408 gsi_next (&i);
|
|
2409 else if (gimple_assign_single_p (s)
|
|
2410 && !gimple_clobber_p (s)
|
|
2411 && maybe_instrument_assignment (&i))
|
|
2412 /* Nothing to do as maybe_instrument_assignment advanced
|
|
2413 the iterator I. */;
|
|
2414 else if (is_gimple_call (s) && maybe_instrument_call (&i))
|
|
2415 /* Nothing to do as maybe_instrument_call
|
|
2416 advanced the iterator I. */;
|
|
2417 else
|
|
2418 {
|
|
2419 /* No instrumentation happened.
|
|
2420
|
|
2421 If the current instruction is a function call that
|
|
2422 might free something, let's forget about the memory
|
|
2423 references that got instrumented. Otherwise we might
|
|
2424 miss some instrumentation opportunities. Do the same
|
|
2425 for a ASAN_MARK poisoning internal function. */
|
|
2426 if (is_gimple_call (s)
|
|
2427 && (!nonfreeing_call_p (s)
|
|
2428 || asan_mark_p (s, ASAN_MARK_POISON)))
|
|
2429 empty_mem_ref_hash_table ();
|
|
2430
|
|
2431 gsi_next (&i);
|
|
2432 }
|
|
2433 }
|
|
2434 }
|
|
2435 free_mem_ref_resources ();
|
|
2436 }
|
|
2437
|
|
2438 /* Build
|
|
2439 __asan_before_dynamic_init (module_name)
|
|
2440 or
|
|
2441 __asan_after_dynamic_init ()
|
|
2442 call. */
|
|
2443
|
|
2444 tree
|
|
2445 asan_dynamic_init_call (bool after_p)
|
|
2446 {
|
|
2447 if (shadow_ptr_types[0] == NULL_TREE)
|
|
2448 asan_init_shadow_ptr_types ();
|
|
2449
|
|
2450 tree fn = builtin_decl_implicit (after_p
|
|
2451 ? BUILT_IN_ASAN_AFTER_DYNAMIC_INIT
|
|
2452 : BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT);
|
|
2453 tree module_name_cst = NULL_TREE;
|
|
2454 if (!after_p)
|
|
2455 {
|
|
2456 pretty_printer module_name_pp;
|
|
2457 pp_string (&module_name_pp, main_input_filename);
|
|
2458
|
|
2459 module_name_cst = asan_pp_string (&module_name_pp);
|
|
2460 module_name_cst = fold_convert (const_ptr_type_node,
|
|
2461 module_name_cst);
|
|
2462 }
|
|
2463
|
|
2464 return build_call_expr (fn, after_p ? 0 : 1, module_name_cst);
|
|
2465 }
|
|
2466
|
|
2467 /* Build
|
|
2468 struct __asan_global
|
|
2469 {
|
|
2470 const void *__beg;
|
|
2471 uptr __size;
|
|
2472 uptr __size_with_redzone;
|
|
2473 const void *__name;
|
|
2474 const void *__module_name;
|
|
2475 uptr __has_dynamic_init;
|
|
2476 __asan_global_source_location *__location;
|
|
2477 char *__odr_indicator;
|
|
2478 } type. */
|
|
2479
|
|
2480 static tree
|
|
2481 asan_global_struct (void)
|
|
2482 {
|
|
2483 static const char *field_names[]
|
|
2484 = { "__beg", "__size", "__size_with_redzone",
|
|
2485 "__name", "__module_name", "__has_dynamic_init", "__location",
|
|
2486 "__odr_indicator" };
|
|
2487 tree fields[ARRAY_SIZE (field_names)], ret;
|
|
2488 unsigned i;
|
|
2489
|
|
2490 ret = make_node (RECORD_TYPE);
|
|
2491 for (i = 0; i < ARRAY_SIZE (field_names); i++)
|
|
2492 {
|
|
2493 fields[i]
|
|
2494 = build_decl (UNKNOWN_LOCATION, FIELD_DECL,
|
|
2495 get_identifier (field_names[i]),
|
|
2496 (i == 0 || i == 3) ? const_ptr_type_node
|
|
2497 : pointer_sized_int_node);
|
|
2498 DECL_CONTEXT (fields[i]) = ret;
|
|
2499 if (i)
|
|
2500 DECL_CHAIN (fields[i - 1]) = fields[i];
|
|
2501 }
|
|
2502 tree type_decl = build_decl (input_location, TYPE_DECL,
|
|
2503 get_identifier ("__asan_global"), ret);
|
|
2504 DECL_IGNORED_P (type_decl) = 1;
|
|
2505 DECL_ARTIFICIAL (type_decl) = 1;
|
|
2506 TYPE_FIELDS (ret) = fields[0];
|
|
2507 TYPE_NAME (ret) = type_decl;
|
|
2508 TYPE_STUB_DECL (ret) = type_decl;
|
|
2509 layout_type (ret);
|
|
2510 return ret;
|
|
2511 }
|
|
2512
|
|
2513 /* Create and return odr indicator symbol for DECL.
|
|
2514 TYPE is __asan_global struct type as returned by asan_global_struct. */
|
|
2515
|
|
2516 static tree
|
|
2517 create_odr_indicator (tree decl, tree type)
|
|
2518 {
|
|
2519 char *name;
|
|
2520 tree uptr = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (type)));
|
|
2521 tree decl_name
|
|
2522 = (HAS_DECL_ASSEMBLER_NAME_P (decl) ? DECL_ASSEMBLER_NAME (decl)
|
|
2523 : DECL_NAME (decl));
|
|
2524 /* DECL_NAME theoretically might be NULL. Bail out with 0 in this case. */
|
|
2525 if (decl_name == NULL_TREE)
|
|
2526 return build_int_cst (uptr, 0);
|
|
2527 const char *dname = IDENTIFIER_POINTER (decl_name);
|
|
2528 if (HAS_DECL_ASSEMBLER_NAME_P (decl))
|
|
2529 dname = targetm.strip_name_encoding (dname);
|
|
2530 size_t len = strlen (dname) + sizeof ("__odr_asan_");
|
|
2531 name = XALLOCAVEC (char, len);
|
|
2532 snprintf (name, len, "__odr_asan_%s", dname);
|
|
2533 #ifndef NO_DOT_IN_LABEL
|
|
2534 name[sizeof ("__odr_asan") - 1] = '.';
|
|
2535 #elif !defined(NO_DOLLAR_IN_LABEL)
|
|
2536 name[sizeof ("__odr_asan") - 1] = '$';
|
|
2537 #endif
|
|
2538 tree var = build_decl (UNKNOWN_LOCATION, VAR_DECL, get_identifier (name),
|
|
2539 char_type_node);
|
|
2540 TREE_ADDRESSABLE (var) = 1;
|
|
2541 TREE_READONLY (var) = 0;
|
|
2542 TREE_THIS_VOLATILE (var) = 1;
|
|
2543 DECL_GIMPLE_REG_P (var) = 0;
|
|
2544 DECL_ARTIFICIAL (var) = 1;
|
|
2545 DECL_IGNORED_P (var) = 1;
|
|
2546 TREE_STATIC (var) = 1;
|
|
2547 TREE_PUBLIC (var) = 1;
|
|
2548 DECL_VISIBILITY (var) = DECL_VISIBILITY (decl);
|
|
2549 DECL_VISIBILITY_SPECIFIED (var) = DECL_VISIBILITY_SPECIFIED (decl);
|
|
2550
|
|
2551 TREE_USED (var) = 1;
|
|
2552 tree ctor = build_constructor_va (TREE_TYPE (var), 1, NULL_TREE,
|
|
2553 build_int_cst (unsigned_type_node, 0));
|
|
2554 TREE_CONSTANT (ctor) = 1;
|
|
2555 TREE_STATIC (ctor) = 1;
|
|
2556 DECL_INITIAL (var) = ctor;
|
|
2557 DECL_ATTRIBUTES (var) = tree_cons (get_identifier ("asan odr indicator"),
|
|
2558 NULL, DECL_ATTRIBUTES (var));
|
|
2559 make_decl_rtl (var);
|
|
2560 varpool_node::finalize_decl (var);
|
|
2561 return fold_convert (uptr, build_fold_addr_expr (var));
|
|
2562 }
|
|
2563
|
|
2564 /* Return true if DECL, a global var, might be overridden and needs
|
|
2565 an additional odr indicator symbol. */
|
|
2566
|
|
2567 static bool
|
|
2568 asan_needs_odr_indicator_p (tree decl)
|
|
2569 {
|
|
2570 /* Don't emit ODR indicators for kernel because:
|
|
2571 a) Kernel is written in C thus doesn't need ODR indicators.
|
|
2572 b) Some kernel code may have assumptions about symbols containing specific
|
|
2573 patterns in their names. Since ODR indicators contain original names
|
|
2574 of symbols they are emitted for, these assumptions would be broken for
|
|
2575 ODR indicator symbols. */
|
|
2576 return (!(flag_sanitize & SANITIZE_KERNEL_ADDRESS)
|
|
2577 && !DECL_ARTIFICIAL (decl)
|
|
2578 && !DECL_WEAK (decl)
|
|
2579 && TREE_PUBLIC (decl));
|
|
2580 }
|
|
2581
|
|
2582 /* Append description of a single global DECL into vector V.
|
|
2583 TYPE is __asan_global struct type as returned by asan_global_struct. */
|
|
2584
|
|
2585 static void
|
|
2586 asan_add_global (tree decl, tree type, vec<constructor_elt, va_gc> *v)
|
|
2587 {
|
|
2588 tree init, uptr = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (type)));
|
|
2589 unsigned HOST_WIDE_INT size;
|
|
2590 tree str_cst, module_name_cst, refdecl = decl;
|
|
2591 vec<constructor_elt, va_gc> *vinner = NULL;
|
|
2592
|
|
2593 pretty_printer asan_pp, module_name_pp;
|
|
2594
|
|
2595 if (DECL_NAME (decl))
|
|
2596 pp_tree_identifier (&asan_pp, DECL_NAME (decl));
|
|
2597 else
|
|
2598 pp_string (&asan_pp, "<unknown>");
|
|
2599 str_cst = asan_pp_string (&asan_pp);
|
|
2600
|
|
2601 pp_string (&module_name_pp, main_input_filename);
|
|
2602 module_name_cst = asan_pp_string (&module_name_pp);
|
|
2603
|
|
2604 if (asan_needs_local_alias (decl))
|
|
2605 {
|
|
2606 char buf[20];
|
|
2607 ASM_GENERATE_INTERNAL_LABEL (buf, "LASAN", vec_safe_length (v) + 1);
|
|
2608 refdecl = build_decl (DECL_SOURCE_LOCATION (decl),
|
|
2609 VAR_DECL, get_identifier (buf), TREE_TYPE (decl));
|
|
2610 TREE_ADDRESSABLE (refdecl) = TREE_ADDRESSABLE (decl);
|
|
2611 TREE_READONLY (refdecl) = TREE_READONLY (decl);
|
|
2612 TREE_THIS_VOLATILE (refdecl) = TREE_THIS_VOLATILE (decl);
|
|
2613 DECL_GIMPLE_REG_P (refdecl) = DECL_GIMPLE_REG_P (decl);
|
|
2614 DECL_ARTIFICIAL (refdecl) = DECL_ARTIFICIAL (decl);
|
|
2615 DECL_IGNORED_P (refdecl) = DECL_IGNORED_P (decl);
|
|
2616 TREE_STATIC (refdecl) = 1;
|
|
2617 TREE_PUBLIC (refdecl) = 0;
|
|
2618 TREE_USED (refdecl) = 1;
|
|
2619 assemble_alias (refdecl, DECL_ASSEMBLER_NAME (decl));
|
|
2620 }
|
|
2621
|
|
2622 tree odr_indicator_ptr
|
|
2623 = (asan_needs_odr_indicator_p (decl) ? create_odr_indicator (decl, type)
|
|
2624 : build_int_cst (uptr, 0));
|
|
2625 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE,
|
|
2626 fold_convert (const_ptr_type_node,
|
|
2627 build_fold_addr_expr (refdecl)));
|
|
2628 size = tree_to_uhwi (DECL_SIZE_UNIT (decl));
|
|
2629 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, build_int_cst (uptr, size));
|
|
2630 size += asan_red_zone_size (size);
|
|
2631 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, build_int_cst (uptr, size));
|
|
2632 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE,
|
|
2633 fold_convert (const_ptr_type_node, str_cst));
|
|
2634 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE,
|
|
2635 fold_convert (const_ptr_type_node, module_name_cst));
|
|
2636 varpool_node *vnode = varpool_node::get (decl);
|
|
2637 int has_dynamic_init = 0;
|
|
2638 /* FIXME: Enable initialization order fiasco detection in LTO mode once
|
|
2639 proper fix for PR 79061 will be applied. */
|
|
2640 if (!in_lto_p)
|
|
2641 has_dynamic_init = vnode ? vnode->dynamically_initialized : 0;
|
|
2642 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE,
|
|
2643 build_int_cst (uptr, has_dynamic_init));
|
|
2644 tree locptr = NULL_TREE;
|
|
2645 location_t loc = DECL_SOURCE_LOCATION (decl);
|
|
2646 expanded_location xloc = expand_location (loc);
|
|
2647 if (xloc.file != NULL)
|
|
2648 {
|
|
2649 static int lasanloccnt = 0;
|
|
2650 char buf[25];
|
|
2651 ASM_GENERATE_INTERNAL_LABEL (buf, "LASANLOC", ++lasanloccnt);
|
|
2652 tree var = build_decl (UNKNOWN_LOCATION, VAR_DECL, get_identifier (buf),
|
|
2653 ubsan_get_source_location_type ());
|
|
2654 TREE_STATIC (var) = 1;
|
|
2655 TREE_PUBLIC (var) = 0;
|
|
2656 DECL_ARTIFICIAL (var) = 1;
|
|
2657 DECL_IGNORED_P (var) = 1;
|
|
2658 pretty_printer filename_pp;
|
|
2659 pp_string (&filename_pp, xloc.file);
|
|
2660 tree str = asan_pp_string (&filename_pp);
|
|
2661 tree ctor = build_constructor_va (TREE_TYPE (var), 3,
|
|
2662 NULL_TREE, str, NULL_TREE,
|
|
2663 build_int_cst (unsigned_type_node,
|
|
2664 xloc.line), NULL_TREE,
|
|
2665 build_int_cst (unsigned_type_node,
|
|
2666 xloc.column));
|
|
2667 TREE_CONSTANT (ctor) = 1;
|
|
2668 TREE_STATIC (ctor) = 1;
|
|
2669 DECL_INITIAL (var) = ctor;
|
|
2670 varpool_node::finalize_decl (var);
|
|
2671 locptr = fold_convert (uptr, build_fold_addr_expr (var));
|
|
2672 }
|
|
2673 else
|
|
2674 locptr = build_int_cst (uptr, 0);
|
|
2675 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, locptr);
|
|
2676 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, odr_indicator_ptr);
|
|
2677 init = build_constructor (type, vinner);
|
|
2678 CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, init);
|
|
2679 }
|
|
2680
|
|
2681 /* Initialize sanitizer.def builtins if the FE hasn't initialized them. */
|
|
2682 void
|
|
2683 initialize_sanitizer_builtins (void)
|
|
2684 {
|
|
2685 tree decl;
|
|
2686
|
|
2687 if (builtin_decl_implicit_p (BUILT_IN_ASAN_INIT))
|
|
2688 return;
|
|
2689
|
|
2690 tree BT_FN_VOID = build_function_type_list (void_type_node, NULL_TREE);
|
|
2691 tree BT_FN_VOID_PTR
|
|
2692 = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE);
|
|
2693 tree BT_FN_VOID_CONST_PTR
|
|
2694 = build_function_type_list (void_type_node, const_ptr_type_node, NULL_TREE);
|
|
2695 tree BT_FN_VOID_PTR_PTR
|
|
2696 = build_function_type_list (void_type_node, ptr_type_node,
|
|
2697 ptr_type_node, NULL_TREE);
|
|
2698 tree BT_FN_VOID_PTR_PTR_PTR
|
|
2699 = build_function_type_list (void_type_node, ptr_type_node,
|
|
2700 ptr_type_node, ptr_type_node, NULL_TREE);
|
|
2701 tree BT_FN_VOID_PTR_PTRMODE
|
|
2702 = build_function_type_list (void_type_node, ptr_type_node,
|
|
2703 pointer_sized_int_node, NULL_TREE);
|
|
2704 tree BT_FN_VOID_INT
|
|
2705 = build_function_type_list (void_type_node, integer_type_node, NULL_TREE);
|
|
2706 tree BT_FN_SIZE_CONST_PTR_INT
|
|
2707 = build_function_type_list (size_type_node, const_ptr_type_node,
|
|
2708 integer_type_node, NULL_TREE);
|
|
2709
|
|
2710 tree BT_FN_VOID_UINT8_UINT8
|
|
2711 = build_function_type_list (void_type_node, unsigned_char_type_node,
|
|
2712 unsigned_char_type_node, NULL_TREE);
|
|
2713 tree BT_FN_VOID_UINT16_UINT16
|
|
2714 = build_function_type_list (void_type_node, uint16_type_node,
|
|
2715 uint16_type_node, NULL_TREE);
|
|
2716 tree BT_FN_VOID_UINT32_UINT32
|
|
2717 = build_function_type_list (void_type_node, uint32_type_node,
|
|
2718 uint32_type_node, NULL_TREE);
|
|
2719 tree BT_FN_VOID_UINT64_UINT64
|
|
2720 = build_function_type_list (void_type_node, uint64_type_node,
|
|
2721 uint64_type_node, NULL_TREE);
|
|
2722 tree BT_FN_VOID_FLOAT_FLOAT
|
|
2723 = build_function_type_list (void_type_node, float_type_node,
|
|
2724 float_type_node, NULL_TREE);
|
|
2725 tree BT_FN_VOID_DOUBLE_DOUBLE
|
|
2726 = build_function_type_list (void_type_node, double_type_node,
|
|
2727 double_type_node, NULL_TREE);
|
|
2728 tree BT_FN_VOID_UINT64_PTR
|
|
2729 = build_function_type_list (void_type_node, uint64_type_node,
|
|
2730 ptr_type_node, NULL_TREE);
|
|
2731
|
|
2732 tree BT_FN_BOOL_VPTR_PTR_IX_INT_INT[5];
|
|
2733 tree BT_FN_IX_CONST_VPTR_INT[5];
|
|
2734 tree BT_FN_IX_VPTR_IX_INT[5];
|
|
2735 tree BT_FN_VOID_VPTR_IX_INT[5];
|
|
2736 tree vptr
|
|
2737 = build_pointer_type (build_qualified_type (void_type_node,
|
|
2738 TYPE_QUAL_VOLATILE));
|
|
2739 tree cvptr
|
|
2740 = build_pointer_type (build_qualified_type (void_type_node,
|
|
2741 TYPE_QUAL_VOLATILE
|
|
2742 |TYPE_QUAL_CONST));
|
|
2743 tree boolt
|
|
2744 = lang_hooks.types.type_for_size (BOOL_TYPE_SIZE, 1);
|
|
2745 int i;
|
|
2746 for (i = 0; i < 5; i++)
|
|
2747 {
|
|
2748 tree ix = build_nonstandard_integer_type (BITS_PER_UNIT * (1 << i), 1);
|
|
2749 BT_FN_BOOL_VPTR_PTR_IX_INT_INT[i]
|
|
2750 = build_function_type_list (boolt, vptr, ptr_type_node, ix,
|
|
2751 integer_type_node, integer_type_node,
|
|
2752 NULL_TREE);
|
|
2753 BT_FN_IX_CONST_VPTR_INT[i]
|
|
2754 = build_function_type_list (ix, cvptr, integer_type_node, NULL_TREE);
|
|
2755 BT_FN_IX_VPTR_IX_INT[i]
|
|
2756 = build_function_type_list (ix, vptr, ix, integer_type_node,
|
|
2757 NULL_TREE);
|
|
2758 BT_FN_VOID_VPTR_IX_INT[i]
|
|
2759 = build_function_type_list (void_type_node, vptr, ix,
|
|
2760 integer_type_node, NULL_TREE);
|
|
2761 }
|
|
2762 #define BT_FN_BOOL_VPTR_PTR_I1_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[0]
|
|
2763 #define BT_FN_I1_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[0]
|
|
2764 #define BT_FN_I1_VPTR_I1_INT BT_FN_IX_VPTR_IX_INT[0]
|
|
2765 #define BT_FN_VOID_VPTR_I1_INT BT_FN_VOID_VPTR_IX_INT[0]
|
|
2766 #define BT_FN_BOOL_VPTR_PTR_I2_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[1]
|
|
2767 #define BT_FN_I2_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[1]
|
|
2768 #define BT_FN_I2_VPTR_I2_INT BT_FN_IX_VPTR_IX_INT[1]
|
|
2769 #define BT_FN_VOID_VPTR_I2_INT BT_FN_VOID_VPTR_IX_INT[1]
|
|
2770 #define BT_FN_BOOL_VPTR_PTR_I4_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[2]
|
|
2771 #define BT_FN_I4_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[2]
|
|
2772 #define BT_FN_I4_VPTR_I4_INT BT_FN_IX_VPTR_IX_INT[2]
|
|
2773 #define BT_FN_VOID_VPTR_I4_INT BT_FN_VOID_VPTR_IX_INT[2]
|
|
2774 #define BT_FN_BOOL_VPTR_PTR_I8_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[3]
|
|
2775 #define BT_FN_I8_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[3]
|
|
2776 #define BT_FN_I8_VPTR_I8_INT BT_FN_IX_VPTR_IX_INT[3]
|
|
2777 #define BT_FN_VOID_VPTR_I8_INT BT_FN_VOID_VPTR_IX_INT[3]
|
|
2778 #define BT_FN_BOOL_VPTR_PTR_I16_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[4]
|
|
2779 #define BT_FN_I16_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[4]
|
|
2780 #define BT_FN_I16_VPTR_I16_INT BT_FN_IX_VPTR_IX_INT[4]
|
|
2781 #define BT_FN_VOID_VPTR_I16_INT BT_FN_VOID_VPTR_IX_INT[4]
|
|
2782 #undef ATTR_NOTHROW_LEAF_LIST
|
|
2783 #define ATTR_NOTHROW_LEAF_LIST ECF_NOTHROW | ECF_LEAF
|
|
2784 #undef ATTR_TMPURE_NOTHROW_LEAF_LIST
|
|
2785 #define ATTR_TMPURE_NOTHROW_LEAF_LIST ECF_TM_PURE | ATTR_NOTHROW_LEAF_LIST
|
|
2786 #undef ATTR_NORETURN_NOTHROW_LEAF_LIST
|
|
2787 #define ATTR_NORETURN_NOTHROW_LEAF_LIST ECF_NORETURN | ATTR_NOTHROW_LEAF_LIST
|
|
2788 #undef ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST
|
|
2789 #define ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST \
|
|
2790 ECF_CONST | ATTR_NORETURN_NOTHROW_LEAF_LIST
|
|
2791 #undef ATTR_TMPURE_NORETURN_NOTHROW_LEAF_LIST
|
|
2792 #define ATTR_TMPURE_NORETURN_NOTHROW_LEAF_LIST \
|
|
2793 ECF_TM_PURE | ATTR_NORETURN_NOTHROW_LEAF_LIST
|
|
2794 #undef ATTR_COLD_NOTHROW_LEAF_LIST
|
|
2795 #define ATTR_COLD_NOTHROW_LEAF_LIST \
|
|
2796 /* ECF_COLD missing */ ATTR_NOTHROW_LEAF_LIST
|
|
2797 #undef ATTR_COLD_NORETURN_NOTHROW_LEAF_LIST
|
|
2798 #define ATTR_COLD_NORETURN_NOTHROW_LEAF_LIST \
|
|
2799 /* ECF_COLD missing */ ATTR_NORETURN_NOTHROW_LEAF_LIST
|
|
2800 #undef ATTR_COLD_CONST_NORETURN_NOTHROW_LEAF_LIST
|
|
2801 #define ATTR_COLD_CONST_NORETURN_NOTHROW_LEAF_LIST \
|
|
2802 /* ECF_COLD missing */ ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST
|
|
2803 #undef ATTR_PURE_NOTHROW_LEAF_LIST
|
|
2804 #define ATTR_PURE_NOTHROW_LEAF_LIST ECF_PURE | ATTR_NOTHROW_LEAF_LIST
|
|
2805 #undef DEF_BUILTIN_STUB
|
|
2806 #define DEF_BUILTIN_STUB(ENUM, NAME)
|
|
2807 #undef DEF_SANITIZER_BUILTIN
|
|
2808 #define DEF_SANITIZER_BUILTIN(ENUM, NAME, TYPE, ATTRS) \
|
|
2809 do { \
|
|
2810 decl = add_builtin_function ("__builtin_" NAME, TYPE, ENUM, \
|
|
2811 BUILT_IN_NORMAL, NAME, NULL_TREE); \
|
|
2812 set_call_expr_flags (decl, ATTRS); \
|
|
2813 set_builtin_decl (ENUM, decl, true); \
|
|
2814 } while (0);
|
|
2815
|
|
2816 #include "sanitizer.def"
|
|
2817
|
|
2818 /* -fsanitize=object-size uses __builtin_object_size, but that might
|
|
2819 not be available for e.g. Fortran at this point. We use
|
|
2820 DEF_SANITIZER_BUILTIN here only as a convenience macro. */
|
|
2821 if ((flag_sanitize & SANITIZE_OBJECT_SIZE)
|
|
2822 && !builtin_decl_implicit_p (BUILT_IN_OBJECT_SIZE))
|
|
2823 DEF_SANITIZER_BUILTIN (BUILT_IN_OBJECT_SIZE, "object_size",
|
|
2824 BT_FN_SIZE_CONST_PTR_INT,
|
|
2825 ATTR_PURE_NOTHROW_LEAF_LIST)
|
|
2826
|
|
2827 #undef DEF_SANITIZER_BUILTIN
|
|
2828 #undef DEF_BUILTIN_STUB
|
|
2829 }
|
|
2830
|
|
2831 /* Called via htab_traverse. Count number of emitted
|
|
2832 STRING_CSTs in the constant hash table. */
|
|
2833
|
|
2834 int
|
|
2835 count_string_csts (constant_descriptor_tree **slot,
|
|
2836 unsigned HOST_WIDE_INT *data)
|
|
2837 {
|
|
2838 struct constant_descriptor_tree *desc = *slot;
|
|
2839 if (TREE_CODE (desc->value) == STRING_CST
|
|
2840 && TREE_ASM_WRITTEN (desc->value)
|
|
2841 && asan_protect_global (desc->value))
|
|
2842 ++*data;
|
|
2843 return 1;
|
|
2844 }
|
|
2845
|
|
2846 /* Helper structure to pass two parameters to
|
|
2847 add_string_csts. */
|
|
2848
|
|
2849 struct asan_add_string_csts_data
|
|
2850 {
|
|
2851 tree type;
|
|
2852 vec<constructor_elt, va_gc> *v;
|
|
2853 };
|
|
2854
|
|
2855 /* Called via hash_table::traverse. Call asan_add_global
|
|
2856 on emitted STRING_CSTs from the constant hash table. */
|
|
2857
|
|
2858 int
|
|
2859 add_string_csts (constant_descriptor_tree **slot,
|
|
2860 asan_add_string_csts_data *aascd)
|
|
2861 {
|
|
2862 struct constant_descriptor_tree *desc = *slot;
|
|
2863 if (TREE_CODE (desc->value) == STRING_CST
|
|
2864 && TREE_ASM_WRITTEN (desc->value)
|
|
2865 && asan_protect_global (desc->value))
|
|
2866 {
|
|
2867 asan_add_global (SYMBOL_REF_DECL (XEXP (desc->rtl, 0)),
|
|
2868 aascd->type, aascd->v);
|
|
2869 }
|
|
2870 return 1;
|
|
2871 }
|
|
2872
|
|
2873 /* Needs to be GTY(()), because cgraph_build_static_cdtor may
|
|
2874 invoke ggc_collect. */
|
|
2875 static GTY(()) tree asan_ctor_statements;
|
|
2876
|
|
2877 /* Module-level instrumentation.
|
|
2878 - Insert __asan_init_vN() into the list of CTORs.
|
|
2879 - TODO: insert redzones around globals.
|
|
2880 */
|
|
2881
|
|
2882 void
|
|
2883 asan_finish_file (void)
|
|
2884 {
|
|
2885 varpool_node *vnode;
|
|
2886 unsigned HOST_WIDE_INT gcount = 0;
|
|
2887
|
|
2888 if (shadow_ptr_types[0] == NULL_TREE)
|
|
2889 asan_init_shadow_ptr_types ();
|
|
2890 /* Avoid instrumenting code in the asan ctors/dtors.
|
|
2891 We don't need to insert padding after the description strings,
|
|
2892 nor after .LASAN* array. */
|
|
2893 flag_sanitize &= ~SANITIZE_ADDRESS;
|
|
2894
|
|
2895 /* For user-space we want asan constructors to run first.
|
|
2896 Linux kernel does not support priorities other than default, and the only
|
|
2897 other user of constructors is coverage. So we run with the default
|
|
2898 priority. */
|
|
2899 int priority = flag_sanitize & SANITIZE_USER_ADDRESS
|
|
2900 ? MAX_RESERVED_INIT_PRIORITY - 1 : DEFAULT_INIT_PRIORITY;
|
|
2901
|
|
2902 if (flag_sanitize & SANITIZE_USER_ADDRESS)
|
|
2903 {
|
|
2904 tree fn = builtin_decl_implicit (BUILT_IN_ASAN_INIT);
|
|
2905 append_to_statement_list (build_call_expr (fn, 0), &asan_ctor_statements);
|
|
2906 fn = builtin_decl_implicit (BUILT_IN_ASAN_VERSION_MISMATCH_CHECK);
|
|
2907 append_to_statement_list (build_call_expr (fn, 0), &asan_ctor_statements);
|
|
2908 }
|
|
2909 FOR_EACH_DEFINED_VARIABLE (vnode)
|
|
2910 if (TREE_ASM_WRITTEN (vnode->decl)
|
|
2911 && asan_protect_global (vnode->decl))
|
|
2912 ++gcount;
|
|
2913 hash_table<tree_descriptor_hasher> *const_desc_htab = constant_pool_htab ();
|
|
2914 const_desc_htab->traverse<unsigned HOST_WIDE_INT *, count_string_csts>
|
|
2915 (&gcount);
|
|
2916 if (gcount)
|
|
2917 {
|
|
2918 tree type = asan_global_struct (), var, ctor;
|
|
2919 tree dtor_statements = NULL_TREE;
|
|
2920 vec<constructor_elt, va_gc> *v;
|
|
2921 char buf[20];
|
|
2922
|
|
2923 type = build_array_type_nelts (type, gcount);
|
|
2924 ASM_GENERATE_INTERNAL_LABEL (buf, "LASAN", 0);
|
|
2925 var = build_decl (UNKNOWN_LOCATION, VAR_DECL, get_identifier (buf),
|
|
2926 type);
|
|
2927 TREE_STATIC (var) = 1;
|
|
2928 TREE_PUBLIC (var) = 0;
|
|
2929 DECL_ARTIFICIAL (var) = 1;
|
|
2930 DECL_IGNORED_P (var) = 1;
|
|
2931 vec_alloc (v, gcount);
|
|
2932 FOR_EACH_DEFINED_VARIABLE (vnode)
|
|
2933 if (TREE_ASM_WRITTEN (vnode->decl)
|
|
2934 && asan_protect_global (vnode->decl))
|
|
2935 asan_add_global (vnode->decl, TREE_TYPE (type), v);
|
|
2936 struct asan_add_string_csts_data aascd;
|
|
2937 aascd.type = TREE_TYPE (type);
|
|
2938 aascd.v = v;
|
|
2939 const_desc_htab->traverse<asan_add_string_csts_data *, add_string_csts>
|
|
2940 (&aascd);
|
|
2941 ctor = build_constructor (type, v);
|
|
2942 TREE_CONSTANT (ctor) = 1;
|
|
2943 TREE_STATIC (ctor) = 1;
|
|
2944 DECL_INITIAL (var) = ctor;
|
|
2945 varpool_node::finalize_decl (var);
|
|
2946
|
|
2947 tree fn = builtin_decl_implicit (BUILT_IN_ASAN_REGISTER_GLOBALS);
|
|
2948 tree gcount_tree = build_int_cst (pointer_sized_int_node, gcount);
|
|
2949 append_to_statement_list (build_call_expr (fn, 2,
|
|
2950 build_fold_addr_expr (var),
|
|
2951 gcount_tree),
|
|
2952 &asan_ctor_statements);
|
|
2953
|
|
2954 fn = builtin_decl_implicit (BUILT_IN_ASAN_UNREGISTER_GLOBALS);
|
|
2955 append_to_statement_list (build_call_expr (fn, 2,
|
|
2956 build_fold_addr_expr (var),
|
|
2957 gcount_tree),
|
|
2958 &dtor_statements);
|
|
2959 cgraph_build_static_cdtor ('D', dtor_statements, priority);
|
|
2960 }
|
|
2961 if (asan_ctor_statements)
|
|
2962 cgraph_build_static_cdtor ('I', asan_ctor_statements, priority);
|
|
2963 flag_sanitize |= SANITIZE_ADDRESS;
|
|
2964 }
|
|
2965
|
|
2966 /* Poison or unpoison (depending on IS_CLOBBER variable) shadow memory based
|
|
2967 on SHADOW address. Newly added statements will be added to ITER with
|
|
2968 given location LOC. We mark SIZE bytes in shadow memory, where
|
|
2969 LAST_CHUNK_SIZE is greater than zero in situation where we are at the
|
|
2970 end of a variable. */
|
|
2971
|
|
2972 static void
|
|
2973 asan_store_shadow_bytes (gimple_stmt_iterator *iter, location_t loc,
|
|
2974 tree shadow,
|
|
2975 unsigned HOST_WIDE_INT base_addr_offset,
|
|
2976 bool is_clobber, unsigned size,
|
|
2977 unsigned last_chunk_size)
|
|
2978 {
|
|
2979 tree shadow_ptr_type;
|
|
2980
|
|
2981 switch (size)
|
|
2982 {
|
|
2983 case 1:
|
|
2984 shadow_ptr_type = shadow_ptr_types[0];
|
|
2985 break;
|
|
2986 case 2:
|
|
2987 shadow_ptr_type = shadow_ptr_types[1];
|
|
2988 break;
|
|
2989 case 4:
|
|
2990 shadow_ptr_type = shadow_ptr_types[2];
|
|
2991 break;
|
|
2992 default:
|
|
2993 gcc_unreachable ();
|
|
2994 }
|
|
2995
|
|
2996 unsigned char c = (char) is_clobber ? ASAN_STACK_MAGIC_USE_AFTER_SCOPE : 0;
|
|
2997 unsigned HOST_WIDE_INT val = 0;
|
|
2998 unsigned last_pos = size;
|
|
2999 if (last_chunk_size && !is_clobber)
|
|
3000 last_pos = BYTES_BIG_ENDIAN ? 0 : size - 1;
|
|
3001 for (unsigned i = 0; i < size; ++i)
|
|
3002 {
|
|
3003 unsigned char shadow_c = c;
|
|
3004 if (i == last_pos)
|
|
3005 shadow_c = last_chunk_size;
|
|
3006 val |= (unsigned HOST_WIDE_INT) shadow_c << (BITS_PER_UNIT * i);
|
|
3007 }
|
|
3008
|
|
3009 /* Handle last chunk in unpoisoning. */
|
|
3010 tree magic = build_int_cst (TREE_TYPE (shadow_ptr_type), val);
|
|
3011
|
|
3012 tree dest = build2 (MEM_REF, TREE_TYPE (shadow_ptr_type), shadow,
|
|
3013 build_int_cst (shadow_ptr_type, base_addr_offset));
|
|
3014
|
|
3015 gimple *g = gimple_build_assign (dest, magic);
|
|
3016 gimple_set_location (g, loc);
|
|
3017 gsi_insert_after (iter, g, GSI_NEW_STMT);
|
|
3018 }
|
|
3019
|
|
3020 /* Expand the ASAN_MARK builtins. */
|
|
3021
|
|
3022 bool
|
|
3023 asan_expand_mark_ifn (gimple_stmt_iterator *iter)
|
|
3024 {
|
|
3025 gimple *g = gsi_stmt (*iter);
|
|
3026 location_t loc = gimple_location (g);
|
|
3027 HOST_WIDE_INT flag = tree_to_shwi (gimple_call_arg (g, 0));
|
|
3028 bool is_poison = ((asan_mark_flags)flag) == ASAN_MARK_POISON;
|
|
3029
|
|
3030 tree base = gimple_call_arg (g, 1);
|
|
3031 gcc_checking_assert (TREE_CODE (base) == ADDR_EXPR);
|
|
3032 tree decl = TREE_OPERAND (base, 0);
|
|
3033
|
|
3034 /* For a nested function, we can have: ASAN_MARK (2, &FRAME.2.fp_input, 4) */
|
|
3035 if (TREE_CODE (decl) == COMPONENT_REF
|
|
3036 && DECL_NONLOCAL_FRAME (TREE_OPERAND (decl, 0)))
|
|
3037 decl = TREE_OPERAND (decl, 0);
|
|
3038
|
|
3039 gcc_checking_assert (TREE_CODE (decl) == VAR_DECL);
|
|
3040
|
|
3041 if (is_poison)
|
|
3042 {
|
|
3043 if (asan_handled_variables == NULL)
|
|
3044 asan_handled_variables = new hash_set<tree> (16);
|
|
3045 asan_handled_variables->add (decl);
|
|
3046 }
|
|
3047 tree len = gimple_call_arg (g, 2);
|
|
3048
|
|
3049 gcc_assert (tree_fits_shwi_p (len));
|
|
3050 unsigned HOST_WIDE_INT size_in_bytes = tree_to_shwi (len);
|
|
3051 gcc_assert (size_in_bytes);
|
|
3052
|
|
3053 g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
|
|
3054 NOP_EXPR, base);
|
|
3055 gimple_set_location (g, loc);
|
|
3056 gsi_replace (iter, g, false);
|
|
3057 tree base_addr = gimple_assign_lhs (g);
|
|
3058
|
|
3059 /* Generate direct emission if size_in_bytes is small. */
|
|
3060 if (size_in_bytes <= ASAN_PARAM_USE_AFTER_SCOPE_DIRECT_EMISSION_THRESHOLD)
|
|
3061 {
|
|
3062 unsigned HOST_WIDE_INT shadow_size = shadow_mem_size (size_in_bytes);
|
|
3063
|
|
3064 tree shadow = build_shadow_mem_access (iter, loc, base_addr,
|
|
3065 shadow_ptr_types[0], true);
|
|
3066
|
|
3067 for (unsigned HOST_WIDE_INT offset = 0; offset < shadow_size;)
|
|
3068 {
|
|
3069 unsigned size = 1;
|
|
3070 if (shadow_size - offset >= 4)
|
|
3071 size = 4;
|
|
3072 else if (shadow_size - offset >= 2)
|
|
3073 size = 2;
|
|
3074
|
|
3075 unsigned HOST_WIDE_INT last_chunk_size = 0;
|
|
3076 unsigned HOST_WIDE_INT s = (offset + size) * ASAN_SHADOW_GRANULARITY;
|
|
3077 if (s > size_in_bytes)
|
|
3078 last_chunk_size = ASAN_SHADOW_GRANULARITY - (s - size_in_bytes);
|
|
3079
|
|
3080 asan_store_shadow_bytes (iter, loc, shadow, offset, is_poison,
|
|
3081 size, last_chunk_size);
|
|
3082 offset += size;
|
|
3083 }
|
|
3084 }
|
|
3085 else
|
|
3086 {
|
|
3087 g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
|
|
3088 NOP_EXPR, len);
|
|
3089 gimple_set_location (g, loc);
|
|
3090 gsi_insert_before (iter, g, GSI_SAME_STMT);
|
|
3091 tree sz_arg = gimple_assign_lhs (g);
|
|
3092
|
|
3093 tree fun
|
|
3094 = builtin_decl_implicit (is_poison ? BUILT_IN_ASAN_POISON_STACK_MEMORY
|
|
3095 : BUILT_IN_ASAN_UNPOISON_STACK_MEMORY);
|
|
3096 g = gimple_build_call (fun, 2, base_addr, sz_arg);
|
|
3097 gimple_set_location (g, loc);
|
|
3098 gsi_insert_after (iter, g, GSI_NEW_STMT);
|
|
3099 }
|
|
3100
|
|
3101 return false;
|
|
3102 }
|
|
3103
|
|
3104 /* Expand the ASAN_{LOAD,STORE} builtins. */
|
|
3105
|
|
3106 bool
|
|
3107 asan_expand_check_ifn (gimple_stmt_iterator *iter, bool use_calls)
|
|
3108 {
|
|
3109 gimple *g = gsi_stmt (*iter);
|
|
3110 location_t loc = gimple_location (g);
|
|
3111 bool recover_p;
|
|
3112 if (flag_sanitize & SANITIZE_USER_ADDRESS)
|
|
3113 recover_p = (flag_sanitize_recover & SANITIZE_USER_ADDRESS) != 0;
|
|
3114 else
|
|
3115 recover_p = (flag_sanitize_recover & SANITIZE_KERNEL_ADDRESS) != 0;
|
|
3116
|
|
3117 HOST_WIDE_INT flags = tree_to_shwi (gimple_call_arg (g, 0));
|
|
3118 gcc_assert (flags < ASAN_CHECK_LAST);
|
|
3119 bool is_scalar_access = (flags & ASAN_CHECK_SCALAR_ACCESS) != 0;
|
|
3120 bool is_store = (flags & ASAN_CHECK_STORE) != 0;
|
|
3121 bool is_non_zero_len = (flags & ASAN_CHECK_NON_ZERO_LEN) != 0;
|
|
3122
|
|
3123 tree base = gimple_call_arg (g, 1);
|
|
3124 tree len = gimple_call_arg (g, 2);
|
|
3125 HOST_WIDE_INT align = tree_to_shwi (gimple_call_arg (g, 3));
|
|
3126
|
|
3127 HOST_WIDE_INT size_in_bytes
|
|
3128 = is_scalar_access && tree_fits_shwi_p (len) ? tree_to_shwi (len) : -1;
|
|
3129
|
|
3130 if (use_calls)
|
|
3131 {
|
|
3132 /* Instrument using callbacks. */
|
|
3133 gimple *g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
|
|
3134 NOP_EXPR, base);
|
|
3135 gimple_set_location (g, loc);
|
|
3136 gsi_insert_before (iter, g, GSI_SAME_STMT);
|
|
3137 tree base_addr = gimple_assign_lhs (g);
|
|
3138
|
|
3139 int nargs;
|
|
3140 tree fun = check_func (is_store, recover_p, size_in_bytes, &nargs);
|
|
3141 if (nargs == 1)
|
|
3142 g = gimple_build_call (fun, 1, base_addr);
|
|
3143 else
|
|
3144 {
|
|
3145 gcc_assert (nargs == 2);
|
|
3146 g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
|
|
3147 NOP_EXPR, len);
|
|
3148 gimple_set_location (g, loc);
|
|
3149 gsi_insert_before (iter, g, GSI_SAME_STMT);
|
|
3150 tree sz_arg = gimple_assign_lhs (g);
|
|
3151 g = gimple_build_call (fun, nargs, base_addr, sz_arg);
|
|
3152 }
|
|
3153 gimple_set_location (g, loc);
|
|
3154 gsi_replace (iter, g, false);
|
|
3155 return false;
|
|
3156 }
|
|
3157
|
|
3158 HOST_WIDE_INT real_size_in_bytes = size_in_bytes == -1 ? 1 : size_in_bytes;
|
|
3159
|
|
3160 tree shadow_ptr_type = shadow_ptr_types[real_size_in_bytes == 16 ? 1 : 0];
|
|
3161 tree shadow_type = TREE_TYPE (shadow_ptr_type);
|
|
3162
|
|
3163 gimple_stmt_iterator gsi = *iter;
|
|
3164
|
|
3165 if (!is_non_zero_len)
|
|
3166 {
|
|
3167 /* So, the length of the memory area to asan-protect is
|
|
3168 non-constant. Let's guard the generated instrumentation code
|
|
3169 like:
|
|
3170
|
|
3171 if (len != 0)
|
|
3172 {
|
|
3173 //asan instrumentation code goes here.
|
|
3174 }
|
|
3175 // falltrough instructions, starting with *ITER. */
|
|
3176
|
|
3177 g = gimple_build_cond (NE_EXPR,
|
|
3178 len,
|
|
3179 build_int_cst (TREE_TYPE (len), 0),
|
|
3180 NULL_TREE, NULL_TREE);
|
|
3181 gimple_set_location (g, loc);
|
|
3182
|
|
3183 basic_block then_bb, fallthrough_bb;
|
|
3184 insert_if_then_before_iter (as_a <gcond *> (g), iter,
|
|
3185 /*then_more_likely_p=*/true,
|
|
3186 &then_bb, &fallthrough_bb);
|
|
3187 /* Note that fallthrough_bb starts with the statement that was
|
|
3188 pointed to by ITER. */
|
|
3189
|
|
3190 /* The 'then block' of the 'if (len != 0) condition is where
|
|
3191 we'll generate the asan instrumentation code now. */
|
|
3192 gsi = gsi_last_bb (then_bb);
|
|
3193 }
|
|
3194
|
|
3195 /* Get an iterator on the point where we can add the condition
|
|
3196 statement for the instrumentation. */
|
|
3197 basic_block then_bb, else_bb;
|
|
3198 gsi = create_cond_insert_point (&gsi, /*before_p*/false,
|
|
3199 /*then_more_likely_p=*/false,
|
|
3200 /*create_then_fallthru_edge*/recover_p,
|
|
3201 &then_bb,
|
|
3202 &else_bb);
|
|
3203
|
|
3204 g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
|
|
3205 NOP_EXPR, base);
|
|
3206 gimple_set_location (g, loc);
|
|
3207 gsi_insert_before (&gsi, g, GSI_NEW_STMT);
|
|
3208 tree base_addr = gimple_assign_lhs (g);
|
|
3209
|
|
3210 tree t = NULL_TREE;
|
|
3211 if (real_size_in_bytes >= 8)
|
|
3212 {
|
|
3213 tree shadow = build_shadow_mem_access (&gsi, loc, base_addr,
|
|
3214 shadow_ptr_type);
|
|
3215 t = shadow;
|
|
3216 }
|
|
3217 else
|
|
3218 {
|
|
3219 /* Slow path for 1, 2 and 4 byte accesses. */
|
|
3220 /* Test (shadow != 0)
|
|
3221 & ((base_addr & 7) + (real_size_in_bytes - 1)) >= shadow). */
|
|
3222 tree shadow = build_shadow_mem_access (&gsi, loc, base_addr,
|
|
3223 shadow_ptr_type);
|
|
3224 gimple *shadow_test = build_assign (NE_EXPR, shadow, 0);
|
|
3225 gimple_seq seq = NULL;
|
|
3226 gimple_seq_add_stmt (&seq, shadow_test);
|
|
3227 /* Aligned (>= 8 bytes) can test just
|
|
3228 (real_size_in_bytes - 1 >= shadow), as base_addr & 7 is known
|
|
3229 to be 0. */
|
|
3230 if (align < 8)
|
|
3231 {
|
|
3232 gimple_seq_add_stmt (&seq, build_assign (BIT_AND_EXPR,
|
|
3233 base_addr, 7));
|
|
3234 gimple_seq_add_stmt (&seq,
|
|
3235 build_type_cast (shadow_type,
|
|
3236 gimple_seq_last (seq)));
|
|
3237 if (real_size_in_bytes > 1)
|
|
3238 gimple_seq_add_stmt (&seq,
|
|
3239 build_assign (PLUS_EXPR,
|
|
3240 gimple_seq_last (seq),
|
|
3241 real_size_in_bytes - 1));
|
|
3242 t = gimple_assign_lhs (gimple_seq_last_stmt (seq));
|
|
3243 }
|
|
3244 else
|
|
3245 t = build_int_cst (shadow_type, real_size_in_bytes - 1);
|
|
3246 gimple_seq_add_stmt (&seq, build_assign (GE_EXPR, t, shadow));
|
|
3247 gimple_seq_add_stmt (&seq, build_assign (BIT_AND_EXPR, shadow_test,
|
|
3248 gimple_seq_last (seq)));
|
|
3249 t = gimple_assign_lhs (gimple_seq_last (seq));
|
|
3250 gimple_seq_set_location (seq, loc);
|
|
3251 gsi_insert_seq_after (&gsi, seq, GSI_CONTINUE_LINKING);
|
|
3252
|
|
3253 /* For non-constant, misaligned or otherwise weird access sizes,
|
|
3254 check first and last byte. */
|
|
3255 if (size_in_bytes == -1)
|
|
3256 {
|
|
3257 g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
|
|
3258 MINUS_EXPR, len,
|
|
3259 build_int_cst (pointer_sized_int_node, 1));
|
|
3260 gimple_set_location (g, loc);
|
|
3261 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
|
|
3262 tree last = gimple_assign_lhs (g);
|
|
3263 g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
|
|
3264 PLUS_EXPR, base_addr, last);
|
|
3265 gimple_set_location (g, loc);
|
|
3266 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
|
|
3267 tree base_end_addr = gimple_assign_lhs (g);
|
|
3268
|
|
3269 tree shadow = build_shadow_mem_access (&gsi, loc, base_end_addr,
|
|
3270 shadow_ptr_type);
|
|
3271 gimple *shadow_test = build_assign (NE_EXPR, shadow, 0);
|
|
3272 gimple_seq seq = NULL;
|
|
3273 gimple_seq_add_stmt (&seq, shadow_test);
|
|
3274 gimple_seq_add_stmt (&seq, build_assign (BIT_AND_EXPR,
|
|
3275 base_end_addr, 7));
|
|
3276 gimple_seq_add_stmt (&seq, build_type_cast (shadow_type,
|
|
3277 gimple_seq_last (seq)));
|
|
3278 gimple_seq_add_stmt (&seq, build_assign (GE_EXPR,
|
|
3279 gimple_seq_last (seq),
|
|
3280 shadow));
|
|
3281 gimple_seq_add_stmt (&seq, build_assign (BIT_AND_EXPR, shadow_test,
|
|
3282 gimple_seq_last (seq)));
|
|
3283 gimple_seq_add_stmt (&seq, build_assign (BIT_IOR_EXPR, t,
|
|
3284 gimple_seq_last (seq)));
|
|
3285 t = gimple_assign_lhs (gimple_seq_last (seq));
|
|
3286 gimple_seq_set_location (seq, loc);
|
|
3287 gsi_insert_seq_after (&gsi, seq, GSI_CONTINUE_LINKING);
|
|
3288 }
|
|
3289 }
|
|
3290
|
|
3291 g = gimple_build_cond (NE_EXPR, t, build_int_cst (TREE_TYPE (t), 0),
|
|
3292 NULL_TREE, NULL_TREE);
|
|
3293 gimple_set_location (g, loc);
|
|
3294 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
|
|
3295
|
|
3296 /* Generate call to the run-time library (e.g. __asan_report_load8). */
|
|
3297 gsi = gsi_start_bb (then_bb);
|
|
3298 int nargs;
|
|
3299 tree fun = report_error_func (is_store, recover_p, size_in_bytes, &nargs);
|
|
3300 g = gimple_build_call (fun, nargs, base_addr, len);
|
|
3301 gimple_set_location (g, loc);
|
|
3302 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
|
|
3303
|
|
3304 gsi_remove (iter, true);
|
|
3305 *iter = gsi_start_bb (else_bb);
|
|
3306
|
|
3307 return true;
|
|
3308 }
|
|
3309
|
|
3310 /* Create ASAN shadow variable for a VAR_DECL which has been rewritten
|
|
3311 into SSA. Already seen VAR_DECLs are stored in SHADOW_VARS_MAPPING. */
|
|
3312
|
|
3313 static tree
|
|
3314 create_asan_shadow_var (tree var_decl,
|
|
3315 hash_map<tree, tree> &shadow_vars_mapping)
|
|
3316 {
|
|
3317 tree *slot = shadow_vars_mapping.get (var_decl);
|
|
3318 if (slot == NULL)
|
|
3319 {
|
|
3320 tree shadow_var = copy_node (var_decl);
|
|
3321
|
|
3322 copy_body_data id;
|
|
3323 memset (&id, 0, sizeof (copy_body_data));
|
|
3324 id.src_fn = id.dst_fn = current_function_decl;
|
|
3325 copy_decl_for_dup_finish (&id, var_decl, shadow_var);
|
|
3326
|
|
3327 DECL_ARTIFICIAL (shadow_var) = 1;
|
|
3328 DECL_IGNORED_P (shadow_var) = 1;
|
|
3329 DECL_SEEN_IN_BIND_EXPR_P (shadow_var) = 0;
|
|
3330 gimple_add_tmp_var (shadow_var);
|
|
3331
|
|
3332 shadow_vars_mapping.put (var_decl, shadow_var);
|
|
3333 return shadow_var;
|
|
3334 }
|
|
3335 else
|
|
3336 return *slot;
|
|
3337 }
|
|
3338
|
|
3339 /* Expand ASAN_POISON ifn. */
|
|
3340
|
|
3341 bool
|
|
3342 asan_expand_poison_ifn (gimple_stmt_iterator *iter,
|
|
3343 bool *need_commit_edge_insert,
|
|
3344 hash_map<tree, tree> &shadow_vars_mapping)
|
|
3345 {
|
|
3346 gimple *g = gsi_stmt (*iter);
|
|
3347 tree poisoned_var = gimple_call_lhs (g);
|
|
3348 if (!poisoned_var || has_zero_uses (poisoned_var))
|
|
3349 {
|
|
3350 gsi_remove (iter, true);
|
|
3351 return true;
|
|
3352 }
|
|
3353
|
|
3354 if (SSA_NAME_VAR (poisoned_var) == NULL_TREE)
|
|
3355 SET_SSA_NAME_VAR_OR_IDENTIFIER (poisoned_var,
|
|
3356 create_tmp_var (TREE_TYPE (poisoned_var)));
|
|
3357
|
|
3358 tree shadow_var = create_asan_shadow_var (SSA_NAME_VAR (poisoned_var),
|
|
3359 shadow_vars_mapping);
|
|
3360
|
|
3361 bool recover_p;
|
|
3362 if (flag_sanitize & SANITIZE_USER_ADDRESS)
|
|
3363 recover_p = (flag_sanitize_recover & SANITIZE_USER_ADDRESS) != 0;
|
|
3364 else
|
|
3365 recover_p = (flag_sanitize_recover & SANITIZE_KERNEL_ADDRESS) != 0;
|
|
3366 tree size = DECL_SIZE_UNIT (shadow_var);
|
|
3367 gimple *poison_call
|
|
3368 = gimple_build_call_internal (IFN_ASAN_MARK, 3,
|
|
3369 build_int_cst (integer_type_node,
|
|
3370 ASAN_MARK_POISON),
|
|
3371 build_fold_addr_expr (shadow_var), size);
|
|
3372
|
|
3373 gimple *use;
|
|
3374 imm_use_iterator imm_iter;
|
|
3375 FOR_EACH_IMM_USE_STMT (use, imm_iter, poisoned_var)
|
|
3376 {
|
|
3377 if (is_gimple_debug (use))
|
|
3378 continue;
|
|
3379
|
|
3380 int nargs;
|
|
3381 bool store_p = gimple_call_internal_p (use, IFN_ASAN_POISON_USE);
|
|
3382 tree fun = report_error_func (store_p, recover_p, tree_to_uhwi (size),
|
|
3383 &nargs);
|
|
3384
|
|
3385 gcall *call = gimple_build_call (fun, 1,
|
|
3386 build_fold_addr_expr (shadow_var));
|
|
3387 gimple_set_location (call, gimple_location (use));
|
|
3388 gimple *call_to_insert = call;
|
|
3389
|
|
3390 /* The USE can be a gimple PHI node. If so, insert the call on
|
|
3391 all edges leading to the PHI node. */
|
|
3392 if (is_a <gphi *> (use))
|
|
3393 {
|
|
3394 gphi *phi = dyn_cast<gphi *> (use);
|
|
3395 for (unsigned i = 0; i < gimple_phi_num_args (phi); ++i)
|
|
3396 if (gimple_phi_arg_def (phi, i) == poisoned_var)
|
|
3397 {
|
|
3398 edge e = gimple_phi_arg_edge (phi, i);
|
|
3399
|
|
3400 /* Do not insert on an edge we can't split. */
|
|
3401 if (e->flags & EDGE_ABNORMAL)
|
|
3402 continue;
|
|
3403
|
|
3404 if (call_to_insert == NULL)
|
|
3405 call_to_insert = gimple_copy (call);
|
|
3406
|
|
3407 gsi_insert_seq_on_edge (e, call_to_insert);
|
|
3408 *need_commit_edge_insert = true;
|
|
3409 call_to_insert = NULL;
|
|
3410 }
|
|
3411 }
|
|
3412 else
|
|
3413 {
|
|
3414 gimple_stmt_iterator gsi = gsi_for_stmt (use);
|
|
3415 if (store_p)
|
|
3416 gsi_replace (&gsi, call, true);
|
|
3417 else
|
|
3418 gsi_insert_before (&gsi, call, GSI_NEW_STMT);
|
|
3419 }
|
|
3420 }
|
|
3421
|
|
3422 SSA_NAME_IS_DEFAULT_DEF (poisoned_var) = true;
|
|
3423 SSA_NAME_DEF_STMT (poisoned_var) = gimple_build_nop ();
|
|
3424 gsi_replace (iter, poison_call, false);
|
|
3425
|
|
3426 return true;
|
|
3427 }
|
|
3428
|
|
3429 /* Instrument the current function. */
|
|
3430
|
|
3431 static unsigned int
|
|
3432 asan_instrument (void)
|
|
3433 {
|
|
3434 if (shadow_ptr_types[0] == NULL_TREE)
|
|
3435 asan_init_shadow_ptr_types ();
|
|
3436 transform_statements ();
|
|
3437 last_alloca_addr = NULL_TREE;
|
|
3438 return 0;
|
|
3439 }
|
|
3440
|
|
3441 static bool
|
|
3442 gate_asan (void)
|
|
3443 {
|
|
3444 return sanitize_flags_p (SANITIZE_ADDRESS);
|
|
3445 }
|
|
3446
|
|
3447 namespace {
|
|
3448
|
|
3449 const pass_data pass_data_asan =
|
|
3450 {
|
|
3451 GIMPLE_PASS, /* type */
|
|
3452 "asan", /* name */
|
|
3453 OPTGROUP_NONE, /* optinfo_flags */
|
|
3454 TV_NONE, /* tv_id */
|
|
3455 ( PROP_ssa | PROP_cfg | PROP_gimple_leh ), /* properties_required */
|
|
3456 0, /* properties_provided */
|
|
3457 0, /* properties_destroyed */
|
|
3458 0, /* todo_flags_start */
|
|
3459 TODO_update_ssa, /* todo_flags_finish */
|
|
3460 };
|
|
3461
|
|
3462 class pass_asan : public gimple_opt_pass
|
|
3463 {
|
|
3464 public:
|
|
3465 pass_asan (gcc::context *ctxt)
|
|
3466 : gimple_opt_pass (pass_data_asan, ctxt)
|
|
3467 {}
|
|
3468
|
|
3469 /* opt_pass methods: */
|
|
3470 opt_pass * clone () { return new pass_asan (m_ctxt); }
|
|
3471 virtual bool gate (function *) { return gate_asan (); }
|
|
3472 virtual unsigned int execute (function *) { return asan_instrument (); }
|
|
3473
|
|
3474 }; // class pass_asan
|
|
3475
|
|
3476 } // anon namespace
|
|
3477
|
|
3478 gimple_opt_pass *
|
|
3479 make_pass_asan (gcc::context *ctxt)
|
|
3480 {
|
|
3481 return new pass_asan (ctxt);
|
|
3482 }
|
|
3483
|
|
3484 namespace {
|
|
3485
|
|
3486 const pass_data pass_data_asan_O0 =
|
|
3487 {
|
|
3488 GIMPLE_PASS, /* type */
|
|
3489 "asan0", /* name */
|
|
3490 OPTGROUP_NONE, /* optinfo_flags */
|
|
3491 TV_NONE, /* tv_id */
|
|
3492 ( PROP_ssa | PROP_cfg | PROP_gimple_leh ), /* properties_required */
|
|
3493 0, /* properties_provided */
|
|
3494 0, /* properties_destroyed */
|
|
3495 0, /* todo_flags_start */
|
|
3496 TODO_update_ssa, /* todo_flags_finish */
|
|
3497 };
|
|
3498
|
|
3499 class pass_asan_O0 : public gimple_opt_pass
|
|
3500 {
|
|
3501 public:
|
|
3502 pass_asan_O0 (gcc::context *ctxt)
|
|
3503 : gimple_opt_pass (pass_data_asan_O0, ctxt)
|
|
3504 {}
|
|
3505
|
|
3506 /* opt_pass methods: */
|
|
3507 virtual bool gate (function *) { return !optimize && gate_asan (); }
|
|
3508 virtual unsigned int execute (function *) { return asan_instrument (); }
|
|
3509
|
|
3510 }; // class pass_asan_O0
|
|
3511
|
|
3512 } // anon namespace
|
|
3513
|
|
3514 gimple_opt_pass *
|
|
3515 make_pass_asan_O0 (gcc::context *ctxt)
|
|
3516 {
|
|
3517 return new pass_asan_O0 (ctxt);
|
|
3518 }
|
|
3519
|
|
3520 #include "gt-asan.h"
|