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0
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1 /*
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2 * Copyright 1999-2007 Sun Microsystems, Inc. All Rights Reserved.
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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4 *
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5 * This code is free software; you can redistribute it and/or modify it
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6 * under the terms of the GNU General Public License version 2 only, as
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7 * published by the Free Software Foundation.
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8 *
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9 * This code is distributed in the hope that it will be useful, but WITHOUT
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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12 * version 2 for more details (a copy is included in the LICENSE file that
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13 * accompanied this code).
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14 *
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15 * You should have received a copy of the GNU General Public License version
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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18 *
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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20 * CA 95054 USA or visit www.sun.com if you need additional information or
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21 * have any questions.
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22 *
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23 */
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24
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25 // do not include precompiled header file
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26 # include "incls/_os_linux_x86.cpp.incl"
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27
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28 // put OS-includes here
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29 # include <sys/types.h>
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30 # include <sys/mman.h>
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31 # include <pthread.h>
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32 # include <signal.h>
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33 # include <errno.h>
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34 # include <dlfcn.h>
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35 # include <stdlib.h>
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36 # include <stdio.h>
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37 # include <unistd.h>
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38 # include <sys/resource.h>
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39 # include <pthread.h>
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40 # include <sys/stat.h>
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41 # include <sys/time.h>
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42 # include <sys/utsname.h>
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43 # include <sys/socket.h>
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44 # include <sys/wait.h>
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45 # include <pwd.h>
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46 # include <poll.h>
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47 # include <ucontext.h>
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48 # include <fpu_control.h>
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49
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50 #ifdef AMD64
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51 #define REG_SP REG_RSP
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52 #define REG_PC REG_RIP
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53 #define REG_FP REG_RBP
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54 #define SPELL_REG_SP "rsp"
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55 #define SPELL_REG_FP "rbp"
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56 #else
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57 #define REG_SP REG_UESP
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58 #define REG_PC REG_EIP
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59 #define REG_FP REG_EBP
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60 #define SPELL_REG_SP "esp"
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61 #define SPELL_REG_FP "ebp"
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62 #endif // AMD64
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63
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64 address os::current_stack_pointer() {
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65 register void *esp __asm__ (SPELL_REG_SP);
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66 return (address) esp;
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67 }
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68
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69 char* os::non_memory_address_word() {
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70 // Must never look like an address returned by reserve_memory,
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71 // even in its subfields (as defined by the CPU immediate fields,
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72 // if the CPU splits constants across multiple instructions).
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73
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74 return (char*) -1;
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75 }
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76
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77 void os::initialize_thread() {
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78 // Nothing to do.
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79 }
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80
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81 address os::Linux::ucontext_get_pc(ucontext_t * uc) {
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82 return (address)uc->uc_mcontext.gregs[REG_PC];
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83 }
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84
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85 intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) {
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86 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
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87 }
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88
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89 intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) {
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90 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
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91 }
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92
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93 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
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94 // is currently interrupted by SIGPROF.
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95 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
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96 // frames. Currently we don't do that on Linux, so it's the same as
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97 // os::fetch_frame_from_context().
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98 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
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99 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
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100
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101 assert(thread != NULL, "just checking");
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102 assert(ret_sp != NULL, "just checking");
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103 assert(ret_fp != NULL, "just checking");
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104
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105 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
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106 }
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107
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108 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
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109 intptr_t** ret_sp, intptr_t** ret_fp) {
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110
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111 ExtendedPC epc;
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112 ucontext_t* uc = (ucontext_t*)ucVoid;
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113
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114 if (uc != NULL) {
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115 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
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116 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc);
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117 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc);
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118 } else {
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119 // construct empty ExtendedPC for return value checking
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120 epc = ExtendedPC(NULL);
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121 if (ret_sp) *ret_sp = (intptr_t *)NULL;
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122 if (ret_fp) *ret_fp = (intptr_t *)NULL;
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123 }
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124
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125 return epc;
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126 }
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127
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128 frame os::fetch_frame_from_context(void* ucVoid) {
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129 intptr_t* sp;
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130 intptr_t* fp;
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131 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
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132 return frame(sp, fp, epc.pc());
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133 }
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134
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135 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get
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136 // turned off by -fomit-frame-pointer,
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137 frame os::get_sender_for_C_frame(frame* fr) {
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138 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
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139 }
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140
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141 intptr_t* _get_previous_fp() {
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142 register intptr_t **ebp __asm__ (SPELL_REG_FP);
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143 return (intptr_t*) *ebp; // we want what it points to.
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144 }
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145
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146
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147 frame os::current_frame() {
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148 intptr_t* fp = _get_previous_fp();
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149 frame myframe((intptr_t*)os::current_stack_pointer(),
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150 (intptr_t*)fp,
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151 CAST_FROM_FN_PTR(address, os::current_frame));
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152 if (os::is_first_C_frame(&myframe)) {
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153 // stack is not walkable
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154 return frame(NULL, NULL, NULL);
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155 } else {
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156 return os::get_sender_for_C_frame(&myframe);
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157 }
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158 }
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159
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160
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161 // Utility functions
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162
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163 julong os::allocatable_physical_memory(julong size) {
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164 #ifdef AMD64
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165 return size;
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166 #else
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167 julong result = MIN2(size, (julong)3800*M);
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168 if (!is_allocatable(result)) {
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169 // See comments under solaris for alignment considerations
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170 julong reasonable_size = (julong)2*G - 2 * os::vm_page_size();
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171 result = MIN2(size, reasonable_size);
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172 }
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173 return result;
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174 #endif // AMD64
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175 }
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176
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177 // From IA32 System Programming Guide
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178 enum {
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179 trap_page_fault = 0xE
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180 };
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181
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182 extern "C" void Fetch32PFI () ;
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183 extern "C" void Fetch32Resume () ;
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184 #ifdef AMD64
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185 extern "C" void FetchNPFI () ;
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186 extern "C" void FetchNResume () ;
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187 #endif // AMD64
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188
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189 extern "C" int
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190 JVM_handle_linux_signal(int sig,
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191 siginfo_t* info,
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192 void* ucVoid,
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193 int abort_if_unrecognized) {
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194 ucontext_t* uc = (ucontext_t*) ucVoid;
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195
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196 Thread* t = ThreadLocalStorage::get_thread_slow();
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197
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198 SignalHandlerMark shm(t);
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199
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200 // Note: it's not uncommon that JNI code uses signal/sigset to install
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201 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
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202 // or have a SIGILL handler when detecting CPU type). When that happens,
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203 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
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204 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
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205 // that do not require siginfo/ucontext first.
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206
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207 if (sig == SIGPIPE || sig == SIGXFSZ) {
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208 // allow chained handler to go first
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209 if (os::Linux::chained_handler(sig, info, ucVoid)) {
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210 return true;
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211 } else {
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212 if (PrintMiscellaneous && (WizardMode || Verbose)) {
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213 char buf[64];
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214 warning("Ignoring %s - see bugs 4229104 or 646499219",
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215 os::exception_name(sig, buf, sizeof(buf)));
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216 }
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217 return true;
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218 }
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219 }
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220
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221 JavaThread* thread = NULL;
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222 VMThread* vmthread = NULL;
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223 if (os::Linux::signal_handlers_are_installed) {
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224 if (t != NULL ){
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225 if(t->is_Java_thread()) {
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226 thread = (JavaThread*)t;
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227 }
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228 else if(t->is_VM_thread()){
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229 vmthread = (VMThread *)t;
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230 }
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231 }
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232 }
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233 /*
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234 NOTE: does not seem to work on linux.
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235 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
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236 // can't decode this kind of signal
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237 info = NULL;
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238 } else {
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239 assert(sig == info->si_signo, "bad siginfo");
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240 }
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241 */
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242 // decide if this trap can be handled by a stub
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243 address stub = NULL;
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244
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245 address pc = NULL;
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246
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247 //%note os_trap_1
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248 if (info != NULL && uc != NULL && thread != NULL) {
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249 pc = (address) os::Linux::ucontext_get_pc(uc);
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250
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251 if (pc == (address) Fetch32PFI) {
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252 uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ;
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253 return 1 ;
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254 }
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255 #ifdef AMD64
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256 if (pc == (address) FetchNPFI) {
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257 uc->uc_mcontext.gregs[REG_PC] = intptr_t (FetchNResume) ;
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258 return 1 ;
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259 }
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260 #endif // AMD64
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261
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262 // Handle ALL stack overflow variations here
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263 if (sig == SIGSEGV) {
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264 address addr = (address) info->si_addr;
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265
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266 // check if fault address is within thread stack
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267 if (addr < thread->stack_base() &&
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268 addr >= thread->stack_base() - thread->stack_size()) {
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269 // stack overflow
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270 if (thread->in_stack_yellow_zone(addr)) {
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271 thread->disable_stack_yellow_zone();
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272 if (thread->thread_state() == _thread_in_Java) {
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273 // Throw a stack overflow exception. Guard pages will be reenabled
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274 // while unwinding the stack.
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275 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
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276 } else {
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277 // Thread was in the vm or native code. Return and try to finish.
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278 return 1;
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279 }
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280 } else if (thread->in_stack_red_zone(addr)) {
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281 // Fatal red zone violation. Disable the guard pages and fall through
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282 // to handle_unexpected_exception way down below.
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283 thread->disable_stack_red_zone();
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284 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
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285 } else {
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286 // Accessing stack address below sp may cause SEGV if current
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287 // thread has MAP_GROWSDOWN stack. This should only happen when
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288 // current thread was created by user code with MAP_GROWSDOWN flag
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289 // and then attached to VM. See notes in os_linux.cpp.
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290 if (thread->osthread()->expanding_stack() == 0) {
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291 thread->osthread()->set_expanding_stack();
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292 if (os::Linux::manually_expand_stack(thread, addr)) {
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293 thread->osthread()->clear_expanding_stack();
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294 return 1;
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295 }
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296 thread->osthread()->clear_expanding_stack();
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297 } else {
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298 fatal("recursive segv. expanding stack.");
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299 }
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300 }
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301 }
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302 }
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303
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304 if (thread->thread_state() == _thread_in_Java) {
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305 // Java thread running in Java code => find exception handler if any
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306 // a fault inside compiled code, the interpreter, or a stub
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307
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308 if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
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309 stub = SharedRuntime::get_poll_stub(pc);
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310 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
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311 // BugId 4454115: A read from a MappedByteBuffer can fault
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312 // here if the underlying file has been truncated.
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313 // Do not crash the VM in such a case.
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314 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
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315 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
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316 if (nm != NULL && nm->has_unsafe_access()) {
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317 stub = StubRoutines::handler_for_unsafe_access();
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318 }
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319 }
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320 else
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321
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322 #ifdef AMD64
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323 if (sig == SIGFPE &&
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324 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
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325 stub =
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326 SharedRuntime::
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327 continuation_for_implicit_exception(thread,
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328 pc,
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329 SharedRuntime::
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330 IMPLICIT_DIVIDE_BY_ZERO);
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331 #else
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332 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) {
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333 // HACK: si_code does not work on linux 2.2.12-20!!!
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334 int op = pc[0];
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335 if (op == 0xDB) {
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336 // FIST
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337 // TODO: The encoding of D2I in i486.ad can cause an exception
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338 // prior to the fist instruction if there was an invalid operation
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339 // pending. We want to dismiss that exception. From the win_32
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340 // side it also seems that if it really was the fist causing
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341 // the exception that we do the d2i by hand with different
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342 // rounding. Seems kind of weird.
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343 // NOTE: that we take the exception at the NEXT floating point instruction.
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344 assert(pc[0] == 0xDB, "not a FIST opcode");
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345 assert(pc[1] == 0x14, "not a FIST opcode");
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346 assert(pc[2] == 0x24, "not a FIST opcode");
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347 return true;
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348 } else if (op == 0xF7) {
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349 // IDIV
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350 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
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351 } else {
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352 // TODO: handle more cases if we are using other x86 instructions
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353 // that can generate SIGFPE signal on linux.
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354 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
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355 fatal("please update this code.");
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356 }
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357 #endif // AMD64
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358 } else if (sig == SIGSEGV &&
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359 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
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360 // Determination of interpreter/vtable stub/compiled code null exception
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361 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
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362 }
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363 } else if (thread->thread_state() == _thread_in_vm &&
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364 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
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365 thread->doing_unsafe_access()) {
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366 stub = StubRoutines::handler_for_unsafe_access();
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367 }
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368
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369 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
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370 // and the heap gets shrunk before the field access.
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371 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
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372 address addr = JNI_FastGetField::find_slowcase_pc(pc);
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373 if (addr != (address)-1) {
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374 stub = addr;
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375 }
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376 }
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377
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378 // Check to see if we caught the safepoint code in the
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379 // process of write protecting the memory serialization page.
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380 // It write enables the page immediately after protecting it
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381 // so we can just return to retry the write.
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382 if ((sig == SIGSEGV) &&
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383 os::is_memory_serialize_page(thread, (address) info->si_addr)) {
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384 // Block current thread until the memory serialize page permission restored.
|
|
|
385 os::block_on_serialize_page_trap();
|
|
|
386 return true;
|
|
|
387 }
|
|
|
388 }
|
|
|
389
|
|
|
390 #ifndef AMD64
|
|
|
391 // Execution protection violation
|
|
|
392 //
|
|
|
393 // This should be kept as the last step in the triage. We don't
|
|
|
394 // have a dedicated trap number for a no-execute fault, so be
|
|
|
395 // conservative and allow other handlers the first shot.
|
|
|
396 //
|
|
|
397 // Note: We don't test that info->si_code == SEGV_ACCERR here.
|
|
|
398 // this si_code is so generic that it is almost meaningless; and
|
|
|
399 // the si_code for this condition may change in the future.
|
|
|
400 // Furthermore, a false-positive should be harmless.
|
|
|
401 if (UnguardOnExecutionViolation > 0 &&
|
|
|
402 (sig == SIGSEGV || sig == SIGBUS) &&
|
|
|
403 uc->uc_mcontext.gregs[REG_TRAPNO] == trap_page_fault) {
|
|
|
404 int page_size = os::vm_page_size();
|
|
|
405 address addr = (address) info->si_addr;
|
|
|
406 address pc = os::Linux::ucontext_get_pc(uc);
|
|
|
407 // Make sure the pc and the faulting address are sane.
|
|
|
408 //
|
|
|
409 // If an instruction spans a page boundary, and the page containing
|
|
|
410 // the beginning of the instruction is executable but the following
|
|
|
411 // page is not, the pc and the faulting address might be slightly
|
|
|
412 // different - we still want to unguard the 2nd page in this case.
|
|
|
413 //
|
|
|
414 // 15 bytes seems to be a (very) safe value for max instruction size.
|
|
|
415 bool pc_is_near_addr =
|
|
|
416 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
|
|
|
417 bool instr_spans_page_boundary =
|
|
|
418 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
|
|
|
419 (intptr_t) page_size) > 0);
|
|
|
420
|
|
|
421 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
|
|
|
422 static volatile address last_addr =
|
|
|
423 (address) os::non_memory_address_word();
|
|
|
424
|
|
|
425 // In conservative mode, don't unguard unless the address is in the VM
|
|
|
426 if (addr != last_addr &&
|
|
|
427 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
|
|
|
428
|
|
|
429 // Unguard and retry
|
|
|
430 address page_start =
|
|
|
431 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
|
|
|
432 bool res = os::unguard_memory((char*) page_start, page_size);
|
|
|
433
|
|
|
434 if (PrintMiscellaneous && Verbose) {
|
|
|
435 char buf[256];
|
|
|
436 jio_snprintf(buf, sizeof(buf), "Execution protection violation "
|
|
|
437 "at " INTPTR_FORMAT
|
|
|
438 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
|
|
|
439 page_start, (res ? "success" : "failed"), errno);
|
|
|
440 tty->print_raw_cr(buf);
|
|
|
441 }
|
|
|
442 stub = pc;
|
|
|
443
|
|
|
444 // Set last_addr so if we fault again at the same address, we don't end
|
|
|
445 // up in an endless loop.
|
|
|
446 //
|
|
|
447 // There are two potential complications here. Two threads trapping at
|
|
|
448 // the same address at the same time could cause one of the threads to
|
|
|
449 // think it already unguarded, and abort the VM. Likely very rare.
|
|
|
450 //
|
|
|
451 // The other race involves two threads alternately trapping at
|
|
|
452 // different addresses and failing to unguard the page, resulting in
|
|
|
453 // an endless loop. This condition is probably even more unlikely than
|
|
|
454 // the first.
|
|
|
455 //
|
|
|
456 // Although both cases could be avoided by using locks or thread local
|
|
|
457 // last_addr, these solutions are unnecessary complication: this
|
|
|
458 // handler is a best-effort safety net, not a complete solution. It is
|
|
|
459 // disabled by default and should only be used as a workaround in case
|
|
|
460 // we missed any no-execute-unsafe VM code.
|
|
|
461
|
|
|
462 last_addr = addr;
|
|
|
463 }
|
|
|
464 }
|
|
|
465 }
|
|
|
466 #endif // !AMD64
|
|
|
467
|
|
|
468 if (stub != NULL) {
|
|
|
469 // save all thread context in case we need to restore it
|
|
|
470 if (thread != NULL) thread->set_saved_exception_pc(pc);
|
|
|
471
|
|
|
472 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub;
|
|
|
473 return true;
|
|
|
474 }
|
|
|
475
|
|
|
476 // signal-chaining
|
|
|
477 if (os::Linux::chained_handler(sig, info, ucVoid)) {
|
|
|
478 return true;
|
|
|
479 }
|
|
|
480
|
|
|
481 if (!abort_if_unrecognized) {
|
|
|
482 // caller wants another chance, so give it to him
|
|
|
483 return false;
|
|
|
484 }
|
|
|
485
|
|
|
486 if (pc == NULL && uc != NULL) {
|
|
|
487 pc = os::Linux::ucontext_get_pc(uc);
|
|
|
488 }
|
|
|
489
|
|
|
490 // unmask current signal
|
|
|
491 sigset_t newset;
|
|
|
492 sigemptyset(&newset);
|
|
|
493 sigaddset(&newset, sig);
|
|
|
494 sigprocmask(SIG_UNBLOCK, &newset, NULL);
|
|
|
495
|
|
|
496 VMError err(t, sig, pc, info, ucVoid);
|
|
|
497 err.report_and_die();
|
|
|
498
|
|
|
499 ShouldNotReachHere();
|
|
|
500 }
|
|
|
501
|
|
|
502 void os::Linux::init_thread_fpu_state(void) {
|
|
|
503 #ifndef AMD64
|
|
|
504 // set fpu to 53 bit precision
|
|
|
505 set_fpu_control_word(0x27f);
|
|
|
506 #endif // !AMD64
|
|
|
507 }
|
|
|
508
|
|
|
509 int os::Linux::get_fpu_control_word(void) {
|
|
|
510 #ifdef AMD64
|
|
|
511 return 0;
|
|
|
512 #else
|
|
|
513 int fpu_control;
|
|
|
514 _FPU_GETCW(fpu_control);
|
|
|
515 return fpu_control & 0xffff;
|
|
|
516 #endif // AMD64
|
|
|
517 }
|
|
|
518
|
|
|
519 void os::Linux::set_fpu_control_word(int fpu_control) {
|
|
|
520 #ifndef AMD64
|
|
|
521 _FPU_SETCW(fpu_control);
|
|
|
522 #endif // !AMD64
|
|
|
523 }
|
|
|
524
|
|
|
525 // Check that the linux kernel version is 2.4 or higher since earlier
|
|
|
526 // versions do not support SSE without patches.
|
|
|
527 bool os::supports_sse() {
|
|
|
528 #ifdef AMD64
|
|
|
529 return true;
|
|
|
530 #else
|
|
|
531 struct utsname uts;
|
|
|
532 if( uname(&uts) != 0 ) return false; // uname fails?
|
|
|
533 char *minor_string;
|
|
|
534 int major = strtol(uts.release,&minor_string,10);
|
|
|
535 int minor = strtol(minor_string+1,NULL,10);
|
|
|
536 bool result = (major > 2 || (major==2 && minor >= 4));
|
|
|
537 #ifndef PRODUCT
|
|
|
538 if (PrintMiscellaneous && Verbose) {
|
|
|
539 tty->print("OS version is %d.%d, which %s support SSE/SSE2\n",
|
|
|
540 major,minor, result ? "DOES" : "does NOT");
|
|
|
541 }
|
|
|
542 #endif
|
|
|
543 return result;
|
|
|
544 #endif // AMD64
|
|
|
545 }
|
|
|
546
|
|
|
547 bool os::is_allocatable(size_t bytes) {
|
|
|
548 #ifdef AMD64
|
|
|
549 // unused on amd64?
|
|
|
550 return true;
|
|
|
551 #else
|
|
|
552
|
|
|
553 if (bytes < 2 * G) {
|
|
|
554 return true;
|
|
|
555 }
|
|
|
556
|
|
|
557 char* addr = reserve_memory(bytes, NULL);
|
|
|
558
|
|
|
559 if (addr != NULL) {
|
|
|
560 release_memory(addr, bytes);
|
|
|
561 }
|
|
|
562
|
|
|
563 return addr != NULL;
|
|
|
564 #endif // AMD64
|
|
|
565 }
|
|
|
566
|
|
|
567 ////////////////////////////////////////////////////////////////////////////////
|
|
|
568 // thread stack
|
|
|
569
|
|
|
570 #ifdef AMD64
|
|
|
571 size_t os::Linux::min_stack_allowed = 64 * K;
|
|
|
572
|
|
|
573 // amd64: pthread on amd64 is always in floating stack mode
|
|
|
574 bool os::Linux::supports_variable_stack_size() { return true; }
|
|
|
575 #else
|
|
|
576 size_t os::Linux::min_stack_allowed = (48 DEBUG_ONLY(+4))*K;
|
|
|
577
|
|
|
578 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;})
|
|
|
579
|
|
|
580 // Test if pthread library can support variable thread stack size. LinuxThreads
|
|
|
581 // in fixed stack mode allocates 2M fixed slot for each thread. LinuxThreads
|
|
|
582 // in floating stack mode and NPTL support variable stack size.
|
|
|
583 bool os::Linux::supports_variable_stack_size() {
|
|
|
584 if (os::Linux::is_NPTL()) {
|
|
|
585 // NPTL, yes
|
|
|
586 return true;
|
|
|
587
|
|
|
588 } else {
|
|
|
589 // Note: We can't control default stack size when creating a thread.
|
|
|
590 // If we use non-default stack size (pthread_attr_setstacksize), both
|
|
|
591 // floating stack and non-floating stack LinuxThreads will return the
|
|
|
592 // same value. This makes it impossible to implement this function by
|
|
|
593 // detecting thread stack size directly.
|
|
|
594 //
|
|
|
595 // An alternative approach is to check %gs. Fixed-stack LinuxThreads
|
|
|
596 // do not use %gs, so its value is 0. Floating-stack LinuxThreads use
|
|
|
597 // %gs (either as LDT selector or GDT selector, depending on kernel)
|
|
|
598 // to access thread specific data.
|
|
|
599 //
|
|
|
600 // Note that %gs is a reserved glibc register since early 2001, so
|
|
|
601 // applications are not allowed to change its value (Ulrich Drepper from
|
|
|
602 // Redhat confirmed that all known offenders have been modified to use
|
|
|
603 // either %fs or TSD). In the worst case scenario, when VM is embedded in
|
|
|
604 // a native application that plays with %gs, we might see non-zero %gs
|
|
|
605 // even LinuxThreads is running in fixed stack mode. As the result, we'll
|
|
|
606 // return true and skip _thread_safety_check(), so we may not be able to
|
|
|
607 // detect stack-heap collisions. But otherwise it's harmless.
|
|
|
608 //
|
|
|
609 return (GET_GS() != 0);
|
|
|
610 }
|
|
|
611 }
|
|
|
612 #endif // AMD64
|
|
|
613
|
|
|
614 // return default stack size for thr_type
|
|
|
615 size_t os::Linux::default_stack_size(os::ThreadType thr_type) {
|
|
|
616 // default stack size (compiler thread needs larger stack)
|
|
|
617 #ifdef AMD64
|
|
|
618 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
|
|
|
619 #else
|
|
|
620 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
|
|
|
621 #endif // AMD64
|
|
|
622 return s;
|
|
|
623 }
|
|
|
624
|
|
|
625 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
|
|
|
626 // Creating guard page is very expensive. Java thread has HotSpot
|
|
|
627 // guard page, only enable glibc guard page for non-Java threads.
|
|
|
628 return (thr_type == java_thread ? 0 : page_size());
|
|
|
629 }
|
|
|
630
|
|
|
631 // Java thread:
|
|
|
632 //
|
|
|
633 // Low memory addresses
|
|
|
634 // +------------------------+
|
|
|
635 // | |\ JavaThread created by VM does not have glibc
|
|
|
636 // | glibc guard page | - guard, attached Java thread usually has
|
|
|
637 // | |/ 1 page glibc guard.
|
|
|
638 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
|
|
|
639 // | |\
|
|
|
640 // | HotSpot Guard Pages | - red and yellow pages
|
|
|
641 // | |/
|
|
|
642 // +------------------------+ JavaThread::stack_yellow_zone_base()
|
|
|
643 // | |\
|
|
|
644 // | Normal Stack | -
|
|
|
645 // | |/
|
|
|
646 // P2 +------------------------+ Thread::stack_base()
|
|
|
647 //
|
|
|
648 // Non-Java thread:
|
|
|
649 //
|
|
|
650 // Low memory addresses
|
|
|
651 // +------------------------+
|
|
|
652 // | |\
|
|
|
653 // | glibc guard page | - usually 1 page
|
|
|
654 // | |/
|
|
|
655 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
|
|
|
656 // | |\
|
|
|
657 // | Normal Stack | -
|
|
|
658 // | |/
|
|
|
659 // P2 +------------------------+ Thread::stack_base()
|
|
|
660 //
|
|
|
661 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
|
|
|
662 // pthread_attr_getstack()
|
|
|
663
|
|
|
664 static void current_stack_region(address * bottom, size_t * size) {
|
|
|
665 if (os::Linux::is_initial_thread()) {
|
|
|
666 // initial thread needs special handling because pthread_getattr_np()
|
|
|
667 // may return bogus value.
|
|
|
668 *bottom = os::Linux::initial_thread_stack_bottom();
|
|
|
669 *size = os::Linux::initial_thread_stack_size();
|
|
|
670 } else {
|
|
|
671 pthread_attr_t attr;
|
|
|
672
|
|
|
673 int rslt = pthread_getattr_np(pthread_self(), &attr);
|
|
|
674
|
|
|
675 // JVM needs to know exact stack location, abort if it fails
|
|
|
676 if (rslt != 0) {
|
|
|
677 if (rslt == ENOMEM) {
|
|
|
678 vm_exit_out_of_memory(0, "pthread_getattr_np");
|
|
|
679 } else {
|
|
|
680 fatal1("pthread_getattr_np failed with errno = %d", rslt);
|
|
|
681 }
|
|
|
682 }
|
|
|
683
|
|
|
684 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
|
|
|
685 fatal("Can not locate current stack attributes!");
|
|
|
686 }
|
|
|
687
|
|
|
688 pthread_attr_destroy(&attr);
|
|
|
689
|
|
|
690 }
|
|
|
691 assert(os::current_stack_pointer() >= *bottom &&
|
|
|
692 os::current_stack_pointer() < *bottom + *size, "just checking");
|
|
|
693 }
|
|
|
694
|
|
|
695 address os::current_stack_base() {
|
|
|
696 address bottom;
|
|
|
697 size_t size;
|
|
|
698 current_stack_region(&bottom, &size);
|
|
|
699 return (bottom + size);
|
|
|
700 }
|
|
|
701
|
|
|
702 size_t os::current_stack_size() {
|
|
|
703 // stack size includes normal stack and HotSpot guard pages
|
|
|
704 address bottom;
|
|
|
705 size_t size;
|
|
|
706 current_stack_region(&bottom, &size);
|
|
|
707 return size;
|
|
|
708 }
|
|
|
709
|
|
|
710 /////////////////////////////////////////////////////////////////////////////
|
|
|
711 // helper functions for fatal error handler
|
|
|
712
|
|
|
713 void os::print_context(outputStream *st, void *context) {
|
|
|
714 if (context == NULL) return;
|
|
|
715
|
|
|
716 ucontext_t *uc = (ucontext_t*)context;
|
|
|
717 st->print_cr("Registers:");
|
|
|
718 #ifdef AMD64
|
|
|
719 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
|
|
|
720 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
|
|
|
721 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
|
|
|
722 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
|
|
|
723 st->cr();
|
|
|
724 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
|
|
|
725 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
|
|
|
726 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
|
|
|
727 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
|
|
|
728 st->cr();
|
|
|
729 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
|
|
|
730 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
|
|
|
731 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
|
|
|
732 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
|
|
|
733 st->cr();
|
|
|
734 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
|
|
|
735 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
|
|
|
736 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
|
|
|
737 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
|
|
|
738 st->cr();
|
|
|
739 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
|
|
|
740 st->print(", EFL=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]);
|
|
|
741 st->print(", CSGSFS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_CSGSFS]);
|
|
|
742 st->print(", ERR=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ERR]);
|
|
|
743 st->cr();
|
|
|
744 st->print(" TRAPNO=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_TRAPNO]);
|
|
|
745 #else
|
|
|
746 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EAX]);
|
|
|
747 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBX]);
|
|
|
748 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ECX]);
|
|
|
749 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDX]);
|
|
|
750 st->cr();
|
|
|
751 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_UESP]);
|
|
|
752 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBP]);
|
|
|
753 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ESI]);
|
|
|
754 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDI]);
|
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755 st->cr();
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756 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EIP]);
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757 st->print(", CR2=" INTPTR_FORMAT, uc->uc_mcontext.cr2);
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758 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]);
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759 #endif // AMD64
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760 st->cr();
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761 st->cr();
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762
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763 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
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764 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
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765 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
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766 st->cr();
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767
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768 // Note: it may be unsafe to inspect memory near pc. For example, pc may
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769 // point to garbage if entry point in an nmethod is corrupted. Leave
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770 // this at the end, and hope for the best.
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|
771 address pc = os::Linux::ucontext_get_pc(uc);
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772 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
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773 print_hex_dump(st, pc - 16, pc + 16, sizeof(char));
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774 }
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775
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776 void os::setup_fpu() {
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777 #ifndef AMD64
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778 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
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779 __asm__ volatile ( "fldcw (%0)" :
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780 : "r" (fpu_cntrl) : "memory");
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781 #endif // !AMD64
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782 }
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