1 /*
   2  * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 // no precompiled headers
  26 #include "asm/macroAssembler.hpp"
  27 #include "classfile/classLoader.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "classfile/vmSymbols.hpp"
  30 #include "code/codeCache.hpp"
  31 #include "code/icBuffer.hpp"
  32 #include "code/vtableStubs.hpp"
  33 #include "interpreter/interpreter.hpp"
  34 #include "jvm_bsd.h"
  35 #include "memory/allocation.inline.hpp"
  36 #include "mutex_bsd.inline.hpp"
  37 #include "os_share_bsd.hpp"
  38 #include "prims/jniFastGetField.hpp"
  39 #include "prims/jvm.h"
  40 #include "prims/jvm_misc.hpp"
  41 #include "runtime/arguments.hpp"
  42 #include "runtime/extendedPC.hpp"
  43 #include "runtime/frame.inline.hpp"
  44 #include "runtime/interfaceSupport.hpp"
  45 #include "runtime/java.hpp"
  46 #include "runtime/javaCalls.hpp"
  47 #include "runtime/mutexLocker.hpp"
  48 #include "runtime/osThread.hpp"
  49 #include "runtime/sharedRuntime.hpp"
  50 #include "runtime/stubRoutines.hpp"
  51 #include "runtime/thread.inline.hpp"
  52 #include "runtime/timer.hpp"
  53 #include "utilities/events.hpp"
  54 #include "utilities/vmError.hpp"
  55 
  56 // put OS-includes here
  57 # include <sys/types.h>
  58 # include <sys/mman.h>
  59 # include <pthread.h>
  60 # include <signal.h>
  61 # include <errno.h>
  62 # include <dlfcn.h>
  63 # include <stdlib.h>
  64 # include <stdio.h>
  65 # include <unistd.h>
  66 # include <sys/resource.h>
  67 # include <pthread.h>
  68 # include <sys/stat.h>
  69 # include <sys/time.h>
  70 # include <sys/utsname.h>
  71 # include <sys/socket.h>
  72 # include <sys/wait.h>
  73 # include <pwd.h>
  74 # include <poll.h>
  75 #ifndef __OpenBSD__
  76 # include <ucontext.h>
  77 #endif
  78 
  79 #if !defined(__APPLE__) && !defined(__NetBSD__)
  80 # include <pthread_np.h>
  81 #endif
  82 
  83 // needed by current_stack_region() workaround for Mavericks
  84 #if defined(__APPLE__)
  85 # include <errno.h>
  86 # include <sys/types.h>
  87 # include <sys/sysctl.h>
  88 # define DEFAULT_MAIN_THREAD_STACK_PAGES 2048
  89 # define OS_X_10_9_0_KERNEL_MAJOR_VERSION 13
  90 #endif
  91 
  92 #ifdef AMD64
  93 #define SPELL_REG_SP "rsp"
  94 #define SPELL_REG_FP "rbp"
  95 #else
  96 #define SPELL_REG_SP "esp"
  97 #define SPELL_REG_FP "ebp"
  98 #endif // AMD64
  99 
 100 #ifdef __FreeBSD__
 101 # define context_trapno uc_mcontext.mc_trapno
 102 # ifdef AMD64
 103 #  define context_pc uc_mcontext.mc_rip
 104 #  define context_sp uc_mcontext.mc_rsp
 105 #  define context_fp uc_mcontext.mc_rbp
 106 #  define context_rip uc_mcontext.mc_rip
 107 #  define context_rsp uc_mcontext.mc_rsp
 108 #  define context_rbp uc_mcontext.mc_rbp
 109 #  define context_rax uc_mcontext.mc_rax
 110 #  define context_rbx uc_mcontext.mc_rbx
 111 #  define context_rcx uc_mcontext.mc_rcx
 112 #  define context_rdx uc_mcontext.mc_rdx
 113 #  define context_rsi uc_mcontext.mc_rsi
 114 #  define context_rdi uc_mcontext.mc_rdi
 115 #  define context_r8  uc_mcontext.mc_r8
 116 #  define context_r9  uc_mcontext.mc_r9
 117 #  define context_r10 uc_mcontext.mc_r10
 118 #  define context_r11 uc_mcontext.mc_r11
 119 #  define context_r12 uc_mcontext.mc_r12
 120 #  define context_r13 uc_mcontext.mc_r13
 121 #  define context_r14 uc_mcontext.mc_r14
 122 #  define context_r15 uc_mcontext.mc_r15
 123 #  define context_flags uc_mcontext.mc_flags
 124 #  define context_err uc_mcontext.mc_err
 125 # else
 126 #  define context_pc uc_mcontext.mc_eip
 127 #  define context_sp uc_mcontext.mc_esp
 128 #  define context_fp uc_mcontext.mc_ebp
 129 #  define context_eip uc_mcontext.mc_eip
 130 #  define context_esp uc_mcontext.mc_esp
 131 #  define context_eax uc_mcontext.mc_eax
 132 #  define context_ebx uc_mcontext.mc_ebx
 133 #  define context_ecx uc_mcontext.mc_ecx
 134 #  define context_edx uc_mcontext.mc_edx
 135 #  define context_ebp uc_mcontext.mc_ebp
 136 #  define context_esi uc_mcontext.mc_esi
 137 #  define context_edi uc_mcontext.mc_edi
 138 #  define context_eflags uc_mcontext.mc_eflags
 139 #  define context_trapno uc_mcontext.mc_trapno
 140 # endif
 141 #endif
 142 
 143 #ifdef __APPLE__
 144 # if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
 145   // 10.5 UNIX03 member name prefixes
 146   #define DU3_PREFIX(s, m) __ ## s.__ ## m
 147 # else
 148   #define DU3_PREFIX(s, m) s ## . ## m
 149 # endif
 150 
 151 # ifdef AMD64
 152 #  define context_pc context_rip
 153 #  define context_sp context_rsp
 154 #  define context_fp context_rbp
 155 #  define context_rip uc_mcontext->DU3_PREFIX(ss,rip)
 156 #  define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp)
 157 #  define context_rax uc_mcontext->DU3_PREFIX(ss,rax)
 158 #  define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx)
 159 #  define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx)
 160 #  define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx)
 161 #  define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp)
 162 #  define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi)
 163 #  define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi)
 164 #  define context_r8  uc_mcontext->DU3_PREFIX(ss,r8)
 165 #  define context_r9  uc_mcontext->DU3_PREFIX(ss,r9)
 166 #  define context_r10 uc_mcontext->DU3_PREFIX(ss,r10)
 167 #  define context_r11 uc_mcontext->DU3_PREFIX(ss,r11)
 168 #  define context_r12 uc_mcontext->DU3_PREFIX(ss,r12)
 169 #  define context_r13 uc_mcontext->DU3_PREFIX(ss,r13)
 170 #  define context_r14 uc_mcontext->DU3_PREFIX(ss,r14)
 171 #  define context_r15 uc_mcontext->DU3_PREFIX(ss,r15)
 172 #  define context_flags uc_mcontext->DU3_PREFIX(ss,rflags)
 173 #  define context_trapno uc_mcontext->DU3_PREFIX(es,trapno)
 174 #  define context_err uc_mcontext->DU3_PREFIX(es,err)
 175 # else
 176 #  define context_pc context_eip
 177 #  define context_sp context_esp
 178 #  define context_fp context_ebp
 179 #  define context_eip uc_mcontext->DU3_PREFIX(ss,eip)
 180 #  define context_esp uc_mcontext->DU3_PREFIX(ss,esp)
 181 #  define context_eax uc_mcontext->DU3_PREFIX(ss,eax)
 182 #  define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx)
 183 #  define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx)
 184 #  define context_edx uc_mcontext->DU3_PREFIX(ss,edx)
 185 #  define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp)
 186 #  define context_esi uc_mcontext->DU3_PREFIX(ss,esi)
 187 #  define context_edi uc_mcontext->DU3_PREFIX(ss,edi)
 188 #  define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags)
 189 #  define context_trapno uc_mcontext->DU3_PREFIX(es,trapno)
 190 # endif
 191 #endif
 192 
 193 #ifdef __OpenBSD__
 194 # define context_trapno sc_trapno
 195 # ifdef AMD64
 196 #  define context_pc sc_rip
 197 #  define context_sp sc_rsp
 198 #  define context_fp sc_rbp
 199 #  define context_rip sc_rip
 200 #  define context_rsp sc_rsp
 201 #  define context_rbp sc_rbp
 202 #  define context_rax sc_rax
 203 #  define context_rbx sc_rbx
 204 #  define context_rcx sc_rcx
 205 #  define context_rdx sc_rdx
 206 #  define context_rsi sc_rsi
 207 #  define context_rdi sc_rdi
 208 #  define context_r8  sc_r8
 209 #  define context_r9  sc_r9
 210 #  define context_r10 sc_r10
 211 #  define context_r11 sc_r11
 212 #  define context_r12 sc_r12
 213 #  define context_r13 sc_r13
 214 #  define context_r14 sc_r14
 215 #  define context_r15 sc_r15
 216 #  define context_flags sc_rflags
 217 #  define context_err sc_err
 218 # else
 219 #  define context_pc sc_eip
 220 #  define context_sp sc_esp
 221 #  define context_fp sc_ebp
 222 #  define context_eip sc_eip
 223 #  define context_esp sc_esp
 224 #  define context_eax sc_eax
 225 #  define context_ebx sc_ebx
 226 #  define context_ecx sc_ecx
 227 #  define context_edx sc_edx
 228 #  define context_ebp sc_ebp
 229 #  define context_esi sc_esi
 230 #  define context_edi sc_edi
 231 #  define context_eflags sc_eflags
 232 #  define context_trapno sc_trapno
 233 # endif
 234 #endif
 235 
 236 #ifdef __NetBSD__
 237 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO]
 238 # ifdef AMD64
 239 #  define __register_t __greg_t
 240 #  define context_pc uc_mcontext.__gregs[_REG_RIP]
 241 #  define context_sp uc_mcontext.__gregs[_REG_URSP]
 242 #  define context_fp uc_mcontext.__gregs[_REG_RBP]
 243 #  define context_rip uc_mcontext.__gregs[_REG_RIP]
 244 #  define context_rsp uc_mcontext.__gregs[_REG_URSP]
 245 #  define context_rax uc_mcontext.__gregs[_REG_RAX]
 246 #  define context_rbx uc_mcontext.__gregs[_REG_RBX]
 247 #  define context_rcx uc_mcontext.__gregs[_REG_RCX]
 248 #  define context_rdx uc_mcontext.__gregs[_REG_RDX]
 249 #  define context_rbp uc_mcontext.__gregs[_REG_RBP]
 250 #  define context_rsi uc_mcontext.__gregs[_REG_RSI]
 251 #  define context_rdi uc_mcontext.__gregs[_REG_RDI]
 252 #  define context_r8  uc_mcontext.__gregs[_REG_R8]
 253 #  define context_r9  uc_mcontext.__gregs[_REG_R9]
 254 #  define context_r10 uc_mcontext.__gregs[_REG_R10]
 255 #  define context_r11 uc_mcontext.__gregs[_REG_R11]
 256 #  define context_r12 uc_mcontext.__gregs[_REG_R12]
 257 #  define context_r13 uc_mcontext.__gregs[_REG_R13]
 258 #  define context_r14 uc_mcontext.__gregs[_REG_R14]
 259 #  define context_r15 uc_mcontext.__gregs[_REG_R15]
 260 #  define context_flags uc_mcontext.__gregs[_REG_RFL]
 261 #  define context_err uc_mcontext.__gregs[_REG_ERR]
 262 # else
 263 #  define context_pc uc_mcontext.__gregs[_REG_EIP]
 264 #  define context_sp uc_mcontext.__gregs[_REG_UESP]
 265 #  define context_fp uc_mcontext.__gregs[_REG_EBP]
 266 #  define context_eip uc_mcontext.__gregs[_REG_EIP]
 267 #  define context_esp uc_mcontext.__gregs[_REG_UESP]
 268 #  define context_eax uc_mcontext.__gregs[_REG_EAX]
 269 #  define context_ebx uc_mcontext.__gregs[_REG_EBX]
 270 #  define context_ecx uc_mcontext.__gregs[_REG_ECX]
 271 #  define context_edx uc_mcontext.__gregs[_REG_EDX]
 272 #  define context_ebp uc_mcontext.__gregs[_REG_EBP]
 273 #  define context_esi uc_mcontext.__gregs[_REG_ESI]
 274 #  define context_edi uc_mcontext.__gregs[_REG_EDI]
 275 #  define context_eflags uc_mcontext.__gregs[_REG_EFL]
 276 #  define context_trapno uc_mcontext.__gregs[_REG_TRAPNO]
 277 # endif
 278 #endif
 279 
 280 address os::current_stack_pointer() {
 281 #if defined(__clang__) || defined(__llvm__)
 282   register void *esp;
 283   __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp));
 284   return (address) esp;
 285 #elif defined(SPARC_WORKS)
 286   register void *esp;
 287   __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp));
 288   return (address) ((char*)esp + sizeof(long)*2);
 289 #else
 290   register void *esp __asm__ (SPELL_REG_SP);
 291   return (address) esp;
 292 #endif
 293 }
 294 
 295 char* os::non_memory_address_word() {
 296   // Must never look like an address returned by reserve_memory,
 297   // even in its subfields (as defined by the CPU immediate fields,
 298   // if the CPU splits constants across multiple instructions).
 299 
 300   return (char*) -1;
 301 }
 302 
 303 void os::initialize_thread(Thread* thr) {
 304 // Nothing to do.
 305 }
 306 
 307 address os::Bsd::ucontext_get_pc(const ucontext_t * uc) {
 308   return (address)uc->context_pc;
 309 }
 310 
 311 void os::Bsd::ucontext_set_pc(ucontext_t * uc, address pc) {
 312   uc->context_pc = (intptr_t)pc ;
 313 }
 314 
 315 intptr_t* os::Bsd::ucontext_get_sp(const ucontext_t * uc) {
 316   return (intptr_t*)uc->context_sp;
 317 }
 318 
 319 intptr_t* os::Bsd::ucontext_get_fp(const ucontext_t * uc) {
 320   return (intptr_t*)uc->context_fp;
 321 }
 322 
 323 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
 324 // is currently interrupted by SIGPROF.
 325 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
 326 // frames. Currently we don't do that on Bsd, so it's the same as
 327 // os::fetch_frame_from_context().
 328 // This method is also used for stack overflow signal handling.
 329 ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread,
 330   const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
 331 
 332   assert(thread != NULL, "just checking");
 333   assert(ret_sp != NULL, "just checking");
 334   assert(ret_fp != NULL, "just checking");
 335 
 336   return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
 337 }
 338 
 339 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
 340                     intptr_t** ret_sp, intptr_t** ret_fp) {
 341 
 342   ExtendedPC  epc;
 343   const ucontext_t* uc = (const ucontext_t*)ucVoid;
 344 
 345   if (uc != NULL) {
 346     epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc));
 347     if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc);
 348     if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc);
 349   } else {
 350     // construct empty ExtendedPC for return value checking
 351     epc = ExtendedPC(NULL);
 352     if (ret_sp) *ret_sp = (intptr_t *)NULL;
 353     if (ret_fp) *ret_fp = (intptr_t *)NULL;
 354   }
 355 
 356   return epc;
 357 }
 358 
 359 frame os::fetch_frame_from_context(const void* ucVoid) {
 360   intptr_t* sp;
 361   intptr_t* fp;
 362   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
 363   return frame(sp, fp, epc.pc());
 364 }
 365 
 366 frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) {
 367   intptr_t* sp;
 368   intptr_t* fp;
 369   ExtendedPC epc = os::Bsd::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp);
 370   return frame(sp, fp, epc.pc());
 371 }
 372 
 373 bool os::Bsd::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
 374   address pc = (address) os::Bsd::ucontext_get_pc(uc);
 375   if (Interpreter::contains(pc)) {
 376     // interpreter performs stack banging after the fixed frame header has
 377     // been generated while the compilers perform it before. To maintain
 378     // semantic consistency between interpreted and compiled frames, the
 379     // method returns the Java sender of the current frame.
 380     *fr = os::fetch_frame_from_ucontext(thread, uc);
 381     if (!fr->is_first_java_frame()) {
 382       assert(fr->safe_for_sender(thread), "Safety check");
 383       *fr = fr->java_sender();
 384     }
 385   } else {
 386     // more complex code with compiled code
 387     assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
 388     CodeBlob* cb = CodeCache::find_blob(pc);
 389     if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
 390       // Not sure where the pc points to, fallback to default
 391       // stack overflow handling
 392       return false;
 393     } else {
 394       *fr = os::fetch_frame_from_ucontext(thread, uc);
 395       // in compiled code, the stack banging is performed just after the return pc
 396       // has been pushed on the stack
 397       *fr = frame(fr->sp() + 1, fr->fp(), (address)*(fr->sp()));
 398       if (!fr->is_java_frame()) {
 399         assert(fr->safe_for_sender(thread), "Safety check");
 400         *fr = fr->java_sender();
 401       }
 402     }
 403   }
 404   assert(fr->is_java_frame(), "Safety check");
 405   return true;
 406 }
 407 
 408 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get
 409 // turned off by -fomit-frame-pointer,
 410 frame os::get_sender_for_C_frame(frame* fr) {
 411   return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
 412 }
 413 
 414 intptr_t* _get_previous_fp() {
 415 #if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__)
 416   register intptr_t **ebp;
 417   __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp));
 418 #else
 419   register intptr_t **ebp __asm__ (SPELL_REG_FP);
 420 #endif
 421   return (intptr_t*) *ebp;   // we want what it points to.
 422 }
 423 
 424 
 425 frame os::current_frame() {
 426   intptr_t* fp = _get_previous_fp();
 427   frame myframe((intptr_t*)os::current_stack_pointer(),
 428                 (intptr_t*)fp,
 429                 CAST_FROM_FN_PTR(address, os::current_frame));
 430   if (os::is_first_C_frame(&myframe)) {
 431     // stack is not walkable
 432     return frame();
 433   } else {
 434     return os::get_sender_for_C_frame(&myframe);
 435   }
 436 }
 437 
 438 // Utility functions
 439 
 440 // From IA32 System Programming Guide
 441 enum {
 442   trap_page_fault = 0xE
 443 };
 444 
 445 extern "C" JNIEXPORT int
 446 JVM_handle_bsd_signal(int sig,
 447                         siginfo_t* info,
 448                         void* ucVoid,
 449                         int abort_if_unrecognized) {
 450   ucontext_t* uc = (ucontext_t*) ucVoid;
 451 
 452   Thread* t = Thread::current_or_null_safe();
 453 
 454   // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
 455   // (no destructors can be run)
 456   os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
 457 
 458   SignalHandlerMark shm(t);
 459 
 460   // Note: it's not uncommon that JNI code uses signal/sigset to install
 461   // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
 462   // or have a SIGILL handler when detecting CPU type). When that happens,
 463   // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To
 464   // avoid unnecessary crash when libjsig is not preloaded, try handle signals
 465   // that do not require siginfo/ucontext first.
 466 
 467   if (sig == SIGPIPE || sig == SIGXFSZ) {
 468     // allow chained handler to go first
 469     if (os::Bsd::chained_handler(sig, info, ucVoid)) {
 470       return true;
 471     } else {
 472       // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
 473       return true;
 474     }
 475   }
 476 
 477   JavaThread* thread = NULL;
 478   VMThread* vmthread = NULL;
 479   if (os::Bsd::signal_handlers_are_installed) {
 480     if (t != NULL ){
 481       if(t->is_Java_thread()) {
 482         thread = (JavaThread*)t;
 483       }
 484       else if(t->is_VM_thread()){
 485         vmthread = (VMThread *)t;
 486       }
 487     }
 488   }
 489 /*
 490   NOTE: does not seem to work on bsd.
 491   if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
 492     // can't decode this kind of signal
 493     info = NULL;
 494   } else {
 495     assert(sig == info->si_signo, "bad siginfo");
 496   }
 497 */
 498   // decide if this trap can be handled by a stub
 499   address stub = NULL;
 500 
 501   address pc          = NULL;
 502 
 503   //%note os_trap_1
 504   if (info != NULL && uc != NULL && thread != NULL) {
 505     pc = (address) os::Bsd::ucontext_get_pc(uc);
 506 
 507     if (StubRoutines::is_safefetch_fault(pc)) {
 508       os::Bsd::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
 509       return 1;
 510     }
 511 
 512     // Handle ALL stack overflow variations here
 513     if (sig == SIGSEGV || sig == SIGBUS) {
 514       address addr = (address) info->si_addr;
 515 
 516       // check if fault address is within thread stack
 517       if (thread->on_local_stack(addr)) {
 518         // stack overflow
 519         if (thread->in_stack_yellow_reserved_zone(addr)) {
 520           if (thread->thread_state() == _thread_in_Java) {
 521             if (thread->in_stack_reserved_zone(addr)) {
 522               frame fr;
 523               if (os::Bsd::get_frame_at_stack_banging_point(thread, uc, &fr)) {
 524                 assert(fr.is_java_frame(), "Must be a Java frame");
 525                 frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
 526                 if (activation.sp() != NULL) {
 527                   thread->disable_stack_reserved_zone();
 528                   if (activation.is_interpreted_frame()) {
 529                     thread->set_reserved_stack_activation((address)(
 530                       activation.fp() + frame::interpreter_frame_initial_sp_offset));
 531                   } else {
 532                     thread->set_reserved_stack_activation((address)activation.unextended_sp());
 533                   }
 534                   return 1;
 535                 }
 536               }
 537             }
 538             // Throw a stack overflow exception.  Guard pages will be reenabled
 539             // while unwinding the stack.
 540             thread->disable_stack_yellow_reserved_zone();
 541             stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
 542           } else {
 543             // Thread was in the vm or native code.  Return and try to finish.
 544             thread->disable_stack_yellow_reserved_zone();
 545             return 1;
 546           }
 547         } else if (thread->in_stack_red_zone(addr)) {
 548           // Fatal red zone violation.  Disable the guard pages and fall through
 549           // to handle_unexpected_exception way down below.
 550           thread->disable_stack_red_zone();
 551           tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
 552         }
 553       }
 554     }
 555 
 556     if ((sig == SIGSEGV || sig == SIGBUS) && VM_Version::is_cpuinfo_segv_addr(pc)) {
 557       // Verify that OS save/restore AVX registers.
 558       stub = VM_Version::cpuinfo_cont_addr();
 559     }
 560 
 561     // We test if stub is already set (by the stack overflow code
 562     // above) so it is not overwritten by the code that follows. This
 563     // check is not required on other platforms, because on other
 564     // platforms we check for SIGSEGV only or SIGBUS only, where here
 565     // we have to check for both SIGSEGV and SIGBUS.
 566     if (thread->thread_state() == _thread_in_Java && stub == NULL) {
 567       // Java thread running in Java code => find exception handler if any
 568       // a fault inside compiled code, the interpreter, or a stub
 569 
 570       if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) {
 571         stub = SharedRuntime::get_poll_stub(pc);
 572 #if defined(__APPLE__)
 573       // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions.
 574       // 64-bit Darwin may also use a SIGBUS (seen with compressed oops).
 575       // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from
 576       // being called, so only do so if the implicit NULL check is not necessary.
 577       } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
 578 #else
 579       } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
 580 #endif
 581         // BugId 4454115: A read from a MappedByteBuffer can fault
 582         // here if the underlying file has been truncated.
 583         // Do not crash the VM in such a case.
 584         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
 585         CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
 586         if (nm != NULL && nm->has_unsafe_access()) {
 587           address next_pc = Assembler::locate_next_instruction(pc);
 588           stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
 589         }
 590       }
 591       else
 592 
 593 #ifdef AMD64
 594       if (sig == SIGFPE  &&
 595           (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
 596         stub =
 597           SharedRuntime::
 598           continuation_for_implicit_exception(thread,
 599                                               pc,
 600                                               SharedRuntime::
 601                                               IMPLICIT_DIVIDE_BY_ZERO);
 602 #ifdef __APPLE__
 603       } else if (sig == SIGFPE && info->si_code == FPE_NOOP) {
 604         int op = pc[0];
 605 
 606         // Skip REX
 607         if ((pc[0] & 0xf0) == 0x40) {
 608           op = pc[1];
 609         } else {
 610           op = pc[0];
 611         }
 612 
 613         // Check for IDIV
 614         if (op == 0xF7) {
 615           stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO);
 616         } else {
 617           // TODO: handle more cases if we are using other x86 instructions
 618           //   that can generate SIGFPE signal.
 619           tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
 620           fatal("please update this code.");
 621         }
 622 #endif /* __APPLE__ */
 623 
 624 #else
 625       if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) {
 626         // HACK: si_code does not work on bsd 2.2.12-20!!!
 627         int op = pc[0];
 628         if (op == 0xDB) {
 629           // FIST
 630           // TODO: The encoding of D2I in i486.ad can cause an exception
 631           // prior to the fist instruction if there was an invalid operation
 632           // pending. We want to dismiss that exception. From the win_32
 633           // side it also seems that if it really was the fist causing
 634           // the exception that we do the d2i by hand with different
 635           // rounding. Seems kind of weird.
 636           // NOTE: that we take the exception at the NEXT floating point instruction.
 637           assert(pc[0] == 0xDB, "not a FIST opcode");
 638           assert(pc[1] == 0x14, "not a FIST opcode");
 639           assert(pc[2] == 0x24, "not a FIST opcode");
 640           return true;
 641         } else if (op == 0xF7) {
 642           // IDIV
 643           stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
 644         } else {
 645           // TODO: handle more cases if we are using other x86 instructions
 646           //   that can generate SIGFPE signal on bsd.
 647           tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
 648           fatal("please update this code.");
 649         }
 650 #endif // AMD64
 651       } else if ((sig == SIGSEGV || sig == SIGBUS) &&
 652                !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
 653           // Determination of interpreter/vtable stub/compiled code null exception
 654           stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
 655       }
 656     } else if (thread->thread_state() == _thread_in_vm &&
 657                sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
 658                thread->doing_unsafe_access()) {
 659         address next_pc = Assembler::locate_next_instruction(pc);
 660         stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
 661     }
 662 
 663     // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
 664     // and the heap gets shrunk before the field access.
 665     if ((sig == SIGSEGV) || (sig == SIGBUS)) {
 666       address addr = JNI_FastGetField::find_slowcase_pc(pc);
 667       if (addr != (address)-1) {
 668         stub = addr;
 669       }
 670     }
 671 
 672     // Check to see if we caught the safepoint code in the
 673     // process of write protecting the memory serialization page.
 674     // It write enables the page immediately after protecting it
 675     // so we can just return to retry the write.
 676     if ((sig == SIGSEGV || sig == SIGBUS) &&
 677         os::is_memory_serialize_page(thread, (address) info->si_addr)) {
 678       // Block current thread until the memory serialize page permission restored.
 679       os::block_on_serialize_page_trap();
 680       return true;
 681     }
 682   }
 683 
 684 #ifndef AMD64
 685   // Execution protection violation
 686   //
 687   // This should be kept as the last step in the triage.  We don't
 688   // have a dedicated trap number for a no-execute fault, so be
 689   // conservative and allow other handlers the first shot.
 690   //
 691   // Note: We don't test that info->si_code == SEGV_ACCERR here.
 692   // this si_code is so generic that it is almost meaningless; and
 693   // the si_code for this condition may change in the future.
 694   // Furthermore, a false-positive should be harmless.
 695   if (UnguardOnExecutionViolation > 0 &&
 696       (sig == SIGSEGV || sig == SIGBUS) &&
 697       uc->context_trapno == trap_page_fault) {
 698     int page_size = os::vm_page_size();
 699     address addr = (address) info->si_addr;
 700     address pc = os::Bsd::ucontext_get_pc(uc);
 701     // Make sure the pc and the faulting address are sane.
 702     //
 703     // If an instruction spans a page boundary, and the page containing
 704     // the beginning of the instruction is executable but the following
 705     // page is not, the pc and the faulting address might be slightly
 706     // different - we still want to unguard the 2nd page in this case.
 707     //
 708     // 15 bytes seems to be a (very) safe value for max instruction size.
 709     bool pc_is_near_addr =
 710       (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
 711     bool instr_spans_page_boundary =
 712       (align_size_down((intptr_t) pc ^ (intptr_t) addr,
 713                        (intptr_t) page_size) > 0);
 714 
 715     if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
 716       static volatile address last_addr =
 717         (address) os::non_memory_address_word();
 718 
 719       // In conservative mode, don't unguard unless the address is in the VM
 720       if (addr != last_addr &&
 721           (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
 722 
 723         // Set memory to RWX and retry
 724         address page_start =
 725           (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
 726         bool res = os::protect_memory((char*) page_start, page_size,
 727                                       os::MEM_PROT_RWX);
 728 
 729         log_debug(os)("Execution protection violation "
 730                       "at " INTPTR_FORMAT
 731                       ", unguarding " INTPTR_FORMAT ": %s, errno=%d", p2i(addr),
 732                       p2i(page_start), (res ? "success" : "failed"), errno);
 733         stub = pc;
 734 
 735         // Set last_addr so if we fault again at the same address, we don't end
 736         // up in an endless loop.
 737         //
 738         // There are two potential complications here.  Two threads trapping at
 739         // the same address at the same time could cause one of the threads to
 740         // think it already unguarded, and abort the VM.  Likely very rare.
 741         //
 742         // The other race involves two threads alternately trapping at
 743         // different addresses and failing to unguard the page, resulting in
 744         // an endless loop.  This condition is probably even more unlikely than
 745         // the first.
 746         //
 747         // Although both cases could be avoided by using locks or thread local
 748         // last_addr, these solutions are unnecessary complication: this
 749         // handler is a best-effort safety net, not a complete solution.  It is
 750         // disabled by default and should only be used as a workaround in case
 751         // we missed any no-execute-unsafe VM code.
 752 
 753         last_addr = addr;
 754       }
 755     }
 756   }
 757 #endif // !AMD64
 758 
 759   if (stub != NULL) {
 760     // save all thread context in case we need to restore it
 761     if (thread != NULL) thread->set_saved_exception_pc(pc);
 762 
 763     os::Bsd::ucontext_set_pc(uc, stub);
 764     return true;
 765   }
 766 
 767   // signal-chaining
 768   if (os::Bsd::chained_handler(sig, info, ucVoid)) {
 769      return true;
 770   }
 771 
 772   if (!abort_if_unrecognized) {
 773     // caller wants another chance, so give it to him
 774     return false;
 775   }
 776 
 777   if (pc == NULL && uc != NULL) {
 778     pc = os::Bsd::ucontext_get_pc(uc);
 779   }
 780 
 781   // unmask current signal
 782   sigset_t newset;
 783   sigemptyset(&newset);
 784   sigaddset(&newset, sig);
 785   sigprocmask(SIG_UNBLOCK, &newset, NULL);
 786 
 787   VMError::report_and_die(t, sig, pc, info, ucVoid);
 788 
 789   ShouldNotReachHere();
 790   return false;
 791 }
 792 
 793 // From solaris_i486.s ported to bsd_i486.s
 794 extern "C" void fixcw();
 795 
 796 void os::Bsd::init_thread_fpu_state(void) {
 797 #ifndef AMD64
 798   // Set fpu to 53 bit precision. This happens too early to use a stub.
 799   fixcw();
 800 #endif // !AMD64
 801 }
 802 
 803 
 804 // Check that the bsd kernel version is 2.4 or higher since earlier
 805 // versions do not support SSE without patches.
 806 bool os::supports_sse() {
 807   return true;
 808 }
 809 
 810 bool os::is_allocatable(size_t bytes) {
 811 #ifdef AMD64
 812   // unused on amd64?
 813   return true;
 814 #else
 815 
 816   if (bytes < 2 * G) {
 817     return true;
 818   }
 819 
 820   char* addr = reserve_memory(bytes, NULL);
 821 
 822   if (addr != NULL) {
 823     release_memory(addr, bytes);
 824   }
 825 
 826   return addr != NULL;
 827 #endif // AMD64
 828 }
 829 
 830 ////////////////////////////////////////////////////////////////////////////////
 831 // thread stack
 832 
 833 #ifdef AMD64
 834 size_t os::Bsd::min_stack_allowed  = 64 * K;
 835 #else
 836 size_t os::Bsd::min_stack_allowed  =  (48 DEBUG_ONLY(+4))*K;
 837 
 838 #ifdef __GNUC__
 839 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;})
 840 #endif
 841 
 842 #endif // AMD64
 843 
 844 // return default stack size for thr_type
 845 size_t os::Bsd::default_stack_size(os::ThreadType thr_type) {
 846   // default stack size (compiler thread needs larger stack)
 847 #ifdef AMD64
 848   size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
 849 #else
 850   size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
 851 #endif // AMD64
 852   return s;
 853 }
 854 
 855 size_t os::Bsd::default_guard_size(os::ThreadType thr_type) {
 856   // Creating guard page is very expensive. Java thread has HotSpot
 857   // guard page, only enable glibc guard page for non-Java threads.
 858   return (thr_type == java_thread ? 0 : page_size());
 859 }
 860 
 861 // Java thread:
 862 //
 863 //   Low memory addresses
 864 //    +------------------------+
 865 //    |                        |\  JavaThread created by VM does not have glibc
 866 //    |    glibc guard page    | - guard, attached Java thread usually has
 867 //    |                        |/  1 page glibc guard.
 868 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
 869 //    |                        |\
 870 //    |  HotSpot Guard Pages   | - red and yellow pages
 871 //    |                        |/
 872 //    +------------------------+ JavaThread::stack_yellow_zone_base()
 873 //    |                        |\
 874 //    |      Normal Stack      | -
 875 //    |                        |/
 876 // P2 +------------------------+ Thread::stack_base()
 877 //
 878 // Non-Java thread:
 879 //
 880 //   Low memory addresses
 881 //    +------------------------+
 882 //    |                        |\
 883 //    |  glibc guard page      | - usually 1 page
 884 //    |                        |/
 885 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
 886 //    |                        |\
 887 //    |      Normal Stack      | -
 888 //    |                        |/
 889 // P2 +------------------------+ Thread::stack_base()
 890 //
 891 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
 892 //    pthread_attr_getstack()
 893 
 894 static void current_stack_region(address * bottom, size_t * size) {
 895 #ifdef __APPLE__
 896   pthread_t self = pthread_self();
 897   void *stacktop = pthread_get_stackaddr_np(self);
 898   *size = pthread_get_stacksize_np(self);
 899   // workaround for OS X 10.9.0 (Mavericks)
 900   // pthread_get_stacksize_np returns 128 pages even though the actual size is 2048 pages
 901   if (pthread_main_np() == 1) {
 902     if ((*size) < (DEFAULT_MAIN_THREAD_STACK_PAGES * (size_t)getpagesize())) {
 903       char kern_osrelease[256];
 904       size_t kern_osrelease_size = sizeof(kern_osrelease);
 905       int ret = sysctlbyname("kern.osrelease", kern_osrelease, &kern_osrelease_size, NULL, 0);
 906       if (ret == 0) {
 907         // get the major number, atoi will ignore the minor amd micro portions of the version string
 908         if (atoi(kern_osrelease) >= OS_X_10_9_0_KERNEL_MAJOR_VERSION) {
 909           *size = (DEFAULT_MAIN_THREAD_STACK_PAGES*getpagesize());
 910         }
 911       }
 912     }
 913   }
 914   *bottom = (address) stacktop - *size;
 915 #elif defined(__OpenBSD__)
 916   stack_t ss;
 917   int rslt = pthread_stackseg_np(pthread_self(), &ss);
 918 
 919   if (rslt != 0)
 920     fatal("pthread_stackseg_np failed with err = %d", rslt);
 921 
 922   *bottom = (address)((char *)ss.ss_sp - ss.ss_size);
 923   *size   = ss.ss_size;
 924 #else
 925   pthread_attr_t attr;
 926 
 927   int rslt = pthread_attr_init(&attr);
 928 
 929   // JVM needs to know exact stack location, abort if it fails
 930   if (rslt != 0)
 931     fatal("pthread_attr_init failed with err = %d", rslt);
 932 
 933   rslt = pthread_attr_get_np(pthread_self(), &attr);
 934 
 935   if (rslt != 0)
 936     fatal("pthread_attr_get_np failed with err = %d", rslt);
 937 
 938   if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 ||
 939     pthread_attr_getstacksize(&attr, size) != 0) {
 940     fatal("Can not locate current stack attributes!");
 941   }
 942 
 943   pthread_attr_destroy(&attr);
 944 #endif
 945   assert(os::current_stack_pointer() >= *bottom &&
 946          os::current_stack_pointer() < *bottom + *size, "just checking");
 947 }
 948 
 949 address os::current_stack_base() {
 950   address bottom;
 951   size_t size;
 952   current_stack_region(&bottom, &size);
 953   return (bottom + size);
 954 }
 955 
 956 size_t os::current_stack_size() {
 957   // stack size includes normal stack and HotSpot guard pages
 958   address bottom;
 959   size_t size;
 960   current_stack_region(&bottom, &size);
 961   return size;
 962 }
 963 
 964 /////////////////////////////////////////////////////////////////////////////
 965 // helper functions for fatal error handler
 966 
 967 void os::print_context(outputStream *st, const void *context) {
 968   if (context == NULL) return;
 969 
 970   const ucontext_t *uc = (const ucontext_t*)context;
 971   st->print_cr("Registers:");
 972 #ifdef AMD64
 973   st->print(  "RAX=" INTPTR_FORMAT, uc->context_rax);
 974   st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx);
 975   st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx);
 976   st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx);
 977   st->cr();
 978   st->print(  "RSP=" INTPTR_FORMAT, uc->context_rsp);
 979   st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp);
 980   st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi);
 981   st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi);
 982   st->cr();
 983   st->print(  "R8 =" INTPTR_FORMAT, uc->context_r8);
 984   st->print(", R9 =" INTPTR_FORMAT, uc->context_r9);
 985   st->print(", R10=" INTPTR_FORMAT, uc->context_r10);
 986   st->print(", R11=" INTPTR_FORMAT, uc->context_r11);
 987   st->cr();
 988   st->print(  "R12=" INTPTR_FORMAT, uc->context_r12);
 989   st->print(", R13=" INTPTR_FORMAT, uc->context_r13);
 990   st->print(", R14=" INTPTR_FORMAT, uc->context_r14);
 991   st->print(", R15=" INTPTR_FORMAT, uc->context_r15);
 992   st->cr();
 993   st->print(  "RIP=" INTPTR_FORMAT, uc->context_rip);
 994   st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags);
 995   st->print(", ERR=" INTPTR_FORMAT, uc->context_err);
 996   st->cr();
 997   st->print("  TRAPNO=" INTPTR_FORMAT, uc->context_trapno);
 998 #else
 999   st->print(  "EAX=" INTPTR_FORMAT, uc->context_eax);
1000   st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx);
1001   st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx);
1002   st->print(", EDX=" INTPTR_FORMAT, uc->context_edx);
1003   st->cr();
1004   st->print(  "ESP=" INTPTR_FORMAT, uc->context_esp);
1005   st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp);
1006   st->print(", ESI=" INTPTR_FORMAT, uc->context_esi);
1007   st->print(", EDI=" INTPTR_FORMAT, uc->context_edi);
1008   st->cr();
1009   st->print(  "EIP=" INTPTR_FORMAT, uc->context_eip);
1010   st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags);
1011 #endif // AMD64
1012   st->cr();
1013   st->cr();
1014 
1015   intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc);
1016   st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
1017   print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
1018   st->cr();
1019 
1020   // Note: it may be unsafe to inspect memory near pc. For example, pc may
1021   // point to garbage if entry point in an nmethod is corrupted. Leave
1022   // this at the end, and hope for the best.
1023   address pc = os::Bsd::ucontext_get_pc(uc);
1024   st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
1025   print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
1026 }
1027 
1028 void os::print_register_info(outputStream *st, const void *context) {
1029   if (context == NULL) return;
1030 
1031   const ucontext_t *uc = (const ucontext_t*)context;
1032 
1033   st->print_cr("Register to memory mapping:");
1034   st->cr();
1035 
1036   // this is horrendously verbose but the layout of the registers in the
1037   // context does not match how we defined our abstract Register set, so
1038   // we can't just iterate through the gregs area
1039 
1040   // this is only for the "general purpose" registers
1041 
1042 #ifdef AMD64
1043   st->print("RAX="); print_location(st, uc->context_rax);
1044   st->print("RBX="); print_location(st, uc->context_rbx);
1045   st->print("RCX="); print_location(st, uc->context_rcx);
1046   st->print("RDX="); print_location(st, uc->context_rdx);
1047   st->print("RSP="); print_location(st, uc->context_rsp);
1048   st->print("RBP="); print_location(st, uc->context_rbp);
1049   st->print("RSI="); print_location(st, uc->context_rsi);
1050   st->print("RDI="); print_location(st, uc->context_rdi);
1051   st->print("R8 ="); print_location(st, uc->context_r8);
1052   st->print("R9 ="); print_location(st, uc->context_r9);
1053   st->print("R10="); print_location(st, uc->context_r10);
1054   st->print("R11="); print_location(st, uc->context_r11);
1055   st->print("R12="); print_location(st, uc->context_r12);
1056   st->print("R13="); print_location(st, uc->context_r13);
1057   st->print("R14="); print_location(st, uc->context_r14);
1058   st->print("R15="); print_location(st, uc->context_r15);
1059 #else
1060   st->print("EAX="); print_location(st, uc->context_eax);
1061   st->print("EBX="); print_location(st, uc->context_ebx);
1062   st->print("ECX="); print_location(st, uc->context_ecx);
1063   st->print("EDX="); print_location(st, uc->context_edx);
1064   st->print("ESP="); print_location(st, uc->context_esp);
1065   st->print("EBP="); print_location(st, uc->context_ebp);
1066   st->print("ESI="); print_location(st, uc->context_esi);
1067   st->print("EDI="); print_location(st, uc->context_edi);
1068 #endif // AMD64
1069 
1070   st->cr();
1071 }
1072 
1073 void os::setup_fpu() {
1074 #ifndef AMD64
1075   address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
1076   __asm__ volatile (  "fldcw (%0)" :
1077                       : "r" (fpu_cntrl) : "memory");
1078 #endif // !AMD64
1079 }
1080 
1081 #ifndef PRODUCT
1082 void os::verify_stack_alignment() {
1083 }
1084 #endif
1085 
1086 int os::extra_bang_size_in_bytes() {
1087   // JDK-8050147 requires the full cache line bang for x86.
1088   return VM_Version::L1_line_size();
1089 }