1 /*
  2  * Copyright (c) 1999, 2020, 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 "jvm.h"
 27 #include "asm/macroAssembler.hpp"
 28 #include "classfile/classLoader.hpp"
 29 #include "classfile/systemDictionary.hpp"
 30 #include "classfile/vmSymbols.hpp"
 31 #include "code/icBuffer.hpp"
 32 #include "code/vtableStubs.hpp"
 33 #include "interpreter/interpreter.hpp"
 34 #include "memory/allocation.inline.hpp"
 35 #include "memory/resourceArea.hpp"
 36 #include "nativeInst_x86.hpp"
 37 #include "os_share_windows.hpp"
 38 #include "prims/jniFastGetField.hpp"
 39 #include "prims/jvm_misc.hpp"
 40 #include "runtime/arguments.hpp"
 41 #include "runtime/frame.inline.hpp"
 42 #include "runtime/interfaceSupport.inline.hpp"
 43 #include "runtime/java.hpp"
 44 #include "runtime/javaCalls.hpp"
 45 #include "runtime/mutexLocker.hpp"
 46 #include "runtime/osThread.hpp"
 47 #include "runtime/sharedRuntime.hpp"
 48 #include "runtime/stubRoutines.hpp"
 49 #include "runtime/thread.inline.hpp"
 50 #include "runtime/timer.hpp"
 51 #include "symbolengine.hpp"
 52 #include "unwind_windows_x86.hpp"
 53 #include "utilities/events.hpp"
 54 #include "utilities/vmError.hpp"
 55 #include "windbghelp.hpp"
 56 
 57 
 58 #undef REG_SP
 59 #undef REG_FP
 60 #undef REG_PC
 61 #ifdef AMD64
 62 #define REG_SP Rsp
 63 #define REG_FP Rbp
 64 #define REG_PC Rip
 65 #else
 66 #define REG_SP Esp
 67 #define REG_FP Ebp
 68 #define REG_PC Eip
 69 #endif // AMD64
 70 
 71 extern LONG WINAPI topLevelExceptionFilter(_EXCEPTION_POINTERS* );
 72 
 73 // Install a win32 structured exception handler around thread.
 74 void os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread) {
 75   __try {
 76 
 77 #ifndef AMD64
 78     // We store the current thread in this wrapperthread location
 79     // and determine how far away this address is from the structured
 80     // execption pointer that FS:[0] points to.  This get_thread
 81     // code can then get the thread pointer via FS.
 82     //
 83     // Warning:  This routine must NEVER be inlined since we'd end up with
 84     //           multiple offsets.
 85     //
 86     volatile Thread* wrapperthread = thread;
 87 
 88     if (os::win32::get_thread_ptr_offset() == 0) {
 89       int thread_ptr_offset;
 90       __asm {
 91         lea eax, dword ptr wrapperthread;
 92         sub eax, dword ptr FS:[0H];
 93         mov thread_ptr_offset, eax
 94       };
 95       os::win32::set_thread_ptr_offset(thread_ptr_offset);
 96     }
 97 #ifdef ASSERT
 98     // Verify that the offset hasn't changed since we initally captured
 99     // it. This might happen if we accidentally ended up with an
100     // inlined version of this routine.
101     else {
102       int test_thread_ptr_offset;
103       __asm {
104         lea eax, dword ptr wrapperthread;
105         sub eax, dword ptr FS:[0H];
106         mov test_thread_ptr_offset, eax
107       };
108       assert(test_thread_ptr_offset == os::win32::get_thread_ptr_offset(),
109              "thread pointer offset from SEH changed");
110     }
111 #endif // ASSERT
112 #endif // !AMD64
113 
114     f(value, method, args, thread);
115   } __except(topLevelExceptionFilter((_EXCEPTION_POINTERS*)_exception_info())) {
116       // Nothing to do.
117   }
118 }
119 
120 #ifdef AMD64
121 
122 // This is the language specific handler for exceptions
123 // originating from dynamically generated code.
124 // We call the standard structured exception handler
125 // We only expect Continued Execution since we cannot unwind
126 // from generated code.
127 LONG HandleExceptionFromCodeCache(
128   IN PEXCEPTION_RECORD ExceptionRecord,
129   IN ULONG64 EstablisherFrame,
130   IN OUT PCONTEXT ContextRecord,
131   IN OUT PDISPATCHER_CONTEXT DispatcherContext) {
132   EXCEPTION_POINTERS ep;
133   LONG result;
134 
135   ep.ExceptionRecord = ExceptionRecord;
136   ep.ContextRecord = ContextRecord;
137 
138   result = topLevelExceptionFilter(&ep);
139 
140   // We better only get a CONTINUE_EXECUTION from our handler
141   // since we don't have unwind information registered.
142 
143   guarantee( result == EXCEPTION_CONTINUE_EXECUTION,
144              "Unexpected result from topLevelExceptionFilter");
145 
146   return(ExceptionContinueExecution);
147 }
148 
149 
150 // Structure containing the Windows Data Structures required
151 // to register our Code Cache exception handler.
152 // We put these in the CodeCache since the API requires
153 // all addresses in these structures are relative to the Code
154 // area registered with RtlAddFunctionTable.
155 typedef struct {
156   char ExceptionHandlerInstr[16];  // jmp HandleExceptionFromCodeCache
157   RUNTIME_FUNCTION rt;
158   UNWIND_INFO_EH_ONLY unw;
159 } DynamicCodeData, *pDynamicCodeData;
160 
161 #endif // AMD64
162 //
163 // Register our CodeCache area with the OS so it will dispatch exceptions
164 // to our topLevelExceptionFilter when we take an exception in our
165 // dynamically generated code.
166 //
167 // Arguments:  low and high are the address of the full reserved
168 // codeCache area
169 //
170 bool os::register_code_area(char *low, char *high) {
171 #ifdef AMD64
172 
173   ResourceMark rm;
174 
175   pDynamicCodeData pDCD;
176   PRUNTIME_FUNCTION prt;
177   PUNWIND_INFO_EH_ONLY punwind;
178 
179   BufferBlob* blob = BufferBlob::create("CodeCache Exception Handler", sizeof(DynamicCodeData));
180   CodeBuffer cb(blob);
181   MacroAssembler* masm = new MacroAssembler(&cb);
182   pDCD = (pDynamicCodeData) masm->pc();
183 
184   masm->jump(ExternalAddress((address)&HandleExceptionFromCodeCache));
185   masm->flush();
186 
187   // Create an Unwind Structure specifying no unwind info
188   // other than an Exception Handler
189   punwind = &pDCD->unw;
190   punwind->Version = 1;
191   punwind->Flags = UNW_FLAG_EHANDLER;
192   punwind->SizeOfProlog = 0;
193   punwind->CountOfCodes = 0;
194   punwind->FrameRegister = 0;
195   punwind->FrameOffset = 0;
196   punwind->ExceptionHandler = (char *)(&(pDCD->ExceptionHandlerInstr[0])) -
197                               (char*)low;
198   punwind->ExceptionData[0] = 0;
199 
200   // This structure describes the covered dynamic code area.
201   // Addresses are relative to the beginning on the code cache area
202   prt = &pDCD->rt;
203   prt->BeginAddress = 0;
204   prt->EndAddress = (ULONG)(high - low);
205   prt->UnwindData = ((char *)punwind - low);
206 
207   guarantee(RtlAddFunctionTable(prt, 1, (ULONGLONG)low),
208             "Failed to register Dynamic Code Exception Handler with RtlAddFunctionTable");
209 
210 #endif // AMD64
211   return true;
212 }
213 
214 // Atomics and Stub Functions
215 
216 typedef int32_t   xchg_func_t            (int32_t,  volatile int32_t*);
217 typedef int64_t   xchg_long_func_t       (int64_t,  volatile int64_t*);
218 typedef int32_t   cmpxchg_func_t         (int32_t,  volatile int32_t*, int32_t);
219 typedef int8_t    cmpxchg_byte_func_t    (int8_t,   volatile int8_t*,  int8_t);
220 typedef int64_t   cmpxchg_long_func_t    (int64_t,  volatile int64_t*, int64_t);
221 typedef int32_t   add_func_t             (int32_t,  volatile int32_t*);
222 typedef int64_t   add_long_func_t        (int64_t,  volatile int64_t*);
223 
224 #ifdef AMD64
225 
226 int32_t os::atomic_xchg_bootstrap(int32_t exchange_value, volatile int32_t* dest) {
227   // try to use the stub:
228   xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry());
229 
230   if (func != NULL) {
231     os::atomic_xchg_func = func;
232     return (*func)(exchange_value, dest);
233   }
234   assert(Threads::number_of_threads() == 0, "for bootstrap only");
235 
236   int32_t old_value = *dest;
237   *dest = exchange_value;
238   return old_value;
239 }
240 
241 int64_t os::atomic_xchg_long_bootstrap(int64_t exchange_value, volatile int64_t* dest) {
242   // try to use the stub:
243   xchg_long_func_t* func = CAST_TO_FN_PTR(xchg_long_func_t*, StubRoutines::atomic_xchg_long_entry());
244 
245   if (func != NULL) {
246     os::atomic_xchg_long_func = func;
247     return (*func)(exchange_value, dest);
248   }
249   assert(Threads::number_of_threads() == 0, "for bootstrap only");
250 
251   int64_t old_value = *dest;
252   *dest = exchange_value;
253   return old_value;
254 }
255 
256 
257 int32_t os::atomic_cmpxchg_bootstrap(int32_t exchange_value, volatile int32_t* dest, int32_t compare_value) {
258   // try to use the stub:
259   cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());
260 
261   if (func != NULL) {
262     os::atomic_cmpxchg_func = func;
263     return (*func)(exchange_value, dest, compare_value);
264   }
265   assert(Threads::number_of_threads() == 0, "for bootstrap only");
266 
267   int32_t old_value = *dest;
268   if (old_value == compare_value)
269     *dest = exchange_value;
270   return old_value;
271 }
272 
273 int8_t os::atomic_cmpxchg_byte_bootstrap(int8_t exchange_value, volatile int8_t* dest, int8_t compare_value) {
274   // try to use the stub:
275   cmpxchg_byte_func_t* func = CAST_TO_FN_PTR(cmpxchg_byte_func_t*, StubRoutines::atomic_cmpxchg_byte_entry());
276 
277   if (func != NULL) {
278     os::atomic_cmpxchg_byte_func = func;
279     return (*func)(exchange_value, dest, compare_value);
280   }
281   assert(Threads::number_of_threads() == 0, "for bootstrap only");
282 
283   int8_t old_value = *dest;
284   if (old_value == compare_value)
285     *dest = exchange_value;
286   return old_value;
287 }
288 
289 #endif // AMD64
290 
291 int64_t os::atomic_cmpxchg_long_bootstrap(int64_t exchange_value, volatile int64_t* dest, int64_t compare_value) {
292   // try to use the stub:
293   cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());
294 
295   if (func != NULL) {
296     os::atomic_cmpxchg_long_func = func;
297     return (*func)(exchange_value, dest, compare_value);
298   }
299   assert(Threads::number_of_threads() == 0, "for bootstrap only");
300 
301   int64_t old_value = *dest;
302   if (old_value == compare_value)
303     *dest = exchange_value;
304   return old_value;
305 }
306 
307 #ifdef AMD64
308 
309 int32_t os::atomic_add_bootstrap(int32_t add_value, volatile int32_t* dest) {
310   // try to use the stub:
311   add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry());
312 
313   if (func != NULL) {
314     os::atomic_add_func = func;
315     return (*func)(add_value, dest);
316   }
317   assert(Threads::number_of_threads() == 0, "for bootstrap only");
318 
319   return (*dest) += add_value;
320 }
321 
322 int64_t os::atomic_add_long_bootstrap(int64_t add_value, volatile int64_t* dest) {
323   // try to use the stub:
324   add_long_func_t* func = CAST_TO_FN_PTR(add_long_func_t*, StubRoutines::atomic_add_long_entry());
325 
326   if (func != NULL) {
327     os::atomic_add_long_func = func;
328     return (*func)(add_value, dest);
329   }
330   assert(Threads::number_of_threads() == 0, "for bootstrap only");
331 
332   return (*dest) += add_value;
333 }
334 
335 xchg_func_t*         os::atomic_xchg_func         = os::atomic_xchg_bootstrap;
336 xchg_long_func_t*    os::atomic_xchg_long_func    = os::atomic_xchg_long_bootstrap;
337 cmpxchg_func_t*      os::atomic_cmpxchg_func      = os::atomic_cmpxchg_bootstrap;
338 cmpxchg_byte_func_t* os::atomic_cmpxchg_byte_func = os::atomic_cmpxchg_byte_bootstrap;
339 add_func_t*          os::atomic_add_func          = os::atomic_add_bootstrap;
340 add_long_func_t*     os::atomic_add_long_func     = os::atomic_add_long_bootstrap;
341 
342 #endif // AMD64
343 
344 cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
345 
346 #ifdef AMD64
347 /*
348  * Windows/x64 does not use stack frames the way expected by Java:
349  * [1] in most cases, there is no frame pointer. All locals are addressed via RSP
350  * [2] in rare cases, when alloca() is used, a frame pointer is used, but this may
351  *     not be RBP.
352  * See http://msdn.microsoft.com/en-us/library/ew5tede7.aspx
353  *
354  * So it's not possible to print the native stack using the
355  *     while (...) {...  fr = os::get_sender_for_C_frame(&fr); }
356  * loop in vmError.cpp. We need to roll our own loop.
357  */
358 bool os::platform_print_native_stack(outputStream* st, const void* context,
359                                      char *buf, int buf_size)
360 {
361   CONTEXT ctx;
362   if (context != NULL) {
363     memcpy(&ctx, context, sizeof(ctx));
364   } else {
365     RtlCaptureContext(&ctx);
366   }
367 
368   st->print_cr("Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)");
369 
370   STACKFRAME stk;
371   memset(&stk, 0, sizeof(stk));
372   stk.AddrStack.Offset    = ctx.Rsp;
373   stk.AddrStack.Mode      = AddrModeFlat;
374   stk.AddrFrame.Offset    = ctx.Rbp;
375   stk.AddrFrame.Mode      = AddrModeFlat;
376   stk.AddrPC.Offset       = ctx.Rip;
377   stk.AddrPC.Mode         = AddrModeFlat;
378 
379   int count = 0;
380   address lastpc = 0;
381   while (count++ < StackPrintLimit) {
382     intptr_t* sp = (intptr_t*)stk.AddrStack.Offset;
383     intptr_t* fp = (intptr_t*)stk.AddrFrame.Offset; // NOT necessarily the same as ctx.Rbp!
384     address pc = (address)stk.AddrPC.Offset;
385 
386     if (pc != NULL) {
387       if (count == 2 && lastpc == pc) {
388         // Skip it -- StackWalk64() may return the same PC
389         // (but different SP) on the first try.
390       } else {
391         // Don't try to create a frame(sp, fp, pc) -- on WinX64, stk.AddrFrame
392         // may not contain what Java expects, and may cause the frame() constructor
393         // to crash. Let's just print out the symbolic address.
394         frame::print_C_frame(st, buf, buf_size, pc);
395         // print source file and line, if available
396         char buf[128];
397         int line_no;
398         if (SymbolEngine::get_source_info(pc, buf, sizeof(buf), &line_no)) {
399           st->print("  (%s:%d)", buf, line_no);
400         }
401         st->cr();
402       }
403       lastpc = pc;
404     }
405 
406     PVOID p = WindowsDbgHelp::symFunctionTableAccess64(GetCurrentProcess(), stk.AddrPC.Offset);
407     if (!p) {
408       // StackWalk64() can't handle this PC. Calling StackWalk64 again may cause crash.
409       break;
410     }
411 
412     BOOL result = WindowsDbgHelp::stackWalk64(
413         IMAGE_FILE_MACHINE_AMD64,  // __in      DWORD MachineType,
414         GetCurrentProcess(),       // __in      HANDLE hProcess,
415         GetCurrentThread(),        // __in      HANDLE hThread,
416         &stk,                      // __inout   LP STACKFRAME64 StackFrame,
417         &ctx);                     // __inout   PVOID ContextRecord,
418 
419     if (!result) {
420       break;
421     }
422   }
423   if (count > StackPrintLimit) {
424     st->print_cr("...<more frames>...");
425   }
426   st->cr();
427 
428   return true;
429 }
430 #endif // AMD64
431 
432 address os::fetch_frame_from_context(const void* ucVoid,
433                     intptr_t** ret_sp, intptr_t** ret_fp) {
434 
435   address  epc;
436   CONTEXT* uc = (CONTEXT*)ucVoid;
437 
438   if (uc != NULL) {
439     epc = (address)uc->REG_PC;
440     if (ret_sp) *ret_sp = (intptr_t*)uc->REG_SP;
441     if (ret_fp) *ret_fp = (intptr_t*)uc->REG_FP;
442   } else {
443     epc = NULL;
444     if (ret_sp) *ret_sp = (intptr_t *)NULL;
445     if (ret_fp) *ret_fp = (intptr_t *)NULL;
446   }
447 
448   return epc;
449 }
450 
451 frame os::fetch_frame_from_context(const void* ucVoid) {
452   intptr_t* sp;
453   intptr_t* fp;
454   address epc = fetch_frame_from_context(ucVoid, &sp, &fp);
455   return frame(sp, fp, epc);
456 }
457 
458 // VC++ does not save frame pointer on stack in optimized build. It
459 // can be turned off by /Oy-. If we really want to walk C frames,
460 // we can use the StackWalk() API.
461 frame os::get_sender_for_C_frame(frame* fr) {
462   return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
463 }
464 
465 #ifndef AMD64
466 // Ignore "C4172: returning address of local variable or temporary" on 32bit
467 PRAGMA_DIAG_PUSH
468 PRAGMA_DISABLE_MSVC_WARNING(4172)
469 // Returns an estimate of the current stack pointer. Result must be guaranteed
470 // to point into the calling threads stack, and be no lower than the current
471 // stack pointer.
472 address os::current_stack_pointer() {
473   int dummy;
474   address sp = (address)&dummy;
475   return sp;
476 }
477 PRAGMA_DIAG_POP
478 #else
479 // Returns the current stack pointer. Accurate value needed for
480 // os::verify_stack_alignment().
481 address os::current_stack_pointer() {
482   typedef address get_sp_func();
483   get_sp_func* func = CAST_TO_FN_PTR(get_sp_func*,
484                                      StubRoutines::x86::get_previous_sp_entry());
485   return (*func)();
486 }
487 #endif
488 
489 
490 #ifndef AMD64
491 intptr_t* _get_previous_fp() {
492   intptr_t **frameptr;
493   __asm {
494     mov frameptr, ebp
495   };
496   // ebp (frameptr) is for this frame (_get_previous_fp). We want the ebp for the
497   // caller of os::current_frame*(), so go up two frames. However, for
498   // optimized builds, _get_previous_fp() will be inlined, so only go
499   // up 1 frame in that case.
500 #ifdef _NMT_NOINLINE_
501   return **(intptr_t***)frameptr;
502 #else
503   return *frameptr;
504 #endif
505 }
506 #endif // !AMD64
507 
508 frame os::current_frame() {
509 
510 #ifdef AMD64
511   // apparently _asm not supported on windows amd64
512   typedef intptr_t*      get_fp_func           ();
513   get_fp_func* func = CAST_TO_FN_PTR(get_fp_func*,
514                                      StubRoutines::x86::get_previous_fp_entry());
515   if (func == NULL) return frame();
516   intptr_t* fp = (*func)();
517   if (fp == NULL) {
518     return frame();
519   }
520 #else
521   intptr_t* fp = _get_previous_fp();
522 #endif // AMD64
523 
524   frame myframe((intptr_t*)os::current_stack_pointer(),
525                 (intptr_t*)fp,
526                 CAST_FROM_FN_PTR(address, os::current_frame));
527   if (os::is_first_C_frame(&myframe)) {
528     // stack is not walkable
529     return frame();
530   } else {
531     return os::get_sender_for_C_frame(&myframe);
532   }
533 }
534 
535 void os::print_context(outputStream *st, const void *context) {
536   if (context == NULL) return;
537 
538   const CONTEXT* uc = (const CONTEXT*)context;
539 
540   st->print_cr("Registers:");
541 #ifdef AMD64
542   st->print(  "RAX=" INTPTR_FORMAT, uc->Rax);
543   st->print(", RBX=" INTPTR_FORMAT, uc->Rbx);
544   st->print(", RCX=" INTPTR_FORMAT, uc->Rcx);
545   st->print(", RDX=" INTPTR_FORMAT, uc->Rdx);
546   st->cr();
547   st->print(  "RSP=" INTPTR_FORMAT, uc->Rsp);
548   st->print(", RBP=" INTPTR_FORMAT, uc->Rbp);
549   st->print(", RSI=" INTPTR_FORMAT, uc->Rsi);
550   st->print(", RDI=" INTPTR_FORMAT, uc->Rdi);
551   st->cr();
552   st->print(  "R8 =" INTPTR_FORMAT, uc->R8);
553   st->print(", R9 =" INTPTR_FORMAT, uc->R9);
554   st->print(", R10=" INTPTR_FORMAT, uc->R10);
555   st->print(", R11=" INTPTR_FORMAT, uc->R11);
556   st->cr();
557   st->print(  "R12=" INTPTR_FORMAT, uc->R12);
558   st->print(", R13=" INTPTR_FORMAT, uc->R13);
559   st->print(", R14=" INTPTR_FORMAT, uc->R14);
560   st->print(", R15=" INTPTR_FORMAT, uc->R15);
561   st->cr();
562   st->print(  "RIP=" INTPTR_FORMAT, uc->Rip);
563   st->print(", EFLAGS=" INTPTR_FORMAT, uc->EFlags);
564 #else
565   st->print(  "EAX=" INTPTR_FORMAT, uc->Eax);
566   st->print(", EBX=" INTPTR_FORMAT, uc->Ebx);
567   st->print(", ECX=" INTPTR_FORMAT, uc->Ecx);
568   st->print(", EDX=" INTPTR_FORMAT, uc->Edx);
569   st->cr();
570   st->print(  "ESP=" INTPTR_FORMAT, uc->Esp);
571   st->print(", EBP=" INTPTR_FORMAT, uc->Ebp);
572   st->print(", ESI=" INTPTR_FORMAT, uc->Esi);
573   st->print(", EDI=" INTPTR_FORMAT, uc->Edi);
574   st->cr();
575   st->print(  "EIP=" INTPTR_FORMAT, uc->Eip);
576   st->print(", EFLAGS=" INTPTR_FORMAT, uc->EFlags);
577 #endif // AMD64
578   st->cr();
579   st->cr();
580 
581   intptr_t *sp = (intptr_t *)uc->REG_SP;
582   st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
583   print_hex_dump(st, (address)sp, (address)(sp + 32), sizeof(intptr_t));
584   st->cr();
585 
586   // Note: it may be unsafe to inspect memory near pc. For example, pc may
587   // point to garbage if entry point in an nmethod is corrupted. Leave
588   // this at the end, and hope for the best.
589   address pc = (address)uc->REG_PC;
590   print_instructions(st, pc, sizeof(char));
591   st->cr();
592 }
593 
594 
595 void os::print_register_info(outputStream *st, const void *context) {
596   if (context == NULL) return;
597 
598   const CONTEXT* uc = (const CONTEXT*)context;
599 
600   st->print_cr("Register to memory mapping:");
601   st->cr();
602 
603   // this is only for the "general purpose" registers
604 
605 #ifdef AMD64
606   st->print("RIP="); print_location(st, uc->Rip);
607   st->print("RAX="); print_location(st, uc->Rax);
608   st->print("RBX="); print_location(st, uc->Rbx);
609   st->print("RCX="); print_location(st, uc->Rcx);
610   st->print("RDX="); print_location(st, uc->Rdx);
611   st->print("RSP="); print_location(st, uc->Rsp);
612   st->print("RBP="); print_location(st, uc->Rbp);
613   st->print("RSI="); print_location(st, uc->Rsi);
614   st->print("RDI="); print_location(st, uc->Rdi);
615   st->print("R8 ="); print_location(st, uc->R8);
616   st->print("R9 ="); print_location(st, uc->R9);
617   st->print("R10="); print_location(st, uc->R10);
618   st->print("R11="); print_location(st, uc->R11);
619   st->print("R12="); print_location(st, uc->R12);
620   st->print("R13="); print_location(st, uc->R13);
621   st->print("R14="); print_location(st, uc->R14);
622   st->print("R15="); print_location(st, uc->R15);
623 #else
624   st->print("EIP="); print_location(st, uc->Eip);
625   st->print("EAX="); print_location(st, uc->Eax);
626   st->print("EBX="); print_location(st, uc->Ebx);
627   st->print("ECX="); print_location(st, uc->Ecx);
628   st->print("EDX="); print_location(st, uc->Edx);
629   st->print("ESP="); print_location(st, uc->Esp);
630   st->print("EBP="); print_location(st, uc->Ebp);
631   st->print("ESI="); print_location(st, uc->Esi);
632   st->print("EDI="); print_location(st, uc->Edi);
633 #endif
634 
635   st->cr();
636 }
637 
638 extern "C" int SpinPause () {
639 #ifdef AMD64
640    return 0 ;
641 #else
642    // pause == rep:nop
643    // On systems that don't support pause a rep:nop
644    // is executed as a nop.  The rep: prefix is ignored.
645    _asm {
646       pause ;
647    };
648    return 1 ;
649 #endif // AMD64
650 }
651 
652 
653 void os::setup_fpu() {
654 #ifndef AMD64
655   int fpu_cntrl_word = StubRoutines::fpu_cntrl_wrd_std();
656   __asm fldcw fpu_cntrl_word;
657 #endif // !AMD64
658 }
659 
660 #ifndef PRODUCT
661 void os::verify_stack_alignment() {
662 #ifdef AMD64
663   // The current_stack_pointer() calls generated get_previous_sp stub routine.
664   // Only enable the assert after the routine becomes available.
665   if (StubRoutines::code1() != NULL) {
666     assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
667   }
668 #endif
669 }
670 #endif
671 
672 int os::extra_bang_size_in_bytes() {
673   // JDK-8050147 requires the full cache line bang for x86.
674   return VM_Version::L1_line_size();
675 }
--- EOF ---