1 /*
2 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2016 SAP SE. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 // This file is organized as os_linux_x86.cpp.
27
28 // no precompiled headers
29 #include "asm/assembler.inline.hpp"
30 #include "classfile/classLoader.hpp"
31 #include "classfile/systemDictionary.hpp"
32 #include "classfile/vmSymbols.hpp"
33 #include "code/icBuffer.hpp"
34 #include "code/nativeInst.hpp"
35 #include "code/vtableStubs.hpp"
36 #include "compiler/disassembler.hpp"
37 #include "interpreter/interpreter.hpp"
38 #include "jvm_linux.h"
39 #include "memory/allocation.inline.hpp"
40 #include "nativeInst_s390.hpp"
41 #include "os_share_linux.hpp"
42 #include "prims/jniFastGetField.hpp"
43 #include "prims/jvm.h"
44 #include "prims/jvm_misc.hpp"
45 #include "runtime/arguments.hpp"
46 #include "runtime/extendedPC.hpp"
47 #include "runtime/frame.inline.hpp"
48 #include "runtime/interfaceSupport.hpp"
49 #include "runtime/java.hpp"
50 #include "runtime/javaCalls.hpp"
51 #include "runtime/mutexLocker.hpp"
52 #include "runtime/osThread.hpp"
53 #include "runtime/sharedRuntime.hpp"
54 #include "runtime/stubRoutines.hpp"
55 #include "runtime/thread.inline.hpp"
56 #include "runtime/timer.hpp"
57 #include "utilities/events.hpp"
58 #include "utilities/vmError.hpp"
59
60 // put OS-includes here
61 # include <sys/types.h>
62 # include <sys/mman.h>
63 # include <pthread.h>
64 # include <signal.h>
65 # include <errno.h>
66 # include <dlfcn.h>
67 # include <stdlib.h>
68 # include <stdio.h>
69 # include <unistd.h>
70 # include <sys/resource.h>
71 # include <pthread.h>
72 # include <sys/stat.h>
73 # include <sys/time.h>
74 # include <sys/utsname.h>
75 # include <sys/socket.h>
76 # include <sys/wait.h>
77 # include <pwd.h>
78 # include <poll.h>
79 # include <ucontext.h>
80
81 address os::current_stack_pointer() {
82 intptr_t* csp;
83
84 // Inline assembly for `z_lgr regno(csp), Z_SP' (Z_SP = Z_R15):
85 __asm__ __volatile__ ("lgr %0, 15":"=r"(csp):);
86
87 assert(((uint64_t)csp & (frame::alignment_in_bytes-1)) == 0, "SP must be aligned");
88 return (address) csp;
89 }
90
91 char* os::non_memory_address_word() {
92 // Must never look like an address returned by reserve_memory,
93 // even in its subfields (as defined by the CPU immediate fields,
94 // if the CPU splits constants across multiple instructions).
95 return (char*) -1;
96 }
97
98 // OS specific thread initialization.
99 void os::initialize_thread(Thread* thread) { }
100
101 // Frame information (pc, sp, fp) retrieved via ucontext
102 // always looks like a C-frame according to the frame
103 // conventions in frame_s390.hpp.
104 address os::Linux::ucontext_get_pc(const ucontext_t * uc) {
105 return (address)uc->uc_mcontext.psw.addr;
106 }
107
108 void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) {
109 uc->uc_mcontext.psw.addr = (unsigned long)pc;
110 }
111
112 intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) {
113 return (intptr_t*)uc->uc_mcontext.gregs[15/*REG_SP*/];
114 }
115
116 intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) {
117 return NULL;
118 }
119
120 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
121 intptr_t** ret_sp, intptr_t** ret_fp) {
122
123 ExtendedPC epc;
124 const ucontext_t* uc = (const ucontext_t*)ucVoid;
125
126 if (uc != NULL) {
127 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
128 if (ret_sp) { *ret_sp = os::Linux::ucontext_get_sp(uc); }
129 if (ret_fp) { *ret_fp = os::Linux::ucontext_get_fp(uc); }
130 } else {
131 // Construct empty ExtendedPC for return value checking.
132 epc = ExtendedPC(NULL);
133 if (ret_sp) { *ret_sp = (intptr_t *)NULL; }
134 if (ret_fp) { *ret_fp = (intptr_t *)NULL; }
135 }
136
137 return epc;
138 }
139
140 frame os::fetch_frame_from_context(const void* ucVoid) {
141 intptr_t* sp;
142 intptr_t* fp;
143 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
144 return frame(sp, epc.pc());
145 }
146
147 bool os::Linux::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
148 address pc = (address) os::Linux::ucontext_get_pc(uc);
149 if (Interpreter::contains(pc)) {
150 // Interpreter performs stack banging after the fixed frame header has
151 // been generated while the compilers perform it before. To maintain
152 // semantic consistency between interpreted and compiled frames, the
153 // method returns the Java sender of the current frame.
154 *fr = os::fetch_frame_from_context(uc);
155 if (!fr->is_first_java_frame()) {
156 assert(fr->safe_for_sender(thread), "Safety check");
157 *fr = fr->java_sender();
158 }
159 } else {
160 // More complex code with compiled code.
161 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
162 CodeBlob* cb = CodeCache::find_blob(pc);
163 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
164 // Not sure where the pc points to, fallback to default
165 // stack overflow handling. In compiled code, we bang before
166 // the frame is complete.
167 return false;
168 } else {
169 intptr_t* fp = os::Linux::ucontext_get_fp(uc);
170 intptr_t* sp = os::Linux::ucontext_get_sp(uc);
171 *fr = frame(sp, (address)*sp);
172 if (!fr->is_java_frame()) {
173 assert(fr->safe_for_sender(thread), "Safety check");
174 assert(!fr->is_first_frame(), "Safety check");
175 *fr = fr->java_sender();
176 }
177 }
178 }
179 assert(fr->is_java_frame(), "Safety check");
180 return true;
181 }
182
183 frame os::get_sender_for_C_frame(frame* fr) {
184 if (*fr->sp() == 0) {
185 // fr is the last C frame.
186 return frame();
187 }
188
189 // If its not one of our frames, the return pc is saved at gpr14
190 // stack slot. The call_stub stores the return_pc to the stack slot
191 // of gpr10.
192 if ((Interpreter::code() != NULL && Interpreter::contains(fr->pc())) ||
193 (CodeCache::contains(fr->pc()) && !StubRoutines::contains(fr->pc()))) {
194 return frame(fr->sender_sp(), fr->sender_pc());
195 } else {
196 if (StubRoutines::contains(fr->pc())) {
197 StubCodeDesc* desc = StubCodeDesc::desc_for(fr->pc());
198 if (desc && !strcmp(desc->name(),"call_stub")) {
199 return frame(fr->sender_sp(), fr->callstub_sender_pc());
200 } else {
201 return frame(fr->sender_sp(), fr->sender_pc());
202 }
203 } else {
204 return frame(fr->sender_sp(), fr->native_sender_pc());
205 }
206 }
207 }
208
209 frame os::current_frame() {
210 // Expected to return the stack pointer of this method.
211 // But if inlined, returns the stack pointer of our caller!
212 intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer());
213 assert (csp != NULL, "sp should not be NULL");
214 // Pass a dummy pc. This way we don't have to load it from the
215 // stack, since we don't know in which slot we can find it.
216 frame topframe(csp, (address)0x8);
217 if (os::is_first_C_frame(&topframe)) {
218 // Stack is not walkable.
219 return frame();
220 } else {
221 frame senderFrame = os::get_sender_for_C_frame(&topframe);
222 assert(senderFrame.pc() != NULL, "Sender pc should not be NULL");
223 // Return sender of sender of current topframe which hopefully
224 // both have pc != NULL.
225 #ifdef _NMT_NOINLINE_ // Is set in slowdebug builds.
226 // Current_stack_pointer is not inlined, we must pop one more frame.
227 frame tmp = os::get_sender_for_C_frame(&topframe);
228 return os::get_sender_for_C_frame(&tmp);
229 #else
230 return os::get_sender_for_C_frame(&topframe);
231 #endif
232 }
233 }
234
235 // Utility functions
236
237 extern "C" JNIEXPORT int
238 JVM_handle_linux_signal(int sig,
239 siginfo_t* info,
240 void* ucVoid,
241 int abort_if_unrecognized) {
242 ucontext_t* uc = (ucontext_t*) ucVoid;
243
244 Thread* t = Thread::current_or_null_safe();
245
246 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
247 // (no destructors can be run).
248 os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
249
250 SignalHandlerMark shm(t);
251
252 // Note: it's not uncommon that JNI code uses signal/sigset to install
253 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
254 // or have a SIGILL handler when detecting CPU type). When that happens,
255 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
256 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
257 // that do not require siginfo/ucontext first.
258
259 if (sig == SIGPIPE) {
260 if (os::Linux::chained_handler(sig, info, ucVoid)) {
261 return true;
262 } else {
263 if (PrintMiscellaneous && (WizardMode || Verbose)) {
264 warning("Ignoring SIGPIPE - see bug 4229104");
265 }
266 return true;
267 }
268 }
269
270 JavaThread* thread = NULL;
271 VMThread* vmthread = NULL;
272 if (os::Linux::signal_handlers_are_installed) {
273 if (t != NULL) {
274 if(t->is_Java_thread()) {
275 thread = (JavaThread*)t;
276 } else if(t->is_VM_thread()) {
277 vmthread = (VMThread *)t;
278 }
279 }
280 }
281
282 // Moved SafeFetch32 handling outside thread!=NULL conditional block to make
283 // it work if no associated JavaThread object exists.
284 if (uc) {
285 address const pc = os::Linux::ucontext_get_pc(uc);
286 if (pc && StubRoutines::is_safefetch_fault(pc)) {
287 os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
288 return true;
289 }
290 }
291
292 // Decide if this trap can be handled by a stub.
293 address stub = NULL;
294 address pc = NULL; // Pc as retrieved from PSW. Usually points past failing instruction.
295 address trap_pc = NULL; // Pc of the instruction causing the trap.
296
297 //%note os_trap_1
298 if (info != NULL && uc != NULL && thread != NULL) {
299 pc = os::Linux::ucontext_get_pc(uc);
300 if (TraceTraps) {
301 tty->print_cr(" pc at " INTPTR_FORMAT, p2i(pc));
302 }
303 if ((unsigned long)(pc - (address)info->si_addr) <= (unsigned long)Assembler::instr_maxlen() ) {
304 trap_pc = (address)info->si_addr;
305 if (TraceTraps) {
306 tty->print_cr("trap_pc at " INTPTR_FORMAT, p2i(trap_pc));
307 }
308 }
309
310 // Handle ALL stack overflow variations here
311 if (sig == SIGSEGV) {
312 address addr = (address)info->si_addr; // Address causing SIGSEGV, usually mem ref target.
313
314 // Check if fault address is within thread stack.
315 if (thread->on_local_stack(addr)) {
316 // stack overflow
317 if (thread->in_stack_yellow_reserved_zone(addr)) {
318 if (thread->thread_state() == _thread_in_Java) {
319 if (thread->in_stack_reserved_zone(addr)) {
320 frame fr;
321 if (os::Linux::get_frame_at_stack_banging_point(thread, uc, &fr)) {
322 assert(fr.is_java_frame(), "Must be a Javac frame");
323 frame activation =
324 SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
325 if (activation.sp() != NULL) {
326 thread->disable_stack_reserved_zone();
327 if (activation.is_interpreted_frame()) {
328 thread->set_reserved_stack_activation((address)activation.fp());
329 } else {
330 thread->set_reserved_stack_activation((address)activation.unextended_sp());
331 }
332 return 1;
333 }
334 }
335 }
336 // Throw a stack overflow exception.
337 // Guard pages will be reenabled while unwinding the stack.
338 thread->disable_stack_yellow_reserved_zone();
339 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
340 } else {
341 // Thread was in the vm or native code. Return and try to finish.
342 thread->disable_stack_yellow_reserved_zone();
343 return 1;
344 }
345 } else if (thread->in_stack_red_zone(addr)) {
346 // Fatal red zone violation. Disable the guard pages and fall through
347 // to handle_unexpected_exception way down below.
348 thread->disable_stack_red_zone();
349 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
350
351 // This is a likely cause, but hard to verify. Let's just print
352 // it as a hint.
353 tty->print_raw_cr("Please check if any of your loaded .so files has "
354 "enabled executable stack (see man page execstack(8))");
355 } else {
356 // Accessing stack address below sp may cause SEGV if current
357 // thread has MAP_GROWSDOWN stack. This should only happen when
358 // current thread was created by user code with MAP_GROWSDOWN flag
359 // and then attached to VM. See notes in os_linux.cpp.
360 if (thread->osthread()->expanding_stack() == 0) {
361 thread->osthread()->set_expanding_stack();
362 if (os::Linux::manually_expand_stack(thread, addr)) {
363 thread->osthread()->clear_expanding_stack();
364 return 1;
365 }
366 thread->osthread()->clear_expanding_stack();
367 } else {
368 fatal("recursive segv. expanding stack.");
369 }
370 }
371 }
372 }
373
374 if (thread->thread_state() == _thread_in_Java) {
375 // Java thread running in Java code => find exception handler if any
376 // a fault inside compiled code, the interpreter, or a stub
377
378 // Handle signal from NativeJump::patch_verified_entry().
379 if (sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant()) {
380 if (TraceTraps) {
381 tty->print_cr("trap: zombie_not_entrant (SIGILL)");
382 }
383 stub = SharedRuntime::get_handle_wrong_method_stub();
384 }
385
386 else if (sig == SIGSEGV &&
387 os::is_poll_address((address)info->si_addr)) {
388 if (TraceTraps) {
389 tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
390 }
391 stub = SharedRuntime::get_poll_stub(pc);
392
393 // Info->si_addr only points to the page base address, so we
394 // must extract the real si_addr from the instruction and the
395 // ucontext.
396 assert(((NativeInstruction*)pc)->is_safepoint_poll(), "must be safepoint poll");
397 const address real_si_addr = ((NativeInstruction*)pc)->get_poll_address(uc);
398 }
399
400 // SIGTRAP-based implicit null check in compiled code.
401 else if ((sig == SIGFPE) &&
402 TrapBasedNullChecks &&
403 (trap_pc != NULL) &&
404 Assembler::is_sigtrap_zero_check(trap_pc)) {
405 if (TraceTraps) {
406 tty->print_cr("trap: NULL_CHECK at " INTPTR_FORMAT " (SIGFPE)", p2i(trap_pc));
407 }
408 stub = SharedRuntime::continuation_for_implicit_exception(thread, trap_pc, SharedRuntime::IMPLICIT_NULL);
409 }
410
411 else if (sig == SIGSEGV && ImplicitNullChecks &&
412 CodeCache::contains((void*) pc) &&
413 !MacroAssembler::needs_explicit_null_check((intptr_t) info->si_addr)) {
414 if (TraceTraps) {
415 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
416 }
417 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
418 }
419
420 // SIGTRAP-based implicit range check in compiled code.
421 else if (sig == SIGFPE && TrapBasedRangeChecks &&
422 (trap_pc != NULL) &&
423 Assembler::is_sigtrap_range_check(trap_pc)) {
424 if (TraceTraps) {
425 tty->print_cr("trap: RANGE_CHECK at " INTPTR_FORMAT " (SIGFPE)", p2i(trap_pc));
426 }
427 stub = SharedRuntime::continuation_for_implicit_exception(thread, trap_pc, SharedRuntime::IMPLICIT_NULL);
428 }
429
430 else if (sig == SIGFPE && info->si_code == FPE_INTDIV) {
431 stub = SharedRuntime::continuation_for_implicit_exception(thread, trap_pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
432 }
433
434 else if (sig == SIGBUS) {
435 // BugId 4454115: A read from a MappedByteBuffer can fault here if the
436 // underlying file has been truncated. Do not crash the VM in such a case.
437 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
438 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
439 if (nm != NULL && nm->has_unsafe_access()) {
440 // We don't really need a stub here! Just set the pending exeption and
441 // continue at the next instruction after the faulting read. Returning
442 // garbage from this read is ok.
443 thread->set_pending_unsafe_access_error();
444 uc->uc_mcontext.psw.addr = ((unsigned long)pc) + Assembler::instr_len(pc);
445 return true;
446 }
447 }
448 }
449
450 else { // thread->thread_state() != _thread_in_Java
451 if (sig == SIGILL && VM_Version::is_determine_features_test_running()) {
452 // SIGILL must be caused by VM_Version::determine_features().
453 //*(int *) (pc-6)=0; // Patch instruction to 0 to indicate that it causes a SIGILL.
454 // Flushing of icache is not necessary.
455 stub = pc; // Continue with next instruction.
456 } else if (thread->thread_state() == _thread_in_vm &&
457 sig == SIGBUS && thread->doing_unsafe_access()) {
458 // We don't really need a stub here! Just set the pending exeption and
459 // continue at the next instruction after the faulting read. Returning
460 // garbage from this read is ok.
461 thread->set_pending_unsafe_access_error();
462 os::Linux::ucontext_set_pc(uc, pc + Assembler::instr_len(pc));
463 return true;
464 }
465 }
466
467 // Check to see if we caught the safepoint code in the
468 // process of write protecting the memory serialization page.
469 // It write enables the page immediately after protecting it
470 // so we can just return to retry the write.
471 // Info->si_addr need not be the exact address, it is only
472 // guaranteed to be on the same page as the address that caused
473 // the SIGSEGV.
474 if ((sig == SIGSEGV) &&
475 (os::get_memory_serialize_page() ==
476 (address)((uintptr_t)info->si_addr & ~(os::vm_page_size()-1)))) {
477 return true;
478 }
479 }
480
481 if (stub != NULL) {
482 // Save all thread context in case we need to restore it.
483 if (thread != NULL) thread->set_saved_exception_pc(pc);
484 os::Linux::ucontext_set_pc(uc, stub);
485 return true;
486 }
487
488 // signal-chaining
489 if (os::Linux::chained_handler(sig, info, ucVoid)) {
490 return true;
491 }
492
493 if (!abort_if_unrecognized) {
494 // caller wants another chance, so give it to him
495 return false;
496 }
497
498 if (pc == NULL && uc != NULL) {
499 pc = os::Linux::ucontext_get_pc(uc);
500 }
501
502 // unmask current signal
503 sigset_t newset;
504 sigemptyset(&newset);
505 sigaddset(&newset, sig);
506 sigprocmask(SIG_UNBLOCK, &newset, NULL);
507
508 VMError::report_and_die(t, sig, pc, info, ucVoid);
509
510 ShouldNotReachHere();
511 return false;
512 }
513
514 void os::Linux::init_thread_fpu_state(void) {
515 // Nothing to do on z/Architecture.
516 }
517
518 int os::Linux::get_fpu_control_word(void) {
519 // Nothing to do on z/Architecture.
520 return 0;
521 }
522
523 void os::Linux::set_fpu_control_word(int fpu_control) {
524 // Nothing to do on z/Architecture.
525 }
526
527 ////////////////////////////////////////////////////////////////////////////////
528 // thread stack
529
530 // Minimum usable stack sizes required to get to user code. Space for
531 // HotSpot guard pages is added later.
532 size_t os::Posix::_compiler_thread_min_stack_allowed = (52 DEBUG_ONLY(+ 32)) * K;
533 size_t os::Posix::_java_thread_min_stack_allowed = (32 DEBUG_ONLY(+ 8)) * K;
534 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 32 * K;
535
536 // Return default stack size for thr_type.
537 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
538 // Default stack size (compiler thread needs larger stack).
539 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1024 * K);
540 return s;
541 }
542
543 /////////////////////////////////////////////////////////////////////////////
544 // helper functions for fatal error handler
545
546 void os::print_context(outputStream *st, const void *context) {
547 if (context == NULL) return;
548
549 const ucontext_t* uc = (const ucontext_t*)context;
550
551 st->print_cr("Processor state:");
552 st->print_cr("----------------");
553 st->print_cr(" ip = " INTPTR_FORMAT " ", uc->uc_mcontext.psw.addr);
554 st->print_cr(" proc mask = " INTPTR_FORMAT " ", uc->uc_mcontext.psw.mask);
555 st->print_cr(" fpc reg = 0x%8.8x " , uc->uc_mcontext.fpregs.fpc);
556 st->cr();
557
558 st->print_cr("General Purpose Registers:");
559 st->print_cr("--------------------------");
560 for( int i = 0; i < 16; i+=2 ) {
561 st->print(" r%-2d = " INTPTR_FORMAT " " , i, uc->uc_mcontext.gregs[i]);
562 st->print(" r%-2d = " INTPTR_FORMAT " |", i+1, uc->uc_mcontext.gregs[i+1]);
563 st->print(" r%-2d = %23.1ld " , i, uc->uc_mcontext.gregs[i]);
564 st->print(" r%-2d = %23.1ld " , i+1, uc->uc_mcontext.gregs[i+1]);
565 st->cr();
566 }
567 st->cr();
568
569 st->print_cr("Access Registers:");
570 st->print_cr("-----------------");
571 for( int i = 0; i < 16; i+=2 ) {
572 st->print(" ar%-2d = 0x%8.8x ", i, uc->uc_mcontext.aregs[i]);
573 st->print(" ar%-2d = 0x%8.8x ", i+1, uc->uc_mcontext.aregs[i+1]);
574 st->cr();
575 }
576 st->cr();
577
578 st->print_cr("Float Registers:");
579 st->print_cr("----------------");
580 for (int i = 0; i < 16; i += 2) {
581 st->print(" fr%-2d = " INTPTR_FORMAT " " , i, (int64_t)(uc->uc_mcontext.fpregs.fprs[i].d));
582 st->print(" fr%-2d = " INTPTR_FORMAT " |", i+1, (int64_t)(uc->uc_mcontext.fpregs.fprs[i+1].d));
583 st->print(" fr%-2d = %23.15e " , i, (uc->uc_mcontext.fpregs.fprs[i].d));
584 st->print(" fr%-2d = %23.15e " , i+1, (uc->uc_mcontext.fpregs.fprs[i+1].d));
585 st->cr();
586 }
587 st->cr();
588 st->cr();
589
590 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
591 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp));
592 print_hex_dump(st, (address)sp, (address)(sp + 128), sizeof(intptr_t));
593 st->cr();
594
595 // Note: it may be unsafe to inspect memory near pc. For example, pc may
596 // point to garbage if entry point in an nmethod is corrupted. Leave
597 // this at the end, and hope for the best.
598 address pc = os::Linux::ucontext_get_pc(uc);
599 if (Verbose) { st->print_cr("pc at " PTR_FORMAT, p2i(pc)); }
600 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc));
601 print_hex_dump(st, pc-64, pc+64, /*intrsize=*/4);
602 st->cr();
603 }
604
605 void os::print_register_info(outputStream *st, const void *context) {
606 st->print("Not ported\n");
607 }
608
609 #ifndef PRODUCT
610 void os::verify_stack_alignment() {
611 }
612 #endif
613
614 int os::extra_bang_size_in_bytes() {
615 // z/Architecture does not require the additional stack bang.
616 return 0;
617 }