1 /*
2 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2016, 2018 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 "jvm.h"
30 #include "asm/assembler.inline.hpp"
31 #include "classfile/classLoader.hpp"
32 #include "classfile/systemDictionary.hpp"
33 #include "classfile/vmSymbols.hpp"
34 #include "code/icBuffer.hpp"
35 #include "code/nativeInst.hpp"
36 #include "code/vtableStubs.hpp"
37 #include "compiler/disassembler.hpp"
38 #include "interpreter/interpreter.hpp"
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_misc.hpp"
44 #include "runtime/arguments.hpp"
45 #include "runtime/extendedPC.hpp"
46 #include "runtime/frame.inline.hpp"
47 #include "runtime/interfaceSupport.inline.hpp"
48 #include "runtime/java.hpp"
49 #include "runtime/javaCalls.hpp"
50 #include "runtime/mutexLocker.hpp"
51 #include "runtime/osThread.hpp"
52 #include "runtime/sharedRuntime.hpp"
53 #include "runtime/stubRoutines.hpp"
54 #include "runtime/thread.inline.hpp"
55 #include "runtime/timer.hpp"
56 #include "utilities/events.hpp"
57 #include "utilities/vmError.hpp"
58
59 // put OS-includes here
60 # include <sys/types.h>
61 # include <sys/mman.h>
62 # include <pthread.h>
63 # include <signal.h>
64 # include <errno.h>
65 # include <dlfcn.h>
66 # include <stdlib.h>
67 # include <stdio.h>
68 # include <unistd.h>
69 # include <sys/resource.h>
70 # include <pthread.h>
71 # include <sys/stat.h>
72 # include <sys/time.h>
73 # include <sys/utsname.h>
74 # include <sys/socket.h>
75 # include <sys/wait.h>
76 # include <pwd.h>
77 # include <poll.h>
78 # include <ucontext.h>
79
80 address os::current_stack_pointer() {
81 intptr_t* csp;
82
83 // Inline assembly for `z_lgr regno(csp), Z_SP' (Z_SP = Z_R15):
84 __asm__ __volatile__ ("lgr %0, 15":"=r"(csp):);
85
86 assert(((uint64_t)csp & (frame::alignment_in_bytes-1)) == 0, "SP must be aligned");
87 return (address) csp;
88 }
89
90 char* os::non_memory_address_word() {
91 // Must never look like an address returned by reserve_memory,
92 // even in its subfields (as defined by the CPU immediate fields,
93 // if the CPU splits constants across multiple instructions).
94 return (char*) -1;
95 }
96
97 // OS specific thread initialization.
98 void os::initialize_thread(Thread* thread) { }
99
100 // Frame information (pc, sp, fp) retrieved via ucontext
101 // always looks like a C-frame according to the frame
102 // conventions in frame_s390.hpp.
103 address os::Linux::ucontext_get_pc(const ucontext_t * uc) {
104 return (address)uc->uc_mcontext.psw.addr;
105 }
106
107 void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) {
108 uc->uc_mcontext.psw.addr = (unsigned long)pc;
109 }
110
111 static address ucontext_get_lr(const ucontext_t * uc) {
112 return (address)uc->uc_mcontext.gregs[14/*LINK*/];
113 }
114
115 intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) {
116 return (intptr_t*)uc->uc_mcontext.gregs[15/*REG_SP*/];
117 }
118
119 intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) {
120 return NULL;
121 }
122
123 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
124 intptr_t** ret_sp, intptr_t** ret_fp) {
125
126 ExtendedPC epc;
127 const ucontext_t* uc = (const ucontext_t*)ucVoid;
128
129 if (uc != NULL) {
130 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
131 if (ret_sp) { *ret_sp = os::Linux::ucontext_get_sp(uc); }
132 if (ret_fp) { *ret_fp = os::Linux::ucontext_get_fp(uc); }
133 } else {
134 // Construct empty ExtendedPC for return value checking.
135 epc = ExtendedPC(NULL);
136 if (ret_sp) { *ret_sp = (intptr_t *)NULL; }
137 if (ret_fp) { *ret_fp = (intptr_t *)NULL; }
138 }
139
140 return epc;
141 }
142
143 frame os::fetch_frame_from_context(const void* ucVoid) {
144 intptr_t* sp;
145 intptr_t* fp;
146 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
147 return frame(sp, epc.pc());
148 }
149
150 bool os::Linux::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
151 address pc = (address) os::Linux::ucontext_get_pc(uc);
152 if (Interpreter::contains(pc)) {
153 // Interpreter performs stack banging after the fixed frame header has
154 // been generated while the compilers perform it before. To maintain
155 // semantic consistency between interpreted and compiled frames, the
156 // method returns the Java sender of the current frame.
157 *fr = os::fetch_frame_from_context(uc);
158 if (!fr->is_first_java_frame()) {
159 assert(fr->safe_for_sender(thread), "Safety check");
160 *fr = fr->java_sender();
161 }
162 } else {
163 // More complex code with compiled code.
164 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
165 CodeBlob* cb = CodeCache::find_blob(pc);
166 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
167 // Not sure where the pc points to, fallback to default
168 // stack overflow handling. In compiled code, we bang before
169 // the frame is complete.
170 return false;
171 } else {
172 intptr_t* sp = os::Linux::ucontext_get_sp(uc);
173 address lr = ucontext_get_lr(uc);
174 *fr = frame(sp, lr);
175 if (!fr->is_java_frame()) {
176 assert(fr->safe_for_sender(thread), "Safety check");
177 assert(!fr->is_first_frame(), "Safety check");
178 *fr = fr->java_sender();
179 }
180 }
181 }
182 assert(fr->is_java_frame(), "Safety check");
183 return true;
184 }
185
186 frame os::get_sender_for_C_frame(frame* fr) {
187 if (*fr->sp() == 0) {
188 // fr is the last C frame.
189 return frame();
190 }
191
192 // If its not one of our frames, the return pc is saved at gpr14
193 // stack slot. The call_stub stores the return_pc to the stack slot
194 // of gpr10.
195 if ((Interpreter::code() != NULL && Interpreter::contains(fr->pc())) ||
196 (CodeCache::contains(fr->pc()) && !StubRoutines::contains(fr->pc()))) {
197 return frame(fr->sender_sp(), fr->sender_pc());
198 } else {
199 if (StubRoutines::contains(fr->pc())) {
200 StubCodeDesc* desc = StubCodeDesc::desc_for(fr->pc());
201 if (desc && !strcmp(desc->name(),"call_stub")) {
202 return frame(fr->sender_sp(), fr->callstub_sender_pc());
203 } else {
204 return frame(fr->sender_sp(), fr->sender_pc());
205 }
206 } else {
207 return frame(fr->sender_sp(), fr->native_sender_pc());
208 }
209 }
210 }
211
212 frame os::current_frame() {
213 // Expected to return the stack pointer of this method.
214 // But if inlined, returns the stack pointer of our caller!
215 intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer());
216 assert (csp != NULL, "sp should not be NULL");
217 // Pass a dummy pc. This way we don't have to load it from the
218 // stack, since we don't know in which slot we can find it.
219 frame topframe(csp, (address)0x8);
220 if (os::is_first_C_frame(&topframe)) {
221 // Stack is not walkable.
222 return frame();
223 } else {
224 frame senderFrame = os::get_sender_for_C_frame(&topframe);
225 assert(senderFrame.pc() != NULL, "Sender pc should not be NULL");
226 // Return sender of sender of current topframe which hopefully
227 // both have pc != NULL.
228 #ifdef _NMT_NOINLINE_ // Is set in slowdebug builds.
229 // Current_stack_pointer is not inlined, we must pop one more frame.
230 frame tmp = os::get_sender_for_C_frame(&topframe);
231 return os::get_sender_for_C_frame(&tmp);
232 #else
233 return os::get_sender_for_C_frame(&topframe);
234 #endif
235 }
236 }
237
238 // Utility functions
239
240 extern "C" JNIEXPORT int
241 JVM_handle_linux_signal(int sig,
242 siginfo_t* info,
243 void* ucVoid,
244 int abort_if_unrecognized) {
245 ucontext_t* uc = (ucontext_t*) ucVoid;
246
247 Thread* t = Thread::current_or_null_safe();
248
249 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
250 // (no destructors can be run).
251 os::ThreadCrashProtection::check_crash_protection(sig, t);
252
253 SignalHandlerMark shm(t);
254
255 // Note: it's not uncommon that JNI code uses signal/sigset to install
256 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
257 // or have a SIGILL handler when detecting CPU type). When that happens,
258 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
259 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
260 // that do not require siginfo/ucontext first.
261
262 if (sig == SIGPIPE) {
263 if (os::Linux::chained_handler(sig, info, ucVoid)) {
264 return true;
265 } else {
266 if (PrintMiscellaneous && (WizardMode || Verbose)) {
267 warning("Ignoring SIGPIPE - see bug 4229104");
268 }
269 return true;
270 }
271 }
272
273 JavaThread* thread = NULL;
274 VMThread* vmthread = NULL;
275 if (os::Linux::signal_handlers_are_installed) {
276 if (t != NULL) {
277 if(t->is_Java_thread()) {
278 thread = (JavaThread*)t;
279 } else if(t->is_VM_thread()) {
280 vmthread = (VMThread *)t;
281 }
282 }
283 }
284
285 // Moved SafeFetch32 handling outside thread!=NULL conditional block to make
286 // it work if no associated JavaThread object exists.
287 if (uc) {
288 address const pc = os::Linux::ucontext_get_pc(uc);
289 if (pc && StubRoutines::is_safefetch_fault(pc)) {
290 os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
291 return true;
292 }
293 }
294
295 // Decide if this trap can be handled by a stub.
296 address stub = NULL;
297 address pc = NULL; // Pc as retrieved from PSW. Usually points past failing instruction.
298 address trap_pc = NULL; // Pc of the instruction causing the trap.
299
300 //%note os_trap_1
301 if (info != NULL && uc != NULL && thread != NULL) {
302 pc = os::Linux::ucontext_get_pc(uc);
303 if (TraceTraps) {
304 tty->print_cr(" pc at " INTPTR_FORMAT, p2i(pc));
305 }
306 if ((unsigned long)(pc - (address)info->si_addr) <= (unsigned long)Assembler::instr_maxlen() ) {
307 trap_pc = (address)info->si_addr;
308 if (TraceTraps) {
309 tty->print_cr("trap_pc at " INTPTR_FORMAT, p2i(trap_pc));
310 }
311 }
312
313 // Handle ALL stack overflow variations here
314 if (sig == SIGSEGV) {
315 address addr = (address)info->si_addr; // Address causing SIGSEGV, usually mem ref target.
316
317 // Check if fault address is within thread stack.
318 if (thread->on_local_stack(addr)) {
319 // stack overflow
320 if (thread->in_stack_yellow_reserved_zone(addr)) {
321 if (thread->thread_state() == _thread_in_Java) {
322 if (thread->in_stack_reserved_zone(addr)) {
323 frame fr;
324 if (os::Linux::get_frame_at_stack_banging_point(thread, uc, &fr)) {
325 assert(fr.is_java_frame(), "Must be a Javac frame");
326 frame activation =
327 SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
328 if (activation.sp() != NULL) {
329 thread->disable_stack_reserved_zone();
330 if (activation.is_interpreted_frame()) {
331 thread->set_reserved_stack_activation((address)activation.fp());
332 } else {
333 thread->set_reserved_stack_activation((address)activation.unextended_sp());
334 }
335 return 1;
336 }
337 }
338 }
339 // Throw a stack overflow exception.
340 // Guard pages will be reenabled while unwinding the stack.
341 thread->disable_stack_yellow_reserved_zone();
342 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
343 } else {
344 // Thread was in the vm or native code. Return and try to finish.
345 thread->disable_stack_yellow_reserved_zone();
346 return 1;
347 }
348 } else if (thread->in_stack_red_zone(addr)) {
349 // Fatal red zone violation. Disable the guard pages and fall through
350 // to handle_unexpected_exception way down below.
351 thread->disable_stack_red_zone();
352 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
353
354 // This is a likely cause, but hard to verify. Let's just print
355 // it as a hint.
356 tty->print_raw_cr("Please check if any of your loaded .so files has "
357 "enabled executable stack (see man page execstack(8))");
358 } else {
359 // Accessing stack address below sp may cause SEGV if current
360 // thread has MAP_GROWSDOWN stack. This should only happen when
361 // current thread was created by user code with MAP_GROWSDOWN flag
362 // and then attached to VM. See notes in os_linux.cpp.
363 if (thread->osthread()->expanding_stack() == 0) {
364 thread->osthread()->set_expanding_stack();
365 if (os::Linux::manually_expand_stack(thread, addr)) {
366 thread->osthread()->clear_expanding_stack();
367 return 1;
368 }
369 thread->osthread()->clear_expanding_stack();
370 } else {
371 fatal("recursive segv. expanding stack.");
372 }
373 }
374 }
375 }
376
377 if (thread->thread_state() == _thread_in_Java) {
378 // Java thread running in Java code => find exception handler if any
379 // a fault inside compiled code, the interpreter, or a stub
380
381 // Handle signal from NativeJump::patch_verified_entry().
382 if (sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant()) {
383 if (TraceTraps) {
384 tty->print_cr("trap: zombie_not_entrant (SIGILL)");
385 }
386 stub = SharedRuntime::get_handle_wrong_method_stub();
387 }
388
389 else if (sig == SIGSEGV &&
390 os::is_poll_address((address)info->si_addr)) {
391 if (TraceTraps) {
392 tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
393 }
394 stub = SharedRuntime::get_poll_stub(pc);
395
396 // Info->si_addr only points to the page base address, so we
397 // must extract the real si_addr from the instruction and the
398 // ucontext.
399 assert(((NativeInstruction*)pc)->is_safepoint_poll(), "must be safepoint poll");
400 const address real_si_addr = ((NativeInstruction*)pc)->get_poll_address(uc);
401 }
402
403 // SIGTRAP-based implicit null check in compiled code.
404 else if ((sig == SIGFPE) &&
405 TrapBasedNullChecks &&
406 (trap_pc != NULL) &&
407 Assembler::is_sigtrap_zero_check(trap_pc)) {
408 if (TraceTraps) {
409 tty->print_cr("trap: NULL_CHECK at " INTPTR_FORMAT " (SIGFPE)", p2i(trap_pc));
410 }
411 stub = SharedRuntime::continuation_for_implicit_exception(thread, trap_pc, SharedRuntime::IMPLICIT_NULL);
412 }
413
414 else if (sig == SIGSEGV && ImplicitNullChecks &&
415 CodeCache::contains((void*) pc) &&
416 !MacroAssembler::needs_explicit_null_check((intptr_t) info->si_addr)) {
417 if (TraceTraps) {
418 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
419 }
420 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
421 }
422
423 // SIGTRAP-based implicit range check in compiled code.
424 else if (sig == SIGFPE && TrapBasedRangeChecks &&
425 (trap_pc != NULL) &&
426 Assembler::is_sigtrap_range_check(trap_pc)) {
427 if (TraceTraps) {
428 tty->print_cr("trap: RANGE_CHECK at " INTPTR_FORMAT " (SIGFPE)", p2i(trap_pc));
429 }
430 stub = SharedRuntime::continuation_for_implicit_exception(thread, trap_pc, SharedRuntime::IMPLICIT_NULL);
431 }
432
433 else if (sig == SIGFPE && info->si_code == FPE_INTDIV) {
434 stub = SharedRuntime::continuation_for_implicit_exception(thread, trap_pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
435 }
436
437 else if (sig == SIGBUS) {
438 // BugId 4454115: A read from a MappedByteBuffer can fault here if the
439 // underlying file has been truncated. Do not crash the VM in such a case.
440 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
441 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
442 if (nm != NULL && nm->has_unsafe_access()) {
443 // We don't really need a stub here! Just set the pending exeption and
444 // continue at the next instruction after the faulting read. Returning
445 // garbage from this read is ok.
446 thread->set_pending_unsafe_access_error();
447 uc->uc_mcontext.psw.addr = ((unsigned long)pc) + Assembler::instr_len(pc);
448 return true;
449 }
450 }
451 }
452
453 else { // thread->thread_state() != _thread_in_Java
454 if ((sig == SIGILL) && VM_Version::is_determine_features_test_running()) {
455 // SIGILL must be caused by VM_Version::determine_features()
456 // when attempting to execute a non-existing instruction.
457 //*(int *) (pc-6)=0; // Patch instruction to 0 to indicate that it causes a SIGILL.
458 // Flushing of icache is not necessary.
459 stub = pc; // Continue with next instruction.
460 } else if ((sig == SIGFPE) && VM_Version::is_determine_features_test_running()) {
461 // SIGFPE is known to be caused by trying to execute a vector instruction
462 // when the vector facility is installed, but operating system support is missing.
463 VM_Version::reset_has_VectorFacility();
464 stub = pc; // Continue with next instruction.
465 } else if (thread->thread_state() == _thread_in_vm &&
466 sig == SIGBUS && thread->doing_unsafe_access()) {
467 // We don't really need a stub here! Just set the pending exeption and
468 // continue at the next instruction after the faulting read. Returning
469 // garbage from this read is ok.
470 thread->set_pending_unsafe_access_error();
471 os::Linux::ucontext_set_pc(uc, pc + Assembler::instr_len(pc));
472 return true;
473 }
474 }
475
476 // Check to see if we caught the safepoint code in the
477 // process of write protecting the memory serialization page.
478 // It write enables the page immediately after protecting it
479 // so we can just return to retry the write.
480 // Info->si_addr need not be the exact address, it is only
481 // guaranteed to be on the same page as the address that caused
482 // the SIGSEGV.
483 if ((sig == SIGSEGV) && !UseMembar &&
484 (os::get_memory_serialize_page() ==
485 (address)((uintptr_t)info->si_addr & ~(os::vm_page_size()-1)))) {
486 return true;
487 }
488 }
489
490 if (stub != NULL) {
491 // Save all thread context in case we need to restore it.
492 if (thread != NULL) thread->set_saved_exception_pc(pc);
493 os::Linux::ucontext_set_pc(uc, stub);
494 return true;
495 }
496
497 // signal-chaining
498 if (os::Linux::chained_handler(sig, info, ucVoid)) {
499 return true;
500 }
501
502 if (!abort_if_unrecognized) {
503 // caller wants another chance, so give it to him
504 return false;
505 }
506
507 if (pc == NULL && uc != NULL) {
508 pc = os::Linux::ucontext_get_pc(uc);
509 }
510
511 // unmask current signal
512 sigset_t newset;
513 sigemptyset(&newset);
514 sigaddset(&newset, sig);
515 sigprocmask(SIG_UNBLOCK, &newset, NULL);
516
517 // Hand down correct pc for SIGILL, SIGFPE. pc from context
518 // usually points to the instruction after the failing instruction.
519 // Note: this should be combined with the trap_pc handling above,
520 // because it handles the same issue.
521 if (sig == SIGILL || sig == SIGFPE) {
522 pc = (address)info->si_addr;
523 }
524
525 VMError::report_and_die(t, sig, pc, info, ucVoid);
526
527 ShouldNotReachHere();
528 return false;
529 }
530
531 void os::Linux::init_thread_fpu_state(void) {
532 // Nothing to do on z/Architecture.
533 }
534
535 int os::Linux::get_fpu_control_word(void) {
536 // Nothing to do on z/Architecture.
537 return 0;
538 }
539
540 void os::Linux::set_fpu_control_word(int fpu_control) {
541 // Nothing to do on z/Architecture.
542 }
543
544 ////////////////////////////////////////////////////////////////////////////////
545 // thread stack
546
547 // Minimum usable stack sizes required to get to user code. Space for
548 // HotSpot guard pages is added later.
549 size_t os::Posix::_compiler_thread_min_stack_allowed = (52 DEBUG_ONLY(+ 32)) * K;
550 size_t os::Posix::_java_thread_min_stack_allowed = (32 DEBUG_ONLY(+ 8)) * K;
551 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 32 * K;
552
553 // Return default stack size for thr_type.
554 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
555 // Default stack size (compiler thread needs larger stack).
556 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1024 * K);
557 return s;
558 }
559
560 /////////////////////////////////////////////////////////////////////////////
561 // helper functions for fatal error handler
562
563 void os::print_context(outputStream *st, const void *context) {
564 if (context == NULL) return;
565
566 const ucontext_t* uc = (const ucontext_t*)context;
567
568 st->print_cr("Processor state:");
569 st->print_cr("----------------");
570 st->print_cr(" ip = " INTPTR_FORMAT " ", uc->uc_mcontext.psw.addr);
571 st->print_cr(" proc mask = " INTPTR_FORMAT " ", uc->uc_mcontext.psw.mask);
572 st->print_cr(" fpc reg = 0x%8.8x " , uc->uc_mcontext.fpregs.fpc);
573 st->cr();
574
575 st->print_cr("General Purpose Registers:");
576 st->print_cr("--------------------------");
577 for( int i = 0; i < 16; i+=2 ) {
578 st->print(" r%-2d = " INTPTR_FORMAT " " , i, uc->uc_mcontext.gregs[i]);
579 st->print(" r%-2d = " INTPTR_FORMAT " |", i+1, uc->uc_mcontext.gregs[i+1]);
580 st->print(" r%-2d = %23.1ld " , i, uc->uc_mcontext.gregs[i]);
581 st->print(" r%-2d = %23.1ld " , i+1, uc->uc_mcontext.gregs[i+1]);
582 st->cr();
583 }
584 st->cr();
585
586 st->print_cr("Access Registers:");
587 st->print_cr("-----------------");
588 for( int i = 0; i < 16; i+=2 ) {
589 st->print(" ar%-2d = 0x%8.8x ", i, uc->uc_mcontext.aregs[i]);
590 st->print(" ar%-2d = 0x%8.8x ", i+1, uc->uc_mcontext.aregs[i+1]);
591 st->cr();
592 }
593 st->cr();
594
595 st->print_cr("Float Registers:");
596 st->print_cr("----------------");
597 for (int i = 0; i < 16; i += 2) {
598 st->print(" fr%-2d = " INTPTR_FORMAT " " , i, (int64_t)(uc->uc_mcontext.fpregs.fprs[i].d));
599 st->print(" fr%-2d = " INTPTR_FORMAT " |", i+1, (int64_t)(uc->uc_mcontext.fpregs.fprs[i+1].d));
600 st->print(" fr%-2d = %23.15e " , i, (uc->uc_mcontext.fpregs.fprs[i].d));
601 st->print(" fr%-2d = %23.15e " , i+1, (uc->uc_mcontext.fpregs.fprs[i+1].d));
602 st->cr();
603 }
604 st->cr();
605 st->cr();
606
607 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
608 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp));
609 print_hex_dump(st, (address)sp, (address)(sp + 128), sizeof(intptr_t));
610 st->cr();
611
612 // Note: it may be unsafe to inspect memory near pc. For example, pc may
613 // point to garbage if entry point in an nmethod is corrupted. Leave
614 // this at the end, and hope for the best.
615 address pc = os::Linux::ucontext_get_pc(uc);
616 if (Verbose) { st->print_cr("pc at " PTR_FORMAT, p2i(pc)); }
617 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc));
618 print_hex_dump(st, pc-64, pc+64, /*intrsize=*/4);
619 st->cr();
620 }
621
622 void os::print_register_info(outputStream *st, const void *context) {
623 st->print("Not ported\n");
624 }
625
626 #ifndef PRODUCT
627 void os::verify_stack_alignment() {
628 }
629 #endif
630
631 int os::extra_bang_size_in_bytes() {
632 // z/Architecture does not require the additional stack bang.
633 return 0;
634 }