1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2012, 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 // no precompiled headers
27 #include "jvm.h"
28 #include "asm/assembler.inline.hpp"
29 #include "classfile/classLoader.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "classfile/vmSymbols.hpp"
32 #include "code/codeCache.hpp"
33 #include "code/icBuffer.hpp"
34 #include "code/vtableStubs.hpp"
35 #include "interpreter/interpreter.hpp"
36 #include "memory/allocation.inline.hpp"
37 #include "nativeInst_ppc.hpp"
38 #include "os_share_linux.hpp"
39 #include "prims/jniFastGetField.hpp"
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.inline.hpp"
45 #include "runtime/java.hpp"
46 #include "runtime/javaCalls.hpp"
47 #include "runtime/mutexLocker.hpp"
48 #include "runtime/osThread.hpp"
49 #include "runtime/safepointMechanism.hpp"
50 #include "runtime/sharedRuntime.hpp"
51 #include "runtime/stubRoutines.hpp"
52 #include "runtime/thread.inline.hpp"
53 #include "runtime/timer.hpp"
54 #include "utilities/debug.hpp"
55 #include "utilities/events.hpp"
56 #include "utilities/vmError.hpp"
57
58 // put OS-includes here
59 # include <sys/types.h>
60 # include <sys/mman.h>
61 # include <pthread.h>
62 # include <signal.h>
63 # include <errno.h>
64 # include <dlfcn.h>
65 # include <stdlib.h>
66 # include <stdio.h>
67 # include <unistd.h>
68 # include <sys/resource.h>
69 # include <pthread.h>
70 # include <sys/stat.h>
71 # include <sys/time.h>
72 # include <sys/utsname.h>
73 # include <sys/socket.h>
74 # include <sys/wait.h>
75 # include <pwd.h>
76 # include <poll.h>
77 # include <ucontext.h>
78
79
80 address os::current_stack_pointer() {
81 intptr_t* csp;
82
83 // inline assembly `mr regno(csp), R1_SP':
84 __asm__ __volatile__ ("mr %0, 1":"=r"(csp):);
85
86 return (address) csp;
87 }
88
89 char* os::non_memory_address_word() {
90 // Must never look like an address returned by reserve_memory,
91 // even in its subfields (as defined by the CPU immediate fields,
92 // if the CPU splits constants across multiple instructions).
93
94 return (char*) -1;
95 }
96
97 // Frame information (pc, sp, fp) retrieved via ucontext
98 // always looks like a C-frame according to the frame
99 // conventions in frame_ppc64.hpp.
100 address os::Linux::ucontext_get_pc(const ucontext_t * uc) {
101 // On powerpc64, ucontext_t is not selfcontained but contains
102 // a pointer to an optional substructure (mcontext_t.regs) containing the volatile
103 // registers - NIP, among others.
104 // This substructure may or may not be there depending where uc came from:
105 // - if uc was handed over as the argument to a sigaction handler, a pointer to the
106 // substructure was provided by the kernel when calling the signal handler, and
107 // regs->nip can be accessed.
108 // - if uc was filled by getcontext(), it is undefined - getcontext() does not fill
109 // it because the volatile registers are not needed to make setcontext() work.
110 // Hopefully it was zero'd out beforehand.
111 guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_get_pc in sigaction context");
112 return (address)uc->uc_mcontext.regs->nip;
113 }
114
115 // modify PC in ucontext.
116 // Note: Only use this for an ucontext handed down to a signal handler. See comment
117 // in ucontext_get_pc.
118 void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) {
119 guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_set_pc in sigaction context");
120 uc->uc_mcontext.regs->nip = (unsigned long)pc;
121 }
122
123 static address ucontext_get_lr(const ucontext_t * uc) {
124 return (address)uc->uc_mcontext.regs->link;
125 }
126
127 intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) {
128 return (intptr_t*)uc->uc_mcontext.regs->gpr[1/*REG_SP*/];
129 }
130
131 intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) {
132 return NULL;
133 }
134
135 static unsigned long ucontext_get_trap(const ucontext_t * uc) {
136 return uc->uc_mcontext.regs->trap;
137 }
138
139 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
140 intptr_t** ret_sp, intptr_t** ret_fp) {
141
142 ExtendedPC epc;
143 const ucontext_t* uc = (const ucontext_t*)ucVoid;
144
145 if (uc != NULL) {
146 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
147 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc);
148 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc);
149 } else {
150 // construct empty ExtendedPC for return value checking
151 epc = ExtendedPC(NULL);
152 if (ret_sp) *ret_sp = (intptr_t *)NULL;
153 if (ret_fp) *ret_fp = (intptr_t *)NULL;
154 }
155
156 return epc;
157 }
158
159 frame os::fetch_frame_from_context(const void* ucVoid) {
160 intptr_t* sp;
161 intptr_t* fp;
162 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
163 return frame(sp, epc.pc());
164 }
165
166 bool os::Linux::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
167 address pc = (address) os::Linux::ucontext_get_pc(uc);
168 if (Interpreter::contains(pc)) {
169 // Interpreter performs stack banging after the fixed frame header has
170 // been generated while the compilers perform it before. To maintain
171 // semantic consistency between interpreted and compiled frames, the
172 // method returns the Java sender of the current frame.
173 *fr = os::fetch_frame_from_context(uc);
174 if (!fr->is_first_java_frame()) {
175 assert(fr->safe_for_sender(thread), "Safety check");
176 *fr = fr->java_sender();
177 }
178 } else {
179 // More complex code with compiled code.
180 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
181 CodeBlob* cb = CodeCache::find_blob(pc);
182 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
183 // Not sure where the pc points to, fallback to default
184 // stack overflow handling. In compiled code, we bang before
185 // the frame is complete.
186 return false;
187 } else {
188 intptr_t* sp = os::Linux::ucontext_get_sp(uc);
189 address lr = ucontext_get_lr(uc);
190 *fr = frame(sp, lr);
191 if (!fr->is_java_frame()) {
192 assert(fr->safe_for_sender(thread), "Safety check");
193 assert(!fr->is_first_frame(), "Safety check");
194 *fr = fr->java_sender();
195 }
196 }
197 }
198 assert(fr->is_java_frame(), "Safety check");
199 return true;
200 }
201
202 frame os::get_sender_for_C_frame(frame* fr) {
203 if (*fr->sp() == 0) {
204 // fr is the last C frame
205 return frame(NULL, NULL);
206 }
207 return frame(fr->sender_sp(), fr->sender_pc());
208 }
209
210
211 frame os::current_frame() {
212 intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer());
213 // hack.
214 frame topframe(csp, (address)0x8);
215 // Return sender of sender of current topframe which hopefully
216 // both have pc != NULL.
217 frame tmp = os::get_sender_for_C_frame(&topframe);
218 return os::get_sender_for_C_frame(&tmp);
219 }
220
221 // Utility functions
222
223 extern "C" JNIEXPORT int
224 JVM_handle_linux_signal(int sig,
225 siginfo_t* info,
226 void* ucVoid,
227 int abort_if_unrecognized) {
228 ucontext_t* uc = (ucontext_t*) ucVoid;
229
230 Thread* t = Thread::current_or_null_safe();
231
232 SignalHandlerMark shm(t);
233
234 // Note: it's not uncommon that JNI code uses signal/sigset to install
235 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
236 // or have a SIGILL handler when detecting CPU type). When that happens,
237 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
238 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
239 // that do not require siginfo/ucontext first.
240
241 if (sig == SIGPIPE) {
242 if (os::Linux::chained_handler(sig, info, ucVoid)) {
243 return true;
244 } else {
245 // Ignoring SIGPIPE - see bugs 4229104
246 return true;
247 }
248 }
249
250 // Make the signal handler transaction-aware by checking the existence of a
251 // second (transactional) context with MSR TS bits active. If the signal is
252 // caught during a transaction, then just return to the HTM abort handler.
253 // Please refer to Linux kernel document powerpc/transactional_memory.txt,
254 // section "Signals".
255 if (uc && uc->uc_link) {
256 ucontext_t* second_uc = uc->uc_link;
257
258 // MSR TS bits are 29 and 30 (Power ISA, v2.07B, Book III-S, pp. 857-858,
259 // 3.2.1 "Machine State Register"), however note that ISA notation for bit
260 // numbering is MSB 0, so for normal bit numbering (LSB 0) they come to be
261 // bits 33 and 34. It's not related to endianness, just a notation matter.
262 if (second_uc->uc_mcontext.regs->msr & 0x600000000) {
263 if (TraceTraps) {
264 tty->print_cr("caught signal in transaction, "
265 "ignoring to jump to abort handler");
266 }
267 // Return control to the HTM abort handler.
268 return true;
269 }
270 }
271
272 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
273 if ((sig == SIGSEGV || sig == SIGBUS) && info != NULL && info->si_addr == g_assert_poison) {
274 handle_assert_poison_fault(ucVoid, info->si_addr);
275 return 1;
276 }
277 #endif
278
279 JavaThread* thread = NULL;
280 VMThread* vmthread = NULL;
281 if (os::Linux::signal_handlers_are_installed) {
282 if (t != NULL) {
283 if(t->is_Java_thread()) {
284 thread = (JavaThread*)t;
285 } else if(t->is_VM_thread()) {
286 vmthread = (VMThread *)t;
287 }
288 }
289 }
290
291 // Moved SafeFetch32 handling outside thread!=NULL conditional block to make
292 // it work if no associated JavaThread object exists.
293 if (uc) {
294 address const pc = os::Linux::ucontext_get_pc(uc);
295 if (pc && StubRoutines::is_safefetch_fault(pc)) {
296 os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
297 return true;
298 }
299 }
300
301 // decide if this trap can be handled by a stub
302 address stub = NULL;
303 address pc = NULL;
304
305 //%note os_trap_1
306 if (info != NULL && uc != NULL && thread != NULL) {
307 pc = (address) os::Linux::ucontext_get_pc(uc);
308
309 // Handle ALL stack overflow variations here
310 if (sig == SIGSEGV) {
311 // si_addr may not be valid due to a bug in the linux-ppc64 kernel (see
312 // comment below). Use get_stack_bang_address instead of si_addr.
313 // If SIGSEGV is caused due to a branch to an invalid address an
314 // "Instruction Storage" interruption is generated and 'pc' (NIP) already
315 // contains the invalid address. Otherwise, the SIGSEGV is caused due to
316 // load/store instruction trying to load/store from/to an invalid address
317 // and causing a "Data Storage" interruption, so we inspect the intruction
318 // in order to extract the faulty data addresss.
319 address addr;
320 if ((ucontext_get_trap(uc) & 0x0F00 /* no IRQ reply bits */) == 0x0400) {
321 // Instruction interruption
322 addr = pc;
323 } else {
324 // Data interruption (0x0300): extract faulty data address
325 addr = ((NativeInstruction*)pc)->get_stack_bang_address(uc);
326 }
327
328 // Check if fault address is within thread stack.
329 if (thread->on_local_stack(addr)) {
330 // stack overflow
331 if (thread->in_stack_yellow_reserved_zone(addr)) {
332 if (thread->thread_state() == _thread_in_Java) {
333 if (thread->in_stack_reserved_zone(addr)) {
334 frame fr;
335 if (os::Linux::get_frame_at_stack_banging_point(thread, uc, &fr)) {
336 assert(fr.is_java_frame(), "Must be a Javac frame");
337 frame activation =
338 SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
339 if (activation.sp() != NULL) {
340 thread->disable_stack_reserved_zone();
341 if (activation.is_interpreted_frame()) {
342 thread->set_reserved_stack_activation((address)activation.fp());
343 } else {
344 thread->set_reserved_stack_activation((address)activation.unextended_sp());
345 }
346 return 1;
347 }
348 }
349 }
350 // Throw a stack overflow exception.
351 // Guard pages will be reenabled while unwinding the stack.
352 thread->disable_stack_yellow_reserved_zone();
353 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
354 } else {
355 // Thread was in the vm or native code. Return and try to finish.
356 thread->disable_stack_yellow_reserved_zone();
357 return 1;
358 }
359 } else if (thread->in_stack_red_zone(addr)) {
360 // Fatal red zone violation. Disable the guard pages and fall through
361 // to handle_unexpected_exception way down below.
362 thread->disable_stack_red_zone();
363 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
364
365 // This is a likely cause, but hard to verify. Let's just print
366 // it as a hint.
367 tty->print_raw_cr("Please check if any of your loaded .so files has "
368 "enabled executable stack (see man page execstack(8))");
369 } else {
370 // Accessing stack address below sp may cause SEGV if current
371 // thread has MAP_GROWSDOWN stack. This should only happen when
372 // current thread was created by user code with MAP_GROWSDOWN flag
373 // and then attached to VM. See notes in os_linux.cpp.
374 if (thread->osthread()->expanding_stack() == 0) {
375 thread->osthread()->set_expanding_stack();
376 if (os::Linux::manually_expand_stack(thread, addr)) {
377 thread->osthread()->clear_expanding_stack();
378 return 1;
379 }
380 thread->osthread()->clear_expanding_stack();
381 } else {
382 fatal("recursive segv. expanding stack.");
383 }
384 }
385 }
386 }
387
388 if (thread->thread_state() == _thread_in_Java) {
389 // Java thread running in Java code => find exception handler if any
390 // a fault inside compiled code, the interpreter, or a stub
391
392 // A VM-related SIGILL may only occur if we are not in the zero page.
393 // On AIX, we get a SIGILL if we jump to 0x0 or to somewhere else
394 // in the zero page, because it is filled with 0x0. We ignore
395 // explicit SIGILLs in the zero page.
396 if (sig == SIGILL && (pc < (address) 0x200)) {
397 if (TraceTraps) {
398 tty->print_raw_cr("SIGILL happened inside zero page.");
399 }
400 goto report_and_die;
401 }
402
403 CodeBlob *cb = NULL;
404 // Handle signal from NativeJump::patch_verified_entry().
405 if (( TrapBasedNotEntrantChecks && sig == SIGTRAP && nativeInstruction_at(pc)->is_sigtrap_zombie_not_entrant()) ||
406 (!TrapBasedNotEntrantChecks && sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant())) {
407 if (TraceTraps) {
408 tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL");
409 }
410 stub = SharedRuntime::get_handle_wrong_method_stub();
411 }
412
413 else if (sig == ((SafepointMechanism::uses_thread_local_poll() && USE_POLL_BIT_ONLY) ? SIGTRAP : SIGSEGV) &&
414 // A linux-ppc64 kernel before 2.6.6 doesn't set si_addr on some segfaults
415 // in 64bit mode (cf. http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.6),
416 // especially when we try to read from the safepoint polling page. So the check
417 // (address)info->si_addr == os::get_standard_polling_page()
418 // doesn't work for us. We use:
419 ((NativeInstruction*)pc)->is_safepoint_poll() &&
420 CodeCache::contains((void*) pc) &&
421 ((cb = CodeCache::find_blob(pc)) != NULL) &&
422 cb->is_compiled()) {
423 if (TraceTraps) {
424 tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (%s)", p2i(pc),
425 (SafepointMechanism::uses_thread_local_poll() && USE_POLL_BIT_ONLY) ? "SIGTRAP" : "SIGSEGV");
426 }
427 stub = SharedRuntime::get_poll_stub(pc);
428 }
429
430 // SIGTRAP-based ic miss check in compiled code.
431 else if (sig == SIGTRAP && TrapBasedICMissChecks &&
432 nativeInstruction_at(pc)->is_sigtrap_ic_miss_check()) {
433 if (TraceTraps) {
434 tty->print_cr("trap: ic_miss_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
435 }
436 stub = SharedRuntime::get_ic_miss_stub();
437 }
438
439 // SIGTRAP-based implicit null check in compiled code.
440 else if (sig == SIGTRAP && TrapBasedNullChecks &&
441 nativeInstruction_at(pc)->is_sigtrap_null_check()) {
442 if (TraceTraps) {
443 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
444 }
445 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
446 }
447
448 // SIGSEGV-based implicit null check in compiled code.
449 else if (sig == SIGSEGV && ImplicitNullChecks &&
450 CodeCache::contains((void*) pc) &&
451 MacroAssembler::uses_implicit_null_check(info->si_addr)) {
452 if (TraceTraps) {
453 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
454 }
455 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
456 }
457
458 #ifdef COMPILER2
459 // SIGTRAP-based implicit range check in compiled code.
460 else if (sig == SIGTRAP && TrapBasedRangeChecks &&
461 nativeInstruction_at(pc)->is_sigtrap_range_check()) {
462 if (TraceTraps) {
463 tty->print_cr("trap: range_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
464 }
465 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
466 }
467 #endif
468 else if (sig == SIGBUS) {
469 // BugId 4454115: A read from a MappedByteBuffer can fault here if the
470 // underlying file has been truncated. Do not crash the VM in such a case.
471 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
472 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
473 if (nm != NULL && nm->has_unsafe_access()) {
474 address next_pc = pc + 4;
475 next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
476 os::Linux::ucontext_set_pc(uc, next_pc);
477 return true;
478 }
479 }
480 }
481
482 else { // thread->thread_state() != _thread_in_Java
483 if (sig == SIGILL && VM_Version::is_determine_features_test_running()) {
484 // SIGILL must be caused by VM_Version::determine_features().
485 *(int *)pc = 0; // patch instruction to 0 to indicate that it causes a SIGILL,
486 // flushing of icache is not necessary.
487 stub = pc + 4; // continue with next instruction.
488 }
489 else if (thread->thread_state() == _thread_in_vm &&
490 sig == SIGBUS && thread->doing_unsafe_access()) {
491 address next_pc = pc + 4;
492 next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
493 os::Linux::ucontext_set_pc(uc, pc + 4);
494 return true;
495 }
496 }
497 }
498
499 if (stub != NULL) {
500 // Save all thread context in case we need to restore it.
501 if (thread != NULL) thread->set_saved_exception_pc(pc);
502 os::Linux::ucontext_set_pc(uc, stub);
503 return true;
504 }
505
506 // signal-chaining
507 if (os::Linux::chained_handler(sig, info, ucVoid)) {
508 return true;
509 }
510
511 if (!abort_if_unrecognized) {
512 // caller wants another chance, so give it to him
513 return false;
514 }
515
516 if (pc == NULL && uc != NULL) {
517 pc = os::Linux::ucontext_get_pc(uc);
518 }
519
520 report_and_die:
521 // unmask current signal
522 sigset_t newset;
523 sigemptyset(&newset);
524 sigaddset(&newset, sig);
525 sigprocmask(SIG_UNBLOCK, &newset, NULL);
526
527 VMError::report_and_die(t, sig, pc, info, ucVoid);
528
529 ShouldNotReachHere();
530 return false;
531 }
532
533 void os::Linux::init_thread_fpu_state(void) {
534 // Disable FP exceptions.
535 __asm__ __volatile__ ("mtfsfi 6,0");
536 }
537
538 int os::Linux::get_fpu_control_word(void) {
539 // x86 has problems with FPU precision after pthread_cond_timedwait().
540 // nothing to do on ppc64.
541 return 0;
542 }
543
544 void os::Linux::set_fpu_control_word(int fpu_control) {
545 // x86 has problems with FPU precision after pthread_cond_timedwait().
546 // nothing to do on ppc64.
547 }
548
549 ////////////////////////////////////////////////////////////////////////////////
550 // thread stack
551
552 // Minimum usable stack sizes required to get to user code. Space for
553 // HotSpot guard pages is added later.
554 size_t os::Posix::_compiler_thread_min_stack_allowed = 64 * K;
555 size_t os::Posix::_java_thread_min_stack_allowed = 64 * K;
556 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K;
557
558 // Return default stack size for thr_type.
559 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
560 // Default stack size (compiler thread needs larger stack).
561 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1024 * K);
562 return s;
563 }
564
565 /////////////////////////////////////////////////////////////////////////////
566 // helper functions for fatal error handler
567
568 void os::print_context(outputStream *st, const void *context) {
569 if (context == NULL) return;
570
571 const ucontext_t* uc = (const ucontext_t*)context;
572
573 st->print_cr("Registers:");
574 st->print("pc =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->nip);
575 st->print("lr =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->link);
576 st->print("ctr=" INTPTR_FORMAT " ", uc->uc_mcontext.regs->ctr);
577 st->cr();
578 for (int i = 0; i < 32; i++) {
579 st->print("r%-2d=" INTPTR_FORMAT " ", i, uc->uc_mcontext.regs->gpr[i]);
580 if (i % 3 == 2) st->cr();
581 }
582 st->cr();
583 st->cr();
584
585 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
586 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp));
587 print_hex_dump(st, (address)sp, (address)(sp + 128), sizeof(intptr_t));
588 st->cr();
589
590 // Note: it may be unsafe to inspect memory near pc. For example, pc may
591 // point to garbage if entry point in an nmethod is corrupted. Leave
592 // this at the end, and hope for the best.
593 address pc = os::Linux::ucontext_get_pc(uc);
594 print_instructions(st, pc, /*instrsize=*/4);
595 st->cr();
596 }
597
598 void os::print_register_info(outputStream *st, const void *context) {
599 if (context == NULL) return;
600
601 const ucontext_t *uc = (const ucontext_t*)context;
602
603 st->print_cr("Register to memory mapping:");
604 st->cr();
605
606 st->print("pc ="); print_location(st, (intptr_t)uc->uc_mcontext.regs->nip);
607 st->print("lr ="); print_location(st, (intptr_t)uc->uc_mcontext.regs->link);
608 st->print("ctr ="); print_location(st, (intptr_t)uc->uc_mcontext.regs->ctr);
609 for (int i = 0; i < 32; i++) {
610 st->print("r%-2d=", i);
611 print_location(st, uc->uc_mcontext.regs->gpr[i]);
612 }
613 st->cr();
614 }
615
616 extern "C" {
617 int SpinPause() {
618 return 0;
619 }
620 }
621
622 #ifndef PRODUCT
623 void os::verify_stack_alignment() {
624 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
625 }
626 #endif
627
628 int os::extra_bang_size_in_bytes() {
629 // PPC does not require the additional stack bang.
630 return 0;
631 }