1 /*
2 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2012, 2019 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 if (info != NULL && uc != NULL && thread != NULL) {
306 pc = (address) os::Linux::ucontext_get_pc(uc);
307
308 // Handle ALL stack overflow variations here
309 if (sig == SIGSEGV) {
310 // si_addr may not be valid due to a bug in the linux-ppc64 kernel (see
311 // comment below). Use get_stack_bang_address instead of si_addr.
312 // If SIGSEGV is caused due to a branch to an invalid address an
313 // "Instruction Storage Interrupt" is generated and 'pc' (NIP) already
314 // contains the invalid address. Otherwise, the SIGSEGV is caused due to
315 // load/store instruction trying to load/store from/to an invalid address
316 // and causing a "Data Storage Interrupt", so we inspect the intruction
317 // in order to extract the faulty data addresss.
318 address addr;
319 if ((ucontext_get_trap(uc) & 0x0F00 /* no IRQ reply bits */) == 0x0400) {
320 // Instruction Storage Interrupt (ISI)
321 addr = pc;
322 } else {
323 // Data Storage Interrupt (DSI), i.e. 0x0300: extract faulty data address
324 addr = ((NativeInstruction*)pc)->get_stack_bang_address(uc);
325 }
326
327 // Check if fault address is within thread stack.
328 if (thread->on_local_stack(addr)) {
329 // stack overflow
330 if (thread->in_stack_yellow_reserved_zone(addr)) {
331 if (thread->thread_state() == _thread_in_Java) {
332 if (thread->in_stack_reserved_zone(addr)) {
333 frame fr;
334 if (os::Linux::get_frame_at_stack_banging_point(thread, uc, &fr)) {
335 assert(fr.is_java_frame(), "Must be a Javac frame");
336 frame activation =
337 SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
338 if (activation.sp() != NULL) {
339 thread->disable_stack_reserved_zone();
340 if (activation.is_interpreted_frame()) {
341 thread->set_reserved_stack_activation((address)activation.fp());
342 } else {
343 thread->set_reserved_stack_activation((address)activation.unextended_sp());
344 }
345 return 1;
346 }
347 }
348 }
349 // Throw a stack overflow exception.
350 // Guard pages will be reenabled while unwinding the stack.
351 thread->disable_stack_yellow_reserved_zone();
352 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
353 } else {
354 // Thread was in the vm or native code. Return and try to finish.
355 thread->disable_stack_yellow_reserved_zone();
356 return 1;
357 }
358 } else if (thread->in_stack_red_zone(addr)) {
359 // Fatal red zone violation. Disable the guard pages and fall through
360 // to handle_unexpected_exception way down below.
361 thread->disable_stack_red_zone();
362 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
363
364 // This is a likely cause, but hard to verify. Let's just print
365 // it as a hint.
366 tty->print_raw_cr("Please check if any of your loaded .so files has "
367 "enabled executable stack (see man page execstack(8))");
368 } else {
369 // Accessing stack address below sp may cause SEGV if current
370 // thread has MAP_GROWSDOWN stack. This should only happen when
371 // current thread was created by user code with MAP_GROWSDOWN flag
372 // and then attached to VM. See notes in os_linux.cpp.
373 if (thread->osthread()->expanding_stack() == 0) {
374 thread->osthread()->set_expanding_stack();
375 if (os::Linux::manually_expand_stack(thread, addr)) {
376 thread->osthread()->clear_expanding_stack();
377 return 1;
378 }
379 thread->osthread()->clear_expanding_stack();
380 } else {
381 fatal("recursive segv. expanding stack.");
382 }
383 }
384 }
385 }
386
387 if (thread->thread_state() == _thread_in_Java) {
388 // Java thread running in Java code => find exception handler if any
389 // a fault inside compiled code, the interpreter, or a stub
390
391 // A VM-related SIGILL may only occur if we are not in the zero page.
392 // On AIX, we get a SIGILL if we jump to 0x0 or to somewhere else
393 // in the zero page, because it is filled with 0x0. We ignore
394 // explicit SIGILLs in the zero page.
395 if (sig == SIGILL && (pc < (address) 0x200)) {
396 if (TraceTraps) {
397 tty->print_raw_cr("SIGILL happened inside zero page.");
398 }
399 goto report_and_die;
400 }
401
402 CodeBlob *cb = NULL;
403 // Handle signal from NativeJump::patch_verified_entry().
404 if (( TrapBasedNotEntrantChecks && sig == SIGTRAP && nativeInstruction_at(pc)->is_sigtrap_zombie_not_entrant()) ||
405 (!TrapBasedNotEntrantChecks && sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant())) {
406 if (TraceTraps) {
407 tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL");
408 }
409 stub = SharedRuntime::get_handle_wrong_method_stub();
410 }
411
412 else if (sig == ((SafepointMechanism::uses_thread_local_poll() && USE_POLL_BIT_ONLY) ? SIGTRAP : SIGSEGV) &&
413 // A linux-ppc64 kernel before 2.6.6 doesn't set si_addr on some segfaults
414 // in 64bit mode (cf. http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.6),
415 // especially when we try to read from the safepoint polling page. So the check
416 // (address)info->si_addr == os::get_standard_polling_page()
417 // doesn't work for us. We use:
418 ((NativeInstruction*)pc)->is_safepoint_poll() &&
419 CodeCache::contains((void*) pc) &&
420 ((cb = CodeCache::find_blob(pc)) != NULL) &&
421 cb->is_compiled()) {
422 if (TraceTraps) {
423 tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (%s)", p2i(pc),
424 (SafepointMechanism::uses_thread_local_poll() && USE_POLL_BIT_ONLY) ? "SIGTRAP" : "SIGSEGV");
425 }
426 stub = SharedRuntime::get_poll_stub(pc);
427 }
428
429 // SIGTRAP-based ic miss check in compiled code.
430 else if (sig == SIGTRAP && TrapBasedICMissChecks &&
431 nativeInstruction_at(pc)->is_sigtrap_ic_miss_check()) {
432 if (TraceTraps) {
433 tty->print_cr("trap: ic_miss_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
434 }
435 stub = SharedRuntime::get_ic_miss_stub();
436 }
437
438 // SIGTRAP-based implicit null check in compiled code.
439 else if (sig == SIGTRAP && TrapBasedNullChecks &&
440 nativeInstruction_at(pc)->is_sigtrap_null_check()) {
441 if (TraceTraps) {
442 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
443 }
444 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
445 }
446
447 // SIGSEGV-based implicit null check in compiled code.
448 else if (sig == SIGSEGV && ImplicitNullChecks &&
449 CodeCache::contains((void*) pc) &&
450 MacroAssembler::uses_implicit_null_check(info->si_addr)) {
451 if (TraceTraps) {
452 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
453 }
454 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
455 }
456
457 #ifdef COMPILER2
458 // SIGTRAP-based implicit range check in compiled code.
459 else if (sig == SIGTRAP && TrapBasedRangeChecks &&
460 nativeInstruction_at(pc)->is_sigtrap_range_check()) {
461 if (TraceTraps) {
462 tty->print_cr("trap: range_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
463 }
464 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
465 }
466 #endif
467 else if (sig == SIGBUS) {
468 // BugId 4454115: A read from a MappedByteBuffer can fault here if the
469 // underlying file has been truncated. Do not crash the VM in such a case.
470 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
471 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
472 if (nm != NULL && nm->has_unsafe_access()) {
473 address next_pc = pc + 4;
474 next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
475 os::Linux::ucontext_set_pc(uc, next_pc);
476 return true;
477 }
478 }
479 }
480
481 else { // thread->thread_state() != _thread_in_Java
482 if (sig == SIGILL && VM_Version::is_determine_features_test_running()) {
483 // SIGILL must be caused by VM_Version::determine_features().
484 *(int *)pc = 0; // patch instruction to 0 to indicate that it causes a SIGILL,
485 // flushing of icache is not necessary.
486 stub = pc + 4; // continue with next instruction.
487 }
488 else if (thread->thread_state() == _thread_in_vm &&
489 sig == SIGBUS && thread->doing_unsafe_access()) {
490 address next_pc = pc + 4;
491 next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
492 os::Linux::ucontext_set_pc(uc, pc + 4);
493 return true;
494 }
495 }
496 }
497
498 if (stub != NULL) {
499 // Save all thread context in case we need to restore it.
500 if (thread != NULL) thread->set_saved_exception_pc(pc);
501 os::Linux::ucontext_set_pc(uc, stub);
502 return true;
503 }
504
505 // signal-chaining
506 if (os::Linux::chained_handler(sig, info, ucVoid)) {
507 return true;
508 }
509
510 if (!abort_if_unrecognized) {
511 // caller wants another chance, so give it to him
512 return false;
513 }
514
515 if (pc == NULL && uc != NULL) {
516 pc = os::Linux::ucontext_get_pc(uc);
517 }
518
519 report_and_die:
520 // unmask current signal
521 sigset_t newset;
522 sigemptyset(&newset);
523 sigaddset(&newset, sig);
524 sigprocmask(SIG_UNBLOCK, &newset, NULL);
525
526 VMError::report_and_die(t, sig, pc, info, ucVoid);
527
528 ShouldNotReachHere();
529 return false;
530 }
531
532 void os::Linux::init_thread_fpu_state(void) {
533 // Disable FP exceptions.
534 __asm__ __volatile__ ("mtfsfi 6,0");
535 }
536
537 int os::Linux::get_fpu_control_word(void) {
538 // x86 has problems with FPU precision after pthread_cond_timedwait().
539 // nothing to do on ppc64.
540 return 0;
541 }
542
543 void os::Linux::set_fpu_control_word(int fpu_control) {
544 // x86 has problems with FPU precision after pthread_cond_timedwait().
545 // nothing to do on ppc64.
546 }
547
548 ////////////////////////////////////////////////////////////////////////////////
549 // thread stack
550
551 // Minimum usable stack sizes required to get to user code. Space for
552 // HotSpot guard pages is added later.
553 size_t os::Posix::_compiler_thread_min_stack_allowed = 64 * K;
554 size_t os::Posix::_java_thread_min_stack_allowed = 64 * K;
555 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K;
556
557 // Return default stack size for thr_type.
558 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
559 // Default stack size (compiler thread needs larger stack).
560 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1024 * K);
561 return s;
562 }
563
564 /////////////////////////////////////////////////////////////////////////////
565 // helper functions for fatal error handler
566
567 void os::print_context(outputStream *st, const void *context) {
568 if (context == NULL) return;
569
570 const ucontext_t* uc = (const ucontext_t*)context;
571
572 st->print_cr("Registers:");
573 st->print("pc =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->nip);
574 st->print("lr =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->link);
575 st->print("ctr=" INTPTR_FORMAT " ", uc->uc_mcontext.regs->ctr);
576 st->cr();
577 for (int i = 0; i < 32; i++) {
578 st->print("r%-2d=" INTPTR_FORMAT " ", i, uc->uc_mcontext.regs->gpr[i]);
579 if (i % 3 == 2) st->cr();
580 }
581 st->cr();
582 st->cr();
583
584 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
585 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp));
586 print_hex_dump(st, (address)sp, (address)(sp + 128), sizeof(intptr_t));
587 st->cr();
588
589 // Note: it may be unsafe to inspect memory near pc. For example, pc may
590 // point to garbage if entry point in an nmethod is corrupted. Leave
591 // this at the end, and hope for the best.
592 address pc = os::Linux::ucontext_get_pc(uc);
593 print_instructions(st, pc, /*instrsize=*/4);
594 st->cr();
595 }
596
597 void os::print_register_info(outputStream *st, const void *context) {
598 if (context == NULL) return;
599
600 const ucontext_t *uc = (const ucontext_t*)context;
601
602 st->print_cr("Register to memory mapping:");
603 st->cr();
604
605 st->print("pc ="); print_location(st, (intptr_t)uc->uc_mcontext.regs->nip);
606 st->print("lr ="); print_location(st, (intptr_t)uc->uc_mcontext.regs->link);
607 st->print("ctr ="); print_location(st, (intptr_t)uc->uc_mcontext.regs->ctr);
608 for (int i = 0; i < 32; i++) {
609 st->print("r%-2d=", i);
610 print_location(st, uc->uc_mcontext.regs->gpr[i]);
611 }
612 st->cr();
613 }
614
615 extern "C" {
616 int SpinPause() {
617 return 0;
618 }
619 }
620
621 #ifndef PRODUCT
622 void os::verify_stack_alignment() {
623 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
624 }
625 #endif
626
627 int os::extra_bang_size_in_bytes() {
628 // PPC does not require the additional stack bang.
629 return 0;
630 }