1 /*
2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2012, 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 // no precompiled headers
27 #include "asm/assembler.inline.hpp"
28 #include "classfile/classLoader.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "code/codeCache.hpp"
32 #include "code/icBuffer.hpp"
33 #include "code/vtableStubs.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "jvm_linux.h"
36 #include "memory/allocation.inline.hpp"
37 #include "mutex_linux.inline.hpp"
38 #include "nativeInst_ppc.hpp"
39 #include "os_share_linux.hpp"
40 #include "prims/jniFastGetField.hpp"
41 #include "prims/jvm.h"
42 #include "prims/jvm_misc.hpp"
43 #include "runtime/arguments.hpp"
44 #include "runtime/extendedPC.hpp"
45 #include "runtime/frame.inline.hpp"
46 #include "runtime/interfaceSupport.hpp"
47 #include "runtime/java.hpp"
48 #include "runtime/javaCalls.hpp"
49 #include "runtime/mutexLocker.hpp"
50 #include "runtime/osThread.hpp"
51 #include "runtime/sharedRuntime.hpp"
52 #include "runtime/stubRoutines.hpp"
53 #include "runtime/thread.inline.hpp"
54 #include "runtime/timer.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 void os::initialize_thread(Thread *thread) { }
98
99 // Frame information (pc, sp, fp) retrieved via ucontext
100 // always looks like a C-frame according to the frame
101 // conventions in frame_ppc64.hpp.
102 address os::Linux::ucontext_get_pc(const ucontext_t * uc) {
103 // On powerpc64, ucontext_t is not selfcontained but contains
104 // a pointer to an optional substructure (mcontext_t.regs) containing the volatile
105 // registers - NIP, among others.
106 // This substructure may or may not be there depending where uc came from:
107 // - if uc was handed over as the argument to a sigaction handler, a pointer to the
108 // substructure was provided by the kernel when calling the signal handler, and
109 // regs->nip can be accessed.
110 // - if uc was filled by getcontext(), it is undefined - getcontext() does not fill
111 // it because the volatile registers are not needed to make setcontext() work.
112 // Hopefully it was zero'd out beforehand.
113 guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_get_pc in sigaction context");
114 return (address)uc->uc_mcontext.regs->nip;
115 }
116
117 // modify PC in ucontext.
118 // Note: Only use this for an ucontext handed down to a signal handler. See comment
119 // in ucontext_get_pc.
120 void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) {
121 guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_set_pc in sigaction context");
122 uc->uc_mcontext.regs->nip = (unsigned long)pc;
123 }
124
125 intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) {
126 return (intptr_t*)uc->uc_mcontext.regs->gpr[1/*REG_SP*/];
127 }
128
129 intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) {
130 return NULL;
131 }
132
133 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
134 intptr_t** ret_sp, intptr_t** ret_fp) {
135
136 ExtendedPC epc;
137 const ucontext_t* uc = (const ucontext_t*)ucVoid;
138
139 if (uc != NULL) {
140 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
141 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc);
142 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc);
143 } else {
144 // construct empty ExtendedPC for return value checking
145 epc = ExtendedPC(NULL);
146 if (ret_sp) *ret_sp = (intptr_t *)NULL;
147 if (ret_fp) *ret_fp = (intptr_t *)NULL;
148 }
149
150 return epc;
151 }
152
153 frame os::fetch_frame_from_context(const void* ucVoid) {
154 intptr_t* sp;
155 intptr_t* fp;
156 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
157 return frame(sp, epc.pc());
158 }
159
160 bool os::Linux::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
161 address pc = (address) os::Linux::ucontext_get_pc(uc);
162 if (Interpreter::contains(pc)) {
163 // Interpreter performs stack banging after the fixed frame header has
164 // been generated while the compilers perform it before. To maintain
165 // semantic consistency between interpreted and compiled frames, the
166 // method returns the Java sender of the current frame.
167 *fr = os::fetch_frame_from_context(uc);
168 if (!fr->is_first_java_frame()) {
169 assert(fr->safe_for_sender(thread), "Safety check");
170 *fr = fr->java_sender();
171 }
172 } else {
173 // More complex code with compiled code.
174 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
175 CodeBlob* cb = CodeCache::find_blob(pc);
176 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
177 // Not sure where the pc points to, fallback to default
178 // stack overflow handling. In compiled code, we bang before
179 // the frame is complete.
180 return false;
181 } else {
182 intptr_t* fp = os::Linux::ucontext_get_fp(uc);
183 intptr_t* sp = os::Linux::ucontext_get_sp(uc);
184 *fr = frame(sp, (address)*sp);
185 if (!fr->is_java_frame()) {
186 assert(fr->safe_for_sender(thread), "Safety check");
187 assert(!fr->is_first_frame(), "Safety check");
188 *fr = fr->java_sender();
189 }
190 }
191 }
192 assert(fr->is_java_frame(), "Safety check");
193 return true;
194 }
195
196 frame os::get_sender_for_C_frame(frame* fr) {
197 if (*fr->sp() == 0) {
198 // fr is the last C frame
199 return frame(NULL, NULL);
200 }
201 return frame(fr->sender_sp(), fr->sender_pc());
202 }
203
204
205 frame os::current_frame() {
206 intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer());
207 // hack.
208 frame topframe(csp, (address)0x8);
209 // return sender of current topframe which hopefully has pc != NULL.
210 return os::get_sender_for_C_frame(&topframe);
211 }
212
213 // Utility functions
214
215 extern "C" JNIEXPORT int
216 JVM_handle_linux_signal(int sig,
217 siginfo_t* info,
218 void* ucVoid,
219 int abort_if_unrecognized) {
220 ucontext_t* uc = (ucontext_t*) ucVoid;
221
222 Thread* t = Thread::current_or_null_safe();
223
224 SignalHandlerMark shm(t);
225
226 // Note: it's not uncommon that JNI code uses signal/sigset to install
227 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
228 // or have a SIGILL handler when detecting CPU type). When that happens,
229 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
230 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
231 // that do not require siginfo/ucontext first.
232
233 if (sig == SIGPIPE) {
234 if (os::Linux::chained_handler(sig, info, ucVoid)) {
235 return true;
236 } else {
237 // Ignoring SIGPIPE - see bugs 4229104
238 return true;
239 }
240 }
241
242 JavaThread* thread = NULL;
243 VMThread* vmthread = NULL;
244 if (os::Linux::signal_handlers_are_installed) {
245 if (t != NULL) {
246 if(t->is_Java_thread()) {
247 thread = (JavaThread*)t;
248 } else if(t->is_VM_thread()) {
249 vmthread = (VMThread *)t;
250 }
251 }
252 }
253
254 // Moved SafeFetch32 handling outside thread!=NULL conditional block to make
255 // it work if no associated JavaThread object exists.
256 if (uc) {
257 address const pc = os::Linux::ucontext_get_pc(uc);
258 if (pc && StubRoutines::is_safefetch_fault(pc)) {
259 os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
260 return true;
261 }
262 }
263
264 // decide if this trap can be handled by a stub
265 address stub = NULL;
266 address pc = NULL;
267
268 //%note os_trap_1
269 if (info != NULL && uc != NULL && thread != NULL) {
270 pc = (address) os::Linux::ucontext_get_pc(uc);
271
272 // Handle ALL stack overflow variations here
273 if (sig == SIGSEGV) {
274 // Si_addr may not be valid due to a bug in the linux-ppc64 kernel (see
275 // comment below). Use get_stack_bang_address instead of si_addr.
276 address addr = ((NativeInstruction*)pc)->get_stack_bang_address(uc);
277
278 // Check if fault address is within thread stack.
279 if (thread->on_local_stack(addr)) {
280 // stack overflow
281 if (thread->in_stack_yellow_reserved_zone(addr)) {
282 if (thread->thread_state() == _thread_in_Java) {
283 if (thread->in_stack_reserved_zone(addr)) {
284 frame fr;
285 if (os::Linux::get_frame_at_stack_banging_point(thread, uc, &fr)) {
286 assert(fr.is_java_frame(), "Must be a Javac frame");
287 frame activation =
288 SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
289 if (activation.sp() != NULL) {
290 thread->disable_stack_reserved_zone();
291 if (activation.is_interpreted_frame()) {
292 thread->set_reserved_stack_activation((address)activation.fp());
293 } else {
294 thread->set_reserved_stack_activation((address)activation.unextended_sp());
295 }
296 return 1;
297 }
298 }
299 }
300 // Throw a stack overflow exception.
301 // Guard pages will be reenabled while unwinding the stack.
302 thread->disable_stack_yellow_reserved_zone();
303 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
304 } else {
305 // Thread was in the vm or native code. Return and try to finish.
306 thread->disable_stack_yellow_reserved_zone();
307 return 1;
308 }
309 } else if (thread->in_stack_red_zone(addr)) {
310 // Fatal red zone violation. Disable the guard pages and fall through
311 // to handle_unexpected_exception way down below.
312 thread->disable_stack_red_zone();
313 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
314
315 // This is a likely cause, but hard to verify. Let's just print
316 // it as a hint.
317 tty->print_raw_cr("Please check if any of your loaded .so files has "
318 "enabled executable stack (see man page execstack(8))");
319 } else {
320 // Accessing stack address below sp may cause SEGV if current
321 // thread has MAP_GROWSDOWN stack. This should only happen when
322 // current thread was created by user code with MAP_GROWSDOWN flag
323 // and then attached to VM. See notes in os_linux.cpp.
324 if (thread->osthread()->expanding_stack() == 0) {
325 thread->osthread()->set_expanding_stack();
326 if (os::Linux::manually_expand_stack(thread, addr)) {
327 thread->osthread()->clear_expanding_stack();
328 return 1;
329 }
330 thread->osthread()->clear_expanding_stack();
331 } else {
332 fatal("recursive segv. expanding stack.");
333 }
334 }
335 }
336 }
337
338 if (thread->thread_state() == _thread_in_Java) {
339 // Java thread running in Java code => find exception handler if any
340 // a fault inside compiled code, the interpreter, or a stub
341
342 // A VM-related SIGILL may only occur if we are not in the zero page.
343 // On AIX, we get a SIGILL if we jump to 0x0 or to somewhere else
344 // in the zero page, because it is filled with 0x0. We ignore
345 // explicit SIGILLs in the zero page.
346 if (sig == SIGILL && (pc < (address) 0x200)) {
347 if (TraceTraps) {
348 tty->print_raw_cr("SIGILL happened inside zero page.");
349 }
350 goto report_and_die;
351 }
352
353 CodeBlob *cb = NULL;
354 // Handle signal from NativeJump::patch_verified_entry().
355 if (( TrapBasedNotEntrantChecks && sig == SIGTRAP && nativeInstruction_at(pc)->is_sigtrap_zombie_not_entrant()) ||
356 (!TrapBasedNotEntrantChecks && sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant())) {
357 if (TraceTraps) {
358 tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL");
359 }
360 stub = SharedRuntime::get_handle_wrong_method_stub();
361 }
362
363 else if (sig == SIGSEGV &&
364 // A linux-ppc64 kernel before 2.6.6 doesn't set si_addr on some segfaults
365 // in 64bit mode (cf. http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.6),
366 // especially when we try to read from the safepoint polling page. So the check
367 // (address)info->si_addr == os::get_standard_polling_page()
368 // doesn't work for us. We use:
369 ((NativeInstruction*)pc)->is_safepoint_poll() &&
370 CodeCache::contains((void*) pc) &&
371 ((cb = CodeCache::find_blob(pc)) != NULL) &&
372 cb->is_compiled()) {
373 if (TraceTraps) {
374 tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
375 }
376 stub = SharedRuntime::get_poll_stub(pc);
377 }
378
379 // SIGTRAP-based ic miss check in compiled code.
380 else if (sig == SIGTRAP && TrapBasedICMissChecks &&
381 nativeInstruction_at(pc)->is_sigtrap_ic_miss_check()) {
382 if (TraceTraps) {
383 tty->print_cr("trap: ic_miss_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
384 }
385 stub = SharedRuntime::get_ic_miss_stub();
386 }
387
388 // SIGTRAP-based implicit null check in compiled code.
389 else if (sig == SIGTRAP && TrapBasedNullChecks &&
390 nativeInstruction_at(pc)->is_sigtrap_null_check()) {
391 if (TraceTraps) {
392 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
393 }
394 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
395 }
396
397 // SIGSEGV-based implicit null check in compiled code.
398 else if (sig == SIGSEGV && ImplicitNullChecks &&
399 CodeCache::contains((void*) pc) &&
400 !MacroAssembler::needs_explicit_null_check((intptr_t) info->si_addr)) {
401 if (TraceTraps) {
402 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
403 }
404 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
405 }
406
407 #ifdef COMPILER2
408 // SIGTRAP-based implicit range check in compiled code.
409 else if (sig == SIGTRAP && TrapBasedRangeChecks &&
410 nativeInstruction_at(pc)->is_sigtrap_range_check()) {
411 if (TraceTraps) {
412 tty->print_cr("trap: range_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
413 }
414 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
415 }
416 #endif
417 else if (sig == SIGBUS) {
418 // BugId 4454115: A read from a MappedByteBuffer can fault here if the
419 // underlying file has been truncated. Do not crash the VM in such a case.
420 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
421 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
422 if (nm != NULL && nm->has_unsafe_access()) {
423 address next_pc = pc + 4;
424 next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
425 os::Linux::ucontext_set_pc(uc, next_pc);
426 return true;
427 }
428 }
429 }
430
431 else { // thread->thread_state() != _thread_in_Java
432 if (sig == SIGILL && VM_Version::is_determine_features_test_running()) {
433 // SIGILL must be caused by VM_Version::determine_features().
434 *(int *)pc = 0; // patch instruction to 0 to indicate that it causes a SIGILL,
435 // flushing of icache is not necessary.
436 stub = pc + 4; // continue with next instruction.
437 }
438 else if (thread->thread_state() == _thread_in_vm &&
439 sig == SIGBUS && thread->doing_unsafe_access()) {
440 address next_pc = pc + 4;
441 next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
442 os::Linux::ucontext_set_pc(uc, pc + 4);
443 return true;
444 }
445 }
446
447 // Check to see if we caught the safepoint code in the
448 // process of write protecting the memory serialization page.
449 // It write enables the page immediately after protecting it
450 // so we can just return to retry the write.
451 if ((sig == SIGSEGV) &&
452 // Si_addr may not be valid due to a bug in the linux-ppc64 kernel (see comment above).
453 // Use is_memory_serialization instead of si_addr.
454 ((NativeInstruction*)pc)->is_memory_serialization(thread, ucVoid)) {
455 // Synchronization problem in the pseudo memory barrier code (bug id 6546278)
456 // Block current thread until the memory serialize page permission restored.
457 os::block_on_serialize_page_trap();
458 return true;
459 }
460 }
461
462 if (stub != NULL) {
463 // Save all thread context in case we need to restore it.
464 if (thread != NULL) thread->set_saved_exception_pc(pc);
465 os::Linux::ucontext_set_pc(uc, stub);
466 return true;
467 }
468
469 // signal-chaining
470 if (os::Linux::chained_handler(sig, info, ucVoid)) {
471 return true;
472 }
473
474 if (!abort_if_unrecognized) {
475 // caller wants another chance, so give it to him
476 return false;
477 }
478
479 if (pc == NULL && uc != NULL) {
480 pc = os::Linux::ucontext_get_pc(uc);
481 }
482
483 report_and_die:
484 // unmask current signal
485 sigset_t newset;
486 sigemptyset(&newset);
487 sigaddset(&newset, sig);
488 sigprocmask(SIG_UNBLOCK, &newset, NULL);
489
490 VMError::report_and_die(t, sig, pc, info, ucVoid);
491
492 ShouldNotReachHere();
493 return false;
494 }
495
496 void os::Linux::init_thread_fpu_state(void) {
497 // Disable FP exceptions.
498 __asm__ __volatile__ ("mtfsfi 6,0");
499 }
500
501 int os::Linux::get_fpu_control_word(void) {
502 // x86 has problems with FPU precision after pthread_cond_timedwait().
503 // nothing to do on ppc64.
504 return 0;
505 }
506
507 void os::Linux::set_fpu_control_word(int fpu_control) {
508 // x86 has problems with FPU precision after pthread_cond_timedwait().
509 // nothing to do on ppc64.
510 }
511
512 ////////////////////////////////////////////////////////////////////////////////
513 // thread stack
514
515 size_t os::Linux::min_stack_allowed = 128*K;
516
517 // return default stack size for thr_type
518 size_t os::Linux::default_stack_size(os::ThreadType thr_type) {
519 // default stack size (compiler thread needs larger stack)
520 // Notice that the setting for compiler threads here have no impact
521 // because of the strange 'fallback logic' in os::create_thread().
522 // Better set CompilerThreadStackSize in globals_<os_cpu>.hpp if you want to
523 // specify a different stack size for compiler threads!
524 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1024 * K);
525 return s;
526 }
527
528 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
529 return 2 * page_size();
530 }
531
532 // Java thread:
533 //
534 // Low memory addresses
535 // +------------------------+
536 // | |\ JavaThread created by VM does not have glibc
537 // | glibc guard page | - guard, attached Java thread usually has
538 // | |/ 1 page glibc guard.
539 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
540 // | |\
541 // | HotSpot Guard Pages | - red and yellow pages
542 // | |/
543 // +------------------------+ JavaThread::stack_yellow_zone_base()
544 // | |\
545 // | Normal Stack | -
546 // | |/
547 // P2 +------------------------+ Thread::stack_base()
548 //
549 // Non-Java thread:
550 //
551 // Low memory addresses
552 // +------------------------+
553 // | |\
554 // | glibc guard page | - usually 1 page
555 // | |/
556 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
557 // | |\
558 // | Normal Stack | -
559 // | |/
560 // P2 +------------------------+ Thread::stack_base()
561 //
562 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
563 // pthread_attr_getstack()
564
565 static void current_stack_region(address * bottom, size_t * size) {
566 if (os::Linux::is_initial_thread()) {
567 // initial thread needs special handling because pthread_getattr_np()
568 // may return bogus value.
569 *bottom = os::Linux::initial_thread_stack_bottom();
570 *size = os::Linux::initial_thread_stack_size();
571 } else {
572 pthread_attr_t attr;
573
574 int rslt = pthread_getattr_np(pthread_self(), &attr);
575
576 // JVM needs to know exact stack location, abort if it fails
577 if (rslt != 0) {
578 if (rslt == ENOMEM) {
579 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
580 } else {
581 fatal("pthread_getattr_np failed with errno = %d", rslt);
582 }
583 }
584
585 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
586 fatal("Can not locate current stack attributes!");
587 }
588
589 pthread_attr_destroy(&attr);
590
591 }
592 assert(os::current_stack_pointer() >= *bottom &&
593 os::current_stack_pointer() < *bottom + *size, "just checking");
594 }
595
596 address os::current_stack_base() {
597 address bottom;
598 size_t size;
599 current_stack_region(&bottom, &size);
600 return (bottom + size);
601 }
602
603 size_t os::current_stack_size() {
604 // stack size includes normal stack and HotSpot guard pages
605 address bottom;
606 size_t size;
607 current_stack_region(&bottom, &size);
608 return size;
609 }
610
611 /////////////////////////////////////////////////////////////////////////////
612 // helper functions for fatal error handler
613
614 void os::print_context(outputStream *st, const void *context) {
615 if (context == NULL) return;
616
617 const ucontext_t* uc = (const ucontext_t*)context;
618
619 st->print_cr("Registers:");
620 st->print("pc =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->nip);
621 st->print("lr =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->link);
622 st->print("ctr=" INTPTR_FORMAT " ", uc->uc_mcontext.regs->ctr);
623 st->cr();
624 for (int i = 0; i < 32; i++) {
625 st->print("r%-2d=" INTPTR_FORMAT " ", i, uc->uc_mcontext.regs->gpr[i]);
626 if (i % 3 == 2) st->cr();
627 }
628 st->cr();
629 st->cr();
630
631 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
632 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp));
633 print_hex_dump(st, (address)sp, (address)(sp + 128), sizeof(intptr_t));
634 st->cr();
635
636 // Note: it may be unsafe to inspect memory near pc. For example, pc may
637 // point to garbage if entry point in an nmethod is corrupted. Leave
638 // this at the end, and hope for the best.
639 address pc = os::Linux::ucontext_get_pc(uc);
640 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc));
641 print_hex_dump(st, pc - 64, pc + 64, /*instrsize=*/4);
642 st->cr();
643 }
644
645 void os::print_register_info(outputStream *st, const void *context) {
646 if (context == NULL) return;
647
648 const ucontext_t *uc = (const ucontext_t*)context;
649
650 st->print_cr("Register to memory mapping:");
651 st->cr();
652
653 // this is only for the "general purpose" registers
654 for (int i = 0; i < 32; i++) {
655 st->print("r%-2d=", i);
656 print_location(st, uc->uc_mcontext.regs->gpr[i]);
657 }
658 st->cr();
659 }
660
661 extern "C" {
662 int SpinPause() {
663 return 0;
664 }
665 }
666
667 #ifndef PRODUCT
668 void os::verify_stack_alignment() {
669 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
670 }
671 #endif
672
673 int os::extra_bang_size_in_bytes() {
674 // PPC does not require the additional stack bang.
675 return 0;
676 }