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 "nativeInst_ppc.hpp"
38 #include "os_share_linux.hpp"
39 #include "prims/jniFastGetField.hpp"
40 #include "prims/jvm.h"
41 #include "prims/jvm_misc.hpp"
42 #include "runtime/arguments.hpp"
43 #include "runtime/extendedPC.hpp"
44 #include "runtime/frame.inline.hpp"
45 #include "runtime/interfaceSupport.hpp"
46 #include "runtime/java.hpp"
47 #include "runtime/javaCalls.hpp"
48 #include "runtime/mutexLocker.hpp"
49 #include "runtime/osThread.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/events.hpp"
55 #include "utilities/vmError.hpp"
56
57 // put OS-includes here
58 # include <sys/types.h>
59 # include <sys/mman.h>
60 # include <pthread.h>
61 # include <signal.h>
62 # include <errno.h>
63 # include <dlfcn.h>
64 # include <stdlib.h>
65 # include <stdio.h>
66 # include <unistd.h>
67 # include <sys/resource.h>
68 # include <pthread.h>
69 # include <sys/stat.h>
70 # include <sys/time.h>
71 # include <sys/utsname.h>
72 # include <sys/socket.h>
73 # include <sys/wait.h>
74 # include <pwd.h>
75 # include <poll.h>
76 # include <ucontext.h>
77
78
79 address os::current_stack_pointer() {
80 intptr_t* csp;
81
82 // inline assembly `mr regno(csp), R1_SP':
83 __asm__ __volatile__ ("mr %0, 1":"=r"(csp):);
84
85 return (address) csp;
86 }
87
88 char* os::non_memory_address_word() {
89 // Must never look like an address returned by reserve_memory,
90 // even in its subfields (as defined by the CPU immediate fields,
91 // if the CPU splits constants across multiple instructions).
92
93 return (char*) -1;
94 }
95
96 void os::initialize_thread(Thread *thread) { }
97
98 // Frame information (pc, sp, fp) retrieved via ucontext
99 // always looks like a C-frame according to the frame
100 // conventions in frame_ppc64.hpp.
101 address os::Linux::ucontext_get_pc(const ucontext_t * uc) {
102 // On powerpc64, ucontext_t is not selfcontained but contains
103 // a pointer to an optional substructure (mcontext_t.regs) containing the volatile
104 // registers - NIP, among others.
105 // This substructure may or may not be there depending where uc came from:
106 // - if uc was handed over as the argument to a sigaction handler, a pointer to the
107 // substructure was provided by the kernel when calling the signal handler, and
108 // regs->nip can be accessed.
109 // - if uc was filled by getcontext(), it is undefined - getcontext() does not fill
110 // it because the volatile registers are not needed to make setcontext() work.
111 // Hopefully it was zero'd out beforehand.
112 guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_get_pc in sigaction context");
113 return (address)uc->uc_mcontext.regs->nip;
114 }
115
116 // modify PC in ucontext.
117 // Note: Only use this for an ucontext handed down to a signal handler. See comment
118 // in ucontext_get_pc.
119 void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) {
120 guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_set_pc in sigaction context");
121 uc->uc_mcontext.regs->nip = (unsigned long)pc;
122 }
123
124 intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) {
125 return (intptr_t*)uc->uc_mcontext.regs->gpr[1/*REG_SP*/];
126 }
127
128 intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) {
129 return NULL;
130 }
131
132 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
133 intptr_t** ret_sp, intptr_t** ret_fp) {
134
135 ExtendedPC epc;
136 const ucontext_t* uc = (const ucontext_t*)ucVoid;
137
138 if (uc != NULL) {
139 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
140 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc);
141 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc);
142 } else {
143 // construct empty ExtendedPC for return value checking
144 epc = ExtendedPC(NULL);
145 if (ret_sp) *ret_sp = (intptr_t *)NULL;
146 if (ret_fp) *ret_fp = (intptr_t *)NULL;
147 }
148
149 return epc;
150 }
151
152 frame os::fetch_frame_from_context(const void* ucVoid) {
153 intptr_t* sp;
154 intptr_t* fp;
155 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
156 return frame(sp, epc.pc());
157 }
158
159 bool os::Linux::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
160 address pc = (address) os::Linux::ucontext_get_pc(uc);
161 if (Interpreter::contains(pc)) {
162 // Interpreter performs stack banging after the fixed frame header has
163 // been generated while the compilers perform it before. To maintain
164 // semantic consistency between interpreted and compiled frames, the
165 // method returns the Java sender of the current frame.
166 *fr = os::fetch_frame_from_context(uc);
167 if (!fr->is_first_java_frame()) {
168 assert(fr->safe_for_sender(thread), "Safety check");
169 *fr = fr->java_sender();
170 }
171 } else {
172 // More complex code with compiled code.
173 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
174 CodeBlob* cb = CodeCache::find_blob(pc);
175 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
176 // Not sure where the pc points to, fallback to default
177 // stack overflow handling. In compiled code, we bang before
178 // the frame is complete.
179 return false;
180 } else {
181 intptr_t* fp = os::Linux::ucontext_get_fp(uc);
182 intptr_t* sp = os::Linux::ucontext_get_sp(uc);
183 *fr = frame(sp, (address)*sp);
184 if (!fr->is_java_frame()) {
185 assert(fr->safe_for_sender(thread), "Safety check");
186 assert(!fr->is_first_frame(), "Safety check");
187 *fr = fr->java_sender();
188 }
189 }
190 }
191 assert(fr->is_java_frame(), "Safety check");
192 return true;
193 }
194
195 frame os::get_sender_for_C_frame(frame* fr) {
196 if (*fr->sp() == 0) {
197 // fr is the last C frame
198 return frame(NULL, NULL);
199 }
200 return frame(fr->sender_sp(), fr->sender_pc());
201 }
202
203
204 frame os::current_frame() {
205 intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer());
206 // hack.
207 frame topframe(csp, (address)0x8);
208 // return sender of current topframe which hopefully has pc != NULL.
209 return os::get_sender_for_C_frame(&topframe);
210 }
211
212 // Utility functions
213
214 extern "C" JNIEXPORT int
215 JVM_handle_linux_signal(int sig,
216 siginfo_t* info,
217 void* ucVoid,
218 int abort_if_unrecognized) {
219 ucontext_t* uc = (ucontext_t*) ucVoid;
220
221 Thread* t = Thread::current_or_null_safe();
222
223 SignalHandlerMark shm(t);
224
225 // Note: it's not uncommon that JNI code uses signal/sigset to install
226 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
227 // or have a SIGILL handler when detecting CPU type). When that happens,
228 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
229 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
230 // that do not require siginfo/ucontext first.
231
232 if (sig == SIGPIPE) {
233 if (os::Linux::chained_handler(sig, info, ucVoid)) {
234 return true;
235 } else {
236 // Ignoring SIGPIPE - see bugs 4229104
237 return true;
238 }
239 }
240
241 // Make the signal handler transaction-aware by checking the existence of a
242 // second (transactional) context with MSR TS bits active. If the signal is
243 // caught during a transaction, then just return to the HTM abort handler.
244 // Please refer to Linux kernel document powerpc/transactional_memory.txt,
245 // section "Signals".
246 if (uc && uc->uc_link) {
247 ucontext_t* second_uc = uc->uc_link;
248
249 // MSR TS bits are 29 and 30 (Power ISA, v2.07B, Book III-S, pp. 857-858,
250 // 3.2.1 "Machine State Register"), however note that ISA notation for bit
251 // numbering is MSB 0, so for normal bit numbering (LSB 0) they come to be
252 // bits 33 and 34. It's not related to endianness, just a notation matter.
253 if (second_uc->uc_mcontext.regs->msr & 0x600000000) {
254 if (TraceTraps) {
255 tty->print_cr("caught signal in transaction, "
256 "ignoring to jump to abort handler");
257 }
258 // Return control to the HTM abort handler.
259 return true;
260 }
261 }
262
263 JavaThread* thread = NULL;
264 VMThread* vmthread = NULL;
265 if (os::Linux::signal_handlers_are_installed) {
266 if (t != NULL) {
267 if(t->is_Java_thread()) {
268 thread = (JavaThread*)t;
269 } else if(t->is_VM_thread()) {
270 vmthread = (VMThread *)t;
271 }
272 }
273 }
274
275 // Moved SafeFetch32 handling outside thread!=NULL conditional block to make
276 // it work if no associated JavaThread object exists.
277 if (uc) {
278 address const pc = os::Linux::ucontext_get_pc(uc);
279 if (pc && StubRoutines::is_safefetch_fault(pc)) {
280 os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
281 return true;
282 }
283 }
284
285 // decide if this trap can be handled by a stub
286 address stub = NULL;
287 address pc = NULL;
288
289 //%note os_trap_1
290 if (info != NULL && uc != NULL && thread != NULL) {
291 pc = (address) os::Linux::ucontext_get_pc(uc);
292
293 // Handle ALL stack overflow variations here
294 if (sig == SIGSEGV) {
295 // Si_addr may not be valid due to a bug in the linux-ppc64 kernel (see
296 // comment below). Use get_stack_bang_address instead of si_addr.
297 address addr = ((NativeInstruction*)pc)->get_stack_bang_address(uc);
298
299 // Check if fault address is within thread stack.
300 if (thread->on_local_stack(addr)) {
301 // stack overflow
302 if (thread->in_stack_yellow_reserved_zone(addr)) {
303 if (thread->thread_state() == _thread_in_Java) {
304 if (thread->in_stack_reserved_zone(addr)) {
305 frame fr;
306 if (os::Linux::get_frame_at_stack_banging_point(thread, uc, &fr)) {
307 assert(fr.is_java_frame(), "Must be a Javac frame");
308 frame activation =
309 SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
310 if (activation.sp() != NULL) {
311 thread->disable_stack_reserved_zone();
312 if (activation.is_interpreted_frame()) {
313 thread->set_reserved_stack_activation((address)activation.fp());
314 } else {
315 thread->set_reserved_stack_activation((address)activation.unextended_sp());
316 }
317 return 1;
318 }
319 }
320 }
321 // Throw a stack overflow exception.
322 // Guard pages will be reenabled while unwinding the stack.
323 thread->disable_stack_yellow_reserved_zone();
324 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
325 } else {
326 // Thread was in the vm or native code. Return and try to finish.
327 thread->disable_stack_yellow_reserved_zone();
328 return 1;
329 }
330 } else if (thread->in_stack_red_zone(addr)) {
331 // Fatal red zone violation. Disable the guard pages and fall through
332 // to handle_unexpected_exception way down below.
333 thread->disable_stack_red_zone();
334 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
335
336 // This is a likely cause, but hard to verify. Let's just print
337 // it as a hint.
338 tty->print_raw_cr("Please check if any of your loaded .so files has "
339 "enabled executable stack (see man page execstack(8))");
340 } else {
341 // Accessing stack address below sp may cause SEGV if current
342 // thread has MAP_GROWSDOWN stack. This should only happen when
343 // current thread was created by user code with MAP_GROWSDOWN flag
344 // and then attached to VM. See notes in os_linux.cpp.
345 if (thread->osthread()->expanding_stack() == 0) {
346 thread->osthread()->set_expanding_stack();
347 if (os::Linux::manually_expand_stack(thread, addr)) {
348 thread->osthread()->clear_expanding_stack();
349 return 1;
350 }
351 thread->osthread()->clear_expanding_stack();
352 } else {
353 fatal("recursive segv. expanding stack.");
354 }
355 }
356 }
357 }
358
359 if (thread->thread_state() == _thread_in_Java) {
360 // Java thread running in Java code => find exception handler if any
361 // a fault inside compiled code, the interpreter, or a stub
362
363 // A VM-related SIGILL may only occur if we are not in the zero page.
364 // On AIX, we get a SIGILL if we jump to 0x0 or to somewhere else
365 // in the zero page, because it is filled with 0x0. We ignore
366 // explicit SIGILLs in the zero page.
367 if (sig == SIGILL && (pc < (address) 0x200)) {
368 if (TraceTraps) {
369 tty->print_raw_cr("SIGILL happened inside zero page.");
370 }
371 goto report_and_die;
372 }
373
374 CodeBlob *cb = NULL;
375 // Handle signal from NativeJump::patch_verified_entry().
376 if (( TrapBasedNotEntrantChecks && sig == SIGTRAP && nativeInstruction_at(pc)->is_sigtrap_zombie_not_entrant()) ||
377 (!TrapBasedNotEntrantChecks && sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant())) {
378 if (TraceTraps) {
379 tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL");
380 }
381 stub = SharedRuntime::get_handle_wrong_method_stub();
382 }
383
384 else if (sig == SIGSEGV &&
385 // A linux-ppc64 kernel before 2.6.6 doesn't set si_addr on some segfaults
386 // in 64bit mode (cf. http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.6),
387 // especially when we try to read from the safepoint polling page. So the check
388 // (address)info->si_addr == os::get_standard_polling_page()
389 // doesn't work for us. We use:
390 ((NativeInstruction*)pc)->is_safepoint_poll() &&
391 CodeCache::contains((void*) pc) &&
392 ((cb = CodeCache::find_blob(pc)) != NULL) &&
393 cb->is_compiled()) {
394 if (TraceTraps) {
395 tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
396 }
397 stub = SharedRuntime::get_poll_stub(pc);
398 }
399
400 // SIGTRAP-based ic miss check in compiled code.
401 else if (sig == SIGTRAP && TrapBasedICMissChecks &&
402 nativeInstruction_at(pc)->is_sigtrap_ic_miss_check()) {
403 if (TraceTraps) {
404 tty->print_cr("trap: ic_miss_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
405 }
406 stub = SharedRuntime::get_ic_miss_stub();
407 }
408
409 // SIGTRAP-based implicit null check in compiled code.
410 else if (sig == SIGTRAP && TrapBasedNullChecks &&
411 nativeInstruction_at(pc)->is_sigtrap_null_check()) {
412 if (TraceTraps) {
413 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
414 }
415 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
416 }
417
418 // SIGSEGV-based implicit null check in compiled code.
419 else if (sig == SIGSEGV && ImplicitNullChecks &&
420 CodeCache::contains((void*) pc) &&
421 !MacroAssembler::needs_explicit_null_check((intptr_t) info->si_addr)) {
422 if (TraceTraps) {
423 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
424 }
425 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
426 }
427
428 #ifdef COMPILER2
429 // SIGTRAP-based implicit range check in compiled code.
430 else if (sig == SIGTRAP && TrapBasedRangeChecks &&
431 nativeInstruction_at(pc)->is_sigtrap_range_check()) {
432 if (TraceTraps) {
433 tty->print_cr("trap: range_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
434 }
435 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
436 }
437 #endif
438 else if (sig == SIGBUS) {
439 // BugId 4454115: A read from a MappedByteBuffer can fault here if the
440 // underlying file has been truncated. Do not crash the VM in such a case.
441 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
442 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
443 if (nm != NULL && nm->has_unsafe_access()) {
444 address next_pc = pc + 4;
445 next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
446 os::Linux::ucontext_set_pc(uc, next_pc);
447 return true;
448 }
449 }
450 }
451
452 else { // thread->thread_state() != _thread_in_Java
453 if (sig == SIGILL && VM_Version::is_determine_features_test_running()) {
454 // SIGILL must be caused by VM_Version::determine_features().
455 *(int *)pc = 0; // patch instruction to 0 to indicate that it causes a SIGILL,
456 // flushing of icache is not necessary.
457 stub = pc + 4; // continue with next instruction.
458 }
459 else if (thread->thread_state() == _thread_in_vm &&
460 sig == SIGBUS && thread->doing_unsafe_access()) {
461 address next_pc = pc + 4;
462 next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
463 os::Linux::ucontext_set_pc(uc, pc + 4);
464 return true;
465 }
466 }
467
468 // Check to see if we caught the safepoint code in the
469 // process of write protecting the memory serialization page.
470 // It write enables the page immediately after protecting it
471 // so we can just return to retry the write.
472 if ((sig == SIGSEGV) &&
473 // Si_addr may not be valid due to a bug in the linux-ppc64 kernel (see comment above).
474 // Use is_memory_serialization instead of si_addr.
475 ((NativeInstruction*)pc)->is_memory_serialization(thread, ucVoid)) {
476 // Synchronization problem in the pseudo memory barrier code (bug id 6546278)
477 // Block current thread until the memory serialize page permission restored.
478 os::block_on_serialize_page_trap();
479 return true;
480 }
481 }
482
483 if (stub != NULL) {
484 // Save all thread context in case we need to restore it.
485 if (thread != NULL) thread->set_saved_exception_pc(pc);
486 os::Linux::ucontext_set_pc(uc, stub);
487 return true;
488 }
489
490 // signal-chaining
491 if (os::Linux::chained_handler(sig, info, ucVoid)) {
492 return true;
493 }
494
495 if (!abort_if_unrecognized) {
496 // caller wants another chance, so give it to him
497 return false;
498 }
499
500 if (pc == NULL && uc != NULL) {
501 pc = os::Linux::ucontext_get_pc(uc);
502 }
503
504 report_and_die:
505 // unmask current signal
506 sigset_t newset;
507 sigemptyset(&newset);
508 sigaddset(&newset, sig);
509 sigprocmask(SIG_UNBLOCK, &newset, NULL);
510
511 VMError::report_and_die(t, sig, pc, info, ucVoid);
512
513 ShouldNotReachHere();
514 return false;
515 }
516
517 void os::Linux::init_thread_fpu_state(void) {
518 // Disable FP exceptions.
519 __asm__ __volatile__ ("mtfsfi 6,0");
520 }
521
522 int os::Linux::get_fpu_control_word(void) {
523 // x86 has problems with FPU precision after pthread_cond_timedwait().
524 // nothing to do on ppc64.
525 return 0;
526 }
527
528 void os::Linux::set_fpu_control_word(int fpu_control) {
529 // x86 has problems with FPU precision after pthread_cond_timedwait().
530 // nothing to do on ppc64.
531 }
532
533 ////////////////////////////////////////////////////////////////////////////////
534 // thread stack
535
536 size_t os::Posix::_compiler_thread_min_stack_allowed = 128 * K;
537 size_t os::Posix::_java_thread_min_stack_allowed = 128 * K;
538 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 128 * K;
539
540 // return default stack size for thr_type
541 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
542 // default stack size (compiler thread needs larger stack)
543 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1024 * K);
544 return s;
545 }
546
547 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
548 return 2 * page_size();
549 }
550
551 // Java thread:
552 //
553 // Low memory addresses
554 // +------------------------+
555 // | |\ JavaThread created by VM does not have glibc
556 // | glibc guard page | - guard, attached Java thread usually has
557 // | |/ 1 page glibc guard.
558 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
559 // | |\
560 // | HotSpot Guard Pages | - red and yellow pages
561 // | |/
562 // +------------------------+ JavaThread::stack_yellow_zone_base()
563 // | |\
564 // | Normal Stack | -
565 // | |/
566 // P2 +------------------------+ Thread::stack_base()
567 //
568 // Non-Java thread:
569 //
570 // Low memory addresses
571 // +------------------------+
572 // | |\
573 // | glibc guard page | - usually 1 page
574 // | |/
575 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
576 // | |\
577 // | Normal Stack | -
578 // | |/
579 // P2 +------------------------+ Thread::stack_base()
580 //
581 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
582 // pthread_attr_getstack()
583
584 static void current_stack_region(address * bottom, size_t * size) {
585 if (os::Linux::is_initial_thread()) {
586 // initial thread needs special handling because pthread_getattr_np()
587 // may return bogus value.
588 *bottom = os::Linux::initial_thread_stack_bottom();
589 *size = os::Linux::initial_thread_stack_size();
590 } else {
591 pthread_attr_t attr;
592
593 int rslt = pthread_getattr_np(pthread_self(), &attr);
594
595 // JVM needs to know exact stack location, abort if it fails
596 if (rslt != 0) {
597 if (rslt == ENOMEM) {
598 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
599 } else {
600 fatal("pthread_getattr_np failed with errno = %d", rslt);
601 }
602 }
603
604 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
605 fatal("Can not locate current stack attributes!");
606 }
607
608 pthread_attr_destroy(&attr);
609
610 }
611 assert(os::current_stack_pointer() >= *bottom &&
612 os::current_stack_pointer() < *bottom + *size, "just checking");
613 }
614
615 address os::current_stack_base() {
616 address bottom;
617 size_t size;
618 current_stack_region(&bottom, &size);
619 return (bottom + size);
620 }
621
622 size_t os::current_stack_size() {
623 // stack size includes normal stack and HotSpot guard pages
624 address bottom;
625 size_t size;
626 current_stack_region(&bottom, &size);
627 return size;
628 }
629
630 /////////////////////////////////////////////////////////////////////////////
631 // helper functions for fatal error handler
632
633 void os::print_context(outputStream *st, const void *context) {
634 if (context == NULL) return;
635
636 const ucontext_t* uc = (const ucontext_t*)context;
637
638 st->print_cr("Registers:");
639 st->print("pc =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->nip);
640 st->print("lr =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->link);
641 st->print("ctr=" INTPTR_FORMAT " ", uc->uc_mcontext.regs->ctr);
642 st->cr();
643 for (int i = 0; i < 32; i++) {
644 st->print("r%-2d=" INTPTR_FORMAT " ", i, uc->uc_mcontext.regs->gpr[i]);
645 if (i % 3 == 2) st->cr();
646 }
647 st->cr();
648 st->cr();
649
650 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
651 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp));
652 print_hex_dump(st, (address)sp, (address)(sp + 128), sizeof(intptr_t));
653 st->cr();
654
655 // Note: it may be unsafe to inspect memory near pc. For example, pc may
656 // point to garbage if entry point in an nmethod is corrupted. Leave
657 // this at the end, and hope for the best.
658 address pc = os::Linux::ucontext_get_pc(uc);
659 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc));
660 print_hex_dump(st, pc - 64, pc + 64, /*instrsize=*/4);
661 st->cr();
662 }
663
664 void os::print_register_info(outputStream *st, const void *context) {
665 if (context == NULL) return;
666
667 const ucontext_t *uc = (const ucontext_t*)context;
668
669 st->print_cr("Register to memory mapping:");
670 st->cr();
671
672 // this is only for the "general purpose" registers
673 for (int i = 0; i < 32; i++) {
674 st->print("r%-2d=", i);
675 print_location(st, uc->uc_mcontext.regs->gpr[i]);
676 }
677 st->cr();
678 }
679
680 extern "C" {
681 int SpinPause() {
682 return 0;
683 }
684 }
685
686 #ifndef PRODUCT
687 void os::verify_stack_alignment() {
688 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
689 }
690 #endif
691
692 int os::extra_bang_size_in_bytes() {
693 // PPC does not require the additional stack bang.
694 return 0;
695 }