1 /*
2 * Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 // no precompiled headers
26 #include "asm/macroAssembler.hpp"
27 #include "classfile/classLoader.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/icBuffer.hpp"
31 #include "code/vtableStubs.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "jvm_linux.h"
34 #include "memory/allocation.inline.hpp"
35 #include "mutex_linux.inline.hpp"
36 #include "nativeInst_sparc.hpp"
37 #include "os_share_linux.hpp"
38 #include "prims/jniFastGetField.hpp"
39 #include "prims/jvm.h"
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.hpp"
45 #include "runtime/java.hpp"
46 #include "runtime/javaCalls.hpp"
47 #include "runtime/mutexLocker.hpp"
48 #include "runtime/osThread.hpp"
49 #include "runtime/sharedRuntime.hpp"
50 #include "runtime/stubRoutines.hpp"
51 #include "runtime/thread.inline.hpp"
52 #include "runtime/timer.hpp"
53 #include "utilities/events.hpp"
54 #include "utilities/vmError.hpp"
55
56 // Linux/Sparc has rather obscure naming of registers in sigcontext
57 // different between 32 and 64 bits
58 #ifdef _LP64
59 #define SIG_PC(x) ((x)->sigc_regs.tpc)
60 #define SIG_NPC(x) ((x)->sigc_regs.tnpc)
61 #define SIG_REGS(x) ((x)->sigc_regs)
62 #else
63 #define SIG_PC(x) ((x)->si_regs.pc)
64 #define SIG_NPC(x) ((x)->si_regs.npc)
65 #define SIG_REGS(x) ((x)->si_regs)
66 #endif
67
68 // those are to reference registers in sigcontext
69 enum {
70 CON_G0 = 0,
71 CON_G1,
72 CON_G2,
73 CON_G3,
74 CON_G4,
75 CON_G5,
76 CON_G6,
77 CON_G7,
78 CON_O0,
79 CON_O1,
80 CON_O2,
81 CON_O3,
82 CON_O4,
83 CON_O5,
84 CON_O6,
85 CON_O7,
86 };
87
88 static inline void set_cont_address(sigcontext* ctx, address addr) {
89 SIG_PC(ctx) = (intptr_t)addr;
90 SIG_NPC(ctx) = (intptr_t)(addr+4);
91 }
92
93 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is
94 // currently interrupted by SIGPROF.
95 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested
96 // signal frames. Currently we don't do that on Linux, so it's the
97 // same as os::fetch_frame_from_context().
98 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
99 ucontext_t* uc,
100 intptr_t** ret_sp,
101 intptr_t** ret_fp) {
102 assert(thread != NULL, "just checking");
103 assert(ret_sp != NULL, "just checking");
104 assert(ret_fp != NULL, "just checking");
105
106 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
107 }
108
109 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
110 intptr_t** ret_sp,
111 intptr_t** ret_fp) {
112 ucontext_t* uc = (ucontext_t*) ucVoid;
113 ExtendedPC epc;
114
115 if (uc != NULL) {
116 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
117 if (ret_sp) {
118 *ret_sp = os::Linux::ucontext_get_sp(uc);
119 }
120 if (ret_fp) {
121 *ret_fp = os::Linux::ucontext_get_fp(uc);
122 }
123 } else {
124 // construct empty ExtendedPC for return value checking
125 epc = ExtendedPC(NULL);
126 if (ret_sp) {
127 *ret_sp = (intptr_t*) NULL;
128 }
129 if (ret_fp) {
130 *ret_fp = (intptr_t*) NULL;
131 }
132 }
133
134 return epc;
135 }
136
137 frame os::fetch_frame_from_context(void* ucVoid) {
138 intptr_t* sp;
139 intptr_t* fp;
140 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
141 return frame(sp, fp, epc.pc());
142 }
143
144 frame os::get_sender_for_C_frame(frame* fr) {
145 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
146 }
147
148 frame os::current_frame() {
149 fprintf(stderr, "current_frame()");
150
151 intptr_t* sp = StubRoutines::Sparc::flush_callers_register_windows_func()();
152 frame myframe(sp, frame::unpatchable,
153 CAST_FROM_FN_PTR(address, os::current_frame));
154 if (os::is_first_C_frame(&myframe)) {
155 // stack is not walkable
156 return frame(NULL, frame::unpatchable, NULL);
157 } else {
158 return os::get_sender_for_C_frame(&myframe);
159 }
160 }
161
162 address os::current_stack_pointer() {
163 register void *sp __asm__ ("sp");
164 return (address)sp;
165 }
166
167 static void current_stack_region(address* bottom, size_t* size) {
168 if (os::Linux::is_initial_thread()) {
169 // initial thread needs special handling because pthread_getattr_np()
170 // may return bogus value.
171 *bottom = os::Linux::initial_thread_stack_bottom();
172 *size = os::Linux::initial_thread_stack_size();
173 } else {
174 pthread_attr_t attr;
175
176 int rslt = pthread_getattr_np(pthread_self(), &attr);
177
178 // JVM needs to know exact stack location, abort if it fails
179 if (rslt != 0) {
180 if (rslt == ENOMEM) {
181 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
182 } else {
183 fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt));
184 }
185 }
186
187 if (pthread_attr_getstack(&attr, (void**)bottom, size) != 0) {
188 fatal("Can not locate current stack attributes!");
189 }
190
191 pthread_attr_destroy(&attr);
192 }
193 assert(os::current_stack_pointer() >= *bottom &&
194 os::current_stack_pointer() < *bottom + *size, "just checking");
195 }
196
197 address os::current_stack_base() {
198 address bottom;
199 size_t size;
200 current_stack_region(&bottom, &size);
201 return bottom + size;
202 }
203
204 size_t os::current_stack_size() {
205 // stack size includes normal stack and HotSpot guard pages
206 address bottom;
207 size_t size;
208 current_stack_region(&bottom, &size);
209 return size;
210 }
211
212 char* os::non_memory_address_word() {
213 // Must never look like an address returned by reserve_memory,
214 // even in its subfields (as defined by the CPU immediate fields,
215 // if the CPU splits constants across multiple instructions).
216 // On SPARC, 0 != %hi(any real address), because there is no
217 // allocation in the first 1Kb of the virtual address space.
218 return (char*) 0;
219 }
220
221 void os::initialize_thread(Thread* thr) {}
222
223 void os::print_context(outputStream *st, void *context) {
224 if (context == NULL) return;
225
226 ucontext_t* uc = (ucontext_t*)context;
227 sigcontext* sc = (sigcontext*)context;
228 st->print_cr("Registers:");
229
230 st->print_cr(" G1=" INTPTR_FORMAT " G2=" INTPTR_FORMAT
231 " G3=" INTPTR_FORMAT " G4=" INTPTR_FORMAT,
232 SIG_REGS(sc).u_regs[CON_G1],
233 SIG_REGS(sc).u_regs[CON_G2],
234 SIG_REGS(sc).u_regs[CON_G3],
235 SIG_REGS(sc).u_regs[CON_G4]);
236 st->print_cr(" G5=" INTPTR_FORMAT " G6=" INTPTR_FORMAT
237 " G7=" INTPTR_FORMAT " Y=" INTPTR_FORMAT,
238 SIG_REGS(sc).u_regs[CON_G5],
239 SIG_REGS(sc).u_regs[CON_G6],
240 SIG_REGS(sc).u_regs[CON_G7],
241 SIG_REGS(sc).y);
242 st->print_cr(" O0=" INTPTR_FORMAT " O1=" INTPTR_FORMAT
243 " O2=" INTPTR_FORMAT " O3=" INTPTR_FORMAT,
244 SIG_REGS(sc).u_regs[CON_O0],
245 SIG_REGS(sc).u_regs[CON_O1],
246 SIG_REGS(sc).u_regs[CON_O2],
247 SIG_REGS(sc).u_regs[CON_O3]);
248 st->print_cr(" O4=" INTPTR_FORMAT " O5=" INTPTR_FORMAT
249 " O6=" INTPTR_FORMAT " O7=" INTPTR_FORMAT,
250 SIG_REGS(sc).u_regs[CON_O4],
251 SIG_REGS(sc).u_regs[CON_O5],
252 SIG_REGS(sc).u_regs[CON_O6],
253 SIG_REGS(sc).u_regs[CON_O7]);
254
255
256 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
257 st->print_cr(" L0=" INTPTR_FORMAT " L1=" INTPTR_FORMAT
258 " L2=" INTPTR_FORMAT " L3=" INTPTR_FORMAT,
259 sp[L0->sp_offset_in_saved_window()],
260 sp[L1->sp_offset_in_saved_window()],
261 sp[L2->sp_offset_in_saved_window()],
262 sp[L3->sp_offset_in_saved_window()]);
263 st->print_cr(" L4=" INTPTR_FORMAT " L5=" INTPTR_FORMAT
264 " L6=" INTPTR_FORMAT " L7=" INTPTR_FORMAT,
265 sp[L4->sp_offset_in_saved_window()],
266 sp[L5->sp_offset_in_saved_window()],
267 sp[L6->sp_offset_in_saved_window()],
268 sp[L7->sp_offset_in_saved_window()]);
269 st->print_cr(" I0=" INTPTR_FORMAT " I1=" INTPTR_FORMAT
270 " I2=" INTPTR_FORMAT " I3=" INTPTR_FORMAT,
271 sp[I0->sp_offset_in_saved_window()],
272 sp[I1->sp_offset_in_saved_window()],
273 sp[I2->sp_offset_in_saved_window()],
274 sp[I3->sp_offset_in_saved_window()]);
275 st->print_cr(" I4=" INTPTR_FORMAT " I5=" INTPTR_FORMAT
276 " I6=" INTPTR_FORMAT " I7=" INTPTR_FORMAT,
277 sp[I4->sp_offset_in_saved_window()],
278 sp[I5->sp_offset_in_saved_window()],
279 sp[I6->sp_offset_in_saved_window()],
280 sp[I7->sp_offset_in_saved_window()]);
281
282 st->print_cr(" PC=" INTPTR_FORMAT " nPC=" INTPTR_FORMAT,
283 SIG_PC(sc),
284 SIG_NPC(sc));
285 st->cr();
286 st->cr();
287
288 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
289 print_hex_dump(st, (address)sp, (address)(sp + 32), sizeof(intptr_t));
290 st->cr();
291
292 // Note: it may be unsafe to inspect memory near pc. For example, pc may
293 // point to garbage if entry point in an nmethod is corrupted. Leave
294 // this at the end, and hope for the best.
295 address pc = os::Linux::ucontext_get_pc(uc);
296 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
297 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
298 }
299
300
301 void os::print_register_info(outputStream *st, void *context) {
302 if (context == NULL) return;
303
304 ucontext_t *uc = (ucontext_t*)context;
305 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
306
307 st->print_cr("Register to memory mapping:");
308 st->cr();
309
310 // this is only for the "general purpose" registers
311 st->print("G1="); print_location(st, SIG_REGS(sc).u_regs[CON__G1]);
312 st->print("G2="); print_location(st, SIG_REGS(sc).u_regs[CON__G2]);
313 st->print("G3="); print_location(st, SIG_REGS(sc).u_regs[CON__G3]);
314 st->print("G4="); print_location(st, SIG_REGS(sc).u_regs[CON__G4]);
315 st->print("G5="); print_location(st, SIG_REGS(sc).u_regs[CON__G5]);
316 st->print("G6="); print_location(st, SIG_REGS(sc).u_regs[CON__G6]);
317 st->print("G7="); print_location(st, SIG_REGS(sc).u_regs[CON__G7]);
318 st->cr();
319
320 st->print("O0="); print_location(st, SIG_REGS(sc).u_regs[CON__O0]);
321 st->print("O1="); print_location(st, SIG_REGS(sc).u_regs[CON__O1]);
322 st->print("O2="); print_location(st, SIG_REGS(sc).u_regs[CON__O2]);
323 st->print("O3="); print_location(st, SIG_REGS(sc).u_regs[CON__O3]);
324 st->print("O4="); print_location(st, SIG_REGS(sc).u_regs[CON__O4]);
325 st->print("O5="); print_location(st, SIG_REGS(sc).u_regs[CON__O5]);
326 st->print("O6="); print_location(st, SIG_REGS(sc).u_regs[CON__O6]);
327 st->print("O7="); print_location(st, SIG_REGS(sc).u_regs[CON__O7]);
328 st->cr();
329
330 st->print("L0="); print_location(st, sp[L0->sp_offset_in_saved_window()]);
331 st->print("L1="); print_location(st, sp[L1->sp_offset_in_saved_window()]);
332 st->print("L2="); print_location(st, sp[L2->sp_offset_in_saved_window()]);
333 st->print("L3="); print_location(st, sp[L3->sp_offset_in_saved_window()]);
334 st->print("L4="); print_location(st, sp[L4->sp_offset_in_saved_window()]);
335 st->print("L5="); print_location(st, sp[L5->sp_offset_in_saved_window()]);
336 st->print("L6="); print_location(st, sp[L6->sp_offset_in_saved_window()]);
337 st->print("L7="); print_location(st, sp[L7->sp_offset_in_saved_window()]);
338 st->cr();
339
340 st->print("I0="); print_location(st, sp[I0->sp_offset_in_saved_window()]);
341 st->print("I1="); print_location(st, sp[I1->sp_offset_in_saved_window()]);
342 st->print("I2="); print_location(st, sp[I2->sp_offset_in_saved_window()]);
343 st->print("I3="); print_location(st, sp[I3->sp_offset_in_saved_window()]);
344 st->print("I4="); print_location(st, sp[I4->sp_offset_in_saved_window()]);
345 st->print("I5="); print_location(st, sp[I5->sp_offset_in_saved_window()]);
346 st->print("I6="); print_location(st, sp[I6->sp_offset_in_saved_window()]);
347 st->print("I7="); print_location(st, sp[I7->sp_offset_in_saved_window()]);
348 st->cr();
349 }
350
351
352 address os::Linux::ucontext_get_pc(ucontext_t* uc) {
353 return (address) SIG_PC((sigcontext*)uc);
354 }
355
356 intptr_t* os::Linux::ucontext_get_sp(ucontext_t *uc) {
357 return (intptr_t*)
358 ((intptr_t)SIG_REGS((sigcontext*)uc).u_regs[CON_O6] + STACK_BIAS);
359 }
360
361 // not used on Sparc
362 intptr_t* os::Linux::ucontext_get_fp(ucontext_t *uc) {
363 ShouldNotReachHere();
364 return NULL;
365 }
366
367 // Utility functions
368
369 extern "C" void Fetch32PFI();
370 extern "C" void Fetch32Resume();
371 extern "C" void FetchNPFI();
372 extern "C" void FetchNResume();
373
374 inline static bool checkPrefetch(sigcontext* uc, address pc) {
375 if (pc == (address) Fetch32PFI) {
376 set_cont_address(uc, address(Fetch32Resume));
377 return true;
378 }
379 if (pc == (address) FetchNPFI) {
380 set_cont_address(uc, address(FetchNResume));
381 return true;
382 }
383 return false;
384 }
385
386 inline static bool checkOverflow(sigcontext* uc,
387 address pc,
388 address addr,
389 JavaThread* thread,
390 address* stub) {
391 // check if fault address is within thread stack
392 if (addr < thread->stack_base() &&
393 addr >= thread->stack_base() - thread->stack_size()) {
394 // stack overflow
395 if (thread->in_stack_yellow_zone(addr)) {
396 thread->disable_stack_yellow_zone();
397 if (thread->thread_state() == _thread_in_Java) {
398 // Throw a stack overflow exception. Guard pages will be reenabled
399 // while unwinding the stack.
400 *stub =
401 SharedRuntime::continuation_for_implicit_exception(thread,
402 pc,
403 SharedRuntime::STACK_OVERFLOW);
404 } else {
405 // Thread was in the vm or native code. Return and try to finish.
406 return true;
407 }
408 } else if (thread->in_stack_red_zone(addr)) {
409 // Fatal red zone violation. Disable the guard pages and fall through
410 // to handle_unexpected_exception way down below.
411 thread->disable_stack_red_zone();
412 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
413
414 // This is a likely cause, but hard to verify. Let's just print
415 // it as a hint.
416 tty->print_raw_cr("Please check if any of your loaded .so files has "
417 "enabled executable stack (see man page execstack(8))");
418 } else {
419 // Accessing stack address below sp may cause SEGV if current
420 // thread has MAP_GROWSDOWN stack. This should only happen when
421 // current thread was created by user code with MAP_GROWSDOWN flag
422 // and then attached to VM. See notes in os_linux.cpp.
423 if (thread->osthread()->expanding_stack() == 0) {
424 thread->osthread()->set_expanding_stack();
425 if (os::Linux::manually_expand_stack(thread, addr)) {
426 thread->osthread()->clear_expanding_stack();
427 return true;
428 }
429 thread->osthread()->clear_expanding_stack();
430 } else {
431 fatal("recursive segv. expanding stack.");
432 }
433 }
434 }
435 return false;
436 }
437
438 inline static bool checkPollingPage(address pc, address fault, address* stub) {
439 if (fault == os::get_polling_page()) {
440 *stub = SharedRuntime::get_poll_stub(pc);
441 return true;
442 }
443 return false;
444 }
445
446 inline static bool checkByteBuffer(address pc, address* stub) {
447 // BugId 4454115: A read from a MappedByteBuffer can fault
448 // here if the underlying file has been truncated.
449 // Do not crash the VM in such a case.
450 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
451 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
452 if (nm != NULL && nm->has_unsafe_access()) {
453 *stub = StubRoutines::handler_for_unsafe_access();
454 return true;
455 }
456 return false;
457 }
458
459 inline static bool checkVerifyOops(address pc, address fault, address* stub) {
460 if (pc >= MacroAssembler::_verify_oop_implicit_branch[0]
461 && pc < MacroAssembler::_verify_oop_implicit_branch[1] ) {
462 *stub = MacroAssembler::_verify_oop_implicit_branch[2];
463 warning("fixed up memory fault in +VerifyOops at address "
464 INTPTR_FORMAT, fault);
465 return true;
466 }
467 return false;
468 }
469
470 inline static bool checkFPFault(address pc, int code,
471 JavaThread* thread, address* stub) {
472 if (code == FPE_INTDIV || code == FPE_FLTDIV) {
473 *stub =
474 SharedRuntime::
475 continuation_for_implicit_exception(thread,
476 pc,
477 SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
478 return true;
479 }
480 return false;
481 }
482
483 inline static bool checkNullPointer(address pc, intptr_t fault,
484 JavaThread* thread, address* stub) {
485 if (!MacroAssembler::needs_explicit_null_check(fault)) {
486 // Determination of interpreter/vtable stub/compiled code null
487 // exception
488 *stub =
489 SharedRuntime::
490 continuation_for_implicit_exception(thread, pc,
491 SharedRuntime::IMPLICIT_NULL);
492 return true;
493 }
494 return false;
495 }
496
497 inline static bool checkFastJNIAccess(address pc, address* stub) {
498 address addr = JNI_FastGetField::find_slowcase_pc(pc);
499 if (addr != (address)-1) {
500 *stub = addr;
501 return true;
502 }
503 return false;
504 }
505
506 inline static bool checkSerializePage(JavaThread* thread, address addr) {
507 return os::is_memory_serialize_page(thread, addr);
508 }
509
510 inline static bool checkZombie(sigcontext* uc, address* pc, address* stub) {
511 if (nativeInstruction_at(*pc)->is_zombie()) {
512 // zombie method (ld [%g0],%o7 instruction)
513 *stub = SharedRuntime::get_handle_wrong_method_stub();
514
515 // At the stub it needs to look like a call from the caller of this
516 // method (not a call from the segv site).
517 *pc = (address)SIG_REGS(uc).u_regs[CON_O7];
518 return true;
519 }
520 return false;
521 }
522
523 inline static bool checkICMiss(sigcontext* uc, address* pc, address* stub) {
524 #ifdef COMPILER2
525 if (nativeInstruction_at(*pc)->is_ic_miss_trap()) {
526 #ifdef ASSERT
527 #ifdef TIERED
528 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
529 assert(cb->is_compiled_by_c2(), "Wrong compiler");
530 #endif // TIERED
531 #endif // ASSERT
532 // Inline cache missed and user trap "Tne G0+ST_RESERVED_FOR_USER_0+2" taken.
533 *stub = SharedRuntime::get_ic_miss_stub();
534 // At the stub it needs to look like a call from the caller of this
535 // method (not a call from the segv site).
536 *pc = (address)SIG_REGS(uc).u_regs[CON_O7];
537 return true;
538 }
539 #endif // COMPILER2
540 return false;
541 }
542
543 extern "C" JNIEXPORT int
544 JVM_handle_linux_signal(int sig,
545 siginfo_t* info,
546 void* ucVoid,
547 int abort_if_unrecognized) {
548 // in fact this isn't ucontext_t* at all, but struct sigcontext*
549 // but Linux porting layer uses ucontext_t, so to minimize code change
550 // we cast as needed
551 ucontext_t* ucFake = (ucontext_t*) ucVoid;
552 sigcontext* uc = (sigcontext*)ucVoid;
553
554 Thread* t = ThreadLocalStorage::get_thread_slow();
555
556 SignalHandlerMark shm(t);
557
558 // Note: it's not uncommon that JNI code uses signal/sigset to install
559 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
560 // or have a SIGILL handler when detecting CPU type). When that happens,
561 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
562 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
563 // that do not require siginfo/ucontext first.
564
565 if (sig == SIGPIPE || sig == SIGXFSZ) {
566 // allow chained handler to go first
567 if (os::Linux::chained_handler(sig, info, ucVoid)) {
568 return true;
569 } else {
570 if (PrintMiscellaneous && (WizardMode || Verbose)) {
571 char buf[64];
572 warning("Ignoring %s - see bugs 4229104 or 646499219",
573 os::exception_name(sig, buf, sizeof(buf)));
574 }
575 return true;
576 }
577 }
578
579 JavaThread* thread = NULL;
580 VMThread* vmthread = NULL;
581 if (os::Linux::signal_handlers_are_installed) {
582 if (t != NULL ){
583 if(t->is_Java_thread()) {
584 thread = (JavaThread*)t;
585 }
586 else if(t->is_VM_thread()){
587 vmthread = (VMThread *)t;
588 }
589 }
590 }
591
592 // decide if this trap can be handled by a stub
593 address stub = NULL;
594 address pc = NULL;
595 address npc = NULL;
596
597 //%note os_trap_1
598 if (info != NULL && uc != NULL && thread != NULL) {
599 pc = address(SIG_PC(uc));
600 npc = address(SIG_NPC(uc));
601
602 // Check to see if we caught the safepoint code in the
603 // process of write protecting the memory serialization page.
604 // It write enables the page immediately after protecting it
605 // so we can just return to retry the write.
606 if ((sig == SIGSEGV) && checkSerializePage(thread, (address)info->si_addr)) {
607 // Block current thread until the memory serialize page permission restored.
608 os::block_on_serialize_page_trap();
609 return 1;
610 }
611
612 if (checkPrefetch(uc, pc)) {
613 return 1;
614 }
615
616 // Handle ALL stack overflow variations here
617 if (sig == SIGSEGV) {
618 if (checkOverflow(uc, pc, (address)info->si_addr, thread, &stub)) {
619 return 1;
620 }
621 }
622
623 if (sig == SIGBUS &&
624 thread->thread_state() == _thread_in_vm &&
625 thread->doing_unsafe_access()) {
626 stub = StubRoutines::handler_for_unsafe_access();
627 }
628
629 if (thread->thread_state() == _thread_in_Java) {
630 do {
631 // Java thread running in Java code => find exception handler if any
632 // a fault inside compiled code, the interpreter, or a stub
633
634 if ((sig == SIGSEGV) && checkPollingPage(pc, (address)info->si_addr, &stub)) {
635 break;
636 }
637
638 if ((sig == SIGBUS) && checkByteBuffer(pc, &stub)) {
639 break;
640 }
641
642 if ((sig == SIGSEGV || sig == SIGBUS) &&
643 checkVerifyOops(pc, (address)info->si_addr, &stub)) {
644 break;
645 }
646
647 if ((sig == SIGSEGV) && checkZombie(uc, &pc, &stub)) {
648 break;
649 }
650
651 if ((sig == SIGILL) && checkICMiss(uc, &pc, &stub)) {
652 break;
653 }
654
655 if ((sig == SIGFPE) && checkFPFault(pc, info->si_code, thread, &stub)) {
656 break;
657 }
658
659 if ((sig == SIGSEGV) &&
660 checkNullPointer(pc, (intptr_t)info->si_addr, thread, &stub)) {
661 break;
662 }
663 } while (0);
664
665 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
666 // and the heap gets shrunk before the field access.
667 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
668 checkFastJNIAccess(pc, &stub);
669 }
670 }
671
672 if (stub != NULL) {
673 // save all thread context in case we need to restore it
674 thread->set_saved_exception_pc(pc);
675 thread->set_saved_exception_npc(npc);
676 set_cont_address(uc, stub);
677 return true;
678 }
679 }
680
681 // signal-chaining
682 if (os::Linux::chained_handler(sig, info, ucVoid)) {
683 return true;
684 }
685
686 if (!abort_if_unrecognized) {
687 // caller wants another chance, so give it to him
688 return false;
689 }
690
691 if (pc == NULL && uc != NULL) {
692 pc = os::Linux::ucontext_get_pc((ucontext_t*)uc);
693 }
694
695 // unmask current signal
696 sigset_t newset;
697 sigemptyset(&newset);
698 sigaddset(&newset, sig);
699 sigprocmask(SIG_UNBLOCK, &newset, NULL);
700
701 VMError err(t, sig, pc, info, ucVoid);
702 err.report_and_die();
703
704 ShouldNotReachHere();
705 }
706
707 void os::Linux::init_thread_fpu_state(void) {
708 // Nothing to do
709 }
710
711 int os::Linux::get_fpu_control_word() {
712 return 0;
713 }
714
715 void os::Linux::set_fpu_control_word(int fpu) {
716 // nothing
717 }
718
719 bool os::is_allocatable(size_t bytes) {
720 #ifdef _LP64
721 return true;
722 #else
723 if (bytes < 2 * G) {
724 return true;
725 }
726
727 char* addr = reserve_memory(bytes, NULL);
728
729 if (addr != NULL) {
730 release_memory(addr, bytes);
731 }
732
733 return addr != NULL;
734 #endif // _LP64
735 }
736
737 ///////////////////////////////////////////////////////////////////////////////
738 // thread stack
739
740 size_t os::Linux::min_stack_allowed = 128 * K;
741
742 // pthread on Ubuntu is always in floating stack mode
743 bool os::Linux::supports_variable_stack_size() { return true; }
744
745 // return default stack size for thr_type
746 size_t os::Linux::default_stack_size(os::ThreadType thr_type) {
747 // default stack size (compiler thread needs larger stack)
748 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
749 return s;
750 }
751
752 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
753 // Creating guard page is very expensive. Java thread has HotSpot
754 // guard page, only enable glibc guard page for non-Java threads.
755 return (thr_type == java_thread ? 0 : page_size());
756 }
757
758 #ifndef PRODUCT
759 void os::verify_stack_alignment() {
760 }
761 #endif