1 /*
2 * Copyright (c) 1999, 2013, 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 = (intptr_t*)NULL;
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 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, NULL);
140 return frame(sp, frame::unpatchable, epc.pc());
141 }
142
143 frame os::get_sender_for_C_frame(frame* fr) {
144 return frame(fr->sender_sp(), frame::unpatchable, fr->sender_pc());
145 }
146
147 frame os::current_frame() {
148 intptr_t* sp = StubRoutines::Sparc::flush_callers_register_windows_func()();
149 frame myframe(sp, frame::unpatchable,
150 CAST_FROM_FN_PTR(address, os::current_frame));
151 if (os::is_first_C_frame(&myframe)) {
152 // stack is not walkable
153 return frame(NULL, frame::unpatchable, NULL);
154 } else {
155 return os::get_sender_for_C_frame(&myframe);
156 }
157 }
158
159 address os::current_stack_pointer() {
160 register void *sp __asm__ ("sp");
161 return (address)sp;
162 }
163
164 static void current_stack_region(address* bottom, size_t* size) {
165 if (os::Linux::is_initial_thread()) {
166 // initial thread needs special handling because pthread_getattr_np()
167 // may return bogus value.
168 *bottom = os::Linux::initial_thread_stack_bottom();
169 *size = os::Linux::initial_thread_stack_size();
170 } else {
171 pthread_attr_t attr;
172
173 int rslt = pthread_getattr_np(pthread_self(), &attr);
174
175 // JVM needs to know exact stack location, abort if it fails
176 if (rslt != 0) {
177 if (rslt == ENOMEM) {
178 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
179 } else {
180 fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt));
181 }
182 }
183
184 if (pthread_attr_getstack(&attr, (void**)bottom, size) != 0) {
185 fatal("Can not locate current stack attributes!");
186 }
187
188 pthread_attr_destroy(&attr);
189 }
190 assert(os::current_stack_pointer() >= *bottom &&
191 os::current_stack_pointer() < *bottom + *size, "just checking");
192 }
193
194 address os::current_stack_base() {
195 address bottom;
196 size_t size;
197 current_stack_region(&bottom, &size);
198 return bottom + size;
199 }
200
201 size_t os::current_stack_size() {
202 // stack size includes normal stack and HotSpot guard pages
203 address bottom;
204 size_t size;
205 current_stack_region(&bottom, &size);
206 return size;
207 }
208
209 char* os::non_memory_address_word() {
210 // Must never look like an address returned by reserve_memory,
211 // even in its subfields (as defined by the CPU immediate fields,
212 // if the CPU splits constants across multiple instructions).
213 // On SPARC, 0 != %hi(any real address), because there is no
214 // allocation in the first 1Kb of the virtual address space.
215 return (char*) 0;
216 }
217
218 void os::initialize_thread(Thread* thr) {}
219
220 void os::print_context(outputStream *st, void *context) {
221 if (context == NULL) return;
222
223 ucontext_t* uc = (ucontext_t*)context;
224 sigcontext* sc = (sigcontext*)context;
225 st->print_cr("Registers:");
226
227 st->print_cr(" G1=" INTPTR_FORMAT " G2=" INTPTR_FORMAT
228 " G3=" INTPTR_FORMAT " G4=" INTPTR_FORMAT,
229 SIG_REGS(sc).u_regs[CON_G1],
230 SIG_REGS(sc).u_regs[CON_G2],
231 SIG_REGS(sc).u_regs[CON_G3],
232 SIG_REGS(sc).u_regs[CON_G4]);
233 st->print_cr(" G5=" INTPTR_FORMAT " G6=" INTPTR_FORMAT
234 " G7=" INTPTR_FORMAT " Y=0x%x",
235 SIG_REGS(sc).u_regs[CON_G5],
236 SIG_REGS(sc).u_regs[CON_G6],
237 SIG_REGS(sc).u_regs[CON_G7],
238 SIG_REGS(sc).y);
239 st->print_cr(" O0=" INTPTR_FORMAT " O1=" INTPTR_FORMAT
240 " O2=" INTPTR_FORMAT " O3=" INTPTR_FORMAT,
241 SIG_REGS(sc).u_regs[CON_O0],
242 SIG_REGS(sc).u_regs[CON_O1],
243 SIG_REGS(sc).u_regs[CON_O2],
244 SIG_REGS(sc).u_regs[CON_O3]);
245 st->print_cr(" O4=" INTPTR_FORMAT " O5=" INTPTR_FORMAT
246 " O6=" INTPTR_FORMAT " O7=" INTPTR_FORMAT,
247 SIG_REGS(sc).u_regs[CON_O4],
248 SIG_REGS(sc).u_regs[CON_O5],
249 SIG_REGS(sc).u_regs[CON_O6],
250 SIG_REGS(sc).u_regs[CON_O7]);
251
252
253 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
254 st->print_cr(" L0=" INTPTR_FORMAT " L1=" INTPTR_FORMAT
255 " L2=" INTPTR_FORMAT " L3=" INTPTR_FORMAT,
256 sp[L0->sp_offset_in_saved_window()],
257 sp[L1->sp_offset_in_saved_window()],
258 sp[L2->sp_offset_in_saved_window()],
259 sp[L3->sp_offset_in_saved_window()]);
260 st->print_cr(" L4=" INTPTR_FORMAT " L5=" INTPTR_FORMAT
261 " L6=" INTPTR_FORMAT " L7=" INTPTR_FORMAT,
262 sp[L4->sp_offset_in_saved_window()],
263 sp[L5->sp_offset_in_saved_window()],
264 sp[L6->sp_offset_in_saved_window()],
265 sp[L7->sp_offset_in_saved_window()]);
266 st->print_cr(" I0=" INTPTR_FORMAT " I1=" INTPTR_FORMAT
267 " I2=" INTPTR_FORMAT " I3=" INTPTR_FORMAT,
268 sp[I0->sp_offset_in_saved_window()],
269 sp[I1->sp_offset_in_saved_window()],
270 sp[I2->sp_offset_in_saved_window()],
271 sp[I3->sp_offset_in_saved_window()]);
272 st->print_cr(" I4=" INTPTR_FORMAT " I5=" INTPTR_FORMAT
273 " I6=" INTPTR_FORMAT " I7=" INTPTR_FORMAT,
274 sp[I4->sp_offset_in_saved_window()],
275 sp[I5->sp_offset_in_saved_window()],
276 sp[I6->sp_offset_in_saved_window()],
277 sp[I7->sp_offset_in_saved_window()]);
278
279 st->print_cr(" PC=" INTPTR_FORMAT " nPC=" INTPTR_FORMAT,
280 SIG_PC(sc),
281 SIG_NPC(sc));
282 st->cr();
283 st->cr();
284
285 st->print_cr("Top of Stack: (sp=" INTPTR_FORMAT ")", p2i(sp));
286 print_hex_dump(st, (address)sp, (address)(sp + 32), sizeof(intptr_t));
287 st->cr();
288
289 // Note: it may be unsafe to inspect memory near pc. For example, pc may
290 // point to garbage if entry point in an nmethod is corrupted. Leave
291 // this at the end, and hope for the best.
292 address pc = os::Linux::ucontext_get_pc(uc);
293 st->print_cr("Instructions: (pc=" INTPTR_FORMAT ")", p2i(pc));
294 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
295 }
296
297
298 void os::print_register_info(outputStream *st, void *context) {
299 if (context == NULL) return;
300
301 ucontext_t *uc = (ucontext_t*)context;
302 sigcontext* sc = (sigcontext*)context;
303 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
304
305 st->print_cr("Register to memory mapping:");
306 st->cr();
307
308 // this is only for the "general purpose" registers
309 st->print("G1="); print_location(st, SIG_REGS(sc).u_regs[CON_G1]);
310 st->print("G2="); print_location(st, SIG_REGS(sc).u_regs[CON_G2]);
311 st->print("G3="); print_location(st, SIG_REGS(sc).u_regs[CON_G3]);
312 st->print("G4="); print_location(st, SIG_REGS(sc).u_regs[CON_G4]);
313 st->print("G5="); print_location(st, SIG_REGS(sc).u_regs[CON_G5]);
314 st->print("G6="); print_location(st, SIG_REGS(sc).u_regs[CON_G6]);
315 st->print("G7="); print_location(st, SIG_REGS(sc).u_regs[CON_G7]);
316 st->cr();
317
318 st->print("O0="); print_location(st, SIG_REGS(sc).u_regs[CON_O0]);
319 st->print("O1="); print_location(st, SIG_REGS(sc).u_regs[CON_O1]);
320 st->print("O2="); print_location(st, SIG_REGS(sc).u_regs[CON_O2]);
321 st->print("O3="); print_location(st, SIG_REGS(sc).u_regs[CON_O3]);
322 st->print("O4="); print_location(st, SIG_REGS(sc).u_regs[CON_O4]);
323 st->print("O5="); print_location(st, SIG_REGS(sc).u_regs[CON_O5]);
324 st->print("O6="); print_location(st, SIG_REGS(sc).u_regs[CON_O6]);
325 st->print("O7="); print_location(st, SIG_REGS(sc).u_regs[CON_O7]);
326 st->cr();
327
328 st->print("L0="); print_location(st, sp[L0->sp_offset_in_saved_window()]);
329 st->print("L1="); print_location(st, sp[L1->sp_offset_in_saved_window()]);
330 st->print("L2="); print_location(st, sp[L2->sp_offset_in_saved_window()]);
331 st->print("L3="); print_location(st, sp[L3->sp_offset_in_saved_window()]);
332 st->print("L4="); print_location(st, sp[L4->sp_offset_in_saved_window()]);
333 st->print("L5="); print_location(st, sp[L5->sp_offset_in_saved_window()]);
334 st->print("L6="); print_location(st, sp[L6->sp_offset_in_saved_window()]);
335 st->print("L7="); print_location(st, sp[L7->sp_offset_in_saved_window()]);
336 st->cr();
337
338 st->print("I0="); print_location(st, sp[I0->sp_offset_in_saved_window()]);
339 st->print("I1="); print_location(st, sp[I1->sp_offset_in_saved_window()]);
340 st->print("I2="); print_location(st, sp[I2->sp_offset_in_saved_window()]);
341 st->print("I3="); print_location(st, sp[I3->sp_offset_in_saved_window()]);
342 st->print("I4="); print_location(st, sp[I4->sp_offset_in_saved_window()]);
343 st->print("I5="); print_location(st, sp[I5->sp_offset_in_saved_window()]);
344 st->print("I6="); print_location(st, sp[I6->sp_offset_in_saved_window()]);
345 st->print("I7="); print_location(st, sp[I7->sp_offset_in_saved_window()]);
346 st->cr();
347 }
348
349
350 address os::Linux::ucontext_get_pc(ucontext_t* uc) {
351 return (address) SIG_PC((sigcontext*)uc);
352 }
353
354 void os::Linux::ucontext_set_pc(ucontext_t* uc, address pc) {
355 set_cont_address((sigcontext_t*) uc, pc);
356 }
357
358 intptr_t* os::Linux::ucontext_get_sp(ucontext_t *uc) {
359 return (intptr_t*)
360 ((intptr_t)SIG_REGS((sigcontext*)uc).u_regs[CON_O6] + STACK_BIAS);
361 }
362
363 // not used on Sparc
364 intptr_t* os::Linux::ucontext_get_fp(ucontext_t *uc) {
365 ShouldNotReachHere();
366 return NULL;
367 }
368
369 // Utility functions
370
371 inline static bool checkPrefetch(sigcontext* uc, address pc) {
372 if (StubRoutines::is_safefetch_fault(pc)) {
373 set_cont_address(uc, address(StubRoutines::continuation_for_safefetch_fault(pc)));
374 return true;
375 }
376 return false;
377 }
378
379 inline static bool checkOverflow(sigcontext* uc,
380 address pc,
381 address addr,
382 JavaThread* thread,
383 address* stub) {
384 // check if fault address is within thread stack
385 if (addr < thread->stack_base() &&
386 addr >= thread->stack_base() - thread->stack_size()) {
387 // stack overflow
388 if (thread->in_stack_yellow_zone(addr)) {
389 thread->disable_stack_yellow_zone();
390 if (thread->thread_state() == _thread_in_Java) {
391 // Throw a stack overflow exception. Guard pages will be reenabled
392 // while unwinding the stack.
393 *stub =
394 SharedRuntime::continuation_for_implicit_exception(thread,
395 pc,
396 SharedRuntime::STACK_OVERFLOW);
397 } else {
398 // Thread was in the vm or native code. Return and try to finish.
399 return true;
400 }
401 } else if (thread->in_stack_red_zone(addr)) {
402 // Fatal red zone violation. Disable the guard pages and fall through
403 // to handle_unexpected_exception way down below.
404 thread->disable_stack_red_zone();
405 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
406
407 // This is a likely cause, but hard to verify. Let's just print
408 // it as a hint.
409 tty->print_raw_cr("Please check if any of your loaded .so files has "
410 "enabled executable stack (see man page execstack(8))");
411 } else {
412 // Accessing stack address below sp may cause SEGV if current
413 // thread has MAP_GROWSDOWN stack. This should only happen when
414 // current thread was created by user code with MAP_GROWSDOWN flag
415 // and then attached to VM. See notes in os_linux.cpp.
416 if (thread->osthread()->expanding_stack() == 0) {
417 thread->osthread()->set_expanding_stack();
418 if (os::Linux::manually_expand_stack(thread, addr)) {
419 thread->osthread()->clear_expanding_stack();
420 return true;
421 }
422 thread->osthread()->clear_expanding_stack();
423 } else {
424 fatal("recursive segv. expanding stack.");
425 }
426 }
427 }
428 return false;
429 }
430
431 inline static bool checkPollingPage(address pc, address fault, address* stub) {
432 if (fault == os::get_polling_page()) {
433 *stub = SharedRuntime::get_poll_stub(pc);
434 return true;
435 }
436 return false;
437 }
438
439 inline static bool checkByteBuffer(address pc, address* stub) {
440 // BugId 4454115: A read from a MappedByteBuffer can fault
441 // here if the underlying file has been truncated.
442 // Do not crash the VM in such a case.
443 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
444 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
445 if (nm != NULL && nm->has_unsafe_access()) {
446 *stub = StubRoutines::handler_for_unsafe_access();
447 return true;
448 }
449 return false;
450 }
451
452 inline static bool checkVerifyOops(address pc, address fault, address* stub) {
453 if (pc >= MacroAssembler::_verify_oop_implicit_branch[0]
454 && pc < MacroAssembler::_verify_oop_implicit_branch[1] ) {
455 *stub = MacroAssembler::_verify_oop_implicit_branch[2];
456 warning("fixed up memory fault in +VerifyOops at address "
457 INTPTR_FORMAT, p2i(fault));
458 return true;
459 }
460 return false;
461 }
462
463 inline static bool checkFPFault(address pc, int code,
464 JavaThread* thread, address* stub) {
465 if (code == FPE_INTDIV || code == FPE_FLTDIV) {
466 *stub =
467 SharedRuntime::
468 continuation_for_implicit_exception(thread,
469 pc,
470 SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
471 return true;
472 }
473 return false;
474 }
475
476 inline static bool checkNullPointer(address pc, intptr_t fault,
477 JavaThread* thread, address* stub) {
478 if (!MacroAssembler::needs_explicit_null_check(fault)) {
479 // Determination of interpreter/vtable stub/compiled code null
480 // exception
481 *stub =
482 SharedRuntime::
483 continuation_for_implicit_exception(thread, pc,
484 SharedRuntime::IMPLICIT_NULL);
485 return true;
486 }
487 return false;
488 }
489
490 inline static bool checkFastJNIAccess(address pc, address* stub) {
491 address addr = JNI_FastGetField::find_slowcase_pc(pc);
492 if (addr != (address)-1) {
493 *stub = addr;
494 return true;
495 }
496 return false;
497 }
498
499 inline static bool checkSerializePage(JavaThread* thread, address addr) {
500 return os::is_memory_serialize_page(thread, addr);
501 }
502
503 inline static bool checkZombie(sigcontext* uc, address* pc, address* stub) {
504 if (nativeInstruction_at(*pc)->is_zombie()) {
505 // zombie method (ld [%g0],%o7 instruction)
506 *stub = SharedRuntime::get_handle_wrong_method_stub();
507
508 // At the stub it needs to look like a call from the caller of this
509 // method (not a call from the segv site).
510 *pc = (address)SIG_REGS(uc).u_regs[CON_O7];
511 return true;
512 }
513 return false;
514 }
515
516 inline static bool checkICMiss(sigcontext* uc, address* pc, address* stub) {
517 #ifdef COMPILER2
518 if (nativeInstruction_at(*pc)->is_ic_miss_trap()) {
519 #ifdef ASSERT
520 #ifdef TIERED
521 CodeBlob* cb = CodeCache::find_blob_unsafe(*pc);
522 assert(cb->is_compiled_by_c2(), "Wrong compiler");
523 #endif // TIERED
524 #endif // ASSERT
525 // Inline cache missed and user trap "Tne G0+ST_RESERVED_FOR_USER_0+2" taken.
526 *stub = SharedRuntime::get_ic_miss_stub();
527 // At the stub it needs to look like a call from the caller of this
528 // method (not a call from the segv site).
529 *pc = (address)SIG_REGS(uc).u_regs[CON_O7];
530 return true;
531 }
532 #endif // COMPILER2
533 return false;
534 }
535
536 extern "C" JNIEXPORT int
537 JVM_handle_linux_signal(int sig,
538 siginfo_t* info,
539 void* ucVoid,
540 int abort_if_unrecognized) {
541 // in fact this isn't ucontext_t* at all, but struct sigcontext*
542 // but Linux porting layer uses ucontext_t, so to minimize code change
543 // we cast as needed
544 ucontext_t* ucFake = (ucontext_t*) ucVoid;
545 sigcontext* uc = (sigcontext*)ucVoid;
546
547 Thread* t = ThreadLocalStorage::get_thread_slow();
548
549 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
550 // (no destructors can be run)
551 os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
552
553 SignalHandlerMark shm(t);
554
555 // Note: it's not uncommon that JNI code uses signal/sigset to install
556 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
557 // or have a SIGILL handler when detecting CPU type). When that happens,
558 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
559 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
560 // that do not require siginfo/ucontext first.
561
562 if (sig == SIGPIPE || sig == SIGXFSZ) {
563 // allow chained handler to go first
564 if (os::Linux::chained_handler(sig, info, ucVoid)) {
565 return true;
566 } else {
567 if (PrintMiscellaneous && (WizardMode || Verbose)) {
568 char buf[64];
569 warning("Ignoring %s - see bugs 4229104 or 646499219",
570 os::exception_name(sig, buf, sizeof(buf)));
571 }
572 return true;
573 }
574 }
575
576 JavaThread* thread = NULL;
577 VMThread* vmthread = NULL;
578 if (os::Linux::signal_handlers_are_installed) {
579 if (t != NULL ){
580 if(t->is_Java_thread()) {
581 thread = (JavaThread*)t;
582 }
583 else if(t->is_VM_thread()){
584 vmthread = (VMThread *)t;
585 }
586 }
587 }
588
589 // decide if this trap can be handled by a stub
590 address stub = NULL;
591 address pc = NULL;
592 address npc = NULL;
593
594 //%note os_trap_1
595 if (info != NULL && uc != NULL && thread != NULL) {
596 pc = address(SIG_PC(uc));
597 npc = address(SIG_NPC(uc));
598
599 // Check to see if we caught the safepoint code in the
600 // process of write protecting the memory serialization page.
601 // It write enables the page immediately after protecting it
602 // so we can just return to retry the write.
603 if ((sig == SIGSEGV) && checkSerializePage(thread, (address)info->si_addr)) {
604 // Block current thread until the memory serialize page permission restored.
605 os::block_on_serialize_page_trap();
606 return 1;
607 }
608
609 if (checkPrefetch(uc, pc)) {
610 return 1;
611 }
612
613 // Handle ALL stack overflow variations here
614 if (sig == SIGSEGV) {
615 if (checkOverflow(uc, pc, (address)info->si_addr, thread, &stub)) {
616 return 1;
617 }
618 }
619
620 if (sig == SIGBUS &&
621 thread->thread_state() == _thread_in_vm &&
622 thread->doing_unsafe_access()) {
623 stub = StubRoutines::handler_for_unsafe_access();
624 }
625
626 if (thread->thread_state() == _thread_in_Java) {
627 do {
628 // Java thread running in Java code => find exception handler if any
629 // a fault inside compiled code, the interpreter, or a stub
630
631 if ((sig == SIGSEGV) && checkPollingPage(pc, (address)info->si_addr, &stub)) {
632 break;
633 }
634
635 if ((sig == SIGBUS) && checkByteBuffer(pc, &stub)) {
636 break;
637 }
638
639 if ((sig == SIGSEGV || sig == SIGBUS) &&
640 checkVerifyOops(pc, (address)info->si_addr, &stub)) {
641 break;
642 }
643
644 if ((sig == SIGSEGV) && checkZombie(uc, &pc, &stub)) {
645 break;
646 }
647
648 if ((sig == SIGILL) && checkICMiss(uc, &pc, &stub)) {
649 break;
650 }
651
652 if ((sig == SIGFPE) && checkFPFault(pc, info->si_code, thread, &stub)) {
653 break;
654 }
655
656 if ((sig == SIGSEGV) &&
657 checkNullPointer(pc, (intptr_t)info->si_addr, thread, &stub)) {
658 break;
659 }
660 } while (0);
661
662 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
663 // and the heap gets shrunk before the field access.
664 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
665 checkFastJNIAccess(pc, &stub);
666 }
667 }
668
669 if (stub != NULL) {
670 // save all thread context in case we need to restore it
671 thread->set_saved_exception_pc(pc);
672 thread->set_saved_exception_npc(npc);
673 set_cont_address(uc, stub);
674 return true;
675 }
676 }
677
678 // signal-chaining
679 if (os::Linux::chained_handler(sig, info, ucVoid)) {
680 return true;
681 }
682
683 if (!abort_if_unrecognized) {
684 // caller wants another chance, so give it to him
685 return false;
686 }
687
688 if (pc == NULL && uc != NULL) {
689 pc = os::Linux::ucontext_get_pc((ucontext_t*)uc);
690 }
691
692 // unmask current signal
693 sigset_t newset;
694 sigemptyset(&newset);
695 sigaddset(&newset, sig);
696 sigprocmask(SIG_UNBLOCK, &newset, NULL);
697
698 VMError err(t, sig, pc, info, ucVoid);
699 err.report_and_die();
700
701 ShouldNotReachHere();
702 }
703
704 void os::Linux::init_thread_fpu_state(void) {
705 // Nothing to do
706 }
707
708 int os::Linux::get_fpu_control_word() {
709 return 0;
710 }
711
712 void os::Linux::set_fpu_control_word(int fpu) {
713 // nothing
714 }
715
716 bool os::is_allocatable(size_t bytes) {
717 #ifdef _LP64
718 return true;
719 #else
720 if (bytes < 2 * G) {
721 return true;
722 }
723
724 char* addr = reserve_memory(bytes, NULL);
725
726 if (addr != NULL) {
727 release_memory(addr, bytes);
728 }
729
730 return addr != NULL;
731 #endif // _LP64
732 }
733
734 ///////////////////////////////////////////////////////////////////////////////
735 // thread stack
736
737 size_t os::Linux::min_stack_allowed = 128 * K;
738
739 // pthread on Ubuntu is always in floating stack mode
740 bool os::Linux::supports_variable_stack_size() { return true; }
741
742 // return default stack size for thr_type
743 size_t os::Linux::default_stack_size(os::ThreadType thr_type) {
744 // default stack size (compiler thread needs larger stack)
745 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
746 return s;
747 }
748
749 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
750 // Creating guard page is very expensive. Java thread has HotSpot
751 // guard page, only enable glibc guard page for non-Java threads.
752 return (thr_type == java_thread ? 0 : page_size());
753 }
754
755 #ifndef PRODUCT
756 void os::verify_stack_alignment() {
757 }
758 #endif
759
760 int os::extra_bang_size_in_bytes() {
761 // SPARC does not require the additional stack bang.
762 return 0;
763 }