1 /*
2 * Copyright (c) 1999, 2016, 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/codeCache.hpp"
31 #include "code/icBuffer.hpp"
32 #include "code/vtableStubs.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "jvm_linux.h"
35 #include "memory/allocation.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 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is
89 // currently interrupted by SIGPROF.
90 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested
91 // signal frames. Currently we don't do that on Linux, so it's the
92 // same as os::fetch_frame_from_context().
93 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
94 const ucontext_t* uc,
95 intptr_t** ret_sp,
96 intptr_t** ret_fp) {
97 assert(thread != NULL, "just checking");
98 assert(ret_sp != NULL, "just checking");
99 assert(ret_fp != NULL, "just checking");
100
101 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
102 }
103
104 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
105 intptr_t** ret_sp,
106 intptr_t** ret_fp) {
107 const ucontext_t* uc = (const ucontext_t*) ucVoid;
108 ExtendedPC epc;
109
110 if (uc != NULL) {
111 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
112 if (ret_sp) {
113 *ret_sp = os::Linux::ucontext_get_sp(uc);
114 }
115 if (ret_fp) {
116 *ret_fp = (intptr_t*)NULL;
117 }
118 } else {
119 // construct empty ExtendedPC for return value checking
120 epc = ExtendedPC(NULL);
121 if (ret_sp) {
122 *ret_sp = (intptr_t*) NULL;
123 }
124 if (ret_fp) {
125 *ret_fp = (intptr_t*) NULL;
126 }
127 }
128
129 return epc;
130 }
131
132 frame os::fetch_frame_from_context(const void* ucVoid) {
133 intptr_t* sp;
134 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, NULL);
135 return frame(sp, frame::unpatchable, epc.pc());
136 }
137
138 frame os::get_sender_for_C_frame(frame* fr) {
139 return frame(fr->sender_sp(), frame::unpatchable, fr->sender_pc());
140 }
141
142 frame os::current_frame() {
143 intptr_t* sp = StubRoutines::Sparc::flush_callers_register_windows_func()();
144 frame myframe(sp, frame::unpatchable,
145 CAST_FROM_FN_PTR(address, os::current_frame));
146 if (os::is_first_C_frame(&myframe)) {
147 // stack is not walkable
148 return frame(NULL, frame::unpatchable, NULL);
149 } else {
150 return os::get_sender_for_C_frame(&myframe);
151 }
152 }
153
154 address os::current_stack_pointer() {
155 register void *sp __asm__ ("sp");
156 return (address)sp;
157 }
158
159 static void current_stack_region(address* bottom, size_t* size) {
160 if (os::Linux::is_initial_thread()) {
161 // initial thread needs special handling because pthread_getattr_np()
162 // may return bogus value.
163 *bottom = os::Linux::initial_thread_stack_bottom();
164 *size = os::Linux::initial_thread_stack_size();
165 } else {
166 pthread_attr_t attr;
167
168 int rslt = pthread_getattr_np(pthread_self(), &attr);
169
170 // JVM needs to know exact stack location, abort if it fails
171 if (rslt != 0) {
172 if (rslt == ENOMEM) {
173 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
174 } else {
175 fatal("pthread_getattr_np failed with errno = %d", rslt);
176 }
177 }
178
179 if (pthread_attr_getstack(&attr, (void**)bottom, size) != 0) {
180 fatal("Can not locate current stack attributes!");
181 }
182
183 // Work around NPTL stack guard error.
184 size_t guard_size = 0;
185 pthread_attr_getguardsize(&attr, &guard_size);
186 *bottom += guard_size;
187 *size -= guard_size;
188
189 pthread_attr_destroy(&attr);
190 }
191 assert(os::current_stack_pointer() >= *bottom &&
192 os::current_stack_pointer() < *bottom + *size, "just checking");
193 }
194
195 address os::current_stack_base() {
196 address bottom;
197 size_t size;
198 current_stack_region(&bottom, &size);
199 return bottom + size;
200 }
201
202 size_t os::current_stack_size() {
203 // stack size includes normal stack and HotSpot guard pages
204 address bottom;
205 size_t size;
206 current_stack_region(&bottom, &size);
207 return size;
208 }
209
210 char* os::non_memory_address_word() {
211 // Must never look like an address returned by reserve_memory,
212 // even in its subfields (as defined by the CPU immediate fields,
213 // if the CPU splits constants across multiple instructions).
214 // On SPARC, 0 != %hi(any real address), because there is no
215 // allocation in the first 1Kb of the virtual address space.
216 return (char*) 0;
217 }
218
219 void os::initialize_thread(Thread* thr) {}
220
221 void os::print_context(outputStream *st, const void *context) {
222 if (context == NULL) return;
223
224 const ucontext_t* uc = (const ucontext_t*)context;
225 sigcontext* sc = (sigcontext*)context;
226 st->print_cr("Registers:");
227
228 st->print_cr(" G1=" INTPTR_FORMAT " G2=" INTPTR_FORMAT
229 " G3=" INTPTR_FORMAT " G4=" INTPTR_FORMAT,
230 SIG_REGS(sc).u_regs[CON_G1],
231 SIG_REGS(sc).u_regs[CON_G2],
232 SIG_REGS(sc).u_regs[CON_G3],
233 SIG_REGS(sc).u_regs[CON_G4]);
234 st->print_cr(" G5=" INTPTR_FORMAT " G6=" INTPTR_FORMAT
235 " G7=" INTPTR_FORMAT " Y=0x%x",
236 SIG_REGS(sc).u_regs[CON_G5],
237 SIG_REGS(sc).u_regs[CON_G6],
238 SIG_REGS(sc).u_regs[CON_G7],
239 SIG_REGS(sc).y);
240 st->print_cr(" O0=" INTPTR_FORMAT " O1=" INTPTR_FORMAT
241 " O2=" INTPTR_FORMAT " O3=" INTPTR_FORMAT,
242 SIG_REGS(sc).u_regs[CON_O0],
243 SIG_REGS(sc).u_regs[CON_O1],
244 SIG_REGS(sc).u_regs[CON_O2],
245 SIG_REGS(sc).u_regs[CON_O3]);
246 st->print_cr(" O4=" INTPTR_FORMAT " O5=" INTPTR_FORMAT
247 " O6=" INTPTR_FORMAT " O7=" INTPTR_FORMAT,
248 SIG_REGS(sc).u_regs[CON_O4],
249 SIG_REGS(sc).u_regs[CON_O5],
250 SIG_REGS(sc).u_regs[CON_O6],
251 SIG_REGS(sc).u_regs[CON_O7]);
252
253
254 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
255 st->print_cr(" L0=" INTPTR_FORMAT " L1=" INTPTR_FORMAT
256 " L2=" INTPTR_FORMAT " L3=" INTPTR_FORMAT,
257 sp[L0->sp_offset_in_saved_window()],
258 sp[L1->sp_offset_in_saved_window()],
259 sp[L2->sp_offset_in_saved_window()],
260 sp[L3->sp_offset_in_saved_window()]);
261 st->print_cr(" L4=" INTPTR_FORMAT " L5=" INTPTR_FORMAT
262 " L6=" INTPTR_FORMAT " L7=" INTPTR_FORMAT,
263 sp[L4->sp_offset_in_saved_window()],
264 sp[L5->sp_offset_in_saved_window()],
265 sp[L6->sp_offset_in_saved_window()],
266 sp[L7->sp_offset_in_saved_window()]);
267 st->print_cr(" I0=" INTPTR_FORMAT " I1=" INTPTR_FORMAT
268 " I2=" INTPTR_FORMAT " I3=" INTPTR_FORMAT,
269 sp[I0->sp_offset_in_saved_window()],
270 sp[I1->sp_offset_in_saved_window()],
271 sp[I2->sp_offset_in_saved_window()],
272 sp[I3->sp_offset_in_saved_window()]);
273 st->print_cr(" I4=" INTPTR_FORMAT " I5=" INTPTR_FORMAT
274 " I6=" INTPTR_FORMAT " I7=" INTPTR_FORMAT,
275 sp[I4->sp_offset_in_saved_window()],
276 sp[I5->sp_offset_in_saved_window()],
277 sp[I6->sp_offset_in_saved_window()],
278 sp[I7->sp_offset_in_saved_window()]);
279
280 st->print_cr(" PC=" INTPTR_FORMAT " nPC=" INTPTR_FORMAT,
281 SIG_PC(sc),
282 SIG_NPC(sc));
283 st->cr();
284 st->cr();
285
286 st->print_cr("Top of Stack: (sp=" INTPTR_FORMAT ")", p2i(sp));
287 print_hex_dump(st, (address)sp, (address)(sp + 32), sizeof(intptr_t));
288 st->cr();
289
290 // Note: it may be unsafe to inspect memory near pc. For example, pc may
291 // point to garbage if entry point in an nmethod is corrupted. Leave
292 // this at the end, and hope for the best.
293 address pc = os::Linux::ucontext_get_pc(uc);
294 st->print_cr("Instructions: (pc=" INTPTR_FORMAT ")", p2i(pc));
295 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
296 }
297
298
299 void os::print_register_info(outputStream *st, const void *context) {
300 if (context == NULL) return;
301
302 const ucontext_t *uc = (const ucontext_t*)context;
303 const sigcontext* sc = (const sigcontext*)context;
304 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
305
306 st->print_cr("Register to memory mapping:");
307 st->cr();
308
309 // this is only for the "general purpose" registers
310 st->print("G1="); print_location(st, SIG_REGS(sc).u_regs[CON_G1]);
311 st->print("G2="); print_location(st, SIG_REGS(sc).u_regs[CON_G2]);
312 st->print("G3="); print_location(st, SIG_REGS(sc).u_regs[CON_G3]);
313 st->print("G4="); print_location(st, SIG_REGS(sc).u_regs[CON_G4]);
314 st->print("G5="); print_location(st, SIG_REGS(sc).u_regs[CON_G5]);
315 st->print("G6="); print_location(st, SIG_REGS(sc).u_regs[CON_G6]);
316 st->print("G7="); print_location(st, SIG_REGS(sc).u_regs[CON_G7]);
317 st->cr();
318
319 st->print("O0="); print_location(st, SIG_REGS(sc).u_regs[CON_O0]);
320 st->print("O1="); print_location(st, SIG_REGS(sc).u_regs[CON_O1]);
321 st->print("O2="); print_location(st, SIG_REGS(sc).u_regs[CON_O2]);
322 st->print("O3="); print_location(st, SIG_REGS(sc).u_regs[CON_O3]);
323 st->print("O4="); print_location(st, SIG_REGS(sc).u_regs[CON_O4]);
324 st->print("O5="); print_location(st, SIG_REGS(sc).u_regs[CON_O5]);
325 st->print("O6="); print_location(st, SIG_REGS(sc).u_regs[CON_O6]);
326 st->print("O7="); print_location(st, SIG_REGS(sc).u_regs[CON_O7]);
327 st->cr();
328
329 st->print("L0="); print_location(st, sp[L0->sp_offset_in_saved_window()]);
330 st->print("L1="); print_location(st, sp[L1->sp_offset_in_saved_window()]);
331 st->print("L2="); print_location(st, sp[L2->sp_offset_in_saved_window()]);
332 st->print("L3="); print_location(st, sp[L3->sp_offset_in_saved_window()]);
333 st->print("L4="); print_location(st, sp[L4->sp_offset_in_saved_window()]);
334 st->print("L5="); print_location(st, sp[L5->sp_offset_in_saved_window()]);
335 st->print("L6="); print_location(st, sp[L6->sp_offset_in_saved_window()]);
336 st->print("L7="); print_location(st, sp[L7->sp_offset_in_saved_window()]);
337 st->cr();
338
339 st->print("I0="); print_location(st, sp[I0->sp_offset_in_saved_window()]);
340 st->print("I1="); print_location(st, sp[I1->sp_offset_in_saved_window()]);
341 st->print("I2="); print_location(st, sp[I2->sp_offset_in_saved_window()]);
342 st->print("I3="); print_location(st, sp[I3->sp_offset_in_saved_window()]);
343 st->print("I4="); print_location(st, sp[I4->sp_offset_in_saved_window()]);
344 st->print("I5="); print_location(st, sp[I5->sp_offset_in_saved_window()]);
345 st->print("I6="); print_location(st, sp[I6->sp_offset_in_saved_window()]);
346 st->print("I7="); print_location(st, sp[I7->sp_offset_in_saved_window()]);
347 st->cr();
348 }
349
350
351 address os::Linux::ucontext_get_pc(const ucontext_t* uc) {
352 return (address) SIG_PC((sigcontext*)uc);
353 }
354
355 void os::Linux::ucontext_set_pc(ucontext_t* uc, address pc) {
356 sigcontext* ctx = (sigcontext*) uc;
357 SIG_PC(ctx) = (intptr_t)pc;
358 SIG_NPC(ctx) = (intptr_t)(pc+4);
359 }
360
361 intptr_t* os::Linux::ucontext_get_sp(const ucontext_t *uc) {
362 return (intptr_t*)
363 ((intptr_t)SIG_REGS((sigcontext*)uc).u_regs[CON_O6] + STACK_BIAS);
364 }
365
366 // not used on Sparc
367 intptr_t* os::Linux::ucontext_get_fp(const ucontext_t *uc) {
368 ShouldNotReachHere();
369 return NULL;
370 }
371
372 // Utility functions
373
374 inline static bool checkPrefetch(sigcontext* uc, address pc) {
375 if (StubRoutines::is_safefetch_fault(pc)) {
376 os::Linux::ucontext_set_pc((ucontext_t*)uc, StubRoutines::continuation_for_safefetch_fault(pc));
377 return true;
378 }
379 return false;
380 }
381
382 inline static bool checkOverflow(sigcontext* uc,
383 address pc,
384 address addr,
385 JavaThread* thread,
386 address* stub) {
387 // check if fault address is within thread stack
388 if (thread->on_local_stack(addr)) {
389 // stack overflow
390 if (thread->in_stack_yellow_reserved_zone(addr)) {
391 thread->disable_stack_yellow_reserved_zone();
392 if (thread->thread_state() == _thread_in_Java) {
393 // Throw a stack overflow exception. Guard pages will be reenabled
394 // while unwinding the stack.
395 *stub =
396 SharedRuntime::continuation_for_implicit_exception(thread,
397 pc,
398 SharedRuntime::STACK_OVERFLOW);
399 } else {
400 // Thread was in the vm or native code. Return and try to finish.
401 return true;
402 }
403 } else if (thread->in_stack_red_zone(addr)) {
404 // Fatal red zone violation. Disable the guard pages and fall through
405 // to handle_unexpected_exception way down below.
406 thread->disable_stack_red_zone();
407 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
408
409 // This is a likely cause, but hard to verify. Let's just print
410 // it as a hint.
411 tty->print_raw_cr("Please check if any of your loaded .so files has "
412 "enabled executable stack (see man page execstack(8))");
413 } else {
414 // Accessing stack address below sp may cause SEGV if current
415 // thread has MAP_GROWSDOWN stack. This should only happen when
416 // current thread was created by user code with MAP_GROWSDOWN flag
417 // and then attached to VM. See notes in os_linux.cpp.
418 if (thread->osthread()->expanding_stack() == 0) {
419 thread->osthread()->set_expanding_stack();
420 if (os::Linux::manually_expand_stack(thread, addr)) {
421 thread->osthread()->clear_expanding_stack();
422 return true;
423 }
424 thread->osthread()->clear_expanding_stack();
425 } else {
426 fatal("recursive segv. expanding stack.");
427 }
428 }
429 }
430 return false;
431 }
432
433 inline static bool checkPollingPage(address pc, address fault, address* stub) {
434 if (fault == os::get_polling_page()) {
435 *stub = SharedRuntime::get_poll_stub(pc);
436 return true;
437 }
438 return false;
439 }
440
441 inline static bool checkByteBuffer(address pc, address npc, address* stub) {
442 // BugId 4454115: A read from a MappedByteBuffer can fault
443 // here if the underlying file has been truncated.
444 // Do not crash the VM in such a case.
445 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
446 CompiledMethod* nm = cb->as_compiled_method_or_null();
447 if (nm != NULL && nm->has_unsafe_access()) {
448 *stub = SharedRuntime::handle_unsafe_access(thread, npc);
449 return true;
450 }
451 return false;
452 }
453
454 inline static bool checkVerifyOops(address pc, address fault, address* stub) {
455 if (pc >= MacroAssembler::_verify_oop_implicit_branch[0]
456 && pc < MacroAssembler::_verify_oop_implicit_branch[1] ) {
457 *stub = MacroAssembler::_verify_oop_implicit_branch[2];
458 warning("fixed up memory fault in +VerifyOops at address "
459 INTPTR_FORMAT, p2i(fault));
460 return true;
461 }
462 return false;
463 }
464
465 inline static bool checkFPFault(address pc, int code,
466 JavaThread* thread, address* stub) {
467 if (code == FPE_INTDIV || code == FPE_FLTDIV) {
468 *stub =
469 SharedRuntime::
470 continuation_for_implicit_exception(thread,
471 pc,
472 SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
473 return true;
474 }
475 return false;
476 }
477
478 inline static bool checkNullPointer(address pc, intptr_t fault,
479 JavaThread* thread, address* stub) {
480 if (!MacroAssembler::needs_explicit_null_check(fault)) {
481 // Determination of interpreter/vtable stub/compiled code null
482 // exception
483 *stub =
484 SharedRuntime::
485 continuation_for_implicit_exception(thread, pc,
486 SharedRuntime::IMPLICIT_NULL);
487 return true;
488 }
489 return false;
490 }
491
492 inline static bool checkFastJNIAccess(address pc, address* stub) {
493 address addr = JNI_FastGetField::find_slowcase_pc(pc);
494 if (addr != (address)-1) {
495 *stub = addr;
496 return true;
497 }
498 return false;
499 }
500
501 inline static bool checkSerializePage(JavaThread* thread, address addr) {
502 return os::is_memory_serialize_page(thread, addr);
503 }
504
505 inline static bool checkZombie(sigcontext* uc, address* pc, address* stub) {
506 if (nativeInstruction_at(*pc)->is_zombie()) {
507 // zombie method (ld [%g0],%o7 instruction)
508 *stub = SharedRuntime::get_handle_wrong_method_stub();
509
510 // At the stub it needs to look like a call from the caller of this
511 // method (not a call from the segv site).
512 *pc = (address)SIG_REGS(uc).u_regs[CON_O7];
513 return true;
514 }
515 return false;
516 }
517
518 inline static bool checkICMiss(sigcontext* uc, address* pc, address* stub) {
519 #ifdef COMPILER2
520 if (nativeInstruction_at(*pc)->is_ic_miss_trap()) {
521 #ifdef ASSERT
522 #ifdef TIERED
523 CodeBlob* cb = CodeCache::find_blob_unsafe(*pc);
524 assert(cb->is_compiled_by_c2(), "Wrong compiler");
525 #endif // TIERED
526 #endif // ASSERT
527 // Inline cache missed and user trap "Tne G0+ST_RESERVED_FOR_USER_0+2" taken.
528 *stub = SharedRuntime::get_ic_miss_stub();
529 // At the stub it needs to look like a call from the caller of this
530 // method (not a call from the segv site).
531 *pc = (address)SIG_REGS(uc).u_regs[CON_O7];
532 return true;
533 }
534 #endif // COMPILER2
535 return false;
536 }
537
538 extern "C" JNIEXPORT int
539 JVM_handle_linux_signal(int sig,
540 siginfo_t* info,
541 void* ucVoid,
542 int abort_if_unrecognized) {
543 // in fact this isn't ucontext_t* at all, but struct sigcontext*
544 // but Linux porting layer uses ucontext_t, so to minimize code change
545 // we cast as needed
546 ucontext_t* ucFake = (ucontext_t*) ucVoid;
547 sigcontext* uc = (sigcontext*)ucVoid;
548
549 Thread* t = Thread::current_or_null_safe();
550
551 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
552 // (no destructors can be run)
553 os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
554
555 SignalHandlerMark shm(t);
556
557 // Note: it's not uncommon that JNI code uses signal/sigset to install
558 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
559 // or have a SIGILL handler when detecting CPU type). When that happens,
560 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
561 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
562 // that do not require siginfo/ucontext first.
563
564 if (sig == SIGPIPE || sig == SIGXFSZ) {
565 // allow chained handler to go first
566 if (os::Linux::chained_handler(sig, info, ucVoid)) {
567 return true;
568 } else {
569 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
570 return true;
571 }
572 }
573
574 JavaThread* thread = NULL;
575 VMThread* vmthread = NULL;
576 if (os::Linux::signal_handlers_are_installed) {
577 if (t != NULL ){
578 if(t->is_Java_thread()) {
579 thread = (JavaThread*)t;
580 }
581 else if(t->is_VM_thread()){
582 vmthread = (VMThread *)t;
583 }
584 }
585 }
586
587 // decide if this trap can be handled by a stub
588 address stub = NULL;
589 address pc = NULL;
590 address npc = NULL;
591
592 //%note os_trap_1
593 if (info != NULL && uc != NULL && thread != NULL) {
594 pc = address(SIG_PC(uc));
595 npc = address(SIG_NPC(uc));
596
597 // Check to see if we caught the safepoint code in the
598 // process of write protecting the memory serialization page.
599 // It write enables the page immediately after protecting it
600 // so we can just return to retry the write.
601 if ((sig == SIGSEGV) && checkSerializePage(thread, (address)info->si_addr)) {
602 // Block current thread until the memory serialize page permission restored.
603 os::block_on_serialize_page_trap();
604 return 1;
605 }
606
607 if (checkPrefetch(uc, pc)) {
608 return 1;
609 }
610
611 // Handle ALL stack overflow variations here
612 if (sig == SIGSEGV) {
613 if (checkOverflow(uc, pc, (address)info->si_addr, thread, &stub)) {
614 return 1;
615 }
616 }
617
618 if (sig == SIGBUS &&
619 thread->thread_state() == _thread_in_vm &&
620 thread->doing_unsafe_access()) {
621 stub = SharedRuntime::handle_unsafe_access(thread, npc);
622 }
623
624 if (thread->thread_state() == _thread_in_Java) {
625 do {
626 // Java thread running in Java code => find exception handler if any
627 // a fault inside compiled code, the interpreter, or a stub
628
629 if ((sig == SIGSEGV) && checkPollingPage(pc, (address)info->si_addr, &stub)) {
630 break;
631 }
632
633 if ((sig == SIGBUS) && checkByteBuffer(pc, npc, &stub)) {
634 break;
635 }
636
637 if ((sig == SIGSEGV || sig == SIGBUS) &&
638 checkVerifyOops(pc, (address)info->si_addr, &stub)) {
639 break;
640 }
641
642 if ((sig == SIGSEGV) && checkZombie(uc, &pc, &stub)) {
643 break;
644 }
645
646 if ((sig == SIGILL) && checkICMiss(uc, &pc, &stub)) {
647 break;
648 }
649
650 if ((sig == SIGFPE) && checkFPFault(pc, info->si_code, thread, &stub)) {
651 break;
652 }
653
654 if ((sig == SIGSEGV) &&
655 checkNullPointer(pc, (intptr_t)info->si_addr, thread, &stub)) {
656 break;
657 }
658 } while (0);
659
660 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
661 // and the heap gets shrunk before the field access.
662 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
663 checkFastJNIAccess(pc, &stub);
664 }
665 }
666
667 if (stub != NULL) {
668 // save all thread context in case we need to restore it
669 thread->set_saved_exception_pc(pc);
670 thread->set_saved_exception_npc(npc);
671 os::Linux::ucontext_set_pc((ucontext_t*)uc, stub);
672 return true;
673 }
674 }
675
676 // signal-chaining
677 if (os::Linux::chained_handler(sig, info, ucVoid)) {
678 return true;
679 }
680
681 if (!abort_if_unrecognized) {
682 // caller wants another chance, so give it to him
683 return false;
684 }
685
686 if (pc == NULL && uc != NULL) {
687 pc = os::Linux::ucontext_get_pc((const ucontext_t*)uc);
688 }
689
690 // unmask current signal
691 sigset_t newset;
692 sigemptyset(&newset);
693 sigaddset(&newset, sig);
694 sigprocmask(SIG_UNBLOCK, &newset, NULL);
695
696 VMError::report_and_die(t, sig, pc, info, ucVoid);
697
698 ShouldNotReachHere();
699 return false;
700 }
701
702 void os::Linux::init_thread_fpu_state(void) {
703 // Nothing to do
704 }
705
706 int os::Linux::get_fpu_control_word() {
707 return 0;
708 }
709
710 void os::Linux::set_fpu_control_word(int fpu) {
711 // nothing
712 }
713
714 bool os::is_allocatable(size_t bytes) {
715 #ifdef _LP64
716 return true;
717 #else
718 if (bytes < 2 * G) {
719 return true;
720 }
721
722 char* addr = reserve_memory(bytes, NULL);
723
724 if (addr != NULL) {
725 release_memory(addr, bytes);
726 }
727
728 return addr != NULL;
729 #endif // _LP64
730 }
731
732 ///////////////////////////////////////////////////////////////////////////////
733 // thread stack
734
735 // These sizes exclude OS stack guard pages, but include
736 // the VM guard pages.
737 size_t os::Posix::_compiler_thread_min_stack_allowed = 32 * K;
738 size_t os::Posix::_java_thread_min_stack_allowed = 32 * K;
739 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 128 * K;
740
741 // return default stack size for thr_type
742 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
743 // default stack size (compiler thread needs larger stack)
744 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
745 return s;
746 }
747
748 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
749 // Creating guard page is very expensive. Java thread has HotSpot
750 // guard page, only enable glibc guard page for non-Java threads.
751 return ((thr_type == java_thread || thr_type == os::compiler_thread) ? 0 : page_size());
752 }
753
754 #ifndef PRODUCT
755 void os::verify_stack_alignment() {
756 }
757 #endif
758
759 int os::extra_bang_size_in_bytes() {
760 // SPARC does not require the additional stack bang.
761 return 0;
762 }