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_bsd.h"
35 #include "memory/allocation.inline.hpp"
36 #include "os_share_bsd.hpp"
37 #include "prims/jniFastGetField.hpp"
38 #include "prims/jvm.h"
39 #include "prims/jvm_misc.hpp"
40 #include "runtime/arguments.hpp"
41 #include "runtime/extendedPC.hpp"
42 #include "runtime/frame.inline.hpp"
43 #include "runtime/interfaceSupport.hpp"
44 #include "runtime/java.hpp"
45 #include "runtime/javaCalls.hpp"
46 #include "runtime/mutexLocker.hpp"
47 #include "runtime/osThread.hpp"
48 #include "runtime/sharedRuntime.hpp"
49 #include "runtime/stubRoutines.hpp"
50 #include "runtime/thread.inline.hpp"
51 #include "runtime/timer.hpp"
52 #include "utilities/events.hpp"
53 #include "utilities/vmError.hpp"
54
55 // put OS-includes here
56 # include <sys/types.h>
57 # include <sys/mman.h>
58 # include <pthread.h>
59 # include <signal.h>
60 # include <errno.h>
61 # include <dlfcn.h>
62 # include <stdlib.h>
63 # include <stdio.h>
64 # include <unistd.h>
65 # include <sys/resource.h>
66 # include <pthread.h>
67 # include <sys/stat.h>
68 # include <sys/time.h>
69 # include <sys/utsname.h>
70 # include <sys/socket.h>
71 # include <sys/wait.h>
72 # include <pwd.h>
73 # include <poll.h>
74 #ifndef __OpenBSD__
75 # include <ucontext.h>
76 #endif
77
78 #if !defined(__APPLE__) && !defined(__NetBSD__)
79 # include <pthread_np.h>
80 #endif
81
82 // needed by current_stack_region() workaround for Mavericks
83 #if defined(__APPLE__)
84 # include <errno.h>
85 # include <sys/types.h>
86 # include <sys/sysctl.h>
87 # define DEFAULT_MAIN_THREAD_STACK_PAGES 2048
88 # define OS_X_10_9_0_KERNEL_MAJOR_VERSION 13
89 #endif
90
91 #ifdef AMD64
92 #define SPELL_REG_SP "rsp"
93 #define SPELL_REG_FP "rbp"
94 #else
95 #define SPELL_REG_SP "esp"
96 #define SPELL_REG_FP "ebp"
97 #endif // AMD64
98
99 #ifdef __FreeBSD__
100 # define context_trapno uc_mcontext.mc_trapno
101 # ifdef AMD64
102 # define context_pc uc_mcontext.mc_rip
103 # define context_sp uc_mcontext.mc_rsp
104 # define context_fp uc_mcontext.mc_rbp
105 # define context_rip uc_mcontext.mc_rip
106 # define context_rsp uc_mcontext.mc_rsp
107 # define context_rbp uc_mcontext.mc_rbp
108 # define context_rax uc_mcontext.mc_rax
109 # define context_rbx uc_mcontext.mc_rbx
110 # define context_rcx uc_mcontext.mc_rcx
111 # define context_rdx uc_mcontext.mc_rdx
112 # define context_rsi uc_mcontext.mc_rsi
113 # define context_rdi uc_mcontext.mc_rdi
114 # define context_r8 uc_mcontext.mc_r8
115 # define context_r9 uc_mcontext.mc_r9
116 # define context_r10 uc_mcontext.mc_r10
117 # define context_r11 uc_mcontext.mc_r11
118 # define context_r12 uc_mcontext.mc_r12
119 # define context_r13 uc_mcontext.mc_r13
120 # define context_r14 uc_mcontext.mc_r14
121 # define context_r15 uc_mcontext.mc_r15
122 # define context_flags uc_mcontext.mc_flags
123 # define context_err uc_mcontext.mc_err
124 # else
125 # define context_pc uc_mcontext.mc_eip
126 # define context_sp uc_mcontext.mc_esp
127 # define context_fp uc_mcontext.mc_ebp
128 # define context_eip uc_mcontext.mc_eip
129 # define context_esp uc_mcontext.mc_esp
130 # define context_eax uc_mcontext.mc_eax
131 # define context_ebx uc_mcontext.mc_ebx
132 # define context_ecx uc_mcontext.mc_ecx
133 # define context_edx uc_mcontext.mc_edx
134 # define context_ebp uc_mcontext.mc_ebp
135 # define context_esi uc_mcontext.mc_esi
136 # define context_edi uc_mcontext.mc_edi
137 # define context_eflags uc_mcontext.mc_eflags
138 # define context_trapno uc_mcontext.mc_trapno
139 # endif
140 #endif
141
142 #ifdef __APPLE__
143 # if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
144 // 10.5 UNIX03 member name prefixes
145 #define DU3_PREFIX(s, m) __ ## s.__ ## m
146 # else
147 #define DU3_PREFIX(s, m) s ## . ## m
148 # endif
149
150 # ifdef AMD64
151 # define context_pc context_rip
152 # define context_sp context_rsp
153 # define context_fp context_rbp
154 # define context_rip uc_mcontext->DU3_PREFIX(ss,rip)
155 # define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp)
156 # define context_rax uc_mcontext->DU3_PREFIX(ss,rax)
157 # define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx)
158 # define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx)
159 # define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx)
160 # define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp)
161 # define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi)
162 # define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi)
163 # define context_r8 uc_mcontext->DU3_PREFIX(ss,r8)
164 # define context_r9 uc_mcontext->DU3_PREFIX(ss,r9)
165 # define context_r10 uc_mcontext->DU3_PREFIX(ss,r10)
166 # define context_r11 uc_mcontext->DU3_PREFIX(ss,r11)
167 # define context_r12 uc_mcontext->DU3_PREFIX(ss,r12)
168 # define context_r13 uc_mcontext->DU3_PREFIX(ss,r13)
169 # define context_r14 uc_mcontext->DU3_PREFIX(ss,r14)
170 # define context_r15 uc_mcontext->DU3_PREFIX(ss,r15)
171 # define context_flags uc_mcontext->DU3_PREFIX(ss,rflags)
172 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno)
173 # define context_err uc_mcontext->DU3_PREFIX(es,err)
174 # else
175 # define context_pc context_eip
176 # define context_sp context_esp
177 # define context_fp context_ebp
178 # define context_eip uc_mcontext->DU3_PREFIX(ss,eip)
179 # define context_esp uc_mcontext->DU3_PREFIX(ss,esp)
180 # define context_eax uc_mcontext->DU3_PREFIX(ss,eax)
181 # define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx)
182 # define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx)
183 # define context_edx uc_mcontext->DU3_PREFIX(ss,edx)
184 # define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp)
185 # define context_esi uc_mcontext->DU3_PREFIX(ss,esi)
186 # define context_edi uc_mcontext->DU3_PREFIX(ss,edi)
187 # define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags)
188 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno)
189 # endif
190 #endif
191
192 #ifdef __OpenBSD__
193 # define context_trapno sc_trapno
194 # ifdef AMD64
195 # define context_pc sc_rip
196 # define context_sp sc_rsp
197 # define context_fp sc_rbp
198 # define context_rip sc_rip
199 # define context_rsp sc_rsp
200 # define context_rbp sc_rbp
201 # define context_rax sc_rax
202 # define context_rbx sc_rbx
203 # define context_rcx sc_rcx
204 # define context_rdx sc_rdx
205 # define context_rsi sc_rsi
206 # define context_rdi sc_rdi
207 # define context_r8 sc_r8
208 # define context_r9 sc_r9
209 # define context_r10 sc_r10
210 # define context_r11 sc_r11
211 # define context_r12 sc_r12
212 # define context_r13 sc_r13
213 # define context_r14 sc_r14
214 # define context_r15 sc_r15
215 # define context_flags sc_rflags
216 # define context_err sc_err
217 # else
218 # define context_pc sc_eip
219 # define context_sp sc_esp
220 # define context_fp sc_ebp
221 # define context_eip sc_eip
222 # define context_esp sc_esp
223 # define context_eax sc_eax
224 # define context_ebx sc_ebx
225 # define context_ecx sc_ecx
226 # define context_edx sc_edx
227 # define context_ebp sc_ebp
228 # define context_esi sc_esi
229 # define context_edi sc_edi
230 # define context_eflags sc_eflags
231 # define context_trapno sc_trapno
232 # endif
233 #endif
234
235 #ifdef __NetBSD__
236 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO]
237 # ifdef AMD64
238 # define __register_t __greg_t
239 # define context_pc uc_mcontext.__gregs[_REG_RIP]
240 # define context_sp uc_mcontext.__gregs[_REG_URSP]
241 # define context_fp uc_mcontext.__gregs[_REG_RBP]
242 # define context_rip uc_mcontext.__gregs[_REG_RIP]
243 # define context_rsp uc_mcontext.__gregs[_REG_URSP]
244 # define context_rax uc_mcontext.__gregs[_REG_RAX]
245 # define context_rbx uc_mcontext.__gregs[_REG_RBX]
246 # define context_rcx uc_mcontext.__gregs[_REG_RCX]
247 # define context_rdx uc_mcontext.__gregs[_REG_RDX]
248 # define context_rbp uc_mcontext.__gregs[_REG_RBP]
249 # define context_rsi uc_mcontext.__gregs[_REG_RSI]
250 # define context_rdi uc_mcontext.__gregs[_REG_RDI]
251 # define context_r8 uc_mcontext.__gregs[_REG_R8]
252 # define context_r9 uc_mcontext.__gregs[_REG_R9]
253 # define context_r10 uc_mcontext.__gregs[_REG_R10]
254 # define context_r11 uc_mcontext.__gregs[_REG_R11]
255 # define context_r12 uc_mcontext.__gregs[_REG_R12]
256 # define context_r13 uc_mcontext.__gregs[_REG_R13]
257 # define context_r14 uc_mcontext.__gregs[_REG_R14]
258 # define context_r15 uc_mcontext.__gregs[_REG_R15]
259 # define context_flags uc_mcontext.__gregs[_REG_RFL]
260 # define context_err uc_mcontext.__gregs[_REG_ERR]
261 # else
262 # define context_pc uc_mcontext.__gregs[_REG_EIP]
263 # define context_sp uc_mcontext.__gregs[_REG_UESP]
264 # define context_fp uc_mcontext.__gregs[_REG_EBP]
265 # define context_eip uc_mcontext.__gregs[_REG_EIP]
266 # define context_esp uc_mcontext.__gregs[_REG_UESP]
267 # define context_eax uc_mcontext.__gregs[_REG_EAX]
268 # define context_ebx uc_mcontext.__gregs[_REG_EBX]
269 # define context_ecx uc_mcontext.__gregs[_REG_ECX]
270 # define context_edx uc_mcontext.__gregs[_REG_EDX]
271 # define context_ebp uc_mcontext.__gregs[_REG_EBP]
272 # define context_esi uc_mcontext.__gregs[_REG_ESI]
273 # define context_edi uc_mcontext.__gregs[_REG_EDI]
274 # define context_eflags uc_mcontext.__gregs[_REG_EFL]
275 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO]
276 # endif
277 #endif
278
279 address os::current_stack_pointer() {
280 #if defined(__clang__) || defined(__llvm__)
281 register void *esp;
282 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp));
283 return (address) esp;
284 #elif defined(SPARC_WORKS)
285 register void *esp;
286 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp));
287 return (address) ((char*)esp + sizeof(long)*2);
288 #else
289 register void *esp __asm__ (SPELL_REG_SP);
290 return (address) esp;
291 #endif
292 }
293
294 char* os::non_memory_address_word() {
295 // Must never look like an address returned by reserve_memory,
296 // even in its subfields (as defined by the CPU immediate fields,
297 // if the CPU splits constants across multiple instructions).
298
299 return (char*) -1;
300 }
301
302 void os::initialize_thread(Thread* thr) {
303 // Nothing to do.
304 }
305
306 address os::Bsd::ucontext_get_pc(const ucontext_t * uc) {
307 return (address)uc->context_pc;
308 }
309
310 void os::Bsd::ucontext_set_pc(ucontext_t * uc, address pc) {
311 uc->context_pc = (intptr_t)pc ;
312 }
313
314 intptr_t* os::Bsd::ucontext_get_sp(const ucontext_t * uc) {
315 return (intptr_t*)uc->context_sp;
316 }
317
318 intptr_t* os::Bsd::ucontext_get_fp(const ucontext_t * uc) {
319 return (intptr_t*)uc->context_fp;
320 }
321
322 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
323 // is currently interrupted by SIGPROF.
324 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
325 // frames. Currently we don't do that on Bsd, so it's the same as
326 // os::fetch_frame_from_context().
327 // This method is also used for stack overflow signal handling.
328 ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread,
329 const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
330
331 assert(thread != NULL, "just checking");
332 assert(ret_sp != NULL, "just checking");
333 assert(ret_fp != NULL, "just checking");
334
335 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
336 }
337
338 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
339 intptr_t** ret_sp, intptr_t** ret_fp) {
340
341 ExtendedPC epc;
342 const ucontext_t* uc = (const ucontext_t*)ucVoid;
343
344 if (uc != NULL) {
345 epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc));
346 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc);
347 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc);
348 } else {
349 // construct empty ExtendedPC for return value checking
350 epc = ExtendedPC(NULL);
351 if (ret_sp) *ret_sp = (intptr_t *)NULL;
352 if (ret_fp) *ret_fp = (intptr_t *)NULL;
353 }
354
355 return epc;
356 }
357
358 frame os::fetch_frame_from_context(const void* ucVoid) {
359 intptr_t* sp;
360 intptr_t* fp;
361 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
362 return frame(sp, fp, epc.pc());
363 }
364
365 frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) {
366 intptr_t* sp;
367 intptr_t* fp;
368 ExtendedPC epc = os::Bsd::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp);
369 return frame(sp, fp, epc.pc());
370 }
371
372 bool os::Bsd::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
373 address pc = (address) os::Bsd::ucontext_get_pc(uc);
374 if (Interpreter::contains(pc)) {
375 // interpreter performs stack banging after the fixed frame header has
376 // been generated while the compilers perform it before. To maintain
377 // semantic consistency between interpreted and compiled frames, the
378 // method returns the Java sender of the current frame.
379 *fr = os::fetch_frame_from_ucontext(thread, uc);
380 if (!fr->is_first_java_frame()) {
381 assert(fr->safe_for_sender(thread), "Safety check");
382 *fr = fr->java_sender();
383 }
384 } else {
385 // more complex code with compiled code
386 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
387 CodeBlob* cb = CodeCache::find_blob(pc);
388 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
389 // Not sure where the pc points to, fallback to default
390 // stack overflow handling
391 return false;
392 } else {
393 *fr = os::fetch_frame_from_ucontext(thread, uc);
394 // in compiled code, the stack banging is performed just after the return pc
395 // has been pushed on the stack
396 *fr = frame(fr->sp() + 1, fr->fp(), (address)*(fr->sp()));
397 if (!fr->is_java_frame()) {
398 assert(fr->safe_for_sender(thread), "Safety check");
399 *fr = fr->java_sender();
400 }
401 }
402 }
403 assert(fr->is_java_frame(), "Safety check");
404 return true;
405 }
406
407 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get
408 // turned off by -fomit-frame-pointer,
409 frame os::get_sender_for_C_frame(frame* fr) {
410 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
411 }
412
413 intptr_t* _get_previous_fp() {
414 #if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__)
415 register intptr_t **ebp;
416 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp));
417 #else
418 register intptr_t **ebp __asm__ (SPELL_REG_FP);
419 #endif
420 return (intptr_t*) *ebp; // we want what it points to.
421 }
422
423
424 frame os::current_frame() {
425 intptr_t* fp = _get_previous_fp();
426 frame myframe((intptr_t*)os::current_stack_pointer(),
427 (intptr_t*)fp,
428 CAST_FROM_FN_PTR(address, os::current_frame));
429 if (os::is_first_C_frame(&myframe)) {
430 // stack is not walkable
431 return frame();
432 } else {
433 return os::get_sender_for_C_frame(&myframe);
434 }
435 }
436
437 // Utility functions
438
439 // From IA32 System Programming Guide
440 enum {
441 trap_page_fault = 0xE
442 };
443
444 extern "C" JNIEXPORT int
445 JVM_handle_bsd_signal(int sig,
446 siginfo_t* info,
447 void* ucVoid,
448 int abort_if_unrecognized) {
449 ucontext_t* uc = (ucontext_t*) ucVoid;
450
451 Thread* t = Thread::current_or_null_safe();
452
453 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
454 // (no destructors can be run)
455 os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
456
457 SignalHandlerMark shm(t);
458
459 // Note: it's not uncommon that JNI code uses signal/sigset to install
460 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
461 // or have a SIGILL handler when detecting CPU type). When that happens,
462 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To
463 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
464 // that do not require siginfo/ucontext first.
465
466 if (sig == SIGPIPE || sig == SIGXFSZ) {
467 // allow chained handler to go first
468 if (os::Bsd::chained_handler(sig, info, ucVoid)) {
469 return true;
470 } else {
471 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
472 return true;
473 }
474 }
475
476 JavaThread* thread = NULL;
477 VMThread* vmthread = NULL;
478 if (os::Bsd::signal_handlers_are_installed) {
479 if (t != NULL ){
480 if(t->is_Java_thread()) {
481 thread = (JavaThread*)t;
482 }
483 else if(t->is_VM_thread()){
484 vmthread = (VMThread *)t;
485 }
486 }
487 }
488 /*
489 NOTE: does not seem to work on bsd.
490 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
491 // can't decode this kind of signal
492 info = NULL;
493 } else {
494 assert(sig == info->si_signo, "bad siginfo");
495 }
496 */
497 // decide if this trap can be handled by a stub
498 address stub = NULL;
499
500 address pc = NULL;
501
502 //%note os_trap_1
503 if (info != NULL && uc != NULL && thread != NULL) {
504 pc = (address) os::Bsd::ucontext_get_pc(uc);
505
506 if (StubRoutines::is_safefetch_fault(pc)) {
507 os::Bsd::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
508 return 1;
509 }
510
511 // Handle ALL stack overflow variations here
512 if (sig == SIGSEGV || sig == SIGBUS) {
513 address addr = (address) info->si_addr;
514
515 // check if fault address is within thread stack
516 if (thread->on_local_stack(addr)) {
517 // stack overflow
518 if (thread->in_stack_yellow_reserved_zone(addr)) {
519 if (thread->thread_state() == _thread_in_Java) {
520 if (thread->in_stack_reserved_zone(addr)) {
521 frame fr;
522 if (os::Bsd::get_frame_at_stack_banging_point(thread, uc, &fr)) {
523 assert(fr.is_java_frame(), "Must be a Java frame");
524 frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
525 if (activation.sp() != NULL) {
526 thread->disable_stack_reserved_zone();
527 if (activation.is_interpreted_frame()) {
528 thread->set_reserved_stack_activation((address)(
529 activation.fp() + frame::interpreter_frame_initial_sp_offset));
530 } else {
531 thread->set_reserved_stack_activation((address)activation.unextended_sp());
532 }
533 return 1;
534 }
535 }
536 }
537 // Throw a stack overflow exception. Guard pages will be reenabled
538 // while unwinding the stack.
539 thread->disable_stack_yellow_reserved_zone();
540 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
541 } else {
542 // Thread was in the vm or native code. Return and try to finish.
543 thread->disable_stack_yellow_reserved_zone();
544 return 1;
545 }
546 } else if (thread->in_stack_red_zone(addr)) {
547 // Fatal red zone violation. Disable the guard pages and fall through
548 // to handle_unexpected_exception way down below.
549 thread->disable_stack_red_zone();
550 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
551 }
552 }
553 }
554
555 if ((sig == SIGSEGV || sig == SIGBUS) && VM_Version::is_cpuinfo_segv_addr(pc)) {
556 // Verify that OS save/restore AVX registers.
557 stub = VM_Version::cpuinfo_cont_addr();
558 }
559
560 // We test if stub is already set (by the stack overflow code
561 // above) so it is not overwritten by the code that follows. This
562 // check is not required on other platforms, because on other
563 // platforms we check for SIGSEGV only or SIGBUS only, where here
564 // we have to check for both SIGSEGV and SIGBUS.
565 if (thread->thread_state() == _thread_in_Java && stub == NULL) {
566 // Java thread running in Java code => find exception handler if any
567 // a fault inside compiled code, the interpreter, or a stub
568
569 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) {
570 stub = SharedRuntime::get_poll_stub(pc);
571 #if defined(__APPLE__)
572 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions.
573 // 64-bit Darwin may also use a SIGBUS (seen with compressed oops).
574 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from
575 // being called, so only do so if the implicit NULL check is not necessary.
576 } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
577 #else
578 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
579 #endif
580 // BugId 4454115: A read from a MappedByteBuffer can fault
581 // here if the underlying file has been truncated.
582 // Do not crash the VM in such a case.
583 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
584 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
585 if (nm != NULL && nm->has_unsafe_access()) {
586 address next_pc = Assembler::locate_next_instruction(pc);
587 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
588 }
589 }
590 else
591
592 #ifdef AMD64
593 if (sig == SIGFPE &&
594 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
595 stub =
596 SharedRuntime::
597 continuation_for_implicit_exception(thread,
598 pc,
599 SharedRuntime::
600 IMPLICIT_DIVIDE_BY_ZERO);
601 #ifdef __APPLE__
602 } else if (sig == SIGFPE && info->si_code == FPE_NOOP) {
603 int op = pc[0];
604
605 // Skip REX
606 if ((pc[0] & 0xf0) == 0x40) {
607 op = pc[1];
608 } else {
609 op = pc[0];
610 }
611
612 // Check for IDIV
613 if (op == 0xF7) {
614 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO);
615 } else {
616 // TODO: handle more cases if we are using other x86 instructions
617 // that can generate SIGFPE signal.
618 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
619 fatal("please update this code.");
620 }
621 #endif /* __APPLE__ */
622
623 #else
624 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) {
625 // HACK: si_code does not work on bsd 2.2.12-20!!!
626 int op = pc[0];
627 if (op == 0xDB) {
628 // FIST
629 // TODO: The encoding of D2I in i486.ad can cause an exception
630 // prior to the fist instruction if there was an invalid operation
631 // pending. We want to dismiss that exception. From the win_32
632 // side it also seems that if it really was the fist causing
633 // the exception that we do the d2i by hand with different
634 // rounding. Seems kind of weird.
635 // NOTE: that we take the exception at the NEXT floating point instruction.
636 assert(pc[0] == 0xDB, "not a FIST opcode");
637 assert(pc[1] == 0x14, "not a FIST opcode");
638 assert(pc[2] == 0x24, "not a FIST opcode");
639 return true;
640 } else if (op == 0xF7) {
641 // IDIV
642 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
643 } else {
644 // TODO: handle more cases if we are using other x86 instructions
645 // that can generate SIGFPE signal on bsd.
646 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
647 fatal("please update this code.");
648 }
649 #endif // AMD64
650 } else if ((sig == SIGSEGV || sig == SIGBUS) &&
651 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
652 // Determination of interpreter/vtable stub/compiled code null exception
653 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
654 }
655 } else if (thread->thread_state() == _thread_in_vm &&
656 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
657 thread->doing_unsafe_access()) {
658 address next_pc = Assembler::locate_next_instruction(pc);
659 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
660 }
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 address addr = JNI_FastGetField::find_slowcase_pc(pc);
666 if (addr != (address)-1) {
667 stub = addr;
668 }
669 }
670
671 // Check to see if we caught the safepoint code in the
672 // process of write protecting the memory serialization page.
673 // It write enables the page immediately after protecting it
674 // so we can just return to retry the write.
675 if ((sig == SIGSEGV || sig == SIGBUS) &&
676 os::is_memory_serialize_page(thread, (address) info->si_addr)) {
677 // Block current thread until the memory serialize page permission restored.
678 os::block_on_serialize_page_trap();
679 return true;
680 }
681 }
682
683 #ifndef AMD64
684 // Execution protection violation
685 //
686 // This should be kept as the last step in the triage. We don't
687 // have a dedicated trap number for a no-execute fault, so be
688 // conservative and allow other handlers the first shot.
689 //
690 // Note: We don't test that info->si_code == SEGV_ACCERR here.
691 // this si_code is so generic that it is almost meaningless; and
692 // the si_code for this condition may change in the future.
693 // Furthermore, a false-positive should be harmless.
694 if (UnguardOnExecutionViolation > 0 &&
695 (sig == SIGSEGV || sig == SIGBUS) &&
696 uc->context_trapno == trap_page_fault) {
697 int page_size = os::vm_page_size();
698 address addr = (address) info->si_addr;
699 address pc = os::Bsd::ucontext_get_pc(uc);
700 // Make sure the pc and the faulting address are sane.
701 //
702 // If an instruction spans a page boundary, and the page containing
703 // the beginning of the instruction is executable but the following
704 // page is not, the pc and the faulting address might be slightly
705 // different - we still want to unguard the 2nd page in this case.
706 //
707 // 15 bytes seems to be a (very) safe value for max instruction size.
708 bool pc_is_near_addr =
709 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
710 bool instr_spans_page_boundary =
711 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
712 (intptr_t) page_size) > 0);
713
714 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
715 static volatile address last_addr =
716 (address) os::non_memory_address_word();
717
718 // In conservative mode, don't unguard unless the address is in the VM
719 if (addr != last_addr &&
720 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
721
722 // Set memory to RWX and retry
723 address page_start =
724 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
725 bool res = os::protect_memory((char*) page_start, page_size,
726 os::MEM_PROT_RWX);
727
728 log_debug(os)("Execution protection violation "
729 "at " INTPTR_FORMAT
730 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", p2i(addr),
731 p2i(page_start), (res ? "success" : "failed"), errno);
732 stub = pc;
733
734 // Set last_addr so if we fault again at the same address, we don't end
735 // up in an endless loop.
736 //
737 // There are two potential complications here. Two threads trapping at
738 // the same address at the same time could cause one of the threads to
739 // think it already unguarded, and abort the VM. Likely very rare.
740 //
741 // The other race involves two threads alternately trapping at
742 // different addresses and failing to unguard the page, resulting in
743 // an endless loop. This condition is probably even more unlikely than
744 // the first.
745 //
746 // Although both cases could be avoided by using locks or thread local
747 // last_addr, these solutions are unnecessary complication: this
748 // handler is a best-effort safety net, not a complete solution. It is
749 // disabled by default and should only be used as a workaround in case
750 // we missed any no-execute-unsafe VM code.
751
752 last_addr = addr;
753 }
754 }
755 }
756 #endif // !AMD64
757
758 if (stub != NULL) {
759 // save all thread context in case we need to restore it
760 if (thread != NULL) thread->set_saved_exception_pc(pc);
761
762 os::Bsd::ucontext_set_pc(uc, stub);
763 return true;
764 }
765
766 // signal-chaining
767 if (os::Bsd::chained_handler(sig, info, ucVoid)) {
768 return true;
769 }
770
771 if (!abort_if_unrecognized) {
772 // caller wants another chance, so give it to him
773 return false;
774 }
775
776 if (pc == NULL && uc != NULL) {
777 pc = os::Bsd::ucontext_get_pc(uc);
778 }
779
780 // unmask current signal
781 sigset_t newset;
782 sigemptyset(&newset);
783 sigaddset(&newset, sig);
784 sigprocmask(SIG_UNBLOCK, &newset, NULL);
785
786 VMError::report_and_die(t, sig, pc, info, ucVoid);
787
788 ShouldNotReachHere();
789 return false;
790 }
791
792 // From solaris_i486.s ported to bsd_i486.s
793 extern "C" void fixcw();
794
795 void os::Bsd::init_thread_fpu_state(void) {
796 #ifndef AMD64
797 // Set fpu to 53 bit precision. This happens too early to use a stub.
798 fixcw();
799 #endif // !AMD64
800 }
801
802
803 // Check that the bsd kernel version is 2.4 or higher since earlier
804 // versions do not support SSE without patches.
805 bool os::supports_sse() {
806 return true;
807 }
808
809 bool os::is_allocatable(size_t bytes) {
810 #ifdef AMD64
811 // unused on amd64?
812 return true;
813 #else
814
815 if (bytes < 2 * G) {
816 return true;
817 }
818
819 char* addr = reserve_memory(bytes, NULL);
820
821 if (addr != NULL) {
822 release_memory(addr, bytes);
823 }
824
825 return addr != NULL;
826 #endif // AMD64
827 }
828
829 ////////////////////////////////////////////////////////////////////////////////
830 // thread stack
831
832 #ifdef AMD64
833 size_t os::Bsd::min_stack_allowed = 64 * K;
834 #else
835 size_t os::Bsd::min_stack_allowed = (48 DEBUG_ONLY(+4))*K;
836
837 #ifdef __GNUC__
838 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;})
839 #endif
840
841 #endif // AMD64
842
843 // return default stack size for thr_type
844 size_t os::Bsd::default_stack_size(os::ThreadType thr_type) {
845 // default stack size (compiler thread needs larger stack)
846 #ifdef AMD64
847 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
848 #else
849 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
850 #endif // AMD64
851 return s;
852 }
853
854 size_t os::Bsd::default_guard_size(os::ThreadType thr_type) {
855 // Creating guard page is very expensive. Java thread has HotSpot
856 // guard page, only enable glibc guard page for non-Java threads.
857 return (thr_type == java_thread ? 0 : page_size());
858 }
859
860 // Java thread:
861 //
862 // Low memory addresses
863 // +------------------------+
864 // | |\ JavaThread created by VM does not have glibc
865 // | glibc guard page | - guard, attached Java thread usually has
866 // | |/ 1 page glibc guard.
867 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
868 // | |\
869 // | HotSpot Guard Pages | - red and yellow pages
870 // | |/
871 // +------------------------+ JavaThread::stack_yellow_zone_base()
872 // | |\
873 // | Normal Stack | -
874 // | |/
875 // P2 +------------------------+ Thread::stack_base()
876 //
877 // Non-Java thread:
878 //
879 // Low memory addresses
880 // +------------------------+
881 // | |\
882 // | glibc guard page | - usually 1 page
883 // | |/
884 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
885 // | |\
886 // | Normal Stack | -
887 // | |/
888 // P2 +------------------------+ Thread::stack_base()
889 //
890 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
891 // pthread_attr_getstack()
892
893 static void current_stack_region(address * bottom, size_t * size) {
894 #ifdef __APPLE__
895 pthread_t self = pthread_self();
896 void *stacktop = pthread_get_stackaddr_np(self);
897 *size = pthread_get_stacksize_np(self);
898 // workaround for OS X 10.9.0 (Mavericks)
899 // pthread_get_stacksize_np returns 128 pages even though the actual size is 2048 pages
900 if (pthread_main_np() == 1) {
901 if ((*size) < (DEFAULT_MAIN_THREAD_STACK_PAGES * (size_t)getpagesize())) {
902 char kern_osrelease[256];
903 size_t kern_osrelease_size = sizeof(kern_osrelease);
904 int ret = sysctlbyname("kern.osrelease", kern_osrelease, &kern_osrelease_size, NULL, 0);
905 if (ret == 0) {
906 // get the major number, atoi will ignore the minor amd micro portions of the version string
907 if (atoi(kern_osrelease) >= OS_X_10_9_0_KERNEL_MAJOR_VERSION) {
908 *size = (DEFAULT_MAIN_THREAD_STACK_PAGES*getpagesize());
909 }
910 }
911 }
912 }
913 *bottom = (address) stacktop - *size;
914 #elif defined(__OpenBSD__)
915 stack_t ss;
916 int rslt = pthread_stackseg_np(pthread_self(), &ss);
917
918 if (rslt != 0)
919 fatal("pthread_stackseg_np failed with err = %d", rslt);
920
921 *bottom = (address)((char *)ss.ss_sp - ss.ss_size);
922 *size = ss.ss_size;
923 #else
924 pthread_attr_t attr;
925
926 int rslt = pthread_attr_init(&attr);
927
928 // JVM needs to know exact stack location, abort if it fails
929 if (rslt != 0)
930 fatal("pthread_attr_init failed with err = %d", rslt);
931
932 rslt = pthread_attr_get_np(pthread_self(), &attr);
933
934 if (rslt != 0)
935 fatal("pthread_attr_get_np failed with err = %d", rslt);
936
937 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 ||
938 pthread_attr_getstacksize(&attr, size) != 0) {
939 fatal("Can not locate current stack attributes!");
940 }
941
942 pthread_attr_destroy(&attr);
943 #endif
944 assert(os::current_stack_pointer() >= *bottom &&
945 os::current_stack_pointer() < *bottom + *size, "just checking");
946 }
947
948 address os::current_stack_base() {
949 address bottom;
950 size_t size;
951 current_stack_region(&bottom, &size);
952 return (bottom + size);
953 }
954
955 size_t os::current_stack_size() {
956 // stack size includes normal stack and HotSpot guard pages
957 address bottom;
958 size_t size;
959 current_stack_region(&bottom, &size);
960 return size;
961 }
962
963 /////////////////////////////////////////////////////////////////////////////
964 // helper functions for fatal error handler
965
966 void os::print_context(outputStream *st, const void *context) {
967 if (context == NULL) return;
968
969 const ucontext_t *uc = (const ucontext_t*)context;
970 st->print_cr("Registers:");
971 #ifdef AMD64
972 st->print( "RAX=" INTPTR_FORMAT, uc->context_rax);
973 st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx);
974 st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx);
975 st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx);
976 st->cr();
977 st->print( "RSP=" INTPTR_FORMAT, uc->context_rsp);
978 st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp);
979 st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi);
980 st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi);
981 st->cr();
982 st->print( "R8 =" INTPTR_FORMAT, uc->context_r8);
983 st->print(", R9 =" INTPTR_FORMAT, uc->context_r9);
984 st->print(", R10=" INTPTR_FORMAT, uc->context_r10);
985 st->print(", R11=" INTPTR_FORMAT, uc->context_r11);
986 st->cr();
987 st->print( "R12=" INTPTR_FORMAT, uc->context_r12);
988 st->print(", R13=" INTPTR_FORMAT, uc->context_r13);
989 st->print(", R14=" INTPTR_FORMAT, uc->context_r14);
990 st->print(", R15=" INTPTR_FORMAT, uc->context_r15);
991 st->cr();
992 st->print( "RIP=" INTPTR_FORMAT, uc->context_rip);
993 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags);
994 st->print(", ERR=" INTPTR_FORMAT, uc->context_err);
995 st->cr();
996 st->print(" TRAPNO=" INTPTR_FORMAT, uc->context_trapno);
997 #else
998 st->print( "EAX=" INTPTR_FORMAT, uc->context_eax);
999 st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx);
1000 st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx);
1001 st->print(", EDX=" INTPTR_FORMAT, uc->context_edx);
1002 st->cr();
1003 st->print( "ESP=" INTPTR_FORMAT, uc->context_esp);
1004 st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp);
1005 st->print(", ESI=" INTPTR_FORMAT, uc->context_esi);
1006 st->print(", EDI=" INTPTR_FORMAT, uc->context_edi);
1007 st->cr();
1008 st->print( "EIP=" INTPTR_FORMAT, uc->context_eip);
1009 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags);
1010 #endif // AMD64
1011 st->cr();
1012 st->cr();
1013
1014 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc);
1015 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
1016 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
1017 st->cr();
1018
1019 // Note: it may be unsafe to inspect memory near pc. For example, pc may
1020 // point to garbage if entry point in an nmethod is corrupted. Leave
1021 // this at the end, and hope for the best.
1022 address pc = os::Bsd::ucontext_get_pc(uc);
1023 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
1024 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
1025 }
1026
1027 void os::print_register_info(outputStream *st, const void *context) {
1028 if (context == NULL) return;
1029
1030 const ucontext_t *uc = (const ucontext_t*)context;
1031
1032 st->print_cr("Register to memory mapping:");
1033 st->cr();
1034
1035 // this is horrendously verbose but the layout of the registers in the
1036 // context does not match how we defined our abstract Register set, so
1037 // we can't just iterate through the gregs area
1038
1039 // this is only for the "general purpose" registers
1040
1041 #ifdef AMD64
1042 st->print("RAX="); print_location(st, uc->context_rax);
1043 st->print("RBX="); print_location(st, uc->context_rbx);
1044 st->print("RCX="); print_location(st, uc->context_rcx);
1045 st->print("RDX="); print_location(st, uc->context_rdx);
1046 st->print("RSP="); print_location(st, uc->context_rsp);
1047 st->print("RBP="); print_location(st, uc->context_rbp);
1048 st->print("RSI="); print_location(st, uc->context_rsi);
1049 st->print("RDI="); print_location(st, uc->context_rdi);
1050 st->print("R8 ="); print_location(st, uc->context_r8);
1051 st->print("R9 ="); print_location(st, uc->context_r9);
1052 st->print("R10="); print_location(st, uc->context_r10);
1053 st->print("R11="); print_location(st, uc->context_r11);
1054 st->print("R12="); print_location(st, uc->context_r12);
1055 st->print("R13="); print_location(st, uc->context_r13);
1056 st->print("R14="); print_location(st, uc->context_r14);
1057 st->print("R15="); print_location(st, uc->context_r15);
1058 #else
1059 st->print("EAX="); print_location(st, uc->context_eax);
1060 st->print("EBX="); print_location(st, uc->context_ebx);
1061 st->print("ECX="); print_location(st, uc->context_ecx);
1062 st->print("EDX="); print_location(st, uc->context_edx);
1063 st->print("ESP="); print_location(st, uc->context_esp);
1064 st->print("EBP="); print_location(st, uc->context_ebp);
1065 st->print("ESI="); print_location(st, uc->context_esi);
1066 st->print("EDI="); print_location(st, uc->context_edi);
1067 #endif // AMD64
1068
1069 st->cr();
1070 }
1071
1072 void os::setup_fpu() {
1073 #ifndef AMD64
1074 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
1075 __asm__ volatile ( "fldcw (%0)" :
1076 : "r" (fpu_cntrl) : "memory");
1077 #endif // !AMD64
1078 }
1079
1080 #ifndef PRODUCT
1081 void os::verify_stack_alignment() {
1082 }
1083 #endif
1084
1085 int os::extra_bang_size_in_bytes() {
1086 // JDK-8050147 requires the full cache line bang for x86.
1087 return VM_Version::L1_line_size();
1088 }