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_bsd.h"
34 #include "memory/allocation.inline.hpp"
35 #include "mutex_bsd.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 #ifdef AMD64
83 #define SPELL_REG_SP "rsp"
84 #define SPELL_REG_FP "rbp"
85 #else
86 #define SPELL_REG_SP "esp"
87 #define SPELL_REG_FP "ebp"
88 #endif // AMD64
89
90 #ifdef __FreeBSD__
91 # define context_trapno uc_mcontext.mc_trapno
92 # ifdef AMD64
93 # define context_pc uc_mcontext.mc_rip
94 # define context_sp uc_mcontext.mc_rsp
95 # define context_fp uc_mcontext.mc_rbp
96 # define context_rip uc_mcontext.mc_rip
97 # define context_rsp uc_mcontext.mc_rsp
98 # define context_rbp uc_mcontext.mc_rbp
99 # define context_rax uc_mcontext.mc_rax
100 # define context_rbx uc_mcontext.mc_rbx
101 # define context_rcx uc_mcontext.mc_rcx
102 # define context_rdx uc_mcontext.mc_rdx
103 # define context_rsi uc_mcontext.mc_rsi
104 # define context_rdi uc_mcontext.mc_rdi
105 # define context_r8 uc_mcontext.mc_r8
106 # define context_r9 uc_mcontext.mc_r9
107 # define context_r10 uc_mcontext.mc_r10
108 # define context_r11 uc_mcontext.mc_r11
109 # define context_r12 uc_mcontext.mc_r12
110 # define context_r13 uc_mcontext.mc_r13
111 # define context_r14 uc_mcontext.mc_r14
112 # define context_r15 uc_mcontext.mc_r15
113 # define context_flags uc_mcontext.mc_flags
114 # define context_err uc_mcontext.mc_err
115 # else
116 # define context_pc uc_mcontext.mc_eip
117 # define context_sp uc_mcontext.mc_esp
118 # define context_fp uc_mcontext.mc_ebp
119 # define context_eip uc_mcontext.mc_eip
120 # define context_esp uc_mcontext.mc_esp
121 # define context_eax uc_mcontext.mc_eax
122 # define context_ebx uc_mcontext.mc_ebx
123 # define context_ecx uc_mcontext.mc_ecx
124 # define context_edx uc_mcontext.mc_edx
125 # define context_ebp uc_mcontext.mc_ebp
126 # define context_esi uc_mcontext.mc_esi
127 # define context_edi uc_mcontext.mc_edi
128 # define context_eflags uc_mcontext.mc_eflags
129 # define context_trapno uc_mcontext.mc_trapno
130 # endif
131 #endif
132
133 #ifdef __APPLE__
134 # if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
135 // 10.5 UNIX03 member name prefixes
136 #define DU3_PREFIX(s, m) __ ## s.__ ## m
137 # else
138 #define DU3_PREFIX(s, m) s ## . ## m
139 # endif
140
141 # ifdef AMD64
142 # define context_pc context_rip
143 # define context_sp context_rsp
144 # define context_fp context_rbp
145 # define context_rip uc_mcontext->DU3_PREFIX(ss,rip)
146 # define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp)
147 # define context_rax uc_mcontext->DU3_PREFIX(ss,rax)
148 # define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx)
149 # define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx)
150 # define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx)
151 # define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp)
152 # define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi)
153 # define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi)
154 # define context_r8 uc_mcontext->DU3_PREFIX(ss,r8)
155 # define context_r9 uc_mcontext->DU3_PREFIX(ss,r9)
156 # define context_r10 uc_mcontext->DU3_PREFIX(ss,r10)
157 # define context_r11 uc_mcontext->DU3_PREFIX(ss,r11)
158 # define context_r12 uc_mcontext->DU3_PREFIX(ss,r12)
159 # define context_r13 uc_mcontext->DU3_PREFIX(ss,r13)
160 # define context_r14 uc_mcontext->DU3_PREFIX(ss,r14)
161 # define context_r15 uc_mcontext->DU3_PREFIX(ss,r15)
162 # define context_flags uc_mcontext->DU3_PREFIX(ss,rflags)
163 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno)
164 # define context_err uc_mcontext->DU3_PREFIX(es,err)
165 # else
166 # define context_pc context_eip
167 # define context_sp context_esp
168 # define context_fp context_ebp
169 # define context_eip uc_mcontext->DU3_PREFIX(ss,eip)
170 # define context_esp uc_mcontext->DU3_PREFIX(ss,esp)
171 # define context_eax uc_mcontext->DU3_PREFIX(ss,eax)
172 # define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx)
173 # define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx)
174 # define context_edx uc_mcontext->DU3_PREFIX(ss,edx)
175 # define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp)
176 # define context_esi uc_mcontext->DU3_PREFIX(ss,esi)
177 # define context_edi uc_mcontext->DU3_PREFIX(ss,edi)
178 # define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags)
179 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno)
180 # endif
181 #endif
182
183 #ifdef __OpenBSD__
184 # define context_trapno sc_trapno
185 # ifdef AMD64
186 # define context_pc sc_rip
187 # define context_sp sc_rsp
188 # define context_fp sc_rbp
189 # define context_rip sc_rip
190 # define context_rsp sc_rsp
191 # define context_rbp sc_rbp
192 # define context_rax sc_rax
193 # define context_rbx sc_rbx
194 # define context_rcx sc_rcx
195 # define context_rdx sc_rdx
196 # define context_rsi sc_rsi
197 # define context_rdi sc_rdi
198 # define context_r8 sc_r8
199 # define context_r9 sc_r9
200 # define context_r10 sc_r10
201 # define context_r11 sc_r11
202 # define context_r12 sc_r12
203 # define context_r13 sc_r13
204 # define context_r14 sc_r14
205 # define context_r15 sc_r15
206 # define context_flags sc_rflags
207 # define context_err sc_err
208 # else
209 # define context_pc sc_eip
210 # define context_sp sc_esp
211 # define context_fp sc_ebp
212 # define context_eip sc_eip
213 # define context_esp sc_esp
214 # define context_eax sc_eax
215 # define context_ebx sc_ebx
216 # define context_ecx sc_ecx
217 # define context_edx sc_edx
218 # define context_ebp sc_ebp
219 # define context_esi sc_esi
220 # define context_edi sc_edi
221 # define context_eflags sc_eflags
222 # define context_trapno sc_trapno
223 # endif
224 #endif
225
226 #ifdef __NetBSD__
227 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO]
228 # ifdef AMD64
229 # define __register_t __greg_t
230 # define context_pc uc_mcontext.__gregs[_REG_RIP]
231 # define context_sp uc_mcontext.__gregs[_REG_URSP]
232 # define context_fp uc_mcontext.__gregs[_REG_RBP]
233 # define context_rip uc_mcontext.__gregs[_REG_RIP]
234 # define context_rsp uc_mcontext.__gregs[_REG_URSP]
235 # define context_rax uc_mcontext.__gregs[_REG_RAX]
236 # define context_rbx uc_mcontext.__gregs[_REG_RBX]
237 # define context_rcx uc_mcontext.__gregs[_REG_RCX]
238 # define context_rdx uc_mcontext.__gregs[_REG_RDX]
239 # define context_rbp uc_mcontext.__gregs[_REG_RBP]
240 # define context_rsi uc_mcontext.__gregs[_REG_RSI]
241 # define context_rdi uc_mcontext.__gregs[_REG_RDI]
242 # define context_r8 uc_mcontext.__gregs[_REG_R8]
243 # define context_r9 uc_mcontext.__gregs[_REG_R9]
244 # define context_r10 uc_mcontext.__gregs[_REG_R10]
245 # define context_r11 uc_mcontext.__gregs[_REG_R11]
246 # define context_r12 uc_mcontext.__gregs[_REG_R12]
247 # define context_r13 uc_mcontext.__gregs[_REG_R13]
248 # define context_r14 uc_mcontext.__gregs[_REG_R14]
249 # define context_r15 uc_mcontext.__gregs[_REG_R15]
250 # define context_flags uc_mcontext.__gregs[_REG_RFL]
251 # define context_err uc_mcontext.__gregs[_REG_ERR]
252 # else
253 # define context_pc uc_mcontext.__gregs[_REG_EIP]
254 # define context_sp uc_mcontext.__gregs[_REG_UESP]
255 # define context_fp uc_mcontext.__gregs[_REG_EBP]
256 # define context_eip uc_mcontext.__gregs[_REG_EIP]
257 # define context_esp uc_mcontext.__gregs[_REG_UESP]
258 # define context_eax uc_mcontext.__gregs[_REG_EAX]
259 # define context_ebx uc_mcontext.__gregs[_REG_EBX]
260 # define context_ecx uc_mcontext.__gregs[_REG_ECX]
261 # define context_edx uc_mcontext.__gregs[_REG_EDX]
262 # define context_ebp uc_mcontext.__gregs[_REG_EBP]
263 # define context_esi uc_mcontext.__gregs[_REG_ESI]
264 # define context_edi uc_mcontext.__gregs[_REG_EDI]
265 # define context_eflags uc_mcontext.__gregs[_REG_EFL]
266 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO]
267 # endif
268 #endif
269
270 address os::current_stack_pointer() {
271 #if defined(__clang__) || defined(__llvm__)
272 register void *esp;
273 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp));
274 return (address) esp;
275 #elif defined(SPARC_WORKS)
276 register void *esp;
277 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp));
278 return (address) ((char*)esp + sizeof(long)*2);
279 #else
280 register void *esp __asm__ (SPELL_REG_SP);
281 return (address) esp;
282 #endif
283 }
284
285 char* os::non_memory_address_word() {
286 // Must never look like an address returned by reserve_memory,
287 // even in its subfields (as defined by the CPU immediate fields,
288 // if the CPU splits constants across multiple instructions).
289
290 return (char*) -1;
291 }
292
293 void os::initialize_thread(Thread* thr) {
294 // Nothing to do.
295 }
296
297 address os::Bsd::ucontext_get_pc(ucontext_t * uc) {
298 return (address)uc->context_pc;
299 }
300
301 intptr_t* os::Bsd::ucontext_get_sp(ucontext_t * uc) {
302 return (intptr_t*)uc->context_sp;
303 }
304
305 intptr_t* os::Bsd::ucontext_get_fp(ucontext_t * uc) {
306 return (intptr_t*)uc->context_fp;
307 }
308
309 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
310 // is currently interrupted by SIGPROF.
311 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
312 // frames. Currently we don't do that on Bsd, so it's the same as
313 // os::fetch_frame_from_context().
314 ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread,
315 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
316
317 assert(thread != NULL, "just checking");
318 assert(ret_sp != NULL, "just checking");
319 assert(ret_fp != NULL, "just checking");
320
321 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
322 }
323
324 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
325 intptr_t** ret_sp, intptr_t** ret_fp) {
326
327 ExtendedPC epc;
328 ucontext_t* uc = (ucontext_t*)ucVoid;
329
330 if (uc != NULL) {
331 epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc));
332 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc);
333 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc);
334 } else {
335 // construct empty ExtendedPC for return value checking
336 epc = ExtendedPC(NULL);
337 if (ret_sp) *ret_sp = (intptr_t *)NULL;
338 if (ret_fp) *ret_fp = (intptr_t *)NULL;
339 }
340
341 return epc;
342 }
343
344 frame os::fetch_frame_from_context(void* ucVoid) {
345 intptr_t* sp;
346 intptr_t* fp;
347 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
348 return frame(sp, fp, epc.pc());
349 }
350
351 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get
352 // turned off by -fomit-frame-pointer,
353 frame os::get_sender_for_C_frame(frame* fr) {
354 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
355 }
356
357 intptr_t* _get_previous_fp() {
358 #if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__)
359 register intptr_t **ebp;
360 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp));
361 #else
362 register intptr_t **ebp __asm__ (SPELL_REG_FP);
363 #endif
364 return (intptr_t*) *ebp; // we want what it points to.
365 }
366
367
368 frame os::current_frame() {
369 intptr_t* fp = _get_previous_fp();
370 frame myframe((intptr_t*)os::current_stack_pointer(),
371 (intptr_t*)fp,
372 CAST_FROM_FN_PTR(address, os::current_frame));
373 if (os::is_first_C_frame(&myframe)) {
374 // stack is not walkable
375 return frame();
376 } else {
377 return os::get_sender_for_C_frame(&myframe);
378 }
379 }
380
381 // Utility functions
382
383 // From IA32 System Programming Guide
384 enum {
385 trap_page_fault = 0xE
386 };
387
388 extern "C" JNIEXPORT int
389 JVM_handle_bsd_signal(int sig,
390 siginfo_t* info,
391 void* ucVoid,
392 int abort_if_unrecognized) {
393 ucontext_t* uc = (ucontext_t*) ucVoid;
394
395 Thread* t = ThreadLocalStorage::get_thread_slow();
396
397 SignalHandlerMark shm(t);
398
399 // Note: it's not uncommon that JNI code uses signal/sigset to install
400 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
401 // or have a SIGILL handler when detecting CPU type). When that happens,
402 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To
403 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
404 // that do not require siginfo/ucontext first.
405
406 if (sig == SIGPIPE || sig == SIGXFSZ) {
407 // allow chained handler to go first
408 if (os::Bsd::chained_handler(sig, info, ucVoid)) {
409 return true;
410 } else {
411 if (PrintMiscellaneous && (WizardMode || Verbose)) {
412 char buf[64];
413 warning("Ignoring %s - see bugs 4229104 or 646499219",
414 os::exception_name(sig, buf, sizeof(buf)));
415 }
416 return true;
417 }
418 }
419
420 JavaThread* thread = NULL;
421 VMThread* vmthread = NULL;
422 if (os::Bsd::signal_handlers_are_installed) {
423 if (t != NULL ){
424 if(t->is_Java_thread()) {
425 thread = (JavaThread*)t;
426 }
427 else if(t->is_VM_thread()){
428 vmthread = (VMThread *)t;
429 }
430 }
431 }
432 /*
433 NOTE: does not seem to work on bsd.
434 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
435 // can't decode this kind of signal
436 info = NULL;
437 } else {
438 assert(sig == info->si_signo, "bad siginfo");
439 }
440 */
441 // decide if this trap can be handled by a stub
442 address stub = NULL;
443
444 address pc = NULL;
445
446 //%note os_trap_1
447 if (info != NULL && uc != NULL && thread != NULL) {
448 pc = (address) os::Bsd::ucontext_get_pc(uc);
449
450 if (StubRoutines::is_safefetch_fault(pc)) {
451 uc->context_pc = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc));
452 return 1;
453 }
454
455 // Handle ALL stack overflow variations here
456 if (sig == SIGSEGV || sig == SIGBUS) {
457 address addr = (address) info->si_addr;
458
459 // check if fault address is within thread stack
460 if (addr < thread->stack_base() &&
461 addr >= thread->stack_base() - thread->stack_size()) {
462 // stack overflow
463 if (thread->in_stack_yellow_zone(addr)) {
464 thread->disable_stack_yellow_zone();
465 if (thread->thread_state() == _thread_in_Java) {
466 // Throw a stack overflow exception. Guard pages will be reenabled
467 // while unwinding the stack.
468 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
469 } else {
470 // Thread was in the vm or native code. Return and try to finish.
471 return 1;
472 }
473 } else if (thread->in_stack_red_zone(addr)) {
474 // Fatal red zone violation. Disable the guard pages and fall through
475 // to handle_unexpected_exception way down below.
476 thread->disable_stack_red_zone();
477 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
478 }
479 }
480 }
481
482 // We test if stub is already set (by the stack overflow code
483 // above) so it is not overwritten by the code that follows. This
484 // check is not required on other platforms, because on other
485 // platforms we check for SIGSEGV only or SIGBUS only, where here
486 // we have to check for both SIGSEGV and SIGBUS.
487 if (thread->thread_state() == _thread_in_Java && stub == NULL) {
488 // Java thread running in Java code => find exception handler if any
489 // a fault inside compiled code, the interpreter, or a stub
490
491 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) {
492 stub = SharedRuntime::get_poll_stub(pc);
493 #if defined(__APPLE__)
494 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions.
495 // 64-bit Darwin may also use a SIGBUS (seen with compressed oops).
496 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from
497 // being called, so only do so if the implicit NULL check is not necessary.
498 } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
499 #else
500 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
501 #endif
502 // BugId 4454115: A read from a MappedByteBuffer can fault
503 // here if the underlying file has been truncated.
504 // Do not crash the VM in such a case.
505 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
506 nmethod* nm = (cb != NULL && cb->is_nmethod()) ? (nmethod*)cb : NULL;
507 if (nm != NULL && nm->has_unsafe_access()) {
508 stub = StubRoutines::handler_for_unsafe_access();
509 }
510 }
511 else
512
513 #ifdef AMD64
514 if (sig == SIGFPE &&
515 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
516 stub =
517 SharedRuntime::
518 continuation_for_implicit_exception(thread,
519 pc,
520 SharedRuntime::
521 IMPLICIT_DIVIDE_BY_ZERO);
522 #ifdef __APPLE__
523 } else if (sig == SIGFPE && info->si_code == FPE_NOOP) {
524 int op = pc[0];
525
526 // Skip REX
527 if ((pc[0] & 0xf0) == 0x40) {
528 op = pc[1];
529 } else {
530 op = pc[0];
531 }
532
533 // Check for IDIV
534 if (op == 0xF7) {
535 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO);
536 } else {
537 // TODO: handle more cases if we are using other x86 instructions
538 // that can generate SIGFPE signal.
539 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
540 fatal("please update this code.");
541 }
542 #endif /* __APPLE__ */
543
544 #else
545 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) {
546 // HACK: si_code does not work on bsd 2.2.12-20!!!
547 int op = pc[0];
548 if (op == 0xDB) {
549 // FIST
550 // TODO: The encoding of D2I in i486.ad can cause an exception
551 // prior to the fist instruction if there was an invalid operation
552 // pending. We want to dismiss that exception. From the win_32
553 // side it also seems that if it really was the fist causing
554 // the exception that we do the d2i by hand with different
555 // rounding. Seems kind of weird.
556 // NOTE: that we take the exception at the NEXT floating point instruction.
557 assert(pc[0] == 0xDB, "not a FIST opcode");
558 assert(pc[1] == 0x14, "not a FIST opcode");
559 assert(pc[2] == 0x24, "not a FIST opcode");
560 return true;
561 } else if (op == 0xF7) {
562 // IDIV
563 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
564 } else {
565 // TODO: handle more cases if we are using other x86 instructions
566 // that can generate SIGFPE signal on bsd.
567 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
568 fatal("please update this code.");
569 }
570 #endif // AMD64
571 } else if ((sig == SIGSEGV || sig == SIGBUS) &&
572 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
573 // Determination of interpreter/vtable stub/compiled code null exception
574 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
575 }
576 } else if (thread->thread_state() == _thread_in_vm &&
577 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
578 thread->doing_unsafe_access()) {
579 stub = StubRoutines::handler_for_unsafe_access();
580 }
581
582 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
583 // and the heap gets shrunk before the field access.
584 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
585 address addr = JNI_FastGetField::find_slowcase_pc(pc);
586 if (addr != (address)-1) {
587 stub = addr;
588 }
589 }
590
591 // Check to see if we caught the safepoint code in the
592 // process of write protecting the memory serialization page.
593 // It write enables the page immediately after protecting it
594 // so we can just return to retry the write.
595 if ((sig == SIGSEGV || sig == SIGBUS) &&
596 os::is_memory_serialize_page(thread, (address) info->si_addr)) {
597 // Block current thread until the memory serialize page permission restored.
598 os::block_on_serialize_page_trap();
599 return true;
600 }
601 }
602
603 #ifndef AMD64
604 // Execution protection violation
605 //
606 // This should be kept as the last step in the triage. We don't
607 // have a dedicated trap number for a no-execute fault, so be
608 // conservative and allow other handlers the first shot.
609 //
610 // Note: We don't test that info->si_code == SEGV_ACCERR here.
611 // this si_code is so generic that it is almost meaningless; and
612 // the si_code for this condition may change in the future.
613 // Furthermore, a false-positive should be harmless.
614 if (UnguardOnExecutionViolation > 0 &&
615 (sig == SIGSEGV || sig == SIGBUS) &&
616 uc->context_trapno == trap_page_fault) {
617 int page_size = os::vm_page_size();
618 address addr = (address) info->si_addr;
619 address pc = os::Bsd::ucontext_get_pc(uc);
620 // Make sure the pc and the faulting address are sane.
621 //
622 // If an instruction spans a page boundary, and the page containing
623 // the beginning of the instruction is executable but the following
624 // page is not, the pc and the faulting address might be slightly
625 // different - we still want to unguard the 2nd page in this case.
626 //
627 // 15 bytes seems to be a (very) safe value for max instruction size.
628 bool pc_is_near_addr =
629 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
630 bool instr_spans_page_boundary =
631 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
632 (intptr_t) page_size) > 0);
633
634 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
635 static volatile address last_addr =
636 (address) os::non_memory_address_word();
637
638 // In conservative mode, don't unguard unless the address is in the VM
639 if (addr != last_addr &&
640 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
641
642 // Set memory to RWX and retry
643 address page_start =
644 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
645 bool res = os::protect_memory((char*) page_start, page_size,
646 os::MEM_PROT_RWX);
647
648 if (PrintMiscellaneous && Verbose) {
649 char buf[256];
650 jio_snprintf(buf, sizeof(buf), "Execution protection violation "
651 "at " INTPTR_FORMAT
652 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
653 page_start, (res ? "success" : "failed"), errno);
654 tty->print_raw_cr(buf);
655 }
656 stub = pc;
657
658 // Set last_addr so if we fault again at the same address, we don't end
659 // up in an endless loop.
660 //
661 // There are two potential complications here. Two threads trapping at
662 // the same address at the same time could cause one of the threads to
663 // think it already unguarded, and abort the VM. Likely very rare.
664 //
665 // The other race involves two threads alternately trapping at
666 // different addresses and failing to unguard the page, resulting in
667 // an endless loop. This condition is probably even more unlikely than
668 // the first.
669 //
670 // Although both cases could be avoided by using locks or thread local
671 // last_addr, these solutions are unnecessary complication: this
672 // handler is a best-effort safety net, not a complete solution. It is
673 // disabled by default and should only be used as a workaround in case
674 // we missed any no-execute-unsafe VM code.
675
676 last_addr = addr;
677 }
678 }
679 }
680 #endif // !AMD64
681
682 if (stub != NULL) {
683 // save all thread context in case we need to restore it
684 if (thread != NULL) thread->set_saved_exception_pc(pc);
685
686 uc->context_pc = (intptr_t)stub;
687 return true;
688 }
689
690 // signal-chaining
691 if (os::Bsd::chained_handler(sig, info, ucVoid)) {
692 return true;
693 }
694
695 if (!abort_if_unrecognized) {
696 // caller wants another chance, so give it to him
697 return false;
698 }
699
700 if (pc == NULL && uc != NULL) {
701 pc = os::Bsd::ucontext_get_pc(uc);
702 }
703
704 // unmask current signal
705 sigset_t newset;
706 sigemptyset(&newset);
707 sigaddset(&newset, sig);
708 sigprocmask(SIG_UNBLOCK, &newset, NULL);
709
710 VMError err(t, sig, pc, info, ucVoid);
711 err.report_and_die();
712
713 ShouldNotReachHere();
714 }
715
716 // From solaris_i486.s ported to bsd_i486.s
717 extern "C" void fixcw();
718
719 void os::Bsd::init_thread_fpu_state(void) {
720 #ifndef AMD64
721 // Set fpu to 53 bit precision. This happens too early to use a stub.
722 fixcw();
723 #endif // !AMD64
724 }
725
726
727 // Check that the bsd kernel version is 2.4 or higher since earlier
728 // versions do not support SSE without patches.
729 bool os::supports_sse() {
730 return true;
731 }
732
733 bool os::is_allocatable(size_t bytes) {
734 #ifdef AMD64
735 // unused on amd64?
736 return true;
737 #else
738
739 if (bytes < 2 * G) {
740 return true;
741 }
742
743 char* addr = reserve_memory(bytes, NULL);
744
745 if (addr != NULL) {
746 release_memory(addr, bytes);
747 }
748
749 return addr != NULL;
750 #endif // AMD64
751 }
752
753 ////////////////////////////////////////////////////////////////////////////////
754 // thread stack
755
756 #ifdef AMD64
757 size_t os::Bsd::min_stack_allowed = 64 * K;
758
759 // amd64: pthread on amd64 is always in floating stack mode
760 bool os::Bsd::supports_variable_stack_size() { return true; }
761 #else
762 size_t os::Bsd::min_stack_allowed = (48 DEBUG_ONLY(+4))*K;
763
764 #ifdef __GNUC__
765 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;})
766 #endif
767
768 bool os::Bsd::supports_variable_stack_size() { return true; }
769 #endif // AMD64
770
771 // return default stack size for thr_type
772 size_t os::Bsd::default_stack_size(os::ThreadType thr_type) {
773 // default stack size (compiler thread needs larger stack)
774 #ifdef AMD64
775 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
776 #else
777 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
778 #endif // AMD64
779 return s;
780 }
781
782 size_t os::Bsd::default_guard_size(os::ThreadType thr_type) {
783 // Creating guard page is very expensive. Java thread has HotSpot
784 // guard page, only enable glibc guard page for non-Java threads.
785 return (thr_type == java_thread ? 0 : page_size());
786 }
787
788 // Java thread:
789 //
790 // Low memory addresses
791 // +------------------------+
792 // | |\ JavaThread created by VM does not have glibc
793 // | glibc guard page | - guard, attached Java thread usually has
794 // | |/ 1 page glibc guard.
795 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
796 // | |\
797 // | HotSpot Guard Pages | - red and yellow pages
798 // | |/
799 // +------------------------+ JavaThread::stack_yellow_zone_base()
800 // | |\
801 // | Normal Stack | -
802 // | |/
803 // P2 +------------------------+ Thread::stack_base()
804 //
805 // Non-Java thread:
806 //
807 // Low memory addresses
808 // +------------------------+
809 // | |\
810 // | glibc guard page | - usually 1 page
811 // | |/
812 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
813 // | |\
814 // | Normal Stack | -
815 // | |/
816 // P2 +------------------------+ Thread::stack_base()
817 //
818 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
819 // pthread_attr_getstack()
820
821 static void current_stack_region(address * bottom, size_t * size) {
822 #ifdef __APPLE__
823 pthread_t self = pthread_self();
824 void *stacktop = pthread_get_stackaddr_np(self);
825 *size = pthread_get_stacksize_np(self);
826 *bottom = (address) stacktop - *size;
827 #elif defined(__OpenBSD__)
828 stack_t ss;
829 int rslt = pthread_stackseg_np(pthread_self(), &ss);
830
831 if (rslt != 0)
832 fatal(err_msg("pthread_stackseg_np failed with err = %d", rslt));
833
834 *bottom = (address)((char *)ss.ss_sp - ss.ss_size);
835 *size = ss.ss_size;
836 #else
837 pthread_attr_t attr;
838
839 int rslt = pthread_attr_init(&attr);
840
841 // JVM needs to know exact stack location, abort if it fails
842 if (rslt != 0)
843 fatal(err_msg("pthread_attr_init failed with err = %d", rslt));
844
845 rslt = pthread_attr_get_np(pthread_self(), &attr);
846
847 if (rslt != 0)
848 fatal(err_msg("pthread_attr_get_np failed with err = %d", rslt));
849
850 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 ||
851 pthread_attr_getstacksize(&attr, size) != 0) {
852 fatal("Can not locate current stack attributes!");
853 }
854
855 pthread_attr_destroy(&attr);
856 #endif
857 assert(os::current_stack_pointer() >= *bottom &&
858 os::current_stack_pointer() < *bottom + *size, "just checking");
859 }
860
861 address os::current_stack_base() {
862 address bottom;
863 size_t size;
864 current_stack_region(&bottom, &size);
865 return (bottom + size);
866 }
867
868 size_t os::current_stack_size() {
869 // stack size includes normal stack and HotSpot guard pages
870 address bottom;
871 size_t size;
872 current_stack_region(&bottom, &size);
873 return size;
874 }
875
876 /////////////////////////////////////////////////////////////////////////////
877 // helper functions for fatal error handler
878
879 void os::print_context(outputStream *st, void *context) {
880 if (context == NULL) return;
881
882 ucontext_t *uc = (ucontext_t*)context;
883 st->print_cr("Registers:");
884 #ifdef AMD64
885 st->print( "RAX=" INTPTR_FORMAT, uc->context_rax);
886 st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx);
887 st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx);
888 st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx);
889 st->cr();
890 st->print( "RSP=" INTPTR_FORMAT, uc->context_rsp);
891 st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp);
892 st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi);
893 st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi);
894 st->cr();
895 st->print( "R8 =" INTPTR_FORMAT, uc->context_r8);
896 st->print(", R9 =" INTPTR_FORMAT, uc->context_r9);
897 st->print(", R10=" INTPTR_FORMAT, uc->context_r10);
898 st->print(", R11=" INTPTR_FORMAT, uc->context_r11);
899 st->cr();
900 st->print( "R12=" INTPTR_FORMAT, uc->context_r12);
901 st->print(", R13=" INTPTR_FORMAT, uc->context_r13);
902 st->print(", R14=" INTPTR_FORMAT, uc->context_r14);
903 st->print(", R15=" INTPTR_FORMAT, uc->context_r15);
904 st->cr();
905 st->print( "RIP=" INTPTR_FORMAT, uc->context_rip);
906 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags);
907 st->print(", ERR=" INTPTR_FORMAT, uc->context_err);
908 st->cr();
909 st->print(" TRAPNO=" INTPTR_FORMAT, uc->context_trapno);
910 #else
911 st->print( "EAX=" INTPTR_FORMAT, uc->context_eax);
912 st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx);
913 st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx);
914 st->print(", EDX=" INTPTR_FORMAT, uc->context_edx);
915 st->cr();
916 st->print( "ESP=" INTPTR_FORMAT, uc->context_esp);
917 st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp);
918 st->print(", ESI=" INTPTR_FORMAT, uc->context_esi);
919 st->print(", EDI=" INTPTR_FORMAT, uc->context_edi);
920 st->cr();
921 st->print( "EIP=" INTPTR_FORMAT, uc->context_eip);
922 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags);
923 #endif // AMD64
924 st->cr();
925 st->cr();
926
927 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc);
928 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
929 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
930 st->cr();
931
932 // Note: it may be unsafe to inspect memory near pc. For example, pc may
933 // point to garbage if entry point in an nmethod is corrupted. Leave
934 // this at the end, and hope for the best.
935 address pc = os::Bsd::ucontext_get_pc(uc);
936 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
937 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
938 }
939
940 void os::print_register_info(outputStream *st, void *context) {
941 if (context == NULL) return;
942
943 ucontext_t *uc = (ucontext_t*)context;
944
945 st->print_cr("Register to memory mapping:");
946 st->cr();
947
948 // this is horrendously verbose but the layout of the registers in the
949 // context does not match how we defined our abstract Register set, so
950 // we can't just iterate through the gregs area
951
952 // this is only for the "general purpose" registers
953
954 #ifdef AMD64
955 st->print("RAX="); print_location(st, uc->context_rax);
956 st->print("RBX="); print_location(st, uc->context_rbx);
957 st->print("RCX="); print_location(st, uc->context_rcx);
958 st->print("RDX="); print_location(st, uc->context_rdx);
959 st->print("RSP="); print_location(st, uc->context_rsp);
960 st->print("RBP="); print_location(st, uc->context_rbp);
961 st->print("RSI="); print_location(st, uc->context_rsi);
962 st->print("RDI="); print_location(st, uc->context_rdi);
963 st->print("R8 ="); print_location(st, uc->context_r8);
964 st->print("R9 ="); print_location(st, uc->context_r9);
965 st->print("R10="); print_location(st, uc->context_r10);
966 st->print("R11="); print_location(st, uc->context_r11);
967 st->print("R12="); print_location(st, uc->context_r12);
968 st->print("R13="); print_location(st, uc->context_r13);
969 st->print("R14="); print_location(st, uc->context_r14);
970 st->print("R15="); print_location(st, uc->context_r15);
971 #else
972 st->print("EAX="); print_location(st, uc->context_eax);
973 st->print("EBX="); print_location(st, uc->context_ebx);
974 st->print("ECX="); print_location(st, uc->context_ecx);
975 st->print("EDX="); print_location(st, uc->context_edx);
976 st->print("ESP="); print_location(st, uc->context_esp);
977 st->print("EBP="); print_location(st, uc->context_ebp);
978 st->print("ESI="); print_location(st, uc->context_esi);
979 st->print("EDI="); print_location(st, uc->context_edi);
980 #endif // AMD64
981
982 st->cr();
983 }
984
985 void os::setup_fpu() {
986 #ifndef AMD64
987 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
988 __asm__ volatile ( "fldcw (%0)" :
989 : "r" (fpu_cntrl) : "memory");
990 #endif // !AMD64
991 }
992
993 #ifndef PRODUCT
994 void os::verify_stack_alignment() {
995 }
996 #endif