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 "assembler_x86.inline.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 "nativeInst_x86.hpp"
37 #include "os_share_bsd.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/timer.hpp"
52 #include "thread_bsd.inline.hpp"
53 #include "utilities/events.hpp"
54 #include "utilities/vmError.hpp"
55 #ifdef COMPILER1
56 #include "c1/c1_Runtime1.hpp"
57 #endif
58 #ifdef COMPILER2
59 #include "opto/runtime.hpp"
60 #endif
61
62 // put OS-includes here
63 # include <sys/types.h>
64 # include <sys/mman.h>
65 # include <pthread.h>
66 # include <signal.h>
67 # include <errno.h>
68 # include <dlfcn.h>
69 # include <stdlib.h>
70 # include <stdio.h>
71 # include <unistd.h>
72 # include <sys/resource.h>
73 # include <pthread.h>
74 # include <sys/stat.h>
75 # include <sys/time.h>
76 # include <sys/utsname.h>
77 # include <sys/socket.h>
78 # include <sys/wait.h>
79 # include <pwd.h>
80 # include <poll.h>
81 #ifndef __OpenBSD__
82 # include <ucontext.h>
83 #endif
84
85 #if defined(_ALLBSD_SOURCE) && !defined(__APPLE__) && !defined(__NetBSD__)
86 # include <pthread_np.h>
87 #endif
88
89 #ifdef AMD64
90 #define SPELL_REG_SP "rsp"
91 #define SPELL_REG_FP "rbp"
92 #else
93 #define SPELL_REG_SP "esp"
94 #define SPELL_REG_FP "ebp"
95 #endif // AMD64
96
97 #ifdef __FreeBSD__
98 # define context_trapno uc_mcontext.mc_trapno
99 # ifdef AMD64
100 # define context_pc uc_mcontext.mc_rip
101 # define context_sp uc_mcontext.mc_rsp
102 # define context_fp uc_mcontext.mc_rbp
103 # define context_rip uc_mcontext.mc_rip
104 # define context_rsp uc_mcontext.mc_rsp
105 # define context_rbp uc_mcontext.mc_rbp
106 # define context_rax uc_mcontext.mc_rax
107 # define context_rbx uc_mcontext.mc_rbx
108 # define context_rcx uc_mcontext.mc_rcx
109 # define context_rdx uc_mcontext.mc_rdx
110 # define context_rsi uc_mcontext.mc_rsi
111 # define context_rdi uc_mcontext.mc_rdi
112 # define context_r8 uc_mcontext.mc_r8
113 # define context_r9 uc_mcontext.mc_r9
114 # define context_r10 uc_mcontext.mc_r10
115 # define context_r11 uc_mcontext.mc_r11
116 # define context_r12 uc_mcontext.mc_r12
117 # define context_r13 uc_mcontext.mc_r13
118 # define context_r14 uc_mcontext.mc_r14
119 # define context_r15 uc_mcontext.mc_r15
120 # define context_flags uc_mcontext.mc_flags
121 # define context_err uc_mcontext.mc_err
122 # else
123 # define context_pc uc_mcontext.mc_eip
124 # define context_sp uc_mcontext.mc_esp
125 # define context_fp uc_mcontext.mc_ebp
126 # define context_eip uc_mcontext.mc_eip
127 # define context_esp uc_mcontext.mc_esp
128 # define context_eax uc_mcontext.mc_eax
129 # define context_ebx uc_mcontext.mc_ebx
130 # define context_ecx uc_mcontext.mc_ecx
131 # define context_edx uc_mcontext.mc_edx
132 # define context_ebp uc_mcontext.mc_ebp
133 # define context_esi uc_mcontext.mc_esi
134 # define context_edi uc_mcontext.mc_edi
135 # define context_eflags uc_mcontext.mc_eflags
136 # define context_trapno uc_mcontext.mc_trapno
137 # endif
138 #endif
139
140 #ifdef __APPLE__
141 # if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
142 // 10.5 UNIX03 member name prefixes
143 #define DU3_PREFIX(s, m) __ ## s.__ ## m
144 # else
145 #define DU3_PREFIX(s, m) s ## . ## m
146 # endif
147
148 # ifdef AMD64
149 # define context_pc context_rip
150 # define context_sp context_rsp
151 # define context_fp context_rbp
152 # define context_rip uc_mcontext->DU3_PREFIX(ss,rip)
153 # define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp)
154 # define context_rax uc_mcontext->DU3_PREFIX(ss,rax)
155 # define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx)
156 # define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx)
157 # define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx)
158 # define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp)
159 # define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi)
160 # define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi)
161 # define context_r8 uc_mcontext->DU3_PREFIX(ss,r8)
162 # define context_r9 uc_mcontext->DU3_PREFIX(ss,r9)
163 # define context_r10 uc_mcontext->DU3_PREFIX(ss,r10)
164 # define context_r11 uc_mcontext->DU3_PREFIX(ss,r11)
165 # define context_r12 uc_mcontext->DU3_PREFIX(ss,r12)
166 # define context_r13 uc_mcontext->DU3_PREFIX(ss,r13)
167 # define context_r14 uc_mcontext->DU3_PREFIX(ss,r14)
168 # define context_r15 uc_mcontext->DU3_PREFIX(ss,r15)
169 # define context_flags uc_mcontext->DU3_PREFIX(ss,rflags)
170 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno)
171 # define context_err uc_mcontext->DU3_PREFIX(es,err)
172 # else
173 # define context_pc context_eip
174 # define context_sp context_esp
175 # define context_fp context_ebp
176 # define context_eip uc_mcontext->DU3_PREFIX(ss,eip)
177 # define context_esp uc_mcontext->DU3_PREFIX(ss,esp)
178 # define context_eax uc_mcontext->DU3_PREFIX(ss,eax)
179 # define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx)
180 # define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx)
181 # define context_edx uc_mcontext->DU3_PREFIX(ss,edx)
182 # define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp)
183 # define context_esi uc_mcontext->DU3_PREFIX(ss,esi)
184 # define context_edi uc_mcontext->DU3_PREFIX(ss,edi)
185 # define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags)
186 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno)
187 # endif
188 #endif
189
190 #ifdef __OpenBSD__
191 # define context_trapno sc_trapno
192 # ifdef AMD64
193 # define context_pc sc_rip
194 # define context_sp sc_rsp
195 # define context_fp sc_rbp
196 # define context_rip sc_rip
197 # define context_rsp sc_rsp
198 # define context_rbp sc_rbp
199 # define context_rax sc_rax
200 # define context_rbx sc_rbx
201 # define context_rcx sc_rcx
202 # define context_rdx sc_rdx
203 # define context_rsi sc_rsi
204 # define context_rdi sc_rdi
205 # define context_r8 sc_r8
206 # define context_r9 sc_r9
207 # define context_r10 sc_r10
208 # define context_r11 sc_r11
209 # define context_r12 sc_r12
210 # define context_r13 sc_r13
211 # define context_r14 sc_r14
212 # define context_r15 sc_r15
213 # define context_flags sc_rflags
214 # define context_err sc_err
215 # else
216 # define context_pc sc_eip
217 # define context_sp sc_esp
218 # define context_fp sc_ebp
219 # define context_eip sc_eip
220 # define context_esp sc_esp
221 # define context_eax sc_eax
222 # define context_ebx sc_ebx
223 # define context_ecx sc_ecx
224 # define context_edx sc_edx
225 # define context_ebp sc_ebp
226 # define context_esi sc_esi
227 # define context_edi sc_edi
228 # define context_eflags sc_eflags
229 # define context_trapno sc_trapno
230 # endif
231 #endif
232
233 #ifdef __NetBSD__
234 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO]
235 # ifdef AMD64
236 # define __register_t __greg_t
237 # define context_pc uc_mcontext.__gregs[_REG_RIP]
238 # define context_sp uc_mcontext.__gregs[_REG_URSP]
239 # define context_fp uc_mcontext.__gregs[_REG_RBP]
240 # define context_rip uc_mcontext.__gregs[_REG_RIP]
241 # define context_rsp uc_mcontext.__gregs[_REG_URSP]
242 # define context_rax uc_mcontext.__gregs[_REG_RAX]
243 # define context_rbx uc_mcontext.__gregs[_REG_RBX]
244 # define context_rcx uc_mcontext.__gregs[_REG_RCX]
245 # define context_rdx uc_mcontext.__gregs[_REG_RDX]
246 # define context_rbp uc_mcontext.__gregs[_REG_RBP]
247 # define context_rsi uc_mcontext.__gregs[_REG_RSI]
248 # define context_rdi uc_mcontext.__gregs[_REG_RDI]
249 # define context_r8 uc_mcontext.__gregs[_REG_R8]
250 # define context_r9 uc_mcontext.__gregs[_REG_R9]
251 # define context_r10 uc_mcontext.__gregs[_REG_R10]
252 # define context_r11 uc_mcontext.__gregs[_REG_R11]
253 # define context_r12 uc_mcontext.__gregs[_REG_R12]
254 # define context_r13 uc_mcontext.__gregs[_REG_R13]
255 # define context_r14 uc_mcontext.__gregs[_REG_R14]
256 # define context_r15 uc_mcontext.__gregs[_REG_R15]
257 # define context_flags uc_mcontext.__gregs[_REG_RFL]
258 # define context_err uc_mcontext.__gregs[_REG_ERR]
259 # else
260 # define context_pc uc_mcontext.__gregs[_REG_EIP]
261 # define context_sp uc_mcontext.__gregs[_REG_UESP]
262 # define context_fp uc_mcontext.__gregs[_REG_EBP]
263 # define context_eip uc_mcontext.__gregs[_REG_EIP]
264 # define context_esp uc_mcontext.__gregs[_REG_UESP]
265 # define context_eax uc_mcontext.__gregs[_REG_EAX]
266 # define context_ebx uc_mcontext.__gregs[_REG_EBX]
267 # define context_ecx uc_mcontext.__gregs[_REG_ECX]
268 # define context_edx uc_mcontext.__gregs[_REG_EDX]
269 # define context_ebp uc_mcontext.__gregs[_REG_EBP]
270 # define context_esi uc_mcontext.__gregs[_REG_ESI]
271 # define context_edi uc_mcontext.__gregs[_REG_EDI]
272 # define context_eflags uc_mcontext.__gregs[_REG_EFL]
273 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO]
274 # endif
275 #endif
276
277 address os::current_stack_pointer() {
278 #if defined(__clang__) || defined(__llvm__)
279 register void *esp;
280 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp));
281 return (address) esp;
282 #elif defined(SPARC_WORKS)
283 register void *esp;
284 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp));
285 return (address) ((char*)esp + sizeof(long)*2);
286 #else
287 register void *esp __asm__ (SPELL_REG_SP);
288 return (address) esp;
289 #endif
290 }
291
292 char* os::non_memory_address_word() {
293 // Must never look like an address returned by reserve_memory,
294 // even in its subfields (as defined by the CPU immediate fields,
295 // if the CPU splits constants across multiple instructions).
296
297 return (char*) -1;
298 }
299
300 void os::initialize_thread(Thread* thr) {
301 // Nothing to do.
302 }
303
304 address os::Bsd::ucontext_get_pc(ucontext_t * uc) {
305 return (address)uc->context_pc;
306 }
307
308 intptr_t* os::Bsd::ucontext_get_sp(ucontext_t * uc) {
309 return (intptr_t*)uc->context_sp;
310 }
311
312 intptr_t* os::Bsd::ucontext_get_fp(ucontext_t * uc) {
313 return (intptr_t*)uc->context_fp;
314 }
315
316 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
317 // is currently interrupted by SIGPROF.
318 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
319 // frames. Currently we don't do that on Bsd, so it's the same as
320 // os::fetch_frame_from_context().
321 ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread,
322 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
323
324 assert(thread != NULL, "just checking");
325 assert(ret_sp != NULL, "just checking");
326 assert(ret_fp != NULL, "just checking");
327
328 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
329 }
330
331 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
332 intptr_t** ret_sp, intptr_t** ret_fp) {
333
334 ExtendedPC epc;
335 ucontext_t* uc = (ucontext_t*)ucVoid;
336
337 if (uc != NULL) {
338 epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc));
339 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc);
340 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc);
341 } else {
342 // construct empty ExtendedPC for return value checking
343 epc = ExtendedPC(NULL);
344 if (ret_sp) *ret_sp = (intptr_t *)NULL;
345 if (ret_fp) *ret_fp = (intptr_t *)NULL;
346 }
347
348 return epc;
349 }
350
351 frame os::fetch_frame_from_context(void* ucVoid) {
352 intptr_t* sp;
353 intptr_t* fp;
354 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
355 return frame(sp, fp, epc.pc());
356 }
357
358 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get
359 // turned off by -fomit-frame-pointer,
360 frame os::get_sender_for_C_frame(frame* fr) {
361 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
362 }
363
364 intptr_t* _get_previous_fp() {
365 #if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__)
366 register intptr_t **ebp;
367 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp));
368 #else
369 register intptr_t **ebp __asm__ (SPELL_REG_FP);
370 #endif
371 return (intptr_t*) *ebp; // we want what it points to.
372 }
373
374
375 frame os::current_frame() {
376 intptr_t* fp = _get_previous_fp();
377 frame myframe((intptr_t*)os::current_stack_pointer(),
378 (intptr_t*)fp,
379 CAST_FROM_FN_PTR(address, os::current_frame));
380 if (os::is_first_C_frame(&myframe)) {
381 // stack is not walkable
382 return frame(NULL, NULL, NULL);
383 } else {
384 return os::get_sender_for_C_frame(&myframe);
385 }
386 }
387
388 // Utility functions
389
390 // From IA32 System Programming Guide
391 enum {
392 trap_page_fault = 0xE
393 };
394
395 extern "C" void Fetch32PFI () ;
396 extern "C" void Fetch32Resume () ;
397 #ifdef AMD64
398 extern "C" void FetchNPFI () ;
399 extern "C" void FetchNResume () ;
400 #endif // AMD64
401
402 extern "C" JNIEXPORT int
403 JVM_handle_bsd_signal(int sig,
404 siginfo_t* info,
405 void* ucVoid,
406 int abort_if_unrecognized) {
407 ucontext_t* uc = (ucontext_t*) ucVoid;
408
409 Thread* t = ThreadLocalStorage::get_thread_slow();
410
411 SignalHandlerMark shm(t);
412
413 // Note: it's not uncommon that JNI code uses signal/sigset to install
414 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
415 // or have a SIGILL handler when detecting CPU type). When that happens,
416 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To
417 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
418 // that do not require siginfo/ucontext first.
419
420 if (sig == SIGPIPE || sig == SIGXFSZ) {
421 // allow chained handler to go first
422 if (os::Bsd::chained_handler(sig, info, ucVoid)) {
423 return true;
424 } else {
425 if (PrintMiscellaneous && (WizardMode || Verbose)) {
426 char buf[64];
427 warning("Ignoring %s - see bugs 4229104 or 646499219",
428 os::exception_name(sig, buf, sizeof(buf)));
429 }
430 return true;
431 }
432 }
433
434 JavaThread* thread = NULL;
435 VMThread* vmthread = NULL;
436 if (os::Bsd::signal_handlers_are_installed) {
437 if (t != NULL ){
438 if(t->is_Java_thread()) {
439 thread = (JavaThread*)t;
440 }
441 else if(t->is_VM_thread()){
442 vmthread = (VMThread *)t;
443 }
444 }
445 }
446 /*
447 NOTE: does not seem to work on bsd.
448 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
449 // can't decode this kind of signal
450 info = NULL;
451 } else {
452 assert(sig == info->si_signo, "bad siginfo");
453 }
454 */
455 // decide if this trap can be handled by a stub
456 address stub = NULL;
457
458 address pc = NULL;
459
460 //%note os_trap_1
461 if (info != NULL && uc != NULL && thread != NULL) {
462 pc = (address) os::Bsd::ucontext_get_pc(uc);
463
464 if (pc == (address) Fetch32PFI) {
465 uc->context_pc = intptr_t(Fetch32Resume) ;
466 return 1 ;
467 }
468 #ifdef AMD64
469 if (pc == (address) FetchNPFI) {
470 uc->context_pc = intptr_t (FetchNResume) ;
471 return 1 ;
472 }
473 #endif // AMD64
474
475 // Handle ALL stack overflow variations here
476 if (sig == SIGSEGV || sig == SIGBUS) {
477 address addr = (address) info->si_addr;
478
479 // check if fault address is within thread stack
480 if (addr < thread->stack_base() &&
481 addr >= thread->stack_base() - thread->stack_size()) {
482 // stack overflow
483 if (thread->in_stack_yellow_zone(addr)) {
484 thread->disable_stack_yellow_zone();
485 if (thread->thread_state() == _thread_in_Java) {
486 // Throw a stack overflow exception. Guard pages will be reenabled
487 // while unwinding the stack.
488 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
489 } else {
490 // Thread was in the vm or native code. Return and try to finish.
491 return 1;
492 }
493 } else if (thread->in_stack_red_zone(addr)) {
494 // Fatal red zone violation. Disable the guard pages and fall through
495 // to handle_unexpected_exception way down below.
496 thread->disable_stack_red_zone();
497 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
498 #ifndef _ALLBSD_SOURCE
499 } else {
500 // Accessing stack address below sp may cause SEGV if current
501 // thread has MAP_GROWSDOWN stack. This should only happen when
502 // current thread was created by user code with MAP_GROWSDOWN flag
503 // and then attached to VM. See notes in os_bsd.cpp.
504 if (thread->osthread()->expanding_stack() == 0) {
505 thread->osthread()->set_expanding_stack();
506 if (os::Bsd::manually_expand_stack(thread, addr)) {
507 thread->osthread()->clear_expanding_stack();
508 return 1;
509 }
510 thread->osthread()->clear_expanding_stack();
511 } else {
512 fatal("recursive segv. expanding stack.");
513 }
514 #endif
515 }
516 }
517 }
518
519 // We test if stub is already set (by the stack overflow code
520 // above) so it is not overwritten by the code that follows. This
521 // check is not required on other platforms, because on other
522 // platforms we check for SIGSEGV only or SIGBUS only, where here
523 // we have to check for both SIGSEGV and SIGBUS.
524 if (thread->thread_state() == _thread_in_Java && stub == NULL) {
525 // Java thread running in Java code => find exception handler if any
526 // a fault inside compiled code, the interpreter, or a stub
527
528 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) {
529 stub = SharedRuntime::get_poll_stub(pc);
530 #if defined(__APPLE__)
531 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions.
532 // 64-bit Darwin may also use a SIGBUS (seen with compressed oops).
533 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from
534 // being called, so only do so if the implicit NULL check is not necessary.
535 } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
536 #else
537 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
538 #endif
539 // BugId 4454115: A read from a MappedByteBuffer can fault
540 // here if the underlying file has been truncated.
541 // Do not crash the VM in such a case.
542 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
543 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
544 if (nm != NULL && nm->has_unsafe_access()) {
545 stub = StubRoutines::handler_for_unsafe_access();
546 }
547 }
548 else
549
550 #ifdef AMD64
551 if (sig == SIGFPE &&
552 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
553 stub =
554 SharedRuntime::
555 continuation_for_implicit_exception(thread,
556 pc,
557 SharedRuntime::
558 IMPLICIT_DIVIDE_BY_ZERO);
559 #ifdef __APPLE__
560 } else if (sig == SIGFPE && info->si_code == FPE_NOOP) {
561 int op = pc[0];
562
563 // Skip REX
564 if ((pc[0] & 0xf0) == 0x40) {
565 op = pc[1];
566 } else {
567 op = pc[0];
568 }
569
570 // Check for IDIV
571 if (op == 0xF7) {
572 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO);
573 } else {
574 // TODO: handle more cases if we are using other x86 instructions
575 // that can generate SIGFPE signal.
576 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
577 fatal("please update this code.");
578 }
579 #endif /* __APPLE__ */
580
581 #else
582 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) {
583 // HACK: si_code does not work on bsd 2.2.12-20!!!
584 int op = pc[0];
585 if (op == 0xDB) {
586 // FIST
587 // TODO: The encoding of D2I in i486.ad can cause an exception
588 // prior to the fist instruction if there was an invalid operation
589 // pending. We want to dismiss that exception. From the win_32
590 // side it also seems that if it really was the fist causing
591 // the exception that we do the d2i by hand with different
592 // rounding. Seems kind of weird.
593 // NOTE: that we take the exception at the NEXT floating point instruction.
594 assert(pc[0] == 0xDB, "not a FIST opcode");
595 assert(pc[1] == 0x14, "not a FIST opcode");
596 assert(pc[2] == 0x24, "not a FIST opcode");
597 return true;
598 } else if (op == 0xF7) {
599 // IDIV
600 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
601 } else {
602 // TODO: handle more cases if we are using other x86 instructions
603 // that can generate SIGFPE signal on bsd.
604 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
605 fatal("please update this code.");
606 }
607 #endif // AMD64
608 } else if ((sig == SIGSEGV || sig == SIGBUS) &&
609 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
610 // Determination of interpreter/vtable stub/compiled code null exception
611 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
612 }
613 } else if (thread->thread_state() == _thread_in_vm &&
614 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
615 thread->doing_unsafe_access()) {
616 stub = StubRoutines::handler_for_unsafe_access();
617 }
618
619 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
620 // and the heap gets shrunk before the field access.
621 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
622 address addr = JNI_FastGetField::find_slowcase_pc(pc);
623 if (addr != (address)-1) {
624 stub = addr;
625 }
626 }
627
628 // Check to see if we caught the safepoint code in the
629 // process of write protecting the memory serialization page.
630 // It write enables the page immediately after protecting it
631 // so we can just return to retry the write.
632 if ((sig == SIGSEGV || sig == SIGBUS) &&
633 os::is_memory_serialize_page(thread, (address) info->si_addr)) {
634 // Block current thread until the memory serialize page permission restored.
635 os::block_on_serialize_page_trap();
636 return true;
637 }
638 }
639
640 #ifndef AMD64
641 // Execution protection violation
642 //
643 // This should be kept as the last step in the triage. We don't
644 // have a dedicated trap number for a no-execute fault, so be
645 // conservative and allow other handlers the first shot.
646 //
647 // Note: We don't test that info->si_code == SEGV_ACCERR here.
648 // this si_code is so generic that it is almost meaningless; and
649 // the si_code for this condition may change in the future.
650 // Furthermore, a false-positive should be harmless.
651 if (UnguardOnExecutionViolation > 0 &&
652 (sig == SIGSEGV || sig == SIGBUS) &&
653 uc->context_trapno == trap_page_fault) {
654 int page_size = os::vm_page_size();
655 address addr = (address) info->si_addr;
656 address pc = os::Bsd::ucontext_get_pc(uc);
657 // Make sure the pc and the faulting address are sane.
658 //
659 // If an instruction spans a page boundary, and the page containing
660 // the beginning of the instruction is executable but the following
661 // page is not, the pc and the faulting address might be slightly
662 // different - we still want to unguard the 2nd page in this case.
663 //
664 // 15 bytes seems to be a (very) safe value for max instruction size.
665 bool pc_is_near_addr =
666 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
667 bool instr_spans_page_boundary =
668 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
669 (intptr_t) page_size) > 0);
670
671 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
672 static volatile address last_addr =
673 (address) os::non_memory_address_word();
674
675 // In conservative mode, don't unguard unless the address is in the VM
676 if (addr != last_addr &&
677 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
678
679 // Set memory to RWX and retry
680 address page_start =
681 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
682 bool res = os::protect_memory((char*) page_start, page_size,
683 os::MEM_PROT_RWX);
684
685 if (PrintMiscellaneous && Verbose) {
686 char buf[256];
687 jio_snprintf(buf, sizeof(buf), "Execution protection violation "
688 "at " INTPTR_FORMAT
689 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
690 page_start, (res ? "success" : "failed"), errno);
691 tty->print_raw_cr(buf);
692 }
693 stub = pc;
694
695 // Set last_addr so if we fault again at the same address, we don't end
696 // up in an endless loop.
697 //
698 // There are two potential complications here. Two threads trapping at
699 // the same address at the same time could cause one of the threads to
700 // think it already unguarded, and abort the VM. Likely very rare.
701 //
702 // The other race involves two threads alternately trapping at
703 // different addresses and failing to unguard the page, resulting in
704 // an endless loop. This condition is probably even more unlikely than
705 // the first.
706 //
707 // Although both cases could be avoided by using locks or thread local
708 // last_addr, these solutions are unnecessary complication: this
709 // handler is a best-effort safety net, not a complete solution. It is
710 // disabled by default and should only be used as a workaround in case
711 // we missed any no-execute-unsafe VM code.
712
713 last_addr = addr;
714 }
715 }
716 }
717 #endif // !AMD64
718
719 if (stub != NULL) {
720 // save all thread context in case we need to restore it
721 if (thread != NULL) thread->set_saved_exception_pc(pc);
722
723 uc->context_pc = (intptr_t)stub;
724 return true;
725 }
726
727 // signal-chaining
728 if (os::Bsd::chained_handler(sig, info, ucVoid)) {
729 return true;
730 }
731
732 if (!abort_if_unrecognized) {
733 // caller wants another chance, so give it to him
734 return false;
735 }
736
737 if (pc == NULL && uc != NULL) {
738 pc = os::Bsd::ucontext_get_pc(uc);
739 }
740
741 // unmask current signal
742 sigset_t newset;
743 sigemptyset(&newset);
744 sigaddset(&newset, sig);
745 sigprocmask(SIG_UNBLOCK, &newset, NULL);
746
747 VMError err(t, sig, pc, info, ucVoid);
748 err.report_and_die();
749
750 ShouldNotReachHere();
751 }
752
753 #ifdef _ALLBSD_SOURCE
754 // From solaris_i486.s ported to bsd_i486.s
755 extern "C" void fixcw();
756 #endif
757
758 void os::Bsd::init_thread_fpu_state(void) {
759 #ifndef AMD64
760 # ifdef _ALLBSD_SOURCE
761 // Set fpu to 53 bit precision. This happens too early to use a stub.
762 fixcw();
763 # else
764 // set fpu to 53 bit precision
765 set_fpu_control_word(0x27f);
766 # endif
767 #endif // !AMD64
768 }
769
770 #ifndef _ALLBSD_SOURCE
771 int os::Bsd::get_fpu_control_word(void) {
772 #ifdef AMD64
773 return 0;
774 #else
775 int fpu_control;
776 _FPU_GETCW(fpu_control);
777 return fpu_control & 0xffff;
778 #endif // AMD64
779 }
780
781 void os::Bsd::set_fpu_control_word(int fpu_control) {
782 #ifndef AMD64
783 _FPU_SETCW(fpu_control);
784 #endif // !AMD64
785 }
786 #endif
787
788 // Check that the bsd kernel version is 2.4 or higher since earlier
789 // versions do not support SSE without patches.
790 bool os::supports_sse() {
791 #if defined(AMD64) || defined(_ALLBSD_SOURCE)
792 return true;
793 #else
794 struct utsname uts;
795 if( uname(&uts) != 0 ) return false; // uname fails?
796 char *minor_string;
797 int major = strtol(uts.release,&minor_string,10);
798 int minor = strtol(minor_string+1,NULL,10);
799 bool result = (major > 2 || (major==2 && minor >= 4));
800 #ifndef PRODUCT
801 if (PrintMiscellaneous && Verbose) {
802 tty->print("OS version is %d.%d, which %s support SSE/SSE2\n",
803 major,minor, result ? "DOES" : "does NOT");
804 }
805 #endif
806 return result;
807 #endif // AMD64
808 }
809
810 bool os::is_allocatable(size_t bytes) {
811 #ifdef AMD64
812 // unused on amd64?
813 return true;
814 #else
815
816 if (bytes < 2 * G) {
817 return true;
818 }
819
820 char* addr = reserve_memory(bytes, NULL);
821
822 if (addr != NULL) {
823 release_memory(addr, bytes);
824 }
825
826 return addr != NULL;
827 #endif // AMD64
828 }
829
830 ////////////////////////////////////////////////////////////////////////////////
831 // thread stack
832
833 #ifdef AMD64
834 size_t os::Bsd::min_stack_allowed = 64 * K;
835
836 // amd64: pthread on amd64 is always in floating stack mode
837 bool os::Bsd::supports_variable_stack_size() { return true; }
838 #else
839 size_t os::Bsd::min_stack_allowed = (48 DEBUG_ONLY(+4))*K;
840
841 #ifdef __GNUC__
842 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;})
843 #endif
844
845 #ifdef _ALLBSD_SOURCE
846 bool os::Bsd::supports_variable_stack_size() { return true; }
847 #else
848 // Test if pthread library can support variable thread stack size. BsdThreads
849 // in fixed stack mode allocates 2M fixed slot for each thread. BsdThreads
850 // in floating stack mode and NPTL support variable stack size.
851 bool os::Bsd::supports_variable_stack_size() {
852 if (os::Bsd::is_NPTL()) {
853 // NPTL, yes
854 return true;
855
856 } else {
857 // Note: We can't control default stack size when creating a thread.
858 // If we use non-default stack size (pthread_attr_setstacksize), both
859 // floating stack and non-floating stack BsdThreads will return the
860 // same value. This makes it impossible to implement this function by
861 // detecting thread stack size directly.
862 //
863 // An alternative approach is to check %gs. Fixed-stack BsdThreads
864 // do not use %gs, so its value is 0. Floating-stack BsdThreads use
865 // %gs (either as LDT selector or GDT selector, depending on kernel)
866 // to access thread specific data.
867 //
868 // Note that %gs is a reserved glibc register since early 2001, so
869 // applications are not allowed to change its value (Ulrich Drepper from
870 // Redhat confirmed that all known offenders have been modified to use
871 // either %fs or TSD). In the worst case scenario, when VM is embedded in
872 // a native application that plays with %gs, we might see non-zero %gs
873 // even BsdThreads is running in fixed stack mode. As the result, we'll
874 // return true and skip _thread_safety_check(), so we may not be able to
875 // detect stack-heap collisions. But otherwise it's harmless.
876 //
877 #ifdef __GNUC__
878 return (GET_GS() != 0);
879 #else
880 return false;
881 #endif
882 }
883 }
884 #endif
885 #endif // AMD64
886
887 // return default stack size for thr_type
888 size_t os::Bsd::default_stack_size(os::ThreadType thr_type) {
889 // default stack size (compiler thread needs larger stack)
890 #ifdef AMD64
891 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
892 #else
893 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
894 #endif // AMD64
895 return s;
896 }
897
898 size_t os::Bsd::default_guard_size(os::ThreadType thr_type) {
899 // Creating guard page is very expensive. Java thread has HotSpot
900 // guard page, only enable glibc guard page for non-Java threads.
901 return (thr_type == java_thread ? 0 : page_size());
902 }
903
904 // Java thread:
905 //
906 // Low memory addresses
907 // +------------------------+
908 // | |\ JavaThread created by VM does not have glibc
909 // | glibc guard page | - guard, attached Java thread usually has
910 // | |/ 1 page glibc guard.
911 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
912 // | |\
913 // | HotSpot Guard Pages | - red and yellow pages
914 // | |/
915 // +------------------------+ JavaThread::stack_yellow_zone_base()
916 // | |\
917 // | Normal Stack | -
918 // | |/
919 // P2 +------------------------+ Thread::stack_base()
920 //
921 // Non-Java thread:
922 //
923 // Low memory addresses
924 // +------------------------+
925 // | |\
926 // | glibc guard page | - usually 1 page
927 // | |/
928 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
929 // | |\
930 // | Normal Stack | -
931 // | |/
932 // P2 +------------------------+ Thread::stack_base()
933 //
934 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
935 // pthread_attr_getstack()
936
937 static void current_stack_region(address * bottom, size_t * size) {
938 #ifdef __APPLE__
939 pthread_t self = pthread_self();
940 void *stacktop = pthread_get_stackaddr_np(self);
941 *size = pthread_get_stacksize_np(self);
942 *bottom = (address) stacktop - *size;
943 #elif defined(__OpenBSD__)
944 stack_t ss;
945 int rslt = pthread_stackseg_np(pthread_self(), &ss);
946
947 if (rslt != 0)
948 fatal(err_msg("pthread_stackseg_np failed with err = %d", rslt));
949
950 *bottom = (address)((char *)ss.ss_sp - ss.ss_size);
951 *size = ss.ss_size;
952 #elif defined(_ALLBSD_SOURCE)
953 pthread_attr_t attr;
954
955 int rslt = pthread_attr_init(&attr);
956
957 // JVM needs to know exact stack location, abort if it fails
958 if (rslt != 0)
959 fatal(err_msg("pthread_attr_init failed with err = %d", rslt));
960
961 rslt = pthread_attr_get_np(pthread_self(), &attr);
962
963 if (rslt != 0)
964 fatal(err_msg("pthread_attr_get_np failed with err = %d", rslt));
965
966 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 ||
967 pthread_attr_getstacksize(&attr, size) != 0) {
968 fatal("Can not locate current stack attributes!");
969 }
970
971 pthread_attr_destroy(&attr);
972 #else
973 if (os::Bsd::is_initial_thread()) {
974 // initial thread needs special handling because pthread_getattr_np()
975 // may return bogus value.
976 *bottom = os::Bsd::initial_thread_stack_bottom();
977 *size = os::Bsd::initial_thread_stack_size();
978 } else {
979 pthread_attr_t attr;
980
981 int rslt = pthread_getattr_np(pthread_self(), &attr);
982
983 // JVM needs to know exact stack location, abort if it fails
984 if (rslt != 0) {
985 if (rslt == ENOMEM) {
986 vm_exit_out_of_memory(0, "pthread_getattr_np");
987 } else {
988 fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt));
989 }
990 }
991
992 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
993 fatal("Can not locate current stack attributes!");
994 }
995
996 pthread_attr_destroy(&attr);
997
998 }
999 #endif
1000 assert(os::current_stack_pointer() >= *bottom &&
1001 os::current_stack_pointer() < *bottom + *size, "just checking");
1002 }
1003
1004 address os::current_stack_base() {
1005 address bottom;
1006 size_t size;
1007 current_stack_region(&bottom, &size);
1008 return (bottom + size);
1009 }
1010
1011 size_t os::current_stack_size() {
1012 // stack size includes normal stack and HotSpot guard pages
1013 address bottom;
1014 size_t size;
1015 current_stack_region(&bottom, &size);
1016 return size;
1017 }
1018
1019 /////////////////////////////////////////////////////////////////////////////
1020 // helper functions for fatal error handler
1021
1022 void os::print_context(outputStream *st, void *context) {
1023 if (context == NULL) return;
1024
1025 ucontext_t *uc = (ucontext_t*)context;
1026 st->print_cr("Registers:");
1027 #ifdef AMD64
1028 st->print( "RAX=" INTPTR_FORMAT, uc->context_rax);
1029 st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx);
1030 st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx);
1031 st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx);
1032 st->cr();
1033 st->print( "RSP=" INTPTR_FORMAT, uc->context_rsp);
1034 st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp);
1035 st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi);
1036 st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi);
1037 st->cr();
1038 st->print( "R8 =" INTPTR_FORMAT, uc->context_r8);
1039 st->print(", R9 =" INTPTR_FORMAT, uc->context_r9);
1040 st->print(", R10=" INTPTR_FORMAT, uc->context_r10);
1041 st->print(", R11=" INTPTR_FORMAT, uc->context_r11);
1042 st->cr();
1043 st->print( "R12=" INTPTR_FORMAT, uc->context_r12);
1044 st->print(", R13=" INTPTR_FORMAT, uc->context_r13);
1045 st->print(", R14=" INTPTR_FORMAT, uc->context_r14);
1046 st->print(", R15=" INTPTR_FORMAT, uc->context_r15);
1047 st->cr();
1048 st->print( "RIP=" INTPTR_FORMAT, uc->context_rip);
1049 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags);
1050 st->print(", ERR=" INTPTR_FORMAT, uc->context_err);
1051 st->cr();
1052 st->print(" TRAPNO=" INTPTR_FORMAT, uc->context_trapno);
1053 #else
1054 st->print( "EAX=" INTPTR_FORMAT, uc->context_eax);
1055 st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx);
1056 st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx);
1057 st->print(", EDX=" INTPTR_FORMAT, uc->context_edx);
1058 st->cr();
1059 st->print( "ESP=" INTPTR_FORMAT, uc->context_esp);
1060 st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp);
1061 st->print(", ESI=" INTPTR_FORMAT, uc->context_esi);
1062 st->print(", EDI=" INTPTR_FORMAT, uc->context_edi);
1063 st->cr();
1064 st->print( "EIP=" INTPTR_FORMAT, uc->context_eip);
1065 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags);
1066 #endif // AMD64
1067 st->cr();
1068 st->cr();
1069
1070 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc);
1071 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
1072 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
1073 st->cr();
1074
1075 // Note: it may be unsafe to inspect memory near pc. For example, pc may
1076 // point to garbage if entry point in an nmethod is corrupted. Leave
1077 // this at the end, and hope for the best.
1078 address pc = os::Bsd::ucontext_get_pc(uc);
1079 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
1080 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
1081 }
1082
1083 void os::print_register_info(outputStream *st, void *context) {
1084 if (context == NULL) return;
1085
1086 ucontext_t *uc = (ucontext_t*)context;
1087
1088 st->print_cr("Register to memory mapping:");
1089 st->cr();
1090
1091 // this is horrendously verbose but the layout of the registers in the
1092 // context does not match how we defined our abstract Register set, so
1093 // we can't just iterate through the gregs area
1094
1095 // this is only for the "general purpose" registers
1096
1097 #ifdef AMD64
1098 st->print("RAX="); print_location(st, uc->context_rax);
1099 st->print("RBX="); print_location(st, uc->context_rbx);
1100 st->print("RCX="); print_location(st, uc->context_rcx);
1101 st->print("RDX="); print_location(st, uc->context_rdx);
1102 st->print("RSP="); print_location(st, uc->context_rsp);
1103 st->print("RBP="); print_location(st, uc->context_rbp);
1104 st->print("RSI="); print_location(st, uc->context_rsi);
1105 st->print("RDI="); print_location(st, uc->context_rdi);
1106 st->print("R8 ="); print_location(st, uc->context_r8);
1107 st->print("R9 ="); print_location(st, uc->context_r9);
1108 st->print("R10="); print_location(st, uc->context_r10);
1109 st->print("R11="); print_location(st, uc->context_r11);
1110 st->print("R12="); print_location(st, uc->context_r12);
1111 st->print("R13="); print_location(st, uc->context_r13);
1112 st->print("R14="); print_location(st, uc->context_r14);
1113 st->print("R15="); print_location(st, uc->context_r15);
1114 #else
1115 st->print("EAX="); print_location(st, uc->context_eax);
1116 st->print("EBX="); print_location(st, uc->context_ebx);
1117 st->print("ECX="); print_location(st, uc->context_ecx);
1118 st->print("EDX="); print_location(st, uc->context_edx);
1119 st->print("ESP="); print_location(st, uc->context_esp);
1120 st->print("EBP="); print_location(st, uc->context_ebp);
1121 st->print("ESI="); print_location(st, uc->context_esi);
1122 st->print("EDI="); print_location(st, uc->context_edi);
1123 #endif // AMD64
1124
1125 st->cr();
1126 }
1127
1128 void os::setup_fpu() {
1129 #ifndef AMD64
1130 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
1131 __asm__ volatile ( "fldcw (%0)" :
1132 : "r" (fpu_cntrl) : "memory");
1133 #endif // !AMD64
1134 }
1135
1136 #ifndef PRODUCT
1137 void os::verify_stack_alignment() {
1138 }
1139 #endif