1 /*
2 * Copyright (c) 1999, 2014, 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 #ifdef __FreeBSD__
78 # include <sys/sysctl.h>
79 # include <sys/procctl.h>
80 #ifndef PROC_STACKGAP_STATUS
81 #define PROC_STACKGAP_STATUS 18
82 #endif
83 #ifndef PROC_STACKGAP_DISABLE
84 #define PROC_STACKGAP_DISABLE 0x0002
85 #endif
86 #endif /* __FreeBSD__ */
87
88 #if !defined(__APPLE__) && !defined(__NetBSD__)
89 # include <pthread_np.h>
90 #endif
91
92 // needed by current_stack_region() workaround for Mavericks
93 #if defined(__APPLE__)
94 # include <errno.h>
95 # include <sys/types.h>
96 # include <sys/sysctl.h>
97 # define DEFAULT_MAIN_THREAD_STACK_PAGES 2048
98 # define OS_X_10_9_0_KERNEL_MAJOR_VERSION 13
99 #endif
100
101 #ifdef AMD64
102 #define SPELL_REG_SP "rsp"
103 #define SPELL_REG_FP "rbp"
104 #else
105 #define SPELL_REG_SP "esp"
106 #define SPELL_REG_FP "ebp"
107 #endif // AMD64
108
109 #if defined(__FreeBSD__) || defined(__DragonFly__)
110 # define context_trapno uc_mcontext.mc_trapno
111 # ifdef AMD64
112 # define context_pc uc_mcontext.mc_rip
113 # define context_sp uc_mcontext.mc_rsp
114 # define context_fp uc_mcontext.mc_rbp
115 # define context_rip uc_mcontext.mc_rip
116 # define context_rsp uc_mcontext.mc_rsp
117 # define context_rbp uc_mcontext.mc_rbp
118 # define context_rax uc_mcontext.mc_rax
119 # define context_rbx uc_mcontext.mc_rbx
120 # define context_rcx uc_mcontext.mc_rcx
121 # define context_rdx uc_mcontext.mc_rdx
122 # define context_rsi uc_mcontext.mc_rsi
123 # define context_rdi uc_mcontext.mc_rdi
124 # define context_r8 uc_mcontext.mc_r8
125 # define context_r9 uc_mcontext.mc_r9
126 # define context_r10 uc_mcontext.mc_r10
127 # define context_r11 uc_mcontext.mc_r11
128 # define context_r12 uc_mcontext.mc_r12
129 # define context_r13 uc_mcontext.mc_r13
130 # define context_r14 uc_mcontext.mc_r14
131 # define context_r15 uc_mcontext.mc_r15
132 # define context_flags uc_mcontext.mc_flags
133 # define context_err uc_mcontext.mc_err
134 # else
135 # define context_pc uc_mcontext.mc_eip
136 # define context_sp uc_mcontext.mc_esp
137 # define context_fp uc_mcontext.mc_ebp
138 # define context_eip uc_mcontext.mc_eip
139 # define context_esp uc_mcontext.mc_esp
140 # define context_eax uc_mcontext.mc_eax
141 # define context_ebx uc_mcontext.mc_ebx
142 # define context_ecx uc_mcontext.mc_ecx
143 # define context_edx uc_mcontext.mc_edx
144 # define context_ebp uc_mcontext.mc_ebp
145 # define context_esi uc_mcontext.mc_esi
146 # define context_edi uc_mcontext.mc_edi
147 # define context_eflags uc_mcontext.mc_eflags
148 # define context_trapno uc_mcontext.mc_trapno
149 # endif
150 #endif
151
152 #ifdef __APPLE__
153 # if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
154 // 10.5 UNIX03 member name prefixes
155 #define DU3_PREFIX(s, m) __ ## s.__ ## m
156 # else
157 #define DU3_PREFIX(s, m) s ## . ## m
158 # endif
159
160 # ifdef AMD64
161 # define context_pc context_rip
162 # define context_sp context_rsp
163 # define context_fp context_rbp
164 # define context_rip uc_mcontext->DU3_PREFIX(ss,rip)
165 # define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp)
166 # define context_rax uc_mcontext->DU3_PREFIX(ss,rax)
167 # define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx)
168 # define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx)
169 # define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx)
170 # define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp)
171 # define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi)
172 # define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi)
173 # define context_r8 uc_mcontext->DU3_PREFIX(ss,r8)
174 # define context_r9 uc_mcontext->DU3_PREFIX(ss,r9)
175 # define context_r10 uc_mcontext->DU3_PREFIX(ss,r10)
176 # define context_r11 uc_mcontext->DU3_PREFIX(ss,r11)
177 # define context_r12 uc_mcontext->DU3_PREFIX(ss,r12)
178 # define context_r13 uc_mcontext->DU3_PREFIX(ss,r13)
179 # define context_r14 uc_mcontext->DU3_PREFIX(ss,r14)
180 # define context_r15 uc_mcontext->DU3_PREFIX(ss,r15)
181 # define context_flags uc_mcontext->DU3_PREFIX(ss,rflags)
182 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno)
183 # define context_err uc_mcontext->DU3_PREFIX(es,err)
184 # else
185 # define context_pc context_eip
186 # define context_sp context_esp
187 # define context_fp context_ebp
188 # define context_eip uc_mcontext->DU3_PREFIX(ss,eip)
189 # define context_esp uc_mcontext->DU3_PREFIX(ss,esp)
190 # define context_eax uc_mcontext->DU3_PREFIX(ss,eax)
191 # define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx)
192 # define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx)
193 # define context_edx uc_mcontext->DU3_PREFIX(ss,edx)
194 # define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp)
195 # define context_esi uc_mcontext->DU3_PREFIX(ss,esi)
196 # define context_edi uc_mcontext->DU3_PREFIX(ss,edi)
197 # define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags)
198 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno)
199 # endif
200 #endif
201
202 #ifdef __OpenBSD__
203 # define context_trapno sc_trapno
204 # ifdef AMD64
205 # define context_pc sc_rip
206 # define context_sp sc_rsp
207 # define context_fp sc_rbp
208 # define context_rip sc_rip
209 # define context_rsp sc_rsp
210 # define context_rbp sc_rbp
211 # define context_rax sc_rax
212 # define context_rbx sc_rbx
213 # define context_rcx sc_rcx
214 # define context_rdx sc_rdx
215 # define context_rsi sc_rsi
216 # define context_rdi sc_rdi
217 # define context_r8 sc_r8
218 # define context_r9 sc_r9
219 # define context_r10 sc_r10
220 # define context_r11 sc_r11
221 # define context_r12 sc_r12
222 # define context_r13 sc_r13
223 # define context_r14 sc_r14
224 # define context_r15 sc_r15
225 # define context_flags sc_rflags
226 # define context_err sc_err
227 # else
228 # define context_pc sc_eip
229 # define context_sp sc_esp
230 # define context_fp sc_ebp
231 # define context_eip sc_eip
232 # define context_esp sc_esp
233 # define context_eax sc_eax
234 # define context_ebx sc_ebx
235 # define context_ecx sc_ecx
236 # define context_edx sc_edx
237 # define context_ebp sc_ebp
238 # define context_esi sc_esi
239 # define context_edi sc_edi
240 # define context_eflags sc_eflags
241 # define context_trapno sc_trapno
242 # endif
243 #endif
244
245 #ifdef __NetBSD__
246 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO]
247 # ifdef AMD64
248 # define __register_t __greg_t
249 # define context_pc uc_mcontext.__gregs[_REG_RIP]
250 # define context_sp uc_mcontext.__gregs[_REG_URSP]
251 # define context_fp uc_mcontext.__gregs[_REG_RBP]
252 # define context_rip uc_mcontext.__gregs[_REG_RIP]
253 # define context_rsp uc_mcontext.__gregs[_REG_URSP]
254 # define context_rax uc_mcontext.__gregs[_REG_RAX]
255 # define context_rbx uc_mcontext.__gregs[_REG_RBX]
256 # define context_rcx uc_mcontext.__gregs[_REG_RCX]
257 # define context_rdx uc_mcontext.__gregs[_REG_RDX]
258 # define context_rbp uc_mcontext.__gregs[_REG_RBP]
259 # define context_rsi uc_mcontext.__gregs[_REG_RSI]
260 # define context_rdi uc_mcontext.__gregs[_REG_RDI]
261 # define context_r8 uc_mcontext.__gregs[_REG_R8]
262 # define context_r9 uc_mcontext.__gregs[_REG_R9]
263 # define context_r10 uc_mcontext.__gregs[_REG_R10]
264 # define context_r11 uc_mcontext.__gregs[_REG_R11]
265 # define context_r12 uc_mcontext.__gregs[_REG_R12]
266 # define context_r13 uc_mcontext.__gregs[_REG_R13]
267 # define context_r14 uc_mcontext.__gregs[_REG_R14]
268 # define context_r15 uc_mcontext.__gregs[_REG_R15]
269 # define context_flags uc_mcontext.__gregs[_REG_RFL]
270 # define context_err uc_mcontext.__gregs[_REG_ERR]
271 # else
272 # define context_pc uc_mcontext.__gregs[_REG_EIP]
273 # define context_sp uc_mcontext.__gregs[_REG_UESP]
274 # define context_fp uc_mcontext.__gregs[_REG_EBP]
275 # define context_eip uc_mcontext.__gregs[_REG_EIP]
276 # define context_esp uc_mcontext.__gregs[_REG_UESP]
277 # define context_eax uc_mcontext.__gregs[_REG_EAX]
278 # define context_ebx uc_mcontext.__gregs[_REG_EBX]
279 # define context_ecx uc_mcontext.__gregs[_REG_ECX]
280 # define context_edx uc_mcontext.__gregs[_REG_EDX]
281 # define context_ebp uc_mcontext.__gregs[_REG_EBP]
282 # define context_esi uc_mcontext.__gregs[_REG_ESI]
283 # define context_edi uc_mcontext.__gregs[_REG_EDI]
284 # define context_eflags uc_mcontext.__gregs[_REG_EFL]
285 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO]
286 # endif
287 #endif
288
289 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
290
current_stack_pointer()291 address os::current_stack_pointer() {
292 #if defined(__clang__) || defined(__llvm__)
293 register void *esp;
294 __asm__("mov %%" SPELL_REG_SP ", %0" : "=r" (esp));
295 return (address) esp;
296 #elif defined(SPARC_WORKS)
297 register void *esp;
298 __asm__("mov %%" SPELL_REG_SP ", %0" : "=r" (esp));
299 return (address) ((char*)esp + sizeof(long)*2);
300 #else
301 register void *esp __asm__ (SPELL_REG_SP);
302 return (address) esp;
303 #endif
304 }
305
non_memory_address_word()306 char* os::non_memory_address_word() {
307 // Must never look like an address returned by reserve_memory,
308 // even in its subfields (as defined by the CPU immediate fields,
309 // if the CPU splits constants across multiple instructions).
310
311 return (char*) -1;
312 }
313
initialize_thread(Thread * thr)314 void os::initialize_thread(Thread* thr) {
315 // Nothing to do.
316 }
317
ucontext_get_pc(ucontext_t * uc)318 address os::Bsd::ucontext_get_pc(ucontext_t * uc) {
319 return (address)uc->context_pc;
320 }
321
ucontext_get_sp(ucontext_t * uc)322 intptr_t* os::Bsd::ucontext_get_sp(ucontext_t * uc) {
323 return (intptr_t*)uc->context_sp;
324 }
325
ucontext_get_fp(ucontext_t * uc)326 intptr_t* os::Bsd::ucontext_get_fp(ucontext_t * uc) {
327 return (intptr_t*)uc->context_fp;
328 }
329
330 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
331 // is currently interrupted by SIGPROF.
332 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
333 // frames. Currently we don't do that on Bsd, so it's the same as
334 // os::fetch_frame_from_context().
fetch_frame_from_ucontext(Thread * thread,ucontext_t * uc,intptr_t ** ret_sp,intptr_t ** ret_fp)335 ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread,
336 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
337
338 assert(thread != NULL, "just checking");
339 assert(ret_sp != NULL, "just checking");
340 assert(ret_fp != NULL, "just checking");
341
342 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
343 }
344
fetch_frame_from_context(void * ucVoid,intptr_t ** ret_sp,intptr_t ** ret_fp)345 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
346 intptr_t** ret_sp, intptr_t** ret_fp) {
347
348 ExtendedPC epc;
349 ucontext_t* uc = (ucontext_t*)ucVoid;
350
351 if (uc != NULL) {
352 epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc));
353 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc);
354 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc);
355 } else {
356 // construct empty ExtendedPC for return value checking
357 epc = ExtendedPC(NULL);
358 if (ret_sp) *ret_sp = (intptr_t *)NULL;
359 if (ret_fp) *ret_fp = (intptr_t *)NULL;
360 }
361
362 return epc;
363 }
364
fetch_frame_from_context(void * ucVoid)365 frame os::fetch_frame_from_context(void* ucVoid) {
366 intptr_t* sp;
367 intptr_t* fp;
368 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
369 return frame(sp, fp, epc.pc());
370 }
371
372 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get
373 // turned off by -fomit-frame-pointer,
get_sender_for_C_frame(frame * fr)374 frame os::get_sender_for_C_frame(frame* fr) {
375 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
376 }
377
_get_previous_fp()378 intptr_t* _get_previous_fp() {
379 #if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__)
380 register intptr_t **ebp;
381 __asm__("mov %%" SPELL_REG_FP ", %0" : "=r" (ebp));
382 #else
383 register intptr_t **ebp __asm__ (SPELL_REG_FP);
384 #endif
385 return (intptr_t*) *ebp; // we want what it points to.
386 }
387
388
current_frame()389 frame os::current_frame() {
390 intptr_t* fp = _get_previous_fp();
391 frame myframe((intptr_t*)os::current_stack_pointer(),
392 (intptr_t*)fp,
393 CAST_FROM_FN_PTR(address, os::current_frame));
394 if (os::is_first_C_frame(&myframe)) {
395 // stack is not walkable
396 return frame();
397 } else {
398 return os::get_sender_for_C_frame(&myframe);
399 }
400 }
401
402 // Utility functions
403
404 // From IA32 System Programming Guide
405 enum {
406 trap_page_fault = 0xE
407 };
408
409 extern "C" JNIEXPORT int
JVM_handle_bsd_signal(int sig,siginfo_t * info,void * ucVoid,int abort_if_unrecognized)410 JVM_handle_bsd_signal(int sig,
411 siginfo_t* info,
412 void* ucVoid,
413 int abort_if_unrecognized) {
414 ucontext_t* uc = (ucontext_t*) ucVoid;
415
416 Thread* t = ThreadLocalStorage::get_thread_slow();
417
418 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
419 // (no destructors can be run)
420 os::ThreadCrashProtection::check_crash_protection(sig, t);
421
422 SignalHandlerMark shm(t);
423
424 // Note: it's not uncommon that JNI code uses signal/sigset to install
425 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
426 // or have a SIGILL handler when detecting CPU type). When that happens,
427 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To
428 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
429 // that do not require siginfo/ucontext first.
430
431 if (sig == SIGPIPE || sig == SIGXFSZ) {
432 // allow chained handler to go first
433 if (os::Bsd::chained_handler(sig, info, ucVoid)) {
434 return true;
435 } else {
436 if (PrintMiscellaneous && (WizardMode || Verbose)) {
437 char buf[64];
438 warning("Ignoring %s - see bugs 4229104 or 646499219",
439 os::exception_name(sig, buf, sizeof(buf)));
440 }
441 return true;
442 }
443 }
444
445 JavaThread* thread = NULL;
446 VMThread* vmthread = NULL;
447 if (os::Bsd::signal_handlers_are_installed) {
448 if (t != NULL ){
449 if(t->is_Java_thread()) {
450 thread = (JavaThread*)t;
451 }
452 else if(t->is_VM_thread()){
453 vmthread = (VMThread *)t;
454 }
455 }
456 }
457 /*
458 NOTE: does not seem to work on bsd.
459 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
460 // can't decode this kind of signal
461 info = NULL;
462 } else {
463 assert(sig == info->si_signo, "bad siginfo");
464 }
465 */
466 // decide if this trap can be handled by a stub
467 address stub = NULL;
468
469 address pc = NULL;
470
471 //%note os_trap_1
472 if (info != NULL && uc != NULL && thread != NULL) {
473 pc = (address) os::Bsd::ucontext_get_pc(uc);
474
475 if (StubRoutines::is_safefetch_fault(pc)) {
476 uc->context_pc = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc));
477 return 1;
478 }
479
480 // Handle ALL stack overflow variations here
481 if (sig == SIGSEGV || sig == SIGBUS) {
482 address addr = (address) info->si_addr;
483 #ifdef __FreeBSD__
484 /*
485 * Determine whether the kernel stack guard pages have been disabled
486 */
487 int status = 0;
488 int ret = procctl(P_PID, getpid(), PROC_STACKGAP_STATUS, &status);
489
490 /*
491 * Check if the call to procctl(2) failed or the stack guard is not
492 * disabled. Either way, we'll then attempt a workaround.
493 */
494 if (ret == -1 || !(status & PROC_STACKGAP_DISABLE)) {
495 /*
496 * Try to work around the problems caused on FreeBSD where the kernel
497 * may place guard pages above JVM guard pages and prevent the Java
498 * thread stacks growing into the JVM guard pages. The work around
499 * is to determine how many such pages there may be and round down the
500 * fault address so that tests of whether it is in the JVM guard zone
501 * succeed.
502 *
503 * Note that this is a partial workaround at best since the normally
504 * the JVM could then unprotect the reserved area to allow a critical
505 * section to complete. This is not possible if the kernel has
506 * placed guard pages below the reserved area.
507 *
508 * This also suffers from the problem that the
509 * security.bsd.stack_guard_page sysctl is dynamic and may have
510 * changed since the stack was allocated. This is likely to be rare
511 * in practice though.
512 *
513 * What this does do is prevent the JVM crashing on FreeBSD and
514 * instead throwing a StackOverflowError when infinite recursion
515 * is attempted, which is the expected behaviour. Due to it's
516 * limitations though, objects may be in unexpected states when
517 * this occurs.
518 *
519 * A better way to avoid these problems is either to be on a new
520 * enough version of FreeBSD (one that has PROC_STACKGAP_CTL) or set
521 * security.bsd.stack_guard_page to zero.
522 */
523 int guard_pages = 0;
524 size_t size = sizeof(guard_pages);
525 if (sysctlbyname("security.bsd.stack_guard_page",
526 &guard_pages, &size, NULL, 0) == 0 &&
527 guard_pages > 0) {
528 addr -= guard_pages * os::vm_page_size();
529 }
530 }
531 #endif
532
533 // check if fault address is within thread stack
534 if (addr < thread->stack_base() &&
535 addr >= thread->stack_base() - thread->stack_size()) {
536 // stack overflow
537 if (thread->in_stack_yellow_zone(addr)) {
538 thread->disable_stack_yellow_zone();
539 if (thread->thread_state() == _thread_in_Java) {
540 // Throw a stack overflow exception. Guard pages will be reenabled
541 // while unwinding the stack.
542 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
543 } else {
544 // Thread was in the vm or native code. Return and try to finish.
545 return 1;
546 }
547 } else if (thread->in_stack_red_zone(addr)) {
548 // Fatal red zone violation. Disable the guard pages and fall through
549 // to handle_unexpected_exception way down below.
550 thread->disable_stack_red_zone();
551 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
552 }
553 }
554 }
555
556 if ((sig == SIGSEGV || sig == SIGBUS) && VM_Version::is_cpuinfo_segv_addr(pc)) {
557 // Verify that OS save/restore AVX registers.
558 stub = VM_Version::cpuinfo_cont_addr();
559 }
560
561 // We test if stub is already set (by the stack overflow code
562 // above) so it is not overwritten by the code that follows. This
563 // check is not required on other platforms, because on other
564 // platforms we check for SIGSEGV only or SIGBUS only, where here
565 // we have to check for both SIGSEGV and SIGBUS.
566 if (thread->thread_state() == _thread_in_Java && stub == NULL) {
567 // Java thread running in Java code => find exception handler if any
568 // a fault inside compiled code, the interpreter, or a stub
569
570 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) {
571 stub = SharedRuntime::get_poll_stub(pc);
572 #if defined(__APPLE__)
573 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions.
574 // 64-bit Darwin may also use a SIGBUS (seen with compressed oops).
575 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from
576 // being called, so only do so if the implicit NULL check is not necessary.
577 } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
578 #else
579 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
580 #endif
581 // BugId 4454115: A read from a MappedByteBuffer can fault
582 // here if the underlying file has been truncated.
583 // Do not crash the VM in such a case.
584 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
585 nmethod* nm = (cb != NULL && cb->is_nmethod()) ? (nmethod*)cb : NULL;
586 if (nm != NULL && nm->has_unsafe_access()) {
587 stub = StubRoutines::handler_for_unsafe_access();
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 #if defined(__FreeBSD__) || defined(__DragonFly__)
657 (sig == SIGBUS || sig == SIGSEGV) &&
658 #else
659 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
660 #endif
661 thread->doing_unsafe_access()) {
662 stub = StubRoutines::handler_for_unsafe_access();
663 }
664
665 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
666 // and the heap gets shrunk before the field access.
667 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
668 address addr = JNI_FastGetField::find_slowcase_pc(pc);
669 if (addr != (address)-1) {
670 stub = addr;
671 }
672 }
673
674 // Check to see if we caught the safepoint code in the
675 // process of write protecting the memory serialization page.
676 // It write enables the page immediately after protecting it
677 // so we can just return to retry the write.
678 if ((sig == SIGSEGV || sig == SIGBUS) &&
679 os::is_memory_serialize_page(thread, (address) info->si_addr)) {
680 // Block current thread until the memory serialize page permission restored.
681 os::block_on_serialize_page_trap();
682 return true;
683 }
684 }
685
686 #ifndef AMD64
687 // Execution protection violation
688 //
689 // This should be kept as the last step in the triage. We don't
690 // have a dedicated trap number for a no-execute fault, so be
691 // conservative and allow other handlers the first shot.
692 //
693 // Note: We don't test that info->si_code == SEGV_ACCERR here.
694 // this si_code is so generic that it is almost meaningless; and
695 // the si_code for this condition may change in the future.
696 // Furthermore, a false-positive should be harmless.
697 if (UnguardOnExecutionViolation > 0 &&
698 (sig == SIGSEGV || sig == SIGBUS) &&
699 uc->context_trapno == trap_page_fault) {
700 int page_size = os::vm_page_size();
701 address addr = (address) info->si_addr;
702 address pc = os::Bsd::ucontext_get_pc(uc);
703 // Make sure the pc and the faulting address are sane.
704 //
705 // If an instruction spans a page boundary, and the page containing
706 // the beginning of the instruction is executable but the following
707 // page is not, the pc and the faulting address might be slightly
708 // different - we still want to unguard the 2nd page in this case.
709 //
710 // 15 bytes seems to be a (very) safe value for max instruction size.
711 bool pc_is_near_addr =
712 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
713 bool instr_spans_page_boundary =
714 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
715 (intptr_t) page_size) > 0);
716
717 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
718 static volatile address last_addr =
719 (address) os::non_memory_address_word();
720
721 // In conservative mode, don't unguard unless the address is in the VM
722 if (addr != last_addr &&
723 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
724
725 // Set memory to RWX and retry
726 address page_start =
727 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
728 bool res = os::protect_memory((char*) page_start, page_size,
729 os::MEM_PROT_RWX);
730
731 if (PrintMiscellaneous && Verbose) {
732 char buf[256];
733 jio_snprintf(buf, sizeof(buf), "Execution protection violation "
734 "at " INTPTR_FORMAT
735 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
736 page_start, (res ? "success" : "failed"), errno);
737 tty->print_raw_cr(buf);
738 }
739 stub = pc;
740
741 // Set last_addr so if we fault again at the same address, we don't end
742 // up in an endless loop.
743 //
744 // There are two potential complications here. Two threads trapping at
745 // the same address at the same time could cause one of the threads to
746 // think it already unguarded, and abort the VM. Likely very rare.
747 //
748 // The other race involves two threads alternately trapping at
749 // different addresses and failing to unguard the page, resulting in
750 // an endless loop. This condition is probably even more unlikely than
751 // the first.
752 //
753 // Although both cases could be avoided by using locks or thread local
754 // last_addr, these solutions are unnecessary complication: this
755 // handler is a best-effort safety net, not a complete solution. It is
756 // disabled by default and should only be used as a workaround in case
757 // we missed any no-execute-unsafe VM code.
758
759 last_addr = addr;
760 }
761 }
762 }
763 #endif // !AMD64
764
765 if (stub != NULL) {
766 // save all thread context in case we need to restore it
767 if (thread != NULL) thread->set_saved_exception_pc(pc);
768
769 uc->context_pc = (intptr_t)stub;
770 return true;
771 }
772
773 // signal-chaining
774 if (os::Bsd::chained_handler(sig, info, ucVoid)) {
775 return true;
776 }
777
778 if (!abort_if_unrecognized) {
779 // caller wants another chance, so give it to him
780 return false;
781 }
782
783 if (pc == NULL && uc != NULL) {
784 pc = os::Bsd::ucontext_get_pc(uc);
785 }
786
787 // unmask current signal
788 sigset_t newset;
789 sigemptyset(&newset);
790 sigaddset(&newset, sig);
791 sigprocmask(SIG_UNBLOCK, &newset, NULL);
792
793 VMError err(t, sig, pc, info, ucVoid);
794 err.report_and_die();
795
796 ShouldNotReachHere();
797 return false;
798 }
799
800 // From solaris_i486.s ported to bsd_i486.s
801 extern "C" void fixcw();
802
803 void os::Bsd::init_thread_fpu_state(void) {
804 #ifndef AMD64
805 // Set fpu to 53 bit precision. This happens too early to use a stub.
806 fixcw();
807 #endif // !AMD64
808 }
809
810
811 // Check that the bsd kernel version is 2.4 or higher since earlier
812 // versions do not support SSE without patches.
813 bool os::supports_sse() {
814 return true;
815 }
816
817 bool os::is_allocatable(size_t bytes) {
818 #ifdef AMD64
819 // unused on amd64?
820 return true;
821 #else
822
823 if (bytes < 2 * G) {
824 return true;
825 }
826
827 char* addr = reserve_memory(bytes, NULL);
828
829 if (addr != NULL) {
830 release_memory(addr, bytes);
831 }
832
833 return addr != NULL;
834 #endif // AMD64
835 }
836
837 ////////////////////////////////////////////////////////////////////////////////
838 // thread stack
839
840 #ifdef AMD64
841 size_t os::Bsd::min_stack_allowed = 64 * K;
842
843 // amd64: pthread on amd64 is always in floating stack mode
844 bool os::Bsd::supports_variable_stack_size() { return true; }
845 #else
846 size_t os::Bsd::min_stack_allowed = (48 DEBUG_ONLY(+4))*K;
847
848 #ifdef __GNUC__
849 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;})
850 #endif
851
852 bool os::Bsd::supports_variable_stack_size() { return true; }
853 #endif // AMD64
854
855 // return default stack size for thr_type
856 size_t os::Bsd::default_stack_size(os::ThreadType thr_type) {
857 // default stack size (compiler thread needs larger stack)
858 #ifdef AMD64
859 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
860 #else
861 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
862 #endif // AMD64
863 return s;
864 }
865
866 size_t os::Bsd::default_guard_size(os::ThreadType thr_type) {
867 // Creating guard page is very expensive. Java thread has HotSpot
868 // guard page, only enable glibc guard page for non-Java threads.
869 return (thr_type == java_thread ? 0 : page_size());
870 }
871
872 // Java thread:
873 //
874 // Low memory addresses
875 // +------------------------+
876 // | |\ JavaThread created by VM does not have glibc
877 // | glibc guard page | - guard, attached Java thread usually has
878 // | |/ 1 page glibc guard.
879 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
880 // | |\
881 // | HotSpot Guard Pages | - red and yellow pages
882 // | |/
883 // +------------------------+ JavaThread::stack_yellow_zone_base()
884 // | |\
885 // | Normal Stack | -
886 // | |/
887 // P2 +------------------------+ Thread::stack_base()
888 //
889 // Non-Java thread:
890 //
891 // Low memory addresses
892 // +------------------------+
893 // | |\
894 // | glibc guard page | - usually 1 page
895 // | |/
896 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
897 // | |\
898 // | Normal Stack | -
899 // | |/
900 // P2 +------------------------+ Thread::stack_base()
901 //
902 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
903 // pthread_attr_getstack()
904
905 static void current_stack_region(address * bottom, size_t * size) {
906 #ifdef __APPLE__
907 pthread_t self = pthread_self();
908 void *stacktop = pthread_get_stackaddr_np(self);
909 *size = pthread_get_stacksize_np(self);
910 // workaround for OS X 10.9.0 (Mavericks)
911 // pthread_get_stacksize_np returns 128 pages even though the actual size is 2048 pages
912 if (::pthread_main_np() == 1) {
913 if ((*size) < (DEFAULT_MAIN_THREAD_STACK_PAGES * (size_t)getpagesize())) {
914 char kern_osrelease[256];
915 size_t kern_osrelease_size = sizeof(kern_osrelease);
916 int ret = sysctlbyname("kern.osrelease", kern_osrelease, &kern_osrelease_size, NULL, 0);
917 if (ret == 0) {
918 // get the major number, atoi will ignore the minor amd micro portions of the version string
919 if (atoi(kern_osrelease) >= OS_X_10_9_0_KERNEL_MAJOR_VERSION) {
920 *size = (DEFAULT_MAIN_THREAD_STACK_PAGES*getpagesize());
921 }
922 }
923 }
924 }
925 *bottom = (address) stacktop - *size;
926 #elif defined(__OpenBSD__)
927 stack_t ss;
928 int rslt = pthread_stackseg_np(pthread_self(), &ss);
929
930 if (rslt != 0)
931 fatal(err_msg("pthread_stackseg_np failed with err = %d", rslt));
932
933 *bottom = (address)((char *)ss.ss_sp - ss.ss_size);
934 *size = ss.ss_size;
935 #else
936 pthread_attr_t attr;
937
938 int rslt = pthread_attr_init(&attr);
939
940 // JVM needs to know exact stack location, abort if it fails
941 if (rslt != 0)
942 fatal(err_msg("pthread_attr_init failed with err = %d", rslt));
943
944 rslt = pthread_attr_get_np(pthread_self(), &attr);
945
946 if (rslt != 0)
947 fatal(err_msg("pthread_attr_get_np failed with err = %d", rslt));
948
949 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 ||
950 pthread_attr_getstacksize(&attr, size) != 0) {
951 fatal("Can not locate current stack attributes!");
952 }
953
954 pthread_attr_destroy(&attr);
955 #endif
956 assert(os::current_stack_pointer() >= *bottom &&
957 os::current_stack_pointer() < *bottom + *size, "just checking");
958 }
959
960 address os::current_stack_base() {
961 address bottom;
962 size_t size;
963 current_stack_region(&bottom, &size);
964 return (bottom + size);
965 }
966
967 size_t os::current_stack_size() {
968 // stack size includes normal stack and HotSpot guard pages
969 address bottom;
970 size_t size;
971 current_stack_region(&bottom, &size);
972 return size;
973 }
974
975 /////////////////////////////////////////////////////////////////////////////
976 // helper functions for fatal error handler
977
978 void os::print_context(outputStream *st, void *context) {
979 if (context == NULL) return;
980
981 ucontext_t *uc = (ucontext_t*)context;
982 st->print_cr("Registers:");
983 #ifdef AMD64
984 st->print( "RAX=" INTPTR_FORMAT, uc->context_rax);
985 st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx);
986 st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx);
987 st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx);
988 st->cr();
989 st->print( "RSP=" INTPTR_FORMAT, uc->context_rsp);
990 st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp);
991 st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi);
992 st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi);
993 st->cr();
994 st->print( "R8 =" INTPTR_FORMAT, uc->context_r8);
995 st->print(", R9 =" INTPTR_FORMAT, uc->context_r9);
996 st->print(", R10=" INTPTR_FORMAT, uc->context_r10);
997 st->print(", R11=" INTPTR_FORMAT, uc->context_r11);
998 st->cr();
999 st->print( "R12=" INTPTR_FORMAT, uc->context_r12);
1000 st->print(", R13=" INTPTR_FORMAT, uc->context_r13);
1001 st->print(", R14=" INTPTR_FORMAT, uc->context_r14);
1002 st->print(", R15=" INTPTR_FORMAT, uc->context_r15);
1003 st->cr();
1004 st->print( "RIP=" INTPTR_FORMAT, uc->context_rip);
1005 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags);
1006 st->print(", ERR=" INTPTR_FORMAT, uc->context_err);
1007 st->cr();
1008 st->print(" TRAPNO=" INTPTR_FORMAT, uc->context_trapno);
1009 #else
1010 st->print( "EAX=" INTPTR_FORMAT, uc->context_eax);
1011 st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx);
1012 st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx);
1013 st->print(", EDX=" INTPTR_FORMAT, uc->context_edx);
1014 st->cr();
1015 st->print( "ESP=" INTPTR_FORMAT, uc->context_esp);
1016 st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp);
1017 st->print(", ESI=" INTPTR_FORMAT, uc->context_esi);
1018 st->print(", EDI=" INTPTR_FORMAT, uc->context_edi);
1019 st->cr();
1020 st->print( "EIP=" INTPTR_FORMAT, uc->context_eip);
1021 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags);
1022 #endif // AMD64
1023 st->cr();
1024 st->cr();
1025
1026 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc);
1027 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
1028 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
1029 st->cr();
1030
1031 // Note: it may be unsafe to inspect memory near pc. For example, pc may
1032 // point to garbage if entry point in an nmethod is corrupted. Leave
1033 // this at the end, and hope for the best.
1034 address pc = os::Bsd::ucontext_get_pc(uc);
1035 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
1036 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
1037 }
1038
1039 void os::print_register_info(outputStream *st, void *context) {
1040 if (context == NULL) return;
1041
1042 ucontext_t *uc = (ucontext_t*)context;
1043
1044 st->print_cr("Register to memory mapping:");
1045 st->cr();
1046
1047 // this is horrendously verbose but the layout of the registers in the
1048 // context does not match how we defined our abstract Register set, so
1049 // we can't just iterate through the gregs area
1050
1051 // this is only for the "general purpose" registers
1052
1053 #ifdef AMD64
1054 st->print("RAX="); print_location(st, uc->context_rax);
1055 st->print("RBX="); print_location(st, uc->context_rbx);
1056 st->print("RCX="); print_location(st, uc->context_rcx);
1057 st->print("RDX="); print_location(st, uc->context_rdx);
1058 st->print("RSP="); print_location(st, uc->context_rsp);
1059 st->print("RBP="); print_location(st, uc->context_rbp);
1060 st->print("RSI="); print_location(st, uc->context_rsi);
1061 st->print("RDI="); print_location(st, uc->context_rdi);
1062 st->print("R8 ="); print_location(st, uc->context_r8);
1063 st->print("R9 ="); print_location(st, uc->context_r9);
1064 st->print("R10="); print_location(st, uc->context_r10);
1065 st->print("R11="); print_location(st, uc->context_r11);
1066 st->print("R12="); print_location(st, uc->context_r12);
1067 st->print("R13="); print_location(st, uc->context_r13);
1068 st->print("R14="); print_location(st, uc->context_r14);
1069 st->print("R15="); print_location(st, uc->context_r15);
1070 #else
1071 st->print("EAX="); print_location(st, uc->context_eax);
1072 st->print("EBX="); print_location(st, uc->context_ebx);
1073 st->print("ECX="); print_location(st, uc->context_ecx);
1074 st->print("EDX="); print_location(st, uc->context_edx);
1075 st->print("ESP="); print_location(st, uc->context_esp);
1076 st->print("EBP="); print_location(st, uc->context_ebp);
1077 st->print("ESI="); print_location(st, uc->context_esi);
1078 st->print("EDI="); print_location(st, uc->context_edi);
1079 #endif // AMD64
1080
1081 st->cr();
1082 }
1083
1084 void os::setup_fpu() {
1085 #ifndef AMD64
1086 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
1087 __asm__ volatile ( "fldcw (%0)" :
1088 : "r" (fpu_cntrl) : "memory");
1089 #endif // !AMD64
1090 }
1091
1092 #ifndef PRODUCT
1093 void os::verify_stack_alignment() {
1094 }
1095 #endif
1096