1 /*
2 * Copyright (c) 1999, 2019, 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 "jvm.h"
27 #include "asm/macroAssembler.hpp"
28 #include "classfile/classLoader.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "code/codeCache.hpp"
32 #include "code/icBuffer.hpp"
33 #include "code/vtableStubs.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "logging/log.hpp"
36 #include "memory/allocation.inline.hpp"
37 #include "os_share_bsd.hpp"
38 #include "prims/jniFastGetField.hpp"
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.inline.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/align.hpp"
53 #include "utilities/events.hpp"
54 #include "utilities/vmError.hpp"
55
56 // put OS-includes here
57 # include <sys/types.h>
58 # include <sys/mman.h>
59 # include <pthread.h>
60 # include <signal.h>
61 # include <errno.h>
62 # include <dlfcn.h>
63 # include <stdlib.h>
64 # include <stdio.h>
65 # include <unistd.h>
66 # include <sys/resource.h>
67 # include <pthread.h>
68 # include <sys/stat.h>
69 # include <sys/time.h>
70 # include <sys/utsname.h>
71 # include <sys/socket.h>
72 # include <sys/wait.h>
73 # include <pwd.h>
74 # include <poll.h>
75 #ifndef __OpenBSD__
76 # include <ucontext.h>
77 #endif
78
79 #if !defined(__APPLE__) && !defined(__NetBSD__)
80 # include <pthread_np.h>
81 #endif
82
83 // needed by current_stack_region() workaround for Mavericks
84 #if defined(__APPLE__)
85 # include <errno.h>
86 # include <sys/types.h>
87 # include <sys/sysctl.h>
88 # define DEFAULT_MAIN_THREAD_STACK_PAGES 2048
89 # define OS_X_10_9_0_KERNEL_MAJOR_VERSION 13
90 #endif
91
92 #ifdef AMD64
93 #define SPELL_REG_SP "rsp"
94 #define SPELL_REG_FP "rbp"
95 #else
96 #define SPELL_REG_SP "esp"
97 #define SPELL_REG_FP "ebp"
98 #endif // AMD64
99
100 #ifdef __FreeBSD__
101 # define context_trapno uc_mcontext.mc_trapno
102 # ifdef AMD64
103 # define context_pc uc_mcontext.mc_rip
104 # define context_sp uc_mcontext.mc_rsp
105 # define context_fp uc_mcontext.mc_rbp
106 # define context_rip uc_mcontext.mc_rip
107 # define context_rsp uc_mcontext.mc_rsp
108 # define context_rbp uc_mcontext.mc_rbp
109 # define context_rax uc_mcontext.mc_rax
110 # define context_rbx uc_mcontext.mc_rbx
111 # define context_rcx uc_mcontext.mc_rcx
112 # define context_rdx uc_mcontext.mc_rdx
113 # define context_rsi uc_mcontext.mc_rsi
114 # define context_rdi uc_mcontext.mc_rdi
115 # define context_r8 uc_mcontext.mc_r8
116 # define context_r9 uc_mcontext.mc_r9
117 # define context_r10 uc_mcontext.mc_r10
118 # define context_r11 uc_mcontext.mc_r11
119 # define context_r12 uc_mcontext.mc_r12
120 # define context_r13 uc_mcontext.mc_r13
121 # define context_r14 uc_mcontext.mc_r14
122 # define context_r15 uc_mcontext.mc_r15
123 # define context_flags uc_mcontext.mc_flags
124 # define context_err uc_mcontext.mc_err
125 # else
126 # define context_pc uc_mcontext.mc_eip
127 # define context_sp uc_mcontext.mc_esp
128 # define context_fp uc_mcontext.mc_ebp
129 # define context_eip uc_mcontext.mc_eip
130 # define context_esp uc_mcontext.mc_esp
131 # define context_eax uc_mcontext.mc_eax
132 # define context_ebx uc_mcontext.mc_ebx
133 # define context_ecx uc_mcontext.mc_ecx
134 # define context_edx uc_mcontext.mc_edx
135 # define context_ebp uc_mcontext.mc_ebp
136 # define context_esi uc_mcontext.mc_esi
137 # define context_edi uc_mcontext.mc_edi
138 # define context_eflags uc_mcontext.mc_eflags
139 # define context_trapno uc_mcontext.mc_trapno
140 # endif
141 #endif
142
143 #ifdef __APPLE__
144 # if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
145 // 10.5 UNIX03 member name prefixes
146 #define DU3_PREFIX(s, m) __ ## s.__ ## m
147 # else
148 #define DU3_PREFIX(s, m) s ## . ## m
149 # endif
150
151 # ifdef AMD64
152 # define context_pc context_rip
153 # define context_sp context_rsp
154 # define context_fp context_rbp
155 # define context_rip uc_mcontext->DU3_PREFIX(ss,rip)
156 # define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp)
157 # define context_rax uc_mcontext->DU3_PREFIX(ss,rax)
158 # define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx)
159 # define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx)
160 # define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx)
161 # define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp)
162 # define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi)
163 # define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi)
164 # define context_r8 uc_mcontext->DU3_PREFIX(ss,r8)
165 # define context_r9 uc_mcontext->DU3_PREFIX(ss,r9)
166 # define context_r10 uc_mcontext->DU3_PREFIX(ss,r10)
167 # define context_r11 uc_mcontext->DU3_PREFIX(ss,r11)
168 # define context_r12 uc_mcontext->DU3_PREFIX(ss,r12)
169 # define context_r13 uc_mcontext->DU3_PREFIX(ss,r13)
170 # define context_r14 uc_mcontext->DU3_PREFIX(ss,r14)
171 # define context_r15 uc_mcontext->DU3_PREFIX(ss,r15)
172 # define context_flags uc_mcontext->DU3_PREFIX(ss,rflags)
173 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno)
174 # define context_err uc_mcontext->DU3_PREFIX(es,err)
175 # else
176 # define context_pc context_eip
177 # define context_sp context_esp
178 # define context_fp context_ebp
179 # define context_eip uc_mcontext->DU3_PREFIX(ss,eip)
180 # define context_esp uc_mcontext->DU3_PREFIX(ss,esp)
181 # define context_eax uc_mcontext->DU3_PREFIX(ss,eax)
182 # define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx)
183 # define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx)
184 # define context_edx uc_mcontext->DU3_PREFIX(ss,edx)
185 # define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp)
186 # define context_esi uc_mcontext->DU3_PREFIX(ss,esi)
187 # define context_edi uc_mcontext->DU3_PREFIX(ss,edi)
188 # define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags)
189 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno)
190 # endif
191 #endif
192
193 #ifdef __OpenBSD__
194 # define context_trapno sc_trapno
195 # ifdef AMD64
196 # define context_pc sc_rip
197 # define context_sp sc_rsp
198 # define context_fp sc_rbp
199 # define context_rip sc_rip
200 # define context_rsp sc_rsp
201 # define context_rbp sc_rbp
202 # define context_rax sc_rax
203 # define context_rbx sc_rbx
204 # define context_rcx sc_rcx
205 # define context_rdx sc_rdx
206 # define context_rsi sc_rsi
207 # define context_rdi sc_rdi
208 # define context_r8 sc_r8
209 # define context_r9 sc_r9
210 # define context_r10 sc_r10
211 # define context_r11 sc_r11
212 # define context_r12 sc_r12
213 # define context_r13 sc_r13
214 # define context_r14 sc_r14
215 # define context_r15 sc_r15
216 # define context_flags sc_rflags
217 # define context_err sc_err
218 # else
219 # define context_pc sc_eip
220 # define context_sp sc_esp
221 # define context_fp sc_ebp
222 # define context_eip sc_eip
223 # define context_esp sc_esp
224 # define context_eax sc_eax
225 # define context_ebx sc_ebx
226 # define context_ecx sc_ecx
227 # define context_edx sc_edx
228 # define context_ebp sc_ebp
229 # define context_esi sc_esi
230 # define context_edi sc_edi
231 # define context_eflags sc_eflags
232 # define context_trapno sc_trapno
233 # endif
234 #endif
235
236 #ifdef __NetBSD__
237 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO]
238 # ifdef AMD64
239 # define __register_t __greg_t
240 # define context_pc uc_mcontext.__gregs[_REG_RIP]
241 # define context_sp uc_mcontext.__gregs[_REG_URSP]
242 # define context_fp uc_mcontext.__gregs[_REG_RBP]
243 # define context_rip uc_mcontext.__gregs[_REG_RIP]
244 # define context_rsp uc_mcontext.__gregs[_REG_URSP]
245 # define context_rax uc_mcontext.__gregs[_REG_RAX]
246 # define context_rbx uc_mcontext.__gregs[_REG_RBX]
247 # define context_rcx uc_mcontext.__gregs[_REG_RCX]
248 # define context_rdx uc_mcontext.__gregs[_REG_RDX]
249 # define context_rbp uc_mcontext.__gregs[_REG_RBP]
250 # define context_rsi uc_mcontext.__gregs[_REG_RSI]
251 # define context_rdi uc_mcontext.__gregs[_REG_RDI]
252 # define context_r8 uc_mcontext.__gregs[_REG_R8]
253 # define context_r9 uc_mcontext.__gregs[_REG_R9]
254 # define context_r10 uc_mcontext.__gregs[_REG_R10]
255 # define context_r11 uc_mcontext.__gregs[_REG_R11]
256 # define context_r12 uc_mcontext.__gregs[_REG_R12]
257 # define context_r13 uc_mcontext.__gregs[_REG_R13]
258 # define context_r14 uc_mcontext.__gregs[_REG_R14]
259 # define context_r15 uc_mcontext.__gregs[_REG_R15]
260 # define context_flags uc_mcontext.__gregs[_REG_RFL]
261 # define context_err uc_mcontext.__gregs[_REG_ERR]
262 # else
263 # define context_pc uc_mcontext.__gregs[_REG_EIP]
264 # define context_sp uc_mcontext.__gregs[_REG_UESP]
265 # define context_fp uc_mcontext.__gregs[_REG_EBP]
266 # define context_eip uc_mcontext.__gregs[_REG_EIP]
267 # define context_esp uc_mcontext.__gregs[_REG_UESP]
268 # define context_eax uc_mcontext.__gregs[_REG_EAX]
269 # define context_ebx uc_mcontext.__gregs[_REG_EBX]
270 # define context_ecx uc_mcontext.__gregs[_REG_ECX]
271 # define context_edx uc_mcontext.__gregs[_REG_EDX]
272 # define context_ebp uc_mcontext.__gregs[_REG_EBP]
273 # define context_esi uc_mcontext.__gregs[_REG_ESI]
274 # define context_edi uc_mcontext.__gregs[_REG_EDI]
275 # define context_eflags uc_mcontext.__gregs[_REG_EFL]
276 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO]
277 # endif
278 #endif
279
280 address os::current_stack_pointer() {
281 #if defined(__clang__) || defined(__llvm__)
282 void *esp;
283 __asm__("mov %%" SPELL_REG_SP ", %0":"=r"(esp));
284 return (address) esp;
285 #elif defined(SPARC_WORKS)
286 void *esp;
287 __asm__("mov %%" SPELL_REG_SP ", %0":"=r"(esp));
288 return (address) ((char*)esp + sizeof(long)*2);
289 #else
290 register void *esp __asm__ (SPELL_REG_SP);
291 return (address) esp;
292 #endif
293 }
294
295 char* os::non_memory_address_word() {
296 // Must never look like an address returned by reserve_memory,
297 // even in its subfields (as defined by the CPU immediate fields,
298 // if the CPU splits constants across multiple instructions).
299
300 return (char*) -1;
301 }
302
303 address os::Bsd::ucontext_get_pc(const ucontext_t * uc) {
304 return (address)uc->context_pc;
305 }
306
307 void os::Bsd::ucontext_set_pc(ucontext_t * uc, address pc) {
308 uc->context_pc = (intptr_t)pc ;
309 }
310
311 intptr_t* os::Bsd::ucontext_get_sp(const ucontext_t * uc) {
312 return (intptr_t*)uc->context_sp;
313 }
314
315 intptr_t* os::Bsd::ucontext_get_fp(const ucontext_t * uc) {
316 return (intptr_t*)uc->context_fp;
317 }
318
319 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
320 // is currently interrupted by SIGPROF.
321 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
322 // frames. Currently we don't do that on Bsd, so it's the same as
323 // os::fetch_frame_from_context().
324 // This method is also used for stack overflow signal handling.
325 ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread,
326 const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
327
328 assert(thread != NULL, "just checking");
329 assert(ret_sp != NULL, "just checking");
330 assert(ret_fp != NULL, "just checking");
331
332 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
333 }
334
335 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
336 intptr_t** ret_sp, intptr_t** ret_fp) {
337
338 ExtendedPC epc;
339 const ucontext_t* uc = (const ucontext_t*)ucVoid;
340
341 if (uc != NULL) {
342 epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc));
343 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc);
344 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc);
345 } else {
346 // construct empty ExtendedPC for return value checking
347 epc = ExtendedPC(NULL);
348 if (ret_sp) *ret_sp = (intptr_t *)NULL;
349 if (ret_fp) *ret_fp = (intptr_t *)NULL;
350 }
351
352 return epc;
353 }
354
355 frame os::fetch_frame_from_context(const void* ucVoid) {
356 intptr_t* sp;
357 intptr_t* fp;
358 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
359 return frame(sp, fp, epc.pc());
360 }
361
362 frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) {
363 intptr_t* sp;
364 intptr_t* fp;
365 ExtendedPC epc = os::Bsd::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp);
366 return frame(sp, fp, epc.pc());
367 }
368
369 bool os::Bsd::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
370 address pc = (address) os::Bsd::ucontext_get_pc(uc);
371 if (Interpreter::contains(pc)) {
372 // interpreter performs stack banging after the fixed frame header has
373 // been generated while the compilers perform it before. To maintain
374 // semantic consistency between interpreted and compiled frames, the
375 // method returns the Java sender of the current frame.
376 *fr = os::fetch_frame_from_ucontext(thread, uc);
377 if (!fr->is_first_java_frame()) {
378 // get_frame_at_stack_banging_point() is only called when we
379 // have well defined stacks so java_sender() calls do not need
380 // to assert safe_for_sender() first.
381 *fr = fr->java_sender();
382 }
383 } else {
384 // more complex code with compiled code
385 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
386 CodeBlob* cb = CodeCache::find_blob(pc);
387 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
388 // Not sure where the pc points to, fallback to default
389 // stack overflow handling
390 return false;
391 } else {
392 *fr = os::fetch_frame_from_ucontext(thread, uc);
393 // in compiled code, the stack banging is performed just after the return pc
394 // has been pushed on the stack
395 *fr = frame(fr->sp() + 1, fr->fp(), (address)*(fr->sp()));
396 if (!fr->is_java_frame()) {
397 // See java_sender() comment above.
398 *fr = fr->java_sender();
399 }
400 }
401 }
402 assert(fr->is_java_frame(), "Safety check");
403 return true;
404 }
405
406 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get
407 // turned off by -fomit-frame-pointer,
408 frame os::get_sender_for_C_frame(frame* fr) {
409 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
410 }
411
412 intptr_t* _get_previous_fp() {
413 #if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__)
414 intptr_t **ebp;
415 __asm__("mov %%" SPELL_REG_FP ", %0":"=r"(ebp));
416 #else
417 register intptr_t **ebp __asm__ (SPELL_REG_FP);
418 #endif
419 // ebp is for this frame (_get_previous_fp). We want the ebp for the
420 // caller of os::current_frame*(), so go up two frames. However, for
421 // optimized builds, _get_previous_fp() will be inlined, so only go
422 // up 1 frame in that case.
423 #ifdef _NMT_NOINLINE_
424 return **(intptr_t***)ebp;
425 #else
426 return *ebp;
427 #endif
428 }
429
430
431 frame os::current_frame() {
432 intptr_t* fp = _get_previous_fp();
433 frame myframe((intptr_t*)os::current_stack_pointer(),
434 (intptr_t*)fp,
435 CAST_FROM_FN_PTR(address, os::current_frame));
436 if (os::is_first_C_frame(&myframe)) {
437 // stack is not walkable
438 return frame();
439 } else {
440 return os::get_sender_for_C_frame(&myframe);
441 }
442 }
443
444 // Utility functions
445
446 // From IA32 System Programming Guide
447 enum {
448 trap_page_fault = 0xE
449 };
450
451 extern "C" JNIEXPORT int
452 JVM_handle_bsd_signal(int sig,
453 siginfo_t* info,
454 void* ucVoid,
455 int abort_if_unrecognized) {
456 ucontext_t* uc = (ucontext_t*) ucVoid;
457
458 Thread* t = Thread::current_or_null_safe();
459
460 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
461 // (no destructors can be run)
462 os::ThreadCrashProtection::check_crash_protection(sig, t);
463
464 SignalHandlerMark shm(t);
465
466 // Note: it's not uncommon that JNI code uses signal/sigset to install
467 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
468 // or have a SIGILL handler when detecting CPU type). When that happens,
469 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To
470 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
471 // that do not require siginfo/ucontext first.
472
473 if (sig == SIGPIPE || sig == SIGXFSZ) {
474 // allow chained handler to go first
475 if (os::Bsd::chained_handler(sig, info, ucVoid)) {
476 return true;
477 } else {
478 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
479 return true;
480 }
481 }
482
483 JavaThread* thread = NULL;
484 VMThread* vmthread = NULL;
485 if (os::Bsd::signal_handlers_are_installed) {
486 if (t != NULL ){
487 if(t->is_Java_thread()) {
488 thread = (JavaThread*)t;
489 }
490 else if(t->is_VM_thread()){
491 vmthread = (VMThread *)t;
492 }
493 }
494 }
495 /*
496 NOTE: does not seem to work on bsd.
497 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
498 // can't decode this kind of signal
499 info = NULL;
500 } else {
501 assert(sig == info->si_signo, "bad siginfo");
502 }
503 */
504 // decide if this trap can be handled by a stub
505 address stub = NULL;
506
507 address pc = NULL;
508
509 //%note os_trap_1
510 if (info != NULL && uc != NULL && thread != NULL) {
511 pc = (address) os::Bsd::ucontext_get_pc(uc);
512
513 if (StubRoutines::is_safefetch_fault(pc)) {
514 os::Bsd::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
515 return 1;
516 }
517
518 // Handle ALL stack overflow variations here
519 if (sig == SIGSEGV || sig == SIGBUS) {
520 address addr = (address) info->si_addr;
521
522 // check if fault address is within thread stack
523 if (thread->on_local_stack(addr)) {
524 // stack overflow
525 if (thread->in_stack_yellow_reserved_zone(addr)) {
526 if (thread->thread_state() == _thread_in_Java) {
527 if (thread->in_stack_reserved_zone(addr)) {
528 frame fr;
529 if (os::Bsd::get_frame_at_stack_banging_point(thread, uc, &fr)) {
530 assert(fr.is_java_frame(), "Must be a Java frame");
531 frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
532 if (activation.sp() != NULL) {
533 thread->disable_stack_reserved_zone();
534 if (activation.is_interpreted_frame()) {
535 thread->set_reserved_stack_activation((address)(
536 activation.fp() + frame::interpreter_frame_initial_sp_offset));
537 } else {
538 thread->set_reserved_stack_activation((address)activation.unextended_sp());
539 }
540 return 1;
541 }
542 }
543 }
544 // Throw a stack overflow exception. Guard pages will be reenabled
545 // while unwinding the stack.
546 thread->disable_stack_yellow_reserved_zone();
547 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
548 } else {
549 // Thread was in the vm or native code. Return and try to finish.
550 thread->disable_stack_yellow_reserved_zone();
551 return 1;
552 }
553 } else if (thread->in_stack_red_zone(addr)) {
554 // Fatal red zone violation. Disable the guard pages and fall through
555 // to handle_unexpected_exception way down below.
556 thread->disable_stack_red_zone();
557 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
558 }
559 }
560 }
561
562 if ((sig == SIGSEGV || sig == SIGBUS) && VM_Version::is_cpuinfo_segv_addr(pc)) {
563 // Verify that OS save/restore AVX registers.
564 stub = VM_Version::cpuinfo_cont_addr();
565 }
566
567 // We test if stub is already set (by the stack overflow code
568 // above) so it is not overwritten by the code that follows. This
569 // check is not required on other platforms, because on other
570 // platforms we check for SIGSEGV only or SIGBUS only, where here
571 // we have to check for both SIGSEGV and SIGBUS.
572 if (thread->thread_state() == _thread_in_Java && stub == NULL) {
573 // Java thread running in Java code => find exception handler if any
574 // a fault inside compiled code, the interpreter, or a stub
575
576 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) {
577 stub = SharedRuntime::get_poll_stub(pc);
578 #if defined(__APPLE__)
579 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions.
580 // 64-bit Darwin may also use a SIGBUS (seen with compressed oops).
581 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from
582 // being called, so only do so if the implicit NULL check is not necessary.
583 } else if (sig == SIGBUS && !MacroAssembler::uses_implicit_null_check(info->si_addr)) {
584 #else
585 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
586 #endif
587 // BugId 4454115: A read from a MappedByteBuffer can fault
588 // here if the underlying file has been truncated.
589 // Do not crash the VM in such a case.
590 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
591 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
592 bool is_unsafe_arraycopy = thread->doing_unsafe_access() && UnsafeCopyMemory::contains_pc(pc);
593 if ((nm != NULL && nm->has_unsafe_access()) || is_unsafe_arraycopy) {
594 address next_pc = Assembler::locate_next_instruction(pc);
595 if (is_unsafe_arraycopy) {
596 next_pc = UnsafeCopyMemory::page_error_continue_pc(pc);
597 }
598 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
599 }
600 }
601 else
602
603 #ifdef AMD64
604 if (sig == SIGFPE &&
605 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
606 stub =
607 SharedRuntime::
608 continuation_for_implicit_exception(thread,
609 pc,
610 SharedRuntime::
611 IMPLICIT_DIVIDE_BY_ZERO);
612 #ifdef __APPLE__
613 } else if (sig == SIGFPE && info->si_code == FPE_NOOP) {
614 int op = pc[0];
615
616 // Skip REX
617 if ((pc[0] & 0xf0) == 0x40) {
618 op = pc[1];
619 } else {
620 op = pc[0];
621 }
622
623 // Check for IDIV
624 if (op == 0xF7) {
625 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO);
626 } else {
627 // TODO: handle more cases if we are using other x86 instructions
628 // that can generate SIGFPE signal.
629 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
630 fatal("please update this code.");
631 }
632 #endif /* __APPLE__ */
633
634 #else
635 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) {
636 // HACK: si_code does not work on bsd 2.2.12-20!!!
637 int op = pc[0];
638 if (op == 0xDB) {
639 // FIST
640 // TODO: The encoding of D2I in i486.ad can cause an exception
641 // prior to the fist instruction if there was an invalid operation
642 // pending. We want to dismiss that exception. From the win_32
643 // side it also seems that if it really was the fist causing
644 // the exception that we do the d2i by hand with different
645 // rounding. Seems kind of weird.
646 // NOTE: that we take the exception at the NEXT floating point instruction.
647 assert(pc[0] == 0xDB, "not a FIST opcode");
648 assert(pc[1] == 0x14, "not a FIST opcode");
649 assert(pc[2] == 0x24, "not a FIST opcode");
650 return true;
651 } else if (op == 0xF7) {
652 // IDIV
653 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
654 } else {
655 // TODO: handle more cases if we are using other x86 instructions
656 // that can generate SIGFPE signal on bsd.
657 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
658 fatal("please update this code.");
659 }
660 #endif // AMD64
661 } else if ((sig == SIGSEGV || sig == SIGBUS) &&
662 MacroAssembler::uses_implicit_null_check(info->si_addr)) {
663 // Determination of interpreter/vtable stub/compiled code null exception
664 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
665 }
666 } else if ((thread->thread_state() == _thread_in_vm ||
667 thread->thread_state() == _thread_in_native) &&
668 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
669 thread->doing_unsafe_access()) {
670 address next_pc = Assembler::locate_next_instruction(pc);
671 if (UnsafeCopyMemory::contains_pc(pc)) {
672 next_pc = UnsafeCopyMemory::page_error_continue_pc(pc);
673 }
674 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
675 }
676
677 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
678 // and the heap gets shrunk before the field access.
679 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
680 address addr = JNI_FastGetField::find_slowcase_pc(pc);
681 if (addr != (address)-1) {
682 stub = addr;
683 }
684 }
685 }
686
687 #ifndef AMD64
688 // Execution protection violation
689 //
690 // This should be kept as the last step in the triage. We don't
691 // have a dedicated trap number for a no-execute fault, so be
692 // conservative and allow other handlers the first shot.
693 //
694 // Note: We don't test that info->si_code == SEGV_ACCERR here.
695 // this si_code is so generic that it is almost meaningless; and
696 // the si_code for this condition may change in the future.
697 // Furthermore, a false-positive should be harmless.
698 if (UnguardOnExecutionViolation > 0 &&
699 (sig == SIGSEGV || sig == SIGBUS) &&
700 uc->context_trapno == trap_page_fault) {
701 int page_size = os::vm_page_size();
702 address addr = (address) info->si_addr;
703 address pc = os::Bsd::ucontext_get_pc(uc);
704 // Make sure the pc and the faulting address are sane.
705 //
706 // If an instruction spans a page boundary, and the page containing
707 // the beginning of the instruction is executable but the following
708 // page is not, the pc and the faulting address might be slightly
709 // different - we still want to unguard the 2nd page in this case.
710 //
711 // 15 bytes seems to be a (very) safe value for max instruction size.
712 bool pc_is_near_addr =
713 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
714 bool instr_spans_page_boundary =
715 (align_down((intptr_t) pc ^ (intptr_t) addr,
716 (intptr_t) page_size) > 0);
717
718 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
719 static volatile address last_addr =
720 (address) os::non_memory_address_word();
721
722 // In conservative mode, don't unguard unless the address is in the VM
723 if (addr != last_addr &&
724 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
725
726 // Set memory to RWX and retry
727 address page_start = align_down(addr, page_size);
728 bool res = os::protect_memory((char*) page_start, page_size,
729 os::MEM_PROT_RWX);
730
731 log_debug(os)("Execution protection violation "
732 "at " INTPTR_FORMAT
733 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", p2i(addr),
734 p2i(page_start), (res ? "success" : "failed"), errno);
735 stub = pc;
736
737 // Set last_addr so if we fault again at the same address, we don't end
738 // up in an endless loop.
739 //
740 // There are two potential complications here. Two threads trapping at
741 // the same address at the same time could cause one of the threads to
742 // think it already unguarded, and abort the VM. Likely very rare.
743 //
744 // The other race involves two threads alternately trapping at
745 // different addresses and failing to unguard the page, resulting in
746 // an endless loop. This condition is probably even more unlikely than
747 // the first.
748 //
749 // Although both cases could be avoided by using locks or thread local
750 // last_addr, these solutions are unnecessary complication: this
751 // handler is a best-effort safety net, not a complete solution. It is
752 // disabled by default and should only be used as a workaround in case
753 // we missed any no-execute-unsafe VM code.
754
755 last_addr = addr;
756 }
757 }
758 }
759 #endif // !AMD64
760
761 if (stub != NULL) {
762 // save all thread context in case we need to restore it
763 if (thread != NULL) thread->set_saved_exception_pc(pc);
764
765 os::Bsd::ucontext_set_pc(uc, stub);
766 return true;
767 }
768
769 // signal-chaining
770 if (os::Bsd::chained_handler(sig, info, ucVoid)) {
771 return true;
772 }
773
774 if (!abort_if_unrecognized) {
775 // caller wants another chance, so give it to him
776 return false;
777 }
778
779 if (pc == NULL && uc != NULL) {
780 pc = os::Bsd::ucontext_get_pc(uc);
781 }
782
783 // unmask current signal
784 sigset_t newset;
785 sigemptyset(&newset);
786 sigaddset(&newset, sig);
787 sigprocmask(SIG_UNBLOCK, &newset, NULL);
788
789 VMError::report_and_die(t, sig, pc, info, ucVoid);
790
791 ShouldNotReachHere();
792 return false;
793 }
794
795 // From solaris_i486.s ported to bsd_i486.s
796 extern "C" void fixcw();
797
798 void os::Bsd::init_thread_fpu_state(void) {
799 #ifndef AMD64
800 // Set fpu to 53 bit precision. This happens too early to use a stub.
801 fixcw();
802 #endif // !AMD64
803 }
804
805
806 // Check that the bsd kernel version is 2.4 or higher since earlier
807 // versions do not support SSE without patches.
808 bool os::supports_sse() {
809 return true;
810 }
811
812 bool os::is_allocatable(size_t bytes) {
813 #ifdef AMD64
814 // unused on amd64?
815 return true;
816 #else
817
818 if (bytes < 2 * G) {
819 return true;
820 }
821
822 char* addr = reserve_memory(bytes, NULL);
823
824 if (addr != NULL) {
825 release_memory(addr, bytes);
826 }
827
828 return addr != NULL;
829 #endif // AMD64
830 }
831
832 ////////////////////////////////////////////////////////////////////////////////
833 // thread stack
834
835 // Minimum usable stack sizes required to get to user code. Space for
836 // HotSpot guard pages is added later.
837 size_t os::Posix::_compiler_thread_min_stack_allowed = 48 * K;
838 size_t os::Posix::_java_thread_min_stack_allowed = 48 * K;
839 #ifdef _LP64
840 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K;
841 #else
842 size_t os::Posix::_vm_internal_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K;
843 #endif // _LP64
844
845 #ifndef AMD64
846 #ifdef __GNUC__
847 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;})
848 #endif
849 #endif // AMD64
850
851 // return default stack size for thr_type
852 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
853 // default stack size (compiler thread needs larger stack)
854 #ifdef AMD64
855 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
856 #else
857 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
858 #endif // AMD64
859 return s;
860 }
861
862
863 // Java thread:
864 //
865 // Low memory addresses
866 // +------------------------+
867 // | |\ Java thread created by VM does not have glibc
868 // | glibc guard page | - guard, attached Java thread usually has
869 // | |/ 1 glibc guard page.
870 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
871 // | |\
872 // | HotSpot Guard Pages | - red, yellow and reserved pages
873 // | |/
874 // +------------------------+ JavaThread::stack_reserved_zone_base()
875 // | |\
876 // | Normal Stack | -
877 // | |/
878 // P2 +------------------------+ Thread::stack_base()
879 //
880 // Non-Java thread:
881 //
882 // Low memory addresses
883 // +------------------------+
884 // | |\
885 // | glibc guard page | - usually 1 page
886 // | |/
887 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
888 // | |\
889 // | Normal Stack | -
890 // | |/
891 // P2 +------------------------+ Thread::stack_base()
892 //
893 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
894 // pthread_attr_getstack()
895
896 static void current_stack_region(address * bottom, size_t * size) {
897 #ifdef __APPLE__
898 pthread_t self = pthread_self();
899 void *stacktop = pthread_get_stackaddr_np(self);
900 *size = pthread_get_stacksize_np(self);
901 // workaround for OS X 10.9.0 (Mavericks)
902 // pthread_get_stacksize_np returns 128 pages even though the actual size is 2048 pages
903 if (pthread_main_np() == 1) {
904 // At least on Mac OS 10.12 we have observed stack sizes not aligned
905 // to pages boundaries. This can be provoked by e.g. setrlimit() (ulimit -s xxxx in the
906 // shell). Apparently Mac OS actually rounds upwards to next multiple of page size,
907 // however, we round downwards here to be on the safe side.
908 *size = align_down(*size, getpagesize());
909
910 if ((*size) < (DEFAULT_MAIN_THREAD_STACK_PAGES * (size_t)getpagesize())) {
911 char kern_osrelease[256];
912 size_t kern_osrelease_size = sizeof(kern_osrelease);
913 int ret = sysctlbyname("kern.osrelease", kern_osrelease, &kern_osrelease_size, NULL, 0);
914 if (ret == 0) {
915 // get the major number, atoi will ignore the minor amd micro portions of the version string
916 if (atoi(kern_osrelease) >= OS_X_10_9_0_KERNEL_MAJOR_VERSION) {
917 *size = (DEFAULT_MAIN_THREAD_STACK_PAGES*getpagesize());
918 }
919 }
920 }
921 }
922 *bottom = (address) stacktop - *size;
923 #elif defined(__OpenBSD__)
924 stack_t ss;
925 int rslt = pthread_stackseg_np(pthread_self(), &ss);
926
927 if (rslt != 0)
928 fatal("pthread_stackseg_np failed with error = %d", rslt);
929
930 *bottom = (address)((char *)ss.ss_sp - ss.ss_size);
931 *size = ss.ss_size;
932 #else
933 pthread_attr_t attr;
934
935 int rslt = pthread_attr_init(&attr);
936
937 // JVM needs to know exact stack location, abort if it fails
938 if (rslt != 0)
939 fatal("pthread_attr_init failed with error = %d", rslt);
940
941 rslt = pthread_attr_get_np(pthread_self(), &attr);
942
943 if (rslt != 0)
944 fatal("pthread_attr_get_np failed with error = %d", rslt);
945
946 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 ||
947 pthread_attr_getstacksize(&attr, size) != 0) {
948 fatal("Can not locate current stack attributes!");
949 }
950
951 pthread_attr_destroy(&attr);
952 #endif
953 assert(os::current_stack_pointer() >= *bottom &&
954 os::current_stack_pointer() < *bottom + *size, "just checking");
955 }
956
957 address os::current_stack_base() {
958 address bottom;
959 size_t size;
960 current_stack_region(&bottom, &size);
961 return (bottom + size);
962 }
963
964 size_t os::current_stack_size() {
965 // stack size includes normal stack and HotSpot guard pages
966 address bottom;
967 size_t size;
968 current_stack_region(&bottom, &size);
969 return size;
970 }
971
972 /////////////////////////////////////////////////////////////////////////////
973 // helper functions for fatal error handler
974
975 void os::print_context(outputStream *st, const void *context) {
976 if (context == NULL) return;
977
978 const ucontext_t *uc = (const ucontext_t*)context;
979 st->print_cr("Registers:");
980 #ifdef AMD64
981 st->print( "RAX=" INTPTR_FORMAT, (intptr_t)uc->context_rax);
982 st->print(", RBX=" INTPTR_FORMAT, (intptr_t)uc->context_rbx);
983 st->print(", RCX=" INTPTR_FORMAT, (intptr_t)uc->context_rcx);
984 st->print(", RDX=" INTPTR_FORMAT, (intptr_t)uc->context_rdx);
985 st->cr();
986 st->print( "RSP=" INTPTR_FORMAT, (intptr_t)uc->context_rsp);
987 st->print(", RBP=" INTPTR_FORMAT, (intptr_t)uc->context_rbp);
988 st->print(", RSI=" INTPTR_FORMAT, (intptr_t)uc->context_rsi);
989 st->print(", RDI=" INTPTR_FORMAT, (intptr_t)uc->context_rdi);
990 st->cr();
991 st->print( "R8 =" INTPTR_FORMAT, (intptr_t)uc->context_r8);
992 st->print(", R9 =" INTPTR_FORMAT, (intptr_t)uc->context_r9);
993 st->print(", R10=" INTPTR_FORMAT, (intptr_t)uc->context_r10);
994 st->print(", R11=" INTPTR_FORMAT, (intptr_t)uc->context_r11);
995 st->cr();
996 st->print( "R12=" INTPTR_FORMAT, (intptr_t)uc->context_r12);
997 st->print(", R13=" INTPTR_FORMAT, (intptr_t)uc->context_r13);
998 st->print(", R14=" INTPTR_FORMAT, (intptr_t)uc->context_r14);
999 st->print(", R15=" INTPTR_FORMAT, (intptr_t)uc->context_r15);
1000 st->cr();
1001 st->print( "RIP=" INTPTR_FORMAT, (intptr_t)uc->context_rip);
1002 st->print(", EFLAGS=" INTPTR_FORMAT, (intptr_t)uc->context_flags);
1003 st->print(", ERR=" INTPTR_FORMAT, (intptr_t)uc->context_err);
1004 st->cr();
1005 st->print(" TRAPNO=" INTPTR_FORMAT, (intptr_t)uc->context_trapno);
1006 #else
1007 st->print( "EAX=" INTPTR_FORMAT, (intptr_t)uc->context_eax);
1008 st->print(", EBX=" INTPTR_FORMAT, (intptr_t)uc->context_ebx);
1009 st->print(", ECX=" INTPTR_FORMAT, (intptr_t)uc->context_ecx);
1010 st->print(", EDX=" INTPTR_FORMAT, (intptr_t)uc->context_edx);
1011 st->cr();
1012 st->print( "ESP=" INTPTR_FORMAT, (intptr_t)uc->context_esp);
1013 st->print(", EBP=" INTPTR_FORMAT, (intptr_t)uc->context_ebp);
1014 st->print(", ESI=" INTPTR_FORMAT, (intptr_t)uc->context_esi);
1015 st->print(", EDI=" INTPTR_FORMAT, (intptr_t)uc->context_edi);
1016 st->cr();
1017 st->print( "EIP=" INTPTR_FORMAT, (intptr_t)uc->context_eip);
1018 st->print(", EFLAGS=" INTPTR_FORMAT, (intptr_t)uc->context_eflags);
1019 #endif // AMD64
1020 st->cr();
1021 st->cr();
1022
1023 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc);
1024 st->print_cr("Top of Stack: (sp=" INTPTR_FORMAT ")", (intptr_t)sp);
1025 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
1026 st->cr();
1027
1028 // Note: it may be unsafe to inspect memory near pc. For example, pc may
1029 // point to garbage if entry point in an nmethod is corrupted. Leave
1030 // this at the end, and hope for the best.
1031 address pc = os::Bsd::ucontext_get_pc(uc);
1032 print_instructions(st, pc, sizeof(char));
1033 st->cr();
1034 }
1035
1036 void os::print_register_info(outputStream *st, const void *context) {
1037 if (context == NULL) return;
1038
1039 const ucontext_t *uc = (const ucontext_t*)context;
1040
1041 st->print_cr("Register to memory mapping:");
1042 st->cr();
1043
1044 // this is horrendously verbose but the layout of the registers in the
1045 // context does not match how we defined our abstract Register set, so
1046 // we can't just iterate through the gregs area
1047
1048 // this is only for the "general purpose" registers
1049
1050 #ifdef AMD64
1051 st->print("RAX="); print_location(st, uc->context_rax);
1052 st->print("RBX="); print_location(st, uc->context_rbx);
1053 st->print("RCX="); print_location(st, uc->context_rcx);
1054 st->print("RDX="); print_location(st, uc->context_rdx);
1055 st->print("RSP="); print_location(st, uc->context_rsp);
1056 st->print("RBP="); print_location(st, uc->context_rbp);
1057 st->print("RSI="); print_location(st, uc->context_rsi);
1058 st->print("RDI="); print_location(st, uc->context_rdi);
1059 st->print("R8 ="); print_location(st, uc->context_r8);
1060 st->print("R9 ="); print_location(st, uc->context_r9);
1061 st->print("R10="); print_location(st, uc->context_r10);
1062 st->print("R11="); print_location(st, uc->context_r11);
1063 st->print("R12="); print_location(st, uc->context_r12);
1064 st->print("R13="); print_location(st, uc->context_r13);
1065 st->print("R14="); print_location(st, uc->context_r14);
1066 st->print("R15="); print_location(st, uc->context_r15);
1067 #else
1068 st->print("EAX="); print_location(st, uc->context_eax);
1069 st->print("EBX="); print_location(st, uc->context_ebx);
1070 st->print("ECX="); print_location(st, uc->context_ecx);
1071 st->print("EDX="); print_location(st, uc->context_edx);
1072 st->print("ESP="); print_location(st, uc->context_esp);
1073 st->print("EBP="); print_location(st, uc->context_ebp);
1074 st->print("ESI="); print_location(st, uc->context_esi);
1075 st->print("EDI="); print_location(st, uc->context_edi);
1076 #endif // AMD64
1077
1078 st->cr();
1079 }
1080
1081 void os::setup_fpu() {
1082 #ifndef AMD64
1083 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
1084 __asm__ volatile ( "fldcw (%0)" :
1085 : "r" (fpu_cntrl) : "memory");
1086 #endif // !AMD64
1087 }
1088
1089 #ifndef PRODUCT
1090 void os::verify_stack_alignment() {
1091 }
1092 #endif
1093
1094 int os::extra_bang_size_in_bytes() {
1095 // JDK-8050147 requires the full cache line bang for x86.
1096 return VM_Version::L1_line_size();
1097 }