1 /*
2 * Copyright (c) 1999, 2009, 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 // do not include precompiled header file
26 # include "incls/_os_linux_x86.cpp.incl"
27
28 // put OS-includes here
29 # include <sys/types.h>
30 # include <sys/mman.h>
31 # include <pthread.h>
32 # include <signal.h>
33 # include <errno.h>
34 # include <dlfcn.h>
35 # include <stdlib.h>
36 # include <stdio.h>
37 # include <unistd.h>
38 # include <sys/resource.h>
39 # include <pthread.h>
40 # include <sys/stat.h>
41 # include <sys/time.h>
42 # include <sys/utsname.h>
43 # include <sys/socket.h>
44 # include <sys/wait.h>
45 # include <pwd.h>
46 # include <poll.h>
47 # include <ucontext.h>
48 # include <fpu_control.h>
49
50 #ifdef AMD64
51 #define REG_SP REG_RSP
52 #define REG_PC REG_RIP
53 #define REG_FP REG_RBP
54 #define SPELL_REG_SP "rsp"
55 #define SPELL_REG_FP "rbp"
56 #else
57 #define REG_SP REG_UESP
58 #define REG_PC REG_EIP
59 #define REG_FP REG_EBP
60 #define SPELL_REG_SP "esp"
61 #define SPELL_REG_FP "ebp"
62 #endif // AMD64
63
64 address os::current_stack_pointer() {
65 #ifdef SPARC_WORKS
66 register void *esp;
67 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp));
68 return (address) ((char*)esp + sizeof(long)*2);
69 #else
70 register void *esp __asm__ (SPELL_REG_SP);
71 return (address) esp;
72 #endif
73 }
74
75 char* os::non_memory_address_word() {
76 // Must never look like an address returned by reserve_memory,
77 // even in its subfields (as defined by the CPU immediate fields,
78 // if the CPU splits constants across multiple instructions).
79
80 return (char*) -1;
81 }
82
83 void os::initialize_thread() {
84 // Nothing to do.
85 }
86
87 address os::Linux::ucontext_get_pc(ucontext_t * uc) {
88 return (address)uc->uc_mcontext.gregs[REG_PC];
89 }
90
91 intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) {
92 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
93 }
94
95 intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) {
96 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
97 }
98
99 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
100 // is currently interrupted by SIGPROF.
101 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
102 // frames. Currently we don't do that on Linux, so it's the same as
103 // os::fetch_frame_from_context().
104 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
105 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
106
107 assert(thread != NULL, "just checking");
108 assert(ret_sp != NULL, "just checking");
109 assert(ret_fp != NULL, "just checking");
110
111 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
112 }
113
114 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
115 intptr_t** ret_sp, intptr_t** ret_fp) {
116
117 ExtendedPC epc;
118 ucontext_t* uc = (ucontext_t*)ucVoid;
119
120 if (uc != NULL) {
121 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
122 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc);
123 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc);
124 } else {
125 // construct empty ExtendedPC for return value checking
126 epc = ExtendedPC(NULL);
127 if (ret_sp) *ret_sp = (intptr_t *)NULL;
128 if (ret_fp) *ret_fp = (intptr_t *)NULL;
129 }
130
131 return epc;
132 }
133
134 frame os::fetch_frame_from_context(void* ucVoid) {
135 intptr_t* sp;
136 intptr_t* fp;
137 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
138 return frame(sp, fp, epc.pc());
139 }
140
141 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get
142 // turned off by -fomit-frame-pointer,
143 frame os::get_sender_for_C_frame(frame* fr) {
144 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
145 }
146
147 intptr_t* _get_previous_fp() {
148 #ifdef SPARC_WORKS
149 register intptr_t **ebp;
150 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp));
151 #else
152 register intptr_t **ebp __asm__ (SPELL_REG_FP);
153 #endif
154 return (intptr_t*) *ebp; // we want what it points to.
155 }
156
157
158 frame os::current_frame() {
159 intptr_t* fp = _get_previous_fp();
160 frame myframe((intptr_t*)os::current_stack_pointer(),
161 (intptr_t*)fp,
162 CAST_FROM_FN_PTR(address, os::current_frame));
163 if (os::is_first_C_frame(&myframe)) {
164 // stack is not walkable
165 return frame(NULL, NULL, NULL);
166 } else {
167 return os::get_sender_for_C_frame(&myframe);
168 }
169 }
170
171 // Utility functions
172
173 // From IA32 System Programming Guide
174 enum {
175 trap_page_fault = 0xE
176 };
177
178 extern "C" void Fetch32PFI () ;
179 extern "C" void Fetch32Resume () ;
180 #ifdef AMD64
181 extern "C" void FetchNPFI () ;
182 extern "C" void FetchNResume () ;
183 #endif // AMD64
184
185 extern "C" int
186 JVM_handle_linux_signal(int sig,
187 siginfo_t* info,
188 void* ucVoid,
189 int abort_if_unrecognized) {
190 ucontext_t* uc = (ucontext_t*) ucVoid;
191
192 Thread* t = ThreadLocalStorage::get_thread_slow();
193
194 SignalHandlerMark shm(t);
195
196 // Note: it's not uncommon that JNI code uses signal/sigset to install
197 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
198 // or have a SIGILL handler when detecting CPU type). When that happens,
199 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
200 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
201 // that do not require siginfo/ucontext first.
202
203 if (sig == SIGPIPE || sig == SIGXFSZ) {
204 // allow chained handler to go first
205 if (os::Linux::chained_handler(sig, info, ucVoid)) {
206 return true;
207 } else {
208 if (PrintMiscellaneous && (WizardMode || Verbose)) {
209 char buf[64];
210 warning("Ignoring %s - see bugs 4229104 or 646499219",
211 os::exception_name(sig, buf, sizeof(buf)));
212 }
213 return true;
214 }
215 }
216
217 JavaThread* thread = NULL;
218 VMThread* vmthread = NULL;
219 if (os::Linux::signal_handlers_are_installed) {
220 if (t != NULL ){
221 if(t->is_Java_thread()) {
222 thread = (JavaThread*)t;
223 }
224 else if(t->is_VM_thread()){
225 vmthread = (VMThread *)t;
226 }
227 }
228 }
229 /*
230 NOTE: does not seem to work on linux.
231 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
232 // can't decode this kind of signal
233 info = NULL;
234 } else {
235 assert(sig == info->si_signo, "bad siginfo");
236 }
237 */
238 // decide if this trap can be handled by a stub
239 address stub = NULL;
240
241 address pc = NULL;
242
243 //%note os_trap_1
244 if (info != NULL && uc != NULL && thread != NULL) {
245 pc = (address) os::Linux::ucontext_get_pc(uc);
246
247 if (pc == (address) Fetch32PFI) {
248 uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ;
249 return 1 ;
250 }
251 #ifdef AMD64
252 if (pc == (address) FetchNPFI) {
253 uc->uc_mcontext.gregs[REG_PC] = intptr_t (FetchNResume) ;
254 return 1 ;
255 }
256 #endif // AMD64
257
258 // Handle ALL stack overflow variations here
259 if (sig == SIGSEGV) {
260 address addr = (address) info->si_addr;
261
262 // check if fault address is within thread stack
263 if (addr < thread->stack_base() &&
264 addr >= thread->stack_base() - thread->stack_size()) {
265 // stack overflow
266 if (thread->in_stack_yellow_zone(addr)) {
267 thread->disable_stack_yellow_zone();
268 if (thread->thread_state() == _thread_in_Java) {
269 // Throw a stack overflow exception. Guard pages will be reenabled
270 // while unwinding the stack.
271 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
272 } else {
273 // Thread was in the vm or native code. Return and try to finish.
274 return 1;
275 }
276 } else if (thread->in_stack_red_zone(addr)) {
277 // Fatal red zone violation. Disable the guard pages and fall through
278 // to handle_unexpected_exception way down below.
279 thread->disable_stack_red_zone();
280 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
281 } else {
282 // Accessing stack address below sp may cause SEGV if current
283 // thread has MAP_GROWSDOWN stack. This should only happen when
284 // current thread was created by user code with MAP_GROWSDOWN flag
285 // and then attached to VM. See notes in os_linux.cpp.
286 if (thread->osthread()->expanding_stack() == 0) {
287 thread->osthread()->set_expanding_stack();
288 if (os::Linux::manually_expand_stack(thread, addr)) {
289 thread->osthread()->clear_expanding_stack();
290 return 1;
291 }
292 thread->osthread()->clear_expanding_stack();
293 } else {
294 fatal("recursive segv. expanding stack.");
295 }
296 }
297 }
298 }
299
300 if (thread->thread_state() == _thread_in_Java) {
301 // Java thread running in Java code => find exception handler if any
302 // a fault inside compiled code, the interpreter, or a stub
303
304 if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
305 stub = SharedRuntime::get_poll_stub(pc);
306 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
307 // BugId 4454115: A read from a MappedByteBuffer can fault
308 // here if the underlying file has been truncated.
309 // Do not crash the VM in such a case.
310 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
311 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
312 if (nm != NULL && nm->has_unsafe_access()) {
313 stub = StubRoutines::handler_for_unsafe_access();
314 }
315 }
316 else
317
318 #ifdef AMD64
319 if (sig == SIGFPE &&
320 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
321 stub =
322 SharedRuntime::
323 continuation_for_implicit_exception(thread,
324 pc,
325 SharedRuntime::
326 IMPLICIT_DIVIDE_BY_ZERO);
327 #else
328 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) {
329 // HACK: si_code does not work on linux 2.2.12-20!!!
330 int op = pc[0];
331 if (op == 0xDB) {
332 // FIST
333 // TODO: The encoding of D2I in i486.ad can cause an exception
334 // prior to the fist instruction if there was an invalid operation
335 // pending. We want to dismiss that exception. From the win_32
336 // side it also seems that if it really was the fist causing
337 // the exception that we do the d2i by hand with different
338 // rounding. Seems kind of weird.
339 // NOTE: that we take the exception at the NEXT floating point instruction.
340 assert(pc[0] == 0xDB, "not a FIST opcode");
341 assert(pc[1] == 0x14, "not a FIST opcode");
342 assert(pc[2] == 0x24, "not a FIST opcode");
343 return true;
344 } else if (op == 0xF7) {
345 // IDIV
346 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
347 } else {
348 // TODO: handle more cases if we are using other x86 instructions
349 // that can generate SIGFPE signal on linux.
350 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
351 fatal("please update this code.");
352 }
353 #endif // AMD64
354 } else if (sig == SIGSEGV &&
355 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
356 // Determination of interpreter/vtable stub/compiled code null exception
357 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
358 }
359 } else if (thread->thread_state() == _thread_in_vm &&
360 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
361 thread->doing_unsafe_access()) {
362 stub = StubRoutines::handler_for_unsafe_access();
363 }
364
365 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
366 // and the heap gets shrunk before the field access.
367 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
368 address addr = JNI_FastGetField::find_slowcase_pc(pc);
369 if (addr != (address)-1) {
370 stub = addr;
371 }
372 }
373
374 // Check to see if we caught the safepoint code in the
375 // process of write protecting the memory serialization page.
376 // It write enables the page immediately after protecting it
377 // so we can just return to retry the write.
378 if ((sig == SIGSEGV) &&
379 os::is_memory_serialize_page(thread, (address) info->si_addr)) {
380 // Block current thread until the memory serialize page permission restored.
381 os::block_on_serialize_page_trap();
382 return true;
383 }
384 }
385
386 #ifndef AMD64
387 // Execution protection violation
388 //
389 // This should be kept as the last step in the triage. We don't
390 // have a dedicated trap number for a no-execute fault, so be
391 // conservative and allow other handlers the first shot.
392 //
393 // Note: We don't test that info->si_code == SEGV_ACCERR here.
394 // this si_code is so generic that it is almost meaningless; and
395 // the si_code for this condition may change in the future.
396 // Furthermore, a false-positive should be harmless.
397 if (UnguardOnExecutionViolation > 0 &&
398 (sig == SIGSEGV || sig == SIGBUS) &&
399 uc->uc_mcontext.gregs[REG_TRAPNO] == trap_page_fault) {
400 int page_size = os::vm_page_size();
401 address addr = (address) info->si_addr;
402 address pc = os::Linux::ucontext_get_pc(uc);
403 // Make sure the pc and the faulting address are sane.
404 //
405 // If an instruction spans a page boundary, and the page containing
406 // the beginning of the instruction is executable but the following
407 // page is not, the pc and the faulting address might be slightly
408 // different - we still want to unguard the 2nd page in this case.
409 //
410 // 15 bytes seems to be a (very) safe value for max instruction size.
411 bool pc_is_near_addr =
412 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
413 bool instr_spans_page_boundary =
414 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
415 (intptr_t) page_size) > 0);
416
417 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
418 static volatile address last_addr =
419 (address) os::non_memory_address_word();
420
421 // In conservative mode, don't unguard unless the address is in the VM
422 if (addr != last_addr &&
423 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
424
425 // Set memory to RWX and retry
426 address page_start =
427 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
428 bool res = os::protect_memory((char*) page_start, page_size,
429 os::MEM_PROT_RWX);
430
431 if (PrintMiscellaneous && Verbose) {
432 char buf[256];
433 jio_snprintf(buf, sizeof(buf), "Execution protection violation "
434 "at " INTPTR_FORMAT
435 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
436 page_start, (res ? "success" : "failed"), errno);
437 tty->print_raw_cr(buf);
438 }
439 stub = pc;
440
441 // Set last_addr so if we fault again at the same address, we don't end
442 // up in an endless loop.
443 //
444 // There are two potential complications here. Two threads trapping at
445 // the same address at the same time could cause one of the threads to
446 // think it already unguarded, and abort the VM. Likely very rare.
447 //
448 // The other race involves two threads alternately trapping at
449 // different addresses and failing to unguard the page, resulting in
450 // an endless loop. This condition is probably even more unlikely than
451 // the first.
452 //
453 // Although both cases could be avoided by using locks or thread local
454 // last_addr, these solutions are unnecessary complication: this
455 // handler is a best-effort safety net, not a complete solution. It is
456 // disabled by default and should only be used as a workaround in case
457 // we missed any no-execute-unsafe VM code.
458
459 last_addr = addr;
460 }
461 }
462 }
463 #endif // !AMD64
464
465 if (stub != NULL) {
466 // save all thread context in case we need to restore it
467 if (thread != NULL) thread->set_saved_exception_pc(pc);
468
469 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub;
470 return true;
471 }
472
473 // signal-chaining
474 if (os::Linux::chained_handler(sig, info, ucVoid)) {
475 return true;
476 }
477
478 if (!abort_if_unrecognized) {
479 // caller wants another chance, so give it to him
480 return false;
481 }
482
483 if (pc == NULL && uc != NULL) {
484 pc = os::Linux::ucontext_get_pc(uc);
485 }
486
487 // unmask current signal
488 sigset_t newset;
489 sigemptyset(&newset);
490 sigaddset(&newset, sig);
491 sigprocmask(SIG_UNBLOCK, &newset, NULL);
492
493 VMError err(t, sig, pc, info, ucVoid);
494 err.report_and_die();
495
496 ShouldNotReachHere();
497 }
498
499 void os::Linux::init_thread_fpu_state(void) {
500 #ifndef AMD64
501 // set fpu to 53 bit precision
502 set_fpu_control_word(0x27f);
503 #endif // !AMD64
504 }
505
506 int os::Linux::get_fpu_control_word(void) {
507 #ifdef AMD64
508 return 0;
509 #else
510 int fpu_control;
511 _FPU_GETCW(fpu_control);
512 return fpu_control & 0xffff;
513 #endif // AMD64
514 }
515
516 void os::Linux::set_fpu_control_word(int fpu_control) {
517 #ifndef AMD64
518 _FPU_SETCW(fpu_control);
519 #endif // !AMD64
520 }
521
522 // Check that the linux kernel version is 2.4 or higher since earlier
523 // versions do not support SSE without patches.
524 bool os::supports_sse() {
525 #ifdef AMD64
526 return true;
527 #else
528 struct utsname uts;
529 if( uname(&uts) != 0 ) return false; // uname fails?
530 char *minor_string;
531 int major = strtol(uts.release,&minor_string,10);
532 int minor = strtol(minor_string+1,NULL,10);
533 bool result = (major > 2 || (major==2 && minor >= 4));
534 #ifndef PRODUCT
535 if (PrintMiscellaneous && Verbose) {
536 tty->print("OS version is %d.%d, which %s support SSE/SSE2\n",
537 major,minor, result ? "DOES" : "does NOT");
538 }
539 #endif
540 return result;
541 #endif // AMD64
542 }
543
544 bool os::is_allocatable(size_t bytes) {
545 #ifdef AMD64
546 // unused on amd64?
547 return true;
548 #else
549
550 if (bytes < 2 * G) {
551 return true;
552 }
553
554 char* addr = reserve_memory(bytes, NULL);
555
556 if (addr != NULL) {
557 release_memory(addr, bytes);
558 }
559
560 return addr != NULL;
561 #endif // AMD64
562 }
563
564 ////////////////////////////////////////////////////////////////////////////////
565 // thread stack
566
567 #ifdef AMD64
568 size_t os::Linux::min_stack_allowed = 64 * K;
569
570 // amd64: pthread on amd64 is always in floating stack mode
571 bool os::Linux::supports_variable_stack_size() { return true; }
572 #else
573 size_t os::Linux::min_stack_allowed = (48 DEBUG_ONLY(+4))*K;
574
575 #ifdef __GNUC__
576 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;})
577 #endif
578
579 // Test if pthread library can support variable thread stack size. LinuxThreads
580 // in fixed stack mode allocates 2M fixed slot for each thread. LinuxThreads
581 // in floating stack mode and NPTL support variable stack size.
582 bool os::Linux::supports_variable_stack_size() {
583 if (os::Linux::is_NPTL()) {
584 // NPTL, yes
585 return true;
586
587 } else {
588 // Note: We can't control default stack size when creating a thread.
589 // If we use non-default stack size (pthread_attr_setstacksize), both
590 // floating stack and non-floating stack LinuxThreads will return the
591 // same value. This makes it impossible to implement this function by
592 // detecting thread stack size directly.
593 //
594 // An alternative approach is to check %gs. Fixed-stack LinuxThreads
595 // do not use %gs, so its value is 0. Floating-stack LinuxThreads use
596 // %gs (either as LDT selector or GDT selector, depending on kernel)
597 // to access thread specific data.
598 //
599 // Note that %gs is a reserved glibc register since early 2001, so
600 // applications are not allowed to change its value (Ulrich Drepper from
601 // Redhat confirmed that all known offenders have been modified to use
602 // either %fs or TSD). In the worst case scenario, when VM is embedded in
603 // a native application that plays with %gs, we might see non-zero %gs
604 // even LinuxThreads is running in fixed stack mode. As the result, we'll
605 // return true and skip _thread_safety_check(), so we may not be able to
606 // detect stack-heap collisions. But otherwise it's harmless.
607 //
608 #ifdef __GNUC__
609 return (GET_GS() != 0);
610 #else
611 return false;
612 #endif
613 }
614 }
615 #endif // AMD64
616
617 // return default stack size for thr_type
618 size_t os::Linux::default_stack_size(os::ThreadType thr_type) {
619 // default stack size (compiler thread needs larger stack)
620 #ifdef AMD64
621 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
622 #else
623 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
624 #endif // AMD64
625 return s;
626 }
627
628 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
629 // Creating guard page is very expensive. Java thread has HotSpot
630 // guard page, only enable glibc guard page for non-Java threads.
631 return (thr_type == java_thread ? 0 : page_size());
632 }
633
634 // Java thread:
635 //
636 // Low memory addresses
637 // +------------------------+
638 // | |\ JavaThread created by VM does not have glibc
639 // | glibc guard page | - guard, attached Java thread usually has
640 // | |/ 1 page glibc guard.
641 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
642 // | |\
643 // | HotSpot Guard Pages | - red and yellow pages
644 // | |/
645 // +------------------------+ JavaThread::stack_yellow_zone_base()
646 // | |\
647 // | Normal Stack | -
648 // | |/
649 // P2 +------------------------+ Thread::stack_base()
650 //
651 // Non-Java thread:
652 //
653 // Low memory addresses
654 // +------------------------+
655 // | |\
656 // | glibc guard page | - usually 1 page
657 // | |/
658 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
659 // | |\
660 // | Normal Stack | -
661 // | |/
662 // P2 +------------------------+ Thread::stack_base()
663 //
664 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
665 // pthread_attr_getstack()
666
667 static void current_stack_region(address * bottom, size_t * size) {
668 if (os::Linux::is_initial_thread()) {
669 // initial thread needs special handling because pthread_getattr_np()
670 // may return bogus value.
671 *bottom = os::Linux::initial_thread_stack_bottom();
672 *size = os::Linux::initial_thread_stack_size();
673 } else {
674 pthread_attr_t attr;
675
676 int rslt = pthread_getattr_np(pthread_self(), &attr);
677
678 // JVM needs to know exact stack location, abort if it fails
679 if (rslt != 0) {
680 if (rslt == ENOMEM) {
681 vm_exit_out_of_memory(0, "pthread_getattr_np");
682 } else {
683 fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt));
684 }
685 }
686
687 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
688 fatal("Can not locate current stack attributes!");
689 }
690
691 pthread_attr_destroy(&attr);
692
693 }
694 assert(os::current_stack_pointer() >= *bottom &&
695 os::current_stack_pointer() < *bottom + *size, "just checking");
696 }
697
698 address os::current_stack_base() {
699 address bottom;
700 size_t size;
701 current_stack_region(&bottom, &size);
702 return (bottom + size);
703 }
704
705 size_t os::current_stack_size() {
706 // stack size includes normal stack and HotSpot guard pages
707 address bottom;
708 size_t size;
709 current_stack_region(&bottom, &size);
710 return size;
711 }
712
713 /////////////////////////////////////////////////////////////////////////////
714 // helper functions for fatal error handler
715
716 void os::print_context(outputStream *st, void *context) {
717 if (context == NULL) return;
718
719 ucontext_t *uc = (ucontext_t*)context;
720 st->print_cr("Registers:");
721
722 // this is horrendously verbose but the layout of the registers in the
723 // context does not match how we defined our abstract Register set, so
724 // we can't just iterate through the gregs area
725
726 #ifdef AMD64
727 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
728 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
729 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
730 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
731 st->cr();
732 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
733 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
734 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
735 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
736 st->cr();
737 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
738 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
739 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
740 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
741 st->cr();
742 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
743 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
744 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
745 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
746 st->cr();
747 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
748 st->print(", EFL=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]);
749 st->print(", CSGSFS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_CSGSFS]);
750 st->print(", ERR=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ERR]);
751 st->cr();
752 st->print(" TRAPNO=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_TRAPNO]);
753
754 st->cr();
755 st->cr();
756
757 st->print_cr("Register to memory mapping:");
758 st->cr();
759
760 // this is only for the "general purpose" registers
761
762 st->print_cr("RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
763 print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
764 st->cr();
765 st->print_cr("RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
766 print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
767 st->cr();
768 st->print_cr("RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
769 print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
770 st->cr();
771 st->print_cr("RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
772 print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
773 st->cr();
774 st->print_cr("RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
775 print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
776 st->cr();
777 st->print_cr("RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
778 print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
779 st->cr();
780 st->print_cr("RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
781 print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
782 st->cr();
783 st->print_cr("RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
784 print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
785 st->cr();
786 st->print_cr("R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
787 print_location(st, uc->uc_mcontext.gregs[REG_R8]);
788 st->cr();
789 st->print_cr("R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
790 print_location(st, uc->uc_mcontext.gregs[REG_R9]);
791 st->cr();
792 st->print_cr("R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
793 print_location(st, uc->uc_mcontext.gregs[REG_R10]);
794 st->cr();
795 st->print_cr("R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
796 print_location(st, uc->uc_mcontext.gregs[REG_R11]);
797 st->cr();
798 st->print_cr("R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
799 print_location(st, uc->uc_mcontext.gregs[REG_R12]);
800 st->cr();
801 st->print_cr("R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
802 print_location(st, uc->uc_mcontext.gregs[REG_R13]);
803 st->cr();
804 st->print_cr("R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
805 print_location(st, uc->uc_mcontext.gregs[REG_R14]);
806 st->cr();
807 st->print_cr("R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
808 print_location(st, uc->uc_mcontext.gregs[REG_R15]);
809
810 #else
811 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EAX]);
812 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBX]);
813 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ECX]);
814 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDX]);
815 st->cr();
816 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_UESP]);
817 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBP]);
818 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ESI]);
819 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDI]);
820 st->cr();
821 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EIP]);
822 st->print(", CR2=" INTPTR_FORMAT, uc->uc_mcontext.cr2);
823 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]);
824
825 st->cr();
826 st->cr();
827
828 st->print_cr("Register to memory mapping:");
829 st->cr();
830
831 // this is only for the "general purpose" registers
832
833 st->print_cr("EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EAX]);
834 print_location(st, uc->uc_mcontext.gregs[REG_EAX]);
835 st->cr();
836 st->print_cr("EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBX]);
837 print_location(st, uc->uc_mcontext.gregs[REG_EBX]);
838 st->cr();
839 st->print_cr("ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ECX]);
840 print_location(st, uc->uc_mcontext.gregs[REG_ECX]);
841 st->cr();
842 st->print_cr("EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDX]);
843 print_location(st, uc->uc_mcontext.gregs[REG_EDX]);
844 st->cr();
845 st->print_cr("ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ESP]);
846 print_location(st, uc->uc_mcontext.gregs[REG_ESP]);
847 st->cr();
848 st->print_cr("EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBP]);
849 print_location(st, uc->uc_mcontext.gregs[REG_EBP]);
850 st->cr();
851 st->print_cr("ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ESI]);
852 print_location(st, uc->uc_mcontext.gregs[REG_ESI]);
853 st->cr();
854 st->print_cr("EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDI]);
855 print_location(st, uc->uc_mcontext.gregs[REG_EDI]);
856
857 #endif // AMD64
858 st->cr();
859 st->cr();
860
861 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
862 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
863 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
864 st->cr();
865
866 // Note: it may be unsafe to inspect memory near pc. For example, pc may
867 // point to garbage if entry point in an nmethod is corrupted. Leave
868 // this at the end, and hope for the best.
869 address pc = os::Linux::ucontext_get_pc(uc);
870 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
871 print_hex_dump(st, pc - 16, pc + 16, sizeof(char));
872 }
873
874 void os::setup_fpu() {
875 #ifndef AMD64
876 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
877 __asm__ volatile ( "fldcw (%0)" :
878 : "r" (fpu_cntrl) : "memory");
879 #endif // !AMD64
880 }