1 #ifdef USE_PRAGMA_IDENT_SRC
2 #pragma ident "@(#)os_linux_x86.cpp 1.98 07/11/15 11:29:19 JVM"
3 #endif
4 /*
5 * Copyright 1999-2007 Sun Microsystems, Inc. All Rights Reserved.
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7 *
8 * This code is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 only, as
10 * published by the Free Software Foundation.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
24 * have any questions.
25 *
26 */
27
28 // do not include precompiled header file
29 # include "incls/_os_linux_x86.cpp.incl"
30
31 // put OS-includes here
32 # include <sys/types.h>
33 # include <sys/mman.h>
34 # include <pthread.h>
35 # include <signal.h>
36 # include <errno.h>
37 # include <dlfcn.h>
38 # include <stdlib.h>
39 # include <stdio.h>
40 # include <unistd.h>
41 # include <sys/resource.h>
42 # include <pthread.h>
43 # include <sys/stat.h>
44 # include <sys/time.h>
45 # include <sys/utsname.h>
46 # include <sys/socket.h>
47 # include <sys/wait.h>
48 # include <pwd.h>
49 # include <poll.h>
50 # include <ucontext.h>
51 # include <fpu_control.h>
52
53 #ifdef AMD64
54 #define REG_SP REG_RSP
55 #define REG_PC REG_RIP
56 #define REG_FP REG_RBP
57 #define SPELL_REG_SP "rsp"
58 #define SPELL_REG_FP "rbp"
59 #else
60 #define REG_SP REG_UESP
61 #define REG_PC REG_EIP
62 #define REG_FP REG_EBP
63 #define SPELL_REG_SP "esp"
64 #define SPELL_REG_FP "ebp"
65 #endif // AMD64
66
67 address os::current_stack_pointer() {
68 register void *esp __asm__ (SPELL_REG_SP);
69 return (address) esp;
70 }
71
72 char* os::non_memory_address_word() {
73 // Must never look like an address returned by reserve_memory,
74 // even in its subfields (as defined by the CPU immediate fields,
75 // if the CPU splits constants across multiple instructions).
76
77 return (char*) -1;
78 }
79
80 void os::initialize_thread() {
81 // Nothing to do.
82 }
83
84 address os::Linux::ucontext_get_pc(ucontext_t * uc) {
85 return (address)uc->uc_mcontext.gregs[REG_PC];
86 }
87
88 intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) {
89 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
90 }
91
92 intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) {
93 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
94 }
95
96 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
97 // is currently interrupted by SIGPROF.
98 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
99 // frames. Currently we don't do that on Linux, so it's the same as
100 // os::fetch_frame_from_context().
101 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
102 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
103
104 assert(thread != NULL, "just checking");
105 assert(ret_sp != NULL, "just checking");
106 assert(ret_fp != NULL, "just checking");
107
108 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
109 }
110
111 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
112 intptr_t** ret_sp, intptr_t** ret_fp) {
113
114 ExtendedPC epc;
115 ucontext_t* uc = (ucontext_t*)ucVoid;
116
117 if (uc != NULL) {
118 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
119 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc);
120 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc);
121 } else {
122 // construct empty ExtendedPC for return value checking
123 epc = ExtendedPC(NULL);
124 if (ret_sp) *ret_sp = (intptr_t *)NULL;
125 if (ret_fp) *ret_fp = (intptr_t *)NULL;
126 }
127
128 return epc;
129 }
130
131 frame os::fetch_frame_from_context(void* ucVoid) {
132 intptr_t* sp;
133 intptr_t* fp;
134 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
135 return frame(sp, fp, epc.pc());
136 }
137
138 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get
139 // turned off by -fomit-frame-pointer,
140 frame os::get_sender_for_C_frame(frame* fr) {
141 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
142 }
143
144 intptr_t* _get_previous_fp() {
145 register intptr_t **ebp __asm__ (SPELL_REG_FP);
146 return (intptr_t*) *ebp; // we want what it points to.
147 }
148
149
150 frame os::current_frame() {
151 intptr_t* fp = _get_previous_fp();
152 frame myframe((intptr_t*)os::current_stack_pointer(),
153 (intptr_t*)fp,
154 CAST_FROM_FN_PTR(address, os::current_frame));
155 if (os::is_first_C_frame(&myframe)) {
156 // stack is not walkable
157 return frame(NULL, NULL, NULL);
158 } else {
159 return os::get_sender_for_C_frame(&myframe);
160 }
161 }
162
163 // Utility functions
164
165 // From IA32 System Programming Guide
166 enum {
167 trap_page_fault = 0xE
168 };
169
170 extern "C" void Fetch32PFI () ;
171 extern "C" void Fetch32Resume () ;
172 #ifdef AMD64
173 extern "C" void FetchNPFI () ;
174 extern "C" void FetchNResume () ;
175 #endif // AMD64
176
177 extern "C" int
178 JVM_handle_linux_signal(int sig,
179 siginfo_t* info,
180 void* ucVoid,
181 int abort_if_unrecognized) {
182 ucontext_t* uc = (ucontext_t*) ucVoid;
183
184 Thread* t = ThreadLocalStorage::get_thread_slow();
185
186 SignalHandlerMark shm(t);
187
188 // Note: it's not uncommon that JNI code uses signal/sigset to install
189 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
190 // or have a SIGILL handler when detecting CPU type). When that happens,
191 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
192 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
193 // that do not require siginfo/ucontext first.
194
195 if (sig == SIGPIPE || sig == SIGXFSZ) {
196 // allow chained handler to go first
197 if (os::Linux::chained_handler(sig, info, ucVoid)) {
198 return true;
199 } else {
200 if (PrintMiscellaneous && (WizardMode || Verbose)) {
201 char buf[64];
202 warning("Ignoring %s - see bugs 4229104 or 646499219",
203 os::exception_name(sig, buf, sizeof(buf)));
204 }
205 return true;
206 }
207 }
208
209 JavaThread* thread = NULL;
210 VMThread* vmthread = NULL;
211 if (os::Linux::signal_handlers_are_installed) {
212 if (t != NULL ){
213 if(t->is_Java_thread()) {
214 thread = (JavaThread*)t;
215 }
216 else if(t->is_VM_thread()){
217 vmthread = (VMThread *)t;
218 }
219 }
220 }
221 /*
222 NOTE: does not seem to work on linux.
223 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
224 // can't decode this kind of signal
225 info = NULL;
226 } else {
227 assert(sig == info->si_signo, "bad siginfo");
228 }
229 */
230 // decide if this trap can be handled by a stub
231 address stub = NULL;
232
233 address pc = NULL;
234
235 //%note os_trap_1
236 if (info != NULL && uc != NULL && thread != NULL) {
237 pc = (address) os::Linux::ucontext_get_pc(uc);
238
239 if (pc == (address) Fetch32PFI) {
240 uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ;
241 return 1 ;
242 }
243 #ifdef AMD64
244 if (pc == (address) FetchNPFI) {
245 uc->uc_mcontext.gregs[REG_PC] = intptr_t (FetchNResume) ;
246 return 1 ;
247 }
248 #endif // AMD64
249
250 // Handle ALL stack overflow variations here
251 if (sig == SIGSEGV) {
252 address addr = (address) info->si_addr;
253
254 // check if fault address is within thread stack
255 if (addr < thread->stack_base() &&
256 addr >= thread->stack_base() - thread->stack_size()) {
257 // stack overflow
258 if (thread->in_stack_yellow_zone(addr)) {
259 thread->disable_stack_yellow_zone();
260 if (thread->thread_state() == _thread_in_Java) {
261 // Throw a stack overflow exception. Guard pages will be reenabled
262 // while unwinding the stack.
263 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
264 } else {
265 // Thread was in the vm or native code. Return and try to finish.
266 return 1;
267 }
268 } else if (thread->in_stack_red_zone(addr)) {
269 // Fatal red zone violation. Disable the guard pages and fall through
270 // to handle_unexpected_exception way down below.
271 thread->disable_stack_red_zone();
272 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
273 } else {
274 // Accessing stack address below sp may cause SEGV if current
275 // thread has MAP_GROWSDOWN stack. This should only happen when
276 // current thread was created by user code with MAP_GROWSDOWN flag
277 // and then attached to VM. See notes in os_linux.cpp.
278 if (thread->osthread()->expanding_stack() == 0) {
279 thread->osthread()->set_expanding_stack();
280 if (os::Linux::manually_expand_stack(thread, addr)) {
281 thread->osthread()->clear_expanding_stack();
282 return 1;
283 }
284 thread->osthread()->clear_expanding_stack();
285 } else {
286 fatal("recursive segv. expanding stack.");
287 }
288 }
289 }
290 }
291
292 if (thread->thread_state() == _thread_in_Java) {
293 // Java thread running in Java code => find exception handler if any
294 // a fault inside compiled code, the interpreter, or a stub
295
296 if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
297 stub = SharedRuntime::get_poll_stub(pc);
298 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
299 // BugId 4454115: A read from a MappedByteBuffer can fault
300 // here if the underlying file has been truncated.
301 // Do not crash the VM in such a case.
302 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
303 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
304 if (nm != NULL && nm->has_unsafe_access()) {
305 stub = StubRoutines::handler_for_unsafe_access();
306 }
307 }
308 else
309
310 #ifdef AMD64
311 if (sig == SIGFPE &&
312 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
313 stub =
314 SharedRuntime::
315 continuation_for_implicit_exception(thread,
316 pc,
317 SharedRuntime::
318 IMPLICIT_DIVIDE_BY_ZERO);
319 #else
320 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) {
321 // HACK: si_code does not work on linux 2.2.12-20!!!
322 int op = pc[0];
323 if (op == 0xDB) {
324 // FIST
325 // TODO: The encoding of D2I in i486.ad can cause an exception
326 // prior to the fist instruction if there was an invalid operation
327 // pending. We want to dismiss that exception. From the win_32
328 // side it also seems that if it really was the fist causing
329 // the exception that we do the d2i by hand with different
330 // rounding. Seems kind of weird.
331 // NOTE: that we take the exception at the NEXT floating point instruction.
332 assert(pc[0] == 0xDB, "not a FIST opcode");
333 assert(pc[1] == 0x14, "not a FIST opcode");
334 assert(pc[2] == 0x24, "not a FIST opcode");
335 return true;
336 } else if (op == 0xF7) {
337 // IDIV
338 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
339 } else {
340 // TODO: handle more cases if we are using other x86 instructions
341 // that can generate SIGFPE signal on linux.
342 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
343 fatal("please update this code.");
344 }
345 #endif // AMD64
346 } else if (sig == SIGSEGV &&
347 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
348 // Determination of interpreter/vtable stub/compiled code null exception
349 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
350 }
351 } else if (thread->thread_state() == _thread_in_vm &&
352 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
353 thread->doing_unsafe_access()) {
354 stub = StubRoutines::handler_for_unsafe_access();
355 }
356
357 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
358 // and the heap gets shrunk before the field access.
359 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
360 address addr = JNI_FastGetField::find_slowcase_pc(pc);
361 if (addr != (address)-1) {
362 stub = addr;
363 }
364 }
365
366 // Check to see if we caught the safepoint code in the
367 // process of write protecting the memory serialization page.
368 // It write enables the page immediately after protecting it
369 // so we can just return to retry the write.
370 if ((sig == SIGSEGV) &&
371 os::is_memory_serialize_page(thread, (address) info->si_addr)) {
372 // Block current thread until the memory serialize page permission restored.
373 os::block_on_serialize_page_trap();
374 return true;
375 }
376 }
377
378 #ifndef AMD64
379 // Execution protection violation
380 //
381 // This should be kept as the last step in the triage. We don't
382 // have a dedicated trap number for a no-execute fault, so be
383 // conservative and allow other handlers the first shot.
384 //
385 // Note: We don't test that info->si_code == SEGV_ACCERR here.
386 // this si_code is so generic that it is almost meaningless; and
387 // the si_code for this condition may change in the future.
388 // Furthermore, a false-positive should be harmless.
389 if (UnguardOnExecutionViolation > 0 &&
390 (sig == SIGSEGV || sig == SIGBUS) &&
391 uc->uc_mcontext.gregs[REG_TRAPNO] == trap_page_fault) {
392 int page_size = os::vm_page_size();
393 address addr = (address) info->si_addr;
394 address pc = os::Linux::ucontext_get_pc(uc);
395 // Make sure the pc and the faulting address are sane.
396 //
397 // If an instruction spans a page boundary, and the page containing
398 // the beginning of the instruction is executable but the following
399 // page is not, the pc and the faulting address might be slightly
400 // different - we still want to unguard the 2nd page in this case.
401 //
402 // 15 bytes seems to be a (very) safe value for max instruction size.
403 bool pc_is_near_addr =
404 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
405 bool instr_spans_page_boundary =
406 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
407 (intptr_t) page_size) > 0);
408
409 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
410 static volatile address last_addr =
411 (address) os::non_memory_address_word();
412
413 // In conservative mode, don't unguard unless the address is in the VM
414 if (addr != last_addr &&
415 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
416
417 // Unguard and retry
418 address page_start =
419 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
420 bool res = os::unguard_memory((char*) page_start, page_size);
421
422 if (PrintMiscellaneous && Verbose) {
423 char buf[256];
424 jio_snprintf(buf, sizeof(buf), "Execution protection violation "
425 "at " INTPTR_FORMAT
426 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
427 page_start, (res ? "success" : "failed"), errno);
428 tty->print_raw_cr(buf);
429 }
430 stub = pc;
431
432 // Set last_addr so if we fault again at the same address, we don't end
433 // up in an endless loop.
434 //
435 // There are two potential complications here. Two threads trapping at
436 // the same address at the same time could cause one of the threads to
437 // think it already unguarded, and abort the VM. Likely very rare.
438 //
439 // The other race involves two threads alternately trapping at
440 // different addresses and failing to unguard the page, resulting in
441 // an endless loop. This condition is probably even more unlikely than
442 // the first.
443 //
444 // Although both cases could be avoided by using locks or thread local
445 // last_addr, these solutions are unnecessary complication: this
446 // handler is a best-effort safety net, not a complete solution. It is
447 // disabled by default and should only be used as a workaround in case
448 // we missed any no-execute-unsafe VM code.
449
450 last_addr = addr;
451 }
452 }
453 }
454 #endif // !AMD64
455
456 if (stub != NULL) {
457 // save all thread context in case we need to restore it
458 if (thread != NULL) thread->set_saved_exception_pc(pc);
459
460 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub;
461 return true;
462 }
463
464 // signal-chaining
465 if (os::Linux::chained_handler(sig, info, ucVoid)) {
466 return true;
467 }
468
469 if (!abort_if_unrecognized) {
470 // caller wants another chance, so give it to him
471 return false;
472 }
473
474 if (pc == NULL && uc != NULL) {
475 pc = os::Linux::ucontext_get_pc(uc);
476 }
477
478 // unmask current signal
479 sigset_t newset;
480 sigemptyset(&newset);
481 sigaddset(&newset, sig);
482 sigprocmask(SIG_UNBLOCK, &newset, NULL);
483
484 VMError err(t, sig, pc, info, ucVoid);
485 err.report_and_die();
486
487 ShouldNotReachHere();
488 }
489
490 void os::Linux::init_thread_fpu_state(void) {
491 #ifndef AMD64
492 // set fpu to 53 bit precision
493 set_fpu_control_word(0x27f);
494 #endif // !AMD64
495 }
496
497 int os::Linux::get_fpu_control_word(void) {
498 #ifdef AMD64
499 return 0;
500 #else
501 int fpu_control;
502 _FPU_GETCW(fpu_control);
503 return fpu_control & 0xffff;
504 #endif // AMD64
505 }
506
507 void os::Linux::set_fpu_control_word(int fpu_control) {
508 #ifndef AMD64
509 _FPU_SETCW(fpu_control);
510 #endif // !AMD64
511 }
512
513 // Check that the linux kernel version is 2.4 or higher since earlier
514 // versions do not support SSE without patches.
515 bool os::supports_sse() {
516 #ifdef AMD64
517 return true;
518 #else
519 struct utsname uts;
520 if( uname(&uts) != 0 ) return false; // uname fails?
521 char *minor_string;
522 int major = strtol(uts.release,&minor_string,10);
523 int minor = strtol(minor_string+1,NULL,10);
524 bool result = (major > 2 || (major==2 && minor >= 4));
525 #ifndef PRODUCT
526 if (PrintMiscellaneous && Verbose) {
527 tty->print("OS version is %d.%d, which %s support SSE/SSE2\n",
528 major,minor, result ? "DOES" : "does NOT");
529 }
530 #endif
531 return result;
532 #endif // AMD64
533 }
534
535 bool os::is_allocatable(size_t bytes) {
536 #ifdef AMD64
537 // unused on amd64?
538 return true;
539 #else
540
541 if (bytes < 2 * G) {
542 return true;
543 }
544
545 char* addr = reserve_memory(bytes, NULL);
546
547 if (addr != NULL) {
548 release_memory(addr, bytes);
549 }
550
551 return addr != NULL;
552 #endif // AMD64
553 }
554
555 ////////////////////////////////////////////////////////////////////////////////
556 // thread stack
557
558 #ifdef AMD64
559 size_t os::Linux::min_stack_allowed = 64 * K;
560
561 // amd64: pthread on amd64 is always in floating stack mode
562 bool os::Linux::supports_variable_stack_size() { return true; }
563 #else
564 size_t os::Linux::min_stack_allowed = (48 DEBUG_ONLY(+4))*K;
565
566 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;})
567
568 // Test if pthread library can support variable thread stack size. LinuxThreads
569 // in fixed stack mode allocates 2M fixed slot for each thread. LinuxThreads
570 // in floating stack mode and NPTL support variable stack size.
571 bool os::Linux::supports_variable_stack_size() {
572 if (os::Linux::is_NPTL()) {
573 // NPTL, yes
574 return true;
575
576 } else {
577 // Note: We can't control default stack size when creating a thread.
578 // If we use non-default stack size (pthread_attr_setstacksize), both
579 // floating stack and non-floating stack LinuxThreads will return the
580 // same value. This makes it impossible to implement this function by
581 // detecting thread stack size directly.
582 //
583 // An alternative approach is to check %gs. Fixed-stack LinuxThreads
584 // do not use %gs, so its value is 0. Floating-stack LinuxThreads use
585 // %gs (either as LDT selector or GDT selector, depending on kernel)
586 // to access thread specific data.
587 //
588 // Note that %gs is a reserved glibc register since early 2001, so
589 // applications are not allowed to change its value (Ulrich Drepper from
590 // Redhat confirmed that all known offenders have been modified to use
591 // either %fs or TSD). In the worst case scenario, when VM is embedded in
592 // a native application that plays with %gs, we might see non-zero %gs
593 // even LinuxThreads is running in fixed stack mode. As the result, we'll
594 // return true and skip _thread_safety_check(), so we may not be able to
595 // detect stack-heap collisions. But otherwise it's harmless.
596 //
597 return (GET_GS() != 0);
598 }
599 }
600 #endif // AMD64
601
602 // return default stack size for thr_type
603 size_t os::Linux::default_stack_size(os::ThreadType thr_type) {
604 // default stack size (compiler thread needs larger stack)
605 #ifdef AMD64
606 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
607 #else
608 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
609 #endif // AMD64
610 return s;
611 }
612
613 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
614 // Creating guard page is very expensive. Java thread has HotSpot
615 // guard page, only enable glibc guard page for non-Java threads.
616 return (thr_type == java_thread ? 0 : page_size());
617 }
618
619 // Java thread:
620 //
621 // Low memory addresses
622 // +------------------------+
623 // | |\ JavaThread created by VM does not have glibc
624 // | glibc guard page | - guard, attached Java thread usually has
625 // | |/ 1 page glibc guard.
626 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
627 // | |\
628 // | HotSpot Guard Pages | - red and yellow pages
629 // | |/
630 // +------------------------+ JavaThread::stack_yellow_zone_base()
631 // | |\
632 // | Normal Stack | -
633 // | |/
634 // P2 +------------------------+ Thread::stack_base()
635 //
636 // Non-Java thread:
637 //
638 // Low memory addresses
639 // +------------------------+
640 // | |\
641 // | glibc guard page | - usually 1 page
642 // | |/
643 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
644 // | |\
645 // | Normal Stack | -
646 // | |/
647 // P2 +------------------------+ Thread::stack_base()
648 //
649 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
650 // pthread_attr_getstack()
651
652 static void current_stack_region(address * bottom, size_t * size) {
653 if (os::Linux::is_initial_thread()) {
654 // initial thread needs special handling because pthread_getattr_np()
655 // may return bogus value.
656 *bottom = os::Linux::initial_thread_stack_bottom();
657 *size = os::Linux::initial_thread_stack_size();
658 } else {
659 pthread_attr_t attr;
660
661 int rslt = pthread_getattr_np(pthread_self(), &attr);
662
663 // JVM needs to know exact stack location, abort if it fails
664 if (rslt != 0) {
665 if (rslt == ENOMEM) {
666 vm_exit_out_of_memory(0, "pthread_getattr_np");
667 } else {
668 fatal1("pthread_getattr_np failed with errno = %d", rslt);
669 }
670 }
671
672 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
673 fatal("Can not locate current stack attributes!");
674 }
675
676 pthread_attr_destroy(&attr);
677
678 }
679 assert(os::current_stack_pointer() >= *bottom &&
680 os::current_stack_pointer() < *bottom + *size, "just checking");
681 }
682
683 address os::current_stack_base() {
684 address bottom;
685 size_t size;
686 current_stack_region(&bottom, &size);
687 return (bottom + size);
688 }
689
690 size_t os::current_stack_size() {
691 // stack size includes normal stack and HotSpot guard pages
692 address bottom;
693 size_t size;
694 current_stack_region(&bottom, &size);
695 return size;
696 }
697
698 /////////////////////////////////////////////////////////////////////////////
699 // helper functions for fatal error handler
700
701 void os::print_context(outputStream *st, void *context) {
702 if (context == NULL) return;
703
704 ucontext_t *uc = (ucontext_t*)context;
705 st->print_cr("Registers:");
706 #ifdef AMD64
707 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
708 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
709 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
710 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
711 st->cr();
712 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
713 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
714 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
715 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
716 st->cr();
717 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
718 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
719 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
720 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
721 st->cr();
722 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
723 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
724 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
725 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
726 st->cr();
727 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
728 st->print(", EFL=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]);
729 st->print(", CSGSFS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_CSGSFS]);
730 st->print(", ERR=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ERR]);
731 st->cr();
732 st->print(" TRAPNO=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_TRAPNO]);
733 #else
734 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EAX]);
735 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBX]);
736 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ECX]);
737 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDX]);
738 st->cr();
739 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_UESP]);
740 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBP]);
741 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ESI]);
742 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDI]);
743 st->cr();
744 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EIP]);
745 st->print(", CR2=" INTPTR_FORMAT, uc->uc_mcontext.cr2);
746 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]);
747 #endif // AMD64
748 st->cr();
749 st->cr();
750
751 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
752 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
753 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
754 st->cr();
755
756 // Note: it may be unsafe to inspect memory near pc. For example, pc may
757 // point to garbage if entry point in an nmethod is corrupted. Leave
758 // this at the end, and hope for the best.
759 address pc = os::Linux::ucontext_get_pc(uc);
760 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
761 print_hex_dump(st, pc - 16, pc + 16, sizeof(char));
762 }
763
764 void os::setup_fpu() {
765 #ifndef AMD64
766 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
767 __asm__ volatile ( "fldcw (%0)" :
768 : "r" (fpu_cntrl) : "memory");
769 #endif // !AMD64
770 }