Mercurial > hg > truffle
comparison src/os_cpu/linux_x86/vm/os_linux_x86.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | e195fe4c40c7 485d403e94e1 |
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1 /* | |
2 * Copyright 1999-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any 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 register void *esp __asm__ (SPELL_REG_SP); | |
66 return (address) esp; | |
67 } | |
68 | |
69 char* os::non_memory_address_word() { | |
70 // Must never look like an address returned by reserve_memory, | |
71 // even in its subfields (as defined by the CPU immediate fields, | |
72 // if the CPU splits constants across multiple instructions). | |
73 | |
74 return (char*) -1; | |
75 } | |
76 | |
77 void os::initialize_thread() { | |
78 // Nothing to do. | |
79 } | |
80 | |
81 address os::Linux::ucontext_get_pc(ucontext_t * uc) { | |
82 return (address)uc->uc_mcontext.gregs[REG_PC]; | |
83 } | |
84 | |
85 intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) { | |
86 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP]; | |
87 } | |
88 | |
89 intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) { | |
90 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP]; | |
91 } | |
92 | |
93 // For Forte Analyzer AsyncGetCallTrace profiling support - thread | |
94 // is currently interrupted by SIGPROF. | |
95 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal | |
96 // frames. Currently we don't do that on Linux, so it's the same as | |
97 // os::fetch_frame_from_context(). | |
98 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread, | |
99 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { | |
100 | |
101 assert(thread != NULL, "just checking"); | |
102 assert(ret_sp != NULL, "just checking"); | |
103 assert(ret_fp != NULL, "just checking"); | |
104 | |
105 return os::fetch_frame_from_context(uc, ret_sp, ret_fp); | |
106 } | |
107 | |
108 ExtendedPC os::fetch_frame_from_context(void* ucVoid, | |
109 intptr_t** ret_sp, intptr_t** ret_fp) { | |
110 | |
111 ExtendedPC epc; | |
112 ucontext_t* uc = (ucontext_t*)ucVoid; | |
113 | |
114 if (uc != NULL) { | |
115 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc)); | |
116 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc); | |
117 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc); | |
118 } else { | |
119 // construct empty ExtendedPC for return value checking | |
120 epc = ExtendedPC(NULL); | |
121 if (ret_sp) *ret_sp = (intptr_t *)NULL; | |
122 if (ret_fp) *ret_fp = (intptr_t *)NULL; | |
123 } | |
124 | |
125 return epc; | |
126 } | |
127 | |
128 frame os::fetch_frame_from_context(void* ucVoid) { | |
129 intptr_t* sp; | |
130 intptr_t* fp; | |
131 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); | |
132 return frame(sp, fp, epc.pc()); | |
133 } | |
134 | |
135 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get | |
136 // turned off by -fomit-frame-pointer, | |
137 frame os::get_sender_for_C_frame(frame* fr) { | |
138 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); | |
139 } | |
140 | |
141 intptr_t* _get_previous_fp() { | |
142 register intptr_t **ebp __asm__ (SPELL_REG_FP); | |
143 return (intptr_t*) *ebp; // we want what it points to. | |
144 } | |
145 | |
146 | |
147 frame os::current_frame() { | |
148 intptr_t* fp = _get_previous_fp(); | |
149 frame myframe((intptr_t*)os::current_stack_pointer(), | |
150 (intptr_t*)fp, | |
151 CAST_FROM_FN_PTR(address, os::current_frame)); | |
152 if (os::is_first_C_frame(&myframe)) { | |
153 // stack is not walkable | |
154 return frame(NULL, NULL, NULL); | |
155 } else { | |
156 return os::get_sender_for_C_frame(&myframe); | |
157 } | |
158 } | |
159 | |
160 | |
161 // Utility functions | |
162 | |
163 julong os::allocatable_physical_memory(julong size) { | |
164 #ifdef AMD64 | |
165 return size; | |
166 #else | |
167 julong result = MIN2(size, (julong)3800*M); | |
168 if (!is_allocatable(result)) { | |
169 // See comments under solaris for alignment considerations | |
170 julong reasonable_size = (julong)2*G - 2 * os::vm_page_size(); | |
171 result = MIN2(size, reasonable_size); | |
172 } | |
173 return result; | |
174 #endif // AMD64 | |
175 } | |
176 | |
177 // From IA32 System Programming Guide | |
178 enum { | |
179 trap_page_fault = 0xE | |
180 }; | |
181 | |
182 extern "C" void Fetch32PFI () ; | |
183 extern "C" void Fetch32Resume () ; | |
184 #ifdef AMD64 | |
185 extern "C" void FetchNPFI () ; | |
186 extern "C" void FetchNResume () ; | |
187 #endif // AMD64 | |
188 | |
189 extern "C" int | |
190 JVM_handle_linux_signal(int sig, | |
191 siginfo_t* info, | |
192 void* ucVoid, | |
193 int abort_if_unrecognized) { | |
194 ucontext_t* uc = (ucontext_t*) ucVoid; | |
195 | |
196 Thread* t = ThreadLocalStorage::get_thread_slow(); | |
197 | |
198 SignalHandlerMark shm(t); | |
199 | |
200 // Note: it's not uncommon that JNI code uses signal/sigset to install | |
201 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, | |
202 // or have a SIGILL handler when detecting CPU type). When that happens, | |
203 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To | |
204 // avoid unnecessary crash when libjsig is not preloaded, try handle signals | |
205 // that do not require siginfo/ucontext first. | |
206 | |
207 if (sig == SIGPIPE || sig == SIGXFSZ) { | |
208 // allow chained handler to go first | |
209 if (os::Linux::chained_handler(sig, info, ucVoid)) { | |
210 return true; | |
211 } else { | |
212 if (PrintMiscellaneous && (WizardMode || Verbose)) { | |
213 char buf[64]; | |
214 warning("Ignoring %s - see bugs 4229104 or 646499219", | |
215 os::exception_name(sig, buf, sizeof(buf))); | |
216 } | |
217 return true; | |
218 } | |
219 } | |
220 | |
221 JavaThread* thread = NULL; | |
222 VMThread* vmthread = NULL; | |
223 if (os::Linux::signal_handlers_are_installed) { | |
224 if (t != NULL ){ | |
225 if(t->is_Java_thread()) { | |
226 thread = (JavaThread*)t; | |
227 } | |
228 else if(t->is_VM_thread()){ | |
229 vmthread = (VMThread *)t; | |
230 } | |
231 } | |
232 } | |
233 /* | |
234 NOTE: does not seem to work on linux. | |
235 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { | |
236 // can't decode this kind of signal | |
237 info = NULL; | |
238 } else { | |
239 assert(sig == info->si_signo, "bad siginfo"); | |
240 } | |
241 */ | |
242 // decide if this trap can be handled by a stub | |
243 address stub = NULL; | |
244 | |
245 address pc = NULL; | |
246 | |
247 //%note os_trap_1 | |
248 if (info != NULL && uc != NULL && thread != NULL) { | |
249 pc = (address) os::Linux::ucontext_get_pc(uc); | |
250 | |
251 if (pc == (address) Fetch32PFI) { | |
252 uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ; | |
253 return 1 ; | |
254 } | |
255 #ifdef AMD64 | |
256 if (pc == (address) FetchNPFI) { | |
257 uc->uc_mcontext.gregs[REG_PC] = intptr_t (FetchNResume) ; | |
258 return 1 ; | |
259 } | |
260 #endif // AMD64 | |
261 | |
262 // Handle ALL stack overflow variations here | |
263 if (sig == SIGSEGV) { | |
264 address addr = (address) info->si_addr; | |
265 | |
266 // check if fault address is within thread stack | |
267 if (addr < thread->stack_base() && | |
268 addr >= thread->stack_base() - thread->stack_size()) { | |
269 // stack overflow | |
270 if (thread->in_stack_yellow_zone(addr)) { | |
271 thread->disable_stack_yellow_zone(); | |
272 if (thread->thread_state() == _thread_in_Java) { | |
273 // Throw a stack overflow exception. Guard pages will be reenabled | |
274 // while unwinding the stack. | |
275 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); | |
276 } else { | |
277 // Thread was in the vm or native code. Return and try to finish. | |
278 return 1; | |
279 } | |
280 } else if (thread->in_stack_red_zone(addr)) { | |
281 // Fatal red zone violation. Disable the guard pages and fall through | |
282 // to handle_unexpected_exception way down below. | |
283 thread->disable_stack_red_zone(); | |
284 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); | |
285 } else { | |
286 // Accessing stack address below sp may cause SEGV if current | |
287 // thread has MAP_GROWSDOWN stack. This should only happen when | |
288 // current thread was created by user code with MAP_GROWSDOWN flag | |
289 // and then attached to VM. See notes in os_linux.cpp. | |
290 if (thread->osthread()->expanding_stack() == 0) { | |
291 thread->osthread()->set_expanding_stack(); | |
292 if (os::Linux::manually_expand_stack(thread, addr)) { | |
293 thread->osthread()->clear_expanding_stack(); | |
294 return 1; | |
295 } | |
296 thread->osthread()->clear_expanding_stack(); | |
297 } else { | |
298 fatal("recursive segv. expanding stack."); | |
299 } | |
300 } | |
301 } | |
302 } | |
303 | |
304 if (thread->thread_state() == _thread_in_Java) { | |
305 // Java thread running in Java code => find exception handler if any | |
306 // a fault inside compiled code, the interpreter, or a stub | |
307 | |
308 if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) { | |
309 stub = SharedRuntime::get_poll_stub(pc); | |
310 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { | |
311 // BugId 4454115: A read from a MappedByteBuffer can fault | |
312 // here if the underlying file has been truncated. | |
313 // Do not crash the VM in such a case. | |
314 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); | |
315 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL; | |
316 if (nm != NULL && nm->has_unsafe_access()) { | |
317 stub = StubRoutines::handler_for_unsafe_access(); | |
318 } | |
319 } | |
320 else | |
321 | |
322 #ifdef AMD64 | |
323 if (sig == SIGFPE && | |
324 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { | |
325 stub = | |
326 SharedRuntime:: | |
327 continuation_for_implicit_exception(thread, | |
328 pc, | |
329 SharedRuntime:: | |
330 IMPLICIT_DIVIDE_BY_ZERO); | |
331 #else | |
332 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { | |
333 // HACK: si_code does not work on linux 2.2.12-20!!! | |
334 int op = pc[0]; | |
335 if (op == 0xDB) { | |
336 // FIST | |
337 // TODO: The encoding of D2I in i486.ad can cause an exception | |
338 // prior to the fist instruction if there was an invalid operation | |
339 // pending. We want to dismiss that exception. From the win_32 | |
340 // side it also seems that if it really was the fist causing | |
341 // the exception that we do the d2i by hand with different | |
342 // rounding. Seems kind of weird. | |
343 // NOTE: that we take the exception at the NEXT floating point instruction. | |
344 assert(pc[0] == 0xDB, "not a FIST opcode"); | |
345 assert(pc[1] == 0x14, "not a FIST opcode"); | |
346 assert(pc[2] == 0x24, "not a FIST opcode"); | |
347 return true; | |
348 } else if (op == 0xF7) { | |
349 // IDIV | |
350 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); | |
351 } else { | |
352 // TODO: handle more cases if we are using other x86 instructions | |
353 // that can generate SIGFPE signal on linux. | |
354 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); | |
355 fatal("please update this code."); | |
356 } | |
357 #endif // AMD64 | |
358 } else if (sig == SIGSEGV && | |
359 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { | |
360 // Determination of interpreter/vtable stub/compiled code null exception | |
361 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); | |
362 } | |
363 } else if (thread->thread_state() == _thread_in_vm && | |
364 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ | |
365 thread->doing_unsafe_access()) { | |
366 stub = StubRoutines::handler_for_unsafe_access(); | |
367 } | |
368 | |
369 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in | |
370 // and the heap gets shrunk before the field access. | |
371 if ((sig == SIGSEGV) || (sig == SIGBUS)) { | |
372 address addr = JNI_FastGetField::find_slowcase_pc(pc); | |
373 if (addr != (address)-1) { | |
374 stub = addr; | |
375 } | |
376 } | |
377 | |
378 // Check to see if we caught the safepoint code in the | |
379 // process of write protecting the memory serialization page. | |
380 // It write enables the page immediately after protecting it | |
381 // so we can just return to retry the write. | |
382 if ((sig == SIGSEGV) && | |
383 os::is_memory_serialize_page(thread, (address) info->si_addr)) { | |
384 // Block current thread until the memory serialize page permission restored. | |
385 os::block_on_serialize_page_trap(); | |
386 return true; | |
387 } | |
388 } | |
389 | |
390 #ifndef AMD64 | |
391 // Execution protection violation | |
392 // | |
393 // This should be kept as the last step in the triage. We don't | |
394 // have a dedicated trap number for a no-execute fault, so be | |
395 // conservative and allow other handlers the first shot. | |
396 // | |
397 // Note: We don't test that info->si_code == SEGV_ACCERR here. | |
398 // this si_code is so generic that it is almost meaningless; and | |
399 // the si_code for this condition may change in the future. | |
400 // Furthermore, a false-positive should be harmless. | |
401 if (UnguardOnExecutionViolation > 0 && | |
402 (sig == SIGSEGV || sig == SIGBUS) && | |
403 uc->uc_mcontext.gregs[REG_TRAPNO] == trap_page_fault) { | |
404 int page_size = os::vm_page_size(); | |
405 address addr = (address) info->si_addr; | |
406 address pc = os::Linux::ucontext_get_pc(uc); | |
407 // Make sure the pc and the faulting address are sane. | |
408 // | |
409 // If an instruction spans a page boundary, and the page containing | |
410 // the beginning of the instruction is executable but the following | |
411 // page is not, the pc and the faulting address might be slightly | |
412 // different - we still want to unguard the 2nd page in this case. | |
413 // | |
414 // 15 bytes seems to be a (very) safe value for max instruction size. | |
415 bool pc_is_near_addr = | |
416 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); | |
417 bool instr_spans_page_boundary = | |
418 (align_size_down((intptr_t) pc ^ (intptr_t) addr, | |
419 (intptr_t) page_size) > 0); | |
420 | |
421 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { | |
422 static volatile address last_addr = | |
423 (address) os::non_memory_address_word(); | |
424 | |
425 // In conservative mode, don't unguard unless the address is in the VM | |
426 if (addr != last_addr && | |
427 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { | |
428 | |
429 // Unguard and retry | |
430 address page_start = | |
431 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); | |
432 bool res = os::unguard_memory((char*) page_start, page_size); | |
433 | |
434 if (PrintMiscellaneous && Verbose) { | |
435 char buf[256]; | |
436 jio_snprintf(buf, sizeof(buf), "Execution protection violation " | |
437 "at " INTPTR_FORMAT | |
438 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, | |
439 page_start, (res ? "success" : "failed"), errno); | |
440 tty->print_raw_cr(buf); | |
441 } | |
442 stub = pc; | |
443 | |
444 // Set last_addr so if we fault again at the same address, we don't end | |
445 // up in an endless loop. | |
446 // | |
447 // There are two potential complications here. Two threads trapping at | |
448 // the same address at the same time could cause one of the threads to | |
449 // think it already unguarded, and abort the VM. Likely very rare. | |
450 // | |
451 // The other race involves two threads alternately trapping at | |
452 // different addresses and failing to unguard the page, resulting in | |
453 // an endless loop. This condition is probably even more unlikely than | |
454 // the first. | |
455 // | |
456 // Although both cases could be avoided by using locks or thread local | |
457 // last_addr, these solutions are unnecessary complication: this | |
458 // handler is a best-effort safety net, not a complete solution. It is | |
459 // disabled by default and should only be used as a workaround in case | |
460 // we missed any no-execute-unsafe VM code. | |
461 | |
462 last_addr = addr; | |
463 } | |
464 } | |
465 } | |
466 #endif // !AMD64 | |
467 | |
468 if (stub != NULL) { | |
469 // save all thread context in case we need to restore it | |
470 if (thread != NULL) thread->set_saved_exception_pc(pc); | |
471 | |
472 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub; | |
473 return true; | |
474 } | |
475 | |
476 // signal-chaining | |
477 if (os::Linux::chained_handler(sig, info, ucVoid)) { | |
478 return true; | |
479 } | |
480 | |
481 if (!abort_if_unrecognized) { | |
482 // caller wants another chance, so give it to him | |
483 return false; | |
484 } | |
485 | |
486 if (pc == NULL && uc != NULL) { | |
487 pc = os::Linux::ucontext_get_pc(uc); | |
488 } | |
489 | |
490 // unmask current signal | |
491 sigset_t newset; | |
492 sigemptyset(&newset); | |
493 sigaddset(&newset, sig); | |
494 sigprocmask(SIG_UNBLOCK, &newset, NULL); | |
495 | |
496 VMError err(t, sig, pc, info, ucVoid); | |
497 err.report_and_die(); | |
498 | |
499 ShouldNotReachHere(); | |
500 } | |
501 | |
502 void os::Linux::init_thread_fpu_state(void) { | |
503 #ifndef AMD64 | |
504 // set fpu to 53 bit precision | |
505 set_fpu_control_word(0x27f); | |
506 #endif // !AMD64 | |
507 } | |
508 | |
509 int os::Linux::get_fpu_control_word(void) { | |
510 #ifdef AMD64 | |
511 return 0; | |
512 #else | |
513 int fpu_control; | |
514 _FPU_GETCW(fpu_control); | |
515 return fpu_control & 0xffff; | |
516 #endif // AMD64 | |
517 } | |
518 | |
519 void os::Linux::set_fpu_control_word(int fpu_control) { | |
520 #ifndef AMD64 | |
521 _FPU_SETCW(fpu_control); | |
522 #endif // !AMD64 | |
523 } | |
524 | |
525 // Check that the linux kernel version is 2.4 or higher since earlier | |
526 // versions do not support SSE without patches. | |
527 bool os::supports_sse() { | |
528 #ifdef AMD64 | |
529 return true; | |
530 #else | |
531 struct utsname uts; | |
532 if( uname(&uts) != 0 ) return false; // uname fails? | |
533 char *minor_string; | |
534 int major = strtol(uts.release,&minor_string,10); | |
535 int minor = strtol(minor_string+1,NULL,10); | |
536 bool result = (major > 2 || (major==2 && minor >= 4)); | |
537 #ifndef PRODUCT | |
538 if (PrintMiscellaneous && Verbose) { | |
539 tty->print("OS version is %d.%d, which %s support SSE/SSE2\n", | |
540 major,minor, result ? "DOES" : "does NOT"); | |
541 } | |
542 #endif | |
543 return result; | |
544 #endif // AMD64 | |
545 } | |
546 | |
547 bool os::is_allocatable(size_t bytes) { | |
548 #ifdef AMD64 | |
549 // unused on amd64? | |
550 return true; | |
551 #else | |
552 | |
553 if (bytes < 2 * G) { | |
554 return true; | |
555 } | |
556 | |
557 char* addr = reserve_memory(bytes, NULL); | |
558 | |
559 if (addr != NULL) { | |
560 release_memory(addr, bytes); | |
561 } | |
562 | |
563 return addr != NULL; | |
564 #endif // AMD64 | |
565 } | |
566 | |
567 //////////////////////////////////////////////////////////////////////////////// | |
568 // thread stack | |
569 | |
570 #ifdef AMD64 | |
571 size_t os::Linux::min_stack_allowed = 64 * K; | |
572 | |
573 // amd64: pthread on amd64 is always in floating stack mode | |
574 bool os::Linux::supports_variable_stack_size() { return true; } | |
575 #else | |
576 size_t os::Linux::min_stack_allowed = (48 DEBUG_ONLY(+4))*K; | |
577 | |
578 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) | |
579 | |
580 // Test if pthread library can support variable thread stack size. LinuxThreads | |
581 // in fixed stack mode allocates 2M fixed slot for each thread. LinuxThreads | |
582 // in floating stack mode and NPTL support variable stack size. | |
583 bool os::Linux::supports_variable_stack_size() { | |
584 if (os::Linux::is_NPTL()) { | |
585 // NPTL, yes | |
586 return true; | |
587 | |
588 } else { | |
589 // Note: We can't control default stack size when creating a thread. | |
590 // If we use non-default stack size (pthread_attr_setstacksize), both | |
591 // floating stack and non-floating stack LinuxThreads will return the | |
592 // same value. This makes it impossible to implement this function by | |
593 // detecting thread stack size directly. | |
594 // | |
595 // An alternative approach is to check %gs. Fixed-stack LinuxThreads | |
596 // do not use %gs, so its value is 0. Floating-stack LinuxThreads use | |
597 // %gs (either as LDT selector or GDT selector, depending on kernel) | |
598 // to access thread specific data. | |
599 // | |
600 // Note that %gs is a reserved glibc register since early 2001, so | |
601 // applications are not allowed to change its value (Ulrich Drepper from | |
602 // Redhat confirmed that all known offenders have been modified to use | |
603 // either %fs or TSD). In the worst case scenario, when VM is embedded in | |
604 // a native application that plays with %gs, we might see non-zero %gs | |
605 // even LinuxThreads is running in fixed stack mode. As the result, we'll | |
606 // return true and skip _thread_safety_check(), so we may not be able to | |
607 // detect stack-heap collisions. But otherwise it's harmless. | |
608 // | |
609 return (GET_GS() != 0); | |
610 } | |
611 } | |
612 #endif // AMD64 | |
613 | |
614 // return default stack size for thr_type | |
615 size_t os::Linux::default_stack_size(os::ThreadType thr_type) { | |
616 // default stack size (compiler thread needs larger stack) | |
617 #ifdef AMD64 | |
618 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); | |
619 #else | |
620 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); | |
621 #endif // AMD64 | |
622 return s; | |
623 } | |
624 | |
625 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { | |
626 // Creating guard page is very expensive. Java thread has HotSpot | |
627 // guard page, only enable glibc guard page for non-Java threads. | |
628 return (thr_type == java_thread ? 0 : page_size()); | |
629 } | |
630 | |
631 // Java thread: | |
632 // | |
633 // Low memory addresses | |
634 // +------------------------+ | |
635 // | |\ JavaThread created by VM does not have glibc | |
636 // | glibc guard page | - guard, attached Java thread usually has | |
637 // | |/ 1 page glibc guard. | |
638 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() | |
639 // | |\ | |
640 // | HotSpot Guard Pages | - red and yellow pages | |
641 // | |/ | |
642 // +------------------------+ JavaThread::stack_yellow_zone_base() | |
643 // | |\ | |
644 // | Normal Stack | - | |
645 // | |/ | |
646 // P2 +------------------------+ Thread::stack_base() | |
647 // | |
648 // Non-Java thread: | |
649 // | |
650 // Low memory addresses | |
651 // +------------------------+ | |
652 // | |\ | |
653 // | glibc guard page | - usually 1 page | |
654 // | |/ | |
655 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() | |
656 // | |\ | |
657 // | Normal Stack | - | |
658 // | |/ | |
659 // P2 +------------------------+ Thread::stack_base() | |
660 // | |
661 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from | |
662 // pthread_attr_getstack() | |
663 | |
664 static void current_stack_region(address * bottom, size_t * size) { | |
665 if (os::Linux::is_initial_thread()) { | |
666 // initial thread needs special handling because pthread_getattr_np() | |
667 // may return bogus value. | |
668 *bottom = os::Linux::initial_thread_stack_bottom(); | |
669 *size = os::Linux::initial_thread_stack_size(); | |
670 } else { | |
671 pthread_attr_t attr; | |
672 | |
673 int rslt = pthread_getattr_np(pthread_self(), &attr); | |
674 | |
675 // JVM needs to know exact stack location, abort if it fails | |
676 if (rslt != 0) { | |
677 if (rslt == ENOMEM) { | |
678 vm_exit_out_of_memory(0, "pthread_getattr_np"); | |
679 } else { | |
680 fatal1("pthread_getattr_np failed with errno = %d", rslt); | |
681 } | |
682 } | |
683 | |
684 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { | |
685 fatal("Can not locate current stack attributes!"); | |
686 } | |
687 | |
688 pthread_attr_destroy(&attr); | |
689 | |
690 } | |
691 assert(os::current_stack_pointer() >= *bottom && | |
692 os::current_stack_pointer() < *bottom + *size, "just checking"); | |
693 } | |
694 | |
695 address os::current_stack_base() { | |
696 address bottom; | |
697 size_t size; | |
698 current_stack_region(&bottom, &size); | |
699 return (bottom + size); | |
700 } | |
701 | |
702 size_t os::current_stack_size() { | |
703 // stack size includes normal stack and HotSpot guard pages | |
704 address bottom; | |
705 size_t size; | |
706 current_stack_region(&bottom, &size); | |
707 return size; | |
708 } | |
709 | |
710 ///////////////////////////////////////////////////////////////////////////// | |
711 // helper functions for fatal error handler | |
712 | |
713 void os::print_context(outputStream *st, void *context) { | |
714 if (context == NULL) return; | |
715 | |
716 ucontext_t *uc = (ucontext_t*)context; | |
717 st->print_cr("Registers:"); | |
718 #ifdef AMD64 | |
719 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]); | |
720 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]); | |
721 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]); | |
722 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]); | |
723 st->cr(); | |
724 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]); | |
725 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]); | |
726 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]); | |
727 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]); | |
728 st->cr(); | |
729 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]); | |
730 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]); | |
731 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]); | |
732 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]); | |
733 st->cr(); | |
734 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]); | |
735 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]); | |
736 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]); | |
737 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]); | |
738 st->cr(); | |
739 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]); | |
740 st->print(", EFL=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]); | |
741 st->print(", CSGSFS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_CSGSFS]); | |
742 st->print(", ERR=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ERR]); | |
743 st->cr(); | |
744 st->print(" TRAPNO=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_TRAPNO]); | |
745 #else | |
746 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EAX]); | |
747 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBX]); | |
748 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ECX]); | |
749 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDX]); | |
750 st->cr(); | |
751 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_UESP]); | |
752 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBP]); | |
753 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ESI]); | |
754 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDI]); | |
755 st->cr(); | |
756 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EIP]); | |
757 st->print(", CR2=" INTPTR_FORMAT, uc->uc_mcontext.cr2); | |
758 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]); | |
759 #endif // AMD64 | |
760 st->cr(); | |
761 st->cr(); | |
762 | |
763 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc); | |
764 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); | |
765 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); | |
766 st->cr(); | |
767 | |
768 // Note: it may be unsafe to inspect memory near pc. For example, pc may | |
769 // point to garbage if entry point in an nmethod is corrupted. Leave | |
770 // this at the end, and hope for the best. | |
771 address pc = os::Linux::ucontext_get_pc(uc); | |
772 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); | |
773 print_hex_dump(st, pc - 16, pc + 16, sizeof(char)); | |
774 } | |
775 | |
776 void os::setup_fpu() { | |
777 #ifndef AMD64 | |
778 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); | |
779 __asm__ volatile ( "fldcw (%0)" : | |
780 : "r" (fpu_cntrl) : "memory"); | |
781 #endif // !AMD64 | |
782 } |