Mercurial > hg > graal-compiler
annotate src/os_cpu/linux_x86/vm/os_linux_x86.cpp @ 20615:ef6b27d844cc
8058715: stability issues when being launched as an embedded JVM via JNI
Summary: Use mmap call without MAP_FIXED so we avoid corrupting already allocated memory
Reviewed-by: coleenp, dsimms
author | dbuck |
---|---|
date | Thu, 06 Nov 2014 02:34:01 -0800 |
parents | 78bbf4d43a14 |
children | 7848fc12602b |
rev | line source |
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0 | 1 /* |
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2 * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved. |
0 | 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 * | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 // no precompiled headers |
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26 #include "asm/macroAssembler.hpp" |
1972 | 27 #include "classfile/classLoader.hpp" |
28 #include "classfile/systemDictionary.hpp" | |
29 #include "classfile/vmSymbols.hpp" | |
30 #include "code/icBuffer.hpp" | |
31 #include "code/vtableStubs.hpp" | |
32 #include "interpreter/interpreter.hpp" | |
33 #include "jvm_linux.h" | |
34 #include "memory/allocation.inline.hpp" | |
35 #include "mutex_linux.inline.hpp" | |
36 #include "os_share_linux.hpp" | |
37 #include "prims/jniFastGetField.hpp" | |
38 #include "prims/jvm.h" | |
39 #include "prims/jvm_misc.hpp" | |
40 #include "runtime/arguments.hpp" | |
41 #include "runtime/extendedPC.hpp" | |
42 #include "runtime/frame.inline.hpp" | |
43 #include "runtime/interfaceSupport.hpp" | |
44 #include "runtime/java.hpp" | |
45 #include "runtime/javaCalls.hpp" | |
46 #include "runtime/mutexLocker.hpp" | |
47 #include "runtime/osThread.hpp" | |
48 #include "runtime/sharedRuntime.hpp" | |
49 #include "runtime/stubRoutines.hpp" | |
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50 #include "runtime/thread.inline.hpp" |
1972 | 51 #include "runtime/timer.hpp" |
52 #include "utilities/events.hpp" | |
53 #include "utilities/vmError.hpp" | |
0 | 54 |
55 // put OS-includes here | |
56 # include <sys/types.h> | |
57 # include <sys/mman.h> | |
58 # include <pthread.h> | |
59 # include <signal.h> | |
60 # include <errno.h> | |
61 # include <dlfcn.h> | |
62 # include <stdlib.h> | |
63 # include <stdio.h> | |
64 # include <unistd.h> | |
65 # include <sys/resource.h> | |
66 # include <pthread.h> | |
67 # include <sys/stat.h> | |
68 # include <sys/time.h> | |
69 # include <sys/utsname.h> | |
70 # include <sys/socket.h> | |
71 # include <sys/wait.h> | |
72 # include <pwd.h> | |
73 # include <poll.h> | |
74 # include <ucontext.h> | |
75 # include <fpu_control.h> | |
76 | |
77 #ifdef AMD64 | |
78 #define REG_SP REG_RSP | |
79 #define REG_PC REG_RIP | |
80 #define REG_FP REG_RBP | |
81 #define SPELL_REG_SP "rsp" | |
82 #define SPELL_REG_FP "rbp" | |
83 #else | |
84 #define REG_SP REG_UESP | |
85 #define REG_PC REG_EIP | |
86 #define REG_FP REG_EBP | |
87 #define SPELL_REG_SP "esp" | |
88 #define SPELL_REG_FP "ebp" | |
89 #endif // AMD64 | |
90 | |
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91 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC |
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92 |
0 | 93 address os::current_stack_pointer() { |
50
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94 #ifdef SPARC_WORKS |
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95 register void *esp; |
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96 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); |
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97 return (address) ((char*)esp + sizeof(long)*2); |
10398 | 98 #elif defined(__clang__) |
99 intptr_t* esp; | |
100 __asm__ __volatile__ ("mov %%"SPELL_REG_SP", %0":"=r"(esp):); | |
101 return (address) esp; | |
50
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102 #else |
0 | 103 register void *esp __asm__ (SPELL_REG_SP); |
104 return (address) esp; | |
50
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105 #endif |
0 | 106 } |
107 | |
108 char* os::non_memory_address_word() { | |
109 // Must never look like an address returned by reserve_memory, | |
110 // even in its subfields (as defined by the CPU immediate fields, | |
111 // if the CPU splits constants across multiple instructions). | |
112 | |
113 return (char*) -1; | |
114 } | |
115 | |
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116 void os::initialize_thread(Thread* thr) { |
0 | 117 // Nothing to do. |
118 } | |
119 | |
120 address os::Linux::ucontext_get_pc(ucontext_t * uc) { | |
121 return (address)uc->uc_mcontext.gregs[REG_PC]; | |
122 } | |
123 | |
124 intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) { | |
125 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP]; | |
126 } | |
127 | |
128 intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) { | |
129 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP]; | |
130 } | |
131 | |
132 // For Forte Analyzer AsyncGetCallTrace profiling support - thread | |
133 // is currently interrupted by SIGPROF. | |
134 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal | |
135 // frames. Currently we don't do that on Linux, so it's the same as | |
136 // os::fetch_frame_from_context(). | |
137 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread, | |
138 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { | |
139 | |
140 assert(thread != NULL, "just checking"); | |
141 assert(ret_sp != NULL, "just checking"); | |
142 assert(ret_fp != NULL, "just checking"); | |
143 | |
144 return os::fetch_frame_from_context(uc, ret_sp, ret_fp); | |
145 } | |
146 | |
147 ExtendedPC os::fetch_frame_from_context(void* ucVoid, | |
148 intptr_t** ret_sp, intptr_t** ret_fp) { | |
149 | |
150 ExtendedPC epc; | |
151 ucontext_t* uc = (ucontext_t*)ucVoid; | |
152 | |
153 if (uc != NULL) { | |
154 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc)); | |
155 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc); | |
156 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc); | |
157 } else { | |
158 // construct empty ExtendedPC for return value checking | |
159 epc = ExtendedPC(NULL); | |
160 if (ret_sp) *ret_sp = (intptr_t *)NULL; | |
161 if (ret_fp) *ret_fp = (intptr_t *)NULL; | |
162 } | |
163 | |
164 return epc; | |
165 } | |
166 | |
167 frame os::fetch_frame_from_context(void* ucVoid) { | |
168 intptr_t* sp; | |
169 intptr_t* fp; | |
170 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); | |
171 return frame(sp, fp, epc.pc()); | |
172 } | |
173 | |
174 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get | |
175 // turned off by -fomit-frame-pointer, | |
176 frame os::get_sender_for_C_frame(frame* fr) { | |
177 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); | |
178 } | |
179 | |
180 intptr_t* _get_previous_fp() { | |
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181 #ifdef SPARC_WORKS |
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182 register intptr_t **ebp; |
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183 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp)); |
10398 | 184 #elif defined(__clang__) |
185 intptr_t **ebp; | |
186 __asm__ __volatile__ ("mov %%"SPELL_REG_FP", %0":"=r"(ebp):); | |
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187 #else |
0 | 188 register intptr_t **ebp __asm__ (SPELL_REG_FP); |
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189 #endif |
0 | 190 return (intptr_t*) *ebp; // we want what it points to. |
191 } | |
192 | |
193 | |
194 frame os::current_frame() { | |
195 intptr_t* fp = _get_previous_fp(); | |
196 frame myframe((intptr_t*)os::current_stack_pointer(), | |
197 (intptr_t*)fp, | |
198 CAST_FROM_FN_PTR(address, os::current_frame)); | |
199 if (os::is_first_C_frame(&myframe)) { | |
200 // stack is not walkable | |
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201 return frame(); |
0 | 202 } else { |
203 return os::get_sender_for_C_frame(&myframe); | |
204 } | |
205 } | |
206 | |
207 // Utility functions | |
208 | |
209 // From IA32 System Programming Guide | |
210 enum { | |
211 trap_page_fault = 0xE | |
212 }; | |
213 | |
2191 | 214 extern "C" JNIEXPORT int |
0 | 215 JVM_handle_linux_signal(int sig, |
216 siginfo_t* info, | |
217 void* ucVoid, | |
218 int abort_if_unrecognized) { | |
219 ucontext_t* uc = (ucontext_t*) ucVoid; | |
220 | |
221 Thread* t = ThreadLocalStorage::get_thread_slow(); | |
222 | |
11151 | 223 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away |
224 // (no destructors can be run) | |
225 os::WatcherThreadCrashProtection::check_crash_protection(sig, t); | |
226 | |
0 | 227 SignalHandlerMark shm(t); |
228 | |
229 // Note: it's not uncommon that JNI code uses signal/sigset to install | |
230 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, | |
231 // or have a SIGILL handler when detecting CPU type). When that happens, | |
232 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To | |
233 // avoid unnecessary crash when libjsig is not preloaded, try handle signals | |
234 // that do not require siginfo/ucontext first. | |
235 | |
236 if (sig == SIGPIPE || sig == SIGXFSZ) { | |
237 // allow chained handler to go first | |
238 if (os::Linux::chained_handler(sig, info, ucVoid)) { | |
239 return true; | |
240 } else { | |
241 if (PrintMiscellaneous && (WizardMode || Verbose)) { | |
242 char buf[64]; | |
243 warning("Ignoring %s - see bugs 4229104 or 646499219", | |
244 os::exception_name(sig, buf, sizeof(buf))); | |
245 } | |
246 return true; | |
247 } | |
248 } | |
249 | |
250 JavaThread* thread = NULL; | |
251 VMThread* vmthread = NULL; | |
252 if (os::Linux::signal_handlers_are_installed) { | |
253 if (t != NULL ){ | |
254 if(t->is_Java_thread()) { | |
255 thread = (JavaThread*)t; | |
256 } | |
257 else if(t->is_VM_thread()){ | |
258 vmthread = (VMThread *)t; | |
259 } | |
260 } | |
261 } | |
262 /* | |
263 NOTE: does not seem to work on linux. | |
264 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { | |
265 // can't decode this kind of signal | |
266 info = NULL; | |
267 } else { | |
268 assert(sig == info->si_signo, "bad siginfo"); | |
269 } | |
270 */ | |
271 // decide if this trap can be handled by a stub | |
272 address stub = NULL; | |
273 | |
274 address pc = NULL; | |
275 | |
276 //%note os_trap_1 | |
277 if (info != NULL && uc != NULL && thread != NULL) { | |
278 pc = (address) os::Linux::ucontext_get_pc(uc); | |
279 | |
11127 | 280 if (StubRoutines::is_safefetch_fault(pc)) { |
281 uc->uc_mcontext.gregs[REG_PC] = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc)); | |
282 return 1; | |
0 | 283 } |
284 | |
11029 | 285 #ifndef AMD64 |
286 // Halt if SI_KERNEL before more crashes get misdiagnosed as Java bugs | |
287 // This can happen in any running code (currently more frequently in | |
288 // interpreter code but has been seen in compiled code) | |
289 if (sig == SIGSEGV && info->si_addr == 0 && info->si_code == SI_KERNEL) { | |
290 fatal("An irrecoverable SI_KERNEL SIGSEGV has occurred due " | |
291 "to unstable signal handling in this distribution."); | |
292 } | |
293 #endif // AMD64 | |
294 | |
0 | 295 // Handle ALL stack overflow variations here |
296 if (sig == SIGSEGV) { | |
297 address addr = (address) info->si_addr; | |
298 | |
299 // check if fault address is within thread stack | |
300 if (addr < thread->stack_base() && | |
301 addr >= thread->stack_base() - thread->stack_size()) { | |
302 // stack overflow | |
303 if (thread->in_stack_yellow_zone(addr)) { | |
304 thread->disable_stack_yellow_zone(); | |
305 if (thread->thread_state() == _thread_in_Java) { | |
306 // Throw a stack overflow exception. Guard pages will be reenabled | |
307 // while unwinding the stack. | |
308 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); | |
309 } else { | |
310 // Thread was in the vm or native code. Return and try to finish. | |
311 return 1; | |
312 } | |
313 } else if (thread->in_stack_red_zone(addr)) { | |
314 // Fatal red zone violation. Disable the guard pages and fall through | |
315 // to handle_unexpected_exception way down below. | |
316 thread->disable_stack_red_zone(); | |
317 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); | |
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318 |
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319 // This is a likely cause, but hard to verify. Let's just print |
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320 // it as a hint. |
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321 tty->print_raw_cr("Please check if any of your loaded .so files has " |
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322 "enabled executable stack (see man page execstack(8))"); |
0 | 323 } else { |
324 // Accessing stack address below sp may cause SEGV if current | |
325 // thread has MAP_GROWSDOWN stack. This should only happen when | |
326 // current thread was created by user code with MAP_GROWSDOWN flag | |
327 // and then attached to VM. See notes in os_linux.cpp. | |
328 if (thread->osthread()->expanding_stack() == 0) { | |
329 thread->osthread()->set_expanding_stack(); | |
330 if (os::Linux::manually_expand_stack(thread, addr)) { | |
331 thread->osthread()->clear_expanding_stack(); | |
332 return 1; | |
333 } | |
334 thread->osthread()->clear_expanding_stack(); | |
335 } else { | |
336 fatal("recursive segv. expanding stack."); | |
337 } | |
338 } | |
339 } | |
340 } | |
341 | |
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342 if ((sig == SIGSEGV) && VM_Version::is_cpuinfo_segv_addr(pc)) { |
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343 // Verify that OS save/restore AVX registers. |
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344 stub = VM_Version::cpuinfo_cont_addr(); |
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345 } |
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346 |
0 | 347 if (thread->thread_state() == _thread_in_Java) { |
348 // Java thread running in Java code => find exception handler if any | |
349 // a fault inside compiled code, the interpreter, or a stub | |
350 | |
351 if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) { | |
352 stub = SharedRuntime::get_poll_stub(pc); | |
353 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { | |
354 // BugId 4454115: A read from a MappedByteBuffer can fault | |
355 // here if the underlying file has been truncated. | |
356 // Do not crash the VM in such a case. | |
357 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); | |
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358 nmethod* nm = (cb != NULL && cb->is_nmethod()) ? (nmethod*)cb : NULL; |
0 | 359 if (nm != NULL && nm->has_unsafe_access()) { |
360 stub = StubRoutines::handler_for_unsafe_access(); | |
361 } | |
362 } | |
363 else | |
364 | |
365 #ifdef AMD64 | |
366 if (sig == SIGFPE && | |
367 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { | |
368 stub = | |
369 SharedRuntime:: | |
370 continuation_for_implicit_exception(thread, | |
371 pc, | |
372 SharedRuntime:: | |
373 IMPLICIT_DIVIDE_BY_ZERO); | |
374 #else | |
375 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { | |
376 // HACK: si_code does not work on linux 2.2.12-20!!! | |
377 int op = pc[0]; | |
378 if (op == 0xDB) { | |
379 // FIST | |
380 // TODO: The encoding of D2I in i486.ad can cause an exception | |
381 // prior to the fist instruction if there was an invalid operation | |
382 // pending. We want to dismiss that exception. From the win_32 | |
383 // side it also seems that if it really was the fist causing | |
384 // the exception that we do the d2i by hand with different | |
385 // rounding. Seems kind of weird. | |
386 // NOTE: that we take the exception at the NEXT floating point instruction. | |
387 assert(pc[0] == 0xDB, "not a FIST opcode"); | |
388 assert(pc[1] == 0x14, "not a FIST opcode"); | |
389 assert(pc[2] == 0x24, "not a FIST opcode"); | |
390 return true; | |
391 } else if (op == 0xF7) { | |
392 // IDIV | |
393 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); | |
394 } else { | |
395 // TODO: handle more cases if we are using other x86 instructions | |
396 // that can generate SIGFPE signal on linux. | |
397 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); | |
398 fatal("please update this code."); | |
399 } | |
400 #endif // AMD64 | |
401 } else if (sig == SIGSEGV && | |
402 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { | |
403 // Determination of interpreter/vtable stub/compiled code null exception | |
404 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); | |
405 } | |
406 } else if (thread->thread_state() == _thread_in_vm && | |
407 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ | |
408 thread->doing_unsafe_access()) { | |
409 stub = StubRoutines::handler_for_unsafe_access(); | |
410 } | |
411 | |
412 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in | |
413 // and the heap gets shrunk before the field access. | |
414 if ((sig == SIGSEGV) || (sig == SIGBUS)) { | |
415 address addr = JNI_FastGetField::find_slowcase_pc(pc); | |
416 if (addr != (address)-1) { | |
417 stub = addr; | |
418 } | |
419 } | |
420 | |
421 // Check to see if we caught the safepoint code in the | |
422 // process of write protecting the memory serialization page. | |
423 // It write enables the page immediately after protecting it | |
424 // so we can just return to retry the write. | |
425 if ((sig == SIGSEGV) && | |
426 os::is_memory_serialize_page(thread, (address) info->si_addr)) { | |
427 // Block current thread until the memory serialize page permission restored. | |
428 os::block_on_serialize_page_trap(); | |
429 return true; | |
430 } | |
431 } | |
432 | |
433 #ifndef AMD64 | |
434 // Execution protection violation | |
435 // | |
436 // This should be kept as the last step in the triage. We don't | |
437 // have a dedicated trap number for a no-execute fault, so be | |
438 // conservative and allow other handlers the first shot. | |
439 // | |
440 // Note: We don't test that info->si_code == SEGV_ACCERR here. | |
441 // this si_code is so generic that it is almost meaningless; and | |
442 // the si_code for this condition may change in the future. | |
443 // Furthermore, a false-positive should be harmless. | |
444 if (UnguardOnExecutionViolation > 0 && | |
445 (sig == SIGSEGV || sig == SIGBUS) && | |
446 uc->uc_mcontext.gregs[REG_TRAPNO] == trap_page_fault) { | |
447 int page_size = os::vm_page_size(); | |
448 address addr = (address) info->si_addr; | |
449 address pc = os::Linux::ucontext_get_pc(uc); | |
450 // Make sure the pc and the faulting address are sane. | |
451 // | |
452 // If an instruction spans a page boundary, and the page containing | |
453 // the beginning of the instruction is executable but the following | |
454 // page is not, the pc and the faulting address might be slightly | |
455 // different - we still want to unguard the 2nd page in this case. | |
456 // | |
457 // 15 bytes seems to be a (very) safe value for max instruction size. | |
458 bool pc_is_near_addr = | |
459 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); | |
460 bool instr_spans_page_boundary = | |
461 (align_size_down((intptr_t) pc ^ (intptr_t) addr, | |
462 (intptr_t) page_size) > 0); | |
463 | |
464 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { | |
465 static volatile address last_addr = | |
466 (address) os::non_memory_address_word(); | |
467 | |
468 // In conservative mode, don't unguard unless the address is in the VM | |
469 if (addr != last_addr && | |
470 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { | |
471 | |
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472 // Set memory to RWX and retry |
0 | 473 address page_start = |
474 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); | |
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475 bool res = os::protect_memory((char*) page_start, page_size, |
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476 os::MEM_PROT_RWX); |
0 | 477 |
478 if (PrintMiscellaneous && Verbose) { | |
479 char buf[256]; | |
480 jio_snprintf(buf, sizeof(buf), "Execution protection violation " | |
481 "at " INTPTR_FORMAT | |
482 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, | |
483 page_start, (res ? "success" : "failed"), errno); | |
484 tty->print_raw_cr(buf); | |
485 } | |
486 stub = pc; | |
487 | |
488 // Set last_addr so if we fault again at the same address, we don't end | |
489 // up in an endless loop. | |
490 // | |
491 // There are two potential complications here. Two threads trapping at | |
492 // the same address at the same time could cause one of the threads to | |
493 // think it already unguarded, and abort the VM. Likely very rare. | |
494 // | |
495 // The other race involves two threads alternately trapping at | |
496 // different addresses and failing to unguard the page, resulting in | |
497 // an endless loop. This condition is probably even more unlikely than | |
498 // the first. | |
499 // | |
500 // Although both cases could be avoided by using locks or thread local | |
501 // last_addr, these solutions are unnecessary complication: this | |
502 // handler is a best-effort safety net, not a complete solution. It is | |
503 // disabled by default and should only be used as a workaround in case | |
504 // we missed any no-execute-unsafe VM code. | |
505 | |
506 last_addr = addr; | |
507 } | |
508 } | |
509 } | |
510 #endif // !AMD64 | |
511 | |
512 if (stub != NULL) { | |
513 // save all thread context in case we need to restore it | |
514 if (thread != NULL) thread->set_saved_exception_pc(pc); | |
515 | |
516 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub; | |
517 return true; | |
518 } | |
519 | |
520 // signal-chaining | |
521 if (os::Linux::chained_handler(sig, info, ucVoid)) { | |
522 return true; | |
523 } | |
524 | |
525 if (!abort_if_unrecognized) { | |
526 // caller wants another chance, so give it to him | |
527 return false; | |
528 } | |
529 | |
530 if (pc == NULL && uc != NULL) { | |
531 pc = os::Linux::ucontext_get_pc(uc); | |
532 } | |
533 | |
534 // unmask current signal | |
535 sigset_t newset; | |
536 sigemptyset(&newset); | |
537 sigaddset(&newset, sig); | |
538 sigprocmask(SIG_UNBLOCK, &newset, NULL); | |
539 | |
540 VMError err(t, sig, pc, info, ucVoid); | |
541 err.report_and_die(); | |
542 | |
543 ShouldNotReachHere(); | |
544 } | |
545 | |
546 void os::Linux::init_thread_fpu_state(void) { | |
547 #ifndef AMD64 | |
548 // set fpu to 53 bit precision | |
549 set_fpu_control_word(0x27f); | |
550 #endif // !AMD64 | |
551 } | |
552 | |
553 int os::Linux::get_fpu_control_word(void) { | |
554 #ifdef AMD64 | |
555 return 0; | |
556 #else | |
557 int fpu_control; | |
558 _FPU_GETCW(fpu_control); | |
559 return fpu_control & 0xffff; | |
560 #endif // AMD64 | |
561 } | |
562 | |
563 void os::Linux::set_fpu_control_word(int fpu_control) { | |
564 #ifndef AMD64 | |
565 _FPU_SETCW(fpu_control); | |
566 #endif // !AMD64 | |
567 } | |
568 | |
569 // Check that the linux kernel version is 2.4 or higher since earlier | |
570 // versions do not support SSE without patches. | |
571 bool os::supports_sse() { | |
572 #ifdef AMD64 | |
573 return true; | |
574 #else | |
575 struct utsname uts; | |
576 if( uname(&uts) != 0 ) return false; // uname fails? | |
577 char *minor_string; | |
578 int major = strtol(uts.release,&minor_string,10); | |
579 int minor = strtol(minor_string+1,NULL,10); | |
580 bool result = (major > 2 || (major==2 && minor >= 4)); | |
581 #ifndef PRODUCT | |
582 if (PrintMiscellaneous && Verbose) { | |
583 tty->print("OS version is %d.%d, which %s support SSE/SSE2\n", | |
584 major,minor, result ? "DOES" : "does NOT"); | |
585 } | |
586 #endif | |
587 return result; | |
588 #endif // AMD64 | |
589 } | |
590 | |
591 bool os::is_allocatable(size_t bytes) { | |
592 #ifdef AMD64 | |
593 // unused on amd64? | |
594 return true; | |
595 #else | |
596 | |
597 if (bytes < 2 * G) { | |
598 return true; | |
599 } | |
600 | |
601 char* addr = reserve_memory(bytes, NULL); | |
602 | |
603 if (addr != NULL) { | |
604 release_memory(addr, bytes); | |
605 } | |
606 | |
607 return addr != NULL; | |
608 #endif // AMD64 | |
609 } | |
610 | |
611 //////////////////////////////////////////////////////////////////////////////// | |
612 // thread stack | |
613 | |
614 #ifdef AMD64 | |
615 size_t os::Linux::min_stack_allowed = 64 * K; | |
616 | |
617 // amd64: pthread on amd64 is always in floating stack mode | |
618 bool os::Linux::supports_variable_stack_size() { return true; } | |
619 #else | |
620 size_t os::Linux::min_stack_allowed = (48 DEBUG_ONLY(+4))*K; | |
621 | |
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622 #ifdef __GNUC__ |
0 | 623 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) |
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624 #endif |
0 | 625 |
626 // Test if pthread library can support variable thread stack size. LinuxThreads | |
627 // in fixed stack mode allocates 2M fixed slot for each thread. LinuxThreads | |
628 // in floating stack mode and NPTL support variable stack size. | |
629 bool os::Linux::supports_variable_stack_size() { | |
630 if (os::Linux::is_NPTL()) { | |
631 // NPTL, yes | |
632 return true; | |
633 | |
634 } else { | |
635 // Note: We can't control default stack size when creating a thread. | |
636 // If we use non-default stack size (pthread_attr_setstacksize), both | |
637 // floating stack and non-floating stack LinuxThreads will return the | |
638 // same value. This makes it impossible to implement this function by | |
639 // detecting thread stack size directly. | |
640 // | |
641 // An alternative approach is to check %gs. Fixed-stack LinuxThreads | |
642 // do not use %gs, so its value is 0. Floating-stack LinuxThreads use | |
643 // %gs (either as LDT selector or GDT selector, depending on kernel) | |
644 // to access thread specific data. | |
645 // | |
646 // Note that %gs is a reserved glibc register since early 2001, so | |
647 // applications are not allowed to change its value (Ulrich Drepper from | |
648 // Redhat confirmed that all known offenders have been modified to use | |
649 // either %fs or TSD). In the worst case scenario, when VM is embedded in | |
650 // a native application that plays with %gs, we might see non-zero %gs | |
651 // even LinuxThreads is running in fixed stack mode. As the result, we'll | |
652 // return true and skip _thread_safety_check(), so we may not be able to | |
653 // detect stack-heap collisions. But otherwise it's harmless. | |
654 // | |
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655 #ifdef __GNUC__ |
0 | 656 return (GET_GS() != 0); |
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657 #else |
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658 return false; |
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659 #endif |
0 | 660 } |
661 } | |
662 #endif // AMD64 | |
663 | |
664 // return default stack size for thr_type | |
665 size_t os::Linux::default_stack_size(os::ThreadType thr_type) { | |
666 // default stack size (compiler thread needs larger stack) | |
667 #ifdef AMD64 | |
668 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); | |
669 #else | |
670 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); | |
671 #endif // AMD64 | |
672 return s; | |
673 } | |
674 | |
675 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { | |
676 // Creating guard page is very expensive. Java thread has HotSpot | |
677 // guard page, only enable glibc guard page for non-Java threads. | |
678 return (thr_type == java_thread ? 0 : page_size()); | |
679 } | |
680 | |
681 // Java thread: | |
682 // | |
683 // Low memory addresses | |
684 // +------------------------+ | |
685 // | |\ JavaThread created by VM does not have glibc | |
686 // | glibc guard page | - guard, attached Java thread usually has | |
687 // | |/ 1 page glibc guard. | |
688 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() | |
689 // | |\ | |
690 // | HotSpot Guard Pages | - red and yellow pages | |
691 // | |/ | |
692 // +------------------------+ JavaThread::stack_yellow_zone_base() | |
693 // | |\ | |
694 // | Normal Stack | - | |
695 // | |/ | |
696 // P2 +------------------------+ Thread::stack_base() | |
697 // | |
698 // Non-Java thread: | |
699 // | |
700 // Low memory addresses | |
701 // +------------------------+ | |
702 // | |\ | |
703 // | glibc guard page | - usually 1 page | |
704 // | |/ | |
705 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() | |
706 // | |\ | |
707 // | Normal Stack | - | |
708 // | |/ | |
709 // P2 +------------------------+ Thread::stack_base() | |
710 // | |
711 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from | |
712 // pthread_attr_getstack() | |
713 | |
714 static void current_stack_region(address * bottom, size_t * size) { | |
715 if (os::Linux::is_initial_thread()) { | |
716 // initial thread needs special handling because pthread_getattr_np() | |
717 // may return bogus value. | |
718 *bottom = os::Linux::initial_thread_stack_bottom(); | |
719 *size = os::Linux::initial_thread_stack_size(); | |
720 } else { | |
721 pthread_attr_t attr; | |
722 | |
723 int rslt = pthread_getattr_np(pthread_self(), &attr); | |
724 | |
725 // JVM needs to know exact stack location, abort if it fails | |
726 if (rslt != 0) { | |
727 if (rslt == ENOMEM) { | |
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728 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np"); |
0 | 729 } else { |
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730 fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt)); |
0 | 731 } |
732 } | |
733 | |
734 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { | |
735 fatal("Can not locate current stack attributes!"); | |
736 } | |
737 | |
738 pthread_attr_destroy(&attr); | |
739 | |
740 } | |
741 assert(os::current_stack_pointer() >= *bottom && | |
742 os::current_stack_pointer() < *bottom + *size, "just checking"); | |
743 } | |
744 | |
745 address os::current_stack_base() { | |
746 address bottom; | |
747 size_t size; | |
748 current_stack_region(&bottom, &size); | |
749 return (bottom + size); | |
750 } | |
751 | |
752 size_t os::current_stack_size() { | |
753 // stack size includes normal stack and HotSpot guard pages | |
754 address bottom; | |
755 size_t size; | |
756 current_stack_region(&bottom, &size); | |
757 return size; | |
758 } | |
759 | |
760 ///////////////////////////////////////////////////////////////////////////// | |
761 // helper functions for fatal error handler | |
762 | |
763 void os::print_context(outputStream *st, void *context) { | |
764 if (context == NULL) return; | |
765 | |
766 ucontext_t *uc = (ucontext_t*)context; | |
767 st->print_cr("Registers:"); | |
768 #ifdef AMD64 | |
769 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]); | |
770 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]); | |
771 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]); | |
772 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]); | |
773 st->cr(); | |
774 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]); | |
775 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]); | |
776 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]); | |
777 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]); | |
778 st->cr(); | |
779 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]); | |
780 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]); | |
781 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]); | |
782 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]); | |
783 st->cr(); | |
784 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]); | |
785 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]); | |
786 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]); | |
787 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]); | |
788 st->cr(); | |
789 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]); | |
1907 | 790 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]); |
0 | 791 st->print(", CSGSFS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_CSGSFS]); |
792 st->print(", ERR=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ERR]); | |
793 st->cr(); | |
794 st->print(" TRAPNO=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_TRAPNO]); | |
795 #else | |
796 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EAX]); | |
797 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBX]); | |
798 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ECX]); | |
799 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDX]); | |
800 st->cr(); | |
801 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_UESP]); | |
802 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBP]); | |
803 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ESI]); | |
804 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDI]); | |
805 st->cr(); | |
806 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EIP]); | |
1907 | 807 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]); |
0 | 808 st->print(", CR2=" INTPTR_FORMAT, uc->uc_mcontext.cr2); |
809 #endif // AMD64 | |
810 st->cr(); | |
811 st->cr(); | |
812 | |
813 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc); | |
814 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); | |
815 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); | |
816 st->cr(); | |
817 | |
818 // Note: it may be unsafe to inspect memory near pc. For example, pc may | |
819 // point to garbage if entry point in an nmethod is corrupted. Leave | |
820 // this at the end, and hope for the best. | |
821 address pc = os::Linux::ucontext_get_pc(uc); | |
822 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); | |
1907 | 823 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); |
824 } | |
825 | |
826 void os::print_register_info(outputStream *st, void *context) { | |
827 if (context == NULL) return; | |
828 | |
829 ucontext_t *uc = (ucontext_t*)context; | |
830 | |
831 st->print_cr("Register to memory mapping:"); | |
832 st->cr(); | |
833 | |
834 // this is horrendously verbose but the layout of the registers in the | |
835 // context does not match how we defined our abstract Register set, so | |
836 // we can't just iterate through the gregs area | |
837 | |
838 // this is only for the "general purpose" registers | |
839 | |
840 #ifdef AMD64 | |
841 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]); | |
842 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]); | |
843 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]); | |
844 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]); | |
845 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]); | |
846 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]); | |
847 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]); | |
848 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]); | |
849 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]); | |
850 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]); | |
851 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]); | |
852 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]); | |
853 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]); | |
854 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]); | |
855 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]); | |
856 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]); | |
857 #else | |
858 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[REG_EAX]); | |
859 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[REG_EBX]); | |
860 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[REG_ECX]); | |
861 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[REG_EDX]); | |
862 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[REG_ESP]); | |
863 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[REG_EBP]); | |
864 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[REG_ESI]); | |
865 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[REG_EDI]); | |
866 #endif // AMD64 | |
867 | |
868 st->cr(); | |
0 | 869 } |
870 | |
871 void os::setup_fpu() { | |
872 #ifndef AMD64 | |
873 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); | |
874 __asm__ volatile ( "fldcw (%0)" : | |
875 : "r" (fpu_cntrl) : "memory"); | |
876 #endif // !AMD64 | |
877 } | |
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878 |
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879 #ifndef PRODUCT |
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880 void os::verify_stack_alignment() { |
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881 #ifdef AMD64 |
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882 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment"); |
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883 #endif |
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884 } |
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885 #endif |
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886 |
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887 |
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888 /* |
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889 * IA32 only: execute code at a high address in case buggy NX emulation is present. I.e. avoid CS limit |
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890 * updates (JDK-8023956). |
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891 */ |
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892 void os::workaround_expand_exec_shield_cs_limit() { |
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893 #if defined(IA32) |
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894 size_t page_size = os::vm_page_size(); |
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895 /* |
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896 * Take the highest VA the OS will give us and exec |
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897 * |
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898 * Although using -(pagesz) as mmap hint works on newer kernel as you would |
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899 * think, older variants affected by this work-around don't (search forward only). |
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900 * |
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901 * On the affected distributions, we understand the memory layout to be: |
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902 * |
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903 * TASK_LIMIT= 3G, main stack base close to TASK_LIMT. |
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904 * |
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905 * A few pages south main stack will do it. |
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906 * |
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907 * If we are embedded in an app other than launcher (initial != main stack), |
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908 * we don't have much control or understanding of the address space, just let it slide. |
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909 */ |
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910 char* hint = (char*) (Linux::initial_thread_stack_bottom() - |
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911 ((StackYellowPages + StackRedPages + 1) * page_size)); |
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912 char* codebuf = os::attempt_reserve_memory_at(page_size, hint); |
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913 if ( (codebuf == NULL) || (!os::commit_memory(codebuf, page_size, true)) ) { |
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914 return; // No matter, we tried, best effort. |
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915 } |
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916 if (PrintMiscellaneous && (Verbose || WizardMode)) { |
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917 tty->print_cr("[CS limit NX emulation work-around, exec code at: %p]", codebuf); |
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918 } |
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919 |
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920 // Some code to exec: the 'ret' instruction |
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921 codebuf[0] = 0xC3; |
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922 |
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923 // Call the code in the codebuf |
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924 __asm__ volatile("call *%0" : : "r"(codebuf)); |
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925 |
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926 // keep the page mapped so CS limit isn't reduced. |
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927 #endif |
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928 } |