Mercurial > hg > truffle
annotate src/os_cpu/linux_x86/vm/os_linux_x86.cpp @ 14714:b602356a9cfc
additional canonicalizers for accesses and value nodes (improves number of implicit null checks)
author | Lukas Stadler <lukas.stadler@oracle.com> |
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date | Thu, 20 Mar 2014 17:15:36 +0100 |
parents | d8041d695d19 |
children | 4ca6dc0799b6 |
rev | line source |
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0 | 1 /* |
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2 * Copyright (c) 1999, 2013, 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" |
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52 #include "services/memTracker.hpp" |
1972 | 53 #include "utilities/events.hpp" |
54 #include "utilities/vmError.hpp" | |
0 | 55 |
56 // put OS-includes here | |
57 # include <sys/types.h> | |
58 # include <sys/mman.h> | |
59 # include <pthread.h> | |
60 # include <signal.h> | |
61 # include <errno.h> | |
62 # include <dlfcn.h> | |
63 # include <stdlib.h> | |
64 # include <stdio.h> | |
65 # include <unistd.h> | |
66 # include <sys/resource.h> | |
67 # include <pthread.h> | |
68 # include <sys/stat.h> | |
69 # include <sys/time.h> | |
70 # include <sys/utsname.h> | |
71 # include <sys/socket.h> | |
72 # include <sys/wait.h> | |
73 # include <pwd.h> | |
74 # include <poll.h> | |
75 # include <ucontext.h> | |
76 # include <fpu_control.h> | |
77 | |
78 #ifdef AMD64 | |
79 #define REG_SP REG_RSP | |
80 #define REG_PC REG_RIP | |
81 #define REG_FP REG_RBP | |
82 #define SPELL_REG_SP "rsp" | |
83 #define SPELL_REG_FP "rbp" | |
84 #else | |
85 #define REG_SP REG_UESP | |
86 #define REG_PC REG_EIP | |
87 #define REG_FP REG_EBP | |
88 #define SPELL_REG_SP "esp" | |
89 #define SPELL_REG_FP "ebp" | |
90 #endif // AMD64 | |
91 | |
92 address os::current_stack_pointer() { | |
50
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93 #ifdef SPARC_WORKS |
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94 register void *esp; |
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95 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); |
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96 return (address) ((char*)esp + sizeof(long)*2); |
10398 | 97 #elif defined(__clang__) |
98 intptr_t* esp; | |
99 __asm__ __volatile__ ("mov %%"SPELL_REG_SP", %0":"=r"(esp):); | |
100 return (address) esp; | |
50
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101 #else |
0 | 102 register void *esp __asm__ (SPELL_REG_SP); |
103 return (address) esp; | |
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104 #endif |
0 | 105 } |
106 | |
107 char* os::non_memory_address_word() { | |
108 // Must never look like an address returned by reserve_memory, | |
109 // even in its subfields (as defined by the CPU immediate fields, | |
110 // if the CPU splits constants across multiple instructions). | |
111 | |
112 return (char*) -1; | |
113 } | |
114 | |
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115 void os::initialize_thread(Thread* thr) { |
0 | 116 // Nothing to do. |
117 } | |
118 | |
119 address os::Linux::ucontext_get_pc(ucontext_t * uc) { | |
120 return (address)uc->uc_mcontext.gregs[REG_PC]; | |
121 } | |
122 | |
123 intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) { | |
124 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP]; | |
125 } | |
126 | |
127 intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) { | |
128 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP]; | |
129 } | |
130 | |
131 // For Forte Analyzer AsyncGetCallTrace profiling support - thread | |
132 // is currently interrupted by SIGPROF. | |
133 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal | |
134 // frames. Currently we don't do that on Linux, so it's the same as | |
135 // os::fetch_frame_from_context(). | |
136 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread, | |
137 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { | |
138 | |
139 assert(thread != NULL, "just checking"); | |
140 assert(ret_sp != NULL, "just checking"); | |
141 assert(ret_fp != NULL, "just checking"); | |
142 | |
143 return os::fetch_frame_from_context(uc, ret_sp, ret_fp); | |
144 } | |
145 | |
146 ExtendedPC os::fetch_frame_from_context(void* ucVoid, | |
147 intptr_t** ret_sp, intptr_t** ret_fp) { | |
148 | |
149 ExtendedPC epc; | |
150 ucontext_t* uc = (ucontext_t*)ucVoid; | |
151 | |
152 if (uc != NULL) { | |
153 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc)); | |
154 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc); | |
155 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc); | |
156 } else { | |
157 // construct empty ExtendedPC for return value checking | |
158 epc = ExtendedPC(NULL); | |
159 if (ret_sp) *ret_sp = (intptr_t *)NULL; | |
160 if (ret_fp) *ret_fp = (intptr_t *)NULL; | |
161 } | |
162 | |
163 return epc; | |
164 } | |
165 | |
166 frame os::fetch_frame_from_context(void* ucVoid) { | |
167 intptr_t* sp; | |
168 intptr_t* fp; | |
169 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); | |
170 return frame(sp, fp, epc.pc()); | |
171 } | |
172 | |
173 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get | |
174 // turned off by -fomit-frame-pointer, | |
175 frame os::get_sender_for_C_frame(frame* fr) { | |
176 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); | |
177 } | |
178 | |
179 intptr_t* _get_previous_fp() { | |
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180 #ifdef SPARC_WORKS |
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181 register intptr_t **ebp; |
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182 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp)); |
10398 | 183 #elif defined(__clang__) |
184 intptr_t **ebp; | |
185 __asm__ __volatile__ ("mov %%"SPELL_REG_FP", %0":"=r"(ebp):); | |
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186 #else |
0 | 187 register intptr_t **ebp __asm__ (SPELL_REG_FP); |
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188 #endif |
0 | 189 return (intptr_t*) *ebp; // we want what it points to. |
190 } | |
191 | |
192 | |
193 frame os::current_frame() { | |
194 intptr_t* fp = _get_previous_fp(); | |
195 frame myframe((intptr_t*)os::current_stack_pointer(), | |
196 (intptr_t*)fp, | |
197 CAST_FROM_FN_PTR(address, os::current_frame)); | |
198 if (os::is_first_C_frame(&myframe)) { | |
199 // stack is not walkable | |
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200 return frame(); |
0 | 201 } else { |
202 return os::get_sender_for_C_frame(&myframe); | |
203 } | |
204 } | |
205 | |
206 // Utility functions | |
207 | |
208 // From IA32 System Programming Guide | |
209 enum { | |
210 trap_page_fault = 0xE | |
211 }; | |
212 | |
2191 | 213 extern "C" JNIEXPORT int |
0 | 214 JVM_handle_linux_signal(int sig, |
215 siginfo_t* info, | |
216 void* ucVoid, | |
217 int abort_if_unrecognized) { | |
218 ucontext_t* uc = (ucontext_t*) ucVoid; | |
219 | |
220 Thread* t = ThreadLocalStorage::get_thread_slow(); | |
221 | |
11151 | 222 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away |
223 // (no destructors can be run) | |
224 os::WatcherThreadCrashProtection::check_crash_protection(sig, t); | |
225 | |
0 | 226 SignalHandlerMark shm(t); |
227 | |
228 // Note: it's not uncommon that JNI code uses signal/sigset to install | |
229 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, | |
230 // or have a SIGILL handler when detecting CPU type). When that happens, | |
231 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To | |
232 // avoid unnecessary crash when libjsig is not preloaded, try handle signals | |
233 // that do not require siginfo/ucontext first. | |
234 | |
235 if (sig == SIGPIPE || sig == SIGXFSZ) { | |
236 // allow chained handler to go first | |
237 if (os::Linux::chained_handler(sig, info, ucVoid)) { | |
238 return true; | |
239 } else { | |
240 if (PrintMiscellaneous && (WizardMode || Verbose)) { | |
241 char buf[64]; | |
242 warning("Ignoring %s - see bugs 4229104 or 646499219", | |
243 os::exception_name(sig, buf, sizeof(buf))); | |
244 } | |
245 return true; | |
246 } | |
247 } | |
248 | |
249 JavaThread* thread = NULL; | |
250 VMThread* vmthread = NULL; | |
251 if (os::Linux::signal_handlers_are_installed) { | |
252 if (t != NULL ){ | |
253 if(t->is_Java_thread()) { | |
254 thread = (JavaThread*)t; | |
255 } | |
256 else if(t->is_VM_thread()){ | |
257 vmthread = (VMThread *)t; | |
258 } | |
259 } | |
260 } | |
261 /* | |
262 NOTE: does not seem to work on linux. | |
263 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { | |
264 // can't decode this kind of signal | |
265 info = NULL; | |
266 } else { | |
267 assert(sig == info->si_signo, "bad siginfo"); | |
268 } | |
269 */ | |
270 // decide if this trap can be handled by a stub | |
271 address stub = NULL; | |
272 | |
273 address pc = NULL; | |
274 | |
275 //%note os_trap_1 | |
276 if (info != NULL && uc != NULL && thread != NULL) { | |
277 pc = (address) os::Linux::ucontext_get_pc(uc); | |
278 | |
11127 | 279 if (StubRoutines::is_safefetch_fault(pc)) { |
280 uc->uc_mcontext.gregs[REG_PC] = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc)); | |
281 return 1; | |
0 | 282 } |
283 | |
11029 | 284 #ifndef AMD64 |
285 // Halt if SI_KERNEL before more crashes get misdiagnosed as Java bugs | |
286 // This can happen in any running code (currently more frequently in | |
287 // interpreter code but has been seen in compiled code) | |
288 if (sig == SIGSEGV && info->si_addr == 0 && info->si_code == SI_KERNEL) { | |
289 fatal("An irrecoverable SI_KERNEL SIGSEGV has occurred due " | |
290 "to unstable signal handling in this distribution."); | |
291 } | |
292 #endif // AMD64 | |
293 | |
0 | 294 // Handle ALL stack overflow variations here |
295 if (sig == SIGSEGV) { | |
296 address addr = (address) info->si_addr; | |
297 | |
298 // check if fault address is within thread stack | |
299 if (addr < thread->stack_base() && | |
300 addr >= thread->stack_base() - thread->stack_size()) { | |
301 // stack overflow | |
302 if (thread->in_stack_yellow_zone(addr)) { | |
303 thread->disable_stack_yellow_zone(); | |
304 if (thread->thread_state() == _thread_in_Java) { | |
305 // Throw a stack overflow exception. Guard pages will be reenabled | |
306 // while unwinding the stack. | |
307 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); | |
308 } else { | |
309 // Thread was in the vm or native code. Return and try to finish. | |
310 return 1; | |
311 } | |
312 } else if (thread->in_stack_red_zone(addr)) { | |
313 // Fatal red zone violation. Disable the guard pages and fall through | |
314 // to handle_unexpected_exception way down below. | |
315 thread->disable_stack_red_zone(); | |
316 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); | |
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317 |
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318 // This is a likely cause, but hard to verify. Let's just print |
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319 // it as a hint. |
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320 tty->print_raw_cr("Please check if any of your loaded .so files has " |
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321 "enabled executable stack (see man page execstack(8))"); |
0 | 322 } else { |
323 // Accessing stack address below sp may cause SEGV if current | |
324 // thread has MAP_GROWSDOWN stack. This should only happen when | |
325 // current thread was created by user code with MAP_GROWSDOWN flag | |
326 // and then attached to VM. See notes in os_linux.cpp. | |
327 if (thread->osthread()->expanding_stack() == 0) { | |
328 thread->osthread()->set_expanding_stack(); | |
329 if (os::Linux::manually_expand_stack(thread, addr)) { | |
330 thread->osthread()->clear_expanding_stack(); | |
331 return 1; | |
332 } | |
333 thread->osthread()->clear_expanding_stack(); | |
334 } else { | |
335 fatal("recursive segv. expanding stack."); | |
336 } | |
337 } | |
338 } | |
339 } | |
340 | |
341 if (thread->thread_state() == _thread_in_Java) { | |
342 // Java thread running in Java code => find exception handler if any | |
343 // a fault inside compiled code, the interpreter, or a stub | |
344 | |
345 if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) { | |
346 stub = SharedRuntime::get_poll_stub(pc); | |
347 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { | |
348 // BugId 4454115: A read from a MappedByteBuffer can fault | |
349 // here if the underlying file has been truncated. | |
350 // Do not crash the VM in such a case. | |
351 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); | |
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352 nmethod* nm = (cb != NULL && cb->is_nmethod()) ? (nmethod*)cb : NULL; |
0 | 353 if (nm != NULL && nm->has_unsafe_access()) { |
354 stub = StubRoutines::handler_for_unsafe_access(); | |
355 } | |
356 } | |
357 else | |
358 | |
359 #ifdef AMD64 | |
360 if (sig == SIGFPE && | |
361 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { | |
362 stub = | |
363 SharedRuntime:: | |
364 continuation_for_implicit_exception(thread, | |
365 pc, | |
366 SharedRuntime:: | |
367 IMPLICIT_DIVIDE_BY_ZERO); | |
368 #else | |
369 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { | |
370 // HACK: si_code does not work on linux 2.2.12-20!!! | |
371 int op = pc[0]; | |
372 if (op == 0xDB) { | |
373 // FIST | |
374 // TODO: The encoding of D2I in i486.ad can cause an exception | |
375 // prior to the fist instruction if there was an invalid operation | |
376 // pending. We want to dismiss that exception. From the win_32 | |
377 // side it also seems that if it really was the fist causing | |
378 // the exception that we do the d2i by hand with different | |
379 // rounding. Seems kind of weird. | |
380 // NOTE: that we take the exception at the NEXT floating point instruction. | |
381 assert(pc[0] == 0xDB, "not a FIST opcode"); | |
382 assert(pc[1] == 0x14, "not a FIST opcode"); | |
383 assert(pc[2] == 0x24, "not a FIST opcode"); | |
384 return true; | |
385 } else if (op == 0xF7) { | |
386 // IDIV | |
387 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); | |
388 } else { | |
389 // TODO: handle more cases if we are using other x86 instructions | |
390 // that can generate SIGFPE signal on linux. | |
391 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); | |
392 fatal("please update this code."); | |
393 } | |
394 #endif // AMD64 | |
395 } else if (sig == SIGSEGV && | |
396 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { | |
397 // Determination of interpreter/vtable stub/compiled code null exception | |
398 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); | |
399 } | |
400 } else if (thread->thread_state() == _thread_in_vm && | |
401 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ | |
402 thread->doing_unsafe_access()) { | |
403 stub = StubRoutines::handler_for_unsafe_access(); | |
404 } | |
405 | |
406 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in | |
407 // and the heap gets shrunk before the field access. | |
408 if ((sig == SIGSEGV) || (sig == SIGBUS)) { | |
409 address addr = JNI_FastGetField::find_slowcase_pc(pc); | |
410 if (addr != (address)-1) { | |
411 stub = addr; | |
412 } | |
413 } | |
414 | |
415 // Check to see if we caught the safepoint code in the | |
416 // process of write protecting the memory serialization page. | |
417 // It write enables the page immediately after protecting it | |
418 // so we can just return to retry the write. | |
419 if ((sig == SIGSEGV) && | |
420 os::is_memory_serialize_page(thread, (address) info->si_addr)) { | |
421 // Block current thread until the memory serialize page permission restored. | |
422 os::block_on_serialize_page_trap(); | |
423 return true; | |
424 } | |
425 } | |
426 | |
427 #ifndef AMD64 | |
428 // Execution protection violation | |
429 // | |
430 // This should be kept as the last step in the triage. We don't | |
431 // have a dedicated trap number for a no-execute fault, so be | |
432 // conservative and allow other handlers the first shot. | |
433 // | |
434 // Note: We don't test that info->si_code == SEGV_ACCERR here. | |
435 // this si_code is so generic that it is almost meaningless; and | |
436 // the si_code for this condition may change in the future. | |
437 // Furthermore, a false-positive should be harmless. | |
438 if (UnguardOnExecutionViolation > 0 && | |
439 (sig == SIGSEGV || sig == SIGBUS) && | |
440 uc->uc_mcontext.gregs[REG_TRAPNO] == trap_page_fault) { | |
441 int page_size = os::vm_page_size(); | |
442 address addr = (address) info->si_addr; | |
443 address pc = os::Linux::ucontext_get_pc(uc); | |
444 // Make sure the pc and the faulting address are sane. | |
445 // | |
446 // If an instruction spans a page boundary, and the page containing | |
447 // the beginning of the instruction is executable but the following | |
448 // page is not, the pc and the faulting address might be slightly | |
449 // different - we still want to unguard the 2nd page in this case. | |
450 // | |
451 // 15 bytes seems to be a (very) safe value for max instruction size. | |
452 bool pc_is_near_addr = | |
453 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); | |
454 bool instr_spans_page_boundary = | |
455 (align_size_down((intptr_t) pc ^ (intptr_t) addr, | |
456 (intptr_t) page_size) > 0); | |
457 | |
458 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { | |
459 static volatile address last_addr = | |
460 (address) os::non_memory_address_word(); | |
461 | |
462 // In conservative mode, don't unguard unless the address is in the VM | |
463 if (addr != last_addr && | |
464 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { | |
465 | |
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466 // Set memory to RWX and retry |
0 | 467 address page_start = |
468 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); | |
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469 bool res = os::protect_memory((char*) page_start, page_size, |
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470 os::MEM_PROT_RWX); |
0 | 471 |
472 if (PrintMiscellaneous && Verbose) { | |
473 char buf[256]; | |
474 jio_snprintf(buf, sizeof(buf), "Execution protection violation " | |
475 "at " INTPTR_FORMAT | |
476 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, | |
477 page_start, (res ? "success" : "failed"), errno); | |
478 tty->print_raw_cr(buf); | |
479 } | |
480 stub = pc; | |
481 | |
482 // Set last_addr so if we fault again at the same address, we don't end | |
483 // up in an endless loop. | |
484 // | |
485 // There are two potential complications here. Two threads trapping at | |
486 // the same address at the same time could cause one of the threads to | |
487 // think it already unguarded, and abort the VM. Likely very rare. | |
488 // | |
489 // The other race involves two threads alternately trapping at | |
490 // different addresses and failing to unguard the page, resulting in | |
491 // an endless loop. This condition is probably even more unlikely than | |
492 // the first. | |
493 // | |
494 // Although both cases could be avoided by using locks or thread local | |
495 // last_addr, these solutions are unnecessary complication: this | |
496 // handler is a best-effort safety net, not a complete solution. It is | |
497 // disabled by default and should only be used as a workaround in case | |
498 // we missed any no-execute-unsafe VM code. | |
499 | |
500 last_addr = addr; | |
501 } | |
502 } | |
503 } | |
504 #endif // !AMD64 | |
505 | |
506 if (stub != NULL) { | |
507 // save all thread context in case we need to restore it | |
508 if (thread != NULL) thread->set_saved_exception_pc(pc); | |
509 | |
510 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub; | |
511 return true; | |
512 } | |
513 | |
514 // signal-chaining | |
515 if (os::Linux::chained_handler(sig, info, ucVoid)) { | |
516 return true; | |
517 } | |
518 | |
519 if (!abort_if_unrecognized) { | |
520 // caller wants another chance, so give it to him | |
521 return false; | |
522 } | |
523 | |
524 if (pc == NULL && uc != NULL) { | |
525 pc = os::Linux::ucontext_get_pc(uc); | |
526 } | |
527 | |
528 // unmask current signal | |
529 sigset_t newset; | |
530 sigemptyset(&newset); | |
531 sigaddset(&newset, sig); | |
532 sigprocmask(SIG_UNBLOCK, &newset, NULL); | |
533 | |
534 VMError err(t, sig, pc, info, ucVoid); | |
535 err.report_and_die(); | |
536 | |
537 ShouldNotReachHere(); | |
538 } | |
539 | |
540 void os::Linux::init_thread_fpu_state(void) { | |
541 #ifndef AMD64 | |
542 // set fpu to 53 bit precision | |
543 set_fpu_control_word(0x27f); | |
544 #endif // !AMD64 | |
545 } | |
546 | |
547 int os::Linux::get_fpu_control_word(void) { | |
548 #ifdef AMD64 | |
549 return 0; | |
550 #else | |
551 int fpu_control; | |
552 _FPU_GETCW(fpu_control); | |
553 return fpu_control & 0xffff; | |
554 #endif // AMD64 | |
555 } | |
556 | |
557 void os::Linux::set_fpu_control_word(int fpu_control) { | |
558 #ifndef AMD64 | |
559 _FPU_SETCW(fpu_control); | |
560 #endif // !AMD64 | |
561 } | |
562 | |
563 // Check that the linux kernel version is 2.4 or higher since earlier | |
564 // versions do not support SSE without patches. | |
565 bool os::supports_sse() { | |
566 #ifdef AMD64 | |
567 return true; | |
568 #else | |
569 struct utsname uts; | |
570 if( uname(&uts) != 0 ) return false; // uname fails? | |
571 char *minor_string; | |
572 int major = strtol(uts.release,&minor_string,10); | |
573 int minor = strtol(minor_string+1,NULL,10); | |
574 bool result = (major > 2 || (major==2 && minor >= 4)); | |
575 #ifndef PRODUCT | |
576 if (PrintMiscellaneous && Verbose) { | |
577 tty->print("OS version is %d.%d, which %s support SSE/SSE2\n", | |
578 major,minor, result ? "DOES" : "does NOT"); | |
579 } | |
580 #endif | |
581 return result; | |
582 #endif // AMD64 | |
583 } | |
584 | |
585 bool os::is_allocatable(size_t bytes) { | |
586 #ifdef AMD64 | |
587 // unused on amd64? | |
588 return true; | |
589 #else | |
590 | |
591 if (bytes < 2 * G) { | |
592 return true; | |
593 } | |
594 | |
595 char* addr = reserve_memory(bytes, NULL); | |
596 | |
597 if (addr != NULL) { | |
598 release_memory(addr, bytes); | |
599 } | |
600 | |
601 return addr != NULL; | |
602 #endif // AMD64 | |
603 } | |
604 | |
605 //////////////////////////////////////////////////////////////////////////////// | |
606 // thread stack | |
607 | |
608 #ifdef AMD64 | |
609 size_t os::Linux::min_stack_allowed = 64 * K; | |
610 | |
611 // amd64: pthread on amd64 is always in floating stack mode | |
612 bool os::Linux::supports_variable_stack_size() { return true; } | |
613 #else | |
614 size_t os::Linux::min_stack_allowed = (48 DEBUG_ONLY(+4))*K; | |
615 | |
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616 #ifdef __GNUC__ |
0 | 617 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) |
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618 #endif |
0 | 619 |
620 // Test if pthread library can support variable thread stack size. LinuxThreads | |
621 // in fixed stack mode allocates 2M fixed slot for each thread. LinuxThreads | |
622 // in floating stack mode and NPTL support variable stack size. | |
623 bool os::Linux::supports_variable_stack_size() { | |
624 if (os::Linux::is_NPTL()) { | |
625 // NPTL, yes | |
626 return true; | |
627 | |
628 } else { | |
629 // Note: We can't control default stack size when creating a thread. | |
630 // If we use non-default stack size (pthread_attr_setstacksize), both | |
631 // floating stack and non-floating stack LinuxThreads will return the | |
632 // same value. This makes it impossible to implement this function by | |
633 // detecting thread stack size directly. | |
634 // | |
635 // An alternative approach is to check %gs. Fixed-stack LinuxThreads | |
636 // do not use %gs, so its value is 0. Floating-stack LinuxThreads use | |
637 // %gs (either as LDT selector or GDT selector, depending on kernel) | |
638 // to access thread specific data. | |
639 // | |
640 // Note that %gs is a reserved glibc register since early 2001, so | |
641 // applications are not allowed to change its value (Ulrich Drepper from | |
642 // Redhat confirmed that all known offenders have been modified to use | |
643 // either %fs or TSD). In the worst case scenario, when VM is embedded in | |
644 // a native application that plays with %gs, we might see non-zero %gs | |
645 // even LinuxThreads is running in fixed stack mode. As the result, we'll | |
646 // return true and skip _thread_safety_check(), so we may not be able to | |
647 // detect stack-heap collisions. But otherwise it's harmless. | |
648 // | |
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649 #ifdef __GNUC__ |
0 | 650 return (GET_GS() != 0); |
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651 #else |
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652 return false; |
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653 #endif |
0 | 654 } |
655 } | |
656 #endif // AMD64 | |
657 | |
658 // return default stack size for thr_type | |
659 size_t os::Linux::default_stack_size(os::ThreadType thr_type) { | |
660 // default stack size (compiler thread needs larger stack) | |
661 #ifdef AMD64 | |
662 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); | |
663 #else | |
664 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); | |
665 #endif // AMD64 | |
666 return s; | |
667 } | |
668 | |
669 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { | |
670 // Creating guard page is very expensive. Java thread has HotSpot | |
671 // guard page, only enable glibc guard page for non-Java threads. | |
672 return (thr_type == java_thread ? 0 : page_size()); | |
673 } | |
674 | |
675 // Java thread: | |
676 // | |
677 // Low memory addresses | |
678 // +------------------------+ | |
679 // | |\ JavaThread created by VM does not have glibc | |
680 // | glibc guard page | - guard, attached Java thread usually has | |
681 // | |/ 1 page glibc guard. | |
682 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() | |
683 // | |\ | |
684 // | HotSpot Guard Pages | - red and yellow pages | |
685 // | |/ | |
686 // +------------------------+ JavaThread::stack_yellow_zone_base() | |
687 // | |\ | |
688 // | Normal Stack | - | |
689 // | |/ | |
690 // P2 +------------------------+ Thread::stack_base() | |
691 // | |
692 // Non-Java thread: | |
693 // | |
694 // Low memory addresses | |
695 // +------------------------+ | |
696 // | |\ | |
697 // | glibc guard page | - usually 1 page | |
698 // | |/ | |
699 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() | |
700 // | |\ | |
701 // | Normal Stack | - | |
702 // | |/ | |
703 // P2 +------------------------+ Thread::stack_base() | |
704 // | |
705 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from | |
706 // pthread_attr_getstack() | |
707 | |
708 static void current_stack_region(address * bottom, size_t * size) { | |
709 if (os::Linux::is_initial_thread()) { | |
710 // initial thread needs special handling because pthread_getattr_np() | |
711 // may return bogus value. | |
712 *bottom = os::Linux::initial_thread_stack_bottom(); | |
713 *size = os::Linux::initial_thread_stack_size(); | |
714 } else { | |
715 pthread_attr_t attr; | |
716 | |
717 int rslt = pthread_getattr_np(pthread_self(), &attr); | |
718 | |
719 // JVM needs to know exact stack location, abort if it fails | |
720 if (rslt != 0) { | |
721 if (rslt == ENOMEM) { | |
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722 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np"); |
0 | 723 } else { |
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724 fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt)); |
0 | 725 } |
726 } | |
727 | |
728 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { | |
729 fatal("Can not locate current stack attributes!"); | |
730 } | |
731 | |
732 pthread_attr_destroy(&attr); | |
733 | |
734 } | |
735 assert(os::current_stack_pointer() >= *bottom && | |
736 os::current_stack_pointer() < *bottom + *size, "just checking"); | |
737 } | |
738 | |
739 address os::current_stack_base() { | |
740 address bottom; | |
741 size_t size; | |
742 current_stack_region(&bottom, &size); | |
743 return (bottom + size); | |
744 } | |
745 | |
746 size_t os::current_stack_size() { | |
747 // stack size includes normal stack and HotSpot guard pages | |
748 address bottom; | |
749 size_t size; | |
750 current_stack_region(&bottom, &size); | |
751 return size; | |
752 } | |
753 | |
754 ///////////////////////////////////////////////////////////////////////////// | |
755 // helper functions for fatal error handler | |
756 | |
757 void os::print_context(outputStream *st, void *context) { | |
758 if (context == NULL) return; | |
759 | |
760 ucontext_t *uc = (ucontext_t*)context; | |
761 st->print_cr("Registers:"); | |
762 #ifdef AMD64 | |
763 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]); | |
764 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]); | |
765 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]); | |
766 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]); | |
767 st->cr(); | |
768 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]); | |
769 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]); | |
770 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]); | |
771 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]); | |
772 st->cr(); | |
773 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]); | |
774 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]); | |
775 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]); | |
776 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]); | |
777 st->cr(); | |
778 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]); | |
779 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]); | |
780 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]); | |
781 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]); | |
782 st->cr(); | |
783 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]); | |
1907 | 784 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]); |
0 | 785 st->print(", CSGSFS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_CSGSFS]); |
786 st->print(", ERR=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ERR]); | |
787 st->cr(); | |
788 st->print(" TRAPNO=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_TRAPNO]); | |
789 #else | |
790 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EAX]); | |
791 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBX]); | |
792 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ECX]); | |
793 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDX]); | |
794 st->cr(); | |
795 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_UESP]); | |
796 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBP]); | |
797 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ESI]); | |
798 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDI]); | |
799 st->cr(); | |
800 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EIP]); | |
1907 | 801 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]); |
0 | 802 st->print(", CR2=" INTPTR_FORMAT, uc->uc_mcontext.cr2); |
803 #endif // AMD64 | |
804 st->cr(); | |
805 st->cr(); | |
806 | |
807 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc); | |
808 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); | |
809 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); | |
810 st->cr(); | |
811 | |
812 // Note: it may be unsafe to inspect memory near pc. For example, pc may | |
813 // point to garbage if entry point in an nmethod is corrupted. Leave | |
814 // this at the end, and hope for the best. | |
815 address pc = os::Linux::ucontext_get_pc(uc); | |
816 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); | |
1907 | 817 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); |
818 } | |
819 | |
820 void os::print_register_info(outputStream *st, void *context) { | |
821 if (context == NULL) return; | |
822 | |
823 ucontext_t *uc = (ucontext_t*)context; | |
824 | |
825 st->print_cr("Register to memory mapping:"); | |
826 st->cr(); | |
827 | |
828 // this is horrendously verbose but the layout of the registers in the | |
829 // context does not match how we defined our abstract Register set, so | |
830 // we can't just iterate through the gregs area | |
831 | |
832 // this is only for the "general purpose" registers | |
833 | |
834 #ifdef AMD64 | |
835 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]); | |
836 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]); | |
837 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]); | |
838 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]); | |
839 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]); | |
840 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]); | |
841 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]); | |
842 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]); | |
843 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]); | |
844 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]); | |
845 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]); | |
846 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]); | |
847 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]); | |
848 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]); | |
849 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]); | |
850 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]); | |
851 #else | |
852 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[REG_EAX]); | |
853 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[REG_EBX]); | |
854 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[REG_ECX]); | |
855 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[REG_EDX]); | |
856 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[REG_ESP]); | |
857 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[REG_EBP]); | |
858 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[REG_ESI]); | |
859 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[REG_EDI]); | |
860 #endif // AMD64 | |
861 | |
862 st->cr(); | |
0 | 863 } |
864 | |
865 void os::setup_fpu() { | |
866 #ifndef AMD64 | |
867 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); | |
868 __asm__ volatile ( "fldcw (%0)" : | |
869 : "r" (fpu_cntrl) : "memory"); | |
870 #endif // !AMD64 | |
871 } | |
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872 |
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873 #ifndef PRODUCT |
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874 void os::verify_stack_alignment() { |
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875 #ifdef AMD64 |
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876 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment"); |
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877 #endif |
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878 } |
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879 #endif |
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880 |
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881 |
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882 /* |
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883 * IA32 only: execute code at a high address in case buggy NX emulation is present. I.e. avoid CS limit |
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884 * updates (JDK-8023956). |
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885 */ |
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886 void os::workaround_expand_exec_shield_cs_limit() { |
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887 #if defined(IA32) |
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888 size_t page_size = os::vm_page_size(); |
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889 /* |
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890 * Take the highest VA the OS will give us and exec |
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891 * |
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892 * Although using -(pagesz) as mmap hint works on newer kernel as you would |
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893 * think, older variants affected by this work-around don't (search forward only). |
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894 * |
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895 * On the affected distributions, we understand the memory layout to be: |
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896 * |
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897 * TASK_LIMIT= 3G, main stack base close to TASK_LIMT. |
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898 * |
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899 * A few pages south main stack will do it. |
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900 * |
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901 * If we are embedded in an app other than launcher (initial != main stack), |
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902 * we don't have much control or understanding of the address space, just let it slide. |
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903 */ |
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904 char* hint = (char*) (Linux::initial_thread_stack_bottom() - |
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905 ((StackYellowPages + StackRedPages + 1) * page_size)); |
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906 char* codebuf = os::reserve_memory(page_size, hint); |
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907 if ( (codebuf == NULL) || (!os::commit_memory(codebuf, page_size, true)) ) { |
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908 return; // No matter, we tried, best effort. |
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909 } |
14300
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910 |
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911 MemTracker::record_virtual_memory_type((address)codebuf, mtInternal); |
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912 |
12313
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913 if (PrintMiscellaneous && (Verbose || WizardMode)) { |
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914 tty->print_cr("[CS limit NX emulation work-around, exec code at: %p]", codebuf); |
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915 } |
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916 |
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917 // Some code to exec: the 'ret' instruction |
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918 codebuf[0] = 0xC3; |
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919 |
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920 // Call the code in the codebuf |
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921 __asm__ volatile("call *%0" : : "r"(codebuf)); |
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922 |
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923 // keep the page mapped so CS limit isn't reduced. |
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924 #endif |
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925 } |