1 /*
2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
3 * Copyright 2007, 2008, 2009, 2010 Red Hat, Inc.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 // no precompiled headers
27 #include "assembler_zero.inline.hpp"
28 #include "classfile/classLoader.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "code/icBuffer.hpp"
32 #include "code/vtableStubs.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "jvm_linux.h"
35 #include "memory/allocation.inline.hpp"
36 #include "mutex_linux.inline.hpp"
37 #include "nativeInst_zero.hpp"
38 #include "os_share_linux.hpp"
39 #include "prims/jniFastGetField.hpp"
40 #include "prims/jvm.h"
41 #include "prims/jvm_misc.hpp"
42 #include "runtime/arguments.hpp"
43 #include "runtime/extendedPC.hpp"
44 #include "runtime/frame.inline.hpp"
45 #include "runtime/hpi.hpp"
46 #include "runtime/interfaceSupport.hpp"
47 #include "runtime/java.hpp"
48 #include "runtime/javaCalls.hpp"
49 #include "runtime/mutexLocker.hpp"
50 #include "runtime/osThread.hpp"
51 #include "runtime/sharedRuntime.hpp"
52 #include "runtime/stubRoutines.hpp"
53 #include "runtime/timer.hpp"
54 #include "thread_linux.inline.hpp"
55 #include "utilities/events.hpp"
56 #include "utilities/vmError.hpp"
57 #ifdef COMPILER1
58 #include "c1/c1_Runtime1.hpp"
59 #endif
60 #ifdef COMPILER2
61 #include "opto/runtime.hpp"
62 #endif
63
64 address os::current_stack_pointer() {
65 address dummy = (address) &dummy;
66 return dummy;
67 }
68
69 frame os::get_sender_for_C_frame(frame* fr) {
70 ShouldNotCallThis();
71 }
72
73 frame os::current_frame() {
74 // The only thing that calls this is the stack printing code in
75 // VMError::report:
76 // - Step 110 (printing stack bounds) uses the sp in the frame
77 // to determine the amount of free space on the stack. We
78 // set the sp to a close approximation of the real value in
79 // order to allow this step to complete.
80 // - Step 120 (printing native stack) tries to walk the stack.
81 // The frame we create has a NULL pc, which is ignored as an
82 // invalid frame.
83 frame dummy = frame();
84 dummy.set_sp((intptr_t *) current_stack_pointer());
85 return dummy;
86 }
87
88 char* os::non_memory_address_word() {
89 // Must never look like an address returned by reserve_memory,
90 // even in its subfields (as defined by the CPU immediate fields,
91 // if the CPU splits constants across multiple instructions).
92 #ifdef SPARC
93 // On SPARC, 0 != %hi(any real address), because there is no
94 // allocation in the first 1Kb of the virtual address space.
95 return (char *) 0;
96 #else
97 // This is the value for x86; works pretty well for PPC too.
98 return (char *) -1;
99 #endif // SPARC
100 }
101
102 void os::initialize_thread() {
103 // Nothing to do.
104 }
105
106 address os::Linux::ucontext_get_pc(ucontext_t* uc) {
107 ShouldNotCallThis();
108 }
109
110 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
111 intptr_t** ret_sp,
112 intptr_t** ret_fp) {
113 ShouldNotCallThis();
114 }
115
116 frame os::fetch_frame_from_context(void* ucVoid) {
117 ShouldNotCallThis();
118 }
119
120 extern "C" int
121 JVM_handle_linux_signal(int sig,
122 siginfo_t* info,
123 void* ucVoid,
124 int abort_if_unrecognized) {
125 ucontext_t* uc = (ucontext_t*) ucVoid;
126
127 Thread* t = ThreadLocalStorage::get_thread_slow();
128
129 SignalHandlerMark shm(t);
130
131 // Note: it's not uncommon that JNI code uses signal/sigset to
132 // install then restore certain signal handler (e.g. to temporarily
133 // block SIGPIPE, or have a SIGILL handler when detecting CPU
134 // type). When that happens, JVM_handle_linux_signal() might be
135 // invoked with junk info/ucVoid. To avoid unnecessary crash when
136 // libjsig is not preloaded, try handle signals that do not require
137 // siginfo/ucontext first.
138
139 if (sig == SIGPIPE || sig == SIGXFSZ) {
140 // allow chained handler to go first
141 if (os::Linux::chained_handler(sig, info, ucVoid)) {
142 return true;
143 } else {
144 if (PrintMiscellaneous && (WizardMode || Verbose)) {
145 char buf[64];
146 warning("Ignoring %s - see bugs 4229104 or 646499219",
147 os::exception_name(sig, buf, sizeof(buf)));
148 }
149 return true;
150 }
151 }
152
153 JavaThread* thread = NULL;
154 VMThread* vmthread = NULL;
155 if (os::Linux::signal_handlers_are_installed) {
156 if (t != NULL ){
157 if(t->is_Java_thread()) {
158 thread = (JavaThread*)t;
159 }
160 else if(t->is_VM_thread()){
161 vmthread = (VMThread *)t;
162 }
163 }
164 }
165
166 if (info != NULL && thread != NULL) {
167 // Handle ALL stack overflow variations here
168 if (sig == SIGSEGV) {
169 address addr = (address) info->si_addr;
170
171 // check if fault address is within thread stack
172 if (addr < thread->stack_base() &&
173 addr >= thread->stack_base() - thread->stack_size()) {
174 // stack overflow
175 if (thread->in_stack_yellow_zone(addr)) {
176 thread->disable_stack_yellow_zone();
177 ShouldNotCallThis();
178 }
179 else if (thread->in_stack_red_zone(addr)) {
180 thread->disable_stack_red_zone();
181 ShouldNotCallThis();
182 }
183 else {
184 // Accessing stack address below sp may cause SEGV if
185 // current thread has MAP_GROWSDOWN stack. This should
186 // only happen when current thread was created by user
187 // code with MAP_GROWSDOWN flag and then attached to VM.
188 // See notes in os_linux.cpp.
189 if (thread->osthread()->expanding_stack() == 0) {
190 thread->osthread()->set_expanding_stack();
191 if (os::Linux::manually_expand_stack(thread, addr)) {
192 thread->osthread()->clear_expanding_stack();
193 return true;
194 }
195 thread->osthread()->clear_expanding_stack();
196 }
197 else {
198 fatal("recursive segv. expanding stack.");
199 }
200 }
201 }
202 }
203
204 /*if (thread->thread_state() == _thread_in_Java) {
205 ShouldNotCallThis();
206 }
207 else*/ if (thread->thread_state() == _thread_in_vm &&
208 sig == SIGBUS && thread->doing_unsafe_access()) {
209 ShouldNotCallThis();
210 }
211
212 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC
213 // kicks in and the heap gets shrunk before the field access.
214 /*if (sig == SIGSEGV || sig == SIGBUS) {
215 address addr = JNI_FastGetField::find_slowcase_pc(pc);
216 if (addr != (address)-1) {
217 stub = addr;
218 }
219 }*/
220
221 // Check to see if we caught the safepoint code in the process
222 // of write protecting the memory serialization page. It write
223 // enables the page immediately after protecting it so we can
224 // just return to retry the write.
225 if (sig == SIGSEGV &&
226 os::is_memory_serialize_page(thread, (address) info->si_addr)) {
227 // Block current thread until permission is restored.
228 os::block_on_serialize_page_trap();
229 return true;
230 }
231 }
232
233 // signal-chaining
234 if (os::Linux::chained_handler(sig, info, ucVoid)) {
235 return true;
236 }
237
238 if (!abort_if_unrecognized) {
239 // caller wants another chance, so give it to him
240 return false;
241 }
242
243 #ifndef PRODUCT
244 if (sig == SIGSEGV) {
245 fatal("\n#"
246 "\n# /--------------------\\"
247 "\n# | segmentation fault |"
248 "\n# \\---\\ /--------------/"
249 "\n# /"
250 "\n# [-] |\\_/| "
251 "\n# (+)=C |o o|__ "
252 "\n# | | =-*-=__\\ "
253 "\n# OOO c_c_(___)");
254 }
255 #endif // !PRODUCT
256
257 const char *fmt = "caught unhandled signal %d";
258 char buf[64];
259
260 sprintf(buf, fmt, sig);
261 fatal(buf);
262 }
263
264 void os::Linux::init_thread_fpu_state(void) {
265 // Nothing to do
266 }
267
268 int os::Linux::get_fpu_control_word() {
269 ShouldNotCallThis();
270 }
271
272 void os::Linux::set_fpu_control_word(int fpu) {
273 ShouldNotCallThis();
274 }
275
276 bool os::is_allocatable(size_t bytes) {
277 #ifdef _LP64
278 return true;
279 #else
280 if (bytes < 2 * G) {
281 return true;
282 }
283
284 char* addr = reserve_memory(bytes, NULL);
285
286 if (addr != NULL) {
287 release_memory(addr, bytes);
288 }
289
290 return addr != NULL;
291 #endif // _LP64
292 }
293
294 ///////////////////////////////////////////////////////////////////////////////
295 // thread stack
296
297 size_t os::Linux::min_stack_allowed = 64 * K;
298
299 bool os::Linux::supports_variable_stack_size() {
300 return true;
301 }
302
303 size_t os::Linux::default_stack_size(os::ThreadType thr_type) {
304 #ifdef _LP64
305 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
306 #else
307 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
308 #endif // _LP64
309 return s;
310 }
311
312 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
313 // Only enable glibc guard pages for non-Java threads
314 // (Java threads have HotSpot guard pages)
315 return (thr_type == java_thread ? 0 : page_size());
316 }
317
318 static void current_stack_region(address *bottom, size_t *size) {
319 pthread_attr_t attr;
320 int res = pthread_getattr_np(pthread_self(), &attr);
321 if (res != 0) {
322 if (res == ENOMEM) {
323 vm_exit_out_of_memory(0, "pthread_getattr_np");
324 }
325 else {
326 fatal(err_msg("pthread_getattr_np failed with errno = %d", res));
327 }
328 }
329
330 address stack_bottom;
331 size_t stack_bytes;
332 res = pthread_attr_getstack(&attr, (void **) &stack_bottom, &stack_bytes);
333 if (res != 0) {
334 fatal(err_msg("pthread_attr_getstack failed with errno = %d", res));
335 }
336 address stack_top = stack_bottom + stack_bytes;
337
338 // The block of memory returned by pthread_attr_getstack() includes
339 // guard pages where present. We need to trim these off.
340 size_t page_bytes = os::Linux::page_size();
341 assert(((intptr_t) stack_bottom & (page_bytes - 1)) == 0, "unaligned stack");
342
343 size_t guard_bytes;
344 res = pthread_attr_getguardsize(&attr, &guard_bytes);
345 if (res != 0) {
346 fatal(err_msg("pthread_attr_getguardsize failed with errno = %d", res));
347 }
348 int guard_pages = align_size_up(guard_bytes, page_bytes) / page_bytes;
349 assert(guard_bytes == guard_pages * page_bytes, "unaligned guard");
350
351 #ifdef IA64
352 // IA64 has two stacks sharing the same area of memory, a normal
353 // stack growing downwards and a register stack growing upwards.
354 // Guard pages, if present, are in the centre. This code splits
355 // the stack in two even without guard pages, though in theory
356 // there's nothing to stop us allocating more to the normal stack
357 // or more to the register stack if one or the other were found
358 // to grow faster.
359 int total_pages = align_size_down(stack_bytes, page_bytes) / page_bytes;
360 stack_bottom += (total_pages - guard_pages) / 2 * page_bytes;
361 #endif // IA64
362
363 stack_bottom += guard_bytes;
364
365 pthread_attr_destroy(&attr);
366
367 // The initial thread has a growable stack, and the size reported
368 // by pthread_attr_getstack is the maximum size it could possibly
369 // be given what currently mapped. This can be huge, so we cap it.
370 if (os::Linux::is_initial_thread()) {
371 stack_bytes = stack_top - stack_bottom;
372
373 if (stack_bytes > JavaThread::stack_size_at_create())
374 stack_bytes = JavaThread::stack_size_at_create();
375
376 stack_bottom = stack_top - stack_bytes;
377 }
378
379 assert(os::current_stack_pointer() >= stack_bottom, "should do");
380 assert(os::current_stack_pointer() < stack_top, "should do");
381
382 *bottom = stack_bottom;
383 *size = stack_top - stack_bottom;
384 }
385
386 address os::current_stack_base() {
387 address bottom;
388 size_t size;
389 current_stack_region(&bottom, &size);
390 return bottom + size;
391 }
392
393 size_t os::current_stack_size() {
394 // stack size includes normal stack and HotSpot guard pages
395 address bottom;
396 size_t size;
397 current_stack_region(&bottom, &size);
398 return size;
399 }
400
401 /////////////////////////////////////////////////////////////////////////////
402 // helper functions for fatal error handler
403
404 void os::print_context(outputStream* st, void* context) {
405 ShouldNotCallThis();
406 }
407
408 /////////////////////////////////////////////////////////////////////////////
409 // Stubs for things that would be in linux_zero.s if it existed.
410 // You probably want to disassemble these monkeys to check they're ok.
411
412 extern "C" {
413 int SpinPause() {
414 }
415
416 int SafeFetch32(int *adr, int errValue) {
417 int value = errValue;
418 value = *adr;
419 return value;
420 }
421 intptr_t SafeFetchN(intptr_t *adr, intptr_t errValue) {
422 intptr_t value = errValue;
423 value = *adr;
424 return value;
425 }
426
427 void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
428 if (from > to) {
429 jshort *end = from + count;
430 while (from < end)
431 *(to++) = *(from++);
432 }
433 else if (from < to) {
434 jshort *end = from;
435 from += count - 1;
436 to += count - 1;
437 while (from >= end)
438 *(to--) = *(from--);
439 }
440 }
441 void _Copy_conjoint_jints_atomic(jint* from, jint* to, size_t count) {
442 if (from > to) {
443 jint *end = from + count;
444 while (from < end)
445 *(to++) = *(from++);
446 }
447 else if (from < to) {
448 jint *end = from;
449 from += count - 1;
450 to += count - 1;
451 while (from >= end)
452 *(to--) = *(from--);
453 }
454 }
455 void _Copy_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
456 if (from > to) {
457 jlong *end = from + count;
458 while (from < end)
459 os::atomic_copy64(from++, to++);
460 }
461 else if (from < to) {
462 jlong *end = from;
463 from += count - 1;
464 to += count - 1;
465 while (from >= end)
466 os::atomic_copy64(from--, to--);
467 }
468 }
469
470 void _Copy_arrayof_conjoint_bytes(HeapWord* from,
471 HeapWord* to,
472 size_t count) {
473 memmove(to, from, count);
474 }
475 void _Copy_arrayof_conjoint_jshorts(HeapWord* from,
476 HeapWord* to,
477 size_t count) {
478 memmove(to, from, count * 2);
479 }
480 void _Copy_arrayof_conjoint_jints(HeapWord* from,
481 HeapWord* to,
482 size_t count) {
483 memmove(to, from, count * 4);
484 }
485 void _Copy_arrayof_conjoint_jlongs(HeapWord* from,
486 HeapWord* to,
487 size_t count) {
488 memmove(to, from, count * 8);
489 }
490 };
491
492 /////////////////////////////////////////////////////////////////////////////
493 // Implementations of atomic operations not supported by processors.
494 // -- http://gcc.gnu.org/onlinedocs/gcc-4.2.1/gcc/Atomic-Builtins.html
495
496 #ifndef _LP64
497 extern "C" {
498 long long unsigned int __sync_val_compare_and_swap_8(
499 volatile void *ptr,
500 long long unsigned int oldval,
501 long long unsigned int newval) {
502 ShouldNotCallThis();
503 }
504 };
505 #endif // !_LP64