1 /*
2 * Copyright (c) 2003, 2013, 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/interfaceSupport.hpp"
46 #include "runtime/java.hpp"
47 #include "runtime/javaCalls.hpp"
48 #include "runtime/mutexLocker.hpp"
49 #include "runtime/osThread.hpp"
50 #include "runtime/sharedRuntime.hpp"
51 #include "runtime/stubRoutines.hpp"
52 #include "runtime/thread.inline.hpp"
53 #include "runtime/timer.hpp"
54 #include "utilities/events.hpp"
55 #include "utilities/vmError.hpp"
56
57 address os::current_stack_pointer() {
58 address dummy = (address) &dummy;
59 return dummy;
60 }
61
62 frame os::get_sender_for_C_frame(frame* fr) {
63 ShouldNotCallThis();
64 }
65
66 frame os::current_frame() {
67 // The only thing that calls this is the stack printing code in
68 // VMError::report:
69 // - Step 110 (printing stack bounds) uses the sp in the frame
70 // to determine the amount of free space on the stack. We
71 // set the sp to a close approximation of the real value in
72 // order to allow this step to complete.
73 // - Step 120 (printing native stack) tries to walk the stack.
74 // The frame we create has a NULL pc, which is ignored as an
75 // invalid frame.
76 frame dummy = frame();
77 dummy.set_sp((intptr_t *) current_stack_pointer());
78 return dummy;
79 }
80
81 char* os::non_memory_address_word() {
82 // Must never look like an address returned by reserve_memory,
83 // even in its subfields (as defined by the CPU immediate fields,
84 // if the CPU splits constants across multiple instructions).
85 #ifdef SPARC
86 // On SPARC, 0 != %hi(any real address), because there is no
87 // allocation in the first 1Kb of the virtual address space.
88 return (char *) 0;
89 #else
90 // This is the value for x86; works pretty well for PPC too.
91 return (char *) -1;
92 #endif // SPARC
93 }
94
95 void os::initialize_thread(Thread * thr){
96 // Nothing to do.
97 }
98
99 address os::Linux::ucontext_get_pc(ucontext_t* uc) {
100 ShouldNotCallThis();
101 }
102
103 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
104 intptr_t** ret_sp,
105 intptr_t** ret_fp) {
106 ShouldNotCallThis();
107 }
108
109 frame os::fetch_frame_from_context(void* ucVoid) {
110 ShouldNotCallThis();
111 }
112
113 extern "C" JNIEXPORT int
114 JVM_handle_linux_signal(int sig,
115 siginfo_t* info,
116 void* ucVoid,
117 int abort_if_unrecognized) {
118 ucontext_t* uc = (ucontext_t*) ucVoid;
119
120 Thread* t = ThreadLocalStorage::get_thread_slow();
121
122 SignalHandlerMark shm(t);
123
124 // Note: it's not uncommon that JNI code uses signal/sigset to
125 // install then restore certain signal handler (e.g. to temporarily
126 // block SIGPIPE, or have a SIGILL handler when detecting CPU
127 // type). When that happens, JVM_handle_linux_signal() might be
128 // invoked with junk info/ucVoid. To avoid unnecessary crash when
129 // libjsig is not preloaded, try handle signals that do not require
130 // siginfo/ucontext first.
131
132 if (sig == SIGPIPE || sig == SIGXFSZ) {
133 // allow chained handler to go first
134 if (os::Linux::chained_handler(sig, info, ucVoid)) {
135 return true;
136 } else {
137 if (PrintMiscellaneous && (WizardMode || Verbose)) {
138 char buf[64];
139 warning("Ignoring %s - see bugs 4229104 or 646499219",
140 os::exception_name(sig, buf, sizeof(buf)));
141 }
142 return true;
143 }
144 }
145
146 JavaThread* thread = NULL;
147 VMThread* vmthread = NULL;
148 if (os::Linux::signal_handlers_are_installed) {
149 if (t != NULL ){
150 if(t->is_Java_thread()) {
151 thread = (JavaThread*)t;
152 }
153 else if(t->is_VM_thread()){
154 vmthread = (VMThread *)t;
155 }
156 }
157 }
158
159 if (info != NULL && thread != NULL) {
160 // Handle ALL stack overflow variations here
161 if (sig == SIGSEGV) {
162 address addr = (address) info->si_addr;
163
164 // check if fault address is within thread stack
165 if (addr < thread->stack_base() &&
166 addr >= thread->stack_base() - thread->stack_size()) {
167 // stack overflow
168 if (thread->in_stack_yellow_zone(addr)) {
169 thread->disable_stack_yellow_zone();
170 ShouldNotCallThis();
171 }
172 else if (thread->in_stack_red_zone(addr)) {
173 thread->disable_stack_red_zone();
174 ShouldNotCallThis();
175 }
176 else {
177 // Accessing stack address below sp may cause SEGV if
178 // current thread has MAP_GROWSDOWN stack. This should
179 // only happen when current thread was created by user
180 // code with MAP_GROWSDOWN flag and then attached to VM.
181 // See notes in os_linux.cpp.
182 if (thread->osthread()->expanding_stack() == 0) {
183 thread->osthread()->set_expanding_stack();
184 if (os::Linux::manually_expand_stack(thread, addr)) {
185 thread->osthread()->clear_expanding_stack();
186 return true;
187 }
188 thread->osthread()->clear_expanding_stack();
189 }
190 else {
191 fatal("recursive segv. expanding stack.");
192 }
193 }
194 }
195 }
196
197 /*if (thread->thread_state() == _thread_in_Java) {
198 ShouldNotCallThis();
199 }
200 else*/ if (thread->thread_state() == _thread_in_vm &&
201 sig == SIGBUS && thread->doing_unsafe_access()) {
202 ShouldNotCallThis();
203 }
204
205 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC
206 // kicks in and the heap gets shrunk before the field access.
207 /*if (sig == SIGSEGV || sig == SIGBUS) {
208 address addr = JNI_FastGetField::find_slowcase_pc(pc);
209 if (addr != (address)-1) {
210 stub = addr;
211 }
212 }*/
213
214 // Check to see if we caught the safepoint code in the process
215 // of write protecting the memory serialization page. It write
216 // enables the page immediately after protecting it so we can
217 // just return to retry the write.
218 if (sig == SIGSEGV &&
219 os::is_memory_serialize_page(thread, (address) info->si_addr)) {
220 // Block current thread until permission is restored.
221 os::block_on_serialize_page_trap();
222 return true;
223 }
224 }
225
226 // signal-chaining
227 if (os::Linux::chained_handler(sig, info, ucVoid)) {
228 return true;
229 }
230
231 if (!abort_if_unrecognized) {
232 // caller wants another chance, so give it to him
233 return false;
234 }
235
236 #ifndef PRODUCT
237 if (sig == SIGSEGV) {
238 fatal("\n#"
239 "\n# /--------------------\\"
240 "\n# | segmentation fault |"
241 "\n# \\---\\ /--------------/"
242 "\n# /"
243 "\n# [-] |\\_/| "
244 "\n# (+)=C |o o|__ "
245 "\n# | | =-*-=__\\ "
246 "\n# OOO c_c_(___)");
247 }
248 #endif // !PRODUCT
249
250 const char *fmt = "caught unhandled signal %d";
251 char buf[64];
252
253 sprintf(buf, fmt, sig);
254 fatal(buf);
255 }
256
257 void os::Linux::init_thread_fpu_state(void) {
258 // Nothing to do
259 }
260
261 int os::Linux::get_fpu_control_word() {
262 ShouldNotCallThis();
263 }
264
265 void os::Linux::set_fpu_control_word(int fpu) {
266 ShouldNotCallThis();
267 }
268
269 bool os::is_allocatable(size_t bytes) {
270 #ifdef _LP64
271 return true;
272 #else
273 if (bytes < 2 * G) {
274 return true;
275 }
276
277 char* addr = reserve_memory(bytes, NULL);
278
279 if (addr != NULL) {
280 release_memory(addr, bytes);
281 }
282
283 return addr != NULL;
284 #endif // _LP64
285 }
286
287 ///////////////////////////////////////////////////////////////////////////////
288 // thread stack
289
290 size_t os::Linux::min_stack_allowed = 64 * K;
291
292 bool os::Linux::supports_variable_stack_size() {
293 return true;
294 }
295
296 size_t os::Linux::default_stack_size(os::ThreadType thr_type) {
297 #ifdef _LP64
298 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
299 #else
300 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
301 #endif // _LP64
302 return s;
303 }
304
305 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
306 // Only enable glibc guard pages for non-Java threads
307 // (Java threads have HotSpot guard pages)
308 return (thr_type == java_thread ? 0 : page_size());
309 }
310
311 static void current_stack_region(address *bottom, size_t *size) {
312 pthread_attr_t attr;
313 int res = pthread_getattr_np(pthread_self(), &attr);
314 if (res != 0) {
315 if (res == ENOMEM) {
316 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
317 }
318 else {
319 fatal(err_msg("pthread_getattr_np failed with errno = %d", res));
320 }
321 }
322
323 address stack_bottom;
324 size_t stack_bytes;
325 res = pthread_attr_getstack(&attr, (void **) &stack_bottom, &stack_bytes);
326 if (res != 0) {
327 fatal(err_msg("pthread_attr_getstack failed with errno = %d", res));
328 }
329 address stack_top = stack_bottom + stack_bytes;
330
331 // The block of memory returned by pthread_attr_getstack() includes
332 // guard pages where present. We need to trim these off.
333 size_t page_bytes = os::Linux::page_size();
334 assert(((intptr_t) stack_bottom & (page_bytes - 1)) == 0, "unaligned stack");
335
336 size_t guard_bytes;
337 res = pthread_attr_getguardsize(&attr, &guard_bytes);
338 if (res != 0) {
339 fatal(err_msg("pthread_attr_getguardsize failed with errno = %d", res));
340 }
341 int guard_pages = align_size_up(guard_bytes, page_bytes) / page_bytes;
342 assert(guard_bytes == guard_pages * page_bytes, "unaligned guard");
343
344 #ifdef IA64
345 // IA64 has two stacks sharing the same area of memory, a normal
346 // stack growing downwards and a register stack growing upwards.
347 // Guard pages, if present, are in the centre. This code splits
348 // the stack in two even without guard pages, though in theory
349 // there's nothing to stop us allocating more to the normal stack
350 // or more to the register stack if one or the other were found
351 // to grow faster.
352 int total_pages = align_size_down(stack_bytes, page_bytes) / page_bytes;
353 stack_bottom += (total_pages - guard_pages) / 2 * page_bytes;
354 #endif // IA64
355
356 stack_bottom += guard_bytes;
357
358 pthread_attr_destroy(&attr);
359
360 // The initial thread has a growable stack, and the size reported
361 // by pthread_attr_getstack is the maximum size it could possibly
362 // be given what currently mapped. This can be huge, so we cap it.
363 if (os::Linux::is_initial_thread()) {
364 stack_bytes = stack_top - stack_bottom;
365
366 if (stack_bytes > JavaThread::stack_size_at_create())
367 stack_bytes = JavaThread::stack_size_at_create();
368
369 stack_bottom = stack_top - stack_bytes;
370 }
371
372 assert(os::current_stack_pointer() >= stack_bottom, "should do");
373 assert(os::current_stack_pointer() < stack_top, "should do");
374
375 *bottom = stack_bottom;
376 *size = stack_top - stack_bottom;
377 }
378
379 address os::current_stack_base() {
380 address bottom;
381 size_t size;
382 current_stack_region(&bottom, &size);
383 return bottom + size;
384 }
385
386 size_t os::current_stack_size() {
387 // stack size includes normal stack and HotSpot guard pages
388 address bottom;
389 size_t size;
390 current_stack_region(&bottom, &size);
391 return size;
392 }
393
394 /////////////////////////////////////////////////////////////////////////////
395 // helper functions for fatal error handler
396
397 void os::print_context(outputStream* st, void* context) {
398 ShouldNotCallThis();
399 }
400
401 void os::print_register_info(outputStream *st, void *context) {
402 ShouldNotCallThis();
403 }
404
405 /////////////////////////////////////////////////////////////////////////////
406 // Stubs for things that would be in linux_zero.s if it existed.
407 // You probably want to disassemble these monkeys to check they're ok.
408
409 extern "C" {
410 int SpinPause() {
411 }
412
413
414 void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
415 if (from > to) {
416 jshort *end = from + count;
417 while (from < end)
418 *(to++) = *(from++);
419 }
420 else if (from < to) {
421 jshort *end = from;
422 from += count - 1;
423 to += count - 1;
424 while (from >= end)
425 *(to--) = *(from--);
426 }
427 }
428 void _Copy_conjoint_jints_atomic(jint* from, jint* to, size_t count) {
429 if (from > to) {
430 jint *end = from + count;
431 while (from < end)
432 *(to++) = *(from++);
433 }
434 else if (from < to) {
435 jint *end = from;
436 from += count - 1;
437 to += count - 1;
438 while (from >= end)
439 *(to--) = *(from--);
440 }
441 }
442 void _Copy_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
443 if (from > to) {
444 jlong *end = from + count;
445 while (from < end)
446 os::atomic_copy64(from++, to++);
447 }
448 else if (from < to) {
449 jlong *end = from;
450 from += count - 1;
451 to += count - 1;
452 while (from >= end)
453 os::atomic_copy64(from--, to--);
454 }
455 }
456
457 void _Copy_arrayof_conjoint_bytes(HeapWord* from,
458 HeapWord* to,
459 size_t count) {
460 memmove(to, from, count);
461 }
462 void _Copy_arrayof_conjoint_jshorts(HeapWord* from,
463 HeapWord* to,
464 size_t count) {
465 memmove(to, from, count * 2);
466 }
467 void _Copy_arrayof_conjoint_jints(HeapWord* from,
468 HeapWord* to,
469 size_t count) {
470 memmove(to, from, count * 4);
471 }
472 void _Copy_arrayof_conjoint_jlongs(HeapWord* from,
473 HeapWord* to,
474 size_t count) {
475 memmove(to, from, count * 8);
476 }
477 };
478
479 /////////////////////////////////////////////////////////////////////////////
480 // Implementations of atomic operations not supported by processors.
481 // -- http://gcc.gnu.org/onlinedocs/gcc-4.2.1/gcc/Atomic-Builtins.html
482
483 #ifndef _LP64
484 extern "C" {
485 long long unsigned int __sync_val_compare_and_swap_8(
486 volatile void *ptr,
487 long long unsigned int oldval,
488 long long unsigned int newval) {
489 ShouldNotCallThis();
490 }
491 };
492 #endif // !_LP64
493
494 #ifndef PRODUCT
495 void os::verify_stack_alignment() {
496 }
497 #endif