os_linux_zero.cpp revision 3701:bf2edd3c9b0f
1/*
2 * Copyright (c) 2003, 2011, 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/timer.hpp"
53#include "thread_linux.inline.hpp"
54#include "utilities/events.hpp"
55#include "utilities/vmError.hpp"
56
57address os::current_stack_pointer() {
58  address dummy = (address) &dummy;
59  return dummy;
60}
61
62frame os::get_sender_for_C_frame(frame* fr) {
63  ShouldNotCallThis();
64}
65
66frame 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
81char* 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
95void os::initialize_thread(Thread * thr){
96  // Nothing to do.
97}
98
99address os::Linux::ucontext_get_pc(ucontext_t* uc) {
100  ShouldNotCallThis();
101}
102
103ExtendedPC os::fetch_frame_from_context(void* ucVoid,
104                                        intptr_t** ret_sp,
105                                        intptr_t** ret_fp) {
106  ShouldNotCallThis();
107}
108
109frame os::fetch_frame_from_context(void* ucVoid) {
110  ShouldNotCallThis();
111}
112
113extern "C" JNIEXPORT int
114JVM_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
257void os::Linux::init_thread_fpu_state(void) {
258  // Nothing to do
259}
260
261int os::Linux::get_fpu_control_word() {
262  ShouldNotCallThis();
263}
264
265void os::Linux::set_fpu_control_word(int fpu) {
266  ShouldNotCallThis();
267}
268
269bool 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
290size_t os::Linux::min_stack_allowed = 64 * K;
291
292bool os::Linux::supports_variable_stack_size() {
293  return true;
294}
295
296size_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
305size_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
311static 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, "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
379address os::current_stack_base() {
380  address bottom;
381  size_t size;
382  current_stack_region(&bottom, &size);
383  return bottom + size;
384}
385
386size_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
397void os::print_context(outputStream* st, void* context) {
398  ShouldNotCallThis();
399}
400
401void 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
409extern "C" {
410  int SpinPause() {
411  }
412
413  int SafeFetch32(int *adr, int errValue) {
414    int value = errValue;
415    value = *adr;
416    return value;
417  }
418  intptr_t SafeFetchN(intptr_t *adr, intptr_t errValue) {
419    intptr_t value = errValue;
420    value = *adr;
421    return value;
422  }
423
424  void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
425    if (from > to) {
426      jshort *end = from + count;
427      while (from < end)
428        *(to++) = *(from++);
429    }
430    else if (from < to) {
431      jshort *end = from;
432      from += count - 1;
433      to   += count - 1;
434      while (from >= end)
435        *(to--) = *(from--);
436    }
437  }
438  void _Copy_conjoint_jints_atomic(jint* from, jint* to, size_t count) {
439    if (from > to) {
440      jint *end = from + count;
441      while (from < end)
442        *(to++) = *(from++);
443    }
444    else if (from < to) {
445      jint *end = from;
446      from += count - 1;
447      to   += count - 1;
448      while (from >= end)
449        *(to--) = *(from--);
450    }
451  }
452  void _Copy_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
453    if (from > to) {
454      jlong *end = from + count;
455      while (from < end)
456        os::atomic_copy64(from++, to++);
457    }
458    else if (from < to) {
459      jlong *end = from;
460      from += count - 1;
461      to   += count - 1;
462      while (from >= end)
463        os::atomic_copy64(from--, to--);
464    }
465  }
466
467  void _Copy_arrayof_conjoint_bytes(HeapWord* from,
468                                    HeapWord* to,
469                                    size_t    count) {
470    memmove(to, from, count);
471  }
472  void _Copy_arrayof_conjoint_jshorts(HeapWord* from,
473                                      HeapWord* to,
474                                      size_t    count) {
475    memmove(to, from, count * 2);
476  }
477  void _Copy_arrayof_conjoint_jints(HeapWord* from,
478                                    HeapWord* to,
479                                    size_t    count) {
480    memmove(to, from, count * 4);
481  }
482  void _Copy_arrayof_conjoint_jlongs(HeapWord* from,
483                                     HeapWord* to,
484                                     size_t    count) {
485    memmove(to, from, count * 8);
486  }
487};
488
489/////////////////////////////////////////////////////////////////////////////
490// Implementations of atomic operations not supported by processors.
491//  -- http://gcc.gnu.org/onlinedocs/gcc-4.2.1/gcc/Atomic-Builtins.html
492
493#ifndef _LP64
494extern "C" {
495  long long unsigned int __sync_val_compare_and_swap_8(
496    volatile void *ptr,
497    long long unsigned int oldval,
498    long long unsigned int newval) {
499    ShouldNotCallThis();
500  }
501};
502#endif // !_LP64
503
504#ifndef PRODUCT
505void os::verify_stack_alignment() {
506}
507#endif
508