os_linux_zero.cpp revision 7996:3eb61269f421 
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
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
103void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) {
104  ShouldNotCallThis();
105}
106
107ExtendedPC os::fetch_frame_from_context(void* ucVoid,
108                                        intptr_t** ret_sp,
109                                        intptr_t** ret_fp) {
110  ShouldNotCallThis();
111}
112
113frame os::fetch_frame_from_context(void* ucVoid) {
114  ShouldNotCallThis();
115}
116
117extern "C" JNIEXPORT int
118JVM_handle_linux_signal(int sig,
119                        siginfo_t* info,
120                        void* ucVoid,
121                        int abort_if_unrecognized) {
122  ucontext_t* uc = (ucontext_t*) ucVoid;
123
124  Thread* t = ThreadLocalStorage::get_thread_slow();
125
126  SignalHandlerMark shm(t);
127
128  // Note: it's not uncommon that JNI code uses signal/sigset to
129  // install then restore certain signal handler (e.g. to temporarily
130  // block SIGPIPE, or have a SIGILL handler when detecting CPU
131  // type). When that happens, JVM_handle_linux_signal() might be
132  // invoked with junk info/ucVoid. To avoid unnecessary crash when
133  // libjsig is not preloaded, try handle signals that do not require
134  // siginfo/ucontext first.
135
136  if (sig == SIGPIPE || sig == SIGXFSZ) {
137    // allow chained handler to go first
138    if (os::Linux::chained_handler(sig, info, ucVoid)) {
139      return true;
140    } else {
141      if (PrintMiscellaneous && (WizardMode || Verbose)) {
142        char buf[64];
143        warning("Ignoring %s - see bugs 4229104 or 646499219",
144                os::exception_name(sig, buf, sizeof(buf)));
145      }
146      return true;
147    }
148  }
149
150  JavaThread* thread = NULL;
151  VMThread* vmthread = NULL;
152  if (os::Linux::signal_handlers_are_installed) {
153    if (t != NULL ){
154      if(t->is_Java_thread()) {
155        thread = (JavaThread*)t;
156      }
157      else if(t->is_VM_thread()){
158        vmthread = (VMThread *)t;
159      }
160    }
161  }
162
163  if (info != NULL && thread != NULL) {
164    // Handle ALL stack overflow variations here
165    if (sig == SIGSEGV) {
166      address addr = (address) info->si_addr;
167
168      // check if fault address is within thread stack
169      if (addr < thread->stack_base() &&
170          addr >= thread->stack_base() - thread->stack_size()) {
171        // stack overflow
172        if (thread->in_stack_yellow_zone(addr)) {
173          thread->disable_stack_yellow_zone();
174          ShouldNotCallThis();
175        }
176        else if (thread->in_stack_red_zone(addr)) {
177          thread->disable_stack_red_zone();
178          ShouldNotCallThis();
179        }
180        else {
181          // Accessing stack address below sp may cause SEGV if
182          // current thread has MAP_GROWSDOWN stack. This should
183          // only happen when current thread was created by user
184          // code with MAP_GROWSDOWN flag and then attached to VM.
185          // See notes in os_linux.cpp.
186          if (thread->osthread()->expanding_stack() == 0) {
187            thread->osthread()->set_expanding_stack();
188            if (os::Linux::manually_expand_stack(thread, addr)) {
189              thread->osthread()->clear_expanding_stack();
190              return true;
191            }
192            thread->osthread()->clear_expanding_stack();
193          }
194          else {
195            fatal("recursive segv. expanding stack.");
196          }
197        }
198      }
199    }
200
201    /*if (thread->thread_state() == _thread_in_Java) {
202      ShouldNotCallThis();
203    }
204    else*/ if (thread->thread_state() == _thread_in_vm &&
205               sig == SIGBUS && thread->doing_unsafe_access()) {
206      ShouldNotCallThis();
207    }
208
209    // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC
210    // kicks in and the heap gets shrunk before the field access.
211    /*if (sig == SIGSEGV || sig == SIGBUS) {
212      address addr = JNI_FastGetField::find_slowcase_pc(pc);
213      if (addr != (address)-1) {
214        stub = addr;
215      }
216    }*/
217
218    // Check to see if we caught the safepoint code in the process
219    // of write protecting the memory serialization page.  It write
220    // enables the page immediately after protecting it so we can
221    // just return to retry the write.
222    if (sig == SIGSEGV &&
223        os::is_memory_serialize_page(thread, (address) info->si_addr)) {
224      // Block current thread until permission is restored.
225      os::block_on_serialize_page_trap();
226      return true;
227    }
228  }
229
230  // signal-chaining
231  if (os::Linux::chained_handler(sig, info, ucVoid)) {
232     return true;
233  }
234
235  if (!abort_if_unrecognized) {
236    // caller wants another chance, so give it to him
237    return false;
238  }
239
240#ifndef PRODUCT
241  if (sig == SIGSEGV) {
242    fatal("\n#"
243          "\n#    /--------------------\\"
244          "\n#    | segmentation fault |"
245          "\n#    \\---\\ /--------------/"
246          "\n#        /"
247          "\n#    [-]        |\\_/|    "
248          "\n#    (+)=C      |o o|__  "
249          "\n#    | |        =-*-=__\\ "
250          "\n#    OOO        c_c_(___)");
251  }
252#endif // !PRODUCT
253
254  const char *fmt = "caught unhandled signal %d";
255  char buf[64];
256
257  sprintf(buf, fmt, sig);
258  fatal(buf);
259}
260
261void os::Linux::init_thread_fpu_state(void) {
262  // Nothing to do
263}
264
265int os::Linux::get_fpu_control_word() {
266  ShouldNotCallThis();
267}
268
269void os::Linux::set_fpu_control_word(int fpu) {
270  ShouldNotCallThis();
271}
272
273bool os::is_allocatable(size_t bytes) {
274#ifdef _LP64
275  return true;
276#else
277  if (bytes < 2 * G) {
278    return true;
279  }
280
281  char* addr = reserve_memory(bytes, NULL);
282
283  if (addr != NULL) {
284    release_memory(addr, bytes);
285  }
286
287  return addr != NULL;
288#endif // _LP64
289}
290
291///////////////////////////////////////////////////////////////////////////////
292// thread stack
293
294size_t os::Linux::min_stack_allowed = 64 * K;
295
296bool os::Linux::supports_variable_stack_size() {
297  return true;
298}
299
300size_t os::Linux::default_stack_size(os::ThreadType thr_type) {
301#ifdef _LP64
302  size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
303#else
304  size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
305#endif // _LP64
306  return s;
307}
308
309size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
310  // Only enable glibc guard pages for non-Java threads
311  // (Java threads have HotSpot guard pages)
312  return (thr_type == java_thread ? 0 : page_size());
313}
314
315static void current_stack_region(address *bottom, size_t *size) {
316  pthread_attr_t attr;
317  int res = pthread_getattr_np(pthread_self(), &attr);
318  if (res != 0) {
319    if (res == ENOMEM) {
320      vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
321    }
322    else {
323      fatal(err_msg("pthread_getattr_np failed with errno = %d", res));
324    }
325  }
326
327  address stack_bottom;
328  size_t stack_bytes;
329  res = pthread_attr_getstack(&attr, (void **) &stack_bottom, &stack_bytes);
330  if (res != 0) {
331    fatal(err_msg("pthread_attr_getstack failed with errno = %d", res));
332  }
333  address stack_top = stack_bottom + stack_bytes;
334
335  // The block of memory returned by pthread_attr_getstack() includes
336  // guard pages where present.  We need to trim these off.
337  size_t page_bytes = os::Linux::page_size();
338  assert(((intptr_t) stack_bottom & (page_bytes - 1)) == 0, "unaligned stack");
339
340  size_t guard_bytes;
341  res = pthread_attr_getguardsize(&attr, &guard_bytes);
342  if (res != 0) {
343    fatal(err_msg("pthread_attr_getguardsize failed with errno = %d", res));
344  }
345  int guard_pages = align_size_up(guard_bytes, page_bytes) / page_bytes;
346  assert(guard_bytes == guard_pages * page_bytes, "unaligned guard");
347
348#ifdef IA64
349  // IA64 has two stacks sharing the same area of memory, a normal
350  // stack growing downwards and a register stack growing upwards.
351  // Guard pages, if present, are in the centre.  This code splits
352  // the stack in two even without guard pages, though in theory
353  // there's nothing to stop us allocating more to the normal stack
354  // or more to the register stack if one or the other were found
355  // to grow faster.
356  int total_pages = align_size_down(stack_bytes, page_bytes) / page_bytes;
357  stack_bottom += (total_pages - guard_pages) / 2 * page_bytes;
358#endif // IA64
359
360  stack_bottom += guard_bytes;
361
362  pthread_attr_destroy(&attr);
363
364  // The initial thread has a growable stack, and the size reported
365  // by pthread_attr_getstack is the maximum size it could possibly
366  // be given what currently mapped.  This can be huge, so we cap it.
367  if (os::Linux::is_initial_thread()) {
368    stack_bytes = stack_top - stack_bottom;
369
370    if (stack_bytes > JavaThread::stack_size_at_create())
371      stack_bytes = JavaThread::stack_size_at_create();
372
373    stack_bottom = stack_top - stack_bytes;
374  }
375
376  assert(os::current_stack_pointer() >= stack_bottom, "should do");
377  assert(os::current_stack_pointer() < stack_top, "should do");
378
379  *bottom = stack_bottom;
380  *size = stack_top - stack_bottom;
381}
382
383address os::current_stack_base() {
384  address bottom;
385  size_t size;
386  current_stack_region(&bottom, &size);
387  return bottom + size;
388}
389
390size_t os::current_stack_size() {
391  // stack size includes normal stack and HotSpot guard pages
392  address bottom;
393  size_t size;
394  current_stack_region(&bottom, &size);
395  return size;
396}
397
398/////////////////////////////////////////////////////////////////////////////
399// helper functions for fatal error handler
400
401void os::print_context(outputStream* st, void* context) {
402  ShouldNotCallThis();
403}
404
405void os::print_register_info(outputStream *st, void *context) {
406  ShouldNotCallThis();
407}
408
409/////////////////////////////////////////////////////////////////////////////
410// Stubs for things that would be in linux_zero.s if it existed.
411// You probably want to disassemble these monkeys to check they're ok.
412
413extern "C" {
414  int SpinPause() {
415  }
416
417
418  void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
419    if (from > to) {
420      jshort *end = from + count;
421      while (from < end)
422        *(to++) = *(from++);
423    }
424    else if (from < to) {
425      jshort *end = from;
426      from += count - 1;
427      to   += count - 1;
428      while (from >= end)
429        *(to--) = *(from--);
430    }
431  }
432  void _Copy_conjoint_jints_atomic(jint* from, jint* to, size_t count) {
433    if (from > to) {
434      jint *end = from + count;
435      while (from < end)
436        *(to++) = *(from++);
437    }
438    else if (from < to) {
439      jint *end = from;
440      from += count - 1;
441      to   += count - 1;
442      while (from >= end)
443        *(to--) = *(from--);
444    }
445  }
446  void _Copy_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
447    if (from > to) {
448      jlong *end = from + count;
449      while (from < end)
450        os::atomic_copy64(from++, to++);
451    }
452    else if (from < to) {
453      jlong *end = from;
454      from += count - 1;
455      to   += count - 1;
456      while (from >= end)
457        os::atomic_copy64(from--, to--);
458    }
459  }
460
461  void _Copy_arrayof_conjoint_bytes(HeapWord* from,
462                                    HeapWord* to,
463                                    size_t    count) {
464    memmove(to, from, count);
465  }
466  void _Copy_arrayof_conjoint_jshorts(HeapWord* from,
467                                      HeapWord* to,
468                                      size_t    count) {
469    memmove(to, from, count * 2);
470  }
471  void _Copy_arrayof_conjoint_jints(HeapWord* from,
472                                    HeapWord* to,
473                                    size_t    count) {
474    memmove(to, from, count * 4);
475  }
476  void _Copy_arrayof_conjoint_jlongs(HeapWord* from,
477                                     HeapWord* to,
478                                     size_t    count) {
479    memmove(to, from, count * 8);
480  }
481};
482
483/////////////////////////////////////////////////////////////////////////////
484// Implementations of atomic operations not supported by processors.
485//  -- http://gcc.gnu.org/onlinedocs/gcc-4.2.1/gcc/Atomic-Builtins.html
486
487#ifndef _LP64
488extern "C" {
489  long long unsigned int __sync_val_compare_and_swap_8(
490    volatile void *ptr,
491    long long unsigned int oldval,
492    long long unsigned int newval) {
493    ShouldNotCallThis();
494  }
495};
496#endif // !_LP64
497
498#ifndef PRODUCT
499void os::verify_stack_alignment() {
500}
501#endif
502
503int os::extra_bang_size_in_bytes() {
504  // Zero does not require an additional stack banging.
505  return 0;
506}
507