1 /*
   2  * Copyright (c) 2003, 2012, 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 #if !defined(__APPLE__) && !defined(__NetBSD__)
  27 #include <pthread.h>
  28 # include <pthread_np.h> /* For pthread_attr_get_np */
  29 #endif
  30 
  31 // no precompiled headers
  32 #include "assembler_zero.inline.hpp"
  33 #include "classfile/classLoader.hpp"
  34 #include "classfile/systemDictionary.hpp"
  35 #include "classfile/vmSymbols.hpp"
  36 #include "code/icBuffer.hpp"
  37 #include "code/vtableStubs.hpp"
  38 #include "interpreter/interpreter.hpp"
  39 #include "jvm_bsd.h"
  40 #include "memory/allocation.inline.hpp"
  41 #include "mutex_bsd.inline.hpp"
  42 #include "nativeInst_zero.hpp"
  43 #include "os_share_bsd.hpp"
  44 #include "prims/jniFastGetField.hpp"
  45 #include "prims/jvm.h"
  46 #include "prims/jvm_misc.hpp"
  47 #include "runtime/arguments.hpp"
  48 #include "runtime/extendedPC.hpp"
  49 #include "runtime/frame.inline.hpp"
  50 #include "runtime/interfaceSupport.hpp"
  51 #include "runtime/java.hpp"
  52 #include "runtime/javaCalls.hpp"
  53 #include "runtime/mutexLocker.hpp"
  54 #include "runtime/osThread.hpp"
  55 #include "runtime/sharedRuntime.hpp"
  56 #include "runtime/stubRoutines.hpp"
  57 #include "runtime/thread.inline.hpp"
  58 #include "runtime/timer.hpp"
  59 #include "utilities/events.hpp"
  60 #include "utilities/vmError.hpp"
  61 
  62 address os::current_stack_pointer() {
  63   address dummy = (address) &dummy;
  64   return dummy;
  65 }
  66 
  67 frame os::get_sender_for_C_frame(frame* fr) {
  68   ShouldNotCallThis();
  69 }
  70 
  71 frame os::current_frame() {
  72   // The only thing that calls this is the stack printing code in
  73   // VMError::report:
  74   //   - Step 110 (printing stack bounds) uses the sp in the frame
  75   //     to determine the amount of free space on the stack.  We
  76   //     set the sp to a close approximation of the real value in
  77   //     order to allow this step to complete.
  78   //   - Step 120 (printing native stack) tries to walk the stack.
  79   //     The frame we create has a NULL pc, which is ignored as an
  80   //     invalid frame.
  81   frame dummy = frame();
  82   dummy.set_sp((intptr_t *) current_stack_pointer());
  83   return dummy;
  84 }
  85 
  86 char* os::non_memory_address_word() {
  87   // Must never look like an address returned by reserve_memory,
  88   // even in its subfields (as defined by the CPU immediate fields,
  89   // if the CPU splits constants across multiple instructions).
  90 #ifdef SPARC
  91   // On SPARC, 0 != %hi(any real address), because there is no
  92   // allocation in the first 1Kb of the virtual address space.
  93   return (char *) 0;
  94 #else
  95   // This is the value for x86; works pretty well for PPC too.
  96   return (char *) -1;
  97 #endif // SPARC
  98 }
  99 
 100 void os::initialize_thread(Thread* thr) {
 101   // Nothing to do.
 102 }
 103 
 104 address os::Bsd::ucontext_get_pc(ucontext_t* uc) {
 105   ShouldNotCallThis();
 106 }
 107 
 108 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
 109                                         intptr_t** ret_sp,
 110                                         intptr_t** ret_fp) {
 111   ShouldNotCallThis();
 112 }
 113 
 114 frame os::fetch_frame_from_context(void* ucVoid) {
 115   ShouldNotCallThis();
 116 }
 117 
 118 extern "C" JNIEXPORT int
 119 JVM_handle_bsd_signal(int sig,
 120                         siginfo_t* info,
 121                         void* ucVoid,
 122                         int abort_if_unrecognized) {
 123   ucontext_t* uc = (ucontext_t*) ucVoid;
 124 
 125   Thread* t = ThreadLocalStorage::get_thread_slow();
 126 
 127   SignalHandlerMark shm(t);
 128 
 129   // Note: it's not uncommon that JNI code uses signal/sigset to
 130   // install then restore certain signal handler (e.g. to temporarily
 131   // block SIGPIPE, or have a SIGILL handler when detecting CPU
 132   // type). When that happens, JVM_handle_bsd_signal() might be
 133   // invoked with junk info/ucVoid. To avoid unnecessary crash when
 134   // libjsig is not preloaded, try handle signals that do not require
 135   // siginfo/ucontext first.
 136 
 137   if (sig == SIGPIPE || sig == SIGXFSZ) {
 138     // allow chained handler to go first
 139     if (os::Bsd::chained_handler(sig, info, ucVoid)) {
 140       return true;
 141     } else {
 142       if (PrintMiscellaneous && (WizardMode || Verbose)) {
 143         char buf[64];
 144         warning("Ignoring %s - see bugs 4229104 or 646499219",
 145                 os::exception_name(sig, buf, sizeof(buf)));
 146       }
 147       return true;
 148     }
 149   }
 150 
 151   JavaThread* thread = NULL;
 152   VMThread* vmthread = NULL;
 153   if (os::Bsd::signal_handlers_are_installed) {
 154     if (t != NULL ){
 155       if(t->is_Java_thread()) {
 156         thread = (JavaThread*)t;
 157       }
 158       else if(t->is_VM_thread()){
 159         vmthread = (VMThread *)t;
 160       }
 161     }
 162   }
 163 
 164   if (info != NULL && thread != NULL) {
 165     // Handle ALL stack overflow variations here
 166     if (sig == SIGSEGV || sig == SIGBUS) {
 167       address addr = (address) info->si_addr;
 168 
 169       // check if fault address is within thread stack
 170       if (addr < thread->stack_base() &&
 171           addr >= thread->stack_base() - thread->stack_size()) {
 172         // stack overflow
 173         if (thread->in_stack_yellow_zone(addr)) {
 174           thread->disable_stack_yellow_zone();
 175           ShouldNotCallThis();
 176         }
 177         else if (thread->in_stack_red_zone(addr)) {
 178           thread->disable_stack_red_zone();
 179           ShouldNotCallThis();
 180         }
 181       }
 182     }
 183 
 184     /*if (thread->thread_state() == _thread_in_Java) {
 185       ShouldNotCallThis();
 186     }
 187     else*/ if (thread->thread_state() == _thread_in_vm &&
 188                sig == SIGBUS && thread->doing_unsafe_access()) {
 189       ShouldNotCallThis();
 190     }
 191 
 192     // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC
 193     // kicks in and the heap gets shrunk before the field access.
 194     /*if (sig == SIGSEGV || sig == SIGBUS) {
 195       address addr = JNI_FastGetField::find_slowcase_pc(pc);
 196       if (addr != (address)-1) {
 197         stub = addr;
 198       }
 199     }*/
 200 
 201     // Check to see if we caught the safepoint code in the process
 202     // of write protecting the memory serialization page.  It write
 203     // enables the page immediately after protecting it so we can
 204     // just return to retry the write.
 205     if ((sig == SIGSEGV || sig == SIGBUS) &&
 206         os::is_memory_serialize_page(thread, (address) info->si_addr)) {
 207       // Block current thread until permission is restored.
 208       os::block_on_serialize_page_trap();
 209       return true;
 210     }
 211   }
 212 
 213   // signal-chaining
 214   if (os::Bsd::chained_handler(sig, info, ucVoid)) {
 215      return true;
 216   }
 217 
 218   if (!abort_if_unrecognized) {
 219     // caller wants another chance, so give it to him
 220     return false;
 221   }
 222 
 223 #ifndef PRODUCT
 224   if (sig == SIGSEGV) {
 225     fatal("\n#"
 226           "\n#    /--------------------\\"
 227           "\n#    | segmentation fault |"
 228           "\n#    \\---\\ /--------------/"
 229           "\n#        /"
 230           "\n#    [-]        |\\_/|    "
 231           "\n#    (+)=C      |o o|__  "
 232           "\n#    | |        =-*-=__\\ "
 233           "\n#    OOO        c_c_(___)");
 234   }
 235 #endif // !PRODUCT
 236 
 237   const char *fmt =
 238       "caught unhandled signal " INT32_FORMAT " at address " PTR_FORMAT;
 239   char buf[128];
 240 
 241   sprintf(buf, fmt, sig, info->si_addr);
 242   fatal(buf);
 243 }
 244 
 245 void os::Bsd::init_thread_fpu_state(void) {
 246   // Nothing to do
 247 }
 248 
 249 bool os::is_allocatable(size_t bytes) {
 250 #ifdef _LP64
 251   return true;
 252 #else
 253   if (bytes < 2 * G) {
 254     return true;
 255   }
 256 
 257   char* addr = reserve_memory(bytes, NULL);
 258 
 259   if (addr != NULL) {
 260     release_memory(addr, bytes);
 261   }
 262 
 263   return addr != NULL;
 264 #endif // _LP64
 265 }
 266 
 267 ///////////////////////////////////////////////////////////////////////////////
 268 // thread stack
 269 
 270 size_t os::Bsd::min_stack_allowed = 64 * K;
 271 
 272 bool os::Bsd::supports_variable_stack_size() {
 273   return true;
 274 }
 275 
 276 size_t os::Bsd::default_stack_size(os::ThreadType thr_type) {
 277 #ifdef _LP64
 278   size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
 279 #else
 280   size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
 281 #endif // _LP64
 282   return s;
 283 }
 284 
 285 size_t os::Bsd::default_guard_size(os::ThreadType thr_type) {
 286   // Only enable glibc guard pages for non-Java threads
 287   // (Java threads have HotSpot guard pages)
 288   return (thr_type == java_thread ? 0 : page_size());
 289 }
 290 
 291 static void current_stack_region(address *bottom, size_t *size) {
 292   address stack_bottom;
 293   address stack_top;
 294   size_t stack_bytes;
 295 
 296 #ifdef __APPLE__
 297   pthread_t self = pthread_self();
 298   stack_top = (address) pthread_get_stackaddr_np(self);
 299   stack_bytes = pthread_get_stacksize_np(self);
 300   stack_bottom = stack_top - stack_bytes;
 301 #elif defined(__OpenBSD__)
 302   stack_t ss;
 303   int rslt = pthread_stackseg_np(pthread_self(), &ss);
 304 
 305   if (rslt != 0)
 306     fatal(err_msg("pthread_stackseg_np failed with err = " INT32_FORMAT,
 307           rslt));
 308 
 309   stack_top = (address) ss.ss_sp;
 310   stack_bytes  = ss.ss_size;
 311   stack_bottom = stack_top - stack_bytes;
 312 #else
 313   pthread_attr_t attr;
 314 
 315   int rslt = pthread_attr_init(&attr);
 316 
 317   // JVM needs to know exact stack location, abort if it fails
 318   if (rslt != 0)
 319     fatal(err_msg("pthread_attr_init failed with err = " INT32_FORMAT, rslt));
 320 
 321   rslt = pthread_attr_get_np(pthread_self(), &attr);
 322 
 323   if (rslt != 0)
 324     fatal(err_msg("pthread_attr_get_np failed with err = " INT32_FORMAT,
 325           rslt));
 326 
 327   if (pthread_attr_getstackaddr(&attr, (void **) &stack_bottom) != 0 ||
 328       pthread_attr_getstacksize(&attr, &stack_bytes) != 0) {
 329     fatal("Can not locate current stack attributes!");
 330   }
 331 
 332   pthread_attr_destroy(&attr);
 333 
 334   stack_top = stack_bottom + stack_bytes;
 335 #endif
 336 
 337   assert(os::current_stack_pointer() >= stack_bottom, "should do");
 338   assert(os::current_stack_pointer() < stack_top, "should do");
 339 
 340   *bottom = stack_bottom;
 341   *size = stack_top - stack_bottom;
 342 }
 343 
 344 address os::current_stack_base() {
 345   address bottom;
 346   size_t size;
 347   current_stack_region(&bottom, &size);
 348   return bottom + size;
 349 }
 350 
 351 size_t os::current_stack_size() {
 352   // stack size includes normal stack and HotSpot guard pages
 353   address bottom;
 354   size_t size;
 355   current_stack_region(&bottom, &size);
 356   return size;
 357 }
 358 
 359 /////////////////////////////////////////////////////////////////////////////
 360 // helper functions for fatal error handler
 361 
 362 void os::print_context(outputStream* st, void* context) {
 363   ShouldNotCallThis();
 364 }
 365 
 366 void os::print_register_info(outputStream *st, void *context) {
 367   ShouldNotCallThis();
 368 }
 369 
 370 /////////////////////////////////////////////////////////////////////////////
 371 // Stubs for things that would be in bsd_zero.s if it existed.
 372 // You probably want to disassemble these monkeys to check they're ok.
 373 
 374 extern "C" {
 375   int SpinPause() {
 376   }
 377 
 378   int SafeFetch32(int *adr, int errValue) {
 379     int value = errValue;
 380     value = *adr;
 381     return value;
 382   }
 383   intptr_t SafeFetchN(intptr_t *adr, intptr_t errValue) {
 384     intptr_t value = errValue;
 385     value = *adr;
 386     return value;
 387   }
 388 
 389   void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
 390     if (from > to) {
 391       jshort *end = from + count;
 392       while (from < end)
 393         *(to++) = *(from++);
 394     }
 395     else if (from < to) {
 396       jshort *end = from;
 397       from += count - 1;
 398       to   += count - 1;
 399       while (from >= end)
 400         *(to--) = *(from--);
 401     }
 402   }
 403   void _Copy_conjoint_jints_atomic(jint* from, jint* to, size_t count) {
 404     if (from > to) {
 405       jint *end = from + count;
 406       while (from < end)
 407         *(to++) = *(from++);
 408     }
 409     else if (from < to) {
 410       jint *end = from;
 411       from += count - 1;
 412       to   += count - 1;
 413       while (from >= end)
 414         *(to--) = *(from--);
 415     }
 416   }
 417   void _Copy_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
 418     if (from > to) {
 419       jlong *end = from + count;
 420       while (from < end)
 421         os::atomic_copy64(from++, to++);
 422     }
 423     else if (from < to) {
 424       jlong *end = from;
 425       from += count - 1;
 426       to   += count - 1;
 427       while (from >= end)
 428         os::atomic_copy64(from--, to--);
 429     }
 430   }
 431 
 432   void _Copy_arrayof_conjoint_bytes(HeapWord* from,
 433                                     HeapWord* to,
 434                                     size_t    count) {
 435     memmove(to, from, count);
 436   }
 437   void _Copy_arrayof_conjoint_jshorts(HeapWord* from,
 438                                       HeapWord* to,
 439                                       size_t    count) {
 440     memmove(to, from, count * 2);
 441   }
 442   void _Copy_arrayof_conjoint_jints(HeapWord* from,
 443                                     HeapWord* to,
 444                                     size_t    count) {
 445     memmove(to, from, count * 4);
 446   }
 447   void _Copy_arrayof_conjoint_jlongs(HeapWord* from,
 448                                      HeapWord* to,
 449                                      size_t    count) {
 450     memmove(to, from, count * 8);
 451   }
 452 };
 453 
 454 /////////////////////////////////////////////////////////////////////////////
 455 // Implementations of atomic operations not supported by processors.
 456 //  -- http://gcc.gnu.org/onlinedocs/gcc-4.2.1/gcc/Atomic-Builtins.html
 457 
 458 #ifndef _LP64
 459 extern "C" {
 460   long long unsigned int __sync_val_compare_and_swap_8(
 461     volatile void *ptr,
 462     long long unsigned int oldval,
 463     long long unsigned int newval) {
 464     ShouldNotCallThis();
 465   }
 466 };
 467 #endif // !_LP64
 468 
 469 #ifndef PRODUCT
 470 void os::verify_stack_alignment() {
 471 }
 472 #endif