1 /*
   2  * Copyright (c) 2003, 2019, 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 "jvm.h"
  33 #include "assembler_zero.inline.hpp"
  34 #include "classfile/classLoader.hpp"
  35 #include "classfile/systemDictionary.hpp"
  36 #include "classfile/vmSymbols.hpp"
  37 #include "code/icBuffer.hpp"
  38 #include "code/vtableStubs.hpp"
  39 #include "interpreter/interpreter.hpp"
  40 #include "memory/allocation.inline.hpp"
  41 #include "nativeInst_zero.hpp"
  42 #include "os_share_bsd.hpp"
  43 #include "prims/jniFastGetField.hpp"
  44 #include "prims/jvm_misc.hpp"
  45 #include "runtime/arguments.hpp"
  46 #include "runtime/extendedPC.hpp"
  47 #include "runtime/frame.inline.hpp"
  48 #include "runtime/interfaceSupport.inline.hpp"
  49 #include "runtime/java.hpp"
  50 #include "runtime/javaCalls.hpp"
  51 #include "runtime/mutexLocker.hpp"
  52 #include "runtime/osThread.hpp"
  53 #include "runtime/sharedRuntime.hpp"
  54 #include "runtime/stubRoutines.hpp"
  55 #include "runtime/thread.inline.hpp"
  56 #include "runtime/timer.hpp"
  57 #include "utilities/events.hpp"
  58 #include "utilities/vmError.hpp"
  59 
  60 // See stubGenerator_zero.cpp
  61 #include <setjmp.h>
  62 extern sigjmp_buf* get_jmp_buf_for_continuation();
  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   return frame();
  72 }
  73 
  74 frame os::current_frame() {
  75   // The only thing that calls this is the stack printing code in
  76   // VMError::report:
  77   //   - Step 110 (printing stack bounds) uses the sp in the frame
  78   //     to determine the amount of free space on the stack.  We
  79   //     set the sp to a close approximation of the real value in
  80   //     order to allow this step to complete.
  81   //   - Step 120 (printing native stack) tries to walk the stack.
  82   //     The frame we create has a NULL pc, which is ignored as an
  83   //     invalid frame.
  84   frame dummy = frame();
  85   dummy.set_sp((intptr_t *) current_stack_pointer());
  86   return dummy;
  87 }
  88 
  89 char* os::non_memory_address_word() {
  90   // Must never look like an address returned by reserve_memory,
  91   // even in its subfields (as defined by the CPU immediate fields,
  92   // if the CPU splits constants across multiple instructions).
  93 #ifdef SPARC
  94   // On SPARC, 0 != %hi(any real address), because there is no
  95   // allocation in the first 1Kb of the virtual address space.
  96   return (char *) 0;
  97 #else
  98   // This is the value for x86; works pretty well for PPC too.
  99   return (char *) -1;
 100 #endif // SPARC
 101 }
 102 
 103 address os::Bsd::ucontext_get_pc(const ucontext_t* uc) {
 104   ShouldNotCallThis();
 105   return NULL;
 106 }
 107 
 108 void os::Bsd::ucontext_set_pc(ucontext_t * uc, address pc) {
 109   ShouldNotCallThis();
 110 }
 111 
 112 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
 113                                         intptr_t** ret_sp,
 114                                         intptr_t** ret_fp) {
 115   ShouldNotCallThis();
 116   return ExtendedPC();
 117 }
 118 
 119 frame os::fetch_frame_from_context(const void* ucVoid) {
 120   ShouldNotCallThis();
 121   return frame();
 122 }
 123 
 124 extern "C" JNIEXPORT int
 125 JVM_handle_bsd_signal(int sig,
 126                         siginfo_t* info,
 127                         void* ucVoid,
 128                         int abort_if_unrecognized) {
 129   ucontext_t* uc = (ucontext_t*) ucVoid;
 130 
 131   Thread* t = Thread::current_or_null_safe();
 132 
 133   SignalHandlerMark shm(t);
 134 
 135   // handle SafeFetch faults
 136   if (sig == SIGSEGV || sig == SIGBUS) {
 137     sigjmp_buf* const pjb = get_jmp_buf_for_continuation();
 138     if (pjb) {
 139       siglongjmp(*pjb, 1);
 140     }
 141   }
 142 
 143   // Note: it's not uncommon that JNI code uses signal/sigset to
 144   // install then restore certain signal handler (e.g. to temporarily
 145   // block SIGPIPE, or have a SIGILL handler when detecting CPU
 146   // type). When that happens, JVM_handle_bsd_signal() might be
 147   // invoked with junk info/ucVoid. To avoid unnecessary crash when
 148   // libjsig is not preloaded, try handle signals that do not require
 149   // siginfo/ucontext first.
 150 
 151   if (sig == SIGPIPE || sig == SIGXFSZ) {
 152     // allow chained handler to go first
 153     if (os::Bsd::chained_handler(sig, info, ucVoid)) {
 154       return true;
 155     } else {
 156       // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
 157       return true;
 158     }
 159   }
 160 
 161   JavaThread* thread = NULL;
 162   VMThread* vmthread = NULL;
 163   if (os::Bsd::signal_handlers_are_installed) {
 164     if (t != NULL ){
 165       if(t->is_Java_thread()) {
 166         thread = (JavaThread*)t;
 167       }
 168       else if(t->is_VM_thread()){
 169         vmthread = (VMThread *)t;
 170       }
 171     }
 172   }
 173 
 174   if (info != NULL && thread != NULL) {
 175     // Handle ALL stack overflow variations here
 176     if (sig == SIGSEGV || sig == SIGBUS) {
 177       address addr = (address) info->si_addr;
 178 
 179       // check if fault address is within thread stack
 180       if (thread->on_local_stack(addr)) {
 181         // stack overflow
 182         if (thread->in_stack_yellow_reserved_zone(addr)) {
 183           thread->disable_stack_yellow_reserved_zone();
 184           ShouldNotCallThis();
 185         }
 186         else if (thread->in_stack_red_zone(addr)) {
 187           thread->disable_stack_red_zone();
 188           ShouldNotCallThis();
 189         }
 190       }
 191     }
 192 
 193     /*if (thread->thread_state() == _thread_in_Java) {
 194       ShouldNotCallThis();
 195     }
 196     else*/ if ((thread->thread_state() == _thread_in_vm ||
 197                thread->thread_state() == _thread_in_native) &&
 198                sig == SIGBUS && thread->doing_unsafe_access()) {
 199       ShouldNotCallThis();
 200     }
 201 
 202     // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC
 203     // kicks in and the heap gets shrunk before the field access.
 204     /*if (sig == SIGSEGV || sig == SIGBUS) {
 205       address addr = JNI_FastGetField::find_slowcase_pc(pc);
 206       if (addr != (address)-1) {
 207         stub = addr;
 208       }
 209     }*/
 210   }
 211 
 212   // signal-chaining
 213   if (os::Bsd::chained_handler(sig, info, ucVoid)) {
 214      return true;
 215   }
 216 
 217   if (!abort_if_unrecognized) {
 218     // caller wants another chance, so give it to him
 219     return false;
 220   }
 221 
 222 #ifndef PRODUCT
 223   if (sig == SIGSEGV) {
 224     fatal("\n#"
 225           "\n#    /--------------------\\"
 226           "\n#    | segmentation fault |"
 227           "\n#    \\---\\ /--------------/"
 228           "\n#        /"
 229           "\n#    [-]        |\\_/|    "
 230           "\n#    (+)=C      |o o|__  "
 231           "\n#    | |        =-*-=__\\ "
 232           "\n#    OOO        c_c_(___)");
 233   }
 234 #endif // !PRODUCT
 235 
 236   const char *fmt =
 237       "caught unhandled signal " INT32_FORMAT " at address " PTR_FORMAT;
 238   char buf[128];
 239 
 240   sprintf(buf, fmt, sig, info->si_addr);
 241   fatal(buf);
 242   return false;
 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::Posix::_compiler_thread_min_stack_allowed = 64 * K;
 271 size_t os::Posix::_java_thread_min_stack_allowed = 64 * K;
 272 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K;
 273 
 274 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
 275 #ifdef _LP64
 276   size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
 277 #else
 278   size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
 279 #endif // _LP64
 280   return s;
 281 }
 282 
 283 static void current_stack_region(address *bottom, size_t *size) {
 284   address stack_bottom;
 285   address stack_top;
 286   size_t stack_bytes;
 287 
 288 #ifdef __APPLE__
 289   pthread_t self = pthread_self();
 290   stack_top = (address) pthread_get_stackaddr_np(self);
 291   stack_bytes = pthread_get_stacksize_np(self);
 292   stack_bottom = stack_top - stack_bytes;
 293 #elif defined(__OpenBSD__)
 294   stack_t ss;
 295   int rslt = pthread_stackseg_np(pthread_self(), &ss);
 296 
 297   if (rslt != 0)
 298     fatal("pthread_stackseg_np failed with error = " INT32_FORMAT, rslt);
 299 
 300   stack_top = (address) ss.ss_sp;
 301   stack_bytes  = ss.ss_size;
 302   stack_bottom = stack_top - stack_bytes;
 303 #else
 304   pthread_attr_t attr;
 305 
 306   int rslt = pthread_attr_init(&attr);
 307 
 308   // JVM needs to know exact stack location, abort if it fails
 309   if (rslt != 0)
 310     fatal("pthread_attr_init failed with error = " INT32_FORMAT, rslt);
 311 
 312   rslt = pthread_attr_get_np(pthread_self(), &attr);
 313 
 314   if (rslt != 0)
 315     fatal("pthread_attr_get_np failed with error = " INT32_FORMAT, rslt);
 316 
 317   if (pthread_attr_getstackaddr(&attr, (void **) &stack_bottom) != 0 ||
 318       pthread_attr_getstacksize(&attr, &stack_bytes) != 0) {
 319     fatal("Can not locate current stack attributes!");
 320   }
 321 
 322   pthread_attr_destroy(&attr);
 323 
 324   stack_top = stack_bottom + stack_bytes;
 325 #endif
 326 
 327   assert(os::current_stack_pointer() >= stack_bottom, "should do");
 328   assert(os::current_stack_pointer() < stack_top, "should do");
 329 
 330   *bottom = stack_bottom;
 331   *size = stack_top - stack_bottom;
 332 }
 333 
 334 address os::current_stack_base() {
 335   address bottom;
 336   size_t size;
 337   current_stack_region(&bottom, &size);
 338   return bottom + size;
 339 }
 340 
 341 size_t os::current_stack_size() {
 342   // stack size includes normal stack and HotSpot guard pages
 343   address bottom;
 344   size_t size;
 345   current_stack_region(&bottom, &size);
 346   return size;
 347 }
 348 
 349 /////////////////////////////////////////////////////////////////////////////
 350 // helper functions for fatal error handler
 351 
 352 void os::print_context(outputStream* st, const void* context) {
 353   ShouldNotCallThis();
 354 }
 355 
 356 void os::print_register_info(outputStream *st, const void *context) {
 357   ShouldNotCallThis();
 358 }
 359 
 360 /////////////////////////////////////////////////////////////////////////////
 361 // Stubs for things that would be in bsd_zero.s if it existed.
 362 // You probably want to disassemble these monkeys to check they're ok.
 363 
 364 extern "C" {
 365   int SpinPause() {
 366     return 1;
 367   }
 368 
 369   void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
 370     if (from > to) {
 371       jshort *end = from + count;
 372       while (from < end)
 373         *(to++) = *(from++);
 374     }
 375     else if (from < to) {
 376       jshort *end = from;
 377       from += count - 1;
 378       to   += count - 1;
 379       while (from >= end)
 380         *(to--) = *(from--);
 381     }
 382   }
 383   void _Copy_conjoint_jints_atomic(jint* from, jint* to, size_t count) {
 384     if (from > to) {
 385       jint *end = from + count;
 386       while (from < end)
 387         *(to++) = *(from++);
 388     }
 389     else if (from < to) {
 390       jint *end = from;
 391       from += count - 1;
 392       to   += count - 1;
 393       while (from >= end)
 394         *(to--) = *(from--);
 395     }
 396   }
 397   void _Copy_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
 398     if (from > to) {
 399       jlong *end = from + count;
 400       while (from < end)
 401         os::atomic_copy64(from++, to++);
 402     }
 403     else if (from < to) {
 404       jlong *end = from;
 405       from += count - 1;
 406       to   += count - 1;
 407       while (from >= end)
 408         os::atomic_copy64(from--, to--);
 409     }
 410   }
 411 
 412   void _Copy_arrayof_conjoint_bytes(HeapWord* from,
 413                                     HeapWord* to,
 414                                     size_t    count) {
 415     memmove(to, from, count);
 416   }
 417   void _Copy_arrayof_conjoint_jshorts(HeapWord* from,
 418                                       HeapWord* to,
 419                                       size_t    count) {
 420     memmove(to, from, count * 2);
 421   }
 422   void _Copy_arrayof_conjoint_jints(HeapWord* from,
 423                                     HeapWord* to,
 424                                     size_t    count) {
 425     memmove(to, from, count * 4);
 426   }
 427   void _Copy_arrayof_conjoint_jlongs(HeapWord* from,
 428                                      HeapWord* to,
 429                                      size_t    count) {
 430     memmove(to, from, count * 8);
 431   }
 432 };
 433 
 434 /////////////////////////////////////////////////////////////////////////////
 435 // Implementations of atomic operations not supported by processors.
 436 //  -- http://gcc.gnu.org/onlinedocs/gcc-4.2.1/gcc/Atomic-Builtins.html
 437 
 438 #ifndef _LP64
 439 extern "C" {
 440   long long unsigned int __sync_val_compare_and_swap_8(
 441     volatile void *ptr,
 442     long long unsigned int oldval,
 443     long long unsigned int newval) {
 444     ShouldNotCallThis();
 445   }
 446 };
 447 #endif // !_LP64
 448 
 449 #ifndef PRODUCT
 450 void os::verify_stack_alignment() {
 451 }
 452 #endif
 453 
 454 int os::extra_bang_size_in_bytes() {
 455   // Zero does not require an additional stack bang.
 456   return 0;
 457 }