1 /*
   2  * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/javaClasses.hpp"
  27 #include "classfile/javaClasses.inline.hpp"
  28 #include "classfile/vmSymbols.hpp"
  29 #include "logging/log.hpp"
  30 #include "logging/logStream.hpp"
  31 #include "memory/oopFactory.hpp"
  32 #include "oops/oop.inline.hpp"
  33 #include "oops/objArrayOop.inline.hpp"
  34 #include "prims/stackwalk.hpp"
  35 #include "runtime/globals.hpp"
  36 #include "runtime/handles.inline.hpp"
  37 #include "runtime/javaCalls.hpp"
  38 #include "runtime/vframe.hpp"
  39 #include "utilities/globalDefinitions.hpp"
  40 
  41 // setup and cleanup actions
  42 void BaseFrameStream::setup_magic_on_entry(objArrayHandle frames_array) {
  43   frames_array->obj_at_put(magic_pos, _thread->threadObj());
  44   _anchor = address_value();
  45   assert(check_magic(frames_array), "invalid magic");
  46 }
  47 
  48 bool BaseFrameStream::check_magic(objArrayHandle frames_array) {
  49   oop   m1 = frames_array->obj_at(magic_pos);
  50   jlong m2 = _anchor;
  51   if (m1 == _thread->threadObj() && m2 == address_value())  return true;
  52   return false;
  53 }
  54 
  55 bool BaseFrameStream::cleanup_magic_on_exit(objArrayHandle frames_array) {
  56   bool ok = check_magic(frames_array);
  57   frames_array->obj_at_put(magic_pos, NULL);
  58   _anchor = 0L;
  59   return ok;
  60 }
  61 
  62 JavaFrameStream::JavaFrameStream(JavaThread* thread, int mode)
  63   : BaseFrameStream(thread), _vfst(thread) {
  64   _need_method_info = StackWalk::need_method_info(mode);
  65 }
  66 
  67 // Returns the BaseFrameStream for the current stack being traversed.
  68 //
  69 // Parameters:
  70 //  thread         Current Java thread.
  71 //  magic          Magic value used for each stack walking
  72 //  frames_array   User-supplied buffers.  The 0th element is reserved
  73 //                 for this BaseFrameStream to use
  74 //
  75 BaseFrameStream* BaseFrameStream::from_current(JavaThread* thread, jlong magic,
  76                                                objArrayHandle frames_array)
  77 {
  78   assert(thread != NULL && thread->is_Java_thread(), "");
  79   oop m1 = frames_array->obj_at(magic_pos);
  80   if (m1 != thread->threadObj())      return NULL;
  81   if (magic == 0L)                    return NULL;
  82   BaseFrameStream* stream = (BaseFrameStream*) (intptr_t) magic;
  83   if (!stream->is_valid_in(thread, frames_array))   return NULL;
  84   return stream;
  85 }
  86 
  87 // Unpacks one or more frames into user-supplied buffers.
  88 // Updates the end index, and returns the number of unpacked frames.
  89 // Always start with the existing vfst.method and bci.
  90 // Do not call vfst.next to advance over the last returned value.
  91 // In other words, do not leave any stale data in the vfst.
  92 //
  93 // Parameters:
  94 //   mode             Restrict which frames to be decoded.
  95 //   BaseFrameStream  stream of frames
  96 //   max_nframes      Maximum number of frames to be filled.
  97 //   start_index      Start index to the user-supplied buffers.
  98 //   frames_array     Buffer to store Class or StackFrame in, starting at start_index.
  99 //                    frames array is a Class<?>[] array when only getting caller
 100 //                    reference, and a StackFrameInfo[] array (or derivative)
 101 //                    otherwise. It should never be null.
 102 //   end_index        End index to the user-supplied buffers with unpacked frames.
 103 //
 104 // Returns the number of frames whose information was transferred into the buffers.
 105 //
 106 int StackWalk::fill_in_frames(jlong mode, BaseFrameStream& stream,
 107                               int max_nframes, int start_index,
 108                               objArrayHandle  frames_array,
 109                               int& end_index, TRAPS) {
 110   log_debug(stackwalk)("fill_in_frames limit=%d start=%d frames length=%d",
 111                        max_nframes, start_index, frames_array->length());
 112   assert(max_nframes > 0, "invalid max_nframes");
 113   assert(start_index + max_nframes <= frames_array->length(), "oob");
 114 
 115   int frames_decoded = 0;
 116   for (; !stream.at_end(); stream.next()) {
 117     Method* method = stream.method();
 118 
 119     if (method == NULL) continue;
 120 
 121     // skip hidden frames for default StackWalker option (i.e. SHOW_HIDDEN_FRAMES
 122     // not set) and when StackWalker::getCallerClass is called
 123     if (!ShowHiddenFrames && (skip_hidden_frames(mode) || get_caller_class(mode))) {
 124       if (method->is_hidden()) {
 125         LogTarget(Debug, stackwalk) lt;
 126         if (lt.is_enabled()) {
 127           ResourceMark rm(THREAD);
 128           LogStream ls(lt);
 129           ls.print("  hidden method: ");
 130           method->print_short_name(&ls);
 131           ls.cr();
 132         }
 133         continue;
 134       }
 135     }
 136 
 137     int index = end_index++;
 138     LogTarget(Debug, stackwalk) lt;
 139     if (lt.is_enabled()) {
 140       ResourceMark rm(THREAD);
 141       LogStream ls(lt);
 142       ls.print("  %d: frame method: ", index);
 143       method->print_short_name(&ls);
 144       ls.print_cr(" bci=%d", stream.bci());
 145     }
 146 
 147     if (!need_method_info(mode) && get_caller_class(mode) &&
 148           index == start_index && method->caller_sensitive()) {
 149       ResourceMark rm(THREAD);
 150       THROW_MSG_0(vmSymbols::java_lang_UnsupportedOperationException(),
 151         err_msg("StackWalker::getCallerClass called from @CallerSensitive %s method",
 152                 method->name_and_sig_as_C_string()));
 153     }
 154     // fill in StackFrameInfo and initialize MemberName
 155     stream.fill_frame(index, frames_array, method, CHECK_0);
 156     if (++frames_decoded >= max_nframes)  break;
 157   }
 158   return frames_decoded;
 159 }
 160 
 161 // Fill in the LiveStackFrameInfo at the given index in frames_array
 162 void LiveFrameStream::fill_frame(int index, objArrayHandle  frames_array,
 163                                  const methodHandle& method, TRAPS) {
 164   Handle stackFrame(THREAD, frames_array->obj_at(index));
 165   fill_live_stackframe(stackFrame, method, CHECK);
 166 }
 167 
 168 // Fill in the StackFrameInfo at the given index in frames_array
 169 void JavaFrameStream::fill_frame(int index, objArrayHandle  frames_array,
 170                                  const methodHandle& method, TRAPS) {
 171   if (_need_method_info) {
 172     Handle stackFrame(THREAD, frames_array->obj_at(index));
 173     fill_stackframe(stackFrame, method, CHECK);
 174   } else {
 175     frames_array->obj_at_put(index, method->method_holder()->java_mirror());
 176   }
 177 }
 178 
 179 // Create and return a LiveStackFrame.PrimitiveSlot (if needed) for the
 180 // StackValue at the given index. 'type' is expected to be T_INT, T_LONG,
 181 // T_OBJECT, or T_CONFLICT.
 182 oop LiveFrameStream::create_primitive_slot_instance(StackValueCollection* values,
 183                                                     int i, BasicType type, TRAPS) {
 184   Klass* k = SystemDictionary::resolve_or_null(vmSymbols::java_lang_LiveStackFrameInfo(), CHECK_NULL);
 185   InstanceKlass* ik = InstanceKlass::cast(k);
 186 
 187   JavaValue result(T_OBJECT);
 188   JavaCallArguments args;
 189   Symbol* signature = NULL;
 190 
 191   // ## TODO: type is only available in LocalVariable table, if present.
 192   // ## StackValue type is T_INT or T_OBJECT (or converted to T_LONG on 64-bit)
 193   switch (type) {
 194     case T_INT:
 195       args.push_int(values->int_at(i));
 196       signature = vmSymbols::asPrimitive_int_signature();
 197       break;
 198 
 199     case T_LONG:
 200       args.push_long(values->long_at(i));
 201       signature = vmSymbols::asPrimitive_long_signature();
 202       break;
 203 
 204     case T_FLOAT:
 205     case T_DOUBLE:
 206     case T_BYTE:
 207     case T_SHORT:
 208     case T_CHAR:
 209     case T_BOOLEAN:
 210       THROW_MSG_(vmSymbols::java_lang_InternalError(), "Unexpected StackValue type", NULL);
 211 
 212     case T_OBJECT:
 213       return values->obj_at(i)();
 214 
 215     case T_CONFLICT:
 216       // put a non-null slot
 217       #ifdef _LP64
 218         args.push_long(0);
 219         signature = vmSymbols::asPrimitive_long_signature();
 220       #else
 221         args.push_int(0);
 222         signature = vmSymbols::asPrimitive_int_signature();
 223       #endif
 224 
 225       break;
 226 
 227     default: ShouldNotReachHere();
 228   }
 229   JavaCalls::call_static(&result,
 230                          ik,
 231                          vmSymbols::asPrimitive_name(),
 232                          signature,
 233                          &args,
 234                          CHECK_NULL);
 235   return (instanceOop) result.get_jobject();
 236 }
 237 
 238 objArrayHandle LiveFrameStream::values_to_object_array(StackValueCollection* values, TRAPS) {
 239   objArrayHandle empty;
 240   int length = values->size();
 241   objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
 242                                                    length, CHECK_(empty));
 243   objArrayHandle array_h(THREAD, array_oop);
 244   for (int i = 0; i < values->size(); i++) {
 245     StackValue* st = values->at(i);
 246     BasicType type = st->type();
 247     int index = i;
 248 #ifdef _LP64
 249     if (type != T_OBJECT && type != T_CONFLICT) {
 250         intptr_t ret = st->get_int(); // read full 64-bit slot
 251         type = T_LONG;                // treat as long
 252         index--;                      // undo +1 in StackValueCollection::long_at
 253     }
 254 #endif
 255     oop obj = create_primitive_slot_instance(values, index, type, CHECK_(empty));
 256     if (obj != NULL) {
 257       array_h->obj_at_put(i, obj);
 258     }
 259   }
 260   return array_h;
 261 }
 262 
 263 objArrayHandle LiveFrameStream::monitors_to_object_array(GrowableArray<MonitorInfo*>* monitors, TRAPS) {
 264   int length = monitors->length();
 265   objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
 266                                                    length, CHECK_(objArrayHandle()));
 267   objArrayHandle array_h(THREAD, array_oop);
 268   for (int i = 0; i < length; i++) {
 269     MonitorInfo* monitor = monitors->at(i);
 270     array_h->obj_at_put(i, monitor->owner());
 271   }
 272   return array_h;
 273 }
 274 
 275 // Fill StackFrameInfo with declaringClass and bci and initialize memberName
 276 void BaseFrameStream::fill_stackframe(Handle stackFrame, const methodHandle& method, TRAPS) {
 277   java_lang_StackFrameInfo::set_declaringClass(stackFrame(), method->method_holder()->java_mirror());
 278   java_lang_StackFrameInfo::set_method_and_bci(stackFrame, method, bci(), THREAD);
 279 }
 280 
 281 // Fill LiveStackFrameInfo with locals, monitors, and expressions
 282 void LiveFrameStream::fill_live_stackframe(Handle stackFrame,
 283                                            const methodHandle& method, TRAPS) {
 284   fill_stackframe(stackFrame, method, CHECK);
 285   if (_jvf != NULL) {
 286     StackValueCollection* locals = _jvf->locals();
 287     StackValueCollection* expressions = _jvf->expressions();
 288     GrowableArray<MonitorInfo*>* monitors = _jvf->monitors();
 289 
 290     int mode = 0;
 291     if (_jvf->is_interpreted_frame()) {
 292       mode = MODE_INTERPRETED;
 293     } else if (_jvf->is_compiled_frame()) {
 294       mode = MODE_COMPILED;
 295     }
 296 
 297     if (!locals->is_empty()) {
 298       objArrayHandle locals_h = values_to_object_array(locals, CHECK);
 299       java_lang_LiveStackFrameInfo::set_locals(stackFrame(), locals_h());
 300     }
 301     if (!expressions->is_empty()) {
 302       objArrayHandle expressions_h = values_to_object_array(expressions, CHECK);
 303       java_lang_LiveStackFrameInfo::set_operands(stackFrame(), expressions_h());
 304     }
 305     if (monitors->length() > 0) {
 306       objArrayHandle monitors_h = monitors_to_object_array(monitors, CHECK);
 307       java_lang_LiveStackFrameInfo::set_monitors(stackFrame(), monitors_h());
 308     }
 309     java_lang_LiveStackFrameInfo::set_mode(stackFrame(), mode);
 310   }
 311 }
 312 
 313 // Begins stack walking.
 314 //
 315 // Parameters:
 316 //   stackStream    StackStream object
 317 //   mode           Stack walking mode.
 318 //   skip_frames    Number of frames to be skipped.
 319 //   frame_count    Number of frames to be traversed.
 320 //   start_index    Start index to the user-supplied buffers.
 321 //   frames_array   Buffer to store StackFrame in, starting at start_index.
 322 //                  frames array is a Class<?>[] array when only getting caller
 323 //                  reference, and a StackFrameInfo[] array (or derivative)
 324 //                  otherwise. It should never be null.
 325 //
 326 // Returns Object returned from AbstractStackWalker::doStackWalk call.
 327 //
 328 oop StackWalk::walk(Handle stackStream, jlong mode,
 329                     int skip_frames, int frame_count, int start_index,
 330                     objArrayHandle frames_array,
 331                     TRAPS) {
 332   ResourceMark rm(THREAD);
 333   JavaThread* jt = (JavaThread*)THREAD;
 334   log_debug(stackwalk)("Start walking: mode " JLONG_FORMAT " skip %d frames batch size %d",
 335                        mode, skip_frames, frame_count);
 336 
 337   if (frames_array.is_null()) {
 338     THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", NULL);
 339   }
 340 
 341   // Setup traversal onto my stack.
 342   if (live_frame_info(mode)) {
 343     assert (use_frames_array(mode), "Bad mode for get live frame");
 344     RegisterMap regMap(jt, true);
 345     LiveFrameStream stream(jt, &regMap);
 346     return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
 347                            start_index, frames_array, THREAD);
 348   } else {
 349     JavaFrameStream stream(jt, mode);
 350     return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
 351                            start_index, frames_array, THREAD);
 352   }
 353 }
 354 
 355 oop StackWalk::fetchFirstBatch(BaseFrameStream& stream, Handle stackStream,
 356                                jlong mode, int skip_frames, int frame_count,
 357                                int start_index, objArrayHandle frames_array, TRAPS) {
 358   methodHandle m_doStackWalk(THREAD, Universe::do_stack_walk_method());
 359 
 360   {
 361     Klass* stackWalker_klass = SystemDictionary::StackWalker_klass();
 362     Klass* abstractStackWalker_klass = SystemDictionary::AbstractStackWalker_klass();
 363     while (!stream.at_end()) {
 364       InstanceKlass* ik = stream.method()->method_holder();
 365       if (ik != stackWalker_klass &&
 366             ik != abstractStackWalker_klass && ik->super() != abstractStackWalker_klass)  {
 367         break;
 368       }
 369 
 370       LogTarget(Debug, stackwalk) lt;
 371       if (lt.is_enabled()) {
 372         ResourceMark rm(THREAD);
 373         LogStream ls(lt);      
 374         ls.print("  skip ");
 375         stream.method()->print_short_name(&ls);
 376         ls.cr();
 377       }
 378       stream.next();
 379     }
 380 
 381     // stack frame has been traversed individually and resume stack walk
 382     // from the stack frame at depth == skip_frames.
 383     for (int n=0; n < skip_frames && !stream.at_end(); stream.next(), n++) {
 384       LogTarget(Debug, stackwalk) lt;
 385       if (lt.is_enabled()) {
 386         ResourceMark rm(THREAD);
 387         LogStream ls(lt);
 388         ls.print("  skip ");
 389         stream.method()->print_short_name(&ls);
 390         ls.cr();
 391       }
 392     }
 393   }
 394 
 395   int end_index = start_index;
 396   int numFrames = 0;
 397   if (!stream.at_end()) {
 398     numFrames = fill_in_frames(mode, stream, frame_count, start_index,
 399                                frames_array, end_index, CHECK_NULL);
 400     if (numFrames < 1) {
 401       THROW_MSG_(vmSymbols::java_lang_InternalError(), "stack walk: decode failed", NULL);
 402     }
 403   }
 404 
 405   // JVM_CallStackWalk walks the stack and fills in stack frames, then calls to
 406   // Java method java.lang.StackStreamFactory.AbstractStackWalker::doStackWalk
 407   // which calls the implementation to consume the stack frames.
 408   // When JVM_CallStackWalk returns, it invalidates the stack stream.
 409   JavaValue result(T_OBJECT);
 410   JavaCallArguments args(stackStream);
 411   args.push_long(stream.address_value());
 412   args.push_int(skip_frames);
 413   args.push_int(frame_count);
 414   args.push_int(start_index);
 415   args.push_int(end_index);
 416 
 417   // Link the thread and vframe stream into the callee-visible object
 418   stream.setup_magic_on_entry(frames_array);
 419 
 420   JavaCalls::call(&result, m_doStackWalk, &args, THREAD);
 421 
 422   // Do this before anything else happens, to disable any lingering stream objects
 423   bool ok = stream.cleanup_magic_on_exit(frames_array);
 424 
 425   // Throw pending exception if we must
 426   (void) (CHECK_NULL);
 427 
 428   if (!ok) {
 429     THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers on exit", NULL);
 430   }
 431 
 432   // Return normally
 433   return (oop)result.get_jobject();
 434 }
 435 
 436 // Walk the next batch of stack frames
 437 //
 438 // Parameters:
 439 //   stackStream    StackStream object
 440 //   mode           Stack walking mode.
 441 //   magic          Must be valid value to continue the stack walk
 442 //   frame_count    Number of frames to be decoded.
 443 //   start_index    Start index to the user-supplied buffers.
 444 //   frames_array   Buffer to store StackFrame in, starting at start_index.
 445 //
 446 // Returns the end index of frame filled in the buffer.
 447 //
 448 jint StackWalk::fetchNextBatch(Handle stackStream, jlong mode, jlong magic,
 449                                int frame_count, int start_index,
 450                                objArrayHandle frames_array,
 451                                TRAPS)
 452 {
 453   JavaThread* jt = (JavaThread*)THREAD;
 454   BaseFrameStream* existing_stream = BaseFrameStream::from_current(jt, magic, frames_array);
 455   if (existing_stream == NULL) {
 456     THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers", 0L);
 457   }
 458 
 459   if (frames_array.is_null()) {
 460     THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", 0L);
 461   }
 462 
 463   log_debug(stackwalk)("StackWalk::fetchNextBatch frame_count %d existing_stream "
 464                        PTR_FORMAT " start %d frames %d",
 465                        frame_count, p2i(existing_stream), start_index, frames_array->length());
 466   int end_index = start_index;
 467   if (frame_count <= 0) {
 468     return end_index;        // No operation.
 469   }
 470 
 471   int count = frame_count + start_index;
 472   assert (frames_array->length() >= count, "not enough space in buffers");
 473 
 474   BaseFrameStream& stream = (*existing_stream);
 475   if (!stream.at_end()) {
 476     stream.next(); // advance past the last frame decoded in previous batch
 477     if (!stream.at_end()) {
 478       int n = fill_in_frames(mode, stream, frame_count, start_index,
 479                              frames_array, end_index, CHECK_0);
 480       if (n < 1) {
 481         THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: later decode failed", 0L);
 482       }
 483       return end_index;
 484     }
 485   }
 486   return end_index;
 487 }