1 /* 2 * Copyright (c) 2003, 2018, 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 "code/debugInfoRec.hpp" 27 #include "code/pcDesc.hpp" 28 #include "gc/shared/collectedHeap.inline.hpp" 29 #include "gc/shared/space.hpp" 30 #include "memory/universe.hpp" 31 #include "oops/oop.inline.hpp" 32 #include "prims/forte.hpp" 33 #include "runtime/frame.inline.hpp" 34 #include "runtime/javaCalls.hpp" 35 #include "runtime/thread.inline.hpp" 36 #include "runtime/vframe.inline.hpp" 37 #include "runtime/vframeArray.hpp" 38 39 // call frame copied from old .h file and renamed 40 typedef struct { 41 jint lineno; // line number in the source file 42 jmethodID method_id; // method executed in this frame 43 } ASGCT_CallFrame; 44 45 // call trace copied from old .h file and renamed 46 typedef struct { 47 JNIEnv *env_id; // Env where trace was recorded 48 jint num_frames; // number of frames in this trace 49 ASGCT_CallFrame *frames; // frames 50 } ASGCT_CallTrace; 51 52 // These name match the names reported by the forte quality kit 53 enum { 54 ticks_no_Java_frame = 0, 55 ticks_no_class_load = -1, 56 ticks_GC_active = -2, 57 ticks_unknown_not_Java = -3, 58 ticks_not_walkable_not_Java = -4, 59 ticks_unknown_Java = -5, 60 ticks_not_walkable_Java = -6, 61 ticks_unknown_state = -7, 62 ticks_thread_exit = -8, 63 ticks_deopt = -9, 64 ticks_safepoint = -10 65 }; 66 67 #if INCLUDE_JVMTI 68 69 //------------------------------------------------------- 70 71 // Native interfaces for use by Forte tools. 72 73 74 #if !defined(IA64) && !defined(PPC64) 75 76 class vframeStreamForte : public vframeStreamCommon { 77 public: 78 // constructor that starts with sender of frame fr (top_frame) 79 vframeStreamForte(JavaThread *jt, frame fr, bool stop_at_java_call_stub); 80 void forte_next(); 81 }; 82 83 84 static bool is_decipherable_compiled_frame(JavaThread* thread, frame* fr, CompiledMethod* nm); 85 static bool is_decipherable_interpreted_frame(JavaThread* thread, 86 frame* fr, 87 Method** method_p, 88 int* bci_p); 89 90 91 92 93 vframeStreamForte::vframeStreamForte(JavaThread *jt, 94 frame fr, 95 bool stop_at_java_call_stub) : vframeStreamCommon(jt) { 96 97 _stop_at_java_call_stub = stop_at_java_call_stub; 98 _frame = fr; 99 100 // We must always have a valid frame to start filling 101 102 bool filled_in = fill_from_frame(); 103 104 assert(filled_in, "invariant"); 105 106 } 107 108 109 // Solaris SPARC Compiler1 needs an additional check on the grandparent 110 // of the top_frame when the parent of the top_frame is interpreted and 111 // the grandparent is compiled. However, in this method we do not know 112 // the relationship of the current _frame relative to the top_frame so 113 // we implement a more broad sanity check. When the previous callee is 114 // interpreted and the current sender is compiled, we verify that the 115 // current sender is also walkable. If it is not walkable, then we mark 116 // the current vframeStream as at the end. 117 void vframeStreamForte::forte_next() { 118 // handle frames with inlining 119 if (_mode == compiled_mode && 120 vframeStreamCommon::fill_in_compiled_inlined_sender()) { 121 return; 122 } 123 124 // handle general case 125 126 int loop_count = 0; 127 int loop_max = MaxJavaStackTraceDepth * 2; 128 129 130 do { 131 132 loop_count++; 133 134 // By the time we get here we should never see unsafe but better 135 // safe then segv'd 136 137 if ((loop_max != 0 && loop_count > loop_max) || !_frame.safe_for_sender(_thread)) { 138 _mode = at_end_mode; 139 return; 140 } 141 142 _frame = _frame.sender(&_reg_map); 143 144 } while (!fill_from_frame()); 145 } 146 147 // Determine if 'fr' is a decipherable compiled frame. We are already 148 // assured that fr is for a java compiled method. 149 150 static bool is_decipherable_compiled_frame(JavaThread* thread, frame* fr, CompiledMethod* nm) { 151 assert(nm->is_java_method(), "invariant"); 152 153 if (thread->has_last_Java_frame() && thread->last_Java_pc() == fr->pc()) { 154 // We're stopped at a call into the JVM so look for a PcDesc with 155 // the actual pc reported by the frame. 156 PcDesc* pc_desc = nm->pc_desc_at(fr->pc()); 157 158 // Did we find a useful PcDesc? 159 if (pc_desc != NULL && 160 pc_desc->scope_decode_offset() != DebugInformationRecorder::serialized_null) { 161 return true; 162 } 163 } 164 165 // We're at some random pc in the compiled method so search for the PcDesc 166 // whose pc is greater than the current PC. It's done this way 167 // because the extra PcDescs that are recorded for improved debug 168 // info record the end of the region covered by the ScopeDesc 169 // instead of the beginning. 170 PcDesc* pc_desc = nm->pc_desc_near(fr->pc() + 1); 171 172 // Now do we have a useful PcDesc? 173 if (pc_desc == NULL || 174 pc_desc->scope_decode_offset() == DebugInformationRecorder::serialized_null) { 175 // No debug information is available for this PC. 176 // 177 // vframeStreamCommon::fill_from_frame() will decode the frame depending 178 // on the state of the thread. 179 // 180 // Case #1: If the thread is in Java (state == _thread_in_Java), then 181 // the vframeStreamCommon object will be filled as if the frame were a native 182 // compiled frame. Therefore, no debug information is needed. 183 // 184 // Case #2: If the thread is in any other state, then two steps will be performed: 185 // - if asserts are enabled, found_bad_method_frame() will be called and 186 // the assert in found_bad_method_frame() will be triggered; 187 // - if asserts are disabled, the vframeStreamCommon object will be filled 188 // as if it were a native compiled frame. 189 // 190 // Case (2) is similar to the way interpreter frames are processed in 191 // vframeStreamCommon::fill_from_interpreter_frame in case no valid BCI 192 // was found for an interpreted frame. If asserts are enabled, the assert 193 // in found_bad_method_frame() will be triggered. If asserts are disabled, 194 // the vframeStreamCommon object will be filled afterwards as if the 195 // interpreter were at the point of entering into the method. 196 return false; 197 } 198 199 // This PcDesc is useful however we must adjust the frame's pc 200 // so that the vframeStream lookups will use this same pc 201 fr->set_pc(pc_desc->real_pc(nm)); 202 return true; 203 } 204 205 206 // Determine if 'fr' is a walkable interpreted frame. Returns false 207 // if it is not. *method_p, and *bci_p are not set when false is 208 // returned. *method_p is non-NULL if frame was executing a Java 209 // method. *bci_p is != -1 if a valid BCI in the Java method could 210 // be found. 211 // Note: this method returns true when a valid Java method is found 212 // even if a valid BCI cannot be found. 213 214 static bool is_decipherable_interpreted_frame(JavaThread* thread, 215 frame* fr, 216 Method** method_p, 217 int* bci_p) { 218 assert(fr->is_interpreted_frame(), "just checking"); 219 220 // top frame is an interpreted frame 221 // check if it is walkable (i.e. valid Method* and valid bci) 222 223 // Because we may be racing a gc thread the method and/or bci 224 // of a valid interpreter frame may look bad causing us to 225 // fail the is_interpreted_frame_valid test. If the thread 226 // is in any of the following states we are assured that the 227 // frame is in fact valid and we must have hit the race. 228 229 JavaThreadState state = thread->thread_state(); 230 bool known_valid = (state == _thread_in_native || 231 state == _thread_in_vm || 232 state == _thread_blocked ); 233 234 if (known_valid || fr->is_interpreted_frame_valid(thread)) { 235 236 // The frame code should completely validate the frame so that 237 // references to Method* and bci are completely safe to access 238 // If they aren't the frame code should be fixed not this 239 // code. However since gc isn't locked out the values could be 240 // stale. This is a race we can never completely win since we can't 241 // lock out gc so do one last check after retrieving their values 242 // from the frame for additional safety 243 244 Method* method = fr->interpreter_frame_method(); 245 246 // We've at least found a method. 247 // NOTE: there is something to be said for the approach that 248 // if we don't find a valid bci then the method is not likely 249 // a valid method. Then again we may have caught an interpreter 250 // frame in the middle of construction and the bci field is 251 // not yet valid. 252 if (!method->is_valid_method()) return false; 253 *method_p = method; // If the Method* found is invalid, it is 254 // ignored by forte_fill_call_trace_given_top(). 255 // So set method_p only if the Method is valid. 256 257 address bcp = fr->interpreter_frame_bcp(); 258 int bci = method->validate_bci_from_bcp(bcp); 259 260 // note: bci is set to -1 if not a valid bci 261 *bci_p = bci; 262 return true; 263 } 264 265 return false; 266 } 267 268 269 // Determine if a Java frame can be found starting with the frame 'fr'. 270 // 271 // Check the return value of find_initial_Java_frame and the value of 272 // 'method_p' to decide on how use the results returned by this method. 273 // 274 // If 'method_p' is not NULL, an initial Java frame has been found and 275 // the stack can be walked starting from that initial frame. In this case, 276 // 'method_p' points to the Method that the initial frame belongs to and 277 // the initial Java frame is returned in initial_frame_p. 278 // 279 // find_initial_Java_frame() returns true if a Method has been found (i.e., 280 // 'method_p' is not NULL) and the initial frame that belongs to that Method 281 // is decipherable. 282 // 283 // A frame is considered to be decipherable: 284 // 285 // - if the frame is a compiled frame and a PCDesc is available; 286 // 287 // - if the frame is an interpreter frame that is valid or the thread is 288 // state (_thread_in_native || state == _thread_in_vm || state == _thread_blocked). 289 // 290 // Note that find_initial_Java_frame() can return false even if an initial 291 // Java method was found (e.g., there is no PCDesc available for the method). 292 // 293 // If 'method_p' is NULL, it was not possible to find a Java frame when 294 // walking the stack starting from 'fr'. In this case find_initial_Java_frame 295 // returns false. 296 297 static bool find_initial_Java_frame(JavaThread* thread, 298 frame* fr, 299 frame* initial_frame_p, 300 Method** method_p, 301 int* bci_p) { 302 303 // It is possible that for a frame containing a compiled method 304 // we can capture the method but no bci. If we get no 305 // bci the frame isn't walkable but the method is usable. 306 // Therefore we init the returned Method* to NULL so the 307 // caller can make the distinction. 308 309 *method_p = NULL; 310 311 // On the initial call to this method the frame we get may not be 312 // recognizable to us. This should only happen if we are in a JRT_LEAF 313 // or something called by a JRT_LEAF method. 314 315 frame candidate = *fr; 316 317 // If the starting frame we were given has no codeBlob associated with 318 // it see if we can find such a frame because only frames with codeBlobs 319 // are possible Java frames. 320 321 if (fr->cb() == NULL) { 322 323 // See if we can find a useful frame 324 int loop_count; 325 int loop_max = MaxJavaStackTraceDepth * 2; 326 RegisterMap map(thread, false); 327 328 for (loop_count = 0; loop_max == 0 || loop_count < loop_max; loop_count++) { 329 if (!candidate.safe_for_sender(thread)) return false; 330 candidate = candidate.sender(&map); 331 if (candidate.cb() != NULL) break; 332 } 333 if (candidate.cb() == NULL) return false; 334 } 335 336 // We have a frame known to be in the codeCache 337 // We will hopefully be able to figure out something to do with it. 338 int loop_count; 339 int loop_max = MaxJavaStackTraceDepth * 2; 340 RegisterMap map(thread, false); 341 342 for (loop_count = 0; loop_max == 0 || loop_count < loop_max; loop_count++) { 343 344 if (candidate.is_entry_frame()) { 345 // jcw is NULL if the java call wrapper couldn't be found 346 JavaCallWrapper *jcw = candidate.entry_frame_call_wrapper_if_safe(thread); 347 // If initial frame is frame from StubGenerator and there is no 348 // previous anchor, there are no java frames associated with a method 349 if (jcw == NULL || jcw->is_first_frame()) { 350 return false; 351 } 352 } 353 354 if (candidate.is_interpreted_frame()) { 355 if (is_decipherable_interpreted_frame(thread, &candidate, method_p, bci_p)) { 356 *initial_frame_p = candidate; 357 return true; 358 } 359 360 // Hopefully we got some data 361 return false; 362 } 363 364 if (candidate.cb()->is_compiled()) { 365 366 CompiledMethod* nm = candidate.cb()->as_compiled_method(); 367 *method_p = nm->method(); 368 369 // If the frame is not decipherable, then the value of -1 370 // for the BCI is used to signal that no BCI is available. 371 // Furthermore, the method returns false in this case. 372 // 373 // If a decipherable frame is available, the BCI value will 374 // not be used. 375 376 *bci_p = -1; 377 378 *initial_frame_p = candidate; 379 380 // Native wrapper code is trivial to decode by vframeStream 381 382 if (nm->is_native_method()) return true; 383 384 // If the frame is not decipherable, then a PC was found 385 // that does not have a PCDesc from which a BCI can be obtained. 386 // Nevertheless, a Method was found. 387 388 if (!is_decipherable_compiled_frame(thread, &candidate, nm)) { 389 return false; 390 } 391 392 // is_decipherable_compiled_frame may modify candidate's pc 393 *initial_frame_p = candidate; 394 395 assert(nm->pc_desc_at(candidate.pc()) != NULL, "debug information must be available if the frame is decipherable"); 396 397 return true; 398 } 399 400 // Must be some stub frame that we don't care about 401 402 if (!candidate.safe_for_sender(thread)) return false; 403 candidate = candidate.sender(&map); 404 405 // If it isn't in the code cache something is wrong 406 // since once we find a frame in the code cache they 407 // all should be there. 408 409 if (candidate.cb() == NULL) return false; 410 411 } 412 413 return false; 414 415 } 416 417 static void forte_fill_call_trace_given_top(JavaThread* thd, 418 ASGCT_CallTrace* trace, 419 int depth, 420 frame top_frame) { 421 NoHandleMark nhm; 422 423 frame initial_Java_frame; 424 Method* method; 425 int bci = -1; // assume BCI is not available for method 426 // update with correct information if available 427 int count; 428 429 count = 0; 430 assert(trace->frames != NULL, "trace->frames must be non-NULL"); 431 432 // Walk the stack starting from 'top_frame' and search for an initial Java frame. 433 find_initial_Java_frame(thd, &top_frame, &initial_Java_frame, &method, &bci); 434 435 // Check if a Java Method has been found. 436 if (method == NULL) return; 437 438 if (!method->is_valid_method()) { 439 trace->num_frames = ticks_GC_active; // -2 440 return; 441 } 442 443 vframeStreamForte st(thd, initial_Java_frame, false); 444 445 for (; !st.at_end() && count < depth; st.forte_next(), count++) { 446 bci = st.bci(); 447 method = st.method(); 448 449 if (!method->is_valid_method()) { 450 // we throw away everything we've gathered in this sample since 451 // none of it is safe 452 trace->num_frames = ticks_GC_active; // -2 453 return; 454 } 455 456 trace->frames[count].method_id = method->find_jmethod_id_or_null(); 457 if (!method->is_native()) { 458 trace->frames[count].lineno = bci; 459 } else { 460 trace->frames[count].lineno = -3; 461 } 462 } 463 trace->num_frames = count; 464 return; 465 } 466 467 468 // Forte Analyzer AsyncGetCallTrace() entry point. Currently supported 469 // on Linux X86, Solaris SPARC and Solaris X86. 470 // 471 // Async-safe version of GetCallTrace being called from a signal handler 472 // when a LWP gets interrupted by SIGPROF but the stack traces are filled 473 // with different content (see below). 474 // 475 // This function must only be called when JVM/TI 476 // CLASS_LOAD events have been enabled since agent startup. The enabled 477 // event will cause the jmethodIDs to be allocated at class load time. 478 // The jmethodIDs cannot be allocated in a signal handler because locks 479 // cannot be grabbed in a signal handler safely. 480 // 481 // void (*AsyncGetCallTrace)(ASGCT_CallTrace *trace, jint depth, void* ucontext) 482 // 483 // Called by the profiler to obtain the current method call stack trace for 484 // a given thread. The thread is identified by the env_id field in the 485 // ASGCT_CallTrace structure. The profiler agent should allocate a ASGCT_CallTrace 486 // structure with enough memory for the requested stack depth. The VM fills in 487 // the frames buffer and the num_frames field. 488 // 489 // Arguments: 490 // 491 // trace - trace data structure to be filled by the VM. 492 // depth - depth of the call stack trace. 493 // ucontext - ucontext_t of the LWP 494 // 495 // ASGCT_CallTrace: 496 // typedef struct { 497 // JNIEnv *env_id; 498 // jint num_frames; 499 // ASGCT_CallFrame *frames; 500 // } ASGCT_CallTrace; 501 // 502 // Fields: 503 // env_id - ID of thread which executed this trace. 504 // num_frames - number of frames in the trace. 505 // (< 0 indicates the frame is not walkable). 506 // frames - the ASGCT_CallFrames that make up this trace. Callee followed by callers. 507 // 508 // ASGCT_CallFrame: 509 // typedef struct { 510 // jint lineno; 511 // jmethodID method_id; 512 // } ASGCT_CallFrame; 513 // 514 // Fields: 515 // 1) For Java frame (interpreted and compiled), 516 // lineno - bci of the method being executed or -1 if bci is not available 517 // method_id - jmethodID of the method being executed 518 // 2) For native method 519 // lineno - (-3) 520 // method_id - jmethodID of the method being executed 521 522 extern "C" { 523 JNIEXPORT 524 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) { 525 JavaThread* thread; 526 527 if (trace->env_id == NULL || 528 (thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL || 529 thread->is_exiting()) { 530 531 // bad env_id, thread has exited or thread is exiting 532 trace->num_frames = ticks_thread_exit; // -8 533 return; 534 } 535 536 if (thread->in_deopt_handler()) { 537 // thread is in the deoptimization handler so return no frames 538 trace->num_frames = ticks_deopt; // -9 539 return; 540 } 541 542 assert(JavaThread::current() == thread, 543 "AsyncGetCallTrace must be called by the current interrupted thread"); 544 545 if (!JvmtiExport::should_post_class_load()) { 546 trace->num_frames = ticks_no_class_load; // -1 547 return; 548 } 549 550 if (Universe::heap()->is_gc_active()) { 551 trace->num_frames = ticks_GC_active; // -2 552 return; 553 } 554 555 switch (thread->thread_state()) { 556 case _thread_new: 557 case _thread_uninitialized: 558 case _thread_new_trans: 559 // We found the thread on the threads list above, but it is too 560 // young to be useful so return that there are no Java frames. 561 trace->num_frames = 0; 562 break; 563 case _thread_in_native: 564 case _thread_in_native_trans: 565 case _thread_blocked: 566 case _thread_blocked_trans: 567 case _thread_in_vm: 568 case _thread_in_vm_trans: 569 { 570 frame fr; 571 572 // param isInJava == false - indicate we aren't in Java code 573 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) { 574 trace->num_frames = ticks_unknown_not_Java; // -3 unknown frame 575 } else { 576 if (!thread->has_last_Java_frame()) { 577 trace->num_frames = 0; // No Java frames 578 } else { 579 trace->num_frames = ticks_not_walkable_not_Java; // -4 non walkable frame by default 580 forte_fill_call_trace_given_top(thread, trace, depth, fr); 581 582 // This assert would seem to be valid but it is not. 583 // It would be valid if we weren't possibly racing a gc 584 // thread. A gc thread can make a valid interpreted frame 585 // look invalid. It's a small window but it does happen. 586 // The assert is left here commented out as a reminder. 587 // assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable"); 588 589 } 590 } 591 } 592 break; 593 case _thread_in_Java: 594 case _thread_in_Java_trans: 595 { 596 frame fr; 597 598 // param isInJava == true - indicate we are in Java code 599 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) { 600 trace->num_frames = ticks_unknown_Java; // -5 unknown frame 601 } else { 602 trace->num_frames = ticks_not_walkable_Java; // -6, non walkable frame by default 603 forte_fill_call_trace_given_top(thread, trace, depth, fr); 604 } 605 } 606 break; 607 default: 608 // Unknown thread state 609 trace->num_frames = ticks_unknown_state; // -7 610 break; 611 } 612 } 613 614 615 #ifndef _WINDOWS 616 // Support for the Forte(TM) Peformance Tools collector. 617 // 618 // The method prototype is derived from libcollector.h. For more 619 // information, please see the libcollect man page. 620 621 // Method to let libcollector know about a dynamically loaded function. 622 // Because it is weakly bound, the calls become NOP's when the library 623 // isn't present. 624 #ifdef __APPLE__ 625 // XXXDARWIN: Link errors occur even when __attribute__((weak_import)) 626 // is added 627 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) ((void) 0) 628 #else 629 void collector_func_load(char* name, 630 void* null_argument_1, 631 void* null_argument_2, 632 void *vaddr, 633 int size, 634 int zero_argument, 635 void* null_argument_3); 636 #pragma weak collector_func_load 637 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) \ 638 ( collector_func_load ? collector_func_load(x0,x1,x2,x3,x4,x5,x6),(void)0 : (void)0 ) 639 #endif // __APPLE__ 640 #endif // !_WINDOWS 641 642 } // end extern "C" 643 #endif // !IA64 && !PPC64 644 645 void Forte::register_stub(const char* name, address start, address end) { 646 #if !defined(_WINDOWS) && !defined(IA64) && !defined(PPC64) 647 assert(pointer_delta(end, start, sizeof(jbyte)) < INT_MAX, 648 "Code size exceeds maximum range"); 649 650 collector_func_load((char*)name, NULL, NULL, start, 651 pointer_delta(end, start, sizeof(jbyte)), 0, NULL); 652 #endif // !_WINDOWS && !IA64 && !PPC64 653 } 654 655 #else // INCLUDE_JVMTI 656 extern "C" { 657 JNIEXPORT 658 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) { 659 trace->num_frames = ticks_no_class_load; // -1 660 } 661 } 662 #endif // INCLUDE_JVMTI