1 /* 2 * Copyright (c) 2003, 2013, 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_interface/collectedHeap.inline.hpp" 29 #include "memory/space.hpp" 30 #include "memory/universe.inline.hpp" 31 #include "oops/oop.inline.hpp" 32 #include "oops/oop.inline2.hpp" 33 #include "prims/forte.hpp" 34 #include "runtime/javaCalls.hpp" 35 #include "runtime/thread.inline.hpp" 36 #include "runtime/vframe.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, nmethod* 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_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 nmethod. 149 150 static bool is_decipherable_compiled_frame(JavaThread* thread, frame* fr, nmethod* 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 nmethod 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 intptr_t bcx = fr->interpreter_frame_bcx(); 258 259 int bci = method->validate_bci_from_bcx(bcx); 260 261 // note: bci is set to -1 if not a valid bci 262 *bci_p = bci; 263 return true; 264 } 265 266 return false; 267 } 268 269 270 // Determine if a Java frame can be found starting with the frame 'fr'. 271 // 272 // Check the return value of find_initial_Java_frame and the value of 273 // 'method_p' to decide on how use the results returned by this method. 274 // 275 // If 'method_p' is not NULL, an initial Java frame has been found and 276 // the stack can be walked starting from that initial frame. In this case, 277 // 'method_p' points to the Method that the initial frame belongs to and 278 // the initial Java frame is returned in initial_frame_p. 279 // 280 // find_initial_Java_frame() returns true if a Method has been found (i.e., 281 // 'method_p' is not NULL) and the initial frame that belongs to that Method 282 // is decipherable. 283 // 284 // A frame is considered to be decipherable: 285 // 286 // - if the frame is a compiled frame and a PCDesc is available; 287 // 288 // - if the frame is an interpreter frame that is valid or the thread is 289 // state (_thread_in_native || state == _thread_in_vm || state == _thread_blocked). 290 // 291 // Note that find_initial_Java_frame() can return false even if an initial 292 // Java method was found (e.g., there is no PCDesc available for the method). 293 // 294 // If 'method_p' is NULL, it was not possible to find a Java frame when 295 // walking the stack starting from 'fr'. In this case find_initial_Java_frame 296 // returns false. 297 298 static bool find_initial_Java_frame(JavaThread* thread, 299 frame* fr, 300 frame* initial_frame_p, 301 Method** method_p, 302 int* bci_p) { 303 304 // It is possible that for a frame containing an nmethod 305 // we can capture the method but no bci. If we get no 306 // bci the frame isn't walkable but the method is usable. 307 // Therefore we init the returned Method* to NULL so the 308 // caller can make the distinction. 309 310 *method_p = NULL; 311 312 // On the initial call to this method the frame we get may not be 313 // recognizable to us. This should only happen if we are in a JRT_LEAF 314 // or something called by a JRT_LEAF method. 315 316 frame candidate = *fr; 317 318 // If the starting frame we were given has no codeBlob associated with 319 // it see if we can find such a frame because only frames with codeBlobs 320 // are possible Java frames. 321 322 if (fr->cb() == NULL) { 323 324 // See if we can find a useful frame 325 int loop_count; 326 int loop_max = MaxJavaStackTraceDepth * 2; 327 RegisterMap map(thread, false); 328 329 for (loop_count = 0; loop_count < loop_max; loop_count++) { 330 if (!candidate.safe_for_sender(thread)) return false; 331 candidate = candidate.sender(&map); 332 if (candidate.cb() != NULL) break; 333 } 334 if (candidate.cb() == NULL) return false; 335 } 336 337 // We have a frame known to be in the codeCache 338 // We will hopefully be able to figure out something to do with it. 339 int loop_count; 340 int loop_max = MaxJavaStackTraceDepth * 2; 341 RegisterMap map(thread, false); 342 343 for (loop_count = 0; loop_count < loop_max; loop_count++) { 344 345 if (candidate.is_entry_frame()) { 346 // jcw is NULL if the java call wrapper couldn't be found 347 JavaCallWrapper *jcw = candidate.entry_frame_call_wrapper_if_safe(thread); 348 // If initial frame is frame from StubGenerator and there is no 349 // previous anchor, there are no java frames associated with a method 350 if (jcw == NULL || jcw->is_first_frame()) { 351 return false; 352 } 353 } 354 355 if (candidate.is_interpreted_frame()) { 356 if (is_decipherable_interpreted_frame(thread, &candidate, method_p, bci_p)) { 357 *initial_frame_p = candidate; 358 return true; 359 } 360 361 // Hopefully we got some data 362 return false; 363 } 364 365 if (candidate.cb()->is_nmethod()) { 366 367 nmethod* nm = (nmethod*) candidate.cb(); 368 *method_p = nm->method(); 369 370 // If the frame is not decipherable, then the value of -1 371 // for the BCI is used to signal that no BCI is available. 372 // Furthermore, the method returns false in this case. 373 // 374 // If a decipherable frame is available, the BCI value will 375 // not be used. 376 377 *bci_p = -1; 378 379 *initial_frame_p = candidate; 380 381 // Native wrapper code is trivial to decode by vframeStream 382 383 if (nm->is_native_method()) return true; 384 385 // If the frame is not decipherable, then a PC was found 386 // that does not have a PCDesc from which a BCI can be obtained. 387 // Nevertheless, a Method was found. 388 389 if (!is_decipherable_compiled_frame(thread, &candidate, nm)) { 390 return false; 391 } 392 393 // is_decipherable_compiled_frame may modify candidate's pc 394 *initial_frame_p = candidate; 395 396 assert(nm->pc_desc_at(candidate.pc()) != NULL, "debug information must be available if the frame is decipherable"); 397 398 return true; 399 } 400 401 // Must be some stub frame that we don't care about 402 403 if (!candidate.safe_for_sender(thread)) return false; 404 candidate = candidate.sender(&map); 405 406 // If it isn't in the code cache something is wrong 407 // since once we find a frame in the code cache they 408 // all should be there. 409 410 if (candidate.cb() == NULL) return false; 411 412 } 413 414 return false; 415 416 } 417 418 static void forte_fill_call_trace_given_top(JavaThread* thd, 419 ASGCT_CallTrace* trace, 420 int depth, 421 frame top_frame) { 422 NoHandleMark nhm; 423 424 frame initial_Java_frame; 425 Method* method; 426 int bci = -1; // assume BCI is not available for method 427 // update with correct information if available 428 int count; 429 430 count = 0; 431 assert(trace->frames != NULL, "trace->frames must be non-NULL"); 432 433 // Walk the stack starting from 'top_frame' and search for an initial Java frame. 434 find_initial_Java_frame(thd, &top_frame, &initial_Java_frame, &method, &bci); 435 436 // Check if a Java Method has been found. 437 if (method == NULL) return; 438 439 if (!method->is_valid_method()) { 440 trace->num_frames = ticks_GC_active; // -2 441 return; 442 } 443 444 vframeStreamForte st(thd, initial_Java_frame, false); 445 446 for (; !st.at_end() && count < depth; st.forte_next(), count++) { 447 bci = st.bci(); 448 method = st.method(); 449 450 if (!method->is_valid_method()) { 451 // we throw away everything we've gathered in this sample since 452 // none of it is safe 453 trace->num_frames = ticks_GC_active; // -2 454 return; 455 } 456 457 trace->frames[count].method_id = method->find_jmethod_id_or_null(); 458 if (!method->is_native()) { 459 trace->frames[count].lineno = bci; 460 } else { 461 trace->frames[count].lineno = -3; 462 } 463 } 464 trace->num_frames = count; 465 return; 466 } 467 468 469 // Forte Analyzer AsyncGetCallTrace() entry point. Currently supported 470 // on Linux X86, Solaris SPARC and Solaris X86. 471 // 472 // Async-safe version of GetCallTrace being called from a signal handler 473 // when a LWP gets interrupted by SIGPROF but the stack traces are filled 474 // with different content (see below). 475 // 476 // This function must only be called when JVM/TI 477 // CLASS_LOAD events have been enabled since agent startup. The enabled 478 // event will cause the jmethodIDs to be allocated at class load time. 479 // The jmethodIDs cannot be allocated in a signal handler because locks 480 // cannot be grabbed in a signal handler safely. 481 // 482 // void (*AsyncGetCallTrace)(ASGCT_CallTrace *trace, jint depth, void* ucontext) 483 // 484 // Called by the profiler to obtain the current method call stack trace for 485 // a given thread. The thread is identified by the env_id field in the 486 // ASGCT_CallTrace structure. The profiler agent should allocate a ASGCT_CallTrace 487 // structure with enough memory for the requested stack depth. The VM fills in 488 // the frames buffer and the num_frames field. 489 // 490 // Arguments: 491 // 492 // trace - trace data structure to be filled by the VM. 493 // depth - depth of the call stack trace. 494 // ucontext - ucontext_t of the LWP 495 // 496 // ASGCT_CallTrace: 497 // typedef struct { 498 // JNIEnv *env_id; 499 // jint num_frames; 500 // ASGCT_CallFrame *frames; 501 // } ASGCT_CallTrace; 502 // 503 // Fields: 504 // env_id - ID of thread which executed this trace. 505 // num_frames - number of frames in the trace. 506 // (< 0 indicates the frame is not walkable). 507 // frames - the ASGCT_CallFrames that make up this trace. Callee followed by callers. 508 // 509 // ASGCT_CallFrame: 510 // typedef struct { 511 // jint lineno; 512 // jmethodID method_id; 513 // } ASGCT_CallFrame; 514 // 515 // Fields: 516 // 1) For Java frame (interpreted and compiled), 517 // lineno - bci of the method being executed or -1 if bci is not available 518 // method_id - jmethodID of the method being executed 519 // 2) For native method 520 // lineno - (-3) 521 // method_id - jmethodID of the method being executed 522 523 extern "C" { 524 JNIEXPORT 525 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) { 526 JavaThread* thread; 527 528 if (trace->env_id == NULL || 529 (thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL || 530 thread->is_exiting()) { 531 532 // bad env_id, thread has exited or thread is exiting 533 trace->num_frames = ticks_thread_exit; // -8 534 return; 535 } 536 537 if (thread->in_deopt_handler()) { 538 // thread is in the deoptimization handler so return no frames 539 trace->num_frames = ticks_deopt; // -9 540 return; 541 } 542 543 assert(JavaThread::current() == thread, 544 "AsyncGetCallTrace must be called by the current interrupted thread"); 545 546 if (!JvmtiExport::should_post_class_load()) { 547 trace->num_frames = ticks_no_class_load; // -1 548 return; 549 } 550 551 if (Universe::heap()->is_gc_active()) { 552 trace->num_frames = ticks_GC_active; // -2 553 return; 554 } 555 556 switch (thread->thread_state()) { 557 case _thread_new: 558 case _thread_uninitialized: 559 case _thread_new_trans: 560 // We found the thread on the threads list above, but it is too 561 // young to be useful so return that there are no Java frames. 562 trace->num_frames = 0; 563 break; 564 case _thread_in_native: 565 case _thread_in_native_trans: 566 case _thread_blocked: 567 case _thread_blocked_trans: 568 case _thread_in_vm: 569 case _thread_in_vm_trans: 570 { 571 frame fr; 572 573 // param isInJava == false - indicate we aren't in Java code 574 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) { 575 trace->num_frames = ticks_unknown_not_Java; // -3 unknown frame 576 } else { 577 if (!thread->has_last_Java_frame()) { 578 trace->num_frames = 0; // No Java frames 579 } else { 580 trace->num_frames = ticks_not_walkable_not_Java; // -4 non walkable frame by default 581 forte_fill_call_trace_given_top(thread, trace, depth, fr); 582 583 // This assert would seem to be valid but it is not. 584 // It would be valid if we weren't possibly racing a gc 585 // thread. A gc thread can make a valid interpreted frame 586 // look invalid. It's a small window but it does happen. 587 // The assert is left here commented out as a reminder. 588 // assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable"); 589 590 } 591 } 592 } 593 break; 594 case _thread_in_Java: 595 case _thread_in_Java_trans: 596 { 597 frame fr; 598 599 // param isInJava == true - indicate we are in Java code 600 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) { 601 trace->num_frames = ticks_unknown_Java; // -5 unknown frame 602 } else { 603 trace->num_frames = ticks_not_walkable_Java; // -6, non walkable frame by default 604 forte_fill_call_trace_given_top(thread, trace, depth, fr); 605 } 606 } 607 break; 608 default: 609 // Unknown thread state 610 trace->num_frames = ticks_unknown_state; // -7 611 break; 612 } 613 } 614 615 616 #ifndef _WINDOWS 617 // Support for the Forte(TM) Peformance Tools collector. 618 // 619 // The method prototype is derived from libcollector.h. For more 620 // information, please see the libcollect man page. 621 622 // Method to let libcollector know about a dynamically loaded function. 623 // Because it is weakly bound, the calls become NOP's when the library 624 // isn't present. 625 #ifdef __APPLE__ 626 // XXXDARWIN: Link errors occur even when __attribute__((weak_import)) 627 // is added 628 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) (0) 629 #else 630 void collector_func_load(char* name, 631 void* null_argument_1, 632 void* null_argument_2, 633 void *vaddr, 634 int size, 635 int zero_argument, 636 void* null_argument_3); 637 #pragma weak collector_func_load 638 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) \ 639 ( collector_func_load ? collector_func_load(x0,x1,x2,x3,x4,x5,x6),(void)0 : (void)0 ) 640 #endif // __APPLE__ 641 #endif // !_WINDOWS 642 643 } // end extern "C" 644 #endif // !IA64 && !PPC64 645 646 void Forte::register_stub(const char* name, address start, address end) { 647 #if !defined(_WINDOWS) && !defined(IA64) && !defined(PPC64) 648 assert(pointer_delta(end, start, sizeof(jbyte)) < INT_MAX, 649 "Code size exceeds maximum range"); 650 651 collector_func_load((char*)name, NULL, NULL, start, 652 pointer_delta(end, start, sizeof(jbyte)), 0, NULL); 653 #endif // !_WINDOWS && !IA64 && !PPC64 654 } 655 656 #else // INCLUDE_JVMTI 657 extern "C" { 658 JNIEXPORT 659 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) { 660 trace->num_frames = ticks_no_class_load; // -1 661 } 662 } 663 #endif // INCLUDE_JVMTI