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 available for this pc 176 // vframeStream would explode if we try and walk the frames. 177 return false; 178 } 179 180 // This PcDesc is useful however we must adjust the frame's pc 181 // so that the vframeStream lookups will use this same pc 182 fr->set_pc(pc_desc->real_pc(nm)); 183 return true; 184 } 185 186 187 // Determine if 'fr' is a walkable interpreted frame. Returns false 188 // if it is not. *method_p, and *bci_p are not set when false is 189 // returned. *method_p is non-NULL if frame was executing a Java 190 // method. *bci_p is != -1 if a valid BCI in the Java method could 191 // be found. 192 // Note: this method returns true when a valid Java method is found 193 // even if a valid BCI cannot be found. 194 195 static bool is_decipherable_interpreted_frame(JavaThread* thread, 196 frame* fr, 197 Method** method_p, 198 int* bci_p) { 199 assert(fr->is_interpreted_frame(), "just checking"); 200 201 // top frame is an interpreted frame 202 // check if it is walkable (i.e. valid Method* and valid bci) 203 204 // Because we may be racing a gc thread the method and/or bci 205 // of a valid interpreter frame may look bad causing us to 206 // fail the is_interpreted_frame_valid test. If the thread 207 // is in any of the following states we are assured that the 208 // frame is in fact valid and we must have hit the race. 209 210 JavaThreadState state = thread->thread_state(); 211 bool known_valid = (state == _thread_in_native || 212 state == _thread_in_vm || 213 state == _thread_blocked ); 214 215 if (known_valid || fr->is_interpreted_frame_valid(thread)) { 216 217 // The frame code should completely validate the frame so that 218 // references to Method* and bci are completely safe to access 219 // If they aren't the frame code should be fixed not this 220 // code. However since gc isn't locked out the values could be 221 // stale. This is a race we can never completely win since we can't 222 // lock out gc so do one last check after retrieving their values 223 // from the frame for additional safety 224 225 Method* method = fr->interpreter_frame_method(); 226 227 // We've at least found a method. 228 // NOTE: there is something to be said for the approach that 229 // if we don't find a valid bci then the method is not likely 230 // a valid method. Then again we may have caught an interpreter 231 // frame in the middle of construction and the bci field is 232 // not yet valid. 233 234 *method_p = method; 235 if (!method->is_valid_method()) return false; 236 237 intptr_t bcx = fr->interpreter_frame_bcx(); 238 239 int bci = method->validate_bci_from_bcx(bcx); 240 241 // note: bci is set to -1 if not a valid bci 242 *bci_p = bci; 243 return true; 244 } 245 246 return false; 247 } 248 249 250 // Determine if 'fr' can be used to find an initial Java frame. 251 // Return false if it can not find a fully decipherable Java frame 252 // (in other words a frame that isn't safe to use in a vframe stream). 253 // Obviously if it can't even find a Java frame false will also be returned. 254 // 255 // If we find a Java frame decipherable or not then by definition we have 256 // identified a method and that will be returned to the caller via method_p. 257 // If we can determine a bci that is returned also. (Hmm is it possible 258 // to return a method and bci and still return false? ) 259 // 260 // The initial Java frame we find (if any) is return via initial_frame_p. 261 // 262 263 static bool find_initial_Java_frame(JavaThread* thread, 264 frame* fr, 265 frame* initial_frame_p, 266 Method** method_p, 267 int* bci_p) { 268 269 // It is possible that for a frame containing an nmethod 270 // we can capture the method but no bci. If we get no 271 // bci the frame isn't walkable but the method is usable. 272 // Therefore we init the returned Method* to NULL so the 273 // caller can make the distinction. 274 275 *method_p = NULL; 276 277 // On the initial call to this method the frame we get may not be 278 // recognizable to us. This should only happen if we are in a JRT_LEAF 279 // or something called by a JRT_LEAF method. 280 281 282 283 frame candidate = *fr; 284 285 // If the starting frame we were given has no codeBlob associated with 286 // it see if we can find such a frame because only frames with codeBlobs 287 // are possible Java frames. 288 289 if (fr->cb() == NULL) { 290 291 // See if we can find a useful frame 292 int loop_count; 293 int loop_max = MaxJavaStackTraceDepth * 2; 294 RegisterMap map(thread, false); 295 296 for (loop_count = 0; loop_count < loop_max; loop_count++) { 297 if (!candidate.safe_for_sender(thread)) return false; 298 candidate = candidate.sender(&map); 299 if (candidate.cb() != NULL) break; 300 } 301 if (candidate.cb() == NULL) return false; 302 } 303 304 // We have a frame known to be in the codeCache 305 // We will hopefully be able to figure out something to do with it. 306 int loop_count; 307 int loop_max = MaxJavaStackTraceDepth * 2; 308 RegisterMap map(thread, false); 309 310 for (loop_count = 0; loop_count < loop_max; loop_count++) { 311 312 if (candidate.is_entry_frame()) { 313 // jcw is NULL if the java call wrapper couldn't be found 314 JavaCallWrapper *jcw = candidate.entry_frame_call_wrapper_if_safe(thread); 315 // If initial frame is frame from StubGenerator and there is no 316 // previous anchor, there are no java frames associated with a method 317 if (jcw == NULL || jcw->is_first_frame()) { 318 return false; 319 } 320 } 321 322 if (candidate.is_interpreted_frame()) { 323 if (is_decipherable_interpreted_frame(thread, &candidate, method_p, bci_p)) { 324 *initial_frame_p = candidate; 325 return true; 326 } 327 328 // Hopefully we got some data 329 return false; 330 } 331 332 if (candidate.cb()->is_nmethod()) { 333 334 nmethod* nm = (nmethod*) candidate.cb(); 335 *method_p = nm->method(); 336 337 // If the frame isn't fully decipherable then the default 338 // value for the bci is a signal that we don't have a bci. 339 // If we have a decipherable frame this bci value will 340 // not be used. 341 342 *bci_p = -1; 343 344 *initial_frame_p = candidate; 345 346 // Native wrapper code is trivial to decode by vframeStream 347 348 if (nm->is_native_method()) return true; 349 350 // If it isn't decipherable then we have found a pc that doesn't 351 // have a PCDesc that can get us a bci however we did find 352 // a method 353 354 if (!is_decipherable_compiled_frame(thread, &candidate, nm)) { 355 return false; 356 } 357 358 // is_decipherable_compiled_frame may modify candidate's pc 359 *initial_frame_p = candidate; 360 361 assert(nm->pc_desc_at(candidate.pc()) != NULL, "if it's decipherable then pc must be valid"); 362 363 return true; 364 } 365 366 // Must be some stub frame that we don't care about 367 368 if (!candidate.safe_for_sender(thread)) return false; 369 candidate = candidate.sender(&map); 370 371 // If it isn't in the code cache something is wrong 372 // since once we find a frame in the code cache they 373 // all should be there. 374 375 if (candidate.cb() == NULL) return false; 376 377 } 378 379 return false; 380 381 } 382 383 static void forte_fill_call_trace_given_top(JavaThread* thd, 384 ASGCT_CallTrace* trace, 385 int depth, 386 frame top_frame) { 387 NoHandleMark nhm; 388 389 frame initial_Java_frame; 390 Method* method; 391 int bci; 392 int count; 393 394 count = 0; 395 assert(trace->frames != NULL, "trace->frames must be non-NULL"); 396 397 bool fully_decipherable = find_initial_Java_frame(thd, &top_frame, &initial_Java_frame, &method, &bci); 398 399 // The frame might not be walkable but still recovered a method 400 // (e.g. an nmethod with no scope info for the pc) 401 402 if (method == NULL) return; 403 404 if (!method->is_valid_method()) { 405 trace->num_frames = ticks_GC_active; // -2 406 return; 407 } 408 409 // We got a Java frame however it isn't fully decipherable 410 // so it won't necessarily be safe to use it for the 411 // initial frame in the vframe stream. 412 413 if (!fully_decipherable) { 414 // Take whatever method the top-frame decoder managed to scrape up. 415 // We look further at the top frame only if non-safepoint 416 // debugging information is available. 417 count++; 418 trace->num_frames = count; 419 trace->frames[0].method_id = method->find_jmethod_id_or_null(); 420 if (!method->is_native()) { 421 trace->frames[0].lineno = bci; 422 } else { 423 trace->frames[0].lineno = -3; 424 } 425 426 if (!initial_Java_frame.safe_for_sender(thd)) return; 427 428 RegisterMap map(thd, false); 429 initial_Java_frame = initial_Java_frame.sender(&map); 430 } 431 432 vframeStreamForte st(thd, initial_Java_frame, false); 433 434 for (; !st.at_end() && count < depth; st.forte_next(), count++) { 435 bci = st.bci(); 436 method = st.method(); 437 438 if (!method->is_valid_method()) { 439 // we throw away everything we've gathered in this sample since 440 // none of it is safe 441 trace->num_frames = ticks_GC_active; // -2 442 return; 443 } 444 445 trace->frames[count].method_id = method->find_jmethod_id_or_null(); 446 if (!method->is_native()) { 447 trace->frames[count].lineno = bci; 448 } else { 449 trace->frames[count].lineno = -3; 450 } 451 } 452 trace->num_frames = count; 453 return; 454 } 455 456 457 // Forte Analyzer AsyncGetCallTrace() entry point. Currently supported 458 // on Linux X86, Solaris SPARC and Solaris X86. 459 // 460 // Async-safe version of GetCallTrace being called from a signal handler 461 // when a LWP gets interrupted by SIGPROF but the stack traces are filled 462 // with different content (see below). 463 // 464 // This function must only be called when JVM/TI 465 // CLASS_LOAD events have been enabled since agent startup. The enabled 466 // event will cause the jmethodIDs to be allocated at class load time. 467 // The jmethodIDs cannot be allocated in a signal handler because locks 468 // cannot be grabbed in a signal handler safely. 469 // 470 // void (*AsyncGetCallTrace)(ASGCT_CallTrace *trace, jint depth, void* ucontext) 471 // 472 // Called by the profiler to obtain the current method call stack trace for 473 // a given thread. The thread is identified by the env_id field in the 474 // ASGCT_CallTrace structure. The profiler agent should allocate a ASGCT_CallTrace 475 // structure with enough memory for the requested stack depth. The VM fills in 476 // the frames buffer and the num_frames field. 477 // 478 // Arguments: 479 // 480 // trace - trace data structure to be filled by the VM. 481 // depth - depth of the call stack trace. 482 // ucontext - ucontext_t of the LWP 483 // 484 // ASGCT_CallTrace: 485 // typedef struct { 486 // JNIEnv *env_id; 487 // jint num_frames; 488 // ASGCT_CallFrame *frames; 489 // } ASGCT_CallTrace; 490 // 491 // Fields: 492 // env_id - ID of thread which executed this trace. 493 // num_frames - number of frames in the trace. 494 // (< 0 indicates the frame is not walkable). 495 // frames - the ASGCT_CallFrames that make up this trace. Callee followed by callers. 496 // 497 // ASGCT_CallFrame: 498 // typedef struct { 499 // jint lineno; 500 // jmethodID method_id; 501 // } ASGCT_CallFrame; 502 // 503 // Fields: 504 // 1) For Java frame (interpreted and compiled), 505 // lineno - bci of the method being executed or -1 if bci is not available 506 // method_id - jmethodID of the method being executed 507 // 2) For native method 508 // lineno - (-3) 509 // method_id - jmethodID of the method being executed 510 511 extern "C" { 512 JNIEXPORT 513 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) { 514 JavaThread* thread; 515 516 if (trace->env_id == NULL || 517 (thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL || 518 thread->is_exiting()) { 519 520 // bad env_id, thread has exited or thread is exiting 521 trace->num_frames = ticks_thread_exit; // -8 522 return; 523 } 524 525 if (thread->in_deopt_handler()) { 526 // thread is in the deoptimization handler so return no frames 527 trace->num_frames = ticks_deopt; // -9 528 return; 529 } 530 531 assert(JavaThread::current() == thread, 532 "AsyncGetCallTrace must be called by the current interrupted thread"); 533 534 if (!JvmtiExport::should_post_class_load()) { 535 trace->num_frames = ticks_no_class_load; // -1 536 return; 537 } 538 539 if (Universe::heap()->is_gc_active()) { 540 trace->num_frames = ticks_GC_active; // -2 541 return; 542 } 543 544 switch (thread->thread_state()) { 545 case _thread_new: 546 case _thread_uninitialized: 547 case _thread_new_trans: 548 // We found the thread on the threads list above, but it is too 549 // young to be useful so return that there are no Java frames. 550 trace->num_frames = 0; 551 break; 552 case _thread_in_native: 553 case _thread_in_native_trans: 554 case _thread_blocked: 555 case _thread_blocked_trans: 556 case _thread_in_vm: 557 case _thread_in_vm_trans: 558 { 559 frame fr; 560 561 // param isInJava == false - indicate we aren't in Java code 562 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) { 563 trace->num_frames = ticks_unknown_not_Java; // -3 unknown frame 564 } else { 565 if (!thread->has_last_Java_frame()) { 566 trace->num_frames = 0; // No Java frames 567 } else { 568 trace->num_frames = ticks_not_walkable_not_Java; // -4 non walkable frame by default 569 forte_fill_call_trace_given_top(thread, trace, depth, fr); 570 571 // This assert would seem to be valid but it is not. 572 // It would be valid if we weren't possibly racing a gc 573 // thread. A gc thread can make a valid interpreted frame 574 // look invalid. It's a small window but it does happen. 575 // The assert is left here commented out as a reminder. 576 // assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable"); 577 578 } 579 } 580 } 581 break; 582 case _thread_in_Java: 583 case _thread_in_Java_trans: 584 { 585 frame fr; 586 587 // param isInJava == true - indicate we are in Java code 588 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) { 589 trace->num_frames = ticks_unknown_Java; // -5 unknown frame 590 } else { 591 trace->num_frames = ticks_not_walkable_Java; // -6, non walkable frame by default 592 forte_fill_call_trace_given_top(thread, trace, depth, fr); 593 } 594 } 595 break; 596 default: 597 // Unknown thread state 598 trace->num_frames = ticks_unknown_state; // -7 599 break; 600 } 601 } 602 603 604 #ifndef _WINDOWS 605 // Support for the Forte(TM) Peformance Tools collector. 606 // 607 // The method prototype is derived from libcollector.h. For more 608 // information, please see the libcollect man page. 609 610 // Method to let libcollector know about a dynamically loaded function. 611 // Because it is weakly bound, the calls become NOP's when the library 612 // isn't present. 613 #ifdef __APPLE__ 614 // XXXDARWIN: Link errors occur even when __attribute__((weak_import)) 615 // is added 616 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) (0) 617 #else 618 void collector_func_load(char* name, 619 void* null_argument_1, 620 void* null_argument_2, 621 void *vaddr, 622 int size, 623 int zero_argument, 624 void* null_argument_3); 625 #pragma weak collector_func_load 626 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) \ 627 ( collector_func_load ? collector_func_load(x0,x1,x2,x3,x4,x5,x6),(void)0 : (void)0 ) 628 #endif // __APPLE__ 629 #endif // !_WINDOWS 630 631 } // end extern "C" 632 #endif // !IA64 && !PPC64 633 634 void Forte::register_stub(const char* name, address start, address end) { 635 #if !defined(_WINDOWS) && !defined(IA64) && !defined(PPC64) 636 assert(pointer_delta(end, start, sizeof(jbyte)) < INT_MAX, 637 "Code size exceeds maximum range"); 638 639 collector_func_load((char*)name, NULL, NULL, start, 640 pointer_delta(end, start, sizeof(jbyte)), 0, NULL); 641 #endif // !_WINDOWS && !IA64 && !PPC64 642 } 643 644 #else // INCLUDE_JVMTI 645 extern "C" { 646 JNIEXPORT 647 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) { 648 trace->num_frames = ticks_no_class_load; // -1 649 } 650 } 651 #endif // INCLUDE_JVMTI