1 /*
   2  * Copyright (c) 2012, 2019, 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/nmethod.hpp"
  28 #include "code/pcDesc.hpp"
  29 #include "jfr/periodic/sampling/jfrCallTrace.hpp"
  30 #include "jfr/recorder/service/jfrOptionSet.hpp"
  31 #include "oops/method.hpp"
  32 #include "runtime/javaCalls.hpp"
  33 #include "runtime/frame.inline.hpp"
  34 #include "runtime/registerMap.hpp"
  35 #include "runtime/thread.inline.hpp"
  36 
  37 bool JfrGetCallTrace::find_top_frame(frame& top_frame, Method** method, frame& first_frame) {
  38   assert(top_frame.cb() != NULL, "invariant");
  39   RegisterMap map(_thread, false);
  40   frame candidate = top_frame;
  41   for (u4 i = 0; i < (JfrOptionSet::stackdepth() * 2); ++i) {
  42     if (candidate.is_entry_frame()) {
  43       JavaCallWrapper *jcw = candidate.entry_frame_call_wrapper_if_safe(_thread);
  44       if (jcw == NULL || jcw->is_first_frame()) {
  45         return false;
  46       }
  47     }
  48 
  49     if (candidate.is_interpreted_frame()) {
  50       JavaThreadState state = _thread->thread_state();
  51       const bool known_valid = (state == _thread_in_native || state == _thread_in_vm || state == _thread_blocked);
  52       if (known_valid || candidate.is_interpreted_frame_valid(_thread)) {
  53         Method* im = candidate.interpreter_frame_method();
  54         if (known_valid && !Method::is_valid_method(im)) {
  55           return false;
  56         }
  57         *method = im;
  58         first_frame = candidate;
  59         return true;
  60       }
  61     }
  62 
  63     if (candidate.cb()->is_nmethod()) {
  64       // first check to make sure that we have a sane stack,
  65       // the PC is actually inside the code part of the codeBlob,
  66       // and we are past is_frame_complete_at (stack has been setup)
  67       if (!candidate.safe_for_sender(_thread)) {
  68         return false;
  69       }
  70       nmethod* nm = (nmethod*)candidate.cb();
  71       *method = nm->method();
  72 
  73       if (_in_java) {
  74         PcDesc* pc_desc = nm->pc_desc_near(candidate.pc() + 1);
  75         if (pc_desc == NULL || pc_desc->scope_decode_offset() == DebugInformationRecorder::serialized_null) {
  76           return false;
  77         }
  78         candidate.set_pc(pc_desc->real_pc(nm));
  79         assert(nm->pc_desc_at(candidate.pc()) != NULL, "invalid pc");
  80       }
  81       first_frame = candidate;
  82       return true;
  83     }
  84 
  85     if (!candidate.safe_for_sender(_thread) ||
  86       candidate.is_stub_frame() ||
  87       candidate.cb()->frame_size() <= 0) {
  88       return false;
  89     }
  90 
  91     candidate = candidate.sender(&map);
  92     if (candidate.cb() == NULL) {
  93       return false;
  94     }
  95   }
  96   return false;
  97 }
  98 
  99 bool JfrGetCallTrace::get_topframe(void* ucontext, frame& topframe) {
 100   if (!_thread->pd_get_top_frame_for_profiling(&topframe, ucontext, _in_java)) {
 101     return false;
 102   }
 103 
 104   if (topframe.cb() == NULL) {
 105     return false;
 106   }
 107 
 108   frame first_java_frame;
 109   Method* method = NULL;
 110   if (find_top_frame(topframe, &method, first_java_frame)) {
 111     if (method == NULL) {
 112       return false;
 113     }
 114     topframe = first_java_frame;
 115     return true;
 116   }
 117   return false;
 118 }