1 /*
  2  * Copyright (c) 2003, 2020, 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 "memory/metaspaceShared.hpp"
 27 #include "runtime/frame.inline.hpp"
 28 #include "runtime/thread.inline.hpp"
 29 
 30 frame JavaThread::pd_last_frame() {
 31   assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
 32   vmassert(_anchor.last_Java_pc() != NULL, "not walkable");
 33   return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
 34 }
 35 
 36 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is
 37 // currently interrupted by SIGPROF
 38 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
 39   void* ucontext, bool isInJava) {
 40 
 41   assert(Thread::current() == this, "caller must be current thread");
 42   return pd_get_top_frame(fr_addr, ucontext, isInJava);
 43 }
 44 
 45 bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext, bool isInJava) {
 46   return pd_get_top_frame(fr_addr, ucontext, isInJava);
 47 }
 48 
 49 bool JavaThread::pd_get_top_frame(frame* fr_addr, void* ucontext, bool isInJava) {
 50 
 51   assert(this->is_Java_thread(), "must be JavaThread");
 52 
 53   JavaThread* jt = (JavaThread *)this;
 54 
 55   // If we have a last_Java_frame, then we should use it even if
 56   // isInJava == true.  It should be more reliable than CONTEXT info.
 57   if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
 58     *fr_addr = jt->pd_last_frame();
 59     return true;
 60   }
 61 
 62   // At this point, we don't have a last_Java_frame, so
 63   // we try to glean some information out of the CONTEXT
 64   // if we were running Java code when SIGPROF came in.
 65   if (isInJava) {
 66     frame ret_frame = os::fetch_frame_from_context(ucontext);
 67     if (ret_frame.pc() == NULL || ret_frame.sp() == NULL ) {
 68       // CONTEXT wasn't useful
 69       return false;
 70     }
 71 
 72     if (MetaspaceShared::is_in_trampoline_frame(ret_frame.pc())) {
 73       // In the middle of a trampoline call. Bail out for safety.
 74       // This happens rarely so shouldn't affect profiling.
 75       return false;
 76     }
 77 
 78     if (!ret_frame.safe_for_sender(jt)) {
 79 #if COMPILER2_OR_JVMCI
 80       // C2 and JVMCI use ebp as a general register see if NULL fp helps
 81       frame ret_frame2(ret_frame.sp(), NULL, ret_frame.pc());
 82       if (!ret_frame2.safe_for_sender(jt)) {
 83         // nothing else to try if the frame isn't good
 84         return false;
 85       }
 86       ret_frame = ret_frame2;
 87 #else
 88       // nothing else to try if the frame isn't good
 89       return false;
 90 #endif // COMPILER2_OR_JVMCI
 91     }
 92     *fr_addr = ret_frame;
 93     return true;
 94   }
 95 
 96   // nothing else to try
 97   return false;
 98 }
 99 
100 void JavaThread::cache_global_variables() { }