1 /*
   2  * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  *
  24  */
  25 
  26 #include "precompiled.hpp"
  27 #include "memory/metaspaceShared.hpp"
  28 #include "runtime/frame.inline.hpp"
  29 #include "runtime/thread.inline.hpp"
  30 
  31 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is
  32 // currently interrupted by SIGPROF
  33 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
  34   void* ucontext, bool isInJava) {
  35 
  36   assert(Thread::current() == this, "caller must be current thread");
  37   return pd_get_top_frame(fr_addr, ucontext, isInJava);
  38 }
  39 
  40 bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext, bool isInJava) {
  41   return pd_get_top_frame(fr_addr, ucontext, isInJava);
  42 }
  43 
  44 bool JavaThread::pd_get_top_frame(frame* fr_addr, void* ucontext, bool isInJava) {
  45   assert(this->is_Java_thread(), "must be JavaThread");
  46   JavaThread* jt = (JavaThread *)this;
  47 
  48   // If we have a last_Java_frame, then we should use it even if
  49   // isInJava == true.  It should be more reliable than ucontext info.
  50   if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
  51     *fr_addr = jt->pd_last_frame();
  52     return true;
  53   }
  54 
  55   // At this point, we don't have a last_Java_frame, so
  56   // we try to glean some information out of the ucontext
  57   // if we were running Java code when SIGPROF came in.
  58   if (isInJava) {
  59     ucontext_t* uc = (ucontext_t*) ucontext;
  60 
  61     intptr_t* ret_fp;
  62     intptr_t* ret_sp;
  63     ExtendedPC addr = os::Linux::fetch_frame_from_ucontext(this, uc,
  64       &ret_sp, &ret_fp);
  65     if (addr.pc() == NULL || ret_sp == NULL ) {
  66       // ucontext wasn't useful
  67       return false;
  68     }
  69 
  70     if (MetaspaceShared::is_in_trampoline_frame(addr.pc())) {
  71       // In the middle of a trampoline call. Bail out for safety.
  72       // This happens rarely so shouldn't affect profiling.
  73       return false;
  74     }
  75 
  76     frame ret_frame(ret_sp, ret_fp, addr.pc());
  77     if (!ret_frame.safe_for_sender(jt)) {
  78 #ifdef COMPILER2
  79       frame ret_frame2(ret_sp, NULL, addr.pc());
  80       if (!ret_frame2.safe_for_sender(jt)) {
  81         // nothing else to try if the frame isn't good
  82         return false;
  83       }
  84       ret_frame = ret_frame2;
  85 #else
  86       // nothing else to try if the frame isn't good
  87       return false;
  88 #endif /* COMPILER2 */
  89     }
  90     *fr_addr = ret_frame;
  91     return true;
  92   }
  93 
  94   // nothing else to try
  95   return false;
  96 }
  97 
  98 void JavaThread::cache_global_variables() { }
  99