1 /*
   2  * Copyright (c) 2003, 2005, 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 "incls/_precompiled.incl"
  26 #include "incls/_thread_linux_x86.cpp.incl"
  27 
  28 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is
  29 // currently interrupted by SIGPROF
  30 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
  31   void* ucontext, bool isInJava) {
  32 
  33   assert(Thread::current() == this, "caller must be current thread");
  34   assert(this->is_Java_thread(), "must be JavaThread");
  35 
  36   JavaThread* jt = (JavaThread *)this;
  37 
  38   // If we have a last_Java_frame, then we should use it even if
  39   // isInJava == true.  It should be more reliable than ucontext info.
  40   if (jt->has_last_Java_frame()) {
  41     *fr_addr = jt->pd_last_frame();
  42     return true;
  43   }
  44 
  45   // At this point, we don't have a last_Java_frame, so
  46   // we try to glean some information out of the ucontext
  47   // if we were running Java code when SIGPROF came in.
  48   if (isInJava) {
  49     ucontext_t* uc = (ucontext_t*) ucontext;
  50 
  51     intptr_t* ret_fp;
  52     intptr_t* ret_sp;
  53     ExtendedPC addr = os::Linux::fetch_frame_from_ucontext(this, uc,
  54       &ret_sp, &ret_fp);
  55     if (addr.pc() == NULL || ret_sp == NULL ) {
  56       // ucontext wasn't useful
  57       return false;
  58     }
  59 
  60     frame ret_frame(ret_sp, ret_fp, addr.pc());
  61     if (!ret_frame.safe_for_sender(jt)) {
  62 #ifdef COMPILER2
  63       // C2 uses ebp as a general register see if NULL fp helps
  64       frame ret_frame2(ret_sp, NULL, addr.pc());
  65       if (!ret_frame2.safe_for_sender(jt)) {
  66         // nothing else to try if the frame isn't good
  67         return false;
  68       }
  69       ret_frame = ret_frame2;
  70 #else
  71       // nothing else to try if the frame isn't good
  72       return false;
  73 #endif /* COMPILER2 */
  74     }
  75     *fr_addr = ret_frame;
  76     return true;
  77   }
  78 
  79   // nothing else to try
  80   return false;
  81 }
  82 
  83 void JavaThread::cache_global_variables() { }
  84