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   assert(Thread::current() == this, "caller must be current thread");
  41   return pd_get_top_frame(fr_addr, ucontext, isInJava);
  42 }
  43 
  44 bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr,
  45   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,
  50   void* ucontext, bool isInJava) {
  51   assert(this->is_Java_thread(), "must be JavaThread");
  52   JavaThread* jt = (JavaThread *)this;
  53 
  54   // There is small window where last_Java_frame is not walkable or safe
  55   if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
  56     *fr_addr = jt->pd_last_frame();
  57     return true;
  58   }
  59 
  60   ucontext_t* uc = (ucontext_t*) ucontext;
  61 
  62   // We always want to use the initial frame we create from the ucontext as
  63   // it certainly signals where we currently are. However that frame may not
  64   // be safe for calling sender. In that case if we have a last_Java_frame
  65   // then the forte walker will switch to that frame as the virtual sender
  66   // for the frame we create here which is not sender safe.
  67 
  68   intptr_t* ret_fp;
  69   intptr_t* ret_sp;
  70   ExtendedPC addr = os::Solaris::fetch_frame_from_ucontext(this, uc, &ret_sp, &ret_fp);
  71 
  72   // Something would really have to be screwed up to get a NULL pc
  73 
  74   if (addr.pc() == NULL) {
  75     assert(false, "NULL pc from signal handler!");
  76     return false;
  77   }
  78 
  79   if (MetaspaceShared::is_in_trampoline_frame(addr.pc())) {
  80     // In the middle of a trampoline call. Bail out for safety.
  81     // This happens rarely so shouldn't affect profiling.
  82     return false;
  83   }
  84 
  85   // If sp and fp are nonsense just leave them out
  86 
  87   if (!jt->is_in_full_stack((address)ret_sp)) {
  88     ret_sp = NULL;
  89     ret_fp = NULL;
  90   } else {
  91     // sp is reasonable is fp reasonable?
  92     if (!jt->is_in_stack_range_incl((address)ret_fp, (address)ret_sp)) {
  93       ret_fp = NULL;
  94     }
  95   }
  96 
  97   frame ret_frame(ret_sp, ret_fp, addr.pc());
  98 
  99   *fr_addr = ret_frame;
 100   return true;
 101 
 102 }
 103 
 104 void JavaThread::cache_global_variables() { }