1 /*
   2  * Copyright (c) 2003, 2008, 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_sparc.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,
  32                                                      bool isInJava) {
  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 (!isInJava) {
  39     // make_walkable flushes register windows and grabs last_Java_pc
  40     // which can not be done if the ucontext sp matches last_Java_sp
  41     // stack walking utilities assume last_Java_pc set if marked flushed
  42     jt->frame_anchor()->make_walkable(jt);
  43   }
  44 
  45   // If we have a walkable last_Java_frame, then we should use it
  46   // even if isInJava == true. It should be more reliable than
  47   // ucontext info.
  48   if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
  49     *fr_addr = jt->pd_last_frame();
  50     return true;
  51   }
  52 
  53   ucontext_t* uc = (ucontext_t*) ucontext;
  54 
  55   // At this point, we don't have a walkable last_Java_frame, so
  56   // we try to glean some information out of the ucontext.
  57   intptr_t* ret_sp;
  58   ExtendedPC addr =
  59     os::fetch_frame_from_context(uc, &ret_sp,
  60                                  NULL /* ret_fp only used on X86 */);
  61   if (addr.pc() == NULL || ret_sp == NULL) {
  62     // ucontext wasn't useful
  63     return false;
  64   }
  65 
  66   // we were running Java code when SIGPROF came in
  67   if (isInJava) {
  68     // If we have a last_Java_sp, then the SIGPROF signal caught us
  69     // right when we were transitioning from _thread_in_Java to a new
  70     // JavaThreadState. We use last_Java_sp instead of the sp from
  71     // the ucontext since it should be more reliable.
  72     if (jt->has_last_Java_frame()) {
  73       ret_sp = jt->last_Java_sp();
  74     }
  75     // Implied else: we don't have a last_Java_sp so we use what we
  76     // got from the ucontext.
  77 
  78     frame ret_frame(ret_sp, frame::unpatchable, addr.pc());
  79     if (!ret_frame.safe_for_sender(jt)) {
  80       // nothing else to try if the frame isn't good
  81       return false;
  82     }
  83     *fr_addr = ret_frame;
  84     return true;
  85   }
  86 
  87   // At this point, we know we weren't running Java code. We might
  88   // have a last_Java_sp, but we don't have a walkable frame.
  89   // However, we might still be able to construct something useful
  90   // if the thread was running native code.
  91   if (jt->has_last_Java_frame()) {
  92     assert(!jt->frame_anchor()->walkable(), "case covered above");
  93 
  94     if (jt->thread_state() == _thread_in_native) {
  95       frame ret_frame(jt->last_Java_sp(), frame::unpatchable, addr.pc());
  96       if (!ret_frame.safe_for_sender(jt)) {
  97         // nothing else to try if the frame isn't good
  98         return false;
  99       }
 100       *fr_addr = ret_frame;
 101       return true;
 102     }
 103   }
 104 
 105   // nothing else to try
 106   return false;
 107 }
 108 
 109 void JavaThread::cache_global_variables() { }
 110