1 /*

     2  * Copyright 2003-2004 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 #include "incls/_precompiled.incl"

    26 #include "incls/_thread_solaris_sparc.cpp.incl"

    27 

    28 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is

    29 // currently interrupted by SIGPROF

    30 //

    31 // NOTE: On Solaris, register windows are flushed in the signal handler

    32 // except for possibly the top frame.

    33 //

    34 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,

    35   void* ucontext, bool isInJava) {

    36 

    37   assert(Thread::current() == this, "caller must be current thread");

    38   assert(this->is_Java_thread(), "must be JavaThread");

    39 

    40   JavaThread* jt = (JavaThread *)this;

    41 

    42   if (!isInJava) {

    43     // make_walkable flushes register windows and grabs last_Java_pc

    44     // which can not be done if the ucontext sp matches last_Java_sp

    45     // stack walking utilities assume last_Java_pc set if marked flushed

    46     jt->frame_anchor()->make_walkable(jt);

    47   }

    48 

    49   // If we have a walkable last_Java_frame, then we should use it

    50   // even if isInJava == true. It should be more reliable than

    51   // ucontext info.

    52   if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {

    53 #if 0

    54     // This sanity check may not be needed with the new frame

    55     // walking code. Remove it for now.

    56     if (!jt->frame_anchor()->post_Java_state_is_pc()

    57     && frame::next_younger_sp_or_null(last_Java_sp(),

    58     jt->frame_anchor()->post_Java_sp()) == NULL) {

    59       // the anchor contains an SP, but the frame is not walkable

    60       // because post_Java_sp isn't valid relative to last_Java_sp

    61       return false;

    62     }

    63 #endif

    64     *fr_addr = jt->pd_last_frame();

    65     return true;

    66   }

    67 

    68   ucontext_t* uc = (ucontext_t*) ucontext;

    69 

    70   // At this point, we don't have a walkable last_Java_frame, so

    71   // we try to glean some information out of the ucontext.

    72   intptr_t* ret_sp;

    73   ExtendedPC addr = os::Solaris::fetch_frame_from_ucontext(this, uc,

    74     &ret_sp, NULL /* ret_fp only used on Solaris X86 */);

    75   if (addr.pc() == NULL || ret_sp == NULL) {

    76     // ucontext wasn't useful

    77     return false;

    78   }

    79 

    80   // we were running Java code when SIGPROF came in

    81   if (isInJava) {

    82     // If we have a last_Java_sp, then the SIGPROF signal caught us

    83     // right when we were transitioning from _thread_in_Java to a new

    84     // JavaThreadState. We use last_Java_sp instead of the sp from

    85     // the ucontext since it should be more reliable.

    86     if (jt->has_last_Java_frame()) {

    87       ret_sp = jt->last_Java_sp();

    88     }

    89     // Implied else: we don't have a last_Java_sp so we use what we

    90     // got from the ucontext.

    91 

    92     frame ret_frame(ret_sp, frame::unpatchable, addr.pc());

    93     if (!ret_frame.safe_for_sender(jt)) {

    94       // nothing else to try if the frame isn't good

    95       return false;

    96     }

    97     *fr_addr = ret_frame;

    98     return true;

    99   }

   100 

   101   // At this point, we know we weren't running Java code. We might

   102   // have a last_Java_sp, but we don't have a walkable frame.

   103   // However, we might still be able to construct something useful

   104   // if the thread was running native code.

   105   if (jt->has_last_Java_frame()) {

   106     assert(!jt->frame_anchor()->walkable(), "case covered above");

   107 

   108     if (jt->thread_state() == _thread_in_native) {

   109       frame ret_frame(jt->last_Java_sp(), frame::unpatchable, addr.pc());

   110       if (!ret_frame.safe_for_sender(jt)) {

   111         // nothing else to try if the frame isn't good

   112         return false;

   113       }

   114       *fr_addr = ret_frame;

   115       return true;

   116     }

   117   }

   118 

   119   // nothing else to try

   120   return false;

   121 }