hotspot/src/os_cpu/solaris_x86/vm/thread_solaris_x86.cpp

rev 611 : Merge

@@ -1,10 +1,7 @@
-#ifdef USE_PRAGMA_IDENT_SRC
-#pragma ident "@(#)thread_solaris_x86.cpp       1.15 07/09/17 10:00:20 JVM"
-#endif
 /*
- * Copyright 2003-2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2003-2008 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.

@@ -33,51 +30,55 @@
 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
   void* ucontext, bool isInJava) {
 
   assert(Thread::current() == this, "caller must be current thread");
   assert(this->is_Java_thread(), "must be JavaThread");
-
   JavaThread* jt = (JavaThread *)this;
 
-  // If we have a last_Java_frame, then we should use it even if
-  // isInJava == true.  It should be more reliable than ucontext info.
+  // last_Java_frame is always walkable and safe use it if we have it
+
   if (jt->has_last_Java_frame()) {
     *fr_addr = jt->pd_last_frame();
     return true;
   }
 
-  // At this point, we don't have a last_Java_frame, so
-  // we try to glean some information out of the ucontext
-  // if we were running Java code when SIGPROF came in.
-  if (isInJava) {
     ucontext_t* uc = (ucontext_t*) ucontext;
 
+  // We always want to use the initial frame we create from the ucontext as
+  // it certainly signals where we currently are. However that frame may not
+  // be safe for calling sender. In that case if we have a last_Java_frame
+  // then the forte walker will switch to that frame as the virtual sender
+  // for the frame we create here which is not sender safe.
+
     intptr_t* ret_fp;
     intptr_t* ret_sp;
-    ExtendedPC addr = os::Solaris::fetch_frame_from_ucontext(this, uc,
-      &ret_sp, &ret_fp);
-    if (addr.pc() == NULL || ret_sp == NULL ) {
-      // ucontext wasn't useful
+  ExtendedPC addr = os::Solaris::fetch_frame_from_ucontext(this, uc, &ret_sp, &ret_fp);
+
+  // Something would really have to be screwed up to get a NULL pc
+
+  if (addr.pc() == NULL ) {
+    assert(false, "NULL pc from signal handler!");
       return false;
+
     }
 
-    frame ret_frame(ret_sp, ret_fp, addr.pc());
-    if (!ret_frame.safe_for_sender(jt)) {
-#ifdef COMPILER2
-      frame ret_frame2(ret_sp, NULL, addr.pc());
-      if (!ret_frame2.safe_for_sender(jt)) {
-        // nothing else to try if the frame isn't good
-        return false;
+  // If sp and fp are nonsense just leave them out
+
+  if ((address)ret_sp >= jt->stack_base() ||
+      (address)ret_sp < jt->stack_base() - jt->stack_size() ) {
+
+      ret_sp = NULL;
+      ret_fp = NULL;
+  } else {
+
+    // sp is reasonable is fp reasonable?
+    if ( (address)ret_fp >= jt->stack_base() || ret_fp < ret_sp) {
+      ret_fp = NULL;
       }
-      ret_frame = ret_frame2;
-#else
-      // nothing else to try if the frame isn't good
-      return false;
-#endif /* COMPILER2 */
     }
+
+  frame ret_frame(ret_sp, ret_fp, addr.pc());
+
     *fr_addr = ret_frame;
     return true;
-  }
 
-  // nothing else to try
-  return false;
 }