src/os_cpu/linux_ppc/vm/thread_linux_ppc.cpp

@@ -22,15 +22,66 @@
  * questions.
  *
  */
 
 #include "precompiled.hpp"
-#include "runtime/frame.hpp"
+#include "runtime/frame.inline.hpp"
 #include "runtime/thread.hpp"
 
+bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext, bool isInJava) {
+  assert(this->is_Java_thread(), "must be JavaThread");
+
+  // If we have a last_Java_frame, then we should use it even if
+  // isInJava == true.  It should be more reliable than ucontext info.
+  if (has_last_Java_frame() && frame_anchor()->walkable()) {
+    *fr_addr = 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;
+    frame ret_frame((intptr_t*)uc->uc_mcontext.regs->gpr[1/*REG_SP*/],
+                     (address)uc->uc_mcontext.regs->nip);
+
+    if (ret_frame.pc() == NULL) {
+      // ucontext wasn't useful
+      return false;
+    }
+
+    if (ret_frame.is_interpreted_frame()) {
+       frame::ijava_state* istate = ret_frame.get_ijava_state();
+       if (!((Method*)(istate->method))->is_metaspace_object()) {
+         return false;
+       }
+       uint64_t reg_bcp = uc->uc_mcontext.regs->gpr[14/*R14_bcp*/];
+       uint64_t istate_bcp = istate->bcp;
+       uint64_t code_start = (uint64_t)(((Method*)(istate->method))->code_base());
+       uint64_t code_end = (uint64_t)(((Method*)istate->method)->code_base() + ((Method*)istate->method)->code_size());
+       if (istate_bcp >= code_start && istate_bcp < code_end) {
+         // we have a valid bcp, don't touch it, do nothing
+       } else if (reg_bcp >= code_start && reg_bcp < code_end) {
+         istate->bcp = reg_bcp;
+      } else {
+         return false;
+       }
+    }
+    if (!ret_frame.safe_for_sender(this)) {
+      // nothing else to try if the frame isn't good
+      return false;
+    }
+    *fr_addr = ret_frame;
+    return true;
+  }
+  // nothing else to try
+  return false;
+}
+
 // Forte Analyzer AsyncGetCallTrace profiling support is not implemented on Linux/PPC.
 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr, void* ucontext, bool isInJava) {
-  Unimplemented();
-  return false;
+  assert(this->is_Java_thread(), "must be JavaThread");
+  return pd_get_top_frame_for_profiling(fr_addr, ucontext, isInJava);
 }
 
 void JavaThread::cache_global_variables() { }