From e8a91c7692aaf9c07b78adec523ec85defe87a46 Mon Sep 17 00:00:00 2001
From: roland <unknown>
Date: Mon, 26 Aug 2013 16:12:20 +0200
Subject: [PATCH] 8016277: Crash in nmethod::is_compiled_by_c1() on x86
 Summary: Method pointer for zombie methods may be invalid Reviewed-by: kvn,
 coleenp

---
 src/share/vm/code/nmethod.cpp | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/share/vm/code/nmethod.cpp b/src/share/vm/code/nmethod.cpp
index 9412feff7..9cc45d745 100644
--- a/src/share/vm/code/nmethod.cpp
+++ b/src/share/vm/code/nmethod.cpp
@@ -93,18 +93,21 @@ HS_DTRACE_PROBE_DECL6(hotspot, compiled__method__unload,
 #endif
 
 bool nmethod::is_compiled_by_c1() const {
-  if (compiler() == NULL || method() == NULL)  return false;  // can happen during debug printing
-  if (is_native_method()) return false;
+  if (compiler() == NULL) {
+    return false;
+  }
   return compiler()->is_c1();
 }
 bool nmethod::is_compiled_by_c2() const {
-  if (compiler() == NULL || method() == NULL)  return false;  // can happen during debug printing
-  if (is_native_method()) return false;
+  if (compiler() == NULL) {
+    return false;
+  }
   return compiler()->is_c2();
 }
 bool nmethod::is_compiled_by_shark() const {
-  if (is_native_method()) return false;
-  assert(compiler() != NULL, "must be");
+  if (compiler() == NULL) {
+    return false;
+  }
   return compiler()->is_shark();
 }
 
@@ -1401,6 +1404,9 @@ bool nmethod::make_not_entrant_or_zombie(unsigned int state) {
     // nmethods aren't scanned for GC.
     _oops_are_stale = true;
 #endif
+     // the Method may be reclaimed by class unloading now that the
+     // nmethod is in zombie state
+    set_method(NULL);
   } else {
     assert(state == not_entrant, "other cases may need to be handled differently");
   }
-- 
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