# HG changeset patch
# User morris
# Date 1364044927 25200
# Node ID 3c786355ffb4d327ef776fb2d1ccc8f265683855
# Parent  360ce06580b89681507ed86d7a67778b8fde1af0
8009026: [parfait] Null pointer deference in hotspot/src/share/vm/code/nmethod.cpp
Summary: add guarantee() to nmethod constructor and checks to ensure CodeCache has space before allocation
Reviewed-by: kvn

diff -r 360ce06580b8 -r 3c786355ffb4 src/share/vm/code/codeCache.hpp
--- a/src/share/vm/code/codeCache.hpp	Fri Mar 22 13:35:31 2013 -0400
+++ b/src/share/vm/code/codeCache.hpp	Sat Mar 23 06:22:07 2013 -0700
@@ -156,6 +156,11 @@
   static address  low_bound()                    { return (address) _heap->low_boundary(); }
   static address  high_bound()                   { return (address) _heap->high_boundary(); }
 
+  static bool has_space(int size) {
+    // Always leave some room in the CodeCache for I2C/C2I adapters
+    return largest_free_block() > (CodeCacheMinimumFreeSpace + size);
+  }
+
   // Profiling
   static address first_address();                // first address used for CodeBlobs
   static address last_address();                 // last  address used for CodeBlobs
diff -r 360ce06580b8 -r 3c786355ffb4 src/share/vm/code/nmethod.cpp
--- a/src/share/vm/code/nmethod.cpp	Fri Mar 22 13:35:31 2013 -0400
+++ b/src/share/vm/code/nmethod.cpp	Sat Mar 23 06:22:07 2013 -0700
@@ -486,7 +486,6 @@
 #endif // def HAVE_DTRACE_H
 }
 
-
 nmethod* nmethod::new_native_nmethod(methodHandle method,
   int compile_id,
   CodeBuffer *code_buffer,
@@ -502,17 +501,19 @@
   {
     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
     int native_nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
-    CodeOffsets offsets;
-    offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
-    offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
-    nm = new (native_nmethod_size)
-      nmethod(method(), native_nmethod_size, compile_id, &offsets,
-              code_buffer, frame_size,
-              basic_lock_owner_sp_offset, basic_lock_sp_offset,
-              oop_maps);
-    NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_native_nmethod(nm));
-    if (PrintAssembly && nm != NULL)
-      Disassembler::decode(nm);
+    if (CodeCache::has_space(native_nmethod_size)) {
+      CodeOffsets offsets;
+      offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
+      offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
+      nm = new (native_nmethod_size) nmethod(method(), native_nmethod_size,
+                                             compile_id, &offsets,
+                                             code_buffer, frame_size,
+                                             basic_lock_owner_sp_offset,
+                                             basic_lock_sp_offset, oop_maps);
+      NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_native_nmethod(nm));
+      if (PrintAssembly && nm != NULL)
+        Disassembler::decode(nm);
+    }
   }
   // verify nmethod
   debug_only(if (nm) nm->verify();) // might block
@@ -537,16 +538,19 @@
   {
     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
     int nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
-    CodeOffsets offsets;
-    offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
-    offsets.set_value(CodeOffsets::Dtrace_trap, trap_offset);
-    offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
+    if (CodeCache::has_space(nmethod_size)) {
+      CodeOffsets offsets;
+      offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
+      offsets.set_value(CodeOffsets::Dtrace_trap, trap_offset);
+      offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
 
-    nm = new (nmethod_size) nmethod(method(), nmethod_size, &offsets, code_buffer, frame_size);
+      nm = new (nmethod_size) nmethod(method(), nmethod_size,
+                                      &offsets, code_buffer, frame_size);
 
-    NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
-    if (PrintAssembly && nm != NULL)
-      Disassembler::decode(nm);
+      NOT_PRODUCT(if (nm != NULL)  nmethod_stats.note_nmethod(nm));
+      if (PrintAssembly && nm != NULL)
+        Disassembler::decode(nm);
+    }
   }
   // verify nmethod
   debug_only(if (nm) nm->verify();) // might block
@@ -587,7 +591,8 @@
       + round_to(handler_table->size_in_bytes(), oopSize)
       + round_to(nul_chk_table->size_in_bytes(), oopSize)
       + round_to(debug_info->data_size()       , oopSize);
-    nm = new (nmethod_size)
+    if (CodeCache::has_space(nmethod_size)) {
+      nm = new (nmethod_size)
       nmethod(method(), nmethod_size, compile_id, entry_bci, offsets,
               orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
               oop_maps,
@@ -595,6 +600,7 @@
               nul_chk_table,
               compiler,
               comp_level);
+    }
     if (nm != NULL) {
       // To make dependency checking during class loading fast, record
       // the nmethod dependencies in the classes it is dependent on.
@@ -793,9 +799,9 @@
 #endif // def HAVE_DTRACE_H
 
 void* nmethod::operator new(size_t size, int nmethod_size) {
-  // Always leave some room in the CodeCache for I2C/C2I adapters
-  if (CodeCache::largest_free_block() < CodeCacheMinimumFreeSpace) return NULL;
-  return CodeCache::allocate(nmethod_size);
+  void*  alloc = CodeCache::allocate(nmethod_size);
+  guarantee(alloc != NULL, "CodeCache should have enough space");
+  return alloc;
 }