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7121073: secondary_super_cache memory slice has incorrect bounds in flatten_alias_type

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Reviewed-by: kvn
This commit is contained in:
Tom Rodriguez 2011-12-19 14:16:23 -08:00
parent b7f5d60a7e
commit 2928feab6a
1 changed files with 9 additions and 8 deletions
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17
hotspot/src/share/vm/opto/compile.cpp
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@ -1282,12 +1282,11 @@ const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
if( tk ) { if( tk ) {
// If we are referencing a field within a Klass, we need // If we are referencing a field within a Klass, we need
// to assume the worst case of an Object. Both exact and // to assume the worst case of an Object. Both exact and
// inexact types must flatten to the same alias class. // inexact types must flatten to the same alias class so
// Since the flattened result for a klass is defined to be // use NotNull as the PTR.
// precisely java.lang.Object, use a constant ptr.
if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) { if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
tj = tk = TypeKlassPtr::make(TypePtr::Constant, tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
TypeKlassPtr::OBJECT->klass(), TypeKlassPtr::OBJECT->klass(),
offset); offset);
} }
@ -1307,10 +1306,12 @@ const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
// these 2 disparate memories into the same alias class. Since the // these 2 disparate memories into the same alias class. Since the
// primary supertype array is read-only, there's no chance of confusion // primary supertype array is read-only, there's no chance of confusion
// where we bypass an array load and an array store. // where we bypass an array load and an array store.
uint off2 = offset - Klass::primary_supers_offset_in_bytes(); int primary_supers_offset = sizeof(klassOopDesc) + Klass::primary_supers_offset_in_bytes();
if( offset == Type::OffsetBot || if (offset == Type::OffsetBot ||
off2 < Klass::primary_super_limit()*wordSize ) { (offset >= primary_supers_offset &&
offset = sizeof(oopDesc) +Klass::secondary_super_cache_offset_in_bytes(); offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
offset == (int)(sizeof(klassOopDesc) + Klass::secondary_super_cache_offset_in_bytes())) {
offset = sizeof(klassOopDesc) + Klass::secondary_super_cache_offset_in_bytes();
tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset ); tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
} }
} }