Add basic checks for redefinition.
This adds some checks for redefined classes. Currently it checks that
the transformed class has the same name, interfaces, and access flags.
Other checks will be added in the future.
Test: mma -j40 test-art-host
Change-Id: Iaa94e9e8688db1985d15f27acf3ddb53908a1c8b
diff --git a/runtime/openjdkjvmti/OpenjdkJvmTi.cc b/runtime/openjdkjvmti/OpenjdkJvmTi.cc
index fa55e85..28cfd64 100644
--- a/runtime/openjdkjvmti/OpenjdkJvmTi.cc
+++ b/runtime/openjdkjvmti/OpenjdkJvmTi.cc
@@ -1190,7 +1190,7 @@
reinterpret_cast<uint8_t*>(dex_file),
&error);
if (ret != OK) {
- LOG(ERROR) << "FAILURE TO REDEFINE " << error;
+ LOG(WARNING) << "FAILURE TO REDEFINE " << error;
}
return ret;
}
diff --git a/runtime/openjdkjvmti/ti_redefine.cc b/runtime/openjdkjvmti/ti_redefine.cc
index 926819d..6b0e9c8 100644
--- a/runtime/openjdkjvmti/ti_redefine.cc
+++ b/runtime/openjdkjvmti/ti_redefine.cc
@@ -37,6 +37,8 @@
#include "art_jvmti.h"
#include "base/logging.h"
+#include "dex_file.h"
+#include "dex_file_types.h"
#include "events-inl.h"
#include "gc/allocation_listener.h"
#include "gc/heap.h"
@@ -542,6 +544,118 @@
i->ReJitEverything("libOpenJkdJvmti - Class Redefinition");
}
+bool Redefiner::CheckClass() {
+ // TODO Might just want to put it in a ObjPtr and NoSuspend assert.
+ art::StackHandleScope<1> hs(self_);
+ // Easy check that only 1 class def is present.
+ if (dex_file_->NumClassDefs() != 1) {
+ RecordFailure(ERR(ILLEGAL_ARGUMENT),
+ StringPrintf("Expected 1 class def in dex file but found %d",
+ dex_file_->NumClassDefs()));
+ return false;
+ }
+ // Get the ClassDef from the new DexFile.
+ // Since the dex file has only a single class def the index is always 0.
+ const art::DexFile::ClassDef& def = dex_file_->GetClassDef(0);
+ // Get the class as it is now.
+ art::Handle<art::mirror::Class> current_class(hs.NewHandle(GetMirrorClass()));
+
+ // Check the access flags didn't change.
+ if (def.GetJavaAccessFlags() != (current_class->GetAccessFlags() & art::kAccValidClassFlags)) {
+ RecordFailure(ERR(UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED),
+ "Cannot change modifiers of class by redefinition");
+ return false;
+ }
+
+ // Check class name.
+ // These should have been checked by the dexfile verifier on load.
+ DCHECK_NE(def.class_idx_, art::dex::TypeIndex::Invalid()) << "Invalid type index";
+ const char* descriptor = dex_file_->StringByTypeIdx(def.class_idx_);
+ DCHECK(descriptor != nullptr) << "Invalid dex file structure!";
+ if (!current_class->DescriptorEquals(descriptor)) {
+ std::string storage;
+ RecordFailure(ERR(NAMES_DONT_MATCH),
+ StringPrintf("expected file to contain class called '%s' but found '%s'!",
+ current_class->GetDescriptor(&storage),
+ descriptor));
+ return false;
+ }
+ if (current_class->IsObjectClass()) {
+ if (def.superclass_idx_ != art::dex::TypeIndex::Invalid()) {
+ RecordFailure(ERR(UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED), "Superclass added!");
+ return false;
+ }
+ } else {
+ const char* super_descriptor = dex_file_->StringByTypeIdx(def.superclass_idx_);
+ DCHECK(descriptor != nullptr) << "Invalid dex file structure!";
+ if (!current_class->GetSuperClass()->DescriptorEquals(super_descriptor)) {
+ RecordFailure(ERR(UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED), "Superclass changed");
+ return false;
+ }
+ }
+ const art::DexFile::TypeList* interfaces = dex_file_->GetInterfacesList(def);
+ if (interfaces == nullptr) {
+ if (current_class->NumDirectInterfaces() != 0) {
+ RecordFailure(ERR(UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED), "Interfaces added");
+ return false;
+ }
+ } else {
+ DCHECK(!current_class->IsProxyClass());
+ const art::DexFile::TypeList* current_interfaces = current_class->GetInterfaceTypeList();
+ if (current_interfaces == nullptr || current_interfaces->Size() != interfaces->Size()) {
+ RecordFailure(ERR(UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED), "Interfaces added or removed");
+ return false;
+ }
+ // The order of interfaces is (barely) meaningful so we error if it changes.
+ const art::DexFile& orig_dex_file = current_class->GetDexFile();
+ for (uint32_t i = 0; i < interfaces->Size(); i++) {
+ if (strcmp(
+ dex_file_->StringByTypeIdx(interfaces->GetTypeItem(i).type_idx_),
+ orig_dex_file.StringByTypeIdx(current_interfaces->GetTypeItem(i).type_idx_)) != 0) {
+ RecordFailure(ERR(UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED),
+ "Interfaces changed or re-ordered");
+ return false;
+ }
+ }
+ }
+ LOG(WARNING) << "No verification is done on annotations of redefined classes.";
+
+ return true;
+}
+
+// TODO Move this to use IsRedefinable when that function is made.
+bool Redefiner::CheckRedefinable() {
+ art::ObjPtr<art::mirror::Class> klass(GetMirrorClass());
+ if (klass->IsPrimitive()) {
+ RecordFailure(ERR(UNMODIFIABLE_CLASS),
+ "Modification of primitive classes is not supported");
+ return false;
+ } else if (klass->IsInterface()) {
+ RecordFailure(ERR(UNMODIFIABLE_CLASS),
+ "Modification of Interface classes is currently not supported");
+ return false;
+ } else if (klass->IsArrayClass()) {
+ RecordFailure(ERR(UNMODIFIABLE_CLASS),
+ "Modification of Array classes is not supported");
+ return false;
+ } else if (klass->IsProxyClass()) {
+ RecordFailure(ERR(UNMODIFIABLE_CLASS),
+ "Modification of proxy classes is not supported");
+ return false;
+ }
+
+ // TODO We should check if the class has non-obsoletable methods on the stack
+ LOG(WARNING) << "presence of non-obsoletable methods on stacks is not currently checked";
+ return true;
+}
+
+bool Redefiner::CheckRedefinitionIsValid() {
+ return CheckRedefinable() &&
+ CheckClass() &&
+ CheckSameFields() &&
+ CheckSameMethods();
+}
+
jvmtiError Redefiner::Run() {
art::StackHandleScope<5> hs(self_);
// TODO We might want to have a global lock (or one based on the class being redefined at least)
@@ -552,7 +666,7 @@
// doing a try loop. The other allocations we need to ensure that nothing has changed in the time
// between allocating them and pausing all threads before we can update them so we need to do a
// try loop.
- if (!EnsureRedefinitionIsValid() || !EnsureClassAllocationsFinished()) {
+ if (!CheckRedefinitionIsValid() || !EnsureClassAllocationsFinished()) {
return result_;
}
art::MutableHandle<art::mirror::ClassLoader> source_class_loader(
diff --git a/runtime/openjdkjvmti/ti_redefine.h b/runtime/openjdkjvmti/ti_redefine.h
index 9d23ce4..d6bccb4 100644
--- a/runtime/openjdkjvmti/ti_redefine.h
+++ b/runtime/openjdkjvmti/ti_redefine.h
@@ -152,14 +152,29 @@
void RecordFailure(jvmtiError result, const std::string& error_msg);
- // TODO Actually write this.
// This will check that no constraints are violated (more than 1 class in dex file, any changes in
// number/declaration of methods & fields, changes in access flags, etc.)
- bool EnsureRedefinitionIsValid() {
- LOG(WARNING) << "Redefinition is not checked for validity currently";
+ bool CheckRedefinitionIsValid() REQUIRES_SHARED(art::Locks::mutator_lock_);
+
+ // Checks that the class can even be redefined.
+ bool CheckRedefinable() REQUIRES_SHARED(art::Locks::mutator_lock_);
+
+ // Checks that the dex file does not add/remove methods.
+ bool CheckSameMethods() REQUIRES_SHARED(art::Locks::mutator_lock_) {
+ LOG(WARNING) << "methods are not checked for modification currently";
return true;
}
+ // Checks that the dex file does not modify fields
+ bool CheckSameFields() REQUIRES_SHARED(art::Locks::mutator_lock_) {
+ LOG(WARNING) << "Fields are not checked for modification currently";
+ return true;
+ }
+
+ // Checks that the dex file contains only the single expected class and that the top-level class
+ // data has not been modified in an incompatible manner.
+ bool CheckClass() REQUIRES_SHARED(art::Locks::mutator_lock_);
+
bool UpdateJavaDexFile(art::ObjPtr<art::mirror::Object> java_dex_file,
art::ObjPtr<art::mirror::LongArray> new_cookie,
/*out*/art::ObjPtr<art::mirror::LongArray>* original_cookie)