Runtime can now be set to require relocation

Add a pair of runtime flags -Xrelocate and -Xnorelocate that can force
the runtime to require that all files that are run are relocated, to
prevent attacks based on the known art base address.

Add support for running patchoat on oat files compiled without an image.

Change run-test to have new --prebuild and --relocate flags.

Bug: 15358152

Change-Id: I91166c62dd1ab80e5cbcb7883a2cd0d56afca32d

1 files changed, 132 insertions, 0 deletions

diff --git a/compiler/elf_patcher.h b/compiler/elf_patcher.h
new file mode 100644
index 0000000000..0a9f0a013e
--- /dev/null
+++ b/compiler/elf_patcher.h
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_ELF_PATCHER_H_
+#define ART_COMPILER_ELF_PATCHER_H_
+
+#include "base/mutex.h"
+#include "driver/compiler_driver.h"
+#include "elf_file.h"
+#include "mirror/art_method.h"
+#include "mirror/class.h"
+#include "mirror/object.h"
+#include "oat_file.h"
+#include "oat.h"
+#include "os.h"
+
+namespace art {
+
+class ElfPatcher {
+ public:
+  typedef void* (*ImageAddressCallback)(void* data, mirror::Object* obj);
+
+  static bool Patch(const CompilerDriver* driver, ElfFile* elf_file,
+                    const std::string& oat_location,
+                    ImageAddressCallback cb, void* cb_data,
+                    std::string* error_msg)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  static bool Patch(const CompilerDriver* driver, ElfFile* elf_file,
+                    const OatFile* oat_file, uintptr_t oat_data_begin,
+                    ImageAddressCallback cb, void* cb_data,
+                    std::string* error_msg)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  static bool Patch(const CompilerDriver* driver, ElfFile* elf_file,
+                    const std::string& oat_location,
+                    std::string* error_msg)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    return ElfPatcher::Patch(driver, elf_file, oat_location,
+                             DefaultImageAddressCallback, nullptr, error_msg);
+  }
+
+  static bool Patch(const CompilerDriver* driver, ElfFile* elf_file,
+                    const OatFile* oat_file, uintptr_t oat_data_begin,
+                    std::string* error_msg)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    return ElfPatcher::Patch(driver, elf_file, oat_file, oat_data_begin,
+                             DefaultImageAddressCallback, nullptr, error_msg);
+  }
+
+ private:
+  ElfPatcher(const CompilerDriver* driver, ElfFile* elf_file, const OatFile* oat_file,
+             OatHeader* oat_header, uintptr_t oat_data_begin,
+             ImageAddressCallback cb, void* cb_data, std::string* error_msg)
+      : compiler_driver_(driver), elf_file_(elf_file), oat_file_(oat_file),
+        oat_header_(oat_header), oat_data_begin_(oat_data_begin), get_image_address_(cb),
+        cb_data_(cb_data), error_msg_(error_msg),
+        write_patches_(compiler_driver_->GetCompilerOptions().GetIncludePatchInformation()) {}
+  ~ElfPatcher() {}
+
+  static void* DefaultImageAddressCallback(void* data_unused, mirror::Object* obj) {
+    return static_cast<void*>(obj);
+  }
+
+  bool PatchElf()
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  mirror::ArtMethod* GetTargetMethod(const CompilerDriver::CallPatchInformation* patch)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  mirror::Class* GetTargetType(const CompilerDriver::TypePatchInformation* patch)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  void AddPatch(uintptr_t off);
+
+  void SetPatchLocation(const CompilerDriver::PatchInformation* patch, uint32_t value)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  // Takes the pointer into the oat_file_ and get the pointer in to the ElfFile.
+  uint32_t* GetPatchLocation(uintptr_t patch_ptr);
+
+  bool WriteOutPatchData();
+
+  uintptr_t GetBaseAddressFor(const OatFile* f) {
+    if (f == oat_file_) {
+      return oat_data_begin_;
+    } else {
+      return reinterpret_cast<uintptr_t>(f->Begin());
+    }
+  }
+
+  const CompilerDriver* compiler_driver_;
+
+  // The elf_file containing the oat_data we are patching up
+  ElfFile* elf_file_;
+
+  // The oat_file that is actually loaded.
+  const OatFile* oat_file_;
+
+  // The oat_header_ within the elf_file_
+  OatHeader* oat_header_;
+
+  // Where the elf_file will be loaded during normal runs.
+  uintptr_t oat_data_begin_;
+
+  // Callback to get image addresses.
+  ImageAddressCallback get_image_address_;
+  void* cb_data_;
+
+  std::string* error_msg_;
+  std::vector<uintptr_t> patches_;
+  std::set<uintptr_t> patches_set_;
+  bool write_patches_;
+
+  DISALLOW_COPY_AND_ASSIGN(ElfPatcher);
+};
+
+}  // namespace art
+#endif  // ART_COMPILER_ELF_PATCHER_H_