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
diff --git a/compiler/Android.mk b/compiler/Android.mk
index ac2f9d6..61ff109 100644
--- a/compiler/Android.mk
+++ b/compiler/Android.mk
@@ -118,6 +118,7 @@
compilers.cc \
compiler.cc \
elf_fixup.cc \
+ elf_patcher.cc \
elf_stripper.cc \
elf_writer.cc \
elf_writer_quick.cc \
diff --git a/compiler/dex/quick_compiler_callbacks.h b/compiler/dex/quick_compiler_callbacks.h
index 7c9614f..cdf71b6 100644
--- a/compiler/dex/quick_compiler_callbacks.h
+++ b/compiler/dex/quick_compiler_callbacks.h
@@ -41,6 +41,11 @@
void ClassRejected(ClassReference ref) OVERRIDE;
+ // We are running in an environment where we can call patchoat safely so we should.
+ bool IsRelocationPossible() OVERRIDE {
+ return true;
+ }
+
private:
VerificationResults* const verification_results_;
DexFileToMethodInlinerMap* const method_inliner_map_;
diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index 9e88c8d..f85bc65 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -955,7 +955,8 @@
if (class_in_image) {
// boot -> app class pointers.
*is_type_initialized = resolved_class->IsInitialized();
- *use_direct_type_ptr = true;
+ // TODO This is somewhat hacky. We should refactor all of this invoke codepath.
+ *use_direct_type_ptr = !GetCompilerOptions().GetIncludePatchInformation();
*direct_type_ptr = reinterpret_cast<uintptr_t>(resolved_class);
return true;
} else {
@@ -1099,6 +1100,9 @@
*direct_method = 0;
bool use_dex_cache = false;
const bool compiling_boot = Runtime::Current()->GetHeap()->IsCompilingBoot();
+ // TODO This is somewhat hacky. We should refactor all of this invoke codepath.
+ const bool force_relocations = (compiling_boot ||
+ GetCompilerOptions().GetIncludePatchInformation());
if (compiler_->IsPortable()) {
if (sharp_type != kStatic && sharp_type != kDirect) {
return;
@@ -1109,7 +1113,7 @@
return;
}
// TODO: support patching on all architectures.
- use_dex_cache = compiling_boot && !support_boot_image_fixup_;
+ use_dex_cache = force_relocations && !support_boot_image_fixup_;
}
bool method_code_in_boot = (method->GetDeclaringClass()->GetClassLoader() == nullptr);
if (!use_dex_cache) {
@@ -1128,8 +1132,8 @@
if (method_code_in_boot) {
*stats_flags |= kFlagDirectCallToBoot | kFlagDirectMethodToBoot;
}
- if (!use_dex_cache && compiling_boot) {
- if (!IsImageClass(method->GetDeclaringClassDescriptor())) {
+ if (!use_dex_cache && force_relocations) {
+ if (!IsImage() || !IsImageClass(method->GetDeclaringClassDescriptor())) {
// We can only branch directly to Methods that are resolved in the DexCache.
// Otherwise we won't invoke the resolution trampoline.
use_dex_cache = true;
@@ -1150,7 +1154,7 @@
if (dex_method_idx != DexFile::kDexNoIndex) {
target_method->dex_method_index = dex_method_idx;
} else {
- if (compiling_boot && !use_dex_cache) {
+ if (force_relocations && !use_dex_cache) {
target_method->dex_method_index = method->GetDexMethodIndex();
target_method->dex_file = method->GetDeclaringClass()->GetDexCache()->GetDexFile();
}
@@ -1167,19 +1171,26 @@
*type = sharp_type;
}
} else {
- bool method_in_image = compiling_boot ||
+ bool method_in_image =
Runtime::Current()->GetHeap()->FindSpaceFromObject(method, false)->IsImageSpace();
- if (method_in_image) {
+ if (method_in_image || compiling_boot) {
+ // We know we must be able to get to the method in the image, so use that pointer.
CHECK(!method->IsAbstract());
*type = sharp_type;
- *direct_method = compiling_boot ? -1 : reinterpret_cast<uintptr_t>(method);
- *direct_code = compiling_boot ? -1 : compiler_->GetEntryPointOf(method);
+ *direct_method = force_relocations ? -1 : reinterpret_cast<uintptr_t>(method);
+ *direct_code = force_relocations ? -1 : compiler_->GetEntryPointOf(method);
target_method->dex_file = method->GetDeclaringClass()->GetDexCache()->GetDexFile();
target_method->dex_method_index = method->GetDexMethodIndex();
} else if (!must_use_direct_pointers) {
// Set the code and rely on the dex cache for the method.
*type = sharp_type;
- *direct_code = compiler_->GetEntryPointOf(method);
+ if (force_relocations) {
+ *direct_code = -1;
+ target_method->dex_file = method->GetDeclaringClass()->GetDexCache()->GetDexFile();
+ target_method->dex_method_index = method->GetDexMethodIndex();
+ } else {
+ *direct_code = compiler_->GetEntryPointOf(method);
+ }
} else {
// Direct pointers were required but none were available.
VLOG(compiler) << "Dex cache devirtualization failed for: " << PrettyMethod(method);
diff --git a/compiler/elf_patcher.cc b/compiler/elf_patcher.cc
new file mode 100644
index 0000000..6112fbb
--- /dev/null
+++ b/compiler/elf_patcher.cc
@@ -0,0 +1,293 @@
+/*
+ * 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.
+ */
+
+#include "elf_patcher.h"
+
+#include <vector>
+#include <set>
+
+#include "elf_file.h"
+#include "elf_utils.h"
+#include "mirror/art_field-inl.h"
+#include "mirror/art_method-inl.h"
+#include "mirror/array-inl.h"
+#include "mirror/class-inl.h"
+#include "mirror/class_loader.h"
+#include "mirror/dex_cache-inl.h"
+#include "mirror/object-inl.h"
+#include "mirror/object_array-inl.h"
+#include "mirror/string-inl.h"
+#include "oat.h"
+#include "os.h"
+#include "utils.h"
+
+namespace art {
+
+bool ElfPatcher::Patch(const CompilerDriver* driver, ElfFile* elf_file,
+ const std::string& oat_location,
+ ImageAddressCallback cb, void* cb_data,
+ std::string* error_msg) {
+ ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
+ const OatFile* oat_file = class_linker->FindOpenedOatFileFromOatLocation(oat_location);
+ if (oat_file == nullptr) {
+ CHECK(Runtime::Current()->IsCompiler());
+ oat_file = OatFile::Open(oat_location, oat_location, NULL, false, error_msg);
+ if (oat_file == nullptr) {
+ *error_msg = StringPrintf("Unable to find or open oat file at '%s': %s", oat_location.c_str(),
+ error_msg->c_str());
+ return false;
+ }
+ CHECK_EQ(class_linker->RegisterOatFile(oat_file), oat_file);
+ }
+ return ElfPatcher::Patch(driver, elf_file, oat_file,
+ reinterpret_cast<uintptr_t>(oat_file->Begin()), cb, cb_data, error_msg);
+}
+
+bool ElfPatcher::Patch(const CompilerDriver* driver, ElfFile* elf, const OatFile* oat_file,
+ uintptr_t oat_data_start, ImageAddressCallback cb, void* cb_data,
+ std::string* error_msg) {
+ Elf32_Shdr* data_sec = elf->FindSectionByName(".rodata");
+ if (data_sec == nullptr) {
+ *error_msg = "Unable to find .rodata section and oat header";
+ return false;
+ }
+ OatHeader* oat_header = reinterpret_cast<OatHeader*>(elf->Begin() + data_sec->sh_offset);
+ if (!oat_header->IsValid()) {
+ *error_msg = "Oat header was not valid";
+ return false;
+ }
+
+ ElfPatcher p(driver, elf, oat_file, oat_header, oat_data_start, cb, cb_data, error_msg);
+ return p.PatchElf();
+}
+
+mirror::ArtMethod* ElfPatcher::GetTargetMethod(const CompilerDriver::CallPatchInformation* patch) {
+ ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
+ StackHandleScope<1> hs(Thread::Current());
+ Handle<mirror::DexCache> dex_cache(
+ hs.NewHandle(class_linker->FindDexCache(*patch->GetTargetDexFile())));
+ mirror::ArtMethod* method = class_linker->ResolveMethod(*patch->GetTargetDexFile(),
+ patch->GetTargetMethodIdx(),
+ dex_cache,
+ NullHandle<mirror::ClassLoader>(),
+ NullHandle<mirror::ArtMethod>(),
+ patch->GetTargetInvokeType());
+ CHECK(method != NULL)
+ << patch->GetTargetDexFile()->GetLocation() << " " << patch->GetTargetMethodIdx();
+ CHECK(!method->IsRuntimeMethod())
+ << patch->GetTargetDexFile()->GetLocation() << " " << patch->GetTargetMethodIdx();
+ CHECK(dex_cache->GetResolvedMethods()->Get(patch->GetTargetMethodIdx()) == method)
+ << patch->GetTargetDexFile()->GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
+ << PrettyMethod(dex_cache->GetResolvedMethods()->Get(patch->GetTargetMethodIdx())) << " "
+ << PrettyMethod(method);
+ return method;
+}
+
+mirror::Class* ElfPatcher::GetTargetType(const CompilerDriver::TypePatchInformation* patch) {
+ ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
+ StackHandleScope<2> hs(Thread::Current());
+ Handle<mirror::DexCache> dex_cache(hs.NewHandle(class_linker->FindDexCache(patch->GetDexFile())));
+ mirror::Class* klass = class_linker->ResolveType(patch->GetDexFile(), patch->GetTargetTypeIdx(),
+ dex_cache, NullHandle<mirror::ClassLoader>());
+ CHECK(klass != NULL)
+ << patch->GetDexFile().GetLocation() << " " << patch->GetTargetTypeIdx();
+ CHECK(dex_cache->GetResolvedTypes()->Get(patch->GetTargetTypeIdx()) == klass)
+ << patch->GetDexFile().GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
+ << PrettyClass(dex_cache->GetResolvedTypes()->Get(patch->GetTargetTypeIdx())) << " "
+ << PrettyClass(klass);
+ return klass;
+}
+
+void ElfPatcher::AddPatch(uintptr_t p) {
+ if (write_patches_ && patches_set_.find(p) == patches_set_.end()) {
+ patches_set_.insert(p);
+ patches_.push_back(p);
+ }
+}
+
+uint32_t* ElfPatcher::GetPatchLocation(uintptr_t patch_ptr) {
+ CHECK_GE(patch_ptr, reinterpret_cast<uintptr_t>(oat_file_->Begin()));
+ uintptr_t off = patch_ptr - reinterpret_cast<uintptr_t>(oat_file_->Begin());
+ uintptr_t ret = reinterpret_cast<uintptr_t>(oat_header_) + off;
+
+ CHECK_GE(ret, reinterpret_cast<uintptr_t>(elf_file_->Begin()));
+ CHECK_LT(ret, reinterpret_cast<uintptr_t>(elf_file_->End()));
+ return reinterpret_cast<uint32_t*>(ret);
+}
+
+void ElfPatcher::SetPatchLocation(const CompilerDriver::PatchInformation* patch, uint32_t value) {
+ ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
+ const void* quick_oat_code = class_linker->GetQuickOatCodeFor(patch->GetDexFile(),
+ patch->GetReferrerClassDefIdx(),
+ patch->GetReferrerMethodIdx());
+ // TODO: make this Thumb2 specific
+ uint8_t* base = reinterpret_cast<uint8_t*>(reinterpret_cast<uintptr_t>(quick_oat_code) & ~0x1);
+ uintptr_t patch_ptr = reinterpret_cast<uintptr_t>(base + patch->GetLiteralOffset());
+ uint32_t* patch_location = GetPatchLocation(patch_ptr);
+ if (kIsDebugBuild) {
+ if (patch->IsCall()) {
+ const CompilerDriver::CallPatchInformation* cpatch = patch->AsCall();
+ const DexFile::MethodId& id =
+ cpatch->GetTargetDexFile()->GetMethodId(cpatch->GetTargetMethodIdx());
+ uint32_t expected = reinterpret_cast<uintptr_t>(&id) & 0xFFFFFFFF;
+ uint32_t actual = *patch_location;
+ CHECK(actual == expected || actual == value) << std::hex
+ << "actual=" << actual
+ << "expected=" << expected
+ << "value=" << value;
+ }
+ if (patch->IsType()) {
+ const CompilerDriver::TypePatchInformation* tpatch = patch->AsType();
+ const DexFile::TypeId& id = tpatch->GetDexFile().GetTypeId(tpatch->GetTargetTypeIdx());
+ uint32_t expected = reinterpret_cast<uintptr_t>(&id) & 0xFFFFFFFF;
+ uint32_t actual = *patch_location;
+ CHECK(actual == expected || actual == value) << std::hex
+ << "actual=" << actual
+ << "expected=" << expected
+ << "value=" << value;
+ }
+ }
+ *patch_location = value;
+ oat_header_->UpdateChecksum(patch_location, sizeof(value));
+
+ if (patch->IsCall() && patch->AsCall()->IsRelative()) {
+ // We never record relative patches.
+ return;
+ }
+ uintptr_t loc = patch_ptr - (reinterpret_cast<uintptr_t>(oat_file_->Begin()) +
+ oat_header_->GetExecutableOffset());
+ CHECK_GT(patch_ptr, reinterpret_cast<uintptr_t>(oat_file_->Begin()) +
+ oat_header_->GetExecutableOffset());
+ CHECK_LT(loc, oat_file_->Size() - oat_header_->GetExecutableOffset());
+ AddPatch(loc);
+}
+
+bool ElfPatcher::PatchElf() {
+ // TODO if we are adding patches the resulting ELF file might have a
+ // potentially rather large amount of free space where patches might have been
+ // placed. We should adjust the ELF file to get rid of this excess space.
+ if (write_patches_) {
+ patches_.reserve(compiler_driver_->GetCodeToPatch().size() +
+ compiler_driver_->GetMethodsToPatch().size() +
+ compiler_driver_->GetClassesToPatch().size());
+ }
+ Thread* self = Thread::Current();
+ ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
+ const char* old_cause = self->StartAssertNoThreadSuspension("ElfPatcher");
+
+ typedef std::vector<const CompilerDriver::CallPatchInformation*> CallPatches;
+ const CallPatches& code_to_patch = compiler_driver_->GetCodeToPatch();
+ for (size_t i = 0; i < code_to_patch.size(); i++) {
+ const CompilerDriver::CallPatchInformation* patch = code_to_patch[i];
+
+ mirror::ArtMethod* target = GetTargetMethod(patch);
+ uintptr_t quick_code = reinterpret_cast<uintptr_t>(class_linker->GetQuickOatCodeFor(target));
+ DCHECK_NE(quick_code, 0U) << PrettyMethod(target);
+ const OatFile* target_oat = class_linker->FindOpenedOatFileForDexFile(*patch->GetTargetDexFile());
+ // Get where the data actually starts. if target is this oat_file_ it is oat_data_start_,
+ // otherwise it is wherever target_oat is loaded.
+ uintptr_t oat_data_addr = GetBaseAddressFor(target_oat);
+ uintptr_t code_base = reinterpret_cast<uintptr_t>(target_oat->Begin());
+ uintptr_t code_offset = quick_code - code_base;
+ bool is_quick_offset = false;
+ if (quick_code == reinterpret_cast<uintptr_t>(GetQuickToInterpreterBridge())) {
+ is_quick_offset = true;
+ code_offset = oat_header_->GetQuickToInterpreterBridgeOffset();
+ } else if (quick_code ==
+ reinterpret_cast<uintptr_t>(class_linker->GetQuickGenericJniTrampoline())) {
+ CHECK(target->IsNative());
+ is_quick_offset = true;
+ code_offset = oat_header_->GetQuickGenericJniTrampolineOffset();
+ }
+ uintptr_t value;
+ if (patch->IsRelative()) {
+ // value to patch is relative to the location being patched
+ const void* quick_oat_code =
+ class_linker->GetQuickOatCodeFor(patch->GetDexFile(),
+ patch->GetReferrerClassDefIdx(),
+ patch->GetReferrerMethodIdx());
+ if (is_quick_offset) {
+ // If its a quick offset it means that we are doing a relative patch from the class linker
+ // oat_file to the elf_patcher oat_file so we need to adjust the quick oat code to be the
+ // one in the output oat_file (ie where it is actually going to be loaded).
+ quick_code = PointerToLowMemUInt32(reinterpret_cast<void*>(oat_data_addr + code_offset));
+ quick_oat_code =
+ reinterpret_cast<const void*>(reinterpret_cast<uintptr_t>(quick_oat_code) +
+ oat_data_addr - code_base);
+ }
+ uintptr_t base = reinterpret_cast<uintptr_t>(quick_oat_code);
+ uintptr_t patch_location = base + patch->GetLiteralOffset();
+ value = quick_code - patch_location + patch->RelativeOffset();
+ } else if (code_offset != 0) {
+ value = PointerToLowMemUInt32(reinterpret_cast<void*>(oat_data_addr + code_offset));
+ } else {
+ value = 0;
+ }
+ SetPatchLocation(patch, value);
+ }
+
+ const CallPatches& methods_to_patch = compiler_driver_->GetMethodsToPatch();
+ for (size_t i = 0; i < methods_to_patch.size(); i++) {
+ const CompilerDriver::CallPatchInformation* patch = methods_to_patch[i];
+ mirror::ArtMethod* target = GetTargetMethod(patch);
+ SetPatchLocation(patch, PointerToLowMemUInt32(get_image_address_(cb_data_, target)));
+ }
+
+ const std::vector<const CompilerDriver::TypePatchInformation*>& classes_to_patch =
+ compiler_driver_->GetClassesToPatch();
+ for (size_t i = 0; i < classes_to_patch.size(); i++) {
+ const CompilerDriver::TypePatchInformation* patch = classes_to_patch[i];
+ mirror::Class* target = GetTargetType(patch);
+ SetPatchLocation(patch, PointerToLowMemUInt32(get_image_address_(cb_data_, target)));
+ }
+
+ self->EndAssertNoThreadSuspension(old_cause);
+
+ if (write_patches_) {
+ return WriteOutPatchData();
+ }
+ return true;
+}
+
+bool ElfPatcher::WriteOutPatchData() {
+ Elf32_Shdr* shdr = elf_file_->FindSectionByName(".oat_patches");
+ if (shdr != nullptr) {
+ CHECK_EQ(shdr, elf_file_->FindSectionByType(SHT_OAT_PATCH))
+ << "Incorrect type for .oat_patches section";
+ CHECK_LE(patches_.size() * sizeof(uintptr_t), shdr->sh_size)
+ << "We got more patches than anticipated";
+ CHECK_LE(reinterpret_cast<uintptr_t>(elf_file_->Begin()) + shdr->sh_offset + shdr->sh_size,
+ reinterpret_cast<uintptr_t>(elf_file_->End())) << "section is too large";
+ CHECK(shdr == &elf_file_->GetSectionHeader(elf_file_->GetSectionHeaderNum() - 1) ||
+ shdr->sh_offset + shdr->sh_size <= (shdr + 1)->sh_offset)
+ << "Section overlaps onto next section";
+ // It's mmap'd so we can just memcpy.
+ memcpy(elf_file_->Begin() + shdr->sh_offset, patches_.data(),
+ patches_.size() * sizeof(uintptr_t));
+ // TODO We should fill in the newly empty space between the last patch and
+ // the start of the next section by moving the following sections down if
+ // possible.
+ shdr->sh_size = patches_.size() * sizeof(uintptr_t);
+ return true;
+ } else {
+ LOG(ERROR) << "Unable to find section header for SHT_OAT_PATCH";
+ *error_msg_ = "Unable to find section to write patch information to in ";
+ *error_msg_ += elf_file_->GetFile().GetPath();
+ return false;
+ }
+}
+
+} // namespace art
diff --git a/compiler/elf_patcher.h b/compiler/elf_patcher.h
new file mode 100644
index 0000000..0a9f0a01
--- /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_
diff --git a/compiler/image_test.cc b/compiler/image_test.cc
index fe4fcd4..3005e56 100644
--- a/compiler/image_test.cc
+++ b/compiler/image_test.cc
@@ -80,7 +80,7 @@
t.NewTiming("WriteElf");
ScopedObjectAccess soa(Thread::Current());
SafeMap<std::string, std::string> key_value_store;
- OatWriter oat_writer(class_linker->GetBootClassPath(), 0, 0, compiler_driver_.get(), &timings,
+ OatWriter oat_writer(class_linker->GetBootClassPath(), 0, 0, 0, compiler_driver_.get(), &timings,
&key_value_store);
bool success = compiler_driver_->WriteElf(GetTestAndroidRoot(),
!kIsTargetBuild,
diff --git a/compiler/image_writer.cc b/compiler/image_writer.cc
index 8ef2964..d102bbc 100644
--- a/compiler/image_writer.cc
+++ b/compiler/image_writer.cc
@@ -29,6 +29,7 @@
#include "driver/compiler_driver.h"
#include "elf_file.h"
#include "elf_utils.h"
+#include "elf_patcher.h"
#include "elf_writer.h"
#include "gc/accounting/card_table-inl.h"
#include "gc/accounting/heap_bitmap.h"
@@ -84,7 +85,7 @@
return false;
}
std::string error_msg;
- oat_file_ = OatFile::OpenWritable(oat_file.get(), oat_location, &error_msg);
+ oat_file_ = OatFile::OpenReadable(oat_file.get(), oat_location, &error_msg);
if (oat_file_ == nullptr) {
LOG(ERROR) << "Failed to open writable oat file " << oat_filename << " for " << oat_location
<< ": " << error_msg;
@@ -801,214 +802,35 @@
}
}
-static ArtMethod* GetTargetMethod(const CompilerDriver::CallPatchInformation* patch)
- SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
- ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
- StackHandleScope<1> hs(Thread::Current());
- Handle<mirror::DexCache> dex_cache(
- hs.NewHandle(class_linker->FindDexCache(*patch->GetTargetDexFile())));
- ArtMethod* method = class_linker->ResolveMethod(*patch->GetTargetDexFile(),
- patch->GetTargetMethodIdx(),
- dex_cache,
- NullHandle<mirror::ClassLoader>(),
- NullHandle<mirror::ArtMethod>(),
- patch->GetTargetInvokeType());
- CHECK(method != NULL)
- << patch->GetTargetDexFile()->GetLocation() << " " << patch->GetTargetMethodIdx();
- CHECK(!method->IsRuntimeMethod())
- << patch->GetTargetDexFile()->GetLocation() << " " << patch->GetTargetMethodIdx();
- CHECK(dex_cache->GetResolvedMethods()->Get(patch->GetTargetMethodIdx()) == method)
- << patch->GetTargetDexFile()->GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
- << PrettyMethod(dex_cache->GetResolvedMethods()->Get(patch->GetTargetMethodIdx())) << " "
- << PrettyMethod(method);
- return method;
-}
-
-static Class* GetTargetType(const CompilerDriver::TypePatchInformation* patch)
- SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
- ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
- StackHandleScope<2> hs(Thread::Current());
- Handle<mirror::DexCache> dex_cache(hs.NewHandle(class_linker->FindDexCache(patch->GetDexFile())));
- Class* klass = class_linker->ResolveType(patch->GetDexFile(), patch->GetTargetTypeIdx(),
- dex_cache, NullHandle<mirror::ClassLoader>());
- CHECK(klass != NULL)
- << patch->GetDexFile().GetLocation() << " " << patch->GetTargetTypeIdx();
- CHECK(dex_cache->GetResolvedTypes()->Get(patch->GetTargetTypeIdx()) == klass)
- << patch->GetDexFile().GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
- << PrettyClass(dex_cache->GetResolvedTypes()->Get(patch->GetTargetTypeIdx())) << " "
- << PrettyClass(klass);
- return klass;
+static OatHeader* GetOatHeaderFromElf(ElfFile* elf) {
+ Elf32_Shdr* data_sec = elf->FindSectionByName(".rodata");
+ if (data_sec == nullptr) {
+ return nullptr;
+ }
+ return reinterpret_cast<OatHeader*>(elf->Begin() + data_sec->sh_offset);
}
void ImageWriter::PatchOatCodeAndMethods(File* elf_file) {
- std::vector<uintptr_t> patches;
- std::set<uintptr_t> patches_set;
- auto maybe_push = [&patches, &patches_set] (uintptr_t p) {
- if (patches_set.find(p) == patches_set.end()) {
- patches.push_back(p);
- patches_set.insert(p);
- }
- };
- const bool add_patches = compiler_driver_.GetCompilerOptions().GetIncludePatchInformation();
- if (add_patches) {
- // TODO if we are adding patches the resulting ELF file might have a potentially rather large
- // amount of free space where patches might have been placed. We should adjust the ELF file to
- // get rid of this excess space.
- patches.reserve(compiler_driver_.GetCodeToPatch().size() +
- compiler_driver_.GetMethodsToPatch().size() +
- compiler_driver_.GetClassesToPatch().size());
+ std::string error_msg;
+ std::unique_ptr<ElfFile> elf(ElfFile::Open(elf_file, PROT_READ|PROT_WRITE,
+ MAP_SHARED, &error_msg));
+ if (elf.get() == nullptr) {
+ LOG(FATAL) << "Unable patch oat file: " << error_msg;
+ return;
}
- uintptr_t loc = 0;
- Thread* self = Thread::Current();
- ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
- const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter");
-
- typedef std::vector<const CompilerDriver::CallPatchInformation*> CallPatches;
- const CallPatches& code_to_patch = compiler_driver_.GetCodeToPatch();
- for (size_t i = 0; i < code_to_patch.size(); i++) {
- const CompilerDriver::CallPatchInformation* patch = code_to_patch[i];
- ArtMethod* target = GetTargetMethod(patch);
- uintptr_t quick_code = reinterpret_cast<uintptr_t>(class_linker->GetQuickOatCodeFor(target));
- DCHECK_NE(quick_code, 0U) << PrettyMethod(target);
- uintptr_t code_base = reinterpret_cast<uintptr_t>(&oat_file_->GetOatHeader());
- uintptr_t code_offset = quick_code - code_base;
- bool is_quick_offset = false;
- if (quick_code == reinterpret_cast<uintptr_t>(GetQuickToInterpreterBridge())) {
- is_quick_offset = true;
- code_offset = quick_to_interpreter_bridge_offset_;
- } else if (quick_code ==
- reinterpret_cast<uintptr_t>(class_linker->GetQuickGenericJniTrampoline())) {
- CHECK(target->IsNative());
- is_quick_offset = true;
- code_offset = quick_generic_jni_trampoline_offset_;
- }
- uintptr_t value;
- if (patch->IsRelative()) {
- // value to patch is relative to the location being patched
- const void* quick_oat_code =
- class_linker->GetQuickOatCodeFor(patch->GetDexFile(),
- patch->GetReferrerClassDefIdx(),
- patch->GetReferrerMethodIdx());
- if (is_quick_offset) {
- // If its a quick offset it means that we are doing a relative patch from the class linker
- // oat_file to the image writer oat_file so we need to adjust the quick oat code to be the
- // one in the image writer oat_file.
- quick_code = PointerToLowMemUInt32(GetOatAddress(code_offset));
- quick_oat_code =
- reinterpret_cast<const void*>(reinterpret_cast<uintptr_t>(quick_oat_code) +
- reinterpret_cast<uintptr_t>(oat_data_begin_) - code_base);
- }
- uintptr_t base = reinterpret_cast<uintptr_t>(quick_oat_code);
- uintptr_t patch_location = base + patch->GetLiteralOffset();
- value = quick_code - patch_location + patch->RelativeOffset();
- } else {
- value = PointerToLowMemUInt32(GetOatAddress(code_offset));
- }
- SetPatchLocation(patch, value, &loc);
- if (add_patches && !patch->AsCall()->IsRelative()) {
- maybe_push(loc);
- }
+ if (!ElfPatcher::Patch(&compiler_driver_, elf.get(), oat_file_,
+ reinterpret_cast<uintptr_t>(oat_data_begin_),
+ GetImageAddressCallback, reinterpret_cast<void*>(this),
+ &error_msg)) {
+ LOG(FATAL) << "unable to patch oat file: " << error_msg;
+ return;
}
+ OatHeader* oat_header = GetOatHeaderFromElf(elf.get());
+ CHECK(oat_header != nullptr);
+ CHECK(oat_header->IsValid());
- const CallPatches& methods_to_patch = compiler_driver_.GetMethodsToPatch();
- for (size_t i = 0; i < methods_to_patch.size(); i++) {
- const CompilerDriver::CallPatchInformation* patch = methods_to_patch[i];
- ArtMethod* target = GetTargetMethod(patch);
- SetPatchLocation(patch, PointerToLowMemUInt32(GetImageAddress(target)), &loc);
- if (add_patches && !patch->AsCall()->IsRelative()) {
- maybe_push(loc);
- }
- }
-
- const std::vector<const CompilerDriver::TypePatchInformation*>& classes_to_patch =
- compiler_driver_.GetClassesToPatch();
- for (size_t i = 0; i < classes_to_patch.size(); i++) {
- const CompilerDriver::TypePatchInformation* patch = classes_to_patch[i];
- Class* target = GetTargetType(patch);
- SetPatchLocation(patch, PointerToLowMemUInt32(GetImageAddress(target)), &loc);
- if (add_patches) {
- maybe_push(loc);
- }
- }
-
- // Update the image header with the new checksum after patching
ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
- image_header->SetOatChecksum(oat_file_->GetOatHeader().GetChecksum());
- self->EndAssertNoThreadSuspension(old_cause);
-
- // Update the ElfFiles SHT_OAT_PATCH section to include the patches.
- if (add_patches) {
- std::string err;
- // TODO we are mapping in the contents of this file twice. We should be able
- // to do it only once, which would be better.
- std::unique_ptr<ElfFile> file(ElfFile::Open(elf_file, true, false, &err));
- if (file == nullptr) {
- LOG(ERROR) << err;
- }
- Elf32_Shdr* shdr = file->FindSectionByName(".oat_patches");
- if (shdr != nullptr) {
- CHECK_EQ(shdr, file->FindSectionByType(SHT_OAT_PATCH))
- << "Incorrect type for .oat_patches section";
- CHECK_LE(patches.size() * sizeof(uintptr_t), shdr->sh_size)
- << "We got more patches than anticipated";
- CHECK_LE(reinterpret_cast<uintptr_t>(file->Begin()) + shdr->sh_offset + shdr->sh_size,
- reinterpret_cast<uintptr_t>(file->End())) << "section is too large";
- CHECK(shdr == &file->GetSectionHeader(file->GetSectionHeaderNum() - 1) ||
- shdr->sh_offset + shdr->sh_size <= (shdr + 1)->sh_offset)
- << "Section overlaps onto next section";
- // It's mmap'd so we can just memcpy.
- memcpy(file->Begin() + shdr->sh_offset, patches.data(), patches.size()*sizeof(uintptr_t));
- // TODO We should fill in the newly empty space between the last patch and the start of the
- // next section by moving the following sections down if possible.
- shdr->sh_size = patches.size() * sizeof(uintptr_t);
- } else {
- LOG(ERROR) << "Unable to find section header for SHT_OAT_PATCH";
- }
- }
-}
-
-void ImageWriter::SetPatchLocation(const CompilerDriver::PatchInformation* patch, uint32_t value,
- uintptr_t* patched_ptr) {
- ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
- const void* quick_oat_code = class_linker->GetQuickOatCodeFor(patch->GetDexFile(),
- patch->GetReferrerClassDefIdx(),
- patch->GetReferrerMethodIdx());
- OatHeader& oat_header = const_cast<OatHeader&>(oat_file_->GetOatHeader());
- // TODO: make this Thumb2 specific
- uint8_t* base = reinterpret_cast<uint8_t*>(reinterpret_cast<uintptr_t>(quick_oat_code) & ~0x1);
- uint32_t* patch_location = reinterpret_cast<uint32_t*>(base + patch->GetLiteralOffset());
- if (kIsDebugBuild) {
- if (patch->IsCall()) {
- const CompilerDriver::CallPatchInformation* cpatch = patch->AsCall();
- const DexFile::MethodId& id = cpatch->GetTargetDexFile()->GetMethodId(cpatch->GetTargetMethodIdx());
- uint32_t expected = reinterpret_cast<uintptr_t>(&id) & 0xFFFFFFFF;
- uint32_t actual = *patch_location;
- CHECK(actual == expected || actual == value) << std::hex
- << "actual=" << actual
- << "expected=" << expected
- << "value=" << value;
- }
- if (patch->IsType()) {
- const CompilerDriver::TypePatchInformation* tpatch = patch->AsType();
- const DexFile::TypeId& id = tpatch->GetDexFile().GetTypeId(tpatch->GetTargetTypeIdx());
- uint32_t expected = reinterpret_cast<uintptr_t>(&id) & 0xFFFFFFFF;
- uint32_t actual = *patch_location;
- CHECK(actual == expected || actual == value) << std::hex
- << "actual=" << actual
- << "expected=" << expected
- << "value=" << value;
- }
- }
- *patch_location = value;
- oat_header.UpdateChecksum(patch_location, sizeof(value));
-
- uintptr_t loc = reinterpret_cast<uintptr_t>(patch_location) -
- (reinterpret_cast<uintptr_t>(oat_file_->Begin()) + oat_header.GetExecutableOffset());
- CHECK_GT(reinterpret_cast<uintptr_t>(patch_location),
- reinterpret_cast<uintptr_t>(oat_file_->Begin()) + oat_header.GetExecutableOffset());
- CHECK_LT(loc, oat_file_->Size() - oat_header.GetExecutableOffset());
-
- *patched_ptr = loc;
+ image_header->SetOatChecksum(oat_header->GetChecksum());
}
} // namespace art
diff --git a/compiler/image_writer.h b/compiler/image_writer.h
index cf5bc93..e8bcf7f 100644
--- a/compiler/image_writer.h
+++ b/compiler/image_writer.h
@@ -70,6 +70,11 @@
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
size_t GetImageOffset(mirror::Object* object) const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+ static void* GetImageAddressCallback(void* writer, mirror::Object* obj)
+ SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+ return reinterpret_cast<ImageWriter*>(writer)->GetImageAddress(obj);
+ }
+
mirror::Object* GetImageAddress(mirror::Object* object) const
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
if (object == NULL) {
@@ -159,9 +164,6 @@
// Patches references in OatFile to expect runtime addresses.
void PatchOatCodeAndMethods(File* elf_file)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
- void SetPatchLocation(const CompilerDriver::PatchInformation* patch, uint32_t value,
- uintptr_t* patched_location)
- SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
const CompilerDriver& compiler_driver_;
diff --git a/compiler/oat_test.cc b/compiler/oat_test.cc
index 84f0b3c..11d1728 100644
--- a/compiler/oat_test.cc
+++ b/compiler/oat_test.cc
@@ -120,6 +120,7 @@
OatWriter oat_writer(class_linker->GetBootClassPath(),
42U,
4096U,
+ 0,
compiler_driver_.get(),
&timings,
&key_value_store);
@@ -183,7 +184,7 @@
TEST_F(OatTest, OatHeaderSizeCheck) {
// If this test is failing and you have to update these constants,
// it is time to update OatHeader::kOatVersion
- EXPECT_EQ(80U, sizeof(OatHeader));
+ EXPECT_EQ(84U, sizeof(OatHeader));
EXPECT_EQ(8U, sizeof(OatMethodOffsets));
EXPECT_EQ(24U, sizeof(OatQuickMethodHeader));
EXPECT_EQ(79 * GetInstructionSetPointerSize(kRuntimeISA), sizeof(QuickEntryPoints));
diff --git a/compiler/oat_writer.cc b/compiler/oat_writer.cc
index 63a3c8c..22f36f4 100644
--- a/compiler/oat_writer.cc
+++ b/compiler/oat_writer.cc
@@ -50,6 +50,7 @@
OatWriter::OatWriter(const std::vector<const DexFile*>& dex_files,
uint32_t image_file_location_oat_checksum,
uintptr_t image_file_location_oat_begin,
+ int32_t image_patch_delta,
const CompilerDriver* compiler,
TimingLogger* timings,
SafeMap<std::string, std::string>* key_value_store)
@@ -57,6 +58,7 @@
dex_files_(&dex_files),
image_file_location_oat_checksum_(image_file_location_oat_checksum),
image_file_location_oat_begin_(image_file_location_oat_begin),
+ image_patch_delta_(image_patch_delta),
key_value_store_(key_value_store),
oat_header_(NULL),
size_dex_file_alignment_(0),
@@ -126,6 +128,7 @@
CHECK_EQ(dex_files_->size(), oat_dex_files_.size());
CHECK_EQ(compiler->IsImage(),
key_value_store_->find(OatHeader::kImageLocationKey) == key_value_store_->end());
+ CHECK_ALIGNED(image_patch_delta_, kPageSize);
}
OatWriter::~OatWriter() {
@@ -808,6 +811,7 @@
oat_header_->SetExecutableOffset(offset);
size_executable_offset_alignment_ = offset - old_offset;
if (compiler_driver_->IsImage()) {
+ CHECK_EQ(image_patch_delta_, 0);
InstructionSet instruction_set = compiler_driver_->GetInstructionSet();
#define DO_TRAMPOLINE(field, fn_name) \
@@ -840,6 +844,7 @@
oat_header_->SetQuickImtConflictTrampolineOffset(0);
oat_header_->SetQuickResolutionTrampolineOffset(0);
oat_header_->SetQuickToInterpreterBridgeOffset(0);
+ oat_header_->SetImagePatchDelta(image_patch_delta_);
}
return offset;
}
diff --git a/compiler/oat_writer.h b/compiler/oat_writer.h
index 3d34956..945048e 100644
--- a/compiler/oat_writer.h
+++ b/compiler/oat_writer.h
@@ -79,6 +79,7 @@
OatWriter(const std::vector<const DexFile*>& dex_files,
uint32_t image_file_location_oat_checksum,
uintptr_t image_file_location_oat_begin,
+ int32_t image_patch_delta,
const CompilerDriver* compiler,
TimingLogger* timings,
SafeMap<std::string, std::string>* key_value_store);
@@ -253,6 +254,7 @@
// dependencies on the image.
uint32_t image_file_location_oat_checksum_;
uintptr_t image_file_location_oat_begin_;
+ int32_t image_patch_delta_;
// data to write
SafeMap<std::string, std::string>* key_value_store_;