naiveproxy/base/android/linker/legacy_linker_jni.cc

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2018-02-02 13:49:39 +03:00
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// This is the version of the Android-specific Chromium linker that uses
// the crazy linker to load libraries.
// This source code *cannot* depend on anything from base/ or the C++
// STL, to keep the final library small, and avoid ugly dependency issues.
#include "legacy_linker_jni.h"
#include <crazy_linker.h>
#include <fcntl.h>
#include <jni.h>
#include <limits.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include "linker_jni.h"
namespace chromium_android_linker {
namespace {
// Retrieve the SDK build version and pass it into the crazy linker. This
// needs to be done early in initialization, before any other crazy linker
// code is run.
// |env| is the current JNI environment handle.
// On success, return true.
bool InitSDKVersionInfo(JNIEnv* env) {
jint value = 0;
if (!InitStaticInt(env, "android/os/Build$VERSION", "SDK_INT", &value))
return false;
crazy_set_sdk_build_version(static_cast<int>(value));
LOG_INFO("Set SDK build version to %d", static_cast<int>(value));
return true;
}
// The linker uses a single crazy_context_t object created on demand.
// There is no need to protect this against concurrent access, locking
// is already handled on the Java side.
crazy_context_t* GetCrazyContext() {
static crazy_context_t* s_crazy_context = nullptr;
if (!s_crazy_context) {
// Create new context.
s_crazy_context = crazy_context_create();
// Ensure libraries located in the same directory as the linker
// can be loaded before system ones.
crazy_context_add_search_path_for_address(
s_crazy_context, reinterpret_cast<void*>(&GetCrazyContext));
}
return s_crazy_context;
}
// A scoped crazy_library_t that automatically closes the handle
// on scope exit, unless Release() has been called.
class ScopedLibrary {
public:
ScopedLibrary() : lib_(nullptr) {}
~ScopedLibrary() {
if (lib_)
crazy_library_close_with_context(lib_, GetCrazyContext());
}
crazy_library_t* Get() { return lib_; }
crazy_library_t** GetPtr() { return &lib_; }
crazy_library_t* Release() {
crazy_library_t* ret = lib_;
lib_ = nullptr;
return ret;
}
private:
crazy_library_t* lib_;
};
template <class LibraryOpener>
bool GenericLoadLibrary(JNIEnv* env,
const char* library_name,
jlong load_address,
jobject lib_info_obj,
const LibraryOpener& opener) {
LOG_INFO("Called for %s, at address 0x%llx", library_name, load_address);
crazy_context_t* context = GetCrazyContext();
if (!IsValidAddress(load_address)) {
LOG_ERROR("Invalid address 0x%llx", load_address);
return false;
}
// Set the desired load address (0 means randomize it).
crazy_context_set_load_address(context, static_cast<size_t>(load_address));
ScopedLibrary library;
if (!opener.Open(library.GetPtr(), library_name, context)) {
return false;
}
crazy_library_info_t info;
if (!crazy_library_get_info(library.Get(), context, &info)) {
LOG_ERROR("Could not get library information for %s: %s",
library_name, crazy_context_get_error(context));
return false;
}
// Release library object to keep it alive after the function returns.
library.Release();
s_lib_info_fields.SetLoadInfo(env,
lib_info_obj,
info.load_address, info.load_size);
LOG_INFO("Success loading library %s", library_name);
return true;
}
// Used for opening the library in a regular file.
class FileLibraryOpener {
public:
bool Open(crazy_library_t** library,
const char* library_name,
crazy_context_t* context) const;
};
bool FileLibraryOpener::Open(crazy_library_t** library,
const char* library_name,
crazy_context_t* context) const {
if (!crazy_library_open(library, library_name, context)) {
LOG_ERROR("Could not open %s: %s",
library_name, crazy_context_get_error(context));
return false;
}
return true;
}
// Used for opening the library in a zip file.
class ZipLibraryOpener {
public:
explicit ZipLibraryOpener(const char* zip_file) : zip_file_(zip_file) { }
bool Open(crazy_library_t** library,
const char* library_name,
crazy_context_t* context) const;
private:
const char* zip_file_;
};
bool ZipLibraryOpener::Open(crazy_library_t** library,
const char* library_name,
crazy_context_t* context) const {
if (!crazy_library_open_in_zip_file(library,
zip_file_,
library_name,
context)) {
LOG_ERROR("Could not open %s in zip file %s: %s",
library_name, zip_file_, crazy_context_get_error(context));
return false;
}
return true;
}
// Load a library with the chromium linker. This will also call its
// JNI_OnLoad() method, which shall register its methods. Note that
// lazy native method resolution will _not_ work after this, because
// Dalvik uses the system's dlsym() which won't see the new library,
// so explicit registration is mandatory.
//
// |env| is the current JNI environment handle.
// |clazz| is the static class handle for org.chromium.base.Linker,
// and is ignored here.
// |library_name| is the library name (e.g. libfoo.so).
// |load_address| is an explicit load address.
// |library_info| is a LibInfo handle used to communicate information
// with the Java side.
// Return true on success.
jboolean LoadLibrary(JNIEnv* env,
jclass clazz,
jstring library_name,
jlong load_address,
jobject lib_info_obj) {
String lib_name(env, library_name);
FileLibraryOpener opener;
return GenericLoadLibrary(env,
lib_name.c_str(),
static_cast<size_t>(load_address),
lib_info_obj,
opener);
}
// Load a library from a zipfile with the chromium linker. The
// library in the zipfile must be uncompressed and page aligned.
// The basename of the library is given. The library is expected
// to be lib/<abi_tag>/crazy.<basename>. The <abi_tag> used will be the
// same as the abi for this linker. The "crazy." prefix is included
// so that the Android Package Manager doesn't extract the library into
// /data/app-lib.
//
// Loading the library will also call its JNI_OnLoad() method, which
// shall register its methods. Note that lazy native method resolution
// will _not_ work after this, because Dalvik uses the system's dlsym()
// which won't see the new library, so explicit registration is mandatory.
//
// |env| is the current JNI environment handle.
// |clazz| is the static class handle for org.chromium.base.Linker,
// and is ignored here.
// |zipfile_name| is the filename of the zipfile containing the library.
// |library_name| is the library base name (e.g. libfoo.so).
// |load_address| is an explicit load address.
// |library_info| is a LibInfo handle used to communicate information
// with the Java side.
// Returns true on success.
jboolean LoadLibraryInZipFile(JNIEnv* env,
jclass clazz,
jstring zipfile_name,
jstring library_name,
jlong load_address,
jobject lib_info_obj) {
String zipfile_name_str(env, zipfile_name);
String lib_name(env, library_name);
ZipLibraryOpener opener(zipfile_name_str.c_str());
return GenericLoadLibrary(env,
lib_name.c_str(),
static_cast<size_t>(load_address),
lib_info_obj,
opener);
}
// Class holding the Java class and method ID for the Java side Linker
// postCallbackOnMainThread method.
struct JavaCallbackBindings_class {
jclass clazz;
jmethodID method_id;
// Initialize an instance.
bool Init(JNIEnv* env, jclass linker_class) {
clazz = reinterpret_cast<jclass>(env->NewGlobalRef(linker_class));
return InitStaticMethodId(env,
linker_class,
"postCallbackOnMainThread",
"(J)V",
&method_id);
}
};
static JavaCallbackBindings_class s_java_callback_bindings;
// Designated receiver function for callbacks from Java. Its name is known
// to the Java side.
// |env| is the current JNI environment handle and is ignored here.
// |clazz| is the static class handle for org.chromium.base.Linker,
// and is ignored here.
// |arg| is a pointer to an allocated crazy_callback_t, deleted after use.
void RunCallbackOnUiThread(JNIEnv* env, jclass clazz, jlong arg) {
crazy_callback_t* callback = reinterpret_cast<crazy_callback_t*>(arg);
LOG_INFO("Called back from java with handler %p, opaque %p",
callback->handler, callback->opaque);
crazy_callback_run(callback);
delete callback;
}
// Request a callback from Java. The supplied crazy_callback_t is valid only
// for the duration of this call, so we copy it to a newly allocated
// crazy_callback_t and then call the Java side's postCallbackOnMainThread.
// This will call back to to our RunCallbackOnUiThread some time
// later on the UI thread.
// |callback_request| is a crazy_callback_t.
// |poster_opaque| is unused.
// Returns true if the callback request succeeds.
static bool PostForLaterExecution(crazy_callback_t* callback_request,
void* poster_opaque UNUSED) {
crazy_context_t* context = GetCrazyContext();
JavaVM* vm;
int minimum_jni_version;
crazy_context_get_java_vm(context,
reinterpret_cast<void**>(&vm),
&minimum_jni_version);
// Do not reuse JNIEnv from JNI_OnLoad, but retrieve our own.
JNIEnv* env;
if (JNI_OK != vm->GetEnv(
reinterpret_cast<void**>(&env), minimum_jni_version)) {
LOG_ERROR("Could not create JNIEnv");
return false;
}
// Copy the callback; the one passed as an argument may be temporary.
crazy_callback_t* callback = new crazy_callback_t();
*callback = *callback_request;
LOG_INFO("Calling back to java with handler %p, opaque %p",
callback->handler, callback->opaque);
jlong arg = static_cast<jlong>(reinterpret_cast<uintptr_t>(callback));
env->CallStaticVoidMethod(
s_java_callback_bindings.clazz, s_java_callback_bindings.method_id, arg);
// Back out and return false if we encounter a JNI exception.
if (env->ExceptionCheck() == JNI_TRUE) {
env->ExceptionDescribe();
env->ExceptionClear();
delete callback;
return false;
}
return true;
}
jboolean CreateSharedRelro(JNIEnv* env,
jclass clazz,
jstring library_name,
jlong load_address,
jobject lib_info_obj) {
String lib_name(env, library_name);
LOG_INFO("Called for %s", lib_name.c_str());
if (!IsValidAddress(load_address)) {
LOG_ERROR("Invalid address 0x%llx", load_address);
return false;
}
ScopedLibrary library;
if (!crazy_library_find_by_name(lib_name.c_str(), library.GetPtr())) {
LOG_ERROR("Could not find %s", lib_name.c_str());
return false;
}
crazy_context_t* context = GetCrazyContext();
size_t relro_start = 0;
size_t relro_size = 0;
int relro_fd = -1;
if (!crazy_library_create_shared_relro(library.Get(),
context,
static_cast<size_t>(load_address),
&relro_start,
&relro_size,
&relro_fd)) {
LOG_ERROR("Could not create shared RELRO sharing for %s: %s\n",
lib_name.c_str(), crazy_context_get_error(context));
return false;
}
s_lib_info_fields.SetRelroInfo(env,
lib_info_obj,
relro_start, relro_size, relro_fd);
return true;
}
jboolean UseSharedRelro(JNIEnv* env,
jclass clazz,
jstring library_name,
jobject lib_info_obj) {
String lib_name(env, library_name);
LOG_INFO("Called for %s, lib_info_ref=%p", lib_name.c_str(), lib_info_obj);
ScopedLibrary library;
if (!crazy_library_find_by_name(lib_name.c_str(), library.GetPtr())) {
LOG_ERROR("Could not find %s", lib_name.c_str());
return false;
}
crazy_context_t* context = GetCrazyContext();
size_t relro_start = 0;
size_t relro_size = 0;
int relro_fd = -1;
s_lib_info_fields.GetRelroInfo(env,
lib_info_obj,
&relro_start, &relro_size, &relro_fd);
LOG_INFO("library=%s relro start=%p size=%p fd=%d",
lib_name.c_str(), (void*)relro_start, (void*)relro_size, relro_fd);
if (!crazy_library_use_shared_relro(library.Get(),
context,
relro_start, relro_size, relro_fd)) {
LOG_ERROR("Could not use shared RELRO for %s: %s",
lib_name.c_str(), crazy_context_get_error(context));
return false;
}
LOG_INFO("Library %s using shared RELRO section!", lib_name.c_str());
return true;
}
const JNINativeMethod kNativeMethods[] = {
{"nativeLoadLibrary",
"("
"Ljava/lang/String;"
"J"
"Lorg/chromium/base/library_loader/Linker$LibInfo;"
")"
"Z",
reinterpret_cast<void*>(&LoadLibrary)},
{"nativeLoadLibraryInZipFile",
"("
"Ljava/lang/String;"
"Ljava/lang/String;"
"J"
"Lorg/chromium/base/library_loader/Linker$LibInfo;"
")"
"Z",
reinterpret_cast<void*>(&LoadLibraryInZipFile)},
{"nativeRunCallbackOnUiThread",
"("
"J"
")"
"V",
reinterpret_cast<void*>(&RunCallbackOnUiThread)},
{"nativeCreateSharedRelro",
"("
"Ljava/lang/String;"
"J"
"Lorg/chromium/base/library_loader/Linker$LibInfo;"
")"
"Z",
reinterpret_cast<void*>(&CreateSharedRelro)},
{"nativeUseSharedRelro",
"("
"Ljava/lang/String;"
"Lorg/chromium/base/library_loader/Linker$LibInfo;"
")"
"Z",
reinterpret_cast<void*>(&UseSharedRelro)},
};
const size_t kNumNativeMethods =
sizeof(kNativeMethods) / sizeof(kNativeMethods[0]);
} // namespace
bool LegacyLinkerJNIInit(JavaVM* vm, JNIEnv* env) {
LOG_INFO("Entering");
// Initialize SDK version info.
LOG_INFO("Retrieving SDK version info");
if (!InitSDKVersionInfo(env))
return false;
// Disable debugger support when needed. See https://crbug.com/796938
#if defined(LEGACY_LINKER_DISABLE_DEBUGGER_SUPPORT)
crazy_set_debugger_support(false);
#endif
// Register native methods.
jclass linker_class;
if (!InitClassReference(env,
"org/chromium/base/library_loader/LegacyLinker",
&linker_class))
return false;
LOG_INFO("Registering native methods");
if (env->RegisterNatives(linker_class, kNativeMethods, kNumNativeMethods) < 0)
return false;
// Resolve and save the Java side Linker callback class and method.
LOG_INFO("Resolving callback bindings");
if (!s_java_callback_bindings.Init(env, linker_class)) {
return false;
}
// Save JavaVM* handle into context.
crazy_context_t* context = GetCrazyContext();
crazy_context_set_java_vm(context, vm, JNI_VERSION_1_4);
// Register the function that the crazy linker can call to post code
// for later execution.
crazy_context_set_callback_poster(context, &PostForLaterExecution, nullptr);
return true;
}
} // namespace chromium_android_linker