Only restore JNIEnv in constructor

This commit is contained in:
topjohnwu 2023-04-05 10:13:40 -07:00
parent 7fe012347a
commit 18b1ef6c29

View File

@ -28,7 +28,7 @@ using xstring = jni_hook::string;
static void hook_unloader();
static void unhook_functions();
static void hook_jni_env();
static bool unhook_jni(JNIEnv *env);
static void restore_jni_env(JNIEnv *env);
namespace {
@ -96,8 +96,11 @@ struct HookContext {
HookContext(JNIEnv *env, void *args) :
env(env), args{args}, process(nullptr), pid(-1), info_flags(0),
hook_info_lock(PTHREAD_MUTEX_INITIALIZER) {
static bool unloaded = unhook_jni(env);
should_unmap_zygisk = unloaded;
static bool restored_env = false;
if (!restored_env) {
restore_jni_env(env);
restored_env = true;
}
g_ctx = this;
}
@ -607,6 +610,26 @@ HookContext::~HookContext() {
if (!is_child())
return;
should_unmap_zygisk = true;
// Unhook JNI methods
for (const auto &[clz, methods] : *jni_hook_list) {
if (!methods.empty() && env->RegisterNatives(
env->FindClass(clz.data()), methods.data(),
static_cast<int>(methods.size())) != 0) {
ZLOGE("Failed to restore JNI hook of class [%s]\n", clz.data());
should_unmap_zygisk = false;
}
}
delete jni_hook_list;
jni_hook_list = nullptr;
// Do NOT directly call delete
operator delete(jni_method_map);
// Directly unmap the whole memory block
jni_hook::memory_block::release();
jni_method_map = nullptr;
// Strip out all API function pointers
for (auto &m : modules) {
m.clearApi();
@ -764,37 +787,13 @@ static void unhook_functions() {
}
}
delete plt_hook_list;
plt_hook_list = nullptr;
if (!lsplt::CommitHook()) {
ZLOGE("Failed to restore plt_hook\n");
should_unmap_zygisk = false;
}
}
static bool unhook_jni(JNIEnv *env) {
// Restore JNIEnv
env->functions = old_functions;
delete new_functions;
bool success = true;
// Unhook JNI methods
for (const auto &[clz, methods] : *jni_hook_list) {
if (!methods.empty() && env->RegisterNatives(
env->FindClass(clz.data()), methods.data(),
static_cast<int>(methods.size())) != 0) {
ZLOGE("Failed to restore JNI hook of class [%s]\n", clz.data());
success = false;
}
}
delete jni_hook_list;
// Do NOT call the destructor
operator delete(jni_method_map);
// Directly unmap the whole memory block
jni_hook::memory_block::release();
return success;
}
// -----------------------------------------------------------------
static JNINativeMethod *hookAndSaveJNIMethods(const char *, const JNINativeMethod *, int);
@ -863,6 +862,12 @@ static void hook_jni_env() {
env->functions = new_functions;
}
static void restore_jni_env(JNIEnv *env) {
env->functions = old_functions;
delete new_functions;
new_functions = nullptr;
}
#define HOOK_JNI(method) \
if (methods[i].name == #method##sv) { \
int j = 0; \