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12章内容提交
This commit is contained in:
dqzg12300
parent
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commit
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@ -606,6 +606,7 @@ extern uint32_t JniMethodStart(Thread* self) {
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// 当前开始函数为要监控的目标函数时，则开启输出JNI
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if(strstr(methodname.c_str(),runtime->GetConfigItem().jniFuncName)){
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runtime->GetConfigItem().jniEnable=true;
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ALOGD("mikrom enter jni %s",methodname.c_str());
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}
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}
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//endadd
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@ -628,6 +629,7 @@ extern void JniMethodEnd(uint32_t saved_local_ref_cookie, Thread* self) {
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// 当前结束函数为要监控的目标函数时，则关闭输出JNI
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if(strstr(methodname.c_str(),runtime->GetConfigItem().jniFuncName)){
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runtime->GetConfigItem().jniEnable=false;
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ALOGD("mikrom leave jni %s",methodname.c_str());
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}
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}
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//endadd
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@ -635,6 +637,25 @@ extern void JniMethodEnd(uint32_t saved_local_ref_cookie, Thread* self) {
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GoToRunnable(self);
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PopLocalReferences(saved_local_ref_cookie, self);
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}
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static mirror::Object* JniMethodEndWithReferenceHandleResult(jobject result,
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uint32_t saved_local_ref_cookie,
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Thread* self)
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NO_THREAD_SAFETY_ANALYSIS {
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//add
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Runtime* runtime=Runtime::Current();
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if(runtime->GetConfigItem().isJNIMethodPrint){
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ArtMethod* native_method = *self->GetManagedStack()->GetTopQuickFrame();
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std::string methodname=native_method->PrettyMethod();
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if(strstr(methodname.c_str(),runtime->GetConfigItem().jniFuncName)){
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runtime->GetConfigItem().jniEnable=false;
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ALOGD("mikrom leave jni %s",methodname.c_str());
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}
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}
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//endadd
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...
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}
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```
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## 12.5 打桩函数分类
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@ -691,9 +712,9 @@ void ShowVarArgs(const ScopedObjectAccessAlreadyRunnable& soa,const char* funcna
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std::string temp;
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const char* className= c->GetDescriptor(&temp);
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ArtMethod* method = jni::DecodeArtMethod(methodID);
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pthread_t threadId = pthread_self();
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pid_t pid = getpid();
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// 前面加上标志是为了方便搜索日志
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ALOGD("%s /* TID %ld */","mikrom",threadId);
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ALOGD("%s /* TID %d */","mikrom",pid);
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ALOGD("%s [+] JNIEnv->%s","mikrom",funcname);
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ALOGD("%s |- jclass :%s","mikrom",className);
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ALOGD("%s |- char* :%p","mikrom",name);
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@ -751,10 +772,14 @@ void ShowVarArgs(const ScopedObjectAccessAlreadyRunnable& ,
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if(!HasShow()){
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return;
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}
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pthread_t threadId = pthread_self();
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ALOGD("%s /* TID %ld */","mikrom",threadId);
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pid_t pid = getpid();
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ALOGD("%s /* TID %d */","mikrom",pid);
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ALOGD("%s [+] JNIEnv->%s","mikrom",funcname);
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if(is_copy== nullptr){
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ALOGD("%s |- jboolean* : %d","mikrom",false);
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}else{
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ALOGD("%s |- jboolean* : %d","mikrom",*is_copy);
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}
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ALOGD("%s |= char* : %s","mikrom",data);
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}
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```
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@ -799,8 +824,8 @@ void ShowVarArgs(const ScopedObjectAccessAlreadyRunnable& ,
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if(!HasShow()){
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return;
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}
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pthread_t threadId = pthread_self();
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ALOGD("%s /* TID %ld */","mikrom",threadId);
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pid_t pid = getpid();
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ALOGD("%s /* TID %d */","mikrom",pid);
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ALOGD("%s [+] JNIEnv->%s","mikrom",funcname);
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ALOGD("%s |- char* : %d","mikrom",data);
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}
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@ -824,11 +849,523 @@ static jstring NewStringUTF(JNIEnv* env, const char* utf) {
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这个`JNI`函数不同于前面几种函数，在前几个函数中，参数是明确固定的，而`CallObjectMethodV`是通过`JNI`，调用一个`java`函数，而为此`java`函数提供的所有参数的类型，以及参数个数。都是未知的。而这些参数的信息同样是需要打桩展示出来的。
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将测试样例中，被调用的`java`函数进行调整，将测试函数新增参数，并且使用`JniTrace`观察`CallObjectMethodV`的输出结果。样例函数修改如下。
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```java
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public String demo(int a,float b,long c,String d){
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return a+b+c+d;
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}
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```
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同时修改`native`函数中使用`JNI`调用的逻辑。
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```c++
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extern "C" JNIEXPORT jstring JNICALL
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Java_cn_mik_nativedemo_MainActivity_stringFromJNI(
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JNIEnv* env,
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jobject obj /* this */) {
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jclass cls= env->FindClass("cn/mik/nativedemo/MainActivity");
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jmethodID mid=env->GetMethodID(cls,"demo", "(IFLjava/lang/String;)Ljava/lang/String;");
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jstring c=env->NewStringUTF("newdemo");
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jstring data= (jstring)env->CallObjectMethod(obj,mid,1,2.0f,c);
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std::string datatmp= env->GetStringUTFChars(data,nullptr);
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return env->NewStringUTF(datatmp.c_str());
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}
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```
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再次使用`JniTrace`观察到的`CallObjectMethodV`输出如下。
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```
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/* TID 18863 */
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2169 ms [+] JNIEnv->CallObjectMethodV
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2169 ms |- JNIEnv* : 0x704e856090
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2169 ms |- jobject : 0x7fe4d55d38
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2169 ms |- jmethodID : 0x3d { demo(IFLjava/lang/String;)Ljava/lang/String; }
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2169 ms |- va_list : 0x7fe4d55b30
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2169 ms |: jint : 1
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2169 ms |: jfloat : 2
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2169 ms |: jstring : 0x81 { newdemo }
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2169 ms |= jobject : 0x95 { java/lang/String }
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2169 ms ------------------------------------------------------Backtrace------------------------------------------------------
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2169 ms |-> 0x6f5d458ae4: _ZN7_JNIEnv16CallObjectMethodEP8_jobjectP10_jmethodIDz+0xc4 (libnativedemo.so:0x6f5d44a000)
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2169 ms |-> 0x6f5d458ae4: _ZN7_JNIEnv16CallObjectMethodEP8_jobjectP10_jmethodIDz+0xc4 (libnativedemo.so:0x6f5d44a000)
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```
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从日志中能看到，参数列表被解析后将具体的值进行输出，而返回值的部分，如果是`jobject`，则将其类型进行输出。明白具体需求后，接着就可以开始根据`CallObjectMethodV`类型参数定义来准备打桩函数了。定义描述如下。
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```c++
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static jobject CallObjectMethodV(JNIEnv* env, jobject obj, jmethodID mid, va_list args);
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```
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根据参考，需要输出调用的目标函数，参数，以及其返回值。而其他的类似调用函数的情况，和该函数差不多的处理，只是返回值的输出不同。优化后的打桩函数如下。
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```c++
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// 输出JNI的参数部分
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void ShowVarArgs(const ScopedObjectAccessAlreadyRunnable& soa,
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const char* funcname,
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jmethodID mid,
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va_list vaList){
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if(!HasShow()){
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return;
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}
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ArtMethod* method = jni::DecodeArtMethod(mid);
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pid_t pid = getpid();
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ALOGD("%s /* TID %d */","mikrom",pid);
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ALOGD("%s [+] JNIEnv->%s","mikrom",funcname);
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ALOGD("%s |- jmethodID :0x%x {%s}","mikrom",method->GetMethodIndex(),method->PrettyMethod().c_str());
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ALOGD("%s |- va_list :%p","mikrom",&vaList);
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uint32_t shorty_len = 0;
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const char* shorty =
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method->GetInterfaceMethodIfProxy(kRuntimePointerSize)->GetShorty(&shorty_len);
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ArgArray arg_array(shorty, shorty_len);
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arg_array.VarArgsShowArg(soa, vaList);
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}
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void ShowVarArgs(const ScopedObjectAccessAlreadyRunnable& soa,
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const char* funcname,
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jmethodID mid,
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va_list valist,
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jobject ret){
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if(!HasShow()){
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return;
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}
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// 输出JNI的参数部分
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ShowVarArgs(soa,funcname,mid,valist);
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// 输出JNI的返回值
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ObjPtr<mirror::Object> receiver =soa.Decode<mirror::Object>(ret);
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if(receiver==nullptr){
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return;
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}
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ObjPtr<mirror::Class> cls=receiver->GetClass();
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if (cls->DescriptorEquals("Ljava/lang/String;")){
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ObjPtr<mirror::String> retStr =soa.Decode<mirror::String>(ret);
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ALOGD("%s |= jstring :%s","mikrom",(const char*)retStr->GetValue());
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}else{
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std::string temp;
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const char* className= cls->GetDescriptor(&temp);
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ALOGD("%s |= jobject :%p {%s}","mikrom",&ret,className);
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}
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}
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```
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很多`JNI`的调用函数除了返回值的处理不同，其他调用部分都是相同的，所以将打印参数部分和打印返回值部分拆分开来，而参数`va_list`的解析，可以直接参考`AOSP`源码中，函数`BuildArgArrayFromVarArgs`对其的处理。实现如下。
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```c++
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void VarArgsShowArg(const ScopedObjectAccessAlreadyRunnable& soa,
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va_list ap)
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REQUIRES_SHARED(Locks::mutator_lock_) {
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std::stringstream ss;
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for (size_t i = 1; i < shorty_len_; ++i) {
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switch (shorty_[i]) {
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case 'Z':
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case 'B':
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case 'C':
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case 'S':
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case 'I':
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ss<<"mikrom"<<" |: jint : "<<va_arg(ap, jint)<<"\n";
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break;
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case 'F':
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ss<<"mikrom"<<" |: jfloat : "<<va_arg(ap, jdouble)<<"\n";
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break;
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case 'L':{
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jobject obj=va_arg(ap, jobject);
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ObjPtr<mirror::Object> receiver =soa.Decode<mirror::Object>(obj);
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if(receiver==nullptr){
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ss<<"mikrom"<<" |: jobject : null\n";
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break;
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}
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ObjPtr<mirror::Class> cls=receiver->GetClass();
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if (cls->DescriptorEquals("Ljava/lang/String;")){
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ObjPtr<mirror::String> argStr =soa.Decode<mirror::String>(obj);
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ss<<"mikrom"<<" |: jstring : "<<(const char*)argStr->GetValue()<<"\n";
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}else{
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ss<<"mikrom"<<" |: jobject : "<<&obj<<"\n";
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}
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break;
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}
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case 'D':
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ss<<"mikrom"<<" |: jdouble : "<<va_arg(ap, jdouble)<<"\n";
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break;
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case 'J':
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ss<<"mikrom"<<" |: jlong : "<<va_arg(ap, jlong)<<"\n";
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break;
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}
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}
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ALOGD("%s",ss.str().c_str());
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}
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```
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到这里案例中使用的相关`JNI`函数处理就添加完成了，编译后刷入测试机。当点击样例中的按钮时，最后输出效果如下所示。
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```
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mikrom enter jni java.lang.String cn.mik.nativedemo.MainActivity.stringFromJNI() 0x74656a77b0
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mikrom /* TID 5465 */
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mikrom [+] JNIEnv->GetMethodID
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mikrom |- jclass :Lcn/mik/nativedemo/MainActivity;
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mikrom |- char* :0x7275d69f1b
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mikrom |: demo
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mikrom |- char* :0x7275d69eef
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mikrom |: (IFLjava/lang/String;)Ljava/lang/String;
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mikrom |= jmethodID :0x277 {java.lang.String cn.mik.nativedemo.MainActivity.demo(int, float, java.lang.String)}
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mikrom /* TID 5465 */
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mikrom [+] JNIEnv->NewStringUTF
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mikrom |- char* : newdemo
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mikrom /* TID 5465 */
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mikrom [+] JNIEnv->CallObjectMethodV
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mikrom |- jmethodID :0x277 {java.lang.String cn.mik.nativedemo.MainActivity.demo(int, float, java.lang.String)}
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mikrom |- va_list :0x7fe0461bb0
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mikrom |: jint : 1
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mikrom |: jfloat : 2
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mikrom |: jstring : newdemo
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mikrom |= jstring :3.0newdemo
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mikrom /* TID 5465 */
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mikrom [+] JNIEnv->GetStringUTFChars
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mikrom |- jboolean* : 0
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mikrom |= char* : 3.0newdemo
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mikrom /* TID 5465 */
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mikrom [+] JNIEnv->NewStringUTF
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mikrom |- char* : 3.0newdemo
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mikrom leave jni java.lang.String cn.mik.nativedemo.MainActivity.stringFromJNI()
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```
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## 12.6 调用栈展示
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经过调整后，打桩函数已经非常接近`JniTrace`的输出效果了，但是还有最后的一点区别是在于`JNI`函数的调用堆栈，不仅仅需要看到函数的参数和返回值，还需要知道是在哪里触发了该函数。而获取调用堆栈地址，在`AOSP`源码是有相关支持的，当应用崩溃时，在`logcat`中能看到详细的堆栈信息。
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### 12.6.1 xUnwind获取调用栈
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`xUnwind`是一个开源工具，该工具将堆栈获取进行了封装，并且有简单的`demo`演示如何获取堆栈。下载地址：`https://github.com/hexhacking/xUnwind.git`。接下来将分析该工具是如何实现的获取堆栈，然后再将其内置到`AOSP`中，在`JNI`函数调用结束时获取堆栈进行输出。
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`xUnwind`提供了三种调用堆栈回溯方案。
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- `CFI (Call Frame Info)`：由安卓系统库提供。
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- `EH (Exception handling GCC extension)`：由编译器提供。
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- `FP (Frame Pointer)`：只支持 `ARM64`。
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其中`CFI`主要针对`java`层调用回溯，`FP`仅支持`ARM64`。根据功能需要，选择`EH`方案进行调用栈回溯。下面看看该工具是如何实现的，首先查看`JNI_OnLoad`的实现。
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```c++
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JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void *reserved) {
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JNIEnv *env;
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jclass cls;
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(void)reserved;
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if (NULL == vm) return JNI_ERR;
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if (JNI_OK != (*vm)->GetEnv(vm, (void **)&env, SAMPLE_JNI_VERSION)) return JNI_ERR;
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if (NULL == env || NULL == *env) return JNI_ERR;
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if (NULL == (cls = (*env)->FindClass(env, SAMPLE_JNI_CLASS_NAME))) return JNI_ERR;
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// 注册对应的函数
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if (0 != (*env)->RegisterNatives(env, cls, sample_jni_methods,
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sizeof(sample_jni_methods) / sizeof(sample_jni_methods[0])))
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return JNI_ERR;
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// 注册信号处理
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sample_signal_register();
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return SAMPLE_JNI_VERSION;
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}
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```
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然后看看`sample_signal_register`对信号进行了什么处理
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```c++
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static void sample_signal_register(void) {
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struct sigaction act;
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// 清空act
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memset(&act, 0, sizeof(act));
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// 填充所有信号
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sigfillset(&act.sa_mask);
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// 删除SIGSEGV信号
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sigdelset(&act.sa_mask, SIGSEGV);
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// 设置信号动作的对应函数
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act.sa_sigaction = sample_sigabrt_handler;
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act.sa_flags = SA_RESTART | SA_SIGINFO | SA_ONSTACK;
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// 设置指定信号的动作
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sigaction(SIGABRT, &act, NULL);
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// 清空act
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memset(&act, 0, sizeof(act));
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// 填充所有信号
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sigfillset(&act.sa_mask);
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// 设置信号动作的对应函数
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act.sa_sigaction = sample_sigsegv_handler;
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act.sa_flags = SA_RESTART | SA_SIGINFO | SA_ONSTACK;
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// 设置指定信号的动作
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sigaction(SIGSEGV, &act, &g_sigsegv_oldact);
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}
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```
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在这个函数中主要是对信号指定了处理函数，`SIGSEGV` 是一种表示段错误的信号，通常意味着进程访问了无法访问的内存地址。
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`SIGABRT` 是一种表示异常终止的信号，通常由调用 `abort()` 函数或 C++ 异常处理程序显式引发。 `abort()` 函数会向进程发送 `SIGABRT` 信号，并导致进程异常终止。
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如果进程接收到 `SIGABRT` 信号，操作系统将其发送给进程，并中断进程的正常执行流程。此时，进程通常会尝试处理该信号并进行恢复或退出。如果进程没有为 `SIGABRT` 信号设置信号处理程序，则默认行为是终止进程。
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接着开始跟踪`EH`的调用栈获取函数`sample_test_eh`的实现。
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```c++
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static void sample_test_eh(JNIEnv *env, jobject thiz, jboolean with_context, jboolean signal_interrupted) {
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(void)env, (void)thiz;
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sample_test(SAMPLE_SOLUTION_EH, JNI_FALSE, with_context, signal_interrupted);
|
||||
}
|
||||
```
|
||||
|
||||
继续查看`sample_test`的实现。
|
||||
|
||||
```c++
|
||||
|
||||
static void sample_test(int solution, jboolean remote_unwind, jboolean with_context,
|
||||
jboolean signal_interrupted) {
|
||||
// 将参数存储到全局变量
|
||||
g_solution = solution;
|
||||
g_remote_unwind = (JNI_TRUE == remote_unwind ? true : false);
|
||||
g_with_context = (JNI_TRUE == with_context ? true : false);
|
||||
g_signal_interrupted = (JNI_TRUE == signal_interrupted ? true : false);
|
||||
|
||||
// 原子请求，为了保证获取到的g_frames_sz没问题
|
||||
__atomic_store_n(&g_frames_sz, 0, __ATOMIC_SEQ_CST);
|
||||
// 触发SIGABRT信号
|
||||
tgkill(getpid(), gettid(), SIGABRT);
|
||||
|
||||
if ((solution == SAMPLE_SOLUTION_FP || solution == SAMPLE_SOLUTION_EH) &&
|
||||
__atomic_load_n(&g_frames_sz, __ATOMIC_SEQ_CST) > 0)
|
||||
// 根据堆栈的地址信息，打印堆栈日志
|
||||
xunwind_frames_log(g_frames, g_frames_sz, SAMPLE_LOG_TAG, SAMPLE_LOG_PRIORITY, NULL);
|
||||
}
|
||||
```
|
||||
|
||||
由于堆栈信息需要通过触发信号后，在信号处理函数中获取，所以这里的参数没办法传过去，这里就将参数放到了全局变量中。然后信号函数执行完毕后，将会填充`g_frames`调用栈的地址信息，最后使用`xunwind_frames_log`函数解析调用栈，最后输出详细的调用栈。
|
||||
|
||||
接下来查看`SIGABRT`信号的处理函数`sample_sigabrt_handler`的实现。
|
||||
|
||||
```java
|
||||
|
||||
static void sample_sigabrt_handler(int signum, siginfo_t *siginfo, void *context) {
|
||||
(void)signum, (void)siginfo;
|
||||
|
||||
if (g_solution == SAMPLE_SOLUTION_FP || g_solution == SAMPLE_SOLUTION_EH) {
|
||||
if (!g_signal_interrupted) {
|
||||
if (g_solution == SAMPLE_SOLUTION_FP) {
|
||||
// FP local unwind
|
||||
...
|
||||
} else if (g_solution == SAMPLE_SOLUTION_EH) {
|
||||
// EH local unwind
|
||||
size_t frames_sz = xunwind_eh_unwind(g_frames, sizeof(g_frames) / sizeof(g_frames[0]),
|
||||
g_with_context ? context : NULL);
|
||||
__atomic_store_n(&g_frames_sz, frames_sz, __ATOMIC_SEQ_CST);
|
||||
}
|
||||
} else {
|
||||
// trigger a segfault, we will do "FP local unwind" in the sigsegv's signal handler
|
||||
...
|
||||
}
|
||||
} else if (!g_remote_unwind) {
|
||||
// CFI local unwind
|
||||
...
|
||||
} else {
|
||||
// CFI remote unwind
|
||||
...
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
`EH`方案是通过`xunwind_eh_unwind`函数获取的调用栈信息，继续查看其具体实现。
|
||||
|
||||
```c++
|
||||
size_t xunwind_eh_unwind(uintptr_t *frames, size_t frames_cap, void *context) {
|
||||
return xu_eh_unwind(frames, frames_cap, context);
|
||||
}
|
||||
|
||||
size_t xu_eh_unwind(uintptr_t *frames, size_t frames_cap, void *context) {
|
||||
if (NULL == frames || 0 == frames_cap) return 0;
|
||||
|
||||
xu_eh_info_t info;
|
||||
info.frames = frames;
|
||||
info.frames_cap = frames_cap;
|
||||
info.frames_sz = 0;
|
||||
info.prev_sp = 0;
|
||||
info.uc = (ucontext_t *)context;
|
||||
|
||||
_Unwind_Backtrace(xu_eh_unwind_cb, &info);
|
||||
|
||||
return info.frames_sz;
|
||||
}
|
||||
```
|
||||
|
||||
`_Unwind_Backtrace`函数用于获取当前线程的调用堆栈信息。它使用`C++`异常处理机制中的`unwind`操作来实现，因此只能在支持`C++`异常处理的系统上使用。到这里就知道堆栈获取的来源了。但是这里的信息和真实看的还是有一定差距，继续看看`xunwind_frames_log`是如何对其进行转换展示的。
|
||||
|
||||
```c++
|
||||
void xunwind_frames_log(uintptr_t *frames, size_t frames_sz, const char *logtag, android_LogPriority priority,
|
||||
const char *prefix) {
|
||||
if (priority < ANDROID_LOG_VERBOSE || ANDROID_LOG_FATAL < priority) return;
|
||||
|
||||
xu_printer_t printer;
|
||||
xu_printer_init_log(&printer, logtag, priority);
|
||||
|
||||
xu_formatter_print(frames, frames_sz, prefix, &printer);
|
||||
}
|
||||
```
|
||||
|
||||
继续跟踪`xu_formatter_print`的实现。
|
||||
|
||||
```c++
|
||||
|
||||
void xu_formatter_print(uintptr_t *frames, size_t frames_sz, const char *prefix, xu_printer_t *printer) {
|
||||
if (NULL == frames || 0 == frames_sz) return;
|
||||
|
||||
if (NULL == prefix) prefix = "";
|
||||
|
||||
void *cache = NULL;
|
||||
xdl_info_t info;
|
||||
for (size_t i = 0; i < frames_sz; i++) {
|
||||
memset(&info, 0, sizeof(xdl_info_t));
|
||||
int r = 0;
|
||||
|
||||
if (0 != frames[i]) {
|
||||
// 根据调用栈地址获取动态库的信息
|
||||
r = xdl_addr((void *)(frames[i]), &info, &cache);
|
||||
|
||||
// 如果查找到的动态库的起始地址大于这条调用栈信息的地址，则从maps中重新找动态库信息
|
||||
char buf[512];
|
||||
if (0 == r || (uintptr_t)info.dli_fbase > frames[i])
|
||||
r = xu_formatter_maps_addr(frames[i], &info, buf, sizeof(buf));
|
||||
}
|
||||
|
||||
// 输出打印
|
||||
if (0 == r || (uintptr_t)info.dli_fbase > frames[i])
|
||||
xu_printer_append_format(printer, XU_FORMATTER_PREFIX "<unknown>\n", prefix, i, frames[i]);
|
||||
else if (NULL == info.dli_fname || '\0' == info.dli_fname[0])
|
||||
xu_printer_append_format(printer, XU_FORMATTER_PREFIX "<anonymous:" XU_FORMATTER_ADDR ">\n", prefix, i,
|
||||
frames[i] - (uintptr_t)info.dli_fbase, (uintptr_t)info.dli_fbase);
|
||||
else if (NULL == info.dli_sname || '\0' == info.dli_sname[0])
|
||||
xu_printer_append_format(printer, XU_FORMATTER_PREFIX "%s\n", prefix, i,
|
||||
frames[i] - (uintptr_t)info.dli_fbase, info.dli_fname);
|
||||
else if (0 == (uintptr_t)info.dli_saddr || (uintptr_t)info.dli_saddr > frames[i])
|
||||
xu_printer_append_format(printer, XU_FORMATTER_PREFIX "%s (%s)\n", prefix, i,
|
||||
frames[i] - (uintptr_t)info.dli_fbase, info.dli_fname, info.dli_sname);
|
||||
else
|
||||
xu_printer_append_format(printer, XU_FORMATTER_PREFIX "%s (%s+%" PRIuPTR ")\n", prefix, i,
|
||||
frames[i] - (uintptr_t)info.dli_fbase, info.dli_fname, info.dli_sname,
|
||||
frames[i] - (uintptr_t)info.dli_saddr);
|
||||
}
|
||||
xdl_addr_clean(&cache);
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
继续查看是如何输出的。
|
||||
|
||||
```c++
|
||||
void xu_printer_append_format(xu_printer_t *self, const char *format, ...) {
|
||||
va_list ap;
|
||||
va_start(ap, format);
|
||||
|
||||
char tmpbuf[1024];
|
||||
#pragma clang diagnostic push
|
||||
#pragma clang diagnostic ignored "-Wformat-nonliteral"
|
||||
vsnprintf(tmpbuf, sizeof(tmpbuf), format, ap);
|
||||
#pragma clang diagnostic pop
|
||||
|
||||
va_end(ap);
|
||||
|
||||
xu_printer_append_string(self, tmpbuf);
|
||||
}
|
||||
|
||||
|
||||
void xu_printer_append_string(xu_printer_t *self, const char *str) {
|
||||
if (XU_PRINTER_TYPE_LOG == self->type) {
|
||||
__android_log_print(self->data.log.priority, self->data.log.logtag, "%s", str);
|
||||
} else if (XU_PRINTER_TYPE_DUMP == self->type) {
|
||||
size_t len = strlen(str);
|
||||
if (len > 0) {
|
||||
xu_util_write(self->data.dump.fd, str, len);
|
||||
if ('\n' != str[len - 1]) xu_util_write(self->data.dump.fd, "\n", 1);
|
||||
}
|
||||
} else if (XU_PRINTER_TYPE_GET == self->type) {
|
||||
size_t len = strlen(str);
|
||||
if (len > 0) {
|
||||
xu_printer_string_append_to_buf(self, str);
|
||||
if ('\n' != str[len - 1]) xu_printer_string_append_to_buf(self, "\n");
|
||||
}
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
到了最后输出的部分可以看到，支持三种方式输出，在调用时，根据不同的需求来选择合适的输出方式。
|
||||
|
||||
* `XU_PRINTER_TYPE_LOG` 直接`logcat`输出信息
|
||||
* `XU_PRINTER_TYPE_DUMP `将堆栈信息写入到指定描述符
|
||||
* `XU_PRINTER_TYPE_GET` 返回堆栈信息的字符串。
|
||||
|
||||
了解完整个实现原理后，最后看看其输出效果。`EH`方案的调用栈输出如下。
|
||||
|
||||
```
|
||||
I/xunwind_tag: >>> EH: Local Process (pid: 6713), Current Thread (tid: 6713) <<<
|
||||
I/xunwind_tag: #00 pc 00000000000093a4 /data/app/~~H824r8gCTUibCXd65QZfPw==/io.github.hexhacking.xunwind.sample-1gWu3tav0VA7-qGsCc7nZQ==/lib/arm64/libxunwind.so (xunwind_eh_unwind+72)
|
||||
I/xunwind_tag: #01 pc 00000000000014a8 /data/app/~~H824r8gCTUibCXd65QZfPw==/io.github.hexhacking.xunwind.sample-1gWu3tav0VA7-qGsCc7nZQ==/lib/arm64/libsample.so
|
||||
I/xunwind_tag: #02 pc 00000000000008b0 [vdso] (__kernel_rt_sigreturn+0)
|
||||
I/xunwind_tag: #03 pc 000000000009e598 /apex/com.android.runtime/lib64/bionic/libc.so (tgkill+8)
|
||||
I/xunwind_tag: #04 pc 0000000000001320 /data/app/~~H824r8gCTUibCXd65QZfPw==/io.github.hexhacking.xunwind.sample-1gWu3tav0VA7-qGsCc7nZQ==/lib/arm64/libsample.so
|
||||
I/xunwind_tag: #05 pc 0000000000001254 /data/app/~~H824r8gCTUibCXd65QZfPw==/io.github.hexhacking.xunwind.sample-1gWu3tav0VA7-qGsCc7nZQ==/lib/arm64/libsample.so
|
||||
I/xunwind_tag: #06 pc 0000000000222248 /apex/com.android.art/lib64/libart.so (art_quick_generic_jni_trampoline+152)
|
||||
I/xunwind_tag: #07 pc 0000000000218bec /apex/com.android.art/lib64/libart.so (art_quick_invoke_static_stub+572)
|
||||
I/xunwind_tag: #08 pc 0000000000290300 /apex/com.android.art/lib64/libart.so (_ZN3art9ArtMethod6InvokeEPNS_6ThreadEPjjPNS_6JValueEPKc+536)
|
||||
I/xunwind_tag: #09 pc 00000000003f09e4 /apex/com.android.art/lib64/libart.so (_ZN3art11interpreter34ArtInterpreterToCompiledCodeBridgeEPNS_6ThreadEPNS_9ArtMethodEPNS_11ShadowFrameEtPNS_6JValueE+404)
|
||||
I/xunwind_tag: #10 pc 00000000003eb858 /apex/com.android.art/lib64/libart.so (_ZN3art11interpreter6DoCallILb0ELb0EEEbPNS_9ArtMethodEPNS_6ThreadERNS_11ShadowFrameEPKNS_11InstructionEtPNS_6JValueE+808)
|
||||
I/xunwind_tag: #11 pc 00000000007658d0 /apex/com.android.art/lib64/libart.so (MterpInvokeStatic+984)
|
||||
I/xunwind_tag: #12 pc 0000000000203998 /apex/com.android.art/lib64/libart.so (mterp_op_invoke_static+24)
|
||||
I/xunwind_tag: #13 pc 00000000003e3688 /apex/com.android.art/lib64/libart.so (_ZN3art11interpreterL7ExecuteEPNS_6ThreadERKNS_20CodeItemDataAccessorERNS_11ShadowFrameENS_6JValueEbb+348)
|
||||
I/xunwind_tag: #14 pc 000000000074920c /apex/com.android.art/lib64/libart.so (artQuickToInterpreterBridge+780)
|
||||
I/xunwind_tag: #15 pc 000000000022237c /apex/com.android.art/lib64/libart.so (art_quick_to_interpreter_bridge+92)
|
||||
I/xunwind_tag: #16 pc 000000000021160c /apex/com.android.art/lib64/libart.so (nterp_helper+156)
|
||||
I/xunwind_tag: #17 pc 0000000000218968 /apex/com.android.art/lib64/libart.so (art_quick_invoke_stub+552)
|
||||
I/xunwind_tag: #18 pc 00000000002902d4 /apex/com.android.art/lib64/libart.so (_ZN3art9ArtMethod6InvokeEPNS_6ThreadEPjjPNS_6JValueEPKc+492)
|
||||
I/xunwind_tag: #19 pc 000000000062ba5c /apex/com.android.art/lib64/libart.so (_ZN3art12InvokeMethodILNS_11PointerSizeE8EEEP8_jobjectRKNS_33ScopedObjectAccessAlreadyRunnableES3_S3_S3_m+1388)
|
||||
I/xunwind_tag: #20 pc 000000000059d2f8 /apex/com.android.art/lib64/libart.so (_ZN3artL13Method_invokeEP7_JNIEnvP8_jobjectS3_P13_jobjectArray+56)
|
||||
I/xunwind_tag: #21 pc 0000000000222248 /apex/com.android.art/lib64/libart.so (art_quick_generic_jni_trampoline+152)
|
||||
I/xunwind_tag: #22 pc 0000000000212524 /apex/com.android.art/lib64/libart.so (nterp_helper+4020)
|
||||
I/xunwind_tag: #23 pc 00000000002132e8 /apex/com.android.art/lib64/libart.so (nterp_helper+7544)
|
||||
I/xunwind_tag: #24 pc 00000000002124c8 /apex/com.android.art/lib64/libart.so (nterp_helper+3928)
|
||||
I/xunwind_tag: #25 pc 00000000002124c8 /apex/com.android.art/lib64/libart.so (nterp_helper+3928)
|
||||
I/xunwind_tag: #26 pc 00000000002115a8 /apex/com.android.art/lib64/libart.so (nterp_helper+56)
|
||||
I/xunwind_tag: #27 pc 00000000002132e8 /apex/com.android.art/lib64/libart.so (nterp_helper+7544)
|
||||
I/xunwind_tag: #28 pc 00000000002115a8 /apex/com.android.art/lib64/libart.so (nterp_helper+56)
|
||||
I/xunwind_tag: #29 pc 00000000002124c8 /apex/com.android.art/lib64/libart.so (nterp_helper+3928)
|
||||
I/xunwind_tag: #30 pc 00000000002115a8 /apex/com.android.art/lib64/libart.so (nterp_helper+56)
|
||||
I/xunwind_tag: #31 pc 00000000002115a8 /apex/com.android.art/lib64/libart.so (nterp_helper+56)
|
||||
I/xunwind_tag: #32 pc 0000000000218bec /apex/com.android.art/lib64/libart.so (art_quick_invoke_static_stub+572)
|
||||
I/xunwind_tag: #33 pc 0000000000290300 /apex/com.android.art/lib64/libart.so (_ZN3art9ArtMethod6InvokeEPNS_6ThreadEPjjPNS_6JValueEPKc+536)
|
||||
I/xunwind_tag: #34 pc 000000000062ba5c /apex/com.android.art/lib64/libart.so (_ZN3art12InvokeMethodILNS_11PointerSizeE8EEEP8_jobjectRKNS_33ScopedObjectAccessAlreadyRunnableES3_S3_S3_m+1388)
|
||||
I/xunwind_tag: #35 pc 000000000059d2f8 /apex/com.android.art/lib64/libart.so (_ZN3artL13Method_invokeEP7_JNIEnvP8_jobjectS3_P13_jobjectArray+56)
|
||||
I/xunwind_tag: #36 pc 0000000000222248 /apex/com.android.art/lib64/libart.so (art_quick_generic_jni_trampoline+152)
|
||||
I/xunwind_tag: #37 pc 0000000000212524 /apex/com.android.art/lib64/libart.so (nterp_helper+4020)
|
||||
I/xunwind_tag: #38 pc 00000000002132e8 /apex/com.android.art/lib64/libart.so (nterp_helper+7544)
|
||||
I/xunwind_tag: #39 pc 0000000000218bec /apex/com.android.art/lib64/libart.so (art_quick_invoke_static_stub+572)
|
||||
I/xunwind_tag: #40 pc 0000000000290300 /apex/com.android.art/lib64/libart.so (_ZN3art9ArtMethod6InvokeEPNS_6ThreadEPjjPNS_6JValueEPKc+536)
|
||||
I/xunwind_tag: #41 pc 000000000062c1b4 /apex/com.android.art/lib64/libart.so (_ZN3art17InvokeWithVarArgsIPNS_9ArtMethodEEENS_6JValueERKNS_33ScopedObjectAccessAlreadyRunnableEP8_jobjectT_St9__va_list+452)
|
||||
I/xunwind_tag: #42 pc 000000000062c678 /apex/com.android.art/lib64/libart.so (_ZN3art17InvokeWithVarArgsIP10_jmethodIDEENS_6JValueERKNS_33ScopedObjectAccessAlreadyRunnableEP8_jobjectT_St9__va_list+96)
|
||||
I/xunwind_tag: #43 pc 0000000000507c68 /apex/com.android.art/lib64/libart.so (_ZN3art3JNIILb1EE21CallStaticVoidMethodVEP7_JNIEnvP7_jclassP10_jmethodIDSt9__va_list+620)
|
||||
I/xunwind_tag: #44 pc 00000000000aeac8 /system/lib64/libandroid_runtime.so (_ZN7_JNIEnv20CallStaticVoidMethodEP7_jclassP10_jmethodIDz+124)
|
||||
I/xunwind_tag: #45 pc 00000000000ba060 /system/lib64/libandroid_runtime.so (_ZN7android14AndroidRuntime5startEPKcRKNS_6VectorINS_7String8EEEb+840)
|
||||
I/xunwind_tag: #46 pc 00000000000025a8 /system/bin/app_process64 (main+1364)
|
||||
I/xunwind_tag: #47 pc 00000000000498cc /apex/com.android.runtime/lib64/bionic/libc.so (__libc_init+100)
|
||||
I/xunwind_tag: >>> finished <<<
|
||||
```
|
||||
|
||||
### 12.6.2 优化调用栈样例
|
||||
|
||||
尽管在该工具中的样例可以直接使用，但是想要将其内置到`AOSP`中还需要将其进行优化处理，简单写一个模拟注入流程的样例，对样例做出以下调整。
|
||||
|
||||
* 去掉非`EH`获取方案的代码部分
|
||||
* 优化获取调用栈信息的代码，让其结果仅输出想要关注的目标动态库的调用栈。
|
||||
* 直接输出日志调整为返回调用栈字符串。
|
||||
|
||||
新建`native`的项目，将`xUnwind`的样例`apk`解压后，取出其`lib`目录中的依赖动态库，将其复制到新项目的`libs`目录中，如下图。
|
||||
|
||||
|
||||
|
||||
### 12.6.3 内置获取调用栈
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user