代码还原的技术: Unidbg hook_add_new实现条件断点(二)

extern "C" JNIEXPORT jstring JNICALL
Java_com_fenfei_app_floatdemo_MainActivity_stringFromJNI(
        JNIEnv* env,
        jobject Obj, jdouble value) {
    std::string hello = "Hello from C++";
    double p=3.14159;
    double s,v,rc;
    for(int i=0 ; i< 10; i++){
        hello +="\n";
        v = 2*p* (value + i);
        s = p * (value + i) * (value + i);
        rc = v+s;
        hello += std::to_string(rc);
    }
    return env->NewStringUTF(hello.c_str());
}

Hello from C++
150.796320
197.920170
251.327200
311.017410
376.990800
449.247370
527.787120
612.610050
703.716160
801.105450

// com/fenfei/test/runfloatdemo.java
analyseHookA = new FFCodehook(emulator);
emulator.getBackend().hook_add_new(analyseHookA, module.base + 0x127D8, module.base + 0x127D8, emulator);
// com/fenfei/test/ffcodehook.java
public class FFCodehook implements CodeHook {
    private final Emulator<?> emulator;
    public FFCodehook(Emulator<?> emulator) {
        super();
        this.emulator = emulator;
    }
    private Unicorn.UnHook unHook;
    @Override
    public void onAttach(Unicorn.UnHook unHook) {
        if (this.unHook != null) {
            throw new IllegalStateException();
        }
        this.unHook = unHook;
    }
    @Override
    public void detach() {
        if (unHook != null) {
            unHook.unhook();
            unHook = null;
        }
    }
    private static BigInteger newBigInteger(byte[] data) {
        if (data.length != 16) {
            throw new IllegalStateException("data.length=" + data.length);
        }
        byte[] copy = Arrays.copyOf(data, data.length);
        for (int i = 0; i < 8; i++) {
            byte b = copy[i];
            copy[i] = copy[15 - i];
            copy[15 - i] = b;
        }
        byte[] bytes = new byte[copy.length + 1];
        System.arraycopy(copy, 0, bytes, 1, copy.length); // makePositive
        return new BigInteger(bytes);
    }
    @Override
    public void hook(Backend backend, long address, int size, Object user) {
        try {
            if (address == 0x400127d8) {
                byte[] data = backend.reg_read_vector(Arm64Const.UC_ARM64_REG_Q0);
                if (data != null) {
                    String strShow = String.format(Locale.US, " Q0=0x%s%s", newBigInteger(data).toString(16), Utils.decodeVectorRegister(data));
                    System.out.println("##### value  " + strShow);
                }
            }
        } catch (BackendException e) {
            throw new IllegalStateException(e);
        }
    }
}

##### value   Q0=0x4062d97b7414a4d2(150.79631999999998)
##### value   Q0=0x4068bd72085b1854(197.92016999999998)
##### value   Q0=0x406f6a786c22680a(251.3272)
##### value   Q0=0x407370474fb549fa(311.01741000000004)
##### value   Q0=0x40778fda5119ce07(376.9908)
##### value   Q0=0x407c13f53a3ec02f(449.24737)
##### value   Q0=0x40807e4c05921038(527.78712)
##### value   Q0=0x408324e161e4f765(612.6100499999999)
##### value   Q0=0x4085fdbab21815a0(703.71616)
##### value   Q0=0x408908d7f62b6ae8(801.10545)

double bOutD = bytes2Double(data);
if(bOutD == 449.247370){
  Debugger MyDbg = emulator.attach(DebuggerType.CONSOLE);
    MyDbg.addBreakPoint(0x400127dc);
}

final double THRESHOLD = .0001;
double bOutD = bytes2Double(data);
if (Math.abs(bOutD - 449.247370 ) < THRESHOLD) {
  ...
}