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第六章更新内容

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@ -552,6 +552,121 @@ rom.nativedem: [ROM] Library found address: 0x7a62102000
rom.nativedem: [ROM] ClassLinker::RegisterNative java.lang.String cn.rom.nativedemo.MainActivity.stringFromJNI() native_ptr:0x7a621106e8 method_idx:0x277 offset:0xe6e8
```
​ 尽管这里已经成功获取到了偏移地址，但是这里并不能确定拿到的end地址是正确的，对于end地址的计算方式，是获取最后一个段的地址+偏移+段大小计算出来的。下面简单修改一下函数对于段进行详细打印。
```c++
int dl_iterate_callback(struct dl_phdr_info* info, size_t , void* entry) {
void* endptr= (void*)(info->dlpi_addr + info->dlpi_phdr[info->dlpi_phnum - 1].p_vaddr + info->dlpi_phdr[info->dlpi_phnum - 1].p_memsz);
LOGD("mikrom name:%s base:%p end:%p\n",info->dlpi_name,(void*)info->dlpi_addr,endptr);
for (int j = 0; j < info->dlpi_phnum; j++) {
LOGD("mikrom %2d: [%14p; memsz:%7lx] flags: 0x%x; ", j,
(void *) (info->dlpi_addr + info->dlpi_phdr[j].p_vaddr),
info->dlpi_phdr[j].p_memsz,
info->dlpi_phdr[j].p_flags);
}
return 0;
}
```
​ 输出的结果如下所示，根据base和end的大小，可以看出来该结束地址是错误的。
```
mikrom name:/system/bin/linker64 base:0x7b21c17000 end:0x7b21c17290
mikrom 0: [ 0x7b21c17040; memsz: 230] flags: 0x4;
mikrom 1: [ 0x7b21c17000; memsz: 367b4] flags: 0x4;
mikrom 2: [ 0x7b21c4e000; memsz: e2940] flags: 0x5;
mikrom 3: [ 0x7b21d31000; memsz: 7ca0] flags: 0x6;
mikrom 4: [ 0x7b21d39ca0; memsz: c0f0] flags: 0x6;
mikrom 5: [ 0x7b21d381a8; memsz: 120] flags: 0x6;
mikrom 6: [ 0x7b21d31000; memsz: 8000] flags: 0x4;
mikrom 7: [ 0x7b21c2eacc; memsz: 5e14] flags: 0x4;
mikrom 8: [ 0x7b21c17000; memsz: 0] flags: 0x6;
mikrom 9: [ 0x7b21c17270; memsz: 20] flags: 0x4;
```
​ 接下来查看maps中的映射动态库的地址，印证计算的结果是否正确。
```
7b21c17000-7b21c4e000 r--p 00000000 07:48 16 /apex/com.android.runtime/bin/linker64
7b21c4e000-7b21d31000 r-xp 00037000 07:48 16 /apex/com.android.runtime/bin/linker64
7b21d31000-7b21d39000 r--p 0011a000 07:48 16 /apex/com.android.runtime/bin/linker64
7b21d39000-7b21d3b000 rw-p 00121000 07:48 16 /apex/com.android.runtime/bin/linker64
```
​ 为什么会出现这种错误呢，根据上面的段详细打印，以及前面的计算方式，是使用最后一个段的地址+段大小，得到的结束地址，也就是`0x7b21c17270+0x20=end(0x7b21c17290)`，所以这里需要将逻辑进行优化，应该取段中，最大的地址+段大小=end。同时优化代码，将动态库名称一起返回展示。代码如下。
```c++
// add mikrom
typedef struct{
uintptr_t addr;
uintptr_t baseAddr;
std::string moduleName="";
}ModuleStruck;
int dl_iterate_callback(struct dl_phdr_info* info, size_t , void* entry) {
ModuleStruck* mod=reinterpret_cast<ModuleStruck*>(entry);
if(strlen(mod->moduleName.c_str())>0){
return 0;
}
uintptr_t addr = mod->addr;
// void* endptr= (void*)(info->dlpi_addr + info->dlpi_phdr[info->dlpi_phnum - 1].p_vaddr + info->dlpi_phdr[info->dlpi_phnum - 1].p_memsz);
uint64_t maxAddr=0;
uint64_t maxMemsz=0;
for (int j = 0; j < info->dlpi_phnum; j++) {
if((info->dlpi_addr + info->dlpi_phdr[j].p_vaddr)>maxAddr){
maxAddr=info->dlpi_addr + info->dlpi_phdr[j].p_vaddr;
maxMemsz=info->dlpi_phdr[j].p_memsz;
}
}
uintptr_t end=maxAddr+maxMemsz;
// ALOGD("mikrom native:%p name:%s base:%p end:%p\n", (void*)addr,info->dlpi_name,(void*)info->dlpi_addr,(void*)end);
if(addr >= info->dlpi_addr && addr<=end){
// ALOGD("mikrom Library found native:%p base:%p\n\n",(void*)addr,(void*)info->dlpi_addr);
mod->baseAddr=info->dlpi_addr;
mod->moduleName=info->dlpi_name;
}
return 0;
}
void FindLibraryBaseAddress(ModuleStruck* entry) {
dl_iterate_phdr(dl_iterate_callback, entry);
}
// addend
const void* ClassLinker::RegisterNative(
Thread* self, ArtMethod* method, const void* native_method) {
...
if (method->IsCriticalNative()) {
...
} else {
method->SetEntryPointFromJni(new_native_method);
if(Runtime::Current()->GetConfigItem().isRegisterNativePrint){
void * native_ptr=new_native_method;
ModuleStruck mod;
mod.addr=(uintptr_t)native_ptr;
FindLibraryBaseAddress(&mod);
uintptr_t base_addr=mod.baseAddr;
uintptr_t native_data = reinterpret_cast<uintptr_t>(native_ptr);
uintptr_t base_data = reinterpret_cast<uintptr_t>(base_addr);
uintptr_t offset=native_data-base_data;
ALOGD("mikrom ClassLinker::RegisterNative %s native_ptr:%p method_idx:0x%x offset:%p module_name:%s",method->PrettyMethod().c_str(),new_native_method,method->GetMethodIndex(),(void*)offset,mod.moduleName.c_str());
}
}
return new_native_method;
}
```
​ 最终在实际应用中效果展示如下。
```
2023-08-01 15:24:08.816 5468-5659 com.UCMobile com.UCMobile D mikrom ClassLinker::RegisterNative void com.alibaba.mbg.unet.internal.UNetRequestJni.nativeSetExtraInfo(long, int, java.lang.String[]) native_ptr:0xb60d7ae9 method_idx:0x11 offset:0x108ae9 module_name:/data/app/~~JHAIRSSsk6jBdgjb90EHSQ==/com.UCMobile-aUSjEzsqxD6w8l-eJW7kWw==/lib/arm/libunet.so
2023-08-01 15:24:08.816 5468-5659 com.UCMobile com.UCMobile D mikrom ClassLinker::RegisterNative void com.alibaba.mbg.unet.internal.UNetRequestJni.nativeAddLogScene(long, java.lang.String, java.lang.String, java.lang.String) native_ptr:0xb60d7c95 method_idx:0x1 offset:0x108c95 module_name:/data/app/~~JHAIRSSsk6jBdgjb90EHSQ==/com.UCMobile-aUSjEzsqxD6w8l-eJW7kWw==/lib/arm/libunet.so
2023-08-01 15:24:08.816 5468-5659 com.UCMobile com.UCMobile D mikrom ClassLinker::RegisterNative void com.alibaba.mbg.unet.internal.UNetRequestJni.nativeSetEnableDeepPrefetch(long, boolean) native_ptr:0xb60d7d5d method_idx:0x10 offset:0x108d5d module_name:/data/app/~~JHAIRSSsk6jBdgjb90EHSQ==/com.UCMobile-aUSjEzsqxD6w8l-eJW7kWw==/lib/arm/libunet.so
2023-08-01 15:24:08.816 5468-5659 com.UCMobile com.UCMobile D mikrom ClassLinker::RegisterNative void com.alibaba.mbg.unet.internal.UNetRequestStatJni.nativeDestroy(long) native_ptr:0xb60d8895 method_idx:0x2 offset:0x109895 module_name:/data/app/~~JHAIRSSsk6jBdgjb90EHSQ==/com.UCMobile-aUSjEzsqxD6w8l-eJW7kWw==/lib/arm/libunet.so
```
## 6.4 自定义系统服务