great project, how to pass parameters, get function return?

[abbuaus]

great project, how to pass parameters, get function return? i am a beginner

[reveny]

Generally speaking, this is how function calls work in the project:

1. Get the address of the target function. (in this case dlopen).
2. Define the parameters as follows: long parameters[2]; //2 is the amount of parameters
3. Set the parameters: dlopen has 2 parameters: dlopen(const char* path, int mode);

   parameters[0] = (uintptr_t) remoteMmapAddr;
   parameters[1] = RTLD_NOW | RTLD_GLOBAL;

   Note that we are passing a address to a string as the first argument, this was done by allocating memory and then writing a string to it, in this case it is the dlopen path.

4. Call the function with ptrace call:

   //                   process id,   address,  parameters, amount of parameters, regs
   if (ptrace_call(pid, (uintptr_t) dlopen_addr, parameters, 2, &currentRegs) == -1) {
       LOGE("Call dlopen Failed");
       return -1;
   }

5. Get the return value: The return value will be saved in the register that can be acquired with ptrace_getret.

   void *remoteModuleAddr = (void *)ptrace_getret(&currentRegs);
   LOGI("ptrace_call dlopen success, Remote module Address: 0x%lx", (long)remoteModuleAddr);

And that is it. That is how you can call a function with this project. There is currently no way to pass parameters and get the return value through the UI, you need to implement that on your own :)