Calling function from address doesn't work

When calling a function from a memory address directly, several factors come into play, and it's essential to ensure that the process is set up correctly. Here are some common issues that might cause calling a function from an address not to work:

1. Function Signature:
   Ensure that you are calling the function with the correct signature (parameter types and return type) and that the calling convention matches. If the function is using a specific calling convention (e.g., cdecl, stdcall, etc.), you must adhere to it when making the call.

2. Memory Protection:
   Ensure that the memory region where the function resides has the appropriate protection flags to allow execution. Memory regions with read-only or no-execution protection will prevent you from executing code from that memory.

3. Memory Alignment:
   Check the memory alignment of the function. Some architectures have strict alignment requirements for function calls, and failure to meet these requirements can lead to unexpected behavior.

4. Calling from Correct Address:
   Make sure that you are calling the function from the correct memory address. Ensure that the address points to the entry point of the function.

5. Function Context:
   When calling a function directly from an address, you need to ensure that the function has all the required context and environment set up correctly. This includes setting up function arguments and any required context for the function to work correctly.

6. Address Calculation:
   If the function address is calculated dynamically, double-check that the calculation is correct and points to the correct function.

7. Memory Permissions:
   Ensure that the memory region from which you are trying to call the function has the necessary read and execute permissions.

8. Platform-Specific Considerations:
   Be aware of platform-specific differences and requirements when calling functions directly from memory. Different platforms may have different calling conventions and memory layout.

9. Debugging and Logging:
   Implement debug logging and print relevant information during the process to help identify any issues.

Keep in mind that calling functions directly from memory can be tricky and is typically an advanced technique used in low-level programming scenarios. It might involve platform-specific or architecture-specific considerations. If possible, prefer to call functions using standard function calls, which are safer and easier to manage.

If you are working with dynamically loaded libraries or external functions, consider using standard dynamic linking techniques provided by the operating system and programming languages. These methods handle memory protection, calling conventions, and other considerations automatically, making your code more portable and maintainable.