Load binary file into flat memory and then jump into it in protected mode

I am trying to build my own hobby operating system and is trying to create load and run flat binary file into the heap and then execute it in protected mode?

I have tried creating a pointer and then copied a 45 bytes function to its address and then jump into it, but it gave interrupt 13 (General Protection fault)

Here is my code https://github.com/s0ubhik/myos

void aa(){
    printkc("H OH O H", 0xb);
}


void kernel_main(unsigned long kernel_stack){
    ...

    unsigned char* m = (unsigned char*) &aa;
    unsigned char* b = (unsigned char*) 0x600000;

    for (int i=0; i < 45; i++){
        print_hex(m[i], 2);
        b[i] = m[i];
        printk(" ");
    }
    printk("\n");
    for (int i=0; i < 45; i++){
        print_hex(b[i], 2);
        printk(" ");
    }
    printk("\n");

    void (*func_ptr)(void) = (void (*)(void))0x600000;
    func_ptr();

    ....
}

Look at this section where I load the contents of function aa into the heap 0x600000 and then try to jump to it