Multiple definitions when making kernel module over multiple source files - c

Question

I think the problem is having one header file that has all items that my source files needs, but how do I fix this? Is it possible to use one or must I split them up with their own includes functionalities.
I not sure what wrong with my .h file that I'm including in all my source files. I read that the problem is each source file is compiling separately with this .h file and when linking all source files together, the compile finds there are multiple definitions even though I have a include guard.
How can I go about this? There's prototype.h that includes all my function prototypes, includes, extern variables, and structs. I have a few source files that all need some portion of this .h file.
My make file is as follows
TARGET = betty
obj-m := $(TARGET).o
betty-objs := main.o helpers.o syscall_overrides.o
KDIR := /lib/modules/$(shell uname -r)/build
PWD := $(shell pwd)
default:
$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules
clean:
$(RM) .*.cmd *.o *.ko -r .tmp*
And the error message (a portion of them) that it gives is:
/home/admin/Dropbox/COMP3000/FinalModule/helpers.o:(.bss+0x4): multiple definition of `clean_sys_mkdir'
/home/admin/Dropbox/COMP3000/FinalModule/main.o:(.bss+0x0): first defined here
/home/admin/Dropbox/COMP3000/FinalModule/helpers.o:(.bss+0x8): multiple definition of `clean_sys_execve'
/home/admin/Dropbox/COMP3000/FinalModule/main.o:(.bss+0x4): first defined here
/home/admin/Dropbox/COMP3000/FinalModule/helpers.o:(.bss+0xc): multiple definition of `clean_getdents64_syscall'
Code:
main.c
#define MODULE_NAME "Betty"
#include "prototypes.h"
extern unsigned long **syscall_table;
static int __init init(void)
{
...
}
static void __exit shutdown(void)
{
...
}
module_init(init);
module_exit(shutdown);
MODULE_LICENSE("..");
MODULE_AUTHOR("..");
MODULE_DESCRIPTION("..");
prototype.h
#ifndef PROTOTYPE_H
#define PROTOTYPE_H
#include <linux/module.h> // mandatory kernel module
#include <linux/kernel.h> // KERN_INFO
#include <linux/init.h> // __init and __exit
#include <asm/unistd.h> // __NR syscall nums
#include <linux/printk.h>
#include <linux/tty.h> // tty_struct
#include <linux/tty_driver.h>// write (already included by tty.h)
#include <linux/sched.h> // current
#include <linux/random.h> // get_random_bytes
#include <linux/syscalls.h> // from sys_execve asmlinkage
#include <linux/dirent.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/slab.h> // kmalloc()
#include <linux/time.h> // time
#include <linux/rtc.h> // rtc_time_to_tm
/*
Function prototypes for both original and custom syscalls that Betty uses
*/
asmlinkage long (*clean_sys_mkdir)(const char __user *pathname, umode_t mode);
asmlinkage long (*clean_sys_execve)(const char __user *filename,
const char __user *const __user *argv,
const char __user *const __user *envp);
asmlinkage long (*clean_getdents64_syscall) (unsigned int fd,
struct linux_dirent64 __user * dirent,
unsigned int count);
static void find_process_id_to_hide(char* process_nm);
extern unsigned long **syscall_table;
#endif
helpers.c
#include "prototypes.h"
extern unsigned long **syscall_table; // extern variable
... just functions in this one defined in prototype.h