linux/init.h: No such file or directory

Question

I'm trying to build a kernel module for my class, and I'm getting a massive wall of errors, but at the top of said wall is the infamous 'No such file or directory' error. It seems to be the root of the problem. This not only seems to affect init.h, but also module.h and kernel.h. The first three lines of the program go as follows:

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>

I've looked around and tried other paths for where these files ought to be when browsing similar issues, but nothing has worked thus far. The strangest part is that I used this module already; I was provided starter code that had this at the top (I didn't change anything) and it didn't give me that error. Although, obviously the code after is different, but this seems to be the biggest problem at the moment.

The full code is as follows:

#include </usr/include/linux/init.h>
#include </usr/include/linux/module.h>
#include </usr/include/linux/kernel.h>

/* This function is called when the module is loaded. */
int simple_init(void)
{
    printk(KERN_INFO "Loading Module\n");
    static LIST_HEAD(birthday_list)
    struct birthday{
        int day;
        int month;
        int year;
        struct list_head list;
    };
    struct birthday *ptr, *next;
    struct birthday *bob;
    struct birthday *judy;
    struct birthday *josh;
    struct birthday *lana;
    struct birthday *jan;

    bob = kmalloc(sizeof(*bob), GFP_KERNEL);
    bob -> day = 17;
    bob -> month = 1;
    bob -> year = 1990;
    INIT_LIST_HEAD(&bob -> list);

    ...

    list_add_tail(bob -> list, &birthday_list);
    list_add_tail(judy -> list, &birthday_list);
    list_add_tail(josh -> list, &birthday_list);
    list_add_tail(lana -> list, &birthday_list);
    list_add_tail(jan -> list, &birthday_list);

    struct birthday *ptr;

    list_for_each_entry(ptr, &birthday_list, list){

        kprintf('%d/%d/%d \n', ptr -> month, ptr -> day,  ptr -> year);
    }

    list_for_each_entry_safe(ptr, &birthday_list, list){

        list_del(&ptr->list);
        kfree(ptr);
    }

       return 0;
}

/* This function is called when the module is removed. */
void simple_exit(void) {
    printk(KERN_INFO "Removing Module\n");
}

/* Macros for registering module entry and exit points. */
module_init( simple_init );
module_exit( simple_exit );

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Simple Module");
MODULE_AUTHOR("SGG");

Solution 1

I think you must first install something like linux-headers-[kernel version] by apt-get then you must create Makefile as following :

ifneq ($(KERNELRELEASE),)
    # call from kernel build system
    lifo-objs := main.o
    obj-m   := lifo.o
else
   KERNELDIR ?= /lib/modules/$(shell uname -r)/build
   PWD       := $(shell pwd)
modules:
    echo $(MAKE) -C $(KERNELDIR) M=$(PWD) LDDINC=$(PWD)/../include modules
    $(MAKE) -C $(KERNELDIR) M=$(PWD) LDDINC=$(PWD)/../include modules
endif

clean:  
    rm -rf *.o *~ core .depend *.mod.o .*.cmd *.ko *.mod.c \
    .tmp_versions *.markers *.symvers modules.order

depend .depend dep:
    $(CC) $(CFLAGS) -M *.c > .depend

ifeq (.depend,$(wildcard .depend))
    include .depend
endif

set KERNELDIR variable in above Makefile to your appropriate kernel version, by default it use your running kernel. If you use this Makefile you need to change your include to following format:

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>

I think for kernel module developing use standard kernel from Linus Torvalds git is better. For some simple kernel module see this.

Solution 2

When building kernel modules you should use Makefiles:

obj-m := module_name.o

KERNELDIR ?= /lib/modules/$(shell uname -r)/build

all default: modules
install: modules_install

modules modules_install help clean:
    $(MAKE) -C $(KERNELDIR) M=$(shell pwd) $@

Comments

[Robert Crawford]

Well, the thing about it is that this is for an assignment, thus we were given a correct makefile to download and put into the correct directory (which I did, since it already worked at least once) and I tried getting the headers... is that the exact input I'd need to put into the terminal?

[Parham Alvani]

no you must use uname -r first to get your kernel release then use something like sudo apt-get install linux-headers-3.13.0-24-generic to get kernel header for appropriate release.

[Robert Crawford]

yeah, that didn't work. like the comments above, it can't find what I'm trying to install

[Parham Alvani]

Ok please send me your uname -r output in comments.

[Robert Crawford]

It's really strange, now it seems to be working for no reason at all. I was trying to get it done before I met with my professor today, but didn't manage to. We opened it up this morning, ran it, got a bunch of errors, sure, but this wasn't one of them. Thanks for giving it a try!