problem with kernel module

[RikD]

Hope someone can help...

Have very strange problem...
Basically I have a very simple "hello world" kernel module.
file is

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

MODULE_DESCRIPTION("MyKernelMod");
MODULE_AUTHOR("Me");
MODULE_LICENSE("GPL");

static int initMyModule(void) {
   printk("Loading MyModule\n");
   return 0;
}

static void closeMyModule(void) {
   printk("Closing MyModule\n");
}

module_init(initMyModule);
module_exit(closeMyModule);

I build it through the "make -C <kernel_src> -M=$(PWD) modules"

the insmod the module.

But the init doesn't work - I don't see in /proc/kmsg, console or syslog
"Loading MyModule" but rmmod does!!!

Any ideas where to begin to look?

TIA
RikD

[Franklin52]

You can check if your module is loaded, with (assuming your module name is hello.ko):

lsmod | grep hello

Regards

[RikD]

Module appears to load
lsmod shows the module is there.

But am curious as to why the initMyModule() code hasn't been executed, or what would make the system skip it?

[Franklin52]

You haven't specify a priority in your printk() statement, try (without a comma between the priority and the message):

printk(KERN_INFO "Loading MyModule\n");

and:

printk(KERN_INFO "Closing MyModule\n");

You can find the priorities in "kernel.h".

Regards