printk() not outputting

printk() not outputting

[Richard Langly]

I've got a problem making it hard for me to debug. For some reason, my
printk()'s aren't putting anything out to my /var/log/messages file. I
am running X so, as I understand it, messages won't appear in the
terminals where I insmod the module. But they should appear in
/var/log/messages.

If I load my test module, I do get a message from /var/log/messages saying ....

Oct  3 14:50:04 Tux sudo:   whisper : TTY=pts/12 ;
PWD=/home/whisper/test-mod/kernel/net/tm ; USER=root ;
COMMAND=/sbin/insmod mymod.ko

My problem appears as simple as this.
static int __init my_init(void) {
    printk(KERN_CRIT "my_init ...\n");

    // ...

    return 0;
}

static void __exit my_exit(void) {
    printk(KERN_INFO "my_exit ...\n");
}

Also, the values in my /proc/sys/kernel/printk file are:
8 4 1 7

So I changed the first value to 8, and I still don't see messages in
my /var/log/messages file, nor using dmesg.

When I load the module, it's just this ...
make
sudo depmod -a
sudo insmod ./mymod.ko

And I don't see anything in my syslog-ng.conf that would prevent this.

Any help much appreciated.

Re: printk() not outputting

[Jiri Slaby]

On 10/09/2009 08:22 PM, Richard Langly wrote:
> So I changed the first value to 8, and I still don't see messages in
> my /var/log/messages file, nor using dmesg.

Well, if there is no other code than you posted, there's missing
module_init(my_init); line.