Unable to remove kernel module showing permanent using lsmod

[Dave Hylands]

Hi sakthi,

On Wed, Mar 23, 2011 at 10:08 PM, sakthi selvam <sakthi.cdm at gmail.com> wrote:
> Dear All,
>
> Need your assistance:
>
> Currently I am using Wind River Linux distribution OS with kernel
> version 2.6.27.39 and Wind River version pne-3. After loading of my
> kernel module, I found it was permanent in the kernel using lsmod (for
> ex see below Ref 1). When I tried to remove, it was displaying as
> “ERROR: Removing 'hsl_module': Device or resource busy”. For your
> information, the same module is working fine with the Wind River pne-2
> Linux Distribution OS with kernel version 2.6.21.
> >From the kernel source, I came to know that only possibility of
> showing permanent is “if there is non-availability of cleanup_module
> and with the availability of init_module”.
>
> But in my case, cleanup module also available in memory, after loading
> the module. I used to check using the file in /proc/kallsyms for the
> availability of cleanup module in memory.
>
> Thanks for reading. Prompt reply is expected to identify the root cause.
>
> Ref 1:
> Module                  Size  Used by
> hsl_module            530454  0 [permanent]

Modules show up as permanent when they don't have a module_exit
procedure declared. Since no module_exit was provided, they can't be
unloaded.

-- 
Dave Hylands
Shuswap, BC, Canada
http://www.davehylands.com