Re: module state:permanent

[Balamurugan Subbian <aspire_bala@xxxxxxxxxxx>]

Even i faced the same problem. After analysis i found that

It should not create problem in removing the mod as well if you are using "init_module" function.
If you are using a different name for the startup function it should be declared as static as:

static int __init startup(void)

module_init(startup)

Probably if the function is not static the kernel loses its refernce to the function and that
makes it permanent.

--Bala

---

From: amit mehta <amit4g@xxxxxxxxx>
To: Sandeep K Sinha <sandeepksinha@xxxxxxxxx>
Cc: Kernel Newbie <kernelnewbies@xxxxxxxxxxxx>
Sent: Wednesday, 10 December, 2008 6:40:42
Subject: Re: module state:permanent

Thanks Sandeep, but still the question holds.
Why this module would become permanent ?

~amit

On Wed, Dec 10, 2008 at 11:46 AM, Sandeep K Sinha <sandeepksinha@xxxxxxxxx> wrote:

Ya that's right.

On Wed, Dec 10, 2008 at 10:48 AM, amit mehta <amit4g@xxxxxxxxx> wrote:
> Hi All,
>
> Why would some module's state become permanent ?
> i inserted one module and when i try to remove it, i get:
> ERROR: Removing 'procsfs1': Device or resource busy
>
> <lsmod snip>
>
> Module                  Size  Used by
> procsfs1                3204  0 [permanent] <---------
>
> <lsmod snip>
>
> The program code is here:
> http://tldp.org/LDP/lkmpg/2.6/html/x710.html
>
> rmmod help shows:
> root@venus:/home/amit/# rmmod --h
> Usage: rmmod [-fhswvV] modulename ...
>  -f (or --force) forces a module unload, and may crash your
>     machine.  This requires the Forced Module Removal option
>     when the kernel was compiled.
>
> i looked into the .config file under /usr/src/linux
> and this seem to be the reason for even the --force option in rmmod not
> working:
> # CONFIG_MODULE_FORCE_UNLOAD is not set
>
>

You have to set that flag to enable forced unmount.

> ~amit
>
> --
> "Everyone has a photographic memory. Some people just don't have film."
>
> — Mel Brooks
>

--
Regards,
Sandeep.






"To learn is to change. Education is a process that changes the learner."

--
"Everyone has a photographic memory. Some people just don't have film."

— Mel Brooks