Kernel Module

Kernel Module

[Femitha Majeed]

Hi,


I am trying to write a kernel module, but I get the follwing error when I do 
"insmod filename.o"

Unable to handle kernel NULL pointer dereference at virtual address ...

I am using kmalloc to allocate memory. I have also used filp_open to open a 
directory and sys_getdents to read directory. Does any of these calls cause 
the above problem?

I am very new to writing kernel modules. I would be grateful if you would 
reply to this.

Thanks,
Femitha.


_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp


--
You have received this message because you are subscribed to the selinux list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.

Re: Kernel Module

[Paul Krumviede]

--On Saturday, 10 November, 2001 17:22 +0000 Femitha Majeed 
<m_femitha@hotmail.com> wrote:

>
> Hi,
>
>
> I am trying to write a kernel module, but I get the follwing error when I
> do "insmod filename.o"
>
> Unable to handle kernel NULL pointer dereference at virtual address ...

you don't mention anything about a particular version of selinux, so this
may not be relevant, but stephen smalley posted a patch to the selinux
security module which was noticed when people noticed this particular
problem when attempting to install or run mozilla. the message was
dated 22 oct. 2001 and would apply to the 2.4.12-lsm based distribution.

if you don't have the message in question, i (or others) could forward it,
or it is presumably available in an archive.

-paul


--
You have received this message because you are subscribed to the selinux list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.

Kernel Module

[chinnakka.b]

Hello sir,
After building the kernel i tried to insert the modules scsi_mod,sd_mod,usb-
storage
It is giving could not find the kernel version the module was compiled for
what is wrong with this?
waiting for your response
regards
chinnakka

Re: Kernel Module

[rasman]

On Wednesday 11 Dec 2002 11:40 am, chinnakka.b@bplmail.com wrote:
> Hello sir,
> After building the kernel i tried to insert the modules
> scsi_mod,sd_mod,usb- storage
> It is giving could not find the kernel version the module was compiled for
> what is wrong with this?
> waiting for your response
> regards
> chinnakka
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

Did you change the kernel version? 
If so did  you "make modules" followes by "make modules_install"?
See the kernel README


-- 
Richard J Moore
RAS Team Lead - IBM Linux Technology Centre

kernel module

[Rajeh kuri]

Hi,

Is there any ways to invoke/call the function (kernel module
functions) from compiled base kernel. Well that statement sounds
strange.

I will try to simplify that statement, with problem I faced.
I have written a kernel module but it is of no use till I call one of
its function from kernel, and hence i modified the kernel source to
call this function and then compiled the kernel. Now the problem is
obliviously 'linker cannot resolve the symbol. Because I'm trying to
call the function which is available only after I insert the kernel
module.

Is this a right approach? I'm using the kernel module concept in opposite way.

Any pointers or suggestions will be greatly appreciated.

TIA...

--Regards,
rajesh
-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

Re: kernel module

[Kristof Provost]

[-- Attachment #1: Type: text/plain, Size: 961 bytes --]

Hi,

On 2007-11-12 19:29:17 (+0530), Rajeh kuri <rajeshkuri@gmail.com> wrote:
> Hi,
> 
> Is there any ways to invoke/call the function (kernel module
> functions) from compiled base kernel. Well that statement sounds
> strange.
> 
> I will try to simplify that statement, with problem I faced.
> I have written a kernel module but it is of no use till I call one of
> its function from kernel, and hence i modified the kernel source to
> call this function and then compiled the kernel. Now the problem is
> obliviously 'linker cannot resolve the symbol. Because I'm trying to
> call the function which is available only after I insert the kernel
> module.
The problem is that you're calling code compiled as a module from code
compiled into the kernel. That means you either compile both parts as a 
module, or compile both of them into the kernel.
Kbuild/Kconfig has supports this type of dependency because it's quite
common.

Kristof

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]

Re: kernel module

[Rajeh kuri]

Well it means there is no way to achieve compiled kernel calling
compiled kernel module. OR The direction of communication from kernel
to kernel module can not be possible?

I believe there must be a way around to get this work.
If i find it will update here.

--Regards,
rajesh
On Nov 13, 2007 3:10 PM, Kristof Provost <Kristof@provost-engineering.be> wrote:
> Hi,
>
> On 2007-11-12 19:29:17 (+0530), Rajeh kuri <rajeshkuri@gmail.com> wrote:
> > Hi,
> >
> > Is there any ways to invoke/call the function (kernel module
> > functions) from compiled base kernel. Well that statement sounds
> > strange.
> >
> > I will try to simplify that statement, with problem I faced.
> > I have written a kernel module but it is of no use till I call one of
> > its function from kernel, and hence i modified the kernel source to
> > call this function and then compiled the kernel. Now the problem is
> > obliviously 'linker cannot resolve the symbol. Because I'm trying to
> > call the function which is available only after I insert the kernel
> > module.
> The problem is that you're calling code compiled as a module from code
> compiled into the kernel. That means you either compile both parts as a
> module, or compile both of them into the kernel.
> Kbuild/Kconfig has supports this type of dependency because it's quite
> common.
>
> Kristof
>
-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

Re: kernel module

[Kristof Provost]

[-- Attachment #1: Type: text/plain, Size: 865 bytes --]

On 2007-11-13 17:53:11 (+0530), Rajeh kuri <rajeshkuri@gmail.com> wrote:
> Well it means there is no way to achieve compiled kernel calling
> compiled kernel module. OR The direction of communication from kernel
> to kernel module can not be possible?
It is possible and it's done quite often. You just need to handle things
slightly differently.

Take a filesystem for example. They can be built as a module, and still
be used by the kernel. In this case that's basically done by function
pointers.
When the fs module is loaded it registers itself to the kernel and
passes pointers to the basic operations to the kernel.

The kernel itself doesn't contain any calls to (for example)
fat_statfs. That's only used in the fat module. The kernel calls
the statfs function pointer in the super_operations struct the fat
module registered when it was loaded.


Kristof


[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]

Re: kernel module

[Rodrigo Rubira Branco (BSDaemon)]

Export the symbol in the kernel and then hook it in your module ;)


cya,


Rodrigo (BSDaemon).

--
http://www.kernelhacking.com/rodrigo

Kernel Hacking: If i really know, i can hack

GPG KeyID: 1FCEDEA1


--------- Mensagem Original --------
De: Rajeh kuri <rajeshkuri@gmail.com>
Para: Kristof Provost <Kristof@provost-engineering.be>
Cópia: linux-newbie@vger.kernel.org
Assunto: Re: kernel module
Data: 13/11/07 09:13

>
> Well it means there is no way to achieve compiled kernel calling
> compiled kernel module. OR The direction of communication from kernel
> to kernel module can not be possible?
>
> I believe there must be a way around to get this work.
> If i find it will update here.
>
> --Regards,
> rajesh
> On Nov 13, 2007 3:10 PM, Kristof Provost
&lt;Kristof@provost-engineering.be&gt; wrote:
> &gt; Hi,
> &gt;
> &gt; On 2007-11-12 19:29:17 (+0530), Rajeh kuri
&lt;rajeshkuri@gmail.com&gt; wrote:
> &gt; &gt; Hi,
> &gt; &gt;
> &gt; &gt; Is there any ways to invoke/call the function (kernel module
> &gt; &gt; functions) from compiled base kernel. Well that statement sounds
> &gt; &gt; strange.
> &gt; &gt;
> &gt; &gt; I will try to simplify that statement, with problem I faced.
> &gt; &gt; I have written a kernel module but it is of no use till I call
one of
> &gt; &gt; its function from kernel, and hence i modified the kernel source
to
> &gt; &gt; call this function and then compiled the kernel. Now the problem
is
> &gt; &gt; obliviously 'linker cannot resolve the symbol. Because I'm
trying to
> &gt; &gt; call the function which is available only after I insert the
kernel
> &gt; &gt; module.
> &gt; The problem is that you're calling code compiled as a module from
code
> &gt; compiled into the kernel. That means you either compile both parts as
a
> &gt; module, or compile both of them into the kernel.
> &gt; Kbuild/Kconfig has supports this type of dependency because it's
quite
> &gt; common.
> &gt;
> &gt; Kristof
> &gt;
> -
> To unsubscribe from this list: send the line &quot;unsubscribe
linux-newbie&quot; in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.linux-learn.org/faqs
>
>
>
>

________________________________________________
Message sent using UebiMiau 2.7.2

-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

Kernel module

[Dilip Kumar]

[-- Attachment #1: Type: text/plain, Size: 174 bytes --]

Hi,
What all the modifications has to be done and steps to follow for adding
external kernel module into the linux-yocto and checking that in qemulator.

regards
dilip

[-- Attachment #2: Type: text/html, Size: 215 bytes --]

Re: Kernel module

[Diego Sueiro]

[-- Attachment #1: Type: text/plain, Size: 612 bytes --]

Dilip,

You can take a look at this example :

http://git.yoctoproject.org/cgit/cgit.cgi/poky/tree/meta-skeleton/recipes-kernel/hello-mod

-- 
*dS

Diego Sueiro
sent from my droid tablet.
On Oct 11, 2013 11:17 PM, "Dilip Kumar" <008dilip@gmail.com> wrote:

> Hi,
> What all the modifications has to be done and steps to follow for adding
> external kernel module into the linux-yocto and checking that in qemulator.
>
> regards
> dilip
>
> _______________________________________________
> yocto mailing list
> yocto@yoctoproject.org
> https://lists.yoctoproject.org/listinfo/yocto
>
>

[-- Attachment #2: Type: text/html, Size: 1189 bytes --]