On Mon, Mar 13, 2017 at 11:39:36AM +0530, SIMRAN SINGHAL wrote:

On Mon, Mar 13, 2017 at 10:42 AM, Alexander Kapshuk
[off-list ref] wrote:

quoted

On Mon, Mar 13, 2017 at 6:18 AM, SIMRAN SINGHAL
[off-list ref] wrote:

quoted

On Mon, Mar 13, 2017 at 12:05 AM, Alexander Kapshuk
[off-list ref] wrote:

quoted

On Sun, Mar 12, 2017 at 8:20 PM, SIMRAN SINGHAL
[off-list ref] wrote:

quoted

On Sun, Mar 12, 2017 at 10:15 PM, Alexander Kapshuk
[off-list ref] wrote:

quoted

On Sun, Mar 12, 2017 at 5:34 PM,  [off-list ref] wrote:

quoted

On Sun, 12 Mar 2017 15:49:31 +0200, Alexander Kapshuk said:

quoted

Are these drivers, drivers/iio/dummy/{iio_dummy_evgen,iio_dummy}.ko,
something of your own making, as I'm not seeing them in the kernel
source tree?

The 'modules_install' make target installs drivers that have been
compiled as modules as opposed to those compiled into the kernel, into
/lib/modules/`uname -r`. For your own modules added to the kernel
source tree, or built out-of-tree, that would involve putting
appropriate entries into  Kconfig and/or Makefiles.

Modeprobe expects your module to be found in /lib/modules/`uname -r`.
Otherwise, your module won't get loaded.

One other thing to remember is that although 'make modules_install' will
take all the .ko files from in-tree modules and put them in their proper
place in /lib/modules/`uname-r`  and then run 'depmod', many out-of-tree
Makefiles manage to forget to do that last step.

modprobe is a wrapper around insmod - and the file produced by 'depmod'
are what the wrapper uses to find the module.

Thanks for elaborating on that.

Still not working

First I executed following commands:-

$ make drivers/iio/dummy/iio_dummy_evgen.ko
$ make drivers/iio/dummy/iio_dummy.ko

Above commands executed successfully

Then I run following command:
$ insmod iio_dummy_evgen.ko

Getting following error:
insmod: ERROR: could not load module iio_dummy_evgen.ko: No such file
or directory

And, then I try executing them from driver/staging/dummy and then I
got this error:
insmod: ERROR: could not insert module iio_dummy_evgen.ko: Operation
not permitted

You have to run insmod as user root. Either specify the full path to
your module, or cd into the directory where the module is and run
insmod from there.

I tried this before also but as you said I tried it again:
# insmod iio_dummy_evgen.ko
insmod: ERROR: could not insert module iio_dummy_evgen.ko: Invalid module format

Now, I am getting this error.

Sounds like your kernel module has been compiled for kernel sources
whose version is different to the version of the kernel you are trying
to load your module into.

See http://www.tldp.org/LDP/lkmpg/2.6/html/x380.html for details.

In other words, the version output by 'uname -r' must match the
version output by 'modinfo iio_dummy_evgen.ko | grep vermagic'.

Hi,

The problem is same you got, I have different versions of uname-r and the
version output I got through vermagic.

# modinfo iio_dummy_evgen.ko
filename:
/home/simran/git/kernels/staging/drivers/iio/dummy/iio_dummy_evgen.ko
license:        GPL v2
description:    IIO dummy driver
author:         Jonathan Cameron [off-list ref]
srcversion:     A8AC238EC07833E018CAF7B
depends:        industrialio
intree:         Y
vermagic:       4.11.0-rc1+ SMP mod_unload modversions


$ uname -r
4.10.0-rc3+

How to deal with this?

You did look in the kernel log when modprobe or insmod failed, right?
It should tell you what went wrong.

As others pointed out, you need to build your module against the kernel
you are running.

good luck!

greg k-h