[CentOS] C7 Kernel module compilation

Mon Aug 5 16:07:37 UTC 2019
Akemi Yagi <amyagi at gmail.com>

On Mon, Aug 5, 2019 at 9:01 AM Alessandro Baggi
<alessandro.baggi at gmail.com> wrote:
>
> Il 05/08/19 17:49, Akemi Yagi ha scritto:
> > On Mon, Aug 5, 2019 at 8:42 AM Alessandro Baggi
> > <alessandro.baggi at gmail.com> wrote:
> >>
> >> Il 05/08/19 17:30, Akemi Yagi ha scritto:
> >>> On Mon, Aug 5, 2019 at 6:46 AM Alessandro Baggi
> >>> <alessandro.baggi at gmail.com> wrote:
> >>>>
> >>>> Hey there,
> >>>> I'm trying to compile a single module following this guide:
> >>>>
> >>>> https://wiki.centos.org/HowTos/BuildingKernelModules#head-d2e4c05886f94c701e4ae74387d41d8c40c25d01
> >>>>
> >>>> and
> >>>>
> >>>> https://wiki.centos.org/HowTos/I_need_the_Kernel_Source
> >>>>
> >>>> I tried to compile a module for novuton led controller supplied by
> >>>> thirdparty and I got several error.
> >>>>
> >>>> To check if this is the wrong procedure I tried to compile cifs module
> >>>> as listed in howto but when loading with modprobe I get "Exec format
> >>>> error", and from dmesg "cifs: no symbol version for module_layout
> >>>> ", the same errors when compiling novuton module and I don't know why I
> >>>> get this error.
> >>>
> >>> When following the instructions in BuildingKernelModules, which kernel
> >>> version did you use? Also, after the "depmod -a" step, what is the
> >>> output from:
> >>>
> >>> $ modinfo cifs | grep filename
> >>>
> >>>> I noticed that modules in centos are compressed in .xz but after running
> >>>> make M=fs/cifs I got only a .ko kernel module and then I run xz to
> >>>> compress the new module.
> >>>
> >>> Compressing modules is optional. Uncompressed form is functionally the
> >>> same (of course it saves some disk space).
> >>>
> >>>> Can someone help me please?
> >>>>
> >>>> Thanks in advance.
> >>>
> >>> Akemi
> >>
> >> Hi Akemi,
> >> thank you for your answer.
> >>
> >> Kernel version used is 3.10.0-957.27.2.el7.x86_64
> >>
> >> [root at c7-test SPECS]# modinfo cifs | grep filename
> >> filename:       /lib/modules/3.10.0-957.27.2.el7.x86_64/extra/cifs.ko
> >
> > Looking good. I assume your running kernel is 3.10.0-957.27.2.el7 ?
> >
> > Akemi

> Reading from dmesg seems that the module is not accepted by kernel due
> to invalid signature. I need to sign the module with a key?

Do you have secureboot enabled? Then yes, that requires a proper key.

Akemi