Version magic issue since 4.10

[Seth Forshee]

On Thu, Jul 27, 2017 at 12:39:52PM -0400, Bread Cutter wrote:
> Hi all,
> 
> I'm running Ubuntu 16.04, and recently upgraded to the 4.10 kernel
> (4.10.0-27-generic #30~16.04.2-Ubuntu).
> 
> In prior versions (4.8.x), I was able to checkout the tag, and build
> the KVM module. I'm doing this so I can make modifications, but the
> same issue occurs if I build it straight from the original source. My
> build steps are as follows:
> 
> git checkout Ubuntu-hwe-4.10.0-27.30_16.04.2
> cp /usr/src/linux-headers-`uname -r`/Module.symvers ./
> cp /boot/config-`uname -r` ./.config
> make oldconfig
> make prepare
> make modules_prepare
> make scripts
> make -j4 SUBDIRS=arch/x86/kvm/
> 
> This always produced usable kernel modules in the past, but with the
> 4.10 series, modprobe prints "Exec format error", and I see this error
> in dmesg:
> 
> kvm: version magic '4.10.17 SMP mod_unload ' should be
> '4.10.0-27-generic SMP mod_unload
> 
> Why is the version magic reporting 4.10.17 when I build myself? And
> how do I have it build as 4.10.0-27-generic instead?

Adding KERNELVERSION=4.10.0-27-generic to your make command should fix
that.

Seth