[CentOS] New C7 kernel ABI and kmods

Sat Mar 4 13:41:18 UTC 2017
Ned Slider <ned at unixmail.co.uk>

On 03/03/17 22:56, Fred Smith wrote:
> On Fri, Mar 03, 2017 at 12:03:52PM -0800, Akemi Yagi wrote:
>> On Fri, Mar 3, 2017 at 9:16 AM, Lamar Owen <lowen at pari.edu> wrote:
>>> All,
>>>
>>> This is just a heads-up that the new C7 update kernel breaks ABI
>>> compatibility, at least as far as using the ELrepo nVidia drivers is
>>> concerned.  I have posted more details to the ELrepo list; but since many
>>> folks use the Elrepo kmods I thought a heads-up would be appropriate.
>>>
>>> If you use the ELrepo nvidia kmod you will either need to hold off on the
>>> kernel update or uninstall the nvidia kmod.
>>
>> This is being tracked here:
>>
>> https://elrepo.org/bugs/view.php?id=720
>
> didn't we just go thru this a few months ago? they're breaking it again?
>
>

It's not uncommon for bits (non kABI whitelisted bits) of the kernel ABI 
to change at point releases, but in my experience it's very uncommon for 
the ABI to change within a point release series. To the best of my 
knowledge I recall it happening twice before on the EL6 kernel, once 
such example was here:

http://elrepo.org/bugs/view.php?id=406

Of course any kABI changes will only affect 3rd party kernel modules 
using those specific ABIs so the vast majority of users will be 
oblivious to the changes. It just so happens in this case it affected 
the 3rd party nvidia drivers which are widely used.