I manage 300+ machines that run openafs that has a dkms built kernel module like the nvidia module that needs to be built. I also manage dozens of nvidia gpu servers where users have sudo access and can install anything they want. Here is a snippet of what I found. Note this is for 16.04 systems but 14.04 systems running the 4.4.0-116 kernel will have similar problems:
Short story, if your machine is not using the Ubuntu supplied gcc you will have issues with afs and nvidia built kernel modules or any dkms built kernel modules. Longer story below. NOTE! this problem affects at least, openafs, nvidia, virtual box or any dkms built module. I am going to forward this info to gr...@cs.unc.edu. This started with the latest Ubuntu 4.4.0-116 kernel version. Looking through that bug and testing took me hours. The short story is the machines having issues with openafs.ko module are ones that have the Ubuntu toolchain ppa that has a gcc compiler suite that does not support the "retpoline" feature which was recently put in to fix the Spectre security issue. The nvidia module will also have issues. The machines using the Ubuntu supplied gcc compiler are the ones that are not having issues. But, host olympia was a special case. The compiler that works, using "gcc -v" gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.9) The ones that don't work like host bvisionserver8: gcc version 5.4.1 20160904 You can use "apt-cache policy gcc" to show what repo the compiler comes from. WARNING, /usr/bin/gcc is a link to /usr/bin/gcc-5, the gcc package is a meta package and you need to query gcc-5. If you query gcc it shows coming from the standard Ubuntu repo but /usr/bin/gcc-5 is coming from the toolchain repo. A good gcc-5 shows: ---------------------------- classroom:55% apt-cache policy gcc-5 gcc-5: Installed: 5.4.0-6ubuntu1~16.04.9 Candidate: 5.4.0-6ubuntu1~16.04.9 Version table: *** 5.4.0-6ubuntu1~16.04.9 500 500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages 500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages 100 /var/lib/dpkg/status 5.3.1-14ubuntu2 500 500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages The bad compilers show: ---------------------------------- bvisionserver8:/> apt-cache policy gcc-5 gcc-5: Installed: 5.4.1-2ubuntu1~16.04 Candidate: 5.4.1-2ubuntu1~16.04 Version table: *** 5.4.1-2ubuntu1~16.04 500 500 http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu xenial/main amd64 Packages 100 /var/lib/dpkg/status 5.4.0-6ubuntu1~16.04.9 500 500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages 500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages 5.3.1-14ubuntu2 500 500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages And you can see /etc/apt/sources.list.d/ubuntu-toolchain-r-ubuntu-test-xenial.list repo is configure on those machines. On a good machine modinfo openafs shows that retpoline is turned on in the vermagic: line: classroom:56% modinfo openafs filename: /lib/modules/4.4.0-116-generic/updates/dkms/openafs.ko license: http://www.openafs.org/dl/license10.html srcversion: 4E1BEB8CE16072EF8E64542 depends: vermagic: 4.4.0-116-generic SMP mod_unload modversions retpoline And not turned on a bad machine: bvisionserver8:/> modinfo openafs filename: /lib/modules/4.4.0-116-generic/updates/dkms/openafs.ko license: http://www.openafs.org/dl/license10.html srcversion: 66044F5DC18AA3288DB22FF depends: vermagic: 4.4.0-116-generic SMP mod_unload modversions -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1750937 Title: 4.4.0-116 Kernel update on 2/21 breaks Nvidia drivers (on 14.04 and 16.04) by an insufficient compiler! To manage notifications about this bug go to: https://bugs.launchpad.net/gcc/+bug/1750937/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp