On Wed, Apr 07, 2021 at 10:30:31AM -0500, Josh Poimboeuf wrote:

On Wed, Apr 07, 2021 at 04:09:44PM +0200, Peter Zijlstra wrote:

quoted

On Tue, Apr 06, 2021 at 10:54:23AM -0500, Josh Poimboeuf wrote:

quoted

Same for Red Hat.  Unloading livepatch modules seems to work fine, but
isn't officially supported.

That said, if rmmod is just considered a development aid, and we're
going to be ignoring bugs, we should make it official with a new
TAINT_RMMOD.

Another option would be to have live-patch modules leak a module
reference by default, except when some debug sysctl is set or something.
Then only those LP modules loaded while the sysctl is set to 'YOLO' can
be unloaded.

The issue is broader than just live patching.

My suggestion was that if we aren't going to fix bugs in kernel module
unloading, then unloading modules shouldn't be supported, and should
taint the kernel.

Hold up, what? However much I dislike modules (and that is lots), if you
don't want to support rmmod, you have to leak a reference to self in
init. Barring that you get to fix any and all unload bugs.