Re: [GIT PULL] tomoyo update for v6.12

From: Jonathan Corbet
Date: Wed Oct 02 2024 - 10:54:55 EST


Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> writes:

>> Even stranger, to me at least, is the backdoor symbol-export mechanism.
>> That seems like ... not the way we do things. Was the need for this so
>> urgent that you couldn't try to get those symbols exported properly?
>
> Yes. This is a chicken-and-egg problem. Symbols not used by in-tree kernel
> code cannot be justified for export, but I can't prove that loadable LSM
> can work unless I export symbols.

Honestly, this is the part that concerns me the most. The normal way to
deal with this is to create a series with both the exports and the users
so that they can be evaluated together. Instead you seem to have
created just the sort of shim layer that we have not allowed in other
settings, then pushed it upstream without review.

What will you do if, for any reason, one or more of those symbols cannot
be exported? Either you will circumvent that decision indefinitely with
your "temporary hack", or you will remove the hack, regressing things
for your users. Neither seems like a good outcome; that is why we
normally want to actually review things like symbol exports before
pushing them into the mainline.

jon