Hi all, I would like to discuss how to enable per-arg kfunc flags. As described in [0], kfunc flags are currently at the granularity of the entire kfunc. This means that, for example, only a single kfunc argument can be acquired (indicated by KF_ACQUIRE), released (indicated by KF_RELEASE), RCU-protected (KF_RCU), etc. This hasn't really been a problem up to this point, though there are some per-arg annotations such as those described in [1], and patches here and there such as [2], which collectively indicate that it may be time to start aligning on what the design and implemention should look like (e.g. should we model the UX for defining kfuncs in a similar to way to helpers, go in a different direction, what blockers are there, etc). [0]: https://docs.kernel.org/bpf/kfuncs.html#annotating-kfuncs [1]: https://docs.kernel.org/bpf/kfuncs.html#annotating-kfunc-parameters [2]: https://lore.kernel.org/bpf/20221217082506.1570898-2-davemarchevsky@xxxxxx/ What do you all think? Thanks, David
