Re: [PATCH net 1/6] netfilter: nf_tables: report use refcount overflow

On Thu, 2023-07-06 at 01:04 +0200, Pablo Neira Ayuso wrote:

Overflow use refcount checks are not complete.

Add helper function to deal with object reference counter tracking.
Report -EMFILE in case UINT_MAX is reached.

nft_use_dec() splats in case that reference counter underflows,
which should not ever happen.

For the records, I also once had the need for an non atomic reference
counters implementing sanity checks on underflows/overflows. I resorted
to use plain refcount_t, since the atomic op overhead was not
noticeable in my use-case.

[not blocking this series, just thinking aloud] I'm wondering if a
generic, non-atomic refcounter infra could be useful?

Cheers,

Paolo