On Tue, Jul 13, 2021 at 12:44 AM Jakub Sitnicki <jakub@xxxxxxxxxxxxxx> wrote: > > Proc socket stats use sk_prot->inuse_idx value to record inuse sock stats. > We currently do not set this correctly from sockmap side. The result is > reading sock stats '/proc/net/sockstat' gives incorrect values. The > socket counter is incremented correctly, but because we don't set the > counter correctly when we replace sk_prot we may omit the decrement. > > To get the correct inuse_idx value move the core_initcall that initializes > the udp proto handlers to late_initcall. This way it is initialized after > UDP has the chance to assign the inuse_idx value from the register protocol > handler. Interesting. What about IPv6 module? Based on my understanding, it should always be loaded before we can trigger udp_bpf_check_v6_needs_rebuild(). If so, your patch is complete. > > Fixes: 5e21bb4e8125 ("bpf, test: fix NULL pointer dereference on invalid expected_attach_type") Should be commit edc6741cc66059532ba621928e3f1b02a53a2f39 (bpf: Add sockmap hooks for UDP sockets), right? Thanks.