On Mon, Nov 15, 2021 at 9:27 AM Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> wrote: > > On Mon, Nov 15, 2021 at 07:47:35PM IST, Kumar Kartikeya Dwivedi wrote: > > On Mon, Nov 15, 2021 at 07:04:51PM IST, Pavel Skripkin wrote: > > > Hi, net/bpf developers! > > > > > > While building newest kernel for fuzzing I met following warnings: > > > > > > ``` > > > BTFIDS vmlinux > > > WARN: resolve_btfids: unresolved symbol tcp_dctcp_kfunc_ids > > > WARN: resolve_btfids: unresolved symbol tcp_cubic_kfunc_ids > > > WARN: resolve_btfids: unresolved symbol tcp_bbr_kfunc_ids > > > SORTTAB vmlinux > > > > > > ``` > > +Cc Andrii +Cc Jiri ;) > > So the reason should be CONFIG_DYNAMIC_FTRACE=n, when that is turned off, > all these three BTF sets should be empty. Earlier they were all part of the > set in bpf_tcp_ca.c, which would never be empty, so there was no warning. > > I guess we can demote that warning to debug, but not sure, since it isn't It's a real warning, since when hiding a warning is the right thing to do? Jiri, does resolve_btfids emit this warning when we get an empty set? I'd expect not (empty set is totally reasonable in some cases), but who knows. Can you please help understand this? > limited to BTF sets, but also other symbols (e.g. kernel functions referenced in > .BTF_ids). > > The other option is to add a dummy function in the set so that set->cnt != 0. > > > > > > > I haven't seen such warnings before and have no idea are they important or > > > not. Config is attached. > > > > > > My host is openSUSE Tumbleweed with gcc (SUSE Linux) 10.3.1 20210707 > > > [revision 048117e16c77f82598fca9af585500572d46ad73] if it's important :) > > > > > > > > > > I'll take a look later today. > > > > > > > > With regards, > > > Pavel Skripkin > > > > -- > > Kartikeya > > -- > Kartikeya
