Hi Daniel, On Fri, 30 Jun 2023 16:53:38 +0200 Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote: > On 6/28/23 6:46 PM, SeongJae Park wrote: > > __register_btf_kfunc_id_set() assumes .BTF to be part of the module's > > .ko file if CONFIG_DEBUG_INFO_BTF is enabled. If that's not the case, > > the function prints an error message and return an error. As a result, > > such modules cannot be loaded. > > > > However, the section could be stripped out during a build process. It > > would be better to let the modules loaded, because their basic > > functionalities have no problem[1], though the BTF functionalities will > > not be supported. Make the function to lower the level of the message > > from error to warn, and return no error. > > > > [1] https://lore.kernel.org/bpf/20220219082037.ow2kbq5brktf4f2u@apollo.legion/ > > > > Reported-by: Alexander Egorenkov <Alexander.Egorenkov@xxxxxxx> > > Link: https://lore.kernel.org/bpf/87y228q66f.fsf@xxxxxxxxxxxxxxxxxxxx/ > > Suggested-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> > > Link: https://lore.kernel.org/bpf/20220219082037.ow2kbq5brktf4f2u@apollo.legion/ > > Fixes: c446fdacb10d ("bpf: fix register_btf_kfunc_id_set for !CONFIG_DEBUG_INFO_BTF") > > Cc: <stable@xxxxxxxxxxxxxxx> # 5.18.x > > Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> > > Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> > > I presume this one is targeted at bpf (rather than bpf-next) tree, right? You're correct. It's not urgent for us, but I would prefer it to be merged into all affected kernels as early as possible. > > > diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c > > index 6b682b8e4b50..d683f034996f 100644 > > --- a/kernel/bpf/btf.c > > +++ b/kernel/bpf/btf.c > > @@ -7848,14 +7848,10 @@ static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook, > > > > btf = btf_get_module_btf(kset->owner); > > if (!btf) { > > - if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { > > - pr_err("missing vmlinux BTF, cannot register kfuncs\n"); > > - return -ENOENT; > > - } > > Why the above one needs to be changed? Do you also run into this case? vmlinux BTF > should be built-in in this case. I understand it's rather the one below for BTF + > modules instead, no? Again, you're correct. This change is not really needed. I was interpreting Kumar's suggestion merely into code without thinking about his real meaning, sorry. I will restore this in the next spin. Thanks, SJ > > > - if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { > > - pr_err("missing module BTF, cannot register kfuncs\n"); > > - return -ENOENT; > > - } > > + if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) > > + pr_warn("missing vmlinux BTF, cannot register kfuncs\n"); > > + if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) > > + pr_warn("missing module BTF, cannot register kfuncs\n"); > > return 0; > > } > > if (IS_ERR(btf)) > > > >
