From: SeongJae Park sj@kernel.org
[ Upstream commit 3de4d22cc9ac7c9f38e10edcf54f9a8891a9c2aa ]
__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 [0], 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.
[0] https://lore.kernel.org/bpf/20220219082037.ow2kbq5brktf4f2u@apollo.legion
Fixes: c446fdacb10d ("bpf: fix register_btf_kfunc_id_set for !CONFIG_DEBUG_INFO_BTF") Reported-by: Alexander Egorenkov Alexander.Egorenkov@ibm.com Suggested-by: Kumar Kartikeya Dwivedi memxor@gmail.com Signed-off-by: SeongJae Park sj@kernel.org Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Jiri Olsa jolsa@kernel.org Link: https://lore.kernel.org/bpf/87y228q66f.fsf@oc8242746057.ibm.com Link: https://lore.kernel.org/bpf/20220219082037.ow2kbq5brktf4f2u@apollo.legion Link: https://lore.kernel.org/bpf/20230701171447.56464-1-sj@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/bpf/btf.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 72b32b7cd9cd9..25ca17a8e1964 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -7848,10 +7848,8 @@ static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook, pr_err("missing vmlinux BTF, cannot register kfuncs\n"); return -ENOENT; } - 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_MODULES)) + pr_warn("missing module BTF, cannot register kfuncs\n"); return 0; } if (IS_ERR(btf))