bpf: Fix holes in special_kfunc_list if !CONFIG_NET

If the function is not available its entry has to be replaced with
BTF_ID_UNUSED instead of skipped.
Otherwise the list doesn't work correctly.

Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Closes: https://lore.kernel.org/lkml/CAADnVQJQpVziHzrPCCpGE5=8uzw2OkxP8gqe1FkJ6_XVVyVbNw@mail.gmail.com/
Fixes: 00a5acdbf398 ("bpf: Fix configuration-dependent BTF function references")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20241219-bpf-fix-special_kfunc_list-v1-1-d9d50dd61505@weissschuh.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 419f75c2cabb6113c0803061225348ce4381612d..d77abb87ffb1adefb189b0cf16f143d3813c71c1 100644 (file)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -11739,6 +11739,9 @@ BTF_ID(func, bpf_rbtree_first)
 #ifdef CONFIG_NET
 BTF_ID(func, bpf_dynptr_from_skb)
 BTF_ID(func, bpf_dynptr_from_xdp)
+#else
+BTF_ID_UNUSED
+BTF_ID_UNUSED
 #endif
 BTF_ID(func, bpf_dynptr_slice)
 BTF_ID(func, bpf_dynptr_slice_rdwr)