bpf: Remove check_kfunc_call callback and old kfunc BTF ID API

Completely remove the old code for check_kfunc_call to help it work
with modules, and also the callback itself.

The previous commit adds infrastructure to register all sets and put
them in vmlinux or module BTF, and concatenates all related sets
organized by the hook and the type. Once populated, these sets remain
immutable for the lifetime of the struct btf.

Also, since we don't need the 'owner' module anywhere when doing
check_kfunc_call, drop the 'btf_modp' module parameter from
find_kfunc_desc_btf.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220114163953.1455836-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 9 insertions, 8 deletions

diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index df3b292a8ffe..c0805d0d753f 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -109,26 +109,27 @@ static struct bin_attribute bin_attr_bpf_testmod_file __ro_after_init = {
 	.write = bpf_testmod_test_write,
 };
 
-BTF_SET_START(bpf_testmod_kfunc_ids)
+BTF_SET_START(bpf_testmod_check_kfunc_ids)
 BTF_ID(func, bpf_testmod_test_mod_kfunc)
-BTF_SET_END(bpf_testmod_kfunc_ids)
+BTF_SET_END(bpf_testmod_check_kfunc_ids)
 
-static DEFINE_KFUNC_BTF_ID_SET(&bpf_testmod_kfunc_ids, bpf_testmod_kfunc_btf_set);
+static const struct btf_kfunc_id_set bpf_testmod_kfunc_set = {
+	.owner     = THIS_MODULE,
+	.check_set = &bpf_testmod_check_kfunc_ids,
+};
 
 static int bpf_testmod_init(void)
 {
 	int ret;
 
-	ret = sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file);
-	if (ret)
+	ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_testmod_kfunc_set);
+	if (ret < 0)
 		return ret;
-	register_kfunc_btf_id_set(&prog_test_kfunc_list, &bpf_testmod_kfunc_btf_set);
-	return 0;
+	return sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file);
 }
 
 static void bpf_testmod_exit(void)
 {
-	unregister_kfunc_btf_id_set(&prog_test_kfunc_list, &bpf_testmod_kfunc_btf_set);
 	return sysfs_remove_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file);
 }