kernel/bpf/syscall: fix warning defined but not used

There will be a build warning -Wunused-function if CONFIG_CGROUP_BPF
isn't defined, since the only user is inside #ifdef CONFIG_CGROUP_BPF:
kernel/bpf/syscall.c:1229:12: warning: ‘bpf_prog_attach_check_attach_type’
    defined but not used [-Wunused-function]
 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Current code moves function bpf_prog_attach_check_attach_type inside
ifdef CONFIG_CGROUP_BPF.

Fixes: 5e43f899b03a ("bpf: Check attach type at prog load time")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0244973..4ca46df 100644 (file)
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1226,18 +1226,6 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,
        }
 }
 
-static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
-                                            enum bpf_attach_type attach_type)
-{
-       switch (prog->type) {
-       case BPF_PROG_TYPE_CGROUP_SOCK:
-       case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
-               return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
-       default:
-               return 0;
-       }
-}
-
 /* last field in 'union bpf_attr' used by this command */
 #define        BPF_PROG_LOAD_LAST_FIELD expected_attach_type
 
@@ -1465,6 +1453,18 @@ out_free_tp:
 
 #ifdef CONFIG_CGROUP_BPF
 
+static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
+                                            enum bpf_attach_type attach_type)
+{
+       switch (prog->type) {
+       case BPF_PROG_TYPE_CGROUP_SOCK:
+       case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+               return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
+       default:
+               return 0;
+       }
+}
+
 #define BPF_PROG_ATTACH_LAST_FIELD attach_flags
 
 static int sockmap_get_from_fd(const union bpf_attr *attr,