bpf: remove stubs for cBPF from arch code

Remove the dummy bpf_jit_compile() stubs for eBPF JITs and make
that a single __weak function in the core that can be overridden
similarly to the eBPF one. Also remove stale pr_err() mentions
of bpf_jit_compile.

Change-Id: Iac221c09e9ae0879acdd7064d710c4f7cb8f478d
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 1 deletions

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 2b1a925489cf..2cb991abf6c3 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1283,12 +1283,22 @@ const struct bpf_func_proto bpf_tail_call_proto = {
 	.arg3_type	= ARG_ANYTHING,
 };
 
-/* For classic BPF JITs that don't implement bpf_int_jit_compile(). */
+/* Stub for JITs that only support cBPF. eBPF programs are interpreted.
+ * It is encouraged to implement bpf_int_jit_compile() instead, so that
+ * eBPF and implicitly also cBPF can get JITed!
+ */
 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
 {
 	return prog;
 }
 
+/* Stub for JITs that support eBPF. All cBPF code gets transformed into
+ * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
+ */
+void __weak bpf_jit_compile(struct bpf_prog *prog)
+{
+}
+
 bool __weak bpf_helper_changes_skb_data(void *func)
 {
 	return false;