bpf: remove struct bpf_prog_type_list

There's no need to have struct bpf_prog_type_list since
it just contains a list_head, the type, and the ops
pointer. Since the types are densely packed and not
actually dynamically registered, it's much easier and
smaller to have an array of type->ops pointer. Also
initialize this array statically to remove code needed
to initialize it.

In order to save duplicating the list, move it to a new
header file and include it in the places needing it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 14 insertions, 43 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index ab0cf4c43690..ea55691cbf5e 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -573,26 +573,21 @@ err_put:
 	return err;
 }
 
-static LIST_HEAD(bpf_prog_types);
+static const struct bpf_verifier_ops * const bpf_prog_types[] = {
+#define BPF_PROG_TYPE(_id, _ops) \
+	[_id] = &_ops,
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+};
 
 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
 {
-	struct bpf_prog_type_list *tl;
-
-	list_for_each_entry(tl, &bpf_prog_types, list_node) {
-		if (tl->type == type) {
-			prog->aux->ops = tl->ops;
-			prog->type = type;
-			return 0;
-		}
-	}
-
-	return -EINVAL;
-}
+	if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type])
+		return -EINVAL;
 
-void bpf_register_prog_type(struct bpf_prog_type_list *tl)
-{
-	list_add(&tl->list_node, &bpf_prog_types);
+	prog->aux->ops = bpf_prog_types[type];
+	prog->type = type;
+	return 0;
 }
 
 /* drop refcnt on maps used by eBPF program and free auxilary data */
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index cee9802cf3e0..8a4efac28710 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -501,16 +501,11 @@ static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type
 	return true;
 }
 
-static const struct bpf_verifier_ops kprobe_prog_ops = {
+const struct bpf_verifier_ops kprobe_prog_ops = {
 	.get_func_proto  = kprobe_prog_func_proto,
 	.is_valid_access = kprobe_prog_is_valid_access,
 };
 
-static struct bpf_prog_type_list kprobe_tl __ro_after_init = {
-	.ops	= &kprobe_prog_ops,
-	.type	= BPF_PROG_TYPE_KPROBE,
-};
-
 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
 	   u64, flags, void *, data, u64, size)
 {
@@ -584,16 +579,11 @@ static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type
 	return true;
 }
 
-static const struct bpf_verifier_ops tracepoint_prog_ops = {
+const struct bpf_verifier_ops tracepoint_prog_ops = {
 	.get_func_proto  = tp_prog_func_proto,
 	.is_valid_access = tp_prog_is_valid_access,
 };
 
-static struct bpf_prog_type_list tracepoint_tl __ro_after_init = {
-	.ops	= &tracepoint_prog_ops,
-	.type	= BPF_PROG_TYPE_TRACEPOINT,
-};
-
 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
 				    enum bpf_reg_type *reg_type)
 {
@@ -642,22 +632,8 @@ static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
 	return insn - insn_buf;
 }
 
-static const struct bpf_verifier_ops perf_event_prog_ops = {
+const struct bpf_verifier_ops perf_event_prog_ops = {
 	.get_func_proto		= tp_prog_func_proto,
 	.is_valid_access	= pe_prog_is_valid_access,
 	.convert_ctx_access	= pe_prog_convert_ctx_access,
 };
-
-static struct bpf_prog_type_list perf_event_tl __ro_after_init = {
-	.ops	= &perf_event_prog_ops,
-	.type	= BPF_PROG_TYPE_PERF_EVENT,
-};
-
-static int __init register_kprobe_prog_ops(void)
-{
-	bpf_register_prog_type(&kprobe_tl);
-	bpf_register_prog_type(&tracepoint_tl);
-	bpf_register_prog_type(&perf_event_tl);
-	return 0;
-}
-late_initcall(register_kprobe_prog_ops);