bpf: Remove attach_type in bpf_tracing_link

Use attach_type in bpf_link, and remove it in bpf_tracing_link.

Signed-off-by: Tao Chen <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

Author: Tao Chen

include/linux/bpf.h

@@ -1784,7 +1784,6 @@ struct bpf_shim_tramp_link {
 
 struct bpf_tracing_link {
 	struct bpf_tramp_link link;
-	enum bpf_attach_type attach_type;
 	struct bpf_trampoline *trampoline;
 	struct bpf_prog *tgt_prog;
 };

kernel/bpf/syscall.c

@@ -3414,7 +3414,7 @@ static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
 		   "target_obj_id:\t%u\n"
 		   "target_btf_id:\t%u\n"
 		   "cookie:\t%llu\n",
-		   tr_link->attach_type,
+		   link->attach_type,
 		   target_obj_id,
 		   target_btf_id,
 		   tr_link->link.cookie);
@@ -3426,7 +3426,7 @@ static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
 	struct bpf_tracing_link *tr_link =
 		container_of(link, struct bpf_tracing_link, link.link);
 
-	info->tracing.attach_type = tr_link->attach_type;
+	info->tracing.attach_type = link->attach_type;
 	info->tracing.cookie = tr_link->link.cookie;
 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
 				  &info->tracing.target_obj_id,
@@ -3516,7 +3516,6 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog,
 	bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
 		      &bpf_tracing_link_lops, prog, attach_type);
 
-	link->attach_type = prog->expected_attach_type;
 	link->link.cookie = bpf_cookie;
 
 	mutex_lock(&prog->aux->dst_mutex);