Merge branch 'move-attach_type-into-bpf_link'

Tao Chen says:

====================
Move attach_type into bpf_link

Andrii suggested moving the attach_type into bpf_link, the previous discussion
is as follows:
https://lore.kernel.org/bpf/CAEf4BzY7TZRjxpCJM-+LYgEqe23YFj5Uv3isb7gat2-HU4OSng@mail.gmail.com

patch1 add attach_type in bpf_link, and pass it to bpf_link_init, which
will init the attach_type field.

patch2-7 remove the attach_type in struct bpf_xx_link, update the info
with bpf_link attach_type.

There are some functions finally call bpf_link_init but do not have bpf_attr
from user or do not need to init attach_type from user like bpf_raw_tracepoint_open,
now use prog->expected_attach_type to init attach_type.

bpf_struct_ops_map_update_elem
bpf_raw_tracepoint_open
bpf_struct_ops_test_run

Feedback of any kind is welcome, thanks.
====================

Link: https://patch.msgid.link/20250710032038.888700-1-chen.dylane@linux.dev
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

2 files changed, 17 insertions, 13 deletions

diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index 70c8b94e797a..082ccd8ad96b 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -103,7 +103,6 @@ struct bpf_cgroup_storage {
 struct bpf_cgroup_link {
 	struct bpf_link link;
 	struct cgroup *cgroup;
-	enum bpf_attach_type type;
 };
 
 struct bpf_prog_list {
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 34dd90ec7fad..bc887831eaa5 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1729,12 +1729,10 @@ struct bpf_link {
 	enum bpf_link_type type;
 	const struct bpf_link_ops *ops;
 	struct bpf_prog *prog;
-	/* whether BPF link itself has "sleepable" semantics, which can differ
-	 * from underlying BPF program having a "sleepable" semantics, as BPF
-	 * link's semantics is determined by target attach hook
-	 */
-	bool sleepable;
+
 	u32 flags;
+	enum bpf_attach_type attach_type;
+
 	/* rcu is used before freeing, work can be used to schedule that
 	 * RCU-based freeing before that, so they never overlap
 	 */
@@ -1742,6 +1740,11 @@ struct bpf_link {
 		struct rcu_head rcu;
 		struct work_struct work;
 	};
+	/* whether BPF link itself has "sleepable" semantics, which can differ
+	 * from underlying BPF program having a "sleepable" semantics, as BPF
+	 * link's semantics is determined by target attach hook
+	 */
+	bool sleepable;
 };
 
 struct bpf_link_ops {
@@ -1781,7 +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;
 };
@@ -2034,11 +2036,13 @@ int bpf_prog_ctx_arg_info_init(struct bpf_prog *prog,
 
 #if defined(CONFIG_CGROUP_BPF) && defined(CONFIG_BPF_LSM)
 int bpf_trampoline_link_cgroup_shim(struct bpf_prog *prog,
-				    int cgroup_atype);
+				    int cgroup_atype,
+				    enum bpf_attach_type attach_type);
 void bpf_trampoline_unlink_cgroup_shim(struct bpf_prog *prog);
 #else
 static inline int bpf_trampoline_link_cgroup_shim(struct bpf_prog *prog,
-						  int cgroup_atype)
+						  int cgroup_atype,
+						  enum bpf_attach_type attach_type)
 {
 	return -EOPNOTSUPP;
 }
@@ -2528,10 +2532,11 @@ int bpf_map_new_fd(struct bpf_map *map, int flags);
 int bpf_prog_new_fd(struct bpf_prog *prog);
 
 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
-		   const struct bpf_link_ops *ops, struct bpf_prog *prog);
+		   const struct bpf_link_ops *ops, struct bpf_prog *prog,
+		   enum bpf_attach_type attach_type);
 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
 			     const struct bpf_link_ops *ops, struct bpf_prog *prog,
-			     bool sleepable);
+			     enum bpf_attach_type attach_type, bool sleepable);
 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer);
 int bpf_link_settle(struct bpf_link_primer *primer);
 void bpf_link_cleanup(struct bpf_link_primer *primer);
@@ -2883,13 +2888,13 @@ bpf_prog_inc_not_zero(struct bpf_prog *prog)
 
 static inline void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
 				 const struct bpf_link_ops *ops,
-				 struct bpf_prog *prog)
+				 struct bpf_prog *prog, enum bpf_attach_type attach_type)
 {
 }
 
 static inline void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
 					   const struct bpf_link_ops *ops, struct bpf_prog *prog,
-					   bool sleepable)
+					   enum bpf_attach_type attach_type, bool sleepable)
 {
 }