[PATCH v2 1/3] bpf: make bpf_key an opaque type

[James Bottomley <James.Bottomley@HansenPartnership.com>]

Since the only consumers of struct bpf_key are bpf scripts which call
the bpf kfuncs which take struct bpf_key, only the implementing
functions in bpf_trace.c should be reaching inside this structure.
Enforce this by making the structure opaque in the header with a body
that's only defined inside bpf_trace.c

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
---
 include/linux/bpf.h      | 5 +----
 kernel/trace/bpf_trace.c | 5 +++++
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index f9cd2164ed23..34b2df7aaf3e 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -3656,10 +3656,7 @@ static inline void bpf_cgroup_atype_put(int cgroup_atype) {}
 struct key;
 
 #ifdef CONFIG_KEYS
-struct bpf_key {
-	struct key *key;
-	bool has_ref;
-};
+struct bpf_key;
 #endif /* CONFIG_KEYS */
 
 static inline bool type_is_alloc(u32 type)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 3ae52978cae6..e7bf00d1cd05 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1242,6 +1242,11 @@ static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
 };
 
 #ifdef CONFIG_KEYS
+struct bpf_key {
+	struct key *key;
+	bool has_ref;
+};
+
 __bpf_kfunc_start_defs();
 
 /**
-- 
2.43.0