kfunc arg.patch

commit 32ace24aeff9c815b2792cbbd9c69512d17882d6
Author: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date:   Fri May 20 15:14:09 2022 +0530

    stage

diff --git a/include/linux/btf.h b/include/linux/btf.h
index 2611cea2c2b6..c4b355bdf552 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -12,6 +12,73 @@
 #define BTF_TYPE_EMIT(type) ((void)(type *)0)
 #define BTF_TYPE_EMIT_ENUM(enum_val) ((void)enum_val)
 
+#define BTF_ARG_NONE	      0
+#define BTF_ARG_SIZE	      1
+#define BTF_ARG_PTR_TO_MEM    2
+#define BTF_ARG_PTR_TO_CTX    3
+#define BTF_ARG_PTR_TO_BTF_ID 4
+#define BTF_ARG_RET_PTR_SIZE  5
+
+#define BTF_ARG_RET_PTR_NULL  29
+#define BTF_ARG_PTR_REF	      30
+#define BTF_ARG_PTR_NULL      31
+#define BTF_ARG_MAX	      BTF_ARG_PTR_NULL + 1
+
+#define __KARG_N(type, name, t1, t2, t3, t4, t5) type, name, t1, t2, t3, t4, t5
+#define __KARG_N_EXP(type, name, t1, t2, t3, t4, t5, ...)				\
+	__KARG_N(type, name, BTF_ARG_##t1, BTF_ARG_##t2, BTF_ARG_##t3, BTF_ARG_##t4, BTF_ARG_##t5)
+#define KARG(type, name, ...) __KARG_N_EXP(type, name, ##__VA_ARGS__, BTF_ARG_NONE,	\
+					   BTF_ARG_NONE, BTF_ARG_NONE, BTF_ARG_NONE, BTF_ARG_NONE)
+
+#define __KARG_NAME_TAG(arg, t1, t2, t3, t4, t5) arg##__##t1##_##t2##_##t3##_##t4##_##t5
+#define __KARG_NAME_NOTAG(arg, t1, t2, t3, t4, t5) arg
+#define __KARG_DECL(select, type, arg, t1, t2, t3, t4, t5)				\
+	type __KARG_NAME_##select(arg, t1, t2, t3, t4, t5)
+
+#define __KARG_DECL_0(...)
+#define __KARG_DECL_1(select, type, arg, t1, t2, t3, t4, t5, ...)			\
+	__KARG_DECL(select, type, arg, t1, t2, t3, t4, t5)
+#define __KARG_DECL_2(select, type, arg, t1, t2, t3, t4, t5, ...)			\
+	__KARG_DECL(select, type, arg, t1, t2, t3, t4, t5), __KARG_DECL_1(select, ##__VA_ARGS__)
+#define __KARG_DECL_3(select, type, arg, t1, t2, t3, t4, t5, ...)			\
+	__KARG_DECL(select, type, arg, t1, t2, t3, t4, t5), __KARG_DECL_2(select, ##__VA_ARGS__)
+#define __KARG_DECL_4(select, type, arg, t1, t2, t3, t4, t5, ...)			\
+	__KARG_DECL(select, type, arg, t1, t2, t3, t4, t5), __KARG_DECL_3(select, ##__VA_ARGS__)
+#define __KARG_DECL_5(select, type, arg, t1, t2, t3, t4, t5, ...)			\
+	__KARG_DECL(select, type, arg, t1, t2, t3, t4, t5), __KARG_DECL_4(select, ##__VA_ARGS__)
+
+#define __KARG_DECL_N_TAG(n, ...) __KARG_DECL_##n(TAG, ##__VA_ARGS__)
+#define __KARG_DECL_N_NOTAG(n, ...) __KARG_DECL_##n(NOTAG, ##__VA_ARGS__)
+
+#define __KARG_PARAMS_0(...)
+#define __KARG_PARAMS_1(type, arg, t1, t2, t3, t4, t5, ...)				\
+	__KARG_NAME_TAG(arg, t1, t2, t3, t4, t5)
+#define __KARG_PARAMS_2(type, arg, t1, t2, t3, t4, t5, ...)				\
+	__KARG_NAME_TAG(arg, t1, t2, t3, t4, t5), __KARG_PARAMS_1(__VA_ARGS__)
+#define __KARG_PARAMS_3(type, arg, t1, t2, t3, t4, t5, ...)				\
+	__KARG_NAME_TAG(arg, t1, t2, t3, t4, t5), __KARG_PARAMS_2(__VA_ARGS__)
+#define __KARG_PARAMS_4(type, arg, t1, t2, t3, t4, t5, ...)				\
+	__KARG_NAME_TAG(arg, t1, t2, t3, t4, t5), __KARG_PARAMS_3(__VA_ARGS__)
+#define __KARG_PARAMS_5(type, arg, t1, t2, t3, t4, t5, ...)				\
+	__KARG_NAME_TAG(arg, t1, t2, t3, t4, t5), __KARG_PARAMS_4(__VA_ARGS__)
+
+#define __KARG_PARAMS(n, ...) __KARG_PARAMS_##n(__VA_ARGS__)
+
+#define __KFUNC_CALL(n, ret_type, kfunc_name, ...)					\
+static __always_inline ret_type ____##kfunc_name(__KARG_DECL_N_NOTAG(n, ##__VA_ARGS__));\
+ret_type kfunc_name(__KARG_DECL_N_TAG(n, ##__VA_ARGS__))				\
+{											\
+	return ____##kfunc_name(__KARG_PARAMS(n, ##__VA_ARGS__));			\
+}											\
+static __always_inline ret_type ____##kfunc_name(__KARG_DECL_N_NOTAG(n, __VA_ARGS__))
+
+#define KFUNC_CALL_0(...) __KFUNC_CALL(0, __VA_ARGS__)
+#define KFUNC_CALL_1(...) __KFUNC_CALL(1, __VA_ARGS__)
+#define KFUNC_CALL_2(...) __KFUNC_CALL(2, __VA_ARGS__)
+#define KFUNC_CALL_3(...) __KFUNC_CALL(3, __VA_ARGS__)
+#define KFUNC_CALL_4(...) __KFUNC_CALL(4, __VA_ARGS__)
+#define KFUNC_CALL_5(...) __KFUNC_CALL(5, __VA_ARGS__)
+
 enum btf_kfunc_type {
 	BTF_KFUNC_TYPE_CHECK,
 	BTF_KFUNC_TYPE_ACQUIRE,
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 6dbcaab231e8..351782714f38 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -287,6 +287,20 @@ struct btf_verifier_env {
 	enum resolve_mode resolve_mode;
 };
 
+static const int btf_arg_flag[BTF_ARG_MAX] = {
+	[BTF_ARG_NONE]          = 0,
+	/* Types */
+	[BTF_ARG_SIZE]          = 1 << 0,
+	[BTF_ARG_PTR_TO_MEM]    = 1 << 1,
+	[BTF_ARG_PTR_TO_CTX]    = 1 << 2,
+	[BTF_ARG_PTR_TO_BTF_ID] = 1 << 3,
+	[BTF_ARG_RET_PTR_SIZE]  = 1 << 4,
+	/* Modifiers */
+	[BTF_ARG_RET_PTR_NULL]  = 1 << 29,
+	[BTF_ARG_PTR_REF]       = 1 << 30,
+	[BTF_ARG_PTR_NULL]      = 1 << 31,
+};
+
 static const char * const btf_kind_str[NR_BTF_KINDS] = {
 	[BTF_KIND_UNKN]		= "UNKNOWN",
 	[BTF_KIND_INT]		= "INT",
diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c
index bc4d5cd63a94..dbd1dee16024 100644
--- a/net/netfilter/nf_conntrack_bpf.c
+++ b/net/netfilter/nf_conntrack_bpf.c
@@ -130,9 +130,12 @@ __diag_ignore_all("-Wmissing-prototypes",
  * @opts__sz	- Length of the bpf_ct_opts structure
  *		    Must be NF_BPF_CT_OPTS_SZ (12)
  */
-struct nf_conn *
-bpf_xdp_ct_lookup(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple,
-		  u32 tuple__sz, struct bpf_ct_opts *opts, u32 opts__sz)
+KFUNC_CALL_5(struct nf_conn *, bpf_xdp_ct_lookup,
+	     KARG(struct xdp_md *, xdp_ctx, PTR_TO_CTX),
+	     KARG(struct bpf_sock_tuple *, bpf_tuple, PTR_TO_MEM),
+	     KARG(u32, tuple__sz, SIZE),
+	     KARG(struct bpf_ct_opts *, opts, PTR_TO_MEM),
+	     KARG(u32, opts__sz, SIZE))
 {
 	struct xdp_buff *ctx = (struct xdp_buff *)xdp_ctx;
 	struct net *caller_net;
@@ -173,9 +176,12 @@ bpf_xdp_ct_lookup(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple,
  * @opts__sz	- Length of the bpf_ct_opts structure
  *		    Must be NF_BPF_CT_OPTS_SZ (12)
  */
-struct nf_conn *
-bpf_skb_ct_lookup(struct __sk_buff *skb_ctx, struct bpf_sock_tuple *bpf_tuple,
-		  u32 tuple__sz, struct bpf_ct_opts *opts, u32 opts__sz)
+KFUNC_CALL_5(struct nf_conn *, bpf_skb_ct_lookup,
+	     KARG(struct __sk_buff *, skb_ctx, PTR_TO_CTX),
+	     KARG(struct bpf_sock_tuple *, bpf_tuple, PTR_TO_MEM),
+	     KARG(u32, tuple__sz, SIZE),
+	     KARG(struct bpf_ct_opts *, opts, PTR_TO_MEM),
+	     KARG(u32, opts__sz, SIZE))
 {
 	struct sk_buff *skb = (struct sk_buff *)skb_ctx;
 	struct net *caller_net;
@@ -210,7 +216,8 @@ bpf_skb_ct_lookup(struct __sk_buff *skb_ctx, struct bpf_sock_tuple *bpf_tuple,
  * @nf_conn	 - Pointer to referenced nf_conn object, obtained using
  *		   bpf_xdp_ct_lookup or bpf_skb_ct_lookup.
  */
-void bpf_ct_release(struct nf_conn *nfct)
+KFUNC_CALL_1(void, bpf_ct_release,
+	     KARG(struct nf_conn *, nfct, PTR_TO_BTF_ID, PTR_NULL))
 {
 	if (!nfct)
 		return;