[PATCH RFC bpf-next 03/10] bpf: Add proto of bpf_core_apply_relo()

[Alexei Starovoitov <alexei.starovoitov@gmail.com>]

From: Alexei Starovoitov <ast@kernel.org>

Prototype of bpf_core_apply_relo() helper.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 include/linux/bpf.h            |  1 +
 include/uapi/linux/bpf.h       | 14 ++++++++++++++
 kernel/bpf/btf.c               | 22 ++++++++++++++++++++++
 kernel/bpf/syscall.c           |  2 ++
 tools/include/uapi/linux/bpf.h | 14 ++++++++++++++
 5 files changed, 53 insertions(+)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index b6c45a6cbbba..a3cb8ea272f7 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2102,6 +2102,7 @@ extern const struct bpf_func_proto bpf_for_each_map_elem_proto;
 extern const struct bpf_func_proto bpf_btf_find_by_name_kind_proto;
 extern const struct bpf_func_proto bpf_sk_setsockopt_proto;
 extern const struct bpf_func_proto bpf_sk_getsockopt_proto;
+extern const struct bpf_func_proto bpf_core_apply_relo_proto;
 
 const struct bpf_func_proto *tracing_prog_func_proto(
   enum bpf_func_id func_id, const struct bpf_prog *prog);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 8fb61f22b72c..c2b8857b8a1c 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -4909,6 +4909,13 @@ union bpf_attr {
  *	Return
  *		The number of bytes written to the buffer, or a negative error
  *		in case of failure.
+ *
+ * long bpf_core_apply_relo(int btf_fd, struct bpf_core_relo_desc *relo, int relo_sz,
+ *			    struct bpf_insn *insn, int flags)
+ * 	Description
+ * 		Apply given relo.
+ * 	Return
+ * 		Returns 0 on success.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -5089,6 +5096,7 @@ union bpf_attr {
 	FN(task_pt_regs),		\
 	FN(get_branch_snapshot),	\
 	FN(trace_vprintk),		\
+	FN(core_apply_relo),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
@@ -6313,4 +6321,10 @@ enum bpf_core_relo_kind {
 	BPF_CORE_ENUMVAL_VALUE = 11,         /* enum value integer value */
 };
 
+struct bpf_core_relo_desc {
+	__u32 type_id;
+	__u32 access_str_off;
+	enum bpf_core_relo_kind kind;
+};
+
 #endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index fa2c88f6ac4a..9bb1247346ce 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -6369,3 +6369,25 @@ size_t bpf_core_essential_name_len(const char *name)
 	}
 	return n;
 }
+
+BPF_CALL_5(bpf_core_apply_relo, int, btf_fd, struct bpf_core_relo_desc *, relo,
+	   int, relo_sz, void *, insn, int, flags)
+{
+	struct btf *btf;
+	long ret;
+
+	if (flags)
+		return -EINVAL;
+	return -EOPNOTSUPP;
+}
+
+const struct bpf_func_proto bpf_core_apply_relo_proto = {
+	.func		= bpf_core_apply_relo,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_ANYTHING,
+	.arg2_type	= ARG_PTR_TO_MEM,
+	.arg3_type	= ARG_CONST_SIZE,
+	.arg4_type	= ARG_PTR_TO_LONG,
+	.arg5_type	= ARG_ANYTHING,
+};
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 4e50c0bfdb7d..3c349b244a28 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -4763,6 +4763,8 @@ syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_btf_find_by_name_kind_proto;
 	case BPF_FUNC_sys_close:
 		return &bpf_sys_close_proto;
+	case BPF_FUNC_core_apply_relo:
+		return &bpf_core_apply_relo_proto;
 	default:
 		return tracing_prog_func_proto(func_id, prog);
 	}
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 8fb61f22b72c..c2b8857b8a1c 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -4909,6 +4909,13 @@ union bpf_attr {
  *	Return
  *		The number of bytes written to the buffer, or a negative error
  *		in case of failure.
+ *
+ * long bpf_core_apply_relo(int btf_fd, struct bpf_core_relo_desc *relo, int relo_sz,
+ *			    struct bpf_insn *insn, int flags)
+ * 	Description
+ * 		Apply given relo.
+ * 	Return
+ * 		Returns 0 on success.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -5089,6 +5096,7 @@ union bpf_attr {
 	FN(task_pt_regs),		\
 	FN(get_branch_snapshot),	\
 	FN(trace_vprintk),		\
+	FN(core_apply_relo),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
@@ -6313,4 +6321,10 @@ enum bpf_core_relo_kind {
 	BPF_CORE_ENUMVAL_VALUE = 11,         /* enum value integer value */
 };
 
+struct bpf_core_relo_desc {
+	__u32 type_id;
+	__u32 access_str_off;
+	enum bpf_core_relo_kind kind;
+};
+
 #endif /* _UAPI__LINUX_BPF_H__ */
-- 
2.30.2