From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:29 -0800
Subject: libbpf: Extract common user-facing helpers
Patch-mainline: v5.6-rc1
Git-commit: 544402d4b49332a4a9b2b8fff20f9d9f5ef86559
References: bsc#1177028
LIBBPF_API and DECLARE_LIBBPF_OPTS are needed in many public libbpf API
headers. Extract them into libbpf_common.h to avoid unnecessary
interdependency between btf.h, libbpf.h, and bpf.h or code duplication.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-6-andriin@fb.com
Acked-by: Gary Lin <glin@suse.com>
---
tools/lib/bpf/bpf.h | 6 ++----
tools/lib/bpf/btf.h | 6 ++----
tools/lib/bpf/libbpf.h | 28 ++--------------------------
tools/lib/bpf/libbpf_common.h | 38 ++++++++++++++++++++++++++++++++++++++
4 files changed, 44 insertions(+), 34 deletions(-)
create mode 100644 tools/lib/bpf/libbpf_common.h
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -28,14 +28,12 @@
#include <stddef.h>
#include <stdint.h>
+#include "libbpf_common.h"
+
#ifdef __cplusplus
extern "C" {
#endif
-#ifndef LIBBPF_API
-#define LIBBPF_API __attribute__((visibility("default")))
-#endif
-
struct bpf_create_map_attr {
const char *name;
enum bpf_map_type map_type;
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -8,14 +8,12 @@
#include <linux/btf.h>
#include <linux/types.h>
+#include "libbpf_common.h"
+
#ifdef __cplusplus
extern "C" {
#endif
-#ifndef LIBBPF_API
-#define LIBBPF_API __attribute__((visibility("default")))
-#endif
-
#define BTF_ELF_SEC ".BTF"
#define BTF_EXT_ELF_SEC ".BTF.ext"
#define MAPS_ELF_SEC ".maps"
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -17,14 +17,12 @@
#include <sys/types.h> // for size_t
#include <linux/bpf.h>
+#include "libbpf_common.h"
+
#ifdef __cplusplus
extern "C" {
#endif
-#ifndef LIBBPF_API
-#define LIBBPF_API __attribute__((visibility("default")))
-#endif
-
enum libbpf_errno {
__LIBBPF_ERRNO__START = 4000,
@@ -67,28 +65,6 @@ struct bpf_object_open_attr {
enum bpf_prog_type prog_type;
};
-/* Helper macro to declare and initialize libbpf options struct
- *
- * This dance with uninitialized declaration, followed by memset to zero,
- * followed by assignment using compound literal syntax is done to preserve
- * ability to use a nice struct field initialization syntax and **hopefully**
- * have all the padding bytes initialized to zero. It's not guaranteed though,
- * when copying literal, that compiler won't copy garbage in literal's padding
- * bytes, but that's the best way I've found and it seems to work in practice.
- *
- * Macro declares opts struct of given type and name, zero-initializes,
- * including any extra padding, it with memset() and then assigns initial
- * values provided by users in struct initializer-syntax as varargs.
- */
-#define DECLARE_LIBBPF_OPTS(TYPE, NAME, ...) \
- struct TYPE NAME = ({ \
- memset(&NAME, 0, sizeof(struct TYPE)); \
- (struct TYPE) { \
- .sz = sizeof(struct TYPE), \
- __VA_ARGS__ \
- }; \
- })
-
struct bpf_object_open_opts {
/* size of this struct, for forward/backward compatiblity */
size_t sz;
--- /dev/null
+++ b/tools/lib/bpf/libbpf_common.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+/*
+ * Common user-facing libbpf helpers.
+ *
+ * Copyright (c) 2019 Facebook
+ */
+
+#ifndef __LIBBPF_LIBBPF_COMMON_H
+#define __LIBBPF_LIBBPF_COMMON_H
+
+#ifndef LIBBPF_API
+#define LIBBPF_API __attribute__((visibility("default")))
+#endif
+
+/* Helper macro to declare and initialize libbpf options struct
+ *
+ * This dance with uninitialized declaration, followed by memset to zero,
+ * followed by assignment using compound literal syntax is done to preserve
+ * ability to use a nice struct field initialization syntax and **hopefully**
+ * have all the padding bytes initialized to zero. It's not guaranteed though,
+ * when copying literal, that compiler won't copy garbage in literal's padding
+ * bytes, but that's the best way I've found and it seems to work in practice.
+ *
+ * Macro declares opts struct of given type and name, zero-initializes,
+ * including any extra padding, it with memset() and then assigns initial
+ * values provided by users in struct initializer-syntax as varargs.
+ */
+#define DECLARE_LIBBPF_OPTS(TYPE, NAME, ...) \
+ struct TYPE NAME = ({ \
+ memset(&NAME, 0, sizeof(struct TYPE)); \
+ (struct TYPE) { \
+ .sz = sizeof(struct TYPE), \
+ __VA_ARGS__ \
+ }; \
+ })
+
+#endif /* __LIBBPF_LIBBPF_COMMON_H */