libbpf: Extract common user-facing helpers (544402d4) · Commits · 戴 / test

tools/lib/bpf/bpf.h

+2 −4

Original line number	Diff line number	Diff line
		@@ -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;

+2 −4

Original line number	Diff line number	Diff line
		@@ -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"

+2 −26

Original line number	Diff line number	Diff line
		@@ -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;

0 → 100644

+38 −0

Original line number	Diff line number	Diff line
		/* 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 */