perf ebpf: Add the libbpf glue

/*

 * bpf-loader.c

 *

 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>

 * Copyright (C) 2015 Huawei Inc.

 */

#include <bpf/libbpf.h>

#include <linux/err.h>

#include "perf.h"

#include "debug.h"

#include "bpf-loader.h"

#define DEFINE_PRINT_FN(name, level) \

static int libbpf_##name(const char *fmt, ...)	\

{						\

	va_list args;				\

	int ret;				\

						\

	va_start(args, fmt);			\

	ret = veprintf(level, verbose, pr_fmt(fmt), args);\

	va_end(args);				\

	return ret;				\

}

DEFINE_PRINT_FN(warning, 0)

DEFINE_PRINT_FN(info, 0)

DEFINE_PRINT_FN(debug, 1)

struct bpf_object *bpf__prepare_load(const char *filename)

{

	struct bpf_object *obj;

	static bool libbpf_initialized;

	if (!libbpf_initialized) {

		libbpf_set_print(libbpf_warning,

				 libbpf_info,

				 libbpf_debug);

		libbpf_initialized = true;

	}

	obj = bpf_object__open(filename);

	if (!obj) {

		pr_debug("bpf: failed to load %s\n", filename);

		return ERR_PTR(-EINVAL);

	}

	return obj;

}

void bpf__clear(void)

{

	struct bpf_object *obj, *tmp;

	bpf_object__for_each_safe(obj, tmp)

		bpf_object__close(obj);

}

/*

 * Copyright (C) 2015, Wang Nan <wangnan0@huawei.com>

 * Copyright (C) 2015, Huawei Inc.

 */

#ifndef __BPF_LOADER_H

#define __BPF_LOADER_H

#include <linux/compiler.h>

#include <linux/err.h>

#include <string.h>

#include "debug.h"

struct bpf_object;

#ifdef HAVE_LIBBPF_SUPPORT

struct bpf_object *bpf__prepare_load(const char *filename);

void bpf__clear(void);

#else

static inline struct bpf_object *

bpf__prepare_load(const char *filename __maybe_unused)

{

	pr_debug("ERROR: eBPF object loading is disabled during compiling.\n");

	return ERR_PTR(-ENOTSUP);

}

static inline void bpf__clear(void) { }

#endif

#endif