[deliverable/linux.git] / tools / lib / bpf / libbpf.c

/*
 * Common eBPF ELF object loading operations.
 *
 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
 * Copyright (C) 2015 Huawei Inc.
 */

#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <inttypes.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <asm/unistd.h>
#include <linux/kernel.h>
#include <linux/bpf.h>
#include <libelf.h>
#include <gelf.h>

#include "libbpf.h"
#include "bpf.h"

#define __printf(a, b)	__attribute__((format(printf, a, b)))

__printf(1, 2)
static int __base_pr(const char *format, ...)
{
	va_list args;
	int err;

	va_start(args, format);
	err = vfprintf(stderr, format, args);
	va_end(args);
	return err;
}

static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr;
static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr;
static __printf(1, 2) libbpf_print_fn_t __pr_debug;

#define __pr(func, fmt, ...)	\
do {				\
	if ((func))		\
		(func)("libbpf: " fmt, ##__VA_ARGS__); \
} while (0)

#define pr_warning(fmt, ...)	__pr(__pr_warning, fmt, ##__VA_ARGS__)
#define pr_info(fmt, ...)	__pr(__pr_info, fmt, ##__VA_ARGS__)
#define pr_debug(fmt, ...)	__pr(__pr_debug, fmt, ##__VA_ARGS__)

void libbpf_set_print(libbpf_print_fn_t warn,
		      libbpf_print_fn_t info,
		      libbpf_print_fn_t debug)
{
	__pr_warning = warn;
	__pr_info = info;
	__pr_debug = debug;
}

/* Copied from tools/perf/util/util.h */
#ifndef zfree
# define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
#endif

#ifndef zclose
# define zclose(fd) ({			\
	int ___err = 0;			\
	if ((fd) >= 0)			\
		___err = close((fd));	\
	fd = -1;			\
	___err; })
#endif

#ifdef HAVE_LIBELF_MMAP_SUPPORT
# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP
#else
# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
#endif

/*
 * bpf_prog should be a better name but it has been used in
 * linux/filter.h.
 */
struct bpf_program {
	/* Index in elf obj file, for relocation use. */
	int idx;
	char *section_name;
	struct bpf_insn *insns;
	size_t insns_cnt;

	struct {
		int insn_idx;
		int map_idx;
	} *reloc_desc;
	int nr_reloc;
};

struct bpf_object {
	char license[64];
	u32 kern_version;
	void *maps_buf;
	size_t maps_buf_sz;

	struct bpf_program *programs;
	size_t nr_programs;
	int *map_fds;
	/*
	 * This field is required because maps_buf will be freed and
	 * maps_buf_sz will be set to 0 after loaded.
	 */
	size_t nr_map_fds;
	bool loaded;

	/*
	 * Information when doing elf related work. Only valid if fd
	 * is valid.
	 */
	struct {
		int fd;
		void *obj_buf;
		size_t obj_buf_sz;
		Elf *elf;
		GElf_Ehdr ehdr;
		Elf_Data *symbols;
		struct {
			GElf_Shdr shdr;
			Elf_Data *data;
		} *reloc;
		int nr_reloc;
	} efile;
	char path[];
};
#define obj_elf_valid(o)	((o)->efile.elf)

static void bpf_program__exit(struct bpf_program *prog)
{
	if (!prog)
		return;

	zfree(&prog->section_name);
	zfree(&prog->insns);
	zfree(&prog->reloc_desc);

	prog->nr_reloc = 0;
	prog->insns_cnt = 0;
	prog->idx = -1;
}

static int
bpf_program__init(void *data, size_t size, char *name, int idx,
		    struct bpf_program *prog)
{
	if (size < sizeof(struct bpf_insn)) {
		pr_warning("corrupted section '%s'\n", name);
		return -EINVAL;
	}

	bzero(prog, sizeof(*prog));

	prog->section_name = strdup(name);
	if (!prog->section_name) {
		pr_warning("failed to alloc name for prog %s\n",
			   name);
		goto errout;
	}

	prog->insns = malloc(size);
	if (!prog->insns) {
		pr_warning("failed to alloc insns for %s\n", name);
		goto errout;
	}
	prog->insns_cnt = size / sizeof(struct bpf_insn);
	memcpy(prog->insns, data,
	       prog->insns_cnt * sizeof(struct bpf_insn));
	prog->idx = idx;

	return 0;
errout:
	bpf_program__exit(prog);
	return -ENOMEM;
}

static int
bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
			char *name, int idx)
{
	struct bpf_program prog, *progs;
	int nr_progs, err;

	err = bpf_program__init(data, size, name, idx, &prog);
	if (err)
		return err;

	progs = obj->programs;
	nr_progs = obj->nr_programs;

	progs = realloc(progs, sizeof(progs[0]) * (nr_progs + 1));
	if (!progs) {
		/*
		 * In this case the original obj->programs
		 * is still valid, so don't need special treat for
		 * bpf_close_object().
		 */
		pr_warning("failed to alloc a new program '%s'\n",
			   name);
		bpf_program__exit(&prog);
		return -ENOMEM;
	}

	pr_debug("found program %s\n", prog.section_name);
	obj->programs = progs;
	obj->nr_programs = nr_progs + 1;
	progs[nr_progs] = prog;
	return 0;
}

static struct bpf_object *bpf_object__new(const char *path,
					  void *obj_buf,
					  size_t obj_buf_sz)
{
	struct bpf_object *obj;

	obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
	if (!obj) {
		pr_warning("alloc memory failed for %s\n", path);
		return NULL;
	}

	strcpy(obj->path, path);
	obj->efile.fd = -1;

	/*
	 * Caller of this function should also calls
	 * bpf_object__elf_finish() after data collection to return
	 * obj_buf to user. If not, we should duplicate the buffer to
	 * avoid user freeing them before elf finish.
	 */
	obj->efile.obj_buf = obj_buf;
	obj->efile.obj_buf_sz = obj_buf_sz;

	obj->loaded = false;
	return obj;
}

static void bpf_object__elf_finish(struct bpf_object *obj)
{
	if (!obj_elf_valid(obj))
		return;

	if (obj->efile.elf) {
		elf_end(obj->efile.elf);
		obj->efile.elf = NULL;
	}
	obj->efile.symbols = NULL;

	zfree(&obj->efile.reloc);
	obj->efile.nr_reloc = 0;
	zclose(obj->efile.fd);
	obj->efile.obj_buf = NULL;
	obj->efile.obj_buf_sz = 0;
}

static int bpf_object__elf_init(struct bpf_object *obj)
{
	int err = 0;
	GElf_Ehdr *ep;

	if (obj_elf_valid(obj)) {
		pr_warning("elf init: internal error\n");
		return -EEXIST;
	}

	if (obj->efile.obj_buf_sz > 0) {
		/*
		 * obj_buf should have been validated by
		 * bpf_object__open_buffer().
		 */
		obj->efile.elf = elf_memory(obj->efile.obj_buf,
					    obj->efile.obj_buf_sz);
	} else {
		obj->efile.fd = open(obj->path, O_RDONLY);
		if (obj->efile.fd < 0) {
			pr_warning("failed to open %s: %s\n", obj->path,
					strerror(errno));
			return -errno;
		}

		obj->efile.elf = elf_begin(obj->efile.fd,
				LIBBPF_ELF_C_READ_MMAP,
				NULL);
	}

	if (!obj->efile.elf) {
		pr_warning("failed to open %s as ELF file\n",
				obj->path);
		err = -EINVAL;
		goto errout;
	}

	if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
		pr_warning("failed to get EHDR from %s\n",
				obj->path);
		err = -EINVAL;
		goto errout;
	}
	ep = &obj->efile.ehdr;

	if ((ep->e_type != ET_REL) || (ep->e_machine != 0)) {
		pr_warning("%s is not an eBPF object file\n",
			obj->path);
		err = -EINVAL;
		goto errout;
	}

	return 0;
errout:
	bpf_object__elf_finish(obj);
	return err;
}

static int
bpf_object__check_endianness(struct bpf_object *obj)
{
	static unsigned int const endian = 1;

	switch (obj->efile.ehdr.e_ident[EI_DATA]) {
	case ELFDATA2LSB:
		/* We are big endian, BPF obj is little endian. */
		if (*(unsigned char const *)&endian != 1)
			goto mismatch;
		break;

	case ELFDATA2MSB:
		/* We are little endian, BPF obj is big endian. */
		if (*(unsigned char const *)&endian != 0)
			goto mismatch;
		break;
	default:
		return -EINVAL;
	}

	return 0;

mismatch:
	pr_warning("Error: endianness mismatch.\n");
	return -EINVAL;
}

static int
bpf_object__init_license(struct bpf_object *obj,
			 void *data, size_t size)
{
	memcpy(obj->license, data,
	       min(size, sizeof(obj->license) - 1));
	pr_debug("license of %s is %s\n", obj->path, obj->license);
	return 0;
}

static int
bpf_object__init_kversion(struct bpf_object *obj,
			  void *data, size_t size)
{
	u32 kver;

	if (size != sizeof(kver)) {
		pr_warning("invalid kver section in %s\n", obj->path);
		return -EINVAL;
	}
	memcpy(&kver, data, sizeof(kver));
	obj->kern_version = kver;
	pr_debug("kernel version of %s is %x\n", obj->path,
		 obj->kern_version);
	return 0;
}

static int
bpf_object__init_maps(struct bpf_object *obj, void *data,
		      size_t size)
{
	if (size == 0) {
		pr_debug("%s doesn't need map definition\n",
			 obj->path);
		return 0;
	}

	obj->maps_buf = malloc(size);
	if (!obj->maps_buf) {
		pr_warning("malloc maps failed: %s\n", obj->path);
		return -ENOMEM;
	}

	obj->maps_buf_sz = size;
	memcpy(obj->maps_buf, data, size);
	pr_debug("maps in %s: %ld bytes\n", obj->path, (long)size);
	return 0;
}

static int bpf_object__elf_collect(struct bpf_object *obj)
{
	Elf *elf = obj->efile.elf;
	GElf_Ehdr *ep = &obj->efile.ehdr;
	Elf_Scn *scn = NULL;
	int idx = 0, err = 0;

	/* Elf is corrupted/truncated, avoid calling elf_strptr. */
	if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) {
		pr_warning("failed to get e_shstrndx from %s\n",
			   obj->path);
		return -EINVAL;
	}

	while ((scn = elf_nextscn(elf, scn)) != NULL) {
		char *name;
		GElf_Shdr sh;
		Elf_Data *data;

		idx++;
		if (gelf_getshdr(scn, &sh) != &sh) {
			pr_warning("failed to get section header from %s\n",
				   obj->path);
			err = -EINVAL;
			goto out;
		}

		name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
		if (!name) {
			pr_warning("failed to get section name from %s\n",
				   obj->path);
			err = -EINVAL;
			goto out;
		}

		data = elf_getdata(scn, 0);
		if (!data) {
			pr_warning("failed to get section data from %s(%s)\n",
				   name, obj->path);
			err = -EINVAL;
			goto out;
		}
		pr_debug("section %s, size %ld, link %d, flags %lx, type=%d\n",
			 name, (unsigned long)data->d_size,
			 (int)sh.sh_link, (unsigned long)sh.sh_flags,
			 (int)sh.sh_type);

		if (strcmp(name, "license") == 0)
			err = bpf_object__init_license(obj,
						       data->d_buf,
						       data->d_size);
		else if (strcmp(name, "version") == 0)
			err = bpf_object__init_kversion(obj,
							data->d_buf,
							data->d_size);
		else if (strcmp(name, "maps") == 0)
			err = bpf_object__init_maps(obj, data->d_buf,
						    data->d_size);
		else if (sh.sh_type == SHT_SYMTAB) {
			if (obj->efile.symbols) {
				pr_warning("bpf: multiple SYMTAB in %s\n",
					   obj->path);
				err = -EEXIST;
			} else
				obj->efile.symbols = data;
		} else if ((sh.sh_type == SHT_PROGBITS) &&
			   (sh.sh_flags & SHF_EXECINSTR) &&
			   (data->d_size > 0)) {
			err = bpf_object__add_program(obj, data->d_buf,
						      data->d_size, name, idx);
			if (err) {
				char errmsg[128];
				strerror_r(-err, errmsg, sizeof(errmsg));
				pr_warning("failed to alloc program %s (%s): %s",
					   name, obj->path, errmsg);
			}
		} else if (sh.sh_type == SHT_REL) {
			void *reloc = obj->efile.reloc;
			int nr_reloc = obj->efile.nr_reloc + 1;

			reloc = realloc(reloc,
					sizeof(*obj->efile.reloc) * nr_reloc);
			if (!reloc) {
				pr_warning("realloc failed\n");
				err = -ENOMEM;
			} else {
				int n = nr_reloc - 1;

				obj->efile.reloc = reloc;
				obj->efile.nr_reloc = nr_reloc;

				obj->efile.reloc[n].shdr = sh;
				obj->efile.reloc[n].data = data;
			}
		}
		if (err)
			goto out;
	}
out:
	return err;
}

static struct bpf_program *
bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx)
{
	struct bpf_program *prog;
	size_t i;

	for (i = 0; i < obj->nr_programs; i++) {
		prog = &obj->programs[i];
		if (prog->idx == idx)
			return prog;
	}
	return NULL;
}

static int
bpf_program__collect_reloc(struct bpf_program *prog,
			   size_t nr_maps, GElf_Shdr *shdr,
			   Elf_Data *data, Elf_Data *symbols)
{
	int i, nrels;

	pr_debug("collecting relocating info for: '%s'\n",
		 prog->section_name);
	nrels = shdr->sh_size / shdr->sh_entsize;

	prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels);
	if (!prog->reloc_desc) {
		pr_warning("failed to alloc memory in relocation\n");
		return -ENOMEM;
	}
	prog->nr_reloc = nrels;

	for (i = 0; i < nrels; i++) {
		GElf_Sym sym;
		GElf_Rel rel;
		unsigned int insn_idx;
		struct bpf_insn *insns = prog->insns;
		size_t map_idx;

		if (!gelf_getrel(data, i, &rel)) {
			pr_warning("relocation: failed to get %d reloc\n", i);
			return -EINVAL;
		}

		insn_idx = rel.r_offset / sizeof(struct bpf_insn);
		pr_debug("relocation: insn_idx=%u\n", insn_idx);

		if (!gelf_getsym(symbols,
				 GELF_R_SYM(rel.r_info),
				 &sym)) {
			pr_warning("relocation: symbol %"PRIx64" not found\n",
				   GELF_R_SYM(rel.r_info));
			return -EINVAL;
		}

		if (insns[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
			pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n",
				   insn_idx, insns[insn_idx].code);
			return -EINVAL;
		}

		map_idx = sym.st_value / sizeof(struct bpf_map_def);
		if (map_idx >= nr_maps) {
			pr_warning("bpf relocation: map_idx %d large than %d\n",
				   (int)map_idx, (int)nr_maps - 1);
			return -EINVAL;
		}

		prog->reloc_desc[i].insn_idx = insn_idx;
		prog->reloc_desc[i].map_idx = map_idx;
	}
	return 0;
}

static int
bpf_object__create_maps(struct bpf_object *obj)
{
	unsigned int i;
	size_t nr_maps;
	int *pfd;

	nr_maps = obj->maps_buf_sz / sizeof(struct bpf_map_def);
	if (!obj->maps_buf || !nr_maps) {
		pr_debug("don't need create maps for %s\n",
			 obj->path);
		return 0;
	}

	obj->map_fds = malloc(sizeof(int) * nr_maps);
	if (!obj->map_fds) {
		pr_warning("realloc perf_bpf_map_fds failed\n");
		return -ENOMEM;
	}
	obj->nr_map_fds = nr_maps;

	/* fill all fd with -1 */
	memset(obj->map_fds, -1, sizeof(int) * nr_maps);

	pfd = obj->map_fds;
	for (i = 0; i < nr_maps; i++) {
		struct bpf_map_def def;

		def = *(struct bpf_map_def *)(obj->maps_buf +
				i * sizeof(struct bpf_map_def));

		*pfd = bpf_create_map(def.type,
				      def.key_size,
				      def.value_size,
				      def.max_entries);
		if (*pfd < 0) {
			size_t j;
			int err = *pfd;

			pr_warning("failed to create map: %s\n",
				   strerror(errno));
			for (j = 0; j < i; j++)
				zclose(obj->map_fds[j]);
			obj->nr_map_fds = 0;
			zfree(&obj->map_fds);
			return err;
		}
		pr_debug("create map: fd=%d\n", *pfd);
		pfd++;
	}

	zfree(&obj->maps_buf);
	obj->maps_buf_sz = 0;
	return 0;
}

static int
bpf_program__relocate(struct bpf_program *prog, int *map_fds)
{
	int i;

	if (!prog || !prog->reloc_desc)
		return 0;

	for (i = 0; i < prog->nr_reloc; i++) {
		int insn_idx, map_idx;
		struct bpf_insn *insns = prog->insns;

		insn_idx = prog->reloc_desc[i].insn_idx;
		map_idx = prog->reloc_desc[i].map_idx;

		if (insn_idx >= (int)prog->insns_cnt) {
			pr_warning("relocation out of range: '%s'\n",
				   prog->section_name);
			return -ERANGE;
		}
		insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
		insns[insn_idx].imm = map_fds[map_idx];
	}

	zfree(&prog->reloc_desc);
	prog->nr_reloc = 0;
	return 0;
}


static int
bpf_object__relocate(struct bpf_object *obj)
{
	struct bpf_program *prog;
	size_t i;
	int err;

	for (i = 0; i < obj->nr_programs; i++) {
		prog = &obj->programs[i];

		err = bpf_program__relocate(prog, obj->map_fds);
		if (err) {
			pr_warning("failed to relocate '%s'\n",
				   prog->section_name);
			return err;
		}
	}
	return 0;
}

static int bpf_object__collect_reloc(struct bpf_object *obj)
{
	int i, err;

	if (!obj_elf_valid(obj)) {
		pr_warning("Internal error: elf object is closed\n");
		return -EINVAL;
	}

	for (i = 0; i < obj->efile.nr_reloc; i++) {
		GElf_Shdr *shdr = &obj->efile.reloc[i].shdr;
		Elf_Data *data = obj->efile.reloc[i].data;
		int idx = shdr->sh_info;
		struct bpf_program *prog;
		size_t nr_maps = obj->maps_buf_sz /
				 sizeof(struct bpf_map_def);

		if (shdr->sh_type != SHT_REL) {
			pr_warning("internal error at %d\n", __LINE__);
			return -EINVAL;
		}

		prog = bpf_object__find_prog_by_idx(obj, idx);
		if (!prog) {
			pr_warning("relocation failed: no %d section\n",
				   idx);
			return -ENOENT;
		}

		err = bpf_program__collect_reloc(prog, nr_maps,
						 shdr, data,
						 obj->efile.symbols);
		if (err)
			return -EINVAL;
	}
	return 0;
}

static int bpf_object__validate(struct bpf_object *obj)
{
	if (obj->kern_version == 0) {
		pr_warning("%s doesn't provide kernel version\n",
			   obj->path);
		return -EINVAL;
	}
	return 0;
}

static struct bpf_object *
__bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz)
{
	struct bpf_object *obj;

	if (elf_version(EV_CURRENT) == EV_NONE) {
		pr_warning("failed to init libelf for %s\n", path);
		return NULL;
	}

	obj = bpf_object__new(path, obj_buf, obj_buf_sz);
	if (!obj)
		return NULL;

	if (bpf_object__elf_init(obj))
		goto out;
	if (bpf_object__check_endianness(obj))
		goto out;
	if (bpf_object__elf_collect(obj))
		goto out;
	if (bpf_object__collect_reloc(obj))
		goto out;
	if (bpf_object__validate(obj))
		goto out;

	bpf_object__elf_finish(obj);
	return obj;
out:
	bpf_object__close(obj);
	return NULL;
}

struct bpf_object *bpf_object__open(const char *path)
{
	/* param validation */
	if (!path)
		return NULL;

	pr_debug("loading %s\n", path);

	return __bpf_object__open(path, NULL, 0);
}

struct bpf_object *bpf_object__open_buffer(void *obj_buf,
					   size_t obj_buf_sz)
{
	/* param validation */
	if (!obj_buf || obj_buf_sz <= 0)
		return NULL;

	pr_debug("loading object from buffer\n");

	return __bpf_object__open("[buffer]", obj_buf, obj_buf_sz);
}

int bpf_object__unload(struct bpf_object *obj)
{
	size_t i;

	if (!obj)
		return -EINVAL;

	for (i = 0; i < obj->nr_map_fds; i++)
		zclose(obj->map_fds[i]);
	zfree(&obj->map_fds);
	obj->nr_map_fds = 0;

	return 0;
}

int bpf_object__load(struct bpf_object *obj)
{
	if (!obj)
		return -EINVAL;

	if (obj->loaded) {
		pr_warning("object should not be loaded twice\n");
		return -EINVAL;
	}

	obj->loaded = true;
	if (bpf_object__create_maps(obj))
		goto out;
	if (bpf_object__relocate(obj))
		goto out;

	return 0;
out:
	bpf_object__unload(obj);
	pr_warning("failed to load object '%s'\n", obj->path);
	return -EINVAL;
}

void bpf_object__close(struct bpf_object *obj)
{
	size_t i;

	if (!obj)
		return;

	bpf_object__elf_finish(obj);
	bpf_object__unload(obj);

	zfree(&obj->maps_buf);

	if (obj->programs && obj->nr_programs) {
		for (i = 0; i < obj->nr_programs; i++)
			bpf_program__exit(&obj->programs[i]);
	}
	zfree(&obj->programs);

	free(obj);
}
Commit	Line	Data
1b76c13e WN	1	/*
	2	* Common eBPF ELF object loading operations.
	3	*
	4	* Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
	5	* Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
	6	* Copyright (C) 2015 Huawei Inc.
	7	*/
	8
	9	#include <stdlib.h>
b3f59d66 WN	10	#include <stdio.h>
b3f59d66 WN	11	#include <stdarg.h>
34090915	12	#include <inttypes.h>
b3f59d66	13	#include <string.h>
1b76c13e	14	#include <unistd.h>
1a5e3fb1 WN	15	#include <fcntl.h>
1a5e3fb1 WN	16	#include <errno.h>
1b76c13e	17	#include <asm/unistd.h>
cb1e5e96	18	#include <linux/kernel.h>
1b76c13e	19	#include <linux/bpf.h>
1a5e3fb1 WN	20	#include <libelf.h>
1a5e3fb1 WN	21	#include <gelf.h>
1b76c13e WN	22
1b76c13e WN	23	#include "libbpf.h"
52d3352e	24	#include "bpf.h"
b3f59d66 WN	25
	26	#define __printf(a, b) __attribute__((format(printf, a, b)))
	27
	28	__printf(1, 2)
	29	static int __base_pr(const char *format, ...)
	30	{
	31	va_list args;
	32	int err;
	33
	34	va_start(args, format);
	35	err = vfprintf(stderr, format, args);
	36	va_end(args);
	37	return err;
	38	}
	39
	40	static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr;
	41	static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr;
	42	static __printf(1, 2) libbpf_print_fn_t __pr_debug;
	43
	44	#define __pr(func, fmt, ...) \
	45	do { \
	46	if ((func)) \
	47	(func)("libbpf: " fmt, ##__VA_ARGS__); \
	48	} while (0)
	49
	50	#define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__)
	51	#define pr_info(fmt, ...) __pr(__pr_info, fmt, ##__VA_ARGS__)
	52	#define pr_debug(fmt, ...) __pr(__pr_debug, fmt, ##__VA_ARGS__)
	53
	54	void libbpf_set_print(libbpf_print_fn_t warn,
	55	libbpf_print_fn_t info,
	56	libbpf_print_fn_t debug)
	57	{
	58	__pr_warning = warn;
	59	__pr_info = info;
	60	__pr_debug = debug;
	61	}
1a5e3fb1 WN	62
	63	/* Copied from tools/perf/util/util.h */
	64	#ifndef zfree
	65	# define zfree(ptr) ({ free(ptr); ptr = NULL; })
	66	#endif
	67
	68	#ifndef zclose
	69	# define zclose(fd) ({ \
	70	int ___err = 0; \
	71	if ((fd) >= 0) \
	72	___err = close((fd)); \
	73	fd = -1; \
	74	___err; })
	75	#endif
	76
	77	#ifdef HAVE_LIBELF_MMAP_SUPPORT
	78	# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP
	79	#else
	80	# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
	81	#endif
	82
a5b8bd47 WN	83	/*
	84	* bpf_prog should be a better name but it has been used in
	85	* linux/filter.h.
	86	*/
	87	struct bpf_program {
	88	/* Index in elf obj file, for relocation use. */
	89	int idx;
	90	char *section_name;
	91	struct bpf_insn *insns;
	92	size_t insns_cnt;
34090915 WN	93
	94	struct {
	95	int insn_idx;
	96	int map_idx;
	97	} *reloc_desc;
	98	int nr_reloc;
a5b8bd47 WN	99	};
a5b8bd47 WN	100
1a5e3fb1	101	struct bpf_object {
cb1e5e96 WN	102	char license[64];
cb1e5e96 WN	103	u32 kern_version;
0b3d1efa WN	104	void *maps_buf;
	105	size_t maps_buf_sz;
	106
a5b8bd47 WN	107	struct bpf_program *programs;
a5b8bd47 WN	108	size_t nr_programs;
52d3352e WN	109	int *map_fds;
	110	/*
	111	* This field is required because maps_buf will be freed and
	112	* maps_buf_sz will be set to 0 after loaded.
	113	*/
	114	size_t nr_map_fds;
	115	bool loaded;
a5b8bd47	116
1a5e3fb1 WN	117	/*
	118	* Information when doing elf related work. Only valid if fd
	119	* is valid.
	120	*/
	121	struct {
	122	int fd;
6c956392 WN	123	void *obj_buf;
6c956392 WN	124	size_t obj_buf_sz;
1a5e3fb1 WN	125	Elf *elf;
1a5e3fb1 WN	126	GElf_Ehdr ehdr;
bec7d68c	127	Elf_Data *symbols;
b62f06e8 WN	128	struct {
	129	GElf_Shdr shdr;
	130	Elf_Data *data;
	131	} *reloc;
	132	int nr_reloc;
1a5e3fb1 WN	133	} efile;
	134	char path[];
	135	};
	136	#define obj_elf_valid(o) ((o)->efile.elf)
	137
a5b8bd47 WN	138	static void bpf_program__exit(struct bpf_program *prog)
	139	{
	140	if (!prog)
	141	return;
	142
	143	zfree(&prog->section_name);
	144	zfree(&prog->insns);
34090915 WN	145	zfree(&prog->reloc_desc);
	146
	147	prog->nr_reloc = 0;
a5b8bd47 WN	148	prog->insns_cnt = 0;
	149	prog->idx = -1;
	150	}
	151
	152	static int
	153	bpf_program__init(void data, size_t size, char name, int idx,
	154	struct bpf_program *prog)
	155	{
	156	if (size < sizeof(struct bpf_insn)) {
	157	pr_warning("corrupted section '%s'\n", name);
	158	return -EINVAL;
	159	}
	160
	161	bzero(prog, sizeof(*prog));
	162
	163	prog->section_name = strdup(name);
	164	if (!prog->section_name) {
	165	pr_warning("failed to alloc name for prog %s\n",
	166	name);
	167	goto errout;
	168	}
	169
	170	prog->insns = malloc(size);
	171	if (!prog->insns) {
	172	pr_warning("failed to alloc insns for %s\n", name);
	173	goto errout;
	174	}
	175	prog->insns_cnt = size / sizeof(struct bpf_insn);
	176	memcpy(prog->insns, data,
	177	prog->insns_cnt * sizeof(struct bpf_insn));
	178	prog->idx = idx;
	179
	180	return 0;
	181	errout:
	182	bpf_program__exit(prog);
	183	return -ENOMEM;
	184	}
	185
	186	static int
	187	bpf_object__add_program(struct bpf_object obj, void data, size_t size,
	188	char *name, int idx)
	189	{
	190	struct bpf_program prog, *progs;
	191	int nr_progs, err;
	192
	193	err = bpf_program__init(data, size, name, idx, &prog);
	194	if (err)
	195	return err;
	196
	197	progs = obj->programs;
	198	nr_progs = obj->nr_programs;
	199
	200	progs = realloc(progs, sizeof(progs[0]) * (nr_progs + 1));
	201	if (!progs) {
	202	/*
	203	* In this case the original obj->programs
	204	* is still valid, so don't need special treat for
	205	* bpf_close_object().
	206	*/
	207	pr_warning("failed to alloc a new program '%s'\n",
	208	name);
	209	bpf_program__exit(&prog);
	210	return -ENOMEM;
	211	}
212
213	pr_debug("found program %s\n", prog.section_name);
214	obj->programs = progs;
215	obj->nr_programs = nr_progs + 1;
216	progs[nr_progs] = prog;
217	return 0;
218	}
219
6c956392 WN	220	static struct bpf_object bpf_object__new(const char path,
	221	void *obj_buf,
	222	size_t obj_buf_sz)
1a5e3fb1 WN	223	{
	224	struct bpf_object *obj;
	225
	226	obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
	227	if (!obj) {
	228	pr_warning("alloc memory failed for %s\n", path);
	229	return NULL;
	230	}
	231
	232	strcpy(obj->path, path);
	233	obj->efile.fd = -1;
6c956392 WN	234
	235	/*
	236	* Caller of this function should also calls
	237	* bpf_object__elf_finish() after data collection to return
	238	* obj_buf to user. If not, we should duplicate the buffer to
	239	* avoid user freeing them before elf finish.
	240	*/
	241	obj->efile.obj_buf = obj_buf;
	242	obj->efile.obj_buf_sz = obj_buf_sz;
	243
52d3352e	244	obj->loaded = false;
1a5e3fb1 WN	245	return obj;
	246	}
	247
	248	static void bpf_object__elf_finish(struct bpf_object *obj)
	249	{
	250	if (!obj_elf_valid(obj))
	251	return;
	252
	253	if (obj->efile.elf) {
	254	elf_end(obj->efile.elf);
	255	obj->efile.elf = NULL;
	256	}
bec7d68c	257	obj->efile.symbols = NULL;
b62f06e8 WN	258
	259	zfree(&obj->efile.reloc);
	260	obj->efile.nr_reloc = 0;
1a5e3fb1	261	zclose(obj->efile.fd);
6c956392 WN	262	obj->efile.obj_buf = NULL;
6c956392 WN	263	obj->efile.obj_buf_sz = 0;
1a5e3fb1 WN	264	}
	265
	266	static int bpf_object__elf_init(struct bpf_object *obj)
	267	{
	268	int err = 0;
	269	GElf_Ehdr *ep;
	270
	271	if (obj_elf_valid(obj)) {
	272	pr_warning("elf init: internal error\n");
	273	return -EEXIST;
	274	}
	275
6c956392 WN	276	if (obj->efile.obj_buf_sz > 0) {
	277	/*
	278	* obj_buf should have been validated by
	279	* bpf_object__open_buffer().
	280	*/
	281	obj->efile.elf = elf_memory(obj->efile.obj_buf,
	282	obj->efile.obj_buf_sz);
	283	} else {
	284	obj->efile.fd = open(obj->path, O_RDONLY);
	285	if (obj->efile.fd < 0) {
	286	pr_warning("failed to open %s: %s\n", obj->path,
	287	strerror(errno));
	288	return -errno;
	289	}
	290
	291	obj->efile.elf = elf_begin(obj->efile.fd,
	292	LIBBPF_ELF_C_READ_MMAP,
	293	NULL);
1a5e3fb1 WN	294	}
1a5e3fb1 WN	295
1a5e3fb1 WN	296	if (!obj->efile.elf) {
	297	pr_warning("failed to open %s as ELF file\n",
	298	obj->path);
	299	err = -EINVAL;
	300	goto errout;
	301	}
	302
	303	if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
	304	pr_warning("failed to get EHDR from %s\n",
	305	obj->path);
	306	err = -EINVAL;
	307	goto errout;
	308	}
	309	ep = &obj->efile.ehdr;
	310
	311	if ((ep->e_type != ET_REL) \|\| (ep->e_machine != 0)) {
	312	pr_warning("%s is not an eBPF object file\n",
	313	obj->path);
	314	err = -EINVAL;
	315	goto errout;
	316	}
	317
	318	return 0;
	319	errout:
	320	bpf_object__elf_finish(obj);
	321	return err;
	322	}
	323
cc4228d5 WN	324	static int
	325	bpf_object__check_endianness(struct bpf_object *obj)
	326	{
	327	static unsigned int const endian = 1;
	328
	329	switch (obj->efile.ehdr.e_ident[EI_DATA]) {
	330	case ELFDATA2LSB:
	331	/* We are big endian, BPF obj is little endian. */
	332	if ((unsigned char const )&endian != 1)
	333	goto mismatch;
	334	break;
	335
	336	case ELFDATA2MSB:
	337	/* We are little endian, BPF obj is big endian. */
	338	if ((unsigned char const )&endian != 0)
	339	goto mismatch;
	340	break;
	341	default:
	342	return -EINVAL;
	343	}
	344
	345	return 0;
	346
	347	mismatch:
	348	pr_warning("Error: endianness mismatch.\n");
	349	return -EINVAL;
	350	}
	351
cb1e5e96 WN	352	static int
	353	bpf_object__init_license(struct bpf_object *obj,
	354	void *data, size_t size)
	355	{
	356	memcpy(obj->license, data,
	357	min(size, sizeof(obj->license) - 1));
	358	pr_debug("license of %s is %s\n", obj->path, obj->license);
	359	return 0;
	360	}
	361
	362	static int
	363	bpf_object__init_kversion(struct bpf_object *obj,
	364	void *data, size_t size)
	365	{
	366	u32 kver;
	367
	368	if (size != sizeof(kver)) {
	369	pr_warning("invalid kver section in %s\n", obj->path);
	370	return -EINVAL;
	371	}
	372	memcpy(&kver, data, sizeof(kver));
	373	obj->kern_version = kver;
	374	pr_debug("kernel version of %s is %x\n", obj->path,
	375	obj->kern_version);
	376	return 0;
	377	}
	378
0b3d1efa WN	379	static int
	380	bpf_object__init_maps(struct bpf_object obj, void data,
	381	size_t size)
	382	{
	383	if (size == 0) {
	384	pr_debug("%s doesn't need map definition\n",
	385	obj->path);
	386	return 0;
	387	}
	388
	389	obj->maps_buf = malloc(size);
	390	if (!obj->maps_buf) {
	391	pr_warning("malloc maps failed: %s\n", obj->path);
	392	return -ENOMEM;
	393	}
	394
	395	obj->maps_buf_sz = size;
	396	memcpy(obj->maps_buf, data, size);
	397	pr_debug("maps in %s: %ld bytes\n", obj->path, (long)size);
	398	return 0;
	399	}
	400
29603665 WN	401	static int bpf_object__elf_collect(struct bpf_object *obj)
	402	{
	403	Elf *elf = obj->efile.elf;
	404	GElf_Ehdr *ep = &obj->efile.ehdr;
	405	Elf_Scn *scn = NULL;
	406	int idx = 0, err = 0;
	407
	408	/* Elf is corrupted/truncated, avoid calling elf_strptr. */
	409	if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) {
	410	pr_warning("failed to get e_shstrndx from %s\n",
	411	obj->path);
	412	return -EINVAL;
	413	}
	414
	415	while ((scn = elf_nextscn(elf, scn)) != NULL) {
	416	char *name;
	417	GElf_Shdr sh;
	418	Elf_Data *data;
	419
	420	idx++;
	421	if (gelf_getshdr(scn, &sh) != &sh) {
	422	pr_warning("failed to get section header from %s\n",
	423	obj->path);
	424	err = -EINVAL;
	425	goto out;
	426	}
	427
	428	name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
	429	if (!name) {
	430	pr_warning("failed to get section name from %s\n",
	431	obj->path);
	432	err = -EINVAL;
	433	goto out;
	434	}
	435
	436	data = elf_getdata(scn, 0);
	437	if (!data) {
	438	pr_warning("failed to get section data from %s(%s)\n",
	439	name, obj->path);
	440	err = -EINVAL;
	441	goto out;
	442	}
	443	pr_debug("section %s, size %ld, link %d, flags %lx, type=%d\n",
	444	name, (unsigned long)data->d_size,
	445	(int)sh.sh_link, (unsigned long)sh.sh_flags,
	446	(int)sh.sh_type);
cb1e5e96 WN	447
	448	if (strcmp(name, "license") == 0)
	449	err = bpf_object__init_license(obj,
	450	data->d_buf,
	451	data->d_size);
	452	else if (strcmp(name, "version") == 0)
	453	err = bpf_object__init_kversion(obj,
	454	data->d_buf,
	455	data->d_size);
0b3d1efa WN	456	else if (strcmp(name, "maps") == 0)
	457	err = bpf_object__init_maps(obj, data->d_buf,
	458	data->d_size);
bec7d68c WN	459	else if (sh.sh_type == SHT_SYMTAB) {
	460	if (obj->efile.symbols) {
	461	pr_warning("bpf: multiple SYMTAB in %s\n",
	462	obj->path);
	463	err = -EEXIST;
	464	} else
	465	obj->efile.symbols = data;
a5b8bd47 WN	466	} else if ((sh.sh_type == SHT_PROGBITS) &&
	467	(sh.sh_flags & SHF_EXECINSTR) &&
	468	(data->d_size > 0)) {
	469	err = bpf_object__add_program(obj, data->d_buf,
	470	data->d_size, name, idx);
	471	if (err) {
	472	char errmsg[128];
	473	strerror_r(-err, errmsg, sizeof(errmsg));
	474	pr_warning("failed to alloc program %s (%s): %s",
	475	name, obj->path, errmsg);
	476	}
b62f06e8 WN	477	} else if (sh.sh_type == SHT_REL) {
	478	void *reloc = obj->efile.reloc;
	479	int nr_reloc = obj->efile.nr_reloc + 1;
	480
	481	reloc = realloc(reloc,
	482	sizeof(obj->efile.reloc) nr_reloc);
	483	if (!reloc) {
	484	pr_warning("realloc failed\n");
	485	err = -ENOMEM;
	486	} else {
	487	int n = nr_reloc - 1;
	488
	489	obj->efile.reloc = reloc;
	490	obj->efile.nr_reloc = nr_reloc;
	491
	492	obj->efile.reloc[n].shdr = sh;
	493	obj->efile.reloc[n].data = data;
	494	}
bec7d68c	495	}
cb1e5e96 WN	496	if (err)
cb1e5e96 WN	497	goto out;
29603665 WN	498	}
	499	out:
	500	return err;
	501	}
	502
34090915 WN	503	static struct bpf_program *
	504	bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx)
	505	{
	506	struct bpf_program *prog;
	507	size_t i;
	508
	509	for (i = 0; i < obj->nr_programs; i++) {
	510	prog = &obj->programs[i];
	511	if (prog->idx == idx)
	512	return prog;
	513	}
	514	return NULL;
	515	}
	516
	517	static int
	518	bpf_program__collect_reloc(struct bpf_program *prog,
	519	size_t nr_maps, GElf_Shdr *shdr,
	520	Elf_Data data, Elf_Data symbols)
	521	{
	522	int i, nrels;
	523
	524	pr_debug("collecting relocating info for: '%s'\n",
	525	prog->section_name);
	526	nrels = shdr->sh_size / shdr->sh_entsize;
	527
	528	prog->reloc_desc = malloc(sizeof(prog->reloc_desc) nrels);
	529	if (!prog->reloc_desc) {
	530	pr_warning("failed to alloc memory in relocation\n");
	531	return -ENOMEM;
	532	}
	533	prog->nr_reloc = nrels;
	534
	535	for (i = 0; i < nrels; i++) {
	536	GElf_Sym sym;
	537	GElf_Rel rel;
	538	unsigned int insn_idx;
	539	struct bpf_insn *insns = prog->insns;
	540	size_t map_idx;
	541
	542	if (!gelf_getrel(data, i, &rel)) {
	543	pr_warning("relocation: failed to get %d reloc\n", i);
	544	return -EINVAL;
	545	}
	546
	547	insn_idx = rel.r_offset / sizeof(struct bpf_insn);
	548	pr_debug("relocation: insn_idx=%u\n", insn_idx);
	549
	550	if (!gelf_getsym(symbols,
	551	GELF_R_SYM(rel.r_info),
	552	&sym)) {
	553	pr_warning("relocation: symbol %"PRIx64" not found\n",
	554	GELF_R_SYM(rel.r_info));
	555	return -EINVAL;
	556	}
	557
	558	if (insns[insn_idx].code != (BPF_LD \| BPF_IMM \| BPF_DW)) {
	559	pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n",
	560	insn_idx, insns[insn_idx].code);
	561	return -EINVAL;
	562	}
	563
	564	map_idx = sym.st_value / sizeof(struct bpf_map_def);
	565	if (map_idx >= nr_maps) {
	566	pr_warning("bpf relocation: map_idx %d large than %d\n",
567	(int)map_idx, (int)nr_maps - 1);
568	return -EINVAL;
569	}
570
571	prog->reloc_desc[i].insn_idx = insn_idx;
572	prog->reloc_desc[i].map_idx = map_idx;
573	}
574	return 0;
575	}
576
52d3352e WN	577	static int
	578	bpf_object__create_maps(struct bpf_object *obj)
	579	{
	580	unsigned int i;
	581	size_t nr_maps;
	582	int *pfd;
	583
	584	nr_maps = obj->maps_buf_sz / sizeof(struct bpf_map_def);
	585	if (!obj->maps_buf \|\| !nr_maps) {
	586	pr_debug("don't need create maps for %s\n",
	587	obj->path);
	588	return 0;
	589	}
	590
	591	obj->map_fds = malloc(sizeof(int) * nr_maps);
	592	if (!obj->map_fds) {
	593	pr_warning("realloc perf_bpf_map_fds failed\n");
	594	return -ENOMEM;
	595	}
	596	obj->nr_map_fds = nr_maps;
	597
	598	/* fill all fd with -1 */
	599	memset(obj->map_fds, -1, sizeof(int) * nr_maps);
	600
	601	pfd = obj->map_fds;
	602	for (i = 0; i < nr_maps; i++) {
	603	struct bpf_map_def def;
	604
	605	def = (struct bpf_map_def )(obj->maps_buf +
	606	i * sizeof(struct bpf_map_def));
	607
	608	*pfd = bpf_create_map(def.type,
	609	def.key_size,
	610	def.value_size,
	611	def.max_entries);
	612	if (*pfd < 0) {
	613	size_t j;
	614	int err = *pfd;
	615
	616	pr_warning("failed to create map: %s\n",
	617	strerror(errno));
	618	for (j = 0; j < i; j++)
	619	zclose(obj->map_fds[j]);
	620	obj->nr_map_fds = 0;
	621	zfree(&obj->map_fds);
	622	return err;
	623	}
	624	pr_debug("create map: fd=%d\n", *pfd);
	625	pfd++;
	626	}
	627
	628	zfree(&obj->maps_buf);
	629	obj->maps_buf_sz = 0;
	630	return 0;
	631	}
	632
8a47a6c5 WN	633	static int
	634	bpf_program__relocate(struct bpf_program prog, int map_fds)
	635	{
	636	int i;
	637
	638	if (!prog \|\| !prog->reloc_desc)
	639	return 0;
	640
	641	for (i = 0; i < prog->nr_reloc; i++) {
	642	int insn_idx, map_idx;
	643	struct bpf_insn *insns = prog->insns;
	644
	645	insn_idx = prog->reloc_desc[i].insn_idx;
	646	map_idx = prog->reloc_desc[i].map_idx;
	647
	648	if (insn_idx >= (int)prog->insns_cnt) {
	649	pr_warning("relocation out of range: '%s'\n",
	650	prog->section_name);
	651	return -ERANGE;
	652	}
	653	insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
	654	insns[insn_idx].imm = map_fds[map_idx];
	655	}
	656
	657	zfree(&prog->reloc_desc);
	658	prog->nr_reloc = 0;
	659	return 0;
	660	}
	661
	662
	663	static int
	664	bpf_object__relocate(struct bpf_object *obj)
	665	{
	666	struct bpf_program *prog;
	667	size_t i;
	668	int err;
	669
	670	for (i = 0; i < obj->nr_programs; i++) {
	671	prog = &obj->programs[i];
	672
	673	err = bpf_program__relocate(prog, obj->map_fds);
	674	if (err) {
	675	pr_warning("failed to relocate '%s'\n",
	676	prog->section_name);
	677	return err;
	678	}
	679	}
	680	return 0;
	681	}
	682
34090915 WN	683	static int bpf_object__collect_reloc(struct bpf_object *obj)
	684	{
	685	int i, err;
	686
	687	if (!obj_elf_valid(obj)) {
	688	pr_warning("Internal error: elf object is closed\n");
	689	return -EINVAL;
	690	}
	691
	692	for (i = 0; i < obj->efile.nr_reloc; i++) {
	693	GElf_Shdr *shdr = &obj->efile.reloc[i].shdr;
	694	Elf_Data *data = obj->efile.reloc[i].data;
	695	int idx = shdr->sh_info;
	696	struct bpf_program *prog;
	697	size_t nr_maps = obj->maps_buf_sz /
	698	sizeof(struct bpf_map_def);
	699
	700	if (shdr->sh_type != SHT_REL) {
	701	pr_warning("internal error at %d\n", __LINE__);
	702	return -EINVAL;
	703	}
	704
	705	prog = bpf_object__find_prog_by_idx(obj, idx);
	706	if (!prog) {
	707	pr_warning("relocation failed: no %d section\n",
	708	idx);
	709	return -ENOENT;
	710	}
	711
	712	err = bpf_program__collect_reloc(prog, nr_maps,
	713	shdr, data,
	714	obj->efile.symbols);
	715	if (err)
	716	return -EINVAL;
	717	}
	718	return 0;
	719	}
	720
cb1e5e96 WN	721	static int bpf_object__validate(struct bpf_object *obj)
	722	{
	723	if (obj->kern_version == 0) {
	724	pr_warning("%s doesn't provide kernel version\n",
	725	obj->path);
	726	return -EINVAL;
	727	}
	728	return 0;
	729	}
	730
1a5e3fb1	731	static struct bpf_object *
6c956392	732	__bpf_object__open(const char path, void obj_buf, size_t obj_buf_sz)
1a5e3fb1 WN	733	{
	734	struct bpf_object *obj;
	735
	736	if (elf_version(EV_CURRENT) == EV_NONE) {
	737	pr_warning("failed to init libelf for %s\n", path);
	738	return NULL;
	739	}
	740
6c956392	741	obj = bpf_object__new(path, obj_buf, obj_buf_sz);
1a5e3fb1 WN	742	if (!obj)
	743	return NULL;
	744
	745	if (bpf_object__elf_init(obj))
	746	goto out;
cc4228d5 WN	747	if (bpf_object__check_endianness(obj))
cc4228d5 WN	748	goto out;
29603665 WN	749	if (bpf_object__elf_collect(obj))
29603665 WN	750	goto out;
34090915 WN	751	if (bpf_object__collect_reloc(obj))
34090915 WN	752	goto out;
cb1e5e96 WN	753	if (bpf_object__validate(obj))
cb1e5e96 WN	754	goto out;
1a5e3fb1 WN	755
	756	bpf_object__elf_finish(obj);
	757	return obj;
	758	out:
	759	bpf_object__close(obj);
	760	return NULL;
	761	}
	762
	763	struct bpf_object bpf_object__open(const char path)
	764	{
	765	/* param validation */
	766	if (!path)
	767	return NULL;
	768
	769	pr_debug("loading %s\n", path);
	770
6c956392 WN	771	return __bpf_object__open(path, NULL, 0);
	772	}
	773
	774	struct bpf_object bpf_object__open_buffer(void obj_buf,
	775	size_t obj_buf_sz)
	776	{
	777	/* param validation */
	778	if (!obj_buf \|\| obj_buf_sz <= 0)
	779	return NULL;
	780
	781	pr_debug("loading object from buffer\n");
	782
	783	return __bpf_object__open("[buffer]", obj_buf, obj_buf_sz);
1a5e3fb1 WN	784	}
1a5e3fb1 WN	785
52d3352e WN	786	int bpf_object__unload(struct bpf_object *obj)
	787	{
	788	size_t i;
	789
	790	if (!obj)
	791	return -EINVAL;
	792
	793	for (i = 0; i < obj->nr_map_fds; i++)
	794	zclose(obj->map_fds[i]);
	795	zfree(&obj->map_fds);
	796	obj->nr_map_fds = 0;
	797
	798	return 0;
	799	}
	800
	801	int bpf_object__load(struct bpf_object *obj)
	802	{
	803	if (!obj)
	804	return -EINVAL;
	805
	806	if (obj->loaded) {
	807	pr_warning("object should not be loaded twice\n");
	808	return -EINVAL;
	809	}
	810
	811	obj->loaded = true;
	812	if (bpf_object__create_maps(obj))
	813	goto out;
8a47a6c5 WN	814	if (bpf_object__relocate(obj))
8a47a6c5 WN	815	goto out;
52d3352e WN	816
	817	return 0;
	818	out:
	819	bpf_object__unload(obj);
	820	pr_warning("failed to load object '%s'\n", obj->path);
	821	return -EINVAL;
	822	}
	823
1a5e3fb1 WN	824	void bpf_object__close(struct bpf_object *obj)
1a5e3fb1 WN	825	{
a5b8bd47 WN	826	size_t i;
a5b8bd47 WN	827
1a5e3fb1 WN	828	if (!obj)
	829	return;
	830
	831	bpf_object__elf_finish(obj);
52d3352e	832	bpf_object__unload(obj);
1a5e3fb1	833
0b3d1efa	834	zfree(&obj->maps_buf);
a5b8bd47 WN	835
	836	if (obj->programs && obj->nr_programs) {
	837	for (i = 0; i < obj->nr_programs; i++)
	838	bpf_program__exit(&obj->programs[i]);
	839	}
	840	zfree(&obj->programs);
	841
1a5e3fb1 WN	842	free(obj);
1a5e3fb1 WN	843	}