blob: 251d9ea6252f958debb85a3fed7f3e923989e034 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* bpf-loader.c
*
* Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
* Copyright (C) 2015 Huawei Inc.
*/
#include <linux/bpf.h>
#include <bpf/libbpf.h>
#include <bpf/bpf.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <errno.h>
#include "perf.h"
#include "debug.h"
#include "evlist.h"
#include "bpf-loader.h"
#include "bpf-prologue.h"
#include "probe-event.h"
#include "probe-finder.h" // for MAX_PROBES
#include "parse-events.h"
#include "strfilter.h"
#include "llvm-utils.h"
#include "c++/clang-c.h"
static int libbpf_perf_print(enum libbpf_print_level level __attribute__((unused)),
const char *fmt, va_list args)
{
return veprintf(1, verbose, pr_fmt(fmt), args);
}
struct bpf_prog_priv {
bool is_tp;
char *sys_name;
char *evt_name;
struct perf_probe_event pev;
bool need_prologue;
struct bpf_insn *insns_buf;
int nr_types;
int *type_mapping;
};
static bool libbpf_initialized;
struct bpf_object *
bpf__prepare_load_buffer(void *obj_buf, size_t obj_buf_sz, const char *name)
{
struct bpf_object *obj;
if (!libbpf_initialized) {
libbpf_set_print(libbpf_perf_print);
libbpf_initialized = true;
}
obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, name);
if (IS_ERR_OR_NULL(obj)) {
pr_debug("bpf: failed to load buffer\n");
return ERR_PTR(-EINVAL);
}
return obj;
}
struct bpf_object *bpf__prepare_load(const char *filename, bool source)
{
struct bpf_object *obj;
if (!libbpf_initialized) {
libbpf_set_print(libbpf_perf_print);
libbpf_initialized = true;
}
if (source) {
int err;
void *obj_buf;
size_t obj_buf_sz;
perf_clang__init();
err = perf_clang__compile_bpf(filename, &obj_buf, &obj_buf_sz);
perf_clang__cleanup();
if (err) {
pr_debug("bpf: builtin compilation failed: %d, try external compiler\n", err);
err = llvm__compile_bpf(filename, &obj_buf, &obj_buf_sz);
if (err)
return ERR_PTR(-BPF_LOADER_ERRNO__COMPILE);
} else
pr_debug("bpf: successful builtin compilation\n");
obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, filename);
if (!IS_ERR_OR_NULL(obj) && llvm_param.dump_obj)
llvm__dump_obj(filename, obj_buf, obj_buf_sz);
free(obj_buf);
} else
obj = bpf_object__open(filename);
if (IS_ERR_OR_NULL(obj)) {
pr_debug("bpf: failed to load %s\n", filename);
return obj;
}
return obj;
}
void bpf__clear(void)
{
struct bpf_object *obj, *tmp;
bpf_object__for_each_safe(obj, tmp) {
bpf__unprobe(obj);
bpf_object__close(obj);
}
}
static void
clear_prog_priv(struct bpf_program *prog __maybe_unused,
void *_priv)
{
struct bpf_prog_priv *priv = _priv;
cleanup_perf_probe_events(&priv->pev, 1);
zfree(&priv->insns_buf);
zfree(&priv->type_mapping);
zfree(&priv->sys_name);
zfree(&priv->evt_name);
free(priv);
}
static int
prog_config__exec(const char *value, struct perf_probe_event *pev)
{
pev->uprobes = true;
pev->target = strdup(value);
if (!pev->target)
return -ENOMEM;
return 0;
}
static int
prog_config__module(const char *value, struct perf_probe_event *pev)
{
pev->uprobes = false;
pev->target = strdup(value);
if (!pev->target)
return -ENOMEM;
return 0;
}
static int
prog_config__bool(const char *value, bool *pbool, bool invert)
{
int err;
bool bool_value;
if (!pbool)
return -EINVAL;
err = strtobool(value, &bool_value);
if (err)
return err;
*pbool = invert ? !bool_value : bool_value;
return 0;
}
static int
prog_config__inlines(const char *value,
struct perf_probe_event *pev __maybe_unused)
{
return prog_config__bool(value, &probe_conf.no_inlines, true);
}
static int
prog_config__force(const char *value,
struct perf_probe_event *pev __maybe_unused)
{
return prog_config__bool(value, &probe_conf.force_add, false);
}
static struct {
const char *key;
const char *usage;
const char *desc;
int (*func)(const char *, struct perf_probe_event *);
} bpf_prog_config_terms[] = {
{
.key = "exec",
.usage = "exec=<full path of file>",
.desc = "Set uprobe target",
.func = prog_config__exec,
},
{
.key = "module",
.usage = "module=<module name> ",
.desc = "Set kprobe module",
.func = prog_config__module,
},
{
.key = "inlines",
.usage = "inlines=[yes|no] ",
.desc = "Probe at inline symbol",
.func = prog_config__inlines,
},
{
.key = "force",
.usage = "force=[yes|no] ",
.desc = "Forcibly add events with existing name",
.func = prog_config__force,
},
};
static int
do_prog_config(const char *key, const char *value,
struct perf_probe_event *pev)
{
unsigned int i;
pr_debug("config bpf program: %s=%s\n", key, value);
for (i = 0; i < ARRAY_SIZE(bpf_prog_config_terms); i++)
if (strcmp(key, bpf_prog_config_terms[i].key) == 0)
return bpf_prog_config_terms[i].func(value, pev);
pr_debug("BPF: ERROR: invalid program config option: %s=%s\n",
key, value);
pr_debug("\nHint: Valid options are:\n");
for (i = 0; i < ARRAY_SIZE(bpf_prog_config_terms); i++)
pr_debug("\t%s:\t%s\n", bpf_prog_config_terms[i].usage,
bpf_prog_config_terms[i].desc);
pr_debug("\n");
return -BPF_LOADER_ERRNO__PROGCONF_TERM;
}
static const char *
parse_prog_config_kvpair(const char *config_str, struct perf_probe_event *pev)
{
char *text = strdup(config_str);
char *sep, *line;
const char *main_str = NULL;
int err = 0;
if (!text) {
pr_debug("Not enough memory: dup config_str failed\n");
return ERR_PTR(-ENOMEM);
}
line = text;
while ((sep = strchr(line, ';'))) {
char *equ;
*sep = '\0';
equ = strchr(line, '=');
if (!equ) {
pr_warning("WARNING: invalid config in BPF object: %s\n",
line);
pr_warning("\tShould be 'key=value'.\n");
goto nextline;
}
*equ = '\0';
err = do_prog_config(line, equ + 1, pev);
if (err)
break;
nextline:
line = sep + 1;
}
if (!err)
main_str = config_str + (line - text);
free(text);
return err ? ERR_PTR(err) : main_str;
}
static int
parse_prog_config(const char *config_str, const char **p_main_str,
bool *is_tp, struct perf_probe_event *pev)
{
int err;
const char *main_str = parse_prog_config_kvpair(config_str, pev);
if (IS_ERR(main_str))
return PTR_ERR(main_str);
*p_main_str = main_str;
if (!strchr(main_str, '=')) {
/* Is a tracepoint event? */
const char *s = strchr(main_str, ':');
if (!s) {
pr_debug("bpf: '%s' is not a valid tracepoint\n",
config_str);
return -BPF_LOADER_ERRNO__CONFIG;
}
*is_tp = true;
return 0;
}
*is_tp = false;
err = parse_perf_probe_command(main_str, pev);
if (err < 0) {
pr_debug("bpf: '%s' is not a valid config string\n",
config_str);
/* parse failed, don't need clear pev. */
return -BPF_LOADER_ERRNO__CONFIG;
}
return 0;
}
static int
config_bpf_program(struct bpf_program *prog)
{
struct perf_probe_event *pev = NULL;
struct bpf_prog_priv *priv = NULL;
const char *config_str, *main_str;
bool is_tp = false;
int err;
/* Initialize per-program probing setting */
probe_conf.no_inlines = false;
probe_conf.force_add = false;
config_str = bpf_program__title(prog, false);
if (IS_ERR(config_str)) {
pr_debug("bpf: unable to get title for program\n");
return PTR_ERR(config_str);
}
priv = calloc(sizeof(*priv), 1);
if (!priv) {
pr_debug("bpf: failed to alloc priv\n");
return -ENOMEM;
}
pev = &priv->pev;
pr_debug("bpf: config program '%s'\n", config_str);
err = parse_prog_config(config_str, &main_str, &is_tp, pev);
if (err)
goto errout;
if (is_tp) {
char *s = strchr(main_str, ':');
priv->is_tp = true;
priv->sys_name = strndup(main_str, s - main_str);
priv->evt_name = strdup(s + 1);
goto set_priv;
}
if (pev->group && strcmp(pev->group, PERF_BPF_PROBE_GROUP)) {
pr_debug("bpf: '%s': group for event is set and not '%s'.\n",
config_str, PERF_BPF_PROBE_GROUP);
err = -BPF_LOADER_ERRNO__GROUP;
goto errout;
} else if (!pev->group)
pev->group = strdup(PERF_BPF_PROBE_GROUP);
if (!pev->group) {
pr_debug("bpf: strdup failed\n");
err = -ENOMEM;
goto errout;
}
if (!pev->event) {
pr_debug("bpf: '%s': event name is missing. Section name should be 'key=value'\n",
config_str);
err = -BPF_LOADER_ERRNO__EVENTNAME;
goto errout;
}
pr_debug("bpf: config '%s' is ok\n", config_str);
set_priv:
err = bpf_program__set_priv(prog, priv, clear_prog_priv);
if (err) {
pr_debug("Failed to set priv for program '%s'\n", config_str);
goto errout;
}
return 0;
errout:
if (pev)
clear_perf_probe_event(pev);
free(priv);
return err;
}
static int bpf__prepare_probe(void)
{
static int err = 0;
static bool initialized = false;
/*
* Make err static, so if init failed the first, bpf__prepare_probe()
* fails each time without calling init_probe_symbol_maps multiple
* times.
*/
if (initialized)
return err;
initialized = true;
err = init_probe_symbol_maps(false);
if (err < 0)
pr_debug("Failed to init_probe_symbol_maps\n");
probe_conf.max_probes = MAX_PROBES;
return err;
}
static int
preproc_gen_prologue(struct bpf_program *prog, int n,
struct bpf_insn *orig_insns, int orig_insns_cnt,
struct bpf_prog_prep_result *res)
{
struct bpf_prog_priv *priv = bpf_program__priv(prog);
struct probe_trace_event *tev;
struct perf_probe_event *pev;
struct bpf_insn *buf;
size_t prologue_cnt = 0;
int i, err;
if (IS_ERR(priv) || !priv || priv->is_tp)
goto errout;
pev = &priv->pev;
if (n < 0 || n >= priv->nr_types)
goto errout;
/* Find a tev belongs to that type */
for (i = 0; i < pev->ntevs; i++) {
if (priv->type_mapping[i] == n)
break;
}
if (i >= pev->ntevs) {
pr_debug("Internal error: prologue type %d not found\n", n);
return -BPF_LOADER_ERRNO__PROLOGUE;
}
tev = &pev->tevs[i];
buf = priv->insns_buf;
err = bpf__gen_prologue(tev->args, tev->nargs,
buf, &prologue_cnt,
BPF_MAXINSNS - orig_insns_cnt);
if (err) {
const char *title;
title = bpf_program__title(prog, false);
if (!title)
title = "[unknown]";
pr_debug("Failed to generate prologue for program %s\n",
title);
return err;
}
memcpy(&buf[prologue_cnt], orig_insns,
sizeof(struct bpf_insn) * orig_insns_cnt);
res->new_insn_ptr = buf;
res->new_insn_cnt = prologue_cnt + orig_insns_cnt;
res->pfd = NULL;
return 0;
errout:
pr_debug("Internal error in preproc_gen_prologue\n");
return -BPF_LOADER_ERRNO__PROLOGUE;
}
/*
* compare_tev_args is reflexive, transitive and antisymmetric.
* I can proof it but this margin is too narrow to contain.
*/
static int compare_tev_args(const void *ptev1, const void *ptev2)
{
int i, ret;
const struct probe_trace_event *tev1 =
*(const struct probe_trace_event **)ptev1;
const struct probe_trace_event *tev2 =
*(const struct probe_trace_event **)ptev2;
ret = tev2->nargs - tev1->nargs;
if (ret)
return ret;
for (i = 0; i < tev1->nargs; i++) {
struct probe_trace_arg *arg1, *arg2;
struct probe_trace_arg_ref *ref1, *ref2;
arg1 = &tev1->args[i];
arg2 = &tev2->args[i];
ret = strcmp(arg1->value, arg2->value);
if (ret)
return ret;
ref1 = arg1->ref;
ref2 = arg2->ref;
while (ref1 && ref2) {
ret = ref2->offset - ref1->offset;
if (ret)
return ret;
ref1 = ref1->next;
ref2 = ref2->next;
}
if (ref1 || ref2)
return ref2 ? 1 : -1;
}
return 0;
}
/*
* Assign a type number to each tevs in a pev.
* mapping is an array with same slots as tevs in that pev.
* nr_types will be set to number of types.
*/
static int map_prologue(struct perf_probe_event *pev, int *mapping,
int *nr_types)
{
int i, type = 0;
struct probe_trace_event **ptevs;
size_t array_sz = sizeof(*ptevs) * pev->ntevs;
ptevs = malloc(array_sz);
if (!ptevs) {
pr_debug("Not enough memory: alloc ptevs failed\n");
return -ENOMEM;
}
pr_debug("In map_prologue, ntevs=%d\n", pev->ntevs);
for (i = 0; i < pev->ntevs; i++)
ptevs[i] = &pev->tevs[i];
qsort(ptevs, pev->ntevs, sizeof(*ptevs),
compare_tev_args);
for (i = 0; i < pev->ntevs; i++) {
int n;
n = ptevs[i] - pev->tevs;
if (i == 0) {
mapping[n] = type;
pr_debug("mapping[%d]=%d\n", n, type);
continue;
}
if (compare_tev_args(ptevs + i, ptevs + i - 1) == 0)
mapping[n] = type;
else
mapping[n] = ++type;
pr_debug("mapping[%d]=%d\n", n, mapping[n]);
}
free(ptevs);
*nr_types = type + 1;
return 0;
}
static int hook_load_preprocessor(struct bpf_program *prog)
{
struct bpf_prog_priv *priv = bpf_program__priv(prog);
struct perf_probe_event *pev;
bool need_prologue = false;
int err, i;
if (IS_ERR(priv) || !priv) {
pr_debug("Internal error when hook preprocessor\n");
return -BPF_LOADER_ERRNO__INTERNAL;
}
if (priv->is_tp) {
priv->need_prologue = false;
return 0;
}
pev = &priv->pev;
for (i = 0; i < pev->ntevs; i++) {
struct probe_trace_event *tev = &pev->tevs[i];
if (tev->nargs > 0) {
need_prologue = true;
break;
}
}
/*
* Since all tevs don't have argument, we don't need generate
* prologue.
*/
if (!need_prologue) {
priv->need_prologue = false;
return 0;
}
priv->need_prologue = true;
priv->insns_buf = malloc(sizeof(struct bpf_insn) * BPF_MAXINSNS);
if (!priv->insns_buf) {
pr_debug("Not enough memory: alloc insns_buf failed\n");
return -ENOMEM;
}
priv->type_mapping = malloc(sizeof(int) * pev->ntevs);
if (!priv->type_mapping) {
pr_debug("Not enough memory: alloc type_mapping failed\n");
return -ENOMEM;
}
memset(priv->type_mapping, -1,
sizeof(int) * pev->ntevs);
err = map_prologue(pev, priv->type_mapping, &priv->nr_types);
if (err)
return err;
err = bpf_program__set_prep(prog, priv->nr_types,
preproc_gen_prologue);
return err;
}
int bpf__probe(struct bpf_object *obj)
{
int err = 0;
struct bpf_program *prog;
struct bpf_prog_priv *priv;
struct perf_probe_event *pev;
err = bpf__prepare_probe();
if (err) {
pr_debug("bpf__prepare_probe failed\n");
return err;
}
bpf_object__for_each_program(prog, obj) {
err = config_bpf_program(prog);
if (err)
goto out;
priv = bpf_program__priv(prog);
if (IS_ERR(priv) || !priv) {
err = PTR_ERR(priv);
goto out;
}
if (priv->is_tp) {
bpf_program__set_tracepoint(prog);
continue;
}
bpf_program__set_kprobe(prog);
pev = &priv->pev;
err = convert_perf_probe_events(pev, 1);
if (err < 0) {
pr_debug("bpf_probe: failed to convert perf probe events\n");
goto out;
}
err = apply_perf_probe_events(pev, 1);
if (err < 0) {
pr_debug("bpf_probe: failed to apply perf probe events\n");
goto out;
}
/*
* After probing, let's consider prologue, which
* adds program fetcher to BPF programs.
*
* hook_load_preprocessorr() hooks pre-processor
* to bpf_program, let it generate prologue
* dynamically during loading.
*/
err = hook_load_preprocessor(prog);
if (err)
goto out;
}
out:
return err < 0 ? err : 0;
}
#define EVENTS_WRITE_BUFSIZE 4096
int bpf__unprobe(struct bpf_object *obj)
{
int err, ret = 0;
struct bpf_program *prog;
bpf_object__for_each_program(prog, obj) {
struct bpf_prog_priv *priv = bpf_program__priv(prog);
int i;
if (IS_ERR(priv) || !priv || priv->is_tp)
continue;
for (i = 0; i < priv->pev.ntevs; i++) {
struct probe_trace_event *tev = &priv->pev.tevs[i];
char name_buf[EVENTS_WRITE_BUFSIZE];
struct strfilter *delfilter;
snprintf(name_buf, EVENTS_WRITE_BUFSIZE,
"%s:%s", tev->group, tev->event);
name_buf[EVENTS_WRITE_BUFSIZE - 1] = '\0';
delfilter = strfilter__new(name_buf, NULL);
if (!delfilter) {
pr_debug("Failed to create filter for unprobing\n");
ret = -ENOMEM;
continue;
}
err = del_perf_probe_events(delfilter);
strfilter__delete(delfilter);
if (err) {
pr_debug("Failed to delete %s\n", name_buf);
ret = err;
continue;
}
}
}
return ret;
}
int bpf__load(struct bpf_object *obj)
{
int err;
err = bpf_object__load(obj);
if (err) {
char bf[128];
libbpf_strerror(err, bf, sizeof(bf));
pr_debug("bpf: load objects failed: err=%d: (%s)\n", err, bf);
return err;
}
return 0;
}
int bpf__foreach_event(struct bpf_object *obj,
bpf_prog_iter_callback_t func,
void *arg)
{
struct bpf_program *prog;
int err;
bpf_object__for_each_program(prog, obj) {
struct bpf_prog_priv *priv = bpf_program__priv(prog);
struct probe_trace_event *tev;
struct perf_probe_event *pev;
int i, fd;
if (IS_ERR(priv) || !priv) {
pr_debug("bpf: failed to get private field\n");
return -BPF_LOADER_ERRNO__INTERNAL;
}
if (priv->is_tp) {
fd = bpf_program__fd(prog);
err = (*func)(priv->sys_name, priv->evt_name, fd, arg);
if (err) {
pr_debug("bpf: tracepoint call back failed, stop iterate\n");
return err;
}
continue;
}
pev = &priv->pev;
for (i = 0; i < pev->ntevs; i++) {
tev = &pev->tevs[i];
if (priv->need_prologue) {
int type = priv->type_mapping[i];
fd = bpf_program__nth_fd(prog, type);
} else {
fd = bpf_program__fd(prog);
}
if (fd < 0) {
pr_debug("bpf: failed to get file descriptor\n");
return fd;
}
err = (*func)(tev->group, tev->event, fd, arg);
if (err) {
pr_debug("bpf: call back failed, stop iterate\n");
return err;
}
}
}
return 0;
}
enum bpf_map_op_type {
BPF_MAP_OP_SET_VALUE,
BPF_MAP_OP_SET_EVSEL,
};
enum bpf_map_key_type {
BPF_MAP_KEY_ALL,
BPF_MAP_KEY_RANGES,
};
struct bpf_map_op {
struct list_head list;
enum bpf_map_op_type op_type;
enum bpf_map_key_type key_type;
union {
struct parse_events_array array;
} k;
union {
u64 value;
struct perf_evsel *evsel;
} v;
};
struct bpf_map_priv {
struct list_head ops_list;
};
static void
bpf_map_op__delete(struct bpf_map_op *op)
{
if (!list_empty(&op->list))
list_del(&op->list);
if (op->key_type == BPF_MAP_KEY_RANGES)
parse_events__clear_array(&op->k.array);
free(op);
}
static void
bpf_map_priv__purge(struct bpf_map_priv *priv)
{
struct bpf_map_op *pos, *n;
list_for_each_entry_safe(pos, n, &priv->ops_list, list) {
list_del_init(&pos->list);
bpf_map_op__delete(pos);
}
}
static void
bpf_map_priv__clear(struct bpf_map *map __maybe_unused,
void *_priv)
{
struct bpf_map_priv *priv = _priv;
bpf_map_priv__purge(priv);
free(priv);
}
static int
bpf_map_op_setkey(struct bpf_map_op *op, struct parse_events_term *term)
{
op->key_type = BPF_MAP_KEY_ALL;
if (!term)
return 0;
if (term->array.nr_ranges) {
size_t memsz = term->array.nr_ranges *
sizeof(op->k.array.ranges[0]);
op->k.array.ranges = memdup(term->array.ranges, memsz);
if (!op->k.array.ranges) {
pr_debug("Not enough memory to alloc indices for map\n");
return -ENOMEM;
}
op->key_type = BPF_MAP_KEY_RANGES;
op->k.array.nr_ranges = term->array.nr_ranges;
}
return 0;
}
static struct bpf_map_op *
bpf_map_op__new(struct parse_events_term *term)
{
struct bpf_map_op *op;
int err;
op = zalloc(sizeof(*op));
if (!op) {
pr_debug("Failed to alloc bpf_map_op\n");
return ERR_PTR(-ENOMEM);
}
INIT_LIST_HEAD(&op->list);
err = bpf_map_op_setkey(op, term);
if (err) {
free(op);
return ERR_PTR(err);
}
return op;
}
static struct bpf_map_op *
bpf_map_op__clone(struct bpf_map_op *op)
{
struct bpf_map_op *newop;
newop = memdup(op, sizeof(*op));
if (!newop) {
pr_debug("Failed to alloc bpf_map_op\n");
return NULL;
}
INIT_LIST_HEAD(&newop->list);
if (op->key_type == BPF_MAP_KEY_RANGES) {
size_t memsz = op->k.array.nr_ranges *
sizeof(op->k.array.ranges[0]);
newop->k.array.ranges = memdup(op->k.array.ranges, memsz);
if (!newop->k.array.ranges) {
pr_debug("Failed to alloc indices for map\n");
free(newop);
return NULL;
}
}
return newop;
}
static struct bpf_map_priv *
bpf_map_priv__clone(struct bpf_map_priv *priv)
{
struct bpf_map_priv *newpriv;
struct bpf_map_op *pos, *newop;
newpriv = zalloc(sizeof(*newpriv));
if (!newpriv) {
pr_debug("Not enough memory to alloc map private\n");
return NULL;
}
INIT_LIST_HEAD(&newpriv->ops_list);
list_for_each_entry(pos, &priv->ops_list, list) {
newop = bpf_map_op__clone(pos);
if (!newop) {
bpf_map_priv__purge(newpriv);
return NULL;
}
list_add_tail(&newop->list, &newpriv->ops_list);
}
return newpriv;
}
static int
bpf_map__add_op(struct bpf_map *map, struct bpf_map_op *op)
{
const char *map_name = bpf_map__name(map);
struct bpf_map_priv *priv = bpf_map__priv(map);
if (IS_ERR(priv)) {
pr_debug("Failed to get private from map %s\n", map_name);
return PTR_ERR(priv);
}
if (!priv) {
priv = zalloc(sizeof(*priv));
if (!priv) {
pr_debug("Not enough memory to alloc map private\n");
return -ENOMEM;
}
INIT_LIST_HEAD(&priv->ops_list);
if (bpf_map__set_priv(map, priv, bpf_map_priv__clear)) {
free(priv);
return -BPF_LOADER_ERRNO__INTERNAL;
}
}
list_add_tail(&op->list, &priv->ops_list);
return 0;
}
static struct bpf_map_op *
bpf_map__add_newop(struct bpf_map *map, struct parse_events_term *term)
{
struct bpf_map_op *op;
int err;
op = bpf_map_op__new(term);
if (IS_ERR(op))
return op;
err = bpf_map__add_op(map, op);
if (err) {
bpf_map_op__delete(op);
return ERR_PTR(err);
}
return op;
}
static int
__bpf_map__config_value(struct bpf_map *map,
struct parse_events_term *term)
{
struct bpf_map_op *op;
const char *map_name = bpf_map__name(map);
const struct bpf_map_def *def = bpf_map__def(map);
if (IS_ERR(def)) {
pr_debug("Unable to get map definition from '%s'\n",
map_name);
return -BPF_LOADER_ERRNO__INTERNAL;
}
if (def->type != BPF_MAP_TYPE_ARRAY) {
pr_debug("Map %s type is not BPF_MAP_TYPE_ARRAY\n",
map_name);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_TYPE;
}
if (def->key_size < sizeof(unsigned int)) {
pr_debug("Map %s has incorrect key size\n", map_name);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_KEYSIZE;
}
switch (def->value_size) {
case 1:
case 2:
case 4:
case 8:
break;
default:
pr_debug("Map %s has incorrect value size\n", map_name);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_VALUESIZE;
}
op = bpf_map__add_newop(map, term);
if (IS_ERR(op))
return PTR_ERR(op);
op->op_type = BPF_MAP_OP_SET_VALUE;
op->v.value = term->val.num;
return 0;
}
static int
bpf_map__config_value(struct bpf_map *map,
struct parse_events_term *term,
struct perf_evlist *evlist __maybe_unused)
{
if (!term->err_val) {
pr_debug("Config value not set\n");
return -BPF_LOADER_ERRNO__OBJCONF_CONF;
}
if (term->type_val != PARSE_EVENTS__TERM_TYPE_NUM) {
pr_debug("ERROR: wrong value type for 'value'\n");
return -BPF_LOADER_ERRNO__OBJCONF_MAP_VALUE;
}
return __bpf_map__config_value(map, term);
}
static int
__bpf_map__config_event(struct bpf_map *map,
struct parse_events_term *term,
struct perf_evlist *evlist)
{
struct perf_evsel *evsel;
const struct bpf_map_def *def;
struct bpf_map_op *op;
const char *map_name = bpf_map__name(map);
evsel = perf_evlist__find_evsel_by_str(evlist, term->val.str);
if (!evsel) {
pr_debug("Event (for '%s') '%s' doesn't exist\n",
map_name, term->val.str);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_NOEVT;
}
def = bpf_map__def(map);
if (IS_ERR(def)) {
pr_debug("Unable to get map definition from '%s'\n",
map_name);
return PTR_ERR(def);
}
/*
* No need to check key_size and value_size:
* kernel has already checked them.
*/
if (def->type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
pr_debug("Map %s type is not BPF_MAP_TYPE_PERF_EVENT_ARRAY\n",
map_name);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_TYPE;
}
op = bpf_map__add_newop(map, term);
if (IS_ERR(op))
return PTR_ERR(op);
op->op_type = BPF_MAP_OP_SET_EVSEL;
op->v.evsel = evsel;
return 0;
}
static int
bpf_map__config_event(struct bpf_map *map,
struct parse_events_term *term,
struct perf_evlist *evlist)
{
if (!term->err_val) {
pr_debug("Config value not set\n");
return -BPF_LOADER_ERRNO__OBJCONF_CONF;
}
if (term->type_val != PARSE_EVENTS__TERM_TYPE_STR) {
pr_debug("ERROR: wrong value type for 'event'\n");
return -BPF_LOADER_ERRNO__OBJCONF_MAP_VALUE;
}
return __bpf_map__config_event(map, term, evlist);
}
struct bpf_obj_config__map_func {
const char *config_opt;
int (*config_func)(struct bpf_map *, struct parse_events_term *,
struct perf_evlist *);
};
struct bpf_obj_config__map_func bpf_obj_config__map_funcs[] = {
{"value", bpf_map__config_value},
{"event", bpf_map__config_event},
};
static int
config_map_indices_range_check(struct parse_events_term *term,
struct bpf_map *map,
const char *map_name)
{
struct parse_events_array *array = &term->array;
const struct bpf_map_def *def;
unsigned int i;
if (!array->nr_ranges)
return 0;
if (!array->ranges) {
pr_debug("ERROR: map %s: array->nr_ranges is %d but range array is NULL\n",
map_name, (int)array->nr_ranges);
return -BPF_LOADER_ERRNO__INTERNAL;
}
def = bpf_map__def(map);
if (IS_ERR(def)) {
pr_debug("ERROR: Unable to get map definition from '%s'\n",
map_name);
return -BPF_LOADER_ERRNO__INTERNAL;
}
for (i = 0; i < array->nr_ranges; i++) {
unsigned int start = array->ranges[i].start;
size_t length = array->ranges[i].length;
unsigned int idx = start + length - 1;
if (idx >= def->max_entries) {
pr_debug("ERROR: index %d too large\n", idx);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_IDX2BIG;
}
}
return 0;
}
static int
bpf__obj_config_map(struct bpf_object *obj,
struct parse_events_term *term,
struct perf_evlist *evlist,
int *key_scan_pos)
{
/* key is "map:<mapname>.<config opt>" */
char *map_name = strdup(term->config + sizeof("map:") - 1);
struct bpf_map *map;
int err = -BPF_LOADER_ERRNO__OBJCONF_OPT;
char *map_opt;
size_t i;
if (!map_name)
return -ENOMEM;
map_opt = strchr(map_name, '.');
if (!map_opt) {
pr_debug("ERROR: Invalid map config: %s\n", map_name);
goto out;
}
*map_opt++ = '\0';
if (*map_opt == '\0') {
pr_debug("ERROR: Invalid map option: %s\n", term->config);
goto out;
}
map = bpf_object__find_map_by_name(obj, map_name);
if (!map) {
pr_debug("ERROR: Map %s doesn't exist\n", map_name);
err = -BPF_LOADER_ERRNO__OBJCONF_MAP_NOTEXIST;
goto out;
}
*key_scan_pos += strlen(map_opt);
err = config_map_indices_range_check(term, map, map_name);
if (err)
goto out;
*key_scan_pos -= strlen(map_opt);
for (i = 0; i < ARRAY_SIZE(bpf_obj_config__map_funcs); i++) {
struct bpf_obj_config__map_func *func =
&bpf_obj_config__map_funcs[i];
if (strcmp(map_opt, func->config_opt) == 0) {
err = func->config_func(map, term, evlist);
goto out;
}
}
pr_debug("ERROR: Invalid map config option '%s'\n", map_opt);
err = -BPF_LOADER_ERRNO__OBJCONF_MAP_OPT;
out:
free(map_name);
if (!err)
key_scan_pos += strlen(map_opt);
return err;
}
int bpf__config_obj(struct bpf_object *obj,
struct parse_events_term *term,
struct perf_evlist *evlist,
int *error_pos)
{
int key_scan_pos = 0;
int err;
if (!obj || !term || !term->config)
return -EINVAL;
if (strstarts(term->config, "map:")) {
key_scan_pos = sizeof("map:") - 1;
err = bpf__obj_config_map(obj, term, evlist, &key_scan_pos);
goto out;
}
err = -BPF_LOADER_ERRNO__OBJCONF_OPT;
out:
if (error_pos)
*error_pos = key_scan_pos;
return err;
}
typedef int (*map_config_func_t)(const char *name, int map_fd,
const struct bpf_map_def *pdef,
struct bpf_map_op *op,
void *pkey, void *arg);
static int
foreach_key_array_all(map_config_func_t func,
void *arg, const char *name,
int map_fd, const struct bpf_map_def *pdef,
struct bpf_map_op *op)
{
unsigned int i;
int err;
for (i = 0; i < pdef->max_entries; i++) {
err = func(name, map_fd, pdef, op, &i, arg);
if (err) {
pr_debug("ERROR: failed to insert value to %s[%u]\n",
name, i);
return err;
}
}
return 0;
}
static int
foreach_key_array_ranges(map_config_func_t func, void *arg,
const char *name, int map_fd,
const struct bpf_map_def *pdef,
struct bpf_map_op *op)
{
unsigned int i, j;
int err;
for (i = 0; i < op->k.array.nr_ranges; i++) {
unsigned int start = op->k.array.ranges[i].start;
size_t length = op->k.array.ranges[i].length;
for (j = 0; j < length; j++) {
unsigned int idx = start + j;
err = func(name, map_fd, pdef, op, &idx, arg);
if (err) {
pr_debug("ERROR: failed to insert value to %s[%u]\n",
name, idx);
return err;
}
}
}
return 0;
}
static int
bpf_map_config_foreach_key(struct bpf_map *map,
map_config_func_t func,
void *arg)
{
int err, map_fd;
struct bpf_map_op *op;
const struct bpf_map_def *def;
const char *name = bpf_map__name(map);
struct bpf_map_priv *priv = bpf_map__priv(map);
if (IS_ERR(priv)) {
pr_debug("ERROR: failed to get private from map %s\n", name);
return -BPF_LOADER_ERRNO__INTERNAL;
}
if (!priv || list_empty(&priv->ops_list)) {
pr_debug("INFO: nothing to config for map %s\n", name);
return 0;
}
def = bpf_map__def(map);
if (IS_ERR(def)) {
pr_debug("ERROR: failed to get definition from map %s\n", name);
return -BPF_LOADER_ERRNO__INTERNAL;
}
map_fd = bpf_map__fd(map);
if (map_fd < 0) {
pr_debug("ERROR: failed to get fd from map %s\n", name);
return map_fd;
}
list_for_each_entry(op, &priv->ops_list, list) {
switch (def->type) {
case BPF_MAP_TYPE_ARRAY:
case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
switch (op->key_type) {
case BPF_MAP_KEY_ALL:
err = foreach_key_array_all(func, arg, name,
map_fd, def, op);
break;
case BPF_MAP_KEY_RANGES:
err = foreach_key_array_ranges(func, arg, name,
map_fd, def,
op);
break;
default:
pr_debug("ERROR: keytype for map '%s' invalid\n",
name);
return -BPF_LOADER_ERRNO__INTERNAL;
}
if (err)
return err;
break;
default:
pr_debug("ERROR: type of '%s' incorrect\n", name);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_TYPE;
}
}
return 0;
}
static int
apply_config_value_for_key(int map_fd, void *pkey,
size_t val_size, u64 val)
{
int err = 0;
switch (val_size) {
case 1: {
u8 _val = (u8)(val);
err = bpf_map_update_elem(map_fd, pkey, &_val, BPF_ANY);
break;
}
case 2: {
u16 _val = (u16)(val);
err = bpf_map_update_elem(map_fd, pkey, &_val, BPF_ANY);
break;
}
case 4: {
u32 _val = (u32)(val);
err = bpf_map_update_elem(map_fd, pkey, &_val, BPF_ANY);
break;
}
case 8: {
err = bpf_map_update_elem(map_fd, pkey, &val, BPF_ANY);
break;
}
default:
pr_debug("ERROR: invalid value size\n");
return -BPF_LOADER_ERRNO__OBJCONF_MAP_VALUESIZE;
}
if (err && errno)
err = -errno;
return err;
}
static int
apply_config_evsel_for_key(const char *name, int map_fd, void *pkey,
struct perf_evsel *evsel)
{
struct xyarray *xy = evsel->fd;
struct perf_event_attr *attr;
unsigned int key, events;
bool check_pass = false;
int *evt_fd;
int err;
if (!xy) {
pr_debug("ERROR: evsel not ready for map %s\n", name);
return -BPF_LOADER_ERRNO__INTERNAL;
}
if (xy->row_size / xy->entry_size != 1) {
pr_debug("ERROR: Dimension of target event is incorrect for map %s\n",
name);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_EVTDIM;
}
attr = &evsel->attr;
if (attr->inherit) {
pr_debug("ERROR: Can't put inherit event into map %s\n", name);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_EVTINH;
}
if (perf_evsel__is_bpf_output(evsel))
check_pass = true;
if (attr->type == PERF_TYPE_RAW)
check_pass = true;
if (attr->type == PERF_TYPE_HARDWARE)
check_pass = true;
if (!check_pass) {
pr_debug("ERROR: Event type is wrong for map %s\n", name);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_EVTTYPE;
}
events = xy->entries / (xy->row_size / xy->entry_size);
key = *((unsigned int *)pkey);
if (key >= events) {
pr_debug("ERROR: there is no event %d for map %s\n",
key, name);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_MAPSIZE;
}
evt_fd = xyarray__entry(xy, key, 0);
err = bpf_map_update_elem(map_fd, pkey, evt_fd, BPF_ANY);
if (err && errno)
err = -errno;
return err;
}
static int
apply_obj_config_map_for_key(const char *name, int map_fd,
const struct bpf_map_def *pdef,
struct bpf_map_op *op,
void *pkey, void *arg __maybe_unused)
{
int err;
switch (op->op_type) {
case BPF_MAP_OP_SET_VALUE:
err = apply_config_value_for_key(map_fd, pkey,
pdef->value_size,
op->v.value);
break;
case BPF_MAP_OP_SET_EVSEL:
err = apply_config_evsel_for_key(name, map_fd, pkey,
op->v.evsel);
break;
default:
pr_debug("ERROR: unknown value type for '%s'\n", name);
err = -BPF_LOADER_ERRNO__INTERNAL;
}
return err;
}
static int
apply_obj_config_map(struct bpf_map *map)
{
return bpf_map_config_foreach_key(map,
apply_obj_config_map_for_key,
NULL);
}
static int
apply_obj_config_object(struct bpf_object *obj)
{
struct bpf_map *map;
int err;
bpf_object__for_each_map(map, obj) {
err = apply_obj_config_map(map);
if (err)
return err;
}
return 0;
}
int bpf__apply_obj_config(void)
{
struct bpf_object *obj, *tmp;
int err;
bpf_object__for_each_safe(obj, tmp) {
err = apply_obj_config_object(obj);
if (err)
return err;
}
return 0;
}
#define bpf__for_each_map(pos, obj, objtmp) \
bpf_object__for_each_safe(obj, objtmp) \
bpf_object__for_each_map(pos, obj)
#define bpf__for_each_map_named(pos, obj, objtmp, name) \
bpf__for_each_map(pos, obj, objtmp) \
if (bpf_map__name(pos) && \
(strcmp(name, \
bpf_map__name(pos)) == 0))
struct perf_evsel *bpf__setup_output_event(struct perf_evlist *evlist, const char *name)
{
struct bpf_map_priv *tmpl_priv = NULL;
struct bpf_object *obj, *tmp;
struct perf_evsel *evsel = NULL;
struct bpf_map *map;
int err;
bool need_init = false;
bpf__for_each_map_named(map, obj, tmp, name) {
struct bpf_map_priv *priv = bpf_map__priv(map);
if (IS_ERR(priv))
return ERR_PTR(-BPF_LOADER_ERRNO__INTERNAL);
/*
* No need to check map type: type should have been
* verified by kernel.
*/
if (!need_init && !priv)
need_init = !priv;
if (!tmpl_priv && priv)
tmpl_priv = priv;
}
if (!need_init)
return NULL;
if (!tmpl_priv) {
char *event_definition = NULL;
if (asprintf(&event_definition, "bpf-output/no-inherit=1,name=%s/", name) < 0)
return ERR_PTR(-ENOMEM);
err = parse_events(evlist, event_definition, NULL);
free(event_definition);
if (err) {
pr_debug("ERROR: failed to create the \"%s\" bpf-output event\n", name);
return ERR_PTR(-err);
}
evsel = perf_evlist__last(evlist);
}
bpf__for_each_map_named(map, obj, tmp, name) {
struct bpf_map_priv *priv = bpf_map__priv(map);
if (IS_ERR(priv))
return ERR_PTR(-BPF_LOADER_ERRNO__INTERNAL);
if (priv)
continue;
if (tmpl_priv) {
priv = bpf_map_priv__clone(tmpl_priv);
if (!priv)
return ERR_PTR(-ENOMEM);
err = bpf_map__set_priv(map, priv, bpf_map_priv__clear);
if (err) {
bpf_map_priv__clear(map, priv);
return ERR_PTR(err);
}
} else if (evsel) {
struct bpf_map_op *op;
op = bpf_map__add_newop(map, NULL);
if (IS_ERR(op))
return ERR_CAST(op);
op->op_type = BPF_MAP_OP_SET_EVSEL;
op->v.evsel = evsel;
}
}
return evsel;
}
int bpf__setup_stdout(struct perf_evlist *evlist)
{
struct perf_evsel *evsel = bpf__setup_output_event(evlist, "__bpf_stdout__");
return PTR_ERR_OR_ZERO(evsel);
}
#define ERRNO_OFFSET(e) ((e) - __BPF_LOADER_ERRNO__START)
#define ERRCODE_OFFSET(c) ERRNO_OFFSET(BPF_LOADER_ERRNO__##c)
#define NR_ERRNO (__BPF_LOADER_ERRNO__END - __BPF_LOADER_ERRNO__START)
static const char *bpf_loader_strerror_table[NR_ERRNO] = {
[ERRCODE_OFFSET(CONFIG)] = "Invalid config string",
[ERRCODE_OFFSET(GROUP)] = "Invalid group name",
[ERRCODE_OFFSET(EVENTNAME)] = "No event name found in config string",
[ERRCODE_OFFSET(INTERNAL)] = "BPF loader internal error",
[ERRCODE_OFFSET(COMPILE)] = "Error when compiling BPF scriptlet",
[ERRCODE_OFFSET(PROGCONF_TERM)] = "Invalid program config term in config string",
[ERRCODE_OFFSET(PROLOGUE)] = "Failed to generate prologue",
[ERRCODE_OFFSET(PROLOGUE2BIG)] = "Prologue too big for program",
[ERRCODE_OFFSET(PROLOGUEOOB)] = "Offset out of bound for prologue",
[ERRCODE_OFFSET(OBJCONF_OPT)] = "Invalid object config option",
[ERRCODE_OFFSET(OBJCONF_CONF)] = "Config value not set (missing '=')",
[ERRCODE_OFFSET(OBJCONF_MAP_OPT)] = "Invalid object map config option",
[ERRCODE_OFFSET(OBJCONF_MAP_NOTEXIST)] = "Target map doesn't exist",
[ERRCODE_OFFSET(OBJCONF_MAP_VALUE)] = "Incorrect value type for map",
[ERRCODE_OFFSET(OBJCONF_MAP_TYPE)] = "Incorrect map type",
[ERRCODE_OFFSET(OBJCONF_MAP_KEYSIZE)] = "Incorrect map key size",
[ERRCODE_OFFSET(OBJCONF_MAP_VALUESIZE)] = "Incorrect map value size",
[ERRCODE_OFFSET(OBJCONF_MAP_NOEVT)] = "Event not found for map setting",
[ERRCODE_OFFSET(OBJCONF_MAP_MAPSIZE)] = "Invalid map size for event setting",
[ERRCODE_OFFSET(OBJCONF_MAP_EVTDIM)] = "Event dimension too large",
[ERRCODE_OFFSET(OBJCONF_MAP_EVTINH)] = "Doesn't support inherit event",
[ERRCODE_OFFSET(OBJCONF_MAP_EVTTYPE)] = "Wrong event type for map",
[ERRCODE_OFFSET(OBJCONF_MAP_IDX2BIG)] = "Index too large",
};
static int
bpf_loader_strerror(int err, char *buf, size_t size)
{
char sbuf[STRERR_BUFSIZE];
const char *msg;
if (!buf || !size)
return -1;
err = err > 0 ? err : -err;
if (err >= __LIBBPF_ERRNO__START)
return libbpf_strerror(err, buf, size);
if (err >= __BPF_LOADER_ERRNO__START && err < __BPF_LOADER_ERRNO__END) {
msg = bpf_loader_strerror_table[ERRNO_OFFSET(err)];
snprintf(buf, size, "%s", msg);
buf[size - 1] = '\0';
return 0;
}
if (err >= __BPF_LOADER_ERRNO__END)
snprintf(buf, size, "Unknown bpf loader error %d", err);
else
snprintf(buf, size, "%s",
str_error_r(err, sbuf, sizeof(sbuf)));
buf[size - 1] = '\0';
return -1;
}
#define bpf__strerror_head(err, buf, size) \
char sbuf[STRERR_BUFSIZE], *emsg;\
if (!size)\
return 0;\
if (err < 0)\
err = -err;\
bpf_loader_strerror(err, sbuf, sizeof(sbuf));\
emsg = sbuf;\
switch (err) {\
default:\
scnprintf(buf, size, "%s", emsg);\
break;
#define bpf__strerror_entry(val, fmt...)\
case val: {\
scnprintf(buf, size, fmt);\
break;\
}
#define bpf__strerror_end(buf, size)\
}\
buf[size - 1] = '\0';
int bpf__strerror_prepare_load(const char *filename, bool source,
int err, char *buf, size_t size)
{
size_t n;
int ret;
n = snprintf(buf, size, "Failed to load %s%s: ",
filename, source ? " from source" : "");
if (n >= size) {
buf[size - 1] = '\0';
return 0;
}
buf += n;
size -= n;
ret = bpf_loader_strerror(err, buf, size);
buf[size - 1] = '\0';
return ret;
}
int bpf__strerror_probe(struct bpf_object *obj __maybe_unused,
int err, char *buf, size_t size)
{
bpf__strerror_head(err, buf, size);
case BPF_LOADER_ERRNO__PROGCONF_TERM: {
scnprintf(buf, size, "%s (add -v to see detail)", emsg);
break;
}
bpf__strerror_entry(EEXIST, "Probe point exist. Try 'perf probe -d \"*\"' and set 'force=yes'");
bpf__strerror_entry(EACCES, "You need to be root");
bpf__strerror_entry(EPERM, "You need to be root, and /proc/sys/kernel/kptr_restrict should be 0");
bpf__strerror_entry(ENOENT, "You need to check probing points in BPF file");
bpf__strerror_end(buf, size);
return 0;
}
int bpf__strerror_load(struct bpf_object *obj,
int err, char *buf, size_t size)
{
bpf__strerror_head(err, buf, size);
case LIBBPF_ERRNO__KVER: {
unsigned int obj_kver = bpf_object__kversion(obj);
unsigned int real_kver;
if (fetch_kernel_version(&real_kver, NULL, 0)) {
scnprintf(buf, size, "Unable to fetch kernel version");
break;
}
if (obj_kver != real_kver) {
scnprintf(buf, size,
"'version' ("KVER_FMT") doesn't match running kernel ("KVER_FMT")",
KVER_PARAM(obj_kver),
KVER_PARAM(real_kver));
break;
}
scnprintf(buf, size, "Failed to load program for unknown reason");
break;
}
bpf__strerror_end(buf, size);
return 0;
}
int bpf__strerror_config_obj(struct bpf_object *obj __maybe_unused,
struct parse_events_term *term __maybe_unused,
struct perf_evlist *evlist __maybe_unused,
int *error_pos __maybe_unused, int err,
char *buf, size_t size)
{
bpf__strerror_head(err, buf, size);
bpf__strerror_entry(BPF_LOADER_ERRNO__OBJCONF_MAP_TYPE,
"Can't use this config term with this map type");
bpf__strerror_end(buf, size);
return 0;
}
int bpf__strerror_apply_obj_config(int err, char *buf, size_t size)
{
bpf__strerror_head(err, buf, size);
bpf__strerror_entry(BPF_LOADER_ERRNO__OBJCONF_MAP_EVTDIM,
"Cannot set event to BPF map in multi-thread tracing");
bpf__strerror_entry(BPF_LOADER_ERRNO__OBJCONF_MAP_EVTINH,
"%s (Hint: use -i to turn off inherit)", emsg);
bpf__strerror_entry(BPF_LOADER_ERRNO__OBJCONF_MAP_EVTTYPE,
"Can only put raw, hardware and BPF output event into a BPF map");
bpf__strerror_end(buf, size);
return 0;
}
int bpf__strerror_setup_output_event(struct perf_evlist *evlist __maybe_unused,
int err, char *buf, size_t size)
{
bpf__strerror_head(err, buf, size);
bpf__strerror_end(buf, size);
return 0;
}