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   1/*
   2 * bpf-loader.c
   3 *
   4 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
   5 * Copyright (C) 2015 Huawei Inc.
   6 */
   7
   8#include <linux/bpf.h>
   9#include <bpf/libbpf.h>
  10#include <bpf/bpf.h>
  11#include <linux/err.h>
  12#include <linux/string.h>
  13#include "perf.h"
  14#include "debug.h"
  15#include "bpf-loader.h"
  16#include "bpf-prologue.h"
  17#include "llvm-utils.h"
  18#include "probe-event.h"
  19#include "probe-finder.h" // for MAX_PROBES
  20#include "parse-events.h"
  21#include "llvm-utils.h"
  22
  23#define DEFINE_PRINT_FN(name, level) \
  24static int libbpf_##name(const char *fmt, ...)	\
  25{						\
  26	va_list args;				\
  27	int ret;				\
  28						\
  29	va_start(args, fmt);			\
  30	ret = veprintf(level, verbose, pr_fmt(fmt), args);\
  31	va_end(args);				\
  32	return ret;				\
  33}
  34
  35DEFINE_PRINT_FN(warning, 1)
  36DEFINE_PRINT_FN(info, 1)
  37DEFINE_PRINT_FN(debug, 1)
  38
  39struct bpf_prog_priv {
  40	struct perf_probe_event pev;
  41	bool need_prologue;
  42	struct bpf_insn *insns_buf;
  43	int nr_types;
  44	int *type_mapping;
  45};
  46
  47static bool libbpf_initialized;
  48
  49struct bpf_object *
  50bpf__prepare_load_buffer(void *obj_buf, size_t obj_buf_sz, const char *name)
  51{
  52	struct bpf_object *obj;
  53
  54	if (!libbpf_initialized) {
  55		libbpf_set_print(libbpf_warning,
  56				 libbpf_info,
  57				 libbpf_debug);
  58		libbpf_initialized = true;
  59	}
  60
  61	obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, name);
  62	if (IS_ERR(obj)) {
  63		pr_debug("bpf: failed to load buffer\n");
  64		return ERR_PTR(-EINVAL);
  65	}
  66
  67	return obj;
  68}
  69
  70struct bpf_object *bpf__prepare_load(const char *filename, bool source)
  71{
  72	struct bpf_object *obj;
  73
  74	if (!libbpf_initialized) {
  75		libbpf_set_print(libbpf_warning,
  76				 libbpf_info,
  77				 libbpf_debug);
  78		libbpf_initialized = true;
  79	}
  80
  81	if (source) {
  82		int err;
  83		void *obj_buf;
  84		size_t obj_buf_sz;
  85
  86		err = llvm__compile_bpf(filename, &obj_buf, &obj_buf_sz);
  87		if (err)
  88			return ERR_PTR(-BPF_LOADER_ERRNO__COMPILE);
  89		obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, filename);
  90		free(obj_buf);
  91	} else
  92		obj = bpf_object__open(filename);
  93
  94	if (IS_ERR(obj)) {
  95		pr_debug("bpf: failed to load %s\n", filename);
  96		return obj;
  97	}
  98
  99	return obj;
 100}
 101
 102void bpf__clear(void)
 103{
 104	struct bpf_object *obj, *tmp;
 105
 106	bpf_object__for_each_safe(obj, tmp) {
 107		bpf__unprobe(obj);
 108		bpf_object__close(obj);
 109	}
 110}
 111
 112static void
 113clear_prog_priv(struct bpf_program *prog __maybe_unused,
 114		void *_priv)
 115{
 116	struct bpf_prog_priv *priv = _priv;
 117
 118	cleanup_perf_probe_events(&priv->pev, 1);
 119	zfree(&priv->insns_buf);
 120	zfree(&priv->type_mapping);
 121	free(priv);
 122}
 123
 124static int
 125prog_config__exec(const char *value, struct perf_probe_event *pev)
 126{
 127	pev->uprobes = true;
 128	pev->target = strdup(value);
 129	if (!pev->target)
 130		return -ENOMEM;
 131	return 0;
 132}
 133
 134static int
 135prog_config__module(const char *value, struct perf_probe_event *pev)
 136{
 137	pev->uprobes = false;
 138	pev->target = strdup(value);
 139	if (!pev->target)
 140		return -ENOMEM;
 141	return 0;
 142}
 143
 144static int
 145prog_config__bool(const char *value, bool *pbool, bool invert)
 146{
 147	int err;
 148	bool bool_value;
 149
 150	if (!pbool)
 151		return -EINVAL;
 152
 153	err = strtobool(value, &bool_value);
 154	if (err)
 155		return err;
 156
 157	*pbool = invert ? !bool_value : bool_value;
 158	return 0;
 159}
 160
 161static int
 162prog_config__inlines(const char *value,
 163		     struct perf_probe_event *pev __maybe_unused)
 164{
 165	return prog_config__bool(value, &probe_conf.no_inlines, true);
 166}
 167
 168static int
 169prog_config__force(const char *value,
 170		   struct perf_probe_event *pev __maybe_unused)
 171{
 172	return prog_config__bool(value, &probe_conf.force_add, false);
 173}
 174
 175static struct {
 176	const char *key;
 177	const char *usage;
 178	const char *desc;
 179	int (*func)(const char *, struct perf_probe_event *);
 180} bpf_prog_config_terms[] = {
 181	{
 182		.key	= "exec",
 183		.usage	= "exec=<full path of file>",
 184		.desc	= "Set uprobe target",
 185		.func	= prog_config__exec,
 186	},
 187	{
 188		.key	= "module",
 189		.usage	= "module=<module name>    ",
 190		.desc	= "Set kprobe module",
 191		.func	= prog_config__module,
 192	},
 193	{
 194		.key	= "inlines",
 195		.usage	= "inlines=[yes|no]        ",
 196		.desc	= "Probe at inline symbol",
 197		.func	= prog_config__inlines,
 198	},
 199	{
 200		.key	= "force",
 201		.usage	= "force=[yes|no]          ",
 202		.desc	= "Forcibly add events with existing name",
 203		.func	= prog_config__force,
 204	},
 205};
 206
 207static int
 208do_prog_config(const char *key, const char *value,
 209	       struct perf_probe_event *pev)
 210{
 211	unsigned int i;
 212
 213	pr_debug("config bpf program: %s=%s\n", key, value);
 214	for (i = 0; i < ARRAY_SIZE(bpf_prog_config_terms); i++)
 215		if (strcmp(key, bpf_prog_config_terms[i].key) == 0)
 216			return bpf_prog_config_terms[i].func(value, pev);
 217
 218	pr_debug("BPF: ERROR: invalid program config option: %s=%s\n",
 219		 key, value);
 220
 221	pr_debug("\nHint: Valid options are:\n");
 222	for (i = 0; i < ARRAY_SIZE(bpf_prog_config_terms); i++)
 223		pr_debug("\t%s:\t%s\n", bpf_prog_config_terms[i].usage,
 224			 bpf_prog_config_terms[i].desc);
 225	pr_debug("\n");
 226
 227	return -BPF_LOADER_ERRNO__PROGCONF_TERM;
 228}
 229
 230static const char *
 231parse_prog_config_kvpair(const char *config_str, struct perf_probe_event *pev)
 232{
 233	char *text = strdup(config_str);
 234	char *sep, *line;
 235	const char *main_str = NULL;
 236	int err = 0;
 237
 238	if (!text) {
 239		pr_debug("No enough memory: dup config_str failed\n");
 240		return ERR_PTR(-ENOMEM);
 241	}
 242
 243	line = text;
 244	while ((sep = strchr(line, ';'))) {
 245		char *equ;
 246
 247		*sep = '\0';
 248		equ = strchr(line, '=');
 249		if (!equ) {
 250			pr_warning("WARNING: invalid config in BPF object: %s\n",
 251				   line);
 252			pr_warning("\tShould be 'key=value'.\n");
 253			goto nextline;
 254		}
 255		*equ = '\0';
 256
 257		err = do_prog_config(line, equ + 1, pev);
 258		if (err)
 259			break;
 260nextline:
 261		line = sep + 1;
 262	}
 263
 264	if (!err)
 265		main_str = config_str + (line - text);
 266	free(text);
 267
 268	return err ? ERR_PTR(err) : main_str;
 269}
 270
 271static int
 272parse_prog_config(const char *config_str, struct perf_probe_event *pev)
 273{
 274	int err;
 275	const char *main_str = parse_prog_config_kvpair(config_str, pev);
 276
 277	if (IS_ERR(main_str))
 278		return PTR_ERR(main_str);
 279
 280	err = parse_perf_probe_command(main_str, pev);
 281	if (err < 0) {
 282		pr_debug("bpf: '%s' is not a valid config string\n",
 283			 config_str);
 284		/* parse failed, don't need clear pev. */
 285		return -BPF_LOADER_ERRNO__CONFIG;
 286	}
 287	return 0;
 288}
 289
 290static int
 291config_bpf_program(struct bpf_program *prog)
 292{
 293	struct perf_probe_event *pev = NULL;
 294	struct bpf_prog_priv *priv = NULL;
 295	const char *config_str;
 296	int err;
 297
 298	/* Initialize per-program probing setting */
 299	probe_conf.no_inlines = false;
 300	probe_conf.force_add = false;
 301
 302	config_str = bpf_program__title(prog, false);
 303	if (IS_ERR(config_str)) {
 304		pr_debug("bpf: unable to get title for program\n");
 305		return PTR_ERR(config_str);
 306	}
 307
 308	priv = calloc(sizeof(*priv), 1);
 309	if (!priv) {
 310		pr_debug("bpf: failed to alloc priv\n");
 311		return -ENOMEM;
 312	}
 313	pev = &priv->pev;
 314
 315	pr_debug("bpf: config program '%s'\n", config_str);
 316	err = parse_prog_config(config_str, pev);
 317	if (err)
 318		goto errout;
 319
 320	if (pev->group && strcmp(pev->group, PERF_BPF_PROBE_GROUP)) {
 321		pr_debug("bpf: '%s': group for event is set and not '%s'.\n",
 322			 config_str, PERF_BPF_PROBE_GROUP);
 323		err = -BPF_LOADER_ERRNO__GROUP;
 324		goto errout;
 325	} else if (!pev->group)
 326		pev->group = strdup(PERF_BPF_PROBE_GROUP);
 327
 328	if (!pev->group) {
 329		pr_debug("bpf: strdup failed\n");
 330		err = -ENOMEM;
 331		goto errout;
 332	}
 333
 334	if (!pev->event) {
 335		pr_debug("bpf: '%s': event name is missing. Section name should be 'key=value'\n",
 336			 config_str);
 337		err = -BPF_LOADER_ERRNO__EVENTNAME;
 338		goto errout;
 339	}
 340	pr_debug("bpf: config '%s' is ok\n", config_str);
 341
 342	err = bpf_program__set_private(prog, priv, clear_prog_priv);
 343	if (err) {
 344		pr_debug("Failed to set priv for program '%s'\n", config_str);
 345		goto errout;
 346	}
 347
 348	return 0;
 349
 350errout:
 351	if (pev)
 352		clear_perf_probe_event(pev);
 353	free(priv);
 354	return err;
 355}
 356
 357static int bpf__prepare_probe(void)
 358{
 359	static int err = 0;
 360	static bool initialized = false;
 361
 362	/*
 363	 * Make err static, so if init failed the first, bpf__prepare_probe()
 364	 * fails each time without calling init_probe_symbol_maps multiple
 365	 * times.
 366	 */
 367	if (initialized)
 368		return err;
 369
 370	initialized = true;
 371	err = init_probe_symbol_maps(false);
 372	if (err < 0)
 373		pr_debug("Failed to init_probe_symbol_maps\n");
 374	probe_conf.max_probes = MAX_PROBES;
 375	return err;
 376}
 377
 378static int
 379preproc_gen_prologue(struct bpf_program *prog, int n,
 380		     struct bpf_insn *orig_insns, int orig_insns_cnt,
 381		     struct bpf_prog_prep_result *res)
 382{
 383	struct probe_trace_event *tev;
 384	struct perf_probe_event *pev;
 385	struct bpf_prog_priv *priv;
 386	struct bpf_insn *buf;
 387	size_t prologue_cnt = 0;
 388	int i, err;
 389
 390	err = bpf_program__get_private(prog, (void **)&priv);
 391	if (err || !priv)
 392		goto errout;
 393
 394	pev = &priv->pev;
 395
 396	if (n < 0 || n >= priv->nr_types)
 397		goto errout;
 398
 399	/* Find a tev belongs to that type */
 400	for (i = 0; i < pev->ntevs; i++) {
 401		if (priv->type_mapping[i] == n)
 402			break;
 403	}
 404
 405	if (i >= pev->ntevs) {
 406		pr_debug("Internal error: prologue type %d not found\n", n);
 407		return -BPF_LOADER_ERRNO__PROLOGUE;
 408	}
 409
 410	tev = &pev->tevs[i];
 411
 412	buf = priv->insns_buf;
 413	err = bpf__gen_prologue(tev->args, tev->nargs,
 414				buf, &prologue_cnt,
 415				BPF_MAXINSNS - orig_insns_cnt);
 416	if (err) {
 417		const char *title;
 418
 419		title = bpf_program__title(prog, false);
 420		if (!title)
 421			title = "[unknown]";
 422
 423		pr_debug("Failed to generate prologue for program %s\n",
 424			 title);
 425		return err;
 426	}
 427
 428	memcpy(&buf[prologue_cnt], orig_insns,
 429	       sizeof(struct bpf_insn) * orig_insns_cnt);
 430
 431	res->new_insn_ptr = buf;
 432	res->new_insn_cnt = prologue_cnt + orig_insns_cnt;
 433	res->pfd = NULL;
 434	return 0;
 435
 436errout:
 437	pr_debug("Internal error in preproc_gen_prologue\n");
 438	return -BPF_LOADER_ERRNO__PROLOGUE;
 439}
 440
 441/*
 442 * compare_tev_args is reflexive, transitive and antisymmetric.
 443 * I can proof it but this margin is too narrow to contain.
 444 */
 445static int compare_tev_args(const void *ptev1, const void *ptev2)
 446{
 447	int i, ret;
 448	const struct probe_trace_event *tev1 =
 449		*(const struct probe_trace_event **)ptev1;
 450	const struct probe_trace_event *tev2 =
 451		*(const struct probe_trace_event **)ptev2;
 452
 453	ret = tev2->nargs - tev1->nargs;
 454	if (ret)
 455		return ret;
 456
 457	for (i = 0; i < tev1->nargs; i++) {
 458		struct probe_trace_arg *arg1, *arg2;
 459		struct probe_trace_arg_ref *ref1, *ref2;
 460
 461		arg1 = &tev1->args[i];
 462		arg2 = &tev2->args[i];
 463
 464		ret = strcmp(arg1->value, arg2->value);
 465		if (ret)
 466			return ret;
 467
 468		ref1 = arg1->ref;
 469		ref2 = arg2->ref;
 470
 471		while (ref1 && ref2) {
 472			ret = ref2->offset - ref1->offset;
 473			if (ret)
 474				return ret;
 475
 476			ref1 = ref1->next;
 477			ref2 = ref2->next;
 478		}
 479
 480		if (ref1 || ref2)
 481			return ref2 ? 1 : -1;
 482	}
 483
 484	return 0;
 485}
 486
 487/*
 488 * Assign a type number to each tevs in a pev.
 489 * mapping is an array with same slots as tevs in that pev.
 490 * nr_types will be set to number of types.
 491 */
 492static int map_prologue(struct perf_probe_event *pev, int *mapping,
 493			int *nr_types)
 494{
 495	int i, type = 0;
 496	struct probe_trace_event **ptevs;
 497
 498	size_t array_sz = sizeof(*ptevs) * pev->ntevs;
 499
 500	ptevs = malloc(array_sz);
 501	if (!ptevs) {
 502		pr_debug("No ehough memory: alloc ptevs failed\n");
 503		return -ENOMEM;
 504	}
 505
 506	pr_debug("In map_prologue, ntevs=%d\n", pev->ntevs);
 507	for (i = 0; i < pev->ntevs; i++)
 508		ptevs[i] = &pev->tevs[i];
 509
 510	qsort(ptevs, pev->ntevs, sizeof(*ptevs),
 511	      compare_tev_args);
 512
 513	for (i = 0; i < pev->ntevs; i++) {
 514		int n;
 515
 516		n = ptevs[i] - pev->tevs;
 517		if (i == 0) {
 518			mapping[n] = type;
 519			pr_debug("mapping[%d]=%d\n", n, type);
 520			continue;
 521		}
 522
 523		if (compare_tev_args(ptevs + i, ptevs + i - 1) == 0)
 524			mapping[n] = type;
 525		else
 526			mapping[n] = ++type;
 527
 528		pr_debug("mapping[%d]=%d\n", n, mapping[n]);
 529	}
 530	free(ptevs);
 531	*nr_types = type + 1;
 532
 533	return 0;
 534}
 535
 536static int hook_load_preprocessor(struct bpf_program *prog)
 537{
 538	struct perf_probe_event *pev;
 539	struct bpf_prog_priv *priv;
 540	bool need_prologue = false;
 541	int err, i;
 542
 543	err = bpf_program__get_private(prog, (void **)&priv);
 544	if (err || !priv) {
 545		pr_debug("Internal error when hook preprocessor\n");
 546		return -BPF_LOADER_ERRNO__INTERNAL;
 547	}
 548
 549	pev = &priv->pev;
 550	for (i = 0; i < pev->ntevs; i++) {
 551		struct probe_trace_event *tev = &pev->tevs[i];
 552
 553		if (tev->nargs > 0) {
 554			need_prologue = true;
 555			break;
 556		}
 557	}
 558
 559	/*
 560	 * Since all tevs don't have argument, we don't need generate
 561	 * prologue.
 562	 */
 563	if (!need_prologue) {
 564		priv->need_prologue = false;
 565		return 0;
 566	}
 567
 568	priv->need_prologue = true;
 569	priv->insns_buf = malloc(sizeof(struct bpf_insn) * BPF_MAXINSNS);
 570	if (!priv->insns_buf) {
 571		pr_debug("No enough memory: alloc insns_buf failed\n");
 572		return -ENOMEM;
 573	}
 574
 575	priv->type_mapping = malloc(sizeof(int) * pev->ntevs);
 576	if (!priv->type_mapping) {
 577		pr_debug("No enough memory: alloc type_mapping failed\n");
 578		return -ENOMEM;
 579	}
 580	memset(priv->type_mapping, -1,
 581	       sizeof(int) * pev->ntevs);
 582
 583	err = map_prologue(pev, priv->type_mapping, &priv->nr_types);
 584	if (err)
 585		return err;
 586
 587	err = bpf_program__set_prep(prog, priv->nr_types,
 588				    preproc_gen_prologue);
 589	return err;
 590}
 591
 592int bpf__probe(struct bpf_object *obj)
 593{
 594	int err = 0;
 595	struct bpf_program *prog;
 596	struct bpf_prog_priv *priv;
 597	struct perf_probe_event *pev;
 598
 599	err = bpf__prepare_probe();
 600	if (err) {
 601		pr_debug("bpf__prepare_probe failed\n");
 602		return err;
 603	}
 604
 605	bpf_object__for_each_program(prog, obj) {
 606		err = config_bpf_program(prog);
 607		if (err)
 608			goto out;
 609
 610		err = bpf_program__get_private(prog, (void **)&priv);
 611		if (err || !priv)
 612			goto out;
 613		pev = &priv->pev;
 614
 615		err = convert_perf_probe_events(pev, 1);
 616		if (err < 0) {
 617			pr_debug("bpf_probe: failed to convert perf probe events");
 618			goto out;
 619		}
 620
 621		err = apply_perf_probe_events(pev, 1);
 622		if (err < 0) {
 623			pr_debug("bpf_probe: failed to apply perf probe events");
 624			goto out;
 625		}
 626
 627		/*
 628		 * After probing, let's consider prologue, which
 629		 * adds program fetcher to BPF programs.
 630		 *
 631		 * hook_load_preprocessorr() hooks pre-processor
 632		 * to bpf_program, let it generate prologue
 633		 * dynamically during loading.
 634		 */
 635		err = hook_load_preprocessor(prog);
 636		if (err)
 637			goto out;
 638	}
 639out:
 640	return err < 0 ? err : 0;
 641}
 642
 643#define EVENTS_WRITE_BUFSIZE  4096
 644int bpf__unprobe(struct bpf_object *obj)
 645{
 646	int err, ret = 0;
 647	struct bpf_program *prog;
 648	struct bpf_prog_priv *priv;
 649
 650	bpf_object__for_each_program(prog, obj) {
 651		int i;
 652
 653		err = bpf_program__get_private(prog, (void **)&priv);
 654		if (err || !priv)
 655			continue;
 656
 657		for (i = 0; i < priv->pev.ntevs; i++) {
 658			struct probe_trace_event *tev = &priv->pev.tevs[i];
 659			char name_buf[EVENTS_WRITE_BUFSIZE];
 660			struct strfilter *delfilter;
 661
 662			snprintf(name_buf, EVENTS_WRITE_BUFSIZE,
 663				 "%s:%s", tev->group, tev->event);
 664			name_buf[EVENTS_WRITE_BUFSIZE - 1] = '\0';
 665
 666			delfilter = strfilter__new(name_buf, NULL);
 667			if (!delfilter) {
 668				pr_debug("Failed to create filter for unprobing\n");
 669				ret = -ENOMEM;
 670				continue;
 671			}
 672
 673			err = del_perf_probe_events(delfilter);
 674			strfilter__delete(delfilter);
 675			if (err) {
 676				pr_debug("Failed to delete %s\n", name_buf);
 677				ret = err;
 678				continue;
 679			}
 680		}
 681	}
 682	return ret;
 683}
 684
 685int bpf__load(struct bpf_object *obj)
 686{
 687	int err;
 688
 689	err = bpf_object__load(obj);
 690	if (err) {
 691		pr_debug("bpf: load objects failed\n");
 692		return err;
 693	}
 694	return 0;
 695}
 696
 697int bpf__foreach_tev(struct bpf_object *obj,
 698		     bpf_prog_iter_callback_t func,
 699		     void *arg)
 700{
 701	struct bpf_program *prog;
 702	int err;
 703
 704	bpf_object__for_each_program(prog, obj) {
 705		struct probe_trace_event *tev;
 706		struct perf_probe_event *pev;
 707		struct bpf_prog_priv *priv;
 708		int i, fd;
 709
 710		err = bpf_program__get_private(prog,
 711				(void **)&priv);
 712		if (err || !priv) {
 713			pr_debug("bpf: failed to get private field\n");
 714			return -BPF_LOADER_ERRNO__INTERNAL;
 715		}
 716
 717		pev = &priv->pev;
 718		for (i = 0; i < pev->ntevs; i++) {
 719			tev = &pev->tevs[i];
 720
 721			if (priv->need_prologue) {
 722				int type = priv->type_mapping[i];
 723
 724				fd = bpf_program__nth_fd(prog, type);
 725			} else {
 726				fd = bpf_program__fd(prog);
 727			}
 728
 729			if (fd < 0) {
 730				pr_debug("bpf: failed to get file descriptor\n");
 731				return fd;
 732			}
 733
 734			err = (*func)(tev, fd, arg);
 735			if (err) {
 736				pr_debug("bpf: call back failed, stop iterate\n");
 737				return err;
 738			}
 739		}
 740	}
 741	return 0;
 742}
 743
 744enum bpf_map_op_type {
 745	BPF_MAP_OP_SET_VALUE,
 746	BPF_MAP_OP_SET_EVSEL,
 747};
 748
 749enum bpf_map_key_type {
 750	BPF_MAP_KEY_ALL,
 751	BPF_MAP_KEY_RANGES,
 752};
 753
 754struct bpf_map_op {
 755	struct list_head list;
 756	enum bpf_map_op_type op_type;
 757	enum bpf_map_key_type key_type;
 758	union {
 759		struct parse_events_array array;
 760	} k;
 761	union {
 762		u64 value;
 763		struct perf_evsel *evsel;
 764	} v;
 765};
 766
 767struct bpf_map_priv {
 768	struct list_head ops_list;
 769};
 770
 771static void
 772bpf_map_op__delete(struct bpf_map_op *op)
 773{
 774	if (!list_empty(&op->list))
 775		list_del(&op->list);
 776	if (op->key_type == BPF_MAP_KEY_RANGES)
 777		parse_events__clear_array(&op->k.array);
 778	free(op);
 779}
 780
 781static void
 782bpf_map_priv__purge(struct bpf_map_priv *priv)
 783{
 784	struct bpf_map_op *pos, *n;
 785
 786	list_for_each_entry_safe(pos, n, &priv->ops_list, list) {
 787		list_del_init(&pos->list);
 788		bpf_map_op__delete(pos);
 789	}
 790}
 791
 792static void
 793bpf_map_priv__clear(struct bpf_map *map __maybe_unused,
 794		    void *_priv)
 795{
 796	struct bpf_map_priv *priv = _priv;
 797
 798	bpf_map_priv__purge(priv);
 799	free(priv);
 800}
 801
 802static int
 803bpf_map_op_setkey(struct bpf_map_op *op, struct parse_events_term *term)
 804{
 805	op->key_type = BPF_MAP_KEY_ALL;
 806	if (!term)
 807		return 0;
 808
 809	if (term->array.nr_ranges) {
 810		size_t memsz = term->array.nr_ranges *
 811				sizeof(op->k.array.ranges[0]);
 812
 813		op->k.array.ranges = memdup(term->array.ranges, memsz);
 814		if (!op->k.array.ranges) {
 815			pr_debug("No enough memory to alloc indices for map\n");
 816			return -ENOMEM;
 817		}
 818		op->key_type = BPF_MAP_KEY_RANGES;
 819		op->k.array.nr_ranges = term->array.nr_ranges;
 820	}
 821	return 0;
 822}
 823
 824static struct bpf_map_op *
 825bpf_map_op__new(struct parse_events_term *term)
 826{
 827	struct bpf_map_op *op;
 828	int err;
 829
 830	op = zalloc(sizeof(*op));
 831	if (!op) {
 832		pr_debug("Failed to alloc bpf_map_op\n");
 833		return ERR_PTR(-ENOMEM);
 834	}
 835	INIT_LIST_HEAD(&op->list);
 836
 837	err = bpf_map_op_setkey(op, term);
 838	if (err) {
 839		free(op);
 840		return ERR_PTR(err);
 841	}
 842	return op;
 843}
 844
 845static int
 846bpf_map__add_op(struct bpf_map *map, struct bpf_map_op *op)
 847{
 848	struct bpf_map_priv *priv;
 849	const char *map_name;
 850	int err;
 851
 852	map_name = bpf_map__get_name(map);
 853	err = bpf_map__get_private(map, (void **)&priv);
 854	if (err) {
 855		pr_debug("Failed to get private from map %s\n", map_name);
 856		return err;
 857	}
 858
 859	if (!priv) {
 860		priv = zalloc(sizeof(*priv));
 861		if (!priv) {
 862			pr_debug("No enough memory to alloc map private\n");
 863			return -ENOMEM;
 864		}
 865		INIT_LIST_HEAD(&priv->ops_list);
 866
 867		if (bpf_map__set_private(map, priv, bpf_map_priv__clear)) {
 868			free(priv);
 869			return -BPF_LOADER_ERRNO__INTERNAL;
 870		}
 871	}
 872
 873	list_add_tail(&op->list, &priv->ops_list);
 874	return 0;
 875}
 876
 877static struct bpf_map_op *
 878bpf_map__add_newop(struct bpf_map *map, struct parse_events_term *term)
 879{
 880	struct bpf_map_op *op;
 881	int err;
 882
 883	op = bpf_map_op__new(term);
 884	if (IS_ERR(op))
 885		return op;
 886
 887	err = bpf_map__add_op(map, op);
 888	if (err) {
 889		bpf_map_op__delete(op);
 890		return ERR_PTR(err);
 891	}
 892	return op;
 893}
 894
 895static int
 896__bpf_map__config_value(struct bpf_map *map,
 897			struct parse_events_term *term)
 898{
 899	struct bpf_map_def def;
 900	struct bpf_map_op *op;
 901	const char *map_name;
 902	int err;
 903
 904	map_name = bpf_map__get_name(map);
 905
 906	err = bpf_map__get_def(map, &def);
 907	if (err) {
 908		pr_debug("Unable to get map definition from '%s'\n",
 909			 map_name);
 910		return -BPF_LOADER_ERRNO__INTERNAL;
 911	}
 912
 913	if (def.type != BPF_MAP_TYPE_ARRAY) {
 914		pr_debug("Map %s type is not BPF_MAP_TYPE_ARRAY\n",
 915			 map_name);
 916		return -BPF_LOADER_ERRNO__OBJCONF_MAP_TYPE;
 917	}
 918	if (def.key_size < sizeof(unsigned int)) {
 919		pr_debug("Map %s has incorrect key size\n", map_name);
 920		return -BPF_LOADER_ERRNO__OBJCONF_MAP_KEYSIZE;
 921	}
 922	switch (def.value_size) {
 923	case 1:
 924	case 2:
 925	case 4:
 926	case 8:
 927		break;
 928	default:
 929		pr_debug("Map %s has incorrect value size\n", map_name);
 930		return -BPF_LOADER_ERRNO__OBJCONF_MAP_VALUESIZE;
 931	}
 932
 933	op = bpf_map__add_newop(map, term);
 934	if (IS_ERR(op))
 935		return PTR_ERR(op);
 936	op->op_type = BPF_MAP_OP_SET_VALUE;
 937	op->v.value = term->val.num;
 938	return 0;
 939}
 940
 941static int
 942bpf_map__config_value(struct bpf_map *map,
 943		      struct parse_events_term *term,
 944		      struct perf_evlist *evlist __maybe_unused)
 945{
 946	if (!term->err_val) {
 947		pr_debug("Config value not set\n");
 948		return -BPF_LOADER_ERRNO__OBJCONF_CONF;
 949	}
 950
 951	if (term->type_val != PARSE_EVENTS__TERM_TYPE_NUM) {
 952		pr_debug("ERROR: wrong value type for 'value'\n");
 953		return -BPF_LOADER_ERRNO__OBJCONF_MAP_VALUE;
 954	}
 955
 956	return __bpf_map__config_value(map, term);
 957}
 958
 959static int
 960__bpf_map__config_event(struct bpf_map *map,
 961			struct parse_events_term *term,
 962			struct perf_evlist *evlist)
 963{
 964	struct perf_evsel *evsel;
 965	struct bpf_map_def def;
 966	struct bpf_map_op *op;
 967	const char *map_name;
 968	int err;
 969
 970	map_name = bpf_map__get_name(map);
 971	evsel = perf_evlist__find_evsel_by_str(evlist, term->val.str);
 972	if (!evsel) {
 973		pr_debug("Event (for '%s') '%s' doesn't exist\n",
 974			 map_name, term->val.str);
 975		return -BPF_LOADER_ERRNO__OBJCONF_MAP_NOEVT;
 976	}
 977
 978	err = bpf_map__get_def(map, &def);
 979	if (err) {
 980		pr_debug("Unable to get map definition from '%s'\n",
 981			 map_name);
 982		return err;
 983	}
 984
 985	/*
 986	 * No need to check key_size and value_size:
 987	 * kernel has already checked them.
 988	 */
 989	if (def.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
 990		pr_debug("Map %s type is not BPF_MAP_TYPE_PERF_EVENT_ARRAY\n",
 991			 map_name);
 992		return -BPF_LOADER_ERRNO__OBJCONF_MAP_TYPE;
 993	}
 994
 995	op = bpf_map__add_newop(map, term);
 996	if (IS_ERR(op))
 997		return PTR_ERR(op);
 998	op->op_type = BPF_MAP_OP_SET_EVSEL;
 999	op->v.evsel = evsel;
1000	return 0;
1001}
1002
1003static int
1004bpf_map__config_event(struct bpf_map *map,
1005		      struct parse_events_term *term,
1006		      struct perf_evlist *evlist)
1007{
1008	if (!term->err_val) {
1009		pr_debug("Config value not set\n");
1010		return -BPF_LOADER_ERRNO__OBJCONF_CONF;
1011	}
1012
1013	if (term->type_val != PARSE_EVENTS__TERM_TYPE_STR) {
1014		pr_debug("ERROR: wrong value type for 'event'\n");
1015		return -BPF_LOADER_ERRNO__OBJCONF_MAP_VALUE;
1016	}
1017
1018	return __bpf_map__config_event(map, term, evlist);
1019}
1020
1021struct bpf_obj_config__map_func {
1022	const char *config_opt;
1023	int (*config_func)(struct bpf_map *, struct parse_events_term *,
1024			   struct perf_evlist *);
1025};
1026
1027struct bpf_obj_config__map_func bpf_obj_config__map_funcs[] = {
1028	{"value", bpf_map__config_value},
1029	{"event", bpf_map__config_event},
1030};
1031
1032static int
1033config_map_indices_range_check(struct parse_events_term *term,
1034			       struct bpf_map *map,
1035			       const char *map_name)
1036{
1037	struct parse_events_array *array = &term->array;
1038	struct bpf_map_def def;
1039	unsigned int i;
1040	int err;
1041
1042	if (!array->nr_ranges)
1043		return 0;
1044	if (!array->ranges) {
1045		pr_debug("ERROR: map %s: array->nr_ranges is %d but range array is NULL\n",
1046			 map_name, (int)array->nr_ranges);
1047		return -BPF_LOADER_ERRNO__INTERNAL;
1048	}
1049
1050	err = bpf_map__get_def(map, &def);
1051	if (err) {
1052		pr_debug("ERROR: Unable to get map definition from '%s'\n",
1053			 map_name);
1054		return -BPF_LOADER_ERRNO__INTERNAL;
1055	}
1056
1057	for (i = 0; i < array->nr_ranges; i++) {
1058		unsigned int start = array->ranges[i].start;
1059		size_t length = array->ranges[i].length;
1060		unsigned int idx = start + length - 1;
1061
1062		if (idx >= def.max_entries) {
1063			pr_debug("ERROR: index %d too large\n", idx);
1064			return -BPF_LOADER_ERRNO__OBJCONF_MAP_IDX2BIG;
1065		}
1066	}
1067	return 0;
1068}
1069
1070static int
1071bpf__obj_config_map(struct bpf_object *obj,
1072		    struct parse_events_term *term,
1073		    struct perf_evlist *evlist,
1074		    int *key_scan_pos)
1075{
1076	/* key is "map:<mapname>.<config opt>" */
1077	char *map_name = strdup(term->config + sizeof("map:") - 1);
1078	struct bpf_map *map;
1079	int err = -BPF_LOADER_ERRNO__OBJCONF_OPT;
1080	char *map_opt;
1081	size_t i;
1082
1083	if (!map_name)
1084		return -ENOMEM;
1085
1086	map_opt = strchr(map_name, '.');
1087	if (!map_opt) {
1088		pr_debug("ERROR: Invalid map config: %s\n", map_name);
1089		goto out;
1090	}
1091
1092	*map_opt++ = '\0';
1093	if (*map_opt == '\0') {
1094		pr_debug("ERROR: Invalid map option: %s\n", term->config);
1095		goto out;
1096	}
1097
1098	map = bpf_object__get_map_by_name(obj, map_name);
1099	if (!map) {
1100		pr_debug("ERROR: Map %s doesn't exist\n", map_name);
1101		err = -BPF_LOADER_ERRNO__OBJCONF_MAP_NOTEXIST;
1102		goto out;
1103	}
1104
1105	*key_scan_pos += strlen(map_opt);
1106	err = config_map_indices_range_check(term, map, map_name);
1107	if (err)
1108		goto out;
1109	*key_scan_pos -= strlen(map_opt);
1110
1111	for (i = 0; i < ARRAY_SIZE(bpf_obj_config__map_funcs); i++) {
1112		struct bpf_obj_config__map_func *func =
1113				&bpf_obj_config__map_funcs[i];
1114
1115		if (strcmp(map_opt, func->config_opt) == 0) {
1116			err = func->config_func(map, term, evlist);
1117			goto out;
1118		}
1119	}
1120
1121	pr_debug("ERROR: Invalid map config option '%s'\n", map_opt);
1122	err = -BPF_LOADER_ERRNO__OBJCONF_MAP_OPT;
1123out:
1124	free(map_name);
1125	if (!err)
1126		key_scan_pos += strlen(map_opt);
1127	return err;
1128}
1129
1130int bpf__config_obj(struct bpf_object *obj,
1131		    struct parse_events_term *term,
1132		    struct perf_evlist *evlist,
1133		    int *error_pos)
1134{
1135	int key_scan_pos = 0;
1136	int err;
1137
1138	if (!obj || !term || !term->config)
1139		return -EINVAL;
1140
1141	if (!prefixcmp(term->config, "map:")) {
1142		key_scan_pos = sizeof("map:") - 1;
1143		err = bpf__obj_config_map(obj, term, evlist, &key_scan_pos);
1144		goto out;
1145	}
1146	err = -BPF_LOADER_ERRNO__OBJCONF_OPT;
1147out:
1148	if (error_pos)
1149		*error_pos = key_scan_pos;
1150	return err;
1151
1152}
1153
1154typedef int (*map_config_func_t)(const char *name, int map_fd,
1155				 struct bpf_map_def *pdef,
1156				 struct bpf_map_op *op,
1157				 void *pkey, void *arg);
1158
1159static int
1160foreach_key_array_all(map_config_func_t func,
1161		      void *arg, const char *name,
1162		      int map_fd, struct bpf_map_def *pdef,
1163		      struct bpf_map_op *op)
1164{
1165	unsigned int i;
1166	int err;
1167
1168	for (i = 0; i < pdef->max_entries; i++) {
1169		err = func(name, map_fd, pdef, op, &i, arg);
1170		if (err) {
1171			pr_debug("ERROR: failed to insert value to %s[%u]\n",
1172				 name, i);
1173			return err;
1174		}
1175	}
1176	return 0;
1177}
1178
1179static int
1180foreach_key_array_ranges(map_config_func_t func, void *arg,
1181			 const char *name, int map_fd,
1182			 struct bpf_map_def *pdef,
1183			 struct bpf_map_op *op)
1184{
1185	unsigned int i, j;
1186	int err;
1187
1188	for (i = 0; i < op->k.array.nr_ranges; i++) {
1189		unsigned int start = op->k.array.ranges[i].start;
1190		size_t length = op->k.array.ranges[i].length;
1191
1192		for (j = 0; j < length; j++) {
1193			unsigned int idx = start + j;
1194
1195			err = func(name, map_fd, pdef, op, &idx, arg);
1196			if (err) {
1197				pr_debug("ERROR: failed to insert value to %s[%u]\n",
1198					 name, idx);
1199				return err;
1200			}
1201		}
1202	}
1203	return 0;
1204}
1205
1206static int
1207bpf_map_config_foreach_key(struct bpf_map *map,
1208			   map_config_func_t func,
1209			   void *arg)
1210{
1211	int err, map_fd;
1212	const char *name;
1213	struct bpf_map_op *op;
1214	struct bpf_map_def def;
1215	struct bpf_map_priv *priv;
1216
1217	name = bpf_map__get_name(map);
1218
1219	err = bpf_map__get_private(map, (void **)&priv);
1220	if (err) {
1221		pr_debug("ERROR: failed to get private from map %s\n", name);
1222		return -BPF_LOADER_ERRNO__INTERNAL;
1223	}
1224	if (!priv || list_empty(&priv->ops_list)) {
1225		pr_debug("INFO: nothing to config for map %s\n", name);
1226		return 0;
1227	}
1228
1229	err = bpf_map__get_def(map, &def);
1230	if (err) {
1231		pr_debug("ERROR: failed to get definition from map %s\n", name);
1232		return -BPF_LOADER_ERRNO__INTERNAL;
1233	}
1234	map_fd = bpf_map__get_fd(map);
1235	if (map_fd < 0) {
1236		pr_debug("ERROR: failed to get fd from map %s\n", name);
1237		return map_fd;
1238	}
1239
1240	list_for_each_entry(op, &priv->ops_list, list) {
1241		switch (def.type) {
1242		case BPF_MAP_TYPE_ARRAY:
1243		case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
1244			switch (op->key_type) {
1245			case BPF_MAP_KEY_ALL:
1246				err = foreach_key_array_all(func, arg, name,
1247							    map_fd, &def, op);
1248				break;
1249			case BPF_MAP_KEY_RANGES:
1250				err = foreach_key_array_ranges(func, arg, name,
1251							       map_fd, &def,
1252							       op);
1253				break;
1254			default:
1255				pr_debug("ERROR: keytype for map '%s' invalid\n",
1256					 name);
1257				return -BPF_LOADER_ERRNO__INTERNAL;
1258			}
1259			if (err)
1260				return err;
1261			break;
1262		default:
1263			pr_debug("ERROR: type of '%s' incorrect\n", name);
1264			return -BPF_LOADER_ERRNO__OBJCONF_MAP_TYPE;
1265		}
1266	}
1267
1268	return 0;
1269}
1270
1271static int
1272apply_config_value_for_key(int map_fd, void *pkey,
1273			   size_t val_size, u64 val)
1274{
1275	int err = 0;
1276
1277	switch (val_size) {
1278	case 1: {
1279		u8 _val = (u8)(val);
1280		err = bpf_map_update_elem(map_fd, pkey, &_val, BPF_ANY);
1281		break;
1282	}
1283	case 2: {
1284		u16 _val = (u16)(val);
1285		err = bpf_map_update_elem(map_fd, pkey, &_val, BPF_ANY);
1286		break;
1287	}
1288	case 4: {
1289		u32 _val = (u32)(val);
1290		err = bpf_map_update_elem(map_fd, pkey, &_val, BPF_ANY);
1291		break;
1292	}
1293	case 8: {
1294		err = bpf_map_update_elem(map_fd, pkey, &val, BPF_ANY);
1295		break;
1296	}
1297	default:
1298		pr_debug("ERROR: invalid value size\n");
1299		return -BPF_LOADER_ERRNO__OBJCONF_MAP_VALUESIZE;
1300	}
1301	if (err && errno)
1302		err = -errno;
1303	return err;
1304}
1305
1306static int
1307apply_config_evsel_for_key(const char *name, int map_fd, void *pkey,
1308			   struct perf_evsel *evsel)
1309{
1310	struct xyarray *xy = evsel->fd;
1311	struct perf_event_attr *attr;
1312	unsigned int key, events;
1313	bool check_pass = false;
1314	int *evt_fd;
1315	int err;
1316
1317	if (!xy) {
1318		pr_debug("ERROR: evsel not ready for map %s\n", name);
1319		return -BPF_LOADER_ERRNO__INTERNAL;
1320	}
1321
1322	if (xy->row_size / xy->entry_size != 1) {
1323		pr_debug("ERROR: Dimension of target event is incorrect for map %s\n",
1324			 name);
1325		return -BPF_LOADER_ERRNO__OBJCONF_MAP_EVTDIM;
1326	}
1327
1328	attr = &evsel->attr;
1329	if (attr->inherit) {
1330		pr_debug("ERROR: Can't put inherit event into map %s\n", name);
1331		return -BPF_LOADER_ERRNO__OBJCONF_MAP_EVTINH;
1332	}
1333
1334	if (perf_evsel__is_bpf_output(evsel))
1335		check_pass = true;
1336	if (attr->type == PERF_TYPE_RAW)
1337		check_pass = true;
1338	if (attr->type == PERF_TYPE_HARDWARE)
1339		check_pass = true;
1340	if (!check_pass) {
1341		pr_debug("ERROR: Event type is wrong for map %s\n", name);
1342		return -BPF_LOADER_ERRNO__OBJCONF_MAP_EVTTYPE;
1343	}
1344
1345	events = xy->entries / (xy->row_size / xy->entry_size);
1346	key = *((unsigned int *)pkey);
1347	if (key >= events) {
1348		pr_debug("ERROR: there is no event %d for map %s\n",
1349			 key, name);
1350		return -BPF_LOADER_ERRNO__OBJCONF_MAP_MAPSIZE;
1351	}
1352	evt_fd = xyarray__entry(xy, key, 0);
1353	err = bpf_map_update_elem(map_fd, pkey, evt_fd, BPF_ANY);
1354	if (err && errno)
1355		err = -errno;
1356	return err;
1357}
1358
1359static int
1360apply_obj_config_map_for_key(const char *name, int map_fd,
1361			     struct bpf_map_def *pdef __maybe_unused,
1362			     struct bpf_map_op *op,
1363			     void *pkey, void *arg __maybe_unused)
1364{
1365	int err;
1366
1367	switch (op->op_type) {
1368	case BPF_MAP_OP_SET_VALUE:
1369		err = apply_config_value_for_key(map_fd, pkey,
1370						 pdef->value_size,
1371						 op->v.value);
1372		break;
1373	case BPF_MAP_OP_SET_EVSEL:
1374		err = apply_config_evsel_for_key(name, map_fd, pkey,
1375						 op->v.evsel);
1376		break;
1377	default:
1378		pr_debug("ERROR: unknown value type for '%s'\n", name);
1379		err = -BPF_LOADER_ERRNO__INTERNAL;
1380	}
1381	return err;
1382}
1383
1384static int
1385apply_obj_config_map(struct bpf_map *map)
1386{
1387	return bpf_map_config_foreach_key(map,
1388					  apply_obj_config_map_for_key,
1389					  NULL);
1390}
1391
1392static int
1393apply_obj_config_object(struct bpf_object *obj)
1394{
1395	struct bpf_map *map;
1396	int err;
1397
1398	bpf_map__for_each(map, obj) {
1399		err = apply_obj_config_map(map);
1400		if (err)
1401			return err;
1402	}
1403	return 0;
1404}
1405
1406int bpf__apply_obj_config(void)
1407{
1408	struct bpf_object *obj, *tmp;
1409	int err;
1410
1411	bpf_object__for_each_safe(obj, tmp) {
1412		err = apply_obj_config_object(obj);
1413		if (err)
1414			return err;
1415	}
1416
1417	return 0;
1418}
1419
1420#define ERRNO_OFFSET(e)		((e) - __BPF_LOADER_ERRNO__START)
1421#define ERRCODE_OFFSET(c)	ERRNO_OFFSET(BPF_LOADER_ERRNO__##c)
1422#define NR_ERRNO	(__BPF_LOADER_ERRNO__END - __BPF_LOADER_ERRNO__START)
1423
1424static const char *bpf_loader_strerror_table[NR_ERRNO] = {
1425	[ERRCODE_OFFSET(CONFIG)]	= "Invalid config string",
1426	[ERRCODE_OFFSET(GROUP)]		= "Invalid group name",
1427	[ERRCODE_OFFSET(EVENTNAME)]	= "No event name found in config string",
1428	[ERRCODE_OFFSET(INTERNAL)]	= "BPF loader internal error",
1429	[ERRCODE_OFFSET(COMPILE)]	= "Error when compiling BPF scriptlet",
1430	[ERRCODE_OFFSET(PROGCONF_TERM)]	= "Invalid program config term in config string",
1431	[ERRCODE_OFFSET(PROLOGUE)]	= "Failed to generate prologue",
1432	[ERRCODE_OFFSET(PROLOGUE2BIG)]	= "Prologue too big for program",
1433	[ERRCODE_OFFSET(PROLOGUEOOB)]	= "Offset out of bound for prologue",
1434	[ERRCODE_OFFSET(OBJCONF_OPT)]	= "Invalid object config option",
1435	[ERRCODE_OFFSET(OBJCONF_CONF)]	= "Config value not set (missing '=')",
1436	[ERRCODE_OFFSET(OBJCONF_MAP_OPT)]	= "Invalid object map config option",
1437	[ERRCODE_OFFSET(OBJCONF_MAP_NOTEXIST)]	= "Target map doesn't exist",
1438	[ERRCODE_OFFSET(OBJCONF_MAP_VALUE)]	= "Incorrect value type for map",
1439	[ERRCODE_OFFSET(OBJCONF_MAP_TYPE)]	= "Incorrect map type",
1440	[ERRCODE_OFFSET(OBJCONF_MAP_KEYSIZE)]	= "Incorrect map key size",
1441	[ERRCODE_OFFSET(OBJCONF_MAP_VALUESIZE)]	= "Incorrect map value size",
1442	[ERRCODE_OFFSET(OBJCONF_MAP_NOEVT)]	= "Event not found for map setting",
1443	[ERRCODE_OFFSET(OBJCONF_MAP_MAPSIZE)]	= "Invalid map size for event setting",
1444	[ERRCODE_OFFSET(OBJCONF_MAP_EVTDIM)]	= "Event dimension too large",
1445	[ERRCODE_OFFSET(OBJCONF_MAP_EVTINH)]	= "Doesn't support inherit event",
1446	[ERRCODE_OFFSET(OBJCONF_MAP_EVTTYPE)]	= "Wrong event type for map",
1447	[ERRCODE_OFFSET(OBJCONF_MAP_IDX2BIG)]	= "Index too large",
1448};
1449
1450static int
1451bpf_loader_strerror(int err, char *buf, size_t size)
1452{
1453	char sbuf[STRERR_BUFSIZE];
1454	const char *msg;
1455
1456	if (!buf || !size)
1457		return -1;
1458
1459	err = err > 0 ? err : -err;
1460
1461	if (err >= __LIBBPF_ERRNO__START)
1462		return libbpf_strerror(err, buf, size);
1463
1464	if (err >= __BPF_LOADER_ERRNO__START && err < __BPF_LOADER_ERRNO__END) {
1465		msg = bpf_loader_strerror_table[ERRNO_OFFSET(err)];
1466		snprintf(buf, size, "%s", msg);
1467		buf[size - 1] = '\0';
1468		return 0;
1469	}
1470
1471	if (err >= __BPF_LOADER_ERRNO__END)
1472		snprintf(buf, size, "Unknown bpf loader error %d", err);
1473	else
1474		snprintf(buf, size, "%s",
1475			 strerror_r(err, sbuf, sizeof(sbuf)));
1476
1477	buf[size - 1] = '\0';
1478	return -1;
1479}
1480
1481#define bpf__strerror_head(err, buf, size) \
1482	char sbuf[STRERR_BUFSIZE], *emsg;\
1483	if (!size)\
1484		return 0;\
1485	if (err < 0)\
1486		err = -err;\
1487	bpf_loader_strerror(err, sbuf, sizeof(sbuf));\
1488	emsg = sbuf;\
1489	switch (err) {\
1490	default:\
1491		scnprintf(buf, size, "%s", emsg);\
1492		break;
1493
1494#define bpf__strerror_entry(val, fmt...)\
1495	case val: {\
1496		scnprintf(buf, size, fmt);\
1497		break;\
1498	}
1499
1500#define bpf__strerror_end(buf, size)\
1501	}\
1502	buf[size - 1] = '\0';
1503
1504int bpf__strerror_prepare_load(const char *filename, bool source,
1505			       int err, char *buf, size_t size)
1506{
1507	size_t n;
1508	int ret;
1509
1510	n = snprintf(buf, size, "Failed to load %s%s: ",
1511			 filename, source ? " from source" : "");
1512	if (n >= size) {
1513		buf[size - 1] = '\0';
1514		return 0;
1515	}
1516	buf += n;
1517	size -= n;
1518
1519	ret = bpf_loader_strerror(err, buf, size);
1520	buf[size - 1] = '\0';
1521	return ret;
1522}
1523
1524int bpf__strerror_probe(struct bpf_object *obj __maybe_unused,
1525			int err, char *buf, size_t size)
1526{
1527	bpf__strerror_head(err, buf, size);
1528	case BPF_LOADER_ERRNO__PROGCONF_TERM: {
1529		scnprintf(buf, size, "%s (add -v to see detail)", emsg);
1530		break;
1531	}
1532	bpf__strerror_entry(EEXIST, "Probe point exist. Try 'perf probe -d \"*\"' and set 'force=yes'");
1533	bpf__strerror_entry(EACCES, "You need to be root");
1534	bpf__strerror_entry(EPERM, "You need to be root, and /proc/sys/kernel/kptr_restrict should be 0");
1535	bpf__strerror_entry(ENOENT, "You need to check probing points in BPF file");
1536	bpf__strerror_end(buf, size);
1537	return 0;
1538}
1539
1540int bpf__strerror_load(struct bpf_object *obj,
1541		       int err, char *buf, size_t size)
1542{
1543	bpf__strerror_head(err, buf, size);
1544	case LIBBPF_ERRNO__KVER: {
1545		unsigned int obj_kver = bpf_object__get_kversion(obj);
1546		unsigned int real_kver;
1547
1548		if (fetch_kernel_version(&real_kver, NULL, 0)) {
1549			scnprintf(buf, size, "Unable to fetch kernel version");
1550			break;
1551		}
1552
1553		if (obj_kver != real_kver) {
1554			scnprintf(buf, size,
1555				  "'version' ("KVER_FMT") doesn't match running kernel ("KVER_FMT")",
1556				  KVER_PARAM(obj_kver),
1557				  KVER_PARAM(real_kver));
1558			break;
1559		}
1560
1561		scnprintf(buf, size, "Failed to load program for unknown reason");
1562		break;
1563	}
1564	bpf__strerror_end(buf, size);
1565	return 0;
1566}
1567
1568int bpf__strerror_config_obj(struct bpf_object *obj __maybe_unused,
1569			     struct parse_events_term *term __maybe_unused,
1570			     struct perf_evlist *evlist __maybe_unused,
1571			     int *error_pos __maybe_unused, int err,
1572			     char *buf, size_t size)
1573{
1574	bpf__strerror_head(err, buf, size);
1575	bpf__strerror_entry(BPF_LOADER_ERRNO__OBJCONF_MAP_TYPE,
1576			    "Can't use this config term with this map type");
1577	bpf__strerror_end(buf, size);
1578	return 0;
1579}
1580
1581int bpf__strerror_apply_obj_config(int err, char *buf, size_t size)
1582{
1583	bpf__strerror_head(err, buf, size);
1584	bpf__strerror_entry(BPF_LOADER_ERRNO__OBJCONF_MAP_EVTDIM,
1585			    "Cannot set event to BPF map in multi-thread tracing");
1586	bpf__strerror_entry(BPF_LOADER_ERRNO__OBJCONF_MAP_EVTINH,
1587			    "%s (Hint: use -i to turn off inherit)", emsg);
1588	bpf__strerror_entry(BPF_LOADER_ERRNO__OBJCONF_MAP_EVTTYPE,
1589			    "Can only put raw, hardware and BPF output event into a BPF map");
1590	bpf__strerror_end(buf, size);
1591	return 0;
1592}