summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/bpf/test_progs.c
blob: cc1cd240445d27fedb5f27ecaa6e0472601cabc9 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2017 Facebook
 */
#define _GNU_SOURCE
#include "test_progs.h"
#include "cgroup_helpers.h"
#include "bpf_rlimit.h"
#include <argp.h>
#include <pthread.h>
#include <sched.h>
#include <signal.h>
#include <string.h>
#include <execinfo.h> /* backtrace */
#include <linux/membarrier.h>

/* Adapted from perf/util/string.c */
static bool glob_match(const char *str, const char *pat)
{
	while (*str && *pat && *pat != '*') {
		if (*str != *pat)
			return false;
		str++;
		pat++;
	}
	/* Check wild card */
	if (*pat == '*') {
		while (*pat == '*')
			pat++;
		if (!*pat) /* Tail wild card matches all */
			return true;
		while (*str)
			if (glob_match(str++, pat))
				return true;
	}
	return !*str && !*pat;
}

#define EXIT_NO_TEST		2
#define EXIT_ERR_SETUP_INFRA	3

/* defined in test_progs.h */
struct test_env env = {};

struct prog_test_def {
	const char *test_name;
	int test_num;
	void (*run_test)(void);
	bool force_log;
	int error_cnt;
	int skip_cnt;
	bool tested;
	bool need_cgroup_cleanup;

	char *subtest_name;
	int subtest_num;

	/* store counts before subtest started */
	int old_error_cnt;
};

/* Override C runtime library's usleep() implementation to ensure nanosleep()
 * is always called. Usleep is frequently used in selftests as a way to
 * trigger kprobe and tracepoints.
 */
int usleep(useconds_t usec)
{
	struct timespec ts = {
		.tv_sec = usec / 1000000,
		.tv_nsec = (usec % 1000000) * 1000,
	};

	return syscall(__NR_nanosleep, &ts, NULL);
}

static bool should_run(struct test_selector *sel, int num, const char *name)
{
	int i;

	for (i = 0; i < sel->blacklist.cnt; i++) {
		if (glob_match(name, sel->blacklist.strs[i]))
			return false;
	}

	for (i = 0; i < sel->whitelist.cnt; i++) {
		if (glob_match(name, sel->whitelist.strs[i]))
			return true;
	}

	if (!sel->whitelist.cnt && !sel->num_set)
		return true;

	return num < sel->num_set_len && sel->num_set[num];
}

static void dump_test_log(const struct prog_test_def *test, bool failed)
{
	if (stdout == env.stdout)
		return;

	fflush(stdout); /* exports env.log_buf & env.log_cnt */

	if (env.verbosity > VERBOSE_NONE || test->force_log || failed) {
		if (env.log_cnt) {
			env.log_buf[env.log_cnt] = '\0';
			fprintf(env.stdout, "%s", env.log_buf);
			if (env.log_buf[env.log_cnt - 1] != '\n')
				fprintf(env.stdout, "\n");
		}
	}

	fseeko(stdout, 0, SEEK_SET); /* rewind */
}

static void skip_account(void)
{
	if (env.test->skip_cnt) {
		env.skip_cnt++;
		env.test->skip_cnt = 0;
	}
}

static void stdio_restore(void);

/* A bunch of tests set custom affinity per-thread and/or per-process. Reset
 * it after each test/sub-test.
 */
static void reset_affinity() {

	cpu_set_t cpuset;
	int i, err;

	CPU_ZERO(&cpuset);
	for (i = 0; i < env.nr_cpus; i++)
		CPU_SET(i, &cpuset);

	err = sched_setaffinity(0, sizeof(cpuset), &cpuset);
	if (err < 0) {
		stdio_restore();
		fprintf(stderr, "Failed to reset process affinity: %d!\n", err);
		exit(EXIT_ERR_SETUP_INFRA);
	}
	err = pthread_setaffinity_np(pthread_self(), sizeof(cpuset), &cpuset);
	if (err < 0) {
		stdio_restore();
		fprintf(stderr, "Failed to reset thread affinity: %d!\n", err);
		exit(EXIT_ERR_SETUP_INFRA);
	}
}

static void save_netns(void)
{
	env.saved_netns_fd = open("/proc/self/ns/net", O_RDONLY);
	if (env.saved_netns_fd == -1) {
		perror("open(/proc/self/ns/net)");
		exit(EXIT_ERR_SETUP_INFRA);
	}
}

static void restore_netns(void)
{
	if (setns(env.saved_netns_fd, CLONE_NEWNET) == -1) {
		stdio_restore();
		perror("setns(CLONE_NEWNS)");
		exit(EXIT_ERR_SETUP_INFRA);
	}
}

void test__end_subtest()
{
	struct prog_test_def *test = env.test;
	int sub_error_cnt = test->error_cnt - test->old_error_cnt;

	dump_test_log(test, sub_error_cnt);

	fprintf(env.stdout, "#%d/%d %s/%s:%s\n",
	       test->test_num, test->subtest_num, test->test_name, test->subtest_name,
	       sub_error_cnt ? "FAIL" : (test->skip_cnt ? "SKIP" : "OK"));

	if (sub_error_cnt)
		env.fail_cnt++;
	else if (test->skip_cnt == 0)
		env.sub_succ_cnt++;
	skip_account();

	free(test->subtest_name);
	test->subtest_name = NULL;
}

bool test__start_subtest(const char *name)
{
	struct prog_test_def *test = env.test;

	if (test->subtest_name)
		test__end_subtest();

	test->subtest_num++;

	if (!name || !name[0]) {
		fprintf(env.stderr,
			"Subtest #%d didn't provide sub-test name!\n",
			test->subtest_num);
		return false;
	}

	if (!should_run(&env.subtest_selector, test->subtest_num, name))
		return false;

	test->subtest_name = strdup(name);
	if (!test->subtest_name) {
		fprintf(env.stderr,
			"Subtest #%d: failed to copy subtest name!\n",
			test->subtest_num);
		return false;
	}
	env.test->old_error_cnt = env.test->error_cnt;

	return true;
}

void test__force_log() {
	env.test->force_log = true;
}

void test__skip(void)
{
	env.test->skip_cnt++;
}

void test__fail(void)
{
	env.test->error_cnt++;
}

int test__join_cgroup(const char *path)
{
	int fd;

	if (!env.test->need_cgroup_cleanup) {
		if (setup_cgroup_environment()) {
			fprintf(stderr,
				"#%d %s: Failed to setup cgroup environment\n",
				env.test->test_num, env.test->test_name);
			return -1;
		}

		env.test->need_cgroup_cleanup = true;
	}

	fd = create_and_get_cgroup(path);
	if (fd < 0) {
		fprintf(stderr,
			"#%d %s: Failed to create cgroup '%s' (errno=%d)\n",
			env.test->test_num, env.test->test_name, path, errno);
		return fd;
	}

	if (join_cgroup(path)) {
		fprintf(stderr,
			"#%d %s: Failed to join cgroup '%s' (errno=%d)\n",
			env.test->test_num, env.test->test_name, path, errno);
		return -1;
	}

	return fd;
}

int bpf_find_map(const char *test, struct bpf_object *obj, const char *name)
{
	struct bpf_map *map;

	map = bpf_object__find_map_by_name(obj, name);
	if (!map) {
		fprintf(stdout, "%s:FAIL:map '%s' not found\n", test, name);
		test__fail();
		return -1;
	}
	return bpf_map__fd(map);
}

static bool is_jit_enabled(void)
{
	const char *jit_sysctl = "/proc/sys/net/core/bpf_jit_enable";
	bool enabled = false;
	int sysctl_fd;

	sysctl_fd = open(jit_sysctl, 0, O_RDONLY);
	if (sysctl_fd != -1) {
		char tmpc;

		if (read(sysctl_fd, &tmpc, sizeof(tmpc)) == 1)
			enabled = (tmpc != '0');
		close(sysctl_fd);
	}

	return enabled;
}

int compare_map_keys(int map1_fd, int map2_fd)
{
	__u32 key, next_key;
	char val_buf[PERF_MAX_STACK_DEPTH *
		     sizeof(struct bpf_stack_build_id)];
	int err;

	err = bpf_map_get_next_key(map1_fd, NULL, &key);
	if (err)
		return err;
	err = bpf_map_lookup_elem(map2_fd, &key, val_buf);
	if (err)
		return err;

	while (bpf_map_get_next_key(map1_fd, &key, &next_key) == 0) {
		err = bpf_map_lookup_elem(map2_fd, &next_key, val_buf);
		if (err)
			return err;

		key = next_key;
	}
	if (errno != ENOENT)
		return -1;

	return 0;
}

int compare_stack_ips(int smap_fd, int amap_fd, int stack_trace_len)
{
	__u32 key, next_key, *cur_key_p, *next_key_p;
	char *val_buf1, *val_buf2;
	int i, err = 0;

	val_buf1 = malloc(stack_trace_len);
	val_buf2 = malloc(stack_trace_len);
	cur_key_p = NULL;
	next_key_p = &key;
	while (bpf_map_get_next_key(smap_fd, cur_key_p, next_key_p) == 0) {
		err = bpf_map_lookup_elem(smap_fd, next_key_p, val_buf1);
		if (err)
			goto out;
		err = bpf_map_lookup_elem(amap_fd, next_key_p, val_buf2);
		if (err)
			goto out;
		for (i = 0; i < stack_trace_len; i++) {
			if (val_buf1[i] != val_buf2[i]) {
				err = -1;
				goto out;
			}
		}
		key = *next_key_p;
		cur_key_p = &key;
		next_key_p = &next_key;
	}
	if (errno != ENOENT)
		err = -1;

out:
	free(val_buf1);
	free(val_buf2);
	return err;
}

int extract_build_id(char *build_id, size_t size)
{
	FILE *fp;
	char *line = NULL;
	size_t len = 0;

	fp = popen("readelf -n ./urandom_read | grep 'Build ID'", "r");
	if (fp == NULL)
		return -1;

	if (getline(&line, &len, fp) == -1)
		goto err;
	fclose(fp);

	if (len > size)
		len = size;
	memcpy(build_id, line, len);
	build_id[len] = '\0';
	free(line);
	return 0;
err:
	fclose(fp);
	return -1;
}

static int finit_module(int fd, const char *param_values, int flags)
{
	return syscall(__NR_finit_module, fd, param_values, flags);
}

static int delete_module(const char *name, int flags)
{
	return syscall(__NR_delete_module, name, flags);
}

/*
 * Trigger synchronize_rcu() in kernel.
 */
int kern_sync_rcu(void)
{
	return syscall(__NR_membarrier, MEMBARRIER_CMD_SHARED, 0, 0);
}

static void unload_bpf_testmod(void)
{
	if (kern_sync_rcu())
		fprintf(env.stderr, "Failed to trigger kernel-side RCU sync!\n");
	if (delete_module("bpf_testmod", 0)) {
		if (errno == ENOENT) {
			if (env.verbosity > VERBOSE_NONE)
				fprintf(stdout, "bpf_testmod.ko is already unloaded.\n");
			return;
		}
		fprintf(env.stderr, "Failed to unload bpf_testmod.ko from kernel: %d\n", -errno);
		return;
	}
	if (env.verbosity > VERBOSE_NONE)
		fprintf(stdout, "Successfully unloaded bpf_testmod.ko.\n");
}

static int load_bpf_testmod(void)
{
	int fd;

	/* ensure previous instance of the module is unloaded */
	unload_bpf_testmod();

	if (env.verbosity > VERBOSE_NONE)
		fprintf(stdout, "Loading bpf_testmod.ko...\n");

	fd = open("bpf_testmod.ko", O_RDONLY);
	if (fd < 0) {
		fprintf(env.stderr, "Can't find bpf_testmod.ko kernel module: %d\n", -errno);
		return -ENOENT;
	}
	if (finit_module(fd, "", 0)) {
		fprintf(env.stderr, "Failed to load bpf_testmod.ko into the kernel: %d\n", -errno);
		close(fd);
		return -EINVAL;
	}
	close(fd);

	if (env.verbosity > VERBOSE_NONE)
		fprintf(stdout, "Successfully loaded bpf_testmod.ko.\n");
	return 0;
}

/* extern declarations for test funcs */
#define DEFINE_TEST(name) extern void test_##name(void);
#include <prog_tests/tests.h>
#undef DEFINE_TEST

static struct prog_test_def prog_test_defs[] = {
#define DEFINE_TEST(name) {		\
	.test_name = #name,		\
	.run_test = &test_##name,	\
},
#include <prog_tests/tests.h>
#undef DEFINE_TEST
};
const int prog_test_cnt = ARRAY_SIZE(prog_test_defs);

const char *argp_program_version = "test_progs 0.1";
const char *argp_program_bug_address = "<bpf@vger.kernel.org>";
const char argp_program_doc[] = "BPF selftests test runner";

enum ARG_KEYS {
	ARG_TEST_NUM = 'n',
	ARG_TEST_NAME = 't',
	ARG_TEST_NAME_BLACKLIST = 'b',
	ARG_VERIFIER_STATS = 's',
	ARG_VERBOSE = 'v',
	ARG_GET_TEST_CNT = 'c',
	ARG_LIST_TEST_NAMES = 'l',
	ARG_TEST_NAME_GLOB_ALLOWLIST = 'a',
	ARG_TEST_NAME_GLOB_DENYLIST = 'd',
};

static const struct argp_option opts[] = {
	{ "num", ARG_TEST_NUM, "NUM", 0,
	  "Run test number NUM only " },
	{ "name", ARG_TEST_NAME, "NAMES", 0,
	  "Run tests with names containing any string from NAMES list" },
	{ "name-blacklist", ARG_TEST_NAME_BLACKLIST, "NAMES", 0,
	  "Don't run tests with names containing any string from NAMES list" },
	{ "verifier-stats", ARG_VERIFIER_STATS, NULL, 0,
	  "Output verifier statistics", },
	{ "verbose", ARG_VERBOSE, "LEVEL", OPTION_ARG_OPTIONAL,
	  "Verbose output (use -vv or -vvv for progressively verbose output)" },
	{ "count", ARG_GET_TEST_CNT, NULL, 0,
	  "Get number of selected top-level tests " },
	{ "list", ARG_LIST_TEST_NAMES, NULL, 0,
	  "List test names that would run (without running them) " },
	{ "allow", ARG_TEST_NAME_GLOB_ALLOWLIST, "NAMES", 0,
	  "Run tests with name matching the pattern (supports '*' wildcard)." },
	{ "deny", ARG_TEST_NAME_GLOB_DENYLIST, "NAMES", 0,
	  "Don't run tests with name matching the pattern (supports '*' wildcard)." },
	{},
};

static int libbpf_print_fn(enum libbpf_print_level level,
			   const char *format, va_list args)
{
	if (env.verbosity < VERBOSE_VERY && level == LIBBPF_DEBUG)
		return 0;
	vfprintf(stdout, format, args);
	return 0;
}

static void free_str_set(const struct str_set *set)
{
	int i;

	if (!set)
		return;

	for (i = 0; i < set->cnt; i++)
		free((void *)set->strs[i]);
	free(set->strs);
}

static int parse_str_list(const char *s, struct str_set *set, bool is_glob_pattern)
{
	char *input, *state = NULL, *next, **tmp, **strs = NULL;
	int i, cnt = 0;

	input = strdup(s);
	if (!input)
		return -ENOMEM;

	while ((next = strtok_r(state ? NULL : input, ",", &state))) {
		tmp = realloc(strs, sizeof(*strs) * (cnt + 1));
		if (!tmp)
			goto err;
		strs = tmp;

		if (is_glob_pattern) {
			strs[cnt] = strdup(next);
			if (!strs[cnt])
				goto err;
		} else {
			strs[cnt] = malloc(strlen(next) + 2 + 1);
			if (!strs[cnt])
				goto err;
			sprintf(strs[cnt], "*%s*", next);
		}

		cnt++;
	}

	tmp = realloc(set->strs, sizeof(*strs) * (cnt + set->cnt));
	if (!tmp)
		goto err;
	memcpy(tmp + set->cnt, strs, sizeof(*strs) * cnt);
	set->strs = (const char **)tmp;
	set->cnt += cnt;

	free(input);
	free(strs);
	return 0;
err:
	for (i = 0; i < cnt; i++)
		free(strs[i]);
	free(strs);
	free(input);
	return -ENOMEM;
}

extern int extra_prog_load_log_flags;

static error_t parse_arg(int key, char *arg, struct argp_state *state)
{
	struct test_env *env = state->input;

	switch (key) {
	case ARG_TEST_NUM: {
		char *subtest_str = strchr(arg, '/');

		if (subtest_str) {
			*subtest_str = '\0';
			if (parse_num_list(subtest_str + 1,
					   &env->subtest_selector.num_set,
					   &env->subtest_selector.num_set_len)) {
				fprintf(stderr,
					"Failed to parse subtest numbers.\n");
				return -EINVAL;
			}
		}
		if (parse_num_list(arg, &env->test_selector.num_set,
				   &env->test_selector.num_set_len)) {
			fprintf(stderr, "Failed to parse test numbers.\n");
			return -EINVAL;
		}
		break;
	}
	case ARG_TEST_NAME_GLOB_ALLOWLIST:
	case ARG_TEST_NAME: {
		char *subtest_str = strchr(arg, '/');

		if (subtest_str) {
			*subtest_str = '\0';
			if (parse_str_list(subtest_str + 1,
					   &env->subtest_selector.whitelist,
					   key == ARG_TEST_NAME_GLOB_ALLOWLIST))
				return -ENOMEM;
		}
		if (parse_str_list(arg, &env->test_selector.whitelist,
				   key == ARG_TEST_NAME_GLOB_ALLOWLIST))
			return -ENOMEM;
		break;
	}
	case ARG_TEST_NAME_GLOB_DENYLIST:
	case ARG_TEST_NAME_BLACKLIST: {
		char *subtest_str = strchr(arg, '/');

		if (subtest_str) {
			*subtest_str = '\0';
			if (parse_str_list(subtest_str + 1,
					   &env->subtest_selector.blacklist,
					   key == ARG_TEST_NAME_GLOB_DENYLIST))
				return -ENOMEM;
		}
		if (parse_str_list(arg, &env->test_selector.blacklist,
				   key == ARG_TEST_NAME_GLOB_DENYLIST))
			return -ENOMEM;
		break;
	}
	case ARG_VERIFIER_STATS:
		env->verifier_stats = true;
		break;
	case ARG_VERBOSE:
		env->verbosity = VERBOSE_NORMAL;
		if (arg) {
			if (strcmp(arg, "v") == 0) {
				env->verbosity = VERBOSE_VERY;
				extra_prog_load_log_flags = 1;
			} else if (strcmp(arg, "vv") == 0) {
				env->verbosity = VERBOSE_SUPER;
				extra_prog_load_log_flags = 2;
			} else {
				fprintf(stderr,
					"Unrecognized verbosity setting ('%s'), only -v and -vv are supported\n",
					arg);
				return -EINVAL;
			}
		}

		if (env->verbosity > VERBOSE_NONE) {
			if (setenv("SELFTESTS_VERBOSE", "1", 1) == -1) {
				fprintf(stderr,
					"Unable to setenv SELFTESTS_VERBOSE=1 (errno=%d)",
					errno);
				return -1;
			}
		}

		break;
	case ARG_GET_TEST_CNT:
		env->get_test_cnt = true;
		break;
	case ARG_LIST_TEST_NAMES:
		env->list_test_names = true;
		break;
	case ARGP_KEY_ARG:
		argp_usage(state);
		break;
	case ARGP_KEY_END:
		break;
	default:
		return ARGP_ERR_UNKNOWN;
	}
	return 0;
}

static void stdio_hijack(void)
{
#ifdef __GLIBC__
	env.stdout = stdout;
	env.stderr = stderr;

	if (env.verbosity > VERBOSE_NONE) {
		/* nothing to do, output to stdout by default */
		return;
	}

	/* stdout and stderr -> buffer */
	fflush(stdout);

	stdout = open_memstream(&env.log_buf, &env.log_cnt);
	if (!stdout) {
		stdout = env.stdout;
		perror("open_memstream");
		return;
	}

	stderr = stdout;
#endif
}

static void stdio_restore(void)
{
#ifdef __GLIBC__
	if (stdout == env.stdout)
		return;

	fclose(stdout);
	free(env.log_buf);

	env.log_buf = NULL;
	env.log_cnt = 0;

	stdout = env.stdout;
	stderr = env.stderr;
#endif
}

/*
 * Determine if test_progs is running as a "flavored" test runner and switch
 * into corresponding sub-directory to load correct BPF objects.
 *
 * This is done by looking at executable name. If it contains "-flavor"
 * suffix, then we are running as a flavored test runner.
 */
int cd_flavor_subdir(const char *exec_name)
{
	/* General form of argv[0] passed here is:
	 * some/path/to/test_progs[-flavor], where -flavor part is optional.
	 * First cut out "test_progs[-flavor]" part, then extract "flavor"
	 * part, if it's there.
	 */
	const char *flavor = strrchr(exec_name, '/');

	if (!flavor)
		return 0;
	flavor++;
	flavor = strrchr(flavor, '-');
	if (!flavor)
		return 0;
	flavor++;
	if (env.verbosity > VERBOSE_NONE)
		fprintf(stdout,	"Switching to flavor '%s' subdirectory...\n", flavor);

	return chdir(flavor);
}

#define MAX_BACKTRACE_SZ 128
void crash_handler(int signum)
{
	void *bt[MAX_BACKTRACE_SZ];
	size_t sz;

	sz = backtrace(bt, ARRAY_SIZE(bt));

	if (env.test)
		dump_test_log(env.test, true);
	if (env.stdout)
		stdio_restore();

	fprintf(stderr, "Caught signal #%d!\nStack trace:\n", signum);
	backtrace_symbols_fd(bt, sz, STDERR_FILENO);
}

int main(int argc, char **argv)
{
	static const struct argp argp = {
		.options = opts,
		.parser = parse_arg,
		.doc = argp_program_doc,
	};
	struct sigaction sigact = {
		.sa_handler = crash_handler,
		.sa_flags = SA_RESETHAND,
	};
	int err, i;

	sigaction(SIGSEGV, &sigact, NULL);

	err = argp_parse(&argp, argc, argv, 0, NULL, &env);
	if (err)
		return err;

	err = cd_flavor_subdir(argv[0]);
	if (err)
		return err;

	/* Use libbpf 1.0 API mode */
	libbpf_set_strict_mode(LIBBPF_STRICT_ALL);

	libbpf_set_print(libbpf_print_fn);

	srand(time(NULL));

	env.jit_enabled = is_jit_enabled();
	env.nr_cpus = libbpf_num_possible_cpus();
	if (env.nr_cpus < 0) {
		fprintf(stderr, "Failed to get number of CPUs: %d!\n",
			env.nr_cpus);
		return -1;
	}

	save_netns();
	stdio_hijack();
	env.has_testmod = true;
	if (!env.list_test_names && load_bpf_testmod()) {
		fprintf(env.stderr, "WARNING! Selftests relying on bpf_testmod.ko will be skipped.\n");
		env.has_testmod = false;
	}
	for (i = 0; i < prog_test_cnt; i++) {
		struct prog_test_def *test = &prog_test_defs[i];

		env.test = test;
		test->test_num = i + 1;

		if (!should_run(&env.test_selector,
				test->test_num, test->test_name))
			continue;

		if (env.get_test_cnt) {
			env.succ_cnt++;
			continue;
		}

		if (env.list_test_names) {
			fprintf(env.stdout, "%s\n", test->test_name);
			env.succ_cnt++;
			continue;
		}

		test->run_test();
		/* ensure last sub-test is finalized properly */
		if (test->subtest_name)
			test__end_subtest();

		test->tested = true;

		dump_test_log(test, test->error_cnt);

		fprintf(env.stdout, "#%d %s:%s\n",
			test->test_num, test->test_name,
			test->error_cnt ? "FAIL" : (test->skip_cnt ? "SKIP" : "OK"));

		if (test->error_cnt)
			env.fail_cnt++;
		else
			env.succ_cnt++;
		skip_account();

		reset_affinity();
		restore_netns();
		if (test->need_cgroup_cleanup)
			cleanup_cgroup_environment();
	}
	if (!env.list_test_names && env.has_testmod)
		unload_bpf_testmod();
	stdio_restore();

	if (env.get_test_cnt) {
		printf("%d\n", env.succ_cnt);
		goto out;
	}

	if (env.list_test_names)
		goto out;

	fprintf(stdout, "Summary: %d/%d PASSED, %d SKIPPED, %d FAILED\n",
		env.succ_cnt, env.sub_succ_cnt, env.skip_cnt, env.fail_cnt);

out:
	free_str_set(&env.test_selector.blacklist);
	free_str_set(&env.test_selector.whitelist);
	free(env.test_selector.num_set);
	free_str_set(&env.subtest_selector.blacklist);
	free_str_set(&env.subtest_selector.whitelist);
	free(env.subtest_selector.num_set);
	close(env.saved_netns_fd);

	if (env.succ_cnt + env.fail_cnt + env.skip_cnt == 0)
		return EXIT_NO_TEST;

	return env.fail_cnt ? EXIT_FAILURE : EXIT_SUCCESS;
}