summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/bpf/test_loader.c
blob: 524c38e9cde48feb8977bb26555d29df3656c85a (plain)
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
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
#include <linux/capability.h>
#include <stdlib.h>
#include <test_progs.h>
#include <bpf/btf.h>

#include "autoconf_helper.h"
#include "unpriv_helpers.h"
#include "cap_helpers.h"

#define str_has_pfx(str, pfx) \
	(strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0)

#define TEST_LOADER_LOG_BUF_SZ 2097152

#define TEST_TAG_EXPECT_FAILURE "comment:test_expect_failure"
#define TEST_TAG_EXPECT_SUCCESS "comment:test_expect_success"
#define TEST_TAG_EXPECT_MSG_PFX "comment:test_expect_msg="
#define TEST_TAG_EXPECT_FAILURE_UNPRIV "comment:test_expect_failure_unpriv"
#define TEST_TAG_EXPECT_SUCCESS_UNPRIV "comment:test_expect_success_unpriv"
#define TEST_TAG_EXPECT_MSG_PFX_UNPRIV "comment:test_expect_msg_unpriv="
#define TEST_TAG_LOG_LEVEL_PFX "comment:test_log_level="
#define TEST_TAG_PROG_FLAGS_PFX "comment:test_prog_flags="
#define TEST_TAG_DESCRIPTION_PFX "comment:test_description="
#define TEST_TAG_RETVAL_PFX "comment:test_retval="
#define TEST_TAG_RETVAL_PFX_UNPRIV "comment:test_retval_unpriv="
#define TEST_TAG_AUXILIARY "comment:test_auxiliary"
#define TEST_TAG_AUXILIARY_UNPRIV "comment:test_auxiliary_unpriv"
#define TEST_BTF_PATH "comment:test_btf_path="

/* Warning: duplicated in bpf_misc.h */
#define POINTER_VALUE	0xcafe4all
#define TEST_DATA_LEN	64

#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
#define EFFICIENT_UNALIGNED_ACCESS 1
#else
#define EFFICIENT_UNALIGNED_ACCESS 0
#endif

static int sysctl_unpriv_disabled = -1;

enum mode {
	PRIV = 1,
	UNPRIV = 2
};

struct test_subspec {
	char *name;
	bool expect_failure;
	const char **expect_msgs;
	size_t expect_msg_cnt;
	int retval;
	bool execute;
};

struct test_spec {
	const char *prog_name;
	struct test_subspec priv;
	struct test_subspec unpriv;
	const char *btf_custom_path;
	int log_level;
	int prog_flags;
	int mode_mask;
	bool auxiliary;
	bool valid;
};

static int tester_init(struct test_loader *tester)
{
	if (!tester->log_buf) {
		tester->log_buf_sz = TEST_LOADER_LOG_BUF_SZ;
		tester->log_buf = calloc(tester->log_buf_sz, 1);
		if (!ASSERT_OK_PTR(tester->log_buf, "tester_log_buf"))
			return -ENOMEM;
	}

	return 0;
}

void test_loader_fini(struct test_loader *tester)
{
	if (!tester)
		return;

	free(tester->log_buf);
}

static void free_test_spec(struct test_spec *spec)
{
	free(spec->priv.name);
	free(spec->unpriv.name);
	free(spec->priv.expect_msgs);
	free(spec->unpriv.expect_msgs);

	spec->priv.name = NULL;
	spec->unpriv.name = NULL;
	spec->priv.expect_msgs = NULL;
	spec->unpriv.expect_msgs = NULL;
}

static int push_msg(const char *msg, struct test_subspec *subspec)
{
	void *tmp;

	tmp = realloc(subspec->expect_msgs, (1 + subspec->expect_msg_cnt) * sizeof(void *));
	if (!tmp) {
		ASSERT_FAIL("failed to realloc memory for messages\n");
		return -ENOMEM;
	}
	subspec->expect_msgs = tmp;
	subspec->expect_msgs[subspec->expect_msg_cnt++] = msg;

	return 0;
}

static int parse_int(const char *str, int *val, const char *name)
{
	char *end;
	long tmp;

	errno = 0;
	if (str_has_pfx(str, "0x"))
		tmp = strtol(str + 2, &end, 16);
	else
		tmp = strtol(str, &end, 10);
	if (errno || end[0] != '\0') {
		PRINT_FAIL("failed to parse %s from '%s'\n", name, str);
		return -EINVAL;
	}
	*val = tmp;
	return 0;
}

static int parse_retval(const char *str, int *val, const char *name)
{
	struct {
		char *name;
		int val;
	} named_values[] = {
		{ "INT_MIN"      , INT_MIN },
		{ "POINTER_VALUE", POINTER_VALUE },
		{ "TEST_DATA_LEN", TEST_DATA_LEN },
	};
	int i;

	for (i = 0; i < ARRAY_SIZE(named_values); ++i) {
		if (strcmp(str, named_values[i].name) != 0)
			continue;
		*val = named_values[i].val;
		return 0;
	}

	return parse_int(str, val, name);
}

static void update_flags(int *flags, int flag, bool clear)
{
	if (clear)
		*flags &= ~flag;
	else
		*flags |= flag;
}

/* Uses btf_decl_tag attributes to describe the expected test
 * behavior, see bpf_misc.h for detailed description of each attribute
 * and attribute combinations.
 */
static int parse_test_spec(struct test_loader *tester,
			   struct bpf_object *obj,
			   struct bpf_program *prog,
			   struct test_spec *spec)
{
	const char *description = NULL;
	bool has_unpriv_result = false;
	bool has_unpriv_retval = false;
	int func_id, i, err = 0;
	struct btf *btf;

	memset(spec, 0, sizeof(*spec));

	spec->prog_name = bpf_program__name(prog);
	spec->prog_flags = testing_prog_flags();

	btf = bpf_object__btf(obj);
	if (!btf) {
		ASSERT_FAIL("BPF object has no BTF");
		return -EINVAL;
	}

	func_id = btf__find_by_name_kind(btf, spec->prog_name, BTF_KIND_FUNC);
	if (func_id < 0) {
		ASSERT_FAIL("failed to find FUNC BTF type for '%s'", spec->prog_name);
		return -EINVAL;
	}

	for (i = 1; i < btf__type_cnt(btf); i++) {
		const char *s, *val, *msg;
		const struct btf_type *t;
		bool clear;
		int flags;

		t = btf__type_by_id(btf, i);
		if (!btf_is_decl_tag(t))
			continue;

		if (t->type != func_id || btf_decl_tag(t)->component_idx != -1)
			continue;

		s = btf__str_by_offset(btf, t->name_off);
		if (str_has_pfx(s, TEST_TAG_DESCRIPTION_PFX)) {
			description = s + sizeof(TEST_TAG_DESCRIPTION_PFX) - 1;
		} else if (strcmp(s, TEST_TAG_EXPECT_FAILURE) == 0) {
			spec->priv.expect_failure = true;
			spec->mode_mask |= PRIV;
		} else if (strcmp(s, TEST_TAG_EXPECT_SUCCESS) == 0) {
			spec->priv.expect_failure = false;
			spec->mode_mask |= PRIV;
		} else if (strcmp(s, TEST_TAG_EXPECT_FAILURE_UNPRIV) == 0) {
			spec->unpriv.expect_failure = true;
			spec->mode_mask |= UNPRIV;
			has_unpriv_result = true;
		} else if (strcmp(s, TEST_TAG_EXPECT_SUCCESS_UNPRIV) == 0) {
			spec->unpriv.expect_failure = false;
			spec->mode_mask |= UNPRIV;
			has_unpriv_result = true;
		} else if (strcmp(s, TEST_TAG_AUXILIARY) == 0) {
			spec->auxiliary = true;
			spec->mode_mask |= PRIV;
		} else if (strcmp(s, TEST_TAG_AUXILIARY_UNPRIV) == 0) {
			spec->auxiliary = true;
			spec->mode_mask |= UNPRIV;
		} else if (str_has_pfx(s, TEST_TAG_EXPECT_MSG_PFX)) {
			msg = s + sizeof(TEST_TAG_EXPECT_MSG_PFX) - 1;
			err = push_msg(msg, &spec->priv);
			if (err)
				goto cleanup;
			spec->mode_mask |= PRIV;
		} else if (str_has_pfx(s, TEST_TAG_EXPECT_MSG_PFX_UNPRIV)) {
			msg = s + sizeof(TEST_TAG_EXPECT_MSG_PFX_UNPRIV) - 1;
			err = push_msg(msg, &spec->unpriv);
			if (err)
				goto cleanup;
			spec->mode_mask |= UNPRIV;
		} else if (str_has_pfx(s, TEST_TAG_RETVAL_PFX)) {
			val = s + sizeof(TEST_TAG_RETVAL_PFX) - 1;
			err = parse_retval(val, &spec->priv.retval, "__retval");
			if (err)
				goto cleanup;
			spec->priv.execute = true;
			spec->mode_mask |= PRIV;
		} else if (str_has_pfx(s, TEST_TAG_RETVAL_PFX_UNPRIV)) {
			val = s + sizeof(TEST_TAG_RETVAL_PFX_UNPRIV) - 1;
			err = parse_retval(val, &spec->unpriv.retval, "__retval_unpriv");
			if (err)
				goto cleanup;
			spec->mode_mask |= UNPRIV;
			spec->unpriv.execute = true;
			has_unpriv_retval = true;
		} else if (str_has_pfx(s, TEST_TAG_LOG_LEVEL_PFX)) {
			val = s + sizeof(TEST_TAG_LOG_LEVEL_PFX) - 1;
			err = parse_int(val, &spec->log_level, "test log level");
			if (err)
				goto cleanup;
		} else if (str_has_pfx(s, TEST_TAG_PROG_FLAGS_PFX)) {
			val = s + sizeof(TEST_TAG_PROG_FLAGS_PFX) - 1;

			clear = val[0] == '!';
			if (clear)
				val++;

			if (strcmp(val, "BPF_F_STRICT_ALIGNMENT") == 0) {
				update_flags(&spec->prog_flags, BPF_F_STRICT_ALIGNMENT, clear);
			} else if (strcmp(val, "BPF_F_ANY_ALIGNMENT") == 0) {
				update_flags(&spec->prog_flags, BPF_F_ANY_ALIGNMENT, clear);
			} else if (strcmp(val, "BPF_F_TEST_RND_HI32") == 0) {
				update_flags(&spec->prog_flags, BPF_F_TEST_RND_HI32, clear);
			} else if (strcmp(val, "BPF_F_TEST_STATE_FREQ") == 0) {
				update_flags(&spec->prog_flags, BPF_F_TEST_STATE_FREQ, clear);
			} else if (strcmp(val, "BPF_F_SLEEPABLE") == 0) {
				update_flags(&spec->prog_flags, BPF_F_SLEEPABLE, clear);
			} else if (strcmp(val, "BPF_F_XDP_HAS_FRAGS") == 0) {
				update_flags(&spec->prog_flags, BPF_F_XDP_HAS_FRAGS, clear);
			} else if (strcmp(val, "BPF_F_TEST_REG_INVARIANTS") == 0) {
				update_flags(&spec->prog_flags, BPF_F_TEST_REG_INVARIANTS, clear);
			} else /* assume numeric value */ {
				err = parse_int(val, &flags, "test prog flags");
				if (err)
					goto cleanup;
				update_flags(&spec->prog_flags, flags, clear);
			}
		} else if (str_has_pfx(s, TEST_BTF_PATH)) {
			spec->btf_custom_path = s + sizeof(TEST_BTF_PATH) - 1;
		}
	}

	if (spec->mode_mask == 0)
		spec->mode_mask = PRIV;

	if (!description)
		description = spec->prog_name;

	if (spec->mode_mask & PRIV) {
		spec->priv.name = strdup(description);
		if (!spec->priv.name) {
			PRINT_FAIL("failed to allocate memory for priv.name\n");
			err = -ENOMEM;
			goto cleanup;
		}
	}

	if (spec->mode_mask & UNPRIV) {
		int descr_len = strlen(description);
		const char *suffix = " @unpriv";
		char *name;

		name = malloc(descr_len + strlen(suffix) + 1);
		if (!name) {
			PRINT_FAIL("failed to allocate memory for unpriv.name\n");
			err = -ENOMEM;
			goto cleanup;
		}

		strcpy(name, description);
		strcpy(&name[descr_len], suffix);
		spec->unpriv.name = name;
	}

	if (spec->mode_mask & (PRIV | UNPRIV)) {
		if (!has_unpriv_result)
			spec->unpriv.expect_failure = spec->priv.expect_failure;

		if (!has_unpriv_retval) {
			spec->unpriv.retval = spec->priv.retval;
			spec->unpriv.execute = spec->priv.execute;
		}

		if (!spec->unpriv.expect_msgs) {
			size_t sz = spec->priv.expect_msg_cnt * sizeof(void *);

			spec->unpriv.expect_msgs = malloc(sz);
			if (!spec->unpriv.expect_msgs) {
				PRINT_FAIL("failed to allocate memory for unpriv.expect_msgs\n");
				err = -ENOMEM;
				goto cleanup;
			}
			memcpy(spec->unpriv.expect_msgs, spec->priv.expect_msgs, sz);
			spec->unpriv.expect_msg_cnt = spec->priv.expect_msg_cnt;
		}
	}

	spec->valid = true;

	return 0;

cleanup:
	free_test_spec(spec);
	return err;
}

static void prepare_case(struct test_loader *tester,
			 struct test_spec *spec,
			 struct bpf_object *obj,
			 struct bpf_program *prog)
{
	int min_log_level = 0, prog_flags;

	if (env.verbosity > VERBOSE_NONE)
		min_log_level = 1;
	if (env.verbosity > VERBOSE_VERY)
		min_log_level = 2;

	bpf_program__set_log_buf(prog, tester->log_buf, tester->log_buf_sz);

	/* Make sure we set at least minimal log level, unless test requires
	 * even higher level already. Make sure to preserve independent log
	 * level 4 (verifier stats), though.
	 */
	if ((spec->log_level & 3) < min_log_level)
		bpf_program__set_log_level(prog, (spec->log_level & 4) | min_log_level);
	else
		bpf_program__set_log_level(prog, spec->log_level);

	prog_flags = bpf_program__flags(prog);
	bpf_program__set_flags(prog, prog_flags | spec->prog_flags);

	tester->log_buf[0] = '\0';
	tester->next_match_pos = 0;
}

static void emit_verifier_log(const char *log_buf, bool force)
{
	if (!force && env.verbosity == VERBOSE_NONE)
		return;
	fprintf(stdout, "VERIFIER LOG:\n=============\n%s=============\n", log_buf);
}

static void validate_case(struct test_loader *tester,
			  struct test_subspec *subspec,
			  struct bpf_object *obj,
			  struct bpf_program *prog,
			  int load_err)
{
	int i, j;

	for (i = 0; i < subspec->expect_msg_cnt; i++) {
		char *match;
		const char *expect_msg;

		expect_msg = subspec->expect_msgs[i];

		match = strstr(tester->log_buf + tester->next_match_pos, expect_msg);
		if (!ASSERT_OK_PTR(match, "expect_msg")) {
			/* if we are in verbose mode, we've already emitted log */
			if (env.verbosity == VERBOSE_NONE)
				emit_verifier_log(tester->log_buf, true /*force*/);
			for (j = 0; j < i; j++)
				fprintf(stderr,
					"MATCHED  MSG: '%s'\n", subspec->expect_msgs[j]);
			fprintf(stderr, "EXPECTED MSG: '%s'\n", expect_msg);
			return;
		}

		tester->next_match_pos = match - tester->log_buf + strlen(expect_msg);
	}
}

struct cap_state {
	__u64 old_caps;
	bool initialized;
};

static int drop_capabilities(struct cap_state *caps)
{
	const __u64 caps_to_drop = (1ULL << CAP_SYS_ADMIN | 1ULL << CAP_NET_ADMIN |
				    1ULL << CAP_PERFMON   | 1ULL << CAP_BPF);
	int err;

	err = cap_disable_effective(caps_to_drop, &caps->old_caps);
	if (err) {
		PRINT_FAIL("failed to drop capabilities: %i, %s\n", err, strerror(err));
		return err;
	}

	caps->initialized = true;
	return 0;
}

static int restore_capabilities(struct cap_state *caps)
{
	int err;

	if (!caps->initialized)
		return 0;

	err = cap_enable_effective(caps->old_caps, NULL);
	if (err)
		PRINT_FAIL("failed to restore capabilities: %i, %s\n", err, strerror(err));
	caps->initialized = false;
	return err;
}

static bool can_execute_unpriv(struct test_loader *tester, struct test_spec *spec)
{
	if (sysctl_unpriv_disabled < 0)
		sysctl_unpriv_disabled = get_unpriv_disabled() ? 1 : 0;
	if (sysctl_unpriv_disabled)
		return false;
	if ((spec->prog_flags & BPF_F_ANY_ALIGNMENT) && !EFFICIENT_UNALIGNED_ACCESS)
		return false;
	return true;
}

static bool is_unpriv_capable_map(struct bpf_map *map)
{
	enum bpf_map_type type;
	__u32 flags;

	type = bpf_map__type(map);

	switch (type) {
	case BPF_MAP_TYPE_HASH:
	case BPF_MAP_TYPE_PERCPU_HASH:
	case BPF_MAP_TYPE_HASH_OF_MAPS:
		flags = bpf_map__map_flags(map);
		return !(flags & BPF_F_ZERO_SEED);
	case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
	case BPF_MAP_TYPE_ARRAY:
	case BPF_MAP_TYPE_RINGBUF:
	case BPF_MAP_TYPE_PROG_ARRAY:
	case BPF_MAP_TYPE_CGROUP_ARRAY:
	case BPF_MAP_TYPE_PERCPU_ARRAY:
	case BPF_MAP_TYPE_USER_RINGBUF:
	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
	case BPF_MAP_TYPE_CGROUP_STORAGE:
	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
		return true;
	default:
		return false;
	}
}

static int do_prog_test_run(int fd_prog, int *retval, bool empty_opts)
{
	__u8 tmp_out[TEST_DATA_LEN << 2] = {};
	__u8 tmp_in[TEST_DATA_LEN] = {};
	int err, saved_errno;
	LIBBPF_OPTS(bpf_test_run_opts, topts,
		.data_in = tmp_in,
		.data_size_in = sizeof(tmp_in),
		.data_out = tmp_out,
		.data_size_out = sizeof(tmp_out),
		.repeat = 1,
	);

	if (empty_opts) {
		memset(&topts, 0, sizeof(struct bpf_test_run_opts));
		topts.sz = sizeof(struct bpf_test_run_opts);
	}
	err = bpf_prog_test_run_opts(fd_prog, &topts);
	saved_errno = errno;

	if (err) {
		PRINT_FAIL("FAIL: Unexpected bpf_prog_test_run error: %d (%s) ",
			   saved_errno, strerror(saved_errno));
		return err;
	}

	ASSERT_OK(0, "bpf_prog_test_run");
	*retval = topts.retval;

	return 0;
}

static bool should_do_test_run(struct test_spec *spec, struct test_subspec *subspec)
{
	if (!subspec->execute)
		return false;

	if (subspec->expect_failure)
		return false;

	if ((spec->prog_flags & BPF_F_ANY_ALIGNMENT) && !EFFICIENT_UNALIGNED_ACCESS) {
		if (env.verbosity != VERBOSE_NONE)
			printf("alignment prevents execution\n");
		return false;
	}

	return true;
}

/* this function is forced noinline and has short generic name to look better
 * in test_progs output (in case of a failure)
 */
static noinline
void run_subtest(struct test_loader *tester,
		 struct bpf_object_open_opts *open_opts,
		 const void *obj_bytes,
		 size_t obj_byte_cnt,
		 struct test_spec *specs,
		 struct test_spec *spec,
		 bool unpriv)
{
	struct test_subspec *subspec = unpriv ? &spec->unpriv : &spec->priv;
	struct bpf_program *tprog = NULL, *tprog_iter;
	struct test_spec *spec_iter;
	struct cap_state caps = {};
	struct bpf_object *tobj;
	struct bpf_map *map;
	int retval, err, i;
	bool should_load;

	if (!test__start_subtest(subspec->name))
		return;

	if (unpriv) {
		if (!can_execute_unpriv(tester, spec)) {
			test__skip();
			test__end_subtest();
			return;
		}
		if (drop_capabilities(&caps)) {
			test__end_subtest();
			return;
		}
	}

	/* Implicitly reset to NULL if next test case doesn't specify */
	open_opts->btf_custom_path = spec->btf_custom_path;

	tobj = bpf_object__open_mem(obj_bytes, obj_byte_cnt, open_opts);
	if (!ASSERT_OK_PTR(tobj, "obj_open_mem")) /* shouldn't happen */
		goto subtest_cleanup;

	i = 0;
	bpf_object__for_each_program(tprog_iter, tobj) {
		spec_iter = &specs[i++];
		should_load = false;

		if (spec_iter->valid) {
			if (strcmp(bpf_program__name(tprog_iter), spec->prog_name) == 0) {
				tprog = tprog_iter;
				should_load = true;
			}

			if (spec_iter->auxiliary &&
			    spec_iter->mode_mask & (unpriv ? UNPRIV : PRIV))
				should_load = true;
		}

		bpf_program__set_autoload(tprog_iter, should_load);
	}

	prepare_case(tester, spec, tobj, tprog);

	/* By default bpf_object__load() automatically creates all
	 * maps declared in the skeleton. Some map types are only
	 * allowed in priv mode. Disable autoload for such maps in
	 * unpriv mode.
	 */
	bpf_object__for_each_map(map, tobj)
		bpf_map__set_autocreate(map, !unpriv || is_unpriv_capable_map(map));

	err = bpf_object__load(tobj);
	if (subspec->expect_failure) {
		if (!ASSERT_ERR(err, "unexpected_load_success")) {
			emit_verifier_log(tester->log_buf, false /*force*/);
			goto tobj_cleanup;
		}
	} else {
		if (!ASSERT_OK(err, "unexpected_load_failure")) {
			emit_verifier_log(tester->log_buf, true /*force*/);
			goto tobj_cleanup;
		}
	}

	emit_verifier_log(tester->log_buf, false /*force*/);
	validate_case(tester, subspec, tobj, tprog, err);

	if (should_do_test_run(spec, subspec)) {
		/* For some reason test_verifier executes programs
		 * with all capabilities restored. Do the same here.
		 */
		if (restore_capabilities(&caps))
			goto tobj_cleanup;

		if (tester->pre_execution_cb) {
			err = tester->pre_execution_cb(tobj);
			if (err) {
				PRINT_FAIL("pre_execution_cb failed: %d\n", err);
				goto tobj_cleanup;
			}
		}

		do_prog_test_run(bpf_program__fd(tprog), &retval,
				 bpf_program__type(tprog) == BPF_PROG_TYPE_SYSCALL ? true : false);
		if (retval != subspec->retval && subspec->retval != POINTER_VALUE) {
			PRINT_FAIL("Unexpected retval: %d != %d\n", retval, subspec->retval);
			goto tobj_cleanup;
		}
	}

tobj_cleanup:
	bpf_object__close(tobj);
subtest_cleanup:
	test__end_subtest();
	restore_capabilities(&caps);
}

static void process_subtest(struct test_loader *tester,
			    const char *skel_name,
			    skel_elf_bytes_fn elf_bytes_factory)
{
	LIBBPF_OPTS(bpf_object_open_opts, open_opts, .object_name = skel_name);
	struct test_spec *specs = NULL;
	struct bpf_object *obj = NULL;
	struct bpf_program *prog;
	const void *obj_bytes;
	int err, i, nr_progs;
	size_t obj_byte_cnt;

	if (tester_init(tester) < 0)
		return; /* failed to initialize tester */

	obj_bytes = elf_bytes_factory(&obj_byte_cnt);
	obj = bpf_object__open_mem(obj_bytes, obj_byte_cnt, &open_opts);
	if (!ASSERT_OK_PTR(obj, "obj_open_mem"))
		return;

	nr_progs = 0;
	bpf_object__for_each_program(prog, obj)
		++nr_progs;

	specs = calloc(nr_progs, sizeof(struct test_spec));
	if (!ASSERT_OK_PTR(specs, "specs_alloc"))
		return;

	i = 0;
	bpf_object__for_each_program(prog, obj) {
		/* ignore tests for which  we can't derive test specification */
		err = parse_test_spec(tester, obj, prog, &specs[i++]);
		if (err)
			PRINT_FAIL("Can't parse test spec for program '%s'\n",
				   bpf_program__name(prog));
	}

	i = 0;
	bpf_object__for_each_program(prog, obj) {
		struct test_spec *spec = &specs[i++];

		if (!spec->valid || spec->auxiliary)
			continue;

		if (spec->mode_mask & PRIV)
			run_subtest(tester, &open_opts, obj_bytes, obj_byte_cnt,
				    specs, spec, false);
		if (spec->mode_mask & UNPRIV)
			run_subtest(tester, &open_opts, obj_bytes, obj_byte_cnt,
				    specs, spec, true);

	}

	for (i = 0; i < nr_progs; ++i)
		free_test_spec(&specs[i]);
	free(specs);
	bpf_object__close(obj);
}

void test_loader__run_subtests(struct test_loader *tester,
			       const char *skel_name,
			       skel_elf_bytes_fn elf_bytes_factory)
{
	/* see comment in run_subtest() for why we do this function nesting */
	process_subtest(tester, skel_name, elf_bytes_factory);
}