1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
3 #include <linux/capability.h>
4 #include <stdlib.h>
5 #include <test_progs.h>
6 #include <bpf/btf.h>
7 
8 #include "autoconf_helper.h"
9 #include "unpriv_helpers.h"
10 #include "cap_helpers.h"
11 
12 #define str_has_pfx(str, pfx) \
13 	(strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0)
14 
15 #define TEST_LOADER_LOG_BUF_SZ 1048576
16 
17 #define TEST_TAG_EXPECT_FAILURE "comment:test_expect_failure"
18 #define TEST_TAG_EXPECT_SUCCESS "comment:test_expect_success"
19 #define TEST_TAG_EXPECT_MSG_PFX "comment:test_expect_msg="
20 #define TEST_TAG_EXPECT_FAILURE_UNPRIV "comment:test_expect_failure_unpriv"
21 #define TEST_TAG_EXPECT_SUCCESS_UNPRIV "comment:test_expect_success_unpriv"
22 #define TEST_TAG_EXPECT_MSG_PFX_UNPRIV "comment:test_expect_msg_unpriv="
23 #define TEST_TAG_LOG_LEVEL_PFX "comment:test_log_level="
24 #define TEST_TAG_PROG_FLAGS_PFX "comment:test_prog_flags="
25 #define TEST_TAG_DESCRIPTION_PFX "comment:test_description="
26 #define TEST_TAG_RETVAL_PFX "comment:test_retval="
27 #define TEST_TAG_RETVAL_PFX_UNPRIV "comment:test_retval_unpriv="
28 #define TEST_TAG_AUXILIARY "comment:test_auxiliary"
29 #define TEST_TAG_AUXILIARY_UNPRIV "comment:test_auxiliary_unpriv"
30 
31 /* Warning: duplicated in bpf_misc.h */
32 #define POINTER_VALUE	0xcafe4all
33 #define TEST_DATA_LEN	64
34 
35 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
36 #define EFFICIENT_UNALIGNED_ACCESS 1
37 #else
38 #define EFFICIENT_UNALIGNED_ACCESS 0
39 #endif
40 
41 static int sysctl_unpriv_disabled = -1;
42 
43 enum mode {
44 	PRIV = 1,
45 	UNPRIV = 2
46 };
47 
48 struct test_subspec {
49 	char *name;
50 	bool expect_failure;
51 	const char **expect_msgs;
52 	size_t expect_msg_cnt;
53 	int retval;
54 	bool execute;
55 };
56 
57 struct test_spec {
58 	const char *prog_name;
59 	struct test_subspec priv;
60 	struct test_subspec unpriv;
61 	int log_level;
62 	int prog_flags;
63 	int mode_mask;
64 	bool auxiliary;
65 	bool valid;
66 };
67 
68 static int tester_init(struct test_loader *tester)
69 {
70 	if (!tester->log_buf) {
71 		tester->log_buf_sz = TEST_LOADER_LOG_BUF_SZ;
72 		tester->log_buf = malloc(tester->log_buf_sz);
73 		if (!ASSERT_OK_PTR(tester->log_buf, "tester_log_buf"))
74 			return -ENOMEM;
75 	}
76 
77 	return 0;
78 }
79 
80 void test_loader_fini(struct test_loader *tester)
81 {
82 	if (!tester)
83 		return;
84 
85 	free(tester->log_buf);
86 }
87 
88 static void free_test_spec(struct test_spec *spec)
89 {
90 	free(spec->priv.name);
91 	free(spec->unpriv.name);
92 	free(spec->priv.expect_msgs);
93 	free(spec->unpriv.expect_msgs);
94 
95 	spec->priv.name = NULL;
96 	spec->unpriv.name = NULL;
97 	spec->priv.expect_msgs = NULL;
98 	spec->unpriv.expect_msgs = NULL;
99 }
100 
101 static int push_msg(const char *msg, struct test_subspec *subspec)
102 {
103 	void *tmp;
104 
105 	tmp = realloc(subspec->expect_msgs, (1 + subspec->expect_msg_cnt) * sizeof(void *));
106 	if (!tmp) {
107 		ASSERT_FAIL("failed to realloc memory for messages\n");
108 		return -ENOMEM;
109 	}
110 	subspec->expect_msgs = tmp;
111 	subspec->expect_msgs[subspec->expect_msg_cnt++] = msg;
112 
113 	return 0;
114 }
115 
116 static int parse_int(const char *str, int *val, const char *name)
117 {
118 	char *end;
119 	long tmp;
120 
121 	errno = 0;
122 	if (str_has_pfx(str, "0x"))
123 		tmp = strtol(str + 2, &end, 16);
124 	else
125 		tmp = strtol(str, &end, 10);
126 	if (errno || end[0] != '\0') {
127 		PRINT_FAIL("failed to parse %s from '%s'\n", name, str);
128 		return -EINVAL;
129 	}
130 	*val = tmp;
131 	return 0;
132 }
133 
134 static int parse_retval(const char *str, int *val, const char *name)
135 {
136 	struct {
137 		char *name;
138 		int val;
139 	} named_values[] = {
140 		{ "INT_MIN"      , INT_MIN },
141 		{ "POINTER_VALUE", POINTER_VALUE },
142 		{ "TEST_DATA_LEN", TEST_DATA_LEN },
143 	};
144 	int i;
145 
146 	for (i = 0; i < ARRAY_SIZE(named_values); ++i) {
147 		if (strcmp(str, named_values[i].name) != 0)
148 			continue;
149 		*val = named_values[i].val;
150 		return 0;
151 	}
152 
153 	return parse_int(str, val, name);
154 }
155 
156 /* Uses btf_decl_tag attributes to describe the expected test
157  * behavior, see bpf_misc.h for detailed description of each attribute
158  * and attribute combinations.
159  */
160 static int parse_test_spec(struct test_loader *tester,
161 			   struct bpf_object *obj,
162 			   struct bpf_program *prog,
163 			   struct test_spec *spec)
164 {
165 	const char *description = NULL;
166 	bool has_unpriv_result = false;
167 	bool has_unpriv_retval = false;
168 	int func_id, i, err = 0;
169 	struct btf *btf;
170 
171 	memset(spec, 0, sizeof(*spec));
172 
173 	spec->prog_name = bpf_program__name(prog);
174 
175 	btf = bpf_object__btf(obj);
176 	if (!btf) {
177 		ASSERT_FAIL("BPF object has no BTF");
178 		return -EINVAL;
179 	}
180 
181 	func_id = btf__find_by_name_kind(btf, spec->prog_name, BTF_KIND_FUNC);
182 	if (func_id < 0) {
183 		ASSERT_FAIL("failed to find FUNC BTF type for '%s'", spec->prog_name);
184 		return -EINVAL;
185 	}
186 
187 	for (i = 1; i < btf__type_cnt(btf); i++) {
188 		const char *s, *val, *msg;
189 		const struct btf_type *t;
190 		int tmp;
191 
192 		t = btf__type_by_id(btf, i);
193 		if (!btf_is_decl_tag(t))
194 			continue;
195 
196 		if (t->type != func_id || btf_decl_tag(t)->component_idx != -1)
197 			continue;
198 
199 		s = btf__str_by_offset(btf, t->name_off);
200 		if (str_has_pfx(s, TEST_TAG_DESCRIPTION_PFX)) {
201 			description = s + sizeof(TEST_TAG_DESCRIPTION_PFX) - 1;
202 		} else if (strcmp(s, TEST_TAG_EXPECT_FAILURE) == 0) {
203 			spec->priv.expect_failure = true;
204 			spec->mode_mask |= PRIV;
205 		} else if (strcmp(s, TEST_TAG_EXPECT_SUCCESS) == 0) {
206 			spec->priv.expect_failure = false;
207 			spec->mode_mask |= PRIV;
208 		} else if (strcmp(s, TEST_TAG_EXPECT_FAILURE_UNPRIV) == 0) {
209 			spec->unpriv.expect_failure = true;
210 			spec->mode_mask |= UNPRIV;
211 			has_unpriv_result = true;
212 		} else if (strcmp(s, TEST_TAG_EXPECT_SUCCESS_UNPRIV) == 0) {
213 			spec->unpriv.expect_failure = false;
214 			spec->mode_mask |= UNPRIV;
215 			has_unpriv_result = true;
216 		} else if (strcmp(s, TEST_TAG_AUXILIARY) == 0) {
217 			spec->auxiliary = true;
218 			spec->mode_mask |= PRIV;
219 		} else if (strcmp(s, TEST_TAG_AUXILIARY_UNPRIV) == 0) {
220 			spec->auxiliary = true;
221 			spec->mode_mask |= UNPRIV;
222 		} else if (str_has_pfx(s, TEST_TAG_EXPECT_MSG_PFX)) {
223 			msg = s + sizeof(TEST_TAG_EXPECT_MSG_PFX) - 1;
224 			err = push_msg(msg, &spec->priv);
225 			if (err)
226 				goto cleanup;
227 			spec->mode_mask |= PRIV;
228 		} else if (str_has_pfx(s, TEST_TAG_EXPECT_MSG_PFX_UNPRIV)) {
229 			msg = s + sizeof(TEST_TAG_EXPECT_MSG_PFX_UNPRIV) - 1;
230 			err = push_msg(msg, &spec->unpriv);
231 			if (err)
232 				goto cleanup;
233 			spec->mode_mask |= UNPRIV;
234 		} else if (str_has_pfx(s, TEST_TAG_RETVAL_PFX)) {
235 			val = s + sizeof(TEST_TAG_RETVAL_PFX) - 1;
236 			err = parse_retval(val, &spec->priv.retval, "__retval");
237 			if (err)
238 				goto cleanup;
239 			spec->priv.execute = true;
240 			spec->mode_mask |= PRIV;
241 		} else if (str_has_pfx(s, TEST_TAG_RETVAL_PFX_UNPRIV)) {
242 			val = s + sizeof(TEST_TAG_RETVAL_PFX_UNPRIV) - 1;
243 			err = parse_retval(val, &spec->unpriv.retval, "__retval_unpriv");
244 			if (err)
245 				goto cleanup;
246 			spec->mode_mask |= UNPRIV;
247 			spec->unpriv.execute = true;
248 			has_unpriv_retval = true;
249 		} else if (str_has_pfx(s, TEST_TAG_LOG_LEVEL_PFX)) {
250 			val = s + sizeof(TEST_TAG_LOG_LEVEL_PFX) - 1;
251 			err = parse_int(val, &spec->log_level, "test log level");
252 			if (err)
253 				goto cleanup;
254 		} else if (str_has_pfx(s, TEST_TAG_PROG_FLAGS_PFX)) {
255 			val = s + sizeof(TEST_TAG_PROG_FLAGS_PFX) - 1;
256 			if (strcmp(val, "BPF_F_STRICT_ALIGNMENT") == 0) {
257 				spec->prog_flags |= BPF_F_STRICT_ALIGNMENT;
258 			} else if (strcmp(val, "BPF_F_ANY_ALIGNMENT") == 0) {
259 				spec->prog_flags |= BPF_F_ANY_ALIGNMENT;
260 			} else if (strcmp(val, "BPF_F_TEST_RND_HI32") == 0) {
261 				spec->prog_flags |= BPF_F_TEST_RND_HI32;
262 			} else if (strcmp(val, "BPF_F_TEST_STATE_FREQ") == 0) {
263 				spec->prog_flags |= BPF_F_TEST_STATE_FREQ;
264 			} else if (strcmp(val, "BPF_F_SLEEPABLE") == 0) {
265 				spec->prog_flags |= BPF_F_SLEEPABLE;
266 			} else if (strcmp(val, "BPF_F_XDP_HAS_FRAGS") == 0) {
267 				spec->prog_flags |= BPF_F_XDP_HAS_FRAGS;
268 			} else /* assume numeric value */ {
269 				err = parse_int(val, &tmp, "test prog flags");
270 				if (err)
271 					goto cleanup;
272 				spec->prog_flags |= tmp;
273 			}
274 		}
275 	}
276 
277 	if (spec->mode_mask == 0)
278 		spec->mode_mask = PRIV;
279 
280 	if (!description)
281 		description = spec->prog_name;
282 
283 	if (spec->mode_mask & PRIV) {
284 		spec->priv.name = strdup(description);
285 		if (!spec->priv.name) {
286 			PRINT_FAIL("failed to allocate memory for priv.name\n");
287 			err = -ENOMEM;
288 			goto cleanup;
289 		}
290 	}
291 
292 	if (spec->mode_mask & UNPRIV) {
293 		int descr_len = strlen(description);
294 		const char *suffix = " @unpriv";
295 		char *name;
296 
297 		name = malloc(descr_len + strlen(suffix) + 1);
298 		if (!name) {
299 			PRINT_FAIL("failed to allocate memory for unpriv.name\n");
300 			err = -ENOMEM;
301 			goto cleanup;
302 		}
303 
304 		strcpy(name, description);
305 		strcpy(&name[descr_len], suffix);
306 		spec->unpriv.name = name;
307 	}
308 
309 	if (spec->mode_mask & (PRIV | UNPRIV)) {
310 		if (!has_unpriv_result)
311 			spec->unpriv.expect_failure = spec->priv.expect_failure;
312 
313 		if (!has_unpriv_retval) {
314 			spec->unpriv.retval = spec->priv.retval;
315 			spec->unpriv.execute = spec->priv.execute;
316 		}
317 
318 		if (!spec->unpriv.expect_msgs) {
319 			size_t sz = spec->priv.expect_msg_cnt * sizeof(void *);
320 
321 			spec->unpriv.expect_msgs = malloc(sz);
322 			if (!spec->unpriv.expect_msgs) {
323 				PRINT_FAIL("failed to allocate memory for unpriv.expect_msgs\n");
324 				err = -ENOMEM;
325 				goto cleanup;
326 			}
327 			memcpy(spec->unpriv.expect_msgs, spec->priv.expect_msgs, sz);
328 			spec->unpriv.expect_msg_cnt = spec->priv.expect_msg_cnt;
329 		}
330 	}
331 
332 	spec->valid = true;
333 
334 	return 0;
335 
336 cleanup:
337 	free_test_spec(spec);
338 	return err;
339 }
340 
341 static void prepare_case(struct test_loader *tester,
342 			 struct test_spec *spec,
343 			 struct bpf_object *obj,
344 			 struct bpf_program *prog)
345 {
346 	int min_log_level = 0, prog_flags;
347 
348 	if (env.verbosity > VERBOSE_NONE)
349 		min_log_level = 1;
350 	if (env.verbosity > VERBOSE_VERY)
351 		min_log_level = 2;
352 
353 	bpf_program__set_log_buf(prog, tester->log_buf, tester->log_buf_sz);
354 
355 	/* Make sure we set at least minimal log level, unless test requires
356 	 * even higher level already. Make sure to preserve independent log
357 	 * level 4 (verifier stats), though.
358 	 */
359 	if ((spec->log_level & 3) < min_log_level)
360 		bpf_program__set_log_level(prog, (spec->log_level & 4) | min_log_level);
361 	else
362 		bpf_program__set_log_level(prog, spec->log_level);
363 
364 	prog_flags = bpf_program__flags(prog);
365 	bpf_program__set_flags(prog, prog_flags | spec->prog_flags);
366 
367 	tester->log_buf[0] = '\0';
368 	tester->next_match_pos = 0;
369 }
370 
371 static void emit_verifier_log(const char *log_buf, bool force)
372 {
373 	if (!force && env.verbosity == VERBOSE_NONE)
374 		return;
375 	fprintf(stdout, "VERIFIER LOG:\n=============\n%s=============\n", log_buf);
376 }
377 
378 static void validate_case(struct test_loader *tester,
379 			  struct test_subspec *subspec,
380 			  struct bpf_object *obj,
381 			  struct bpf_program *prog,
382 			  int load_err)
383 {
384 	int i, j;
385 
386 	for (i = 0; i < subspec->expect_msg_cnt; i++) {
387 		char *match;
388 		const char *expect_msg;
389 
390 		expect_msg = subspec->expect_msgs[i];
391 
392 		match = strstr(tester->log_buf + tester->next_match_pos, expect_msg);
393 		if (!ASSERT_OK_PTR(match, "expect_msg")) {
394 			/* if we are in verbose mode, we've already emitted log */
395 			if (env.verbosity == VERBOSE_NONE)
396 				emit_verifier_log(tester->log_buf, true /*force*/);
397 			for (j = 0; j < i; j++)
398 				fprintf(stderr,
399 					"MATCHED  MSG: '%s'\n", subspec->expect_msgs[j]);
400 			fprintf(stderr, "EXPECTED MSG: '%s'\n", expect_msg);
401 			return;
402 		}
403 
404 		tester->next_match_pos = match - tester->log_buf + strlen(expect_msg);
405 	}
406 }
407 
408 struct cap_state {
409 	__u64 old_caps;
410 	bool initialized;
411 };
412 
413 static int drop_capabilities(struct cap_state *caps)
414 {
415 	const __u64 caps_to_drop = (1ULL << CAP_SYS_ADMIN | 1ULL << CAP_NET_ADMIN |
416 				    1ULL << CAP_PERFMON   | 1ULL << CAP_BPF);
417 	int err;
418 
419 	err = cap_disable_effective(caps_to_drop, &caps->old_caps);
420 	if (err) {
421 		PRINT_FAIL("failed to drop capabilities: %i, %s\n", err, strerror(err));
422 		return err;
423 	}
424 
425 	caps->initialized = true;
426 	return 0;
427 }
428 
429 static int restore_capabilities(struct cap_state *caps)
430 {
431 	int err;
432 
433 	if (!caps->initialized)
434 		return 0;
435 
436 	err = cap_enable_effective(caps->old_caps, NULL);
437 	if (err)
438 		PRINT_FAIL("failed to restore capabilities: %i, %s\n", err, strerror(err));
439 	caps->initialized = false;
440 	return err;
441 }
442 
443 static bool can_execute_unpriv(struct test_loader *tester, struct test_spec *spec)
444 {
445 	if (sysctl_unpriv_disabled < 0)
446 		sysctl_unpriv_disabled = get_unpriv_disabled() ? 1 : 0;
447 	if (sysctl_unpriv_disabled)
448 		return false;
449 	if ((spec->prog_flags & BPF_F_ANY_ALIGNMENT) && !EFFICIENT_UNALIGNED_ACCESS)
450 		return false;
451 	return true;
452 }
453 
454 static bool is_unpriv_capable_map(struct bpf_map *map)
455 {
456 	enum bpf_map_type type;
457 	__u32 flags;
458 
459 	type = bpf_map__type(map);
460 
461 	switch (type) {
462 	case BPF_MAP_TYPE_HASH:
463 	case BPF_MAP_TYPE_PERCPU_HASH:
464 	case BPF_MAP_TYPE_HASH_OF_MAPS:
465 		flags = bpf_map__map_flags(map);
466 		return !(flags & BPF_F_ZERO_SEED);
467 	case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
468 	case BPF_MAP_TYPE_ARRAY:
469 	case BPF_MAP_TYPE_RINGBUF:
470 	case BPF_MAP_TYPE_PROG_ARRAY:
471 	case BPF_MAP_TYPE_CGROUP_ARRAY:
472 	case BPF_MAP_TYPE_PERCPU_ARRAY:
473 	case BPF_MAP_TYPE_USER_RINGBUF:
474 	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
475 	case BPF_MAP_TYPE_CGROUP_STORAGE:
476 	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
477 		return true;
478 	default:
479 		return false;
480 	}
481 }
482 
483 static int do_prog_test_run(int fd_prog, int *retval)
484 {
485 	__u8 tmp_out[TEST_DATA_LEN << 2] = {};
486 	__u8 tmp_in[TEST_DATA_LEN] = {};
487 	int err, saved_errno;
488 	LIBBPF_OPTS(bpf_test_run_opts, topts,
489 		.data_in = tmp_in,
490 		.data_size_in = sizeof(tmp_in),
491 		.data_out = tmp_out,
492 		.data_size_out = sizeof(tmp_out),
493 		.repeat = 1,
494 	);
495 
496 	err = bpf_prog_test_run_opts(fd_prog, &topts);
497 	saved_errno = errno;
498 
499 	if (err) {
500 		PRINT_FAIL("FAIL: Unexpected bpf_prog_test_run error: %d (%s) ",
501 			   saved_errno, strerror(saved_errno));
502 		return err;
503 	}
504 
505 	ASSERT_OK(0, "bpf_prog_test_run");
506 	*retval = topts.retval;
507 
508 	return 0;
509 }
510 
511 static bool should_do_test_run(struct test_spec *spec, struct test_subspec *subspec)
512 {
513 	if (!subspec->execute)
514 		return false;
515 
516 	if (subspec->expect_failure)
517 		return false;
518 
519 	if ((spec->prog_flags & BPF_F_ANY_ALIGNMENT) && !EFFICIENT_UNALIGNED_ACCESS) {
520 		if (env.verbosity != VERBOSE_NONE)
521 			printf("alignment prevents execution\n");
522 		return false;
523 	}
524 
525 	return true;
526 }
527 
528 /* this function is forced noinline and has short generic name to look better
529  * in test_progs output (in case of a failure)
530  */
531 static noinline
532 void run_subtest(struct test_loader *tester,
533 		 struct bpf_object_open_opts *open_opts,
534 		 const void *obj_bytes,
535 		 size_t obj_byte_cnt,
536 		 struct test_spec *specs,
537 		 struct test_spec *spec,
538 		 bool unpriv)
539 {
540 	struct test_subspec *subspec = unpriv ? &spec->unpriv : &spec->priv;
541 	struct bpf_program *tprog, *tprog_iter;
542 	struct test_spec *spec_iter;
543 	struct cap_state caps = {};
544 	struct bpf_object *tobj;
545 	struct bpf_map *map;
546 	int retval, err, i;
547 	bool should_load;
548 
549 	if (!test__start_subtest(subspec->name))
550 		return;
551 
552 	if (unpriv) {
553 		if (!can_execute_unpriv(tester, spec)) {
554 			test__skip();
555 			test__end_subtest();
556 			return;
557 		}
558 		if (drop_capabilities(&caps)) {
559 			test__end_subtest();
560 			return;
561 		}
562 	}
563 
564 	tobj = bpf_object__open_mem(obj_bytes, obj_byte_cnt, open_opts);
565 	if (!ASSERT_OK_PTR(tobj, "obj_open_mem")) /* shouldn't happen */
566 		goto subtest_cleanup;
567 
568 	i = 0;
569 	bpf_object__for_each_program(tprog_iter, tobj) {
570 		spec_iter = &specs[i++];
571 		should_load = false;
572 
573 		if (spec_iter->valid) {
574 			if (strcmp(bpf_program__name(tprog_iter), spec->prog_name) == 0) {
575 				tprog = tprog_iter;
576 				should_load = true;
577 			}
578 
579 			if (spec_iter->auxiliary &&
580 			    spec_iter->mode_mask & (unpriv ? UNPRIV : PRIV))
581 				should_load = true;
582 		}
583 
584 		bpf_program__set_autoload(tprog_iter, should_load);
585 	}
586 
587 	prepare_case(tester, spec, tobj, tprog);
588 
589 	/* By default bpf_object__load() automatically creates all
590 	 * maps declared in the skeleton. Some map types are only
591 	 * allowed in priv mode. Disable autoload for such maps in
592 	 * unpriv mode.
593 	 */
594 	bpf_object__for_each_map(map, tobj)
595 		bpf_map__set_autocreate(map, !unpriv || is_unpriv_capable_map(map));
596 
597 	err = bpf_object__load(tobj);
598 	if (subspec->expect_failure) {
599 		if (!ASSERT_ERR(err, "unexpected_load_success")) {
600 			emit_verifier_log(tester->log_buf, false /*force*/);
601 			goto tobj_cleanup;
602 		}
603 	} else {
604 		if (!ASSERT_OK(err, "unexpected_load_failure")) {
605 			emit_verifier_log(tester->log_buf, true /*force*/);
606 			goto tobj_cleanup;
607 		}
608 	}
609 
610 	emit_verifier_log(tester->log_buf, false /*force*/);
611 	validate_case(tester, subspec, tobj, tprog, err);
612 
613 	if (should_do_test_run(spec, subspec)) {
614 		/* For some reason test_verifier executes programs
615 		 * with all capabilities restored. Do the same here.
616 		 */
617 		if (restore_capabilities(&caps))
618 			goto tobj_cleanup;
619 
620 		if (tester->pre_execution_cb) {
621 			err = tester->pre_execution_cb(tobj);
622 			if (err) {
623 				PRINT_FAIL("pre_execution_cb failed: %d\n", err);
624 				goto tobj_cleanup;
625 			}
626 		}
627 
628 		do_prog_test_run(bpf_program__fd(tprog), &retval);
629 		if (retval != subspec->retval && subspec->retval != POINTER_VALUE) {
630 			PRINT_FAIL("Unexpected retval: %d != %d\n", retval, subspec->retval);
631 			goto tobj_cleanup;
632 		}
633 	}
634 
635 tobj_cleanup:
636 	bpf_object__close(tobj);
637 subtest_cleanup:
638 	test__end_subtest();
639 	restore_capabilities(&caps);
640 }
641 
642 static void process_subtest(struct test_loader *tester,
643 			    const char *skel_name,
644 			    skel_elf_bytes_fn elf_bytes_factory)
645 {
646 	LIBBPF_OPTS(bpf_object_open_opts, open_opts, .object_name = skel_name);
647 	struct test_spec *specs = NULL;
648 	struct bpf_object *obj = NULL;
649 	struct bpf_program *prog;
650 	const void *obj_bytes;
651 	int err, i, nr_progs;
652 	size_t obj_byte_cnt;
653 
654 	if (tester_init(tester) < 0)
655 		return; /* failed to initialize tester */
656 
657 	obj_bytes = elf_bytes_factory(&obj_byte_cnt);
658 	obj = bpf_object__open_mem(obj_bytes, obj_byte_cnt, &open_opts);
659 	if (!ASSERT_OK_PTR(obj, "obj_open_mem"))
660 		return;
661 
662 	nr_progs = 0;
663 	bpf_object__for_each_program(prog, obj)
664 		++nr_progs;
665 
666 	specs = calloc(nr_progs, sizeof(struct test_spec));
667 	if (!ASSERT_OK_PTR(specs, "Can't alloc specs array"))
668 		return;
669 
670 	i = 0;
671 	bpf_object__for_each_program(prog, obj) {
672 		/* ignore tests for which  we can't derive test specification */
673 		err = parse_test_spec(tester, obj, prog, &specs[i++]);
674 		if (err)
675 			PRINT_FAIL("Can't parse test spec for program '%s'\n",
676 				   bpf_program__name(prog));
677 	}
678 
679 	i = 0;
680 	bpf_object__for_each_program(prog, obj) {
681 		struct test_spec *spec = &specs[i++];
682 
683 		if (!spec->valid || spec->auxiliary)
684 			continue;
685 
686 		if (spec->mode_mask & PRIV)
687 			run_subtest(tester, &open_opts, obj_bytes, obj_byte_cnt,
688 				    specs, spec, false);
689 		if (spec->mode_mask & UNPRIV)
690 			run_subtest(tester, &open_opts, obj_bytes, obj_byte_cnt,
691 				    specs, spec, true);
692 
693 	}
694 
695 	for (i = 0; i < nr_progs; ++i)
696 		free_test_spec(&specs[i]);
697 	free(specs);
698 	bpf_object__close(obj);
699 }
700 
701 void test_loader__run_subtests(struct test_loader *tester,
702 			       const char *skel_name,
703 			       skel_elf_bytes_fn elf_bytes_factory)
704 {
705 	/* see comment in run_subtest() for why we do this function nesting */
706 	process_subtest(tester, skel_name, elf_bytes_factory);
707 }
708