1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2022 Red Hat */
3 #include "hid.skel.h"
4 
5 #include "../kselftest_harness.h"
6 
7 #include <bpf/bpf.h>
8 #include <fcntl.h>
9 #include <fnmatch.h>
10 #include <dirent.h>
11 #include <poll.h>
12 #include <pthread.h>
13 #include <stdbool.h>
14 #include <linux/hidraw.h>
15 #include <linux/uhid.h>
16 
17 #define SHOW_UHID_DEBUG 0
18 
19 static unsigned char rdesc[] = {
20 	0x06, 0x00, 0xff,	/* Usage Page (Vendor Defined Page 1) */
21 	0x09, 0x21,		/* Usage (Vendor Usage 0x21) */
22 	0xa1, 0x01,		/* COLLECTION (Application) */
23 	0x09, 0x01,			/* Usage (Vendor Usage 0x01) */
24 	0xa1, 0x00,			/* COLLECTION (Physical) */
25 	0x85, 0x01,				/* REPORT_ID (1) */
26 	0x06, 0x00, 0xff,			/* Usage Page (Vendor Defined Page 1) */
27 	0x19, 0x01,				/* USAGE_MINIMUM (1) */
28 	0x29, 0x03,				/* USAGE_MAXIMUM (3) */
29 	0x15, 0x00,				/* LOGICAL_MINIMUM (0) */
30 	0x25, 0x01,				/* LOGICAL_MAXIMUM (1) */
31 	0x95, 0x03,				/* REPORT_COUNT (3) */
32 	0x75, 0x01,				/* REPORT_SIZE (1) */
33 	0x81, 0x02,				/* INPUT (Data,Var,Abs) */
34 	0x95, 0x01,				/* REPORT_COUNT (1) */
35 	0x75, 0x05,				/* REPORT_SIZE (5) */
36 	0x81, 0x01,				/* INPUT (Cnst,Var,Abs) */
37 	0x05, 0x01,				/* USAGE_PAGE (Generic Desktop) */
38 	0x09, 0x30,				/* USAGE (X) */
39 	0x09, 0x31,				/* USAGE (Y) */
40 	0x15, 0x81,				/* LOGICAL_MINIMUM (-127) */
41 	0x25, 0x7f,				/* LOGICAL_MAXIMUM (127) */
42 	0x75, 0x10,				/* REPORT_SIZE (16) */
43 	0x95, 0x02,				/* REPORT_COUNT (2) */
44 	0x81, 0x06,				/* INPUT (Data,Var,Rel) */
45 
46 	0x06, 0x00, 0xff,			/* Usage Page (Vendor Defined Page 1) */
47 	0x19, 0x01,				/* USAGE_MINIMUM (1) */
48 	0x29, 0x03,				/* USAGE_MAXIMUM (3) */
49 	0x15, 0x00,				/* LOGICAL_MINIMUM (0) */
50 	0x25, 0x01,				/* LOGICAL_MAXIMUM (1) */
51 	0x95, 0x03,				/* REPORT_COUNT (3) */
52 	0x75, 0x01,				/* REPORT_SIZE (1) */
53 	0x91, 0x02,				/* Output (Data,Var,Abs) */
54 	0x95, 0x01,				/* REPORT_COUNT (1) */
55 	0x75, 0x05,				/* REPORT_SIZE (5) */
56 	0x91, 0x01,				/* Output (Cnst,Var,Abs) */
57 
58 	0x06, 0x00, 0xff,			/* Usage Page (Vendor Defined Page 1) */
59 	0x19, 0x06,				/* USAGE_MINIMUM (6) */
60 	0x29, 0x08,				/* USAGE_MAXIMUM (8) */
61 	0x15, 0x00,				/* LOGICAL_MINIMUM (0) */
62 	0x25, 0x01,				/* LOGICAL_MAXIMUM (1) */
63 	0x95, 0x03,				/* REPORT_COUNT (3) */
64 	0x75, 0x01,				/* REPORT_SIZE (1) */
65 	0xb1, 0x02,				/* Feature (Data,Var,Abs) */
66 	0x95, 0x01,				/* REPORT_COUNT (1) */
67 	0x75, 0x05,				/* REPORT_SIZE (5) */
68 	0x91, 0x01,				/* Output (Cnst,Var,Abs) */
69 
70 	0xc0,				/* END_COLLECTION */
71 	0xc0,			/* END_COLLECTION */
72 };
73 
74 struct attach_prog_args {
75 	int prog_fd;
76 	unsigned int hid;
77 	int retval;
78 };
79 
80 #define ASSERT_OK(data) ASSERT_FALSE(data)
81 #define ASSERT_OK_PTR(ptr) ASSERT_NE(NULL, ptr)
82 
83 #define UHID_LOG(fmt, ...) do { \
84 	if (SHOW_UHID_DEBUG) \
85 		TH_LOG(fmt, ##__VA_ARGS__); \
86 } while (0)
87 
88 static pthread_mutex_t uhid_started_mtx = PTHREAD_MUTEX_INITIALIZER;
89 static pthread_cond_t uhid_started = PTHREAD_COND_INITIALIZER;
90 
91 /* no need to protect uhid_stopped, only one thread accesses it */
92 static bool uhid_stopped;
93 
94 static int uhid_write(struct __test_metadata *_metadata, int fd, const struct uhid_event *ev)
95 {
96 	ssize_t ret;
97 
98 	ret = write(fd, ev, sizeof(*ev));
99 	if (ret < 0) {
100 		TH_LOG("Cannot write to uhid: %m");
101 		return -errno;
102 	} else if (ret != sizeof(*ev)) {
103 		TH_LOG("Wrong size written to uhid: %zd != %zu",
104 			ret, sizeof(ev));
105 		return -EFAULT;
106 	} else {
107 		return 0;
108 	}
109 }
110 
111 static int uhid_create(struct __test_metadata *_metadata, int fd, int rand_nb)
112 {
113 	struct uhid_event ev;
114 	char buf[25];
115 
116 	sprintf(buf, "test-uhid-device-%d", rand_nb);
117 
118 	memset(&ev, 0, sizeof(ev));
119 	ev.type = UHID_CREATE;
120 	strcpy((char *)ev.u.create.name, buf);
121 	ev.u.create.rd_data = rdesc;
122 	ev.u.create.rd_size = sizeof(rdesc);
123 	ev.u.create.bus = BUS_USB;
124 	ev.u.create.vendor = 0x0001;
125 	ev.u.create.product = 0x0a37;
126 	ev.u.create.version = 0;
127 	ev.u.create.country = 0;
128 
129 	sprintf(buf, "%d", rand_nb);
130 	strcpy((char *)ev.u.create.phys, buf);
131 
132 	return uhid_write(_metadata, fd, &ev);
133 }
134 
135 static void uhid_destroy(struct __test_metadata *_metadata, int fd)
136 {
137 	struct uhid_event ev;
138 
139 	memset(&ev, 0, sizeof(ev));
140 	ev.type = UHID_DESTROY;
141 
142 	uhid_write(_metadata, fd, &ev);
143 }
144 
145 static int uhid_event(struct __test_metadata *_metadata, int fd)
146 {
147 	struct uhid_event ev;
148 	ssize_t ret;
149 
150 	memset(&ev, 0, sizeof(ev));
151 	ret = read(fd, &ev, sizeof(ev));
152 	if (ret == 0) {
153 		UHID_LOG("Read HUP on uhid-cdev");
154 		return -EFAULT;
155 	} else if (ret < 0) {
156 		UHID_LOG("Cannot read uhid-cdev: %m");
157 		return -errno;
158 	} else if (ret != sizeof(ev)) {
159 		UHID_LOG("Invalid size read from uhid-dev: %zd != %zu",
160 			ret, sizeof(ev));
161 		return -EFAULT;
162 	}
163 
164 	switch (ev.type) {
165 	case UHID_START:
166 		pthread_mutex_lock(&uhid_started_mtx);
167 		pthread_cond_signal(&uhid_started);
168 		pthread_mutex_unlock(&uhid_started_mtx);
169 
170 		UHID_LOG("UHID_START from uhid-dev");
171 		break;
172 	case UHID_STOP:
173 		uhid_stopped = true;
174 
175 		UHID_LOG("UHID_STOP from uhid-dev");
176 		break;
177 	case UHID_OPEN:
178 		UHID_LOG("UHID_OPEN from uhid-dev");
179 		break;
180 	case UHID_CLOSE:
181 		UHID_LOG("UHID_CLOSE from uhid-dev");
182 		break;
183 	case UHID_OUTPUT:
184 		UHID_LOG("UHID_OUTPUT from uhid-dev");
185 		break;
186 	case UHID_GET_REPORT:
187 		UHID_LOG("UHID_GET_REPORT from uhid-dev");
188 		break;
189 	case UHID_SET_REPORT:
190 		UHID_LOG("UHID_SET_REPORT from uhid-dev");
191 		break;
192 	default:
193 		TH_LOG("Invalid event from uhid-dev: %u", ev.type);
194 	}
195 
196 	return 0;
197 }
198 
199 struct uhid_thread_args {
200 	int fd;
201 	struct __test_metadata *_metadata;
202 };
203 static void *uhid_read_events_thread(void *arg)
204 {
205 	struct uhid_thread_args *args = (struct uhid_thread_args *)arg;
206 	struct __test_metadata *_metadata = args->_metadata;
207 	struct pollfd pfds[1];
208 	int fd = args->fd;
209 	int ret = 0;
210 
211 	pfds[0].fd = fd;
212 	pfds[0].events = POLLIN;
213 
214 	uhid_stopped = false;
215 
216 	while (!uhid_stopped) {
217 		ret = poll(pfds, 1, 100);
218 		if (ret < 0) {
219 			TH_LOG("Cannot poll for fds: %m");
220 			break;
221 		}
222 		if (pfds[0].revents & POLLIN) {
223 			ret = uhid_event(_metadata, fd);
224 			if (ret)
225 				break;
226 		}
227 	}
228 
229 	return (void *)(long)ret;
230 }
231 
232 static int uhid_start_listener(struct __test_metadata *_metadata, pthread_t *tid, int uhid_fd)
233 {
234 	struct uhid_thread_args args = {
235 		.fd = uhid_fd,
236 		._metadata = _metadata,
237 	};
238 	int err;
239 
240 	pthread_mutex_lock(&uhid_started_mtx);
241 	err = pthread_create(tid, NULL, uhid_read_events_thread, (void *)&args);
242 	ASSERT_EQ(0, err) {
243 		TH_LOG("Could not start the uhid thread: %d", err);
244 		pthread_mutex_unlock(&uhid_started_mtx);
245 		close(uhid_fd);
246 		return -EIO;
247 	}
248 	pthread_cond_wait(&uhid_started, &uhid_started_mtx);
249 	pthread_mutex_unlock(&uhid_started_mtx);
250 
251 	return 0;
252 }
253 
254 static int uhid_send_event(struct __test_metadata *_metadata, int fd, __u8 *buf, size_t size)
255 {
256 	struct uhid_event ev;
257 
258 	if (size > sizeof(ev.u.input.data))
259 		return -E2BIG;
260 
261 	memset(&ev, 0, sizeof(ev));
262 	ev.type = UHID_INPUT2;
263 	ev.u.input2.size = size;
264 
265 	memcpy(ev.u.input2.data, buf, size);
266 
267 	return uhid_write(_metadata, fd, &ev);
268 }
269 
270 static int setup_uhid(struct __test_metadata *_metadata, int rand_nb)
271 {
272 	int fd;
273 	const char *path = "/dev/uhid";
274 	int ret;
275 
276 	fd = open(path, O_RDWR | O_CLOEXEC);
277 	ASSERT_GE(fd, 0) TH_LOG("open uhid-cdev failed; %d", fd);
278 
279 	ret = uhid_create(_metadata, fd, rand_nb);
280 	ASSERT_EQ(0, ret) {
281 		TH_LOG("create uhid device failed: %d", ret);
282 		close(fd);
283 	}
284 
285 	return fd;
286 }
287 
288 static bool match_sysfs_device(int dev_id, const char *workdir, struct dirent *dir)
289 {
290 	const char *target = "0003:0001:0A37.*";
291 	char phys[512];
292 	char uevent[1024];
293 	char temp[512];
294 	int fd, nread;
295 	bool found = false;
296 
297 	if (fnmatch(target, dir->d_name, 0))
298 		return false;
299 
300 	/* we found the correct VID/PID, now check for phys */
301 	sprintf(uevent, "%s/%s/uevent", workdir, dir->d_name);
302 
303 	fd = open(uevent, O_RDONLY | O_NONBLOCK);
304 	if (fd < 0)
305 		return false;
306 
307 	sprintf(phys, "PHYS=%d", dev_id);
308 
309 	nread = read(fd, temp, ARRAY_SIZE(temp));
310 	if (nread > 0 && (strstr(temp, phys)) != NULL)
311 		found = true;
312 
313 	close(fd);
314 
315 	return found;
316 }
317 
318 static int get_hid_id(int dev_id)
319 {
320 	const char *workdir = "/sys/devices/virtual/misc/uhid";
321 	const char *str_id;
322 	DIR *d;
323 	struct dirent *dir;
324 	int found = -1, attempts = 3;
325 
326 	/* it would be nice to be able to use nftw, but the no_alu32 target doesn't support it */
327 
328 	while (found < 0 && attempts > 0) {
329 		attempts--;
330 		d = opendir(workdir);
331 		if (d) {
332 			while ((dir = readdir(d)) != NULL) {
333 				if (!match_sysfs_device(dev_id, workdir, dir))
334 					continue;
335 
336 				str_id = dir->d_name + sizeof("0003:0001:0A37.");
337 				found = (int)strtol(str_id, NULL, 16);
338 
339 				break;
340 			}
341 			closedir(d);
342 		}
343 		if (found < 0)
344 			usleep(100000);
345 	}
346 
347 	return found;
348 }
349 
350 static int get_hidraw(int dev_id)
351 {
352 	const char *workdir = "/sys/devices/virtual/misc/uhid";
353 	char sysfs[1024];
354 	DIR *d, *subd;
355 	struct dirent *dir, *subdir;
356 	int i, found = -1;
357 
358 	/* retry 5 times in case the system is loaded */
359 	for (i = 5; i > 0; i--) {
360 		usleep(10);
361 		d = opendir(workdir);
362 
363 		if (!d)
364 			continue;
365 
366 		while ((dir = readdir(d)) != NULL) {
367 			if (!match_sysfs_device(dev_id, workdir, dir))
368 				continue;
369 
370 			sprintf(sysfs, "%s/%s/hidraw", workdir, dir->d_name);
371 
372 			subd = opendir(sysfs);
373 			if (!subd)
374 				continue;
375 
376 			while ((subdir = readdir(subd)) != NULL) {
377 				if (fnmatch("hidraw*", subdir->d_name, 0))
378 					continue;
379 
380 				found = atoi(subdir->d_name + strlen("hidraw"));
381 			}
382 
383 			closedir(subd);
384 
385 			if (found > 0)
386 				break;
387 		}
388 		closedir(d);
389 	}
390 
391 	return found;
392 }
393 
394 static int open_hidraw(int dev_id)
395 {
396 	int hidraw_number;
397 	char hidraw_path[64] = { 0 };
398 
399 	hidraw_number = get_hidraw(dev_id);
400 	if (hidraw_number < 0)
401 		return hidraw_number;
402 
403 	/* open hidraw node to check the other side of the pipe */
404 	sprintf(hidraw_path, "/dev/hidraw%d", hidraw_number);
405 	return open(hidraw_path, O_RDWR | O_NONBLOCK);
406 }
407 
408 FIXTURE(hid_bpf) {
409 	int dev_id;
410 	int uhid_fd;
411 	int hidraw_fd;
412 	int hid_id;
413 	pthread_t tid;
414 	struct hid *skel;
415 };
416 static void detach_bpf(FIXTURE_DATA(hid_bpf) * self)
417 {
418 	if (self->hidraw_fd)
419 		close(self->hidraw_fd);
420 	self->hidraw_fd = 0;
421 
422 	hid__destroy(self->skel);
423 	self->skel = NULL;
424 }
425 
426 FIXTURE_TEARDOWN(hid_bpf) {
427 	void *uhid_err;
428 
429 	uhid_destroy(_metadata, self->uhid_fd);
430 
431 	detach_bpf(self);
432 	pthread_join(self->tid, &uhid_err);
433 }
434 #define TEARDOWN_LOG(fmt, ...) do { \
435 	TH_LOG(fmt, ##__VA_ARGS__); \
436 	hid_bpf_teardown(_metadata, self, variant); \
437 } while (0)
438 
439 FIXTURE_SETUP(hid_bpf)
440 {
441 	time_t t;
442 	int err;
443 
444 	/* initialize random number generator */
445 	srand((unsigned int)time(&t));
446 
447 	self->dev_id = rand() % 1024;
448 
449 	self->uhid_fd = setup_uhid(_metadata, self->dev_id);
450 
451 	/* locate the uev, self, variant);ent file of the created device */
452 	self->hid_id = get_hid_id(self->dev_id);
453 	ASSERT_GT(self->hid_id, 0)
454 		TEARDOWN_LOG("Could not locate uhid device id: %d", self->hid_id);
455 
456 	err = uhid_start_listener(_metadata, &self->tid, self->uhid_fd);
457 	ASSERT_EQ(0, err) TEARDOWN_LOG("could not start udev listener: %d", err);
458 }
459 
460 struct test_program {
461 	const char *name;
462 };
463 #define LOAD_PROGRAMS(progs) \
464 	load_programs(progs, ARRAY_SIZE(progs), _metadata, self, variant)
465 #define LOAD_BPF \
466 	load_programs(NULL, 0, _metadata, self, variant)
467 static void load_programs(const struct test_program programs[],
468 			  const size_t progs_count,
469 			  struct __test_metadata *_metadata,
470 			  FIXTURE_DATA(hid_bpf) * self,
471 			  const FIXTURE_VARIANT(hid_bpf) * variant)
472 {
473 	int attach_fd, err = -EINVAL;
474 	struct attach_prog_args args = {
475 		.retval = -1,
476 	};
477 	DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattr,
478 			    .ctx_in = &args,
479 			    .ctx_size_in = sizeof(args),
480 	);
481 
482 	/* open the bpf file */
483 	self->skel = hid__open();
484 	ASSERT_OK_PTR(self->skel) TEARDOWN_LOG("Error while calling hid__open");
485 
486 	for (int i = 0; i < progs_count; i++) {
487 		struct bpf_program *prog;
488 
489 		prog = bpf_object__find_program_by_name(*self->skel->skeleton->obj,
490 							programs[i].name);
491 		ASSERT_OK_PTR(prog) TH_LOG("can not find program by name '%s'", programs[i].name);
492 
493 		bpf_program__set_autoload(prog, true);
494 	}
495 
496 	err = hid__load(self->skel);
497 	ASSERT_OK(err) TH_LOG("hid_skel_load failed: %d", err);
498 
499 	attach_fd = bpf_program__fd(self->skel->progs.attach_prog);
500 	ASSERT_GE(attach_fd, 0) TH_LOG("locate attach_prog: %d", attach_fd);
501 
502 	for (int i = 0; i < progs_count; i++) {
503 		struct bpf_program *prog;
504 
505 		prog = bpf_object__find_program_by_name(*self->skel->skeleton->obj,
506 							programs[i].name);
507 		ASSERT_OK_PTR(prog) TH_LOG("can not find program by name '%s'", programs[i].name);
508 
509 		args.prog_fd = bpf_program__fd(prog);
510 		args.hid = self->hid_id;
511 		err = bpf_prog_test_run_opts(attach_fd, &tattr);
512 		ASSERT_OK(args.retval) TH_LOG("attach_hid(%s): %d", programs[i].name, args.retval);
513 	}
514 
515 	self->hidraw_fd = open_hidraw(self->dev_id);
516 	ASSERT_GE(self->hidraw_fd, 0) TH_LOG("open_hidraw");
517 }
518 
519 /*
520  * A simple test to see if the fixture is working fine.
521  * If this fails, none of the other tests will pass.
522  */
523 TEST_F(hid_bpf, test_create_uhid)
524 {
525 }
526 
527 /*
528  * Attach hid_first_event to the given uhid device,
529  * retrieve and open the matching hidraw node,
530  * inject one event in the uhid device,
531  * check that the program sees it and can change the data
532  */
533 TEST_F(hid_bpf, raw_event)
534 {
535 	const struct test_program progs[] = {
536 		{ .name = "hid_first_event" },
537 	};
538 	__u8 buf[10] = {0};
539 	int err;
540 
541 	LOAD_PROGRAMS(progs);
542 
543 	/* check that the program is correctly loaded */
544 	ASSERT_EQ(self->skel->data->callback_check, 52) TH_LOG("callback_check1");
545 	ASSERT_EQ(self->skel->data->callback2_check, 52) TH_LOG("callback2_check1");
546 
547 	/* inject one event */
548 	buf[0] = 1;
549 	buf[1] = 42;
550 	uhid_send_event(_metadata, self->uhid_fd, buf, 6);
551 
552 	/* check that hid_first_event() was executed */
553 	ASSERT_EQ(self->skel->data->callback_check, 42) TH_LOG("callback_check1");
554 
555 	/* read the data from hidraw */
556 	memset(buf, 0, sizeof(buf));
557 	err = read(self->hidraw_fd, buf, sizeof(buf));
558 	ASSERT_EQ(err, 6) TH_LOG("read_hidraw");
559 	ASSERT_EQ(buf[0], 1);
560 	ASSERT_EQ(buf[2], 47);
561 
562 	/* inject another event */
563 	memset(buf, 0, sizeof(buf));
564 	buf[0] = 1;
565 	buf[1] = 47;
566 	uhid_send_event(_metadata, self->uhid_fd, buf, 6);
567 
568 	/* check that hid_first_event() was executed */
569 	ASSERT_EQ(self->skel->data->callback_check, 47) TH_LOG("callback_check1");
570 
571 	/* read the data from hidraw */
572 	memset(buf, 0, sizeof(buf));
573 	err = read(self->hidraw_fd, buf, sizeof(buf));
574 	ASSERT_EQ(err, 6) TH_LOG("read_hidraw");
575 	ASSERT_EQ(buf[2], 52);
576 }
577 
578 /*
579  * Ensures that we can attach/detach programs
580  */
581 TEST_F(hid_bpf, test_attach_detach)
582 {
583 	const struct test_program progs[] = {
584 		{ .name = "hid_first_event" },
585 	};
586 	__u8 buf[10] = {0};
587 	int err;
588 
589 	LOAD_PROGRAMS(progs);
590 
591 	/* inject one event */
592 	buf[0] = 1;
593 	buf[1] = 42;
594 	uhid_send_event(_metadata, self->uhid_fd, buf, 6);
595 
596 	/* read the data from hidraw */
597 	memset(buf, 0, sizeof(buf));
598 	err = read(self->hidraw_fd, buf, sizeof(buf));
599 	ASSERT_EQ(err, 6) TH_LOG("read_hidraw");
600 	ASSERT_EQ(buf[0], 1);
601 	ASSERT_EQ(buf[2], 47);
602 
603 	/* pin the program and immediately unpin it */
604 #define PIN_PATH "/sys/fs/bpf/hid_first_event"
605 	bpf_program__pin(self->skel->progs.hid_first_event, PIN_PATH);
606 	remove(PIN_PATH);
607 #undef PIN_PATH
608 	usleep(100000);
609 
610 	/* detach the program */
611 	detach_bpf(self);
612 
613 	self->hidraw_fd = open_hidraw(self->dev_id);
614 	ASSERT_GE(self->hidraw_fd, 0) TH_LOG("open_hidraw");
615 
616 	/* inject another event */
617 	memset(buf, 0, sizeof(buf));
618 	buf[0] = 1;
619 	buf[1] = 47;
620 	uhid_send_event(_metadata, self->uhid_fd, buf, 6);
621 
622 	/* read the data from hidraw */
623 	memset(buf, 0, sizeof(buf));
624 	err = read(self->hidraw_fd, buf, sizeof(buf));
625 	ASSERT_EQ(err, 6) TH_LOG("read_hidraw_no_bpf");
626 	ASSERT_EQ(buf[0], 1);
627 	ASSERT_EQ(buf[1], 47);
628 	ASSERT_EQ(buf[2], 0);
629 
630 	/* re-attach our program */
631 
632 	LOAD_PROGRAMS(progs);
633 
634 	/* inject one event */
635 	memset(buf, 0, sizeof(buf));
636 	buf[0] = 1;
637 	buf[1] = 42;
638 	uhid_send_event(_metadata, self->uhid_fd, buf, 6);
639 
640 	/* read the data from hidraw */
641 	memset(buf, 0, sizeof(buf));
642 	err = read(self->hidraw_fd, buf, sizeof(buf));
643 	ASSERT_EQ(err, 6) TH_LOG("read_hidraw");
644 	ASSERT_EQ(buf[0], 1);
645 	ASSERT_EQ(buf[2], 47);
646 }
647 
648 static int libbpf_print_fn(enum libbpf_print_level level,
649 			   const char *format, va_list args)
650 {
651 	char buf[1024];
652 
653 	if (level == LIBBPF_DEBUG)
654 		return 0;
655 
656 	snprintf(buf, sizeof(buf), "# %s", format);
657 
658 	vfprintf(stdout, buf, args);
659 	return 0;
660 }
661 
662 static void __attribute__((constructor)) __constructor_order_last(void)
663 {
664 	if (!__constructor_order)
665 		__constructor_order = _CONSTRUCTOR_ORDER_BACKWARD;
666 }
667 
668 int main(int argc, char **argv)
669 {
670 	/* Use libbpf 1.0 API mode */
671 	libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
672 	libbpf_set_print(libbpf_print_fn);
673 
674 	return test_harness_run(argc, argv);
675 }
676