1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * User Events FTrace Test Program
4  *
5  * Copyright (c) 2021 Beau Belgrave <beaub@linux.microsoft.com>
6  */
7 
8 #include <errno.h>
9 #include <linux/user_events.h>
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <fcntl.h>
13 #include <sys/ioctl.h>
14 #include <sys/stat.h>
15 #include <sys/uio.h>
16 #include <unistd.h>
17 
18 #include "../kselftest_harness.h"
19 #include "user_events_selftests.h"
20 
21 const char *data_file = "/sys/kernel/tracing/user_events_data";
22 const char *status_file = "/sys/kernel/tracing/user_events_status";
23 const char *enable_file = "/sys/kernel/tracing/events/user_events/__test_event/enable";
24 const char *trace_file = "/sys/kernel/tracing/trace";
25 const char *fmt_file = "/sys/kernel/tracing/events/user_events/__test_event/format";
26 
27 static int trace_bytes(void)
28 {
29 	int fd = open(trace_file, O_RDONLY);
30 	char buf[256];
31 	int bytes = 0, got;
32 
33 	if (fd == -1)
34 		return -1;
35 
36 	while (true) {
37 		got = read(fd, buf, sizeof(buf));
38 
39 		if (got == -1)
40 			return -1;
41 
42 		if (got == 0)
43 			break;
44 
45 		bytes += got;
46 	}
47 
48 	close(fd);
49 
50 	return bytes;
51 }
52 
53 static int skip_until_empty_line(FILE *fp)
54 {
55 	int c, last = 0;
56 
57 	while (true) {
58 		c = getc(fp);
59 
60 		if (c == EOF)
61 			break;
62 
63 		if (last == '\n' && c == '\n')
64 			return 0;
65 
66 		last = c;
67 	}
68 
69 	return -1;
70 }
71 
72 static int get_print_fmt(char *buffer, int len)
73 {
74 	FILE *fp = fopen(fmt_file, "r");
75 	char *newline;
76 
77 	if (!fp)
78 		return -1;
79 
80 	/* Read until empty line (Skip Common) */
81 	if (skip_until_empty_line(fp) < 0)
82 		goto err;
83 
84 	/* Read until empty line (Skip Properties) */
85 	if (skip_until_empty_line(fp) < 0)
86 		goto err;
87 
88 	/* Read in print_fmt: */
89 	if (fgets(buffer, len, fp) == NULL)
90 		goto err;
91 
92 	newline = strchr(buffer, '\n');
93 
94 	if (newline)
95 		*newline = '\0';
96 
97 	fclose(fp);
98 
99 	return 0;
100 err:
101 	fclose(fp);
102 
103 	return -1;
104 }
105 
106 static bool wait_for_delete(void)
107 {
108 	int i;
109 
110 	for (i = 0; i < 1000; ++i) {
111 		int fd = open(enable_file, O_RDONLY);
112 
113 		if (fd == -1)
114 			return true;
115 
116 		close(fd);
117 		usleep(1000);
118 	}
119 
120 	return false;
121 }
122 
123 static int clear(int *check)
124 {
125 	struct user_unreg unreg = {0};
126 	int fd;
127 
128 	unreg.size = sizeof(unreg);
129 	unreg.disable_bit = 31;
130 	unreg.disable_addr = (__u64)check;
131 
132 	fd = open(data_file, O_RDWR);
133 
134 	if (fd == -1)
135 		return -1;
136 
137 	if (ioctl(fd, DIAG_IOCSUNREG, &unreg) == -1)
138 		if (errno != ENOENT)
139 			goto fail;
140 
141 	if (ioctl(fd, DIAG_IOCSDEL, "__test_event") == -1) {
142 		if (errno == EBUSY) {
143 			if (!wait_for_delete())
144 				goto fail;
145 		} else if (errno != ENOENT)
146 			goto fail;
147 	}
148 
149 	close(fd);
150 
151 	return 0;
152 fail:
153 	close(fd);
154 
155 	return -1;
156 }
157 
158 static int check_print_fmt(const char *event, const char *expected, int *check)
159 {
160 	struct user_reg reg = {0};
161 	char print_fmt[256];
162 	int ret;
163 	int fd;
164 
165 	/* Ensure cleared */
166 	ret = clear(check);
167 
168 	if (ret != 0)
169 		return ret;
170 
171 	fd = open(data_file, O_RDWR);
172 
173 	if (fd == -1)
174 		return fd;
175 
176 	reg.size = sizeof(reg);
177 	reg.name_args = (__u64)event;
178 	reg.enable_bit = 31;
179 	reg.enable_addr = (__u64)check;
180 	reg.enable_size = sizeof(*check);
181 
182 	/* Register should work */
183 	ret = ioctl(fd, DIAG_IOCSREG, &reg);
184 
185 	if (ret != 0) {
186 		close(fd);
187 		printf("Reg failed in fmt\n");
188 		return ret;
189 	}
190 
191 	/* Ensure correct print_fmt */
192 	ret = get_print_fmt(print_fmt, sizeof(print_fmt));
193 
194 	close(fd);
195 
196 	if (ret != 0)
197 		return ret;
198 
199 	return strcmp(print_fmt, expected);
200 }
201 
202 FIXTURE(user) {
203 	int status_fd;
204 	int data_fd;
205 	int enable_fd;
206 	int check;
207 };
208 
209 FIXTURE_SETUP(user) {
210 	USER_EVENT_FIXTURE_SETUP(return);
211 
212 	self->status_fd = open(status_file, O_RDONLY);
213 	ASSERT_NE(-1, self->status_fd);
214 
215 	self->data_fd = open(data_file, O_RDWR);
216 	ASSERT_NE(-1, self->data_fd);
217 
218 	self->enable_fd = -1;
219 }
220 
221 FIXTURE_TEARDOWN(user) {
222 	close(self->status_fd);
223 	close(self->data_fd);
224 
225 	if (self->enable_fd != -1) {
226 		write(self->enable_fd, "0", sizeof("0"));
227 		close(self->enable_fd);
228 	}
229 
230 	if (clear(&self->check) != 0)
231 		printf("WARNING: Clear didn't work!\n");
232 }
233 
234 TEST_F(user, register_events) {
235 	struct user_reg reg = {0};
236 	struct user_unreg unreg = {0};
237 
238 	reg.size = sizeof(reg);
239 	reg.name_args = (__u64)"__test_event u32 field1; u32 field2";
240 	reg.enable_bit = 31;
241 	reg.enable_addr = (__u64)&self->check;
242 	reg.enable_size = sizeof(self->check);
243 
244 	unreg.size = sizeof(unreg);
245 	unreg.disable_bit = 31;
246 	unreg.disable_addr = (__u64)&self->check;
247 
248 	/* Register should work */
249 	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
250 	ASSERT_EQ(0, reg.write_index);
251 
252 	/* Multiple registers to the same addr + bit should fail */
253 	ASSERT_EQ(-1, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
254 	ASSERT_EQ(EADDRINUSE, errno);
255 
256 	/* Multiple registers to same name should result in same index */
257 	reg.enable_bit = 30;
258 	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
259 	ASSERT_EQ(0, reg.write_index);
260 
261 	/* Multiple registers to same name but different args should fail */
262 	reg.enable_bit = 29;
263 	reg.name_args = (__u64)"__test_event u32 field1;";
264 	ASSERT_EQ(-1, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
265 	ASSERT_EQ(EADDRINUSE, errno);
266 
267 	/* Ensure disabled */
268 	self->enable_fd = open(enable_file, O_RDWR);
269 	ASSERT_NE(-1, self->enable_fd);
270 	ASSERT_NE(-1, write(self->enable_fd, "0", sizeof("0")))
271 
272 	/* Enable event and ensure bits updated in status */
273 	ASSERT_NE(-1, write(self->enable_fd, "1", sizeof("1")))
274 	ASSERT_EQ(1 << reg.enable_bit, self->check);
275 
276 	/* Disable event and ensure bits updated in status */
277 	ASSERT_NE(-1, write(self->enable_fd, "0", sizeof("0")))
278 	ASSERT_EQ(0, self->check);
279 
280 	/* File still open should return -EBUSY for delete */
281 	ASSERT_EQ(-1, ioctl(self->data_fd, DIAG_IOCSDEL, "__test_event"));
282 	ASSERT_EQ(EBUSY, errno);
283 
284 	/* Unregister */
285 	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSUNREG, &unreg));
286 	unreg.disable_bit = 30;
287 	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSUNREG, &unreg));
288 
289 	/* Delete should have been auto-done after close and unregister */
290 	close(self->data_fd);
291 
292 	ASSERT_EQ(true, wait_for_delete());
293 }
294 
295 TEST_F(user, write_events) {
296 	struct user_reg reg = {0};
297 	struct iovec io[3];
298 	__u32 field1, field2;
299 	int before = 0, after = 0;
300 
301 	reg.size = sizeof(reg);
302 	reg.name_args = (__u64)"__test_event u32 field1; u32 field2";
303 	reg.enable_bit = 31;
304 	reg.enable_addr = (__u64)&self->check;
305 	reg.enable_size = sizeof(self->check);
306 
307 	field1 = 1;
308 	field2 = 2;
309 
310 	io[0].iov_base = &reg.write_index;
311 	io[0].iov_len = sizeof(reg.write_index);
312 	io[1].iov_base = &field1;
313 	io[1].iov_len = sizeof(field1);
314 	io[2].iov_base = &field2;
315 	io[2].iov_len = sizeof(field2);
316 
317 	/* Register should work */
318 	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
319 	ASSERT_EQ(0, reg.write_index);
320 	ASSERT_EQ(0, self->check);
321 
322 	/* Write should fail on invalid slot with ENOENT */
323 	io[0].iov_base = &field2;
324 	io[0].iov_len = sizeof(field2);
325 	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
326 	ASSERT_EQ(ENOENT, errno);
327 	io[0].iov_base = &reg.write_index;
328 	io[0].iov_len = sizeof(reg.write_index);
329 
330 	/* Write should return -EBADF when event is not enabled */
331 	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
332 	ASSERT_EQ(EBADF, errno);
333 
334 	/* Enable event */
335 	self->enable_fd = open(enable_file, O_RDWR);
336 	ASSERT_NE(-1, write(self->enable_fd, "1", sizeof("1")))
337 
338 	/* Event should now be enabled */
339 	ASSERT_NE(1 << reg.enable_bit, self->check);
340 
341 	/* Write should make it out to ftrace buffers */
342 	before = trace_bytes();
343 	ASSERT_NE(-1, writev(self->data_fd, (const struct iovec *)io, 3));
344 	after = trace_bytes();
345 	ASSERT_GT(after, before);
346 
347 	/* Negative index should fail with EINVAL */
348 	reg.write_index = -1;
349 	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
350 	ASSERT_EQ(EINVAL, errno);
351 }
352 
353 TEST_F(user, write_empty_events) {
354 	struct user_reg reg = {0};
355 	struct iovec io[1];
356 	int before = 0, after = 0;
357 
358 	reg.size = sizeof(reg);
359 	reg.name_args = (__u64)"__test_event";
360 	reg.enable_bit = 31;
361 	reg.enable_addr = (__u64)&self->check;
362 	reg.enable_size = sizeof(self->check);
363 
364 	io[0].iov_base = &reg.write_index;
365 	io[0].iov_len = sizeof(reg.write_index);
366 
367 	/* Register should work */
368 	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
369 	ASSERT_EQ(0, reg.write_index);
370 	ASSERT_EQ(0, self->check);
371 
372 	/* Enable event */
373 	self->enable_fd = open(enable_file, O_RDWR);
374 	ASSERT_NE(-1, write(self->enable_fd, "1", sizeof("1")))
375 
376 	/* Event should now be enabled */
377 	ASSERT_EQ(1 << reg.enable_bit, self->check);
378 
379 	/* Write should make it out to ftrace buffers */
380 	before = trace_bytes();
381 	ASSERT_NE(-1, writev(self->data_fd, (const struct iovec *)io, 1));
382 	after = trace_bytes();
383 	ASSERT_GT(after, before);
384 }
385 
386 TEST_F(user, write_fault) {
387 	struct user_reg reg = {0};
388 	struct iovec io[2];
389 	int l = sizeof(__u64);
390 	void *anon;
391 
392 	reg.size = sizeof(reg);
393 	reg.name_args = (__u64)"__test_event u64 anon";
394 	reg.enable_bit = 31;
395 	reg.enable_addr = (__u64)&self->check;
396 	reg.enable_size = sizeof(self->check);
397 
398 	anon = mmap(NULL, l, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
399 	ASSERT_NE(MAP_FAILED, anon);
400 
401 	io[0].iov_base = &reg.write_index;
402 	io[0].iov_len = sizeof(reg.write_index);
403 	io[1].iov_base = anon;
404 	io[1].iov_len = l;
405 
406 	/* Register should work */
407 	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
408 	ASSERT_EQ(0, reg.write_index);
409 
410 	/* Enable event */
411 	self->enable_fd = open(enable_file, O_RDWR);
412 	ASSERT_NE(-1, write(self->enable_fd, "1", sizeof("1")))
413 
414 	/* Write should work normally */
415 	ASSERT_NE(-1, writev(self->data_fd, (const struct iovec *)io, 2));
416 
417 	/* Faulted data should zero fill and work */
418 	ASSERT_EQ(0, madvise(anon, l, MADV_DONTNEED));
419 	ASSERT_NE(-1, writev(self->data_fd, (const struct iovec *)io, 2));
420 	ASSERT_EQ(0, munmap(anon, l));
421 }
422 
423 TEST_F(user, write_validator) {
424 	struct user_reg reg = {0};
425 	struct iovec io[3];
426 	int loc, bytes;
427 	char data[8];
428 	int before = 0, after = 0;
429 
430 	reg.size = sizeof(reg);
431 	reg.name_args = (__u64)"__test_event __rel_loc char[] data";
432 	reg.enable_bit = 31;
433 	reg.enable_addr = (__u64)&self->check;
434 	reg.enable_size = sizeof(self->check);
435 
436 	/* Register should work */
437 	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
438 	ASSERT_EQ(0, reg.write_index);
439 	ASSERT_EQ(0, self->check);
440 
441 	io[0].iov_base = &reg.write_index;
442 	io[0].iov_len = sizeof(reg.write_index);
443 	io[1].iov_base = &loc;
444 	io[1].iov_len = sizeof(loc);
445 	io[2].iov_base = data;
446 	bytes = snprintf(data, sizeof(data), "Test") + 1;
447 	io[2].iov_len = bytes;
448 
449 	/* Undersized write should fail */
450 	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 1));
451 	ASSERT_EQ(EINVAL, errno);
452 
453 	/* Enable event */
454 	self->enable_fd = open(enable_file, O_RDWR);
455 	ASSERT_NE(-1, write(self->enable_fd, "1", sizeof("1")))
456 
457 	/* Event should now be enabled */
458 	ASSERT_EQ(1 << reg.enable_bit, self->check);
459 
460 	/* Full in-bounds write should work */
461 	before = trace_bytes();
462 	loc = DYN_LOC(0, bytes);
463 	ASSERT_NE(-1, writev(self->data_fd, (const struct iovec *)io, 3));
464 	after = trace_bytes();
465 	ASSERT_GT(after, before);
466 
467 	/* Out of bounds write should fault (offset way out) */
468 	loc = DYN_LOC(1024, bytes);
469 	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
470 	ASSERT_EQ(EFAULT, errno);
471 
472 	/* Out of bounds write should fault (offset 1 byte out) */
473 	loc = DYN_LOC(1, bytes);
474 	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
475 	ASSERT_EQ(EFAULT, errno);
476 
477 	/* Out of bounds write should fault (size way out) */
478 	loc = DYN_LOC(0, bytes + 1024);
479 	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
480 	ASSERT_EQ(EFAULT, errno);
481 
482 	/* Out of bounds write should fault (size 1 byte out) */
483 	loc = DYN_LOC(0, bytes + 1);
484 	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
485 	ASSERT_EQ(EFAULT, errno);
486 
487 	/* Non-Null should fault */
488 	memset(data, 'A', sizeof(data));
489 	loc = DYN_LOC(0, bytes);
490 	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
491 	ASSERT_EQ(EFAULT, errno);
492 }
493 
494 TEST_F(user, print_fmt) {
495 	int ret;
496 
497 	ret = check_print_fmt("__test_event __rel_loc char[] data",
498 			      "print fmt: \"data=%s\", __get_rel_str(data)",
499 			      &self->check);
500 	ASSERT_EQ(0, ret);
501 
502 	ret = check_print_fmt("__test_event __data_loc char[] data",
503 			      "print fmt: \"data=%s\", __get_str(data)",
504 			      &self->check);
505 	ASSERT_EQ(0, ret);
506 
507 	ret = check_print_fmt("__test_event s64 data",
508 			      "print fmt: \"data=%lld\", REC->data",
509 			      &self->check);
510 	ASSERT_EQ(0, ret);
511 
512 	ret = check_print_fmt("__test_event u64 data",
513 			      "print fmt: \"data=%llu\", REC->data",
514 			      &self->check);
515 	ASSERT_EQ(0, ret);
516 
517 	ret = check_print_fmt("__test_event s32 data",
518 			      "print fmt: \"data=%d\", REC->data",
519 			      &self->check);
520 	ASSERT_EQ(0, ret);
521 
522 	ret = check_print_fmt("__test_event u32 data",
523 			      "print fmt: \"data=%u\", REC->data",
524 			      &self->check);
525 	ASSERT_EQ(0, ret);
526 
527 	ret = check_print_fmt("__test_event int data",
528 			      "print fmt: \"data=%d\", REC->data",
529 			      &self->check);
530 	ASSERT_EQ(0, ret);
531 
532 	ret = check_print_fmt("__test_event unsigned int data",
533 			      "print fmt: \"data=%u\", REC->data",
534 			      &self->check);
535 	ASSERT_EQ(0, ret);
536 
537 	ret = check_print_fmt("__test_event s16 data",
538 			      "print fmt: \"data=%d\", REC->data",
539 			      &self->check);
540 	ASSERT_EQ(0, ret);
541 
542 	ret = check_print_fmt("__test_event u16 data",
543 			      "print fmt: \"data=%u\", REC->data",
544 			      &self->check);
545 	ASSERT_EQ(0, ret);
546 
547 	ret = check_print_fmt("__test_event short data",
548 			      "print fmt: \"data=%d\", REC->data",
549 			      &self->check);
550 	ASSERT_EQ(0, ret);
551 
552 	ret = check_print_fmt("__test_event unsigned short data",
553 			      "print fmt: \"data=%u\", REC->data",
554 			      &self->check);
555 	ASSERT_EQ(0, ret);
556 
557 	ret = check_print_fmt("__test_event s8 data",
558 			      "print fmt: \"data=%d\", REC->data",
559 			      &self->check);
560 	ASSERT_EQ(0, ret);
561 
562 	ret = check_print_fmt("__test_event u8 data",
563 			      "print fmt: \"data=%u\", REC->data",
564 			      &self->check);
565 	ASSERT_EQ(0, ret);
566 
567 	ret = check_print_fmt("__test_event char data",
568 			      "print fmt: \"data=%d\", REC->data",
569 			      &self->check);
570 	ASSERT_EQ(0, ret);
571 
572 	ret = check_print_fmt("__test_event unsigned char data",
573 			      "print fmt: \"data=%u\", REC->data",
574 			      &self->check);
575 	ASSERT_EQ(0, ret);
576 
577 	ret = check_print_fmt("__test_event char[4] data",
578 			      "print fmt: \"data=%s\", REC->data",
579 			      &self->check);
580 	ASSERT_EQ(0, ret);
581 }
582 
583 int main(int argc, char **argv)
584 {
585 	return test_harness_run(argc, argv);
586 }
587