xref: /linux/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <unistd.h>
4 #include <pthread.h>
5 #include <test_progs.h>
6 #include "uprobe_multi.skel.h"
7 #include "uprobe_multi_bench.skel.h"
8 #include "uprobe_multi_usdt.skel.h"
9 #include "uprobe_multi_consumers.skel.h"
10 #include "uprobe_multi_pid_filter.skel.h"
11 #include "bpf/libbpf_internal.h"
12 #include "testing_helpers.h"
13 #include "../sdt.h"
14 
15 static char test_data[] = "test_data";
16 
17 noinline void uprobe_multi_func_1(void)
18 {
19 	asm volatile ("");
20 }
21 
22 noinline void uprobe_multi_func_2(void)
23 {
24 	asm volatile ("");
25 }
26 
27 noinline void uprobe_multi_func_3(void)
28 {
29 	asm volatile ("");
30 }
31 
32 noinline void usdt_trigger(void)
33 {
34 	STAP_PROBE(test, pid_filter_usdt);
35 }
36 
37 struct child {
38 	int go[2];
39 	int c2p[2]; /* child -> parent channel */
40 	int pid;
41 	int tid;
42 	pthread_t thread;
43 	char stack[65536];
44 };
45 
46 static void release_child(struct child *child)
47 {
48 	int child_status;
49 
50 	if (!child)
51 		return;
52 	close(child->go[1]);
53 	close(child->go[0]);
54 	if (child->thread)
55 		pthread_join(child->thread, NULL);
56 	close(child->c2p[0]);
57 	close(child->c2p[1]);
58 	if (child->pid > 0)
59 		waitpid(child->pid, &child_status, 0);
60 }
61 
62 static void kick_child(struct child *child)
63 {
64 	char c = 1;
65 
66 	if (child) {
67 		write(child->go[1], &c, 1);
68 		release_child(child);
69 	}
70 	fflush(NULL);
71 }
72 
73 static int child_func(void *arg)
74 {
75 	struct child *child = arg;
76 	int err, c;
77 
78 	close(child->go[1]);
79 
80 	/* wait for parent's kick */
81 	err = read(child->go[0], &c, 1);
82 	if (err != 1)
83 		exit(err);
84 
85 	uprobe_multi_func_1();
86 	uprobe_multi_func_2();
87 	uprobe_multi_func_3();
88 	usdt_trigger();
89 
90 	exit(errno);
91 }
92 
93 static int spawn_child_flag(struct child *child, bool clone_vm)
94 {
95 	/* pipe to notify child to execute the trigger functions */
96 	if (pipe(child->go))
97 		return -1;
98 
99 	if (clone_vm) {
100 		child->pid = child->tid = clone(child_func, child->stack + sizeof(child->stack)/2,
101 						CLONE_VM|SIGCHLD, child);
102 	} else {
103 		child->pid = child->tid = fork();
104 	}
105 	if (child->pid < 0) {
106 		release_child(child);
107 		errno = EINVAL;
108 		return -1;
109 	}
110 
111 	/* fork-ed child */
112 	if (!clone_vm && child->pid == 0)
113 		child_func(child);
114 
115 	return 0;
116 }
117 
118 static int spawn_child(struct child *child)
119 {
120 	return spawn_child_flag(child, false);
121 }
122 
123 static void *child_thread(void *ctx)
124 {
125 	struct child *child = ctx;
126 	int c = 0, err;
127 
128 	child->tid = syscall(SYS_gettid);
129 
130 	/* let parent know we are ready */
131 	err = write(child->c2p[1], &c, 1);
132 	if (err != 1)
133 		pthread_exit(&err);
134 
135 	/* wait for parent's kick */
136 	err = read(child->go[0], &c, 1);
137 	if (err != 1)
138 		pthread_exit(&err);
139 
140 	uprobe_multi_func_1();
141 	uprobe_multi_func_2();
142 	uprobe_multi_func_3();
143 	usdt_trigger();
144 
145 	err = 0;
146 	pthread_exit(&err);
147 }
148 
149 static int spawn_thread(struct child *child)
150 {
151 	int c, err;
152 
153 	/* pipe to notify child to execute the trigger functions */
154 	if (pipe(child->go))
155 		return -1;
156 	/* pipe to notify parent that child thread is ready */
157 	if (pipe(child->c2p)) {
158 		close(child->go[0]);
159 		close(child->go[1]);
160 		return -1;
161 	}
162 
163 	child->pid = getpid();
164 
165 	err = pthread_create(&child->thread, NULL, child_thread, child);
166 	if (err) {
167 		err = -errno;
168 		close(child->go[0]);
169 		close(child->go[1]);
170 		close(child->c2p[0]);
171 		close(child->c2p[1]);
172 		errno = -err;
173 		return -1;
174 	}
175 
176 	err = read(child->c2p[0], &c, 1);
177 	if (!ASSERT_EQ(err, 1, "child_thread_ready"))
178 		return -1;
179 
180 	return 0;
181 }
182 
183 static void uprobe_multi_test_run(struct uprobe_multi *skel, struct child *child)
184 {
185 	skel->bss->uprobe_multi_func_1_addr = (__u64) uprobe_multi_func_1;
186 	skel->bss->uprobe_multi_func_2_addr = (__u64) uprobe_multi_func_2;
187 	skel->bss->uprobe_multi_func_3_addr = (__u64) uprobe_multi_func_3;
188 
189 	skel->bss->user_ptr = test_data;
190 
191 	/*
192 	 * Disable pid check in bpf program if we are pid filter test,
193 	 * because the probe should be executed only by child->pid
194 	 * passed at the probe attach.
195 	 */
196 	skel->bss->pid = child ? 0 : getpid();
197 	skel->bss->expect_pid = child ? child->pid : 0;
198 
199 	/* trigger all probes, if we are testing child *process*, just to make
200 	 * sure that PID filtering doesn't let through activations from wrong
201 	 * PIDs; when we test child *thread*, we don't want to do this to
202 	 * avoid double counting number of triggering events
203 	 */
204 	if (!child || !child->thread) {
205 		uprobe_multi_func_1();
206 		uprobe_multi_func_2();
207 		uprobe_multi_func_3();
208 		usdt_trigger();
209 	}
210 
211 	if (child)
212 		kick_child(child);
213 
214 	/*
215 	 * There are 2 entry and 2 exit probe called for each uprobe_multi_func_[123]
216 	 * function and each sleepable probe (6) increments uprobe_multi_sleep_result.
217 	 */
218 	ASSERT_EQ(skel->bss->uprobe_multi_func_1_result, 2, "uprobe_multi_func_1_result");
219 	ASSERT_EQ(skel->bss->uprobe_multi_func_2_result, 2, "uprobe_multi_func_2_result");
220 	ASSERT_EQ(skel->bss->uprobe_multi_func_3_result, 2, "uprobe_multi_func_3_result");
221 
222 	ASSERT_EQ(skel->bss->uretprobe_multi_func_1_result, 2, "uretprobe_multi_func_1_result");
223 	ASSERT_EQ(skel->bss->uretprobe_multi_func_2_result, 2, "uretprobe_multi_func_2_result");
224 	ASSERT_EQ(skel->bss->uretprobe_multi_func_3_result, 2, "uretprobe_multi_func_3_result");
225 
226 	ASSERT_EQ(skel->bss->uprobe_multi_sleep_result, 6, "uprobe_multi_sleep_result");
227 
228 	ASSERT_FALSE(skel->bss->bad_pid_seen, "bad_pid_seen");
229 
230 	if (child) {
231 		ASSERT_EQ(skel->bss->child_pid, child->pid, "uprobe_multi_child_pid");
232 		ASSERT_EQ(skel->bss->child_tid, child->tid, "uprobe_multi_child_tid");
233 	}
234 }
235 
236 static void test_skel_api(void)
237 {
238 	struct uprobe_multi *skel = NULL;
239 	int err;
240 
241 	skel = uprobe_multi__open_and_load();
242 	if (!ASSERT_OK_PTR(skel, "uprobe_multi__open_and_load"))
243 		goto cleanup;
244 
245 	err = uprobe_multi__attach(skel);
246 	if (!ASSERT_OK(err, "uprobe_multi__attach"))
247 		goto cleanup;
248 
249 	uprobe_multi_test_run(skel, NULL);
250 
251 cleanup:
252 	uprobe_multi__destroy(skel);
253 }
254 
255 static void
256 __test_attach_api(const char *binary, const char *pattern, struct bpf_uprobe_multi_opts *opts,
257 		  struct child *child)
258 {
259 	pid_t pid = child ? child->pid : -1;
260 	struct uprobe_multi *skel = NULL;
261 
262 	skel = uprobe_multi__open_and_load();
263 	if (!ASSERT_OK_PTR(skel, "uprobe_multi__open_and_load"))
264 		goto cleanup;
265 
266 	opts->retprobe = false;
267 	skel->links.uprobe = bpf_program__attach_uprobe_multi(skel->progs.uprobe, pid,
268 							      binary, pattern, opts);
269 	if (!ASSERT_OK_PTR(skel->links.uprobe, "bpf_program__attach_uprobe_multi"))
270 		goto cleanup;
271 
272 	opts->retprobe = true;
273 	skel->links.uretprobe = bpf_program__attach_uprobe_multi(skel->progs.uretprobe, pid,
274 								 binary, pattern, opts);
275 	if (!ASSERT_OK_PTR(skel->links.uretprobe, "bpf_program__attach_uprobe_multi"))
276 		goto cleanup;
277 
278 	opts->retprobe = false;
279 	skel->links.uprobe_sleep = bpf_program__attach_uprobe_multi(skel->progs.uprobe_sleep, pid,
280 								    binary, pattern, opts);
281 	if (!ASSERT_OK_PTR(skel->links.uprobe_sleep, "bpf_program__attach_uprobe_multi"))
282 		goto cleanup;
283 
284 	opts->retprobe = true;
285 	skel->links.uretprobe_sleep = bpf_program__attach_uprobe_multi(skel->progs.uretprobe_sleep,
286 								       pid, binary, pattern, opts);
287 	if (!ASSERT_OK_PTR(skel->links.uretprobe_sleep, "bpf_program__attach_uprobe_multi"))
288 		goto cleanup;
289 
290 	opts->retprobe = false;
291 	skel->links.uprobe_extra = bpf_program__attach_uprobe_multi(skel->progs.uprobe_extra, -1,
292 								    binary, pattern, opts);
293 	if (!ASSERT_OK_PTR(skel->links.uprobe_extra, "bpf_program__attach_uprobe_multi"))
294 		goto cleanup;
295 
296 	/* Attach (uprobe-backed) USDTs */
297 	skel->links.usdt_pid = bpf_program__attach_usdt(skel->progs.usdt_pid, pid, binary,
298 							"test", "pid_filter_usdt", NULL);
299 	if (!ASSERT_OK_PTR(skel->links.usdt_pid, "attach_usdt_pid"))
300 		goto cleanup;
301 
302 	skel->links.usdt_extra = bpf_program__attach_usdt(skel->progs.usdt_extra, -1, binary,
303 							  "test", "pid_filter_usdt", NULL);
304 	if (!ASSERT_OK_PTR(skel->links.usdt_extra, "attach_usdt_extra"))
305 		goto cleanup;
306 
307 	uprobe_multi_test_run(skel, child);
308 
309 	ASSERT_FALSE(skel->bss->bad_pid_seen_usdt, "bad_pid_seen_usdt");
310 	if (child) {
311 		ASSERT_EQ(skel->bss->child_pid_usdt, child->pid, "usdt_multi_child_pid");
312 		ASSERT_EQ(skel->bss->child_tid_usdt, child->tid, "usdt_multi_child_tid");
313 	}
314 cleanup:
315 	uprobe_multi__destroy(skel);
316 }
317 
318 static void
319 test_attach_api(const char *binary, const char *pattern, struct bpf_uprobe_multi_opts *opts)
320 {
321 	static struct child child;
322 
323 	/* no pid filter */
324 	__test_attach_api(binary, pattern, opts, NULL);
325 
326 	/* pid filter */
327 	if (!ASSERT_OK(spawn_child(&child), "spawn_child"))
328 		return;
329 
330 	__test_attach_api(binary, pattern, opts, &child);
331 
332 	/* pid filter (thread) */
333 	if (!ASSERT_OK(spawn_thread(&child), "spawn_thread"))
334 		return;
335 
336 	__test_attach_api(binary, pattern, opts, &child);
337 }
338 
339 static void test_attach_api_pattern(void)
340 {
341 	LIBBPF_OPTS(bpf_uprobe_multi_opts, opts);
342 
343 	test_attach_api("/proc/self/exe", "uprobe_multi_func_*", &opts);
344 	test_attach_api("/proc/self/exe", "uprobe_multi_func_?", &opts);
345 }
346 
347 static void test_attach_api_syms(void)
348 {
349 	LIBBPF_OPTS(bpf_uprobe_multi_opts, opts);
350 	const char *syms[3] = {
351 		"uprobe_multi_func_1",
352 		"uprobe_multi_func_2",
353 		"uprobe_multi_func_3",
354 	};
355 
356 	opts.syms = syms;
357 	opts.cnt = ARRAY_SIZE(syms);
358 	test_attach_api("/proc/self/exe", NULL, &opts);
359 }
360 
361 static void test_attach_api_fails(void)
362 {
363 	LIBBPF_OPTS(bpf_link_create_opts, opts);
364 	const char *path = "/proc/self/exe";
365 	struct uprobe_multi *skel = NULL;
366 	int prog_fd, link_fd = -1;
367 	unsigned long offset = 0;
368 
369 	skel = uprobe_multi__open_and_load();
370 	if (!ASSERT_OK_PTR(skel, "uprobe_multi__open_and_load"))
371 		goto cleanup;
372 
373 	prog_fd = bpf_program__fd(skel->progs.uprobe_extra);
374 
375 	/* abnormal cnt */
376 	opts.uprobe_multi.path = path;
377 	opts.uprobe_multi.offsets = &offset;
378 	opts.uprobe_multi.cnt = INT_MAX;
379 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
380 	if (!ASSERT_ERR(link_fd, "link_fd"))
381 		goto cleanup;
382 	if (!ASSERT_EQ(link_fd, -E2BIG, "big cnt"))
383 		goto cleanup;
384 
385 	/* cnt is 0 */
386 	LIBBPF_OPTS_RESET(opts,
387 		.uprobe_multi.path = path,
388 		.uprobe_multi.offsets = (unsigned long *) &offset,
389 	);
390 
391 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
392 	if (!ASSERT_ERR(link_fd, "link_fd"))
393 		goto cleanup;
394 	if (!ASSERT_EQ(link_fd, -EINVAL, "cnt_is_zero"))
395 		goto cleanup;
396 
397 	/* negative offset */
398 	offset = -1;
399 	opts.uprobe_multi.path = path;
400 	opts.uprobe_multi.offsets = (unsigned long *) &offset;
401 	opts.uprobe_multi.cnt = 1;
402 
403 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
404 	if (!ASSERT_ERR(link_fd, "link_fd"))
405 		goto cleanup;
406 	if (!ASSERT_EQ(link_fd, -EINVAL, "offset_is_negative"))
407 		goto cleanup;
408 
409 	/* offsets is NULL */
410 	LIBBPF_OPTS_RESET(opts,
411 		.uprobe_multi.path = path,
412 		.uprobe_multi.cnt = 1,
413 	);
414 
415 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
416 	if (!ASSERT_ERR(link_fd, "link_fd"))
417 		goto cleanup;
418 	if (!ASSERT_EQ(link_fd, -EINVAL, "offsets_is_null"))
419 		goto cleanup;
420 
421 	/* wrong offsets pointer */
422 	LIBBPF_OPTS_RESET(opts,
423 		.uprobe_multi.path = path,
424 		.uprobe_multi.offsets = (unsigned long *) 1,
425 		.uprobe_multi.cnt = 1,
426 	);
427 
428 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
429 	if (!ASSERT_ERR(link_fd, "link_fd"))
430 		goto cleanup;
431 	if (!ASSERT_EQ(link_fd, -EFAULT, "offsets_is_wrong"))
432 		goto cleanup;
433 
434 	/* path is NULL */
435 	offset = 1;
436 	LIBBPF_OPTS_RESET(opts,
437 		.uprobe_multi.offsets = (unsigned long *) &offset,
438 		.uprobe_multi.cnt = 1,
439 	);
440 
441 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
442 	if (!ASSERT_ERR(link_fd, "link_fd"))
443 		goto cleanup;
444 	if (!ASSERT_EQ(link_fd, -EINVAL, "path_is_null"))
445 		goto cleanup;
446 
447 	/* wrong path pointer  */
448 	LIBBPF_OPTS_RESET(opts,
449 		.uprobe_multi.path = (const char *) 1,
450 		.uprobe_multi.offsets = (unsigned long *) &offset,
451 		.uprobe_multi.cnt = 1,
452 	);
453 
454 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
455 	if (!ASSERT_ERR(link_fd, "link_fd"))
456 		goto cleanup;
457 	if (!ASSERT_EQ(link_fd, -EFAULT, "path_is_wrong"))
458 		goto cleanup;
459 
460 	/* wrong path type */
461 	LIBBPF_OPTS_RESET(opts,
462 		.uprobe_multi.path = "/",
463 		.uprobe_multi.offsets = (unsigned long *) &offset,
464 		.uprobe_multi.cnt = 1,
465 	);
466 
467 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
468 	if (!ASSERT_ERR(link_fd, "link_fd"))
469 		goto cleanup;
470 	if (!ASSERT_EQ(link_fd, -EBADF, "path_is_wrong_type"))
471 		goto cleanup;
472 
473 	/* wrong cookies pointer */
474 	LIBBPF_OPTS_RESET(opts,
475 		.uprobe_multi.path = path,
476 		.uprobe_multi.offsets = (unsigned long *) &offset,
477 		.uprobe_multi.cookies = (__u64 *) 1ULL,
478 		.uprobe_multi.cnt = 1,
479 	);
480 
481 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
482 	if (!ASSERT_ERR(link_fd, "link_fd"))
483 		goto cleanup;
484 	if (!ASSERT_EQ(link_fd, -EFAULT, "cookies_is_wrong"))
485 		goto cleanup;
486 
487 	/* wrong ref_ctr_offsets pointer */
488 	LIBBPF_OPTS_RESET(opts,
489 		.uprobe_multi.path = path,
490 		.uprobe_multi.offsets = (unsigned long *) &offset,
491 		.uprobe_multi.cookies = (__u64 *) &offset,
492 		.uprobe_multi.ref_ctr_offsets = (unsigned long *) 1,
493 		.uprobe_multi.cnt = 1,
494 	);
495 
496 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
497 	if (!ASSERT_ERR(link_fd, "link_fd"))
498 		goto cleanup;
499 	if (!ASSERT_EQ(link_fd, -EFAULT, "ref_ctr_offsets_is_wrong"))
500 		goto cleanup;
501 
502 	/* wrong flags */
503 	LIBBPF_OPTS_RESET(opts,
504 		.uprobe_multi.flags = 1 << 31,
505 	);
506 
507 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
508 	if (!ASSERT_ERR(link_fd, "link_fd"))
509 		goto cleanup;
510 	if (!ASSERT_EQ(link_fd, -EINVAL, "wrong_flags"))
511 		goto cleanup;
512 
513 	/* wrong pid */
514 	LIBBPF_OPTS_RESET(opts,
515 		.uprobe_multi.path = path,
516 		.uprobe_multi.offsets = (unsigned long *) &offset,
517 		.uprobe_multi.cnt = 1,
518 		.uprobe_multi.pid = -2,
519 	);
520 
521 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
522 	if (!ASSERT_ERR(link_fd, "link_fd"))
523 		goto cleanup;
524 	ASSERT_EQ(link_fd, -EINVAL, "pid_is_wrong");
525 
526 cleanup:
527 	if (link_fd >= 0)
528 		close(link_fd);
529 	uprobe_multi__destroy(skel);
530 }
531 
532 #ifdef __x86_64__
533 noinline void uprobe_multi_error_func(void)
534 {
535 	/*
536 	 * If --fcf-protection=branch is enabled the gcc generates endbr as
537 	 * first instruction, so marking the exact address of int3 with the
538 	 * symbol to be used in the attach_uprobe_fail_trap test below.
539 	 */
540 	asm volatile (
541 		".globl uprobe_multi_error_func_int3;	\n"
542 		"uprobe_multi_error_func_int3:		\n"
543 		"int3					\n"
544 	);
545 }
546 
547 /*
548  * Attaching uprobe on uprobe_multi_error_func results in error
549  * because it already starts with int3 instruction.
550  */
551 static void attach_uprobe_fail_trap(struct uprobe_multi *skel)
552 {
553 	LIBBPF_OPTS(bpf_uprobe_multi_opts, opts);
554 	const char *syms[4] = {
555 		"uprobe_multi_func_1",
556 		"uprobe_multi_func_2",
557 		"uprobe_multi_func_3",
558 		"uprobe_multi_error_func_int3",
559 	};
560 
561 	opts.syms = syms;
562 	opts.cnt = ARRAY_SIZE(syms);
563 
564 	skel->links.uprobe = bpf_program__attach_uprobe_multi(skel->progs.uprobe, -1,
565 							      "/proc/self/exe", NULL, &opts);
566 	if (!ASSERT_ERR_PTR(skel->links.uprobe, "bpf_program__attach_uprobe_multi")) {
567 		bpf_link__destroy(skel->links.uprobe);
568 		skel->links.uprobe = NULL;
569 	}
570 }
571 #else
572 static void attach_uprobe_fail_trap(struct uprobe_multi *skel) { }
573 #endif
574 
575 short sema_1 __used, sema_2 __used;
576 
577 static void attach_uprobe_fail_refctr(struct uprobe_multi *skel)
578 {
579 	unsigned long *tmp_offsets = NULL, *tmp_ref_ctr_offsets = NULL;
580 	unsigned long offsets[3], ref_ctr_offsets[3];
581 	LIBBPF_OPTS(bpf_link_create_opts, opts);
582 	const char *path = "/proc/self/exe";
583 	const char *syms[3] = {
584 		"uprobe_multi_func_1",
585 		"uprobe_multi_func_2",
586 	};
587 	const char *sema[3] = {
588 		"sema_1",
589 		"sema_2",
590 	};
591 	int prog_fd, link_fd, err;
592 
593 	prog_fd = bpf_program__fd(skel->progs.uprobe_extra);
594 
595 	err = elf_resolve_syms_offsets("/proc/self/exe", 2, (const char **) &syms,
596 				       &tmp_offsets, STT_FUNC);
597 	if (!ASSERT_OK(err, "elf_resolve_syms_offsets_func"))
598 		return;
599 
600 	err = elf_resolve_syms_offsets("/proc/self/exe", 2, (const char **) &sema,
601 				       &tmp_ref_ctr_offsets, STT_OBJECT);
602 	if (!ASSERT_OK(err, "elf_resolve_syms_offsets_sema"))
603 		goto cleanup;
604 
605 	/*
606 	 * We attach to 3 uprobes on 2 functions, so 2 uprobes share single function,
607 	 * but with different ref_ctr_offset which is not allowed and results in fail.
608 	 */
609 	offsets[0] = tmp_offsets[0]; /* uprobe_multi_func_1 */
610 	offsets[1] = tmp_offsets[1]; /* uprobe_multi_func_2 */
611 	offsets[2] = tmp_offsets[1]; /* uprobe_multi_func_2 */
612 
613 	ref_ctr_offsets[0] = tmp_ref_ctr_offsets[0]; /* sema_1 */
614 	ref_ctr_offsets[1] = tmp_ref_ctr_offsets[1]; /* sema_2 */
615 	ref_ctr_offsets[2] = tmp_ref_ctr_offsets[0]; /* sema_1, error */
616 
617 	opts.uprobe_multi.path = path;
618 	opts.uprobe_multi.offsets = (const unsigned long *) &offsets;
619 	opts.uprobe_multi.ref_ctr_offsets = (const unsigned long *) &ref_ctr_offsets;
620 	opts.uprobe_multi.cnt = 3;
621 
622 	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
623 	if (!ASSERT_ERR(link_fd, "link_fd"))
624 		close(link_fd);
625 
626 cleanup:
627 	free(tmp_ref_ctr_offsets);
628 	free(tmp_offsets);
629 }
630 
631 static void test_attach_uprobe_fails(void)
632 {
633 	struct uprobe_multi *skel = NULL;
634 
635 	skel = uprobe_multi__open_and_load();
636 	if (!ASSERT_OK_PTR(skel, "uprobe_multi__open_and_load"))
637 		return;
638 
639 	/* attach fails due to adding uprobe on trap instruction, x86_64 only */
640 	attach_uprobe_fail_trap(skel);
641 
642 	/* attach fail due to wrong ref_ctr_offs on one of the uprobes */
643 	attach_uprobe_fail_refctr(skel);
644 
645 	uprobe_multi__destroy(skel);
646 }
647 
648 static void __test_link_api(struct child *child)
649 {
650 	int prog_fd, link1_fd = -1, link2_fd = -1, link3_fd = -1, link4_fd = -1;
651 	LIBBPF_OPTS(bpf_link_create_opts, opts);
652 	const char *path = "/proc/self/exe";
653 	struct uprobe_multi *skel = NULL;
654 	unsigned long *offsets = NULL;
655 	const char *syms[3] = {
656 		"uprobe_multi_func_1",
657 		"uprobe_multi_func_2",
658 		"uprobe_multi_func_3",
659 	};
660 	int link_extra_fd = -1;
661 	int err;
662 
663 	err = elf_resolve_syms_offsets(path, 3, syms, (unsigned long **) &offsets, STT_FUNC);
664 	if (!ASSERT_OK(err, "elf_resolve_syms_offsets"))
665 		return;
666 
667 	opts.uprobe_multi.path = path;
668 	opts.uprobe_multi.offsets = offsets;
669 	opts.uprobe_multi.cnt = ARRAY_SIZE(syms);
670 	opts.uprobe_multi.pid = child ? child->pid : 0;
671 
672 	skel = uprobe_multi__open_and_load();
673 	if (!ASSERT_OK_PTR(skel, "uprobe_multi__open_and_load"))
674 		goto cleanup;
675 
676 	opts.kprobe_multi.flags = 0;
677 	prog_fd = bpf_program__fd(skel->progs.uprobe);
678 	link1_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
679 	if (!ASSERT_GE(link1_fd, 0, "link1_fd"))
680 		goto cleanup;
681 
682 	opts.kprobe_multi.flags = BPF_F_UPROBE_MULTI_RETURN;
683 	prog_fd = bpf_program__fd(skel->progs.uretprobe);
684 	link2_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
685 	if (!ASSERT_GE(link2_fd, 0, "link2_fd"))
686 		goto cleanup;
687 
688 	opts.kprobe_multi.flags = 0;
689 	prog_fd = bpf_program__fd(skel->progs.uprobe_sleep);
690 	link3_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
691 	if (!ASSERT_GE(link3_fd, 0, "link3_fd"))
692 		goto cleanup;
693 
694 	opts.kprobe_multi.flags = BPF_F_UPROBE_MULTI_RETURN;
695 	prog_fd = bpf_program__fd(skel->progs.uretprobe_sleep);
696 	link4_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
697 	if (!ASSERT_GE(link4_fd, 0, "link4_fd"))
698 		goto cleanup;
699 
700 	opts.kprobe_multi.flags = 0;
701 	opts.uprobe_multi.pid = 0;
702 	prog_fd = bpf_program__fd(skel->progs.uprobe_extra);
703 	link_extra_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
704 	if (!ASSERT_GE(link_extra_fd, 0, "link_extra_fd"))
705 		goto cleanup;
706 
707 	uprobe_multi_test_run(skel, child);
708 
709 cleanup:
710 	if (link1_fd >= 0)
711 		close(link1_fd);
712 	if (link2_fd >= 0)
713 		close(link2_fd);
714 	if (link3_fd >= 0)
715 		close(link3_fd);
716 	if (link4_fd >= 0)
717 		close(link4_fd);
718 	if (link_extra_fd >= 0)
719 		close(link_extra_fd);
720 
721 	uprobe_multi__destroy(skel);
722 	free(offsets);
723 }
724 
725 static void test_link_api(void)
726 {
727 	static struct child child;
728 
729 	/* no pid filter */
730 	__test_link_api(NULL);
731 
732 	/* pid filter */
733 	if (!ASSERT_OK(spawn_child(&child), "spawn_child"))
734 		return;
735 
736 	__test_link_api(&child);
737 
738 	/* pid filter (thread) */
739 	if (!ASSERT_OK(spawn_thread(&child), "spawn_thread"))
740 		return;
741 
742 	__test_link_api(&child);
743 }
744 
745 static struct bpf_program *
746 get_program(struct uprobe_multi_consumers *skel, int prog)
747 {
748 	switch (prog) {
749 	case 0:
750 		return skel->progs.uprobe_0;
751 	case 1:
752 		return skel->progs.uprobe_1;
753 	case 2:
754 		return skel->progs.uprobe_2;
755 	case 3:
756 		return skel->progs.uprobe_3;
757 	default:
758 		ASSERT_FAIL("get_program");
759 		return NULL;
760 	}
761 }
762 
763 static struct bpf_link **
764 get_link(struct uprobe_multi_consumers *skel, int link)
765 {
766 	switch (link) {
767 	case 0:
768 		return &skel->links.uprobe_0;
769 	case 1:
770 		return &skel->links.uprobe_1;
771 	case 2:
772 		return &skel->links.uprobe_2;
773 	case 3:
774 		return &skel->links.uprobe_3;
775 	default:
776 		ASSERT_FAIL("get_link");
777 		return NULL;
778 	}
779 }
780 
781 static int uprobe_attach(struct uprobe_multi_consumers *skel, int idx)
782 {
783 	struct bpf_program *prog = get_program(skel, idx);
784 	struct bpf_link **link = get_link(skel, idx);
785 	LIBBPF_OPTS(bpf_uprobe_multi_opts, opts);
786 
787 	if (!prog || !link)
788 		return -1;
789 
790 	/*
791 	 * bit/prog: 0,1 uprobe entry
792 	 * bit/prog: 2,3 uprobe return
793 	 */
794 	opts.retprobe = idx == 2 || idx == 3;
795 
796 	*link = bpf_program__attach_uprobe_multi(prog, 0, "/proc/self/exe",
797 						"uprobe_consumer_test",
798 						&opts);
799 	if (!ASSERT_OK_PTR(*link, "bpf_program__attach_uprobe_multi"))
800 		return -1;
801 	return 0;
802 }
803 
804 static void uprobe_detach(struct uprobe_multi_consumers *skel, int idx)
805 {
806 	struct bpf_link **link = get_link(skel, idx);
807 
808 	bpf_link__destroy(*link);
809 	*link = NULL;
810 }
811 
812 static bool test_bit(int bit, unsigned long val)
813 {
814 	return val & (1 << bit);
815 }
816 
817 noinline int
818 uprobe_consumer_test(struct uprobe_multi_consumers *skel,
819 		     unsigned long before, unsigned long after)
820 {
821 	int idx;
822 
823 	/* detach uprobe for each unset programs in 'before' state ... */
824 	for (idx = 0; idx < 4; idx++) {
825 		if (test_bit(idx, before) && !test_bit(idx, after))
826 			uprobe_detach(skel, idx);
827 	}
828 
829 	/* ... and attach all new programs in 'after' state */
830 	for (idx = 0; idx < 4; idx++) {
831 		if (!test_bit(idx, before) && test_bit(idx, after)) {
832 			if (!ASSERT_OK(uprobe_attach(skel, idx), "uprobe_attach_after"))
833 				return -1;
834 		}
835 	}
836 	return 0;
837 }
838 
839 static void consumer_test(struct uprobe_multi_consumers *skel,
840 			  unsigned long before, unsigned long after)
841 {
842 	int err, idx;
843 
844 	printf("consumer_test before %lu after %lu\n", before, after);
845 
846 	/* 'before' is each, we attach uprobe for every set idx */
847 	for (idx = 0; idx < 4; idx++) {
848 		if (test_bit(idx, before)) {
849 			if (!ASSERT_OK(uprobe_attach(skel, idx), "uprobe_attach_before"))
850 				goto cleanup;
851 		}
852 	}
853 
854 	err = uprobe_consumer_test(skel, before, after);
855 	if (!ASSERT_EQ(err, 0, "uprobe_consumer_test"))
856 		goto cleanup;
857 
858 	for (idx = 0; idx < 4; idx++) {
859 		const char *fmt = "BUG";
860 		__u64 val = 0;
861 
862 		if (idx < 2) {
863 			/*
864 			 * uprobe entry
865 			 *   +1 if define in 'before'
866 			 */
867 			if (test_bit(idx, before))
868 				val++;
869 			fmt = "prog 0/1: uprobe";
870 		} else {
871 			/*
872 			 * uprobe return is tricky ;-)
873 			 *
874 			 * to trigger uretprobe consumer, the uretprobe needs to be installed,
875 			 * which means one of the 'return' uprobes was alive when probe was hit:
876 			 *
877 			 *   idxs: 2/3 uprobe return in 'installed' mask
878 			 *
879 			 * in addition if 'after' state removes everything that was installed in
880 			 * 'before' state, then uprobe kernel object goes away and return uprobe
881 			 * is not installed and we won't hit it even if it's in 'after' state.
882 			 */
883 			unsigned long had_uretprobes  = before & 0b1100; /* is uretprobe installed */
884 			unsigned long probe_preserved = before & after;  /* did uprobe go away */
885 
886 			if (had_uretprobes && probe_preserved && test_bit(idx, after))
887 				val++;
888 			fmt = "idx 2/3: uretprobe";
889 		}
890 
891 		ASSERT_EQ(skel->bss->uprobe_result[idx], val, fmt);
892 		skel->bss->uprobe_result[idx] = 0;
893 	}
894 
895 cleanup:
896 	for (idx = 0; idx < 4; idx++)
897 		uprobe_detach(skel, idx);
898 }
899 
900 static void test_consumers(void)
901 {
902 	struct uprobe_multi_consumers *skel;
903 	int before, after;
904 
905 	skel = uprobe_multi_consumers__open_and_load();
906 	if (!ASSERT_OK_PTR(skel, "uprobe_multi_consumers__open_and_load"))
907 		return;
908 
909 	/*
910 	 * The idea of this test is to try all possible combinations of
911 	 * uprobes consumers attached on single function.
912 	 *
913 	 *  - 2 uprobe entry consumer
914 	 *  - 2 uprobe exit consumers
915 	 *
916 	 * The test uses 4 uprobes attached on single function, but that
917 	 * translates into single uprobe with 4 consumers in kernel.
918 	 *
919 	 * The before/after values present the state of attached consumers
920 	 * before and after the probed function:
921 	 *
922 	 *  bit/prog 0,1 : uprobe entry
923 	 *  bit/prog 2,3 : uprobe return
924 	 *
925 	 * For example for:
926 	 *
927 	 *   before = 0b0101
928 	 *   after  = 0b0110
929 	 *
930 	 * it means that before we call 'uprobe_consumer_test' we attach
931 	 * uprobes defined in 'before' value:
932 	 *
933 	 *   - bit/prog 0: uprobe entry
934 	 *   - bit/prog 2: uprobe return
935 	 *
936 	 * uprobe_consumer_test is called and inside it we attach and detach
937 	 * uprobes based on 'after' value:
938 	 *
939 	 *   - bit/prog 0: stays untouched
940 	 *   - bit/prog 2: uprobe return is detached
941 	 *
942 	 * uprobe_consumer_test returns and we check counters values increased
943 	 * by bpf programs on each uprobe to match the expected count based on
944 	 * before/after bits.
945 	 */
946 
947 	for (before = 0; before < 16; before++) {
948 		for (after = 0; after < 16; after++)
949 			consumer_test(skel, before, after);
950 	}
951 
952 	uprobe_multi_consumers__destroy(skel);
953 }
954 
955 static struct bpf_program *uprobe_multi_program(struct uprobe_multi_pid_filter *skel, int idx)
956 {
957 	switch (idx) {
958 	case 0: return skel->progs.uprobe_multi_0;
959 	case 1: return skel->progs.uprobe_multi_1;
960 	case 2: return skel->progs.uprobe_multi_2;
961 	}
962 	return NULL;
963 }
964 
965 #define TASKS 3
966 
967 static void run_pid_filter(struct uprobe_multi_pid_filter *skel, bool clone_vm, bool retprobe)
968 {
969 	LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, .retprobe = retprobe);
970 	struct bpf_link *link[TASKS] = {};
971 	struct child child[TASKS] = {};
972 	int i;
973 
974 	memset(skel->bss->test, 0, sizeof(skel->bss->test));
975 
976 	for (i = 0; i < TASKS; i++) {
977 		if (!ASSERT_OK(spawn_child_flag(&child[i], clone_vm), "spawn_child"))
978 			goto cleanup;
979 		skel->bss->pids[i] = child[i].pid;
980 	}
981 
982 	for (i = 0; i < TASKS; i++) {
983 		link[i] = bpf_program__attach_uprobe_multi(uprobe_multi_program(skel, i),
984 							   child[i].pid, "/proc/self/exe",
985 							   "uprobe_multi_func_1", &opts);
986 		if (!ASSERT_OK_PTR(link[i], "bpf_program__attach_uprobe_multi"))
987 			goto cleanup;
988 	}
989 
990 	for (i = 0; i < TASKS; i++)
991 		kick_child(&child[i]);
992 
993 	for (i = 0; i < TASKS; i++) {
994 		ASSERT_EQ(skel->bss->test[i][0], 1, "pid");
995 		ASSERT_EQ(skel->bss->test[i][1], 0, "unknown");
996 	}
997 
998 cleanup:
999 	for (i = 0; i < TASKS; i++)
1000 		bpf_link__destroy(link[i]);
1001 	for (i = 0; i < TASKS; i++)
1002 		release_child(&child[i]);
1003 }
1004 
1005 static void test_pid_filter_process(bool clone_vm)
1006 {
1007 	struct uprobe_multi_pid_filter *skel;
1008 
1009 	skel = uprobe_multi_pid_filter__open_and_load();
1010 	if (!ASSERT_OK_PTR(skel, "uprobe_multi_pid_filter__open_and_load"))
1011 		return;
1012 
1013 	run_pid_filter(skel, clone_vm, false);
1014 	run_pid_filter(skel, clone_vm, true);
1015 
1016 	uprobe_multi_pid_filter__destroy(skel);
1017 }
1018 
1019 static void test_bench_attach_uprobe(void)
1020 {
1021 	long attach_start_ns = 0, attach_end_ns = 0;
1022 	struct uprobe_multi_bench *skel = NULL;
1023 	long detach_start_ns, detach_end_ns;
1024 	double attach_delta, detach_delta;
1025 	int err;
1026 
1027 	skel = uprobe_multi_bench__open_and_load();
1028 	if (!ASSERT_OK_PTR(skel, "uprobe_multi_bench__open_and_load"))
1029 		goto cleanup;
1030 
1031 	attach_start_ns = get_time_ns();
1032 
1033 	err = uprobe_multi_bench__attach(skel);
1034 	if (!ASSERT_OK(err, "uprobe_multi_bench__attach"))
1035 		goto cleanup;
1036 
1037 	attach_end_ns = get_time_ns();
1038 
1039 	system("./uprobe_multi bench");
1040 
1041 	ASSERT_EQ(skel->bss->count, 50000, "uprobes_count");
1042 
1043 cleanup:
1044 	detach_start_ns = get_time_ns();
1045 	uprobe_multi_bench__destroy(skel);
1046 	detach_end_ns = get_time_ns();
1047 
1048 	attach_delta = (attach_end_ns - attach_start_ns) / 1000000000.0;
1049 	detach_delta = (detach_end_ns - detach_start_ns) / 1000000000.0;
1050 
1051 	printf("%s: attached in %7.3lfs\n", __func__, attach_delta);
1052 	printf("%s: detached in %7.3lfs\n", __func__, detach_delta);
1053 }
1054 
1055 static void test_bench_attach_usdt(void)
1056 {
1057 	long attach_start_ns = 0, attach_end_ns = 0;
1058 	struct uprobe_multi_usdt *skel = NULL;
1059 	long detach_start_ns, detach_end_ns;
1060 	double attach_delta, detach_delta;
1061 
1062 	skel = uprobe_multi_usdt__open_and_load();
1063 	if (!ASSERT_OK_PTR(skel, "uprobe_multi__open"))
1064 		goto cleanup;
1065 
1066 	attach_start_ns = get_time_ns();
1067 
1068 	skel->links.usdt0 = bpf_program__attach_usdt(skel->progs.usdt0, -1, "./uprobe_multi",
1069 						     "test", "usdt", NULL);
1070 	if (!ASSERT_OK_PTR(skel->links.usdt0, "bpf_program__attach_usdt"))
1071 		goto cleanup;
1072 
1073 	attach_end_ns = get_time_ns();
1074 
1075 	system("./uprobe_multi usdt");
1076 
1077 	ASSERT_EQ(skel->bss->count, 50000, "usdt_count");
1078 
1079 cleanup:
1080 	detach_start_ns = get_time_ns();
1081 	uprobe_multi_usdt__destroy(skel);
1082 	detach_end_ns = get_time_ns();
1083 
1084 	attach_delta = (attach_end_ns - attach_start_ns) / 1000000000.0;
1085 	detach_delta = (detach_end_ns - detach_start_ns) / 1000000000.0;
1086 
1087 	printf("%s: attached in %7.3lfs\n", __func__, attach_delta);
1088 	printf("%s: detached in %7.3lfs\n", __func__, detach_delta);
1089 }
1090 
1091 void test_uprobe_multi_test(void)
1092 {
1093 	if (test__start_subtest("skel_api"))
1094 		test_skel_api();
1095 	if (test__start_subtest("attach_api_pattern"))
1096 		test_attach_api_pattern();
1097 	if (test__start_subtest("attach_api_syms"))
1098 		test_attach_api_syms();
1099 	if (test__start_subtest("link_api"))
1100 		test_link_api();
1101 	if (test__start_subtest("bench_uprobe"))
1102 		test_bench_attach_uprobe();
1103 	if (test__start_subtest("bench_usdt"))
1104 		test_bench_attach_usdt();
1105 	if (test__start_subtest("attach_api_fails"))
1106 		test_attach_api_fails();
1107 	if (test__start_subtest("attach_uprobe_fails"))
1108 		test_attach_uprobe_fails();
1109 	if (test__start_subtest("consumers"))
1110 		test_consumers();
1111 	if (test__start_subtest("filter_fork"))
1112 		test_pid_filter_process(false);
1113 	if (test__start_subtest("filter_clone_vm"))
1114 		test_pid_filter_process(true);
1115 }
1116