xref: /linux/tools/testing/selftests/bpf/prog_tests/fill_link_info.c (revision e78f70bad29c5ae1e1076698b690b15794e9b81e)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2023 Yafang Shao <laoar.shao@gmail.com> */
3 
4 #include <string.h>
5 #include <linux/bpf.h>
6 #include <linux/limits.h>
7 #include <test_progs.h>
8 #include "trace_helpers.h"
9 #include "test_fill_link_info.skel.h"
10 #include "bpf/libbpf_internal.h"
11 
12 #define TP_CAT "sched"
13 #define TP_NAME "sched_switch"
14 
15 static const char *kmulti_syms[] = {
16 	"bpf_fentry_test2",
17 	"bpf_fentry_test1",
18 	"bpf_fentry_test3",
19 };
20 #define KMULTI_CNT ARRAY_SIZE(kmulti_syms)
21 static __u64 kmulti_addrs[KMULTI_CNT];
22 static __u64 kmulti_cookies[] = { 3, 1, 2 };
23 
24 #define KPROBE_FUNC "bpf_fentry_test1"
25 static __u64 kprobe_addr;
26 
27 #define UPROBE_FILE "/proc/self/exe"
28 static ssize_t uprobe_offset;
29 /* uprobe attach point */
30 static noinline void uprobe_func(void)
31 {
32 	asm volatile ("");
33 }
34 
35 #define PERF_EVENT_COOKIE 0xdeadbeef
36 
37 static int verify_perf_link_info(int fd, enum bpf_perf_event_type type, long addr,
38 				 ssize_t offset, ssize_t entry_offset)
39 {
40 	ssize_t ref_ctr_offset = entry_offset /* ref_ctr_offset for uprobes */;
41 	struct bpf_link_info info;
42 	__u32 len = sizeof(info);
43 	char buf[PATH_MAX];
44 	int err;
45 
46 	memset(&info, 0, sizeof(info));
47 	buf[0] = '\0';
48 
49 again:
50 	err = bpf_link_get_info_by_fd(fd, &info, &len);
51 	if (!ASSERT_OK(err, "get_link_info"))
52 		return -1;
53 
54 	if (!ASSERT_EQ(info.type, BPF_LINK_TYPE_PERF_EVENT, "link_type"))
55 		return -1;
56 	if (!ASSERT_EQ(info.perf_event.type, type, "perf_type_match"))
57 		return -1;
58 
59 	switch (info.perf_event.type) {
60 	case BPF_PERF_EVENT_KPROBE:
61 	case BPF_PERF_EVENT_KRETPROBE:
62 		ASSERT_EQ(info.perf_event.kprobe.offset, offset, "kprobe_offset");
63 
64 		/* In case kernel.kptr_restrict is not permitted or MAX_SYMS is reached */
65 		if (addr)
66 			ASSERT_EQ(info.perf_event.kprobe.addr, addr + entry_offset,
67 				  "kprobe_addr");
68 
69 		ASSERT_EQ(info.perf_event.kprobe.cookie, PERF_EVENT_COOKIE, "kprobe_cookie");
70 
71 		ASSERT_EQ(info.perf_event.kprobe.name_len, strlen(KPROBE_FUNC) + 1,
72 				  "name_len");
73 		if (!info.perf_event.kprobe.func_name) {
74 			info.perf_event.kprobe.func_name = ptr_to_u64(&buf);
75 			info.perf_event.kprobe.name_len = sizeof(buf);
76 			goto again;
77 		}
78 
79 		err = strncmp(u64_to_ptr(info.perf_event.kprobe.func_name), KPROBE_FUNC,
80 			      strlen(KPROBE_FUNC));
81 		ASSERT_EQ(err, 0, "cmp_kprobe_func_name");
82 		break;
83 	case BPF_PERF_EVENT_TRACEPOINT:
84 		ASSERT_EQ(info.perf_event.tracepoint.name_len, strlen(TP_NAME) + 1,
85 				  "name_len");
86 		if (!info.perf_event.tracepoint.tp_name) {
87 			info.perf_event.tracepoint.tp_name = ptr_to_u64(&buf);
88 			info.perf_event.tracepoint.name_len = sizeof(buf);
89 			goto again;
90 		}
91 
92 		ASSERT_EQ(info.perf_event.tracepoint.cookie, PERF_EVENT_COOKIE, "tracepoint_cookie");
93 
94 		err = strncmp(u64_to_ptr(info.perf_event.tracepoint.tp_name), TP_NAME,
95 			      strlen(TP_NAME));
96 		ASSERT_EQ(err, 0, "cmp_tp_name");
97 		break;
98 	case BPF_PERF_EVENT_UPROBE:
99 	case BPF_PERF_EVENT_URETPROBE:
100 		ASSERT_EQ(info.perf_event.uprobe.offset, offset, "uprobe_offset");
101 		ASSERT_EQ(info.perf_event.uprobe.ref_ctr_offset, ref_ctr_offset, "uprobe_ref_ctr_offset");
102 
103 		ASSERT_EQ(info.perf_event.uprobe.name_len, strlen(UPROBE_FILE) + 1,
104 				  "name_len");
105 		if (!info.perf_event.uprobe.file_name) {
106 			info.perf_event.uprobe.file_name = ptr_to_u64(&buf);
107 			info.perf_event.uprobe.name_len = sizeof(buf);
108 			goto again;
109 		}
110 
111 		ASSERT_EQ(info.perf_event.uprobe.cookie, PERF_EVENT_COOKIE, "uprobe_cookie");
112 
113 		err = strncmp(u64_to_ptr(info.perf_event.uprobe.file_name), UPROBE_FILE,
114 			      strlen(UPROBE_FILE));
115 			ASSERT_EQ(err, 0, "cmp_file_name");
116 		break;
117 	case BPF_PERF_EVENT_EVENT:
118 		ASSERT_EQ(info.perf_event.event.type, PERF_TYPE_SOFTWARE, "event_type");
119 		ASSERT_EQ(info.perf_event.event.config, PERF_COUNT_SW_PAGE_FAULTS, "event_config");
120 		ASSERT_EQ(info.perf_event.event.cookie, PERF_EVENT_COOKIE, "event_cookie");
121 		break;
122 	default:
123 		err = -1;
124 		break;
125 	}
126 	return err;
127 }
128 
129 static void kprobe_fill_invalid_user_buffer(int fd)
130 {
131 	struct bpf_link_info info;
132 	__u32 len = sizeof(info);
133 	int err;
134 
135 	memset(&info, 0, sizeof(info));
136 
137 	info.perf_event.kprobe.func_name = 0x1; /* invalid address */
138 	err = bpf_link_get_info_by_fd(fd, &info, &len);
139 	ASSERT_EQ(err, -EINVAL, "invalid_buff_and_len");
140 
141 	info.perf_event.kprobe.name_len = 64;
142 	err = bpf_link_get_info_by_fd(fd, &info, &len);
143 	ASSERT_EQ(err, -EFAULT, "invalid_buff");
144 
145 	info.perf_event.kprobe.func_name = 0;
146 	err = bpf_link_get_info_by_fd(fd, &info, &len);
147 	ASSERT_EQ(err, -EINVAL, "invalid_len");
148 
149 	ASSERT_EQ(info.perf_event.kprobe.addr, 0, "func_addr");
150 	ASSERT_EQ(info.perf_event.kprobe.offset, 0, "func_offset");
151 	ASSERT_EQ(info.perf_event.type, 0, "type");
152 }
153 
154 static void test_kprobe_fill_link_info(struct test_fill_link_info *skel,
155 				       enum bpf_perf_event_type type,
156 				       bool invalid)
157 {
158 	DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts,
159 		.attach_mode = PROBE_ATTACH_MODE_LINK,
160 		.retprobe = type == BPF_PERF_EVENT_KRETPROBE,
161 		.bpf_cookie = PERF_EVENT_COOKIE,
162 	);
163 	ssize_t entry_offset = 0;
164 	struct bpf_link *link;
165 	int link_fd, err;
166 
167 	link = bpf_program__attach_kprobe_opts(skel->progs.kprobe_run, KPROBE_FUNC, &opts);
168 	if (!ASSERT_OK_PTR(link, "attach_kprobe"))
169 		return;
170 
171 	link_fd = bpf_link__fd(link);
172 	if (!invalid) {
173 		/* See also arch_adjust_kprobe_addr(). */
174 		if (skel->kconfig->CONFIG_X86_KERNEL_IBT)
175 			entry_offset = 4;
176 		if (skel->kconfig->CONFIG_PPC64 &&
177 		    skel->kconfig->CONFIG_KPROBES_ON_FTRACE &&
178 		    !skel->kconfig->CONFIG_PPC_FTRACE_OUT_OF_LINE)
179 			entry_offset = 4;
180 		err = verify_perf_link_info(link_fd, type, kprobe_addr, 0, entry_offset);
181 		ASSERT_OK(err, "verify_perf_link_info");
182 	} else {
183 		kprobe_fill_invalid_user_buffer(link_fd);
184 	}
185 	bpf_link__destroy(link);
186 }
187 
188 static void test_tp_fill_link_info(struct test_fill_link_info *skel)
189 {
190 	DECLARE_LIBBPF_OPTS(bpf_tracepoint_opts, opts,
191 		.bpf_cookie = PERF_EVENT_COOKIE,
192 	);
193 	struct bpf_link *link;
194 	int link_fd, err;
195 
196 	link = bpf_program__attach_tracepoint_opts(skel->progs.tp_run, TP_CAT, TP_NAME, &opts);
197 	if (!ASSERT_OK_PTR(link, "attach_tp"))
198 		return;
199 
200 	link_fd = bpf_link__fd(link);
201 	err = verify_perf_link_info(link_fd, BPF_PERF_EVENT_TRACEPOINT, 0, 0, 0);
202 	ASSERT_OK(err, "verify_perf_link_info");
203 	bpf_link__destroy(link);
204 }
205 
206 static void test_event_fill_link_info(struct test_fill_link_info *skel)
207 {
208 	DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, opts,
209 		.bpf_cookie = PERF_EVENT_COOKIE,
210 	);
211 	struct bpf_link *link;
212 	int link_fd, err, pfd;
213 	struct perf_event_attr attr = {
214 		.type = PERF_TYPE_SOFTWARE,
215 		.config = PERF_COUNT_SW_PAGE_FAULTS,
216 		.freq = 1,
217 		.sample_freq = 1,
218 		.size = sizeof(struct perf_event_attr),
219 	};
220 
221 	pfd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, 0 /* cpu 0 */,
222 		      -1 /* group id */, 0 /* flags */);
223 	if (!ASSERT_GE(pfd, 0, "perf_event_open"))
224 		return;
225 
226 	link = bpf_program__attach_perf_event_opts(skel->progs.event_run, pfd, &opts);
227 	if (!ASSERT_OK_PTR(link, "attach_event"))
228 		goto error;
229 
230 	link_fd = bpf_link__fd(link);
231 	err = verify_perf_link_info(link_fd, BPF_PERF_EVENT_EVENT, 0, 0, 0);
232 	ASSERT_OK(err, "verify_perf_link_info");
233 	bpf_link__destroy(link);
234 
235 error:
236 	close(pfd);
237 }
238 
239 static void test_uprobe_fill_link_info(struct test_fill_link_info *skel,
240 				       enum bpf_perf_event_type type)
241 {
242 	DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts,
243 		.retprobe = type == BPF_PERF_EVENT_URETPROBE,
244 		.bpf_cookie = PERF_EVENT_COOKIE,
245 	);
246 	const char *sema[1] = {
247 		"uprobe_link_info_sema_1",
248 	};
249 	__u64 *ref_ctr_offset;
250 	struct bpf_link *link;
251 	int link_fd, err;
252 
253 	err = elf_resolve_syms_offsets("/proc/self/exe", 1, sema,
254 				       (unsigned long **) &ref_ctr_offset, STT_OBJECT);
255 	if (!ASSERT_OK(err, "elf_resolve_syms_offsets_object"))
256 		return;
257 
258 	opts.ref_ctr_offset = *ref_ctr_offset;
259 	link = bpf_program__attach_uprobe_opts(skel->progs.uprobe_run,
260 					       0, /* self pid */
261 					       UPROBE_FILE, uprobe_offset,
262 					       &opts);
263 	if (!ASSERT_OK_PTR(link, "attach_uprobe"))
264 		goto out;
265 
266 	link_fd = bpf_link__fd(link);
267 	err = verify_perf_link_info(link_fd, type, 0, uprobe_offset, *ref_ctr_offset);
268 	ASSERT_OK(err, "verify_perf_link_info");
269 	bpf_link__destroy(link);
270 out:
271 	free(ref_ctr_offset);
272 }
273 
274 static int verify_kmulti_link_info(int fd, bool retprobe, bool has_cookies)
275 {
276 	__u64 addrs[KMULTI_CNT], cookies[KMULTI_CNT];
277 	struct bpf_link_info info;
278 	__u32 len = sizeof(info);
279 	int flags, i, err;
280 
281 	memset(&info, 0, sizeof(info));
282 
283 again:
284 	err = bpf_link_get_info_by_fd(fd, &info, &len);
285 	if (!ASSERT_OK(err, "get_link_info"))
286 		return -1;
287 
288 	if (!ASSERT_EQ(info.type, BPF_LINK_TYPE_KPROBE_MULTI, "kmulti_type"))
289 		return -1;
290 
291 	ASSERT_EQ(info.kprobe_multi.count, KMULTI_CNT, "func_cnt");
292 	flags = info.kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN;
293 	if (!retprobe)
294 		ASSERT_EQ(flags, 0, "kmulti_flags");
295 	else
296 		ASSERT_NEQ(flags, 0, "kretmulti_flags");
297 
298 	if (!info.kprobe_multi.addrs) {
299 		info.kprobe_multi.addrs = ptr_to_u64(addrs);
300 		info.kprobe_multi.cookies = ptr_to_u64(cookies);
301 		goto again;
302 	}
303 	for (i = 0; i < KMULTI_CNT; i++) {
304 		ASSERT_EQ(addrs[i], kmulti_addrs[i], "kmulti_addrs");
305 		ASSERT_EQ(cookies[i], has_cookies ? kmulti_cookies[i] : 0,
306 			  "kmulti_cookies_value");
307 	}
308 	return 0;
309 }
310 
311 static void verify_kmulti_invalid_user_buffer(int fd)
312 {
313 	__u64 addrs[KMULTI_CNT], cookies[KMULTI_CNT];
314 	struct bpf_link_info info;
315 	__u32 len = sizeof(info);
316 	int err, i;
317 
318 	memset(&info, 0, sizeof(info));
319 
320 	info.kprobe_multi.count = KMULTI_CNT;
321 	err = bpf_link_get_info_by_fd(fd, &info, &len);
322 	ASSERT_EQ(err, -EINVAL, "no_addr");
323 
324 	info.kprobe_multi.addrs = ptr_to_u64(addrs);
325 	info.kprobe_multi.count = 0;
326 	err = bpf_link_get_info_by_fd(fd, &info, &len);
327 	ASSERT_EQ(err, -EINVAL, "no_cnt");
328 
329 	for (i = 0; i < KMULTI_CNT; i++)
330 		addrs[i] = 0;
331 	info.kprobe_multi.count = KMULTI_CNT - 1;
332 	err = bpf_link_get_info_by_fd(fd, &info, &len);
333 	ASSERT_EQ(err, -ENOSPC, "smaller_cnt");
334 	for (i = 0; i < KMULTI_CNT - 1; i++)
335 		ASSERT_EQ(addrs[i], kmulti_addrs[i], "kmulti_addrs");
336 	ASSERT_EQ(addrs[i], 0, "kmulti_addrs");
337 
338 	for (i = 0; i < KMULTI_CNT; i++)
339 		addrs[i] = 0;
340 	info.kprobe_multi.count = KMULTI_CNT + 1;
341 	err = bpf_link_get_info_by_fd(fd, &info, &len);
342 	ASSERT_EQ(err, 0, "bigger_cnt");
343 	for (i = 0; i < KMULTI_CNT; i++)
344 		ASSERT_EQ(addrs[i], kmulti_addrs[i], "kmulti_addrs");
345 
346 	info.kprobe_multi.count = KMULTI_CNT;
347 	info.kprobe_multi.addrs = 0x1; /* invalid addr */
348 	err = bpf_link_get_info_by_fd(fd, &info, &len);
349 	ASSERT_EQ(err, -EFAULT, "invalid_buff_addrs");
350 
351 	info.kprobe_multi.count = KMULTI_CNT;
352 	info.kprobe_multi.addrs = ptr_to_u64(addrs);
353 	info.kprobe_multi.cookies = 0x1; /* invalid addr */
354 	err = bpf_link_get_info_by_fd(fd, &info, &len);
355 	ASSERT_EQ(err, -EFAULT, "invalid_buff_cookies");
356 
357 	/* cookies && !count */
358 	info.kprobe_multi.count = 0;
359 	info.kprobe_multi.addrs = ptr_to_u64(NULL);
360 	info.kprobe_multi.cookies = ptr_to_u64(cookies);
361 	err = bpf_link_get_info_by_fd(fd, &info, &len);
362 	ASSERT_EQ(err, -EINVAL, "invalid_cookies_count");
363 }
364 
365 static int symbols_cmp_r(const void *a, const void *b)
366 {
367 	const char **str_a = (const char **) a;
368 	const char **str_b = (const char **) b;
369 
370 	return strcmp(*str_a, *str_b);
371 }
372 
373 static void test_kprobe_multi_fill_link_info(struct test_fill_link_info *skel,
374 					     bool retprobe, bool cookies,
375 					     bool invalid)
376 {
377 	LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
378 	struct bpf_link *link;
379 	int link_fd, err;
380 
381 	opts.syms = kmulti_syms;
382 	opts.cookies = cookies ? kmulti_cookies : NULL;
383 	opts.cnt = KMULTI_CNT;
384 	opts.retprobe = retprobe;
385 	link = bpf_program__attach_kprobe_multi_opts(skel->progs.kmulti_run, NULL, &opts);
386 	if (!ASSERT_OK_PTR(link, "attach_kprobe_multi"))
387 		return;
388 
389 	link_fd = bpf_link__fd(link);
390 	if (!invalid) {
391 		err = verify_kmulti_link_info(link_fd, retprobe, cookies);
392 		ASSERT_OK(err, "verify_kmulti_link_info");
393 	} else {
394 		verify_kmulti_invalid_user_buffer(link_fd);
395 	}
396 	bpf_link__destroy(link);
397 }
398 
399 #define SEC(name) __attribute__((section(name), used))
400 
401 static short uprobe_link_info_sema_1 SEC(".probes");
402 static short uprobe_link_info_sema_2 SEC(".probes");
403 static short uprobe_link_info_sema_3 SEC(".probes");
404 
405 noinline void uprobe_link_info_func_1(void)
406 {
407 	asm volatile ("");
408 	uprobe_link_info_sema_1++;
409 }
410 
411 noinline void uprobe_link_info_func_2(void)
412 {
413 	asm volatile ("");
414 	uprobe_link_info_sema_2++;
415 }
416 
417 noinline void uprobe_link_info_func_3(void)
418 {
419 	asm volatile ("");
420 	uprobe_link_info_sema_3++;
421 }
422 
423 static int
424 verify_umulti_link_info(int fd, bool retprobe, __u64 *offsets,
425 			__u64 *cookies, __u64 *ref_ctr_offsets)
426 {
427 	char path[PATH_MAX], path_buf[PATH_MAX];
428 	struct bpf_link_info info;
429 	__u32 len = sizeof(info);
430 	__u64 ref_ctr_offsets_buf[3];
431 	__u64 offsets_buf[3];
432 	__u64 cookies_buf[3];
433 	int i, err, bit;
434 	__u32 count = 0;
435 
436 	memset(path, 0, sizeof(path));
437 	err = readlink("/proc/self/exe", path, sizeof(path));
438 	if (!ASSERT_NEQ(err, -1, "readlink"))
439 		return -1;
440 
441 	memset(&info, 0, sizeof(info));
442 	err = bpf_link_get_info_by_fd(fd, &info, &len);
443 	if (!ASSERT_OK(err, "bpf_link_get_info_by_fd"))
444 		return -1;
445 
446 	ASSERT_EQ(info.uprobe_multi.count, 3, "info.uprobe_multi.count");
447 	ASSERT_EQ(info.uprobe_multi.path_size, strlen(path) + 1,
448 		  "info.uprobe_multi.path_size");
449 
450 	for (bit = 0; bit < 8; bit++) {
451 		memset(&info, 0, sizeof(info));
452 		info.uprobe_multi.path = ptr_to_u64(path_buf);
453 		info.uprobe_multi.path_size = sizeof(path_buf);
454 		info.uprobe_multi.count = count;
455 
456 		if (bit & 0x1)
457 			info.uprobe_multi.offsets = ptr_to_u64(offsets_buf);
458 		if (bit & 0x2)
459 			info.uprobe_multi.cookies = ptr_to_u64(cookies_buf);
460 		if (bit & 0x4)
461 			info.uprobe_multi.ref_ctr_offsets = ptr_to_u64(ref_ctr_offsets_buf);
462 
463 		err = bpf_link_get_info_by_fd(fd, &info, &len);
464 		if (!ASSERT_OK(err, "bpf_link_get_info_by_fd"))
465 			return -1;
466 
467 		if (!ASSERT_EQ(info.type, BPF_LINK_TYPE_UPROBE_MULTI, "info.type"))
468 			return -1;
469 
470 		ASSERT_EQ(info.uprobe_multi.pid, getpid(), "info.uprobe_multi.pid");
471 		ASSERT_EQ(info.uprobe_multi.count, 3, "info.uprobe_multi.count");
472 		ASSERT_EQ(info.uprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN,
473 			  retprobe, "info.uprobe_multi.flags.retprobe");
474 		ASSERT_EQ(info.uprobe_multi.path_size, strlen(path) + 1, "info.uprobe_multi.path_size");
475 		ASSERT_STREQ(path_buf, path, "info.uprobe_multi.path");
476 
477 		for (i = 0; i < info.uprobe_multi.count; i++) {
478 			if (info.uprobe_multi.offsets)
479 				ASSERT_EQ(offsets_buf[i], offsets[i], "info.uprobe_multi.offsets");
480 			if (info.uprobe_multi.cookies)
481 				ASSERT_EQ(cookies_buf[i], cookies[i], "info.uprobe_multi.cookies");
482 			if (info.uprobe_multi.ref_ctr_offsets) {
483 				ASSERT_EQ(ref_ctr_offsets_buf[i], ref_ctr_offsets[i],
484 					  "info.uprobe_multi.ref_ctr_offsets");
485 			}
486 		}
487 		count = count ?: info.uprobe_multi.count;
488 	}
489 
490 	return 0;
491 }
492 
493 static void verify_umulti_invalid_user_buffer(int fd)
494 {
495 	struct bpf_link_info info;
496 	__u32 len = sizeof(info);
497 	__u64 buf[3];
498 	int err;
499 
500 	/* upath_size defined, not path */
501 	memset(&info, 0, sizeof(info));
502 	info.uprobe_multi.path_size = 3;
503 	err = bpf_link_get_info_by_fd(fd, &info, &len);
504 	ASSERT_EQ(err, -EINVAL, "failed_upath_size");
505 
506 	/* path defined, but small */
507 	memset(&info, 0, sizeof(info));
508 	info.uprobe_multi.path = ptr_to_u64(buf);
509 	info.uprobe_multi.path_size = 3;
510 	err = bpf_link_get_info_by_fd(fd, &info, &len);
511 	ASSERT_LT(err, 0, "failed_upath_small");
512 
513 	/* path has wrong pointer */
514 	memset(&info, 0, sizeof(info));
515 	info.uprobe_multi.path_size = PATH_MAX;
516 	info.uprobe_multi.path = 123;
517 	err = bpf_link_get_info_by_fd(fd, &info, &len);
518 	ASSERT_EQ(err, -EFAULT, "failed_bad_path_ptr");
519 
520 	/* count zero, with offsets */
521 	memset(&info, 0, sizeof(info));
522 	info.uprobe_multi.offsets = ptr_to_u64(buf);
523 	err = bpf_link_get_info_by_fd(fd, &info, &len);
524 	ASSERT_EQ(err, -EINVAL, "failed_count");
525 
526 	/* offsets not big enough */
527 	memset(&info, 0, sizeof(info));
528 	info.uprobe_multi.offsets = ptr_to_u64(buf);
529 	info.uprobe_multi.count = 2;
530 	err = bpf_link_get_info_by_fd(fd, &info, &len);
531 	ASSERT_EQ(err, -ENOSPC, "failed_small_count");
532 
533 	/* offsets has wrong pointer */
534 	memset(&info, 0, sizeof(info));
535 	info.uprobe_multi.offsets = 123;
536 	info.uprobe_multi.count = 3;
537 	err = bpf_link_get_info_by_fd(fd, &info, &len);
538 	ASSERT_EQ(err, -EFAULT, "failed_wrong_offsets");
539 }
540 
541 static void test_uprobe_multi_fill_link_info(struct test_fill_link_info *skel,
542 					     bool retprobe, bool invalid)
543 {
544 	LIBBPF_OPTS(bpf_uprobe_multi_opts, opts,
545 		.retprobe = retprobe,
546 	);
547 	const char *syms[3] = {
548 		"uprobe_link_info_func_1",
549 		"uprobe_link_info_func_2",
550 		"uprobe_link_info_func_3",
551 	};
552 	__u64 cookies[3] = {
553 		0xdead,
554 		0xbeef,
555 		0xcafe,
556 	};
557 	const char *sema[3] = {
558 		"uprobe_link_info_sema_1",
559 		"uprobe_link_info_sema_2",
560 		"uprobe_link_info_sema_3",
561 	};
562 	__u64 *offsets = NULL, *ref_ctr_offsets;
563 	struct bpf_link *link;
564 	int link_fd, err;
565 
566 	err = elf_resolve_syms_offsets("/proc/self/exe", 3, sema,
567 				       (unsigned long **) &ref_ctr_offsets, STT_OBJECT);
568 	if (!ASSERT_OK(err, "elf_resolve_syms_offsets_object"))
569 		return;
570 
571 	err = elf_resolve_syms_offsets("/proc/self/exe", 3, syms,
572 				       (unsigned long **) &offsets, STT_FUNC);
573 	if (!ASSERT_OK(err, "elf_resolve_syms_offsets_func"))
574 		goto out;
575 
576 	opts.syms = syms;
577 	opts.cookies = &cookies[0];
578 	opts.ref_ctr_offsets = (unsigned long *) &ref_ctr_offsets[0];
579 	opts.cnt = ARRAY_SIZE(syms);
580 
581 	link = bpf_program__attach_uprobe_multi(skel->progs.umulti_run, 0,
582 						"/proc/self/exe", NULL, &opts);
583 	if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_multi"))
584 		goto out;
585 
586 	link_fd = bpf_link__fd(link);
587 	if (invalid)
588 		verify_umulti_invalid_user_buffer(link_fd);
589 	else
590 		verify_umulti_link_info(link_fd, retprobe, offsets, cookies, ref_ctr_offsets);
591 
592 	bpf_link__destroy(link);
593 out:
594 	free(ref_ctr_offsets);
595 	free(offsets);
596 }
597 
598 void test_fill_link_info(void)
599 {
600 	struct test_fill_link_info *skel;
601 	int i;
602 
603 	skel = test_fill_link_info__open_and_load();
604 	if (!ASSERT_OK_PTR(skel, "skel_open"))
605 		return;
606 
607 	/* load kallsyms to compare the addr */
608 	if (!ASSERT_OK(load_kallsyms(), "load_kallsyms"))
609 		goto cleanup;
610 
611 	kprobe_addr = ksym_get_addr(KPROBE_FUNC);
612 	if (test__start_subtest("kprobe_link_info"))
613 		test_kprobe_fill_link_info(skel, BPF_PERF_EVENT_KPROBE, false);
614 	if (test__start_subtest("kretprobe_link_info"))
615 		test_kprobe_fill_link_info(skel, BPF_PERF_EVENT_KRETPROBE, false);
616 	if (test__start_subtest("kprobe_invalid_ubuff"))
617 		test_kprobe_fill_link_info(skel, BPF_PERF_EVENT_KPROBE, true);
618 	if (test__start_subtest("tracepoint_link_info"))
619 		test_tp_fill_link_info(skel);
620 	if (test__start_subtest("event_link_info"))
621 		test_event_fill_link_info(skel);
622 
623 	uprobe_offset = get_uprobe_offset(&uprobe_func);
624 	if (test__start_subtest("uprobe_link_info"))
625 		test_uprobe_fill_link_info(skel, BPF_PERF_EVENT_UPROBE);
626 	if (test__start_subtest("uretprobe_link_info"))
627 		test_uprobe_fill_link_info(skel, BPF_PERF_EVENT_URETPROBE);
628 
629 	qsort(kmulti_syms, KMULTI_CNT, sizeof(kmulti_syms[0]), symbols_cmp_r);
630 	for (i = 0; i < KMULTI_CNT; i++)
631 		kmulti_addrs[i] = ksym_get_addr(kmulti_syms[i]);
632 	if (test__start_subtest("kprobe_multi_link_info")) {
633 		test_kprobe_multi_fill_link_info(skel, false, false, false);
634 		test_kprobe_multi_fill_link_info(skel, false, true, false);
635 	}
636 	if (test__start_subtest("kretprobe_multi_link_info")) {
637 		test_kprobe_multi_fill_link_info(skel, true, false, false);
638 		test_kprobe_multi_fill_link_info(skel, true, true, false);
639 	}
640 	if (test__start_subtest("kprobe_multi_invalid_ubuff"))
641 		test_kprobe_multi_fill_link_info(skel, true, true, true);
642 
643 	if (test__start_subtest("uprobe_multi_link_info"))
644 		test_uprobe_multi_fill_link_info(skel, false, false);
645 	if (test__start_subtest("uretprobe_multi_link_info"))
646 		test_uprobe_multi_fill_link_info(skel, true, false);
647 	if (test__start_subtest("uprobe_multi_invalid"))
648 		test_uprobe_multi_fill_link_info(skel, false, true);
649 
650 cleanup:
651 	test_fill_link_info__destroy(skel);
652 }
653