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1// SPDX-License-Identifier: GPL-2.0
2#include <test_progs.h>
3#include <network_helpers.h>
4
5/* test_tailcall_1 checks basic functionality by patching multiple locations
6 * in a single program for a single tail call slot with nop->jmp, jmp->nop
7 * and jmp->jmp rewrites. Also checks for nop->nop.
8 */
9static void test_tailcall_1(void)
10{
11 int err, map_fd, prog_fd, main_fd, i, j;
12 struct bpf_map *prog_array;
13 struct bpf_program *prog;
14 struct bpf_object *obj;
15 __u32 retval, duration;
16 char prog_name[32];
17 char buff[128] = {};
18
19 err = bpf_prog_load("tailcall1.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
20 &prog_fd);
21 if (CHECK_FAIL(err))
22 return;
23
24 prog = bpf_object__find_program_by_title(obj, "classifier");
25 if (CHECK_FAIL(!prog))
26 goto out;
27
28 main_fd = bpf_program__fd(prog);
29 if (CHECK_FAIL(main_fd < 0))
30 goto out;
31
32 prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
33 if (CHECK_FAIL(!prog_array))
34 goto out;
35
36 map_fd = bpf_map__fd(prog_array);
37 if (CHECK_FAIL(map_fd < 0))
38 goto out;
39
40 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
41 snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
42
43 prog = bpf_object__find_program_by_title(obj, prog_name);
44 if (CHECK_FAIL(!prog))
45 goto out;
46
47 prog_fd = bpf_program__fd(prog);
48 if (CHECK_FAIL(prog_fd < 0))
49 goto out;
50
51 err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
52 if (CHECK_FAIL(err))
53 goto out;
54 }
55
56 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
57 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
58 &duration, &retval, NULL);
59 CHECK(err || retval != i, "tailcall",
60 "err %d errno %d retval %d\n", err, errno, retval);
61
62 err = bpf_map_delete_elem(map_fd, &i);
63 if (CHECK_FAIL(err))
64 goto out;
65 }
66
67 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
68 &duration, &retval, NULL);
69 CHECK(err || retval != 3, "tailcall", "err %d errno %d retval %d\n",
70 err, errno, retval);
71
72 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
73 snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
74
75 prog = bpf_object__find_program_by_title(obj, prog_name);
76 if (CHECK_FAIL(!prog))
77 goto out;
78
79 prog_fd = bpf_program__fd(prog);
80 if (CHECK_FAIL(prog_fd < 0))
81 goto out;
82
83 err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
84 if (CHECK_FAIL(err))
85 goto out;
86 }
87
88 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
89 &duration, &retval, NULL);
90 CHECK(err || retval != 0, "tailcall", "err %d errno %d retval %d\n",
91 err, errno, retval);
92
93 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
94 j = bpf_map__def(prog_array)->max_entries - 1 - i;
95 snprintf(prog_name, sizeof(prog_name), "classifier/%i", j);
96
97 prog = bpf_object__find_program_by_title(obj, prog_name);
98 if (CHECK_FAIL(!prog))
99 goto out;
100
101 prog_fd = bpf_program__fd(prog);
102 if (CHECK_FAIL(prog_fd < 0))
103 goto out;
104
105 err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
106 if (CHECK_FAIL(err))
107 goto out;
108 }
109
110 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
111 j = bpf_map__def(prog_array)->max_entries - 1 - i;
112
113 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
114 &duration, &retval, NULL);
115 CHECK(err || retval != j, "tailcall",
116 "err %d errno %d retval %d\n", err, errno, retval);
117
118 err = bpf_map_delete_elem(map_fd, &i);
119 if (CHECK_FAIL(err))
120 goto out;
121 }
122
123 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
124 &duration, &retval, NULL);
125 CHECK(err || retval != 3, "tailcall", "err %d errno %d retval %d\n",
126 err, errno, retval);
127
128 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
129 err = bpf_map_delete_elem(map_fd, &i);
130 if (CHECK_FAIL(err >= 0 || errno != ENOENT))
131 goto out;
132
133 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
134 &duration, &retval, NULL);
135 CHECK(err || retval != 3, "tailcall",
136 "err %d errno %d retval %d\n", err, errno, retval);
137 }
138
139out:
140 bpf_object__close(obj);
141}
142
143/* test_tailcall_2 checks that patching multiple programs for a single
144 * tail call slot works. It also jumps through several programs and tests
145 * the tail call limit counter.
146 */
147static void test_tailcall_2(void)
148{
149 int err, map_fd, prog_fd, main_fd, i;
150 struct bpf_map *prog_array;
151 struct bpf_program *prog;
152 struct bpf_object *obj;
153 __u32 retval, duration;
154 char prog_name[32];
155 char buff[128] = {};
156
157 err = bpf_prog_load("tailcall2.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
158 &prog_fd);
159 if (CHECK_FAIL(err))
160 return;
161
162 prog = bpf_object__find_program_by_title(obj, "classifier");
163 if (CHECK_FAIL(!prog))
164 goto out;
165
166 main_fd = bpf_program__fd(prog);
167 if (CHECK_FAIL(main_fd < 0))
168 goto out;
169
170 prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
171 if (CHECK_FAIL(!prog_array))
172 goto out;
173
174 map_fd = bpf_map__fd(prog_array);
175 if (CHECK_FAIL(map_fd < 0))
176 goto out;
177
178 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
179 snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
180
181 prog = bpf_object__find_program_by_title(obj, prog_name);
182 if (CHECK_FAIL(!prog))
183 goto out;
184
185 prog_fd = bpf_program__fd(prog);
186 if (CHECK_FAIL(prog_fd < 0))
187 goto out;
188
189 err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
190 if (CHECK_FAIL(err))
191 goto out;
192 }
193
194 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
195 &duration, &retval, NULL);
196 CHECK(err || retval != 2, "tailcall", "err %d errno %d retval %d\n",
197 err, errno, retval);
198
199 i = 2;
200 err = bpf_map_delete_elem(map_fd, &i);
201 if (CHECK_FAIL(err))
202 goto out;
203
204 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
205 &duration, &retval, NULL);
206 CHECK(err || retval != 1, "tailcall", "err %d errno %d retval %d\n",
207 err, errno, retval);
208
209 i = 0;
210 err = bpf_map_delete_elem(map_fd, &i);
211 if (CHECK_FAIL(err))
212 goto out;
213
214 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
215 &duration, &retval, NULL);
216 CHECK(err || retval != 3, "tailcall", "err %d errno %d retval %d\n",
217 err, errno, retval);
218out:
219 bpf_object__close(obj);
220}
221
222/* test_tailcall_3 checks that the count value of the tail call limit
223 * enforcement matches with expectations.
224 */
225static void test_tailcall_3(void)
226{
227 int err, map_fd, prog_fd, main_fd, data_fd, i, val;
228 struct bpf_map *prog_array, *data_map;
229 struct bpf_program *prog;
230 struct bpf_object *obj;
231 __u32 retval, duration;
232 char buff[128] = {};
233
234 err = bpf_prog_load("tailcall3.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
235 &prog_fd);
236 if (CHECK_FAIL(err))
237 return;
238
239 prog = bpf_object__find_program_by_title(obj, "classifier");
240 if (CHECK_FAIL(!prog))
241 goto out;
242
243 main_fd = bpf_program__fd(prog);
244 if (CHECK_FAIL(main_fd < 0))
245 goto out;
246
247 prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
248 if (CHECK_FAIL(!prog_array))
249 goto out;
250
251 map_fd = bpf_map__fd(prog_array);
252 if (CHECK_FAIL(map_fd < 0))
253 goto out;
254
255 prog = bpf_object__find_program_by_title(obj, "classifier/0");
256 if (CHECK_FAIL(!prog))
257 goto out;
258
259 prog_fd = bpf_program__fd(prog);
260 if (CHECK_FAIL(prog_fd < 0))
261 goto out;
262
263 i = 0;
264 err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
265 if (CHECK_FAIL(err))
266 goto out;
267
268 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
269 &duration, &retval, NULL);
270 CHECK(err || retval != 1, "tailcall", "err %d errno %d retval %d\n",
271 err, errno, retval);
272
273 data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
274 if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
275 return;
276
277 data_fd = bpf_map__fd(data_map);
278 if (CHECK_FAIL(map_fd < 0))
279 return;
280
281 i = 0;
282 err = bpf_map_lookup_elem(data_fd, &i, &val);
283 CHECK(err || val != 33, "tailcall count", "err %d errno %d count %d\n",
284 err, errno, val);
285
286 i = 0;
287 err = bpf_map_delete_elem(map_fd, &i);
288 if (CHECK_FAIL(err))
289 goto out;
290
291 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
292 &duration, &retval, NULL);
293 CHECK(err || retval != 0, "tailcall", "err %d errno %d retval %d\n",
294 err, errno, retval);
295out:
296 bpf_object__close(obj);
297}
298
299/* test_tailcall_4 checks that the kernel properly selects indirect jump
300 * for the case where the key is not known. Latter is passed via global
301 * data to select different targets we can compare return value of.
302 */
303static void test_tailcall_4(void)
304{
305 int err, map_fd, prog_fd, main_fd, data_fd, i;
306 struct bpf_map *prog_array, *data_map;
307 struct bpf_program *prog;
308 struct bpf_object *obj;
309 __u32 retval, duration;
310 static const int zero = 0;
311 char buff[128] = {};
312 char prog_name[32];
313
314 err = bpf_prog_load("tailcall4.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
315 &prog_fd);
316 if (CHECK_FAIL(err))
317 return;
318
319 prog = bpf_object__find_program_by_title(obj, "classifier");
320 if (CHECK_FAIL(!prog))
321 goto out;
322
323 main_fd = bpf_program__fd(prog);
324 if (CHECK_FAIL(main_fd < 0))
325 goto out;
326
327 prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
328 if (CHECK_FAIL(!prog_array))
329 goto out;
330
331 map_fd = bpf_map__fd(prog_array);
332 if (CHECK_FAIL(map_fd < 0))
333 goto out;
334
335 data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
336 if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
337 return;
338
339 data_fd = bpf_map__fd(data_map);
340 if (CHECK_FAIL(map_fd < 0))
341 return;
342
343 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
344 snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
345
346 prog = bpf_object__find_program_by_title(obj, prog_name);
347 if (CHECK_FAIL(!prog))
348 goto out;
349
350 prog_fd = bpf_program__fd(prog);
351 if (CHECK_FAIL(prog_fd < 0))
352 goto out;
353
354 err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
355 if (CHECK_FAIL(err))
356 goto out;
357 }
358
359 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
360 err = bpf_map_update_elem(data_fd, &zero, &i, BPF_ANY);
361 if (CHECK_FAIL(err))
362 goto out;
363
364 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
365 &duration, &retval, NULL);
366 CHECK(err || retval != i, "tailcall",
367 "err %d errno %d retval %d\n", err, errno, retval);
368 }
369
370 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
371 err = bpf_map_update_elem(data_fd, &zero, &i, BPF_ANY);
372 if (CHECK_FAIL(err))
373 goto out;
374
375 err = bpf_map_delete_elem(map_fd, &i);
376 if (CHECK_FAIL(err))
377 goto out;
378
379 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
380 &duration, &retval, NULL);
381 CHECK(err || retval != 3, "tailcall",
382 "err %d errno %d retval %d\n", err, errno, retval);
383 }
384out:
385 bpf_object__close(obj);
386}
387
388/* test_tailcall_5 probes similarly to test_tailcall_4 that the kernel generates
389 * an indirect jump when the keys are const but different from different branches.
390 */
391static void test_tailcall_5(void)
392{
393 int err, map_fd, prog_fd, main_fd, data_fd, i, key[] = { 1111, 1234, 5678 };
394 struct bpf_map *prog_array, *data_map;
395 struct bpf_program *prog;
396 struct bpf_object *obj;
397 __u32 retval, duration;
398 static const int zero = 0;
399 char buff[128] = {};
400 char prog_name[32];
401
402 err = bpf_prog_load("tailcall5.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
403 &prog_fd);
404 if (CHECK_FAIL(err))
405 return;
406
407 prog = bpf_object__find_program_by_title(obj, "classifier");
408 if (CHECK_FAIL(!prog))
409 goto out;
410
411 main_fd = bpf_program__fd(prog);
412 if (CHECK_FAIL(main_fd < 0))
413 goto out;
414
415 prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
416 if (CHECK_FAIL(!prog_array))
417 goto out;
418
419 map_fd = bpf_map__fd(prog_array);
420 if (CHECK_FAIL(map_fd < 0))
421 goto out;
422
423 data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
424 if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
425 return;
426
427 data_fd = bpf_map__fd(data_map);
428 if (CHECK_FAIL(map_fd < 0))
429 return;
430
431 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
432 snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
433
434 prog = bpf_object__find_program_by_title(obj, prog_name);
435 if (CHECK_FAIL(!prog))
436 goto out;
437
438 prog_fd = bpf_program__fd(prog);
439 if (CHECK_FAIL(prog_fd < 0))
440 goto out;
441
442 err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
443 if (CHECK_FAIL(err))
444 goto out;
445 }
446
447 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
448 err = bpf_map_update_elem(data_fd, &zero, &key[i], BPF_ANY);
449 if (CHECK_FAIL(err))
450 goto out;
451
452 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
453 &duration, &retval, NULL);
454 CHECK(err || retval != i, "tailcall",
455 "err %d errno %d retval %d\n", err, errno, retval);
456 }
457
458 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
459 err = bpf_map_update_elem(data_fd, &zero, &key[i], BPF_ANY);
460 if (CHECK_FAIL(err))
461 goto out;
462
463 err = bpf_map_delete_elem(map_fd, &i);
464 if (CHECK_FAIL(err))
465 goto out;
466
467 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
468 &duration, &retval, NULL);
469 CHECK(err || retval != 3, "tailcall",
470 "err %d errno %d retval %d\n", err, errno, retval);
471 }
472out:
473 bpf_object__close(obj);
474}
475
476/* test_tailcall_bpf2bpf_1 purpose is to make sure that tailcalls are working
477 * correctly in correlation with BPF subprograms
478 */
479static void test_tailcall_bpf2bpf_1(void)
480{
481 int err, map_fd, prog_fd, main_fd, i;
482 struct bpf_map *prog_array;
483 struct bpf_program *prog;
484 struct bpf_object *obj;
485 __u32 retval, duration;
486 char prog_name[32];
487
488 err = bpf_prog_load("tailcall_bpf2bpf1.o", BPF_PROG_TYPE_SCHED_CLS,
489 &obj, &prog_fd);
490 if (CHECK_FAIL(err))
491 return;
492
493 prog = bpf_object__find_program_by_title(obj, "classifier");
494 if (CHECK_FAIL(!prog))
495 goto out;
496
497 main_fd = bpf_program__fd(prog);
498 if (CHECK_FAIL(main_fd < 0))
499 goto out;
500
501 prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
502 if (CHECK_FAIL(!prog_array))
503 goto out;
504
505 map_fd = bpf_map__fd(prog_array);
506 if (CHECK_FAIL(map_fd < 0))
507 goto out;
508
509 /* nop -> jmp */
510 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
511 snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
512
513 prog = bpf_object__find_program_by_title(obj, prog_name);
514 if (CHECK_FAIL(!prog))
515 goto out;
516
517 prog_fd = bpf_program__fd(prog);
518 if (CHECK_FAIL(prog_fd < 0))
519 goto out;
520
521 err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
522 if (CHECK_FAIL(err))
523 goto out;
524 }
525
526 err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
527 0, &retval, &duration);
528 CHECK(err || retval != 1, "tailcall",
529 "err %d errno %d retval %d\n", err, errno, retval);
530
531 /* jmp -> nop, call subprog that will do tailcall */
532 i = 1;
533 err = bpf_map_delete_elem(map_fd, &i);
534 if (CHECK_FAIL(err))
535 goto out;
536
537 err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
538 0, &retval, &duration);
539 CHECK(err || retval != 0, "tailcall", "err %d errno %d retval %d\n",
540 err, errno, retval);
541
542 /* make sure that subprog can access ctx and entry prog that
543 * called this subprog can properly return
544 */
545 i = 0;
546 err = bpf_map_delete_elem(map_fd, &i);
547 if (CHECK_FAIL(err))
548 goto out;
549
550 err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
551 0, &retval, &duration);
552 CHECK(err || retval != sizeof(pkt_v4) * 2,
553 "tailcall", "err %d errno %d retval %d\n",
554 err, errno, retval);
555out:
556 bpf_object__close(obj);
557}
558
559/* test_tailcall_bpf2bpf_2 checks that the count value of the tail call limit
560 * enforcement matches with expectations when tailcall is preceded with
561 * bpf2bpf call.
562 */
563static void test_tailcall_bpf2bpf_2(void)
564{
565 int err, map_fd, prog_fd, main_fd, data_fd, i, val;
566 struct bpf_map *prog_array, *data_map;
567 struct bpf_program *prog;
568 struct bpf_object *obj;
569 __u32 retval, duration;
570 char buff[128] = {};
571
572 err = bpf_prog_load("tailcall_bpf2bpf2.o", BPF_PROG_TYPE_SCHED_CLS,
573 &obj, &prog_fd);
574 if (CHECK_FAIL(err))
575 return;
576
577 prog = bpf_object__find_program_by_title(obj, "classifier");
578 if (CHECK_FAIL(!prog))
579 goto out;
580
581 main_fd = bpf_program__fd(prog);
582 if (CHECK_FAIL(main_fd < 0))
583 goto out;
584
585 prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
586 if (CHECK_FAIL(!prog_array))
587 goto out;
588
589 map_fd = bpf_map__fd(prog_array);
590 if (CHECK_FAIL(map_fd < 0))
591 goto out;
592
593 prog = bpf_object__find_program_by_title(obj, "classifier/0");
594 if (CHECK_FAIL(!prog))
595 goto out;
596
597 prog_fd = bpf_program__fd(prog);
598 if (CHECK_FAIL(prog_fd < 0))
599 goto out;
600
601 i = 0;
602 err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
603 if (CHECK_FAIL(err))
604 goto out;
605
606 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
607 &duration, &retval, NULL);
608 CHECK(err || retval != 1, "tailcall", "err %d errno %d retval %d\n",
609 err, errno, retval);
610
611 data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
612 if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
613 return;
614
615 data_fd = bpf_map__fd(data_map);
616 if (CHECK_FAIL(map_fd < 0))
617 return;
618
619 i = 0;
620 err = bpf_map_lookup_elem(data_fd, &i, &val);
621 CHECK(err || val != 33, "tailcall count", "err %d errno %d count %d\n",
622 err, errno, val);
623
624 i = 0;
625 err = bpf_map_delete_elem(map_fd, &i);
626 if (CHECK_FAIL(err))
627 goto out;
628
629 err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
630 &duration, &retval, NULL);
631 CHECK(err || retval != 0, "tailcall", "err %d errno %d retval %d\n",
632 err, errno, retval);
633out:
634 bpf_object__close(obj);
635}
636
637/* test_tailcall_bpf2bpf_3 checks that non-trivial amount of stack (up to
638 * 256 bytes) can be used within bpf subprograms that have the tailcalls
639 * in them
640 */
641static void test_tailcall_bpf2bpf_3(void)
642{
643 int err, map_fd, prog_fd, main_fd, i;
644 struct bpf_map *prog_array;
645 struct bpf_program *prog;
646 struct bpf_object *obj;
647 __u32 retval, duration;
648 char prog_name[32];
649
650 err = bpf_prog_load("tailcall_bpf2bpf3.o", BPF_PROG_TYPE_SCHED_CLS,
651 &obj, &prog_fd);
652 if (CHECK_FAIL(err))
653 return;
654
655 prog = bpf_object__find_program_by_title(obj, "classifier");
656 if (CHECK_FAIL(!prog))
657 goto out;
658
659 main_fd = bpf_program__fd(prog);
660 if (CHECK_FAIL(main_fd < 0))
661 goto out;
662
663 prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
664 if (CHECK_FAIL(!prog_array))
665 goto out;
666
667 map_fd = bpf_map__fd(prog_array);
668 if (CHECK_FAIL(map_fd < 0))
669 goto out;
670
671 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
672 snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
673
674 prog = bpf_object__find_program_by_title(obj, prog_name);
675 if (CHECK_FAIL(!prog))
676 goto out;
677
678 prog_fd = bpf_program__fd(prog);
679 if (CHECK_FAIL(prog_fd < 0))
680 goto out;
681
682 err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
683 if (CHECK_FAIL(err))
684 goto out;
685 }
686
687 err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
688 &duration, &retval, NULL);
689 CHECK(err || retval != sizeof(pkt_v4) * 3,
690 "tailcall", "err %d errno %d retval %d\n",
691 err, errno, retval);
692
693 i = 1;
694 err = bpf_map_delete_elem(map_fd, &i);
695 if (CHECK_FAIL(err))
696 goto out;
697
698 err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
699 &duration, &retval, NULL);
700 CHECK(err || retval != sizeof(pkt_v4),
701 "tailcall", "err %d errno %d retval %d\n",
702 err, errno, retval);
703
704 i = 0;
705 err = bpf_map_delete_elem(map_fd, &i);
706 if (CHECK_FAIL(err))
707 goto out;
708
709 err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
710 &duration, &retval, NULL);
711 CHECK(err || retval != sizeof(pkt_v4) * 2,
712 "tailcall", "err %d errno %d retval %d\n",
713 err, errno, retval);
714out:
715 bpf_object__close(obj);
716}
717
718#include "tailcall_bpf2bpf4.skel.h"
719
720/* test_tailcall_bpf2bpf_4 checks that tailcall counter is correctly preserved
721 * across tailcalls combined with bpf2bpf calls. for making sure that tailcall
722 * counter behaves correctly, bpf program will go through following flow:
723 *
724 * entry -> entry_subprog -> tailcall0 -> bpf_func0 -> subprog0 ->
725 * -> tailcall1 -> bpf_func1 -> subprog1 -> tailcall2 -> bpf_func2 ->
726 * subprog2 [here bump global counter] --------^
727 *
728 * We go through first two tailcalls and start counting from the subprog2 where
729 * the loop begins. At the end of the test make sure that the global counter is
730 * equal to 31, because tailcall counter includes the first two tailcalls
731 * whereas global counter is incremented only on loop presented on flow above.
732 *
733 * The noise parameter is used to insert bpf_map_update calls into the logic
734 * to force verifier to patch instructions. This allows us to ensure jump
735 * logic remains correct with instruction movement.
736 */
737static void test_tailcall_bpf2bpf_4(bool noise)
738{
739 int err, map_fd, prog_fd, main_fd, data_fd, i;
740 struct tailcall_bpf2bpf4__bss val;
741 struct bpf_map *prog_array, *data_map;
742 struct bpf_program *prog;
743 struct bpf_object *obj;
744 __u32 retval, duration;
745 char prog_name[32];
746
747 err = bpf_prog_load("tailcall_bpf2bpf4.o", BPF_PROG_TYPE_SCHED_CLS,
748 &obj, &prog_fd);
749 if (CHECK_FAIL(err))
750 return;
751
752 prog = bpf_object__find_program_by_title(obj, "classifier");
753 if (CHECK_FAIL(!prog))
754 goto out;
755
756 main_fd = bpf_program__fd(prog);
757 if (CHECK_FAIL(main_fd < 0))
758 goto out;
759
760 prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
761 if (CHECK_FAIL(!prog_array))
762 goto out;
763
764 map_fd = bpf_map__fd(prog_array);
765 if (CHECK_FAIL(map_fd < 0))
766 goto out;
767
768 for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
769 snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
770
771 prog = bpf_object__find_program_by_title(obj, prog_name);
772 if (CHECK_FAIL(!prog))
773 goto out;
774
775 prog_fd = bpf_program__fd(prog);
776 if (CHECK_FAIL(prog_fd < 0))
777 goto out;
778
779 err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
780 if (CHECK_FAIL(err))
781 goto out;
782 }
783
784 data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
785 if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
786 return;
787
788 data_fd = bpf_map__fd(data_map);
789 if (CHECK_FAIL(map_fd < 0))
790 return;
791
792 i = 0;
793 val.noise = noise;
794 val.count = 0;
795 err = bpf_map_update_elem(data_fd, &i, &val, BPF_ANY);
796 if (CHECK_FAIL(err))
797 goto out;
798
799 err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
800 &duration, &retval, NULL);
801 CHECK(err || retval != sizeof(pkt_v4) * 3, "tailcall", "err %d errno %d retval %d\n",
802 err, errno, retval);
803
804 i = 0;
805 err = bpf_map_lookup_elem(data_fd, &i, &val);
806 CHECK(err || val.count != 31, "tailcall count", "err %d errno %d count %d\n",
807 err, errno, val.count);
808
809out:
810 bpf_object__close(obj);
811}
812
813void test_tailcalls(void)
814{
815 if (test__start_subtest("tailcall_1"))
816 test_tailcall_1();
817 if (test__start_subtest("tailcall_2"))
818 test_tailcall_2();
819 if (test__start_subtest("tailcall_3"))
820 test_tailcall_3();
821 if (test__start_subtest("tailcall_4"))
822 test_tailcall_4();
823 if (test__start_subtest("tailcall_5"))
824 test_tailcall_5();
825 if (test__start_subtest("tailcall_bpf2bpf_1"))
826 test_tailcall_bpf2bpf_1();
827 if (test__start_subtest("tailcall_bpf2bpf_2"))
828 test_tailcall_bpf2bpf_2();
829 if (test__start_subtest("tailcall_bpf2bpf_3"))
830 test_tailcall_bpf2bpf_3();
831 if (test__start_subtest("tailcall_bpf2bpf_4"))
832 test_tailcall_bpf2bpf_4(false);
833 if (test__start_subtest("tailcall_bpf2bpf_5"))
834 test_tailcall_bpf2bpf_4(true);
835}