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1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
3
4#include <stdbool.h>
5#include <linux/bpf.h>
6#include <bpf/bpf_helpers.h>
7#include "bpf_misc.h"
8#include "bpf_compiler.h"
9
10#define ARRAY_SIZE(x) (int)(sizeof(x) / sizeof((x)[0]))
11
12static volatile int zero = 0;
13
14int my_pid;
15int arr[256];
16int small_arr[16] SEC(".data.small_arr");
17
18struct {
19 __uint(type, BPF_MAP_TYPE_HASH);
20 __uint(max_entries, 10);
21 __type(key, int);
22 __type(value, int);
23} amap SEC(".maps");
24
25#ifdef REAL_TEST
26#define MY_PID_GUARD() if (my_pid != (bpf_get_current_pid_tgid() >> 32)) return 0
27#else
28#define MY_PID_GUARD() ({ })
29#endif
30
31SEC("?raw_tp")
32__failure __msg("math between map_value pointer and register with unbounded min value is not allowed")
33int iter_err_unsafe_c_loop(const void *ctx)
34{
35 struct bpf_iter_num it;
36 int *v, i = zero; /* obscure initial value of i */
37
38 MY_PID_GUARD();
39
40 bpf_iter_num_new(&it, 0, 1000);
41 while ((v = bpf_iter_num_next(&it))) {
42 i++;
43 }
44 bpf_iter_num_destroy(&it);
45
46 small_arr[i] = 123; /* invalid */
47
48 return 0;
49}
50
51SEC("?raw_tp")
52__failure __msg("unbounded memory access")
53int iter_err_unsafe_asm_loop(const void *ctx)
54{
55 struct bpf_iter_num it;
56
57 MY_PID_GUARD();
58
59 asm volatile (
60 "r6 = %[zero];" /* iteration counter */
61 "r1 = %[it];" /* iterator state */
62 "r2 = 0;"
63 "r3 = 1000;"
64 "r4 = 1;"
65 "call %[bpf_iter_num_new];"
66 "loop:"
67 "r1 = %[it];"
68 "call %[bpf_iter_num_next];"
69 "if r0 == 0 goto out;"
70 "r6 += 1;"
71 "goto loop;"
72 "out:"
73 "r1 = %[it];"
74 "call %[bpf_iter_num_destroy];"
75 "r1 = %[small_arr];"
76 "r2 = r6;"
77 "r2 <<= 2;"
78 "r1 += r2;"
79 "*(u32 *)(r1 + 0) = r6;" /* invalid */
80 :
81 : [it]"r"(&it),
82 [small_arr]"r"(small_arr),
83 [zero]"r"(zero),
84 __imm(bpf_iter_num_new),
85 __imm(bpf_iter_num_next),
86 __imm(bpf_iter_num_destroy)
87 : __clobber_common, "r6"
88 );
89
90 return 0;
91}
92
93SEC("raw_tp")
94__success
95int iter_while_loop(const void *ctx)
96{
97 struct bpf_iter_num it;
98 int *v;
99
100 MY_PID_GUARD();
101
102 bpf_iter_num_new(&it, 0, 3);
103 while ((v = bpf_iter_num_next(&it))) {
104 bpf_printk("ITER_BASIC: E1 VAL: v=%d", *v);
105 }
106 bpf_iter_num_destroy(&it);
107
108 return 0;
109}
110
111SEC("raw_tp")
112__success
113int iter_while_loop_auto_cleanup(const void *ctx)
114{
115 __attribute__((cleanup(bpf_iter_num_destroy))) struct bpf_iter_num it;
116 int *v;
117
118 MY_PID_GUARD();
119
120 bpf_iter_num_new(&it, 0, 3);
121 while ((v = bpf_iter_num_next(&it))) {
122 bpf_printk("ITER_BASIC: E1 VAL: v=%d", *v);
123 }
124 /* (!) no explicit bpf_iter_num_destroy() */
125
126 return 0;
127}
128
129SEC("raw_tp")
130__success
131int iter_for_loop(const void *ctx)
132{
133 struct bpf_iter_num it;
134 int *v;
135
136 MY_PID_GUARD();
137
138 bpf_iter_num_new(&it, 5, 10);
139 for (v = bpf_iter_num_next(&it); v; v = bpf_iter_num_next(&it)) {
140 bpf_printk("ITER_BASIC: E2 VAL: v=%d", *v);
141 }
142 bpf_iter_num_destroy(&it);
143
144 return 0;
145}
146
147SEC("raw_tp")
148__success
149int iter_bpf_for_each_macro(const void *ctx)
150{
151 int *v;
152
153 MY_PID_GUARD();
154
155 bpf_for_each(num, v, 5, 10) {
156 bpf_printk("ITER_BASIC: E2 VAL: v=%d", *v);
157 }
158
159 return 0;
160}
161
162SEC("raw_tp")
163__success
164int iter_bpf_for_macro(const void *ctx)
165{
166 int i;
167
168 MY_PID_GUARD();
169
170 bpf_for(i, 5, 10) {
171 bpf_printk("ITER_BASIC: E2 VAL: v=%d", i);
172 }
173
174 return 0;
175}
176
177SEC("raw_tp")
178__success
179int iter_pragma_unroll_loop(const void *ctx)
180{
181 struct bpf_iter_num it;
182 int *v, i;
183
184 MY_PID_GUARD();
185
186 bpf_iter_num_new(&it, 0, 2);
187 __pragma_loop_no_unroll
188 for (i = 0; i < 3; i++) {
189 v = bpf_iter_num_next(&it);
190 bpf_printk("ITER_BASIC: E3 VAL: i=%d v=%d", i, v ? *v : -1);
191 }
192 bpf_iter_num_destroy(&it);
193
194 return 0;
195}
196
197SEC("raw_tp")
198__success
199int iter_manual_unroll_loop(const void *ctx)
200{
201 struct bpf_iter_num it;
202 int *v;
203
204 MY_PID_GUARD();
205
206 bpf_iter_num_new(&it, 100, 200);
207 v = bpf_iter_num_next(&it);
208 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
209 v = bpf_iter_num_next(&it);
210 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
211 v = bpf_iter_num_next(&it);
212 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
213 v = bpf_iter_num_next(&it);
214 bpf_printk("ITER_BASIC: E4 VAL: v=%d\n", v ? *v : -1);
215 bpf_iter_num_destroy(&it);
216
217 return 0;
218}
219
220SEC("raw_tp")
221__success
222int iter_multiple_sequential_loops(const void *ctx)
223{
224 struct bpf_iter_num it;
225 int *v, i;
226
227 MY_PID_GUARD();
228
229 bpf_iter_num_new(&it, 0, 3);
230 while ((v = bpf_iter_num_next(&it))) {
231 bpf_printk("ITER_BASIC: E1 VAL: v=%d", *v);
232 }
233 bpf_iter_num_destroy(&it);
234
235 bpf_iter_num_new(&it, 5, 10);
236 for (v = bpf_iter_num_next(&it); v; v = bpf_iter_num_next(&it)) {
237 bpf_printk("ITER_BASIC: E2 VAL: v=%d", *v);
238 }
239 bpf_iter_num_destroy(&it);
240
241 bpf_iter_num_new(&it, 0, 2);
242 __pragma_loop_no_unroll
243 for (i = 0; i < 3; i++) {
244 v = bpf_iter_num_next(&it);
245 bpf_printk("ITER_BASIC: E3 VAL: i=%d v=%d", i, v ? *v : -1);
246 }
247 bpf_iter_num_destroy(&it);
248
249 bpf_iter_num_new(&it, 100, 200);
250 v = bpf_iter_num_next(&it);
251 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
252 v = bpf_iter_num_next(&it);
253 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
254 v = bpf_iter_num_next(&it);
255 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
256 v = bpf_iter_num_next(&it);
257 bpf_printk("ITER_BASIC: E4 VAL: v=%d\n", v ? *v : -1);
258 bpf_iter_num_destroy(&it);
259
260 return 0;
261}
262
263SEC("raw_tp")
264__success
265int iter_limit_cond_break_loop(const void *ctx)
266{
267 struct bpf_iter_num it;
268 int *v, i = 0, sum = 0;
269
270 MY_PID_GUARD();
271
272 bpf_iter_num_new(&it, 0, 10);
273 while ((v = bpf_iter_num_next(&it))) {
274 bpf_printk("ITER_SIMPLE: i=%d v=%d", i, *v);
275 sum += *v;
276
277 i++;
278 if (i > 3)
279 break;
280 }
281 bpf_iter_num_destroy(&it);
282
283 bpf_printk("ITER_SIMPLE: sum=%d\n", sum);
284
285 return 0;
286}
287
288SEC("raw_tp")
289__success
290int iter_obfuscate_counter(const void *ctx)
291{
292 struct bpf_iter_num it;
293 int *v, sum = 0;
294 /* Make i's initial value unknowable for verifier to prevent it from
295 * pruning if/else branch inside the loop body and marking i as precise.
296 */
297 int i = zero;
298
299 MY_PID_GUARD();
300
301 bpf_iter_num_new(&it, 0, 10);
302 while ((v = bpf_iter_num_next(&it))) {
303 int x;
304
305 i += 1;
306
307 /* If we initialized i as `int i = 0;` above, verifier would
308 * track that i becomes 1 on first iteration after increment
309 * above, and here verifier would eagerly prune else branch
310 * and mark i as precise, ruining open-coded iterator logic
311 * completely, as each next iteration would have a different
312 * *precise* value of i, and thus there would be no
313 * convergence of state. This would result in reaching maximum
314 * instruction limit, no matter what the limit is.
315 */
316 if (i == 1)
317 x = 123;
318 else
319 x = i * 3 + 1;
320
321 bpf_printk("ITER_OBFUSCATE_COUNTER: i=%d v=%d x=%d", i, *v, x);
322
323 sum += x;
324 }
325 bpf_iter_num_destroy(&it);
326
327 bpf_printk("ITER_OBFUSCATE_COUNTER: sum=%d\n", sum);
328
329 return 0;
330}
331
332SEC("raw_tp")
333__success
334int iter_search_loop(const void *ctx)
335{
336 struct bpf_iter_num it;
337 int *v, *elem = NULL;
338 bool found = false;
339
340 MY_PID_GUARD();
341
342 bpf_iter_num_new(&it, 0, 10);
343
344 while ((v = bpf_iter_num_next(&it))) {
345 bpf_printk("ITER_SEARCH_LOOP: v=%d", *v);
346
347 if (*v == 2) {
348 found = true;
349 elem = v;
350 barrier_var(elem);
351 }
352 }
353
354 /* should fail to verify if bpf_iter_num_destroy() is here */
355
356 if (found)
357 /* here found element will be wrong, we should have copied
358 * value to a variable, but here we want to make sure we can
359 * access memory after the loop anyways
360 */
361 bpf_printk("ITER_SEARCH_LOOP: FOUND IT = %d!\n", *elem);
362 else
363 bpf_printk("ITER_SEARCH_LOOP: NOT FOUND IT!\n");
364
365 bpf_iter_num_destroy(&it);
366
367 return 0;
368}
369
370SEC("raw_tp")
371__success
372int iter_array_fill(const void *ctx)
373{
374 int sum, i;
375
376 MY_PID_GUARD();
377
378 bpf_for(i, 0, ARRAY_SIZE(arr)) {
379 arr[i] = i * 2;
380 }
381
382 sum = 0;
383 bpf_for(i, 0, ARRAY_SIZE(arr)) {
384 sum += arr[i];
385 }
386
387 bpf_printk("ITER_ARRAY_FILL: sum=%d (should be %d)\n", sum, 255 * 256);
388
389 return 0;
390}
391
392static int arr2d[4][5];
393static int arr2d_row_sums[4];
394static int arr2d_col_sums[5];
395
396SEC("raw_tp")
397__success
398int iter_nested_iters(const void *ctx)
399{
400 int sum, row, col;
401
402 MY_PID_GUARD();
403
404 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
405 bpf_for( col, 0, ARRAY_SIZE(arr2d[0])) {
406 arr2d[row][col] = row * col;
407 }
408 }
409
410 /* zero-initialize sums */
411 sum = 0;
412 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
413 arr2d_row_sums[row] = 0;
414 }
415 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
416 arr2d_col_sums[col] = 0;
417 }
418
419 /* calculate sums */
420 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
421 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
422 sum += arr2d[row][col];
423 arr2d_row_sums[row] += arr2d[row][col];
424 arr2d_col_sums[col] += arr2d[row][col];
425 }
426 }
427
428 bpf_printk("ITER_NESTED_ITERS: total sum=%d", sum);
429 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
430 bpf_printk("ITER_NESTED_ITERS: row #%d sum=%d", row, arr2d_row_sums[row]);
431 }
432 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
433 bpf_printk("ITER_NESTED_ITERS: col #%d sum=%d%s",
434 col, arr2d_col_sums[col],
435 col == ARRAY_SIZE(arr2d[0]) - 1 ? "\n" : "");
436 }
437
438 return 0;
439}
440
441SEC("raw_tp")
442__success
443int iter_nested_deeply_iters(const void *ctx)
444{
445 int sum = 0;
446
447 MY_PID_GUARD();
448
449 bpf_repeat(10) {
450 bpf_repeat(10) {
451 bpf_repeat(10) {
452 bpf_repeat(10) {
453 bpf_repeat(10) {
454 sum += 1;
455 }
456 }
457 }
458 }
459 /* validate that we can break from inside bpf_repeat() */
460 break;
461 }
462
463 return sum;
464}
465
466static __noinline void fill_inner_dimension(int row)
467{
468 int col;
469
470 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
471 arr2d[row][col] = row * col;
472 }
473}
474
475static __noinline int sum_inner_dimension(int row)
476{
477 int sum = 0, col;
478
479 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
480 sum += arr2d[row][col];
481 arr2d_row_sums[row] += arr2d[row][col];
482 arr2d_col_sums[col] += arr2d[row][col];
483 }
484
485 return sum;
486}
487
488SEC("raw_tp")
489__success
490int iter_subprog_iters(const void *ctx)
491{
492 int sum, row, col;
493
494 MY_PID_GUARD();
495
496 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
497 fill_inner_dimension(row);
498 }
499
500 /* zero-initialize sums */
501 sum = 0;
502 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
503 arr2d_row_sums[row] = 0;
504 }
505 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
506 arr2d_col_sums[col] = 0;
507 }
508
509 /* calculate sums */
510 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
511 sum += sum_inner_dimension(row);
512 }
513
514 bpf_printk("ITER_SUBPROG_ITERS: total sum=%d", sum);
515 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
516 bpf_printk("ITER_SUBPROG_ITERS: row #%d sum=%d",
517 row, arr2d_row_sums[row]);
518 }
519 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
520 bpf_printk("ITER_SUBPROG_ITERS: col #%d sum=%d%s",
521 col, arr2d_col_sums[col],
522 col == ARRAY_SIZE(arr2d[0]) - 1 ? "\n" : "");
523 }
524
525 return 0;
526}
527
528struct {
529 __uint(type, BPF_MAP_TYPE_ARRAY);
530 __type(key, int);
531 __type(value, int);
532 __uint(max_entries, 1000);
533} arr_map SEC(".maps");
534
535SEC("?raw_tp")
536__failure __msg("invalid mem access 'scalar'")
537int iter_err_too_permissive1(const void *ctx)
538{
539 int *map_val = NULL;
540 int key = 0;
541
542 MY_PID_GUARD();
543
544 map_val = bpf_map_lookup_elem(&arr_map, &key);
545 if (!map_val)
546 return 0;
547
548 bpf_repeat(1000000) {
549 map_val = NULL;
550 }
551
552 *map_val = 123;
553
554 return 0;
555}
556
557SEC("?raw_tp")
558__failure __msg("invalid mem access 'map_value_or_null'")
559int iter_err_too_permissive2(const void *ctx)
560{
561 int *map_val = NULL;
562 int key = 0;
563
564 MY_PID_GUARD();
565
566 map_val = bpf_map_lookup_elem(&arr_map, &key);
567 if (!map_val)
568 return 0;
569
570 bpf_repeat(1000000) {
571 map_val = bpf_map_lookup_elem(&arr_map, &key);
572 }
573
574 *map_val = 123;
575
576 return 0;
577}
578
579SEC("?raw_tp")
580__failure __msg("invalid mem access 'map_value_or_null'")
581int iter_err_too_permissive3(const void *ctx)
582{
583 int *map_val = NULL;
584 int key = 0;
585 bool found = false;
586
587 MY_PID_GUARD();
588
589 bpf_repeat(1000000) {
590 map_val = bpf_map_lookup_elem(&arr_map, &key);
591 found = true;
592 }
593
594 if (found)
595 *map_val = 123;
596
597 return 0;
598}
599
600SEC("raw_tp")
601__success
602int iter_tricky_but_fine(const void *ctx)
603{
604 int *map_val = NULL;
605 int key = 0;
606 bool found = false;
607
608 MY_PID_GUARD();
609
610 bpf_repeat(1000000) {
611 map_val = bpf_map_lookup_elem(&arr_map, &key);
612 if (map_val) {
613 found = true;
614 break;
615 }
616 }
617
618 if (found)
619 *map_val = 123;
620
621 return 0;
622}
623
624#define __bpf_memzero(p, sz) bpf_probe_read_kernel((p), (sz), 0)
625
626SEC("raw_tp")
627__success
628int iter_stack_array_loop(const void *ctx)
629{
630 long arr1[16], arr2[16], sum = 0;
631 int i;
632
633 MY_PID_GUARD();
634
635 /* zero-init arr1 and arr2 in such a way that verifier doesn't know
636 * it's all zeros; if we don't do that, we'll make BPF verifier track
637 * all combination of zero/non-zero stack slots for arr1/arr2, which
638 * will lead to O(2^(ARRAY_SIZE(arr1)+ARRAY_SIZE(arr2))) different
639 * states
640 */
641 __bpf_memzero(arr1, sizeof(arr1));
642 __bpf_memzero(arr2, sizeof(arr1));
643
644 /* validate that we can break and continue when using bpf_for() */
645 bpf_for(i, 0, ARRAY_SIZE(arr1)) {
646 if (i & 1) {
647 arr1[i] = i;
648 continue;
649 } else {
650 arr2[i] = i;
651 break;
652 }
653 }
654
655 bpf_for(i, 0, ARRAY_SIZE(arr1)) {
656 sum += arr1[i] + arr2[i];
657 }
658
659 return sum;
660}
661
662static __noinline void fill(struct bpf_iter_num *it, int *arr, __u32 n, int mul)
663{
664 int *t, i;
665
666 while ((t = bpf_iter_num_next(it))) {
667 i = *t;
668 if (i >= n)
669 break;
670 arr[i] = i * mul;
671 }
672}
673
674static __noinline int sum(struct bpf_iter_num *it, int *arr, __u32 n)
675{
676 int *t, i, sum = 0;;
677
678 while ((t = bpf_iter_num_next(it))) {
679 i = *t;
680 if ((__u32)i >= n)
681 break;
682 sum += arr[i];
683 }
684
685 return sum;
686}
687
688SEC("raw_tp")
689__success
690int iter_pass_iter_ptr_to_subprog(const void *ctx)
691{
692 int arr1[16], arr2[32];
693 struct bpf_iter_num it;
694 int n, sum1, sum2;
695
696 MY_PID_GUARD();
697
698 /* fill arr1 */
699 n = ARRAY_SIZE(arr1);
700 bpf_iter_num_new(&it, 0, n);
701 fill(&it, arr1, n, 2);
702 bpf_iter_num_destroy(&it);
703
704 /* fill arr2 */
705 n = ARRAY_SIZE(arr2);
706 bpf_iter_num_new(&it, 0, n);
707 fill(&it, arr2, n, 10);
708 bpf_iter_num_destroy(&it);
709
710 /* sum arr1 */
711 n = ARRAY_SIZE(arr1);
712 bpf_iter_num_new(&it, 0, n);
713 sum1 = sum(&it, arr1, n);
714 bpf_iter_num_destroy(&it);
715
716 /* sum arr2 */
717 n = ARRAY_SIZE(arr2);
718 bpf_iter_num_new(&it, 0, n);
719 sum2 = sum(&it, arr2, n);
720 bpf_iter_num_destroy(&it);
721
722 bpf_printk("sum1=%d, sum2=%d", sum1, sum2);
723
724 return 0;
725}
726
727SEC("?raw_tp")
728__failure
729__msg("R1 type=scalar expected=fp")
730__naked int delayed_read_mark(void)
731{
732 /* This is equivalent to C program below.
733 * The call to bpf_iter_num_next() is reachable with r7 values &fp[-16] and 0xdead.
734 * State with r7=&fp[-16] is visited first and follows r6 != 42 ... continue branch.
735 * At this point iterator next() call is reached with r7 that has no read mark.
736 * Loop body with r7=0xdead would only be visited if verifier would decide to continue
737 * with second loop iteration. Absence of read mark on r7 might affect state
738 * equivalent logic used for iterator convergence tracking.
739 *
740 * r7 = &fp[-16]
741 * fp[-16] = 0
742 * r6 = bpf_get_prandom_u32()
743 * bpf_iter_num_new(&fp[-8], 0, 10)
744 * while (bpf_iter_num_next(&fp[-8])) {
745 * r6++
746 * if (r6 != 42) {
747 * r7 = 0xdead
748 * continue;
749 * }
750 * bpf_probe_read_user(r7, 8, 0xdeadbeef); // this is not safe
751 * }
752 * bpf_iter_num_destroy(&fp[-8])
753 * return 0
754 */
755 asm volatile (
756 "r7 = r10;"
757 "r7 += -16;"
758 "r0 = 0;"
759 "*(u64 *)(r7 + 0) = r0;"
760 "call %[bpf_get_prandom_u32];"
761 "r6 = r0;"
762 "r1 = r10;"
763 "r1 += -8;"
764 "r2 = 0;"
765 "r3 = 10;"
766 "call %[bpf_iter_num_new];"
767 "1:"
768 "r1 = r10;"
769 "r1 += -8;"
770 "call %[bpf_iter_num_next];"
771 "if r0 == 0 goto 2f;"
772 "r6 += 1;"
773 "if r6 != 42 goto 3f;"
774 "r7 = 0xdead;"
775 "goto 1b;"
776 "3:"
777 "r1 = r7;"
778 "r2 = 8;"
779 "r3 = 0xdeadbeef;"
780 "call %[bpf_probe_read_user];"
781 "goto 1b;"
782 "2:"
783 "r1 = r10;"
784 "r1 += -8;"
785 "call %[bpf_iter_num_destroy];"
786 "r0 = 0;"
787 "exit;"
788 :
789 : __imm(bpf_get_prandom_u32),
790 __imm(bpf_iter_num_new),
791 __imm(bpf_iter_num_next),
792 __imm(bpf_iter_num_destroy),
793 __imm(bpf_probe_read_user)
794 : __clobber_all
795 );
796}
797
798SEC("?raw_tp")
799__failure
800__msg("math between fp pointer and register with unbounded")
801__naked int delayed_precision_mark(void)
802{
803 /* This is equivalent to C program below.
804 * The test is similar to delayed_iter_mark but verifies that incomplete
805 * precision don't fool verifier.
806 * The call to bpf_iter_num_next() is reachable with r7 values -16 and -32.
807 * State with r7=-16 is visited first and follows r6 != 42 ... continue branch.
808 * At this point iterator next() call is reached with r7 that has no read
809 * and precision marks.
810 * Loop body with r7=-32 would only be visited if verifier would decide to continue
811 * with second loop iteration. Absence of precision mark on r7 might affect state
812 * equivalent logic used for iterator convergence tracking.
813 *
814 * r8 = 0
815 * fp[-16] = 0
816 * r7 = -16
817 * r6 = bpf_get_prandom_u32()
818 * bpf_iter_num_new(&fp[-8], 0, 10)
819 * while (bpf_iter_num_next(&fp[-8])) {
820 * if (r6 != 42) {
821 * r7 = -32
822 * r6 = bpf_get_prandom_u32()
823 * continue;
824 * }
825 * r0 = r10
826 * r0 += r7
827 * r8 = *(u64 *)(r0 + 0) // this is not safe
828 * r6 = bpf_get_prandom_u32()
829 * }
830 * bpf_iter_num_destroy(&fp[-8])
831 * return r8
832 */
833 asm volatile (
834 "r8 = 0;"
835 "*(u64 *)(r10 - 16) = r8;"
836 "r7 = -16;"
837 "call %[bpf_get_prandom_u32];"
838 "r6 = r0;"
839 "r1 = r10;"
840 "r1 += -8;"
841 "r2 = 0;"
842 "r3 = 10;"
843 "call %[bpf_iter_num_new];"
844 "1:"
845 "r1 = r10;"
846 "r1 += -8;\n"
847 "call %[bpf_iter_num_next];"
848 "if r0 == 0 goto 2f;"
849 "if r6 != 42 goto 3f;"
850 "r7 = -33;"
851 "call %[bpf_get_prandom_u32];"
852 "r6 = r0;"
853 "goto 1b;\n"
854 "3:"
855 "r0 = r10;"
856 "r0 += r7;"
857 "r8 = *(u64 *)(r0 + 0);"
858 "call %[bpf_get_prandom_u32];"
859 "r6 = r0;"
860 "goto 1b;\n"
861 "2:"
862 "r1 = r10;"
863 "r1 += -8;"
864 "call %[bpf_iter_num_destroy];"
865 "r0 = r8;"
866 "exit;"
867 :
868 : __imm(bpf_get_prandom_u32),
869 __imm(bpf_iter_num_new),
870 __imm(bpf_iter_num_next),
871 __imm(bpf_iter_num_destroy),
872 __imm(bpf_probe_read_user)
873 : __clobber_all
874 );
875}
876
877SEC("?raw_tp")
878__failure
879__msg("math between fp pointer and register with unbounded")
880__flag(BPF_F_TEST_STATE_FREQ)
881__naked int loop_state_deps1(void)
882{
883 /* This is equivalent to C program below.
884 *
885 * The case turns out to be tricky in a sense that:
886 * - states with c=-25 are explored only on a second iteration
887 * of the outer loop;
888 * - states with read+precise mark on c are explored only on
889 * second iteration of the inner loop and in a state which
890 * is pushed to states stack first.
891 *
892 * Depending on the details of iterator convergence logic
893 * verifier might stop states traversal too early and miss
894 * unsafe c=-25 memory access.
895 *
896 * j = iter_new(); // fp[-16]
897 * a = 0; // r6
898 * b = 0; // r7
899 * c = -24; // r8
900 * while (iter_next(j)) {
901 * i = iter_new(); // fp[-8]
902 * a = 0; // r6
903 * b = 0; // r7
904 * while (iter_next(i)) {
905 * if (a == 1) {
906 * a = 0;
907 * b = 1;
908 * } else if (a == 0) {
909 * a = 1;
910 * if (random() == 42)
911 * continue;
912 * if (b == 1) {
913 * *(r10 + c) = 7; // this is not safe
914 * iter_destroy(i);
915 * iter_destroy(j);
916 * return;
917 * }
918 * }
919 * }
920 * iter_destroy(i);
921 * a = 0;
922 * b = 0;
923 * c = -25;
924 * }
925 * iter_destroy(j);
926 * return;
927 */
928 asm volatile (
929 "r1 = r10;"
930 "r1 += -16;"
931 "r2 = 0;"
932 "r3 = 10;"
933 "call %[bpf_iter_num_new];"
934 "r6 = 0;"
935 "r7 = 0;"
936 "r8 = -24;"
937 "j_loop_%=:"
938 "r1 = r10;"
939 "r1 += -16;"
940 "call %[bpf_iter_num_next];"
941 "if r0 == 0 goto j_loop_end_%=;"
942 "r1 = r10;"
943 "r1 += -8;"
944 "r2 = 0;"
945 "r3 = 10;"
946 "call %[bpf_iter_num_new];"
947 "r6 = 0;"
948 "r7 = 0;"
949 "i_loop_%=:"
950 "r1 = r10;"
951 "r1 += -8;"
952 "call %[bpf_iter_num_next];"
953 "if r0 == 0 goto i_loop_end_%=;"
954 "check_one_r6_%=:"
955 "if r6 != 1 goto check_zero_r6_%=;"
956 "r6 = 0;"
957 "r7 = 1;"
958 "goto i_loop_%=;"
959 "check_zero_r6_%=:"
960 "if r6 != 0 goto i_loop_%=;"
961 "r6 = 1;"
962 "call %[bpf_get_prandom_u32];"
963 "if r0 != 42 goto check_one_r7_%=;"
964 "goto i_loop_%=;"
965 "check_one_r7_%=:"
966 "if r7 != 1 goto i_loop_%=;"
967 "r0 = r10;"
968 "r0 += r8;"
969 "r1 = 7;"
970 "*(u64 *)(r0 + 0) = r1;"
971 "r1 = r10;"
972 "r1 += -8;"
973 "call %[bpf_iter_num_destroy];"
974 "r1 = r10;"
975 "r1 += -16;"
976 "call %[bpf_iter_num_destroy];"
977 "r0 = 0;"
978 "exit;"
979 "i_loop_end_%=:"
980 "r1 = r10;"
981 "r1 += -8;"
982 "call %[bpf_iter_num_destroy];"
983 "r6 = 0;"
984 "r7 = 0;"
985 "r8 = -25;"
986 "goto j_loop_%=;"
987 "j_loop_end_%=:"
988 "r1 = r10;"
989 "r1 += -16;"
990 "call %[bpf_iter_num_destroy];"
991 "r0 = 0;"
992 "exit;"
993 :
994 : __imm(bpf_get_prandom_u32),
995 __imm(bpf_iter_num_new),
996 __imm(bpf_iter_num_next),
997 __imm(bpf_iter_num_destroy)
998 : __clobber_all
999 );
1000}
1001
1002SEC("?raw_tp")
1003__failure
1004__msg("math between fp pointer and register with unbounded")
1005__flag(BPF_F_TEST_STATE_FREQ)
1006__naked int loop_state_deps2(void)
1007{
1008 /* This is equivalent to C program below.
1009 *
1010 * The case turns out to be tricky in a sense that:
1011 * - states with read+precise mark on c are explored only on a second
1012 * iteration of the first inner loop and in a state which is pushed to
1013 * states stack first.
1014 * - states with c=-25 are explored only on a second iteration of the
1015 * second inner loop and in a state which is pushed to states stack
1016 * first.
1017 *
1018 * Depending on the details of iterator convergence logic
1019 * verifier might stop states traversal too early and miss
1020 * unsafe c=-25 memory access.
1021 *
1022 * j = iter_new(); // fp[-16]
1023 * a = 0; // r6
1024 * b = 0; // r7
1025 * c = -24; // r8
1026 * while (iter_next(j)) {
1027 * i = iter_new(); // fp[-8]
1028 * a = 0; // r6
1029 * b = 0; // r7
1030 * while (iter_next(i)) {
1031 * if (a == 1) {
1032 * a = 0;
1033 * b = 1;
1034 * } else if (a == 0) {
1035 * a = 1;
1036 * if (random() == 42)
1037 * continue;
1038 * if (b == 1) {
1039 * *(r10 + c) = 7; // this is not safe
1040 * iter_destroy(i);
1041 * iter_destroy(j);
1042 * return;
1043 * }
1044 * }
1045 * }
1046 * iter_destroy(i);
1047 * i = iter_new(); // fp[-8]
1048 * a = 0; // r6
1049 * b = 0; // r7
1050 * while (iter_next(i)) {
1051 * if (a == 1) {
1052 * a = 0;
1053 * b = 1;
1054 * } else if (a == 0) {
1055 * a = 1;
1056 * if (random() == 42)
1057 * continue;
1058 * if (b == 1) {
1059 * a = 0;
1060 * c = -25;
1061 * }
1062 * }
1063 * }
1064 * iter_destroy(i);
1065 * }
1066 * iter_destroy(j);
1067 * return;
1068 */
1069 asm volatile (
1070 "r1 = r10;"
1071 "r1 += -16;"
1072 "r2 = 0;"
1073 "r3 = 10;"
1074 "call %[bpf_iter_num_new];"
1075 "r6 = 0;"
1076 "r7 = 0;"
1077 "r8 = -24;"
1078 "j_loop_%=:"
1079 "r1 = r10;"
1080 "r1 += -16;"
1081 "call %[bpf_iter_num_next];"
1082 "if r0 == 0 goto j_loop_end_%=;"
1083
1084 /* first inner loop */
1085 "r1 = r10;"
1086 "r1 += -8;"
1087 "r2 = 0;"
1088 "r3 = 10;"
1089 "call %[bpf_iter_num_new];"
1090 "r6 = 0;"
1091 "r7 = 0;"
1092 "i_loop_%=:"
1093 "r1 = r10;"
1094 "r1 += -8;"
1095 "call %[bpf_iter_num_next];"
1096 "if r0 == 0 goto i_loop_end_%=;"
1097 "check_one_r6_%=:"
1098 "if r6 != 1 goto check_zero_r6_%=;"
1099 "r6 = 0;"
1100 "r7 = 1;"
1101 "goto i_loop_%=;"
1102 "check_zero_r6_%=:"
1103 "if r6 != 0 goto i_loop_%=;"
1104 "r6 = 1;"
1105 "call %[bpf_get_prandom_u32];"
1106 "if r0 != 42 goto check_one_r7_%=;"
1107 "goto i_loop_%=;"
1108 "check_one_r7_%=:"
1109 "if r7 != 1 goto i_loop_%=;"
1110 "r0 = r10;"
1111 "r0 += r8;"
1112 "r1 = 7;"
1113 "*(u64 *)(r0 + 0) = r1;"
1114 "r1 = r10;"
1115 "r1 += -8;"
1116 "call %[bpf_iter_num_destroy];"
1117 "r1 = r10;"
1118 "r1 += -16;"
1119 "call %[bpf_iter_num_destroy];"
1120 "r0 = 0;"
1121 "exit;"
1122 "i_loop_end_%=:"
1123 "r1 = r10;"
1124 "r1 += -8;"
1125 "call %[bpf_iter_num_destroy];"
1126
1127 /* second inner loop */
1128 "r1 = r10;"
1129 "r1 += -8;"
1130 "r2 = 0;"
1131 "r3 = 10;"
1132 "call %[bpf_iter_num_new];"
1133 "r6 = 0;"
1134 "r7 = 0;"
1135 "i2_loop_%=:"
1136 "r1 = r10;"
1137 "r1 += -8;"
1138 "call %[bpf_iter_num_next];"
1139 "if r0 == 0 goto i2_loop_end_%=;"
1140 "check2_one_r6_%=:"
1141 "if r6 != 1 goto check2_zero_r6_%=;"
1142 "r6 = 0;"
1143 "r7 = 1;"
1144 "goto i2_loop_%=;"
1145 "check2_zero_r6_%=:"
1146 "if r6 != 0 goto i2_loop_%=;"
1147 "r6 = 1;"
1148 "call %[bpf_get_prandom_u32];"
1149 "if r0 != 42 goto check2_one_r7_%=;"
1150 "goto i2_loop_%=;"
1151 "check2_one_r7_%=:"
1152 "if r7 != 1 goto i2_loop_%=;"
1153 "r6 = 0;"
1154 "r8 = -25;"
1155 "goto i2_loop_%=;"
1156 "i2_loop_end_%=:"
1157 "r1 = r10;"
1158 "r1 += -8;"
1159 "call %[bpf_iter_num_destroy];"
1160
1161 "r6 = 0;"
1162 "r7 = 0;"
1163 "goto j_loop_%=;"
1164 "j_loop_end_%=:"
1165 "r1 = r10;"
1166 "r1 += -16;"
1167 "call %[bpf_iter_num_destroy];"
1168 "r0 = 0;"
1169 "exit;"
1170 :
1171 : __imm(bpf_get_prandom_u32),
1172 __imm(bpf_iter_num_new),
1173 __imm(bpf_iter_num_next),
1174 __imm(bpf_iter_num_destroy)
1175 : __clobber_all
1176 );
1177}
1178
1179SEC("?raw_tp")
1180__success
1181__naked int triple_continue(void)
1182{
1183 /* This is equivalent to C program below.
1184 * High branching factor of the loop body turned out to be
1185 * problematic for one of the iterator convergence tracking
1186 * algorithms explored.
1187 *
1188 * r6 = bpf_get_prandom_u32()
1189 * bpf_iter_num_new(&fp[-8], 0, 10)
1190 * while (bpf_iter_num_next(&fp[-8])) {
1191 * if (bpf_get_prandom_u32() != 42)
1192 * continue;
1193 * if (bpf_get_prandom_u32() != 42)
1194 * continue;
1195 * if (bpf_get_prandom_u32() != 42)
1196 * continue;
1197 * r0 += 0;
1198 * }
1199 * bpf_iter_num_destroy(&fp[-8])
1200 * return 0
1201 */
1202 asm volatile (
1203 "r1 = r10;"
1204 "r1 += -8;"
1205 "r2 = 0;"
1206 "r3 = 10;"
1207 "call %[bpf_iter_num_new];"
1208 "loop_%=:"
1209 "r1 = r10;"
1210 "r1 += -8;"
1211 "call %[bpf_iter_num_next];"
1212 "if r0 == 0 goto loop_end_%=;"
1213 "call %[bpf_get_prandom_u32];"
1214 "if r0 != 42 goto loop_%=;"
1215 "call %[bpf_get_prandom_u32];"
1216 "if r0 != 42 goto loop_%=;"
1217 "call %[bpf_get_prandom_u32];"
1218 "if r0 != 42 goto loop_%=;"
1219 "r0 += 0;"
1220 "goto loop_%=;"
1221 "loop_end_%=:"
1222 "r1 = r10;"
1223 "r1 += -8;"
1224 "call %[bpf_iter_num_destroy];"
1225 "r0 = 0;"
1226 "exit;"
1227 :
1228 : __imm(bpf_get_prandom_u32),
1229 __imm(bpf_iter_num_new),
1230 __imm(bpf_iter_num_next),
1231 __imm(bpf_iter_num_destroy)
1232 : __clobber_all
1233 );
1234}
1235
1236SEC("?raw_tp")
1237__success
1238__naked int widen_spill(void)
1239{
1240 /* This is equivalent to C program below.
1241 * The counter is stored in fp[-16], if this counter is not widened
1242 * verifier states representing loop iterations would never converge.
1243 *
1244 * fp[-16] = 0
1245 * bpf_iter_num_new(&fp[-8], 0, 10)
1246 * while (bpf_iter_num_next(&fp[-8])) {
1247 * r0 = fp[-16];
1248 * r0 += 1;
1249 * fp[-16] = r0;
1250 * }
1251 * bpf_iter_num_destroy(&fp[-8])
1252 * return 0
1253 */
1254 asm volatile (
1255 "r0 = 0;"
1256 "*(u64 *)(r10 - 16) = r0;"
1257 "r1 = r10;"
1258 "r1 += -8;"
1259 "r2 = 0;"
1260 "r3 = 10;"
1261 "call %[bpf_iter_num_new];"
1262 "loop_%=:"
1263 "r1 = r10;"
1264 "r1 += -8;"
1265 "call %[bpf_iter_num_next];"
1266 "if r0 == 0 goto loop_end_%=;"
1267 "r0 = *(u64 *)(r10 - 16);"
1268 "r0 += 1;"
1269 "*(u64 *)(r10 - 16) = r0;"
1270 "goto loop_%=;"
1271 "loop_end_%=:"
1272 "r1 = r10;"
1273 "r1 += -8;"
1274 "call %[bpf_iter_num_destroy];"
1275 "r0 = 0;"
1276 "exit;"
1277 :
1278 : __imm(bpf_iter_num_new),
1279 __imm(bpf_iter_num_next),
1280 __imm(bpf_iter_num_destroy)
1281 : __clobber_all
1282 );
1283}
1284
1285SEC("raw_tp")
1286__success
1287__naked int checkpoint_states_deletion(void)
1288{
1289 /* This is equivalent to C program below.
1290 *
1291 * int *a, *b, *c, *d, *e, *f;
1292 * int i, sum = 0;
1293 * bpf_for(i, 0, 10) {
1294 * a = bpf_map_lookup_elem(&amap, &i);
1295 * b = bpf_map_lookup_elem(&amap, &i);
1296 * c = bpf_map_lookup_elem(&amap, &i);
1297 * d = bpf_map_lookup_elem(&amap, &i);
1298 * e = bpf_map_lookup_elem(&amap, &i);
1299 * f = bpf_map_lookup_elem(&amap, &i);
1300 * if (a) sum += 1;
1301 * if (b) sum += 1;
1302 * if (c) sum += 1;
1303 * if (d) sum += 1;
1304 * if (e) sum += 1;
1305 * if (f) sum += 1;
1306 * }
1307 * return 0;
1308 *
1309 * The body of the loop spawns multiple simulation paths
1310 * with different combination of NULL/non-NULL information for a/b/c/d/e/f.
1311 * Each combination is unique from states_equal() point of view.
1312 * Explored states checkpoint is created after each iterator next call.
1313 * Iterator convergence logic expects that eventually current state
1314 * would get equal to one of the explored states and thus loop
1315 * exploration would be finished (at-least for a specific path).
1316 * Verifier evicts explored states with high miss to hit ratio
1317 * to to avoid comparing current state with too many explored
1318 * states per instruction.
1319 * This test is designed to "stress test" eviction policy defined using formula:
1320 *
1321 * sl->miss_cnt > sl->hit_cnt * N + N // if true sl->state is evicted
1322 *
1323 * Currently N is set to 64, which allows for 6 variables in this test.
1324 */
1325 asm volatile (
1326 "r6 = 0;" /* a */
1327 "r7 = 0;" /* b */
1328 "r8 = 0;" /* c */
1329 "*(u64 *)(r10 - 24) = r6;" /* d */
1330 "*(u64 *)(r10 - 32) = r6;" /* e */
1331 "*(u64 *)(r10 - 40) = r6;" /* f */
1332 "r9 = 0;" /* sum */
1333 "r1 = r10;"
1334 "r1 += -8;"
1335 "r2 = 0;"
1336 "r3 = 10;"
1337 "call %[bpf_iter_num_new];"
1338 "loop_%=:"
1339 "r1 = r10;"
1340 "r1 += -8;"
1341 "call %[bpf_iter_num_next];"
1342 "if r0 == 0 goto loop_end_%=;"
1343
1344 "*(u64 *)(r10 - 16) = r0;"
1345
1346 "r1 = %[amap] ll;"
1347 "r2 = r10;"
1348 "r2 += -16;"
1349 "call %[bpf_map_lookup_elem];"
1350 "r6 = r0;"
1351
1352 "r1 = %[amap] ll;"
1353 "r2 = r10;"
1354 "r2 += -16;"
1355 "call %[bpf_map_lookup_elem];"
1356 "r7 = r0;"
1357
1358 "r1 = %[amap] ll;"
1359 "r2 = r10;"
1360 "r2 += -16;"
1361 "call %[bpf_map_lookup_elem];"
1362 "r8 = r0;"
1363
1364 "r1 = %[amap] ll;"
1365 "r2 = r10;"
1366 "r2 += -16;"
1367 "call %[bpf_map_lookup_elem];"
1368 "*(u64 *)(r10 - 24) = r0;"
1369
1370 "r1 = %[amap] ll;"
1371 "r2 = r10;"
1372 "r2 += -16;"
1373 "call %[bpf_map_lookup_elem];"
1374 "*(u64 *)(r10 - 32) = r0;"
1375
1376 "r1 = %[amap] ll;"
1377 "r2 = r10;"
1378 "r2 += -16;"
1379 "call %[bpf_map_lookup_elem];"
1380 "*(u64 *)(r10 - 40) = r0;"
1381
1382 "if r6 == 0 goto +1;"
1383 "r9 += 1;"
1384 "if r7 == 0 goto +1;"
1385 "r9 += 1;"
1386 "if r8 == 0 goto +1;"
1387 "r9 += 1;"
1388 "r0 = *(u64 *)(r10 - 24);"
1389 "if r0 == 0 goto +1;"
1390 "r9 += 1;"
1391 "r0 = *(u64 *)(r10 - 32);"
1392 "if r0 == 0 goto +1;"
1393 "r9 += 1;"
1394 "r0 = *(u64 *)(r10 - 40);"
1395 "if r0 == 0 goto +1;"
1396 "r9 += 1;"
1397
1398 "goto loop_%=;"
1399 "loop_end_%=:"
1400 "r1 = r10;"
1401 "r1 += -8;"
1402 "call %[bpf_iter_num_destroy];"
1403 "r0 = 0;"
1404 "exit;"
1405 :
1406 : __imm(bpf_map_lookup_elem),
1407 __imm(bpf_iter_num_new),
1408 __imm(bpf_iter_num_next),
1409 __imm(bpf_iter_num_destroy),
1410 __imm_addr(amap)
1411 : __clobber_all
1412 );
1413}
1414
1415struct {
1416 int data[32];
1417 int n;
1418} loop_data;
1419
1420SEC("raw_tp")
1421__success
1422int iter_arr_with_actual_elem_count(const void *ctx)
1423{
1424 int i, n = loop_data.n, sum = 0;
1425
1426 if (n > ARRAY_SIZE(loop_data.data))
1427 return 0;
1428
1429 bpf_for(i, 0, n) {
1430 /* no rechecking of i against ARRAY_SIZE(loop_data.n) */
1431 sum += loop_data.data[i];
1432 }
1433
1434 return sum;
1435}
1436
1437char _license[] SEC("license") = "GPL";
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
3
4#include <stdbool.h>
5#include <linux/bpf.h>
6#include <bpf/bpf_helpers.h>
7#include "bpf_misc.h"
8
9#define ARRAY_SIZE(x) (int)(sizeof(x) / sizeof((x)[0]))
10
11static volatile int zero = 0;
12
13int my_pid;
14int arr[256];
15int small_arr[16] SEC(".data.small_arr");
16
17struct {
18 __uint(type, BPF_MAP_TYPE_HASH);
19 __uint(max_entries, 10);
20 __type(key, int);
21 __type(value, int);
22} amap SEC(".maps");
23
24#ifdef REAL_TEST
25#define MY_PID_GUARD() if (my_pid != (bpf_get_current_pid_tgid() >> 32)) return 0
26#else
27#define MY_PID_GUARD() ({ })
28#endif
29
30SEC("?raw_tp")
31__failure __msg("math between map_value pointer and register with unbounded min value is not allowed")
32int iter_err_unsafe_c_loop(const void *ctx)
33{
34 struct bpf_iter_num it;
35 int *v, i = zero; /* obscure initial value of i */
36
37 MY_PID_GUARD();
38
39 bpf_iter_num_new(&it, 0, 1000);
40 while ((v = bpf_iter_num_next(&it))) {
41 i++;
42 }
43 bpf_iter_num_destroy(&it);
44
45 small_arr[i] = 123; /* invalid */
46
47 return 0;
48}
49
50SEC("?raw_tp")
51__failure __msg("unbounded memory access")
52int iter_err_unsafe_asm_loop(const void *ctx)
53{
54 struct bpf_iter_num it;
55
56 MY_PID_GUARD();
57
58 asm volatile (
59 "r6 = %[zero];" /* iteration counter */
60 "r1 = %[it];" /* iterator state */
61 "r2 = 0;"
62 "r3 = 1000;"
63 "r4 = 1;"
64 "call %[bpf_iter_num_new];"
65 "loop:"
66 "r1 = %[it];"
67 "call %[bpf_iter_num_next];"
68 "if r0 == 0 goto out;"
69 "r6 += 1;"
70 "goto loop;"
71 "out:"
72 "r1 = %[it];"
73 "call %[bpf_iter_num_destroy];"
74 "r1 = %[small_arr];"
75 "r2 = r6;"
76 "r2 <<= 2;"
77 "r1 += r2;"
78 "*(u32 *)(r1 + 0) = r6;" /* invalid */
79 :
80 : [it]"r"(&it),
81 [small_arr]"p"(small_arr),
82 [zero]"p"(zero),
83 __imm(bpf_iter_num_new),
84 __imm(bpf_iter_num_next),
85 __imm(bpf_iter_num_destroy)
86 : __clobber_common, "r6"
87 );
88
89 return 0;
90}
91
92SEC("raw_tp")
93__success
94int iter_while_loop(const void *ctx)
95{
96 struct bpf_iter_num it;
97 int *v;
98
99 MY_PID_GUARD();
100
101 bpf_iter_num_new(&it, 0, 3);
102 while ((v = bpf_iter_num_next(&it))) {
103 bpf_printk("ITER_BASIC: E1 VAL: v=%d", *v);
104 }
105 bpf_iter_num_destroy(&it);
106
107 return 0;
108}
109
110SEC("raw_tp")
111__success
112int iter_while_loop_auto_cleanup(const void *ctx)
113{
114 __attribute__((cleanup(bpf_iter_num_destroy))) struct bpf_iter_num it;
115 int *v;
116
117 MY_PID_GUARD();
118
119 bpf_iter_num_new(&it, 0, 3);
120 while ((v = bpf_iter_num_next(&it))) {
121 bpf_printk("ITER_BASIC: E1 VAL: v=%d", *v);
122 }
123 /* (!) no explicit bpf_iter_num_destroy() */
124
125 return 0;
126}
127
128SEC("raw_tp")
129__success
130int iter_for_loop(const void *ctx)
131{
132 struct bpf_iter_num it;
133 int *v;
134
135 MY_PID_GUARD();
136
137 bpf_iter_num_new(&it, 5, 10);
138 for (v = bpf_iter_num_next(&it); v; v = bpf_iter_num_next(&it)) {
139 bpf_printk("ITER_BASIC: E2 VAL: v=%d", *v);
140 }
141 bpf_iter_num_destroy(&it);
142
143 return 0;
144}
145
146SEC("raw_tp")
147__success
148int iter_bpf_for_each_macro(const void *ctx)
149{
150 int *v;
151
152 MY_PID_GUARD();
153
154 bpf_for_each(num, v, 5, 10) {
155 bpf_printk("ITER_BASIC: E2 VAL: v=%d", *v);
156 }
157
158 return 0;
159}
160
161SEC("raw_tp")
162__success
163int iter_bpf_for_macro(const void *ctx)
164{
165 int i;
166
167 MY_PID_GUARD();
168
169 bpf_for(i, 5, 10) {
170 bpf_printk("ITER_BASIC: E2 VAL: v=%d", i);
171 }
172
173 return 0;
174}
175
176SEC("raw_tp")
177__success
178int iter_pragma_unroll_loop(const void *ctx)
179{
180 struct bpf_iter_num it;
181 int *v, i;
182
183 MY_PID_GUARD();
184
185 bpf_iter_num_new(&it, 0, 2);
186#pragma nounroll
187 for (i = 0; i < 3; i++) {
188 v = bpf_iter_num_next(&it);
189 bpf_printk("ITER_BASIC: E3 VAL: i=%d v=%d", i, v ? *v : -1);
190 }
191 bpf_iter_num_destroy(&it);
192
193 return 0;
194}
195
196SEC("raw_tp")
197__success
198int iter_manual_unroll_loop(const void *ctx)
199{
200 struct bpf_iter_num it;
201 int *v;
202
203 MY_PID_GUARD();
204
205 bpf_iter_num_new(&it, 100, 200);
206 v = bpf_iter_num_next(&it);
207 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
208 v = bpf_iter_num_next(&it);
209 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
210 v = bpf_iter_num_next(&it);
211 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
212 v = bpf_iter_num_next(&it);
213 bpf_printk("ITER_BASIC: E4 VAL: v=%d\n", v ? *v : -1);
214 bpf_iter_num_destroy(&it);
215
216 return 0;
217}
218
219SEC("raw_tp")
220__success
221int iter_multiple_sequential_loops(const void *ctx)
222{
223 struct bpf_iter_num it;
224 int *v, i;
225
226 MY_PID_GUARD();
227
228 bpf_iter_num_new(&it, 0, 3);
229 while ((v = bpf_iter_num_next(&it))) {
230 bpf_printk("ITER_BASIC: E1 VAL: v=%d", *v);
231 }
232 bpf_iter_num_destroy(&it);
233
234 bpf_iter_num_new(&it, 5, 10);
235 for (v = bpf_iter_num_next(&it); v; v = bpf_iter_num_next(&it)) {
236 bpf_printk("ITER_BASIC: E2 VAL: v=%d", *v);
237 }
238 bpf_iter_num_destroy(&it);
239
240 bpf_iter_num_new(&it, 0, 2);
241#pragma nounroll
242 for (i = 0; i < 3; i++) {
243 v = bpf_iter_num_next(&it);
244 bpf_printk("ITER_BASIC: E3 VAL: i=%d v=%d", i, v ? *v : -1);
245 }
246 bpf_iter_num_destroy(&it);
247
248 bpf_iter_num_new(&it, 100, 200);
249 v = bpf_iter_num_next(&it);
250 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
251 v = bpf_iter_num_next(&it);
252 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
253 v = bpf_iter_num_next(&it);
254 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
255 v = bpf_iter_num_next(&it);
256 bpf_printk("ITER_BASIC: E4 VAL: v=%d\n", v ? *v : -1);
257 bpf_iter_num_destroy(&it);
258
259 return 0;
260}
261
262SEC("raw_tp")
263__success
264int iter_limit_cond_break_loop(const void *ctx)
265{
266 struct bpf_iter_num it;
267 int *v, i = 0, sum = 0;
268
269 MY_PID_GUARD();
270
271 bpf_iter_num_new(&it, 0, 10);
272 while ((v = bpf_iter_num_next(&it))) {
273 bpf_printk("ITER_SIMPLE: i=%d v=%d", i, *v);
274 sum += *v;
275
276 i++;
277 if (i > 3)
278 break;
279 }
280 bpf_iter_num_destroy(&it);
281
282 bpf_printk("ITER_SIMPLE: sum=%d\n", sum);
283
284 return 0;
285}
286
287SEC("raw_tp")
288__success
289int iter_obfuscate_counter(const void *ctx)
290{
291 struct bpf_iter_num it;
292 int *v, sum = 0;
293 /* Make i's initial value unknowable for verifier to prevent it from
294 * pruning if/else branch inside the loop body and marking i as precise.
295 */
296 int i = zero;
297
298 MY_PID_GUARD();
299
300 bpf_iter_num_new(&it, 0, 10);
301 while ((v = bpf_iter_num_next(&it))) {
302 int x;
303
304 i += 1;
305
306 /* If we initialized i as `int i = 0;` above, verifier would
307 * track that i becomes 1 on first iteration after increment
308 * above, and here verifier would eagerly prune else branch
309 * and mark i as precise, ruining open-coded iterator logic
310 * completely, as each next iteration would have a different
311 * *precise* value of i, and thus there would be no
312 * convergence of state. This would result in reaching maximum
313 * instruction limit, no matter what the limit is.
314 */
315 if (i == 1)
316 x = 123;
317 else
318 x = i * 3 + 1;
319
320 bpf_printk("ITER_OBFUSCATE_COUNTER: i=%d v=%d x=%d", i, *v, x);
321
322 sum += x;
323 }
324 bpf_iter_num_destroy(&it);
325
326 bpf_printk("ITER_OBFUSCATE_COUNTER: sum=%d\n", sum);
327
328 return 0;
329}
330
331SEC("raw_tp")
332__success
333int iter_search_loop(const void *ctx)
334{
335 struct bpf_iter_num it;
336 int *v, *elem = NULL;
337 bool found = false;
338
339 MY_PID_GUARD();
340
341 bpf_iter_num_new(&it, 0, 10);
342
343 while ((v = bpf_iter_num_next(&it))) {
344 bpf_printk("ITER_SEARCH_LOOP: v=%d", *v);
345
346 if (*v == 2) {
347 found = true;
348 elem = v;
349 barrier_var(elem);
350 }
351 }
352
353 /* should fail to verify if bpf_iter_num_destroy() is here */
354
355 if (found)
356 /* here found element will be wrong, we should have copied
357 * value to a variable, but here we want to make sure we can
358 * access memory after the loop anyways
359 */
360 bpf_printk("ITER_SEARCH_LOOP: FOUND IT = %d!\n", *elem);
361 else
362 bpf_printk("ITER_SEARCH_LOOP: NOT FOUND IT!\n");
363
364 bpf_iter_num_destroy(&it);
365
366 return 0;
367}
368
369SEC("raw_tp")
370__success
371int iter_array_fill(const void *ctx)
372{
373 int sum, i;
374
375 MY_PID_GUARD();
376
377 bpf_for(i, 0, ARRAY_SIZE(arr)) {
378 arr[i] = i * 2;
379 }
380
381 sum = 0;
382 bpf_for(i, 0, ARRAY_SIZE(arr)) {
383 sum += arr[i];
384 }
385
386 bpf_printk("ITER_ARRAY_FILL: sum=%d (should be %d)\n", sum, 255 * 256);
387
388 return 0;
389}
390
391static int arr2d[4][5];
392static int arr2d_row_sums[4];
393static int arr2d_col_sums[5];
394
395SEC("raw_tp")
396__success
397int iter_nested_iters(const void *ctx)
398{
399 int sum, row, col;
400
401 MY_PID_GUARD();
402
403 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
404 bpf_for( col, 0, ARRAY_SIZE(arr2d[0])) {
405 arr2d[row][col] = row * col;
406 }
407 }
408
409 /* zero-initialize sums */
410 sum = 0;
411 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
412 arr2d_row_sums[row] = 0;
413 }
414 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
415 arr2d_col_sums[col] = 0;
416 }
417
418 /* calculate sums */
419 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
420 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
421 sum += arr2d[row][col];
422 arr2d_row_sums[row] += arr2d[row][col];
423 arr2d_col_sums[col] += arr2d[row][col];
424 }
425 }
426
427 bpf_printk("ITER_NESTED_ITERS: total sum=%d", sum);
428 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
429 bpf_printk("ITER_NESTED_ITERS: row #%d sum=%d", row, arr2d_row_sums[row]);
430 }
431 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
432 bpf_printk("ITER_NESTED_ITERS: col #%d sum=%d%s",
433 col, arr2d_col_sums[col],
434 col == ARRAY_SIZE(arr2d[0]) - 1 ? "\n" : "");
435 }
436
437 return 0;
438}
439
440SEC("raw_tp")
441__success
442int iter_nested_deeply_iters(const void *ctx)
443{
444 int sum = 0;
445
446 MY_PID_GUARD();
447
448 bpf_repeat(10) {
449 bpf_repeat(10) {
450 bpf_repeat(10) {
451 bpf_repeat(10) {
452 bpf_repeat(10) {
453 sum += 1;
454 }
455 }
456 }
457 }
458 /* validate that we can break from inside bpf_repeat() */
459 break;
460 }
461
462 return sum;
463}
464
465static __noinline void fill_inner_dimension(int row)
466{
467 int col;
468
469 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
470 arr2d[row][col] = row * col;
471 }
472}
473
474static __noinline int sum_inner_dimension(int row)
475{
476 int sum = 0, col;
477
478 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
479 sum += arr2d[row][col];
480 arr2d_row_sums[row] += arr2d[row][col];
481 arr2d_col_sums[col] += arr2d[row][col];
482 }
483
484 return sum;
485}
486
487SEC("raw_tp")
488__success
489int iter_subprog_iters(const void *ctx)
490{
491 int sum, row, col;
492
493 MY_PID_GUARD();
494
495 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
496 fill_inner_dimension(row);
497 }
498
499 /* zero-initialize sums */
500 sum = 0;
501 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
502 arr2d_row_sums[row] = 0;
503 }
504 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
505 arr2d_col_sums[col] = 0;
506 }
507
508 /* calculate sums */
509 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
510 sum += sum_inner_dimension(row);
511 }
512
513 bpf_printk("ITER_SUBPROG_ITERS: total sum=%d", sum);
514 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
515 bpf_printk("ITER_SUBPROG_ITERS: row #%d sum=%d",
516 row, arr2d_row_sums[row]);
517 }
518 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
519 bpf_printk("ITER_SUBPROG_ITERS: col #%d sum=%d%s",
520 col, arr2d_col_sums[col],
521 col == ARRAY_SIZE(arr2d[0]) - 1 ? "\n" : "");
522 }
523
524 return 0;
525}
526
527struct {
528 __uint(type, BPF_MAP_TYPE_ARRAY);
529 __type(key, int);
530 __type(value, int);
531 __uint(max_entries, 1000);
532} arr_map SEC(".maps");
533
534SEC("?raw_tp")
535__failure __msg("invalid mem access 'scalar'")
536int iter_err_too_permissive1(const void *ctx)
537{
538 int *map_val = NULL;
539 int key = 0;
540
541 MY_PID_GUARD();
542
543 map_val = bpf_map_lookup_elem(&arr_map, &key);
544 if (!map_val)
545 return 0;
546
547 bpf_repeat(1000000) {
548 map_val = NULL;
549 }
550
551 *map_val = 123;
552
553 return 0;
554}
555
556SEC("?raw_tp")
557__failure __msg("invalid mem access 'map_value_or_null'")
558int iter_err_too_permissive2(const void *ctx)
559{
560 int *map_val = NULL;
561 int key = 0;
562
563 MY_PID_GUARD();
564
565 map_val = bpf_map_lookup_elem(&arr_map, &key);
566 if (!map_val)
567 return 0;
568
569 bpf_repeat(1000000) {
570 map_val = bpf_map_lookup_elem(&arr_map, &key);
571 }
572
573 *map_val = 123;
574
575 return 0;
576}
577
578SEC("?raw_tp")
579__failure __msg("invalid mem access 'map_value_or_null'")
580int iter_err_too_permissive3(const void *ctx)
581{
582 int *map_val = NULL;
583 int key = 0;
584 bool found = false;
585
586 MY_PID_GUARD();
587
588 bpf_repeat(1000000) {
589 map_val = bpf_map_lookup_elem(&arr_map, &key);
590 found = true;
591 }
592
593 if (found)
594 *map_val = 123;
595
596 return 0;
597}
598
599SEC("raw_tp")
600__success
601int iter_tricky_but_fine(const void *ctx)
602{
603 int *map_val = NULL;
604 int key = 0;
605 bool found = false;
606
607 MY_PID_GUARD();
608
609 bpf_repeat(1000000) {
610 map_val = bpf_map_lookup_elem(&arr_map, &key);
611 if (map_val) {
612 found = true;
613 break;
614 }
615 }
616
617 if (found)
618 *map_val = 123;
619
620 return 0;
621}
622
623#define __bpf_memzero(p, sz) bpf_probe_read_kernel((p), (sz), 0)
624
625SEC("raw_tp")
626__success
627int iter_stack_array_loop(const void *ctx)
628{
629 long arr1[16], arr2[16], sum = 0;
630 int i;
631
632 MY_PID_GUARD();
633
634 /* zero-init arr1 and arr2 in such a way that verifier doesn't know
635 * it's all zeros; if we don't do that, we'll make BPF verifier track
636 * all combination of zero/non-zero stack slots for arr1/arr2, which
637 * will lead to O(2^(ARRAY_SIZE(arr1)+ARRAY_SIZE(arr2))) different
638 * states
639 */
640 __bpf_memzero(arr1, sizeof(arr1));
641 __bpf_memzero(arr2, sizeof(arr1));
642
643 /* validate that we can break and continue when using bpf_for() */
644 bpf_for(i, 0, ARRAY_SIZE(arr1)) {
645 if (i & 1) {
646 arr1[i] = i;
647 continue;
648 } else {
649 arr2[i] = i;
650 break;
651 }
652 }
653
654 bpf_for(i, 0, ARRAY_SIZE(arr1)) {
655 sum += arr1[i] + arr2[i];
656 }
657
658 return sum;
659}
660
661static __noinline void fill(struct bpf_iter_num *it, int *arr, __u32 n, int mul)
662{
663 int *t, i;
664
665 while ((t = bpf_iter_num_next(it))) {
666 i = *t;
667 if (i >= n)
668 break;
669 arr[i] = i * mul;
670 }
671}
672
673static __noinline int sum(struct bpf_iter_num *it, int *arr, __u32 n)
674{
675 int *t, i, sum = 0;;
676
677 while ((t = bpf_iter_num_next(it))) {
678 i = *t;
679 if ((__u32)i >= n)
680 break;
681 sum += arr[i];
682 }
683
684 return sum;
685}
686
687SEC("raw_tp")
688__success
689int iter_pass_iter_ptr_to_subprog(const void *ctx)
690{
691 int arr1[16], arr2[32];
692 struct bpf_iter_num it;
693 int n, sum1, sum2;
694
695 MY_PID_GUARD();
696
697 /* fill arr1 */
698 n = ARRAY_SIZE(arr1);
699 bpf_iter_num_new(&it, 0, n);
700 fill(&it, arr1, n, 2);
701 bpf_iter_num_destroy(&it);
702
703 /* fill arr2 */
704 n = ARRAY_SIZE(arr2);
705 bpf_iter_num_new(&it, 0, n);
706 fill(&it, arr2, n, 10);
707 bpf_iter_num_destroy(&it);
708
709 /* sum arr1 */
710 n = ARRAY_SIZE(arr1);
711 bpf_iter_num_new(&it, 0, n);
712 sum1 = sum(&it, arr1, n);
713 bpf_iter_num_destroy(&it);
714
715 /* sum arr2 */
716 n = ARRAY_SIZE(arr2);
717 bpf_iter_num_new(&it, 0, n);
718 sum2 = sum(&it, arr2, n);
719 bpf_iter_num_destroy(&it);
720
721 bpf_printk("sum1=%d, sum2=%d", sum1, sum2);
722
723 return 0;
724}
725
726SEC("?raw_tp")
727__failure
728__msg("R1 type=scalar expected=fp")
729__naked int delayed_read_mark(void)
730{
731 /* This is equivalent to C program below.
732 * The call to bpf_iter_num_next() is reachable with r7 values &fp[-16] and 0xdead.
733 * State with r7=&fp[-16] is visited first and follows r6 != 42 ... continue branch.
734 * At this point iterator next() call is reached with r7 that has no read mark.
735 * Loop body with r7=0xdead would only be visited if verifier would decide to continue
736 * with second loop iteration. Absence of read mark on r7 might affect state
737 * equivalent logic used for iterator convergence tracking.
738 *
739 * r7 = &fp[-16]
740 * fp[-16] = 0
741 * r6 = bpf_get_prandom_u32()
742 * bpf_iter_num_new(&fp[-8], 0, 10)
743 * while (bpf_iter_num_next(&fp[-8])) {
744 * r6++
745 * if (r6 != 42) {
746 * r7 = 0xdead
747 * continue;
748 * }
749 * bpf_probe_read_user(r7, 8, 0xdeadbeef); // this is not safe
750 * }
751 * bpf_iter_num_destroy(&fp[-8])
752 * return 0
753 */
754 asm volatile (
755 "r7 = r10;"
756 "r7 += -16;"
757 "r0 = 0;"
758 "*(u64 *)(r7 + 0) = r0;"
759 "call %[bpf_get_prandom_u32];"
760 "r6 = r0;"
761 "r1 = r10;"
762 "r1 += -8;"
763 "r2 = 0;"
764 "r3 = 10;"
765 "call %[bpf_iter_num_new];"
766 "1:"
767 "r1 = r10;"
768 "r1 += -8;"
769 "call %[bpf_iter_num_next];"
770 "if r0 == 0 goto 2f;"
771 "r6 += 1;"
772 "if r6 != 42 goto 3f;"
773 "r7 = 0xdead;"
774 "goto 1b;"
775 "3:"
776 "r1 = r7;"
777 "r2 = 8;"
778 "r3 = 0xdeadbeef;"
779 "call %[bpf_probe_read_user];"
780 "goto 1b;"
781 "2:"
782 "r1 = r10;"
783 "r1 += -8;"
784 "call %[bpf_iter_num_destroy];"
785 "r0 = 0;"
786 "exit;"
787 :
788 : __imm(bpf_get_prandom_u32),
789 __imm(bpf_iter_num_new),
790 __imm(bpf_iter_num_next),
791 __imm(bpf_iter_num_destroy),
792 __imm(bpf_probe_read_user)
793 : __clobber_all
794 );
795}
796
797SEC("?raw_tp")
798__failure
799__msg("math between fp pointer and register with unbounded")
800__naked int delayed_precision_mark(void)
801{
802 /* This is equivalent to C program below.
803 * The test is similar to delayed_iter_mark but verifies that incomplete
804 * precision don't fool verifier.
805 * The call to bpf_iter_num_next() is reachable with r7 values -16 and -32.
806 * State with r7=-16 is visited first and follows r6 != 42 ... continue branch.
807 * At this point iterator next() call is reached with r7 that has no read
808 * and precision marks.
809 * Loop body with r7=-32 would only be visited if verifier would decide to continue
810 * with second loop iteration. Absence of precision mark on r7 might affect state
811 * equivalent logic used for iterator convergence tracking.
812 *
813 * r8 = 0
814 * fp[-16] = 0
815 * r7 = -16
816 * r6 = bpf_get_prandom_u32()
817 * bpf_iter_num_new(&fp[-8], 0, 10)
818 * while (bpf_iter_num_next(&fp[-8])) {
819 * if (r6 != 42) {
820 * r7 = -32
821 * r6 = bpf_get_prandom_u32()
822 * continue;
823 * }
824 * r0 = r10
825 * r0 += r7
826 * r8 = *(u64 *)(r0 + 0) // this is not safe
827 * r6 = bpf_get_prandom_u32()
828 * }
829 * bpf_iter_num_destroy(&fp[-8])
830 * return r8
831 */
832 asm volatile (
833 "r8 = 0;"
834 "*(u64 *)(r10 - 16) = r8;"
835 "r7 = -16;"
836 "call %[bpf_get_prandom_u32];"
837 "r6 = r0;"
838 "r1 = r10;"
839 "r1 += -8;"
840 "r2 = 0;"
841 "r3 = 10;"
842 "call %[bpf_iter_num_new];"
843 "1:"
844 "r1 = r10;"
845 "r1 += -8;\n"
846 "call %[bpf_iter_num_next];"
847 "if r0 == 0 goto 2f;"
848 "if r6 != 42 goto 3f;"
849 "r7 = -33;"
850 "call %[bpf_get_prandom_u32];"
851 "r6 = r0;"
852 "goto 1b;\n"
853 "3:"
854 "r0 = r10;"
855 "r0 += r7;"
856 "r8 = *(u64 *)(r0 + 0);"
857 "call %[bpf_get_prandom_u32];"
858 "r6 = r0;"
859 "goto 1b;\n"
860 "2:"
861 "r1 = r10;"
862 "r1 += -8;"
863 "call %[bpf_iter_num_destroy];"
864 "r0 = r8;"
865 "exit;"
866 :
867 : __imm(bpf_get_prandom_u32),
868 __imm(bpf_iter_num_new),
869 __imm(bpf_iter_num_next),
870 __imm(bpf_iter_num_destroy),
871 __imm(bpf_probe_read_user)
872 : __clobber_all
873 );
874}
875
876SEC("?raw_tp")
877__failure
878__msg("math between fp pointer and register with unbounded")
879__flag(BPF_F_TEST_STATE_FREQ)
880__naked int loop_state_deps1(void)
881{
882 /* This is equivalent to C program below.
883 *
884 * The case turns out to be tricky in a sense that:
885 * - states with c=-25 are explored only on a second iteration
886 * of the outer loop;
887 * - states with read+precise mark on c are explored only on
888 * second iteration of the inner loop and in a state which
889 * is pushed to states stack first.
890 *
891 * Depending on the details of iterator convergence logic
892 * verifier might stop states traversal too early and miss
893 * unsafe c=-25 memory access.
894 *
895 * j = iter_new(); // fp[-16]
896 * a = 0; // r6
897 * b = 0; // r7
898 * c = -24; // r8
899 * while (iter_next(j)) {
900 * i = iter_new(); // fp[-8]
901 * a = 0; // r6
902 * b = 0; // r7
903 * while (iter_next(i)) {
904 * if (a == 1) {
905 * a = 0;
906 * b = 1;
907 * } else if (a == 0) {
908 * a = 1;
909 * if (random() == 42)
910 * continue;
911 * if (b == 1) {
912 * *(r10 + c) = 7; // this is not safe
913 * iter_destroy(i);
914 * iter_destroy(j);
915 * return;
916 * }
917 * }
918 * }
919 * iter_destroy(i);
920 * a = 0;
921 * b = 0;
922 * c = -25;
923 * }
924 * iter_destroy(j);
925 * return;
926 */
927 asm volatile (
928 "r1 = r10;"
929 "r1 += -16;"
930 "r2 = 0;"
931 "r3 = 10;"
932 "call %[bpf_iter_num_new];"
933 "r6 = 0;"
934 "r7 = 0;"
935 "r8 = -24;"
936 "j_loop_%=:"
937 "r1 = r10;"
938 "r1 += -16;"
939 "call %[bpf_iter_num_next];"
940 "if r0 == 0 goto j_loop_end_%=;"
941 "r1 = r10;"
942 "r1 += -8;"
943 "r2 = 0;"
944 "r3 = 10;"
945 "call %[bpf_iter_num_new];"
946 "r6 = 0;"
947 "r7 = 0;"
948 "i_loop_%=:"
949 "r1 = r10;"
950 "r1 += -8;"
951 "call %[bpf_iter_num_next];"
952 "if r0 == 0 goto i_loop_end_%=;"
953 "check_one_r6_%=:"
954 "if r6 != 1 goto check_zero_r6_%=;"
955 "r6 = 0;"
956 "r7 = 1;"
957 "goto i_loop_%=;"
958 "check_zero_r6_%=:"
959 "if r6 != 0 goto i_loop_%=;"
960 "r6 = 1;"
961 "call %[bpf_get_prandom_u32];"
962 "if r0 != 42 goto check_one_r7_%=;"
963 "goto i_loop_%=;"
964 "check_one_r7_%=:"
965 "if r7 != 1 goto i_loop_%=;"
966 "r0 = r10;"
967 "r0 += r8;"
968 "r1 = 7;"
969 "*(u64 *)(r0 + 0) = r1;"
970 "r1 = r10;"
971 "r1 += -8;"
972 "call %[bpf_iter_num_destroy];"
973 "r1 = r10;"
974 "r1 += -16;"
975 "call %[bpf_iter_num_destroy];"
976 "r0 = 0;"
977 "exit;"
978 "i_loop_end_%=:"
979 "r1 = r10;"
980 "r1 += -8;"
981 "call %[bpf_iter_num_destroy];"
982 "r6 = 0;"
983 "r7 = 0;"
984 "r8 = -25;"
985 "goto j_loop_%=;"
986 "j_loop_end_%=:"
987 "r1 = r10;"
988 "r1 += -16;"
989 "call %[bpf_iter_num_destroy];"
990 "r0 = 0;"
991 "exit;"
992 :
993 : __imm(bpf_get_prandom_u32),
994 __imm(bpf_iter_num_new),
995 __imm(bpf_iter_num_next),
996 __imm(bpf_iter_num_destroy)
997 : __clobber_all
998 );
999}
1000
1001SEC("?raw_tp")
1002__failure
1003__msg("math between fp pointer and register with unbounded")
1004__flag(BPF_F_TEST_STATE_FREQ)
1005__naked int loop_state_deps2(void)
1006{
1007 /* This is equivalent to C program below.
1008 *
1009 * The case turns out to be tricky in a sense that:
1010 * - states with read+precise mark on c are explored only on a second
1011 * iteration of the first inner loop and in a state which is pushed to
1012 * states stack first.
1013 * - states with c=-25 are explored only on a second iteration of the
1014 * second inner loop and in a state which is pushed to states stack
1015 * first.
1016 *
1017 * Depending on the details of iterator convergence logic
1018 * verifier might stop states traversal too early and miss
1019 * unsafe c=-25 memory access.
1020 *
1021 * j = iter_new(); // fp[-16]
1022 * a = 0; // r6
1023 * b = 0; // r7
1024 * c = -24; // r8
1025 * while (iter_next(j)) {
1026 * i = iter_new(); // fp[-8]
1027 * a = 0; // r6
1028 * b = 0; // r7
1029 * while (iter_next(i)) {
1030 * if (a == 1) {
1031 * a = 0;
1032 * b = 1;
1033 * } else if (a == 0) {
1034 * a = 1;
1035 * if (random() == 42)
1036 * continue;
1037 * if (b == 1) {
1038 * *(r10 + c) = 7; // this is not safe
1039 * iter_destroy(i);
1040 * iter_destroy(j);
1041 * return;
1042 * }
1043 * }
1044 * }
1045 * iter_destroy(i);
1046 * i = iter_new(); // fp[-8]
1047 * a = 0; // r6
1048 * b = 0; // r7
1049 * while (iter_next(i)) {
1050 * if (a == 1) {
1051 * a = 0;
1052 * b = 1;
1053 * } else if (a == 0) {
1054 * a = 1;
1055 * if (random() == 42)
1056 * continue;
1057 * if (b == 1) {
1058 * a = 0;
1059 * c = -25;
1060 * }
1061 * }
1062 * }
1063 * iter_destroy(i);
1064 * }
1065 * iter_destroy(j);
1066 * return;
1067 */
1068 asm volatile (
1069 "r1 = r10;"
1070 "r1 += -16;"
1071 "r2 = 0;"
1072 "r3 = 10;"
1073 "call %[bpf_iter_num_new];"
1074 "r6 = 0;"
1075 "r7 = 0;"
1076 "r8 = -24;"
1077 "j_loop_%=:"
1078 "r1 = r10;"
1079 "r1 += -16;"
1080 "call %[bpf_iter_num_next];"
1081 "if r0 == 0 goto j_loop_end_%=;"
1082
1083 /* first inner loop */
1084 "r1 = r10;"
1085 "r1 += -8;"
1086 "r2 = 0;"
1087 "r3 = 10;"
1088 "call %[bpf_iter_num_new];"
1089 "r6 = 0;"
1090 "r7 = 0;"
1091 "i_loop_%=:"
1092 "r1 = r10;"
1093 "r1 += -8;"
1094 "call %[bpf_iter_num_next];"
1095 "if r0 == 0 goto i_loop_end_%=;"
1096 "check_one_r6_%=:"
1097 "if r6 != 1 goto check_zero_r6_%=;"
1098 "r6 = 0;"
1099 "r7 = 1;"
1100 "goto i_loop_%=;"
1101 "check_zero_r6_%=:"
1102 "if r6 != 0 goto i_loop_%=;"
1103 "r6 = 1;"
1104 "call %[bpf_get_prandom_u32];"
1105 "if r0 != 42 goto check_one_r7_%=;"
1106 "goto i_loop_%=;"
1107 "check_one_r7_%=:"
1108 "if r7 != 1 goto i_loop_%=;"
1109 "r0 = r10;"
1110 "r0 += r8;"
1111 "r1 = 7;"
1112 "*(u64 *)(r0 + 0) = r1;"
1113 "r1 = r10;"
1114 "r1 += -8;"
1115 "call %[bpf_iter_num_destroy];"
1116 "r1 = r10;"
1117 "r1 += -16;"
1118 "call %[bpf_iter_num_destroy];"
1119 "r0 = 0;"
1120 "exit;"
1121 "i_loop_end_%=:"
1122 "r1 = r10;"
1123 "r1 += -8;"
1124 "call %[bpf_iter_num_destroy];"
1125
1126 /* second inner loop */
1127 "r1 = r10;"
1128 "r1 += -8;"
1129 "r2 = 0;"
1130 "r3 = 10;"
1131 "call %[bpf_iter_num_new];"
1132 "r6 = 0;"
1133 "r7 = 0;"
1134 "i2_loop_%=:"
1135 "r1 = r10;"
1136 "r1 += -8;"
1137 "call %[bpf_iter_num_next];"
1138 "if r0 == 0 goto i2_loop_end_%=;"
1139 "check2_one_r6_%=:"
1140 "if r6 != 1 goto check2_zero_r6_%=;"
1141 "r6 = 0;"
1142 "r7 = 1;"
1143 "goto i2_loop_%=;"
1144 "check2_zero_r6_%=:"
1145 "if r6 != 0 goto i2_loop_%=;"
1146 "r6 = 1;"
1147 "call %[bpf_get_prandom_u32];"
1148 "if r0 != 42 goto check2_one_r7_%=;"
1149 "goto i2_loop_%=;"
1150 "check2_one_r7_%=:"
1151 "if r7 != 1 goto i2_loop_%=;"
1152 "r6 = 0;"
1153 "r8 = -25;"
1154 "goto i2_loop_%=;"
1155 "i2_loop_end_%=:"
1156 "r1 = r10;"
1157 "r1 += -8;"
1158 "call %[bpf_iter_num_destroy];"
1159
1160 "r6 = 0;"
1161 "r7 = 0;"
1162 "goto j_loop_%=;"
1163 "j_loop_end_%=:"
1164 "r1 = r10;"
1165 "r1 += -16;"
1166 "call %[bpf_iter_num_destroy];"
1167 "r0 = 0;"
1168 "exit;"
1169 :
1170 : __imm(bpf_get_prandom_u32),
1171 __imm(bpf_iter_num_new),
1172 __imm(bpf_iter_num_next),
1173 __imm(bpf_iter_num_destroy)
1174 : __clobber_all
1175 );
1176}
1177
1178SEC("?raw_tp")
1179__success
1180__naked int triple_continue(void)
1181{
1182 /* This is equivalent to C program below.
1183 * High branching factor of the loop body turned out to be
1184 * problematic for one of the iterator convergence tracking
1185 * algorithms explored.
1186 *
1187 * r6 = bpf_get_prandom_u32()
1188 * bpf_iter_num_new(&fp[-8], 0, 10)
1189 * while (bpf_iter_num_next(&fp[-8])) {
1190 * if (bpf_get_prandom_u32() != 42)
1191 * continue;
1192 * if (bpf_get_prandom_u32() != 42)
1193 * continue;
1194 * if (bpf_get_prandom_u32() != 42)
1195 * continue;
1196 * r0 += 0;
1197 * }
1198 * bpf_iter_num_destroy(&fp[-8])
1199 * return 0
1200 */
1201 asm volatile (
1202 "r1 = r10;"
1203 "r1 += -8;"
1204 "r2 = 0;"
1205 "r3 = 10;"
1206 "call %[bpf_iter_num_new];"
1207 "loop_%=:"
1208 "r1 = r10;"
1209 "r1 += -8;"
1210 "call %[bpf_iter_num_next];"
1211 "if r0 == 0 goto loop_end_%=;"
1212 "call %[bpf_get_prandom_u32];"
1213 "if r0 != 42 goto loop_%=;"
1214 "call %[bpf_get_prandom_u32];"
1215 "if r0 != 42 goto loop_%=;"
1216 "call %[bpf_get_prandom_u32];"
1217 "if r0 != 42 goto loop_%=;"
1218 "r0 += 0;"
1219 "goto loop_%=;"
1220 "loop_end_%=:"
1221 "r1 = r10;"
1222 "r1 += -8;"
1223 "call %[bpf_iter_num_destroy];"
1224 "r0 = 0;"
1225 "exit;"
1226 :
1227 : __imm(bpf_get_prandom_u32),
1228 __imm(bpf_iter_num_new),
1229 __imm(bpf_iter_num_next),
1230 __imm(bpf_iter_num_destroy)
1231 : __clobber_all
1232 );
1233}
1234
1235SEC("?raw_tp")
1236__success
1237__naked int widen_spill(void)
1238{
1239 /* This is equivalent to C program below.
1240 * The counter is stored in fp[-16], if this counter is not widened
1241 * verifier states representing loop iterations would never converge.
1242 *
1243 * fp[-16] = 0
1244 * bpf_iter_num_new(&fp[-8], 0, 10)
1245 * while (bpf_iter_num_next(&fp[-8])) {
1246 * r0 = fp[-16];
1247 * r0 += 1;
1248 * fp[-16] = r0;
1249 * }
1250 * bpf_iter_num_destroy(&fp[-8])
1251 * return 0
1252 */
1253 asm volatile (
1254 "r0 = 0;"
1255 "*(u64 *)(r10 - 16) = r0;"
1256 "r1 = r10;"
1257 "r1 += -8;"
1258 "r2 = 0;"
1259 "r3 = 10;"
1260 "call %[bpf_iter_num_new];"
1261 "loop_%=:"
1262 "r1 = r10;"
1263 "r1 += -8;"
1264 "call %[bpf_iter_num_next];"
1265 "if r0 == 0 goto loop_end_%=;"
1266 "r0 = *(u64 *)(r10 - 16);"
1267 "r0 += 1;"
1268 "*(u64 *)(r10 - 16) = r0;"
1269 "goto loop_%=;"
1270 "loop_end_%=:"
1271 "r1 = r10;"
1272 "r1 += -8;"
1273 "call %[bpf_iter_num_destroy];"
1274 "r0 = 0;"
1275 "exit;"
1276 :
1277 : __imm(bpf_iter_num_new),
1278 __imm(bpf_iter_num_next),
1279 __imm(bpf_iter_num_destroy)
1280 : __clobber_all
1281 );
1282}
1283
1284SEC("raw_tp")
1285__success
1286__naked int checkpoint_states_deletion(void)
1287{
1288 /* This is equivalent to C program below.
1289 *
1290 * int *a, *b, *c, *d, *e, *f;
1291 * int i, sum = 0;
1292 * bpf_for(i, 0, 10) {
1293 * a = bpf_map_lookup_elem(&amap, &i);
1294 * b = bpf_map_lookup_elem(&amap, &i);
1295 * c = bpf_map_lookup_elem(&amap, &i);
1296 * d = bpf_map_lookup_elem(&amap, &i);
1297 * e = bpf_map_lookup_elem(&amap, &i);
1298 * f = bpf_map_lookup_elem(&amap, &i);
1299 * if (a) sum += 1;
1300 * if (b) sum += 1;
1301 * if (c) sum += 1;
1302 * if (d) sum += 1;
1303 * if (e) sum += 1;
1304 * if (f) sum += 1;
1305 * }
1306 * return 0;
1307 *
1308 * The body of the loop spawns multiple simulation paths
1309 * with different combination of NULL/non-NULL information for a/b/c/d/e/f.
1310 * Each combination is unique from states_equal() point of view.
1311 * Explored states checkpoint is created after each iterator next call.
1312 * Iterator convergence logic expects that eventually current state
1313 * would get equal to one of the explored states and thus loop
1314 * exploration would be finished (at-least for a specific path).
1315 * Verifier evicts explored states with high miss to hit ratio
1316 * to to avoid comparing current state with too many explored
1317 * states per instruction.
1318 * This test is designed to "stress test" eviction policy defined using formula:
1319 *
1320 * sl->miss_cnt > sl->hit_cnt * N + N // if true sl->state is evicted
1321 *
1322 * Currently N is set to 64, which allows for 6 variables in this test.
1323 */
1324 asm volatile (
1325 "r6 = 0;" /* a */
1326 "r7 = 0;" /* b */
1327 "r8 = 0;" /* c */
1328 "*(u64 *)(r10 - 24) = r6;" /* d */
1329 "*(u64 *)(r10 - 32) = r6;" /* e */
1330 "*(u64 *)(r10 - 40) = r6;" /* f */
1331 "r9 = 0;" /* sum */
1332 "r1 = r10;"
1333 "r1 += -8;"
1334 "r2 = 0;"
1335 "r3 = 10;"
1336 "call %[bpf_iter_num_new];"
1337 "loop_%=:"
1338 "r1 = r10;"
1339 "r1 += -8;"
1340 "call %[bpf_iter_num_next];"
1341 "if r0 == 0 goto loop_end_%=;"
1342
1343 "*(u64 *)(r10 - 16) = r0;"
1344
1345 "r1 = %[amap] ll;"
1346 "r2 = r10;"
1347 "r2 += -16;"
1348 "call %[bpf_map_lookup_elem];"
1349 "r6 = r0;"
1350
1351 "r1 = %[amap] ll;"
1352 "r2 = r10;"
1353 "r2 += -16;"
1354 "call %[bpf_map_lookup_elem];"
1355 "r7 = r0;"
1356
1357 "r1 = %[amap] ll;"
1358 "r2 = r10;"
1359 "r2 += -16;"
1360 "call %[bpf_map_lookup_elem];"
1361 "r8 = r0;"
1362
1363 "r1 = %[amap] ll;"
1364 "r2 = r10;"
1365 "r2 += -16;"
1366 "call %[bpf_map_lookup_elem];"
1367 "*(u64 *)(r10 - 24) = r0;"
1368
1369 "r1 = %[amap] ll;"
1370 "r2 = r10;"
1371 "r2 += -16;"
1372 "call %[bpf_map_lookup_elem];"
1373 "*(u64 *)(r10 - 32) = r0;"
1374
1375 "r1 = %[amap] ll;"
1376 "r2 = r10;"
1377 "r2 += -16;"
1378 "call %[bpf_map_lookup_elem];"
1379 "*(u64 *)(r10 - 40) = r0;"
1380
1381 "if r6 == 0 goto +1;"
1382 "r9 += 1;"
1383 "if r7 == 0 goto +1;"
1384 "r9 += 1;"
1385 "if r8 == 0 goto +1;"
1386 "r9 += 1;"
1387 "r0 = *(u64 *)(r10 - 24);"
1388 "if r0 == 0 goto +1;"
1389 "r9 += 1;"
1390 "r0 = *(u64 *)(r10 - 32);"
1391 "if r0 == 0 goto +1;"
1392 "r9 += 1;"
1393 "r0 = *(u64 *)(r10 - 40);"
1394 "if r0 == 0 goto +1;"
1395 "r9 += 1;"
1396
1397 "goto loop_%=;"
1398 "loop_end_%=:"
1399 "r1 = r10;"
1400 "r1 += -8;"
1401 "call %[bpf_iter_num_destroy];"
1402 "r0 = 0;"
1403 "exit;"
1404 :
1405 : __imm(bpf_map_lookup_elem),
1406 __imm(bpf_iter_num_new),
1407 __imm(bpf_iter_num_next),
1408 __imm(bpf_iter_num_destroy),
1409 __imm_addr(amap)
1410 : __clobber_all
1411 );
1412}
1413
1414struct {
1415 int data[32];
1416 int n;
1417} loop_data;
1418
1419SEC("raw_tp")
1420__success
1421int iter_arr_with_actual_elem_count(const void *ctx)
1422{
1423 int i, n = loop_data.n, sum = 0;
1424
1425 if (n > ARRAY_SIZE(loop_data.data))
1426 return 0;
1427
1428 bpf_for(i, 0, n) {
1429 /* no rechecking of i against ARRAY_SIZE(loop_data.n) */
1430 sum += loop_data.data[i];
1431 }
1432
1433 return sum;
1434}
1435
1436char _license[] SEC("license") = "GPL";