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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
10static volatile int zero = 0;
11
12int my_pid;
13int arr[256];
14int small_arr[16] SEC(".data.small_arr");
15
16struct {
17 __uint(type, BPF_MAP_TYPE_HASH);
18 __uint(max_entries, 10);
19 __type(key, int);
20 __type(value, int);
21} amap SEC(".maps");
22
23#ifdef REAL_TEST
24#define MY_PID_GUARD() if (my_pid != (bpf_get_current_pid_tgid() >> 32)) return 0
25#else
26#define MY_PID_GUARD() ({ })
27#endif
28
29SEC("?raw_tp")
30__failure __msg("math between map_value pointer and register with unbounded min value is not allowed")
31int iter_err_unsafe_c_loop(const void *ctx)
32{
33 struct bpf_iter_num it;
34 int *v, i = zero; /* obscure initial value of i */
35
36 MY_PID_GUARD();
37
38 bpf_iter_num_new(&it, 0, 1000);
39 while ((v = bpf_iter_num_next(&it))) {
40 i++;
41 }
42 bpf_iter_num_destroy(&it);
43
44 small_arr[i] = 123; /* invalid */
45
46 return 0;
47}
48
49SEC("?raw_tp")
50__failure __msg("unbounded memory access")
51int iter_err_unsafe_asm_loop(const void *ctx)
52{
53 struct bpf_iter_num it;
54
55 MY_PID_GUARD();
56
57 asm volatile (
58 "r6 = %[zero];" /* iteration counter */
59 "r1 = %[it];" /* iterator state */
60 "r2 = 0;"
61 "r3 = 1000;"
62 "r4 = 1;"
63 "call %[bpf_iter_num_new];"
64 "loop:"
65 "r1 = %[it];"
66 "call %[bpf_iter_num_next];"
67 "if r0 == 0 goto out;"
68 "r6 += 1;"
69 "goto loop;"
70 "out:"
71 "r1 = %[it];"
72 "call %[bpf_iter_num_destroy];"
73 "r1 = %[small_arr];"
74 "r2 = r6;"
75 "r2 <<= 2;"
76 "r1 += r2;"
77 "*(u32 *)(r1 + 0) = r6;" /* invalid */
78 :
79 : [it]"r"(&it),
80 [small_arr]"r"(small_arr),
81 [zero]"r"(zero),
82 __imm(bpf_iter_num_new),
83 __imm(bpf_iter_num_next),
84 __imm(bpf_iter_num_destroy)
85 : __clobber_common, "r6"
86 );
87
88 return 0;
89}
90
91SEC("raw_tp")
92__success
93int iter_while_loop(const void *ctx)
94{
95 struct bpf_iter_num it;
96 int *v;
97
98 MY_PID_GUARD();
99
100 bpf_iter_num_new(&it, 0, 3);
101 while ((v = bpf_iter_num_next(&it))) {
102 bpf_printk("ITER_BASIC: E1 VAL: v=%d", *v);
103 }
104 bpf_iter_num_destroy(&it);
105
106 return 0;
107}
108
109SEC("raw_tp")
110__success
111int iter_while_loop_auto_cleanup(const void *ctx)
112{
113 __attribute__((cleanup(bpf_iter_num_destroy))) struct bpf_iter_num it;
114 int *v;
115
116 MY_PID_GUARD();
117
118 bpf_iter_num_new(&it, 0, 3);
119 while ((v = bpf_iter_num_next(&it))) {
120 bpf_printk("ITER_BASIC: E1 VAL: v=%d", *v);
121 }
122 /* (!) no explicit bpf_iter_num_destroy() */
123
124 return 0;
125}
126
127SEC("raw_tp")
128__success
129int iter_for_loop(const void *ctx)
130{
131 struct bpf_iter_num it;
132 int *v;
133
134 MY_PID_GUARD();
135
136 bpf_iter_num_new(&it, 5, 10);
137 for (v = bpf_iter_num_next(&it); v; v = bpf_iter_num_next(&it)) {
138 bpf_printk("ITER_BASIC: E2 VAL: v=%d", *v);
139 }
140 bpf_iter_num_destroy(&it);
141
142 return 0;
143}
144
145SEC("raw_tp")
146__success
147int iter_bpf_for_each_macro(const void *ctx)
148{
149 int *v;
150
151 MY_PID_GUARD();
152
153 bpf_for_each(num, v, 5, 10) {
154 bpf_printk("ITER_BASIC: E2 VAL: v=%d", *v);
155 }
156
157 return 0;
158}
159
160SEC("raw_tp")
161__success
162int iter_bpf_for_macro(const void *ctx)
163{
164 int i;
165
166 MY_PID_GUARD();
167
168 bpf_for(i, 5, 10) {
169 bpf_printk("ITER_BASIC: E2 VAL: v=%d", i);
170 }
171
172 return 0;
173}
174
175SEC("raw_tp")
176__success
177int iter_pragma_unroll_loop(const void *ctx)
178{
179 struct bpf_iter_num it;
180 int *v, i;
181
182 MY_PID_GUARD();
183
184 bpf_iter_num_new(&it, 0, 2);
185 __pragma_loop_no_unroll
186 for (i = 0; i < 3; i++) {
187 v = bpf_iter_num_next(&it);
188 bpf_printk("ITER_BASIC: E3 VAL: i=%d v=%d", i, v ? *v : -1);
189 }
190 bpf_iter_num_destroy(&it);
191
192 return 0;
193}
194
195SEC("raw_tp")
196__success
197int iter_manual_unroll_loop(const void *ctx)
198{
199 struct bpf_iter_num it;
200 int *v;
201
202 MY_PID_GUARD();
203
204 bpf_iter_num_new(&it, 100, 200);
205 v = bpf_iter_num_next(&it);
206 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
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\n", v ? *v : -1);
213 bpf_iter_num_destroy(&it);
214
215 return 0;
216}
217
218SEC("raw_tp")
219__success
220int iter_multiple_sequential_loops(const void *ctx)
221{
222 struct bpf_iter_num it;
223 int *v, i;
224
225 MY_PID_GUARD();
226
227 bpf_iter_num_new(&it, 0, 3);
228 while ((v = bpf_iter_num_next(&it))) {
229 bpf_printk("ITER_BASIC: E1 VAL: v=%d", *v);
230 }
231 bpf_iter_num_destroy(&it);
232
233 bpf_iter_num_new(&it, 5, 10);
234 for (v = bpf_iter_num_next(&it); v; v = bpf_iter_num_next(&it)) {
235 bpf_printk("ITER_BASIC: E2 VAL: v=%d", *v);
236 }
237 bpf_iter_num_destroy(&it);
238
239 bpf_iter_num_new(&it, 0, 2);
240 __pragma_loop_no_unroll
241 for (i = 0; i < 3; i++) {
242 v = bpf_iter_num_next(&it);
243 bpf_printk("ITER_BASIC: E3 VAL: i=%d v=%d", i, v ? *v : -1);
244 }
245 bpf_iter_num_destroy(&it);
246
247 bpf_iter_num_new(&it, 100, 200);
248 v = bpf_iter_num_next(&it);
249 bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
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\n", v ? *v : -1);
256 bpf_iter_num_destroy(&it);
257
258 return 0;
259}
260
261SEC("raw_tp")
262__success
263int iter_limit_cond_break_loop(const void *ctx)
264{
265 struct bpf_iter_num it;
266 int *v, i = 0, sum = 0;
267
268 MY_PID_GUARD();
269
270 bpf_iter_num_new(&it, 0, 10);
271 while ((v = bpf_iter_num_next(&it))) {
272 bpf_printk("ITER_SIMPLE: i=%d v=%d", i, *v);
273 sum += *v;
274
275 i++;
276 if (i > 3)
277 break;
278 }
279 bpf_iter_num_destroy(&it);
280
281 bpf_printk("ITER_SIMPLE: sum=%d\n", sum);
282
283 return 0;
284}
285
286SEC("raw_tp")
287__success
288int iter_obfuscate_counter(const void *ctx)
289{
290 struct bpf_iter_num it;
291 int *v, sum = 0;
292 /* Make i's initial value unknowable for verifier to prevent it from
293 * pruning if/else branch inside the loop body and marking i as precise.
294 */
295 int i = zero;
296
297 MY_PID_GUARD();
298
299 bpf_iter_num_new(&it, 0, 10);
300 while ((v = bpf_iter_num_next(&it))) {
301 int x;
302
303 i += 1;
304
305 /* If we initialized i as `int i = 0;` above, verifier would
306 * track that i becomes 1 on first iteration after increment
307 * above, and here verifier would eagerly prune else branch
308 * and mark i as precise, ruining open-coded iterator logic
309 * completely, as each next iteration would have a different
310 * *precise* value of i, and thus there would be no
311 * convergence of state. This would result in reaching maximum
312 * instruction limit, no matter what the limit is.
313 */
314 if (i == 1)
315 x = 123;
316 else
317 x = i * 3 + 1;
318
319 bpf_printk("ITER_OBFUSCATE_COUNTER: i=%d v=%d x=%d", i, *v, x);
320
321 sum += x;
322 }
323 bpf_iter_num_destroy(&it);
324
325 bpf_printk("ITER_OBFUSCATE_COUNTER: sum=%d\n", sum);
326
327 return 0;
328}
329
330SEC("raw_tp")
331__success
332int iter_search_loop(const void *ctx)
333{
334 struct bpf_iter_num it;
335 int *v, *elem = NULL;
336 bool found = false;
337
338 MY_PID_GUARD();
339
340 bpf_iter_num_new(&it, 0, 10);
341
342 while ((v = bpf_iter_num_next(&it))) {
343 bpf_printk("ITER_SEARCH_LOOP: v=%d", *v);
344
345 if (*v == 2) {
346 found = true;
347 elem = v;
348 barrier_var(elem);
349 }
350 }
351
352 /* should fail to verify if bpf_iter_num_destroy() is here */
353
354 if (found)
355 /* here found element will be wrong, we should have copied
356 * value to a variable, but here we want to make sure we can
357 * access memory after the loop anyways
358 */
359 bpf_printk("ITER_SEARCH_LOOP: FOUND IT = %d!\n", *elem);
360 else
361 bpf_printk("ITER_SEARCH_LOOP: NOT FOUND IT!\n");
362
363 bpf_iter_num_destroy(&it);
364
365 return 0;
366}
367
368SEC("raw_tp")
369__success
370int iter_array_fill(const void *ctx)
371{
372 int sum, i;
373
374 MY_PID_GUARD();
375
376 bpf_for(i, 0, ARRAY_SIZE(arr)) {
377 arr[i] = i * 2;
378 }
379
380 sum = 0;
381 bpf_for(i, 0, ARRAY_SIZE(arr)) {
382 sum += arr[i];
383 }
384
385 bpf_printk("ITER_ARRAY_FILL: sum=%d (should be %d)\n", sum, 255 * 256);
386
387 return 0;
388}
389
390static int arr2d[4][5];
391static int arr2d_row_sums[4];
392static int arr2d_col_sums[5];
393
394SEC("raw_tp")
395__success
396int iter_nested_iters(const void *ctx)
397{
398 int sum, row, col;
399
400 MY_PID_GUARD();
401
402 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
403 bpf_for( col, 0, ARRAY_SIZE(arr2d[0])) {
404 arr2d[row][col] = row * col;
405 }
406 }
407
408 /* zero-initialize sums */
409 sum = 0;
410 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
411 arr2d_row_sums[row] = 0;
412 }
413 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
414 arr2d_col_sums[col] = 0;
415 }
416
417 /* calculate sums */
418 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
419 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
420 sum += arr2d[row][col];
421 arr2d_row_sums[row] += arr2d[row][col];
422 arr2d_col_sums[col] += arr2d[row][col];
423 }
424 }
425
426 bpf_printk("ITER_NESTED_ITERS: total sum=%d", sum);
427 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
428 bpf_printk("ITER_NESTED_ITERS: row #%d sum=%d", row, arr2d_row_sums[row]);
429 }
430 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
431 bpf_printk("ITER_NESTED_ITERS: col #%d sum=%d%s",
432 col, arr2d_col_sums[col],
433 col == ARRAY_SIZE(arr2d[0]) - 1 ? "\n" : "");
434 }
435
436 return 0;
437}
438
439SEC("raw_tp")
440__success
441int iter_nested_deeply_iters(const void *ctx)
442{
443 int sum = 0;
444
445 MY_PID_GUARD();
446
447 bpf_repeat(10) {
448 bpf_repeat(10) {
449 bpf_repeat(10) {
450 bpf_repeat(10) {
451 bpf_repeat(10) {
452 sum += 1;
453 }
454 }
455 }
456 }
457 /* validate that we can break from inside bpf_repeat() */
458 break;
459 }
460
461 return sum;
462}
463
464static __noinline void fill_inner_dimension(int row)
465{
466 int col;
467
468 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
469 arr2d[row][col] = row * col;
470 }
471}
472
473static __noinline int sum_inner_dimension(int row)
474{
475 int sum = 0, col;
476
477 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
478 sum += arr2d[row][col];
479 arr2d_row_sums[row] += arr2d[row][col];
480 arr2d_col_sums[col] += arr2d[row][col];
481 }
482
483 return sum;
484}
485
486SEC("raw_tp")
487__success
488int iter_subprog_iters(const void *ctx)
489{
490 int sum, row, col;
491
492 MY_PID_GUARD();
493
494 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
495 fill_inner_dimension(row);
496 }
497
498 /* zero-initialize sums */
499 sum = 0;
500 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
501 arr2d_row_sums[row] = 0;
502 }
503 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
504 arr2d_col_sums[col] = 0;
505 }
506
507 /* calculate sums */
508 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
509 sum += sum_inner_dimension(row);
510 }
511
512 bpf_printk("ITER_SUBPROG_ITERS: total sum=%d", sum);
513 bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
514 bpf_printk("ITER_SUBPROG_ITERS: row #%d sum=%d",
515 row, arr2d_row_sums[row]);
516 }
517 bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
518 bpf_printk("ITER_SUBPROG_ITERS: col #%d sum=%d%s",
519 col, arr2d_col_sums[col],
520 col == ARRAY_SIZE(arr2d[0]) - 1 ? "\n" : "");
521 }
522
523 return 0;
524}
525
526struct {
527 __uint(type, BPF_MAP_TYPE_ARRAY);
528 __type(key, int);
529 __type(value, int);
530 __uint(max_entries, 1000);
531} arr_map SEC(".maps");
532
533SEC("?raw_tp")
534__failure __msg("invalid mem access 'scalar'")
535int iter_err_too_permissive1(const void *ctx)
536{
537 int *map_val = NULL;
538 int key = 0;
539
540 MY_PID_GUARD();
541
542 map_val = bpf_map_lookup_elem(&arr_map, &key);
543 if (!map_val)
544 return 0;
545
546 bpf_repeat(1000000) {
547 map_val = NULL;
548 }
549
550 *map_val = 123;
551
552 return 0;
553}
554
555SEC("?raw_tp")
556__failure __msg("invalid mem access 'map_value_or_null'")
557int iter_err_too_permissive2(const void *ctx)
558{
559 int *map_val = NULL;
560 int key = 0;
561
562 MY_PID_GUARD();
563
564 map_val = bpf_map_lookup_elem(&arr_map, &key);
565 if (!map_val)
566 return 0;
567
568 bpf_repeat(1000000) {
569 map_val = bpf_map_lookup_elem(&arr_map, &key);
570 }
571
572 *map_val = 123;
573
574 return 0;
575}
576
577SEC("?raw_tp")
578__failure __msg("invalid mem access 'map_value_or_null'")
579int iter_err_too_permissive3(const void *ctx)
580{
581 int *map_val = NULL;
582 int key = 0;
583 bool found = false;
584
585 MY_PID_GUARD();
586
587 bpf_repeat(1000000) {
588 map_val = bpf_map_lookup_elem(&arr_map, &key);
589 found = true;
590 }
591
592 if (found)
593 *map_val = 123;
594
595 return 0;
596}
597
598SEC("raw_tp")
599__success
600int iter_tricky_but_fine(const void *ctx)
601{
602 int *map_val = NULL;
603 int key = 0;
604 bool found = false;
605
606 MY_PID_GUARD();
607
608 bpf_repeat(1000000) {
609 map_val = bpf_map_lookup_elem(&arr_map, &key);
610 if (map_val) {
611 found = true;
612 break;
613 }
614 }
615
616 if (found)
617 *map_val = 123;
618
619 return 0;
620}
621
622#define __bpf_memzero(p, sz) bpf_probe_read_kernel((p), (sz), 0)
623
624SEC("raw_tp")
625__success
626int iter_stack_array_loop(const void *ctx)
627{
628 long arr1[16], arr2[16], sum = 0;
629 int i;
630
631 MY_PID_GUARD();
632
633 /* zero-init arr1 and arr2 in such a way that verifier doesn't know
634 * it's all zeros; if we don't do that, we'll make BPF verifier track
635 * all combination of zero/non-zero stack slots for arr1/arr2, which
636 * will lead to O(2^(ARRAY_SIZE(arr1)+ARRAY_SIZE(arr2))) different
637 * states
638 */
639 __bpf_memzero(arr1, sizeof(arr1));
640 __bpf_memzero(arr2, sizeof(arr1));
641
642 /* validate that we can break and continue when using bpf_for() */
643 bpf_for(i, 0, ARRAY_SIZE(arr1)) {
644 if (i & 1) {
645 arr1[i] = i;
646 continue;
647 } else {
648 arr2[i] = i;
649 break;
650 }
651 }
652
653 bpf_for(i, 0, ARRAY_SIZE(arr1)) {
654 sum += arr1[i] + arr2[i];
655 }
656
657 return sum;
658}
659
660static __noinline void fill(struct bpf_iter_num *it, int *arr, __u32 n, int mul)
661{
662 int *t, i;
663
664 while ((t = bpf_iter_num_next(it))) {
665 i = *t;
666 if (i >= n)
667 break;
668 arr[i] = i * mul;
669 }
670}
671
672static __noinline int sum(struct bpf_iter_num *it, int *arr, __u32 n)
673{
674 int *t, i, sum = 0;
675
676 while ((t = bpf_iter_num_next(it))) {
677 i = *t;
678 if ((__u32)i >= n)
679 break;
680 sum += arr[i];
681 }
682
683 return sum;
684}
685
686SEC("raw_tp")
687__success
688int iter_pass_iter_ptr_to_subprog(const void *ctx)
689{
690 int arr1[16], arr2[32];
691 struct bpf_iter_num it;
692 int n, sum1, sum2;
693
694 MY_PID_GUARD();
695
696 /* fill arr1 */
697 n = ARRAY_SIZE(arr1);
698 bpf_iter_num_new(&it, 0, n);
699 fill(&it, arr1, n, 2);
700 bpf_iter_num_destroy(&it);
701
702 /* fill arr2 */
703 n = ARRAY_SIZE(arr2);
704 bpf_iter_num_new(&it, 0, n);
705 fill(&it, arr2, n, 10);
706 bpf_iter_num_destroy(&it);
707
708 /* sum arr1 */
709 n = ARRAY_SIZE(arr1);
710 bpf_iter_num_new(&it, 0, n);
711 sum1 = sum(&it, arr1, n);
712 bpf_iter_num_destroy(&it);
713
714 /* sum arr2 */
715 n = ARRAY_SIZE(arr2);
716 bpf_iter_num_new(&it, 0, n);
717 sum2 = sum(&it, arr2, n);
718 bpf_iter_num_destroy(&it);
719
720 bpf_printk("sum1=%d, sum2=%d", sum1, sum2);
721
722 return 0;
723}
724
725SEC("?raw_tp")
726__failure
727__msg("R1 type=scalar expected=fp")
728__naked int delayed_read_mark(void)
729{
730 /* This is equivalent to C program below.
731 * The call to bpf_iter_num_next() is reachable with r7 values &fp[-16] and 0xdead.
732 * State with r7=&fp[-16] is visited first and follows r6 != 42 ... continue branch.
733 * At this point iterator next() call is reached with r7 that has no read mark.
734 * Loop body with r7=0xdead would only be visited if verifier would decide to continue
735 * with second loop iteration. Absence of read mark on r7 might affect state
736 * equivalent logic used for iterator convergence tracking.
737 *
738 * r7 = &fp[-16]
739 * fp[-16] = 0
740 * r6 = bpf_get_prandom_u32()
741 * bpf_iter_num_new(&fp[-8], 0, 10)
742 * while (bpf_iter_num_next(&fp[-8])) {
743 * r6++
744 * if (r6 != 42) {
745 * r7 = 0xdead
746 * continue;
747 * }
748 * bpf_probe_read_user(r7, 8, 0xdeadbeef); // this is not safe
749 * }
750 * bpf_iter_num_destroy(&fp[-8])
751 * return 0
752 */
753 asm volatile (
754 "r7 = r10;"
755 "r7 += -16;"
756 "r0 = 0;"
757 "*(u64 *)(r7 + 0) = r0;"
758 "call %[bpf_get_prandom_u32];"
759 "r6 = r0;"
760 "r1 = r10;"
761 "r1 += -8;"
762 "r2 = 0;"
763 "r3 = 10;"
764 "call %[bpf_iter_num_new];"
765 "1:"
766 "r1 = r10;"
767 "r1 += -8;"
768 "call %[bpf_iter_num_next];"
769 "if r0 == 0 goto 2f;"
770 "r6 += 1;"
771 "if r6 != 42 goto 3f;"
772 "r7 = 0xdead;"
773 "goto 1b;"
774 "3:"
775 "r1 = r7;"
776 "r2 = 8;"
777 "r3 = 0xdeadbeef;"
778 "call %[bpf_probe_read_user];"
779 "goto 1b;"
780 "2:"
781 "r1 = r10;"
782 "r1 += -8;"
783 "call %[bpf_iter_num_destroy];"
784 "r0 = 0;"
785 "exit;"
786 :
787 : __imm(bpf_get_prandom_u32),
788 __imm(bpf_iter_num_new),
789 __imm(bpf_iter_num_next),
790 __imm(bpf_iter_num_destroy),
791 __imm(bpf_probe_read_user)
792 : __clobber_all
793 );
794}
795
796SEC("?raw_tp")
797__failure
798__msg("math between fp pointer and register with unbounded")
799__naked int delayed_precision_mark(void)
800{
801 /* This is equivalent to C program below.
802 * The test is similar to delayed_iter_mark but verifies that incomplete
803 * precision don't fool verifier.
804 * The call to bpf_iter_num_next() is reachable with r7 values -16 and -32.
805 * State with r7=-16 is visited first and follows r6 != 42 ... continue branch.
806 * At this point iterator next() call is reached with r7 that has no read
807 * and precision marks.
808 * Loop body with r7=-32 would only be visited if verifier would decide to continue
809 * with second loop iteration. Absence of precision mark on r7 might affect state
810 * equivalent logic used for iterator convergence tracking.
811 *
812 * r8 = 0
813 * fp[-16] = 0
814 * r7 = -16
815 * r6 = bpf_get_prandom_u32()
816 * bpf_iter_num_new(&fp[-8], 0, 10)
817 * while (bpf_iter_num_next(&fp[-8])) {
818 * if (r6 != 42) {
819 * r7 = -32
820 * r6 = bpf_get_prandom_u32()
821 * continue;
822 * }
823 * r0 = r10
824 * r0 += r7
825 * r8 = *(u64 *)(r0 + 0) // this is not safe
826 * r6 = bpf_get_prandom_u32()
827 * }
828 * bpf_iter_num_destroy(&fp[-8])
829 * return r8
830 */
831 asm volatile (
832 "r8 = 0;"
833 "*(u64 *)(r10 - 16) = r8;"
834 "r7 = -16;"
835 "call %[bpf_get_prandom_u32];"
836 "r6 = r0;"
837 "r1 = r10;"
838 "r1 += -8;"
839 "r2 = 0;"
840 "r3 = 10;"
841 "call %[bpf_iter_num_new];"
842 "1:"
843 "r1 = r10;"
844 "r1 += -8;\n"
845 "call %[bpf_iter_num_next];"
846 "if r0 == 0 goto 2f;"
847 "if r6 != 42 goto 3f;"
848 "r7 = -33;"
849 "call %[bpf_get_prandom_u32];"
850 "r6 = r0;"
851 "goto 1b;\n"
852 "3:"
853 "r0 = r10;"
854 "r0 += r7;"
855 "r8 = *(u64 *)(r0 + 0);"
856 "call %[bpf_get_prandom_u32];"
857 "r6 = r0;"
858 "goto 1b;\n"
859 "2:"
860 "r1 = r10;"
861 "r1 += -8;"
862 "call %[bpf_iter_num_destroy];"
863 "r0 = r8;"
864 "exit;"
865 :
866 : __imm(bpf_get_prandom_u32),
867 __imm(bpf_iter_num_new),
868 __imm(bpf_iter_num_next),
869 __imm(bpf_iter_num_destroy),
870 __imm(bpf_probe_read_user)
871 : __clobber_all
872 );
873}
874
875SEC("?raw_tp")
876__failure
877__msg("math between fp pointer and register with unbounded")
878__flag(BPF_F_TEST_STATE_FREQ)
879__naked int loop_state_deps1(void)
880{
881 /* This is equivalent to C program below.
882 *
883 * The case turns out to be tricky in a sense that:
884 * - states with c=-25 are explored only on a second iteration
885 * of the outer loop;
886 * - states with read+precise mark on c are explored only on
887 * second iteration of the inner loop and in a state which
888 * is pushed to states stack first.
889 *
890 * Depending on the details of iterator convergence logic
891 * verifier might stop states traversal too early and miss
892 * unsafe c=-25 memory access.
893 *
894 * j = iter_new(); // fp[-16]
895 * a = 0; // r6
896 * b = 0; // r7
897 * c = -24; // r8
898 * while (iter_next(j)) {
899 * i = iter_new(); // fp[-8]
900 * a = 0; // r6
901 * b = 0; // r7
902 * while (iter_next(i)) {
903 * if (a == 1) {
904 * a = 0;
905 * b = 1;
906 * } else if (a == 0) {
907 * a = 1;
908 * if (random() == 42)
909 * continue;
910 * if (b == 1) {
911 * *(r10 + c) = 7; // this is not safe
912 * iter_destroy(i);
913 * iter_destroy(j);
914 * return;
915 * }
916 * }
917 * }
918 * iter_destroy(i);
919 * a = 0;
920 * b = 0;
921 * c = -25;
922 * }
923 * iter_destroy(j);
924 * return;
925 */
926 asm volatile (
927 "r1 = r10;"
928 "r1 += -16;"
929 "r2 = 0;"
930 "r3 = 10;"
931 "call %[bpf_iter_num_new];"
932 "r6 = 0;"
933 "r7 = 0;"
934 "r8 = -24;"
935 "j_loop_%=:"
936 "r1 = r10;"
937 "r1 += -16;"
938 "call %[bpf_iter_num_next];"
939 "if r0 == 0 goto j_loop_end_%=;"
940 "r1 = r10;"
941 "r1 += -8;"
942 "r2 = 0;"
943 "r3 = 10;"
944 "call %[bpf_iter_num_new];"
945 "r6 = 0;"
946 "r7 = 0;"
947 "i_loop_%=:"
948 "r1 = r10;"
949 "r1 += -8;"
950 "call %[bpf_iter_num_next];"
951 "if r0 == 0 goto i_loop_end_%=;"
952 "check_one_r6_%=:"
953 "if r6 != 1 goto check_zero_r6_%=;"
954 "r6 = 0;"
955 "r7 = 1;"
956 "goto i_loop_%=;"
957 "check_zero_r6_%=:"
958 "if r6 != 0 goto i_loop_%=;"
959 "r6 = 1;"
960 "call %[bpf_get_prandom_u32];"
961 "if r0 != 42 goto check_one_r7_%=;"
962 "goto i_loop_%=;"
963 "check_one_r7_%=:"
964 "if r7 != 1 goto i_loop_%=;"
965 "r0 = r10;"
966 "r0 += r8;"
967 "r1 = 7;"
968 "*(u64 *)(r0 + 0) = r1;"
969 "r1 = r10;"
970 "r1 += -8;"
971 "call %[bpf_iter_num_destroy];"
972 "r1 = r10;"
973 "r1 += -16;"
974 "call %[bpf_iter_num_destroy];"
975 "r0 = 0;"
976 "exit;"
977 "i_loop_end_%=:"
978 "r1 = r10;"
979 "r1 += -8;"
980 "call %[bpf_iter_num_destroy];"
981 "r6 = 0;"
982 "r7 = 0;"
983 "r8 = -25;"
984 "goto j_loop_%=;"
985 "j_loop_end_%=:"
986 "r1 = r10;"
987 "r1 += -16;"
988 "call %[bpf_iter_num_destroy];"
989 "r0 = 0;"
990 "exit;"
991 :
992 : __imm(bpf_get_prandom_u32),
993 __imm(bpf_iter_num_new),
994 __imm(bpf_iter_num_next),
995 __imm(bpf_iter_num_destroy)
996 : __clobber_all
997 );
998}
999
1000SEC("?raw_tp")
1001__failure
1002__msg("math between fp pointer and register with unbounded")
1003__flag(BPF_F_TEST_STATE_FREQ)
1004__naked int loop_state_deps2(void)
1005{
1006 /* This is equivalent to C program below.
1007 *
1008 * The case turns out to be tricky in a sense that:
1009 * - states with read+precise mark on c are explored only on a second
1010 * iteration of the first inner loop and in a state which is pushed to
1011 * states stack first.
1012 * - states with c=-25 are explored only on a second iteration of the
1013 * second inner loop and in a state which is pushed to states stack
1014 * first.
1015 *
1016 * Depending on the details of iterator convergence logic
1017 * verifier might stop states traversal too early and miss
1018 * unsafe c=-25 memory access.
1019 *
1020 * j = iter_new(); // fp[-16]
1021 * a = 0; // r6
1022 * b = 0; // r7
1023 * c = -24; // r8
1024 * while (iter_next(j)) {
1025 * i = iter_new(); // fp[-8]
1026 * a = 0; // r6
1027 * b = 0; // r7
1028 * while (iter_next(i)) {
1029 * if (a == 1) {
1030 * a = 0;
1031 * b = 1;
1032 * } else if (a == 0) {
1033 * a = 1;
1034 * if (random() == 42)
1035 * continue;
1036 * if (b == 1) {
1037 * *(r10 + c) = 7; // this is not safe
1038 * iter_destroy(i);
1039 * iter_destroy(j);
1040 * return;
1041 * }
1042 * }
1043 * }
1044 * iter_destroy(i);
1045 * i = iter_new(); // fp[-8]
1046 * a = 0; // r6
1047 * b = 0; // r7
1048 * while (iter_next(i)) {
1049 * if (a == 1) {
1050 * a = 0;
1051 * b = 1;
1052 * } else if (a == 0) {
1053 * a = 1;
1054 * if (random() == 42)
1055 * continue;
1056 * if (b == 1) {
1057 * a = 0;
1058 * c = -25;
1059 * }
1060 * }
1061 * }
1062 * iter_destroy(i);
1063 * }
1064 * iter_destroy(j);
1065 * return;
1066 */
1067 asm volatile (
1068 "r1 = r10;"
1069 "r1 += -16;"
1070 "r2 = 0;"
1071 "r3 = 10;"
1072 "call %[bpf_iter_num_new];"
1073 "r6 = 0;"
1074 "r7 = 0;"
1075 "r8 = -24;"
1076 "j_loop_%=:"
1077 "r1 = r10;"
1078 "r1 += -16;"
1079 "call %[bpf_iter_num_next];"
1080 "if r0 == 0 goto j_loop_end_%=;"
1081
1082 /* first inner loop */
1083 "r1 = r10;"
1084 "r1 += -8;"
1085 "r2 = 0;"
1086 "r3 = 10;"
1087 "call %[bpf_iter_num_new];"
1088 "r6 = 0;"
1089 "r7 = 0;"
1090 "i_loop_%=:"
1091 "r1 = r10;"
1092 "r1 += -8;"
1093 "call %[bpf_iter_num_next];"
1094 "if r0 == 0 goto i_loop_end_%=;"
1095 "check_one_r6_%=:"
1096 "if r6 != 1 goto check_zero_r6_%=;"
1097 "r6 = 0;"
1098 "r7 = 1;"
1099 "goto i_loop_%=;"
1100 "check_zero_r6_%=:"
1101 "if r6 != 0 goto i_loop_%=;"
1102 "r6 = 1;"
1103 "call %[bpf_get_prandom_u32];"
1104 "if r0 != 42 goto check_one_r7_%=;"
1105 "goto i_loop_%=;"
1106 "check_one_r7_%=:"
1107 "if r7 != 1 goto i_loop_%=;"
1108 "r0 = r10;"
1109 "r0 += r8;"
1110 "r1 = 7;"
1111 "*(u64 *)(r0 + 0) = r1;"
1112 "r1 = r10;"
1113 "r1 += -8;"
1114 "call %[bpf_iter_num_destroy];"
1115 "r1 = r10;"
1116 "r1 += -16;"
1117 "call %[bpf_iter_num_destroy];"
1118 "r0 = 0;"
1119 "exit;"
1120 "i_loop_end_%=:"
1121 "r1 = r10;"
1122 "r1 += -8;"
1123 "call %[bpf_iter_num_destroy];"
1124
1125 /* second inner loop */
1126 "r1 = r10;"
1127 "r1 += -8;"
1128 "r2 = 0;"
1129 "r3 = 10;"
1130 "call %[bpf_iter_num_new];"
1131 "r6 = 0;"
1132 "r7 = 0;"
1133 "i2_loop_%=:"
1134 "r1 = r10;"
1135 "r1 += -8;"
1136 "call %[bpf_iter_num_next];"
1137 "if r0 == 0 goto i2_loop_end_%=;"
1138 "check2_one_r6_%=:"
1139 "if r6 != 1 goto check2_zero_r6_%=;"
1140 "r6 = 0;"
1141 "r7 = 1;"
1142 "goto i2_loop_%=;"
1143 "check2_zero_r6_%=:"
1144 "if r6 != 0 goto i2_loop_%=;"
1145 "r6 = 1;"
1146 "call %[bpf_get_prandom_u32];"
1147 "if r0 != 42 goto check2_one_r7_%=;"
1148 "goto i2_loop_%=;"
1149 "check2_one_r7_%=:"
1150 "if r7 != 1 goto i2_loop_%=;"
1151 "r6 = 0;"
1152 "r8 = -25;"
1153 "goto i2_loop_%=;"
1154 "i2_loop_end_%=:"
1155 "r1 = r10;"
1156 "r1 += -8;"
1157 "call %[bpf_iter_num_destroy];"
1158
1159 "r6 = 0;"
1160 "r7 = 0;"
1161 "goto j_loop_%=;"
1162 "j_loop_end_%=:"
1163 "r1 = r10;"
1164 "r1 += -16;"
1165 "call %[bpf_iter_num_destroy];"
1166 "r0 = 0;"
1167 "exit;"
1168 :
1169 : __imm(bpf_get_prandom_u32),
1170 __imm(bpf_iter_num_new),
1171 __imm(bpf_iter_num_next),
1172 __imm(bpf_iter_num_destroy)
1173 : __clobber_all
1174 );
1175}
1176
1177SEC("?raw_tp")
1178__success
1179__naked int triple_continue(void)
1180{
1181 /* This is equivalent to C program below.
1182 * High branching factor of the loop body turned out to be
1183 * problematic for one of the iterator convergence tracking
1184 * algorithms explored.
1185 *
1186 * r6 = bpf_get_prandom_u32()
1187 * bpf_iter_num_new(&fp[-8], 0, 10)
1188 * while (bpf_iter_num_next(&fp[-8])) {
1189 * if (bpf_get_prandom_u32() != 42)
1190 * continue;
1191 * if (bpf_get_prandom_u32() != 42)
1192 * continue;
1193 * if (bpf_get_prandom_u32() != 42)
1194 * continue;
1195 * r0 += 0;
1196 * }
1197 * bpf_iter_num_destroy(&fp[-8])
1198 * return 0
1199 */
1200 asm volatile (
1201 "r1 = r10;"
1202 "r1 += -8;"
1203 "r2 = 0;"
1204 "r3 = 10;"
1205 "call %[bpf_iter_num_new];"
1206 "loop_%=:"
1207 "r1 = r10;"
1208 "r1 += -8;"
1209 "call %[bpf_iter_num_next];"
1210 "if r0 == 0 goto loop_end_%=;"
1211 "call %[bpf_get_prandom_u32];"
1212 "if r0 != 42 goto loop_%=;"
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 "r0 += 0;"
1218 "goto loop_%=;"
1219 "loop_end_%=:"
1220 "r1 = r10;"
1221 "r1 += -8;"
1222 "call %[bpf_iter_num_destroy];"
1223 "r0 = 0;"
1224 "exit;"
1225 :
1226 : __imm(bpf_get_prandom_u32),
1227 __imm(bpf_iter_num_new),
1228 __imm(bpf_iter_num_next),
1229 __imm(bpf_iter_num_destroy)
1230 : __clobber_all
1231 );
1232}
1233
1234SEC("?raw_tp")
1235__success
1236__naked int widen_spill(void)
1237{
1238 /* This is equivalent to C program below.
1239 * The counter is stored in fp[-16], if this counter is not widened
1240 * verifier states representing loop iterations would never converge.
1241 *
1242 * fp[-16] = 0
1243 * bpf_iter_num_new(&fp[-8], 0, 10)
1244 * while (bpf_iter_num_next(&fp[-8])) {
1245 * r0 = fp[-16];
1246 * r0 += 1;
1247 * fp[-16] = r0;
1248 * }
1249 * bpf_iter_num_destroy(&fp[-8])
1250 * return 0
1251 */
1252 asm volatile (
1253 "r0 = 0;"
1254 "*(u64 *)(r10 - 16) = r0;"
1255 "r1 = r10;"
1256 "r1 += -8;"
1257 "r2 = 0;"
1258 "r3 = 10;"
1259 "call %[bpf_iter_num_new];"
1260 "loop_%=:"
1261 "r1 = r10;"
1262 "r1 += -8;"
1263 "call %[bpf_iter_num_next];"
1264 "if r0 == 0 goto loop_end_%=;"
1265 "r0 = *(u64 *)(r10 - 16);"
1266 "r0 += 1;"
1267 "*(u64 *)(r10 - 16) = r0;"
1268 "goto loop_%=;"
1269 "loop_end_%=:"
1270 "r1 = r10;"
1271 "r1 += -8;"
1272 "call %[bpf_iter_num_destroy];"
1273 "r0 = 0;"
1274 "exit;"
1275 :
1276 : __imm(bpf_iter_num_new),
1277 __imm(bpf_iter_num_next),
1278 __imm(bpf_iter_num_destroy)
1279 : __clobber_all
1280 );
1281}
1282
1283SEC("raw_tp")
1284__success
1285__naked int checkpoint_states_deletion(void)
1286{
1287 /* This is equivalent to C program below.
1288 *
1289 * int *a, *b, *c, *d, *e, *f;
1290 * int i, sum = 0;
1291 * bpf_for(i, 0, 10) {
1292 * a = bpf_map_lookup_elem(&amap, &i);
1293 * b = bpf_map_lookup_elem(&amap, &i);
1294 * c = bpf_map_lookup_elem(&amap, &i);
1295 * d = bpf_map_lookup_elem(&amap, &i);
1296 * e = bpf_map_lookup_elem(&amap, &i);
1297 * f = bpf_map_lookup_elem(&amap, &i);
1298 * if (a) sum += 1;
1299 * if (b) sum += 1;
1300 * if (c) sum += 1;
1301 * if (d) sum += 1;
1302 * if (e) sum += 1;
1303 * if (f) sum += 1;
1304 * }
1305 * return 0;
1306 *
1307 * The body of the loop spawns multiple simulation paths
1308 * with different combination of NULL/non-NULL information for a/b/c/d/e/f.
1309 * Each combination is unique from states_equal() point of view.
1310 * Explored states checkpoint is created after each iterator next call.
1311 * Iterator convergence logic expects that eventually current state
1312 * would get equal to one of the explored states and thus loop
1313 * exploration would be finished (at-least for a specific path).
1314 * Verifier evicts explored states with high miss to hit ratio
1315 * to to avoid comparing current state with too many explored
1316 * states per instruction.
1317 * This test is designed to "stress test" eviction policy defined using formula:
1318 *
1319 * sl->miss_cnt > sl->hit_cnt * N + N // if true sl->state is evicted
1320 *
1321 * Currently N is set to 64, which allows for 6 variables in this test.
1322 */
1323 asm volatile (
1324 "r6 = 0;" /* a */
1325 "r7 = 0;" /* b */
1326 "r8 = 0;" /* c */
1327 "*(u64 *)(r10 - 24) = r6;" /* d */
1328 "*(u64 *)(r10 - 32) = r6;" /* e */
1329 "*(u64 *)(r10 - 40) = r6;" /* f */
1330 "r9 = 0;" /* sum */
1331 "r1 = r10;"
1332 "r1 += -8;"
1333 "r2 = 0;"
1334 "r3 = 10;"
1335 "call %[bpf_iter_num_new];"
1336 "loop_%=:"
1337 "r1 = r10;"
1338 "r1 += -8;"
1339 "call %[bpf_iter_num_next];"
1340 "if r0 == 0 goto loop_end_%=;"
1341
1342 "*(u64 *)(r10 - 16) = r0;"
1343
1344 "r1 = %[amap] ll;"
1345 "r2 = r10;"
1346 "r2 += -16;"
1347 "call %[bpf_map_lookup_elem];"
1348 "r6 = r0;"
1349
1350 "r1 = %[amap] ll;"
1351 "r2 = r10;"
1352 "r2 += -16;"
1353 "call %[bpf_map_lookup_elem];"
1354 "r7 = r0;"
1355
1356 "r1 = %[amap] ll;"
1357 "r2 = r10;"
1358 "r2 += -16;"
1359 "call %[bpf_map_lookup_elem];"
1360 "r8 = r0;"
1361
1362 "r1 = %[amap] ll;"
1363 "r2 = r10;"
1364 "r2 += -16;"
1365 "call %[bpf_map_lookup_elem];"
1366 "*(u64 *)(r10 - 24) = r0;"
1367
1368 "r1 = %[amap] ll;"
1369 "r2 = r10;"
1370 "r2 += -16;"
1371 "call %[bpf_map_lookup_elem];"
1372 "*(u64 *)(r10 - 32) = r0;"
1373
1374 "r1 = %[amap] ll;"
1375 "r2 = r10;"
1376 "r2 += -16;"
1377 "call %[bpf_map_lookup_elem];"
1378 "*(u64 *)(r10 - 40) = r0;"
1379
1380 "if r6 == 0 goto +1;"
1381 "r9 += 1;"
1382 "if r7 == 0 goto +1;"
1383 "r9 += 1;"
1384 "if r8 == 0 goto +1;"
1385 "r9 += 1;"
1386 "r0 = *(u64 *)(r10 - 24);"
1387 "if r0 == 0 goto +1;"
1388 "r9 += 1;"
1389 "r0 = *(u64 *)(r10 - 32);"
1390 "if r0 == 0 goto +1;"
1391 "r9 += 1;"
1392 "r0 = *(u64 *)(r10 - 40);"
1393 "if r0 == 0 goto +1;"
1394 "r9 += 1;"
1395
1396 "goto loop_%=;"
1397 "loop_end_%=:"
1398 "r1 = r10;"
1399 "r1 += -8;"
1400 "call %[bpf_iter_num_destroy];"
1401 "r0 = 0;"
1402 "exit;"
1403 :
1404 : __imm(bpf_map_lookup_elem),
1405 __imm(bpf_iter_num_new),
1406 __imm(bpf_iter_num_next),
1407 __imm(bpf_iter_num_destroy),
1408 __imm_addr(amap)
1409 : __clobber_all
1410 );
1411}
1412
1413struct {
1414 int data[32];
1415 int n;
1416} loop_data;
1417
1418SEC("raw_tp")
1419__success
1420int iter_arr_with_actual_elem_count(const void *ctx)
1421{
1422 int i, n = loop_data.n, sum = 0;
1423
1424 if (n > ARRAY_SIZE(loop_data.data))
1425 return 0;
1426
1427 bpf_for(i, 0, n) {
1428 /* no rechecking of i against ARRAY_SIZE(loop_data.n) */
1429 sum += loop_data.data[i];
1430 }
1431
1432 return sum;
1433}
1434
1435__u32 upper, select_n, result;
1436__u64 global;
1437
1438static __noinline bool nest_2(char *str)
1439{
1440 /* some insns (including branch insns) to ensure stacksafe() is triggered
1441 * in nest_2(). This way, stacksafe() can compare frame associated with nest_1().
1442 */
1443 if (str[0] == 't')
1444 return true;
1445 if (str[1] == 'e')
1446 return true;
1447 if (str[2] == 's')
1448 return true;
1449 if (str[3] == 't')
1450 return true;
1451 return false;
1452}
1453
1454static __noinline bool nest_1(int n)
1455{
1456 /* case 0: allocate stack, case 1: no allocate stack */
1457 switch (n) {
1458 case 0: {
1459 char comm[16];
1460
1461 if (bpf_get_current_comm(comm, 16))
1462 return false;
1463 return nest_2(comm);
1464 }
1465 case 1:
1466 return nest_2((char *)&global);
1467 default:
1468 return false;
1469 }
1470}
1471
1472SEC("raw_tp")
1473__success
1474int iter_subprog_check_stacksafe(const void *ctx)
1475{
1476 long i;
1477
1478 bpf_for(i, 0, upper) {
1479 if (!nest_1(select_n)) {
1480 result = 1;
1481 return 0;
1482 }
1483 }
1484
1485 result = 2;
1486 return 0;
1487}
1488
1489struct bpf_iter_num global_it;
1490
1491SEC("raw_tp")
1492__failure __msg("arg#0 expected pointer to an iterator on stack")
1493int iter_new_bad_arg(const void *ctx)
1494{
1495 bpf_iter_num_new(&global_it, 0, 1);
1496 return 0;
1497}
1498
1499SEC("raw_tp")
1500__failure __msg("arg#0 expected pointer to an iterator on stack")
1501int iter_next_bad_arg(const void *ctx)
1502{
1503 bpf_iter_num_next(&global_it);
1504 return 0;
1505}
1506
1507SEC("raw_tp")
1508__failure __msg("arg#0 expected pointer to an iterator on stack")
1509int iter_destroy_bad_arg(const void *ctx)
1510{
1511 bpf_iter_num_destroy(&global_it);
1512 return 0;
1513}
1514
1515char _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";