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1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/bpf.h>
4#include <bpf/bpf_helpers.h>
5#include "bpf_misc.h"
6
7/* Check that precision marks propagate through scalar IDs.
8 * Registers r{0,1,2} have the same scalar ID.
9 * Range information is propagated for scalars sharing same ID.
10 * Check that precision mark for r0 causes precision marks for r{1,2}
11 * when range information is propagated for 'if <reg> <op> <const>' insn.
12 */
13SEC("socket")
14__success __log_level(2)
15/* first 'if' branch */
16__msg("6: (0f) r3 += r0")
17__msg("frame0: regs=r0 stack= before 4: (25) if r1 > 0x7 goto pc+0")
18__msg("frame0: parent state regs=r0,r1,r2 stack=:")
19__msg("frame0: regs=r0,r1,r2 stack= before 3: (bf) r2 = r0")
20/* second 'if' branch */
21__msg("from 4 to 5: ")
22__msg("6: (0f) r3 += r0")
23__msg("frame0: regs=r0 stack= before 5: (bf) r3 = r10")
24__msg("frame0: regs=r0 stack= before 4: (25) if r1 > 0x7 goto pc+0")
25/* parent state already has r{0,1,2} as precise */
26__msg("frame0: parent state regs= stack=:")
27__flag(BPF_F_TEST_STATE_FREQ)
28__naked void linked_regs_bpf_k(void)
29{
30 asm volatile (
31 /* r0 = random number up to 0xff */
32 "call %[bpf_ktime_get_ns];"
33 "r0 &= 0xff;"
34 /* tie r0.id == r1.id == r2.id */
35 "r1 = r0;"
36 "r2 = r0;"
37 "if r1 > 7 goto +0;"
38 /* force r0 to be precise, this eventually marks r1 and r2 as
39 * precise as well because of shared IDs
40 */
41 "r3 = r10;"
42 "r3 += r0;"
43 "r0 = 0;"
44 "exit;"
45 :
46 : __imm(bpf_ktime_get_ns)
47 : __clobber_all);
48}
49
50/* Registers r{0,1,2} share same ID when 'if r1 > ...' insn is processed,
51 * check that verifier marks r{1,2} as precise while backtracking
52 * 'if r1 > ...' with r0 already marked.
53 */
54SEC("socket")
55__success __log_level(2)
56__flag(BPF_F_TEST_STATE_FREQ)
57__msg("frame0: regs=r0 stack= before 5: (2d) if r1 > r3 goto pc+0")
58__msg("frame0: parent state regs=r0,r1,r2,r3 stack=:")
59__msg("frame0: regs=r0,r1,r2,r3 stack= before 4: (b7) r3 = 7")
60__naked void linked_regs_bpf_x_src(void)
61{
62 asm volatile (
63 /* r0 = random number up to 0xff */
64 "call %[bpf_ktime_get_ns];"
65 "r0 &= 0xff;"
66 /* tie r0.id == r1.id == r2.id */
67 "r1 = r0;"
68 "r2 = r0;"
69 "r3 = 7;"
70 "if r1 > r3 goto +0;"
71 /* force r0 to be precise, this eventually marks r1 and r2 as
72 * precise as well because of shared IDs
73 */
74 "r4 = r10;"
75 "r4 += r0;"
76 "r0 = 0;"
77 "exit;"
78 :
79 : __imm(bpf_ktime_get_ns)
80 : __clobber_all);
81}
82
83/* Registers r{0,1,2} share same ID when 'if r1 > r3' insn is processed,
84 * check that verifier marks r{0,1,2} as precise while backtracking
85 * 'if r1 > r3' with r3 already marked.
86 */
87SEC("socket")
88__success __log_level(2)
89__flag(BPF_F_TEST_STATE_FREQ)
90__msg("frame0: regs=r3 stack= before 5: (2d) if r1 > r3 goto pc+0")
91__msg("frame0: parent state regs=r0,r1,r2,r3 stack=:")
92__msg("frame0: regs=r0,r1,r2,r3 stack= before 4: (b7) r3 = 7")
93__naked void linked_regs_bpf_x_dst(void)
94{
95 asm volatile (
96 /* r0 = random number up to 0xff */
97 "call %[bpf_ktime_get_ns];"
98 "r0 &= 0xff;"
99 /* tie r0.id == r1.id == r2.id */
100 "r1 = r0;"
101 "r2 = r0;"
102 "r3 = 7;"
103 "if r1 > r3 goto +0;"
104 /* force r0 to be precise, this eventually marks r1 and r2 as
105 * precise as well because of shared IDs
106 */
107 "r4 = r10;"
108 "r4 += r3;"
109 "r0 = 0;"
110 "exit;"
111 :
112 : __imm(bpf_ktime_get_ns)
113 : __clobber_all);
114}
115
116/* Same as linked_regs_bpf_k, but break one of the
117 * links, note that r1 is absent from regs=... in __msg below.
118 */
119SEC("socket")
120__success __log_level(2)
121__msg("7: (0f) r3 += r0")
122__msg("frame0: regs=r0 stack= before 6: (bf) r3 = r10")
123__msg("frame0: parent state regs=r0 stack=:")
124__msg("frame0: regs=r0 stack= before 5: (25) if r0 > 0x7 goto pc+0")
125__msg("frame0: parent state regs=r0,r2 stack=:")
126__flag(BPF_F_TEST_STATE_FREQ)
127__naked void linked_regs_broken_link(void)
128{
129 asm volatile (
130 /* r0 = random number up to 0xff */
131 "call %[bpf_ktime_get_ns];"
132 "r0 &= 0xff;"
133 /* tie r0.id == r1.id == r2.id */
134 "r1 = r0;"
135 "r2 = r0;"
136 /* break link for r1, this is the only line that differs
137 * compared to the previous test
138 */
139 "r1 = 0;"
140 "if r0 > 7 goto +0;"
141 /* force r0 to be precise,
142 * this eventually marks r2 as precise because of shared IDs
143 */
144 "r3 = r10;"
145 "r3 += r0;"
146 "r0 = 0;"
147 "exit;"
148 :
149 : __imm(bpf_ktime_get_ns)
150 : __clobber_all);
151}
152
153/* Check that precision marks propagate through scalar IDs.
154 * Use the same scalar ID in multiple stack frames, check that
155 * precision information is propagated up the call stack.
156 */
157SEC("socket")
158__success __log_level(2)
159__msg("12: (0f) r2 += r1")
160/* Current state */
161__msg("frame2: last_idx 12 first_idx 11 subseq_idx -1 ")
162__msg("frame2: regs=r1 stack= before 11: (bf) r2 = r10")
163__msg("frame2: parent state regs=r1 stack=")
164__msg("frame1: parent state regs= stack=")
165__msg("frame0: parent state regs= stack=")
166/* Parent state */
167__msg("frame2: last_idx 10 first_idx 10 subseq_idx 11 ")
168__msg("frame2: regs=r1 stack= before 10: (25) if r1 > 0x7 goto pc+0")
169__msg("frame2: parent state regs=r1 stack=")
170/* frame1.r{6,7} are marked because mark_precise_scalar_ids()
171 * looks for all registers with frame2.r1.id in the current state
172 */
173__msg("frame1: parent state regs=r6,r7 stack=")
174__msg("frame0: parent state regs=r6 stack=")
175/* Parent state */
176__msg("frame2: last_idx 8 first_idx 8 subseq_idx 10")
177__msg("frame2: regs=r1 stack= before 8: (85) call pc+1")
178/* frame1.r1 is marked because of backtracking of call instruction */
179__msg("frame1: parent state regs=r1,r6,r7 stack=")
180__msg("frame0: parent state regs=r6 stack=")
181/* Parent state */
182__msg("frame1: last_idx 7 first_idx 6 subseq_idx 8")
183__msg("frame1: regs=r1,r6,r7 stack= before 7: (bf) r7 = r1")
184__msg("frame1: regs=r1,r6 stack= before 6: (bf) r6 = r1")
185__msg("frame1: parent state regs=r1 stack=")
186__msg("frame0: parent state regs=r6 stack=")
187/* Parent state */
188__msg("frame1: last_idx 4 first_idx 4 subseq_idx 6")
189__msg("frame1: regs=r1 stack= before 4: (85) call pc+1")
190__msg("frame0: parent state regs=r1,r6 stack=")
191/* Parent state */
192__msg("frame0: last_idx 3 first_idx 1 subseq_idx 4")
193__msg("frame0: regs=r1,r6 stack= before 3: (bf) r6 = r0")
194__msg("frame0: regs=r0,r1 stack= before 2: (bf) r1 = r0")
195__msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255")
196__flag(BPF_F_TEST_STATE_FREQ)
197__naked void precision_many_frames(void)
198{
199 asm volatile (
200 /* r0 = random number up to 0xff */
201 "call %[bpf_ktime_get_ns];"
202 "r0 &= 0xff;"
203 /* tie r0.id == r1.id == r6.id */
204 "r1 = r0;"
205 "r6 = r0;"
206 "call precision_many_frames__foo;"
207 "exit;"
208 :
209 : __imm(bpf_ktime_get_ns)
210 : __clobber_all);
211}
212
213static __naked __noinline __used
214void precision_many_frames__foo(void)
215{
216 asm volatile (
217 /* conflate one of the register numbers (r6) with outer frame,
218 * to verify that those are tracked independently
219 */
220 "r6 = r1;"
221 "r7 = r1;"
222 "call precision_many_frames__bar;"
223 "exit"
224 ::: __clobber_all);
225}
226
227static __naked __noinline __used
228void precision_many_frames__bar(void)
229{
230 asm volatile (
231 "if r1 > 7 goto +0;"
232 /* force r1 to be precise, this eventually marks:
233 * - bar frame r1
234 * - foo frame r{1,6,7}
235 * - main frame r{1,6}
236 */
237 "r2 = r10;"
238 "r2 += r1;"
239 "r0 = 0;"
240 "exit;"
241 ::: __clobber_all);
242}
243
244/* Check that scalars with the same IDs are marked precise on stack as
245 * well as in registers.
246 */
247SEC("socket")
248__success __log_level(2)
249__msg("11: (0f) r2 += r1")
250/* foo frame */
251__msg("frame1: regs=r1 stack= before 10: (bf) r2 = r10")
252__msg("frame1: regs=r1 stack= before 9: (25) if r1 > 0x7 goto pc+0")
253__msg("frame1: regs=r1 stack=-8,-16 before 8: (7b) *(u64 *)(r10 -16) = r1")
254__msg("frame1: regs=r1 stack=-8 before 7: (7b) *(u64 *)(r10 -8) = r1")
255__msg("frame1: regs=r1 stack= before 4: (85) call pc+2")
256/* main frame */
257__msg("frame0: regs=r1 stack=-8 before 3: (7b) *(u64 *)(r10 -8) = r1")
258__msg("frame0: regs=r1 stack= before 2: (bf) r1 = r0")
259__msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255")
260__flag(BPF_F_TEST_STATE_FREQ)
261__naked void precision_stack(void)
262{
263 asm volatile (
264 /* r0 = random number up to 0xff */
265 "call %[bpf_ktime_get_ns];"
266 "r0 &= 0xff;"
267 /* tie r0.id == r1.id == fp[-8].id */
268 "r1 = r0;"
269 "*(u64*)(r10 - 8) = r1;"
270 "call precision_stack__foo;"
271 "r0 = 0;"
272 "exit;"
273 :
274 : __imm(bpf_ktime_get_ns)
275 : __clobber_all);
276}
277
278static __naked __noinline __used
279void precision_stack__foo(void)
280{
281 asm volatile (
282 /* conflate one of the register numbers (r6) with outer frame,
283 * to verify that those are tracked independently
284 */
285 "*(u64*)(r10 - 8) = r1;"
286 "*(u64*)(r10 - 16) = r1;"
287 "if r1 > 7 goto +0;"
288 /* force r1 to be precise, this eventually marks:
289 * - foo frame r1,fp{-8,-16}
290 * - main frame r1,fp{-8}
291 */
292 "r2 = r10;"
293 "r2 += r1;"
294 "exit"
295 ::: __clobber_all);
296}
297
298/* Use two separate scalar IDs to check that these are propagated
299 * independently.
300 */
301SEC("socket")
302__success __log_level(2)
303/* r{6,7} */
304__msg("12: (0f) r3 += r7")
305__msg("frame0: regs=r7 stack= before 11: (bf) r3 = r10")
306__msg("frame0: regs=r7 stack= before 9: (25) if r7 > 0x7 goto pc+0")
307/* ... skip some insns ... */
308__msg("frame0: regs=r6,r7 stack= before 3: (bf) r7 = r0")
309__msg("frame0: regs=r0,r6 stack= before 2: (bf) r6 = r0")
310/* r{8,9} */
311__msg("13: (0f) r3 += r9")
312__msg("frame0: regs=r9 stack= before 12: (0f) r3 += r7")
313/* ... skip some insns ... */
314__msg("frame0: regs=r9 stack= before 10: (25) if r9 > 0x7 goto pc+0")
315__msg("frame0: regs=r8,r9 stack= before 7: (bf) r9 = r0")
316__msg("frame0: regs=r0,r8 stack= before 6: (bf) r8 = r0")
317__flag(BPF_F_TEST_STATE_FREQ)
318__naked void precision_two_ids(void)
319{
320 asm volatile (
321 /* r6 = random number up to 0xff
322 * r6.id == r7.id
323 */
324 "call %[bpf_ktime_get_ns];"
325 "r0 &= 0xff;"
326 "r6 = r0;"
327 "r7 = r0;"
328 /* same, but for r{8,9} */
329 "call %[bpf_ktime_get_ns];"
330 "r0 &= 0xff;"
331 "r8 = r0;"
332 "r9 = r0;"
333 /* clear r0 id */
334 "r0 = 0;"
335 /* propagate equal scalars precision */
336 "if r7 > 7 goto +0;"
337 "if r9 > 7 goto +0;"
338 "r3 = r10;"
339 /* force r7 to be precise, this also marks r6 */
340 "r3 += r7;"
341 /* force r9 to be precise, this also marks r8 */
342 "r3 += r9;"
343 "exit;"
344 :
345 : __imm(bpf_ktime_get_ns)
346 : __clobber_all);
347}
348
349SEC("socket")
350__success __log_level(2)
351__flag(BPF_F_TEST_STATE_FREQ)
352/* check thar r0 and r6 have different IDs after 'if',
353 * collect_linked_regs() can't tie more than 6 registers for a single insn.
354 */
355__msg("8: (25) if r0 > 0x7 goto pc+0 ; R0=scalar(id=1")
356__msg("9: (bf) r6 = r6 ; R6_w=scalar(id=2")
357/* check that r{0-5} are marked precise after 'if' */
358__msg("frame0: regs=r0 stack= before 8: (25) if r0 > 0x7 goto pc+0")
359__msg("frame0: parent state regs=r0,r1,r2,r3,r4,r5 stack=:")
360__naked void linked_regs_too_many_regs(void)
361{
362 asm volatile (
363 /* r0 = random number up to 0xff */
364 "call %[bpf_ktime_get_ns];"
365 "r0 &= 0xff;"
366 /* tie r{0-6} IDs */
367 "r1 = r0;"
368 "r2 = r0;"
369 "r3 = r0;"
370 "r4 = r0;"
371 "r5 = r0;"
372 "r6 = r0;"
373 /* propagate range for r{0-6} */
374 "if r0 > 7 goto +0;"
375 /* make r6 appear in the log */
376 "r6 = r6;"
377 /* force r0 to be precise,
378 * this would cause r{0-4} to be precise because of shared IDs
379 */
380 "r7 = r10;"
381 "r7 += r0;"
382 "r0 = 0;"
383 "exit;"
384 :
385 : __imm(bpf_ktime_get_ns)
386 : __clobber_all);
387}
388
389SEC("socket")
390__failure __log_level(2)
391__flag(BPF_F_TEST_STATE_FREQ)
392__msg("regs=r7 stack= before 5: (3d) if r8 >= r0")
393__msg("parent state regs=r0,r7,r8")
394__msg("regs=r0,r7,r8 stack= before 4: (25) if r0 > 0x1")
395__msg("div by zero")
396__naked void linked_regs_broken_link_2(void)
397{
398 asm volatile (
399 "call %[bpf_get_prandom_u32];"
400 "r7 = r0;"
401 "r8 = r0;"
402 "call %[bpf_get_prandom_u32];"
403 "if r0 > 1 goto +0;"
404 /* r7.id == r8.id,
405 * thus r7 precision implies r8 precision,
406 * which implies r0 precision because of the conditional below.
407 */
408 "if r8 >= r0 goto 1f;"
409 /* break id relation between r7 and r8 */
410 "r8 += r8;"
411 /* make r7 precise */
412 "if r7 == 0 goto 1f;"
413 "r0 /= 0;"
414"1:"
415 "r0 = 42;"
416 "exit;"
417 :
418 : __imm(bpf_get_prandom_u32)
419 : __clobber_all);
420}
421
422/* Check that mark_chain_precision() for one of the conditional jump
423 * operands does not trigger equal scalars precision propagation.
424 */
425SEC("socket")
426__success __log_level(2)
427__msg("3: (25) if r1 > 0x100 goto pc+0")
428__msg("frame0: regs=r1 stack= before 2: (bf) r1 = r0")
429__naked void cjmp_no_linked_regs_trigger(void)
430{
431 asm volatile (
432 /* r0 = random number up to 0xff */
433 "call %[bpf_ktime_get_ns];"
434 "r0 &= 0xff;"
435 /* tie r0.id == r1.id */
436 "r1 = r0;"
437 /* the jump below would be predicted, thus r1 would be marked precise,
438 * this should not imply precision mark for r0
439 */
440 "if r1 > 256 goto +0;"
441 "r0 = 0;"
442 "exit;"
443 :
444 : __imm(bpf_ktime_get_ns)
445 : __clobber_all);
446}
447
448/* Verify that check_ids() is used by regsafe() for scalars.
449 *
450 * r9 = ... some pointer with range X ...
451 * r6 = ... unbound scalar ID=a ...
452 * r7 = ... unbound scalar ID=b ...
453 * if (r6 > r7) goto +1
454 * r7 = r6
455 * if (r7 > X) goto exit
456 * r9 += r6
457 * ... access memory using r9 ...
458 *
459 * The memory access is safe only if r7 is bounded,
460 * which is true for one branch and not true for another.
461 */
462SEC("socket")
463__failure __msg("register with unbounded min value")
464__flag(BPF_F_TEST_STATE_FREQ)
465__naked void check_ids_in_regsafe(void)
466{
467 asm volatile (
468 /* Bump allocated stack */
469 "r1 = 0;"
470 "*(u64*)(r10 - 8) = r1;"
471 /* r9 = pointer to stack */
472 "r9 = r10;"
473 "r9 += -8;"
474 /* r7 = ktime_get_ns() */
475 "call %[bpf_ktime_get_ns];"
476 "r7 = r0;"
477 /* r6 = ktime_get_ns() */
478 "call %[bpf_ktime_get_ns];"
479 "r6 = r0;"
480 /* if r6 > r7 is an unpredictable jump */
481 "if r6 > r7 goto l1_%=;"
482 "r7 = r6;"
483"l1_%=:"
484 /* if r7 > 4 ...; transfers range to r6 on one execution path
485 * but does not transfer on another
486 */
487 "if r7 > 4 goto l2_%=;"
488 /* Access memory at r9[r6], r6 is not always bounded */
489 "r9 += r6;"
490 "r0 = *(u8*)(r9 + 0);"
491"l2_%=:"
492 "r0 = 0;"
493 "exit;"
494 :
495 : __imm(bpf_ktime_get_ns)
496 : __clobber_all);
497}
498
499/* Similar to check_ids_in_regsafe.
500 * The l0 could be reached in two states:
501 *
502 * (1) r6{.id=A}, r7{.id=A}, r8{.id=B}
503 * (2) r6{.id=B}, r7{.id=A}, r8{.id=B}
504 *
505 * Where (2) is not safe, as "r7 > 4" check won't propagate range for it.
506 * This example would be considered safe without changes to
507 * mark_chain_precision() to track scalar values with equal IDs.
508 */
509SEC("socket")
510__failure __msg("register with unbounded min value")
511__flag(BPF_F_TEST_STATE_FREQ)
512__naked void check_ids_in_regsafe_2(void)
513{
514 asm volatile (
515 /* Bump allocated stack */
516 "r1 = 0;"
517 "*(u64*)(r10 - 8) = r1;"
518 /* r9 = pointer to stack */
519 "r9 = r10;"
520 "r9 += -8;"
521 /* r8 = ktime_get_ns() */
522 "call %[bpf_ktime_get_ns];"
523 "r8 = r0;"
524 /* r7 = ktime_get_ns() */
525 "call %[bpf_ktime_get_ns];"
526 "r7 = r0;"
527 /* r6 = ktime_get_ns() */
528 "call %[bpf_ktime_get_ns];"
529 "r6 = r0;"
530 /* scratch .id from r0 */
531 "r0 = 0;"
532 /* if r6 > r7 is an unpredictable jump */
533 "if r6 > r7 goto l1_%=;"
534 /* tie r6 and r7 .id */
535 "r6 = r7;"
536"l0_%=:"
537 /* if r7 > 4 exit(0) */
538 "if r7 > 4 goto l2_%=;"
539 /* Access memory at r9[r6] */
540 "r9 += r6;"
541 "r0 = *(u8*)(r9 + 0);"
542"l2_%=:"
543 "r0 = 0;"
544 "exit;"
545"l1_%=:"
546 /* tie r6 and r8 .id */
547 "r6 = r8;"
548 "goto l0_%=;"
549 :
550 : __imm(bpf_ktime_get_ns)
551 : __clobber_all);
552}
553
554/* Check that scalar IDs *are not* generated on register to register
555 * assignments if source register is a constant.
556 *
557 * If such IDs *are* generated the 'l1' below would be reached in
558 * two states:
559 *
560 * (1) r1{.id=A}, r2{.id=A}
561 * (2) r1{.id=C}, r2{.id=C}
562 *
563 * Thus forcing 'if r1 == r2' verification twice.
564 */
565SEC("socket")
566__success __log_level(2)
567__msg("11: (1d) if r3 == r4 goto pc+0")
568__msg("frame 0: propagating r3,r4")
569__msg("11: safe")
570__msg("processed 15 insns")
571__flag(BPF_F_TEST_STATE_FREQ)
572__naked void no_scalar_id_for_const(void)
573{
574 asm volatile (
575 "call %[bpf_ktime_get_ns];"
576 /* unpredictable jump */
577 "if r0 > 7 goto l0_%=;"
578 /* possibly generate same scalar ids for r3 and r4 */
579 "r1 = 0;"
580 "r1 = r1;"
581 "r3 = r1;"
582 "r4 = r1;"
583 "goto l1_%=;"
584"l0_%=:"
585 /* possibly generate different scalar ids for r3 and r4 */
586 "r1 = 0;"
587 "r2 = 0;"
588 "r3 = r1;"
589 "r4 = r2;"
590"l1_%=:"
591 /* predictable jump, marks r3 and r4 precise */
592 "if r3 == r4 goto +0;"
593 "r0 = 0;"
594 "exit;"
595 :
596 : __imm(bpf_ktime_get_ns)
597 : __clobber_all);
598}
599
600/* Same as no_scalar_id_for_const() but for 32-bit values */
601SEC("socket")
602__success __log_level(2)
603__msg("11: (1e) if w3 == w4 goto pc+0")
604__msg("frame 0: propagating r3,r4")
605__msg("11: safe")
606__msg("processed 15 insns")
607__flag(BPF_F_TEST_STATE_FREQ)
608__naked void no_scalar_id_for_const32(void)
609{
610 asm volatile (
611 "call %[bpf_ktime_get_ns];"
612 /* unpredictable jump */
613 "if r0 > 7 goto l0_%=;"
614 /* possibly generate same scalar ids for r3 and r4 */
615 "w1 = 0;"
616 "w1 = w1;"
617 "w3 = w1;"
618 "w4 = w1;"
619 "goto l1_%=;"
620"l0_%=:"
621 /* possibly generate different scalar ids for r3 and r4 */
622 "w1 = 0;"
623 "w2 = 0;"
624 "w3 = w1;"
625 "w4 = w2;"
626"l1_%=:"
627 /* predictable jump, marks r1 and r2 precise */
628 "if w3 == w4 goto +0;"
629 "r0 = 0;"
630 "exit;"
631 :
632 : __imm(bpf_ktime_get_ns)
633 : __clobber_all);
634}
635
636/* Check that unique scalar IDs are ignored when new verifier state is
637 * compared to cached verifier state. For this test:
638 * - cached state has no id on r1
639 * - new state has a unique id on r1
640 */
641SEC("socket")
642__success __log_level(2)
643__msg("6: (25) if r6 > 0x7 goto pc+1")
644__msg("7: (57) r1 &= 255")
645__msg("8: (bf) r2 = r10")
646__msg("from 6 to 8: safe")
647__msg("processed 12 insns")
648__flag(BPF_F_TEST_STATE_FREQ)
649__naked void ignore_unique_scalar_ids_cur(void)
650{
651 asm volatile (
652 "call %[bpf_ktime_get_ns];"
653 "r6 = r0;"
654 "call %[bpf_ktime_get_ns];"
655 "r0 &= 0xff;"
656 /* r1.id == r0.id */
657 "r1 = r0;"
658 /* make r1.id unique */
659 "r0 = 0;"
660 "if r6 > 7 goto l0_%=;"
661 /* clear r1 id, but keep the range compatible */
662 "r1 &= 0xff;"
663"l0_%=:"
664 /* get here in two states:
665 * - first: r1 has no id (cached state)
666 * - second: r1 has a unique id (should be considered equivalent)
667 */
668 "r2 = r10;"
669 "r2 += r1;"
670 "exit;"
671 :
672 : __imm(bpf_ktime_get_ns)
673 : __clobber_all);
674}
675
676/* Check that unique scalar IDs are ignored when new verifier state is
677 * compared to cached verifier state. For this test:
678 * - cached state has a unique id on r1
679 * - new state has no id on r1
680 */
681SEC("socket")
682__success __log_level(2)
683__msg("6: (25) if r6 > 0x7 goto pc+1")
684__msg("7: (05) goto pc+1")
685__msg("9: (bf) r2 = r10")
686__msg("9: safe")
687__msg("processed 13 insns")
688__flag(BPF_F_TEST_STATE_FREQ)
689__naked void ignore_unique_scalar_ids_old(void)
690{
691 asm volatile (
692 "call %[bpf_ktime_get_ns];"
693 "r6 = r0;"
694 "call %[bpf_ktime_get_ns];"
695 "r0 &= 0xff;"
696 /* r1.id == r0.id */
697 "r1 = r0;"
698 /* make r1.id unique */
699 "r0 = 0;"
700 "if r6 > 7 goto l1_%=;"
701 "goto l0_%=;"
702"l1_%=:"
703 /* clear r1 id, but keep the range compatible */
704 "r1 &= 0xff;"
705"l0_%=:"
706 /* get here in two states:
707 * - first: r1 has a unique id (cached state)
708 * - second: r1 has no id (should be considered equivalent)
709 */
710 "r2 = r10;"
711 "r2 += r1;"
712 "exit;"
713 :
714 : __imm(bpf_ktime_get_ns)
715 : __clobber_all);
716}
717
718/* Check that two different scalar IDs in a verified state can't be
719 * mapped to the same scalar ID in current state.
720 */
721SEC("socket")
722__success __log_level(2)
723/* The exit instruction should be reachable from two states,
724 * use two matches and "processed .. insns" to ensure this.
725 */
726__msg("13: (95) exit")
727__msg("13: (95) exit")
728__msg("processed 18 insns")
729__flag(BPF_F_TEST_STATE_FREQ)
730__naked void two_old_ids_one_cur_id(void)
731{
732 asm volatile (
733 /* Give unique scalar IDs to r{6,7} */
734 "call %[bpf_ktime_get_ns];"
735 "r0 &= 0xff;"
736 "r6 = r0;"
737 "call %[bpf_ktime_get_ns];"
738 "r0 &= 0xff;"
739 "r7 = r0;"
740 "r0 = 0;"
741 /* Maybe make r{6,7} IDs identical */
742 "if r6 > r7 goto l0_%=;"
743 "goto l1_%=;"
744"l0_%=:"
745 "r6 = r7;"
746"l1_%=:"
747 /* Mark r{6,7} precise.
748 * Get here in two states:
749 * - first: r6{.id=A}, r7{.id=B} (cached state)
750 * - second: r6{.id=A}, r7{.id=A}
751 * Currently we don't want to consider such states equivalent.
752 * Thus "exit;" would be verified twice.
753 */
754 "r2 = r10;"
755 "r2 += r6;"
756 "r2 += r7;"
757 "exit;"
758 :
759 : __imm(bpf_ktime_get_ns)
760 : __clobber_all);
761}
762
763SEC("socket")
764/* Note the flag, see verifier.c:opt_subreg_zext_lo32_rnd_hi32() */
765__flag(BPF_F_TEST_RND_HI32)
766__success
767/* This test was added because of a bug in verifier.c:sync_linked_regs(),
768 * upon range propagation it destroyed subreg_def marks for registers.
769 * The subreg_def mark is used to decide whether zero extension instructions
770 * are needed when register is read. When BPF_F_TEST_RND_HI32 is set it
771 * also causes generation of statements to randomize upper halves of
772 * read registers.
773 *
774 * The test is written in a way to return an upper half of a register
775 * that is affected by range propagation and must have it's subreg_def
776 * preserved. This gives a return value of 0 and leads to undefined
777 * return value if subreg_def mark is not preserved.
778 */
779__retval(0)
780/* Check that verifier believes r1/r0 are zero at exit */
781__log_level(2)
782__msg("4: (77) r1 >>= 32 ; R1_w=0")
783__msg("5: (bf) r0 = r1 ; R0_w=0 R1_w=0")
784__msg("6: (95) exit")
785__msg("from 3 to 4")
786__msg("4: (77) r1 >>= 32 ; R1_w=0")
787__msg("5: (bf) r0 = r1 ; R0_w=0 R1_w=0")
788__msg("6: (95) exit")
789/* Verify that statements to randomize upper half of r1 had not been
790 * generated.
791 */
792__xlated("call unknown")
793__xlated("r0 &= 2147483647")
794__xlated("w1 = w0")
795/* This is how disasm.c prints BPF_ZEXT_REG at the moment, x86 and arm
796 * are the only CI archs that do not need zero extension for subregs.
797 */
798#if !defined(__TARGET_ARCH_x86) && !defined(__TARGET_ARCH_arm64)
799__xlated("w1 = w1")
800#endif
801__xlated("if w0 < 0xa goto pc+0")
802__xlated("r1 >>= 32")
803__xlated("r0 = r1")
804__xlated("exit")
805__naked void linked_regs_and_subreg_def(void)
806{
807 asm volatile (
808 "call %[bpf_ktime_get_ns];"
809 /* make sure r0 is in 32-bit range, otherwise w1 = w0 won't
810 * assign same IDs to registers.
811 */
812 "r0 &= 0x7fffffff;"
813 /* link w1 and w0 via ID */
814 "w1 = w0;"
815 /* 'if' statement propagates range info from w0 to w1,
816 * but should not affect w1->subreg_def property.
817 */
818 "if w0 < 10 goto +0;"
819 /* r1 is read here, on archs that require subreg zero
820 * extension this would cause zext patch generation.
821 */
822 "r1 >>= 32;"
823 "r0 = r1;"
824 "exit;"
825 :
826 : __imm(bpf_ktime_get_ns)
827 : __clobber_all);
828}
829
830char _license[] SEC("license") = "GPL";