1 // SPDX-License-Identifier: GPL-2.0
4 #include <bpf/bpf_helpers.h>
7 /* Check that precision marks propagate through scalar IDs.
8 * Registers r{0,1,2} have the same scalar ID at the moment when r0 is
9 * marked to be precise, this mark is immediately propagated to r{1,2}.
12 __success __log_level(2)
13 __msg("frame0: regs=r0,r1,r2 stack= before 4: (bf) r3 = r10")
14 __msg("frame0: regs=r0,r1,r2 stack= before 3: (bf) r2 = r0")
15 __msg("frame0: regs=r0,r1 stack= before 2: (bf) r1 = r0")
16 __msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255")
17 __msg("frame0: regs=r0 stack= before 0: (85) call bpf_ktime_get_ns")
18 __flag(BPF_F_TEST_STATE_FREQ)
19 __naked void precision_same_state(void)
22 /* r0 = random number up to 0xff */
23 "call %[bpf_ktime_get_ns];"
25 /* tie r0.id == r1.id == r2.id */
28 /* force r0 to be precise, this immediately marks r1 and r2 as
29 * precise as well because of shared IDs
36 : __imm(bpf_ktime_get_ns)
40 /* Same as precision_same_state, but mark propagates through state /
41 * parent state boundary.
44 __success __log_level(2)
45 __msg("frame0: last_idx 6 first_idx 5 subseq_idx -1")
46 __msg("frame0: regs=r0,r1,r2 stack= before 5: (bf) r3 = r10")
47 __msg("frame0: parent state regs=r0,r1,r2 stack=:")
48 __msg("frame0: regs=r0,r1,r2 stack= before 4: (05) goto pc+0")
49 __msg("frame0: regs=r0,r1,r2 stack= before 3: (bf) r2 = r0")
50 __msg("frame0: regs=r0,r1 stack= before 2: (bf) r1 = r0")
51 __msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255")
52 __msg("frame0: parent state regs=r0 stack=:")
53 __msg("frame0: regs=r0 stack= before 0: (85) call bpf_ktime_get_ns")
54 __flag(BPF_F_TEST_STATE_FREQ)
55 __naked void precision_cross_state(void)
58 /* r0 = random number up to 0xff */
59 "call %[bpf_ktime_get_ns];"
61 /* tie r0.id == r1.id == r2.id */
64 /* force checkpoint */
66 /* force r0 to be precise, this immediately marks r1 and r2 as
67 * precise as well because of shared IDs
74 : __imm(bpf_ktime_get_ns)
78 /* Same as precision_same_state, but break one of the
79 * links, note that r1 is absent from regs=... in __msg below.
82 __success __log_level(2)
83 __msg("frame0: regs=r0,r2 stack= before 5: (bf) r3 = r10")
84 __msg("frame0: regs=r0,r2 stack= before 4: (b7) r1 = 0")
85 __msg("frame0: regs=r0,r2 stack= before 3: (bf) r2 = r0")
86 __msg("frame0: regs=r0 stack= before 2: (bf) r1 = r0")
87 __msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255")
88 __msg("frame0: regs=r0 stack= before 0: (85) call bpf_ktime_get_ns")
89 __flag(BPF_F_TEST_STATE_FREQ)
90 __naked void precision_same_state_broken_link(void)
93 /* r0 = random number up to 0xff */
94 "call %[bpf_ktime_get_ns];"
96 /* tie r0.id == r1.id == r2.id */
99 /* break link for r1, this is the only line that differs
100 * compared to the previous test
103 /* force r0 to be precise, this immediately marks r1 and r2 as
104 * precise as well because of shared IDs
111 : __imm(bpf_ktime_get_ns)
115 /* Same as precision_same_state_broken_link, but with state /
116 * parent state boundary.
119 __success __log_level(2)
120 __msg("frame0: regs=r0,r2 stack= before 6: (bf) r3 = r10")
121 __msg("frame0: regs=r0,r2 stack= before 5: (b7) r1 = 0")
122 __msg("frame0: parent state regs=r0,r2 stack=:")
123 __msg("frame0: regs=r0,r1,r2 stack= before 4: (05) goto pc+0")
124 __msg("frame0: regs=r0,r1,r2 stack= before 3: (bf) r2 = r0")
125 __msg("frame0: regs=r0,r1 stack= before 2: (bf) r1 = r0")
126 __msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255")
127 __msg("frame0: parent state regs=r0 stack=:")
128 __msg("frame0: regs=r0 stack= before 0: (85) call bpf_ktime_get_ns")
129 __flag(BPF_F_TEST_STATE_FREQ)
130 __naked void precision_cross_state_broken_link(void)
133 /* r0 = random number up to 0xff */
134 "call %[bpf_ktime_get_ns];"
136 /* tie r0.id == r1.id == r2.id */
139 /* force checkpoint, although link between r1 and r{0,2} is
140 * broken by the next statement current precision tracking
141 * algorithm can't react to it and propagates mark for r1 to
145 /* break link for r1, this is the only line that differs
146 * compared to precision_cross_state()
149 /* force r0 to be precise, this immediately marks r1 and r2 as
150 * precise as well because of shared IDs
157 : __imm(bpf_ktime_get_ns)
161 /* Check that precision marks propagate through scalar IDs.
162 * Use the same scalar ID in multiple stack frames, check that
163 * precision information is propagated up the call stack.
166 __success __log_level(2)
167 __msg("11: (0f) r2 += r1")
169 __msg("frame2: last_idx 11 first_idx 10 subseq_idx -1")
170 __msg("frame2: regs=r1 stack= before 10: (bf) r2 = r10")
171 __msg("frame2: parent state regs=r1 stack=")
172 /* frame1.r{6,7} are marked because mark_precise_scalar_ids()
173 * looks for all registers with frame2.r1.id in the current state
175 __msg("frame1: parent state regs=r6,r7 stack=")
176 __msg("frame0: parent state regs=r6 stack=")
178 __msg("frame2: last_idx 8 first_idx 8 subseq_idx 10")
179 __msg("frame2: regs=r1 stack= before 8: (85) call pc+1")
180 /* frame1.r1 is marked because of backtracking of call instruction */
181 __msg("frame1: parent state regs=r1,r6,r7 stack=")
182 __msg("frame0: parent state regs=r6 stack=")
184 __msg("frame1: last_idx 7 first_idx 6 subseq_idx 8")
185 __msg("frame1: regs=r1,r6,r7 stack= before 7: (bf) r7 = r1")
186 __msg("frame1: regs=r1,r6 stack= before 6: (bf) r6 = r1")
187 __msg("frame1: parent state regs=r1 stack=")
188 __msg("frame0: parent state regs=r6 stack=")
190 __msg("frame1: last_idx 4 first_idx 4 subseq_idx 6")
191 __msg("frame1: regs=r1 stack= before 4: (85) call pc+1")
192 __msg("frame0: parent state regs=r1,r6 stack=")
194 __msg("frame0: last_idx 3 first_idx 1 subseq_idx 4")
195 __msg("frame0: regs=r0,r1,r6 stack= before 3: (bf) r6 = r0")
196 __msg("frame0: regs=r0,r1 stack= before 2: (bf) r1 = r0")
197 __msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255")
198 __flag(BPF_F_TEST_STATE_FREQ)
199 __naked void precision_many_frames(void)
202 /* r0 = random number up to 0xff */
203 "call %[bpf_ktime_get_ns];"
205 /* tie r0.id == r1.id == r6.id */
208 "call precision_many_frames__foo;"
211 : __imm(bpf_ktime_get_ns)
215 static __naked __noinline __used
216 void precision_many_frames__foo(void)
219 /* conflate one of the register numbers (r6) with outer frame,
220 * to verify that those are tracked independently
224 "call precision_many_frames__bar;"
229 static __naked __noinline __used
230 void precision_many_frames__bar(void)
233 /* force r1 to be precise, this immediately marks:
235 * - foo frame r{1,6,7}
236 * - main frame r{1,6}
245 /* Check that scalars with the same IDs are marked precise on stack as
246 * well as in registers.
249 __success __log_level(2)
251 __msg("frame1: regs=r1 stack=-8,-16 before 9: (bf) r2 = r10")
252 __msg("frame1: regs=r1 stack=-8,-16 before 8: (7b) *(u64 *)(r10 -16) = r1")
253 __msg("frame1: regs=r1 stack=-8 before 7: (7b) *(u64 *)(r10 -8) = r1")
254 __msg("frame1: regs=r1 stack= before 4: (85) call pc+2")
256 __msg("frame0: regs=r0,r1 stack=-8 before 3: (7b) *(u64 *)(r10 -8) = r1")
257 __msg("frame0: regs=r0,r1 stack= before 2: (bf) r1 = r0")
258 __msg("frame0: regs=r0 stack= before 1: (57) r0 &= 255")
259 __flag(BPF_F_TEST_STATE_FREQ)
260 __naked void precision_stack(void)
263 /* r0 = random number up to 0xff */
264 "call %[bpf_ktime_get_ns];"
266 /* tie r0.id == r1.id == fp[-8].id */
268 "*(u64*)(r10 - 8) = r1;"
269 "call precision_stack__foo;"
273 : __imm(bpf_ktime_get_ns)
277 static __naked __noinline __used
278 void precision_stack__foo(void)
281 /* conflate one of the register numbers (r6) with outer frame,
282 * to verify that those are tracked independently
284 "*(u64*)(r10 - 8) = r1;"
285 "*(u64*)(r10 - 16) = r1;"
286 /* force r1 to be precise, this immediately marks:
287 * - foo frame r1,fp{-8,-16}
288 * - main frame r1,fp{-8}
296 /* Use two separate scalar IDs to check that these are propagated
300 __success __log_level(2)
302 __msg("11: (0f) r3 += r7")
303 __msg("frame0: regs=r6,r7 stack= before 10: (bf) r3 = r10")
304 /* ... skip some insns ... */
305 __msg("frame0: regs=r6,r7 stack= before 3: (bf) r7 = r0")
306 __msg("frame0: regs=r0,r6 stack= before 2: (bf) r6 = r0")
308 __msg("12: (0f) r3 += r9")
309 __msg("frame0: regs=r8,r9 stack= before 11: (0f) r3 += r7")
310 /* ... skip some insns ... */
311 __msg("frame0: regs=r8,r9 stack= before 7: (bf) r9 = r0")
312 __msg("frame0: regs=r0,r8 stack= before 6: (bf) r8 = r0")
313 __flag(BPF_F_TEST_STATE_FREQ)
314 __naked void precision_two_ids(void)
317 /* r6 = random number up to 0xff
320 "call %[bpf_ktime_get_ns];"
324 /* same, but for r{8,9} */
325 "call %[bpf_ktime_get_ns];"
331 /* force checkpoint */
334 /* force r7 to be precise, this also marks r6 */
336 /* force r9 to be precise, this also marks r8 */
340 : __imm(bpf_ktime_get_ns)
344 /* Verify that check_ids() is used by regsafe() for scalars.
346 * r9 = ... some pointer with range X ...
347 * r6 = ... unbound scalar ID=a ...
348 * r7 = ... unbound scalar ID=b ...
349 * if (r6 > r7) goto +1
351 * if (r7 > X) goto exit
353 * ... access memory using r9 ...
355 * The memory access is safe only if r7 is bounded,
356 * which is true for one branch and not true for another.
359 __failure __msg("register with unbounded min value")
360 __flag(BPF_F_TEST_STATE_FREQ)
361 __naked void check_ids_in_regsafe(void)
364 /* Bump allocated stack */
366 "*(u64*)(r10 - 8) = r1;"
367 /* r9 = pointer to stack */
370 /* r7 = ktime_get_ns() */
371 "call %[bpf_ktime_get_ns];"
373 /* r6 = ktime_get_ns() */
374 "call %[bpf_ktime_get_ns];"
376 /* if r6 > r7 is an unpredictable jump */
377 "if r6 > r7 goto l1_%=;"
380 /* if r7 > 4 ...; transfers range to r6 on one execution path
381 * but does not transfer on another
383 "if r7 > 4 goto l2_%=;"
384 /* Access memory at r9[r6], r6 is not always bounded */
386 "r0 = *(u8*)(r9 + 0);"
391 : __imm(bpf_ktime_get_ns)
395 /* Similar to check_ids_in_regsafe.
396 * The l0 could be reached in two states:
398 * (1) r6{.id=A}, r7{.id=A}, r8{.id=B}
399 * (2) r6{.id=B}, r7{.id=A}, r8{.id=B}
401 * Where (2) is not safe, as "r7 > 4" check won't propagate range for it.
402 * This example would be considered safe without changes to
403 * mark_chain_precision() to track scalar values with equal IDs.
406 __failure __msg("register with unbounded min value")
407 __flag(BPF_F_TEST_STATE_FREQ)
408 __naked void check_ids_in_regsafe_2(void)
411 /* Bump allocated stack */
413 "*(u64*)(r10 - 8) = r1;"
414 /* r9 = pointer to stack */
417 /* r8 = ktime_get_ns() */
418 "call %[bpf_ktime_get_ns];"
420 /* r7 = ktime_get_ns() */
421 "call %[bpf_ktime_get_ns];"
423 /* r6 = ktime_get_ns() */
424 "call %[bpf_ktime_get_ns];"
426 /* scratch .id from r0 */
428 /* if r6 > r7 is an unpredictable jump */
429 "if r6 > r7 goto l1_%=;"
430 /* tie r6 and r7 .id */
433 /* if r7 > 4 exit(0) */
434 "if r7 > 4 goto l2_%=;"
435 /* Access memory at r9[r6] */
437 "r0 = *(u8*)(r9 + 0);"
442 /* tie r6 and r8 .id */
446 : __imm(bpf_ktime_get_ns)
450 /* Check that scalar IDs *are not* generated on register to register
451 * assignments if source register is a constant.
453 * If such IDs *are* generated the 'l1' below would be reached in
456 * (1) r1{.id=A}, r2{.id=A}
457 * (2) r1{.id=C}, r2{.id=C}
459 * Thus forcing 'if r1 == r2' verification twice.
462 __success __log_level(2)
463 __msg("11: (1d) if r3 == r4 goto pc+0")
464 __msg("frame 0: propagating r3,r4")
466 __msg("processed 15 insns")
467 __flag(BPF_F_TEST_STATE_FREQ)
468 __naked void no_scalar_id_for_const(void)
471 "call %[bpf_ktime_get_ns];"
472 /* unpredictable jump */
473 "if r0 > 7 goto l0_%=;"
474 /* possibly generate same scalar ids for r3 and r4 */
481 /* possibly generate different scalar ids for r3 and r4 */
487 /* predictable jump, marks r3 and r4 precise */
488 "if r3 == r4 goto +0;"
492 : __imm(bpf_ktime_get_ns)
496 /* Same as no_scalar_id_for_const() but for 32-bit values */
498 __success __log_level(2)
499 __msg("11: (1e) if w3 == w4 goto pc+0")
500 __msg("frame 0: propagating r3,r4")
502 __msg("processed 15 insns")
503 __flag(BPF_F_TEST_STATE_FREQ)
504 __naked void no_scalar_id_for_const32(void)
507 "call %[bpf_ktime_get_ns];"
508 /* unpredictable jump */
509 "if r0 > 7 goto l0_%=;"
510 /* possibly generate same scalar ids for r3 and r4 */
517 /* possibly generate different scalar ids for r3 and r4 */
523 /* predictable jump, marks r1 and r2 precise */
524 "if w3 == w4 goto +0;"
528 : __imm(bpf_ktime_get_ns)
532 /* Check that unique scalar IDs are ignored when new verifier state is
533 * compared to cached verifier state. For this test:
534 * - cached state has no id on r1
535 * - new state has a unique id on r1
538 __success __log_level(2)
539 __msg("6: (25) if r6 > 0x7 goto pc+1")
540 __msg("7: (57) r1 &= 255")
541 __msg("8: (bf) r2 = r10")
542 __msg("from 6 to 8: safe")
543 __msg("processed 12 insns")
544 __flag(BPF_F_TEST_STATE_FREQ)
545 __naked void ignore_unique_scalar_ids_cur(void)
548 "call %[bpf_ktime_get_ns];"
550 "call %[bpf_ktime_get_ns];"
554 /* make r1.id unique */
556 "if r6 > 7 goto l0_%=;"
557 /* clear r1 id, but keep the range compatible */
560 /* get here in two states:
561 * - first: r1 has no id (cached state)
562 * - second: r1 has a unique id (should be considered equivalent)
568 : __imm(bpf_ktime_get_ns)
572 /* Check that unique scalar IDs are ignored when new verifier state is
573 * compared to cached verifier state. For this test:
574 * - cached state has a unique id on r1
575 * - new state has no id on r1
578 __success __log_level(2)
579 __msg("6: (25) if r6 > 0x7 goto pc+1")
580 __msg("7: (05) goto pc+1")
581 __msg("9: (bf) r2 = r10")
583 __msg("processed 13 insns")
584 __flag(BPF_F_TEST_STATE_FREQ)
585 __naked void ignore_unique_scalar_ids_old(void)
588 "call %[bpf_ktime_get_ns];"
590 "call %[bpf_ktime_get_ns];"
594 /* make r1.id unique */
596 "if r6 > 7 goto l1_%=;"
599 /* clear r1 id, but keep the range compatible */
602 /* get here in two states:
603 * - first: r1 has a unique id (cached state)
604 * - second: r1 has no id (should be considered equivalent)
610 : __imm(bpf_ktime_get_ns)
614 /* Check that two different scalar IDs in a verified state can't be
615 * mapped to the same scalar ID in current state.
618 __success __log_level(2)
619 /* The exit instruction should be reachable from two states,
620 * use two matches and "processed .. insns" to ensure this.
622 __msg("13: (95) exit")
623 __msg("13: (95) exit")
624 __msg("processed 18 insns")
625 __flag(BPF_F_TEST_STATE_FREQ)
626 __naked void two_old_ids_one_cur_id(void)
629 /* Give unique scalar IDs to r{6,7} */
630 "call %[bpf_ktime_get_ns];"
633 "call %[bpf_ktime_get_ns];"
637 /* Maybe make r{6,7} IDs identical */
638 "if r6 > r7 goto l0_%=;"
643 /* Mark r{6,7} precise.
644 * Get here in two states:
645 * - first: r6{.id=A}, r7{.id=B} (cached state)
646 * - second: r6{.id=A}, r7{.id=A}
647 * Currently we don't want to consider such states equivalent.
648 * Thus "exit;" would be verified twice.
655 : __imm(bpf_ktime_get_ns)
659 char _license[] SEC("license") = "GPL";