xref: /linux/tools/testing/selftests/bpf/prog_tests/reg_bounds.c (revision 71dfa617ea9f18e4585fe78364217cd32b1fc382)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
3 
4 #define _GNU_SOURCE
5 #include <limits.h>
6 #include <test_progs.h>
7 #include <linux/filter.h>
8 #include <linux/bpf.h>
9 
10 /* =================================
11  * SHORT AND CONSISTENT NUMBER TYPES
12  * =================================
13  */
14 #define U64_MAX ((u64)UINT64_MAX)
15 #define U32_MAX ((u32)UINT_MAX)
16 #define U16_MAX ((u32)UINT_MAX)
17 #define S64_MIN ((s64)INT64_MIN)
18 #define S64_MAX ((s64)INT64_MAX)
19 #define S32_MIN ((s32)INT_MIN)
20 #define S32_MAX ((s32)INT_MAX)
21 #define S16_MIN ((s16)0x80000000)
22 #define S16_MAX ((s16)0x7fffffff)
23 
24 typedef unsigned long long ___u64;
25 typedef unsigned int ___u32;
26 typedef long long ___s64;
27 typedef int ___s32;
28 
29 /* avoid conflicts with already defined types in kernel headers */
30 #define u64 ___u64
31 #define u32 ___u32
32 #define s64 ___s64
33 #define s32 ___s32
34 
35 /* ==================================
36  * STRING BUF ABSTRACTION AND HELPERS
37  * ==================================
38  */
39 struct strbuf {
40 	size_t buf_sz;
41 	int pos;
42 	char buf[0];
43 };
44 
45 #define DEFINE_STRBUF(name, N)						\
46 	struct { struct strbuf buf; char data[(N)]; } ___##name;	\
47 	struct strbuf *name = (___##name.buf.buf_sz = (N), ___##name.buf.pos = 0, &___##name.buf)
48 
49 __printf(2, 3)
50 static inline void snappendf(struct strbuf *s, const char *fmt, ...)
51 {
52 	va_list args;
53 
54 	va_start(args, fmt);
55 	s->pos += vsnprintf(s->buf + s->pos,
56 			    s->pos < s->buf_sz ? s->buf_sz - s->pos : 0,
57 			    fmt, args);
58 	va_end(args);
59 }
60 
61 /* ==================================
62  * GENERIC NUMBER TYPE AND OPERATIONS
63  * ==================================
64  */
65 enum num_t { U64, first_t = U64, U32, S64, S32, last_t = S32 };
66 
67 static __always_inline u64 min_t(enum num_t t, u64 x, u64 y)
68 {
69 	switch (t) {
70 	case U64: return (u64)x < (u64)y ? (u64)x : (u64)y;
71 	case U32: return (u32)x < (u32)y ? (u32)x : (u32)y;
72 	case S64: return (s64)x < (s64)y ? (s64)x : (s64)y;
73 	case S32: return (s32)x < (s32)y ? (s32)x : (s32)y;
74 	default: printf("min_t!\n"); exit(1);
75 	}
76 }
77 
78 static __always_inline u64 max_t(enum num_t t, u64 x, u64 y)
79 {
80 	switch (t) {
81 	case U64: return (u64)x > (u64)y ? (u64)x : (u64)y;
82 	case U32: return (u32)x > (u32)y ? (u32)x : (u32)y;
83 	case S64: return (s64)x > (s64)y ? (s64)x : (s64)y;
84 	case S32: return (s32)x > (s32)y ? (u32)(s32)x : (u32)(s32)y;
85 	default: printf("max_t!\n"); exit(1);
86 	}
87 }
88 
89 static __always_inline u64 cast_t(enum num_t t, u64 x)
90 {
91 	switch (t) {
92 	case U64: return (u64)x;
93 	case U32: return (u32)x;
94 	case S64: return (s64)x;
95 	case S32: return (u32)(s32)x;
96 	default: printf("cast_t!\n"); exit(1);
97 	}
98 }
99 
100 static const char *t_str(enum num_t t)
101 {
102 	switch (t) {
103 	case U64: return "u64";
104 	case U32: return "u32";
105 	case S64: return "s64";
106 	case S32: return "s32";
107 	default: printf("t_str!\n"); exit(1);
108 	}
109 }
110 
111 static enum num_t t_is_32(enum num_t t)
112 {
113 	switch (t) {
114 	case U64: return false;
115 	case U32: return true;
116 	case S64: return false;
117 	case S32: return true;
118 	default: printf("t_is_32!\n"); exit(1);
119 	}
120 }
121 
122 static enum num_t t_signed(enum num_t t)
123 {
124 	switch (t) {
125 	case U64: return S64;
126 	case U32: return S32;
127 	case S64: return S64;
128 	case S32: return S32;
129 	default: printf("t_signed!\n"); exit(1);
130 	}
131 }
132 
133 static enum num_t t_unsigned(enum num_t t)
134 {
135 	switch (t) {
136 	case U64: return U64;
137 	case U32: return U32;
138 	case S64: return U64;
139 	case S32: return U32;
140 	default: printf("t_unsigned!\n"); exit(1);
141 	}
142 }
143 
144 #define UNUM_MAX_DECIMAL U16_MAX
145 #define SNUM_MAX_DECIMAL S16_MAX
146 #define SNUM_MIN_DECIMAL S16_MIN
147 
148 static bool num_is_small(enum num_t t, u64 x)
149 {
150 	switch (t) {
151 	case U64: return (u64)x <= UNUM_MAX_DECIMAL;
152 	case U32: return (u32)x <= UNUM_MAX_DECIMAL;
153 	case S64: return (s64)x >= SNUM_MIN_DECIMAL && (s64)x <= SNUM_MAX_DECIMAL;
154 	case S32: return (s32)x >= SNUM_MIN_DECIMAL && (s32)x <= SNUM_MAX_DECIMAL;
155 	default: printf("num_is_small!\n"); exit(1);
156 	}
157 }
158 
159 static void snprintf_num(enum num_t t, struct strbuf *sb, u64 x)
160 {
161 	bool is_small = num_is_small(t, x);
162 
163 	if (is_small) {
164 		switch (t) {
165 		case U64: return snappendf(sb, "%llu", (u64)x);
166 		case U32: return snappendf(sb, "%u", (u32)x);
167 		case S64: return snappendf(sb, "%lld", (s64)x);
168 		case S32: return snappendf(sb, "%d", (s32)x);
169 		default: printf("snprintf_num!\n"); exit(1);
170 		}
171 	} else {
172 		switch (t) {
173 		case U64:
174 			if (x == U64_MAX)
175 				return snappendf(sb, "U64_MAX");
176 			else if (x >= U64_MAX - 256)
177 				return snappendf(sb, "U64_MAX-%llu", U64_MAX - x);
178 			else
179 				return snappendf(sb, "%#llx", (u64)x);
180 		case U32:
181 			if ((u32)x == U32_MAX)
182 				return snappendf(sb, "U32_MAX");
183 			else if ((u32)x >= U32_MAX - 256)
184 				return snappendf(sb, "U32_MAX-%u", U32_MAX - (u32)x);
185 			else
186 				return snappendf(sb, "%#x", (u32)x);
187 		case S64:
188 			if ((s64)x == S64_MAX)
189 				return snappendf(sb, "S64_MAX");
190 			else if ((s64)x >= S64_MAX - 256)
191 				return snappendf(sb, "S64_MAX-%lld", S64_MAX - (s64)x);
192 			else if ((s64)x == S64_MIN)
193 				return snappendf(sb, "S64_MIN");
194 			else if ((s64)x <= S64_MIN + 256)
195 				return snappendf(sb, "S64_MIN+%lld", (s64)x - S64_MIN);
196 			else
197 				return snappendf(sb, "%#llx", (s64)x);
198 		case S32:
199 			if ((s32)x == S32_MAX)
200 				return snappendf(sb, "S32_MAX");
201 			else if ((s32)x >= S32_MAX - 256)
202 				return snappendf(sb, "S32_MAX-%d", S32_MAX - (s32)x);
203 			else if ((s32)x == S32_MIN)
204 				return snappendf(sb, "S32_MIN");
205 			else if ((s32)x <= S32_MIN + 256)
206 				return snappendf(sb, "S32_MIN+%d", (s32)x - S32_MIN);
207 			else
208 				return snappendf(sb, "%#x", (s32)x);
209 		default: printf("snprintf_num!\n"); exit(1);
210 		}
211 	}
212 }
213 
214 /* ===================================
215  * GENERIC RANGE STRUCT AND OPERATIONS
216  * ===================================
217  */
218 struct range {
219 	u64 a, b;
220 };
221 
222 static void snprintf_range(enum num_t t, struct strbuf *sb, struct range x)
223 {
224 	if (x.a == x.b)
225 		return snprintf_num(t, sb, x.a);
226 
227 	snappendf(sb, "[");
228 	snprintf_num(t, sb, x.a);
229 	snappendf(sb, "; ");
230 	snprintf_num(t, sb, x.b);
231 	snappendf(sb, "]");
232 }
233 
234 static void print_range(enum num_t t, struct range x, const char *sfx)
235 {
236 	DEFINE_STRBUF(sb, 128);
237 
238 	snprintf_range(t, sb, x);
239 	printf("%s%s", sb->buf, sfx);
240 }
241 
242 static const struct range unkn[] = {
243 	[U64] = { 0, U64_MAX },
244 	[U32] = { 0, U32_MAX },
245 	[S64] = { (u64)S64_MIN, (u64)S64_MAX },
246 	[S32] = { (u64)(u32)S32_MIN, (u64)(u32)S32_MAX },
247 };
248 
249 static struct range unkn_subreg(enum num_t t)
250 {
251 	switch (t) {
252 	case U64: return unkn[U32];
253 	case U32: return unkn[U32];
254 	case S64: return unkn[U32];
255 	case S32: return unkn[S32];
256 	default: printf("unkn_subreg!\n"); exit(1);
257 	}
258 }
259 
260 static struct range range(enum num_t t, u64 a, u64 b)
261 {
262 	switch (t) {
263 	case U64: return (struct range){ (u64)a, (u64)b };
264 	case U32: return (struct range){ (u32)a, (u32)b };
265 	case S64: return (struct range){ (s64)a, (s64)b };
266 	case S32: return (struct range){ (u32)(s32)a, (u32)(s32)b };
267 	default: printf("range!\n"); exit(1);
268 	}
269 }
270 
271 static __always_inline u32 sign64(u64 x) { return (x >> 63) & 1; }
272 static __always_inline u32 sign32(u64 x) { return ((u32)x >> 31) & 1; }
273 static __always_inline u32 upper32(u64 x) { return (u32)(x >> 32); }
274 static __always_inline u64 swap_low32(u64 x, u32 y) { return (x & 0xffffffff00000000ULL) | y; }
275 
276 static bool range_eq(struct range x, struct range y)
277 {
278 	return x.a == y.a && x.b == y.b;
279 }
280 
281 static struct range range_cast_to_s32(struct range x)
282 {
283 	u64 a = x.a, b = x.b;
284 
285 	/* if upper 32 bits are constant, lower 32 bits should form a proper
286 	 * s32 range to be correct
287 	 */
288 	if (upper32(a) == upper32(b) && (s32)a <= (s32)b)
289 		return range(S32, a, b);
290 
291 	/* Special case where upper bits form a small sequence of two
292 	 * sequential numbers (in 32-bit unsigned space, so 0xffffffff to
293 	 * 0x00000000 is also valid), while lower bits form a proper s32 range
294 	 * going from negative numbers to positive numbers.
295 	 *
296 	 * E.g.: [0xfffffff0ffffff00; 0xfffffff100000010]. Iterating
297 	 * over full 64-bit numbers range will form a proper [-16, 16]
298 	 * ([0xffffff00; 0x00000010]) range in its lower 32 bits.
299 	 */
300 	if (upper32(a) + 1 == upper32(b) && (s32)a < 0 && (s32)b >= 0)
301 		return range(S32, a, b);
302 
303 	/* otherwise we can't derive much meaningful information */
304 	return unkn[S32];
305 }
306 
307 static struct range range_cast_u64(enum num_t to_t, struct range x)
308 {
309 	u64 a = (u64)x.a, b = (u64)x.b;
310 
311 	switch (to_t) {
312 	case U64:
313 		return x;
314 	case U32:
315 		if (upper32(a) != upper32(b))
316 			return unkn[U32];
317 		return range(U32, a, b);
318 	case S64:
319 		if (sign64(a) != sign64(b))
320 			return unkn[S64];
321 		return range(S64, a, b);
322 	case S32:
323 		return range_cast_to_s32(x);
324 	default: printf("range_cast_u64!\n"); exit(1);
325 	}
326 }
327 
328 static struct range range_cast_s64(enum num_t to_t, struct range x)
329 {
330 	s64 a = (s64)x.a, b = (s64)x.b;
331 
332 	switch (to_t) {
333 	case U64:
334 		/* equivalent to (s64)a <= (s64)b check */
335 		if (sign64(a) != sign64(b))
336 			return unkn[U64];
337 		return range(U64, a, b);
338 	case U32:
339 		if (upper32(a) != upper32(b) || sign32(a) != sign32(b))
340 			return unkn[U32];
341 		return range(U32, a, b);
342 	case S64:
343 		return x;
344 	case S32:
345 		return range_cast_to_s32(x);
346 	default: printf("range_cast_s64!\n"); exit(1);
347 	}
348 }
349 
350 static struct range range_cast_u32(enum num_t to_t, struct range x)
351 {
352 	u32 a = (u32)x.a, b = (u32)x.b;
353 
354 	switch (to_t) {
355 	case U64:
356 	case S64:
357 		/* u32 is always a valid zero-extended u64/s64 */
358 		return range(to_t, a, b);
359 	case U32:
360 		return x;
361 	case S32:
362 		return range_cast_to_s32(range(U32, a, b));
363 	default: printf("range_cast_u32!\n"); exit(1);
364 	}
365 }
366 
367 static struct range range_cast_s32(enum num_t to_t, struct range x)
368 {
369 	s32 a = (s32)x.a, b = (s32)x.b;
370 
371 	switch (to_t) {
372 	case U64:
373 	case U32:
374 	case S64:
375 		if (sign32(a) != sign32(b))
376 			return unkn[to_t];
377 		return range(to_t, a, b);
378 	case S32:
379 		return x;
380 	default: printf("range_cast_s32!\n"); exit(1);
381 	}
382 }
383 
384 /* Reinterpret range in *from_t* domain as a range in *to_t* domain preserving
385  * all possible information. Worst case, it will be unknown range within
386  * *to_t* domain, if nothing more specific can be guaranteed during the
387  * conversion
388  */
389 static struct range range_cast(enum num_t from_t, enum num_t to_t, struct range from)
390 {
391 	switch (from_t) {
392 	case U64: return range_cast_u64(to_t, from);
393 	case U32: return range_cast_u32(to_t, from);
394 	case S64: return range_cast_s64(to_t, from);
395 	case S32: return range_cast_s32(to_t, from);
396 	default: printf("range_cast!\n"); exit(1);
397 	}
398 }
399 
400 static bool is_valid_num(enum num_t t, u64 x)
401 {
402 	switch (t) {
403 	case U64: return true;
404 	case U32: return upper32(x) == 0;
405 	case S64: return true;
406 	case S32: return upper32(x) == 0;
407 	default: printf("is_valid_num!\n"); exit(1);
408 	}
409 }
410 
411 static bool is_valid_range(enum num_t t, struct range x)
412 {
413 	if (!is_valid_num(t, x.a) || !is_valid_num(t, x.b))
414 		return false;
415 
416 	switch (t) {
417 	case U64: return (u64)x.a <= (u64)x.b;
418 	case U32: return (u32)x.a <= (u32)x.b;
419 	case S64: return (s64)x.a <= (s64)x.b;
420 	case S32: return (s32)x.a <= (s32)x.b;
421 	default: printf("is_valid_range!\n"); exit(1);
422 	}
423 }
424 
425 static struct range range_improve(enum num_t t, struct range old, struct range new)
426 {
427 	return range(t, max_t(t, old.a, new.a), min_t(t, old.b, new.b));
428 }
429 
430 static struct range range_refine(enum num_t x_t, struct range x, enum num_t y_t, struct range y)
431 {
432 	struct range y_cast;
433 
434 	y_cast = range_cast(y_t, x_t, y);
435 
436 	/* the case when new range knowledge, *y*, is a 32-bit subregister
437 	 * range, while previous range knowledge, *x*, is a full register
438 	 * 64-bit range, needs special treatment to take into account upper 32
439 	 * bits of full register range
440 	 */
441 	if (t_is_32(y_t) && !t_is_32(x_t)) {
442 		struct range x_swap;
443 
444 		/* some combinations of upper 32 bits and sign bit can lead to
445 		 * invalid ranges, in such cases it's easier to detect them
446 		 * after cast/swap than try to enumerate all the conditions
447 		 * under which transformation and knowledge transfer is valid
448 		 */
449 		x_swap = range(x_t, swap_low32(x.a, y_cast.a), swap_low32(x.b, y_cast.b));
450 		if (!is_valid_range(x_t, x_swap))
451 			return x;
452 		return range_improve(x_t, x, x_swap);
453 	}
454 
455 	/* otherwise, plain range cast and intersection works */
456 	return range_improve(x_t, x, y_cast);
457 }
458 
459 /* =======================
460  * GENERIC CONDITIONAL OPS
461  * =======================
462  */
463 enum op { OP_LT, OP_LE, OP_GT, OP_GE, OP_EQ, OP_NE, first_op = OP_LT, last_op = OP_NE };
464 
465 static enum op complement_op(enum op op)
466 {
467 	switch (op) {
468 	case OP_LT: return OP_GE;
469 	case OP_LE: return OP_GT;
470 	case OP_GT: return OP_LE;
471 	case OP_GE: return OP_LT;
472 	case OP_EQ: return OP_NE;
473 	case OP_NE: return OP_EQ;
474 	default: printf("complement_op!\n"); exit(1);
475 	}
476 }
477 
478 static const char *op_str(enum op op)
479 {
480 	switch (op) {
481 	case OP_LT: return "<";
482 	case OP_LE: return "<=";
483 	case OP_GT: return ">";
484 	case OP_GE: return ">=";
485 	case OP_EQ: return "==";
486 	case OP_NE: return "!=";
487 	default: printf("op_str!\n"); exit(1);
488 	}
489 }
490 
491 /* Can register with range [x.a, x.b] *EVER* satisfy
492  * OP (<, <=, >, >=, ==, !=) relation to
493  * a regsiter with range [y.a, y.b]
494  * _in *num_t* domain_
495  */
496 static bool range_canbe_op(enum num_t t, struct range x, struct range y, enum op op)
497 {
498 #define range_canbe(T) do {									\
499 	switch (op) {										\
500 	case OP_LT: return (T)x.a < (T)y.b;							\
501 	case OP_LE: return (T)x.a <= (T)y.b;							\
502 	case OP_GT: return (T)x.b > (T)y.a;							\
503 	case OP_GE: return (T)x.b >= (T)y.a;							\
504 	case OP_EQ: return (T)max_t(t, x.a, y.a) <= (T)min_t(t, x.b, y.b);			\
505 	case OP_NE: return !((T)x.a == (T)x.b && (T)y.a == (T)y.b && (T)x.a == (T)y.a);		\
506 	default: printf("range_canbe op %d\n", op); exit(1);					\
507 	}											\
508 } while (0)
509 
510 	switch (t) {
511 	case U64: { range_canbe(u64); }
512 	case U32: { range_canbe(u32); }
513 	case S64: { range_canbe(s64); }
514 	case S32: { range_canbe(s32); }
515 	default: printf("range_canbe!\n"); exit(1);
516 	}
517 #undef range_canbe
518 }
519 
520 /* Does register with range [x.a, x.b] *ALWAYS* satisfy
521  * OP (<, <=, >, >=, ==, !=) relation to
522  * a regsiter with range [y.a, y.b]
523  * _in *num_t* domain_
524  */
525 static bool range_always_op(enum num_t t, struct range x, struct range y, enum op op)
526 {
527 	/* always op <=> ! canbe complement(op) */
528 	return !range_canbe_op(t, x, y, complement_op(op));
529 }
530 
531 /* Does register with range [x.a, x.b] *NEVER* satisfy
532  * OP (<, <=, >, >=, ==, !=) relation to
533  * a regsiter with range [y.a, y.b]
534  * _in *num_t* domain_
535  */
536 static bool range_never_op(enum num_t t, struct range x, struct range y, enum op op)
537 {
538 	return !range_canbe_op(t, x, y, op);
539 }
540 
541 /* similar to verifier's is_branch_taken():
542  *    1 - always taken;
543  *    0 - never taken,
544  *   -1 - unsure.
545  */
546 static int range_branch_taken_op(enum num_t t, struct range x, struct range y, enum op op)
547 {
548 	if (range_always_op(t, x, y, op))
549 		return 1;
550 	if (range_never_op(t, x, y, op))
551 		return 0;
552 	return -1;
553 }
554 
555 /* What would be the new estimates for register x and y ranges assuming truthful
556  * OP comparison between them. I.e., (x OP y == true) => x <- newx, y <- newy.
557  *
558  * We assume "interesting" cases where ranges overlap. Cases where it's
559  * obvious that (x OP y) is either always true or false should be filtered with
560  * range_never and range_always checks.
561  */
562 static void range_cond(enum num_t t, struct range x, struct range y,
563 		       enum op op, struct range *newx, struct range *newy)
564 {
565 	if (!range_canbe_op(t, x, y, op)) {
566 		/* nothing to adjust, can't happen, return original values */
567 		*newx = x;
568 		*newy = y;
569 		return;
570 	}
571 	switch (op) {
572 	case OP_LT:
573 		*newx = range(t, x.a, min_t(t, x.b, y.b - 1));
574 		*newy = range(t, max_t(t, x.a + 1, y.a), y.b);
575 		break;
576 	case OP_LE:
577 		*newx = range(t, x.a, min_t(t, x.b, y.b));
578 		*newy = range(t, max_t(t, x.a, y.a), y.b);
579 		break;
580 	case OP_GT:
581 		*newx = range(t, max_t(t, x.a, y.a + 1), x.b);
582 		*newy = range(t, y.a, min_t(t, x.b - 1, y.b));
583 		break;
584 	case OP_GE:
585 		*newx = range(t, max_t(t, x.a, y.a), x.b);
586 		*newy = range(t, y.a, min_t(t, x.b, y.b));
587 		break;
588 	case OP_EQ:
589 		*newx = range(t, max_t(t, x.a, y.a), min_t(t, x.b, y.b));
590 		*newy = range(t, max_t(t, x.a, y.a), min_t(t, x.b, y.b));
591 		break;
592 	case OP_NE:
593 		/* below logic is supported by the verifier now */
594 		if (x.a == x.b && x.a == y.a) {
595 			/* X is a constant matching left side of Y */
596 			*newx = range(t, x.a, x.b);
597 			*newy = range(t, y.a + 1, y.b);
598 		} else if (x.a == x.b && x.b == y.b) {
599 			/* X is a constant matching rigth side of Y */
600 			*newx = range(t, x.a, x.b);
601 			*newy = range(t, y.a, y.b - 1);
602 		} else if (y.a == y.b && x.a == y.a) {
603 			/* Y is a constant matching left side of X */
604 			*newx = range(t, x.a + 1, x.b);
605 			*newy = range(t, y.a, y.b);
606 		} else if (y.a == y.b && x.b == y.b) {
607 			/* Y is a constant matching rigth side of X */
608 			*newx = range(t, x.a, x.b - 1);
609 			*newy = range(t, y.a, y.b);
610 		} else {
611 			/* generic case, can't derive more information */
612 			*newx = range(t, x.a, x.b);
613 			*newy = range(t, y.a, y.b);
614 		}
615 
616 		break;
617 	default:
618 		break;
619 	}
620 }
621 
622 /* =======================
623  * REGISTER STATE HANDLING
624  * =======================
625  */
626 struct reg_state {
627 	struct range r[4]; /* indexed by enum num_t: U64, U32, S64, S32 */
628 	bool valid;
629 };
630 
631 static void print_reg_state(struct reg_state *r, const char *sfx)
632 {
633 	DEFINE_STRBUF(sb, 512);
634 	enum num_t t;
635 	int cnt = 0;
636 
637 	if (!r->valid) {
638 		printf("<not found>%s", sfx);
639 		return;
640 	}
641 
642 	snappendf(sb, "scalar(");
643 	for (t = first_t; t <= last_t; t++) {
644 		snappendf(sb, "%s%s=", cnt++ ? "," : "", t_str(t));
645 		snprintf_range(t, sb, r->r[t]);
646 	}
647 	snappendf(sb, ")");
648 
649 	printf("%s%s", sb->buf, sfx);
650 }
651 
652 static void print_refinement(enum num_t s_t, struct range src,
653 			     enum num_t d_t, struct range old, struct range new,
654 			     const char *ctx)
655 {
656 	printf("REFINING (%s) (%s)SRC=", ctx, t_str(s_t));
657 	print_range(s_t, src, "");
658 	printf(" (%s)DST_OLD=", t_str(d_t));
659 	print_range(d_t, old, "");
660 	printf(" (%s)DST_NEW=", t_str(d_t));
661 	print_range(d_t, new, "\n");
662 }
663 
664 static void reg_state_refine(struct reg_state *r, enum num_t t, struct range x, const char *ctx)
665 {
666 	enum num_t d_t, s_t;
667 	struct range old;
668 	bool keep_going = false;
669 
670 again:
671 	/* try to derive new knowledge from just learned range x of type t */
672 	for (d_t = first_t; d_t <= last_t; d_t++) {
673 		old = r->r[d_t];
674 		r->r[d_t] = range_refine(d_t, r->r[d_t], t, x);
675 		if (!range_eq(r->r[d_t], old)) {
676 			keep_going = true;
677 			if (env.verbosity >= VERBOSE_VERY)
678 				print_refinement(t, x, d_t, old, r->r[d_t], ctx);
679 		}
680 	}
681 
682 	/* now see if we can derive anything new from updated reg_state's ranges */
683 	for (s_t = first_t; s_t <= last_t; s_t++) {
684 		for (d_t = first_t; d_t <= last_t; d_t++) {
685 			old = r->r[d_t];
686 			r->r[d_t] = range_refine(d_t, r->r[d_t], s_t, r->r[s_t]);
687 			if (!range_eq(r->r[d_t], old)) {
688 				keep_going = true;
689 				if (env.verbosity >= VERBOSE_VERY)
690 					print_refinement(s_t, r->r[s_t], d_t, old, r->r[d_t], ctx);
691 			}
692 		}
693 	}
694 
695 	/* keep refining until we converge */
696 	if (keep_going) {
697 		keep_going = false;
698 		goto again;
699 	}
700 }
701 
702 static void reg_state_set_const(struct reg_state *rs, enum num_t t, u64 val)
703 {
704 	enum num_t tt;
705 
706 	rs->valid = true;
707 	for (tt = first_t; tt <= last_t; tt++)
708 		rs->r[tt] = tt == t ? range(t, val, val) : unkn[tt];
709 
710 	reg_state_refine(rs, t, rs->r[t], "CONST");
711 }
712 
713 static void reg_state_cond(enum num_t t, struct reg_state *x, struct reg_state *y, enum op op,
714 			   struct reg_state *newx, struct reg_state *newy, const char *ctx)
715 {
716 	char buf[32];
717 	enum num_t ts[2];
718 	struct reg_state xx = *x, yy = *y;
719 	int i, t_cnt;
720 	struct range z1, z2;
721 
722 	if (op == OP_EQ || op == OP_NE) {
723 		/* OP_EQ and OP_NE are sign-agnostic, so we need to process
724 		 * both signed and unsigned domains at the same time
725 		 */
726 		ts[0] = t_unsigned(t);
727 		ts[1] = t_signed(t);
728 		t_cnt = 2;
729 	} else {
730 		ts[0] = t;
731 		t_cnt = 1;
732 	}
733 
734 	for (i = 0; i < t_cnt; i++) {
735 		t = ts[i];
736 		z1 = x->r[t];
737 		z2 = y->r[t];
738 
739 		range_cond(t, z1, z2, op, &z1, &z2);
740 
741 		if (newx) {
742 			snprintf(buf, sizeof(buf), "%s R1", ctx);
743 			reg_state_refine(&xx, t, z1, buf);
744 		}
745 		if (newy) {
746 			snprintf(buf, sizeof(buf), "%s R2", ctx);
747 			reg_state_refine(&yy, t, z2, buf);
748 		}
749 	}
750 
751 	if (newx)
752 		*newx = xx;
753 	if (newy)
754 		*newy = yy;
755 }
756 
757 static int reg_state_branch_taken_op(enum num_t t, struct reg_state *x, struct reg_state *y,
758 				     enum op op)
759 {
760 	if (op == OP_EQ || op == OP_NE) {
761 		/* OP_EQ and OP_NE are sign-agnostic */
762 		enum num_t tu = t_unsigned(t);
763 		enum num_t ts = t_signed(t);
764 		int br_u, br_s, br;
765 
766 		br_u = range_branch_taken_op(tu, x->r[tu], y->r[tu], op);
767 		br_s = range_branch_taken_op(ts, x->r[ts], y->r[ts], op);
768 
769 		if (br_u >= 0 && br_s >= 0 && br_u != br_s)
770 			ASSERT_FALSE(true, "branch taken inconsistency!\n");
771 
772 		/* if 64-bit ranges are indecisive, use 32-bit subranges to
773 		 * eliminate always/never taken branches, if possible
774 		 */
775 		if (br_u == -1 && (t == U64 || t == S64)) {
776 			br = range_branch_taken_op(U32, x->r[U32], y->r[U32], op);
777 			/* we can only reject for OP_EQ, never take branch
778 			 * based on lower 32 bits
779 			 */
780 			if (op == OP_EQ && br == 0)
781 				return 0;
782 			/* for OP_NEQ we can be conclusive only if lower 32 bits
783 			 * differ and thus inequality branch is always taken
784 			 */
785 			if (op == OP_NE && br == 1)
786 				return 1;
787 
788 			br = range_branch_taken_op(S32, x->r[S32], y->r[S32], op);
789 			if (op == OP_EQ && br == 0)
790 				return 0;
791 			if (op == OP_NE && br == 1)
792 				return 1;
793 		}
794 
795 		return br_u >= 0 ? br_u : br_s;
796 	}
797 	return range_branch_taken_op(t, x->r[t], y->r[t], op);
798 }
799 
800 /* =====================================
801  * BPF PROGS GENERATION AND VERIFICATION
802  * =====================================
803  */
804 struct case_spec {
805 	/* whether to init full register (r1) or sub-register (w1) */
806 	bool init_subregs;
807 	/* whether to establish initial value range on full register (r1) or
808 	 * sub-register (w1)
809 	 */
810 	bool setup_subregs;
811 	/* whether to establish initial value range using signed or unsigned
812 	 * comparisons (i.e., initialize umin/umax or smin/smax directly)
813 	 */
814 	bool setup_signed;
815 	/* whether to perform comparison on full registers or sub-registers */
816 	bool compare_subregs;
817 	/* whether to perform comparison using signed or unsigned operations */
818 	bool compare_signed;
819 };
820 
821 /* Generate test BPF program based on provided test ranges, operation, and
822  * specifications about register bitness and signedness.
823  */
824 static int load_range_cmp_prog(struct range x, struct range y, enum op op,
825 			       int branch_taken, struct case_spec spec,
826 			       char *log_buf, size_t log_sz,
827 			       int *false_pos, int *true_pos)
828 {
829 #define emit(insn) ({							\
830 	struct bpf_insn __insns[] = { insn };				\
831 	int __i;							\
832 	for (__i = 0; __i < ARRAY_SIZE(__insns); __i++)			\
833 		insns[cur_pos + __i] = __insns[__i];			\
834 	cur_pos += __i;							\
835 })
836 #define JMP_TO(target) (target - cur_pos - 1)
837 	int cur_pos = 0, exit_pos, fd, op_code;
838 	struct bpf_insn insns[64];
839 	LIBBPF_OPTS(bpf_prog_load_opts, opts,
840 		.log_level = 2,
841 		.log_buf = log_buf,
842 		.log_size = log_sz,
843 		.prog_flags = testing_prog_flags(),
844 	);
845 
846 	/* ; skip exit block below
847 	 * goto +2;
848 	 */
849 	emit(BPF_JMP_A(2));
850 	exit_pos = cur_pos;
851 	/* ; exit block for all the preparatory conditionals
852 	 * out:
853 	 * r0 = 0;
854 	 * exit;
855 	 */
856 	emit(BPF_MOV64_IMM(BPF_REG_0, 0));
857 	emit(BPF_EXIT_INSN());
858 	/*
859 	 * ; assign r6/w6 and r7/w7 unpredictable u64/u32 value
860 	 * call bpf_get_current_pid_tgid;
861 	 * r6 = r0;               | w6 = w0;
862 	 * call bpf_get_current_pid_tgid;
863 	 * r7 = r0;               | w7 = w0;
864 	 */
865 	emit(BPF_EMIT_CALL(BPF_FUNC_get_current_pid_tgid));
866 	if (spec.init_subregs)
867 		emit(BPF_MOV32_REG(BPF_REG_6, BPF_REG_0));
868 	else
869 		emit(BPF_MOV64_REG(BPF_REG_6, BPF_REG_0));
870 	emit(BPF_EMIT_CALL(BPF_FUNC_get_current_pid_tgid));
871 	if (spec.init_subregs)
872 		emit(BPF_MOV32_REG(BPF_REG_7, BPF_REG_0));
873 	else
874 		emit(BPF_MOV64_REG(BPF_REG_7, BPF_REG_0));
875 	/* ; setup initial r6/w6 possible value range ([x.a, x.b])
876 	 * r1 = %[x.a] ll;        | w1 = %[x.a];
877 	 * r2 = %[x.b] ll;        | w2 = %[x.b];
878 	 * if r6 < r1 goto out;   | if w6 < w1 goto out;
879 	 * if r6 > r2 goto out;   | if w6 > w2 goto out;
880 	 */
881 	if (spec.setup_subregs) {
882 		emit(BPF_MOV32_IMM(BPF_REG_1, (s32)x.a));
883 		emit(BPF_MOV32_IMM(BPF_REG_2, (s32)x.b));
884 		emit(BPF_JMP32_REG(spec.setup_signed ? BPF_JSLT : BPF_JLT,
885 				   BPF_REG_6, BPF_REG_1, JMP_TO(exit_pos)));
886 		emit(BPF_JMP32_REG(spec.setup_signed ? BPF_JSGT : BPF_JGT,
887 				   BPF_REG_6, BPF_REG_2, JMP_TO(exit_pos)));
888 	} else {
889 		emit(BPF_LD_IMM64(BPF_REG_1, x.a));
890 		emit(BPF_LD_IMM64(BPF_REG_2, x.b));
891 		emit(BPF_JMP_REG(spec.setup_signed ? BPF_JSLT : BPF_JLT,
892 				 BPF_REG_6, BPF_REG_1, JMP_TO(exit_pos)));
893 		emit(BPF_JMP_REG(spec.setup_signed ? BPF_JSGT : BPF_JGT,
894 				 BPF_REG_6, BPF_REG_2, JMP_TO(exit_pos)));
895 	}
896 	/* ; setup initial r7/w7 possible value range ([y.a, y.b])
897 	 * r1 = %[y.a] ll;        | w1 = %[y.a];
898 	 * r2 = %[y.b] ll;        | w2 = %[y.b];
899 	 * if r7 < r1 goto out;   | if w7 < w1 goto out;
900 	 * if r7 > r2 goto out;   | if w7 > w2 goto out;
901 	 */
902 	if (spec.setup_subregs) {
903 		emit(BPF_MOV32_IMM(BPF_REG_1, (s32)y.a));
904 		emit(BPF_MOV32_IMM(BPF_REG_2, (s32)y.b));
905 		emit(BPF_JMP32_REG(spec.setup_signed ? BPF_JSLT : BPF_JLT,
906 				   BPF_REG_7, BPF_REG_1, JMP_TO(exit_pos)));
907 		emit(BPF_JMP32_REG(spec.setup_signed ? BPF_JSGT : BPF_JGT,
908 				   BPF_REG_7, BPF_REG_2, JMP_TO(exit_pos)));
909 	} else {
910 		emit(BPF_LD_IMM64(BPF_REG_1, y.a));
911 		emit(BPF_LD_IMM64(BPF_REG_2, y.b));
912 		emit(BPF_JMP_REG(spec.setup_signed ? BPF_JSLT : BPF_JLT,
913 				 BPF_REG_7, BPF_REG_1, JMP_TO(exit_pos)));
914 		emit(BPF_JMP_REG(spec.setup_signed ? BPF_JSGT : BPF_JGT,
915 				 BPF_REG_7, BPF_REG_2, JMP_TO(exit_pos)));
916 	}
917 	/* ; range test instruction
918 	 * if r6 <op> r7 goto +3; | if w6 <op> w7 goto +3;
919 	 */
920 	switch (op) {
921 	case OP_LT: op_code = spec.compare_signed ? BPF_JSLT : BPF_JLT; break;
922 	case OP_LE: op_code = spec.compare_signed ? BPF_JSLE : BPF_JLE; break;
923 	case OP_GT: op_code = spec.compare_signed ? BPF_JSGT : BPF_JGT; break;
924 	case OP_GE: op_code = spec.compare_signed ? BPF_JSGE : BPF_JGE; break;
925 	case OP_EQ: op_code = BPF_JEQ; break;
926 	case OP_NE: op_code = BPF_JNE; break;
927 	default:
928 		printf("unrecognized op %d\n", op);
929 		return -ENOTSUP;
930 	}
931 	/* ; BEFORE conditional, r0/w0 = {r6/w6,r7/w7} is to extract verifier state reliably
932 	 * ; this is used for debugging, as verifier doesn't always print
933 	 * ; registers states as of condition jump instruction (e.g., when
934 	 * ; precision marking happens)
935 	 * r0 = r6;               | w0 = w6;
936 	 * r0 = r7;               | w0 = w7;
937 	 */
938 	if (spec.compare_subregs) {
939 		emit(BPF_MOV32_REG(BPF_REG_0, BPF_REG_6));
940 		emit(BPF_MOV32_REG(BPF_REG_0, BPF_REG_7));
941 	} else {
942 		emit(BPF_MOV64_REG(BPF_REG_0, BPF_REG_6));
943 		emit(BPF_MOV64_REG(BPF_REG_0, BPF_REG_7));
944 	}
945 	if (spec.compare_subregs)
946 		emit(BPF_JMP32_REG(op_code, BPF_REG_6, BPF_REG_7, 3));
947 	else
948 		emit(BPF_JMP_REG(op_code, BPF_REG_6, BPF_REG_7, 3));
949 	/* ; FALSE branch, r0/w0 = {r6/w6,r7/w7} is to extract verifier state reliably
950 	 * r0 = r6;               | w0 = w6;
951 	 * r0 = r7;               | w0 = w7;
952 	 * exit;
953 	 */
954 	*false_pos = cur_pos;
955 	if (spec.compare_subregs) {
956 		emit(BPF_MOV32_REG(BPF_REG_0, BPF_REG_6));
957 		emit(BPF_MOV32_REG(BPF_REG_0, BPF_REG_7));
958 	} else {
959 		emit(BPF_MOV64_REG(BPF_REG_0, BPF_REG_6));
960 		emit(BPF_MOV64_REG(BPF_REG_0, BPF_REG_7));
961 	}
962 	if (branch_taken == 1) /* false branch is never taken */
963 		emit(BPF_EMIT_CALL(0xDEAD)); /* poison this branch */
964 	else
965 		emit(BPF_EXIT_INSN());
966 	/* ; TRUE branch, r0/w0 = {r6/w6,r7/w7} is to extract verifier state reliably
967 	 * r0 = r6;               | w0 = w6;
968 	 * r0 = r7;               | w0 = w7;
969 	 * exit;
970 	 */
971 	*true_pos = cur_pos;
972 	if (spec.compare_subregs) {
973 		emit(BPF_MOV32_REG(BPF_REG_0, BPF_REG_6));
974 		emit(BPF_MOV32_REG(BPF_REG_0, BPF_REG_7));
975 	} else {
976 		emit(BPF_MOV64_REG(BPF_REG_0, BPF_REG_6));
977 		emit(BPF_MOV64_REG(BPF_REG_0, BPF_REG_7));
978 	}
979 	if (branch_taken == 0) /* true branch is never taken */
980 		emit(BPF_EMIT_CALL(0xDEAD)); /* poison this branch */
981 	emit(BPF_EXIT_INSN()); /* last instruction has to be exit */
982 
983 	fd = bpf_prog_load(BPF_PROG_TYPE_RAW_TRACEPOINT, "reg_bounds_test",
984 			   "GPL", insns, cur_pos, &opts);
985 	if (fd < 0)
986 		return fd;
987 
988 	close(fd);
989 	return 0;
990 #undef emit
991 #undef JMP_TO
992 }
993 
994 #define str_has_pfx(str, pfx) (strncmp(str, pfx, strlen(pfx)) == 0)
995 
996 /* Parse register state from verifier log.
997  * `s` should point to the start of "Rx = ..." substring in the verifier log.
998  */
999 static int parse_reg_state(const char *s, struct reg_state *reg)
1000 {
1001 	/* There are two generic forms for SCALAR register:
1002 	 * - known constant: R6_rwD=P%lld
1003 	 * - range: R6_rwD=scalar(id=1,...), where "..." is a comma-separated
1004 	 *   list of optional range specifiers:
1005 	 *     - umin=%llu, if missing, assumed 0;
1006 	 *     - umax=%llu, if missing, assumed U64_MAX;
1007 	 *     - smin=%lld, if missing, assumed S64_MIN;
1008 	 *     - smax=%lld, if missing, assummed S64_MAX;
1009 	 *     - umin32=%d, if missing, assumed 0;
1010 	 *     - umax32=%d, if missing, assumed U32_MAX;
1011 	 *     - smin32=%d, if missing, assumed S32_MIN;
1012 	 *     - smax32=%d, if missing, assummed S32_MAX;
1013 	 *     - var_off=(%#llx; %#llx), tnum part, we don't care about it.
1014 	 *
1015 	 * If some of the values are equal, they will be grouped (but min/max
1016 	 * are not mixed together, and similarly negative values are not
1017 	 * grouped with non-negative ones). E.g.:
1018 	 *
1019 	 *   R6_w=Pscalar(smin=smin32=0, smax=umax=umax32=1000)
1020 	 *
1021 	 * _rwD part is optional (and any of the letters can be missing).
1022 	 * P (precision mark) is optional as well.
1023 	 *
1024 	 * Anything inside scalar() is optional, including id, of course.
1025 	 */
1026 	struct {
1027 		const char *pfx;
1028 		u64 *dst, def;
1029 		bool is_32, is_set;
1030 	} *f, fields[8] = {
1031 		{"smin=", &reg->r[S64].a, S64_MIN},
1032 		{"smax=", &reg->r[S64].b, S64_MAX},
1033 		{"umin=", &reg->r[U64].a, 0},
1034 		{"umax=", &reg->r[U64].b, U64_MAX},
1035 		{"smin32=", &reg->r[S32].a, (u32)S32_MIN, true},
1036 		{"smax32=", &reg->r[S32].b, (u32)S32_MAX, true},
1037 		{"umin32=", &reg->r[U32].a, 0,            true},
1038 		{"umax32=", &reg->r[U32].b, U32_MAX,      true},
1039 	};
1040 	const char *p;
1041 	int i;
1042 
1043 	p = strchr(s, '=');
1044 	if (!p)
1045 		return -EINVAL;
1046 	p++;
1047 	if (*p == 'P')
1048 		p++;
1049 
1050 	if (!str_has_pfx(p, "scalar(")) {
1051 		long long sval;
1052 		enum num_t t;
1053 
1054 		if (p[0] == '0' && p[1] == 'x') {
1055 			if (sscanf(p, "%llx", &sval) != 1)
1056 				return -EINVAL;
1057 		} else {
1058 			if (sscanf(p, "%lld", &sval) != 1)
1059 				return -EINVAL;
1060 		}
1061 
1062 		reg->valid = true;
1063 		for (t = first_t; t <= last_t; t++) {
1064 			reg->r[t] = range(t, sval, sval);
1065 		}
1066 		return 0;
1067 	}
1068 
1069 	p += sizeof("scalar");
1070 	while (p) {
1071 		int midxs[ARRAY_SIZE(fields)], mcnt = 0;
1072 		u64 val;
1073 
1074 		for (i = 0; i < ARRAY_SIZE(fields); i++) {
1075 			f = &fields[i];
1076 			if (!str_has_pfx(p, f->pfx))
1077 				continue;
1078 			midxs[mcnt++] = i;
1079 			p += strlen(f->pfx);
1080 		}
1081 
1082 		if (mcnt) {
1083 			/* populate all matched fields */
1084 			if (p[0] == '0' && p[1] == 'x') {
1085 				if (sscanf(p, "%llx", &val) != 1)
1086 					return -EINVAL;
1087 			} else {
1088 				if (sscanf(p, "%lld", &val) != 1)
1089 					return -EINVAL;
1090 			}
1091 
1092 			for (i = 0; i < mcnt; i++) {
1093 				f = &fields[midxs[i]];
1094 				f->is_set = true;
1095 				*f->dst = f->is_32 ? (u64)(u32)val : val;
1096 			}
1097 		} else if (str_has_pfx(p, "var_off")) {
1098 			/* skip "var_off=(0x0; 0x3f)" part completely */
1099 			p = strchr(p, ')');
1100 			if (!p)
1101 				return -EINVAL;
1102 			p++;
1103 		}
1104 
1105 		p = strpbrk(p, ",)");
1106 		if (*p == ')')
1107 			break;
1108 		if (p)
1109 			p++;
1110 	}
1111 
1112 	reg->valid = true;
1113 
1114 	for (i = 0; i < ARRAY_SIZE(fields); i++) {
1115 		f = &fields[i];
1116 		if (!f->is_set)
1117 			*f->dst = f->def;
1118 	}
1119 
1120 	return 0;
1121 }
1122 
1123 
1124 /* Parse all register states (TRUE/FALSE branches and DST/SRC registers)
1125  * out of the verifier log for a corresponding test case BPF program.
1126  */
1127 static int parse_range_cmp_log(const char *log_buf, struct case_spec spec,
1128 			       int false_pos, int true_pos,
1129 			       struct reg_state *false1_reg, struct reg_state *false2_reg,
1130 			       struct reg_state *true1_reg, struct reg_state *true2_reg)
1131 {
1132 	struct {
1133 		int insn_idx;
1134 		int reg_idx;
1135 		const char *reg_upper;
1136 		struct reg_state *state;
1137 	} specs[] = {
1138 		{false_pos,     6, "R6=", false1_reg},
1139 		{false_pos + 1, 7, "R7=", false2_reg},
1140 		{true_pos,      6, "R6=", true1_reg},
1141 		{true_pos + 1,  7, "R7=", true2_reg},
1142 	};
1143 	char buf[32];
1144 	const char *p = log_buf, *q;
1145 	int i, err;
1146 
1147 	for (i = 0; i < 4; i++) {
1148 		sprintf(buf, "%d: (%s) %s = %s%d", specs[i].insn_idx,
1149 			spec.compare_subregs ? "bc" : "bf",
1150 			spec.compare_subregs ? "w0" : "r0",
1151 			spec.compare_subregs ? "w" : "r", specs[i].reg_idx);
1152 
1153 		q = strstr(p, buf);
1154 		if (!q) {
1155 			*specs[i].state = (struct reg_state){.valid = false};
1156 			continue;
1157 		}
1158 		p = strstr(q, specs[i].reg_upper);
1159 		if (!p)
1160 			return -EINVAL;
1161 		err = parse_reg_state(p, specs[i].state);
1162 		if (err)
1163 			return -EINVAL;
1164 	}
1165 	return 0;
1166 }
1167 
1168 /* Validate ranges match, and print details if they don't */
1169 static bool assert_range_eq(enum num_t t, struct range x, struct range y,
1170 			    const char *ctx1, const char *ctx2)
1171 {
1172 	DEFINE_STRBUF(sb, 512);
1173 
1174 	if (range_eq(x, y))
1175 		return true;
1176 
1177 	snappendf(sb, "MISMATCH %s.%s: ", ctx1, ctx2);
1178 	snprintf_range(t, sb, x);
1179 	snappendf(sb, " != ");
1180 	snprintf_range(t, sb, y);
1181 
1182 	printf("%s\n", sb->buf);
1183 
1184 	return false;
1185 }
1186 
1187 /* Validate that register states match, and print details if they don't */
1188 static bool assert_reg_state_eq(struct reg_state *r, struct reg_state *e, const char *ctx)
1189 {
1190 	bool ok = true;
1191 	enum num_t t;
1192 
1193 	if (r->valid != e->valid) {
1194 		printf("MISMATCH %s: actual %s != expected %s\n", ctx,
1195 		       r->valid ? "<valid>" : "<invalid>",
1196 		       e->valid ? "<valid>" : "<invalid>");
1197 		return false;
1198 	}
1199 
1200 	if (!r->valid)
1201 		return true;
1202 
1203 	for (t = first_t; t <= last_t; t++) {
1204 		if (!assert_range_eq(t, r->r[t], e->r[t], ctx, t_str(t)))
1205 			ok = false;
1206 	}
1207 
1208 	return ok;
1209 }
1210 
1211 /* Printf verifier log, filtering out irrelevant noise */
1212 static void print_verifier_log(const char *buf)
1213 {
1214 	const char *p;
1215 
1216 	while (buf[0]) {
1217 		p = strchrnul(buf, '\n');
1218 
1219 		/* filter out irrelevant precision backtracking logs */
1220 		if (str_has_pfx(buf, "mark_precise: "))
1221 			goto skip_line;
1222 
1223 		printf("%.*s\n", (int)(p - buf), buf);
1224 
1225 skip_line:
1226 		buf = *p == '\0' ? p : p + 1;
1227 	}
1228 }
1229 
1230 /* Simulate provided test case purely with our own range-based logic.
1231  * This is done to set up expectations for verifier's branch_taken logic and
1232  * verifier's register states in the verifier log.
1233  */
1234 static void sim_case(enum num_t init_t, enum num_t cond_t,
1235 		     struct range x, struct range y, enum op op,
1236 		     struct reg_state *fr1, struct reg_state *fr2,
1237 		     struct reg_state *tr1, struct reg_state *tr2,
1238 		     int *branch_taken)
1239 {
1240 	const u64 A = x.a;
1241 	const u64 B = x.b;
1242 	const u64 C = y.a;
1243 	const u64 D = y.b;
1244 	struct reg_state rc;
1245 	enum op rev_op = complement_op(op);
1246 	enum num_t t;
1247 
1248 	fr1->valid = fr2->valid = true;
1249 	tr1->valid = tr2->valid = true;
1250 	for (t = first_t; t <= last_t; t++) {
1251 		/* if we are initializing using 32-bit subregisters,
1252 		 * full registers get upper 32 bits zeroed automatically
1253 		 */
1254 		struct range z = t_is_32(init_t) ? unkn_subreg(t) : unkn[t];
1255 
1256 		fr1->r[t] = fr2->r[t] = tr1->r[t] = tr2->r[t] = z;
1257 	}
1258 
1259 	/* step 1: r1 >= A, r2 >= C */
1260 	reg_state_set_const(&rc, init_t, A);
1261 	reg_state_cond(init_t, fr1, &rc, OP_GE, fr1, NULL, "r1>=A");
1262 	reg_state_set_const(&rc, init_t, C);
1263 	reg_state_cond(init_t, fr2, &rc, OP_GE, fr2, NULL, "r2>=C");
1264 	*tr1 = *fr1;
1265 	*tr2 = *fr2;
1266 	if (env.verbosity >= VERBOSE_VERY) {
1267 		printf("STEP1 (%s) R1: ", t_str(init_t)); print_reg_state(fr1, "\n");
1268 		printf("STEP1 (%s) R2: ", t_str(init_t)); print_reg_state(fr2, "\n");
1269 	}
1270 
1271 	/* step 2: r1 <= B, r2 <= D */
1272 	reg_state_set_const(&rc, init_t, B);
1273 	reg_state_cond(init_t, fr1, &rc, OP_LE, fr1, NULL, "r1<=B");
1274 	reg_state_set_const(&rc, init_t, D);
1275 	reg_state_cond(init_t, fr2, &rc, OP_LE, fr2, NULL, "r2<=D");
1276 	*tr1 = *fr1;
1277 	*tr2 = *fr2;
1278 	if (env.verbosity >= VERBOSE_VERY) {
1279 		printf("STEP2 (%s) R1: ", t_str(init_t)); print_reg_state(fr1, "\n");
1280 		printf("STEP2 (%s) R2: ", t_str(init_t)); print_reg_state(fr2, "\n");
1281 	}
1282 
1283 	/* step 3: r1 <op> r2 */
1284 	*branch_taken = reg_state_branch_taken_op(cond_t, fr1, fr2, op);
1285 	fr1->valid = fr2->valid = false;
1286 	tr1->valid = tr2->valid = false;
1287 	if (*branch_taken != 1) { /* FALSE is possible */
1288 		fr1->valid = fr2->valid = true;
1289 		reg_state_cond(cond_t, fr1, fr2, rev_op, fr1, fr2, "FALSE");
1290 	}
1291 	if (*branch_taken != 0) { /* TRUE is possible */
1292 		tr1->valid = tr2->valid = true;
1293 		reg_state_cond(cond_t, tr1, tr2, op, tr1, tr2, "TRUE");
1294 	}
1295 	if (env.verbosity >= VERBOSE_VERY) {
1296 		printf("STEP3 (%s) FALSE R1:", t_str(cond_t)); print_reg_state(fr1, "\n");
1297 		printf("STEP3 (%s) FALSE R2:", t_str(cond_t)); print_reg_state(fr2, "\n");
1298 		printf("STEP3 (%s) TRUE  R1:", t_str(cond_t)); print_reg_state(tr1, "\n");
1299 		printf("STEP3 (%s) TRUE  R2:", t_str(cond_t)); print_reg_state(tr2, "\n");
1300 	}
1301 }
1302 
1303 /* ===============================
1304  * HIGH-LEVEL TEST CASE VALIDATION
1305  * ===============================
1306  */
1307 static u32 upper_seeds[] = {
1308 	0,
1309 	1,
1310 	U32_MAX,
1311 	U32_MAX - 1,
1312 	S32_MAX,
1313 	(u32)S32_MIN,
1314 };
1315 
1316 static u32 lower_seeds[] = {
1317 	0,
1318 	1,
1319 	2, (u32)-2,
1320 	255, (u32)-255,
1321 	UINT_MAX,
1322 	UINT_MAX - 1,
1323 	INT_MAX,
1324 	(u32)INT_MIN,
1325 };
1326 
1327 struct ctx {
1328 	int val_cnt, subval_cnt, range_cnt, subrange_cnt;
1329 	u64 uvals[ARRAY_SIZE(upper_seeds) * ARRAY_SIZE(lower_seeds)];
1330 	s64 svals[ARRAY_SIZE(upper_seeds) * ARRAY_SIZE(lower_seeds)];
1331 	u32 usubvals[ARRAY_SIZE(lower_seeds)];
1332 	s32 ssubvals[ARRAY_SIZE(lower_seeds)];
1333 	struct range *uranges, *sranges;
1334 	struct range *usubranges, *ssubranges;
1335 	int max_failure_cnt, cur_failure_cnt;
1336 	int total_case_cnt, case_cnt;
1337 	int rand_case_cnt;
1338 	unsigned rand_seed;
1339 	__u64 start_ns;
1340 	char progress_ctx[64];
1341 };
1342 
1343 static void cleanup_ctx(struct ctx *ctx)
1344 {
1345 	free(ctx->uranges);
1346 	free(ctx->sranges);
1347 	free(ctx->usubranges);
1348 	free(ctx->ssubranges);
1349 }
1350 
1351 struct subtest_case {
1352 	enum num_t init_t;
1353 	enum num_t cond_t;
1354 	struct range x;
1355 	struct range y;
1356 	enum op op;
1357 };
1358 
1359 static void subtest_case_str(struct strbuf *sb, struct subtest_case *t, bool use_op)
1360 {
1361 	snappendf(sb, "(%s)", t_str(t->init_t));
1362 	snprintf_range(t->init_t, sb, t->x);
1363 	snappendf(sb, " (%s)%s ", t_str(t->cond_t), use_op ? op_str(t->op) : "<op>");
1364 	snprintf_range(t->init_t, sb, t->y);
1365 }
1366 
1367 /* Generate and validate test case based on specific combination of setup
1368  * register ranges (including their expected num_t domain), and conditional
1369  * operation to perform (including num_t domain in which it has to be
1370  * performed)
1371  */
1372 static int verify_case_op(enum num_t init_t, enum num_t cond_t,
1373 			  struct range x, struct range y, enum op op)
1374 {
1375 	char log_buf[256 * 1024];
1376 	size_t log_sz = sizeof(log_buf);
1377 	int err, false_pos = 0, true_pos = 0, branch_taken;
1378 	struct reg_state fr1, fr2, tr1, tr2;
1379 	struct reg_state fe1, fe2, te1, te2;
1380 	bool failed = false;
1381 	struct case_spec spec = {
1382 		.init_subregs = (init_t == U32 || init_t == S32),
1383 		.setup_subregs = (init_t == U32 || init_t == S32),
1384 		.setup_signed = (init_t == S64 || init_t == S32),
1385 		.compare_subregs = (cond_t == U32 || cond_t == S32),
1386 		.compare_signed = (cond_t == S64 || cond_t == S32),
1387 	};
1388 
1389 	log_buf[0] = '\0';
1390 
1391 	sim_case(init_t, cond_t, x, y, op, &fe1, &fe2, &te1, &te2, &branch_taken);
1392 
1393 	err = load_range_cmp_prog(x, y, op, branch_taken, spec,
1394 				  log_buf, log_sz, &false_pos, &true_pos);
1395 	if (err) {
1396 		ASSERT_OK(err, "load_range_cmp_prog");
1397 		failed = true;
1398 	}
1399 
1400 	err = parse_range_cmp_log(log_buf, spec, false_pos, true_pos,
1401 				  &fr1, &fr2, &tr1, &tr2);
1402 	if (err) {
1403 		ASSERT_OK(err, "parse_range_cmp_log");
1404 		failed = true;
1405 	}
1406 
1407 	if (!assert_reg_state_eq(&fr1, &fe1, "false_reg1") ||
1408 	    !assert_reg_state_eq(&fr2, &fe2, "false_reg2") ||
1409 	    !assert_reg_state_eq(&tr1, &te1, "true_reg1") ||
1410 	    !assert_reg_state_eq(&tr2, &te2, "true_reg2")) {
1411 		failed = true;
1412 	}
1413 
1414 	if (failed || env.verbosity >= VERBOSE_NORMAL) {
1415 		if (failed || env.verbosity >= VERBOSE_VERY) {
1416 			printf("VERIFIER LOG:\n========================\n");
1417 			print_verifier_log(log_buf);
1418 			printf("=====================\n");
1419 		}
1420 		printf("ACTUAL   FALSE1: "); print_reg_state(&fr1, "\n");
1421 		printf("EXPECTED FALSE1: "); print_reg_state(&fe1, "\n");
1422 		printf("ACTUAL   FALSE2: "); print_reg_state(&fr2, "\n");
1423 		printf("EXPECTED FALSE2: "); print_reg_state(&fe2, "\n");
1424 		printf("ACTUAL   TRUE1:  "); print_reg_state(&tr1, "\n");
1425 		printf("EXPECTED TRUE1:  "); print_reg_state(&te1, "\n");
1426 		printf("ACTUAL   TRUE2:  "); print_reg_state(&tr2, "\n");
1427 		printf("EXPECTED TRUE2:  "); print_reg_state(&te2, "\n");
1428 
1429 		return failed ? -EINVAL : 0;
1430 	}
1431 
1432 	return 0;
1433 }
1434 
1435 /* Given setup ranges and number types, go over all supported operations,
1436  * generating individual subtest for each allowed combination
1437  */
1438 static int verify_case_opt(struct ctx *ctx, enum num_t init_t, enum num_t cond_t,
1439 			   struct range x, struct range y, bool is_subtest)
1440 {
1441 	DEFINE_STRBUF(sb, 256);
1442 	int err;
1443 	struct subtest_case sub = {
1444 		.init_t = init_t,
1445 		.cond_t = cond_t,
1446 		.x = x,
1447 		.y = y,
1448 	};
1449 
1450 	sb->pos = 0; /* reset position in strbuf */
1451 	subtest_case_str(sb, &sub, false /* ignore op */);
1452 	if (is_subtest && !test__start_subtest(sb->buf))
1453 		return 0;
1454 
1455 	for (sub.op = first_op; sub.op <= last_op; sub.op++) {
1456 		sb->pos = 0; /* reset position in strbuf */
1457 		subtest_case_str(sb, &sub, true /* print op */);
1458 
1459 		if (env.verbosity >= VERBOSE_NORMAL) /* this speeds up debugging */
1460 			printf("TEST CASE: %s\n", sb->buf);
1461 
1462 		err = verify_case_op(init_t, cond_t, x, y, sub.op);
1463 		if (err || env.verbosity >= VERBOSE_NORMAL)
1464 			ASSERT_OK(err, sb->buf);
1465 		if (err) {
1466 			ctx->cur_failure_cnt++;
1467 			if (ctx->cur_failure_cnt > ctx->max_failure_cnt)
1468 				return err;
1469 			return 0; /* keep testing other cases */
1470 		}
1471 		ctx->case_cnt++;
1472 		if ((ctx->case_cnt % 10000) == 0) {
1473 			double progress = (ctx->case_cnt + 0.0) / ctx->total_case_cnt;
1474 			u64 elapsed_ns = get_time_ns() - ctx->start_ns;
1475 			double remain_ns = elapsed_ns / progress * (1 - progress);
1476 
1477 			fprintf(env.stderr, "PROGRESS (%s): %d/%d (%.2lf%%), "
1478 					    "elapsed %llu mins (%.2lf hrs), "
1479 					    "ETA %.0lf mins (%.2lf hrs)\n",
1480 				ctx->progress_ctx,
1481 				ctx->case_cnt, ctx->total_case_cnt, 100.0 * progress,
1482 				elapsed_ns / 1000000000 / 60,
1483 				elapsed_ns / 1000000000.0 / 3600,
1484 				remain_ns / 1000000000.0 / 60,
1485 				remain_ns / 1000000000.0 / 3600);
1486 		}
1487 	}
1488 
1489 	return 0;
1490 }
1491 
1492 static int verify_case(struct ctx *ctx, enum num_t init_t, enum num_t cond_t,
1493 		       struct range x, struct range y)
1494 {
1495 	return verify_case_opt(ctx, init_t, cond_t, x, y, true /* is_subtest */);
1496 }
1497 
1498 /* ================================
1499  * GENERATED CASES FROM SEED VALUES
1500  * ================================
1501  */
1502 static int u64_cmp(const void *p1, const void *p2)
1503 {
1504 	u64 x1 = *(const u64 *)p1, x2 = *(const u64 *)p2;
1505 
1506 	return x1 != x2 ? (x1 < x2 ? -1 : 1) : 0;
1507 }
1508 
1509 static int u32_cmp(const void *p1, const void *p2)
1510 {
1511 	u32 x1 = *(const u32 *)p1, x2 = *(const u32 *)p2;
1512 
1513 	return x1 != x2 ? (x1 < x2 ? -1 : 1) : 0;
1514 }
1515 
1516 static int s64_cmp(const void *p1, const void *p2)
1517 {
1518 	s64 x1 = *(const s64 *)p1, x2 = *(const s64 *)p2;
1519 
1520 	return x1 != x2 ? (x1 < x2 ? -1 : 1) : 0;
1521 }
1522 
1523 static int s32_cmp(const void *p1, const void *p2)
1524 {
1525 	s32 x1 = *(const s32 *)p1, x2 = *(const s32 *)p2;
1526 
1527 	return x1 != x2 ? (x1 < x2 ? -1 : 1) : 0;
1528 }
1529 
1530 /* Generate valid unique constants from seeds, both signed and unsigned */
1531 static void gen_vals(struct ctx *ctx)
1532 {
1533 	int i, j, cnt = 0;
1534 
1535 	for (i = 0; i < ARRAY_SIZE(upper_seeds); i++) {
1536 		for (j = 0; j < ARRAY_SIZE(lower_seeds); j++) {
1537 			ctx->uvals[cnt++] = (((u64)upper_seeds[i]) << 32) | lower_seeds[j];
1538 		}
1539 	}
1540 
1541 	/* sort and compact uvals (i.e., it's `sort | uniq`) */
1542 	qsort(ctx->uvals, cnt, sizeof(*ctx->uvals), u64_cmp);
1543 	for (i = 1, j = 0; i < cnt; i++) {
1544 		if (ctx->uvals[j] == ctx->uvals[i])
1545 			continue;
1546 		j++;
1547 		ctx->uvals[j] = ctx->uvals[i];
1548 	}
1549 	ctx->val_cnt = j + 1;
1550 
1551 	/* we have exactly the same number of s64 values, they are just in
1552 	 * a different order than u64s, so just sort them differently
1553 	 */
1554 	for (i = 0; i < ctx->val_cnt; i++)
1555 		ctx->svals[i] = ctx->uvals[i];
1556 	qsort(ctx->svals, ctx->val_cnt, sizeof(*ctx->svals), s64_cmp);
1557 
1558 	if (env.verbosity >= VERBOSE_SUPER) {
1559 		DEFINE_STRBUF(sb1, 256);
1560 		DEFINE_STRBUF(sb2, 256);
1561 
1562 		for (i = 0; i < ctx->val_cnt; i++) {
1563 			sb1->pos = sb2->pos = 0;
1564 			snprintf_num(U64, sb1, ctx->uvals[i]);
1565 			snprintf_num(S64, sb2, ctx->svals[i]);
1566 			printf("SEED #%d: u64=%-20s s64=%-20s\n", i, sb1->buf, sb2->buf);
1567 		}
1568 	}
1569 
1570 	/* 32-bit values are generated separately */
1571 	cnt = 0;
1572 	for (i = 0; i < ARRAY_SIZE(lower_seeds); i++) {
1573 		ctx->usubvals[cnt++] = lower_seeds[i];
1574 	}
1575 
1576 	/* sort and compact usubvals (i.e., it's `sort | uniq`) */
1577 	qsort(ctx->usubvals, cnt, sizeof(*ctx->usubvals), u32_cmp);
1578 	for (i = 1, j = 0; i < cnt; i++) {
1579 		if (ctx->usubvals[j] == ctx->usubvals[i])
1580 			continue;
1581 		j++;
1582 		ctx->usubvals[j] = ctx->usubvals[i];
1583 	}
1584 	ctx->subval_cnt = j + 1;
1585 
1586 	for (i = 0; i < ctx->subval_cnt; i++)
1587 		ctx->ssubvals[i] = ctx->usubvals[i];
1588 	qsort(ctx->ssubvals, ctx->subval_cnt, sizeof(*ctx->ssubvals), s32_cmp);
1589 
1590 	if (env.verbosity >= VERBOSE_SUPER) {
1591 		DEFINE_STRBUF(sb1, 256);
1592 		DEFINE_STRBUF(sb2, 256);
1593 
1594 		for (i = 0; i < ctx->subval_cnt; i++) {
1595 			sb1->pos = sb2->pos = 0;
1596 			snprintf_num(U32, sb1, ctx->usubvals[i]);
1597 			snprintf_num(S32, sb2, ctx->ssubvals[i]);
1598 			printf("SUBSEED #%d: u32=%-10s s32=%-10s\n", i, sb1->buf, sb2->buf);
1599 		}
1600 	}
1601 }
1602 
1603 /* Generate valid ranges from upper/lower seeds */
1604 static int gen_ranges(struct ctx *ctx)
1605 {
1606 	int i, j, cnt = 0;
1607 
1608 	for (i = 0; i < ctx->val_cnt; i++) {
1609 		for (j = i; j < ctx->val_cnt; j++) {
1610 			if (env.verbosity >= VERBOSE_SUPER) {
1611 				DEFINE_STRBUF(sb1, 256);
1612 				DEFINE_STRBUF(sb2, 256);
1613 
1614 				sb1->pos = sb2->pos = 0;
1615 				snprintf_range(U64, sb1, range(U64, ctx->uvals[i], ctx->uvals[j]));
1616 				snprintf_range(S64, sb2, range(S64, ctx->svals[i], ctx->svals[j]));
1617 				printf("RANGE #%d: u64=%-40s s64=%-40s\n", cnt, sb1->buf, sb2->buf);
1618 			}
1619 			cnt++;
1620 		}
1621 	}
1622 	ctx->range_cnt = cnt;
1623 
1624 	ctx->uranges = calloc(ctx->range_cnt, sizeof(*ctx->uranges));
1625 	if (!ASSERT_OK_PTR(ctx->uranges, "uranges_calloc"))
1626 		return -EINVAL;
1627 	ctx->sranges = calloc(ctx->range_cnt, sizeof(*ctx->sranges));
1628 	if (!ASSERT_OK_PTR(ctx->sranges, "sranges_calloc"))
1629 		return -EINVAL;
1630 
1631 	cnt = 0;
1632 	for (i = 0; i < ctx->val_cnt; i++) {
1633 		for (j = i; j < ctx->val_cnt; j++) {
1634 			ctx->uranges[cnt] = range(U64, ctx->uvals[i], ctx->uvals[j]);
1635 			ctx->sranges[cnt] = range(S64, ctx->svals[i], ctx->svals[j]);
1636 			cnt++;
1637 		}
1638 	}
1639 
1640 	cnt = 0;
1641 	for (i = 0; i < ctx->subval_cnt; i++) {
1642 		for (j = i; j < ctx->subval_cnt; j++) {
1643 			if (env.verbosity >= VERBOSE_SUPER) {
1644 				DEFINE_STRBUF(sb1, 256);
1645 				DEFINE_STRBUF(sb2, 256);
1646 
1647 				sb1->pos = sb2->pos = 0;
1648 				snprintf_range(U32, sb1, range(U32, ctx->usubvals[i], ctx->usubvals[j]));
1649 				snprintf_range(S32, sb2, range(S32, ctx->ssubvals[i], ctx->ssubvals[j]));
1650 				printf("SUBRANGE #%d: u32=%-20s s32=%-20s\n", cnt, sb1->buf, sb2->buf);
1651 			}
1652 			cnt++;
1653 		}
1654 	}
1655 	ctx->subrange_cnt = cnt;
1656 
1657 	ctx->usubranges = calloc(ctx->subrange_cnt, sizeof(*ctx->usubranges));
1658 	if (!ASSERT_OK_PTR(ctx->usubranges, "usubranges_calloc"))
1659 		return -EINVAL;
1660 	ctx->ssubranges = calloc(ctx->subrange_cnt, sizeof(*ctx->ssubranges));
1661 	if (!ASSERT_OK_PTR(ctx->ssubranges, "ssubranges_calloc"))
1662 		return -EINVAL;
1663 
1664 	cnt = 0;
1665 	for (i = 0; i < ctx->subval_cnt; i++) {
1666 		for (j = i; j < ctx->subval_cnt; j++) {
1667 			ctx->usubranges[cnt] = range(U32, ctx->usubvals[i], ctx->usubvals[j]);
1668 			ctx->ssubranges[cnt] = range(S32, ctx->ssubvals[i], ctx->ssubvals[j]);
1669 			cnt++;
1670 		}
1671 	}
1672 
1673 	return 0;
1674 }
1675 
1676 static int parse_env_vars(struct ctx *ctx)
1677 {
1678 	const char *s;
1679 
1680 	if ((s = getenv("REG_BOUNDS_MAX_FAILURE_CNT"))) {
1681 		errno = 0;
1682 		ctx->max_failure_cnt = strtol(s, NULL, 10);
1683 		if (errno || ctx->max_failure_cnt < 0) {
1684 			ASSERT_OK(-errno, "REG_BOUNDS_MAX_FAILURE_CNT");
1685 			return -EINVAL;
1686 		}
1687 	}
1688 
1689 	if ((s = getenv("REG_BOUNDS_RAND_CASE_CNT"))) {
1690 		errno = 0;
1691 		ctx->rand_case_cnt = strtol(s, NULL, 10);
1692 		if (errno || ctx->rand_case_cnt < 0) {
1693 			ASSERT_OK(-errno, "REG_BOUNDS_RAND_CASE_CNT");
1694 			return -EINVAL;
1695 		}
1696 	}
1697 
1698 	if ((s = getenv("REG_BOUNDS_RAND_SEED"))) {
1699 		errno = 0;
1700 		ctx->rand_seed = strtoul(s, NULL, 10);
1701 		if (errno) {
1702 			ASSERT_OK(-errno, "REG_BOUNDS_RAND_SEED");
1703 			return -EINVAL;
1704 		}
1705 	}
1706 
1707 	return 0;
1708 }
1709 
1710 static int prepare_gen_tests(struct ctx *ctx)
1711 {
1712 	const char *s;
1713 	int err;
1714 
1715 	if (!(s = getenv("SLOW_TESTS")) || strcmp(s, "1") != 0) {
1716 		test__skip();
1717 		return -ENOTSUP;
1718 	}
1719 
1720 	err = parse_env_vars(ctx);
1721 	if (err)
1722 		return err;
1723 
1724 	gen_vals(ctx);
1725 	err = gen_ranges(ctx);
1726 	if (err) {
1727 		ASSERT_OK(err, "gen_ranges");
1728 		return err;
1729 	}
1730 
1731 	return 0;
1732 }
1733 
1734 /* Go over generated constants and ranges and validate various supported
1735  * combinations of them
1736  */
1737 static void validate_gen_range_vs_const_64(enum num_t init_t, enum num_t cond_t)
1738 {
1739 	struct ctx ctx;
1740 	struct range rconst;
1741 	const struct range *ranges;
1742 	const u64 *vals;
1743 	int i, j;
1744 
1745 	memset(&ctx, 0, sizeof(ctx));
1746 
1747 	if (prepare_gen_tests(&ctx))
1748 		goto cleanup;
1749 
1750 	ranges = init_t == U64 ? ctx.uranges : ctx.sranges;
1751 	vals = init_t == U64 ? ctx.uvals : (const u64 *)ctx.svals;
1752 
1753 	ctx.total_case_cnt = (last_op - first_op + 1) * (2 * ctx.range_cnt * ctx.val_cnt);
1754 	ctx.start_ns = get_time_ns();
1755 	snprintf(ctx.progress_ctx, sizeof(ctx.progress_ctx),
1756 		 "RANGE x CONST, %s -> %s",
1757 		 t_str(init_t), t_str(cond_t));
1758 
1759 	for (i = 0; i < ctx.val_cnt; i++) {
1760 		for (j = 0; j < ctx.range_cnt; j++) {
1761 			rconst = range(init_t, vals[i], vals[i]);
1762 
1763 			/* (u64|s64)(<range> x <const>) */
1764 			if (verify_case(&ctx, init_t, cond_t, ranges[j], rconst))
1765 				goto cleanup;
1766 			/* (u64|s64)(<const> x <range>) */
1767 			if (verify_case(&ctx, init_t, cond_t, rconst, ranges[j]))
1768 				goto cleanup;
1769 		}
1770 	}
1771 
1772 cleanup:
1773 	cleanup_ctx(&ctx);
1774 }
1775 
1776 static void validate_gen_range_vs_const_32(enum num_t init_t, enum num_t cond_t)
1777 {
1778 	struct ctx ctx;
1779 	struct range rconst;
1780 	const struct range *ranges;
1781 	const u32 *vals;
1782 	int i, j;
1783 
1784 	memset(&ctx, 0, sizeof(ctx));
1785 
1786 	if (prepare_gen_tests(&ctx))
1787 		goto cleanup;
1788 
1789 	ranges = init_t == U32 ? ctx.usubranges : ctx.ssubranges;
1790 	vals = init_t == U32 ? ctx.usubvals : (const u32 *)ctx.ssubvals;
1791 
1792 	ctx.total_case_cnt = (last_op - first_op + 1) * (2 * ctx.subrange_cnt * ctx.subval_cnt);
1793 	ctx.start_ns = get_time_ns();
1794 	snprintf(ctx.progress_ctx, sizeof(ctx.progress_ctx),
1795 		 "RANGE x CONST, %s -> %s",
1796 		 t_str(init_t), t_str(cond_t));
1797 
1798 	for (i = 0; i < ctx.subval_cnt; i++) {
1799 		for (j = 0; j < ctx.subrange_cnt; j++) {
1800 			rconst = range(init_t, vals[i], vals[i]);
1801 
1802 			/* (u32|s32)(<range> x <const>) */
1803 			if (verify_case(&ctx, init_t, cond_t, ranges[j], rconst))
1804 				goto cleanup;
1805 			/* (u32|s32)(<const> x <range>) */
1806 			if (verify_case(&ctx, init_t, cond_t, rconst, ranges[j]))
1807 				goto cleanup;
1808 		}
1809 	}
1810 
1811 cleanup:
1812 	cleanup_ctx(&ctx);
1813 }
1814 
1815 static void validate_gen_range_vs_range(enum num_t init_t, enum num_t cond_t)
1816 {
1817 	struct ctx ctx;
1818 	const struct range *ranges;
1819 	int i, j, rcnt;
1820 
1821 	memset(&ctx, 0, sizeof(ctx));
1822 
1823 	if (prepare_gen_tests(&ctx))
1824 		goto cleanup;
1825 
1826 	switch (init_t)
1827 	{
1828 	case U64:
1829 		ranges = ctx.uranges;
1830 		rcnt = ctx.range_cnt;
1831 		break;
1832 	case U32:
1833 		ranges = ctx.usubranges;
1834 		rcnt = ctx.subrange_cnt;
1835 		break;
1836 	case S64:
1837 		ranges = ctx.sranges;
1838 		rcnt = ctx.range_cnt;
1839 		break;
1840 	case S32:
1841 		ranges = ctx.ssubranges;
1842 		rcnt = ctx.subrange_cnt;
1843 		break;
1844 	default:
1845 		printf("validate_gen_range_vs_range!\n");
1846 		exit(1);
1847 	}
1848 
1849 	ctx.total_case_cnt = (last_op - first_op + 1) * (2 * rcnt * (rcnt + 1) / 2);
1850 	ctx.start_ns = get_time_ns();
1851 	snprintf(ctx.progress_ctx, sizeof(ctx.progress_ctx),
1852 		 "RANGE x RANGE, %s -> %s",
1853 		 t_str(init_t), t_str(cond_t));
1854 
1855 	for (i = 0; i < rcnt; i++) {
1856 		for (j = i; j < rcnt; j++) {
1857 			/* (<range> x <range>) */
1858 			if (verify_case(&ctx, init_t, cond_t, ranges[i], ranges[j]))
1859 				goto cleanup;
1860 			if (verify_case(&ctx, init_t, cond_t, ranges[j], ranges[i]))
1861 				goto cleanup;
1862 		}
1863 	}
1864 
1865 cleanup:
1866 	cleanup_ctx(&ctx);
1867 }
1868 
1869 /* Go over thousands of test cases generated from initial seed values.
1870  * Given this take a long time, guard this begind SLOW_TESTS=1 envvar. If
1871  * envvar is not set, this test is skipped during test_progs testing.
1872  *
1873  * We split this up into smaller subsets based on initialization and
1874  * conditiona numeric domains to get an easy parallelization with test_progs'
1875  * -j argument.
1876  */
1877 
1878 /* RANGE x CONST, U64 initial range */
1879 void test_reg_bounds_gen_consts_u64_u64(void) { validate_gen_range_vs_const_64(U64, U64); }
1880 void test_reg_bounds_gen_consts_u64_s64(void) { validate_gen_range_vs_const_64(U64, S64); }
1881 void test_reg_bounds_gen_consts_u64_u32(void) { validate_gen_range_vs_const_64(U64, U32); }
1882 void test_reg_bounds_gen_consts_u64_s32(void) { validate_gen_range_vs_const_64(U64, S32); }
1883 /* RANGE x CONST, S64 initial range */
1884 void test_reg_bounds_gen_consts_s64_u64(void) { validate_gen_range_vs_const_64(S64, U64); }
1885 void test_reg_bounds_gen_consts_s64_s64(void) { validate_gen_range_vs_const_64(S64, S64); }
1886 void test_reg_bounds_gen_consts_s64_u32(void) { validate_gen_range_vs_const_64(S64, U32); }
1887 void test_reg_bounds_gen_consts_s64_s32(void) { validate_gen_range_vs_const_64(S64, S32); }
1888 /* RANGE x CONST, U32 initial range */
1889 void test_reg_bounds_gen_consts_u32_u64(void) { validate_gen_range_vs_const_32(U32, U64); }
1890 void test_reg_bounds_gen_consts_u32_s64(void) { validate_gen_range_vs_const_32(U32, S64); }
1891 void test_reg_bounds_gen_consts_u32_u32(void) { validate_gen_range_vs_const_32(U32, U32); }
1892 void test_reg_bounds_gen_consts_u32_s32(void) { validate_gen_range_vs_const_32(U32, S32); }
1893 /* RANGE x CONST, S32 initial range */
1894 void test_reg_bounds_gen_consts_s32_u64(void) { validate_gen_range_vs_const_32(S32, U64); }
1895 void test_reg_bounds_gen_consts_s32_s64(void) { validate_gen_range_vs_const_32(S32, S64); }
1896 void test_reg_bounds_gen_consts_s32_u32(void) { validate_gen_range_vs_const_32(S32, U32); }
1897 void test_reg_bounds_gen_consts_s32_s32(void) { validate_gen_range_vs_const_32(S32, S32); }
1898 
1899 /* RANGE x RANGE, U64 initial range */
1900 void test_reg_bounds_gen_ranges_u64_u64(void) { validate_gen_range_vs_range(U64, U64); }
1901 void test_reg_bounds_gen_ranges_u64_s64(void) { validate_gen_range_vs_range(U64, S64); }
1902 void test_reg_bounds_gen_ranges_u64_u32(void) { validate_gen_range_vs_range(U64, U32); }
1903 void test_reg_bounds_gen_ranges_u64_s32(void) { validate_gen_range_vs_range(U64, S32); }
1904 /* RANGE x RANGE, S64 initial range */
1905 void test_reg_bounds_gen_ranges_s64_u64(void) { validate_gen_range_vs_range(S64, U64); }
1906 void test_reg_bounds_gen_ranges_s64_s64(void) { validate_gen_range_vs_range(S64, S64); }
1907 void test_reg_bounds_gen_ranges_s64_u32(void) { validate_gen_range_vs_range(S64, U32); }
1908 void test_reg_bounds_gen_ranges_s64_s32(void) { validate_gen_range_vs_range(S64, S32); }
1909 /* RANGE x RANGE, U32 initial range */
1910 void test_reg_bounds_gen_ranges_u32_u64(void) { validate_gen_range_vs_range(U32, U64); }
1911 void test_reg_bounds_gen_ranges_u32_s64(void) { validate_gen_range_vs_range(U32, S64); }
1912 void test_reg_bounds_gen_ranges_u32_u32(void) { validate_gen_range_vs_range(U32, U32); }
1913 void test_reg_bounds_gen_ranges_u32_s32(void) { validate_gen_range_vs_range(U32, S32); }
1914 /* RANGE x RANGE, S32 initial range */
1915 void test_reg_bounds_gen_ranges_s32_u64(void) { validate_gen_range_vs_range(S32, U64); }
1916 void test_reg_bounds_gen_ranges_s32_s64(void) { validate_gen_range_vs_range(S32, S64); }
1917 void test_reg_bounds_gen_ranges_s32_u32(void) { validate_gen_range_vs_range(S32, U32); }
1918 void test_reg_bounds_gen_ranges_s32_s32(void) { validate_gen_range_vs_range(S32, S32); }
1919 
1920 #define DEFAULT_RAND_CASE_CNT 100
1921 
1922 #define RAND_21BIT_MASK ((1 << 22) - 1)
1923 
1924 static u64 rand_u64()
1925 {
1926 	/* RAND_MAX is guaranteed to be at least 1<<15, but in practice it
1927 	 * seems to be 1<<31, so we need to call it thrice to get full u64;
1928 	 * we'll use rougly equal split: 22 + 21 + 21 bits
1929 	 */
1930 	return ((u64)random() << 42) |
1931 	       (((u64)random() & RAND_21BIT_MASK) << 21) |
1932 	       (random() & RAND_21BIT_MASK);
1933 }
1934 
1935 static u64 rand_const(enum num_t t)
1936 {
1937 	return cast_t(t, rand_u64());
1938 }
1939 
1940 static struct range rand_range(enum num_t t)
1941 {
1942 	u64 x = rand_const(t), y = rand_const(t);
1943 
1944 	return range(t, min_t(t, x, y), max_t(t, x, y));
1945 }
1946 
1947 static void validate_rand_ranges(enum num_t init_t, enum num_t cond_t, bool const_range)
1948 {
1949 	struct ctx ctx;
1950 	struct range range1, range2;
1951 	int err, i;
1952 	u64 t;
1953 
1954 	memset(&ctx, 0, sizeof(ctx));
1955 
1956 	err = parse_env_vars(&ctx);
1957 	if (err) {
1958 		ASSERT_OK(err, "parse_env_vars");
1959 		return;
1960 	}
1961 
1962 	if (ctx.rand_case_cnt == 0)
1963 		ctx.rand_case_cnt = DEFAULT_RAND_CASE_CNT;
1964 	if (ctx.rand_seed == 0)
1965 		ctx.rand_seed = (unsigned)get_time_ns();
1966 
1967 	srandom(ctx.rand_seed);
1968 
1969 	ctx.total_case_cnt = (last_op - first_op + 1) * (2 * ctx.rand_case_cnt);
1970 	ctx.start_ns = get_time_ns();
1971 	snprintf(ctx.progress_ctx, sizeof(ctx.progress_ctx),
1972 		 "[RANDOM SEED %u] RANGE x %s, %s -> %s",
1973 		 ctx.rand_seed, const_range ? "CONST" : "RANGE",
1974 		 t_str(init_t), t_str(cond_t));
1975 
1976 	for (i = 0; i < ctx.rand_case_cnt; i++) {
1977 		range1 = rand_range(init_t);
1978 		if (const_range) {
1979 			t = rand_const(init_t);
1980 			range2 = range(init_t, t, t);
1981 		} else {
1982 			range2 = rand_range(init_t);
1983 		}
1984 
1985 		/* <range1> x <range2> */
1986 		if (verify_case_opt(&ctx, init_t, cond_t, range1, range2, false /* !is_subtest */))
1987 			goto cleanup;
1988 		/* <range2> x <range1> */
1989 		if (verify_case_opt(&ctx, init_t, cond_t, range2, range1, false /* !is_subtest */))
1990 			goto cleanup;
1991 	}
1992 
1993 cleanup:
1994 	/* make sure we report random seed for reproducing */
1995 	ASSERT_TRUE(true, ctx.progress_ctx);
1996 	cleanup_ctx(&ctx);
1997 }
1998 
1999 /* [RANDOM] RANGE x CONST, U64 initial range */
2000 void test_reg_bounds_rand_consts_u64_u64(void) { validate_rand_ranges(U64, U64, true /* const */); }
2001 void test_reg_bounds_rand_consts_u64_s64(void) { validate_rand_ranges(U64, S64, true /* const */); }
2002 void test_reg_bounds_rand_consts_u64_u32(void) { validate_rand_ranges(U64, U32, true /* const */); }
2003 void test_reg_bounds_rand_consts_u64_s32(void) { validate_rand_ranges(U64, S32, true /* const */); }
2004 /* [RANDOM] RANGE x CONST, S64 initial range */
2005 void test_reg_bounds_rand_consts_s64_u64(void) { validate_rand_ranges(S64, U64, true /* const */); }
2006 void test_reg_bounds_rand_consts_s64_s64(void) { validate_rand_ranges(S64, S64, true /* const */); }
2007 void test_reg_bounds_rand_consts_s64_u32(void) { validate_rand_ranges(S64, U32, true /* const */); }
2008 void test_reg_bounds_rand_consts_s64_s32(void) { validate_rand_ranges(S64, S32, true /* const */); }
2009 /* [RANDOM] RANGE x CONST, U32 initial range */
2010 void test_reg_bounds_rand_consts_u32_u64(void) { validate_rand_ranges(U32, U64, true /* const */); }
2011 void test_reg_bounds_rand_consts_u32_s64(void) { validate_rand_ranges(U32, S64, true /* const */); }
2012 void test_reg_bounds_rand_consts_u32_u32(void) { validate_rand_ranges(U32, U32, true /* const */); }
2013 void test_reg_bounds_rand_consts_u32_s32(void) { validate_rand_ranges(U32, S32, true /* const */); }
2014 /* [RANDOM] RANGE x CONST, S32 initial range */
2015 void test_reg_bounds_rand_consts_s32_u64(void) { validate_rand_ranges(S32, U64, true /* const */); }
2016 void test_reg_bounds_rand_consts_s32_s64(void) { validate_rand_ranges(S32, S64, true /* const */); }
2017 void test_reg_bounds_rand_consts_s32_u32(void) { validate_rand_ranges(S32, U32, true /* const */); }
2018 void test_reg_bounds_rand_consts_s32_s32(void) { validate_rand_ranges(S32, S32, true /* const */); }
2019 
2020 /* [RANDOM] RANGE x RANGE, U64 initial range */
2021 void test_reg_bounds_rand_ranges_u64_u64(void) { validate_rand_ranges(U64, U64, false /* range */); }
2022 void test_reg_bounds_rand_ranges_u64_s64(void) { validate_rand_ranges(U64, S64, false /* range */); }
2023 void test_reg_bounds_rand_ranges_u64_u32(void) { validate_rand_ranges(U64, U32, false /* range */); }
2024 void test_reg_bounds_rand_ranges_u64_s32(void) { validate_rand_ranges(U64, S32, false /* range */); }
2025 /* [RANDOM] RANGE x RANGE, S64 initial range */
2026 void test_reg_bounds_rand_ranges_s64_u64(void) { validate_rand_ranges(S64, U64, false /* range */); }
2027 void test_reg_bounds_rand_ranges_s64_s64(void) { validate_rand_ranges(S64, S64, false /* range */); }
2028 void test_reg_bounds_rand_ranges_s64_u32(void) { validate_rand_ranges(S64, U32, false /* range */); }
2029 void test_reg_bounds_rand_ranges_s64_s32(void) { validate_rand_ranges(S64, S32, false /* range */); }
2030 /* [RANDOM] RANGE x RANGE, U32 initial range */
2031 void test_reg_bounds_rand_ranges_u32_u64(void) { validate_rand_ranges(U32, U64, false /* range */); }
2032 void test_reg_bounds_rand_ranges_u32_s64(void) { validate_rand_ranges(U32, S64, false /* range */); }
2033 void test_reg_bounds_rand_ranges_u32_u32(void) { validate_rand_ranges(U32, U32, false /* range */); }
2034 void test_reg_bounds_rand_ranges_u32_s32(void) { validate_rand_ranges(U32, S32, false /* range */); }
2035 /* [RANDOM] RANGE x RANGE, S32 initial range */
2036 void test_reg_bounds_rand_ranges_s32_u64(void) { validate_rand_ranges(S32, U64, false /* range */); }
2037 void test_reg_bounds_rand_ranges_s32_s64(void) { validate_rand_ranges(S32, S64, false /* range */); }
2038 void test_reg_bounds_rand_ranges_s32_u32(void) { validate_rand_ranges(S32, U32, false /* range */); }
2039 void test_reg_bounds_rand_ranges_s32_s32(void) { validate_rand_ranges(S32, S32, false /* range */); }
2040 
2041 /* A set of hard-coded "interesting" cases to validate as part of normal
2042  * test_progs test runs
2043  */
2044 static struct subtest_case crafted_cases[] = {
2045 	{U64, U64, {0, 0xffffffff}, {0, 0}},
2046 	{U64, U64, {0, 0x80000000}, {0, 0}},
2047 	{U64, U64, {0x100000000ULL, 0x100000100ULL}, {0, 0}},
2048 	{U64, U64, {0x100000000ULL, 0x180000000ULL}, {0, 0}},
2049 	{U64, U64, {0x100000000ULL, 0x1ffffff00ULL}, {0, 0}},
2050 	{U64, U64, {0x100000000ULL, 0x1ffffff01ULL}, {0, 0}},
2051 	{U64, U64, {0x100000000ULL, 0x1fffffffeULL}, {0, 0}},
2052 	{U64, U64, {0x100000001ULL, 0x1000000ffULL}, {0, 0}},
2053 
2054 	/* single point overlap, interesting BPF_EQ and BPF_NE interactions */
2055 	{U64, U64, {0, 1}, {1, 0x80000000}},
2056 	{U64, S64, {0, 1}, {1, 0x80000000}},
2057 	{U64, U32, {0, 1}, {1, 0x80000000}},
2058 	{U64, S32, {0, 1}, {1, 0x80000000}},
2059 
2060 	{U64, S64, {0, 0xffffffff00000000ULL}, {0, 0}},
2061 	{U64, S64, {0x7fffffffffffffffULL, 0xffffffff00000000ULL}, {0, 0}},
2062 	{U64, S64, {0x7fffffff00000001ULL, 0xffffffff00000000ULL}, {0, 0}},
2063 	{U64, S64, {0, 0xffffffffULL}, {1, 1}},
2064 	{U64, S64, {0, 0xffffffffULL}, {0x7fffffff, 0x7fffffff}},
2065 
2066 	{U64, U32, {0, 0x100000000}, {0, 0}},
2067 	{U64, U32, {0xfffffffe, 0x100000000}, {0x80000000, 0x80000000}},
2068 
2069 	{U64, S32, {0, 0xffffffff00000000ULL}, {0, 0}},
2070 	/* these are tricky cases where lower 32 bits allow to tighten 64
2071 	 * bit boundaries based on tightened lower 32 bit boundaries
2072 	 */
2073 	{U64, S32, {0, 0x0ffffffffULL}, {0, 0}},
2074 	{U64, S32, {0, 0x100000000ULL}, {0, 0}},
2075 	{U64, S32, {0, 0x100000001ULL}, {0, 0}},
2076 	{U64, S32, {0, 0x180000000ULL}, {0, 0}},
2077 	{U64, S32, {0, 0x17fffffffULL}, {0, 0}},
2078 	{U64, S32, {0, 0x180000001ULL}, {0, 0}},
2079 
2080 	/* verifier knows about [-1, 0] range for s32 for this case already */
2081 	{S64, S64, {0xffffffffffffffffULL, 0}, {0xffffffff00000000ULL, 0xffffffff00000000ULL}},
2082 	/* but didn't know about these cases initially */
2083 	{U64, U64, {0xffffffff, 0x100000000ULL}, {0, 0}}, /* s32: [-1, 0] */
2084 	{U64, U64, {0xffffffff, 0x100000001ULL}, {0, 0}}, /* s32: [-1, 1] */
2085 
2086 	/* longer convergence case: learning from u64 -> s64 -> u64 -> u32,
2087 	 * arriving at u32: [1, U32_MAX] (instead of more pessimistic [0, U32_MAX])
2088 	 */
2089 	{S64, U64, {0xffffffff00000001ULL, 0}, {0xffffffff00000000ULL, 0xffffffff00000000ULL}},
2090 
2091 	{U32, U32, {1, U32_MAX}, {0, 0}},
2092 
2093 	{U32, S32, {0, U32_MAX}, {U32_MAX, U32_MAX}},
2094 
2095 	{S32, U64, {(u32)S32_MIN, (u32)S32_MIN}, {(u32)(s32)-255, 0}},
2096 	{S32, S64, {(u32)S32_MIN, (u32)(s32)-255}, {(u32)(s32)-2, 0}},
2097 	{S32, S64, {0, 1}, {(u32)S32_MIN, (u32)S32_MIN}},
2098 	{S32, U32, {(u32)S32_MIN, (u32)S32_MIN}, {(u32)S32_MIN, (u32)S32_MIN}},
2099 
2100 	/* edge overlap testings for BPF_NE */
2101 	{U64, U64, {0, U64_MAX}, {U64_MAX, U64_MAX}},
2102 	{U64, U64, {0, U64_MAX}, {0, 0}},
2103 	{S64, U64, {S64_MIN, 0}, {S64_MIN, S64_MIN}},
2104 	{S64, U64, {S64_MIN, 0}, {0, 0}},
2105 	{S64, U64, {S64_MIN, S64_MAX}, {S64_MAX, S64_MAX}},
2106 	{U32, U32, {0, U32_MAX}, {0, 0}},
2107 	{U32, U32, {0, U32_MAX}, {U32_MAX, U32_MAX}},
2108 	{S32, U32, {(u32)S32_MIN, 0}, {0, 0}},
2109 	{S32, U32, {(u32)S32_MIN, 0}, {(u32)S32_MIN, (u32)S32_MIN}},
2110 	{S32, U32, {(u32)S32_MIN, S32_MAX}, {S32_MAX, S32_MAX}},
2111 };
2112 
2113 /* Go over crafted hard-coded cases. This is fast, so we do it as part of
2114  * normal test_progs run.
2115  */
2116 void test_reg_bounds_crafted(void)
2117 {
2118 	struct ctx ctx;
2119 	int i;
2120 
2121 	memset(&ctx, 0, sizeof(ctx));
2122 
2123 	for (i = 0; i < ARRAY_SIZE(crafted_cases); i++) {
2124 		struct subtest_case *c = &crafted_cases[i];
2125 
2126 		verify_case(&ctx, c->init_t, c->cond_t, c->x, c->y);
2127 		verify_case(&ctx, c->init_t, c->cond_t, c->y, c->x);
2128 	}
2129 
2130 	cleanup_ctx(&ctx);
2131 }
2132