aboutsummaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/bpf/test_align.c
blob: 1426594fdf6bcfc1384f62f140ccc497b104077d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
#include <asm/types.h>
#include <linux/types.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stddef.h>
#include <stdbool.h>

#include <sys/resource.h>

#include <linux/unistd.h>
#include <linux/filter.h>
#include <linux/bpf_perf_event.h>
#include <linux/bpf.h>

#include <bpf/bpf.h>

#include "../../../include/linux/filter.h"

#ifndef ARRAY_SIZE
# define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
#endif

#define MAX_INSNS	512
#define MAX_MATCHES	16

struct bpf_align_test {
	const char *descr;
	struct bpf_insn	insns[MAX_INSNS];
	enum {
		UNDEF,
		ACCEPT,
		REJECT
	} result;
	enum bpf_prog_type prog_type;
	const char *matches[MAX_MATCHES];
};

static struct bpf_align_test tests[] = {
	{
		.descr = "mov",
		.insns = {
			BPF_MOV64_IMM(BPF_REG_3, 2),
			BPF_MOV64_IMM(BPF_REG_3, 4),
			BPF_MOV64_IMM(BPF_REG_3, 8),
			BPF_MOV64_IMM(BPF_REG_3, 16),
			BPF_MOV64_IMM(BPF_REG_3, 32),
			BPF_MOV64_IMM(BPF_REG_0, 0),
			BPF_EXIT_INSN(),
		},
		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
		.matches = {
			"1: R1=ctx R3=imm2,min_value=2,max_value=2,min_align=2 R10=fp",
			"2: R1=ctx R3=imm4,min_value=4,max_value=4,min_align=4 R10=fp",
			"3: R1=ctx R3=imm8,min_value=8,max_value=8,min_align=8 R10=fp",
			"4: R1=ctx R3=imm16,min_value=16,max_value=16,min_align=16 R10=fp",
			"5: R1=ctx R3=imm32,min_value=32,max_value=32,min_align=32 R10=fp",
		},
	},
	{
		.descr = "shift",
		.insns = {
			BPF_MOV64_IMM(BPF_REG_3, 1),
			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
			BPF_ALU64_IMM(BPF_RSH, BPF_REG_3, 4),
			BPF_MOV64_IMM(BPF_REG_4, 32),
			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
			BPF_MOV64_IMM(BPF_REG_0, 0),
			BPF_EXIT_INSN(),
		},
		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
		.matches = {
			"1: R1=ctx R3=imm1,min_value=1,max_value=1,min_align=1 R10=fp",
			"2: R1=ctx R3=imm2,min_value=2,max_value=2,min_align=2 R10=fp",
			"3: R1=ctx R3=imm4,min_value=4,max_value=4,min_align=4 R10=fp",
			"4: R1=ctx R3=imm8,min_value=8,max_value=8,min_align=8 R10=fp",
			"5: R1=ctx R3=imm16,min_value=16,max_value=16,min_align=16 R10=fp",
			"6: R1=ctx R3=imm1,min_value=1,max_value=1,min_align=1 R10=fp",
			"7: R1=ctx R3=imm1,min_value=1,max_value=1,min_align=1 R4=imm32,min_value=32,max_value=32,min_align=32 R10=fp",
			"8: R1=ctx R3=imm1,min_value=1,max_value=1,min_align=1 R4=imm16,min_value=16,max_value=16,min_align=16 R10=fp",
			"9: R1=ctx R3=imm1,min_value=1,max_value=1,min_align=1 R4=imm8,min_value=8,max_value=8,min_align=8 R10=fp",
			"10: R1=ctx R3=imm1,min_value=1,max_value=1,min_align=1 R4=imm4,min_value=4,max_value=4,min_align=4 R10=fp",
			"11: R1=ctx R3=imm1,min_value=1,max_value=1,min_align=1 R4=imm2,min_value=2,max_value=2,min_align=2 R10=fp",
		},
	},
	{
		.descr = "addsub",
		.insns = {
			BPF_MOV64_IMM(BPF_REG_3, 4),
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 4),
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 2),
			BPF_MOV64_IMM(BPF_REG_4, 8),
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 2),
			BPF_MOV64_IMM(BPF_REG_0, 0),
			BPF_EXIT_INSN(),
		},
		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
		.matches = {
			"1: R1=ctx R3=imm4,min_value=4,max_value=4,min_align=4 R10=fp",
			"2: R1=ctx R3=imm8,min_value=8,max_value=8,min_align=4 R10=fp",
			"3: R1=ctx R3=imm10,min_value=10,max_value=10,min_align=2 R10=fp",
			"4: R1=ctx R3=imm10,min_value=10,max_value=10,min_align=2 R4=imm8,min_value=8,max_value=8,min_align=8 R10=fp",
			"5: R1=ctx R3=imm10,min_value=10,max_value=10,min_align=2 R4=imm12,min_value=12,max_value=12,min_align=4 R10=fp",
			"6: R1=ctx R3=imm10,min_value=10,max_value=10,min_align=2 R4=imm14,min_value=14,max_value=14,min_align=2 R10=fp",
		},
	},
	{
		.descr = "mul",
		.insns = {
			BPF_MOV64_IMM(BPF_REG_3, 7),
			BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 1),
			BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 2),
			BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 4),
			BPF_MOV64_IMM(BPF_REG_0, 0),
			BPF_EXIT_INSN(),
		},
		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
		.matches = {
			"1: R1=ctx R3=imm7,min_value=7,max_value=7,min_align=1 R10=fp",
			"2: R1=ctx R3=imm7,min_value=7,max_value=7,min_align=1 R10=fp",
			"3: R1=ctx R3=imm14,min_value=14,max_value=14,min_align=2 R10=fp",
			"4: R1=ctx R3=imm56,min_value=56,max_value=56,min_align=4 R10=fp",
		},
	},

#define PREP_PKT_POINTERS \
	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, \
		    offsetof(struct __sk_buff, data)), \
	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, \
		    offsetof(struct __sk_buff, data_end))

#define LOAD_UNKNOWN(DST_REG) \
	PREP_PKT_POINTERS, \
	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), \
	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8), \
	BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_0, 1), \
	BPF_EXIT_INSN(), \
	BPF_LDX_MEM(BPF_B, DST_REG, BPF_REG_2, 0)

	{
		.descr = "unknown shift",
		.insns = {
			LOAD_UNKNOWN(BPF_REG_3),
			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
			BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
			LOAD_UNKNOWN(BPF_REG_4),
			BPF_ALU64_IMM(BPF_LSH, BPF_REG_4, 5),
			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
			BPF_MOV64_IMM(BPF_REG_0, 0),
			BPF_EXIT_INSN(),
		},
		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
		.matches = {
			"7: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv56 R10=fp",
			"8: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv55,min_align=2 R10=fp",
			"9: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv54,min_align=4 R10=fp",
			"10: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv53,min_align=8 R10=fp",
			"11: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv52,min_align=16 R10=fp",
			"18: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=inv56 R10=fp",
			"19: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=inv51,min_align=32 R10=fp",
			"20: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=inv52,min_align=16 R10=fp",
			"21: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=inv53,min_align=8 R10=fp",
			"22: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=inv54,min_align=4 R10=fp",
			"23: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=inv55,min_align=2 R10=fp",
		},
	},
	{
		.descr = "unknown mul",
		.insns = {
			LOAD_UNKNOWN(BPF_REG_3),
			BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
			BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 1),
			BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
			BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 2),
			BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
			BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 4),
			BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
			BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 8),
			BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 2),
			BPF_MOV64_IMM(BPF_REG_0, 0),
			BPF_EXIT_INSN(),
		},
		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
		.matches = {
			"7: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv56 R10=fp",
			"8: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv56 R4=inv56 R10=fp",
			"9: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv56 R4=inv55,min_align=1 R10=fp",
			"10: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv56 R4=inv56 R10=fp",
			"11: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv56 R4=inv54,min_align=2 R10=fp",
			"12: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv56 R4=inv56 R10=fp",
			"13: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv56 R4=inv53,min_align=4 R10=fp",
			"14: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv56 R4=inv56 R10=fp",
			"15: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv56 R4=inv52,min_align=8 R10=fp",
			"16: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=inv56 R4=inv50,min_align=8 R10=fp"
		},
	},
	{
		.descr = "packet const offset",
		.insns = {
			PREP_PKT_POINTERS,
			BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),

			BPF_MOV64_IMM(BPF_REG_0, 0),

			/* Skip over ethernet header.  */
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
			BPF_EXIT_INSN(),

			BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 0),
			BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 1),
			BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 2),
			BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 3),
			BPF_LDX_MEM(BPF_H, BPF_REG_4, BPF_REG_5, 0),
			BPF_LDX_MEM(BPF_H, BPF_REG_4, BPF_REG_5, 2),
			BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),

			BPF_MOV64_IMM(BPF_REG_0, 0),
			BPF_EXIT_INSN(),
		},
		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
		.matches = {
			"4: R0=imm0,min_value=0,max_value=0,min_align=2147483648 R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R5=pkt(id=0,off=0,r=0) R10=fp",
			"5: R0=imm0,min_value=0,max_value=0,min_align=2147483648 R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R5=pkt(id=0,off=14,r=0) R10=fp",
			"6: R0=imm0,min_value=0,max_value=0,min_align=2147483648 R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R4=pkt(id=0,off=14,r=0) R5=pkt(id=0,off=14,r=0) R10=fp",
			"10: R0=imm0,min_value=0,max_value=0,min_align=2147483648 R1=ctx R2=pkt(id=0,off=0,r=18) R3=pkt_end R4=inv56 R5=pkt(id=0,off=14,r=18) R10=fp",
			"14: R0=imm0,min_value=0,max_value=0,min_align=2147483648 R1=ctx R2=pkt(id=0,off=0,r=18) R3=pkt_end R4=inv48 R5=pkt(id=0,off=14,r=18) R10=fp",
			"15: R0=imm0,min_value=0,max_value=0,min_align=2147483648 R1=ctx R2=pkt(id=0,off=0,r=18) R3=pkt_end R4=inv48 R5=pkt(id=0,off=14,r=18) R10=fp",
		},
	},
	{
		.descr = "packet variable offset",
		.insns = {
			LOAD_UNKNOWN(BPF_REG_6),
			BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2),

			/* First, add a constant to the R5 packet pointer,
			 * then a variable with a known alignment.
			 */
			BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
			BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
			BPF_EXIT_INSN(),
			BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),

			/* Now, test in the other direction.  Adding first
			 * the variable offset to R5, then the constant.
			 */
			BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
			BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
			BPF_EXIT_INSN(),
			BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),

			/* Test multiple accumulations of unknown values
			 * into a packet pointer.
			 */
			BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
			BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 4),
			BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
			BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
			BPF_EXIT_INSN(),
			BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),

			BPF_MOV64_IMM(BPF_REG_0, 0),
			BPF_EXIT_INSN(),
		},
		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
		.matches = {
			/* Calculated offset in R6 has unknown value, but known
			 * alignment of 4.
			 */
			"8: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R6=inv54,min_align=4 R10=fp",

			/* Offset is added to packet pointer R5, resulting in known
			 * auxiliary alignment and offset.
			 */
			"11: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R5=pkt(id=1,off=0,r=0),aux_off=14,aux_off_align=4 R6=inv54,min_align=4 R10=fp",

			/* At the time the word size load is performed from R5,
			 * it's total offset is NET_IP_ALIGN + reg->off (0) +
			 * reg->aux_off (14) which is 16.  Then the variable
			 * offset is considered using reg->aux_off_align which
			 * is 4 and meets the load's requirements.
			 */
			"15: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=pkt(id=1,off=4,r=4),aux_off=14,aux_off_align=4 R5=pkt(id=1,off=0,r=4),aux_off=14,aux_off_align=4 R6=inv54,min_align=4 R10=fp",


			/* Variable offset is added to R5 packet pointer,
			 * resulting in auxiliary alignment of 4.
			 */
			"18: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=inv,aux_off=14,aux_off_align=4 R5=pkt(id=2,off=0,r=0),aux_off_align=4 R6=inv54,min_align=4 R10=fp",

			/* Constant offset is added to R5, resulting in
			 * reg->off of 14.
			 */
			"19: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=inv,aux_off=14,aux_off_align=4 R5=pkt(id=2,off=14,r=0),aux_off_align=4 R6=inv54,min_align=4 R10=fp",

			/* At the time the word size load is performed from R5,
			 * it's total offset is NET_IP_ALIGN + reg->off (14) which
			 * is 16.  Then the variable offset is considered using
			 * reg->aux_off_align which is 4 and meets the load's
			 * requirements.
			 */
			"23: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=pkt(id=2,off=18,r=18),aux_off_align=4 R5=pkt(id=2,off=14,r=18),aux_off_align=4 R6=inv54,min_align=4 R10=fp",

			/* Constant offset is added to R5 packet pointer,
			 * resulting in reg->off value of 14.
			 */
			"26: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=inv,aux_off_align=4 R5=pkt(id=0,off=14,r=8) R6=inv54,min_align=4 R10=fp",
			/* Variable offset is added to R5, resulting in an
			 * auxiliary offset of 14, and an auxiliary alignment of 4.
			 */
			"27: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=inv,aux_off_align=4 R5=pkt(id=3,off=0,r=0),aux_off=14,aux_off_align=4 R6=inv54,min_align=4 R10=fp",
			/* Constant is added to R5 again, setting reg->off to 4. */
			"28: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=inv,aux_off_align=4 R5=pkt(id=3,off=4,r=0),aux_off=14,aux_off_align=4 R6=inv54,min_align=4 R10=fp",
			/* And once more we add a variable, which causes an accumulation
			 * of reg->off into reg->aux_off_align, with resulting value of
			 * 18.  The auxiliary alignment stays at 4.
			 */
			"29: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=inv,aux_off_align=4 R5=pkt(id=4,off=0,r=0),aux_off=18,aux_off_align=4 R6=inv54,min_align=4 R10=fp",
			/* At the time the word size load is performed from R5,
			 * it's total offset is NET_IP_ALIGN + reg->off (0) +
			 * reg->aux_off (18) which is 20.  Then the variable offset
			 * is considered using reg->aux_off_align which is 4 and meets
			 * the load's requirements.
			 */
			"33: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R4=pkt(id=4,off=4,r=4),aux_off=18,aux_off_align=4 R5=pkt(id=4,off=0,r=4),aux_off=18,aux_off_align=4 R6=inv54,min_align=4 R10=fp",
		},
	},
};

static int probe_filter_length(const struct bpf_insn *fp)
{
	int len;

	for (len = MAX_INSNS - 1; len > 0; --len)
		if (fp[len].code != 0 || fp[len].imm != 0)
			break;
	return len + 1;
}

static char bpf_vlog[32768];

static int do_test_single(struct bpf_align_test *test)
{
	struct bpf_insn *prog = test->insns;
	int prog_type = test->prog_type;
	int prog_len, i;
	int fd_prog;
	int ret;

	prog_len = probe_filter_length(prog);
	fd_prog = bpf_verify_program(prog_type ? : BPF_PROG_TYPE_SOCKET_FILTER,
				     prog, prog_len, 1, "GPL", 0,
				     bpf_vlog, sizeof(bpf_vlog));
	if (fd_prog < 0) {
		printf("Failed to load program.\n");
		printf("%s", bpf_vlog);
		ret = 1;
	} else {
		ret = 0;
		for (i = 0; i < MAX_MATCHES; i++) {
			const char *t, *m = test->matches[i];

			if (!m)
				break;
			t = strstr(bpf_vlog, m);
			if (!t) {
				printf("Failed to find match: %s\n", m);
				ret = 1;
				printf("%s", bpf_vlog);
				break;
			}
		}
		close(fd_prog);
	}
	return ret;
}

static int do_test(unsigned int from, unsigned int to)
{
	int all_pass = 0;
	int all_fail = 0;
	unsigned int i;

	for (i = from; i < to; i++) {
		struct bpf_align_test *test = &tests[i];
		int fail;

		printf("Test %3d: %s ... ",
		       i, test->descr);
		fail = do_test_single(test);
		if (fail) {
			all_fail++;
			printf("FAIL\n");
		} else {
			all_pass++;
			printf("PASS\n");
		}
	}
	printf("Results: %d pass %d fail\n",
	       all_pass, all_fail);
	return 0;
}

int main(int argc, char **argv)
{
	unsigned int from = 0, to = ARRAY_SIZE(tests);
	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };

	setrlimit(RLIMIT_MEMLOCK, &rinf);

	if (argc == 3) {
		unsigned int l = atoi(argv[argc - 2]);
		unsigned int u = atoi(argv[argc - 1]);

		if (l < to && u < to) {
			from = l;
			to   = u + 1;
		}
	} else if (argc == 2) {
		unsigned int t = atoi(argv[argc - 1]);

		if (t < to) {
			from = t;
			to   = t + 1;
		}
	}
	return do_test(from, to);
}