1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3 * Copyright (c) 2016 Facebook
4 * Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
5 */
6 #include <uapi/linux/btf.h>
7 #include <linux/kernel.h>
8 #include <linux/types.h>
9 #include <linux/bpf.h>
10 #include <linux/bpf_verifier.h>
11 #include <linux/math64.h>
12 #include <linux/string.h>
13
14 #define verbose(env, fmt, args...) bpf_verifier_log_write(env, fmt, ##args)
15
bpf_verifier_log_attr_valid(const struct bpf_verifier_log * log)16 static bool bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log)
17 {
18 /* ubuf and len_total should both be specified (or not) together */
19 if (!!log->ubuf != !!log->len_total)
20 return false;
21 /* log buf without log_level is meaningless */
22 if (log->ubuf && log->level == 0)
23 return false;
24 if (log->level & ~BPF_LOG_MASK)
25 return false;
26 if (log->len_total > UINT_MAX >> 2)
27 return false;
28 return true;
29 }
30
bpf_vlog_init(struct bpf_verifier_log * log,u32 log_level,char __user * log_buf,u32 log_size)31 int bpf_vlog_init(struct bpf_verifier_log *log, u32 log_level,
32 char __user *log_buf, u32 log_size)
33 {
34 log->level = log_level;
35 log->ubuf = log_buf;
36 log->len_total = log_size;
37
38 /* log attributes have to be sane */
39 if (!bpf_verifier_log_attr_valid(log))
40 return -EINVAL;
41
42 return 0;
43 }
44
bpf_vlog_update_len_max(struct bpf_verifier_log * log,u32 add_len)45 static void bpf_vlog_update_len_max(struct bpf_verifier_log *log, u32 add_len)
46 {
47 /* add_len includes terminal \0, so no need for +1. */
48 u64 len = log->end_pos + add_len;
49
50 /* log->len_max could be larger than our current len due to
51 * bpf_vlog_reset() calls, so we maintain the max of any length at any
52 * previous point
53 */
54 if (len > UINT_MAX)
55 log->len_max = UINT_MAX;
56 else if (len > log->len_max)
57 log->len_max = len;
58 }
59
bpf_verifier_vlog(struct bpf_verifier_log * log,const char * fmt,va_list args)60 void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt,
61 va_list args)
62 {
63 u64 cur_pos;
64 u32 new_n, n;
65
66 n = vscnprintf(log->kbuf, BPF_VERIFIER_TMP_LOG_SIZE, fmt, args);
67
68 if (log->level == BPF_LOG_KERNEL) {
69 bool newline = n > 0 && log->kbuf[n - 1] == '\n';
70
71 pr_err("BPF: %s%s", log->kbuf, newline ? "" : "\n");
72 return;
73 }
74
75 n += 1; /* include terminating zero */
76 bpf_vlog_update_len_max(log, n);
77
78 if (log->level & BPF_LOG_FIXED) {
79 /* check if we have at least something to put into user buf */
80 new_n = 0;
81 if (log->end_pos < log->len_total) {
82 new_n = min_t(u32, log->len_total - log->end_pos, n);
83 log->kbuf[new_n - 1] = '\0';
84 }
85
86 cur_pos = log->end_pos;
87 log->end_pos += n - 1; /* don't count terminating '\0' */
88
89 if (log->ubuf && new_n &&
90 copy_to_user(log->ubuf + cur_pos, log->kbuf, new_n))
91 goto fail;
92 } else {
93 u64 new_end, new_start;
94 u32 buf_start, buf_end, new_n;
95
96 new_end = log->end_pos + n;
97 if (new_end - log->start_pos >= log->len_total)
98 new_start = new_end - log->len_total;
99 else
100 new_start = log->start_pos;
101
102 log->start_pos = new_start;
103 log->end_pos = new_end - 1; /* don't count terminating '\0' */
104
105 if (!log->ubuf)
106 return;
107
108 new_n = min(n, log->len_total);
109 cur_pos = new_end - new_n;
110 div_u64_rem(cur_pos, log->len_total, &buf_start);
111 div_u64_rem(new_end, log->len_total, &buf_end);
112 /* new_end and buf_end are exclusive indices, so if buf_end is
113 * exactly zero, then it actually points right to the end of
114 * ubuf and there is no wrap around
115 */
116 if (buf_end == 0)
117 buf_end = log->len_total;
118
119 /* if buf_start > buf_end, we wrapped around;
120 * if buf_start == buf_end, then we fill ubuf completely; we
121 * can't have buf_start == buf_end to mean that there is
122 * nothing to write, because we always write at least
123 * something, even if terminal '\0'
124 */
125 if (buf_start < buf_end) {
126 /* message fits within contiguous chunk of ubuf */
127 if (copy_to_user(log->ubuf + buf_start,
128 log->kbuf + n - new_n,
129 buf_end - buf_start))
130 goto fail;
131 } else {
132 /* message wraps around the end of ubuf, copy in two chunks */
133 if (copy_to_user(log->ubuf + buf_start,
134 log->kbuf + n - new_n,
135 log->len_total - buf_start))
136 goto fail;
137 if (copy_to_user(log->ubuf,
138 log->kbuf + n - buf_end,
139 buf_end))
140 goto fail;
141 }
142 }
143
144 return;
145 fail:
146 log->ubuf = NULL;
147 }
148
bpf_vlog_reset(struct bpf_verifier_log * log,u64 new_pos)149 void bpf_vlog_reset(struct bpf_verifier_log *log, u64 new_pos)
150 {
151 char zero = 0;
152 u32 pos;
153
154 if (WARN_ON_ONCE(new_pos > log->end_pos))
155 return;
156
157 if (!bpf_verifier_log_needed(log) || log->level == BPF_LOG_KERNEL)
158 return;
159
160 /* if position to which we reset is beyond current log window,
161 * then we didn't preserve any useful content and should adjust
162 * start_pos to end up with an empty log (start_pos == end_pos)
163 */
164 log->end_pos = new_pos;
165 if (log->end_pos < log->start_pos)
166 log->start_pos = log->end_pos;
167
168 if (!log->ubuf)
169 return;
170
171 if (log->level & BPF_LOG_FIXED)
172 pos = log->end_pos + 1;
173 else
174 div_u64_rem(new_pos, log->len_total, &pos);
175
176 if (pos < log->len_total && put_user(zero, log->ubuf + pos))
177 log->ubuf = NULL;
178 }
179
bpf_vlog_reverse_kbuf(char * buf,int len)180 static void bpf_vlog_reverse_kbuf(char *buf, int len)
181 {
182 int i, j;
183
184 for (i = 0, j = len - 1; i < j; i++, j--)
185 swap(buf[i], buf[j]);
186 }
187
bpf_vlog_reverse_ubuf(struct bpf_verifier_log * log,int start,int end)188 static int bpf_vlog_reverse_ubuf(struct bpf_verifier_log *log, int start, int end)
189 {
190 /* we split log->kbuf into two equal parts for both ends of array */
191 int n = sizeof(log->kbuf) / 2, nn;
192 char *lbuf = log->kbuf, *rbuf = log->kbuf + n;
193
194 /* Read ubuf's section [start, end) two chunks at a time, from left
195 * and right side; within each chunk, swap all the bytes; after that
196 * reverse the order of lbuf and rbuf and write result back to ubuf.
197 * This way we'll end up with swapped contents of specified
198 * [start, end) ubuf segment.
199 */
200 while (end - start > 1) {
201 nn = min(n, (end - start ) / 2);
202
203 if (copy_from_user(lbuf, log->ubuf + start, nn))
204 return -EFAULT;
205 if (copy_from_user(rbuf, log->ubuf + end - nn, nn))
206 return -EFAULT;
207
208 bpf_vlog_reverse_kbuf(lbuf, nn);
209 bpf_vlog_reverse_kbuf(rbuf, nn);
210
211 /* we write lbuf to the right end of ubuf, while rbuf to the
212 * left one to end up with properly reversed overall ubuf
213 */
214 if (copy_to_user(log->ubuf + start, rbuf, nn))
215 return -EFAULT;
216 if (copy_to_user(log->ubuf + end - nn, lbuf, nn))
217 return -EFAULT;
218
219 start += nn;
220 end -= nn;
221 }
222
223 return 0;
224 }
225
bpf_vlog_finalize(struct bpf_verifier_log * log,u32 * log_size_actual)226 int bpf_vlog_finalize(struct bpf_verifier_log *log, u32 *log_size_actual)
227 {
228 u32 sublen;
229 int err;
230
231 *log_size_actual = 0;
232 if (!log || log->level == 0 || log->level == BPF_LOG_KERNEL)
233 return 0;
234
235 if (!log->ubuf)
236 goto skip_log_rotate;
237 /* If we never truncated log, there is nothing to move around. */
238 if (log->start_pos == 0)
239 goto skip_log_rotate;
240
241 /* Otherwise we need to rotate log contents to make it start from the
242 * buffer beginning and be a continuous zero-terminated string. Note
243 * that if log->start_pos != 0 then we definitely filled up entire log
244 * buffer with no gaps, and we just need to shift buffer contents to
245 * the left by (log->start_pos % log->len_total) bytes.
246 *
247 * Unfortunately, user buffer could be huge and we don't want to
248 * allocate temporary kernel memory of the same size just to shift
249 * contents in a straightforward fashion. Instead, we'll be clever and
250 * do in-place array rotation. This is a leetcode-style problem, which
251 * could be solved by three rotations.
252 *
253 * Let's say we have log buffer that has to be shifted left by 7 bytes
254 * (spaces and vertical bar is just for demonstrative purposes):
255 * E F G H I J K | A B C D
256 *
257 * First, we reverse entire array:
258 * D C B A | K J I H G F E
259 *
260 * Then we rotate first 4 bytes (DCBA) and separately last 7 bytes
261 * (KJIHGFE), resulting in a properly rotated array:
262 * A B C D | E F G H I J K
263 *
264 * We'll utilize log->kbuf to read user memory chunk by chunk, swap
265 * bytes, and write them back. Doing it byte-by-byte would be
266 * unnecessarily inefficient. Altogether we are going to read and
267 * write each byte twice, for total 4 memory copies between kernel and
268 * user space.
269 */
270
271 /* length of the chopped off part that will be the beginning;
272 * len(ABCD) in the example above
273 */
274 div_u64_rem(log->start_pos, log->len_total, &sublen);
275 sublen = log->len_total - sublen;
276
277 err = bpf_vlog_reverse_ubuf(log, 0, log->len_total);
278 err = err ?: bpf_vlog_reverse_ubuf(log, 0, sublen);
279 err = err ?: bpf_vlog_reverse_ubuf(log, sublen, log->len_total);
280 if (err)
281 log->ubuf = NULL;
282
283 skip_log_rotate:
284 *log_size_actual = log->len_max;
285
286 /* properly initialized log has either both ubuf!=NULL and len_total>0
287 * or ubuf==NULL and len_total==0, so if this condition doesn't hold,
288 * we got a fault somewhere along the way, so report it back
289 */
290 if (!!log->ubuf != !!log->len_total)
291 return -EFAULT;
292
293 /* did truncation actually happen? */
294 if (log->ubuf && log->len_max > log->len_total)
295 return -ENOSPC;
296
297 return 0;
298 }
299
300 /* log_level controls verbosity level of eBPF verifier.
301 * bpf_verifier_log_write() is used to dump the verification trace to the log,
302 * so the user can figure out what's wrong with the program
303 */
bpf_verifier_log_write(struct bpf_verifier_env * env,const char * fmt,...)304 __printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
305 const char *fmt, ...)
306 {
307 va_list args;
308
309 if (!bpf_verifier_log_needed(&env->log))
310 return;
311
312 va_start(args, fmt);
313 bpf_verifier_vlog(&env->log, fmt, args);
314 va_end(args);
315 }
316 EXPORT_SYMBOL_GPL(bpf_verifier_log_write);
317
bpf_log(struct bpf_verifier_log * log,const char * fmt,...)318 __printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
319 const char *fmt, ...)
320 {
321 va_list args;
322
323 if (!bpf_verifier_log_needed(log))
324 return;
325
326 va_start(args, fmt);
327 bpf_verifier_vlog(log, fmt, args);
328 va_end(args);
329 }
330 EXPORT_SYMBOL_GPL(bpf_log);
331
332 static const struct bpf_line_info *
find_linfo(const struct bpf_verifier_env * env,u32 insn_off)333 find_linfo(const struct bpf_verifier_env *env, u32 insn_off)
334 {
335 const struct bpf_line_info *linfo;
336 const struct bpf_prog *prog;
337 u32 nr_linfo;
338 int l, r, m;
339
340 prog = env->prog;
341 nr_linfo = prog->aux->nr_linfo;
342
343 if (!nr_linfo || insn_off >= prog->len)
344 return NULL;
345
346 linfo = prog->aux->linfo;
347 /* Loop invariant: linfo[l].insn_off <= insns_off.
348 * linfo[0].insn_off == 0 which always satisfies above condition.
349 * Binary search is searching for rightmost linfo entry that satisfies
350 * the above invariant, giving us the desired record that covers given
351 * instruction offset.
352 */
353 l = 0;
354 r = nr_linfo - 1;
355 while (l < r) {
356 /* (r - l + 1) / 2 means we break a tie to the right, so if:
357 * l=1, r=2, linfo[l].insn_off <= insn_off, linfo[r].insn_off > insn_off,
358 * then m=2, we see that linfo[m].insn_off > insn_off, and so
359 * r becomes 1 and we exit the loop with correct l==1.
360 * If the tie was broken to the left, m=1 would end us up in
361 * an endless loop where l and m stay at 1 and r stays at 2.
362 */
363 m = l + (r - l + 1) / 2;
364 if (linfo[m].insn_off <= insn_off)
365 l = m;
366 else
367 r = m - 1;
368 }
369
370 return &linfo[l];
371 }
372
ltrim(const char * s)373 static const char *ltrim(const char *s)
374 {
375 while (isspace(*s))
376 s++;
377
378 return s;
379 }
380
verbose_linfo(struct bpf_verifier_env * env,u32 insn_off,const char * prefix_fmt,...)381 __printf(3, 4) void verbose_linfo(struct bpf_verifier_env *env,
382 u32 insn_off,
383 const char *prefix_fmt, ...)
384 {
385 const struct bpf_line_info *linfo, *prev_linfo;
386 const struct btf *btf;
387 const char *s, *fname;
388
389 if (!bpf_verifier_log_needed(&env->log))
390 return;
391
392 prev_linfo = env->prev_linfo;
393 linfo = find_linfo(env, insn_off);
394 if (!linfo || linfo == prev_linfo)
395 return;
396
397 /* It often happens that two separate linfo records point to the same
398 * source code line, but have differing column numbers. Given verifier
399 * log doesn't emit column information, from user perspective we just
400 * end up emitting the same source code line twice unnecessarily.
401 * So instead check that previous and current linfo record point to
402 * the same file (file_name_offs match) and the same line number, and
403 * avoid emitting duplicated source code line in such case.
404 */
405 if (prev_linfo && linfo->file_name_off == prev_linfo->file_name_off &&
406 BPF_LINE_INFO_LINE_NUM(linfo->line_col) == BPF_LINE_INFO_LINE_NUM(prev_linfo->line_col))
407 return;
408
409 if (prefix_fmt) {
410 va_list args;
411
412 va_start(args, prefix_fmt);
413 bpf_verifier_vlog(&env->log, prefix_fmt, args);
414 va_end(args);
415 }
416
417 btf = env->prog->aux->btf;
418 s = ltrim(btf_name_by_offset(btf, linfo->line_off));
419 verbose(env, "%s", s); /* source code line */
420
421 s = btf_name_by_offset(btf, linfo->file_name_off);
422 /* leave only file name */
423 fname = strrchr(s, '/');
424 fname = fname ? fname + 1 : s;
425 verbose(env, " @ %s:%u\n", fname, BPF_LINE_INFO_LINE_NUM(linfo->line_col));
426
427 env->prev_linfo = linfo;
428 }
429
btf_type_name(const struct btf * btf,u32 id)430 static const char *btf_type_name(const struct btf *btf, u32 id)
431 {
432 return btf_name_by_offset(btf, btf_type_by_id(btf, id)->name_off);
433 }
434
435 /* string representation of 'enum bpf_reg_type'
436 *
437 * Note that reg_type_str() can not appear more than once in a single verbose()
438 * statement.
439 */
reg_type_str(struct bpf_verifier_env * env,enum bpf_reg_type type)440 const char *reg_type_str(struct bpf_verifier_env *env, enum bpf_reg_type type)
441 {
442 char postfix[16] = {0}, prefix[64] = {0};
443 static const char * const str[] = {
444 [NOT_INIT] = "?",
445 [SCALAR_VALUE] = "scalar",
446 [PTR_TO_CTX] = "ctx",
447 [CONST_PTR_TO_MAP] = "map_ptr",
448 [PTR_TO_MAP_VALUE] = "map_value",
449 [PTR_TO_STACK] = "fp",
450 [PTR_TO_PACKET] = "pkt",
451 [PTR_TO_PACKET_META] = "pkt_meta",
452 [PTR_TO_PACKET_END] = "pkt_end",
453 [PTR_TO_FLOW_KEYS] = "flow_keys",
454 [PTR_TO_SOCKET] = "sock",
455 [PTR_TO_SOCK_COMMON] = "sock_common",
456 [PTR_TO_TCP_SOCK] = "tcp_sock",
457 [PTR_TO_TP_BUFFER] = "tp_buffer",
458 [PTR_TO_XDP_SOCK] = "xdp_sock",
459 [PTR_TO_BTF_ID] = "ptr_",
460 [PTR_TO_MEM] = "mem",
461 [PTR_TO_ARENA] = "arena",
462 [PTR_TO_BUF] = "buf",
463 [PTR_TO_FUNC] = "func",
464 [PTR_TO_MAP_KEY] = "map_key",
465 [CONST_PTR_TO_DYNPTR] = "dynptr_ptr",
466 };
467
468 if (type & PTR_MAYBE_NULL) {
469 if (base_type(type) == PTR_TO_BTF_ID)
470 strscpy(postfix, "or_null_");
471 else
472 strscpy(postfix, "_or_null");
473 }
474
475 snprintf(prefix, sizeof(prefix), "%s%s%s%s%s%s%s",
476 type & MEM_RDONLY ? "rdonly_" : "",
477 type & MEM_RINGBUF ? "ringbuf_" : "",
478 type & MEM_USER ? "user_" : "",
479 type & MEM_PERCPU ? "percpu_" : "",
480 type & MEM_RCU ? "rcu_" : "",
481 type & PTR_UNTRUSTED ? "untrusted_" : "",
482 type & PTR_TRUSTED ? "trusted_" : ""
483 );
484
485 snprintf(env->tmp_str_buf, TMP_STR_BUF_LEN, "%s%s%s",
486 prefix, str[base_type(type)], postfix);
487 return env->tmp_str_buf;
488 }
489
dynptr_type_str(enum bpf_dynptr_type type)490 const char *dynptr_type_str(enum bpf_dynptr_type type)
491 {
492 switch (type) {
493 case BPF_DYNPTR_TYPE_LOCAL:
494 return "local";
495 case BPF_DYNPTR_TYPE_RINGBUF:
496 return "ringbuf";
497 case BPF_DYNPTR_TYPE_SKB:
498 return "skb";
499 case BPF_DYNPTR_TYPE_XDP:
500 return "xdp";
501 case BPF_DYNPTR_TYPE_INVALID:
502 return "<invalid>";
503 default:
504 WARN_ONCE(1, "unknown dynptr type %d\n", type);
505 return "<unknown>";
506 }
507 }
508
iter_type_str(const struct btf * btf,u32 btf_id)509 const char *iter_type_str(const struct btf *btf, u32 btf_id)
510 {
511 if (!btf || btf_id == 0)
512 return "<invalid>";
513
514 /* we already validated that type is valid and has conforming name */
515 return btf_type_name(btf, btf_id) + sizeof(ITER_PREFIX) - 1;
516 }
517
iter_state_str(enum bpf_iter_state state)518 const char *iter_state_str(enum bpf_iter_state state)
519 {
520 switch (state) {
521 case BPF_ITER_STATE_ACTIVE:
522 return "active";
523 case BPF_ITER_STATE_DRAINED:
524 return "drained";
525 case BPF_ITER_STATE_INVALID:
526 return "<invalid>";
527 default:
528 WARN_ONCE(1, "unknown iter state %d\n", state);
529 return "<unknown>";
530 }
531 }
532
533 static char slot_type_char[] = {
534 [STACK_INVALID] = '?',
535 [STACK_SPILL] = 'r',
536 [STACK_MISC] = 'm',
537 [STACK_ZERO] = '0',
538 [STACK_DYNPTR] = 'd',
539 [STACK_ITER] = 'i',
540 };
541
print_liveness(struct bpf_verifier_env * env,enum bpf_reg_liveness live)542 static void print_liveness(struct bpf_verifier_env *env,
543 enum bpf_reg_liveness live)
544 {
545 if (live & (REG_LIVE_READ | REG_LIVE_WRITTEN | REG_LIVE_DONE))
546 verbose(env, "_");
547 if (live & REG_LIVE_READ)
548 verbose(env, "r");
549 if (live & REG_LIVE_WRITTEN)
550 verbose(env, "w");
551 if (live & REG_LIVE_DONE)
552 verbose(env, "D");
553 }
554
555 #define UNUM_MAX_DECIMAL U16_MAX
556 #define SNUM_MAX_DECIMAL S16_MAX
557 #define SNUM_MIN_DECIMAL S16_MIN
558
is_unum_decimal(u64 num)559 static bool is_unum_decimal(u64 num)
560 {
561 return num <= UNUM_MAX_DECIMAL;
562 }
563
is_snum_decimal(s64 num)564 static bool is_snum_decimal(s64 num)
565 {
566 return num >= SNUM_MIN_DECIMAL && num <= SNUM_MAX_DECIMAL;
567 }
568
verbose_unum(struct bpf_verifier_env * env,u64 num)569 static void verbose_unum(struct bpf_verifier_env *env, u64 num)
570 {
571 if (is_unum_decimal(num))
572 verbose(env, "%llu", num);
573 else
574 verbose(env, "%#llx", num);
575 }
576
verbose_snum(struct bpf_verifier_env * env,s64 num)577 static void verbose_snum(struct bpf_verifier_env *env, s64 num)
578 {
579 if (is_snum_decimal(num))
580 verbose(env, "%lld", num);
581 else
582 verbose(env, "%#llx", num);
583 }
584
tnum_strn(char * str,size_t size,struct tnum a)585 int tnum_strn(char *str, size_t size, struct tnum a)
586 {
587 /* print as a constant, if tnum is fully known */
588 if (a.mask == 0) {
589 if (is_unum_decimal(a.value))
590 return snprintf(str, size, "%llu", a.value);
591 else
592 return snprintf(str, size, "%#llx", a.value);
593 }
594 return snprintf(str, size, "(%#llx; %#llx)", a.value, a.mask);
595 }
596 EXPORT_SYMBOL_GPL(tnum_strn);
597
print_scalar_ranges(struct bpf_verifier_env * env,const struct bpf_reg_state * reg,const char ** sep)598 static void print_scalar_ranges(struct bpf_verifier_env *env,
599 const struct bpf_reg_state *reg,
600 const char **sep)
601 {
602 /* For signed ranges, we want to unify 64-bit and 32-bit values in the
603 * output as much as possible, but there is a bit of a complication.
604 * If we choose to print values as decimals, this is natural to do,
605 * because negative 64-bit and 32-bit values >= -S32_MIN have the same
606 * representation due to sign extension. But if we choose to print
607 * them in hex format (see is_snum_decimal()), then sign extension is
608 * misleading.
609 * E.g., smin=-2 and smin32=-2 are exactly the same in decimal, but in
610 * hex they will be smin=0xfffffffffffffffe and smin32=0xfffffffe, two
611 * very different numbers.
612 * So we avoid sign extension if we choose to print values in hex.
613 */
614 struct {
615 const char *name;
616 u64 val;
617 bool omit;
618 } minmaxs[] = {
619 {"smin", reg->smin_value, reg->smin_value == S64_MIN},
620 {"smax", reg->smax_value, reg->smax_value == S64_MAX},
621 {"umin", reg->umin_value, reg->umin_value == 0},
622 {"umax", reg->umax_value, reg->umax_value == U64_MAX},
623 {"smin32",
624 is_snum_decimal((s64)reg->s32_min_value)
625 ? (s64)reg->s32_min_value
626 : (u32)reg->s32_min_value, reg->s32_min_value == S32_MIN},
627 {"smax32",
628 is_snum_decimal((s64)reg->s32_max_value)
629 ? (s64)reg->s32_max_value
630 : (u32)reg->s32_max_value, reg->s32_max_value == S32_MAX},
631 {"umin32", reg->u32_min_value, reg->u32_min_value == 0},
632 {"umax32", reg->u32_max_value, reg->u32_max_value == U32_MAX},
633 }, *m1, *m2, *mend = &minmaxs[ARRAY_SIZE(minmaxs)];
634 bool neg1, neg2;
635
636 for (m1 = &minmaxs[0]; m1 < mend; m1++) {
637 if (m1->omit)
638 continue;
639
640 neg1 = m1->name[0] == 's' && (s64)m1->val < 0;
641
642 verbose(env, "%s%s=", *sep, m1->name);
643 *sep = ",";
644
645 for (m2 = m1 + 2; m2 < mend; m2 += 2) {
646 if (m2->omit || m2->val != m1->val)
647 continue;
648 /* don't mix negatives with positives */
649 neg2 = m2->name[0] == 's' && (s64)m2->val < 0;
650 if (neg2 != neg1)
651 continue;
652 m2->omit = true;
653 verbose(env, "%s=", m2->name);
654 }
655
656 if (m1->name[0] == 's')
657 verbose_snum(env, m1->val);
658 else
659 verbose_unum(env, m1->val);
660 }
661 }
662
type_is_map_ptr(enum bpf_reg_type t)663 static bool type_is_map_ptr(enum bpf_reg_type t) {
664 switch (base_type(t)) {
665 case CONST_PTR_TO_MAP:
666 case PTR_TO_MAP_KEY:
667 case PTR_TO_MAP_VALUE:
668 return true;
669 default:
670 return false;
671 }
672 }
673
674 /*
675 * _a stands for append, was shortened to avoid multiline statements below.
676 * This macro is used to output a comma separated list of attributes.
677 */
678 #define verbose_a(fmt, ...) ({ verbose(env, "%s" fmt, sep, ##__VA_ARGS__); sep = ","; })
679
print_reg_state(struct bpf_verifier_env * env,const struct bpf_func_state * state,const struct bpf_reg_state * reg)680 static void print_reg_state(struct bpf_verifier_env *env,
681 const struct bpf_func_state *state,
682 const struct bpf_reg_state *reg)
683 {
684 enum bpf_reg_type t;
685 const char *sep = "";
686
687 t = reg->type;
688 if (t == SCALAR_VALUE && reg->precise)
689 verbose(env, "P");
690 if (t == SCALAR_VALUE && tnum_is_const(reg->var_off)) {
691 /* reg->off should be 0 for SCALAR_VALUE */
692 verbose_snum(env, reg->var_off.value + reg->off);
693 return;
694 }
695
696 verbose(env, "%s", reg_type_str(env, t));
697 if (t == PTR_TO_ARENA)
698 return;
699 if (t == PTR_TO_STACK) {
700 if (state->frameno != reg->frameno)
701 verbose(env, "[%d]", reg->frameno);
702 if (tnum_is_const(reg->var_off)) {
703 verbose_snum(env, reg->var_off.value + reg->off);
704 return;
705 }
706 }
707 if (base_type(t) == PTR_TO_BTF_ID)
708 verbose(env, "%s", btf_type_name(reg->btf, reg->btf_id));
709 verbose(env, "(");
710 if (reg->id)
711 verbose_a("id=%d", reg->id);
712 if (reg->ref_obj_id)
713 verbose_a("ref_obj_id=%d", reg->ref_obj_id);
714 if (type_is_non_owning_ref(reg->type))
715 verbose_a("%s", "non_own_ref");
716 if (type_is_map_ptr(t)) {
717 if (reg->map_ptr->name[0])
718 verbose_a("map=%s", reg->map_ptr->name);
719 verbose_a("ks=%d,vs=%d",
720 reg->map_ptr->key_size,
721 reg->map_ptr->value_size);
722 }
723 if (t != SCALAR_VALUE && reg->off) {
724 verbose_a("off=");
725 verbose_snum(env, reg->off);
726 }
727 if (type_is_pkt_pointer(t)) {
728 verbose_a("r=");
729 verbose_unum(env, reg->range);
730 }
731 if (base_type(t) == PTR_TO_MEM) {
732 verbose_a("sz=");
733 verbose_unum(env, reg->mem_size);
734 }
735 if (t == CONST_PTR_TO_DYNPTR)
736 verbose_a("type=%s", dynptr_type_str(reg->dynptr.type));
737 if (tnum_is_const(reg->var_off)) {
738 /* a pointer register with fixed offset */
739 if (reg->var_off.value) {
740 verbose_a("imm=");
741 verbose_snum(env, reg->var_off.value);
742 }
743 } else {
744 print_scalar_ranges(env, reg, &sep);
745 if (!tnum_is_unknown(reg->var_off)) {
746 char tn_buf[48];
747
748 tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
749 verbose_a("var_off=%s", tn_buf);
750 }
751 }
752 verbose(env, ")");
753 }
754
print_verifier_state(struct bpf_verifier_env * env,const struct bpf_func_state * state,bool print_all)755 void print_verifier_state(struct bpf_verifier_env *env, const struct bpf_func_state *state,
756 bool print_all)
757 {
758 const struct bpf_reg_state *reg;
759 int i;
760
761 if (state->frameno)
762 verbose(env, " frame%d:", state->frameno);
763 for (i = 0; i < MAX_BPF_REG; i++) {
764 reg = &state->regs[i];
765 if (reg->type == NOT_INIT)
766 continue;
767 if (!print_all && !reg_scratched(env, i))
768 continue;
769 verbose(env, " R%d", i);
770 print_liveness(env, reg->live);
771 verbose(env, "=");
772 print_reg_state(env, state, reg);
773 }
774 for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
775 char types_buf[BPF_REG_SIZE + 1];
776 const char *sep = "";
777 bool valid = false;
778 u8 slot_type;
779 int j;
780
781 if (!print_all && !stack_slot_scratched(env, i))
782 continue;
783
784 for (j = 0; j < BPF_REG_SIZE; j++) {
785 slot_type = state->stack[i].slot_type[j];
786 if (slot_type != STACK_INVALID)
787 valid = true;
788 types_buf[j] = slot_type_char[slot_type];
789 }
790 types_buf[BPF_REG_SIZE] = 0;
791 if (!valid)
792 continue;
793
794 reg = &state->stack[i].spilled_ptr;
795 switch (state->stack[i].slot_type[BPF_REG_SIZE - 1]) {
796 case STACK_SPILL:
797 /* print MISC/ZERO/INVALID slots above subreg spill */
798 for (j = 0; j < BPF_REG_SIZE; j++)
799 if (state->stack[i].slot_type[j] == STACK_SPILL)
800 break;
801 types_buf[j] = '\0';
802
803 verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
804 print_liveness(env, reg->live);
805 verbose(env, "=%s", types_buf);
806 print_reg_state(env, state, reg);
807 break;
808 case STACK_DYNPTR:
809 /* skip to main dynptr slot */
810 i += BPF_DYNPTR_NR_SLOTS - 1;
811 reg = &state->stack[i].spilled_ptr;
812
813 verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
814 print_liveness(env, reg->live);
815 verbose(env, "=dynptr_%s(", dynptr_type_str(reg->dynptr.type));
816 if (reg->id)
817 verbose_a("id=%d", reg->id);
818 if (reg->ref_obj_id)
819 verbose_a("ref_id=%d", reg->ref_obj_id);
820 if (reg->dynptr_id)
821 verbose_a("dynptr_id=%d", reg->dynptr_id);
822 verbose(env, ")");
823 break;
824 case STACK_ITER:
825 /* only main slot has ref_obj_id set; skip others */
826 if (!reg->ref_obj_id)
827 continue;
828
829 verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
830 print_liveness(env, reg->live);
831 verbose(env, "=iter_%s(ref_id=%d,state=%s,depth=%u)",
832 iter_type_str(reg->iter.btf, reg->iter.btf_id),
833 reg->ref_obj_id, iter_state_str(reg->iter.state),
834 reg->iter.depth);
835 break;
836 case STACK_MISC:
837 case STACK_ZERO:
838 default:
839 verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
840 print_liveness(env, reg->live);
841 verbose(env, "=%s", types_buf);
842 break;
843 }
844 }
845 if (state->acquired_refs && state->refs[0].id) {
846 verbose(env, " refs=%d", state->refs[0].id);
847 for (i = 1; i < state->acquired_refs; i++)
848 if (state->refs[i].id)
849 verbose(env, ",%d", state->refs[i].id);
850 }
851 if (state->in_callback_fn)
852 verbose(env, " cb");
853 if (state->in_async_callback_fn)
854 verbose(env, " async_cb");
855 verbose(env, "\n");
856 if (!print_all)
857 mark_verifier_state_clean(env);
858 }
859
vlog_alignment(u32 pos)860 static inline u32 vlog_alignment(u32 pos)
861 {
862 return round_up(max(pos + BPF_LOG_MIN_ALIGNMENT / 2, BPF_LOG_ALIGNMENT),
863 BPF_LOG_MIN_ALIGNMENT) - pos - 1;
864 }
865
print_insn_state(struct bpf_verifier_env * env,const struct bpf_func_state * state)866 void print_insn_state(struct bpf_verifier_env *env, const struct bpf_func_state *state)
867 {
868 if (env->prev_log_pos && env->prev_log_pos == env->log.end_pos) {
869 /* remove new line character */
870 bpf_vlog_reset(&env->log, env->prev_log_pos - 1);
871 verbose(env, "%*c;", vlog_alignment(env->prev_insn_print_pos), ' ');
872 } else {
873 verbose(env, "%d:", env->insn_idx);
874 }
875 print_verifier_state(env, state, false);
876 }
877