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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Linux Socket Filter - Kernel level socket filtering
4 *
5 * Based on the design of the Berkeley Packet Filter. The new
6 * internal format has been designed by PLUMgrid:
7 *
8 * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
9 *
10 * Authors:
11 *
12 * Jay Schulist <jschlst@samba.org>
13 * Alexei Starovoitov <ast@plumgrid.com>
14 * Daniel Borkmann <dborkman@redhat.com>
15 *
16 * Andi Kleen - Fix a few bad bugs and races.
17 * Kris Katterjohn - Added many additional checks in bpf_check_classic()
18 */
19
20#include <uapi/linux/btf.h>
21#include <linux/filter.h>
22#include <linux/skbuff.h>
23#include <linux/vmalloc.h>
24#include <linux/random.h>
25#include <linux/moduleloader.h>
26#include <linux/bpf.h>
27#include <linux/btf.h>
28#include <linux/frame.h>
29#include <linux/rbtree_latch.h>
30#include <linux/kallsyms.h>
31#include <linux/rcupdate.h>
32#include <linux/perf_event.h>
33
34#include <asm/unaligned.h>
35
36/* Registers */
37#define BPF_R0 regs[BPF_REG_0]
38#define BPF_R1 regs[BPF_REG_1]
39#define BPF_R2 regs[BPF_REG_2]
40#define BPF_R3 regs[BPF_REG_3]
41#define BPF_R4 regs[BPF_REG_4]
42#define BPF_R5 regs[BPF_REG_5]
43#define BPF_R6 regs[BPF_REG_6]
44#define BPF_R7 regs[BPF_REG_7]
45#define BPF_R8 regs[BPF_REG_8]
46#define BPF_R9 regs[BPF_REG_9]
47#define BPF_R10 regs[BPF_REG_10]
48
49/* Named registers */
50#define DST regs[insn->dst_reg]
51#define SRC regs[insn->src_reg]
52#define FP regs[BPF_REG_FP]
53#define AX regs[BPF_REG_AX]
54#define ARG1 regs[BPF_REG_ARG1]
55#define CTX regs[BPF_REG_CTX]
56#define IMM insn->imm
57
58/* No hurry in this branch
59 *
60 * Exported for the bpf jit load helper.
61 */
62void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
63{
64 u8 *ptr = NULL;
65
66 if (k >= SKF_NET_OFF)
67 ptr = skb_network_header(skb) + k - SKF_NET_OFF;
68 else if (k >= SKF_LL_OFF)
69 ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
70
71 if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
72 return ptr;
73
74 return NULL;
75}
76
77struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
78{
79 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
80 struct bpf_prog_aux *aux;
81 struct bpf_prog *fp;
82
83 size = round_up(size, PAGE_SIZE);
84 fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
85 if (fp == NULL)
86 return NULL;
87
88 aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
89 if (aux == NULL) {
90 vfree(fp);
91 return NULL;
92 }
93
94 fp->pages = size / PAGE_SIZE;
95 fp->aux = aux;
96 fp->aux->prog = fp;
97 fp->jit_requested = ebpf_jit_enabled();
98
99 INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode);
100
101 return fp;
102}
103
104struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
105{
106 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
107 struct bpf_prog *prog;
108 int cpu;
109
110 prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
111 if (!prog)
112 return NULL;
113
114 prog->aux->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
115 if (!prog->aux->stats) {
116 kfree(prog->aux);
117 vfree(prog);
118 return NULL;
119 }
120
121 for_each_possible_cpu(cpu) {
122 struct bpf_prog_stats *pstats;
123
124 pstats = per_cpu_ptr(prog->aux->stats, cpu);
125 u64_stats_init(&pstats->syncp);
126 }
127 return prog;
128}
129EXPORT_SYMBOL_GPL(bpf_prog_alloc);
130
131int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
132{
133 if (!prog->aux->nr_linfo || !prog->jit_requested)
134 return 0;
135
136 prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo,
137 sizeof(*prog->aux->jited_linfo),
138 GFP_KERNEL | __GFP_NOWARN);
139 if (!prog->aux->jited_linfo)
140 return -ENOMEM;
141
142 return 0;
143}
144
145void bpf_prog_free_jited_linfo(struct bpf_prog *prog)
146{
147 kfree(prog->aux->jited_linfo);
148 prog->aux->jited_linfo = NULL;
149}
150
151void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog)
152{
153 if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0])
154 bpf_prog_free_jited_linfo(prog);
155}
156
157/* The jit engine is responsible to provide an array
158 * for insn_off to the jited_off mapping (insn_to_jit_off).
159 *
160 * The idx to this array is the insn_off. Hence, the insn_off
161 * here is relative to the prog itself instead of the main prog.
162 * This array has one entry for each xlated bpf insn.
163 *
164 * jited_off is the byte off to the last byte of the jited insn.
165 *
166 * Hence, with
167 * insn_start:
168 * The first bpf insn off of the prog. The insn off
169 * here is relative to the main prog.
170 * e.g. if prog is a subprog, insn_start > 0
171 * linfo_idx:
172 * The prog's idx to prog->aux->linfo and jited_linfo
173 *
174 * jited_linfo[linfo_idx] = prog->bpf_func
175 *
176 * For i > linfo_idx,
177 *
178 * jited_linfo[i] = prog->bpf_func +
179 * insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
180 */
181void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
182 const u32 *insn_to_jit_off)
183{
184 u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
185 const struct bpf_line_info *linfo;
186 void **jited_linfo;
187
188 if (!prog->aux->jited_linfo)
189 /* Userspace did not provide linfo */
190 return;
191
192 linfo_idx = prog->aux->linfo_idx;
193 linfo = &prog->aux->linfo[linfo_idx];
194 insn_start = linfo[0].insn_off;
195 insn_end = insn_start + prog->len;
196
197 jited_linfo = &prog->aux->jited_linfo[linfo_idx];
198 jited_linfo[0] = prog->bpf_func;
199
200 nr_linfo = prog->aux->nr_linfo - linfo_idx;
201
202 for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
203 /* The verifier ensures that linfo[i].insn_off is
204 * strictly increasing
205 */
206 jited_linfo[i] = prog->bpf_func +
207 insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
208}
209
210void bpf_prog_free_linfo(struct bpf_prog *prog)
211{
212 bpf_prog_free_jited_linfo(prog);
213 kvfree(prog->aux->linfo);
214}
215
216struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
217 gfp_t gfp_extra_flags)
218{
219 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
220 struct bpf_prog *fp;
221 u32 pages, delta;
222 int ret;
223
224 BUG_ON(fp_old == NULL);
225
226 size = round_up(size, PAGE_SIZE);
227 pages = size / PAGE_SIZE;
228 if (pages <= fp_old->pages)
229 return fp_old;
230
231 delta = pages - fp_old->pages;
232 ret = __bpf_prog_charge(fp_old->aux->user, delta);
233 if (ret)
234 return NULL;
235
236 fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
237 if (fp == NULL) {
238 __bpf_prog_uncharge(fp_old->aux->user, delta);
239 } else {
240 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
241 fp->pages = pages;
242 fp->aux->prog = fp;
243
244 /* We keep fp->aux from fp_old around in the new
245 * reallocated structure.
246 */
247 fp_old->aux = NULL;
248 __bpf_prog_free(fp_old);
249 }
250
251 return fp;
252}
253
254void __bpf_prog_free(struct bpf_prog *fp)
255{
256 if (fp->aux) {
257 free_percpu(fp->aux->stats);
258 kfree(fp->aux);
259 }
260 vfree(fp);
261}
262
263int bpf_prog_calc_tag(struct bpf_prog *fp)
264{
265 const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64);
266 u32 raw_size = bpf_prog_tag_scratch_size(fp);
267 u32 digest[SHA_DIGEST_WORDS];
268 u32 ws[SHA_WORKSPACE_WORDS];
269 u32 i, bsize, psize, blocks;
270 struct bpf_insn *dst;
271 bool was_ld_map;
272 u8 *raw, *todo;
273 __be32 *result;
274 __be64 *bits;
275
276 raw = vmalloc(raw_size);
277 if (!raw)
278 return -ENOMEM;
279
280 sha_init(digest);
281 memset(ws, 0, sizeof(ws));
282
283 /* We need to take out the map fd for the digest calculation
284 * since they are unstable from user space side.
285 */
286 dst = (void *)raw;
287 for (i = 0, was_ld_map = false; i < fp->len; i++) {
288 dst[i] = fp->insnsi[i];
289 if (!was_ld_map &&
290 dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
291 (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
292 dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
293 was_ld_map = true;
294 dst[i].imm = 0;
295 } else if (was_ld_map &&
296 dst[i].code == 0 &&
297 dst[i].dst_reg == 0 &&
298 dst[i].src_reg == 0 &&
299 dst[i].off == 0) {
300 was_ld_map = false;
301 dst[i].imm = 0;
302 } else {
303 was_ld_map = false;
304 }
305 }
306
307 psize = bpf_prog_insn_size(fp);
308 memset(&raw[psize], 0, raw_size - psize);
309 raw[psize++] = 0x80;
310
311 bsize = round_up(psize, SHA_MESSAGE_BYTES);
312 blocks = bsize / SHA_MESSAGE_BYTES;
313 todo = raw;
314 if (bsize - psize >= sizeof(__be64)) {
315 bits = (__be64 *)(todo + bsize - sizeof(__be64));
316 } else {
317 bits = (__be64 *)(todo + bsize + bits_offset);
318 blocks++;
319 }
320 *bits = cpu_to_be64((psize - 1) << 3);
321
322 while (blocks--) {
323 sha_transform(digest, todo, ws);
324 todo += SHA_MESSAGE_BYTES;
325 }
326
327 result = (__force __be32 *)digest;
328 for (i = 0; i < SHA_DIGEST_WORDS; i++)
329 result[i] = cpu_to_be32(digest[i]);
330 memcpy(fp->tag, result, sizeof(fp->tag));
331
332 vfree(raw);
333 return 0;
334}
335
336static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
337 s32 end_new, s32 curr, const bool probe_pass)
338{
339 const s64 imm_min = S32_MIN, imm_max = S32_MAX;
340 s32 delta = end_new - end_old;
341 s64 imm = insn->imm;
342
343 if (curr < pos && curr + imm + 1 >= end_old)
344 imm += delta;
345 else if (curr >= end_new && curr + imm + 1 < end_new)
346 imm -= delta;
347 if (imm < imm_min || imm > imm_max)
348 return -ERANGE;
349 if (!probe_pass)
350 insn->imm = imm;
351 return 0;
352}
353
354static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
355 s32 end_new, s32 curr, const bool probe_pass)
356{
357 const s32 off_min = S16_MIN, off_max = S16_MAX;
358 s32 delta = end_new - end_old;
359 s32 off = insn->off;
360
361 if (curr < pos && curr + off + 1 >= end_old)
362 off += delta;
363 else if (curr >= end_new && curr + off + 1 < end_new)
364 off -= delta;
365 if (off < off_min || off > off_max)
366 return -ERANGE;
367 if (!probe_pass)
368 insn->off = off;
369 return 0;
370}
371
372static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
373 s32 end_new, const bool probe_pass)
374{
375 u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
376 struct bpf_insn *insn = prog->insnsi;
377 int ret = 0;
378
379 for (i = 0; i < insn_cnt; i++, insn++) {
380 u8 code;
381
382 /* In the probing pass we still operate on the original,
383 * unpatched image in order to check overflows before we
384 * do any other adjustments. Therefore skip the patchlet.
385 */
386 if (probe_pass && i == pos) {
387 i = end_new;
388 insn = prog->insnsi + end_old;
389 }
390 code = insn->code;
391 if ((BPF_CLASS(code) != BPF_JMP &&
392 BPF_CLASS(code) != BPF_JMP32) ||
393 BPF_OP(code) == BPF_EXIT)
394 continue;
395 /* Adjust offset of jmps if we cross patch boundaries. */
396 if (BPF_OP(code) == BPF_CALL) {
397 if (insn->src_reg != BPF_PSEUDO_CALL)
398 continue;
399 ret = bpf_adj_delta_to_imm(insn, pos, end_old,
400 end_new, i, probe_pass);
401 } else {
402 ret = bpf_adj_delta_to_off(insn, pos, end_old,
403 end_new, i, probe_pass);
404 }
405 if (ret)
406 break;
407 }
408
409 return ret;
410}
411
412static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
413{
414 struct bpf_line_info *linfo;
415 u32 i, nr_linfo;
416
417 nr_linfo = prog->aux->nr_linfo;
418 if (!nr_linfo || !delta)
419 return;
420
421 linfo = prog->aux->linfo;
422
423 for (i = 0; i < nr_linfo; i++)
424 if (off < linfo[i].insn_off)
425 break;
426
427 /* Push all off < linfo[i].insn_off by delta */
428 for (; i < nr_linfo; i++)
429 linfo[i].insn_off += delta;
430}
431
432struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
433 const struct bpf_insn *patch, u32 len)
434{
435 u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
436 const u32 cnt_max = S16_MAX;
437 struct bpf_prog *prog_adj;
438 int err;
439
440 /* Since our patchlet doesn't expand the image, we're done. */
441 if (insn_delta == 0) {
442 memcpy(prog->insnsi + off, patch, sizeof(*patch));
443 return prog;
444 }
445
446 insn_adj_cnt = prog->len + insn_delta;
447
448 /* Reject anything that would potentially let the insn->off
449 * target overflow when we have excessive program expansions.
450 * We need to probe here before we do any reallocation where
451 * we afterwards may not fail anymore.
452 */
453 if (insn_adj_cnt > cnt_max &&
454 (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
455 return ERR_PTR(err);
456
457 /* Several new instructions need to be inserted. Make room
458 * for them. Likely, there's no need for a new allocation as
459 * last page could have large enough tailroom.
460 */
461 prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
462 GFP_USER);
463 if (!prog_adj)
464 return ERR_PTR(-ENOMEM);
465
466 prog_adj->len = insn_adj_cnt;
467
468 /* Patching happens in 3 steps:
469 *
470 * 1) Move over tail of insnsi from next instruction onwards,
471 * so we can patch the single target insn with one or more
472 * new ones (patching is always from 1 to n insns, n > 0).
473 * 2) Inject new instructions at the target location.
474 * 3) Adjust branch offsets if necessary.
475 */
476 insn_rest = insn_adj_cnt - off - len;
477
478 memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
479 sizeof(*patch) * insn_rest);
480 memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
481
482 /* We are guaranteed to not fail at this point, otherwise
483 * the ship has sailed to reverse to the original state. An
484 * overflow cannot happen at this point.
485 */
486 BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
487
488 bpf_adj_linfo(prog_adj, off, insn_delta);
489
490 return prog_adj;
491}
492
493int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
494{
495 /* Branch offsets can't overflow when program is shrinking, no need
496 * to call bpf_adj_branches(..., true) here
497 */
498 memmove(prog->insnsi + off, prog->insnsi + off + cnt,
499 sizeof(struct bpf_insn) * (prog->len - off - cnt));
500 prog->len -= cnt;
501
502 return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
503}
504
505static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
506{
507 int i;
508
509 for (i = 0; i < fp->aux->func_cnt; i++)
510 bpf_prog_kallsyms_del(fp->aux->func[i]);
511}
512
513void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
514{
515 bpf_prog_kallsyms_del_subprogs(fp);
516 bpf_prog_kallsyms_del(fp);
517}
518
519#ifdef CONFIG_BPF_JIT
520/* All BPF JIT sysctl knobs here. */
521int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON);
522int bpf_jit_harden __read_mostly;
523int bpf_jit_kallsyms __read_mostly;
524long bpf_jit_limit __read_mostly;
525
526static __always_inline void
527bpf_get_prog_addr_region(const struct bpf_prog *prog,
528 unsigned long *symbol_start,
529 unsigned long *symbol_end)
530{
531 const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog);
532 unsigned long addr = (unsigned long)hdr;
533
534 WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
535
536 *symbol_start = addr;
537 *symbol_end = addr + hdr->pages * PAGE_SIZE;
538}
539
540void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
541{
542 const char *end = sym + KSYM_NAME_LEN;
543 const struct btf_type *type;
544 const char *func_name;
545
546 BUILD_BUG_ON(sizeof("bpf_prog_") +
547 sizeof(prog->tag) * 2 +
548 /* name has been null terminated.
549 * We should need +1 for the '_' preceding
550 * the name. However, the null character
551 * is double counted between the name and the
552 * sizeof("bpf_prog_") above, so we omit
553 * the +1 here.
554 */
555 sizeof(prog->aux->name) > KSYM_NAME_LEN);
556
557 sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
558 sym = bin2hex(sym, prog->tag, sizeof(prog->tag));
559
560 /* prog->aux->name will be ignored if full btf name is available */
561 if (prog->aux->func_info_cnt) {
562 type = btf_type_by_id(prog->aux->btf,
563 prog->aux->func_info[prog->aux->func_idx].type_id);
564 func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
565 snprintf(sym, (size_t)(end - sym), "_%s", func_name);
566 return;
567 }
568
569 if (prog->aux->name[0])
570 snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
571 else
572 *sym = 0;
573}
574
575static __always_inline unsigned long
576bpf_get_prog_addr_start(struct latch_tree_node *n)
577{
578 unsigned long symbol_start, symbol_end;
579 const struct bpf_prog_aux *aux;
580
581 aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
582 bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
583
584 return symbol_start;
585}
586
587static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
588 struct latch_tree_node *b)
589{
590 return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b);
591}
592
593static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
594{
595 unsigned long val = (unsigned long)key;
596 unsigned long symbol_start, symbol_end;
597 const struct bpf_prog_aux *aux;
598
599 aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
600 bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
601
602 if (val < symbol_start)
603 return -1;
604 if (val >= symbol_end)
605 return 1;
606
607 return 0;
608}
609
610static const struct latch_tree_ops bpf_tree_ops = {
611 .less = bpf_tree_less,
612 .comp = bpf_tree_comp,
613};
614
615static DEFINE_SPINLOCK(bpf_lock);
616static LIST_HEAD(bpf_kallsyms);
617static struct latch_tree_root bpf_tree __cacheline_aligned;
618
619static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux)
620{
621 WARN_ON_ONCE(!list_empty(&aux->ksym_lnode));
622 list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms);
623 latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
624}
625
626static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux)
627{
628 if (list_empty(&aux->ksym_lnode))
629 return;
630
631 latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
632 list_del_rcu(&aux->ksym_lnode);
633}
634
635static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
636{
637 return fp->jited && !bpf_prog_was_classic(fp);
638}
639
640static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp)
641{
642 return list_empty(&fp->aux->ksym_lnode) ||
643 fp->aux->ksym_lnode.prev == LIST_POISON2;
644}
645
646void bpf_prog_kallsyms_add(struct bpf_prog *fp)
647{
648 if (!bpf_prog_kallsyms_candidate(fp) ||
649 !capable(CAP_SYS_ADMIN))
650 return;
651
652 spin_lock_bh(&bpf_lock);
653 bpf_prog_ksym_node_add(fp->aux);
654 spin_unlock_bh(&bpf_lock);
655}
656
657void bpf_prog_kallsyms_del(struct bpf_prog *fp)
658{
659 if (!bpf_prog_kallsyms_candidate(fp))
660 return;
661
662 spin_lock_bh(&bpf_lock);
663 bpf_prog_ksym_node_del(fp->aux);
664 spin_unlock_bh(&bpf_lock);
665}
666
667static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
668{
669 struct latch_tree_node *n;
670
671 if (!bpf_jit_kallsyms_enabled())
672 return NULL;
673
674 n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
675 return n ?
676 container_of(n, struct bpf_prog_aux, ksym_tnode)->prog :
677 NULL;
678}
679
680const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
681 unsigned long *off, char *sym)
682{
683 unsigned long symbol_start, symbol_end;
684 struct bpf_prog *prog;
685 char *ret = NULL;
686
687 rcu_read_lock();
688 prog = bpf_prog_kallsyms_find(addr);
689 if (prog) {
690 bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end);
691 bpf_get_prog_name(prog, sym);
692
693 ret = sym;
694 if (size)
695 *size = symbol_end - symbol_start;
696 if (off)
697 *off = addr - symbol_start;
698 }
699 rcu_read_unlock();
700
701 return ret;
702}
703
704bool is_bpf_text_address(unsigned long addr)
705{
706 bool ret;
707
708 rcu_read_lock();
709 ret = bpf_prog_kallsyms_find(addr) != NULL;
710 rcu_read_unlock();
711
712 return ret;
713}
714
715int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
716 char *sym)
717{
718 struct bpf_prog_aux *aux;
719 unsigned int it = 0;
720 int ret = -ERANGE;
721
722 if (!bpf_jit_kallsyms_enabled())
723 return ret;
724
725 rcu_read_lock();
726 list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) {
727 if (it++ != symnum)
728 continue;
729
730 bpf_get_prog_name(aux->prog, sym);
731
732 *value = (unsigned long)aux->prog->bpf_func;
733 *type = BPF_SYM_ELF_TYPE;
734
735 ret = 0;
736 break;
737 }
738 rcu_read_unlock();
739
740 return ret;
741}
742
743static atomic_long_t bpf_jit_current;
744
745/* Can be overridden by an arch's JIT compiler if it has a custom,
746 * dedicated BPF backend memory area, or if neither of the two
747 * below apply.
748 */
749u64 __weak bpf_jit_alloc_exec_limit(void)
750{
751#if defined(MODULES_VADDR)
752 return MODULES_END - MODULES_VADDR;
753#else
754 return VMALLOC_END - VMALLOC_START;
755#endif
756}
757
758static int __init bpf_jit_charge_init(void)
759{
760 /* Only used as heuristic here to derive limit. */
761 bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2,
762 PAGE_SIZE), LONG_MAX);
763 return 0;
764}
765pure_initcall(bpf_jit_charge_init);
766
767static int bpf_jit_charge_modmem(u32 pages)
768{
769 if (atomic_long_add_return(pages, &bpf_jit_current) >
770 (bpf_jit_limit >> PAGE_SHIFT)) {
771 if (!capable(CAP_SYS_ADMIN)) {
772 atomic_long_sub(pages, &bpf_jit_current);
773 return -EPERM;
774 }
775 }
776
777 return 0;
778}
779
780static void bpf_jit_uncharge_modmem(u32 pages)
781{
782 atomic_long_sub(pages, &bpf_jit_current);
783}
784
785void *__weak bpf_jit_alloc_exec(unsigned long size)
786{
787 return module_alloc(size);
788}
789
790void __weak bpf_jit_free_exec(void *addr)
791{
792 module_memfree(addr);
793}
794
795struct bpf_binary_header *
796bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
797 unsigned int alignment,
798 bpf_jit_fill_hole_t bpf_fill_ill_insns)
799{
800 struct bpf_binary_header *hdr;
801 u32 size, hole, start, pages;
802
803 /* Most of BPF filters are really small, but if some of them
804 * fill a page, allow at least 128 extra bytes to insert a
805 * random section of illegal instructions.
806 */
807 size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
808 pages = size / PAGE_SIZE;
809
810 if (bpf_jit_charge_modmem(pages))
811 return NULL;
812 hdr = bpf_jit_alloc_exec(size);
813 if (!hdr) {
814 bpf_jit_uncharge_modmem(pages);
815 return NULL;
816 }
817
818 /* Fill space with illegal/arch-dep instructions. */
819 bpf_fill_ill_insns(hdr, size);
820
821 hdr->pages = pages;
822 hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
823 PAGE_SIZE - sizeof(*hdr));
824 start = (get_random_int() % hole) & ~(alignment - 1);
825
826 /* Leave a random number of instructions before BPF code. */
827 *image_ptr = &hdr->image[start];
828
829 return hdr;
830}
831
832void bpf_jit_binary_free(struct bpf_binary_header *hdr)
833{
834 u32 pages = hdr->pages;
835
836 bpf_jit_free_exec(hdr);
837 bpf_jit_uncharge_modmem(pages);
838}
839
840/* This symbol is only overridden by archs that have different
841 * requirements than the usual eBPF JITs, f.e. when they only
842 * implement cBPF JIT, do not set images read-only, etc.
843 */
844void __weak bpf_jit_free(struct bpf_prog *fp)
845{
846 if (fp->jited) {
847 struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
848
849 bpf_jit_binary_free(hdr);
850
851 WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
852 }
853
854 bpf_prog_unlock_free(fp);
855}
856
857int bpf_jit_get_func_addr(const struct bpf_prog *prog,
858 const struct bpf_insn *insn, bool extra_pass,
859 u64 *func_addr, bool *func_addr_fixed)
860{
861 s16 off = insn->off;
862 s32 imm = insn->imm;
863 u8 *addr;
864
865 *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
866 if (!*func_addr_fixed) {
867 /* Place-holder address till the last pass has collected
868 * all addresses for JITed subprograms in which case we
869 * can pick them up from prog->aux.
870 */
871 if (!extra_pass)
872 addr = NULL;
873 else if (prog->aux->func &&
874 off >= 0 && off < prog->aux->func_cnt)
875 addr = (u8 *)prog->aux->func[off]->bpf_func;
876 else
877 return -EINVAL;
878 } else {
879 /* Address of a BPF helper call. Since part of the core
880 * kernel, it's always at a fixed location. __bpf_call_base
881 * and the helper with imm relative to it are both in core
882 * kernel.
883 */
884 addr = (u8 *)__bpf_call_base + imm;
885 }
886
887 *func_addr = (unsigned long)addr;
888 return 0;
889}
890
891static int bpf_jit_blind_insn(const struct bpf_insn *from,
892 const struct bpf_insn *aux,
893 struct bpf_insn *to_buff,
894 bool emit_zext)
895{
896 struct bpf_insn *to = to_buff;
897 u32 imm_rnd = get_random_int();
898 s16 off;
899
900 BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG);
901 BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
902
903 /* Constraints on AX register:
904 *
905 * AX register is inaccessible from user space. It is mapped in
906 * all JITs, and used here for constant blinding rewrites. It is
907 * typically "stateless" meaning its contents are only valid within
908 * the executed instruction, but not across several instructions.
909 * There are a few exceptions however which are further detailed
910 * below.
911 *
912 * Constant blinding is only used by JITs, not in the interpreter.
913 * The interpreter uses AX in some occasions as a local temporary
914 * register e.g. in DIV or MOD instructions.
915 *
916 * In restricted circumstances, the verifier can also use the AX
917 * register for rewrites as long as they do not interfere with
918 * the above cases!
919 */
920 if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
921 goto out;
922
923 if (from->imm == 0 &&
924 (from->code == (BPF_ALU | BPF_MOV | BPF_K) ||
925 from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
926 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
927 goto out;
928 }
929
930 switch (from->code) {
931 case BPF_ALU | BPF_ADD | BPF_K:
932 case BPF_ALU | BPF_SUB | BPF_K:
933 case BPF_ALU | BPF_AND | BPF_K:
934 case BPF_ALU | BPF_OR | BPF_K:
935 case BPF_ALU | BPF_XOR | BPF_K:
936 case BPF_ALU | BPF_MUL | BPF_K:
937 case BPF_ALU | BPF_MOV | BPF_K:
938 case BPF_ALU | BPF_DIV | BPF_K:
939 case BPF_ALU | BPF_MOD | BPF_K:
940 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
941 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
942 *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
943 break;
944
945 case BPF_ALU64 | BPF_ADD | BPF_K:
946 case BPF_ALU64 | BPF_SUB | BPF_K:
947 case BPF_ALU64 | BPF_AND | BPF_K:
948 case BPF_ALU64 | BPF_OR | BPF_K:
949 case BPF_ALU64 | BPF_XOR | BPF_K:
950 case BPF_ALU64 | BPF_MUL | BPF_K:
951 case BPF_ALU64 | BPF_MOV | BPF_K:
952 case BPF_ALU64 | BPF_DIV | BPF_K:
953 case BPF_ALU64 | BPF_MOD | BPF_K:
954 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
955 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
956 *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
957 break;
958
959 case BPF_JMP | BPF_JEQ | BPF_K:
960 case BPF_JMP | BPF_JNE | BPF_K:
961 case BPF_JMP | BPF_JGT | BPF_K:
962 case BPF_JMP | BPF_JLT | BPF_K:
963 case BPF_JMP | BPF_JGE | BPF_K:
964 case BPF_JMP | BPF_JLE | BPF_K:
965 case BPF_JMP | BPF_JSGT | BPF_K:
966 case BPF_JMP | BPF_JSLT | BPF_K:
967 case BPF_JMP | BPF_JSGE | BPF_K:
968 case BPF_JMP | BPF_JSLE | BPF_K:
969 case BPF_JMP | BPF_JSET | BPF_K:
970 /* Accommodate for extra offset in case of a backjump. */
971 off = from->off;
972 if (off < 0)
973 off -= 2;
974 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
975 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
976 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
977 break;
978
979 case BPF_JMP32 | BPF_JEQ | BPF_K:
980 case BPF_JMP32 | BPF_JNE | BPF_K:
981 case BPF_JMP32 | BPF_JGT | BPF_K:
982 case BPF_JMP32 | BPF_JLT | BPF_K:
983 case BPF_JMP32 | BPF_JGE | BPF_K:
984 case BPF_JMP32 | BPF_JLE | BPF_K:
985 case BPF_JMP32 | BPF_JSGT | BPF_K:
986 case BPF_JMP32 | BPF_JSLT | BPF_K:
987 case BPF_JMP32 | BPF_JSGE | BPF_K:
988 case BPF_JMP32 | BPF_JSLE | BPF_K:
989 case BPF_JMP32 | BPF_JSET | BPF_K:
990 /* Accommodate for extra offset in case of a backjump. */
991 off = from->off;
992 if (off < 0)
993 off -= 2;
994 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
995 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
996 *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
997 off);
998 break;
999
1000 case BPF_LD | BPF_IMM | BPF_DW:
1001 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1002 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1003 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1004 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1005 break;
1006 case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1007 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1008 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1009 if (emit_zext)
1010 *to++ = BPF_ZEXT_REG(BPF_REG_AX);
1011 *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX);
1012 break;
1013
1014 case BPF_ST | BPF_MEM | BPF_DW:
1015 case BPF_ST | BPF_MEM | BPF_W:
1016 case BPF_ST | BPF_MEM | BPF_H:
1017 case BPF_ST | BPF_MEM | BPF_B:
1018 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1019 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1020 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1021 break;
1022 }
1023out:
1024 return to - to_buff;
1025}
1026
1027static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1028 gfp_t gfp_extra_flags)
1029{
1030 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1031 struct bpf_prog *fp;
1032
1033 fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL);
1034 if (fp != NULL) {
1035 /* aux->prog still points to the fp_other one, so
1036 * when promoting the clone to the real program,
1037 * this still needs to be adapted.
1038 */
1039 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1040 }
1041
1042 return fp;
1043}
1044
1045static void bpf_prog_clone_free(struct bpf_prog *fp)
1046{
1047 /* aux was stolen by the other clone, so we cannot free
1048 * it from this path! It will be freed eventually by the
1049 * other program on release.
1050 *
1051 * At this point, we don't need a deferred release since
1052 * clone is guaranteed to not be locked.
1053 */
1054 fp->aux = NULL;
1055 __bpf_prog_free(fp);
1056}
1057
1058void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1059{
1060 /* We have to repoint aux->prog to self, as we don't
1061 * know whether fp here is the clone or the original.
1062 */
1063 fp->aux->prog = fp;
1064 bpf_prog_clone_free(fp_other);
1065}
1066
1067struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1068{
1069 struct bpf_insn insn_buff[16], aux[2];
1070 struct bpf_prog *clone, *tmp;
1071 int insn_delta, insn_cnt;
1072 struct bpf_insn *insn;
1073 int i, rewritten;
1074
1075 if (!bpf_jit_blinding_enabled(prog) || prog->blinded)
1076 return prog;
1077
1078 clone = bpf_prog_clone_create(prog, GFP_USER);
1079 if (!clone)
1080 return ERR_PTR(-ENOMEM);
1081
1082 insn_cnt = clone->len;
1083 insn = clone->insnsi;
1084
1085 for (i = 0; i < insn_cnt; i++, insn++) {
1086 /* We temporarily need to hold the original ld64 insn
1087 * so that we can still access the first part in the
1088 * second blinding run.
1089 */
1090 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1091 insn[1].code == 0)
1092 memcpy(aux, insn, sizeof(aux));
1093
1094 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1095 clone->aux->verifier_zext);
1096 if (!rewritten)
1097 continue;
1098
1099 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1100 if (IS_ERR(tmp)) {
1101 /* Patching may have repointed aux->prog during
1102 * realloc from the original one, so we need to
1103 * fix it up here on error.
1104 */
1105 bpf_jit_prog_release_other(prog, clone);
1106 return tmp;
1107 }
1108
1109 clone = tmp;
1110 insn_delta = rewritten - 1;
1111
1112 /* Walk new program and skip insns we just inserted. */
1113 insn = clone->insnsi + i + insn_delta;
1114 insn_cnt += insn_delta;
1115 i += insn_delta;
1116 }
1117
1118 clone->blinded = 1;
1119 return clone;
1120}
1121#endif /* CONFIG_BPF_JIT */
1122
1123/* Base function for offset calculation. Needs to go into .text section,
1124 * therefore keeping it non-static as well; will also be used by JITs
1125 * anyway later on, so do not let the compiler omit it. This also needs
1126 * to go into kallsyms for correlation from e.g. bpftool, so naming
1127 * must not change.
1128 */
1129noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1130{
1131 return 0;
1132}
1133EXPORT_SYMBOL_GPL(__bpf_call_base);
1134
1135/* All UAPI available opcodes. */
1136#define BPF_INSN_MAP(INSN_2, INSN_3) \
1137 /* 32 bit ALU operations. */ \
1138 /* Register based. */ \
1139 INSN_3(ALU, ADD, X), \
1140 INSN_3(ALU, SUB, X), \
1141 INSN_3(ALU, AND, X), \
1142 INSN_3(ALU, OR, X), \
1143 INSN_3(ALU, LSH, X), \
1144 INSN_3(ALU, RSH, X), \
1145 INSN_3(ALU, XOR, X), \
1146 INSN_3(ALU, MUL, X), \
1147 INSN_3(ALU, MOV, X), \
1148 INSN_3(ALU, ARSH, X), \
1149 INSN_3(ALU, DIV, X), \
1150 INSN_3(ALU, MOD, X), \
1151 INSN_2(ALU, NEG), \
1152 INSN_3(ALU, END, TO_BE), \
1153 INSN_3(ALU, END, TO_LE), \
1154 /* Immediate based. */ \
1155 INSN_3(ALU, ADD, K), \
1156 INSN_3(ALU, SUB, K), \
1157 INSN_3(ALU, AND, K), \
1158 INSN_3(ALU, OR, K), \
1159 INSN_3(ALU, LSH, K), \
1160 INSN_3(ALU, RSH, K), \
1161 INSN_3(ALU, XOR, K), \
1162 INSN_3(ALU, MUL, K), \
1163 INSN_3(ALU, MOV, K), \
1164 INSN_3(ALU, ARSH, K), \
1165 INSN_3(ALU, DIV, K), \
1166 INSN_3(ALU, MOD, K), \
1167 /* 64 bit ALU operations. */ \
1168 /* Register based. */ \
1169 INSN_3(ALU64, ADD, X), \
1170 INSN_3(ALU64, SUB, X), \
1171 INSN_3(ALU64, AND, X), \
1172 INSN_3(ALU64, OR, X), \
1173 INSN_3(ALU64, LSH, X), \
1174 INSN_3(ALU64, RSH, X), \
1175 INSN_3(ALU64, XOR, X), \
1176 INSN_3(ALU64, MUL, X), \
1177 INSN_3(ALU64, MOV, X), \
1178 INSN_3(ALU64, ARSH, X), \
1179 INSN_3(ALU64, DIV, X), \
1180 INSN_3(ALU64, MOD, X), \
1181 INSN_2(ALU64, NEG), \
1182 /* Immediate based. */ \
1183 INSN_3(ALU64, ADD, K), \
1184 INSN_3(ALU64, SUB, K), \
1185 INSN_3(ALU64, AND, K), \
1186 INSN_3(ALU64, OR, K), \
1187 INSN_3(ALU64, LSH, K), \
1188 INSN_3(ALU64, RSH, K), \
1189 INSN_3(ALU64, XOR, K), \
1190 INSN_3(ALU64, MUL, K), \
1191 INSN_3(ALU64, MOV, K), \
1192 INSN_3(ALU64, ARSH, K), \
1193 INSN_3(ALU64, DIV, K), \
1194 INSN_3(ALU64, MOD, K), \
1195 /* Call instruction. */ \
1196 INSN_2(JMP, CALL), \
1197 /* Exit instruction. */ \
1198 INSN_2(JMP, EXIT), \
1199 /* 32-bit Jump instructions. */ \
1200 /* Register based. */ \
1201 INSN_3(JMP32, JEQ, X), \
1202 INSN_3(JMP32, JNE, X), \
1203 INSN_3(JMP32, JGT, X), \
1204 INSN_3(JMP32, JLT, X), \
1205 INSN_3(JMP32, JGE, X), \
1206 INSN_3(JMP32, JLE, X), \
1207 INSN_3(JMP32, JSGT, X), \
1208 INSN_3(JMP32, JSLT, X), \
1209 INSN_3(JMP32, JSGE, X), \
1210 INSN_3(JMP32, JSLE, X), \
1211 INSN_3(JMP32, JSET, X), \
1212 /* Immediate based. */ \
1213 INSN_3(JMP32, JEQ, K), \
1214 INSN_3(JMP32, JNE, K), \
1215 INSN_3(JMP32, JGT, K), \
1216 INSN_3(JMP32, JLT, K), \
1217 INSN_3(JMP32, JGE, K), \
1218 INSN_3(JMP32, JLE, K), \
1219 INSN_3(JMP32, JSGT, K), \
1220 INSN_3(JMP32, JSLT, K), \
1221 INSN_3(JMP32, JSGE, K), \
1222 INSN_3(JMP32, JSLE, K), \
1223 INSN_3(JMP32, JSET, K), \
1224 /* Jump instructions. */ \
1225 /* Register based. */ \
1226 INSN_3(JMP, JEQ, X), \
1227 INSN_3(JMP, JNE, X), \
1228 INSN_3(JMP, JGT, X), \
1229 INSN_3(JMP, JLT, X), \
1230 INSN_3(JMP, JGE, X), \
1231 INSN_3(JMP, JLE, X), \
1232 INSN_3(JMP, JSGT, X), \
1233 INSN_3(JMP, JSLT, X), \
1234 INSN_3(JMP, JSGE, X), \
1235 INSN_3(JMP, JSLE, X), \
1236 INSN_3(JMP, JSET, X), \
1237 /* Immediate based. */ \
1238 INSN_3(JMP, JEQ, K), \
1239 INSN_3(JMP, JNE, K), \
1240 INSN_3(JMP, JGT, K), \
1241 INSN_3(JMP, JLT, K), \
1242 INSN_3(JMP, JGE, K), \
1243 INSN_3(JMP, JLE, K), \
1244 INSN_3(JMP, JSGT, K), \
1245 INSN_3(JMP, JSLT, K), \
1246 INSN_3(JMP, JSGE, K), \
1247 INSN_3(JMP, JSLE, K), \
1248 INSN_3(JMP, JSET, K), \
1249 INSN_2(JMP, JA), \
1250 /* Store instructions. */ \
1251 /* Register based. */ \
1252 INSN_3(STX, MEM, B), \
1253 INSN_3(STX, MEM, H), \
1254 INSN_3(STX, MEM, W), \
1255 INSN_3(STX, MEM, DW), \
1256 INSN_3(STX, XADD, W), \
1257 INSN_3(STX, XADD, DW), \
1258 /* Immediate based. */ \
1259 INSN_3(ST, MEM, B), \
1260 INSN_3(ST, MEM, H), \
1261 INSN_3(ST, MEM, W), \
1262 INSN_3(ST, MEM, DW), \
1263 /* Load instructions. */ \
1264 /* Register based. */ \
1265 INSN_3(LDX, MEM, B), \
1266 INSN_3(LDX, MEM, H), \
1267 INSN_3(LDX, MEM, W), \
1268 INSN_3(LDX, MEM, DW), \
1269 /* Immediate based. */ \
1270 INSN_3(LD, IMM, DW)
1271
1272bool bpf_opcode_in_insntable(u8 code)
1273{
1274#define BPF_INSN_2_TBL(x, y) [BPF_##x | BPF_##y] = true
1275#define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1276 static const bool public_insntable[256] = {
1277 [0 ... 255] = false,
1278 /* Now overwrite non-defaults ... */
1279 BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1280 /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1281 [BPF_LD | BPF_ABS | BPF_B] = true,
1282 [BPF_LD | BPF_ABS | BPF_H] = true,
1283 [BPF_LD | BPF_ABS | BPF_W] = true,
1284 [BPF_LD | BPF_IND | BPF_B] = true,
1285 [BPF_LD | BPF_IND | BPF_H] = true,
1286 [BPF_LD | BPF_IND | BPF_W] = true,
1287 };
1288#undef BPF_INSN_3_TBL
1289#undef BPF_INSN_2_TBL
1290 return public_insntable[code];
1291}
1292
1293#ifndef CONFIG_BPF_JIT_ALWAYS_ON
1294/**
1295 * __bpf_prog_run - run eBPF program on a given context
1296 * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1297 * @insn: is the array of eBPF instructions
1298 * @stack: is the eBPF storage stack
1299 *
1300 * Decode and execute eBPF instructions.
1301 */
1302static u64 __no_fgcse ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack)
1303{
1304#define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y
1305#define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1306 static const void * const jumptable[256] __annotate_jump_table = {
1307 [0 ... 255] = &&default_label,
1308 /* Now overwrite non-defaults ... */
1309 BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1310 /* Non-UAPI available opcodes. */
1311 [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1312 [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1313 };
1314#undef BPF_INSN_3_LBL
1315#undef BPF_INSN_2_LBL
1316 u32 tail_call_cnt = 0;
1317
1318#define CONT ({ insn++; goto select_insn; })
1319#define CONT_JMP ({ insn++; goto select_insn; })
1320
1321select_insn:
1322 goto *jumptable[insn->code];
1323
1324 /* ALU */
1325#define ALU(OPCODE, OP) \
1326 ALU64_##OPCODE##_X: \
1327 DST = DST OP SRC; \
1328 CONT; \
1329 ALU_##OPCODE##_X: \
1330 DST = (u32) DST OP (u32) SRC; \
1331 CONT; \
1332 ALU64_##OPCODE##_K: \
1333 DST = DST OP IMM; \
1334 CONT; \
1335 ALU_##OPCODE##_K: \
1336 DST = (u32) DST OP (u32) IMM; \
1337 CONT;
1338
1339 ALU(ADD, +)
1340 ALU(SUB, -)
1341 ALU(AND, &)
1342 ALU(OR, |)
1343 ALU(LSH, <<)
1344 ALU(RSH, >>)
1345 ALU(XOR, ^)
1346 ALU(MUL, *)
1347#undef ALU
1348 ALU_NEG:
1349 DST = (u32) -DST;
1350 CONT;
1351 ALU64_NEG:
1352 DST = -DST;
1353 CONT;
1354 ALU_MOV_X:
1355 DST = (u32) SRC;
1356 CONT;
1357 ALU_MOV_K:
1358 DST = (u32) IMM;
1359 CONT;
1360 ALU64_MOV_X:
1361 DST = SRC;
1362 CONT;
1363 ALU64_MOV_K:
1364 DST = IMM;
1365 CONT;
1366 LD_IMM_DW:
1367 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1368 insn++;
1369 CONT;
1370 ALU_ARSH_X:
1371 DST = (u64) (u32) (((s32) DST) >> SRC);
1372 CONT;
1373 ALU_ARSH_K:
1374 DST = (u64) (u32) (((s32) DST) >> IMM);
1375 CONT;
1376 ALU64_ARSH_X:
1377 (*(s64 *) &DST) >>= SRC;
1378 CONT;
1379 ALU64_ARSH_K:
1380 (*(s64 *) &DST) >>= IMM;
1381 CONT;
1382 ALU64_MOD_X:
1383 div64_u64_rem(DST, SRC, &AX);
1384 DST = AX;
1385 CONT;
1386 ALU_MOD_X:
1387 AX = (u32) DST;
1388 DST = do_div(AX, (u32) SRC);
1389 CONT;
1390 ALU64_MOD_K:
1391 div64_u64_rem(DST, IMM, &AX);
1392 DST = AX;
1393 CONT;
1394 ALU_MOD_K:
1395 AX = (u32) DST;
1396 DST = do_div(AX, (u32) IMM);
1397 CONT;
1398 ALU64_DIV_X:
1399 DST = div64_u64(DST, SRC);
1400 CONT;
1401 ALU_DIV_X:
1402 AX = (u32) DST;
1403 do_div(AX, (u32) SRC);
1404 DST = (u32) AX;
1405 CONT;
1406 ALU64_DIV_K:
1407 DST = div64_u64(DST, IMM);
1408 CONT;
1409 ALU_DIV_K:
1410 AX = (u32) DST;
1411 do_div(AX, (u32) IMM);
1412 DST = (u32) AX;
1413 CONT;
1414 ALU_END_TO_BE:
1415 switch (IMM) {
1416 case 16:
1417 DST = (__force u16) cpu_to_be16(DST);
1418 break;
1419 case 32:
1420 DST = (__force u32) cpu_to_be32(DST);
1421 break;
1422 case 64:
1423 DST = (__force u64) cpu_to_be64(DST);
1424 break;
1425 }
1426 CONT;
1427 ALU_END_TO_LE:
1428 switch (IMM) {
1429 case 16:
1430 DST = (__force u16) cpu_to_le16(DST);
1431 break;
1432 case 32:
1433 DST = (__force u32) cpu_to_le32(DST);
1434 break;
1435 case 64:
1436 DST = (__force u64) cpu_to_le64(DST);
1437 break;
1438 }
1439 CONT;
1440
1441 /* CALL */
1442 JMP_CALL:
1443 /* Function call scratches BPF_R1-BPF_R5 registers,
1444 * preserves BPF_R6-BPF_R9, and stores return value
1445 * into BPF_R0.
1446 */
1447 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1448 BPF_R4, BPF_R5);
1449 CONT;
1450
1451 JMP_CALL_ARGS:
1452 BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
1453 BPF_R3, BPF_R4,
1454 BPF_R5,
1455 insn + insn->off + 1);
1456 CONT;
1457
1458 JMP_TAIL_CALL: {
1459 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1460 struct bpf_array *array = container_of(map, struct bpf_array, map);
1461 struct bpf_prog *prog;
1462 u32 index = BPF_R3;
1463
1464 if (unlikely(index >= array->map.max_entries))
1465 goto out;
1466 if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT))
1467 goto out;
1468
1469 tail_call_cnt++;
1470
1471 prog = READ_ONCE(array->ptrs[index]);
1472 if (!prog)
1473 goto out;
1474
1475 /* ARG1 at this point is guaranteed to point to CTX from
1476 * the verifier side due to the fact that the tail call is
1477 * handeled like a helper, that is, bpf_tail_call_proto,
1478 * where arg1_type is ARG_PTR_TO_CTX.
1479 */
1480 insn = prog->insnsi;
1481 goto select_insn;
1482out:
1483 CONT;
1484 }
1485 JMP_JA:
1486 insn += insn->off;
1487 CONT;
1488 JMP_EXIT:
1489 return BPF_R0;
1490 /* JMP */
1491#define COND_JMP(SIGN, OPCODE, CMP_OP) \
1492 JMP_##OPCODE##_X: \
1493 if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) { \
1494 insn += insn->off; \
1495 CONT_JMP; \
1496 } \
1497 CONT; \
1498 JMP32_##OPCODE##_X: \
1499 if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) { \
1500 insn += insn->off; \
1501 CONT_JMP; \
1502 } \
1503 CONT; \
1504 JMP_##OPCODE##_K: \
1505 if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) { \
1506 insn += insn->off; \
1507 CONT_JMP; \
1508 } \
1509 CONT; \
1510 JMP32_##OPCODE##_K: \
1511 if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) { \
1512 insn += insn->off; \
1513 CONT_JMP; \
1514 } \
1515 CONT;
1516 COND_JMP(u, JEQ, ==)
1517 COND_JMP(u, JNE, !=)
1518 COND_JMP(u, JGT, >)
1519 COND_JMP(u, JLT, <)
1520 COND_JMP(u, JGE, >=)
1521 COND_JMP(u, JLE, <=)
1522 COND_JMP(u, JSET, &)
1523 COND_JMP(s, JSGT, >)
1524 COND_JMP(s, JSLT, <)
1525 COND_JMP(s, JSGE, >=)
1526 COND_JMP(s, JSLE, <=)
1527#undef COND_JMP
1528 /* STX and ST and LDX*/
1529#define LDST(SIZEOP, SIZE) \
1530 STX_MEM_##SIZEOP: \
1531 *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \
1532 CONT; \
1533 ST_MEM_##SIZEOP: \
1534 *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \
1535 CONT; \
1536 LDX_MEM_##SIZEOP: \
1537 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \
1538 CONT;
1539
1540 LDST(B, u8)
1541 LDST(H, u16)
1542 LDST(W, u32)
1543 LDST(DW, u64)
1544#undef LDST
1545 STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
1546 atomic_add((u32) SRC, (atomic_t *)(unsigned long)
1547 (DST + insn->off));
1548 CONT;
1549 STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */
1550 atomic64_add((u64) SRC, (atomic64_t *)(unsigned long)
1551 (DST + insn->off));
1552 CONT;
1553
1554 default_label:
1555 /* If we ever reach this, we have a bug somewhere. Die hard here
1556 * instead of just returning 0; we could be somewhere in a subprog,
1557 * so execution could continue otherwise which we do /not/ want.
1558 *
1559 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
1560 */
1561 pr_warn("BPF interpreter: unknown opcode %02x\n", insn->code);
1562 BUG_ON(1);
1563 return 0;
1564}
1565
1566#define PROG_NAME(stack_size) __bpf_prog_run##stack_size
1567#define DEFINE_BPF_PROG_RUN(stack_size) \
1568static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
1569{ \
1570 u64 stack[stack_size / sizeof(u64)]; \
1571 u64 regs[MAX_BPF_EXT_REG]; \
1572\
1573 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
1574 ARG1 = (u64) (unsigned long) ctx; \
1575 return ___bpf_prog_run(regs, insn, stack); \
1576}
1577
1578#define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
1579#define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
1580static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
1581 const struct bpf_insn *insn) \
1582{ \
1583 u64 stack[stack_size / sizeof(u64)]; \
1584 u64 regs[MAX_BPF_EXT_REG]; \
1585\
1586 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
1587 BPF_R1 = r1; \
1588 BPF_R2 = r2; \
1589 BPF_R3 = r3; \
1590 BPF_R4 = r4; \
1591 BPF_R5 = r5; \
1592 return ___bpf_prog_run(regs, insn, stack); \
1593}
1594
1595#define EVAL1(FN, X) FN(X)
1596#define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
1597#define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
1598#define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
1599#define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
1600#define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
1601
1602EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
1603EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
1604EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
1605
1606EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
1607EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
1608EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
1609
1610#define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
1611
1612static unsigned int (*interpreters[])(const void *ctx,
1613 const struct bpf_insn *insn) = {
1614EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
1615EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
1616EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
1617};
1618#undef PROG_NAME_LIST
1619#define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
1620static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
1621 const struct bpf_insn *insn) = {
1622EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
1623EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
1624EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
1625};
1626#undef PROG_NAME_LIST
1627
1628void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
1629{
1630 stack_depth = max_t(u32, stack_depth, 1);
1631 insn->off = (s16) insn->imm;
1632 insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
1633 __bpf_call_base_args;
1634 insn->code = BPF_JMP | BPF_CALL_ARGS;
1635}
1636
1637#else
1638static unsigned int __bpf_prog_ret0_warn(const void *ctx,
1639 const struct bpf_insn *insn)
1640{
1641 /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
1642 * is not working properly, so warn about it!
1643 */
1644 WARN_ON_ONCE(1);
1645 return 0;
1646}
1647#endif
1648
1649bool bpf_prog_array_compatible(struct bpf_array *array,
1650 const struct bpf_prog *fp)
1651{
1652 if (fp->kprobe_override)
1653 return false;
1654
1655 if (!array->owner_prog_type) {
1656 /* There's no owner yet where we could check for
1657 * compatibility.
1658 */
1659 array->owner_prog_type = fp->type;
1660 array->owner_jited = fp->jited;
1661
1662 return true;
1663 }
1664
1665 return array->owner_prog_type == fp->type &&
1666 array->owner_jited == fp->jited;
1667}
1668
1669static int bpf_check_tail_call(const struct bpf_prog *fp)
1670{
1671 struct bpf_prog_aux *aux = fp->aux;
1672 int i;
1673
1674 for (i = 0; i < aux->used_map_cnt; i++) {
1675 struct bpf_map *map = aux->used_maps[i];
1676 struct bpf_array *array;
1677
1678 if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
1679 continue;
1680
1681 array = container_of(map, struct bpf_array, map);
1682 if (!bpf_prog_array_compatible(array, fp))
1683 return -EINVAL;
1684 }
1685
1686 return 0;
1687}
1688
1689static void bpf_prog_select_func(struct bpf_prog *fp)
1690{
1691#ifndef CONFIG_BPF_JIT_ALWAYS_ON
1692 u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
1693
1694 fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
1695#else
1696 fp->bpf_func = __bpf_prog_ret0_warn;
1697#endif
1698}
1699
1700/**
1701 * bpf_prog_select_runtime - select exec runtime for BPF program
1702 * @fp: bpf_prog populated with internal BPF program
1703 * @err: pointer to error variable
1704 *
1705 * Try to JIT eBPF program, if JIT is not available, use interpreter.
1706 * The BPF program will be executed via BPF_PROG_RUN() macro.
1707 */
1708struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
1709{
1710 /* In case of BPF to BPF calls, verifier did all the prep
1711 * work with regards to JITing, etc.
1712 */
1713 if (fp->bpf_func)
1714 goto finalize;
1715
1716 bpf_prog_select_func(fp);
1717
1718 /* eBPF JITs can rewrite the program in case constant
1719 * blinding is active. However, in case of error during
1720 * blinding, bpf_int_jit_compile() must always return a
1721 * valid program, which in this case would simply not
1722 * be JITed, but falls back to the interpreter.
1723 */
1724 if (!bpf_prog_is_dev_bound(fp->aux)) {
1725 *err = bpf_prog_alloc_jited_linfo(fp);
1726 if (*err)
1727 return fp;
1728
1729 fp = bpf_int_jit_compile(fp);
1730 if (!fp->jited) {
1731 bpf_prog_free_jited_linfo(fp);
1732#ifdef CONFIG_BPF_JIT_ALWAYS_ON
1733 *err = -ENOTSUPP;
1734 return fp;
1735#endif
1736 } else {
1737 bpf_prog_free_unused_jited_linfo(fp);
1738 }
1739 } else {
1740 *err = bpf_prog_offload_compile(fp);
1741 if (*err)
1742 return fp;
1743 }
1744
1745finalize:
1746 bpf_prog_lock_ro(fp);
1747
1748 /* The tail call compatibility check can only be done at
1749 * this late stage as we need to determine, if we deal
1750 * with JITed or non JITed program concatenations and not
1751 * all eBPF JITs might immediately support all features.
1752 */
1753 *err = bpf_check_tail_call(fp);
1754
1755 return fp;
1756}
1757EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
1758
1759static unsigned int __bpf_prog_ret1(const void *ctx,
1760 const struct bpf_insn *insn)
1761{
1762 return 1;
1763}
1764
1765static struct bpf_prog_dummy {
1766 struct bpf_prog prog;
1767} dummy_bpf_prog = {
1768 .prog = {
1769 .bpf_func = __bpf_prog_ret1,
1770 },
1771};
1772
1773/* to avoid allocating empty bpf_prog_array for cgroups that
1774 * don't have bpf program attached use one global 'empty_prog_array'
1775 * It will not be modified the caller of bpf_prog_array_alloc()
1776 * (since caller requested prog_cnt == 0)
1777 * that pointer should be 'freed' by bpf_prog_array_free()
1778 */
1779static struct {
1780 struct bpf_prog_array hdr;
1781 struct bpf_prog *null_prog;
1782} empty_prog_array = {
1783 .null_prog = NULL,
1784};
1785
1786struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
1787{
1788 if (prog_cnt)
1789 return kzalloc(sizeof(struct bpf_prog_array) +
1790 sizeof(struct bpf_prog_array_item) *
1791 (prog_cnt + 1),
1792 flags);
1793
1794 return &empty_prog_array.hdr;
1795}
1796
1797void bpf_prog_array_free(struct bpf_prog_array *progs)
1798{
1799 if (!progs || progs == &empty_prog_array.hdr)
1800 return;
1801 kfree_rcu(progs, rcu);
1802}
1803
1804int bpf_prog_array_length(struct bpf_prog_array *array)
1805{
1806 struct bpf_prog_array_item *item;
1807 u32 cnt = 0;
1808
1809 for (item = array->items; item->prog; item++)
1810 if (item->prog != &dummy_bpf_prog.prog)
1811 cnt++;
1812 return cnt;
1813}
1814
1815bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
1816{
1817 struct bpf_prog_array_item *item;
1818
1819 for (item = array->items; item->prog; item++)
1820 if (item->prog != &dummy_bpf_prog.prog)
1821 return false;
1822 return true;
1823}
1824
1825static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
1826 u32 *prog_ids,
1827 u32 request_cnt)
1828{
1829 struct bpf_prog_array_item *item;
1830 int i = 0;
1831
1832 for (item = array->items; item->prog; item++) {
1833 if (item->prog == &dummy_bpf_prog.prog)
1834 continue;
1835 prog_ids[i] = item->prog->aux->id;
1836 if (++i == request_cnt) {
1837 item++;
1838 break;
1839 }
1840 }
1841
1842 return !!(item->prog);
1843}
1844
1845int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
1846 __u32 __user *prog_ids, u32 cnt)
1847{
1848 unsigned long err = 0;
1849 bool nospc;
1850 u32 *ids;
1851
1852 /* users of this function are doing:
1853 * cnt = bpf_prog_array_length();
1854 * if (cnt > 0)
1855 * bpf_prog_array_copy_to_user(..., cnt);
1856 * so below kcalloc doesn't need extra cnt > 0 check.
1857 */
1858 ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
1859 if (!ids)
1860 return -ENOMEM;
1861 nospc = bpf_prog_array_copy_core(array, ids, cnt);
1862 err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
1863 kfree(ids);
1864 if (err)
1865 return -EFAULT;
1866 if (nospc)
1867 return -ENOSPC;
1868 return 0;
1869}
1870
1871void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
1872 struct bpf_prog *old_prog)
1873{
1874 struct bpf_prog_array_item *item;
1875
1876 for (item = array->items; item->prog; item++)
1877 if (item->prog == old_prog) {
1878 WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
1879 break;
1880 }
1881}
1882
1883int bpf_prog_array_copy(struct bpf_prog_array *old_array,
1884 struct bpf_prog *exclude_prog,
1885 struct bpf_prog *include_prog,
1886 struct bpf_prog_array **new_array)
1887{
1888 int new_prog_cnt, carry_prog_cnt = 0;
1889 struct bpf_prog_array_item *existing;
1890 struct bpf_prog_array *array;
1891 bool found_exclude = false;
1892 int new_prog_idx = 0;
1893
1894 /* Figure out how many existing progs we need to carry over to
1895 * the new array.
1896 */
1897 if (old_array) {
1898 existing = old_array->items;
1899 for (; existing->prog; existing++) {
1900 if (existing->prog == exclude_prog) {
1901 found_exclude = true;
1902 continue;
1903 }
1904 if (existing->prog != &dummy_bpf_prog.prog)
1905 carry_prog_cnt++;
1906 if (existing->prog == include_prog)
1907 return -EEXIST;
1908 }
1909 }
1910
1911 if (exclude_prog && !found_exclude)
1912 return -ENOENT;
1913
1914 /* How many progs (not NULL) will be in the new array? */
1915 new_prog_cnt = carry_prog_cnt;
1916 if (include_prog)
1917 new_prog_cnt += 1;
1918
1919 /* Do we have any prog (not NULL) in the new array? */
1920 if (!new_prog_cnt) {
1921 *new_array = NULL;
1922 return 0;
1923 }
1924
1925 /* +1 as the end of prog_array is marked with NULL */
1926 array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
1927 if (!array)
1928 return -ENOMEM;
1929
1930 /* Fill in the new prog array */
1931 if (carry_prog_cnt) {
1932 existing = old_array->items;
1933 for (; existing->prog; existing++)
1934 if (existing->prog != exclude_prog &&
1935 existing->prog != &dummy_bpf_prog.prog) {
1936 array->items[new_prog_idx++].prog =
1937 existing->prog;
1938 }
1939 }
1940 if (include_prog)
1941 array->items[new_prog_idx++].prog = include_prog;
1942 array->items[new_prog_idx].prog = NULL;
1943 *new_array = array;
1944 return 0;
1945}
1946
1947int bpf_prog_array_copy_info(struct bpf_prog_array *array,
1948 u32 *prog_ids, u32 request_cnt,
1949 u32 *prog_cnt)
1950{
1951 u32 cnt = 0;
1952
1953 if (array)
1954 cnt = bpf_prog_array_length(array);
1955
1956 *prog_cnt = cnt;
1957
1958 /* return early if user requested only program count or nothing to copy */
1959 if (!request_cnt || !cnt)
1960 return 0;
1961
1962 /* this function is called under trace/bpf_trace.c: bpf_event_mutex */
1963 return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
1964 : 0;
1965}
1966
1967static void bpf_prog_free_deferred(struct work_struct *work)
1968{
1969 struct bpf_prog_aux *aux;
1970 int i;
1971
1972 aux = container_of(work, struct bpf_prog_aux, work);
1973 if (bpf_prog_is_dev_bound(aux))
1974 bpf_prog_offload_destroy(aux->prog);
1975#ifdef CONFIG_PERF_EVENTS
1976 if (aux->prog->has_callchain_buf)
1977 put_callchain_buffers();
1978#endif
1979 for (i = 0; i < aux->func_cnt; i++)
1980 bpf_jit_free(aux->func[i]);
1981 if (aux->func_cnt) {
1982 kfree(aux->func);
1983 bpf_prog_unlock_free(aux->prog);
1984 } else {
1985 bpf_jit_free(aux->prog);
1986 }
1987}
1988
1989/* Free internal BPF program */
1990void bpf_prog_free(struct bpf_prog *fp)
1991{
1992 struct bpf_prog_aux *aux = fp->aux;
1993
1994 INIT_WORK(&aux->work, bpf_prog_free_deferred);
1995 schedule_work(&aux->work);
1996}
1997EXPORT_SYMBOL_GPL(bpf_prog_free);
1998
1999/* RNG for unpriviledged user space with separated state from prandom_u32(). */
2000static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2001
2002void bpf_user_rnd_init_once(void)
2003{
2004 prandom_init_once(&bpf_user_rnd_state);
2005}
2006
2007BPF_CALL_0(bpf_user_rnd_u32)
2008{
2009 /* Should someone ever have the rather unwise idea to use some
2010 * of the registers passed into this function, then note that
2011 * this function is called from native eBPF and classic-to-eBPF
2012 * transformations. Register assignments from both sides are
2013 * different, f.e. classic always sets fn(ctx, A, X) here.
2014 */
2015 struct rnd_state *state;
2016 u32 res;
2017
2018 state = &get_cpu_var(bpf_user_rnd_state);
2019 res = prandom_u32_state(state);
2020 put_cpu_var(bpf_user_rnd_state);
2021
2022 return res;
2023}
2024
2025/* Weak definitions of helper functions in case we don't have bpf syscall. */
2026const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2027const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2028const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2029const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2030const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2031const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2032const struct bpf_func_proto bpf_spin_lock_proto __weak;
2033const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2034
2035const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2036const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2037const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2038const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2039
2040const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2041const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2042const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2043const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2044const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2045
2046const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2047{
2048 return NULL;
2049}
2050
2051u64 __weak
2052bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2053 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2054{
2055 return -ENOTSUPP;
2056}
2057EXPORT_SYMBOL_GPL(bpf_event_output);
2058
2059/* Always built-in helper functions. */
2060const struct bpf_func_proto bpf_tail_call_proto = {
2061 .func = NULL,
2062 .gpl_only = false,
2063 .ret_type = RET_VOID,
2064 .arg1_type = ARG_PTR_TO_CTX,
2065 .arg2_type = ARG_CONST_MAP_PTR,
2066 .arg3_type = ARG_ANYTHING,
2067};
2068
2069/* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2070 * It is encouraged to implement bpf_int_jit_compile() instead, so that
2071 * eBPF and implicitly also cBPF can get JITed!
2072 */
2073struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2074{
2075 return prog;
2076}
2077
2078/* Stub for JITs that support eBPF. All cBPF code gets transformed into
2079 * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2080 */
2081void __weak bpf_jit_compile(struct bpf_prog *prog)
2082{
2083}
2084
2085bool __weak bpf_helper_changes_pkt_data(void *func)
2086{
2087 return false;
2088}
2089
2090/* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2091 * analysis code and wants explicit zero extension inserted by verifier.
2092 * Otherwise, return FALSE.
2093 */
2094bool __weak bpf_jit_needs_zext(void)
2095{
2096 return false;
2097}
2098
2099/* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
2100 * skb_copy_bits(), so provide a weak definition of it for NET-less config.
2101 */
2102int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
2103 int len)
2104{
2105 return -EFAULT;
2106}
2107
2108DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
2109EXPORT_SYMBOL(bpf_stats_enabled_key);
2110
2111/* All definitions of tracepoints related to BPF. */
2112#define CREATE_TRACE_POINTS
2113#include <linux/bpf_trace.h>
2114
2115EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
2116EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Linux Socket Filter - Kernel level socket filtering
4 *
5 * Based on the design of the Berkeley Packet Filter. The new
6 * internal format has been designed by PLUMgrid:
7 *
8 * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
9 *
10 * Authors:
11 *
12 * Jay Schulist <jschlst@samba.org>
13 * Alexei Starovoitov <ast@plumgrid.com>
14 * Daniel Borkmann <dborkman@redhat.com>
15 *
16 * Andi Kleen - Fix a few bad bugs and races.
17 * Kris Katterjohn - Added many additional checks in bpf_check_classic()
18 */
19
20#include <uapi/linux/btf.h>
21#include <linux/filter.h>
22#include <linux/skbuff.h>
23#include <linux/vmalloc.h>
24#include <linux/random.h>
25#include <linux/moduleloader.h>
26#include <linux/bpf.h>
27#include <linux/btf.h>
28#include <linux/objtool.h>
29#include <linux/rbtree_latch.h>
30#include <linux/kallsyms.h>
31#include <linux/rcupdate.h>
32#include <linux/perf_event.h>
33#include <linux/extable.h>
34#include <linux/log2.h>
35
36#include <asm/barrier.h>
37#include <asm/unaligned.h>
38
39/* Registers */
40#define BPF_R0 regs[BPF_REG_0]
41#define BPF_R1 regs[BPF_REG_1]
42#define BPF_R2 regs[BPF_REG_2]
43#define BPF_R3 regs[BPF_REG_3]
44#define BPF_R4 regs[BPF_REG_4]
45#define BPF_R5 regs[BPF_REG_5]
46#define BPF_R6 regs[BPF_REG_6]
47#define BPF_R7 regs[BPF_REG_7]
48#define BPF_R8 regs[BPF_REG_8]
49#define BPF_R9 regs[BPF_REG_9]
50#define BPF_R10 regs[BPF_REG_10]
51
52/* Named registers */
53#define DST regs[insn->dst_reg]
54#define SRC regs[insn->src_reg]
55#define FP regs[BPF_REG_FP]
56#define AX regs[BPF_REG_AX]
57#define ARG1 regs[BPF_REG_ARG1]
58#define CTX regs[BPF_REG_CTX]
59#define IMM insn->imm
60
61/* No hurry in this branch
62 *
63 * Exported for the bpf jit load helper.
64 */
65void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
66{
67 u8 *ptr = NULL;
68
69 if (k >= SKF_NET_OFF)
70 ptr = skb_network_header(skb) + k - SKF_NET_OFF;
71 else if (k >= SKF_LL_OFF)
72 ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
73
74 if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
75 return ptr;
76
77 return NULL;
78}
79
80struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
81{
82 gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
83 struct bpf_prog_aux *aux;
84 struct bpf_prog *fp;
85
86 size = round_up(size, PAGE_SIZE);
87 fp = __vmalloc(size, gfp_flags);
88 if (fp == NULL)
89 return NULL;
90
91 aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT | gfp_extra_flags);
92 if (aux == NULL) {
93 vfree(fp);
94 return NULL;
95 }
96 fp->active = alloc_percpu_gfp(int, GFP_KERNEL_ACCOUNT | gfp_extra_flags);
97 if (!fp->active) {
98 vfree(fp);
99 kfree(aux);
100 return NULL;
101 }
102
103 fp->pages = size / PAGE_SIZE;
104 fp->aux = aux;
105 fp->aux->prog = fp;
106 fp->jit_requested = ebpf_jit_enabled();
107
108 INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
109 mutex_init(&fp->aux->used_maps_mutex);
110 mutex_init(&fp->aux->dst_mutex);
111
112 return fp;
113}
114
115struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
116{
117 gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
118 struct bpf_prog *prog;
119 int cpu;
120
121 prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
122 if (!prog)
123 return NULL;
124
125 prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
126 if (!prog->stats) {
127 free_percpu(prog->active);
128 kfree(prog->aux);
129 vfree(prog);
130 return NULL;
131 }
132
133 for_each_possible_cpu(cpu) {
134 struct bpf_prog_stats *pstats;
135
136 pstats = per_cpu_ptr(prog->stats, cpu);
137 u64_stats_init(&pstats->syncp);
138 }
139 return prog;
140}
141EXPORT_SYMBOL_GPL(bpf_prog_alloc);
142
143int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
144{
145 if (!prog->aux->nr_linfo || !prog->jit_requested)
146 return 0;
147
148 prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
149 sizeof(*prog->aux->jited_linfo),
150 GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
151 if (!prog->aux->jited_linfo)
152 return -ENOMEM;
153
154 return 0;
155}
156
157void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
158{
159 if (prog->aux->jited_linfo &&
160 (!prog->jited || !prog->aux->jited_linfo[0])) {
161 kvfree(prog->aux->jited_linfo);
162 prog->aux->jited_linfo = NULL;
163 }
164
165 kfree(prog->aux->kfunc_tab);
166 prog->aux->kfunc_tab = NULL;
167}
168
169/* The jit engine is responsible to provide an array
170 * for insn_off to the jited_off mapping (insn_to_jit_off).
171 *
172 * The idx to this array is the insn_off. Hence, the insn_off
173 * here is relative to the prog itself instead of the main prog.
174 * This array has one entry for each xlated bpf insn.
175 *
176 * jited_off is the byte off to the last byte of the jited insn.
177 *
178 * Hence, with
179 * insn_start:
180 * The first bpf insn off of the prog. The insn off
181 * here is relative to the main prog.
182 * e.g. if prog is a subprog, insn_start > 0
183 * linfo_idx:
184 * The prog's idx to prog->aux->linfo and jited_linfo
185 *
186 * jited_linfo[linfo_idx] = prog->bpf_func
187 *
188 * For i > linfo_idx,
189 *
190 * jited_linfo[i] = prog->bpf_func +
191 * insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
192 */
193void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
194 const u32 *insn_to_jit_off)
195{
196 u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
197 const struct bpf_line_info *linfo;
198 void **jited_linfo;
199
200 if (!prog->aux->jited_linfo)
201 /* Userspace did not provide linfo */
202 return;
203
204 linfo_idx = prog->aux->linfo_idx;
205 linfo = &prog->aux->linfo[linfo_idx];
206 insn_start = linfo[0].insn_off;
207 insn_end = insn_start + prog->len;
208
209 jited_linfo = &prog->aux->jited_linfo[linfo_idx];
210 jited_linfo[0] = prog->bpf_func;
211
212 nr_linfo = prog->aux->nr_linfo - linfo_idx;
213
214 for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
215 /* The verifier ensures that linfo[i].insn_off is
216 * strictly increasing
217 */
218 jited_linfo[i] = prog->bpf_func +
219 insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
220}
221
222struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
223 gfp_t gfp_extra_flags)
224{
225 gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
226 struct bpf_prog *fp;
227 u32 pages;
228
229 size = round_up(size, PAGE_SIZE);
230 pages = size / PAGE_SIZE;
231 if (pages <= fp_old->pages)
232 return fp_old;
233
234 fp = __vmalloc(size, gfp_flags);
235 if (fp) {
236 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
237 fp->pages = pages;
238 fp->aux->prog = fp;
239
240 /* We keep fp->aux from fp_old around in the new
241 * reallocated structure.
242 */
243 fp_old->aux = NULL;
244 fp_old->stats = NULL;
245 fp_old->active = NULL;
246 __bpf_prog_free(fp_old);
247 }
248
249 return fp;
250}
251
252void __bpf_prog_free(struct bpf_prog *fp)
253{
254 if (fp->aux) {
255 mutex_destroy(&fp->aux->used_maps_mutex);
256 mutex_destroy(&fp->aux->dst_mutex);
257 kfree(fp->aux->poke_tab);
258 kfree(fp->aux);
259 }
260 free_percpu(fp->stats);
261 free_percpu(fp->active);
262 vfree(fp);
263}
264
265int bpf_prog_calc_tag(struct bpf_prog *fp)
266{
267 const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
268 u32 raw_size = bpf_prog_tag_scratch_size(fp);
269 u32 digest[SHA1_DIGEST_WORDS];
270 u32 ws[SHA1_WORKSPACE_WORDS];
271 u32 i, bsize, psize, blocks;
272 struct bpf_insn *dst;
273 bool was_ld_map;
274 u8 *raw, *todo;
275 __be32 *result;
276 __be64 *bits;
277
278 raw = vmalloc(raw_size);
279 if (!raw)
280 return -ENOMEM;
281
282 sha1_init(digest);
283 memset(ws, 0, sizeof(ws));
284
285 /* We need to take out the map fd for the digest calculation
286 * since they are unstable from user space side.
287 */
288 dst = (void *)raw;
289 for (i = 0, was_ld_map = false; i < fp->len; i++) {
290 dst[i] = fp->insnsi[i];
291 if (!was_ld_map &&
292 dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
293 (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
294 dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
295 was_ld_map = true;
296 dst[i].imm = 0;
297 } else if (was_ld_map &&
298 dst[i].code == 0 &&
299 dst[i].dst_reg == 0 &&
300 dst[i].src_reg == 0 &&
301 dst[i].off == 0) {
302 was_ld_map = false;
303 dst[i].imm = 0;
304 } else {
305 was_ld_map = false;
306 }
307 }
308
309 psize = bpf_prog_insn_size(fp);
310 memset(&raw[psize], 0, raw_size - psize);
311 raw[psize++] = 0x80;
312
313 bsize = round_up(psize, SHA1_BLOCK_SIZE);
314 blocks = bsize / SHA1_BLOCK_SIZE;
315 todo = raw;
316 if (bsize - psize >= sizeof(__be64)) {
317 bits = (__be64 *)(todo + bsize - sizeof(__be64));
318 } else {
319 bits = (__be64 *)(todo + bsize + bits_offset);
320 blocks++;
321 }
322 *bits = cpu_to_be64((psize - 1) << 3);
323
324 while (blocks--) {
325 sha1_transform(digest, todo, ws);
326 todo += SHA1_BLOCK_SIZE;
327 }
328
329 result = (__force __be32 *)digest;
330 for (i = 0; i < SHA1_DIGEST_WORDS; i++)
331 result[i] = cpu_to_be32(digest[i]);
332 memcpy(fp->tag, result, sizeof(fp->tag));
333
334 vfree(raw);
335 return 0;
336}
337
338static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
339 s32 end_new, s32 curr, const bool probe_pass)
340{
341 const s64 imm_min = S32_MIN, imm_max = S32_MAX;
342 s32 delta = end_new - end_old;
343 s64 imm = insn->imm;
344
345 if (curr < pos && curr + imm + 1 >= end_old)
346 imm += delta;
347 else if (curr >= end_new && curr + imm + 1 < end_new)
348 imm -= delta;
349 if (imm < imm_min || imm > imm_max)
350 return -ERANGE;
351 if (!probe_pass)
352 insn->imm = imm;
353 return 0;
354}
355
356static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
357 s32 end_new, s32 curr, const bool probe_pass)
358{
359 const s32 off_min = S16_MIN, off_max = S16_MAX;
360 s32 delta = end_new - end_old;
361 s32 off = insn->off;
362
363 if (curr < pos && curr + off + 1 >= end_old)
364 off += delta;
365 else if (curr >= end_new && curr + off + 1 < end_new)
366 off -= delta;
367 if (off < off_min || off > off_max)
368 return -ERANGE;
369 if (!probe_pass)
370 insn->off = off;
371 return 0;
372}
373
374static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
375 s32 end_new, const bool probe_pass)
376{
377 u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
378 struct bpf_insn *insn = prog->insnsi;
379 int ret = 0;
380
381 for (i = 0; i < insn_cnt; i++, insn++) {
382 u8 code;
383
384 /* In the probing pass we still operate on the original,
385 * unpatched image in order to check overflows before we
386 * do any other adjustments. Therefore skip the patchlet.
387 */
388 if (probe_pass && i == pos) {
389 i = end_new;
390 insn = prog->insnsi + end_old;
391 }
392 code = insn->code;
393 if ((BPF_CLASS(code) != BPF_JMP &&
394 BPF_CLASS(code) != BPF_JMP32) ||
395 BPF_OP(code) == BPF_EXIT)
396 continue;
397 /* Adjust offset of jmps if we cross patch boundaries. */
398 if (BPF_OP(code) == BPF_CALL) {
399 if (insn->src_reg != BPF_PSEUDO_CALL)
400 continue;
401 ret = bpf_adj_delta_to_imm(insn, pos, end_old,
402 end_new, i, probe_pass);
403 } else {
404 ret = bpf_adj_delta_to_off(insn, pos, end_old,
405 end_new, i, probe_pass);
406 }
407 if (ret)
408 break;
409 }
410
411 return ret;
412}
413
414static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
415{
416 struct bpf_line_info *linfo;
417 u32 i, nr_linfo;
418
419 nr_linfo = prog->aux->nr_linfo;
420 if (!nr_linfo || !delta)
421 return;
422
423 linfo = prog->aux->linfo;
424
425 for (i = 0; i < nr_linfo; i++)
426 if (off < linfo[i].insn_off)
427 break;
428
429 /* Push all off < linfo[i].insn_off by delta */
430 for (; i < nr_linfo; i++)
431 linfo[i].insn_off += delta;
432}
433
434struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
435 const struct bpf_insn *patch, u32 len)
436{
437 u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
438 const u32 cnt_max = S16_MAX;
439 struct bpf_prog *prog_adj;
440 int err;
441
442 /* Since our patchlet doesn't expand the image, we're done. */
443 if (insn_delta == 0) {
444 memcpy(prog->insnsi + off, patch, sizeof(*patch));
445 return prog;
446 }
447
448 insn_adj_cnt = prog->len + insn_delta;
449
450 /* Reject anything that would potentially let the insn->off
451 * target overflow when we have excessive program expansions.
452 * We need to probe here before we do any reallocation where
453 * we afterwards may not fail anymore.
454 */
455 if (insn_adj_cnt > cnt_max &&
456 (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
457 return ERR_PTR(err);
458
459 /* Several new instructions need to be inserted. Make room
460 * for them. Likely, there's no need for a new allocation as
461 * last page could have large enough tailroom.
462 */
463 prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
464 GFP_USER);
465 if (!prog_adj)
466 return ERR_PTR(-ENOMEM);
467
468 prog_adj->len = insn_adj_cnt;
469
470 /* Patching happens in 3 steps:
471 *
472 * 1) Move over tail of insnsi from next instruction onwards,
473 * so we can patch the single target insn with one or more
474 * new ones (patching is always from 1 to n insns, n > 0).
475 * 2) Inject new instructions at the target location.
476 * 3) Adjust branch offsets if necessary.
477 */
478 insn_rest = insn_adj_cnt - off - len;
479
480 memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
481 sizeof(*patch) * insn_rest);
482 memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
483
484 /* We are guaranteed to not fail at this point, otherwise
485 * the ship has sailed to reverse to the original state. An
486 * overflow cannot happen at this point.
487 */
488 BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
489
490 bpf_adj_linfo(prog_adj, off, insn_delta);
491
492 return prog_adj;
493}
494
495int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
496{
497 /* Branch offsets can't overflow when program is shrinking, no need
498 * to call bpf_adj_branches(..., true) here
499 */
500 memmove(prog->insnsi + off, prog->insnsi + off + cnt,
501 sizeof(struct bpf_insn) * (prog->len - off - cnt));
502 prog->len -= cnt;
503
504 return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
505}
506
507static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
508{
509 int i;
510
511 for (i = 0; i < fp->aux->func_cnt; i++)
512 bpf_prog_kallsyms_del(fp->aux->func[i]);
513}
514
515void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
516{
517 bpf_prog_kallsyms_del_subprogs(fp);
518 bpf_prog_kallsyms_del(fp);
519}
520
521#ifdef CONFIG_BPF_JIT
522/* All BPF JIT sysctl knobs here. */
523int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
524int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
525int bpf_jit_harden __read_mostly;
526long bpf_jit_limit __read_mostly;
527
528static void
529bpf_prog_ksym_set_addr(struct bpf_prog *prog)
530{
531 const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog);
532 unsigned long addr = (unsigned long)hdr;
533
534 WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
535
536 prog->aux->ksym.start = (unsigned long) prog->bpf_func;
537 prog->aux->ksym.end = addr + hdr->pages * PAGE_SIZE;
538}
539
540static void
541bpf_prog_ksym_set_name(struct bpf_prog *prog)
542{
543 char *sym = prog->aux->ksym.name;
544 const char *end = sym + KSYM_NAME_LEN;
545 const struct btf_type *type;
546 const char *func_name;
547
548 BUILD_BUG_ON(sizeof("bpf_prog_") +
549 sizeof(prog->tag) * 2 +
550 /* name has been null terminated.
551 * We should need +1 for the '_' preceding
552 * the name. However, the null character
553 * is double counted between the name and the
554 * sizeof("bpf_prog_") above, so we omit
555 * the +1 here.
556 */
557 sizeof(prog->aux->name) > KSYM_NAME_LEN);
558
559 sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
560 sym = bin2hex(sym, prog->tag, sizeof(prog->tag));
561
562 /* prog->aux->name will be ignored if full btf name is available */
563 if (prog->aux->func_info_cnt) {
564 type = btf_type_by_id(prog->aux->btf,
565 prog->aux->func_info[prog->aux->func_idx].type_id);
566 func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
567 snprintf(sym, (size_t)(end - sym), "_%s", func_name);
568 return;
569 }
570
571 if (prog->aux->name[0])
572 snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
573 else
574 *sym = 0;
575}
576
577static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
578{
579 return container_of(n, struct bpf_ksym, tnode)->start;
580}
581
582static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
583 struct latch_tree_node *b)
584{
585 return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
586}
587
588static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
589{
590 unsigned long val = (unsigned long)key;
591 const struct bpf_ksym *ksym;
592
593 ksym = container_of(n, struct bpf_ksym, tnode);
594
595 if (val < ksym->start)
596 return -1;
597 if (val >= ksym->end)
598 return 1;
599
600 return 0;
601}
602
603static const struct latch_tree_ops bpf_tree_ops = {
604 .less = bpf_tree_less,
605 .comp = bpf_tree_comp,
606};
607
608static DEFINE_SPINLOCK(bpf_lock);
609static LIST_HEAD(bpf_kallsyms);
610static struct latch_tree_root bpf_tree __cacheline_aligned;
611
612void bpf_ksym_add(struct bpf_ksym *ksym)
613{
614 spin_lock_bh(&bpf_lock);
615 WARN_ON_ONCE(!list_empty(&ksym->lnode));
616 list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
617 latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
618 spin_unlock_bh(&bpf_lock);
619}
620
621static void __bpf_ksym_del(struct bpf_ksym *ksym)
622{
623 if (list_empty(&ksym->lnode))
624 return;
625
626 latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
627 list_del_rcu(&ksym->lnode);
628}
629
630void bpf_ksym_del(struct bpf_ksym *ksym)
631{
632 spin_lock_bh(&bpf_lock);
633 __bpf_ksym_del(ksym);
634 spin_unlock_bh(&bpf_lock);
635}
636
637static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
638{
639 return fp->jited && !bpf_prog_was_classic(fp);
640}
641
642static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp)
643{
644 return list_empty(&fp->aux->ksym.lnode) ||
645 fp->aux->ksym.lnode.prev == LIST_POISON2;
646}
647
648void bpf_prog_kallsyms_add(struct bpf_prog *fp)
649{
650 if (!bpf_prog_kallsyms_candidate(fp) ||
651 !bpf_capable())
652 return;
653
654 bpf_prog_ksym_set_addr(fp);
655 bpf_prog_ksym_set_name(fp);
656 fp->aux->ksym.prog = true;
657
658 bpf_ksym_add(&fp->aux->ksym);
659}
660
661void bpf_prog_kallsyms_del(struct bpf_prog *fp)
662{
663 if (!bpf_prog_kallsyms_candidate(fp))
664 return;
665
666 bpf_ksym_del(&fp->aux->ksym);
667}
668
669static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
670{
671 struct latch_tree_node *n;
672
673 n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
674 return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
675}
676
677const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
678 unsigned long *off, char *sym)
679{
680 struct bpf_ksym *ksym;
681 char *ret = NULL;
682
683 rcu_read_lock();
684 ksym = bpf_ksym_find(addr);
685 if (ksym) {
686 unsigned long symbol_start = ksym->start;
687 unsigned long symbol_end = ksym->end;
688
689 strncpy(sym, ksym->name, KSYM_NAME_LEN);
690
691 ret = sym;
692 if (size)
693 *size = symbol_end - symbol_start;
694 if (off)
695 *off = addr - symbol_start;
696 }
697 rcu_read_unlock();
698
699 return ret;
700}
701
702bool is_bpf_text_address(unsigned long addr)
703{
704 bool ret;
705
706 rcu_read_lock();
707 ret = bpf_ksym_find(addr) != NULL;
708 rcu_read_unlock();
709
710 return ret;
711}
712
713static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
714{
715 struct bpf_ksym *ksym = bpf_ksym_find(addr);
716
717 return ksym && ksym->prog ?
718 container_of(ksym, struct bpf_prog_aux, ksym)->prog :
719 NULL;
720}
721
722const struct exception_table_entry *search_bpf_extables(unsigned long addr)
723{
724 const struct exception_table_entry *e = NULL;
725 struct bpf_prog *prog;
726
727 rcu_read_lock();
728 prog = bpf_prog_ksym_find(addr);
729 if (!prog)
730 goto out;
731 if (!prog->aux->num_exentries)
732 goto out;
733
734 e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
735out:
736 rcu_read_unlock();
737 return e;
738}
739
740int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
741 char *sym)
742{
743 struct bpf_ksym *ksym;
744 unsigned int it = 0;
745 int ret = -ERANGE;
746
747 if (!bpf_jit_kallsyms_enabled())
748 return ret;
749
750 rcu_read_lock();
751 list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
752 if (it++ != symnum)
753 continue;
754
755 strncpy(sym, ksym->name, KSYM_NAME_LEN);
756
757 *value = ksym->start;
758 *type = BPF_SYM_ELF_TYPE;
759
760 ret = 0;
761 break;
762 }
763 rcu_read_unlock();
764
765 return ret;
766}
767
768int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
769 struct bpf_jit_poke_descriptor *poke)
770{
771 struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
772 static const u32 poke_tab_max = 1024;
773 u32 slot = prog->aux->size_poke_tab;
774 u32 size = slot + 1;
775
776 if (size > poke_tab_max)
777 return -ENOSPC;
778 if (poke->tailcall_target || poke->tailcall_target_stable ||
779 poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
780 return -EINVAL;
781
782 switch (poke->reason) {
783 case BPF_POKE_REASON_TAIL_CALL:
784 if (!poke->tail_call.map)
785 return -EINVAL;
786 break;
787 default:
788 return -EINVAL;
789 }
790
791 tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
792 if (!tab)
793 return -ENOMEM;
794
795 memcpy(&tab[slot], poke, sizeof(*poke));
796 prog->aux->size_poke_tab = size;
797 prog->aux->poke_tab = tab;
798
799 return slot;
800}
801
802static atomic_long_t bpf_jit_current;
803
804/* Can be overridden by an arch's JIT compiler if it has a custom,
805 * dedicated BPF backend memory area, or if neither of the two
806 * below apply.
807 */
808u64 __weak bpf_jit_alloc_exec_limit(void)
809{
810#if defined(MODULES_VADDR)
811 return MODULES_END - MODULES_VADDR;
812#else
813 return VMALLOC_END - VMALLOC_START;
814#endif
815}
816
817static int __init bpf_jit_charge_init(void)
818{
819 /* Only used as heuristic here to derive limit. */
820 bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2,
821 PAGE_SIZE), LONG_MAX);
822 return 0;
823}
824pure_initcall(bpf_jit_charge_init);
825
826int bpf_jit_charge_modmem(u32 pages)
827{
828 if (atomic_long_add_return(pages, &bpf_jit_current) >
829 (bpf_jit_limit >> PAGE_SHIFT)) {
830 if (!bpf_capable()) {
831 atomic_long_sub(pages, &bpf_jit_current);
832 return -EPERM;
833 }
834 }
835
836 return 0;
837}
838
839void bpf_jit_uncharge_modmem(u32 pages)
840{
841 atomic_long_sub(pages, &bpf_jit_current);
842}
843
844void *__weak bpf_jit_alloc_exec(unsigned long size)
845{
846 return module_alloc(size);
847}
848
849void __weak bpf_jit_free_exec(void *addr)
850{
851 module_memfree(addr);
852}
853
854struct bpf_binary_header *
855bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
856 unsigned int alignment,
857 bpf_jit_fill_hole_t bpf_fill_ill_insns)
858{
859 struct bpf_binary_header *hdr;
860 u32 size, hole, start, pages;
861
862 WARN_ON_ONCE(!is_power_of_2(alignment) ||
863 alignment > BPF_IMAGE_ALIGNMENT);
864
865 /* Most of BPF filters are really small, but if some of them
866 * fill a page, allow at least 128 extra bytes to insert a
867 * random section of illegal instructions.
868 */
869 size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
870 pages = size / PAGE_SIZE;
871
872 if (bpf_jit_charge_modmem(pages))
873 return NULL;
874 hdr = bpf_jit_alloc_exec(size);
875 if (!hdr) {
876 bpf_jit_uncharge_modmem(pages);
877 return NULL;
878 }
879
880 /* Fill space with illegal/arch-dep instructions. */
881 bpf_fill_ill_insns(hdr, size);
882
883 hdr->pages = pages;
884 hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
885 PAGE_SIZE - sizeof(*hdr));
886 start = (get_random_int() % hole) & ~(alignment - 1);
887
888 /* Leave a random number of instructions before BPF code. */
889 *image_ptr = &hdr->image[start];
890
891 return hdr;
892}
893
894void bpf_jit_binary_free(struct bpf_binary_header *hdr)
895{
896 u32 pages = hdr->pages;
897
898 bpf_jit_free_exec(hdr);
899 bpf_jit_uncharge_modmem(pages);
900}
901
902/* This symbol is only overridden by archs that have different
903 * requirements than the usual eBPF JITs, f.e. when they only
904 * implement cBPF JIT, do not set images read-only, etc.
905 */
906void __weak bpf_jit_free(struct bpf_prog *fp)
907{
908 if (fp->jited) {
909 struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
910
911 bpf_jit_binary_free(hdr);
912
913 WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
914 }
915
916 bpf_prog_unlock_free(fp);
917}
918
919int bpf_jit_get_func_addr(const struct bpf_prog *prog,
920 const struct bpf_insn *insn, bool extra_pass,
921 u64 *func_addr, bool *func_addr_fixed)
922{
923 s16 off = insn->off;
924 s32 imm = insn->imm;
925 u8 *addr;
926
927 *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
928 if (!*func_addr_fixed) {
929 /* Place-holder address till the last pass has collected
930 * all addresses for JITed subprograms in which case we
931 * can pick them up from prog->aux.
932 */
933 if (!extra_pass)
934 addr = NULL;
935 else if (prog->aux->func &&
936 off >= 0 && off < prog->aux->func_cnt)
937 addr = (u8 *)prog->aux->func[off]->bpf_func;
938 else
939 return -EINVAL;
940 } else {
941 /* Address of a BPF helper call. Since part of the core
942 * kernel, it's always at a fixed location. __bpf_call_base
943 * and the helper with imm relative to it are both in core
944 * kernel.
945 */
946 addr = (u8 *)__bpf_call_base + imm;
947 }
948
949 *func_addr = (unsigned long)addr;
950 return 0;
951}
952
953static int bpf_jit_blind_insn(const struct bpf_insn *from,
954 const struct bpf_insn *aux,
955 struct bpf_insn *to_buff,
956 bool emit_zext)
957{
958 struct bpf_insn *to = to_buff;
959 u32 imm_rnd = get_random_int();
960 s16 off;
961
962 BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG);
963 BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
964
965 /* Constraints on AX register:
966 *
967 * AX register is inaccessible from user space. It is mapped in
968 * all JITs, and used here for constant blinding rewrites. It is
969 * typically "stateless" meaning its contents are only valid within
970 * the executed instruction, but not across several instructions.
971 * There are a few exceptions however which are further detailed
972 * below.
973 *
974 * Constant blinding is only used by JITs, not in the interpreter.
975 * The interpreter uses AX in some occasions as a local temporary
976 * register e.g. in DIV or MOD instructions.
977 *
978 * In restricted circumstances, the verifier can also use the AX
979 * register for rewrites as long as they do not interfere with
980 * the above cases!
981 */
982 if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
983 goto out;
984
985 if (from->imm == 0 &&
986 (from->code == (BPF_ALU | BPF_MOV | BPF_K) ||
987 from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
988 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
989 goto out;
990 }
991
992 switch (from->code) {
993 case BPF_ALU | BPF_ADD | BPF_K:
994 case BPF_ALU | BPF_SUB | BPF_K:
995 case BPF_ALU | BPF_AND | BPF_K:
996 case BPF_ALU | BPF_OR | BPF_K:
997 case BPF_ALU | BPF_XOR | BPF_K:
998 case BPF_ALU | BPF_MUL | BPF_K:
999 case BPF_ALU | BPF_MOV | BPF_K:
1000 case BPF_ALU | BPF_DIV | BPF_K:
1001 case BPF_ALU | BPF_MOD | BPF_K:
1002 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1003 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1004 *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
1005 break;
1006
1007 case BPF_ALU64 | BPF_ADD | BPF_K:
1008 case BPF_ALU64 | BPF_SUB | BPF_K:
1009 case BPF_ALU64 | BPF_AND | BPF_K:
1010 case BPF_ALU64 | BPF_OR | BPF_K:
1011 case BPF_ALU64 | BPF_XOR | BPF_K:
1012 case BPF_ALU64 | BPF_MUL | BPF_K:
1013 case BPF_ALU64 | BPF_MOV | BPF_K:
1014 case BPF_ALU64 | BPF_DIV | BPF_K:
1015 case BPF_ALU64 | BPF_MOD | BPF_K:
1016 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1017 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1018 *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
1019 break;
1020
1021 case BPF_JMP | BPF_JEQ | BPF_K:
1022 case BPF_JMP | BPF_JNE | BPF_K:
1023 case BPF_JMP | BPF_JGT | BPF_K:
1024 case BPF_JMP | BPF_JLT | BPF_K:
1025 case BPF_JMP | BPF_JGE | BPF_K:
1026 case BPF_JMP | BPF_JLE | BPF_K:
1027 case BPF_JMP | BPF_JSGT | BPF_K:
1028 case BPF_JMP | BPF_JSLT | BPF_K:
1029 case BPF_JMP | BPF_JSGE | BPF_K:
1030 case BPF_JMP | BPF_JSLE | BPF_K:
1031 case BPF_JMP | BPF_JSET | BPF_K:
1032 /* Accommodate for extra offset in case of a backjump. */
1033 off = from->off;
1034 if (off < 0)
1035 off -= 2;
1036 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1037 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1038 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1039 break;
1040
1041 case BPF_JMP32 | BPF_JEQ | BPF_K:
1042 case BPF_JMP32 | BPF_JNE | BPF_K:
1043 case BPF_JMP32 | BPF_JGT | BPF_K:
1044 case BPF_JMP32 | BPF_JLT | BPF_K:
1045 case BPF_JMP32 | BPF_JGE | BPF_K:
1046 case BPF_JMP32 | BPF_JLE | BPF_K:
1047 case BPF_JMP32 | BPF_JSGT | BPF_K:
1048 case BPF_JMP32 | BPF_JSLT | BPF_K:
1049 case BPF_JMP32 | BPF_JSGE | BPF_K:
1050 case BPF_JMP32 | BPF_JSLE | BPF_K:
1051 case BPF_JMP32 | BPF_JSET | BPF_K:
1052 /* Accommodate for extra offset in case of a backjump. */
1053 off = from->off;
1054 if (off < 0)
1055 off -= 2;
1056 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1057 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1058 *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1059 off);
1060 break;
1061
1062 case BPF_LD | BPF_IMM | BPF_DW:
1063 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1064 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1065 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1066 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1067 break;
1068 case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1069 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1070 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1071 if (emit_zext)
1072 *to++ = BPF_ZEXT_REG(BPF_REG_AX);
1073 *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX);
1074 break;
1075
1076 case BPF_ST | BPF_MEM | BPF_DW:
1077 case BPF_ST | BPF_MEM | BPF_W:
1078 case BPF_ST | BPF_MEM | BPF_H:
1079 case BPF_ST | BPF_MEM | BPF_B:
1080 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1081 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1082 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1083 break;
1084 }
1085out:
1086 return to - to_buff;
1087}
1088
1089static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1090 gfp_t gfp_extra_flags)
1091{
1092 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1093 struct bpf_prog *fp;
1094
1095 fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1096 if (fp != NULL) {
1097 /* aux->prog still points to the fp_other one, so
1098 * when promoting the clone to the real program,
1099 * this still needs to be adapted.
1100 */
1101 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1102 }
1103
1104 return fp;
1105}
1106
1107static void bpf_prog_clone_free(struct bpf_prog *fp)
1108{
1109 /* aux was stolen by the other clone, so we cannot free
1110 * it from this path! It will be freed eventually by the
1111 * other program on release.
1112 *
1113 * At this point, we don't need a deferred release since
1114 * clone is guaranteed to not be locked.
1115 */
1116 fp->aux = NULL;
1117 fp->stats = NULL;
1118 fp->active = NULL;
1119 __bpf_prog_free(fp);
1120}
1121
1122void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1123{
1124 /* We have to repoint aux->prog to self, as we don't
1125 * know whether fp here is the clone or the original.
1126 */
1127 fp->aux->prog = fp;
1128 bpf_prog_clone_free(fp_other);
1129}
1130
1131struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1132{
1133 struct bpf_insn insn_buff[16], aux[2];
1134 struct bpf_prog *clone, *tmp;
1135 int insn_delta, insn_cnt;
1136 struct bpf_insn *insn;
1137 int i, rewritten;
1138
1139 if (!bpf_jit_blinding_enabled(prog) || prog->blinded)
1140 return prog;
1141
1142 clone = bpf_prog_clone_create(prog, GFP_USER);
1143 if (!clone)
1144 return ERR_PTR(-ENOMEM);
1145
1146 insn_cnt = clone->len;
1147 insn = clone->insnsi;
1148
1149 for (i = 0; i < insn_cnt; i++, insn++) {
1150 /* We temporarily need to hold the original ld64 insn
1151 * so that we can still access the first part in the
1152 * second blinding run.
1153 */
1154 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1155 insn[1].code == 0)
1156 memcpy(aux, insn, sizeof(aux));
1157
1158 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1159 clone->aux->verifier_zext);
1160 if (!rewritten)
1161 continue;
1162
1163 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1164 if (IS_ERR(tmp)) {
1165 /* Patching may have repointed aux->prog during
1166 * realloc from the original one, so we need to
1167 * fix it up here on error.
1168 */
1169 bpf_jit_prog_release_other(prog, clone);
1170 return tmp;
1171 }
1172
1173 clone = tmp;
1174 insn_delta = rewritten - 1;
1175
1176 /* Walk new program and skip insns we just inserted. */
1177 insn = clone->insnsi + i + insn_delta;
1178 insn_cnt += insn_delta;
1179 i += insn_delta;
1180 }
1181
1182 clone->blinded = 1;
1183 return clone;
1184}
1185#endif /* CONFIG_BPF_JIT */
1186
1187/* Base function for offset calculation. Needs to go into .text section,
1188 * therefore keeping it non-static as well; will also be used by JITs
1189 * anyway later on, so do not let the compiler omit it. This also needs
1190 * to go into kallsyms for correlation from e.g. bpftool, so naming
1191 * must not change.
1192 */
1193noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1194{
1195 return 0;
1196}
1197EXPORT_SYMBOL_GPL(__bpf_call_base);
1198
1199/* All UAPI available opcodes. */
1200#define BPF_INSN_MAP(INSN_2, INSN_3) \
1201 /* 32 bit ALU operations. */ \
1202 /* Register based. */ \
1203 INSN_3(ALU, ADD, X), \
1204 INSN_3(ALU, SUB, X), \
1205 INSN_3(ALU, AND, X), \
1206 INSN_3(ALU, OR, X), \
1207 INSN_3(ALU, LSH, X), \
1208 INSN_3(ALU, RSH, X), \
1209 INSN_3(ALU, XOR, X), \
1210 INSN_3(ALU, MUL, X), \
1211 INSN_3(ALU, MOV, X), \
1212 INSN_3(ALU, ARSH, X), \
1213 INSN_3(ALU, DIV, X), \
1214 INSN_3(ALU, MOD, X), \
1215 INSN_2(ALU, NEG), \
1216 INSN_3(ALU, END, TO_BE), \
1217 INSN_3(ALU, END, TO_LE), \
1218 /* Immediate based. */ \
1219 INSN_3(ALU, ADD, K), \
1220 INSN_3(ALU, SUB, K), \
1221 INSN_3(ALU, AND, K), \
1222 INSN_3(ALU, OR, K), \
1223 INSN_3(ALU, LSH, K), \
1224 INSN_3(ALU, RSH, K), \
1225 INSN_3(ALU, XOR, K), \
1226 INSN_3(ALU, MUL, K), \
1227 INSN_3(ALU, MOV, K), \
1228 INSN_3(ALU, ARSH, K), \
1229 INSN_3(ALU, DIV, K), \
1230 INSN_3(ALU, MOD, K), \
1231 /* 64 bit ALU operations. */ \
1232 /* Register based. */ \
1233 INSN_3(ALU64, ADD, X), \
1234 INSN_3(ALU64, SUB, X), \
1235 INSN_3(ALU64, AND, X), \
1236 INSN_3(ALU64, OR, X), \
1237 INSN_3(ALU64, LSH, X), \
1238 INSN_3(ALU64, RSH, X), \
1239 INSN_3(ALU64, XOR, X), \
1240 INSN_3(ALU64, MUL, X), \
1241 INSN_3(ALU64, MOV, X), \
1242 INSN_3(ALU64, ARSH, X), \
1243 INSN_3(ALU64, DIV, X), \
1244 INSN_3(ALU64, MOD, X), \
1245 INSN_2(ALU64, NEG), \
1246 /* Immediate based. */ \
1247 INSN_3(ALU64, ADD, K), \
1248 INSN_3(ALU64, SUB, K), \
1249 INSN_3(ALU64, AND, K), \
1250 INSN_3(ALU64, OR, K), \
1251 INSN_3(ALU64, LSH, K), \
1252 INSN_3(ALU64, RSH, K), \
1253 INSN_3(ALU64, XOR, K), \
1254 INSN_3(ALU64, MUL, K), \
1255 INSN_3(ALU64, MOV, K), \
1256 INSN_3(ALU64, ARSH, K), \
1257 INSN_3(ALU64, DIV, K), \
1258 INSN_3(ALU64, MOD, K), \
1259 /* Call instruction. */ \
1260 INSN_2(JMP, CALL), \
1261 /* Exit instruction. */ \
1262 INSN_2(JMP, EXIT), \
1263 /* 32-bit Jump instructions. */ \
1264 /* Register based. */ \
1265 INSN_3(JMP32, JEQ, X), \
1266 INSN_3(JMP32, JNE, X), \
1267 INSN_3(JMP32, JGT, X), \
1268 INSN_3(JMP32, JLT, X), \
1269 INSN_3(JMP32, JGE, X), \
1270 INSN_3(JMP32, JLE, X), \
1271 INSN_3(JMP32, JSGT, X), \
1272 INSN_3(JMP32, JSLT, X), \
1273 INSN_3(JMP32, JSGE, X), \
1274 INSN_3(JMP32, JSLE, X), \
1275 INSN_3(JMP32, JSET, X), \
1276 /* Immediate based. */ \
1277 INSN_3(JMP32, JEQ, K), \
1278 INSN_3(JMP32, JNE, K), \
1279 INSN_3(JMP32, JGT, K), \
1280 INSN_3(JMP32, JLT, K), \
1281 INSN_3(JMP32, JGE, K), \
1282 INSN_3(JMP32, JLE, K), \
1283 INSN_3(JMP32, JSGT, K), \
1284 INSN_3(JMP32, JSLT, K), \
1285 INSN_3(JMP32, JSGE, K), \
1286 INSN_3(JMP32, JSLE, K), \
1287 INSN_3(JMP32, JSET, K), \
1288 /* Jump instructions. */ \
1289 /* Register based. */ \
1290 INSN_3(JMP, JEQ, X), \
1291 INSN_3(JMP, JNE, X), \
1292 INSN_3(JMP, JGT, X), \
1293 INSN_3(JMP, JLT, X), \
1294 INSN_3(JMP, JGE, X), \
1295 INSN_3(JMP, JLE, X), \
1296 INSN_3(JMP, JSGT, X), \
1297 INSN_3(JMP, JSLT, X), \
1298 INSN_3(JMP, JSGE, X), \
1299 INSN_3(JMP, JSLE, X), \
1300 INSN_3(JMP, JSET, X), \
1301 /* Immediate based. */ \
1302 INSN_3(JMP, JEQ, K), \
1303 INSN_3(JMP, JNE, K), \
1304 INSN_3(JMP, JGT, K), \
1305 INSN_3(JMP, JLT, K), \
1306 INSN_3(JMP, JGE, K), \
1307 INSN_3(JMP, JLE, K), \
1308 INSN_3(JMP, JSGT, K), \
1309 INSN_3(JMP, JSLT, K), \
1310 INSN_3(JMP, JSGE, K), \
1311 INSN_3(JMP, JSLE, K), \
1312 INSN_3(JMP, JSET, K), \
1313 INSN_2(JMP, JA), \
1314 /* Store instructions. */ \
1315 /* Register based. */ \
1316 INSN_3(STX, MEM, B), \
1317 INSN_3(STX, MEM, H), \
1318 INSN_3(STX, MEM, W), \
1319 INSN_3(STX, MEM, DW), \
1320 INSN_3(STX, ATOMIC, W), \
1321 INSN_3(STX, ATOMIC, DW), \
1322 /* Immediate based. */ \
1323 INSN_3(ST, MEM, B), \
1324 INSN_3(ST, MEM, H), \
1325 INSN_3(ST, MEM, W), \
1326 INSN_3(ST, MEM, DW), \
1327 /* Load instructions. */ \
1328 /* Register based. */ \
1329 INSN_3(LDX, MEM, B), \
1330 INSN_3(LDX, MEM, H), \
1331 INSN_3(LDX, MEM, W), \
1332 INSN_3(LDX, MEM, DW), \
1333 /* Immediate based. */ \
1334 INSN_3(LD, IMM, DW)
1335
1336bool bpf_opcode_in_insntable(u8 code)
1337{
1338#define BPF_INSN_2_TBL(x, y) [BPF_##x | BPF_##y] = true
1339#define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1340 static const bool public_insntable[256] = {
1341 [0 ... 255] = false,
1342 /* Now overwrite non-defaults ... */
1343 BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1344 /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1345 [BPF_LD | BPF_ABS | BPF_B] = true,
1346 [BPF_LD | BPF_ABS | BPF_H] = true,
1347 [BPF_LD | BPF_ABS | BPF_W] = true,
1348 [BPF_LD | BPF_IND | BPF_B] = true,
1349 [BPF_LD | BPF_IND | BPF_H] = true,
1350 [BPF_LD | BPF_IND | BPF_W] = true,
1351 };
1352#undef BPF_INSN_3_TBL
1353#undef BPF_INSN_2_TBL
1354 return public_insntable[code];
1355}
1356
1357#ifndef CONFIG_BPF_JIT_ALWAYS_ON
1358u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
1359{
1360 memset(dst, 0, size);
1361 return -EFAULT;
1362}
1363
1364/**
1365 * ___bpf_prog_run - run eBPF program on a given context
1366 * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1367 * @insn: is the array of eBPF instructions
1368 *
1369 * Decode and execute eBPF instructions.
1370 *
1371 * Return: whatever value is in %BPF_R0 at program exit
1372 */
1373static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1374{
1375#define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y
1376#define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1377 static const void * const jumptable[256] __annotate_jump_table = {
1378 [0 ... 255] = &&default_label,
1379 /* Now overwrite non-defaults ... */
1380 BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1381 /* Non-UAPI available opcodes. */
1382 [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1383 [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1384 [BPF_ST | BPF_NOSPEC] = &&ST_NOSPEC,
1385 [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1386 [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1387 [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1388 [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1389 };
1390#undef BPF_INSN_3_LBL
1391#undef BPF_INSN_2_LBL
1392 u32 tail_call_cnt = 0;
1393
1394#define CONT ({ insn++; goto select_insn; })
1395#define CONT_JMP ({ insn++; goto select_insn; })
1396
1397select_insn:
1398 goto *jumptable[insn->code];
1399
1400 /* Explicitly mask the register-based shift amounts with 63 or 31
1401 * to avoid undefined behavior. Normally this won't affect the
1402 * generated code, for example, in case of native 64 bit archs such
1403 * as x86-64 or arm64, the compiler is optimizing the AND away for
1404 * the interpreter. In case of JITs, each of the JIT backends compiles
1405 * the BPF shift operations to machine instructions which produce
1406 * implementation-defined results in such a case; the resulting
1407 * contents of the register may be arbitrary, but program behaviour
1408 * as a whole remains defined. In other words, in case of JIT backends,
1409 * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1410 */
1411 /* ALU (shifts) */
1412#define SHT(OPCODE, OP) \
1413 ALU64_##OPCODE##_X: \
1414 DST = DST OP (SRC & 63); \
1415 CONT; \
1416 ALU_##OPCODE##_X: \
1417 DST = (u32) DST OP ((u32) SRC & 31); \
1418 CONT; \
1419 ALU64_##OPCODE##_K: \
1420 DST = DST OP IMM; \
1421 CONT; \
1422 ALU_##OPCODE##_K: \
1423 DST = (u32) DST OP (u32) IMM; \
1424 CONT;
1425 /* ALU (rest) */
1426#define ALU(OPCODE, OP) \
1427 ALU64_##OPCODE##_X: \
1428 DST = DST OP SRC; \
1429 CONT; \
1430 ALU_##OPCODE##_X: \
1431 DST = (u32) DST OP (u32) SRC; \
1432 CONT; \
1433 ALU64_##OPCODE##_K: \
1434 DST = DST OP IMM; \
1435 CONT; \
1436 ALU_##OPCODE##_K: \
1437 DST = (u32) DST OP (u32) IMM; \
1438 CONT;
1439 ALU(ADD, +)
1440 ALU(SUB, -)
1441 ALU(AND, &)
1442 ALU(OR, |)
1443 ALU(XOR, ^)
1444 ALU(MUL, *)
1445 SHT(LSH, <<)
1446 SHT(RSH, >>)
1447#undef SHT
1448#undef ALU
1449 ALU_NEG:
1450 DST = (u32) -DST;
1451 CONT;
1452 ALU64_NEG:
1453 DST = -DST;
1454 CONT;
1455 ALU_MOV_X:
1456 DST = (u32) SRC;
1457 CONT;
1458 ALU_MOV_K:
1459 DST = (u32) IMM;
1460 CONT;
1461 ALU64_MOV_X:
1462 DST = SRC;
1463 CONT;
1464 ALU64_MOV_K:
1465 DST = IMM;
1466 CONT;
1467 LD_IMM_DW:
1468 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1469 insn++;
1470 CONT;
1471 ALU_ARSH_X:
1472 DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1473 CONT;
1474 ALU_ARSH_K:
1475 DST = (u64) (u32) (((s32) DST) >> IMM);
1476 CONT;
1477 ALU64_ARSH_X:
1478 (*(s64 *) &DST) >>= (SRC & 63);
1479 CONT;
1480 ALU64_ARSH_K:
1481 (*(s64 *) &DST) >>= IMM;
1482 CONT;
1483 ALU64_MOD_X:
1484 div64_u64_rem(DST, SRC, &AX);
1485 DST = AX;
1486 CONT;
1487 ALU_MOD_X:
1488 AX = (u32) DST;
1489 DST = do_div(AX, (u32) SRC);
1490 CONT;
1491 ALU64_MOD_K:
1492 div64_u64_rem(DST, IMM, &AX);
1493 DST = AX;
1494 CONT;
1495 ALU_MOD_K:
1496 AX = (u32) DST;
1497 DST = do_div(AX, (u32) IMM);
1498 CONT;
1499 ALU64_DIV_X:
1500 DST = div64_u64(DST, SRC);
1501 CONT;
1502 ALU_DIV_X:
1503 AX = (u32) DST;
1504 do_div(AX, (u32) SRC);
1505 DST = (u32) AX;
1506 CONT;
1507 ALU64_DIV_K:
1508 DST = div64_u64(DST, IMM);
1509 CONT;
1510 ALU_DIV_K:
1511 AX = (u32) DST;
1512 do_div(AX, (u32) IMM);
1513 DST = (u32) AX;
1514 CONT;
1515 ALU_END_TO_BE:
1516 switch (IMM) {
1517 case 16:
1518 DST = (__force u16) cpu_to_be16(DST);
1519 break;
1520 case 32:
1521 DST = (__force u32) cpu_to_be32(DST);
1522 break;
1523 case 64:
1524 DST = (__force u64) cpu_to_be64(DST);
1525 break;
1526 }
1527 CONT;
1528 ALU_END_TO_LE:
1529 switch (IMM) {
1530 case 16:
1531 DST = (__force u16) cpu_to_le16(DST);
1532 break;
1533 case 32:
1534 DST = (__force u32) cpu_to_le32(DST);
1535 break;
1536 case 64:
1537 DST = (__force u64) cpu_to_le64(DST);
1538 break;
1539 }
1540 CONT;
1541
1542 /* CALL */
1543 JMP_CALL:
1544 /* Function call scratches BPF_R1-BPF_R5 registers,
1545 * preserves BPF_R6-BPF_R9, and stores return value
1546 * into BPF_R0.
1547 */
1548 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1549 BPF_R4, BPF_R5);
1550 CONT;
1551
1552 JMP_CALL_ARGS:
1553 BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
1554 BPF_R3, BPF_R4,
1555 BPF_R5,
1556 insn + insn->off + 1);
1557 CONT;
1558
1559 JMP_TAIL_CALL: {
1560 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1561 struct bpf_array *array = container_of(map, struct bpf_array, map);
1562 struct bpf_prog *prog;
1563 u32 index = BPF_R3;
1564
1565 if (unlikely(index >= array->map.max_entries))
1566 goto out;
1567 if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT))
1568 goto out;
1569
1570 tail_call_cnt++;
1571
1572 prog = READ_ONCE(array->ptrs[index]);
1573 if (!prog)
1574 goto out;
1575
1576 /* ARG1 at this point is guaranteed to point to CTX from
1577 * the verifier side due to the fact that the tail call is
1578 * handled like a helper, that is, bpf_tail_call_proto,
1579 * where arg1_type is ARG_PTR_TO_CTX.
1580 */
1581 insn = prog->insnsi;
1582 goto select_insn;
1583out:
1584 CONT;
1585 }
1586 JMP_JA:
1587 insn += insn->off;
1588 CONT;
1589 JMP_EXIT:
1590 return BPF_R0;
1591 /* JMP */
1592#define COND_JMP(SIGN, OPCODE, CMP_OP) \
1593 JMP_##OPCODE##_X: \
1594 if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) { \
1595 insn += insn->off; \
1596 CONT_JMP; \
1597 } \
1598 CONT; \
1599 JMP32_##OPCODE##_X: \
1600 if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) { \
1601 insn += insn->off; \
1602 CONT_JMP; \
1603 } \
1604 CONT; \
1605 JMP_##OPCODE##_K: \
1606 if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) { \
1607 insn += insn->off; \
1608 CONT_JMP; \
1609 } \
1610 CONT; \
1611 JMP32_##OPCODE##_K: \
1612 if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) { \
1613 insn += insn->off; \
1614 CONT_JMP; \
1615 } \
1616 CONT;
1617 COND_JMP(u, JEQ, ==)
1618 COND_JMP(u, JNE, !=)
1619 COND_JMP(u, JGT, >)
1620 COND_JMP(u, JLT, <)
1621 COND_JMP(u, JGE, >=)
1622 COND_JMP(u, JLE, <=)
1623 COND_JMP(u, JSET, &)
1624 COND_JMP(s, JSGT, >)
1625 COND_JMP(s, JSLT, <)
1626 COND_JMP(s, JSGE, >=)
1627 COND_JMP(s, JSLE, <=)
1628#undef COND_JMP
1629 /* ST, STX and LDX*/
1630 ST_NOSPEC:
1631 /* Speculation barrier for mitigating Speculative Store Bypass.
1632 * In case of arm64, we rely on the firmware mitigation as
1633 * controlled via the ssbd kernel parameter. Whenever the
1634 * mitigation is enabled, it works for all of the kernel code
1635 * with no need to provide any additional instructions here.
1636 * In case of x86, we use 'lfence' insn for mitigation. We
1637 * reuse preexisting logic from Spectre v1 mitigation that
1638 * happens to produce the required code on x86 for v4 as well.
1639 */
1640#ifdef CONFIG_X86
1641 barrier_nospec();
1642#endif
1643 CONT;
1644#define LDST(SIZEOP, SIZE) \
1645 STX_MEM_##SIZEOP: \
1646 *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \
1647 CONT; \
1648 ST_MEM_##SIZEOP: \
1649 *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \
1650 CONT; \
1651 LDX_MEM_##SIZEOP: \
1652 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \
1653 CONT;
1654
1655 LDST(B, u8)
1656 LDST(H, u16)
1657 LDST(W, u32)
1658 LDST(DW, u64)
1659#undef LDST
1660#define LDX_PROBE(SIZEOP, SIZE) \
1661 LDX_PROBE_MEM_##SIZEOP: \
1662 bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) (SRC + insn->off)); \
1663 CONT;
1664 LDX_PROBE(B, 1)
1665 LDX_PROBE(H, 2)
1666 LDX_PROBE(W, 4)
1667 LDX_PROBE(DW, 8)
1668#undef LDX_PROBE
1669
1670#define ATOMIC_ALU_OP(BOP, KOP) \
1671 case BOP: \
1672 if (BPF_SIZE(insn->code) == BPF_W) \
1673 atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
1674 (DST + insn->off)); \
1675 else \
1676 atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
1677 (DST + insn->off)); \
1678 break; \
1679 case BOP | BPF_FETCH: \
1680 if (BPF_SIZE(insn->code) == BPF_W) \
1681 SRC = (u32) atomic_fetch_##KOP( \
1682 (u32) SRC, \
1683 (atomic_t *)(unsigned long) (DST + insn->off)); \
1684 else \
1685 SRC = (u64) atomic64_fetch_##KOP( \
1686 (u64) SRC, \
1687 (atomic64_t *)(unsigned long) (DST + insn->off)); \
1688 break;
1689
1690 STX_ATOMIC_DW:
1691 STX_ATOMIC_W:
1692 switch (IMM) {
1693 ATOMIC_ALU_OP(BPF_ADD, add)
1694 ATOMIC_ALU_OP(BPF_AND, and)
1695 ATOMIC_ALU_OP(BPF_OR, or)
1696 ATOMIC_ALU_OP(BPF_XOR, xor)
1697#undef ATOMIC_ALU_OP
1698
1699 case BPF_XCHG:
1700 if (BPF_SIZE(insn->code) == BPF_W)
1701 SRC = (u32) atomic_xchg(
1702 (atomic_t *)(unsigned long) (DST + insn->off),
1703 (u32) SRC);
1704 else
1705 SRC = (u64) atomic64_xchg(
1706 (atomic64_t *)(unsigned long) (DST + insn->off),
1707 (u64) SRC);
1708 break;
1709 case BPF_CMPXCHG:
1710 if (BPF_SIZE(insn->code) == BPF_W)
1711 BPF_R0 = (u32) atomic_cmpxchg(
1712 (atomic_t *)(unsigned long) (DST + insn->off),
1713 (u32) BPF_R0, (u32) SRC);
1714 else
1715 BPF_R0 = (u64) atomic64_cmpxchg(
1716 (atomic64_t *)(unsigned long) (DST + insn->off),
1717 (u64) BPF_R0, (u64) SRC);
1718 break;
1719
1720 default:
1721 goto default_label;
1722 }
1723 CONT;
1724
1725 default_label:
1726 /* If we ever reach this, we have a bug somewhere. Die hard here
1727 * instead of just returning 0; we could be somewhere in a subprog,
1728 * so execution could continue otherwise which we do /not/ want.
1729 *
1730 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
1731 */
1732 pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
1733 insn->code, insn->imm);
1734 BUG_ON(1);
1735 return 0;
1736}
1737
1738#define PROG_NAME(stack_size) __bpf_prog_run##stack_size
1739#define DEFINE_BPF_PROG_RUN(stack_size) \
1740static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
1741{ \
1742 u64 stack[stack_size / sizeof(u64)]; \
1743 u64 regs[MAX_BPF_EXT_REG]; \
1744\
1745 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
1746 ARG1 = (u64) (unsigned long) ctx; \
1747 return ___bpf_prog_run(regs, insn); \
1748}
1749
1750#define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
1751#define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
1752static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
1753 const struct bpf_insn *insn) \
1754{ \
1755 u64 stack[stack_size / sizeof(u64)]; \
1756 u64 regs[MAX_BPF_EXT_REG]; \
1757\
1758 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
1759 BPF_R1 = r1; \
1760 BPF_R2 = r2; \
1761 BPF_R3 = r3; \
1762 BPF_R4 = r4; \
1763 BPF_R5 = r5; \
1764 return ___bpf_prog_run(regs, insn); \
1765}
1766
1767#define EVAL1(FN, X) FN(X)
1768#define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
1769#define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
1770#define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
1771#define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
1772#define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
1773
1774EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
1775EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
1776EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
1777
1778EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
1779EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
1780EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
1781
1782#define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
1783
1784static unsigned int (*interpreters[])(const void *ctx,
1785 const struct bpf_insn *insn) = {
1786EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
1787EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
1788EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
1789};
1790#undef PROG_NAME_LIST
1791#define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
1792static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
1793 const struct bpf_insn *insn) = {
1794EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
1795EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
1796EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
1797};
1798#undef PROG_NAME_LIST
1799
1800void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
1801{
1802 stack_depth = max_t(u32, stack_depth, 1);
1803 insn->off = (s16) insn->imm;
1804 insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
1805 __bpf_call_base_args;
1806 insn->code = BPF_JMP | BPF_CALL_ARGS;
1807}
1808
1809#else
1810static unsigned int __bpf_prog_ret0_warn(const void *ctx,
1811 const struct bpf_insn *insn)
1812{
1813 /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
1814 * is not working properly, so warn about it!
1815 */
1816 WARN_ON_ONCE(1);
1817 return 0;
1818}
1819#endif
1820
1821bool bpf_prog_array_compatible(struct bpf_array *array,
1822 const struct bpf_prog *fp)
1823{
1824 if (fp->kprobe_override)
1825 return false;
1826
1827 if (!array->aux->type) {
1828 /* There's no owner yet where we could check for
1829 * compatibility.
1830 */
1831 array->aux->type = fp->type;
1832 array->aux->jited = fp->jited;
1833 return true;
1834 }
1835
1836 return array->aux->type == fp->type &&
1837 array->aux->jited == fp->jited;
1838}
1839
1840static int bpf_check_tail_call(const struct bpf_prog *fp)
1841{
1842 struct bpf_prog_aux *aux = fp->aux;
1843 int i, ret = 0;
1844
1845 mutex_lock(&aux->used_maps_mutex);
1846 for (i = 0; i < aux->used_map_cnt; i++) {
1847 struct bpf_map *map = aux->used_maps[i];
1848 struct bpf_array *array;
1849
1850 if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
1851 continue;
1852
1853 array = container_of(map, struct bpf_array, map);
1854 if (!bpf_prog_array_compatible(array, fp)) {
1855 ret = -EINVAL;
1856 goto out;
1857 }
1858 }
1859
1860out:
1861 mutex_unlock(&aux->used_maps_mutex);
1862 return ret;
1863}
1864
1865static void bpf_prog_select_func(struct bpf_prog *fp)
1866{
1867#ifndef CONFIG_BPF_JIT_ALWAYS_ON
1868 u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
1869
1870 fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
1871#else
1872 fp->bpf_func = __bpf_prog_ret0_warn;
1873#endif
1874}
1875
1876/**
1877 * bpf_prog_select_runtime - select exec runtime for BPF program
1878 * @fp: bpf_prog populated with internal BPF program
1879 * @err: pointer to error variable
1880 *
1881 * Try to JIT eBPF program, if JIT is not available, use interpreter.
1882 * The BPF program will be executed via BPF_PROG_RUN() macro.
1883 *
1884 * Return: the &fp argument along with &err set to 0 for success or
1885 * a negative errno code on failure
1886 */
1887struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
1888{
1889 /* In case of BPF to BPF calls, verifier did all the prep
1890 * work with regards to JITing, etc.
1891 */
1892 bool jit_needed = false;
1893
1894 if (fp->bpf_func)
1895 goto finalize;
1896
1897 if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
1898 bpf_prog_has_kfunc_call(fp))
1899 jit_needed = true;
1900
1901 bpf_prog_select_func(fp);
1902
1903 /* eBPF JITs can rewrite the program in case constant
1904 * blinding is active. However, in case of error during
1905 * blinding, bpf_int_jit_compile() must always return a
1906 * valid program, which in this case would simply not
1907 * be JITed, but falls back to the interpreter.
1908 */
1909 if (!bpf_prog_is_dev_bound(fp->aux)) {
1910 *err = bpf_prog_alloc_jited_linfo(fp);
1911 if (*err)
1912 return fp;
1913
1914 fp = bpf_int_jit_compile(fp);
1915 bpf_prog_jit_attempt_done(fp);
1916 if (!fp->jited && jit_needed) {
1917 *err = -ENOTSUPP;
1918 return fp;
1919 }
1920 } else {
1921 *err = bpf_prog_offload_compile(fp);
1922 if (*err)
1923 return fp;
1924 }
1925
1926finalize:
1927 bpf_prog_lock_ro(fp);
1928
1929 /* The tail call compatibility check can only be done at
1930 * this late stage as we need to determine, if we deal
1931 * with JITed or non JITed program concatenations and not
1932 * all eBPF JITs might immediately support all features.
1933 */
1934 *err = bpf_check_tail_call(fp);
1935
1936 return fp;
1937}
1938EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
1939
1940static unsigned int __bpf_prog_ret1(const void *ctx,
1941 const struct bpf_insn *insn)
1942{
1943 return 1;
1944}
1945
1946static struct bpf_prog_dummy {
1947 struct bpf_prog prog;
1948} dummy_bpf_prog = {
1949 .prog = {
1950 .bpf_func = __bpf_prog_ret1,
1951 },
1952};
1953
1954/* to avoid allocating empty bpf_prog_array for cgroups that
1955 * don't have bpf program attached use one global 'empty_prog_array'
1956 * It will not be modified the caller of bpf_prog_array_alloc()
1957 * (since caller requested prog_cnt == 0)
1958 * that pointer should be 'freed' by bpf_prog_array_free()
1959 */
1960static struct {
1961 struct bpf_prog_array hdr;
1962 struct bpf_prog *null_prog;
1963} empty_prog_array = {
1964 .null_prog = NULL,
1965};
1966
1967struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
1968{
1969 if (prog_cnt)
1970 return kzalloc(sizeof(struct bpf_prog_array) +
1971 sizeof(struct bpf_prog_array_item) *
1972 (prog_cnt + 1),
1973 flags);
1974
1975 return &empty_prog_array.hdr;
1976}
1977
1978void bpf_prog_array_free(struct bpf_prog_array *progs)
1979{
1980 if (!progs || progs == &empty_prog_array.hdr)
1981 return;
1982 kfree_rcu(progs, rcu);
1983}
1984
1985int bpf_prog_array_length(struct bpf_prog_array *array)
1986{
1987 struct bpf_prog_array_item *item;
1988 u32 cnt = 0;
1989
1990 for (item = array->items; item->prog; item++)
1991 if (item->prog != &dummy_bpf_prog.prog)
1992 cnt++;
1993 return cnt;
1994}
1995
1996bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
1997{
1998 struct bpf_prog_array_item *item;
1999
2000 for (item = array->items; item->prog; item++)
2001 if (item->prog != &dummy_bpf_prog.prog)
2002 return false;
2003 return true;
2004}
2005
2006static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2007 u32 *prog_ids,
2008 u32 request_cnt)
2009{
2010 struct bpf_prog_array_item *item;
2011 int i = 0;
2012
2013 for (item = array->items; item->prog; item++) {
2014 if (item->prog == &dummy_bpf_prog.prog)
2015 continue;
2016 prog_ids[i] = item->prog->aux->id;
2017 if (++i == request_cnt) {
2018 item++;
2019 break;
2020 }
2021 }
2022
2023 return !!(item->prog);
2024}
2025
2026int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2027 __u32 __user *prog_ids, u32 cnt)
2028{
2029 unsigned long err = 0;
2030 bool nospc;
2031 u32 *ids;
2032
2033 /* users of this function are doing:
2034 * cnt = bpf_prog_array_length();
2035 * if (cnt > 0)
2036 * bpf_prog_array_copy_to_user(..., cnt);
2037 * so below kcalloc doesn't need extra cnt > 0 check.
2038 */
2039 ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2040 if (!ids)
2041 return -ENOMEM;
2042 nospc = bpf_prog_array_copy_core(array, ids, cnt);
2043 err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2044 kfree(ids);
2045 if (err)
2046 return -EFAULT;
2047 if (nospc)
2048 return -ENOSPC;
2049 return 0;
2050}
2051
2052void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2053 struct bpf_prog *old_prog)
2054{
2055 struct bpf_prog_array_item *item;
2056
2057 for (item = array->items; item->prog; item++)
2058 if (item->prog == old_prog) {
2059 WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2060 break;
2061 }
2062}
2063
2064/**
2065 * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2066 * index into the program array with
2067 * a dummy no-op program.
2068 * @array: a bpf_prog_array
2069 * @index: the index of the program to replace
2070 *
2071 * Skips over dummy programs, by not counting them, when calculating
2072 * the position of the program to replace.
2073 *
2074 * Return:
2075 * * 0 - Success
2076 * * -EINVAL - Invalid index value. Must be a non-negative integer.
2077 * * -ENOENT - Index out of range
2078 */
2079int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2080{
2081 return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2082}
2083
2084/**
2085 * bpf_prog_array_update_at() - Updates the program at the given index
2086 * into the program array.
2087 * @array: a bpf_prog_array
2088 * @index: the index of the program to update
2089 * @prog: the program to insert into the array
2090 *
2091 * Skips over dummy programs, by not counting them, when calculating
2092 * the position of the program to update.
2093 *
2094 * Return:
2095 * * 0 - Success
2096 * * -EINVAL - Invalid index value. Must be a non-negative integer.
2097 * * -ENOENT - Index out of range
2098 */
2099int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2100 struct bpf_prog *prog)
2101{
2102 struct bpf_prog_array_item *item;
2103
2104 if (unlikely(index < 0))
2105 return -EINVAL;
2106
2107 for (item = array->items; item->prog; item++) {
2108 if (item->prog == &dummy_bpf_prog.prog)
2109 continue;
2110 if (!index) {
2111 WRITE_ONCE(item->prog, prog);
2112 return 0;
2113 }
2114 index--;
2115 }
2116 return -ENOENT;
2117}
2118
2119int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2120 struct bpf_prog *exclude_prog,
2121 struct bpf_prog *include_prog,
2122 struct bpf_prog_array **new_array)
2123{
2124 int new_prog_cnt, carry_prog_cnt = 0;
2125 struct bpf_prog_array_item *existing;
2126 struct bpf_prog_array *array;
2127 bool found_exclude = false;
2128 int new_prog_idx = 0;
2129
2130 /* Figure out how many existing progs we need to carry over to
2131 * the new array.
2132 */
2133 if (old_array) {
2134 existing = old_array->items;
2135 for (; existing->prog; existing++) {
2136 if (existing->prog == exclude_prog) {
2137 found_exclude = true;
2138 continue;
2139 }
2140 if (existing->prog != &dummy_bpf_prog.prog)
2141 carry_prog_cnt++;
2142 if (existing->prog == include_prog)
2143 return -EEXIST;
2144 }
2145 }
2146
2147 if (exclude_prog && !found_exclude)
2148 return -ENOENT;
2149
2150 /* How many progs (not NULL) will be in the new array? */
2151 new_prog_cnt = carry_prog_cnt;
2152 if (include_prog)
2153 new_prog_cnt += 1;
2154
2155 /* Do we have any prog (not NULL) in the new array? */
2156 if (!new_prog_cnt) {
2157 *new_array = NULL;
2158 return 0;
2159 }
2160
2161 /* +1 as the end of prog_array is marked with NULL */
2162 array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2163 if (!array)
2164 return -ENOMEM;
2165
2166 /* Fill in the new prog array */
2167 if (carry_prog_cnt) {
2168 existing = old_array->items;
2169 for (; existing->prog; existing++)
2170 if (existing->prog != exclude_prog &&
2171 existing->prog != &dummy_bpf_prog.prog) {
2172 array->items[new_prog_idx++].prog =
2173 existing->prog;
2174 }
2175 }
2176 if (include_prog)
2177 array->items[new_prog_idx++].prog = include_prog;
2178 array->items[new_prog_idx].prog = NULL;
2179 *new_array = array;
2180 return 0;
2181}
2182
2183int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2184 u32 *prog_ids, u32 request_cnt,
2185 u32 *prog_cnt)
2186{
2187 u32 cnt = 0;
2188
2189 if (array)
2190 cnt = bpf_prog_array_length(array);
2191
2192 *prog_cnt = cnt;
2193
2194 /* return early if user requested only program count or nothing to copy */
2195 if (!request_cnt || !cnt)
2196 return 0;
2197
2198 /* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2199 return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2200 : 0;
2201}
2202
2203void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2204 struct bpf_map **used_maps, u32 len)
2205{
2206 struct bpf_map *map;
2207 u32 i;
2208
2209 for (i = 0; i < len; i++) {
2210 map = used_maps[i];
2211 if (map->ops->map_poke_untrack)
2212 map->ops->map_poke_untrack(map, aux);
2213 bpf_map_put(map);
2214 }
2215}
2216
2217static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2218{
2219 __bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2220 kfree(aux->used_maps);
2221}
2222
2223void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
2224 struct btf_mod_pair *used_btfs, u32 len)
2225{
2226#ifdef CONFIG_BPF_SYSCALL
2227 struct btf_mod_pair *btf_mod;
2228 u32 i;
2229
2230 for (i = 0; i < len; i++) {
2231 btf_mod = &used_btfs[i];
2232 if (btf_mod->module)
2233 module_put(btf_mod->module);
2234 btf_put(btf_mod->btf);
2235 }
2236#endif
2237}
2238
2239static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2240{
2241 __bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt);
2242 kfree(aux->used_btfs);
2243}
2244
2245static void bpf_prog_free_deferred(struct work_struct *work)
2246{
2247 struct bpf_prog_aux *aux;
2248 int i;
2249
2250 aux = container_of(work, struct bpf_prog_aux, work);
2251 bpf_free_used_maps(aux);
2252 bpf_free_used_btfs(aux);
2253 if (bpf_prog_is_dev_bound(aux))
2254 bpf_prog_offload_destroy(aux->prog);
2255#ifdef CONFIG_PERF_EVENTS
2256 if (aux->prog->has_callchain_buf)
2257 put_callchain_buffers();
2258#endif
2259 if (aux->dst_trampoline)
2260 bpf_trampoline_put(aux->dst_trampoline);
2261 for (i = 0; i < aux->func_cnt; i++) {
2262 /* We can just unlink the subprog poke descriptor table as
2263 * it was originally linked to the main program and is also
2264 * released along with it.
2265 */
2266 aux->func[i]->aux->poke_tab = NULL;
2267 bpf_jit_free(aux->func[i]);
2268 }
2269 if (aux->func_cnt) {
2270 kfree(aux->func);
2271 bpf_prog_unlock_free(aux->prog);
2272 } else {
2273 bpf_jit_free(aux->prog);
2274 }
2275}
2276
2277/* Free internal BPF program */
2278void bpf_prog_free(struct bpf_prog *fp)
2279{
2280 struct bpf_prog_aux *aux = fp->aux;
2281
2282 if (aux->dst_prog)
2283 bpf_prog_put(aux->dst_prog);
2284 INIT_WORK(&aux->work, bpf_prog_free_deferred);
2285 schedule_work(&aux->work);
2286}
2287EXPORT_SYMBOL_GPL(bpf_prog_free);
2288
2289/* RNG for unpriviledged user space with separated state from prandom_u32(). */
2290static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2291
2292void bpf_user_rnd_init_once(void)
2293{
2294 prandom_init_once(&bpf_user_rnd_state);
2295}
2296
2297BPF_CALL_0(bpf_user_rnd_u32)
2298{
2299 /* Should someone ever have the rather unwise idea to use some
2300 * of the registers passed into this function, then note that
2301 * this function is called from native eBPF and classic-to-eBPF
2302 * transformations. Register assignments from both sides are
2303 * different, f.e. classic always sets fn(ctx, A, X) here.
2304 */
2305 struct rnd_state *state;
2306 u32 res;
2307
2308 state = &get_cpu_var(bpf_user_rnd_state);
2309 res = prandom_u32_state(state);
2310 put_cpu_var(bpf_user_rnd_state);
2311
2312 return res;
2313}
2314
2315BPF_CALL_0(bpf_get_raw_cpu_id)
2316{
2317 return raw_smp_processor_id();
2318}
2319
2320/* Weak definitions of helper functions in case we don't have bpf syscall. */
2321const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2322const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2323const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2324const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2325const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2326const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2327const struct bpf_func_proto bpf_spin_lock_proto __weak;
2328const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2329const struct bpf_func_proto bpf_jiffies64_proto __weak;
2330
2331const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2332const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2333const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2334const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2335const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2336const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2337
2338const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2339const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2340const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2341const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2342const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2343const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2344const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2345const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2346const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2347
2348const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2349{
2350 return NULL;
2351}
2352
2353u64 __weak
2354bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2355 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2356{
2357 return -ENOTSUPP;
2358}
2359EXPORT_SYMBOL_GPL(bpf_event_output);
2360
2361/* Always built-in helper functions. */
2362const struct bpf_func_proto bpf_tail_call_proto = {
2363 .func = NULL,
2364 .gpl_only = false,
2365 .ret_type = RET_VOID,
2366 .arg1_type = ARG_PTR_TO_CTX,
2367 .arg2_type = ARG_CONST_MAP_PTR,
2368 .arg3_type = ARG_ANYTHING,
2369};
2370
2371/* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2372 * It is encouraged to implement bpf_int_jit_compile() instead, so that
2373 * eBPF and implicitly also cBPF can get JITed!
2374 */
2375struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2376{
2377 return prog;
2378}
2379
2380/* Stub for JITs that support eBPF. All cBPF code gets transformed into
2381 * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2382 */
2383void __weak bpf_jit_compile(struct bpf_prog *prog)
2384{
2385}
2386
2387bool __weak bpf_helper_changes_pkt_data(void *func)
2388{
2389 return false;
2390}
2391
2392/* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2393 * analysis code and wants explicit zero extension inserted by verifier.
2394 * Otherwise, return FALSE.
2395 *
2396 * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2397 * you don't override this. JITs that don't want these extra insns can detect
2398 * them using insn_is_zext.
2399 */
2400bool __weak bpf_jit_needs_zext(void)
2401{
2402 return false;
2403}
2404
2405bool __weak bpf_jit_supports_kfunc_call(void)
2406{
2407 return false;
2408}
2409
2410/* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
2411 * skb_copy_bits(), so provide a weak definition of it for NET-less config.
2412 */
2413int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
2414 int len)
2415{
2416 return -EFAULT;
2417}
2418
2419int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
2420 void *addr1, void *addr2)
2421{
2422 return -ENOTSUPP;
2423}
2424
2425DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
2426EXPORT_SYMBOL(bpf_stats_enabled_key);
2427
2428/* All definitions of tracepoints related to BPF. */
2429#define CREATE_TRACE_POINTS
2430#include <linux/bpf_trace.h>
2431
2432EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
2433EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);