Loading...
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#include <linux/bpf_verifier.h>
36#include <linux/nodemask.h>
37#include <linux/nospec.h>
38#include <linux/bpf_mem_alloc.h>
39#include <linux/memcontrol.h>
40
41#include <asm/barrier.h>
42#include <asm/unaligned.h>
43
44/* Registers */
45#define BPF_R0 regs[BPF_REG_0]
46#define BPF_R1 regs[BPF_REG_1]
47#define BPF_R2 regs[BPF_REG_2]
48#define BPF_R3 regs[BPF_REG_3]
49#define BPF_R4 regs[BPF_REG_4]
50#define BPF_R5 regs[BPF_REG_5]
51#define BPF_R6 regs[BPF_REG_6]
52#define BPF_R7 regs[BPF_REG_7]
53#define BPF_R8 regs[BPF_REG_8]
54#define BPF_R9 regs[BPF_REG_9]
55#define BPF_R10 regs[BPF_REG_10]
56
57/* Named registers */
58#define DST regs[insn->dst_reg]
59#define SRC regs[insn->src_reg]
60#define FP regs[BPF_REG_FP]
61#define AX regs[BPF_REG_AX]
62#define ARG1 regs[BPF_REG_ARG1]
63#define CTX regs[BPF_REG_CTX]
64#define OFF insn->off
65#define IMM insn->imm
66
67struct bpf_mem_alloc bpf_global_ma;
68bool bpf_global_ma_set;
69
70/* No hurry in this branch
71 *
72 * Exported for the bpf jit load helper.
73 */
74void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
75{
76 u8 *ptr = NULL;
77
78 if (k >= SKF_NET_OFF) {
79 ptr = skb_network_header(skb) + k - SKF_NET_OFF;
80 } else if (k >= SKF_LL_OFF) {
81 if (unlikely(!skb_mac_header_was_set(skb)))
82 return NULL;
83 ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
84 }
85 if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
86 return ptr;
87
88 return NULL;
89}
90
91struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
92{
93 gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
94 struct bpf_prog_aux *aux;
95 struct bpf_prog *fp;
96
97 size = round_up(size, PAGE_SIZE);
98 fp = __vmalloc(size, gfp_flags);
99 if (fp == NULL)
100 return NULL;
101
102 aux = kzalloc(sizeof(*aux), bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
103 if (aux == NULL) {
104 vfree(fp);
105 return NULL;
106 }
107 fp->active = alloc_percpu_gfp(int, bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
108 if (!fp->active) {
109 vfree(fp);
110 kfree(aux);
111 return NULL;
112 }
113
114 fp->pages = size / PAGE_SIZE;
115 fp->aux = aux;
116 fp->aux->prog = fp;
117 fp->jit_requested = ebpf_jit_enabled();
118 fp->blinding_requested = bpf_jit_blinding_enabled(fp);
119#ifdef CONFIG_CGROUP_BPF
120 aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID;
121#endif
122
123 INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
124#ifdef CONFIG_FINEIBT
125 INIT_LIST_HEAD_RCU(&fp->aux->ksym_prefix.lnode);
126#endif
127 mutex_init(&fp->aux->used_maps_mutex);
128 mutex_init(&fp->aux->dst_mutex);
129
130 return fp;
131}
132
133struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
134{
135 gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
136 struct bpf_prog *prog;
137 int cpu;
138
139 prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
140 if (!prog)
141 return NULL;
142
143 prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
144 if (!prog->stats) {
145 free_percpu(prog->active);
146 kfree(prog->aux);
147 vfree(prog);
148 return NULL;
149 }
150
151 for_each_possible_cpu(cpu) {
152 struct bpf_prog_stats *pstats;
153
154 pstats = per_cpu_ptr(prog->stats, cpu);
155 u64_stats_init(&pstats->syncp);
156 }
157 return prog;
158}
159EXPORT_SYMBOL_GPL(bpf_prog_alloc);
160
161int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
162{
163 if (!prog->aux->nr_linfo || !prog->jit_requested)
164 return 0;
165
166 prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
167 sizeof(*prog->aux->jited_linfo),
168 bpf_memcg_flags(GFP_KERNEL | __GFP_NOWARN));
169 if (!prog->aux->jited_linfo)
170 return -ENOMEM;
171
172 return 0;
173}
174
175void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
176{
177 if (prog->aux->jited_linfo &&
178 (!prog->jited || !prog->aux->jited_linfo[0])) {
179 kvfree(prog->aux->jited_linfo);
180 prog->aux->jited_linfo = NULL;
181 }
182
183 kfree(prog->aux->kfunc_tab);
184 prog->aux->kfunc_tab = NULL;
185}
186
187/* The jit engine is responsible to provide an array
188 * for insn_off to the jited_off mapping (insn_to_jit_off).
189 *
190 * The idx to this array is the insn_off. Hence, the insn_off
191 * here is relative to the prog itself instead of the main prog.
192 * This array has one entry for each xlated bpf insn.
193 *
194 * jited_off is the byte off to the end of the jited insn.
195 *
196 * Hence, with
197 * insn_start:
198 * The first bpf insn off of the prog. The insn off
199 * here is relative to the main prog.
200 * e.g. if prog is a subprog, insn_start > 0
201 * linfo_idx:
202 * The prog's idx to prog->aux->linfo and jited_linfo
203 *
204 * jited_linfo[linfo_idx] = prog->bpf_func
205 *
206 * For i > linfo_idx,
207 *
208 * jited_linfo[i] = prog->bpf_func +
209 * insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
210 */
211void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
212 const u32 *insn_to_jit_off)
213{
214 u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
215 const struct bpf_line_info *linfo;
216 void **jited_linfo;
217
218 if (!prog->aux->jited_linfo || prog->aux->func_idx > prog->aux->func_cnt)
219 /* Userspace did not provide linfo */
220 return;
221
222 linfo_idx = prog->aux->linfo_idx;
223 linfo = &prog->aux->linfo[linfo_idx];
224 insn_start = linfo[0].insn_off;
225 insn_end = insn_start + prog->len;
226
227 jited_linfo = &prog->aux->jited_linfo[linfo_idx];
228 jited_linfo[0] = prog->bpf_func;
229
230 nr_linfo = prog->aux->nr_linfo - linfo_idx;
231
232 for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
233 /* The verifier ensures that linfo[i].insn_off is
234 * strictly increasing
235 */
236 jited_linfo[i] = prog->bpf_func +
237 insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
238}
239
240struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
241 gfp_t gfp_extra_flags)
242{
243 gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
244 struct bpf_prog *fp;
245 u32 pages;
246
247 size = round_up(size, PAGE_SIZE);
248 pages = size / PAGE_SIZE;
249 if (pages <= fp_old->pages)
250 return fp_old;
251
252 fp = __vmalloc(size, gfp_flags);
253 if (fp) {
254 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
255 fp->pages = pages;
256 fp->aux->prog = fp;
257
258 /* We keep fp->aux from fp_old around in the new
259 * reallocated structure.
260 */
261 fp_old->aux = NULL;
262 fp_old->stats = NULL;
263 fp_old->active = NULL;
264 __bpf_prog_free(fp_old);
265 }
266
267 return fp;
268}
269
270void __bpf_prog_free(struct bpf_prog *fp)
271{
272 if (fp->aux) {
273 mutex_destroy(&fp->aux->used_maps_mutex);
274 mutex_destroy(&fp->aux->dst_mutex);
275 kfree(fp->aux->poke_tab);
276 kfree(fp->aux);
277 }
278 free_percpu(fp->stats);
279 free_percpu(fp->active);
280 vfree(fp);
281}
282
283int bpf_prog_calc_tag(struct bpf_prog *fp)
284{
285 const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
286 u32 raw_size = bpf_prog_tag_scratch_size(fp);
287 u32 digest[SHA1_DIGEST_WORDS];
288 u32 ws[SHA1_WORKSPACE_WORDS];
289 u32 i, bsize, psize, blocks;
290 struct bpf_insn *dst;
291 bool was_ld_map;
292 u8 *raw, *todo;
293 __be32 *result;
294 __be64 *bits;
295
296 raw = vmalloc(raw_size);
297 if (!raw)
298 return -ENOMEM;
299
300 sha1_init(digest);
301 memset(ws, 0, sizeof(ws));
302
303 /* We need to take out the map fd for the digest calculation
304 * since they are unstable from user space side.
305 */
306 dst = (void *)raw;
307 for (i = 0, was_ld_map = false; i < fp->len; i++) {
308 dst[i] = fp->insnsi[i];
309 if (!was_ld_map &&
310 dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
311 (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
312 dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
313 was_ld_map = true;
314 dst[i].imm = 0;
315 } else if (was_ld_map &&
316 dst[i].code == 0 &&
317 dst[i].dst_reg == 0 &&
318 dst[i].src_reg == 0 &&
319 dst[i].off == 0) {
320 was_ld_map = false;
321 dst[i].imm = 0;
322 } else {
323 was_ld_map = false;
324 }
325 }
326
327 psize = bpf_prog_insn_size(fp);
328 memset(&raw[psize], 0, raw_size - psize);
329 raw[psize++] = 0x80;
330
331 bsize = round_up(psize, SHA1_BLOCK_SIZE);
332 blocks = bsize / SHA1_BLOCK_SIZE;
333 todo = raw;
334 if (bsize - psize >= sizeof(__be64)) {
335 bits = (__be64 *)(todo + bsize - sizeof(__be64));
336 } else {
337 bits = (__be64 *)(todo + bsize + bits_offset);
338 blocks++;
339 }
340 *bits = cpu_to_be64((psize - 1) << 3);
341
342 while (blocks--) {
343 sha1_transform(digest, todo, ws);
344 todo += SHA1_BLOCK_SIZE;
345 }
346
347 result = (__force __be32 *)digest;
348 for (i = 0; i < SHA1_DIGEST_WORDS; i++)
349 result[i] = cpu_to_be32(digest[i]);
350 memcpy(fp->tag, result, sizeof(fp->tag));
351
352 vfree(raw);
353 return 0;
354}
355
356static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
357 s32 end_new, s32 curr, const bool probe_pass)
358{
359 const s64 imm_min = S32_MIN, imm_max = S32_MAX;
360 s32 delta = end_new - end_old;
361 s64 imm = insn->imm;
362
363 if (curr < pos && curr + imm + 1 >= end_old)
364 imm += delta;
365 else if (curr >= end_new && curr + imm + 1 < end_new)
366 imm -= delta;
367 if (imm < imm_min || imm > imm_max)
368 return -ERANGE;
369 if (!probe_pass)
370 insn->imm = imm;
371 return 0;
372}
373
374static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
375 s32 end_new, s32 curr, const bool probe_pass)
376{
377 s64 off_min, off_max, off;
378 s32 delta = end_new - end_old;
379
380 if (insn->code == (BPF_JMP32 | BPF_JA)) {
381 off = insn->imm;
382 off_min = S32_MIN;
383 off_max = S32_MAX;
384 } else {
385 off = insn->off;
386 off_min = S16_MIN;
387 off_max = S16_MAX;
388 }
389
390 if (curr < pos && curr + off + 1 >= end_old)
391 off += delta;
392 else if (curr >= end_new && curr + off + 1 < end_new)
393 off -= delta;
394 if (off < off_min || off > off_max)
395 return -ERANGE;
396 if (!probe_pass) {
397 if (insn->code == (BPF_JMP32 | BPF_JA))
398 insn->imm = off;
399 else
400 insn->off = off;
401 }
402 return 0;
403}
404
405static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
406 s32 end_new, const bool probe_pass)
407{
408 u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
409 struct bpf_insn *insn = prog->insnsi;
410 int ret = 0;
411
412 for (i = 0; i < insn_cnt; i++, insn++) {
413 u8 code;
414
415 /* In the probing pass we still operate on the original,
416 * unpatched image in order to check overflows before we
417 * do any other adjustments. Therefore skip the patchlet.
418 */
419 if (probe_pass && i == pos) {
420 i = end_new;
421 insn = prog->insnsi + end_old;
422 }
423 if (bpf_pseudo_func(insn)) {
424 ret = bpf_adj_delta_to_imm(insn, pos, end_old,
425 end_new, i, probe_pass);
426 if (ret)
427 return ret;
428 continue;
429 }
430 code = insn->code;
431 if ((BPF_CLASS(code) != BPF_JMP &&
432 BPF_CLASS(code) != BPF_JMP32) ||
433 BPF_OP(code) == BPF_EXIT)
434 continue;
435 /* Adjust offset of jmps if we cross patch boundaries. */
436 if (BPF_OP(code) == BPF_CALL) {
437 if (insn->src_reg != BPF_PSEUDO_CALL)
438 continue;
439 ret = bpf_adj_delta_to_imm(insn, pos, end_old,
440 end_new, i, probe_pass);
441 } else {
442 ret = bpf_adj_delta_to_off(insn, pos, end_old,
443 end_new, i, probe_pass);
444 }
445 if (ret)
446 break;
447 }
448
449 return ret;
450}
451
452static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
453{
454 struct bpf_line_info *linfo;
455 u32 i, nr_linfo;
456
457 nr_linfo = prog->aux->nr_linfo;
458 if (!nr_linfo || !delta)
459 return;
460
461 linfo = prog->aux->linfo;
462
463 for (i = 0; i < nr_linfo; i++)
464 if (off < linfo[i].insn_off)
465 break;
466
467 /* Push all off < linfo[i].insn_off by delta */
468 for (; i < nr_linfo; i++)
469 linfo[i].insn_off += delta;
470}
471
472struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
473 const struct bpf_insn *patch, u32 len)
474{
475 u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
476 const u32 cnt_max = S16_MAX;
477 struct bpf_prog *prog_adj;
478 int err;
479
480 /* Since our patchlet doesn't expand the image, we're done. */
481 if (insn_delta == 0) {
482 memcpy(prog->insnsi + off, patch, sizeof(*patch));
483 return prog;
484 }
485
486 insn_adj_cnt = prog->len + insn_delta;
487
488 /* Reject anything that would potentially let the insn->off
489 * target overflow when we have excessive program expansions.
490 * We need to probe here before we do any reallocation where
491 * we afterwards may not fail anymore.
492 */
493 if (insn_adj_cnt > cnt_max &&
494 (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
495 return ERR_PTR(err);
496
497 /* Several new instructions need to be inserted. Make room
498 * for them. Likely, there's no need for a new allocation as
499 * last page could have large enough tailroom.
500 */
501 prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
502 GFP_USER);
503 if (!prog_adj)
504 return ERR_PTR(-ENOMEM);
505
506 prog_adj->len = insn_adj_cnt;
507
508 /* Patching happens in 3 steps:
509 *
510 * 1) Move over tail of insnsi from next instruction onwards,
511 * so we can patch the single target insn with one or more
512 * new ones (patching is always from 1 to n insns, n > 0).
513 * 2) Inject new instructions at the target location.
514 * 3) Adjust branch offsets if necessary.
515 */
516 insn_rest = insn_adj_cnt - off - len;
517
518 memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
519 sizeof(*patch) * insn_rest);
520 memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
521
522 /* We are guaranteed to not fail at this point, otherwise
523 * the ship has sailed to reverse to the original state. An
524 * overflow cannot happen at this point.
525 */
526 BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
527
528 bpf_adj_linfo(prog_adj, off, insn_delta);
529
530 return prog_adj;
531}
532
533int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
534{
535 /* Branch offsets can't overflow when program is shrinking, no need
536 * to call bpf_adj_branches(..., true) here
537 */
538 memmove(prog->insnsi + off, prog->insnsi + off + cnt,
539 sizeof(struct bpf_insn) * (prog->len - off - cnt));
540 prog->len -= cnt;
541
542 return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
543}
544
545static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
546{
547 int i;
548
549 for (i = 0; i < fp->aux->real_func_cnt; i++)
550 bpf_prog_kallsyms_del(fp->aux->func[i]);
551}
552
553void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
554{
555 bpf_prog_kallsyms_del_subprogs(fp);
556 bpf_prog_kallsyms_del(fp);
557}
558
559#ifdef CONFIG_BPF_JIT
560/* All BPF JIT sysctl knobs here. */
561int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
562int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
563int bpf_jit_harden __read_mostly;
564long bpf_jit_limit __read_mostly;
565long bpf_jit_limit_max __read_mostly;
566
567static void
568bpf_prog_ksym_set_addr(struct bpf_prog *prog)
569{
570 WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
571
572 prog->aux->ksym.start = (unsigned long) prog->bpf_func;
573 prog->aux->ksym.end = prog->aux->ksym.start + prog->jited_len;
574}
575
576static void
577bpf_prog_ksym_set_name(struct bpf_prog *prog)
578{
579 char *sym = prog->aux->ksym.name;
580 const char *end = sym + KSYM_NAME_LEN;
581 const struct btf_type *type;
582 const char *func_name;
583
584 BUILD_BUG_ON(sizeof("bpf_prog_") +
585 sizeof(prog->tag) * 2 +
586 /* name has been null terminated.
587 * We should need +1 for the '_' preceding
588 * the name. However, the null character
589 * is double counted between the name and the
590 * sizeof("bpf_prog_") above, so we omit
591 * the +1 here.
592 */
593 sizeof(prog->aux->name) > KSYM_NAME_LEN);
594
595 sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
596 sym = bin2hex(sym, prog->tag, sizeof(prog->tag));
597
598 /* prog->aux->name will be ignored if full btf name is available */
599 if (prog->aux->func_info_cnt && prog->aux->func_idx < prog->aux->func_info_cnt) {
600 type = btf_type_by_id(prog->aux->btf,
601 prog->aux->func_info[prog->aux->func_idx].type_id);
602 func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
603 snprintf(sym, (size_t)(end - sym), "_%s", func_name);
604 return;
605 }
606
607 if (prog->aux->name[0])
608 snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
609 else
610 *sym = 0;
611}
612
613static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
614{
615 return container_of(n, struct bpf_ksym, tnode)->start;
616}
617
618static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
619 struct latch_tree_node *b)
620{
621 return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
622}
623
624static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
625{
626 unsigned long val = (unsigned long)key;
627 const struct bpf_ksym *ksym;
628
629 ksym = container_of(n, struct bpf_ksym, tnode);
630
631 if (val < ksym->start)
632 return -1;
633 /* Ensure that we detect return addresses as part of the program, when
634 * the final instruction is a call for a program part of the stack
635 * trace. Therefore, do val > ksym->end instead of val >= ksym->end.
636 */
637 if (val > ksym->end)
638 return 1;
639
640 return 0;
641}
642
643static const struct latch_tree_ops bpf_tree_ops = {
644 .less = bpf_tree_less,
645 .comp = bpf_tree_comp,
646};
647
648static DEFINE_SPINLOCK(bpf_lock);
649static LIST_HEAD(bpf_kallsyms);
650static struct latch_tree_root bpf_tree __cacheline_aligned;
651
652void bpf_ksym_add(struct bpf_ksym *ksym)
653{
654 spin_lock_bh(&bpf_lock);
655 WARN_ON_ONCE(!list_empty(&ksym->lnode));
656 list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
657 latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
658 spin_unlock_bh(&bpf_lock);
659}
660
661static void __bpf_ksym_del(struct bpf_ksym *ksym)
662{
663 if (list_empty(&ksym->lnode))
664 return;
665
666 latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
667 list_del_rcu(&ksym->lnode);
668}
669
670void bpf_ksym_del(struct bpf_ksym *ksym)
671{
672 spin_lock_bh(&bpf_lock);
673 __bpf_ksym_del(ksym);
674 spin_unlock_bh(&bpf_lock);
675}
676
677static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
678{
679 return fp->jited && !bpf_prog_was_classic(fp);
680}
681
682void bpf_prog_kallsyms_add(struct bpf_prog *fp)
683{
684 if (!bpf_prog_kallsyms_candidate(fp) ||
685 !bpf_capable())
686 return;
687
688 bpf_prog_ksym_set_addr(fp);
689 bpf_prog_ksym_set_name(fp);
690 fp->aux->ksym.prog = true;
691
692 bpf_ksym_add(&fp->aux->ksym);
693
694#ifdef CONFIG_FINEIBT
695 /*
696 * When FineIBT, code in the __cfi_foo() symbols can get executed
697 * and hence unwinder needs help.
698 */
699 if (cfi_mode != CFI_FINEIBT)
700 return;
701
702 snprintf(fp->aux->ksym_prefix.name, KSYM_NAME_LEN,
703 "__cfi_%s", fp->aux->ksym.name);
704
705 fp->aux->ksym_prefix.start = (unsigned long) fp->bpf_func - 16;
706 fp->aux->ksym_prefix.end = (unsigned long) fp->bpf_func;
707
708 bpf_ksym_add(&fp->aux->ksym_prefix);
709#endif
710}
711
712void bpf_prog_kallsyms_del(struct bpf_prog *fp)
713{
714 if (!bpf_prog_kallsyms_candidate(fp))
715 return;
716
717 bpf_ksym_del(&fp->aux->ksym);
718#ifdef CONFIG_FINEIBT
719 if (cfi_mode != CFI_FINEIBT)
720 return;
721 bpf_ksym_del(&fp->aux->ksym_prefix);
722#endif
723}
724
725static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
726{
727 struct latch_tree_node *n;
728
729 n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
730 return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
731}
732
733const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
734 unsigned long *off, char *sym)
735{
736 struct bpf_ksym *ksym;
737 char *ret = NULL;
738
739 rcu_read_lock();
740 ksym = bpf_ksym_find(addr);
741 if (ksym) {
742 unsigned long symbol_start = ksym->start;
743 unsigned long symbol_end = ksym->end;
744
745 strncpy(sym, ksym->name, KSYM_NAME_LEN);
746
747 ret = sym;
748 if (size)
749 *size = symbol_end - symbol_start;
750 if (off)
751 *off = addr - symbol_start;
752 }
753 rcu_read_unlock();
754
755 return ret;
756}
757
758bool is_bpf_text_address(unsigned long addr)
759{
760 bool ret;
761
762 rcu_read_lock();
763 ret = bpf_ksym_find(addr) != NULL;
764 rcu_read_unlock();
765
766 return ret;
767}
768
769struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
770{
771 struct bpf_ksym *ksym = bpf_ksym_find(addr);
772
773 return ksym && ksym->prog ?
774 container_of(ksym, struct bpf_prog_aux, ksym)->prog :
775 NULL;
776}
777
778const struct exception_table_entry *search_bpf_extables(unsigned long addr)
779{
780 const struct exception_table_entry *e = NULL;
781 struct bpf_prog *prog;
782
783 rcu_read_lock();
784 prog = bpf_prog_ksym_find(addr);
785 if (!prog)
786 goto out;
787 if (!prog->aux->num_exentries)
788 goto out;
789
790 e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
791out:
792 rcu_read_unlock();
793 return e;
794}
795
796int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
797 char *sym)
798{
799 struct bpf_ksym *ksym;
800 unsigned int it = 0;
801 int ret = -ERANGE;
802
803 if (!bpf_jit_kallsyms_enabled())
804 return ret;
805
806 rcu_read_lock();
807 list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
808 if (it++ != symnum)
809 continue;
810
811 strncpy(sym, ksym->name, KSYM_NAME_LEN);
812
813 *value = ksym->start;
814 *type = BPF_SYM_ELF_TYPE;
815
816 ret = 0;
817 break;
818 }
819 rcu_read_unlock();
820
821 return ret;
822}
823
824int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
825 struct bpf_jit_poke_descriptor *poke)
826{
827 struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
828 static const u32 poke_tab_max = 1024;
829 u32 slot = prog->aux->size_poke_tab;
830 u32 size = slot + 1;
831
832 if (size > poke_tab_max)
833 return -ENOSPC;
834 if (poke->tailcall_target || poke->tailcall_target_stable ||
835 poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
836 return -EINVAL;
837
838 switch (poke->reason) {
839 case BPF_POKE_REASON_TAIL_CALL:
840 if (!poke->tail_call.map)
841 return -EINVAL;
842 break;
843 default:
844 return -EINVAL;
845 }
846
847 tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
848 if (!tab)
849 return -ENOMEM;
850
851 memcpy(&tab[slot], poke, sizeof(*poke));
852 prog->aux->size_poke_tab = size;
853 prog->aux->poke_tab = tab;
854
855 return slot;
856}
857
858/*
859 * BPF program pack allocator.
860 *
861 * Most BPF programs are pretty small. Allocating a hole page for each
862 * program is sometime a waste. Many small bpf program also adds pressure
863 * to instruction TLB. To solve this issue, we introduce a BPF program pack
864 * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
865 * to host BPF programs.
866 */
867#define BPF_PROG_CHUNK_SHIFT 6
868#define BPF_PROG_CHUNK_SIZE (1 << BPF_PROG_CHUNK_SHIFT)
869#define BPF_PROG_CHUNK_MASK (~(BPF_PROG_CHUNK_SIZE - 1))
870
871struct bpf_prog_pack {
872 struct list_head list;
873 void *ptr;
874 unsigned long bitmap[];
875};
876
877void bpf_jit_fill_hole_with_zero(void *area, unsigned int size)
878{
879 memset(area, 0, size);
880}
881
882#define BPF_PROG_SIZE_TO_NBITS(size) (round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
883
884static DEFINE_MUTEX(pack_mutex);
885static LIST_HEAD(pack_list);
886
887/* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
888 * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
889 */
890#ifdef PMD_SIZE
891#define BPF_PROG_PACK_SIZE (PMD_SIZE * num_possible_nodes())
892#else
893#define BPF_PROG_PACK_SIZE PAGE_SIZE
894#endif
895
896#define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
897
898static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
899{
900 struct bpf_prog_pack *pack;
901
902 pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)),
903 GFP_KERNEL);
904 if (!pack)
905 return NULL;
906 pack->ptr = bpf_jit_alloc_exec(BPF_PROG_PACK_SIZE);
907 if (!pack->ptr) {
908 kfree(pack);
909 return NULL;
910 }
911 bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
912 bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
913 list_add_tail(&pack->list, &pack_list);
914
915 set_vm_flush_reset_perms(pack->ptr);
916 set_memory_rox((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE);
917 return pack;
918}
919
920void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
921{
922 unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
923 struct bpf_prog_pack *pack;
924 unsigned long pos;
925 void *ptr = NULL;
926
927 mutex_lock(&pack_mutex);
928 if (size > BPF_PROG_PACK_SIZE) {
929 size = round_up(size, PAGE_SIZE);
930 ptr = bpf_jit_alloc_exec(size);
931 if (ptr) {
932 bpf_fill_ill_insns(ptr, size);
933 set_vm_flush_reset_perms(ptr);
934 set_memory_rox((unsigned long)ptr, size / PAGE_SIZE);
935 }
936 goto out;
937 }
938 list_for_each_entry(pack, &pack_list, list) {
939 pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
940 nbits, 0);
941 if (pos < BPF_PROG_CHUNK_COUNT)
942 goto found_free_area;
943 }
944
945 pack = alloc_new_pack(bpf_fill_ill_insns);
946 if (!pack)
947 goto out;
948
949 pos = 0;
950
951found_free_area:
952 bitmap_set(pack->bitmap, pos, nbits);
953 ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
954
955out:
956 mutex_unlock(&pack_mutex);
957 return ptr;
958}
959
960void bpf_prog_pack_free(void *ptr, u32 size)
961{
962 struct bpf_prog_pack *pack = NULL, *tmp;
963 unsigned int nbits;
964 unsigned long pos;
965
966 mutex_lock(&pack_mutex);
967 if (size > BPF_PROG_PACK_SIZE) {
968 bpf_jit_free_exec(ptr);
969 goto out;
970 }
971
972 list_for_each_entry(tmp, &pack_list, list) {
973 if (ptr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > ptr) {
974 pack = tmp;
975 break;
976 }
977 }
978
979 if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
980 goto out;
981
982 nbits = BPF_PROG_SIZE_TO_NBITS(size);
983 pos = ((unsigned long)ptr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
984
985 WARN_ONCE(bpf_arch_text_invalidate(ptr, size),
986 "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
987
988 bitmap_clear(pack->bitmap, pos, nbits);
989 if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
990 BPF_PROG_CHUNK_COUNT, 0) == 0) {
991 list_del(&pack->list);
992 bpf_jit_free_exec(pack->ptr);
993 kfree(pack);
994 }
995out:
996 mutex_unlock(&pack_mutex);
997}
998
999static atomic_long_t bpf_jit_current;
1000
1001/* Can be overridden by an arch's JIT compiler if it has a custom,
1002 * dedicated BPF backend memory area, or if neither of the two
1003 * below apply.
1004 */
1005u64 __weak bpf_jit_alloc_exec_limit(void)
1006{
1007#if defined(MODULES_VADDR)
1008 return MODULES_END - MODULES_VADDR;
1009#else
1010 return VMALLOC_END - VMALLOC_START;
1011#endif
1012}
1013
1014static int __init bpf_jit_charge_init(void)
1015{
1016 /* Only used as heuristic here to derive limit. */
1017 bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
1018 bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 1,
1019 PAGE_SIZE), LONG_MAX);
1020 return 0;
1021}
1022pure_initcall(bpf_jit_charge_init);
1023
1024int bpf_jit_charge_modmem(u32 size)
1025{
1026 if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
1027 if (!bpf_capable()) {
1028 atomic_long_sub(size, &bpf_jit_current);
1029 return -EPERM;
1030 }
1031 }
1032
1033 return 0;
1034}
1035
1036void bpf_jit_uncharge_modmem(u32 size)
1037{
1038 atomic_long_sub(size, &bpf_jit_current);
1039}
1040
1041void *__weak bpf_jit_alloc_exec(unsigned long size)
1042{
1043 return module_alloc(size);
1044}
1045
1046void __weak bpf_jit_free_exec(void *addr)
1047{
1048 module_memfree(addr);
1049}
1050
1051struct bpf_binary_header *
1052bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1053 unsigned int alignment,
1054 bpf_jit_fill_hole_t bpf_fill_ill_insns)
1055{
1056 struct bpf_binary_header *hdr;
1057 u32 size, hole, start;
1058
1059 WARN_ON_ONCE(!is_power_of_2(alignment) ||
1060 alignment > BPF_IMAGE_ALIGNMENT);
1061
1062 /* Most of BPF filters are really small, but if some of them
1063 * fill a page, allow at least 128 extra bytes to insert a
1064 * random section of illegal instructions.
1065 */
1066 size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
1067
1068 if (bpf_jit_charge_modmem(size))
1069 return NULL;
1070 hdr = bpf_jit_alloc_exec(size);
1071 if (!hdr) {
1072 bpf_jit_uncharge_modmem(size);
1073 return NULL;
1074 }
1075
1076 /* Fill space with illegal/arch-dep instructions. */
1077 bpf_fill_ill_insns(hdr, size);
1078
1079 hdr->size = size;
1080 hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
1081 PAGE_SIZE - sizeof(*hdr));
1082 start = get_random_u32_below(hole) & ~(alignment - 1);
1083
1084 /* Leave a random number of instructions before BPF code. */
1085 *image_ptr = &hdr->image[start];
1086
1087 return hdr;
1088}
1089
1090void bpf_jit_binary_free(struct bpf_binary_header *hdr)
1091{
1092 u32 size = hdr->size;
1093
1094 bpf_jit_free_exec(hdr);
1095 bpf_jit_uncharge_modmem(size);
1096}
1097
1098/* Allocate jit binary from bpf_prog_pack allocator.
1099 * Since the allocated memory is RO+X, the JIT engine cannot write directly
1100 * to the memory. To solve this problem, a RW buffer is also allocated at
1101 * as the same time. The JIT engine should calculate offsets based on the
1102 * RO memory address, but write JITed program to the RW buffer. Once the
1103 * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
1104 * the JITed program to the RO memory.
1105 */
1106struct bpf_binary_header *
1107bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
1108 unsigned int alignment,
1109 struct bpf_binary_header **rw_header,
1110 u8 **rw_image,
1111 bpf_jit_fill_hole_t bpf_fill_ill_insns)
1112{
1113 struct bpf_binary_header *ro_header;
1114 u32 size, hole, start;
1115
1116 WARN_ON_ONCE(!is_power_of_2(alignment) ||
1117 alignment > BPF_IMAGE_ALIGNMENT);
1118
1119 /* add 16 bytes for a random section of illegal instructions */
1120 size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
1121
1122 if (bpf_jit_charge_modmem(size))
1123 return NULL;
1124 ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns);
1125 if (!ro_header) {
1126 bpf_jit_uncharge_modmem(size);
1127 return NULL;
1128 }
1129
1130 *rw_header = kvmalloc(size, GFP_KERNEL);
1131 if (!*rw_header) {
1132 bpf_prog_pack_free(ro_header, size);
1133 bpf_jit_uncharge_modmem(size);
1134 return NULL;
1135 }
1136
1137 /* Fill space with illegal/arch-dep instructions. */
1138 bpf_fill_ill_insns(*rw_header, size);
1139 (*rw_header)->size = size;
1140
1141 hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
1142 BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
1143 start = get_random_u32_below(hole) & ~(alignment - 1);
1144
1145 *image_ptr = &ro_header->image[start];
1146 *rw_image = &(*rw_header)->image[start];
1147
1148 return ro_header;
1149}
1150
1151/* Copy JITed text from rw_header to its final location, the ro_header. */
1152int bpf_jit_binary_pack_finalize(struct bpf_prog *prog,
1153 struct bpf_binary_header *ro_header,
1154 struct bpf_binary_header *rw_header)
1155{
1156 void *ptr;
1157
1158 ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
1159
1160 kvfree(rw_header);
1161
1162 if (IS_ERR(ptr)) {
1163 bpf_prog_pack_free(ro_header, ro_header->size);
1164 return PTR_ERR(ptr);
1165 }
1166 return 0;
1167}
1168
1169/* bpf_jit_binary_pack_free is called in two different scenarios:
1170 * 1) when the program is freed after;
1171 * 2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
1172 * For case 2), we need to free both the RO memory and the RW buffer.
1173 *
1174 * bpf_jit_binary_pack_free requires proper ro_header->size. However,
1175 * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
1176 * must be set with either bpf_jit_binary_pack_finalize (normal path) or
1177 * bpf_arch_text_copy (when jit fails).
1178 */
1179void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
1180 struct bpf_binary_header *rw_header)
1181{
1182 u32 size = ro_header->size;
1183
1184 bpf_prog_pack_free(ro_header, size);
1185 kvfree(rw_header);
1186 bpf_jit_uncharge_modmem(size);
1187}
1188
1189struct bpf_binary_header *
1190bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
1191{
1192 unsigned long real_start = (unsigned long)fp->bpf_func;
1193 unsigned long addr;
1194
1195 addr = real_start & BPF_PROG_CHUNK_MASK;
1196 return (void *)addr;
1197}
1198
1199static inline struct bpf_binary_header *
1200bpf_jit_binary_hdr(const struct bpf_prog *fp)
1201{
1202 unsigned long real_start = (unsigned long)fp->bpf_func;
1203 unsigned long addr;
1204
1205 addr = real_start & PAGE_MASK;
1206 return (void *)addr;
1207}
1208
1209/* This symbol is only overridden by archs that have different
1210 * requirements than the usual eBPF JITs, f.e. when they only
1211 * implement cBPF JIT, do not set images read-only, etc.
1212 */
1213void __weak bpf_jit_free(struct bpf_prog *fp)
1214{
1215 if (fp->jited) {
1216 struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
1217
1218 bpf_jit_binary_free(hdr);
1219 WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
1220 }
1221
1222 bpf_prog_unlock_free(fp);
1223}
1224
1225int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1226 const struct bpf_insn *insn, bool extra_pass,
1227 u64 *func_addr, bool *func_addr_fixed)
1228{
1229 s16 off = insn->off;
1230 s32 imm = insn->imm;
1231 u8 *addr;
1232 int err;
1233
1234 *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1235 if (!*func_addr_fixed) {
1236 /* Place-holder address till the last pass has collected
1237 * all addresses for JITed subprograms in which case we
1238 * can pick them up from prog->aux.
1239 */
1240 if (!extra_pass)
1241 addr = NULL;
1242 else if (prog->aux->func &&
1243 off >= 0 && off < prog->aux->real_func_cnt)
1244 addr = (u8 *)prog->aux->func[off]->bpf_func;
1245 else
1246 return -EINVAL;
1247 } else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL &&
1248 bpf_jit_supports_far_kfunc_call()) {
1249 err = bpf_get_kfunc_addr(prog, insn->imm, insn->off, &addr);
1250 if (err)
1251 return err;
1252 } else {
1253 /* Address of a BPF helper call. Since part of the core
1254 * kernel, it's always at a fixed location. __bpf_call_base
1255 * and the helper with imm relative to it are both in core
1256 * kernel.
1257 */
1258 addr = (u8 *)__bpf_call_base + imm;
1259 }
1260
1261 *func_addr = (unsigned long)addr;
1262 return 0;
1263}
1264
1265static int bpf_jit_blind_insn(const struct bpf_insn *from,
1266 const struct bpf_insn *aux,
1267 struct bpf_insn *to_buff,
1268 bool emit_zext)
1269{
1270 struct bpf_insn *to = to_buff;
1271 u32 imm_rnd = get_random_u32();
1272 s16 off;
1273
1274 BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG);
1275 BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
1276
1277 /* Constraints on AX register:
1278 *
1279 * AX register is inaccessible from user space. It is mapped in
1280 * all JITs, and used here for constant blinding rewrites. It is
1281 * typically "stateless" meaning its contents are only valid within
1282 * the executed instruction, but not across several instructions.
1283 * There are a few exceptions however which are further detailed
1284 * below.
1285 *
1286 * Constant blinding is only used by JITs, not in the interpreter.
1287 * The interpreter uses AX in some occasions as a local temporary
1288 * register e.g. in DIV or MOD instructions.
1289 *
1290 * In restricted circumstances, the verifier can also use the AX
1291 * register for rewrites as long as they do not interfere with
1292 * the above cases!
1293 */
1294 if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1295 goto out;
1296
1297 if (from->imm == 0 &&
1298 (from->code == (BPF_ALU | BPF_MOV | BPF_K) ||
1299 from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1300 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1301 goto out;
1302 }
1303
1304 switch (from->code) {
1305 case BPF_ALU | BPF_ADD | BPF_K:
1306 case BPF_ALU | BPF_SUB | BPF_K:
1307 case BPF_ALU | BPF_AND | BPF_K:
1308 case BPF_ALU | BPF_OR | BPF_K:
1309 case BPF_ALU | BPF_XOR | BPF_K:
1310 case BPF_ALU | BPF_MUL | BPF_K:
1311 case BPF_ALU | BPF_MOV | BPF_K:
1312 case BPF_ALU | BPF_DIV | BPF_K:
1313 case BPF_ALU | BPF_MOD | BPF_K:
1314 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1315 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1316 *to++ = BPF_ALU32_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1317 break;
1318
1319 case BPF_ALU64 | BPF_ADD | BPF_K:
1320 case BPF_ALU64 | BPF_SUB | BPF_K:
1321 case BPF_ALU64 | BPF_AND | BPF_K:
1322 case BPF_ALU64 | BPF_OR | BPF_K:
1323 case BPF_ALU64 | BPF_XOR | BPF_K:
1324 case BPF_ALU64 | BPF_MUL | BPF_K:
1325 case BPF_ALU64 | BPF_MOV | BPF_K:
1326 case BPF_ALU64 | BPF_DIV | BPF_K:
1327 case BPF_ALU64 | BPF_MOD | BPF_K:
1328 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1329 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1330 *to++ = BPF_ALU64_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1331 break;
1332
1333 case BPF_JMP | BPF_JEQ | BPF_K:
1334 case BPF_JMP | BPF_JNE | BPF_K:
1335 case BPF_JMP | BPF_JGT | BPF_K:
1336 case BPF_JMP | BPF_JLT | BPF_K:
1337 case BPF_JMP | BPF_JGE | BPF_K:
1338 case BPF_JMP | BPF_JLE | BPF_K:
1339 case BPF_JMP | BPF_JSGT | BPF_K:
1340 case BPF_JMP | BPF_JSLT | BPF_K:
1341 case BPF_JMP | BPF_JSGE | BPF_K:
1342 case BPF_JMP | BPF_JSLE | BPF_K:
1343 case BPF_JMP | BPF_JSET | BPF_K:
1344 /* Accommodate for extra offset in case of a backjump. */
1345 off = from->off;
1346 if (off < 0)
1347 off -= 2;
1348 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1349 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1350 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1351 break;
1352
1353 case BPF_JMP32 | BPF_JEQ | BPF_K:
1354 case BPF_JMP32 | BPF_JNE | BPF_K:
1355 case BPF_JMP32 | BPF_JGT | BPF_K:
1356 case BPF_JMP32 | BPF_JLT | BPF_K:
1357 case BPF_JMP32 | BPF_JGE | BPF_K:
1358 case BPF_JMP32 | BPF_JLE | BPF_K:
1359 case BPF_JMP32 | BPF_JSGT | BPF_K:
1360 case BPF_JMP32 | BPF_JSLT | BPF_K:
1361 case BPF_JMP32 | BPF_JSGE | BPF_K:
1362 case BPF_JMP32 | BPF_JSLE | BPF_K:
1363 case BPF_JMP32 | BPF_JSET | BPF_K:
1364 /* Accommodate for extra offset in case of a backjump. */
1365 off = from->off;
1366 if (off < 0)
1367 off -= 2;
1368 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1369 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1370 *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1371 off);
1372 break;
1373
1374 case BPF_LD | BPF_IMM | BPF_DW:
1375 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1376 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1377 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1378 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1379 break;
1380 case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1381 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1382 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1383 if (emit_zext)
1384 *to++ = BPF_ZEXT_REG(BPF_REG_AX);
1385 *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX);
1386 break;
1387
1388 case BPF_ST | BPF_MEM | BPF_DW:
1389 case BPF_ST | BPF_MEM | BPF_W:
1390 case BPF_ST | BPF_MEM | BPF_H:
1391 case BPF_ST | BPF_MEM | BPF_B:
1392 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1393 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1394 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1395 break;
1396 }
1397out:
1398 return to - to_buff;
1399}
1400
1401static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1402 gfp_t gfp_extra_flags)
1403{
1404 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1405 struct bpf_prog *fp;
1406
1407 fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1408 if (fp != NULL) {
1409 /* aux->prog still points to the fp_other one, so
1410 * when promoting the clone to the real program,
1411 * this still needs to be adapted.
1412 */
1413 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1414 }
1415
1416 return fp;
1417}
1418
1419static void bpf_prog_clone_free(struct bpf_prog *fp)
1420{
1421 /* aux was stolen by the other clone, so we cannot free
1422 * it from this path! It will be freed eventually by the
1423 * other program on release.
1424 *
1425 * At this point, we don't need a deferred release since
1426 * clone is guaranteed to not be locked.
1427 */
1428 fp->aux = NULL;
1429 fp->stats = NULL;
1430 fp->active = NULL;
1431 __bpf_prog_free(fp);
1432}
1433
1434void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1435{
1436 /* We have to repoint aux->prog to self, as we don't
1437 * know whether fp here is the clone or the original.
1438 */
1439 fp->aux->prog = fp;
1440 bpf_prog_clone_free(fp_other);
1441}
1442
1443struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1444{
1445 struct bpf_insn insn_buff[16], aux[2];
1446 struct bpf_prog *clone, *tmp;
1447 int insn_delta, insn_cnt;
1448 struct bpf_insn *insn;
1449 int i, rewritten;
1450
1451 if (!prog->blinding_requested || prog->blinded)
1452 return prog;
1453
1454 clone = bpf_prog_clone_create(prog, GFP_USER);
1455 if (!clone)
1456 return ERR_PTR(-ENOMEM);
1457
1458 insn_cnt = clone->len;
1459 insn = clone->insnsi;
1460
1461 for (i = 0; i < insn_cnt; i++, insn++) {
1462 if (bpf_pseudo_func(insn)) {
1463 /* ld_imm64 with an address of bpf subprog is not
1464 * a user controlled constant. Don't randomize it,
1465 * since it will conflict with jit_subprogs() logic.
1466 */
1467 insn++;
1468 i++;
1469 continue;
1470 }
1471
1472 /* We temporarily need to hold the original ld64 insn
1473 * so that we can still access the first part in the
1474 * second blinding run.
1475 */
1476 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1477 insn[1].code == 0)
1478 memcpy(aux, insn, sizeof(aux));
1479
1480 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1481 clone->aux->verifier_zext);
1482 if (!rewritten)
1483 continue;
1484
1485 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1486 if (IS_ERR(tmp)) {
1487 /* Patching may have repointed aux->prog during
1488 * realloc from the original one, so we need to
1489 * fix it up here on error.
1490 */
1491 bpf_jit_prog_release_other(prog, clone);
1492 return tmp;
1493 }
1494
1495 clone = tmp;
1496 insn_delta = rewritten - 1;
1497
1498 /* Walk new program and skip insns we just inserted. */
1499 insn = clone->insnsi + i + insn_delta;
1500 insn_cnt += insn_delta;
1501 i += insn_delta;
1502 }
1503
1504 clone->blinded = 1;
1505 return clone;
1506}
1507#endif /* CONFIG_BPF_JIT */
1508
1509/* Base function for offset calculation. Needs to go into .text section,
1510 * therefore keeping it non-static as well; will also be used by JITs
1511 * anyway later on, so do not let the compiler omit it. This also needs
1512 * to go into kallsyms for correlation from e.g. bpftool, so naming
1513 * must not change.
1514 */
1515noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1516{
1517 return 0;
1518}
1519EXPORT_SYMBOL_GPL(__bpf_call_base);
1520
1521/* All UAPI available opcodes. */
1522#define BPF_INSN_MAP(INSN_2, INSN_3) \
1523 /* 32 bit ALU operations. */ \
1524 /* Register based. */ \
1525 INSN_3(ALU, ADD, X), \
1526 INSN_3(ALU, SUB, X), \
1527 INSN_3(ALU, AND, X), \
1528 INSN_3(ALU, OR, X), \
1529 INSN_3(ALU, LSH, X), \
1530 INSN_3(ALU, RSH, X), \
1531 INSN_3(ALU, XOR, X), \
1532 INSN_3(ALU, MUL, X), \
1533 INSN_3(ALU, MOV, X), \
1534 INSN_3(ALU, ARSH, X), \
1535 INSN_3(ALU, DIV, X), \
1536 INSN_3(ALU, MOD, X), \
1537 INSN_2(ALU, NEG), \
1538 INSN_3(ALU, END, TO_BE), \
1539 INSN_3(ALU, END, TO_LE), \
1540 /* Immediate based. */ \
1541 INSN_3(ALU, ADD, K), \
1542 INSN_3(ALU, SUB, K), \
1543 INSN_3(ALU, AND, K), \
1544 INSN_3(ALU, OR, K), \
1545 INSN_3(ALU, LSH, K), \
1546 INSN_3(ALU, RSH, K), \
1547 INSN_3(ALU, XOR, K), \
1548 INSN_3(ALU, MUL, K), \
1549 INSN_3(ALU, MOV, K), \
1550 INSN_3(ALU, ARSH, K), \
1551 INSN_3(ALU, DIV, K), \
1552 INSN_3(ALU, MOD, K), \
1553 /* 64 bit ALU operations. */ \
1554 /* Register based. */ \
1555 INSN_3(ALU64, ADD, X), \
1556 INSN_3(ALU64, SUB, X), \
1557 INSN_3(ALU64, AND, X), \
1558 INSN_3(ALU64, OR, X), \
1559 INSN_3(ALU64, LSH, X), \
1560 INSN_3(ALU64, RSH, X), \
1561 INSN_3(ALU64, XOR, X), \
1562 INSN_3(ALU64, MUL, X), \
1563 INSN_3(ALU64, MOV, X), \
1564 INSN_3(ALU64, ARSH, X), \
1565 INSN_3(ALU64, DIV, X), \
1566 INSN_3(ALU64, MOD, X), \
1567 INSN_2(ALU64, NEG), \
1568 INSN_3(ALU64, END, TO_LE), \
1569 /* Immediate based. */ \
1570 INSN_3(ALU64, ADD, K), \
1571 INSN_3(ALU64, SUB, K), \
1572 INSN_3(ALU64, AND, K), \
1573 INSN_3(ALU64, OR, K), \
1574 INSN_3(ALU64, LSH, K), \
1575 INSN_3(ALU64, RSH, K), \
1576 INSN_3(ALU64, XOR, K), \
1577 INSN_3(ALU64, MUL, K), \
1578 INSN_3(ALU64, MOV, K), \
1579 INSN_3(ALU64, ARSH, K), \
1580 INSN_3(ALU64, DIV, K), \
1581 INSN_3(ALU64, MOD, K), \
1582 /* Call instruction. */ \
1583 INSN_2(JMP, CALL), \
1584 /* Exit instruction. */ \
1585 INSN_2(JMP, EXIT), \
1586 /* 32-bit Jump instructions. */ \
1587 /* Register based. */ \
1588 INSN_3(JMP32, JEQ, X), \
1589 INSN_3(JMP32, JNE, X), \
1590 INSN_3(JMP32, JGT, X), \
1591 INSN_3(JMP32, JLT, X), \
1592 INSN_3(JMP32, JGE, X), \
1593 INSN_3(JMP32, JLE, X), \
1594 INSN_3(JMP32, JSGT, X), \
1595 INSN_3(JMP32, JSLT, X), \
1596 INSN_3(JMP32, JSGE, X), \
1597 INSN_3(JMP32, JSLE, X), \
1598 INSN_3(JMP32, JSET, X), \
1599 /* Immediate based. */ \
1600 INSN_3(JMP32, JEQ, K), \
1601 INSN_3(JMP32, JNE, K), \
1602 INSN_3(JMP32, JGT, K), \
1603 INSN_3(JMP32, JLT, K), \
1604 INSN_3(JMP32, JGE, K), \
1605 INSN_3(JMP32, JLE, K), \
1606 INSN_3(JMP32, JSGT, K), \
1607 INSN_3(JMP32, JSLT, K), \
1608 INSN_3(JMP32, JSGE, K), \
1609 INSN_3(JMP32, JSLE, K), \
1610 INSN_3(JMP32, JSET, K), \
1611 /* Jump instructions. */ \
1612 /* Register based. */ \
1613 INSN_3(JMP, JEQ, X), \
1614 INSN_3(JMP, JNE, X), \
1615 INSN_3(JMP, JGT, X), \
1616 INSN_3(JMP, JLT, X), \
1617 INSN_3(JMP, JGE, X), \
1618 INSN_3(JMP, JLE, X), \
1619 INSN_3(JMP, JSGT, X), \
1620 INSN_3(JMP, JSLT, X), \
1621 INSN_3(JMP, JSGE, X), \
1622 INSN_3(JMP, JSLE, X), \
1623 INSN_3(JMP, JSET, X), \
1624 /* Immediate based. */ \
1625 INSN_3(JMP, JEQ, K), \
1626 INSN_3(JMP, JNE, K), \
1627 INSN_3(JMP, JGT, K), \
1628 INSN_3(JMP, JLT, K), \
1629 INSN_3(JMP, JGE, K), \
1630 INSN_3(JMP, JLE, K), \
1631 INSN_3(JMP, JSGT, K), \
1632 INSN_3(JMP, JSLT, K), \
1633 INSN_3(JMP, JSGE, K), \
1634 INSN_3(JMP, JSLE, K), \
1635 INSN_3(JMP, JSET, K), \
1636 INSN_2(JMP, JA), \
1637 INSN_2(JMP32, JA), \
1638 /* Store instructions. */ \
1639 /* Register based. */ \
1640 INSN_3(STX, MEM, B), \
1641 INSN_3(STX, MEM, H), \
1642 INSN_3(STX, MEM, W), \
1643 INSN_3(STX, MEM, DW), \
1644 INSN_3(STX, ATOMIC, W), \
1645 INSN_3(STX, ATOMIC, DW), \
1646 /* Immediate based. */ \
1647 INSN_3(ST, MEM, B), \
1648 INSN_3(ST, MEM, H), \
1649 INSN_3(ST, MEM, W), \
1650 INSN_3(ST, MEM, DW), \
1651 /* Load instructions. */ \
1652 /* Register based. */ \
1653 INSN_3(LDX, MEM, B), \
1654 INSN_3(LDX, MEM, H), \
1655 INSN_3(LDX, MEM, W), \
1656 INSN_3(LDX, MEM, DW), \
1657 INSN_3(LDX, MEMSX, B), \
1658 INSN_3(LDX, MEMSX, H), \
1659 INSN_3(LDX, MEMSX, W), \
1660 /* Immediate based. */ \
1661 INSN_3(LD, IMM, DW)
1662
1663bool bpf_opcode_in_insntable(u8 code)
1664{
1665#define BPF_INSN_2_TBL(x, y) [BPF_##x | BPF_##y] = true
1666#define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1667 static const bool public_insntable[256] = {
1668 [0 ... 255] = false,
1669 /* Now overwrite non-defaults ... */
1670 BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1671 /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1672 [BPF_LD | BPF_ABS | BPF_B] = true,
1673 [BPF_LD | BPF_ABS | BPF_H] = true,
1674 [BPF_LD | BPF_ABS | BPF_W] = true,
1675 [BPF_LD | BPF_IND | BPF_B] = true,
1676 [BPF_LD | BPF_IND | BPF_H] = true,
1677 [BPF_LD | BPF_IND | BPF_W] = true,
1678 };
1679#undef BPF_INSN_3_TBL
1680#undef BPF_INSN_2_TBL
1681 return public_insntable[code];
1682}
1683
1684#ifndef CONFIG_BPF_JIT_ALWAYS_ON
1685/**
1686 * ___bpf_prog_run - run eBPF program on a given context
1687 * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1688 * @insn: is the array of eBPF instructions
1689 *
1690 * Decode and execute eBPF instructions.
1691 *
1692 * Return: whatever value is in %BPF_R0 at program exit
1693 */
1694static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1695{
1696#define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y
1697#define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1698 static const void * const jumptable[256] __annotate_jump_table = {
1699 [0 ... 255] = &&default_label,
1700 /* Now overwrite non-defaults ... */
1701 BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1702 /* Non-UAPI available opcodes. */
1703 [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1704 [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1705 [BPF_ST | BPF_NOSPEC] = &&ST_NOSPEC,
1706 [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1707 [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1708 [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1709 [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1710 [BPF_LDX | BPF_PROBE_MEMSX | BPF_B] = &&LDX_PROBE_MEMSX_B,
1711 [BPF_LDX | BPF_PROBE_MEMSX | BPF_H] = &&LDX_PROBE_MEMSX_H,
1712 [BPF_LDX | BPF_PROBE_MEMSX | BPF_W] = &&LDX_PROBE_MEMSX_W,
1713 };
1714#undef BPF_INSN_3_LBL
1715#undef BPF_INSN_2_LBL
1716 u32 tail_call_cnt = 0;
1717
1718#define CONT ({ insn++; goto select_insn; })
1719#define CONT_JMP ({ insn++; goto select_insn; })
1720
1721select_insn:
1722 goto *jumptable[insn->code];
1723
1724 /* Explicitly mask the register-based shift amounts with 63 or 31
1725 * to avoid undefined behavior. Normally this won't affect the
1726 * generated code, for example, in case of native 64 bit archs such
1727 * as x86-64 or arm64, the compiler is optimizing the AND away for
1728 * the interpreter. In case of JITs, each of the JIT backends compiles
1729 * the BPF shift operations to machine instructions which produce
1730 * implementation-defined results in such a case; the resulting
1731 * contents of the register may be arbitrary, but program behaviour
1732 * as a whole remains defined. In other words, in case of JIT backends,
1733 * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1734 */
1735 /* ALU (shifts) */
1736#define SHT(OPCODE, OP) \
1737 ALU64_##OPCODE##_X: \
1738 DST = DST OP (SRC & 63); \
1739 CONT; \
1740 ALU_##OPCODE##_X: \
1741 DST = (u32) DST OP ((u32) SRC & 31); \
1742 CONT; \
1743 ALU64_##OPCODE##_K: \
1744 DST = DST OP IMM; \
1745 CONT; \
1746 ALU_##OPCODE##_K: \
1747 DST = (u32) DST OP (u32) IMM; \
1748 CONT;
1749 /* ALU (rest) */
1750#define ALU(OPCODE, OP) \
1751 ALU64_##OPCODE##_X: \
1752 DST = DST OP SRC; \
1753 CONT; \
1754 ALU_##OPCODE##_X: \
1755 DST = (u32) DST OP (u32) SRC; \
1756 CONT; \
1757 ALU64_##OPCODE##_K: \
1758 DST = DST OP IMM; \
1759 CONT; \
1760 ALU_##OPCODE##_K: \
1761 DST = (u32) DST OP (u32) IMM; \
1762 CONT;
1763 ALU(ADD, +)
1764 ALU(SUB, -)
1765 ALU(AND, &)
1766 ALU(OR, |)
1767 ALU(XOR, ^)
1768 ALU(MUL, *)
1769 SHT(LSH, <<)
1770 SHT(RSH, >>)
1771#undef SHT
1772#undef ALU
1773 ALU_NEG:
1774 DST = (u32) -DST;
1775 CONT;
1776 ALU64_NEG:
1777 DST = -DST;
1778 CONT;
1779 ALU_MOV_X:
1780 switch (OFF) {
1781 case 0:
1782 DST = (u32) SRC;
1783 break;
1784 case 8:
1785 DST = (u32)(s8) SRC;
1786 break;
1787 case 16:
1788 DST = (u32)(s16) SRC;
1789 break;
1790 }
1791 CONT;
1792 ALU_MOV_K:
1793 DST = (u32) IMM;
1794 CONT;
1795 ALU64_MOV_X:
1796 switch (OFF) {
1797 case 0:
1798 DST = SRC;
1799 break;
1800 case 8:
1801 DST = (s8) SRC;
1802 break;
1803 case 16:
1804 DST = (s16) SRC;
1805 break;
1806 case 32:
1807 DST = (s32) SRC;
1808 break;
1809 }
1810 CONT;
1811 ALU64_MOV_K:
1812 DST = IMM;
1813 CONT;
1814 LD_IMM_DW:
1815 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1816 insn++;
1817 CONT;
1818 ALU_ARSH_X:
1819 DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1820 CONT;
1821 ALU_ARSH_K:
1822 DST = (u64) (u32) (((s32) DST) >> IMM);
1823 CONT;
1824 ALU64_ARSH_X:
1825 (*(s64 *) &DST) >>= (SRC & 63);
1826 CONT;
1827 ALU64_ARSH_K:
1828 (*(s64 *) &DST) >>= IMM;
1829 CONT;
1830 ALU64_MOD_X:
1831 switch (OFF) {
1832 case 0:
1833 div64_u64_rem(DST, SRC, &AX);
1834 DST = AX;
1835 break;
1836 case 1:
1837 AX = div64_s64(DST, SRC);
1838 DST = DST - AX * SRC;
1839 break;
1840 }
1841 CONT;
1842 ALU_MOD_X:
1843 switch (OFF) {
1844 case 0:
1845 AX = (u32) DST;
1846 DST = do_div(AX, (u32) SRC);
1847 break;
1848 case 1:
1849 AX = abs((s32)DST);
1850 AX = do_div(AX, abs((s32)SRC));
1851 if ((s32)DST < 0)
1852 DST = (u32)-AX;
1853 else
1854 DST = (u32)AX;
1855 break;
1856 }
1857 CONT;
1858 ALU64_MOD_K:
1859 switch (OFF) {
1860 case 0:
1861 div64_u64_rem(DST, IMM, &AX);
1862 DST = AX;
1863 break;
1864 case 1:
1865 AX = div64_s64(DST, IMM);
1866 DST = DST - AX * IMM;
1867 break;
1868 }
1869 CONT;
1870 ALU_MOD_K:
1871 switch (OFF) {
1872 case 0:
1873 AX = (u32) DST;
1874 DST = do_div(AX, (u32) IMM);
1875 break;
1876 case 1:
1877 AX = abs((s32)DST);
1878 AX = do_div(AX, abs((s32)IMM));
1879 if ((s32)DST < 0)
1880 DST = (u32)-AX;
1881 else
1882 DST = (u32)AX;
1883 break;
1884 }
1885 CONT;
1886 ALU64_DIV_X:
1887 switch (OFF) {
1888 case 0:
1889 DST = div64_u64(DST, SRC);
1890 break;
1891 case 1:
1892 DST = div64_s64(DST, SRC);
1893 break;
1894 }
1895 CONT;
1896 ALU_DIV_X:
1897 switch (OFF) {
1898 case 0:
1899 AX = (u32) DST;
1900 do_div(AX, (u32) SRC);
1901 DST = (u32) AX;
1902 break;
1903 case 1:
1904 AX = abs((s32)DST);
1905 do_div(AX, abs((s32)SRC));
1906 if (((s32)DST < 0) == ((s32)SRC < 0))
1907 DST = (u32)AX;
1908 else
1909 DST = (u32)-AX;
1910 break;
1911 }
1912 CONT;
1913 ALU64_DIV_K:
1914 switch (OFF) {
1915 case 0:
1916 DST = div64_u64(DST, IMM);
1917 break;
1918 case 1:
1919 DST = div64_s64(DST, IMM);
1920 break;
1921 }
1922 CONT;
1923 ALU_DIV_K:
1924 switch (OFF) {
1925 case 0:
1926 AX = (u32) DST;
1927 do_div(AX, (u32) IMM);
1928 DST = (u32) AX;
1929 break;
1930 case 1:
1931 AX = abs((s32)DST);
1932 do_div(AX, abs((s32)IMM));
1933 if (((s32)DST < 0) == ((s32)IMM < 0))
1934 DST = (u32)AX;
1935 else
1936 DST = (u32)-AX;
1937 break;
1938 }
1939 CONT;
1940 ALU_END_TO_BE:
1941 switch (IMM) {
1942 case 16:
1943 DST = (__force u16) cpu_to_be16(DST);
1944 break;
1945 case 32:
1946 DST = (__force u32) cpu_to_be32(DST);
1947 break;
1948 case 64:
1949 DST = (__force u64) cpu_to_be64(DST);
1950 break;
1951 }
1952 CONT;
1953 ALU_END_TO_LE:
1954 switch (IMM) {
1955 case 16:
1956 DST = (__force u16) cpu_to_le16(DST);
1957 break;
1958 case 32:
1959 DST = (__force u32) cpu_to_le32(DST);
1960 break;
1961 case 64:
1962 DST = (__force u64) cpu_to_le64(DST);
1963 break;
1964 }
1965 CONT;
1966 ALU64_END_TO_LE:
1967 switch (IMM) {
1968 case 16:
1969 DST = (__force u16) __swab16(DST);
1970 break;
1971 case 32:
1972 DST = (__force u32) __swab32(DST);
1973 break;
1974 case 64:
1975 DST = (__force u64) __swab64(DST);
1976 break;
1977 }
1978 CONT;
1979
1980 /* CALL */
1981 JMP_CALL:
1982 /* Function call scratches BPF_R1-BPF_R5 registers,
1983 * preserves BPF_R6-BPF_R9, and stores return value
1984 * into BPF_R0.
1985 */
1986 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1987 BPF_R4, BPF_R5);
1988 CONT;
1989
1990 JMP_CALL_ARGS:
1991 BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
1992 BPF_R3, BPF_R4,
1993 BPF_R5,
1994 insn + insn->off + 1);
1995 CONT;
1996
1997 JMP_TAIL_CALL: {
1998 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1999 struct bpf_array *array = container_of(map, struct bpf_array, map);
2000 struct bpf_prog *prog;
2001 u32 index = BPF_R3;
2002
2003 if (unlikely(index >= array->map.max_entries))
2004 goto out;
2005
2006 if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
2007 goto out;
2008
2009 tail_call_cnt++;
2010
2011 prog = READ_ONCE(array->ptrs[index]);
2012 if (!prog)
2013 goto out;
2014
2015 /* ARG1 at this point is guaranteed to point to CTX from
2016 * the verifier side due to the fact that the tail call is
2017 * handled like a helper, that is, bpf_tail_call_proto,
2018 * where arg1_type is ARG_PTR_TO_CTX.
2019 */
2020 insn = prog->insnsi;
2021 goto select_insn;
2022out:
2023 CONT;
2024 }
2025 JMP_JA:
2026 insn += insn->off;
2027 CONT;
2028 JMP32_JA:
2029 insn += insn->imm;
2030 CONT;
2031 JMP_EXIT:
2032 return BPF_R0;
2033 /* JMP */
2034#define COND_JMP(SIGN, OPCODE, CMP_OP) \
2035 JMP_##OPCODE##_X: \
2036 if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) { \
2037 insn += insn->off; \
2038 CONT_JMP; \
2039 } \
2040 CONT; \
2041 JMP32_##OPCODE##_X: \
2042 if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) { \
2043 insn += insn->off; \
2044 CONT_JMP; \
2045 } \
2046 CONT; \
2047 JMP_##OPCODE##_K: \
2048 if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) { \
2049 insn += insn->off; \
2050 CONT_JMP; \
2051 } \
2052 CONT; \
2053 JMP32_##OPCODE##_K: \
2054 if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) { \
2055 insn += insn->off; \
2056 CONT_JMP; \
2057 } \
2058 CONT;
2059 COND_JMP(u, JEQ, ==)
2060 COND_JMP(u, JNE, !=)
2061 COND_JMP(u, JGT, >)
2062 COND_JMP(u, JLT, <)
2063 COND_JMP(u, JGE, >=)
2064 COND_JMP(u, JLE, <=)
2065 COND_JMP(u, JSET, &)
2066 COND_JMP(s, JSGT, >)
2067 COND_JMP(s, JSLT, <)
2068 COND_JMP(s, JSGE, >=)
2069 COND_JMP(s, JSLE, <=)
2070#undef COND_JMP
2071 /* ST, STX and LDX*/
2072 ST_NOSPEC:
2073 /* Speculation barrier for mitigating Speculative Store Bypass.
2074 * In case of arm64, we rely on the firmware mitigation as
2075 * controlled via the ssbd kernel parameter. Whenever the
2076 * mitigation is enabled, it works for all of the kernel code
2077 * with no need to provide any additional instructions here.
2078 * In case of x86, we use 'lfence' insn for mitigation. We
2079 * reuse preexisting logic from Spectre v1 mitigation that
2080 * happens to produce the required code on x86 for v4 as well.
2081 */
2082 barrier_nospec();
2083 CONT;
2084#define LDST(SIZEOP, SIZE) \
2085 STX_MEM_##SIZEOP: \
2086 *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \
2087 CONT; \
2088 ST_MEM_##SIZEOP: \
2089 *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \
2090 CONT; \
2091 LDX_MEM_##SIZEOP: \
2092 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \
2093 CONT; \
2094 LDX_PROBE_MEM_##SIZEOP: \
2095 bpf_probe_read_kernel_common(&DST, sizeof(SIZE), \
2096 (const void *)(long) (SRC + insn->off)); \
2097 DST = *((SIZE *)&DST); \
2098 CONT;
2099
2100 LDST(B, u8)
2101 LDST(H, u16)
2102 LDST(W, u32)
2103 LDST(DW, u64)
2104#undef LDST
2105
2106#define LDSX(SIZEOP, SIZE) \
2107 LDX_MEMSX_##SIZEOP: \
2108 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \
2109 CONT; \
2110 LDX_PROBE_MEMSX_##SIZEOP: \
2111 bpf_probe_read_kernel_common(&DST, sizeof(SIZE), \
2112 (const void *)(long) (SRC + insn->off)); \
2113 DST = *((SIZE *)&DST); \
2114 CONT;
2115
2116 LDSX(B, s8)
2117 LDSX(H, s16)
2118 LDSX(W, s32)
2119#undef LDSX
2120
2121#define ATOMIC_ALU_OP(BOP, KOP) \
2122 case BOP: \
2123 if (BPF_SIZE(insn->code) == BPF_W) \
2124 atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
2125 (DST + insn->off)); \
2126 else \
2127 atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
2128 (DST + insn->off)); \
2129 break; \
2130 case BOP | BPF_FETCH: \
2131 if (BPF_SIZE(insn->code) == BPF_W) \
2132 SRC = (u32) atomic_fetch_##KOP( \
2133 (u32) SRC, \
2134 (atomic_t *)(unsigned long) (DST + insn->off)); \
2135 else \
2136 SRC = (u64) atomic64_fetch_##KOP( \
2137 (u64) SRC, \
2138 (atomic64_t *)(unsigned long) (DST + insn->off)); \
2139 break;
2140
2141 STX_ATOMIC_DW:
2142 STX_ATOMIC_W:
2143 switch (IMM) {
2144 ATOMIC_ALU_OP(BPF_ADD, add)
2145 ATOMIC_ALU_OP(BPF_AND, and)
2146 ATOMIC_ALU_OP(BPF_OR, or)
2147 ATOMIC_ALU_OP(BPF_XOR, xor)
2148#undef ATOMIC_ALU_OP
2149
2150 case BPF_XCHG:
2151 if (BPF_SIZE(insn->code) == BPF_W)
2152 SRC = (u32) atomic_xchg(
2153 (atomic_t *)(unsigned long) (DST + insn->off),
2154 (u32) SRC);
2155 else
2156 SRC = (u64) atomic64_xchg(
2157 (atomic64_t *)(unsigned long) (DST + insn->off),
2158 (u64) SRC);
2159 break;
2160 case BPF_CMPXCHG:
2161 if (BPF_SIZE(insn->code) == BPF_W)
2162 BPF_R0 = (u32) atomic_cmpxchg(
2163 (atomic_t *)(unsigned long) (DST + insn->off),
2164 (u32) BPF_R0, (u32) SRC);
2165 else
2166 BPF_R0 = (u64) atomic64_cmpxchg(
2167 (atomic64_t *)(unsigned long) (DST + insn->off),
2168 (u64) BPF_R0, (u64) SRC);
2169 break;
2170
2171 default:
2172 goto default_label;
2173 }
2174 CONT;
2175
2176 default_label:
2177 /* If we ever reach this, we have a bug somewhere. Die hard here
2178 * instead of just returning 0; we could be somewhere in a subprog,
2179 * so execution could continue otherwise which we do /not/ want.
2180 *
2181 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2182 */
2183 pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2184 insn->code, insn->imm);
2185 BUG_ON(1);
2186 return 0;
2187}
2188
2189#define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2190#define DEFINE_BPF_PROG_RUN(stack_size) \
2191static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2192{ \
2193 u64 stack[stack_size / sizeof(u64)]; \
2194 u64 regs[MAX_BPF_EXT_REG] = {}; \
2195\
2196 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2197 ARG1 = (u64) (unsigned long) ctx; \
2198 return ___bpf_prog_run(regs, insn); \
2199}
2200
2201#define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2202#define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2203static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2204 const struct bpf_insn *insn) \
2205{ \
2206 u64 stack[stack_size / sizeof(u64)]; \
2207 u64 regs[MAX_BPF_EXT_REG]; \
2208\
2209 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2210 BPF_R1 = r1; \
2211 BPF_R2 = r2; \
2212 BPF_R3 = r3; \
2213 BPF_R4 = r4; \
2214 BPF_R5 = r5; \
2215 return ___bpf_prog_run(regs, insn); \
2216}
2217
2218#define EVAL1(FN, X) FN(X)
2219#define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2220#define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2221#define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2222#define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2223#define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2224
2225EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2226EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2227EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2228
2229EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2230EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2231EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2232
2233#define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2234
2235static unsigned int (*interpreters[])(const void *ctx,
2236 const struct bpf_insn *insn) = {
2237EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2238EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2239EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2240};
2241#undef PROG_NAME_LIST
2242#define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2243static __maybe_unused
2244u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2245 const struct bpf_insn *insn) = {
2246EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2247EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2248EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2249};
2250#undef PROG_NAME_LIST
2251
2252#ifdef CONFIG_BPF_SYSCALL
2253void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2254{
2255 stack_depth = max_t(u32, stack_depth, 1);
2256 insn->off = (s16) insn->imm;
2257 insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
2258 __bpf_call_base_args;
2259 insn->code = BPF_JMP | BPF_CALL_ARGS;
2260}
2261#endif
2262#else
2263static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2264 const struct bpf_insn *insn)
2265{
2266 /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2267 * is not working properly, so warn about it!
2268 */
2269 WARN_ON_ONCE(1);
2270 return 0;
2271}
2272#endif
2273
2274bool bpf_prog_map_compatible(struct bpf_map *map,
2275 const struct bpf_prog *fp)
2276{
2277 enum bpf_prog_type prog_type = resolve_prog_type(fp);
2278 bool ret;
2279
2280 if (fp->kprobe_override)
2281 return false;
2282
2283 /* XDP programs inserted into maps are not guaranteed to run on
2284 * a particular netdev (and can run outside driver context entirely
2285 * in the case of devmap and cpumap). Until device checks
2286 * are implemented, prohibit adding dev-bound programs to program maps.
2287 */
2288 if (bpf_prog_is_dev_bound(fp->aux))
2289 return false;
2290
2291 spin_lock(&map->owner.lock);
2292 if (!map->owner.type) {
2293 /* There's no owner yet where we could check for
2294 * compatibility.
2295 */
2296 map->owner.type = prog_type;
2297 map->owner.jited = fp->jited;
2298 map->owner.xdp_has_frags = fp->aux->xdp_has_frags;
2299 ret = true;
2300 } else {
2301 ret = map->owner.type == prog_type &&
2302 map->owner.jited == fp->jited &&
2303 map->owner.xdp_has_frags == fp->aux->xdp_has_frags;
2304 }
2305 spin_unlock(&map->owner.lock);
2306
2307 return ret;
2308}
2309
2310static int bpf_check_tail_call(const struct bpf_prog *fp)
2311{
2312 struct bpf_prog_aux *aux = fp->aux;
2313 int i, ret = 0;
2314
2315 mutex_lock(&aux->used_maps_mutex);
2316 for (i = 0; i < aux->used_map_cnt; i++) {
2317 struct bpf_map *map = aux->used_maps[i];
2318
2319 if (!map_type_contains_progs(map))
2320 continue;
2321
2322 if (!bpf_prog_map_compatible(map, fp)) {
2323 ret = -EINVAL;
2324 goto out;
2325 }
2326 }
2327
2328out:
2329 mutex_unlock(&aux->used_maps_mutex);
2330 return ret;
2331}
2332
2333static void bpf_prog_select_func(struct bpf_prog *fp)
2334{
2335#ifndef CONFIG_BPF_JIT_ALWAYS_ON
2336 u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2337
2338 fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
2339#else
2340 fp->bpf_func = __bpf_prog_ret0_warn;
2341#endif
2342}
2343
2344/**
2345 * bpf_prog_select_runtime - select exec runtime for BPF program
2346 * @fp: bpf_prog populated with BPF program
2347 * @err: pointer to error variable
2348 *
2349 * Try to JIT eBPF program, if JIT is not available, use interpreter.
2350 * The BPF program will be executed via bpf_prog_run() function.
2351 *
2352 * Return: the &fp argument along with &err set to 0 for success or
2353 * a negative errno code on failure
2354 */
2355struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2356{
2357 /* In case of BPF to BPF calls, verifier did all the prep
2358 * work with regards to JITing, etc.
2359 */
2360 bool jit_needed = false;
2361
2362 if (fp->bpf_func)
2363 goto finalize;
2364
2365 if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
2366 bpf_prog_has_kfunc_call(fp))
2367 jit_needed = true;
2368
2369 bpf_prog_select_func(fp);
2370
2371 /* eBPF JITs can rewrite the program in case constant
2372 * blinding is active. However, in case of error during
2373 * blinding, bpf_int_jit_compile() must always return a
2374 * valid program, which in this case would simply not
2375 * be JITed, but falls back to the interpreter.
2376 */
2377 if (!bpf_prog_is_offloaded(fp->aux)) {
2378 *err = bpf_prog_alloc_jited_linfo(fp);
2379 if (*err)
2380 return fp;
2381
2382 fp = bpf_int_jit_compile(fp);
2383 bpf_prog_jit_attempt_done(fp);
2384 if (!fp->jited && jit_needed) {
2385 *err = -ENOTSUPP;
2386 return fp;
2387 }
2388 } else {
2389 *err = bpf_prog_offload_compile(fp);
2390 if (*err)
2391 return fp;
2392 }
2393
2394finalize:
2395 bpf_prog_lock_ro(fp);
2396
2397 /* The tail call compatibility check can only be done at
2398 * this late stage as we need to determine, if we deal
2399 * with JITed or non JITed program concatenations and not
2400 * all eBPF JITs might immediately support all features.
2401 */
2402 *err = bpf_check_tail_call(fp);
2403
2404 return fp;
2405}
2406EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2407
2408static unsigned int __bpf_prog_ret1(const void *ctx,
2409 const struct bpf_insn *insn)
2410{
2411 return 1;
2412}
2413
2414static struct bpf_prog_dummy {
2415 struct bpf_prog prog;
2416} dummy_bpf_prog = {
2417 .prog = {
2418 .bpf_func = __bpf_prog_ret1,
2419 },
2420};
2421
2422struct bpf_empty_prog_array bpf_empty_prog_array = {
2423 .null_prog = NULL,
2424};
2425EXPORT_SYMBOL(bpf_empty_prog_array);
2426
2427struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2428{
2429 if (prog_cnt)
2430 return kzalloc(sizeof(struct bpf_prog_array) +
2431 sizeof(struct bpf_prog_array_item) *
2432 (prog_cnt + 1),
2433 flags);
2434
2435 return &bpf_empty_prog_array.hdr;
2436}
2437
2438void bpf_prog_array_free(struct bpf_prog_array *progs)
2439{
2440 if (!progs || progs == &bpf_empty_prog_array.hdr)
2441 return;
2442 kfree_rcu(progs, rcu);
2443}
2444
2445static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2446{
2447 struct bpf_prog_array *progs;
2448
2449 /* If RCU Tasks Trace grace period implies RCU grace period, there is
2450 * no need to call kfree_rcu(), just call kfree() directly.
2451 */
2452 progs = container_of(rcu, struct bpf_prog_array, rcu);
2453 if (rcu_trace_implies_rcu_gp())
2454 kfree(progs);
2455 else
2456 kfree_rcu(progs, rcu);
2457}
2458
2459void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2460{
2461 if (!progs || progs == &bpf_empty_prog_array.hdr)
2462 return;
2463 call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2464}
2465
2466int bpf_prog_array_length(struct bpf_prog_array *array)
2467{
2468 struct bpf_prog_array_item *item;
2469 u32 cnt = 0;
2470
2471 for (item = array->items; item->prog; item++)
2472 if (item->prog != &dummy_bpf_prog.prog)
2473 cnt++;
2474 return cnt;
2475}
2476
2477bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2478{
2479 struct bpf_prog_array_item *item;
2480
2481 for (item = array->items; item->prog; item++)
2482 if (item->prog != &dummy_bpf_prog.prog)
2483 return false;
2484 return true;
2485}
2486
2487static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2488 u32 *prog_ids,
2489 u32 request_cnt)
2490{
2491 struct bpf_prog_array_item *item;
2492 int i = 0;
2493
2494 for (item = array->items; item->prog; item++) {
2495 if (item->prog == &dummy_bpf_prog.prog)
2496 continue;
2497 prog_ids[i] = item->prog->aux->id;
2498 if (++i == request_cnt) {
2499 item++;
2500 break;
2501 }
2502 }
2503
2504 return !!(item->prog);
2505}
2506
2507int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2508 __u32 __user *prog_ids, u32 cnt)
2509{
2510 unsigned long err = 0;
2511 bool nospc;
2512 u32 *ids;
2513
2514 /* users of this function are doing:
2515 * cnt = bpf_prog_array_length();
2516 * if (cnt > 0)
2517 * bpf_prog_array_copy_to_user(..., cnt);
2518 * so below kcalloc doesn't need extra cnt > 0 check.
2519 */
2520 ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2521 if (!ids)
2522 return -ENOMEM;
2523 nospc = bpf_prog_array_copy_core(array, ids, cnt);
2524 err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2525 kfree(ids);
2526 if (err)
2527 return -EFAULT;
2528 if (nospc)
2529 return -ENOSPC;
2530 return 0;
2531}
2532
2533void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2534 struct bpf_prog *old_prog)
2535{
2536 struct bpf_prog_array_item *item;
2537
2538 for (item = array->items; item->prog; item++)
2539 if (item->prog == old_prog) {
2540 WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2541 break;
2542 }
2543}
2544
2545/**
2546 * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2547 * index into the program array with
2548 * a dummy no-op program.
2549 * @array: a bpf_prog_array
2550 * @index: the index of the program to replace
2551 *
2552 * Skips over dummy programs, by not counting them, when calculating
2553 * the position of the program to replace.
2554 *
2555 * Return:
2556 * * 0 - Success
2557 * * -EINVAL - Invalid index value. Must be a non-negative integer.
2558 * * -ENOENT - Index out of range
2559 */
2560int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2561{
2562 return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2563}
2564
2565/**
2566 * bpf_prog_array_update_at() - Updates the program at the given index
2567 * into the program array.
2568 * @array: a bpf_prog_array
2569 * @index: the index of the program to update
2570 * @prog: the program to insert into the array
2571 *
2572 * Skips over dummy programs, by not counting them, when calculating
2573 * the position of the program to update.
2574 *
2575 * Return:
2576 * * 0 - Success
2577 * * -EINVAL - Invalid index value. Must be a non-negative integer.
2578 * * -ENOENT - Index out of range
2579 */
2580int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2581 struct bpf_prog *prog)
2582{
2583 struct bpf_prog_array_item *item;
2584
2585 if (unlikely(index < 0))
2586 return -EINVAL;
2587
2588 for (item = array->items; item->prog; item++) {
2589 if (item->prog == &dummy_bpf_prog.prog)
2590 continue;
2591 if (!index) {
2592 WRITE_ONCE(item->prog, prog);
2593 return 0;
2594 }
2595 index--;
2596 }
2597 return -ENOENT;
2598}
2599
2600int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2601 struct bpf_prog *exclude_prog,
2602 struct bpf_prog *include_prog,
2603 u64 bpf_cookie,
2604 struct bpf_prog_array **new_array)
2605{
2606 int new_prog_cnt, carry_prog_cnt = 0;
2607 struct bpf_prog_array_item *existing, *new;
2608 struct bpf_prog_array *array;
2609 bool found_exclude = false;
2610
2611 /* Figure out how many existing progs we need to carry over to
2612 * the new array.
2613 */
2614 if (old_array) {
2615 existing = old_array->items;
2616 for (; existing->prog; existing++) {
2617 if (existing->prog == exclude_prog) {
2618 found_exclude = true;
2619 continue;
2620 }
2621 if (existing->prog != &dummy_bpf_prog.prog)
2622 carry_prog_cnt++;
2623 if (existing->prog == include_prog)
2624 return -EEXIST;
2625 }
2626 }
2627
2628 if (exclude_prog && !found_exclude)
2629 return -ENOENT;
2630
2631 /* How many progs (not NULL) will be in the new array? */
2632 new_prog_cnt = carry_prog_cnt;
2633 if (include_prog)
2634 new_prog_cnt += 1;
2635
2636 /* Do we have any prog (not NULL) in the new array? */
2637 if (!new_prog_cnt) {
2638 *new_array = NULL;
2639 return 0;
2640 }
2641
2642 /* +1 as the end of prog_array is marked with NULL */
2643 array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2644 if (!array)
2645 return -ENOMEM;
2646 new = array->items;
2647
2648 /* Fill in the new prog array */
2649 if (carry_prog_cnt) {
2650 existing = old_array->items;
2651 for (; existing->prog; existing++) {
2652 if (existing->prog == exclude_prog ||
2653 existing->prog == &dummy_bpf_prog.prog)
2654 continue;
2655
2656 new->prog = existing->prog;
2657 new->bpf_cookie = existing->bpf_cookie;
2658 new++;
2659 }
2660 }
2661 if (include_prog) {
2662 new->prog = include_prog;
2663 new->bpf_cookie = bpf_cookie;
2664 new++;
2665 }
2666 new->prog = NULL;
2667 *new_array = array;
2668 return 0;
2669}
2670
2671int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2672 u32 *prog_ids, u32 request_cnt,
2673 u32 *prog_cnt)
2674{
2675 u32 cnt = 0;
2676
2677 if (array)
2678 cnt = bpf_prog_array_length(array);
2679
2680 *prog_cnt = cnt;
2681
2682 /* return early if user requested only program count or nothing to copy */
2683 if (!request_cnt || !cnt)
2684 return 0;
2685
2686 /* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2687 return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2688 : 0;
2689}
2690
2691void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2692 struct bpf_map **used_maps, u32 len)
2693{
2694 struct bpf_map *map;
2695 bool sleepable;
2696 u32 i;
2697
2698 sleepable = aux->sleepable;
2699 for (i = 0; i < len; i++) {
2700 map = used_maps[i];
2701 if (map->ops->map_poke_untrack)
2702 map->ops->map_poke_untrack(map, aux);
2703 if (sleepable)
2704 atomic64_dec(&map->sleepable_refcnt);
2705 bpf_map_put(map);
2706 }
2707}
2708
2709static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2710{
2711 __bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2712 kfree(aux->used_maps);
2713}
2714
2715void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
2716 struct btf_mod_pair *used_btfs, u32 len)
2717{
2718#ifdef CONFIG_BPF_SYSCALL
2719 struct btf_mod_pair *btf_mod;
2720 u32 i;
2721
2722 for (i = 0; i < len; i++) {
2723 btf_mod = &used_btfs[i];
2724 if (btf_mod->module)
2725 module_put(btf_mod->module);
2726 btf_put(btf_mod->btf);
2727 }
2728#endif
2729}
2730
2731static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2732{
2733 __bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt);
2734 kfree(aux->used_btfs);
2735}
2736
2737static void bpf_prog_free_deferred(struct work_struct *work)
2738{
2739 struct bpf_prog_aux *aux;
2740 int i;
2741
2742 aux = container_of(work, struct bpf_prog_aux, work);
2743#ifdef CONFIG_BPF_SYSCALL
2744 bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
2745#endif
2746#ifdef CONFIG_CGROUP_BPF
2747 if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
2748 bpf_cgroup_atype_put(aux->cgroup_atype);
2749#endif
2750 bpf_free_used_maps(aux);
2751 bpf_free_used_btfs(aux);
2752 if (bpf_prog_is_dev_bound(aux))
2753 bpf_prog_dev_bound_destroy(aux->prog);
2754#ifdef CONFIG_PERF_EVENTS
2755 if (aux->prog->has_callchain_buf)
2756 put_callchain_buffers();
2757#endif
2758 if (aux->dst_trampoline)
2759 bpf_trampoline_put(aux->dst_trampoline);
2760 for (i = 0; i < aux->real_func_cnt; i++) {
2761 /* We can just unlink the subprog poke descriptor table as
2762 * it was originally linked to the main program and is also
2763 * released along with it.
2764 */
2765 aux->func[i]->aux->poke_tab = NULL;
2766 bpf_jit_free(aux->func[i]);
2767 }
2768 if (aux->real_func_cnt) {
2769 kfree(aux->func);
2770 bpf_prog_unlock_free(aux->prog);
2771 } else {
2772 bpf_jit_free(aux->prog);
2773 }
2774}
2775
2776void bpf_prog_free(struct bpf_prog *fp)
2777{
2778 struct bpf_prog_aux *aux = fp->aux;
2779
2780 if (aux->dst_prog)
2781 bpf_prog_put(aux->dst_prog);
2782 INIT_WORK(&aux->work, bpf_prog_free_deferred);
2783 schedule_work(&aux->work);
2784}
2785EXPORT_SYMBOL_GPL(bpf_prog_free);
2786
2787/* RNG for unpriviledged user space with separated state from prandom_u32(). */
2788static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2789
2790void bpf_user_rnd_init_once(void)
2791{
2792 prandom_init_once(&bpf_user_rnd_state);
2793}
2794
2795BPF_CALL_0(bpf_user_rnd_u32)
2796{
2797 /* Should someone ever have the rather unwise idea to use some
2798 * of the registers passed into this function, then note that
2799 * this function is called from native eBPF and classic-to-eBPF
2800 * transformations. Register assignments from both sides are
2801 * different, f.e. classic always sets fn(ctx, A, X) here.
2802 */
2803 struct rnd_state *state;
2804 u32 res;
2805
2806 state = &get_cpu_var(bpf_user_rnd_state);
2807 res = prandom_u32_state(state);
2808 put_cpu_var(bpf_user_rnd_state);
2809
2810 return res;
2811}
2812
2813BPF_CALL_0(bpf_get_raw_cpu_id)
2814{
2815 return raw_smp_processor_id();
2816}
2817
2818/* Weak definitions of helper functions in case we don't have bpf syscall. */
2819const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2820const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2821const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2822const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2823const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2824const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2825const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
2826const struct bpf_func_proto bpf_spin_lock_proto __weak;
2827const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2828const struct bpf_func_proto bpf_jiffies64_proto __weak;
2829
2830const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2831const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2832const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2833const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2834const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2835const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2836const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
2837
2838const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2839const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2840const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2841const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2842const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2843const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2844const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2845const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2846const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2847const struct bpf_func_proto bpf_set_retval_proto __weak;
2848const struct bpf_func_proto bpf_get_retval_proto __weak;
2849
2850const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2851{
2852 return NULL;
2853}
2854
2855const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
2856{
2857 return NULL;
2858}
2859
2860u64 __weak
2861bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2862 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2863{
2864 return -ENOTSUPP;
2865}
2866EXPORT_SYMBOL_GPL(bpf_event_output);
2867
2868/* Always built-in helper functions. */
2869const struct bpf_func_proto bpf_tail_call_proto = {
2870 .func = NULL,
2871 .gpl_only = false,
2872 .ret_type = RET_VOID,
2873 .arg1_type = ARG_PTR_TO_CTX,
2874 .arg2_type = ARG_CONST_MAP_PTR,
2875 .arg3_type = ARG_ANYTHING,
2876};
2877
2878/* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2879 * It is encouraged to implement bpf_int_jit_compile() instead, so that
2880 * eBPF and implicitly also cBPF can get JITed!
2881 */
2882struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2883{
2884 return prog;
2885}
2886
2887/* Stub for JITs that support eBPF. All cBPF code gets transformed into
2888 * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2889 */
2890void __weak bpf_jit_compile(struct bpf_prog *prog)
2891{
2892}
2893
2894bool __weak bpf_helper_changes_pkt_data(void *func)
2895{
2896 return false;
2897}
2898
2899/* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2900 * analysis code and wants explicit zero extension inserted by verifier.
2901 * Otherwise, return FALSE.
2902 *
2903 * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2904 * you don't override this. JITs that don't want these extra insns can detect
2905 * them using insn_is_zext.
2906 */
2907bool __weak bpf_jit_needs_zext(void)
2908{
2909 return false;
2910}
2911
2912/* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
2913bool __weak bpf_jit_supports_subprog_tailcalls(void)
2914{
2915 return false;
2916}
2917
2918bool __weak bpf_jit_supports_kfunc_call(void)
2919{
2920 return false;
2921}
2922
2923bool __weak bpf_jit_supports_far_kfunc_call(void)
2924{
2925 return false;
2926}
2927
2928/* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
2929 * skb_copy_bits(), so provide a weak definition of it for NET-less config.
2930 */
2931int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
2932 int len)
2933{
2934 return -EFAULT;
2935}
2936
2937int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
2938 void *addr1, void *addr2)
2939{
2940 return -ENOTSUPP;
2941}
2942
2943void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
2944{
2945 return ERR_PTR(-ENOTSUPP);
2946}
2947
2948int __weak bpf_arch_text_invalidate(void *dst, size_t len)
2949{
2950 return -ENOTSUPP;
2951}
2952
2953bool __weak bpf_jit_supports_exceptions(void)
2954{
2955 return false;
2956}
2957
2958void __weak arch_bpf_stack_walk(bool (*consume_fn)(void *cookie, u64 ip, u64 sp, u64 bp), void *cookie)
2959{
2960}
2961
2962#ifdef CONFIG_BPF_SYSCALL
2963static int __init bpf_global_ma_init(void)
2964{
2965 int ret;
2966
2967 ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
2968 bpf_global_ma_set = !ret;
2969 return ret;
2970}
2971late_initcall(bpf_global_ma_init);
2972#endif
2973
2974DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
2975EXPORT_SYMBOL(bpf_stats_enabled_key);
2976
2977/* All definitions of tracepoints related to BPF. */
2978#define CREATE_TRACE_POINTS
2979#include <linux/bpf_trace.h>
2980
2981EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
2982EXPORT_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);