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