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