projects/linux·blob master · refs

3604 lines · 91.7 KiB

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 <[email protected]>
13 * Alexei Starovoitov <[email protected]>
14 * Daniel Borkmann <[email protected]>
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/sched/signal.h>
23#include <linux/skbuff.h>
24#include <linux/static_call.h>
25#include <linux/vmalloc.h>
26#include <linux/prandom.h>
27#include <linux/bpf.h>
28#include <linux/btf.h>
29#include <linux/hex.h>
30#include <linux/objtool.h>
31#include <linux/overflow.h>
32#include <linux/rbtree_latch.h>
33#include <linux/kallsyms.h>
34#include <linux/rcupdate.h>
35#include <linux/perf_event.h>
36#include <linux/extable.h>
37#include <linux/log2.h>
38#include <linux/bpf_verifier.h>
39#include <linux/nodemask.h>
40#include <linux/nospec.h>
41#include <linux/bpf_mem_alloc.h>
42#include <linux/memcontrol.h>
43#include <linux/execmem.h>
44#include <crypto/sha2.h>
45
46#include <asm/barrier.h>
47#include <linux/unaligned.h>
48
49/* Registers */
50#define BPF_R0 regs[BPF_REG_0]
51#define BPF_R1 regs[BPF_REG_1]
52#define BPF_R2 regs[BPF_REG_2]
53#define BPF_R3 regs[BPF_REG_3]
54#define BPF_R4 regs[BPF_REG_4]
55#define BPF_R5 regs[BPF_REG_5]
56#define BPF_R6 regs[BPF_REG_6]
57#define BPF_R7 regs[BPF_REG_7]
58#define BPF_R8 regs[BPF_REG_8]
59#define BPF_R9 regs[BPF_REG_9]
60#define BPF_R10 regs[BPF_REG_10]
61
62/* Named registers */
63#define DST regs[insn->dst_reg]
64#define SRC regs[insn->src_reg]
65#define FP regs[BPF_REG_FP]
66#define AX regs[BPF_REG_AX]
67#define ARG1 regs[BPF_REG_ARG1]
68#define CTX regs[BPF_REG_CTX]
69#define OFF insn->off
70#define IMM insn->imm
71
72struct bpf_mem_alloc bpf_global_ma;
73bool bpf_global_ma_set;
74
75/* No hurry in this branch
76 *
77 * Exported for the bpf jit load helper.
78 */
79void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
80{
81 u8 *ptr = NULL;
82
83 if (k >= SKF_NET_OFF) {
84 ptr = skb_network_header(skb) + k - SKF_NET_OFF;
85 } else if (k >= SKF_LL_OFF) {
86 if (unlikely(!skb_mac_header_was_set(skb)))
87 return NULL;
88 ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
89 }
90 if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
91 return ptr;
92
93 return NULL;
94}
95
96/* tell bpf programs that include vmlinux.h kernel's PAGE_SIZE */
97enum page_size_enum {
98 __PAGE_SIZE = PAGE_SIZE
99};
100
101struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
102{
103 gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
104 struct bpf_prog_aux *aux;
105 struct bpf_prog *fp;
106
107 size = round_up(size, __PAGE_SIZE);
108 fp = __vmalloc(size, gfp_flags);
109 if (fp == NULL)
110 return NULL;
111
112 aux = kzalloc_obj(*aux, bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
113 if (aux == NULL) {
114 vfree(fp);
115 return NULL;
116 }
117 fp->active = __alloc_percpu_gfp(sizeof(u8[BPF_NR_CONTEXTS]), 4,
118 bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
119 if (!fp->active) {
120 vfree(fp);
121 kfree(aux);
122 return NULL;
123 }
124
125 fp->pages = size / PAGE_SIZE;
126 fp->aux = aux;
127 fp->aux->main_prog_aux = aux;
128 fp->aux->prog = fp;
129 fp->jit_requested = ebpf_jit_enabled();
130 fp->jit_required = IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON);
131 fp->blinding_requested = bpf_jit_blinding_enabled(fp);
132#ifdef CONFIG_CGROUP_BPF
133 aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID;
134#endif
135
136 INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
137#ifdef CONFIG_FINEIBT
138 INIT_LIST_HEAD_RCU(&fp->aux->ksym_prefix.lnode);
139#endif
140 mutex_init(&fp->aux->used_maps_mutex);
141 mutex_init(&fp->aux->ext_mutex);
142 mutex_init(&fp->aux->dst_mutex);
143 mutex_init(&fp->aux->st_ops_assoc_mutex);
144
145#ifdef CONFIG_BPF_SYSCALL
146 bpf_prog_stream_init(fp);
147#endif
148
149 return fp;
150}
151
152struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
153{
154 gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
155 struct bpf_prog *prog;
156 int cpu;
157
158 prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
159 if (!prog)
160 return NULL;
161
162 prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
163 if (!prog->stats) {
164 free_percpu(prog->active);
165 kfree(prog->aux);
166 vfree(prog);
167 return NULL;
168 }
169
170 for_each_possible_cpu(cpu) {
171 struct bpf_prog_stats *pstats;
172
173 pstats = per_cpu_ptr(prog->stats, cpu);
174 u64_stats_init(&pstats->syncp);
175 }
176 return prog;
177}
178EXPORT_SYMBOL_GPL(bpf_prog_alloc);
179
180int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
181{
182 if (!prog->aux->nr_linfo || !prog->jit_requested)
183 return 0;
184
185 prog->aux->jited_linfo = kvzalloc_objs(*prog->aux->jited_linfo,
186 prog->aux->nr_linfo,
187 bpf_memcg_flags(GFP_KERNEL | __GFP_NOWARN));
188 if (!prog->aux->jited_linfo)
189 return -ENOMEM;
190
191 return 0;
192}
193
194void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
195{
196 if (prog->aux->jited_linfo &&
197 (!prog->jited || !prog->aux->jited_linfo[0])) {
198 kvfree(prog->aux->jited_linfo);
199 prog->aux->jited_linfo = NULL;
200 }
201
202 kfree(prog->aux->kfunc_tab);
203 prog->aux->kfunc_tab = NULL;
204}
205
206/* The jit engine is responsible to provide an array
207 * for insn_off to the jited_off mapping (insn_to_jit_off).
208 *
209 * The idx to this array is the insn_off. Hence, the insn_off
210 * here is relative to the prog itself instead of the main prog.
211 * This array has one entry for each xlated bpf insn.
212 *
213 * jited_off is the byte off to the end of the jited insn.
214 *
215 * Hence, with
216 * insn_start:
217 * The first bpf insn off of the prog. The insn off
218 * here is relative to the main prog.
219 * e.g. if prog is a subprog, insn_start > 0
220 * linfo_idx:
221 * The prog's idx to prog->aux->linfo and jited_linfo
222 *
223 * jited_linfo[linfo_idx] = prog->bpf_func
224 *
225 * For i > linfo_idx,
226 *
227 * jited_linfo[i] = prog->bpf_func +
228 * insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
229 */
230void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
231 const u32 *insn_to_jit_off)
232{
233 u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
234 const struct bpf_line_info *linfo;
235 void **jited_linfo;
236
237 if (!prog->aux->jited_linfo || prog->aux->func_idx > prog->aux->func_cnt)
238 /* Userspace did not provide linfo */
239 return;
240
241 linfo_idx = prog->aux->linfo_idx;
242 linfo = &prog->aux->linfo[linfo_idx];
243 insn_start = linfo[0].insn_off;
244 insn_end = insn_start + prog->len;
245
246 jited_linfo = &prog->aux->jited_linfo[linfo_idx];
247 jited_linfo[0] = prog->bpf_func;
248
249 nr_linfo = prog->aux->nr_linfo - linfo_idx;
250
251 for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
252 /* The verifier ensures that linfo[i].insn_off is
253 * strictly increasing
254 */
255 jited_linfo[i] = prog->bpf_func +
256 insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
257}
258
259struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
260 gfp_t gfp_extra_flags)
261{
262 gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
263 struct bpf_prog *fp;
264 u32 pages;
265
266 size = round_up(size, PAGE_SIZE);
267 pages = size / PAGE_SIZE;
268 if (pages <= fp_old->pages)
269 return fp_old;
270
271 fp = __vmalloc(size, gfp_flags);
272 if (fp) {
273 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
274 fp->pages = pages;
275 fp->aux->prog = fp;
276
277 /* We keep fp->aux from fp_old around in the new
278 * reallocated structure.
279 */
280 fp_old->aux = NULL;
281 fp_old->stats = NULL;
282 fp_old->active = NULL;
283 __bpf_prog_free(fp_old);
284 }
285
286 return fp;
287}
288
289void __bpf_prog_free(struct bpf_prog *fp)
290{
291 if (fp->aux) {
292 mutex_destroy(&fp->aux->used_maps_mutex);
293 mutex_destroy(&fp->aux->dst_mutex);
294 mutex_destroy(&fp->aux->st_ops_assoc_mutex);
295 kfree(fp->aux->poke_tab);
296 kfree(fp->aux);
297 }
298 free_percpu(fp->stats);
299 free_percpu(fp->active);
300 vfree(fp);
301}
302
303int bpf_prog_calc_tag(struct bpf_prog *fp)
304{
305 size_t size = bpf_prog_insn_size(fp);
306 struct bpf_insn *dst;
307 bool was_ld_map;
308 u32 i;
309
310 dst = __vmalloc(size, GFP_KERNEL_ACCOUNT);
311 if (!dst)
312 return -ENOMEM;
313
314 /* We need to take out the map fd for the digest calculation
315 * since they are unstable from user space side.
316 */
317 for (i = 0, was_ld_map = false; i < fp->len; i++) {
318 dst[i] = fp->insnsi[i];
319 if (!was_ld_map &&
320 dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
321 (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
322 dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
323 was_ld_map = true;
324 dst[i].imm = 0;
325 } else if (was_ld_map &&
326 dst[i].code == 0 &&
327 dst[i].dst_reg == 0 &&
328 dst[i].src_reg == 0 &&
329 dst[i].off == 0) {
330 was_ld_map = false;
331 dst[i].imm = 0;
332 } else {
333 was_ld_map = false;
334 }
335 }
336 sha256((u8 *)dst, size, fp->digest);
337 vfree(dst);
338 return 0;
339}
340
341static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
342 s32 end_new, s32 curr, const bool probe_pass)
343{
344 const s64 imm_min = S32_MIN, imm_max = S32_MAX;
345 s32 delta = end_new - end_old;
346 s64 imm = insn->imm;
347
348 if (curr < pos && curr + imm + 1 >= end_old)
349 imm += delta;
350 else if (curr >= end_new && curr + imm + 1 < end_new)
351 imm -= delta;
352 if (imm < imm_min || imm > imm_max)
353 return -ERANGE;
354 if (!probe_pass)
355 insn->imm = imm;
356 return 0;
357}
358
359static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
360 s32 end_new, s32 curr, const bool probe_pass)
361{
362 s64 off_min, off_max, off;
363 s32 delta = end_new - end_old;
364
365 if (insn->code == (BPF_JMP32 | BPF_JA)) {
366 off = insn->imm;
367 off_min = S32_MIN;
368 off_max = S32_MAX;
369 } else {
370 off = insn->off;
371 off_min = S16_MIN;
372 off_max = S16_MAX;
373 }
374
375 if (curr < pos && curr + off + 1 >= end_old)
376 off += delta;
377 else if (curr >= end_new && curr + off + 1 < end_new)
378 off -= delta;
379 if (off < off_min || off > off_max)
380 return -ERANGE;
381 if (!probe_pass) {
382 if (insn->code == (BPF_JMP32 | BPF_JA))
383 insn->imm = off;
384 else
385 insn->off = off;
386 }
387 return 0;
388}
389
390static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
391 s32 end_new, const bool probe_pass)
392{
393 u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
394 struct bpf_insn *insn = prog->insnsi;
395 int ret = 0;
396
397 for (i = 0; i < insn_cnt; i++, insn++) {
398 u8 code;
399
400 /* In the probing pass we still operate on the original,
401 * unpatched image in order to check overflows before we
402 * do any other adjustments. Therefore skip the patchlet.
403 */
404 if (probe_pass && i == pos) {
405 i = end_new;
406 insn = prog->insnsi + end_old;
407 }
408 if (bpf_pseudo_func(insn)) {
409 ret = bpf_adj_delta_to_imm(insn, pos, end_old,
410 end_new, i, probe_pass);
411 if (ret)
412 return ret;
413 continue;
414 }
415 code = insn->code;
416 if ((BPF_CLASS(code) != BPF_JMP &&
417 BPF_CLASS(code) != BPF_JMP32) ||
418 BPF_OP(code) == BPF_EXIT)
419 continue;
420 /* Adjust offset of jmps if we cross patch boundaries. */
421 if (BPF_OP(code) == BPF_CALL) {
422 if (insn->src_reg != BPF_PSEUDO_CALL)
423 continue;
424 ret = bpf_adj_delta_to_imm(insn, pos, end_old,
425 end_new, i, probe_pass);
426 } else {
427 ret = bpf_adj_delta_to_off(insn, pos, end_old,
428 end_new, i, probe_pass);
429 }
430 if (ret)
431 break;
432 }
433
434 return ret;
435}
436
437static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
438{
439 struct bpf_line_info *linfo;
440 u32 i, nr_linfo;
441
442 nr_linfo = prog->aux->nr_linfo;
443 if (!nr_linfo || !delta)
444 return;
445
446 linfo = prog->aux->linfo;
447
448 for (i = 0; i < nr_linfo; i++)
449 if (off < linfo[i].insn_off)
450 break;
451
452 /* Push all off < linfo[i].insn_off by delta */
453 for (; i < nr_linfo; i++)
454 linfo[i].insn_off += delta;
455}
456
457struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
458 const struct bpf_insn *patch, u32 len)
459{
460 u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
461 const u32 cnt_max = S16_MAX;
462 struct bpf_prog *prog_adj;
463 int err;
464
465 /* Since our patchlet doesn't expand the image, we're done. */
466 if (insn_delta == 0) {
467 memcpy(prog->insnsi + off, patch, sizeof(*patch));
468 return prog;
469 }
470
471 insn_adj_cnt = prog->len + insn_delta;
472
473 /* Reject anything that would potentially let the insn->off
474 * target overflow when we have excessive program expansions.
475 * We need to probe here before we do any reallocation where
476 * we afterwards may not fail anymore.
477 */
478 if (insn_adj_cnt > cnt_max &&
479 (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
480 return ERR_PTR(err);
481
482 /* Several new instructions need to be inserted. Make room
483 * for them. Likely, there's no need for a new allocation as
484 * last page could have large enough tailroom.
485 */
486 prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
487 GFP_USER);
488 if (!prog_adj)
489 return ERR_PTR(-ENOMEM);
490
491 prog_adj->len = insn_adj_cnt;
492
493 /* Patching happens in 3 steps:
494 *
495 * 1) Move over tail of insnsi from next instruction onwards,
496 * so we can patch the single target insn with one or more
497 * new ones (patching is always from 1 to n insns, n > 0).
498 * 2) Inject new instructions at the target location.
499 * 3) Adjust branch offsets if necessary.
500 */
501 insn_rest = insn_adj_cnt - off - len;
502
503 memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
504 sizeof(*patch) * insn_rest);
505 memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
506
507 /* We are guaranteed to not fail at this point, otherwise
508 * the ship has sailed to reverse to the original state. An
509 * overflow cannot happen at this point.
510 */
511 BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
512
513 bpf_adj_linfo(prog_adj, off, insn_delta);
514
515 return prog_adj;
516}
517
518int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
519{
520 int err;
521
522 /* Branch offsets can't overflow when program is shrinking, no need
523 * to call bpf_adj_branches(..., true) here
524 */
525 memmove(prog->insnsi + off, prog->insnsi + off + cnt,
526 sizeof(struct bpf_insn) * (prog->len - off - cnt));
527 prog->len -= cnt;
528
529 err = bpf_adj_branches(prog, off, off + cnt, off, false);
530 WARN_ON_ONCE(err);
531 return err;
532}
533
534static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
535{
536 int i;
537
538 for (i = 0; i < fp->aux->real_func_cnt; i++)
539 bpf_prog_kallsyms_del(fp->aux->func[i]);
540}
541
542void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
543{
544 bpf_prog_kallsyms_del_subprogs(fp);
545 bpf_prog_kallsyms_del(fp);
546}
547
548#ifdef CONFIG_BPF_JIT
549/* All BPF JIT sysctl knobs here. */
550int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
551int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
552int bpf_jit_harden __read_mostly;
553long bpf_jit_limit __read_mostly;
554long bpf_jit_limit_max __read_mostly;
555
556static void
557bpf_prog_ksym_set_addr(struct bpf_prog *prog)
558{
559 WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
560
561 prog->aux->ksym.start = (unsigned long) prog->bpf_func;
562 prog->aux->ksym.end = prog->aux->ksym.start + prog->jited_len;
563}
564
565static void
566bpf_prog_ksym_set_name(struct bpf_prog *prog)
567{
568 char *sym = prog->aux->ksym.name;
569 const char *end = sym + KSYM_NAME_LEN;
570 const struct btf_type *type;
571 const char *func_name;
572
573 BUILD_BUG_ON(sizeof("bpf_prog_") +
574 sizeof(prog->tag) * 2 +
575 /* name has been null terminated.
576 * We should need +1 for the '_' preceding
577 * the name. However, the null character
578 * is double counted between the name and the
579 * sizeof("bpf_prog_") above, so we omit
580 * the +1 here.
581 */
582 sizeof(prog->aux->name) > KSYM_NAME_LEN);
583
584 sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
585 sym = bin2hex(sym, prog->tag, sizeof(prog->tag));
586
587 /* prog->aux->name will be ignored if full btf name is available */
588 if (prog->aux->func_info_cnt && prog->aux->func_idx < prog->aux->func_info_cnt) {
589 type = btf_type_by_id(prog->aux->btf,
590 prog->aux->func_info[prog->aux->func_idx].type_id);
591 func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
592 snprintf(sym, (size_t)(end - sym), "_%s", func_name);
593 return;
594 }
595
596 if (prog->aux->name[0])
597 snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
598 else
599 *sym = 0;
600}
601
602static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
603{
604 return container_of(n, struct bpf_ksym, tnode)->start;
605}
606
607static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
608 struct latch_tree_node *b)
609{
610 return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
611}
612
613static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
614{
615 unsigned long val = (unsigned long)key;
616 const struct bpf_ksym *ksym;
617
618 ksym = container_of(n, struct bpf_ksym, tnode);
619
620 if (val < ksym->start)
621 return -1;
622 /* Ensure that we detect return addresses as part of the program, when
623 * the final instruction is a call for a program part of the stack
624 * trace. Therefore, do val > ksym->end instead of val >= ksym->end.
625 */
626 if (val > ksym->end)
627 return 1;
628
629 return 0;
630}
631
632static const struct latch_tree_ops bpf_tree_ops = {
633 .less = bpf_tree_less,
634 .comp = bpf_tree_comp,
635};
636
637static DEFINE_SPINLOCK(bpf_lock);
638static LIST_HEAD(bpf_kallsyms);
639static struct latch_tree_root bpf_tree __cacheline_aligned;
640
641void 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
650static 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
659void 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
666static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
667{
668 return fp->jited && !bpf_prog_was_classic(fp);
669}
670
671void bpf_prog_kallsyms_add(struct bpf_prog *fp)
672{
673 if (!bpf_prog_kallsyms_candidate(fp) ||
674 !bpf_token_capable(fp->aux->token, CAP_BPF))
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#ifdef CONFIG_FINEIBT
684 /*
685 * When FineIBT, code in the __cfi_foo() symbols can get executed
686 * and hence unwinder needs help.
687 */
688 if (cfi_mode != CFI_FINEIBT)
689 return;
690
691 snprintf(fp->aux->ksym_prefix.name, KSYM_NAME_LEN,
692 "__cfi_%s", fp->aux->ksym.name);
693
694 fp->aux->ksym_prefix.start = (unsigned long) fp->bpf_func - 16;
695 fp->aux->ksym_prefix.end = (unsigned long) fp->bpf_func;
696
697 bpf_ksym_add(&fp->aux->ksym_prefix);
698#endif
699}
700
701void bpf_prog_kallsyms_del(struct bpf_prog *fp)
702{
703 if (!bpf_prog_kallsyms_candidate(fp))
704 return;
705
706 bpf_ksym_del(&fp->aux->ksym);
707#ifdef CONFIG_FINEIBT
708 if (cfi_mode != CFI_FINEIBT)
709 return;
710 bpf_ksym_del(&fp->aux->ksym_prefix);
711#endif
712}
713
714static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
715{
716 struct latch_tree_node *n;
717
718 n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
719 return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
720}
721
722int bpf_address_lookup(unsigned long addr, unsigned long *size,
723 unsigned long *off, char *sym)
724{
725 struct bpf_ksym *ksym;
726 int ret = 0;
727
728 rcu_read_lock();
729 ksym = bpf_ksym_find(addr);
730 if (ksym) {
731 unsigned long symbol_start = ksym->start;
732 unsigned long symbol_end = ksym->end;
733
734 ret = strscpy(sym, ksym->name, KSYM_NAME_LEN);
735
736 if (size)
737 *size = symbol_end - symbol_start;
738 if (off)
739 *off = addr - symbol_start;
740 }
741 rcu_read_unlock();
742
743 return ret;
744}
745
746bool is_bpf_text_address(unsigned long addr)
747{
748 bool ret;
749
750 rcu_read_lock();
751 ret = bpf_ksym_find(addr) != NULL;
752 rcu_read_unlock();
753
754 return ret;
755}
756
757struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
758{
759 struct bpf_ksym *ksym;
760
761 WARN_ON_ONCE(!rcu_read_lock_held());
762 ksym = bpf_ksym_find(addr);
763
764 return ksym && ksym->prog ?
765 container_of(ksym, struct bpf_prog_aux, ksym)->prog :
766 NULL;
767}
768
769bool bpf_has_frame_pointer(unsigned long ip)
770{
771 struct bpf_ksym *ksym;
772 unsigned long offset;
773
774 guard(rcu)();
775
776 ksym = bpf_ksym_find(ip);
777 if (!ksym || !ksym->fp_start || !ksym->fp_end)
778 return false;
779
780 offset = ip - ksym->start;
781
782 return offset >= ksym->fp_start && offset < ksym->fp_end;
783}
784
785const struct exception_table_entry *search_bpf_extables(unsigned long addr)
786{
787 const struct exception_table_entry *e = NULL;
788 struct bpf_prog *prog;
789
790 rcu_read_lock();
791 prog = bpf_prog_ksym_find(addr);
792 if (!prog)
793 goto out;
794 if (!prog->aux->num_exentries)
795 goto out;
796
797 e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
798out:
799 rcu_read_unlock();
800 return e;
801}
802
803int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
804 char *sym)
805{
806 struct bpf_ksym *ksym;
807 unsigned int it = 0;
808 int ret = -ERANGE;
809
810 if (!bpf_jit_kallsyms_enabled())
811 return ret;
812
813 rcu_read_lock();
814 list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
815 if (it++ != symnum)
816 continue;
817
818 strscpy(sym, ksym->name, KSYM_NAME_LEN);
819
820 *value = ksym->start;
821 *type = BPF_SYM_ELF_TYPE;
822
823 ret = 0;
824 break;
825 }
826 rcu_read_unlock();
827
828 return ret;
829}
830
831int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
832 struct bpf_jit_poke_descriptor *poke)
833{
834 struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
835 static const u32 poke_tab_max = 1024;
836 u32 slot = prog->aux->size_poke_tab;
837 u32 size = slot + 1;
838
839 if (size > poke_tab_max)
840 return -ENOSPC;
841 if (poke->tailcall_target || poke->tailcall_target_stable ||
842 poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
843 return -EINVAL;
844
845 switch (poke->reason) {
846 case BPF_POKE_REASON_TAIL_CALL:
847 if (!poke->tail_call.map)
848 return -EINVAL;
849 break;
850 default:
851 return -EINVAL;
852 }
853
854 tab = krealloc_array(tab, size, sizeof(*poke), GFP_KERNEL);
855 if (!tab)
856 return -ENOMEM;
857
858 memcpy(&tab[slot], poke, sizeof(*poke));
859 prog->aux->size_poke_tab = size;
860 prog->aux->poke_tab = tab;
861
862 return slot;
863}
864
865/*
866 * BPF program pack allocator.
867 *
868 * Most BPF programs are pretty small. Allocating a hole page for each
869 * program is sometime a waste. Many small bpf program also adds pressure
870 * to instruction TLB. To solve this issue, we introduce a BPF program pack
871 * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
872 * to host BPF programs.
873 */
874#define BPF_PROG_CHUNK_SHIFT 6
875#define BPF_PROG_CHUNK_SIZE (1 << BPF_PROG_CHUNK_SHIFT)
876#define BPF_PROG_CHUNK_MASK (~(BPF_PROG_CHUNK_SIZE - 1))
877
878struct bpf_prog_pack {
879 struct list_head list;
880 void *ptr;
881 bool arch_flush_needed;
882 unsigned long bitmap[];
883};
884
885void bpf_jit_fill_hole_with_zero(void *area, unsigned int size)
886{
887 memset(area, 0, size);
888}
889
890DEFINE_STATIC_CALL_NULL(bpf_arch_pred_flush, bpf_arch_pred_flush);
891
892/*
893 * Enabled once bpf_arch_pred_flush points at a real flush routine. Lets the
894 * pack allocator test "is a predictor flush wired up at all" with a cheap
895 * static branch instead of repeatedly querying the static call target.
896 */
897DEFINE_STATIC_KEY_FALSE(bpf_pred_flush_enabled);
898
899#define BPF_PROG_SIZE_TO_NBITS(size) (round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
900
901static DEFINE_MUTEX(pack_mutex);
902static LIST_HEAD(pack_list);
903
904/* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
905 * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
906 */
907#ifdef PMD_SIZE
908/* PMD_SIZE is really big for some archs. It doesn't make sense to
909 * reserve too much memory in one allocation. Hardcode BPF_PROG_PACK_SIZE to
910 * 2MiB * num_possible_nodes(). On most architectures PMD_SIZE will be
911 * greater than or equal to 2MB.
912 */
913#define BPF_PROG_PACK_SIZE (SZ_2M * num_possible_nodes())
914#else
915#define BPF_PROG_PACK_SIZE PAGE_SIZE
916#endif
917
918#define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
919
920static bool bpf_jit_mem_is_rox(void)
921{
922 return execmem_is_rox(EXECMEM_BPF);
923}
924
925static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
926{
927 struct bpf_prog_pack *pack;
928 int err;
929
930 pack = kzalloc_flex(*pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT));
931 if (!pack)
932 return NULL;
933 pack->ptr = bpf_jit_alloc_exec(BPF_PROG_PACK_SIZE);
934 if (!pack->ptr)
935 goto out;
936 bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
937
938 if (static_branch_unlikely(&bpf_pred_flush_enabled))
939 pack->arch_flush_needed = true;
940 if (!bpf_jit_mem_is_rox()) {
941 bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
942 set_vm_flush_reset_perms(pack->ptr);
943 err = set_memory_rox((unsigned long)pack->ptr,
944 BPF_PROG_PACK_SIZE / PAGE_SIZE);
945 if (err)
946 goto out;
947 }
948 list_add_tail(&pack->list, &pack_list);
949 return pack;
950
951out:
952 bpf_jit_free_exec(pack->ptr);
953 kfree(pack);
954 return NULL;
955}
956
957void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns, bool was_classic)
958{
959 unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
960 struct bpf_prog_pack *pack, *fallback_pack = NULL;
961 unsigned long pos, fallback_pos = 0;
962 void *ptr = NULL;
963
964 mutex_lock(&pack_mutex);
965 if (size > BPF_PROG_PACK_SIZE) {
966 /*
967 * Allocations larger than a pack get their own pages, and
968 * predictors are not flushed for such allocation. This is only
969 * safe because cBPF programs (the unprivileged attack surface)
970 * are bounded well below a pack size.
971 */
972 if (was_classic && static_branch_unlikely(&bpf_pred_flush_enabled))
973 pr_warn_once("BPF: Predictors not flushed for allocations greater than BPF_PROG_PACK_SIZE\n");
974 size = round_up(size, PAGE_SIZE);
975 ptr = bpf_jit_alloc_exec(size);
976 if (ptr && !bpf_jit_mem_is_rox()) {
977 int err;
978
979 bpf_fill_ill_insns(ptr, size);
980 set_vm_flush_reset_perms(ptr);
981 err = set_memory_rox((unsigned long)ptr,
982 size / PAGE_SIZE);
983 if (err) {
984 bpf_jit_free_exec(ptr);
985 ptr = NULL;
986 }
987 }
988 goto out;
989 }
990 list_for_each_entry(pack, &pack_list, list) {
991 pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
992 nbits, 0);
993 if (pos >= BPF_PROG_CHUNK_COUNT)
994 continue;
995 /* Flush not enabled, use any pack */
996 if (!static_branch_unlikely(&bpf_pred_flush_enabled))
997 goto found_free_area;
998 /*
999 * cBPF reuse of a dirty pack triggers a flush, so prefer a
1000 * clean pack for cBPF. eBPF never flushes, so steer it to a
1001 * dirty pack and keep clean packs free for cBPF.
1002 */
1003 if (was_classic ^ pack->arch_flush_needed)
1004 goto found_free_area;
1005 if (!fallback_pack) {
1006 fallback_pack = pack;
1007 fallback_pos = pos;
1008 }
1009 }
1010
1011 /* No preferred pack found */
1012 if (fallback_pack) {
1013 pack = fallback_pack;
1014 pos = fallback_pos;
1015 goto found_free_area;
1016 }
1017
1018 pack = alloc_new_pack(bpf_fill_ill_insns);
1019 if (!pack)
1020 goto out;
1021
1022 pos = 0;
1023
1024found_free_area:
1025 /* Flush only for cBPF as it may contain a crafted gadget */
1026 if (static_branch_unlikely(&bpf_pred_flush_enabled) &&
1027 pack->arch_flush_needed &&
1028 was_classic) {
1029 struct bpf_prog_pack *p;
1030
1031 static_call_cond(bpf_arch_pred_flush)();
1032 list_for_each_entry(p, &pack_list, list)
1033 p->arch_flush_needed = false;
1034 }
1035 bitmap_set(pack->bitmap, pos, nbits);
1036 ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
1037
1038out:
1039 mutex_unlock(&pack_mutex);
1040 return ptr;
1041}
1042
1043void bpf_prog_pack_free(void *ptr, u32 size)
1044{
1045 struct bpf_prog_pack *pack = NULL, *tmp;
1046 unsigned int nbits;
1047 unsigned long pos;
1048
1049 mutex_lock(&pack_mutex);
1050 if (size > BPF_PROG_PACK_SIZE) {
1051 bpf_jit_free_exec(ptr);
1052 goto out;
1053 }
1054
1055 list_for_each_entry(tmp, &pack_list, list) {
1056 if (ptr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > ptr) {
1057 pack = tmp;
1058 break;
1059 }
1060 }
1061
1062 if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
1063 goto out;
1064
1065 nbits = BPF_PROG_SIZE_TO_NBITS(size);
1066 pos = ((unsigned long)ptr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
1067
1068 WARN_ONCE(bpf_arch_text_invalidate(ptr, size),
1069 "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
1070
1071 bitmap_clear(pack->bitmap, pos, nbits);
1072
1073 if (static_branch_unlikely(&bpf_pred_flush_enabled))
1074 pack->arch_flush_needed = true;
1075 if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
1076 BPF_PROG_CHUNK_COUNT, 0) == 0) {
1077 list_del(&pack->list);
1078 bpf_jit_free_exec(pack->ptr);
1079 kfree(pack);
1080 }
1081out:
1082 mutex_unlock(&pack_mutex);
1083}
1084
1085static atomic_long_t bpf_jit_current;
1086
1087/* Can be overridden by an arch's JIT compiler if it has a custom,
1088 * dedicated BPF backend memory area, or if neither of the two
1089 * below apply.
1090 */
1091u64 __weak bpf_jit_alloc_exec_limit(void)
1092{
1093#if defined(MODULES_VADDR)
1094 return MODULES_END - MODULES_VADDR;
1095#else
1096 return VMALLOC_END - VMALLOC_START;
1097#endif
1098}
1099
1100static int __init bpf_jit_charge_init(void)
1101{
1102 /* Only used as heuristic here to derive limit. */
1103 bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
1104 bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 1,
1105 PAGE_SIZE), LONG_MAX);
1106 return 0;
1107}
1108pure_initcall(bpf_jit_charge_init);
1109
1110int bpf_jit_charge_modmem(u32 size)
1111{
1112 if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
1113 if (!bpf_capable()) {
1114 atomic_long_sub(size, &bpf_jit_current);
1115 return -EPERM;
1116 }
1117 }
1118
1119 return 0;
1120}
1121
1122void bpf_jit_uncharge_modmem(u32 size)
1123{
1124 atomic_long_sub(size, &bpf_jit_current);
1125}
1126
1127void *bpf_jit_alloc_exec(unsigned long size)
1128{
1129 return execmem_alloc(EXECMEM_BPF, size);
1130}
1131
1132void bpf_jit_free_exec(void *addr)
1133{
1134 execmem_free(addr);
1135}
1136
1137struct bpf_binary_header *
1138bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1139 unsigned int alignment,
1140 bpf_jit_fill_hole_t bpf_fill_ill_insns)
1141{
1142 struct bpf_binary_header *hdr;
1143 u32 size, hole, start;
1144
1145 WARN_ON_ONCE(!is_power_of_2(alignment) ||
1146 alignment > BPF_IMAGE_ALIGNMENT);
1147
1148 /* Most of BPF filters are really small, but if some of them
1149 * fill a page, allow at least 128 extra bytes to insert a
1150 * random section of illegal instructions.
1151 */
1152 size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
1153
1154 if (bpf_jit_charge_modmem(size))
1155 return NULL;
1156 hdr = bpf_jit_alloc_exec(size);
1157 if (!hdr) {
1158 bpf_jit_uncharge_modmem(size);
1159 return NULL;
1160 }
1161
1162 /* Fill space with illegal/arch-dep instructions. */
1163 bpf_fill_ill_insns(hdr, size);
1164
1165 hdr->size = size;
1166 hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
1167 PAGE_SIZE - sizeof(*hdr));
1168 start = get_random_u32_below(hole) & ~(alignment - 1);
1169
1170 /* Leave a random number of instructions before BPF code. */
1171 *image_ptr = &hdr->image[start];
1172
1173 return hdr;
1174}
1175
1176void bpf_jit_binary_free(struct bpf_binary_header *hdr)
1177{
1178 u32 size = hdr->size;
1179
1180 bpf_jit_free_exec(hdr);
1181 bpf_jit_uncharge_modmem(size);
1182}
1183
1184/* Allocate jit binary from bpf_prog_pack allocator.
1185 * Since the allocated memory is RO+X, the JIT engine cannot write directly
1186 * to the memory. To solve this problem, a RW buffer is also allocated at
1187 * as the same time. The JIT engine should calculate offsets based on the
1188 * RO memory address, but write JITed program to the RW buffer. Once the
1189 * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
1190 * the JITed program to the RO memory.
1191 */
1192struct bpf_binary_header *
1193bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
1194 unsigned int alignment,
1195 struct bpf_binary_header **rw_header,
1196 u8 **rw_image,
1197 bpf_jit_fill_hole_t bpf_fill_ill_insns,
1198 bool was_classic)
1199{
1200 struct bpf_binary_header *ro_header;
1201 u32 size, hole, start;
1202
1203 WARN_ON_ONCE(!is_power_of_2(alignment) ||
1204 alignment > BPF_IMAGE_ALIGNMENT);
1205
1206 /* add 16 bytes for a random section of illegal instructions */
1207 size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
1208
1209 if (bpf_jit_charge_modmem(size))
1210 return NULL;
1211 ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns, was_classic);
1212 if (!ro_header) {
1213 bpf_jit_uncharge_modmem(size);
1214 return NULL;
1215 }
1216
1217 *rw_header = kvmalloc(size, GFP_KERNEL);
1218 if (!*rw_header) {
1219 bpf_prog_pack_free(ro_header, size);
1220 bpf_jit_uncharge_modmem(size);
1221 return NULL;
1222 }
1223
1224 /* Fill space with illegal/arch-dep instructions. */
1225 bpf_fill_ill_insns(*rw_header, size);
1226 (*rw_header)->size = size;
1227
1228 hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
1229 BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
1230 start = get_random_u32_below(hole) & ~(alignment - 1);
1231
1232 *image_ptr = &ro_header->image[start];
1233 *rw_image = &(*rw_header)->image[start];
1234
1235 return ro_header;
1236}
1237
1238/* Copy JITed text from rw_header to its final location, the ro_header. */
1239int bpf_jit_binary_pack_finalize(struct bpf_binary_header *ro_header,
1240 struct bpf_binary_header *rw_header)
1241{
1242 void *ptr;
1243
1244 ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
1245
1246 kvfree(rw_header);
1247
1248 if (IS_ERR(ptr)) {
1249 bpf_prog_pack_free(ro_header, ro_header->size);
1250 return PTR_ERR(ptr);
1251 }
1252 return 0;
1253}
1254
1255/* bpf_jit_binary_pack_free is called in two different scenarios:
1256 * 1) when the program is freed after;
1257 * 2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
1258 * For case 2), we need to free both the RO memory and the RW buffer.
1259 *
1260 * bpf_jit_binary_pack_free requires proper ro_header->size. However,
1261 * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
1262 * must be set with either bpf_jit_binary_pack_finalize (normal path) or
1263 * bpf_arch_text_copy (when jit fails).
1264 */
1265void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
1266 struct bpf_binary_header *rw_header)
1267{
1268 u32 size = ro_header->size;
1269
1270 bpf_prog_pack_free(ro_header, size);
1271 kvfree(rw_header);
1272 bpf_jit_uncharge_modmem(size);
1273}
1274
1275struct bpf_binary_header *
1276bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
1277{
1278 unsigned long real_start = (unsigned long)fp->bpf_func;
1279 unsigned long addr;
1280
1281 addr = real_start & BPF_PROG_CHUNK_MASK;
1282 return (void *)addr;
1283}
1284
1285static inline struct bpf_binary_header *
1286bpf_jit_binary_hdr(const struct bpf_prog *fp)
1287{
1288 unsigned long real_start = (unsigned long)fp->bpf_func;
1289 unsigned long addr;
1290
1291 addr = real_start & PAGE_MASK;
1292 return (void *)addr;
1293}
1294
1295/* This symbol is only overridden by archs that have different
1296 * requirements than the usual eBPF JITs, f.e. when they only
1297 * implement cBPF JIT, do not set images read-only, etc.
1298 */
1299void __weak bpf_jit_free(struct bpf_prog *fp)
1300{
1301 if (fp->jited) {
1302 struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
1303
1304 bpf_jit_binary_free(hdr);
1305 WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
1306 }
1307
1308 bpf_prog_unlock_free(fp);
1309}
1310
1311int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1312 const struct bpf_insn *insn, bool extra_pass,
1313 u64 *func_addr, bool *func_addr_fixed)
1314{
1315 s16 off = insn->off;
1316 s32 imm = insn->imm;
1317 u8 *addr;
1318 int err;
1319
1320 *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1321 if (!*func_addr_fixed) {
1322 /* Place-holder address till the last pass has collected
1323 * all addresses for JITed subprograms in which case we
1324 * can pick them up from prog->aux.
1325 */
1326 if (!extra_pass)
1327 addr = NULL;
1328 else if (prog->aux->func &&
1329 off >= 0 && off < prog->aux->real_func_cnt)
1330 addr = (u8 *)prog->aux->func[off]->bpf_func;
1331 else
1332 return -EINVAL;
1333 } else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL &&
1334 bpf_jit_supports_far_kfunc_call()) {
1335 err = bpf_get_kfunc_addr(prog, insn->imm, insn->off, &addr);
1336 if (err)
1337 return err;
1338 } else {
1339 /* Address of a BPF helper call. Since part of the core
1340 * kernel, it's always at a fixed location. __bpf_call_base
1341 * and the helper with imm relative to it are both in core
1342 * kernel.
1343 */
1344 addr = (u8 *)__bpf_call_base + imm;
1345 }
1346
1347 *func_addr = (unsigned long)addr;
1348 return 0;
1349}
1350
1351const char *bpf_jit_get_prog_name(struct bpf_prog *prog)
1352{
1353 if (prog->aux->ksym.prog)
1354 return prog->aux->ksym.name;
1355 return prog->aux->name;
1356}
1357
1358static int bpf_jit_blind_insn(const struct bpf_insn *from,
1359 const struct bpf_insn *aux,
1360 struct bpf_insn *to_buff,
1361 bool emit_zext)
1362{
1363 struct bpf_insn *to = to_buff;
1364 u32 imm_rnd = get_random_u32();
1365 int off;
1366
1367 BUILD_BUG_ON(BPF_REG_PARAMS + 2 != MAX_BPF_JIT_REG);
1368 BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG);
1369
1370 /* Constraints on AX register:
1371 *
1372 * AX register is inaccessible from user space. It is mapped in
1373 * all JITs, and used here for constant blinding rewrites. It is
1374 * typically "stateless" meaning its contents are only valid within
1375 * the executed instruction, but not across several instructions.
1376 * There are a few exceptions however which are further detailed
1377 * below.
1378 *
1379 * Constant blinding is only used by JITs, not in the interpreter.
1380 * The interpreter uses AX in some occasions as a local temporary
1381 * register e.g. in DIV or MOD instructions.
1382 *
1383 * In restricted circumstances, the verifier can also use the AX
1384 * register for rewrites as long as they do not interfere with
1385 * the above cases!
1386 */
1387 if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1388 goto out;
1389
1390 if (from->imm == 0 &&
1391 (from->code == (BPF_ALU | BPF_MOV | BPF_K) ||
1392 from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1393 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1394 goto out;
1395 }
1396
1397 switch (from->code) {
1398 case BPF_ALU | BPF_ADD | BPF_K:
1399 case BPF_ALU | BPF_SUB | BPF_K:
1400 case BPF_ALU | BPF_AND | BPF_K:
1401 case BPF_ALU | BPF_OR | BPF_K:
1402 case BPF_ALU | BPF_XOR | BPF_K:
1403 case BPF_ALU | BPF_MUL | BPF_K:
1404 case BPF_ALU | BPF_MOV | BPF_K:
1405 case BPF_ALU | BPF_DIV | BPF_K:
1406 case BPF_ALU | BPF_MOD | BPF_K:
1407 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1408 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1409 *to++ = BPF_ALU32_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1410 break;
1411
1412 case BPF_ALU64 | BPF_ADD | BPF_K:
1413 case BPF_ALU64 | BPF_SUB | BPF_K:
1414 case BPF_ALU64 | BPF_AND | BPF_K:
1415 case BPF_ALU64 | BPF_OR | BPF_K:
1416 case BPF_ALU64 | BPF_XOR | BPF_K:
1417 case BPF_ALU64 | BPF_MUL | BPF_K:
1418 case BPF_ALU64 | BPF_MOV | BPF_K:
1419 case BPF_ALU64 | BPF_DIV | BPF_K:
1420 case BPF_ALU64 | BPF_MOD | BPF_K:
1421 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1422 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1423 *to++ = BPF_ALU64_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1424 break;
1425
1426 case BPF_JMP | BPF_JEQ | BPF_K:
1427 case BPF_JMP | BPF_JNE | BPF_K:
1428 case BPF_JMP | BPF_JGT | BPF_K:
1429 case BPF_JMP | BPF_JLT | BPF_K:
1430 case BPF_JMP | BPF_JGE | BPF_K:
1431 case BPF_JMP | BPF_JLE | BPF_K:
1432 case BPF_JMP | BPF_JSGT | BPF_K:
1433 case BPF_JMP | BPF_JSLT | BPF_K:
1434 case BPF_JMP | BPF_JSGE | BPF_K:
1435 case BPF_JMP | BPF_JSLE | BPF_K:
1436 case BPF_JMP | BPF_JSET | BPF_K:
1437 /* Accommodate for extra offset in case of a backjump. */
1438 off = from->off;
1439 if (off < 0)
1440 off -= 2;
1441 if (off < S16_MIN)
1442 return -ERANGE;
1443 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1444 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1445 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1446 break;
1447
1448 case BPF_JMP32 | BPF_JEQ | BPF_K:
1449 case BPF_JMP32 | BPF_JNE | BPF_K:
1450 case BPF_JMP32 | BPF_JGT | BPF_K:
1451 case BPF_JMP32 | BPF_JLT | BPF_K:
1452 case BPF_JMP32 | BPF_JGE | BPF_K:
1453 case BPF_JMP32 | BPF_JLE | BPF_K:
1454 case BPF_JMP32 | BPF_JSGT | BPF_K:
1455 case BPF_JMP32 | BPF_JSLT | BPF_K:
1456 case BPF_JMP32 | BPF_JSGE | BPF_K:
1457 case BPF_JMP32 | BPF_JSLE | BPF_K:
1458 case BPF_JMP32 | BPF_JSET | BPF_K:
1459 /* Accommodate for extra offset in case of a backjump. */
1460 off = from->off;
1461 if (off < 0)
1462 off -= 2;
1463 if (off < S16_MIN)
1464 return -ERANGE;
1465 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1466 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1467 *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1468 off);
1469 break;
1470
1471 case BPF_LD | BPF_IMM | BPF_DW:
1472 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1473 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1474 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1475 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1476 break;
1477 case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1478 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1479 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1480 if (emit_zext)
1481 *to++ = BPF_ZEXT_REG(BPF_REG_AX);
1482 *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX);
1483 break;
1484
1485 case BPF_ST | BPF_MEM | BPF_DW:
1486 case BPF_ST | BPF_MEM | BPF_W:
1487 case BPF_ST | BPF_MEM | BPF_H:
1488 case BPF_ST | BPF_MEM | BPF_B:
1489 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1490 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1491 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1492 break;
1493
1494 case BPF_ST | BPF_PROBE_MEM32 | BPF_DW:
1495 case BPF_ST | BPF_PROBE_MEM32 | BPF_W:
1496 case BPF_ST | BPF_PROBE_MEM32 | BPF_H:
1497 case BPF_ST | BPF_PROBE_MEM32 | BPF_B:
1498 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^
1499 from->imm);
1500 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1501 /*
1502 * Cannot use BPF_STX_MEM() macro here as it
1503 * hardcodes BPF_MEM mode, losing PROBE_MEM32
1504 * and breaking arena addressing in the JIT.
1505 */
1506 *to++ = (struct bpf_insn) {
1507 .code = BPF_STX | BPF_PROBE_MEM32 |
1508 BPF_SIZE(from->code),
1509 .dst_reg = from->dst_reg,
1510 .src_reg = BPF_REG_AX,
1511 .off = from->off,
1512 };
1513 break;
1514 }
1515out:
1516 return to - to_buff;
1517}
1518
1519static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1520 gfp_t gfp_extra_flags)
1521{
1522 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1523 struct bpf_prog *fp;
1524
1525 fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1526 if (fp != NULL) {
1527 /* aux->prog still points to the fp_other one, so
1528 * when promoting the clone to the real program,
1529 * this still needs to be adapted.
1530 */
1531 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1532 }
1533
1534 return fp;
1535}
1536
1537static void bpf_prog_clone_free(struct bpf_prog *fp)
1538{
1539 /* aux was stolen by the other clone, so we cannot free
1540 * it from this path! It will be freed eventually by the
1541 * other program on release.
1542 *
1543 * At this point, we don't need a deferred release since
1544 * clone is guaranteed to not be locked.
1545 */
1546 fp->aux = NULL;
1547 fp->stats = NULL;
1548 fp->active = NULL;
1549 __bpf_prog_free(fp);
1550}
1551
1552void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1553{
1554 /* We have to repoint aux->prog to self, as we don't
1555 * know whether fp here is the clone or the original.
1556 */
1557 fp->aux->prog = fp;
1558 if (fp->aux->offload)
1559 fp->aux->offload->prog = fp;
1560 bpf_prog_clone_free(fp_other);
1561}
1562
1563/*
1564 * Now this function is used only to blind the main prog and must be invoked only when
1565 * bpf_prog_need_blind() returns true.
1566 */
1567struct bpf_prog *bpf_jit_blind_constants(struct bpf_verifier_env *env, struct bpf_prog *prog)
1568{
1569 struct bpf_insn insn_buff[16], aux[2];
1570 struct bpf_prog *clone, *tmp;
1571 int insn_delta, insn_cnt;
1572 struct bpf_insn *insn;
1573 int i, rewritten;
1574
1575 if (WARN_ON_ONCE(env && env->prog != prog))
1576 return ERR_PTR(-EINVAL);
1577
1578 clone = bpf_prog_clone_create(prog, GFP_USER);
1579 if (!clone)
1580 return ERR_PTR(-ENOMEM);
1581
1582 /* make sure bpf_patch_insn_data() patches the correct prog */
1583 if (env)
1584 env->prog = clone;
1585
1586 insn_cnt = clone->len;
1587 insn = clone->insnsi;
1588
1589 for (i = 0; i < insn_cnt; i++, insn++) {
1590 if (bpf_pseudo_func(insn)) {
1591 /* ld_imm64 with an address of bpf subprog is not
1592 * a user controlled constant. Don't randomize it,
1593 * since it will conflict with jit_subprogs() logic.
1594 */
1595 insn++;
1596 i++;
1597 continue;
1598 }
1599
1600 /* We temporarily need to hold the original ld64 insn
1601 * so that we can still access the first part in the
1602 * second blinding run.
1603 */
1604 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1605 insn[1].code == 0)
1606 memcpy(aux, insn, sizeof(aux));
1607
1608 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1609 clone->aux->verifier_zext);
1610 if (!rewritten)
1611 continue;
1612
1613 if (rewritten < 0)
1614 tmp = ERR_PTR(rewritten);
1615 else if (env)
1616 tmp = bpf_patch_insn_data(env, i, insn_buff, rewritten);
1617 else
1618 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1619
1620 if (IS_ERR_OR_NULL(tmp)) {
1621 if (env)
1622 /* restore the original prog */
1623 env->prog = prog;
1624 /* Patching may have repointed aux->prog during
1625 * realloc from the original one, so we need to
1626 * fix it up here on error.
1627 */
1628 bpf_jit_prog_release_other(prog, clone);
1629 if (env && fatal_signal_pending(current))
1630 return ERR_PTR(-EINTR);
1631 return IS_ERR(tmp) ? tmp : ERR_PTR(-ENOMEM);
1632 }
1633
1634 clone = tmp;
1635 insn_delta = rewritten - 1;
1636
1637 if (env)
1638 env->prog = clone;
1639
1640 /* Walk new program and skip insns we just inserted. */
1641 insn = clone->insnsi + i + insn_delta;
1642 insn_cnt += insn_delta;
1643 i += insn_delta;
1644 }
1645
1646 clone->blinded = 1;
1647 return clone;
1648}
1649
1650bool bpf_insn_is_indirect_target(const struct bpf_verifier_env *env, const struct bpf_prog *prog,
1651 int insn_idx)
1652{
1653 if (!env)
1654 return false;
1655 insn_idx += prog->aux->subprog_start;
1656 return env->insn_aux_data[insn_idx].indirect_target;
1657}
1658
1659u16 bpf_out_stack_arg_cnt(const struct bpf_verifier_env *env, const struct bpf_prog *prog)
1660{
1661 const struct bpf_subprog_info *sub;
1662
1663 if (!env)
1664 return 0;
1665 sub = &env->subprog_info[prog->aux->func_idx];
1666 return sub->stack_arg_cnt - bpf_in_stack_arg_cnt(sub);
1667}
1668#endif /* CONFIG_BPF_JIT */
1669
1670/* Base function for offset calculation. Needs to go into .text section,
1671 * therefore keeping it non-static as well; will also be used by JITs
1672 * anyway later on, so do not let the compiler omit it. This also needs
1673 * to go into kallsyms for correlation from e.g. bpftool, so naming
1674 * must not change.
1675 */
1676noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1677{
1678 return 0;
1679}
1680EXPORT_SYMBOL_GPL(__bpf_call_base);
1681
1682/* All UAPI available opcodes. */
1683#define BPF_INSN_MAP(INSN_2, INSN_3) \
1684 /* 32 bit ALU operations. */ \
1685 /* Register based. */ \
1686 INSN_3(ALU, ADD, X), \
1687 INSN_3(ALU, SUB, X), \
1688 INSN_3(ALU, AND, X), \
1689 INSN_3(ALU, OR, X), \
1690 INSN_3(ALU, LSH, X), \
1691 INSN_3(ALU, RSH, X), \
1692 INSN_3(ALU, XOR, X), \
1693 INSN_3(ALU, MUL, X), \
1694 INSN_3(ALU, MOV, X), \
1695 INSN_3(ALU, ARSH, X), \
1696 INSN_3(ALU, DIV, X), \
1697 INSN_3(ALU, MOD, X), \
1698 INSN_2(ALU, NEG), \
1699 INSN_3(ALU, END, TO_BE), \
1700 INSN_3(ALU, END, TO_LE), \
1701 /* Immediate based. */ \
1702 INSN_3(ALU, ADD, K), \
1703 INSN_3(ALU, SUB, K), \
1704 INSN_3(ALU, AND, K), \
1705 INSN_3(ALU, OR, K), \
1706 INSN_3(ALU, LSH, K), \
1707 INSN_3(ALU, RSH, K), \
1708 INSN_3(ALU, XOR, K), \
1709 INSN_3(ALU, MUL, K), \
1710 INSN_3(ALU, MOV, K), \
1711 INSN_3(ALU, ARSH, K), \
1712 INSN_3(ALU, DIV, K), \
1713 INSN_3(ALU, MOD, K), \
1714 /* 64 bit ALU operations. */ \
1715 /* Register based. */ \
1716 INSN_3(ALU64, ADD, X), \
1717 INSN_3(ALU64, SUB, X), \
1718 INSN_3(ALU64, AND, X), \
1719 INSN_3(ALU64, OR, X), \
1720 INSN_3(ALU64, LSH, X), \
1721 INSN_3(ALU64, RSH, X), \
1722 INSN_3(ALU64, XOR, X), \
1723 INSN_3(ALU64, MUL, X), \
1724 INSN_3(ALU64, MOV, X), \
1725 INSN_3(ALU64, ARSH, X), \
1726 INSN_3(ALU64, DIV, X), \
1727 INSN_3(ALU64, MOD, X), \
1728 INSN_2(ALU64, NEG), \
1729 INSN_3(ALU64, END, TO_LE), \
1730 /* Immediate based. */ \
1731 INSN_3(ALU64, ADD, K), \
1732 INSN_3(ALU64, SUB, K), \
1733 INSN_3(ALU64, AND, K), \
1734 INSN_3(ALU64, OR, K), \
1735 INSN_3(ALU64, LSH, K), \
1736 INSN_3(ALU64, RSH, K), \
1737 INSN_3(ALU64, XOR, K), \
1738 INSN_3(ALU64, MUL, K), \
1739 INSN_3(ALU64, MOV, K), \
1740 INSN_3(ALU64, ARSH, K), \
1741 INSN_3(ALU64, DIV, K), \
1742 INSN_3(ALU64, MOD, K), \
1743 /* Call instruction. */ \
1744 INSN_2(JMP, CALL), \
1745 /* Exit instruction. */ \
1746 INSN_2(JMP, EXIT), \
1747 /* 32-bit Jump instructions. */ \
1748 /* Register based. */ \
1749 INSN_3(JMP32, JEQ, X), \
1750 INSN_3(JMP32, JNE, X), \
1751 INSN_3(JMP32, JGT, X), \
1752 INSN_3(JMP32, JLT, X), \
1753 INSN_3(JMP32, JGE, X), \
1754 INSN_3(JMP32, JLE, X), \
1755 INSN_3(JMP32, JSGT, X), \
1756 INSN_3(JMP32, JSLT, X), \
1757 INSN_3(JMP32, JSGE, X), \
1758 INSN_3(JMP32, JSLE, X), \
1759 INSN_3(JMP32, JSET, X), \
1760 /* Immediate based. */ \
1761 INSN_3(JMP32, JEQ, K), \
1762 INSN_3(JMP32, JNE, K), \
1763 INSN_3(JMP32, JGT, K), \
1764 INSN_3(JMP32, JLT, K), \
1765 INSN_3(JMP32, JGE, K), \
1766 INSN_3(JMP32, JLE, K), \
1767 INSN_3(JMP32, JSGT, K), \
1768 INSN_3(JMP32, JSLT, K), \
1769 INSN_3(JMP32, JSGE, K), \
1770 INSN_3(JMP32, JSLE, K), \
1771 INSN_3(JMP32, JSET, K), \
1772 /* Jump instructions. */ \
1773 /* Register based. */ \
1774 INSN_3(JMP, JEQ, X), \
1775 INSN_3(JMP, JNE, X), \
1776 INSN_3(JMP, JGT, X), \
1777 INSN_3(JMP, JLT, X), \
1778 INSN_3(JMP, JGE, X), \
1779 INSN_3(JMP, JLE, X), \
1780 INSN_3(JMP, JSGT, X), \
1781 INSN_3(JMP, JSLT, X), \
1782 INSN_3(JMP, JSGE, X), \
1783 INSN_3(JMP, JSLE, X), \
1784 INSN_3(JMP, JSET, X), \
1785 /* Immediate based. */ \
1786 INSN_3(JMP, JEQ, K), \
1787 INSN_3(JMP, JNE, K), \
1788 INSN_3(JMP, JGT, K), \
1789 INSN_3(JMP, JLT, K), \
1790 INSN_3(JMP, JGE, K), \
1791 INSN_3(JMP, JLE, K), \
1792 INSN_3(JMP, JSGT, K), \
1793 INSN_3(JMP, JSLT, K), \
1794 INSN_3(JMP, JSGE, K), \
1795 INSN_3(JMP, JSLE, K), \
1796 INSN_3(JMP, JSET, K), \
1797 INSN_2(JMP, JA), \
1798 INSN_2(JMP32, JA), \
1799 /* Atomic operations. */ \
1800 INSN_3(STX, ATOMIC, B), \
1801 INSN_3(STX, ATOMIC, H), \
1802 INSN_3(STX, ATOMIC, W), \
1803 INSN_3(STX, ATOMIC, DW), \
1804 /* Store instructions. */ \
1805 /* Register based. */ \
1806 INSN_3(STX, MEM, B), \
1807 INSN_3(STX, MEM, H), \
1808 INSN_3(STX, MEM, W), \
1809 INSN_3(STX, MEM, DW), \
1810 /* Immediate based. */ \
1811 INSN_3(ST, MEM, B), \
1812 INSN_3(ST, MEM, H), \
1813 INSN_3(ST, MEM, W), \
1814 INSN_3(ST, MEM, DW), \
1815 /* Load instructions. */ \
1816 /* Register based. */ \
1817 INSN_3(LDX, MEM, B), \
1818 INSN_3(LDX, MEM, H), \
1819 INSN_3(LDX, MEM, W), \
1820 INSN_3(LDX, MEM, DW), \
1821 INSN_3(LDX, MEMSX, B), \
1822 INSN_3(LDX, MEMSX, H), \
1823 INSN_3(LDX, MEMSX, W), \
1824 /* Immediate based. */ \
1825 INSN_3(LD, IMM, DW)
1826
1827bool bpf_opcode_in_insntable(u8 code)
1828{
1829#define BPF_INSN_2_TBL(x, y) [BPF_##x | BPF_##y] = true
1830#define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1831 static const bool public_insntable[256] = {
1832 [0 ... 255] = false,
1833 /* Now overwrite non-defaults ... */
1834 BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1835 /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1836 [BPF_LD | BPF_ABS | BPF_B] = true,
1837 [BPF_LD | BPF_ABS | BPF_H] = true,
1838 [BPF_LD | BPF_ABS | BPF_W] = true,
1839 [BPF_LD | BPF_IND | BPF_B] = true,
1840 [BPF_LD | BPF_IND | BPF_H] = true,
1841 [BPF_LD | BPF_IND | BPF_W] = true,
1842 [BPF_JMP | BPF_JA | BPF_X] = true,
1843 [BPF_JMP | BPF_JCOND] = true,
1844 };
1845#undef BPF_INSN_3_TBL
1846#undef BPF_INSN_2_TBL
1847 return public_insntable[code];
1848}
1849
1850#ifndef CONFIG_BPF_JIT_ALWAYS_ON
1851/* Absolute value of s32 without undefined behavior for S32_MIN */
1852static u32 abs_s32(s32 x)
1853{
1854 return x >= 0 ? (u32)x : -(u32)x;
1855}
1856
1857static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
1858 const struct bpf_insn *insn);
1859
1860/**
1861 * ___bpf_prog_run - run eBPF program on a given context
1862 * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1863 * @insn: is the array of eBPF instructions
1864 *
1865 * Decode and execute eBPF instructions.
1866 *
1867 * Return: whatever value is in %BPF_R0 at program exit
1868 */
1869static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1870{
1871#define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y
1872#define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1873 static const void * const jumptable[256] __annotate_jump_table = {
1874 [0 ... 255] = &&default_label,
1875 /* Now overwrite non-defaults ... */
1876 BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1877 /* Non-UAPI available opcodes. */
1878 [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1879 [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1880 [BPF_ST | BPF_NOSPEC] = &&ST_NOSPEC,
1881 [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1882 [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1883 [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1884 [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1885 [BPF_LDX | BPF_PROBE_MEMSX | BPF_B] = &&LDX_PROBE_MEMSX_B,
1886 [BPF_LDX | BPF_PROBE_MEMSX | BPF_H] = &&LDX_PROBE_MEMSX_H,
1887 [BPF_LDX | BPF_PROBE_MEMSX | BPF_W] = &&LDX_PROBE_MEMSX_W,
1888 };
1889#undef BPF_INSN_3_LBL
1890#undef BPF_INSN_2_LBL
1891 u32 tail_call_cnt = 0;
1892
1893#define CONT ({ insn++; goto select_insn; })
1894#define CONT_JMP ({ insn++; goto select_insn; })
1895
1896select_insn:
1897 goto *jumptable[insn->code];
1898
1899 /* Explicitly mask the register-based shift amounts with 63 or 31
1900 * to avoid undefined behavior. Normally this won't affect the
1901 * generated code, for example, in case of native 64 bit archs such
1902 * as x86-64 or arm64, the compiler is optimizing the AND away for
1903 * the interpreter. In case of JITs, each of the JIT backends compiles
1904 * the BPF shift operations to machine instructions which produce
1905 * implementation-defined results in such a case; the resulting
1906 * contents of the register may be arbitrary, but program behaviour
1907 * as a whole remains defined. In other words, in case of JIT backends,
1908 * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1909 */
1910 /* ALU (shifts) */
1911#define SHT(OPCODE, OP) \
1912 ALU64_##OPCODE##_X: \
1913 DST = DST OP (SRC & 63); \
1914 CONT; \
1915 ALU_##OPCODE##_X: \
1916 DST = (u32) DST OP ((u32) SRC & 31); \
1917 CONT; \
1918 ALU64_##OPCODE##_K: \
1919 DST = DST OP IMM; \
1920 CONT; \
1921 ALU_##OPCODE##_K: \
1922 DST = (u32) DST OP (u32) IMM; \
1923 CONT;
1924 /* ALU (rest) */
1925#define ALU(OPCODE, OP) \
1926 ALU64_##OPCODE##_X: \
1927 DST = DST OP SRC; \
1928 CONT; \
1929 ALU_##OPCODE##_X: \
1930 DST = (u32) DST OP (u32) SRC; \
1931 CONT; \
1932 ALU64_##OPCODE##_K: \
1933 DST = DST OP IMM; \
1934 CONT; \
1935 ALU_##OPCODE##_K: \
1936 DST = (u32) DST OP (u32) IMM; \
1937 CONT;
1938 ALU(ADD, +)
1939 ALU(SUB, -)
1940 ALU(AND, &)
1941 ALU(OR, |)
1942 ALU(XOR, ^)
1943 ALU(MUL, *)
1944 SHT(LSH, <<)
1945 SHT(RSH, >>)
1946#undef SHT
1947#undef ALU
1948 ALU_NEG:
1949 DST = (u32) -DST;
1950 CONT;
1951 ALU64_NEG:
1952 DST = -DST;
1953 CONT;
1954 ALU_MOV_X:
1955 switch (OFF) {
1956 case 0:
1957 DST = (u32) SRC;
1958 break;
1959 case 8:
1960 DST = (u32)(s8) SRC;
1961 break;
1962 case 16:
1963 DST = (u32)(s16) SRC;
1964 break;
1965 }
1966 CONT;
1967 ALU_MOV_K:
1968 DST = (u32) IMM;
1969 CONT;
1970 ALU64_MOV_X:
1971 switch (OFF) {
1972 case 0:
1973 DST = SRC;
1974 break;
1975 case 8:
1976 DST = (s8) SRC;
1977 break;
1978 case 16:
1979 DST = (s16) SRC;
1980 break;
1981 case 32:
1982 DST = (s32) SRC;
1983 break;
1984 }
1985 CONT;
1986 ALU64_MOV_K:
1987 DST = IMM;
1988 CONT;
1989 LD_IMM_DW:
1990 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1991 insn++;
1992 CONT;
1993 ALU_ARSH_X:
1994 DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1995 CONT;
1996 ALU_ARSH_K:
1997 DST = (u64) (u32) (((s32) DST) >> IMM);
1998 CONT;
1999 ALU64_ARSH_X:
2000 (*(s64 *) &DST) >>= (SRC & 63);
2001 CONT;
2002 ALU64_ARSH_K:
2003 (*(s64 *) &DST) >>= IMM;
2004 CONT;
2005 ALU64_MOD_X:
2006 switch (OFF) {
2007 case 0:
2008 div64_u64_rem(DST, SRC, &AX);
2009 DST = AX;
2010 break;
2011 case 1:
2012 AX = div64_s64(DST, SRC);
2013 DST = DST - AX * SRC;
2014 break;
2015 }
2016 CONT;
2017 ALU_MOD_X:
2018 switch (OFF) {
2019 case 0:
2020 AX = (u32) DST;
2021 DST = do_div(AX, (u32) SRC);
2022 break;
2023 case 1:
2024 AX = abs_s32((s32)DST);
2025 AX = do_div(AX, abs_s32((s32)SRC));
2026 if ((s32)DST < 0)
2027 DST = (u32)-AX;
2028 else
2029 DST = (u32)AX;
2030 break;
2031 }
2032 CONT;
2033 ALU64_MOD_K:
2034 switch (OFF) {
2035 case 0:
2036 div64_u64_rem(DST, IMM, &AX);
2037 DST = AX;
2038 break;
2039 case 1:
2040 AX = div64_s64(DST, IMM);
2041 DST = DST - AX * IMM;
2042 break;
2043 }
2044 CONT;
2045 ALU_MOD_K:
2046 switch (OFF) {
2047 case 0:
2048 AX = (u32) DST;
2049 DST = do_div(AX, (u32) IMM);
2050 break;
2051 case 1:
2052 AX = abs_s32((s32)DST);
2053 AX = do_div(AX, abs_s32((s32)IMM));
2054 if ((s32)DST < 0)
2055 DST = (u32)-AX;
2056 else
2057 DST = (u32)AX;
2058 break;
2059 }
2060 CONT;
2061 ALU64_DIV_X:
2062 switch (OFF) {
2063 case 0:
2064 DST = div64_u64(DST, SRC);
2065 break;
2066 case 1:
2067 DST = div64_s64(DST, SRC);
2068 break;
2069 }
2070 CONT;
2071 ALU_DIV_X:
2072 switch (OFF) {
2073 case 0:
2074 AX = (u32) DST;
2075 do_div(AX, (u32) SRC);
2076 DST = (u32) AX;
2077 break;
2078 case 1:
2079 AX = abs_s32((s32)DST);
2080 do_div(AX, abs_s32((s32)SRC));
2081 if (((s32)DST < 0) == ((s32)SRC < 0))
2082 DST = (u32)AX;
2083 else
2084 DST = (u32)-AX;
2085 break;
2086 }
2087 CONT;
2088 ALU64_DIV_K:
2089 switch (OFF) {
2090 case 0:
2091 DST = div64_u64(DST, IMM);
2092 break;
2093 case 1:
2094 DST = div64_s64(DST, IMM);
2095 break;
2096 }
2097 CONT;
2098 ALU_DIV_K:
2099 switch (OFF) {
2100 case 0:
2101 AX = (u32) DST;
2102 do_div(AX, (u32) IMM);
2103 DST = (u32) AX;
2104 break;
2105 case 1:
2106 AX = abs_s32((s32)DST);
2107 do_div(AX, abs_s32((s32)IMM));
2108 if (((s32)DST < 0) == ((s32)IMM < 0))
2109 DST = (u32)AX;
2110 else
2111 DST = (u32)-AX;
2112 break;
2113 }
2114 CONT;
2115 ALU_END_TO_BE:
2116 switch (IMM) {
2117 case 16:
2118 DST = (__force u16) cpu_to_be16(DST);
2119 break;
2120 case 32:
2121 DST = (__force u32) cpu_to_be32(DST);
2122 break;
2123 case 64:
2124 DST = (__force u64) cpu_to_be64(DST);
2125 break;
2126 }
2127 CONT;
2128 ALU_END_TO_LE:
2129 switch (IMM) {
2130 case 16:
2131 DST = (__force u16) cpu_to_le16(DST);
2132 break;
2133 case 32:
2134 DST = (__force u32) cpu_to_le32(DST);
2135 break;
2136 case 64:
2137 DST = (__force u64) cpu_to_le64(DST);
2138 break;
2139 }
2140 CONT;
2141 ALU64_END_TO_LE:
2142 switch (IMM) {
2143 case 16:
2144 DST = (__force u16) __swab16(DST);
2145 break;
2146 case 32:
2147 DST = (__force u32) __swab32(DST);
2148 break;
2149 case 64:
2150 DST = (__force u64) __swab64(DST);
2151 break;
2152 }
2153 CONT;
2154
2155 /* CALL */
2156 JMP_CALL:
2157 /* Function call scratches BPF_R1-BPF_R5 registers,
2158 * preserves BPF_R6-BPF_R9, and stores return value
2159 * into BPF_R0.
2160 */
2161 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
2162 BPF_R4, BPF_R5);
2163 CONT;
2164
2165 JMP_CALL_ARGS:
2166 BPF_R0 = interpreters_args[insn->off](BPF_R1, BPF_R2, BPF_R3,
2167 BPF_R4, BPF_R5,
2168 insn + insn->imm + 1);
2169 CONT;
2170
2171 JMP_TAIL_CALL: {
2172 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
2173 struct bpf_array *array = container_of(map, struct bpf_array, map);
2174 struct bpf_prog *prog;
2175 u32 index = BPF_R3;
2176
2177 if (unlikely(index >= array->map.max_entries))
2178 goto out;
2179
2180 if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
2181 goto out;
2182
2183 prog = READ_ONCE(array->ptrs[index]);
2184 if (!prog)
2185 goto out;
2186
2187 tail_call_cnt++;
2188
2189 /* ARG1 at this point is guaranteed to point to CTX from
2190 * the verifier side due to the fact that the tail call is
2191 * handled like a helper, that is, bpf_tail_call_proto,
2192 * where arg1_type is ARG_PTR_TO_CTX.
2193 */
2194 insn = prog->insnsi;
2195 goto select_insn;
2196out:
2197 CONT;
2198 }
2199 JMP_JA:
2200 insn += insn->off;
2201 CONT;
2202 JMP32_JA:
2203 insn += insn->imm;
2204 CONT;
2205 JMP_EXIT:
2206 return BPF_R0;
2207 /* JMP */
2208#define COND_JMP(SIGN, OPCODE, CMP_OP) \
2209 JMP_##OPCODE##_X: \
2210 if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) { \
2211 insn += insn->off; \
2212 CONT_JMP; \
2213 } \
2214 CONT; \
2215 JMP32_##OPCODE##_X: \
2216 if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) { \
2217 insn += insn->off; \
2218 CONT_JMP; \
2219 } \
2220 CONT; \
2221 JMP_##OPCODE##_K: \
2222 if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) { \
2223 insn += insn->off; \
2224 CONT_JMP; \
2225 } \
2226 CONT; \
2227 JMP32_##OPCODE##_K: \
2228 if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) { \
2229 insn += insn->off; \
2230 CONT_JMP; \
2231 } \
2232 CONT;
2233 COND_JMP(u, JEQ, ==)
2234 COND_JMP(u, JNE, !=)
2235 COND_JMP(u, JGT, >)
2236 COND_JMP(u, JLT, <)
2237 COND_JMP(u, JGE, >=)
2238 COND_JMP(u, JLE, <=)
2239 COND_JMP(u, JSET, &)
2240 COND_JMP(s, JSGT, >)
2241 COND_JMP(s, JSLT, <)
2242 COND_JMP(s, JSGE, >=)
2243 COND_JMP(s, JSLE, <=)
2244#undef COND_JMP
2245 /* ST, STX and LDX*/
2246 ST_NOSPEC:
2247 /* Speculation barrier for mitigating Speculative Store Bypass,
2248 * Bounds-Check Bypass and Type Confusion. In case of arm64, we
2249 * rely on the firmware mitigation as controlled via the ssbd
2250 * kernel parameter. Whenever the mitigation is enabled, it
2251 * works for all of the kernel code with no need to provide any
2252 * additional instructions here. In case of x86, we use 'lfence'
2253 * insn for mitigation. We reuse preexisting logic from Spectre
2254 * v1 mitigation that happens to produce the required code on
2255 * x86 for v4 as well.
2256 */
2257 barrier_nospec();
2258 CONT;
2259#define LDST(SIZEOP, SIZE) \
2260 STX_MEM_##SIZEOP: \
2261 *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \
2262 CONT; \
2263 ST_MEM_##SIZEOP: \
2264 *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \
2265 CONT; \
2266 LDX_MEM_##SIZEOP: \
2267 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \
2268 CONT; \
2269 LDX_PROBE_MEM_##SIZEOP: \
2270 bpf_probe_read_kernel_common(&DST, sizeof(SIZE), \
2271 (const void *)(long) (SRC + insn->off)); \
2272 DST = *((SIZE *)&DST); \
2273 CONT;
2274
2275 LDST(B, u8)
2276 LDST(H, u16)
2277 LDST(W, u32)
2278 LDST(DW, u64)
2279#undef LDST
2280
2281#define LDSX(SIZEOP, SIZE) \
2282 LDX_MEMSX_##SIZEOP: \
2283 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \
2284 CONT; \
2285 LDX_PROBE_MEMSX_##SIZEOP: \
2286 bpf_probe_read_kernel_common(&DST, sizeof(SIZE), \
2287 (const void *)(long) (SRC + insn->off)); \
2288 DST = *((SIZE *)&DST); \
2289 CONT;
2290
2291 LDSX(B, s8)
2292 LDSX(H, s16)
2293 LDSX(W, s32)
2294#undef LDSX
2295
2296#define ATOMIC_ALU_OP(BOP, KOP) \
2297 case BOP: \
2298 if (BPF_SIZE(insn->code) == BPF_W) \
2299 atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
2300 (DST + insn->off)); \
2301 else if (BPF_SIZE(insn->code) == BPF_DW) \
2302 atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
2303 (DST + insn->off)); \
2304 else \
2305 goto default_label; \
2306 break; \
2307 case BOP | BPF_FETCH: \
2308 if (BPF_SIZE(insn->code) == BPF_W) \
2309 SRC = (u32) atomic_fetch_##KOP( \
2310 (u32) SRC, \
2311 (atomic_t *)(unsigned long) (DST + insn->off)); \
2312 else if (BPF_SIZE(insn->code) == BPF_DW) \
2313 SRC = (u64) atomic64_fetch_##KOP( \
2314 (u64) SRC, \
2315 (atomic64_t *)(unsigned long) (DST + insn->off)); \
2316 else \
2317 goto default_label; \
2318 break;
2319
2320 STX_ATOMIC_DW:
2321 STX_ATOMIC_W:
2322 STX_ATOMIC_H:
2323 STX_ATOMIC_B:
2324 switch (IMM) {
2325 /* Atomic read-modify-write instructions support only W and DW
2326 * size modifiers.
2327 */
2328 ATOMIC_ALU_OP(BPF_ADD, add)
2329 ATOMIC_ALU_OP(BPF_AND, and)
2330 ATOMIC_ALU_OP(BPF_OR, or)
2331 ATOMIC_ALU_OP(BPF_XOR, xor)
2332#undef ATOMIC_ALU_OP
2333
2334 case BPF_XCHG:
2335 if (BPF_SIZE(insn->code) == BPF_W)
2336 SRC = (u32) atomic_xchg(
2337 (atomic_t *)(unsigned long) (DST + insn->off),
2338 (u32) SRC);
2339 else if (BPF_SIZE(insn->code) == BPF_DW)
2340 SRC = (u64) atomic64_xchg(
2341 (atomic64_t *)(unsigned long) (DST + insn->off),
2342 (u64) SRC);
2343 else
2344 goto default_label;
2345 break;
2346 case BPF_CMPXCHG:
2347 if (BPF_SIZE(insn->code) == BPF_W)
2348 BPF_R0 = (u32) atomic_cmpxchg(
2349 (atomic_t *)(unsigned long) (DST + insn->off),
2350 (u32) BPF_R0, (u32) SRC);
2351 else if (BPF_SIZE(insn->code) == BPF_DW)
2352 BPF_R0 = (u64) atomic64_cmpxchg(
2353 (atomic64_t *)(unsigned long) (DST + insn->off),
2354 (u64) BPF_R0, (u64) SRC);
2355 else
2356 goto default_label;
2357 break;
2358 /* Atomic load and store instructions support all size
2359 * modifiers.
2360 */
2361 case BPF_LOAD_ACQ:
2362 switch (BPF_SIZE(insn->code)) {
2363#define LOAD_ACQUIRE(SIZEOP, SIZE) \
2364 case BPF_##SIZEOP: \
2365 DST = (SIZE)smp_load_acquire( \
2366 (SIZE *)(unsigned long)(SRC + insn->off)); \
2367 break;
2368 LOAD_ACQUIRE(B, u8)
2369 LOAD_ACQUIRE(H, u16)
2370 LOAD_ACQUIRE(W, u32)
2371#ifdef CONFIG_64BIT
2372 LOAD_ACQUIRE(DW, u64)
2373#endif
2374#undef LOAD_ACQUIRE
2375 default:
2376 goto default_label;
2377 }
2378 break;
2379 case BPF_STORE_REL:
2380 switch (BPF_SIZE(insn->code)) {
2381#define STORE_RELEASE(SIZEOP, SIZE) \
2382 case BPF_##SIZEOP: \
2383 smp_store_release( \
2384 (SIZE *)(unsigned long)(DST + insn->off), (SIZE)SRC); \
2385 break;
2386 STORE_RELEASE(B, u8)
2387 STORE_RELEASE(H, u16)
2388 STORE_RELEASE(W, u32)
2389#ifdef CONFIG_64BIT
2390 STORE_RELEASE(DW, u64)
2391#endif
2392#undef STORE_RELEASE
2393 default:
2394 goto default_label;
2395 }
2396 break;
2397
2398 default:
2399 goto default_label;
2400 }
2401 CONT;
2402
2403 default_label:
2404 /* If we ever reach this, we have a bug somewhere. Die hard here
2405 * instead of just returning 0; we could be somewhere in a subprog,
2406 * so execution could continue otherwise which we do /not/ want.
2407 *
2408 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2409 */
2410 pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2411 insn->code, insn->imm);
2412 BUG_ON(1);
2413 return 0;
2414}
2415
2416#define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2417#define DEFINE_BPF_PROG_RUN(stack_size) \
2418static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2419{ \
2420 u64 stack[stack_size / sizeof(u64)]; \
2421 u64 regs[MAX_BPF_EXT_REG] = {}; \
2422\
2423 kmsan_unpoison_memory(stack, sizeof(stack)); \
2424 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2425 ARG1 = (u64) (unsigned long) ctx; \
2426 return ___bpf_prog_run(regs, insn); \
2427}
2428
2429#define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2430#define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2431static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2432 const struct bpf_insn *insn) \
2433{ \
2434 u64 stack[stack_size / sizeof(u64)]; \
2435 u64 regs[MAX_BPF_EXT_REG]; \
2436\
2437 kmsan_unpoison_memory(stack, sizeof(stack)); \
2438 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2439 BPF_R1 = r1; \
2440 BPF_R2 = r2; \
2441 BPF_R3 = r3; \
2442 BPF_R4 = r4; \
2443 BPF_R5 = r5; \
2444 return ___bpf_prog_run(regs, insn); \
2445}
2446
2447#define EVAL1(FN, X) FN(X)
2448#define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2449#define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2450#define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2451#define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2452#define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2453
2454EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2455EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2456EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2457
2458EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2459EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2460EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2461
2462#define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2463
2464static unsigned int (*interpreters[])(const void *ctx,
2465 const struct bpf_insn *insn) = {
2466EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2467EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2468EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2469};
2470#undef PROG_NAME_LIST
2471#define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2472static __maybe_unused
2473u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2474 const struct bpf_insn *insn) = {
2475EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2476EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2477EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2478};
2479#undef PROG_NAME_LIST
2480
2481#ifdef CONFIG_BPF_SYSCALL
2482int bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2483{
2484 stack_depth = max_t(u32, stack_depth, 1);
2485 /* Prevent out-of-bounds read to interpreters_args */
2486 if (stack_depth > MAX_BPF_STACK)
2487 return -EINVAL;
2488 insn->off = (round_up(stack_depth, 32) / 32) - 1;
2489 insn->code = BPF_JMP | BPF_CALL_ARGS;
2490 return 0;
2491}
2492
2493s32 bpf_call_args_imm(s16 idx)
2494{
2495 if (WARN_ON_ONCE(idx < 0 || idx >= ARRAY_SIZE(interpreters_args)))
2496 return 0;
2497 return BPF_CALL_IMM(interpreters_args[idx]);
2498}
2499#endif
2500#endif
2501
2502static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2503 const struct bpf_insn *insn)
2504{
2505 /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2506 * is not working properly, so warn about it!
2507 */
2508 WARN_ON_ONCE(1);
2509 return 0;
2510}
2511
2512static bool __bpf_prog_map_compatible(struct bpf_map *map,
2513 const struct bpf_prog *fp)
2514{
2515 enum bpf_prog_type prog_type = resolve_prog_type(fp);
2516 struct bpf_prog_aux *aux = fp->aux;
2517 enum bpf_cgroup_storage_type i;
2518 bool ret = false;
2519 u64 cookie;
2520
2521 if (fp->kprobe_override)
2522 return ret;
2523
2524 spin_lock(&map->owner_lock);
2525 /* There's no owner yet where we could check for compatibility. */
2526 if (!map->owner) {
2527 map->owner = bpf_map_owner_alloc(map);
2528 if (!map->owner)
2529 goto err;
2530 map->owner->type = prog_type;
2531 map->owner->jited = fp->jited;
2532 map->owner->xdp_has_frags = aux->xdp_has_frags;
2533 map->owner->sleepable = fp->sleepable;
2534 map->owner->expected_attach_type = fp->expected_attach_type;
2535 map->owner->attach_func_proto = aux->attach_func_proto;
2536 for_each_cgroup_storage_type(i) {
2537 map->owner->storage_cookie[i] =
2538 aux->cgroup_storage[i] ?
2539 aux->cgroup_storage[i]->cookie : 0;
2540 }
2541 ret = true;
2542 } else {
2543 ret = map->owner->type == prog_type &&
2544 map->owner->jited == fp->jited &&
2545 map->owner->xdp_has_frags == aux->xdp_has_frags &&
2546 map->owner->sleepable == fp->sleepable;
2547 if (ret &&
2548 map->map_type == BPF_MAP_TYPE_PROG_ARRAY &&
2549 map->owner->expected_attach_type != fp->expected_attach_type)
2550 ret = false;
2551 for_each_cgroup_storage_type(i) {
2552 if (!ret)
2553 break;
2554 cookie = aux->cgroup_storage[i] ?
2555 aux->cgroup_storage[i]->cookie : 0;
2556 ret = map->owner->storage_cookie[i] == cookie ||
2557 (!cookie && !aux->tail_call_reachable);
2558 }
2559 if (ret &&
2560 map->owner->attach_func_proto != aux->attach_func_proto) {
2561 switch (prog_type) {
2562 case BPF_PROG_TYPE_TRACING:
2563 case BPF_PROG_TYPE_LSM:
2564 case BPF_PROG_TYPE_EXT:
2565 case BPF_PROG_TYPE_STRUCT_OPS:
2566 ret = false;
2567 break;
2568 default:
2569 break;
2570 }
2571 }
2572 }
2573err:
2574 spin_unlock(&map->owner_lock);
2575 return ret;
2576}
2577
2578bool bpf_prog_map_compatible(struct bpf_map *map, const struct bpf_prog *fp)
2579{
2580 /* XDP programs inserted into maps are not guaranteed to run on
2581 * a particular netdev (and can run outside driver context entirely
2582 * in the case of devmap and cpumap). Until device checks
2583 * are implemented, prohibit adding dev-bound programs to program maps.
2584 */
2585 if (bpf_prog_is_dev_bound(fp->aux))
2586 return false;
2587
2588 return __bpf_prog_map_compatible(map, fp);
2589}
2590
2591static int bpf_check_tail_call(const struct bpf_prog *fp)
2592{
2593 struct bpf_prog_aux *aux = fp->aux;
2594 int i, ret = 0;
2595
2596 mutex_lock(&aux->used_maps_mutex);
2597 for (i = 0; i < aux->used_map_cnt; i++) {
2598 struct bpf_map *map = aux->used_maps[i];
2599
2600 if (!map_type_contains_progs(map))
2601 continue;
2602
2603 if (!__bpf_prog_map_compatible(map, fp)) {
2604 ret = -EINVAL;
2605 goto out;
2606 }
2607 }
2608
2609out:
2610 mutex_unlock(&aux->used_maps_mutex);
2611 return ret;
2612}
2613
2614static bool bpf_prog_select_interpreter(struct bpf_prog *fp)
2615{
2616 bool select_interpreter = false;
2617#ifndef CONFIG_BPF_JIT_ALWAYS_ON
2618 u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2619 u32 idx = (round_up(stack_depth, 32) / 32) - 1;
2620
2621 /* may_goto may cause stack size > 512, leading to idx out-of-bounds.
2622 * But for non-JITed programs, we don't need bpf_func, so no bounds
2623 * check needed.
2624 */
2625 if (idx < ARRAY_SIZE(interpreters)) {
2626 fp->bpf_func = interpreters[idx];
2627 select_interpreter = true;
2628 } else {
2629 fp->bpf_func = __bpf_prog_ret0_warn;
2630 }
2631#else
2632 fp->bpf_func = __bpf_prog_ret0_warn;
2633#endif
2634 return select_interpreter;
2635}
2636
2637static struct bpf_prog *bpf_prog_jit_compile(struct bpf_verifier_env *env, struct bpf_prog *prog)
2638{
2639#ifdef CONFIG_BPF_JIT
2640 struct bpf_prog *orig_prog;
2641
2642 if (!bpf_prog_need_blind(prog))
2643 return bpf_int_jit_compile(env, prog);
2644
2645 orig_prog = prog;
2646 prog = bpf_jit_blind_constants(env, prog);
2647 /*
2648 * Fall back to the interpreter after blinding failures, except when
2649 * the loader was killed.
2650 */
2651 if (IS_ERR(prog)) {
2652 if (PTR_ERR(prog) == -EINTR)
2653 return prog;
2654 goto out_restore;
2655 }
2656
2657 prog = bpf_int_jit_compile(env, prog);
2658 if (prog->jited) {
2659 bpf_jit_prog_release_other(prog, orig_prog);
2660 return prog;
2661 }
2662
2663 bpf_jit_prog_release_other(orig_prog, prog);
2664
2665out_restore:
2666 prog = orig_prog;
2667#endif
2668 return prog;
2669}
2670
2671struct bpf_prog *__bpf_prog_select_runtime(struct bpf_verifier_env *env, struct bpf_prog *fp,
2672 int *err)
2673{
2674 struct bpf_prog *jit_prog;
2675
2676 /* In case of BPF to BPF calls, verifier did all the prep
2677 * work with regards to JITing, etc.
2678 */
2679 bool jit_needed = fp->jit_required;
2680
2681 if (fp->bpf_func)
2682 goto finalize;
2683
2684 if (!bpf_prog_select_interpreter(fp))
2685 jit_needed = true;
2686
2687 /* eBPF JITs can rewrite the program in case constant
2688 * blinding is active. However, in case of error during
2689 * blinding, bpf_int_jit_compile() must always return a
2690 * valid program, which in this case would simply not
2691 * be JITed, but falls back to the interpreter.
2692 */
2693 if (!bpf_prog_is_offloaded(fp->aux)) {
2694 *err = bpf_prog_alloc_jited_linfo(fp);
2695 if (*err)
2696 return fp;
2697
2698 jit_prog = bpf_prog_jit_compile(env, fp);
2699 if (IS_ERR(jit_prog)) {
2700 *err = PTR_ERR(jit_prog);
2701 return fp;
2702 }
2703 fp = jit_prog;
2704 bpf_prog_jit_attempt_done(fp);
2705 if (!fp->jited && jit_needed) {
2706 *err = -ENOTSUPP;
2707 return fp;
2708 }
2709 } else {
2710 *err = bpf_prog_offload_compile(fp);
2711 if (*err)
2712 return fp;
2713 }
2714
2715finalize:
2716 *err = bpf_prog_lock_ro(fp);
2717 if (*err)
2718 return fp;
2719
2720 /* The tail call compatibility check can only be done at
2721 * this late stage as we need to determine, if we deal
2722 * with JITed or non JITed program concatenations and not
2723 * all eBPF JITs might immediately support all features.
2724 */
2725 *err = bpf_check_tail_call(fp);
2726
2727 return fp;
2728}
2729
2730/**
2731 * bpf_prog_select_runtime - select exec runtime for BPF program
2732 * @fp: bpf_prog populated with BPF program
2733 * @err: pointer to error variable
2734 *
2735 * Try to JIT eBPF program, if JIT is not available, use interpreter.
2736 * The BPF program will be executed via bpf_prog_run() function.
2737 *
2738 * Return: the &fp argument along with &err set to 0 for success or
2739 * a negative errno code on failure
2740 */
2741struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2742{
2743 return __bpf_prog_select_runtime(NULL, fp, err);
2744}
2745EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2746
2747static unsigned int __bpf_prog_ret1(const void *ctx,
2748 const struct bpf_insn *insn)
2749{
2750 return 1;
2751}
2752
2753static struct bpf_prog_dummy {
2754 struct bpf_prog prog;
2755} dummy_bpf_prog = {
2756 .prog = {
2757 .bpf_func = __bpf_prog_ret1,
2758 },
2759};
2760
2761struct bpf_prog_array bpf_empty_prog_array = {
2762 .items = {
2763 { .prog = NULL },
2764 },
2765};
2766EXPORT_SYMBOL(bpf_empty_prog_array);
2767
2768struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2769{
2770 struct bpf_prog_array *p;
2771
2772 if (prog_cnt)
2773 p = kzalloc_flex(*p, items, prog_cnt + 1, flags);
2774 else
2775 p = &bpf_empty_prog_array;
2776
2777 return p;
2778}
2779
2780void bpf_prog_array_free(struct bpf_prog_array *progs)
2781{
2782 if (!progs || progs == &bpf_empty_prog_array)
2783 return;
2784 kfree_rcu(progs, rcu);
2785}
2786
2787static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2788{
2789 struct bpf_prog_array *progs;
2790
2791 /*
2792 * RCU Tasks Trace grace period implies RCU grace period, there is no
2793 * need to call kfree_rcu(), just call kfree() directly.
2794 */
2795 progs = container_of(rcu, struct bpf_prog_array, rcu);
2796 kfree(progs);
2797}
2798
2799void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2800{
2801 if (!progs || progs == &bpf_empty_prog_array)
2802 return;
2803 call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2804}
2805
2806int bpf_prog_array_length(struct bpf_prog_array *array)
2807{
2808 struct bpf_prog_array_item *item;
2809 u32 cnt = 0;
2810
2811 for (item = array->items; item->prog; item++)
2812 if (item->prog != &dummy_bpf_prog.prog)
2813 cnt++;
2814 return cnt;
2815}
2816
2817bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2818{
2819 struct bpf_prog_array_item *item;
2820
2821 for (item = array->items; item->prog; item++)
2822 if (item->prog != &dummy_bpf_prog.prog)
2823 return false;
2824 return true;
2825}
2826
2827static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2828 u32 *prog_ids,
2829 u32 request_cnt)
2830{
2831 struct bpf_prog_array_item *item;
2832 int i = 0;
2833
2834 for (item = array->items; item->prog; item++) {
2835 if (item->prog == &dummy_bpf_prog.prog)
2836 continue;
2837 prog_ids[i] = item->prog->aux->id;
2838 if (++i == request_cnt) {
2839 item++;
2840 break;
2841 }
2842 }
2843
2844 return !!(item->prog);
2845}
2846
2847int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2848 __u32 __user *prog_ids, u32 cnt)
2849{
2850 unsigned long err = 0;
2851 bool nospc;
2852 u32 *ids;
2853
2854 /* users of this function are doing:
2855 * cnt = bpf_prog_array_length();
2856 * if (cnt > 0)
2857 * bpf_prog_array_copy_to_user(..., cnt);
2858 * so below kcalloc doesn't need extra cnt > 0 check.
2859 */
2860 ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2861 if (!ids)
2862 return -ENOMEM;
2863 nospc = bpf_prog_array_copy_core(array, ids, cnt);
2864 err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2865 kfree(ids);
2866 if (err)
2867 return -EFAULT;
2868 if (nospc)
2869 return -ENOSPC;
2870 return 0;
2871}
2872
2873void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2874 struct bpf_prog *old_prog)
2875{
2876 struct bpf_prog_array_item *item;
2877
2878 for (item = array->items; item->prog; item++)
2879 if (item->prog == old_prog) {
2880 WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2881 break;
2882 }
2883}
2884
2885/**
2886 * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2887 * index into the program array with
2888 * a dummy no-op program.
2889 * @array: a bpf_prog_array
2890 * @index: the index of the program to replace
2891 *
2892 * Skips over dummy programs, by not counting them, when calculating
2893 * the position of the program to replace.
2894 *
2895 * Return:
2896 * * 0 - Success
2897 * * -EINVAL - Invalid index value. Must be a non-negative integer.
2898 * * -ENOENT - Index out of range
2899 */
2900int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2901{
2902 return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2903}
2904
2905/**
2906 * bpf_prog_array_update_at() - Updates the program at the given index
2907 * into the program array.
2908 * @array: a bpf_prog_array
2909 * @index: the index of the program to update
2910 * @prog: the program to insert into the array
2911 *
2912 * Skips over dummy programs, by not counting them, when calculating
2913 * the position of the program to update.
2914 *
2915 * Return:
2916 * * 0 - Success
2917 * * -EINVAL - Invalid index value. Must be a non-negative integer.
2918 * * -ENOENT - Index out of range
2919 */
2920int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2921 struct bpf_prog *prog)
2922{
2923 struct bpf_prog_array_item *item;
2924
2925 if (unlikely(index < 0))
2926 return -EINVAL;
2927
2928 for (item = array->items; item->prog; item++) {
2929 if (item->prog == &dummy_bpf_prog.prog)
2930 continue;
2931 if (!index) {
2932 WRITE_ONCE(item->prog, prog);
2933 return 0;
2934 }
2935 index--;
2936 }
2937 return -ENOENT;
2938}
2939
2940int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2941 struct bpf_prog *exclude_prog,
2942 struct bpf_prog *include_prog,
2943 u64 bpf_cookie,
2944 struct bpf_prog_array **new_array)
2945{
2946 int new_prog_cnt, carry_prog_cnt = 0;
2947 struct bpf_prog_array_item *existing, *new;
2948 struct bpf_prog_array *array;
2949 bool found_exclude = false;
2950
2951 /* Figure out how many existing progs we need to carry over to
2952 * the new array.
2953 */
2954 if (old_array) {
2955 existing = old_array->items;
2956 for (; existing->prog; existing++) {
2957 if (existing->prog == exclude_prog) {
2958 found_exclude = true;
2959 continue;
2960 }
2961 if (existing->prog != &dummy_bpf_prog.prog)
2962 carry_prog_cnt++;
2963 if (existing->prog == include_prog)
2964 return -EEXIST;
2965 }
2966 }
2967
2968 if (exclude_prog && !found_exclude)
2969 return -ENOENT;
2970
2971 /* How many progs (not NULL) will be in the new array? */
2972 new_prog_cnt = carry_prog_cnt;
2973 if (include_prog)
2974 new_prog_cnt += 1;
2975
2976 /* Do we have any prog (not NULL) in the new array? */
2977 if (!new_prog_cnt) {
2978 *new_array = NULL;
2979 return 0;
2980 }
2981
2982 /* +1 as the end of prog_array is marked with NULL */
2983 array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2984 if (!array)
2985 return -ENOMEM;
2986 new = array->items;
2987
2988 /* Fill in the new prog array */
2989 if (carry_prog_cnt) {
2990 existing = old_array->items;
2991 for (; existing->prog; existing++) {
2992 if (existing->prog == exclude_prog ||
2993 existing->prog == &dummy_bpf_prog.prog)
2994 continue;
2995
2996 new->prog = existing->prog;
2997 new->bpf_cookie = existing->bpf_cookie;
2998 new++;
2999 }
3000 }
3001 if (include_prog) {
3002 new->prog = include_prog;
3003 new->bpf_cookie = bpf_cookie;
3004 new++;
3005 }
3006 new->prog = NULL;
3007 *new_array = array;
3008 return 0;
3009}
3010
3011int bpf_prog_array_copy_info(struct bpf_prog_array *array,
3012 u32 *prog_ids, u32 request_cnt,
3013 u32 *prog_cnt)
3014{
3015 u32 cnt = 0;
3016
3017 if (array)
3018 cnt = bpf_prog_array_length(array);
3019
3020 *prog_cnt = cnt;
3021
3022 /* return early if user requested only program count or nothing to copy */
3023 if (!request_cnt || !cnt)
3024 return 0;
3025
3026 /* this function is called under trace/bpf_trace.c: bpf_event_mutex */
3027 return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
3028 : 0;
3029}
3030
3031void __bpf_free_used_maps(struct bpf_prog_aux *aux,
3032 struct bpf_map **used_maps, u32 len)
3033{
3034 struct bpf_map *map;
3035 bool sleepable;
3036 u32 i;
3037
3038 sleepable = aux->prog->sleepable;
3039 for (i = 0; i < len; i++) {
3040 map = used_maps[i];
3041 if (map->ops->map_poke_untrack)
3042 map->ops->map_poke_untrack(map, aux);
3043 if (sleepable)
3044 atomic64_dec(&map->sleepable_refcnt);
3045 bpf_map_put(map);
3046 }
3047}
3048
3049static void bpf_free_used_maps(struct bpf_prog_aux *aux)
3050{
3051 __bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
3052 kfree(aux->used_maps);
3053}
3054
3055void __bpf_free_used_btfs(struct btf_mod_pair *used_btfs, u32 len)
3056{
3057#ifdef CONFIG_BPF_SYSCALL
3058 struct btf_mod_pair *btf_mod;
3059 u32 i;
3060
3061 for (i = 0; i < len; i++) {
3062 btf_mod = &used_btfs[i];
3063 if (btf_mod->module)
3064 module_put(btf_mod->module);
3065 btf_put(btf_mod->btf);
3066 }
3067#endif
3068}
3069
3070static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
3071{
3072 __bpf_free_used_btfs(aux->used_btfs, aux->used_btf_cnt);
3073 kfree(aux->used_btfs);
3074}
3075
3076static void bpf_prog_free_deferred(struct work_struct *work)
3077{
3078 struct bpf_prog_aux *aux;
3079 int i;
3080
3081 aux = container_of(work, struct bpf_prog_aux, work);
3082#ifdef CONFIG_BPF_SYSCALL
3083 bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
3084 bpf_prog_stream_free(aux->prog);
3085#endif
3086#ifdef CONFIG_CGROUP_BPF
3087 if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
3088 bpf_cgroup_atype_put(aux->cgroup_atype);
3089#endif
3090 bpf_free_used_maps(aux);
3091 bpf_free_used_btfs(aux);
3092 bpf_prog_disassoc_struct_ops(aux->prog);
3093 if (bpf_prog_is_dev_bound(aux))
3094 bpf_prog_dev_bound_destroy(aux->prog);
3095#ifdef CONFIG_PERF_EVENTS
3096 if (aux->prog->has_callchain_buf)
3097 put_callchain_buffers();
3098#endif
3099 if (aux->dst_trampoline)
3100 bpf_trampoline_put(aux->dst_trampoline);
3101 for (i = 0; i < aux->real_func_cnt; i++) {
3102 /* We can just unlink the subprog poke descriptor table as
3103 * it was originally linked to the main program and is also
3104 * released along with it.
3105 */
3106 aux->func[i]->aux->poke_tab = NULL;
3107 bpf_jit_free(aux->func[i]);
3108 }
3109 if (aux->real_func_cnt) {
3110 kfree(aux->func);
3111 bpf_prog_unlock_free(aux->prog);
3112 } else {
3113 bpf_jit_free(aux->prog);
3114 }
3115}
3116
3117void bpf_prog_free(struct bpf_prog *fp)
3118{
3119 struct bpf_prog_aux *aux = fp->aux;
3120
3121 if (aux->dst_prog)
3122 bpf_prog_put(aux->dst_prog);
3123 bpf_token_put(aux->token);
3124 INIT_WORK(&aux->work, bpf_prog_free_deferred);
3125 schedule_work(&aux->work);
3126}
3127EXPORT_SYMBOL_GPL(bpf_prog_free);
3128
3129/* RNG for unprivileged user space with separated state from prandom_u32(). */
3130static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
3131
3132void bpf_user_rnd_init_once(void)
3133{
3134 prandom_init_once(&bpf_user_rnd_state);
3135}
3136
3137BPF_CALL_0(bpf_user_rnd_u32)
3138{
3139 /* Should someone ever have the rather unwise idea to use some
3140 * of the registers passed into this function, then note that
3141 * this function is called from native eBPF and classic-to-eBPF
3142 * transformations. Register assignments from both sides are
3143 * different, f.e. classic always sets fn(ctx, A, X) here.
3144 */
3145 struct rnd_state *state;
3146 u32 res;
3147
3148 state = &get_cpu_var(bpf_user_rnd_state);
3149 res = prandom_u32_state(state);
3150 put_cpu_var(bpf_user_rnd_state);
3151
3152 return res;
3153}
3154
3155BPF_CALL_0(bpf_get_raw_cpu_id)
3156{
3157 return raw_smp_processor_id();
3158}
3159
3160/* Weak definitions of helper functions in case we don't have bpf syscall. */
3161const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
3162const struct bpf_func_proto bpf_map_update_elem_proto __weak;
3163const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
3164const struct bpf_func_proto bpf_map_push_elem_proto __weak;
3165const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
3166const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
3167const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
3168const struct bpf_func_proto bpf_spin_lock_proto __weak;
3169const struct bpf_func_proto bpf_spin_unlock_proto __weak;
3170const struct bpf_func_proto bpf_jiffies64_proto __weak;
3171
3172const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
3173const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
3174const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
3175const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
3176const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
3177const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
3178const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
3179
3180const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
3181const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
3182const struct bpf_func_proto bpf_get_current_comm_proto __weak;
3183const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
3184const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
3185const struct bpf_func_proto bpf_get_local_storage_proto __weak;
3186const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
3187const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
3188const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
3189const struct bpf_func_proto bpf_set_retval_proto __weak;
3190const struct bpf_func_proto bpf_get_retval_proto __weak;
3191
3192const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
3193{
3194 return NULL;
3195}
3196
3197const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
3198{
3199 return NULL;
3200}
3201
3202const struct bpf_func_proto * __weak bpf_get_perf_event_read_value_proto(void)
3203{
3204 return NULL;
3205}
3206
3207u64 __weak
3208bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
3209 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
3210{
3211 return -ENOTSUPP;
3212}
3213EXPORT_SYMBOL_GPL(bpf_event_output);
3214
3215/* Always built-in helper functions. */
3216const struct bpf_func_proto bpf_tail_call_proto = {
3217 /* func is unused for tail_call, we set it to pass the
3218 * get_helper_proto check
3219 */
3220 .func = BPF_PTR_POISON,
3221 .gpl_only = false,
3222 .ret_type = RET_VOID,
3223 .arg1_type = ARG_PTR_TO_CTX,
3224 .arg2_type = ARG_CONST_MAP_PTR,
3225 .arg3_type = ARG_ANYTHING,
3226};
3227
3228/* Stub for JITs that only support cBPF. eBPF programs are interpreted.
3229 * It is encouraged to implement bpf_int_jit_compile() instead, so that
3230 * eBPF and implicitly also cBPF can get JITed!
3231 */
3232struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_verifier_env *env, struct bpf_prog *prog)
3233{
3234 return prog;
3235}
3236
3237/* Stub for JITs that support eBPF. All cBPF code gets transformed into
3238 * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
3239 */
3240void __weak bpf_jit_compile(struct bpf_prog *prog)
3241{
3242}
3243
3244bool __weak bpf_helper_changes_pkt_data(enum bpf_func_id func_id)
3245{
3246 return false;
3247}
3248
3249/* Return TRUE if the JIT backend wants verifier to enable sub-register usage
3250 * analysis code and wants explicit zero extension inserted by verifier.
3251 * Otherwise, return FALSE.
3252 *
3253 * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
3254 * you don't override this. JITs that don't want these extra insns can detect
3255 * them using insn_is_zext.
3256 */
3257bool __weak bpf_jit_needs_zext(void)
3258{
3259 return false;
3260}
3261
3262/* By default, enable the verifier's mitigations against Spectre v1 and v4 for
3263 * all archs. The value returned must not change at runtime as there is
3264 * currently no support for reloading programs that were loaded without
3265 * mitigations.
3266 */
3267bool __weak bpf_jit_bypass_spec_v1(void)
3268{
3269 return false;
3270}
3271
3272bool __weak bpf_jit_bypass_spec_v4(void)
3273{
3274 return false;
3275}
3276
3277/* Return true if the JIT inlines the call to the helper corresponding to
3278 * the imm.
3279 *
3280 * The verifier will not patch the insn->imm for the call to the helper if
3281 * this returns true.
3282 */
3283bool __weak bpf_jit_inlines_helper_call(s32 imm)
3284{
3285 return false;
3286}
3287
3288/* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
3289bool __weak bpf_jit_supports_subprog_tailcalls(void)
3290{
3291 return false;
3292}
3293
3294bool __weak bpf_jit_supports_percpu_insn(void)
3295{
3296 return false;
3297}
3298
3299bool __weak bpf_jit_supports_kfunc_call(void)
3300{
3301 return false;
3302}
3303
3304bool __weak bpf_jit_supports_stack_args(void)
3305{
3306 return false;
3307}
3308
3309bool __weak bpf_jit_supports_arena_args(void)
3310{
3311 return false;
3312}
3313
3314bool __weak bpf_jit_supports_far_kfunc_call(void)
3315{
3316 return false;
3317}
3318
3319bool __weak bpf_jit_supports_arena(void)
3320{
3321 return false;
3322}
3323
3324bool __weak bpf_jit_supports_insn(struct bpf_insn *insn, bool in_arena)
3325{
3326 return false;
3327}
3328
3329bool __weak bpf_jit_supports_fsession(void)
3330{
3331 return false;
3332}
3333
3334u64 __weak bpf_arch_uaddress_limit(void)
3335{
3336#if defined(CONFIG_64BIT) && defined(CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE)
3337 return TASK_SIZE;
3338#else
3339 return 0;
3340#endif
3341}
3342
3343/* Return TRUE if the JIT backend satisfies the following two conditions:
3344 * 1) JIT backend supports atomic_xchg() on pointer-sized words.
3345 * 2) Under the specific arch, the implementation of xchg() is the same
3346 * as atomic_xchg() on pointer-sized words.
3347 */
3348bool __weak bpf_jit_supports_ptr_xchg(void)
3349{
3350 return false;
3351}
3352
3353/* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
3354 * skb_copy_bits(), so provide a weak definition of it for NET-less config.
3355 */
3356int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
3357 int len)
3358{
3359 return -EFAULT;
3360}
3361
3362int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t,
3363 enum bpf_text_poke_type new_t, void *old_addr,
3364 void *new_addr)
3365{
3366 return -ENOTSUPP;
3367}
3368
3369void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
3370{
3371 return ERR_PTR(-ENOTSUPP);
3372}
3373
3374int __weak bpf_arch_text_invalidate(void *dst, size_t len)
3375{
3376 return -ENOTSUPP;
3377}
3378
3379bool __weak bpf_jit_supports_exceptions(void)
3380{
3381 return false;
3382}
3383
3384bool __weak bpf_jit_supports_private_stack(void)
3385{
3386 return false;
3387}
3388
3389void __weak arch_bpf_stack_walk(bool (*consume_fn)(void *cookie, u64 ip, u64 sp, u64 bp), void *cookie)
3390{
3391}
3392
3393bool __weak bpf_jit_supports_timed_may_goto(void)
3394{
3395 return false;
3396}
3397
3398u64 __weak arch_bpf_timed_may_goto(void)
3399{
3400 return 0;
3401}
3402
3403static noinline void bpf_prog_report_may_goto_violation(void)
3404{
3405#ifdef CONFIG_BPF_SYSCALL
3406 struct bpf_stream_stage ss;
3407 struct bpf_prog *prog;
3408
3409 prog = bpf_prog_find_from_stack();
3410 if (!prog)
3411 return;
3412 bpf_stream_stage(ss, prog, BPF_STDERR, ({
3413 bpf_stream_printk(ss, "ERROR: Timeout detected for may_goto instruction\n");
3414 bpf_stream_dump_stack(ss);
3415 }));
3416#endif
3417}
3418
3419u64 bpf_check_timed_may_goto(struct bpf_timed_may_goto *p)
3420{
3421 u64 time = ktime_get_mono_fast_ns();
3422
3423 /* Populate the timestamp for this stack frame, and refresh count. */
3424 if (!p->timestamp) {
3425 p->timestamp = time;
3426 return BPF_MAX_TIMED_LOOPS;
3427 }
3428 /* Check if we've exhausted our time slice, and zero count. */
3429 if (unlikely(time - p->timestamp >= (NSEC_PER_SEC / 4))) {
3430 bpf_prog_report_may_goto_violation();
3431 return 0;
3432 }
3433 /* Refresh the count for the stack frame. */
3434 return BPF_MAX_TIMED_LOOPS;
3435}
3436
3437/* for configs without MMU or 32-bit */
3438__weak const struct bpf_map_ops arena_map_ops;
3439__weak u64 bpf_arena_get_user_vm_start(struct bpf_arena *arena)
3440{
3441 return 0;
3442}
3443__weak u64 bpf_arena_get_kern_vm_start(struct bpf_arena *arena)
3444{
3445 return 0;
3446}
3447
3448#ifdef CONFIG_BPF_SYSCALL
3449__weak bool bpf_arena_handle_page_fault(unsigned long addr, bool is_write,
3450 unsigned long fault_ip)
3451{
3452 return false;
3453}
3454
3455static int __init bpf_global_ma_init(void)
3456{
3457 int ret;
3458
3459 ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
3460 bpf_global_ma_set = !ret;
3461 return ret;
3462}
3463late_initcall(bpf_global_ma_init);
3464#endif
3465
3466DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
3467EXPORT_SYMBOL(bpf_stats_enabled_key);
3468
3469/* All definitions of tracepoints related to BPF. */
3470#define CREATE_TRACE_POINTS
3471#include <linux/bpf_trace.h>
3472
3473EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
3474EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);
3475
3476#ifdef CONFIG_BPF_SYSCALL
3477
3478void bpf_get_linfo_source(struct btf *btf, const struct bpf_line_info *linfo,
3479 struct bpf_linfo_source *src)
3480{
3481 src->file = kbasename(btf_name_by_offset(btf, linfo->file_name_off));
3482 src->line = btf_name_by_offset(btf, linfo->line_off);
3483 src->file_name_off = linfo->file_name_off;
3484 src->line_num = BPF_LINE_INFO_LINE_NUM(linfo->line_col);
3485 src->line_col = BPF_LINE_INFO_LINE_COL(linfo->line_col);
3486}
3487
3488const struct bpf_line_info *bpf_find_linfo(const struct bpf_prog *prog, u32 insn_off)
3489{
3490 const struct bpf_line_info *linfo;
3491 u32 nr_linfo;
3492 int l, r, m;
3493
3494 nr_linfo = prog->aux->nr_linfo;
3495 if (!nr_linfo || insn_off >= prog->len)
3496 return NULL;
3497
3498 linfo = prog->aux->linfo;
3499 /* Loop invariant: linfo[l].insn_off <= insns_off.
3500 * linfo[0].insn_off == 0 which always satisfies above condition.
3501 * Binary search is searching for rightmost linfo entry that satisfies
3502 * the above invariant, giving us the desired record that covers given
3503 * instruction offset.
3504 */
3505 l = 0;
3506 r = nr_linfo - 1;
3507 while (l < r) {
3508 /* (r - l + 1) / 2 means we break a tie to the right, so if:
3509 * l=1, r=2, linfo[l].insn_off <= insn_off, linfo[r].insn_off > insn_off,
3510 * then m=2, we see that linfo[m].insn_off > insn_off, and so
3511 * r becomes 1 and we exit the loop with correct l==1.
3512 * If the tie was broken to the left, m=1 would end us up in
3513 * an endless loop where l and m stay at 1 and r stays at 2.
3514 */
3515 m = l + (r - l + 1) / 2;
3516 if (linfo[m].insn_off <= insn_off)
3517 l = m;
3518 else
3519 r = m - 1;
3520 }
3521
3522 return &linfo[l];
3523}
3524
3525int bpf_prog_get_file_line(struct bpf_prog *prog, unsigned long ip, const char **filep,
3526 const char **linep, int *nump)
3527{
3528 struct bpf_linfo_source src;
3529 int idx = -1, insn_start, insn_end, len;
3530 struct bpf_line_info *linfo;
3531 void **jited_linfo;
3532 struct btf *btf;
3533 int nr_linfo;
3534
3535 btf = prog->aux->btf;
3536 linfo = prog->aux->linfo;
3537 jited_linfo = prog->aux->jited_linfo;
3538
3539 if (!btf || !linfo || !jited_linfo)
3540 return -EINVAL;
3541 len = prog->aux->func ? prog->aux->func[prog->aux->func_idx]->len : prog->len;
3542
3543 linfo = &prog->aux->linfo[prog->aux->linfo_idx];
3544 jited_linfo = &prog->aux->jited_linfo[prog->aux->linfo_idx];
3545
3546 insn_start = linfo[0].insn_off;
3547 insn_end = insn_start + len;
3548 nr_linfo = prog->aux->nr_linfo - prog->aux->linfo_idx;
3549
3550 for (int i = 0; i < nr_linfo &&
3551 linfo[i].insn_off >= insn_start && linfo[i].insn_off < insn_end; i++) {
3552 if (jited_linfo[i] >= (void *)ip)
3553 break;
3554 idx = i;
3555 }
3556
3557 if (idx == -1)
3558 return -ENOENT;
3559
3560 bpf_get_linfo_source(btf, &linfo[idx], &src);
3561 while (isspace(*src.line))
3562 src.line++;
3563 if (filep)
3564 *filep = src.file;
3565 if (linep)
3566 *linep = src.line;
3567 if (nump)
3568 *nump = src.line_num;
3569 return 0;
3570}
3571
3572struct walk_stack_ctx {
3573 struct bpf_prog *prog;
3574};
3575
3576static bool find_from_stack_cb(void *cookie, u64 ip, u64 sp, u64 bp)
3577{
3578 struct walk_stack_ctx *ctxp = cookie;
3579 struct bpf_prog *prog;
3580
3581 /*
3582 * The RCU read lock is held to safely traverse the latch tree, but we
3583 * don't need its protection when accessing the prog, since it has an
3584 * active stack frame on the current stack trace, and won't disappear.
3585 */
3586 rcu_read_lock();
3587 prog = bpf_prog_ksym_find(ip);
3588 rcu_read_unlock();
3589 if (!prog)
3590 return true;
3591 /* Make sure we return the main prog if we found a subprog */
3592 ctxp->prog = prog->aux->main_prog_aux->prog;
3593 return false;
3594}
3595
3596struct bpf_prog *bpf_prog_find_from_stack(void)
3597{
3598 struct walk_stack_ctx ctx = {};
3599
3600 arch_bpf_stack_walk(find_from_stack_cb, &ctx);
3601 return ctx.prog;
3602}
3603
3604#endif