xref: /openbmc/linux/kernel/bpf/core.c (revision cd6d421e)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Linux Socket Filter - Kernel level socket filtering
4  *
5  * Based on the design of the Berkeley Packet Filter. The new
6  * internal format has been designed by PLUMgrid:
7  *
8  *	Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
9  *
10  * Authors:
11  *
12  *	Jay Schulist <jschlst@samba.org>
13  *	Alexei Starovoitov <ast@plumgrid.com>
14  *	Daniel Borkmann <dborkman@redhat.com>
15  *
16  * Andi Kleen - Fix a few bad bugs and races.
17  * Kris Katterjohn - Added many additional checks in bpf_check_classic()
18  */
19 
20 #include <uapi/linux/btf.h>
21 #include <linux/filter.h>
22 #include <linux/skbuff.h>
23 #include <linux/vmalloc.h>
24 #include <linux/random.h>
25 #include <linux/moduleloader.h>
26 #include <linux/bpf.h>
27 #include <linux/btf.h>
28 #include <linux/objtool.h>
29 #include <linux/rbtree_latch.h>
30 #include <linux/kallsyms.h>
31 #include <linux/rcupdate.h>
32 #include <linux/perf_event.h>
33 #include <linux/extable.h>
34 #include <linux/log2.h>
35 #include <asm/unaligned.h>
36 
37 /* Registers */
38 #define BPF_R0	regs[BPF_REG_0]
39 #define BPF_R1	regs[BPF_REG_1]
40 #define BPF_R2	regs[BPF_REG_2]
41 #define BPF_R3	regs[BPF_REG_3]
42 #define BPF_R4	regs[BPF_REG_4]
43 #define BPF_R5	regs[BPF_REG_5]
44 #define BPF_R6	regs[BPF_REG_6]
45 #define BPF_R7	regs[BPF_REG_7]
46 #define BPF_R8	regs[BPF_REG_8]
47 #define BPF_R9	regs[BPF_REG_9]
48 #define BPF_R10	regs[BPF_REG_10]
49 
50 /* Named registers */
51 #define DST	regs[insn->dst_reg]
52 #define SRC	regs[insn->src_reg]
53 #define FP	regs[BPF_REG_FP]
54 #define AX	regs[BPF_REG_AX]
55 #define ARG1	regs[BPF_REG_ARG1]
56 #define CTX	regs[BPF_REG_CTX]
57 #define IMM	insn->imm
58 
59 /* No hurry in this branch
60  *
61  * Exported for the bpf jit load helper.
62  */
63 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
64 {
65 	u8 *ptr = NULL;
66 
67 	if (k >= SKF_NET_OFF)
68 		ptr = skb_network_header(skb) + k - SKF_NET_OFF;
69 	else if (k >= SKF_LL_OFF)
70 		ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
71 
72 	if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
73 		return ptr;
74 
75 	return NULL;
76 }
77 
78 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
79 {
80 	gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
81 	struct bpf_prog_aux *aux;
82 	struct bpf_prog *fp;
83 
84 	size = round_up(size, PAGE_SIZE);
85 	fp = __vmalloc(size, gfp_flags);
86 	if (fp == NULL)
87 		return NULL;
88 
89 	aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT | gfp_extra_flags);
90 	if (aux == NULL) {
91 		vfree(fp);
92 		return NULL;
93 	}
94 	fp->active = alloc_percpu_gfp(int, GFP_KERNEL_ACCOUNT | gfp_extra_flags);
95 	if (!fp->active) {
96 		vfree(fp);
97 		kfree(aux);
98 		return NULL;
99 	}
100 
101 	fp->pages = size / PAGE_SIZE;
102 	fp->aux = aux;
103 	fp->aux->prog = fp;
104 	fp->jit_requested = ebpf_jit_enabled();
105 
106 	INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
107 	mutex_init(&fp->aux->used_maps_mutex);
108 	mutex_init(&fp->aux->dst_mutex);
109 
110 	return fp;
111 }
112 
113 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
114 {
115 	gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
116 	struct bpf_prog *prog;
117 	int cpu;
118 
119 	prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
120 	if (!prog)
121 		return NULL;
122 
123 	prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
124 	if (!prog->stats) {
125 		free_percpu(prog->active);
126 		kfree(prog->aux);
127 		vfree(prog);
128 		return NULL;
129 	}
130 
131 	for_each_possible_cpu(cpu) {
132 		struct bpf_prog_stats *pstats;
133 
134 		pstats = per_cpu_ptr(prog->stats, cpu);
135 		u64_stats_init(&pstats->syncp);
136 	}
137 	return prog;
138 }
139 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
140 
141 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
142 {
143 	if (!prog->aux->nr_linfo || !prog->jit_requested)
144 		return 0;
145 
146 	prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo,
147 					 sizeof(*prog->aux->jited_linfo),
148 					 GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
149 	if (!prog->aux->jited_linfo)
150 		return -ENOMEM;
151 
152 	return 0;
153 }
154 
155 void bpf_prog_free_jited_linfo(struct bpf_prog *prog)
156 {
157 	kfree(prog->aux->jited_linfo);
158 	prog->aux->jited_linfo = NULL;
159 }
160 
161 void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog)
162 {
163 	if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0])
164 		bpf_prog_free_jited_linfo(prog);
165 }
166 
167 /* The jit engine is responsible to provide an array
168  * for insn_off to the jited_off mapping (insn_to_jit_off).
169  *
170  * The idx to this array is the insn_off.  Hence, the insn_off
171  * here is relative to the prog itself instead of the main prog.
172  * This array has one entry for each xlated bpf insn.
173  *
174  * jited_off is the byte off to the last byte of the jited insn.
175  *
176  * Hence, with
177  * insn_start:
178  *      The first bpf insn off of the prog.  The insn off
179  *      here is relative to the main prog.
180  *      e.g. if prog is a subprog, insn_start > 0
181  * linfo_idx:
182  *      The prog's idx to prog->aux->linfo and jited_linfo
183  *
184  * jited_linfo[linfo_idx] = prog->bpf_func
185  *
186  * For i > linfo_idx,
187  *
188  * jited_linfo[i] = prog->bpf_func +
189  *	insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
190  */
191 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
192 			       const u32 *insn_to_jit_off)
193 {
194 	u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
195 	const struct bpf_line_info *linfo;
196 	void **jited_linfo;
197 
198 	if (!prog->aux->jited_linfo)
199 		/* Userspace did not provide linfo */
200 		return;
201 
202 	linfo_idx = prog->aux->linfo_idx;
203 	linfo = &prog->aux->linfo[linfo_idx];
204 	insn_start = linfo[0].insn_off;
205 	insn_end = insn_start + prog->len;
206 
207 	jited_linfo = &prog->aux->jited_linfo[linfo_idx];
208 	jited_linfo[0] = prog->bpf_func;
209 
210 	nr_linfo = prog->aux->nr_linfo - linfo_idx;
211 
212 	for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
213 		/* The verifier ensures that linfo[i].insn_off is
214 		 * strictly increasing
215 		 */
216 		jited_linfo[i] = prog->bpf_func +
217 			insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
218 }
219 
220 void bpf_prog_free_linfo(struct bpf_prog *prog)
221 {
222 	bpf_prog_free_jited_linfo(prog);
223 	kvfree(prog->aux->linfo);
224 }
225 
226 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
227 				  gfp_t gfp_extra_flags)
228 {
229 	gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
230 	struct bpf_prog *fp;
231 	u32 pages;
232 
233 	size = round_up(size, PAGE_SIZE);
234 	pages = size / PAGE_SIZE;
235 	if (pages <= fp_old->pages)
236 		return fp_old;
237 
238 	fp = __vmalloc(size, gfp_flags);
239 	if (fp) {
240 		memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
241 		fp->pages = pages;
242 		fp->aux->prog = fp;
243 
244 		/* We keep fp->aux from fp_old around in the new
245 		 * reallocated structure.
246 		 */
247 		fp_old->aux = NULL;
248 		fp_old->stats = NULL;
249 		fp_old->active = NULL;
250 		__bpf_prog_free(fp_old);
251 	}
252 
253 	return fp;
254 }
255 
256 void __bpf_prog_free(struct bpf_prog *fp)
257 {
258 	if (fp->aux) {
259 		mutex_destroy(&fp->aux->used_maps_mutex);
260 		mutex_destroy(&fp->aux->dst_mutex);
261 		kfree(fp->aux->poke_tab);
262 		kfree(fp->aux);
263 	}
264 	free_percpu(fp->stats);
265 	free_percpu(fp->active);
266 	vfree(fp);
267 }
268 
269 int bpf_prog_calc_tag(struct bpf_prog *fp)
270 {
271 	const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
272 	u32 raw_size = bpf_prog_tag_scratch_size(fp);
273 	u32 digest[SHA1_DIGEST_WORDS];
274 	u32 ws[SHA1_WORKSPACE_WORDS];
275 	u32 i, bsize, psize, blocks;
276 	struct bpf_insn *dst;
277 	bool was_ld_map;
278 	u8 *raw, *todo;
279 	__be32 *result;
280 	__be64 *bits;
281 
282 	raw = vmalloc(raw_size);
283 	if (!raw)
284 		return -ENOMEM;
285 
286 	sha1_init(digest);
287 	memset(ws, 0, sizeof(ws));
288 
289 	/* We need to take out the map fd for the digest calculation
290 	 * since they are unstable from user space side.
291 	 */
292 	dst = (void *)raw;
293 	for (i = 0, was_ld_map = false; i < fp->len; i++) {
294 		dst[i] = fp->insnsi[i];
295 		if (!was_ld_map &&
296 		    dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
297 		    (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
298 		     dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
299 			was_ld_map = true;
300 			dst[i].imm = 0;
301 		} else if (was_ld_map &&
302 			   dst[i].code == 0 &&
303 			   dst[i].dst_reg == 0 &&
304 			   dst[i].src_reg == 0 &&
305 			   dst[i].off == 0) {
306 			was_ld_map = false;
307 			dst[i].imm = 0;
308 		} else {
309 			was_ld_map = false;
310 		}
311 	}
312 
313 	psize = bpf_prog_insn_size(fp);
314 	memset(&raw[psize], 0, raw_size - psize);
315 	raw[psize++] = 0x80;
316 
317 	bsize  = round_up(psize, SHA1_BLOCK_SIZE);
318 	blocks = bsize / SHA1_BLOCK_SIZE;
319 	todo   = raw;
320 	if (bsize - psize >= sizeof(__be64)) {
321 		bits = (__be64 *)(todo + bsize - sizeof(__be64));
322 	} else {
323 		bits = (__be64 *)(todo + bsize + bits_offset);
324 		blocks++;
325 	}
326 	*bits = cpu_to_be64((psize - 1) << 3);
327 
328 	while (blocks--) {
329 		sha1_transform(digest, todo, ws);
330 		todo += SHA1_BLOCK_SIZE;
331 	}
332 
333 	result = (__force __be32 *)digest;
334 	for (i = 0; i < SHA1_DIGEST_WORDS; i++)
335 		result[i] = cpu_to_be32(digest[i]);
336 	memcpy(fp->tag, result, sizeof(fp->tag));
337 
338 	vfree(raw);
339 	return 0;
340 }
341 
342 static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
343 				s32 end_new, s32 curr, const bool probe_pass)
344 {
345 	const s64 imm_min = S32_MIN, imm_max = S32_MAX;
346 	s32 delta = end_new - end_old;
347 	s64 imm = insn->imm;
348 
349 	if (curr < pos && curr + imm + 1 >= end_old)
350 		imm += delta;
351 	else if (curr >= end_new && curr + imm + 1 < end_new)
352 		imm -= delta;
353 	if (imm < imm_min || imm > imm_max)
354 		return -ERANGE;
355 	if (!probe_pass)
356 		insn->imm = imm;
357 	return 0;
358 }
359 
360 static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
361 				s32 end_new, s32 curr, const bool probe_pass)
362 {
363 	const s32 off_min = S16_MIN, off_max = S16_MAX;
364 	s32 delta = end_new - end_old;
365 	s32 off = insn->off;
366 
367 	if (curr < pos && curr + off + 1 >= end_old)
368 		off += delta;
369 	else if (curr >= end_new && curr + off + 1 < end_new)
370 		off -= delta;
371 	if (off < off_min || off > off_max)
372 		return -ERANGE;
373 	if (!probe_pass)
374 		insn->off = off;
375 	return 0;
376 }
377 
378 static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
379 			    s32 end_new, const bool probe_pass)
380 {
381 	u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
382 	struct bpf_insn *insn = prog->insnsi;
383 	int ret = 0;
384 
385 	for (i = 0; i < insn_cnt; i++, insn++) {
386 		u8 code;
387 
388 		/* In the probing pass we still operate on the original,
389 		 * unpatched image in order to check overflows before we
390 		 * do any other adjustments. Therefore skip the patchlet.
391 		 */
392 		if (probe_pass && i == pos) {
393 			i = end_new;
394 			insn = prog->insnsi + end_old;
395 		}
396 		code = insn->code;
397 		if ((BPF_CLASS(code) != BPF_JMP &&
398 		     BPF_CLASS(code) != BPF_JMP32) ||
399 		    BPF_OP(code) == BPF_EXIT)
400 			continue;
401 		/* Adjust offset of jmps if we cross patch boundaries. */
402 		if (BPF_OP(code) == BPF_CALL) {
403 			if (insn->src_reg != BPF_PSEUDO_CALL)
404 				continue;
405 			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
406 						   end_new, i, probe_pass);
407 		} else {
408 			ret = bpf_adj_delta_to_off(insn, pos, end_old,
409 						   end_new, i, probe_pass);
410 		}
411 		if (ret)
412 			break;
413 	}
414 
415 	return ret;
416 }
417 
418 static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
419 {
420 	struct bpf_line_info *linfo;
421 	u32 i, nr_linfo;
422 
423 	nr_linfo = prog->aux->nr_linfo;
424 	if (!nr_linfo || !delta)
425 		return;
426 
427 	linfo = prog->aux->linfo;
428 
429 	for (i = 0; i < nr_linfo; i++)
430 		if (off < linfo[i].insn_off)
431 			break;
432 
433 	/* Push all off < linfo[i].insn_off by delta */
434 	for (; i < nr_linfo; i++)
435 		linfo[i].insn_off += delta;
436 }
437 
438 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
439 				       const struct bpf_insn *patch, u32 len)
440 {
441 	u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
442 	const u32 cnt_max = S16_MAX;
443 	struct bpf_prog *prog_adj;
444 	int err;
445 
446 	/* Since our patchlet doesn't expand the image, we're done. */
447 	if (insn_delta == 0) {
448 		memcpy(prog->insnsi + off, patch, sizeof(*patch));
449 		return prog;
450 	}
451 
452 	insn_adj_cnt = prog->len + insn_delta;
453 
454 	/* Reject anything that would potentially let the insn->off
455 	 * target overflow when we have excessive program expansions.
456 	 * We need to probe here before we do any reallocation where
457 	 * we afterwards may not fail anymore.
458 	 */
459 	if (insn_adj_cnt > cnt_max &&
460 	    (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
461 		return ERR_PTR(err);
462 
463 	/* Several new instructions need to be inserted. Make room
464 	 * for them. Likely, there's no need for a new allocation as
465 	 * last page could have large enough tailroom.
466 	 */
467 	prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
468 				    GFP_USER);
469 	if (!prog_adj)
470 		return ERR_PTR(-ENOMEM);
471 
472 	prog_adj->len = insn_adj_cnt;
473 
474 	/* Patching happens in 3 steps:
475 	 *
476 	 * 1) Move over tail of insnsi from next instruction onwards,
477 	 *    so we can patch the single target insn with one or more
478 	 *    new ones (patching is always from 1 to n insns, n > 0).
479 	 * 2) Inject new instructions at the target location.
480 	 * 3) Adjust branch offsets if necessary.
481 	 */
482 	insn_rest = insn_adj_cnt - off - len;
483 
484 	memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
485 		sizeof(*patch) * insn_rest);
486 	memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
487 
488 	/* We are guaranteed to not fail at this point, otherwise
489 	 * the ship has sailed to reverse to the original state. An
490 	 * overflow cannot happen at this point.
491 	 */
492 	BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
493 
494 	bpf_adj_linfo(prog_adj, off, insn_delta);
495 
496 	return prog_adj;
497 }
498 
499 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
500 {
501 	/* Branch offsets can't overflow when program is shrinking, no need
502 	 * to call bpf_adj_branches(..., true) here
503 	 */
504 	memmove(prog->insnsi + off, prog->insnsi + off + cnt,
505 		sizeof(struct bpf_insn) * (prog->len - off - cnt));
506 	prog->len -= cnt;
507 
508 	return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
509 }
510 
511 static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
512 {
513 	int i;
514 
515 	for (i = 0; i < fp->aux->func_cnt; i++)
516 		bpf_prog_kallsyms_del(fp->aux->func[i]);
517 }
518 
519 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
520 {
521 	bpf_prog_kallsyms_del_subprogs(fp);
522 	bpf_prog_kallsyms_del(fp);
523 }
524 
525 #ifdef CONFIG_BPF_JIT
526 /* All BPF JIT sysctl knobs here. */
527 int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
528 int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
529 int bpf_jit_harden   __read_mostly;
530 long bpf_jit_limit   __read_mostly;
531 
532 static void
533 bpf_prog_ksym_set_addr(struct bpf_prog *prog)
534 {
535 	const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog);
536 	unsigned long addr = (unsigned long)hdr;
537 
538 	WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
539 
540 	prog->aux->ksym.start = (unsigned long) prog->bpf_func;
541 	prog->aux->ksym.end   = addr + hdr->pages * PAGE_SIZE;
542 }
543 
544 static void
545 bpf_prog_ksym_set_name(struct bpf_prog *prog)
546 {
547 	char *sym = prog->aux->ksym.name;
548 	const char *end = sym + KSYM_NAME_LEN;
549 	const struct btf_type *type;
550 	const char *func_name;
551 
552 	BUILD_BUG_ON(sizeof("bpf_prog_") +
553 		     sizeof(prog->tag) * 2 +
554 		     /* name has been null terminated.
555 		      * We should need +1 for the '_' preceding
556 		      * the name.  However, the null character
557 		      * is double counted between the name and the
558 		      * sizeof("bpf_prog_") above, so we omit
559 		      * the +1 here.
560 		      */
561 		     sizeof(prog->aux->name) > KSYM_NAME_LEN);
562 
563 	sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
564 	sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
565 
566 	/* prog->aux->name will be ignored if full btf name is available */
567 	if (prog->aux->func_info_cnt) {
568 		type = btf_type_by_id(prog->aux->btf,
569 				      prog->aux->func_info[prog->aux->func_idx].type_id);
570 		func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
571 		snprintf(sym, (size_t)(end - sym), "_%s", func_name);
572 		return;
573 	}
574 
575 	if (prog->aux->name[0])
576 		snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
577 	else
578 		*sym = 0;
579 }
580 
581 static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
582 {
583 	return container_of(n, struct bpf_ksym, tnode)->start;
584 }
585 
586 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
587 					  struct latch_tree_node *b)
588 {
589 	return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
590 }
591 
592 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
593 {
594 	unsigned long val = (unsigned long)key;
595 	const struct bpf_ksym *ksym;
596 
597 	ksym = container_of(n, struct bpf_ksym, tnode);
598 
599 	if (val < ksym->start)
600 		return -1;
601 	if (val >= ksym->end)
602 		return  1;
603 
604 	return 0;
605 }
606 
607 static const struct latch_tree_ops bpf_tree_ops = {
608 	.less	= bpf_tree_less,
609 	.comp	= bpf_tree_comp,
610 };
611 
612 static DEFINE_SPINLOCK(bpf_lock);
613 static LIST_HEAD(bpf_kallsyms);
614 static struct latch_tree_root bpf_tree __cacheline_aligned;
615 
616 void bpf_ksym_add(struct bpf_ksym *ksym)
617 {
618 	spin_lock_bh(&bpf_lock);
619 	WARN_ON_ONCE(!list_empty(&ksym->lnode));
620 	list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
621 	latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
622 	spin_unlock_bh(&bpf_lock);
623 }
624 
625 static void __bpf_ksym_del(struct bpf_ksym *ksym)
626 {
627 	if (list_empty(&ksym->lnode))
628 		return;
629 
630 	latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
631 	list_del_rcu(&ksym->lnode);
632 }
633 
634 void bpf_ksym_del(struct bpf_ksym *ksym)
635 {
636 	spin_lock_bh(&bpf_lock);
637 	__bpf_ksym_del(ksym);
638 	spin_unlock_bh(&bpf_lock);
639 }
640 
641 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
642 {
643 	return fp->jited && !bpf_prog_was_classic(fp);
644 }
645 
646 static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp)
647 {
648 	return list_empty(&fp->aux->ksym.lnode) ||
649 	       fp->aux->ksym.lnode.prev == LIST_POISON2;
650 }
651 
652 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
653 {
654 	if (!bpf_prog_kallsyms_candidate(fp) ||
655 	    !bpf_capable())
656 		return;
657 
658 	bpf_prog_ksym_set_addr(fp);
659 	bpf_prog_ksym_set_name(fp);
660 	fp->aux->ksym.prog = true;
661 
662 	bpf_ksym_add(&fp->aux->ksym);
663 }
664 
665 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
666 {
667 	if (!bpf_prog_kallsyms_candidate(fp))
668 		return;
669 
670 	bpf_ksym_del(&fp->aux->ksym);
671 }
672 
673 static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
674 {
675 	struct latch_tree_node *n;
676 
677 	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
678 	return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
679 }
680 
681 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
682 				 unsigned long *off, char *sym)
683 {
684 	struct bpf_ksym *ksym;
685 	char *ret = NULL;
686 
687 	rcu_read_lock();
688 	ksym = bpf_ksym_find(addr);
689 	if (ksym) {
690 		unsigned long symbol_start = ksym->start;
691 		unsigned long symbol_end = ksym->end;
692 
693 		strncpy(sym, ksym->name, KSYM_NAME_LEN);
694 
695 		ret = sym;
696 		if (size)
697 			*size = symbol_end - symbol_start;
698 		if (off)
699 			*off  = addr - symbol_start;
700 	}
701 	rcu_read_unlock();
702 
703 	return ret;
704 }
705 
706 bool is_bpf_text_address(unsigned long addr)
707 {
708 	bool ret;
709 
710 	rcu_read_lock();
711 	ret = bpf_ksym_find(addr) != NULL;
712 	rcu_read_unlock();
713 
714 	return ret;
715 }
716 
717 static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
718 {
719 	struct bpf_ksym *ksym = bpf_ksym_find(addr);
720 
721 	return ksym && ksym->prog ?
722 	       container_of(ksym, struct bpf_prog_aux, ksym)->prog :
723 	       NULL;
724 }
725 
726 const struct exception_table_entry *search_bpf_extables(unsigned long addr)
727 {
728 	const struct exception_table_entry *e = NULL;
729 	struct bpf_prog *prog;
730 
731 	rcu_read_lock();
732 	prog = bpf_prog_ksym_find(addr);
733 	if (!prog)
734 		goto out;
735 	if (!prog->aux->num_exentries)
736 		goto out;
737 
738 	e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
739 out:
740 	rcu_read_unlock();
741 	return e;
742 }
743 
744 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
745 		    char *sym)
746 {
747 	struct bpf_ksym *ksym;
748 	unsigned int it = 0;
749 	int ret = -ERANGE;
750 
751 	if (!bpf_jit_kallsyms_enabled())
752 		return ret;
753 
754 	rcu_read_lock();
755 	list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
756 		if (it++ != symnum)
757 			continue;
758 
759 		strncpy(sym, ksym->name, KSYM_NAME_LEN);
760 
761 		*value = ksym->start;
762 		*type  = BPF_SYM_ELF_TYPE;
763 
764 		ret = 0;
765 		break;
766 	}
767 	rcu_read_unlock();
768 
769 	return ret;
770 }
771 
772 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
773 				struct bpf_jit_poke_descriptor *poke)
774 {
775 	struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
776 	static const u32 poke_tab_max = 1024;
777 	u32 slot = prog->aux->size_poke_tab;
778 	u32 size = slot + 1;
779 
780 	if (size > poke_tab_max)
781 		return -ENOSPC;
782 	if (poke->tailcall_target || poke->tailcall_target_stable ||
783 	    poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
784 		return -EINVAL;
785 
786 	switch (poke->reason) {
787 	case BPF_POKE_REASON_TAIL_CALL:
788 		if (!poke->tail_call.map)
789 			return -EINVAL;
790 		break;
791 	default:
792 		return -EINVAL;
793 	}
794 
795 	tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
796 	if (!tab)
797 		return -ENOMEM;
798 
799 	memcpy(&tab[slot], poke, sizeof(*poke));
800 	prog->aux->size_poke_tab = size;
801 	prog->aux->poke_tab = tab;
802 
803 	return slot;
804 }
805 
806 static atomic_long_t bpf_jit_current;
807 
808 /* Can be overridden by an arch's JIT compiler if it has a custom,
809  * dedicated BPF backend memory area, or if neither of the two
810  * below apply.
811  */
812 u64 __weak bpf_jit_alloc_exec_limit(void)
813 {
814 #if defined(MODULES_VADDR)
815 	return MODULES_END - MODULES_VADDR;
816 #else
817 	return VMALLOC_END - VMALLOC_START;
818 #endif
819 }
820 
821 static int __init bpf_jit_charge_init(void)
822 {
823 	/* Only used as heuristic here to derive limit. */
824 	bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2,
825 					    PAGE_SIZE), LONG_MAX);
826 	return 0;
827 }
828 pure_initcall(bpf_jit_charge_init);
829 
830 int bpf_jit_charge_modmem(u32 pages)
831 {
832 	if (atomic_long_add_return(pages, &bpf_jit_current) >
833 	    (bpf_jit_limit >> PAGE_SHIFT)) {
834 		if (!capable(CAP_SYS_ADMIN)) {
835 			atomic_long_sub(pages, &bpf_jit_current);
836 			return -EPERM;
837 		}
838 	}
839 
840 	return 0;
841 }
842 
843 void bpf_jit_uncharge_modmem(u32 pages)
844 {
845 	atomic_long_sub(pages, &bpf_jit_current);
846 }
847 
848 void *__weak bpf_jit_alloc_exec(unsigned long size)
849 {
850 	return module_alloc(size);
851 }
852 
853 void __weak bpf_jit_free_exec(void *addr)
854 {
855 	module_memfree(addr);
856 }
857 
858 struct bpf_binary_header *
859 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
860 		     unsigned int alignment,
861 		     bpf_jit_fill_hole_t bpf_fill_ill_insns)
862 {
863 	struct bpf_binary_header *hdr;
864 	u32 size, hole, start, pages;
865 
866 	WARN_ON_ONCE(!is_power_of_2(alignment) ||
867 		     alignment > BPF_IMAGE_ALIGNMENT);
868 
869 	/* Most of BPF filters are really small, but if some of them
870 	 * fill a page, allow at least 128 extra bytes to insert a
871 	 * random section of illegal instructions.
872 	 */
873 	size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
874 	pages = size / PAGE_SIZE;
875 
876 	if (bpf_jit_charge_modmem(pages))
877 		return NULL;
878 	hdr = bpf_jit_alloc_exec(size);
879 	if (!hdr) {
880 		bpf_jit_uncharge_modmem(pages);
881 		return NULL;
882 	}
883 
884 	/* Fill space with illegal/arch-dep instructions. */
885 	bpf_fill_ill_insns(hdr, size);
886 
887 	hdr->pages = pages;
888 	hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
889 		     PAGE_SIZE - sizeof(*hdr));
890 	start = (get_random_int() % hole) & ~(alignment - 1);
891 
892 	/* Leave a random number of instructions before BPF code. */
893 	*image_ptr = &hdr->image[start];
894 
895 	return hdr;
896 }
897 
898 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
899 {
900 	u32 pages = hdr->pages;
901 
902 	bpf_jit_free_exec(hdr);
903 	bpf_jit_uncharge_modmem(pages);
904 }
905 
906 /* This symbol is only overridden by archs that have different
907  * requirements than the usual eBPF JITs, f.e. when they only
908  * implement cBPF JIT, do not set images read-only, etc.
909  */
910 void __weak bpf_jit_free(struct bpf_prog *fp)
911 {
912 	if (fp->jited) {
913 		struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
914 
915 		bpf_jit_binary_free(hdr);
916 
917 		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
918 	}
919 
920 	bpf_prog_unlock_free(fp);
921 }
922 
923 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
924 			  const struct bpf_insn *insn, bool extra_pass,
925 			  u64 *func_addr, bool *func_addr_fixed)
926 {
927 	s16 off = insn->off;
928 	s32 imm = insn->imm;
929 	u8 *addr;
930 
931 	*func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
932 	if (!*func_addr_fixed) {
933 		/* Place-holder address till the last pass has collected
934 		 * all addresses for JITed subprograms in which case we
935 		 * can pick them up from prog->aux.
936 		 */
937 		if (!extra_pass)
938 			addr = NULL;
939 		else if (prog->aux->func &&
940 			 off >= 0 && off < prog->aux->func_cnt)
941 			addr = (u8 *)prog->aux->func[off]->bpf_func;
942 		else
943 			return -EINVAL;
944 	} else {
945 		/* Address of a BPF helper call. Since part of the core
946 		 * kernel, it's always at a fixed location. __bpf_call_base
947 		 * and the helper with imm relative to it are both in core
948 		 * kernel.
949 		 */
950 		addr = (u8 *)__bpf_call_base + imm;
951 	}
952 
953 	*func_addr = (unsigned long)addr;
954 	return 0;
955 }
956 
957 static int bpf_jit_blind_insn(const struct bpf_insn *from,
958 			      const struct bpf_insn *aux,
959 			      struct bpf_insn *to_buff,
960 			      bool emit_zext)
961 {
962 	struct bpf_insn *to = to_buff;
963 	u32 imm_rnd = get_random_int();
964 	s16 off;
965 
966 	BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
967 	BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
968 
969 	/* Constraints on AX register:
970 	 *
971 	 * AX register is inaccessible from user space. It is mapped in
972 	 * all JITs, and used here for constant blinding rewrites. It is
973 	 * typically "stateless" meaning its contents are only valid within
974 	 * the executed instruction, but not across several instructions.
975 	 * There are a few exceptions however which are further detailed
976 	 * below.
977 	 *
978 	 * Constant blinding is only used by JITs, not in the interpreter.
979 	 * The interpreter uses AX in some occasions as a local temporary
980 	 * register e.g. in DIV or MOD instructions.
981 	 *
982 	 * In restricted circumstances, the verifier can also use the AX
983 	 * register for rewrites as long as they do not interfere with
984 	 * the above cases!
985 	 */
986 	if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
987 		goto out;
988 
989 	if (from->imm == 0 &&
990 	    (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
991 	     from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
992 		*to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
993 		goto out;
994 	}
995 
996 	switch (from->code) {
997 	case BPF_ALU | BPF_ADD | BPF_K:
998 	case BPF_ALU | BPF_SUB | BPF_K:
999 	case BPF_ALU | BPF_AND | BPF_K:
1000 	case BPF_ALU | BPF_OR  | BPF_K:
1001 	case BPF_ALU | BPF_XOR | BPF_K:
1002 	case BPF_ALU | BPF_MUL | BPF_K:
1003 	case BPF_ALU | BPF_MOV | BPF_K:
1004 	case BPF_ALU | BPF_DIV | BPF_K:
1005 	case BPF_ALU | BPF_MOD | BPF_K:
1006 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1007 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1008 		*to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
1009 		break;
1010 
1011 	case BPF_ALU64 | BPF_ADD | BPF_K:
1012 	case BPF_ALU64 | BPF_SUB | BPF_K:
1013 	case BPF_ALU64 | BPF_AND | BPF_K:
1014 	case BPF_ALU64 | BPF_OR  | BPF_K:
1015 	case BPF_ALU64 | BPF_XOR | BPF_K:
1016 	case BPF_ALU64 | BPF_MUL | BPF_K:
1017 	case BPF_ALU64 | BPF_MOV | BPF_K:
1018 	case BPF_ALU64 | BPF_DIV | BPF_K:
1019 	case BPF_ALU64 | BPF_MOD | BPF_K:
1020 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1021 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1022 		*to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
1023 		break;
1024 
1025 	case BPF_JMP | BPF_JEQ  | BPF_K:
1026 	case BPF_JMP | BPF_JNE  | BPF_K:
1027 	case BPF_JMP | BPF_JGT  | BPF_K:
1028 	case BPF_JMP | BPF_JLT  | BPF_K:
1029 	case BPF_JMP | BPF_JGE  | BPF_K:
1030 	case BPF_JMP | BPF_JLE  | BPF_K:
1031 	case BPF_JMP | BPF_JSGT | BPF_K:
1032 	case BPF_JMP | BPF_JSLT | BPF_K:
1033 	case BPF_JMP | BPF_JSGE | BPF_K:
1034 	case BPF_JMP | BPF_JSLE | BPF_K:
1035 	case BPF_JMP | BPF_JSET | BPF_K:
1036 		/* Accommodate for extra offset in case of a backjump. */
1037 		off = from->off;
1038 		if (off < 0)
1039 			off -= 2;
1040 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1041 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1042 		*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1043 		break;
1044 
1045 	case BPF_JMP32 | BPF_JEQ  | BPF_K:
1046 	case BPF_JMP32 | BPF_JNE  | BPF_K:
1047 	case BPF_JMP32 | BPF_JGT  | BPF_K:
1048 	case BPF_JMP32 | BPF_JLT  | BPF_K:
1049 	case BPF_JMP32 | BPF_JGE  | BPF_K:
1050 	case BPF_JMP32 | BPF_JLE  | BPF_K:
1051 	case BPF_JMP32 | BPF_JSGT | BPF_K:
1052 	case BPF_JMP32 | BPF_JSLT | BPF_K:
1053 	case BPF_JMP32 | BPF_JSGE | BPF_K:
1054 	case BPF_JMP32 | BPF_JSLE | BPF_K:
1055 	case BPF_JMP32 | BPF_JSET | BPF_K:
1056 		/* Accommodate for extra offset in case of a backjump. */
1057 		off = from->off;
1058 		if (off < 0)
1059 			off -= 2;
1060 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1061 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1062 		*to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1063 				      off);
1064 		break;
1065 
1066 	case BPF_LD | BPF_IMM | BPF_DW:
1067 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1068 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1069 		*to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1070 		*to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1071 		break;
1072 	case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1073 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1074 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1075 		if (emit_zext)
1076 			*to++ = BPF_ZEXT_REG(BPF_REG_AX);
1077 		*to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
1078 		break;
1079 
1080 	case BPF_ST | BPF_MEM | BPF_DW:
1081 	case BPF_ST | BPF_MEM | BPF_W:
1082 	case BPF_ST | BPF_MEM | BPF_H:
1083 	case BPF_ST | BPF_MEM | BPF_B:
1084 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1085 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1086 		*to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1087 		break;
1088 	}
1089 out:
1090 	return to - to_buff;
1091 }
1092 
1093 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1094 					      gfp_t gfp_extra_flags)
1095 {
1096 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1097 	struct bpf_prog *fp;
1098 
1099 	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1100 	if (fp != NULL) {
1101 		/* aux->prog still points to the fp_other one, so
1102 		 * when promoting the clone to the real program,
1103 		 * this still needs to be adapted.
1104 		 */
1105 		memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1106 	}
1107 
1108 	return fp;
1109 }
1110 
1111 static void bpf_prog_clone_free(struct bpf_prog *fp)
1112 {
1113 	/* aux was stolen by the other clone, so we cannot free
1114 	 * it from this path! It will be freed eventually by the
1115 	 * other program on release.
1116 	 *
1117 	 * At this point, we don't need a deferred release since
1118 	 * clone is guaranteed to not be locked.
1119 	 */
1120 	fp->aux = NULL;
1121 	fp->stats = NULL;
1122 	fp->active = NULL;
1123 	__bpf_prog_free(fp);
1124 }
1125 
1126 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1127 {
1128 	/* We have to repoint aux->prog to self, as we don't
1129 	 * know whether fp here is the clone or the original.
1130 	 */
1131 	fp->aux->prog = fp;
1132 	bpf_prog_clone_free(fp_other);
1133 }
1134 
1135 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1136 {
1137 	struct bpf_insn insn_buff[16], aux[2];
1138 	struct bpf_prog *clone, *tmp;
1139 	int insn_delta, insn_cnt;
1140 	struct bpf_insn *insn;
1141 	int i, rewritten;
1142 
1143 	if (!bpf_jit_blinding_enabled(prog) || prog->blinded)
1144 		return prog;
1145 
1146 	clone = bpf_prog_clone_create(prog, GFP_USER);
1147 	if (!clone)
1148 		return ERR_PTR(-ENOMEM);
1149 
1150 	insn_cnt = clone->len;
1151 	insn = clone->insnsi;
1152 
1153 	for (i = 0; i < insn_cnt; i++, insn++) {
1154 		/* We temporarily need to hold the original ld64 insn
1155 		 * so that we can still access the first part in the
1156 		 * second blinding run.
1157 		 */
1158 		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1159 		    insn[1].code == 0)
1160 			memcpy(aux, insn, sizeof(aux));
1161 
1162 		rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1163 						clone->aux->verifier_zext);
1164 		if (!rewritten)
1165 			continue;
1166 
1167 		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1168 		if (IS_ERR(tmp)) {
1169 			/* Patching may have repointed aux->prog during
1170 			 * realloc from the original one, so we need to
1171 			 * fix it up here on error.
1172 			 */
1173 			bpf_jit_prog_release_other(prog, clone);
1174 			return tmp;
1175 		}
1176 
1177 		clone = tmp;
1178 		insn_delta = rewritten - 1;
1179 
1180 		/* Walk new program and skip insns we just inserted. */
1181 		insn = clone->insnsi + i + insn_delta;
1182 		insn_cnt += insn_delta;
1183 		i        += insn_delta;
1184 	}
1185 
1186 	clone->blinded = 1;
1187 	return clone;
1188 }
1189 #endif /* CONFIG_BPF_JIT */
1190 
1191 /* Base function for offset calculation. Needs to go into .text section,
1192  * therefore keeping it non-static as well; will also be used by JITs
1193  * anyway later on, so do not let the compiler omit it. This also needs
1194  * to go into kallsyms for correlation from e.g. bpftool, so naming
1195  * must not change.
1196  */
1197 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1198 {
1199 	return 0;
1200 }
1201 EXPORT_SYMBOL_GPL(__bpf_call_base);
1202 
1203 /* All UAPI available opcodes. */
1204 #define BPF_INSN_MAP(INSN_2, INSN_3)		\
1205 	/* 32 bit ALU operations. */		\
1206 	/*   Register based. */			\
1207 	INSN_3(ALU, ADD,  X),			\
1208 	INSN_3(ALU, SUB,  X),			\
1209 	INSN_3(ALU, AND,  X),			\
1210 	INSN_3(ALU, OR,   X),			\
1211 	INSN_3(ALU, LSH,  X),			\
1212 	INSN_3(ALU, RSH,  X),			\
1213 	INSN_3(ALU, XOR,  X),			\
1214 	INSN_3(ALU, MUL,  X),			\
1215 	INSN_3(ALU, MOV,  X),			\
1216 	INSN_3(ALU, ARSH, X),			\
1217 	INSN_3(ALU, DIV,  X),			\
1218 	INSN_3(ALU, MOD,  X),			\
1219 	INSN_2(ALU, NEG),			\
1220 	INSN_3(ALU, END, TO_BE),		\
1221 	INSN_3(ALU, END, TO_LE),		\
1222 	/*   Immediate based. */		\
1223 	INSN_3(ALU, ADD,  K),			\
1224 	INSN_3(ALU, SUB,  K),			\
1225 	INSN_3(ALU, AND,  K),			\
1226 	INSN_3(ALU, OR,   K),			\
1227 	INSN_3(ALU, LSH,  K),			\
1228 	INSN_3(ALU, RSH,  K),			\
1229 	INSN_3(ALU, XOR,  K),			\
1230 	INSN_3(ALU, MUL,  K),			\
1231 	INSN_3(ALU, MOV,  K),			\
1232 	INSN_3(ALU, ARSH, K),			\
1233 	INSN_3(ALU, DIV,  K),			\
1234 	INSN_3(ALU, MOD,  K),			\
1235 	/* 64 bit ALU operations. */		\
1236 	/*   Register based. */			\
1237 	INSN_3(ALU64, ADD,  X),			\
1238 	INSN_3(ALU64, SUB,  X),			\
1239 	INSN_3(ALU64, AND,  X),			\
1240 	INSN_3(ALU64, OR,   X),			\
1241 	INSN_3(ALU64, LSH,  X),			\
1242 	INSN_3(ALU64, RSH,  X),			\
1243 	INSN_3(ALU64, XOR,  X),			\
1244 	INSN_3(ALU64, MUL,  X),			\
1245 	INSN_3(ALU64, MOV,  X),			\
1246 	INSN_3(ALU64, ARSH, X),			\
1247 	INSN_3(ALU64, DIV,  X),			\
1248 	INSN_3(ALU64, MOD,  X),			\
1249 	INSN_2(ALU64, NEG),			\
1250 	/*   Immediate based. */		\
1251 	INSN_3(ALU64, ADD,  K),			\
1252 	INSN_3(ALU64, SUB,  K),			\
1253 	INSN_3(ALU64, AND,  K),			\
1254 	INSN_3(ALU64, OR,   K),			\
1255 	INSN_3(ALU64, LSH,  K),			\
1256 	INSN_3(ALU64, RSH,  K),			\
1257 	INSN_3(ALU64, XOR,  K),			\
1258 	INSN_3(ALU64, MUL,  K),			\
1259 	INSN_3(ALU64, MOV,  K),			\
1260 	INSN_3(ALU64, ARSH, K),			\
1261 	INSN_3(ALU64, DIV,  K),			\
1262 	INSN_3(ALU64, MOD,  K),			\
1263 	/* Call instruction. */			\
1264 	INSN_2(JMP, CALL),			\
1265 	/* Exit instruction. */			\
1266 	INSN_2(JMP, EXIT),			\
1267 	/* 32-bit Jump instructions. */		\
1268 	/*   Register based. */			\
1269 	INSN_3(JMP32, JEQ,  X),			\
1270 	INSN_3(JMP32, JNE,  X),			\
1271 	INSN_3(JMP32, JGT,  X),			\
1272 	INSN_3(JMP32, JLT,  X),			\
1273 	INSN_3(JMP32, JGE,  X),			\
1274 	INSN_3(JMP32, JLE,  X),			\
1275 	INSN_3(JMP32, JSGT, X),			\
1276 	INSN_3(JMP32, JSLT, X),			\
1277 	INSN_3(JMP32, JSGE, X),			\
1278 	INSN_3(JMP32, JSLE, X),			\
1279 	INSN_3(JMP32, JSET, X),			\
1280 	/*   Immediate based. */		\
1281 	INSN_3(JMP32, JEQ,  K),			\
1282 	INSN_3(JMP32, JNE,  K),			\
1283 	INSN_3(JMP32, JGT,  K),			\
1284 	INSN_3(JMP32, JLT,  K),			\
1285 	INSN_3(JMP32, JGE,  K),			\
1286 	INSN_3(JMP32, JLE,  K),			\
1287 	INSN_3(JMP32, JSGT, K),			\
1288 	INSN_3(JMP32, JSLT, K),			\
1289 	INSN_3(JMP32, JSGE, K),			\
1290 	INSN_3(JMP32, JSLE, K),			\
1291 	INSN_3(JMP32, JSET, K),			\
1292 	/* Jump instructions. */		\
1293 	/*   Register based. */			\
1294 	INSN_3(JMP, JEQ,  X),			\
1295 	INSN_3(JMP, JNE,  X),			\
1296 	INSN_3(JMP, JGT,  X),			\
1297 	INSN_3(JMP, JLT,  X),			\
1298 	INSN_3(JMP, JGE,  X),			\
1299 	INSN_3(JMP, JLE,  X),			\
1300 	INSN_3(JMP, JSGT, X),			\
1301 	INSN_3(JMP, JSLT, X),			\
1302 	INSN_3(JMP, JSGE, X),			\
1303 	INSN_3(JMP, JSLE, X),			\
1304 	INSN_3(JMP, JSET, X),			\
1305 	/*   Immediate based. */		\
1306 	INSN_3(JMP, JEQ,  K),			\
1307 	INSN_3(JMP, JNE,  K),			\
1308 	INSN_3(JMP, JGT,  K),			\
1309 	INSN_3(JMP, JLT,  K),			\
1310 	INSN_3(JMP, JGE,  K),			\
1311 	INSN_3(JMP, JLE,  K),			\
1312 	INSN_3(JMP, JSGT, K),			\
1313 	INSN_3(JMP, JSLT, K),			\
1314 	INSN_3(JMP, JSGE, K),			\
1315 	INSN_3(JMP, JSLE, K),			\
1316 	INSN_3(JMP, JSET, K),			\
1317 	INSN_2(JMP, JA),			\
1318 	/* Store instructions. */		\
1319 	/*   Register based. */			\
1320 	INSN_3(STX, MEM,  B),			\
1321 	INSN_3(STX, MEM,  H),			\
1322 	INSN_3(STX, MEM,  W),			\
1323 	INSN_3(STX, MEM,  DW),			\
1324 	INSN_3(STX, ATOMIC, W),			\
1325 	INSN_3(STX, ATOMIC, DW),		\
1326 	/*   Immediate based. */		\
1327 	INSN_3(ST, MEM, B),			\
1328 	INSN_3(ST, MEM, H),			\
1329 	INSN_3(ST, MEM, W),			\
1330 	INSN_3(ST, MEM, DW),			\
1331 	/* Load instructions. */		\
1332 	/*   Register based. */			\
1333 	INSN_3(LDX, MEM, B),			\
1334 	INSN_3(LDX, MEM, H),			\
1335 	INSN_3(LDX, MEM, W),			\
1336 	INSN_3(LDX, MEM, DW),			\
1337 	/*   Immediate based. */		\
1338 	INSN_3(LD, IMM, DW)
1339 
1340 bool bpf_opcode_in_insntable(u8 code)
1341 {
1342 #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
1343 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1344 	static const bool public_insntable[256] = {
1345 		[0 ... 255] = false,
1346 		/* Now overwrite non-defaults ... */
1347 		BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1348 		/* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1349 		[BPF_LD | BPF_ABS | BPF_B] = true,
1350 		[BPF_LD | BPF_ABS | BPF_H] = true,
1351 		[BPF_LD | BPF_ABS | BPF_W] = true,
1352 		[BPF_LD | BPF_IND | BPF_B] = true,
1353 		[BPF_LD | BPF_IND | BPF_H] = true,
1354 		[BPF_LD | BPF_IND | BPF_W] = true,
1355 	};
1356 #undef BPF_INSN_3_TBL
1357 #undef BPF_INSN_2_TBL
1358 	return public_insntable[code];
1359 }
1360 
1361 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1362 u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
1363 {
1364 	memset(dst, 0, size);
1365 	return -EFAULT;
1366 }
1367 
1368 /**
1369  *	__bpf_prog_run - run eBPF program on a given context
1370  *	@regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1371  *	@insn: is the array of eBPF instructions
1372  *	@stack: is the eBPF storage stack
1373  *
1374  * Decode and execute eBPF instructions.
1375  */
1376 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack)
1377 {
1378 #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
1379 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1380 	static const void * const jumptable[256] __annotate_jump_table = {
1381 		[0 ... 255] = &&default_label,
1382 		/* Now overwrite non-defaults ... */
1383 		BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1384 		/* Non-UAPI available opcodes. */
1385 		[BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1386 		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1387 		[BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1388 		[BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1389 		[BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1390 		[BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1391 	};
1392 #undef BPF_INSN_3_LBL
1393 #undef BPF_INSN_2_LBL
1394 	u32 tail_call_cnt = 0;
1395 
1396 #define CONT	 ({ insn++; goto select_insn; })
1397 #define CONT_JMP ({ insn++; goto select_insn; })
1398 
1399 select_insn:
1400 	goto *jumptable[insn->code];
1401 
1402 	/* ALU */
1403 #define ALU(OPCODE, OP)			\
1404 	ALU64_##OPCODE##_X:		\
1405 		DST = DST OP SRC;	\
1406 		CONT;			\
1407 	ALU_##OPCODE##_X:		\
1408 		DST = (u32) DST OP (u32) SRC;	\
1409 		CONT;			\
1410 	ALU64_##OPCODE##_K:		\
1411 		DST = DST OP IMM;		\
1412 		CONT;			\
1413 	ALU_##OPCODE##_K:		\
1414 		DST = (u32) DST OP (u32) IMM;	\
1415 		CONT;
1416 
1417 	ALU(ADD,  +)
1418 	ALU(SUB,  -)
1419 	ALU(AND,  &)
1420 	ALU(OR,   |)
1421 	ALU(LSH, <<)
1422 	ALU(RSH, >>)
1423 	ALU(XOR,  ^)
1424 	ALU(MUL,  *)
1425 #undef ALU
1426 	ALU_NEG:
1427 		DST = (u32) -DST;
1428 		CONT;
1429 	ALU64_NEG:
1430 		DST = -DST;
1431 		CONT;
1432 	ALU_MOV_X:
1433 		DST = (u32) SRC;
1434 		CONT;
1435 	ALU_MOV_K:
1436 		DST = (u32) IMM;
1437 		CONT;
1438 	ALU64_MOV_X:
1439 		DST = SRC;
1440 		CONT;
1441 	ALU64_MOV_K:
1442 		DST = IMM;
1443 		CONT;
1444 	LD_IMM_DW:
1445 		DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1446 		insn++;
1447 		CONT;
1448 	ALU_ARSH_X:
1449 		DST = (u64) (u32) (((s32) DST) >> SRC);
1450 		CONT;
1451 	ALU_ARSH_K:
1452 		DST = (u64) (u32) (((s32) DST) >> IMM);
1453 		CONT;
1454 	ALU64_ARSH_X:
1455 		(*(s64 *) &DST) >>= SRC;
1456 		CONT;
1457 	ALU64_ARSH_K:
1458 		(*(s64 *) &DST) >>= IMM;
1459 		CONT;
1460 	ALU64_MOD_X:
1461 		div64_u64_rem(DST, SRC, &AX);
1462 		DST = AX;
1463 		CONT;
1464 	ALU_MOD_X:
1465 		AX = (u32) DST;
1466 		DST = do_div(AX, (u32) SRC);
1467 		CONT;
1468 	ALU64_MOD_K:
1469 		div64_u64_rem(DST, IMM, &AX);
1470 		DST = AX;
1471 		CONT;
1472 	ALU_MOD_K:
1473 		AX = (u32) DST;
1474 		DST = do_div(AX, (u32) IMM);
1475 		CONT;
1476 	ALU64_DIV_X:
1477 		DST = div64_u64(DST, SRC);
1478 		CONT;
1479 	ALU_DIV_X:
1480 		AX = (u32) DST;
1481 		do_div(AX, (u32) SRC);
1482 		DST = (u32) AX;
1483 		CONT;
1484 	ALU64_DIV_K:
1485 		DST = div64_u64(DST, IMM);
1486 		CONT;
1487 	ALU_DIV_K:
1488 		AX = (u32) DST;
1489 		do_div(AX, (u32) IMM);
1490 		DST = (u32) AX;
1491 		CONT;
1492 	ALU_END_TO_BE:
1493 		switch (IMM) {
1494 		case 16:
1495 			DST = (__force u16) cpu_to_be16(DST);
1496 			break;
1497 		case 32:
1498 			DST = (__force u32) cpu_to_be32(DST);
1499 			break;
1500 		case 64:
1501 			DST = (__force u64) cpu_to_be64(DST);
1502 			break;
1503 		}
1504 		CONT;
1505 	ALU_END_TO_LE:
1506 		switch (IMM) {
1507 		case 16:
1508 			DST = (__force u16) cpu_to_le16(DST);
1509 			break;
1510 		case 32:
1511 			DST = (__force u32) cpu_to_le32(DST);
1512 			break;
1513 		case 64:
1514 			DST = (__force u64) cpu_to_le64(DST);
1515 			break;
1516 		}
1517 		CONT;
1518 
1519 	/* CALL */
1520 	JMP_CALL:
1521 		/* Function call scratches BPF_R1-BPF_R5 registers,
1522 		 * preserves BPF_R6-BPF_R9, and stores return value
1523 		 * into BPF_R0.
1524 		 */
1525 		BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1526 						       BPF_R4, BPF_R5);
1527 		CONT;
1528 
1529 	JMP_CALL_ARGS:
1530 		BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
1531 							    BPF_R3, BPF_R4,
1532 							    BPF_R5,
1533 							    insn + insn->off + 1);
1534 		CONT;
1535 
1536 	JMP_TAIL_CALL: {
1537 		struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1538 		struct bpf_array *array = container_of(map, struct bpf_array, map);
1539 		struct bpf_prog *prog;
1540 		u32 index = BPF_R3;
1541 
1542 		if (unlikely(index >= array->map.max_entries))
1543 			goto out;
1544 		if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT))
1545 			goto out;
1546 
1547 		tail_call_cnt++;
1548 
1549 		prog = READ_ONCE(array->ptrs[index]);
1550 		if (!prog)
1551 			goto out;
1552 
1553 		/* ARG1 at this point is guaranteed to point to CTX from
1554 		 * the verifier side due to the fact that the tail call is
1555 		 * handled like a helper, that is, bpf_tail_call_proto,
1556 		 * where arg1_type is ARG_PTR_TO_CTX.
1557 		 */
1558 		insn = prog->insnsi;
1559 		goto select_insn;
1560 out:
1561 		CONT;
1562 	}
1563 	JMP_JA:
1564 		insn += insn->off;
1565 		CONT;
1566 	JMP_EXIT:
1567 		return BPF_R0;
1568 	/* JMP */
1569 #define COND_JMP(SIGN, OPCODE, CMP_OP)				\
1570 	JMP_##OPCODE##_X:					\
1571 		if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {	\
1572 			insn += insn->off;			\
1573 			CONT_JMP;				\
1574 		}						\
1575 		CONT;						\
1576 	JMP32_##OPCODE##_X:					\
1577 		if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {	\
1578 			insn += insn->off;			\
1579 			CONT_JMP;				\
1580 		}						\
1581 		CONT;						\
1582 	JMP_##OPCODE##_K:					\
1583 		if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {	\
1584 			insn += insn->off;			\
1585 			CONT_JMP;				\
1586 		}						\
1587 		CONT;						\
1588 	JMP32_##OPCODE##_K:					\
1589 		if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {	\
1590 			insn += insn->off;			\
1591 			CONT_JMP;				\
1592 		}						\
1593 		CONT;
1594 	COND_JMP(u, JEQ, ==)
1595 	COND_JMP(u, JNE, !=)
1596 	COND_JMP(u, JGT, >)
1597 	COND_JMP(u, JLT, <)
1598 	COND_JMP(u, JGE, >=)
1599 	COND_JMP(u, JLE, <=)
1600 	COND_JMP(u, JSET, &)
1601 	COND_JMP(s, JSGT, >)
1602 	COND_JMP(s, JSLT, <)
1603 	COND_JMP(s, JSGE, >=)
1604 	COND_JMP(s, JSLE, <=)
1605 #undef COND_JMP
1606 	/* STX and ST and LDX*/
1607 #define LDST(SIZEOP, SIZE)						\
1608 	STX_MEM_##SIZEOP:						\
1609 		*(SIZE *)(unsigned long) (DST + insn->off) = SRC;	\
1610 		CONT;							\
1611 	ST_MEM_##SIZEOP:						\
1612 		*(SIZE *)(unsigned long) (DST + insn->off) = IMM;	\
1613 		CONT;							\
1614 	LDX_MEM_##SIZEOP:						\
1615 		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
1616 		CONT;
1617 
1618 	LDST(B,   u8)
1619 	LDST(H,  u16)
1620 	LDST(W,  u32)
1621 	LDST(DW, u64)
1622 #undef LDST
1623 #define LDX_PROBE(SIZEOP, SIZE)							\
1624 	LDX_PROBE_MEM_##SIZEOP:							\
1625 		bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) (SRC + insn->off));	\
1626 		CONT;
1627 	LDX_PROBE(B,  1)
1628 	LDX_PROBE(H,  2)
1629 	LDX_PROBE(W,  4)
1630 	LDX_PROBE(DW, 8)
1631 #undef LDX_PROBE
1632 
1633 #define ATOMIC_ALU_OP(BOP, KOP)						\
1634 		case BOP:						\
1635 			if (BPF_SIZE(insn->code) == BPF_W)		\
1636 				atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
1637 					     (DST + insn->off));	\
1638 			else						\
1639 				atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
1640 					       (DST + insn->off));	\
1641 			break;						\
1642 		case BOP | BPF_FETCH:					\
1643 			if (BPF_SIZE(insn->code) == BPF_W)		\
1644 				SRC = (u32) atomic_fetch_##KOP(		\
1645 					(u32) SRC,			\
1646 					(atomic_t *)(unsigned long) (DST + insn->off)); \
1647 			else						\
1648 				SRC = (u64) atomic64_fetch_##KOP(	\
1649 					(u64) SRC,			\
1650 					(atomic64_t *)(unsigned long) (DST + insn->off)); \
1651 			break;
1652 
1653 	STX_ATOMIC_DW:
1654 	STX_ATOMIC_W:
1655 		switch (IMM) {
1656 		ATOMIC_ALU_OP(BPF_ADD, add)
1657 		ATOMIC_ALU_OP(BPF_AND, and)
1658 		ATOMIC_ALU_OP(BPF_OR, or)
1659 		ATOMIC_ALU_OP(BPF_XOR, xor)
1660 #undef ATOMIC_ALU_OP
1661 
1662 		case BPF_XCHG:
1663 			if (BPF_SIZE(insn->code) == BPF_W)
1664 				SRC = (u32) atomic_xchg(
1665 					(atomic_t *)(unsigned long) (DST + insn->off),
1666 					(u32) SRC);
1667 			else
1668 				SRC = (u64) atomic64_xchg(
1669 					(atomic64_t *)(unsigned long) (DST + insn->off),
1670 					(u64) SRC);
1671 			break;
1672 		case BPF_CMPXCHG:
1673 			if (BPF_SIZE(insn->code) == BPF_W)
1674 				BPF_R0 = (u32) atomic_cmpxchg(
1675 					(atomic_t *)(unsigned long) (DST + insn->off),
1676 					(u32) BPF_R0, (u32) SRC);
1677 			else
1678 				BPF_R0 = (u64) atomic64_cmpxchg(
1679 					(atomic64_t *)(unsigned long) (DST + insn->off),
1680 					(u64) BPF_R0, (u64) SRC);
1681 			break;
1682 
1683 		default:
1684 			goto default_label;
1685 		}
1686 		CONT;
1687 
1688 	default_label:
1689 		/* If we ever reach this, we have a bug somewhere. Die hard here
1690 		 * instead of just returning 0; we could be somewhere in a subprog,
1691 		 * so execution could continue otherwise which we do /not/ want.
1692 		 *
1693 		 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
1694 		 */
1695 		pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
1696 			insn->code, insn->imm);
1697 		BUG_ON(1);
1698 		return 0;
1699 }
1700 
1701 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
1702 #define DEFINE_BPF_PROG_RUN(stack_size) \
1703 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
1704 { \
1705 	u64 stack[stack_size / sizeof(u64)]; \
1706 	u64 regs[MAX_BPF_EXT_REG]; \
1707 \
1708 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
1709 	ARG1 = (u64) (unsigned long) ctx; \
1710 	return ___bpf_prog_run(regs, insn, stack); \
1711 }
1712 
1713 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
1714 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
1715 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
1716 				      const struct bpf_insn *insn) \
1717 { \
1718 	u64 stack[stack_size / sizeof(u64)]; \
1719 	u64 regs[MAX_BPF_EXT_REG]; \
1720 \
1721 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
1722 	BPF_R1 = r1; \
1723 	BPF_R2 = r2; \
1724 	BPF_R3 = r3; \
1725 	BPF_R4 = r4; \
1726 	BPF_R5 = r5; \
1727 	return ___bpf_prog_run(regs, insn, stack); \
1728 }
1729 
1730 #define EVAL1(FN, X) FN(X)
1731 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
1732 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
1733 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
1734 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
1735 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
1736 
1737 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
1738 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
1739 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
1740 
1741 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
1742 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
1743 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
1744 
1745 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
1746 
1747 static unsigned int (*interpreters[])(const void *ctx,
1748 				      const struct bpf_insn *insn) = {
1749 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
1750 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
1751 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
1752 };
1753 #undef PROG_NAME_LIST
1754 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
1755 static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
1756 				  const struct bpf_insn *insn) = {
1757 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
1758 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
1759 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
1760 };
1761 #undef PROG_NAME_LIST
1762 
1763 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
1764 {
1765 	stack_depth = max_t(u32, stack_depth, 1);
1766 	insn->off = (s16) insn->imm;
1767 	insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
1768 		__bpf_call_base_args;
1769 	insn->code = BPF_JMP | BPF_CALL_ARGS;
1770 }
1771 
1772 #else
1773 static unsigned int __bpf_prog_ret0_warn(const void *ctx,
1774 					 const struct bpf_insn *insn)
1775 {
1776 	/* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
1777 	 * is not working properly, so warn about it!
1778 	 */
1779 	WARN_ON_ONCE(1);
1780 	return 0;
1781 }
1782 #endif
1783 
1784 bool bpf_prog_array_compatible(struct bpf_array *array,
1785 			       const struct bpf_prog *fp)
1786 {
1787 	if (fp->kprobe_override)
1788 		return false;
1789 
1790 	if (!array->aux->type) {
1791 		/* There's no owner yet where we could check for
1792 		 * compatibility.
1793 		 */
1794 		array->aux->type  = fp->type;
1795 		array->aux->jited = fp->jited;
1796 		return true;
1797 	}
1798 
1799 	return array->aux->type  == fp->type &&
1800 	       array->aux->jited == fp->jited;
1801 }
1802 
1803 static int bpf_check_tail_call(const struct bpf_prog *fp)
1804 {
1805 	struct bpf_prog_aux *aux = fp->aux;
1806 	int i, ret = 0;
1807 
1808 	mutex_lock(&aux->used_maps_mutex);
1809 	for (i = 0; i < aux->used_map_cnt; i++) {
1810 		struct bpf_map *map = aux->used_maps[i];
1811 		struct bpf_array *array;
1812 
1813 		if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
1814 			continue;
1815 
1816 		array = container_of(map, struct bpf_array, map);
1817 		if (!bpf_prog_array_compatible(array, fp)) {
1818 			ret = -EINVAL;
1819 			goto out;
1820 		}
1821 	}
1822 
1823 out:
1824 	mutex_unlock(&aux->used_maps_mutex);
1825 	return ret;
1826 }
1827 
1828 static void bpf_prog_select_func(struct bpf_prog *fp)
1829 {
1830 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1831 	u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
1832 
1833 	fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
1834 #else
1835 	fp->bpf_func = __bpf_prog_ret0_warn;
1836 #endif
1837 }
1838 
1839 /**
1840  *	bpf_prog_select_runtime - select exec runtime for BPF program
1841  *	@fp: bpf_prog populated with internal BPF program
1842  *	@err: pointer to error variable
1843  *
1844  * Try to JIT eBPF program, if JIT is not available, use interpreter.
1845  * The BPF program will be executed via BPF_PROG_RUN() macro.
1846  */
1847 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
1848 {
1849 	/* In case of BPF to BPF calls, verifier did all the prep
1850 	 * work with regards to JITing, etc.
1851 	 */
1852 	if (fp->bpf_func)
1853 		goto finalize;
1854 
1855 	bpf_prog_select_func(fp);
1856 
1857 	/* eBPF JITs can rewrite the program in case constant
1858 	 * blinding is active. However, in case of error during
1859 	 * blinding, bpf_int_jit_compile() must always return a
1860 	 * valid program, which in this case would simply not
1861 	 * be JITed, but falls back to the interpreter.
1862 	 */
1863 	if (!bpf_prog_is_dev_bound(fp->aux)) {
1864 		*err = bpf_prog_alloc_jited_linfo(fp);
1865 		if (*err)
1866 			return fp;
1867 
1868 		fp = bpf_int_jit_compile(fp);
1869 		if (!fp->jited) {
1870 			bpf_prog_free_jited_linfo(fp);
1871 #ifdef CONFIG_BPF_JIT_ALWAYS_ON
1872 			*err = -ENOTSUPP;
1873 			return fp;
1874 #endif
1875 		} else {
1876 			bpf_prog_free_unused_jited_linfo(fp);
1877 		}
1878 	} else {
1879 		*err = bpf_prog_offload_compile(fp);
1880 		if (*err)
1881 			return fp;
1882 	}
1883 
1884 finalize:
1885 	bpf_prog_lock_ro(fp);
1886 
1887 	/* The tail call compatibility check can only be done at
1888 	 * this late stage as we need to determine, if we deal
1889 	 * with JITed or non JITed program concatenations and not
1890 	 * all eBPF JITs might immediately support all features.
1891 	 */
1892 	*err = bpf_check_tail_call(fp);
1893 
1894 	return fp;
1895 }
1896 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
1897 
1898 static unsigned int __bpf_prog_ret1(const void *ctx,
1899 				    const struct bpf_insn *insn)
1900 {
1901 	return 1;
1902 }
1903 
1904 static struct bpf_prog_dummy {
1905 	struct bpf_prog prog;
1906 } dummy_bpf_prog = {
1907 	.prog = {
1908 		.bpf_func = __bpf_prog_ret1,
1909 	},
1910 };
1911 
1912 /* to avoid allocating empty bpf_prog_array for cgroups that
1913  * don't have bpf program attached use one global 'empty_prog_array'
1914  * It will not be modified the caller of bpf_prog_array_alloc()
1915  * (since caller requested prog_cnt == 0)
1916  * that pointer should be 'freed' by bpf_prog_array_free()
1917  */
1918 static struct {
1919 	struct bpf_prog_array hdr;
1920 	struct bpf_prog *null_prog;
1921 } empty_prog_array = {
1922 	.null_prog = NULL,
1923 };
1924 
1925 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
1926 {
1927 	if (prog_cnt)
1928 		return kzalloc(sizeof(struct bpf_prog_array) +
1929 			       sizeof(struct bpf_prog_array_item) *
1930 			       (prog_cnt + 1),
1931 			       flags);
1932 
1933 	return &empty_prog_array.hdr;
1934 }
1935 
1936 void bpf_prog_array_free(struct bpf_prog_array *progs)
1937 {
1938 	if (!progs || progs == &empty_prog_array.hdr)
1939 		return;
1940 	kfree_rcu(progs, rcu);
1941 }
1942 
1943 int bpf_prog_array_length(struct bpf_prog_array *array)
1944 {
1945 	struct bpf_prog_array_item *item;
1946 	u32 cnt = 0;
1947 
1948 	for (item = array->items; item->prog; item++)
1949 		if (item->prog != &dummy_bpf_prog.prog)
1950 			cnt++;
1951 	return cnt;
1952 }
1953 
1954 bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
1955 {
1956 	struct bpf_prog_array_item *item;
1957 
1958 	for (item = array->items; item->prog; item++)
1959 		if (item->prog != &dummy_bpf_prog.prog)
1960 			return false;
1961 	return true;
1962 }
1963 
1964 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
1965 				     u32 *prog_ids,
1966 				     u32 request_cnt)
1967 {
1968 	struct bpf_prog_array_item *item;
1969 	int i = 0;
1970 
1971 	for (item = array->items; item->prog; item++) {
1972 		if (item->prog == &dummy_bpf_prog.prog)
1973 			continue;
1974 		prog_ids[i] = item->prog->aux->id;
1975 		if (++i == request_cnt) {
1976 			item++;
1977 			break;
1978 		}
1979 	}
1980 
1981 	return !!(item->prog);
1982 }
1983 
1984 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
1985 				__u32 __user *prog_ids, u32 cnt)
1986 {
1987 	unsigned long err = 0;
1988 	bool nospc;
1989 	u32 *ids;
1990 
1991 	/* users of this function are doing:
1992 	 * cnt = bpf_prog_array_length();
1993 	 * if (cnt > 0)
1994 	 *     bpf_prog_array_copy_to_user(..., cnt);
1995 	 * so below kcalloc doesn't need extra cnt > 0 check.
1996 	 */
1997 	ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
1998 	if (!ids)
1999 		return -ENOMEM;
2000 	nospc = bpf_prog_array_copy_core(array, ids, cnt);
2001 	err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2002 	kfree(ids);
2003 	if (err)
2004 		return -EFAULT;
2005 	if (nospc)
2006 		return -ENOSPC;
2007 	return 0;
2008 }
2009 
2010 void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2011 				struct bpf_prog *old_prog)
2012 {
2013 	struct bpf_prog_array_item *item;
2014 
2015 	for (item = array->items; item->prog; item++)
2016 		if (item->prog == old_prog) {
2017 			WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2018 			break;
2019 		}
2020 }
2021 
2022 /**
2023  * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2024  *                                   index into the program array with
2025  *                                   a dummy no-op program.
2026  * @array: a bpf_prog_array
2027  * @index: the index of the program to replace
2028  *
2029  * Skips over dummy programs, by not counting them, when calculating
2030  * the position of the program to replace.
2031  *
2032  * Return:
2033  * * 0		- Success
2034  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2035  * * -ENOENT	- Index out of range
2036  */
2037 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2038 {
2039 	return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2040 }
2041 
2042 /**
2043  * bpf_prog_array_update_at() - Updates the program at the given index
2044  *                              into the program array.
2045  * @array: a bpf_prog_array
2046  * @index: the index of the program to update
2047  * @prog: the program to insert into the array
2048  *
2049  * Skips over dummy programs, by not counting them, when calculating
2050  * the position of the program to update.
2051  *
2052  * Return:
2053  * * 0		- Success
2054  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2055  * * -ENOENT	- Index out of range
2056  */
2057 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2058 			     struct bpf_prog *prog)
2059 {
2060 	struct bpf_prog_array_item *item;
2061 
2062 	if (unlikely(index < 0))
2063 		return -EINVAL;
2064 
2065 	for (item = array->items; item->prog; item++) {
2066 		if (item->prog == &dummy_bpf_prog.prog)
2067 			continue;
2068 		if (!index) {
2069 			WRITE_ONCE(item->prog, prog);
2070 			return 0;
2071 		}
2072 		index--;
2073 	}
2074 	return -ENOENT;
2075 }
2076 
2077 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2078 			struct bpf_prog *exclude_prog,
2079 			struct bpf_prog *include_prog,
2080 			struct bpf_prog_array **new_array)
2081 {
2082 	int new_prog_cnt, carry_prog_cnt = 0;
2083 	struct bpf_prog_array_item *existing;
2084 	struct bpf_prog_array *array;
2085 	bool found_exclude = false;
2086 	int new_prog_idx = 0;
2087 
2088 	/* Figure out how many existing progs we need to carry over to
2089 	 * the new array.
2090 	 */
2091 	if (old_array) {
2092 		existing = old_array->items;
2093 		for (; existing->prog; existing++) {
2094 			if (existing->prog == exclude_prog) {
2095 				found_exclude = true;
2096 				continue;
2097 			}
2098 			if (existing->prog != &dummy_bpf_prog.prog)
2099 				carry_prog_cnt++;
2100 			if (existing->prog == include_prog)
2101 				return -EEXIST;
2102 		}
2103 	}
2104 
2105 	if (exclude_prog && !found_exclude)
2106 		return -ENOENT;
2107 
2108 	/* How many progs (not NULL) will be in the new array? */
2109 	new_prog_cnt = carry_prog_cnt;
2110 	if (include_prog)
2111 		new_prog_cnt += 1;
2112 
2113 	/* Do we have any prog (not NULL) in the new array? */
2114 	if (!new_prog_cnt) {
2115 		*new_array = NULL;
2116 		return 0;
2117 	}
2118 
2119 	/* +1 as the end of prog_array is marked with NULL */
2120 	array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2121 	if (!array)
2122 		return -ENOMEM;
2123 
2124 	/* Fill in the new prog array */
2125 	if (carry_prog_cnt) {
2126 		existing = old_array->items;
2127 		for (; existing->prog; existing++)
2128 			if (existing->prog != exclude_prog &&
2129 			    existing->prog != &dummy_bpf_prog.prog) {
2130 				array->items[new_prog_idx++].prog =
2131 					existing->prog;
2132 			}
2133 	}
2134 	if (include_prog)
2135 		array->items[new_prog_idx++].prog = include_prog;
2136 	array->items[new_prog_idx].prog = NULL;
2137 	*new_array = array;
2138 	return 0;
2139 }
2140 
2141 int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2142 			     u32 *prog_ids, u32 request_cnt,
2143 			     u32 *prog_cnt)
2144 {
2145 	u32 cnt = 0;
2146 
2147 	if (array)
2148 		cnt = bpf_prog_array_length(array);
2149 
2150 	*prog_cnt = cnt;
2151 
2152 	/* return early if user requested only program count or nothing to copy */
2153 	if (!request_cnt || !cnt)
2154 		return 0;
2155 
2156 	/* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2157 	return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2158 								     : 0;
2159 }
2160 
2161 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2162 			  struct bpf_map **used_maps, u32 len)
2163 {
2164 	struct bpf_map *map;
2165 	u32 i;
2166 
2167 	for (i = 0; i < len; i++) {
2168 		map = used_maps[i];
2169 		if (map->ops->map_poke_untrack)
2170 			map->ops->map_poke_untrack(map, aux);
2171 		bpf_map_put(map);
2172 	}
2173 }
2174 
2175 static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2176 {
2177 	__bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2178 	kfree(aux->used_maps);
2179 }
2180 
2181 void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
2182 			  struct btf_mod_pair *used_btfs, u32 len)
2183 {
2184 #ifdef CONFIG_BPF_SYSCALL
2185 	struct btf_mod_pair *btf_mod;
2186 	u32 i;
2187 
2188 	for (i = 0; i < len; i++) {
2189 		btf_mod = &used_btfs[i];
2190 		if (btf_mod->module)
2191 			module_put(btf_mod->module);
2192 		btf_put(btf_mod->btf);
2193 	}
2194 #endif
2195 }
2196 
2197 static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2198 {
2199 	__bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt);
2200 	kfree(aux->used_btfs);
2201 }
2202 
2203 static void bpf_prog_free_deferred(struct work_struct *work)
2204 {
2205 	struct bpf_prog_aux *aux;
2206 	int i;
2207 
2208 	aux = container_of(work, struct bpf_prog_aux, work);
2209 	bpf_free_used_maps(aux);
2210 	bpf_free_used_btfs(aux);
2211 	if (bpf_prog_is_dev_bound(aux))
2212 		bpf_prog_offload_destroy(aux->prog);
2213 #ifdef CONFIG_PERF_EVENTS
2214 	if (aux->prog->has_callchain_buf)
2215 		put_callchain_buffers();
2216 #endif
2217 	if (aux->dst_trampoline)
2218 		bpf_trampoline_put(aux->dst_trampoline);
2219 	for (i = 0; i < aux->func_cnt; i++)
2220 		bpf_jit_free(aux->func[i]);
2221 	if (aux->func_cnt) {
2222 		kfree(aux->func);
2223 		bpf_prog_unlock_free(aux->prog);
2224 	} else {
2225 		bpf_jit_free(aux->prog);
2226 	}
2227 }
2228 
2229 /* Free internal BPF program */
2230 void bpf_prog_free(struct bpf_prog *fp)
2231 {
2232 	struct bpf_prog_aux *aux = fp->aux;
2233 
2234 	if (aux->dst_prog)
2235 		bpf_prog_put(aux->dst_prog);
2236 	INIT_WORK(&aux->work, bpf_prog_free_deferred);
2237 	schedule_work(&aux->work);
2238 }
2239 EXPORT_SYMBOL_GPL(bpf_prog_free);
2240 
2241 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
2242 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2243 
2244 void bpf_user_rnd_init_once(void)
2245 {
2246 	prandom_init_once(&bpf_user_rnd_state);
2247 }
2248 
2249 BPF_CALL_0(bpf_user_rnd_u32)
2250 {
2251 	/* Should someone ever have the rather unwise idea to use some
2252 	 * of the registers passed into this function, then note that
2253 	 * this function is called from native eBPF and classic-to-eBPF
2254 	 * transformations. Register assignments from both sides are
2255 	 * different, f.e. classic always sets fn(ctx, A, X) here.
2256 	 */
2257 	struct rnd_state *state;
2258 	u32 res;
2259 
2260 	state = &get_cpu_var(bpf_user_rnd_state);
2261 	res = prandom_u32_state(state);
2262 	put_cpu_var(bpf_user_rnd_state);
2263 
2264 	return res;
2265 }
2266 
2267 BPF_CALL_0(bpf_get_raw_cpu_id)
2268 {
2269 	return raw_smp_processor_id();
2270 }
2271 
2272 /* Weak definitions of helper functions in case we don't have bpf syscall. */
2273 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2274 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2275 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2276 const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2277 const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2278 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2279 const struct bpf_func_proto bpf_spin_lock_proto __weak;
2280 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2281 const struct bpf_func_proto bpf_jiffies64_proto __weak;
2282 
2283 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2284 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2285 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2286 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2287 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2288 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2289 
2290 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2291 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2292 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2293 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2294 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2295 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2296 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2297 const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2298 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2299 
2300 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2301 {
2302 	return NULL;
2303 }
2304 
2305 u64 __weak
2306 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2307 		 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2308 {
2309 	return -ENOTSUPP;
2310 }
2311 EXPORT_SYMBOL_GPL(bpf_event_output);
2312 
2313 /* Always built-in helper functions. */
2314 const struct bpf_func_proto bpf_tail_call_proto = {
2315 	.func		= NULL,
2316 	.gpl_only	= false,
2317 	.ret_type	= RET_VOID,
2318 	.arg1_type	= ARG_PTR_TO_CTX,
2319 	.arg2_type	= ARG_CONST_MAP_PTR,
2320 	.arg3_type	= ARG_ANYTHING,
2321 };
2322 
2323 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2324  * It is encouraged to implement bpf_int_jit_compile() instead, so that
2325  * eBPF and implicitly also cBPF can get JITed!
2326  */
2327 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2328 {
2329 	return prog;
2330 }
2331 
2332 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
2333  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2334  */
2335 void __weak bpf_jit_compile(struct bpf_prog *prog)
2336 {
2337 }
2338 
2339 bool __weak bpf_helper_changes_pkt_data(void *func)
2340 {
2341 	return false;
2342 }
2343 
2344 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2345  * analysis code and wants explicit zero extension inserted by verifier.
2346  * Otherwise, return FALSE.
2347  *
2348  * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2349  * you don't override this. JITs that don't want these extra insns can detect
2350  * them using insn_is_zext.
2351  */
2352 bool __weak bpf_jit_needs_zext(void)
2353 {
2354 	return false;
2355 }
2356 
2357 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
2358  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
2359  */
2360 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
2361 			 int len)
2362 {
2363 	return -EFAULT;
2364 }
2365 
2366 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
2367 			      void *addr1, void *addr2)
2368 {
2369 	return -ENOTSUPP;
2370 }
2371 
2372 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
2373 EXPORT_SYMBOL(bpf_stats_enabled_key);
2374 
2375 /* All definitions of tracepoints related to BPF. */
2376 #define CREATE_TRACE_POINTS
2377 #include <linux/bpf_trace.h>
2378 
2379 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
2380 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);
2381