xref: /openbmc/linux/kernel/bpf/core.c (revision 68198dca)
1 /*
2  * Linux Socket Filter - Kernel level socket filtering
3  *
4  * Based on the design of the Berkeley Packet Filter. The new
5  * internal format has been designed by PLUMgrid:
6  *
7  *	Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
8  *
9  * Authors:
10  *
11  *	Jay Schulist <jschlst@samba.org>
12  *	Alexei Starovoitov <ast@plumgrid.com>
13  *	Daniel Borkmann <dborkman@redhat.com>
14  *
15  * This program is free software; you can redistribute it and/or
16  * modify it under the terms of the GNU General Public License
17  * as published by the Free Software Foundation; either version
18  * 2 of the License, or (at your option) any later version.
19  *
20  * Andi Kleen - Fix a few bad bugs and races.
21  * Kris Katterjohn - Added many additional checks in bpf_check_classic()
22  */
23 
24 #include <linux/filter.h>
25 #include <linux/skbuff.h>
26 #include <linux/vmalloc.h>
27 #include <linux/random.h>
28 #include <linux/moduleloader.h>
29 #include <linux/bpf.h>
30 #include <linux/frame.h>
31 #include <linux/rbtree_latch.h>
32 #include <linux/kallsyms.h>
33 #include <linux/rcupdate.h>
34 
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 ARG1	regs[BPF_REG_ARG1]
55 #define CTX	regs[BPF_REG_CTX]
56 #define IMM	insn->imm
57 
58 /* No hurry in this branch
59  *
60  * Exported for the bpf jit load helper.
61  */
62 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
63 {
64 	u8 *ptr = NULL;
65 
66 	if (k >= SKF_NET_OFF)
67 		ptr = skb_network_header(skb) + k - SKF_NET_OFF;
68 	else if (k >= SKF_LL_OFF)
69 		ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
70 
71 	if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
72 		return ptr;
73 
74 	return NULL;
75 }
76 
77 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
78 {
79 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
80 	struct bpf_prog_aux *aux;
81 	struct bpf_prog *fp;
82 
83 	size = round_up(size, PAGE_SIZE);
84 	fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
85 	if (fp == NULL)
86 		return NULL;
87 
88 	aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
89 	if (aux == NULL) {
90 		vfree(fp);
91 		return NULL;
92 	}
93 
94 	fp->pages = size / PAGE_SIZE;
95 	fp->aux = aux;
96 	fp->aux->prog = fp;
97 
98 	INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode);
99 
100 	return fp;
101 }
102 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
103 
104 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
105 				  gfp_t gfp_extra_flags)
106 {
107 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
108 	struct bpf_prog *fp;
109 	u32 pages, delta;
110 	int ret;
111 
112 	BUG_ON(fp_old == NULL);
113 
114 	size = round_up(size, PAGE_SIZE);
115 	pages = size / PAGE_SIZE;
116 	if (pages <= fp_old->pages)
117 		return fp_old;
118 
119 	delta = pages - fp_old->pages;
120 	ret = __bpf_prog_charge(fp_old->aux->user, delta);
121 	if (ret)
122 		return NULL;
123 
124 	fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
125 	if (fp == NULL) {
126 		__bpf_prog_uncharge(fp_old->aux->user, delta);
127 	} else {
128 		memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
129 		fp->pages = pages;
130 		fp->aux->prog = fp;
131 
132 		/* We keep fp->aux from fp_old around in the new
133 		 * reallocated structure.
134 		 */
135 		fp_old->aux = NULL;
136 		__bpf_prog_free(fp_old);
137 	}
138 
139 	return fp;
140 }
141 
142 void __bpf_prog_free(struct bpf_prog *fp)
143 {
144 	kfree(fp->aux);
145 	vfree(fp);
146 }
147 
148 int bpf_prog_calc_tag(struct bpf_prog *fp)
149 {
150 	const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64);
151 	u32 raw_size = bpf_prog_tag_scratch_size(fp);
152 	u32 digest[SHA_DIGEST_WORDS];
153 	u32 ws[SHA_WORKSPACE_WORDS];
154 	u32 i, bsize, psize, blocks;
155 	struct bpf_insn *dst;
156 	bool was_ld_map;
157 	u8 *raw, *todo;
158 	__be32 *result;
159 	__be64 *bits;
160 
161 	raw = vmalloc(raw_size);
162 	if (!raw)
163 		return -ENOMEM;
164 
165 	sha_init(digest);
166 	memset(ws, 0, sizeof(ws));
167 
168 	/* We need to take out the map fd for the digest calculation
169 	 * since they are unstable from user space side.
170 	 */
171 	dst = (void *)raw;
172 	for (i = 0, was_ld_map = false; i < fp->len; i++) {
173 		dst[i] = fp->insnsi[i];
174 		if (!was_ld_map &&
175 		    dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
176 		    dst[i].src_reg == BPF_PSEUDO_MAP_FD) {
177 			was_ld_map = true;
178 			dst[i].imm = 0;
179 		} else if (was_ld_map &&
180 			   dst[i].code == 0 &&
181 			   dst[i].dst_reg == 0 &&
182 			   dst[i].src_reg == 0 &&
183 			   dst[i].off == 0) {
184 			was_ld_map = false;
185 			dst[i].imm = 0;
186 		} else {
187 			was_ld_map = false;
188 		}
189 	}
190 
191 	psize = bpf_prog_insn_size(fp);
192 	memset(&raw[psize], 0, raw_size - psize);
193 	raw[psize++] = 0x80;
194 
195 	bsize  = round_up(psize, SHA_MESSAGE_BYTES);
196 	blocks = bsize / SHA_MESSAGE_BYTES;
197 	todo   = raw;
198 	if (bsize - psize >= sizeof(__be64)) {
199 		bits = (__be64 *)(todo + bsize - sizeof(__be64));
200 	} else {
201 		bits = (__be64 *)(todo + bsize + bits_offset);
202 		blocks++;
203 	}
204 	*bits = cpu_to_be64((psize - 1) << 3);
205 
206 	while (blocks--) {
207 		sha_transform(digest, todo, ws);
208 		todo += SHA_MESSAGE_BYTES;
209 	}
210 
211 	result = (__force __be32 *)digest;
212 	for (i = 0; i < SHA_DIGEST_WORDS; i++)
213 		result[i] = cpu_to_be32(digest[i]);
214 	memcpy(fp->tag, result, sizeof(fp->tag));
215 
216 	vfree(raw);
217 	return 0;
218 }
219 
220 static bool bpf_is_jmp_and_has_target(const struct bpf_insn *insn)
221 {
222 	return BPF_CLASS(insn->code) == BPF_JMP  &&
223 	       /* Call and Exit are both special jumps with no
224 		* target inside the BPF instruction image.
225 		*/
226 	       BPF_OP(insn->code) != BPF_CALL &&
227 	       BPF_OP(insn->code) != BPF_EXIT;
228 }
229 
230 static void bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta)
231 {
232 	struct bpf_insn *insn = prog->insnsi;
233 	u32 i, insn_cnt = prog->len;
234 
235 	for (i = 0; i < insn_cnt; i++, insn++) {
236 		if (!bpf_is_jmp_and_has_target(insn))
237 			continue;
238 
239 		/* Adjust offset of jmps if we cross boundaries. */
240 		if (i < pos && i + insn->off + 1 > pos)
241 			insn->off += delta;
242 		else if (i > pos + delta && i + insn->off + 1 <= pos + delta)
243 			insn->off -= delta;
244 	}
245 }
246 
247 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
248 				       const struct bpf_insn *patch, u32 len)
249 {
250 	u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
251 	struct bpf_prog *prog_adj;
252 
253 	/* Since our patchlet doesn't expand the image, we're done. */
254 	if (insn_delta == 0) {
255 		memcpy(prog->insnsi + off, patch, sizeof(*patch));
256 		return prog;
257 	}
258 
259 	insn_adj_cnt = prog->len + insn_delta;
260 
261 	/* Several new instructions need to be inserted. Make room
262 	 * for them. Likely, there's no need for a new allocation as
263 	 * last page could have large enough tailroom.
264 	 */
265 	prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
266 				    GFP_USER);
267 	if (!prog_adj)
268 		return NULL;
269 
270 	prog_adj->len = insn_adj_cnt;
271 
272 	/* Patching happens in 3 steps:
273 	 *
274 	 * 1) Move over tail of insnsi from next instruction onwards,
275 	 *    so we can patch the single target insn with one or more
276 	 *    new ones (patching is always from 1 to n insns, n > 0).
277 	 * 2) Inject new instructions at the target location.
278 	 * 3) Adjust branch offsets if necessary.
279 	 */
280 	insn_rest = insn_adj_cnt - off - len;
281 
282 	memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
283 		sizeof(*patch) * insn_rest);
284 	memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
285 
286 	bpf_adj_branches(prog_adj, off, insn_delta);
287 
288 	return prog_adj;
289 }
290 
291 #ifdef CONFIG_BPF_JIT
292 static __always_inline void
293 bpf_get_prog_addr_region(const struct bpf_prog *prog,
294 			 unsigned long *symbol_start,
295 			 unsigned long *symbol_end)
296 {
297 	const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog);
298 	unsigned long addr = (unsigned long)hdr;
299 
300 	WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
301 
302 	*symbol_start = addr;
303 	*symbol_end   = addr + hdr->pages * PAGE_SIZE;
304 }
305 
306 static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
307 {
308 	const char *end = sym + KSYM_NAME_LEN;
309 
310 	BUILD_BUG_ON(sizeof("bpf_prog_") +
311 		     sizeof(prog->tag) * 2 +
312 		     /* name has been null terminated.
313 		      * We should need +1 for the '_' preceding
314 		      * the name.  However, the null character
315 		      * is double counted between the name and the
316 		      * sizeof("bpf_prog_") above, so we omit
317 		      * the +1 here.
318 		      */
319 		     sizeof(prog->aux->name) > KSYM_NAME_LEN);
320 
321 	sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
322 	sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
323 	if (prog->aux->name[0])
324 		snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
325 	else
326 		*sym = 0;
327 }
328 
329 static __always_inline unsigned long
330 bpf_get_prog_addr_start(struct latch_tree_node *n)
331 {
332 	unsigned long symbol_start, symbol_end;
333 	const struct bpf_prog_aux *aux;
334 
335 	aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
336 	bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
337 
338 	return symbol_start;
339 }
340 
341 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
342 					  struct latch_tree_node *b)
343 {
344 	return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b);
345 }
346 
347 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
348 {
349 	unsigned long val = (unsigned long)key;
350 	unsigned long symbol_start, symbol_end;
351 	const struct bpf_prog_aux *aux;
352 
353 	aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
354 	bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
355 
356 	if (val < symbol_start)
357 		return -1;
358 	if (val >= symbol_end)
359 		return  1;
360 
361 	return 0;
362 }
363 
364 static const struct latch_tree_ops bpf_tree_ops = {
365 	.less	= bpf_tree_less,
366 	.comp	= bpf_tree_comp,
367 };
368 
369 static DEFINE_SPINLOCK(bpf_lock);
370 static LIST_HEAD(bpf_kallsyms);
371 static struct latch_tree_root bpf_tree __cacheline_aligned;
372 
373 int bpf_jit_kallsyms __read_mostly;
374 
375 static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux)
376 {
377 	WARN_ON_ONCE(!list_empty(&aux->ksym_lnode));
378 	list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms);
379 	latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
380 }
381 
382 static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux)
383 {
384 	if (list_empty(&aux->ksym_lnode))
385 		return;
386 
387 	latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
388 	list_del_rcu(&aux->ksym_lnode);
389 }
390 
391 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
392 {
393 	return fp->jited && !bpf_prog_was_classic(fp);
394 }
395 
396 static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp)
397 {
398 	return list_empty(&fp->aux->ksym_lnode) ||
399 	       fp->aux->ksym_lnode.prev == LIST_POISON2;
400 }
401 
402 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
403 {
404 	if (!bpf_prog_kallsyms_candidate(fp) ||
405 	    !capable(CAP_SYS_ADMIN))
406 		return;
407 
408 	spin_lock_bh(&bpf_lock);
409 	bpf_prog_ksym_node_add(fp->aux);
410 	spin_unlock_bh(&bpf_lock);
411 }
412 
413 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
414 {
415 	if (!bpf_prog_kallsyms_candidate(fp))
416 		return;
417 
418 	spin_lock_bh(&bpf_lock);
419 	bpf_prog_ksym_node_del(fp->aux);
420 	spin_unlock_bh(&bpf_lock);
421 }
422 
423 static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
424 {
425 	struct latch_tree_node *n;
426 
427 	if (!bpf_jit_kallsyms_enabled())
428 		return NULL;
429 
430 	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
431 	return n ?
432 	       container_of(n, struct bpf_prog_aux, ksym_tnode)->prog :
433 	       NULL;
434 }
435 
436 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
437 				 unsigned long *off, char *sym)
438 {
439 	unsigned long symbol_start, symbol_end;
440 	struct bpf_prog *prog;
441 	char *ret = NULL;
442 
443 	rcu_read_lock();
444 	prog = bpf_prog_kallsyms_find(addr);
445 	if (prog) {
446 		bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end);
447 		bpf_get_prog_name(prog, sym);
448 
449 		ret = sym;
450 		if (size)
451 			*size = symbol_end - symbol_start;
452 		if (off)
453 			*off  = addr - symbol_start;
454 	}
455 	rcu_read_unlock();
456 
457 	return ret;
458 }
459 
460 bool is_bpf_text_address(unsigned long addr)
461 {
462 	bool ret;
463 
464 	rcu_read_lock();
465 	ret = bpf_prog_kallsyms_find(addr) != NULL;
466 	rcu_read_unlock();
467 
468 	return ret;
469 }
470 
471 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
472 		    char *sym)
473 {
474 	unsigned long symbol_start, symbol_end;
475 	struct bpf_prog_aux *aux;
476 	unsigned int it = 0;
477 	int ret = -ERANGE;
478 
479 	if (!bpf_jit_kallsyms_enabled())
480 		return ret;
481 
482 	rcu_read_lock();
483 	list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) {
484 		if (it++ != symnum)
485 			continue;
486 
487 		bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
488 		bpf_get_prog_name(aux->prog, sym);
489 
490 		*value = symbol_start;
491 		*type  = BPF_SYM_ELF_TYPE;
492 
493 		ret = 0;
494 		break;
495 	}
496 	rcu_read_unlock();
497 
498 	return ret;
499 }
500 
501 struct bpf_binary_header *
502 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
503 		     unsigned int alignment,
504 		     bpf_jit_fill_hole_t bpf_fill_ill_insns)
505 {
506 	struct bpf_binary_header *hdr;
507 	unsigned int size, hole, start;
508 
509 	/* Most of BPF filters are really small, but if some of them
510 	 * fill a page, allow at least 128 extra bytes to insert a
511 	 * random section of illegal instructions.
512 	 */
513 	size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
514 	hdr = module_alloc(size);
515 	if (hdr == NULL)
516 		return NULL;
517 
518 	/* Fill space with illegal/arch-dep instructions. */
519 	bpf_fill_ill_insns(hdr, size);
520 
521 	hdr->pages = size / PAGE_SIZE;
522 	hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
523 		     PAGE_SIZE - sizeof(*hdr));
524 	start = (get_random_int() % hole) & ~(alignment - 1);
525 
526 	/* Leave a random number of instructions before BPF code. */
527 	*image_ptr = &hdr->image[start];
528 
529 	return hdr;
530 }
531 
532 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
533 {
534 	module_memfree(hdr);
535 }
536 
537 /* This symbol is only overridden by archs that have different
538  * requirements than the usual eBPF JITs, f.e. when they only
539  * implement cBPF JIT, do not set images read-only, etc.
540  */
541 void __weak bpf_jit_free(struct bpf_prog *fp)
542 {
543 	if (fp->jited) {
544 		struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
545 
546 		bpf_jit_binary_unlock_ro(hdr);
547 		bpf_jit_binary_free(hdr);
548 
549 		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
550 	}
551 
552 	bpf_prog_unlock_free(fp);
553 }
554 
555 int bpf_jit_harden __read_mostly;
556 
557 static int bpf_jit_blind_insn(const struct bpf_insn *from,
558 			      const struct bpf_insn *aux,
559 			      struct bpf_insn *to_buff)
560 {
561 	struct bpf_insn *to = to_buff;
562 	u32 imm_rnd = get_random_int();
563 	s16 off;
564 
565 	BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
566 	BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
567 
568 	if (from->imm == 0 &&
569 	    (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
570 	     from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
571 		*to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
572 		goto out;
573 	}
574 
575 	switch (from->code) {
576 	case BPF_ALU | BPF_ADD | BPF_K:
577 	case BPF_ALU | BPF_SUB | BPF_K:
578 	case BPF_ALU | BPF_AND | BPF_K:
579 	case BPF_ALU | BPF_OR  | BPF_K:
580 	case BPF_ALU | BPF_XOR | BPF_K:
581 	case BPF_ALU | BPF_MUL | BPF_K:
582 	case BPF_ALU | BPF_MOV | BPF_K:
583 	case BPF_ALU | BPF_DIV | BPF_K:
584 	case BPF_ALU | BPF_MOD | BPF_K:
585 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
586 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
587 		*to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
588 		break;
589 
590 	case BPF_ALU64 | BPF_ADD | BPF_K:
591 	case BPF_ALU64 | BPF_SUB | BPF_K:
592 	case BPF_ALU64 | BPF_AND | BPF_K:
593 	case BPF_ALU64 | BPF_OR  | BPF_K:
594 	case BPF_ALU64 | BPF_XOR | BPF_K:
595 	case BPF_ALU64 | BPF_MUL | BPF_K:
596 	case BPF_ALU64 | BPF_MOV | BPF_K:
597 	case BPF_ALU64 | BPF_DIV | BPF_K:
598 	case BPF_ALU64 | BPF_MOD | BPF_K:
599 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
600 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
601 		*to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
602 		break;
603 
604 	case BPF_JMP | BPF_JEQ  | BPF_K:
605 	case BPF_JMP | BPF_JNE  | BPF_K:
606 	case BPF_JMP | BPF_JGT  | BPF_K:
607 	case BPF_JMP | BPF_JLT  | BPF_K:
608 	case BPF_JMP | BPF_JGE  | BPF_K:
609 	case BPF_JMP | BPF_JLE  | BPF_K:
610 	case BPF_JMP | BPF_JSGT | BPF_K:
611 	case BPF_JMP | BPF_JSLT | BPF_K:
612 	case BPF_JMP | BPF_JSGE | BPF_K:
613 	case BPF_JMP | BPF_JSLE | BPF_K:
614 	case BPF_JMP | BPF_JSET | BPF_K:
615 		/* Accommodate for extra offset in case of a backjump. */
616 		off = from->off;
617 		if (off < 0)
618 			off -= 2;
619 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
620 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
621 		*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
622 		break;
623 
624 	case BPF_LD | BPF_ABS | BPF_W:
625 	case BPF_LD | BPF_ABS | BPF_H:
626 	case BPF_LD | BPF_ABS | BPF_B:
627 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
628 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
629 		*to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0);
630 		break;
631 
632 	case BPF_LD | BPF_IND | BPF_W:
633 	case BPF_LD | BPF_IND | BPF_H:
634 	case BPF_LD | BPF_IND | BPF_B:
635 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
636 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
637 		*to++ = BPF_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg);
638 		*to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0);
639 		break;
640 
641 	case BPF_LD | BPF_IMM | BPF_DW:
642 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
643 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
644 		*to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
645 		*to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
646 		break;
647 	case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
648 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
649 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
650 		*to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
651 		break;
652 
653 	case BPF_ST | BPF_MEM | BPF_DW:
654 	case BPF_ST | BPF_MEM | BPF_W:
655 	case BPF_ST | BPF_MEM | BPF_H:
656 	case BPF_ST | BPF_MEM | BPF_B:
657 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
658 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
659 		*to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
660 		break;
661 	}
662 out:
663 	return to - to_buff;
664 }
665 
666 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
667 					      gfp_t gfp_extra_flags)
668 {
669 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
670 	struct bpf_prog *fp;
671 
672 	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL);
673 	if (fp != NULL) {
674 		/* aux->prog still points to the fp_other one, so
675 		 * when promoting the clone to the real program,
676 		 * this still needs to be adapted.
677 		 */
678 		memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
679 	}
680 
681 	return fp;
682 }
683 
684 static void bpf_prog_clone_free(struct bpf_prog *fp)
685 {
686 	/* aux was stolen by the other clone, so we cannot free
687 	 * it from this path! It will be freed eventually by the
688 	 * other program on release.
689 	 *
690 	 * At this point, we don't need a deferred release since
691 	 * clone is guaranteed to not be locked.
692 	 */
693 	fp->aux = NULL;
694 	__bpf_prog_free(fp);
695 }
696 
697 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
698 {
699 	/* We have to repoint aux->prog to self, as we don't
700 	 * know whether fp here is the clone or the original.
701 	 */
702 	fp->aux->prog = fp;
703 	bpf_prog_clone_free(fp_other);
704 }
705 
706 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
707 {
708 	struct bpf_insn insn_buff[16], aux[2];
709 	struct bpf_prog *clone, *tmp;
710 	int insn_delta, insn_cnt;
711 	struct bpf_insn *insn;
712 	int i, rewritten;
713 
714 	if (!bpf_jit_blinding_enabled())
715 		return prog;
716 
717 	clone = bpf_prog_clone_create(prog, GFP_USER);
718 	if (!clone)
719 		return ERR_PTR(-ENOMEM);
720 
721 	insn_cnt = clone->len;
722 	insn = clone->insnsi;
723 
724 	for (i = 0; i < insn_cnt; i++, insn++) {
725 		/* We temporarily need to hold the original ld64 insn
726 		 * so that we can still access the first part in the
727 		 * second blinding run.
728 		 */
729 		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
730 		    insn[1].code == 0)
731 			memcpy(aux, insn, sizeof(aux));
732 
733 		rewritten = bpf_jit_blind_insn(insn, aux, insn_buff);
734 		if (!rewritten)
735 			continue;
736 
737 		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
738 		if (!tmp) {
739 			/* Patching may have repointed aux->prog during
740 			 * realloc from the original one, so we need to
741 			 * fix it up here on error.
742 			 */
743 			bpf_jit_prog_release_other(prog, clone);
744 			return ERR_PTR(-ENOMEM);
745 		}
746 
747 		clone = tmp;
748 		insn_delta = rewritten - 1;
749 
750 		/* Walk new program and skip insns we just inserted. */
751 		insn = clone->insnsi + i + insn_delta;
752 		insn_cnt += insn_delta;
753 		i        += insn_delta;
754 	}
755 
756 	return clone;
757 }
758 #endif /* CONFIG_BPF_JIT */
759 
760 /* Base function for offset calculation. Needs to go into .text section,
761  * therefore keeping it non-static as well; will also be used by JITs
762  * anyway later on, so do not let the compiler omit it.
763  */
764 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
765 {
766 	return 0;
767 }
768 EXPORT_SYMBOL_GPL(__bpf_call_base);
769 
770 /**
771  *	__bpf_prog_run - run eBPF program on a given context
772  *	@ctx: is the data we are operating on
773  *	@insn: is the array of eBPF instructions
774  *
775  * Decode and execute eBPF instructions.
776  */
777 static unsigned int ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn,
778 				    u64 *stack)
779 {
780 	u64 tmp;
781 	static const void *jumptable[256] = {
782 		[0 ... 255] = &&default_label,
783 		/* Now overwrite non-defaults ... */
784 		/* 32 bit ALU operations */
785 		[BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X,
786 		[BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K,
787 		[BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X,
788 		[BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K,
789 		[BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X,
790 		[BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K,
791 		[BPF_ALU | BPF_OR | BPF_X]  = &&ALU_OR_X,
792 		[BPF_ALU | BPF_OR | BPF_K]  = &&ALU_OR_K,
793 		[BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X,
794 		[BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K,
795 		[BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X,
796 		[BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K,
797 		[BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X,
798 		[BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K,
799 		[BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X,
800 		[BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K,
801 		[BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X,
802 		[BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K,
803 		[BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X,
804 		[BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K,
805 		[BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X,
806 		[BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K,
807 		[BPF_ALU | BPF_NEG] = &&ALU_NEG,
808 		[BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE,
809 		[BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE,
810 		/* 64 bit ALU operations */
811 		[BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X,
812 		[BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K,
813 		[BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X,
814 		[BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K,
815 		[BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X,
816 		[BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K,
817 		[BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X,
818 		[BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K,
819 		[BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X,
820 		[BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K,
821 		[BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X,
822 		[BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K,
823 		[BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X,
824 		[BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K,
825 		[BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X,
826 		[BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K,
827 		[BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X,
828 		[BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K,
829 		[BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X,
830 		[BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K,
831 		[BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X,
832 		[BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K,
833 		[BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X,
834 		[BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K,
835 		[BPF_ALU64 | BPF_NEG] = &&ALU64_NEG,
836 		/* Call instruction */
837 		[BPF_JMP | BPF_CALL] = &&JMP_CALL,
838 		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
839 		/* Jumps */
840 		[BPF_JMP | BPF_JA] = &&JMP_JA,
841 		[BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X,
842 		[BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K,
843 		[BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X,
844 		[BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K,
845 		[BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X,
846 		[BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K,
847 		[BPF_JMP | BPF_JLT | BPF_X] = &&JMP_JLT_X,
848 		[BPF_JMP | BPF_JLT | BPF_K] = &&JMP_JLT_K,
849 		[BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X,
850 		[BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K,
851 		[BPF_JMP | BPF_JLE | BPF_X] = &&JMP_JLE_X,
852 		[BPF_JMP | BPF_JLE | BPF_K] = &&JMP_JLE_K,
853 		[BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X,
854 		[BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K,
855 		[BPF_JMP | BPF_JSLT | BPF_X] = &&JMP_JSLT_X,
856 		[BPF_JMP | BPF_JSLT | BPF_K] = &&JMP_JSLT_K,
857 		[BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X,
858 		[BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K,
859 		[BPF_JMP | BPF_JSLE | BPF_X] = &&JMP_JSLE_X,
860 		[BPF_JMP | BPF_JSLE | BPF_K] = &&JMP_JSLE_K,
861 		[BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X,
862 		[BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K,
863 		/* Program return */
864 		[BPF_JMP | BPF_EXIT] = &&JMP_EXIT,
865 		/* Store instructions */
866 		[BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B,
867 		[BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H,
868 		[BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W,
869 		[BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW,
870 		[BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W,
871 		[BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW,
872 		[BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B,
873 		[BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H,
874 		[BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W,
875 		[BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW,
876 		/* Load instructions */
877 		[BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B,
878 		[BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H,
879 		[BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W,
880 		[BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW,
881 		[BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W,
882 		[BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H,
883 		[BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B,
884 		[BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W,
885 		[BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H,
886 		[BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B,
887 		[BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW,
888 	};
889 	u32 tail_call_cnt = 0;
890 	void *ptr;
891 	int off;
892 
893 #define CONT	 ({ insn++; goto select_insn; })
894 #define CONT_JMP ({ insn++; goto select_insn; })
895 
896 select_insn:
897 	goto *jumptable[insn->code];
898 
899 	/* ALU */
900 #define ALU(OPCODE, OP)			\
901 	ALU64_##OPCODE##_X:		\
902 		DST = DST OP SRC;	\
903 		CONT;			\
904 	ALU_##OPCODE##_X:		\
905 		DST = (u32) DST OP (u32) SRC;	\
906 		CONT;			\
907 	ALU64_##OPCODE##_K:		\
908 		DST = DST OP IMM;		\
909 		CONT;			\
910 	ALU_##OPCODE##_K:		\
911 		DST = (u32) DST OP (u32) IMM;	\
912 		CONT;
913 
914 	ALU(ADD,  +)
915 	ALU(SUB,  -)
916 	ALU(AND,  &)
917 	ALU(OR,   |)
918 	ALU(LSH, <<)
919 	ALU(RSH, >>)
920 	ALU(XOR,  ^)
921 	ALU(MUL,  *)
922 #undef ALU
923 	ALU_NEG:
924 		DST = (u32) -DST;
925 		CONT;
926 	ALU64_NEG:
927 		DST = -DST;
928 		CONT;
929 	ALU_MOV_X:
930 		DST = (u32) SRC;
931 		CONT;
932 	ALU_MOV_K:
933 		DST = (u32) IMM;
934 		CONT;
935 	ALU64_MOV_X:
936 		DST = SRC;
937 		CONT;
938 	ALU64_MOV_K:
939 		DST = IMM;
940 		CONT;
941 	LD_IMM_DW:
942 		DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
943 		insn++;
944 		CONT;
945 	ALU64_ARSH_X:
946 		(*(s64 *) &DST) >>= SRC;
947 		CONT;
948 	ALU64_ARSH_K:
949 		(*(s64 *) &DST) >>= IMM;
950 		CONT;
951 	ALU64_MOD_X:
952 		if (unlikely(SRC == 0))
953 			return 0;
954 		div64_u64_rem(DST, SRC, &tmp);
955 		DST = tmp;
956 		CONT;
957 	ALU_MOD_X:
958 		if (unlikely(SRC == 0))
959 			return 0;
960 		tmp = (u32) DST;
961 		DST = do_div(tmp, (u32) SRC);
962 		CONT;
963 	ALU64_MOD_K:
964 		div64_u64_rem(DST, IMM, &tmp);
965 		DST = tmp;
966 		CONT;
967 	ALU_MOD_K:
968 		tmp = (u32) DST;
969 		DST = do_div(tmp, (u32) IMM);
970 		CONT;
971 	ALU64_DIV_X:
972 		if (unlikely(SRC == 0))
973 			return 0;
974 		DST = div64_u64(DST, SRC);
975 		CONT;
976 	ALU_DIV_X:
977 		if (unlikely(SRC == 0))
978 			return 0;
979 		tmp = (u32) DST;
980 		do_div(tmp, (u32) SRC);
981 		DST = (u32) tmp;
982 		CONT;
983 	ALU64_DIV_K:
984 		DST = div64_u64(DST, IMM);
985 		CONT;
986 	ALU_DIV_K:
987 		tmp = (u32) DST;
988 		do_div(tmp, (u32) IMM);
989 		DST = (u32) tmp;
990 		CONT;
991 	ALU_END_TO_BE:
992 		switch (IMM) {
993 		case 16:
994 			DST = (__force u16) cpu_to_be16(DST);
995 			break;
996 		case 32:
997 			DST = (__force u32) cpu_to_be32(DST);
998 			break;
999 		case 64:
1000 			DST = (__force u64) cpu_to_be64(DST);
1001 			break;
1002 		}
1003 		CONT;
1004 	ALU_END_TO_LE:
1005 		switch (IMM) {
1006 		case 16:
1007 			DST = (__force u16) cpu_to_le16(DST);
1008 			break;
1009 		case 32:
1010 			DST = (__force u32) cpu_to_le32(DST);
1011 			break;
1012 		case 64:
1013 			DST = (__force u64) cpu_to_le64(DST);
1014 			break;
1015 		}
1016 		CONT;
1017 
1018 	/* CALL */
1019 	JMP_CALL:
1020 		/* Function call scratches BPF_R1-BPF_R5 registers,
1021 		 * preserves BPF_R6-BPF_R9, and stores return value
1022 		 * into BPF_R0.
1023 		 */
1024 		BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1025 						       BPF_R4, BPF_R5);
1026 		CONT;
1027 
1028 	JMP_TAIL_CALL: {
1029 		struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1030 		struct bpf_array *array = container_of(map, struct bpf_array, map);
1031 		struct bpf_prog *prog;
1032 		u32 index = BPF_R3;
1033 
1034 		if (unlikely(index >= array->map.max_entries))
1035 			goto out;
1036 		if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT))
1037 			goto out;
1038 
1039 		tail_call_cnt++;
1040 
1041 		prog = READ_ONCE(array->ptrs[index]);
1042 		if (!prog)
1043 			goto out;
1044 
1045 		/* ARG1 at this point is guaranteed to point to CTX from
1046 		 * the verifier side due to the fact that the tail call is
1047 		 * handeled like a helper, that is, bpf_tail_call_proto,
1048 		 * where arg1_type is ARG_PTR_TO_CTX.
1049 		 */
1050 		insn = prog->insnsi;
1051 		goto select_insn;
1052 out:
1053 		CONT;
1054 	}
1055 	/* JMP */
1056 	JMP_JA:
1057 		insn += insn->off;
1058 		CONT;
1059 	JMP_JEQ_X:
1060 		if (DST == SRC) {
1061 			insn += insn->off;
1062 			CONT_JMP;
1063 		}
1064 		CONT;
1065 	JMP_JEQ_K:
1066 		if (DST == IMM) {
1067 			insn += insn->off;
1068 			CONT_JMP;
1069 		}
1070 		CONT;
1071 	JMP_JNE_X:
1072 		if (DST != SRC) {
1073 			insn += insn->off;
1074 			CONT_JMP;
1075 		}
1076 		CONT;
1077 	JMP_JNE_K:
1078 		if (DST != IMM) {
1079 			insn += insn->off;
1080 			CONT_JMP;
1081 		}
1082 		CONT;
1083 	JMP_JGT_X:
1084 		if (DST > SRC) {
1085 			insn += insn->off;
1086 			CONT_JMP;
1087 		}
1088 		CONT;
1089 	JMP_JGT_K:
1090 		if (DST > IMM) {
1091 			insn += insn->off;
1092 			CONT_JMP;
1093 		}
1094 		CONT;
1095 	JMP_JLT_X:
1096 		if (DST < SRC) {
1097 			insn += insn->off;
1098 			CONT_JMP;
1099 		}
1100 		CONT;
1101 	JMP_JLT_K:
1102 		if (DST < IMM) {
1103 			insn += insn->off;
1104 			CONT_JMP;
1105 		}
1106 		CONT;
1107 	JMP_JGE_X:
1108 		if (DST >= SRC) {
1109 			insn += insn->off;
1110 			CONT_JMP;
1111 		}
1112 		CONT;
1113 	JMP_JGE_K:
1114 		if (DST >= IMM) {
1115 			insn += insn->off;
1116 			CONT_JMP;
1117 		}
1118 		CONT;
1119 	JMP_JLE_X:
1120 		if (DST <= SRC) {
1121 			insn += insn->off;
1122 			CONT_JMP;
1123 		}
1124 		CONT;
1125 	JMP_JLE_K:
1126 		if (DST <= IMM) {
1127 			insn += insn->off;
1128 			CONT_JMP;
1129 		}
1130 		CONT;
1131 	JMP_JSGT_X:
1132 		if (((s64) DST) > ((s64) SRC)) {
1133 			insn += insn->off;
1134 			CONT_JMP;
1135 		}
1136 		CONT;
1137 	JMP_JSGT_K:
1138 		if (((s64) DST) > ((s64) IMM)) {
1139 			insn += insn->off;
1140 			CONT_JMP;
1141 		}
1142 		CONT;
1143 	JMP_JSLT_X:
1144 		if (((s64) DST) < ((s64) SRC)) {
1145 			insn += insn->off;
1146 			CONT_JMP;
1147 		}
1148 		CONT;
1149 	JMP_JSLT_K:
1150 		if (((s64) DST) < ((s64) IMM)) {
1151 			insn += insn->off;
1152 			CONT_JMP;
1153 		}
1154 		CONT;
1155 	JMP_JSGE_X:
1156 		if (((s64) DST) >= ((s64) SRC)) {
1157 			insn += insn->off;
1158 			CONT_JMP;
1159 		}
1160 		CONT;
1161 	JMP_JSGE_K:
1162 		if (((s64) DST) >= ((s64) IMM)) {
1163 			insn += insn->off;
1164 			CONT_JMP;
1165 		}
1166 		CONT;
1167 	JMP_JSLE_X:
1168 		if (((s64) DST) <= ((s64) SRC)) {
1169 			insn += insn->off;
1170 			CONT_JMP;
1171 		}
1172 		CONT;
1173 	JMP_JSLE_K:
1174 		if (((s64) DST) <= ((s64) IMM)) {
1175 			insn += insn->off;
1176 			CONT_JMP;
1177 		}
1178 		CONT;
1179 	JMP_JSET_X:
1180 		if (DST & SRC) {
1181 			insn += insn->off;
1182 			CONT_JMP;
1183 		}
1184 		CONT;
1185 	JMP_JSET_K:
1186 		if (DST & IMM) {
1187 			insn += insn->off;
1188 			CONT_JMP;
1189 		}
1190 		CONT;
1191 	JMP_EXIT:
1192 		return BPF_R0;
1193 
1194 	/* STX and ST and LDX*/
1195 #define LDST(SIZEOP, SIZE)						\
1196 	STX_MEM_##SIZEOP:						\
1197 		*(SIZE *)(unsigned long) (DST + insn->off) = SRC;	\
1198 		CONT;							\
1199 	ST_MEM_##SIZEOP:						\
1200 		*(SIZE *)(unsigned long) (DST + insn->off) = IMM;	\
1201 		CONT;							\
1202 	LDX_MEM_##SIZEOP:						\
1203 		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
1204 		CONT;
1205 
1206 	LDST(B,   u8)
1207 	LDST(H,  u16)
1208 	LDST(W,  u32)
1209 	LDST(DW, u64)
1210 #undef LDST
1211 	STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
1212 		atomic_add((u32) SRC, (atomic_t *)(unsigned long)
1213 			   (DST + insn->off));
1214 		CONT;
1215 	STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */
1216 		atomic64_add((u64) SRC, (atomic64_t *)(unsigned long)
1217 			     (DST + insn->off));
1218 		CONT;
1219 	LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */
1220 		off = IMM;
1221 load_word:
1222 		/* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are only
1223 		 * appearing in the programs where ctx == skb
1224 		 * (see may_access_skb() in the verifier). All programs
1225 		 * keep 'ctx' in regs[BPF_REG_CTX] == BPF_R6,
1226 		 * bpf_convert_filter() saves it in BPF_R6, internal BPF
1227 		 * verifier will check that BPF_R6 == ctx.
1228 		 *
1229 		 * BPF_ABS and BPF_IND are wrappers of function calls,
1230 		 * so they scratch BPF_R1-BPF_R5 registers, preserve
1231 		 * BPF_R6-BPF_R9, and store return value into BPF_R0.
1232 		 *
1233 		 * Implicit input:
1234 		 *   ctx == skb == BPF_R6 == CTX
1235 		 *
1236 		 * Explicit input:
1237 		 *   SRC == any register
1238 		 *   IMM == 32-bit immediate
1239 		 *
1240 		 * Output:
1241 		 *   BPF_R0 - 8/16/32-bit skb data converted to cpu endianness
1242 		 */
1243 
1244 		ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp);
1245 		if (likely(ptr != NULL)) {
1246 			BPF_R0 = get_unaligned_be32(ptr);
1247 			CONT;
1248 		}
1249 
1250 		return 0;
1251 	LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */
1252 		off = IMM;
1253 load_half:
1254 		ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp);
1255 		if (likely(ptr != NULL)) {
1256 			BPF_R0 = get_unaligned_be16(ptr);
1257 			CONT;
1258 		}
1259 
1260 		return 0;
1261 	LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */
1262 		off = IMM;
1263 load_byte:
1264 		ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp);
1265 		if (likely(ptr != NULL)) {
1266 			BPF_R0 = *(u8 *)ptr;
1267 			CONT;
1268 		}
1269 
1270 		return 0;
1271 	LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */
1272 		off = IMM + SRC;
1273 		goto load_word;
1274 	LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */
1275 		off = IMM + SRC;
1276 		goto load_half;
1277 	LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */
1278 		off = IMM + SRC;
1279 		goto load_byte;
1280 
1281 	default_label:
1282 		/* If we ever reach this, we have a bug somewhere. */
1283 		WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code);
1284 		return 0;
1285 }
1286 STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */
1287 
1288 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
1289 #define DEFINE_BPF_PROG_RUN(stack_size) \
1290 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
1291 { \
1292 	u64 stack[stack_size / sizeof(u64)]; \
1293 	u64 regs[MAX_BPF_REG]; \
1294 \
1295 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
1296 	ARG1 = (u64) (unsigned long) ctx; \
1297 	return ___bpf_prog_run(regs, insn, stack); \
1298 }
1299 
1300 #define EVAL1(FN, X) FN(X)
1301 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
1302 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
1303 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
1304 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
1305 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
1306 
1307 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
1308 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
1309 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
1310 
1311 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
1312 
1313 static unsigned int (*interpreters[])(const void *ctx,
1314 				      const struct bpf_insn *insn) = {
1315 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
1316 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
1317 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
1318 };
1319 
1320 bool bpf_prog_array_compatible(struct bpf_array *array,
1321 			       const struct bpf_prog *fp)
1322 {
1323 	if (!array->owner_prog_type) {
1324 		/* There's no owner yet where we could check for
1325 		 * compatibility.
1326 		 */
1327 		array->owner_prog_type = fp->type;
1328 		array->owner_jited = fp->jited;
1329 
1330 		return true;
1331 	}
1332 
1333 	return array->owner_prog_type == fp->type &&
1334 	       array->owner_jited == fp->jited;
1335 }
1336 
1337 static int bpf_check_tail_call(const struct bpf_prog *fp)
1338 {
1339 	struct bpf_prog_aux *aux = fp->aux;
1340 	int i;
1341 
1342 	for (i = 0; i < aux->used_map_cnt; i++) {
1343 		struct bpf_map *map = aux->used_maps[i];
1344 		struct bpf_array *array;
1345 
1346 		if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
1347 			continue;
1348 
1349 		array = container_of(map, struct bpf_array, map);
1350 		if (!bpf_prog_array_compatible(array, fp))
1351 			return -EINVAL;
1352 	}
1353 
1354 	return 0;
1355 }
1356 
1357 /**
1358  *	bpf_prog_select_runtime - select exec runtime for BPF program
1359  *	@fp: bpf_prog populated with internal BPF program
1360  *	@err: pointer to error variable
1361  *
1362  * Try to JIT eBPF program, if JIT is not available, use interpreter.
1363  * The BPF program will be executed via BPF_PROG_RUN() macro.
1364  */
1365 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
1366 {
1367 	u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
1368 
1369 	fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
1370 
1371 	/* eBPF JITs can rewrite the program in case constant
1372 	 * blinding is active. However, in case of error during
1373 	 * blinding, bpf_int_jit_compile() must always return a
1374 	 * valid program, which in this case would simply not
1375 	 * be JITed, but falls back to the interpreter.
1376 	 */
1377 	if (!bpf_prog_is_dev_bound(fp->aux)) {
1378 		fp = bpf_int_jit_compile(fp);
1379 	} else {
1380 		*err = bpf_prog_offload_compile(fp);
1381 		if (*err)
1382 			return fp;
1383 	}
1384 	bpf_prog_lock_ro(fp);
1385 
1386 	/* The tail call compatibility check can only be done at
1387 	 * this late stage as we need to determine, if we deal
1388 	 * with JITed or non JITed program concatenations and not
1389 	 * all eBPF JITs might immediately support all features.
1390 	 */
1391 	*err = bpf_check_tail_call(fp);
1392 
1393 	return fp;
1394 }
1395 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
1396 
1397 static unsigned int __bpf_prog_ret1(const void *ctx,
1398 				    const struct bpf_insn *insn)
1399 {
1400 	return 1;
1401 }
1402 
1403 static struct bpf_prog_dummy {
1404 	struct bpf_prog prog;
1405 } dummy_bpf_prog = {
1406 	.prog = {
1407 		.bpf_func = __bpf_prog_ret1,
1408 	},
1409 };
1410 
1411 /* to avoid allocating empty bpf_prog_array for cgroups that
1412  * don't have bpf program attached use one global 'empty_prog_array'
1413  * It will not be modified the caller of bpf_prog_array_alloc()
1414  * (since caller requested prog_cnt == 0)
1415  * that pointer should be 'freed' by bpf_prog_array_free()
1416  */
1417 static struct {
1418 	struct bpf_prog_array hdr;
1419 	struct bpf_prog *null_prog;
1420 } empty_prog_array = {
1421 	.null_prog = NULL,
1422 };
1423 
1424 struct bpf_prog_array __rcu *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
1425 {
1426 	if (prog_cnt)
1427 		return kzalloc(sizeof(struct bpf_prog_array) +
1428 			       sizeof(struct bpf_prog *) * (prog_cnt + 1),
1429 			       flags);
1430 
1431 	return &empty_prog_array.hdr;
1432 }
1433 
1434 void bpf_prog_array_free(struct bpf_prog_array __rcu *progs)
1435 {
1436 	if (!progs ||
1437 	    progs == (struct bpf_prog_array __rcu *)&empty_prog_array.hdr)
1438 		return;
1439 	kfree_rcu(progs, rcu);
1440 }
1441 
1442 int bpf_prog_array_length(struct bpf_prog_array __rcu *progs)
1443 {
1444 	struct bpf_prog **prog;
1445 	u32 cnt = 0;
1446 
1447 	rcu_read_lock();
1448 	prog = rcu_dereference(progs)->progs;
1449 	for (; *prog; prog++)
1450 		if (*prog != &dummy_bpf_prog.prog)
1451 			cnt++;
1452 	rcu_read_unlock();
1453 	return cnt;
1454 }
1455 
1456 int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
1457 				__u32 __user *prog_ids, u32 cnt)
1458 {
1459 	struct bpf_prog **prog;
1460 	u32 i = 0, id;
1461 
1462 	rcu_read_lock();
1463 	prog = rcu_dereference(progs)->progs;
1464 	for (; *prog; prog++) {
1465 		id = (*prog)->aux->id;
1466 		if (copy_to_user(prog_ids + i, &id, sizeof(id))) {
1467 			rcu_read_unlock();
1468 			return -EFAULT;
1469 		}
1470 		if (++i == cnt) {
1471 			prog++;
1472 			break;
1473 		}
1474 	}
1475 	rcu_read_unlock();
1476 	if (*prog)
1477 		return -ENOSPC;
1478 	return 0;
1479 }
1480 
1481 void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *progs,
1482 				struct bpf_prog *old_prog)
1483 {
1484 	struct bpf_prog **prog = progs->progs;
1485 
1486 	for (; *prog; prog++)
1487 		if (*prog == old_prog) {
1488 			WRITE_ONCE(*prog, &dummy_bpf_prog.prog);
1489 			break;
1490 		}
1491 }
1492 
1493 int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
1494 			struct bpf_prog *exclude_prog,
1495 			struct bpf_prog *include_prog,
1496 			struct bpf_prog_array **new_array)
1497 {
1498 	int new_prog_cnt, carry_prog_cnt = 0;
1499 	struct bpf_prog **existing_prog;
1500 	struct bpf_prog_array *array;
1501 	int new_prog_idx = 0;
1502 
1503 	/* Figure out how many existing progs we need to carry over to
1504 	 * the new array.
1505 	 */
1506 	if (old_array) {
1507 		existing_prog = old_array->progs;
1508 		for (; *existing_prog; existing_prog++) {
1509 			if (*existing_prog != exclude_prog &&
1510 			    *existing_prog != &dummy_bpf_prog.prog)
1511 				carry_prog_cnt++;
1512 			if (*existing_prog == include_prog)
1513 				return -EEXIST;
1514 		}
1515 	}
1516 
1517 	/* How many progs (not NULL) will be in the new array? */
1518 	new_prog_cnt = carry_prog_cnt;
1519 	if (include_prog)
1520 		new_prog_cnt += 1;
1521 
1522 	/* Do we have any prog (not NULL) in the new array? */
1523 	if (!new_prog_cnt) {
1524 		*new_array = NULL;
1525 		return 0;
1526 	}
1527 
1528 	/* +1 as the end of prog_array is marked with NULL */
1529 	array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
1530 	if (!array)
1531 		return -ENOMEM;
1532 
1533 	/* Fill in the new prog array */
1534 	if (carry_prog_cnt) {
1535 		existing_prog = old_array->progs;
1536 		for (; *existing_prog; existing_prog++)
1537 			if (*existing_prog != exclude_prog &&
1538 			    *existing_prog != &dummy_bpf_prog.prog)
1539 				array->progs[new_prog_idx++] = *existing_prog;
1540 	}
1541 	if (include_prog)
1542 		array->progs[new_prog_idx++] = include_prog;
1543 	array->progs[new_prog_idx] = NULL;
1544 	*new_array = array;
1545 	return 0;
1546 }
1547 
1548 static void bpf_prog_free_deferred(struct work_struct *work)
1549 {
1550 	struct bpf_prog_aux *aux;
1551 
1552 	aux = container_of(work, struct bpf_prog_aux, work);
1553 	if (bpf_prog_is_dev_bound(aux))
1554 		bpf_prog_offload_destroy(aux->prog);
1555 	bpf_jit_free(aux->prog);
1556 }
1557 
1558 /* Free internal BPF program */
1559 void bpf_prog_free(struct bpf_prog *fp)
1560 {
1561 	struct bpf_prog_aux *aux = fp->aux;
1562 
1563 	INIT_WORK(&aux->work, bpf_prog_free_deferred);
1564 	schedule_work(&aux->work);
1565 }
1566 EXPORT_SYMBOL_GPL(bpf_prog_free);
1567 
1568 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
1569 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
1570 
1571 void bpf_user_rnd_init_once(void)
1572 {
1573 	prandom_init_once(&bpf_user_rnd_state);
1574 }
1575 
1576 BPF_CALL_0(bpf_user_rnd_u32)
1577 {
1578 	/* Should someone ever have the rather unwise idea to use some
1579 	 * of the registers passed into this function, then note that
1580 	 * this function is called from native eBPF and classic-to-eBPF
1581 	 * transformations. Register assignments from both sides are
1582 	 * different, f.e. classic always sets fn(ctx, A, X) here.
1583 	 */
1584 	struct rnd_state *state;
1585 	u32 res;
1586 
1587 	state = &get_cpu_var(bpf_user_rnd_state);
1588 	res = prandom_u32_state(state);
1589 	put_cpu_var(bpf_user_rnd_state);
1590 
1591 	return res;
1592 }
1593 
1594 /* Weak definitions of helper functions in case we don't have bpf syscall. */
1595 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
1596 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
1597 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
1598 
1599 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
1600 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
1601 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
1602 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
1603 
1604 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
1605 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
1606 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
1607 const struct bpf_func_proto bpf_sock_map_update_proto __weak;
1608 
1609 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
1610 {
1611 	return NULL;
1612 }
1613 
1614 u64 __weak
1615 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
1616 		 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
1617 {
1618 	return -ENOTSUPP;
1619 }
1620 
1621 /* Always built-in helper functions. */
1622 const struct bpf_func_proto bpf_tail_call_proto = {
1623 	.func		= NULL,
1624 	.gpl_only	= false,
1625 	.ret_type	= RET_VOID,
1626 	.arg1_type	= ARG_PTR_TO_CTX,
1627 	.arg2_type	= ARG_CONST_MAP_PTR,
1628 	.arg3_type	= ARG_ANYTHING,
1629 };
1630 
1631 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
1632  * It is encouraged to implement bpf_int_jit_compile() instead, so that
1633  * eBPF and implicitly also cBPF can get JITed!
1634  */
1635 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
1636 {
1637 	return prog;
1638 }
1639 
1640 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
1641  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
1642  */
1643 void __weak bpf_jit_compile(struct bpf_prog *prog)
1644 {
1645 }
1646 
1647 bool __weak bpf_helper_changes_pkt_data(void *func)
1648 {
1649 	return false;
1650 }
1651 
1652 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
1653  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
1654  */
1655 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
1656 			 int len)
1657 {
1658 	return -EFAULT;
1659 }
1660 
1661 /* All definitions of tracepoints related to BPF. */
1662 #define CREATE_TRACE_POINTS
1663 #include <linux/bpf_trace.h>
1664 
1665 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
1666 
1667 /* These are only used within the BPF_SYSCALL code */
1668 #ifdef CONFIG_BPF_SYSCALL
1669 EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_get_type);
1670 EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_put_rcu);
1671 #endif
1672