xref: /openbmc/linux/kernel/bpf/core.c (revision 5d0e4d78)
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 	kmemcheck_annotate_bitfield(fp, meta);
89 
90 	aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
91 	if (aux == NULL) {
92 		vfree(fp);
93 		return NULL;
94 	}
95 
96 	fp->pages = size / PAGE_SIZE;
97 	fp->aux = aux;
98 	fp->aux->prog = fp;
99 
100 	INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode);
101 
102 	return fp;
103 }
104 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
105 
106 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
107 				  gfp_t gfp_extra_flags)
108 {
109 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
110 	struct bpf_prog *fp;
111 	u32 pages, delta;
112 	int ret;
113 
114 	BUG_ON(fp_old == NULL);
115 
116 	size = round_up(size, PAGE_SIZE);
117 	pages = size / PAGE_SIZE;
118 	if (pages <= fp_old->pages)
119 		return fp_old;
120 
121 	delta = pages - fp_old->pages;
122 	ret = __bpf_prog_charge(fp_old->aux->user, delta);
123 	if (ret)
124 		return NULL;
125 
126 	fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
127 	if (fp == NULL) {
128 		__bpf_prog_uncharge(fp_old->aux->user, delta);
129 	} else {
130 		kmemcheck_annotate_bitfield(fp, meta);
131 
132 		memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
133 		fp->pages = pages;
134 		fp->aux->prog = fp;
135 
136 		/* We keep fp->aux from fp_old around in the new
137 		 * reallocated structure.
138 		 */
139 		fp_old->aux = NULL;
140 		__bpf_prog_free(fp_old);
141 	}
142 
143 	return fp;
144 }
145 
146 void __bpf_prog_free(struct bpf_prog *fp)
147 {
148 	kfree(fp->aux);
149 	vfree(fp);
150 }
151 
152 int bpf_prog_calc_tag(struct bpf_prog *fp)
153 {
154 	const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64);
155 	u32 raw_size = bpf_prog_tag_scratch_size(fp);
156 	u32 digest[SHA_DIGEST_WORDS];
157 	u32 ws[SHA_WORKSPACE_WORDS];
158 	u32 i, bsize, psize, blocks;
159 	struct bpf_insn *dst;
160 	bool was_ld_map;
161 	u8 *raw, *todo;
162 	__be32 *result;
163 	__be64 *bits;
164 
165 	raw = vmalloc(raw_size);
166 	if (!raw)
167 		return -ENOMEM;
168 
169 	sha_init(digest);
170 	memset(ws, 0, sizeof(ws));
171 
172 	/* We need to take out the map fd for the digest calculation
173 	 * since they are unstable from user space side.
174 	 */
175 	dst = (void *)raw;
176 	for (i = 0, was_ld_map = false; i < fp->len; i++) {
177 		dst[i] = fp->insnsi[i];
178 		if (!was_ld_map &&
179 		    dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
180 		    dst[i].src_reg == BPF_PSEUDO_MAP_FD) {
181 			was_ld_map = true;
182 			dst[i].imm = 0;
183 		} else if (was_ld_map &&
184 			   dst[i].code == 0 &&
185 			   dst[i].dst_reg == 0 &&
186 			   dst[i].src_reg == 0 &&
187 			   dst[i].off == 0) {
188 			was_ld_map = false;
189 			dst[i].imm = 0;
190 		} else {
191 			was_ld_map = false;
192 		}
193 	}
194 
195 	psize = bpf_prog_insn_size(fp);
196 	memset(&raw[psize], 0, raw_size - psize);
197 	raw[psize++] = 0x80;
198 
199 	bsize  = round_up(psize, SHA_MESSAGE_BYTES);
200 	blocks = bsize / SHA_MESSAGE_BYTES;
201 	todo   = raw;
202 	if (bsize - psize >= sizeof(__be64)) {
203 		bits = (__be64 *)(todo + bsize - sizeof(__be64));
204 	} else {
205 		bits = (__be64 *)(todo + bsize + bits_offset);
206 		blocks++;
207 	}
208 	*bits = cpu_to_be64((psize - 1) << 3);
209 
210 	while (blocks--) {
211 		sha_transform(digest, todo, ws);
212 		todo += SHA_MESSAGE_BYTES;
213 	}
214 
215 	result = (__force __be32 *)digest;
216 	for (i = 0; i < SHA_DIGEST_WORDS; i++)
217 		result[i] = cpu_to_be32(digest[i]);
218 	memcpy(fp->tag, result, sizeof(fp->tag));
219 
220 	vfree(raw);
221 	return 0;
222 }
223 
224 static bool bpf_is_jmp_and_has_target(const struct bpf_insn *insn)
225 {
226 	return BPF_CLASS(insn->code) == BPF_JMP  &&
227 	       /* Call and Exit are both special jumps with no
228 		* target inside the BPF instruction image.
229 		*/
230 	       BPF_OP(insn->code) != BPF_CALL &&
231 	       BPF_OP(insn->code) != BPF_EXIT;
232 }
233 
234 static void bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta)
235 {
236 	struct bpf_insn *insn = prog->insnsi;
237 	u32 i, insn_cnt = prog->len;
238 
239 	for (i = 0; i < insn_cnt; i++, insn++) {
240 		if (!bpf_is_jmp_and_has_target(insn))
241 			continue;
242 
243 		/* Adjust offset of jmps if we cross boundaries. */
244 		if (i < pos && i + insn->off + 1 > pos)
245 			insn->off += delta;
246 		else if (i > pos + delta && i + insn->off + 1 <= pos + delta)
247 			insn->off -= delta;
248 	}
249 }
250 
251 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
252 				       const struct bpf_insn *patch, u32 len)
253 {
254 	u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
255 	struct bpf_prog *prog_adj;
256 
257 	/* Since our patchlet doesn't expand the image, we're done. */
258 	if (insn_delta == 0) {
259 		memcpy(prog->insnsi + off, patch, sizeof(*patch));
260 		return prog;
261 	}
262 
263 	insn_adj_cnt = prog->len + insn_delta;
264 
265 	/* Several new instructions need to be inserted. Make room
266 	 * for them. Likely, there's no need for a new allocation as
267 	 * last page could have large enough tailroom.
268 	 */
269 	prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
270 				    GFP_USER);
271 	if (!prog_adj)
272 		return NULL;
273 
274 	prog_adj->len = insn_adj_cnt;
275 
276 	/* Patching happens in 3 steps:
277 	 *
278 	 * 1) Move over tail of insnsi from next instruction onwards,
279 	 *    so we can patch the single target insn with one or more
280 	 *    new ones (patching is always from 1 to n insns, n > 0).
281 	 * 2) Inject new instructions at the target location.
282 	 * 3) Adjust branch offsets if necessary.
283 	 */
284 	insn_rest = insn_adj_cnt - off - len;
285 
286 	memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
287 		sizeof(*patch) * insn_rest);
288 	memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
289 
290 	bpf_adj_branches(prog_adj, off, insn_delta);
291 
292 	return prog_adj;
293 }
294 
295 #ifdef CONFIG_BPF_JIT
296 static __always_inline void
297 bpf_get_prog_addr_region(const struct bpf_prog *prog,
298 			 unsigned long *symbol_start,
299 			 unsigned long *symbol_end)
300 {
301 	const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog);
302 	unsigned long addr = (unsigned long)hdr;
303 
304 	WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
305 
306 	*symbol_start = addr;
307 	*symbol_end   = addr + hdr->pages * PAGE_SIZE;
308 }
309 
310 static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
311 {
312 	BUILD_BUG_ON(sizeof("bpf_prog_") +
313 		     sizeof(prog->tag) * 2 + 1 > KSYM_NAME_LEN);
314 
315 	sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
316 	sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
317 	*sym = 0;
318 }
319 
320 static __always_inline unsigned long
321 bpf_get_prog_addr_start(struct latch_tree_node *n)
322 {
323 	unsigned long symbol_start, symbol_end;
324 	const struct bpf_prog_aux *aux;
325 
326 	aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
327 	bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
328 
329 	return symbol_start;
330 }
331 
332 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
333 					  struct latch_tree_node *b)
334 {
335 	return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b);
336 }
337 
338 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
339 {
340 	unsigned long val = (unsigned long)key;
341 	unsigned long symbol_start, symbol_end;
342 	const struct bpf_prog_aux *aux;
343 
344 	aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
345 	bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
346 
347 	if (val < symbol_start)
348 		return -1;
349 	if (val >= symbol_end)
350 		return  1;
351 
352 	return 0;
353 }
354 
355 static const struct latch_tree_ops bpf_tree_ops = {
356 	.less	= bpf_tree_less,
357 	.comp	= bpf_tree_comp,
358 };
359 
360 static DEFINE_SPINLOCK(bpf_lock);
361 static LIST_HEAD(bpf_kallsyms);
362 static struct latch_tree_root bpf_tree __cacheline_aligned;
363 
364 int bpf_jit_kallsyms __read_mostly;
365 
366 static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux)
367 {
368 	WARN_ON_ONCE(!list_empty(&aux->ksym_lnode));
369 	list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms);
370 	latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
371 }
372 
373 static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux)
374 {
375 	if (list_empty(&aux->ksym_lnode))
376 		return;
377 
378 	latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
379 	list_del_rcu(&aux->ksym_lnode);
380 }
381 
382 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
383 {
384 	return fp->jited && !bpf_prog_was_classic(fp);
385 }
386 
387 static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp)
388 {
389 	return list_empty(&fp->aux->ksym_lnode) ||
390 	       fp->aux->ksym_lnode.prev == LIST_POISON2;
391 }
392 
393 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
394 {
395 	if (!bpf_prog_kallsyms_candidate(fp) ||
396 	    !capable(CAP_SYS_ADMIN))
397 		return;
398 
399 	spin_lock_bh(&bpf_lock);
400 	bpf_prog_ksym_node_add(fp->aux);
401 	spin_unlock_bh(&bpf_lock);
402 }
403 
404 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
405 {
406 	if (!bpf_prog_kallsyms_candidate(fp))
407 		return;
408 
409 	spin_lock_bh(&bpf_lock);
410 	bpf_prog_ksym_node_del(fp->aux);
411 	spin_unlock_bh(&bpf_lock);
412 }
413 
414 static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
415 {
416 	struct latch_tree_node *n;
417 
418 	if (!bpf_jit_kallsyms_enabled())
419 		return NULL;
420 
421 	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
422 	return n ?
423 	       container_of(n, struct bpf_prog_aux, ksym_tnode)->prog :
424 	       NULL;
425 }
426 
427 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
428 				 unsigned long *off, char *sym)
429 {
430 	unsigned long symbol_start, symbol_end;
431 	struct bpf_prog *prog;
432 	char *ret = NULL;
433 
434 	rcu_read_lock();
435 	prog = bpf_prog_kallsyms_find(addr);
436 	if (prog) {
437 		bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end);
438 		bpf_get_prog_name(prog, sym);
439 
440 		ret = sym;
441 		if (size)
442 			*size = symbol_end - symbol_start;
443 		if (off)
444 			*off  = addr - symbol_start;
445 	}
446 	rcu_read_unlock();
447 
448 	return ret;
449 }
450 
451 bool is_bpf_text_address(unsigned long addr)
452 {
453 	bool ret;
454 
455 	rcu_read_lock();
456 	ret = bpf_prog_kallsyms_find(addr) != NULL;
457 	rcu_read_unlock();
458 
459 	return ret;
460 }
461 
462 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
463 		    char *sym)
464 {
465 	unsigned long symbol_start, symbol_end;
466 	struct bpf_prog_aux *aux;
467 	unsigned int it = 0;
468 	int ret = -ERANGE;
469 
470 	if (!bpf_jit_kallsyms_enabled())
471 		return ret;
472 
473 	rcu_read_lock();
474 	list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) {
475 		if (it++ != symnum)
476 			continue;
477 
478 		bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
479 		bpf_get_prog_name(aux->prog, sym);
480 
481 		*value = symbol_start;
482 		*type  = BPF_SYM_ELF_TYPE;
483 
484 		ret = 0;
485 		break;
486 	}
487 	rcu_read_unlock();
488 
489 	return ret;
490 }
491 
492 struct bpf_binary_header *
493 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
494 		     unsigned int alignment,
495 		     bpf_jit_fill_hole_t bpf_fill_ill_insns)
496 {
497 	struct bpf_binary_header *hdr;
498 	unsigned int size, hole, start;
499 
500 	/* Most of BPF filters are really small, but if some of them
501 	 * fill a page, allow at least 128 extra bytes to insert a
502 	 * random section of illegal instructions.
503 	 */
504 	size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
505 	hdr = module_alloc(size);
506 	if (hdr == NULL)
507 		return NULL;
508 
509 	/* Fill space with illegal/arch-dep instructions. */
510 	bpf_fill_ill_insns(hdr, size);
511 
512 	hdr->pages = size / PAGE_SIZE;
513 	hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
514 		     PAGE_SIZE - sizeof(*hdr));
515 	start = (get_random_int() % hole) & ~(alignment - 1);
516 
517 	/* Leave a random number of instructions before BPF code. */
518 	*image_ptr = &hdr->image[start];
519 
520 	return hdr;
521 }
522 
523 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
524 {
525 	module_memfree(hdr);
526 }
527 
528 /* This symbol is only overridden by archs that have different
529  * requirements than the usual eBPF JITs, f.e. when they only
530  * implement cBPF JIT, do not set images read-only, etc.
531  */
532 void __weak bpf_jit_free(struct bpf_prog *fp)
533 {
534 	if (fp->jited) {
535 		struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
536 
537 		bpf_jit_binary_unlock_ro(hdr);
538 		bpf_jit_binary_free(hdr);
539 
540 		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
541 	}
542 
543 	bpf_prog_unlock_free(fp);
544 }
545 
546 int bpf_jit_harden __read_mostly;
547 
548 static int bpf_jit_blind_insn(const struct bpf_insn *from,
549 			      const struct bpf_insn *aux,
550 			      struct bpf_insn *to_buff)
551 {
552 	struct bpf_insn *to = to_buff;
553 	u32 imm_rnd = get_random_int();
554 	s16 off;
555 
556 	BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
557 	BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
558 
559 	if (from->imm == 0 &&
560 	    (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
561 	     from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
562 		*to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
563 		goto out;
564 	}
565 
566 	switch (from->code) {
567 	case BPF_ALU | BPF_ADD | BPF_K:
568 	case BPF_ALU | BPF_SUB | BPF_K:
569 	case BPF_ALU | BPF_AND | BPF_K:
570 	case BPF_ALU | BPF_OR  | BPF_K:
571 	case BPF_ALU | BPF_XOR | BPF_K:
572 	case BPF_ALU | BPF_MUL | BPF_K:
573 	case BPF_ALU | BPF_MOV | BPF_K:
574 	case BPF_ALU | BPF_DIV | BPF_K:
575 	case BPF_ALU | BPF_MOD | BPF_K:
576 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
577 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
578 		*to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
579 		break;
580 
581 	case BPF_ALU64 | BPF_ADD | BPF_K:
582 	case BPF_ALU64 | BPF_SUB | BPF_K:
583 	case BPF_ALU64 | BPF_AND | BPF_K:
584 	case BPF_ALU64 | BPF_OR  | BPF_K:
585 	case BPF_ALU64 | BPF_XOR | BPF_K:
586 	case BPF_ALU64 | BPF_MUL | BPF_K:
587 	case BPF_ALU64 | BPF_MOV | BPF_K:
588 	case BPF_ALU64 | BPF_DIV | BPF_K:
589 	case BPF_ALU64 | BPF_MOD | BPF_K:
590 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
591 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
592 		*to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
593 		break;
594 
595 	case BPF_JMP | BPF_JEQ  | BPF_K:
596 	case BPF_JMP | BPF_JNE  | BPF_K:
597 	case BPF_JMP | BPF_JGT  | BPF_K:
598 	case BPF_JMP | BPF_JGE  | BPF_K:
599 	case BPF_JMP | BPF_JSGT | BPF_K:
600 	case BPF_JMP | BPF_JSGE | BPF_K:
601 	case BPF_JMP | BPF_JSET | BPF_K:
602 		/* Accommodate for extra offset in case of a backjump. */
603 		off = from->off;
604 		if (off < 0)
605 			off -= 2;
606 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
607 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
608 		*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
609 		break;
610 
611 	case BPF_LD | BPF_ABS | BPF_W:
612 	case BPF_LD | BPF_ABS | BPF_H:
613 	case BPF_LD | BPF_ABS | BPF_B:
614 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
615 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
616 		*to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0);
617 		break;
618 
619 	case BPF_LD | BPF_IND | BPF_W:
620 	case BPF_LD | BPF_IND | BPF_H:
621 	case BPF_LD | BPF_IND | BPF_B:
622 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
623 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
624 		*to++ = BPF_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg);
625 		*to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0);
626 		break;
627 
628 	case BPF_LD | BPF_IMM | BPF_DW:
629 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
630 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
631 		*to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
632 		*to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
633 		break;
634 	case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
635 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
636 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
637 		*to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
638 		break;
639 
640 	case BPF_ST | BPF_MEM | BPF_DW:
641 	case BPF_ST | BPF_MEM | BPF_W:
642 	case BPF_ST | BPF_MEM | BPF_H:
643 	case BPF_ST | BPF_MEM | BPF_B:
644 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
645 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
646 		*to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
647 		break;
648 	}
649 out:
650 	return to - to_buff;
651 }
652 
653 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
654 					      gfp_t gfp_extra_flags)
655 {
656 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
657 	struct bpf_prog *fp;
658 
659 	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL);
660 	if (fp != NULL) {
661 		kmemcheck_annotate_bitfield(fp, meta);
662 
663 		/* aux->prog still points to the fp_other one, so
664 		 * when promoting the clone to the real program,
665 		 * this still needs to be adapted.
666 		 */
667 		memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
668 	}
669 
670 	return fp;
671 }
672 
673 static void bpf_prog_clone_free(struct bpf_prog *fp)
674 {
675 	/* aux was stolen by the other clone, so we cannot free
676 	 * it from this path! It will be freed eventually by the
677 	 * other program on release.
678 	 *
679 	 * At this point, we don't need a deferred release since
680 	 * clone is guaranteed to not be locked.
681 	 */
682 	fp->aux = NULL;
683 	__bpf_prog_free(fp);
684 }
685 
686 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
687 {
688 	/* We have to repoint aux->prog to self, as we don't
689 	 * know whether fp here is the clone or the original.
690 	 */
691 	fp->aux->prog = fp;
692 	bpf_prog_clone_free(fp_other);
693 }
694 
695 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
696 {
697 	struct bpf_insn insn_buff[16], aux[2];
698 	struct bpf_prog *clone, *tmp;
699 	int insn_delta, insn_cnt;
700 	struct bpf_insn *insn;
701 	int i, rewritten;
702 
703 	if (!bpf_jit_blinding_enabled())
704 		return prog;
705 
706 	clone = bpf_prog_clone_create(prog, GFP_USER);
707 	if (!clone)
708 		return ERR_PTR(-ENOMEM);
709 
710 	insn_cnt = clone->len;
711 	insn = clone->insnsi;
712 
713 	for (i = 0; i < insn_cnt; i++, insn++) {
714 		/* We temporarily need to hold the original ld64 insn
715 		 * so that we can still access the first part in the
716 		 * second blinding run.
717 		 */
718 		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
719 		    insn[1].code == 0)
720 			memcpy(aux, insn, sizeof(aux));
721 
722 		rewritten = bpf_jit_blind_insn(insn, aux, insn_buff);
723 		if (!rewritten)
724 			continue;
725 
726 		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
727 		if (!tmp) {
728 			/* Patching may have repointed aux->prog during
729 			 * realloc from the original one, so we need to
730 			 * fix it up here on error.
731 			 */
732 			bpf_jit_prog_release_other(prog, clone);
733 			return ERR_PTR(-ENOMEM);
734 		}
735 
736 		clone = tmp;
737 		insn_delta = rewritten - 1;
738 
739 		/* Walk new program and skip insns we just inserted. */
740 		insn = clone->insnsi + i + insn_delta;
741 		insn_cnt += insn_delta;
742 		i        += insn_delta;
743 	}
744 
745 	return clone;
746 }
747 #endif /* CONFIG_BPF_JIT */
748 
749 /* Base function for offset calculation. Needs to go into .text section,
750  * therefore keeping it non-static as well; will also be used by JITs
751  * anyway later on, so do not let the compiler omit it.
752  */
753 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
754 {
755 	return 0;
756 }
757 EXPORT_SYMBOL_GPL(__bpf_call_base);
758 
759 /**
760  *	__bpf_prog_run - run eBPF program on a given context
761  *	@ctx: is the data we are operating on
762  *	@insn: is the array of eBPF instructions
763  *
764  * Decode and execute eBPF instructions.
765  */
766 static unsigned int ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn,
767 				    u64 *stack)
768 {
769 	u64 tmp;
770 	static const void *jumptable[256] = {
771 		[0 ... 255] = &&default_label,
772 		/* Now overwrite non-defaults ... */
773 		/* 32 bit ALU operations */
774 		[BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X,
775 		[BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K,
776 		[BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X,
777 		[BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K,
778 		[BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X,
779 		[BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K,
780 		[BPF_ALU | BPF_OR | BPF_X]  = &&ALU_OR_X,
781 		[BPF_ALU | BPF_OR | BPF_K]  = &&ALU_OR_K,
782 		[BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X,
783 		[BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K,
784 		[BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X,
785 		[BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K,
786 		[BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X,
787 		[BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K,
788 		[BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X,
789 		[BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K,
790 		[BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X,
791 		[BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K,
792 		[BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X,
793 		[BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K,
794 		[BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X,
795 		[BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K,
796 		[BPF_ALU | BPF_NEG] = &&ALU_NEG,
797 		[BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE,
798 		[BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE,
799 		/* 64 bit ALU operations */
800 		[BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X,
801 		[BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K,
802 		[BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X,
803 		[BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K,
804 		[BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X,
805 		[BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K,
806 		[BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X,
807 		[BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K,
808 		[BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X,
809 		[BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K,
810 		[BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X,
811 		[BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K,
812 		[BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X,
813 		[BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K,
814 		[BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X,
815 		[BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K,
816 		[BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X,
817 		[BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K,
818 		[BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X,
819 		[BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K,
820 		[BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X,
821 		[BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K,
822 		[BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X,
823 		[BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K,
824 		[BPF_ALU64 | BPF_NEG] = &&ALU64_NEG,
825 		/* Call instruction */
826 		[BPF_JMP | BPF_CALL] = &&JMP_CALL,
827 		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
828 		/* Jumps */
829 		[BPF_JMP | BPF_JA] = &&JMP_JA,
830 		[BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X,
831 		[BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K,
832 		[BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X,
833 		[BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K,
834 		[BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X,
835 		[BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K,
836 		[BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X,
837 		[BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K,
838 		[BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X,
839 		[BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K,
840 		[BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X,
841 		[BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K,
842 		[BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X,
843 		[BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K,
844 		/* Program return */
845 		[BPF_JMP | BPF_EXIT] = &&JMP_EXIT,
846 		/* Store instructions */
847 		[BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B,
848 		[BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H,
849 		[BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W,
850 		[BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW,
851 		[BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W,
852 		[BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW,
853 		[BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B,
854 		[BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H,
855 		[BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W,
856 		[BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW,
857 		/* Load instructions */
858 		[BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B,
859 		[BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H,
860 		[BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W,
861 		[BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW,
862 		[BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W,
863 		[BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H,
864 		[BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B,
865 		[BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W,
866 		[BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H,
867 		[BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B,
868 		[BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW,
869 	};
870 	u32 tail_call_cnt = 0;
871 	void *ptr;
872 	int off;
873 
874 #define CONT	 ({ insn++; goto select_insn; })
875 #define CONT_JMP ({ insn++; goto select_insn; })
876 
877 select_insn:
878 	goto *jumptable[insn->code];
879 
880 	/* ALU */
881 #define ALU(OPCODE, OP)			\
882 	ALU64_##OPCODE##_X:		\
883 		DST = DST OP SRC;	\
884 		CONT;			\
885 	ALU_##OPCODE##_X:		\
886 		DST = (u32) DST OP (u32) SRC;	\
887 		CONT;			\
888 	ALU64_##OPCODE##_K:		\
889 		DST = DST OP IMM;		\
890 		CONT;			\
891 	ALU_##OPCODE##_K:		\
892 		DST = (u32) DST OP (u32) IMM;	\
893 		CONT;
894 
895 	ALU(ADD,  +)
896 	ALU(SUB,  -)
897 	ALU(AND,  &)
898 	ALU(OR,   |)
899 	ALU(LSH, <<)
900 	ALU(RSH, >>)
901 	ALU(XOR,  ^)
902 	ALU(MUL,  *)
903 #undef ALU
904 	ALU_NEG:
905 		DST = (u32) -DST;
906 		CONT;
907 	ALU64_NEG:
908 		DST = -DST;
909 		CONT;
910 	ALU_MOV_X:
911 		DST = (u32) SRC;
912 		CONT;
913 	ALU_MOV_K:
914 		DST = (u32) IMM;
915 		CONT;
916 	ALU64_MOV_X:
917 		DST = SRC;
918 		CONT;
919 	ALU64_MOV_K:
920 		DST = IMM;
921 		CONT;
922 	LD_IMM_DW:
923 		DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
924 		insn++;
925 		CONT;
926 	ALU64_ARSH_X:
927 		(*(s64 *) &DST) >>= SRC;
928 		CONT;
929 	ALU64_ARSH_K:
930 		(*(s64 *) &DST) >>= IMM;
931 		CONT;
932 	ALU64_MOD_X:
933 		if (unlikely(SRC == 0))
934 			return 0;
935 		div64_u64_rem(DST, SRC, &tmp);
936 		DST = tmp;
937 		CONT;
938 	ALU_MOD_X:
939 		if (unlikely(SRC == 0))
940 			return 0;
941 		tmp = (u32) DST;
942 		DST = do_div(tmp, (u32) SRC);
943 		CONT;
944 	ALU64_MOD_K:
945 		div64_u64_rem(DST, IMM, &tmp);
946 		DST = tmp;
947 		CONT;
948 	ALU_MOD_K:
949 		tmp = (u32) DST;
950 		DST = do_div(tmp, (u32) IMM);
951 		CONT;
952 	ALU64_DIV_X:
953 		if (unlikely(SRC == 0))
954 			return 0;
955 		DST = div64_u64(DST, SRC);
956 		CONT;
957 	ALU_DIV_X:
958 		if (unlikely(SRC == 0))
959 			return 0;
960 		tmp = (u32) DST;
961 		do_div(tmp, (u32) SRC);
962 		DST = (u32) tmp;
963 		CONT;
964 	ALU64_DIV_K:
965 		DST = div64_u64(DST, IMM);
966 		CONT;
967 	ALU_DIV_K:
968 		tmp = (u32) DST;
969 		do_div(tmp, (u32) IMM);
970 		DST = (u32) tmp;
971 		CONT;
972 	ALU_END_TO_BE:
973 		switch (IMM) {
974 		case 16:
975 			DST = (__force u16) cpu_to_be16(DST);
976 			break;
977 		case 32:
978 			DST = (__force u32) cpu_to_be32(DST);
979 			break;
980 		case 64:
981 			DST = (__force u64) cpu_to_be64(DST);
982 			break;
983 		}
984 		CONT;
985 	ALU_END_TO_LE:
986 		switch (IMM) {
987 		case 16:
988 			DST = (__force u16) cpu_to_le16(DST);
989 			break;
990 		case 32:
991 			DST = (__force u32) cpu_to_le32(DST);
992 			break;
993 		case 64:
994 			DST = (__force u64) cpu_to_le64(DST);
995 			break;
996 		}
997 		CONT;
998 
999 	/* CALL */
1000 	JMP_CALL:
1001 		/* Function call scratches BPF_R1-BPF_R5 registers,
1002 		 * preserves BPF_R6-BPF_R9, and stores return value
1003 		 * into BPF_R0.
1004 		 */
1005 		BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1006 						       BPF_R4, BPF_R5);
1007 		CONT;
1008 
1009 	JMP_TAIL_CALL: {
1010 		struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1011 		struct bpf_array *array = container_of(map, struct bpf_array, map);
1012 		struct bpf_prog *prog;
1013 		u64 index = BPF_R3;
1014 
1015 		if (unlikely(index >= array->map.max_entries))
1016 			goto out;
1017 		if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT))
1018 			goto out;
1019 
1020 		tail_call_cnt++;
1021 
1022 		prog = READ_ONCE(array->ptrs[index]);
1023 		if (!prog)
1024 			goto out;
1025 
1026 		/* ARG1 at this point is guaranteed to point to CTX from
1027 		 * the verifier side due to the fact that the tail call is
1028 		 * handeled like a helper, that is, bpf_tail_call_proto,
1029 		 * where arg1_type is ARG_PTR_TO_CTX.
1030 		 */
1031 		insn = prog->insnsi;
1032 		goto select_insn;
1033 out:
1034 		CONT;
1035 	}
1036 	/* JMP */
1037 	JMP_JA:
1038 		insn += insn->off;
1039 		CONT;
1040 	JMP_JEQ_X:
1041 		if (DST == SRC) {
1042 			insn += insn->off;
1043 			CONT_JMP;
1044 		}
1045 		CONT;
1046 	JMP_JEQ_K:
1047 		if (DST == IMM) {
1048 			insn += insn->off;
1049 			CONT_JMP;
1050 		}
1051 		CONT;
1052 	JMP_JNE_X:
1053 		if (DST != SRC) {
1054 			insn += insn->off;
1055 			CONT_JMP;
1056 		}
1057 		CONT;
1058 	JMP_JNE_K:
1059 		if (DST != IMM) {
1060 			insn += insn->off;
1061 			CONT_JMP;
1062 		}
1063 		CONT;
1064 	JMP_JGT_X:
1065 		if (DST > SRC) {
1066 			insn += insn->off;
1067 			CONT_JMP;
1068 		}
1069 		CONT;
1070 	JMP_JGT_K:
1071 		if (DST > IMM) {
1072 			insn += insn->off;
1073 			CONT_JMP;
1074 		}
1075 		CONT;
1076 	JMP_JGE_X:
1077 		if (DST >= SRC) {
1078 			insn += insn->off;
1079 			CONT_JMP;
1080 		}
1081 		CONT;
1082 	JMP_JGE_K:
1083 		if (DST >= IMM) {
1084 			insn += insn->off;
1085 			CONT_JMP;
1086 		}
1087 		CONT;
1088 	JMP_JSGT_X:
1089 		if (((s64) DST) > ((s64) SRC)) {
1090 			insn += insn->off;
1091 			CONT_JMP;
1092 		}
1093 		CONT;
1094 	JMP_JSGT_K:
1095 		if (((s64) DST) > ((s64) IMM)) {
1096 			insn += insn->off;
1097 			CONT_JMP;
1098 		}
1099 		CONT;
1100 	JMP_JSGE_X:
1101 		if (((s64) DST) >= ((s64) SRC)) {
1102 			insn += insn->off;
1103 			CONT_JMP;
1104 		}
1105 		CONT;
1106 	JMP_JSGE_K:
1107 		if (((s64) DST) >= ((s64) IMM)) {
1108 			insn += insn->off;
1109 			CONT_JMP;
1110 		}
1111 		CONT;
1112 	JMP_JSET_X:
1113 		if (DST & SRC) {
1114 			insn += insn->off;
1115 			CONT_JMP;
1116 		}
1117 		CONT;
1118 	JMP_JSET_K:
1119 		if (DST & IMM) {
1120 			insn += insn->off;
1121 			CONT_JMP;
1122 		}
1123 		CONT;
1124 	JMP_EXIT:
1125 		return BPF_R0;
1126 
1127 	/* STX and ST and LDX*/
1128 #define LDST(SIZEOP, SIZE)						\
1129 	STX_MEM_##SIZEOP:						\
1130 		*(SIZE *)(unsigned long) (DST + insn->off) = SRC;	\
1131 		CONT;							\
1132 	ST_MEM_##SIZEOP:						\
1133 		*(SIZE *)(unsigned long) (DST + insn->off) = IMM;	\
1134 		CONT;							\
1135 	LDX_MEM_##SIZEOP:						\
1136 		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
1137 		CONT;
1138 
1139 	LDST(B,   u8)
1140 	LDST(H,  u16)
1141 	LDST(W,  u32)
1142 	LDST(DW, u64)
1143 #undef LDST
1144 	STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
1145 		atomic_add((u32) SRC, (atomic_t *)(unsigned long)
1146 			   (DST + insn->off));
1147 		CONT;
1148 	STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */
1149 		atomic64_add((u64) SRC, (atomic64_t *)(unsigned long)
1150 			     (DST + insn->off));
1151 		CONT;
1152 	LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */
1153 		off = IMM;
1154 load_word:
1155 		/* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are only
1156 		 * appearing in the programs where ctx == skb
1157 		 * (see may_access_skb() in the verifier). All programs
1158 		 * keep 'ctx' in regs[BPF_REG_CTX] == BPF_R6,
1159 		 * bpf_convert_filter() saves it in BPF_R6, internal BPF
1160 		 * verifier will check that BPF_R6 == ctx.
1161 		 *
1162 		 * BPF_ABS and BPF_IND are wrappers of function calls,
1163 		 * so they scratch BPF_R1-BPF_R5 registers, preserve
1164 		 * BPF_R6-BPF_R9, and store return value into BPF_R0.
1165 		 *
1166 		 * Implicit input:
1167 		 *   ctx == skb == BPF_R6 == CTX
1168 		 *
1169 		 * Explicit input:
1170 		 *   SRC == any register
1171 		 *   IMM == 32-bit immediate
1172 		 *
1173 		 * Output:
1174 		 *   BPF_R0 - 8/16/32-bit skb data converted to cpu endianness
1175 		 */
1176 
1177 		ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp);
1178 		if (likely(ptr != NULL)) {
1179 			BPF_R0 = get_unaligned_be32(ptr);
1180 			CONT;
1181 		}
1182 
1183 		return 0;
1184 	LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */
1185 		off = IMM;
1186 load_half:
1187 		ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp);
1188 		if (likely(ptr != NULL)) {
1189 			BPF_R0 = get_unaligned_be16(ptr);
1190 			CONT;
1191 		}
1192 
1193 		return 0;
1194 	LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */
1195 		off = IMM;
1196 load_byte:
1197 		ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp);
1198 		if (likely(ptr != NULL)) {
1199 			BPF_R0 = *(u8 *)ptr;
1200 			CONT;
1201 		}
1202 
1203 		return 0;
1204 	LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */
1205 		off = IMM + SRC;
1206 		goto load_word;
1207 	LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */
1208 		off = IMM + SRC;
1209 		goto load_half;
1210 	LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */
1211 		off = IMM + SRC;
1212 		goto load_byte;
1213 
1214 	default_label:
1215 		/* If we ever reach this, we have a bug somewhere. */
1216 		WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code);
1217 		return 0;
1218 }
1219 STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */
1220 
1221 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
1222 #define DEFINE_BPF_PROG_RUN(stack_size) \
1223 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
1224 { \
1225 	u64 stack[stack_size / sizeof(u64)]; \
1226 	u64 regs[MAX_BPF_REG]; \
1227 \
1228 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
1229 	ARG1 = (u64) (unsigned long) ctx; \
1230 	return ___bpf_prog_run(regs, insn, stack); \
1231 }
1232 
1233 #define EVAL1(FN, X) FN(X)
1234 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
1235 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
1236 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
1237 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
1238 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
1239 
1240 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
1241 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
1242 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
1243 
1244 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
1245 
1246 static unsigned int (*interpreters[])(const void *ctx,
1247 				      const struct bpf_insn *insn) = {
1248 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
1249 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
1250 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
1251 };
1252 
1253 bool bpf_prog_array_compatible(struct bpf_array *array,
1254 			       const struct bpf_prog *fp)
1255 {
1256 	if (!array->owner_prog_type) {
1257 		/* There's no owner yet where we could check for
1258 		 * compatibility.
1259 		 */
1260 		array->owner_prog_type = fp->type;
1261 		array->owner_jited = fp->jited;
1262 
1263 		return true;
1264 	}
1265 
1266 	return array->owner_prog_type == fp->type &&
1267 	       array->owner_jited == fp->jited;
1268 }
1269 
1270 static int bpf_check_tail_call(const struct bpf_prog *fp)
1271 {
1272 	struct bpf_prog_aux *aux = fp->aux;
1273 	int i;
1274 
1275 	for (i = 0; i < aux->used_map_cnt; i++) {
1276 		struct bpf_map *map = aux->used_maps[i];
1277 		struct bpf_array *array;
1278 
1279 		if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
1280 			continue;
1281 
1282 		array = container_of(map, struct bpf_array, map);
1283 		if (!bpf_prog_array_compatible(array, fp))
1284 			return -EINVAL;
1285 	}
1286 
1287 	return 0;
1288 }
1289 
1290 /**
1291  *	bpf_prog_select_runtime - select exec runtime for BPF program
1292  *	@fp: bpf_prog populated with internal BPF program
1293  *	@err: pointer to error variable
1294  *
1295  * Try to JIT eBPF program, if JIT is not available, use interpreter.
1296  * The BPF program will be executed via BPF_PROG_RUN() macro.
1297  */
1298 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
1299 {
1300 	u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
1301 
1302 	fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
1303 
1304 	/* eBPF JITs can rewrite the program in case constant
1305 	 * blinding is active. However, in case of error during
1306 	 * blinding, bpf_int_jit_compile() must always return a
1307 	 * valid program, which in this case would simply not
1308 	 * be JITed, but falls back to the interpreter.
1309 	 */
1310 	fp = bpf_int_jit_compile(fp);
1311 	bpf_prog_lock_ro(fp);
1312 
1313 	/* The tail call compatibility check can only be done at
1314 	 * this late stage as we need to determine, if we deal
1315 	 * with JITed or non JITed program concatenations and not
1316 	 * all eBPF JITs might immediately support all features.
1317 	 */
1318 	*err = bpf_check_tail_call(fp);
1319 
1320 	return fp;
1321 }
1322 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
1323 
1324 static void bpf_prog_free_deferred(struct work_struct *work)
1325 {
1326 	struct bpf_prog_aux *aux;
1327 
1328 	aux = container_of(work, struct bpf_prog_aux, work);
1329 	bpf_jit_free(aux->prog);
1330 }
1331 
1332 /* Free internal BPF program */
1333 void bpf_prog_free(struct bpf_prog *fp)
1334 {
1335 	struct bpf_prog_aux *aux = fp->aux;
1336 
1337 	INIT_WORK(&aux->work, bpf_prog_free_deferred);
1338 	schedule_work(&aux->work);
1339 }
1340 EXPORT_SYMBOL_GPL(bpf_prog_free);
1341 
1342 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
1343 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
1344 
1345 void bpf_user_rnd_init_once(void)
1346 {
1347 	prandom_init_once(&bpf_user_rnd_state);
1348 }
1349 
1350 BPF_CALL_0(bpf_user_rnd_u32)
1351 {
1352 	/* Should someone ever have the rather unwise idea to use some
1353 	 * of the registers passed into this function, then note that
1354 	 * this function is called from native eBPF and classic-to-eBPF
1355 	 * transformations. Register assignments from both sides are
1356 	 * different, f.e. classic always sets fn(ctx, A, X) here.
1357 	 */
1358 	struct rnd_state *state;
1359 	u32 res;
1360 
1361 	state = &get_cpu_var(bpf_user_rnd_state);
1362 	res = prandom_u32_state(state);
1363 	put_cpu_var(bpf_user_rnd_state);
1364 
1365 	return res;
1366 }
1367 
1368 /* Weak definitions of helper functions in case we don't have bpf syscall. */
1369 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
1370 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
1371 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
1372 
1373 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
1374 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
1375 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
1376 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
1377 
1378 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
1379 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
1380 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
1381 
1382 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
1383 {
1384 	return NULL;
1385 }
1386 
1387 u64 __weak
1388 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
1389 		 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
1390 {
1391 	return -ENOTSUPP;
1392 }
1393 
1394 /* Always built-in helper functions. */
1395 const struct bpf_func_proto bpf_tail_call_proto = {
1396 	.func		= NULL,
1397 	.gpl_only	= false,
1398 	.ret_type	= RET_VOID,
1399 	.arg1_type	= ARG_PTR_TO_CTX,
1400 	.arg2_type	= ARG_CONST_MAP_PTR,
1401 	.arg3_type	= ARG_ANYTHING,
1402 };
1403 
1404 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
1405  * It is encouraged to implement bpf_int_jit_compile() instead, so that
1406  * eBPF and implicitly also cBPF can get JITed!
1407  */
1408 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
1409 {
1410 	return prog;
1411 }
1412 
1413 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
1414  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
1415  */
1416 void __weak bpf_jit_compile(struct bpf_prog *prog)
1417 {
1418 }
1419 
1420 bool __weak bpf_helper_changes_pkt_data(void *func)
1421 {
1422 	return false;
1423 }
1424 
1425 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
1426  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
1427  */
1428 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
1429 			 int len)
1430 {
1431 	return -EFAULT;
1432 }
1433 
1434 /* All definitions of tracepoints related to BPF. */
1435 #define CREATE_TRACE_POINTS
1436 #include <linux/bpf_trace.h>
1437 
1438 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
1439 
1440 EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_get_type);
1441 EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_put_rcu);
1442