xref: /linux/kernel/bpf/core.c (revision 005c54278b3dd38f6045a2450a8c988cc7d3def2)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Linux Socket Filter - Kernel level socket filtering
4  *
5  * Based on the design of the Berkeley Packet Filter. The new
6  * internal format has been designed by PLUMgrid:
7  *
8  *	Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
9  *
10  * Authors:
11  *
12  *	Jay Schulist <jschlst@samba.org>
13  *	Alexei Starovoitov <ast@plumgrid.com>
14  *	Daniel Borkmann <dborkman@redhat.com>
15  *
16  * Andi Kleen - Fix a few bad bugs and races.
17  * Kris Katterjohn - Added many additional checks in bpf_check_classic()
18  */
19 
20 #include <uapi/linux/btf.h>
21 #include <linux/filter.h>
22 #include <linux/skbuff.h>
23 #include <linux/vmalloc.h>
24 #include <linux/random.h>
25 #include <linux/moduleloader.h>
26 #include <linux/bpf.h>
27 #include <linux/btf.h>
28 #include <linux/objtool.h>
29 #include <linux/rbtree_latch.h>
30 #include <linux/kallsyms.h>
31 #include <linux/rcupdate.h>
32 #include <linux/perf_event.h>
33 #include <linux/extable.h>
34 #include <linux/log2.h>
35 #include <linux/bpf_verifier.h>
36 #include <linux/nodemask.h>
37 #include <linux/bpf_mem_alloc.h>
38 
39 #include <asm/barrier.h>
40 #include <asm/unaligned.h>
41 
42 /* Registers */
43 #define BPF_R0	regs[BPF_REG_0]
44 #define BPF_R1	regs[BPF_REG_1]
45 #define BPF_R2	regs[BPF_REG_2]
46 #define BPF_R3	regs[BPF_REG_3]
47 #define BPF_R4	regs[BPF_REG_4]
48 #define BPF_R5	regs[BPF_REG_5]
49 #define BPF_R6	regs[BPF_REG_6]
50 #define BPF_R7	regs[BPF_REG_7]
51 #define BPF_R8	regs[BPF_REG_8]
52 #define BPF_R9	regs[BPF_REG_9]
53 #define BPF_R10	regs[BPF_REG_10]
54 
55 /* Named registers */
56 #define DST	regs[insn->dst_reg]
57 #define SRC	regs[insn->src_reg]
58 #define FP	regs[BPF_REG_FP]
59 #define AX	regs[BPF_REG_AX]
60 #define ARG1	regs[BPF_REG_ARG1]
61 #define CTX	regs[BPF_REG_CTX]
62 #define IMM	insn->imm
63 
64 struct bpf_mem_alloc bpf_global_ma;
65 bool bpf_global_ma_set;
66 
67 /* No hurry in this branch
68  *
69  * Exported for the bpf jit load helper.
70  */
71 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
72 {
73 	u8 *ptr = NULL;
74 
75 	if (k >= SKF_NET_OFF) {
76 		ptr = skb_network_header(skb) + k - SKF_NET_OFF;
77 	} else if (k >= SKF_LL_OFF) {
78 		if (unlikely(!skb_mac_header_was_set(skb)))
79 			return NULL;
80 		ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
81 	}
82 	if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
83 		return ptr;
84 
85 	return NULL;
86 }
87 
88 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
89 {
90 	gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
91 	struct bpf_prog_aux *aux;
92 	struct bpf_prog *fp;
93 
94 	size = round_up(size, PAGE_SIZE);
95 	fp = __vmalloc(size, gfp_flags);
96 	if (fp == NULL)
97 		return NULL;
98 
99 	aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT | gfp_extra_flags);
100 	if (aux == NULL) {
101 		vfree(fp);
102 		return NULL;
103 	}
104 	fp->active = alloc_percpu_gfp(int, GFP_KERNEL_ACCOUNT | gfp_extra_flags);
105 	if (!fp->active) {
106 		vfree(fp);
107 		kfree(aux);
108 		return NULL;
109 	}
110 
111 	fp->pages = size / PAGE_SIZE;
112 	fp->aux = aux;
113 	fp->aux->prog = fp;
114 	fp->jit_requested = ebpf_jit_enabled();
115 	fp->blinding_requested = bpf_jit_blinding_enabled(fp);
116 #ifdef CONFIG_CGROUP_BPF
117 	aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID;
118 #endif
119 
120 	INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
121 	mutex_init(&fp->aux->used_maps_mutex);
122 	mutex_init(&fp->aux->dst_mutex);
123 
124 	return fp;
125 }
126 
127 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
128 {
129 	gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
130 	struct bpf_prog *prog;
131 	int cpu;
132 
133 	prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
134 	if (!prog)
135 		return NULL;
136 
137 	prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
138 	if (!prog->stats) {
139 		free_percpu(prog->active);
140 		kfree(prog->aux);
141 		vfree(prog);
142 		return NULL;
143 	}
144 
145 	for_each_possible_cpu(cpu) {
146 		struct bpf_prog_stats *pstats;
147 
148 		pstats = per_cpu_ptr(prog->stats, cpu);
149 		u64_stats_init(&pstats->syncp);
150 	}
151 	return prog;
152 }
153 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
154 
155 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
156 {
157 	if (!prog->aux->nr_linfo || !prog->jit_requested)
158 		return 0;
159 
160 	prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
161 					  sizeof(*prog->aux->jited_linfo),
162 					  GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
163 	if (!prog->aux->jited_linfo)
164 		return -ENOMEM;
165 
166 	return 0;
167 }
168 
169 void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
170 {
171 	if (prog->aux->jited_linfo &&
172 	    (!prog->jited || !prog->aux->jited_linfo[0])) {
173 		kvfree(prog->aux->jited_linfo);
174 		prog->aux->jited_linfo = NULL;
175 	}
176 
177 	kfree(prog->aux->kfunc_tab);
178 	prog->aux->kfunc_tab = NULL;
179 }
180 
181 /* The jit engine is responsible to provide an array
182  * for insn_off to the jited_off mapping (insn_to_jit_off).
183  *
184  * The idx to this array is the insn_off.  Hence, the insn_off
185  * here is relative to the prog itself instead of the main prog.
186  * This array has one entry for each xlated bpf insn.
187  *
188  * jited_off is the byte off to the end of the jited insn.
189  *
190  * Hence, with
191  * insn_start:
192  *      The first bpf insn off of the prog.  The insn off
193  *      here is relative to the main prog.
194  *      e.g. if prog is a subprog, insn_start > 0
195  * linfo_idx:
196  *      The prog's idx to prog->aux->linfo and jited_linfo
197  *
198  * jited_linfo[linfo_idx] = prog->bpf_func
199  *
200  * For i > linfo_idx,
201  *
202  * jited_linfo[i] = prog->bpf_func +
203  *	insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
204  */
205 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
206 			       const u32 *insn_to_jit_off)
207 {
208 	u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
209 	const struct bpf_line_info *linfo;
210 	void **jited_linfo;
211 
212 	if (!prog->aux->jited_linfo)
213 		/* Userspace did not provide linfo */
214 		return;
215 
216 	linfo_idx = prog->aux->linfo_idx;
217 	linfo = &prog->aux->linfo[linfo_idx];
218 	insn_start = linfo[0].insn_off;
219 	insn_end = insn_start + prog->len;
220 
221 	jited_linfo = &prog->aux->jited_linfo[linfo_idx];
222 	jited_linfo[0] = prog->bpf_func;
223 
224 	nr_linfo = prog->aux->nr_linfo - linfo_idx;
225 
226 	for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
227 		/* The verifier ensures that linfo[i].insn_off is
228 		 * strictly increasing
229 		 */
230 		jited_linfo[i] = prog->bpf_func +
231 			insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
232 }
233 
234 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
235 				  gfp_t gfp_extra_flags)
236 {
237 	gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
238 	struct bpf_prog *fp;
239 	u32 pages;
240 
241 	size = round_up(size, PAGE_SIZE);
242 	pages = size / PAGE_SIZE;
243 	if (pages <= fp_old->pages)
244 		return fp_old;
245 
246 	fp = __vmalloc(size, gfp_flags);
247 	if (fp) {
248 		memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
249 		fp->pages = pages;
250 		fp->aux->prog = fp;
251 
252 		/* We keep fp->aux from fp_old around in the new
253 		 * reallocated structure.
254 		 */
255 		fp_old->aux = NULL;
256 		fp_old->stats = NULL;
257 		fp_old->active = NULL;
258 		__bpf_prog_free(fp_old);
259 	}
260 
261 	return fp;
262 }
263 
264 void __bpf_prog_free(struct bpf_prog *fp)
265 {
266 	if (fp->aux) {
267 		mutex_destroy(&fp->aux->used_maps_mutex);
268 		mutex_destroy(&fp->aux->dst_mutex);
269 		kfree(fp->aux->poke_tab);
270 		kfree(fp->aux);
271 	}
272 	free_percpu(fp->stats);
273 	free_percpu(fp->active);
274 	vfree(fp);
275 }
276 
277 int bpf_prog_calc_tag(struct bpf_prog *fp)
278 {
279 	const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
280 	u32 raw_size = bpf_prog_tag_scratch_size(fp);
281 	u32 digest[SHA1_DIGEST_WORDS];
282 	u32 ws[SHA1_WORKSPACE_WORDS];
283 	u32 i, bsize, psize, blocks;
284 	struct bpf_insn *dst;
285 	bool was_ld_map;
286 	u8 *raw, *todo;
287 	__be32 *result;
288 	__be64 *bits;
289 
290 	raw = vmalloc(raw_size);
291 	if (!raw)
292 		return -ENOMEM;
293 
294 	sha1_init(digest);
295 	memset(ws, 0, sizeof(ws));
296 
297 	/* We need to take out the map fd for the digest calculation
298 	 * since they are unstable from user space side.
299 	 */
300 	dst = (void *)raw;
301 	for (i = 0, was_ld_map = false; i < fp->len; i++) {
302 		dst[i] = fp->insnsi[i];
303 		if (!was_ld_map &&
304 		    dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
305 		    (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
306 		     dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
307 			was_ld_map = true;
308 			dst[i].imm = 0;
309 		} else if (was_ld_map &&
310 			   dst[i].code == 0 &&
311 			   dst[i].dst_reg == 0 &&
312 			   dst[i].src_reg == 0 &&
313 			   dst[i].off == 0) {
314 			was_ld_map = false;
315 			dst[i].imm = 0;
316 		} else {
317 			was_ld_map = false;
318 		}
319 	}
320 
321 	psize = bpf_prog_insn_size(fp);
322 	memset(&raw[psize], 0, raw_size - psize);
323 	raw[psize++] = 0x80;
324 
325 	bsize  = round_up(psize, SHA1_BLOCK_SIZE);
326 	blocks = bsize / SHA1_BLOCK_SIZE;
327 	todo   = raw;
328 	if (bsize - psize >= sizeof(__be64)) {
329 		bits = (__be64 *)(todo + bsize - sizeof(__be64));
330 	} else {
331 		bits = (__be64 *)(todo + bsize + bits_offset);
332 		blocks++;
333 	}
334 	*bits = cpu_to_be64((psize - 1) << 3);
335 
336 	while (blocks--) {
337 		sha1_transform(digest, todo, ws);
338 		todo += SHA1_BLOCK_SIZE;
339 	}
340 
341 	result = (__force __be32 *)digest;
342 	for (i = 0; i < SHA1_DIGEST_WORDS; i++)
343 		result[i] = cpu_to_be32(digest[i]);
344 	memcpy(fp->tag, result, sizeof(fp->tag));
345 
346 	vfree(raw);
347 	return 0;
348 }
349 
350 static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
351 				s32 end_new, s32 curr, const bool probe_pass)
352 {
353 	const s64 imm_min = S32_MIN, imm_max = S32_MAX;
354 	s32 delta = end_new - end_old;
355 	s64 imm = insn->imm;
356 
357 	if (curr < pos && curr + imm + 1 >= end_old)
358 		imm += delta;
359 	else if (curr >= end_new && curr + imm + 1 < end_new)
360 		imm -= delta;
361 	if (imm < imm_min || imm > imm_max)
362 		return -ERANGE;
363 	if (!probe_pass)
364 		insn->imm = imm;
365 	return 0;
366 }
367 
368 static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
369 				s32 end_new, s32 curr, const bool probe_pass)
370 {
371 	const s32 off_min = S16_MIN, off_max = S16_MAX;
372 	s32 delta = end_new - end_old;
373 	s32 off = insn->off;
374 
375 	if (curr < pos && curr + off + 1 >= end_old)
376 		off += delta;
377 	else if (curr >= end_new && curr + off + 1 < end_new)
378 		off -= delta;
379 	if (off < off_min || off > off_max)
380 		return -ERANGE;
381 	if (!probe_pass)
382 		insn->off = off;
383 	return 0;
384 }
385 
386 static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
387 			    s32 end_new, const bool probe_pass)
388 {
389 	u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
390 	struct bpf_insn *insn = prog->insnsi;
391 	int ret = 0;
392 
393 	for (i = 0; i < insn_cnt; i++, insn++) {
394 		u8 code;
395 
396 		/* In the probing pass we still operate on the original,
397 		 * unpatched image in order to check overflows before we
398 		 * do any other adjustments. Therefore skip the patchlet.
399 		 */
400 		if (probe_pass && i == pos) {
401 			i = end_new;
402 			insn = prog->insnsi + end_old;
403 		}
404 		if (bpf_pseudo_func(insn)) {
405 			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
406 						   end_new, i, probe_pass);
407 			if (ret)
408 				return ret;
409 			continue;
410 		}
411 		code = insn->code;
412 		if ((BPF_CLASS(code) != BPF_JMP &&
413 		     BPF_CLASS(code) != BPF_JMP32) ||
414 		    BPF_OP(code) == BPF_EXIT)
415 			continue;
416 		/* Adjust offset of jmps if we cross patch boundaries. */
417 		if (BPF_OP(code) == BPF_CALL) {
418 			if (insn->src_reg != BPF_PSEUDO_CALL)
419 				continue;
420 			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
421 						   end_new, i, probe_pass);
422 		} else {
423 			ret = bpf_adj_delta_to_off(insn, pos, end_old,
424 						   end_new, i, probe_pass);
425 		}
426 		if (ret)
427 			break;
428 	}
429 
430 	return ret;
431 }
432 
433 static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
434 {
435 	struct bpf_line_info *linfo;
436 	u32 i, nr_linfo;
437 
438 	nr_linfo = prog->aux->nr_linfo;
439 	if (!nr_linfo || !delta)
440 		return;
441 
442 	linfo = prog->aux->linfo;
443 
444 	for (i = 0; i < nr_linfo; i++)
445 		if (off < linfo[i].insn_off)
446 			break;
447 
448 	/* Push all off < linfo[i].insn_off by delta */
449 	for (; i < nr_linfo; i++)
450 		linfo[i].insn_off += delta;
451 }
452 
453 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
454 				       const struct bpf_insn *patch, u32 len)
455 {
456 	u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
457 	const u32 cnt_max = S16_MAX;
458 	struct bpf_prog *prog_adj;
459 	int err;
460 
461 	/* Since our patchlet doesn't expand the image, we're done. */
462 	if (insn_delta == 0) {
463 		memcpy(prog->insnsi + off, patch, sizeof(*patch));
464 		return prog;
465 	}
466 
467 	insn_adj_cnt = prog->len + insn_delta;
468 
469 	/* Reject anything that would potentially let the insn->off
470 	 * target overflow when we have excessive program expansions.
471 	 * We need to probe here before we do any reallocation where
472 	 * we afterwards may not fail anymore.
473 	 */
474 	if (insn_adj_cnt > cnt_max &&
475 	    (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
476 		return ERR_PTR(err);
477 
478 	/* Several new instructions need to be inserted. Make room
479 	 * for them. Likely, there's no need for a new allocation as
480 	 * last page could have large enough tailroom.
481 	 */
482 	prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
483 				    GFP_USER);
484 	if (!prog_adj)
485 		return ERR_PTR(-ENOMEM);
486 
487 	prog_adj->len = insn_adj_cnt;
488 
489 	/* Patching happens in 3 steps:
490 	 *
491 	 * 1) Move over tail of insnsi from next instruction onwards,
492 	 *    so we can patch the single target insn with one or more
493 	 *    new ones (patching is always from 1 to n insns, n > 0).
494 	 * 2) Inject new instructions at the target location.
495 	 * 3) Adjust branch offsets if necessary.
496 	 */
497 	insn_rest = insn_adj_cnt - off - len;
498 
499 	memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
500 		sizeof(*patch) * insn_rest);
501 	memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
502 
503 	/* We are guaranteed to not fail at this point, otherwise
504 	 * the ship has sailed to reverse to the original state. An
505 	 * overflow cannot happen at this point.
506 	 */
507 	BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
508 
509 	bpf_adj_linfo(prog_adj, off, insn_delta);
510 
511 	return prog_adj;
512 }
513 
514 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
515 {
516 	/* Branch offsets can't overflow when program is shrinking, no need
517 	 * to call bpf_adj_branches(..., true) here
518 	 */
519 	memmove(prog->insnsi + off, prog->insnsi + off + cnt,
520 		sizeof(struct bpf_insn) * (prog->len - off - cnt));
521 	prog->len -= cnt;
522 
523 	return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
524 }
525 
526 static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
527 {
528 	int i;
529 
530 	for (i = 0; i < fp->aux->func_cnt; i++)
531 		bpf_prog_kallsyms_del(fp->aux->func[i]);
532 }
533 
534 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
535 {
536 	bpf_prog_kallsyms_del_subprogs(fp);
537 	bpf_prog_kallsyms_del(fp);
538 }
539 
540 #ifdef CONFIG_BPF_JIT
541 /* All BPF JIT sysctl knobs here. */
542 int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
543 int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
544 int bpf_jit_harden   __read_mostly;
545 long bpf_jit_limit   __read_mostly;
546 long bpf_jit_limit_max __read_mostly;
547 
548 static void
549 bpf_prog_ksym_set_addr(struct bpf_prog *prog)
550 {
551 	WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
552 
553 	prog->aux->ksym.start = (unsigned long) prog->bpf_func;
554 	prog->aux->ksym.end   = prog->aux->ksym.start + prog->jited_len;
555 }
556 
557 static void
558 bpf_prog_ksym_set_name(struct bpf_prog *prog)
559 {
560 	char *sym = prog->aux->ksym.name;
561 	const char *end = sym + KSYM_NAME_LEN;
562 	const struct btf_type *type;
563 	const char *func_name;
564 
565 	BUILD_BUG_ON(sizeof("bpf_prog_") +
566 		     sizeof(prog->tag) * 2 +
567 		     /* name has been null terminated.
568 		      * We should need +1 for the '_' preceding
569 		      * the name.  However, the null character
570 		      * is double counted between the name and the
571 		      * sizeof("bpf_prog_") above, so we omit
572 		      * the +1 here.
573 		      */
574 		     sizeof(prog->aux->name) > KSYM_NAME_LEN);
575 
576 	sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
577 	sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
578 
579 	/* prog->aux->name will be ignored if full btf name is available */
580 	if (prog->aux->func_info_cnt) {
581 		type = btf_type_by_id(prog->aux->btf,
582 				      prog->aux->func_info[prog->aux->func_idx].type_id);
583 		func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
584 		snprintf(sym, (size_t)(end - sym), "_%s", func_name);
585 		return;
586 	}
587 
588 	if (prog->aux->name[0])
589 		snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
590 	else
591 		*sym = 0;
592 }
593 
594 static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
595 {
596 	return container_of(n, struct bpf_ksym, tnode)->start;
597 }
598 
599 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
600 					  struct latch_tree_node *b)
601 {
602 	return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
603 }
604 
605 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
606 {
607 	unsigned long val = (unsigned long)key;
608 	const struct bpf_ksym *ksym;
609 
610 	ksym = container_of(n, struct bpf_ksym, tnode);
611 
612 	if (val < ksym->start)
613 		return -1;
614 	if (val >= ksym->end)
615 		return  1;
616 
617 	return 0;
618 }
619 
620 static const struct latch_tree_ops bpf_tree_ops = {
621 	.less	= bpf_tree_less,
622 	.comp	= bpf_tree_comp,
623 };
624 
625 static DEFINE_SPINLOCK(bpf_lock);
626 static LIST_HEAD(bpf_kallsyms);
627 static struct latch_tree_root bpf_tree __cacheline_aligned;
628 
629 void bpf_ksym_add(struct bpf_ksym *ksym)
630 {
631 	spin_lock_bh(&bpf_lock);
632 	WARN_ON_ONCE(!list_empty(&ksym->lnode));
633 	list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
634 	latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
635 	spin_unlock_bh(&bpf_lock);
636 }
637 
638 static void __bpf_ksym_del(struct bpf_ksym *ksym)
639 {
640 	if (list_empty(&ksym->lnode))
641 		return;
642 
643 	latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
644 	list_del_rcu(&ksym->lnode);
645 }
646 
647 void bpf_ksym_del(struct bpf_ksym *ksym)
648 {
649 	spin_lock_bh(&bpf_lock);
650 	__bpf_ksym_del(ksym);
651 	spin_unlock_bh(&bpf_lock);
652 }
653 
654 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
655 {
656 	return fp->jited && !bpf_prog_was_classic(fp);
657 }
658 
659 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
660 {
661 	if (!bpf_prog_kallsyms_candidate(fp) ||
662 	    !bpf_capable())
663 		return;
664 
665 	bpf_prog_ksym_set_addr(fp);
666 	bpf_prog_ksym_set_name(fp);
667 	fp->aux->ksym.prog = true;
668 
669 	bpf_ksym_add(&fp->aux->ksym);
670 }
671 
672 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
673 {
674 	if (!bpf_prog_kallsyms_candidate(fp))
675 		return;
676 
677 	bpf_ksym_del(&fp->aux->ksym);
678 }
679 
680 static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
681 {
682 	struct latch_tree_node *n;
683 
684 	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
685 	return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
686 }
687 
688 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
689 				 unsigned long *off, char *sym)
690 {
691 	struct bpf_ksym *ksym;
692 	char *ret = NULL;
693 
694 	rcu_read_lock();
695 	ksym = bpf_ksym_find(addr);
696 	if (ksym) {
697 		unsigned long symbol_start = ksym->start;
698 		unsigned long symbol_end = ksym->end;
699 
700 		strncpy(sym, ksym->name, KSYM_NAME_LEN);
701 
702 		ret = sym;
703 		if (size)
704 			*size = symbol_end - symbol_start;
705 		if (off)
706 			*off  = addr - symbol_start;
707 	}
708 	rcu_read_unlock();
709 
710 	return ret;
711 }
712 
713 bool is_bpf_text_address(unsigned long addr)
714 {
715 	bool ret;
716 
717 	rcu_read_lock();
718 	ret = bpf_ksym_find(addr) != NULL;
719 	rcu_read_unlock();
720 
721 	return ret;
722 }
723 
724 static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
725 {
726 	struct bpf_ksym *ksym = bpf_ksym_find(addr);
727 
728 	return ksym && ksym->prog ?
729 	       container_of(ksym, struct bpf_prog_aux, ksym)->prog :
730 	       NULL;
731 }
732 
733 const struct exception_table_entry *search_bpf_extables(unsigned long addr)
734 {
735 	const struct exception_table_entry *e = NULL;
736 	struct bpf_prog *prog;
737 
738 	rcu_read_lock();
739 	prog = bpf_prog_ksym_find(addr);
740 	if (!prog)
741 		goto out;
742 	if (!prog->aux->num_exentries)
743 		goto out;
744 
745 	e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
746 out:
747 	rcu_read_unlock();
748 	return e;
749 }
750 
751 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
752 		    char *sym)
753 {
754 	struct bpf_ksym *ksym;
755 	unsigned int it = 0;
756 	int ret = -ERANGE;
757 
758 	if (!bpf_jit_kallsyms_enabled())
759 		return ret;
760 
761 	rcu_read_lock();
762 	list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
763 		if (it++ != symnum)
764 			continue;
765 
766 		strncpy(sym, ksym->name, KSYM_NAME_LEN);
767 
768 		*value = ksym->start;
769 		*type  = BPF_SYM_ELF_TYPE;
770 
771 		ret = 0;
772 		break;
773 	}
774 	rcu_read_unlock();
775 
776 	return ret;
777 }
778 
779 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
780 				struct bpf_jit_poke_descriptor *poke)
781 {
782 	struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
783 	static const u32 poke_tab_max = 1024;
784 	u32 slot = prog->aux->size_poke_tab;
785 	u32 size = slot + 1;
786 
787 	if (size > poke_tab_max)
788 		return -ENOSPC;
789 	if (poke->tailcall_target || poke->tailcall_target_stable ||
790 	    poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
791 		return -EINVAL;
792 
793 	switch (poke->reason) {
794 	case BPF_POKE_REASON_TAIL_CALL:
795 		if (!poke->tail_call.map)
796 			return -EINVAL;
797 		break;
798 	default:
799 		return -EINVAL;
800 	}
801 
802 	tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
803 	if (!tab)
804 		return -ENOMEM;
805 
806 	memcpy(&tab[slot], poke, sizeof(*poke));
807 	prog->aux->size_poke_tab = size;
808 	prog->aux->poke_tab = tab;
809 
810 	return slot;
811 }
812 
813 /*
814  * BPF program pack allocator.
815  *
816  * Most BPF programs are pretty small. Allocating a hole page for each
817  * program is sometime a waste. Many small bpf program also adds pressure
818  * to instruction TLB. To solve this issue, we introduce a BPF program pack
819  * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
820  * to host BPF programs.
821  */
822 #define BPF_PROG_CHUNK_SHIFT	6
823 #define BPF_PROG_CHUNK_SIZE	(1 << BPF_PROG_CHUNK_SHIFT)
824 #define BPF_PROG_CHUNK_MASK	(~(BPF_PROG_CHUNK_SIZE - 1))
825 
826 struct bpf_prog_pack {
827 	struct list_head list;
828 	void *ptr;
829 	unsigned long bitmap[];
830 };
831 
832 void bpf_jit_fill_hole_with_zero(void *area, unsigned int size)
833 {
834 	memset(area, 0, size);
835 }
836 
837 #define BPF_PROG_SIZE_TO_NBITS(size)	(round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
838 
839 static DEFINE_MUTEX(pack_mutex);
840 static LIST_HEAD(pack_list);
841 
842 /* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
843  * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
844  */
845 #ifdef PMD_SIZE
846 #define BPF_PROG_PACK_SIZE (PMD_SIZE * num_possible_nodes())
847 #else
848 #define BPF_PROG_PACK_SIZE PAGE_SIZE
849 #endif
850 
851 #define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
852 
853 static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
854 {
855 	struct bpf_prog_pack *pack;
856 
857 	pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)),
858 		       GFP_KERNEL);
859 	if (!pack)
860 		return NULL;
861 	pack->ptr = module_alloc(BPF_PROG_PACK_SIZE);
862 	if (!pack->ptr) {
863 		kfree(pack);
864 		return NULL;
865 	}
866 	bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
867 	bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
868 	list_add_tail(&pack->list, &pack_list);
869 
870 	set_vm_flush_reset_perms(pack->ptr);
871 	set_memory_ro((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE);
872 	set_memory_x((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE);
873 	return pack;
874 }
875 
876 void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
877 {
878 	unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
879 	struct bpf_prog_pack *pack;
880 	unsigned long pos;
881 	void *ptr = NULL;
882 
883 	mutex_lock(&pack_mutex);
884 	if (size > BPF_PROG_PACK_SIZE) {
885 		size = round_up(size, PAGE_SIZE);
886 		ptr = module_alloc(size);
887 		if (ptr) {
888 			bpf_fill_ill_insns(ptr, size);
889 			set_vm_flush_reset_perms(ptr);
890 			set_memory_ro((unsigned long)ptr, size / PAGE_SIZE);
891 			set_memory_x((unsigned long)ptr, size / PAGE_SIZE);
892 		}
893 		goto out;
894 	}
895 	list_for_each_entry(pack, &pack_list, list) {
896 		pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
897 						 nbits, 0);
898 		if (pos < BPF_PROG_CHUNK_COUNT)
899 			goto found_free_area;
900 	}
901 
902 	pack = alloc_new_pack(bpf_fill_ill_insns);
903 	if (!pack)
904 		goto out;
905 
906 	pos = 0;
907 
908 found_free_area:
909 	bitmap_set(pack->bitmap, pos, nbits);
910 	ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
911 
912 out:
913 	mutex_unlock(&pack_mutex);
914 	return ptr;
915 }
916 
917 void bpf_prog_pack_free(struct bpf_binary_header *hdr)
918 {
919 	struct bpf_prog_pack *pack = NULL, *tmp;
920 	unsigned int nbits;
921 	unsigned long pos;
922 
923 	mutex_lock(&pack_mutex);
924 	if (hdr->size > BPF_PROG_PACK_SIZE) {
925 		module_memfree(hdr);
926 		goto out;
927 	}
928 
929 	list_for_each_entry(tmp, &pack_list, list) {
930 		if ((void *)hdr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > (void *)hdr) {
931 			pack = tmp;
932 			break;
933 		}
934 	}
935 
936 	if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
937 		goto out;
938 
939 	nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size);
940 	pos = ((unsigned long)hdr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
941 
942 	WARN_ONCE(bpf_arch_text_invalidate(hdr, hdr->size),
943 		  "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
944 
945 	bitmap_clear(pack->bitmap, pos, nbits);
946 	if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
947 				       BPF_PROG_CHUNK_COUNT, 0) == 0) {
948 		list_del(&pack->list);
949 		module_memfree(pack->ptr);
950 		kfree(pack);
951 	}
952 out:
953 	mutex_unlock(&pack_mutex);
954 }
955 
956 static atomic_long_t bpf_jit_current;
957 
958 /* Can be overridden by an arch's JIT compiler if it has a custom,
959  * dedicated BPF backend memory area, or if neither of the two
960  * below apply.
961  */
962 u64 __weak bpf_jit_alloc_exec_limit(void)
963 {
964 #if defined(MODULES_VADDR)
965 	return MODULES_END - MODULES_VADDR;
966 #else
967 	return VMALLOC_END - VMALLOC_START;
968 #endif
969 }
970 
971 static int __init bpf_jit_charge_init(void)
972 {
973 	/* Only used as heuristic here to derive limit. */
974 	bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
975 	bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 2,
976 					    PAGE_SIZE), LONG_MAX);
977 	return 0;
978 }
979 pure_initcall(bpf_jit_charge_init);
980 
981 int bpf_jit_charge_modmem(u32 size)
982 {
983 	if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
984 		if (!bpf_capable()) {
985 			atomic_long_sub(size, &bpf_jit_current);
986 			return -EPERM;
987 		}
988 	}
989 
990 	return 0;
991 }
992 
993 void bpf_jit_uncharge_modmem(u32 size)
994 {
995 	atomic_long_sub(size, &bpf_jit_current);
996 }
997 
998 void *__weak bpf_jit_alloc_exec(unsigned long size)
999 {
1000 	return module_alloc(size);
1001 }
1002 
1003 void __weak bpf_jit_free_exec(void *addr)
1004 {
1005 	module_memfree(addr);
1006 }
1007 
1008 struct bpf_binary_header *
1009 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1010 		     unsigned int alignment,
1011 		     bpf_jit_fill_hole_t bpf_fill_ill_insns)
1012 {
1013 	struct bpf_binary_header *hdr;
1014 	u32 size, hole, start;
1015 
1016 	WARN_ON_ONCE(!is_power_of_2(alignment) ||
1017 		     alignment > BPF_IMAGE_ALIGNMENT);
1018 
1019 	/* Most of BPF filters are really small, but if some of them
1020 	 * fill a page, allow at least 128 extra bytes to insert a
1021 	 * random section of illegal instructions.
1022 	 */
1023 	size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
1024 
1025 	if (bpf_jit_charge_modmem(size))
1026 		return NULL;
1027 	hdr = bpf_jit_alloc_exec(size);
1028 	if (!hdr) {
1029 		bpf_jit_uncharge_modmem(size);
1030 		return NULL;
1031 	}
1032 
1033 	/* Fill space with illegal/arch-dep instructions. */
1034 	bpf_fill_ill_insns(hdr, size);
1035 
1036 	hdr->size = size;
1037 	hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
1038 		     PAGE_SIZE - sizeof(*hdr));
1039 	start = prandom_u32_max(hole) & ~(alignment - 1);
1040 
1041 	/* Leave a random number of instructions before BPF code. */
1042 	*image_ptr = &hdr->image[start];
1043 
1044 	return hdr;
1045 }
1046 
1047 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
1048 {
1049 	u32 size = hdr->size;
1050 
1051 	bpf_jit_free_exec(hdr);
1052 	bpf_jit_uncharge_modmem(size);
1053 }
1054 
1055 /* Allocate jit binary from bpf_prog_pack allocator.
1056  * Since the allocated memory is RO+X, the JIT engine cannot write directly
1057  * to the memory. To solve this problem, a RW buffer is also allocated at
1058  * as the same time. The JIT engine should calculate offsets based on the
1059  * RO memory address, but write JITed program to the RW buffer. Once the
1060  * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
1061  * the JITed program to the RO memory.
1062  */
1063 struct bpf_binary_header *
1064 bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
1065 			  unsigned int alignment,
1066 			  struct bpf_binary_header **rw_header,
1067 			  u8 **rw_image,
1068 			  bpf_jit_fill_hole_t bpf_fill_ill_insns)
1069 {
1070 	struct bpf_binary_header *ro_header;
1071 	u32 size, hole, start;
1072 
1073 	WARN_ON_ONCE(!is_power_of_2(alignment) ||
1074 		     alignment > BPF_IMAGE_ALIGNMENT);
1075 
1076 	/* add 16 bytes for a random section of illegal instructions */
1077 	size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
1078 
1079 	if (bpf_jit_charge_modmem(size))
1080 		return NULL;
1081 	ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns);
1082 	if (!ro_header) {
1083 		bpf_jit_uncharge_modmem(size);
1084 		return NULL;
1085 	}
1086 
1087 	*rw_header = kvmalloc(size, GFP_KERNEL);
1088 	if (!*rw_header) {
1089 		bpf_arch_text_copy(&ro_header->size, &size, sizeof(size));
1090 		bpf_prog_pack_free(ro_header);
1091 		bpf_jit_uncharge_modmem(size);
1092 		return NULL;
1093 	}
1094 
1095 	/* Fill space with illegal/arch-dep instructions. */
1096 	bpf_fill_ill_insns(*rw_header, size);
1097 	(*rw_header)->size = size;
1098 
1099 	hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
1100 		     BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
1101 	start = prandom_u32_max(hole) & ~(alignment - 1);
1102 
1103 	*image_ptr = &ro_header->image[start];
1104 	*rw_image = &(*rw_header)->image[start];
1105 
1106 	return ro_header;
1107 }
1108 
1109 /* Copy JITed text from rw_header to its final location, the ro_header. */
1110 int bpf_jit_binary_pack_finalize(struct bpf_prog *prog,
1111 				 struct bpf_binary_header *ro_header,
1112 				 struct bpf_binary_header *rw_header)
1113 {
1114 	void *ptr;
1115 
1116 	ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
1117 
1118 	kvfree(rw_header);
1119 
1120 	if (IS_ERR(ptr)) {
1121 		bpf_prog_pack_free(ro_header);
1122 		return PTR_ERR(ptr);
1123 	}
1124 	return 0;
1125 }
1126 
1127 /* bpf_jit_binary_pack_free is called in two different scenarios:
1128  *   1) when the program is freed after;
1129  *   2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
1130  * For case 2), we need to free both the RO memory and the RW buffer.
1131  *
1132  * bpf_jit_binary_pack_free requires proper ro_header->size. However,
1133  * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
1134  * must be set with either bpf_jit_binary_pack_finalize (normal path) or
1135  * bpf_arch_text_copy (when jit fails).
1136  */
1137 void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
1138 			      struct bpf_binary_header *rw_header)
1139 {
1140 	u32 size = ro_header->size;
1141 
1142 	bpf_prog_pack_free(ro_header);
1143 	kvfree(rw_header);
1144 	bpf_jit_uncharge_modmem(size);
1145 }
1146 
1147 struct bpf_binary_header *
1148 bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
1149 {
1150 	unsigned long real_start = (unsigned long)fp->bpf_func;
1151 	unsigned long addr;
1152 
1153 	addr = real_start & BPF_PROG_CHUNK_MASK;
1154 	return (void *)addr;
1155 }
1156 
1157 static inline struct bpf_binary_header *
1158 bpf_jit_binary_hdr(const struct bpf_prog *fp)
1159 {
1160 	unsigned long real_start = (unsigned long)fp->bpf_func;
1161 	unsigned long addr;
1162 
1163 	addr = real_start & PAGE_MASK;
1164 	return (void *)addr;
1165 }
1166 
1167 /* This symbol is only overridden by archs that have different
1168  * requirements than the usual eBPF JITs, f.e. when they only
1169  * implement cBPF JIT, do not set images read-only, etc.
1170  */
1171 void __weak bpf_jit_free(struct bpf_prog *fp)
1172 {
1173 	if (fp->jited) {
1174 		struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
1175 
1176 		bpf_jit_binary_free(hdr);
1177 		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
1178 	}
1179 
1180 	bpf_prog_unlock_free(fp);
1181 }
1182 
1183 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1184 			  const struct bpf_insn *insn, bool extra_pass,
1185 			  u64 *func_addr, bool *func_addr_fixed)
1186 {
1187 	s16 off = insn->off;
1188 	s32 imm = insn->imm;
1189 	u8 *addr;
1190 
1191 	*func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1192 	if (!*func_addr_fixed) {
1193 		/* Place-holder address till the last pass has collected
1194 		 * all addresses for JITed subprograms in which case we
1195 		 * can pick them up from prog->aux.
1196 		 */
1197 		if (!extra_pass)
1198 			addr = NULL;
1199 		else if (prog->aux->func &&
1200 			 off >= 0 && off < prog->aux->func_cnt)
1201 			addr = (u8 *)prog->aux->func[off]->bpf_func;
1202 		else
1203 			return -EINVAL;
1204 	} else {
1205 		/* Address of a BPF helper call. Since part of the core
1206 		 * kernel, it's always at a fixed location. __bpf_call_base
1207 		 * and the helper with imm relative to it are both in core
1208 		 * kernel.
1209 		 */
1210 		addr = (u8 *)__bpf_call_base + imm;
1211 	}
1212 
1213 	*func_addr = (unsigned long)addr;
1214 	return 0;
1215 }
1216 
1217 static int bpf_jit_blind_insn(const struct bpf_insn *from,
1218 			      const struct bpf_insn *aux,
1219 			      struct bpf_insn *to_buff,
1220 			      bool emit_zext)
1221 {
1222 	struct bpf_insn *to = to_buff;
1223 	u32 imm_rnd = get_random_u32();
1224 	s16 off;
1225 
1226 	BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
1227 	BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
1228 
1229 	/* Constraints on AX register:
1230 	 *
1231 	 * AX register is inaccessible from user space. It is mapped in
1232 	 * all JITs, and used here for constant blinding rewrites. It is
1233 	 * typically "stateless" meaning its contents are only valid within
1234 	 * the executed instruction, but not across several instructions.
1235 	 * There are a few exceptions however which are further detailed
1236 	 * below.
1237 	 *
1238 	 * Constant blinding is only used by JITs, not in the interpreter.
1239 	 * The interpreter uses AX in some occasions as a local temporary
1240 	 * register e.g. in DIV or MOD instructions.
1241 	 *
1242 	 * In restricted circumstances, the verifier can also use the AX
1243 	 * register for rewrites as long as they do not interfere with
1244 	 * the above cases!
1245 	 */
1246 	if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1247 		goto out;
1248 
1249 	if (from->imm == 0 &&
1250 	    (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
1251 	     from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1252 		*to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1253 		goto out;
1254 	}
1255 
1256 	switch (from->code) {
1257 	case BPF_ALU | BPF_ADD | BPF_K:
1258 	case BPF_ALU | BPF_SUB | BPF_K:
1259 	case BPF_ALU | BPF_AND | BPF_K:
1260 	case BPF_ALU | BPF_OR  | BPF_K:
1261 	case BPF_ALU | BPF_XOR | BPF_K:
1262 	case BPF_ALU | BPF_MUL | BPF_K:
1263 	case BPF_ALU | BPF_MOV | BPF_K:
1264 	case BPF_ALU | BPF_DIV | BPF_K:
1265 	case BPF_ALU | BPF_MOD | BPF_K:
1266 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1267 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1268 		*to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
1269 		break;
1270 
1271 	case BPF_ALU64 | BPF_ADD | BPF_K:
1272 	case BPF_ALU64 | BPF_SUB | BPF_K:
1273 	case BPF_ALU64 | BPF_AND | BPF_K:
1274 	case BPF_ALU64 | BPF_OR  | BPF_K:
1275 	case BPF_ALU64 | BPF_XOR | BPF_K:
1276 	case BPF_ALU64 | BPF_MUL | BPF_K:
1277 	case BPF_ALU64 | BPF_MOV | BPF_K:
1278 	case BPF_ALU64 | BPF_DIV | BPF_K:
1279 	case BPF_ALU64 | BPF_MOD | BPF_K:
1280 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1281 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1282 		*to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
1283 		break;
1284 
1285 	case BPF_JMP | BPF_JEQ  | BPF_K:
1286 	case BPF_JMP | BPF_JNE  | BPF_K:
1287 	case BPF_JMP | BPF_JGT  | BPF_K:
1288 	case BPF_JMP | BPF_JLT  | BPF_K:
1289 	case BPF_JMP | BPF_JGE  | BPF_K:
1290 	case BPF_JMP | BPF_JLE  | BPF_K:
1291 	case BPF_JMP | BPF_JSGT | BPF_K:
1292 	case BPF_JMP | BPF_JSLT | BPF_K:
1293 	case BPF_JMP | BPF_JSGE | BPF_K:
1294 	case BPF_JMP | BPF_JSLE | BPF_K:
1295 	case BPF_JMP | BPF_JSET | BPF_K:
1296 		/* Accommodate for extra offset in case of a backjump. */
1297 		off = from->off;
1298 		if (off < 0)
1299 			off -= 2;
1300 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1301 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1302 		*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1303 		break;
1304 
1305 	case BPF_JMP32 | BPF_JEQ  | BPF_K:
1306 	case BPF_JMP32 | BPF_JNE  | BPF_K:
1307 	case BPF_JMP32 | BPF_JGT  | BPF_K:
1308 	case BPF_JMP32 | BPF_JLT  | BPF_K:
1309 	case BPF_JMP32 | BPF_JGE  | BPF_K:
1310 	case BPF_JMP32 | BPF_JLE  | BPF_K:
1311 	case BPF_JMP32 | BPF_JSGT | BPF_K:
1312 	case BPF_JMP32 | BPF_JSLT | BPF_K:
1313 	case BPF_JMP32 | BPF_JSGE | BPF_K:
1314 	case BPF_JMP32 | BPF_JSLE | BPF_K:
1315 	case BPF_JMP32 | BPF_JSET | BPF_K:
1316 		/* Accommodate for extra offset in case of a backjump. */
1317 		off = from->off;
1318 		if (off < 0)
1319 			off -= 2;
1320 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1321 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1322 		*to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1323 				      off);
1324 		break;
1325 
1326 	case BPF_LD | BPF_IMM | BPF_DW:
1327 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1328 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1329 		*to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1330 		*to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1331 		break;
1332 	case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1333 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1334 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1335 		if (emit_zext)
1336 			*to++ = BPF_ZEXT_REG(BPF_REG_AX);
1337 		*to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
1338 		break;
1339 
1340 	case BPF_ST | BPF_MEM | BPF_DW:
1341 	case BPF_ST | BPF_MEM | BPF_W:
1342 	case BPF_ST | BPF_MEM | BPF_H:
1343 	case BPF_ST | BPF_MEM | BPF_B:
1344 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1345 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1346 		*to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1347 		break;
1348 	}
1349 out:
1350 	return to - to_buff;
1351 }
1352 
1353 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1354 					      gfp_t gfp_extra_flags)
1355 {
1356 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1357 	struct bpf_prog *fp;
1358 
1359 	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1360 	if (fp != NULL) {
1361 		/* aux->prog still points to the fp_other one, so
1362 		 * when promoting the clone to the real program,
1363 		 * this still needs to be adapted.
1364 		 */
1365 		memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1366 	}
1367 
1368 	return fp;
1369 }
1370 
1371 static void bpf_prog_clone_free(struct bpf_prog *fp)
1372 {
1373 	/* aux was stolen by the other clone, so we cannot free
1374 	 * it from this path! It will be freed eventually by the
1375 	 * other program on release.
1376 	 *
1377 	 * At this point, we don't need a deferred release since
1378 	 * clone is guaranteed to not be locked.
1379 	 */
1380 	fp->aux = NULL;
1381 	fp->stats = NULL;
1382 	fp->active = NULL;
1383 	__bpf_prog_free(fp);
1384 }
1385 
1386 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1387 {
1388 	/* We have to repoint aux->prog to self, as we don't
1389 	 * know whether fp here is the clone or the original.
1390 	 */
1391 	fp->aux->prog = fp;
1392 	bpf_prog_clone_free(fp_other);
1393 }
1394 
1395 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1396 {
1397 	struct bpf_insn insn_buff[16], aux[2];
1398 	struct bpf_prog *clone, *tmp;
1399 	int insn_delta, insn_cnt;
1400 	struct bpf_insn *insn;
1401 	int i, rewritten;
1402 
1403 	if (!prog->blinding_requested || prog->blinded)
1404 		return prog;
1405 
1406 	clone = bpf_prog_clone_create(prog, GFP_USER);
1407 	if (!clone)
1408 		return ERR_PTR(-ENOMEM);
1409 
1410 	insn_cnt = clone->len;
1411 	insn = clone->insnsi;
1412 
1413 	for (i = 0; i < insn_cnt; i++, insn++) {
1414 		if (bpf_pseudo_func(insn)) {
1415 			/* ld_imm64 with an address of bpf subprog is not
1416 			 * a user controlled constant. Don't randomize it,
1417 			 * since it will conflict with jit_subprogs() logic.
1418 			 */
1419 			insn++;
1420 			i++;
1421 			continue;
1422 		}
1423 
1424 		/* We temporarily need to hold the original ld64 insn
1425 		 * so that we can still access the first part in the
1426 		 * second blinding run.
1427 		 */
1428 		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1429 		    insn[1].code == 0)
1430 			memcpy(aux, insn, sizeof(aux));
1431 
1432 		rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1433 						clone->aux->verifier_zext);
1434 		if (!rewritten)
1435 			continue;
1436 
1437 		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1438 		if (IS_ERR(tmp)) {
1439 			/* Patching may have repointed aux->prog during
1440 			 * realloc from the original one, so we need to
1441 			 * fix it up here on error.
1442 			 */
1443 			bpf_jit_prog_release_other(prog, clone);
1444 			return tmp;
1445 		}
1446 
1447 		clone = tmp;
1448 		insn_delta = rewritten - 1;
1449 
1450 		/* Walk new program and skip insns we just inserted. */
1451 		insn = clone->insnsi + i + insn_delta;
1452 		insn_cnt += insn_delta;
1453 		i        += insn_delta;
1454 	}
1455 
1456 	clone->blinded = 1;
1457 	return clone;
1458 }
1459 #endif /* CONFIG_BPF_JIT */
1460 
1461 /* Base function for offset calculation. Needs to go into .text section,
1462  * therefore keeping it non-static as well; will also be used by JITs
1463  * anyway later on, so do not let the compiler omit it. This also needs
1464  * to go into kallsyms for correlation from e.g. bpftool, so naming
1465  * must not change.
1466  */
1467 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1468 {
1469 	return 0;
1470 }
1471 EXPORT_SYMBOL_GPL(__bpf_call_base);
1472 
1473 /* All UAPI available opcodes. */
1474 #define BPF_INSN_MAP(INSN_2, INSN_3)		\
1475 	/* 32 bit ALU operations. */		\
1476 	/*   Register based. */			\
1477 	INSN_3(ALU, ADD,  X),			\
1478 	INSN_3(ALU, SUB,  X),			\
1479 	INSN_3(ALU, AND,  X),			\
1480 	INSN_3(ALU, OR,   X),			\
1481 	INSN_3(ALU, LSH,  X),			\
1482 	INSN_3(ALU, RSH,  X),			\
1483 	INSN_3(ALU, XOR,  X),			\
1484 	INSN_3(ALU, MUL,  X),			\
1485 	INSN_3(ALU, MOV,  X),			\
1486 	INSN_3(ALU, ARSH, X),			\
1487 	INSN_3(ALU, DIV,  X),			\
1488 	INSN_3(ALU, MOD,  X),			\
1489 	INSN_2(ALU, NEG),			\
1490 	INSN_3(ALU, END, TO_BE),		\
1491 	INSN_3(ALU, END, TO_LE),		\
1492 	/*   Immediate based. */		\
1493 	INSN_3(ALU, ADD,  K),			\
1494 	INSN_3(ALU, SUB,  K),			\
1495 	INSN_3(ALU, AND,  K),			\
1496 	INSN_3(ALU, OR,   K),			\
1497 	INSN_3(ALU, LSH,  K),			\
1498 	INSN_3(ALU, RSH,  K),			\
1499 	INSN_3(ALU, XOR,  K),			\
1500 	INSN_3(ALU, MUL,  K),			\
1501 	INSN_3(ALU, MOV,  K),			\
1502 	INSN_3(ALU, ARSH, K),			\
1503 	INSN_3(ALU, DIV,  K),			\
1504 	INSN_3(ALU, MOD,  K),			\
1505 	/* 64 bit ALU operations. */		\
1506 	/*   Register based. */			\
1507 	INSN_3(ALU64, ADD,  X),			\
1508 	INSN_3(ALU64, SUB,  X),			\
1509 	INSN_3(ALU64, AND,  X),			\
1510 	INSN_3(ALU64, OR,   X),			\
1511 	INSN_3(ALU64, LSH,  X),			\
1512 	INSN_3(ALU64, RSH,  X),			\
1513 	INSN_3(ALU64, XOR,  X),			\
1514 	INSN_3(ALU64, MUL,  X),			\
1515 	INSN_3(ALU64, MOV,  X),			\
1516 	INSN_3(ALU64, ARSH, X),			\
1517 	INSN_3(ALU64, DIV,  X),			\
1518 	INSN_3(ALU64, MOD,  X),			\
1519 	INSN_2(ALU64, NEG),			\
1520 	/*   Immediate based. */		\
1521 	INSN_3(ALU64, ADD,  K),			\
1522 	INSN_3(ALU64, SUB,  K),			\
1523 	INSN_3(ALU64, AND,  K),			\
1524 	INSN_3(ALU64, OR,   K),			\
1525 	INSN_3(ALU64, LSH,  K),			\
1526 	INSN_3(ALU64, RSH,  K),			\
1527 	INSN_3(ALU64, XOR,  K),			\
1528 	INSN_3(ALU64, MUL,  K),			\
1529 	INSN_3(ALU64, MOV,  K),			\
1530 	INSN_3(ALU64, ARSH, K),			\
1531 	INSN_3(ALU64, DIV,  K),			\
1532 	INSN_3(ALU64, MOD,  K),			\
1533 	/* Call instruction. */			\
1534 	INSN_2(JMP, CALL),			\
1535 	/* Exit instruction. */			\
1536 	INSN_2(JMP, EXIT),			\
1537 	/* 32-bit Jump instructions. */		\
1538 	/*   Register based. */			\
1539 	INSN_3(JMP32, JEQ,  X),			\
1540 	INSN_3(JMP32, JNE,  X),			\
1541 	INSN_3(JMP32, JGT,  X),			\
1542 	INSN_3(JMP32, JLT,  X),			\
1543 	INSN_3(JMP32, JGE,  X),			\
1544 	INSN_3(JMP32, JLE,  X),			\
1545 	INSN_3(JMP32, JSGT, X),			\
1546 	INSN_3(JMP32, JSLT, X),			\
1547 	INSN_3(JMP32, JSGE, X),			\
1548 	INSN_3(JMP32, JSLE, X),			\
1549 	INSN_3(JMP32, JSET, X),			\
1550 	/*   Immediate based. */		\
1551 	INSN_3(JMP32, JEQ,  K),			\
1552 	INSN_3(JMP32, JNE,  K),			\
1553 	INSN_3(JMP32, JGT,  K),			\
1554 	INSN_3(JMP32, JLT,  K),			\
1555 	INSN_3(JMP32, JGE,  K),			\
1556 	INSN_3(JMP32, JLE,  K),			\
1557 	INSN_3(JMP32, JSGT, K),			\
1558 	INSN_3(JMP32, JSLT, K),			\
1559 	INSN_3(JMP32, JSGE, K),			\
1560 	INSN_3(JMP32, JSLE, K),			\
1561 	INSN_3(JMP32, JSET, K),			\
1562 	/* Jump instructions. */		\
1563 	/*   Register based. */			\
1564 	INSN_3(JMP, JEQ,  X),			\
1565 	INSN_3(JMP, JNE,  X),			\
1566 	INSN_3(JMP, JGT,  X),			\
1567 	INSN_3(JMP, JLT,  X),			\
1568 	INSN_3(JMP, JGE,  X),			\
1569 	INSN_3(JMP, JLE,  X),			\
1570 	INSN_3(JMP, JSGT, X),			\
1571 	INSN_3(JMP, JSLT, X),			\
1572 	INSN_3(JMP, JSGE, X),			\
1573 	INSN_3(JMP, JSLE, X),			\
1574 	INSN_3(JMP, JSET, X),			\
1575 	/*   Immediate based. */		\
1576 	INSN_3(JMP, JEQ,  K),			\
1577 	INSN_3(JMP, JNE,  K),			\
1578 	INSN_3(JMP, JGT,  K),			\
1579 	INSN_3(JMP, JLT,  K),			\
1580 	INSN_3(JMP, JGE,  K),			\
1581 	INSN_3(JMP, JLE,  K),			\
1582 	INSN_3(JMP, JSGT, K),			\
1583 	INSN_3(JMP, JSLT, K),			\
1584 	INSN_3(JMP, JSGE, K),			\
1585 	INSN_3(JMP, JSLE, K),			\
1586 	INSN_3(JMP, JSET, K),			\
1587 	INSN_2(JMP, JA),			\
1588 	/* Store instructions. */		\
1589 	/*   Register based. */			\
1590 	INSN_3(STX, MEM,  B),			\
1591 	INSN_3(STX, MEM,  H),			\
1592 	INSN_3(STX, MEM,  W),			\
1593 	INSN_3(STX, MEM,  DW),			\
1594 	INSN_3(STX, ATOMIC, W),			\
1595 	INSN_3(STX, ATOMIC, DW),		\
1596 	/*   Immediate based. */		\
1597 	INSN_3(ST, MEM, B),			\
1598 	INSN_3(ST, MEM, H),			\
1599 	INSN_3(ST, MEM, W),			\
1600 	INSN_3(ST, MEM, DW),			\
1601 	/* Load instructions. */		\
1602 	/*   Register based. */			\
1603 	INSN_3(LDX, MEM, B),			\
1604 	INSN_3(LDX, MEM, H),			\
1605 	INSN_3(LDX, MEM, W),			\
1606 	INSN_3(LDX, MEM, DW),			\
1607 	/*   Immediate based. */		\
1608 	INSN_3(LD, IMM, DW)
1609 
1610 bool bpf_opcode_in_insntable(u8 code)
1611 {
1612 #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
1613 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1614 	static const bool public_insntable[256] = {
1615 		[0 ... 255] = false,
1616 		/* Now overwrite non-defaults ... */
1617 		BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1618 		/* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1619 		[BPF_LD | BPF_ABS | BPF_B] = true,
1620 		[BPF_LD | BPF_ABS | BPF_H] = true,
1621 		[BPF_LD | BPF_ABS | BPF_W] = true,
1622 		[BPF_LD | BPF_IND | BPF_B] = true,
1623 		[BPF_LD | BPF_IND | BPF_H] = true,
1624 		[BPF_LD | BPF_IND | BPF_W] = true,
1625 	};
1626 #undef BPF_INSN_3_TBL
1627 #undef BPF_INSN_2_TBL
1628 	return public_insntable[code];
1629 }
1630 
1631 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1632 u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
1633 {
1634 	memset(dst, 0, size);
1635 	return -EFAULT;
1636 }
1637 
1638 /**
1639  *	___bpf_prog_run - run eBPF program on a given context
1640  *	@regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1641  *	@insn: is the array of eBPF instructions
1642  *
1643  * Decode and execute eBPF instructions.
1644  *
1645  * Return: whatever value is in %BPF_R0 at program exit
1646  */
1647 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1648 {
1649 #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
1650 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1651 	static const void * const jumptable[256] __annotate_jump_table = {
1652 		[0 ... 255] = &&default_label,
1653 		/* Now overwrite non-defaults ... */
1654 		BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1655 		/* Non-UAPI available opcodes. */
1656 		[BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1657 		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1658 		[BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
1659 		[BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1660 		[BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1661 		[BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1662 		[BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1663 	};
1664 #undef BPF_INSN_3_LBL
1665 #undef BPF_INSN_2_LBL
1666 	u32 tail_call_cnt = 0;
1667 
1668 #define CONT	 ({ insn++; goto select_insn; })
1669 #define CONT_JMP ({ insn++; goto select_insn; })
1670 
1671 select_insn:
1672 	goto *jumptable[insn->code];
1673 
1674 	/* Explicitly mask the register-based shift amounts with 63 or 31
1675 	 * to avoid undefined behavior. Normally this won't affect the
1676 	 * generated code, for example, in case of native 64 bit archs such
1677 	 * as x86-64 or arm64, the compiler is optimizing the AND away for
1678 	 * the interpreter. In case of JITs, each of the JIT backends compiles
1679 	 * the BPF shift operations to machine instructions which produce
1680 	 * implementation-defined results in such a case; the resulting
1681 	 * contents of the register may be arbitrary, but program behaviour
1682 	 * as a whole remains defined. In other words, in case of JIT backends,
1683 	 * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1684 	 */
1685 	/* ALU (shifts) */
1686 #define SHT(OPCODE, OP)					\
1687 	ALU64_##OPCODE##_X:				\
1688 		DST = DST OP (SRC & 63);		\
1689 		CONT;					\
1690 	ALU_##OPCODE##_X:				\
1691 		DST = (u32) DST OP ((u32) SRC & 31);	\
1692 		CONT;					\
1693 	ALU64_##OPCODE##_K:				\
1694 		DST = DST OP IMM;			\
1695 		CONT;					\
1696 	ALU_##OPCODE##_K:				\
1697 		DST = (u32) DST OP (u32) IMM;		\
1698 		CONT;
1699 	/* ALU (rest) */
1700 #define ALU(OPCODE, OP)					\
1701 	ALU64_##OPCODE##_X:				\
1702 		DST = DST OP SRC;			\
1703 		CONT;					\
1704 	ALU_##OPCODE##_X:				\
1705 		DST = (u32) DST OP (u32) SRC;		\
1706 		CONT;					\
1707 	ALU64_##OPCODE##_K:				\
1708 		DST = DST OP IMM;			\
1709 		CONT;					\
1710 	ALU_##OPCODE##_K:				\
1711 		DST = (u32) DST OP (u32) IMM;		\
1712 		CONT;
1713 	ALU(ADD,  +)
1714 	ALU(SUB,  -)
1715 	ALU(AND,  &)
1716 	ALU(OR,   |)
1717 	ALU(XOR,  ^)
1718 	ALU(MUL,  *)
1719 	SHT(LSH, <<)
1720 	SHT(RSH, >>)
1721 #undef SHT
1722 #undef ALU
1723 	ALU_NEG:
1724 		DST = (u32) -DST;
1725 		CONT;
1726 	ALU64_NEG:
1727 		DST = -DST;
1728 		CONT;
1729 	ALU_MOV_X:
1730 		DST = (u32) SRC;
1731 		CONT;
1732 	ALU_MOV_K:
1733 		DST = (u32) IMM;
1734 		CONT;
1735 	ALU64_MOV_X:
1736 		DST = SRC;
1737 		CONT;
1738 	ALU64_MOV_K:
1739 		DST = IMM;
1740 		CONT;
1741 	LD_IMM_DW:
1742 		DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1743 		insn++;
1744 		CONT;
1745 	ALU_ARSH_X:
1746 		DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1747 		CONT;
1748 	ALU_ARSH_K:
1749 		DST = (u64) (u32) (((s32) DST) >> IMM);
1750 		CONT;
1751 	ALU64_ARSH_X:
1752 		(*(s64 *) &DST) >>= (SRC & 63);
1753 		CONT;
1754 	ALU64_ARSH_K:
1755 		(*(s64 *) &DST) >>= IMM;
1756 		CONT;
1757 	ALU64_MOD_X:
1758 		div64_u64_rem(DST, SRC, &AX);
1759 		DST = AX;
1760 		CONT;
1761 	ALU_MOD_X:
1762 		AX = (u32) DST;
1763 		DST = do_div(AX, (u32) SRC);
1764 		CONT;
1765 	ALU64_MOD_K:
1766 		div64_u64_rem(DST, IMM, &AX);
1767 		DST = AX;
1768 		CONT;
1769 	ALU_MOD_K:
1770 		AX = (u32) DST;
1771 		DST = do_div(AX, (u32) IMM);
1772 		CONT;
1773 	ALU64_DIV_X:
1774 		DST = div64_u64(DST, SRC);
1775 		CONT;
1776 	ALU_DIV_X:
1777 		AX = (u32) DST;
1778 		do_div(AX, (u32) SRC);
1779 		DST = (u32) AX;
1780 		CONT;
1781 	ALU64_DIV_K:
1782 		DST = div64_u64(DST, IMM);
1783 		CONT;
1784 	ALU_DIV_K:
1785 		AX = (u32) DST;
1786 		do_div(AX, (u32) IMM);
1787 		DST = (u32) AX;
1788 		CONT;
1789 	ALU_END_TO_BE:
1790 		switch (IMM) {
1791 		case 16:
1792 			DST = (__force u16) cpu_to_be16(DST);
1793 			break;
1794 		case 32:
1795 			DST = (__force u32) cpu_to_be32(DST);
1796 			break;
1797 		case 64:
1798 			DST = (__force u64) cpu_to_be64(DST);
1799 			break;
1800 		}
1801 		CONT;
1802 	ALU_END_TO_LE:
1803 		switch (IMM) {
1804 		case 16:
1805 			DST = (__force u16) cpu_to_le16(DST);
1806 			break;
1807 		case 32:
1808 			DST = (__force u32) cpu_to_le32(DST);
1809 			break;
1810 		case 64:
1811 			DST = (__force u64) cpu_to_le64(DST);
1812 			break;
1813 		}
1814 		CONT;
1815 
1816 	/* CALL */
1817 	JMP_CALL:
1818 		/* Function call scratches BPF_R1-BPF_R5 registers,
1819 		 * preserves BPF_R6-BPF_R9, and stores return value
1820 		 * into BPF_R0.
1821 		 */
1822 		BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1823 						       BPF_R4, BPF_R5);
1824 		CONT;
1825 
1826 	JMP_CALL_ARGS:
1827 		BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
1828 							    BPF_R3, BPF_R4,
1829 							    BPF_R5,
1830 							    insn + insn->off + 1);
1831 		CONT;
1832 
1833 	JMP_TAIL_CALL: {
1834 		struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1835 		struct bpf_array *array = container_of(map, struct bpf_array, map);
1836 		struct bpf_prog *prog;
1837 		u32 index = BPF_R3;
1838 
1839 		if (unlikely(index >= array->map.max_entries))
1840 			goto out;
1841 
1842 		if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
1843 			goto out;
1844 
1845 		tail_call_cnt++;
1846 
1847 		prog = READ_ONCE(array->ptrs[index]);
1848 		if (!prog)
1849 			goto out;
1850 
1851 		/* ARG1 at this point is guaranteed to point to CTX from
1852 		 * the verifier side due to the fact that the tail call is
1853 		 * handled like a helper, that is, bpf_tail_call_proto,
1854 		 * where arg1_type is ARG_PTR_TO_CTX.
1855 		 */
1856 		insn = prog->insnsi;
1857 		goto select_insn;
1858 out:
1859 		CONT;
1860 	}
1861 	JMP_JA:
1862 		insn += insn->off;
1863 		CONT;
1864 	JMP_EXIT:
1865 		return BPF_R0;
1866 	/* JMP */
1867 #define COND_JMP(SIGN, OPCODE, CMP_OP)				\
1868 	JMP_##OPCODE##_X:					\
1869 		if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {	\
1870 			insn += insn->off;			\
1871 			CONT_JMP;				\
1872 		}						\
1873 		CONT;						\
1874 	JMP32_##OPCODE##_X:					\
1875 		if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {	\
1876 			insn += insn->off;			\
1877 			CONT_JMP;				\
1878 		}						\
1879 		CONT;						\
1880 	JMP_##OPCODE##_K:					\
1881 		if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {	\
1882 			insn += insn->off;			\
1883 			CONT_JMP;				\
1884 		}						\
1885 		CONT;						\
1886 	JMP32_##OPCODE##_K:					\
1887 		if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {	\
1888 			insn += insn->off;			\
1889 			CONT_JMP;				\
1890 		}						\
1891 		CONT;
1892 	COND_JMP(u, JEQ, ==)
1893 	COND_JMP(u, JNE, !=)
1894 	COND_JMP(u, JGT, >)
1895 	COND_JMP(u, JLT, <)
1896 	COND_JMP(u, JGE, >=)
1897 	COND_JMP(u, JLE, <=)
1898 	COND_JMP(u, JSET, &)
1899 	COND_JMP(s, JSGT, >)
1900 	COND_JMP(s, JSLT, <)
1901 	COND_JMP(s, JSGE, >=)
1902 	COND_JMP(s, JSLE, <=)
1903 #undef COND_JMP
1904 	/* ST, STX and LDX*/
1905 	ST_NOSPEC:
1906 		/* Speculation barrier for mitigating Speculative Store Bypass.
1907 		 * In case of arm64, we rely on the firmware mitigation as
1908 		 * controlled via the ssbd kernel parameter. Whenever the
1909 		 * mitigation is enabled, it works for all of the kernel code
1910 		 * with no need to provide any additional instructions here.
1911 		 * In case of x86, we use 'lfence' insn for mitigation. We
1912 		 * reuse preexisting logic from Spectre v1 mitigation that
1913 		 * happens to produce the required code on x86 for v4 as well.
1914 		 */
1915 #ifdef CONFIG_X86
1916 		barrier_nospec();
1917 #endif
1918 		CONT;
1919 #define LDST(SIZEOP, SIZE)						\
1920 	STX_MEM_##SIZEOP:						\
1921 		*(SIZE *)(unsigned long) (DST + insn->off) = SRC;	\
1922 		CONT;							\
1923 	ST_MEM_##SIZEOP:						\
1924 		*(SIZE *)(unsigned long) (DST + insn->off) = IMM;	\
1925 		CONT;							\
1926 	LDX_MEM_##SIZEOP:						\
1927 		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
1928 		CONT;							\
1929 	LDX_PROBE_MEM_##SIZEOP:						\
1930 		bpf_probe_read_kernel(&DST, sizeof(SIZE),		\
1931 				      (const void *)(long) (SRC + insn->off));	\
1932 		DST = *((SIZE *)&DST);					\
1933 		CONT;
1934 
1935 	LDST(B,   u8)
1936 	LDST(H,  u16)
1937 	LDST(W,  u32)
1938 	LDST(DW, u64)
1939 #undef LDST
1940 
1941 #define ATOMIC_ALU_OP(BOP, KOP)						\
1942 		case BOP:						\
1943 			if (BPF_SIZE(insn->code) == BPF_W)		\
1944 				atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
1945 					     (DST + insn->off));	\
1946 			else						\
1947 				atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
1948 					       (DST + insn->off));	\
1949 			break;						\
1950 		case BOP | BPF_FETCH:					\
1951 			if (BPF_SIZE(insn->code) == BPF_W)		\
1952 				SRC = (u32) atomic_fetch_##KOP(		\
1953 					(u32) SRC,			\
1954 					(atomic_t *)(unsigned long) (DST + insn->off)); \
1955 			else						\
1956 				SRC = (u64) atomic64_fetch_##KOP(	\
1957 					(u64) SRC,			\
1958 					(atomic64_t *)(unsigned long) (DST + insn->off)); \
1959 			break;
1960 
1961 	STX_ATOMIC_DW:
1962 	STX_ATOMIC_W:
1963 		switch (IMM) {
1964 		ATOMIC_ALU_OP(BPF_ADD, add)
1965 		ATOMIC_ALU_OP(BPF_AND, and)
1966 		ATOMIC_ALU_OP(BPF_OR, or)
1967 		ATOMIC_ALU_OP(BPF_XOR, xor)
1968 #undef ATOMIC_ALU_OP
1969 
1970 		case BPF_XCHG:
1971 			if (BPF_SIZE(insn->code) == BPF_W)
1972 				SRC = (u32) atomic_xchg(
1973 					(atomic_t *)(unsigned long) (DST + insn->off),
1974 					(u32) SRC);
1975 			else
1976 				SRC = (u64) atomic64_xchg(
1977 					(atomic64_t *)(unsigned long) (DST + insn->off),
1978 					(u64) SRC);
1979 			break;
1980 		case BPF_CMPXCHG:
1981 			if (BPF_SIZE(insn->code) == BPF_W)
1982 				BPF_R0 = (u32) atomic_cmpxchg(
1983 					(atomic_t *)(unsigned long) (DST + insn->off),
1984 					(u32) BPF_R0, (u32) SRC);
1985 			else
1986 				BPF_R0 = (u64) atomic64_cmpxchg(
1987 					(atomic64_t *)(unsigned long) (DST + insn->off),
1988 					(u64) BPF_R0, (u64) SRC);
1989 			break;
1990 
1991 		default:
1992 			goto default_label;
1993 		}
1994 		CONT;
1995 
1996 	default_label:
1997 		/* If we ever reach this, we have a bug somewhere. Die hard here
1998 		 * instead of just returning 0; we could be somewhere in a subprog,
1999 		 * so execution could continue otherwise which we do /not/ want.
2000 		 *
2001 		 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2002 		 */
2003 		pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2004 			insn->code, insn->imm);
2005 		BUG_ON(1);
2006 		return 0;
2007 }
2008 
2009 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2010 #define DEFINE_BPF_PROG_RUN(stack_size) \
2011 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2012 { \
2013 	u64 stack[stack_size / sizeof(u64)]; \
2014 	u64 regs[MAX_BPF_EXT_REG] = {}; \
2015 \
2016 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2017 	ARG1 = (u64) (unsigned long) ctx; \
2018 	return ___bpf_prog_run(regs, insn); \
2019 }
2020 
2021 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2022 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2023 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2024 				      const struct bpf_insn *insn) \
2025 { \
2026 	u64 stack[stack_size / sizeof(u64)]; \
2027 	u64 regs[MAX_BPF_EXT_REG]; \
2028 \
2029 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2030 	BPF_R1 = r1; \
2031 	BPF_R2 = r2; \
2032 	BPF_R3 = r3; \
2033 	BPF_R4 = r4; \
2034 	BPF_R5 = r5; \
2035 	return ___bpf_prog_run(regs, insn); \
2036 }
2037 
2038 #define EVAL1(FN, X) FN(X)
2039 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2040 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2041 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2042 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2043 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2044 
2045 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2046 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2047 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2048 
2049 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2050 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2051 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2052 
2053 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2054 
2055 static unsigned int (*interpreters[])(const void *ctx,
2056 				      const struct bpf_insn *insn) = {
2057 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2058 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2059 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2060 };
2061 #undef PROG_NAME_LIST
2062 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2063 static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2064 				  const struct bpf_insn *insn) = {
2065 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2066 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2067 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2068 };
2069 #undef PROG_NAME_LIST
2070 
2071 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2072 {
2073 	stack_depth = max_t(u32, stack_depth, 1);
2074 	insn->off = (s16) insn->imm;
2075 	insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
2076 		__bpf_call_base_args;
2077 	insn->code = BPF_JMP | BPF_CALL_ARGS;
2078 }
2079 
2080 #else
2081 static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2082 					 const struct bpf_insn *insn)
2083 {
2084 	/* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2085 	 * is not working properly, so warn about it!
2086 	 */
2087 	WARN_ON_ONCE(1);
2088 	return 0;
2089 }
2090 #endif
2091 
2092 bool bpf_prog_map_compatible(struct bpf_map *map,
2093 			     const struct bpf_prog *fp)
2094 {
2095 	bool ret;
2096 
2097 	if (fp->kprobe_override)
2098 		return false;
2099 
2100 	spin_lock(&map->owner.lock);
2101 	if (!map->owner.type) {
2102 		/* There's no owner yet where we could check for
2103 		 * compatibility.
2104 		 */
2105 		map->owner.type  = fp->type;
2106 		map->owner.jited = fp->jited;
2107 		map->owner.xdp_has_frags = fp->aux->xdp_has_frags;
2108 		ret = true;
2109 	} else {
2110 		ret = map->owner.type  == fp->type &&
2111 		      map->owner.jited == fp->jited &&
2112 		      map->owner.xdp_has_frags == fp->aux->xdp_has_frags;
2113 	}
2114 	spin_unlock(&map->owner.lock);
2115 
2116 	return ret;
2117 }
2118 
2119 static int bpf_check_tail_call(const struct bpf_prog *fp)
2120 {
2121 	struct bpf_prog_aux *aux = fp->aux;
2122 	int i, ret = 0;
2123 
2124 	mutex_lock(&aux->used_maps_mutex);
2125 	for (i = 0; i < aux->used_map_cnt; i++) {
2126 		struct bpf_map *map = aux->used_maps[i];
2127 
2128 		if (!map_type_contains_progs(map))
2129 			continue;
2130 
2131 		if (!bpf_prog_map_compatible(map, fp)) {
2132 			ret = -EINVAL;
2133 			goto out;
2134 		}
2135 	}
2136 
2137 out:
2138 	mutex_unlock(&aux->used_maps_mutex);
2139 	return ret;
2140 }
2141 
2142 static void bpf_prog_select_func(struct bpf_prog *fp)
2143 {
2144 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
2145 	u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2146 
2147 	fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
2148 #else
2149 	fp->bpf_func = __bpf_prog_ret0_warn;
2150 #endif
2151 }
2152 
2153 /**
2154  *	bpf_prog_select_runtime - select exec runtime for BPF program
2155  *	@fp: bpf_prog populated with BPF program
2156  *	@err: pointer to error variable
2157  *
2158  * Try to JIT eBPF program, if JIT is not available, use interpreter.
2159  * The BPF program will be executed via bpf_prog_run() function.
2160  *
2161  * Return: the &fp argument along with &err set to 0 for success or
2162  * a negative errno code on failure
2163  */
2164 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2165 {
2166 	/* In case of BPF to BPF calls, verifier did all the prep
2167 	 * work with regards to JITing, etc.
2168 	 */
2169 	bool jit_needed = false;
2170 
2171 	if (fp->bpf_func)
2172 		goto finalize;
2173 
2174 	if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
2175 	    bpf_prog_has_kfunc_call(fp))
2176 		jit_needed = true;
2177 
2178 	bpf_prog_select_func(fp);
2179 
2180 	/* eBPF JITs can rewrite the program in case constant
2181 	 * blinding is active. However, in case of error during
2182 	 * blinding, bpf_int_jit_compile() must always return a
2183 	 * valid program, which in this case would simply not
2184 	 * be JITed, but falls back to the interpreter.
2185 	 */
2186 	if (!bpf_prog_is_dev_bound(fp->aux)) {
2187 		*err = bpf_prog_alloc_jited_linfo(fp);
2188 		if (*err)
2189 			return fp;
2190 
2191 		fp = bpf_int_jit_compile(fp);
2192 		bpf_prog_jit_attempt_done(fp);
2193 		if (!fp->jited && jit_needed) {
2194 			*err = -ENOTSUPP;
2195 			return fp;
2196 		}
2197 	} else {
2198 		*err = bpf_prog_offload_compile(fp);
2199 		if (*err)
2200 			return fp;
2201 	}
2202 
2203 finalize:
2204 	bpf_prog_lock_ro(fp);
2205 
2206 	/* The tail call compatibility check can only be done at
2207 	 * this late stage as we need to determine, if we deal
2208 	 * with JITed or non JITed program concatenations and not
2209 	 * all eBPF JITs might immediately support all features.
2210 	 */
2211 	*err = bpf_check_tail_call(fp);
2212 
2213 	return fp;
2214 }
2215 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2216 
2217 static unsigned int __bpf_prog_ret1(const void *ctx,
2218 				    const struct bpf_insn *insn)
2219 {
2220 	return 1;
2221 }
2222 
2223 static struct bpf_prog_dummy {
2224 	struct bpf_prog prog;
2225 } dummy_bpf_prog = {
2226 	.prog = {
2227 		.bpf_func = __bpf_prog_ret1,
2228 	},
2229 };
2230 
2231 struct bpf_empty_prog_array bpf_empty_prog_array = {
2232 	.null_prog = NULL,
2233 };
2234 EXPORT_SYMBOL(bpf_empty_prog_array);
2235 
2236 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2237 {
2238 	if (prog_cnt)
2239 		return kzalloc(sizeof(struct bpf_prog_array) +
2240 			       sizeof(struct bpf_prog_array_item) *
2241 			       (prog_cnt + 1),
2242 			       flags);
2243 
2244 	return &bpf_empty_prog_array.hdr;
2245 }
2246 
2247 void bpf_prog_array_free(struct bpf_prog_array *progs)
2248 {
2249 	if (!progs || progs == &bpf_empty_prog_array.hdr)
2250 		return;
2251 	kfree_rcu(progs, rcu);
2252 }
2253 
2254 static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2255 {
2256 	struct bpf_prog_array *progs;
2257 
2258 	/* If RCU Tasks Trace grace period implies RCU grace period, there is
2259 	 * no need to call kfree_rcu(), just call kfree() directly.
2260 	 */
2261 	progs = container_of(rcu, struct bpf_prog_array, rcu);
2262 	if (rcu_trace_implies_rcu_gp())
2263 		kfree(progs);
2264 	else
2265 		kfree_rcu(progs, rcu);
2266 }
2267 
2268 void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2269 {
2270 	if (!progs || progs == &bpf_empty_prog_array.hdr)
2271 		return;
2272 	call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2273 }
2274 
2275 int bpf_prog_array_length(struct bpf_prog_array *array)
2276 {
2277 	struct bpf_prog_array_item *item;
2278 	u32 cnt = 0;
2279 
2280 	for (item = array->items; item->prog; item++)
2281 		if (item->prog != &dummy_bpf_prog.prog)
2282 			cnt++;
2283 	return cnt;
2284 }
2285 
2286 bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2287 {
2288 	struct bpf_prog_array_item *item;
2289 
2290 	for (item = array->items; item->prog; item++)
2291 		if (item->prog != &dummy_bpf_prog.prog)
2292 			return false;
2293 	return true;
2294 }
2295 
2296 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2297 				     u32 *prog_ids,
2298 				     u32 request_cnt)
2299 {
2300 	struct bpf_prog_array_item *item;
2301 	int i = 0;
2302 
2303 	for (item = array->items; item->prog; item++) {
2304 		if (item->prog == &dummy_bpf_prog.prog)
2305 			continue;
2306 		prog_ids[i] = item->prog->aux->id;
2307 		if (++i == request_cnt) {
2308 			item++;
2309 			break;
2310 		}
2311 	}
2312 
2313 	return !!(item->prog);
2314 }
2315 
2316 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2317 				__u32 __user *prog_ids, u32 cnt)
2318 {
2319 	unsigned long err = 0;
2320 	bool nospc;
2321 	u32 *ids;
2322 
2323 	/* users of this function are doing:
2324 	 * cnt = bpf_prog_array_length();
2325 	 * if (cnt > 0)
2326 	 *     bpf_prog_array_copy_to_user(..., cnt);
2327 	 * so below kcalloc doesn't need extra cnt > 0 check.
2328 	 */
2329 	ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2330 	if (!ids)
2331 		return -ENOMEM;
2332 	nospc = bpf_prog_array_copy_core(array, ids, cnt);
2333 	err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2334 	kfree(ids);
2335 	if (err)
2336 		return -EFAULT;
2337 	if (nospc)
2338 		return -ENOSPC;
2339 	return 0;
2340 }
2341 
2342 void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2343 				struct bpf_prog *old_prog)
2344 {
2345 	struct bpf_prog_array_item *item;
2346 
2347 	for (item = array->items; item->prog; item++)
2348 		if (item->prog == old_prog) {
2349 			WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2350 			break;
2351 		}
2352 }
2353 
2354 /**
2355  * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2356  *                                   index into the program array with
2357  *                                   a dummy no-op program.
2358  * @array: a bpf_prog_array
2359  * @index: the index of the program to replace
2360  *
2361  * Skips over dummy programs, by not counting them, when calculating
2362  * the position of the program to replace.
2363  *
2364  * Return:
2365  * * 0		- Success
2366  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2367  * * -ENOENT	- Index out of range
2368  */
2369 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2370 {
2371 	return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2372 }
2373 
2374 /**
2375  * bpf_prog_array_update_at() - Updates the program at the given index
2376  *                              into the program array.
2377  * @array: a bpf_prog_array
2378  * @index: the index of the program to update
2379  * @prog: the program to insert into the array
2380  *
2381  * Skips over dummy programs, by not counting them, when calculating
2382  * the position of the program to update.
2383  *
2384  * Return:
2385  * * 0		- Success
2386  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2387  * * -ENOENT	- Index out of range
2388  */
2389 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2390 			     struct bpf_prog *prog)
2391 {
2392 	struct bpf_prog_array_item *item;
2393 
2394 	if (unlikely(index < 0))
2395 		return -EINVAL;
2396 
2397 	for (item = array->items; item->prog; item++) {
2398 		if (item->prog == &dummy_bpf_prog.prog)
2399 			continue;
2400 		if (!index) {
2401 			WRITE_ONCE(item->prog, prog);
2402 			return 0;
2403 		}
2404 		index--;
2405 	}
2406 	return -ENOENT;
2407 }
2408 
2409 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2410 			struct bpf_prog *exclude_prog,
2411 			struct bpf_prog *include_prog,
2412 			u64 bpf_cookie,
2413 			struct bpf_prog_array **new_array)
2414 {
2415 	int new_prog_cnt, carry_prog_cnt = 0;
2416 	struct bpf_prog_array_item *existing, *new;
2417 	struct bpf_prog_array *array;
2418 	bool found_exclude = false;
2419 
2420 	/* Figure out how many existing progs we need to carry over to
2421 	 * the new array.
2422 	 */
2423 	if (old_array) {
2424 		existing = old_array->items;
2425 		for (; existing->prog; existing++) {
2426 			if (existing->prog == exclude_prog) {
2427 				found_exclude = true;
2428 				continue;
2429 			}
2430 			if (existing->prog != &dummy_bpf_prog.prog)
2431 				carry_prog_cnt++;
2432 			if (existing->prog == include_prog)
2433 				return -EEXIST;
2434 		}
2435 	}
2436 
2437 	if (exclude_prog && !found_exclude)
2438 		return -ENOENT;
2439 
2440 	/* How many progs (not NULL) will be in the new array? */
2441 	new_prog_cnt = carry_prog_cnt;
2442 	if (include_prog)
2443 		new_prog_cnt += 1;
2444 
2445 	/* Do we have any prog (not NULL) in the new array? */
2446 	if (!new_prog_cnt) {
2447 		*new_array = NULL;
2448 		return 0;
2449 	}
2450 
2451 	/* +1 as the end of prog_array is marked with NULL */
2452 	array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2453 	if (!array)
2454 		return -ENOMEM;
2455 	new = array->items;
2456 
2457 	/* Fill in the new prog array */
2458 	if (carry_prog_cnt) {
2459 		existing = old_array->items;
2460 		for (; existing->prog; existing++) {
2461 			if (existing->prog == exclude_prog ||
2462 			    existing->prog == &dummy_bpf_prog.prog)
2463 				continue;
2464 
2465 			new->prog = existing->prog;
2466 			new->bpf_cookie = existing->bpf_cookie;
2467 			new++;
2468 		}
2469 	}
2470 	if (include_prog) {
2471 		new->prog = include_prog;
2472 		new->bpf_cookie = bpf_cookie;
2473 		new++;
2474 	}
2475 	new->prog = NULL;
2476 	*new_array = array;
2477 	return 0;
2478 }
2479 
2480 int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2481 			     u32 *prog_ids, u32 request_cnt,
2482 			     u32 *prog_cnt)
2483 {
2484 	u32 cnt = 0;
2485 
2486 	if (array)
2487 		cnt = bpf_prog_array_length(array);
2488 
2489 	*prog_cnt = cnt;
2490 
2491 	/* return early if user requested only program count or nothing to copy */
2492 	if (!request_cnt || !cnt)
2493 		return 0;
2494 
2495 	/* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2496 	return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2497 								     : 0;
2498 }
2499 
2500 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2501 			  struct bpf_map **used_maps, u32 len)
2502 {
2503 	struct bpf_map *map;
2504 	u32 i;
2505 
2506 	for (i = 0; i < len; i++) {
2507 		map = used_maps[i];
2508 		if (map->ops->map_poke_untrack)
2509 			map->ops->map_poke_untrack(map, aux);
2510 		bpf_map_put(map);
2511 	}
2512 }
2513 
2514 static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2515 {
2516 	__bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2517 	kfree(aux->used_maps);
2518 }
2519 
2520 void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
2521 			  struct btf_mod_pair *used_btfs, u32 len)
2522 {
2523 #ifdef CONFIG_BPF_SYSCALL
2524 	struct btf_mod_pair *btf_mod;
2525 	u32 i;
2526 
2527 	for (i = 0; i < len; i++) {
2528 		btf_mod = &used_btfs[i];
2529 		if (btf_mod->module)
2530 			module_put(btf_mod->module);
2531 		btf_put(btf_mod->btf);
2532 	}
2533 #endif
2534 }
2535 
2536 static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2537 {
2538 	__bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt);
2539 	kfree(aux->used_btfs);
2540 }
2541 
2542 static void bpf_prog_free_deferred(struct work_struct *work)
2543 {
2544 	struct bpf_prog_aux *aux;
2545 	int i;
2546 
2547 	aux = container_of(work, struct bpf_prog_aux, work);
2548 #ifdef CONFIG_BPF_SYSCALL
2549 	bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
2550 #endif
2551 #ifdef CONFIG_CGROUP_BPF
2552 	if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
2553 		bpf_cgroup_atype_put(aux->cgroup_atype);
2554 #endif
2555 	bpf_free_used_maps(aux);
2556 	bpf_free_used_btfs(aux);
2557 	if (bpf_prog_is_dev_bound(aux))
2558 		bpf_prog_offload_destroy(aux->prog);
2559 #ifdef CONFIG_PERF_EVENTS
2560 	if (aux->prog->has_callchain_buf)
2561 		put_callchain_buffers();
2562 #endif
2563 	if (aux->dst_trampoline)
2564 		bpf_trampoline_put(aux->dst_trampoline);
2565 	for (i = 0; i < aux->func_cnt; i++) {
2566 		/* We can just unlink the subprog poke descriptor table as
2567 		 * it was originally linked to the main program and is also
2568 		 * released along with it.
2569 		 */
2570 		aux->func[i]->aux->poke_tab = NULL;
2571 		bpf_jit_free(aux->func[i]);
2572 	}
2573 	if (aux->func_cnt) {
2574 		kfree(aux->func);
2575 		bpf_prog_unlock_free(aux->prog);
2576 	} else {
2577 		bpf_jit_free(aux->prog);
2578 	}
2579 }
2580 
2581 void bpf_prog_free(struct bpf_prog *fp)
2582 {
2583 	struct bpf_prog_aux *aux = fp->aux;
2584 
2585 	if (aux->dst_prog)
2586 		bpf_prog_put(aux->dst_prog);
2587 	INIT_WORK(&aux->work, bpf_prog_free_deferred);
2588 	schedule_work(&aux->work);
2589 }
2590 EXPORT_SYMBOL_GPL(bpf_prog_free);
2591 
2592 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
2593 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2594 
2595 void bpf_user_rnd_init_once(void)
2596 {
2597 	prandom_init_once(&bpf_user_rnd_state);
2598 }
2599 
2600 BPF_CALL_0(bpf_user_rnd_u32)
2601 {
2602 	/* Should someone ever have the rather unwise idea to use some
2603 	 * of the registers passed into this function, then note that
2604 	 * this function is called from native eBPF and classic-to-eBPF
2605 	 * transformations. Register assignments from both sides are
2606 	 * different, f.e. classic always sets fn(ctx, A, X) here.
2607 	 */
2608 	struct rnd_state *state;
2609 	u32 res;
2610 
2611 	state = &get_cpu_var(bpf_user_rnd_state);
2612 	res = prandom_u32_state(state);
2613 	put_cpu_var(bpf_user_rnd_state);
2614 
2615 	return res;
2616 }
2617 
2618 BPF_CALL_0(bpf_get_raw_cpu_id)
2619 {
2620 	return raw_smp_processor_id();
2621 }
2622 
2623 /* Weak definitions of helper functions in case we don't have bpf syscall. */
2624 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2625 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2626 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2627 const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2628 const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2629 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2630 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
2631 const struct bpf_func_proto bpf_spin_lock_proto __weak;
2632 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2633 const struct bpf_func_proto bpf_jiffies64_proto __weak;
2634 
2635 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2636 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2637 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2638 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2639 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2640 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2641 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
2642 
2643 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2644 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2645 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2646 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2647 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2648 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2649 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2650 const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2651 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2652 const struct bpf_func_proto bpf_set_retval_proto __weak;
2653 const struct bpf_func_proto bpf_get_retval_proto __weak;
2654 
2655 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2656 {
2657 	return NULL;
2658 }
2659 
2660 const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
2661 {
2662 	return NULL;
2663 }
2664 
2665 u64 __weak
2666 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2667 		 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2668 {
2669 	return -ENOTSUPP;
2670 }
2671 EXPORT_SYMBOL_GPL(bpf_event_output);
2672 
2673 /* Always built-in helper functions. */
2674 const struct bpf_func_proto bpf_tail_call_proto = {
2675 	.func		= NULL,
2676 	.gpl_only	= false,
2677 	.ret_type	= RET_VOID,
2678 	.arg1_type	= ARG_PTR_TO_CTX,
2679 	.arg2_type	= ARG_CONST_MAP_PTR,
2680 	.arg3_type	= ARG_ANYTHING,
2681 };
2682 
2683 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2684  * It is encouraged to implement bpf_int_jit_compile() instead, so that
2685  * eBPF and implicitly also cBPF can get JITed!
2686  */
2687 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2688 {
2689 	return prog;
2690 }
2691 
2692 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
2693  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2694  */
2695 void __weak bpf_jit_compile(struct bpf_prog *prog)
2696 {
2697 }
2698 
2699 bool __weak bpf_helper_changes_pkt_data(void *func)
2700 {
2701 	return false;
2702 }
2703 
2704 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2705  * analysis code and wants explicit zero extension inserted by verifier.
2706  * Otherwise, return FALSE.
2707  *
2708  * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2709  * you don't override this. JITs that don't want these extra insns can detect
2710  * them using insn_is_zext.
2711  */
2712 bool __weak bpf_jit_needs_zext(void)
2713 {
2714 	return false;
2715 }
2716 
2717 /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
2718 bool __weak bpf_jit_supports_subprog_tailcalls(void)
2719 {
2720 	return false;
2721 }
2722 
2723 bool __weak bpf_jit_supports_kfunc_call(void)
2724 {
2725 	return false;
2726 }
2727 
2728 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
2729  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
2730  */
2731 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
2732 			 int len)
2733 {
2734 	return -EFAULT;
2735 }
2736 
2737 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
2738 			      void *addr1, void *addr2)
2739 {
2740 	return -ENOTSUPP;
2741 }
2742 
2743 void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
2744 {
2745 	return ERR_PTR(-ENOTSUPP);
2746 }
2747 
2748 int __weak bpf_arch_text_invalidate(void *dst, size_t len)
2749 {
2750 	return -ENOTSUPP;
2751 }
2752 
2753 #ifdef CONFIG_BPF_SYSCALL
2754 static int __init bpf_global_ma_init(void)
2755 {
2756 	int ret;
2757 
2758 	ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
2759 	bpf_global_ma_set = !ret;
2760 	return ret;
2761 }
2762 late_initcall(bpf_global_ma_init);
2763 #endif
2764 
2765 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
2766 EXPORT_SYMBOL(bpf_stats_enabled_key);
2767 
2768 /* All definitions of tracepoints related to BPF. */
2769 #define CREATE_TRACE_POINTS
2770 #include <linux/bpf_trace.h>
2771 
2772 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
2773 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);
2774