xref: /openbmc/linux/kernel/bpf/core.c (revision 27e45f2e)
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_rox((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE);
872 	return pack;
873 }
874 
875 void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
876 {
877 	unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
878 	struct bpf_prog_pack *pack;
879 	unsigned long pos;
880 	void *ptr = NULL;
881 
882 	mutex_lock(&pack_mutex);
883 	if (size > BPF_PROG_PACK_SIZE) {
884 		size = round_up(size, PAGE_SIZE);
885 		ptr = module_alloc(size);
886 		if (ptr) {
887 			bpf_fill_ill_insns(ptr, size);
888 			set_vm_flush_reset_perms(ptr);
889 			set_memory_rox((unsigned long)ptr, size / PAGE_SIZE);
890 		}
891 		goto out;
892 	}
893 	list_for_each_entry(pack, &pack_list, list) {
894 		pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
895 						 nbits, 0);
896 		if (pos < BPF_PROG_CHUNK_COUNT)
897 			goto found_free_area;
898 	}
899 
900 	pack = alloc_new_pack(bpf_fill_ill_insns);
901 	if (!pack)
902 		goto out;
903 
904 	pos = 0;
905 
906 found_free_area:
907 	bitmap_set(pack->bitmap, pos, nbits);
908 	ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
909 
910 out:
911 	mutex_unlock(&pack_mutex);
912 	return ptr;
913 }
914 
915 void bpf_prog_pack_free(struct bpf_binary_header *hdr)
916 {
917 	struct bpf_prog_pack *pack = NULL, *tmp;
918 	unsigned int nbits;
919 	unsigned long pos;
920 
921 	mutex_lock(&pack_mutex);
922 	if (hdr->size > BPF_PROG_PACK_SIZE) {
923 		module_memfree(hdr);
924 		goto out;
925 	}
926 
927 	list_for_each_entry(tmp, &pack_list, list) {
928 		if ((void *)hdr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > (void *)hdr) {
929 			pack = tmp;
930 			break;
931 		}
932 	}
933 
934 	if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
935 		goto out;
936 
937 	nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size);
938 	pos = ((unsigned long)hdr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
939 
940 	WARN_ONCE(bpf_arch_text_invalidate(hdr, hdr->size),
941 		  "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
942 
943 	bitmap_clear(pack->bitmap, pos, nbits);
944 	if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
945 				       BPF_PROG_CHUNK_COUNT, 0) == 0) {
946 		list_del(&pack->list);
947 		module_memfree(pack->ptr);
948 		kfree(pack);
949 	}
950 out:
951 	mutex_unlock(&pack_mutex);
952 }
953 
954 static atomic_long_t bpf_jit_current;
955 
956 /* Can be overridden by an arch's JIT compiler if it has a custom,
957  * dedicated BPF backend memory area, or if neither of the two
958  * below apply.
959  */
960 u64 __weak bpf_jit_alloc_exec_limit(void)
961 {
962 #if defined(MODULES_VADDR)
963 	return MODULES_END - MODULES_VADDR;
964 #else
965 	return VMALLOC_END - VMALLOC_START;
966 #endif
967 }
968 
969 static int __init bpf_jit_charge_init(void)
970 {
971 	/* Only used as heuristic here to derive limit. */
972 	bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
973 	bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 2,
974 					    PAGE_SIZE), LONG_MAX);
975 	return 0;
976 }
977 pure_initcall(bpf_jit_charge_init);
978 
979 int bpf_jit_charge_modmem(u32 size)
980 {
981 	if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
982 		if (!bpf_capable()) {
983 			atomic_long_sub(size, &bpf_jit_current);
984 			return -EPERM;
985 		}
986 	}
987 
988 	return 0;
989 }
990 
991 void bpf_jit_uncharge_modmem(u32 size)
992 {
993 	atomic_long_sub(size, &bpf_jit_current);
994 }
995 
996 void *__weak bpf_jit_alloc_exec(unsigned long size)
997 {
998 	return module_alloc(size);
999 }
1000 
1001 void __weak bpf_jit_free_exec(void *addr)
1002 {
1003 	module_memfree(addr);
1004 }
1005 
1006 struct bpf_binary_header *
1007 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1008 		     unsigned int alignment,
1009 		     bpf_jit_fill_hole_t bpf_fill_ill_insns)
1010 {
1011 	struct bpf_binary_header *hdr;
1012 	u32 size, hole, start;
1013 
1014 	WARN_ON_ONCE(!is_power_of_2(alignment) ||
1015 		     alignment > BPF_IMAGE_ALIGNMENT);
1016 
1017 	/* Most of BPF filters are really small, but if some of them
1018 	 * fill a page, allow at least 128 extra bytes to insert a
1019 	 * random section of illegal instructions.
1020 	 */
1021 	size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
1022 
1023 	if (bpf_jit_charge_modmem(size))
1024 		return NULL;
1025 	hdr = bpf_jit_alloc_exec(size);
1026 	if (!hdr) {
1027 		bpf_jit_uncharge_modmem(size);
1028 		return NULL;
1029 	}
1030 
1031 	/* Fill space with illegal/arch-dep instructions. */
1032 	bpf_fill_ill_insns(hdr, size);
1033 
1034 	hdr->size = size;
1035 	hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
1036 		     PAGE_SIZE - sizeof(*hdr));
1037 	start = get_random_u32_below(hole) & ~(alignment - 1);
1038 
1039 	/* Leave a random number of instructions before BPF code. */
1040 	*image_ptr = &hdr->image[start];
1041 
1042 	return hdr;
1043 }
1044 
1045 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
1046 {
1047 	u32 size = hdr->size;
1048 
1049 	bpf_jit_free_exec(hdr);
1050 	bpf_jit_uncharge_modmem(size);
1051 }
1052 
1053 /* Allocate jit binary from bpf_prog_pack allocator.
1054  * Since the allocated memory is RO+X, the JIT engine cannot write directly
1055  * to the memory. To solve this problem, a RW buffer is also allocated at
1056  * as the same time. The JIT engine should calculate offsets based on the
1057  * RO memory address, but write JITed program to the RW buffer. Once the
1058  * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
1059  * the JITed program to the RO memory.
1060  */
1061 struct bpf_binary_header *
1062 bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
1063 			  unsigned int alignment,
1064 			  struct bpf_binary_header **rw_header,
1065 			  u8 **rw_image,
1066 			  bpf_jit_fill_hole_t bpf_fill_ill_insns)
1067 {
1068 	struct bpf_binary_header *ro_header;
1069 	u32 size, hole, start;
1070 
1071 	WARN_ON_ONCE(!is_power_of_2(alignment) ||
1072 		     alignment > BPF_IMAGE_ALIGNMENT);
1073 
1074 	/* add 16 bytes for a random section of illegal instructions */
1075 	size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
1076 
1077 	if (bpf_jit_charge_modmem(size))
1078 		return NULL;
1079 	ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns);
1080 	if (!ro_header) {
1081 		bpf_jit_uncharge_modmem(size);
1082 		return NULL;
1083 	}
1084 
1085 	*rw_header = kvmalloc(size, GFP_KERNEL);
1086 	if (!*rw_header) {
1087 		bpf_arch_text_copy(&ro_header->size, &size, sizeof(size));
1088 		bpf_prog_pack_free(ro_header);
1089 		bpf_jit_uncharge_modmem(size);
1090 		return NULL;
1091 	}
1092 
1093 	/* Fill space with illegal/arch-dep instructions. */
1094 	bpf_fill_ill_insns(*rw_header, size);
1095 	(*rw_header)->size = size;
1096 
1097 	hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
1098 		     BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
1099 	start = get_random_u32_below(hole) & ~(alignment - 1);
1100 
1101 	*image_ptr = &ro_header->image[start];
1102 	*rw_image = &(*rw_header)->image[start];
1103 
1104 	return ro_header;
1105 }
1106 
1107 /* Copy JITed text from rw_header to its final location, the ro_header. */
1108 int bpf_jit_binary_pack_finalize(struct bpf_prog *prog,
1109 				 struct bpf_binary_header *ro_header,
1110 				 struct bpf_binary_header *rw_header)
1111 {
1112 	void *ptr;
1113 
1114 	ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
1115 
1116 	kvfree(rw_header);
1117 
1118 	if (IS_ERR(ptr)) {
1119 		bpf_prog_pack_free(ro_header);
1120 		return PTR_ERR(ptr);
1121 	}
1122 	return 0;
1123 }
1124 
1125 /* bpf_jit_binary_pack_free is called in two different scenarios:
1126  *   1) when the program is freed after;
1127  *   2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
1128  * For case 2), we need to free both the RO memory and the RW buffer.
1129  *
1130  * bpf_jit_binary_pack_free requires proper ro_header->size. However,
1131  * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
1132  * must be set with either bpf_jit_binary_pack_finalize (normal path) or
1133  * bpf_arch_text_copy (when jit fails).
1134  */
1135 void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
1136 			      struct bpf_binary_header *rw_header)
1137 {
1138 	u32 size = ro_header->size;
1139 
1140 	bpf_prog_pack_free(ro_header);
1141 	kvfree(rw_header);
1142 	bpf_jit_uncharge_modmem(size);
1143 }
1144 
1145 struct bpf_binary_header *
1146 bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
1147 {
1148 	unsigned long real_start = (unsigned long)fp->bpf_func;
1149 	unsigned long addr;
1150 
1151 	addr = real_start & BPF_PROG_CHUNK_MASK;
1152 	return (void *)addr;
1153 }
1154 
1155 static inline struct bpf_binary_header *
1156 bpf_jit_binary_hdr(const struct bpf_prog *fp)
1157 {
1158 	unsigned long real_start = (unsigned long)fp->bpf_func;
1159 	unsigned long addr;
1160 
1161 	addr = real_start & PAGE_MASK;
1162 	return (void *)addr;
1163 }
1164 
1165 /* This symbol is only overridden by archs that have different
1166  * requirements than the usual eBPF JITs, f.e. when they only
1167  * implement cBPF JIT, do not set images read-only, etc.
1168  */
1169 void __weak bpf_jit_free(struct bpf_prog *fp)
1170 {
1171 	if (fp->jited) {
1172 		struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
1173 
1174 		bpf_jit_binary_free(hdr);
1175 		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
1176 	}
1177 
1178 	bpf_prog_unlock_free(fp);
1179 }
1180 
1181 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1182 			  const struct bpf_insn *insn, bool extra_pass,
1183 			  u64 *func_addr, bool *func_addr_fixed)
1184 {
1185 	s16 off = insn->off;
1186 	s32 imm = insn->imm;
1187 	u8 *addr;
1188 
1189 	*func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1190 	if (!*func_addr_fixed) {
1191 		/* Place-holder address till the last pass has collected
1192 		 * all addresses for JITed subprograms in which case we
1193 		 * can pick them up from prog->aux.
1194 		 */
1195 		if (!extra_pass)
1196 			addr = NULL;
1197 		else if (prog->aux->func &&
1198 			 off >= 0 && off < prog->aux->func_cnt)
1199 			addr = (u8 *)prog->aux->func[off]->bpf_func;
1200 		else
1201 			return -EINVAL;
1202 	} else {
1203 		/* Address of a BPF helper call. Since part of the core
1204 		 * kernel, it's always at a fixed location. __bpf_call_base
1205 		 * and the helper with imm relative to it are both in core
1206 		 * kernel.
1207 		 */
1208 		addr = (u8 *)__bpf_call_base + imm;
1209 	}
1210 
1211 	*func_addr = (unsigned long)addr;
1212 	return 0;
1213 }
1214 
1215 static int bpf_jit_blind_insn(const struct bpf_insn *from,
1216 			      const struct bpf_insn *aux,
1217 			      struct bpf_insn *to_buff,
1218 			      bool emit_zext)
1219 {
1220 	struct bpf_insn *to = to_buff;
1221 	u32 imm_rnd = get_random_u32();
1222 	s16 off;
1223 
1224 	BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
1225 	BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
1226 
1227 	/* Constraints on AX register:
1228 	 *
1229 	 * AX register is inaccessible from user space. It is mapped in
1230 	 * all JITs, and used here for constant blinding rewrites. It is
1231 	 * typically "stateless" meaning its contents are only valid within
1232 	 * the executed instruction, but not across several instructions.
1233 	 * There are a few exceptions however which are further detailed
1234 	 * below.
1235 	 *
1236 	 * Constant blinding is only used by JITs, not in the interpreter.
1237 	 * The interpreter uses AX in some occasions as a local temporary
1238 	 * register e.g. in DIV or MOD instructions.
1239 	 *
1240 	 * In restricted circumstances, the verifier can also use the AX
1241 	 * register for rewrites as long as they do not interfere with
1242 	 * the above cases!
1243 	 */
1244 	if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1245 		goto out;
1246 
1247 	if (from->imm == 0 &&
1248 	    (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
1249 	     from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1250 		*to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1251 		goto out;
1252 	}
1253 
1254 	switch (from->code) {
1255 	case BPF_ALU | BPF_ADD | BPF_K:
1256 	case BPF_ALU | BPF_SUB | BPF_K:
1257 	case BPF_ALU | BPF_AND | BPF_K:
1258 	case BPF_ALU | BPF_OR  | BPF_K:
1259 	case BPF_ALU | BPF_XOR | BPF_K:
1260 	case BPF_ALU | BPF_MUL | BPF_K:
1261 	case BPF_ALU | BPF_MOV | BPF_K:
1262 	case BPF_ALU | BPF_DIV | BPF_K:
1263 	case BPF_ALU | BPF_MOD | BPF_K:
1264 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1265 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1266 		*to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
1267 		break;
1268 
1269 	case BPF_ALU64 | BPF_ADD | BPF_K:
1270 	case BPF_ALU64 | BPF_SUB | BPF_K:
1271 	case BPF_ALU64 | BPF_AND | BPF_K:
1272 	case BPF_ALU64 | BPF_OR  | BPF_K:
1273 	case BPF_ALU64 | BPF_XOR | BPF_K:
1274 	case BPF_ALU64 | BPF_MUL | BPF_K:
1275 	case BPF_ALU64 | BPF_MOV | BPF_K:
1276 	case BPF_ALU64 | BPF_DIV | BPF_K:
1277 	case BPF_ALU64 | BPF_MOD | BPF_K:
1278 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1279 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1280 		*to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
1281 		break;
1282 
1283 	case BPF_JMP | BPF_JEQ  | BPF_K:
1284 	case BPF_JMP | BPF_JNE  | BPF_K:
1285 	case BPF_JMP | BPF_JGT  | BPF_K:
1286 	case BPF_JMP | BPF_JLT  | BPF_K:
1287 	case BPF_JMP | BPF_JGE  | BPF_K:
1288 	case BPF_JMP | BPF_JLE  | BPF_K:
1289 	case BPF_JMP | BPF_JSGT | BPF_K:
1290 	case BPF_JMP | BPF_JSLT | BPF_K:
1291 	case BPF_JMP | BPF_JSGE | BPF_K:
1292 	case BPF_JMP | BPF_JSLE | BPF_K:
1293 	case BPF_JMP | BPF_JSET | BPF_K:
1294 		/* Accommodate for extra offset in case of a backjump. */
1295 		off = from->off;
1296 		if (off < 0)
1297 			off -= 2;
1298 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1299 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1300 		*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1301 		break;
1302 
1303 	case BPF_JMP32 | BPF_JEQ  | BPF_K:
1304 	case BPF_JMP32 | BPF_JNE  | BPF_K:
1305 	case BPF_JMP32 | BPF_JGT  | BPF_K:
1306 	case BPF_JMP32 | BPF_JLT  | BPF_K:
1307 	case BPF_JMP32 | BPF_JGE  | BPF_K:
1308 	case BPF_JMP32 | BPF_JLE  | BPF_K:
1309 	case BPF_JMP32 | BPF_JSGT | BPF_K:
1310 	case BPF_JMP32 | BPF_JSLT | BPF_K:
1311 	case BPF_JMP32 | BPF_JSGE | BPF_K:
1312 	case BPF_JMP32 | BPF_JSLE | BPF_K:
1313 	case BPF_JMP32 | BPF_JSET | BPF_K:
1314 		/* Accommodate for extra offset in case of a backjump. */
1315 		off = from->off;
1316 		if (off < 0)
1317 			off -= 2;
1318 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1319 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1320 		*to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1321 				      off);
1322 		break;
1323 
1324 	case BPF_LD | BPF_IMM | BPF_DW:
1325 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1326 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1327 		*to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1328 		*to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1329 		break;
1330 	case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1331 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1332 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1333 		if (emit_zext)
1334 			*to++ = BPF_ZEXT_REG(BPF_REG_AX);
1335 		*to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
1336 		break;
1337 
1338 	case BPF_ST | BPF_MEM | BPF_DW:
1339 	case BPF_ST | BPF_MEM | BPF_W:
1340 	case BPF_ST | BPF_MEM | BPF_H:
1341 	case BPF_ST | BPF_MEM | BPF_B:
1342 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1343 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1344 		*to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1345 		break;
1346 	}
1347 out:
1348 	return to - to_buff;
1349 }
1350 
1351 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1352 					      gfp_t gfp_extra_flags)
1353 {
1354 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1355 	struct bpf_prog *fp;
1356 
1357 	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1358 	if (fp != NULL) {
1359 		/* aux->prog still points to the fp_other one, so
1360 		 * when promoting the clone to the real program,
1361 		 * this still needs to be adapted.
1362 		 */
1363 		memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1364 	}
1365 
1366 	return fp;
1367 }
1368 
1369 static void bpf_prog_clone_free(struct bpf_prog *fp)
1370 {
1371 	/* aux was stolen by the other clone, so we cannot free
1372 	 * it from this path! It will be freed eventually by the
1373 	 * other program on release.
1374 	 *
1375 	 * At this point, we don't need a deferred release since
1376 	 * clone is guaranteed to not be locked.
1377 	 */
1378 	fp->aux = NULL;
1379 	fp->stats = NULL;
1380 	fp->active = NULL;
1381 	__bpf_prog_free(fp);
1382 }
1383 
1384 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1385 {
1386 	/* We have to repoint aux->prog to self, as we don't
1387 	 * know whether fp here is the clone or the original.
1388 	 */
1389 	fp->aux->prog = fp;
1390 	bpf_prog_clone_free(fp_other);
1391 }
1392 
1393 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1394 {
1395 	struct bpf_insn insn_buff[16], aux[2];
1396 	struct bpf_prog *clone, *tmp;
1397 	int insn_delta, insn_cnt;
1398 	struct bpf_insn *insn;
1399 	int i, rewritten;
1400 
1401 	if (!prog->blinding_requested || prog->blinded)
1402 		return prog;
1403 
1404 	clone = bpf_prog_clone_create(prog, GFP_USER);
1405 	if (!clone)
1406 		return ERR_PTR(-ENOMEM);
1407 
1408 	insn_cnt = clone->len;
1409 	insn = clone->insnsi;
1410 
1411 	for (i = 0; i < insn_cnt; i++, insn++) {
1412 		if (bpf_pseudo_func(insn)) {
1413 			/* ld_imm64 with an address of bpf subprog is not
1414 			 * a user controlled constant. Don't randomize it,
1415 			 * since it will conflict with jit_subprogs() logic.
1416 			 */
1417 			insn++;
1418 			i++;
1419 			continue;
1420 		}
1421 
1422 		/* We temporarily need to hold the original ld64 insn
1423 		 * so that we can still access the first part in the
1424 		 * second blinding run.
1425 		 */
1426 		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1427 		    insn[1].code == 0)
1428 			memcpy(aux, insn, sizeof(aux));
1429 
1430 		rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1431 						clone->aux->verifier_zext);
1432 		if (!rewritten)
1433 			continue;
1434 
1435 		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1436 		if (IS_ERR(tmp)) {
1437 			/* Patching may have repointed aux->prog during
1438 			 * realloc from the original one, so we need to
1439 			 * fix it up here on error.
1440 			 */
1441 			bpf_jit_prog_release_other(prog, clone);
1442 			return tmp;
1443 		}
1444 
1445 		clone = tmp;
1446 		insn_delta = rewritten - 1;
1447 
1448 		/* Walk new program and skip insns we just inserted. */
1449 		insn = clone->insnsi + i + insn_delta;
1450 		insn_cnt += insn_delta;
1451 		i        += insn_delta;
1452 	}
1453 
1454 	clone->blinded = 1;
1455 	return clone;
1456 }
1457 #endif /* CONFIG_BPF_JIT */
1458 
1459 /* Base function for offset calculation. Needs to go into .text section,
1460  * therefore keeping it non-static as well; will also be used by JITs
1461  * anyway later on, so do not let the compiler omit it. This also needs
1462  * to go into kallsyms for correlation from e.g. bpftool, so naming
1463  * must not change.
1464  */
1465 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1466 {
1467 	return 0;
1468 }
1469 EXPORT_SYMBOL_GPL(__bpf_call_base);
1470 
1471 /* All UAPI available opcodes. */
1472 #define BPF_INSN_MAP(INSN_2, INSN_3)		\
1473 	/* 32 bit ALU operations. */		\
1474 	/*   Register based. */			\
1475 	INSN_3(ALU, ADD,  X),			\
1476 	INSN_3(ALU, SUB,  X),			\
1477 	INSN_3(ALU, AND,  X),			\
1478 	INSN_3(ALU, OR,   X),			\
1479 	INSN_3(ALU, LSH,  X),			\
1480 	INSN_3(ALU, RSH,  X),			\
1481 	INSN_3(ALU, XOR,  X),			\
1482 	INSN_3(ALU, MUL,  X),			\
1483 	INSN_3(ALU, MOV,  X),			\
1484 	INSN_3(ALU, ARSH, X),			\
1485 	INSN_3(ALU, DIV,  X),			\
1486 	INSN_3(ALU, MOD,  X),			\
1487 	INSN_2(ALU, NEG),			\
1488 	INSN_3(ALU, END, TO_BE),		\
1489 	INSN_3(ALU, END, TO_LE),		\
1490 	/*   Immediate based. */		\
1491 	INSN_3(ALU, ADD,  K),			\
1492 	INSN_3(ALU, SUB,  K),			\
1493 	INSN_3(ALU, AND,  K),			\
1494 	INSN_3(ALU, OR,   K),			\
1495 	INSN_3(ALU, LSH,  K),			\
1496 	INSN_3(ALU, RSH,  K),			\
1497 	INSN_3(ALU, XOR,  K),			\
1498 	INSN_3(ALU, MUL,  K),			\
1499 	INSN_3(ALU, MOV,  K),			\
1500 	INSN_3(ALU, ARSH, K),			\
1501 	INSN_3(ALU, DIV,  K),			\
1502 	INSN_3(ALU, MOD,  K),			\
1503 	/* 64 bit ALU operations. */		\
1504 	/*   Register based. */			\
1505 	INSN_3(ALU64, ADD,  X),			\
1506 	INSN_3(ALU64, SUB,  X),			\
1507 	INSN_3(ALU64, AND,  X),			\
1508 	INSN_3(ALU64, OR,   X),			\
1509 	INSN_3(ALU64, LSH,  X),			\
1510 	INSN_3(ALU64, RSH,  X),			\
1511 	INSN_3(ALU64, XOR,  X),			\
1512 	INSN_3(ALU64, MUL,  X),			\
1513 	INSN_3(ALU64, MOV,  X),			\
1514 	INSN_3(ALU64, ARSH, X),			\
1515 	INSN_3(ALU64, DIV,  X),			\
1516 	INSN_3(ALU64, MOD,  X),			\
1517 	INSN_2(ALU64, NEG),			\
1518 	/*   Immediate based. */		\
1519 	INSN_3(ALU64, ADD,  K),			\
1520 	INSN_3(ALU64, SUB,  K),			\
1521 	INSN_3(ALU64, AND,  K),			\
1522 	INSN_3(ALU64, OR,   K),			\
1523 	INSN_3(ALU64, LSH,  K),			\
1524 	INSN_3(ALU64, RSH,  K),			\
1525 	INSN_3(ALU64, XOR,  K),			\
1526 	INSN_3(ALU64, MUL,  K),			\
1527 	INSN_3(ALU64, MOV,  K),			\
1528 	INSN_3(ALU64, ARSH, K),			\
1529 	INSN_3(ALU64, DIV,  K),			\
1530 	INSN_3(ALU64, MOD,  K),			\
1531 	/* Call instruction. */			\
1532 	INSN_2(JMP, CALL),			\
1533 	/* Exit instruction. */			\
1534 	INSN_2(JMP, EXIT),			\
1535 	/* 32-bit Jump instructions. */		\
1536 	/*   Register based. */			\
1537 	INSN_3(JMP32, JEQ,  X),			\
1538 	INSN_3(JMP32, JNE,  X),			\
1539 	INSN_3(JMP32, JGT,  X),			\
1540 	INSN_3(JMP32, JLT,  X),			\
1541 	INSN_3(JMP32, JGE,  X),			\
1542 	INSN_3(JMP32, JLE,  X),			\
1543 	INSN_3(JMP32, JSGT, X),			\
1544 	INSN_3(JMP32, JSLT, X),			\
1545 	INSN_3(JMP32, JSGE, X),			\
1546 	INSN_3(JMP32, JSLE, X),			\
1547 	INSN_3(JMP32, JSET, X),			\
1548 	/*   Immediate based. */		\
1549 	INSN_3(JMP32, JEQ,  K),			\
1550 	INSN_3(JMP32, JNE,  K),			\
1551 	INSN_3(JMP32, JGT,  K),			\
1552 	INSN_3(JMP32, JLT,  K),			\
1553 	INSN_3(JMP32, JGE,  K),			\
1554 	INSN_3(JMP32, JLE,  K),			\
1555 	INSN_3(JMP32, JSGT, K),			\
1556 	INSN_3(JMP32, JSLT, K),			\
1557 	INSN_3(JMP32, JSGE, K),			\
1558 	INSN_3(JMP32, JSLE, K),			\
1559 	INSN_3(JMP32, JSET, K),			\
1560 	/* Jump instructions. */		\
1561 	/*   Register based. */			\
1562 	INSN_3(JMP, JEQ,  X),			\
1563 	INSN_3(JMP, JNE,  X),			\
1564 	INSN_3(JMP, JGT,  X),			\
1565 	INSN_3(JMP, JLT,  X),			\
1566 	INSN_3(JMP, JGE,  X),			\
1567 	INSN_3(JMP, JLE,  X),			\
1568 	INSN_3(JMP, JSGT, X),			\
1569 	INSN_3(JMP, JSLT, X),			\
1570 	INSN_3(JMP, JSGE, X),			\
1571 	INSN_3(JMP, JSLE, X),			\
1572 	INSN_3(JMP, JSET, X),			\
1573 	/*   Immediate based. */		\
1574 	INSN_3(JMP, JEQ,  K),			\
1575 	INSN_3(JMP, JNE,  K),			\
1576 	INSN_3(JMP, JGT,  K),			\
1577 	INSN_3(JMP, JLT,  K),			\
1578 	INSN_3(JMP, JGE,  K),			\
1579 	INSN_3(JMP, JLE,  K),			\
1580 	INSN_3(JMP, JSGT, K),			\
1581 	INSN_3(JMP, JSLT, K),			\
1582 	INSN_3(JMP, JSGE, K),			\
1583 	INSN_3(JMP, JSLE, K),			\
1584 	INSN_3(JMP, JSET, K),			\
1585 	INSN_2(JMP, JA),			\
1586 	/* Store instructions. */		\
1587 	/*   Register based. */			\
1588 	INSN_3(STX, MEM,  B),			\
1589 	INSN_3(STX, MEM,  H),			\
1590 	INSN_3(STX, MEM,  W),			\
1591 	INSN_3(STX, MEM,  DW),			\
1592 	INSN_3(STX, ATOMIC, W),			\
1593 	INSN_3(STX, ATOMIC, DW),		\
1594 	/*   Immediate based. */		\
1595 	INSN_3(ST, MEM, B),			\
1596 	INSN_3(ST, MEM, H),			\
1597 	INSN_3(ST, MEM, W),			\
1598 	INSN_3(ST, MEM, DW),			\
1599 	/* Load instructions. */		\
1600 	/*   Register based. */			\
1601 	INSN_3(LDX, MEM, B),			\
1602 	INSN_3(LDX, MEM, H),			\
1603 	INSN_3(LDX, MEM, W),			\
1604 	INSN_3(LDX, MEM, DW),			\
1605 	/*   Immediate based. */		\
1606 	INSN_3(LD, IMM, DW)
1607 
1608 bool bpf_opcode_in_insntable(u8 code)
1609 {
1610 #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
1611 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1612 	static const bool public_insntable[256] = {
1613 		[0 ... 255] = false,
1614 		/* Now overwrite non-defaults ... */
1615 		BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1616 		/* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1617 		[BPF_LD | BPF_ABS | BPF_B] = true,
1618 		[BPF_LD | BPF_ABS | BPF_H] = true,
1619 		[BPF_LD | BPF_ABS | BPF_W] = true,
1620 		[BPF_LD | BPF_IND | BPF_B] = true,
1621 		[BPF_LD | BPF_IND | BPF_H] = true,
1622 		[BPF_LD | BPF_IND | BPF_W] = true,
1623 	};
1624 #undef BPF_INSN_3_TBL
1625 #undef BPF_INSN_2_TBL
1626 	return public_insntable[code];
1627 }
1628 
1629 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1630 u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
1631 {
1632 	memset(dst, 0, size);
1633 	return -EFAULT;
1634 }
1635 
1636 /**
1637  *	___bpf_prog_run - run eBPF program on a given context
1638  *	@regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1639  *	@insn: is the array of eBPF instructions
1640  *
1641  * Decode and execute eBPF instructions.
1642  *
1643  * Return: whatever value is in %BPF_R0 at program exit
1644  */
1645 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1646 {
1647 #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
1648 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1649 	static const void * const jumptable[256] __annotate_jump_table = {
1650 		[0 ... 255] = &&default_label,
1651 		/* Now overwrite non-defaults ... */
1652 		BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1653 		/* Non-UAPI available opcodes. */
1654 		[BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1655 		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1656 		[BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
1657 		[BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1658 		[BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1659 		[BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1660 		[BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1661 	};
1662 #undef BPF_INSN_3_LBL
1663 #undef BPF_INSN_2_LBL
1664 	u32 tail_call_cnt = 0;
1665 
1666 #define CONT	 ({ insn++; goto select_insn; })
1667 #define CONT_JMP ({ insn++; goto select_insn; })
1668 
1669 select_insn:
1670 	goto *jumptable[insn->code];
1671 
1672 	/* Explicitly mask the register-based shift amounts with 63 or 31
1673 	 * to avoid undefined behavior. Normally this won't affect the
1674 	 * generated code, for example, in case of native 64 bit archs such
1675 	 * as x86-64 or arm64, the compiler is optimizing the AND away for
1676 	 * the interpreter. In case of JITs, each of the JIT backends compiles
1677 	 * the BPF shift operations to machine instructions which produce
1678 	 * implementation-defined results in such a case; the resulting
1679 	 * contents of the register may be arbitrary, but program behaviour
1680 	 * as a whole remains defined. In other words, in case of JIT backends,
1681 	 * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1682 	 */
1683 	/* ALU (shifts) */
1684 #define SHT(OPCODE, OP)					\
1685 	ALU64_##OPCODE##_X:				\
1686 		DST = DST OP (SRC & 63);		\
1687 		CONT;					\
1688 	ALU_##OPCODE##_X:				\
1689 		DST = (u32) DST OP ((u32) SRC & 31);	\
1690 		CONT;					\
1691 	ALU64_##OPCODE##_K:				\
1692 		DST = DST OP IMM;			\
1693 		CONT;					\
1694 	ALU_##OPCODE##_K:				\
1695 		DST = (u32) DST OP (u32) IMM;		\
1696 		CONT;
1697 	/* ALU (rest) */
1698 #define ALU(OPCODE, OP)					\
1699 	ALU64_##OPCODE##_X:				\
1700 		DST = DST OP SRC;			\
1701 		CONT;					\
1702 	ALU_##OPCODE##_X:				\
1703 		DST = (u32) DST OP (u32) SRC;		\
1704 		CONT;					\
1705 	ALU64_##OPCODE##_K:				\
1706 		DST = DST OP IMM;			\
1707 		CONT;					\
1708 	ALU_##OPCODE##_K:				\
1709 		DST = (u32) DST OP (u32) IMM;		\
1710 		CONT;
1711 	ALU(ADD,  +)
1712 	ALU(SUB,  -)
1713 	ALU(AND,  &)
1714 	ALU(OR,   |)
1715 	ALU(XOR,  ^)
1716 	ALU(MUL,  *)
1717 	SHT(LSH, <<)
1718 	SHT(RSH, >>)
1719 #undef SHT
1720 #undef ALU
1721 	ALU_NEG:
1722 		DST = (u32) -DST;
1723 		CONT;
1724 	ALU64_NEG:
1725 		DST = -DST;
1726 		CONT;
1727 	ALU_MOV_X:
1728 		DST = (u32) SRC;
1729 		CONT;
1730 	ALU_MOV_K:
1731 		DST = (u32) IMM;
1732 		CONT;
1733 	ALU64_MOV_X:
1734 		DST = SRC;
1735 		CONT;
1736 	ALU64_MOV_K:
1737 		DST = IMM;
1738 		CONT;
1739 	LD_IMM_DW:
1740 		DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1741 		insn++;
1742 		CONT;
1743 	ALU_ARSH_X:
1744 		DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1745 		CONT;
1746 	ALU_ARSH_K:
1747 		DST = (u64) (u32) (((s32) DST) >> IMM);
1748 		CONT;
1749 	ALU64_ARSH_X:
1750 		(*(s64 *) &DST) >>= (SRC & 63);
1751 		CONT;
1752 	ALU64_ARSH_K:
1753 		(*(s64 *) &DST) >>= IMM;
1754 		CONT;
1755 	ALU64_MOD_X:
1756 		div64_u64_rem(DST, SRC, &AX);
1757 		DST = AX;
1758 		CONT;
1759 	ALU_MOD_X:
1760 		AX = (u32) DST;
1761 		DST = do_div(AX, (u32) SRC);
1762 		CONT;
1763 	ALU64_MOD_K:
1764 		div64_u64_rem(DST, IMM, &AX);
1765 		DST = AX;
1766 		CONT;
1767 	ALU_MOD_K:
1768 		AX = (u32) DST;
1769 		DST = do_div(AX, (u32) IMM);
1770 		CONT;
1771 	ALU64_DIV_X:
1772 		DST = div64_u64(DST, SRC);
1773 		CONT;
1774 	ALU_DIV_X:
1775 		AX = (u32) DST;
1776 		do_div(AX, (u32) SRC);
1777 		DST = (u32) AX;
1778 		CONT;
1779 	ALU64_DIV_K:
1780 		DST = div64_u64(DST, IMM);
1781 		CONT;
1782 	ALU_DIV_K:
1783 		AX = (u32) DST;
1784 		do_div(AX, (u32) IMM);
1785 		DST = (u32) AX;
1786 		CONT;
1787 	ALU_END_TO_BE:
1788 		switch (IMM) {
1789 		case 16:
1790 			DST = (__force u16) cpu_to_be16(DST);
1791 			break;
1792 		case 32:
1793 			DST = (__force u32) cpu_to_be32(DST);
1794 			break;
1795 		case 64:
1796 			DST = (__force u64) cpu_to_be64(DST);
1797 			break;
1798 		}
1799 		CONT;
1800 	ALU_END_TO_LE:
1801 		switch (IMM) {
1802 		case 16:
1803 			DST = (__force u16) cpu_to_le16(DST);
1804 			break;
1805 		case 32:
1806 			DST = (__force u32) cpu_to_le32(DST);
1807 			break;
1808 		case 64:
1809 			DST = (__force u64) cpu_to_le64(DST);
1810 			break;
1811 		}
1812 		CONT;
1813 
1814 	/* CALL */
1815 	JMP_CALL:
1816 		/* Function call scratches BPF_R1-BPF_R5 registers,
1817 		 * preserves BPF_R6-BPF_R9, and stores return value
1818 		 * into BPF_R0.
1819 		 */
1820 		BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1821 						       BPF_R4, BPF_R5);
1822 		CONT;
1823 
1824 	JMP_CALL_ARGS:
1825 		BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
1826 							    BPF_R3, BPF_R4,
1827 							    BPF_R5,
1828 							    insn + insn->off + 1);
1829 		CONT;
1830 
1831 	JMP_TAIL_CALL: {
1832 		struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1833 		struct bpf_array *array = container_of(map, struct bpf_array, map);
1834 		struct bpf_prog *prog;
1835 		u32 index = BPF_R3;
1836 
1837 		if (unlikely(index >= array->map.max_entries))
1838 			goto out;
1839 
1840 		if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
1841 			goto out;
1842 
1843 		tail_call_cnt++;
1844 
1845 		prog = READ_ONCE(array->ptrs[index]);
1846 		if (!prog)
1847 			goto out;
1848 
1849 		/* ARG1 at this point is guaranteed to point to CTX from
1850 		 * the verifier side due to the fact that the tail call is
1851 		 * handled like a helper, that is, bpf_tail_call_proto,
1852 		 * where arg1_type is ARG_PTR_TO_CTX.
1853 		 */
1854 		insn = prog->insnsi;
1855 		goto select_insn;
1856 out:
1857 		CONT;
1858 	}
1859 	JMP_JA:
1860 		insn += insn->off;
1861 		CONT;
1862 	JMP_EXIT:
1863 		return BPF_R0;
1864 	/* JMP */
1865 #define COND_JMP(SIGN, OPCODE, CMP_OP)				\
1866 	JMP_##OPCODE##_X:					\
1867 		if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {	\
1868 			insn += insn->off;			\
1869 			CONT_JMP;				\
1870 		}						\
1871 		CONT;						\
1872 	JMP32_##OPCODE##_X:					\
1873 		if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {	\
1874 			insn += insn->off;			\
1875 			CONT_JMP;				\
1876 		}						\
1877 		CONT;						\
1878 	JMP_##OPCODE##_K:					\
1879 		if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {	\
1880 			insn += insn->off;			\
1881 			CONT_JMP;				\
1882 		}						\
1883 		CONT;						\
1884 	JMP32_##OPCODE##_K:					\
1885 		if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {	\
1886 			insn += insn->off;			\
1887 			CONT_JMP;				\
1888 		}						\
1889 		CONT;
1890 	COND_JMP(u, JEQ, ==)
1891 	COND_JMP(u, JNE, !=)
1892 	COND_JMP(u, JGT, >)
1893 	COND_JMP(u, JLT, <)
1894 	COND_JMP(u, JGE, >=)
1895 	COND_JMP(u, JLE, <=)
1896 	COND_JMP(u, JSET, &)
1897 	COND_JMP(s, JSGT, >)
1898 	COND_JMP(s, JSLT, <)
1899 	COND_JMP(s, JSGE, >=)
1900 	COND_JMP(s, JSLE, <=)
1901 #undef COND_JMP
1902 	/* ST, STX and LDX*/
1903 	ST_NOSPEC:
1904 		/* Speculation barrier for mitigating Speculative Store Bypass.
1905 		 * In case of arm64, we rely on the firmware mitigation as
1906 		 * controlled via the ssbd kernel parameter. Whenever the
1907 		 * mitigation is enabled, it works for all of the kernel code
1908 		 * with no need to provide any additional instructions here.
1909 		 * In case of x86, we use 'lfence' insn for mitigation. We
1910 		 * reuse preexisting logic from Spectre v1 mitigation that
1911 		 * happens to produce the required code on x86 for v4 as well.
1912 		 */
1913 #ifdef CONFIG_X86
1914 		barrier_nospec();
1915 #endif
1916 		CONT;
1917 #define LDST(SIZEOP, SIZE)						\
1918 	STX_MEM_##SIZEOP:						\
1919 		*(SIZE *)(unsigned long) (DST + insn->off) = SRC;	\
1920 		CONT;							\
1921 	ST_MEM_##SIZEOP:						\
1922 		*(SIZE *)(unsigned long) (DST + insn->off) = IMM;	\
1923 		CONT;							\
1924 	LDX_MEM_##SIZEOP:						\
1925 		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
1926 		CONT;							\
1927 	LDX_PROBE_MEM_##SIZEOP:						\
1928 		bpf_probe_read_kernel(&DST, sizeof(SIZE),		\
1929 				      (const void *)(long) (SRC + insn->off));	\
1930 		DST = *((SIZE *)&DST);					\
1931 		CONT;
1932 
1933 	LDST(B,   u8)
1934 	LDST(H,  u16)
1935 	LDST(W,  u32)
1936 	LDST(DW, u64)
1937 #undef LDST
1938 
1939 #define ATOMIC_ALU_OP(BOP, KOP)						\
1940 		case BOP:						\
1941 			if (BPF_SIZE(insn->code) == BPF_W)		\
1942 				atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
1943 					     (DST + insn->off));	\
1944 			else						\
1945 				atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
1946 					       (DST + insn->off));	\
1947 			break;						\
1948 		case BOP | BPF_FETCH:					\
1949 			if (BPF_SIZE(insn->code) == BPF_W)		\
1950 				SRC = (u32) atomic_fetch_##KOP(		\
1951 					(u32) SRC,			\
1952 					(atomic_t *)(unsigned long) (DST + insn->off)); \
1953 			else						\
1954 				SRC = (u64) atomic64_fetch_##KOP(	\
1955 					(u64) SRC,			\
1956 					(atomic64_t *)(unsigned long) (DST + insn->off)); \
1957 			break;
1958 
1959 	STX_ATOMIC_DW:
1960 	STX_ATOMIC_W:
1961 		switch (IMM) {
1962 		ATOMIC_ALU_OP(BPF_ADD, add)
1963 		ATOMIC_ALU_OP(BPF_AND, and)
1964 		ATOMIC_ALU_OP(BPF_OR, or)
1965 		ATOMIC_ALU_OP(BPF_XOR, xor)
1966 #undef ATOMIC_ALU_OP
1967 
1968 		case BPF_XCHG:
1969 			if (BPF_SIZE(insn->code) == BPF_W)
1970 				SRC = (u32) atomic_xchg(
1971 					(atomic_t *)(unsigned long) (DST + insn->off),
1972 					(u32) SRC);
1973 			else
1974 				SRC = (u64) atomic64_xchg(
1975 					(atomic64_t *)(unsigned long) (DST + insn->off),
1976 					(u64) SRC);
1977 			break;
1978 		case BPF_CMPXCHG:
1979 			if (BPF_SIZE(insn->code) == BPF_W)
1980 				BPF_R0 = (u32) atomic_cmpxchg(
1981 					(atomic_t *)(unsigned long) (DST + insn->off),
1982 					(u32) BPF_R0, (u32) SRC);
1983 			else
1984 				BPF_R0 = (u64) atomic64_cmpxchg(
1985 					(atomic64_t *)(unsigned long) (DST + insn->off),
1986 					(u64) BPF_R0, (u64) SRC);
1987 			break;
1988 
1989 		default:
1990 			goto default_label;
1991 		}
1992 		CONT;
1993 
1994 	default_label:
1995 		/* If we ever reach this, we have a bug somewhere. Die hard here
1996 		 * instead of just returning 0; we could be somewhere in a subprog,
1997 		 * so execution could continue otherwise which we do /not/ want.
1998 		 *
1999 		 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2000 		 */
2001 		pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2002 			insn->code, insn->imm);
2003 		BUG_ON(1);
2004 		return 0;
2005 }
2006 
2007 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2008 #define DEFINE_BPF_PROG_RUN(stack_size) \
2009 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2010 { \
2011 	u64 stack[stack_size / sizeof(u64)]; \
2012 	u64 regs[MAX_BPF_EXT_REG] = {}; \
2013 \
2014 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2015 	ARG1 = (u64) (unsigned long) ctx; \
2016 	return ___bpf_prog_run(regs, insn); \
2017 }
2018 
2019 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2020 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2021 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2022 				      const struct bpf_insn *insn) \
2023 { \
2024 	u64 stack[stack_size / sizeof(u64)]; \
2025 	u64 regs[MAX_BPF_EXT_REG]; \
2026 \
2027 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2028 	BPF_R1 = r1; \
2029 	BPF_R2 = r2; \
2030 	BPF_R3 = r3; \
2031 	BPF_R4 = r4; \
2032 	BPF_R5 = r5; \
2033 	return ___bpf_prog_run(regs, insn); \
2034 }
2035 
2036 #define EVAL1(FN, X) FN(X)
2037 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2038 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2039 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2040 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2041 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2042 
2043 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2044 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2045 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2046 
2047 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2048 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2049 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2050 
2051 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2052 
2053 static unsigned int (*interpreters[])(const void *ctx,
2054 				      const struct bpf_insn *insn) = {
2055 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2056 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2057 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2058 };
2059 #undef PROG_NAME_LIST
2060 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2061 static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2062 				  const struct bpf_insn *insn) = {
2063 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2064 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2065 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2066 };
2067 #undef PROG_NAME_LIST
2068 
2069 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2070 {
2071 	stack_depth = max_t(u32, stack_depth, 1);
2072 	insn->off = (s16) insn->imm;
2073 	insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
2074 		__bpf_call_base_args;
2075 	insn->code = BPF_JMP | BPF_CALL_ARGS;
2076 }
2077 
2078 #else
2079 static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2080 					 const struct bpf_insn *insn)
2081 {
2082 	/* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2083 	 * is not working properly, so warn about it!
2084 	 */
2085 	WARN_ON_ONCE(1);
2086 	return 0;
2087 }
2088 #endif
2089 
2090 bool bpf_prog_map_compatible(struct bpf_map *map,
2091 			     const struct bpf_prog *fp)
2092 {
2093 	enum bpf_prog_type prog_type = resolve_prog_type(fp);
2094 	bool ret;
2095 
2096 	if (fp->kprobe_override)
2097 		return false;
2098 
2099 	spin_lock(&map->owner.lock);
2100 	if (!map->owner.type) {
2101 		/* There's no owner yet where we could check for
2102 		 * compatibility.
2103 		 */
2104 		map->owner.type  = prog_type;
2105 		map->owner.jited = fp->jited;
2106 		map->owner.xdp_has_frags = fp->aux->xdp_has_frags;
2107 		ret = true;
2108 	} else {
2109 		ret = map->owner.type  == prog_type &&
2110 		      map->owner.jited == fp->jited &&
2111 		      map->owner.xdp_has_frags == fp->aux->xdp_has_frags;
2112 	}
2113 	spin_unlock(&map->owner.lock);
2114 
2115 	return ret;
2116 }
2117 
2118 static int bpf_check_tail_call(const struct bpf_prog *fp)
2119 {
2120 	struct bpf_prog_aux *aux = fp->aux;
2121 	int i, ret = 0;
2122 
2123 	mutex_lock(&aux->used_maps_mutex);
2124 	for (i = 0; i < aux->used_map_cnt; i++) {
2125 		struct bpf_map *map = aux->used_maps[i];
2126 
2127 		if (!map_type_contains_progs(map))
2128 			continue;
2129 
2130 		if (!bpf_prog_map_compatible(map, fp)) {
2131 			ret = -EINVAL;
2132 			goto out;
2133 		}
2134 	}
2135 
2136 out:
2137 	mutex_unlock(&aux->used_maps_mutex);
2138 	return ret;
2139 }
2140 
2141 static void bpf_prog_select_func(struct bpf_prog *fp)
2142 {
2143 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
2144 	u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2145 
2146 	fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
2147 #else
2148 	fp->bpf_func = __bpf_prog_ret0_warn;
2149 #endif
2150 }
2151 
2152 /**
2153  *	bpf_prog_select_runtime - select exec runtime for BPF program
2154  *	@fp: bpf_prog populated with BPF program
2155  *	@err: pointer to error variable
2156  *
2157  * Try to JIT eBPF program, if JIT is not available, use interpreter.
2158  * The BPF program will be executed via bpf_prog_run() function.
2159  *
2160  * Return: the &fp argument along with &err set to 0 for success or
2161  * a negative errno code on failure
2162  */
2163 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2164 {
2165 	/* In case of BPF to BPF calls, verifier did all the prep
2166 	 * work with regards to JITing, etc.
2167 	 */
2168 	bool jit_needed = false;
2169 
2170 	if (fp->bpf_func)
2171 		goto finalize;
2172 
2173 	if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
2174 	    bpf_prog_has_kfunc_call(fp))
2175 		jit_needed = true;
2176 
2177 	bpf_prog_select_func(fp);
2178 
2179 	/* eBPF JITs can rewrite the program in case constant
2180 	 * blinding is active. However, in case of error during
2181 	 * blinding, bpf_int_jit_compile() must always return a
2182 	 * valid program, which in this case would simply not
2183 	 * be JITed, but falls back to the interpreter.
2184 	 */
2185 	if (!bpf_prog_is_dev_bound(fp->aux)) {
2186 		*err = bpf_prog_alloc_jited_linfo(fp);
2187 		if (*err)
2188 			return fp;
2189 
2190 		fp = bpf_int_jit_compile(fp);
2191 		bpf_prog_jit_attempt_done(fp);
2192 		if (!fp->jited && jit_needed) {
2193 			*err = -ENOTSUPP;
2194 			return fp;
2195 		}
2196 	} else {
2197 		*err = bpf_prog_offload_compile(fp);
2198 		if (*err)
2199 			return fp;
2200 	}
2201 
2202 finalize:
2203 	bpf_prog_lock_ro(fp);
2204 
2205 	/* The tail call compatibility check can only be done at
2206 	 * this late stage as we need to determine, if we deal
2207 	 * with JITed or non JITed program concatenations and not
2208 	 * all eBPF JITs might immediately support all features.
2209 	 */
2210 	*err = bpf_check_tail_call(fp);
2211 
2212 	return fp;
2213 }
2214 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2215 
2216 static unsigned int __bpf_prog_ret1(const void *ctx,
2217 				    const struct bpf_insn *insn)
2218 {
2219 	return 1;
2220 }
2221 
2222 static struct bpf_prog_dummy {
2223 	struct bpf_prog prog;
2224 } dummy_bpf_prog = {
2225 	.prog = {
2226 		.bpf_func = __bpf_prog_ret1,
2227 	},
2228 };
2229 
2230 struct bpf_empty_prog_array bpf_empty_prog_array = {
2231 	.null_prog = NULL,
2232 };
2233 EXPORT_SYMBOL(bpf_empty_prog_array);
2234 
2235 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2236 {
2237 	if (prog_cnt)
2238 		return kzalloc(sizeof(struct bpf_prog_array) +
2239 			       sizeof(struct bpf_prog_array_item) *
2240 			       (prog_cnt + 1),
2241 			       flags);
2242 
2243 	return &bpf_empty_prog_array.hdr;
2244 }
2245 
2246 void bpf_prog_array_free(struct bpf_prog_array *progs)
2247 {
2248 	if (!progs || progs == &bpf_empty_prog_array.hdr)
2249 		return;
2250 	kfree_rcu(progs, rcu);
2251 }
2252 
2253 static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2254 {
2255 	struct bpf_prog_array *progs;
2256 
2257 	/* If RCU Tasks Trace grace period implies RCU grace period, there is
2258 	 * no need to call kfree_rcu(), just call kfree() directly.
2259 	 */
2260 	progs = container_of(rcu, struct bpf_prog_array, rcu);
2261 	if (rcu_trace_implies_rcu_gp())
2262 		kfree(progs);
2263 	else
2264 		kfree_rcu(progs, rcu);
2265 }
2266 
2267 void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2268 {
2269 	if (!progs || progs == &bpf_empty_prog_array.hdr)
2270 		return;
2271 	call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2272 }
2273 
2274 int bpf_prog_array_length(struct bpf_prog_array *array)
2275 {
2276 	struct bpf_prog_array_item *item;
2277 	u32 cnt = 0;
2278 
2279 	for (item = array->items; item->prog; item++)
2280 		if (item->prog != &dummy_bpf_prog.prog)
2281 			cnt++;
2282 	return cnt;
2283 }
2284 
2285 bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2286 {
2287 	struct bpf_prog_array_item *item;
2288 
2289 	for (item = array->items; item->prog; item++)
2290 		if (item->prog != &dummy_bpf_prog.prog)
2291 			return false;
2292 	return true;
2293 }
2294 
2295 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2296 				     u32 *prog_ids,
2297 				     u32 request_cnt)
2298 {
2299 	struct bpf_prog_array_item *item;
2300 	int i = 0;
2301 
2302 	for (item = array->items; item->prog; item++) {
2303 		if (item->prog == &dummy_bpf_prog.prog)
2304 			continue;
2305 		prog_ids[i] = item->prog->aux->id;
2306 		if (++i == request_cnt) {
2307 			item++;
2308 			break;
2309 		}
2310 	}
2311 
2312 	return !!(item->prog);
2313 }
2314 
2315 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2316 				__u32 __user *prog_ids, u32 cnt)
2317 {
2318 	unsigned long err = 0;
2319 	bool nospc;
2320 	u32 *ids;
2321 
2322 	/* users of this function are doing:
2323 	 * cnt = bpf_prog_array_length();
2324 	 * if (cnt > 0)
2325 	 *     bpf_prog_array_copy_to_user(..., cnt);
2326 	 * so below kcalloc doesn't need extra cnt > 0 check.
2327 	 */
2328 	ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2329 	if (!ids)
2330 		return -ENOMEM;
2331 	nospc = bpf_prog_array_copy_core(array, ids, cnt);
2332 	err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2333 	kfree(ids);
2334 	if (err)
2335 		return -EFAULT;
2336 	if (nospc)
2337 		return -ENOSPC;
2338 	return 0;
2339 }
2340 
2341 void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2342 				struct bpf_prog *old_prog)
2343 {
2344 	struct bpf_prog_array_item *item;
2345 
2346 	for (item = array->items; item->prog; item++)
2347 		if (item->prog == old_prog) {
2348 			WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2349 			break;
2350 		}
2351 }
2352 
2353 /**
2354  * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2355  *                                   index into the program array with
2356  *                                   a dummy no-op program.
2357  * @array: a bpf_prog_array
2358  * @index: the index of the program to replace
2359  *
2360  * Skips over dummy programs, by not counting them, when calculating
2361  * the position of the program to replace.
2362  *
2363  * Return:
2364  * * 0		- Success
2365  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2366  * * -ENOENT	- Index out of range
2367  */
2368 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2369 {
2370 	return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2371 }
2372 
2373 /**
2374  * bpf_prog_array_update_at() - Updates the program at the given index
2375  *                              into the program array.
2376  * @array: a bpf_prog_array
2377  * @index: the index of the program to update
2378  * @prog: the program to insert into the array
2379  *
2380  * Skips over dummy programs, by not counting them, when calculating
2381  * the position of the program to update.
2382  *
2383  * Return:
2384  * * 0		- Success
2385  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2386  * * -ENOENT	- Index out of range
2387  */
2388 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2389 			     struct bpf_prog *prog)
2390 {
2391 	struct bpf_prog_array_item *item;
2392 
2393 	if (unlikely(index < 0))
2394 		return -EINVAL;
2395 
2396 	for (item = array->items; item->prog; item++) {
2397 		if (item->prog == &dummy_bpf_prog.prog)
2398 			continue;
2399 		if (!index) {
2400 			WRITE_ONCE(item->prog, prog);
2401 			return 0;
2402 		}
2403 		index--;
2404 	}
2405 	return -ENOENT;
2406 }
2407 
2408 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2409 			struct bpf_prog *exclude_prog,
2410 			struct bpf_prog *include_prog,
2411 			u64 bpf_cookie,
2412 			struct bpf_prog_array **new_array)
2413 {
2414 	int new_prog_cnt, carry_prog_cnt = 0;
2415 	struct bpf_prog_array_item *existing, *new;
2416 	struct bpf_prog_array *array;
2417 	bool found_exclude = false;
2418 
2419 	/* Figure out how many existing progs we need to carry over to
2420 	 * the new array.
2421 	 */
2422 	if (old_array) {
2423 		existing = old_array->items;
2424 		for (; existing->prog; existing++) {
2425 			if (existing->prog == exclude_prog) {
2426 				found_exclude = true;
2427 				continue;
2428 			}
2429 			if (existing->prog != &dummy_bpf_prog.prog)
2430 				carry_prog_cnt++;
2431 			if (existing->prog == include_prog)
2432 				return -EEXIST;
2433 		}
2434 	}
2435 
2436 	if (exclude_prog && !found_exclude)
2437 		return -ENOENT;
2438 
2439 	/* How many progs (not NULL) will be in the new array? */
2440 	new_prog_cnt = carry_prog_cnt;
2441 	if (include_prog)
2442 		new_prog_cnt += 1;
2443 
2444 	/* Do we have any prog (not NULL) in the new array? */
2445 	if (!new_prog_cnt) {
2446 		*new_array = NULL;
2447 		return 0;
2448 	}
2449 
2450 	/* +1 as the end of prog_array is marked with NULL */
2451 	array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2452 	if (!array)
2453 		return -ENOMEM;
2454 	new = array->items;
2455 
2456 	/* Fill in the new prog array */
2457 	if (carry_prog_cnt) {
2458 		existing = old_array->items;
2459 		for (; existing->prog; existing++) {
2460 			if (existing->prog == exclude_prog ||
2461 			    existing->prog == &dummy_bpf_prog.prog)
2462 				continue;
2463 
2464 			new->prog = existing->prog;
2465 			new->bpf_cookie = existing->bpf_cookie;
2466 			new++;
2467 		}
2468 	}
2469 	if (include_prog) {
2470 		new->prog = include_prog;
2471 		new->bpf_cookie = bpf_cookie;
2472 		new++;
2473 	}
2474 	new->prog = NULL;
2475 	*new_array = array;
2476 	return 0;
2477 }
2478 
2479 int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2480 			     u32 *prog_ids, u32 request_cnt,
2481 			     u32 *prog_cnt)
2482 {
2483 	u32 cnt = 0;
2484 
2485 	if (array)
2486 		cnt = bpf_prog_array_length(array);
2487 
2488 	*prog_cnt = cnt;
2489 
2490 	/* return early if user requested only program count or nothing to copy */
2491 	if (!request_cnt || !cnt)
2492 		return 0;
2493 
2494 	/* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2495 	return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2496 								     : 0;
2497 }
2498 
2499 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2500 			  struct bpf_map **used_maps, u32 len)
2501 {
2502 	struct bpf_map *map;
2503 	u32 i;
2504 
2505 	for (i = 0; i < len; i++) {
2506 		map = used_maps[i];
2507 		if (map->ops->map_poke_untrack)
2508 			map->ops->map_poke_untrack(map, aux);
2509 		bpf_map_put(map);
2510 	}
2511 }
2512 
2513 static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2514 {
2515 	__bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2516 	kfree(aux->used_maps);
2517 }
2518 
2519 void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
2520 			  struct btf_mod_pair *used_btfs, u32 len)
2521 {
2522 #ifdef CONFIG_BPF_SYSCALL
2523 	struct btf_mod_pair *btf_mod;
2524 	u32 i;
2525 
2526 	for (i = 0; i < len; i++) {
2527 		btf_mod = &used_btfs[i];
2528 		if (btf_mod->module)
2529 			module_put(btf_mod->module);
2530 		btf_put(btf_mod->btf);
2531 	}
2532 #endif
2533 }
2534 
2535 static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2536 {
2537 	__bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt);
2538 	kfree(aux->used_btfs);
2539 }
2540 
2541 static void bpf_prog_free_deferred(struct work_struct *work)
2542 {
2543 	struct bpf_prog_aux *aux;
2544 	int i;
2545 
2546 	aux = container_of(work, struct bpf_prog_aux, work);
2547 #ifdef CONFIG_BPF_SYSCALL
2548 	bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
2549 #endif
2550 #ifdef CONFIG_CGROUP_BPF
2551 	if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
2552 		bpf_cgroup_atype_put(aux->cgroup_atype);
2553 #endif
2554 	bpf_free_used_maps(aux);
2555 	bpf_free_used_btfs(aux);
2556 	if (bpf_prog_is_dev_bound(aux))
2557 		bpf_prog_offload_destroy(aux->prog);
2558 #ifdef CONFIG_PERF_EVENTS
2559 	if (aux->prog->has_callchain_buf)
2560 		put_callchain_buffers();
2561 #endif
2562 	if (aux->dst_trampoline)
2563 		bpf_trampoline_put(aux->dst_trampoline);
2564 	for (i = 0; i < aux->func_cnt; i++) {
2565 		/* We can just unlink the subprog poke descriptor table as
2566 		 * it was originally linked to the main program and is also
2567 		 * released along with it.
2568 		 */
2569 		aux->func[i]->aux->poke_tab = NULL;
2570 		bpf_jit_free(aux->func[i]);
2571 	}
2572 	if (aux->func_cnt) {
2573 		kfree(aux->func);
2574 		bpf_prog_unlock_free(aux->prog);
2575 	} else {
2576 		bpf_jit_free(aux->prog);
2577 	}
2578 }
2579 
2580 void bpf_prog_free(struct bpf_prog *fp)
2581 {
2582 	struct bpf_prog_aux *aux = fp->aux;
2583 
2584 	if (aux->dst_prog)
2585 		bpf_prog_put(aux->dst_prog);
2586 	INIT_WORK(&aux->work, bpf_prog_free_deferred);
2587 	schedule_work(&aux->work);
2588 }
2589 EXPORT_SYMBOL_GPL(bpf_prog_free);
2590 
2591 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
2592 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2593 
2594 void bpf_user_rnd_init_once(void)
2595 {
2596 	prandom_init_once(&bpf_user_rnd_state);
2597 }
2598 
2599 BPF_CALL_0(bpf_user_rnd_u32)
2600 {
2601 	/* Should someone ever have the rather unwise idea to use some
2602 	 * of the registers passed into this function, then note that
2603 	 * this function is called from native eBPF and classic-to-eBPF
2604 	 * transformations. Register assignments from both sides are
2605 	 * different, f.e. classic always sets fn(ctx, A, X) here.
2606 	 */
2607 	struct rnd_state *state;
2608 	u32 res;
2609 
2610 	state = &get_cpu_var(bpf_user_rnd_state);
2611 	res = prandom_u32_state(state);
2612 	put_cpu_var(bpf_user_rnd_state);
2613 
2614 	return res;
2615 }
2616 
2617 BPF_CALL_0(bpf_get_raw_cpu_id)
2618 {
2619 	return raw_smp_processor_id();
2620 }
2621 
2622 /* Weak definitions of helper functions in case we don't have bpf syscall. */
2623 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2624 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2625 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2626 const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2627 const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2628 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2629 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
2630 const struct bpf_func_proto bpf_spin_lock_proto __weak;
2631 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2632 const struct bpf_func_proto bpf_jiffies64_proto __weak;
2633 
2634 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2635 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2636 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2637 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2638 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2639 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2640 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
2641 
2642 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2643 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2644 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2645 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2646 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2647 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2648 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2649 const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2650 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2651 const struct bpf_func_proto bpf_set_retval_proto __weak;
2652 const struct bpf_func_proto bpf_get_retval_proto __weak;
2653 
2654 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2655 {
2656 	return NULL;
2657 }
2658 
2659 const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
2660 {
2661 	return NULL;
2662 }
2663 
2664 u64 __weak
2665 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2666 		 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2667 {
2668 	return -ENOTSUPP;
2669 }
2670 EXPORT_SYMBOL_GPL(bpf_event_output);
2671 
2672 /* Always built-in helper functions. */
2673 const struct bpf_func_proto bpf_tail_call_proto = {
2674 	.func		= NULL,
2675 	.gpl_only	= false,
2676 	.ret_type	= RET_VOID,
2677 	.arg1_type	= ARG_PTR_TO_CTX,
2678 	.arg2_type	= ARG_CONST_MAP_PTR,
2679 	.arg3_type	= ARG_ANYTHING,
2680 };
2681 
2682 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2683  * It is encouraged to implement bpf_int_jit_compile() instead, so that
2684  * eBPF and implicitly also cBPF can get JITed!
2685  */
2686 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2687 {
2688 	return prog;
2689 }
2690 
2691 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
2692  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2693  */
2694 void __weak bpf_jit_compile(struct bpf_prog *prog)
2695 {
2696 }
2697 
2698 bool __weak bpf_helper_changes_pkt_data(void *func)
2699 {
2700 	return false;
2701 }
2702 
2703 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2704  * analysis code and wants explicit zero extension inserted by verifier.
2705  * Otherwise, return FALSE.
2706  *
2707  * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2708  * you don't override this. JITs that don't want these extra insns can detect
2709  * them using insn_is_zext.
2710  */
2711 bool __weak bpf_jit_needs_zext(void)
2712 {
2713 	return false;
2714 }
2715 
2716 /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
2717 bool __weak bpf_jit_supports_subprog_tailcalls(void)
2718 {
2719 	return false;
2720 }
2721 
2722 bool __weak bpf_jit_supports_kfunc_call(void)
2723 {
2724 	return false;
2725 }
2726 
2727 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
2728  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
2729  */
2730 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
2731 			 int len)
2732 {
2733 	return -EFAULT;
2734 }
2735 
2736 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
2737 			      void *addr1, void *addr2)
2738 {
2739 	return -ENOTSUPP;
2740 }
2741 
2742 void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
2743 {
2744 	return ERR_PTR(-ENOTSUPP);
2745 }
2746 
2747 int __weak bpf_arch_text_invalidate(void *dst, size_t len)
2748 {
2749 	return -ENOTSUPP;
2750 }
2751 
2752 #ifdef CONFIG_BPF_SYSCALL
2753 static int __init bpf_global_ma_init(void)
2754 {
2755 	int ret;
2756 
2757 	ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
2758 	bpf_global_ma_set = !ret;
2759 	return ret;
2760 }
2761 late_initcall(bpf_global_ma_init);
2762 #endif
2763 
2764 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
2765 EXPORT_SYMBOL(bpf_stats_enabled_key);
2766 
2767 /* All definitions of tracepoints related to BPF. */
2768 #define CREATE_TRACE_POINTS
2769 #include <linux/bpf_trace.h>
2770 
2771 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
2772 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);
2773