xref: /openbmc/linux/kernel/bpf/core.c (revision f4356947)
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/nospec.h>
38 #include <linux/bpf_mem_alloc.h>
39 #include <linux/memcontrol.h>
40 
41 #include <asm/barrier.h>
42 #include <asm/unaligned.h>
43 
44 /* Registers */
45 #define BPF_R0	regs[BPF_REG_0]
46 #define BPF_R1	regs[BPF_REG_1]
47 #define BPF_R2	regs[BPF_REG_2]
48 #define BPF_R3	regs[BPF_REG_3]
49 #define BPF_R4	regs[BPF_REG_4]
50 #define BPF_R5	regs[BPF_REG_5]
51 #define BPF_R6	regs[BPF_REG_6]
52 #define BPF_R7	regs[BPF_REG_7]
53 #define BPF_R8	regs[BPF_REG_8]
54 #define BPF_R9	regs[BPF_REG_9]
55 #define BPF_R10	regs[BPF_REG_10]
56 
57 /* Named registers */
58 #define DST	regs[insn->dst_reg]
59 #define SRC	regs[insn->src_reg]
60 #define FP	regs[BPF_REG_FP]
61 #define AX	regs[BPF_REG_AX]
62 #define ARG1	regs[BPF_REG_ARG1]
63 #define CTX	regs[BPF_REG_CTX]
64 #define IMM	insn->imm
65 
66 struct bpf_mem_alloc bpf_global_ma;
67 bool bpf_global_ma_set;
68 
69 /* No hurry in this branch
70  *
71  * Exported for the bpf jit load helper.
72  */
73 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
74 {
75 	u8 *ptr = NULL;
76 
77 	if (k >= SKF_NET_OFF) {
78 		ptr = skb_network_header(skb) + k - SKF_NET_OFF;
79 	} else if (k >= SKF_LL_OFF) {
80 		if (unlikely(!skb_mac_header_was_set(skb)))
81 			return NULL;
82 		ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
83 	}
84 	if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
85 		return ptr;
86 
87 	return NULL;
88 }
89 
90 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
91 {
92 	gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
93 	struct bpf_prog_aux *aux;
94 	struct bpf_prog *fp;
95 
96 	size = round_up(size, PAGE_SIZE);
97 	fp = __vmalloc(size, gfp_flags);
98 	if (fp == NULL)
99 		return NULL;
100 
101 	aux = kzalloc(sizeof(*aux), bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
102 	if (aux == NULL) {
103 		vfree(fp);
104 		return NULL;
105 	}
106 	fp->active = alloc_percpu_gfp(int, bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
107 	if (!fp->active) {
108 		vfree(fp);
109 		kfree(aux);
110 		return NULL;
111 	}
112 
113 	fp->pages = size / PAGE_SIZE;
114 	fp->aux = aux;
115 	fp->aux->prog = fp;
116 	fp->jit_requested = ebpf_jit_enabled();
117 	fp->blinding_requested = bpf_jit_blinding_enabled(fp);
118 #ifdef CONFIG_CGROUP_BPF
119 	aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID;
120 #endif
121 
122 	INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
123 	mutex_init(&fp->aux->used_maps_mutex);
124 	mutex_init(&fp->aux->dst_mutex);
125 
126 	return fp;
127 }
128 
129 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
130 {
131 	gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
132 	struct bpf_prog *prog;
133 	int cpu;
134 
135 	prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
136 	if (!prog)
137 		return NULL;
138 
139 	prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
140 	if (!prog->stats) {
141 		free_percpu(prog->active);
142 		kfree(prog->aux);
143 		vfree(prog);
144 		return NULL;
145 	}
146 
147 	for_each_possible_cpu(cpu) {
148 		struct bpf_prog_stats *pstats;
149 
150 		pstats = per_cpu_ptr(prog->stats, cpu);
151 		u64_stats_init(&pstats->syncp);
152 	}
153 	return prog;
154 }
155 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
156 
157 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
158 {
159 	if (!prog->aux->nr_linfo || !prog->jit_requested)
160 		return 0;
161 
162 	prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
163 					  sizeof(*prog->aux->jited_linfo),
164 					  bpf_memcg_flags(GFP_KERNEL | __GFP_NOWARN));
165 	if (!prog->aux->jited_linfo)
166 		return -ENOMEM;
167 
168 	return 0;
169 }
170 
171 void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
172 {
173 	if (prog->aux->jited_linfo &&
174 	    (!prog->jited || !prog->aux->jited_linfo[0])) {
175 		kvfree(prog->aux->jited_linfo);
176 		prog->aux->jited_linfo = NULL;
177 	}
178 
179 	kfree(prog->aux->kfunc_tab);
180 	prog->aux->kfunc_tab = NULL;
181 }
182 
183 /* The jit engine is responsible to provide an array
184  * for insn_off to the jited_off mapping (insn_to_jit_off).
185  *
186  * The idx to this array is the insn_off.  Hence, the insn_off
187  * here is relative to the prog itself instead of the main prog.
188  * This array has one entry for each xlated bpf insn.
189  *
190  * jited_off is the byte off to the end of the jited insn.
191  *
192  * Hence, with
193  * insn_start:
194  *      The first bpf insn off of the prog.  The insn off
195  *      here is relative to the main prog.
196  *      e.g. if prog is a subprog, insn_start > 0
197  * linfo_idx:
198  *      The prog's idx to prog->aux->linfo and jited_linfo
199  *
200  * jited_linfo[linfo_idx] = prog->bpf_func
201  *
202  * For i > linfo_idx,
203  *
204  * jited_linfo[i] = prog->bpf_func +
205  *	insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
206  */
207 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
208 			       const u32 *insn_to_jit_off)
209 {
210 	u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
211 	const struct bpf_line_info *linfo;
212 	void **jited_linfo;
213 
214 	if (!prog->aux->jited_linfo)
215 		/* Userspace did not provide linfo */
216 		return;
217 
218 	linfo_idx = prog->aux->linfo_idx;
219 	linfo = &prog->aux->linfo[linfo_idx];
220 	insn_start = linfo[0].insn_off;
221 	insn_end = insn_start + prog->len;
222 
223 	jited_linfo = &prog->aux->jited_linfo[linfo_idx];
224 	jited_linfo[0] = prog->bpf_func;
225 
226 	nr_linfo = prog->aux->nr_linfo - linfo_idx;
227 
228 	for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
229 		/* The verifier ensures that linfo[i].insn_off is
230 		 * strictly increasing
231 		 */
232 		jited_linfo[i] = prog->bpf_func +
233 			insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
234 }
235 
236 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
237 				  gfp_t gfp_extra_flags)
238 {
239 	gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
240 	struct bpf_prog *fp;
241 	u32 pages;
242 
243 	size = round_up(size, PAGE_SIZE);
244 	pages = size / PAGE_SIZE;
245 	if (pages <= fp_old->pages)
246 		return fp_old;
247 
248 	fp = __vmalloc(size, gfp_flags);
249 	if (fp) {
250 		memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
251 		fp->pages = pages;
252 		fp->aux->prog = fp;
253 
254 		/* We keep fp->aux from fp_old around in the new
255 		 * reallocated structure.
256 		 */
257 		fp_old->aux = NULL;
258 		fp_old->stats = NULL;
259 		fp_old->active = NULL;
260 		__bpf_prog_free(fp_old);
261 	}
262 
263 	return fp;
264 }
265 
266 void __bpf_prog_free(struct bpf_prog *fp)
267 {
268 	if (fp->aux) {
269 		mutex_destroy(&fp->aux->used_maps_mutex);
270 		mutex_destroy(&fp->aux->dst_mutex);
271 		kfree(fp->aux->poke_tab);
272 		kfree(fp->aux);
273 	}
274 	free_percpu(fp->stats);
275 	free_percpu(fp->active);
276 	vfree(fp);
277 }
278 
279 int bpf_prog_calc_tag(struct bpf_prog *fp)
280 {
281 	const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
282 	u32 raw_size = bpf_prog_tag_scratch_size(fp);
283 	u32 digest[SHA1_DIGEST_WORDS];
284 	u32 ws[SHA1_WORKSPACE_WORDS];
285 	u32 i, bsize, psize, blocks;
286 	struct bpf_insn *dst;
287 	bool was_ld_map;
288 	u8 *raw, *todo;
289 	__be32 *result;
290 	__be64 *bits;
291 
292 	raw = vmalloc(raw_size);
293 	if (!raw)
294 		return -ENOMEM;
295 
296 	sha1_init(digest);
297 	memset(ws, 0, sizeof(ws));
298 
299 	/* We need to take out the map fd for the digest calculation
300 	 * since they are unstable from user space side.
301 	 */
302 	dst = (void *)raw;
303 	for (i = 0, was_ld_map = false; i < fp->len; i++) {
304 		dst[i] = fp->insnsi[i];
305 		if (!was_ld_map &&
306 		    dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
307 		    (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
308 		     dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
309 			was_ld_map = true;
310 			dst[i].imm = 0;
311 		} else if (was_ld_map &&
312 			   dst[i].code == 0 &&
313 			   dst[i].dst_reg == 0 &&
314 			   dst[i].src_reg == 0 &&
315 			   dst[i].off == 0) {
316 			was_ld_map = false;
317 			dst[i].imm = 0;
318 		} else {
319 			was_ld_map = false;
320 		}
321 	}
322 
323 	psize = bpf_prog_insn_size(fp);
324 	memset(&raw[psize], 0, raw_size - psize);
325 	raw[psize++] = 0x80;
326 
327 	bsize  = round_up(psize, SHA1_BLOCK_SIZE);
328 	blocks = bsize / SHA1_BLOCK_SIZE;
329 	todo   = raw;
330 	if (bsize - psize >= sizeof(__be64)) {
331 		bits = (__be64 *)(todo + bsize - sizeof(__be64));
332 	} else {
333 		bits = (__be64 *)(todo + bsize + bits_offset);
334 		blocks++;
335 	}
336 	*bits = cpu_to_be64((psize - 1) << 3);
337 
338 	while (blocks--) {
339 		sha1_transform(digest, todo, ws);
340 		todo += SHA1_BLOCK_SIZE;
341 	}
342 
343 	result = (__force __be32 *)digest;
344 	for (i = 0; i < SHA1_DIGEST_WORDS; i++)
345 		result[i] = cpu_to_be32(digest[i]);
346 	memcpy(fp->tag, result, sizeof(fp->tag));
347 
348 	vfree(raw);
349 	return 0;
350 }
351 
352 static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
353 				s32 end_new, s32 curr, const bool probe_pass)
354 {
355 	const s64 imm_min = S32_MIN, imm_max = S32_MAX;
356 	s32 delta = end_new - end_old;
357 	s64 imm = insn->imm;
358 
359 	if (curr < pos && curr + imm + 1 >= end_old)
360 		imm += delta;
361 	else if (curr >= end_new && curr + imm + 1 < end_new)
362 		imm -= delta;
363 	if (imm < imm_min || imm > imm_max)
364 		return -ERANGE;
365 	if (!probe_pass)
366 		insn->imm = imm;
367 	return 0;
368 }
369 
370 static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
371 				s32 end_new, s32 curr, const bool probe_pass)
372 {
373 	const s32 off_min = S16_MIN, off_max = S16_MAX;
374 	s32 delta = end_new - end_old;
375 	s32 off = insn->off;
376 
377 	if (curr < pos && curr + off + 1 >= end_old)
378 		off += delta;
379 	else if (curr >= end_new && curr + off + 1 < end_new)
380 		off -= delta;
381 	if (off < off_min || off > off_max)
382 		return -ERANGE;
383 	if (!probe_pass)
384 		insn->off = off;
385 	return 0;
386 }
387 
388 static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
389 			    s32 end_new, const bool probe_pass)
390 {
391 	u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
392 	struct bpf_insn *insn = prog->insnsi;
393 	int ret = 0;
394 
395 	for (i = 0; i < insn_cnt; i++, insn++) {
396 		u8 code;
397 
398 		/* In the probing pass we still operate on the original,
399 		 * unpatched image in order to check overflows before we
400 		 * do any other adjustments. Therefore skip the patchlet.
401 		 */
402 		if (probe_pass && i == pos) {
403 			i = end_new;
404 			insn = prog->insnsi + end_old;
405 		}
406 		if (bpf_pseudo_func(insn)) {
407 			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
408 						   end_new, i, probe_pass);
409 			if (ret)
410 				return ret;
411 			continue;
412 		}
413 		code = insn->code;
414 		if ((BPF_CLASS(code) != BPF_JMP &&
415 		     BPF_CLASS(code) != BPF_JMP32) ||
416 		    BPF_OP(code) == BPF_EXIT)
417 			continue;
418 		/* Adjust offset of jmps if we cross patch boundaries. */
419 		if (BPF_OP(code) == BPF_CALL) {
420 			if (insn->src_reg != BPF_PSEUDO_CALL)
421 				continue;
422 			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
423 						   end_new, i, probe_pass);
424 		} else {
425 			ret = bpf_adj_delta_to_off(insn, pos, end_old,
426 						   end_new, i, probe_pass);
427 		}
428 		if (ret)
429 			break;
430 	}
431 
432 	return ret;
433 }
434 
435 static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
436 {
437 	struct bpf_line_info *linfo;
438 	u32 i, nr_linfo;
439 
440 	nr_linfo = prog->aux->nr_linfo;
441 	if (!nr_linfo || !delta)
442 		return;
443 
444 	linfo = prog->aux->linfo;
445 
446 	for (i = 0; i < nr_linfo; i++)
447 		if (off < linfo[i].insn_off)
448 			break;
449 
450 	/* Push all off < linfo[i].insn_off by delta */
451 	for (; i < nr_linfo; i++)
452 		linfo[i].insn_off += delta;
453 }
454 
455 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
456 				       const struct bpf_insn *patch, u32 len)
457 {
458 	u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
459 	const u32 cnt_max = S16_MAX;
460 	struct bpf_prog *prog_adj;
461 	int err;
462 
463 	/* Since our patchlet doesn't expand the image, we're done. */
464 	if (insn_delta == 0) {
465 		memcpy(prog->insnsi + off, patch, sizeof(*patch));
466 		return prog;
467 	}
468 
469 	insn_adj_cnt = prog->len + insn_delta;
470 
471 	/* Reject anything that would potentially let the insn->off
472 	 * target overflow when we have excessive program expansions.
473 	 * We need to probe here before we do any reallocation where
474 	 * we afterwards may not fail anymore.
475 	 */
476 	if (insn_adj_cnt > cnt_max &&
477 	    (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
478 		return ERR_PTR(err);
479 
480 	/* Several new instructions need to be inserted. Make room
481 	 * for them. Likely, there's no need for a new allocation as
482 	 * last page could have large enough tailroom.
483 	 */
484 	prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
485 				    GFP_USER);
486 	if (!prog_adj)
487 		return ERR_PTR(-ENOMEM);
488 
489 	prog_adj->len = insn_adj_cnt;
490 
491 	/* Patching happens in 3 steps:
492 	 *
493 	 * 1) Move over tail of insnsi from next instruction onwards,
494 	 *    so we can patch the single target insn with one or more
495 	 *    new ones (patching is always from 1 to n insns, n > 0).
496 	 * 2) Inject new instructions at the target location.
497 	 * 3) Adjust branch offsets if necessary.
498 	 */
499 	insn_rest = insn_adj_cnt - off - len;
500 
501 	memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
502 		sizeof(*patch) * insn_rest);
503 	memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
504 
505 	/* We are guaranteed to not fail at this point, otherwise
506 	 * the ship has sailed to reverse to the original state. An
507 	 * overflow cannot happen at this point.
508 	 */
509 	BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
510 
511 	bpf_adj_linfo(prog_adj, off, insn_delta);
512 
513 	return prog_adj;
514 }
515 
516 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
517 {
518 	/* Branch offsets can't overflow when program is shrinking, no need
519 	 * to call bpf_adj_branches(..., true) here
520 	 */
521 	memmove(prog->insnsi + off, prog->insnsi + off + cnt,
522 		sizeof(struct bpf_insn) * (prog->len - off - cnt));
523 	prog->len -= cnt;
524 
525 	return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
526 }
527 
528 static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
529 {
530 	int i;
531 
532 	for (i = 0; i < fp->aux->func_cnt; i++)
533 		bpf_prog_kallsyms_del(fp->aux->func[i]);
534 }
535 
536 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
537 {
538 	bpf_prog_kallsyms_del_subprogs(fp);
539 	bpf_prog_kallsyms_del(fp);
540 }
541 
542 #ifdef CONFIG_BPF_JIT
543 /* All BPF JIT sysctl knobs here. */
544 int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
545 int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
546 int bpf_jit_harden   __read_mostly;
547 long bpf_jit_limit   __read_mostly;
548 long bpf_jit_limit_max __read_mostly;
549 
550 static void
551 bpf_prog_ksym_set_addr(struct bpf_prog *prog)
552 {
553 	WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
554 
555 	prog->aux->ksym.start = (unsigned long) prog->bpf_func;
556 	prog->aux->ksym.end   = prog->aux->ksym.start + prog->jited_len;
557 }
558 
559 static void
560 bpf_prog_ksym_set_name(struct bpf_prog *prog)
561 {
562 	char *sym = prog->aux->ksym.name;
563 	const char *end = sym + KSYM_NAME_LEN;
564 	const struct btf_type *type;
565 	const char *func_name;
566 
567 	BUILD_BUG_ON(sizeof("bpf_prog_") +
568 		     sizeof(prog->tag) * 2 +
569 		     /* name has been null terminated.
570 		      * We should need +1 for the '_' preceding
571 		      * the name.  However, the null character
572 		      * is double counted between the name and the
573 		      * sizeof("bpf_prog_") above, so we omit
574 		      * the +1 here.
575 		      */
576 		     sizeof(prog->aux->name) > KSYM_NAME_LEN);
577 
578 	sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
579 	sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
580 
581 	/* prog->aux->name will be ignored if full btf name is available */
582 	if (prog->aux->func_info_cnt) {
583 		type = btf_type_by_id(prog->aux->btf,
584 				      prog->aux->func_info[prog->aux->func_idx].type_id);
585 		func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
586 		snprintf(sym, (size_t)(end - sym), "_%s", func_name);
587 		return;
588 	}
589 
590 	if (prog->aux->name[0])
591 		snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
592 	else
593 		*sym = 0;
594 }
595 
596 static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
597 {
598 	return container_of(n, struct bpf_ksym, tnode)->start;
599 }
600 
601 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
602 					  struct latch_tree_node *b)
603 {
604 	return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
605 }
606 
607 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
608 {
609 	unsigned long val = (unsigned long)key;
610 	const struct bpf_ksym *ksym;
611 
612 	ksym = container_of(n, struct bpf_ksym, tnode);
613 
614 	if (val < ksym->start)
615 		return -1;
616 	if (val >= ksym->end)
617 		return  1;
618 
619 	return 0;
620 }
621 
622 static const struct latch_tree_ops bpf_tree_ops = {
623 	.less	= bpf_tree_less,
624 	.comp	= bpf_tree_comp,
625 };
626 
627 static DEFINE_SPINLOCK(bpf_lock);
628 static LIST_HEAD(bpf_kallsyms);
629 static struct latch_tree_root bpf_tree __cacheline_aligned;
630 
631 void bpf_ksym_add(struct bpf_ksym *ksym)
632 {
633 	spin_lock_bh(&bpf_lock);
634 	WARN_ON_ONCE(!list_empty(&ksym->lnode));
635 	list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
636 	latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
637 	spin_unlock_bh(&bpf_lock);
638 }
639 
640 static void __bpf_ksym_del(struct bpf_ksym *ksym)
641 {
642 	if (list_empty(&ksym->lnode))
643 		return;
644 
645 	latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
646 	list_del_rcu(&ksym->lnode);
647 }
648 
649 void bpf_ksym_del(struct bpf_ksym *ksym)
650 {
651 	spin_lock_bh(&bpf_lock);
652 	__bpf_ksym_del(ksym);
653 	spin_unlock_bh(&bpf_lock);
654 }
655 
656 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
657 {
658 	return fp->jited && !bpf_prog_was_classic(fp);
659 }
660 
661 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
662 {
663 	if (!bpf_prog_kallsyms_candidate(fp) ||
664 	    !bpf_capable())
665 		return;
666 
667 	bpf_prog_ksym_set_addr(fp);
668 	bpf_prog_ksym_set_name(fp);
669 	fp->aux->ksym.prog = true;
670 
671 	bpf_ksym_add(&fp->aux->ksym);
672 }
673 
674 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
675 {
676 	if (!bpf_prog_kallsyms_candidate(fp))
677 		return;
678 
679 	bpf_ksym_del(&fp->aux->ksym);
680 }
681 
682 static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
683 {
684 	struct latch_tree_node *n;
685 
686 	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
687 	return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
688 }
689 
690 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
691 				 unsigned long *off, char *sym)
692 {
693 	struct bpf_ksym *ksym;
694 	char *ret = NULL;
695 
696 	rcu_read_lock();
697 	ksym = bpf_ksym_find(addr);
698 	if (ksym) {
699 		unsigned long symbol_start = ksym->start;
700 		unsigned long symbol_end = ksym->end;
701 
702 		strncpy(sym, ksym->name, KSYM_NAME_LEN);
703 
704 		ret = sym;
705 		if (size)
706 			*size = symbol_end - symbol_start;
707 		if (off)
708 			*off  = addr - symbol_start;
709 	}
710 	rcu_read_unlock();
711 
712 	return ret;
713 }
714 
715 bool is_bpf_text_address(unsigned long addr)
716 {
717 	bool ret;
718 
719 	rcu_read_lock();
720 	ret = bpf_ksym_find(addr) != NULL;
721 	rcu_read_unlock();
722 
723 	return ret;
724 }
725 
726 static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
727 {
728 	struct bpf_ksym *ksym = bpf_ksym_find(addr);
729 
730 	return ksym && ksym->prog ?
731 	       container_of(ksym, struct bpf_prog_aux, ksym)->prog :
732 	       NULL;
733 }
734 
735 const struct exception_table_entry *search_bpf_extables(unsigned long addr)
736 {
737 	const struct exception_table_entry *e = NULL;
738 	struct bpf_prog *prog;
739 
740 	rcu_read_lock();
741 	prog = bpf_prog_ksym_find(addr);
742 	if (!prog)
743 		goto out;
744 	if (!prog->aux->num_exentries)
745 		goto out;
746 
747 	e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
748 out:
749 	rcu_read_unlock();
750 	return e;
751 }
752 
753 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
754 		    char *sym)
755 {
756 	struct bpf_ksym *ksym;
757 	unsigned int it = 0;
758 	int ret = -ERANGE;
759 
760 	if (!bpf_jit_kallsyms_enabled())
761 		return ret;
762 
763 	rcu_read_lock();
764 	list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
765 		if (it++ != symnum)
766 			continue;
767 
768 		strncpy(sym, ksym->name, KSYM_NAME_LEN);
769 
770 		*value = ksym->start;
771 		*type  = BPF_SYM_ELF_TYPE;
772 
773 		ret = 0;
774 		break;
775 	}
776 	rcu_read_unlock();
777 
778 	return ret;
779 }
780 
781 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
782 				struct bpf_jit_poke_descriptor *poke)
783 {
784 	struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
785 	static const u32 poke_tab_max = 1024;
786 	u32 slot = prog->aux->size_poke_tab;
787 	u32 size = slot + 1;
788 
789 	if (size > poke_tab_max)
790 		return -ENOSPC;
791 	if (poke->tailcall_target || poke->tailcall_target_stable ||
792 	    poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
793 		return -EINVAL;
794 
795 	switch (poke->reason) {
796 	case BPF_POKE_REASON_TAIL_CALL:
797 		if (!poke->tail_call.map)
798 			return -EINVAL;
799 		break;
800 	default:
801 		return -EINVAL;
802 	}
803 
804 	tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
805 	if (!tab)
806 		return -ENOMEM;
807 
808 	memcpy(&tab[slot], poke, sizeof(*poke));
809 	prog->aux->size_poke_tab = size;
810 	prog->aux->poke_tab = tab;
811 
812 	return slot;
813 }
814 
815 /*
816  * BPF program pack allocator.
817  *
818  * Most BPF programs are pretty small. Allocating a hole page for each
819  * program is sometime a waste. Many small bpf program also adds pressure
820  * to instruction TLB. To solve this issue, we introduce a BPF program pack
821  * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
822  * to host BPF programs.
823  */
824 #define BPF_PROG_CHUNK_SHIFT	6
825 #define BPF_PROG_CHUNK_SIZE	(1 << BPF_PROG_CHUNK_SHIFT)
826 #define BPF_PROG_CHUNK_MASK	(~(BPF_PROG_CHUNK_SIZE - 1))
827 
828 struct bpf_prog_pack {
829 	struct list_head list;
830 	void *ptr;
831 	unsigned long bitmap[];
832 };
833 
834 void bpf_jit_fill_hole_with_zero(void *area, unsigned int size)
835 {
836 	memset(area, 0, size);
837 }
838 
839 #define BPF_PROG_SIZE_TO_NBITS(size)	(round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
840 
841 static DEFINE_MUTEX(pack_mutex);
842 static LIST_HEAD(pack_list);
843 
844 /* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
845  * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
846  */
847 #ifdef PMD_SIZE
848 #define BPF_PROG_PACK_SIZE (PMD_SIZE * num_possible_nodes())
849 #else
850 #define BPF_PROG_PACK_SIZE PAGE_SIZE
851 #endif
852 
853 #define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
854 
855 static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
856 {
857 	struct bpf_prog_pack *pack;
858 
859 	pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)),
860 		       GFP_KERNEL);
861 	if (!pack)
862 		return NULL;
863 	pack->ptr = module_alloc(BPF_PROG_PACK_SIZE);
864 	if (!pack->ptr) {
865 		kfree(pack);
866 		return NULL;
867 	}
868 	bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
869 	bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
870 	list_add_tail(&pack->list, &pack_list);
871 
872 	set_vm_flush_reset_perms(pack->ptr);
873 	set_memory_rox((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE);
874 	return pack;
875 }
876 
877 void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
878 {
879 	unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
880 	struct bpf_prog_pack *pack;
881 	unsigned long pos;
882 	void *ptr = NULL;
883 
884 	mutex_lock(&pack_mutex);
885 	if (size > BPF_PROG_PACK_SIZE) {
886 		size = round_up(size, PAGE_SIZE);
887 		ptr = module_alloc(size);
888 		if (ptr) {
889 			bpf_fill_ill_insns(ptr, size);
890 			set_vm_flush_reset_perms(ptr);
891 			set_memory_rox((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 >> 1,
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 = get_random_u32_below(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 = get_random_u32_below(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 	int err;
1191 
1192 	*func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1193 	if (!*func_addr_fixed) {
1194 		/* Place-holder address till the last pass has collected
1195 		 * all addresses for JITed subprograms in which case we
1196 		 * can pick them up from prog->aux.
1197 		 */
1198 		if (!extra_pass)
1199 			addr = NULL;
1200 		else if (prog->aux->func &&
1201 			 off >= 0 && off < prog->aux->func_cnt)
1202 			addr = (u8 *)prog->aux->func[off]->bpf_func;
1203 		else
1204 			return -EINVAL;
1205 	} else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL &&
1206 		   bpf_jit_supports_far_kfunc_call()) {
1207 		err = bpf_get_kfunc_addr(prog, insn->imm, insn->off, &addr);
1208 		if (err)
1209 			return err;
1210 	} else {
1211 		/* Address of a BPF helper call. Since part of the core
1212 		 * kernel, it's always at a fixed location. __bpf_call_base
1213 		 * and the helper with imm relative to it are both in core
1214 		 * kernel.
1215 		 */
1216 		addr = (u8 *)__bpf_call_base + imm;
1217 	}
1218 
1219 	*func_addr = (unsigned long)addr;
1220 	return 0;
1221 }
1222 
1223 static int bpf_jit_blind_insn(const struct bpf_insn *from,
1224 			      const struct bpf_insn *aux,
1225 			      struct bpf_insn *to_buff,
1226 			      bool emit_zext)
1227 {
1228 	struct bpf_insn *to = to_buff;
1229 	u32 imm_rnd = get_random_u32();
1230 	s16 off;
1231 
1232 	BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
1233 	BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
1234 
1235 	/* Constraints on AX register:
1236 	 *
1237 	 * AX register is inaccessible from user space. It is mapped in
1238 	 * all JITs, and used here for constant blinding rewrites. It is
1239 	 * typically "stateless" meaning its contents are only valid within
1240 	 * the executed instruction, but not across several instructions.
1241 	 * There are a few exceptions however which are further detailed
1242 	 * below.
1243 	 *
1244 	 * Constant blinding is only used by JITs, not in the interpreter.
1245 	 * The interpreter uses AX in some occasions as a local temporary
1246 	 * register e.g. in DIV or MOD instructions.
1247 	 *
1248 	 * In restricted circumstances, the verifier can also use the AX
1249 	 * register for rewrites as long as they do not interfere with
1250 	 * the above cases!
1251 	 */
1252 	if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1253 		goto out;
1254 
1255 	if (from->imm == 0 &&
1256 	    (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
1257 	     from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1258 		*to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1259 		goto out;
1260 	}
1261 
1262 	switch (from->code) {
1263 	case BPF_ALU | BPF_ADD | BPF_K:
1264 	case BPF_ALU | BPF_SUB | BPF_K:
1265 	case BPF_ALU | BPF_AND | BPF_K:
1266 	case BPF_ALU | BPF_OR  | BPF_K:
1267 	case BPF_ALU | BPF_XOR | BPF_K:
1268 	case BPF_ALU | BPF_MUL | BPF_K:
1269 	case BPF_ALU | BPF_MOV | BPF_K:
1270 	case BPF_ALU | BPF_DIV | BPF_K:
1271 	case BPF_ALU | BPF_MOD | BPF_K:
1272 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1273 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1274 		*to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
1275 		break;
1276 
1277 	case BPF_ALU64 | BPF_ADD | BPF_K:
1278 	case BPF_ALU64 | BPF_SUB | BPF_K:
1279 	case BPF_ALU64 | BPF_AND | BPF_K:
1280 	case BPF_ALU64 | BPF_OR  | BPF_K:
1281 	case BPF_ALU64 | BPF_XOR | BPF_K:
1282 	case BPF_ALU64 | BPF_MUL | BPF_K:
1283 	case BPF_ALU64 | BPF_MOV | BPF_K:
1284 	case BPF_ALU64 | BPF_DIV | BPF_K:
1285 	case BPF_ALU64 | BPF_MOD | BPF_K:
1286 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1287 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1288 		*to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
1289 		break;
1290 
1291 	case BPF_JMP | BPF_JEQ  | BPF_K:
1292 	case BPF_JMP | BPF_JNE  | BPF_K:
1293 	case BPF_JMP | BPF_JGT  | BPF_K:
1294 	case BPF_JMP | BPF_JLT  | BPF_K:
1295 	case BPF_JMP | BPF_JGE  | BPF_K:
1296 	case BPF_JMP | BPF_JLE  | BPF_K:
1297 	case BPF_JMP | BPF_JSGT | BPF_K:
1298 	case BPF_JMP | BPF_JSLT | BPF_K:
1299 	case BPF_JMP | BPF_JSGE | BPF_K:
1300 	case BPF_JMP | BPF_JSLE | BPF_K:
1301 	case BPF_JMP | BPF_JSET | BPF_K:
1302 		/* Accommodate for extra offset in case of a backjump. */
1303 		off = from->off;
1304 		if (off < 0)
1305 			off -= 2;
1306 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1307 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1308 		*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1309 		break;
1310 
1311 	case BPF_JMP32 | BPF_JEQ  | BPF_K:
1312 	case BPF_JMP32 | BPF_JNE  | BPF_K:
1313 	case BPF_JMP32 | BPF_JGT  | BPF_K:
1314 	case BPF_JMP32 | BPF_JLT  | BPF_K:
1315 	case BPF_JMP32 | BPF_JGE  | BPF_K:
1316 	case BPF_JMP32 | BPF_JLE  | BPF_K:
1317 	case BPF_JMP32 | BPF_JSGT | BPF_K:
1318 	case BPF_JMP32 | BPF_JSLT | BPF_K:
1319 	case BPF_JMP32 | BPF_JSGE | BPF_K:
1320 	case BPF_JMP32 | BPF_JSLE | BPF_K:
1321 	case BPF_JMP32 | BPF_JSET | BPF_K:
1322 		/* Accommodate for extra offset in case of a backjump. */
1323 		off = from->off;
1324 		if (off < 0)
1325 			off -= 2;
1326 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1327 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1328 		*to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1329 				      off);
1330 		break;
1331 
1332 	case BPF_LD | BPF_IMM | BPF_DW:
1333 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1334 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1335 		*to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1336 		*to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1337 		break;
1338 	case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1339 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1340 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1341 		if (emit_zext)
1342 			*to++ = BPF_ZEXT_REG(BPF_REG_AX);
1343 		*to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
1344 		break;
1345 
1346 	case BPF_ST | BPF_MEM | BPF_DW:
1347 	case BPF_ST | BPF_MEM | BPF_W:
1348 	case BPF_ST | BPF_MEM | BPF_H:
1349 	case BPF_ST | BPF_MEM | BPF_B:
1350 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1351 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1352 		*to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1353 		break;
1354 	}
1355 out:
1356 	return to - to_buff;
1357 }
1358 
1359 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1360 					      gfp_t gfp_extra_flags)
1361 {
1362 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1363 	struct bpf_prog *fp;
1364 
1365 	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1366 	if (fp != NULL) {
1367 		/* aux->prog still points to the fp_other one, so
1368 		 * when promoting the clone to the real program,
1369 		 * this still needs to be adapted.
1370 		 */
1371 		memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1372 	}
1373 
1374 	return fp;
1375 }
1376 
1377 static void bpf_prog_clone_free(struct bpf_prog *fp)
1378 {
1379 	/* aux was stolen by the other clone, so we cannot free
1380 	 * it from this path! It will be freed eventually by the
1381 	 * other program on release.
1382 	 *
1383 	 * At this point, we don't need a deferred release since
1384 	 * clone is guaranteed to not be locked.
1385 	 */
1386 	fp->aux = NULL;
1387 	fp->stats = NULL;
1388 	fp->active = NULL;
1389 	__bpf_prog_free(fp);
1390 }
1391 
1392 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1393 {
1394 	/* We have to repoint aux->prog to self, as we don't
1395 	 * know whether fp here is the clone or the original.
1396 	 */
1397 	fp->aux->prog = fp;
1398 	bpf_prog_clone_free(fp_other);
1399 }
1400 
1401 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1402 {
1403 	struct bpf_insn insn_buff[16], aux[2];
1404 	struct bpf_prog *clone, *tmp;
1405 	int insn_delta, insn_cnt;
1406 	struct bpf_insn *insn;
1407 	int i, rewritten;
1408 
1409 	if (!prog->blinding_requested || prog->blinded)
1410 		return prog;
1411 
1412 	clone = bpf_prog_clone_create(prog, GFP_USER);
1413 	if (!clone)
1414 		return ERR_PTR(-ENOMEM);
1415 
1416 	insn_cnt = clone->len;
1417 	insn = clone->insnsi;
1418 
1419 	for (i = 0; i < insn_cnt; i++, insn++) {
1420 		if (bpf_pseudo_func(insn)) {
1421 			/* ld_imm64 with an address of bpf subprog is not
1422 			 * a user controlled constant. Don't randomize it,
1423 			 * since it will conflict with jit_subprogs() logic.
1424 			 */
1425 			insn++;
1426 			i++;
1427 			continue;
1428 		}
1429 
1430 		/* We temporarily need to hold the original ld64 insn
1431 		 * so that we can still access the first part in the
1432 		 * second blinding run.
1433 		 */
1434 		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1435 		    insn[1].code == 0)
1436 			memcpy(aux, insn, sizeof(aux));
1437 
1438 		rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1439 						clone->aux->verifier_zext);
1440 		if (!rewritten)
1441 			continue;
1442 
1443 		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1444 		if (IS_ERR(tmp)) {
1445 			/* Patching may have repointed aux->prog during
1446 			 * realloc from the original one, so we need to
1447 			 * fix it up here on error.
1448 			 */
1449 			bpf_jit_prog_release_other(prog, clone);
1450 			return tmp;
1451 		}
1452 
1453 		clone = tmp;
1454 		insn_delta = rewritten - 1;
1455 
1456 		/* Walk new program and skip insns we just inserted. */
1457 		insn = clone->insnsi + i + insn_delta;
1458 		insn_cnt += insn_delta;
1459 		i        += insn_delta;
1460 	}
1461 
1462 	clone->blinded = 1;
1463 	return clone;
1464 }
1465 #endif /* CONFIG_BPF_JIT */
1466 
1467 /* Base function for offset calculation. Needs to go into .text section,
1468  * therefore keeping it non-static as well; will also be used by JITs
1469  * anyway later on, so do not let the compiler omit it. This also needs
1470  * to go into kallsyms for correlation from e.g. bpftool, so naming
1471  * must not change.
1472  */
1473 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1474 {
1475 	return 0;
1476 }
1477 EXPORT_SYMBOL_GPL(__bpf_call_base);
1478 
1479 /* All UAPI available opcodes. */
1480 #define BPF_INSN_MAP(INSN_2, INSN_3)		\
1481 	/* 32 bit ALU operations. */		\
1482 	/*   Register based. */			\
1483 	INSN_3(ALU, ADD,  X),			\
1484 	INSN_3(ALU, SUB,  X),			\
1485 	INSN_3(ALU, AND,  X),			\
1486 	INSN_3(ALU, OR,   X),			\
1487 	INSN_3(ALU, LSH,  X),			\
1488 	INSN_3(ALU, RSH,  X),			\
1489 	INSN_3(ALU, XOR,  X),			\
1490 	INSN_3(ALU, MUL,  X),			\
1491 	INSN_3(ALU, MOV,  X),			\
1492 	INSN_3(ALU, ARSH, X),			\
1493 	INSN_3(ALU, DIV,  X),			\
1494 	INSN_3(ALU, MOD,  X),			\
1495 	INSN_2(ALU, NEG),			\
1496 	INSN_3(ALU, END, TO_BE),		\
1497 	INSN_3(ALU, END, TO_LE),		\
1498 	/*   Immediate based. */		\
1499 	INSN_3(ALU, ADD,  K),			\
1500 	INSN_3(ALU, SUB,  K),			\
1501 	INSN_3(ALU, AND,  K),			\
1502 	INSN_3(ALU, OR,   K),			\
1503 	INSN_3(ALU, LSH,  K),			\
1504 	INSN_3(ALU, RSH,  K),			\
1505 	INSN_3(ALU, XOR,  K),			\
1506 	INSN_3(ALU, MUL,  K),			\
1507 	INSN_3(ALU, MOV,  K),			\
1508 	INSN_3(ALU, ARSH, K),			\
1509 	INSN_3(ALU, DIV,  K),			\
1510 	INSN_3(ALU, MOD,  K),			\
1511 	/* 64 bit ALU operations. */		\
1512 	/*   Register based. */			\
1513 	INSN_3(ALU64, ADD,  X),			\
1514 	INSN_3(ALU64, SUB,  X),			\
1515 	INSN_3(ALU64, AND,  X),			\
1516 	INSN_3(ALU64, OR,   X),			\
1517 	INSN_3(ALU64, LSH,  X),			\
1518 	INSN_3(ALU64, RSH,  X),			\
1519 	INSN_3(ALU64, XOR,  X),			\
1520 	INSN_3(ALU64, MUL,  X),			\
1521 	INSN_3(ALU64, MOV,  X),			\
1522 	INSN_3(ALU64, ARSH, X),			\
1523 	INSN_3(ALU64, DIV,  X),			\
1524 	INSN_3(ALU64, MOD,  X),			\
1525 	INSN_2(ALU64, NEG),			\
1526 	/*   Immediate based. */		\
1527 	INSN_3(ALU64, ADD,  K),			\
1528 	INSN_3(ALU64, SUB,  K),			\
1529 	INSN_3(ALU64, AND,  K),			\
1530 	INSN_3(ALU64, OR,   K),			\
1531 	INSN_3(ALU64, LSH,  K),			\
1532 	INSN_3(ALU64, RSH,  K),			\
1533 	INSN_3(ALU64, XOR,  K),			\
1534 	INSN_3(ALU64, MUL,  K),			\
1535 	INSN_3(ALU64, MOV,  K),			\
1536 	INSN_3(ALU64, ARSH, K),			\
1537 	INSN_3(ALU64, DIV,  K),			\
1538 	INSN_3(ALU64, MOD,  K),			\
1539 	/* Call instruction. */			\
1540 	INSN_2(JMP, CALL),			\
1541 	/* Exit instruction. */			\
1542 	INSN_2(JMP, EXIT),			\
1543 	/* 32-bit Jump instructions. */		\
1544 	/*   Register based. */			\
1545 	INSN_3(JMP32, JEQ,  X),			\
1546 	INSN_3(JMP32, JNE,  X),			\
1547 	INSN_3(JMP32, JGT,  X),			\
1548 	INSN_3(JMP32, JLT,  X),			\
1549 	INSN_3(JMP32, JGE,  X),			\
1550 	INSN_3(JMP32, JLE,  X),			\
1551 	INSN_3(JMP32, JSGT, X),			\
1552 	INSN_3(JMP32, JSLT, X),			\
1553 	INSN_3(JMP32, JSGE, X),			\
1554 	INSN_3(JMP32, JSLE, X),			\
1555 	INSN_3(JMP32, JSET, X),			\
1556 	/*   Immediate based. */		\
1557 	INSN_3(JMP32, JEQ,  K),			\
1558 	INSN_3(JMP32, JNE,  K),			\
1559 	INSN_3(JMP32, JGT,  K),			\
1560 	INSN_3(JMP32, JLT,  K),			\
1561 	INSN_3(JMP32, JGE,  K),			\
1562 	INSN_3(JMP32, JLE,  K),			\
1563 	INSN_3(JMP32, JSGT, K),			\
1564 	INSN_3(JMP32, JSLT, K),			\
1565 	INSN_3(JMP32, JSGE, K),			\
1566 	INSN_3(JMP32, JSLE, K),			\
1567 	INSN_3(JMP32, JSET, K),			\
1568 	/* Jump instructions. */		\
1569 	/*   Register based. */			\
1570 	INSN_3(JMP, JEQ,  X),			\
1571 	INSN_3(JMP, JNE,  X),			\
1572 	INSN_3(JMP, JGT,  X),			\
1573 	INSN_3(JMP, JLT,  X),			\
1574 	INSN_3(JMP, JGE,  X),			\
1575 	INSN_3(JMP, JLE,  X),			\
1576 	INSN_3(JMP, JSGT, X),			\
1577 	INSN_3(JMP, JSLT, X),			\
1578 	INSN_3(JMP, JSGE, X),			\
1579 	INSN_3(JMP, JSLE, X),			\
1580 	INSN_3(JMP, JSET, X),			\
1581 	/*   Immediate based. */		\
1582 	INSN_3(JMP, JEQ,  K),			\
1583 	INSN_3(JMP, JNE,  K),			\
1584 	INSN_3(JMP, JGT,  K),			\
1585 	INSN_3(JMP, JLT,  K),			\
1586 	INSN_3(JMP, JGE,  K),			\
1587 	INSN_3(JMP, JLE,  K),			\
1588 	INSN_3(JMP, JSGT, K),			\
1589 	INSN_3(JMP, JSLT, K),			\
1590 	INSN_3(JMP, JSGE, K),			\
1591 	INSN_3(JMP, JSLE, K),			\
1592 	INSN_3(JMP, JSET, K),			\
1593 	INSN_2(JMP, JA),			\
1594 	/* Store instructions. */		\
1595 	/*   Register based. */			\
1596 	INSN_3(STX, MEM,  B),			\
1597 	INSN_3(STX, MEM,  H),			\
1598 	INSN_3(STX, MEM,  W),			\
1599 	INSN_3(STX, MEM,  DW),			\
1600 	INSN_3(STX, ATOMIC, W),			\
1601 	INSN_3(STX, ATOMIC, DW),		\
1602 	/*   Immediate based. */		\
1603 	INSN_3(ST, MEM, B),			\
1604 	INSN_3(ST, MEM, H),			\
1605 	INSN_3(ST, MEM, W),			\
1606 	INSN_3(ST, MEM, DW),			\
1607 	/* Load instructions. */		\
1608 	/*   Register based. */			\
1609 	INSN_3(LDX, MEM, B),			\
1610 	INSN_3(LDX, MEM, H),			\
1611 	INSN_3(LDX, MEM, W),			\
1612 	INSN_3(LDX, MEM, DW),			\
1613 	/*   Immediate based. */		\
1614 	INSN_3(LD, IMM, DW)
1615 
1616 bool bpf_opcode_in_insntable(u8 code)
1617 {
1618 #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
1619 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1620 	static const bool public_insntable[256] = {
1621 		[0 ... 255] = false,
1622 		/* Now overwrite non-defaults ... */
1623 		BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1624 		/* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1625 		[BPF_LD | BPF_ABS | BPF_B] = true,
1626 		[BPF_LD | BPF_ABS | BPF_H] = true,
1627 		[BPF_LD | BPF_ABS | BPF_W] = true,
1628 		[BPF_LD | BPF_IND | BPF_B] = true,
1629 		[BPF_LD | BPF_IND | BPF_H] = true,
1630 		[BPF_LD | BPF_IND | BPF_W] = true,
1631 	};
1632 #undef BPF_INSN_3_TBL
1633 #undef BPF_INSN_2_TBL
1634 	return public_insntable[code];
1635 }
1636 
1637 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1638 u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
1639 {
1640 	memset(dst, 0, size);
1641 	return -EFAULT;
1642 }
1643 
1644 /**
1645  *	___bpf_prog_run - run eBPF program on a given context
1646  *	@regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1647  *	@insn: is the array of eBPF instructions
1648  *
1649  * Decode and execute eBPF instructions.
1650  *
1651  * Return: whatever value is in %BPF_R0 at program exit
1652  */
1653 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1654 {
1655 #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
1656 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1657 	static const void * const jumptable[256] __annotate_jump_table = {
1658 		[0 ... 255] = &&default_label,
1659 		/* Now overwrite non-defaults ... */
1660 		BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1661 		/* Non-UAPI available opcodes. */
1662 		[BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1663 		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1664 		[BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
1665 		[BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1666 		[BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1667 		[BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1668 		[BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1669 	};
1670 #undef BPF_INSN_3_LBL
1671 #undef BPF_INSN_2_LBL
1672 	u32 tail_call_cnt = 0;
1673 
1674 #define CONT	 ({ insn++; goto select_insn; })
1675 #define CONT_JMP ({ insn++; goto select_insn; })
1676 
1677 select_insn:
1678 	goto *jumptable[insn->code];
1679 
1680 	/* Explicitly mask the register-based shift amounts with 63 or 31
1681 	 * to avoid undefined behavior. Normally this won't affect the
1682 	 * generated code, for example, in case of native 64 bit archs such
1683 	 * as x86-64 or arm64, the compiler is optimizing the AND away for
1684 	 * the interpreter. In case of JITs, each of the JIT backends compiles
1685 	 * the BPF shift operations to machine instructions which produce
1686 	 * implementation-defined results in such a case; the resulting
1687 	 * contents of the register may be arbitrary, but program behaviour
1688 	 * as a whole remains defined. In other words, in case of JIT backends,
1689 	 * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1690 	 */
1691 	/* ALU (shifts) */
1692 #define SHT(OPCODE, OP)					\
1693 	ALU64_##OPCODE##_X:				\
1694 		DST = DST OP (SRC & 63);		\
1695 		CONT;					\
1696 	ALU_##OPCODE##_X:				\
1697 		DST = (u32) DST OP ((u32) SRC & 31);	\
1698 		CONT;					\
1699 	ALU64_##OPCODE##_K:				\
1700 		DST = DST OP IMM;			\
1701 		CONT;					\
1702 	ALU_##OPCODE##_K:				\
1703 		DST = (u32) DST OP (u32) IMM;		\
1704 		CONT;
1705 	/* ALU (rest) */
1706 #define ALU(OPCODE, OP)					\
1707 	ALU64_##OPCODE##_X:				\
1708 		DST = DST OP SRC;			\
1709 		CONT;					\
1710 	ALU_##OPCODE##_X:				\
1711 		DST = (u32) DST OP (u32) SRC;		\
1712 		CONT;					\
1713 	ALU64_##OPCODE##_K:				\
1714 		DST = DST OP IMM;			\
1715 		CONT;					\
1716 	ALU_##OPCODE##_K:				\
1717 		DST = (u32) DST OP (u32) IMM;		\
1718 		CONT;
1719 	ALU(ADD,  +)
1720 	ALU(SUB,  -)
1721 	ALU(AND,  &)
1722 	ALU(OR,   |)
1723 	ALU(XOR,  ^)
1724 	ALU(MUL,  *)
1725 	SHT(LSH, <<)
1726 	SHT(RSH, >>)
1727 #undef SHT
1728 #undef ALU
1729 	ALU_NEG:
1730 		DST = (u32) -DST;
1731 		CONT;
1732 	ALU64_NEG:
1733 		DST = -DST;
1734 		CONT;
1735 	ALU_MOV_X:
1736 		DST = (u32) SRC;
1737 		CONT;
1738 	ALU_MOV_K:
1739 		DST = (u32) IMM;
1740 		CONT;
1741 	ALU64_MOV_X:
1742 		DST = SRC;
1743 		CONT;
1744 	ALU64_MOV_K:
1745 		DST = IMM;
1746 		CONT;
1747 	LD_IMM_DW:
1748 		DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1749 		insn++;
1750 		CONT;
1751 	ALU_ARSH_X:
1752 		DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1753 		CONT;
1754 	ALU_ARSH_K:
1755 		DST = (u64) (u32) (((s32) DST) >> IMM);
1756 		CONT;
1757 	ALU64_ARSH_X:
1758 		(*(s64 *) &DST) >>= (SRC & 63);
1759 		CONT;
1760 	ALU64_ARSH_K:
1761 		(*(s64 *) &DST) >>= IMM;
1762 		CONT;
1763 	ALU64_MOD_X:
1764 		div64_u64_rem(DST, SRC, &AX);
1765 		DST = AX;
1766 		CONT;
1767 	ALU_MOD_X:
1768 		AX = (u32) DST;
1769 		DST = do_div(AX, (u32) SRC);
1770 		CONT;
1771 	ALU64_MOD_K:
1772 		div64_u64_rem(DST, IMM, &AX);
1773 		DST = AX;
1774 		CONT;
1775 	ALU_MOD_K:
1776 		AX = (u32) DST;
1777 		DST = do_div(AX, (u32) IMM);
1778 		CONT;
1779 	ALU64_DIV_X:
1780 		DST = div64_u64(DST, SRC);
1781 		CONT;
1782 	ALU_DIV_X:
1783 		AX = (u32) DST;
1784 		do_div(AX, (u32) SRC);
1785 		DST = (u32) AX;
1786 		CONT;
1787 	ALU64_DIV_K:
1788 		DST = div64_u64(DST, IMM);
1789 		CONT;
1790 	ALU_DIV_K:
1791 		AX = (u32) DST;
1792 		do_div(AX, (u32) IMM);
1793 		DST = (u32) AX;
1794 		CONT;
1795 	ALU_END_TO_BE:
1796 		switch (IMM) {
1797 		case 16:
1798 			DST = (__force u16) cpu_to_be16(DST);
1799 			break;
1800 		case 32:
1801 			DST = (__force u32) cpu_to_be32(DST);
1802 			break;
1803 		case 64:
1804 			DST = (__force u64) cpu_to_be64(DST);
1805 			break;
1806 		}
1807 		CONT;
1808 	ALU_END_TO_LE:
1809 		switch (IMM) {
1810 		case 16:
1811 			DST = (__force u16) cpu_to_le16(DST);
1812 			break;
1813 		case 32:
1814 			DST = (__force u32) cpu_to_le32(DST);
1815 			break;
1816 		case 64:
1817 			DST = (__force u64) cpu_to_le64(DST);
1818 			break;
1819 		}
1820 		CONT;
1821 
1822 	/* CALL */
1823 	JMP_CALL:
1824 		/* Function call scratches BPF_R1-BPF_R5 registers,
1825 		 * preserves BPF_R6-BPF_R9, and stores return value
1826 		 * into BPF_R0.
1827 		 */
1828 		BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1829 						       BPF_R4, BPF_R5);
1830 		CONT;
1831 
1832 	JMP_CALL_ARGS:
1833 		BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
1834 							    BPF_R3, BPF_R4,
1835 							    BPF_R5,
1836 							    insn + insn->off + 1);
1837 		CONT;
1838 
1839 	JMP_TAIL_CALL: {
1840 		struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1841 		struct bpf_array *array = container_of(map, struct bpf_array, map);
1842 		struct bpf_prog *prog;
1843 		u32 index = BPF_R3;
1844 
1845 		if (unlikely(index >= array->map.max_entries))
1846 			goto out;
1847 
1848 		if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
1849 			goto out;
1850 
1851 		tail_call_cnt++;
1852 
1853 		prog = READ_ONCE(array->ptrs[index]);
1854 		if (!prog)
1855 			goto out;
1856 
1857 		/* ARG1 at this point is guaranteed to point to CTX from
1858 		 * the verifier side due to the fact that the tail call is
1859 		 * handled like a helper, that is, bpf_tail_call_proto,
1860 		 * where arg1_type is ARG_PTR_TO_CTX.
1861 		 */
1862 		insn = prog->insnsi;
1863 		goto select_insn;
1864 out:
1865 		CONT;
1866 	}
1867 	JMP_JA:
1868 		insn += insn->off;
1869 		CONT;
1870 	JMP_EXIT:
1871 		return BPF_R0;
1872 	/* JMP */
1873 #define COND_JMP(SIGN, OPCODE, CMP_OP)				\
1874 	JMP_##OPCODE##_X:					\
1875 		if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {	\
1876 			insn += insn->off;			\
1877 			CONT_JMP;				\
1878 		}						\
1879 		CONT;						\
1880 	JMP32_##OPCODE##_X:					\
1881 		if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {	\
1882 			insn += insn->off;			\
1883 			CONT_JMP;				\
1884 		}						\
1885 		CONT;						\
1886 	JMP_##OPCODE##_K:					\
1887 		if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {	\
1888 			insn += insn->off;			\
1889 			CONT_JMP;				\
1890 		}						\
1891 		CONT;						\
1892 	JMP32_##OPCODE##_K:					\
1893 		if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {	\
1894 			insn += insn->off;			\
1895 			CONT_JMP;				\
1896 		}						\
1897 		CONT;
1898 	COND_JMP(u, JEQ, ==)
1899 	COND_JMP(u, JNE, !=)
1900 	COND_JMP(u, JGT, >)
1901 	COND_JMP(u, JLT, <)
1902 	COND_JMP(u, JGE, >=)
1903 	COND_JMP(u, JLE, <=)
1904 	COND_JMP(u, JSET, &)
1905 	COND_JMP(s, JSGT, >)
1906 	COND_JMP(s, JSLT, <)
1907 	COND_JMP(s, JSGE, >=)
1908 	COND_JMP(s, JSLE, <=)
1909 #undef COND_JMP
1910 	/* ST, STX and LDX*/
1911 	ST_NOSPEC:
1912 		/* Speculation barrier for mitigating Speculative Store Bypass.
1913 		 * In case of arm64, we rely on the firmware mitigation as
1914 		 * controlled via the ssbd kernel parameter. Whenever the
1915 		 * mitigation is enabled, it works for all of the kernel code
1916 		 * with no need to provide any additional instructions here.
1917 		 * In case of x86, we use 'lfence' insn for mitigation. We
1918 		 * reuse preexisting logic from Spectre v1 mitigation that
1919 		 * happens to produce the required code on x86 for v4 as well.
1920 		 */
1921 		barrier_nospec();
1922 		CONT;
1923 #define LDST(SIZEOP, SIZE)						\
1924 	STX_MEM_##SIZEOP:						\
1925 		*(SIZE *)(unsigned long) (DST + insn->off) = SRC;	\
1926 		CONT;							\
1927 	ST_MEM_##SIZEOP:						\
1928 		*(SIZE *)(unsigned long) (DST + insn->off) = IMM;	\
1929 		CONT;							\
1930 	LDX_MEM_##SIZEOP:						\
1931 		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
1932 		CONT;							\
1933 	LDX_PROBE_MEM_##SIZEOP:						\
1934 		bpf_probe_read_kernel(&DST, sizeof(SIZE),		\
1935 				      (const void *)(long) (SRC + insn->off));	\
1936 		DST = *((SIZE *)&DST);					\
1937 		CONT;
1938 
1939 	LDST(B,   u8)
1940 	LDST(H,  u16)
1941 	LDST(W,  u32)
1942 	LDST(DW, u64)
1943 #undef LDST
1944 
1945 #define ATOMIC_ALU_OP(BOP, KOP)						\
1946 		case BOP:						\
1947 			if (BPF_SIZE(insn->code) == BPF_W)		\
1948 				atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
1949 					     (DST + insn->off));	\
1950 			else						\
1951 				atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
1952 					       (DST + insn->off));	\
1953 			break;						\
1954 		case BOP | BPF_FETCH:					\
1955 			if (BPF_SIZE(insn->code) == BPF_W)		\
1956 				SRC = (u32) atomic_fetch_##KOP(		\
1957 					(u32) SRC,			\
1958 					(atomic_t *)(unsigned long) (DST + insn->off)); \
1959 			else						\
1960 				SRC = (u64) atomic64_fetch_##KOP(	\
1961 					(u64) SRC,			\
1962 					(atomic64_t *)(unsigned long) (DST + insn->off)); \
1963 			break;
1964 
1965 	STX_ATOMIC_DW:
1966 	STX_ATOMIC_W:
1967 		switch (IMM) {
1968 		ATOMIC_ALU_OP(BPF_ADD, add)
1969 		ATOMIC_ALU_OP(BPF_AND, and)
1970 		ATOMIC_ALU_OP(BPF_OR, or)
1971 		ATOMIC_ALU_OP(BPF_XOR, xor)
1972 #undef ATOMIC_ALU_OP
1973 
1974 		case BPF_XCHG:
1975 			if (BPF_SIZE(insn->code) == BPF_W)
1976 				SRC = (u32) atomic_xchg(
1977 					(atomic_t *)(unsigned long) (DST + insn->off),
1978 					(u32) SRC);
1979 			else
1980 				SRC = (u64) atomic64_xchg(
1981 					(atomic64_t *)(unsigned long) (DST + insn->off),
1982 					(u64) SRC);
1983 			break;
1984 		case BPF_CMPXCHG:
1985 			if (BPF_SIZE(insn->code) == BPF_W)
1986 				BPF_R0 = (u32) atomic_cmpxchg(
1987 					(atomic_t *)(unsigned long) (DST + insn->off),
1988 					(u32) BPF_R0, (u32) SRC);
1989 			else
1990 				BPF_R0 = (u64) atomic64_cmpxchg(
1991 					(atomic64_t *)(unsigned long) (DST + insn->off),
1992 					(u64) BPF_R0, (u64) SRC);
1993 			break;
1994 
1995 		default:
1996 			goto default_label;
1997 		}
1998 		CONT;
1999 
2000 	default_label:
2001 		/* If we ever reach this, we have a bug somewhere. Die hard here
2002 		 * instead of just returning 0; we could be somewhere in a subprog,
2003 		 * so execution could continue otherwise which we do /not/ want.
2004 		 *
2005 		 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2006 		 */
2007 		pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2008 			insn->code, insn->imm);
2009 		BUG_ON(1);
2010 		return 0;
2011 }
2012 
2013 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2014 #define DEFINE_BPF_PROG_RUN(stack_size) \
2015 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2016 { \
2017 	u64 stack[stack_size / sizeof(u64)]; \
2018 	u64 regs[MAX_BPF_EXT_REG] = {}; \
2019 \
2020 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2021 	ARG1 = (u64) (unsigned long) ctx; \
2022 	return ___bpf_prog_run(regs, insn); \
2023 }
2024 
2025 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2026 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2027 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2028 				      const struct bpf_insn *insn) \
2029 { \
2030 	u64 stack[stack_size / sizeof(u64)]; \
2031 	u64 regs[MAX_BPF_EXT_REG]; \
2032 \
2033 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2034 	BPF_R1 = r1; \
2035 	BPF_R2 = r2; \
2036 	BPF_R3 = r3; \
2037 	BPF_R4 = r4; \
2038 	BPF_R5 = r5; \
2039 	return ___bpf_prog_run(regs, insn); \
2040 }
2041 
2042 #define EVAL1(FN, X) FN(X)
2043 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2044 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2045 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2046 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2047 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2048 
2049 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2050 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2051 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2052 
2053 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2054 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2055 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2056 
2057 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2058 
2059 static unsigned int (*interpreters[])(const void *ctx,
2060 				      const struct bpf_insn *insn) = {
2061 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2062 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2063 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2064 };
2065 #undef PROG_NAME_LIST
2066 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2067 static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2068 				  const struct bpf_insn *insn) = {
2069 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2070 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2071 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2072 };
2073 #undef PROG_NAME_LIST
2074 
2075 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2076 {
2077 	stack_depth = max_t(u32, stack_depth, 1);
2078 	insn->off = (s16) insn->imm;
2079 	insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
2080 		__bpf_call_base_args;
2081 	insn->code = BPF_JMP | BPF_CALL_ARGS;
2082 }
2083 
2084 #else
2085 static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2086 					 const struct bpf_insn *insn)
2087 {
2088 	/* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2089 	 * is not working properly, so warn about it!
2090 	 */
2091 	WARN_ON_ONCE(1);
2092 	return 0;
2093 }
2094 #endif
2095 
2096 bool bpf_prog_map_compatible(struct bpf_map *map,
2097 			     const struct bpf_prog *fp)
2098 {
2099 	enum bpf_prog_type prog_type = resolve_prog_type(fp);
2100 	bool ret;
2101 
2102 	if (fp->kprobe_override)
2103 		return false;
2104 
2105 	/* XDP programs inserted into maps are not guaranteed to run on
2106 	 * a particular netdev (and can run outside driver context entirely
2107 	 * in the case of devmap and cpumap). Until device checks
2108 	 * are implemented, prohibit adding dev-bound programs to program maps.
2109 	 */
2110 	if (bpf_prog_is_dev_bound(fp->aux))
2111 		return false;
2112 
2113 	spin_lock(&map->owner.lock);
2114 	if (!map->owner.type) {
2115 		/* There's no owner yet where we could check for
2116 		 * compatibility.
2117 		 */
2118 		map->owner.type  = prog_type;
2119 		map->owner.jited = fp->jited;
2120 		map->owner.xdp_has_frags = fp->aux->xdp_has_frags;
2121 		ret = true;
2122 	} else {
2123 		ret = map->owner.type  == prog_type &&
2124 		      map->owner.jited == fp->jited &&
2125 		      map->owner.xdp_has_frags == fp->aux->xdp_has_frags;
2126 	}
2127 	spin_unlock(&map->owner.lock);
2128 
2129 	return ret;
2130 }
2131 
2132 static int bpf_check_tail_call(const struct bpf_prog *fp)
2133 {
2134 	struct bpf_prog_aux *aux = fp->aux;
2135 	int i, ret = 0;
2136 
2137 	mutex_lock(&aux->used_maps_mutex);
2138 	for (i = 0; i < aux->used_map_cnt; i++) {
2139 		struct bpf_map *map = aux->used_maps[i];
2140 
2141 		if (!map_type_contains_progs(map))
2142 			continue;
2143 
2144 		if (!bpf_prog_map_compatible(map, fp)) {
2145 			ret = -EINVAL;
2146 			goto out;
2147 		}
2148 	}
2149 
2150 out:
2151 	mutex_unlock(&aux->used_maps_mutex);
2152 	return ret;
2153 }
2154 
2155 static void bpf_prog_select_func(struct bpf_prog *fp)
2156 {
2157 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
2158 	u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2159 
2160 	fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
2161 #else
2162 	fp->bpf_func = __bpf_prog_ret0_warn;
2163 #endif
2164 }
2165 
2166 /**
2167  *	bpf_prog_select_runtime - select exec runtime for BPF program
2168  *	@fp: bpf_prog populated with BPF program
2169  *	@err: pointer to error variable
2170  *
2171  * Try to JIT eBPF program, if JIT is not available, use interpreter.
2172  * The BPF program will be executed via bpf_prog_run() function.
2173  *
2174  * Return: the &fp argument along with &err set to 0 for success or
2175  * a negative errno code on failure
2176  */
2177 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2178 {
2179 	/* In case of BPF to BPF calls, verifier did all the prep
2180 	 * work with regards to JITing, etc.
2181 	 */
2182 	bool jit_needed = false;
2183 
2184 	if (fp->bpf_func)
2185 		goto finalize;
2186 
2187 	if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
2188 	    bpf_prog_has_kfunc_call(fp))
2189 		jit_needed = true;
2190 
2191 	bpf_prog_select_func(fp);
2192 
2193 	/* eBPF JITs can rewrite the program in case constant
2194 	 * blinding is active. However, in case of error during
2195 	 * blinding, bpf_int_jit_compile() must always return a
2196 	 * valid program, which in this case would simply not
2197 	 * be JITed, but falls back to the interpreter.
2198 	 */
2199 	if (!bpf_prog_is_offloaded(fp->aux)) {
2200 		*err = bpf_prog_alloc_jited_linfo(fp);
2201 		if (*err)
2202 			return fp;
2203 
2204 		fp = bpf_int_jit_compile(fp);
2205 		bpf_prog_jit_attempt_done(fp);
2206 		if (!fp->jited && jit_needed) {
2207 			*err = -ENOTSUPP;
2208 			return fp;
2209 		}
2210 	} else {
2211 		*err = bpf_prog_offload_compile(fp);
2212 		if (*err)
2213 			return fp;
2214 	}
2215 
2216 finalize:
2217 	bpf_prog_lock_ro(fp);
2218 
2219 	/* The tail call compatibility check can only be done at
2220 	 * this late stage as we need to determine, if we deal
2221 	 * with JITed or non JITed program concatenations and not
2222 	 * all eBPF JITs might immediately support all features.
2223 	 */
2224 	*err = bpf_check_tail_call(fp);
2225 
2226 	return fp;
2227 }
2228 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2229 
2230 static unsigned int __bpf_prog_ret1(const void *ctx,
2231 				    const struct bpf_insn *insn)
2232 {
2233 	return 1;
2234 }
2235 
2236 static struct bpf_prog_dummy {
2237 	struct bpf_prog prog;
2238 } dummy_bpf_prog = {
2239 	.prog = {
2240 		.bpf_func = __bpf_prog_ret1,
2241 	},
2242 };
2243 
2244 struct bpf_empty_prog_array bpf_empty_prog_array = {
2245 	.null_prog = NULL,
2246 };
2247 EXPORT_SYMBOL(bpf_empty_prog_array);
2248 
2249 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2250 {
2251 	if (prog_cnt)
2252 		return kzalloc(sizeof(struct bpf_prog_array) +
2253 			       sizeof(struct bpf_prog_array_item) *
2254 			       (prog_cnt + 1),
2255 			       flags);
2256 
2257 	return &bpf_empty_prog_array.hdr;
2258 }
2259 
2260 void bpf_prog_array_free(struct bpf_prog_array *progs)
2261 {
2262 	if (!progs || progs == &bpf_empty_prog_array.hdr)
2263 		return;
2264 	kfree_rcu(progs, rcu);
2265 }
2266 
2267 static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2268 {
2269 	struct bpf_prog_array *progs;
2270 
2271 	/* If RCU Tasks Trace grace period implies RCU grace period, there is
2272 	 * no need to call kfree_rcu(), just call kfree() directly.
2273 	 */
2274 	progs = container_of(rcu, struct bpf_prog_array, rcu);
2275 	if (rcu_trace_implies_rcu_gp())
2276 		kfree(progs);
2277 	else
2278 		kfree_rcu(progs, rcu);
2279 }
2280 
2281 void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2282 {
2283 	if (!progs || progs == &bpf_empty_prog_array.hdr)
2284 		return;
2285 	call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2286 }
2287 
2288 int bpf_prog_array_length(struct bpf_prog_array *array)
2289 {
2290 	struct bpf_prog_array_item *item;
2291 	u32 cnt = 0;
2292 
2293 	for (item = array->items; item->prog; item++)
2294 		if (item->prog != &dummy_bpf_prog.prog)
2295 			cnt++;
2296 	return cnt;
2297 }
2298 
2299 bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2300 {
2301 	struct bpf_prog_array_item *item;
2302 
2303 	for (item = array->items; item->prog; item++)
2304 		if (item->prog != &dummy_bpf_prog.prog)
2305 			return false;
2306 	return true;
2307 }
2308 
2309 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2310 				     u32 *prog_ids,
2311 				     u32 request_cnt)
2312 {
2313 	struct bpf_prog_array_item *item;
2314 	int i = 0;
2315 
2316 	for (item = array->items; item->prog; item++) {
2317 		if (item->prog == &dummy_bpf_prog.prog)
2318 			continue;
2319 		prog_ids[i] = item->prog->aux->id;
2320 		if (++i == request_cnt) {
2321 			item++;
2322 			break;
2323 		}
2324 	}
2325 
2326 	return !!(item->prog);
2327 }
2328 
2329 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2330 				__u32 __user *prog_ids, u32 cnt)
2331 {
2332 	unsigned long err = 0;
2333 	bool nospc;
2334 	u32 *ids;
2335 
2336 	/* users of this function are doing:
2337 	 * cnt = bpf_prog_array_length();
2338 	 * if (cnt > 0)
2339 	 *     bpf_prog_array_copy_to_user(..., cnt);
2340 	 * so below kcalloc doesn't need extra cnt > 0 check.
2341 	 */
2342 	ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2343 	if (!ids)
2344 		return -ENOMEM;
2345 	nospc = bpf_prog_array_copy_core(array, ids, cnt);
2346 	err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2347 	kfree(ids);
2348 	if (err)
2349 		return -EFAULT;
2350 	if (nospc)
2351 		return -ENOSPC;
2352 	return 0;
2353 }
2354 
2355 void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2356 				struct bpf_prog *old_prog)
2357 {
2358 	struct bpf_prog_array_item *item;
2359 
2360 	for (item = array->items; item->prog; item++)
2361 		if (item->prog == old_prog) {
2362 			WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2363 			break;
2364 		}
2365 }
2366 
2367 /**
2368  * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2369  *                                   index into the program array with
2370  *                                   a dummy no-op program.
2371  * @array: a bpf_prog_array
2372  * @index: the index of the program to replace
2373  *
2374  * Skips over dummy programs, by not counting them, when calculating
2375  * the position of the program to replace.
2376  *
2377  * Return:
2378  * * 0		- Success
2379  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2380  * * -ENOENT	- Index out of range
2381  */
2382 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2383 {
2384 	return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2385 }
2386 
2387 /**
2388  * bpf_prog_array_update_at() - Updates the program at the given index
2389  *                              into the program array.
2390  * @array: a bpf_prog_array
2391  * @index: the index of the program to update
2392  * @prog: the program to insert into the array
2393  *
2394  * Skips over dummy programs, by not counting them, when calculating
2395  * the position of the program to update.
2396  *
2397  * Return:
2398  * * 0		- Success
2399  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2400  * * -ENOENT	- Index out of range
2401  */
2402 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2403 			     struct bpf_prog *prog)
2404 {
2405 	struct bpf_prog_array_item *item;
2406 
2407 	if (unlikely(index < 0))
2408 		return -EINVAL;
2409 
2410 	for (item = array->items; item->prog; item++) {
2411 		if (item->prog == &dummy_bpf_prog.prog)
2412 			continue;
2413 		if (!index) {
2414 			WRITE_ONCE(item->prog, prog);
2415 			return 0;
2416 		}
2417 		index--;
2418 	}
2419 	return -ENOENT;
2420 }
2421 
2422 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2423 			struct bpf_prog *exclude_prog,
2424 			struct bpf_prog *include_prog,
2425 			u64 bpf_cookie,
2426 			struct bpf_prog_array **new_array)
2427 {
2428 	int new_prog_cnt, carry_prog_cnt = 0;
2429 	struct bpf_prog_array_item *existing, *new;
2430 	struct bpf_prog_array *array;
2431 	bool found_exclude = false;
2432 
2433 	/* Figure out how many existing progs we need to carry over to
2434 	 * the new array.
2435 	 */
2436 	if (old_array) {
2437 		existing = old_array->items;
2438 		for (; existing->prog; existing++) {
2439 			if (existing->prog == exclude_prog) {
2440 				found_exclude = true;
2441 				continue;
2442 			}
2443 			if (existing->prog != &dummy_bpf_prog.prog)
2444 				carry_prog_cnt++;
2445 			if (existing->prog == include_prog)
2446 				return -EEXIST;
2447 		}
2448 	}
2449 
2450 	if (exclude_prog && !found_exclude)
2451 		return -ENOENT;
2452 
2453 	/* How many progs (not NULL) will be in the new array? */
2454 	new_prog_cnt = carry_prog_cnt;
2455 	if (include_prog)
2456 		new_prog_cnt += 1;
2457 
2458 	/* Do we have any prog (not NULL) in the new array? */
2459 	if (!new_prog_cnt) {
2460 		*new_array = NULL;
2461 		return 0;
2462 	}
2463 
2464 	/* +1 as the end of prog_array is marked with NULL */
2465 	array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2466 	if (!array)
2467 		return -ENOMEM;
2468 	new = array->items;
2469 
2470 	/* Fill in the new prog array */
2471 	if (carry_prog_cnt) {
2472 		existing = old_array->items;
2473 		for (; existing->prog; existing++) {
2474 			if (existing->prog == exclude_prog ||
2475 			    existing->prog == &dummy_bpf_prog.prog)
2476 				continue;
2477 
2478 			new->prog = existing->prog;
2479 			new->bpf_cookie = existing->bpf_cookie;
2480 			new++;
2481 		}
2482 	}
2483 	if (include_prog) {
2484 		new->prog = include_prog;
2485 		new->bpf_cookie = bpf_cookie;
2486 		new++;
2487 	}
2488 	new->prog = NULL;
2489 	*new_array = array;
2490 	return 0;
2491 }
2492 
2493 int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2494 			     u32 *prog_ids, u32 request_cnt,
2495 			     u32 *prog_cnt)
2496 {
2497 	u32 cnt = 0;
2498 
2499 	if (array)
2500 		cnt = bpf_prog_array_length(array);
2501 
2502 	*prog_cnt = cnt;
2503 
2504 	/* return early if user requested only program count or nothing to copy */
2505 	if (!request_cnt || !cnt)
2506 		return 0;
2507 
2508 	/* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2509 	return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2510 								     : 0;
2511 }
2512 
2513 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2514 			  struct bpf_map **used_maps, u32 len)
2515 {
2516 	struct bpf_map *map;
2517 	u32 i;
2518 
2519 	for (i = 0; i < len; i++) {
2520 		map = used_maps[i];
2521 		if (map->ops->map_poke_untrack)
2522 			map->ops->map_poke_untrack(map, aux);
2523 		bpf_map_put(map);
2524 	}
2525 }
2526 
2527 static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2528 {
2529 	__bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2530 	kfree(aux->used_maps);
2531 }
2532 
2533 void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
2534 			  struct btf_mod_pair *used_btfs, u32 len)
2535 {
2536 #ifdef CONFIG_BPF_SYSCALL
2537 	struct btf_mod_pair *btf_mod;
2538 	u32 i;
2539 
2540 	for (i = 0; i < len; i++) {
2541 		btf_mod = &used_btfs[i];
2542 		if (btf_mod->module)
2543 			module_put(btf_mod->module);
2544 		btf_put(btf_mod->btf);
2545 	}
2546 #endif
2547 }
2548 
2549 static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2550 {
2551 	__bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt);
2552 	kfree(aux->used_btfs);
2553 }
2554 
2555 static void bpf_prog_free_deferred(struct work_struct *work)
2556 {
2557 	struct bpf_prog_aux *aux;
2558 	int i;
2559 
2560 	aux = container_of(work, struct bpf_prog_aux, work);
2561 #ifdef CONFIG_BPF_SYSCALL
2562 	bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
2563 #endif
2564 #ifdef CONFIG_CGROUP_BPF
2565 	if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
2566 		bpf_cgroup_atype_put(aux->cgroup_atype);
2567 #endif
2568 	bpf_free_used_maps(aux);
2569 	bpf_free_used_btfs(aux);
2570 	if (bpf_prog_is_dev_bound(aux))
2571 		bpf_prog_dev_bound_destroy(aux->prog);
2572 #ifdef CONFIG_PERF_EVENTS
2573 	if (aux->prog->has_callchain_buf)
2574 		put_callchain_buffers();
2575 #endif
2576 	if (aux->dst_trampoline)
2577 		bpf_trampoline_put(aux->dst_trampoline);
2578 	for (i = 0; i < aux->func_cnt; i++) {
2579 		/* We can just unlink the subprog poke descriptor table as
2580 		 * it was originally linked to the main program and is also
2581 		 * released along with it.
2582 		 */
2583 		aux->func[i]->aux->poke_tab = NULL;
2584 		bpf_jit_free(aux->func[i]);
2585 	}
2586 	if (aux->func_cnt) {
2587 		kfree(aux->func);
2588 		bpf_prog_unlock_free(aux->prog);
2589 	} else {
2590 		bpf_jit_free(aux->prog);
2591 	}
2592 }
2593 
2594 void bpf_prog_free(struct bpf_prog *fp)
2595 {
2596 	struct bpf_prog_aux *aux = fp->aux;
2597 
2598 	if (aux->dst_prog)
2599 		bpf_prog_put(aux->dst_prog);
2600 	INIT_WORK(&aux->work, bpf_prog_free_deferred);
2601 	schedule_work(&aux->work);
2602 }
2603 EXPORT_SYMBOL_GPL(bpf_prog_free);
2604 
2605 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
2606 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2607 
2608 void bpf_user_rnd_init_once(void)
2609 {
2610 	prandom_init_once(&bpf_user_rnd_state);
2611 }
2612 
2613 BPF_CALL_0(bpf_user_rnd_u32)
2614 {
2615 	/* Should someone ever have the rather unwise idea to use some
2616 	 * of the registers passed into this function, then note that
2617 	 * this function is called from native eBPF and classic-to-eBPF
2618 	 * transformations. Register assignments from both sides are
2619 	 * different, f.e. classic always sets fn(ctx, A, X) here.
2620 	 */
2621 	struct rnd_state *state;
2622 	u32 res;
2623 
2624 	state = &get_cpu_var(bpf_user_rnd_state);
2625 	res = prandom_u32_state(state);
2626 	put_cpu_var(bpf_user_rnd_state);
2627 
2628 	return res;
2629 }
2630 
2631 BPF_CALL_0(bpf_get_raw_cpu_id)
2632 {
2633 	return raw_smp_processor_id();
2634 }
2635 
2636 /* Weak definitions of helper functions in case we don't have bpf syscall. */
2637 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2638 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2639 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2640 const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2641 const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2642 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2643 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
2644 const struct bpf_func_proto bpf_spin_lock_proto __weak;
2645 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2646 const struct bpf_func_proto bpf_jiffies64_proto __weak;
2647 
2648 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2649 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2650 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2651 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2652 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2653 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2654 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
2655 
2656 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2657 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2658 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2659 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2660 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2661 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2662 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2663 const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2664 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2665 const struct bpf_func_proto bpf_set_retval_proto __weak;
2666 const struct bpf_func_proto bpf_get_retval_proto __weak;
2667 
2668 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2669 {
2670 	return NULL;
2671 }
2672 
2673 const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
2674 {
2675 	return NULL;
2676 }
2677 
2678 u64 __weak
2679 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2680 		 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2681 {
2682 	return -ENOTSUPP;
2683 }
2684 EXPORT_SYMBOL_GPL(bpf_event_output);
2685 
2686 /* Always built-in helper functions. */
2687 const struct bpf_func_proto bpf_tail_call_proto = {
2688 	.func		= NULL,
2689 	.gpl_only	= false,
2690 	.ret_type	= RET_VOID,
2691 	.arg1_type	= ARG_PTR_TO_CTX,
2692 	.arg2_type	= ARG_CONST_MAP_PTR,
2693 	.arg3_type	= ARG_ANYTHING,
2694 };
2695 
2696 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2697  * It is encouraged to implement bpf_int_jit_compile() instead, so that
2698  * eBPF and implicitly also cBPF can get JITed!
2699  */
2700 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2701 {
2702 	return prog;
2703 }
2704 
2705 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
2706  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2707  */
2708 void __weak bpf_jit_compile(struct bpf_prog *prog)
2709 {
2710 }
2711 
2712 bool __weak bpf_helper_changes_pkt_data(void *func)
2713 {
2714 	return false;
2715 }
2716 
2717 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2718  * analysis code and wants explicit zero extension inserted by verifier.
2719  * Otherwise, return FALSE.
2720  *
2721  * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2722  * you don't override this. JITs that don't want these extra insns can detect
2723  * them using insn_is_zext.
2724  */
2725 bool __weak bpf_jit_needs_zext(void)
2726 {
2727 	return false;
2728 }
2729 
2730 /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
2731 bool __weak bpf_jit_supports_subprog_tailcalls(void)
2732 {
2733 	return false;
2734 }
2735 
2736 bool __weak bpf_jit_supports_kfunc_call(void)
2737 {
2738 	return false;
2739 }
2740 
2741 bool __weak bpf_jit_supports_far_kfunc_call(void)
2742 {
2743 	return false;
2744 }
2745 
2746 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
2747  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
2748  */
2749 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
2750 			 int len)
2751 {
2752 	return -EFAULT;
2753 }
2754 
2755 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
2756 			      void *addr1, void *addr2)
2757 {
2758 	return -ENOTSUPP;
2759 }
2760 
2761 void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
2762 {
2763 	return ERR_PTR(-ENOTSUPP);
2764 }
2765 
2766 int __weak bpf_arch_text_invalidate(void *dst, size_t len)
2767 {
2768 	return -ENOTSUPP;
2769 }
2770 
2771 #ifdef CONFIG_BPF_SYSCALL
2772 static int __init bpf_global_ma_init(void)
2773 {
2774 	int ret;
2775 
2776 	ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
2777 	bpf_global_ma_set = !ret;
2778 	return ret;
2779 }
2780 late_initcall(bpf_global_ma_init);
2781 #endif
2782 
2783 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
2784 EXPORT_SYMBOL(bpf_stats_enabled_key);
2785 
2786 /* All definitions of tracepoints related to BPF. */
2787 #define CREATE_TRACE_POINTS
2788 #include <linux/bpf_trace.h>
2789 
2790 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
2791 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);
2792