xref: /openbmc/linux/kernel/bpf/core.c (revision 0845c3db)
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 OFF	insn->off
65 #define IMM	insn->imm
66 
67 struct bpf_mem_alloc bpf_global_ma;
68 bool bpf_global_ma_set;
69 
70 /* No hurry in this branch
71  *
72  * Exported for the bpf jit load helper.
73  */
74 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
75 {
76 	u8 *ptr = NULL;
77 
78 	if (k >= SKF_NET_OFF) {
79 		ptr = skb_network_header(skb) + k - SKF_NET_OFF;
80 	} else if (k >= SKF_LL_OFF) {
81 		if (unlikely(!skb_mac_header_was_set(skb)))
82 			return NULL;
83 		ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
84 	}
85 	if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
86 		return ptr;
87 
88 	return NULL;
89 }
90 
91 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
92 {
93 	gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
94 	struct bpf_prog_aux *aux;
95 	struct bpf_prog *fp;
96 
97 	size = round_up(size, PAGE_SIZE);
98 	fp = __vmalloc(size, gfp_flags);
99 	if (fp == NULL)
100 		return NULL;
101 
102 	aux = kzalloc(sizeof(*aux), bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
103 	if (aux == NULL) {
104 		vfree(fp);
105 		return NULL;
106 	}
107 	fp->active = alloc_percpu_gfp(int, bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
108 	if (!fp->active) {
109 		vfree(fp);
110 		kfree(aux);
111 		return NULL;
112 	}
113 
114 	fp->pages = size / PAGE_SIZE;
115 	fp->aux = aux;
116 	fp->aux->prog = fp;
117 	fp->jit_requested = ebpf_jit_enabled();
118 	fp->blinding_requested = bpf_jit_blinding_enabled(fp);
119 #ifdef CONFIG_CGROUP_BPF
120 	aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID;
121 #endif
122 
123 	INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
124 	mutex_init(&fp->aux->used_maps_mutex);
125 	mutex_init(&fp->aux->dst_mutex);
126 
127 	return fp;
128 }
129 
130 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
131 {
132 	gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
133 	struct bpf_prog *prog;
134 	int cpu;
135 
136 	prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
137 	if (!prog)
138 		return NULL;
139 
140 	prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
141 	if (!prog->stats) {
142 		free_percpu(prog->active);
143 		kfree(prog->aux);
144 		vfree(prog);
145 		return NULL;
146 	}
147 
148 	for_each_possible_cpu(cpu) {
149 		struct bpf_prog_stats *pstats;
150 
151 		pstats = per_cpu_ptr(prog->stats, cpu);
152 		u64_stats_init(&pstats->syncp);
153 	}
154 	return prog;
155 }
156 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
157 
158 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
159 {
160 	if (!prog->aux->nr_linfo || !prog->jit_requested)
161 		return 0;
162 
163 	prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
164 					  sizeof(*prog->aux->jited_linfo),
165 					  bpf_memcg_flags(GFP_KERNEL | __GFP_NOWARN));
166 	if (!prog->aux->jited_linfo)
167 		return -ENOMEM;
168 
169 	return 0;
170 }
171 
172 void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
173 {
174 	if (prog->aux->jited_linfo &&
175 	    (!prog->jited || !prog->aux->jited_linfo[0])) {
176 		kvfree(prog->aux->jited_linfo);
177 		prog->aux->jited_linfo = NULL;
178 	}
179 
180 	kfree(prog->aux->kfunc_tab);
181 	prog->aux->kfunc_tab = NULL;
182 }
183 
184 /* The jit engine is responsible to provide an array
185  * for insn_off to the jited_off mapping (insn_to_jit_off).
186  *
187  * The idx to this array is the insn_off.  Hence, the insn_off
188  * here is relative to the prog itself instead of the main prog.
189  * This array has one entry for each xlated bpf insn.
190  *
191  * jited_off is the byte off to the end of the jited insn.
192  *
193  * Hence, with
194  * insn_start:
195  *      The first bpf insn off of the prog.  The insn off
196  *      here is relative to the main prog.
197  *      e.g. if prog is a subprog, insn_start > 0
198  * linfo_idx:
199  *      The prog's idx to prog->aux->linfo and jited_linfo
200  *
201  * jited_linfo[linfo_idx] = prog->bpf_func
202  *
203  * For i > linfo_idx,
204  *
205  * jited_linfo[i] = prog->bpf_func +
206  *	insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
207  */
208 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
209 			       const u32 *insn_to_jit_off)
210 {
211 	u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
212 	const struct bpf_line_info *linfo;
213 	void **jited_linfo;
214 
215 	if (!prog->aux->jited_linfo)
216 		/* Userspace did not provide linfo */
217 		return;
218 
219 	linfo_idx = prog->aux->linfo_idx;
220 	linfo = &prog->aux->linfo[linfo_idx];
221 	insn_start = linfo[0].insn_off;
222 	insn_end = insn_start + prog->len;
223 
224 	jited_linfo = &prog->aux->jited_linfo[linfo_idx];
225 	jited_linfo[0] = prog->bpf_func;
226 
227 	nr_linfo = prog->aux->nr_linfo - linfo_idx;
228 
229 	for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
230 		/* The verifier ensures that linfo[i].insn_off is
231 		 * strictly increasing
232 		 */
233 		jited_linfo[i] = prog->bpf_func +
234 			insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
235 }
236 
237 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
238 				  gfp_t gfp_extra_flags)
239 {
240 	gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
241 	struct bpf_prog *fp;
242 	u32 pages;
243 
244 	size = round_up(size, PAGE_SIZE);
245 	pages = size / PAGE_SIZE;
246 	if (pages <= fp_old->pages)
247 		return fp_old;
248 
249 	fp = __vmalloc(size, gfp_flags);
250 	if (fp) {
251 		memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
252 		fp->pages = pages;
253 		fp->aux->prog = fp;
254 
255 		/* We keep fp->aux from fp_old around in the new
256 		 * reallocated structure.
257 		 */
258 		fp_old->aux = NULL;
259 		fp_old->stats = NULL;
260 		fp_old->active = NULL;
261 		__bpf_prog_free(fp_old);
262 	}
263 
264 	return fp;
265 }
266 
267 void __bpf_prog_free(struct bpf_prog *fp)
268 {
269 	if (fp->aux) {
270 		mutex_destroy(&fp->aux->used_maps_mutex);
271 		mutex_destroy(&fp->aux->dst_mutex);
272 		kfree(fp->aux->poke_tab);
273 		kfree(fp->aux);
274 	}
275 	free_percpu(fp->stats);
276 	free_percpu(fp->active);
277 	vfree(fp);
278 }
279 
280 int bpf_prog_calc_tag(struct bpf_prog *fp)
281 {
282 	const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
283 	u32 raw_size = bpf_prog_tag_scratch_size(fp);
284 	u32 digest[SHA1_DIGEST_WORDS];
285 	u32 ws[SHA1_WORKSPACE_WORDS];
286 	u32 i, bsize, psize, blocks;
287 	struct bpf_insn *dst;
288 	bool was_ld_map;
289 	u8 *raw, *todo;
290 	__be32 *result;
291 	__be64 *bits;
292 
293 	raw = vmalloc(raw_size);
294 	if (!raw)
295 		return -ENOMEM;
296 
297 	sha1_init(digest);
298 	memset(ws, 0, sizeof(ws));
299 
300 	/* We need to take out the map fd for the digest calculation
301 	 * since they are unstable from user space side.
302 	 */
303 	dst = (void *)raw;
304 	for (i = 0, was_ld_map = false; i < fp->len; i++) {
305 		dst[i] = fp->insnsi[i];
306 		if (!was_ld_map &&
307 		    dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
308 		    (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
309 		     dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
310 			was_ld_map = true;
311 			dst[i].imm = 0;
312 		} else if (was_ld_map &&
313 			   dst[i].code == 0 &&
314 			   dst[i].dst_reg == 0 &&
315 			   dst[i].src_reg == 0 &&
316 			   dst[i].off == 0) {
317 			was_ld_map = false;
318 			dst[i].imm = 0;
319 		} else {
320 			was_ld_map = false;
321 		}
322 	}
323 
324 	psize = bpf_prog_insn_size(fp);
325 	memset(&raw[psize], 0, raw_size - psize);
326 	raw[psize++] = 0x80;
327 
328 	bsize  = round_up(psize, SHA1_BLOCK_SIZE);
329 	blocks = bsize / SHA1_BLOCK_SIZE;
330 	todo   = raw;
331 	if (bsize - psize >= sizeof(__be64)) {
332 		bits = (__be64 *)(todo + bsize - sizeof(__be64));
333 	} else {
334 		bits = (__be64 *)(todo + bsize + bits_offset);
335 		blocks++;
336 	}
337 	*bits = cpu_to_be64((psize - 1) << 3);
338 
339 	while (blocks--) {
340 		sha1_transform(digest, todo, ws);
341 		todo += SHA1_BLOCK_SIZE;
342 	}
343 
344 	result = (__force __be32 *)digest;
345 	for (i = 0; i < SHA1_DIGEST_WORDS; i++)
346 		result[i] = cpu_to_be32(digest[i]);
347 	memcpy(fp->tag, result, sizeof(fp->tag));
348 
349 	vfree(raw);
350 	return 0;
351 }
352 
353 static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
354 				s32 end_new, s32 curr, const bool probe_pass)
355 {
356 	const s64 imm_min = S32_MIN, imm_max = S32_MAX;
357 	s32 delta = end_new - end_old;
358 	s64 imm = insn->imm;
359 
360 	if (curr < pos && curr + imm + 1 >= end_old)
361 		imm += delta;
362 	else if (curr >= end_new && curr + imm + 1 < end_new)
363 		imm -= delta;
364 	if (imm < imm_min || imm > imm_max)
365 		return -ERANGE;
366 	if (!probe_pass)
367 		insn->imm = imm;
368 	return 0;
369 }
370 
371 static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
372 				s32 end_new, s32 curr, const bool probe_pass)
373 {
374 	const s32 off_min = S16_MIN, off_max = S16_MAX;
375 	s32 delta = end_new - end_old;
376 	s32 off = insn->off;
377 
378 	if (curr < pos && curr + off + 1 >= end_old)
379 		off += delta;
380 	else if (curr >= end_new && curr + off + 1 < end_new)
381 		off -= delta;
382 	if (off < off_min || off > off_max)
383 		return -ERANGE;
384 	if (!probe_pass)
385 		insn->off = off;
386 	return 0;
387 }
388 
389 static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
390 			    s32 end_new, const bool probe_pass)
391 {
392 	u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
393 	struct bpf_insn *insn = prog->insnsi;
394 	int ret = 0;
395 
396 	for (i = 0; i < insn_cnt; i++, insn++) {
397 		u8 code;
398 
399 		/* In the probing pass we still operate on the original,
400 		 * unpatched image in order to check overflows before we
401 		 * do any other adjustments. Therefore skip the patchlet.
402 		 */
403 		if (probe_pass && i == pos) {
404 			i = end_new;
405 			insn = prog->insnsi + end_old;
406 		}
407 		if (bpf_pseudo_func(insn)) {
408 			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
409 						   end_new, i, probe_pass);
410 			if (ret)
411 				return ret;
412 			continue;
413 		}
414 		code = insn->code;
415 		if ((BPF_CLASS(code) != BPF_JMP &&
416 		     BPF_CLASS(code) != BPF_JMP32) ||
417 		    BPF_OP(code) == BPF_EXIT)
418 			continue;
419 		/* Adjust offset of jmps if we cross patch boundaries. */
420 		if (BPF_OP(code) == BPF_CALL) {
421 			if (insn->src_reg != BPF_PSEUDO_CALL)
422 				continue;
423 			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
424 						   end_new, i, probe_pass);
425 		} else {
426 			ret = bpf_adj_delta_to_off(insn, pos, end_old,
427 						   end_new, i, probe_pass);
428 		}
429 		if (ret)
430 			break;
431 	}
432 
433 	return ret;
434 }
435 
436 static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
437 {
438 	struct bpf_line_info *linfo;
439 	u32 i, nr_linfo;
440 
441 	nr_linfo = prog->aux->nr_linfo;
442 	if (!nr_linfo || !delta)
443 		return;
444 
445 	linfo = prog->aux->linfo;
446 
447 	for (i = 0; i < nr_linfo; i++)
448 		if (off < linfo[i].insn_off)
449 			break;
450 
451 	/* Push all off < linfo[i].insn_off by delta */
452 	for (; i < nr_linfo; i++)
453 		linfo[i].insn_off += delta;
454 }
455 
456 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
457 				       const struct bpf_insn *patch, u32 len)
458 {
459 	u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
460 	const u32 cnt_max = S16_MAX;
461 	struct bpf_prog *prog_adj;
462 	int err;
463 
464 	/* Since our patchlet doesn't expand the image, we're done. */
465 	if (insn_delta == 0) {
466 		memcpy(prog->insnsi + off, patch, sizeof(*patch));
467 		return prog;
468 	}
469 
470 	insn_adj_cnt = prog->len + insn_delta;
471 
472 	/* Reject anything that would potentially let the insn->off
473 	 * target overflow when we have excessive program expansions.
474 	 * We need to probe here before we do any reallocation where
475 	 * we afterwards may not fail anymore.
476 	 */
477 	if (insn_adj_cnt > cnt_max &&
478 	    (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
479 		return ERR_PTR(err);
480 
481 	/* Several new instructions need to be inserted. Make room
482 	 * for them. Likely, there's no need for a new allocation as
483 	 * last page could have large enough tailroom.
484 	 */
485 	prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
486 				    GFP_USER);
487 	if (!prog_adj)
488 		return ERR_PTR(-ENOMEM);
489 
490 	prog_adj->len = insn_adj_cnt;
491 
492 	/* Patching happens in 3 steps:
493 	 *
494 	 * 1) Move over tail of insnsi from next instruction onwards,
495 	 *    so we can patch the single target insn with one or more
496 	 *    new ones (patching is always from 1 to n insns, n > 0).
497 	 * 2) Inject new instructions at the target location.
498 	 * 3) Adjust branch offsets if necessary.
499 	 */
500 	insn_rest = insn_adj_cnt - off - len;
501 
502 	memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
503 		sizeof(*patch) * insn_rest);
504 	memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
505 
506 	/* We are guaranteed to not fail at this point, otherwise
507 	 * the ship has sailed to reverse to the original state. An
508 	 * overflow cannot happen at this point.
509 	 */
510 	BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
511 
512 	bpf_adj_linfo(prog_adj, off, insn_delta);
513 
514 	return prog_adj;
515 }
516 
517 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
518 {
519 	/* Branch offsets can't overflow when program is shrinking, no need
520 	 * to call bpf_adj_branches(..., true) here
521 	 */
522 	memmove(prog->insnsi + off, prog->insnsi + off + cnt,
523 		sizeof(struct bpf_insn) * (prog->len - off - cnt));
524 	prog->len -= cnt;
525 
526 	return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
527 }
528 
529 static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
530 {
531 	int i;
532 
533 	for (i = 0; i < fp->aux->func_cnt; i++)
534 		bpf_prog_kallsyms_del(fp->aux->func[i]);
535 }
536 
537 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
538 {
539 	bpf_prog_kallsyms_del_subprogs(fp);
540 	bpf_prog_kallsyms_del(fp);
541 }
542 
543 #ifdef CONFIG_BPF_JIT
544 /* All BPF JIT sysctl knobs here. */
545 int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
546 int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
547 int bpf_jit_harden   __read_mostly;
548 long bpf_jit_limit   __read_mostly;
549 long bpf_jit_limit_max __read_mostly;
550 
551 static void
552 bpf_prog_ksym_set_addr(struct bpf_prog *prog)
553 {
554 	WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
555 
556 	prog->aux->ksym.start = (unsigned long) prog->bpf_func;
557 	prog->aux->ksym.end   = prog->aux->ksym.start + prog->jited_len;
558 }
559 
560 static void
561 bpf_prog_ksym_set_name(struct bpf_prog *prog)
562 {
563 	char *sym = prog->aux->ksym.name;
564 	const char *end = sym + KSYM_NAME_LEN;
565 	const struct btf_type *type;
566 	const char *func_name;
567 
568 	BUILD_BUG_ON(sizeof("bpf_prog_") +
569 		     sizeof(prog->tag) * 2 +
570 		     /* name has been null terminated.
571 		      * We should need +1 for the '_' preceding
572 		      * the name.  However, the null character
573 		      * is double counted between the name and the
574 		      * sizeof("bpf_prog_") above, so we omit
575 		      * the +1 here.
576 		      */
577 		     sizeof(prog->aux->name) > KSYM_NAME_LEN);
578 
579 	sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
580 	sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
581 
582 	/* prog->aux->name will be ignored if full btf name is available */
583 	if (prog->aux->func_info_cnt) {
584 		type = btf_type_by_id(prog->aux->btf,
585 				      prog->aux->func_info[prog->aux->func_idx].type_id);
586 		func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
587 		snprintf(sym, (size_t)(end - sym), "_%s", func_name);
588 		return;
589 	}
590 
591 	if (prog->aux->name[0])
592 		snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
593 	else
594 		*sym = 0;
595 }
596 
597 static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
598 {
599 	return container_of(n, struct bpf_ksym, tnode)->start;
600 }
601 
602 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
603 					  struct latch_tree_node *b)
604 {
605 	return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
606 }
607 
608 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
609 {
610 	unsigned long val = (unsigned long)key;
611 	const struct bpf_ksym *ksym;
612 
613 	ksym = container_of(n, struct bpf_ksym, tnode);
614 
615 	if (val < ksym->start)
616 		return -1;
617 	if (val >= ksym->end)
618 		return  1;
619 
620 	return 0;
621 }
622 
623 static const struct latch_tree_ops bpf_tree_ops = {
624 	.less	= bpf_tree_less,
625 	.comp	= bpf_tree_comp,
626 };
627 
628 static DEFINE_SPINLOCK(bpf_lock);
629 static LIST_HEAD(bpf_kallsyms);
630 static struct latch_tree_root bpf_tree __cacheline_aligned;
631 
632 void bpf_ksym_add(struct bpf_ksym *ksym)
633 {
634 	spin_lock_bh(&bpf_lock);
635 	WARN_ON_ONCE(!list_empty(&ksym->lnode));
636 	list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
637 	latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
638 	spin_unlock_bh(&bpf_lock);
639 }
640 
641 static void __bpf_ksym_del(struct bpf_ksym *ksym)
642 {
643 	if (list_empty(&ksym->lnode))
644 		return;
645 
646 	latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
647 	list_del_rcu(&ksym->lnode);
648 }
649 
650 void bpf_ksym_del(struct bpf_ksym *ksym)
651 {
652 	spin_lock_bh(&bpf_lock);
653 	__bpf_ksym_del(ksym);
654 	spin_unlock_bh(&bpf_lock);
655 }
656 
657 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
658 {
659 	return fp->jited && !bpf_prog_was_classic(fp);
660 }
661 
662 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
663 {
664 	if (!bpf_prog_kallsyms_candidate(fp) ||
665 	    !bpf_capable())
666 		return;
667 
668 	bpf_prog_ksym_set_addr(fp);
669 	bpf_prog_ksym_set_name(fp);
670 	fp->aux->ksym.prog = true;
671 
672 	bpf_ksym_add(&fp->aux->ksym);
673 }
674 
675 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
676 {
677 	if (!bpf_prog_kallsyms_candidate(fp))
678 		return;
679 
680 	bpf_ksym_del(&fp->aux->ksym);
681 }
682 
683 static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
684 {
685 	struct latch_tree_node *n;
686 
687 	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
688 	return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
689 }
690 
691 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
692 				 unsigned long *off, char *sym)
693 {
694 	struct bpf_ksym *ksym;
695 	char *ret = NULL;
696 
697 	rcu_read_lock();
698 	ksym = bpf_ksym_find(addr);
699 	if (ksym) {
700 		unsigned long symbol_start = ksym->start;
701 		unsigned long symbol_end = ksym->end;
702 
703 		strncpy(sym, ksym->name, KSYM_NAME_LEN);
704 
705 		ret = sym;
706 		if (size)
707 			*size = symbol_end - symbol_start;
708 		if (off)
709 			*off  = addr - symbol_start;
710 	}
711 	rcu_read_unlock();
712 
713 	return ret;
714 }
715 
716 bool is_bpf_text_address(unsigned long addr)
717 {
718 	bool ret;
719 
720 	rcu_read_lock();
721 	ret = bpf_ksym_find(addr) != NULL;
722 	rcu_read_unlock();
723 
724 	return ret;
725 }
726 
727 static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
728 {
729 	struct bpf_ksym *ksym = bpf_ksym_find(addr);
730 
731 	return ksym && ksym->prog ?
732 	       container_of(ksym, struct bpf_prog_aux, ksym)->prog :
733 	       NULL;
734 }
735 
736 const struct exception_table_entry *search_bpf_extables(unsigned long addr)
737 {
738 	const struct exception_table_entry *e = NULL;
739 	struct bpf_prog *prog;
740 
741 	rcu_read_lock();
742 	prog = bpf_prog_ksym_find(addr);
743 	if (!prog)
744 		goto out;
745 	if (!prog->aux->num_exentries)
746 		goto out;
747 
748 	e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
749 out:
750 	rcu_read_unlock();
751 	return e;
752 }
753 
754 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
755 		    char *sym)
756 {
757 	struct bpf_ksym *ksym;
758 	unsigned int it = 0;
759 	int ret = -ERANGE;
760 
761 	if (!bpf_jit_kallsyms_enabled())
762 		return ret;
763 
764 	rcu_read_lock();
765 	list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
766 		if (it++ != symnum)
767 			continue;
768 
769 		strncpy(sym, ksym->name, KSYM_NAME_LEN);
770 
771 		*value = ksym->start;
772 		*type  = BPF_SYM_ELF_TYPE;
773 
774 		ret = 0;
775 		break;
776 	}
777 	rcu_read_unlock();
778 
779 	return ret;
780 }
781 
782 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
783 				struct bpf_jit_poke_descriptor *poke)
784 {
785 	struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
786 	static const u32 poke_tab_max = 1024;
787 	u32 slot = prog->aux->size_poke_tab;
788 	u32 size = slot + 1;
789 
790 	if (size > poke_tab_max)
791 		return -ENOSPC;
792 	if (poke->tailcall_target || poke->tailcall_target_stable ||
793 	    poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
794 		return -EINVAL;
795 
796 	switch (poke->reason) {
797 	case BPF_POKE_REASON_TAIL_CALL:
798 		if (!poke->tail_call.map)
799 			return -EINVAL;
800 		break;
801 	default:
802 		return -EINVAL;
803 	}
804 
805 	tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
806 	if (!tab)
807 		return -ENOMEM;
808 
809 	memcpy(&tab[slot], poke, sizeof(*poke));
810 	prog->aux->size_poke_tab = size;
811 	prog->aux->poke_tab = tab;
812 
813 	return slot;
814 }
815 
816 /*
817  * BPF program pack allocator.
818  *
819  * Most BPF programs are pretty small. Allocating a hole page for each
820  * program is sometime a waste. Many small bpf program also adds pressure
821  * to instruction TLB. To solve this issue, we introduce a BPF program pack
822  * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
823  * to host BPF programs.
824  */
825 #define BPF_PROG_CHUNK_SHIFT	6
826 #define BPF_PROG_CHUNK_SIZE	(1 << BPF_PROG_CHUNK_SHIFT)
827 #define BPF_PROG_CHUNK_MASK	(~(BPF_PROG_CHUNK_SIZE - 1))
828 
829 struct bpf_prog_pack {
830 	struct list_head list;
831 	void *ptr;
832 	unsigned long bitmap[];
833 };
834 
835 void bpf_jit_fill_hole_with_zero(void *area, unsigned int size)
836 {
837 	memset(area, 0, size);
838 }
839 
840 #define BPF_PROG_SIZE_TO_NBITS(size)	(round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
841 
842 static DEFINE_MUTEX(pack_mutex);
843 static LIST_HEAD(pack_list);
844 
845 /* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
846  * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
847  */
848 #ifdef PMD_SIZE
849 #define BPF_PROG_PACK_SIZE (PMD_SIZE * num_possible_nodes())
850 #else
851 #define BPF_PROG_PACK_SIZE PAGE_SIZE
852 #endif
853 
854 #define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
855 
856 static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
857 {
858 	struct bpf_prog_pack *pack;
859 
860 	pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)),
861 		       GFP_KERNEL);
862 	if (!pack)
863 		return NULL;
864 	pack->ptr = module_alloc(BPF_PROG_PACK_SIZE);
865 	if (!pack->ptr) {
866 		kfree(pack);
867 		return NULL;
868 	}
869 	bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
870 	bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
871 	list_add_tail(&pack->list, &pack_list);
872 
873 	set_vm_flush_reset_perms(pack->ptr);
874 	set_memory_rox((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE);
875 	return pack;
876 }
877 
878 void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
879 {
880 	unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
881 	struct bpf_prog_pack *pack;
882 	unsigned long pos;
883 	void *ptr = NULL;
884 
885 	mutex_lock(&pack_mutex);
886 	if (size > BPF_PROG_PACK_SIZE) {
887 		size = round_up(size, PAGE_SIZE);
888 		ptr = module_alloc(size);
889 		if (ptr) {
890 			bpf_fill_ill_insns(ptr, size);
891 			set_vm_flush_reset_perms(ptr);
892 			set_memory_rox((unsigned long)ptr, size / PAGE_SIZE);
893 		}
894 		goto out;
895 	}
896 	list_for_each_entry(pack, &pack_list, list) {
897 		pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
898 						 nbits, 0);
899 		if (pos < BPF_PROG_CHUNK_COUNT)
900 			goto found_free_area;
901 	}
902 
903 	pack = alloc_new_pack(bpf_fill_ill_insns);
904 	if (!pack)
905 		goto out;
906 
907 	pos = 0;
908 
909 found_free_area:
910 	bitmap_set(pack->bitmap, pos, nbits);
911 	ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
912 
913 out:
914 	mutex_unlock(&pack_mutex);
915 	return ptr;
916 }
917 
918 void bpf_prog_pack_free(struct bpf_binary_header *hdr)
919 {
920 	struct bpf_prog_pack *pack = NULL, *tmp;
921 	unsigned int nbits;
922 	unsigned long pos;
923 
924 	mutex_lock(&pack_mutex);
925 	if (hdr->size > BPF_PROG_PACK_SIZE) {
926 		module_memfree(hdr);
927 		goto out;
928 	}
929 
930 	list_for_each_entry(tmp, &pack_list, list) {
931 		if ((void *)hdr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > (void *)hdr) {
932 			pack = tmp;
933 			break;
934 		}
935 	}
936 
937 	if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
938 		goto out;
939 
940 	nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size);
941 	pos = ((unsigned long)hdr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
942 
943 	WARN_ONCE(bpf_arch_text_invalidate(hdr, hdr->size),
944 		  "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
945 
946 	bitmap_clear(pack->bitmap, pos, nbits);
947 	if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
948 				       BPF_PROG_CHUNK_COUNT, 0) == 0) {
949 		list_del(&pack->list);
950 		module_memfree(pack->ptr);
951 		kfree(pack);
952 	}
953 out:
954 	mutex_unlock(&pack_mutex);
955 }
956 
957 static atomic_long_t bpf_jit_current;
958 
959 /* Can be overridden by an arch's JIT compiler if it has a custom,
960  * dedicated BPF backend memory area, or if neither of the two
961  * below apply.
962  */
963 u64 __weak bpf_jit_alloc_exec_limit(void)
964 {
965 #if defined(MODULES_VADDR)
966 	return MODULES_END - MODULES_VADDR;
967 #else
968 	return VMALLOC_END - VMALLOC_START;
969 #endif
970 }
971 
972 static int __init bpf_jit_charge_init(void)
973 {
974 	/* Only used as heuristic here to derive limit. */
975 	bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
976 	bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 1,
977 					    PAGE_SIZE), LONG_MAX);
978 	return 0;
979 }
980 pure_initcall(bpf_jit_charge_init);
981 
982 int bpf_jit_charge_modmem(u32 size)
983 {
984 	if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
985 		if (!bpf_capable()) {
986 			atomic_long_sub(size, &bpf_jit_current);
987 			return -EPERM;
988 		}
989 	}
990 
991 	return 0;
992 }
993 
994 void bpf_jit_uncharge_modmem(u32 size)
995 {
996 	atomic_long_sub(size, &bpf_jit_current);
997 }
998 
999 void *__weak bpf_jit_alloc_exec(unsigned long size)
1000 {
1001 	return module_alloc(size);
1002 }
1003 
1004 void __weak bpf_jit_free_exec(void *addr)
1005 {
1006 	module_memfree(addr);
1007 }
1008 
1009 struct bpf_binary_header *
1010 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1011 		     unsigned int alignment,
1012 		     bpf_jit_fill_hole_t bpf_fill_ill_insns)
1013 {
1014 	struct bpf_binary_header *hdr;
1015 	u32 size, hole, start;
1016 
1017 	WARN_ON_ONCE(!is_power_of_2(alignment) ||
1018 		     alignment > BPF_IMAGE_ALIGNMENT);
1019 
1020 	/* Most of BPF filters are really small, but if some of them
1021 	 * fill a page, allow at least 128 extra bytes to insert a
1022 	 * random section of illegal instructions.
1023 	 */
1024 	size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
1025 
1026 	if (bpf_jit_charge_modmem(size))
1027 		return NULL;
1028 	hdr = bpf_jit_alloc_exec(size);
1029 	if (!hdr) {
1030 		bpf_jit_uncharge_modmem(size);
1031 		return NULL;
1032 	}
1033 
1034 	/* Fill space with illegal/arch-dep instructions. */
1035 	bpf_fill_ill_insns(hdr, size);
1036 
1037 	hdr->size = size;
1038 	hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
1039 		     PAGE_SIZE - sizeof(*hdr));
1040 	start = get_random_u32_below(hole) & ~(alignment - 1);
1041 
1042 	/* Leave a random number of instructions before BPF code. */
1043 	*image_ptr = &hdr->image[start];
1044 
1045 	return hdr;
1046 }
1047 
1048 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
1049 {
1050 	u32 size = hdr->size;
1051 
1052 	bpf_jit_free_exec(hdr);
1053 	bpf_jit_uncharge_modmem(size);
1054 }
1055 
1056 /* Allocate jit binary from bpf_prog_pack allocator.
1057  * Since the allocated memory is RO+X, the JIT engine cannot write directly
1058  * to the memory. To solve this problem, a RW buffer is also allocated at
1059  * as the same time. The JIT engine should calculate offsets based on the
1060  * RO memory address, but write JITed program to the RW buffer. Once the
1061  * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
1062  * the JITed program to the RO memory.
1063  */
1064 struct bpf_binary_header *
1065 bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
1066 			  unsigned int alignment,
1067 			  struct bpf_binary_header **rw_header,
1068 			  u8 **rw_image,
1069 			  bpf_jit_fill_hole_t bpf_fill_ill_insns)
1070 {
1071 	struct bpf_binary_header *ro_header;
1072 	u32 size, hole, start;
1073 
1074 	WARN_ON_ONCE(!is_power_of_2(alignment) ||
1075 		     alignment > BPF_IMAGE_ALIGNMENT);
1076 
1077 	/* add 16 bytes for a random section of illegal instructions */
1078 	size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
1079 
1080 	if (bpf_jit_charge_modmem(size))
1081 		return NULL;
1082 	ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns);
1083 	if (!ro_header) {
1084 		bpf_jit_uncharge_modmem(size);
1085 		return NULL;
1086 	}
1087 
1088 	*rw_header = kvmalloc(size, GFP_KERNEL);
1089 	if (!*rw_header) {
1090 		bpf_arch_text_copy(&ro_header->size, &size, sizeof(size));
1091 		bpf_prog_pack_free(ro_header);
1092 		bpf_jit_uncharge_modmem(size);
1093 		return NULL;
1094 	}
1095 
1096 	/* Fill space with illegal/arch-dep instructions. */
1097 	bpf_fill_ill_insns(*rw_header, size);
1098 	(*rw_header)->size = size;
1099 
1100 	hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
1101 		     BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
1102 	start = get_random_u32_below(hole) & ~(alignment - 1);
1103 
1104 	*image_ptr = &ro_header->image[start];
1105 	*rw_image = &(*rw_header)->image[start];
1106 
1107 	return ro_header;
1108 }
1109 
1110 /* Copy JITed text from rw_header to its final location, the ro_header. */
1111 int bpf_jit_binary_pack_finalize(struct bpf_prog *prog,
1112 				 struct bpf_binary_header *ro_header,
1113 				 struct bpf_binary_header *rw_header)
1114 {
1115 	void *ptr;
1116 
1117 	ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
1118 
1119 	kvfree(rw_header);
1120 
1121 	if (IS_ERR(ptr)) {
1122 		bpf_prog_pack_free(ro_header);
1123 		return PTR_ERR(ptr);
1124 	}
1125 	return 0;
1126 }
1127 
1128 /* bpf_jit_binary_pack_free is called in two different scenarios:
1129  *   1) when the program is freed after;
1130  *   2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
1131  * For case 2), we need to free both the RO memory and the RW buffer.
1132  *
1133  * bpf_jit_binary_pack_free requires proper ro_header->size. However,
1134  * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
1135  * must be set with either bpf_jit_binary_pack_finalize (normal path) or
1136  * bpf_arch_text_copy (when jit fails).
1137  */
1138 void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
1139 			      struct bpf_binary_header *rw_header)
1140 {
1141 	u32 size = ro_header->size;
1142 
1143 	bpf_prog_pack_free(ro_header);
1144 	kvfree(rw_header);
1145 	bpf_jit_uncharge_modmem(size);
1146 }
1147 
1148 struct bpf_binary_header *
1149 bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
1150 {
1151 	unsigned long real_start = (unsigned long)fp->bpf_func;
1152 	unsigned long addr;
1153 
1154 	addr = real_start & BPF_PROG_CHUNK_MASK;
1155 	return (void *)addr;
1156 }
1157 
1158 static inline struct bpf_binary_header *
1159 bpf_jit_binary_hdr(const struct bpf_prog *fp)
1160 {
1161 	unsigned long real_start = (unsigned long)fp->bpf_func;
1162 	unsigned long addr;
1163 
1164 	addr = real_start & PAGE_MASK;
1165 	return (void *)addr;
1166 }
1167 
1168 /* This symbol is only overridden by archs that have different
1169  * requirements than the usual eBPF JITs, f.e. when they only
1170  * implement cBPF JIT, do not set images read-only, etc.
1171  */
1172 void __weak bpf_jit_free(struct bpf_prog *fp)
1173 {
1174 	if (fp->jited) {
1175 		struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
1176 
1177 		bpf_jit_binary_free(hdr);
1178 		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
1179 	}
1180 
1181 	bpf_prog_unlock_free(fp);
1182 }
1183 
1184 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1185 			  const struct bpf_insn *insn, bool extra_pass,
1186 			  u64 *func_addr, bool *func_addr_fixed)
1187 {
1188 	s16 off = insn->off;
1189 	s32 imm = insn->imm;
1190 	u8 *addr;
1191 	int err;
1192 
1193 	*func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1194 	if (!*func_addr_fixed) {
1195 		/* Place-holder address till the last pass has collected
1196 		 * all addresses for JITed subprograms in which case we
1197 		 * can pick them up from prog->aux.
1198 		 */
1199 		if (!extra_pass)
1200 			addr = NULL;
1201 		else if (prog->aux->func &&
1202 			 off >= 0 && off < prog->aux->func_cnt)
1203 			addr = (u8 *)prog->aux->func[off]->bpf_func;
1204 		else
1205 			return -EINVAL;
1206 	} else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL &&
1207 		   bpf_jit_supports_far_kfunc_call()) {
1208 		err = bpf_get_kfunc_addr(prog, insn->imm, insn->off, &addr);
1209 		if (err)
1210 			return err;
1211 	} else {
1212 		/* Address of a BPF helper call. Since part of the core
1213 		 * kernel, it's always at a fixed location. __bpf_call_base
1214 		 * and the helper with imm relative to it are both in core
1215 		 * kernel.
1216 		 */
1217 		addr = (u8 *)__bpf_call_base + imm;
1218 	}
1219 
1220 	*func_addr = (unsigned long)addr;
1221 	return 0;
1222 }
1223 
1224 static int bpf_jit_blind_insn(const struct bpf_insn *from,
1225 			      const struct bpf_insn *aux,
1226 			      struct bpf_insn *to_buff,
1227 			      bool emit_zext)
1228 {
1229 	struct bpf_insn *to = to_buff;
1230 	u32 imm_rnd = get_random_u32();
1231 	s16 off;
1232 
1233 	BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
1234 	BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
1235 
1236 	/* Constraints on AX register:
1237 	 *
1238 	 * AX register is inaccessible from user space. It is mapped in
1239 	 * all JITs, and used here for constant blinding rewrites. It is
1240 	 * typically "stateless" meaning its contents are only valid within
1241 	 * the executed instruction, but not across several instructions.
1242 	 * There are a few exceptions however which are further detailed
1243 	 * below.
1244 	 *
1245 	 * Constant blinding is only used by JITs, not in the interpreter.
1246 	 * The interpreter uses AX in some occasions as a local temporary
1247 	 * register e.g. in DIV or MOD instructions.
1248 	 *
1249 	 * In restricted circumstances, the verifier can also use the AX
1250 	 * register for rewrites as long as they do not interfere with
1251 	 * the above cases!
1252 	 */
1253 	if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1254 		goto out;
1255 
1256 	if (from->imm == 0 &&
1257 	    (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
1258 	     from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1259 		*to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1260 		goto out;
1261 	}
1262 
1263 	switch (from->code) {
1264 	case BPF_ALU | BPF_ADD | BPF_K:
1265 	case BPF_ALU | BPF_SUB | BPF_K:
1266 	case BPF_ALU | BPF_AND | BPF_K:
1267 	case BPF_ALU | BPF_OR  | BPF_K:
1268 	case BPF_ALU | BPF_XOR | BPF_K:
1269 	case BPF_ALU | BPF_MUL | BPF_K:
1270 	case BPF_ALU | BPF_MOV | BPF_K:
1271 	case BPF_ALU | BPF_DIV | BPF_K:
1272 	case BPF_ALU | BPF_MOD | BPF_K:
1273 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1274 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1275 		*to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
1276 		break;
1277 
1278 	case BPF_ALU64 | BPF_ADD | BPF_K:
1279 	case BPF_ALU64 | BPF_SUB | BPF_K:
1280 	case BPF_ALU64 | BPF_AND | BPF_K:
1281 	case BPF_ALU64 | BPF_OR  | BPF_K:
1282 	case BPF_ALU64 | BPF_XOR | BPF_K:
1283 	case BPF_ALU64 | BPF_MUL | BPF_K:
1284 	case BPF_ALU64 | BPF_MOV | BPF_K:
1285 	case BPF_ALU64 | BPF_DIV | BPF_K:
1286 	case BPF_ALU64 | BPF_MOD | BPF_K:
1287 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1288 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1289 		*to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
1290 		break;
1291 
1292 	case BPF_JMP | BPF_JEQ  | BPF_K:
1293 	case BPF_JMP | BPF_JNE  | BPF_K:
1294 	case BPF_JMP | BPF_JGT  | BPF_K:
1295 	case BPF_JMP | BPF_JLT  | BPF_K:
1296 	case BPF_JMP | BPF_JGE  | BPF_K:
1297 	case BPF_JMP | BPF_JLE  | BPF_K:
1298 	case BPF_JMP | BPF_JSGT | BPF_K:
1299 	case BPF_JMP | BPF_JSLT | BPF_K:
1300 	case BPF_JMP | BPF_JSGE | BPF_K:
1301 	case BPF_JMP | BPF_JSLE | BPF_K:
1302 	case BPF_JMP | BPF_JSET | BPF_K:
1303 		/* Accommodate for extra offset in case of a backjump. */
1304 		off = from->off;
1305 		if (off < 0)
1306 			off -= 2;
1307 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1308 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1309 		*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1310 		break;
1311 
1312 	case BPF_JMP32 | BPF_JEQ  | BPF_K:
1313 	case BPF_JMP32 | BPF_JNE  | BPF_K:
1314 	case BPF_JMP32 | BPF_JGT  | BPF_K:
1315 	case BPF_JMP32 | BPF_JLT  | BPF_K:
1316 	case BPF_JMP32 | BPF_JGE  | BPF_K:
1317 	case BPF_JMP32 | BPF_JLE  | BPF_K:
1318 	case BPF_JMP32 | BPF_JSGT | BPF_K:
1319 	case BPF_JMP32 | BPF_JSLT | BPF_K:
1320 	case BPF_JMP32 | BPF_JSGE | BPF_K:
1321 	case BPF_JMP32 | BPF_JSLE | BPF_K:
1322 	case BPF_JMP32 | BPF_JSET | BPF_K:
1323 		/* Accommodate for extra offset in case of a backjump. */
1324 		off = from->off;
1325 		if (off < 0)
1326 			off -= 2;
1327 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1328 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1329 		*to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1330 				      off);
1331 		break;
1332 
1333 	case BPF_LD | BPF_IMM | BPF_DW:
1334 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1335 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1336 		*to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1337 		*to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1338 		break;
1339 	case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1340 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1341 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1342 		if (emit_zext)
1343 			*to++ = BPF_ZEXT_REG(BPF_REG_AX);
1344 		*to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
1345 		break;
1346 
1347 	case BPF_ST | BPF_MEM | BPF_DW:
1348 	case BPF_ST | BPF_MEM | BPF_W:
1349 	case BPF_ST | BPF_MEM | BPF_H:
1350 	case BPF_ST | BPF_MEM | BPF_B:
1351 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1352 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1353 		*to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1354 		break;
1355 	}
1356 out:
1357 	return to - to_buff;
1358 }
1359 
1360 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1361 					      gfp_t gfp_extra_flags)
1362 {
1363 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1364 	struct bpf_prog *fp;
1365 
1366 	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1367 	if (fp != NULL) {
1368 		/* aux->prog still points to the fp_other one, so
1369 		 * when promoting the clone to the real program,
1370 		 * this still needs to be adapted.
1371 		 */
1372 		memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1373 	}
1374 
1375 	return fp;
1376 }
1377 
1378 static void bpf_prog_clone_free(struct bpf_prog *fp)
1379 {
1380 	/* aux was stolen by the other clone, so we cannot free
1381 	 * it from this path! It will be freed eventually by the
1382 	 * other program on release.
1383 	 *
1384 	 * At this point, we don't need a deferred release since
1385 	 * clone is guaranteed to not be locked.
1386 	 */
1387 	fp->aux = NULL;
1388 	fp->stats = NULL;
1389 	fp->active = NULL;
1390 	__bpf_prog_free(fp);
1391 }
1392 
1393 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1394 {
1395 	/* We have to repoint aux->prog to self, as we don't
1396 	 * know whether fp here is the clone or the original.
1397 	 */
1398 	fp->aux->prog = fp;
1399 	bpf_prog_clone_free(fp_other);
1400 }
1401 
1402 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1403 {
1404 	struct bpf_insn insn_buff[16], aux[2];
1405 	struct bpf_prog *clone, *tmp;
1406 	int insn_delta, insn_cnt;
1407 	struct bpf_insn *insn;
1408 	int i, rewritten;
1409 
1410 	if (!prog->blinding_requested || prog->blinded)
1411 		return prog;
1412 
1413 	clone = bpf_prog_clone_create(prog, GFP_USER);
1414 	if (!clone)
1415 		return ERR_PTR(-ENOMEM);
1416 
1417 	insn_cnt = clone->len;
1418 	insn = clone->insnsi;
1419 
1420 	for (i = 0; i < insn_cnt; i++, insn++) {
1421 		if (bpf_pseudo_func(insn)) {
1422 			/* ld_imm64 with an address of bpf subprog is not
1423 			 * a user controlled constant. Don't randomize it,
1424 			 * since it will conflict with jit_subprogs() logic.
1425 			 */
1426 			insn++;
1427 			i++;
1428 			continue;
1429 		}
1430 
1431 		/* We temporarily need to hold the original ld64 insn
1432 		 * so that we can still access the first part in the
1433 		 * second blinding run.
1434 		 */
1435 		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1436 		    insn[1].code == 0)
1437 			memcpy(aux, insn, sizeof(aux));
1438 
1439 		rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1440 						clone->aux->verifier_zext);
1441 		if (!rewritten)
1442 			continue;
1443 
1444 		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1445 		if (IS_ERR(tmp)) {
1446 			/* Patching may have repointed aux->prog during
1447 			 * realloc from the original one, so we need to
1448 			 * fix it up here on error.
1449 			 */
1450 			bpf_jit_prog_release_other(prog, clone);
1451 			return tmp;
1452 		}
1453 
1454 		clone = tmp;
1455 		insn_delta = rewritten - 1;
1456 
1457 		/* Walk new program and skip insns we just inserted. */
1458 		insn = clone->insnsi + i + insn_delta;
1459 		insn_cnt += insn_delta;
1460 		i        += insn_delta;
1461 	}
1462 
1463 	clone->blinded = 1;
1464 	return clone;
1465 }
1466 #endif /* CONFIG_BPF_JIT */
1467 
1468 /* Base function for offset calculation. Needs to go into .text section,
1469  * therefore keeping it non-static as well; will also be used by JITs
1470  * anyway later on, so do not let the compiler omit it. This also needs
1471  * to go into kallsyms for correlation from e.g. bpftool, so naming
1472  * must not change.
1473  */
1474 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1475 {
1476 	return 0;
1477 }
1478 EXPORT_SYMBOL_GPL(__bpf_call_base);
1479 
1480 /* All UAPI available opcodes. */
1481 #define BPF_INSN_MAP(INSN_2, INSN_3)		\
1482 	/* 32 bit ALU operations. */		\
1483 	/*   Register based. */			\
1484 	INSN_3(ALU, ADD,  X),			\
1485 	INSN_3(ALU, SUB,  X),			\
1486 	INSN_3(ALU, AND,  X),			\
1487 	INSN_3(ALU, OR,   X),			\
1488 	INSN_3(ALU, LSH,  X),			\
1489 	INSN_3(ALU, RSH,  X),			\
1490 	INSN_3(ALU, XOR,  X),			\
1491 	INSN_3(ALU, MUL,  X),			\
1492 	INSN_3(ALU, MOV,  X),			\
1493 	INSN_3(ALU, ARSH, X),			\
1494 	INSN_3(ALU, DIV,  X),			\
1495 	INSN_3(ALU, MOD,  X),			\
1496 	INSN_2(ALU, NEG),			\
1497 	INSN_3(ALU, END, TO_BE),		\
1498 	INSN_3(ALU, END, TO_LE),		\
1499 	/*   Immediate based. */		\
1500 	INSN_3(ALU, ADD,  K),			\
1501 	INSN_3(ALU, SUB,  K),			\
1502 	INSN_3(ALU, AND,  K),			\
1503 	INSN_3(ALU, OR,   K),			\
1504 	INSN_3(ALU, LSH,  K),			\
1505 	INSN_3(ALU, RSH,  K),			\
1506 	INSN_3(ALU, XOR,  K),			\
1507 	INSN_3(ALU, MUL,  K),			\
1508 	INSN_3(ALU, MOV,  K),			\
1509 	INSN_3(ALU, ARSH, K),			\
1510 	INSN_3(ALU, DIV,  K),			\
1511 	INSN_3(ALU, MOD,  K),			\
1512 	/* 64 bit ALU operations. */		\
1513 	/*   Register based. */			\
1514 	INSN_3(ALU64, ADD,  X),			\
1515 	INSN_3(ALU64, SUB,  X),			\
1516 	INSN_3(ALU64, AND,  X),			\
1517 	INSN_3(ALU64, OR,   X),			\
1518 	INSN_3(ALU64, LSH,  X),			\
1519 	INSN_3(ALU64, RSH,  X),			\
1520 	INSN_3(ALU64, XOR,  X),			\
1521 	INSN_3(ALU64, MUL,  X),			\
1522 	INSN_3(ALU64, MOV,  X),			\
1523 	INSN_3(ALU64, ARSH, X),			\
1524 	INSN_3(ALU64, DIV,  X),			\
1525 	INSN_3(ALU64, MOD,  X),			\
1526 	INSN_2(ALU64, NEG),			\
1527 	INSN_3(ALU64, END, TO_LE),		\
1528 	/*   Immediate based. */		\
1529 	INSN_3(ALU64, ADD,  K),			\
1530 	INSN_3(ALU64, SUB,  K),			\
1531 	INSN_3(ALU64, AND,  K),			\
1532 	INSN_3(ALU64, OR,   K),			\
1533 	INSN_3(ALU64, LSH,  K),			\
1534 	INSN_3(ALU64, RSH,  K),			\
1535 	INSN_3(ALU64, XOR,  K),			\
1536 	INSN_3(ALU64, MUL,  K),			\
1537 	INSN_3(ALU64, MOV,  K),			\
1538 	INSN_3(ALU64, ARSH, K),			\
1539 	INSN_3(ALU64, DIV,  K),			\
1540 	INSN_3(ALU64, MOD,  K),			\
1541 	/* Call instruction. */			\
1542 	INSN_2(JMP, CALL),			\
1543 	/* Exit instruction. */			\
1544 	INSN_2(JMP, EXIT),			\
1545 	/* 32-bit Jump instructions. */		\
1546 	/*   Register based. */			\
1547 	INSN_3(JMP32, JEQ,  X),			\
1548 	INSN_3(JMP32, JNE,  X),			\
1549 	INSN_3(JMP32, JGT,  X),			\
1550 	INSN_3(JMP32, JLT,  X),			\
1551 	INSN_3(JMP32, JGE,  X),			\
1552 	INSN_3(JMP32, JLE,  X),			\
1553 	INSN_3(JMP32, JSGT, X),			\
1554 	INSN_3(JMP32, JSLT, X),			\
1555 	INSN_3(JMP32, JSGE, X),			\
1556 	INSN_3(JMP32, JSLE, X),			\
1557 	INSN_3(JMP32, JSET, X),			\
1558 	/*   Immediate based. */		\
1559 	INSN_3(JMP32, JEQ,  K),			\
1560 	INSN_3(JMP32, JNE,  K),			\
1561 	INSN_3(JMP32, JGT,  K),			\
1562 	INSN_3(JMP32, JLT,  K),			\
1563 	INSN_3(JMP32, JGE,  K),			\
1564 	INSN_3(JMP32, JLE,  K),			\
1565 	INSN_3(JMP32, JSGT, K),			\
1566 	INSN_3(JMP32, JSLT, K),			\
1567 	INSN_3(JMP32, JSGE, K),			\
1568 	INSN_3(JMP32, JSLE, K),			\
1569 	INSN_3(JMP32, JSET, K),			\
1570 	/* Jump instructions. */		\
1571 	/*   Register based. */			\
1572 	INSN_3(JMP, JEQ,  X),			\
1573 	INSN_3(JMP, JNE,  X),			\
1574 	INSN_3(JMP, JGT,  X),			\
1575 	INSN_3(JMP, JLT,  X),			\
1576 	INSN_3(JMP, JGE,  X),			\
1577 	INSN_3(JMP, JLE,  X),			\
1578 	INSN_3(JMP, JSGT, X),			\
1579 	INSN_3(JMP, JSLT, X),			\
1580 	INSN_3(JMP, JSGE, X),			\
1581 	INSN_3(JMP, JSLE, X),			\
1582 	INSN_3(JMP, JSET, X),			\
1583 	/*   Immediate based. */		\
1584 	INSN_3(JMP, JEQ,  K),			\
1585 	INSN_3(JMP, JNE,  K),			\
1586 	INSN_3(JMP, JGT,  K),			\
1587 	INSN_3(JMP, JLT,  K),			\
1588 	INSN_3(JMP, JGE,  K),			\
1589 	INSN_3(JMP, JLE,  K),			\
1590 	INSN_3(JMP, JSGT, K),			\
1591 	INSN_3(JMP, JSLT, K),			\
1592 	INSN_3(JMP, JSGE, K),			\
1593 	INSN_3(JMP, JSLE, K),			\
1594 	INSN_3(JMP, JSET, K),			\
1595 	INSN_2(JMP, JA),			\
1596 	/* Store instructions. */		\
1597 	/*   Register based. */			\
1598 	INSN_3(STX, MEM,  B),			\
1599 	INSN_3(STX, MEM,  H),			\
1600 	INSN_3(STX, MEM,  W),			\
1601 	INSN_3(STX, MEM,  DW),			\
1602 	INSN_3(STX, ATOMIC, W),			\
1603 	INSN_3(STX, ATOMIC, DW),		\
1604 	/*   Immediate based. */		\
1605 	INSN_3(ST, MEM, B),			\
1606 	INSN_3(ST, MEM, H),			\
1607 	INSN_3(ST, MEM, W),			\
1608 	INSN_3(ST, MEM, DW),			\
1609 	/* Load instructions. */		\
1610 	/*   Register based. */			\
1611 	INSN_3(LDX, MEM, B),			\
1612 	INSN_3(LDX, MEM, H),			\
1613 	INSN_3(LDX, MEM, W),			\
1614 	INSN_3(LDX, MEM, DW),			\
1615 	INSN_3(LDX, MEMSX, B),			\
1616 	INSN_3(LDX, MEMSX, H),			\
1617 	INSN_3(LDX, MEMSX, W),			\
1618 	/*   Immediate based. */		\
1619 	INSN_3(LD, IMM, DW)
1620 
1621 bool bpf_opcode_in_insntable(u8 code)
1622 {
1623 #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
1624 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1625 	static const bool public_insntable[256] = {
1626 		[0 ... 255] = false,
1627 		/* Now overwrite non-defaults ... */
1628 		BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1629 		/* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1630 		[BPF_LD | BPF_ABS | BPF_B] = true,
1631 		[BPF_LD | BPF_ABS | BPF_H] = true,
1632 		[BPF_LD | BPF_ABS | BPF_W] = true,
1633 		[BPF_LD | BPF_IND | BPF_B] = true,
1634 		[BPF_LD | BPF_IND | BPF_H] = true,
1635 		[BPF_LD | BPF_IND | BPF_W] = true,
1636 	};
1637 #undef BPF_INSN_3_TBL
1638 #undef BPF_INSN_2_TBL
1639 	return public_insntable[code];
1640 }
1641 
1642 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1643 u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
1644 {
1645 	memset(dst, 0, size);
1646 	return -EFAULT;
1647 }
1648 
1649 /**
1650  *	___bpf_prog_run - run eBPF program on a given context
1651  *	@regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1652  *	@insn: is the array of eBPF instructions
1653  *
1654  * Decode and execute eBPF instructions.
1655  *
1656  * Return: whatever value is in %BPF_R0 at program exit
1657  */
1658 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1659 {
1660 #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
1661 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1662 	static const void * const jumptable[256] __annotate_jump_table = {
1663 		[0 ... 255] = &&default_label,
1664 		/* Now overwrite non-defaults ... */
1665 		BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1666 		/* Non-UAPI available opcodes. */
1667 		[BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1668 		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1669 		[BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
1670 		[BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1671 		[BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1672 		[BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1673 		[BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1674 		[BPF_LDX | BPF_PROBE_MEMSX | BPF_B] = &&LDX_PROBE_MEMSX_B,
1675 		[BPF_LDX | BPF_PROBE_MEMSX | BPF_H] = &&LDX_PROBE_MEMSX_H,
1676 		[BPF_LDX | BPF_PROBE_MEMSX | BPF_W] = &&LDX_PROBE_MEMSX_W,
1677 	};
1678 #undef BPF_INSN_3_LBL
1679 #undef BPF_INSN_2_LBL
1680 	u32 tail_call_cnt = 0;
1681 
1682 #define CONT	 ({ insn++; goto select_insn; })
1683 #define CONT_JMP ({ insn++; goto select_insn; })
1684 
1685 select_insn:
1686 	goto *jumptable[insn->code];
1687 
1688 	/* Explicitly mask the register-based shift amounts with 63 or 31
1689 	 * to avoid undefined behavior. Normally this won't affect the
1690 	 * generated code, for example, in case of native 64 bit archs such
1691 	 * as x86-64 or arm64, the compiler is optimizing the AND away for
1692 	 * the interpreter. In case of JITs, each of the JIT backends compiles
1693 	 * the BPF shift operations to machine instructions which produce
1694 	 * implementation-defined results in such a case; the resulting
1695 	 * contents of the register may be arbitrary, but program behaviour
1696 	 * as a whole remains defined. In other words, in case of JIT backends,
1697 	 * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1698 	 */
1699 	/* ALU (shifts) */
1700 #define SHT(OPCODE, OP)					\
1701 	ALU64_##OPCODE##_X:				\
1702 		DST = DST OP (SRC & 63);		\
1703 		CONT;					\
1704 	ALU_##OPCODE##_X:				\
1705 		DST = (u32) DST OP ((u32) SRC & 31);	\
1706 		CONT;					\
1707 	ALU64_##OPCODE##_K:				\
1708 		DST = DST OP IMM;			\
1709 		CONT;					\
1710 	ALU_##OPCODE##_K:				\
1711 		DST = (u32) DST OP (u32) IMM;		\
1712 		CONT;
1713 	/* ALU (rest) */
1714 #define ALU(OPCODE, OP)					\
1715 	ALU64_##OPCODE##_X:				\
1716 		DST = DST OP SRC;			\
1717 		CONT;					\
1718 	ALU_##OPCODE##_X:				\
1719 		DST = (u32) DST OP (u32) SRC;		\
1720 		CONT;					\
1721 	ALU64_##OPCODE##_K:				\
1722 		DST = DST OP IMM;			\
1723 		CONT;					\
1724 	ALU_##OPCODE##_K:				\
1725 		DST = (u32) DST OP (u32) IMM;		\
1726 		CONT;
1727 	ALU(ADD,  +)
1728 	ALU(SUB,  -)
1729 	ALU(AND,  &)
1730 	ALU(OR,   |)
1731 	ALU(XOR,  ^)
1732 	ALU(MUL,  *)
1733 	SHT(LSH, <<)
1734 	SHT(RSH, >>)
1735 #undef SHT
1736 #undef ALU
1737 	ALU_NEG:
1738 		DST = (u32) -DST;
1739 		CONT;
1740 	ALU64_NEG:
1741 		DST = -DST;
1742 		CONT;
1743 	ALU_MOV_X:
1744 		switch (OFF) {
1745 		case 0:
1746 			DST = (u32) SRC;
1747 			break;
1748 		case 8:
1749 			DST = (u32)(s8) SRC;
1750 			break;
1751 		case 16:
1752 			DST = (u32)(s16) SRC;
1753 			break;
1754 		}
1755 		CONT;
1756 	ALU_MOV_K:
1757 		DST = (u32) IMM;
1758 		CONT;
1759 	ALU64_MOV_X:
1760 		switch (OFF) {
1761 		case 0:
1762 			DST = SRC;
1763 			break;
1764 		case 8:
1765 			DST = (s8) SRC;
1766 			break;
1767 		case 16:
1768 			DST = (s16) SRC;
1769 			break;
1770 		case 32:
1771 			DST = (s32) SRC;
1772 			break;
1773 		}
1774 		CONT;
1775 	ALU64_MOV_K:
1776 		DST = IMM;
1777 		CONT;
1778 	LD_IMM_DW:
1779 		DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1780 		insn++;
1781 		CONT;
1782 	ALU_ARSH_X:
1783 		DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1784 		CONT;
1785 	ALU_ARSH_K:
1786 		DST = (u64) (u32) (((s32) DST) >> IMM);
1787 		CONT;
1788 	ALU64_ARSH_X:
1789 		(*(s64 *) &DST) >>= (SRC & 63);
1790 		CONT;
1791 	ALU64_ARSH_K:
1792 		(*(s64 *) &DST) >>= IMM;
1793 		CONT;
1794 	ALU64_MOD_X:
1795 		div64_u64_rem(DST, SRC, &AX);
1796 		DST = AX;
1797 		CONT;
1798 	ALU_MOD_X:
1799 		AX = (u32) DST;
1800 		DST = do_div(AX, (u32) SRC);
1801 		CONT;
1802 	ALU64_MOD_K:
1803 		div64_u64_rem(DST, IMM, &AX);
1804 		DST = AX;
1805 		CONT;
1806 	ALU_MOD_K:
1807 		AX = (u32) DST;
1808 		DST = do_div(AX, (u32) IMM);
1809 		CONT;
1810 	ALU64_DIV_X:
1811 		DST = div64_u64(DST, SRC);
1812 		CONT;
1813 	ALU_DIV_X:
1814 		AX = (u32) DST;
1815 		do_div(AX, (u32) SRC);
1816 		DST = (u32) AX;
1817 		CONT;
1818 	ALU64_DIV_K:
1819 		DST = div64_u64(DST, IMM);
1820 		CONT;
1821 	ALU_DIV_K:
1822 		AX = (u32) DST;
1823 		do_div(AX, (u32) IMM);
1824 		DST = (u32) AX;
1825 		CONT;
1826 	ALU_END_TO_BE:
1827 		switch (IMM) {
1828 		case 16:
1829 			DST = (__force u16) cpu_to_be16(DST);
1830 			break;
1831 		case 32:
1832 			DST = (__force u32) cpu_to_be32(DST);
1833 			break;
1834 		case 64:
1835 			DST = (__force u64) cpu_to_be64(DST);
1836 			break;
1837 		}
1838 		CONT;
1839 	ALU_END_TO_LE:
1840 		switch (IMM) {
1841 		case 16:
1842 			DST = (__force u16) cpu_to_le16(DST);
1843 			break;
1844 		case 32:
1845 			DST = (__force u32) cpu_to_le32(DST);
1846 			break;
1847 		case 64:
1848 			DST = (__force u64) cpu_to_le64(DST);
1849 			break;
1850 		}
1851 		CONT;
1852 	ALU64_END_TO_LE:
1853 		switch (IMM) {
1854 		case 16:
1855 			DST = (__force u16) __swab16(DST);
1856 			break;
1857 		case 32:
1858 			DST = (__force u32) __swab32(DST);
1859 			break;
1860 		case 64:
1861 			DST = (__force u64) __swab64(DST);
1862 			break;
1863 		}
1864 		CONT;
1865 
1866 	/* CALL */
1867 	JMP_CALL:
1868 		/* Function call scratches BPF_R1-BPF_R5 registers,
1869 		 * preserves BPF_R6-BPF_R9, and stores return value
1870 		 * into BPF_R0.
1871 		 */
1872 		BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1873 						       BPF_R4, BPF_R5);
1874 		CONT;
1875 
1876 	JMP_CALL_ARGS:
1877 		BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
1878 							    BPF_R3, BPF_R4,
1879 							    BPF_R5,
1880 							    insn + insn->off + 1);
1881 		CONT;
1882 
1883 	JMP_TAIL_CALL: {
1884 		struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1885 		struct bpf_array *array = container_of(map, struct bpf_array, map);
1886 		struct bpf_prog *prog;
1887 		u32 index = BPF_R3;
1888 
1889 		if (unlikely(index >= array->map.max_entries))
1890 			goto out;
1891 
1892 		if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
1893 			goto out;
1894 
1895 		tail_call_cnt++;
1896 
1897 		prog = READ_ONCE(array->ptrs[index]);
1898 		if (!prog)
1899 			goto out;
1900 
1901 		/* ARG1 at this point is guaranteed to point to CTX from
1902 		 * the verifier side due to the fact that the tail call is
1903 		 * handled like a helper, that is, bpf_tail_call_proto,
1904 		 * where arg1_type is ARG_PTR_TO_CTX.
1905 		 */
1906 		insn = prog->insnsi;
1907 		goto select_insn;
1908 out:
1909 		CONT;
1910 	}
1911 	JMP_JA:
1912 		insn += insn->off;
1913 		CONT;
1914 	JMP_EXIT:
1915 		return BPF_R0;
1916 	/* JMP */
1917 #define COND_JMP(SIGN, OPCODE, CMP_OP)				\
1918 	JMP_##OPCODE##_X:					\
1919 		if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {	\
1920 			insn += insn->off;			\
1921 			CONT_JMP;				\
1922 		}						\
1923 		CONT;						\
1924 	JMP32_##OPCODE##_X:					\
1925 		if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {	\
1926 			insn += insn->off;			\
1927 			CONT_JMP;				\
1928 		}						\
1929 		CONT;						\
1930 	JMP_##OPCODE##_K:					\
1931 		if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {	\
1932 			insn += insn->off;			\
1933 			CONT_JMP;				\
1934 		}						\
1935 		CONT;						\
1936 	JMP32_##OPCODE##_K:					\
1937 		if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {	\
1938 			insn += insn->off;			\
1939 			CONT_JMP;				\
1940 		}						\
1941 		CONT;
1942 	COND_JMP(u, JEQ, ==)
1943 	COND_JMP(u, JNE, !=)
1944 	COND_JMP(u, JGT, >)
1945 	COND_JMP(u, JLT, <)
1946 	COND_JMP(u, JGE, >=)
1947 	COND_JMP(u, JLE, <=)
1948 	COND_JMP(u, JSET, &)
1949 	COND_JMP(s, JSGT, >)
1950 	COND_JMP(s, JSLT, <)
1951 	COND_JMP(s, JSGE, >=)
1952 	COND_JMP(s, JSLE, <=)
1953 #undef COND_JMP
1954 	/* ST, STX and LDX*/
1955 	ST_NOSPEC:
1956 		/* Speculation barrier for mitigating Speculative Store Bypass.
1957 		 * In case of arm64, we rely on the firmware mitigation as
1958 		 * controlled via the ssbd kernel parameter. Whenever the
1959 		 * mitigation is enabled, it works for all of the kernel code
1960 		 * with no need to provide any additional instructions here.
1961 		 * In case of x86, we use 'lfence' insn for mitigation. We
1962 		 * reuse preexisting logic from Spectre v1 mitigation that
1963 		 * happens to produce the required code on x86 for v4 as well.
1964 		 */
1965 		barrier_nospec();
1966 		CONT;
1967 #define LDST(SIZEOP, SIZE)						\
1968 	STX_MEM_##SIZEOP:						\
1969 		*(SIZE *)(unsigned long) (DST + insn->off) = SRC;	\
1970 		CONT;							\
1971 	ST_MEM_##SIZEOP:						\
1972 		*(SIZE *)(unsigned long) (DST + insn->off) = IMM;	\
1973 		CONT;							\
1974 	LDX_MEM_##SIZEOP:						\
1975 		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
1976 		CONT;							\
1977 	LDX_PROBE_MEM_##SIZEOP:						\
1978 		bpf_probe_read_kernel(&DST, sizeof(SIZE),		\
1979 				      (const void *)(long) (SRC + insn->off));	\
1980 		DST = *((SIZE *)&DST);					\
1981 		CONT;
1982 
1983 	LDST(B,   u8)
1984 	LDST(H,  u16)
1985 	LDST(W,  u32)
1986 	LDST(DW, u64)
1987 #undef LDST
1988 
1989 #define LDSX(SIZEOP, SIZE)						\
1990 	LDX_MEMSX_##SIZEOP:						\
1991 		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
1992 		CONT;							\
1993 	LDX_PROBE_MEMSX_##SIZEOP:					\
1994 		bpf_probe_read_kernel(&DST, sizeof(SIZE),		\
1995 				      (const void *)(long) (SRC + insn->off));	\
1996 		DST = *((SIZE *)&DST);					\
1997 		CONT;
1998 
1999 	LDSX(B,   s8)
2000 	LDSX(H,  s16)
2001 	LDSX(W,  s32)
2002 #undef LDSX
2003 
2004 #define ATOMIC_ALU_OP(BOP, KOP)						\
2005 		case BOP:						\
2006 			if (BPF_SIZE(insn->code) == BPF_W)		\
2007 				atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
2008 					     (DST + insn->off));	\
2009 			else						\
2010 				atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
2011 					       (DST + insn->off));	\
2012 			break;						\
2013 		case BOP | BPF_FETCH:					\
2014 			if (BPF_SIZE(insn->code) == BPF_W)		\
2015 				SRC = (u32) atomic_fetch_##KOP(		\
2016 					(u32) SRC,			\
2017 					(atomic_t *)(unsigned long) (DST + insn->off)); \
2018 			else						\
2019 				SRC = (u64) atomic64_fetch_##KOP(	\
2020 					(u64) SRC,			\
2021 					(atomic64_t *)(unsigned long) (DST + insn->off)); \
2022 			break;
2023 
2024 	STX_ATOMIC_DW:
2025 	STX_ATOMIC_W:
2026 		switch (IMM) {
2027 		ATOMIC_ALU_OP(BPF_ADD, add)
2028 		ATOMIC_ALU_OP(BPF_AND, and)
2029 		ATOMIC_ALU_OP(BPF_OR, or)
2030 		ATOMIC_ALU_OP(BPF_XOR, xor)
2031 #undef ATOMIC_ALU_OP
2032 
2033 		case BPF_XCHG:
2034 			if (BPF_SIZE(insn->code) == BPF_W)
2035 				SRC = (u32) atomic_xchg(
2036 					(atomic_t *)(unsigned long) (DST + insn->off),
2037 					(u32) SRC);
2038 			else
2039 				SRC = (u64) atomic64_xchg(
2040 					(atomic64_t *)(unsigned long) (DST + insn->off),
2041 					(u64) SRC);
2042 			break;
2043 		case BPF_CMPXCHG:
2044 			if (BPF_SIZE(insn->code) == BPF_W)
2045 				BPF_R0 = (u32) atomic_cmpxchg(
2046 					(atomic_t *)(unsigned long) (DST + insn->off),
2047 					(u32) BPF_R0, (u32) SRC);
2048 			else
2049 				BPF_R0 = (u64) atomic64_cmpxchg(
2050 					(atomic64_t *)(unsigned long) (DST + insn->off),
2051 					(u64) BPF_R0, (u64) SRC);
2052 			break;
2053 
2054 		default:
2055 			goto default_label;
2056 		}
2057 		CONT;
2058 
2059 	default_label:
2060 		/* If we ever reach this, we have a bug somewhere. Die hard here
2061 		 * instead of just returning 0; we could be somewhere in a subprog,
2062 		 * so execution could continue otherwise which we do /not/ want.
2063 		 *
2064 		 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2065 		 */
2066 		pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2067 			insn->code, insn->imm);
2068 		BUG_ON(1);
2069 		return 0;
2070 }
2071 
2072 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2073 #define DEFINE_BPF_PROG_RUN(stack_size) \
2074 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2075 { \
2076 	u64 stack[stack_size / sizeof(u64)]; \
2077 	u64 regs[MAX_BPF_EXT_REG] = {}; \
2078 \
2079 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2080 	ARG1 = (u64) (unsigned long) ctx; \
2081 	return ___bpf_prog_run(regs, insn); \
2082 }
2083 
2084 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2085 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2086 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2087 				      const struct bpf_insn *insn) \
2088 { \
2089 	u64 stack[stack_size / sizeof(u64)]; \
2090 	u64 regs[MAX_BPF_EXT_REG]; \
2091 \
2092 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2093 	BPF_R1 = r1; \
2094 	BPF_R2 = r2; \
2095 	BPF_R3 = r3; \
2096 	BPF_R4 = r4; \
2097 	BPF_R5 = r5; \
2098 	return ___bpf_prog_run(regs, insn); \
2099 }
2100 
2101 #define EVAL1(FN, X) FN(X)
2102 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2103 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2104 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2105 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2106 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2107 
2108 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2109 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2110 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2111 
2112 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2113 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2114 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2115 
2116 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2117 
2118 static unsigned int (*interpreters[])(const void *ctx,
2119 				      const struct bpf_insn *insn) = {
2120 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2121 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2122 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2123 };
2124 #undef PROG_NAME_LIST
2125 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2126 static __maybe_unused
2127 u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2128 			   const struct bpf_insn *insn) = {
2129 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2130 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2131 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2132 };
2133 #undef PROG_NAME_LIST
2134 
2135 #ifdef CONFIG_BPF_SYSCALL
2136 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2137 {
2138 	stack_depth = max_t(u32, stack_depth, 1);
2139 	insn->off = (s16) insn->imm;
2140 	insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
2141 		__bpf_call_base_args;
2142 	insn->code = BPF_JMP | BPF_CALL_ARGS;
2143 }
2144 #endif
2145 #else
2146 static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2147 					 const struct bpf_insn *insn)
2148 {
2149 	/* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2150 	 * is not working properly, so warn about it!
2151 	 */
2152 	WARN_ON_ONCE(1);
2153 	return 0;
2154 }
2155 #endif
2156 
2157 bool bpf_prog_map_compatible(struct bpf_map *map,
2158 			     const struct bpf_prog *fp)
2159 {
2160 	enum bpf_prog_type prog_type = resolve_prog_type(fp);
2161 	bool ret;
2162 
2163 	if (fp->kprobe_override)
2164 		return false;
2165 
2166 	/* XDP programs inserted into maps are not guaranteed to run on
2167 	 * a particular netdev (and can run outside driver context entirely
2168 	 * in the case of devmap and cpumap). Until device checks
2169 	 * are implemented, prohibit adding dev-bound programs to program maps.
2170 	 */
2171 	if (bpf_prog_is_dev_bound(fp->aux))
2172 		return false;
2173 
2174 	spin_lock(&map->owner.lock);
2175 	if (!map->owner.type) {
2176 		/* There's no owner yet where we could check for
2177 		 * compatibility.
2178 		 */
2179 		map->owner.type  = prog_type;
2180 		map->owner.jited = fp->jited;
2181 		map->owner.xdp_has_frags = fp->aux->xdp_has_frags;
2182 		ret = true;
2183 	} else {
2184 		ret = map->owner.type  == prog_type &&
2185 		      map->owner.jited == fp->jited &&
2186 		      map->owner.xdp_has_frags == fp->aux->xdp_has_frags;
2187 	}
2188 	spin_unlock(&map->owner.lock);
2189 
2190 	return ret;
2191 }
2192 
2193 static int bpf_check_tail_call(const struct bpf_prog *fp)
2194 {
2195 	struct bpf_prog_aux *aux = fp->aux;
2196 	int i, ret = 0;
2197 
2198 	mutex_lock(&aux->used_maps_mutex);
2199 	for (i = 0; i < aux->used_map_cnt; i++) {
2200 		struct bpf_map *map = aux->used_maps[i];
2201 
2202 		if (!map_type_contains_progs(map))
2203 			continue;
2204 
2205 		if (!bpf_prog_map_compatible(map, fp)) {
2206 			ret = -EINVAL;
2207 			goto out;
2208 		}
2209 	}
2210 
2211 out:
2212 	mutex_unlock(&aux->used_maps_mutex);
2213 	return ret;
2214 }
2215 
2216 static void bpf_prog_select_func(struct bpf_prog *fp)
2217 {
2218 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
2219 	u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2220 
2221 	fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
2222 #else
2223 	fp->bpf_func = __bpf_prog_ret0_warn;
2224 #endif
2225 }
2226 
2227 /**
2228  *	bpf_prog_select_runtime - select exec runtime for BPF program
2229  *	@fp: bpf_prog populated with BPF program
2230  *	@err: pointer to error variable
2231  *
2232  * Try to JIT eBPF program, if JIT is not available, use interpreter.
2233  * The BPF program will be executed via bpf_prog_run() function.
2234  *
2235  * Return: the &fp argument along with &err set to 0 for success or
2236  * a negative errno code on failure
2237  */
2238 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2239 {
2240 	/* In case of BPF to BPF calls, verifier did all the prep
2241 	 * work with regards to JITing, etc.
2242 	 */
2243 	bool jit_needed = false;
2244 
2245 	if (fp->bpf_func)
2246 		goto finalize;
2247 
2248 	if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
2249 	    bpf_prog_has_kfunc_call(fp))
2250 		jit_needed = true;
2251 
2252 	bpf_prog_select_func(fp);
2253 
2254 	/* eBPF JITs can rewrite the program in case constant
2255 	 * blinding is active. However, in case of error during
2256 	 * blinding, bpf_int_jit_compile() must always return a
2257 	 * valid program, which in this case would simply not
2258 	 * be JITed, but falls back to the interpreter.
2259 	 */
2260 	if (!bpf_prog_is_offloaded(fp->aux)) {
2261 		*err = bpf_prog_alloc_jited_linfo(fp);
2262 		if (*err)
2263 			return fp;
2264 
2265 		fp = bpf_int_jit_compile(fp);
2266 		bpf_prog_jit_attempt_done(fp);
2267 		if (!fp->jited && jit_needed) {
2268 			*err = -ENOTSUPP;
2269 			return fp;
2270 		}
2271 	} else {
2272 		*err = bpf_prog_offload_compile(fp);
2273 		if (*err)
2274 			return fp;
2275 	}
2276 
2277 finalize:
2278 	bpf_prog_lock_ro(fp);
2279 
2280 	/* The tail call compatibility check can only be done at
2281 	 * this late stage as we need to determine, if we deal
2282 	 * with JITed or non JITed program concatenations and not
2283 	 * all eBPF JITs might immediately support all features.
2284 	 */
2285 	*err = bpf_check_tail_call(fp);
2286 
2287 	return fp;
2288 }
2289 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2290 
2291 static unsigned int __bpf_prog_ret1(const void *ctx,
2292 				    const struct bpf_insn *insn)
2293 {
2294 	return 1;
2295 }
2296 
2297 static struct bpf_prog_dummy {
2298 	struct bpf_prog prog;
2299 } dummy_bpf_prog = {
2300 	.prog = {
2301 		.bpf_func = __bpf_prog_ret1,
2302 	},
2303 };
2304 
2305 struct bpf_empty_prog_array bpf_empty_prog_array = {
2306 	.null_prog = NULL,
2307 };
2308 EXPORT_SYMBOL(bpf_empty_prog_array);
2309 
2310 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2311 {
2312 	if (prog_cnt)
2313 		return kzalloc(sizeof(struct bpf_prog_array) +
2314 			       sizeof(struct bpf_prog_array_item) *
2315 			       (prog_cnt + 1),
2316 			       flags);
2317 
2318 	return &bpf_empty_prog_array.hdr;
2319 }
2320 
2321 void bpf_prog_array_free(struct bpf_prog_array *progs)
2322 {
2323 	if (!progs || progs == &bpf_empty_prog_array.hdr)
2324 		return;
2325 	kfree_rcu(progs, rcu);
2326 }
2327 
2328 static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2329 {
2330 	struct bpf_prog_array *progs;
2331 
2332 	/* If RCU Tasks Trace grace period implies RCU grace period, there is
2333 	 * no need to call kfree_rcu(), just call kfree() directly.
2334 	 */
2335 	progs = container_of(rcu, struct bpf_prog_array, rcu);
2336 	if (rcu_trace_implies_rcu_gp())
2337 		kfree(progs);
2338 	else
2339 		kfree_rcu(progs, rcu);
2340 }
2341 
2342 void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2343 {
2344 	if (!progs || progs == &bpf_empty_prog_array.hdr)
2345 		return;
2346 	call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2347 }
2348 
2349 int bpf_prog_array_length(struct bpf_prog_array *array)
2350 {
2351 	struct bpf_prog_array_item *item;
2352 	u32 cnt = 0;
2353 
2354 	for (item = array->items; item->prog; item++)
2355 		if (item->prog != &dummy_bpf_prog.prog)
2356 			cnt++;
2357 	return cnt;
2358 }
2359 
2360 bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2361 {
2362 	struct bpf_prog_array_item *item;
2363 
2364 	for (item = array->items; item->prog; item++)
2365 		if (item->prog != &dummy_bpf_prog.prog)
2366 			return false;
2367 	return true;
2368 }
2369 
2370 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2371 				     u32 *prog_ids,
2372 				     u32 request_cnt)
2373 {
2374 	struct bpf_prog_array_item *item;
2375 	int i = 0;
2376 
2377 	for (item = array->items; item->prog; item++) {
2378 		if (item->prog == &dummy_bpf_prog.prog)
2379 			continue;
2380 		prog_ids[i] = item->prog->aux->id;
2381 		if (++i == request_cnt) {
2382 			item++;
2383 			break;
2384 		}
2385 	}
2386 
2387 	return !!(item->prog);
2388 }
2389 
2390 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2391 				__u32 __user *prog_ids, u32 cnt)
2392 {
2393 	unsigned long err = 0;
2394 	bool nospc;
2395 	u32 *ids;
2396 
2397 	/* users of this function are doing:
2398 	 * cnt = bpf_prog_array_length();
2399 	 * if (cnt > 0)
2400 	 *     bpf_prog_array_copy_to_user(..., cnt);
2401 	 * so below kcalloc doesn't need extra cnt > 0 check.
2402 	 */
2403 	ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2404 	if (!ids)
2405 		return -ENOMEM;
2406 	nospc = bpf_prog_array_copy_core(array, ids, cnt);
2407 	err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2408 	kfree(ids);
2409 	if (err)
2410 		return -EFAULT;
2411 	if (nospc)
2412 		return -ENOSPC;
2413 	return 0;
2414 }
2415 
2416 void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2417 				struct bpf_prog *old_prog)
2418 {
2419 	struct bpf_prog_array_item *item;
2420 
2421 	for (item = array->items; item->prog; item++)
2422 		if (item->prog == old_prog) {
2423 			WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2424 			break;
2425 		}
2426 }
2427 
2428 /**
2429  * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2430  *                                   index into the program array with
2431  *                                   a dummy no-op program.
2432  * @array: a bpf_prog_array
2433  * @index: the index of the program to replace
2434  *
2435  * Skips over dummy programs, by not counting them, when calculating
2436  * the position of the program to replace.
2437  *
2438  * Return:
2439  * * 0		- Success
2440  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2441  * * -ENOENT	- Index out of range
2442  */
2443 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2444 {
2445 	return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2446 }
2447 
2448 /**
2449  * bpf_prog_array_update_at() - Updates the program at the given index
2450  *                              into the program array.
2451  * @array: a bpf_prog_array
2452  * @index: the index of the program to update
2453  * @prog: the program to insert into the array
2454  *
2455  * Skips over dummy programs, by not counting them, when calculating
2456  * the position of the program to update.
2457  *
2458  * Return:
2459  * * 0		- Success
2460  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2461  * * -ENOENT	- Index out of range
2462  */
2463 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2464 			     struct bpf_prog *prog)
2465 {
2466 	struct bpf_prog_array_item *item;
2467 
2468 	if (unlikely(index < 0))
2469 		return -EINVAL;
2470 
2471 	for (item = array->items; item->prog; item++) {
2472 		if (item->prog == &dummy_bpf_prog.prog)
2473 			continue;
2474 		if (!index) {
2475 			WRITE_ONCE(item->prog, prog);
2476 			return 0;
2477 		}
2478 		index--;
2479 	}
2480 	return -ENOENT;
2481 }
2482 
2483 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2484 			struct bpf_prog *exclude_prog,
2485 			struct bpf_prog *include_prog,
2486 			u64 bpf_cookie,
2487 			struct bpf_prog_array **new_array)
2488 {
2489 	int new_prog_cnt, carry_prog_cnt = 0;
2490 	struct bpf_prog_array_item *existing, *new;
2491 	struct bpf_prog_array *array;
2492 	bool found_exclude = false;
2493 
2494 	/* Figure out how many existing progs we need to carry over to
2495 	 * the new array.
2496 	 */
2497 	if (old_array) {
2498 		existing = old_array->items;
2499 		for (; existing->prog; existing++) {
2500 			if (existing->prog == exclude_prog) {
2501 				found_exclude = true;
2502 				continue;
2503 			}
2504 			if (existing->prog != &dummy_bpf_prog.prog)
2505 				carry_prog_cnt++;
2506 			if (existing->prog == include_prog)
2507 				return -EEXIST;
2508 		}
2509 	}
2510 
2511 	if (exclude_prog && !found_exclude)
2512 		return -ENOENT;
2513 
2514 	/* How many progs (not NULL) will be in the new array? */
2515 	new_prog_cnt = carry_prog_cnt;
2516 	if (include_prog)
2517 		new_prog_cnt += 1;
2518 
2519 	/* Do we have any prog (not NULL) in the new array? */
2520 	if (!new_prog_cnt) {
2521 		*new_array = NULL;
2522 		return 0;
2523 	}
2524 
2525 	/* +1 as the end of prog_array is marked with NULL */
2526 	array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2527 	if (!array)
2528 		return -ENOMEM;
2529 	new = array->items;
2530 
2531 	/* Fill in the new prog array */
2532 	if (carry_prog_cnt) {
2533 		existing = old_array->items;
2534 		for (; existing->prog; existing++) {
2535 			if (existing->prog == exclude_prog ||
2536 			    existing->prog == &dummy_bpf_prog.prog)
2537 				continue;
2538 
2539 			new->prog = existing->prog;
2540 			new->bpf_cookie = existing->bpf_cookie;
2541 			new++;
2542 		}
2543 	}
2544 	if (include_prog) {
2545 		new->prog = include_prog;
2546 		new->bpf_cookie = bpf_cookie;
2547 		new++;
2548 	}
2549 	new->prog = NULL;
2550 	*new_array = array;
2551 	return 0;
2552 }
2553 
2554 int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2555 			     u32 *prog_ids, u32 request_cnt,
2556 			     u32 *prog_cnt)
2557 {
2558 	u32 cnt = 0;
2559 
2560 	if (array)
2561 		cnt = bpf_prog_array_length(array);
2562 
2563 	*prog_cnt = cnt;
2564 
2565 	/* return early if user requested only program count or nothing to copy */
2566 	if (!request_cnt || !cnt)
2567 		return 0;
2568 
2569 	/* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2570 	return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2571 								     : 0;
2572 }
2573 
2574 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2575 			  struct bpf_map **used_maps, u32 len)
2576 {
2577 	struct bpf_map *map;
2578 	u32 i;
2579 
2580 	for (i = 0; i < len; i++) {
2581 		map = used_maps[i];
2582 		if (map->ops->map_poke_untrack)
2583 			map->ops->map_poke_untrack(map, aux);
2584 		bpf_map_put(map);
2585 	}
2586 }
2587 
2588 static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2589 {
2590 	__bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2591 	kfree(aux->used_maps);
2592 }
2593 
2594 void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
2595 			  struct btf_mod_pair *used_btfs, u32 len)
2596 {
2597 #ifdef CONFIG_BPF_SYSCALL
2598 	struct btf_mod_pair *btf_mod;
2599 	u32 i;
2600 
2601 	for (i = 0; i < len; i++) {
2602 		btf_mod = &used_btfs[i];
2603 		if (btf_mod->module)
2604 			module_put(btf_mod->module);
2605 		btf_put(btf_mod->btf);
2606 	}
2607 #endif
2608 }
2609 
2610 static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2611 {
2612 	__bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt);
2613 	kfree(aux->used_btfs);
2614 }
2615 
2616 static void bpf_prog_free_deferred(struct work_struct *work)
2617 {
2618 	struct bpf_prog_aux *aux;
2619 	int i;
2620 
2621 	aux = container_of(work, struct bpf_prog_aux, work);
2622 #ifdef CONFIG_BPF_SYSCALL
2623 	bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
2624 #endif
2625 #ifdef CONFIG_CGROUP_BPF
2626 	if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
2627 		bpf_cgroup_atype_put(aux->cgroup_atype);
2628 #endif
2629 	bpf_free_used_maps(aux);
2630 	bpf_free_used_btfs(aux);
2631 	if (bpf_prog_is_dev_bound(aux))
2632 		bpf_prog_dev_bound_destroy(aux->prog);
2633 #ifdef CONFIG_PERF_EVENTS
2634 	if (aux->prog->has_callchain_buf)
2635 		put_callchain_buffers();
2636 #endif
2637 	if (aux->dst_trampoline)
2638 		bpf_trampoline_put(aux->dst_trampoline);
2639 	for (i = 0; i < aux->func_cnt; i++) {
2640 		/* We can just unlink the subprog poke descriptor table as
2641 		 * it was originally linked to the main program and is also
2642 		 * released along with it.
2643 		 */
2644 		aux->func[i]->aux->poke_tab = NULL;
2645 		bpf_jit_free(aux->func[i]);
2646 	}
2647 	if (aux->func_cnt) {
2648 		kfree(aux->func);
2649 		bpf_prog_unlock_free(aux->prog);
2650 	} else {
2651 		bpf_jit_free(aux->prog);
2652 	}
2653 }
2654 
2655 void bpf_prog_free(struct bpf_prog *fp)
2656 {
2657 	struct bpf_prog_aux *aux = fp->aux;
2658 
2659 	if (aux->dst_prog)
2660 		bpf_prog_put(aux->dst_prog);
2661 	INIT_WORK(&aux->work, bpf_prog_free_deferred);
2662 	schedule_work(&aux->work);
2663 }
2664 EXPORT_SYMBOL_GPL(bpf_prog_free);
2665 
2666 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
2667 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2668 
2669 void bpf_user_rnd_init_once(void)
2670 {
2671 	prandom_init_once(&bpf_user_rnd_state);
2672 }
2673 
2674 BPF_CALL_0(bpf_user_rnd_u32)
2675 {
2676 	/* Should someone ever have the rather unwise idea to use some
2677 	 * of the registers passed into this function, then note that
2678 	 * this function is called from native eBPF and classic-to-eBPF
2679 	 * transformations. Register assignments from both sides are
2680 	 * different, f.e. classic always sets fn(ctx, A, X) here.
2681 	 */
2682 	struct rnd_state *state;
2683 	u32 res;
2684 
2685 	state = &get_cpu_var(bpf_user_rnd_state);
2686 	res = prandom_u32_state(state);
2687 	put_cpu_var(bpf_user_rnd_state);
2688 
2689 	return res;
2690 }
2691 
2692 BPF_CALL_0(bpf_get_raw_cpu_id)
2693 {
2694 	return raw_smp_processor_id();
2695 }
2696 
2697 /* Weak definitions of helper functions in case we don't have bpf syscall. */
2698 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2699 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2700 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2701 const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2702 const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2703 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2704 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
2705 const struct bpf_func_proto bpf_spin_lock_proto __weak;
2706 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2707 const struct bpf_func_proto bpf_jiffies64_proto __weak;
2708 
2709 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2710 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2711 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2712 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2713 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2714 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2715 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
2716 
2717 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2718 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2719 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2720 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2721 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2722 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2723 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2724 const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2725 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2726 const struct bpf_func_proto bpf_set_retval_proto __weak;
2727 const struct bpf_func_proto bpf_get_retval_proto __weak;
2728 
2729 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2730 {
2731 	return NULL;
2732 }
2733 
2734 const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
2735 {
2736 	return NULL;
2737 }
2738 
2739 u64 __weak
2740 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2741 		 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2742 {
2743 	return -ENOTSUPP;
2744 }
2745 EXPORT_SYMBOL_GPL(bpf_event_output);
2746 
2747 /* Always built-in helper functions. */
2748 const struct bpf_func_proto bpf_tail_call_proto = {
2749 	.func		= NULL,
2750 	.gpl_only	= false,
2751 	.ret_type	= RET_VOID,
2752 	.arg1_type	= ARG_PTR_TO_CTX,
2753 	.arg2_type	= ARG_CONST_MAP_PTR,
2754 	.arg3_type	= ARG_ANYTHING,
2755 };
2756 
2757 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2758  * It is encouraged to implement bpf_int_jit_compile() instead, so that
2759  * eBPF and implicitly also cBPF can get JITed!
2760  */
2761 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2762 {
2763 	return prog;
2764 }
2765 
2766 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
2767  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2768  */
2769 void __weak bpf_jit_compile(struct bpf_prog *prog)
2770 {
2771 }
2772 
2773 bool __weak bpf_helper_changes_pkt_data(void *func)
2774 {
2775 	return false;
2776 }
2777 
2778 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2779  * analysis code and wants explicit zero extension inserted by verifier.
2780  * Otherwise, return FALSE.
2781  *
2782  * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2783  * you don't override this. JITs that don't want these extra insns can detect
2784  * them using insn_is_zext.
2785  */
2786 bool __weak bpf_jit_needs_zext(void)
2787 {
2788 	return false;
2789 }
2790 
2791 /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
2792 bool __weak bpf_jit_supports_subprog_tailcalls(void)
2793 {
2794 	return false;
2795 }
2796 
2797 bool __weak bpf_jit_supports_kfunc_call(void)
2798 {
2799 	return false;
2800 }
2801 
2802 bool __weak bpf_jit_supports_far_kfunc_call(void)
2803 {
2804 	return false;
2805 }
2806 
2807 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
2808  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
2809  */
2810 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
2811 			 int len)
2812 {
2813 	return -EFAULT;
2814 }
2815 
2816 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
2817 			      void *addr1, void *addr2)
2818 {
2819 	return -ENOTSUPP;
2820 }
2821 
2822 void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
2823 {
2824 	return ERR_PTR(-ENOTSUPP);
2825 }
2826 
2827 int __weak bpf_arch_text_invalidate(void *dst, size_t len)
2828 {
2829 	return -ENOTSUPP;
2830 }
2831 
2832 #ifdef CONFIG_BPF_SYSCALL
2833 static int __init bpf_global_ma_init(void)
2834 {
2835 	int ret;
2836 
2837 	ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
2838 	bpf_global_ma_set = !ret;
2839 	return ret;
2840 }
2841 late_initcall(bpf_global_ma_init);
2842 #endif
2843 
2844 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
2845 EXPORT_SYMBOL(bpf_stats_enabled_key);
2846 
2847 /* All definitions of tracepoints related to BPF. */
2848 #define CREATE_TRACE_POINTS
2849 #include <linux/bpf_trace.h>
2850 
2851 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
2852 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);
2853