xref: /linux/kernel/bpf/core.c (revision 524581d1216411a807d34181cb880d991fcb4b96)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Linux Socket Filter - Kernel level socket filtering
4  *
5  * Based on the design of the Berkeley Packet Filter. The new
6  * internal format has been designed by PLUMgrid:
7  *
8  *	Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
9  *
10  * Authors:
11  *
12  *	Jay Schulist <jschlst@samba.org>
13  *	Alexei Starovoitov <ast@plumgrid.com>
14  *	Daniel Borkmann <dborkman@redhat.com>
15  *
16  * Andi Kleen - Fix a few bad bugs and races.
17  * Kris Katterjohn - Added many additional checks in bpf_check_classic()
18  */
19 
20 #include <uapi/linux/btf.h>
21 #include <linux/filter.h>
22 #include <linux/skbuff.h>
23 #include <linux/vmalloc.h>
24 #include <linux/random.h>
25 #include <linux/moduleloader.h>
26 #include <linux/bpf.h>
27 #include <linux/btf.h>
28 #include <linux/objtool.h>
29 #include <linux/rbtree_latch.h>
30 #include <linux/kallsyms.h>
31 #include <linux/rcupdate.h>
32 #include <linux/perf_event.h>
33 #include <linux/extable.h>
34 #include <linux/log2.h>
35 #include <linux/bpf_verifier.h>
36 #include <linux/nodemask.h>
37 #include <linux/bpf_mem_alloc.h>
38 #include <linux/memcontrol.h>
39 
40 #include <asm/barrier.h>
41 #include <asm/unaligned.h>
42 
43 /* Registers */
44 #define BPF_R0	regs[BPF_REG_0]
45 #define BPF_R1	regs[BPF_REG_1]
46 #define BPF_R2	regs[BPF_REG_2]
47 #define BPF_R3	regs[BPF_REG_3]
48 #define BPF_R4	regs[BPF_REG_4]
49 #define BPF_R5	regs[BPF_REG_5]
50 #define BPF_R6	regs[BPF_REG_6]
51 #define BPF_R7	regs[BPF_REG_7]
52 #define BPF_R8	regs[BPF_REG_8]
53 #define BPF_R9	regs[BPF_REG_9]
54 #define BPF_R10	regs[BPF_REG_10]
55 
56 /* Named registers */
57 #define DST	regs[insn->dst_reg]
58 #define SRC	regs[insn->src_reg]
59 #define FP	regs[BPF_REG_FP]
60 #define AX	regs[BPF_REG_AX]
61 #define ARG1	regs[BPF_REG_ARG1]
62 #define CTX	regs[BPF_REG_CTX]
63 #define IMM	insn->imm
64 
65 struct bpf_mem_alloc bpf_global_ma;
66 bool bpf_global_ma_set;
67 
68 /* No hurry in this branch
69  *
70  * Exported for the bpf jit load helper.
71  */
72 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
73 {
74 	u8 *ptr = NULL;
75 
76 	if (k >= SKF_NET_OFF) {
77 		ptr = skb_network_header(skb) + k - SKF_NET_OFF;
78 	} else if (k >= SKF_LL_OFF) {
79 		if (unlikely(!skb_mac_header_was_set(skb)))
80 			return NULL;
81 		ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
82 	}
83 	if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
84 		return ptr;
85 
86 	return NULL;
87 }
88 
89 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
90 {
91 	gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
92 	struct bpf_prog_aux *aux;
93 	struct bpf_prog *fp;
94 
95 	size = round_up(size, PAGE_SIZE);
96 	fp = __vmalloc(size, gfp_flags);
97 	if (fp == NULL)
98 		return NULL;
99 
100 	aux = kzalloc(sizeof(*aux), bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
101 	if (aux == NULL) {
102 		vfree(fp);
103 		return NULL;
104 	}
105 	fp->active = alloc_percpu_gfp(int, bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
106 	if (!fp->active) {
107 		vfree(fp);
108 		kfree(aux);
109 		return NULL;
110 	}
111 
112 	fp->pages = size / PAGE_SIZE;
113 	fp->aux = aux;
114 	fp->aux->prog = fp;
115 	fp->jit_requested = ebpf_jit_enabled();
116 	fp->blinding_requested = bpf_jit_blinding_enabled(fp);
117 #ifdef CONFIG_CGROUP_BPF
118 	aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID;
119 #endif
120 
121 	INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
122 	mutex_init(&fp->aux->used_maps_mutex);
123 	mutex_init(&fp->aux->dst_mutex);
124 
125 	return fp;
126 }
127 
128 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
129 {
130 	gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
131 	struct bpf_prog *prog;
132 	int cpu;
133 
134 	prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
135 	if (!prog)
136 		return NULL;
137 
138 	prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
139 	if (!prog->stats) {
140 		free_percpu(prog->active);
141 		kfree(prog->aux);
142 		vfree(prog);
143 		return NULL;
144 	}
145 
146 	for_each_possible_cpu(cpu) {
147 		struct bpf_prog_stats *pstats;
148 
149 		pstats = per_cpu_ptr(prog->stats, cpu);
150 		u64_stats_init(&pstats->syncp);
151 	}
152 	return prog;
153 }
154 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
155 
156 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
157 {
158 	if (!prog->aux->nr_linfo || !prog->jit_requested)
159 		return 0;
160 
161 	prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
162 					  sizeof(*prog->aux->jited_linfo),
163 					  bpf_memcg_flags(GFP_KERNEL | __GFP_NOWARN));
164 	if (!prog->aux->jited_linfo)
165 		return -ENOMEM;
166 
167 	return 0;
168 }
169 
170 void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
171 {
172 	if (prog->aux->jited_linfo &&
173 	    (!prog->jited || !prog->aux->jited_linfo[0])) {
174 		kvfree(prog->aux->jited_linfo);
175 		prog->aux->jited_linfo = NULL;
176 	}
177 
178 	kfree(prog->aux->kfunc_tab);
179 	prog->aux->kfunc_tab = NULL;
180 }
181 
182 /* The jit engine is responsible to provide an array
183  * for insn_off to the jited_off mapping (insn_to_jit_off).
184  *
185  * The idx to this array is the insn_off.  Hence, the insn_off
186  * here is relative to the prog itself instead of the main prog.
187  * This array has one entry for each xlated bpf insn.
188  *
189  * jited_off is the byte off to the end of the jited insn.
190  *
191  * Hence, with
192  * insn_start:
193  *      The first bpf insn off of the prog.  The insn off
194  *      here is relative to the main prog.
195  *      e.g. if prog is a subprog, insn_start > 0
196  * linfo_idx:
197  *      The prog's idx to prog->aux->linfo and jited_linfo
198  *
199  * jited_linfo[linfo_idx] = prog->bpf_func
200  *
201  * For i > linfo_idx,
202  *
203  * jited_linfo[i] = prog->bpf_func +
204  *	insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
205  */
206 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
207 			       const u32 *insn_to_jit_off)
208 {
209 	u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
210 	const struct bpf_line_info *linfo;
211 	void **jited_linfo;
212 
213 	if (!prog->aux->jited_linfo)
214 		/* Userspace did not provide linfo */
215 		return;
216 
217 	linfo_idx = prog->aux->linfo_idx;
218 	linfo = &prog->aux->linfo[linfo_idx];
219 	insn_start = linfo[0].insn_off;
220 	insn_end = insn_start + prog->len;
221 
222 	jited_linfo = &prog->aux->jited_linfo[linfo_idx];
223 	jited_linfo[0] = prog->bpf_func;
224 
225 	nr_linfo = prog->aux->nr_linfo - linfo_idx;
226 
227 	for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
228 		/* The verifier ensures that linfo[i].insn_off is
229 		 * strictly increasing
230 		 */
231 		jited_linfo[i] = prog->bpf_func +
232 			insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
233 }
234 
235 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
236 				  gfp_t gfp_extra_flags)
237 {
238 	gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
239 	struct bpf_prog *fp;
240 	u32 pages;
241 
242 	size = round_up(size, PAGE_SIZE);
243 	pages = size / PAGE_SIZE;
244 	if (pages <= fp_old->pages)
245 		return fp_old;
246 
247 	fp = __vmalloc(size, gfp_flags);
248 	if (fp) {
249 		memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
250 		fp->pages = pages;
251 		fp->aux->prog = fp;
252 
253 		/* We keep fp->aux from fp_old around in the new
254 		 * reallocated structure.
255 		 */
256 		fp_old->aux = NULL;
257 		fp_old->stats = NULL;
258 		fp_old->active = NULL;
259 		__bpf_prog_free(fp_old);
260 	}
261 
262 	return fp;
263 }
264 
265 void __bpf_prog_free(struct bpf_prog *fp)
266 {
267 	if (fp->aux) {
268 		mutex_destroy(&fp->aux->used_maps_mutex);
269 		mutex_destroy(&fp->aux->dst_mutex);
270 		kfree(fp->aux->poke_tab);
271 		kfree(fp->aux);
272 	}
273 	free_percpu(fp->stats);
274 	free_percpu(fp->active);
275 	vfree(fp);
276 }
277 
278 int bpf_prog_calc_tag(struct bpf_prog *fp)
279 {
280 	const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
281 	u32 raw_size = bpf_prog_tag_scratch_size(fp);
282 	u32 digest[SHA1_DIGEST_WORDS];
283 	u32 ws[SHA1_WORKSPACE_WORDS];
284 	u32 i, bsize, psize, blocks;
285 	struct bpf_insn *dst;
286 	bool was_ld_map;
287 	u8 *raw, *todo;
288 	__be32 *result;
289 	__be64 *bits;
290 
291 	raw = vmalloc(raw_size);
292 	if (!raw)
293 		return -ENOMEM;
294 
295 	sha1_init(digest);
296 	memset(ws, 0, sizeof(ws));
297 
298 	/* We need to take out the map fd for the digest calculation
299 	 * since they are unstable from user space side.
300 	 */
301 	dst = (void *)raw;
302 	for (i = 0, was_ld_map = false; i < fp->len; i++) {
303 		dst[i] = fp->insnsi[i];
304 		if (!was_ld_map &&
305 		    dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
306 		    (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
307 		     dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
308 			was_ld_map = true;
309 			dst[i].imm = 0;
310 		} else if (was_ld_map &&
311 			   dst[i].code == 0 &&
312 			   dst[i].dst_reg == 0 &&
313 			   dst[i].src_reg == 0 &&
314 			   dst[i].off == 0) {
315 			was_ld_map = false;
316 			dst[i].imm = 0;
317 		} else {
318 			was_ld_map = false;
319 		}
320 	}
321 
322 	psize = bpf_prog_insn_size(fp);
323 	memset(&raw[psize], 0, raw_size - psize);
324 	raw[psize++] = 0x80;
325 
326 	bsize  = round_up(psize, SHA1_BLOCK_SIZE);
327 	blocks = bsize / SHA1_BLOCK_SIZE;
328 	todo   = raw;
329 	if (bsize - psize >= sizeof(__be64)) {
330 		bits = (__be64 *)(todo + bsize - sizeof(__be64));
331 	} else {
332 		bits = (__be64 *)(todo + bsize + bits_offset);
333 		blocks++;
334 	}
335 	*bits = cpu_to_be64((psize - 1) << 3);
336 
337 	while (blocks--) {
338 		sha1_transform(digest, todo, ws);
339 		todo += SHA1_BLOCK_SIZE;
340 	}
341 
342 	result = (__force __be32 *)digest;
343 	for (i = 0; i < SHA1_DIGEST_WORDS; i++)
344 		result[i] = cpu_to_be32(digest[i]);
345 	memcpy(fp->tag, result, sizeof(fp->tag));
346 
347 	vfree(raw);
348 	return 0;
349 }
350 
351 static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
352 				s32 end_new, s32 curr, const bool probe_pass)
353 {
354 	const s64 imm_min = S32_MIN, imm_max = S32_MAX;
355 	s32 delta = end_new - end_old;
356 	s64 imm = insn->imm;
357 
358 	if (curr < pos && curr + imm + 1 >= end_old)
359 		imm += delta;
360 	else if (curr >= end_new && curr + imm + 1 < end_new)
361 		imm -= delta;
362 	if (imm < imm_min || imm > imm_max)
363 		return -ERANGE;
364 	if (!probe_pass)
365 		insn->imm = imm;
366 	return 0;
367 }
368 
369 static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
370 				s32 end_new, s32 curr, const bool probe_pass)
371 {
372 	const s32 off_min = S16_MIN, off_max = S16_MAX;
373 	s32 delta = end_new - end_old;
374 	s32 off = insn->off;
375 
376 	if (curr < pos && curr + off + 1 >= end_old)
377 		off += delta;
378 	else if (curr >= end_new && curr + off + 1 < end_new)
379 		off -= delta;
380 	if (off < off_min || off > off_max)
381 		return -ERANGE;
382 	if (!probe_pass)
383 		insn->off = off;
384 	return 0;
385 }
386 
387 static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
388 			    s32 end_new, const bool probe_pass)
389 {
390 	u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
391 	struct bpf_insn *insn = prog->insnsi;
392 	int ret = 0;
393 
394 	for (i = 0; i < insn_cnt; i++, insn++) {
395 		u8 code;
396 
397 		/* In the probing pass we still operate on the original,
398 		 * unpatched image in order to check overflows before we
399 		 * do any other adjustments. Therefore skip the patchlet.
400 		 */
401 		if (probe_pass && i == pos) {
402 			i = end_new;
403 			insn = prog->insnsi + end_old;
404 		}
405 		if (bpf_pseudo_func(insn)) {
406 			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
407 						   end_new, i, probe_pass);
408 			if (ret)
409 				return ret;
410 			continue;
411 		}
412 		code = insn->code;
413 		if ((BPF_CLASS(code) != BPF_JMP &&
414 		     BPF_CLASS(code) != BPF_JMP32) ||
415 		    BPF_OP(code) == BPF_EXIT)
416 			continue;
417 		/* Adjust offset of jmps if we cross patch boundaries. */
418 		if (BPF_OP(code) == BPF_CALL) {
419 			if (insn->src_reg != BPF_PSEUDO_CALL)
420 				continue;
421 			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
422 						   end_new, i, probe_pass);
423 		} else {
424 			ret = bpf_adj_delta_to_off(insn, pos, end_old,
425 						   end_new, i, probe_pass);
426 		}
427 		if (ret)
428 			break;
429 	}
430 
431 	return ret;
432 }
433 
434 static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
435 {
436 	struct bpf_line_info *linfo;
437 	u32 i, nr_linfo;
438 
439 	nr_linfo = prog->aux->nr_linfo;
440 	if (!nr_linfo || !delta)
441 		return;
442 
443 	linfo = prog->aux->linfo;
444 
445 	for (i = 0; i < nr_linfo; i++)
446 		if (off < linfo[i].insn_off)
447 			break;
448 
449 	/* Push all off < linfo[i].insn_off by delta */
450 	for (; i < nr_linfo; i++)
451 		linfo[i].insn_off += delta;
452 }
453 
454 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
455 				       const struct bpf_insn *patch, u32 len)
456 {
457 	u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
458 	const u32 cnt_max = S16_MAX;
459 	struct bpf_prog *prog_adj;
460 	int err;
461 
462 	/* Since our patchlet doesn't expand the image, we're done. */
463 	if (insn_delta == 0) {
464 		memcpy(prog->insnsi + off, patch, sizeof(*patch));
465 		return prog;
466 	}
467 
468 	insn_adj_cnt = prog->len + insn_delta;
469 
470 	/* Reject anything that would potentially let the insn->off
471 	 * target overflow when we have excessive program expansions.
472 	 * We need to probe here before we do any reallocation where
473 	 * we afterwards may not fail anymore.
474 	 */
475 	if (insn_adj_cnt > cnt_max &&
476 	    (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
477 		return ERR_PTR(err);
478 
479 	/* Several new instructions need to be inserted. Make room
480 	 * for them. Likely, there's no need for a new allocation as
481 	 * last page could have large enough tailroom.
482 	 */
483 	prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
484 				    GFP_USER);
485 	if (!prog_adj)
486 		return ERR_PTR(-ENOMEM);
487 
488 	prog_adj->len = insn_adj_cnt;
489 
490 	/* Patching happens in 3 steps:
491 	 *
492 	 * 1) Move over tail of insnsi from next instruction onwards,
493 	 *    so we can patch the single target insn with one or more
494 	 *    new ones (patching is always from 1 to n insns, n > 0).
495 	 * 2) Inject new instructions at the target location.
496 	 * 3) Adjust branch offsets if necessary.
497 	 */
498 	insn_rest = insn_adj_cnt - off - len;
499 
500 	memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
501 		sizeof(*patch) * insn_rest);
502 	memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
503 
504 	/* We are guaranteed to not fail at this point, otherwise
505 	 * the ship has sailed to reverse to the original state. An
506 	 * overflow cannot happen at this point.
507 	 */
508 	BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
509 
510 	bpf_adj_linfo(prog_adj, off, insn_delta);
511 
512 	return prog_adj;
513 }
514 
515 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
516 {
517 	/* Branch offsets can't overflow when program is shrinking, no need
518 	 * to call bpf_adj_branches(..., true) here
519 	 */
520 	memmove(prog->insnsi + off, prog->insnsi + off + cnt,
521 		sizeof(struct bpf_insn) * (prog->len - off - cnt));
522 	prog->len -= cnt;
523 
524 	return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
525 }
526 
527 static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
528 {
529 	int i;
530 
531 	for (i = 0; i < fp->aux->func_cnt; i++)
532 		bpf_prog_kallsyms_del(fp->aux->func[i]);
533 }
534 
535 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
536 {
537 	bpf_prog_kallsyms_del_subprogs(fp);
538 	bpf_prog_kallsyms_del(fp);
539 }
540 
541 #ifdef CONFIG_BPF_JIT
542 /* All BPF JIT sysctl knobs here. */
543 int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
544 int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
545 int bpf_jit_harden   __read_mostly;
546 long bpf_jit_limit   __read_mostly;
547 long bpf_jit_limit_max __read_mostly;
548 
549 static void
550 bpf_prog_ksym_set_addr(struct bpf_prog *prog)
551 {
552 	WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
553 
554 	prog->aux->ksym.start = (unsigned long) prog->bpf_func;
555 	prog->aux->ksym.end   = prog->aux->ksym.start + prog->jited_len;
556 }
557 
558 static void
559 bpf_prog_ksym_set_name(struct bpf_prog *prog)
560 {
561 	char *sym = prog->aux->ksym.name;
562 	const char *end = sym + KSYM_NAME_LEN;
563 	const struct btf_type *type;
564 	const char *func_name;
565 
566 	BUILD_BUG_ON(sizeof("bpf_prog_") +
567 		     sizeof(prog->tag) * 2 +
568 		     /* name has been null terminated.
569 		      * We should need +1 for the '_' preceding
570 		      * the name.  However, the null character
571 		      * is double counted between the name and the
572 		      * sizeof("bpf_prog_") above, so we omit
573 		      * the +1 here.
574 		      */
575 		     sizeof(prog->aux->name) > KSYM_NAME_LEN);
576 
577 	sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
578 	sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
579 
580 	/* prog->aux->name will be ignored if full btf name is available */
581 	if (prog->aux->func_info_cnt) {
582 		type = btf_type_by_id(prog->aux->btf,
583 				      prog->aux->func_info[prog->aux->func_idx].type_id);
584 		func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
585 		snprintf(sym, (size_t)(end - sym), "_%s", func_name);
586 		return;
587 	}
588 
589 	if (prog->aux->name[0])
590 		snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
591 	else
592 		*sym = 0;
593 }
594 
595 static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
596 {
597 	return container_of(n, struct bpf_ksym, tnode)->start;
598 }
599 
600 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
601 					  struct latch_tree_node *b)
602 {
603 	return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
604 }
605 
606 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
607 {
608 	unsigned long val = (unsigned long)key;
609 	const struct bpf_ksym *ksym;
610 
611 	ksym = container_of(n, struct bpf_ksym, tnode);
612 
613 	if (val < ksym->start)
614 		return -1;
615 	if (val >= ksym->end)
616 		return  1;
617 
618 	return 0;
619 }
620 
621 static const struct latch_tree_ops bpf_tree_ops = {
622 	.less	= bpf_tree_less,
623 	.comp	= bpf_tree_comp,
624 };
625 
626 static DEFINE_SPINLOCK(bpf_lock);
627 static LIST_HEAD(bpf_kallsyms);
628 static struct latch_tree_root bpf_tree __cacheline_aligned;
629 
630 void bpf_ksym_add(struct bpf_ksym *ksym)
631 {
632 	spin_lock_bh(&bpf_lock);
633 	WARN_ON_ONCE(!list_empty(&ksym->lnode));
634 	list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
635 	latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
636 	spin_unlock_bh(&bpf_lock);
637 }
638 
639 static void __bpf_ksym_del(struct bpf_ksym *ksym)
640 {
641 	if (list_empty(&ksym->lnode))
642 		return;
643 
644 	latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
645 	list_del_rcu(&ksym->lnode);
646 }
647 
648 void bpf_ksym_del(struct bpf_ksym *ksym)
649 {
650 	spin_lock_bh(&bpf_lock);
651 	__bpf_ksym_del(ksym);
652 	spin_unlock_bh(&bpf_lock);
653 }
654 
655 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
656 {
657 	return fp->jited && !bpf_prog_was_classic(fp);
658 }
659 
660 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
661 {
662 	if (!bpf_prog_kallsyms_candidate(fp) ||
663 	    !bpf_capable())
664 		return;
665 
666 	bpf_prog_ksym_set_addr(fp);
667 	bpf_prog_ksym_set_name(fp);
668 	fp->aux->ksym.prog = true;
669 
670 	bpf_ksym_add(&fp->aux->ksym);
671 }
672 
673 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
674 {
675 	if (!bpf_prog_kallsyms_candidate(fp))
676 		return;
677 
678 	bpf_ksym_del(&fp->aux->ksym);
679 }
680 
681 static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
682 {
683 	struct latch_tree_node *n;
684 
685 	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
686 	return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
687 }
688 
689 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
690 				 unsigned long *off, char *sym)
691 {
692 	struct bpf_ksym *ksym;
693 	char *ret = NULL;
694 
695 	rcu_read_lock();
696 	ksym = bpf_ksym_find(addr);
697 	if (ksym) {
698 		unsigned long symbol_start = ksym->start;
699 		unsigned long symbol_end = ksym->end;
700 
701 		strncpy(sym, ksym->name, KSYM_NAME_LEN);
702 
703 		ret = sym;
704 		if (size)
705 			*size = symbol_end - symbol_start;
706 		if (off)
707 			*off  = addr - symbol_start;
708 	}
709 	rcu_read_unlock();
710 
711 	return ret;
712 }
713 
714 bool is_bpf_text_address(unsigned long addr)
715 {
716 	bool ret;
717 
718 	rcu_read_lock();
719 	ret = bpf_ksym_find(addr) != NULL;
720 	rcu_read_unlock();
721 
722 	return ret;
723 }
724 
725 static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
726 {
727 	struct bpf_ksym *ksym = bpf_ksym_find(addr);
728 
729 	return ksym && ksym->prog ?
730 	       container_of(ksym, struct bpf_prog_aux, ksym)->prog :
731 	       NULL;
732 }
733 
734 const struct exception_table_entry *search_bpf_extables(unsigned long addr)
735 {
736 	const struct exception_table_entry *e = NULL;
737 	struct bpf_prog *prog;
738 
739 	rcu_read_lock();
740 	prog = bpf_prog_ksym_find(addr);
741 	if (!prog)
742 		goto out;
743 	if (!prog->aux->num_exentries)
744 		goto out;
745 
746 	e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
747 out:
748 	rcu_read_unlock();
749 	return e;
750 }
751 
752 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
753 		    char *sym)
754 {
755 	struct bpf_ksym *ksym;
756 	unsigned int it = 0;
757 	int ret = -ERANGE;
758 
759 	if (!bpf_jit_kallsyms_enabled())
760 		return ret;
761 
762 	rcu_read_lock();
763 	list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
764 		if (it++ != symnum)
765 			continue;
766 
767 		strncpy(sym, ksym->name, KSYM_NAME_LEN);
768 
769 		*value = ksym->start;
770 		*type  = BPF_SYM_ELF_TYPE;
771 
772 		ret = 0;
773 		break;
774 	}
775 	rcu_read_unlock();
776 
777 	return ret;
778 }
779 
780 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
781 				struct bpf_jit_poke_descriptor *poke)
782 {
783 	struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
784 	static const u32 poke_tab_max = 1024;
785 	u32 slot = prog->aux->size_poke_tab;
786 	u32 size = slot + 1;
787 
788 	if (size > poke_tab_max)
789 		return -ENOSPC;
790 	if (poke->tailcall_target || poke->tailcall_target_stable ||
791 	    poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
792 		return -EINVAL;
793 
794 	switch (poke->reason) {
795 	case BPF_POKE_REASON_TAIL_CALL:
796 		if (!poke->tail_call.map)
797 			return -EINVAL;
798 		break;
799 	default:
800 		return -EINVAL;
801 	}
802 
803 	tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
804 	if (!tab)
805 		return -ENOMEM;
806 
807 	memcpy(&tab[slot], poke, sizeof(*poke));
808 	prog->aux->size_poke_tab = size;
809 	prog->aux->poke_tab = tab;
810 
811 	return slot;
812 }
813 
814 /*
815  * BPF program pack allocator.
816  *
817  * Most BPF programs are pretty small. Allocating a hole page for each
818  * program is sometime a waste. Many small bpf program also adds pressure
819  * to instruction TLB. To solve this issue, we introduce a BPF program pack
820  * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
821  * to host BPF programs.
822  */
823 #define BPF_PROG_CHUNK_SHIFT	6
824 #define BPF_PROG_CHUNK_SIZE	(1 << BPF_PROG_CHUNK_SHIFT)
825 #define BPF_PROG_CHUNK_MASK	(~(BPF_PROG_CHUNK_SIZE - 1))
826 
827 struct bpf_prog_pack {
828 	struct list_head list;
829 	void *ptr;
830 	unsigned long bitmap[];
831 };
832 
833 void bpf_jit_fill_hole_with_zero(void *area, unsigned int size)
834 {
835 	memset(area, 0, size);
836 }
837 
838 #define BPF_PROG_SIZE_TO_NBITS(size)	(round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
839 
840 static DEFINE_MUTEX(pack_mutex);
841 static LIST_HEAD(pack_list);
842 
843 /* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
844  * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
845  */
846 #ifdef PMD_SIZE
847 #define BPF_PROG_PACK_SIZE (PMD_SIZE * num_possible_nodes())
848 #else
849 #define BPF_PROG_PACK_SIZE PAGE_SIZE
850 #endif
851 
852 #define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
853 
854 static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
855 {
856 	struct bpf_prog_pack *pack;
857 
858 	pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)),
859 		       GFP_KERNEL);
860 	if (!pack)
861 		return NULL;
862 	pack->ptr = module_alloc(BPF_PROG_PACK_SIZE);
863 	if (!pack->ptr) {
864 		kfree(pack);
865 		return NULL;
866 	}
867 	bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
868 	bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
869 	list_add_tail(&pack->list, &pack_list);
870 
871 	set_vm_flush_reset_perms(pack->ptr);
872 	set_memory_rox((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE);
873 	return pack;
874 }
875 
876 void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
877 {
878 	unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
879 	struct bpf_prog_pack *pack;
880 	unsigned long pos;
881 	void *ptr = NULL;
882 
883 	mutex_lock(&pack_mutex);
884 	if (size > BPF_PROG_PACK_SIZE) {
885 		size = round_up(size, PAGE_SIZE);
886 		ptr = module_alloc(size);
887 		if (ptr) {
888 			bpf_fill_ill_insns(ptr, size);
889 			set_vm_flush_reset_perms(ptr);
890 			set_memory_rox((unsigned long)ptr, size / PAGE_SIZE);
891 		}
892 		goto out;
893 	}
894 	list_for_each_entry(pack, &pack_list, list) {
895 		pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
896 						 nbits, 0);
897 		if (pos < BPF_PROG_CHUNK_COUNT)
898 			goto found_free_area;
899 	}
900 
901 	pack = alloc_new_pack(bpf_fill_ill_insns);
902 	if (!pack)
903 		goto out;
904 
905 	pos = 0;
906 
907 found_free_area:
908 	bitmap_set(pack->bitmap, pos, nbits);
909 	ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
910 
911 out:
912 	mutex_unlock(&pack_mutex);
913 	return ptr;
914 }
915 
916 void bpf_prog_pack_free(struct bpf_binary_header *hdr)
917 {
918 	struct bpf_prog_pack *pack = NULL, *tmp;
919 	unsigned int nbits;
920 	unsigned long pos;
921 
922 	mutex_lock(&pack_mutex);
923 	if (hdr->size > BPF_PROG_PACK_SIZE) {
924 		module_memfree(hdr);
925 		goto out;
926 	}
927 
928 	list_for_each_entry(tmp, &pack_list, list) {
929 		if ((void *)hdr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > (void *)hdr) {
930 			pack = tmp;
931 			break;
932 		}
933 	}
934 
935 	if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
936 		goto out;
937 
938 	nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size);
939 	pos = ((unsigned long)hdr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
940 
941 	WARN_ONCE(bpf_arch_text_invalidate(hdr, hdr->size),
942 		  "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
943 
944 	bitmap_clear(pack->bitmap, pos, nbits);
945 	if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
946 				       BPF_PROG_CHUNK_COUNT, 0) == 0) {
947 		list_del(&pack->list);
948 		module_memfree(pack->ptr);
949 		kfree(pack);
950 	}
951 out:
952 	mutex_unlock(&pack_mutex);
953 }
954 
955 static atomic_long_t bpf_jit_current;
956 
957 /* Can be overridden by an arch's JIT compiler if it has a custom,
958  * dedicated BPF backend memory area, or if neither of the two
959  * below apply.
960  */
961 u64 __weak bpf_jit_alloc_exec_limit(void)
962 {
963 #if defined(MODULES_VADDR)
964 	return MODULES_END - MODULES_VADDR;
965 #else
966 	return VMALLOC_END - VMALLOC_START;
967 #endif
968 }
969 
970 static int __init bpf_jit_charge_init(void)
971 {
972 	/* Only used as heuristic here to derive limit. */
973 	bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
974 	bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 2,
975 					    PAGE_SIZE), LONG_MAX);
976 	return 0;
977 }
978 pure_initcall(bpf_jit_charge_init);
979 
980 int bpf_jit_charge_modmem(u32 size)
981 {
982 	if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
983 		if (!bpf_capable()) {
984 			atomic_long_sub(size, &bpf_jit_current);
985 			return -EPERM;
986 		}
987 	}
988 
989 	return 0;
990 }
991 
992 void bpf_jit_uncharge_modmem(u32 size)
993 {
994 	atomic_long_sub(size, &bpf_jit_current);
995 }
996 
997 void *__weak bpf_jit_alloc_exec(unsigned long size)
998 {
999 	return module_alloc(size);
1000 }
1001 
1002 void __weak bpf_jit_free_exec(void *addr)
1003 {
1004 	module_memfree(addr);
1005 }
1006 
1007 struct bpf_binary_header *
1008 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1009 		     unsigned int alignment,
1010 		     bpf_jit_fill_hole_t bpf_fill_ill_insns)
1011 {
1012 	struct bpf_binary_header *hdr;
1013 	u32 size, hole, start;
1014 
1015 	WARN_ON_ONCE(!is_power_of_2(alignment) ||
1016 		     alignment > BPF_IMAGE_ALIGNMENT);
1017 
1018 	/* Most of BPF filters are really small, but if some of them
1019 	 * fill a page, allow at least 128 extra bytes to insert a
1020 	 * random section of illegal instructions.
1021 	 */
1022 	size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
1023 
1024 	if (bpf_jit_charge_modmem(size))
1025 		return NULL;
1026 	hdr = bpf_jit_alloc_exec(size);
1027 	if (!hdr) {
1028 		bpf_jit_uncharge_modmem(size);
1029 		return NULL;
1030 	}
1031 
1032 	/* Fill space with illegal/arch-dep instructions. */
1033 	bpf_fill_ill_insns(hdr, size);
1034 
1035 	hdr->size = size;
1036 	hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
1037 		     PAGE_SIZE - sizeof(*hdr));
1038 	start = get_random_u32_below(hole) & ~(alignment - 1);
1039 
1040 	/* Leave a random number of instructions before BPF code. */
1041 	*image_ptr = &hdr->image[start];
1042 
1043 	return hdr;
1044 }
1045 
1046 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
1047 {
1048 	u32 size = hdr->size;
1049 
1050 	bpf_jit_free_exec(hdr);
1051 	bpf_jit_uncharge_modmem(size);
1052 }
1053 
1054 /* Allocate jit binary from bpf_prog_pack allocator.
1055  * Since the allocated memory is RO+X, the JIT engine cannot write directly
1056  * to the memory. To solve this problem, a RW buffer is also allocated at
1057  * as the same time. The JIT engine should calculate offsets based on the
1058  * RO memory address, but write JITed program to the RW buffer. Once the
1059  * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
1060  * the JITed program to the RO memory.
1061  */
1062 struct bpf_binary_header *
1063 bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
1064 			  unsigned int alignment,
1065 			  struct bpf_binary_header **rw_header,
1066 			  u8 **rw_image,
1067 			  bpf_jit_fill_hole_t bpf_fill_ill_insns)
1068 {
1069 	struct bpf_binary_header *ro_header;
1070 	u32 size, hole, start;
1071 
1072 	WARN_ON_ONCE(!is_power_of_2(alignment) ||
1073 		     alignment > BPF_IMAGE_ALIGNMENT);
1074 
1075 	/* add 16 bytes for a random section of illegal instructions */
1076 	size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
1077 
1078 	if (bpf_jit_charge_modmem(size))
1079 		return NULL;
1080 	ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns);
1081 	if (!ro_header) {
1082 		bpf_jit_uncharge_modmem(size);
1083 		return NULL;
1084 	}
1085 
1086 	*rw_header = kvmalloc(size, GFP_KERNEL);
1087 	if (!*rw_header) {
1088 		bpf_arch_text_copy(&ro_header->size, &size, sizeof(size));
1089 		bpf_prog_pack_free(ro_header);
1090 		bpf_jit_uncharge_modmem(size);
1091 		return NULL;
1092 	}
1093 
1094 	/* Fill space with illegal/arch-dep instructions. */
1095 	bpf_fill_ill_insns(*rw_header, size);
1096 	(*rw_header)->size = size;
1097 
1098 	hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
1099 		     BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
1100 	start = get_random_u32_below(hole) & ~(alignment - 1);
1101 
1102 	*image_ptr = &ro_header->image[start];
1103 	*rw_image = &(*rw_header)->image[start];
1104 
1105 	return ro_header;
1106 }
1107 
1108 /* Copy JITed text from rw_header to its final location, the ro_header. */
1109 int bpf_jit_binary_pack_finalize(struct bpf_prog *prog,
1110 				 struct bpf_binary_header *ro_header,
1111 				 struct bpf_binary_header *rw_header)
1112 {
1113 	void *ptr;
1114 
1115 	ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
1116 
1117 	kvfree(rw_header);
1118 
1119 	if (IS_ERR(ptr)) {
1120 		bpf_prog_pack_free(ro_header);
1121 		return PTR_ERR(ptr);
1122 	}
1123 	return 0;
1124 }
1125 
1126 /* bpf_jit_binary_pack_free is called in two different scenarios:
1127  *   1) when the program is freed after;
1128  *   2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
1129  * For case 2), we need to free both the RO memory and the RW buffer.
1130  *
1131  * bpf_jit_binary_pack_free requires proper ro_header->size. However,
1132  * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
1133  * must be set with either bpf_jit_binary_pack_finalize (normal path) or
1134  * bpf_arch_text_copy (when jit fails).
1135  */
1136 void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
1137 			      struct bpf_binary_header *rw_header)
1138 {
1139 	u32 size = ro_header->size;
1140 
1141 	bpf_prog_pack_free(ro_header);
1142 	kvfree(rw_header);
1143 	bpf_jit_uncharge_modmem(size);
1144 }
1145 
1146 struct bpf_binary_header *
1147 bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
1148 {
1149 	unsigned long real_start = (unsigned long)fp->bpf_func;
1150 	unsigned long addr;
1151 
1152 	addr = real_start & BPF_PROG_CHUNK_MASK;
1153 	return (void *)addr;
1154 }
1155 
1156 static inline struct bpf_binary_header *
1157 bpf_jit_binary_hdr(const struct bpf_prog *fp)
1158 {
1159 	unsigned long real_start = (unsigned long)fp->bpf_func;
1160 	unsigned long addr;
1161 
1162 	addr = real_start & PAGE_MASK;
1163 	return (void *)addr;
1164 }
1165 
1166 /* This symbol is only overridden by archs that have different
1167  * requirements than the usual eBPF JITs, f.e. when they only
1168  * implement cBPF JIT, do not set images read-only, etc.
1169  */
1170 void __weak bpf_jit_free(struct bpf_prog *fp)
1171 {
1172 	if (fp->jited) {
1173 		struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
1174 
1175 		bpf_jit_binary_free(hdr);
1176 		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
1177 	}
1178 
1179 	bpf_prog_unlock_free(fp);
1180 }
1181 
1182 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1183 			  const struct bpf_insn *insn, bool extra_pass,
1184 			  u64 *func_addr, bool *func_addr_fixed)
1185 {
1186 	s16 off = insn->off;
1187 	s32 imm = insn->imm;
1188 	u8 *addr;
1189 
1190 	*func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1191 	if (!*func_addr_fixed) {
1192 		/* Place-holder address till the last pass has collected
1193 		 * all addresses for JITed subprograms in which case we
1194 		 * can pick them up from prog->aux.
1195 		 */
1196 		if (!extra_pass)
1197 			addr = NULL;
1198 		else if (prog->aux->func &&
1199 			 off >= 0 && off < prog->aux->func_cnt)
1200 			addr = (u8 *)prog->aux->func[off]->bpf_func;
1201 		else
1202 			return -EINVAL;
1203 	} else {
1204 		/* Address of a BPF helper call. Since part of the core
1205 		 * kernel, it's always at a fixed location. __bpf_call_base
1206 		 * and the helper with imm relative to it are both in core
1207 		 * kernel.
1208 		 */
1209 		addr = (u8 *)__bpf_call_base + imm;
1210 	}
1211 
1212 	*func_addr = (unsigned long)addr;
1213 	return 0;
1214 }
1215 
1216 static int bpf_jit_blind_insn(const struct bpf_insn *from,
1217 			      const struct bpf_insn *aux,
1218 			      struct bpf_insn *to_buff,
1219 			      bool emit_zext)
1220 {
1221 	struct bpf_insn *to = to_buff;
1222 	u32 imm_rnd = get_random_u32();
1223 	s16 off;
1224 
1225 	BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
1226 	BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
1227 
1228 	/* Constraints on AX register:
1229 	 *
1230 	 * AX register is inaccessible from user space. It is mapped in
1231 	 * all JITs, and used here for constant blinding rewrites. It is
1232 	 * typically "stateless" meaning its contents are only valid within
1233 	 * the executed instruction, but not across several instructions.
1234 	 * There are a few exceptions however which are further detailed
1235 	 * below.
1236 	 *
1237 	 * Constant blinding is only used by JITs, not in the interpreter.
1238 	 * The interpreter uses AX in some occasions as a local temporary
1239 	 * register e.g. in DIV or MOD instructions.
1240 	 *
1241 	 * In restricted circumstances, the verifier can also use the AX
1242 	 * register for rewrites as long as they do not interfere with
1243 	 * the above cases!
1244 	 */
1245 	if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1246 		goto out;
1247 
1248 	if (from->imm == 0 &&
1249 	    (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
1250 	     from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1251 		*to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1252 		goto out;
1253 	}
1254 
1255 	switch (from->code) {
1256 	case BPF_ALU | BPF_ADD | BPF_K:
1257 	case BPF_ALU | BPF_SUB | BPF_K:
1258 	case BPF_ALU | BPF_AND | BPF_K:
1259 	case BPF_ALU | BPF_OR  | BPF_K:
1260 	case BPF_ALU | BPF_XOR | BPF_K:
1261 	case BPF_ALU | BPF_MUL | BPF_K:
1262 	case BPF_ALU | BPF_MOV | BPF_K:
1263 	case BPF_ALU | BPF_DIV | BPF_K:
1264 	case BPF_ALU | BPF_MOD | BPF_K:
1265 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1266 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1267 		*to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
1268 		break;
1269 
1270 	case BPF_ALU64 | BPF_ADD | BPF_K:
1271 	case BPF_ALU64 | BPF_SUB | BPF_K:
1272 	case BPF_ALU64 | BPF_AND | BPF_K:
1273 	case BPF_ALU64 | BPF_OR  | BPF_K:
1274 	case BPF_ALU64 | BPF_XOR | BPF_K:
1275 	case BPF_ALU64 | BPF_MUL | BPF_K:
1276 	case BPF_ALU64 | BPF_MOV | BPF_K:
1277 	case BPF_ALU64 | BPF_DIV | BPF_K:
1278 	case BPF_ALU64 | BPF_MOD | BPF_K:
1279 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1280 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1281 		*to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
1282 		break;
1283 
1284 	case BPF_JMP | BPF_JEQ  | BPF_K:
1285 	case BPF_JMP | BPF_JNE  | BPF_K:
1286 	case BPF_JMP | BPF_JGT  | BPF_K:
1287 	case BPF_JMP | BPF_JLT  | BPF_K:
1288 	case BPF_JMP | BPF_JGE  | BPF_K:
1289 	case BPF_JMP | BPF_JLE  | BPF_K:
1290 	case BPF_JMP | BPF_JSGT | BPF_K:
1291 	case BPF_JMP | BPF_JSLT | BPF_K:
1292 	case BPF_JMP | BPF_JSGE | BPF_K:
1293 	case BPF_JMP | BPF_JSLE | BPF_K:
1294 	case BPF_JMP | BPF_JSET | BPF_K:
1295 		/* Accommodate for extra offset in case of a backjump. */
1296 		off = from->off;
1297 		if (off < 0)
1298 			off -= 2;
1299 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1300 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1301 		*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1302 		break;
1303 
1304 	case BPF_JMP32 | BPF_JEQ  | BPF_K:
1305 	case BPF_JMP32 | BPF_JNE  | BPF_K:
1306 	case BPF_JMP32 | BPF_JGT  | BPF_K:
1307 	case BPF_JMP32 | BPF_JLT  | BPF_K:
1308 	case BPF_JMP32 | BPF_JGE  | BPF_K:
1309 	case BPF_JMP32 | BPF_JLE  | BPF_K:
1310 	case BPF_JMP32 | BPF_JSGT | BPF_K:
1311 	case BPF_JMP32 | BPF_JSLT | BPF_K:
1312 	case BPF_JMP32 | BPF_JSGE | BPF_K:
1313 	case BPF_JMP32 | BPF_JSLE | BPF_K:
1314 	case BPF_JMP32 | BPF_JSET | BPF_K:
1315 		/* Accommodate for extra offset in case of a backjump. */
1316 		off = from->off;
1317 		if (off < 0)
1318 			off -= 2;
1319 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1320 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1321 		*to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1322 				      off);
1323 		break;
1324 
1325 	case BPF_LD | BPF_IMM | BPF_DW:
1326 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1327 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1328 		*to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1329 		*to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1330 		break;
1331 	case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1332 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1333 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1334 		if (emit_zext)
1335 			*to++ = BPF_ZEXT_REG(BPF_REG_AX);
1336 		*to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
1337 		break;
1338 
1339 	case BPF_ST | BPF_MEM | BPF_DW:
1340 	case BPF_ST | BPF_MEM | BPF_W:
1341 	case BPF_ST | BPF_MEM | BPF_H:
1342 	case BPF_ST | BPF_MEM | BPF_B:
1343 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1344 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1345 		*to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1346 		break;
1347 	}
1348 out:
1349 	return to - to_buff;
1350 }
1351 
1352 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1353 					      gfp_t gfp_extra_flags)
1354 {
1355 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1356 	struct bpf_prog *fp;
1357 
1358 	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1359 	if (fp != NULL) {
1360 		/* aux->prog still points to the fp_other one, so
1361 		 * when promoting the clone to the real program,
1362 		 * this still needs to be adapted.
1363 		 */
1364 		memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1365 	}
1366 
1367 	return fp;
1368 }
1369 
1370 static void bpf_prog_clone_free(struct bpf_prog *fp)
1371 {
1372 	/* aux was stolen by the other clone, so we cannot free
1373 	 * it from this path! It will be freed eventually by the
1374 	 * other program on release.
1375 	 *
1376 	 * At this point, we don't need a deferred release since
1377 	 * clone is guaranteed to not be locked.
1378 	 */
1379 	fp->aux = NULL;
1380 	fp->stats = NULL;
1381 	fp->active = NULL;
1382 	__bpf_prog_free(fp);
1383 }
1384 
1385 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1386 {
1387 	/* We have to repoint aux->prog to self, as we don't
1388 	 * know whether fp here is the clone or the original.
1389 	 */
1390 	fp->aux->prog = fp;
1391 	bpf_prog_clone_free(fp_other);
1392 }
1393 
1394 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1395 {
1396 	struct bpf_insn insn_buff[16], aux[2];
1397 	struct bpf_prog *clone, *tmp;
1398 	int insn_delta, insn_cnt;
1399 	struct bpf_insn *insn;
1400 	int i, rewritten;
1401 
1402 	if (!prog->blinding_requested || prog->blinded)
1403 		return prog;
1404 
1405 	clone = bpf_prog_clone_create(prog, GFP_USER);
1406 	if (!clone)
1407 		return ERR_PTR(-ENOMEM);
1408 
1409 	insn_cnt = clone->len;
1410 	insn = clone->insnsi;
1411 
1412 	for (i = 0; i < insn_cnt; i++, insn++) {
1413 		if (bpf_pseudo_func(insn)) {
1414 			/* ld_imm64 with an address of bpf subprog is not
1415 			 * a user controlled constant. Don't randomize it,
1416 			 * since it will conflict with jit_subprogs() logic.
1417 			 */
1418 			insn++;
1419 			i++;
1420 			continue;
1421 		}
1422 
1423 		/* We temporarily need to hold the original ld64 insn
1424 		 * so that we can still access the first part in the
1425 		 * second blinding run.
1426 		 */
1427 		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1428 		    insn[1].code == 0)
1429 			memcpy(aux, insn, sizeof(aux));
1430 
1431 		rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1432 						clone->aux->verifier_zext);
1433 		if (!rewritten)
1434 			continue;
1435 
1436 		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1437 		if (IS_ERR(tmp)) {
1438 			/* Patching may have repointed aux->prog during
1439 			 * realloc from the original one, so we need to
1440 			 * fix it up here on error.
1441 			 */
1442 			bpf_jit_prog_release_other(prog, clone);
1443 			return tmp;
1444 		}
1445 
1446 		clone = tmp;
1447 		insn_delta = rewritten - 1;
1448 
1449 		/* Walk new program and skip insns we just inserted. */
1450 		insn = clone->insnsi + i + insn_delta;
1451 		insn_cnt += insn_delta;
1452 		i        += insn_delta;
1453 	}
1454 
1455 	clone->blinded = 1;
1456 	return clone;
1457 }
1458 #endif /* CONFIG_BPF_JIT */
1459 
1460 /* Base function for offset calculation. Needs to go into .text section,
1461  * therefore keeping it non-static as well; will also be used by JITs
1462  * anyway later on, so do not let the compiler omit it. This also needs
1463  * to go into kallsyms for correlation from e.g. bpftool, so naming
1464  * must not change.
1465  */
1466 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1467 {
1468 	return 0;
1469 }
1470 EXPORT_SYMBOL_GPL(__bpf_call_base);
1471 
1472 /* All UAPI available opcodes. */
1473 #define BPF_INSN_MAP(INSN_2, INSN_3)		\
1474 	/* 32 bit ALU operations. */		\
1475 	/*   Register based. */			\
1476 	INSN_3(ALU, ADD,  X),			\
1477 	INSN_3(ALU, SUB,  X),			\
1478 	INSN_3(ALU, AND,  X),			\
1479 	INSN_3(ALU, OR,   X),			\
1480 	INSN_3(ALU, LSH,  X),			\
1481 	INSN_3(ALU, RSH,  X),			\
1482 	INSN_3(ALU, XOR,  X),			\
1483 	INSN_3(ALU, MUL,  X),			\
1484 	INSN_3(ALU, MOV,  X),			\
1485 	INSN_3(ALU, ARSH, X),			\
1486 	INSN_3(ALU, DIV,  X),			\
1487 	INSN_3(ALU, MOD,  X),			\
1488 	INSN_2(ALU, NEG),			\
1489 	INSN_3(ALU, END, TO_BE),		\
1490 	INSN_3(ALU, END, TO_LE),		\
1491 	/*   Immediate based. */		\
1492 	INSN_3(ALU, ADD,  K),			\
1493 	INSN_3(ALU, SUB,  K),			\
1494 	INSN_3(ALU, AND,  K),			\
1495 	INSN_3(ALU, OR,   K),			\
1496 	INSN_3(ALU, LSH,  K),			\
1497 	INSN_3(ALU, RSH,  K),			\
1498 	INSN_3(ALU, XOR,  K),			\
1499 	INSN_3(ALU, MUL,  K),			\
1500 	INSN_3(ALU, MOV,  K),			\
1501 	INSN_3(ALU, ARSH, K),			\
1502 	INSN_3(ALU, DIV,  K),			\
1503 	INSN_3(ALU, MOD,  K),			\
1504 	/* 64 bit ALU operations. */		\
1505 	/*   Register based. */			\
1506 	INSN_3(ALU64, ADD,  X),			\
1507 	INSN_3(ALU64, SUB,  X),			\
1508 	INSN_3(ALU64, AND,  X),			\
1509 	INSN_3(ALU64, OR,   X),			\
1510 	INSN_3(ALU64, LSH,  X),			\
1511 	INSN_3(ALU64, RSH,  X),			\
1512 	INSN_3(ALU64, XOR,  X),			\
1513 	INSN_3(ALU64, MUL,  X),			\
1514 	INSN_3(ALU64, MOV,  X),			\
1515 	INSN_3(ALU64, ARSH, X),			\
1516 	INSN_3(ALU64, DIV,  X),			\
1517 	INSN_3(ALU64, MOD,  X),			\
1518 	INSN_2(ALU64, NEG),			\
1519 	/*   Immediate based. */		\
1520 	INSN_3(ALU64, ADD,  K),			\
1521 	INSN_3(ALU64, SUB,  K),			\
1522 	INSN_3(ALU64, AND,  K),			\
1523 	INSN_3(ALU64, OR,   K),			\
1524 	INSN_3(ALU64, LSH,  K),			\
1525 	INSN_3(ALU64, RSH,  K),			\
1526 	INSN_3(ALU64, XOR,  K),			\
1527 	INSN_3(ALU64, MUL,  K),			\
1528 	INSN_3(ALU64, MOV,  K),			\
1529 	INSN_3(ALU64, ARSH, K),			\
1530 	INSN_3(ALU64, DIV,  K),			\
1531 	INSN_3(ALU64, MOD,  K),			\
1532 	/* Call instruction. */			\
1533 	INSN_2(JMP, CALL),			\
1534 	/* Exit instruction. */			\
1535 	INSN_2(JMP, EXIT),			\
1536 	/* 32-bit Jump instructions. */		\
1537 	/*   Register based. */			\
1538 	INSN_3(JMP32, JEQ,  X),			\
1539 	INSN_3(JMP32, JNE,  X),			\
1540 	INSN_3(JMP32, JGT,  X),			\
1541 	INSN_3(JMP32, JLT,  X),			\
1542 	INSN_3(JMP32, JGE,  X),			\
1543 	INSN_3(JMP32, JLE,  X),			\
1544 	INSN_3(JMP32, JSGT, X),			\
1545 	INSN_3(JMP32, JSLT, X),			\
1546 	INSN_3(JMP32, JSGE, X),			\
1547 	INSN_3(JMP32, JSLE, X),			\
1548 	INSN_3(JMP32, JSET, X),			\
1549 	/*   Immediate based. */		\
1550 	INSN_3(JMP32, JEQ,  K),			\
1551 	INSN_3(JMP32, JNE,  K),			\
1552 	INSN_3(JMP32, JGT,  K),			\
1553 	INSN_3(JMP32, JLT,  K),			\
1554 	INSN_3(JMP32, JGE,  K),			\
1555 	INSN_3(JMP32, JLE,  K),			\
1556 	INSN_3(JMP32, JSGT, K),			\
1557 	INSN_3(JMP32, JSLT, K),			\
1558 	INSN_3(JMP32, JSGE, K),			\
1559 	INSN_3(JMP32, JSLE, K),			\
1560 	INSN_3(JMP32, JSET, K),			\
1561 	/* Jump instructions. */		\
1562 	/*   Register based. */			\
1563 	INSN_3(JMP, JEQ,  X),			\
1564 	INSN_3(JMP, JNE,  X),			\
1565 	INSN_3(JMP, JGT,  X),			\
1566 	INSN_3(JMP, JLT,  X),			\
1567 	INSN_3(JMP, JGE,  X),			\
1568 	INSN_3(JMP, JLE,  X),			\
1569 	INSN_3(JMP, JSGT, X),			\
1570 	INSN_3(JMP, JSLT, X),			\
1571 	INSN_3(JMP, JSGE, X),			\
1572 	INSN_3(JMP, JSLE, X),			\
1573 	INSN_3(JMP, JSET, X),			\
1574 	/*   Immediate based. */		\
1575 	INSN_3(JMP, JEQ,  K),			\
1576 	INSN_3(JMP, JNE,  K),			\
1577 	INSN_3(JMP, JGT,  K),			\
1578 	INSN_3(JMP, JLT,  K),			\
1579 	INSN_3(JMP, JGE,  K),			\
1580 	INSN_3(JMP, JLE,  K),			\
1581 	INSN_3(JMP, JSGT, K),			\
1582 	INSN_3(JMP, JSLT, K),			\
1583 	INSN_3(JMP, JSGE, K),			\
1584 	INSN_3(JMP, JSLE, K),			\
1585 	INSN_3(JMP, JSET, K),			\
1586 	INSN_2(JMP, JA),			\
1587 	/* Store instructions. */		\
1588 	/*   Register based. */			\
1589 	INSN_3(STX, MEM,  B),			\
1590 	INSN_3(STX, MEM,  H),			\
1591 	INSN_3(STX, MEM,  W),			\
1592 	INSN_3(STX, MEM,  DW),			\
1593 	INSN_3(STX, ATOMIC, W),			\
1594 	INSN_3(STX, ATOMIC, DW),		\
1595 	/*   Immediate based. */		\
1596 	INSN_3(ST, MEM, B),			\
1597 	INSN_3(ST, MEM, H),			\
1598 	INSN_3(ST, MEM, W),			\
1599 	INSN_3(ST, MEM, DW),			\
1600 	/* Load instructions. */		\
1601 	/*   Register based. */			\
1602 	INSN_3(LDX, MEM, B),			\
1603 	INSN_3(LDX, MEM, H),			\
1604 	INSN_3(LDX, MEM, W),			\
1605 	INSN_3(LDX, MEM, DW),			\
1606 	/*   Immediate based. */		\
1607 	INSN_3(LD, IMM, DW)
1608 
1609 bool bpf_opcode_in_insntable(u8 code)
1610 {
1611 #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
1612 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1613 	static const bool public_insntable[256] = {
1614 		[0 ... 255] = false,
1615 		/* Now overwrite non-defaults ... */
1616 		BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1617 		/* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1618 		[BPF_LD | BPF_ABS | BPF_B] = true,
1619 		[BPF_LD | BPF_ABS | BPF_H] = true,
1620 		[BPF_LD | BPF_ABS | BPF_W] = true,
1621 		[BPF_LD | BPF_IND | BPF_B] = true,
1622 		[BPF_LD | BPF_IND | BPF_H] = true,
1623 		[BPF_LD | BPF_IND | BPF_W] = true,
1624 	};
1625 #undef BPF_INSN_3_TBL
1626 #undef BPF_INSN_2_TBL
1627 	return public_insntable[code];
1628 }
1629 
1630 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1631 u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
1632 {
1633 	memset(dst, 0, size);
1634 	return -EFAULT;
1635 }
1636 
1637 /**
1638  *	___bpf_prog_run - run eBPF program on a given context
1639  *	@regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1640  *	@insn: is the array of eBPF instructions
1641  *
1642  * Decode and execute eBPF instructions.
1643  *
1644  * Return: whatever value is in %BPF_R0 at program exit
1645  */
1646 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1647 {
1648 #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
1649 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1650 	static const void * const jumptable[256] __annotate_jump_table = {
1651 		[0 ... 255] = &&default_label,
1652 		/* Now overwrite non-defaults ... */
1653 		BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1654 		/* Non-UAPI available opcodes. */
1655 		[BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1656 		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1657 		[BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
1658 		[BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1659 		[BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1660 		[BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1661 		[BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1662 	};
1663 #undef BPF_INSN_3_LBL
1664 #undef BPF_INSN_2_LBL
1665 	u32 tail_call_cnt = 0;
1666 
1667 #define CONT	 ({ insn++; goto select_insn; })
1668 #define CONT_JMP ({ insn++; goto select_insn; })
1669 
1670 select_insn:
1671 	goto *jumptable[insn->code];
1672 
1673 	/* Explicitly mask the register-based shift amounts with 63 or 31
1674 	 * to avoid undefined behavior. Normally this won't affect the
1675 	 * generated code, for example, in case of native 64 bit archs such
1676 	 * as x86-64 or arm64, the compiler is optimizing the AND away for
1677 	 * the interpreter. In case of JITs, each of the JIT backends compiles
1678 	 * the BPF shift operations to machine instructions which produce
1679 	 * implementation-defined results in such a case; the resulting
1680 	 * contents of the register may be arbitrary, but program behaviour
1681 	 * as a whole remains defined. In other words, in case of JIT backends,
1682 	 * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1683 	 */
1684 	/* ALU (shifts) */
1685 #define SHT(OPCODE, OP)					\
1686 	ALU64_##OPCODE##_X:				\
1687 		DST = DST OP (SRC & 63);		\
1688 		CONT;					\
1689 	ALU_##OPCODE##_X:				\
1690 		DST = (u32) DST OP ((u32) SRC & 31);	\
1691 		CONT;					\
1692 	ALU64_##OPCODE##_K:				\
1693 		DST = DST OP IMM;			\
1694 		CONT;					\
1695 	ALU_##OPCODE##_K:				\
1696 		DST = (u32) DST OP (u32) IMM;		\
1697 		CONT;
1698 	/* ALU (rest) */
1699 #define ALU(OPCODE, OP)					\
1700 	ALU64_##OPCODE##_X:				\
1701 		DST = DST OP SRC;			\
1702 		CONT;					\
1703 	ALU_##OPCODE##_X:				\
1704 		DST = (u32) DST OP (u32) SRC;		\
1705 		CONT;					\
1706 	ALU64_##OPCODE##_K:				\
1707 		DST = DST OP IMM;			\
1708 		CONT;					\
1709 	ALU_##OPCODE##_K:				\
1710 		DST = (u32) DST OP (u32) IMM;		\
1711 		CONT;
1712 	ALU(ADD,  +)
1713 	ALU(SUB,  -)
1714 	ALU(AND,  &)
1715 	ALU(OR,   |)
1716 	ALU(XOR,  ^)
1717 	ALU(MUL,  *)
1718 	SHT(LSH, <<)
1719 	SHT(RSH, >>)
1720 #undef SHT
1721 #undef ALU
1722 	ALU_NEG:
1723 		DST = (u32) -DST;
1724 		CONT;
1725 	ALU64_NEG:
1726 		DST = -DST;
1727 		CONT;
1728 	ALU_MOV_X:
1729 		DST = (u32) SRC;
1730 		CONT;
1731 	ALU_MOV_K:
1732 		DST = (u32) IMM;
1733 		CONT;
1734 	ALU64_MOV_X:
1735 		DST = SRC;
1736 		CONT;
1737 	ALU64_MOV_K:
1738 		DST = IMM;
1739 		CONT;
1740 	LD_IMM_DW:
1741 		DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1742 		insn++;
1743 		CONT;
1744 	ALU_ARSH_X:
1745 		DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1746 		CONT;
1747 	ALU_ARSH_K:
1748 		DST = (u64) (u32) (((s32) DST) >> IMM);
1749 		CONT;
1750 	ALU64_ARSH_X:
1751 		(*(s64 *) &DST) >>= (SRC & 63);
1752 		CONT;
1753 	ALU64_ARSH_K:
1754 		(*(s64 *) &DST) >>= IMM;
1755 		CONT;
1756 	ALU64_MOD_X:
1757 		div64_u64_rem(DST, SRC, &AX);
1758 		DST = AX;
1759 		CONT;
1760 	ALU_MOD_X:
1761 		AX = (u32) DST;
1762 		DST = do_div(AX, (u32) SRC);
1763 		CONT;
1764 	ALU64_MOD_K:
1765 		div64_u64_rem(DST, IMM, &AX);
1766 		DST = AX;
1767 		CONT;
1768 	ALU_MOD_K:
1769 		AX = (u32) DST;
1770 		DST = do_div(AX, (u32) IMM);
1771 		CONT;
1772 	ALU64_DIV_X:
1773 		DST = div64_u64(DST, SRC);
1774 		CONT;
1775 	ALU_DIV_X:
1776 		AX = (u32) DST;
1777 		do_div(AX, (u32) SRC);
1778 		DST = (u32) AX;
1779 		CONT;
1780 	ALU64_DIV_K:
1781 		DST = div64_u64(DST, IMM);
1782 		CONT;
1783 	ALU_DIV_K:
1784 		AX = (u32) DST;
1785 		do_div(AX, (u32) IMM);
1786 		DST = (u32) AX;
1787 		CONT;
1788 	ALU_END_TO_BE:
1789 		switch (IMM) {
1790 		case 16:
1791 			DST = (__force u16) cpu_to_be16(DST);
1792 			break;
1793 		case 32:
1794 			DST = (__force u32) cpu_to_be32(DST);
1795 			break;
1796 		case 64:
1797 			DST = (__force u64) cpu_to_be64(DST);
1798 			break;
1799 		}
1800 		CONT;
1801 	ALU_END_TO_LE:
1802 		switch (IMM) {
1803 		case 16:
1804 			DST = (__force u16) cpu_to_le16(DST);
1805 			break;
1806 		case 32:
1807 			DST = (__force u32) cpu_to_le32(DST);
1808 			break;
1809 		case 64:
1810 			DST = (__force u64) cpu_to_le64(DST);
1811 			break;
1812 		}
1813 		CONT;
1814 
1815 	/* CALL */
1816 	JMP_CALL:
1817 		/* Function call scratches BPF_R1-BPF_R5 registers,
1818 		 * preserves BPF_R6-BPF_R9, and stores return value
1819 		 * into BPF_R0.
1820 		 */
1821 		BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1822 						       BPF_R4, BPF_R5);
1823 		CONT;
1824 
1825 	JMP_CALL_ARGS:
1826 		BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
1827 							    BPF_R3, BPF_R4,
1828 							    BPF_R5,
1829 							    insn + insn->off + 1);
1830 		CONT;
1831 
1832 	JMP_TAIL_CALL: {
1833 		struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1834 		struct bpf_array *array = container_of(map, struct bpf_array, map);
1835 		struct bpf_prog *prog;
1836 		u32 index = BPF_R3;
1837 
1838 		if (unlikely(index >= array->map.max_entries))
1839 			goto out;
1840 
1841 		if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
1842 			goto out;
1843 
1844 		tail_call_cnt++;
1845 
1846 		prog = READ_ONCE(array->ptrs[index]);
1847 		if (!prog)
1848 			goto out;
1849 
1850 		/* ARG1 at this point is guaranteed to point to CTX from
1851 		 * the verifier side due to the fact that the tail call is
1852 		 * handled like a helper, that is, bpf_tail_call_proto,
1853 		 * where arg1_type is ARG_PTR_TO_CTX.
1854 		 */
1855 		insn = prog->insnsi;
1856 		goto select_insn;
1857 out:
1858 		CONT;
1859 	}
1860 	JMP_JA:
1861 		insn += insn->off;
1862 		CONT;
1863 	JMP_EXIT:
1864 		return BPF_R0;
1865 	/* JMP */
1866 #define COND_JMP(SIGN, OPCODE, CMP_OP)				\
1867 	JMP_##OPCODE##_X:					\
1868 		if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {	\
1869 			insn += insn->off;			\
1870 			CONT_JMP;				\
1871 		}						\
1872 		CONT;						\
1873 	JMP32_##OPCODE##_X:					\
1874 		if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {	\
1875 			insn += insn->off;			\
1876 			CONT_JMP;				\
1877 		}						\
1878 		CONT;						\
1879 	JMP_##OPCODE##_K:					\
1880 		if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {	\
1881 			insn += insn->off;			\
1882 			CONT_JMP;				\
1883 		}						\
1884 		CONT;						\
1885 	JMP32_##OPCODE##_K:					\
1886 		if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {	\
1887 			insn += insn->off;			\
1888 			CONT_JMP;				\
1889 		}						\
1890 		CONT;
1891 	COND_JMP(u, JEQ, ==)
1892 	COND_JMP(u, JNE, !=)
1893 	COND_JMP(u, JGT, >)
1894 	COND_JMP(u, JLT, <)
1895 	COND_JMP(u, JGE, >=)
1896 	COND_JMP(u, JLE, <=)
1897 	COND_JMP(u, JSET, &)
1898 	COND_JMP(s, JSGT, >)
1899 	COND_JMP(s, JSLT, <)
1900 	COND_JMP(s, JSGE, >=)
1901 	COND_JMP(s, JSLE, <=)
1902 #undef COND_JMP
1903 	/* ST, STX and LDX*/
1904 	ST_NOSPEC:
1905 		/* Speculation barrier for mitigating Speculative Store Bypass.
1906 		 * In case of arm64, we rely on the firmware mitigation as
1907 		 * controlled via the ssbd kernel parameter. Whenever the
1908 		 * mitigation is enabled, it works for all of the kernel code
1909 		 * with no need to provide any additional instructions here.
1910 		 * In case of x86, we use 'lfence' insn for mitigation. We
1911 		 * reuse preexisting logic from Spectre v1 mitigation that
1912 		 * happens to produce the required code on x86 for v4 as well.
1913 		 */
1914 #ifdef CONFIG_X86
1915 		barrier_nospec();
1916 #endif
1917 		CONT;
1918 #define LDST(SIZEOP, SIZE)						\
1919 	STX_MEM_##SIZEOP:						\
1920 		*(SIZE *)(unsigned long) (DST + insn->off) = SRC;	\
1921 		CONT;							\
1922 	ST_MEM_##SIZEOP:						\
1923 		*(SIZE *)(unsigned long) (DST + insn->off) = IMM;	\
1924 		CONT;							\
1925 	LDX_MEM_##SIZEOP:						\
1926 		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
1927 		CONT;							\
1928 	LDX_PROBE_MEM_##SIZEOP:						\
1929 		bpf_probe_read_kernel(&DST, sizeof(SIZE),		\
1930 				      (const void *)(long) (SRC + insn->off));	\
1931 		DST = *((SIZE *)&DST);					\
1932 		CONT;
1933 
1934 	LDST(B,   u8)
1935 	LDST(H,  u16)
1936 	LDST(W,  u32)
1937 	LDST(DW, u64)
1938 #undef LDST
1939 
1940 #define ATOMIC_ALU_OP(BOP, KOP)						\
1941 		case BOP:						\
1942 			if (BPF_SIZE(insn->code) == BPF_W)		\
1943 				atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
1944 					     (DST + insn->off));	\
1945 			else						\
1946 				atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
1947 					       (DST + insn->off));	\
1948 			break;						\
1949 		case BOP | BPF_FETCH:					\
1950 			if (BPF_SIZE(insn->code) == BPF_W)		\
1951 				SRC = (u32) atomic_fetch_##KOP(		\
1952 					(u32) SRC,			\
1953 					(atomic_t *)(unsigned long) (DST + insn->off)); \
1954 			else						\
1955 				SRC = (u64) atomic64_fetch_##KOP(	\
1956 					(u64) SRC,			\
1957 					(atomic64_t *)(unsigned long) (DST + insn->off)); \
1958 			break;
1959 
1960 	STX_ATOMIC_DW:
1961 	STX_ATOMIC_W:
1962 		switch (IMM) {
1963 		ATOMIC_ALU_OP(BPF_ADD, add)
1964 		ATOMIC_ALU_OP(BPF_AND, and)
1965 		ATOMIC_ALU_OP(BPF_OR, or)
1966 		ATOMIC_ALU_OP(BPF_XOR, xor)
1967 #undef ATOMIC_ALU_OP
1968 
1969 		case BPF_XCHG:
1970 			if (BPF_SIZE(insn->code) == BPF_W)
1971 				SRC = (u32) atomic_xchg(
1972 					(atomic_t *)(unsigned long) (DST + insn->off),
1973 					(u32) SRC);
1974 			else
1975 				SRC = (u64) atomic64_xchg(
1976 					(atomic64_t *)(unsigned long) (DST + insn->off),
1977 					(u64) SRC);
1978 			break;
1979 		case BPF_CMPXCHG:
1980 			if (BPF_SIZE(insn->code) == BPF_W)
1981 				BPF_R0 = (u32) atomic_cmpxchg(
1982 					(atomic_t *)(unsigned long) (DST + insn->off),
1983 					(u32) BPF_R0, (u32) SRC);
1984 			else
1985 				BPF_R0 = (u64) atomic64_cmpxchg(
1986 					(atomic64_t *)(unsigned long) (DST + insn->off),
1987 					(u64) BPF_R0, (u64) SRC);
1988 			break;
1989 
1990 		default:
1991 			goto default_label;
1992 		}
1993 		CONT;
1994 
1995 	default_label:
1996 		/* If we ever reach this, we have a bug somewhere. Die hard here
1997 		 * instead of just returning 0; we could be somewhere in a subprog,
1998 		 * so execution could continue otherwise which we do /not/ want.
1999 		 *
2000 		 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2001 		 */
2002 		pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2003 			insn->code, insn->imm);
2004 		BUG_ON(1);
2005 		return 0;
2006 }
2007 
2008 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2009 #define DEFINE_BPF_PROG_RUN(stack_size) \
2010 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2011 { \
2012 	u64 stack[stack_size / sizeof(u64)]; \
2013 	u64 regs[MAX_BPF_EXT_REG] = {}; \
2014 \
2015 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2016 	ARG1 = (u64) (unsigned long) ctx; \
2017 	return ___bpf_prog_run(regs, insn); \
2018 }
2019 
2020 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2021 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2022 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2023 				      const struct bpf_insn *insn) \
2024 { \
2025 	u64 stack[stack_size / sizeof(u64)]; \
2026 	u64 regs[MAX_BPF_EXT_REG]; \
2027 \
2028 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2029 	BPF_R1 = r1; \
2030 	BPF_R2 = r2; \
2031 	BPF_R3 = r3; \
2032 	BPF_R4 = r4; \
2033 	BPF_R5 = r5; \
2034 	return ___bpf_prog_run(regs, insn); \
2035 }
2036 
2037 #define EVAL1(FN, X) FN(X)
2038 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2039 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2040 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2041 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2042 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2043 
2044 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2045 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2046 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2047 
2048 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2049 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2050 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2051 
2052 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2053 
2054 static unsigned int (*interpreters[])(const void *ctx,
2055 				      const struct bpf_insn *insn) = {
2056 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2057 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2058 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2059 };
2060 #undef PROG_NAME_LIST
2061 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2062 static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2063 				  const struct bpf_insn *insn) = {
2064 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2065 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2066 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2067 };
2068 #undef PROG_NAME_LIST
2069 
2070 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2071 {
2072 	stack_depth = max_t(u32, stack_depth, 1);
2073 	insn->off = (s16) insn->imm;
2074 	insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
2075 		__bpf_call_base_args;
2076 	insn->code = BPF_JMP | BPF_CALL_ARGS;
2077 }
2078 
2079 #else
2080 static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2081 					 const struct bpf_insn *insn)
2082 {
2083 	/* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2084 	 * is not working properly, so warn about it!
2085 	 */
2086 	WARN_ON_ONCE(1);
2087 	return 0;
2088 }
2089 #endif
2090 
2091 bool bpf_prog_map_compatible(struct bpf_map *map,
2092 			     const struct bpf_prog *fp)
2093 {
2094 	enum bpf_prog_type prog_type = resolve_prog_type(fp);
2095 	bool ret;
2096 
2097 	if (fp->kprobe_override)
2098 		return false;
2099 
2100 	/* XDP programs inserted into maps are not guaranteed to run on
2101 	 * a particular netdev (and can run outside driver context entirely
2102 	 * in the case of devmap and cpumap). Until device checks
2103 	 * are implemented, prohibit adding dev-bound programs to program maps.
2104 	 */
2105 	if (bpf_prog_is_dev_bound(fp->aux))
2106 		return false;
2107 
2108 	spin_lock(&map->owner.lock);
2109 	if (!map->owner.type) {
2110 		/* There's no owner yet where we could check for
2111 		 * compatibility.
2112 		 */
2113 		map->owner.type  = prog_type;
2114 		map->owner.jited = fp->jited;
2115 		map->owner.xdp_has_frags = fp->aux->xdp_has_frags;
2116 		ret = true;
2117 	} else {
2118 		ret = map->owner.type  == prog_type &&
2119 		      map->owner.jited == fp->jited &&
2120 		      map->owner.xdp_has_frags == fp->aux->xdp_has_frags;
2121 	}
2122 	spin_unlock(&map->owner.lock);
2123 
2124 	return ret;
2125 }
2126 
2127 static int bpf_check_tail_call(const struct bpf_prog *fp)
2128 {
2129 	struct bpf_prog_aux *aux = fp->aux;
2130 	int i, ret = 0;
2131 
2132 	mutex_lock(&aux->used_maps_mutex);
2133 	for (i = 0; i < aux->used_map_cnt; i++) {
2134 		struct bpf_map *map = aux->used_maps[i];
2135 
2136 		if (!map_type_contains_progs(map))
2137 			continue;
2138 
2139 		if (!bpf_prog_map_compatible(map, fp)) {
2140 			ret = -EINVAL;
2141 			goto out;
2142 		}
2143 	}
2144 
2145 out:
2146 	mutex_unlock(&aux->used_maps_mutex);
2147 	return ret;
2148 }
2149 
2150 static void bpf_prog_select_func(struct bpf_prog *fp)
2151 {
2152 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
2153 	u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2154 
2155 	fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
2156 #else
2157 	fp->bpf_func = __bpf_prog_ret0_warn;
2158 #endif
2159 }
2160 
2161 /**
2162  *	bpf_prog_select_runtime - select exec runtime for BPF program
2163  *	@fp: bpf_prog populated with BPF program
2164  *	@err: pointer to error variable
2165  *
2166  * Try to JIT eBPF program, if JIT is not available, use interpreter.
2167  * The BPF program will be executed via bpf_prog_run() function.
2168  *
2169  * Return: the &fp argument along with &err set to 0 for success or
2170  * a negative errno code on failure
2171  */
2172 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2173 {
2174 	/* In case of BPF to BPF calls, verifier did all the prep
2175 	 * work with regards to JITing, etc.
2176 	 */
2177 	bool jit_needed = false;
2178 
2179 	if (fp->bpf_func)
2180 		goto finalize;
2181 
2182 	if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
2183 	    bpf_prog_has_kfunc_call(fp))
2184 		jit_needed = true;
2185 
2186 	bpf_prog_select_func(fp);
2187 
2188 	/* eBPF JITs can rewrite the program in case constant
2189 	 * blinding is active. However, in case of error during
2190 	 * blinding, bpf_int_jit_compile() must always return a
2191 	 * valid program, which in this case would simply not
2192 	 * be JITed, but falls back to the interpreter.
2193 	 */
2194 	if (!bpf_prog_is_offloaded(fp->aux)) {
2195 		*err = bpf_prog_alloc_jited_linfo(fp);
2196 		if (*err)
2197 			return fp;
2198 
2199 		fp = bpf_int_jit_compile(fp);
2200 		bpf_prog_jit_attempt_done(fp);
2201 		if (!fp->jited && jit_needed) {
2202 			*err = -ENOTSUPP;
2203 			return fp;
2204 		}
2205 	} else {
2206 		*err = bpf_prog_offload_compile(fp);
2207 		if (*err)
2208 			return fp;
2209 	}
2210 
2211 finalize:
2212 	bpf_prog_lock_ro(fp);
2213 
2214 	/* The tail call compatibility check can only be done at
2215 	 * this late stage as we need to determine, if we deal
2216 	 * with JITed or non JITed program concatenations and not
2217 	 * all eBPF JITs might immediately support all features.
2218 	 */
2219 	*err = bpf_check_tail_call(fp);
2220 
2221 	return fp;
2222 }
2223 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2224 
2225 static unsigned int __bpf_prog_ret1(const void *ctx,
2226 				    const struct bpf_insn *insn)
2227 {
2228 	return 1;
2229 }
2230 
2231 static struct bpf_prog_dummy {
2232 	struct bpf_prog prog;
2233 } dummy_bpf_prog = {
2234 	.prog = {
2235 		.bpf_func = __bpf_prog_ret1,
2236 	},
2237 };
2238 
2239 struct bpf_empty_prog_array bpf_empty_prog_array = {
2240 	.null_prog = NULL,
2241 };
2242 EXPORT_SYMBOL(bpf_empty_prog_array);
2243 
2244 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2245 {
2246 	if (prog_cnt)
2247 		return kzalloc(sizeof(struct bpf_prog_array) +
2248 			       sizeof(struct bpf_prog_array_item) *
2249 			       (prog_cnt + 1),
2250 			       flags);
2251 
2252 	return &bpf_empty_prog_array.hdr;
2253 }
2254 
2255 void bpf_prog_array_free(struct bpf_prog_array *progs)
2256 {
2257 	if (!progs || progs == &bpf_empty_prog_array.hdr)
2258 		return;
2259 	kfree_rcu(progs, rcu);
2260 }
2261 
2262 static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2263 {
2264 	struct bpf_prog_array *progs;
2265 
2266 	/* If RCU Tasks Trace grace period implies RCU grace period, there is
2267 	 * no need to call kfree_rcu(), just call kfree() directly.
2268 	 */
2269 	progs = container_of(rcu, struct bpf_prog_array, rcu);
2270 	if (rcu_trace_implies_rcu_gp())
2271 		kfree(progs);
2272 	else
2273 		kfree_rcu(progs, rcu);
2274 }
2275 
2276 void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2277 {
2278 	if (!progs || progs == &bpf_empty_prog_array.hdr)
2279 		return;
2280 	call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2281 }
2282 
2283 int bpf_prog_array_length(struct bpf_prog_array *array)
2284 {
2285 	struct bpf_prog_array_item *item;
2286 	u32 cnt = 0;
2287 
2288 	for (item = array->items; item->prog; item++)
2289 		if (item->prog != &dummy_bpf_prog.prog)
2290 			cnt++;
2291 	return cnt;
2292 }
2293 
2294 bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2295 {
2296 	struct bpf_prog_array_item *item;
2297 
2298 	for (item = array->items; item->prog; item++)
2299 		if (item->prog != &dummy_bpf_prog.prog)
2300 			return false;
2301 	return true;
2302 }
2303 
2304 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2305 				     u32 *prog_ids,
2306 				     u32 request_cnt)
2307 {
2308 	struct bpf_prog_array_item *item;
2309 	int i = 0;
2310 
2311 	for (item = array->items; item->prog; item++) {
2312 		if (item->prog == &dummy_bpf_prog.prog)
2313 			continue;
2314 		prog_ids[i] = item->prog->aux->id;
2315 		if (++i == request_cnt) {
2316 			item++;
2317 			break;
2318 		}
2319 	}
2320 
2321 	return !!(item->prog);
2322 }
2323 
2324 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2325 				__u32 __user *prog_ids, u32 cnt)
2326 {
2327 	unsigned long err = 0;
2328 	bool nospc;
2329 	u32 *ids;
2330 
2331 	/* users of this function are doing:
2332 	 * cnt = bpf_prog_array_length();
2333 	 * if (cnt > 0)
2334 	 *     bpf_prog_array_copy_to_user(..., cnt);
2335 	 * so below kcalloc doesn't need extra cnt > 0 check.
2336 	 */
2337 	ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2338 	if (!ids)
2339 		return -ENOMEM;
2340 	nospc = bpf_prog_array_copy_core(array, ids, cnt);
2341 	err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2342 	kfree(ids);
2343 	if (err)
2344 		return -EFAULT;
2345 	if (nospc)
2346 		return -ENOSPC;
2347 	return 0;
2348 }
2349 
2350 void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2351 				struct bpf_prog *old_prog)
2352 {
2353 	struct bpf_prog_array_item *item;
2354 
2355 	for (item = array->items; item->prog; item++)
2356 		if (item->prog == old_prog) {
2357 			WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2358 			break;
2359 		}
2360 }
2361 
2362 /**
2363  * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2364  *                                   index into the program array with
2365  *                                   a dummy no-op program.
2366  * @array: a bpf_prog_array
2367  * @index: the index of the program to replace
2368  *
2369  * Skips over dummy programs, by not counting them, when calculating
2370  * the position of the program to replace.
2371  *
2372  * Return:
2373  * * 0		- Success
2374  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2375  * * -ENOENT	- Index out of range
2376  */
2377 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2378 {
2379 	return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2380 }
2381 
2382 /**
2383  * bpf_prog_array_update_at() - Updates the program at the given index
2384  *                              into the program array.
2385  * @array: a bpf_prog_array
2386  * @index: the index of the program to update
2387  * @prog: the program to insert into the array
2388  *
2389  * Skips over dummy programs, by not counting them, when calculating
2390  * the position of the program to update.
2391  *
2392  * Return:
2393  * * 0		- Success
2394  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2395  * * -ENOENT	- Index out of range
2396  */
2397 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2398 			     struct bpf_prog *prog)
2399 {
2400 	struct bpf_prog_array_item *item;
2401 
2402 	if (unlikely(index < 0))
2403 		return -EINVAL;
2404 
2405 	for (item = array->items; item->prog; item++) {
2406 		if (item->prog == &dummy_bpf_prog.prog)
2407 			continue;
2408 		if (!index) {
2409 			WRITE_ONCE(item->prog, prog);
2410 			return 0;
2411 		}
2412 		index--;
2413 	}
2414 	return -ENOENT;
2415 }
2416 
2417 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2418 			struct bpf_prog *exclude_prog,
2419 			struct bpf_prog *include_prog,
2420 			u64 bpf_cookie,
2421 			struct bpf_prog_array **new_array)
2422 {
2423 	int new_prog_cnt, carry_prog_cnt = 0;
2424 	struct bpf_prog_array_item *existing, *new;
2425 	struct bpf_prog_array *array;
2426 	bool found_exclude = false;
2427 
2428 	/* Figure out how many existing progs we need to carry over to
2429 	 * the new array.
2430 	 */
2431 	if (old_array) {
2432 		existing = old_array->items;
2433 		for (; existing->prog; existing++) {
2434 			if (existing->prog == exclude_prog) {
2435 				found_exclude = true;
2436 				continue;
2437 			}
2438 			if (existing->prog != &dummy_bpf_prog.prog)
2439 				carry_prog_cnt++;
2440 			if (existing->prog == include_prog)
2441 				return -EEXIST;
2442 		}
2443 	}
2444 
2445 	if (exclude_prog && !found_exclude)
2446 		return -ENOENT;
2447 
2448 	/* How many progs (not NULL) will be in the new array? */
2449 	new_prog_cnt = carry_prog_cnt;
2450 	if (include_prog)
2451 		new_prog_cnt += 1;
2452 
2453 	/* Do we have any prog (not NULL) in the new array? */
2454 	if (!new_prog_cnt) {
2455 		*new_array = NULL;
2456 		return 0;
2457 	}
2458 
2459 	/* +1 as the end of prog_array is marked with NULL */
2460 	array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2461 	if (!array)
2462 		return -ENOMEM;
2463 	new = array->items;
2464 
2465 	/* Fill in the new prog array */
2466 	if (carry_prog_cnt) {
2467 		existing = old_array->items;
2468 		for (; existing->prog; existing++) {
2469 			if (existing->prog == exclude_prog ||
2470 			    existing->prog == &dummy_bpf_prog.prog)
2471 				continue;
2472 
2473 			new->prog = existing->prog;
2474 			new->bpf_cookie = existing->bpf_cookie;
2475 			new++;
2476 		}
2477 	}
2478 	if (include_prog) {
2479 		new->prog = include_prog;
2480 		new->bpf_cookie = bpf_cookie;
2481 		new++;
2482 	}
2483 	new->prog = NULL;
2484 	*new_array = array;
2485 	return 0;
2486 }
2487 
2488 int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2489 			     u32 *prog_ids, u32 request_cnt,
2490 			     u32 *prog_cnt)
2491 {
2492 	u32 cnt = 0;
2493 
2494 	if (array)
2495 		cnt = bpf_prog_array_length(array);
2496 
2497 	*prog_cnt = cnt;
2498 
2499 	/* return early if user requested only program count or nothing to copy */
2500 	if (!request_cnt || !cnt)
2501 		return 0;
2502 
2503 	/* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2504 	return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2505 								     : 0;
2506 }
2507 
2508 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2509 			  struct bpf_map **used_maps, u32 len)
2510 {
2511 	struct bpf_map *map;
2512 	u32 i;
2513 
2514 	for (i = 0; i < len; i++) {
2515 		map = used_maps[i];
2516 		if (map->ops->map_poke_untrack)
2517 			map->ops->map_poke_untrack(map, aux);
2518 		bpf_map_put(map);
2519 	}
2520 }
2521 
2522 static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2523 {
2524 	__bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2525 	kfree(aux->used_maps);
2526 }
2527 
2528 void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
2529 			  struct btf_mod_pair *used_btfs, u32 len)
2530 {
2531 #ifdef CONFIG_BPF_SYSCALL
2532 	struct btf_mod_pair *btf_mod;
2533 	u32 i;
2534 
2535 	for (i = 0; i < len; i++) {
2536 		btf_mod = &used_btfs[i];
2537 		if (btf_mod->module)
2538 			module_put(btf_mod->module);
2539 		btf_put(btf_mod->btf);
2540 	}
2541 #endif
2542 }
2543 
2544 static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2545 {
2546 	__bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt);
2547 	kfree(aux->used_btfs);
2548 }
2549 
2550 static void bpf_prog_free_deferred(struct work_struct *work)
2551 {
2552 	struct bpf_prog_aux *aux;
2553 	int i;
2554 
2555 	aux = container_of(work, struct bpf_prog_aux, work);
2556 #ifdef CONFIG_BPF_SYSCALL
2557 	bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
2558 #endif
2559 #ifdef CONFIG_CGROUP_BPF
2560 	if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
2561 		bpf_cgroup_atype_put(aux->cgroup_atype);
2562 #endif
2563 	bpf_free_used_maps(aux);
2564 	bpf_free_used_btfs(aux);
2565 	if (bpf_prog_is_dev_bound(aux))
2566 		bpf_prog_dev_bound_destroy(aux->prog);
2567 #ifdef CONFIG_PERF_EVENTS
2568 	if (aux->prog->has_callchain_buf)
2569 		put_callchain_buffers();
2570 #endif
2571 	if (aux->dst_trampoline)
2572 		bpf_trampoline_put(aux->dst_trampoline);
2573 	for (i = 0; i < aux->func_cnt; i++) {
2574 		/* We can just unlink the subprog poke descriptor table as
2575 		 * it was originally linked to the main program and is also
2576 		 * released along with it.
2577 		 */
2578 		aux->func[i]->aux->poke_tab = NULL;
2579 		bpf_jit_free(aux->func[i]);
2580 	}
2581 	if (aux->func_cnt) {
2582 		kfree(aux->func);
2583 		bpf_prog_unlock_free(aux->prog);
2584 	} else {
2585 		bpf_jit_free(aux->prog);
2586 	}
2587 }
2588 
2589 void bpf_prog_free(struct bpf_prog *fp)
2590 {
2591 	struct bpf_prog_aux *aux = fp->aux;
2592 
2593 	if (aux->dst_prog)
2594 		bpf_prog_put(aux->dst_prog);
2595 	INIT_WORK(&aux->work, bpf_prog_free_deferred);
2596 	schedule_work(&aux->work);
2597 }
2598 EXPORT_SYMBOL_GPL(bpf_prog_free);
2599 
2600 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
2601 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2602 
2603 void bpf_user_rnd_init_once(void)
2604 {
2605 	prandom_init_once(&bpf_user_rnd_state);
2606 }
2607 
2608 BPF_CALL_0(bpf_user_rnd_u32)
2609 {
2610 	/* Should someone ever have the rather unwise idea to use some
2611 	 * of the registers passed into this function, then note that
2612 	 * this function is called from native eBPF and classic-to-eBPF
2613 	 * transformations. Register assignments from both sides are
2614 	 * different, f.e. classic always sets fn(ctx, A, X) here.
2615 	 */
2616 	struct rnd_state *state;
2617 	u32 res;
2618 
2619 	state = &get_cpu_var(bpf_user_rnd_state);
2620 	res = prandom_u32_state(state);
2621 	put_cpu_var(bpf_user_rnd_state);
2622 
2623 	return res;
2624 }
2625 
2626 BPF_CALL_0(bpf_get_raw_cpu_id)
2627 {
2628 	return raw_smp_processor_id();
2629 }
2630 
2631 /* Weak definitions of helper functions in case we don't have bpf syscall. */
2632 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2633 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2634 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2635 const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2636 const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2637 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2638 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
2639 const struct bpf_func_proto bpf_spin_lock_proto __weak;
2640 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2641 const struct bpf_func_proto bpf_jiffies64_proto __weak;
2642 
2643 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2644 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2645 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2646 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2647 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2648 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2649 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
2650 
2651 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2652 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2653 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2654 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2655 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2656 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2657 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2658 const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2659 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2660 const struct bpf_func_proto bpf_set_retval_proto __weak;
2661 const struct bpf_func_proto bpf_get_retval_proto __weak;
2662 
2663 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2664 {
2665 	return NULL;
2666 }
2667 
2668 const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
2669 {
2670 	return NULL;
2671 }
2672 
2673 u64 __weak
2674 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2675 		 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2676 {
2677 	return -ENOTSUPP;
2678 }
2679 EXPORT_SYMBOL_GPL(bpf_event_output);
2680 
2681 /* Always built-in helper functions. */
2682 const struct bpf_func_proto bpf_tail_call_proto = {
2683 	.func		= NULL,
2684 	.gpl_only	= false,
2685 	.ret_type	= RET_VOID,
2686 	.arg1_type	= ARG_PTR_TO_CTX,
2687 	.arg2_type	= ARG_CONST_MAP_PTR,
2688 	.arg3_type	= ARG_ANYTHING,
2689 };
2690 
2691 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2692  * It is encouraged to implement bpf_int_jit_compile() instead, so that
2693  * eBPF and implicitly also cBPF can get JITed!
2694  */
2695 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2696 {
2697 	return prog;
2698 }
2699 
2700 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
2701  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2702  */
2703 void __weak bpf_jit_compile(struct bpf_prog *prog)
2704 {
2705 }
2706 
2707 bool __weak bpf_helper_changes_pkt_data(void *func)
2708 {
2709 	return false;
2710 }
2711 
2712 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2713  * analysis code and wants explicit zero extension inserted by verifier.
2714  * Otherwise, return FALSE.
2715  *
2716  * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2717  * you don't override this. JITs that don't want these extra insns can detect
2718  * them using insn_is_zext.
2719  */
2720 bool __weak bpf_jit_needs_zext(void)
2721 {
2722 	return false;
2723 }
2724 
2725 /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
2726 bool __weak bpf_jit_supports_subprog_tailcalls(void)
2727 {
2728 	return false;
2729 }
2730 
2731 bool __weak bpf_jit_supports_kfunc_call(void)
2732 {
2733 	return false;
2734 }
2735 
2736 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
2737  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
2738  */
2739 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
2740 			 int len)
2741 {
2742 	return -EFAULT;
2743 }
2744 
2745 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
2746 			      void *addr1, void *addr2)
2747 {
2748 	return -ENOTSUPP;
2749 }
2750 
2751 void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
2752 {
2753 	return ERR_PTR(-ENOTSUPP);
2754 }
2755 
2756 int __weak bpf_arch_text_invalidate(void *dst, size_t len)
2757 {
2758 	return -ENOTSUPP;
2759 }
2760 
2761 #ifdef CONFIG_BPF_SYSCALL
2762 static int __init bpf_global_ma_init(void)
2763 {
2764 	int ret;
2765 
2766 	ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
2767 	bpf_global_ma_set = !ret;
2768 	return ret;
2769 }
2770 late_initcall(bpf_global_ma_init);
2771 #endif
2772 
2773 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
2774 EXPORT_SYMBOL(bpf_stats_enabled_key);
2775 
2776 /* All definitions of tracepoints related to BPF. */
2777 #define CREATE_TRACE_POINTS
2778 #include <linux/bpf_trace.h>
2779 
2780 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
2781 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);
2782