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  */
bpf_internal_load_pointer_neg_helper(const struct sk_buff * skb,int k,unsigned int size)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 
bpf_prog_alloc_no_stats(unsigned int size,gfp_t gfp_extra_flags)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 
bpf_prog_alloc(unsigned int size,gfp_t gfp_extra_flags)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 
bpf_prog_alloc_jited_linfo(struct bpf_prog * prog)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 
bpf_prog_jit_attempt_done(struct bpf_prog * prog)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  */
bpf_prog_fill_jited_linfo(struct bpf_prog * prog,const u32 * insn_to_jit_off)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 
bpf_prog_realloc(struct bpf_prog * fp_old,unsigned int size,gfp_t gfp_extra_flags)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 
__bpf_prog_free(struct bpf_prog * fp)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 
bpf_prog_calc_tag(struct bpf_prog * fp)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 
bpf_adj_delta_to_imm(struct bpf_insn * insn,u32 pos,s32 end_old,s32 end_new,s32 curr,const bool probe_pass)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 
bpf_adj_delta_to_off(struct bpf_insn * insn,u32 pos,s32 end_old,s32 end_new,s32 curr,const bool probe_pass)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;
377 
378 	if (insn->code == (BPF_JMP32 | BPF_JA))
379 		off = insn->imm;
380 	else
381 		off = insn->off;
382 
383 	if (curr < pos && curr + off + 1 >= end_old)
384 		off += delta;
385 	else if (curr >= end_new && curr + off + 1 < end_new)
386 		off -= delta;
387 	if (off < off_min || off > off_max)
388 		return -ERANGE;
389 	if (!probe_pass) {
390 		if (insn->code == (BPF_JMP32 | BPF_JA))
391 			insn->imm = off;
392 		else
393 			insn->off = off;
394 	}
395 	return 0;
396 }
397 
bpf_adj_branches(struct bpf_prog * prog,u32 pos,s32 end_old,s32 end_new,const bool probe_pass)398 static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
399 			    s32 end_new, const bool probe_pass)
400 {
401 	u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
402 	struct bpf_insn *insn = prog->insnsi;
403 	int ret = 0;
404 
405 	for (i = 0; i < insn_cnt; i++, insn++) {
406 		u8 code;
407 
408 		/* In the probing pass we still operate on the original,
409 		 * unpatched image in order to check overflows before we
410 		 * do any other adjustments. Therefore skip the patchlet.
411 		 */
412 		if (probe_pass && i == pos) {
413 			i = end_new;
414 			insn = prog->insnsi + end_old;
415 		}
416 		if (bpf_pseudo_func(insn)) {
417 			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
418 						   end_new, i, probe_pass);
419 			if (ret)
420 				return ret;
421 			continue;
422 		}
423 		code = insn->code;
424 		if ((BPF_CLASS(code) != BPF_JMP &&
425 		     BPF_CLASS(code) != BPF_JMP32) ||
426 		    BPF_OP(code) == BPF_EXIT)
427 			continue;
428 		/* Adjust offset of jmps if we cross patch boundaries. */
429 		if (BPF_OP(code) == BPF_CALL) {
430 			if (insn->src_reg != BPF_PSEUDO_CALL)
431 				continue;
432 			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
433 						   end_new, i, probe_pass);
434 		} else {
435 			ret = bpf_adj_delta_to_off(insn, pos, end_old,
436 						   end_new, i, probe_pass);
437 		}
438 		if (ret)
439 			break;
440 	}
441 
442 	return ret;
443 }
444 
bpf_adj_linfo(struct bpf_prog * prog,u32 off,u32 delta)445 static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
446 {
447 	struct bpf_line_info *linfo;
448 	u32 i, nr_linfo;
449 
450 	nr_linfo = prog->aux->nr_linfo;
451 	if (!nr_linfo || !delta)
452 		return;
453 
454 	linfo = prog->aux->linfo;
455 
456 	for (i = 0; i < nr_linfo; i++)
457 		if (off < linfo[i].insn_off)
458 			break;
459 
460 	/* Push all off < linfo[i].insn_off by delta */
461 	for (; i < nr_linfo; i++)
462 		linfo[i].insn_off += delta;
463 }
464 
bpf_patch_insn_single(struct bpf_prog * prog,u32 off,const struct bpf_insn * patch,u32 len)465 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
466 				       const struct bpf_insn *patch, u32 len)
467 {
468 	u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
469 	const u32 cnt_max = S16_MAX;
470 	struct bpf_prog *prog_adj;
471 	int err;
472 
473 	/* Since our patchlet doesn't expand the image, we're done. */
474 	if (insn_delta == 0) {
475 		memcpy(prog->insnsi + off, patch, sizeof(*patch));
476 		return prog;
477 	}
478 
479 	insn_adj_cnt = prog->len + insn_delta;
480 
481 	/* Reject anything that would potentially let the insn->off
482 	 * target overflow when we have excessive program expansions.
483 	 * We need to probe here before we do any reallocation where
484 	 * we afterwards may not fail anymore.
485 	 */
486 	if (insn_adj_cnt > cnt_max &&
487 	    (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
488 		return ERR_PTR(err);
489 
490 	/* Several new instructions need to be inserted. Make room
491 	 * for them. Likely, there's no need for a new allocation as
492 	 * last page could have large enough tailroom.
493 	 */
494 	prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
495 				    GFP_USER);
496 	if (!prog_adj)
497 		return ERR_PTR(-ENOMEM);
498 
499 	prog_adj->len = insn_adj_cnt;
500 
501 	/* Patching happens in 3 steps:
502 	 *
503 	 * 1) Move over tail of insnsi from next instruction onwards,
504 	 *    so we can patch the single target insn with one or more
505 	 *    new ones (patching is always from 1 to n insns, n > 0).
506 	 * 2) Inject new instructions at the target location.
507 	 * 3) Adjust branch offsets if necessary.
508 	 */
509 	insn_rest = insn_adj_cnt - off - len;
510 
511 	memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
512 		sizeof(*patch) * insn_rest);
513 	memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
514 
515 	/* We are guaranteed to not fail at this point, otherwise
516 	 * the ship has sailed to reverse to the original state. An
517 	 * overflow cannot happen at this point.
518 	 */
519 	BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
520 
521 	bpf_adj_linfo(prog_adj, off, insn_delta);
522 
523 	return prog_adj;
524 }
525 
bpf_remove_insns(struct bpf_prog * prog,u32 off,u32 cnt)526 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
527 {
528 	/* Branch offsets can't overflow when program is shrinking, no need
529 	 * to call bpf_adj_branches(..., true) here
530 	 */
531 	memmove(prog->insnsi + off, prog->insnsi + off + cnt,
532 		sizeof(struct bpf_insn) * (prog->len - off - cnt));
533 	prog->len -= cnt;
534 
535 	return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
536 }
537 
bpf_prog_kallsyms_del_subprogs(struct bpf_prog * fp)538 static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
539 {
540 	int i;
541 
542 	for (i = 0; i < fp->aux->func_cnt; i++)
543 		bpf_prog_kallsyms_del(fp->aux->func[i]);
544 }
545 
bpf_prog_kallsyms_del_all(struct bpf_prog * fp)546 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
547 {
548 	bpf_prog_kallsyms_del_subprogs(fp);
549 	bpf_prog_kallsyms_del(fp);
550 }
551 
552 #ifdef CONFIG_BPF_JIT
553 /* All BPF JIT sysctl knobs here. */
554 int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
555 int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
556 int bpf_jit_harden   __read_mostly;
557 long bpf_jit_limit   __read_mostly;
558 long bpf_jit_limit_max __read_mostly;
559 
560 static void
bpf_prog_ksym_set_addr(struct bpf_prog * prog)561 bpf_prog_ksym_set_addr(struct bpf_prog *prog)
562 {
563 	WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
564 
565 	prog->aux->ksym.start = (unsigned long) prog->bpf_func;
566 	prog->aux->ksym.end   = prog->aux->ksym.start + prog->jited_len;
567 }
568 
569 static void
bpf_prog_ksym_set_name(struct bpf_prog * prog)570 bpf_prog_ksym_set_name(struct bpf_prog *prog)
571 {
572 	char *sym = prog->aux->ksym.name;
573 	const char *end = sym + KSYM_NAME_LEN;
574 	const struct btf_type *type;
575 	const char *func_name;
576 
577 	BUILD_BUG_ON(sizeof("bpf_prog_") +
578 		     sizeof(prog->tag) * 2 +
579 		     /* name has been null terminated.
580 		      * We should need +1 for the '_' preceding
581 		      * the name.  However, the null character
582 		      * is double counted between the name and the
583 		      * sizeof("bpf_prog_") above, so we omit
584 		      * the +1 here.
585 		      */
586 		     sizeof(prog->aux->name) > KSYM_NAME_LEN);
587 
588 	sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
589 	sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
590 
591 	/* prog->aux->name will be ignored if full btf name is available */
592 	if (prog->aux->func_info_cnt) {
593 		type = btf_type_by_id(prog->aux->btf,
594 				      prog->aux->func_info[prog->aux->func_idx].type_id);
595 		func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
596 		snprintf(sym, (size_t)(end - sym), "_%s", func_name);
597 		return;
598 	}
599 
600 	if (prog->aux->name[0])
601 		snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
602 	else
603 		*sym = 0;
604 }
605 
bpf_get_ksym_start(struct latch_tree_node * n)606 static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
607 {
608 	return container_of(n, struct bpf_ksym, tnode)->start;
609 }
610 
bpf_tree_less(struct latch_tree_node * a,struct latch_tree_node * b)611 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
612 					  struct latch_tree_node *b)
613 {
614 	return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
615 }
616 
bpf_tree_comp(void * key,struct latch_tree_node * n)617 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
618 {
619 	unsigned long val = (unsigned long)key;
620 	const struct bpf_ksym *ksym;
621 
622 	ksym = container_of(n, struct bpf_ksym, tnode);
623 
624 	if (val < ksym->start)
625 		return -1;
626 	if (val >= ksym->end)
627 		return  1;
628 
629 	return 0;
630 }
631 
632 static const struct latch_tree_ops bpf_tree_ops = {
633 	.less	= bpf_tree_less,
634 	.comp	= bpf_tree_comp,
635 };
636 
637 static DEFINE_SPINLOCK(bpf_lock);
638 static LIST_HEAD(bpf_kallsyms);
639 static struct latch_tree_root bpf_tree __cacheline_aligned;
640 
bpf_ksym_add(struct bpf_ksym * ksym)641 void bpf_ksym_add(struct bpf_ksym *ksym)
642 {
643 	spin_lock_bh(&bpf_lock);
644 	WARN_ON_ONCE(!list_empty(&ksym->lnode));
645 	list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
646 	latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
647 	spin_unlock_bh(&bpf_lock);
648 }
649 
__bpf_ksym_del(struct bpf_ksym * ksym)650 static void __bpf_ksym_del(struct bpf_ksym *ksym)
651 {
652 	if (list_empty(&ksym->lnode))
653 		return;
654 
655 	latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
656 	list_del_rcu(&ksym->lnode);
657 }
658 
bpf_ksym_del(struct bpf_ksym * ksym)659 void bpf_ksym_del(struct bpf_ksym *ksym)
660 {
661 	spin_lock_bh(&bpf_lock);
662 	__bpf_ksym_del(ksym);
663 	spin_unlock_bh(&bpf_lock);
664 }
665 
bpf_prog_kallsyms_candidate(const struct bpf_prog * fp)666 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
667 {
668 	return fp->jited && !bpf_prog_was_classic(fp);
669 }
670 
bpf_prog_kallsyms_add(struct bpf_prog * fp)671 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
672 {
673 	if (!bpf_prog_kallsyms_candidate(fp) ||
674 	    !bpf_capable())
675 		return;
676 
677 	bpf_prog_ksym_set_addr(fp);
678 	bpf_prog_ksym_set_name(fp);
679 	fp->aux->ksym.prog = true;
680 
681 	bpf_ksym_add(&fp->aux->ksym);
682 }
683 
bpf_prog_kallsyms_del(struct bpf_prog * fp)684 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
685 {
686 	if (!bpf_prog_kallsyms_candidate(fp))
687 		return;
688 
689 	bpf_ksym_del(&fp->aux->ksym);
690 }
691 
bpf_ksym_find(unsigned long addr)692 static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
693 {
694 	struct latch_tree_node *n;
695 
696 	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
697 	return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
698 }
699 
__bpf_address_lookup(unsigned long addr,unsigned long * size,unsigned long * off,char * sym)700 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
701 				 unsigned long *off, char *sym)
702 {
703 	struct bpf_ksym *ksym;
704 	char *ret = NULL;
705 
706 	rcu_read_lock();
707 	ksym = bpf_ksym_find(addr);
708 	if (ksym) {
709 		unsigned long symbol_start = ksym->start;
710 		unsigned long symbol_end = ksym->end;
711 
712 		strncpy(sym, ksym->name, KSYM_NAME_LEN);
713 
714 		ret = sym;
715 		if (size)
716 			*size = symbol_end - symbol_start;
717 		if (off)
718 			*off  = addr - symbol_start;
719 	}
720 	rcu_read_unlock();
721 
722 	return ret;
723 }
724 
is_bpf_text_address(unsigned long addr)725 bool is_bpf_text_address(unsigned long addr)
726 {
727 	bool ret;
728 
729 	rcu_read_lock();
730 	ret = bpf_ksym_find(addr) != NULL;
731 	rcu_read_unlock();
732 
733 	return ret;
734 }
735 
bpf_prog_ksym_find(unsigned long addr)736 static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
737 {
738 	struct bpf_ksym *ksym = bpf_ksym_find(addr);
739 
740 	return ksym && ksym->prog ?
741 	       container_of(ksym, struct bpf_prog_aux, ksym)->prog :
742 	       NULL;
743 }
744 
search_bpf_extables(unsigned long addr)745 const struct exception_table_entry *search_bpf_extables(unsigned long addr)
746 {
747 	const struct exception_table_entry *e = NULL;
748 	struct bpf_prog *prog;
749 
750 	rcu_read_lock();
751 	prog = bpf_prog_ksym_find(addr);
752 	if (!prog)
753 		goto out;
754 	if (!prog->aux->num_exentries)
755 		goto out;
756 
757 	e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
758 out:
759 	rcu_read_unlock();
760 	return e;
761 }
762 
bpf_get_kallsym(unsigned int symnum,unsigned long * value,char * type,char * sym)763 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
764 		    char *sym)
765 {
766 	struct bpf_ksym *ksym;
767 	unsigned int it = 0;
768 	int ret = -ERANGE;
769 
770 	if (!bpf_jit_kallsyms_enabled())
771 		return ret;
772 
773 	rcu_read_lock();
774 	list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
775 		if (it++ != symnum)
776 			continue;
777 
778 		strncpy(sym, ksym->name, KSYM_NAME_LEN);
779 
780 		*value = ksym->start;
781 		*type  = BPF_SYM_ELF_TYPE;
782 
783 		ret = 0;
784 		break;
785 	}
786 	rcu_read_unlock();
787 
788 	return ret;
789 }
790 
bpf_jit_add_poke_descriptor(struct bpf_prog * prog,struct bpf_jit_poke_descriptor * poke)791 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
792 				struct bpf_jit_poke_descriptor *poke)
793 {
794 	struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
795 	static const u32 poke_tab_max = 1024;
796 	u32 slot = prog->aux->size_poke_tab;
797 	u32 size = slot + 1;
798 
799 	if (size > poke_tab_max)
800 		return -ENOSPC;
801 	if (poke->tailcall_target || poke->tailcall_target_stable ||
802 	    poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
803 		return -EINVAL;
804 
805 	switch (poke->reason) {
806 	case BPF_POKE_REASON_TAIL_CALL:
807 		if (!poke->tail_call.map)
808 			return -EINVAL;
809 		break;
810 	default:
811 		return -EINVAL;
812 	}
813 
814 	tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
815 	if (!tab)
816 		return -ENOMEM;
817 
818 	memcpy(&tab[slot], poke, sizeof(*poke));
819 	prog->aux->size_poke_tab = size;
820 	prog->aux->poke_tab = tab;
821 
822 	return slot;
823 }
824 
825 /*
826  * BPF program pack allocator.
827  *
828  * Most BPF programs are pretty small. Allocating a hole page for each
829  * program is sometime a waste. Many small bpf program also adds pressure
830  * to instruction TLB. To solve this issue, we introduce a BPF program pack
831  * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
832  * to host BPF programs.
833  */
834 #define BPF_PROG_CHUNK_SHIFT	6
835 #define BPF_PROG_CHUNK_SIZE	(1 << BPF_PROG_CHUNK_SHIFT)
836 #define BPF_PROG_CHUNK_MASK	(~(BPF_PROG_CHUNK_SIZE - 1))
837 
838 struct bpf_prog_pack {
839 	struct list_head list;
840 	void *ptr;
841 	unsigned long bitmap[];
842 };
843 
bpf_jit_fill_hole_with_zero(void * area,unsigned int size)844 void bpf_jit_fill_hole_with_zero(void *area, unsigned int size)
845 {
846 	memset(area, 0, size);
847 }
848 
849 #define BPF_PROG_SIZE_TO_NBITS(size)	(round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
850 
851 static DEFINE_MUTEX(pack_mutex);
852 static LIST_HEAD(pack_list);
853 
854 /* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
855  * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
856  */
857 #ifdef PMD_SIZE
858 #define BPF_PROG_PACK_SIZE (PMD_SIZE * num_possible_nodes())
859 #else
860 #define BPF_PROG_PACK_SIZE PAGE_SIZE
861 #endif
862 
863 #define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
864 
alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)865 static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
866 {
867 	struct bpf_prog_pack *pack;
868 
869 	pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)),
870 		       GFP_KERNEL);
871 	if (!pack)
872 		return NULL;
873 	pack->ptr = bpf_jit_alloc_exec(BPF_PROG_PACK_SIZE);
874 	if (!pack->ptr) {
875 		kfree(pack);
876 		return NULL;
877 	}
878 	bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
879 	bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
880 	list_add_tail(&pack->list, &pack_list);
881 
882 	set_vm_flush_reset_perms(pack->ptr);
883 	set_memory_rox((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE);
884 	return pack;
885 }
886 
bpf_prog_pack_alloc(u32 size,bpf_jit_fill_hole_t bpf_fill_ill_insns)887 void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
888 {
889 	unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
890 	struct bpf_prog_pack *pack;
891 	unsigned long pos;
892 	void *ptr = NULL;
893 
894 	mutex_lock(&pack_mutex);
895 	if (size > BPF_PROG_PACK_SIZE) {
896 		size = round_up(size, PAGE_SIZE);
897 		ptr = bpf_jit_alloc_exec(size);
898 		if (ptr) {
899 			bpf_fill_ill_insns(ptr, size);
900 			set_vm_flush_reset_perms(ptr);
901 			set_memory_rox((unsigned long)ptr, size / PAGE_SIZE);
902 		}
903 		goto out;
904 	}
905 	list_for_each_entry(pack, &pack_list, list) {
906 		pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
907 						 nbits, 0);
908 		if (pos < BPF_PROG_CHUNK_COUNT)
909 			goto found_free_area;
910 	}
911 
912 	pack = alloc_new_pack(bpf_fill_ill_insns);
913 	if (!pack)
914 		goto out;
915 
916 	pos = 0;
917 
918 found_free_area:
919 	bitmap_set(pack->bitmap, pos, nbits);
920 	ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
921 
922 out:
923 	mutex_unlock(&pack_mutex);
924 	return ptr;
925 }
926 
bpf_prog_pack_free(struct bpf_binary_header * hdr)927 void bpf_prog_pack_free(struct bpf_binary_header *hdr)
928 {
929 	struct bpf_prog_pack *pack = NULL, *tmp;
930 	unsigned int nbits;
931 	unsigned long pos;
932 
933 	mutex_lock(&pack_mutex);
934 	if (hdr->size > BPF_PROG_PACK_SIZE) {
935 		bpf_jit_free_exec(hdr);
936 		goto out;
937 	}
938 
939 	list_for_each_entry(tmp, &pack_list, list) {
940 		if ((void *)hdr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > (void *)hdr) {
941 			pack = tmp;
942 			break;
943 		}
944 	}
945 
946 	if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
947 		goto out;
948 
949 	nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size);
950 	pos = ((unsigned long)hdr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
951 
952 	WARN_ONCE(bpf_arch_text_invalidate(hdr, hdr->size),
953 		  "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
954 
955 	bitmap_clear(pack->bitmap, pos, nbits);
956 	if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
957 				       BPF_PROG_CHUNK_COUNT, 0) == 0) {
958 		list_del(&pack->list);
959 		bpf_jit_free_exec(pack->ptr);
960 		kfree(pack);
961 	}
962 out:
963 	mutex_unlock(&pack_mutex);
964 }
965 
966 static atomic_long_t bpf_jit_current;
967 
968 /* Can be overridden by an arch's JIT compiler if it has a custom,
969  * dedicated BPF backend memory area, or if neither of the two
970  * below apply.
971  */
bpf_jit_alloc_exec_limit(void)972 u64 __weak bpf_jit_alloc_exec_limit(void)
973 {
974 #if defined(MODULES_VADDR)
975 	return MODULES_END - MODULES_VADDR;
976 #else
977 	return VMALLOC_END - VMALLOC_START;
978 #endif
979 }
980 
bpf_jit_charge_init(void)981 static int __init bpf_jit_charge_init(void)
982 {
983 	/* Only used as heuristic here to derive limit. */
984 	bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
985 	bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 1,
986 					    PAGE_SIZE), LONG_MAX);
987 	return 0;
988 }
989 pure_initcall(bpf_jit_charge_init);
990 
bpf_jit_charge_modmem(u32 size)991 int bpf_jit_charge_modmem(u32 size)
992 {
993 	if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
994 		if (!bpf_capable()) {
995 			atomic_long_sub(size, &bpf_jit_current);
996 			return -EPERM;
997 		}
998 	}
999 
1000 	return 0;
1001 }
1002 
bpf_jit_uncharge_modmem(u32 size)1003 void bpf_jit_uncharge_modmem(u32 size)
1004 {
1005 	atomic_long_sub(size, &bpf_jit_current);
1006 }
1007 
bpf_jit_alloc_exec(unsigned long size)1008 void *__weak bpf_jit_alloc_exec(unsigned long size)
1009 {
1010 	return module_alloc(size);
1011 }
1012 
bpf_jit_free_exec(void * addr)1013 void __weak bpf_jit_free_exec(void *addr)
1014 {
1015 	module_memfree(addr);
1016 }
1017 
1018 struct bpf_binary_header *
bpf_jit_binary_alloc(unsigned int proglen,u8 ** image_ptr,unsigned int alignment,bpf_jit_fill_hole_t bpf_fill_ill_insns)1019 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1020 		     unsigned int alignment,
1021 		     bpf_jit_fill_hole_t bpf_fill_ill_insns)
1022 {
1023 	struct bpf_binary_header *hdr;
1024 	u32 size, hole, start;
1025 
1026 	WARN_ON_ONCE(!is_power_of_2(alignment) ||
1027 		     alignment > BPF_IMAGE_ALIGNMENT);
1028 
1029 	/* Most of BPF filters are really small, but if some of them
1030 	 * fill a page, allow at least 128 extra bytes to insert a
1031 	 * random section of illegal instructions.
1032 	 */
1033 	size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
1034 
1035 	if (bpf_jit_charge_modmem(size))
1036 		return NULL;
1037 	hdr = bpf_jit_alloc_exec(size);
1038 	if (!hdr) {
1039 		bpf_jit_uncharge_modmem(size);
1040 		return NULL;
1041 	}
1042 
1043 	/* Fill space with illegal/arch-dep instructions. */
1044 	bpf_fill_ill_insns(hdr, size);
1045 
1046 	hdr->size = size;
1047 	hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
1048 		     PAGE_SIZE - sizeof(*hdr));
1049 	start = get_random_u32_below(hole) & ~(alignment - 1);
1050 
1051 	/* Leave a random number of instructions before BPF code. */
1052 	*image_ptr = &hdr->image[start];
1053 
1054 	return hdr;
1055 }
1056 
bpf_jit_binary_free(struct bpf_binary_header * hdr)1057 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
1058 {
1059 	u32 size = hdr->size;
1060 
1061 	bpf_jit_free_exec(hdr);
1062 	bpf_jit_uncharge_modmem(size);
1063 }
1064 
1065 /* Allocate jit binary from bpf_prog_pack allocator.
1066  * Since the allocated memory is RO+X, the JIT engine cannot write directly
1067  * to the memory. To solve this problem, a RW buffer is also allocated at
1068  * as the same time. The JIT engine should calculate offsets based on the
1069  * RO memory address, but write JITed program to the RW buffer. Once the
1070  * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
1071  * the JITed program to the RO memory.
1072  */
1073 struct bpf_binary_header *
bpf_jit_binary_pack_alloc(unsigned int proglen,u8 ** image_ptr,unsigned int alignment,struct bpf_binary_header ** rw_header,u8 ** rw_image,bpf_jit_fill_hole_t bpf_fill_ill_insns)1074 bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
1075 			  unsigned int alignment,
1076 			  struct bpf_binary_header **rw_header,
1077 			  u8 **rw_image,
1078 			  bpf_jit_fill_hole_t bpf_fill_ill_insns)
1079 {
1080 	struct bpf_binary_header *ro_header;
1081 	u32 size, hole, start;
1082 
1083 	WARN_ON_ONCE(!is_power_of_2(alignment) ||
1084 		     alignment > BPF_IMAGE_ALIGNMENT);
1085 
1086 	/* add 16 bytes for a random section of illegal instructions */
1087 	size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
1088 
1089 	if (bpf_jit_charge_modmem(size))
1090 		return NULL;
1091 	ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns);
1092 	if (!ro_header) {
1093 		bpf_jit_uncharge_modmem(size);
1094 		return NULL;
1095 	}
1096 
1097 	*rw_header = kvmalloc(size, GFP_KERNEL);
1098 	if (!*rw_header) {
1099 		bpf_arch_text_copy(&ro_header->size, &size, sizeof(size));
1100 		bpf_prog_pack_free(ro_header);
1101 		bpf_jit_uncharge_modmem(size);
1102 		return NULL;
1103 	}
1104 
1105 	/* Fill space with illegal/arch-dep instructions. */
1106 	bpf_fill_ill_insns(*rw_header, size);
1107 	(*rw_header)->size = size;
1108 
1109 	hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
1110 		     BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
1111 	start = get_random_u32_below(hole) & ~(alignment - 1);
1112 
1113 	*image_ptr = &ro_header->image[start];
1114 	*rw_image = &(*rw_header)->image[start];
1115 
1116 	return ro_header;
1117 }
1118 
1119 /* Copy JITed text from rw_header to its final location, the ro_header. */
bpf_jit_binary_pack_finalize(struct bpf_prog * prog,struct bpf_binary_header * ro_header,struct bpf_binary_header * rw_header)1120 int bpf_jit_binary_pack_finalize(struct bpf_prog *prog,
1121 				 struct bpf_binary_header *ro_header,
1122 				 struct bpf_binary_header *rw_header)
1123 {
1124 	void *ptr;
1125 
1126 	ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
1127 
1128 	kvfree(rw_header);
1129 
1130 	if (IS_ERR(ptr)) {
1131 		bpf_prog_pack_free(ro_header);
1132 		return PTR_ERR(ptr);
1133 	}
1134 	return 0;
1135 }
1136 
1137 /* bpf_jit_binary_pack_free is called in two different scenarios:
1138  *   1) when the program is freed after;
1139  *   2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
1140  * For case 2), we need to free both the RO memory and the RW buffer.
1141  *
1142  * bpf_jit_binary_pack_free requires proper ro_header->size. However,
1143  * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
1144  * must be set with either bpf_jit_binary_pack_finalize (normal path) or
1145  * bpf_arch_text_copy (when jit fails).
1146  */
bpf_jit_binary_pack_free(struct bpf_binary_header * ro_header,struct bpf_binary_header * rw_header)1147 void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
1148 			      struct bpf_binary_header *rw_header)
1149 {
1150 	u32 size = ro_header->size;
1151 
1152 	bpf_prog_pack_free(ro_header);
1153 	kvfree(rw_header);
1154 	bpf_jit_uncharge_modmem(size);
1155 }
1156 
1157 struct bpf_binary_header *
bpf_jit_binary_pack_hdr(const struct bpf_prog * fp)1158 bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
1159 {
1160 	unsigned long real_start = (unsigned long)fp->bpf_func;
1161 	unsigned long addr;
1162 
1163 	addr = real_start & BPF_PROG_CHUNK_MASK;
1164 	return (void *)addr;
1165 }
1166 
1167 static inline struct bpf_binary_header *
bpf_jit_binary_hdr(const struct bpf_prog * fp)1168 bpf_jit_binary_hdr(const struct bpf_prog *fp)
1169 {
1170 	unsigned long real_start = (unsigned long)fp->bpf_func;
1171 	unsigned long addr;
1172 
1173 	addr = real_start & PAGE_MASK;
1174 	return (void *)addr;
1175 }
1176 
1177 /* This symbol is only overridden by archs that have different
1178  * requirements than the usual eBPF JITs, f.e. when they only
1179  * implement cBPF JIT, do not set images read-only, etc.
1180  */
bpf_jit_free(struct bpf_prog * fp)1181 void __weak bpf_jit_free(struct bpf_prog *fp)
1182 {
1183 	if (fp->jited) {
1184 		struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
1185 
1186 		bpf_jit_binary_free(hdr);
1187 		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
1188 	}
1189 
1190 	bpf_prog_unlock_free(fp);
1191 }
1192 
bpf_jit_get_func_addr(const struct bpf_prog * prog,const struct bpf_insn * insn,bool extra_pass,u64 * func_addr,bool * func_addr_fixed)1193 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1194 			  const struct bpf_insn *insn, bool extra_pass,
1195 			  u64 *func_addr, bool *func_addr_fixed)
1196 {
1197 	s16 off = insn->off;
1198 	s32 imm = insn->imm;
1199 	u8 *addr;
1200 	int err;
1201 
1202 	*func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1203 	if (!*func_addr_fixed) {
1204 		/* Place-holder address till the last pass has collected
1205 		 * all addresses for JITed subprograms in which case we
1206 		 * can pick them up from prog->aux.
1207 		 */
1208 		if (!extra_pass)
1209 			addr = NULL;
1210 		else if (prog->aux->func &&
1211 			 off >= 0 && off < prog->aux->func_cnt)
1212 			addr = (u8 *)prog->aux->func[off]->bpf_func;
1213 		else
1214 			return -EINVAL;
1215 	} else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL &&
1216 		   bpf_jit_supports_far_kfunc_call()) {
1217 		err = bpf_get_kfunc_addr(prog, insn->imm, insn->off, &addr);
1218 		if (err)
1219 			return err;
1220 	} else {
1221 		/* Address of a BPF helper call. Since part of the core
1222 		 * kernel, it's always at a fixed location. __bpf_call_base
1223 		 * and the helper with imm relative to it are both in core
1224 		 * kernel.
1225 		 */
1226 		addr = (u8 *)__bpf_call_base + imm;
1227 	}
1228 
1229 	*func_addr = (unsigned long)addr;
1230 	return 0;
1231 }
1232 
bpf_jit_blind_insn(const struct bpf_insn * from,const struct bpf_insn * aux,struct bpf_insn * to_buff,bool emit_zext)1233 static int bpf_jit_blind_insn(const struct bpf_insn *from,
1234 			      const struct bpf_insn *aux,
1235 			      struct bpf_insn *to_buff,
1236 			      bool emit_zext)
1237 {
1238 	struct bpf_insn *to = to_buff;
1239 	u32 imm_rnd = get_random_u32();
1240 	s16 off;
1241 
1242 	BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
1243 	BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
1244 
1245 	/* Constraints on AX register:
1246 	 *
1247 	 * AX register is inaccessible from user space. It is mapped in
1248 	 * all JITs, and used here for constant blinding rewrites. It is
1249 	 * typically "stateless" meaning its contents are only valid within
1250 	 * the executed instruction, but not across several instructions.
1251 	 * There are a few exceptions however which are further detailed
1252 	 * below.
1253 	 *
1254 	 * Constant blinding is only used by JITs, not in the interpreter.
1255 	 * The interpreter uses AX in some occasions as a local temporary
1256 	 * register e.g. in DIV or MOD instructions.
1257 	 *
1258 	 * In restricted circumstances, the verifier can also use the AX
1259 	 * register for rewrites as long as they do not interfere with
1260 	 * the above cases!
1261 	 */
1262 	if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1263 		goto out;
1264 
1265 	if (from->imm == 0 &&
1266 	    (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
1267 	     from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1268 		*to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1269 		goto out;
1270 	}
1271 
1272 	switch (from->code) {
1273 	case BPF_ALU | BPF_ADD | BPF_K:
1274 	case BPF_ALU | BPF_SUB | BPF_K:
1275 	case BPF_ALU | BPF_AND | BPF_K:
1276 	case BPF_ALU | BPF_OR  | BPF_K:
1277 	case BPF_ALU | BPF_XOR | BPF_K:
1278 	case BPF_ALU | BPF_MUL | BPF_K:
1279 	case BPF_ALU | BPF_MOV | BPF_K:
1280 	case BPF_ALU | BPF_DIV | BPF_K:
1281 	case BPF_ALU | BPF_MOD | BPF_K:
1282 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1283 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1284 		*to++ = BPF_ALU32_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1285 		break;
1286 
1287 	case BPF_ALU64 | BPF_ADD | BPF_K:
1288 	case BPF_ALU64 | BPF_SUB | BPF_K:
1289 	case BPF_ALU64 | BPF_AND | BPF_K:
1290 	case BPF_ALU64 | BPF_OR  | BPF_K:
1291 	case BPF_ALU64 | BPF_XOR | BPF_K:
1292 	case BPF_ALU64 | BPF_MUL | BPF_K:
1293 	case BPF_ALU64 | BPF_MOV | BPF_K:
1294 	case BPF_ALU64 | BPF_DIV | BPF_K:
1295 	case BPF_ALU64 | BPF_MOD | BPF_K:
1296 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1297 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1298 		*to++ = BPF_ALU64_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1299 		break;
1300 
1301 	case BPF_JMP | BPF_JEQ  | BPF_K:
1302 	case BPF_JMP | BPF_JNE  | BPF_K:
1303 	case BPF_JMP | BPF_JGT  | BPF_K:
1304 	case BPF_JMP | BPF_JLT  | BPF_K:
1305 	case BPF_JMP | BPF_JGE  | BPF_K:
1306 	case BPF_JMP | BPF_JLE  | BPF_K:
1307 	case BPF_JMP | BPF_JSGT | BPF_K:
1308 	case BPF_JMP | BPF_JSLT | BPF_K:
1309 	case BPF_JMP | BPF_JSGE | BPF_K:
1310 	case BPF_JMP | BPF_JSLE | BPF_K:
1311 	case BPF_JMP | BPF_JSET | BPF_K:
1312 		/* Accommodate for extra offset in case of a backjump. */
1313 		off = from->off;
1314 		if (off < 0)
1315 			off -= 2;
1316 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1317 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1318 		*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1319 		break;
1320 
1321 	case BPF_JMP32 | BPF_JEQ  | BPF_K:
1322 	case BPF_JMP32 | BPF_JNE  | BPF_K:
1323 	case BPF_JMP32 | BPF_JGT  | BPF_K:
1324 	case BPF_JMP32 | BPF_JLT  | BPF_K:
1325 	case BPF_JMP32 | BPF_JGE  | BPF_K:
1326 	case BPF_JMP32 | BPF_JLE  | BPF_K:
1327 	case BPF_JMP32 | BPF_JSGT | BPF_K:
1328 	case BPF_JMP32 | BPF_JSLT | BPF_K:
1329 	case BPF_JMP32 | BPF_JSGE | BPF_K:
1330 	case BPF_JMP32 | BPF_JSLE | BPF_K:
1331 	case BPF_JMP32 | BPF_JSET | BPF_K:
1332 		/* Accommodate for extra offset in case of a backjump. */
1333 		off = from->off;
1334 		if (off < 0)
1335 			off -= 2;
1336 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1337 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1338 		*to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1339 				      off);
1340 		break;
1341 
1342 	case BPF_LD | BPF_IMM | BPF_DW:
1343 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1344 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1345 		*to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1346 		*to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1347 		break;
1348 	case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1349 		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1350 		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1351 		if (emit_zext)
1352 			*to++ = BPF_ZEXT_REG(BPF_REG_AX);
1353 		*to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
1354 		break;
1355 
1356 	case BPF_ST | BPF_MEM | BPF_DW:
1357 	case BPF_ST | BPF_MEM | BPF_W:
1358 	case BPF_ST | BPF_MEM | BPF_H:
1359 	case BPF_ST | BPF_MEM | BPF_B:
1360 		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1361 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1362 		*to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1363 		break;
1364 	}
1365 out:
1366 	return to - to_buff;
1367 }
1368 
bpf_prog_clone_create(struct bpf_prog * fp_other,gfp_t gfp_extra_flags)1369 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1370 					      gfp_t gfp_extra_flags)
1371 {
1372 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1373 	struct bpf_prog *fp;
1374 
1375 	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1376 	if (fp != NULL) {
1377 		/* aux->prog still points to the fp_other one, so
1378 		 * when promoting the clone to the real program,
1379 		 * this still needs to be adapted.
1380 		 */
1381 		memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1382 	}
1383 
1384 	return fp;
1385 }
1386 
bpf_prog_clone_free(struct bpf_prog * fp)1387 static void bpf_prog_clone_free(struct bpf_prog *fp)
1388 {
1389 	/* aux was stolen by the other clone, so we cannot free
1390 	 * it from this path! It will be freed eventually by the
1391 	 * other program on release.
1392 	 *
1393 	 * At this point, we don't need a deferred release since
1394 	 * clone is guaranteed to not be locked.
1395 	 */
1396 	fp->aux = NULL;
1397 	fp->stats = NULL;
1398 	fp->active = NULL;
1399 	__bpf_prog_free(fp);
1400 }
1401 
bpf_jit_prog_release_other(struct bpf_prog * fp,struct bpf_prog * fp_other)1402 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1403 {
1404 	/* We have to repoint aux->prog to self, as we don't
1405 	 * know whether fp here is the clone or the original.
1406 	 */
1407 	fp->aux->prog = fp;
1408 	bpf_prog_clone_free(fp_other);
1409 }
1410 
bpf_jit_blind_constants(struct bpf_prog * prog)1411 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1412 {
1413 	struct bpf_insn insn_buff[16], aux[2];
1414 	struct bpf_prog *clone, *tmp;
1415 	int insn_delta, insn_cnt;
1416 	struct bpf_insn *insn;
1417 	int i, rewritten;
1418 
1419 	if (!prog->blinding_requested || prog->blinded)
1420 		return prog;
1421 
1422 	clone = bpf_prog_clone_create(prog, GFP_USER);
1423 	if (!clone)
1424 		return ERR_PTR(-ENOMEM);
1425 
1426 	insn_cnt = clone->len;
1427 	insn = clone->insnsi;
1428 
1429 	for (i = 0; i < insn_cnt; i++, insn++) {
1430 		if (bpf_pseudo_func(insn)) {
1431 			/* ld_imm64 with an address of bpf subprog is not
1432 			 * a user controlled constant. Don't randomize it,
1433 			 * since it will conflict with jit_subprogs() logic.
1434 			 */
1435 			insn++;
1436 			i++;
1437 			continue;
1438 		}
1439 
1440 		/* We temporarily need to hold the original ld64 insn
1441 		 * so that we can still access the first part in the
1442 		 * second blinding run.
1443 		 */
1444 		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1445 		    insn[1].code == 0)
1446 			memcpy(aux, insn, sizeof(aux));
1447 
1448 		rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1449 						clone->aux->verifier_zext);
1450 		if (!rewritten)
1451 			continue;
1452 
1453 		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1454 		if (IS_ERR(tmp)) {
1455 			/* Patching may have repointed aux->prog during
1456 			 * realloc from the original one, so we need to
1457 			 * fix it up here on error.
1458 			 */
1459 			bpf_jit_prog_release_other(prog, clone);
1460 			return tmp;
1461 		}
1462 
1463 		clone = tmp;
1464 		insn_delta = rewritten - 1;
1465 
1466 		/* Walk new program and skip insns we just inserted. */
1467 		insn = clone->insnsi + i + insn_delta;
1468 		insn_cnt += insn_delta;
1469 		i        += insn_delta;
1470 	}
1471 
1472 	clone->blinded = 1;
1473 	return clone;
1474 }
1475 #endif /* CONFIG_BPF_JIT */
1476 
1477 /* Base function for offset calculation. Needs to go into .text section,
1478  * therefore keeping it non-static as well; will also be used by JITs
1479  * anyway later on, so do not let the compiler omit it. This also needs
1480  * to go into kallsyms for correlation from e.g. bpftool, so naming
1481  * must not change.
1482  */
__bpf_call_base(u64 r1,u64 r2,u64 r3,u64 r4,u64 r5)1483 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1484 {
1485 	return 0;
1486 }
1487 EXPORT_SYMBOL_GPL(__bpf_call_base);
1488 
1489 /* All UAPI available opcodes. */
1490 #define BPF_INSN_MAP(INSN_2, INSN_3)		\
1491 	/* 32 bit ALU operations. */		\
1492 	/*   Register based. */			\
1493 	INSN_3(ALU, ADD,  X),			\
1494 	INSN_3(ALU, SUB,  X),			\
1495 	INSN_3(ALU, AND,  X),			\
1496 	INSN_3(ALU, OR,   X),			\
1497 	INSN_3(ALU, LSH,  X),			\
1498 	INSN_3(ALU, RSH,  X),			\
1499 	INSN_3(ALU, XOR,  X),			\
1500 	INSN_3(ALU, MUL,  X),			\
1501 	INSN_3(ALU, MOV,  X),			\
1502 	INSN_3(ALU, ARSH, X),			\
1503 	INSN_3(ALU, DIV,  X),			\
1504 	INSN_3(ALU, MOD,  X),			\
1505 	INSN_2(ALU, NEG),			\
1506 	INSN_3(ALU, END, TO_BE),		\
1507 	INSN_3(ALU, END, TO_LE),		\
1508 	/*   Immediate based. */		\
1509 	INSN_3(ALU, ADD,  K),			\
1510 	INSN_3(ALU, SUB,  K),			\
1511 	INSN_3(ALU, AND,  K),			\
1512 	INSN_3(ALU, OR,   K),			\
1513 	INSN_3(ALU, LSH,  K),			\
1514 	INSN_3(ALU, RSH,  K),			\
1515 	INSN_3(ALU, XOR,  K),			\
1516 	INSN_3(ALU, MUL,  K),			\
1517 	INSN_3(ALU, MOV,  K),			\
1518 	INSN_3(ALU, ARSH, K),			\
1519 	INSN_3(ALU, DIV,  K),			\
1520 	INSN_3(ALU, MOD,  K),			\
1521 	/* 64 bit ALU operations. */		\
1522 	/*   Register based. */			\
1523 	INSN_3(ALU64, ADD,  X),			\
1524 	INSN_3(ALU64, SUB,  X),			\
1525 	INSN_3(ALU64, AND,  X),			\
1526 	INSN_3(ALU64, OR,   X),			\
1527 	INSN_3(ALU64, LSH,  X),			\
1528 	INSN_3(ALU64, RSH,  X),			\
1529 	INSN_3(ALU64, XOR,  X),			\
1530 	INSN_3(ALU64, MUL,  X),			\
1531 	INSN_3(ALU64, MOV,  X),			\
1532 	INSN_3(ALU64, ARSH, X),			\
1533 	INSN_3(ALU64, DIV,  X),			\
1534 	INSN_3(ALU64, MOD,  X),			\
1535 	INSN_2(ALU64, NEG),			\
1536 	INSN_3(ALU64, END, TO_LE),		\
1537 	/*   Immediate based. */		\
1538 	INSN_3(ALU64, ADD,  K),			\
1539 	INSN_3(ALU64, SUB,  K),			\
1540 	INSN_3(ALU64, AND,  K),			\
1541 	INSN_3(ALU64, OR,   K),			\
1542 	INSN_3(ALU64, LSH,  K),			\
1543 	INSN_3(ALU64, RSH,  K),			\
1544 	INSN_3(ALU64, XOR,  K),			\
1545 	INSN_3(ALU64, MUL,  K),			\
1546 	INSN_3(ALU64, MOV,  K),			\
1547 	INSN_3(ALU64, ARSH, K),			\
1548 	INSN_3(ALU64, DIV,  K),			\
1549 	INSN_3(ALU64, MOD,  K),			\
1550 	/* Call instruction. */			\
1551 	INSN_2(JMP, CALL),			\
1552 	/* Exit instruction. */			\
1553 	INSN_2(JMP, EXIT),			\
1554 	/* 32-bit Jump instructions. */		\
1555 	/*   Register based. */			\
1556 	INSN_3(JMP32, JEQ,  X),			\
1557 	INSN_3(JMP32, JNE,  X),			\
1558 	INSN_3(JMP32, JGT,  X),			\
1559 	INSN_3(JMP32, JLT,  X),			\
1560 	INSN_3(JMP32, JGE,  X),			\
1561 	INSN_3(JMP32, JLE,  X),			\
1562 	INSN_3(JMP32, JSGT, X),			\
1563 	INSN_3(JMP32, JSLT, X),			\
1564 	INSN_3(JMP32, JSGE, X),			\
1565 	INSN_3(JMP32, JSLE, X),			\
1566 	INSN_3(JMP32, JSET, X),			\
1567 	/*   Immediate based. */		\
1568 	INSN_3(JMP32, JEQ,  K),			\
1569 	INSN_3(JMP32, JNE,  K),			\
1570 	INSN_3(JMP32, JGT,  K),			\
1571 	INSN_3(JMP32, JLT,  K),			\
1572 	INSN_3(JMP32, JGE,  K),			\
1573 	INSN_3(JMP32, JLE,  K),			\
1574 	INSN_3(JMP32, JSGT, K),			\
1575 	INSN_3(JMP32, JSLT, K),			\
1576 	INSN_3(JMP32, JSGE, K),			\
1577 	INSN_3(JMP32, JSLE, K),			\
1578 	INSN_3(JMP32, JSET, K),			\
1579 	/* Jump instructions. */		\
1580 	/*   Register based. */			\
1581 	INSN_3(JMP, JEQ,  X),			\
1582 	INSN_3(JMP, JNE,  X),			\
1583 	INSN_3(JMP, JGT,  X),			\
1584 	INSN_3(JMP, JLT,  X),			\
1585 	INSN_3(JMP, JGE,  X),			\
1586 	INSN_3(JMP, JLE,  X),			\
1587 	INSN_3(JMP, JSGT, X),			\
1588 	INSN_3(JMP, JSLT, X),			\
1589 	INSN_3(JMP, JSGE, X),			\
1590 	INSN_3(JMP, JSLE, X),			\
1591 	INSN_3(JMP, JSET, X),			\
1592 	/*   Immediate based. */		\
1593 	INSN_3(JMP, JEQ,  K),			\
1594 	INSN_3(JMP, JNE,  K),			\
1595 	INSN_3(JMP, JGT,  K),			\
1596 	INSN_3(JMP, JLT,  K),			\
1597 	INSN_3(JMP, JGE,  K),			\
1598 	INSN_3(JMP, JLE,  K),			\
1599 	INSN_3(JMP, JSGT, K),			\
1600 	INSN_3(JMP, JSLT, K),			\
1601 	INSN_3(JMP, JSGE, K),			\
1602 	INSN_3(JMP, JSLE, K),			\
1603 	INSN_3(JMP, JSET, K),			\
1604 	INSN_2(JMP, JA),			\
1605 	INSN_2(JMP32, JA),			\
1606 	/* Store instructions. */		\
1607 	/*   Register based. */			\
1608 	INSN_3(STX, MEM,  B),			\
1609 	INSN_3(STX, MEM,  H),			\
1610 	INSN_3(STX, MEM,  W),			\
1611 	INSN_3(STX, MEM,  DW),			\
1612 	INSN_3(STX, ATOMIC, W),			\
1613 	INSN_3(STX, ATOMIC, DW),		\
1614 	/*   Immediate based. */		\
1615 	INSN_3(ST, MEM, B),			\
1616 	INSN_3(ST, MEM, H),			\
1617 	INSN_3(ST, MEM, W),			\
1618 	INSN_3(ST, MEM, DW),			\
1619 	/* Load instructions. */		\
1620 	/*   Register based. */			\
1621 	INSN_3(LDX, MEM, B),			\
1622 	INSN_3(LDX, MEM, H),			\
1623 	INSN_3(LDX, MEM, W),			\
1624 	INSN_3(LDX, MEM, DW),			\
1625 	INSN_3(LDX, MEMSX, B),			\
1626 	INSN_3(LDX, MEMSX, H),			\
1627 	INSN_3(LDX, MEMSX, W),			\
1628 	/*   Immediate based. */		\
1629 	INSN_3(LD, IMM, DW)
1630 
bpf_opcode_in_insntable(u8 code)1631 bool bpf_opcode_in_insntable(u8 code)
1632 {
1633 #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
1634 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1635 	static const bool public_insntable[256] = {
1636 		[0 ... 255] = false,
1637 		/* Now overwrite non-defaults ... */
1638 		BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1639 		/* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1640 		[BPF_LD | BPF_ABS | BPF_B] = true,
1641 		[BPF_LD | BPF_ABS | BPF_H] = true,
1642 		[BPF_LD | BPF_ABS | BPF_W] = true,
1643 		[BPF_LD | BPF_IND | BPF_B] = true,
1644 		[BPF_LD | BPF_IND | BPF_H] = true,
1645 		[BPF_LD | BPF_IND | BPF_W] = true,
1646 	};
1647 #undef BPF_INSN_3_TBL
1648 #undef BPF_INSN_2_TBL
1649 	return public_insntable[code];
1650 }
1651 
1652 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1653 /**
1654  *	___bpf_prog_run - run eBPF program on a given context
1655  *	@regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1656  *	@insn: is the array of eBPF instructions
1657  *
1658  * Decode and execute eBPF instructions.
1659  *
1660  * Return: whatever value is in %BPF_R0 at program exit
1661  */
___bpf_prog_run(u64 * regs,const struct bpf_insn * insn)1662 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1663 {
1664 #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
1665 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1666 	static const void * const jumptable[256] __annotate_jump_table = {
1667 		[0 ... 255] = &&default_label,
1668 		/* Now overwrite non-defaults ... */
1669 		BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1670 		/* Non-UAPI available opcodes. */
1671 		[BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1672 		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1673 		[BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
1674 		[BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1675 		[BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1676 		[BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1677 		[BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1678 		[BPF_LDX | BPF_PROBE_MEMSX | BPF_B] = &&LDX_PROBE_MEMSX_B,
1679 		[BPF_LDX | BPF_PROBE_MEMSX | BPF_H] = &&LDX_PROBE_MEMSX_H,
1680 		[BPF_LDX | BPF_PROBE_MEMSX | BPF_W] = &&LDX_PROBE_MEMSX_W,
1681 	};
1682 #undef BPF_INSN_3_LBL
1683 #undef BPF_INSN_2_LBL
1684 	u32 tail_call_cnt = 0;
1685 
1686 #define CONT	 ({ insn++; goto select_insn; })
1687 #define CONT_JMP ({ insn++; goto select_insn; })
1688 
1689 select_insn:
1690 	goto *jumptable[insn->code];
1691 
1692 	/* Explicitly mask the register-based shift amounts with 63 or 31
1693 	 * to avoid undefined behavior. Normally this won't affect the
1694 	 * generated code, for example, in case of native 64 bit archs such
1695 	 * as x86-64 or arm64, the compiler is optimizing the AND away for
1696 	 * the interpreter. In case of JITs, each of the JIT backends compiles
1697 	 * the BPF shift operations to machine instructions which produce
1698 	 * implementation-defined results in such a case; the resulting
1699 	 * contents of the register may be arbitrary, but program behaviour
1700 	 * as a whole remains defined. In other words, in case of JIT backends,
1701 	 * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1702 	 */
1703 	/* ALU (shifts) */
1704 #define SHT(OPCODE, OP)					\
1705 	ALU64_##OPCODE##_X:				\
1706 		DST = DST OP (SRC & 63);		\
1707 		CONT;					\
1708 	ALU_##OPCODE##_X:				\
1709 		DST = (u32) DST OP ((u32) SRC & 31);	\
1710 		CONT;					\
1711 	ALU64_##OPCODE##_K:				\
1712 		DST = DST OP IMM;			\
1713 		CONT;					\
1714 	ALU_##OPCODE##_K:				\
1715 		DST = (u32) DST OP (u32) IMM;		\
1716 		CONT;
1717 	/* ALU (rest) */
1718 #define ALU(OPCODE, OP)					\
1719 	ALU64_##OPCODE##_X:				\
1720 		DST = DST OP SRC;			\
1721 		CONT;					\
1722 	ALU_##OPCODE##_X:				\
1723 		DST = (u32) DST OP (u32) SRC;		\
1724 		CONT;					\
1725 	ALU64_##OPCODE##_K:				\
1726 		DST = DST OP IMM;			\
1727 		CONT;					\
1728 	ALU_##OPCODE##_K:				\
1729 		DST = (u32) DST OP (u32) IMM;		\
1730 		CONT;
1731 	ALU(ADD,  +)
1732 	ALU(SUB,  -)
1733 	ALU(AND,  &)
1734 	ALU(OR,   |)
1735 	ALU(XOR,  ^)
1736 	ALU(MUL,  *)
1737 	SHT(LSH, <<)
1738 	SHT(RSH, >>)
1739 #undef SHT
1740 #undef ALU
1741 	ALU_NEG:
1742 		DST = (u32) -DST;
1743 		CONT;
1744 	ALU64_NEG:
1745 		DST = -DST;
1746 		CONT;
1747 	ALU_MOV_X:
1748 		switch (OFF) {
1749 		case 0:
1750 			DST = (u32) SRC;
1751 			break;
1752 		case 8:
1753 			DST = (u32)(s8) SRC;
1754 			break;
1755 		case 16:
1756 			DST = (u32)(s16) SRC;
1757 			break;
1758 		}
1759 		CONT;
1760 	ALU_MOV_K:
1761 		DST = (u32) IMM;
1762 		CONT;
1763 	ALU64_MOV_X:
1764 		switch (OFF) {
1765 		case 0:
1766 			DST = SRC;
1767 			break;
1768 		case 8:
1769 			DST = (s8) SRC;
1770 			break;
1771 		case 16:
1772 			DST = (s16) SRC;
1773 			break;
1774 		case 32:
1775 			DST = (s32) SRC;
1776 			break;
1777 		}
1778 		CONT;
1779 	ALU64_MOV_K:
1780 		DST = IMM;
1781 		CONT;
1782 	LD_IMM_DW:
1783 		DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1784 		insn++;
1785 		CONT;
1786 	ALU_ARSH_X:
1787 		DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1788 		CONT;
1789 	ALU_ARSH_K:
1790 		DST = (u64) (u32) (((s32) DST) >> IMM);
1791 		CONT;
1792 	ALU64_ARSH_X:
1793 		(*(s64 *) &DST) >>= (SRC & 63);
1794 		CONT;
1795 	ALU64_ARSH_K:
1796 		(*(s64 *) &DST) >>= IMM;
1797 		CONT;
1798 	ALU64_MOD_X:
1799 		switch (OFF) {
1800 		case 0:
1801 			div64_u64_rem(DST, SRC, &AX);
1802 			DST = AX;
1803 			break;
1804 		case 1:
1805 			AX = div64_s64(DST, SRC);
1806 			DST = DST - AX * SRC;
1807 			break;
1808 		}
1809 		CONT;
1810 	ALU_MOD_X:
1811 		switch (OFF) {
1812 		case 0:
1813 			AX = (u32) DST;
1814 			DST = do_div(AX, (u32) SRC);
1815 			break;
1816 		case 1:
1817 			AX = abs((s32)DST);
1818 			AX = do_div(AX, abs((s32)SRC));
1819 			if ((s32)DST < 0)
1820 				DST = (u32)-AX;
1821 			else
1822 				DST = (u32)AX;
1823 			break;
1824 		}
1825 		CONT;
1826 	ALU64_MOD_K:
1827 		switch (OFF) {
1828 		case 0:
1829 			div64_u64_rem(DST, IMM, &AX);
1830 			DST = AX;
1831 			break;
1832 		case 1:
1833 			AX = div64_s64(DST, IMM);
1834 			DST = DST - AX * IMM;
1835 			break;
1836 		}
1837 		CONT;
1838 	ALU_MOD_K:
1839 		switch (OFF) {
1840 		case 0:
1841 			AX = (u32) DST;
1842 			DST = do_div(AX, (u32) IMM);
1843 			break;
1844 		case 1:
1845 			AX = abs((s32)DST);
1846 			AX = do_div(AX, abs((s32)IMM));
1847 			if ((s32)DST < 0)
1848 				DST = (u32)-AX;
1849 			else
1850 				DST = (u32)AX;
1851 			break;
1852 		}
1853 		CONT;
1854 	ALU64_DIV_X:
1855 		switch (OFF) {
1856 		case 0:
1857 			DST = div64_u64(DST, SRC);
1858 			break;
1859 		case 1:
1860 			DST = div64_s64(DST, SRC);
1861 			break;
1862 		}
1863 		CONT;
1864 	ALU_DIV_X:
1865 		switch (OFF) {
1866 		case 0:
1867 			AX = (u32) DST;
1868 			do_div(AX, (u32) SRC);
1869 			DST = (u32) AX;
1870 			break;
1871 		case 1:
1872 			AX = abs((s32)DST);
1873 			do_div(AX, abs((s32)SRC));
1874 			if (((s32)DST < 0) == ((s32)SRC < 0))
1875 				DST = (u32)AX;
1876 			else
1877 				DST = (u32)-AX;
1878 			break;
1879 		}
1880 		CONT;
1881 	ALU64_DIV_K:
1882 		switch (OFF) {
1883 		case 0:
1884 			DST = div64_u64(DST, IMM);
1885 			break;
1886 		case 1:
1887 			DST = div64_s64(DST, IMM);
1888 			break;
1889 		}
1890 		CONT;
1891 	ALU_DIV_K:
1892 		switch (OFF) {
1893 		case 0:
1894 			AX = (u32) DST;
1895 			do_div(AX, (u32) IMM);
1896 			DST = (u32) AX;
1897 			break;
1898 		case 1:
1899 			AX = abs((s32)DST);
1900 			do_div(AX, abs((s32)IMM));
1901 			if (((s32)DST < 0) == ((s32)IMM < 0))
1902 				DST = (u32)AX;
1903 			else
1904 				DST = (u32)-AX;
1905 			break;
1906 		}
1907 		CONT;
1908 	ALU_END_TO_BE:
1909 		switch (IMM) {
1910 		case 16:
1911 			DST = (__force u16) cpu_to_be16(DST);
1912 			break;
1913 		case 32:
1914 			DST = (__force u32) cpu_to_be32(DST);
1915 			break;
1916 		case 64:
1917 			DST = (__force u64) cpu_to_be64(DST);
1918 			break;
1919 		}
1920 		CONT;
1921 	ALU_END_TO_LE:
1922 		switch (IMM) {
1923 		case 16:
1924 			DST = (__force u16) cpu_to_le16(DST);
1925 			break;
1926 		case 32:
1927 			DST = (__force u32) cpu_to_le32(DST);
1928 			break;
1929 		case 64:
1930 			DST = (__force u64) cpu_to_le64(DST);
1931 			break;
1932 		}
1933 		CONT;
1934 	ALU64_END_TO_LE:
1935 		switch (IMM) {
1936 		case 16:
1937 			DST = (__force u16) __swab16(DST);
1938 			break;
1939 		case 32:
1940 			DST = (__force u32) __swab32(DST);
1941 			break;
1942 		case 64:
1943 			DST = (__force u64) __swab64(DST);
1944 			break;
1945 		}
1946 		CONT;
1947 
1948 	/* CALL */
1949 	JMP_CALL:
1950 		/* Function call scratches BPF_R1-BPF_R5 registers,
1951 		 * preserves BPF_R6-BPF_R9, and stores return value
1952 		 * into BPF_R0.
1953 		 */
1954 		BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1955 						       BPF_R4, BPF_R5);
1956 		CONT;
1957 
1958 	JMP_CALL_ARGS:
1959 		BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
1960 							    BPF_R3, BPF_R4,
1961 							    BPF_R5,
1962 							    insn + insn->off + 1);
1963 		CONT;
1964 
1965 	JMP_TAIL_CALL: {
1966 		struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1967 		struct bpf_array *array = container_of(map, struct bpf_array, map);
1968 		struct bpf_prog *prog;
1969 		u32 index = BPF_R3;
1970 
1971 		if (unlikely(index >= array->map.max_entries))
1972 			goto out;
1973 
1974 		if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
1975 			goto out;
1976 
1977 		tail_call_cnt++;
1978 
1979 		prog = READ_ONCE(array->ptrs[index]);
1980 		if (!prog)
1981 			goto out;
1982 
1983 		/* ARG1 at this point is guaranteed to point to CTX from
1984 		 * the verifier side due to the fact that the tail call is
1985 		 * handled like a helper, that is, bpf_tail_call_proto,
1986 		 * where arg1_type is ARG_PTR_TO_CTX.
1987 		 */
1988 		insn = prog->insnsi;
1989 		goto select_insn;
1990 out:
1991 		CONT;
1992 	}
1993 	JMP_JA:
1994 		insn += insn->off;
1995 		CONT;
1996 	JMP32_JA:
1997 		insn += insn->imm;
1998 		CONT;
1999 	JMP_EXIT:
2000 		return BPF_R0;
2001 	/* JMP */
2002 #define COND_JMP(SIGN, OPCODE, CMP_OP)				\
2003 	JMP_##OPCODE##_X:					\
2004 		if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {	\
2005 			insn += insn->off;			\
2006 			CONT_JMP;				\
2007 		}						\
2008 		CONT;						\
2009 	JMP32_##OPCODE##_X:					\
2010 		if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {	\
2011 			insn += insn->off;			\
2012 			CONT_JMP;				\
2013 		}						\
2014 		CONT;						\
2015 	JMP_##OPCODE##_K:					\
2016 		if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {	\
2017 			insn += insn->off;			\
2018 			CONT_JMP;				\
2019 		}						\
2020 		CONT;						\
2021 	JMP32_##OPCODE##_K:					\
2022 		if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {	\
2023 			insn += insn->off;			\
2024 			CONT_JMP;				\
2025 		}						\
2026 		CONT;
2027 	COND_JMP(u, JEQ, ==)
2028 	COND_JMP(u, JNE, !=)
2029 	COND_JMP(u, JGT, >)
2030 	COND_JMP(u, JLT, <)
2031 	COND_JMP(u, JGE, >=)
2032 	COND_JMP(u, JLE, <=)
2033 	COND_JMP(u, JSET, &)
2034 	COND_JMP(s, JSGT, >)
2035 	COND_JMP(s, JSLT, <)
2036 	COND_JMP(s, JSGE, >=)
2037 	COND_JMP(s, JSLE, <=)
2038 #undef COND_JMP
2039 	/* ST, STX and LDX*/
2040 	ST_NOSPEC:
2041 		/* Speculation barrier for mitigating Speculative Store Bypass.
2042 		 * In case of arm64, we rely on the firmware mitigation as
2043 		 * controlled via the ssbd kernel parameter. Whenever the
2044 		 * mitigation is enabled, it works for all of the kernel code
2045 		 * with no need to provide any additional instructions here.
2046 		 * In case of x86, we use 'lfence' insn for mitigation. We
2047 		 * reuse preexisting logic from Spectre v1 mitigation that
2048 		 * happens to produce the required code on x86 for v4 as well.
2049 		 */
2050 		barrier_nospec();
2051 		CONT;
2052 #define LDST(SIZEOP, SIZE)						\
2053 	STX_MEM_##SIZEOP:						\
2054 		*(SIZE *)(unsigned long) (DST + insn->off) = SRC;	\
2055 		CONT;							\
2056 	ST_MEM_##SIZEOP:						\
2057 		*(SIZE *)(unsigned long) (DST + insn->off) = IMM;	\
2058 		CONT;							\
2059 	LDX_MEM_##SIZEOP:						\
2060 		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
2061 		CONT;							\
2062 	LDX_PROBE_MEM_##SIZEOP:						\
2063 		bpf_probe_read_kernel_common(&DST, sizeof(SIZE),	\
2064 			      (const void *)(long) (SRC + insn->off));	\
2065 		DST = *((SIZE *)&DST);					\
2066 		CONT;
2067 
2068 	LDST(B,   u8)
2069 	LDST(H,  u16)
2070 	LDST(W,  u32)
2071 	LDST(DW, u64)
2072 #undef LDST
2073 
2074 #define LDSX(SIZEOP, SIZE)						\
2075 	LDX_MEMSX_##SIZEOP:						\
2076 		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
2077 		CONT;							\
2078 	LDX_PROBE_MEMSX_##SIZEOP:					\
2079 		bpf_probe_read_kernel_common(&DST, sizeof(SIZE),		\
2080 				      (const void *)(long) (SRC + insn->off));	\
2081 		DST = *((SIZE *)&DST);					\
2082 		CONT;
2083 
2084 	LDSX(B,   s8)
2085 	LDSX(H,  s16)
2086 	LDSX(W,  s32)
2087 #undef LDSX
2088 
2089 #define ATOMIC_ALU_OP(BOP, KOP)						\
2090 		case BOP:						\
2091 			if (BPF_SIZE(insn->code) == BPF_W)		\
2092 				atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
2093 					     (DST + insn->off));	\
2094 			else						\
2095 				atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
2096 					       (DST + insn->off));	\
2097 			break;						\
2098 		case BOP | BPF_FETCH:					\
2099 			if (BPF_SIZE(insn->code) == BPF_W)		\
2100 				SRC = (u32) atomic_fetch_##KOP(		\
2101 					(u32) SRC,			\
2102 					(atomic_t *)(unsigned long) (DST + insn->off)); \
2103 			else						\
2104 				SRC = (u64) atomic64_fetch_##KOP(	\
2105 					(u64) SRC,			\
2106 					(atomic64_t *)(unsigned long) (DST + insn->off)); \
2107 			break;
2108 
2109 	STX_ATOMIC_DW:
2110 	STX_ATOMIC_W:
2111 		switch (IMM) {
2112 		ATOMIC_ALU_OP(BPF_ADD, add)
2113 		ATOMIC_ALU_OP(BPF_AND, and)
2114 		ATOMIC_ALU_OP(BPF_OR, or)
2115 		ATOMIC_ALU_OP(BPF_XOR, xor)
2116 #undef ATOMIC_ALU_OP
2117 
2118 		case BPF_XCHG:
2119 			if (BPF_SIZE(insn->code) == BPF_W)
2120 				SRC = (u32) atomic_xchg(
2121 					(atomic_t *)(unsigned long) (DST + insn->off),
2122 					(u32) SRC);
2123 			else
2124 				SRC = (u64) atomic64_xchg(
2125 					(atomic64_t *)(unsigned long) (DST + insn->off),
2126 					(u64) SRC);
2127 			break;
2128 		case BPF_CMPXCHG:
2129 			if (BPF_SIZE(insn->code) == BPF_W)
2130 				BPF_R0 = (u32) atomic_cmpxchg(
2131 					(atomic_t *)(unsigned long) (DST + insn->off),
2132 					(u32) BPF_R0, (u32) SRC);
2133 			else
2134 				BPF_R0 = (u64) atomic64_cmpxchg(
2135 					(atomic64_t *)(unsigned long) (DST + insn->off),
2136 					(u64) BPF_R0, (u64) SRC);
2137 			break;
2138 
2139 		default:
2140 			goto default_label;
2141 		}
2142 		CONT;
2143 
2144 	default_label:
2145 		/* If we ever reach this, we have a bug somewhere. Die hard here
2146 		 * instead of just returning 0; we could be somewhere in a subprog,
2147 		 * so execution could continue otherwise which we do /not/ want.
2148 		 *
2149 		 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2150 		 */
2151 		pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2152 			insn->code, insn->imm);
2153 		BUG_ON(1);
2154 		return 0;
2155 }
2156 
2157 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2158 #define DEFINE_BPF_PROG_RUN(stack_size) \
2159 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2160 { \
2161 	u64 stack[stack_size / sizeof(u64)]; \
2162 	u64 regs[MAX_BPF_EXT_REG] = {}; \
2163 \
2164 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2165 	ARG1 = (u64) (unsigned long) ctx; \
2166 	return ___bpf_prog_run(regs, insn); \
2167 }
2168 
2169 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2170 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2171 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2172 				      const struct bpf_insn *insn) \
2173 { \
2174 	u64 stack[stack_size / sizeof(u64)]; \
2175 	u64 regs[MAX_BPF_EXT_REG]; \
2176 \
2177 	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2178 	BPF_R1 = r1; \
2179 	BPF_R2 = r2; \
2180 	BPF_R3 = r3; \
2181 	BPF_R4 = r4; \
2182 	BPF_R5 = r5; \
2183 	return ___bpf_prog_run(regs, insn); \
2184 }
2185 
2186 #define EVAL1(FN, X) FN(X)
2187 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2188 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2189 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2190 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2191 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2192 
2193 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2194 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2195 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2196 
2197 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2198 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2199 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2200 
2201 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2202 
2203 static unsigned int (*interpreters[])(const void *ctx,
2204 				      const struct bpf_insn *insn) = {
2205 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2206 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2207 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2208 };
2209 #undef PROG_NAME_LIST
2210 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2211 static __maybe_unused
2212 u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2213 			   const struct bpf_insn *insn) = {
2214 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2215 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2216 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2217 };
2218 #undef PROG_NAME_LIST
2219 
2220 #ifdef CONFIG_BPF_SYSCALL
bpf_patch_call_args(struct bpf_insn * insn,u32 stack_depth)2221 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2222 {
2223 	stack_depth = max_t(u32, stack_depth, 1);
2224 	insn->off = (s16) insn->imm;
2225 	insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
2226 		__bpf_call_base_args;
2227 	insn->code = BPF_JMP | BPF_CALL_ARGS;
2228 }
2229 #endif
2230 #else
__bpf_prog_ret0_warn(const void * ctx,const struct bpf_insn * insn)2231 static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2232 					 const struct bpf_insn *insn)
2233 {
2234 	/* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2235 	 * is not working properly, so warn about it!
2236 	 */
2237 	WARN_ON_ONCE(1);
2238 	return 0;
2239 }
2240 #endif
2241 
bpf_prog_map_compatible(struct bpf_map * map,const struct bpf_prog * fp)2242 bool bpf_prog_map_compatible(struct bpf_map *map,
2243 			     const struct bpf_prog *fp)
2244 {
2245 	enum bpf_prog_type prog_type = resolve_prog_type(fp);
2246 	bool ret;
2247 
2248 	if (fp->kprobe_override)
2249 		return false;
2250 
2251 	/* XDP programs inserted into maps are not guaranteed to run on
2252 	 * a particular netdev (and can run outside driver context entirely
2253 	 * in the case of devmap and cpumap). Until device checks
2254 	 * are implemented, prohibit adding dev-bound programs to program maps.
2255 	 */
2256 	if (bpf_prog_is_dev_bound(fp->aux))
2257 		return false;
2258 
2259 	spin_lock(&map->owner.lock);
2260 	if (!map->owner.type) {
2261 		/* There's no owner yet where we could check for
2262 		 * compatibility.
2263 		 */
2264 		map->owner.type  = prog_type;
2265 		map->owner.jited = fp->jited;
2266 		map->owner.xdp_has_frags = fp->aux->xdp_has_frags;
2267 		ret = true;
2268 	} else {
2269 		ret = map->owner.type  == prog_type &&
2270 		      map->owner.jited == fp->jited &&
2271 		      map->owner.xdp_has_frags == fp->aux->xdp_has_frags;
2272 	}
2273 	spin_unlock(&map->owner.lock);
2274 
2275 	return ret;
2276 }
2277 
bpf_check_tail_call(const struct bpf_prog * fp)2278 static int bpf_check_tail_call(const struct bpf_prog *fp)
2279 {
2280 	struct bpf_prog_aux *aux = fp->aux;
2281 	int i, ret = 0;
2282 
2283 	mutex_lock(&aux->used_maps_mutex);
2284 	for (i = 0; i < aux->used_map_cnt; i++) {
2285 		struct bpf_map *map = aux->used_maps[i];
2286 
2287 		if (!map_type_contains_progs(map))
2288 			continue;
2289 
2290 		if (!bpf_prog_map_compatible(map, fp)) {
2291 			ret = -EINVAL;
2292 			goto out;
2293 		}
2294 	}
2295 
2296 out:
2297 	mutex_unlock(&aux->used_maps_mutex);
2298 	return ret;
2299 }
2300 
bpf_prog_select_func(struct bpf_prog * fp)2301 static void bpf_prog_select_func(struct bpf_prog *fp)
2302 {
2303 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
2304 	u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2305 
2306 	fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
2307 #else
2308 	fp->bpf_func = __bpf_prog_ret0_warn;
2309 #endif
2310 }
2311 
2312 /**
2313  *	bpf_prog_select_runtime - select exec runtime for BPF program
2314  *	@fp: bpf_prog populated with BPF program
2315  *	@err: pointer to error variable
2316  *
2317  * Try to JIT eBPF program, if JIT is not available, use interpreter.
2318  * The BPF program will be executed via bpf_prog_run() function.
2319  *
2320  * Return: the &fp argument along with &err set to 0 for success or
2321  * a negative errno code on failure
2322  */
bpf_prog_select_runtime(struct bpf_prog * fp,int * err)2323 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2324 {
2325 	/* In case of BPF to BPF calls, verifier did all the prep
2326 	 * work with regards to JITing, etc.
2327 	 */
2328 	bool jit_needed = false;
2329 
2330 	if (fp->bpf_func)
2331 		goto finalize;
2332 
2333 	if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
2334 	    bpf_prog_has_kfunc_call(fp))
2335 		jit_needed = true;
2336 
2337 	bpf_prog_select_func(fp);
2338 
2339 	/* eBPF JITs can rewrite the program in case constant
2340 	 * blinding is active. However, in case of error during
2341 	 * blinding, bpf_int_jit_compile() must always return a
2342 	 * valid program, which in this case would simply not
2343 	 * be JITed, but falls back to the interpreter.
2344 	 */
2345 	if (!bpf_prog_is_offloaded(fp->aux)) {
2346 		*err = bpf_prog_alloc_jited_linfo(fp);
2347 		if (*err)
2348 			return fp;
2349 
2350 		fp = bpf_int_jit_compile(fp);
2351 		bpf_prog_jit_attempt_done(fp);
2352 		if (!fp->jited && jit_needed) {
2353 			*err = -ENOTSUPP;
2354 			return fp;
2355 		}
2356 	} else {
2357 		*err = bpf_prog_offload_compile(fp);
2358 		if (*err)
2359 			return fp;
2360 	}
2361 
2362 finalize:
2363 	bpf_prog_lock_ro(fp);
2364 
2365 	/* The tail call compatibility check can only be done at
2366 	 * this late stage as we need to determine, if we deal
2367 	 * with JITed or non JITed program concatenations and not
2368 	 * all eBPF JITs might immediately support all features.
2369 	 */
2370 	*err = bpf_check_tail_call(fp);
2371 
2372 	return fp;
2373 }
2374 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2375 
__bpf_prog_ret1(const void * ctx,const struct bpf_insn * insn)2376 static unsigned int __bpf_prog_ret1(const void *ctx,
2377 				    const struct bpf_insn *insn)
2378 {
2379 	return 1;
2380 }
2381 
2382 static struct bpf_prog_dummy {
2383 	struct bpf_prog prog;
2384 } dummy_bpf_prog = {
2385 	.prog = {
2386 		.bpf_func = __bpf_prog_ret1,
2387 	},
2388 };
2389 
2390 struct bpf_empty_prog_array bpf_empty_prog_array = {
2391 	.null_prog = NULL,
2392 };
2393 EXPORT_SYMBOL(bpf_empty_prog_array);
2394 
bpf_prog_array_alloc(u32 prog_cnt,gfp_t flags)2395 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2396 {
2397 	if (prog_cnt)
2398 		return kzalloc(sizeof(struct bpf_prog_array) +
2399 			       sizeof(struct bpf_prog_array_item) *
2400 			       (prog_cnt + 1),
2401 			       flags);
2402 
2403 	return &bpf_empty_prog_array.hdr;
2404 }
2405 
bpf_prog_array_free(struct bpf_prog_array * progs)2406 void bpf_prog_array_free(struct bpf_prog_array *progs)
2407 {
2408 	if (!progs || progs == &bpf_empty_prog_array.hdr)
2409 		return;
2410 	kfree_rcu(progs, rcu);
2411 }
2412 
__bpf_prog_array_free_sleepable_cb(struct rcu_head * rcu)2413 static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2414 {
2415 	struct bpf_prog_array *progs;
2416 
2417 	/* If RCU Tasks Trace grace period implies RCU grace period, there is
2418 	 * no need to call kfree_rcu(), just call kfree() directly.
2419 	 */
2420 	progs = container_of(rcu, struct bpf_prog_array, rcu);
2421 	if (rcu_trace_implies_rcu_gp())
2422 		kfree(progs);
2423 	else
2424 		kfree_rcu(progs, rcu);
2425 }
2426 
bpf_prog_array_free_sleepable(struct bpf_prog_array * progs)2427 void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2428 {
2429 	if (!progs || progs == &bpf_empty_prog_array.hdr)
2430 		return;
2431 	call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2432 }
2433 
bpf_prog_array_length(struct bpf_prog_array * array)2434 int bpf_prog_array_length(struct bpf_prog_array *array)
2435 {
2436 	struct bpf_prog_array_item *item;
2437 	u32 cnt = 0;
2438 
2439 	for (item = array->items; item->prog; item++)
2440 		if (item->prog != &dummy_bpf_prog.prog)
2441 			cnt++;
2442 	return cnt;
2443 }
2444 
bpf_prog_array_is_empty(struct bpf_prog_array * array)2445 bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2446 {
2447 	struct bpf_prog_array_item *item;
2448 
2449 	for (item = array->items; item->prog; item++)
2450 		if (item->prog != &dummy_bpf_prog.prog)
2451 			return false;
2452 	return true;
2453 }
2454 
bpf_prog_array_copy_core(struct bpf_prog_array * array,u32 * prog_ids,u32 request_cnt)2455 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2456 				     u32 *prog_ids,
2457 				     u32 request_cnt)
2458 {
2459 	struct bpf_prog_array_item *item;
2460 	int i = 0;
2461 
2462 	for (item = array->items; item->prog; item++) {
2463 		if (item->prog == &dummy_bpf_prog.prog)
2464 			continue;
2465 		prog_ids[i] = item->prog->aux->id;
2466 		if (++i == request_cnt) {
2467 			item++;
2468 			break;
2469 		}
2470 	}
2471 
2472 	return !!(item->prog);
2473 }
2474 
bpf_prog_array_copy_to_user(struct bpf_prog_array * array,__u32 __user * prog_ids,u32 cnt)2475 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2476 				__u32 __user *prog_ids, u32 cnt)
2477 {
2478 	unsigned long err = 0;
2479 	bool nospc;
2480 	u32 *ids;
2481 
2482 	/* users of this function are doing:
2483 	 * cnt = bpf_prog_array_length();
2484 	 * if (cnt > 0)
2485 	 *     bpf_prog_array_copy_to_user(..., cnt);
2486 	 * so below kcalloc doesn't need extra cnt > 0 check.
2487 	 */
2488 	ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2489 	if (!ids)
2490 		return -ENOMEM;
2491 	nospc = bpf_prog_array_copy_core(array, ids, cnt);
2492 	err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2493 	kfree(ids);
2494 	if (err)
2495 		return -EFAULT;
2496 	if (nospc)
2497 		return -ENOSPC;
2498 	return 0;
2499 }
2500 
bpf_prog_array_delete_safe(struct bpf_prog_array * array,struct bpf_prog * old_prog)2501 void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2502 				struct bpf_prog *old_prog)
2503 {
2504 	struct bpf_prog_array_item *item;
2505 
2506 	for (item = array->items; item->prog; item++)
2507 		if (item->prog == old_prog) {
2508 			WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2509 			break;
2510 		}
2511 }
2512 
2513 /**
2514  * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2515  *                                   index into the program array with
2516  *                                   a dummy no-op program.
2517  * @array: a bpf_prog_array
2518  * @index: the index of the program to replace
2519  *
2520  * Skips over dummy programs, by not counting them, when calculating
2521  * the position of the program to replace.
2522  *
2523  * Return:
2524  * * 0		- Success
2525  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2526  * * -ENOENT	- Index out of range
2527  */
bpf_prog_array_delete_safe_at(struct bpf_prog_array * array,int index)2528 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2529 {
2530 	return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2531 }
2532 
2533 /**
2534  * bpf_prog_array_update_at() - Updates the program at the given index
2535  *                              into the program array.
2536  * @array: a bpf_prog_array
2537  * @index: the index of the program to update
2538  * @prog: the program to insert into the array
2539  *
2540  * Skips over dummy programs, by not counting them, when calculating
2541  * the position of the program to update.
2542  *
2543  * Return:
2544  * * 0		- Success
2545  * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2546  * * -ENOENT	- Index out of range
2547  */
bpf_prog_array_update_at(struct bpf_prog_array * array,int index,struct bpf_prog * prog)2548 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2549 			     struct bpf_prog *prog)
2550 {
2551 	struct bpf_prog_array_item *item;
2552 
2553 	if (unlikely(index < 0))
2554 		return -EINVAL;
2555 
2556 	for (item = array->items; item->prog; item++) {
2557 		if (item->prog == &dummy_bpf_prog.prog)
2558 			continue;
2559 		if (!index) {
2560 			WRITE_ONCE(item->prog, prog);
2561 			return 0;
2562 		}
2563 		index--;
2564 	}
2565 	return -ENOENT;
2566 }
2567 
bpf_prog_array_copy(struct bpf_prog_array * old_array,struct bpf_prog * exclude_prog,struct bpf_prog * include_prog,u64 bpf_cookie,struct bpf_prog_array ** new_array)2568 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2569 			struct bpf_prog *exclude_prog,
2570 			struct bpf_prog *include_prog,
2571 			u64 bpf_cookie,
2572 			struct bpf_prog_array **new_array)
2573 {
2574 	int new_prog_cnt, carry_prog_cnt = 0;
2575 	struct bpf_prog_array_item *existing, *new;
2576 	struct bpf_prog_array *array;
2577 	bool found_exclude = false;
2578 
2579 	/* Figure out how many existing progs we need to carry over to
2580 	 * the new array.
2581 	 */
2582 	if (old_array) {
2583 		existing = old_array->items;
2584 		for (; existing->prog; existing++) {
2585 			if (existing->prog == exclude_prog) {
2586 				found_exclude = true;
2587 				continue;
2588 			}
2589 			if (existing->prog != &dummy_bpf_prog.prog)
2590 				carry_prog_cnt++;
2591 			if (existing->prog == include_prog)
2592 				return -EEXIST;
2593 		}
2594 	}
2595 
2596 	if (exclude_prog && !found_exclude)
2597 		return -ENOENT;
2598 
2599 	/* How many progs (not NULL) will be in the new array? */
2600 	new_prog_cnt = carry_prog_cnt;
2601 	if (include_prog)
2602 		new_prog_cnt += 1;
2603 
2604 	/* Do we have any prog (not NULL) in the new array? */
2605 	if (!new_prog_cnt) {
2606 		*new_array = NULL;
2607 		return 0;
2608 	}
2609 
2610 	/* +1 as the end of prog_array is marked with NULL */
2611 	array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2612 	if (!array)
2613 		return -ENOMEM;
2614 	new = array->items;
2615 
2616 	/* Fill in the new prog array */
2617 	if (carry_prog_cnt) {
2618 		existing = old_array->items;
2619 		for (; existing->prog; existing++) {
2620 			if (existing->prog == exclude_prog ||
2621 			    existing->prog == &dummy_bpf_prog.prog)
2622 				continue;
2623 
2624 			new->prog = existing->prog;
2625 			new->bpf_cookie = existing->bpf_cookie;
2626 			new++;
2627 		}
2628 	}
2629 	if (include_prog) {
2630 		new->prog = include_prog;
2631 		new->bpf_cookie = bpf_cookie;
2632 		new++;
2633 	}
2634 	new->prog = NULL;
2635 	*new_array = array;
2636 	return 0;
2637 }
2638 
bpf_prog_array_copy_info(struct bpf_prog_array * array,u32 * prog_ids,u32 request_cnt,u32 * prog_cnt)2639 int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2640 			     u32 *prog_ids, u32 request_cnt,
2641 			     u32 *prog_cnt)
2642 {
2643 	u32 cnt = 0;
2644 
2645 	if (array)
2646 		cnt = bpf_prog_array_length(array);
2647 
2648 	*prog_cnt = cnt;
2649 
2650 	/* return early if user requested only program count or nothing to copy */
2651 	if (!request_cnt || !cnt)
2652 		return 0;
2653 
2654 	/* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2655 	return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2656 								     : 0;
2657 }
2658 
__bpf_free_used_maps(struct bpf_prog_aux * aux,struct bpf_map ** used_maps,u32 len)2659 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2660 			  struct bpf_map **used_maps, u32 len)
2661 {
2662 	struct bpf_map *map;
2663 	u32 i;
2664 
2665 	for (i = 0; i < len; i++) {
2666 		map = used_maps[i];
2667 		if (map->ops->map_poke_untrack)
2668 			map->ops->map_poke_untrack(map, aux);
2669 		bpf_map_put(map);
2670 	}
2671 }
2672 
bpf_free_used_maps(struct bpf_prog_aux * aux)2673 static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2674 {
2675 	__bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2676 	kfree(aux->used_maps);
2677 }
2678 
__bpf_free_used_btfs(struct bpf_prog_aux * aux,struct btf_mod_pair * used_btfs,u32 len)2679 void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
2680 			  struct btf_mod_pair *used_btfs, u32 len)
2681 {
2682 #ifdef CONFIG_BPF_SYSCALL
2683 	struct btf_mod_pair *btf_mod;
2684 	u32 i;
2685 
2686 	for (i = 0; i < len; i++) {
2687 		btf_mod = &used_btfs[i];
2688 		if (btf_mod->module)
2689 			module_put(btf_mod->module);
2690 		btf_put(btf_mod->btf);
2691 	}
2692 #endif
2693 }
2694 
bpf_free_used_btfs(struct bpf_prog_aux * aux)2695 static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2696 {
2697 	__bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt);
2698 	kfree(aux->used_btfs);
2699 }
2700 
bpf_prog_free_deferred(struct work_struct * work)2701 static void bpf_prog_free_deferred(struct work_struct *work)
2702 {
2703 	struct bpf_prog_aux *aux;
2704 	int i;
2705 
2706 	aux = container_of(work, struct bpf_prog_aux, work);
2707 #ifdef CONFIG_BPF_SYSCALL
2708 	bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
2709 #endif
2710 #ifdef CONFIG_CGROUP_BPF
2711 	if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
2712 		bpf_cgroup_atype_put(aux->cgroup_atype);
2713 #endif
2714 	bpf_free_used_maps(aux);
2715 	bpf_free_used_btfs(aux);
2716 	if (bpf_prog_is_dev_bound(aux))
2717 		bpf_prog_dev_bound_destroy(aux->prog);
2718 #ifdef CONFIG_PERF_EVENTS
2719 	if (aux->prog->has_callchain_buf)
2720 		put_callchain_buffers();
2721 #endif
2722 	if (aux->dst_trampoline)
2723 		bpf_trampoline_put(aux->dst_trampoline);
2724 	for (i = 0; i < aux->func_cnt; i++) {
2725 		/* We can just unlink the subprog poke descriptor table as
2726 		 * it was originally linked to the main program and is also
2727 		 * released along with it.
2728 		 */
2729 		aux->func[i]->aux->poke_tab = NULL;
2730 		bpf_jit_free(aux->func[i]);
2731 	}
2732 	if (aux->func_cnt) {
2733 		kfree(aux->func);
2734 		bpf_prog_unlock_free(aux->prog);
2735 	} else {
2736 		bpf_jit_free(aux->prog);
2737 	}
2738 }
2739 
bpf_prog_free(struct bpf_prog * fp)2740 void bpf_prog_free(struct bpf_prog *fp)
2741 {
2742 	struct bpf_prog_aux *aux = fp->aux;
2743 
2744 	if (aux->dst_prog)
2745 		bpf_prog_put(aux->dst_prog);
2746 	INIT_WORK(&aux->work, bpf_prog_free_deferred);
2747 	schedule_work(&aux->work);
2748 }
2749 EXPORT_SYMBOL_GPL(bpf_prog_free);
2750 
2751 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
2752 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2753 
bpf_user_rnd_init_once(void)2754 void bpf_user_rnd_init_once(void)
2755 {
2756 	prandom_init_once(&bpf_user_rnd_state);
2757 }
2758 
BPF_CALL_0(bpf_user_rnd_u32)2759 BPF_CALL_0(bpf_user_rnd_u32)
2760 {
2761 	/* Should someone ever have the rather unwise idea to use some
2762 	 * of the registers passed into this function, then note that
2763 	 * this function is called from native eBPF and classic-to-eBPF
2764 	 * transformations. Register assignments from both sides are
2765 	 * different, f.e. classic always sets fn(ctx, A, X) here.
2766 	 */
2767 	struct rnd_state *state;
2768 	u32 res;
2769 
2770 	state = &get_cpu_var(bpf_user_rnd_state);
2771 	res = prandom_u32_state(state);
2772 	put_cpu_var(bpf_user_rnd_state);
2773 
2774 	return res;
2775 }
2776 
BPF_CALL_0(bpf_get_raw_cpu_id)2777 BPF_CALL_0(bpf_get_raw_cpu_id)
2778 {
2779 	return raw_smp_processor_id();
2780 }
2781 
2782 /* Weak definitions of helper functions in case we don't have bpf syscall. */
2783 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2784 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2785 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2786 const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2787 const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2788 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2789 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
2790 const struct bpf_func_proto bpf_spin_lock_proto __weak;
2791 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2792 const struct bpf_func_proto bpf_jiffies64_proto __weak;
2793 
2794 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2795 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2796 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2797 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2798 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2799 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2800 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
2801 
2802 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2803 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2804 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2805 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2806 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2807 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2808 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2809 const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2810 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2811 const struct bpf_func_proto bpf_set_retval_proto __weak;
2812 const struct bpf_func_proto bpf_get_retval_proto __weak;
2813 
bpf_get_trace_printk_proto(void)2814 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2815 {
2816 	return NULL;
2817 }
2818 
bpf_get_trace_vprintk_proto(void)2819 const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
2820 {
2821 	return NULL;
2822 }
2823 
2824 u64 __weak
bpf_event_output(struct bpf_map * map,u64 flags,void * meta,u64 meta_size,void * ctx,u64 ctx_size,bpf_ctx_copy_t ctx_copy)2825 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2826 		 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2827 {
2828 	return -ENOTSUPP;
2829 }
2830 EXPORT_SYMBOL_GPL(bpf_event_output);
2831 
2832 /* Always built-in helper functions. */
2833 const struct bpf_func_proto bpf_tail_call_proto = {
2834 	.func		= NULL,
2835 	.gpl_only	= false,
2836 	.ret_type	= RET_VOID,
2837 	.arg1_type	= ARG_PTR_TO_CTX,
2838 	.arg2_type	= ARG_CONST_MAP_PTR,
2839 	.arg3_type	= ARG_ANYTHING,
2840 };
2841 
2842 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2843  * It is encouraged to implement bpf_int_jit_compile() instead, so that
2844  * eBPF and implicitly also cBPF can get JITed!
2845  */
bpf_int_jit_compile(struct bpf_prog * prog)2846 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2847 {
2848 	return prog;
2849 }
2850 
2851 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
2852  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2853  */
bpf_jit_compile(struct bpf_prog * prog)2854 void __weak bpf_jit_compile(struct bpf_prog *prog)
2855 {
2856 }
2857 
bpf_helper_changes_pkt_data(void * func)2858 bool __weak bpf_helper_changes_pkt_data(void *func)
2859 {
2860 	return false;
2861 }
2862 
2863 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2864  * analysis code and wants explicit zero extension inserted by verifier.
2865  * Otherwise, return FALSE.
2866  *
2867  * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2868  * you don't override this. JITs that don't want these extra insns can detect
2869  * them using insn_is_zext.
2870  */
bpf_jit_needs_zext(void)2871 bool __weak bpf_jit_needs_zext(void)
2872 {
2873 	return false;
2874 }
2875 
2876 /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
bpf_jit_supports_subprog_tailcalls(void)2877 bool __weak bpf_jit_supports_subprog_tailcalls(void)
2878 {
2879 	return false;
2880 }
2881 
bpf_jit_supports_kfunc_call(void)2882 bool __weak bpf_jit_supports_kfunc_call(void)
2883 {
2884 	return false;
2885 }
2886 
bpf_jit_supports_far_kfunc_call(void)2887 bool __weak bpf_jit_supports_far_kfunc_call(void)
2888 {
2889 	return false;
2890 }
2891 
2892 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
2893  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
2894  */
skb_copy_bits(const struct sk_buff * skb,int offset,void * to,int len)2895 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
2896 			 int len)
2897 {
2898 	return -EFAULT;
2899 }
2900 
bpf_arch_text_poke(void * ip,enum bpf_text_poke_type t,void * addr1,void * addr2)2901 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
2902 			      void *addr1, void *addr2)
2903 {
2904 	return -ENOTSUPP;
2905 }
2906 
bpf_arch_text_copy(void * dst,void * src,size_t len)2907 void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
2908 {
2909 	return ERR_PTR(-ENOTSUPP);
2910 }
2911 
bpf_arch_text_invalidate(void * dst,size_t len)2912 int __weak bpf_arch_text_invalidate(void *dst, size_t len)
2913 {
2914 	return -ENOTSUPP;
2915 }
2916 
2917 #ifdef CONFIG_BPF_SYSCALL
bpf_global_ma_init(void)2918 static int __init bpf_global_ma_init(void)
2919 {
2920 	int ret;
2921 
2922 	ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
2923 	bpf_global_ma_set = !ret;
2924 	return ret;
2925 }
2926 late_initcall(bpf_global_ma_init);
2927 #endif
2928 
2929 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
2930 EXPORT_SYMBOL(bpf_stats_enabled_key);
2931 
2932 /* All definitions of tracepoints related to BPF. */
2933 #define CREATE_TRACE_POINTS
2934 #include <linux/bpf_trace.h>
2935 
2936 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
2937 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);
2938