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Commit | Line | Data |
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f5bffecd AS |
1 | /* |
2 | * Linux Socket Filter - Kernel level socket filtering | |
3 | * | |
4 | * Based on the design of the Berkeley Packet Filter. The new | |
5 | * internal format has been designed by PLUMgrid: | |
6 | * | |
7 | * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com | |
8 | * | |
9 | * Authors: | |
10 | * | |
11 | * Jay Schulist <jschlst@samba.org> | |
12 | * Alexei Starovoitov <ast@plumgrid.com> | |
13 | * Daniel Borkmann <dborkman@redhat.com> | |
14 | * | |
15 | * This program is free software; you can redistribute it and/or | |
16 | * modify it under the terms of the GNU General Public License | |
17 | * as published by the Free Software Foundation; either version | |
18 | * 2 of the License, or (at your option) any later version. | |
19 | * | |
20 | * Andi Kleen - Fix a few bad bugs and races. | |
4df95ff4 | 21 | * Kris Katterjohn - Added many additional checks in bpf_check_classic() |
f5bffecd | 22 | */ |
738cbe72 | 23 | |
f5bffecd AS |
24 | #include <linux/filter.h> |
25 | #include <linux/skbuff.h> | |
60a3b225 | 26 | #include <linux/vmalloc.h> |
738cbe72 DB |
27 | #include <linux/random.h> |
28 | #include <linux/moduleloader.h> | |
09756af4 | 29 | #include <linux/bpf.h> |
39853cc0 | 30 | #include <linux/frame.h> |
74451e66 DB |
31 | #include <linux/rbtree_latch.h> |
32 | #include <linux/kallsyms.h> | |
33 | #include <linux/rcupdate.h> | |
f5bffecd | 34 | |
3324b584 DB |
35 | #include <asm/unaligned.h> |
36 | ||
f5bffecd AS |
37 | /* Registers */ |
38 | #define BPF_R0 regs[BPF_REG_0] | |
39 | #define BPF_R1 regs[BPF_REG_1] | |
40 | #define BPF_R2 regs[BPF_REG_2] | |
41 | #define BPF_R3 regs[BPF_REG_3] | |
42 | #define BPF_R4 regs[BPF_REG_4] | |
43 | #define BPF_R5 regs[BPF_REG_5] | |
44 | #define BPF_R6 regs[BPF_REG_6] | |
45 | #define BPF_R7 regs[BPF_REG_7] | |
46 | #define BPF_R8 regs[BPF_REG_8] | |
47 | #define BPF_R9 regs[BPF_REG_9] | |
48 | #define BPF_R10 regs[BPF_REG_10] | |
49 | ||
50 | /* Named registers */ | |
51 | #define DST regs[insn->dst_reg] | |
52 | #define SRC regs[insn->src_reg] | |
53 | #define FP regs[BPF_REG_FP] | |
54 | #define ARG1 regs[BPF_REG_ARG1] | |
55 | #define CTX regs[BPF_REG_CTX] | |
56 | #define IMM insn->imm | |
57 | ||
58 | /* No hurry in this branch | |
59 | * | |
60 | * Exported for the bpf jit load helper. | |
61 | */ | |
62 | void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) | |
63 | { | |
64 | u8 *ptr = NULL; | |
65 | ||
66 | if (k >= SKF_NET_OFF) | |
67 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; | |
68 | else if (k >= SKF_LL_OFF) | |
69 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; | |
3324b584 | 70 | |
f5bffecd AS |
71 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) |
72 | return ptr; | |
73 | ||
74 | return NULL; | |
75 | } | |
76 | ||
60a3b225 DB |
77 | struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) |
78 | { | |
79 | gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | | |
80 | gfp_extra_flags; | |
09756af4 | 81 | struct bpf_prog_aux *aux; |
60a3b225 DB |
82 | struct bpf_prog *fp; |
83 | ||
84 | size = round_up(size, PAGE_SIZE); | |
85 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
86 | if (fp == NULL) | |
87 | return NULL; | |
88 | ||
a91263d5 DB |
89 | kmemcheck_annotate_bitfield(fp, meta); |
90 | ||
09756af4 AS |
91 | aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags); |
92 | if (aux == NULL) { | |
60a3b225 DB |
93 | vfree(fp); |
94 | return NULL; | |
95 | } | |
96 | ||
97 | fp->pages = size / PAGE_SIZE; | |
09756af4 | 98 | fp->aux = aux; |
e9d8afa9 | 99 | fp->aux->prog = fp; |
60a3b225 | 100 | |
74451e66 DB |
101 | INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode); |
102 | ||
60a3b225 DB |
103 | return fp; |
104 | } | |
105 | EXPORT_SYMBOL_GPL(bpf_prog_alloc); | |
106 | ||
107 | struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, | |
108 | gfp_t gfp_extra_flags) | |
109 | { | |
110 | gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | | |
111 | gfp_extra_flags; | |
112 | struct bpf_prog *fp; | |
5ccb071e DB |
113 | u32 pages, delta; |
114 | int ret; | |
60a3b225 DB |
115 | |
116 | BUG_ON(fp_old == NULL); | |
117 | ||
118 | size = round_up(size, PAGE_SIZE); | |
5ccb071e DB |
119 | pages = size / PAGE_SIZE; |
120 | if (pages <= fp_old->pages) | |
60a3b225 DB |
121 | return fp_old; |
122 | ||
5ccb071e DB |
123 | delta = pages - fp_old->pages; |
124 | ret = __bpf_prog_charge(fp_old->aux->user, delta); | |
125 | if (ret) | |
126 | return NULL; | |
127 | ||
60a3b225 | 128 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); |
5ccb071e DB |
129 | if (fp == NULL) { |
130 | __bpf_prog_uncharge(fp_old->aux->user, delta); | |
131 | } else { | |
a91263d5 DB |
132 | kmemcheck_annotate_bitfield(fp, meta); |
133 | ||
60a3b225 | 134 | memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); |
5ccb071e | 135 | fp->pages = pages; |
e9d8afa9 | 136 | fp->aux->prog = fp; |
60a3b225 | 137 | |
09756af4 | 138 | /* We keep fp->aux from fp_old around in the new |
60a3b225 DB |
139 | * reallocated structure. |
140 | */ | |
09756af4 | 141 | fp_old->aux = NULL; |
60a3b225 DB |
142 | __bpf_prog_free(fp_old); |
143 | } | |
144 | ||
145 | return fp; | |
146 | } | |
60a3b225 DB |
147 | |
148 | void __bpf_prog_free(struct bpf_prog *fp) | |
149 | { | |
09756af4 | 150 | kfree(fp->aux); |
60a3b225 DB |
151 | vfree(fp); |
152 | } | |
60a3b225 | 153 | |
f1f7714e | 154 | int bpf_prog_calc_tag(struct bpf_prog *fp) |
7bd509e3 DB |
155 | { |
156 | const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64); | |
f1f7714e DB |
157 | u32 raw_size = bpf_prog_tag_scratch_size(fp); |
158 | u32 digest[SHA_DIGEST_WORDS]; | |
aafe6ae9 | 159 | u32 ws[SHA_WORKSPACE_WORDS]; |
7bd509e3 | 160 | u32 i, bsize, psize, blocks; |
aafe6ae9 | 161 | struct bpf_insn *dst; |
7bd509e3 | 162 | bool was_ld_map; |
aafe6ae9 | 163 | u8 *raw, *todo; |
7bd509e3 DB |
164 | __be32 *result; |
165 | __be64 *bits; | |
166 | ||
aafe6ae9 DB |
167 | raw = vmalloc(raw_size); |
168 | if (!raw) | |
169 | return -ENOMEM; | |
170 | ||
f1f7714e | 171 | sha_init(digest); |
7bd509e3 DB |
172 | memset(ws, 0, sizeof(ws)); |
173 | ||
174 | /* We need to take out the map fd for the digest calculation | |
175 | * since they are unstable from user space side. | |
176 | */ | |
aafe6ae9 | 177 | dst = (void *)raw; |
7bd509e3 DB |
178 | for (i = 0, was_ld_map = false; i < fp->len; i++) { |
179 | dst[i] = fp->insnsi[i]; | |
180 | if (!was_ld_map && | |
181 | dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
182 | dst[i].src_reg == BPF_PSEUDO_MAP_FD) { | |
183 | was_ld_map = true; | |
184 | dst[i].imm = 0; | |
185 | } else if (was_ld_map && | |
186 | dst[i].code == 0 && | |
187 | dst[i].dst_reg == 0 && | |
188 | dst[i].src_reg == 0 && | |
189 | dst[i].off == 0) { | |
190 | was_ld_map = false; | |
191 | dst[i].imm = 0; | |
192 | } else { | |
193 | was_ld_map = false; | |
194 | } | |
195 | } | |
196 | ||
aafe6ae9 DB |
197 | psize = bpf_prog_insn_size(fp); |
198 | memset(&raw[psize], 0, raw_size - psize); | |
7bd509e3 DB |
199 | raw[psize++] = 0x80; |
200 | ||
201 | bsize = round_up(psize, SHA_MESSAGE_BYTES); | |
202 | blocks = bsize / SHA_MESSAGE_BYTES; | |
aafe6ae9 | 203 | todo = raw; |
7bd509e3 DB |
204 | if (bsize - psize >= sizeof(__be64)) { |
205 | bits = (__be64 *)(todo + bsize - sizeof(__be64)); | |
206 | } else { | |
207 | bits = (__be64 *)(todo + bsize + bits_offset); | |
208 | blocks++; | |
209 | } | |
210 | *bits = cpu_to_be64((psize - 1) << 3); | |
211 | ||
212 | while (blocks--) { | |
f1f7714e | 213 | sha_transform(digest, todo, ws); |
7bd509e3 DB |
214 | todo += SHA_MESSAGE_BYTES; |
215 | } | |
216 | ||
f1f7714e | 217 | result = (__force __be32 *)digest; |
7bd509e3 | 218 | for (i = 0; i < SHA_DIGEST_WORDS; i++) |
f1f7714e DB |
219 | result[i] = cpu_to_be32(digest[i]); |
220 | memcpy(fp->tag, result, sizeof(fp->tag)); | |
aafe6ae9 DB |
221 | |
222 | vfree(raw); | |
223 | return 0; | |
7bd509e3 DB |
224 | } |
225 | ||
c237ee5e DB |
226 | static bool bpf_is_jmp_and_has_target(const struct bpf_insn *insn) |
227 | { | |
228 | return BPF_CLASS(insn->code) == BPF_JMP && | |
229 | /* Call and Exit are both special jumps with no | |
230 | * target inside the BPF instruction image. | |
231 | */ | |
232 | BPF_OP(insn->code) != BPF_CALL && | |
233 | BPF_OP(insn->code) != BPF_EXIT; | |
234 | } | |
235 | ||
236 | static void bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta) | |
237 | { | |
238 | struct bpf_insn *insn = prog->insnsi; | |
239 | u32 i, insn_cnt = prog->len; | |
240 | ||
241 | for (i = 0; i < insn_cnt; i++, insn++) { | |
242 | if (!bpf_is_jmp_and_has_target(insn)) | |
243 | continue; | |
244 | ||
245 | /* Adjust offset of jmps if we cross boundaries. */ | |
246 | if (i < pos && i + insn->off + 1 > pos) | |
247 | insn->off += delta; | |
248 | else if (i > pos + delta && i + insn->off + 1 <= pos + delta) | |
249 | insn->off -= delta; | |
250 | } | |
251 | } | |
252 | ||
253 | struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, | |
254 | const struct bpf_insn *patch, u32 len) | |
255 | { | |
256 | u32 insn_adj_cnt, insn_rest, insn_delta = len - 1; | |
257 | struct bpf_prog *prog_adj; | |
258 | ||
259 | /* Since our patchlet doesn't expand the image, we're done. */ | |
260 | if (insn_delta == 0) { | |
261 | memcpy(prog->insnsi + off, patch, sizeof(*patch)); | |
262 | return prog; | |
263 | } | |
264 | ||
265 | insn_adj_cnt = prog->len + insn_delta; | |
266 | ||
267 | /* Several new instructions need to be inserted. Make room | |
268 | * for them. Likely, there's no need for a new allocation as | |
269 | * last page could have large enough tailroom. | |
270 | */ | |
271 | prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt), | |
272 | GFP_USER); | |
273 | if (!prog_adj) | |
274 | return NULL; | |
275 | ||
276 | prog_adj->len = insn_adj_cnt; | |
277 | ||
278 | /* Patching happens in 3 steps: | |
279 | * | |
280 | * 1) Move over tail of insnsi from next instruction onwards, | |
281 | * so we can patch the single target insn with one or more | |
282 | * new ones (patching is always from 1 to n insns, n > 0). | |
283 | * 2) Inject new instructions at the target location. | |
284 | * 3) Adjust branch offsets if necessary. | |
285 | */ | |
286 | insn_rest = insn_adj_cnt - off - len; | |
287 | ||
288 | memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1, | |
289 | sizeof(*patch) * insn_rest); | |
290 | memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len); | |
291 | ||
292 | bpf_adj_branches(prog_adj, off, insn_delta); | |
293 | ||
294 | return prog_adj; | |
295 | } | |
296 | ||
b954d834 | 297 | #ifdef CONFIG_BPF_JIT |
74451e66 DB |
298 | static __always_inline void |
299 | bpf_get_prog_addr_region(const struct bpf_prog *prog, | |
300 | unsigned long *symbol_start, | |
301 | unsigned long *symbol_end) | |
302 | { | |
303 | const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog); | |
304 | unsigned long addr = (unsigned long)hdr; | |
305 | ||
306 | WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog)); | |
307 | ||
308 | *symbol_start = addr; | |
309 | *symbol_end = addr + hdr->pages * PAGE_SIZE; | |
310 | } | |
311 | ||
312 | static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) | |
313 | { | |
314 | BUILD_BUG_ON(sizeof("bpf_prog_") + | |
315 | sizeof(prog->tag) * 2 + 1 > KSYM_NAME_LEN); | |
316 | ||
317 | sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); | |
318 | sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); | |
319 | *sym = 0; | |
320 | } | |
321 | ||
322 | static __always_inline unsigned long | |
323 | bpf_get_prog_addr_start(struct latch_tree_node *n) | |
324 | { | |
325 | unsigned long symbol_start, symbol_end; | |
326 | const struct bpf_prog_aux *aux; | |
327 | ||
328 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
329 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
330 | ||
331 | return symbol_start; | |
332 | } | |
333 | ||
334 | static __always_inline bool bpf_tree_less(struct latch_tree_node *a, | |
335 | struct latch_tree_node *b) | |
336 | { | |
337 | return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b); | |
338 | } | |
339 | ||
340 | static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n) | |
341 | { | |
342 | unsigned long val = (unsigned long)key; | |
343 | unsigned long symbol_start, symbol_end; | |
344 | const struct bpf_prog_aux *aux; | |
345 | ||
346 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
347 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
348 | ||
349 | if (val < symbol_start) | |
350 | return -1; | |
351 | if (val >= symbol_end) | |
352 | return 1; | |
353 | ||
354 | return 0; | |
355 | } | |
356 | ||
357 | static const struct latch_tree_ops bpf_tree_ops = { | |
358 | .less = bpf_tree_less, | |
359 | .comp = bpf_tree_comp, | |
360 | }; | |
361 | ||
362 | static DEFINE_SPINLOCK(bpf_lock); | |
363 | static LIST_HEAD(bpf_kallsyms); | |
364 | static struct latch_tree_root bpf_tree __cacheline_aligned; | |
365 | ||
366 | int bpf_jit_kallsyms __read_mostly; | |
367 | ||
368 | static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux) | |
369 | { | |
370 | WARN_ON_ONCE(!list_empty(&aux->ksym_lnode)); | |
371 | list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms); | |
372 | latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
373 | } | |
374 | ||
375 | static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux) | |
376 | { | |
377 | if (list_empty(&aux->ksym_lnode)) | |
378 | return; | |
379 | ||
380 | latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
381 | list_del_rcu(&aux->ksym_lnode); | |
382 | } | |
383 | ||
384 | static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) | |
385 | { | |
386 | return fp->jited && !bpf_prog_was_classic(fp); | |
387 | } | |
388 | ||
389 | static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) | |
390 | { | |
391 | return list_empty(&fp->aux->ksym_lnode) || | |
392 | fp->aux->ksym_lnode.prev == LIST_POISON2; | |
393 | } | |
394 | ||
395 | void bpf_prog_kallsyms_add(struct bpf_prog *fp) | |
396 | { | |
397 | unsigned long flags; | |
398 | ||
399 | if (!bpf_prog_kallsyms_candidate(fp) || | |
400 | !capable(CAP_SYS_ADMIN)) | |
401 | return; | |
402 | ||
403 | spin_lock_irqsave(&bpf_lock, flags); | |
404 | bpf_prog_ksym_node_add(fp->aux); | |
405 | spin_unlock_irqrestore(&bpf_lock, flags); | |
406 | } | |
407 | ||
408 | void bpf_prog_kallsyms_del(struct bpf_prog *fp) | |
409 | { | |
410 | unsigned long flags; | |
411 | ||
412 | if (!bpf_prog_kallsyms_candidate(fp)) | |
413 | return; | |
414 | ||
415 | spin_lock_irqsave(&bpf_lock, flags); | |
416 | bpf_prog_ksym_node_del(fp->aux); | |
417 | spin_unlock_irqrestore(&bpf_lock, flags); | |
418 | } | |
419 | ||
420 | static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr) | |
421 | { | |
422 | struct latch_tree_node *n; | |
423 | ||
424 | if (!bpf_jit_kallsyms_enabled()) | |
425 | return NULL; | |
426 | ||
427 | n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); | |
428 | return n ? | |
429 | container_of(n, struct bpf_prog_aux, ksym_tnode)->prog : | |
430 | NULL; | |
431 | } | |
432 | ||
433 | const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, | |
434 | unsigned long *off, char *sym) | |
435 | { | |
436 | unsigned long symbol_start, symbol_end; | |
437 | struct bpf_prog *prog; | |
438 | char *ret = NULL; | |
439 | ||
440 | rcu_read_lock(); | |
441 | prog = bpf_prog_kallsyms_find(addr); | |
442 | if (prog) { | |
443 | bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end); | |
444 | bpf_get_prog_name(prog, sym); | |
445 | ||
446 | ret = sym; | |
447 | if (size) | |
448 | *size = symbol_end - symbol_start; | |
449 | if (off) | |
450 | *off = addr - symbol_start; | |
451 | } | |
452 | rcu_read_unlock(); | |
453 | ||
454 | return ret; | |
455 | } | |
456 | ||
457 | bool is_bpf_text_address(unsigned long addr) | |
458 | { | |
459 | bool ret; | |
460 | ||
461 | rcu_read_lock(); | |
462 | ret = bpf_prog_kallsyms_find(addr) != NULL; | |
463 | rcu_read_unlock(); | |
464 | ||
465 | return ret; | |
466 | } | |
467 | ||
468 | int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, | |
469 | char *sym) | |
470 | { | |
471 | unsigned long symbol_start, symbol_end; | |
472 | struct bpf_prog_aux *aux; | |
473 | unsigned int it = 0; | |
474 | int ret = -ERANGE; | |
475 | ||
476 | if (!bpf_jit_kallsyms_enabled()) | |
477 | return ret; | |
478 | ||
479 | rcu_read_lock(); | |
480 | list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) { | |
481 | if (it++ != symnum) | |
482 | continue; | |
483 | ||
484 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
485 | bpf_get_prog_name(aux->prog, sym); | |
486 | ||
487 | *value = symbol_start; | |
488 | *type = BPF_SYM_ELF_TYPE; | |
489 | ||
490 | ret = 0; | |
491 | break; | |
492 | } | |
493 | rcu_read_unlock(); | |
494 | ||
495 | return ret; | |
496 | } | |
497 | ||
738cbe72 DB |
498 | struct bpf_binary_header * |
499 | bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, | |
500 | unsigned int alignment, | |
501 | bpf_jit_fill_hole_t bpf_fill_ill_insns) | |
502 | { | |
503 | struct bpf_binary_header *hdr; | |
504 | unsigned int size, hole, start; | |
505 | ||
506 | /* Most of BPF filters are really small, but if some of them | |
507 | * fill a page, allow at least 128 extra bytes to insert a | |
508 | * random section of illegal instructions. | |
509 | */ | |
510 | size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); | |
511 | hdr = module_alloc(size); | |
512 | if (hdr == NULL) | |
513 | return NULL; | |
514 | ||
515 | /* Fill space with illegal/arch-dep instructions. */ | |
516 | bpf_fill_ill_insns(hdr, size); | |
517 | ||
518 | hdr->pages = size / PAGE_SIZE; | |
519 | hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), | |
520 | PAGE_SIZE - sizeof(*hdr)); | |
b7552e1b | 521 | start = (get_random_int() % hole) & ~(alignment - 1); |
738cbe72 DB |
522 | |
523 | /* Leave a random number of instructions before BPF code. */ | |
524 | *image_ptr = &hdr->image[start]; | |
525 | ||
526 | return hdr; | |
527 | } | |
528 | ||
529 | void bpf_jit_binary_free(struct bpf_binary_header *hdr) | |
530 | { | |
be1f221c | 531 | module_memfree(hdr); |
738cbe72 | 532 | } |
4f3446bb | 533 | |
74451e66 DB |
534 | /* This symbol is only overridden by archs that have different |
535 | * requirements than the usual eBPF JITs, f.e. when they only | |
536 | * implement cBPF JIT, do not set images read-only, etc. | |
537 | */ | |
538 | void __weak bpf_jit_free(struct bpf_prog *fp) | |
539 | { | |
540 | if (fp->jited) { | |
541 | struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp); | |
542 | ||
543 | bpf_jit_binary_unlock_ro(hdr); | |
544 | bpf_jit_binary_free(hdr); | |
545 | ||
546 | WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); | |
547 | } | |
548 | ||
549 | bpf_prog_unlock_free(fp); | |
550 | } | |
551 | ||
4f3446bb DB |
552 | int bpf_jit_harden __read_mostly; |
553 | ||
554 | static int bpf_jit_blind_insn(const struct bpf_insn *from, | |
555 | const struct bpf_insn *aux, | |
556 | struct bpf_insn *to_buff) | |
557 | { | |
558 | struct bpf_insn *to = to_buff; | |
b7552e1b | 559 | u32 imm_rnd = get_random_int(); |
4f3446bb DB |
560 | s16 off; |
561 | ||
562 | BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); | |
563 | BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); | |
564 | ||
565 | if (from->imm == 0 && | |
566 | (from->code == (BPF_ALU | BPF_MOV | BPF_K) || | |
567 | from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { | |
568 | *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg); | |
569 | goto out; | |
570 | } | |
571 | ||
572 | switch (from->code) { | |
573 | case BPF_ALU | BPF_ADD | BPF_K: | |
574 | case BPF_ALU | BPF_SUB | BPF_K: | |
575 | case BPF_ALU | BPF_AND | BPF_K: | |
576 | case BPF_ALU | BPF_OR | BPF_K: | |
577 | case BPF_ALU | BPF_XOR | BPF_K: | |
578 | case BPF_ALU | BPF_MUL | BPF_K: | |
579 | case BPF_ALU | BPF_MOV | BPF_K: | |
580 | case BPF_ALU | BPF_DIV | BPF_K: | |
581 | case BPF_ALU | BPF_MOD | BPF_K: | |
582 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
583 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
584 | *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX); | |
585 | break; | |
586 | ||
587 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
588 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
589 | case BPF_ALU64 | BPF_AND | BPF_K: | |
590 | case BPF_ALU64 | BPF_OR | BPF_K: | |
591 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
592 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
593 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
594 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
595 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
596 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
597 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
598 | *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX); | |
599 | break; | |
600 | ||
601 | case BPF_JMP | BPF_JEQ | BPF_K: | |
602 | case BPF_JMP | BPF_JNE | BPF_K: | |
603 | case BPF_JMP | BPF_JGT | BPF_K: | |
604 | case BPF_JMP | BPF_JGE | BPF_K: | |
605 | case BPF_JMP | BPF_JSGT | BPF_K: | |
606 | case BPF_JMP | BPF_JSGE | BPF_K: | |
607 | case BPF_JMP | BPF_JSET | BPF_K: | |
608 | /* Accommodate for extra offset in case of a backjump. */ | |
609 | off = from->off; | |
610 | if (off < 0) | |
611 | off -= 2; | |
612 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
613 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
614 | *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); | |
615 | break; | |
616 | ||
617 | case BPF_LD | BPF_ABS | BPF_W: | |
618 | case BPF_LD | BPF_ABS | BPF_H: | |
619 | case BPF_LD | BPF_ABS | BPF_B: | |
620 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
621 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
622 | *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); | |
623 | break; | |
624 | ||
625 | case BPF_LD | BPF_IND | BPF_W: | |
626 | case BPF_LD | BPF_IND | BPF_H: | |
627 | case BPF_LD | BPF_IND | BPF_B: | |
628 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
629 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
630 | *to++ = BPF_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg); | |
631 | *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); | |
632 | break; | |
633 | ||
634 | case BPF_LD | BPF_IMM | BPF_DW: | |
635 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); | |
636 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
637 | *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); | |
638 | *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX); | |
639 | break; | |
640 | case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */ | |
641 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm); | |
642 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
643 | *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX); | |
644 | break; | |
645 | ||
646 | case BPF_ST | BPF_MEM | BPF_DW: | |
647 | case BPF_ST | BPF_MEM | BPF_W: | |
648 | case BPF_ST | BPF_MEM | BPF_H: | |
649 | case BPF_ST | BPF_MEM | BPF_B: | |
650 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
651 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
652 | *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); | |
653 | break; | |
654 | } | |
655 | out: | |
656 | return to - to_buff; | |
657 | } | |
658 | ||
659 | static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other, | |
660 | gfp_t gfp_extra_flags) | |
661 | { | |
662 | gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | | |
663 | gfp_extra_flags; | |
664 | struct bpf_prog *fp; | |
665 | ||
666 | fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL); | |
667 | if (fp != NULL) { | |
668 | kmemcheck_annotate_bitfield(fp, meta); | |
669 | ||
670 | /* aux->prog still points to the fp_other one, so | |
671 | * when promoting the clone to the real program, | |
672 | * this still needs to be adapted. | |
673 | */ | |
674 | memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE); | |
675 | } | |
676 | ||
677 | return fp; | |
678 | } | |
679 | ||
680 | static void bpf_prog_clone_free(struct bpf_prog *fp) | |
681 | { | |
682 | /* aux was stolen by the other clone, so we cannot free | |
683 | * it from this path! It will be freed eventually by the | |
684 | * other program on release. | |
685 | * | |
686 | * At this point, we don't need a deferred release since | |
687 | * clone is guaranteed to not be locked. | |
688 | */ | |
689 | fp->aux = NULL; | |
690 | __bpf_prog_free(fp); | |
691 | } | |
692 | ||
693 | void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other) | |
694 | { | |
695 | /* We have to repoint aux->prog to self, as we don't | |
696 | * know whether fp here is the clone or the original. | |
697 | */ | |
698 | fp->aux->prog = fp; | |
699 | bpf_prog_clone_free(fp_other); | |
700 | } | |
701 | ||
702 | struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) | |
703 | { | |
704 | struct bpf_insn insn_buff[16], aux[2]; | |
705 | struct bpf_prog *clone, *tmp; | |
706 | int insn_delta, insn_cnt; | |
707 | struct bpf_insn *insn; | |
708 | int i, rewritten; | |
709 | ||
710 | if (!bpf_jit_blinding_enabled()) | |
711 | return prog; | |
712 | ||
713 | clone = bpf_prog_clone_create(prog, GFP_USER); | |
714 | if (!clone) | |
715 | return ERR_PTR(-ENOMEM); | |
716 | ||
717 | insn_cnt = clone->len; | |
718 | insn = clone->insnsi; | |
719 | ||
720 | for (i = 0; i < insn_cnt; i++, insn++) { | |
721 | /* We temporarily need to hold the original ld64 insn | |
722 | * so that we can still access the first part in the | |
723 | * second blinding run. | |
724 | */ | |
725 | if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
726 | insn[1].code == 0) | |
727 | memcpy(aux, insn, sizeof(aux)); | |
728 | ||
729 | rewritten = bpf_jit_blind_insn(insn, aux, insn_buff); | |
730 | if (!rewritten) | |
731 | continue; | |
732 | ||
733 | tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten); | |
734 | if (!tmp) { | |
735 | /* Patching may have repointed aux->prog during | |
736 | * realloc from the original one, so we need to | |
737 | * fix it up here on error. | |
738 | */ | |
739 | bpf_jit_prog_release_other(prog, clone); | |
740 | return ERR_PTR(-ENOMEM); | |
741 | } | |
742 | ||
743 | clone = tmp; | |
744 | insn_delta = rewritten - 1; | |
745 | ||
746 | /* Walk new program and skip insns we just inserted. */ | |
747 | insn = clone->insnsi + i + insn_delta; | |
748 | insn_cnt += insn_delta; | |
749 | i += insn_delta; | |
750 | } | |
751 | ||
752 | return clone; | |
753 | } | |
b954d834 | 754 | #endif /* CONFIG_BPF_JIT */ |
738cbe72 | 755 | |
f5bffecd AS |
756 | /* Base function for offset calculation. Needs to go into .text section, |
757 | * therefore keeping it non-static as well; will also be used by JITs | |
758 | * anyway later on, so do not let the compiler omit it. | |
759 | */ | |
760 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
761 | { | |
762 | return 0; | |
763 | } | |
4d9c5c53 | 764 | EXPORT_SYMBOL_GPL(__bpf_call_base); |
f5bffecd AS |
765 | |
766 | /** | |
7ae457c1 AS |
767 | * __bpf_prog_run - run eBPF program on a given context |
768 | * @ctx: is the data we are operating on | |
769 | * @insn: is the array of eBPF instructions | |
f5bffecd | 770 | * |
7ae457c1 | 771 | * Decode and execute eBPF instructions. |
f5bffecd | 772 | */ |
7ae457c1 | 773 | static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn) |
f5bffecd AS |
774 | { |
775 | u64 stack[MAX_BPF_STACK / sizeof(u64)]; | |
776 | u64 regs[MAX_BPF_REG], tmp; | |
777 | static const void *jumptable[256] = { | |
778 | [0 ... 255] = &&default_label, | |
779 | /* Now overwrite non-defaults ... */ | |
780 | /* 32 bit ALU operations */ | |
781 | [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X, | |
782 | [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K, | |
783 | [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X, | |
784 | [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K, | |
785 | [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X, | |
786 | [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K, | |
787 | [BPF_ALU | BPF_OR | BPF_X] = &&ALU_OR_X, | |
788 | [BPF_ALU | BPF_OR | BPF_K] = &&ALU_OR_K, | |
789 | [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X, | |
790 | [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K, | |
791 | [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X, | |
792 | [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K, | |
793 | [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X, | |
794 | [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K, | |
795 | [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X, | |
796 | [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K, | |
797 | [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X, | |
798 | [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K, | |
799 | [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X, | |
800 | [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K, | |
801 | [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X, | |
802 | [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K, | |
803 | [BPF_ALU | BPF_NEG] = &&ALU_NEG, | |
804 | [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE, | |
805 | [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE, | |
806 | /* 64 bit ALU operations */ | |
807 | [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X, | |
808 | [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K, | |
809 | [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X, | |
810 | [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K, | |
811 | [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X, | |
812 | [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K, | |
813 | [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X, | |
814 | [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K, | |
815 | [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X, | |
816 | [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K, | |
817 | [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X, | |
818 | [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K, | |
819 | [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X, | |
820 | [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K, | |
821 | [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X, | |
822 | [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K, | |
823 | [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X, | |
824 | [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K, | |
825 | [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X, | |
826 | [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K, | |
827 | [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X, | |
828 | [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K, | |
829 | [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X, | |
830 | [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K, | |
831 | [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG, | |
832 | /* Call instruction */ | |
833 | [BPF_JMP | BPF_CALL] = &&JMP_CALL, | |
04fd61ab | 834 | [BPF_JMP | BPF_CALL | BPF_X] = &&JMP_TAIL_CALL, |
f5bffecd AS |
835 | /* Jumps */ |
836 | [BPF_JMP | BPF_JA] = &&JMP_JA, | |
837 | [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X, | |
838 | [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K, | |
839 | [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X, | |
840 | [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K, | |
841 | [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X, | |
842 | [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K, | |
843 | [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X, | |
844 | [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K, | |
845 | [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X, | |
846 | [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K, | |
847 | [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X, | |
848 | [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K, | |
849 | [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X, | |
850 | [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K, | |
851 | /* Program return */ | |
852 | [BPF_JMP | BPF_EXIT] = &&JMP_EXIT, | |
853 | /* Store instructions */ | |
854 | [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B, | |
855 | [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H, | |
856 | [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W, | |
857 | [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW, | |
858 | [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W, | |
859 | [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW, | |
860 | [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B, | |
861 | [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H, | |
862 | [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W, | |
863 | [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW, | |
864 | /* Load instructions */ | |
865 | [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B, | |
866 | [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H, | |
867 | [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W, | |
868 | [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW, | |
869 | [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W, | |
870 | [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H, | |
871 | [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B, | |
872 | [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W, | |
873 | [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H, | |
874 | [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B, | |
02ab695b | 875 | [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW, |
f5bffecd | 876 | }; |
04fd61ab | 877 | u32 tail_call_cnt = 0; |
f5bffecd AS |
878 | void *ptr; |
879 | int off; | |
880 | ||
881 | #define CONT ({ insn++; goto select_insn; }) | |
882 | #define CONT_JMP ({ insn++; goto select_insn; }) | |
883 | ||
884 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; | |
885 | ARG1 = (u64) (unsigned long) ctx; | |
886 | ||
f5bffecd AS |
887 | select_insn: |
888 | goto *jumptable[insn->code]; | |
889 | ||
890 | /* ALU */ | |
891 | #define ALU(OPCODE, OP) \ | |
892 | ALU64_##OPCODE##_X: \ | |
893 | DST = DST OP SRC; \ | |
894 | CONT; \ | |
895 | ALU_##OPCODE##_X: \ | |
896 | DST = (u32) DST OP (u32) SRC; \ | |
897 | CONT; \ | |
898 | ALU64_##OPCODE##_K: \ | |
899 | DST = DST OP IMM; \ | |
900 | CONT; \ | |
901 | ALU_##OPCODE##_K: \ | |
902 | DST = (u32) DST OP (u32) IMM; \ | |
903 | CONT; | |
904 | ||
905 | ALU(ADD, +) | |
906 | ALU(SUB, -) | |
907 | ALU(AND, &) | |
908 | ALU(OR, |) | |
909 | ALU(LSH, <<) | |
910 | ALU(RSH, >>) | |
911 | ALU(XOR, ^) | |
912 | ALU(MUL, *) | |
913 | #undef ALU | |
914 | ALU_NEG: | |
915 | DST = (u32) -DST; | |
916 | CONT; | |
917 | ALU64_NEG: | |
918 | DST = -DST; | |
919 | CONT; | |
920 | ALU_MOV_X: | |
921 | DST = (u32) SRC; | |
922 | CONT; | |
923 | ALU_MOV_K: | |
924 | DST = (u32) IMM; | |
925 | CONT; | |
926 | ALU64_MOV_X: | |
927 | DST = SRC; | |
928 | CONT; | |
929 | ALU64_MOV_K: | |
930 | DST = IMM; | |
931 | CONT; | |
02ab695b AS |
932 | LD_IMM_DW: |
933 | DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; | |
934 | insn++; | |
935 | CONT; | |
f5bffecd AS |
936 | ALU64_ARSH_X: |
937 | (*(s64 *) &DST) >>= SRC; | |
938 | CONT; | |
939 | ALU64_ARSH_K: | |
940 | (*(s64 *) &DST) >>= IMM; | |
941 | CONT; | |
942 | ALU64_MOD_X: | |
943 | if (unlikely(SRC == 0)) | |
944 | return 0; | |
876a7ae6 AS |
945 | div64_u64_rem(DST, SRC, &tmp); |
946 | DST = tmp; | |
f5bffecd AS |
947 | CONT; |
948 | ALU_MOD_X: | |
949 | if (unlikely(SRC == 0)) | |
950 | return 0; | |
951 | tmp = (u32) DST; | |
952 | DST = do_div(tmp, (u32) SRC); | |
953 | CONT; | |
954 | ALU64_MOD_K: | |
876a7ae6 AS |
955 | div64_u64_rem(DST, IMM, &tmp); |
956 | DST = tmp; | |
f5bffecd AS |
957 | CONT; |
958 | ALU_MOD_K: | |
959 | tmp = (u32) DST; | |
960 | DST = do_div(tmp, (u32) IMM); | |
961 | CONT; | |
962 | ALU64_DIV_X: | |
963 | if (unlikely(SRC == 0)) | |
964 | return 0; | |
876a7ae6 | 965 | DST = div64_u64(DST, SRC); |
f5bffecd AS |
966 | CONT; |
967 | ALU_DIV_X: | |
968 | if (unlikely(SRC == 0)) | |
969 | return 0; | |
970 | tmp = (u32) DST; | |
971 | do_div(tmp, (u32) SRC); | |
972 | DST = (u32) tmp; | |
973 | CONT; | |
974 | ALU64_DIV_K: | |
876a7ae6 | 975 | DST = div64_u64(DST, IMM); |
f5bffecd AS |
976 | CONT; |
977 | ALU_DIV_K: | |
978 | tmp = (u32) DST; | |
979 | do_div(tmp, (u32) IMM); | |
980 | DST = (u32) tmp; | |
981 | CONT; | |
982 | ALU_END_TO_BE: | |
983 | switch (IMM) { | |
984 | case 16: | |
985 | DST = (__force u16) cpu_to_be16(DST); | |
986 | break; | |
987 | case 32: | |
988 | DST = (__force u32) cpu_to_be32(DST); | |
989 | break; | |
990 | case 64: | |
991 | DST = (__force u64) cpu_to_be64(DST); | |
992 | break; | |
993 | } | |
994 | CONT; | |
995 | ALU_END_TO_LE: | |
996 | switch (IMM) { | |
997 | case 16: | |
998 | DST = (__force u16) cpu_to_le16(DST); | |
999 | break; | |
1000 | case 32: | |
1001 | DST = (__force u32) cpu_to_le32(DST); | |
1002 | break; | |
1003 | case 64: | |
1004 | DST = (__force u64) cpu_to_le64(DST); | |
1005 | break; | |
1006 | } | |
1007 | CONT; | |
1008 | ||
1009 | /* CALL */ | |
1010 | JMP_CALL: | |
1011 | /* Function call scratches BPF_R1-BPF_R5 registers, | |
1012 | * preserves BPF_R6-BPF_R9, and stores return value | |
1013 | * into BPF_R0. | |
1014 | */ | |
1015 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, | |
1016 | BPF_R4, BPF_R5); | |
1017 | CONT; | |
1018 | ||
04fd61ab AS |
1019 | JMP_TAIL_CALL: { |
1020 | struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; | |
1021 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
1022 | struct bpf_prog *prog; | |
1023 | u64 index = BPF_R3; | |
1024 | ||
1025 | if (unlikely(index >= array->map.max_entries)) | |
1026 | goto out; | |
04fd61ab AS |
1027 | if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) |
1028 | goto out; | |
1029 | ||
1030 | tail_call_cnt++; | |
1031 | ||
2a36f0b9 | 1032 | prog = READ_ONCE(array->ptrs[index]); |
1ca1cc98 | 1033 | if (!prog) |
04fd61ab AS |
1034 | goto out; |
1035 | ||
c4675f93 DB |
1036 | /* ARG1 at this point is guaranteed to point to CTX from |
1037 | * the verifier side due to the fact that the tail call is | |
1038 | * handeled like a helper, that is, bpf_tail_call_proto, | |
1039 | * where arg1_type is ARG_PTR_TO_CTX. | |
1040 | */ | |
04fd61ab AS |
1041 | insn = prog->insnsi; |
1042 | goto select_insn; | |
1043 | out: | |
1044 | CONT; | |
1045 | } | |
f5bffecd AS |
1046 | /* JMP */ |
1047 | JMP_JA: | |
1048 | insn += insn->off; | |
1049 | CONT; | |
1050 | JMP_JEQ_X: | |
1051 | if (DST == SRC) { | |
1052 | insn += insn->off; | |
1053 | CONT_JMP; | |
1054 | } | |
1055 | CONT; | |
1056 | JMP_JEQ_K: | |
1057 | if (DST == IMM) { | |
1058 | insn += insn->off; | |
1059 | CONT_JMP; | |
1060 | } | |
1061 | CONT; | |
1062 | JMP_JNE_X: | |
1063 | if (DST != SRC) { | |
1064 | insn += insn->off; | |
1065 | CONT_JMP; | |
1066 | } | |
1067 | CONT; | |
1068 | JMP_JNE_K: | |
1069 | if (DST != IMM) { | |
1070 | insn += insn->off; | |
1071 | CONT_JMP; | |
1072 | } | |
1073 | CONT; | |
1074 | JMP_JGT_X: | |
1075 | if (DST > SRC) { | |
1076 | insn += insn->off; | |
1077 | CONT_JMP; | |
1078 | } | |
1079 | CONT; | |
1080 | JMP_JGT_K: | |
1081 | if (DST > IMM) { | |
1082 | insn += insn->off; | |
1083 | CONT_JMP; | |
1084 | } | |
1085 | CONT; | |
1086 | JMP_JGE_X: | |
1087 | if (DST >= SRC) { | |
1088 | insn += insn->off; | |
1089 | CONT_JMP; | |
1090 | } | |
1091 | CONT; | |
1092 | JMP_JGE_K: | |
1093 | if (DST >= IMM) { | |
1094 | insn += insn->off; | |
1095 | CONT_JMP; | |
1096 | } | |
1097 | CONT; | |
1098 | JMP_JSGT_X: | |
1099 | if (((s64) DST) > ((s64) SRC)) { | |
1100 | insn += insn->off; | |
1101 | CONT_JMP; | |
1102 | } | |
1103 | CONT; | |
1104 | JMP_JSGT_K: | |
1105 | if (((s64) DST) > ((s64) IMM)) { | |
1106 | insn += insn->off; | |
1107 | CONT_JMP; | |
1108 | } | |
1109 | CONT; | |
1110 | JMP_JSGE_X: | |
1111 | if (((s64) DST) >= ((s64) SRC)) { | |
1112 | insn += insn->off; | |
1113 | CONT_JMP; | |
1114 | } | |
1115 | CONT; | |
1116 | JMP_JSGE_K: | |
1117 | if (((s64) DST) >= ((s64) IMM)) { | |
1118 | insn += insn->off; | |
1119 | CONT_JMP; | |
1120 | } | |
1121 | CONT; | |
1122 | JMP_JSET_X: | |
1123 | if (DST & SRC) { | |
1124 | insn += insn->off; | |
1125 | CONT_JMP; | |
1126 | } | |
1127 | CONT; | |
1128 | JMP_JSET_K: | |
1129 | if (DST & IMM) { | |
1130 | insn += insn->off; | |
1131 | CONT_JMP; | |
1132 | } | |
1133 | CONT; | |
1134 | JMP_EXIT: | |
1135 | return BPF_R0; | |
1136 | ||
1137 | /* STX and ST and LDX*/ | |
1138 | #define LDST(SIZEOP, SIZE) \ | |
1139 | STX_MEM_##SIZEOP: \ | |
1140 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ | |
1141 | CONT; \ | |
1142 | ST_MEM_##SIZEOP: \ | |
1143 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
1144 | CONT; \ | |
1145 | LDX_MEM_##SIZEOP: \ | |
1146 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
1147 | CONT; | |
1148 | ||
1149 | LDST(B, u8) | |
1150 | LDST(H, u16) | |
1151 | LDST(W, u32) | |
1152 | LDST(DW, u64) | |
1153 | #undef LDST | |
1154 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ | |
1155 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) | |
1156 | (DST + insn->off)); | |
1157 | CONT; | |
1158 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ | |
1159 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) | |
1160 | (DST + insn->off)); | |
1161 | CONT; | |
1162 | LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ | |
1163 | off = IMM; | |
1164 | load_word: | |
96a94cc5 JB |
1165 | /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are only |
1166 | * appearing in the programs where ctx == skb | |
1167 | * (see may_access_skb() in the verifier). All programs | |
1168 | * keep 'ctx' in regs[BPF_REG_CTX] == BPF_R6, | |
1169 | * bpf_convert_filter() saves it in BPF_R6, internal BPF | |
1170 | * verifier will check that BPF_R6 == ctx. | |
f5bffecd AS |
1171 | * |
1172 | * BPF_ABS and BPF_IND are wrappers of function calls, | |
1173 | * so they scratch BPF_R1-BPF_R5 registers, preserve | |
1174 | * BPF_R6-BPF_R9, and store return value into BPF_R0. | |
1175 | * | |
1176 | * Implicit input: | |
1177 | * ctx == skb == BPF_R6 == CTX | |
1178 | * | |
1179 | * Explicit input: | |
1180 | * SRC == any register | |
1181 | * IMM == 32-bit immediate | |
1182 | * | |
1183 | * Output: | |
1184 | * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness | |
1185 | */ | |
1186 | ||
1187 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp); | |
1188 | if (likely(ptr != NULL)) { | |
1189 | BPF_R0 = get_unaligned_be32(ptr); | |
1190 | CONT; | |
1191 | } | |
1192 | ||
1193 | return 0; | |
1194 | LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ | |
1195 | off = IMM; | |
1196 | load_half: | |
1197 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp); | |
1198 | if (likely(ptr != NULL)) { | |
1199 | BPF_R0 = get_unaligned_be16(ptr); | |
1200 | CONT; | |
1201 | } | |
1202 | ||
1203 | return 0; | |
1204 | LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ | |
1205 | off = IMM; | |
1206 | load_byte: | |
1207 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp); | |
1208 | if (likely(ptr != NULL)) { | |
1209 | BPF_R0 = *(u8 *)ptr; | |
1210 | CONT; | |
1211 | } | |
1212 | ||
1213 | return 0; | |
1214 | LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ | |
1215 | off = IMM + SRC; | |
1216 | goto load_word; | |
1217 | LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ | |
1218 | off = IMM + SRC; | |
1219 | goto load_half; | |
1220 | LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ | |
1221 | off = IMM + SRC; | |
1222 | goto load_byte; | |
1223 | ||
1224 | default_label: | |
1225 | /* If we ever reach this, we have a bug somewhere. */ | |
1226 | WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); | |
1227 | return 0; | |
1228 | } | |
39853cc0 | 1229 | STACK_FRAME_NON_STANDARD(__bpf_prog_run); /* jump table */ |
f5bffecd | 1230 | |
3324b584 DB |
1231 | bool bpf_prog_array_compatible(struct bpf_array *array, |
1232 | const struct bpf_prog *fp) | |
04fd61ab | 1233 | { |
3324b584 DB |
1234 | if (!array->owner_prog_type) { |
1235 | /* There's no owner yet where we could check for | |
1236 | * compatibility. | |
1237 | */ | |
04fd61ab AS |
1238 | array->owner_prog_type = fp->type; |
1239 | array->owner_jited = fp->jited; | |
3324b584 DB |
1240 | |
1241 | return true; | |
04fd61ab | 1242 | } |
3324b584 DB |
1243 | |
1244 | return array->owner_prog_type == fp->type && | |
1245 | array->owner_jited == fp->jited; | |
04fd61ab AS |
1246 | } |
1247 | ||
3324b584 | 1248 | static int bpf_check_tail_call(const struct bpf_prog *fp) |
04fd61ab AS |
1249 | { |
1250 | struct bpf_prog_aux *aux = fp->aux; | |
1251 | int i; | |
1252 | ||
1253 | for (i = 0; i < aux->used_map_cnt; i++) { | |
3324b584 | 1254 | struct bpf_map *map = aux->used_maps[i]; |
04fd61ab | 1255 | struct bpf_array *array; |
04fd61ab | 1256 | |
04fd61ab AS |
1257 | if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) |
1258 | continue; | |
3324b584 | 1259 | |
04fd61ab AS |
1260 | array = container_of(map, struct bpf_array, map); |
1261 | if (!bpf_prog_array_compatible(array, fp)) | |
1262 | return -EINVAL; | |
1263 | } | |
1264 | ||
1265 | return 0; | |
1266 | } | |
1267 | ||
f5bffecd | 1268 | /** |
3324b584 | 1269 | * bpf_prog_select_runtime - select exec runtime for BPF program |
7ae457c1 | 1270 | * @fp: bpf_prog populated with internal BPF program |
d1c55ab5 | 1271 | * @err: pointer to error variable |
f5bffecd | 1272 | * |
3324b584 DB |
1273 | * Try to JIT eBPF program, if JIT is not available, use interpreter. |
1274 | * The BPF program will be executed via BPF_PROG_RUN() macro. | |
f5bffecd | 1275 | */ |
d1c55ab5 | 1276 | struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) |
f5bffecd | 1277 | { |
7ae457c1 | 1278 | fp->bpf_func = (void *) __bpf_prog_run; |
f5bffecd | 1279 | |
d1c55ab5 DB |
1280 | /* eBPF JITs can rewrite the program in case constant |
1281 | * blinding is active. However, in case of error during | |
1282 | * blinding, bpf_int_jit_compile() must always return a | |
1283 | * valid program, which in this case would simply not | |
1284 | * be JITed, but falls back to the interpreter. | |
1285 | */ | |
1286 | fp = bpf_int_jit_compile(fp); | |
60a3b225 | 1287 | bpf_prog_lock_ro(fp); |
04fd61ab | 1288 | |
3324b584 DB |
1289 | /* The tail call compatibility check can only be done at |
1290 | * this late stage as we need to determine, if we deal | |
1291 | * with JITed or non JITed program concatenations and not | |
1292 | * all eBPF JITs might immediately support all features. | |
1293 | */ | |
d1c55ab5 DB |
1294 | *err = bpf_check_tail_call(fp); |
1295 | ||
1296 | return fp; | |
f5bffecd | 1297 | } |
7ae457c1 | 1298 | EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
f5bffecd | 1299 | |
60a3b225 DB |
1300 | static void bpf_prog_free_deferred(struct work_struct *work) |
1301 | { | |
09756af4 | 1302 | struct bpf_prog_aux *aux; |
60a3b225 | 1303 | |
09756af4 AS |
1304 | aux = container_of(work, struct bpf_prog_aux, work); |
1305 | bpf_jit_free(aux->prog); | |
60a3b225 DB |
1306 | } |
1307 | ||
1308 | /* Free internal BPF program */ | |
7ae457c1 | 1309 | void bpf_prog_free(struct bpf_prog *fp) |
f5bffecd | 1310 | { |
09756af4 | 1311 | struct bpf_prog_aux *aux = fp->aux; |
60a3b225 | 1312 | |
09756af4 | 1313 | INIT_WORK(&aux->work, bpf_prog_free_deferred); |
09756af4 | 1314 | schedule_work(&aux->work); |
f5bffecd | 1315 | } |
7ae457c1 | 1316 | EXPORT_SYMBOL_GPL(bpf_prog_free); |
f89b7755 | 1317 | |
3ad00405 DB |
1318 | /* RNG for unpriviledged user space with separated state from prandom_u32(). */ |
1319 | static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); | |
1320 | ||
1321 | void bpf_user_rnd_init_once(void) | |
1322 | { | |
1323 | prandom_init_once(&bpf_user_rnd_state); | |
1324 | } | |
1325 | ||
f3694e00 | 1326 | BPF_CALL_0(bpf_user_rnd_u32) |
3ad00405 DB |
1327 | { |
1328 | /* Should someone ever have the rather unwise idea to use some | |
1329 | * of the registers passed into this function, then note that | |
1330 | * this function is called from native eBPF and classic-to-eBPF | |
1331 | * transformations. Register assignments from both sides are | |
1332 | * different, f.e. classic always sets fn(ctx, A, X) here. | |
1333 | */ | |
1334 | struct rnd_state *state; | |
1335 | u32 res; | |
1336 | ||
1337 | state = &get_cpu_var(bpf_user_rnd_state); | |
1338 | res = prandom_u32_state(state); | |
b761fe22 | 1339 | put_cpu_var(bpf_user_rnd_state); |
3ad00405 DB |
1340 | |
1341 | return res; | |
1342 | } | |
1343 | ||
3ba67dab DB |
1344 | /* Weak definitions of helper functions in case we don't have bpf syscall. */ |
1345 | const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; | |
1346 | const struct bpf_func_proto bpf_map_update_elem_proto __weak; | |
1347 | const struct bpf_func_proto bpf_map_delete_elem_proto __weak; | |
1348 | ||
03e69b50 | 1349 | const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; |
c04167ce | 1350 | const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; |
2d0e30c3 | 1351 | const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; |
17ca8cbf | 1352 | const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; |
bd570ff9 | 1353 | |
ffeedafb AS |
1354 | const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; |
1355 | const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; | |
1356 | const struct bpf_func_proto bpf_get_current_comm_proto __weak; | |
bd570ff9 | 1357 | |
0756ea3e AS |
1358 | const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) |
1359 | { | |
1360 | return NULL; | |
1361 | } | |
03e69b50 | 1362 | |
555c8a86 DB |
1363 | u64 __weak |
1364 | bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, | |
1365 | void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) | |
bd570ff9 | 1366 | { |
555c8a86 | 1367 | return -ENOTSUPP; |
bd570ff9 DB |
1368 | } |
1369 | ||
3324b584 DB |
1370 | /* Always built-in helper functions. */ |
1371 | const struct bpf_func_proto bpf_tail_call_proto = { | |
1372 | .func = NULL, | |
1373 | .gpl_only = false, | |
1374 | .ret_type = RET_VOID, | |
1375 | .arg1_type = ARG_PTR_TO_CTX, | |
1376 | .arg2_type = ARG_CONST_MAP_PTR, | |
1377 | .arg3_type = ARG_ANYTHING, | |
1378 | }; | |
1379 | ||
9383191d DB |
1380 | /* Stub for JITs that only support cBPF. eBPF programs are interpreted. |
1381 | * It is encouraged to implement bpf_int_jit_compile() instead, so that | |
1382 | * eBPF and implicitly also cBPF can get JITed! | |
1383 | */ | |
d1c55ab5 | 1384 | struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog) |
3324b584 | 1385 | { |
d1c55ab5 | 1386 | return prog; |
3324b584 DB |
1387 | } |
1388 | ||
9383191d DB |
1389 | /* Stub for JITs that support eBPF. All cBPF code gets transformed into |
1390 | * eBPF by the kernel and is later compiled by bpf_int_jit_compile(). | |
1391 | */ | |
1392 | void __weak bpf_jit_compile(struct bpf_prog *prog) | |
1393 | { | |
1394 | } | |
1395 | ||
17bedab2 | 1396 | bool __weak bpf_helper_changes_pkt_data(void *func) |
969bf05e AS |
1397 | { |
1398 | return false; | |
1399 | } | |
1400 | ||
f89b7755 AS |
1401 | /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call |
1402 | * skb_copy_bits(), so provide a weak definition of it for NET-less config. | |
1403 | */ | |
1404 | int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, | |
1405 | int len) | |
1406 | { | |
1407 | return -EFAULT; | |
1408 | } | |
a67edbf4 DB |
1409 | |
1410 | /* All definitions of tracepoints related to BPF. */ | |
1411 | #define CREATE_TRACE_POINTS | |
1412 | #include <linux/bpf_trace.h> | |
1413 | ||
1414 | EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); | |
1415 | ||
1416 | EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_get_type); | |
1417 | EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_put_rcu); |