Commit | Line | Data |
---|---|---|
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 | { | |
19809c2d | 79 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
09756af4 | 80 | struct bpf_prog_aux *aux; |
60a3b225 DB |
81 | struct bpf_prog *fp; |
82 | ||
83 | size = round_up(size, PAGE_SIZE); | |
84 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
85 | if (fp == NULL) | |
86 | return NULL; | |
87 | ||
a91263d5 DB |
88 | kmemcheck_annotate_bitfield(fp, meta); |
89 | ||
09756af4 AS |
90 | aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags); |
91 | if (aux == NULL) { | |
60a3b225 DB |
92 | vfree(fp); |
93 | return NULL; | |
94 | } | |
95 | ||
96 | fp->pages = size / PAGE_SIZE; | |
09756af4 | 97 | fp->aux = aux; |
e9d8afa9 | 98 | fp->aux->prog = fp; |
60a3b225 | 99 | |
74451e66 DB |
100 | INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode); |
101 | ||
60a3b225 DB |
102 | return fp; |
103 | } | |
104 | EXPORT_SYMBOL_GPL(bpf_prog_alloc); | |
105 | ||
106 | struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, | |
107 | gfp_t gfp_extra_flags) | |
108 | { | |
19809c2d | 109 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
60a3b225 | 110 | struct bpf_prog *fp; |
5ccb071e DB |
111 | u32 pages, delta; |
112 | int ret; | |
60a3b225 DB |
113 | |
114 | BUG_ON(fp_old == NULL); | |
115 | ||
116 | size = round_up(size, PAGE_SIZE); | |
5ccb071e DB |
117 | pages = size / PAGE_SIZE; |
118 | if (pages <= fp_old->pages) | |
60a3b225 DB |
119 | return fp_old; |
120 | ||
5ccb071e DB |
121 | delta = pages - fp_old->pages; |
122 | ret = __bpf_prog_charge(fp_old->aux->user, delta); | |
123 | if (ret) | |
124 | return NULL; | |
125 | ||
60a3b225 | 126 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); |
5ccb071e DB |
127 | if (fp == NULL) { |
128 | __bpf_prog_uncharge(fp_old->aux->user, delta); | |
129 | } else { | |
a91263d5 DB |
130 | kmemcheck_annotate_bitfield(fp, meta); |
131 | ||
60a3b225 | 132 | memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); |
5ccb071e | 133 | fp->pages = pages; |
e9d8afa9 | 134 | fp->aux->prog = fp; |
60a3b225 | 135 | |
09756af4 | 136 | /* We keep fp->aux from fp_old around in the new |
60a3b225 DB |
137 | * reallocated structure. |
138 | */ | |
09756af4 | 139 | fp_old->aux = NULL; |
60a3b225 DB |
140 | __bpf_prog_free(fp_old); |
141 | } | |
142 | ||
143 | return fp; | |
144 | } | |
60a3b225 DB |
145 | |
146 | void __bpf_prog_free(struct bpf_prog *fp) | |
147 | { | |
09756af4 | 148 | kfree(fp->aux); |
60a3b225 DB |
149 | vfree(fp); |
150 | } | |
60a3b225 | 151 | |
f1f7714e | 152 | int bpf_prog_calc_tag(struct bpf_prog *fp) |
7bd509e3 DB |
153 | { |
154 | const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64); | |
f1f7714e DB |
155 | u32 raw_size = bpf_prog_tag_scratch_size(fp); |
156 | u32 digest[SHA_DIGEST_WORDS]; | |
aafe6ae9 | 157 | u32 ws[SHA_WORKSPACE_WORDS]; |
7bd509e3 | 158 | u32 i, bsize, psize, blocks; |
aafe6ae9 | 159 | struct bpf_insn *dst; |
7bd509e3 | 160 | bool was_ld_map; |
aafe6ae9 | 161 | u8 *raw, *todo; |
7bd509e3 DB |
162 | __be32 *result; |
163 | __be64 *bits; | |
164 | ||
aafe6ae9 DB |
165 | raw = vmalloc(raw_size); |
166 | if (!raw) | |
167 | return -ENOMEM; | |
168 | ||
f1f7714e | 169 | sha_init(digest); |
7bd509e3 DB |
170 | memset(ws, 0, sizeof(ws)); |
171 | ||
172 | /* We need to take out the map fd for the digest calculation | |
173 | * since they are unstable from user space side. | |
174 | */ | |
aafe6ae9 | 175 | dst = (void *)raw; |
7bd509e3 DB |
176 | for (i = 0, was_ld_map = false; i < fp->len; i++) { |
177 | dst[i] = fp->insnsi[i]; | |
178 | if (!was_ld_map && | |
179 | dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
180 | dst[i].src_reg == BPF_PSEUDO_MAP_FD) { | |
181 | was_ld_map = true; | |
182 | dst[i].imm = 0; | |
183 | } else if (was_ld_map && | |
184 | dst[i].code == 0 && | |
185 | dst[i].dst_reg == 0 && | |
186 | dst[i].src_reg == 0 && | |
187 | dst[i].off == 0) { | |
188 | was_ld_map = false; | |
189 | dst[i].imm = 0; | |
190 | } else { | |
191 | was_ld_map = false; | |
192 | } | |
193 | } | |
194 | ||
aafe6ae9 DB |
195 | psize = bpf_prog_insn_size(fp); |
196 | memset(&raw[psize], 0, raw_size - psize); | |
7bd509e3 DB |
197 | raw[psize++] = 0x80; |
198 | ||
199 | bsize = round_up(psize, SHA_MESSAGE_BYTES); | |
200 | blocks = bsize / SHA_MESSAGE_BYTES; | |
aafe6ae9 | 201 | todo = raw; |
7bd509e3 DB |
202 | if (bsize - psize >= sizeof(__be64)) { |
203 | bits = (__be64 *)(todo + bsize - sizeof(__be64)); | |
204 | } else { | |
205 | bits = (__be64 *)(todo + bsize + bits_offset); | |
206 | blocks++; | |
207 | } | |
208 | *bits = cpu_to_be64((psize - 1) << 3); | |
209 | ||
210 | while (blocks--) { | |
f1f7714e | 211 | sha_transform(digest, todo, ws); |
7bd509e3 DB |
212 | todo += SHA_MESSAGE_BYTES; |
213 | } | |
214 | ||
f1f7714e | 215 | result = (__force __be32 *)digest; |
7bd509e3 | 216 | for (i = 0; i < SHA_DIGEST_WORDS; i++) |
f1f7714e DB |
217 | result[i] = cpu_to_be32(digest[i]); |
218 | memcpy(fp->tag, result, sizeof(fp->tag)); | |
aafe6ae9 DB |
219 | |
220 | vfree(raw); | |
221 | return 0; | |
7bd509e3 DB |
222 | } |
223 | ||
c237ee5e DB |
224 | static bool bpf_is_jmp_and_has_target(const struct bpf_insn *insn) |
225 | { | |
226 | return BPF_CLASS(insn->code) == BPF_JMP && | |
227 | /* Call and Exit are both special jumps with no | |
228 | * target inside the BPF instruction image. | |
229 | */ | |
230 | BPF_OP(insn->code) != BPF_CALL && | |
231 | BPF_OP(insn->code) != BPF_EXIT; | |
232 | } | |
233 | ||
234 | static void bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta) | |
235 | { | |
236 | struct bpf_insn *insn = prog->insnsi; | |
237 | u32 i, insn_cnt = prog->len; | |
238 | ||
239 | for (i = 0; i < insn_cnt; i++, insn++) { | |
240 | if (!bpf_is_jmp_and_has_target(insn)) | |
241 | continue; | |
242 | ||
243 | /* Adjust offset of jmps if we cross boundaries. */ | |
244 | if (i < pos && i + insn->off + 1 > pos) | |
245 | insn->off += delta; | |
246 | else if (i > pos + delta && i + insn->off + 1 <= pos + delta) | |
247 | insn->off -= delta; | |
248 | } | |
249 | } | |
250 | ||
251 | struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, | |
252 | const struct bpf_insn *patch, u32 len) | |
253 | { | |
254 | u32 insn_adj_cnt, insn_rest, insn_delta = len - 1; | |
255 | struct bpf_prog *prog_adj; | |
256 | ||
257 | /* Since our patchlet doesn't expand the image, we're done. */ | |
258 | if (insn_delta == 0) { | |
259 | memcpy(prog->insnsi + off, patch, sizeof(*patch)); | |
260 | return prog; | |
261 | } | |
262 | ||
263 | insn_adj_cnt = prog->len + insn_delta; | |
264 | ||
265 | /* Several new instructions need to be inserted. Make room | |
266 | * for them. Likely, there's no need for a new allocation as | |
267 | * last page could have large enough tailroom. | |
268 | */ | |
269 | prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt), | |
270 | GFP_USER); | |
271 | if (!prog_adj) | |
272 | return NULL; | |
273 | ||
274 | prog_adj->len = insn_adj_cnt; | |
275 | ||
276 | /* Patching happens in 3 steps: | |
277 | * | |
278 | * 1) Move over tail of insnsi from next instruction onwards, | |
279 | * so we can patch the single target insn with one or more | |
280 | * new ones (patching is always from 1 to n insns, n > 0). | |
281 | * 2) Inject new instructions at the target location. | |
282 | * 3) Adjust branch offsets if necessary. | |
283 | */ | |
284 | insn_rest = insn_adj_cnt - off - len; | |
285 | ||
286 | memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1, | |
287 | sizeof(*patch) * insn_rest); | |
288 | memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len); | |
289 | ||
290 | bpf_adj_branches(prog_adj, off, insn_delta); | |
291 | ||
292 | return prog_adj; | |
293 | } | |
294 | ||
b954d834 | 295 | #ifdef CONFIG_BPF_JIT |
74451e66 DB |
296 | static __always_inline void |
297 | bpf_get_prog_addr_region(const struct bpf_prog *prog, | |
298 | unsigned long *symbol_start, | |
299 | unsigned long *symbol_end) | |
300 | { | |
301 | const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog); | |
302 | unsigned long addr = (unsigned long)hdr; | |
303 | ||
304 | WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog)); | |
305 | ||
306 | *symbol_start = addr; | |
307 | *symbol_end = addr + hdr->pages * PAGE_SIZE; | |
308 | } | |
309 | ||
310 | static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) | |
311 | { | |
368211fb MKL |
312 | const char *end = sym + KSYM_NAME_LEN; |
313 | ||
74451e66 | 314 | BUILD_BUG_ON(sizeof("bpf_prog_") + |
368211fb MKL |
315 | sizeof(prog->tag) * 2 + |
316 | /* name has been null terminated. | |
317 | * We should need +1 for the '_' preceding | |
318 | * the name. However, the null character | |
319 | * is double counted between the name and the | |
320 | * sizeof("bpf_prog_") above, so we omit | |
321 | * the +1 here. | |
322 | */ | |
323 | sizeof(prog->aux->name) > KSYM_NAME_LEN); | |
74451e66 DB |
324 | |
325 | sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); | |
326 | sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); | |
368211fb MKL |
327 | if (prog->aux->name[0]) |
328 | snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); | |
329 | else | |
330 | *sym = 0; | |
74451e66 DB |
331 | } |
332 | ||
333 | static __always_inline unsigned long | |
334 | bpf_get_prog_addr_start(struct latch_tree_node *n) | |
335 | { | |
336 | unsigned long symbol_start, symbol_end; | |
337 | const struct bpf_prog_aux *aux; | |
338 | ||
339 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
340 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
341 | ||
342 | return symbol_start; | |
343 | } | |
344 | ||
345 | static __always_inline bool bpf_tree_less(struct latch_tree_node *a, | |
346 | struct latch_tree_node *b) | |
347 | { | |
348 | return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b); | |
349 | } | |
350 | ||
351 | static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n) | |
352 | { | |
353 | unsigned long val = (unsigned long)key; | |
354 | unsigned long symbol_start, symbol_end; | |
355 | const struct bpf_prog_aux *aux; | |
356 | ||
357 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
358 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
359 | ||
360 | if (val < symbol_start) | |
361 | return -1; | |
362 | if (val >= symbol_end) | |
363 | return 1; | |
364 | ||
365 | return 0; | |
366 | } | |
367 | ||
368 | static const struct latch_tree_ops bpf_tree_ops = { | |
369 | .less = bpf_tree_less, | |
370 | .comp = bpf_tree_comp, | |
371 | }; | |
372 | ||
373 | static DEFINE_SPINLOCK(bpf_lock); | |
374 | static LIST_HEAD(bpf_kallsyms); | |
375 | static struct latch_tree_root bpf_tree __cacheline_aligned; | |
376 | ||
377 | int bpf_jit_kallsyms __read_mostly; | |
378 | ||
379 | static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux) | |
380 | { | |
381 | WARN_ON_ONCE(!list_empty(&aux->ksym_lnode)); | |
382 | list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms); | |
383 | latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
384 | } | |
385 | ||
386 | static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux) | |
387 | { | |
388 | if (list_empty(&aux->ksym_lnode)) | |
389 | return; | |
390 | ||
391 | latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
392 | list_del_rcu(&aux->ksym_lnode); | |
393 | } | |
394 | ||
395 | static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) | |
396 | { | |
397 | return fp->jited && !bpf_prog_was_classic(fp); | |
398 | } | |
399 | ||
400 | static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) | |
401 | { | |
402 | return list_empty(&fp->aux->ksym_lnode) || | |
403 | fp->aux->ksym_lnode.prev == LIST_POISON2; | |
404 | } | |
405 | ||
406 | void bpf_prog_kallsyms_add(struct bpf_prog *fp) | |
407 | { | |
74451e66 DB |
408 | if (!bpf_prog_kallsyms_candidate(fp) || |
409 | !capable(CAP_SYS_ADMIN)) | |
410 | return; | |
411 | ||
d24f7c7f | 412 | spin_lock_bh(&bpf_lock); |
74451e66 | 413 | bpf_prog_ksym_node_add(fp->aux); |
d24f7c7f | 414 | spin_unlock_bh(&bpf_lock); |
74451e66 DB |
415 | } |
416 | ||
417 | void bpf_prog_kallsyms_del(struct bpf_prog *fp) | |
418 | { | |
74451e66 DB |
419 | if (!bpf_prog_kallsyms_candidate(fp)) |
420 | return; | |
421 | ||
d24f7c7f | 422 | spin_lock_bh(&bpf_lock); |
74451e66 | 423 | bpf_prog_ksym_node_del(fp->aux); |
d24f7c7f | 424 | spin_unlock_bh(&bpf_lock); |
74451e66 DB |
425 | } |
426 | ||
427 | static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr) | |
428 | { | |
429 | struct latch_tree_node *n; | |
430 | ||
431 | if (!bpf_jit_kallsyms_enabled()) | |
432 | return NULL; | |
433 | ||
434 | n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); | |
435 | return n ? | |
436 | container_of(n, struct bpf_prog_aux, ksym_tnode)->prog : | |
437 | NULL; | |
438 | } | |
439 | ||
440 | const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, | |
441 | unsigned long *off, char *sym) | |
442 | { | |
443 | unsigned long symbol_start, symbol_end; | |
444 | struct bpf_prog *prog; | |
445 | char *ret = NULL; | |
446 | ||
447 | rcu_read_lock(); | |
448 | prog = bpf_prog_kallsyms_find(addr); | |
449 | if (prog) { | |
450 | bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end); | |
451 | bpf_get_prog_name(prog, sym); | |
452 | ||
453 | ret = sym; | |
454 | if (size) | |
455 | *size = symbol_end - symbol_start; | |
456 | if (off) | |
457 | *off = addr - symbol_start; | |
458 | } | |
459 | rcu_read_unlock(); | |
460 | ||
461 | return ret; | |
462 | } | |
463 | ||
464 | bool is_bpf_text_address(unsigned long addr) | |
465 | { | |
466 | bool ret; | |
467 | ||
468 | rcu_read_lock(); | |
469 | ret = bpf_prog_kallsyms_find(addr) != NULL; | |
470 | rcu_read_unlock(); | |
471 | ||
472 | return ret; | |
473 | } | |
474 | ||
475 | int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, | |
476 | char *sym) | |
477 | { | |
478 | unsigned long symbol_start, symbol_end; | |
479 | struct bpf_prog_aux *aux; | |
480 | unsigned int it = 0; | |
481 | int ret = -ERANGE; | |
482 | ||
483 | if (!bpf_jit_kallsyms_enabled()) | |
484 | return ret; | |
485 | ||
486 | rcu_read_lock(); | |
487 | list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) { | |
488 | if (it++ != symnum) | |
489 | continue; | |
490 | ||
491 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
492 | bpf_get_prog_name(aux->prog, sym); | |
493 | ||
494 | *value = symbol_start; | |
495 | *type = BPF_SYM_ELF_TYPE; | |
496 | ||
497 | ret = 0; | |
498 | break; | |
499 | } | |
500 | rcu_read_unlock(); | |
501 | ||
502 | return ret; | |
503 | } | |
504 | ||
738cbe72 DB |
505 | struct bpf_binary_header * |
506 | bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, | |
507 | unsigned int alignment, | |
508 | bpf_jit_fill_hole_t bpf_fill_ill_insns) | |
509 | { | |
510 | struct bpf_binary_header *hdr; | |
511 | unsigned int size, hole, start; | |
512 | ||
513 | /* Most of BPF filters are really small, but if some of them | |
514 | * fill a page, allow at least 128 extra bytes to insert a | |
515 | * random section of illegal instructions. | |
516 | */ | |
517 | size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); | |
518 | hdr = module_alloc(size); | |
519 | if (hdr == NULL) | |
520 | return NULL; | |
521 | ||
522 | /* Fill space with illegal/arch-dep instructions. */ | |
523 | bpf_fill_ill_insns(hdr, size); | |
524 | ||
525 | hdr->pages = size / PAGE_SIZE; | |
526 | hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), | |
527 | PAGE_SIZE - sizeof(*hdr)); | |
b7552e1b | 528 | start = (get_random_int() % hole) & ~(alignment - 1); |
738cbe72 DB |
529 | |
530 | /* Leave a random number of instructions before BPF code. */ | |
531 | *image_ptr = &hdr->image[start]; | |
532 | ||
533 | return hdr; | |
534 | } | |
535 | ||
536 | void bpf_jit_binary_free(struct bpf_binary_header *hdr) | |
537 | { | |
be1f221c | 538 | module_memfree(hdr); |
738cbe72 | 539 | } |
4f3446bb | 540 | |
74451e66 DB |
541 | /* This symbol is only overridden by archs that have different |
542 | * requirements than the usual eBPF JITs, f.e. when they only | |
543 | * implement cBPF JIT, do not set images read-only, etc. | |
544 | */ | |
545 | void __weak bpf_jit_free(struct bpf_prog *fp) | |
546 | { | |
547 | if (fp->jited) { | |
548 | struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp); | |
549 | ||
550 | bpf_jit_binary_unlock_ro(hdr); | |
551 | bpf_jit_binary_free(hdr); | |
552 | ||
553 | WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); | |
554 | } | |
555 | ||
556 | bpf_prog_unlock_free(fp); | |
557 | } | |
558 | ||
4f3446bb DB |
559 | int bpf_jit_harden __read_mostly; |
560 | ||
561 | static int bpf_jit_blind_insn(const struct bpf_insn *from, | |
562 | const struct bpf_insn *aux, | |
563 | struct bpf_insn *to_buff) | |
564 | { | |
565 | struct bpf_insn *to = to_buff; | |
b7552e1b | 566 | u32 imm_rnd = get_random_int(); |
4f3446bb DB |
567 | s16 off; |
568 | ||
569 | BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); | |
570 | BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); | |
571 | ||
572 | if (from->imm == 0 && | |
573 | (from->code == (BPF_ALU | BPF_MOV | BPF_K) || | |
574 | from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { | |
575 | *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg); | |
576 | goto out; | |
577 | } | |
578 | ||
579 | switch (from->code) { | |
580 | case BPF_ALU | BPF_ADD | BPF_K: | |
581 | case BPF_ALU | BPF_SUB | BPF_K: | |
582 | case BPF_ALU | BPF_AND | BPF_K: | |
583 | case BPF_ALU | BPF_OR | BPF_K: | |
584 | case BPF_ALU | BPF_XOR | BPF_K: | |
585 | case BPF_ALU | BPF_MUL | BPF_K: | |
586 | case BPF_ALU | BPF_MOV | BPF_K: | |
587 | case BPF_ALU | BPF_DIV | BPF_K: | |
588 | case BPF_ALU | BPF_MOD | BPF_K: | |
589 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
590 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
591 | *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX); | |
592 | break; | |
593 | ||
594 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
595 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
596 | case BPF_ALU64 | BPF_AND | BPF_K: | |
597 | case BPF_ALU64 | BPF_OR | BPF_K: | |
598 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
599 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
600 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
601 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
602 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
603 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
604 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
605 | *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX); | |
606 | break; | |
607 | ||
608 | case BPF_JMP | BPF_JEQ | BPF_K: | |
609 | case BPF_JMP | BPF_JNE | BPF_K: | |
610 | case BPF_JMP | BPF_JGT | BPF_K: | |
92b31a9a | 611 | case BPF_JMP | BPF_JLT | BPF_K: |
4f3446bb | 612 | case BPF_JMP | BPF_JGE | BPF_K: |
92b31a9a | 613 | case BPF_JMP | BPF_JLE | BPF_K: |
4f3446bb | 614 | case BPF_JMP | BPF_JSGT | BPF_K: |
92b31a9a | 615 | case BPF_JMP | BPF_JSLT | BPF_K: |
4f3446bb | 616 | case BPF_JMP | BPF_JSGE | BPF_K: |
92b31a9a | 617 | case BPF_JMP | BPF_JSLE | BPF_K: |
4f3446bb DB |
618 | case BPF_JMP | BPF_JSET | BPF_K: |
619 | /* Accommodate for extra offset in case of a backjump. */ | |
620 | off = from->off; | |
621 | if (off < 0) | |
622 | off -= 2; | |
623 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
624 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
625 | *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); | |
626 | break; | |
627 | ||
628 | case BPF_LD | BPF_ABS | BPF_W: | |
629 | case BPF_LD | BPF_ABS | BPF_H: | |
630 | case BPF_LD | BPF_ABS | BPF_B: | |
631 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
632 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
633 | *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); | |
634 | break; | |
635 | ||
636 | case BPF_LD | BPF_IND | BPF_W: | |
637 | case BPF_LD | BPF_IND | BPF_H: | |
638 | case BPF_LD | BPF_IND | BPF_B: | |
639 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
640 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
641 | *to++ = BPF_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg); | |
642 | *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); | |
643 | break; | |
644 | ||
645 | case BPF_LD | BPF_IMM | BPF_DW: | |
646 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); | |
647 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
648 | *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); | |
649 | *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX); | |
650 | break; | |
651 | case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */ | |
652 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm); | |
653 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
654 | *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX); | |
655 | break; | |
656 | ||
657 | case BPF_ST | BPF_MEM | BPF_DW: | |
658 | case BPF_ST | BPF_MEM | BPF_W: | |
659 | case BPF_ST | BPF_MEM | BPF_H: | |
660 | case BPF_ST | BPF_MEM | BPF_B: | |
661 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
662 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
663 | *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); | |
664 | break; | |
665 | } | |
666 | out: | |
667 | return to - to_buff; | |
668 | } | |
669 | ||
670 | static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other, | |
671 | gfp_t gfp_extra_flags) | |
672 | { | |
19809c2d | 673 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
4f3446bb DB |
674 | struct bpf_prog *fp; |
675 | ||
676 | fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL); | |
677 | if (fp != NULL) { | |
678 | kmemcheck_annotate_bitfield(fp, meta); | |
679 | ||
680 | /* aux->prog still points to the fp_other one, so | |
681 | * when promoting the clone to the real program, | |
682 | * this still needs to be adapted. | |
683 | */ | |
684 | memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE); | |
685 | } | |
686 | ||
687 | return fp; | |
688 | } | |
689 | ||
690 | static void bpf_prog_clone_free(struct bpf_prog *fp) | |
691 | { | |
692 | /* aux was stolen by the other clone, so we cannot free | |
693 | * it from this path! It will be freed eventually by the | |
694 | * other program on release. | |
695 | * | |
696 | * At this point, we don't need a deferred release since | |
697 | * clone is guaranteed to not be locked. | |
698 | */ | |
699 | fp->aux = NULL; | |
700 | __bpf_prog_free(fp); | |
701 | } | |
702 | ||
703 | void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other) | |
704 | { | |
705 | /* We have to repoint aux->prog to self, as we don't | |
706 | * know whether fp here is the clone or the original. | |
707 | */ | |
708 | fp->aux->prog = fp; | |
709 | bpf_prog_clone_free(fp_other); | |
710 | } | |
711 | ||
712 | struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) | |
713 | { | |
714 | struct bpf_insn insn_buff[16], aux[2]; | |
715 | struct bpf_prog *clone, *tmp; | |
716 | int insn_delta, insn_cnt; | |
717 | struct bpf_insn *insn; | |
718 | int i, rewritten; | |
719 | ||
720 | if (!bpf_jit_blinding_enabled()) | |
721 | return prog; | |
722 | ||
723 | clone = bpf_prog_clone_create(prog, GFP_USER); | |
724 | if (!clone) | |
725 | return ERR_PTR(-ENOMEM); | |
726 | ||
727 | insn_cnt = clone->len; | |
728 | insn = clone->insnsi; | |
729 | ||
730 | for (i = 0; i < insn_cnt; i++, insn++) { | |
731 | /* We temporarily need to hold the original ld64 insn | |
732 | * so that we can still access the first part in the | |
733 | * second blinding run. | |
734 | */ | |
735 | if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
736 | insn[1].code == 0) | |
737 | memcpy(aux, insn, sizeof(aux)); | |
738 | ||
739 | rewritten = bpf_jit_blind_insn(insn, aux, insn_buff); | |
740 | if (!rewritten) | |
741 | continue; | |
742 | ||
743 | tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten); | |
744 | if (!tmp) { | |
745 | /* Patching may have repointed aux->prog during | |
746 | * realloc from the original one, so we need to | |
747 | * fix it up here on error. | |
748 | */ | |
749 | bpf_jit_prog_release_other(prog, clone); | |
750 | return ERR_PTR(-ENOMEM); | |
751 | } | |
752 | ||
753 | clone = tmp; | |
754 | insn_delta = rewritten - 1; | |
755 | ||
756 | /* Walk new program and skip insns we just inserted. */ | |
757 | insn = clone->insnsi + i + insn_delta; | |
758 | insn_cnt += insn_delta; | |
759 | i += insn_delta; | |
760 | } | |
761 | ||
762 | return clone; | |
763 | } | |
b954d834 | 764 | #endif /* CONFIG_BPF_JIT */ |
738cbe72 | 765 | |
f5bffecd AS |
766 | /* Base function for offset calculation. Needs to go into .text section, |
767 | * therefore keeping it non-static as well; will also be used by JITs | |
768 | * anyway later on, so do not let the compiler omit it. | |
769 | */ | |
770 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
771 | { | |
772 | return 0; | |
773 | } | |
4d9c5c53 | 774 | EXPORT_SYMBOL_GPL(__bpf_call_base); |
f5bffecd AS |
775 | |
776 | /** | |
7ae457c1 AS |
777 | * __bpf_prog_run - run eBPF program on a given context |
778 | * @ctx: is the data we are operating on | |
779 | * @insn: is the array of eBPF instructions | |
f5bffecd | 780 | * |
7ae457c1 | 781 | * Decode and execute eBPF instructions. |
f5bffecd | 782 | */ |
f696b8f4 AS |
783 | static unsigned int ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, |
784 | u64 *stack) | |
f5bffecd | 785 | { |
f696b8f4 | 786 | u64 tmp; |
f5bffecd AS |
787 | static const void *jumptable[256] = { |
788 | [0 ... 255] = &&default_label, | |
789 | /* Now overwrite non-defaults ... */ | |
790 | /* 32 bit ALU operations */ | |
791 | [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X, | |
792 | [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K, | |
793 | [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X, | |
794 | [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K, | |
795 | [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X, | |
796 | [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K, | |
797 | [BPF_ALU | BPF_OR | BPF_X] = &&ALU_OR_X, | |
798 | [BPF_ALU | BPF_OR | BPF_K] = &&ALU_OR_K, | |
799 | [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X, | |
800 | [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K, | |
801 | [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X, | |
802 | [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K, | |
803 | [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X, | |
804 | [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K, | |
805 | [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X, | |
806 | [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K, | |
807 | [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X, | |
808 | [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K, | |
809 | [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X, | |
810 | [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K, | |
811 | [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X, | |
812 | [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K, | |
813 | [BPF_ALU | BPF_NEG] = &&ALU_NEG, | |
814 | [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE, | |
815 | [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE, | |
816 | /* 64 bit ALU operations */ | |
817 | [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X, | |
818 | [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K, | |
819 | [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X, | |
820 | [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K, | |
821 | [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X, | |
822 | [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K, | |
823 | [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X, | |
824 | [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K, | |
825 | [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X, | |
826 | [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K, | |
827 | [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X, | |
828 | [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K, | |
829 | [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X, | |
830 | [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K, | |
831 | [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X, | |
832 | [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K, | |
833 | [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X, | |
834 | [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K, | |
835 | [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X, | |
836 | [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K, | |
837 | [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X, | |
838 | [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K, | |
839 | [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X, | |
840 | [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K, | |
841 | [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG, | |
842 | /* Call instruction */ | |
843 | [BPF_JMP | BPF_CALL] = &&JMP_CALL, | |
71189fa9 | 844 | [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, |
f5bffecd AS |
845 | /* Jumps */ |
846 | [BPF_JMP | BPF_JA] = &&JMP_JA, | |
847 | [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X, | |
848 | [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K, | |
849 | [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X, | |
850 | [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K, | |
851 | [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X, | |
852 | [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K, | |
92b31a9a DB |
853 | [BPF_JMP | BPF_JLT | BPF_X] = &&JMP_JLT_X, |
854 | [BPF_JMP | BPF_JLT | BPF_K] = &&JMP_JLT_K, | |
f5bffecd AS |
855 | [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X, |
856 | [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K, | |
92b31a9a DB |
857 | [BPF_JMP | BPF_JLE | BPF_X] = &&JMP_JLE_X, |
858 | [BPF_JMP | BPF_JLE | BPF_K] = &&JMP_JLE_K, | |
f5bffecd AS |
859 | [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X, |
860 | [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K, | |
92b31a9a DB |
861 | [BPF_JMP | BPF_JSLT | BPF_X] = &&JMP_JSLT_X, |
862 | [BPF_JMP | BPF_JSLT | BPF_K] = &&JMP_JSLT_K, | |
f5bffecd AS |
863 | [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X, |
864 | [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K, | |
92b31a9a DB |
865 | [BPF_JMP | BPF_JSLE | BPF_X] = &&JMP_JSLE_X, |
866 | [BPF_JMP | BPF_JSLE | BPF_K] = &&JMP_JSLE_K, | |
f5bffecd AS |
867 | [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X, |
868 | [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K, | |
869 | /* Program return */ | |
870 | [BPF_JMP | BPF_EXIT] = &&JMP_EXIT, | |
871 | /* Store instructions */ | |
872 | [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B, | |
873 | [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H, | |
874 | [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W, | |
875 | [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW, | |
876 | [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W, | |
877 | [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW, | |
878 | [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B, | |
879 | [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H, | |
880 | [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W, | |
881 | [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW, | |
882 | /* Load instructions */ | |
883 | [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B, | |
884 | [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H, | |
885 | [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W, | |
886 | [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW, | |
887 | [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W, | |
888 | [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H, | |
889 | [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B, | |
890 | [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W, | |
891 | [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H, | |
892 | [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B, | |
02ab695b | 893 | [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW, |
f5bffecd | 894 | }; |
04fd61ab | 895 | u32 tail_call_cnt = 0; |
f5bffecd AS |
896 | void *ptr; |
897 | int off; | |
898 | ||
899 | #define CONT ({ insn++; goto select_insn; }) | |
900 | #define CONT_JMP ({ insn++; goto select_insn; }) | |
901 | ||
f5bffecd AS |
902 | select_insn: |
903 | goto *jumptable[insn->code]; | |
904 | ||
905 | /* ALU */ | |
906 | #define ALU(OPCODE, OP) \ | |
907 | ALU64_##OPCODE##_X: \ | |
908 | DST = DST OP SRC; \ | |
909 | CONT; \ | |
910 | ALU_##OPCODE##_X: \ | |
911 | DST = (u32) DST OP (u32) SRC; \ | |
912 | CONT; \ | |
913 | ALU64_##OPCODE##_K: \ | |
914 | DST = DST OP IMM; \ | |
915 | CONT; \ | |
916 | ALU_##OPCODE##_K: \ | |
917 | DST = (u32) DST OP (u32) IMM; \ | |
918 | CONT; | |
919 | ||
920 | ALU(ADD, +) | |
921 | ALU(SUB, -) | |
922 | ALU(AND, &) | |
923 | ALU(OR, |) | |
924 | ALU(LSH, <<) | |
925 | ALU(RSH, >>) | |
926 | ALU(XOR, ^) | |
927 | ALU(MUL, *) | |
928 | #undef ALU | |
929 | ALU_NEG: | |
930 | DST = (u32) -DST; | |
931 | CONT; | |
932 | ALU64_NEG: | |
933 | DST = -DST; | |
934 | CONT; | |
935 | ALU_MOV_X: | |
936 | DST = (u32) SRC; | |
937 | CONT; | |
938 | ALU_MOV_K: | |
939 | DST = (u32) IMM; | |
940 | CONT; | |
941 | ALU64_MOV_X: | |
942 | DST = SRC; | |
943 | CONT; | |
944 | ALU64_MOV_K: | |
945 | DST = IMM; | |
946 | CONT; | |
02ab695b AS |
947 | LD_IMM_DW: |
948 | DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; | |
949 | insn++; | |
950 | CONT; | |
f5bffecd AS |
951 | ALU64_ARSH_X: |
952 | (*(s64 *) &DST) >>= SRC; | |
953 | CONT; | |
954 | ALU64_ARSH_K: | |
955 | (*(s64 *) &DST) >>= IMM; | |
956 | CONT; | |
957 | ALU64_MOD_X: | |
958 | if (unlikely(SRC == 0)) | |
959 | return 0; | |
876a7ae6 AS |
960 | div64_u64_rem(DST, SRC, &tmp); |
961 | DST = tmp; | |
f5bffecd AS |
962 | CONT; |
963 | ALU_MOD_X: | |
964 | if (unlikely(SRC == 0)) | |
965 | return 0; | |
966 | tmp = (u32) DST; | |
967 | DST = do_div(tmp, (u32) SRC); | |
968 | CONT; | |
969 | ALU64_MOD_K: | |
876a7ae6 AS |
970 | div64_u64_rem(DST, IMM, &tmp); |
971 | DST = tmp; | |
f5bffecd AS |
972 | CONT; |
973 | ALU_MOD_K: | |
974 | tmp = (u32) DST; | |
975 | DST = do_div(tmp, (u32) IMM); | |
976 | CONT; | |
977 | ALU64_DIV_X: | |
978 | if (unlikely(SRC == 0)) | |
979 | return 0; | |
876a7ae6 | 980 | DST = div64_u64(DST, SRC); |
f5bffecd AS |
981 | CONT; |
982 | ALU_DIV_X: | |
983 | if (unlikely(SRC == 0)) | |
984 | return 0; | |
985 | tmp = (u32) DST; | |
986 | do_div(tmp, (u32) SRC); | |
987 | DST = (u32) tmp; | |
988 | CONT; | |
989 | ALU64_DIV_K: | |
876a7ae6 | 990 | DST = div64_u64(DST, IMM); |
f5bffecd AS |
991 | CONT; |
992 | ALU_DIV_K: | |
993 | tmp = (u32) DST; | |
994 | do_div(tmp, (u32) IMM); | |
995 | DST = (u32) tmp; | |
996 | CONT; | |
997 | ALU_END_TO_BE: | |
998 | switch (IMM) { | |
999 | case 16: | |
1000 | DST = (__force u16) cpu_to_be16(DST); | |
1001 | break; | |
1002 | case 32: | |
1003 | DST = (__force u32) cpu_to_be32(DST); | |
1004 | break; | |
1005 | case 64: | |
1006 | DST = (__force u64) cpu_to_be64(DST); | |
1007 | break; | |
1008 | } | |
1009 | CONT; | |
1010 | ALU_END_TO_LE: | |
1011 | switch (IMM) { | |
1012 | case 16: | |
1013 | DST = (__force u16) cpu_to_le16(DST); | |
1014 | break; | |
1015 | case 32: | |
1016 | DST = (__force u32) cpu_to_le32(DST); | |
1017 | break; | |
1018 | case 64: | |
1019 | DST = (__force u64) cpu_to_le64(DST); | |
1020 | break; | |
1021 | } | |
1022 | CONT; | |
1023 | ||
1024 | /* CALL */ | |
1025 | JMP_CALL: | |
1026 | /* Function call scratches BPF_R1-BPF_R5 registers, | |
1027 | * preserves BPF_R6-BPF_R9, and stores return value | |
1028 | * into BPF_R0. | |
1029 | */ | |
1030 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, | |
1031 | BPF_R4, BPF_R5); | |
1032 | CONT; | |
1033 | ||
04fd61ab AS |
1034 | JMP_TAIL_CALL: { |
1035 | struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; | |
1036 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
1037 | struct bpf_prog *prog; | |
90caccdd | 1038 | u32 index = BPF_R3; |
04fd61ab AS |
1039 | |
1040 | if (unlikely(index >= array->map.max_entries)) | |
1041 | goto out; | |
04fd61ab AS |
1042 | if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) |
1043 | goto out; | |
1044 | ||
1045 | tail_call_cnt++; | |
1046 | ||
2a36f0b9 | 1047 | prog = READ_ONCE(array->ptrs[index]); |
1ca1cc98 | 1048 | if (!prog) |
04fd61ab AS |
1049 | goto out; |
1050 | ||
c4675f93 DB |
1051 | /* ARG1 at this point is guaranteed to point to CTX from |
1052 | * the verifier side due to the fact that the tail call is | |
1053 | * handeled like a helper, that is, bpf_tail_call_proto, | |
1054 | * where arg1_type is ARG_PTR_TO_CTX. | |
1055 | */ | |
04fd61ab AS |
1056 | insn = prog->insnsi; |
1057 | goto select_insn; | |
1058 | out: | |
1059 | CONT; | |
1060 | } | |
f5bffecd AS |
1061 | /* JMP */ |
1062 | JMP_JA: | |
1063 | insn += insn->off; | |
1064 | CONT; | |
1065 | JMP_JEQ_X: | |
1066 | if (DST == SRC) { | |
1067 | insn += insn->off; | |
1068 | CONT_JMP; | |
1069 | } | |
1070 | CONT; | |
1071 | JMP_JEQ_K: | |
1072 | if (DST == IMM) { | |
1073 | insn += insn->off; | |
1074 | CONT_JMP; | |
1075 | } | |
1076 | CONT; | |
1077 | JMP_JNE_X: | |
1078 | if (DST != SRC) { | |
1079 | insn += insn->off; | |
1080 | CONT_JMP; | |
1081 | } | |
1082 | CONT; | |
1083 | JMP_JNE_K: | |
1084 | if (DST != IMM) { | |
1085 | insn += insn->off; | |
1086 | CONT_JMP; | |
1087 | } | |
1088 | CONT; | |
1089 | JMP_JGT_X: | |
1090 | if (DST > SRC) { | |
1091 | insn += insn->off; | |
1092 | CONT_JMP; | |
1093 | } | |
1094 | CONT; | |
1095 | JMP_JGT_K: | |
1096 | if (DST > IMM) { | |
1097 | insn += insn->off; | |
1098 | CONT_JMP; | |
1099 | } | |
1100 | CONT; | |
92b31a9a DB |
1101 | JMP_JLT_X: |
1102 | if (DST < SRC) { | |
1103 | insn += insn->off; | |
1104 | CONT_JMP; | |
1105 | } | |
1106 | CONT; | |
1107 | JMP_JLT_K: | |
1108 | if (DST < IMM) { | |
1109 | insn += insn->off; | |
1110 | CONT_JMP; | |
1111 | } | |
1112 | CONT; | |
f5bffecd AS |
1113 | JMP_JGE_X: |
1114 | if (DST >= SRC) { | |
1115 | insn += insn->off; | |
1116 | CONT_JMP; | |
1117 | } | |
1118 | CONT; | |
1119 | JMP_JGE_K: | |
1120 | if (DST >= IMM) { | |
1121 | insn += insn->off; | |
1122 | CONT_JMP; | |
1123 | } | |
1124 | CONT; | |
92b31a9a DB |
1125 | JMP_JLE_X: |
1126 | if (DST <= SRC) { | |
1127 | insn += insn->off; | |
1128 | CONT_JMP; | |
1129 | } | |
1130 | CONT; | |
1131 | JMP_JLE_K: | |
1132 | if (DST <= IMM) { | |
1133 | insn += insn->off; | |
1134 | CONT_JMP; | |
1135 | } | |
1136 | CONT; | |
f5bffecd AS |
1137 | JMP_JSGT_X: |
1138 | if (((s64) DST) > ((s64) SRC)) { | |
1139 | insn += insn->off; | |
1140 | CONT_JMP; | |
1141 | } | |
1142 | CONT; | |
1143 | JMP_JSGT_K: | |
1144 | if (((s64) DST) > ((s64) IMM)) { | |
1145 | insn += insn->off; | |
1146 | CONT_JMP; | |
1147 | } | |
1148 | CONT; | |
92b31a9a DB |
1149 | JMP_JSLT_X: |
1150 | if (((s64) DST) < ((s64) SRC)) { | |
1151 | insn += insn->off; | |
1152 | CONT_JMP; | |
1153 | } | |
1154 | CONT; | |
1155 | JMP_JSLT_K: | |
1156 | if (((s64) DST) < ((s64) IMM)) { | |
1157 | insn += insn->off; | |
1158 | CONT_JMP; | |
1159 | } | |
1160 | CONT; | |
f5bffecd AS |
1161 | JMP_JSGE_X: |
1162 | if (((s64) DST) >= ((s64) SRC)) { | |
1163 | insn += insn->off; | |
1164 | CONT_JMP; | |
1165 | } | |
1166 | CONT; | |
1167 | JMP_JSGE_K: | |
1168 | if (((s64) DST) >= ((s64) IMM)) { | |
1169 | insn += insn->off; | |
1170 | CONT_JMP; | |
1171 | } | |
1172 | CONT; | |
92b31a9a DB |
1173 | JMP_JSLE_X: |
1174 | if (((s64) DST) <= ((s64) SRC)) { | |
1175 | insn += insn->off; | |
1176 | CONT_JMP; | |
1177 | } | |
1178 | CONT; | |
1179 | JMP_JSLE_K: | |
1180 | if (((s64) DST) <= ((s64) IMM)) { | |
1181 | insn += insn->off; | |
1182 | CONT_JMP; | |
1183 | } | |
1184 | CONT; | |
f5bffecd AS |
1185 | JMP_JSET_X: |
1186 | if (DST & SRC) { | |
1187 | insn += insn->off; | |
1188 | CONT_JMP; | |
1189 | } | |
1190 | CONT; | |
1191 | JMP_JSET_K: | |
1192 | if (DST & IMM) { | |
1193 | insn += insn->off; | |
1194 | CONT_JMP; | |
1195 | } | |
1196 | CONT; | |
1197 | JMP_EXIT: | |
1198 | return BPF_R0; | |
1199 | ||
1200 | /* STX and ST and LDX*/ | |
1201 | #define LDST(SIZEOP, SIZE) \ | |
1202 | STX_MEM_##SIZEOP: \ | |
1203 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ | |
1204 | CONT; \ | |
1205 | ST_MEM_##SIZEOP: \ | |
1206 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
1207 | CONT; \ | |
1208 | LDX_MEM_##SIZEOP: \ | |
1209 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
1210 | CONT; | |
1211 | ||
1212 | LDST(B, u8) | |
1213 | LDST(H, u16) | |
1214 | LDST(W, u32) | |
1215 | LDST(DW, u64) | |
1216 | #undef LDST | |
1217 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ | |
1218 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) | |
1219 | (DST + insn->off)); | |
1220 | CONT; | |
1221 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ | |
1222 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) | |
1223 | (DST + insn->off)); | |
1224 | CONT; | |
1225 | LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ | |
1226 | off = IMM; | |
1227 | load_word: | |
96a94cc5 JB |
1228 | /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are only |
1229 | * appearing in the programs where ctx == skb | |
1230 | * (see may_access_skb() in the verifier). All programs | |
1231 | * keep 'ctx' in regs[BPF_REG_CTX] == BPF_R6, | |
1232 | * bpf_convert_filter() saves it in BPF_R6, internal BPF | |
1233 | * verifier will check that BPF_R6 == ctx. | |
f5bffecd AS |
1234 | * |
1235 | * BPF_ABS and BPF_IND are wrappers of function calls, | |
1236 | * so they scratch BPF_R1-BPF_R5 registers, preserve | |
1237 | * BPF_R6-BPF_R9, and store return value into BPF_R0. | |
1238 | * | |
1239 | * Implicit input: | |
1240 | * ctx == skb == BPF_R6 == CTX | |
1241 | * | |
1242 | * Explicit input: | |
1243 | * SRC == any register | |
1244 | * IMM == 32-bit immediate | |
1245 | * | |
1246 | * Output: | |
1247 | * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness | |
1248 | */ | |
1249 | ||
1250 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp); | |
1251 | if (likely(ptr != NULL)) { | |
1252 | BPF_R0 = get_unaligned_be32(ptr); | |
1253 | CONT; | |
1254 | } | |
1255 | ||
1256 | return 0; | |
1257 | LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ | |
1258 | off = IMM; | |
1259 | load_half: | |
1260 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp); | |
1261 | if (likely(ptr != NULL)) { | |
1262 | BPF_R0 = get_unaligned_be16(ptr); | |
1263 | CONT; | |
1264 | } | |
1265 | ||
1266 | return 0; | |
1267 | LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ | |
1268 | off = IMM; | |
1269 | load_byte: | |
1270 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp); | |
1271 | if (likely(ptr != NULL)) { | |
1272 | BPF_R0 = *(u8 *)ptr; | |
1273 | CONT; | |
1274 | } | |
1275 | ||
1276 | return 0; | |
1277 | LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ | |
1278 | off = IMM + SRC; | |
1279 | goto load_word; | |
1280 | LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ | |
1281 | off = IMM + SRC; | |
1282 | goto load_half; | |
1283 | LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ | |
1284 | off = IMM + SRC; | |
1285 | goto load_byte; | |
1286 | ||
1287 | default_label: | |
1288 | /* If we ever reach this, we have a bug somewhere. */ | |
1289 | WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); | |
1290 | return 0; | |
1291 | } | |
f696b8f4 AS |
1292 | STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */ |
1293 | ||
b870aa90 AS |
1294 | #define PROG_NAME(stack_size) __bpf_prog_run##stack_size |
1295 | #define DEFINE_BPF_PROG_RUN(stack_size) \ | |
1296 | static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ | |
1297 | { \ | |
1298 | u64 stack[stack_size / sizeof(u64)]; \ | |
1299 | u64 regs[MAX_BPF_REG]; \ | |
1300 | \ | |
1301 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ | |
1302 | ARG1 = (u64) (unsigned long) ctx; \ | |
1303 | return ___bpf_prog_run(regs, insn, stack); \ | |
f696b8f4 | 1304 | } |
f5bffecd | 1305 | |
b870aa90 AS |
1306 | #define EVAL1(FN, X) FN(X) |
1307 | #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y) | |
1308 | #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y) | |
1309 | #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y) | |
1310 | #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y) | |
1311 | #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y) | |
1312 | ||
1313 | EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192); | |
1314 | EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384); | |
1315 | EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512); | |
1316 | ||
1317 | #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size), | |
1318 | ||
1319 | static unsigned int (*interpreters[])(const void *ctx, | |
1320 | const struct bpf_insn *insn) = { | |
1321 | EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) | |
1322 | EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) | |
1323 | EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) | |
1324 | }; | |
1325 | ||
3324b584 DB |
1326 | bool bpf_prog_array_compatible(struct bpf_array *array, |
1327 | const struct bpf_prog *fp) | |
04fd61ab | 1328 | { |
3324b584 DB |
1329 | if (!array->owner_prog_type) { |
1330 | /* There's no owner yet where we could check for | |
1331 | * compatibility. | |
1332 | */ | |
04fd61ab AS |
1333 | array->owner_prog_type = fp->type; |
1334 | array->owner_jited = fp->jited; | |
3324b584 DB |
1335 | |
1336 | return true; | |
04fd61ab | 1337 | } |
3324b584 DB |
1338 | |
1339 | return array->owner_prog_type == fp->type && | |
1340 | array->owner_jited == fp->jited; | |
04fd61ab AS |
1341 | } |
1342 | ||
3324b584 | 1343 | static int bpf_check_tail_call(const struct bpf_prog *fp) |
04fd61ab AS |
1344 | { |
1345 | struct bpf_prog_aux *aux = fp->aux; | |
1346 | int i; | |
1347 | ||
1348 | for (i = 0; i < aux->used_map_cnt; i++) { | |
3324b584 | 1349 | struct bpf_map *map = aux->used_maps[i]; |
04fd61ab | 1350 | struct bpf_array *array; |
04fd61ab | 1351 | |
04fd61ab AS |
1352 | if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) |
1353 | continue; | |
3324b584 | 1354 | |
04fd61ab AS |
1355 | array = container_of(map, struct bpf_array, map); |
1356 | if (!bpf_prog_array_compatible(array, fp)) | |
1357 | return -EINVAL; | |
1358 | } | |
1359 | ||
1360 | return 0; | |
1361 | } | |
1362 | ||
f5bffecd | 1363 | /** |
3324b584 | 1364 | * bpf_prog_select_runtime - select exec runtime for BPF program |
7ae457c1 | 1365 | * @fp: bpf_prog populated with internal BPF program |
d1c55ab5 | 1366 | * @err: pointer to error variable |
f5bffecd | 1367 | * |
3324b584 DB |
1368 | * Try to JIT eBPF program, if JIT is not available, use interpreter. |
1369 | * The BPF program will be executed via BPF_PROG_RUN() macro. | |
f5bffecd | 1370 | */ |
d1c55ab5 | 1371 | struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) |
f5bffecd | 1372 | { |
8007e40a MKL |
1373 | u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1); |
1374 | ||
1375 | fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1]; | |
f5bffecd | 1376 | |
d1c55ab5 DB |
1377 | /* eBPF JITs can rewrite the program in case constant |
1378 | * blinding is active. However, in case of error during | |
1379 | * blinding, bpf_int_jit_compile() must always return a | |
1380 | * valid program, which in this case would simply not | |
1381 | * be JITed, but falls back to the interpreter. | |
1382 | */ | |
1383 | fp = bpf_int_jit_compile(fp); | |
60a3b225 | 1384 | bpf_prog_lock_ro(fp); |
04fd61ab | 1385 | |
3324b584 DB |
1386 | /* The tail call compatibility check can only be done at |
1387 | * this late stage as we need to determine, if we deal | |
1388 | * with JITed or non JITed program concatenations and not | |
1389 | * all eBPF JITs might immediately support all features. | |
1390 | */ | |
d1c55ab5 DB |
1391 | *err = bpf_check_tail_call(fp); |
1392 | ||
1393 | return fp; | |
f5bffecd | 1394 | } |
7ae457c1 | 1395 | EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
f5bffecd | 1396 | |
e87c6bc3 YS |
1397 | static unsigned int __bpf_prog_ret1(const void *ctx, |
1398 | const struct bpf_insn *insn) | |
1399 | { | |
1400 | return 1; | |
1401 | } | |
1402 | ||
1403 | static struct bpf_prog_dummy { | |
1404 | struct bpf_prog prog; | |
1405 | } dummy_bpf_prog = { | |
1406 | .prog = { | |
1407 | .bpf_func = __bpf_prog_ret1, | |
1408 | }, | |
1409 | }; | |
1410 | ||
324bda9e AS |
1411 | /* to avoid allocating empty bpf_prog_array for cgroups that |
1412 | * don't have bpf program attached use one global 'empty_prog_array' | |
1413 | * It will not be modified the caller of bpf_prog_array_alloc() | |
1414 | * (since caller requested prog_cnt == 0) | |
1415 | * that pointer should be 'freed' by bpf_prog_array_free() | |
1416 | */ | |
1417 | static struct { | |
1418 | struct bpf_prog_array hdr; | |
1419 | struct bpf_prog *null_prog; | |
1420 | } empty_prog_array = { | |
1421 | .null_prog = NULL, | |
1422 | }; | |
1423 | ||
1424 | struct bpf_prog_array __rcu *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags) | |
1425 | { | |
1426 | if (prog_cnt) | |
1427 | return kzalloc(sizeof(struct bpf_prog_array) + | |
1428 | sizeof(struct bpf_prog *) * (prog_cnt + 1), | |
1429 | flags); | |
1430 | ||
1431 | return &empty_prog_array.hdr; | |
1432 | } | |
1433 | ||
1434 | void bpf_prog_array_free(struct bpf_prog_array __rcu *progs) | |
1435 | { | |
1436 | if (!progs || | |
1437 | progs == (struct bpf_prog_array __rcu *)&empty_prog_array.hdr) | |
1438 | return; | |
1439 | kfree_rcu(progs, rcu); | |
1440 | } | |
1441 | ||
468e2f64 AS |
1442 | int bpf_prog_array_length(struct bpf_prog_array __rcu *progs) |
1443 | { | |
1444 | struct bpf_prog **prog; | |
1445 | u32 cnt = 0; | |
1446 | ||
1447 | rcu_read_lock(); | |
1448 | prog = rcu_dereference(progs)->progs; | |
1449 | for (; *prog; prog++) | |
1450 | cnt++; | |
1451 | rcu_read_unlock(); | |
1452 | return cnt; | |
1453 | } | |
1454 | ||
1455 | int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs, | |
1456 | __u32 __user *prog_ids, u32 cnt) | |
1457 | { | |
1458 | struct bpf_prog **prog; | |
1459 | u32 i = 0, id; | |
1460 | ||
1461 | rcu_read_lock(); | |
1462 | prog = rcu_dereference(progs)->progs; | |
1463 | for (; *prog; prog++) { | |
1464 | id = (*prog)->aux->id; | |
1465 | if (copy_to_user(prog_ids + i, &id, sizeof(id))) { | |
1466 | rcu_read_unlock(); | |
1467 | return -EFAULT; | |
1468 | } | |
1469 | if (++i == cnt) { | |
1470 | prog++; | |
1471 | break; | |
1472 | } | |
1473 | } | |
1474 | rcu_read_unlock(); | |
1475 | if (*prog) | |
1476 | return -ENOSPC; | |
1477 | return 0; | |
1478 | } | |
1479 | ||
e87c6bc3 YS |
1480 | void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *progs, |
1481 | struct bpf_prog *old_prog) | |
1482 | { | |
1483 | struct bpf_prog **prog = progs->progs; | |
1484 | ||
1485 | for (; *prog; prog++) | |
1486 | if (*prog == old_prog) { | |
1487 | WRITE_ONCE(*prog, &dummy_bpf_prog.prog); | |
1488 | break; | |
1489 | } | |
1490 | } | |
1491 | ||
1492 | int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, | |
1493 | struct bpf_prog *exclude_prog, | |
1494 | struct bpf_prog *include_prog, | |
1495 | struct bpf_prog_array **new_array) | |
1496 | { | |
1497 | int new_prog_cnt, carry_prog_cnt = 0; | |
1498 | struct bpf_prog **existing_prog; | |
1499 | struct bpf_prog_array *array; | |
1500 | int new_prog_idx = 0; | |
1501 | ||
1502 | /* Figure out how many existing progs we need to carry over to | |
1503 | * the new array. | |
1504 | */ | |
1505 | if (old_array) { | |
1506 | existing_prog = old_array->progs; | |
1507 | for (; *existing_prog; existing_prog++) { | |
1508 | if (*existing_prog != exclude_prog && | |
1509 | *existing_prog != &dummy_bpf_prog.prog) | |
1510 | carry_prog_cnt++; | |
1511 | if (*existing_prog == include_prog) | |
1512 | return -EEXIST; | |
1513 | } | |
1514 | } | |
1515 | ||
1516 | /* How many progs (not NULL) will be in the new array? */ | |
1517 | new_prog_cnt = carry_prog_cnt; | |
1518 | if (include_prog) | |
1519 | new_prog_cnt += 1; | |
1520 | ||
1521 | /* Do we have any prog (not NULL) in the new array? */ | |
1522 | if (!new_prog_cnt) { | |
1523 | *new_array = NULL; | |
1524 | return 0; | |
1525 | } | |
1526 | ||
1527 | /* +1 as the end of prog_array is marked with NULL */ | |
1528 | array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); | |
1529 | if (!array) | |
1530 | return -ENOMEM; | |
1531 | ||
1532 | /* Fill in the new prog array */ | |
1533 | if (carry_prog_cnt) { | |
1534 | existing_prog = old_array->progs; | |
1535 | for (; *existing_prog; existing_prog++) | |
1536 | if (*existing_prog != exclude_prog && | |
1537 | *existing_prog != &dummy_bpf_prog.prog) | |
1538 | array->progs[new_prog_idx++] = *existing_prog; | |
1539 | } | |
1540 | if (include_prog) | |
1541 | array->progs[new_prog_idx++] = include_prog; | |
1542 | array->progs[new_prog_idx] = NULL; | |
1543 | *new_array = array; | |
1544 | return 0; | |
1545 | } | |
1546 | ||
60a3b225 DB |
1547 | static void bpf_prog_free_deferred(struct work_struct *work) |
1548 | { | |
09756af4 | 1549 | struct bpf_prog_aux *aux; |
60a3b225 | 1550 | |
09756af4 AS |
1551 | aux = container_of(work, struct bpf_prog_aux, work); |
1552 | bpf_jit_free(aux->prog); | |
60a3b225 DB |
1553 | } |
1554 | ||
1555 | /* Free internal BPF program */ | |
7ae457c1 | 1556 | void bpf_prog_free(struct bpf_prog *fp) |
f5bffecd | 1557 | { |
09756af4 | 1558 | struct bpf_prog_aux *aux = fp->aux; |
60a3b225 | 1559 | |
09756af4 | 1560 | INIT_WORK(&aux->work, bpf_prog_free_deferred); |
09756af4 | 1561 | schedule_work(&aux->work); |
f5bffecd | 1562 | } |
7ae457c1 | 1563 | EXPORT_SYMBOL_GPL(bpf_prog_free); |
f89b7755 | 1564 | |
3ad00405 DB |
1565 | /* RNG for unpriviledged user space with separated state from prandom_u32(). */ |
1566 | static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); | |
1567 | ||
1568 | void bpf_user_rnd_init_once(void) | |
1569 | { | |
1570 | prandom_init_once(&bpf_user_rnd_state); | |
1571 | } | |
1572 | ||
f3694e00 | 1573 | BPF_CALL_0(bpf_user_rnd_u32) |
3ad00405 DB |
1574 | { |
1575 | /* Should someone ever have the rather unwise idea to use some | |
1576 | * of the registers passed into this function, then note that | |
1577 | * this function is called from native eBPF and classic-to-eBPF | |
1578 | * transformations. Register assignments from both sides are | |
1579 | * different, f.e. classic always sets fn(ctx, A, X) here. | |
1580 | */ | |
1581 | struct rnd_state *state; | |
1582 | u32 res; | |
1583 | ||
1584 | state = &get_cpu_var(bpf_user_rnd_state); | |
1585 | res = prandom_u32_state(state); | |
b761fe22 | 1586 | put_cpu_var(bpf_user_rnd_state); |
3ad00405 DB |
1587 | |
1588 | return res; | |
1589 | } | |
1590 | ||
3ba67dab DB |
1591 | /* Weak definitions of helper functions in case we don't have bpf syscall. */ |
1592 | const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; | |
1593 | const struct bpf_func_proto bpf_map_update_elem_proto __weak; | |
1594 | const struct bpf_func_proto bpf_map_delete_elem_proto __weak; | |
1595 | ||
03e69b50 | 1596 | const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; |
c04167ce | 1597 | const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; |
2d0e30c3 | 1598 | const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; |
17ca8cbf | 1599 | const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; |
bd570ff9 | 1600 | |
ffeedafb AS |
1601 | const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; |
1602 | const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; | |
1603 | const struct bpf_func_proto bpf_get_current_comm_proto __weak; | |
6bdc9c4c | 1604 | const struct bpf_func_proto bpf_sock_map_update_proto __weak; |
bd570ff9 | 1605 | |
0756ea3e AS |
1606 | const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) |
1607 | { | |
1608 | return NULL; | |
1609 | } | |
03e69b50 | 1610 | |
555c8a86 DB |
1611 | u64 __weak |
1612 | bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, | |
1613 | void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) | |
bd570ff9 | 1614 | { |
555c8a86 | 1615 | return -ENOTSUPP; |
bd570ff9 DB |
1616 | } |
1617 | ||
3324b584 DB |
1618 | /* Always built-in helper functions. */ |
1619 | const struct bpf_func_proto bpf_tail_call_proto = { | |
1620 | .func = NULL, | |
1621 | .gpl_only = false, | |
1622 | .ret_type = RET_VOID, | |
1623 | .arg1_type = ARG_PTR_TO_CTX, | |
1624 | .arg2_type = ARG_CONST_MAP_PTR, | |
1625 | .arg3_type = ARG_ANYTHING, | |
1626 | }; | |
1627 | ||
9383191d DB |
1628 | /* Stub for JITs that only support cBPF. eBPF programs are interpreted. |
1629 | * It is encouraged to implement bpf_int_jit_compile() instead, so that | |
1630 | * eBPF and implicitly also cBPF can get JITed! | |
1631 | */ | |
d1c55ab5 | 1632 | struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog) |
3324b584 | 1633 | { |
d1c55ab5 | 1634 | return prog; |
3324b584 DB |
1635 | } |
1636 | ||
9383191d DB |
1637 | /* Stub for JITs that support eBPF. All cBPF code gets transformed into |
1638 | * eBPF by the kernel and is later compiled by bpf_int_jit_compile(). | |
1639 | */ | |
1640 | void __weak bpf_jit_compile(struct bpf_prog *prog) | |
1641 | { | |
1642 | } | |
1643 | ||
17bedab2 | 1644 | bool __weak bpf_helper_changes_pkt_data(void *func) |
969bf05e AS |
1645 | { |
1646 | return false; | |
1647 | } | |
1648 | ||
f89b7755 AS |
1649 | /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call |
1650 | * skb_copy_bits(), so provide a weak definition of it for NET-less config. | |
1651 | */ | |
1652 | int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, | |
1653 | int len) | |
1654 | { | |
1655 | return -EFAULT; | |
1656 | } | |
a67edbf4 DB |
1657 | |
1658 | /* All definitions of tracepoints related to BPF. */ | |
1659 | #define CREATE_TRACE_POINTS | |
1660 | #include <linux/bpf_trace.h> | |
1661 | ||
1662 | EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); | |
1663 | ||
9185a610 SRV |
1664 | /* These are only used within the BPF_SYSCALL code */ |
1665 | #ifdef CONFIG_BPF_SYSCALL | |
a67edbf4 DB |
1666 | EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_get_type); |
1667 | EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_put_rcu); | |
9185a610 | 1668 | #endif |