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 | ||
09756af4 AS |
88 | aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags); |
89 | if (aux == NULL) { | |
60a3b225 DB |
90 | vfree(fp); |
91 | return NULL; | |
92 | } | |
93 | ||
94 | fp->pages = size / PAGE_SIZE; | |
09756af4 | 95 | fp->aux = aux; |
e9d8afa9 | 96 | fp->aux->prog = fp; |
60b58afc | 97 | fp->jit_requested = ebpf_jit_enabled(); |
60a3b225 | 98 | |
74451e66 DB |
99 | INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode); |
100 | ||
60a3b225 DB |
101 | return fp; |
102 | } | |
103 | EXPORT_SYMBOL_GPL(bpf_prog_alloc); | |
104 | ||
105 | struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, | |
106 | gfp_t gfp_extra_flags) | |
107 | { | |
19809c2d | 108 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
60a3b225 | 109 | struct bpf_prog *fp; |
5ccb071e DB |
110 | u32 pages, delta; |
111 | int ret; | |
60a3b225 DB |
112 | |
113 | BUG_ON(fp_old == NULL); | |
114 | ||
115 | size = round_up(size, PAGE_SIZE); | |
5ccb071e DB |
116 | pages = size / PAGE_SIZE; |
117 | if (pages <= fp_old->pages) | |
60a3b225 DB |
118 | return fp_old; |
119 | ||
5ccb071e DB |
120 | delta = pages - fp_old->pages; |
121 | ret = __bpf_prog_charge(fp_old->aux->user, delta); | |
122 | if (ret) | |
123 | return NULL; | |
124 | ||
60a3b225 | 125 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); |
5ccb071e DB |
126 | if (fp == NULL) { |
127 | __bpf_prog_uncharge(fp_old->aux->user, delta); | |
128 | } else { | |
60a3b225 | 129 | memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); |
5ccb071e | 130 | fp->pages = pages; |
e9d8afa9 | 131 | fp->aux->prog = fp; |
60a3b225 | 132 | |
09756af4 | 133 | /* We keep fp->aux from fp_old around in the new |
60a3b225 DB |
134 | * reallocated structure. |
135 | */ | |
09756af4 | 136 | fp_old->aux = NULL; |
60a3b225 DB |
137 | __bpf_prog_free(fp_old); |
138 | } | |
139 | ||
140 | return fp; | |
141 | } | |
60a3b225 DB |
142 | |
143 | void __bpf_prog_free(struct bpf_prog *fp) | |
144 | { | |
09756af4 | 145 | kfree(fp->aux); |
60a3b225 DB |
146 | vfree(fp); |
147 | } | |
60a3b225 | 148 | |
f1f7714e | 149 | int bpf_prog_calc_tag(struct bpf_prog *fp) |
7bd509e3 DB |
150 | { |
151 | const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64); | |
f1f7714e DB |
152 | u32 raw_size = bpf_prog_tag_scratch_size(fp); |
153 | u32 digest[SHA_DIGEST_WORDS]; | |
aafe6ae9 | 154 | u32 ws[SHA_WORKSPACE_WORDS]; |
7bd509e3 | 155 | u32 i, bsize, psize, blocks; |
aafe6ae9 | 156 | struct bpf_insn *dst; |
7bd509e3 | 157 | bool was_ld_map; |
aafe6ae9 | 158 | u8 *raw, *todo; |
7bd509e3 DB |
159 | __be32 *result; |
160 | __be64 *bits; | |
161 | ||
aafe6ae9 DB |
162 | raw = vmalloc(raw_size); |
163 | if (!raw) | |
164 | return -ENOMEM; | |
165 | ||
f1f7714e | 166 | sha_init(digest); |
7bd509e3 DB |
167 | memset(ws, 0, sizeof(ws)); |
168 | ||
169 | /* We need to take out the map fd for the digest calculation | |
170 | * since they are unstable from user space side. | |
171 | */ | |
aafe6ae9 | 172 | dst = (void *)raw; |
7bd509e3 DB |
173 | for (i = 0, was_ld_map = false; i < fp->len; i++) { |
174 | dst[i] = fp->insnsi[i]; | |
175 | if (!was_ld_map && | |
176 | dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
177 | dst[i].src_reg == BPF_PSEUDO_MAP_FD) { | |
178 | was_ld_map = true; | |
179 | dst[i].imm = 0; | |
180 | } else if (was_ld_map && | |
181 | dst[i].code == 0 && | |
182 | dst[i].dst_reg == 0 && | |
183 | dst[i].src_reg == 0 && | |
184 | dst[i].off == 0) { | |
185 | was_ld_map = false; | |
186 | dst[i].imm = 0; | |
187 | } else { | |
188 | was_ld_map = false; | |
189 | } | |
190 | } | |
191 | ||
aafe6ae9 DB |
192 | psize = bpf_prog_insn_size(fp); |
193 | memset(&raw[psize], 0, raw_size - psize); | |
7bd509e3 DB |
194 | raw[psize++] = 0x80; |
195 | ||
196 | bsize = round_up(psize, SHA_MESSAGE_BYTES); | |
197 | blocks = bsize / SHA_MESSAGE_BYTES; | |
aafe6ae9 | 198 | todo = raw; |
7bd509e3 DB |
199 | if (bsize - psize >= sizeof(__be64)) { |
200 | bits = (__be64 *)(todo + bsize - sizeof(__be64)); | |
201 | } else { | |
202 | bits = (__be64 *)(todo + bsize + bits_offset); | |
203 | blocks++; | |
204 | } | |
205 | *bits = cpu_to_be64((psize - 1) << 3); | |
206 | ||
207 | while (blocks--) { | |
f1f7714e | 208 | sha_transform(digest, todo, ws); |
7bd509e3 DB |
209 | todo += SHA_MESSAGE_BYTES; |
210 | } | |
211 | ||
f1f7714e | 212 | result = (__force __be32 *)digest; |
7bd509e3 | 213 | for (i = 0; i < SHA_DIGEST_WORDS; i++) |
f1f7714e DB |
214 | result[i] = cpu_to_be32(digest[i]); |
215 | memcpy(fp->tag, result, sizeof(fp->tag)); | |
aafe6ae9 DB |
216 | |
217 | vfree(raw); | |
218 | return 0; | |
7bd509e3 DB |
219 | } |
220 | ||
c237ee5e DB |
221 | static void bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta) |
222 | { | |
223 | struct bpf_insn *insn = prog->insnsi; | |
224 | u32 i, insn_cnt = prog->len; | |
1ea47e01 AS |
225 | bool pseudo_call; |
226 | u8 code; | |
227 | int off; | |
c237ee5e DB |
228 | |
229 | for (i = 0; i < insn_cnt; i++, insn++) { | |
1ea47e01 AS |
230 | code = insn->code; |
231 | if (BPF_CLASS(code) != BPF_JMP) | |
c237ee5e | 232 | continue; |
1ea47e01 AS |
233 | if (BPF_OP(code) == BPF_EXIT) |
234 | continue; | |
235 | if (BPF_OP(code) == BPF_CALL) { | |
236 | if (insn->src_reg == BPF_PSEUDO_CALL) | |
237 | pseudo_call = true; | |
238 | else | |
239 | continue; | |
240 | } else { | |
241 | pseudo_call = false; | |
242 | } | |
243 | off = pseudo_call ? insn->imm : insn->off; | |
c237ee5e DB |
244 | |
245 | /* Adjust offset of jmps if we cross boundaries. */ | |
1ea47e01 AS |
246 | if (i < pos && i + off + 1 > pos) |
247 | off += delta; | |
248 | else if (i > pos + delta && i + off + 1 <= pos + delta) | |
249 | off -= delta; | |
250 | ||
251 | if (pseudo_call) | |
252 | insn->imm = off; | |
253 | else | |
254 | insn->off = off; | |
c237ee5e DB |
255 | } |
256 | } | |
257 | ||
258 | struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, | |
259 | const struct bpf_insn *patch, u32 len) | |
260 | { | |
261 | u32 insn_adj_cnt, insn_rest, insn_delta = len - 1; | |
262 | struct bpf_prog *prog_adj; | |
263 | ||
264 | /* Since our patchlet doesn't expand the image, we're done. */ | |
265 | if (insn_delta == 0) { | |
266 | memcpy(prog->insnsi + off, patch, sizeof(*patch)); | |
267 | return prog; | |
268 | } | |
269 | ||
270 | insn_adj_cnt = prog->len + insn_delta; | |
271 | ||
272 | /* Several new instructions need to be inserted. Make room | |
273 | * for them. Likely, there's no need for a new allocation as | |
274 | * last page could have large enough tailroom. | |
275 | */ | |
276 | prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt), | |
277 | GFP_USER); | |
278 | if (!prog_adj) | |
279 | return NULL; | |
280 | ||
281 | prog_adj->len = insn_adj_cnt; | |
282 | ||
283 | /* Patching happens in 3 steps: | |
284 | * | |
285 | * 1) Move over tail of insnsi from next instruction onwards, | |
286 | * so we can patch the single target insn with one or more | |
287 | * new ones (patching is always from 1 to n insns, n > 0). | |
288 | * 2) Inject new instructions at the target location. | |
289 | * 3) Adjust branch offsets if necessary. | |
290 | */ | |
291 | insn_rest = insn_adj_cnt - off - len; | |
292 | ||
293 | memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1, | |
294 | sizeof(*patch) * insn_rest); | |
295 | memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len); | |
296 | ||
297 | bpf_adj_branches(prog_adj, off, insn_delta); | |
298 | ||
299 | return prog_adj; | |
300 | } | |
301 | ||
b954d834 | 302 | #ifdef CONFIG_BPF_JIT |
fa9dd599 DB |
303 | /* All BPF JIT sysctl knobs here. */ |
304 | int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON); | |
305 | int bpf_jit_harden __read_mostly; | |
306 | int bpf_jit_kallsyms __read_mostly; | |
307 | ||
74451e66 DB |
308 | static __always_inline void |
309 | bpf_get_prog_addr_region(const struct bpf_prog *prog, | |
310 | unsigned long *symbol_start, | |
311 | unsigned long *symbol_end) | |
312 | { | |
313 | const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog); | |
314 | unsigned long addr = (unsigned long)hdr; | |
315 | ||
316 | WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog)); | |
317 | ||
318 | *symbol_start = addr; | |
319 | *symbol_end = addr + hdr->pages * PAGE_SIZE; | |
320 | } | |
321 | ||
322 | static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) | |
323 | { | |
368211fb MKL |
324 | const char *end = sym + KSYM_NAME_LEN; |
325 | ||
74451e66 | 326 | BUILD_BUG_ON(sizeof("bpf_prog_") + |
368211fb MKL |
327 | sizeof(prog->tag) * 2 + |
328 | /* name has been null terminated. | |
329 | * We should need +1 for the '_' preceding | |
330 | * the name. However, the null character | |
331 | * is double counted between the name and the | |
332 | * sizeof("bpf_prog_") above, so we omit | |
333 | * the +1 here. | |
334 | */ | |
335 | sizeof(prog->aux->name) > KSYM_NAME_LEN); | |
74451e66 DB |
336 | |
337 | sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); | |
338 | sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); | |
368211fb MKL |
339 | if (prog->aux->name[0]) |
340 | snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); | |
341 | else | |
342 | *sym = 0; | |
74451e66 DB |
343 | } |
344 | ||
345 | static __always_inline unsigned long | |
346 | bpf_get_prog_addr_start(struct latch_tree_node *n) | |
347 | { | |
348 | unsigned long symbol_start, symbol_end; | |
349 | const struct bpf_prog_aux *aux; | |
350 | ||
351 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
352 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
353 | ||
354 | return symbol_start; | |
355 | } | |
356 | ||
357 | static __always_inline bool bpf_tree_less(struct latch_tree_node *a, | |
358 | struct latch_tree_node *b) | |
359 | { | |
360 | return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b); | |
361 | } | |
362 | ||
363 | static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n) | |
364 | { | |
365 | unsigned long val = (unsigned long)key; | |
366 | unsigned long symbol_start, symbol_end; | |
367 | const struct bpf_prog_aux *aux; | |
368 | ||
369 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
370 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
371 | ||
372 | if (val < symbol_start) | |
373 | return -1; | |
374 | if (val >= symbol_end) | |
375 | return 1; | |
376 | ||
377 | return 0; | |
378 | } | |
379 | ||
380 | static const struct latch_tree_ops bpf_tree_ops = { | |
381 | .less = bpf_tree_less, | |
382 | .comp = bpf_tree_comp, | |
383 | }; | |
384 | ||
385 | static DEFINE_SPINLOCK(bpf_lock); | |
386 | static LIST_HEAD(bpf_kallsyms); | |
387 | static struct latch_tree_root bpf_tree __cacheline_aligned; | |
388 | ||
74451e66 DB |
389 | static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux) |
390 | { | |
391 | WARN_ON_ONCE(!list_empty(&aux->ksym_lnode)); | |
392 | list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms); | |
393 | latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
394 | } | |
395 | ||
396 | static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux) | |
397 | { | |
398 | if (list_empty(&aux->ksym_lnode)) | |
399 | return; | |
400 | ||
401 | latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
402 | list_del_rcu(&aux->ksym_lnode); | |
403 | } | |
404 | ||
405 | static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) | |
406 | { | |
407 | return fp->jited && !bpf_prog_was_classic(fp); | |
408 | } | |
409 | ||
410 | static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) | |
411 | { | |
412 | return list_empty(&fp->aux->ksym_lnode) || | |
413 | fp->aux->ksym_lnode.prev == LIST_POISON2; | |
414 | } | |
415 | ||
416 | void bpf_prog_kallsyms_add(struct bpf_prog *fp) | |
417 | { | |
74451e66 DB |
418 | if (!bpf_prog_kallsyms_candidate(fp) || |
419 | !capable(CAP_SYS_ADMIN)) | |
420 | return; | |
421 | ||
d24f7c7f | 422 | spin_lock_bh(&bpf_lock); |
74451e66 | 423 | bpf_prog_ksym_node_add(fp->aux); |
d24f7c7f | 424 | spin_unlock_bh(&bpf_lock); |
74451e66 DB |
425 | } |
426 | ||
427 | void bpf_prog_kallsyms_del(struct bpf_prog *fp) | |
428 | { | |
74451e66 DB |
429 | if (!bpf_prog_kallsyms_candidate(fp)) |
430 | return; | |
431 | ||
d24f7c7f | 432 | spin_lock_bh(&bpf_lock); |
74451e66 | 433 | bpf_prog_ksym_node_del(fp->aux); |
d24f7c7f | 434 | spin_unlock_bh(&bpf_lock); |
74451e66 DB |
435 | } |
436 | ||
437 | static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr) | |
438 | { | |
439 | struct latch_tree_node *n; | |
440 | ||
441 | if (!bpf_jit_kallsyms_enabled()) | |
442 | return NULL; | |
443 | ||
444 | n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); | |
445 | return n ? | |
446 | container_of(n, struct bpf_prog_aux, ksym_tnode)->prog : | |
447 | NULL; | |
448 | } | |
449 | ||
450 | const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, | |
451 | unsigned long *off, char *sym) | |
452 | { | |
453 | unsigned long symbol_start, symbol_end; | |
454 | struct bpf_prog *prog; | |
455 | char *ret = NULL; | |
456 | ||
457 | rcu_read_lock(); | |
458 | prog = bpf_prog_kallsyms_find(addr); | |
459 | if (prog) { | |
460 | bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end); | |
461 | bpf_get_prog_name(prog, sym); | |
462 | ||
463 | ret = sym; | |
464 | if (size) | |
465 | *size = symbol_end - symbol_start; | |
466 | if (off) | |
467 | *off = addr - symbol_start; | |
468 | } | |
469 | rcu_read_unlock(); | |
470 | ||
471 | return ret; | |
472 | } | |
473 | ||
474 | bool is_bpf_text_address(unsigned long addr) | |
475 | { | |
476 | bool ret; | |
477 | ||
478 | rcu_read_lock(); | |
479 | ret = bpf_prog_kallsyms_find(addr) != NULL; | |
480 | rcu_read_unlock(); | |
481 | ||
482 | return ret; | |
483 | } | |
484 | ||
485 | int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, | |
486 | char *sym) | |
487 | { | |
488 | unsigned long symbol_start, symbol_end; | |
489 | struct bpf_prog_aux *aux; | |
490 | unsigned int it = 0; | |
491 | int ret = -ERANGE; | |
492 | ||
493 | if (!bpf_jit_kallsyms_enabled()) | |
494 | return ret; | |
495 | ||
496 | rcu_read_lock(); | |
497 | list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) { | |
498 | if (it++ != symnum) | |
499 | continue; | |
500 | ||
501 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
502 | bpf_get_prog_name(aux->prog, sym); | |
503 | ||
504 | *value = symbol_start; | |
505 | *type = BPF_SYM_ELF_TYPE; | |
506 | ||
507 | ret = 0; | |
508 | break; | |
509 | } | |
510 | rcu_read_unlock(); | |
511 | ||
512 | return ret; | |
513 | } | |
514 | ||
738cbe72 DB |
515 | struct bpf_binary_header * |
516 | bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, | |
517 | unsigned int alignment, | |
518 | bpf_jit_fill_hole_t bpf_fill_ill_insns) | |
519 | { | |
520 | struct bpf_binary_header *hdr; | |
521 | unsigned int size, hole, start; | |
522 | ||
523 | /* Most of BPF filters are really small, but if some of them | |
524 | * fill a page, allow at least 128 extra bytes to insert a | |
525 | * random section of illegal instructions. | |
526 | */ | |
527 | size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); | |
528 | hdr = module_alloc(size); | |
529 | if (hdr == NULL) | |
530 | return NULL; | |
531 | ||
532 | /* Fill space with illegal/arch-dep instructions. */ | |
533 | bpf_fill_ill_insns(hdr, size); | |
534 | ||
535 | hdr->pages = size / PAGE_SIZE; | |
536 | hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), | |
537 | PAGE_SIZE - sizeof(*hdr)); | |
b7552e1b | 538 | start = (get_random_int() % hole) & ~(alignment - 1); |
738cbe72 DB |
539 | |
540 | /* Leave a random number of instructions before BPF code. */ | |
541 | *image_ptr = &hdr->image[start]; | |
542 | ||
543 | return hdr; | |
544 | } | |
545 | ||
546 | void bpf_jit_binary_free(struct bpf_binary_header *hdr) | |
547 | { | |
be1f221c | 548 | module_memfree(hdr); |
738cbe72 | 549 | } |
4f3446bb | 550 | |
74451e66 DB |
551 | /* This symbol is only overridden by archs that have different |
552 | * requirements than the usual eBPF JITs, f.e. when they only | |
553 | * implement cBPF JIT, do not set images read-only, etc. | |
554 | */ | |
555 | void __weak bpf_jit_free(struct bpf_prog *fp) | |
556 | { | |
557 | if (fp->jited) { | |
558 | struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp); | |
559 | ||
560 | bpf_jit_binary_unlock_ro(hdr); | |
561 | bpf_jit_binary_free(hdr); | |
562 | ||
563 | WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); | |
564 | } | |
565 | ||
566 | bpf_prog_unlock_free(fp); | |
567 | } | |
568 | ||
4f3446bb DB |
569 | static int bpf_jit_blind_insn(const struct bpf_insn *from, |
570 | const struct bpf_insn *aux, | |
571 | struct bpf_insn *to_buff) | |
572 | { | |
573 | struct bpf_insn *to = to_buff; | |
b7552e1b | 574 | u32 imm_rnd = get_random_int(); |
4f3446bb DB |
575 | s16 off; |
576 | ||
577 | BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); | |
578 | BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); | |
579 | ||
580 | if (from->imm == 0 && | |
581 | (from->code == (BPF_ALU | BPF_MOV | BPF_K) || | |
582 | from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { | |
583 | *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg); | |
584 | goto out; | |
585 | } | |
586 | ||
587 | switch (from->code) { | |
588 | case BPF_ALU | BPF_ADD | BPF_K: | |
589 | case BPF_ALU | BPF_SUB | BPF_K: | |
590 | case BPF_ALU | BPF_AND | BPF_K: | |
591 | case BPF_ALU | BPF_OR | BPF_K: | |
592 | case BPF_ALU | BPF_XOR | BPF_K: | |
593 | case BPF_ALU | BPF_MUL | BPF_K: | |
594 | case BPF_ALU | BPF_MOV | BPF_K: | |
595 | case BPF_ALU | BPF_DIV | BPF_K: | |
596 | case BPF_ALU | BPF_MOD | BPF_K: | |
597 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
598 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
599 | *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX); | |
600 | break; | |
601 | ||
602 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
603 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
604 | case BPF_ALU64 | BPF_AND | BPF_K: | |
605 | case BPF_ALU64 | BPF_OR | BPF_K: | |
606 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
607 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
608 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
609 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
610 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
611 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
612 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
613 | *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX); | |
614 | break; | |
615 | ||
616 | case BPF_JMP | BPF_JEQ | BPF_K: | |
617 | case BPF_JMP | BPF_JNE | BPF_K: | |
618 | case BPF_JMP | BPF_JGT | BPF_K: | |
92b31a9a | 619 | case BPF_JMP | BPF_JLT | BPF_K: |
4f3446bb | 620 | case BPF_JMP | BPF_JGE | BPF_K: |
92b31a9a | 621 | case BPF_JMP | BPF_JLE | BPF_K: |
4f3446bb | 622 | case BPF_JMP | BPF_JSGT | BPF_K: |
92b31a9a | 623 | case BPF_JMP | BPF_JSLT | BPF_K: |
4f3446bb | 624 | case BPF_JMP | BPF_JSGE | BPF_K: |
92b31a9a | 625 | case BPF_JMP | BPF_JSLE | BPF_K: |
4f3446bb DB |
626 | case BPF_JMP | BPF_JSET | BPF_K: |
627 | /* Accommodate for extra offset in case of a backjump. */ | |
628 | off = from->off; | |
629 | if (off < 0) | |
630 | off -= 2; | |
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_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); | |
634 | break; | |
635 | ||
636 | case BPF_LD | BPF_ABS | BPF_W: | |
637 | case BPF_LD | BPF_ABS | BPF_H: | |
638 | case BPF_LD | BPF_ABS | 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_LD_IND(from->code, BPF_REG_AX, 0); | |
642 | break; | |
643 | ||
644 | case BPF_LD | BPF_IND | BPF_W: | |
645 | case BPF_LD | BPF_IND | BPF_H: | |
646 | case BPF_LD | BPF_IND | BPF_B: | |
647 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
648 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
649 | *to++ = BPF_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg); | |
650 | *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); | |
651 | break; | |
652 | ||
653 | case BPF_LD | BPF_IMM | BPF_DW: | |
654 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); | |
655 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
656 | *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); | |
657 | *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX); | |
658 | break; | |
659 | case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */ | |
660 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm); | |
661 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
662 | *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX); | |
663 | break; | |
664 | ||
665 | case BPF_ST | BPF_MEM | BPF_DW: | |
666 | case BPF_ST | BPF_MEM | BPF_W: | |
667 | case BPF_ST | BPF_MEM | BPF_H: | |
668 | case BPF_ST | BPF_MEM | BPF_B: | |
669 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
670 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
671 | *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); | |
672 | break; | |
673 | } | |
674 | out: | |
675 | return to - to_buff; | |
676 | } | |
677 | ||
678 | static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other, | |
679 | gfp_t gfp_extra_flags) | |
680 | { | |
19809c2d | 681 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
4f3446bb DB |
682 | struct bpf_prog *fp; |
683 | ||
684 | fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL); | |
685 | if (fp != NULL) { | |
4f3446bb DB |
686 | /* aux->prog still points to the fp_other one, so |
687 | * when promoting the clone to the real program, | |
688 | * this still needs to be adapted. | |
689 | */ | |
690 | memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE); | |
691 | } | |
692 | ||
693 | return fp; | |
694 | } | |
695 | ||
696 | static void bpf_prog_clone_free(struct bpf_prog *fp) | |
697 | { | |
698 | /* aux was stolen by the other clone, so we cannot free | |
699 | * it from this path! It will be freed eventually by the | |
700 | * other program on release. | |
701 | * | |
702 | * At this point, we don't need a deferred release since | |
703 | * clone is guaranteed to not be locked. | |
704 | */ | |
705 | fp->aux = NULL; | |
706 | __bpf_prog_free(fp); | |
707 | } | |
708 | ||
709 | void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other) | |
710 | { | |
711 | /* We have to repoint aux->prog to self, as we don't | |
712 | * know whether fp here is the clone or the original. | |
713 | */ | |
714 | fp->aux->prog = fp; | |
715 | bpf_prog_clone_free(fp_other); | |
716 | } | |
717 | ||
718 | struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) | |
719 | { | |
720 | struct bpf_insn insn_buff[16], aux[2]; | |
721 | struct bpf_prog *clone, *tmp; | |
722 | int insn_delta, insn_cnt; | |
723 | struct bpf_insn *insn; | |
724 | int i, rewritten; | |
725 | ||
1c2a088a | 726 | if (!bpf_jit_blinding_enabled(prog) || prog->blinded) |
4f3446bb DB |
727 | return prog; |
728 | ||
729 | clone = bpf_prog_clone_create(prog, GFP_USER); | |
730 | if (!clone) | |
731 | return ERR_PTR(-ENOMEM); | |
732 | ||
733 | insn_cnt = clone->len; | |
734 | insn = clone->insnsi; | |
735 | ||
736 | for (i = 0; i < insn_cnt; i++, insn++) { | |
737 | /* We temporarily need to hold the original ld64 insn | |
738 | * so that we can still access the first part in the | |
739 | * second blinding run. | |
740 | */ | |
741 | if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
742 | insn[1].code == 0) | |
743 | memcpy(aux, insn, sizeof(aux)); | |
744 | ||
745 | rewritten = bpf_jit_blind_insn(insn, aux, insn_buff); | |
746 | if (!rewritten) | |
747 | continue; | |
748 | ||
749 | tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten); | |
750 | if (!tmp) { | |
751 | /* Patching may have repointed aux->prog during | |
752 | * realloc from the original one, so we need to | |
753 | * fix it up here on error. | |
754 | */ | |
755 | bpf_jit_prog_release_other(prog, clone); | |
756 | return ERR_PTR(-ENOMEM); | |
757 | } | |
758 | ||
759 | clone = tmp; | |
760 | insn_delta = rewritten - 1; | |
761 | ||
762 | /* Walk new program and skip insns we just inserted. */ | |
763 | insn = clone->insnsi + i + insn_delta; | |
764 | insn_cnt += insn_delta; | |
765 | i += insn_delta; | |
766 | } | |
767 | ||
1c2a088a | 768 | clone->blinded = 1; |
4f3446bb DB |
769 | return clone; |
770 | } | |
b954d834 | 771 | #endif /* CONFIG_BPF_JIT */ |
738cbe72 | 772 | |
f5bffecd AS |
773 | /* Base function for offset calculation. Needs to go into .text section, |
774 | * therefore keeping it non-static as well; will also be used by JITs | |
7105e828 DB |
775 | * anyway later on, so do not let the compiler omit it. This also needs |
776 | * to go into kallsyms for correlation from e.g. bpftool, so naming | |
777 | * must not change. | |
f5bffecd AS |
778 | */ |
779 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
780 | { | |
781 | return 0; | |
782 | } | |
4d9c5c53 | 783 | EXPORT_SYMBOL_GPL(__bpf_call_base); |
f5bffecd | 784 | |
5e581dad DB |
785 | /* All UAPI available opcodes. */ |
786 | #define BPF_INSN_MAP(INSN_2, INSN_3) \ | |
787 | /* 32 bit ALU operations. */ \ | |
788 | /* Register based. */ \ | |
789 | INSN_3(ALU, ADD, X), \ | |
790 | INSN_3(ALU, SUB, X), \ | |
791 | INSN_3(ALU, AND, X), \ | |
792 | INSN_3(ALU, OR, X), \ | |
793 | INSN_3(ALU, LSH, X), \ | |
794 | INSN_3(ALU, RSH, X), \ | |
795 | INSN_3(ALU, XOR, X), \ | |
796 | INSN_3(ALU, MUL, X), \ | |
797 | INSN_3(ALU, MOV, X), \ | |
798 | INSN_3(ALU, DIV, X), \ | |
799 | INSN_3(ALU, MOD, X), \ | |
800 | INSN_2(ALU, NEG), \ | |
801 | INSN_3(ALU, END, TO_BE), \ | |
802 | INSN_3(ALU, END, TO_LE), \ | |
803 | /* Immediate based. */ \ | |
804 | INSN_3(ALU, ADD, K), \ | |
805 | INSN_3(ALU, SUB, K), \ | |
806 | INSN_3(ALU, AND, K), \ | |
807 | INSN_3(ALU, OR, K), \ | |
808 | INSN_3(ALU, LSH, K), \ | |
809 | INSN_3(ALU, RSH, K), \ | |
810 | INSN_3(ALU, XOR, K), \ | |
811 | INSN_3(ALU, MUL, K), \ | |
812 | INSN_3(ALU, MOV, K), \ | |
813 | INSN_3(ALU, DIV, K), \ | |
814 | INSN_3(ALU, MOD, K), \ | |
815 | /* 64 bit ALU operations. */ \ | |
816 | /* Register based. */ \ | |
817 | INSN_3(ALU64, ADD, X), \ | |
818 | INSN_3(ALU64, SUB, X), \ | |
819 | INSN_3(ALU64, AND, X), \ | |
820 | INSN_3(ALU64, OR, X), \ | |
821 | INSN_3(ALU64, LSH, X), \ | |
822 | INSN_3(ALU64, RSH, X), \ | |
823 | INSN_3(ALU64, XOR, X), \ | |
824 | INSN_3(ALU64, MUL, X), \ | |
825 | INSN_3(ALU64, MOV, X), \ | |
826 | INSN_3(ALU64, ARSH, X), \ | |
827 | INSN_3(ALU64, DIV, X), \ | |
828 | INSN_3(ALU64, MOD, X), \ | |
829 | INSN_2(ALU64, NEG), \ | |
830 | /* Immediate based. */ \ | |
831 | INSN_3(ALU64, ADD, K), \ | |
832 | INSN_3(ALU64, SUB, K), \ | |
833 | INSN_3(ALU64, AND, K), \ | |
834 | INSN_3(ALU64, OR, K), \ | |
835 | INSN_3(ALU64, LSH, K), \ | |
836 | INSN_3(ALU64, RSH, K), \ | |
837 | INSN_3(ALU64, XOR, K), \ | |
838 | INSN_3(ALU64, MUL, K), \ | |
839 | INSN_3(ALU64, MOV, K), \ | |
840 | INSN_3(ALU64, ARSH, K), \ | |
841 | INSN_3(ALU64, DIV, K), \ | |
842 | INSN_3(ALU64, MOD, K), \ | |
843 | /* Call instruction. */ \ | |
844 | INSN_2(JMP, CALL), \ | |
845 | /* Exit instruction. */ \ | |
846 | INSN_2(JMP, EXIT), \ | |
847 | /* Jump instructions. */ \ | |
848 | /* Register based. */ \ | |
849 | INSN_3(JMP, JEQ, X), \ | |
850 | INSN_3(JMP, JNE, X), \ | |
851 | INSN_3(JMP, JGT, X), \ | |
852 | INSN_3(JMP, JLT, X), \ | |
853 | INSN_3(JMP, JGE, X), \ | |
854 | INSN_3(JMP, JLE, X), \ | |
855 | INSN_3(JMP, JSGT, X), \ | |
856 | INSN_3(JMP, JSLT, X), \ | |
857 | INSN_3(JMP, JSGE, X), \ | |
858 | INSN_3(JMP, JSLE, X), \ | |
859 | INSN_3(JMP, JSET, X), \ | |
860 | /* Immediate based. */ \ | |
861 | INSN_3(JMP, JEQ, K), \ | |
862 | INSN_3(JMP, JNE, K), \ | |
863 | INSN_3(JMP, JGT, K), \ | |
864 | INSN_3(JMP, JLT, K), \ | |
865 | INSN_3(JMP, JGE, K), \ | |
866 | INSN_3(JMP, JLE, K), \ | |
867 | INSN_3(JMP, JSGT, K), \ | |
868 | INSN_3(JMP, JSLT, K), \ | |
869 | INSN_3(JMP, JSGE, K), \ | |
870 | INSN_3(JMP, JSLE, K), \ | |
871 | INSN_3(JMP, JSET, K), \ | |
872 | INSN_2(JMP, JA), \ | |
873 | /* Store instructions. */ \ | |
874 | /* Register based. */ \ | |
875 | INSN_3(STX, MEM, B), \ | |
876 | INSN_3(STX, MEM, H), \ | |
877 | INSN_3(STX, MEM, W), \ | |
878 | INSN_3(STX, MEM, DW), \ | |
879 | INSN_3(STX, XADD, W), \ | |
880 | INSN_3(STX, XADD, DW), \ | |
881 | /* Immediate based. */ \ | |
882 | INSN_3(ST, MEM, B), \ | |
883 | INSN_3(ST, MEM, H), \ | |
884 | INSN_3(ST, MEM, W), \ | |
885 | INSN_3(ST, MEM, DW), \ | |
886 | /* Load instructions. */ \ | |
887 | /* Register based. */ \ | |
888 | INSN_3(LDX, MEM, B), \ | |
889 | INSN_3(LDX, MEM, H), \ | |
890 | INSN_3(LDX, MEM, W), \ | |
891 | INSN_3(LDX, MEM, DW), \ | |
892 | /* Immediate based. */ \ | |
893 | INSN_3(LD, IMM, DW), \ | |
894 | /* Misc (old cBPF carry-over). */ \ | |
895 | INSN_3(LD, ABS, B), \ | |
896 | INSN_3(LD, ABS, H), \ | |
897 | INSN_3(LD, ABS, W), \ | |
898 | INSN_3(LD, IND, B), \ | |
899 | INSN_3(LD, IND, H), \ | |
900 | INSN_3(LD, IND, W) | |
901 | ||
902 | bool bpf_opcode_in_insntable(u8 code) | |
903 | { | |
904 | #define BPF_INSN_2_TBL(x, y) [BPF_##x | BPF_##y] = true | |
905 | #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true | |
906 | static const bool public_insntable[256] = { | |
907 | [0 ... 255] = false, | |
908 | /* Now overwrite non-defaults ... */ | |
909 | BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL), | |
910 | }; | |
911 | #undef BPF_INSN_3_TBL | |
912 | #undef BPF_INSN_2_TBL | |
913 | return public_insntable[code]; | |
914 | } | |
915 | ||
290af866 | 916 | #ifndef CONFIG_BPF_JIT_ALWAYS_ON |
f5bffecd | 917 | /** |
7ae457c1 AS |
918 | * __bpf_prog_run - run eBPF program on a given context |
919 | * @ctx: is the data we are operating on | |
920 | * @insn: is the array of eBPF instructions | |
f5bffecd | 921 | * |
7ae457c1 | 922 | * Decode and execute eBPF instructions. |
f5bffecd | 923 | */ |
1ea47e01 | 924 | static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack) |
f5bffecd | 925 | { |
f696b8f4 | 926 | u64 tmp; |
5e581dad DB |
927 | #define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y |
928 | #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z | |
f5bffecd AS |
929 | static const void *jumptable[256] = { |
930 | [0 ... 255] = &&default_label, | |
931 | /* Now overwrite non-defaults ... */ | |
5e581dad DB |
932 | BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL), |
933 | /* Non-UAPI available opcodes. */ | |
1ea47e01 | 934 | [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS, |
71189fa9 | 935 | [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, |
f5bffecd | 936 | }; |
5e581dad DB |
937 | #undef BPF_INSN_3_LBL |
938 | #undef BPF_INSN_2_LBL | |
04fd61ab | 939 | u32 tail_call_cnt = 0; |
f5bffecd AS |
940 | void *ptr; |
941 | int off; | |
942 | ||
943 | #define CONT ({ insn++; goto select_insn; }) | |
944 | #define CONT_JMP ({ insn++; goto select_insn; }) | |
945 | ||
f5bffecd AS |
946 | select_insn: |
947 | goto *jumptable[insn->code]; | |
948 | ||
949 | /* ALU */ | |
950 | #define ALU(OPCODE, OP) \ | |
951 | ALU64_##OPCODE##_X: \ | |
952 | DST = DST OP SRC; \ | |
953 | CONT; \ | |
954 | ALU_##OPCODE##_X: \ | |
955 | DST = (u32) DST OP (u32) SRC; \ | |
956 | CONT; \ | |
957 | ALU64_##OPCODE##_K: \ | |
958 | DST = DST OP IMM; \ | |
959 | CONT; \ | |
960 | ALU_##OPCODE##_K: \ | |
961 | DST = (u32) DST OP (u32) IMM; \ | |
962 | CONT; | |
963 | ||
964 | ALU(ADD, +) | |
965 | ALU(SUB, -) | |
966 | ALU(AND, &) | |
967 | ALU(OR, |) | |
968 | ALU(LSH, <<) | |
969 | ALU(RSH, >>) | |
970 | ALU(XOR, ^) | |
971 | ALU(MUL, *) | |
972 | #undef ALU | |
973 | ALU_NEG: | |
974 | DST = (u32) -DST; | |
975 | CONT; | |
976 | ALU64_NEG: | |
977 | DST = -DST; | |
978 | CONT; | |
979 | ALU_MOV_X: | |
980 | DST = (u32) SRC; | |
981 | CONT; | |
982 | ALU_MOV_K: | |
983 | DST = (u32) IMM; | |
984 | CONT; | |
985 | ALU64_MOV_X: | |
986 | DST = SRC; | |
987 | CONT; | |
988 | ALU64_MOV_K: | |
989 | DST = IMM; | |
990 | CONT; | |
02ab695b AS |
991 | LD_IMM_DW: |
992 | DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; | |
993 | insn++; | |
994 | CONT; | |
f5bffecd AS |
995 | ALU64_ARSH_X: |
996 | (*(s64 *) &DST) >>= SRC; | |
997 | CONT; | |
998 | ALU64_ARSH_K: | |
999 | (*(s64 *) &DST) >>= IMM; | |
1000 | CONT; | |
1001 | ALU64_MOD_X: | |
876a7ae6 AS |
1002 | div64_u64_rem(DST, SRC, &tmp); |
1003 | DST = tmp; | |
f5bffecd AS |
1004 | CONT; |
1005 | ALU_MOD_X: | |
f5bffecd AS |
1006 | tmp = (u32) DST; |
1007 | DST = do_div(tmp, (u32) SRC); | |
1008 | CONT; | |
1009 | ALU64_MOD_K: | |
876a7ae6 AS |
1010 | div64_u64_rem(DST, IMM, &tmp); |
1011 | DST = tmp; | |
f5bffecd AS |
1012 | CONT; |
1013 | ALU_MOD_K: | |
1014 | tmp = (u32) DST; | |
1015 | DST = do_div(tmp, (u32) IMM); | |
1016 | CONT; | |
1017 | ALU64_DIV_X: | |
876a7ae6 | 1018 | DST = div64_u64(DST, SRC); |
f5bffecd AS |
1019 | CONT; |
1020 | ALU_DIV_X: | |
f5bffecd AS |
1021 | tmp = (u32) DST; |
1022 | do_div(tmp, (u32) SRC); | |
1023 | DST = (u32) tmp; | |
1024 | CONT; | |
1025 | ALU64_DIV_K: | |
876a7ae6 | 1026 | DST = div64_u64(DST, IMM); |
f5bffecd AS |
1027 | CONT; |
1028 | ALU_DIV_K: | |
1029 | tmp = (u32) DST; | |
1030 | do_div(tmp, (u32) IMM); | |
1031 | DST = (u32) tmp; | |
1032 | CONT; | |
1033 | ALU_END_TO_BE: | |
1034 | switch (IMM) { | |
1035 | case 16: | |
1036 | DST = (__force u16) cpu_to_be16(DST); | |
1037 | break; | |
1038 | case 32: | |
1039 | DST = (__force u32) cpu_to_be32(DST); | |
1040 | break; | |
1041 | case 64: | |
1042 | DST = (__force u64) cpu_to_be64(DST); | |
1043 | break; | |
1044 | } | |
1045 | CONT; | |
1046 | ALU_END_TO_LE: | |
1047 | switch (IMM) { | |
1048 | case 16: | |
1049 | DST = (__force u16) cpu_to_le16(DST); | |
1050 | break; | |
1051 | case 32: | |
1052 | DST = (__force u32) cpu_to_le32(DST); | |
1053 | break; | |
1054 | case 64: | |
1055 | DST = (__force u64) cpu_to_le64(DST); | |
1056 | break; | |
1057 | } | |
1058 | CONT; | |
1059 | ||
1060 | /* CALL */ | |
1061 | JMP_CALL: | |
1062 | /* Function call scratches BPF_R1-BPF_R5 registers, | |
1063 | * preserves BPF_R6-BPF_R9, and stores return value | |
1064 | * into BPF_R0. | |
1065 | */ | |
1066 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, | |
1067 | BPF_R4, BPF_R5); | |
1068 | CONT; | |
1069 | ||
1ea47e01 AS |
1070 | JMP_CALL_ARGS: |
1071 | BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2, | |
1072 | BPF_R3, BPF_R4, | |
1073 | BPF_R5, | |
1074 | insn + insn->off + 1); | |
1075 | CONT; | |
1076 | ||
04fd61ab AS |
1077 | JMP_TAIL_CALL: { |
1078 | struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; | |
1079 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
1080 | struct bpf_prog *prog; | |
90caccdd | 1081 | u32 index = BPF_R3; |
04fd61ab AS |
1082 | |
1083 | if (unlikely(index >= array->map.max_entries)) | |
1084 | goto out; | |
04fd61ab AS |
1085 | if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) |
1086 | goto out; | |
1087 | ||
1088 | tail_call_cnt++; | |
1089 | ||
2a36f0b9 | 1090 | prog = READ_ONCE(array->ptrs[index]); |
1ca1cc98 | 1091 | if (!prog) |
04fd61ab AS |
1092 | goto out; |
1093 | ||
c4675f93 DB |
1094 | /* ARG1 at this point is guaranteed to point to CTX from |
1095 | * the verifier side due to the fact that the tail call is | |
1096 | * handeled like a helper, that is, bpf_tail_call_proto, | |
1097 | * where arg1_type is ARG_PTR_TO_CTX. | |
1098 | */ | |
04fd61ab AS |
1099 | insn = prog->insnsi; |
1100 | goto select_insn; | |
1101 | out: | |
1102 | CONT; | |
1103 | } | |
f5bffecd AS |
1104 | /* JMP */ |
1105 | JMP_JA: | |
1106 | insn += insn->off; | |
1107 | CONT; | |
1108 | JMP_JEQ_X: | |
1109 | if (DST == SRC) { | |
1110 | insn += insn->off; | |
1111 | CONT_JMP; | |
1112 | } | |
1113 | CONT; | |
1114 | JMP_JEQ_K: | |
1115 | if (DST == IMM) { | |
1116 | insn += insn->off; | |
1117 | CONT_JMP; | |
1118 | } | |
1119 | CONT; | |
1120 | JMP_JNE_X: | |
1121 | if (DST != SRC) { | |
1122 | insn += insn->off; | |
1123 | CONT_JMP; | |
1124 | } | |
1125 | CONT; | |
1126 | JMP_JNE_K: | |
1127 | if (DST != IMM) { | |
1128 | insn += insn->off; | |
1129 | CONT_JMP; | |
1130 | } | |
1131 | CONT; | |
1132 | JMP_JGT_X: | |
1133 | if (DST > SRC) { | |
1134 | insn += insn->off; | |
1135 | CONT_JMP; | |
1136 | } | |
1137 | CONT; | |
1138 | JMP_JGT_K: | |
1139 | if (DST > IMM) { | |
1140 | insn += insn->off; | |
1141 | CONT_JMP; | |
1142 | } | |
1143 | CONT; | |
92b31a9a DB |
1144 | JMP_JLT_X: |
1145 | if (DST < SRC) { | |
1146 | insn += insn->off; | |
1147 | CONT_JMP; | |
1148 | } | |
1149 | CONT; | |
1150 | JMP_JLT_K: | |
1151 | if (DST < IMM) { | |
1152 | insn += insn->off; | |
1153 | CONT_JMP; | |
1154 | } | |
1155 | CONT; | |
f5bffecd AS |
1156 | JMP_JGE_X: |
1157 | if (DST >= SRC) { | |
1158 | insn += insn->off; | |
1159 | CONT_JMP; | |
1160 | } | |
1161 | CONT; | |
1162 | JMP_JGE_K: | |
1163 | if (DST >= IMM) { | |
1164 | insn += insn->off; | |
1165 | CONT_JMP; | |
1166 | } | |
1167 | CONT; | |
92b31a9a DB |
1168 | JMP_JLE_X: |
1169 | if (DST <= SRC) { | |
1170 | insn += insn->off; | |
1171 | CONT_JMP; | |
1172 | } | |
1173 | CONT; | |
1174 | JMP_JLE_K: | |
1175 | if (DST <= IMM) { | |
1176 | insn += insn->off; | |
1177 | CONT_JMP; | |
1178 | } | |
1179 | CONT; | |
f5bffecd AS |
1180 | JMP_JSGT_X: |
1181 | if (((s64) DST) > ((s64) SRC)) { | |
1182 | insn += insn->off; | |
1183 | CONT_JMP; | |
1184 | } | |
1185 | CONT; | |
1186 | JMP_JSGT_K: | |
1187 | if (((s64) DST) > ((s64) IMM)) { | |
1188 | insn += insn->off; | |
1189 | CONT_JMP; | |
1190 | } | |
1191 | CONT; | |
92b31a9a DB |
1192 | JMP_JSLT_X: |
1193 | if (((s64) DST) < ((s64) SRC)) { | |
1194 | insn += insn->off; | |
1195 | CONT_JMP; | |
1196 | } | |
1197 | CONT; | |
1198 | JMP_JSLT_K: | |
1199 | if (((s64) DST) < ((s64) IMM)) { | |
1200 | insn += insn->off; | |
1201 | CONT_JMP; | |
1202 | } | |
1203 | CONT; | |
f5bffecd AS |
1204 | JMP_JSGE_X: |
1205 | if (((s64) DST) >= ((s64) SRC)) { | |
1206 | insn += insn->off; | |
1207 | CONT_JMP; | |
1208 | } | |
1209 | CONT; | |
1210 | JMP_JSGE_K: | |
1211 | if (((s64) DST) >= ((s64) IMM)) { | |
1212 | insn += insn->off; | |
1213 | CONT_JMP; | |
1214 | } | |
1215 | CONT; | |
92b31a9a DB |
1216 | JMP_JSLE_X: |
1217 | if (((s64) DST) <= ((s64) SRC)) { | |
1218 | insn += insn->off; | |
1219 | CONT_JMP; | |
1220 | } | |
1221 | CONT; | |
1222 | JMP_JSLE_K: | |
1223 | if (((s64) DST) <= ((s64) IMM)) { | |
1224 | insn += insn->off; | |
1225 | CONT_JMP; | |
1226 | } | |
1227 | CONT; | |
f5bffecd AS |
1228 | JMP_JSET_X: |
1229 | if (DST & SRC) { | |
1230 | insn += insn->off; | |
1231 | CONT_JMP; | |
1232 | } | |
1233 | CONT; | |
1234 | JMP_JSET_K: | |
1235 | if (DST & IMM) { | |
1236 | insn += insn->off; | |
1237 | CONT_JMP; | |
1238 | } | |
1239 | CONT; | |
1240 | JMP_EXIT: | |
1241 | return BPF_R0; | |
1242 | ||
1243 | /* STX and ST and LDX*/ | |
1244 | #define LDST(SIZEOP, SIZE) \ | |
1245 | STX_MEM_##SIZEOP: \ | |
1246 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ | |
1247 | CONT; \ | |
1248 | ST_MEM_##SIZEOP: \ | |
1249 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
1250 | CONT; \ | |
1251 | LDX_MEM_##SIZEOP: \ | |
1252 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
1253 | CONT; | |
1254 | ||
1255 | LDST(B, u8) | |
1256 | LDST(H, u16) | |
1257 | LDST(W, u32) | |
1258 | LDST(DW, u64) | |
1259 | #undef LDST | |
1260 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ | |
1261 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) | |
1262 | (DST + insn->off)); | |
1263 | CONT; | |
1264 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ | |
1265 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) | |
1266 | (DST + insn->off)); | |
1267 | CONT; | |
1268 | LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ | |
1269 | off = IMM; | |
1270 | load_word: | |
96a94cc5 JB |
1271 | /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are only |
1272 | * appearing in the programs where ctx == skb | |
1273 | * (see may_access_skb() in the verifier). All programs | |
1274 | * keep 'ctx' in regs[BPF_REG_CTX] == BPF_R6, | |
1275 | * bpf_convert_filter() saves it in BPF_R6, internal BPF | |
1276 | * verifier will check that BPF_R6 == ctx. | |
f5bffecd AS |
1277 | * |
1278 | * BPF_ABS and BPF_IND are wrappers of function calls, | |
1279 | * so they scratch BPF_R1-BPF_R5 registers, preserve | |
1280 | * BPF_R6-BPF_R9, and store return value into BPF_R0. | |
1281 | * | |
1282 | * Implicit input: | |
1283 | * ctx == skb == BPF_R6 == CTX | |
1284 | * | |
1285 | * Explicit input: | |
1286 | * SRC == any register | |
1287 | * IMM == 32-bit immediate | |
1288 | * | |
1289 | * Output: | |
1290 | * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness | |
1291 | */ | |
1292 | ||
1293 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp); | |
1294 | if (likely(ptr != NULL)) { | |
1295 | BPF_R0 = get_unaligned_be32(ptr); | |
1296 | CONT; | |
1297 | } | |
1298 | ||
1299 | return 0; | |
1300 | LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ | |
1301 | off = IMM; | |
1302 | load_half: | |
1303 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp); | |
1304 | if (likely(ptr != NULL)) { | |
1305 | BPF_R0 = get_unaligned_be16(ptr); | |
1306 | CONT; | |
1307 | } | |
1308 | ||
1309 | return 0; | |
1310 | LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ | |
1311 | off = IMM; | |
1312 | load_byte: | |
1313 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp); | |
1314 | if (likely(ptr != NULL)) { | |
1315 | BPF_R0 = *(u8 *)ptr; | |
1316 | CONT; | |
1317 | } | |
1318 | ||
1319 | return 0; | |
1320 | LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ | |
1321 | off = IMM + SRC; | |
1322 | goto load_word; | |
1323 | LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ | |
1324 | off = IMM + SRC; | |
1325 | goto load_half; | |
1326 | LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ | |
1327 | off = IMM + SRC; | |
1328 | goto load_byte; | |
1329 | ||
1330 | default_label: | |
5e581dad DB |
1331 | /* If we ever reach this, we have a bug somewhere. Die hard here |
1332 | * instead of just returning 0; we could be somewhere in a subprog, | |
1333 | * so execution could continue otherwise which we do /not/ want. | |
1334 | * | |
1335 | * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable(). | |
1336 | */ | |
1337 | pr_warn("BPF interpreter: unknown opcode %02x\n", insn->code); | |
1338 | BUG_ON(1); | |
f5bffecd AS |
1339 | return 0; |
1340 | } | |
f696b8f4 AS |
1341 | STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */ |
1342 | ||
b870aa90 AS |
1343 | #define PROG_NAME(stack_size) __bpf_prog_run##stack_size |
1344 | #define DEFINE_BPF_PROG_RUN(stack_size) \ | |
1345 | static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ | |
1346 | { \ | |
1347 | u64 stack[stack_size / sizeof(u64)]; \ | |
1348 | u64 regs[MAX_BPF_REG]; \ | |
1349 | \ | |
1350 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ | |
1351 | ARG1 = (u64) (unsigned long) ctx; \ | |
1352 | return ___bpf_prog_run(regs, insn, stack); \ | |
f696b8f4 | 1353 | } |
f5bffecd | 1354 | |
1ea47e01 AS |
1355 | #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size |
1356 | #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \ | |
1357 | static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \ | |
1358 | const struct bpf_insn *insn) \ | |
1359 | { \ | |
1360 | u64 stack[stack_size / sizeof(u64)]; \ | |
1361 | u64 regs[MAX_BPF_REG]; \ | |
1362 | \ | |
1363 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ | |
1364 | BPF_R1 = r1; \ | |
1365 | BPF_R2 = r2; \ | |
1366 | BPF_R3 = r3; \ | |
1367 | BPF_R4 = r4; \ | |
1368 | BPF_R5 = r5; \ | |
1369 | return ___bpf_prog_run(regs, insn, stack); \ | |
1370 | } | |
1371 | ||
b870aa90 AS |
1372 | #define EVAL1(FN, X) FN(X) |
1373 | #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y) | |
1374 | #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y) | |
1375 | #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y) | |
1376 | #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y) | |
1377 | #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y) | |
1378 | ||
1379 | EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192); | |
1380 | EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384); | |
1381 | EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512); | |
1382 | ||
1ea47e01 AS |
1383 | EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192); |
1384 | EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384); | |
1385 | EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512); | |
1386 | ||
b870aa90 AS |
1387 | #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size), |
1388 | ||
1389 | static unsigned int (*interpreters[])(const void *ctx, | |
1390 | const struct bpf_insn *insn) = { | |
1391 | EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) | |
1392 | EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) | |
1393 | EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) | |
1394 | }; | |
1ea47e01 AS |
1395 | #undef PROG_NAME_LIST |
1396 | #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size), | |
1397 | static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, | |
1398 | const struct bpf_insn *insn) = { | |
1399 | EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) | |
1400 | EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) | |
1401 | EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) | |
1402 | }; | |
1403 | #undef PROG_NAME_LIST | |
1404 | ||
1405 | void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth) | |
1406 | { | |
1407 | stack_depth = max_t(u32, stack_depth, 1); | |
1408 | insn->off = (s16) insn->imm; | |
1409 | insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] - | |
1410 | __bpf_call_base_args; | |
1411 | insn->code = BPF_JMP | BPF_CALL_ARGS; | |
1412 | } | |
b870aa90 | 1413 | |
290af866 | 1414 | #else |
fa9dd599 DB |
1415 | static unsigned int __bpf_prog_ret0_warn(const void *ctx, |
1416 | const struct bpf_insn *insn) | |
290af866 | 1417 | { |
fa9dd599 DB |
1418 | /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON |
1419 | * is not working properly, so warn about it! | |
1420 | */ | |
1421 | WARN_ON_ONCE(1); | |
290af866 AS |
1422 | return 0; |
1423 | } | |
1424 | #endif | |
1425 | ||
3324b584 DB |
1426 | bool bpf_prog_array_compatible(struct bpf_array *array, |
1427 | const struct bpf_prog *fp) | |
04fd61ab | 1428 | { |
9802d865 JB |
1429 | if (fp->kprobe_override) |
1430 | return false; | |
1431 | ||
3324b584 DB |
1432 | if (!array->owner_prog_type) { |
1433 | /* There's no owner yet where we could check for | |
1434 | * compatibility. | |
1435 | */ | |
04fd61ab AS |
1436 | array->owner_prog_type = fp->type; |
1437 | array->owner_jited = fp->jited; | |
3324b584 DB |
1438 | |
1439 | return true; | |
04fd61ab | 1440 | } |
3324b584 DB |
1441 | |
1442 | return array->owner_prog_type == fp->type && | |
1443 | array->owner_jited == fp->jited; | |
04fd61ab AS |
1444 | } |
1445 | ||
3324b584 | 1446 | static int bpf_check_tail_call(const struct bpf_prog *fp) |
04fd61ab AS |
1447 | { |
1448 | struct bpf_prog_aux *aux = fp->aux; | |
1449 | int i; | |
1450 | ||
1451 | for (i = 0; i < aux->used_map_cnt; i++) { | |
3324b584 | 1452 | struct bpf_map *map = aux->used_maps[i]; |
04fd61ab | 1453 | struct bpf_array *array; |
04fd61ab | 1454 | |
04fd61ab AS |
1455 | if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) |
1456 | continue; | |
3324b584 | 1457 | |
04fd61ab AS |
1458 | array = container_of(map, struct bpf_array, map); |
1459 | if (!bpf_prog_array_compatible(array, fp)) | |
1460 | return -EINVAL; | |
1461 | } | |
1462 | ||
1463 | return 0; | |
1464 | } | |
1465 | ||
f5bffecd | 1466 | /** |
3324b584 | 1467 | * bpf_prog_select_runtime - select exec runtime for BPF program |
7ae457c1 | 1468 | * @fp: bpf_prog populated with internal BPF program |
d1c55ab5 | 1469 | * @err: pointer to error variable |
f5bffecd | 1470 | * |
3324b584 DB |
1471 | * Try to JIT eBPF program, if JIT is not available, use interpreter. |
1472 | * The BPF program will be executed via BPF_PROG_RUN() macro. | |
f5bffecd | 1473 | */ |
d1c55ab5 | 1474 | struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) |
f5bffecd | 1475 | { |
290af866 | 1476 | #ifndef CONFIG_BPF_JIT_ALWAYS_ON |
8007e40a MKL |
1477 | u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1); |
1478 | ||
1479 | fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1]; | |
290af866 | 1480 | #else |
fa9dd599 | 1481 | fp->bpf_func = __bpf_prog_ret0_warn; |
290af866 | 1482 | #endif |
f5bffecd | 1483 | |
d1c55ab5 DB |
1484 | /* eBPF JITs can rewrite the program in case constant |
1485 | * blinding is active. However, in case of error during | |
1486 | * blinding, bpf_int_jit_compile() must always return a | |
1487 | * valid program, which in this case would simply not | |
1488 | * be JITed, but falls back to the interpreter. | |
1489 | */ | |
ab3f0063 JK |
1490 | if (!bpf_prog_is_dev_bound(fp->aux)) { |
1491 | fp = bpf_int_jit_compile(fp); | |
290af866 AS |
1492 | #ifdef CONFIG_BPF_JIT_ALWAYS_ON |
1493 | if (!fp->jited) { | |
1494 | *err = -ENOTSUPP; | |
1495 | return fp; | |
1496 | } | |
1497 | #endif | |
ab3f0063 JK |
1498 | } else { |
1499 | *err = bpf_prog_offload_compile(fp); | |
1500 | if (*err) | |
1501 | return fp; | |
1502 | } | |
60a3b225 | 1503 | bpf_prog_lock_ro(fp); |
04fd61ab | 1504 | |
3324b584 DB |
1505 | /* The tail call compatibility check can only be done at |
1506 | * this late stage as we need to determine, if we deal | |
1507 | * with JITed or non JITed program concatenations and not | |
1508 | * all eBPF JITs might immediately support all features. | |
1509 | */ | |
d1c55ab5 DB |
1510 | *err = bpf_check_tail_call(fp); |
1511 | ||
1512 | return fp; | |
f5bffecd | 1513 | } |
7ae457c1 | 1514 | EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
f5bffecd | 1515 | |
e87c6bc3 YS |
1516 | static unsigned int __bpf_prog_ret1(const void *ctx, |
1517 | const struct bpf_insn *insn) | |
1518 | { | |
1519 | return 1; | |
1520 | } | |
1521 | ||
1522 | static struct bpf_prog_dummy { | |
1523 | struct bpf_prog prog; | |
1524 | } dummy_bpf_prog = { | |
1525 | .prog = { | |
1526 | .bpf_func = __bpf_prog_ret1, | |
1527 | }, | |
1528 | }; | |
1529 | ||
324bda9e AS |
1530 | /* to avoid allocating empty bpf_prog_array for cgroups that |
1531 | * don't have bpf program attached use one global 'empty_prog_array' | |
1532 | * It will not be modified the caller of bpf_prog_array_alloc() | |
1533 | * (since caller requested prog_cnt == 0) | |
1534 | * that pointer should be 'freed' by bpf_prog_array_free() | |
1535 | */ | |
1536 | static struct { | |
1537 | struct bpf_prog_array hdr; | |
1538 | struct bpf_prog *null_prog; | |
1539 | } empty_prog_array = { | |
1540 | .null_prog = NULL, | |
1541 | }; | |
1542 | ||
1543 | struct bpf_prog_array __rcu *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags) | |
1544 | { | |
1545 | if (prog_cnt) | |
1546 | return kzalloc(sizeof(struct bpf_prog_array) + | |
1547 | sizeof(struct bpf_prog *) * (prog_cnt + 1), | |
1548 | flags); | |
1549 | ||
1550 | return &empty_prog_array.hdr; | |
1551 | } | |
1552 | ||
1553 | void bpf_prog_array_free(struct bpf_prog_array __rcu *progs) | |
1554 | { | |
1555 | if (!progs || | |
1556 | progs == (struct bpf_prog_array __rcu *)&empty_prog_array.hdr) | |
1557 | return; | |
1558 | kfree_rcu(progs, rcu); | |
1559 | } | |
1560 | ||
468e2f64 AS |
1561 | int bpf_prog_array_length(struct bpf_prog_array __rcu *progs) |
1562 | { | |
1563 | struct bpf_prog **prog; | |
1564 | u32 cnt = 0; | |
1565 | ||
1566 | rcu_read_lock(); | |
1567 | prog = rcu_dereference(progs)->progs; | |
1568 | for (; *prog; prog++) | |
c8c088ba YS |
1569 | if (*prog != &dummy_bpf_prog.prog) |
1570 | cnt++; | |
468e2f64 AS |
1571 | rcu_read_unlock(); |
1572 | return cnt; | |
1573 | } | |
1574 | ||
1575 | int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs, | |
1576 | __u32 __user *prog_ids, u32 cnt) | |
1577 | { | |
1578 | struct bpf_prog **prog; | |
0911287c AS |
1579 | unsigned long err = 0; |
1580 | u32 i = 0, *ids; | |
1581 | bool nospc; | |
1582 | ||
1583 | /* users of this function are doing: | |
1584 | * cnt = bpf_prog_array_length(); | |
1585 | * if (cnt > 0) | |
1586 | * bpf_prog_array_copy_to_user(..., cnt); | |
1587 | * so below kcalloc doesn't need extra cnt > 0 check, but | |
1588 | * bpf_prog_array_length() releases rcu lock and | |
1589 | * prog array could have been swapped with empty or larger array, | |
1590 | * so always copy 'cnt' prog_ids to the user. | |
1591 | * In a rare race the user will see zero prog_ids | |
1592 | */ | |
1593 | ids = kcalloc(cnt, sizeof(u32), GFP_USER); | |
1594 | if (!ids) | |
1595 | return -ENOMEM; | |
468e2f64 AS |
1596 | rcu_read_lock(); |
1597 | prog = rcu_dereference(progs)->progs; | |
1598 | for (; *prog; prog++) { | |
f371b304 YS |
1599 | if (*prog == &dummy_bpf_prog.prog) |
1600 | continue; | |
0911287c | 1601 | ids[i] = (*prog)->aux->id; |
468e2f64 AS |
1602 | if (++i == cnt) { |
1603 | prog++; | |
1604 | break; | |
1605 | } | |
1606 | } | |
0911287c | 1607 | nospc = !!(*prog); |
468e2f64 | 1608 | rcu_read_unlock(); |
0911287c AS |
1609 | err = copy_to_user(prog_ids, ids, cnt * sizeof(u32)); |
1610 | kfree(ids); | |
1611 | if (err) | |
1612 | return -EFAULT; | |
1613 | if (nospc) | |
468e2f64 AS |
1614 | return -ENOSPC; |
1615 | return 0; | |
1616 | } | |
1617 | ||
e87c6bc3 YS |
1618 | void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *progs, |
1619 | struct bpf_prog *old_prog) | |
1620 | { | |
1621 | struct bpf_prog **prog = progs->progs; | |
1622 | ||
1623 | for (; *prog; prog++) | |
1624 | if (*prog == old_prog) { | |
1625 | WRITE_ONCE(*prog, &dummy_bpf_prog.prog); | |
1626 | break; | |
1627 | } | |
1628 | } | |
1629 | ||
1630 | int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, | |
1631 | struct bpf_prog *exclude_prog, | |
1632 | struct bpf_prog *include_prog, | |
1633 | struct bpf_prog_array **new_array) | |
1634 | { | |
1635 | int new_prog_cnt, carry_prog_cnt = 0; | |
1636 | struct bpf_prog **existing_prog; | |
1637 | struct bpf_prog_array *array; | |
1638 | int new_prog_idx = 0; | |
1639 | ||
1640 | /* Figure out how many existing progs we need to carry over to | |
1641 | * the new array. | |
1642 | */ | |
1643 | if (old_array) { | |
1644 | existing_prog = old_array->progs; | |
1645 | for (; *existing_prog; existing_prog++) { | |
1646 | if (*existing_prog != exclude_prog && | |
1647 | *existing_prog != &dummy_bpf_prog.prog) | |
1648 | carry_prog_cnt++; | |
1649 | if (*existing_prog == include_prog) | |
1650 | return -EEXIST; | |
1651 | } | |
1652 | } | |
1653 | ||
1654 | /* How many progs (not NULL) will be in the new array? */ | |
1655 | new_prog_cnt = carry_prog_cnt; | |
1656 | if (include_prog) | |
1657 | new_prog_cnt += 1; | |
1658 | ||
1659 | /* Do we have any prog (not NULL) in the new array? */ | |
1660 | if (!new_prog_cnt) { | |
1661 | *new_array = NULL; | |
1662 | return 0; | |
1663 | } | |
1664 | ||
1665 | /* +1 as the end of prog_array is marked with NULL */ | |
1666 | array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); | |
1667 | if (!array) | |
1668 | return -ENOMEM; | |
1669 | ||
1670 | /* Fill in the new prog array */ | |
1671 | if (carry_prog_cnt) { | |
1672 | existing_prog = old_array->progs; | |
1673 | for (; *existing_prog; existing_prog++) | |
1674 | if (*existing_prog != exclude_prog && | |
1675 | *existing_prog != &dummy_bpf_prog.prog) | |
1676 | array->progs[new_prog_idx++] = *existing_prog; | |
1677 | } | |
1678 | if (include_prog) | |
1679 | array->progs[new_prog_idx++] = include_prog; | |
1680 | array->progs[new_prog_idx] = NULL; | |
1681 | *new_array = array; | |
1682 | return 0; | |
1683 | } | |
1684 | ||
f371b304 YS |
1685 | int bpf_prog_array_copy_info(struct bpf_prog_array __rcu *array, |
1686 | __u32 __user *prog_ids, u32 request_cnt, | |
1687 | __u32 __user *prog_cnt) | |
1688 | { | |
1689 | u32 cnt = 0; | |
1690 | ||
1691 | if (array) | |
1692 | cnt = bpf_prog_array_length(array); | |
1693 | ||
1694 | if (copy_to_user(prog_cnt, &cnt, sizeof(cnt))) | |
1695 | return -EFAULT; | |
1696 | ||
1697 | /* return early if user requested only program count or nothing to copy */ | |
1698 | if (!request_cnt || !cnt) | |
1699 | return 0; | |
1700 | ||
1701 | return bpf_prog_array_copy_to_user(array, prog_ids, request_cnt); | |
1702 | } | |
1703 | ||
60a3b225 DB |
1704 | static void bpf_prog_free_deferred(struct work_struct *work) |
1705 | { | |
09756af4 | 1706 | struct bpf_prog_aux *aux; |
1c2a088a | 1707 | int i; |
60a3b225 | 1708 | |
09756af4 | 1709 | aux = container_of(work, struct bpf_prog_aux, work); |
ab3f0063 JK |
1710 | if (bpf_prog_is_dev_bound(aux)) |
1711 | bpf_prog_offload_destroy(aux->prog); | |
1c2a088a AS |
1712 | for (i = 0; i < aux->func_cnt; i++) |
1713 | bpf_jit_free(aux->func[i]); | |
1714 | if (aux->func_cnt) { | |
1715 | kfree(aux->func); | |
1716 | bpf_prog_unlock_free(aux->prog); | |
1717 | } else { | |
1718 | bpf_jit_free(aux->prog); | |
1719 | } | |
60a3b225 DB |
1720 | } |
1721 | ||
1722 | /* Free internal BPF program */ | |
7ae457c1 | 1723 | void bpf_prog_free(struct bpf_prog *fp) |
f5bffecd | 1724 | { |
09756af4 | 1725 | struct bpf_prog_aux *aux = fp->aux; |
60a3b225 | 1726 | |
09756af4 | 1727 | INIT_WORK(&aux->work, bpf_prog_free_deferred); |
09756af4 | 1728 | schedule_work(&aux->work); |
f5bffecd | 1729 | } |
7ae457c1 | 1730 | EXPORT_SYMBOL_GPL(bpf_prog_free); |
f89b7755 | 1731 | |
3ad00405 DB |
1732 | /* RNG for unpriviledged user space with separated state from prandom_u32(). */ |
1733 | static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); | |
1734 | ||
1735 | void bpf_user_rnd_init_once(void) | |
1736 | { | |
1737 | prandom_init_once(&bpf_user_rnd_state); | |
1738 | } | |
1739 | ||
f3694e00 | 1740 | BPF_CALL_0(bpf_user_rnd_u32) |
3ad00405 DB |
1741 | { |
1742 | /* Should someone ever have the rather unwise idea to use some | |
1743 | * of the registers passed into this function, then note that | |
1744 | * this function is called from native eBPF and classic-to-eBPF | |
1745 | * transformations. Register assignments from both sides are | |
1746 | * different, f.e. classic always sets fn(ctx, A, X) here. | |
1747 | */ | |
1748 | struct rnd_state *state; | |
1749 | u32 res; | |
1750 | ||
1751 | state = &get_cpu_var(bpf_user_rnd_state); | |
1752 | res = prandom_u32_state(state); | |
b761fe22 | 1753 | put_cpu_var(bpf_user_rnd_state); |
3ad00405 DB |
1754 | |
1755 | return res; | |
1756 | } | |
1757 | ||
3ba67dab DB |
1758 | /* Weak definitions of helper functions in case we don't have bpf syscall. */ |
1759 | const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; | |
1760 | const struct bpf_func_proto bpf_map_update_elem_proto __weak; | |
1761 | const struct bpf_func_proto bpf_map_delete_elem_proto __weak; | |
1762 | ||
03e69b50 | 1763 | const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; |
c04167ce | 1764 | const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; |
2d0e30c3 | 1765 | const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; |
17ca8cbf | 1766 | const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; |
bd570ff9 | 1767 | |
ffeedafb AS |
1768 | const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; |
1769 | const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; | |
1770 | const struct bpf_func_proto bpf_get_current_comm_proto __weak; | |
6bdc9c4c | 1771 | const struct bpf_func_proto bpf_sock_map_update_proto __weak; |
bd570ff9 | 1772 | |
0756ea3e AS |
1773 | const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) |
1774 | { | |
1775 | return NULL; | |
1776 | } | |
03e69b50 | 1777 | |
555c8a86 DB |
1778 | u64 __weak |
1779 | bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, | |
1780 | void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) | |
bd570ff9 | 1781 | { |
555c8a86 | 1782 | return -ENOTSUPP; |
bd570ff9 DB |
1783 | } |
1784 | ||
3324b584 DB |
1785 | /* Always built-in helper functions. */ |
1786 | const struct bpf_func_proto bpf_tail_call_proto = { | |
1787 | .func = NULL, | |
1788 | .gpl_only = false, | |
1789 | .ret_type = RET_VOID, | |
1790 | .arg1_type = ARG_PTR_TO_CTX, | |
1791 | .arg2_type = ARG_CONST_MAP_PTR, | |
1792 | .arg3_type = ARG_ANYTHING, | |
1793 | }; | |
1794 | ||
9383191d DB |
1795 | /* Stub for JITs that only support cBPF. eBPF programs are interpreted. |
1796 | * It is encouraged to implement bpf_int_jit_compile() instead, so that | |
1797 | * eBPF and implicitly also cBPF can get JITed! | |
1798 | */ | |
d1c55ab5 | 1799 | struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog) |
3324b584 | 1800 | { |
d1c55ab5 | 1801 | return prog; |
3324b584 DB |
1802 | } |
1803 | ||
9383191d DB |
1804 | /* Stub for JITs that support eBPF. All cBPF code gets transformed into |
1805 | * eBPF by the kernel and is later compiled by bpf_int_jit_compile(). | |
1806 | */ | |
1807 | void __weak bpf_jit_compile(struct bpf_prog *prog) | |
1808 | { | |
1809 | } | |
1810 | ||
17bedab2 | 1811 | bool __weak bpf_helper_changes_pkt_data(void *func) |
969bf05e AS |
1812 | { |
1813 | return false; | |
1814 | } | |
1815 | ||
f89b7755 AS |
1816 | /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call |
1817 | * skb_copy_bits(), so provide a weak definition of it for NET-less config. | |
1818 | */ | |
1819 | int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, | |
1820 | int len) | |
1821 | { | |
1822 | return -EFAULT; | |
1823 | } | |
a67edbf4 DB |
1824 | |
1825 | /* All definitions of tracepoints related to BPF. */ | |
1826 | #define CREATE_TRACE_POINTS | |
1827 | #include <linux/bpf_trace.h> | |
1828 | ||
1829 | EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); | |
1830 | ||
9185a610 SRV |
1831 | /* These are only used within the BPF_SYSCALL code */ |
1832 | #ifdef CONFIG_BPF_SYSCALL | |
a67edbf4 DB |
1833 | EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_get_type); |
1834 | EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_put_rcu); | |
9185a610 | 1835 | #endif |