2 * Linux Socket Filter - Kernel level socket filtering
4 * Based on the design of the Berkeley Packet Filter. The new
5 * internal format has been designed by PLUMgrid:
7 * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
11 * Jay Schulist <jschlst@samba.org>
12 * Alexei Starovoitov <ast@plumgrid.com>
13 * Daniel Borkmann <dborkman@redhat.com>
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.
20 * Andi Kleen - Fix a few bad bugs and races.
21 * Kris Katterjohn - Added many additional checks in bpf_check_classic()
24 #include <linux/filter.h>
25 #include <linux/skbuff.h>
26 #include <linux/vmalloc.h>
27 #include <linux/random.h>
28 #include <linux/moduleloader.h>
29 #include <linux/bpf.h>
30 #include <linux/frame.h>
32 #include <asm/unaligned.h>
35 #define BPF_R0 regs[BPF_REG_0]
36 #define BPF_R1 regs[BPF_REG_1]
37 #define BPF_R2 regs[BPF_REG_2]
38 #define BPF_R3 regs[BPF_REG_3]
39 #define BPF_R4 regs[BPF_REG_4]
40 #define BPF_R5 regs[BPF_REG_5]
41 #define BPF_R6 regs[BPF_REG_6]
42 #define BPF_R7 regs[BPF_REG_7]
43 #define BPF_R8 regs[BPF_REG_8]
44 #define BPF_R9 regs[BPF_REG_9]
45 #define BPF_R10 regs[BPF_REG_10]
48 #define DST regs[insn->dst_reg]
49 #define SRC regs[insn->src_reg]
50 #define FP regs[BPF_REG_FP]
51 #define ARG1 regs[BPF_REG_ARG1]
52 #define CTX regs[BPF_REG_CTX]
55 /* No hurry in this branch
57 * Exported for the bpf jit load helper.
59 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff
*skb
, int k
, unsigned int size
)
64 ptr
= skb_network_header(skb
) + k
- SKF_NET_OFF
;
65 else if (k
>= SKF_LL_OFF
)
66 ptr
= skb_mac_header(skb
) + k
- SKF_LL_OFF
;
68 if (ptr
>= skb
->head
&& ptr
+ size
<= skb_tail_pointer(skb
))
74 struct bpf_prog
*bpf_prog_alloc(unsigned int size
, gfp_t gfp_extra_flags
)
76 gfp_t gfp_flags
= GFP_KERNEL
| __GFP_HIGHMEM
| __GFP_ZERO
|
78 struct bpf_prog_aux
*aux
;
81 size
= round_up(size
, PAGE_SIZE
);
82 fp
= __vmalloc(size
, gfp_flags
, PAGE_KERNEL
);
86 kmemcheck_annotate_bitfield(fp
, meta
);
88 aux
= kzalloc(sizeof(*aux
), GFP_KERNEL
| gfp_extra_flags
);
94 fp
->pages
= size
/ PAGE_SIZE
;
100 EXPORT_SYMBOL_GPL(bpf_prog_alloc
);
102 struct bpf_prog
*bpf_prog_realloc(struct bpf_prog
*fp_old
, unsigned int size
,
103 gfp_t gfp_extra_flags
)
105 gfp_t gfp_flags
= GFP_KERNEL
| __GFP_HIGHMEM
| __GFP_ZERO
|
111 BUG_ON(fp_old
== NULL
);
113 size
= round_up(size
, PAGE_SIZE
);
114 pages
= size
/ PAGE_SIZE
;
115 if (pages
<= fp_old
->pages
)
118 delta
= pages
- fp_old
->pages
;
119 ret
= __bpf_prog_charge(fp_old
->aux
->user
, delta
);
123 fp
= __vmalloc(size
, gfp_flags
, PAGE_KERNEL
);
125 __bpf_prog_uncharge(fp_old
->aux
->user
, delta
);
127 kmemcheck_annotate_bitfield(fp
, meta
);
129 memcpy(fp
, fp_old
, fp_old
->pages
* PAGE_SIZE
);
133 /* We keep fp->aux from fp_old around in the new
134 * reallocated structure.
137 __bpf_prog_free(fp_old
);
143 void __bpf_prog_free(struct bpf_prog
*fp
)
149 int bpf_prog_calc_digest(struct bpf_prog
*fp
)
151 const u32 bits_offset
= SHA_MESSAGE_BYTES
- sizeof(__be64
);
152 u32 raw_size
= bpf_prog_digest_scratch_size(fp
);
153 u32 ws
[SHA_WORKSPACE_WORDS
];
154 u32 i
, bsize
, psize
, blocks
;
155 struct bpf_insn
*dst
;
161 raw
= vmalloc(raw_size
);
165 sha_init(fp
->digest
);
166 memset(ws
, 0, sizeof(ws
));
168 /* We need to take out the map fd for the digest calculation
169 * since they are unstable from user space side.
172 for (i
= 0, was_ld_map
= false; i
< fp
->len
; i
++) {
173 dst
[i
] = fp
->insnsi
[i
];
175 dst
[i
].code
== (BPF_LD
| BPF_IMM
| BPF_DW
) &&
176 dst
[i
].src_reg
== BPF_PSEUDO_MAP_FD
) {
179 } else if (was_ld_map
&&
181 dst
[i
].dst_reg
== 0 &&
182 dst
[i
].src_reg
== 0 &&
191 psize
= bpf_prog_insn_size(fp
);
192 memset(&raw
[psize
], 0, raw_size
- psize
);
195 bsize
= round_up(psize
, SHA_MESSAGE_BYTES
);
196 blocks
= bsize
/ SHA_MESSAGE_BYTES
;
198 if (bsize
- psize
>= sizeof(__be64
)) {
199 bits
= (__be64
*)(todo
+ bsize
- sizeof(__be64
));
201 bits
= (__be64
*)(todo
+ bsize
+ bits_offset
);
204 *bits
= cpu_to_be64((psize
- 1) << 3);
207 sha_transform(fp
->digest
, todo
, ws
);
208 todo
+= SHA_MESSAGE_BYTES
;
211 result
= (__force __be32
*)fp
->digest
;
212 for (i
= 0; i
< SHA_DIGEST_WORDS
; i
++)
213 result
[i
] = cpu_to_be32(fp
->digest
[i
]);
219 static bool bpf_is_jmp_and_has_target(const struct bpf_insn
*insn
)
221 return BPF_CLASS(insn
->code
) == BPF_JMP
&&
222 /* Call and Exit are both special jumps with no
223 * target inside the BPF instruction image.
225 BPF_OP(insn
->code
) != BPF_CALL
&&
226 BPF_OP(insn
->code
) != BPF_EXIT
;
229 static void bpf_adj_branches(struct bpf_prog
*prog
, u32 pos
, u32 delta
)
231 struct bpf_insn
*insn
= prog
->insnsi
;
232 u32 i
, insn_cnt
= prog
->len
;
234 for (i
= 0; i
< insn_cnt
; i
++, insn
++) {
235 if (!bpf_is_jmp_and_has_target(insn
))
238 /* Adjust offset of jmps if we cross boundaries. */
239 if (i
< pos
&& i
+ insn
->off
+ 1 > pos
)
241 else if (i
> pos
+ delta
&& i
+ insn
->off
+ 1 <= pos
+ delta
)
246 struct bpf_prog
*bpf_patch_insn_single(struct bpf_prog
*prog
, u32 off
,
247 const struct bpf_insn
*patch
, u32 len
)
249 u32 insn_adj_cnt
, insn_rest
, insn_delta
= len
- 1;
250 struct bpf_prog
*prog_adj
;
252 /* Since our patchlet doesn't expand the image, we're done. */
253 if (insn_delta
== 0) {
254 memcpy(prog
->insnsi
+ off
, patch
, sizeof(*patch
));
258 insn_adj_cnt
= prog
->len
+ insn_delta
;
260 /* Several new instructions need to be inserted. Make room
261 * for them. Likely, there's no need for a new allocation as
262 * last page could have large enough tailroom.
264 prog_adj
= bpf_prog_realloc(prog
, bpf_prog_size(insn_adj_cnt
),
269 prog_adj
->len
= insn_adj_cnt
;
271 /* Patching happens in 3 steps:
273 * 1) Move over tail of insnsi from next instruction onwards,
274 * so we can patch the single target insn with one or more
275 * new ones (patching is always from 1 to n insns, n > 0).
276 * 2) Inject new instructions at the target location.
277 * 3) Adjust branch offsets if necessary.
279 insn_rest
= insn_adj_cnt
- off
- len
;
281 memmove(prog_adj
->insnsi
+ off
+ len
, prog_adj
->insnsi
+ off
+ 1,
282 sizeof(*patch
) * insn_rest
);
283 memcpy(prog_adj
->insnsi
+ off
, patch
, sizeof(*patch
) * len
);
285 bpf_adj_branches(prog_adj
, off
, insn_delta
);
290 #ifdef CONFIG_BPF_JIT
291 struct bpf_binary_header
*
292 bpf_jit_binary_alloc(unsigned int proglen
, u8
**image_ptr
,
293 unsigned int alignment
,
294 bpf_jit_fill_hole_t bpf_fill_ill_insns
)
296 struct bpf_binary_header
*hdr
;
297 unsigned int size
, hole
, start
;
299 /* Most of BPF filters are really small, but if some of them
300 * fill a page, allow at least 128 extra bytes to insert a
301 * random section of illegal instructions.
303 size
= round_up(proglen
+ sizeof(*hdr
) + 128, PAGE_SIZE
);
304 hdr
= module_alloc(size
);
308 /* Fill space with illegal/arch-dep instructions. */
309 bpf_fill_ill_insns(hdr
, size
);
311 hdr
->pages
= size
/ PAGE_SIZE
;
312 hole
= min_t(unsigned int, size
- (proglen
+ sizeof(*hdr
)),
313 PAGE_SIZE
- sizeof(*hdr
));
314 start
= (get_random_int() % hole
) & ~(alignment
- 1);
316 /* Leave a random number of instructions before BPF code. */
317 *image_ptr
= &hdr
->image
[start
];
322 void bpf_jit_binary_free(struct bpf_binary_header
*hdr
)
327 int bpf_jit_harden __read_mostly
;
329 static int bpf_jit_blind_insn(const struct bpf_insn
*from
,
330 const struct bpf_insn
*aux
,
331 struct bpf_insn
*to_buff
)
333 struct bpf_insn
*to
= to_buff
;
334 u32 imm_rnd
= get_random_int();
337 BUILD_BUG_ON(BPF_REG_AX
+ 1 != MAX_BPF_JIT_REG
);
338 BUILD_BUG_ON(MAX_BPF_REG
+ 1 != MAX_BPF_JIT_REG
);
340 if (from
->imm
== 0 &&
341 (from
->code
== (BPF_ALU
| BPF_MOV
| BPF_K
) ||
342 from
->code
== (BPF_ALU64
| BPF_MOV
| BPF_K
))) {
343 *to
++ = BPF_ALU64_REG(BPF_XOR
, from
->dst_reg
, from
->dst_reg
);
347 switch (from
->code
) {
348 case BPF_ALU
| BPF_ADD
| BPF_K
:
349 case BPF_ALU
| BPF_SUB
| BPF_K
:
350 case BPF_ALU
| BPF_AND
| BPF_K
:
351 case BPF_ALU
| BPF_OR
| BPF_K
:
352 case BPF_ALU
| BPF_XOR
| BPF_K
:
353 case BPF_ALU
| BPF_MUL
| BPF_K
:
354 case BPF_ALU
| BPF_MOV
| BPF_K
:
355 case BPF_ALU
| BPF_DIV
| BPF_K
:
356 case BPF_ALU
| BPF_MOD
| BPF_K
:
357 *to
++ = BPF_ALU32_IMM(BPF_MOV
, BPF_REG_AX
, imm_rnd
^ from
->imm
);
358 *to
++ = BPF_ALU32_IMM(BPF_XOR
, BPF_REG_AX
, imm_rnd
);
359 *to
++ = BPF_ALU32_REG(from
->code
, from
->dst_reg
, BPF_REG_AX
);
362 case BPF_ALU64
| BPF_ADD
| BPF_K
:
363 case BPF_ALU64
| BPF_SUB
| BPF_K
:
364 case BPF_ALU64
| BPF_AND
| BPF_K
:
365 case BPF_ALU64
| BPF_OR
| BPF_K
:
366 case BPF_ALU64
| BPF_XOR
| BPF_K
:
367 case BPF_ALU64
| BPF_MUL
| BPF_K
:
368 case BPF_ALU64
| BPF_MOV
| BPF_K
:
369 case BPF_ALU64
| BPF_DIV
| BPF_K
:
370 case BPF_ALU64
| BPF_MOD
| BPF_K
:
371 *to
++ = BPF_ALU64_IMM(BPF_MOV
, BPF_REG_AX
, imm_rnd
^ from
->imm
);
372 *to
++ = BPF_ALU64_IMM(BPF_XOR
, BPF_REG_AX
, imm_rnd
);
373 *to
++ = BPF_ALU64_REG(from
->code
, from
->dst_reg
, BPF_REG_AX
);
376 case BPF_JMP
| BPF_JEQ
| BPF_K
:
377 case BPF_JMP
| BPF_JNE
| BPF_K
:
378 case BPF_JMP
| BPF_JGT
| BPF_K
:
379 case BPF_JMP
| BPF_JGE
| BPF_K
:
380 case BPF_JMP
| BPF_JSGT
| BPF_K
:
381 case BPF_JMP
| BPF_JSGE
| BPF_K
:
382 case BPF_JMP
| BPF_JSET
| BPF_K
:
383 /* Accommodate for extra offset in case of a backjump. */
387 *to
++ = BPF_ALU64_IMM(BPF_MOV
, BPF_REG_AX
, imm_rnd
^ from
->imm
);
388 *to
++ = BPF_ALU64_IMM(BPF_XOR
, BPF_REG_AX
, imm_rnd
);
389 *to
++ = BPF_JMP_REG(from
->code
, from
->dst_reg
, BPF_REG_AX
, off
);
392 case BPF_LD
| BPF_ABS
| BPF_W
:
393 case BPF_LD
| BPF_ABS
| BPF_H
:
394 case BPF_LD
| BPF_ABS
| BPF_B
:
395 *to
++ = BPF_ALU64_IMM(BPF_MOV
, BPF_REG_AX
, imm_rnd
^ from
->imm
);
396 *to
++ = BPF_ALU64_IMM(BPF_XOR
, BPF_REG_AX
, imm_rnd
);
397 *to
++ = BPF_LD_IND(from
->code
, BPF_REG_AX
, 0);
400 case BPF_LD
| BPF_IND
| BPF_W
:
401 case BPF_LD
| BPF_IND
| BPF_H
:
402 case BPF_LD
| BPF_IND
| BPF_B
:
403 *to
++ = BPF_ALU64_IMM(BPF_MOV
, BPF_REG_AX
, imm_rnd
^ from
->imm
);
404 *to
++ = BPF_ALU64_IMM(BPF_XOR
, BPF_REG_AX
, imm_rnd
);
405 *to
++ = BPF_ALU32_REG(BPF_ADD
, BPF_REG_AX
, from
->src_reg
);
406 *to
++ = BPF_LD_IND(from
->code
, BPF_REG_AX
, 0);
409 case BPF_LD
| BPF_IMM
| BPF_DW
:
410 *to
++ = BPF_ALU64_IMM(BPF_MOV
, BPF_REG_AX
, imm_rnd
^ aux
[1].imm
);
411 *to
++ = BPF_ALU64_IMM(BPF_XOR
, BPF_REG_AX
, imm_rnd
);
412 *to
++ = BPF_ALU64_IMM(BPF_LSH
, BPF_REG_AX
, 32);
413 *to
++ = BPF_ALU64_REG(BPF_MOV
, aux
[0].dst_reg
, BPF_REG_AX
);
415 case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
416 *to
++ = BPF_ALU32_IMM(BPF_MOV
, BPF_REG_AX
, imm_rnd
^ aux
[0].imm
);
417 *to
++ = BPF_ALU32_IMM(BPF_XOR
, BPF_REG_AX
, imm_rnd
);
418 *to
++ = BPF_ALU64_REG(BPF_OR
, aux
[0].dst_reg
, BPF_REG_AX
);
421 case BPF_ST
| BPF_MEM
| BPF_DW
:
422 case BPF_ST
| BPF_MEM
| BPF_W
:
423 case BPF_ST
| BPF_MEM
| BPF_H
:
424 case BPF_ST
| BPF_MEM
| BPF_B
:
425 *to
++ = BPF_ALU64_IMM(BPF_MOV
, BPF_REG_AX
, imm_rnd
^ from
->imm
);
426 *to
++ = BPF_ALU64_IMM(BPF_XOR
, BPF_REG_AX
, imm_rnd
);
427 *to
++ = BPF_STX_MEM(from
->code
, from
->dst_reg
, BPF_REG_AX
, from
->off
);
434 static struct bpf_prog
*bpf_prog_clone_create(struct bpf_prog
*fp_other
,
435 gfp_t gfp_extra_flags
)
437 gfp_t gfp_flags
= GFP_KERNEL
| __GFP_HIGHMEM
| __GFP_ZERO
|
441 fp
= __vmalloc(fp_other
->pages
* PAGE_SIZE
, gfp_flags
, PAGE_KERNEL
);
443 kmemcheck_annotate_bitfield(fp
, meta
);
445 /* aux->prog still points to the fp_other one, so
446 * when promoting the clone to the real program,
447 * this still needs to be adapted.
449 memcpy(fp
, fp_other
, fp_other
->pages
* PAGE_SIZE
);
455 static void bpf_prog_clone_free(struct bpf_prog
*fp
)
457 /* aux was stolen by the other clone, so we cannot free
458 * it from this path! It will be freed eventually by the
459 * other program on release.
461 * At this point, we don't need a deferred release since
462 * clone is guaranteed to not be locked.
468 void bpf_jit_prog_release_other(struct bpf_prog
*fp
, struct bpf_prog
*fp_other
)
470 /* We have to repoint aux->prog to self, as we don't
471 * know whether fp here is the clone or the original.
474 bpf_prog_clone_free(fp_other
);
477 struct bpf_prog
*bpf_jit_blind_constants(struct bpf_prog
*prog
)
479 struct bpf_insn insn_buff
[16], aux
[2];
480 struct bpf_prog
*clone
, *tmp
;
481 int insn_delta
, insn_cnt
;
482 struct bpf_insn
*insn
;
485 if (!bpf_jit_blinding_enabled())
488 clone
= bpf_prog_clone_create(prog
, GFP_USER
);
490 return ERR_PTR(-ENOMEM
);
492 insn_cnt
= clone
->len
;
493 insn
= clone
->insnsi
;
495 for (i
= 0; i
< insn_cnt
; i
++, insn
++) {
496 /* We temporarily need to hold the original ld64 insn
497 * so that we can still access the first part in the
498 * second blinding run.
500 if (insn
[0].code
== (BPF_LD
| BPF_IMM
| BPF_DW
) &&
502 memcpy(aux
, insn
, sizeof(aux
));
504 rewritten
= bpf_jit_blind_insn(insn
, aux
, insn_buff
);
508 tmp
= bpf_patch_insn_single(clone
, i
, insn_buff
, rewritten
);
510 /* Patching may have repointed aux->prog during
511 * realloc from the original one, so we need to
512 * fix it up here on error.
514 bpf_jit_prog_release_other(prog
, clone
);
515 return ERR_PTR(-ENOMEM
);
519 insn_delta
= rewritten
- 1;
521 /* Walk new program and skip insns we just inserted. */
522 insn
= clone
->insnsi
+ i
+ insn_delta
;
523 insn_cnt
+= insn_delta
;
529 #endif /* CONFIG_BPF_JIT */
531 /* Base function for offset calculation. Needs to go into .text section,
532 * therefore keeping it non-static as well; will also be used by JITs
533 * anyway later on, so do not let the compiler omit it.
535 noinline u64
__bpf_call_base(u64 r1
, u64 r2
, u64 r3
, u64 r4
, u64 r5
)
539 EXPORT_SYMBOL_GPL(__bpf_call_base
);
542 * __bpf_prog_run - run eBPF program on a given context
543 * @ctx: is the data we are operating on
544 * @insn: is the array of eBPF instructions
546 * Decode and execute eBPF instructions.
548 static unsigned int __bpf_prog_run(void *ctx
, const struct bpf_insn
*insn
)
550 u64 stack
[MAX_BPF_STACK
/ sizeof(u64
)];
551 u64 regs
[MAX_BPF_REG
], tmp
;
552 static const void *jumptable
[256] = {
553 [0 ... 255] = &&default_label
,
554 /* Now overwrite non-defaults ... */
555 /* 32 bit ALU operations */
556 [BPF_ALU
| BPF_ADD
| BPF_X
] = &&ALU_ADD_X
,
557 [BPF_ALU
| BPF_ADD
| BPF_K
] = &&ALU_ADD_K
,
558 [BPF_ALU
| BPF_SUB
| BPF_X
] = &&ALU_SUB_X
,
559 [BPF_ALU
| BPF_SUB
| BPF_K
] = &&ALU_SUB_K
,
560 [BPF_ALU
| BPF_AND
| BPF_X
] = &&ALU_AND_X
,
561 [BPF_ALU
| BPF_AND
| BPF_K
] = &&ALU_AND_K
,
562 [BPF_ALU
| BPF_OR
| BPF_X
] = &&ALU_OR_X
,
563 [BPF_ALU
| BPF_OR
| BPF_K
] = &&ALU_OR_K
,
564 [BPF_ALU
| BPF_LSH
| BPF_X
] = &&ALU_LSH_X
,
565 [BPF_ALU
| BPF_LSH
| BPF_K
] = &&ALU_LSH_K
,
566 [BPF_ALU
| BPF_RSH
| BPF_X
] = &&ALU_RSH_X
,
567 [BPF_ALU
| BPF_RSH
| BPF_K
] = &&ALU_RSH_K
,
568 [BPF_ALU
| BPF_XOR
| BPF_X
] = &&ALU_XOR_X
,
569 [BPF_ALU
| BPF_XOR
| BPF_K
] = &&ALU_XOR_K
,
570 [BPF_ALU
| BPF_MUL
| BPF_X
] = &&ALU_MUL_X
,
571 [BPF_ALU
| BPF_MUL
| BPF_K
] = &&ALU_MUL_K
,
572 [BPF_ALU
| BPF_MOV
| BPF_X
] = &&ALU_MOV_X
,
573 [BPF_ALU
| BPF_MOV
| BPF_K
] = &&ALU_MOV_K
,
574 [BPF_ALU
| BPF_DIV
| BPF_X
] = &&ALU_DIV_X
,
575 [BPF_ALU
| BPF_DIV
| BPF_K
] = &&ALU_DIV_K
,
576 [BPF_ALU
| BPF_MOD
| BPF_X
] = &&ALU_MOD_X
,
577 [BPF_ALU
| BPF_MOD
| BPF_K
] = &&ALU_MOD_K
,
578 [BPF_ALU
| BPF_NEG
] = &&ALU_NEG
,
579 [BPF_ALU
| BPF_END
| BPF_TO_BE
] = &&ALU_END_TO_BE
,
580 [BPF_ALU
| BPF_END
| BPF_TO_LE
] = &&ALU_END_TO_LE
,
581 /* 64 bit ALU operations */
582 [BPF_ALU64
| BPF_ADD
| BPF_X
] = &&ALU64_ADD_X
,
583 [BPF_ALU64
| BPF_ADD
| BPF_K
] = &&ALU64_ADD_K
,
584 [BPF_ALU64
| BPF_SUB
| BPF_X
] = &&ALU64_SUB_X
,
585 [BPF_ALU64
| BPF_SUB
| BPF_K
] = &&ALU64_SUB_K
,
586 [BPF_ALU64
| BPF_AND
| BPF_X
] = &&ALU64_AND_X
,
587 [BPF_ALU64
| BPF_AND
| BPF_K
] = &&ALU64_AND_K
,
588 [BPF_ALU64
| BPF_OR
| BPF_X
] = &&ALU64_OR_X
,
589 [BPF_ALU64
| BPF_OR
| BPF_K
] = &&ALU64_OR_K
,
590 [BPF_ALU64
| BPF_LSH
| BPF_X
] = &&ALU64_LSH_X
,
591 [BPF_ALU64
| BPF_LSH
| BPF_K
] = &&ALU64_LSH_K
,
592 [BPF_ALU64
| BPF_RSH
| BPF_X
] = &&ALU64_RSH_X
,
593 [BPF_ALU64
| BPF_RSH
| BPF_K
] = &&ALU64_RSH_K
,
594 [BPF_ALU64
| BPF_XOR
| BPF_X
] = &&ALU64_XOR_X
,
595 [BPF_ALU64
| BPF_XOR
| BPF_K
] = &&ALU64_XOR_K
,
596 [BPF_ALU64
| BPF_MUL
| BPF_X
] = &&ALU64_MUL_X
,
597 [BPF_ALU64
| BPF_MUL
| BPF_K
] = &&ALU64_MUL_K
,
598 [BPF_ALU64
| BPF_MOV
| BPF_X
] = &&ALU64_MOV_X
,
599 [BPF_ALU64
| BPF_MOV
| BPF_K
] = &&ALU64_MOV_K
,
600 [BPF_ALU64
| BPF_ARSH
| BPF_X
] = &&ALU64_ARSH_X
,
601 [BPF_ALU64
| BPF_ARSH
| BPF_K
] = &&ALU64_ARSH_K
,
602 [BPF_ALU64
| BPF_DIV
| BPF_X
] = &&ALU64_DIV_X
,
603 [BPF_ALU64
| BPF_DIV
| BPF_K
] = &&ALU64_DIV_K
,
604 [BPF_ALU64
| BPF_MOD
| BPF_X
] = &&ALU64_MOD_X
,
605 [BPF_ALU64
| BPF_MOD
| BPF_K
] = &&ALU64_MOD_K
,
606 [BPF_ALU64
| BPF_NEG
] = &&ALU64_NEG
,
607 /* Call instruction */
608 [BPF_JMP
| BPF_CALL
] = &&JMP_CALL
,
609 [BPF_JMP
| BPF_CALL
| BPF_X
] = &&JMP_TAIL_CALL
,
611 [BPF_JMP
| BPF_JA
] = &&JMP_JA
,
612 [BPF_JMP
| BPF_JEQ
| BPF_X
] = &&JMP_JEQ_X
,
613 [BPF_JMP
| BPF_JEQ
| BPF_K
] = &&JMP_JEQ_K
,
614 [BPF_JMP
| BPF_JNE
| BPF_X
] = &&JMP_JNE_X
,
615 [BPF_JMP
| BPF_JNE
| BPF_K
] = &&JMP_JNE_K
,
616 [BPF_JMP
| BPF_JGT
| BPF_X
] = &&JMP_JGT_X
,
617 [BPF_JMP
| BPF_JGT
| BPF_K
] = &&JMP_JGT_K
,
618 [BPF_JMP
| BPF_JGE
| BPF_X
] = &&JMP_JGE_X
,
619 [BPF_JMP
| BPF_JGE
| BPF_K
] = &&JMP_JGE_K
,
620 [BPF_JMP
| BPF_JSGT
| BPF_X
] = &&JMP_JSGT_X
,
621 [BPF_JMP
| BPF_JSGT
| BPF_K
] = &&JMP_JSGT_K
,
622 [BPF_JMP
| BPF_JSGE
| BPF_X
] = &&JMP_JSGE_X
,
623 [BPF_JMP
| BPF_JSGE
| BPF_K
] = &&JMP_JSGE_K
,
624 [BPF_JMP
| BPF_JSET
| BPF_X
] = &&JMP_JSET_X
,
625 [BPF_JMP
| BPF_JSET
| BPF_K
] = &&JMP_JSET_K
,
627 [BPF_JMP
| BPF_EXIT
] = &&JMP_EXIT
,
628 /* Store instructions */
629 [BPF_STX
| BPF_MEM
| BPF_B
] = &&STX_MEM_B
,
630 [BPF_STX
| BPF_MEM
| BPF_H
] = &&STX_MEM_H
,
631 [BPF_STX
| BPF_MEM
| BPF_W
] = &&STX_MEM_W
,
632 [BPF_STX
| BPF_MEM
| BPF_DW
] = &&STX_MEM_DW
,
633 [BPF_STX
| BPF_XADD
| BPF_W
] = &&STX_XADD_W
,
634 [BPF_STX
| BPF_XADD
| BPF_DW
] = &&STX_XADD_DW
,
635 [BPF_ST
| BPF_MEM
| BPF_B
] = &&ST_MEM_B
,
636 [BPF_ST
| BPF_MEM
| BPF_H
] = &&ST_MEM_H
,
637 [BPF_ST
| BPF_MEM
| BPF_W
] = &&ST_MEM_W
,
638 [BPF_ST
| BPF_MEM
| BPF_DW
] = &&ST_MEM_DW
,
639 /* Load instructions */
640 [BPF_LDX
| BPF_MEM
| BPF_B
] = &&LDX_MEM_B
,
641 [BPF_LDX
| BPF_MEM
| BPF_H
] = &&LDX_MEM_H
,
642 [BPF_LDX
| BPF_MEM
| BPF_W
] = &&LDX_MEM_W
,
643 [BPF_LDX
| BPF_MEM
| BPF_DW
] = &&LDX_MEM_DW
,
644 [BPF_LD
| BPF_ABS
| BPF_W
] = &&LD_ABS_W
,
645 [BPF_LD
| BPF_ABS
| BPF_H
] = &&LD_ABS_H
,
646 [BPF_LD
| BPF_ABS
| BPF_B
] = &&LD_ABS_B
,
647 [BPF_LD
| BPF_IND
| BPF_W
] = &&LD_IND_W
,
648 [BPF_LD
| BPF_IND
| BPF_H
] = &&LD_IND_H
,
649 [BPF_LD
| BPF_IND
| BPF_B
] = &&LD_IND_B
,
650 [BPF_LD
| BPF_IMM
| BPF_DW
] = &&LD_IMM_DW
,
652 u32 tail_call_cnt
= 0;
656 #define CONT ({ insn++; goto select_insn; })
657 #define CONT_JMP ({ insn++; goto select_insn; })
659 FP
= (u64
) (unsigned long) &stack
[ARRAY_SIZE(stack
)];
660 ARG1
= (u64
) (unsigned long) ctx
;
663 goto *jumptable
[insn
->code
];
666 #define ALU(OPCODE, OP) \
667 ALU64_##OPCODE##_X: \
671 DST = (u32) DST OP (u32) SRC; \
673 ALU64_##OPCODE##_K: \
677 DST = (u32) DST OP (u32) IMM; \
708 DST
= (u64
) (u32
) insn
[0].imm
| ((u64
) (u32
) insn
[1].imm
) << 32;
712 (*(s64
*) &DST
) >>= SRC
;
715 (*(s64
*) &DST
) >>= IMM
;
718 if (unlikely(SRC
== 0))
720 div64_u64_rem(DST
, SRC
, &tmp
);
724 if (unlikely(SRC
== 0))
727 DST
= do_div(tmp
, (u32
) SRC
);
730 div64_u64_rem(DST
, IMM
, &tmp
);
735 DST
= do_div(tmp
, (u32
) IMM
);
738 if (unlikely(SRC
== 0))
740 DST
= div64_u64(DST
, SRC
);
743 if (unlikely(SRC
== 0))
746 do_div(tmp
, (u32
) SRC
);
750 DST
= div64_u64(DST
, IMM
);
754 do_div(tmp
, (u32
) IMM
);
760 DST
= (__force u16
) cpu_to_be16(DST
);
763 DST
= (__force u32
) cpu_to_be32(DST
);
766 DST
= (__force u64
) cpu_to_be64(DST
);
773 DST
= (__force u16
) cpu_to_le16(DST
);
776 DST
= (__force u32
) cpu_to_le32(DST
);
779 DST
= (__force u64
) cpu_to_le64(DST
);
786 /* Function call scratches BPF_R1-BPF_R5 registers,
787 * preserves BPF_R6-BPF_R9, and stores return value
790 BPF_R0
= (__bpf_call_base
+ insn
->imm
)(BPF_R1
, BPF_R2
, BPF_R3
,
795 struct bpf_map
*map
= (struct bpf_map
*) (unsigned long) BPF_R2
;
796 struct bpf_array
*array
= container_of(map
, struct bpf_array
, map
);
797 struct bpf_prog
*prog
;
800 if (unlikely(index
>= array
->map
.max_entries
))
802 if (unlikely(tail_call_cnt
> MAX_TAIL_CALL_CNT
))
807 prog
= READ_ONCE(array
->ptrs
[index
]);
811 /* ARG1 at this point is guaranteed to point to CTX from
812 * the verifier side due to the fact that the tail call is
813 * handeled like a helper, that is, bpf_tail_call_proto,
814 * where arg1_type is ARG_PTR_TO_CTX.
874 if (((s64
) DST
) > ((s64
) SRC
)) {
880 if (((s64
) DST
) > ((s64
) IMM
)) {
886 if (((s64
) DST
) >= ((s64
) SRC
)) {
892 if (((s64
) DST
) >= ((s64
) IMM
)) {
912 /* STX and ST and LDX*/
913 #define LDST(SIZEOP, SIZE) \
915 *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \
918 *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \
921 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \
929 STX_XADD_W
: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
930 atomic_add((u32
) SRC
, (atomic_t
*)(unsigned long)
933 STX_XADD_DW
: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */
934 atomic64_add((u64
) SRC
, (atomic64_t
*)(unsigned long)
937 LD_ABS_W
: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */
940 /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are
941 * only appearing in the programs where ctx ==
942 * skb. All programs keep 'ctx' in regs[BPF_REG_CTX]
943 * == BPF_R6, bpf_convert_filter() saves it in BPF_R6,
944 * internal BPF verifier will check that BPF_R6 ==
947 * BPF_ABS and BPF_IND are wrappers of function calls,
948 * so they scratch BPF_R1-BPF_R5 registers, preserve
949 * BPF_R6-BPF_R9, and store return value into BPF_R0.
952 * ctx == skb == BPF_R6 == CTX
955 * SRC == any register
956 * IMM == 32-bit immediate
959 * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness
962 ptr
= bpf_load_pointer((struct sk_buff
*) (unsigned long) CTX
, off
, 4, &tmp
);
963 if (likely(ptr
!= NULL
)) {
964 BPF_R0
= get_unaligned_be32(ptr
);
969 LD_ABS_H
: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */
972 ptr
= bpf_load_pointer((struct sk_buff
*) (unsigned long) CTX
, off
, 2, &tmp
);
973 if (likely(ptr
!= NULL
)) {
974 BPF_R0
= get_unaligned_be16(ptr
);
979 LD_ABS_B
: /* BPF_R0 = *(u8 *) (skb->data + imm32) */
982 ptr
= bpf_load_pointer((struct sk_buff
*) (unsigned long) CTX
, off
, 1, &tmp
);
983 if (likely(ptr
!= NULL
)) {
989 LD_IND_W
: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */
992 LD_IND_H
: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */
995 LD_IND_B
: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */
1000 /* If we ever reach this, we have a bug somewhere. */
1001 WARN_RATELIMIT(1, "unknown opcode %02x\n", insn
->code
);
1004 STACK_FRAME_NON_STANDARD(__bpf_prog_run
); /* jump table */
1006 bool bpf_prog_array_compatible(struct bpf_array
*array
,
1007 const struct bpf_prog
*fp
)
1009 if (!array
->owner_prog_type
) {
1010 /* There's no owner yet where we could check for
1013 array
->owner_prog_type
= fp
->type
;
1014 array
->owner_jited
= fp
->jited
;
1019 return array
->owner_prog_type
== fp
->type
&&
1020 array
->owner_jited
== fp
->jited
;
1023 static int bpf_check_tail_call(const struct bpf_prog
*fp
)
1025 struct bpf_prog_aux
*aux
= fp
->aux
;
1028 for (i
= 0; i
< aux
->used_map_cnt
; i
++) {
1029 struct bpf_map
*map
= aux
->used_maps
[i
];
1030 struct bpf_array
*array
;
1032 if (map
->map_type
!= BPF_MAP_TYPE_PROG_ARRAY
)
1035 array
= container_of(map
, struct bpf_array
, map
);
1036 if (!bpf_prog_array_compatible(array
, fp
))
1044 * bpf_prog_select_runtime - select exec runtime for BPF program
1045 * @fp: bpf_prog populated with internal BPF program
1046 * @err: pointer to error variable
1048 * Try to JIT eBPF program, if JIT is not available, use interpreter.
1049 * The BPF program will be executed via BPF_PROG_RUN() macro.
1051 struct bpf_prog
*bpf_prog_select_runtime(struct bpf_prog
*fp
, int *err
)
1053 fp
->bpf_func
= (void *) __bpf_prog_run
;
1055 /* eBPF JITs can rewrite the program in case constant
1056 * blinding is active. However, in case of error during
1057 * blinding, bpf_int_jit_compile() must always return a
1058 * valid program, which in this case would simply not
1059 * be JITed, but falls back to the interpreter.
1061 fp
= bpf_int_jit_compile(fp
);
1062 bpf_prog_lock_ro(fp
);
1064 /* The tail call compatibility check can only be done at
1065 * this late stage as we need to determine, if we deal
1066 * with JITed or non JITed program concatenations and not
1067 * all eBPF JITs might immediately support all features.
1069 *err
= bpf_check_tail_call(fp
);
1073 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime
);
1075 static void bpf_prog_free_deferred(struct work_struct
*work
)
1077 struct bpf_prog_aux
*aux
;
1079 aux
= container_of(work
, struct bpf_prog_aux
, work
);
1080 bpf_jit_free(aux
->prog
);
1083 /* Free internal BPF program */
1084 void bpf_prog_free(struct bpf_prog
*fp
)
1086 struct bpf_prog_aux
*aux
= fp
->aux
;
1088 INIT_WORK(&aux
->work
, bpf_prog_free_deferred
);
1089 schedule_work(&aux
->work
);
1091 EXPORT_SYMBOL_GPL(bpf_prog_free
);
1093 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
1094 static DEFINE_PER_CPU(struct rnd_state
, bpf_user_rnd_state
);
1096 void bpf_user_rnd_init_once(void)
1098 prandom_init_once(&bpf_user_rnd_state
);
1101 BPF_CALL_0(bpf_user_rnd_u32
)
1103 /* Should someone ever have the rather unwise idea to use some
1104 * of the registers passed into this function, then note that
1105 * this function is called from native eBPF and classic-to-eBPF
1106 * transformations. Register assignments from both sides are
1107 * different, f.e. classic always sets fn(ctx, A, X) here.
1109 struct rnd_state
*state
;
1112 state
= &get_cpu_var(bpf_user_rnd_state
);
1113 res
= prandom_u32_state(state
);
1114 put_cpu_var(bpf_user_rnd_state
);
1119 /* Weak definitions of helper functions in case we don't have bpf syscall. */
1120 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak
;
1121 const struct bpf_func_proto bpf_map_update_elem_proto __weak
;
1122 const struct bpf_func_proto bpf_map_delete_elem_proto __weak
;
1124 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak
;
1125 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak
;
1126 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak
;
1127 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak
;
1129 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak
;
1130 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak
;
1131 const struct bpf_func_proto bpf_get_current_comm_proto __weak
;
1133 const struct bpf_func_proto
* __weak
bpf_get_trace_printk_proto(void)
1139 bpf_event_output(struct bpf_map
*map
, u64 flags
, void *meta
, u64 meta_size
,
1140 void *ctx
, u64 ctx_size
, bpf_ctx_copy_t ctx_copy
)
1145 /* Always built-in helper functions. */
1146 const struct bpf_func_proto bpf_tail_call_proto
= {
1149 .ret_type
= RET_VOID
,
1150 .arg1_type
= ARG_PTR_TO_CTX
,
1151 .arg2_type
= ARG_CONST_MAP_PTR
,
1152 .arg3_type
= ARG_ANYTHING
,
1155 /* For classic BPF JITs that don't implement bpf_int_jit_compile(). */
1156 struct bpf_prog
* __weak
bpf_int_jit_compile(struct bpf_prog
*prog
)
1161 bool __weak
bpf_helper_changes_pkt_data(void *func
)
1166 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
1167 * skb_copy_bits(), so provide a weak definition of it for NET-less config.
1169 int __weak
skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
,