2 * BPF Jit compiler for s390.
4 * Copyright IBM Corp. 2012
6 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
8 #include <linux/netdevice.h>
9 #include <linux/if_vlan.h>
10 #include <linux/filter.h>
11 #include <linux/init.h>
12 #include <asm/cacheflush.h>
13 #include <asm/facility.h>
19 * %r3 = offset parameter
20 * %r4 = scratch register / length parameter
21 * %r5 = BPF A accumulator
22 * %r8 = return address
23 * %r9 = save register for skb pointer
25 * %r11 = skb->len - skb->data_len (headlen)
26 * %r12 = BPF X accumulator
27 * %r13 = literal pool pointer
28 * 0(%r15) - 63(%r15) scratch memory array with BPF_MEMWORDS
30 int bpf_jit_enable __read_mostly
;
33 * assembly code in arch/x86/net/bpf_jit.S
35 extern u8 sk_load_word
[], sk_load_half
[], sk_load_byte
[], sk_load_byte_msh
[];
36 extern u8 sk_load_word_ind
[], sk_load_half_ind
[], sk_load_byte_ind
[];
48 unsigned int off_load_word
;
49 unsigned int off_load_half
;
50 unsigned int off_load_byte
;
51 unsigned int off_load_bmsh
;
52 unsigned int off_load_iword
;
53 unsigned int off_load_ihalf
;
54 unsigned int off_load_ibyte
;
57 #define BPF_SIZE_MAX 4096 /* Max size for program */
59 #define SEEN_DATAREF 1 /* might call external helpers */
60 #define SEEN_XREG 2 /* ebx is used */
61 #define SEEN_MEM 4 /* use mem[] for temporary storage */
62 #define SEEN_RET0 8 /* pc_ret0 points to a valid return 0 */
63 #define SEEN_LITERAL 16 /* code uses literals */
64 #define SEEN_LOAD_WORD 32 /* code uses sk_load_word */
65 #define SEEN_LOAD_HALF 64 /* code uses sk_load_half */
66 #define SEEN_LOAD_BYTE 128 /* code uses sk_load_byte */
67 #define SEEN_LOAD_BMSH 256 /* code uses sk_load_byte_msh */
68 #define SEEN_LOAD_IWORD 512 /* code uses sk_load_word_ind */
69 #define SEEN_LOAD_IHALF 1024 /* code uses sk_load_half_ind */
70 #define SEEN_LOAD_IBYTE 2048 /* code uses sk_load_byte_ind */
74 if (jit->prg + 2 <= jit->mid) \
75 *(u16 *) jit->prg = op; \
81 if (jit->prg + 4 <= jit->mid) \
82 *(u32 *) jit->prg = op; \
86 #define EMIT4_DISP(op, disp) \
88 unsigned int __disp = (disp) & 0xfff; \
92 #define EMIT4_IMM(op, imm) \
94 unsigned int __imm = (imm) & 0xffff; \
98 #define EMIT4_PCREL(op, pcrel) \
100 long __pcrel = ((pcrel) >> 1) & 0xffff; \
101 EMIT4(op | __pcrel); \
104 #define EMIT6(op1, op2) \
106 if (jit->prg + 6 <= jit->mid) { \
107 *(u32 *) jit->prg = op1; \
108 *(u16 *) (jit->prg + 4) = op2; \
113 #define EMIT6_DISP(op1, op2, disp) \
115 unsigned int __disp = (disp) & 0xfff; \
116 EMIT6(op1 | __disp, op2); \
119 #define EMIT6_IMM(op, imm) \
121 unsigned int __imm = (imm); \
122 EMIT6(op | (__imm >> 16), __imm & 0xffff); \
125 #define EMIT_CONST(val) \
128 ret = (unsigned int) (jit->lit - jit->base_ip); \
129 jit->seen |= SEEN_LITERAL; \
130 if (jit->lit + 4 <= jit->end) \
131 *(u32 *) jit->lit = val; \
136 #define EMIT_FN_CONST(bit, fn) \
139 ret = (unsigned int) (jit->lit - jit->base_ip); \
140 if (jit->seen & bit) { \
141 jit->seen |= SEEN_LITERAL; \
142 if (jit->lit + 8 <= jit->end) \
143 *(void **) jit->lit = fn; \
149 static void bpf_jit_fill_hole(void *area
, unsigned int size
)
151 /* Fill whole space with illegal instructions */
152 memset(area
, 0, size
);
155 static void bpf_jit_prologue(struct bpf_jit
*jit
)
157 /* Save registers and create stack frame if necessary */
158 if (jit
->seen
& SEEN_DATAREF
) {
159 /* stmg %r8,%r15,88(%r15) */
160 EMIT6(0xeb8ff058, 0x0024);
163 /* aghi %r15,<offset> */
164 EMIT4_IMM(0xa7fb0000, (jit
->seen
& SEEN_MEM
) ? -112 : -80);
165 /* stg %r14,152(%r15) */
166 EMIT6(0xe3e0f098, 0x0024);
167 } else if ((jit
->seen
& SEEN_XREG
) && (jit
->seen
& SEEN_LITERAL
))
168 /* stmg %r12,%r13,120(%r15) */
169 EMIT6(0xebcdf078, 0x0024);
170 else if (jit
->seen
& SEEN_XREG
)
171 /* stg %r12,120(%r15) */
172 EMIT6(0xe3c0f078, 0x0024);
173 else if (jit
->seen
& SEEN_LITERAL
)
174 /* stg %r13,128(%r15) */
175 EMIT6(0xe3d0f080, 0x0024);
177 /* Setup literal pool */
178 if (jit
->seen
& SEEN_LITERAL
) {
181 jit
->base_ip
= jit
->prg
;
183 jit
->off_load_word
= EMIT_FN_CONST(SEEN_LOAD_WORD
, sk_load_word
);
184 jit
->off_load_half
= EMIT_FN_CONST(SEEN_LOAD_HALF
, sk_load_half
);
185 jit
->off_load_byte
= EMIT_FN_CONST(SEEN_LOAD_BYTE
, sk_load_byte
);
186 jit
->off_load_bmsh
= EMIT_FN_CONST(SEEN_LOAD_BMSH
, sk_load_byte_msh
);
187 jit
->off_load_iword
= EMIT_FN_CONST(SEEN_LOAD_IWORD
, sk_load_word_ind
);
188 jit
->off_load_ihalf
= EMIT_FN_CONST(SEEN_LOAD_IHALF
, sk_load_half_ind
);
189 jit
->off_load_ibyte
= EMIT_FN_CONST(SEEN_LOAD_IBYTE
, sk_load_byte_ind
);
191 /* Filter needs to access skb data */
192 if (jit
->seen
& SEEN_DATAREF
) {
193 /* l %r11,<len>(%r2) */
194 EMIT4_DISP(0x58b02000, offsetof(struct sk_buff
, len
));
195 /* s %r11,<data_len>(%r2) */
196 EMIT4_DISP(0x5bb02000, offsetof(struct sk_buff
, data_len
));
197 /* lg %r10,<data>(%r2) */
198 EMIT6_DISP(0xe3a02000, 0x0004,
199 offsetof(struct sk_buff
, data
));
203 static void bpf_jit_epilogue(struct bpf_jit
*jit
)
206 if (jit
->seen
& SEEN_RET0
) {
207 jit
->ret0_ip
= jit
->prg
;
211 jit
->exit_ip
= jit
->prg
;
212 /* Restore registers */
213 if (jit
->seen
& SEEN_DATAREF
)
214 /* lmg %r8,%r15,<offset>(%r15) */
215 EMIT6_DISP(0xeb8ff000, 0x0004,
216 (jit
->seen
& SEEN_MEM
) ? 200 : 168);
217 else if ((jit
->seen
& SEEN_XREG
) && (jit
->seen
& SEEN_LITERAL
))
218 /* lmg %r12,%r13,120(%r15) */
219 EMIT6(0xebcdf078, 0x0004);
220 else if (jit
->seen
& SEEN_XREG
)
221 /* lg %r12,120(%r15) */
222 EMIT6(0xe3c0f078, 0x0004);
223 else if (jit
->seen
& SEEN_LITERAL
)
224 /* lg %r13,128(%r15) */
225 EMIT6(0xe3d0f080, 0x0004);
231 * make sure we dont leak kernel information to user
233 static void bpf_jit_noleaks(struct bpf_jit
*jit
, struct sock_filter
*filter
)
235 /* Clear temporary memory if (seen & SEEN_MEM) */
236 if (jit
->seen
& SEEN_MEM
)
237 /* xc 0(64,%r15),0(%r15) */
238 EMIT6(0xd73ff000, 0xf000);
239 /* Clear X if (seen & SEEN_XREG) */
240 if (jit
->seen
& SEEN_XREG
)
243 /* Clear A if the first register does not set it. */
244 switch (filter
[0].code
) {
245 case BPF_LD
| BPF_W
| BPF_ABS
:
246 case BPF_LD
| BPF_H
| BPF_ABS
:
247 case BPF_LD
| BPF_B
| BPF_ABS
:
248 case BPF_LD
| BPF_W
| BPF_LEN
:
249 case BPF_LD
| BPF_W
| BPF_IND
:
250 case BPF_LD
| BPF_H
| BPF_IND
:
251 case BPF_LD
| BPF_B
| BPF_IND
:
252 case BPF_LD
| BPF_IMM
:
253 case BPF_LD
| BPF_MEM
:
254 case BPF_MISC
| BPF_TXA
:
255 case BPF_RET
| BPF_K
:
256 /* first instruction sets A register */
264 static int bpf_jit_insn(struct bpf_jit
*jit
, struct sock_filter
*filter
,
265 unsigned int *addrs
, int i
, int last
)
273 code
= bpf_anc_helper(filter
);
276 case BPF_ALU
| BPF_ADD
| BPF_X
: /* A += X */
277 jit
->seen
|= SEEN_XREG
;
281 case BPF_ALU
| BPF_ADD
| BPF_K
: /* A += K */
286 EMIT4_IMM(0xa75a0000, K
);
287 else if (test_facility(21))
289 EMIT6_IMM(0xc25b0000, K
);
291 /* a %r5,<d(K)>(%r13) */
292 EMIT4_DISP(0x5a50d000, EMIT_CONST(K
));
294 case BPF_ALU
| BPF_SUB
| BPF_X
: /* A -= X */
295 jit
->seen
|= SEEN_XREG
;
299 case BPF_ALU
| BPF_SUB
| BPF_K
: /* A -= K */
304 EMIT4_IMM(0xa75a0000, -K
);
305 else if (test_facility(21))
307 EMIT6_IMM(0xc25b0000, -K
);
309 /* s %r5,<d(K)>(%r13) */
310 EMIT4_DISP(0x5b50d000, EMIT_CONST(K
));
312 case BPF_ALU
| BPF_MUL
| BPF_X
: /* A *= X */
313 jit
->seen
|= SEEN_XREG
;
317 case BPF_ALU
| BPF_MUL
| BPF_K
: /* A *= K */
320 EMIT4_IMM(0xa75c0000, K
);
321 else if (test_facility(34))
323 EMIT6_IMM(0xc2510000, K
);
325 /* ms %r5,<d(K)>(%r13) */
326 EMIT4_DISP(0x7150d000, EMIT_CONST(K
));
328 case BPF_ALU
| BPF_DIV
| BPF_X
: /* A /= X */
329 jit
->seen
|= SEEN_XREG
| SEEN_RET0
;
333 EMIT4_PCREL(0xa7840000, (jit
->ret0_ip
- jit
->prg
));
339 case BPF_ALU
| BPF_DIV
| BPF_K
: /* A /= K */
344 /* dl %r4,<d(K)>(%r13) */
345 EMIT6_DISP(0xe340d000, 0x0097, EMIT_CONST(K
));
347 case BPF_ALU
| BPF_MOD
| BPF_X
: /* A %= X */
348 jit
->seen
|= SEEN_XREG
| SEEN_RET0
;
352 EMIT4_PCREL(0xa7840000, (jit
->ret0_ip
- jit
->prg
));
360 case BPF_ALU
| BPF_MOD
| BPF_K
: /* A %= K */
368 /* dl %r4,<d(K)>(%r13) */
369 EMIT6_DISP(0xe340d000, 0x0097, EMIT_CONST(K
));
373 case BPF_ALU
| BPF_AND
| BPF_X
: /* A &= X */
374 jit
->seen
|= SEEN_XREG
;
378 case BPF_ALU
| BPF_AND
| BPF_K
: /* A &= K */
379 if (test_facility(21))
381 EMIT6_IMM(0xc05b0000, K
);
383 /* n %r5,<d(K)>(%r13) */
384 EMIT4_DISP(0x5450d000, EMIT_CONST(K
));
386 case BPF_ALU
| BPF_OR
| BPF_X
: /* A |= X */
387 jit
->seen
|= SEEN_XREG
;
391 case BPF_ALU
| BPF_OR
| BPF_K
: /* A |= K */
392 if (test_facility(21))
394 EMIT6_IMM(0xc05d0000, K
);
396 /* o %r5,<d(K)>(%r13) */
397 EMIT4_DISP(0x5650d000, EMIT_CONST(K
));
399 case BPF_ANC
| SKF_AD_ALU_XOR_X
: /* A ^= X; */
400 case BPF_ALU
| BPF_XOR
| BPF_X
:
401 jit
->seen
|= SEEN_XREG
;
405 case BPF_ALU
| BPF_XOR
| BPF_K
: /* A ^= K */
408 /* x %r5,<d(K)>(%r13) */
409 EMIT4_DISP(0x5750d000, EMIT_CONST(K
));
411 case BPF_ALU
| BPF_LSH
| BPF_X
: /* A <<= X; */
412 jit
->seen
|= SEEN_XREG
;
413 /* sll %r5,0(%r12) */
416 case BPF_ALU
| BPF_LSH
| BPF_K
: /* A <<= K */
420 EMIT4_DISP(0x89500000, K
);
422 case BPF_ALU
| BPF_RSH
| BPF_X
: /* A >>= X; */
423 jit
->seen
|= SEEN_XREG
;
424 /* srl %r5,0(%r12) */
427 case BPF_ALU
| BPF_RSH
| BPF_K
: /* A >>= K; */
431 EMIT4_DISP(0x88500000, K
);
433 case BPF_ALU
| BPF_NEG
: /* A = -A */
437 case BPF_JMP
| BPF_JA
: /* ip += K */
438 offset
= addrs
[i
+ K
] + jit
->start
- jit
->prg
;
439 EMIT4_PCREL(0xa7f40000, offset
);
441 case BPF_JMP
| BPF_JGT
| BPF_K
: /* ip += (A > K) ? jt : jf */
442 mask
= 0x200000; /* jh */
444 case BPF_JMP
| BPF_JGE
| BPF_K
: /* ip += (A >= K) ? jt : jf */
445 mask
= 0xa00000; /* jhe */
447 case BPF_JMP
| BPF_JEQ
| BPF_K
: /* ip += (A == K) ? jt : jf */
448 mask
= 0x800000; /* je */
449 kbranch
: /* Emit compare if the branch targets are different */
450 if (filter
->jt
!= filter
->jf
) {
453 EMIT4_IMM(0xa75e0000, K
);
454 else if (test_facility(21))
456 EMIT6_IMM(0xc25f0000, K
);
458 /* c %r5,<d(K)>(%r13) */
459 EMIT4_DISP(0x5950d000, EMIT_CONST(K
));
461 branch
: if (filter
->jt
== filter
->jf
) {
465 offset
= addrs
[i
+ filter
->jt
] + jit
->start
- jit
->prg
;
466 EMIT4_PCREL(0xa7f40000, offset
);
469 if (filter
->jt
!= 0) {
470 /* brc <mask>,<jt> */
471 offset
= addrs
[i
+ filter
->jt
] + jit
->start
- jit
->prg
;
472 EMIT4_PCREL(0xa7040000 | mask
, offset
);
474 if (filter
->jf
!= 0) {
475 /* brc <mask^15>,<jf> */
476 offset
= addrs
[i
+ filter
->jf
] + jit
->start
- jit
->prg
;
477 EMIT4_PCREL(0xa7040000 | (mask
^ 0xf00000), offset
);
480 case BPF_JMP
| BPF_JSET
| BPF_K
: /* ip += (A & K) ? jt : jf */
481 mask
= 0x700000; /* jnz */
482 /* Emit test if the branch targets are different */
483 if (filter
->jt
!= filter
->jf
) {
487 /* n %r4,<d(K)>(%r13) */
488 EMIT4_DISP(0x5440d000, EMIT_CONST(K
));
491 EMIT4_IMM(0xa7510000, K
);
494 case BPF_JMP
| BPF_JGT
| BPF_X
: /* ip += (A > X) ? jt : jf */
495 mask
= 0x200000; /* jh */
497 case BPF_JMP
| BPF_JGE
| BPF_X
: /* ip += (A >= X) ? jt : jf */
498 mask
= 0xa00000; /* jhe */
500 case BPF_JMP
| BPF_JEQ
| BPF_X
: /* ip += (A == X) ? jt : jf */
501 mask
= 0x800000; /* je */
502 xbranch
: /* Emit compare if the branch targets are different */
503 if (filter
->jt
!= filter
->jf
) {
504 jit
->seen
|= SEEN_XREG
;
509 case BPF_JMP
| BPF_JSET
| BPF_X
: /* ip += (A & X) ? jt : jf */
510 mask
= 0x700000; /* jnz */
511 /* Emit test if the branch targets are different */
512 if (filter
->jt
!= filter
->jf
) {
513 jit
->seen
|= SEEN_XREG
;
520 case BPF_LD
| BPF_W
| BPF_ABS
: /* A = *(u32 *) (skb->data+K) */
521 jit
->seen
|= SEEN_DATAREF
| SEEN_RET0
| SEEN_LOAD_WORD
;
522 offset
= jit
->off_load_word
;
524 case BPF_LD
| BPF_H
| BPF_ABS
: /* A = *(u16 *) (skb->data+K) */
525 jit
->seen
|= SEEN_DATAREF
| SEEN_RET0
| SEEN_LOAD_HALF
;
526 offset
= jit
->off_load_half
;
528 case BPF_LD
| BPF_B
| BPF_ABS
: /* A = *(u8 *) (skb->data+K) */
529 jit
->seen
|= SEEN_DATAREF
| SEEN_RET0
| SEEN_LOAD_BYTE
;
530 offset
= jit
->off_load_byte
;
531 load_abs
: if ((int) K
< 0)
533 call_fn
: /* lg %r1,<d(function)>(%r13) */
534 EMIT6_DISP(0xe310d000, 0x0004, offset
);
535 /* l %r3,<d(K)>(%r13) */
536 EMIT4_DISP(0x5830d000, EMIT_CONST(K
));
540 EMIT4_PCREL(0xa7740000, (jit
->ret0_ip
- jit
->prg
));
542 case BPF_LD
| BPF_W
| BPF_IND
: /* A = *(u32 *) (skb->data+K+X) */
543 jit
->seen
|= SEEN_DATAREF
| SEEN_RET0
| SEEN_LOAD_IWORD
;
544 offset
= jit
->off_load_iword
;
546 case BPF_LD
| BPF_H
| BPF_IND
: /* A = *(u16 *) (skb->data+K+X) */
547 jit
->seen
|= SEEN_DATAREF
| SEEN_RET0
| SEEN_LOAD_IHALF
;
548 offset
= jit
->off_load_ihalf
;
550 case BPF_LD
| BPF_B
| BPF_IND
: /* A = *(u8 *) (skb->data+K+X) */
551 jit
->seen
|= SEEN_DATAREF
| SEEN_RET0
| SEEN_LOAD_IBYTE
;
552 offset
= jit
->off_load_ibyte
;
554 case BPF_LDX
| BPF_B
| BPF_MSH
:
555 /* X = (*(u8 *)(skb->data+K) & 0xf) << 2 */
556 jit
->seen
|= SEEN_RET0
;
559 EMIT4_PCREL(0xa7f40000, (jit
->ret0_ip
- jit
->prg
));
562 jit
->seen
|= SEEN_DATAREF
| SEEN_LOAD_BMSH
;
563 offset
= jit
->off_load_bmsh
;
565 case BPF_LD
| BPF_W
| BPF_LEN
: /* A = skb->len; */
566 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, len
) != 4);
567 /* l %r5,<d(len)>(%r2) */
568 EMIT4_DISP(0x58502000, offsetof(struct sk_buff
, len
));
570 case BPF_LDX
| BPF_W
| BPF_LEN
: /* X = skb->len; */
571 jit
->seen
|= SEEN_XREG
;
572 /* l %r12,<d(len)>(%r2) */
573 EMIT4_DISP(0x58c02000, offsetof(struct sk_buff
, len
));
575 case BPF_LD
| BPF_IMM
: /* A = K */
578 EMIT4_IMM(0xa7580000, K
);
579 else if (test_facility(21))
581 EMIT6_IMM(0xc05f0000, K
);
583 /* l %r5,<d(K)>(%r13) */
584 EMIT4_DISP(0x5850d000, EMIT_CONST(K
));
586 case BPF_LDX
| BPF_IMM
: /* X = K */
587 jit
->seen
|= SEEN_XREG
;
590 EMIT4_IMM(0xa7c80000, K
);
591 else if (test_facility(21))
593 EMIT6_IMM(0xc0cf0000, K
);
595 /* l %r12,<d(K)>(%r13) */
596 EMIT4_DISP(0x58c0d000, EMIT_CONST(K
));
598 case BPF_LD
| BPF_MEM
: /* A = mem[K] */
599 jit
->seen
|= SEEN_MEM
;
600 /* l %r5,<K>(%r15) */
601 EMIT4_DISP(0x5850f000,
602 (jit
->seen
& SEEN_DATAREF
) ? 160 + K
*4 : K
*4);
604 case BPF_LDX
| BPF_MEM
: /* X = mem[K] */
605 jit
->seen
|= SEEN_XREG
| SEEN_MEM
;
606 /* l %r12,<K>(%r15) */
607 EMIT4_DISP(0x58c0f000,
608 (jit
->seen
& SEEN_DATAREF
) ? 160 + K
*4 : K
*4);
610 case BPF_MISC
| BPF_TAX
: /* X = A */
611 jit
->seen
|= SEEN_XREG
;
615 case BPF_MISC
| BPF_TXA
: /* A = X */
616 jit
->seen
|= SEEN_XREG
;
620 case BPF_RET
| BPF_K
:
622 jit
->seen
|= SEEN_RET0
;
626 EMIT4_PCREL(0xa7f40000, jit
->ret0_ip
- jit
->prg
);
630 EMIT4_IMM(0xa7290000, K
);
632 /* llgf %r2,<K>(%r13) */
633 EMIT6_DISP(0xe320d000, 0x0016, EMIT_CONST(K
));
635 if (last
&& !(jit
->seen
& SEEN_RET0
))
637 EMIT4_PCREL(0xa7f40000, jit
->exit_ip
- jit
->prg
);
640 case BPF_RET
| BPF_A
:
644 EMIT4_PCREL(0xa7f40000, jit
->exit_ip
- jit
->prg
);
646 case BPF_ST
: /* mem[K] = A */
647 jit
->seen
|= SEEN_MEM
;
648 /* st %r5,<K>(%r15) */
649 EMIT4_DISP(0x5050f000,
650 (jit
->seen
& SEEN_DATAREF
) ? 160 + K
*4 : K
*4);
652 case BPF_STX
: /* mem[K] = X : mov %ebx,off8(%rbp) */
653 jit
->seen
|= SEEN_XREG
| SEEN_MEM
;
654 /* st %r12,<K>(%r15) */
655 EMIT4_DISP(0x50c0f000,
656 (jit
->seen
& SEEN_DATAREF
) ? 160 + K
*4 : K
*4);
658 case BPF_ANC
| SKF_AD_PROTOCOL
: /* A = ntohs(skb->protocol); */
659 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, protocol
) != 2);
662 /* icm %r5,3,<d(protocol)>(%r2) */
663 EMIT4_DISP(0xbf532000, offsetof(struct sk_buff
, protocol
));
665 case BPF_ANC
| SKF_AD_IFINDEX
: /* if (!skb->dev) return 0;
666 * A = skb->dev->ifindex */
667 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device
, ifindex
) != 4);
668 jit
->seen
|= SEEN_RET0
;
669 /* lg %r1,<d(dev)>(%r2) */
670 EMIT6_DISP(0xe3102000, 0x0004, offsetof(struct sk_buff
, dev
));
674 EMIT4_PCREL(0xa7840000, jit
->ret0_ip
- jit
->prg
);
675 /* l %r5,<d(ifindex)>(%r1) */
676 EMIT4_DISP(0x58501000, offsetof(struct net_device
, ifindex
));
678 case BPF_ANC
| SKF_AD_MARK
: /* A = skb->mark */
679 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, mark
) != 4);
680 /* l %r5,<d(mark)>(%r2) */
681 EMIT4_DISP(0x58502000, offsetof(struct sk_buff
, mark
));
683 case BPF_ANC
| SKF_AD_QUEUE
: /* A = skb->queue_mapping */
684 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, queue_mapping
) != 2);
687 /* icm %r5,3,<d(queue_mapping)>(%r2) */
688 EMIT4_DISP(0xbf532000, offsetof(struct sk_buff
, queue_mapping
));
690 case BPF_ANC
| SKF_AD_HATYPE
: /* if (!skb->dev) return 0;
691 * A = skb->dev->type */
692 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device
, type
) != 2);
693 jit
->seen
|= SEEN_RET0
;
694 /* lg %r1,<d(dev)>(%r2) */
695 EMIT6_DISP(0xe3102000, 0x0004, offsetof(struct sk_buff
, dev
));
699 EMIT4_PCREL(0xa7840000, jit
->ret0_ip
- jit
->prg
);
702 /* icm %r5,3,<d(type)>(%r1) */
703 EMIT4_DISP(0xbf531000, offsetof(struct net_device
, type
));
705 case BPF_ANC
| SKF_AD_RXHASH
: /* A = skb->hash */
706 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, hash
) != 4);
707 /* l %r5,<d(hash)>(%r2) */
708 EMIT4_DISP(0x58502000, offsetof(struct sk_buff
, hash
));
710 case BPF_ANC
| SKF_AD_VLAN_TAG
:
711 case BPF_ANC
| SKF_AD_VLAN_TAG_PRESENT
:
712 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, vlan_tci
) != 2);
713 BUILD_BUG_ON(VLAN_TAG_PRESENT
!= 0x1000);
716 /* icm %r5,3,<d(vlan_tci)>(%r2) */
717 EMIT4_DISP(0xbf532000, offsetof(struct sk_buff
, vlan_tci
));
718 if (code
== (BPF_ANC
| SKF_AD_VLAN_TAG
)) {
719 /* nill %r5,0xefff */
720 EMIT4_IMM(0xa5570000, ~VLAN_TAG_PRESENT
);
722 /* nill %r5,0x1000 */
723 EMIT4_IMM(0xa5570000, VLAN_TAG_PRESENT
);
725 EMIT4_DISP(0x88500000, 12);
728 case BPF_ANC
| SKF_AD_PKTTYPE
:
731 /* ic %r5,<d(pkt_type_offset)>(%r2) */
732 EMIT4_DISP(0x43502000, PKT_TYPE_OFFSET());
734 EMIT4_DISP(0x88500000, 5);
736 case BPF_ANC
| SKF_AD_CPU
: /* A = smp_processor_id() */
738 /* l %r5,<d(cpu_nr)> */
739 EMIT4_DISP(0x58500000, offsetof(struct _lowcore
, cpu_nr
));
745 default: /* too complex, give up */
748 addrs
[i
] = jit
->prg
- jit
->start
;
754 void bpf_jit_compile(struct bpf_prog
*fp
)
756 struct bpf_binary_header
*header
= NULL
;
757 unsigned long size
, prg_len
, lit_len
;
758 struct bpf_jit jit
, cjit
;
764 addrs
= kcalloc(fp
->len
, sizeof(*addrs
), GFP_KERNEL
);
767 memset(&jit
, 0, sizeof(cjit
));
768 memset(&cjit
, 0, sizeof(cjit
));
770 for (pass
= 0; pass
< 10; pass
++) {
774 bpf_jit_prologue(&jit
);
775 bpf_jit_noleaks(&jit
, fp
->insns
);
776 for (i
= 0; i
< fp
->len
; i
++) {
777 if (bpf_jit_insn(&jit
, fp
->insns
+ i
, addrs
, i
,
781 bpf_jit_epilogue(&jit
);
783 WARN_ON(jit
.prg
> cjit
.prg
|| jit
.lit
> cjit
.lit
);
784 if (memcmp(&jit
, &cjit
, sizeof(jit
)) == 0)
786 } else if (jit
.prg
== cjit
.prg
&& jit
.lit
== cjit
.lit
) {
787 prg_len
= jit
.prg
- jit
.start
;
788 lit_len
= jit
.lit
- jit
.mid
;
789 size
= prg_len
+ lit_len
;
790 if (size
>= BPF_SIZE_MAX
)
792 header
= bpf_jit_binary_alloc(size
, &jit
.start
,
793 2, bpf_jit_fill_hole
);
796 jit
.prg
= jit
.mid
= jit
.start
+ prg_len
;
797 jit
.lit
= jit
.end
= jit
.start
+ prg_len
+ lit_len
;
798 jit
.base_ip
+= (unsigned long) jit
.start
;
799 jit
.exit_ip
+= (unsigned long) jit
.start
;
800 jit
.ret0_ip
+= (unsigned long) jit
.start
;
804 if (bpf_jit_enable
> 1) {
805 bpf_jit_dump(fp
->len
, jit
.end
- jit
.start
, pass
, jit
.start
);
807 print_fn_code(jit
.start
, jit
.mid
- jit
.start
);
810 set_memory_ro((unsigned long)header
, header
->pages
);
811 fp
->bpf_func
= (void *) jit
.start
;
818 void bpf_jit_free(struct bpf_prog
*fp
)
820 unsigned long addr
= (unsigned long)fp
->bpf_func
& PAGE_MASK
;
821 struct bpf_binary_header
*header
= (void *)addr
;
826 set_memory_rw(addr
, header
->pages
);
827 bpf_jit_binary_free(header
);
830 bpf_prog_unlock_free(fp
);