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drivers/net,AT91RM9200: add missing GENERIC_HARDIRQS dependency
[mirror_ubuntu-artful-kernel.git] / arch / s390 / net / bpf_jit_comp.c
CommitLineData
c10302ef
MS		 1/*
2 * BPF Jit compiler for s390.
3 *
4 * Copyright IBM Corp. 2012
5 *
6 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7 */
8#include <linux/moduleloader.h>
9#include <linux/netdevice.h>
10#include <linux/filter.h>
11#include <asm/cacheflush.h>
12#include <asm/processor.h>
68d9884d 13#include <asm/facility.h>
c10302ef
MS		 14
15/*
16 * Conventions:
17 * %r2 = skb pointer
18 * %r3 = offset parameter
19 * %r4 = scratch register / length parameter
20 * %r5 = BPF A accumulator
21 * %r8 = return address
22 * %r9 = save register for skb pointer
23 * %r10 = skb->data
24 * %r11 = skb->len - skb->data_len (headlen)
25 * %r12 = BPF X accumulator
26 * %r13 = literal pool pointer
27 * 0(%r15) - 63(%r15) scratch memory array with BPF_MEMWORDS
28 */
29int bpf_jit_enable __read_mostly;
30
31/*
32 * assembly code in arch/x86/net/bpf_jit.S
33 */
34extern u8 sk_load_word[], sk_load_half[], sk_load_byte[], sk_load_byte_msh[];
35extern u8 sk_load_word_ind[], sk_load_half_ind[], sk_load_byte_ind[];
36
37struct bpf_jit {
38 unsigned int seen;
39 u8 *start;
40 u8 *prg;
41 u8 *mid;
42 u8 *lit;
43 u8 *end;
44 u8 *base_ip;
45 u8 *ret0_ip;
46 u8 *exit_ip;
47 unsigned int off_load_word;
48 unsigned int off_load_half;
49 unsigned int off_load_byte;
50 unsigned int off_load_bmsh;
51 unsigned int off_load_iword;
52 unsigned int off_load_ihalf;
53 unsigned int off_load_ibyte;
54};
55
56#define BPF_SIZE_MAX 4096 /* Max size for program */
57
58#define SEEN_DATAREF 1 /* might call external helpers */
59#define SEEN_XREG 2 /* ebx is used */
60#define SEEN_MEM 4 /* use mem[] for temporary storage */
61#define SEEN_RET0 8 /* pc_ret0 points to a valid return 0 */
62#define SEEN_LITERAL 16 /* code uses literals */
63#define SEEN_LOAD_WORD 32 /* code uses sk_load_word */
64#define SEEN_LOAD_HALF 64 /* code uses sk_load_half */
65#define SEEN_LOAD_BYTE 128 /* code uses sk_load_byte */
66#define SEEN_LOAD_BMSH 256 /* code uses sk_load_byte_msh */
67#define SEEN_LOAD_IWORD 512 /* code uses sk_load_word_ind */
68#define SEEN_LOAD_IHALF 1024 /* code uses sk_load_half_ind */
69#define SEEN_LOAD_IBYTE 2048 /* code uses sk_load_byte_ind */
70
71#define EMIT2(op) \
72({ \
73 if (jit->prg + 2 <= jit->mid) \
74 *(u16 *) jit->prg = op; \
75 jit->prg += 2; \
76})
77
78#define EMIT4(op) \
79({ \
80 if (jit->prg + 4 <= jit->mid) \
81 *(u32 *) jit->prg = op; \
82 jit->prg += 4; \
83})
84
85#define EMIT4_DISP(op, disp) \
86({ \
87 unsigned int __disp = (disp) & 0xfff; \
88 EMIT4(op | __disp); \
89})
90
91#define EMIT4_IMM(op, imm) \
92({ \
93 unsigned int __imm = (imm) & 0xffff; \
94 EMIT4(op | __imm); \
95})
96
97#define EMIT4_PCREL(op, pcrel) \
98({ \
99 long __pcrel = ((pcrel) >> 1) & 0xffff; \
100 EMIT4(op | __pcrel); \
101})
102
103#define EMIT6(op1, op2) \
104({ \
105 if (jit->prg + 6 <= jit->mid) { \
106 *(u32 *) jit->prg = op1; \
107 *(u16 *) (jit->prg + 4) = op2; \
108 } \
109 jit->prg += 6; \
110})
111
112#define EMIT6_DISP(op1, op2, disp) \
113({ \
114 unsigned int __disp = (disp) & 0xfff; \
115 EMIT6(op1 | __disp, op2); \
116})
117
68d9884d
HC		 118#define EMIT6_IMM(op, imm) \
119({ \
120 unsigned int __imm = (imm); \
121 EMIT6(op | (__imm >> 16), __imm & 0xffff); \
122})
123
c10302ef
MS		 124#define EMIT_CONST(val) \
125({ \
126 unsigned int ret; \
127 ret = (unsigned int) (jit->lit - jit->base_ip); \
128 jit->seen |= SEEN_LITERAL; \
129 if (jit->lit + 4 <= jit->end) \
130 *(u32 *) jit->lit = val; \
131 jit->lit += 4; \
132 ret; \
133})
134
135#define EMIT_FN_CONST(bit, fn) \
136({ \
137 unsigned int ret; \
138 ret = (unsigned int) (jit->lit - jit->base_ip); \
139 if (jit->seen & bit) { \
140 jit->seen |= SEEN_LITERAL; \
141 if (jit->lit + 8 <= jit->end) \
142 *(void **) jit->lit = fn; \
143 jit->lit += 8; \
144 } \
145 ret; \
146})
147
148static void bpf_jit_prologue(struct bpf_jit *jit)
149{
150 /* Save registers and create stack frame if necessary */
151 if (jit->seen & SEEN_DATAREF) {
152 /* stmg %r8,%r15,88(%r15) */
153 EMIT6(0xeb8ff058, 0x0024);
154 /* lgr %r14,%r15 */
155 EMIT4(0xb90400ef);
156 /* ahi %r15,<offset> */
157 EMIT4_IMM(0xa7fa0000, (jit->seen & SEEN_MEM) ? -112 : -80);
158 /* stg %r14,152(%r15) */
159 EMIT6(0xe3e0f098, 0x0024);
160 } else if ((jit->seen & SEEN_XREG) && (jit->seen & SEEN_LITERAL))
161 /* stmg %r12,%r13,120(%r15) */
162 EMIT6(0xebcdf078, 0x0024);
163 else if (jit->seen & SEEN_XREG)
164 /* stg %r12,120(%r15) */
165 EMIT6(0xe3c0f078, 0x0024);
166 else if (jit->seen & SEEN_LITERAL)
167 /* stg %r13,128(%r15) */
168 EMIT6(0xe3d0f080, 0x0024);
169
170 /* Setup literal pool */
171 if (jit->seen & SEEN_LITERAL) {
172 /* basr %r13,0 */
173 EMIT2(0x0dd0);
174 jit->base_ip = jit->prg;
175 }
176 jit->off_load_word = EMIT_FN_CONST(SEEN_LOAD_WORD, sk_load_word);
177 jit->off_load_half = EMIT_FN_CONST(SEEN_LOAD_HALF, sk_load_half);
178 jit->off_load_byte = EMIT_FN_CONST(SEEN_LOAD_BYTE, sk_load_byte);
179 jit->off_load_bmsh = EMIT_FN_CONST(SEEN_LOAD_BMSH, sk_load_byte_msh);
180 jit->off_load_iword = EMIT_FN_CONST(SEEN_LOAD_IWORD, sk_load_word_ind);
181 jit->off_load_ihalf = EMIT_FN_CONST(SEEN_LOAD_IHALF, sk_load_half_ind);
182 jit->off_load_ibyte = EMIT_FN_CONST(SEEN_LOAD_IBYTE, sk_load_byte_ind);
183
184 /* Filter needs to access skb data */
185 if (jit->seen & SEEN_DATAREF) {
186 /* l %r11,<len>(%r2) */
187 EMIT4_DISP(0x58b02000, offsetof(struct sk_buff, len));
188 /* s %r11,<data_len>(%r2) */
189 EMIT4_DISP(0x5bb02000, offsetof(struct sk_buff, data_len));
190 /* lg %r10,<data>(%r2) */
191 EMIT6_DISP(0xe3a02000, 0x0004,
192 offsetof(struct sk_buff, data));
193 }
194}
195
196static void bpf_jit_epilogue(struct bpf_jit *jit)
197{
198 /* Return 0 */
199 if (jit->seen & SEEN_RET0) {
200 jit->ret0_ip = jit->prg;
201 /* lghi %r2,0 */
202 EMIT4(0xa7290000);
203 }
204 jit->exit_ip = jit->prg;
205 /* Restore registers */
206 if (jit->seen & SEEN_DATAREF)
207 /* lmg %r8,%r15,<offset>(%r15) */
208 EMIT6_DISP(0xeb8ff000, 0x0004,
209 (jit->seen & SEEN_MEM) ? 200 : 168);
210 else if ((jit->seen & SEEN_XREG) && (jit->seen & SEEN_LITERAL))
211 /* lmg %r12,%r13,120(%r15) */
212 EMIT6(0xebcdf078, 0x0004);
213 else if (jit->seen & SEEN_XREG)
214 /* lg %r12,120(%r15) */
215 EMIT6(0xe3c0f078, 0x0004);
216 else if (jit->seen & SEEN_LITERAL)
217 /* lg %r13,128(%r15) */
218 EMIT6(0xe3d0f080, 0x0004);
219 /* br %r14 */
220 EMIT2(0x07fe);
221}
222
223/*
224 * make sure we dont leak kernel information to user
225 */
226static void bpf_jit_noleaks(struct bpf_jit *jit, struct sock_filter *filter)
227{
228 /* Clear temporary memory if (seen & SEEN_MEM) */
229 if (jit->seen & SEEN_MEM)
230 /* xc 0(64,%r15),0(%r15) */
231 EMIT6(0xd73ff000, 0xf000);
232 /* Clear X if (seen & SEEN_XREG) */
233 if (jit->seen & SEEN_XREG)
234 /* lhi %r12,0 */
235 EMIT4(0xa7c80000);
236 /* Clear A if the first register does not set it. */
237 switch (filter[0].code) {
238 case BPF_S_LD_W_ABS:
239 case BPF_S_LD_H_ABS:
240 case BPF_S_LD_B_ABS:
241 case BPF_S_LD_W_LEN:
242 case BPF_S_LD_W_IND:
243 case BPF_S_LD_H_IND:
244 case BPF_S_LD_B_IND:
245 case BPF_S_LDX_B_MSH:
246 case BPF_S_LD_IMM:
247 case BPF_S_LD_MEM:
248 case BPF_S_MISC_TXA:
249 case BPF_S_ANC_PROTOCOL:
250 case BPF_S_ANC_PKTTYPE:
251 case BPF_S_ANC_IFINDEX:
252 case BPF_S_ANC_MARK:
253 case BPF_S_ANC_QUEUE:
254 case BPF_S_ANC_HATYPE:
255 case BPF_S_ANC_RXHASH:
256 case BPF_S_ANC_CPU:
257 case BPF_S_RET_K:
258 /* first instruction sets A register */
259 break;
260 default: /* A = 0 */
261 /* lhi %r5,0 */
262 EMIT4(0xa7580000);
263 }
264}
265
266static int bpf_jit_insn(struct bpf_jit *jit, struct sock_filter *filter,
267 unsigned int *addrs, int i, int last)
268{
269 unsigned int K;
270 int offset;
271 unsigned int mask;
272
273 K = filter->k;
274 switch (filter->code) {
275 case BPF_S_ALU_ADD_X: /* A += X */
276 jit->seen |= SEEN_XREG;
277 /* ar %r5,%r12 */
278 EMIT2(0x1a5c);
279 break;
280 case BPF_S_ALU_ADD_K: /* A += K */
281 if (!K)
282 break;
283 if (K <= 16383)
284 /* ahi %r5,<K> */
285 EMIT4_IMM(0xa75a0000, K);
68d9884d
HC		 286 else if (test_facility(21))
287 /* alfi %r5,<K> */
288 EMIT6_IMM(0xc25b0000, K);
c10302ef
MS		 289 else
290 /* a %r5,<d(K)>(%r13) */
291 EMIT4_DISP(0x5a50d000, EMIT_CONST(K));
292 break;
293 case BPF_S_ALU_SUB_X: /* A -= X */
294 jit->seen |= SEEN_XREG;
295 /* sr %r5,%r12 */
296 EMIT2(0x1b5c);
297 break;
298 case BPF_S_ALU_SUB_K: /* A -= K */
299 if (!K)
300 break;
301 if (K <= 16384)
302 /* ahi %r5,-K */
303 EMIT4_IMM(0xa75a0000, -K);
68d9884d
HC		 304 else if (test_facility(21))
305 /* alfi %r5,-K */
306 EMIT6_IMM(0xc25b0000, -K);
c10302ef
MS		 307 else
308 /* s %r5,<d(K)>(%r13) */
309 EMIT4_DISP(0x5b50d000, EMIT_CONST(K));
310 break;
311 case BPF_S_ALU_MUL_X: /* A *= X */
312 jit->seen |= SEEN_XREG;
313 /* msr %r5,%r12 */
314 EMIT4(0xb252005c);
315 break;
316 case BPF_S_ALU_MUL_K: /* A *= K */
317 if (K <= 16383)
318 /* mhi %r5,K */
319 EMIT4_IMM(0xa75c0000, K);
68d9884d
HC		 320 else if (test_facility(34))
321 /* msfi %r5,<K> */
322 EMIT6_IMM(0xc2510000, K);
c10302ef
MS		 323 else
324 /* ms %r5,<d(K)>(%r13) */
325 EMIT4_DISP(0x7150d000, EMIT_CONST(K));
326 break;
327 case BPF_S_ALU_DIV_X: /* A /= X */
328 jit->seen |= SEEN_XREG | SEEN_RET0;
329 /* ltr %r12,%r12 */
330 EMIT2(0x12cc);
331 /* jz <ret0> */
332 EMIT4_PCREL(0xa7840000, (jit->ret0_ip - jit->prg));
333 /* lhi %r4,0 */
334 EMIT4(0xa7480000);
335 /* dr %r4,%r12 */
336 EMIT2(0x1d4c);
337 break;
338 case BPF_S_ALU_DIV_K: /* A = reciprocal_divide(A, K) */
339 /* m %r4,<d(K)>(%r13) */
340 EMIT4_DISP(0x5c40d000, EMIT_CONST(K));
32472745
HC		 341 /* lr %r5,%r4 */
342 EMIT2(0x1854);
343 break;
344 case BPF_S_ALU_MOD_X: /* A %= X */
345 jit->seen |= SEEN_XREG | SEEN_RET0;
346 /* ltr %r12,%r12 */
347 EMIT2(0x12cc);
348 /* jz <ret0> */
349 EMIT4_PCREL(0xa7840000, (jit->ret0_ip - jit->prg));
350 /* lhi %r4,0 */
351 EMIT4(0xa7480000);
352 /* dr %r4,%r12 */
353 EMIT2(0x1d4c);
354 /* lr %r5,%r4 */
355 EMIT2(0x1854);
356 break;
357 case BPF_S_ALU_MOD_K: /* A %= K */
358 /* lhi %r4,0 */
359 EMIT4(0xa7480000);
360 /* d %r4,<d(K)>(%r13) */
361 EMIT4_DISP(0x5d40d000, EMIT_CONST(K));
c10302ef
MS		 362 /* lr %r5,%r4 */
363 EMIT2(0x1854);
364 break;
365 case BPF_S_ALU_AND_X: /* A &= X */
366 jit->seen |= SEEN_XREG;
367 /* nr %r5,%r12 */
368 EMIT2(0x145c);
369 break;
370 case BPF_S_ALU_AND_K: /* A &= K */
68d9884d
HC		 371 if (test_facility(21))
372 /* nilf %r5,<K> */
373 EMIT6_IMM(0xc05b0000, K);
374 else
375 /* n %r5,<d(K)>(%r13) */
376 EMIT4_DISP(0x5450d000, EMIT_CONST(K));
c10302ef
MS		 377 break;
378 case BPF_S_ALU_OR_X: /* A |= X */
379 jit->seen |= SEEN_XREG;
380 /* or %r5,%r12 */
381 EMIT2(0x165c);
382 break;
383 case BPF_S_ALU_OR_K: /* A |= K */
68d9884d
HC		 384 if (test_facility(21))
385 /* oilf %r5,<K> */
386 EMIT6_IMM(0xc05d0000, K);
387 else
388 /* o %r5,<d(K)>(%r13) */
389 EMIT4_DISP(0x5650d000, EMIT_CONST(K));
c10302ef 390 break;
c59eed11 391 case BPF_S_ANC_ALU_XOR_X: /* A ^= X; */
916908df 392 case BPF_S_ALU_XOR_X:
c59eed11
HC		 393 jit->seen |= SEEN_XREG;
394 /* xr %r5,%r12 */
395 EMIT2(0x175c);
396 break;
916908df
HC		 397 case BPF_S_ALU_XOR_K: /* A ^= K */
398 if (!K)
399 break;
400 /* x %r5,<d(K)>(%r13) */
401 EMIT4_DISP(0x5750d000, EMIT_CONST(K));
402 break;
c10302ef
MS		 403 case BPF_S_ALU_LSH_X: /* A <<= X; */
404 jit->seen |= SEEN_XREG;
405 /* sll %r5,0(%r12) */
406 EMIT4(0x8950c000);
407 break;
408 case BPF_S_ALU_LSH_K: /* A <<= K */
409 if (K == 0)
410 break;
411 /* sll %r5,K */
412 EMIT4_DISP(0x89500000, K);
413 break;
414 case BPF_S_ALU_RSH_X: /* A >>= X; */
415 jit->seen |= SEEN_XREG;
416 /* srl %r5,0(%r12) */
417 EMIT4(0x8850c000);
418 break;
419 case BPF_S_ALU_RSH_K: /* A >>= K; */
420 if (K == 0)
421 break;
422 /* srl %r5,K */
423 EMIT4_DISP(0x88500000, K);
424 break;
425 case BPF_S_ALU_NEG: /* A = -A */
426 /* lnr %r5,%r5 */
427 EMIT2(0x1155);
428 break;
429 case BPF_S_JMP_JA: /* ip += K */
430 offset = addrs[i + K] + jit->start - jit->prg;
431 EMIT4_PCREL(0xa7f40000, offset);
432 break;
433 case BPF_S_JMP_JGT_K: /* ip += (A > K) ? jt : jf */
434 mask = 0x200000; /* jh */
435 goto kbranch;
436 case BPF_S_JMP_JGE_K: /* ip += (A >= K) ? jt : jf */
437 mask = 0xa00000; /* jhe */
438 goto kbranch;
439 case BPF_S_JMP_JEQ_K: /* ip += (A == K) ? jt : jf */
440 mask = 0x800000; /* je */
441kbranch: /* Emit compare if the branch targets are different */
442 if (filter->jt != filter->jf) {
443 if (K <= 16383)
444 /* chi %r5,<K> */
445 EMIT4_IMM(0xa75e0000, K);
68d9884d
HC		 446 else if (test_facility(21))
447 /* clfi %r5,<K> */
448 EMIT6_IMM(0xc25f0000, K);
c10302ef
MS		 449 else
450 /* c %r5,<d(K)>(%r13) */
451 EMIT4_DISP(0x5950d000, EMIT_CONST(K));
452 }
453branch: if (filter->jt == filter->jf) {
454 if (filter->jt == 0)
455 break;
456 /* j <jt> */
457 offset = addrs[i + filter->jt] + jit->start - jit->prg;
458 EMIT4_PCREL(0xa7f40000, offset);
459 break;
460 }
461 if (filter->jt != 0) {
462 /* brc <mask>,<jt> */
463 offset = addrs[i + filter->jt] + jit->start - jit->prg;
464 EMIT4_PCREL(0xa7040000 | mask, offset);
465 }
466 if (filter->jf != 0) {
467 /* brc <mask^15>,<jf> */
468 offset = addrs[i + filter->jf] + jit->start - jit->prg;
469 EMIT4_PCREL(0xa7040000 | (mask ^ 0xf00000), offset);
470 }
471 break;
472 case BPF_S_JMP_JSET_K: /* ip += (A & K) ? jt : jf */
473 mask = 0x700000; /* jnz */
474 /* Emit test if the branch targets are different */
475 if (filter->jt != filter->jf) {
476 if (K > 65535) {
477 /* lr %r4,%r5 */
478 EMIT2(0x1845);
479 /* n %r4,<d(K)>(%r13) */
480 EMIT4_DISP(0x5440d000, EMIT_CONST(K));
481 } else
482 /* tmll %r5,K */
483 EMIT4_IMM(0xa7510000, K);
484 }
485 goto branch;
486 case BPF_S_JMP_JGT_X: /* ip += (A > X) ? jt : jf */
487 mask = 0x200000; /* jh */
488 goto xbranch;
489 case BPF_S_JMP_JGE_X: /* ip += (A >= X) ? jt : jf */
490 mask = 0xa00000; /* jhe */
491 goto xbranch;
492 case BPF_S_JMP_JEQ_X: /* ip += (A == X) ? jt : jf */
493 mask = 0x800000; /* je */
494xbranch: /* Emit compare if the branch targets are different */
495 if (filter->jt != filter->jf) {
496 jit->seen |= SEEN_XREG;
497 /* cr %r5,%r12 */
498 EMIT2(0x195c);
499 }
500 goto branch;
501 case BPF_S_JMP_JSET_X: /* ip += (A & X) ? jt : jf */
502 mask = 0x700000; /* jnz */
503 /* Emit test if the branch targets are different */
504 if (filter->jt != filter->jf) {
505 jit->seen |= SEEN_XREG;
506 /* lr %r4,%r5 */
507 EMIT2(0x1845);
508 /* nr %r4,%r12 */
509 EMIT2(0x144c);
510 }
511 goto branch;
512 case BPF_S_LD_W_ABS: /* A = *(u32 *) (skb->data+K) */
513 jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_WORD;
514 offset = jit->off_load_word;
515 goto load_abs;
516 case BPF_S_LD_H_ABS: /* A = *(u16 *) (skb->data+K) */
517 jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_HALF;
518 offset = jit->off_load_half;
519 goto load_abs;
520 case BPF_S_LD_B_ABS: /* A = *(u8 *) (skb->data+K) */
521 jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_BYTE;
522 offset = jit->off_load_byte;
523load_abs: if ((int) K < 0)
524 goto out;
525call_fn: /* lg %r1,<d(function)>(%r13) */
526 EMIT6_DISP(0xe310d000, 0x0004, offset);
527 /* l %r3,<d(K)>(%r13) */
528 EMIT4_DISP(0x5830d000, EMIT_CONST(K));
529 /* basr %r8,%r1 */
530 EMIT2(0x0d81);
531 /* jnz <ret0> */
532 EMIT4_PCREL(0xa7740000, (jit->ret0_ip - jit->prg));
533 break;
534 case BPF_S_LD_W_IND: /* A = *(u32 *) (skb->data+K+X) */
535 jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IWORD;
536 offset = jit->off_load_iword;
537 goto call_fn;
538 case BPF_S_LD_H_IND: /* A = *(u16 *) (skb->data+K+X) */
539 jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IHALF;
540 offset = jit->off_load_ihalf;
541 goto call_fn;
542 case BPF_S_LD_B_IND: /* A = *(u8 *) (skb->data+K+X) */
543 jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IBYTE;
544 offset = jit->off_load_ibyte;
545 goto call_fn;
546 case BPF_S_LDX_B_MSH:
547 /* X = (*(u8 *)(skb->data+K) & 0xf) << 2 */
548 jit->seen |= SEEN_RET0;
549 if ((int) K < 0) {
550 /* j <ret0> */
551 EMIT4_PCREL(0xa7f40000, (jit->ret0_ip - jit->prg));
552 break;
553 }
554 jit->seen |= SEEN_DATAREF | SEEN_LOAD_BMSH;
555 offset = jit->off_load_bmsh;
556 goto call_fn;
557 case BPF_S_LD_W_LEN: /* A = skb->len; */
558 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
559 /* l %r5,<d(len)>(%r2) */
560 EMIT4_DISP(0x58502000, offsetof(struct sk_buff, len));
561 break;
562 case BPF_S_LDX_W_LEN: /* X = skb->len; */
563 jit->seen |= SEEN_XREG;
564 /* l %r12,<d(len)>(%r2) */
565 EMIT4_DISP(0x58c02000, offsetof(struct sk_buff, len));
566 break;
567 case BPF_S_LD_IMM: /* A = K */
568 if (K <= 16383)
569 /* lhi %r5,K */
570 EMIT4_IMM(0xa7580000, K);
68d9884d
HC		 571 else if (test_facility(21))
572 /* llilf %r5,<K> */
573 EMIT6_IMM(0xc05f0000, K);
c10302ef
MS		 574 else
575 /* l %r5,<d(K)>(%r13) */
576 EMIT4_DISP(0x5850d000, EMIT_CONST(K));
577 break;
578 case BPF_S_LDX_IMM: /* X = K */
579 jit->seen |= SEEN_XREG;
580 if (K <= 16383)
581 /* lhi %r12,<K> */
582 EMIT4_IMM(0xa7c80000, K);
68d9884d
HC		 583 else if (test_facility(21))
584 /* llilf %r12,<K> */
585 EMIT6_IMM(0xc0cf0000, K);
c10302ef
MS		 586 else
587 /* l %r12,<d(K)>(%r13) */
588 EMIT4_DISP(0x58c0d000, EMIT_CONST(K));
589 break;
590 case BPF_S_LD_MEM: /* A = mem[K] */
591 jit->seen |= SEEN_MEM;
592 /* l %r5,<K>(%r15) */
593 EMIT4_DISP(0x5850f000,
594 (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
595 break;
596 case BPF_S_LDX_MEM: /* X = mem[K] */
597 jit->seen |= SEEN_XREG | SEEN_MEM;
598 /* l %r12,<K>(%r15) */
599 EMIT4_DISP(0x58c0f000,
600 (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
601 break;
602 case BPF_S_MISC_TAX: /* X = A */
603 jit->seen |= SEEN_XREG;
604 /* lr %r12,%r5 */
605 EMIT2(0x18c5);
606 break;
607 case BPF_S_MISC_TXA: /* A = X */
608 jit->seen |= SEEN_XREG;
609 /* lr %r5,%r12 */
610 EMIT2(0x185c);
611 break;
612 case BPF_S_RET_K:
613 if (K == 0) {
614 jit->seen |= SEEN_RET0;
615 if (last)
616 break;
617 /* j <ret0> */
618 EMIT4_PCREL(0xa7f40000, jit->ret0_ip - jit->prg);
619 } else {
620 if (K <= 16383)
621 /* lghi %r2,K */
622 EMIT4_IMM(0xa7290000, K);
623 else
624 /* llgf %r2,<K>(%r13) */
625 EMIT6_DISP(0xe320d000, 0x0016, EMIT_CONST(K));
626 /* j <exit> */
627 if (last && !(jit->seen & SEEN_RET0))
628 break;
629 EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);
630 }
631 break;
632 case BPF_S_RET_A:
633 /* llgfr %r2,%r5 */
634 EMIT4(0xb9160025);
635 /* j <exit> */
636 EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);
637 break;
638 case BPF_S_ST: /* mem[K] = A */
639 jit->seen |= SEEN_MEM;
640 /* st %r5,<K>(%r15) */
641 EMIT4_DISP(0x5050f000,
642 (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
643 break;
644 case BPF_S_STX: /* mem[K] = X : mov %ebx,off8(%rbp) */
645 jit->seen |= SEEN_XREG | SEEN_MEM;
646 /* st %r12,<K>(%r15) */
647 EMIT4_DISP(0x50c0f000,
648 (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
649 break;
650 case BPF_S_ANC_PROTOCOL: /* A = ntohs(skb->protocol); */
651 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2);
652 /* lhi %r5,0 */
653 EMIT4(0xa7580000);
654 /* icm %r5,3,<d(protocol)>(%r2) */
655 EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, protocol));
656 break;
657 case BPF_S_ANC_IFINDEX: /* if (!skb->dev) return 0;
658 * A = skb->dev->ifindex */
659 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
660 jit->seen |= SEEN_RET0;
661 /* lg %r1,<d(dev)>(%r2) */
662 EMIT6_DISP(0xe3102000, 0x0004, offsetof(struct sk_buff, dev));
663 /* ltgr %r1,%r1 */
664 EMIT4(0xb9020011);
665 /* jz <ret0> */
666 EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg);
667 /* l %r5,<d(ifindex)>(%r1) */
668 EMIT4_DISP(0x58501000, offsetof(struct net_device, ifindex));
669 break;
670 case BPF_S_ANC_MARK: /* A = skb->mark */
671 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
672 /* l %r5,<d(mark)>(%r2) */
673 EMIT4_DISP(0x58502000, offsetof(struct sk_buff, mark));
674 break;
675 case BPF_S_ANC_QUEUE: /* A = skb->queue_mapping */
676 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2);
677 /* lhi %r5,0 */
678 EMIT4(0xa7580000);
679 /* icm %r5,3,<d(queue_mapping)>(%r2) */
680 EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, queue_mapping));
681 break;
682 case BPF_S_ANC_HATYPE: /* if (!skb->dev) return 0;
683 * A = skb->dev->type */
684 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2);
685 jit->seen |= SEEN_RET0;
686 /* lg %r1,<d(dev)>(%r2) */
687 EMIT6_DISP(0xe3102000, 0x0004, offsetof(struct sk_buff, dev));
688 /* ltgr %r1,%r1 */
689 EMIT4(0xb9020011);
690 /* jz <ret0> */
691 EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg);
692 /* lhi %r5,0 */
693 EMIT4(0xa7580000);
694 /* icm %r5,3,<d(type)>(%r1) */
695 EMIT4_DISP(0xbf531000, offsetof(struct net_device, type));
696 break;
697 case BPF_S_ANC_RXHASH: /* A = skb->rxhash */
698 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, rxhash) != 4);
699 /* l %r5,<d(rxhash)>(%r2) */
700 EMIT4_DISP(0x58502000, offsetof(struct sk_buff, rxhash));
701 break;
702 case BPF_S_ANC_CPU: /* A = smp_processor_id() */
703#ifdef CONFIG_SMP
704 /* l %r5,<d(cpu_nr)> */
705 EMIT4_DISP(0x58500000, offsetof(struct _lowcore, cpu_nr));
706#else
707 /* lhi %r5,0 */
708 EMIT4(0xa7580000);
709#endif
710 break;
711 default: /* too complex, give up */
712 goto out;
713 }
714 addrs[i] = jit->prg - jit->start;
715 return 0;
716out:
717 return -1;
718}
719
720void bpf_jit_compile(struct sk_filter *fp)
721{
722 unsigned long size, prg_len, lit_len;
723 struct bpf_jit jit, cjit;
724 unsigned int *addrs;
725 int pass, i;
726
727 if (!bpf_jit_enable)
728 return;
729 addrs = kmalloc(fp->len * sizeof(*addrs), GFP_KERNEL);
730 if (addrs == NULL)
731 return;
732 memset(addrs, 0, fp->len * sizeof(*addrs));
733 memset(&jit, 0, sizeof(cjit));
734 memset(&cjit, 0, sizeof(cjit));
735
736 for (pass = 0; pass < 10; pass++) {
737 jit.prg = jit.start;
738 jit.lit = jit.mid;
739
740 bpf_jit_prologue(&jit);
741 bpf_jit_noleaks(&jit, fp->insns);
742 for (i = 0; i < fp->len; i++) {
743 if (bpf_jit_insn(&jit, fp->insns + i, addrs, i,
744 i == fp->len - 1))
745 goto out;
746 }
747 bpf_jit_epilogue(&jit);
748 if (jit.start) {
749 WARN_ON(jit.prg > cjit.prg || jit.lit > cjit.lit);
750 if (memcmp(&jit, &cjit, sizeof(jit)) == 0)
751 break;
752 } else if (jit.prg == cjit.prg && jit.lit == cjit.lit) {
753 prg_len = jit.prg - jit.start;
754 lit_len = jit.lit - jit.mid;
755 size = max_t(unsigned long, prg_len + lit_len,
756 sizeof(struct work_struct));
757 if (size >= BPF_SIZE_MAX)
758 goto out;
759 jit.start = module_alloc(size);
760 if (!jit.start)
761 goto out;
762 jit.prg = jit.mid = jit.start + prg_len;
763 jit.lit = jit.end = jit.start + prg_len + lit_len;
764 jit.base_ip += (unsigned long) jit.start;
765 jit.exit_ip += (unsigned long) jit.start;
766 jit.ret0_ip += (unsigned long) jit.start;
767 }
768 cjit = jit;
769 }
770 if (bpf_jit_enable > 1) {
771 pr_err("flen=%d proglen=%lu pass=%d image=%p\n",
772 fp->len, jit.end - jit.start, pass, jit.start);
773 if (jit.start) {
774 printk(KERN_ERR "JIT code:\n");
775 print_fn_code(jit.start, jit.mid - jit.start);
776 print_hex_dump(KERN_ERR, "JIT literals:\n",
777 DUMP_PREFIX_ADDRESS, 16, 1,
778 jit.mid, jit.end - jit.mid, false);
779 }
780 }
781 if (jit.start)
782 fp->bpf_func = (void *) jit.start;
783out:
784 kfree(addrs);
785}
786
787static void jit_free_defer(struct work_struct *arg)
788{
789 module_free(NULL, arg);
790}
791
792/* run from softirq, we must use a work_struct to call
793 * module_free() from process context
794 */
795void bpf_jit_free(struct sk_filter *fp)
796{
797 struct work_struct *work;
798
799 if (fp->bpf_func == sk_run_filter)
800 return;
801 work = (struct work_struct *)fp->bpf_func;
802 INIT_WORK(work, jit_free_defer);
803 schedule_work(work);
804}
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