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[deliverable/linux.git] / arch / sparc / net / bpf_jit_comp.c
1 #include <linux/moduleloader.h>
2 #include <linux/workqueue.h>
3 #include <linux/netdevice.h>
4 #include <linux/filter.h>
5 #include <linux/cache.h>
6 #include <linux/if_vlan.h>
7
8 #include <asm/cacheflush.h>
9 #include <asm/ptrace.h>
10
11 #include "bpf_jit.h"
12
13 int bpf_jit_enable __read_mostly;
14
15 static inline bool is_simm13(unsigned int value)
16 {
17 return value + 0x1000 < 0x2000;
18 }
19
20 static void bpf_flush_icache(void *start_, void *end_)
21 {
22 #ifdef CONFIG_SPARC64
23 /* Cheetah's I-cache is fully coherent. */
24 if (tlb_type == spitfire) {
25 unsigned long start = (unsigned long) start_;
26 unsigned long end = (unsigned long) end_;
27
28 start &= ~7UL;
29 end = (end + 7UL) & ~7UL;
30 while (start < end) {
31 flushi(start);
32 start += 32;
33 }
34 }
35 #endif
36 }
37
38 #define SEEN_DATAREF 1 /* might call external helpers */
39 #define SEEN_XREG 2 /* ebx is used */
40 #define SEEN_MEM 4 /* use mem[] for temporary storage */
41
42 #define S13(X) ((X) & 0x1fff)
43 #define IMMED 0x00002000
44 #define RD(X) ((X) << 25)
45 #define RS1(X) ((X) << 14)
46 #define RS2(X) ((X))
47 #define OP(X) ((X) << 30)
48 #define OP2(X) ((X) << 22)
49 #define OP3(X) ((X) << 19)
50 #define COND(X) ((X) << 25)
51 #define F1(X) OP(X)
52 #define F2(X, Y) (OP(X) | OP2(Y))
53 #define F3(X, Y) (OP(X) | OP3(Y))
54
55 #define CONDN COND(0x0)
56 #define CONDE COND(0x1)
57 #define CONDLE COND(0x2)
58 #define CONDL COND(0x3)
59 #define CONDLEU COND(0x4)
60 #define CONDCS COND(0x5)
61 #define CONDNEG COND(0x6)
62 #define CONDVC COND(0x7)
63 #define CONDA COND(0x8)
64 #define CONDNE COND(0x9)
65 #define CONDG COND(0xa)
66 #define CONDGE COND(0xb)
67 #define CONDGU COND(0xc)
68 #define CONDCC COND(0xd)
69 #define CONDPOS COND(0xe)
70 #define CONDVS COND(0xf)
71
72 #define CONDGEU CONDCC
73 #define CONDLU CONDCS
74
75 #define WDISP22(X) (((X) >> 2) & 0x3fffff)
76
77 #define BA (F2(0, 2) | CONDA)
78 #define BGU (F2(0, 2) | CONDGU)
79 #define BLEU (F2(0, 2) | CONDLEU)
80 #define BGEU (F2(0, 2) | CONDGEU)
81 #define BLU (F2(0, 2) | CONDLU)
82 #define BE (F2(0, 2) | CONDE)
83 #define BNE (F2(0, 2) | CONDNE)
84
85 #ifdef CONFIG_SPARC64
86 #define BNE_PTR (F2(0, 1) | CONDNE | (2 << 20))
87 #else
88 #define BNE_PTR BNE
89 #endif
90
91 #define SETHI(K, REG) \
92 (F2(0, 0x4) | RD(REG) | (((K) >> 10) & 0x3fffff))
93 #define OR_LO(K, REG) \
94 (F3(2, 0x02) | IMMED | RS1(REG) | ((K) & 0x3ff) | RD(REG))
95
96 #define ADD F3(2, 0x00)
97 #define AND F3(2, 0x01)
98 #define ANDCC F3(2, 0x11)
99 #define OR F3(2, 0x02)
100 #define XOR F3(2, 0x03)
101 #define SUB F3(2, 0x04)
102 #define SUBCC F3(2, 0x14)
103 #define MUL F3(2, 0x0a) /* umul */
104 #define DIV F3(2, 0x0e) /* udiv */
105 #define SLL F3(2, 0x25)
106 #define SRL F3(2, 0x26)
107 #define JMPL F3(2, 0x38)
108 #define CALL F1(1)
109 #define BR F2(0, 0x01)
110 #define RD_Y F3(2, 0x28)
111 #define WR_Y F3(2, 0x30)
112
113 #define LD32 F3(3, 0x00)
114 #define LD8 F3(3, 0x01)
115 #define LD16 F3(3, 0x02)
116 #define LD64 F3(3, 0x0b)
117 #define ST32 F3(3, 0x04)
118
119 #ifdef CONFIG_SPARC64
120 #define LDPTR LD64
121 #define BASE_STACKFRAME 176
122 #else
123 #define LDPTR LD32
124 #define BASE_STACKFRAME 96
125 #endif
126
127 #define LD32I (LD32 | IMMED)
128 #define LD8I (LD8 | IMMED)
129 #define LD16I (LD16 | IMMED)
130 #define LD64I (LD64 | IMMED)
131 #define LDPTRI (LDPTR | IMMED)
132 #define ST32I (ST32 | IMMED)
133
134 #define emit_nop() \
135 do { \
136 *prog++ = SETHI(0, G0); \
137 } while (0)
138
139 #define emit_neg() \
140 do { /* sub %g0, r_A, r_A */ \
141 *prog++ = SUB | RS1(G0) | RS2(r_A) | RD(r_A); \
142 } while (0)
143
144 #define emit_reg_move(FROM, TO) \
145 do { /* or %g0, FROM, TO */ \
146 *prog++ = OR | RS1(G0) | RS2(FROM) | RD(TO); \
147 } while (0)
148
149 #define emit_clear(REG) \
150 do { /* or %g0, %g0, REG */ \
151 *prog++ = OR | RS1(G0) | RS2(G0) | RD(REG); \
152 } while (0)
153
154 #define emit_set_const(K, REG) \
155 do { /* sethi %hi(K), REG */ \
156 *prog++ = SETHI(K, REG); \
157 /* or REG, %lo(K), REG */ \
158 *prog++ = OR_LO(K, REG); \
159 } while (0)
160
161 /* Emit
162 *
163 * OP r_A, r_X, r_A
164 */
165 #define emit_alu_X(OPCODE) \
166 do { \
167 seen |= SEEN_XREG; \
168 *prog++ = OPCODE | RS1(r_A) | RS2(r_X) | RD(r_A); \
169 } while (0)
170
171 /* Emit either:
172 *
173 * OP r_A, K, r_A
174 *
175 * or
176 *
177 * sethi %hi(K), r_TMP
178 * or r_TMP, %lo(K), r_TMP
179 * OP r_A, r_TMP, r_A
180 *
181 * depending upon whether K fits in a signed 13-bit
182 * immediate instruction field. Emit nothing if K
183 * is zero.
184 */
185 #define emit_alu_K(OPCODE, K) \
186 do { \
187 if (K) { \
188 unsigned int _insn = OPCODE; \
189 _insn |= RS1(r_A) | RD(r_A); \
190 if (is_simm13(K)) { \
191 *prog++ = _insn | IMMED | S13(K); \
192 } else { \
193 emit_set_const(K, r_TMP); \
194 *prog++ = _insn | RS2(r_TMP); \
195 } \
196 } \
197 } while (0)
198
199 #define emit_loadimm(K, DEST) \
200 do { \
201 if (is_simm13(K)) { \
202 /* or %g0, K, DEST */ \
203 *prog++ = OR | IMMED | RS1(G0) | S13(K) | RD(DEST); \
204 } else { \
205 emit_set_const(K, DEST); \
206 } \
207 } while (0)
208
209 #define emit_loadptr(BASE, STRUCT, FIELD, DEST) \
210 do { unsigned int _off = offsetof(STRUCT, FIELD); \
211 BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(void *)); \
212 *prog++ = LDPTRI | RS1(BASE) | S13(_off) | RD(DEST); \
213 } while (0)
214
215 #define emit_load32(BASE, STRUCT, FIELD, DEST) \
216 do { unsigned int _off = offsetof(STRUCT, FIELD); \
217 BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u32)); \
218 *prog++ = LD32I | RS1(BASE) | S13(_off) | RD(DEST); \
219 } while (0)
220
221 #define emit_load16(BASE, STRUCT, FIELD, DEST) \
222 do { unsigned int _off = offsetof(STRUCT, FIELD); \
223 BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u16)); \
224 *prog++ = LD16I | RS1(BASE) | S13(_off) | RD(DEST); \
225 } while (0)
226
227 #define __emit_load8(BASE, STRUCT, FIELD, DEST) \
228 do { unsigned int _off = offsetof(STRUCT, FIELD); \
229 *prog++ = LD8I | RS1(BASE) | S13(_off) | RD(DEST); \
230 } while (0)
231
232 #define emit_load8(BASE, STRUCT, FIELD, DEST) \
233 do { BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u8)); \
234 __emit_load8(BASE, STRUCT, FIELD, DEST); \
235 } while (0)
236
237 #define emit_ldmem(OFF, DEST) \
238 do { *prog++ = LD32I | RS1(FP) | S13(-(OFF)) | RD(DEST); \
239 } while (0)
240
241 #define emit_stmem(OFF, SRC) \
242 do { *prog++ = LD32I | RS1(FP) | S13(-(OFF)) | RD(SRC); \
243 } while (0)
244
245 #ifdef CONFIG_SMP
246 #ifdef CONFIG_SPARC64
247 #define emit_load_cpu(REG) \
248 emit_load16(G6, struct thread_info, cpu, REG)
249 #else
250 #define emit_load_cpu(REG) \
251 emit_load32(G6, struct thread_info, cpu, REG)
252 #endif
253 #else
254 #define emit_load_cpu(REG) emit_clear(REG)
255 #endif
256
257 #define emit_skb_loadptr(FIELD, DEST) \
258 emit_loadptr(r_SKB, struct sk_buff, FIELD, DEST)
259 #define emit_skb_load32(FIELD, DEST) \
260 emit_load32(r_SKB, struct sk_buff, FIELD, DEST)
261 #define emit_skb_load16(FIELD, DEST) \
262 emit_load16(r_SKB, struct sk_buff, FIELD, DEST)
263 #define __emit_skb_load8(FIELD, DEST) \
264 __emit_load8(r_SKB, struct sk_buff, FIELD, DEST)
265 #define emit_skb_load8(FIELD, DEST) \
266 emit_load8(r_SKB, struct sk_buff, FIELD, DEST)
267
268 #define emit_jmpl(BASE, IMM_OFF, LREG) \
269 *prog++ = (JMPL | IMMED | RS1(BASE) | S13(IMM_OFF) | RD(LREG))
270
271 #define emit_call(FUNC) \
272 do { void *_here = image + addrs[i] - 8; \
273 unsigned int _off = (void *)(FUNC) - _here; \
274 *prog++ = CALL | (((_off) >> 2) & 0x3fffffff); \
275 emit_nop(); \
276 } while (0)
277
278 #define emit_branch(BR_OPC, DEST) \
279 do { unsigned int _here = addrs[i] - 8; \
280 *prog++ = BR_OPC | WDISP22((DEST) - _here); \
281 } while (0)
282
283 #define emit_branch_off(BR_OPC, OFF) \
284 do { *prog++ = BR_OPC | WDISP22(OFF); \
285 } while (0)
286
287 #define emit_jump(DEST) emit_branch(BA, DEST)
288
289 #define emit_read_y(REG) *prog++ = RD_Y | RD(REG)
290 #define emit_write_y(REG) *prog++ = WR_Y | IMMED | RS1(REG) | S13(0)
291
292 #define emit_cmp(R1, R2) \
293 *prog++ = (SUBCC | RS1(R1) | RS2(R2) | RD(G0))
294
295 #define emit_cmpi(R1, IMM) \
296 *prog++ = (SUBCC | IMMED | RS1(R1) | S13(IMM) | RD(G0));
297
298 #define emit_btst(R1, R2) \
299 *prog++ = (ANDCC | RS1(R1) | RS2(R2) | RD(G0))
300
301 #define emit_btsti(R1, IMM) \
302 *prog++ = (ANDCC | IMMED | RS1(R1) | S13(IMM) | RD(G0));
303
304 #define emit_sub(R1, R2, R3) \
305 *prog++ = (SUB | RS1(R1) | RS2(R2) | RD(R3))
306
307 #define emit_subi(R1, IMM, R3) \
308 *prog++ = (SUB | IMMED | RS1(R1) | S13(IMM) | RD(R3))
309
310 #define emit_add(R1, R2, R3) \
311 *prog++ = (ADD | RS1(R1) | RS2(R2) | RD(R3))
312
313 #define emit_addi(R1, IMM, R3) \
314 *prog++ = (ADD | IMMED | RS1(R1) | S13(IMM) | RD(R3))
315
316 #define emit_and(R1, R2, R3) \
317 *prog++ = (AND | RS1(R1) | RS2(R2) | RD(R3))
318
319 #define emit_andi(R1, IMM, R3) \
320 *prog++ = (AND | IMMED | RS1(R1) | S13(IMM) | RD(R3))
321
322 #define emit_alloc_stack(SZ) \
323 *prog++ = (SUB | IMMED | RS1(SP) | S13(SZ) | RD(SP))
324
325 #define emit_release_stack(SZ) \
326 *prog++ = (ADD | IMMED | RS1(SP) | S13(SZ) | RD(SP))
327
328 /* A note about branch offset calculations. The addrs[] array,
329 * indexed by BPF instruction, records the address after all the
330 * sparc instructions emitted for that BPF instruction.
331 *
332 * The most common case is to emit a branch at the end of such
333 * a code sequence. So this would be two instructions, the
334 * branch and it's delay slot.
335 *
336 * Therefore by default the branch emitters calculate the branch
337 * offset field as:
338 *
339 * destination - (addrs[i] - 8)
340 *
341 * This "addrs[i] - 8" is the address of the branch itself or
342 * what "." would be in assembler notation. The "8" part is
343 * how we take into consideration the branch and it's delay
344 * slot mentioned above.
345 *
346 * Sometimes we need to emit a branch earlier in the code
347 * sequence. And in these situations we adjust "destination"
348 * to accomodate this difference. For example, if we needed
349 * to emit a branch (and it's delay slot) right before the
350 * final instruction emitted for a BPF opcode, we'd use
351 * "destination + 4" instead of just plain "destination" above.
352 *
353 * This is why you see all of these funny emit_branch() and
354 * emit_jump() calls with adjusted offsets.
355 */
356
357 void bpf_jit_compile(struct sk_filter *fp)
358 {
359 unsigned int cleanup_addr, proglen, oldproglen = 0;
360 u32 temp[8], *prog, *func, seen = 0, pass;
361 const struct sock_filter *filter = fp->insns;
362 int i, flen = fp->len, pc_ret0 = -1;
363 unsigned int *addrs;
364 void *image;
365
366 if (!bpf_jit_enable)
367 return;
368
369 addrs = kmalloc(flen * sizeof(*addrs), GFP_KERNEL);
370 if (addrs == NULL)
371 return;
372
373 /* Before first pass, make a rough estimation of addrs[]
374 * each bpf instruction is translated to less than 64 bytes
375 */
376 for (proglen = 0, i = 0; i < flen; i++) {
377 proglen += 64;
378 addrs[i] = proglen;
379 }
380 cleanup_addr = proglen; /* epilogue address */
381 image = NULL;
382 for (pass = 0; pass < 10; pass++) {
383 u8 seen_or_pass0 = (pass == 0) ? (SEEN_XREG | SEEN_DATAREF | SEEN_MEM) : seen;
384
385 /* no prologue/epilogue for trivial filters (RET something) */
386 proglen = 0;
387 prog = temp;
388
389 /* Prologue */
390 if (seen_or_pass0) {
391 if (seen_or_pass0 & SEEN_MEM) {
392 unsigned int sz = BASE_STACKFRAME;
393 sz += BPF_MEMWORDS * sizeof(u32);
394 emit_alloc_stack(sz);
395 }
396
397 /* Make sure we dont leek kernel memory. */
398 if (seen_or_pass0 & SEEN_XREG)
399 emit_clear(r_X);
400
401 /* If this filter needs to access skb data,
402 * load %o4 and %o5 with:
403 * %o4 = skb->len - skb->data_len
404 * %o5 = skb->data
405 * And also back up %o7 into r_saved_O7 so we can
406 * invoke the stubs using 'call'.
407 */
408 if (seen_or_pass0 & SEEN_DATAREF) {
409 emit_load32(r_SKB, struct sk_buff, len, r_HEADLEN);
410 emit_load32(r_SKB, struct sk_buff, data_len, r_TMP);
411 emit_sub(r_HEADLEN, r_TMP, r_HEADLEN);
412 emit_loadptr(r_SKB, struct sk_buff, data, r_SKB_DATA);
413 }
414 }
415 emit_reg_move(O7, r_saved_O7);
416
417 switch (filter[0].code) {
418 case BPF_S_RET_K:
419 case BPF_S_LD_W_LEN:
420 case BPF_S_ANC_PROTOCOL:
421 case BPF_S_ANC_PKTTYPE:
422 case BPF_S_ANC_IFINDEX:
423 case BPF_S_ANC_MARK:
424 case BPF_S_ANC_RXHASH:
425 case BPF_S_ANC_VLAN_TAG:
426 case BPF_S_ANC_VLAN_TAG_PRESENT:
427 case BPF_S_ANC_CPU:
428 case BPF_S_ANC_QUEUE:
429 case BPF_S_LD_W_ABS:
430 case BPF_S_LD_H_ABS:
431 case BPF_S_LD_B_ABS:
432 /* The first instruction sets the A register (or is
433 * a "RET 'constant'")
434 */
435 break;
436 default:
437 /* Make sure we dont leak kernel information to the
438 * user.
439 */
440 emit_clear(r_A); /* A = 0 */
441 }
442
443 for (i = 0; i < flen; i++) {
444 unsigned int K = filter[i].k;
445 unsigned int t_offset;
446 unsigned int f_offset;
447 u32 t_op, f_op;
448 int ilen;
449
450 switch (filter[i].code) {
451 case BPF_S_ALU_ADD_X: /* A += X; */
452 emit_alu_X(ADD);
453 break;
454 case BPF_S_ALU_ADD_K: /* A += K; */
455 emit_alu_K(ADD, K);
456 break;
457 case BPF_S_ALU_SUB_X: /* A -= X; */
458 emit_alu_X(SUB);
459 break;
460 case BPF_S_ALU_SUB_K: /* A -= K */
461 emit_alu_K(SUB, K);
462 break;
463 case BPF_S_ALU_AND_X: /* A &= X */
464 emit_alu_X(AND);
465 break;
466 case BPF_S_ALU_AND_K: /* A &= K */
467 emit_alu_K(AND, K);
468 break;
469 case BPF_S_ALU_OR_X: /* A |= X */
470 emit_alu_X(OR);
471 break;
472 case BPF_S_ALU_OR_K: /* A |= K */
473 emit_alu_K(OR, K);
474 break;
475 case BPF_S_ANC_ALU_XOR_X: /* A ^= X; */
476 case BPF_S_ALU_XOR_X:
477 emit_alu_X(XOR);
478 break;
479 case BPF_S_ALU_XOR_K: /* A ^= K */
480 emit_alu_K(XOR, K);
481 break;
482 case BPF_S_ALU_LSH_X: /* A <<= X */
483 emit_alu_X(SLL);
484 break;
485 case BPF_S_ALU_LSH_K: /* A <<= K */
486 emit_alu_K(SLL, K);
487 break;
488 case BPF_S_ALU_RSH_X: /* A >>= X */
489 emit_alu_X(SRL);
490 break;
491 case BPF_S_ALU_RSH_K: /* A >>= K */
492 emit_alu_K(SRL, K);
493 break;
494 case BPF_S_ALU_MUL_X: /* A *= X; */
495 emit_alu_X(MUL);
496 break;
497 case BPF_S_ALU_MUL_K: /* A *= K */
498 emit_alu_K(MUL, K);
499 break;
500 case BPF_S_ALU_DIV_K: /* A /= K with K != 0*/
501 if (K == 1)
502 break;
503 emit_write_y(G0);
504 #ifdef CONFIG_SPARC32
505 /* The Sparc v8 architecture requires
506 * three instructions between a %y
507 * register write and the first use.
508 */
509 emit_nop();
510 emit_nop();
511 emit_nop();
512 #endif
513 emit_alu_K(DIV, K);
514 break;
515 case BPF_S_ALU_DIV_X: /* A /= X; */
516 emit_cmpi(r_X, 0);
517 if (pc_ret0 > 0) {
518 t_offset = addrs[pc_ret0 - 1];
519 #ifdef CONFIG_SPARC32
520 emit_branch(BE, t_offset + 20);
521 #else
522 emit_branch(BE, t_offset + 8);
523 #endif
524 emit_nop(); /* delay slot */
525 } else {
526 emit_branch_off(BNE, 16);
527 emit_nop();
528 #ifdef CONFIG_SPARC32
529 emit_jump(cleanup_addr + 20);
530 #else
531 emit_jump(cleanup_addr + 8);
532 #endif
533 emit_clear(r_A);
534 }
535 emit_write_y(G0);
536 #ifdef CONFIG_SPARC32
537 /* The Sparc v8 architecture requires
538 * three instructions between a %y
539 * register write and the first use.
540 */
541 emit_nop();
542 emit_nop();
543 emit_nop();
544 #endif
545 emit_alu_X(DIV);
546 break;
547 case BPF_S_ALU_NEG:
548 emit_neg();
549 break;
550 case BPF_S_RET_K:
551 if (!K) {
552 if (pc_ret0 == -1)
553 pc_ret0 = i;
554 emit_clear(r_A);
555 } else {
556 emit_loadimm(K, r_A);
557 }
558 /* Fallthrough */
559 case BPF_S_RET_A:
560 if (seen_or_pass0) {
561 if (i != flen - 1) {
562 emit_jump(cleanup_addr);
563 emit_nop();
564 break;
565 }
566 if (seen_or_pass0 & SEEN_MEM) {
567 unsigned int sz = BASE_STACKFRAME;
568 sz += BPF_MEMWORDS * sizeof(u32);
569 emit_release_stack(sz);
570 }
571 }
572 /* jmpl %r_saved_O7 + 8, %g0 */
573 emit_jmpl(r_saved_O7, 8, G0);
574 emit_reg_move(r_A, O0); /* delay slot */
575 break;
576 case BPF_S_MISC_TAX:
577 seen |= SEEN_XREG;
578 emit_reg_move(r_A, r_X);
579 break;
580 case BPF_S_MISC_TXA:
581 seen |= SEEN_XREG;
582 emit_reg_move(r_X, r_A);
583 break;
584 case BPF_S_ANC_CPU:
585 emit_load_cpu(r_A);
586 break;
587 case BPF_S_ANC_PROTOCOL:
588 emit_skb_load16(protocol, r_A);
589 break;
590 #if 0
591 /* GCC won't let us take the address of
592 * a bit field even though we very much
593 * know what we are doing here.
594 */
595 case BPF_S_ANC_PKTTYPE:
596 __emit_skb_load8(pkt_type, r_A);
597 emit_alu_K(SRL, 5);
598 break;
599 #endif
600 case BPF_S_ANC_IFINDEX:
601 emit_skb_loadptr(dev, r_A);
602 emit_cmpi(r_A, 0);
603 emit_branch(BNE_PTR, cleanup_addr + 4);
604 emit_nop();
605 emit_load32(r_A, struct net_device, ifindex, r_A);
606 break;
607 case BPF_S_ANC_MARK:
608 emit_skb_load32(mark, r_A);
609 break;
610 case BPF_S_ANC_QUEUE:
611 emit_skb_load16(queue_mapping, r_A);
612 break;
613 case BPF_S_ANC_HATYPE:
614 emit_skb_loadptr(dev, r_A);
615 emit_cmpi(r_A, 0);
616 emit_branch(BNE_PTR, cleanup_addr + 4);
617 emit_nop();
618 emit_load16(r_A, struct net_device, type, r_A);
619 break;
620 case BPF_S_ANC_RXHASH:
621 emit_skb_load32(hash, r_A);
622 break;
623 case BPF_S_ANC_VLAN_TAG:
624 case BPF_S_ANC_VLAN_TAG_PRESENT:
625 emit_skb_load16(vlan_tci, r_A);
626 if (filter[i].code == BPF_S_ANC_VLAN_TAG) {
627 emit_andi(r_A, VLAN_VID_MASK, r_A);
628 } else {
629 emit_loadimm(VLAN_TAG_PRESENT, r_TMP);
630 emit_and(r_A, r_TMP, r_A);
631 }
632 break;
633
634 case BPF_S_LD_IMM:
635 emit_loadimm(K, r_A);
636 break;
637 case BPF_S_LDX_IMM:
638 emit_loadimm(K, r_X);
639 break;
640 case BPF_S_LD_MEM:
641 emit_ldmem(K * 4, r_A);
642 break;
643 case BPF_S_LDX_MEM:
644 emit_ldmem(K * 4, r_X);
645 break;
646 case BPF_S_ST:
647 emit_stmem(K * 4, r_A);
648 break;
649 case BPF_S_STX:
650 emit_stmem(K * 4, r_X);
651 break;
652
653 #define CHOOSE_LOAD_FUNC(K, func) \
654 ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
655
656 case BPF_S_LD_W_ABS:
657 func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_word);
658 common_load: seen |= SEEN_DATAREF;
659 emit_loadimm(K, r_OFF);
660 emit_call(func);
661 break;
662 case BPF_S_LD_H_ABS:
663 func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_half);
664 goto common_load;
665 case BPF_S_LD_B_ABS:
666 func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte);
667 goto common_load;
668 case BPF_S_LDX_B_MSH:
669 func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte_msh);
670 goto common_load;
671 case BPF_S_LD_W_IND:
672 func = bpf_jit_load_word;
673 common_load_ind: seen |= SEEN_DATAREF | SEEN_XREG;
674 if (K) {
675 if (is_simm13(K)) {
676 emit_addi(r_X, K, r_OFF);
677 } else {
678 emit_loadimm(K, r_TMP);
679 emit_add(r_X, r_TMP, r_OFF);
680 }
681 } else {
682 emit_reg_move(r_X, r_OFF);
683 }
684 emit_call(func);
685 break;
686 case BPF_S_LD_H_IND:
687 func = bpf_jit_load_half;
688 goto common_load_ind;
689 case BPF_S_LD_B_IND:
690 func = bpf_jit_load_byte;
691 goto common_load_ind;
692 case BPF_S_JMP_JA:
693 emit_jump(addrs[i + K]);
694 emit_nop();
695 break;
696
697 #define COND_SEL(CODE, TOP, FOP) \
698 case CODE: \
699 t_op = TOP; \
700 f_op = FOP; \
701 goto cond_branch
702
703 COND_SEL(BPF_S_JMP_JGT_K, BGU, BLEU);
704 COND_SEL(BPF_S_JMP_JGE_K, BGEU, BLU);
705 COND_SEL(BPF_S_JMP_JEQ_K, BE, BNE);
706 COND_SEL(BPF_S_JMP_JSET_K, BNE, BE);
707 COND_SEL(BPF_S_JMP_JGT_X, BGU, BLEU);
708 COND_SEL(BPF_S_JMP_JGE_X, BGEU, BLU);
709 COND_SEL(BPF_S_JMP_JEQ_X, BE, BNE);
710 COND_SEL(BPF_S_JMP_JSET_X, BNE, BE);
711
712 cond_branch: f_offset = addrs[i + filter[i].jf];
713 t_offset = addrs[i + filter[i].jt];
714
715 /* same targets, can avoid doing the test :) */
716 if (filter[i].jt == filter[i].jf) {
717 emit_jump(t_offset);
718 emit_nop();
719 break;
720 }
721
722 switch (filter[i].code) {
723 case BPF_S_JMP_JGT_X:
724 case BPF_S_JMP_JGE_X:
725 case BPF_S_JMP_JEQ_X:
726 seen |= SEEN_XREG;
727 emit_cmp(r_A, r_X);
728 break;
729 case BPF_S_JMP_JSET_X:
730 seen |= SEEN_XREG;
731 emit_btst(r_A, r_X);
732 break;
733 case BPF_S_JMP_JEQ_K:
734 case BPF_S_JMP_JGT_K:
735 case BPF_S_JMP_JGE_K:
736 if (is_simm13(K)) {
737 emit_cmpi(r_A, K);
738 } else {
739 emit_loadimm(K, r_TMP);
740 emit_cmp(r_A, r_TMP);
741 }
742 break;
743 case BPF_S_JMP_JSET_K:
744 if (is_simm13(K)) {
745 emit_btsti(r_A, K);
746 } else {
747 emit_loadimm(K, r_TMP);
748 emit_btst(r_A, r_TMP);
749 }
750 break;
751 }
752 if (filter[i].jt != 0) {
753 if (filter[i].jf)
754 t_offset += 8;
755 emit_branch(t_op, t_offset);
756 emit_nop(); /* delay slot */
757 if (filter[i].jf) {
758 emit_jump(f_offset);
759 emit_nop();
760 }
761 break;
762 }
763 emit_branch(f_op, f_offset);
764 emit_nop(); /* delay slot */
765 break;
766
767 default:
768 /* hmm, too complex filter, give up with jit compiler */
769 goto out;
770 }
771 ilen = (void *) prog - (void *) temp;
772 if (image) {
773 if (unlikely(proglen + ilen > oldproglen)) {
774 pr_err("bpb_jit_compile fatal error\n");
775 kfree(addrs);
776 module_free(NULL, image);
777 return;
778 }
779 memcpy(image + proglen, temp, ilen);
780 }
781 proglen += ilen;
782 addrs[i] = proglen;
783 prog = temp;
784 }
785 /* last bpf instruction is always a RET :
786 * use it to give the cleanup instruction(s) addr
787 */
788 cleanup_addr = proglen - 8; /* jmpl; mov r_A,%o0; */
789 if (seen_or_pass0 & SEEN_MEM)
790 cleanup_addr -= 4; /* add %sp, X, %sp; */
791
792 if (image) {
793 if (proglen != oldproglen)
794 pr_err("bpb_jit_compile proglen=%u != oldproglen=%u\n",
795 proglen, oldproglen);
796 break;
797 }
798 if (proglen == oldproglen) {
799 image = module_alloc(proglen);
800 if (!image)
801 goto out;
802 }
803 oldproglen = proglen;
804 }
805
806 if (bpf_jit_enable > 1)
807 bpf_jit_dump(flen, proglen, pass, image);
808
809 if (image) {
810 bpf_flush_icache(image, image + proglen);
811 fp->bpf_func = (void *)image;
812 fp->jited = 1;
813 }
814 out:
815 kfree(addrs);
816 return;
817 }
818
819 void bpf_jit_free(struct sk_filter *fp)
820 {
821 if (fp->jited)
822 module_free(NULL, fp->bpf_func);
823 kfree(fp);
824 }
Linux kernel - Deliverables
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