Commit | Line | Data |
---|---|---|
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 | */ | |
c10302ef | 8 | #include <linux/netdevice.h> |
5303a0fe | 9 | #include <linux/if_vlan.h> |
c10302ef | 10 | #include <linux/filter.h> |
c9a7afa3 | 11 | #include <linux/init.h> |
c10302ef | 12 | #include <asm/cacheflush.h> |
68d9884d | 13 | #include <asm/facility.h> |
0f20822a | 14 | #include <asm/dis.h> |
c10302ef MS |
15 | |
16 | /* | |
17 | * Conventions: | |
18 | * %r2 = skb pointer | |
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 | |
24 | * %r10 = skb->data | |
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 | |
29 | */ | |
30 | int bpf_jit_enable __read_mostly; | |
31 | ||
32 | /* | |
33 | * assembly code in arch/x86/net/bpf_jit.S | |
34 | */ | |
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[]; | |
37 | ||
38 | struct bpf_jit { | |
39 | unsigned int seen; | |
40 | u8 *start; | |
41 | u8 *prg; | |
42 | u8 *mid; | |
43 | u8 *lit; | |
44 | u8 *end; | |
45 | u8 *base_ip; | |
46 | u8 *ret0_ip; | |
47 | u8 *exit_ip; | |
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; | |
55 | }; | |
56 | ||
57 | #define BPF_SIZE_MAX 4096 /* Max size for program */ | |
58 | ||
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 */ | |
71 | ||
72 | #define EMIT2(op) \ | |
73 | ({ \ | |
74 | if (jit->prg + 2 <= jit->mid) \ | |
75 | *(u16 *) jit->prg = op; \ | |
76 | jit->prg += 2; \ | |
77 | }) | |
78 | ||
79 | #define EMIT4(op) \ | |
80 | ({ \ | |
81 | if (jit->prg + 4 <= jit->mid) \ | |
82 | *(u32 *) jit->prg = op; \ | |
83 | jit->prg += 4; \ | |
84 | }) | |
85 | ||
86 | #define EMIT4_DISP(op, disp) \ | |
87 | ({ \ | |
88 | unsigned int __disp = (disp) & 0xfff; \ | |
89 | EMIT4(op | __disp); \ | |
90 | }) | |
91 | ||
92 | #define EMIT4_IMM(op, imm) \ | |
93 | ({ \ | |
94 | unsigned int __imm = (imm) & 0xffff; \ | |
95 | EMIT4(op | __imm); \ | |
96 | }) | |
97 | ||
98 | #define EMIT4_PCREL(op, pcrel) \ | |
99 | ({ \ | |
100 | long __pcrel = ((pcrel) >> 1) & 0xffff; \ | |
101 | EMIT4(op | __pcrel); \ | |
102 | }) | |
103 | ||
104 | #define EMIT6(op1, op2) \ | |
105 | ({ \ | |
106 | if (jit->prg + 6 <= jit->mid) { \ | |
107 | *(u32 *) jit->prg = op1; \ | |
108 | *(u16 *) (jit->prg + 4) = op2; \ | |
109 | } \ | |
110 | jit->prg += 6; \ | |
111 | }) | |
112 | ||
113 | #define EMIT6_DISP(op1, op2, disp) \ | |
114 | ({ \ | |
115 | unsigned int __disp = (disp) & 0xfff; \ | |
116 | EMIT6(op1 | __disp, op2); \ | |
117 | }) | |
118 | ||
68d9884d HC |
119 | #define EMIT6_IMM(op, imm) \ |
120 | ({ \ | |
121 | unsigned int __imm = (imm); \ | |
122 | EMIT6(op | (__imm >> 16), __imm & 0xffff); \ | |
123 | }) | |
124 | ||
c10302ef MS |
125 | #define EMIT_CONST(val) \ |
126 | ({ \ | |
127 | unsigned int ret; \ | |
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; \ | |
132 | jit->lit += 4; \ | |
133 | ret; \ | |
134 | }) | |
135 | ||
136 | #define EMIT_FN_CONST(bit, fn) \ | |
137 | ({ \ | |
138 | unsigned int ret; \ | |
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; \ | |
144 | jit->lit += 8; \ | |
145 | } \ | |
146 | ret; \ | |
147 | }) | |
148 | ||
738cbe72 DB |
149 | static void bpf_jit_fill_hole(void *area, unsigned int size) |
150 | { | |
151 | /* Fill whole space with illegal instructions */ | |
152 | memset(area, 0, size); | |
153 | } | |
154 | ||
c10302ef MS |
155 | static void bpf_jit_prologue(struct bpf_jit *jit) |
156 | { | |
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); | |
161 | /* lgr %r14,%r15 */ | |
162 | EMIT4(0xb90400ef); | |
6cef3003 MS |
163 | /* aghi %r15,<offset> */ |
164 | EMIT4_IMM(0xa7fb0000, (jit->seen & SEEN_MEM) ? -112 : -80); | |
c10302ef MS |
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); | |
176 | ||
177 | /* Setup literal pool */ | |
178 | if (jit->seen & SEEN_LITERAL) { | |
179 | /* basr %r13,0 */ | |
180 | EMIT2(0x0dd0); | |
181 | jit->base_ip = jit->prg; | |
182 | } | |
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); | |
190 | ||
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)); | |
200 | } | |
201 | } | |
202 | ||
203 | static void bpf_jit_epilogue(struct bpf_jit *jit) | |
204 | { | |
205 | /* Return 0 */ | |
206 | if (jit->seen & SEEN_RET0) { | |
207 | jit->ret0_ip = jit->prg; | |
208 | /* lghi %r2,0 */ | |
209 | EMIT4(0xa7290000); | |
210 | } | |
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); | |
226 | /* br %r14 */ | |
227 | EMIT2(0x07fe); | |
228 | } | |
229 | ||
230 | /* | |
231 | * make sure we dont leak kernel information to user | |
232 | */ | |
233 | static void bpf_jit_noleaks(struct bpf_jit *jit, struct sock_filter *filter) | |
234 | { | |
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) | |
241 | /* lhi %r12,0 */ | |
242 | EMIT4(0xa7c80000); | |
243 | /* Clear A if the first register does not set it. */ | |
244 | switch (filter[0].code) { | |
34805931 DB |
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: | |
c10302ef MS |
256 | /* first instruction sets A register */ |
257 | break; | |
258 | default: /* A = 0 */ | |
259 | /* lhi %r5,0 */ | |
260 | EMIT4(0xa7580000); | |
261 | } | |
262 | } | |
263 | ||
264 | static int bpf_jit_insn(struct bpf_jit *jit, struct sock_filter *filter, | |
265 | unsigned int *addrs, int i, int last) | |
266 | { | |
267 | unsigned int K; | |
268 | int offset; | |
269 | unsigned int mask; | |
34805931 | 270 | u16 code; |
c10302ef MS |
271 | |
272 | K = filter->k; | |
34805931 DB |
273 | code = bpf_anc_helper(filter); |
274 | ||
275 | switch (code) { | |
276 | case BPF_ALU | BPF_ADD | BPF_X: /* A += X */ | |
c10302ef MS |
277 | jit->seen |= SEEN_XREG; |
278 | /* ar %r5,%r12 */ | |
279 | EMIT2(0x1a5c); | |
280 | break; | |
34805931 | 281 | case BPF_ALU | BPF_ADD | BPF_K: /* A += K */ |
c10302ef MS |
282 | if (!K) |
283 | break; | |
284 | if (K <= 16383) | |
285 | /* ahi %r5,<K> */ | |
286 | EMIT4_IMM(0xa75a0000, K); | |
68d9884d HC |
287 | else if (test_facility(21)) |
288 | /* alfi %r5,<K> */ | |
289 | EMIT6_IMM(0xc25b0000, K); | |
c10302ef MS |
290 | else |
291 | /* a %r5,<d(K)>(%r13) */ | |
292 | EMIT4_DISP(0x5a50d000, EMIT_CONST(K)); | |
293 | break; | |
34805931 | 294 | case BPF_ALU | BPF_SUB | BPF_X: /* A -= X */ |
c10302ef MS |
295 | jit->seen |= SEEN_XREG; |
296 | /* sr %r5,%r12 */ | |
297 | EMIT2(0x1b5c); | |
298 | break; | |
34805931 | 299 | case BPF_ALU | BPF_SUB | BPF_K: /* A -= K */ |
c10302ef MS |
300 | if (!K) |
301 | break; | |
302 | if (K <= 16384) | |
303 | /* ahi %r5,-K */ | |
304 | EMIT4_IMM(0xa75a0000, -K); | |
68d9884d HC |
305 | else if (test_facility(21)) |
306 | /* alfi %r5,-K */ | |
307 | EMIT6_IMM(0xc25b0000, -K); | |
c10302ef MS |
308 | else |
309 | /* s %r5,<d(K)>(%r13) */ | |
310 | EMIT4_DISP(0x5b50d000, EMIT_CONST(K)); | |
311 | break; | |
34805931 | 312 | case BPF_ALU | BPF_MUL | BPF_X: /* A *= X */ |
c10302ef MS |
313 | jit->seen |= SEEN_XREG; |
314 | /* msr %r5,%r12 */ | |
315 | EMIT4(0xb252005c); | |
316 | break; | |
34805931 | 317 | case BPF_ALU | BPF_MUL | BPF_K: /* A *= K */ |
c10302ef MS |
318 | if (K <= 16383) |
319 | /* mhi %r5,K */ | |
320 | EMIT4_IMM(0xa75c0000, K); | |
68d9884d HC |
321 | else if (test_facility(34)) |
322 | /* msfi %r5,<K> */ | |
323 | EMIT6_IMM(0xc2510000, K); | |
c10302ef MS |
324 | else |
325 | /* ms %r5,<d(K)>(%r13) */ | |
326 | EMIT4_DISP(0x7150d000, EMIT_CONST(K)); | |
327 | break; | |
34805931 | 328 | case BPF_ALU | BPF_DIV | BPF_X: /* A /= X */ |
c10302ef MS |
329 | jit->seen |= SEEN_XREG | SEEN_RET0; |
330 | /* ltr %r12,%r12 */ | |
331 | EMIT2(0x12cc); | |
332 | /* jz <ret0> */ | |
333 | EMIT4_PCREL(0xa7840000, (jit->ret0_ip - jit->prg)); | |
334 | /* lhi %r4,0 */ | |
335 | EMIT4(0xa7480000); | |
3af57f78 HC |
336 | /* dlr %r4,%r12 */ |
337 | EMIT4(0xb997004c); | |
c10302ef | 338 | break; |
34805931 | 339 | case BPF_ALU | BPF_DIV | BPF_K: /* A /= K */ |
aee636c4 ED |
340 | if (K == 1) |
341 | break; | |
342 | /* lhi %r4,0 */ | |
343 | EMIT4(0xa7480000); | |
3af57f78 HC |
344 | /* dl %r4,<d(K)>(%r13) */ |
345 | EMIT6_DISP(0xe340d000, 0x0097, EMIT_CONST(K)); | |
32472745 | 346 | break; |
34805931 | 347 | case BPF_ALU | BPF_MOD | BPF_X: /* A %= X */ |
32472745 HC |
348 | jit->seen |= SEEN_XREG | SEEN_RET0; |
349 | /* ltr %r12,%r12 */ | |
350 | EMIT2(0x12cc); | |
351 | /* jz <ret0> */ | |
352 | EMIT4_PCREL(0xa7840000, (jit->ret0_ip - jit->prg)); | |
353 | /* lhi %r4,0 */ | |
354 | EMIT4(0xa7480000); | |
3af57f78 HC |
355 | /* dlr %r4,%r12 */ |
356 | EMIT4(0xb997004c); | |
32472745 HC |
357 | /* lr %r5,%r4 */ |
358 | EMIT2(0x1854); | |
359 | break; | |
34805931 | 360 | case BPF_ALU | BPF_MOD | BPF_K: /* A %= K */ |
aee636c4 ED |
361 | if (K == 1) { |
362 | /* lhi %r5,0 */ | |
363 | EMIT4(0xa7580000); | |
364 | break; | |
365 | } | |
32472745 HC |
366 | /* lhi %r4,0 */ |
367 | EMIT4(0xa7480000); | |
3af57f78 HC |
368 | /* dl %r4,<d(K)>(%r13) */ |
369 | EMIT6_DISP(0xe340d000, 0x0097, EMIT_CONST(K)); | |
c10302ef MS |
370 | /* lr %r5,%r4 */ |
371 | EMIT2(0x1854); | |
372 | break; | |
34805931 | 373 | case BPF_ALU | BPF_AND | BPF_X: /* A &= X */ |
c10302ef MS |
374 | jit->seen |= SEEN_XREG; |
375 | /* nr %r5,%r12 */ | |
376 | EMIT2(0x145c); | |
377 | break; | |
34805931 | 378 | case BPF_ALU | BPF_AND | BPF_K: /* A &= K */ |
68d9884d HC |
379 | if (test_facility(21)) |
380 | /* nilf %r5,<K> */ | |
381 | EMIT6_IMM(0xc05b0000, K); | |
382 | else | |
383 | /* n %r5,<d(K)>(%r13) */ | |
384 | EMIT4_DISP(0x5450d000, EMIT_CONST(K)); | |
c10302ef | 385 | break; |
34805931 | 386 | case BPF_ALU | BPF_OR | BPF_X: /* A |= X */ |
c10302ef MS |
387 | jit->seen |= SEEN_XREG; |
388 | /* or %r5,%r12 */ | |
389 | EMIT2(0x165c); | |
390 | break; | |
34805931 | 391 | case BPF_ALU | BPF_OR | BPF_K: /* A |= K */ |
68d9884d HC |
392 | if (test_facility(21)) |
393 | /* oilf %r5,<K> */ | |
394 | EMIT6_IMM(0xc05d0000, K); | |
395 | else | |
396 | /* o %r5,<d(K)>(%r13) */ | |
397 | EMIT4_DISP(0x5650d000, EMIT_CONST(K)); | |
c10302ef | 398 | break; |
34805931 DB |
399 | case BPF_ANC | SKF_AD_ALU_XOR_X: /* A ^= X; */ |
400 | case BPF_ALU | BPF_XOR | BPF_X: | |
c59eed11 HC |
401 | jit->seen |= SEEN_XREG; |
402 | /* xr %r5,%r12 */ | |
403 | EMIT2(0x175c); | |
404 | break; | |
34805931 | 405 | case BPF_ALU | BPF_XOR | BPF_K: /* A ^= K */ |
916908df HC |
406 | if (!K) |
407 | break; | |
408 | /* x %r5,<d(K)>(%r13) */ | |
409 | EMIT4_DISP(0x5750d000, EMIT_CONST(K)); | |
410 | break; | |
34805931 | 411 | case BPF_ALU | BPF_LSH | BPF_X: /* A <<= X; */ |
c10302ef MS |
412 | jit->seen |= SEEN_XREG; |
413 | /* sll %r5,0(%r12) */ | |
414 | EMIT4(0x8950c000); | |
415 | break; | |
34805931 | 416 | case BPF_ALU | BPF_LSH | BPF_K: /* A <<= K */ |
c10302ef MS |
417 | if (K == 0) |
418 | break; | |
419 | /* sll %r5,K */ | |
420 | EMIT4_DISP(0x89500000, K); | |
421 | break; | |
34805931 | 422 | case BPF_ALU | BPF_RSH | BPF_X: /* A >>= X; */ |
c10302ef MS |
423 | jit->seen |= SEEN_XREG; |
424 | /* srl %r5,0(%r12) */ | |
425 | EMIT4(0x8850c000); | |
426 | break; | |
34805931 | 427 | case BPF_ALU | BPF_RSH | BPF_K: /* A >>= K; */ |
c10302ef MS |
428 | if (K == 0) |
429 | break; | |
430 | /* srl %r5,K */ | |
431 | EMIT4_DISP(0x88500000, K); | |
432 | break; | |
34805931 | 433 | case BPF_ALU | BPF_NEG: /* A = -A */ |
df3eed3d MH |
434 | /* lcr %r5,%r5 */ |
435 | EMIT2(0x1355); | |
c10302ef | 436 | break; |
34805931 | 437 | case BPF_JMP | BPF_JA: /* ip += K */ |
c10302ef MS |
438 | offset = addrs[i + K] + jit->start - jit->prg; |
439 | EMIT4_PCREL(0xa7f40000, offset); | |
440 | break; | |
34805931 | 441 | case BPF_JMP | BPF_JGT | BPF_K: /* ip += (A > K) ? jt : jf */ |
c10302ef MS |
442 | mask = 0x200000; /* jh */ |
443 | goto kbranch; | |
34805931 | 444 | case BPF_JMP | BPF_JGE | BPF_K: /* ip += (A >= K) ? jt : jf */ |
c10302ef MS |
445 | mask = 0xa00000; /* jhe */ |
446 | goto kbranch; | |
34805931 | 447 | case BPF_JMP | BPF_JEQ | BPF_K: /* ip += (A == K) ? jt : jf */ |
c10302ef MS |
448 | mask = 0x800000; /* je */ |
449 | kbranch: /* Emit compare if the branch targets are different */ | |
450 | if (filter->jt != filter->jf) { | |
5a802442 | 451 | if (test_facility(21)) |
68d9884d HC |
452 | /* clfi %r5,<K> */ |
453 | EMIT6_IMM(0xc25f0000, K); | |
c10302ef | 454 | else |
5a802442 MH |
455 | /* cl %r5,<d(K)>(%r13) */ |
456 | EMIT4_DISP(0x5550d000, EMIT_CONST(K)); | |
c10302ef MS |
457 | } |
458 | branch: if (filter->jt == filter->jf) { | |
459 | if (filter->jt == 0) | |
460 | break; | |
461 | /* j <jt> */ | |
462 | offset = addrs[i + filter->jt] + jit->start - jit->prg; | |
463 | EMIT4_PCREL(0xa7f40000, offset); | |
464 | break; | |
465 | } | |
466 | if (filter->jt != 0) { | |
467 | /* brc <mask>,<jt> */ | |
468 | offset = addrs[i + filter->jt] + jit->start - jit->prg; | |
469 | EMIT4_PCREL(0xa7040000 | mask, offset); | |
470 | } | |
471 | if (filter->jf != 0) { | |
472 | /* brc <mask^15>,<jf> */ | |
473 | offset = addrs[i + filter->jf] + jit->start - jit->prg; | |
474 | EMIT4_PCREL(0xa7040000 | (mask ^ 0xf00000), offset); | |
475 | } | |
476 | break; | |
34805931 | 477 | case BPF_JMP | BPF_JSET | BPF_K: /* ip += (A & K) ? jt : jf */ |
c10302ef MS |
478 | mask = 0x700000; /* jnz */ |
479 | /* Emit test if the branch targets are different */ | |
480 | if (filter->jt != filter->jf) { | |
481 | if (K > 65535) { | |
482 | /* lr %r4,%r5 */ | |
483 | EMIT2(0x1845); | |
484 | /* n %r4,<d(K)>(%r13) */ | |
485 | EMIT4_DISP(0x5440d000, EMIT_CONST(K)); | |
486 | } else | |
487 | /* tmll %r5,K */ | |
488 | EMIT4_IMM(0xa7510000, K); | |
489 | } | |
490 | goto branch; | |
34805931 | 491 | case BPF_JMP | BPF_JGT | BPF_X: /* ip += (A > X) ? jt : jf */ |
c10302ef MS |
492 | mask = 0x200000; /* jh */ |
493 | goto xbranch; | |
34805931 | 494 | case BPF_JMP | BPF_JGE | BPF_X: /* ip += (A >= X) ? jt : jf */ |
c10302ef MS |
495 | mask = 0xa00000; /* jhe */ |
496 | goto xbranch; | |
34805931 | 497 | case BPF_JMP | BPF_JEQ | BPF_X: /* ip += (A == X) ? jt : jf */ |
c10302ef MS |
498 | mask = 0x800000; /* je */ |
499 | xbranch: /* Emit compare if the branch targets are different */ | |
500 | if (filter->jt != filter->jf) { | |
501 | jit->seen |= SEEN_XREG; | |
ae750974 MH |
502 | /* clr %r5,%r12 */ |
503 | EMIT2(0x155c); | |
c10302ef MS |
504 | } |
505 | goto branch; | |
34805931 | 506 | case BPF_JMP | BPF_JSET | BPF_X: /* ip += (A & X) ? jt : jf */ |
c10302ef MS |
507 | mask = 0x700000; /* jnz */ |
508 | /* Emit test if the branch targets are different */ | |
509 | if (filter->jt != filter->jf) { | |
510 | jit->seen |= SEEN_XREG; | |
511 | /* lr %r4,%r5 */ | |
512 | EMIT2(0x1845); | |
513 | /* nr %r4,%r12 */ | |
514 | EMIT2(0x144c); | |
515 | } | |
516 | goto branch; | |
34805931 | 517 | case BPF_LD | BPF_W | BPF_ABS: /* A = *(u32 *) (skb->data+K) */ |
c10302ef MS |
518 | jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_WORD; |
519 | offset = jit->off_load_word; | |
520 | goto load_abs; | |
34805931 | 521 | case BPF_LD | BPF_H | BPF_ABS: /* A = *(u16 *) (skb->data+K) */ |
c10302ef MS |
522 | jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_HALF; |
523 | offset = jit->off_load_half; | |
524 | goto load_abs; | |
34805931 | 525 | case BPF_LD | BPF_B | BPF_ABS: /* A = *(u8 *) (skb->data+K) */ |
c10302ef MS |
526 | jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_BYTE; |
527 | offset = jit->off_load_byte; | |
528 | load_abs: if ((int) K < 0) | |
529 | goto out; | |
530 | call_fn: /* lg %r1,<d(function)>(%r13) */ | |
531 | EMIT6_DISP(0xe310d000, 0x0004, offset); | |
532 | /* l %r3,<d(K)>(%r13) */ | |
533 | EMIT4_DISP(0x5830d000, EMIT_CONST(K)); | |
534 | /* basr %r8,%r1 */ | |
535 | EMIT2(0x0d81); | |
536 | /* jnz <ret0> */ | |
537 | EMIT4_PCREL(0xa7740000, (jit->ret0_ip - jit->prg)); | |
538 | break; | |
34805931 | 539 | case BPF_LD | BPF_W | BPF_IND: /* A = *(u32 *) (skb->data+K+X) */ |
c10302ef MS |
540 | jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IWORD; |
541 | offset = jit->off_load_iword; | |
542 | goto call_fn; | |
34805931 | 543 | case BPF_LD | BPF_H | BPF_IND: /* A = *(u16 *) (skb->data+K+X) */ |
c10302ef MS |
544 | jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IHALF; |
545 | offset = jit->off_load_ihalf; | |
546 | goto call_fn; | |
34805931 | 547 | case BPF_LD | BPF_B | BPF_IND: /* A = *(u8 *) (skb->data+K+X) */ |
c10302ef MS |
548 | jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IBYTE; |
549 | offset = jit->off_load_ibyte; | |
550 | goto call_fn; | |
34805931 | 551 | case BPF_LDX | BPF_B | BPF_MSH: |
c10302ef MS |
552 | /* X = (*(u8 *)(skb->data+K) & 0xf) << 2 */ |
553 | jit->seen |= SEEN_RET0; | |
554 | if ((int) K < 0) { | |
555 | /* j <ret0> */ | |
556 | EMIT4_PCREL(0xa7f40000, (jit->ret0_ip - jit->prg)); | |
557 | break; | |
558 | } | |
559 | jit->seen |= SEEN_DATAREF | SEEN_LOAD_BMSH; | |
560 | offset = jit->off_load_bmsh; | |
561 | goto call_fn; | |
34805931 | 562 | case BPF_LD | BPF_W | BPF_LEN: /* A = skb->len; */ |
c10302ef MS |
563 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4); |
564 | /* l %r5,<d(len)>(%r2) */ | |
565 | EMIT4_DISP(0x58502000, offsetof(struct sk_buff, len)); | |
566 | break; | |
34805931 | 567 | case BPF_LDX | BPF_W | BPF_LEN: /* X = skb->len; */ |
c10302ef MS |
568 | jit->seen |= SEEN_XREG; |
569 | /* l %r12,<d(len)>(%r2) */ | |
570 | EMIT4_DISP(0x58c02000, offsetof(struct sk_buff, len)); | |
571 | break; | |
34805931 | 572 | case BPF_LD | BPF_IMM: /* A = K */ |
c10302ef MS |
573 | if (K <= 16383) |
574 | /* lhi %r5,K */ | |
575 | EMIT4_IMM(0xa7580000, K); | |
68d9884d HC |
576 | else if (test_facility(21)) |
577 | /* llilf %r5,<K> */ | |
578 | EMIT6_IMM(0xc05f0000, K); | |
c10302ef MS |
579 | else |
580 | /* l %r5,<d(K)>(%r13) */ | |
581 | EMIT4_DISP(0x5850d000, EMIT_CONST(K)); | |
582 | break; | |
34805931 | 583 | case BPF_LDX | BPF_IMM: /* X = K */ |
c10302ef MS |
584 | jit->seen |= SEEN_XREG; |
585 | if (K <= 16383) | |
586 | /* lhi %r12,<K> */ | |
587 | EMIT4_IMM(0xa7c80000, K); | |
68d9884d HC |
588 | else if (test_facility(21)) |
589 | /* llilf %r12,<K> */ | |
590 | EMIT6_IMM(0xc0cf0000, K); | |
c10302ef MS |
591 | else |
592 | /* l %r12,<d(K)>(%r13) */ | |
593 | EMIT4_DISP(0x58c0d000, EMIT_CONST(K)); | |
594 | break; | |
34805931 | 595 | case BPF_LD | BPF_MEM: /* A = mem[K] */ |
c10302ef MS |
596 | jit->seen |= SEEN_MEM; |
597 | /* l %r5,<K>(%r15) */ | |
598 | EMIT4_DISP(0x5850f000, | |
599 | (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4); | |
600 | break; | |
34805931 | 601 | case BPF_LDX | BPF_MEM: /* X = mem[K] */ |
c10302ef MS |
602 | jit->seen |= SEEN_XREG | SEEN_MEM; |
603 | /* l %r12,<K>(%r15) */ | |
604 | EMIT4_DISP(0x58c0f000, | |
605 | (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4); | |
606 | break; | |
34805931 | 607 | case BPF_MISC | BPF_TAX: /* X = A */ |
c10302ef MS |
608 | jit->seen |= SEEN_XREG; |
609 | /* lr %r12,%r5 */ | |
610 | EMIT2(0x18c5); | |
611 | break; | |
34805931 | 612 | case BPF_MISC | BPF_TXA: /* A = X */ |
c10302ef MS |
613 | jit->seen |= SEEN_XREG; |
614 | /* lr %r5,%r12 */ | |
615 | EMIT2(0x185c); | |
616 | break; | |
34805931 | 617 | case BPF_RET | BPF_K: |
c10302ef MS |
618 | if (K == 0) { |
619 | jit->seen |= SEEN_RET0; | |
620 | if (last) | |
621 | break; | |
622 | /* j <ret0> */ | |
623 | EMIT4_PCREL(0xa7f40000, jit->ret0_ip - jit->prg); | |
624 | } else { | |
625 | if (K <= 16383) | |
626 | /* lghi %r2,K */ | |
627 | EMIT4_IMM(0xa7290000, K); | |
628 | else | |
629 | /* llgf %r2,<K>(%r13) */ | |
630 | EMIT6_DISP(0xe320d000, 0x0016, EMIT_CONST(K)); | |
631 | /* j <exit> */ | |
632 | if (last && !(jit->seen & SEEN_RET0)) | |
633 | break; | |
634 | EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg); | |
635 | } | |
636 | break; | |
34805931 | 637 | case BPF_RET | BPF_A: |
c10302ef MS |
638 | /* llgfr %r2,%r5 */ |
639 | EMIT4(0xb9160025); | |
640 | /* j <exit> */ | |
641 | EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg); | |
642 | break; | |
34805931 | 643 | case BPF_ST: /* mem[K] = A */ |
c10302ef MS |
644 | jit->seen |= SEEN_MEM; |
645 | /* st %r5,<K>(%r15) */ | |
646 | EMIT4_DISP(0x5050f000, | |
647 | (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4); | |
648 | break; | |
34805931 | 649 | case BPF_STX: /* mem[K] = X : mov %ebx,off8(%rbp) */ |
c10302ef MS |
650 | jit->seen |= SEEN_XREG | SEEN_MEM; |
651 | /* st %r12,<K>(%r15) */ | |
652 | EMIT4_DISP(0x50c0f000, | |
653 | (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4); | |
654 | break; | |
34805931 | 655 | case BPF_ANC | SKF_AD_PROTOCOL: /* A = ntohs(skb->protocol); */ |
c10302ef MS |
656 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2); |
657 | /* lhi %r5,0 */ | |
658 | EMIT4(0xa7580000); | |
659 | /* icm %r5,3,<d(protocol)>(%r2) */ | |
660 | EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, protocol)); | |
661 | break; | |
34805931 DB |
662 | case BPF_ANC | SKF_AD_IFINDEX: /* if (!skb->dev) return 0; |
663 | * A = skb->dev->ifindex */ | |
c10302ef MS |
664 | BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); |
665 | jit->seen |= SEEN_RET0; | |
666 | /* lg %r1,<d(dev)>(%r2) */ | |
667 | EMIT6_DISP(0xe3102000, 0x0004, offsetof(struct sk_buff, dev)); | |
668 | /* ltgr %r1,%r1 */ | |
669 | EMIT4(0xb9020011); | |
670 | /* jz <ret0> */ | |
671 | EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg); | |
672 | /* l %r5,<d(ifindex)>(%r1) */ | |
673 | EMIT4_DISP(0x58501000, offsetof(struct net_device, ifindex)); | |
674 | break; | |
34805931 | 675 | case BPF_ANC | SKF_AD_MARK: /* A = skb->mark */ |
c10302ef MS |
676 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4); |
677 | /* l %r5,<d(mark)>(%r2) */ | |
678 | EMIT4_DISP(0x58502000, offsetof(struct sk_buff, mark)); | |
679 | break; | |
34805931 | 680 | case BPF_ANC | SKF_AD_QUEUE: /* A = skb->queue_mapping */ |
c10302ef MS |
681 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2); |
682 | /* lhi %r5,0 */ | |
683 | EMIT4(0xa7580000); | |
684 | /* icm %r5,3,<d(queue_mapping)>(%r2) */ | |
685 | EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, queue_mapping)); | |
686 | break; | |
34805931 DB |
687 | case BPF_ANC | SKF_AD_HATYPE: /* if (!skb->dev) return 0; |
688 | * A = skb->dev->type */ | |
c10302ef MS |
689 | BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2); |
690 | jit->seen |= SEEN_RET0; | |
691 | /* lg %r1,<d(dev)>(%r2) */ | |
692 | EMIT6_DISP(0xe3102000, 0x0004, offsetof(struct sk_buff, dev)); | |
693 | /* ltgr %r1,%r1 */ | |
694 | EMIT4(0xb9020011); | |
695 | /* jz <ret0> */ | |
696 | EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg); | |
697 | /* lhi %r5,0 */ | |
698 | EMIT4(0xa7580000); | |
699 | /* icm %r5,3,<d(type)>(%r1) */ | |
700 | EMIT4_DISP(0xbf531000, offsetof(struct net_device, type)); | |
701 | break; | |
34805931 | 702 | case BPF_ANC | SKF_AD_RXHASH: /* A = skb->hash */ |
61b905da TH |
703 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4); |
704 | /* l %r5,<d(hash)>(%r2) */ | |
705 | EMIT4_DISP(0x58502000, offsetof(struct sk_buff, hash)); | |
c10302ef | 706 | break; |
34805931 DB |
707 | case BPF_ANC | SKF_AD_VLAN_TAG: |
708 | case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT: | |
5303a0fe HC |
709 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2); |
710 | BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000); | |
711 | /* lhi %r5,0 */ | |
712 | EMIT4(0xa7580000); | |
713 | /* icm %r5,3,<d(vlan_tci)>(%r2) */ | |
714 | EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, vlan_tci)); | |
34805931 | 715 | if (code == (BPF_ANC | SKF_AD_VLAN_TAG)) { |
5303a0fe HC |
716 | /* nill %r5,0xefff */ |
717 | EMIT4_IMM(0xa5570000, ~VLAN_TAG_PRESENT); | |
718 | } else { | |
719 | /* nill %r5,0x1000 */ | |
720 | EMIT4_IMM(0xa5570000, VLAN_TAG_PRESENT); | |
721 | /* srl %r5,12 */ | |
722 | EMIT4_DISP(0x88500000, 12); | |
723 | } | |
724 | break; | |
34805931 | 725 | case BPF_ANC | SKF_AD_PKTTYPE: |
c9a7afa3 HC |
726 | /* lhi %r5,0 */ |
727 | EMIT4(0xa7580000); | |
728 | /* ic %r5,<d(pkt_type_offset)>(%r2) */ | |
233577a2 | 729 | EMIT4_DISP(0x43502000, PKT_TYPE_OFFSET()); |
c9a7afa3 HC |
730 | /* srl %r5,5 */ |
731 | EMIT4_DISP(0x88500000, 5); | |
732 | break; | |
34805931 | 733 | case BPF_ANC | SKF_AD_CPU: /* A = smp_processor_id() */ |
c10302ef MS |
734 | #ifdef CONFIG_SMP |
735 | /* l %r5,<d(cpu_nr)> */ | |
736 | EMIT4_DISP(0x58500000, offsetof(struct _lowcore, cpu_nr)); | |
737 | #else | |
738 | /* lhi %r5,0 */ | |
739 | EMIT4(0xa7580000); | |
740 | #endif | |
741 | break; | |
742 | default: /* too complex, give up */ | |
743 | goto out; | |
744 | } | |
745 | addrs[i] = jit->prg - jit->start; | |
746 | return 0; | |
747 | out: | |
748 | return -1; | |
749 | } | |
750 | ||
7ae457c1 | 751 | void bpf_jit_compile(struct bpf_prog *fp) |
c10302ef | 752 | { |
aa2d2c73 | 753 | struct bpf_binary_header *header = NULL; |
c10302ef MS |
754 | unsigned long size, prg_len, lit_len; |
755 | struct bpf_jit jit, cjit; | |
756 | unsigned int *addrs; | |
757 | int pass, i; | |
758 | ||
759 | if (!bpf_jit_enable) | |
760 | return; | |
3d04fea5 | 761 | addrs = kcalloc(fp->len, sizeof(*addrs), GFP_KERNEL); |
c10302ef MS |
762 | if (addrs == NULL) |
763 | return; | |
c10302ef MS |
764 | memset(&jit, 0, sizeof(cjit)); |
765 | memset(&cjit, 0, sizeof(cjit)); | |
766 | ||
767 | for (pass = 0; pass < 10; pass++) { | |
768 | jit.prg = jit.start; | |
769 | jit.lit = jit.mid; | |
770 | ||
771 | bpf_jit_prologue(&jit); | |
772 | bpf_jit_noleaks(&jit, fp->insns); | |
773 | for (i = 0; i < fp->len; i++) { | |
774 | if (bpf_jit_insn(&jit, fp->insns + i, addrs, i, | |
775 | i == fp->len - 1)) | |
776 | goto out; | |
777 | } | |
778 | bpf_jit_epilogue(&jit); | |
779 | if (jit.start) { | |
780 | WARN_ON(jit.prg > cjit.prg || jit.lit > cjit.lit); | |
781 | if (memcmp(&jit, &cjit, sizeof(jit)) == 0) | |
782 | break; | |
783 | } else if (jit.prg == cjit.prg && jit.lit == cjit.lit) { | |
784 | prg_len = jit.prg - jit.start; | |
785 | lit_len = jit.lit - jit.mid; | |
1eeb7478 | 786 | size = prg_len + lit_len; |
c10302ef MS |
787 | if (size >= BPF_SIZE_MAX) |
788 | goto out; | |
738cbe72 DB |
789 | header = bpf_jit_binary_alloc(size, &jit.start, |
790 | 2, bpf_jit_fill_hole); | |
aa2d2c73 | 791 | if (!header) |
c10302ef MS |
792 | goto out; |
793 | jit.prg = jit.mid = jit.start + prg_len; | |
794 | jit.lit = jit.end = jit.start + prg_len + lit_len; | |
795 | jit.base_ip += (unsigned long) jit.start; | |
796 | jit.exit_ip += (unsigned long) jit.start; | |
797 | jit.ret0_ip += (unsigned long) jit.start; | |
798 | } | |
799 | cjit = jit; | |
800 | } | |
801 | if (bpf_jit_enable > 1) { | |
fee1b548 HC |
802 | bpf_jit_dump(fp->len, jit.end - jit.start, pass, jit.start); |
803 | if (jit.start) | |
c10302ef | 804 | print_fn_code(jit.start, jit.mid - jit.start); |
c10302ef | 805 | } |
aa2d2c73 HC |
806 | if (jit.start) { |
807 | set_memory_ro((unsigned long)header, header->pages); | |
c10302ef | 808 | fp->bpf_func = (void *) jit.start; |
286aad3c | 809 | fp->jited = true; |
aa2d2c73 | 810 | } |
c10302ef MS |
811 | out: |
812 | kfree(addrs); | |
813 | } | |
814 | ||
7ae457c1 | 815 | void bpf_jit_free(struct bpf_prog *fp) |
c10302ef | 816 | { |
aa2d2c73 HC |
817 | unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK; |
818 | struct bpf_binary_header *header = (void *)addr; | |
819 | ||
f8bbbfc3 | 820 | if (!fp->jited) |
d45ed4a4 | 821 | goto free_filter; |
f8bbbfc3 | 822 | |
aa2d2c73 | 823 | set_memory_rw(addr, header->pages); |
738cbe72 | 824 | bpf_jit_binary_free(header); |
f8bbbfc3 | 825 | |
d45ed4a4 | 826 | free_filter: |
60a3b225 | 827 | bpf_prog_unlock_free(fp); |
c10302ef | 828 | } |