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Linux 4.17.15
[linux/fpc-iii.git] / arch / s390 / net / bpf_jit_comp.c
blobdd2bcf0e7d00d45406c83e1254879e4f16db36fb
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * BPF Jit compiler for s390.
4 *
5 * Minimum build requirements:
6 *
7 * - HAVE_MARCH_Z196_FEATURES: laal, laalg
8 * - HAVE_MARCH_Z10_FEATURES: msfi, cgrj, clgrj
9 * - HAVE_MARCH_Z9_109_FEATURES: alfi, llilf, clfi, oilf, nilf
10 * - PACK_STACK
11 * - 64BIT
12 *
13 * Copyright IBM Corp. 2012,2015
14 *
15 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
16 * Michael Holzheu <holzheu@linux.vnet.ibm.com>
17 */
18
19 #define KMSG_COMPONENT "bpf_jit"
20 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
21
22 #include <linux/netdevice.h>
23 #include <linux/filter.h>
24 #include <linux/init.h>
25 #include <linux/bpf.h>
26 #include <asm/cacheflush.h>
27 #include <asm/dis.h>
28 #include <asm/facility.h>
29 #include <asm/nospec-branch.h>
30 #include <asm/set_memory.h>
31 #include "bpf_jit.h"
32
33 struct bpf_jit {
34 u32 seen; /* Flags to remember seen eBPF instructions */
35 u32 seen_reg[16]; /* Array to remember which registers are used */
36 u32 *addrs; /* Array with relative instruction addresses */
37 u8 *prg_buf; /* Start of program */
38 int size; /* Size of program and literal pool */
39 int size_prg; /* Size of program */
40 int prg; /* Current position in program */
41 int lit_start; /* Start of literal pool */
42 int lit; /* Current position in literal pool */
43 int base_ip; /* Base address for literal pool */
44 int ret0_ip; /* Address of return 0 */
45 int exit_ip; /* Address of exit */
46 int r1_thunk_ip; /* Address of expoline thunk for 'br %r1' */
47 int r14_thunk_ip; /* Address of expoline thunk for 'br %r14' */
48 int tail_call_start; /* Tail call start offset */
49 int labels[1]; /* Labels for local jumps */
50 };
51
52 #define BPF_SIZE_MAX 0xffff /* Max size for program (16 bit branches) */
53
54 #define SEEN_SKB 1 /* skb access */
55 #define SEEN_MEM 2 /* use mem[] for temporary storage */
56 #define SEEN_RET0 4 /* ret0_ip points to a valid return 0 */
57 #define SEEN_LITERAL 8 /* code uses literals */
58 #define SEEN_FUNC 16 /* calls C functions */
59 #define SEEN_TAIL_CALL 32 /* code uses tail calls */
60 #define SEEN_REG_AX 64 /* code uses constant blinding */
61 #define SEEN_STACK (SEEN_FUNC | SEEN_MEM | SEEN_SKB)
62
63 /*
64 * s390 registers
65 */
66 #define REG_W0 (MAX_BPF_JIT_REG + 0) /* Work register 1 (even) */
67 #define REG_W1 (MAX_BPF_JIT_REG + 1) /* Work register 2 (odd) */
68 #define REG_SKB_DATA (MAX_BPF_JIT_REG + 2) /* SKB data register */
69 #define REG_L (MAX_BPF_JIT_REG + 3) /* Literal pool register */
70 #define REG_15 (MAX_BPF_JIT_REG + 4) /* Register 15 */
71 #define REG_0 REG_W0 /* Register 0 */
72 #define REG_1 REG_W1 /* Register 1 */
73 #define REG_2 BPF_REG_1 /* Register 2 */
74 #define REG_14 BPF_REG_0 /* Register 14 */
75
76 /*
77 * Mapping of BPF registers to s390 registers
78 */
79 static const int reg2hex[] = {
80 /* Return code */
81 [BPF_REG_0] = 14,
82 /* Function parameters */
83 [BPF_REG_1] = 2,
84 [BPF_REG_2] = 3,
85 [BPF_REG_3] = 4,
86 [BPF_REG_4] = 5,
87 [BPF_REG_5] = 6,
88 /* Call saved registers */
89 [BPF_REG_6] = 7,
90 [BPF_REG_7] = 8,
91 [BPF_REG_8] = 9,
92 [BPF_REG_9] = 10,
93 /* BPF stack pointer */
94 [BPF_REG_FP] = 13,
95 /* Register for blinding (shared with REG_SKB_DATA) */
96 [BPF_REG_AX] = 12,
97 /* SKB data pointer */
98 [REG_SKB_DATA] = 12,
99 /* Work registers for s390x backend */
100 [REG_W0] = 0,
101 [REG_W1] = 1,
102 [REG_L] = 11,
103 [REG_15] = 15,
104 };
105
106 static inline u32 reg(u32 dst_reg, u32 src_reg)
107 {
108 return reg2hex[dst_reg] << 4 | reg2hex[src_reg];
109 }
110
111 static inline u32 reg_high(u32 reg)
112 {
113 return reg2hex[reg] << 4;
114 }
115
116 static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
117 {
118 u32 r1 = reg2hex[b1];
119
120 if (!jit->seen_reg[r1] && r1 >= 6 && r1 <= 15)
121 jit->seen_reg[r1] = 1;
122 }
123
124 #define REG_SET_SEEN(b1) \
125 ({ \
126 reg_set_seen(jit, b1); \
127 })
128
129 #define REG_SEEN(b1) jit->seen_reg[reg2hex[(b1)]]
130
131 /*
132 * EMIT macros for code generation
133 */
134
135 #define _EMIT2(op) \
136 ({ \
137 if (jit->prg_buf) \
138 *(u16 *) (jit->prg_buf + jit->prg) = op; \
139 jit->prg += 2; \
140 })
141
142 #define EMIT2(op, b1, b2) \
143 ({ \
144 _EMIT2(op | reg(b1, b2)); \
145 REG_SET_SEEN(b1); \
146 REG_SET_SEEN(b2); \
147 })
148
149 #define _EMIT4(op) \
150 ({ \
151 if (jit->prg_buf) \
152 *(u32 *) (jit->prg_buf + jit->prg) = op; \
153 jit->prg += 4; \
154 })
155
156 #define EMIT4(op, b1, b2) \
157 ({ \
158 _EMIT4(op | reg(b1, b2)); \
159 REG_SET_SEEN(b1); \
160 REG_SET_SEEN(b2); \
161 })
162
163 #define EMIT4_RRF(op, b1, b2, b3) \
164 ({ \
165 _EMIT4(op | reg_high(b3) << 8 | reg(b1, b2)); \
166 REG_SET_SEEN(b1); \
167 REG_SET_SEEN(b2); \
168 REG_SET_SEEN(b3); \
169 })
170
171 #define _EMIT4_DISP(op, disp) \
172 ({ \
173 unsigned int __disp = (disp) & 0xfff; \
174 _EMIT4(op | __disp); \
175 })
176
177 #define EMIT4_DISP(op, b1, b2, disp) \
178 ({ \
179 _EMIT4_DISP(op | reg_high(b1) << 16 | \
180 reg_high(b2) << 8, disp); \
181 REG_SET_SEEN(b1); \
182 REG_SET_SEEN(b2); \
183 })
184
185 #define EMIT4_IMM(op, b1, imm) \
186 ({ \
187 unsigned int __imm = (imm) & 0xffff; \
188 _EMIT4(op | reg_high(b1) << 16 | __imm); \
189 REG_SET_SEEN(b1); \
190 })
191
192 #define EMIT4_PCREL(op, pcrel) \
193 ({ \
194 long __pcrel = ((pcrel) >> 1) & 0xffff; \
195 _EMIT4(op | __pcrel); \
196 })
197
198 #define _EMIT6(op1, op2) \
199 ({ \
200 if (jit->prg_buf) { \
201 *(u32 *) (jit->prg_buf + jit->prg) = op1; \
202 *(u16 *) (jit->prg_buf + jit->prg + 4) = op2; \
203 } \
204 jit->prg += 6; \
205 })
206
207 #define _EMIT6_DISP(op1, op2, disp) \
208 ({ \
209 unsigned int __disp = (disp) & 0xfff; \
210 _EMIT6(op1 | __disp, op2); \
211 })
212
213 #define _EMIT6_DISP_LH(op1, op2, disp) \
214 ({ \
215 u32 _disp = (u32) disp; \
216 unsigned int __disp_h = _disp & 0xff000; \
217 unsigned int __disp_l = _disp & 0x00fff; \
218 _EMIT6(op1 | __disp_l, op2 | __disp_h >> 4); \
219 })
220
221 #define EMIT6_DISP_LH(op1, op2, b1, b2, b3, disp) \
222 ({ \
223 _EMIT6_DISP_LH(op1 | reg(b1, b2) << 16 | \
224 reg_high(b3) << 8, op2, disp); \
225 REG_SET_SEEN(b1); \
226 REG_SET_SEEN(b2); \
227 REG_SET_SEEN(b3); \
228 })
229
230 #define EMIT6_PCREL_LABEL(op1, op2, b1, b2, label, mask) \
231 ({ \
232 int rel = (jit->labels[label] - jit->prg) >> 1; \
233 _EMIT6(op1 | reg(b1, b2) << 16 | (rel & 0xffff), \
234 op2 | mask << 12); \
235 REG_SET_SEEN(b1); \
236 REG_SET_SEEN(b2); \
237 })
238
239 #define EMIT6_PCREL_IMM_LABEL(op1, op2, b1, imm, label, mask) \
240 ({ \
241 int rel = (jit->labels[label] - jit->prg) >> 1; \
242 _EMIT6(op1 | (reg_high(b1) | mask) << 16 | \
243 (rel & 0xffff), op2 | (imm & 0xff) << 8); \
244 REG_SET_SEEN(b1); \
245 BUILD_BUG_ON(((unsigned long) imm) > 0xff); \
246 })
247
248 #define EMIT6_PCREL(op1, op2, b1, b2, i, off, mask) \
249 ({ \
250 /* Branch instruction needs 6 bytes */ \
251 int rel = (addrs[i + off + 1] - (addrs[i + 1] - 6)) / 2;\
252 _EMIT6(op1 | reg(b1, b2) << 16 | (rel & 0xffff), op2 | mask); \
253 REG_SET_SEEN(b1); \
254 REG_SET_SEEN(b2); \
255 })
256
257 #define EMIT6_PCREL_RILB(op, b, target) \
258 ({ \
259 int rel = (target - jit->prg) / 2; \
260 _EMIT6(op | reg_high(b) << 16 | rel >> 16, rel & 0xffff); \
261 REG_SET_SEEN(b); \
262 })
263
264 #define EMIT6_PCREL_RIL(op, target) \
265 ({ \
266 int rel = (target - jit->prg) / 2; \
267 _EMIT6(op | rel >> 16, rel & 0xffff); \
268 })
269
270 #define _EMIT6_IMM(op, imm) \
271 ({ \
272 unsigned int __imm = (imm); \
273 _EMIT6(op | (__imm >> 16), __imm & 0xffff); \
274 })
275
276 #define EMIT6_IMM(op, b1, imm) \
277 ({ \
278 _EMIT6_IMM(op | reg_high(b1) << 16, imm); \
279 REG_SET_SEEN(b1); \
280 })
281
282 #define EMIT_CONST_U32(val) \
283 ({ \
284 unsigned int ret; \
285 ret = jit->lit - jit->base_ip; \
286 jit->seen |= SEEN_LITERAL; \
287 if (jit->prg_buf) \
288 *(u32 *) (jit->prg_buf + jit->lit) = (u32) val; \
289 jit->lit += 4; \
290 ret; \
291 })
292
293 #define EMIT_CONST_U64(val) \
294 ({ \
295 unsigned int ret; \
296 ret = jit->lit - jit->base_ip; \
297 jit->seen |= SEEN_LITERAL; \
298 if (jit->prg_buf) \
299 *(u64 *) (jit->prg_buf + jit->lit) = (u64) val; \
300 jit->lit += 8; \
301 ret; \
302 })
303
304 #define EMIT_ZERO(b1) \
305 ({ \
306 /* llgfr %dst,%dst (zero extend to 64 bit) */ \
307 EMIT4(0xb9160000, b1, b1); \
308 REG_SET_SEEN(b1); \
309 })
310
311 /*
312 * Fill whole space with illegal instructions
313 */
314 static void jit_fill_hole(void *area, unsigned int size)
315 {
316 memset(area, 0, size);
317 }
318
319 /*
320 * Save registers from "rs" (register start) to "re" (register end) on stack
321 */
322 static void save_regs(struct bpf_jit *jit, u32 rs, u32 re)
323 {
324 u32 off = STK_OFF_R6 + (rs - 6) * 8;
325
326 if (rs == re)
327 /* stg %rs,off(%r15) */
328 _EMIT6(0xe300f000 | rs << 20 | off, 0x0024);
329 else
330 /* stmg %rs,%re,off(%r15) */
331 _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0024, off);
332 }
333
334 /*
335 * Restore registers from "rs" (register start) to "re" (register end) on stack
336 */
337 static void restore_regs(struct bpf_jit *jit, u32 rs, u32 re, u32 stack_depth)
338 {
339 u32 off = STK_OFF_R6 + (rs - 6) * 8;
340
341 if (jit->seen & SEEN_STACK)
342 off += STK_OFF + stack_depth;
343
344 if (rs == re)
345 /* lg %rs,off(%r15) */
346 _EMIT6(0xe300f000 | rs << 20 | off, 0x0004);
347 else
348 /* lmg %rs,%re,off(%r15) */
349 _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0004, off);
350 }
351
352 /*
353 * Return first seen register (from start)
354 */
355 static int get_start(struct bpf_jit *jit, int start)
356 {
357 int i;
358
359 for (i = start; i <= 15; i++) {
360 if (jit->seen_reg[i])
361 return i;
362 }
363 return 0;
364 }
365
366 /*
367 * Return last seen register (from start) (gap >= 2)
368 */
369 static int get_end(struct bpf_jit *jit, int start)
370 {
371 int i;
372
373 for (i = start; i < 15; i++) {
374 if (!jit->seen_reg[i] && !jit->seen_reg[i + 1])
375 return i - 1;
376 }
377 return jit->seen_reg[15] ? 15 : 14;
378 }
379
380 #define REGS_SAVE 1
381 #define REGS_RESTORE 0
382 /*
383 * Save and restore clobbered registers (6-15) on stack.
384 * We save/restore registers in chunks with gap >= 2 registers.
385 */
386 static void save_restore_regs(struct bpf_jit *jit, int op, u32 stack_depth)
387 {
388
389 int re = 6, rs;
390
391 do {
392 rs = get_start(jit, re);
393 if (!rs)
394 break;
395 re = get_end(jit, rs + 1);
396 if (op == REGS_SAVE)
397 save_regs(jit, rs, re);
398 else
399 restore_regs(jit, rs, re, stack_depth);
400 re++;
401 } while (re <= 15);
402 }
403
404 /*
405 * For SKB access %b1 contains the SKB pointer. For "bpf_jit.S"
406 * we store the SKB header length on the stack and the SKB data
407 * pointer in REG_SKB_DATA if BPF_REG_AX is not used.
408 */
409 static void emit_load_skb_data_hlen(struct bpf_jit *jit)
410 {
411 /* Header length: llgf %w1,<len>(%b1) */
412 EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_1,
413 offsetof(struct sk_buff, len));
414 /* s %w1,<data_len>(%b1) */
415 EMIT4_DISP(0x5b000000, REG_W1, BPF_REG_1,
416 offsetof(struct sk_buff, data_len));
417 /* stg %w1,ST_OFF_HLEN(%r0,%r15) */
418 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, REG_15, STK_OFF_HLEN);
419 if (!(jit->seen & SEEN_REG_AX))
420 /* lg %skb_data,data_off(%b1) */
421 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0,
422 BPF_REG_1, offsetof(struct sk_buff, data));
423 }
424
425 /*
426 * Emit function prologue
427 *
428 * Save registers and create stack frame if necessary.
429 * See stack frame layout desription in "bpf_jit.h"!
430 */
431 static void bpf_jit_prologue(struct bpf_jit *jit, u32 stack_depth)
432 {
433 if (jit->seen & SEEN_TAIL_CALL) {
434 /* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */
435 _EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT);
436 } else {
437 /* j tail_call_start: NOP if no tail calls are used */
438 EMIT4_PCREL(0xa7f40000, 6);
439 _EMIT2(0);
440 }
441 /* Tail calls have to skip above initialization */
442 jit->tail_call_start = jit->prg;
443 /* Save registers */
444 save_restore_regs(jit, REGS_SAVE, stack_depth);
445 /* Setup literal pool */
446 if (jit->seen & SEEN_LITERAL) {
447 /* basr %r13,0 */
448 EMIT2(0x0d00, REG_L, REG_0);
449 jit->base_ip = jit->prg;
450 }
451 /* Setup stack and backchain */
452 if (jit->seen & SEEN_STACK) {
453 if (jit->seen & SEEN_FUNC)
454 /* lgr %w1,%r15 (backchain) */
455 EMIT4(0xb9040000, REG_W1, REG_15);
456 /* la %bfp,STK_160_UNUSED(%r15) (BPF frame pointer) */
457 EMIT4_DISP(0x41000000, BPF_REG_FP, REG_15, STK_160_UNUSED);
458 /* aghi %r15,-STK_OFF */
459 EMIT4_IMM(0xa70b0000, REG_15, -(STK_OFF + stack_depth));
460 if (jit->seen & SEEN_FUNC)
461 /* stg %w1,152(%r15) (backchain) */
462 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0,
463 REG_15, 152);
464 }
465 if (jit->seen & SEEN_SKB) {
466 emit_load_skb_data_hlen(jit);
467 /* stg %b1,ST_OFF_SKBP(%r0,%r15) */
468 EMIT6_DISP_LH(0xe3000000, 0x0024, BPF_REG_1, REG_0, REG_15,
469 STK_OFF_SKBP);
470 }
471 }
472
473 /*
474 * Function epilogue
475 */
476 static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
477 {
478 /* Return 0 */
479 if (jit->seen & SEEN_RET0) {
480 jit->ret0_ip = jit->prg;
481 /* lghi %b0,0 */
482 EMIT4_IMM(0xa7090000, BPF_REG_0, 0);
483 }
484 jit->exit_ip = jit->prg;
485 /* Load exit code: lgr %r2,%b0 */
486 EMIT4(0xb9040000, REG_2, BPF_REG_0);
487 /* Restore registers */
488 save_restore_regs(jit, REGS_RESTORE, stack_depth);
489 if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable) {
490 jit->r14_thunk_ip = jit->prg;
491 /* Generate __s390_indirect_jump_r14 thunk */
492 if (test_facility(35)) {
493 /* exrl %r0,.+10 */
494 EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
495 } else {
496 /* larl %r1,.+14 */
497 EMIT6_PCREL_RILB(0xc0000000, REG_1, jit->prg + 14);
498 /* ex 0,0(%r1) */
499 EMIT4_DISP(0x44000000, REG_0, REG_1, 0);
500 }
501 /* j . */
502 EMIT4_PCREL(0xa7f40000, 0);
503 }
504 /* br %r14 */
505 _EMIT2(0x07fe);
506
507 if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable &&
508 (jit->seen & SEEN_FUNC)) {
509 jit->r1_thunk_ip = jit->prg;
510 /* Generate __s390_indirect_jump_r1 thunk */
511 if (test_facility(35)) {
512 /* exrl %r0,.+10 */
513 EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
514 /* j . */
515 EMIT4_PCREL(0xa7f40000, 0);
516 /* br %r1 */
517 _EMIT2(0x07f1);
518 } else {
519 /* larl %r1,.+14 */
520 EMIT6_PCREL_RILB(0xc0000000, REG_1, jit->prg + 14);
521 /* ex 0,S390_lowcore.br_r1_tampoline */
522 EMIT4_DISP(0x44000000, REG_0, REG_0,
523 offsetof(struct lowcore, br_r1_trampoline));
524 /* j . */
525 EMIT4_PCREL(0xa7f40000, 0);
526 }
527 }
528 }
529
530 /*
531 * Compile one eBPF instruction into s390x code
532 *
533 * NOTE: Use noinline because for gcov (-fprofile-arcs) gcc allocates a lot of
534 * stack space for the large switch statement.
535 */
536 static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i)
537 {
538 struct bpf_insn *insn = &fp->insnsi[i];
539 int jmp_off, last, insn_count = 1;
540 unsigned int func_addr, mask;
541 u32 dst_reg = insn->dst_reg;
542 u32 src_reg = insn->src_reg;
543 u32 *addrs = jit->addrs;
544 s32 imm = insn->imm;
545 s16 off = insn->off;
546
547 if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX)
548 jit->seen |= SEEN_REG_AX;
549 switch (insn->code) {
550 /*
551 * BPF_MOV
552 */
553 case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */
554 /* llgfr %dst,%src */
555 EMIT4(0xb9160000, dst_reg, src_reg);
556 break;
557 case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
558 /* lgr %dst,%src */
559 EMIT4(0xb9040000, dst_reg, src_reg);
560 break;
561 case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */
562 /* llilf %dst,imm */
563 EMIT6_IMM(0xc00f0000, dst_reg, imm);
564 break;
565 case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */
566 /* lgfi %dst,imm */
567 EMIT6_IMM(0xc0010000, dst_reg, imm);
568 break;
569 /*
570 * BPF_LD 64
571 */
572 case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
573 {
574 /* 16 byte instruction that uses two 'struct bpf_insn' */
575 u64 imm64;
576
577 imm64 = (u64)(u32) insn[0].imm | ((u64)(u32) insn[1].imm) << 32;
578 /* lg %dst,<d(imm)>(%l) */
579 EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, REG_0, REG_L,
580 EMIT_CONST_U64(imm64));
581 insn_count = 2;
582 break;
583 }
584 /*
585 * BPF_ADD
586 */
587 case BPF_ALU | BPF_ADD | BPF_X: /* dst = (u32) dst + (u32) src */
588 /* ar %dst,%src */
589 EMIT2(0x1a00, dst_reg, src_reg);
590 EMIT_ZERO(dst_reg);
591 break;
592 case BPF_ALU64 | BPF_ADD | BPF_X: /* dst = dst + src */
593 /* agr %dst,%src */
594 EMIT4(0xb9080000, dst_reg, src_reg);
595 break;
596 case BPF_ALU | BPF_ADD | BPF_K: /* dst = (u32) dst + (u32) imm */
597 if (!imm)
598 break;
599 /* alfi %dst,imm */
600 EMIT6_IMM(0xc20b0000, dst_reg, imm);
601 EMIT_ZERO(dst_reg);
602 break;
603 case BPF_ALU64 | BPF_ADD | BPF_K: /* dst = dst + imm */
604 if (!imm)
605 break;
606 /* agfi %dst,imm */
607 EMIT6_IMM(0xc2080000, dst_reg, imm);
608 break;
609 /*
610 * BPF_SUB
611 */
612 case BPF_ALU | BPF_SUB | BPF_X: /* dst = (u32) dst - (u32) src */
613 /* sr %dst,%src */
614 EMIT2(0x1b00, dst_reg, src_reg);
615 EMIT_ZERO(dst_reg);
616 break;
617 case BPF_ALU64 | BPF_SUB | BPF_X: /* dst = dst - src */
618 /* sgr %dst,%src */
619 EMIT4(0xb9090000, dst_reg, src_reg);
620 break;
621 case BPF_ALU | BPF_SUB | BPF_K: /* dst = (u32) dst - (u32) imm */
622 if (!imm)
623 break;
624 /* alfi %dst,-imm */
625 EMIT6_IMM(0xc20b0000, dst_reg, -imm);
626 EMIT_ZERO(dst_reg);
627 break;
628 case BPF_ALU64 | BPF_SUB | BPF_K: /* dst = dst - imm */
629 if (!imm)
630 break;
631 /* agfi %dst,-imm */
632 EMIT6_IMM(0xc2080000, dst_reg, -imm);
633 break;
634 /*
635 * BPF_MUL
636 */
637 case BPF_ALU | BPF_MUL | BPF_X: /* dst = (u32) dst * (u32) src */
638 /* msr %dst,%src */
639 EMIT4(0xb2520000, dst_reg, src_reg);
640 EMIT_ZERO(dst_reg);
641 break;
642 case BPF_ALU64 | BPF_MUL | BPF_X: /* dst = dst * src */
643 /* msgr %dst,%src */
644 EMIT4(0xb90c0000, dst_reg, src_reg);
645 break;
646 case BPF_ALU | BPF_MUL | BPF_K: /* dst = (u32) dst * (u32) imm */
647 if (imm == 1)
648 break;
649 /* msfi %r5,imm */
650 EMIT6_IMM(0xc2010000, dst_reg, imm);
651 EMIT_ZERO(dst_reg);
652 break;
653 case BPF_ALU64 | BPF_MUL | BPF_K: /* dst = dst * imm */
654 if (imm == 1)
655 break;
656 /* msgfi %dst,imm */
657 EMIT6_IMM(0xc2000000, dst_reg, imm);
658 break;
659 /*
660 * BPF_DIV / BPF_MOD
661 */
662 case BPF_ALU | BPF_DIV | BPF_X: /* dst = (u32) dst / (u32) src */
663 case BPF_ALU | BPF_MOD | BPF_X: /* dst = (u32) dst % (u32) src */
664 {
665 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
666
667 /* lhi %w0,0 */
668 EMIT4_IMM(0xa7080000, REG_W0, 0);
669 /* lr %w1,%dst */
670 EMIT2(0x1800, REG_W1, dst_reg);
671 /* dlr %w0,%src */
672 EMIT4(0xb9970000, REG_W0, src_reg);
673 /* llgfr %dst,%rc */
674 EMIT4(0xb9160000, dst_reg, rc_reg);
675 break;
676 }
677 case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */
678 case BPF_ALU64 | BPF_MOD | BPF_X: /* dst = dst % src */
679 {
680 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
681
682 /* lghi %w0,0 */
683 EMIT4_IMM(0xa7090000, REG_W0, 0);
684 /* lgr %w1,%dst */
685 EMIT4(0xb9040000, REG_W1, dst_reg);
686 /* dlgr %w0,%dst */
687 EMIT4(0xb9870000, REG_W0, src_reg);
688 /* lgr %dst,%rc */
689 EMIT4(0xb9040000, dst_reg, rc_reg);
690 break;
691 }
692 case BPF_ALU | BPF_DIV | BPF_K: /* dst = (u32) dst / (u32) imm */
693 case BPF_ALU | BPF_MOD | BPF_K: /* dst = (u32) dst % (u32) imm */
694 {
695 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
696
697 if (imm == 1) {
698 if (BPF_OP(insn->code) == BPF_MOD)
699 /* lhgi %dst,0 */
700 EMIT4_IMM(0xa7090000, dst_reg, 0);
701 break;
702 }
703 /* lhi %w0,0 */
704 EMIT4_IMM(0xa7080000, REG_W0, 0);
705 /* lr %w1,%dst */
706 EMIT2(0x1800, REG_W1, dst_reg);
707 /* dl %w0,<d(imm)>(%l) */
708 EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0, REG_L,
709 EMIT_CONST_U32(imm));
710 /* llgfr %dst,%rc */
711 EMIT4(0xb9160000, dst_reg, rc_reg);
712 break;
713 }
714 case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */
715 case BPF_ALU64 | BPF_MOD | BPF_K: /* dst = dst % imm */
716 {
717 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
718
719 if (imm == 1) {
720 if (BPF_OP(insn->code) == BPF_MOD)
721 /* lhgi %dst,0 */
722 EMIT4_IMM(0xa7090000, dst_reg, 0);
723 break;
724 }
725 /* lghi %w0,0 */
726 EMIT4_IMM(0xa7090000, REG_W0, 0);
727 /* lgr %w1,%dst */
728 EMIT4(0xb9040000, REG_W1, dst_reg);
729 /* dlg %w0,<d(imm)>(%l) */
730 EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0, REG_L,
731 EMIT_CONST_U64(imm));
732 /* lgr %dst,%rc */
733 EMIT4(0xb9040000, dst_reg, rc_reg);
734 break;
735 }
736 /*
737 * BPF_AND
738 */
739 case BPF_ALU | BPF_AND | BPF_X: /* dst = (u32) dst & (u32) src */
740 /* nr %dst,%src */
741 EMIT2(0x1400, dst_reg, src_reg);
742 EMIT_ZERO(dst_reg);
743 break;
744 case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
745 /* ngr %dst,%src */
746 EMIT4(0xb9800000, dst_reg, src_reg);
747 break;
748 case BPF_ALU | BPF_AND | BPF_K: /* dst = (u32) dst & (u32) imm */
749 /* nilf %dst,imm */
750 EMIT6_IMM(0xc00b0000, dst_reg, imm);
751 EMIT_ZERO(dst_reg);
752 break;
753 case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
754 /* ng %dst,<d(imm)>(%l) */
755 EMIT6_DISP_LH(0xe3000000, 0x0080, dst_reg, REG_0, REG_L,
756 EMIT_CONST_U64(imm));
757 break;
758 /*
759 * BPF_OR
760 */
761 case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
762 /* or %dst,%src */
763 EMIT2(0x1600, dst_reg, src_reg);
764 EMIT_ZERO(dst_reg);
765 break;
766 case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
767 /* ogr %dst,%src */
768 EMIT4(0xb9810000, dst_reg, src_reg);
769 break;
770 case BPF_ALU | BPF_OR | BPF_K: /* dst = (u32) dst | (u32) imm */
771 /* oilf %dst,imm */
772 EMIT6_IMM(0xc00d0000, dst_reg, imm);
773 EMIT_ZERO(dst_reg);
774 break;
775 case BPF_ALU64 | BPF_OR | BPF_K: /* dst = dst | imm */
776 /* og %dst,<d(imm)>(%l) */
777 EMIT6_DISP_LH(0xe3000000, 0x0081, dst_reg, REG_0, REG_L,
778 EMIT_CONST_U64(imm));
779 break;
780 /*
781 * BPF_XOR
782 */
783 case BPF_ALU | BPF_XOR | BPF_X: /* dst = (u32) dst ^ (u32) src */
784 /* xr %dst,%src */
785 EMIT2(0x1700, dst_reg, src_reg);
786 EMIT_ZERO(dst_reg);
787 break;
788 case BPF_ALU64 | BPF_XOR | BPF_X: /* dst = dst ^ src */
789 /* xgr %dst,%src */
790 EMIT4(0xb9820000, dst_reg, src_reg);
791 break;
792 case BPF_ALU | BPF_XOR | BPF_K: /* dst = (u32) dst ^ (u32) imm */
793 if (!imm)
794 break;
795 /* xilf %dst,imm */
796 EMIT6_IMM(0xc0070000, dst_reg, imm);
797 EMIT_ZERO(dst_reg);
798 break;
799 case BPF_ALU64 | BPF_XOR | BPF_K: /* dst = dst ^ imm */
800 /* xg %dst,<d(imm)>(%l) */
801 EMIT6_DISP_LH(0xe3000000, 0x0082, dst_reg, REG_0, REG_L,
802 EMIT_CONST_U64(imm));
803 break;
804 /*
805 * BPF_LSH
806 */
807 case BPF_ALU | BPF_LSH | BPF_X: /* dst = (u32) dst << (u32) src */
808 /* sll %dst,0(%src) */
809 EMIT4_DISP(0x89000000, dst_reg, src_reg, 0);
810 EMIT_ZERO(dst_reg);
811 break;
812 case BPF_ALU64 | BPF_LSH | BPF_X: /* dst = dst << src */
813 /* sllg %dst,%dst,0(%src) */
814 EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, src_reg, 0);
815 break;
816 case BPF_ALU | BPF_LSH | BPF_K: /* dst = (u32) dst << (u32) imm */
817 if (imm == 0)
818 break;
819 /* sll %dst,imm(%r0) */
820 EMIT4_DISP(0x89000000, dst_reg, REG_0, imm);
821 EMIT_ZERO(dst_reg);
822 break;
823 case BPF_ALU64 | BPF_LSH | BPF_K: /* dst = dst << imm */
824 if (imm == 0)
825 break;
826 /* sllg %dst,%dst,imm(%r0) */
827 EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, REG_0, imm);
828 break;
829 /*
830 * BPF_RSH
831 */
832 case BPF_ALU | BPF_RSH | BPF_X: /* dst = (u32) dst >> (u32) src */
833 /* srl %dst,0(%src) */
834 EMIT4_DISP(0x88000000, dst_reg, src_reg, 0);
835 EMIT_ZERO(dst_reg);
836 break;
837 case BPF_ALU64 | BPF_RSH | BPF_X: /* dst = dst >> src */
838 /* srlg %dst,%dst,0(%src) */
839 EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, src_reg, 0);
840 break;
841 case BPF_ALU | BPF_RSH | BPF_K: /* dst = (u32) dst >> (u32) imm */
842 if (imm == 0)
843 break;
844 /* srl %dst,imm(%r0) */
845 EMIT4_DISP(0x88000000, dst_reg, REG_0, imm);
846 EMIT_ZERO(dst_reg);
847 break;
848 case BPF_ALU64 | BPF_RSH | BPF_K: /* dst = dst >> imm */
849 if (imm == 0)
850 break;
851 /* srlg %dst,%dst,imm(%r0) */
852 EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, REG_0, imm);
853 break;
854 /*
855 * BPF_ARSH
856 */
857 case BPF_ALU64 | BPF_ARSH | BPF_X: /* ((s64) dst) >>= src */
858 /* srag %dst,%dst,0(%src) */
859 EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, src_reg, 0);
860 break;
861 case BPF_ALU64 | BPF_ARSH | BPF_K: /* ((s64) dst) >>= imm */
862 if (imm == 0)
863 break;
864 /* srag %dst,%dst,imm(%r0) */
865 EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, REG_0, imm);
866 break;
867 /*
868 * BPF_NEG
869 */
870 case BPF_ALU | BPF_NEG: /* dst = (u32) -dst */
871 /* lcr %dst,%dst */
872 EMIT2(0x1300, dst_reg, dst_reg);
873 EMIT_ZERO(dst_reg);
874 break;
875 case BPF_ALU64 | BPF_NEG: /* dst = -dst */
876 /* lcgr %dst,%dst */
877 EMIT4(0xb9130000, dst_reg, dst_reg);
878 break;
879 /*
880 * BPF_FROM_BE/LE
881 */
882 case BPF_ALU | BPF_END | BPF_FROM_BE:
883 /* s390 is big endian, therefore only clear high order bytes */
884 switch (imm) {
885 case 16: /* dst = (u16) cpu_to_be16(dst) */
886 /* llghr %dst,%dst */
887 EMIT4(0xb9850000, dst_reg, dst_reg);
888 break;
889 case 32: /* dst = (u32) cpu_to_be32(dst) */
890 /* llgfr %dst,%dst */
891 EMIT4(0xb9160000, dst_reg, dst_reg);
892 break;
893 case 64: /* dst = (u64) cpu_to_be64(dst) */
894 break;
895 }
896 break;
897 case BPF_ALU | BPF_END | BPF_FROM_LE:
898 switch (imm) {
899 case 16: /* dst = (u16) cpu_to_le16(dst) */
900 /* lrvr %dst,%dst */
901 EMIT4(0xb91f0000, dst_reg, dst_reg);
902 /* srl %dst,16(%r0) */
903 EMIT4_DISP(0x88000000, dst_reg, REG_0, 16);
904 /* llghr %dst,%dst */
905 EMIT4(0xb9850000, dst_reg, dst_reg);
906 break;
907 case 32: /* dst = (u32) cpu_to_le32(dst) */
908 /* lrvr %dst,%dst */
909 EMIT4(0xb91f0000, dst_reg, dst_reg);
910 /* llgfr %dst,%dst */
911 EMIT4(0xb9160000, dst_reg, dst_reg);
912 break;
913 case 64: /* dst = (u64) cpu_to_le64(dst) */
914 /* lrvgr %dst,%dst */
915 EMIT4(0xb90f0000, dst_reg, dst_reg);
916 break;
917 }
918 break;
919 /*
920 * BPF_ST(X)
921 */
922 case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src_reg */
923 /* stcy %src,off(%dst) */
924 EMIT6_DISP_LH(0xe3000000, 0x0072, src_reg, dst_reg, REG_0, off);
925 jit->seen |= SEEN_MEM;
926 break;
927 case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
928 /* sthy %src,off(%dst) */
929 EMIT6_DISP_LH(0xe3000000, 0x0070, src_reg, dst_reg, REG_0, off);
930 jit->seen |= SEEN_MEM;
931 break;
932 case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
933 /* sty %src,off(%dst) */
934 EMIT6_DISP_LH(0xe3000000, 0x0050, src_reg, dst_reg, REG_0, off);
935 jit->seen |= SEEN_MEM;
936 break;
937 case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
938 /* stg %src,off(%dst) */
939 EMIT6_DISP_LH(0xe3000000, 0x0024, src_reg, dst_reg, REG_0, off);
940 jit->seen |= SEEN_MEM;
941 break;
942 case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
943 /* lhi %w0,imm */
944 EMIT4_IMM(0xa7080000, REG_W0, (u8) imm);
945 /* stcy %w0,off(dst) */
946 EMIT6_DISP_LH(0xe3000000, 0x0072, REG_W0, dst_reg, REG_0, off);
947 jit->seen |= SEEN_MEM;
948 break;
949 case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
950 /* lhi %w0,imm */
951 EMIT4_IMM(0xa7080000, REG_W0, (u16) imm);
952 /* sthy %w0,off(dst) */
953 EMIT6_DISP_LH(0xe3000000, 0x0070, REG_W0, dst_reg, REG_0, off);
954 jit->seen |= SEEN_MEM;
955 break;
956 case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
957 /* llilf %w0,imm */
958 EMIT6_IMM(0xc00f0000, REG_W0, (u32) imm);
959 /* sty %w0,off(%dst) */
960 EMIT6_DISP_LH(0xe3000000, 0x0050, REG_W0, dst_reg, REG_0, off);
961 jit->seen |= SEEN_MEM;
962 break;
963 case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
964 /* lgfi %w0,imm */
965 EMIT6_IMM(0xc0010000, REG_W0, imm);
966 /* stg %w0,off(%dst) */
967 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W0, dst_reg, REG_0, off);
968 jit->seen |= SEEN_MEM;
969 break;
970 /*
971 * BPF_STX XADD (atomic_add)
972 */
973 case BPF_STX | BPF_XADD | BPF_W: /* *(u32 *)(dst + off) += src */
974 /* laal %w0,%src,off(%dst) */
975 EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W0, src_reg,
976 dst_reg, off);
977 jit->seen |= SEEN_MEM;
978 break;
979 case BPF_STX | BPF_XADD | BPF_DW: /* *(u64 *)(dst + off) += src */
980 /* laalg %w0,%src,off(%dst) */
981 EMIT6_DISP_LH(0xeb000000, 0x00ea, REG_W0, src_reg,
982 dst_reg, off);
983 jit->seen |= SEEN_MEM;
984 break;
985 /*
986 * BPF_LDX
987 */
988 case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */
989 /* llgc %dst,0(off,%src) */
990 EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off);
991 jit->seen |= SEEN_MEM;
992 break;
993 case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */
994 /* llgh %dst,0(off,%src) */
995 EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off);
996 jit->seen |= SEEN_MEM;
997 break;
998 case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */
999 /* llgf %dst,off(%src) */
1000 jit->seen |= SEEN_MEM;
1001 EMIT6_DISP_LH(0xe3000000, 0x0016, dst_reg, src_reg, REG_0, off);
1002 break;
1003 case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
1004 /* lg %dst,0(off,%src) */
1005 jit->seen |= SEEN_MEM;
1006 EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, src_reg, REG_0, off);
1007 break;
1008 /*
1009 * BPF_JMP / CALL
1010 */
1011 case BPF_JMP | BPF_CALL:
1012 {
1013 /*
1014 * b0 = (__bpf_call_base + imm)(b1, b2, b3, b4, b5)
1015 */
1016 const u64 func = (u64)__bpf_call_base + imm;
1017
1018 REG_SET_SEEN(BPF_REG_5);
1019 jit->seen |= SEEN_FUNC;
1020 /* lg %w1,<d(imm)>(%l) */
1021 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_W1, REG_0, REG_L,
1022 EMIT_CONST_U64(func));
1023 if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable) {
1024 /* brasl %r14,__s390_indirect_jump_r1 */
1025 EMIT6_PCREL_RILB(0xc0050000, REG_14, jit->r1_thunk_ip);
1026 } else {
1027 /* basr %r14,%w1 */
1028 EMIT2(0x0d00, REG_14, REG_W1);
1029 }
1030 /* lgr %b0,%r2: load return value into %b0 */
1031 EMIT4(0xb9040000, BPF_REG_0, REG_2);
1032 if ((jit->seen & SEEN_SKB) &&
1033 bpf_helper_changes_pkt_data((void *)func)) {
1034 /* lg %b1,ST_OFF_SKBP(%r15) */
1035 EMIT6_DISP_LH(0xe3000000, 0x0004, BPF_REG_1, REG_0,
1036 REG_15, STK_OFF_SKBP);
1037 emit_load_skb_data_hlen(jit);
1038 }
1039 break;
1040 }
1041 case BPF_JMP | BPF_TAIL_CALL:
1042 /*
1043 * Implicit input:
1044 * B1: pointer to ctx
1045 * B2: pointer to bpf_array
1046 * B3: index in bpf_array
1047 */
1048 jit->seen |= SEEN_TAIL_CALL;
1049
1050 /*
1051 * if (index >= array->map.max_entries)
1052 * goto out;
1053 */
1054
1055 /* llgf %w1,map.max_entries(%b2) */
1056 EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_2,
1057 offsetof(struct bpf_array, map.max_entries));
1058 /* clgrj %b3,%w1,0xa,label0: if %b3 >= %w1 goto out */
1059 EMIT6_PCREL_LABEL(0xec000000, 0x0065, BPF_REG_3,
1060 REG_W1, 0, 0xa);
1061
1062 /*
1063 * if (tail_call_cnt++ > MAX_TAIL_CALL_CNT)
1064 * goto out;
1065 */
1066
1067 if (jit->seen & SEEN_STACK)
1068 off = STK_OFF_TCCNT + STK_OFF + fp->aux->stack_depth;
1069 else
1070 off = STK_OFF_TCCNT;
1071 /* lhi %w0,1 */
1072 EMIT4_IMM(0xa7080000, REG_W0, 1);
1073 /* laal %w1,%w0,off(%r15) */
1074 EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, REG_15, off);
1075 /* clij %w1,MAX_TAIL_CALL_CNT,0x2,label0 */
1076 EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007f, REG_W1,
1077 MAX_TAIL_CALL_CNT, 0, 0x2);
1078
1079 /*
1080 * prog = array->ptrs[index];
1081 * if (prog == NULL)
1082 * goto out;
1083 */
1084
1085 /* sllg %r1,%b3,3: %r1 = index * 8 */
1086 EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, BPF_REG_3, REG_0, 3);
1087 /* lg %r1,prog(%b2,%r1) */
1088 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, BPF_REG_2,
1089 REG_1, offsetof(struct bpf_array, ptrs));
1090 /* clgij %r1,0,0x8,label0 */
1091 EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007d, REG_1, 0, 0, 0x8);
1092
1093 /*
1094 * Restore registers before calling function
1095 */
1096 save_restore_regs(jit, REGS_RESTORE, fp->aux->stack_depth);
1097
1098 /*
1099 * goto *(prog->bpf_func + tail_call_start);
1100 */
1101
1102 /* lg %r1,bpf_func(%r1) */
1103 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, REG_1, REG_0,
1104 offsetof(struct bpf_prog, bpf_func));
1105 /* bc 0xf,tail_call_start(%r1) */
1106 _EMIT4(0x47f01000 + jit->tail_call_start);
1107 /* out: */
1108 jit->labels[0] = jit->prg;
1109 break;
1110 case BPF_JMP | BPF_EXIT: /* return b0 */
1111 last = (i == fp->len - 1) ? 1 : 0;
1112 if (last && !(jit->seen & SEEN_RET0))
1113 break;
1114 /* j <exit> */
1115 EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);
1116 break;
1117 /*
1118 * Branch relative (number of skipped instructions) to offset on
1119 * condition.
1120 *
1121 * Condition code to mask mapping:
1122 *
1123 * CC | Description | Mask
1124 * ------------------------------
1125 * 0 | Operands equal | 8
1126 * 1 | First operand low | 4
1127 * 2 | First operand high | 2
1128 * 3 | Unused | 1
1129 *
1130 * For s390x relative branches: ip = ip + off_bytes
1131 * For BPF relative branches: insn = insn + off_insns + 1
1132 *
1133 * For example for s390x with offset 0 we jump to the branch
1134 * instruction itself (loop) and for BPF with offset 0 we
1135 * branch to the instruction behind the branch.
1136 */
1137 case BPF_JMP | BPF_JA: /* if (true) */
1138 mask = 0xf000; /* j */
1139 goto branch_oc;
1140 case BPF_JMP | BPF_JSGT | BPF_K: /* ((s64) dst > (s64) imm) */
1141 mask = 0x2000; /* jh */
1142 goto branch_ks;
1143 case BPF_JMP | BPF_JSLT | BPF_K: /* ((s64) dst < (s64) imm) */
1144 mask = 0x4000; /* jl */
1145 goto branch_ks;
1146 case BPF_JMP | BPF_JSGE | BPF_K: /* ((s64) dst >= (s64) imm) */
1147 mask = 0xa000; /* jhe */
1148 goto branch_ks;
1149 case BPF_JMP | BPF_JSLE | BPF_K: /* ((s64) dst <= (s64) imm) */
1150 mask = 0xc000; /* jle */
1151 goto branch_ks;
1152 case BPF_JMP | BPF_JGT | BPF_K: /* (dst_reg > imm) */
1153 mask = 0x2000; /* jh */
1154 goto branch_ku;
1155 case BPF_JMP | BPF_JLT | BPF_K: /* (dst_reg < imm) */
1156 mask = 0x4000; /* jl */
1157 goto branch_ku;
1158 case BPF_JMP | BPF_JGE | BPF_K: /* (dst_reg >= imm) */
1159 mask = 0xa000; /* jhe */
1160 goto branch_ku;
1161 case BPF_JMP | BPF_JLE | BPF_K: /* (dst_reg <= imm) */
1162 mask = 0xc000; /* jle */
1163 goto branch_ku;
1164 case BPF_JMP | BPF_JNE | BPF_K: /* (dst_reg != imm) */
1165 mask = 0x7000; /* jne */
1166 goto branch_ku;
1167 case BPF_JMP | BPF_JEQ | BPF_K: /* (dst_reg == imm) */
1168 mask = 0x8000; /* je */
1169 goto branch_ku;
1170 case BPF_JMP | BPF_JSET | BPF_K: /* (dst_reg & imm) */
1171 mask = 0x7000; /* jnz */
1172 /* lgfi %w1,imm (load sign extend imm) */
1173 EMIT6_IMM(0xc0010000, REG_W1, imm);
1174 /* ngr %w1,%dst */
1175 EMIT4(0xb9800000, REG_W1, dst_reg);
1176 goto branch_oc;
1177
1178 case BPF_JMP | BPF_JSGT | BPF_X: /* ((s64) dst > (s64) src) */
1179 mask = 0x2000; /* jh */
1180 goto branch_xs;
1181 case BPF_JMP | BPF_JSLT | BPF_X: /* ((s64) dst < (s64) src) */
1182 mask = 0x4000; /* jl */
1183 goto branch_xs;
1184 case BPF_JMP | BPF_JSGE | BPF_X: /* ((s64) dst >= (s64) src) */
1185 mask = 0xa000; /* jhe */
1186 goto branch_xs;
1187 case BPF_JMP | BPF_JSLE | BPF_X: /* ((s64) dst <= (s64) src) */
1188 mask = 0xc000; /* jle */
1189 goto branch_xs;
1190 case BPF_JMP | BPF_JGT | BPF_X: /* (dst > src) */
1191 mask = 0x2000; /* jh */
1192 goto branch_xu;
1193 case BPF_JMP | BPF_JLT | BPF_X: /* (dst < src) */
1194 mask = 0x4000; /* jl */
1195 goto branch_xu;
1196 case BPF_JMP | BPF_JGE | BPF_X: /* (dst >= src) */
1197 mask = 0xa000; /* jhe */
1198 goto branch_xu;
1199 case BPF_JMP | BPF_JLE | BPF_X: /* (dst <= src) */
1200 mask = 0xc000; /* jle */
1201 goto branch_xu;
1202 case BPF_JMP | BPF_JNE | BPF_X: /* (dst != src) */
1203 mask = 0x7000; /* jne */
1204 goto branch_xu;
1205 case BPF_JMP | BPF_JEQ | BPF_X: /* (dst == src) */
1206 mask = 0x8000; /* je */
1207 goto branch_xu;
1208 case BPF_JMP | BPF_JSET | BPF_X: /* (dst & src) */
1209 mask = 0x7000; /* jnz */
1210 /* ngrk %w1,%dst,%src */
1211 EMIT4_RRF(0xb9e40000, REG_W1, dst_reg, src_reg);
1212 goto branch_oc;
1213 branch_ks:
1214 /* lgfi %w1,imm (load sign extend imm) */
1215 EMIT6_IMM(0xc0010000, REG_W1, imm);
1216 /* cgrj %dst,%w1,mask,off */
1217 EMIT6_PCREL(0xec000000, 0x0064, dst_reg, REG_W1, i, off, mask);
1218 break;
1219 branch_ku:
1220 /* lgfi %w1,imm (load sign extend imm) */
1221 EMIT6_IMM(0xc0010000, REG_W1, imm);
1222 /* clgrj %dst,%w1,mask,off */
1223 EMIT6_PCREL(0xec000000, 0x0065, dst_reg, REG_W1, i, off, mask);
1224 break;
1225 branch_xs:
1226 /* cgrj %dst,%src,mask,off */
1227 EMIT6_PCREL(0xec000000, 0x0064, dst_reg, src_reg, i, off, mask);
1228 break;
1229 branch_xu:
1230 /* clgrj %dst,%src,mask,off */
1231 EMIT6_PCREL(0xec000000, 0x0065, dst_reg, src_reg, i, off, mask);
1232 break;
1233 branch_oc:
1234 /* brc mask,jmp_off (branch instruction needs 4 bytes) */
1235 jmp_off = addrs[i + off + 1] - (addrs[i + 1] - 4);
1236 EMIT4_PCREL(0xa7040000 | mask << 8, jmp_off);
1237 break;
1238 /*
1239 * BPF_LD
1240 */
1241 case BPF_LD | BPF_ABS | BPF_B: /* b0 = *(u8 *) (skb->data+imm) */
1242 case BPF_LD | BPF_IND | BPF_B: /* b0 = *(u8 *) (skb->data+imm+src) */
1243 if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
1244 func_addr = __pa(sk_load_byte_pos);
1245 else
1246 func_addr = __pa(sk_load_byte);
1247 goto call_fn;
1248 case BPF_LD | BPF_ABS | BPF_H: /* b0 = *(u16 *) (skb->data+imm) */
1249 case BPF_LD | BPF_IND | BPF_H: /* b0 = *(u16 *) (skb->data+imm+src) */
1250 if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
1251 func_addr = __pa(sk_load_half_pos);
1252 else
1253 func_addr = __pa(sk_load_half);
1254 goto call_fn;
1255 case BPF_LD | BPF_ABS | BPF_W: /* b0 = *(u32 *) (skb->data+imm) */
1256 case BPF_LD | BPF_IND | BPF_W: /* b0 = *(u32 *) (skb->data+imm+src) */
1257 if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
1258 func_addr = __pa(sk_load_word_pos);
1259 else
1260 func_addr = __pa(sk_load_word);
1261 goto call_fn;
1262 call_fn:
1263 jit->seen |= SEEN_SKB | SEEN_RET0 | SEEN_FUNC;
1264 REG_SET_SEEN(REG_14); /* Return address of possible func call */
1265
1266 /*
1267 * Implicit input:
1268 * BPF_REG_6 (R7) : skb pointer
1269 * REG_SKB_DATA (R12): skb data pointer (if no BPF_REG_AX)
1270 *
1271 * Calculated input:
1272 * BPF_REG_2 (R3) : offset of byte(s) to fetch in skb
1273 * BPF_REG_5 (R6) : return address
1274 *
1275 * Output:
1276 * BPF_REG_0 (R14): data read from skb
1277 *
1278 * Scratch registers (BPF_REG_1-5)
1279 */
1280
1281 /* Call function: llilf %w1,func_addr */
1282 EMIT6_IMM(0xc00f0000, REG_W1, func_addr);
1283
1284 /* Offset: lgfi %b2,imm */
1285 EMIT6_IMM(0xc0010000, BPF_REG_2, imm);
1286 if (BPF_MODE(insn->code) == BPF_IND)
1287 /* agfr %b2,%src (%src is s32 here) */
1288 EMIT4(0xb9180000, BPF_REG_2, src_reg);
1289
1290 /* Reload REG_SKB_DATA if BPF_REG_AX is used */
1291 if (jit->seen & SEEN_REG_AX)
1292 /* lg %skb_data,data_off(%b6) */
1293 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0,
1294 BPF_REG_6, offsetof(struct sk_buff, data));
1295 /* basr %b5,%w1 (%b5 is call saved) */
1296 EMIT2(0x0d00, BPF_REG_5, REG_W1);
1297
1298 /*
1299 * Note: For fast access we jump directly after the
1300 * jnz instruction from bpf_jit.S
1301 */
1302 /* jnz <ret0> */
1303 EMIT4_PCREL(0xa7740000, jit->ret0_ip - jit->prg);
1304 break;
1305 default: /* too complex, give up */
1306 pr_err("Unknown opcode %02x\n", insn->code);
1307 return -1;
1308 }
1309 return insn_count;
1310 }
1311
1312 /*
1313 * Compile eBPF program into s390x code
1314 */
1315 static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp)
1316 {
1317 int i, insn_count;
1318
1319 jit->lit = jit->lit_start;
1320 jit->prg = 0;
1321
1322 bpf_jit_prologue(jit, fp->aux->stack_depth);
1323 for (i = 0; i < fp->len; i += insn_count) {
1324 insn_count = bpf_jit_insn(jit, fp, i);
1325 if (insn_count < 0)
1326 return -1;
1327 /* Next instruction address */
1328 jit->addrs[i + insn_count] = jit->prg;
1329 }
1330 bpf_jit_epilogue(jit, fp->aux->stack_depth);
1331
1332 jit->lit_start = jit->prg;
1333 jit->size = jit->lit;
1334 jit->size_prg = jit->prg;
1335 return 0;
1336 }
1337
1338 /*
1339 * Compile eBPF program "fp"
1340 */
1341 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
1342 {
1343 struct bpf_prog *tmp, *orig_fp = fp;
1344 struct bpf_binary_header *header;
1345 bool tmp_blinded = false;
1346 struct bpf_jit jit;
1347 int pass;
1348
1349 if (!fp->jit_requested)
1350 return orig_fp;
1351
1352 tmp = bpf_jit_blind_constants(fp);
1353 /*
1354 * If blinding was requested and we failed during blinding,
1355 * we must fall back to the interpreter.
1356 */
1357 if (IS_ERR(tmp))
1358 return orig_fp;
1359 if (tmp != fp) {
1360 tmp_blinded = true;
1361 fp = tmp;
1362 }
1363
1364 memset(&jit, 0, sizeof(jit));
1365 jit.addrs = kcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL);
1366 if (jit.addrs == NULL) {
1367 fp = orig_fp;
1368 goto out;
1369 }
1370 /*
1371 * Three initial passes:
1372 * - 1/2: Determine clobbered registers
1373 * - 3: Calculate program size and addrs arrray
1374 */
1375 for (pass = 1; pass <= 3; pass++) {
1376 if (bpf_jit_prog(&jit, fp)) {
1377 fp = orig_fp;
1378 goto free_addrs;
1379 }
1380 }
1381 /*
1382 * Final pass: Allocate and generate program
1383 */
1384 if (jit.size >= BPF_SIZE_MAX) {
1385 fp = orig_fp;
1386 goto free_addrs;
1387 }
1388 header = bpf_jit_binary_alloc(jit.size, &jit.prg_buf, 2, jit_fill_hole);
1389 if (!header) {
1390 fp = orig_fp;
1391 goto free_addrs;
1392 }
1393 if (bpf_jit_prog(&jit, fp)) {
1394 fp = orig_fp;
1395 goto free_addrs;
1396 }
1397 if (bpf_jit_enable > 1) {
1398 bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf);
1399 print_fn_code(jit.prg_buf, jit.size_prg);
1400 }
1401 bpf_jit_binary_lock_ro(header);
1402 fp->bpf_func = (void *) jit.prg_buf;
1403 fp->jited = 1;
1404 fp->jited_len = jit.size;
1405 free_addrs:
1406 kfree(jit.addrs);
1407 out:
1408 if (tmp_blinded)
1409 bpf_jit_prog_release_other(fp, fp == orig_fp ?
1410 tmp : orig_fp);
1411 return fp;
1412 }
Linux with added FPC-III support