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1/*
2 * BPF Jit compiler for s390.
3 *
4 * Minimum build requirements:
5 *
6 * - HAVE_MARCH_Z196_FEATURES: laal, laalg
7 * - HAVE_MARCH_Z10_FEATURES: msfi, cgrj, clgrj
8 * - HAVE_MARCH_Z9_109_FEATURES: alfi, llilf, clfi, oilf, nilf
9 * - PACK_STACK
10 * - 64BIT
11 *
12 * Copyright IBM Corp. 2012,2015
13 *
14 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
15 * Michael Holzheu <holzheu@linux.vnet.ibm.com>
16 */
17
18#define KMSG_COMPONENT "bpf_jit"
19#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
20
21#include <linux/netdevice.h>
22#include <linux/filter.h>
23#include <linux/init.h>
24#include <linux/bpf.h>
25#include <asm/cacheflush.h>
26#include <asm/dis.h>
27#include "bpf_jit.h"
28
29int bpf_jit_enable __read_mostly;
30
31struct bpf_jit {
32 u32 seen; /* Flags to remember seen eBPF instructions */
33 u32 seen_reg[16]; /* Array to remember which registers are used */
34 u32 *addrs; /* Array with relative instruction addresses */
35 u8 *prg_buf; /* Start of program */
36 int size; /* Size of program and literal pool */
37 int size_prg; /* Size of program */
38 int prg; /* Current position in program */
39 int lit_start; /* Start of literal pool */
40 int lit; /* Current position in literal pool */
41 int base_ip; /* Base address for literal pool */
42 int ret0_ip; /* Address of return 0 */
43 int exit_ip; /* Address of exit */
44 int tail_call_start; /* Tail call start offset */
45 int labels[1]; /* Labels for local jumps */
46};
47
48#define BPF_SIZE_MAX 0x7ffff /* Max size for program (20 bit signed displ) */
49
50#define SEEN_SKB 1 /* skb access */
51#define SEEN_MEM 2 /* use mem[] for temporary storage */
52#define SEEN_RET0 4 /* ret0_ip points to a valid return 0 */
53#define SEEN_LITERAL 8 /* code uses literals */
54#define SEEN_FUNC 16 /* calls C functions */
55#define SEEN_TAIL_CALL 32 /* code uses tail calls */
56#define SEEN_SKB_CHANGE 64 /* code changes skb data */
57#define SEEN_STACK (SEEN_FUNC | SEEN_MEM | SEEN_SKB)
58
59/*
60 * s390 registers
61 */
62#define REG_W0 (__MAX_BPF_REG+0) /* Work register 1 (even) */
63#define REG_W1 (__MAX_BPF_REG+1) /* Work register 2 (odd) */
64#define REG_SKB_DATA (__MAX_BPF_REG+2) /* SKB data register */
65#define REG_L (__MAX_BPF_REG+3) /* Literal pool register */
66#define REG_15 (__MAX_BPF_REG+4) /* Register 15 */
67#define REG_0 REG_W0 /* Register 0 */
68#define REG_1 REG_W1 /* Register 1 */
69#define REG_2 BPF_REG_1 /* Register 2 */
70#define REG_14 BPF_REG_0 /* Register 14 */
71
72/*
73 * Mapping of BPF registers to s390 registers
74 */
75static const int reg2hex[] = {
76 /* Return code */
77 [BPF_REG_0] = 14,
78 /* Function parameters */
79 [BPF_REG_1] = 2,
80 [BPF_REG_2] = 3,
81 [BPF_REG_3] = 4,
82 [BPF_REG_4] = 5,
83 [BPF_REG_5] = 6,
84 /* Call saved registers */
85 [BPF_REG_6] = 7,
86 [BPF_REG_7] = 8,
87 [BPF_REG_8] = 9,
88 [BPF_REG_9] = 10,
89 /* BPF stack pointer */
90 [BPF_REG_FP] = 13,
91 /* SKB data pointer */
92 [REG_SKB_DATA] = 12,
93 /* Work registers for s390x backend */
94 [REG_W0] = 0,
95 [REG_W1] = 1,
96 [REG_L] = 11,
97 [REG_15] = 15,
98};
99
100static inline u32 reg(u32 dst_reg, u32 src_reg)
101{
102 return reg2hex[dst_reg] << 4 | reg2hex[src_reg];
103}
104
105static inline u32 reg_high(u32 reg)
106{
107 return reg2hex[reg] << 4;
108}
109
110static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
111{
112 u32 r1 = reg2hex[b1];
113
114 if (!jit->seen_reg[r1] && r1 >= 6 && r1 <= 15)
115 jit->seen_reg[r1] = 1;
116}
117
118#define REG_SET_SEEN(b1) \
119({ \
120 reg_set_seen(jit, b1); \
121})
122
123#define REG_SEEN(b1) jit->seen_reg[reg2hex[(b1)]]
124
125/*
126 * EMIT macros for code generation
127 */
128
129#define _EMIT2(op) \
130({ \
131 if (jit->prg_buf) \
132 *(u16 *) (jit->prg_buf + jit->prg) = op; \
133 jit->prg += 2; \
134})
135
136#define EMIT2(op, b1, b2) \
137({ \
138 _EMIT2(op | reg(b1, b2)); \
139 REG_SET_SEEN(b1); \
140 REG_SET_SEEN(b2); \
141})
142
143#define _EMIT4(op) \
144({ \
145 if (jit->prg_buf) \
146 *(u32 *) (jit->prg_buf + jit->prg) = op; \
147 jit->prg += 4; \
148})
149
150#define EMIT4(op, b1, b2) \
151({ \
152 _EMIT4(op | reg(b1, b2)); \
153 REG_SET_SEEN(b1); \
154 REG_SET_SEEN(b2); \
155})
156
157#define EMIT4_RRF(op, b1, b2, b3) \
158({ \
159 _EMIT4(op | reg_high(b3) << 8 | reg(b1, b2)); \
160 REG_SET_SEEN(b1); \
161 REG_SET_SEEN(b2); \
162 REG_SET_SEEN(b3); \
163})
164
165#define _EMIT4_DISP(op, disp) \
166({ \
167 unsigned int __disp = (disp) & 0xfff; \
168 _EMIT4(op | __disp); \
169})
170
171#define EMIT4_DISP(op, b1, b2, disp) \
172({ \
173 _EMIT4_DISP(op | reg_high(b1) << 16 | \
174 reg_high(b2) << 8, disp); \
175 REG_SET_SEEN(b1); \
176 REG_SET_SEEN(b2); \
177})
178
179#define EMIT4_IMM(op, b1, imm) \
180({ \
181 unsigned int __imm = (imm) & 0xffff; \
182 _EMIT4(op | reg_high(b1) << 16 | __imm); \
183 REG_SET_SEEN(b1); \
184})
185
186#define EMIT4_PCREL(op, pcrel) \
187({ \
188 long __pcrel = ((pcrel) >> 1) & 0xffff; \
189 _EMIT4(op | __pcrel); \
190})
191
192#define _EMIT6(op1, op2) \
193({ \
194 if (jit->prg_buf) { \
195 *(u32 *) (jit->prg_buf + jit->prg) = op1; \
196 *(u16 *) (jit->prg_buf + jit->prg + 4) = op2; \
197 } \
198 jit->prg += 6; \
199})
200
201#define _EMIT6_DISP(op1, op2, disp) \
202({ \
203 unsigned int __disp = (disp) & 0xfff; \
204 _EMIT6(op1 | __disp, op2); \
205})
206
207#define _EMIT6_DISP_LH(op1, op2, disp) \
208({ \
209 u32 _disp = (u32) disp; \
210 unsigned int __disp_h = _disp & 0xff000; \
211 unsigned int __disp_l = _disp & 0x00fff; \
212 _EMIT6(op1 | __disp_l, op2 | __disp_h >> 4); \
213})
214
215#define EMIT6_DISP_LH(op1, op2, b1, b2, b3, disp) \
216({ \
217 _EMIT6_DISP_LH(op1 | reg(b1, b2) << 16 | \
218 reg_high(b3) << 8, op2, disp); \
219 REG_SET_SEEN(b1); \
220 REG_SET_SEEN(b2); \
221 REG_SET_SEEN(b3); \
222})
223
224#define EMIT6_PCREL_LABEL(op1, op2, b1, b2, label, mask) \
225({ \
226 int rel = (jit->labels[label] - jit->prg) >> 1; \
227 _EMIT6(op1 | reg(b1, b2) << 16 | (rel & 0xffff), \
228 op2 | mask << 12); \
229 REG_SET_SEEN(b1); \
230 REG_SET_SEEN(b2); \
231})
232
233#define EMIT6_PCREL_IMM_LABEL(op1, op2, b1, imm, label, mask) \
234({ \
235 int rel = (jit->labels[label] - jit->prg) >> 1; \
236 _EMIT6(op1 | (reg_high(b1) | mask) << 16 | \
237 (rel & 0xffff), op2 | (imm & 0xff) << 8); \
238 REG_SET_SEEN(b1); \
239 BUILD_BUG_ON(((unsigned long) imm) > 0xff); \
240})
241
242#define EMIT6_PCREL(op1, op2, b1, b2, i, off, mask) \
243({ \
244 /* Branch instruction needs 6 bytes */ \
245 int rel = (addrs[i + off + 1] - (addrs[i + 1] - 6)) / 2;\
246 _EMIT6(op1 | reg(b1, b2) << 16 | (rel & 0xffff), op2 | mask); \
247 REG_SET_SEEN(b1); \
248 REG_SET_SEEN(b2); \
249})
250
251#define _EMIT6_IMM(op, imm) \
252({ \
253 unsigned int __imm = (imm); \
254 _EMIT6(op | (__imm >> 16), __imm & 0xffff); \
255})
256
257#define EMIT6_IMM(op, b1, imm) \
258({ \
259 _EMIT6_IMM(op | reg_high(b1) << 16, imm); \
260 REG_SET_SEEN(b1); \
261})
262
263#define EMIT_CONST_U32(val) \
264({ \
265 unsigned int ret; \
266 ret = jit->lit - jit->base_ip; \
267 jit->seen |= SEEN_LITERAL; \
268 if (jit->prg_buf) \
269 *(u32 *) (jit->prg_buf + jit->lit) = (u32) val; \
270 jit->lit += 4; \
271 ret; \
272})
273
274#define EMIT_CONST_U64(val) \
275({ \
276 unsigned int ret; \
277 ret = jit->lit - jit->base_ip; \
278 jit->seen |= SEEN_LITERAL; \
279 if (jit->prg_buf) \
280 *(u64 *) (jit->prg_buf + jit->lit) = (u64) val; \
281 jit->lit += 8; \
282 ret; \
283})
284
285#define EMIT_ZERO(b1) \
286({ \
287 /* llgfr %dst,%dst (zero extend to 64 bit) */ \
288 EMIT4(0xb9160000, b1, b1); \
289 REG_SET_SEEN(b1); \
290})
291
292/*
293 * Fill whole space with illegal instructions
294 */
295static void jit_fill_hole(void *area, unsigned int size)
296{
297 memset(area, 0, size);
298}
299
300/*
301 * Save registers from "rs" (register start) to "re" (register end) on stack
302 */
303static void save_regs(struct bpf_jit *jit, u32 rs, u32 re)
304{
305 u32 off = STK_OFF_R6 + (rs - 6) * 8;
306
307 if (rs == re)
308 /* stg %rs,off(%r15) */
309 _EMIT6(0xe300f000 | rs << 20 | off, 0x0024);
310 else
311 /* stmg %rs,%re,off(%r15) */
312 _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0024, off);
313}
314
315/*
316 * Restore registers from "rs" (register start) to "re" (register end) on stack
317 */
318static void restore_regs(struct bpf_jit *jit, u32 rs, u32 re)
319{
320 u32 off = STK_OFF_R6 + (rs - 6) * 8;
321
322 if (jit->seen & SEEN_STACK)
323 off += STK_OFF;
324
325 if (rs == re)
326 /* lg %rs,off(%r15) */
327 _EMIT6(0xe300f000 | rs << 20 | off, 0x0004);
328 else
329 /* lmg %rs,%re,off(%r15) */
330 _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0004, off);
331}
332
333/*
334 * Return first seen register (from start)
335 */
336static int get_start(struct bpf_jit *jit, int start)
337{
338 int i;
339
340 for (i = start; i <= 15; i++) {
341 if (jit->seen_reg[i])
342 return i;
343 }
344 return 0;
345}
346
347/*
348 * Return last seen register (from start) (gap >= 2)
349 */
350static int get_end(struct bpf_jit *jit, int start)
351{
352 int i;
353
354 for (i = start; i < 15; i++) {
355 if (!jit->seen_reg[i] && !jit->seen_reg[i + 1])
356 return i - 1;
357 }
358 return jit->seen_reg[15] ? 15 : 14;
359}
360
361#define REGS_SAVE 1
362#define REGS_RESTORE 0
363/*
364 * Save and restore clobbered registers (6-15) on stack.
365 * We save/restore registers in chunks with gap >= 2 registers.
366 */
367static void save_restore_regs(struct bpf_jit *jit, int op)
368{
369
370 int re = 6, rs;
371
372 do {
373 rs = get_start(jit, re);
374 if (!rs)
375 break;
376 re = get_end(jit, rs + 1);
377 if (op == REGS_SAVE)
378 save_regs(jit, rs, re);
379 else
380 restore_regs(jit, rs, re);
381 re++;
382 } while (re <= 15);
383}
384
385/*
386 * For SKB access %b1 contains the SKB pointer. For "bpf_jit.S"
387 * we store the SKB header length on the stack and the SKB data
388 * pointer in REG_SKB_DATA.
389 */
390static void emit_load_skb_data_hlen(struct bpf_jit *jit)
391{
392 /* Header length: llgf %w1,<len>(%b1) */
393 EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_1,
394 offsetof(struct sk_buff, len));
395 /* s %w1,<data_len>(%b1) */
396 EMIT4_DISP(0x5b000000, REG_W1, BPF_REG_1,
397 offsetof(struct sk_buff, data_len));
398 /* stg %w1,ST_OFF_HLEN(%r0,%r15) */
399 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, REG_15, STK_OFF_HLEN);
400 /* lg %skb_data,data_off(%b1) */
401 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0,
402 BPF_REG_1, offsetof(struct sk_buff, data));
403}
404
405/*
406 * Emit function prologue
407 *
408 * Save registers and create stack frame if necessary.
409 * See stack frame layout desription in "bpf_jit.h"!
410 */
411static void bpf_jit_prologue(struct bpf_jit *jit)
412{
413 if (jit->seen & SEEN_TAIL_CALL) {
414 /* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */
415 _EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT);
416 } else {
417 /* j tail_call_start: NOP if no tail calls are used */
418 EMIT4_PCREL(0xa7f40000, 6);
419 _EMIT2(0);
420 }
421 /* Tail calls have to skip above initialization */
422 jit->tail_call_start = jit->prg;
423 /* Save registers */
424 save_restore_regs(jit, REGS_SAVE);
425 /* Setup literal pool */
426 if (jit->seen & SEEN_LITERAL) {
427 /* basr %r13,0 */
428 EMIT2(0x0d00, REG_L, REG_0);
429 jit->base_ip = jit->prg;
430 }
431 /* Setup stack and backchain */
432 if (jit->seen & SEEN_STACK) {
433 if (jit->seen & SEEN_FUNC)
434 /* lgr %w1,%r15 (backchain) */
435 EMIT4(0xb9040000, REG_W1, REG_15);
436 /* la %bfp,STK_160_UNUSED(%r15) (BPF frame pointer) */
437 EMIT4_DISP(0x41000000, BPF_REG_FP, REG_15, STK_160_UNUSED);
438 /* aghi %r15,-STK_OFF */
439 EMIT4_IMM(0xa70b0000, REG_15, -STK_OFF);
440 if (jit->seen & SEEN_FUNC)
441 /* stg %w1,152(%r15) (backchain) */
442 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0,
443 REG_15, 152);
444 }
445 if (jit->seen & SEEN_SKB)
446 emit_load_skb_data_hlen(jit);
447 if (jit->seen & SEEN_SKB_CHANGE)
448 /* stg %b1,ST_OFF_SKBP(%r0,%r15) */
449 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, REG_15,
450 STK_OFF_SKBP);
451}
452
453/*
454 * Function epilogue
455 */
456static void bpf_jit_epilogue(struct bpf_jit *jit)
457{
458 /* Return 0 */
459 if (jit->seen & SEEN_RET0) {
460 jit->ret0_ip = jit->prg;
461 /* lghi %b0,0 */
462 EMIT4_IMM(0xa7090000, BPF_REG_0, 0);
463 }
464 jit->exit_ip = jit->prg;
465 /* Load exit code: lgr %r2,%b0 */
466 EMIT4(0xb9040000, REG_2, BPF_REG_0);
467 /* Restore registers */
468 save_restore_regs(jit, REGS_RESTORE);
469 /* br %r14 */
470 _EMIT2(0x07fe);
471}
472
473/*
474 * Compile one eBPF instruction into s390x code
475 *
476 * NOTE: Use noinline because for gcov (-fprofile-arcs) gcc allocates a lot of
477 * stack space for the large switch statement.
478 */
479static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i)
480{
481 struct bpf_insn *insn = &fp->insnsi[i];
482 int jmp_off, last, insn_count = 1;
483 unsigned int func_addr, mask;
484 u32 dst_reg = insn->dst_reg;
485 u32 src_reg = insn->src_reg;
486 u32 *addrs = jit->addrs;
487 s32 imm = insn->imm;
488 s16 off = insn->off;
489
490 switch (insn->code) {
491 /*
492 * BPF_MOV
493 */
494 case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */
495 /* llgfr %dst,%src */
496 EMIT4(0xb9160000, dst_reg, src_reg);
497 break;
498 case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
499 /* lgr %dst,%src */
500 EMIT4(0xb9040000, dst_reg, src_reg);
501 break;
502 case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */
503 /* llilf %dst,imm */
504 EMIT6_IMM(0xc00f0000, dst_reg, imm);
505 break;
506 case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */
507 /* lgfi %dst,imm */
508 EMIT6_IMM(0xc0010000, dst_reg, imm);
509 break;
510 /*
511 * BPF_LD 64
512 */
513 case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
514 {
515 /* 16 byte instruction that uses two 'struct bpf_insn' */
516 u64 imm64;
517
518 imm64 = (u64)(u32) insn[0].imm | ((u64)(u32) insn[1].imm) << 32;
519 /* lg %dst,<d(imm)>(%l) */
520 EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, REG_0, REG_L,
521 EMIT_CONST_U64(imm64));
522 insn_count = 2;
523 break;
524 }
525 /*
526 * BPF_ADD
527 */
528 case BPF_ALU | BPF_ADD | BPF_X: /* dst = (u32) dst + (u32) src */
529 /* ar %dst,%src */
530 EMIT2(0x1a00, dst_reg, src_reg);
531 EMIT_ZERO(dst_reg);
532 break;
533 case BPF_ALU64 | BPF_ADD | BPF_X: /* dst = dst + src */
534 /* agr %dst,%src */
535 EMIT4(0xb9080000, dst_reg, src_reg);
536 break;
537 case BPF_ALU | BPF_ADD | BPF_K: /* dst = (u32) dst + (u32) imm */
538 if (!imm)
539 break;
540 /* alfi %dst,imm */
541 EMIT6_IMM(0xc20b0000, dst_reg, imm);
542 EMIT_ZERO(dst_reg);
543 break;
544 case BPF_ALU64 | BPF_ADD | BPF_K: /* dst = dst + imm */
545 if (!imm)
546 break;
547 /* agfi %dst,imm */
548 EMIT6_IMM(0xc2080000, dst_reg, imm);
549 break;
550 /*
551 * BPF_SUB
552 */
553 case BPF_ALU | BPF_SUB | BPF_X: /* dst = (u32) dst - (u32) src */
554 /* sr %dst,%src */
555 EMIT2(0x1b00, dst_reg, src_reg);
556 EMIT_ZERO(dst_reg);
557 break;
558 case BPF_ALU64 | BPF_SUB | BPF_X: /* dst = dst - src */
559 /* sgr %dst,%src */
560 EMIT4(0xb9090000, dst_reg, src_reg);
561 break;
562 case BPF_ALU | BPF_SUB | BPF_K: /* dst = (u32) dst - (u32) imm */
563 if (!imm)
564 break;
565 /* alfi %dst,-imm */
566 EMIT6_IMM(0xc20b0000, dst_reg, -imm);
567 EMIT_ZERO(dst_reg);
568 break;
569 case BPF_ALU64 | BPF_SUB | BPF_K: /* dst = dst - imm */
570 if (!imm)
571 break;
572 /* agfi %dst,-imm */
573 EMIT6_IMM(0xc2080000, dst_reg, -imm);
574 break;
575 /*
576 * BPF_MUL
577 */
578 case BPF_ALU | BPF_MUL | BPF_X: /* dst = (u32) dst * (u32) src */
579 /* msr %dst,%src */
580 EMIT4(0xb2520000, dst_reg, src_reg);
581 EMIT_ZERO(dst_reg);
582 break;
583 case BPF_ALU64 | BPF_MUL | BPF_X: /* dst = dst * src */
584 /* msgr %dst,%src */
585 EMIT4(0xb90c0000, dst_reg, src_reg);
586 break;
587 case BPF_ALU | BPF_MUL | BPF_K: /* dst = (u32) dst * (u32) imm */
588 if (imm == 1)
589 break;
590 /* msfi %r5,imm */
591 EMIT6_IMM(0xc2010000, dst_reg, imm);
592 EMIT_ZERO(dst_reg);
593 break;
594 case BPF_ALU64 | BPF_MUL | BPF_K: /* dst = dst * imm */
595 if (imm == 1)
596 break;
597 /* msgfi %dst,imm */
598 EMIT6_IMM(0xc2000000, dst_reg, imm);
599 break;
600 /*
601 * BPF_DIV / BPF_MOD
602 */
603 case BPF_ALU | BPF_DIV | BPF_X: /* dst = (u32) dst / (u32) src */
604 case BPF_ALU | BPF_MOD | BPF_X: /* dst = (u32) dst % (u32) src */
605 {
606 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
607
608 jit->seen |= SEEN_RET0;
609 /* ltr %src,%src (if src == 0 goto fail) */
610 EMIT2(0x1200, src_reg, src_reg);
611 /* jz <ret0> */
612 EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg);
613 /* lhi %w0,0 */
614 EMIT4_IMM(0xa7080000, REG_W0, 0);
615 /* lr %w1,%dst */
616 EMIT2(0x1800, REG_W1, dst_reg);
617 /* dlr %w0,%src */
618 EMIT4(0xb9970000, REG_W0, src_reg);
619 /* llgfr %dst,%rc */
620 EMIT4(0xb9160000, dst_reg, rc_reg);
621 break;
622 }
623 case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */
624 case BPF_ALU64 | BPF_MOD | BPF_X: /* dst = dst % src */
625 {
626 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
627
628 jit->seen |= SEEN_RET0;
629 /* ltgr %src,%src (if src == 0 goto fail) */
630 EMIT4(0xb9020000, src_reg, src_reg);
631 /* jz <ret0> */
632 EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg);
633 /* lghi %w0,0 */
634 EMIT4_IMM(0xa7090000, REG_W0, 0);
635 /* lgr %w1,%dst */
636 EMIT4(0xb9040000, REG_W1, dst_reg);
637 /* dlgr %w0,%dst */
638 EMIT4(0xb9870000, REG_W0, src_reg);
639 /* lgr %dst,%rc */
640 EMIT4(0xb9040000, dst_reg, rc_reg);
641 break;
642 }
643 case BPF_ALU | BPF_DIV | BPF_K: /* dst = (u32) dst / (u32) imm */
644 case BPF_ALU | BPF_MOD | BPF_K: /* dst = (u32) dst % (u32) imm */
645 {
646 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
647
648 if (imm == 1) {
649 if (BPF_OP(insn->code) == BPF_MOD)
650 /* lhgi %dst,0 */
651 EMIT4_IMM(0xa7090000, dst_reg, 0);
652 break;
653 }
654 /* lhi %w0,0 */
655 EMIT4_IMM(0xa7080000, REG_W0, 0);
656 /* lr %w1,%dst */
657 EMIT2(0x1800, REG_W1, dst_reg);
658 /* dl %w0,<d(imm)>(%l) */
659 EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0, REG_L,
660 EMIT_CONST_U32(imm));
661 /* llgfr %dst,%rc */
662 EMIT4(0xb9160000, dst_reg, rc_reg);
663 break;
664 }
665 case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */
666 case BPF_ALU64 | BPF_MOD | BPF_K: /* dst = dst % imm */
667 {
668 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
669
670 if (imm == 1) {
671 if (BPF_OP(insn->code) == BPF_MOD)
672 /* lhgi %dst,0 */
673 EMIT4_IMM(0xa7090000, dst_reg, 0);
674 break;
675 }
676 /* lghi %w0,0 */
677 EMIT4_IMM(0xa7090000, REG_W0, 0);
678 /* lgr %w1,%dst */
679 EMIT4(0xb9040000, REG_W1, dst_reg);
680 /* dlg %w0,<d(imm)>(%l) */
681 EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0, REG_L,
682 EMIT_CONST_U64(imm));
683 /* lgr %dst,%rc */
684 EMIT4(0xb9040000, dst_reg, rc_reg);
685 break;
686 }
687 /*
688 * BPF_AND
689 */
690 case BPF_ALU | BPF_AND | BPF_X: /* dst = (u32) dst & (u32) src */
691 /* nr %dst,%src */
692 EMIT2(0x1400, dst_reg, src_reg);
693 EMIT_ZERO(dst_reg);
694 break;
695 case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
696 /* ngr %dst,%src */
697 EMIT4(0xb9800000, dst_reg, src_reg);
698 break;
699 case BPF_ALU | BPF_AND | BPF_K: /* dst = (u32) dst & (u32) imm */
700 /* nilf %dst,imm */
701 EMIT6_IMM(0xc00b0000, dst_reg, imm);
702 EMIT_ZERO(dst_reg);
703 break;
704 case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
705 /* ng %dst,<d(imm)>(%l) */
706 EMIT6_DISP_LH(0xe3000000, 0x0080, dst_reg, REG_0, REG_L,
707 EMIT_CONST_U64(imm));
708 break;
709 /*
710 * BPF_OR
711 */
712 case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
713 /* or %dst,%src */
714 EMIT2(0x1600, dst_reg, src_reg);
715 EMIT_ZERO(dst_reg);
716 break;
717 case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
718 /* ogr %dst,%src */
719 EMIT4(0xb9810000, dst_reg, src_reg);
720 break;
721 case BPF_ALU | BPF_OR | BPF_K: /* dst = (u32) dst | (u32) imm */
722 /* oilf %dst,imm */
723 EMIT6_IMM(0xc00d0000, dst_reg, imm);
724 EMIT_ZERO(dst_reg);
725 break;
726 case BPF_ALU64 | BPF_OR | BPF_K: /* dst = dst | imm */
727 /* og %dst,<d(imm)>(%l) */
728 EMIT6_DISP_LH(0xe3000000, 0x0081, dst_reg, REG_0, REG_L,
729 EMIT_CONST_U64(imm));
730 break;
731 /*
732 * BPF_XOR
733 */
734 case BPF_ALU | BPF_XOR | BPF_X: /* dst = (u32) dst ^ (u32) src */
735 /* xr %dst,%src */
736 EMIT2(0x1700, dst_reg, src_reg);
737 EMIT_ZERO(dst_reg);
738 break;
739 case BPF_ALU64 | BPF_XOR | BPF_X: /* dst = dst ^ src */
740 /* xgr %dst,%src */
741 EMIT4(0xb9820000, dst_reg, src_reg);
742 break;
743 case BPF_ALU | BPF_XOR | BPF_K: /* dst = (u32) dst ^ (u32) imm */
744 if (!imm)
745 break;
746 /* xilf %dst,imm */
747 EMIT6_IMM(0xc0070000, dst_reg, imm);
748 EMIT_ZERO(dst_reg);
749 break;
750 case BPF_ALU64 | BPF_XOR | BPF_K: /* dst = dst ^ imm */
751 /* xg %dst,<d(imm)>(%l) */
752 EMIT6_DISP_LH(0xe3000000, 0x0082, dst_reg, REG_0, REG_L,
753 EMIT_CONST_U64(imm));
754 break;
755 /*
756 * BPF_LSH
757 */
758 case BPF_ALU | BPF_LSH | BPF_X: /* dst = (u32) dst << (u32) src */
759 /* sll %dst,0(%src) */
760 EMIT4_DISP(0x89000000, dst_reg, src_reg, 0);
761 EMIT_ZERO(dst_reg);
762 break;
763 case BPF_ALU64 | BPF_LSH | BPF_X: /* dst = dst << src */
764 /* sllg %dst,%dst,0(%src) */
765 EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, src_reg, 0);
766 break;
767 case BPF_ALU | BPF_LSH | BPF_K: /* dst = (u32) dst << (u32) imm */
768 if (imm == 0)
769 break;
770 /* sll %dst,imm(%r0) */
771 EMIT4_DISP(0x89000000, dst_reg, REG_0, imm);
772 EMIT_ZERO(dst_reg);
773 break;
774 case BPF_ALU64 | BPF_LSH | BPF_K: /* dst = dst << imm */
775 if (imm == 0)
776 break;
777 /* sllg %dst,%dst,imm(%r0) */
778 EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, REG_0, imm);
779 break;
780 /*
781 * BPF_RSH
782 */
783 case BPF_ALU | BPF_RSH | BPF_X: /* dst = (u32) dst >> (u32) src */
784 /* srl %dst,0(%src) */
785 EMIT4_DISP(0x88000000, dst_reg, src_reg, 0);
786 EMIT_ZERO(dst_reg);
787 break;
788 case BPF_ALU64 | BPF_RSH | BPF_X: /* dst = dst >> src */
789 /* srlg %dst,%dst,0(%src) */
790 EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, src_reg, 0);
791 break;
792 case BPF_ALU | BPF_RSH | BPF_K: /* dst = (u32) dst >> (u32) imm */
793 if (imm == 0)
794 break;
795 /* srl %dst,imm(%r0) */
796 EMIT4_DISP(0x88000000, dst_reg, REG_0, imm);
797 EMIT_ZERO(dst_reg);
798 break;
799 case BPF_ALU64 | BPF_RSH | BPF_K: /* dst = dst >> imm */
800 if (imm == 0)
801 break;
802 /* srlg %dst,%dst,imm(%r0) */
803 EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, REG_0, imm);
804 break;
805 /*
806 * BPF_ARSH
807 */
808 case BPF_ALU64 | BPF_ARSH | BPF_X: /* ((s64) dst) >>= src */
809 /* srag %dst,%dst,0(%src) */
810 EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, src_reg, 0);
811 break;
812 case BPF_ALU64 | BPF_ARSH | BPF_K: /* ((s64) dst) >>= imm */
813 if (imm == 0)
814 break;
815 /* srag %dst,%dst,imm(%r0) */
816 EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, REG_0, imm);
817 break;
818 /*
819 * BPF_NEG
820 */
821 case BPF_ALU | BPF_NEG: /* dst = (u32) -dst */
822 /* lcr %dst,%dst */
823 EMIT2(0x1300, dst_reg, dst_reg);
824 EMIT_ZERO(dst_reg);
825 break;
826 case BPF_ALU64 | BPF_NEG: /* dst = -dst */
827 /* lcgr %dst,%dst */
828 EMIT4(0xb9130000, dst_reg, dst_reg);
829 break;
830 /*
831 * BPF_FROM_BE/LE
832 */
833 case BPF_ALU | BPF_END | BPF_FROM_BE:
834 /* s390 is big endian, therefore only clear high order bytes */
835 switch (imm) {
836 case 16: /* dst = (u16) cpu_to_be16(dst) */
837 /* llghr %dst,%dst */
838 EMIT4(0xb9850000, dst_reg, dst_reg);
839 break;
840 case 32: /* dst = (u32) cpu_to_be32(dst) */
841 /* llgfr %dst,%dst */
842 EMIT4(0xb9160000, dst_reg, dst_reg);
843 break;
844 case 64: /* dst = (u64) cpu_to_be64(dst) */
845 break;
846 }
847 break;
848 case BPF_ALU | BPF_END | BPF_FROM_LE:
849 switch (imm) {
850 case 16: /* dst = (u16) cpu_to_le16(dst) */
851 /* lrvr %dst,%dst */
852 EMIT4(0xb91f0000, dst_reg, dst_reg);
853 /* srl %dst,16(%r0) */
854 EMIT4_DISP(0x88000000, dst_reg, REG_0, 16);
855 /* llghr %dst,%dst */
856 EMIT4(0xb9850000, dst_reg, dst_reg);
857 break;
858 case 32: /* dst = (u32) cpu_to_le32(dst) */
859 /* lrvr %dst,%dst */
860 EMIT4(0xb91f0000, dst_reg, dst_reg);
861 /* llgfr %dst,%dst */
862 EMIT4(0xb9160000, dst_reg, dst_reg);
863 break;
864 case 64: /* dst = (u64) cpu_to_le64(dst) */
865 /* lrvgr %dst,%dst */
866 EMIT4(0xb90f0000, dst_reg, dst_reg);
867 break;
868 }
869 break;
870 /*
871 * BPF_ST(X)
872 */
873 case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src_reg */
874 /* stcy %src,off(%dst) */
875 EMIT6_DISP_LH(0xe3000000, 0x0072, src_reg, dst_reg, REG_0, off);
876 jit->seen |= SEEN_MEM;
877 break;
878 case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
879 /* sthy %src,off(%dst) */
880 EMIT6_DISP_LH(0xe3000000, 0x0070, src_reg, dst_reg, REG_0, off);
881 jit->seen |= SEEN_MEM;
882 break;
883 case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
884 /* sty %src,off(%dst) */
885 EMIT6_DISP_LH(0xe3000000, 0x0050, src_reg, dst_reg, REG_0, off);
886 jit->seen |= SEEN_MEM;
887 break;
888 case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
889 /* stg %src,off(%dst) */
890 EMIT6_DISP_LH(0xe3000000, 0x0024, src_reg, dst_reg, REG_0, off);
891 jit->seen |= SEEN_MEM;
892 break;
893 case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
894 /* lhi %w0,imm */
895 EMIT4_IMM(0xa7080000, REG_W0, (u8) imm);
896 /* stcy %w0,off(dst) */
897 EMIT6_DISP_LH(0xe3000000, 0x0072, REG_W0, dst_reg, REG_0, off);
898 jit->seen |= SEEN_MEM;
899 break;
900 case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
901 /* lhi %w0,imm */
902 EMIT4_IMM(0xa7080000, REG_W0, (u16) imm);
903 /* sthy %w0,off(dst) */
904 EMIT6_DISP_LH(0xe3000000, 0x0070, REG_W0, dst_reg, REG_0, off);
905 jit->seen |= SEEN_MEM;
906 break;
907 case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
908 /* llilf %w0,imm */
909 EMIT6_IMM(0xc00f0000, REG_W0, (u32) imm);
910 /* sty %w0,off(%dst) */
911 EMIT6_DISP_LH(0xe3000000, 0x0050, REG_W0, dst_reg, REG_0, off);
912 jit->seen |= SEEN_MEM;
913 break;
914 case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
915 /* lgfi %w0,imm */
916 EMIT6_IMM(0xc0010000, REG_W0, imm);
917 /* stg %w0,off(%dst) */
918 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W0, dst_reg, REG_0, off);
919 jit->seen |= SEEN_MEM;
920 break;
921 /*
922 * BPF_STX XADD (atomic_add)
923 */
924 case BPF_STX | BPF_XADD | BPF_W: /* *(u32 *)(dst + off) += src */
925 /* laal %w0,%src,off(%dst) */
926 EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W0, src_reg,
927 dst_reg, off);
928 jit->seen |= SEEN_MEM;
929 break;
930 case BPF_STX | BPF_XADD | BPF_DW: /* *(u64 *)(dst + off) += src */
931 /* laalg %w0,%src,off(%dst) */
932 EMIT6_DISP_LH(0xeb000000, 0x00ea, REG_W0, src_reg,
933 dst_reg, off);
934 jit->seen |= SEEN_MEM;
935 break;
936 /*
937 * BPF_LDX
938 */
939 case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */
940 /* llgc %dst,0(off,%src) */
941 EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off);
942 jit->seen |= SEEN_MEM;
943 break;
944 case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */
945 /* llgh %dst,0(off,%src) */
946 EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off);
947 jit->seen |= SEEN_MEM;
948 break;
949 case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */
950 /* llgf %dst,off(%src) */
951 jit->seen |= SEEN_MEM;
952 EMIT6_DISP_LH(0xe3000000, 0x0016, dst_reg, src_reg, REG_0, off);
953 break;
954 case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
955 /* lg %dst,0(off,%src) */
956 jit->seen |= SEEN_MEM;
957 EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, src_reg, REG_0, off);
958 break;
959 /*
960 * BPF_JMP / CALL
961 */
962 case BPF_JMP | BPF_CALL:
963 {
964 /*
965 * b0 = (__bpf_call_base + imm)(b1, b2, b3, b4, b5)
966 */
967 const u64 func = (u64)__bpf_call_base + imm;
968
969 REG_SET_SEEN(BPF_REG_5);
970 jit->seen |= SEEN_FUNC;
971 /* lg %w1,<d(imm)>(%l) */
972 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_W1, REG_0, REG_L,
973 EMIT_CONST_U64(func));
974 /* basr %r14,%w1 */
975 EMIT2(0x0d00, REG_14, REG_W1);
976 /* lgr %b0,%r2: load return value into %b0 */
977 EMIT4(0xb9040000, BPF_REG_0, REG_2);
978 if (bpf_helper_changes_skb_data((void *)func)) {
979 jit->seen |= SEEN_SKB_CHANGE;
980 /* lg %b1,ST_OFF_SKBP(%r15) */
981 EMIT6_DISP_LH(0xe3000000, 0x0004, BPF_REG_1, REG_0,
982 REG_15, STK_OFF_SKBP);
983 emit_load_skb_data_hlen(jit);
984 }
985 break;
986 }
987 case BPF_JMP | BPF_CALL | BPF_X:
988 /*
989 * Implicit input:
990 * B1: pointer to ctx
991 * B2: pointer to bpf_array
992 * B3: index in bpf_array
993 */
994 jit->seen |= SEEN_TAIL_CALL;
995
996 /*
997 * if (index >= array->map.max_entries)
998 * goto out;
999 */
1000
1001 /* llgf %w1,map.max_entries(%b2) */
1002 EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_2,
1003 offsetof(struct bpf_array, map.max_entries));
1004 /* clgrj %b3,%w1,0xa,label0: if %b3 >= %w1 goto out */
1005 EMIT6_PCREL_LABEL(0xec000000, 0x0065, BPF_REG_3,
1006 REG_W1, 0, 0xa);
1007
1008 /*
1009 * if (tail_call_cnt++ > MAX_TAIL_CALL_CNT)
1010 * goto out;
1011 */
1012
1013 if (jit->seen & SEEN_STACK)
1014 off = STK_OFF_TCCNT + STK_OFF;
1015 else
1016 off = STK_OFF_TCCNT;
1017 /* lhi %w0,1 */
1018 EMIT4_IMM(0xa7080000, REG_W0, 1);
1019 /* laal %w1,%w0,off(%r15) */
1020 EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, REG_15, off);
1021 /* clij %w1,MAX_TAIL_CALL_CNT,0x2,label0 */
1022 EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007f, REG_W1,
1023 MAX_TAIL_CALL_CNT, 0, 0x2);
1024
1025 /*
1026 * prog = array->ptrs[index];
1027 * if (prog == NULL)
1028 * goto out;
1029 */
1030
1031 /* sllg %r1,%b3,3: %r1 = index * 8 */
1032 EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, BPF_REG_3, REG_0, 3);
1033 /* lg %r1,prog(%b2,%r1) */
1034 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, BPF_REG_2,
1035 REG_1, offsetof(struct bpf_array, ptrs));
1036 /* clgij %r1,0,0x8,label0 */
1037 EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007d, REG_1, 0, 0, 0x8);
1038
1039 /*
1040 * Restore registers before calling function
1041 */
1042 save_restore_regs(jit, REGS_RESTORE);
1043
1044 /*
1045 * goto *(prog->bpf_func + tail_call_start);
1046 */
1047
1048 /* lg %r1,bpf_func(%r1) */
1049 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, REG_1, REG_0,
1050 offsetof(struct bpf_prog, bpf_func));
1051 /* bc 0xf,tail_call_start(%r1) */
1052 _EMIT4(0x47f01000 + jit->tail_call_start);
1053 /* out: */
1054 jit->labels[0] = jit->prg;
1055 break;
1056 case BPF_JMP | BPF_EXIT: /* return b0 */
1057 last = (i == fp->len - 1) ? 1 : 0;
1058 if (last && !(jit->seen & SEEN_RET0))
1059 break;
1060 /* j <exit> */
1061 EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);
1062 break;
1063 /*
1064 * Branch relative (number of skipped instructions) to offset on
1065 * condition.
1066 *
1067 * Condition code to mask mapping:
1068 *
1069 * CC | Description | Mask
1070 * ------------------------------
1071 * 0 | Operands equal | 8
1072 * 1 | First operand low | 4
1073 * 2 | First operand high | 2
1074 * 3 | Unused | 1
1075 *
1076 * For s390x relative branches: ip = ip + off_bytes
1077 * For BPF relative branches: insn = insn + off_insns + 1
1078 *
1079 * For example for s390x with offset 0 we jump to the branch
1080 * instruction itself (loop) and for BPF with offset 0 we
1081 * branch to the instruction behind the branch.
1082 */
1083 case BPF_JMP | BPF_JA: /* if (true) */
1084 mask = 0xf000; /* j */
1085 goto branch_oc;
1086 case BPF_JMP | BPF_JSGT | BPF_K: /* ((s64) dst > (s64) imm) */
1087 mask = 0x2000; /* jh */
1088 goto branch_ks;
1089 case BPF_JMP | BPF_JSGE | BPF_K: /* ((s64) dst >= (s64) imm) */
1090 mask = 0xa000; /* jhe */
1091 goto branch_ks;
1092 case BPF_JMP | BPF_JGT | BPF_K: /* (dst_reg > imm) */
1093 mask = 0x2000; /* jh */
1094 goto branch_ku;
1095 case BPF_JMP | BPF_JGE | BPF_K: /* (dst_reg >= imm) */
1096 mask = 0xa000; /* jhe */
1097 goto branch_ku;
1098 case BPF_JMP | BPF_JNE | BPF_K: /* (dst_reg != imm) */
1099 mask = 0x7000; /* jne */
1100 goto branch_ku;
1101 case BPF_JMP | BPF_JEQ | BPF_K: /* (dst_reg == imm) */
1102 mask = 0x8000; /* je */
1103 goto branch_ku;
1104 case BPF_JMP | BPF_JSET | BPF_K: /* (dst_reg & imm) */
1105 mask = 0x7000; /* jnz */
1106 /* lgfi %w1,imm (load sign extend imm) */
1107 EMIT6_IMM(0xc0010000, REG_W1, imm);
1108 /* ngr %w1,%dst */
1109 EMIT4(0xb9800000, REG_W1, dst_reg);
1110 goto branch_oc;
1111
1112 case BPF_JMP | BPF_JSGT | BPF_X: /* ((s64) dst > (s64) src) */
1113 mask = 0x2000; /* jh */
1114 goto branch_xs;
1115 case BPF_JMP | BPF_JSGE | BPF_X: /* ((s64) dst >= (s64) src) */
1116 mask = 0xa000; /* jhe */
1117 goto branch_xs;
1118 case BPF_JMP | BPF_JGT | BPF_X: /* (dst > src) */
1119 mask = 0x2000; /* jh */
1120 goto branch_xu;
1121 case BPF_JMP | BPF_JGE | BPF_X: /* (dst >= src) */
1122 mask = 0xa000; /* jhe */
1123 goto branch_xu;
1124 case BPF_JMP | BPF_JNE | BPF_X: /* (dst != src) */
1125 mask = 0x7000; /* jne */
1126 goto branch_xu;
1127 case BPF_JMP | BPF_JEQ | BPF_X: /* (dst == src) */
1128 mask = 0x8000; /* je */
1129 goto branch_xu;
1130 case BPF_JMP | BPF_JSET | BPF_X: /* (dst & src) */
1131 mask = 0x7000; /* jnz */
1132 /* ngrk %w1,%dst,%src */
1133 EMIT4_RRF(0xb9e40000, REG_W1, dst_reg, src_reg);
1134 goto branch_oc;
1135branch_ks:
1136 /* lgfi %w1,imm (load sign extend imm) */
1137 EMIT6_IMM(0xc0010000, REG_W1, imm);
1138 /* cgrj %dst,%w1,mask,off */
1139 EMIT6_PCREL(0xec000000, 0x0064, dst_reg, REG_W1, i, off, mask);
1140 break;
1141branch_ku:
1142 /* lgfi %w1,imm (load sign extend imm) */
1143 EMIT6_IMM(0xc0010000, REG_W1, imm);
1144 /* clgrj %dst,%w1,mask,off */
1145 EMIT6_PCREL(0xec000000, 0x0065, dst_reg, REG_W1, i, off, mask);
1146 break;
1147branch_xs:
1148 /* cgrj %dst,%src,mask,off */
1149 EMIT6_PCREL(0xec000000, 0x0064, dst_reg, src_reg, i, off, mask);
1150 break;
1151branch_xu:
1152 /* clgrj %dst,%src,mask,off */
1153 EMIT6_PCREL(0xec000000, 0x0065, dst_reg, src_reg, i, off, mask);
1154 break;
1155branch_oc:
1156 /* brc mask,jmp_off (branch instruction needs 4 bytes) */
1157 jmp_off = addrs[i + off + 1] - (addrs[i + 1] - 4);
1158 EMIT4_PCREL(0xa7040000 | mask << 8, jmp_off);
1159 break;
1160 /*
1161 * BPF_LD
1162 */
1163 case BPF_LD | BPF_ABS | BPF_B: /* b0 = *(u8 *) (skb->data+imm) */
1164 case BPF_LD | BPF_IND | BPF_B: /* b0 = *(u8 *) (skb->data+imm+src) */
1165 if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
1166 func_addr = __pa(sk_load_byte_pos);
1167 else
1168 func_addr = __pa(sk_load_byte);
1169 goto call_fn;
1170 case BPF_LD | BPF_ABS | BPF_H: /* b0 = *(u16 *) (skb->data+imm) */
1171 case BPF_LD | BPF_IND | BPF_H: /* b0 = *(u16 *) (skb->data+imm+src) */
1172 if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
1173 func_addr = __pa(sk_load_half_pos);
1174 else
1175 func_addr = __pa(sk_load_half);
1176 goto call_fn;
1177 case BPF_LD | BPF_ABS | BPF_W: /* b0 = *(u32 *) (skb->data+imm) */
1178 case BPF_LD | BPF_IND | BPF_W: /* b0 = *(u32 *) (skb->data+imm+src) */
1179 if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
1180 func_addr = __pa(sk_load_word_pos);
1181 else
1182 func_addr = __pa(sk_load_word);
1183 goto call_fn;
1184call_fn:
1185 jit->seen |= SEEN_SKB | SEEN_RET0 | SEEN_FUNC;
1186 REG_SET_SEEN(REG_14); /* Return address of possible func call */
1187
1188 /*
1189 * Implicit input:
1190 * BPF_REG_6 (R7) : skb pointer
1191 * REG_SKB_DATA (R12): skb data pointer
1192 *
1193 * Calculated input:
1194 * BPF_REG_2 (R3) : offset of byte(s) to fetch in skb
1195 * BPF_REG_5 (R6) : return address
1196 *
1197 * Output:
1198 * BPF_REG_0 (R14): data read from skb
1199 *
1200 * Scratch registers (BPF_REG_1-5)
1201 */
1202
1203 /* Call function: llilf %w1,func_addr */
1204 EMIT6_IMM(0xc00f0000, REG_W1, func_addr);
1205
1206 /* Offset: lgfi %b2,imm */
1207 EMIT6_IMM(0xc0010000, BPF_REG_2, imm);
1208 if (BPF_MODE(insn->code) == BPF_IND)
1209 /* agfr %b2,%src (%src is s32 here) */
1210 EMIT4(0xb9180000, BPF_REG_2, src_reg);
1211
1212 /* basr %b5,%w1 (%b5 is call saved) */
1213 EMIT2(0x0d00, BPF_REG_5, REG_W1);
1214
1215 /*
1216 * Note: For fast access we jump directly after the
1217 * jnz instruction from bpf_jit.S
1218 */
1219 /* jnz <ret0> */
1220 EMIT4_PCREL(0xa7740000, jit->ret0_ip - jit->prg);
1221 break;
1222 default: /* too complex, give up */
1223 pr_err("Unknown opcode %02x\n", insn->code);
1224 return -1;
1225 }
1226 return insn_count;
1227}
1228
1229/*
1230 * Compile eBPF program into s390x code
1231 */
1232static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp)
1233{
1234 int i, insn_count;
1235
1236 jit->lit = jit->lit_start;
1237 jit->prg = 0;
1238
1239 bpf_jit_prologue(jit);
1240 for (i = 0; i < fp->len; i += insn_count) {
1241 insn_count = bpf_jit_insn(jit, fp, i);
1242 if (insn_count < 0)
1243 return -1;
1244 jit->addrs[i + 1] = jit->prg; /* Next instruction address */
1245 }
1246 bpf_jit_epilogue(jit);
1247
1248 jit->lit_start = jit->prg;
1249 jit->size = jit->lit;
1250 jit->size_prg = jit->prg;
1251 return 0;
1252}
1253
1254/*
1255 * Classic BPF function stub. BPF programs will be converted into
1256 * eBPF and then bpf_int_jit_compile() will be called.
1257 */
1258void bpf_jit_compile(struct bpf_prog *fp)
1259{
1260}
1261
1262/*
1263 * Compile eBPF program "fp"
1264 */
1265void bpf_int_jit_compile(struct bpf_prog *fp)
1266{
1267 struct bpf_binary_header *header;
1268 struct bpf_jit jit;
1269 int pass;
1270
1271 if (!bpf_jit_enable)
1272 return;
1273 memset(&jit, 0, sizeof(jit));
1274 jit.addrs = kcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL);
1275 if (jit.addrs == NULL)
1276 return;
1277 /*
1278 * Three initial passes:
1279 * - 1/2: Determine clobbered registers
1280 * - 3: Calculate program size and addrs arrray
1281 */
1282 for (pass = 1; pass <= 3; pass++) {
1283 if (bpf_jit_prog(&jit, fp))
1284 goto free_addrs;
1285 }
1286 /*
1287 * Final pass: Allocate and generate program
1288 */
1289 if (jit.size >= BPF_SIZE_MAX)
1290 goto free_addrs;
1291 header = bpf_jit_binary_alloc(jit.size, &jit.prg_buf, 2, jit_fill_hole);
1292 if (!header)
1293 goto free_addrs;
1294 if (bpf_jit_prog(&jit, fp))
1295 goto free_addrs;
1296 if (bpf_jit_enable > 1) {
1297 bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf);
1298 if (jit.prg_buf)
1299 print_fn_code(jit.prg_buf, jit.size_prg);
1300 }
1301 if (jit.prg_buf) {
1302 set_memory_ro((unsigned long)header, header->pages);
1303 fp->bpf_func = (void *) jit.prg_buf;
1304 fp->jited = 1;
1305 }
1306free_addrs:
1307 kfree(jit.addrs);
1308}
1309
1310/*
1311 * Free eBPF program
1312 */
1313void bpf_jit_free(struct bpf_prog *fp)
1314{
1315 unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;
1316 struct bpf_binary_header *header = (void *)addr;
1317
1318 if (!fp->jited)
1319 goto free_filter;
1320
1321 set_memory_rw(addr, header->pages);
1322 bpf_jit_binary_free(header);
1323
1324free_filter:
1325 bpf_prog_unlock_free(fp);
1326}
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
33struct 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_MEM (1 << 0) /* use mem[] for temporary storage */
55#define SEEN_RET0 (1 << 1) /* ret0_ip points to a valid return 0 */
56#define SEEN_LITERAL (1 << 2) /* code uses literals */
57#define SEEN_FUNC (1 << 3) /* calls C functions */
58#define SEEN_TAIL_CALL (1 << 4) /* code uses tail calls */
59#define SEEN_REG_AX (1 << 5) /* code uses constant blinding */
60#define SEEN_STACK (SEEN_FUNC | SEEN_MEM)
61
62/*
63 * s390 registers
64 */
65#define REG_W0 (MAX_BPF_JIT_REG + 0) /* Work register 1 (even) */
66#define REG_W1 (MAX_BPF_JIT_REG + 1) /* Work register 2 (odd) */
67#define REG_L (MAX_BPF_JIT_REG + 2) /* Literal pool register */
68#define REG_15 (MAX_BPF_JIT_REG + 3) /* Register 15 */
69#define REG_0 REG_W0 /* Register 0 */
70#define REG_1 REG_W1 /* Register 1 */
71#define REG_2 BPF_REG_1 /* Register 2 */
72#define REG_14 BPF_REG_0 /* Register 14 */
73
74/*
75 * Mapping of BPF registers to s390 registers
76 */
77static const int reg2hex[] = {
78 /* Return code */
79 [BPF_REG_0] = 14,
80 /* Function parameters */
81 [BPF_REG_1] = 2,
82 [BPF_REG_2] = 3,
83 [BPF_REG_3] = 4,
84 [BPF_REG_4] = 5,
85 [BPF_REG_5] = 6,
86 /* Call saved registers */
87 [BPF_REG_6] = 7,
88 [BPF_REG_7] = 8,
89 [BPF_REG_8] = 9,
90 [BPF_REG_9] = 10,
91 /* BPF stack pointer */
92 [BPF_REG_FP] = 13,
93 /* Register for blinding */
94 [BPF_REG_AX] = 12,
95 /* Work registers for s390x backend */
96 [REG_W0] = 0,
97 [REG_W1] = 1,
98 [REG_L] = 11,
99 [REG_15] = 15,
100};
101
102static inline u32 reg(u32 dst_reg, u32 src_reg)
103{
104 return reg2hex[dst_reg] << 4 | reg2hex[src_reg];
105}
106
107static inline u32 reg_high(u32 reg)
108{
109 return reg2hex[reg] << 4;
110}
111
112static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
113{
114 u32 r1 = reg2hex[b1];
115
116 if (!jit->seen_reg[r1] && r1 >= 6 && r1 <= 15)
117 jit->seen_reg[r1] = 1;
118}
119
120#define REG_SET_SEEN(b1) \
121({ \
122 reg_set_seen(jit, b1); \
123})
124
125#define REG_SEEN(b1) jit->seen_reg[reg2hex[(b1)]]
126
127/*
128 * EMIT macros for code generation
129 */
130
131#define _EMIT2(op) \
132({ \
133 if (jit->prg_buf) \
134 *(u16 *) (jit->prg_buf + jit->prg) = op; \
135 jit->prg += 2; \
136})
137
138#define EMIT2(op, b1, b2) \
139({ \
140 _EMIT2(op | reg(b1, b2)); \
141 REG_SET_SEEN(b1); \
142 REG_SET_SEEN(b2); \
143})
144
145#define _EMIT4(op) \
146({ \
147 if (jit->prg_buf) \
148 *(u32 *) (jit->prg_buf + jit->prg) = op; \
149 jit->prg += 4; \
150})
151
152#define EMIT4(op, b1, b2) \
153({ \
154 _EMIT4(op | reg(b1, b2)); \
155 REG_SET_SEEN(b1); \
156 REG_SET_SEEN(b2); \
157})
158
159#define EMIT4_RRF(op, b1, b2, b3) \
160({ \
161 _EMIT4(op | reg_high(b3) << 8 | reg(b1, b2)); \
162 REG_SET_SEEN(b1); \
163 REG_SET_SEEN(b2); \
164 REG_SET_SEEN(b3); \
165})
166
167#define _EMIT4_DISP(op, disp) \
168({ \
169 unsigned int __disp = (disp) & 0xfff; \
170 _EMIT4(op | __disp); \
171})
172
173#define EMIT4_DISP(op, b1, b2, disp) \
174({ \
175 _EMIT4_DISP(op | reg_high(b1) << 16 | \
176 reg_high(b2) << 8, disp); \
177 REG_SET_SEEN(b1); \
178 REG_SET_SEEN(b2); \
179})
180
181#define EMIT4_IMM(op, b1, imm) \
182({ \
183 unsigned int __imm = (imm) & 0xffff; \
184 _EMIT4(op | reg_high(b1) << 16 | __imm); \
185 REG_SET_SEEN(b1); \
186})
187
188#define EMIT4_PCREL(op, pcrel) \
189({ \
190 long __pcrel = ((pcrel) >> 1) & 0xffff; \
191 _EMIT4(op | __pcrel); \
192})
193
194#define _EMIT6(op1, op2) \
195({ \
196 if (jit->prg_buf) { \
197 *(u32 *) (jit->prg_buf + jit->prg) = op1; \
198 *(u16 *) (jit->prg_buf + jit->prg + 4) = op2; \
199 } \
200 jit->prg += 6; \
201})
202
203#define _EMIT6_DISP(op1, op2, disp) \
204({ \
205 unsigned int __disp = (disp) & 0xfff; \
206 _EMIT6(op1 | __disp, op2); \
207})
208
209#define _EMIT6_DISP_LH(op1, op2, disp) \
210({ \
211 u32 _disp = (u32) disp; \
212 unsigned int __disp_h = _disp & 0xff000; \
213 unsigned int __disp_l = _disp & 0x00fff; \
214 _EMIT6(op1 | __disp_l, op2 | __disp_h >> 4); \
215})
216
217#define EMIT6_DISP_LH(op1, op2, b1, b2, b3, disp) \
218({ \
219 _EMIT6_DISP_LH(op1 | reg(b1, b2) << 16 | \
220 reg_high(b3) << 8, op2, disp); \
221 REG_SET_SEEN(b1); \
222 REG_SET_SEEN(b2); \
223 REG_SET_SEEN(b3); \
224})
225
226#define EMIT6_PCREL_LABEL(op1, op2, b1, b2, label, mask) \
227({ \
228 int rel = (jit->labels[label] - jit->prg) >> 1; \
229 _EMIT6(op1 | reg(b1, b2) << 16 | (rel & 0xffff), \
230 op2 | mask << 12); \
231 REG_SET_SEEN(b1); \
232 REG_SET_SEEN(b2); \
233})
234
235#define EMIT6_PCREL_IMM_LABEL(op1, op2, b1, imm, label, mask) \
236({ \
237 int rel = (jit->labels[label] - jit->prg) >> 1; \
238 _EMIT6(op1 | (reg_high(b1) | mask) << 16 | \
239 (rel & 0xffff), op2 | (imm & 0xff) << 8); \
240 REG_SET_SEEN(b1); \
241 BUILD_BUG_ON(((unsigned long) imm) > 0xff); \
242})
243
244#define EMIT6_PCREL(op1, op2, b1, b2, i, off, mask) \
245({ \
246 /* Branch instruction needs 6 bytes */ \
247 int rel = (addrs[i + off + 1] - (addrs[i + 1] - 6)) / 2;\
248 _EMIT6(op1 | reg(b1, b2) << 16 | (rel & 0xffff), op2 | mask); \
249 REG_SET_SEEN(b1); \
250 REG_SET_SEEN(b2); \
251})
252
253#define EMIT6_PCREL_RILB(op, b, target) \
254({ \
255 int rel = (target - jit->prg) / 2; \
256 _EMIT6(op | reg_high(b) << 16 | rel >> 16, rel & 0xffff); \
257 REG_SET_SEEN(b); \
258})
259
260#define EMIT6_PCREL_RIL(op, target) \
261({ \
262 int rel = (target - jit->prg) / 2; \
263 _EMIT6(op | rel >> 16, rel & 0xffff); \
264})
265
266#define _EMIT6_IMM(op, imm) \
267({ \
268 unsigned int __imm = (imm); \
269 _EMIT6(op | (__imm >> 16), __imm & 0xffff); \
270})
271
272#define EMIT6_IMM(op, b1, imm) \
273({ \
274 _EMIT6_IMM(op | reg_high(b1) << 16, imm); \
275 REG_SET_SEEN(b1); \
276})
277
278#define EMIT_CONST_U32(val) \
279({ \
280 unsigned int ret; \
281 ret = jit->lit - jit->base_ip; \
282 jit->seen |= SEEN_LITERAL; \
283 if (jit->prg_buf) \
284 *(u32 *) (jit->prg_buf + jit->lit) = (u32) val; \
285 jit->lit += 4; \
286 ret; \
287})
288
289#define EMIT_CONST_U64(val) \
290({ \
291 unsigned int ret; \
292 ret = jit->lit - jit->base_ip; \
293 jit->seen |= SEEN_LITERAL; \
294 if (jit->prg_buf) \
295 *(u64 *) (jit->prg_buf + jit->lit) = (u64) val; \
296 jit->lit += 8; \
297 ret; \
298})
299
300#define EMIT_ZERO(b1) \
301({ \
302 if (!fp->aux->verifier_zext) { \
303 /* llgfr %dst,%dst (zero extend to 64 bit) */ \
304 EMIT4(0xb9160000, b1, b1); \
305 REG_SET_SEEN(b1); \
306 } \
307})
308
309/*
310 * Fill whole space with illegal instructions
311 */
312static void jit_fill_hole(void *area, unsigned int size)
313{
314 memset(area, 0, size);
315}
316
317/*
318 * Save registers from "rs" (register start) to "re" (register end) on stack
319 */
320static void save_regs(struct bpf_jit *jit, u32 rs, u32 re)
321{
322 u32 off = STK_OFF_R6 + (rs - 6) * 8;
323
324 if (rs == re)
325 /* stg %rs,off(%r15) */
326 _EMIT6(0xe300f000 | rs << 20 | off, 0x0024);
327 else
328 /* stmg %rs,%re,off(%r15) */
329 _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0024, off);
330}
331
332/*
333 * Restore registers from "rs" (register start) to "re" (register end) on stack
334 */
335static void restore_regs(struct bpf_jit *jit, u32 rs, u32 re, u32 stack_depth)
336{
337 u32 off = STK_OFF_R6 + (rs - 6) * 8;
338
339 if (jit->seen & SEEN_STACK)
340 off += STK_OFF + stack_depth;
341
342 if (rs == re)
343 /* lg %rs,off(%r15) */
344 _EMIT6(0xe300f000 | rs << 20 | off, 0x0004);
345 else
346 /* lmg %rs,%re,off(%r15) */
347 _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0004, off);
348}
349
350/*
351 * Return first seen register (from start)
352 */
353static int get_start(struct bpf_jit *jit, int start)
354{
355 int i;
356
357 for (i = start; i <= 15; i++) {
358 if (jit->seen_reg[i])
359 return i;
360 }
361 return 0;
362}
363
364/*
365 * Return last seen register (from start) (gap >= 2)
366 */
367static int get_end(struct bpf_jit *jit, int start)
368{
369 int i;
370
371 for (i = start; i < 15; i++) {
372 if (!jit->seen_reg[i] && !jit->seen_reg[i + 1])
373 return i - 1;
374 }
375 return jit->seen_reg[15] ? 15 : 14;
376}
377
378#define REGS_SAVE 1
379#define REGS_RESTORE 0
380/*
381 * Save and restore clobbered registers (6-15) on stack.
382 * We save/restore registers in chunks with gap >= 2 registers.
383 */
384static void save_restore_regs(struct bpf_jit *jit, int op, u32 stack_depth)
385{
386
387 int re = 6, rs;
388
389 do {
390 rs = get_start(jit, re);
391 if (!rs)
392 break;
393 re = get_end(jit, rs + 1);
394 if (op == REGS_SAVE)
395 save_regs(jit, rs, re);
396 else
397 restore_regs(jit, rs, re, stack_depth);
398 re++;
399 } while (re <= 15);
400}
401
402/*
403 * Emit function prologue
404 *
405 * Save registers and create stack frame if necessary.
406 * See stack frame layout desription in "bpf_jit.h"!
407 */
408static void bpf_jit_prologue(struct bpf_jit *jit, u32 stack_depth)
409{
410 if (jit->seen & SEEN_TAIL_CALL) {
411 /* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */
412 _EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT);
413 } else {
414 /* j tail_call_start: NOP if no tail calls are used */
415 EMIT4_PCREL(0xa7f40000, 6);
416 _EMIT2(0);
417 }
418 /* Tail calls have to skip above initialization */
419 jit->tail_call_start = jit->prg;
420 /* Save registers */
421 save_restore_regs(jit, REGS_SAVE, stack_depth);
422 /* Setup literal pool */
423 if (jit->seen & SEEN_LITERAL) {
424 /* basr %r13,0 */
425 EMIT2(0x0d00, REG_L, REG_0);
426 jit->base_ip = jit->prg;
427 }
428 /* Setup stack and backchain */
429 if (jit->seen & SEEN_STACK) {
430 if (jit->seen & SEEN_FUNC)
431 /* lgr %w1,%r15 (backchain) */
432 EMIT4(0xb9040000, REG_W1, REG_15);
433 /* la %bfp,STK_160_UNUSED(%r15) (BPF frame pointer) */
434 EMIT4_DISP(0x41000000, BPF_REG_FP, REG_15, STK_160_UNUSED);
435 /* aghi %r15,-STK_OFF */
436 EMIT4_IMM(0xa70b0000, REG_15, -(STK_OFF + stack_depth));
437 if (jit->seen & SEEN_FUNC)
438 /* stg %w1,152(%r15) (backchain) */
439 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0,
440 REG_15, 152);
441 }
442}
443
444/*
445 * Function epilogue
446 */
447static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
448{
449 /* Return 0 */
450 if (jit->seen & SEEN_RET0) {
451 jit->ret0_ip = jit->prg;
452 /* lghi %b0,0 */
453 EMIT4_IMM(0xa7090000, BPF_REG_0, 0);
454 }
455 jit->exit_ip = jit->prg;
456 /* Load exit code: lgr %r2,%b0 */
457 EMIT4(0xb9040000, REG_2, BPF_REG_0);
458 /* Restore registers */
459 save_restore_regs(jit, REGS_RESTORE, stack_depth);
460 if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable) {
461 jit->r14_thunk_ip = jit->prg;
462 /* Generate __s390_indirect_jump_r14 thunk */
463 if (test_facility(35)) {
464 /* exrl %r0,.+10 */
465 EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
466 } else {
467 /* larl %r1,.+14 */
468 EMIT6_PCREL_RILB(0xc0000000, REG_1, jit->prg + 14);
469 /* ex 0,0(%r1) */
470 EMIT4_DISP(0x44000000, REG_0, REG_1, 0);
471 }
472 /* j . */
473 EMIT4_PCREL(0xa7f40000, 0);
474 }
475 /* br %r14 */
476 _EMIT2(0x07fe);
477
478 if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable &&
479 (jit->seen & SEEN_FUNC)) {
480 jit->r1_thunk_ip = jit->prg;
481 /* Generate __s390_indirect_jump_r1 thunk */
482 if (test_facility(35)) {
483 /* exrl %r0,.+10 */
484 EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
485 /* j . */
486 EMIT4_PCREL(0xa7f40000, 0);
487 /* br %r1 */
488 _EMIT2(0x07f1);
489 } else {
490 /* ex 0,S390_lowcore.br_r1_tampoline */
491 EMIT4_DISP(0x44000000, REG_0, REG_0,
492 offsetof(struct lowcore, br_r1_trampoline));
493 /* j . */
494 EMIT4_PCREL(0xa7f40000, 0);
495 }
496 }
497}
498
499/*
500 * Compile one eBPF instruction into s390x code
501 *
502 * NOTE: Use noinline because for gcov (-fprofile-arcs) gcc allocates a lot of
503 * stack space for the large switch statement.
504 */
505static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
506 int i, bool extra_pass)
507{
508 struct bpf_insn *insn = &fp->insnsi[i];
509 int jmp_off, last, insn_count = 1;
510 u32 dst_reg = insn->dst_reg;
511 u32 src_reg = insn->src_reg;
512 u32 *addrs = jit->addrs;
513 s32 imm = insn->imm;
514 s16 off = insn->off;
515 unsigned int mask;
516
517 if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX)
518 jit->seen |= SEEN_REG_AX;
519 switch (insn->code) {
520 /*
521 * BPF_MOV
522 */
523 case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */
524 /* llgfr %dst,%src */
525 EMIT4(0xb9160000, dst_reg, src_reg);
526 if (insn_is_zext(&insn[1]))
527 insn_count = 2;
528 break;
529 case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
530 /* lgr %dst,%src */
531 EMIT4(0xb9040000, dst_reg, src_reg);
532 break;
533 case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */
534 /* llilf %dst,imm */
535 EMIT6_IMM(0xc00f0000, dst_reg, imm);
536 if (insn_is_zext(&insn[1]))
537 insn_count = 2;
538 break;
539 case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */
540 /* lgfi %dst,imm */
541 EMIT6_IMM(0xc0010000, dst_reg, imm);
542 break;
543 /*
544 * BPF_LD 64
545 */
546 case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
547 {
548 /* 16 byte instruction that uses two 'struct bpf_insn' */
549 u64 imm64;
550
551 imm64 = (u64)(u32) insn[0].imm | ((u64)(u32) insn[1].imm) << 32;
552 /* lg %dst,<d(imm)>(%l) */
553 EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, REG_0, REG_L,
554 EMIT_CONST_U64(imm64));
555 insn_count = 2;
556 break;
557 }
558 /*
559 * BPF_ADD
560 */
561 case BPF_ALU | BPF_ADD | BPF_X: /* dst = (u32) dst + (u32) src */
562 /* ar %dst,%src */
563 EMIT2(0x1a00, dst_reg, src_reg);
564 EMIT_ZERO(dst_reg);
565 break;
566 case BPF_ALU64 | BPF_ADD | BPF_X: /* dst = dst + src */
567 /* agr %dst,%src */
568 EMIT4(0xb9080000, dst_reg, src_reg);
569 break;
570 case BPF_ALU | BPF_ADD | BPF_K: /* dst = (u32) dst + (u32) imm */
571 if (!imm)
572 break;
573 /* alfi %dst,imm */
574 EMIT6_IMM(0xc20b0000, dst_reg, imm);
575 EMIT_ZERO(dst_reg);
576 break;
577 case BPF_ALU64 | BPF_ADD | BPF_K: /* dst = dst + imm */
578 if (!imm)
579 break;
580 /* agfi %dst,imm */
581 EMIT6_IMM(0xc2080000, dst_reg, imm);
582 break;
583 /*
584 * BPF_SUB
585 */
586 case BPF_ALU | BPF_SUB | BPF_X: /* dst = (u32) dst - (u32) src */
587 /* sr %dst,%src */
588 EMIT2(0x1b00, dst_reg, src_reg);
589 EMIT_ZERO(dst_reg);
590 break;
591 case BPF_ALU64 | BPF_SUB | BPF_X: /* dst = dst - src */
592 /* sgr %dst,%src */
593 EMIT4(0xb9090000, dst_reg, src_reg);
594 break;
595 case BPF_ALU | BPF_SUB | BPF_K: /* dst = (u32) dst - (u32) imm */
596 if (!imm)
597 break;
598 /* alfi %dst,-imm */
599 EMIT6_IMM(0xc20b0000, dst_reg, -imm);
600 EMIT_ZERO(dst_reg);
601 break;
602 case BPF_ALU64 | BPF_SUB | BPF_K: /* dst = dst - imm */
603 if (!imm)
604 break;
605 /* agfi %dst,-imm */
606 EMIT6_IMM(0xc2080000, dst_reg, -imm);
607 break;
608 /*
609 * BPF_MUL
610 */
611 case BPF_ALU | BPF_MUL | BPF_X: /* dst = (u32) dst * (u32) src */
612 /* msr %dst,%src */
613 EMIT4(0xb2520000, dst_reg, src_reg);
614 EMIT_ZERO(dst_reg);
615 break;
616 case BPF_ALU64 | BPF_MUL | BPF_X: /* dst = dst * src */
617 /* msgr %dst,%src */
618 EMIT4(0xb90c0000, dst_reg, src_reg);
619 break;
620 case BPF_ALU | BPF_MUL | BPF_K: /* dst = (u32) dst * (u32) imm */
621 if (imm == 1)
622 break;
623 /* msfi %r5,imm */
624 EMIT6_IMM(0xc2010000, dst_reg, imm);
625 EMIT_ZERO(dst_reg);
626 break;
627 case BPF_ALU64 | BPF_MUL | BPF_K: /* dst = dst * imm */
628 if (imm == 1)
629 break;
630 /* msgfi %dst,imm */
631 EMIT6_IMM(0xc2000000, dst_reg, imm);
632 break;
633 /*
634 * BPF_DIV / BPF_MOD
635 */
636 case BPF_ALU | BPF_DIV | BPF_X: /* dst = (u32) dst / (u32) src */
637 case BPF_ALU | BPF_MOD | BPF_X: /* dst = (u32) dst % (u32) src */
638 {
639 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
640
641 /* lhi %w0,0 */
642 EMIT4_IMM(0xa7080000, REG_W0, 0);
643 /* lr %w1,%dst */
644 EMIT2(0x1800, REG_W1, dst_reg);
645 /* dlr %w0,%src */
646 EMIT4(0xb9970000, REG_W0, src_reg);
647 /* llgfr %dst,%rc */
648 EMIT4(0xb9160000, dst_reg, rc_reg);
649 if (insn_is_zext(&insn[1]))
650 insn_count = 2;
651 break;
652 }
653 case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */
654 case BPF_ALU64 | BPF_MOD | BPF_X: /* dst = dst % src */
655 {
656 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
657
658 /* lghi %w0,0 */
659 EMIT4_IMM(0xa7090000, REG_W0, 0);
660 /* lgr %w1,%dst */
661 EMIT4(0xb9040000, REG_W1, dst_reg);
662 /* dlgr %w0,%dst */
663 EMIT4(0xb9870000, REG_W0, src_reg);
664 /* lgr %dst,%rc */
665 EMIT4(0xb9040000, dst_reg, rc_reg);
666 break;
667 }
668 case BPF_ALU | BPF_DIV | BPF_K: /* dst = (u32) dst / (u32) imm */
669 case BPF_ALU | BPF_MOD | BPF_K: /* dst = (u32) dst % (u32) imm */
670 {
671 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
672
673 if (imm == 1) {
674 if (BPF_OP(insn->code) == BPF_MOD)
675 /* lhgi %dst,0 */
676 EMIT4_IMM(0xa7090000, dst_reg, 0);
677 break;
678 }
679 /* lhi %w0,0 */
680 EMIT4_IMM(0xa7080000, REG_W0, 0);
681 /* lr %w1,%dst */
682 EMIT2(0x1800, REG_W1, dst_reg);
683 /* dl %w0,<d(imm)>(%l) */
684 EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0, REG_L,
685 EMIT_CONST_U32(imm));
686 /* llgfr %dst,%rc */
687 EMIT4(0xb9160000, dst_reg, rc_reg);
688 if (insn_is_zext(&insn[1]))
689 insn_count = 2;
690 break;
691 }
692 case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */
693 case BPF_ALU64 | BPF_MOD | BPF_K: /* dst = dst % 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 /* lghi %w0,0 */
704 EMIT4_IMM(0xa7090000, REG_W0, 0);
705 /* lgr %w1,%dst */
706 EMIT4(0xb9040000, REG_W1, dst_reg);
707 /* dlg %w0,<d(imm)>(%l) */
708 EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0, REG_L,
709 EMIT_CONST_U64(imm));
710 /* lgr %dst,%rc */
711 EMIT4(0xb9040000, dst_reg, rc_reg);
712 break;
713 }
714 /*
715 * BPF_AND
716 */
717 case BPF_ALU | BPF_AND | BPF_X: /* dst = (u32) dst & (u32) src */
718 /* nr %dst,%src */
719 EMIT2(0x1400, dst_reg, src_reg);
720 EMIT_ZERO(dst_reg);
721 break;
722 case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
723 /* ngr %dst,%src */
724 EMIT4(0xb9800000, dst_reg, src_reg);
725 break;
726 case BPF_ALU | BPF_AND | BPF_K: /* dst = (u32) dst & (u32) imm */
727 /* nilf %dst,imm */
728 EMIT6_IMM(0xc00b0000, dst_reg, imm);
729 EMIT_ZERO(dst_reg);
730 break;
731 case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
732 /* ng %dst,<d(imm)>(%l) */
733 EMIT6_DISP_LH(0xe3000000, 0x0080, dst_reg, REG_0, REG_L,
734 EMIT_CONST_U64(imm));
735 break;
736 /*
737 * BPF_OR
738 */
739 case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
740 /* or %dst,%src */
741 EMIT2(0x1600, dst_reg, src_reg);
742 EMIT_ZERO(dst_reg);
743 break;
744 case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
745 /* ogr %dst,%src */
746 EMIT4(0xb9810000, dst_reg, src_reg);
747 break;
748 case BPF_ALU | BPF_OR | BPF_K: /* dst = (u32) dst | (u32) imm */
749 /* oilf %dst,imm */
750 EMIT6_IMM(0xc00d0000, dst_reg, imm);
751 EMIT_ZERO(dst_reg);
752 break;
753 case BPF_ALU64 | BPF_OR | BPF_K: /* dst = dst | imm */
754 /* og %dst,<d(imm)>(%l) */
755 EMIT6_DISP_LH(0xe3000000, 0x0081, dst_reg, REG_0, REG_L,
756 EMIT_CONST_U64(imm));
757 break;
758 /*
759 * BPF_XOR
760 */
761 case BPF_ALU | BPF_XOR | BPF_X: /* dst = (u32) dst ^ (u32) src */
762 /* xr %dst,%src */
763 EMIT2(0x1700, dst_reg, src_reg);
764 EMIT_ZERO(dst_reg);
765 break;
766 case BPF_ALU64 | BPF_XOR | BPF_X: /* dst = dst ^ src */
767 /* xgr %dst,%src */
768 EMIT4(0xb9820000, dst_reg, src_reg);
769 break;
770 case BPF_ALU | BPF_XOR | BPF_K: /* dst = (u32) dst ^ (u32) imm */
771 if (!imm)
772 break;
773 /* xilf %dst,imm */
774 EMIT6_IMM(0xc0070000, dst_reg, imm);
775 EMIT_ZERO(dst_reg);
776 break;
777 case BPF_ALU64 | BPF_XOR | BPF_K: /* dst = dst ^ imm */
778 /* xg %dst,<d(imm)>(%l) */
779 EMIT6_DISP_LH(0xe3000000, 0x0082, dst_reg, REG_0, REG_L,
780 EMIT_CONST_U64(imm));
781 break;
782 /*
783 * BPF_LSH
784 */
785 case BPF_ALU | BPF_LSH | BPF_X: /* dst = (u32) dst << (u32) src */
786 /* sll %dst,0(%src) */
787 EMIT4_DISP(0x89000000, dst_reg, src_reg, 0);
788 EMIT_ZERO(dst_reg);
789 break;
790 case BPF_ALU64 | BPF_LSH | BPF_X: /* dst = dst << src */
791 /* sllg %dst,%dst,0(%src) */
792 EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, src_reg, 0);
793 break;
794 case BPF_ALU | BPF_LSH | BPF_K: /* dst = (u32) dst << (u32) imm */
795 if (imm == 0)
796 break;
797 /* sll %dst,imm(%r0) */
798 EMIT4_DISP(0x89000000, dst_reg, REG_0, imm);
799 EMIT_ZERO(dst_reg);
800 break;
801 case BPF_ALU64 | BPF_LSH | BPF_K: /* dst = dst << imm */
802 if (imm == 0)
803 break;
804 /* sllg %dst,%dst,imm(%r0) */
805 EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, REG_0, imm);
806 break;
807 /*
808 * BPF_RSH
809 */
810 case BPF_ALU | BPF_RSH | BPF_X: /* dst = (u32) dst >> (u32) src */
811 /* srl %dst,0(%src) */
812 EMIT4_DISP(0x88000000, dst_reg, src_reg, 0);
813 EMIT_ZERO(dst_reg);
814 break;
815 case BPF_ALU64 | BPF_RSH | BPF_X: /* dst = dst >> src */
816 /* srlg %dst,%dst,0(%src) */
817 EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, src_reg, 0);
818 break;
819 case BPF_ALU | BPF_RSH | BPF_K: /* dst = (u32) dst >> (u32) imm */
820 if (imm == 0)
821 break;
822 /* srl %dst,imm(%r0) */
823 EMIT4_DISP(0x88000000, dst_reg, REG_0, imm);
824 EMIT_ZERO(dst_reg);
825 break;
826 case BPF_ALU64 | BPF_RSH | BPF_K: /* dst = dst >> imm */
827 if (imm == 0)
828 break;
829 /* srlg %dst,%dst,imm(%r0) */
830 EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, REG_0, imm);
831 break;
832 /*
833 * BPF_ARSH
834 */
835 case BPF_ALU | BPF_ARSH | BPF_X: /* ((s32) dst) >>= src */
836 /* sra %dst,%dst,0(%src) */
837 EMIT4_DISP(0x8a000000, dst_reg, src_reg, 0);
838 EMIT_ZERO(dst_reg);
839 break;
840 case BPF_ALU64 | BPF_ARSH | BPF_X: /* ((s64) dst) >>= src */
841 /* srag %dst,%dst,0(%src) */
842 EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, src_reg, 0);
843 break;
844 case BPF_ALU | BPF_ARSH | BPF_K: /* ((s32) dst >> imm */
845 if (imm == 0)
846 break;
847 /* sra %dst,imm(%r0) */
848 EMIT4_DISP(0x8a000000, dst_reg, REG_0, imm);
849 EMIT_ZERO(dst_reg);
850 break;
851 case BPF_ALU64 | BPF_ARSH | BPF_K: /* ((s64) dst) >>= imm */
852 if (imm == 0)
853 break;
854 /* srag %dst,%dst,imm(%r0) */
855 EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, REG_0, imm);
856 break;
857 /*
858 * BPF_NEG
859 */
860 case BPF_ALU | BPF_NEG: /* dst = (u32) -dst */
861 /* lcr %dst,%dst */
862 EMIT2(0x1300, dst_reg, dst_reg);
863 EMIT_ZERO(dst_reg);
864 break;
865 case BPF_ALU64 | BPF_NEG: /* dst = -dst */
866 /* lcgr %dst,%dst */
867 EMIT4(0xb9030000, dst_reg, dst_reg);
868 break;
869 /*
870 * BPF_FROM_BE/LE
871 */
872 case BPF_ALU | BPF_END | BPF_FROM_BE:
873 /* s390 is big endian, therefore only clear high order bytes */
874 switch (imm) {
875 case 16: /* dst = (u16) cpu_to_be16(dst) */
876 /* llghr %dst,%dst */
877 EMIT4(0xb9850000, dst_reg, dst_reg);
878 if (insn_is_zext(&insn[1]))
879 insn_count = 2;
880 break;
881 case 32: /* dst = (u32) cpu_to_be32(dst) */
882 if (!fp->aux->verifier_zext)
883 /* llgfr %dst,%dst */
884 EMIT4(0xb9160000, dst_reg, dst_reg);
885 break;
886 case 64: /* dst = (u64) cpu_to_be64(dst) */
887 break;
888 }
889 break;
890 case BPF_ALU | BPF_END | BPF_FROM_LE:
891 switch (imm) {
892 case 16: /* dst = (u16) cpu_to_le16(dst) */
893 /* lrvr %dst,%dst */
894 EMIT4(0xb91f0000, dst_reg, dst_reg);
895 /* srl %dst,16(%r0) */
896 EMIT4_DISP(0x88000000, dst_reg, REG_0, 16);
897 /* llghr %dst,%dst */
898 EMIT4(0xb9850000, dst_reg, dst_reg);
899 if (insn_is_zext(&insn[1]))
900 insn_count = 2;
901 break;
902 case 32: /* dst = (u32) cpu_to_le32(dst) */
903 /* lrvr %dst,%dst */
904 EMIT4(0xb91f0000, dst_reg, dst_reg);
905 if (!fp->aux->verifier_zext)
906 /* llgfr %dst,%dst */
907 EMIT4(0xb9160000, dst_reg, dst_reg);
908 break;
909 case 64: /* dst = (u64) cpu_to_le64(dst) */
910 /* lrvgr %dst,%dst */
911 EMIT4(0xb90f0000, dst_reg, dst_reg);
912 break;
913 }
914 break;
915 /*
916 * BPF_ST(X)
917 */
918 case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src_reg */
919 /* stcy %src,off(%dst) */
920 EMIT6_DISP_LH(0xe3000000, 0x0072, src_reg, dst_reg, REG_0, off);
921 jit->seen |= SEEN_MEM;
922 break;
923 case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
924 /* sthy %src,off(%dst) */
925 EMIT6_DISP_LH(0xe3000000, 0x0070, src_reg, dst_reg, REG_0, off);
926 jit->seen |= SEEN_MEM;
927 break;
928 case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
929 /* sty %src,off(%dst) */
930 EMIT6_DISP_LH(0xe3000000, 0x0050, src_reg, dst_reg, REG_0, off);
931 jit->seen |= SEEN_MEM;
932 break;
933 case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
934 /* stg %src,off(%dst) */
935 EMIT6_DISP_LH(0xe3000000, 0x0024, src_reg, dst_reg, REG_0, off);
936 jit->seen |= SEEN_MEM;
937 break;
938 case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
939 /* lhi %w0,imm */
940 EMIT4_IMM(0xa7080000, REG_W0, (u8) imm);
941 /* stcy %w0,off(dst) */
942 EMIT6_DISP_LH(0xe3000000, 0x0072, REG_W0, dst_reg, REG_0, off);
943 jit->seen |= SEEN_MEM;
944 break;
945 case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
946 /* lhi %w0,imm */
947 EMIT4_IMM(0xa7080000, REG_W0, (u16) imm);
948 /* sthy %w0,off(dst) */
949 EMIT6_DISP_LH(0xe3000000, 0x0070, REG_W0, dst_reg, REG_0, off);
950 jit->seen |= SEEN_MEM;
951 break;
952 case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
953 /* llilf %w0,imm */
954 EMIT6_IMM(0xc00f0000, REG_W0, (u32) imm);
955 /* sty %w0,off(%dst) */
956 EMIT6_DISP_LH(0xe3000000, 0x0050, REG_W0, dst_reg, REG_0, off);
957 jit->seen |= SEEN_MEM;
958 break;
959 case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
960 /* lgfi %w0,imm */
961 EMIT6_IMM(0xc0010000, REG_W0, imm);
962 /* stg %w0,off(%dst) */
963 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W0, dst_reg, REG_0, off);
964 jit->seen |= SEEN_MEM;
965 break;
966 /*
967 * BPF_STX XADD (atomic_add)
968 */
969 case BPF_STX | BPF_XADD | BPF_W: /* *(u32 *)(dst + off) += src */
970 /* laal %w0,%src,off(%dst) */
971 EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W0, src_reg,
972 dst_reg, off);
973 jit->seen |= SEEN_MEM;
974 break;
975 case BPF_STX | BPF_XADD | BPF_DW: /* *(u64 *)(dst + off) += src */
976 /* laalg %w0,%src,off(%dst) */
977 EMIT6_DISP_LH(0xeb000000, 0x00ea, REG_W0, src_reg,
978 dst_reg, off);
979 jit->seen |= SEEN_MEM;
980 break;
981 /*
982 * BPF_LDX
983 */
984 case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */
985 /* llgc %dst,0(off,%src) */
986 EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off);
987 jit->seen |= SEEN_MEM;
988 if (insn_is_zext(&insn[1]))
989 insn_count = 2;
990 break;
991 case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */
992 /* llgh %dst,0(off,%src) */
993 EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off);
994 jit->seen |= SEEN_MEM;
995 if (insn_is_zext(&insn[1]))
996 insn_count = 2;
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 if (insn_is_zext(&insn[1]))
1003 insn_count = 2;
1004 break;
1005 case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
1006 /* lg %dst,0(off,%src) */
1007 jit->seen |= SEEN_MEM;
1008 EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, src_reg, REG_0, off);
1009 break;
1010 /*
1011 * BPF_JMP / CALL
1012 */
1013 case BPF_JMP | BPF_CALL:
1014 {
1015 u64 func;
1016 bool func_addr_fixed;
1017 int ret;
1018
1019 ret = bpf_jit_get_func_addr(fp, insn, extra_pass,
1020 &func, &func_addr_fixed);
1021 if (ret < 0)
1022 return -1;
1023
1024 REG_SET_SEEN(BPF_REG_5);
1025 jit->seen |= SEEN_FUNC;
1026 /* lg %w1,<d(imm)>(%l) */
1027 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_W1, REG_0, REG_L,
1028 EMIT_CONST_U64(func));
1029 if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable) {
1030 /* brasl %r14,__s390_indirect_jump_r1 */
1031 EMIT6_PCREL_RILB(0xc0050000, REG_14, jit->r1_thunk_ip);
1032 } else {
1033 /* basr %r14,%w1 */
1034 EMIT2(0x0d00, REG_14, REG_W1);
1035 }
1036 /* lgr %b0,%r2: load return value into %b0 */
1037 EMIT4(0xb9040000, BPF_REG_0, REG_2);
1038 break;
1039 }
1040 case BPF_JMP | BPF_TAIL_CALL:
1041 /*
1042 * Implicit input:
1043 * B1: pointer to ctx
1044 * B2: pointer to bpf_array
1045 * B3: index in bpf_array
1046 */
1047 jit->seen |= SEEN_TAIL_CALL;
1048
1049 /*
1050 * if (index >= array->map.max_entries)
1051 * goto out;
1052 */
1053
1054 /* llgf %w1,map.max_entries(%b2) */
1055 EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_2,
1056 offsetof(struct bpf_array, map.max_entries));
1057 /* clrj %b3,%w1,0xa,label0: if (u32)%b3 >= (u32)%w1 goto out */
1058 EMIT6_PCREL_LABEL(0xec000000, 0x0077, BPF_REG_3,
1059 REG_W1, 0, 0xa);
1060
1061 /*
1062 * if (tail_call_cnt++ > MAX_TAIL_CALL_CNT)
1063 * goto out;
1064 */
1065
1066 if (jit->seen & SEEN_STACK)
1067 off = STK_OFF_TCCNT + STK_OFF + fp->aux->stack_depth;
1068 else
1069 off = STK_OFF_TCCNT;
1070 /* lhi %w0,1 */
1071 EMIT4_IMM(0xa7080000, REG_W0, 1);
1072 /* laal %w1,%w0,off(%r15) */
1073 EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, REG_15, off);
1074 /* clij %w1,MAX_TAIL_CALL_CNT,0x2,label0 */
1075 EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007f, REG_W1,
1076 MAX_TAIL_CALL_CNT, 0, 0x2);
1077
1078 /*
1079 * prog = array->ptrs[index];
1080 * if (prog == NULL)
1081 * goto out;
1082 */
1083
1084 /* llgfr %r1,%b3: %r1 = (u32) index */
1085 EMIT4(0xb9160000, REG_1, BPF_REG_3);
1086 /* sllg %r1,%r1,3: %r1 *= 8 */
1087 EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, REG_1, REG_0, 3);
1088 /* lg %r1,prog(%b2,%r1) */
1089 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, BPF_REG_2,
1090 REG_1, offsetof(struct bpf_array, ptrs));
1091 /* clgij %r1,0,0x8,label0 */
1092 EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007d, REG_1, 0, 0, 0x8);
1093
1094 /*
1095 * Restore registers before calling function
1096 */
1097 save_restore_regs(jit, REGS_RESTORE, fp->aux->stack_depth);
1098
1099 /*
1100 * goto *(prog->bpf_func + tail_call_start);
1101 */
1102
1103 /* lg %r1,bpf_func(%r1) */
1104 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, REG_1, REG_0,
1105 offsetof(struct bpf_prog, bpf_func));
1106 /* bc 0xf,tail_call_start(%r1) */
1107 _EMIT4(0x47f01000 + jit->tail_call_start);
1108 /* out: */
1109 jit->labels[0] = jit->prg;
1110 break;
1111 case BPF_JMP | BPF_EXIT: /* return b0 */
1112 last = (i == fp->len - 1) ? 1 : 0;
1113 if (last && !(jit->seen & SEEN_RET0))
1114 break;
1115 /* j <exit> */
1116 EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);
1117 break;
1118 /*
1119 * Branch relative (number of skipped instructions) to offset on
1120 * condition.
1121 *
1122 * Condition code to mask mapping:
1123 *
1124 * CC | Description | Mask
1125 * ------------------------------
1126 * 0 | Operands equal | 8
1127 * 1 | First operand low | 4
1128 * 2 | First operand high | 2
1129 * 3 | Unused | 1
1130 *
1131 * For s390x relative branches: ip = ip + off_bytes
1132 * For BPF relative branches: insn = insn + off_insns + 1
1133 *
1134 * For example for s390x with offset 0 we jump to the branch
1135 * instruction itself (loop) and for BPF with offset 0 we
1136 * branch to the instruction behind the branch.
1137 */
1138 case BPF_JMP | BPF_JA: /* if (true) */
1139 mask = 0xf000; /* j */
1140 goto branch_oc;
1141 case BPF_JMP | BPF_JSGT | BPF_K: /* ((s64) dst > (s64) imm) */
1142 case BPF_JMP32 | BPF_JSGT | BPF_K: /* ((s32) dst > (s32) imm) */
1143 mask = 0x2000; /* jh */
1144 goto branch_ks;
1145 case BPF_JMP | BPF_JSLT | BPF_K: /* ((s64) dst < (s64) imm) */
1146 case BPF_JMP32 | BPF_JSLT | BPF_K: /* ((s32) dst < (s32) imm) */
1147 mask = 0x4000; /* jl */
1148 goto branch_ks;
1149 case BPF_JMP | BPF_JSGE | BPF_K: /* ((s64) dst >= (s64) imm) */
1150 case BPF_JMP32 | BPF_JSGE | BPF_K: /* ((s32) dst >= (s32) imm) */
1151 mask = 0xa000; /* jhe */
1152 goto branch_ks;
1153 case BPF_JMP | BPF_JSLE | BPF_K: /* ((s64) dst <= (s64) imm) */
1154 case BPF_JMP32 | BPF_JSLE | BPF_K: /* ((s32) dst <= (s32) imm) */
1155 mask = 0xc000; /* jle */
1156 goto branch_ks;
1157 case BPF_JMP | BPF_JGT | BPF_K: /* (dst_reg > imm) */
1158 case BPF_JMP32 | BPF_JGT | BPF_K: /* ((u32) dst_reg > (u32) imm) */
1159 mask = 0x2000; /* jh */
1160 goto branch_ku;
1161 case BPF_JMP | BPF_JLT | BPF_K: /* (dst_reg < imm) */
1162 case BPF_JMP32 | BPF_JLT | BPF_K: /* ((u32) dst_reg < (u32) imm) */
1163 mask = 0x4000; /* jl */
1164 goto branch_ku;
1165 case BPF_JMP | BPF_JGE | BPF_K: /* (dst_reg >= imm) */
1166 case BPF_JMP32 | BPF_JGE | BPF_K: /* ((u32) dst_reg >= (u32) imm) */
1167 mask = 0xa000; /* jhe */
1168 goto branch_ku;
1169 case BPF_JMP | BPF_JLE | BPF_K: /* (dst_reg <= imm) */
1170 case BPF_JMP32 | BPF_JLE | BPF_K: /* ((u32) dst_reg <= (u32) imm) */
1171 mask = 0xc000; /* jle */
1172 goto branch_ku;
1173 case BPF_JMP | BPF_JNE | BPF_K: /* (dst_reg != imm) */
1174 case BPF_JMP32 | BPF_JNE | BPF_K: /* ((u32) dst_reg != (u32) imm) */
1175 mask = 0x7000; /* jne */
1176 goto branch_ku;
1177 case BPF_JMP | BPF_JEQ | BPF_K: /* (dst_reg == imm) */
1178 case BPF_JMP32 | BPF_JEQ | BPF_K: /* ((u32) dst_reg == (u32) imm) */
1179 mask = 0x8000; /* je */
1180 goto branch_ku;
1181 case BPF_JMP | BPF_JSET | BPF_K: /* (dst_reg & imm) */
1182 case BPF_JMP32 | BPF_JSET | BPF_K: /* ((u32) dst_reg & (u32) imm) */
1183 mask = 0x7000; /* jnz */
1184 if (BPF_CLASS(insn->code) == BPF_JMP32) {
1185 /* llilf %w1,imm (load zero extend imm) */
1186 EMIT6_IMM(0xc00f0000, REG_W1, imm);
1187 /* nr %w1,%dst */
1188 EMIT2(0x1400, REG_W1, dst_reg);
1189 } else {
1190 /* lgfi %w1,imm (load sign extend imm) */
1191 EMIT6_IMM(0xc0010000, REG_W1, imm);
1192 /* ngr %w1,%dst */
1193 EMIT4(0xb9800000, REG_W1, dst_reg);
1194 }
1195 goto branch_oc;
1196
1197 case BPF_JMP | BPF_JSGT | BPF_X: /* ((s64) dst > (s64) src) */
1198 case BPF_JMP32 | BPF_JSGT | BPF_X: /* ((s32) dst > (s32) src) */
1199 mask = 0x2000; /* jh */
1200 goto branch_xs;
1201 case BPF_JMP | BPF_JSLT | BPF_X: /* ((s64) dst < (s64) src) */
1202 case BPF_JMP32 | BPF_JSLT | BPF_X: /* ((s32) dst < (s32) src) */
1203 mask = 0x4000; /* jl */
1204 goto branch_xs;
1205 case BPF_JMP | BPF_JSGE | BPF_X: /* ((s64) dst >= (s64) src) */
1206 case BPF_JMP32 | BPF_JSGE | BPF_X: /* ((s32) dst >= (s32) src) */
1207 mask = 0xa000; /* jhe */
1208 goto branch_xs;
1209 case BPF_JMP | BPF_JSLE | BPF_X: /* ((s64) dst <= (s64) src) */
1210 case BPF_JMP32 | BPF_JSLE | BPF_X: /* ((s32) dst <= (s32) src) */
1211 mask = 0xc000; /* jle */
1212 goto branch_xs;
1213 case BPF_JMP | BPF_JGT | BPF_X: /* (dst > src) */
1214 case BPF_JMP32 | BPF_JGT | BPF_X: /* ((u32) dst > (u32) src) */
1215 mask = 0x2000; /* jh */
1216 goto branch_xu;
1217 case BPF_JMP | BPF_JLT | BPF_X: /* (dst < src) */
1218 case BPF_JMP32 | BPF_JLT | BPF_X: /* ((u32) dst < (u32) src) */
1219 mask = 0x4000; /* jl */
1220 goto branch_xu;
1221 case BPF_JMP | BPF_JGE | BPF_X: /* (dst >= src) */
1222 case BPF_JMP32 | BPF_JGE | BPF_X: /* ((u32) dst >= (u32) src) */
1223 mask = 0xa000; /* jhe */
1224 goto branch_xu;
1225 case BPF_JMP | BPF_JLE | BPF_X: /* (dst <= src) */
1226 case BPF_JMP32 | BPF_JLE | BPF_X: /* ((u32) dst <= (u32) src) */
1227 mask = 0xc000; /* jle */
1228 goto branch_xu;
1229 case BPF_JMP | BPF_JNE | BPF_X: /* (dst != src) */
1230 case BPF_JMP32 | BPF_JNE | BPF_X: /* ((u32) dst != (u32) src) */
1231 mask = 0x7000; /* jne */
1232 goto branch_xu;
1233 case BPF_JMP | BPF_JEQ | BPF_X: /* (dst == src) */
1234 case BPF_JMP32 | BPF_JEQ | BPF_X: /* ((u32) dst == (u32) src) */
1235 mask = 0x8000; /* je */
1236 goto branch_xu;
1237 case BPF_JMP | BPF_JSET | BPF_X: /* (dst & src) */
1238 case BPF_JMP32 | BPF_JSET | BPF_X: /* ((u32) dst & (u32) src) */
1239 {
1240 bool is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1241
1242 mask = 0x7000; /* jnz */
1243 /* nrk or ngrk %w1,%dst,%src */
1244 EMIT4_RRF((is_jmp32 ? 0xb9f40000 : 0xb9e40000),
1245 REG_W1, dst_reg, src_reg);
1246 goto branch_oc;
1247branch_ks:
1248 is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1249 /* lgfi %w1,imm (load sign extend imm) */
1250 EMIT6_IMM(0xc0010000, REG_W1, imm);
1251 /* crj or cgrj %dst,%w1,mask,off */
1252 EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0076 : 0x0064),
1253 dst_reg, REG_W1, i, off, mask);
1254 break;
1255branch_ku:
1256 is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1257 /* lgfi %w1,imm (load sign extend imm) */
1258 EMIT6_IMM(0xc0010000, REG_W1, imm);
1259 /* clrj or clgrj %dst,%w1,mask,off */
1260 EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0077 : 0x0065),
1261 dst_reg, REG_W1, i, off, mask);
1262 break;
1263branch_xs:
1264 is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1265 /* crj or cgrj %dst,%src,mask,off */
1266 EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0076 : 0x0064),
1267 dst_reg, src_reg, i, off, mask);
1268 break;
1269branch_xu:
1270 is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
1271 /* clrj or clgrj %dst,%src,mask,off */
1272 EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0077 : 0x0065),
1273 dst_reg, src_reg, i, off, mask);
1274 break;
1275branch_oc:
1276 /* brc mask,jmp_off (branch instruction needs 4 bytes) */
1277 jmp_off = addrs[i + off + 1] - (addrs[i + 1] - 4);
1278 EMIT4_PCREL(0xa7040000 | mask << 8, jmp_off);
1279 break;
1280 }
1281 default: /* too complex, give up */
1282 pr_err("Unknown opcode %02x\n", insn->code);
1283 return -1;
1284 }
1285 return insn_count;
1286}
1287
1288/*
1289 * Compile eBPF program into s390x code
1290 */
1291static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp,
1292 bool extra_pass)
1293{
1294 int i, insn_count;
1295
1296 jit->lit = jit->lit_start;
1297 jit->prg = 0;
1298
1299 bpf_jit_prologue(jit, fp->aux->stack_depth);
1300 for (i = 0; i < fp->len; i += insn_count) {
1301 insn_count = bpf_jit_insn(jit, fp, i, extra_pass);
1302 if (insn_count < 0)
1303 return -1;
1304 /* Next instruction address */
1305 jit->addrs[i + insn_count] = jit->prg;
1306 }
1307 bpf_jit_epilogue(jit, fp->aux->stack_depth);
1308
1309 jit->lit_start = jit->prg;
1310 jit->size = jit->lit;
1311 jit->size_prg = jit->prg;
1312 return 0;
1313}
1314
1315bool bpf_jit_needs_zext(void)
1316{
1317 return true;
1318}
1319
1320struct s390_jit_data {
1321 struct bpf_binary_header *header;
1322 struct bpf_jit ctx;
1323 int pass;
1324};
1325
1326/*
1327 * Compile eBPF program "fp"
1328 */
1329struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
1330{
1331 struct bpf_prog *tmp, *orig_fp = fp;
1332 struct bpf_binary_header *header;
1333 struct s390_jit_data *jit_data;
1334 bool tmp_blinded = false;
1335 bool extra_pass = false;
1336 struct bpf_jit jit;
1337 int pass;
1338
1339 if (!fp->jit_requested)
1340 return orig_fp;
1341
1342 tmp = bpf_jit_blind_constants(fp);
1343 /*
1344 * If blinding was requested and we failed during blinding,
1345 * we must fall back to the interpreter.
1346 */
1347 if (IS_ERR(tmp))
1348 return orig_fp;
1349 if (tmp != fp) {
1350 tmp_blinded = true;
1351 fp = tmp;
1352 }
1353
1354 jit_data = fp->aux->jit_data;
1355 if (!jit_data) {
1356 jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
1357 if (!jit_data) {
1358 fp = orig_fp;
1359 goto out;
1360 }
1361 fp->aux->jit_data = jit_data;
1362 }
1363 if (jit_data->ctx.addrs) {
1364 jit = jit_data->ctx;
1365 header = jit_data->header;
1366 extra_pass = true;
1367 pass = jit_data->pass + 1;
1368 goto skip_init_ctx;
1369 }
1370
1371 memset(&jit, 0, sizeof(jit));
1372 jit.addrs = kcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL);
1373 if (jit.addrs == NULL) {
1374 fp = orig_fp;
1375 goto out;
1376 }
1377 /*
1378 * Three initial passes:
1379 * - 1/2: Determine clobbered registers
1380 * - 3: Calculate program size and addrs arrray
1381 */
1382 for (pass = 1; pass <= 3; pass++) {
1383 if (bpf_jit_prog(&jit, fp, extra_pass)) {
1384 fp = orig_fp;
1385 goto free_addrs;
1386 }
1387 }
1388 /*
1389 * Final pass: Allocate and generate program
1390 */
1391 if (jit.size >= BPF_SIZE_MAX) {
1392 fp = orig_fp;
1393 goto free_addrs;
1394 }
1395
1396 header = bpf_jit_binary_alloc(jit.size, &jit.prg_buf, 2, jit_fill_hole);
1397 if (!header) {
1398 fp = orig_fp;
1399 goto free_addrs;
1400 }
1401skip_init_ctx:
1402 if (bpf_jit_prog(&jit, fp, extra_pass)) {
1403 bpf_jit_binary_free(header);
1404 fp = orig_fp;
1405 goto free_addrs;
1406 }
1407 if (bpf_jit_enable > 1) {
1408 bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf);
1409 print_fn_code(jit.prg_buf, jit.size_prg);
1410 }
1411 if (!fp->is_func || extra_pass) {
1412 bpf_jit_binary_lock_ro(header);
1413 } else {
1414 jit_data->header = header;
1415 jit_data->ctx = jit;
1416 jit_data->pass = pass;
1417 }
1418 fp->bpf_func = (void *) jit.prg_buf;
1419 fp->jited = 1;
1420 fp->jited_len = jit.size;
1421
1422 if (!fp->is_func || extra_pass) {
1423 bpf_prog_fill_jited_linfo(fp, jit.addrs + 1);
1424free_addrs:
1425 kfree(jit.addrs);
1426 kfree(jit_data);
1427 fp->aux->jit_data = NULL;
1428 }
1429out:
1430 if (tmp_blinded)
1431 bpf_jit_prog_release_other(fp, fp == orig_fp ?
1432 tmp : orig_fp);
1433 return fp;
1434}