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7
8#define pr_fmt(fmt) "bpf_jit: " fmt
9
10#include <linux/bitfield.h>
11#include <linux/bpf.h>
12#include <linux/filter.h>
13#include <linux/printk.h>
14#include <linux/slab.h>
15
16#include <asm/byteorder.h>
17#include <asm/cacheflush.h>
18#include <asm/debug-monitors.h>
19#include <asm/set_memory.h>
20
21#include "bpf_jit.h"
22
23#define TMP_REG_1 (MAX_BPF_JIT_REG + 0)
24#define TMP_REG_2 (MAX_BPF_JIT_REG + 1)
25#define TCALL_CNT (MAX_BPF_JIT_REG + 2)
26#define TMP_REG_3 (MAX_BPF_JIT_REG + 3)
27
28
29static const int bpf2a64[] = {
30
31 [BPF_REG_0] = A64_R(7),
32
33 [BPF_REG_1] = A64_R(0),
34 [BPF_REG_2] = A64_R(1),
35 [BPF_REG_3] = A64_R(2),
36 [BPF_REG_4] = A64_R(3),
37 [BPF_REG_5] = A64_R(4),
38
39 [BPF_REG_6] = A64_R(19),
40 [BPF_REG_7] = A64_R(20),
41 [BPF_REG_8] = A64_R(21),
42 [BPF_REG_9] = A64_R(22),
43
44 [BPF_REG_FP] = A64_R(25),
45
46 [TMP_REG_1] = A64_R(10),
47 [TMP_REG_2] = A64_R(11),
48 [TMP_REG_3] = A64_R(12),
49
50 [TCALL_CNT] = A64_R(26),
51
52 [BPF_REG_AX] = A64_R(9),
53};
54
55struct jit_ctx {
56 const struct bpf_prog *prog;
57 int idx;
58 int epilogue_offset;
59 int *offset;
60 int exentry_idx;
61 __le32 *image;
62 u32 stack_size;
63};
64
65static inline void emit(const u32 insn, struct jit_ctx *ctx)
66{
67 if (ctx->image != NULL)
68 ctx->image[ctx->idx] = cpu_to_le32(insn);
69
70 ctx->idx++;
71}
72
73static inline void emit_a64_mov_i(const int is64, const int reg,
74 const s32 val, struct jit_ctx *ctx)
75{
76 u16 hi = val >> 16;
77 u16 lo = val & 0xffff;
78
79 if (hi & 0x8000) {
80 if (hi == 0xffff) {
81 emit(A64_MOVN(is64, reg, (u16)~lo, 0), ctx);
82 } else {
83 emit(A64_MOVN(is64, reg, (u16)~hi, 16), ctx);
84 if (lo != 0xffff)
85 emit(A64_MOVK(is64, reg, lo, 0), ctx);
86 }
87 } else {
88 emit(A64_MOVZ(is64, reg, lo, 0), ctx);
89 if (hi)
90 emit(A64_MOVK(is64, reg, hi, 16), ctx);
91 }
92}
93
94static int i64_i16_blocks(const u64 val, bool inverse)
95{
96 return (((val >> 0) & 0xffff) != (inverse ? 0xffff : 0x0000)) +
97 (((val >> 16) & 0xffff) != (inverse ? 0xffff : 0x0000)) +
98 (((val >> 32) & 0xffff) != (inverse ? 0xffff : 0x0000)) +
99 (((val >> 48) & 0xffff) != (inverse ? 0xffff : 0x0000));
100}
101
102static inline void emit_a64_mov_i64(const int reg, const u64 val,
103 struct jit_ctx *ctx)
104{
105 u64 nrm_tmp = val, rev_tmp = ~val;
106 bool inverse;
107 int shift;
108
109 if (!(nrm_tmp >> 32))
110 return emit_a64_mov_i(0, reg, (u32)val, ctx);
111
112 inverse = i64_i16_blocks(nrm_tmp, true) < i64_i16_blocks(nrm_tmp, false);
113 shift = max(round_down((inverse ? (fls64(rev_tmp) - 1) :
114 (fls64(nrm_tmp) - 1)), 16), 0);
115 if (inverse)
116 emit(A64_MOVN(1, reg, (rev_tmp >> shift) & 0xffff, shift), ctx);
117 else
118 emit(A64_MOVZ(1, reg, (nrm_tmp >> shift) & 0xffff, shift), ctx);
119 shift -= 16;
120 while (shift >= 0) {
121 if (((nrm_tmp >> shift) & 0xffff) != (inverse ? 0xffff : 0x0000))
122 emit(A64_MOVK(1, reg, (nrm_tmp >> shift) & 0xffff, shift), ctx);
123 shift -= 16;
124 }
125}
126
127
128
129
130
131
132static inline void emit_addr_mov_i64(const int reg, const u64 val,
133 struct jit_ctx *ctx)
134{
135 u64 tmp = val;
136 int shift = 0;
137
138 emit(A64_MOVN(1, reg, ~tmp & 0xffff, shift), ctx);
139 while (shift < 32) {
140 tmp >>= 16;
141 shift += 16;
142 emit(A64_MOVK(1, reg, tmp & 0xffff, shift), ctx);
143 }
144}
145
146static inline int bpf2a64_offset(int bpf_insn, int off,
147 const struct jit_ctx *ctx)
148{
149
150 bpf_insn++;
151
152
153
154
155
156 return ctx->offset[bpf_insn + off] - (ctx->offset[bpf_insn] - 1);
157}
158
159static void jit_fill_hole(void *area, unsigned int size)
160{
161 __le32 *ptr;
162
163 for (ptr = area; size >= sizeof(u32); size -= sizeof(u32))
164 *ptr++ = cpu_to_le32(AARCH64_BREAK_FAULT);
165}
166
167static inline int epilogue_offset(const struct jit_ctx *ctx)
168{
169 int to = ctx->epilogue_offset;
170 int from = ctx->idx;
171
172 return to - from;
173}
174
175static bool is_addsub_imm(u32 imm)
176{
177
178 return !(imm & ~0xfff) || !(imm & ~0xfff000);
179}
180
181
182#define STACK_ALIGN(sz) (((sz) + 15) & ~15)
183
184
185#if IS_ENABLED(CONFIG_ARM64_BTI_KERNEL)
186#define PROLOGUE_OFFSET 8
187#else
188#define PROLOGUE_OFFSET 7
189#endif
190
191static int build_prologue(struct jit_ctx *ctx, bool ebpf_from_cbpf)
192{
193 const struct bpf_prog *prog = ctx->prog;
194 const u8 r6 = bpf2a64[BPF_REG_6];
195 const u8 r7 = bpf2a64[BPF_REG_7];
196 const u8 r8 = bpf2a64[BPF_REG_8];
197 const u8 r9 = bpf2a64[BPF_REG_9];
198 const u8 fp = bpf2a64[BPF_REG_FP];
199 const u8 tcc = bpf2a64[TCALL_CNT];
200 const int idx0 = ctx->idx;
201 int cur_offset;
202
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225
226
227 if (IS_ENABLED(CONFIG_ARM64_BTI_KERNEL))
228 emit(A64_BTI_C, ctx);
229
230
231 emit(A64_PUSH(A64_FP, A64_LR, A64_SP), ctx);
232 emit(A64_MOV(1, A64_FP, A64_SP), ctx);
233
234
235 emit(A64_PUSH(r6, r7, A64_SP), ctx);
236 emit(A64_PUSH(r8, r9, A64_SP), ctx);
237 emit(A64_PUSH(fp, tcc, A64_SP), ctx);
238
239
240 emit(A64_MOV(1, fp, A64_SP), ctx);
241
242 if (!ebpf_from_cbpf) {
243
244 emit(A64_MOVZ(1, tcc, 0, 0), ctx);
245
246 cur_offset = ctx->idx - idx0;
247 if (cur_offset != PROLOGUE_OFFSET) {
248 pr_err_once("PROLOGUE_OFFSET = %d, expected %d!\n",
249 cur_offset, PROLOGUE_OFFSET);
250 return -1;
251 }
252
253
254 if (IS_ENABLED(CONFIG_ARM64_BTI_KERNEL))
255 emit(A64_BTI_J, ctx);
256 }
257
258 ctx->stack_size = STACK_ALIGN(prog->aux->stack_depth);
259
260
261 emit(A64_SUB_I(1, A64_SP, A64_SP, ctx->stack_size), ctx);
262 return 0;
263}
264
265static int out_offset = -1;
266static int emit_bpf_tail_call(struct jit_ctx *ctx)
267{
268
269 const u8 r2 = bpf2a64[BPF_REG_2];
270 const u8 r3 = bpf2a64[BPF_REG_3];
271
272 const u8 tmp = bpf2a64[TMP_REG_1];
273 const u8 prg = bpf2a64[TMP_REG_2];
274 const u8 tcc = bpf2a64[TCALL_CNT];
275 const int idx0 = ctx->idx;
276#define cur_offset (ctx->idx - idx0)
277#define jmp_offset (out_offset - (cur_offset))
278 size_t off;
279
280
281
282
283 off = offsetof(struct bpf_array, map.max_entries);
284 emit_a64_mov_i64(tmp, off, ctx);
285 emit(A64_LDR32(tmp, r2, tmp), ctx);
286 emit(A64_MOV(0, r3, r3), ctx);
287 emit(A64_CMP(0, r3, tmp), ctx);
288 emit(A64_B_(A64_COND_CS, jmp_offset), ctx);
289
290
291
292
293
294 emit_a64_mov_i64(tmp, MAX_TAIL_CALL_CNT, ctx);
295 emit(A64_CMP(1, tcc, tmp), ctx);
296 emit(A64_B_(A64_COND_HI, jmp_offset), ctx);
297 emit(A64_ADD_I(1, tcc, tcc, 1), ctx);
298
299
300
301
302
303 off = offsetof(struct bpf_array, ptrs);
304 emit_a64_mov_i64(tmp, off, ctx);
305 emit(A64_ADD(1, tmp, r2, tmp), ctx);
306 emit(A64_LSL(1, prg, r3, 3), ctx);
307 emit(A64_LDR64(prg, tmp, prg), ctx);
308 emit(A64_CBZ(1, prg, jmp_offset), ctx);
309
310
311 off = offsetof(struct bpf_prog, bpf_func);
312 emit_a64_mov_i64(tmp, off, ctx);
313 emit(A64_LDR64(tmp, prg, tmp), ctx);
314 emit(A64_ADD_I(1, tmp, tmp, sizeof(u32) * PROLOGUE_OFFSET), ctx);
315 emit(A64_ADD_I(1, A64_SP, A64_SP, ctx->stack_size), ctx);
316 emit(A64_BR(tmp), ctx);
317
318
319 if (out_offset == -1)
320 out_offset = cur_offset;
321 if (cur_offset != out_offset) {
322 pr_err_once("tail_call out_offset = %d, expected %d!\n",
323 cur_offset, out_offset);
324 return -1;
325 }
326 return 0;
327#undef cur_offset
328#undef jmp_offset
329}
330
331static void build_epilogue(struct jit_ctx *ctx)
332{
333 const u8 r0 = bpf2a64[BPF_REG_0];
334 const u8 r6 = bpf2a64[BPF_REG_6];
335 const u8 r7 = bpf2a64[BPF_REG_7];
336 const u8 r8 = bpf2a64[BPF_REG_8];
337 const u8 r9 = bpf2a64[BPF_REG_9];
338 const u8 fp = bpf2a64[BPF_REG_FP];
339
340
341 emit(A64_ADD_I(1, A64_SP, A64_SP, ctx->stack_size), ctx);
342
343
344 emit(A64_POP(fp, A64_R(26), A64_SP), ctx);
345
346
347 emit(A64_POP(r8, r9, A64_SP), ctx);
348 emit(A64_POP(r6, r7, A64_SP), ctx);
349
350
351 emit(A64_POP(A64_FP, A64_LR, A64_SP), ctx);
352
353
354 emit(A64_MOV(1, A64_R(0), r0), ctx);
355
356 emit(A64_RET(A64_LR), ctx);
357}
358
359#define BPF_FIXUP_OFFSET_MASK GENMASK(26, 0)
360#define BPF_FIXUP_REG_MASK GENMASK(31, 27)
361
362int arm64_bpf_fixup_exception(const struct exception_table_entry *ex,
363 struct pt_regs *regs)
364{
365 off_t offset = FIELD_GET(BPF_FIXUP_OFFSET_MASK, ex->fixup);
366 int dst_reg = FIELD_GET(BPF_FIXUP_REG_MASK, ex->fixup);
367
368 regs->regs[dst_reg] = 0;
369 regs->pc = (unsigned long)&ex->fixup - offset;
370 return 1;
371}
372
373
374static int add_exception_handler(const struct bpf_insn *insn,
375 struct jit_ctx *ctx,
376 int dst_reg)
377{
378 off_t offset;
379 unsigned long pc;
380 struct exception_table_entry *ex;
381
382 if (!ctx->image)
383
384 return 0;
385
386 if (BPF_MODE(insn->code) != BPF_PROBE_MEM)
387 return 0;
388
389 if (!ctx->prog->aux->extable ||
390 WARN_ON_ONCE(ctx->exentry_idx >= ctx->prog->aux->num_exentries))
391 return -EINVAL;
392
393 ex = &ctx->prog->aux->extable[ctx->exentry_idx];
394 pc = (unsigned long)&ctx->image[ctx->idx - 1];
395
396 offset = pc - (long)&ex->insn;
397 if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN))
398 return -ERANGE;
399 ex->insn = offset;
400
401
402
403
404
405
406
407
408
409 offset = (long)&ex->fixup - (pc + AARCH64_INSN_SIZE);
410 if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, offset))
411 return -ERANGE;
412
413 ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, offset) |
414 FIELD_PREP(BPF_FIXUP_REG_MASK, dst_reg);
415
416 ctx->exentry_idx++;
417 return 0;
418}
419
420
421
422
423
424
425
426static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
427 bool extra_pass)
428{
429 const u8 code = insn->code;
430 const u8 dst = bpf2a64[insn->dst_reg];
431 const u8 src = bpf2a64[insn->src_reg];
432 const u8 tmp = bpf2a64[TMP_REG_1];
433 const u8 tmp2 = bpf2a64[TMP_REG_2];
434 const u8 tmp3 = bpf2a64[TMP_REG_3];
435 const s16 off = insn->off;
436 const s32 imm = insn->imm;
437 const int i = insn - ctx->prog->insnsi;
438 const bool is64 = BPF_CLASS(code) == BPF_ALU64 ||
439 BPF_CLASS(code) == BPF_JMP;
440 const bool isdw = BPF_SIZE(code) == BPF_DW;
441 u8 jmp_cond, reg;
442 s32 jmp_offset;
443 u32 a64_insn;
444 int ret;
445
446#define check_imm(bits, imm) do { \
447 if ((((imm) > 0) && ((imm) >> (bits))) || \
448 (((imm) < 0) && (~(imm) >> (bits)))) { \
449 pr_info("[%2d] imm=%d(0x%x) out of range\n", \
450 i, imm, imm); \
451 return -EINVAL; \
452 } \
453} while (0)
454#define check_imm19(imm) check_imm(19, imm)
455#define check_imm26(imm) check_imm(26, imm)
456
457 switch (code) {
458
459 case BPF_ALU | BPF_MOV | BPF_X:
460 case BPF_ALU64 | BPF_MOV | BPF_X:
461 emit(A64_MOV(is64, dst, src), ctx);
462 break;
463
464 case BPF_ALU | BPF_ADD | BPF_X:
465 case BPF_ALU64 | BPF_ADD | BPF_X:
466 emit(A64_ADD(is64, dst, dst, src), ctx);
467 break;
468 case BPF_ALU | BPF_SUB | BPF_X:
469 case BPF_ALU64 | BPF_SUB | BPF_X:
470 emit(A64_SUB(is64, dst, dst, src), ctx);
471 break;
472 case BPF_ALU | BPF_AND | BPF_X:
473 case BPF_ALU64 | BPF_AND | BPF_X:
474 emit(A64_AND(is64, dst, dst, src), ctx);
475 break;
476 case BPF_ALU | BPF_OR | BPF_X:
477 case BPF_ALU64 | BPF_OR | BPF_X:
478 emit(A64_ORR(is64, dst, dst, src), ctx);
479 break;
480 case BPF_ALU | BPF_XOR | BPF_X:
481 case BPF_ALU64 | BPF_XOR | BPF_X:
482 emit(A64_EOR(is64, dst, dst, src), ctx);
483 break;
484 case BPF_ALU | BPF_MUL | BPF_X:
485 case BPF_ALU64 | BPF_MUL | BPF_X:
486 emit(A64_MUL(is64, dst, dst, src), ctx);
487 break;
488 case BPF_ALU | BPF_DIV | BPF_X:
489 case BPF_ALU64 | BPF_DIV | BPF_X:
490 case BPF_ALU | BPF_MOD | BPF_X:
491 case BPF_ALU64 | BPF_MOD | BPF_X:
492 switch (BPF_OP(code)) {
493 case BPF_DIV:
494 emit(A64_UDIV(is64, dst, dst, src), ctx);
495 break;
496 case BPF_MOD:
497 emit(A64_UDIV(is64, tmp, dst, src), ctx);
498 emit(A64_MSUB(is64, dst, dst, tmp, src), ctx);
499 break;
500 }
501 break;
502 case BPF_ALU | BPF_LSH | BPF_X:
503 case BPF_ALU64 | BPF_LSH | BPF_X:
504 emit(A64_LSLV(is64, dst, dst, src), ctx);
505 break;
506 case BPF_ALU | BPF_RSH | BPF_X:
507 case BPF_ALU64 | BPF_RSH | BPF_X:
508 emit(A64_LSRV(is64, dst, dst, src), ctx);
509 break;
510 case BPF_ALU | BPF_ARSH | BPF_X:
511 case BPF_ALU64 | BPF_ARSH | BPF_X:
512 emit(A64_ASRV(is64, dst, dst, src), ctx);
513 break;
514
515 case BPF_ALU | BPF_NEG:
516 case BPF_ALU64 | BPF_NEG:
517 emit(A64_NEG(is64, dst, dst), ctx);
518 break;
519
520 case BPF_ALU | BPF_END | BPF_FROM_LE:
521 case BPF_ALU | BPF_END | BPF_FROM_BE:
522#ifdef CONFIG_CPU_BIG_ENDIAN
523 if (BPF_SRC(code) == BPF_FROM_BE)
524 goto emit_bswap_uxt;
525#else
526 if (BPF_SRC(code) == BPF_FROM_LE)
527 goto emit_bswap_uxt;
528#endif
529 switch (imm) {
530 case 16:
531 emit(A64_REV16(is64, dst, dst), ctx);
532
533 emit(A64_UXTH(is64, dst, dst), ctx);
534 break;
535 case 32:
536 emit(A64_REV32(is64, dst, dst), ctx);
537
538 break;
539 case 64:
540 emit(A64_REV64(dst, dst), ctx);
541 break;
542 }
543 break;
544emit_bswap_uxt:
545 switch (imm) {
546 case 16:
547
548 emit(A64_UXTH(is64, dst, dst), ctx);
549 break;
550 case 32:
551
552 emit(A64_UXTW(is64, dst, dst), ctx);
553 break;
554 case 64:
555
556 break;
557 }
558 break;
559
560 case BPF_ALU | BPF_MOV | BPF_K:
561 case BPF_ALU64 | BPF_MOV | BPF_K:
562 emit_a64_mov_i(is64, dst, imm, ctx);
563 break;
564
565 case BPF_ALU | BPF_ADD | BPF_K:
566 case BPF_ALU64 | BPF_ADD | BPF_K:
567 if (is_addsub_imm(imm)) {
568 emit(A64_ADD_I(is64, dst, dst, imm), ctx);
569 } else if (is_addsub_imm(-imm)) {
570 emit(A64_SUB_I(is64, dst, dst, -imm), ctx);
571 } else {
572 emit_a64_mov_i(is64, tmp, imm, ctx);
573 emit(A64_ADD(is64, dst, dst, tmp), ctx);
574 }
575 break;
576 case BPF_ALU | BPF_SUB | BPF_K:
577 case BPF_ALU64 | BPF_SUB | BPF_K:
578 if (is_addsub_imm(imm)) {
579 emit(A64_SUB_I(is64, dst, dst, imm), ctx);
580 } else if (is_addsub_imm(-imm)) {
581 emit(A64_ADD_I(is64, dst, dst, -imm), ctx);
582 } else {
583 emit_a64_mov_i(is64, tmp, imm, ctx);
584 emit(A64_SUB(is64, dst, dst, tmp), ctx);
585 }
586 break;
587 case BPF_ALU | BPF_AND | BPF_K:
588 case BPF_ALU64 | BPF_AND | BPF_K:
589 a64_insn = A64_AND_I(is64, dst, dst, imm);
590 if (a64_insn != AARCH64_BREAK_FAULT) {
591 emit(a64_insn, ctx);
592 } else {
593 emit_a64_mov_i(is64, tmp, imm, ctx);
594 emit(A64_AND(is64, dst, dst, tmp), ctx);
595 }
596 break;
597 case BPF_ALU | BPF_OR | BPF_K:
598 case BPF_ALU64 | BPF_OR | BPF_K:
599 a64_insn = A64_ORR_I(is64, dst, dst, imm);
600 if (a64_insn != AARCH64_BREAK_FAULT) {
601 emit(a64_insn, ctx);
602 } else {
603 emit_a64_mov_i(is64, tmp, imm, ctx);
604 emit(A64_ORR(is64, dst, dst, tmp), ctx);
605 }
606 break;
607 case BPF_ALU | BPF_XOR | BPF_K:
608 case BPF_ALU64 | BPF_XOR | BPF_K:
609 a64_insn = A64_EOR_I(is64, dst, dst, imm);
610 if (a64_insn != AARCH64_BREAK_FAULT) {
611 emit(a64_insn, ctx);
612 } else {
613 emit_a64_mov_i(is64, tmp, imm, ctx);
614 emit(A64_EOR(is64, dst, dst, tmp), ctx);
615 }
616 break;
617 case BPF_ALU | BPF_MUL | BPF_K:
618 case BPF_ALU64 | BPF_MUL | BPF_K:
619 emit_a64_mov_i(is64, tmp, imm, ctx);
620 emit(A64_MUL(is64, dst, dst, tmp), ctx);
621 break;
622 case BPF_ALU | BPF_DIV | BPF_K:
623 case BPF_ALU64 | BPF_DIV | BPF_K:
624 emit_a64_mov_i(is64, tmp, imm, ctx);
625 emit(A64_UDIV(is64, dst, dst, tmp), ctx);
626 break;
627 case BPF_ALU | BPF_MOD | BPF_K:
628 case BPF_ALU64 | BPF_MOD | BPF_K:
629 emit_a64_mov_i(is64, tmp2, imm, ctx);
630 emit(A64_UDIV(is64, tmp, dst, tmp2), ctx);
631 emit(A64_MSUB(is64, dst, dst, tmp, tmp2), ctx);
632 break;
633 case BPF_ALU | BPF_LSH | BPF_K:
634 case BPF_ALU64 | BPF_LSH | BPF_K:
635 emit(A64_LSL(is64, dst, dst, imm), ctx);
636 break;
637 case BPF_ALU | BPF_RSH | BPF_K:
638 case BPF_ALU64 | BPF_RSH | BPF_K:
639 emit(A64_LSR(is64, dst, dst, imm), ctx);
640 break;
641 case BPF_ALU | BPF_ARSH | BPF_K:
642 case BPF_ALU64 | BPF_ARSH | BPF_K:
643 emit(A64_ASR(is64, dst, dst, imm), ctx);
644 break;
645
646
647 case BPF_JMP | BPF_JA:
648 jmp_offset = bpf2a64_offset(i, off, ctx);
649 check_imm26(jmp_offset);
650 emit(A64_B(jmp_offset), ctx);
651 break;
652
653 case BPF_JMP | BPF_JEQ | BPF_X:
654 case BPF_JMP | BPF_JGT | BPF_X:
655 case BPF_JMP | BPF_JLT | BPF_X:
656 case BPF_JMP | BPF_JGE | BPF_X:
657 case BPF_JMP | BPF_JLE | BPF_X:
658 case BPF_JMP | BPF_JNE | BPF_X:
659 case BPF_JMP | BPF_JSGT | BPF_X:
660 case BPF_JMP | BPF_JSLT | BPF_X:
661 case BPF_JMP | BPF_JSGE | BPF_X:
662 case BPF_JMP | BPF_JSLE | BPF_X:
663 case BPF_JMP32 | BPF_JEQ | BPF_X:
664 case BPF_JMP32 | BPF_JGT | BPF_X:
665 case BPF_JMP32 | BPF_JLT | BPF_X:
666 case BPF_JMP32 | BPF_JGE | BPF_X:
667 case BPF_JMP32 | BPF_JLE | BPF_X:
668 case BPF_JMP32 | BPF_JNE | BPF_X:
669 case BPF_JMP32 | BPF_JSGT | BPF_X:
670 case BPF_JMP32 | BPF_JSLT | BPF_X:
671 case BPF_JMP32 | BPF_JSGE | BPF_X:
672 case BPF_JMP32 | BPF_JSLE | BPF_X:
673 emit(A64_CMP(is64, dst, src), ctx);
674emit_cond_jmp:
675 jmp_offset = bpf2a64_offset(i, off, ctx);
676 check_imm19(jmp_offset);
677 switch (BPF_OP(code)) {
678 case BPF_JEQ:
679 jmp_cond = A64_COND_EQ;
680 break;
681 case BPF_JGT:
682 jmp_cond = A64_COND_HI;
683 break;
684 case BPF_JLT:
685 jmp_cond = A64_COND_CC;
686 break;
687 case BPF_JGE:
688 jmp_cond = A64_COND_CS;
689 break;
690 case BPF_JLE:
691 jmp_cond = A64_COND_LS;
692 break;
693 case BPF_JSET:
694 case BPF_JNE:
695 jmp_cond = A64_COND_NE;
696 break;
697 case BPF_JSGT:
698 jmp_cond = A64_COND_GT;
699 break;
700 case BPF_JSLT:
701 jmp_cond = A64_COND_LT;
702 break;
703 case BPF_JSGE:
704 jmp_cond = A64_COND_GE;
705 break;
706 case BPF_JSLE:
707 jmp_cond = A64_COND_LE;
708 break;
709 default:
710 return -EFAULT;
711 }
712 emit(A64_B_(jmp_cond, jmp_offset), ctx);
713 break;
714 case BPF_JMP | BPF_JSET | BPF_X:
715 case BPF_JMP32 | BPF_JSET | BPF_X:
716 emit(A64_TST(is64, dst, src), ctx);
717 goto emit_cond_jmp;
718
719 case BPF_JMP | BPF_JEQ | BPF_K:
720 case BPF_JMP | BPF_JGT | BPF_K:
721 case BPF_JMP | BPF_JLT | BPF_K:
722 case BPF_JMP | BPF_JGE | BPF_K:
723 case BPF_JMP | BPF_JLE | BPF_K:
724 case BPF_JMP | BPF_JNE | BPF_K:
725 case BPF_JMP | BPF_JSGT | BPF_K:
726 case BPF_JMP | BPF_JSLT | BPF_K:
727 case BPF_JMP | BPF_JSGE | BPF_K:
728 case BPF_JMP | BPF_JSLE | BPF_K:
729 case BPF_JMP32 | BPF_JEQ | BPF_K:
730 case BPF_JMP32 | BPF_JGT | BPF_K:
731 case BPF_JMP32 | BPF_JLT | BPF_K:
732 case BPF_JMP32 | BPF_JGE | BPF_K:
733 case BPF_JMP32 | BPF_JLE | BPF_K:
734 case BPF_JMP32 | BPF_JNE | BPF_K:
735 case BPF_JMP32 | BPF_JSGT | BPF_K:
736 case BPF_JMP32 | BPF_JSLT | BPF_K:
737 case BPF_JMP32 | BPF_JSGE | BPF_K:
738 case BPF_JMP32 | BPF_JSLE | BPF_K:
739 if (is_addsub_imm(imm)) {
740 emit(A64_CMP_I(is64, dst, imm), ctx);
741 } else if (is_addsub_imm(-imm)) {
742 emit(A64_CMN_I(is64, dst, -imm), ctx);
743 } else {
744 emit_a64_mov_i(is64, tmp, imm, ctx);
745 emit(A64_CMP(is64, dst, tmp), ctx);
746 }
747 goto emit_cond_jmp;
748 case BPF_JMP | BPF_JSET | BPF_K:
749 case BPF_JMP32 | BPF_JSET | BPF_K:
750 a64_insn = A64_TST_I(is64, dst, imm);
751 if (a64_insn != AARCH64_BREAK_FAULT) {
752 emit(a64_insn, ctx);
753 } else {
754 emit_a64_mov_i(is64, tmp, imm, ctx);
755 emit(A64_TST(is64, dst, tmp), ctx);
756 }
757 goto emit_cond_jmp;
758
759 case BPF_JMP | BPF_CALL:
760 {
761 const u8 r0 = bpf2a64[BPF_REG_0];
762 bool func_addr_fixed;
763 u64 func_addr;
764
765 ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass,
766 &func_addr, &func_addr_fixed);
767 if (ret < 0)
768 return ret;
769 emit_addr_mov_i64(tmp, func_addr, ctx);
770 emit(A64_BLR(tmp), ctx);
771 emit(A64_MOV(1, r0, A64_R(0)), ctx);
772 break;
773 }
774
775 case BPF_JMP | BPF_TAIL_CALL:
776 if (emit_bpf_tail_call(ctx))
777 return -EFAULT;
778 break;
779
780 case BPF_JMP | BPF_EXIT:
781
782
783 if (i == ctx->prog->len - 1)
784 break;
785 jmp_offset = epilogue_offset(ctx);
786 check_imm26(jmp_offset);
787 emit(A64_B(jmp_offset), ctx);
788 break;
789
790
791 case BPF_LD | BPF_IMM | BPF_DW:
792 {
793 const struct bpf_insn insn1 = insn[1];
794 u64 imm64;
795
796 imm64 = (u64)insn1.imm << 32 | (u32)imm;
797 emit_a64_mov_i64(dst, imm64, ctx);
798
799 return 1;
800 }
801
802
803 case BPF_LDX | BPF_MEM | BPF_W:
804 case BPF_LDX | BPF_MEM | BPF_H:
805 case BPF_LDX | BPF_MEM | BPF_B:
806 case BPF_LDX | BPF_MEM | BPF_DW:
807 case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
808 case BPF_LDX | BPF_PROBE_MEM | BPF_W:
809 case BPF_LDX | BPF_PROBE_MEM | BPF_H:
810 case BPF_LDX | BPF_PROBE_MEM | BPF_B:
811 emit_a64_mov_i(1, tmp, off, ctx);
812 switch (BPF_SIZE(code)) {
813 case BPF_W:
814 emit(A64_LDR32(dst, src, tmp), ctx);
815 break;
816 case BPF_H:
817 emit(A64_LDRH(dst, src, tmp), ctx);
818 break;
819 case BPF_B:
820 emit(A64_LDRB(dst, src, tmp), ctx);
821 break;
822 case BPF_DW:
823 emit(A64_LDR64(dst, src, tmp), ctx);
824 break;
825 }
826
827 ret = add_exception_handler(insn, ctx, dst);
828 if (ret)
829 return ret;
830 break;
831
832
833 case BPF_ST | BPF_MEM | BPF_W:
834 case BPF_ST | BPF_MEM | BPF_H:
835 case BPF_ST | BPF_MEM | BPF_B:
836 case BPF_ST | BPF_MEM | BPF_DW:
837
838 emit_a64_mov_i(1, tmp2, off, ctx);
839 emit_a64_mov_i(1, tmp, imm, ctx);
840 switch (BPF_SIZE(code)) {
841 case BPF_W:
842 emit(A64_STR32(tmp, dst, tmp2), ctx);
843 break;
844 case BPF_H:
845 emit(A64_STRH(tmp, dst, tmp2), ctx);
846 break;
847 case BPF_B:
848 emit(A64_STRB(tmp, dst, tmp2), ctx);
849 break;
850 case BPF_DW:
851 emit(A64_STR64(tmp, dst, tmp2), ctx);
852 break;
853 }
854 break;
855
856
857 case BPF_STX | BPF_MEM | BPF_W:
858 case BPF_STX | BPF_MEM | BPF_H:
859 case BPF_STX | BPF_MEM | BPF_B:
860 case BPF_STX | BPF_MEM | BPF_DW:
861 emit_a64_mov_i(1, tmp, off, ctx);
862 switch (BPF_SIZE(code)) {
863 case BPF_W:
864 emit(A64_STR32(src, dst, tmp), ctx);
865 break;
866 case BPF_H:
867 emit(A64_STRH(src, dst, tmp), ctx);
868 break;
869 case BPF_B:
870 emit(A64_STRB(src, dst, tmp), ctx);
871 break;
872 case BPF_DW:
873 emit(A64_STR64(src, dst, tmp), ctx);
874 break;
875 }
876 break;
877
878
879 case BPF_STX | BPF_XADD | BPF_W:
880
881 case BPF_STX | BPF_XADD | BPF_DW:
882 if (!off) {
883 reg = dst;
884 } else {
885 emit_a64_mov_i(1, tmp, off, ctx);
886 emit(A64_ADD(1, tmp, tmp, dst), ctx);
887 reg = tmp;
888 }
889 if (cpus_have_cap(ARM64_HAS_LSE_ATOMICS)) {
890 emit(A64_STADD(isdw, reg, src), ctx);
891 } else {
892 emit(A64_LDXR(isdw, tmp2, reg), ctx);
893 emit(A64_ADD(isdw, tmp2, tmp2, src), ctx);
894 emit(A64_STXR(isdw, tmp2, reg, tmp3), ctx);
895 jmp_offset = -3;
896 check_imm19(jmp_offset);
897 emit(A64_CBNZ(0, tmp3, jmp_offset), ctx);
898 }
899 break;
900
901 default:
902 pr_err_once("unknown opcode %02x\n", code);
903 return -EINVAL;
904 }
905
906 return 0;
907}
908
909static int build_body(struct jit_ctx *ctx, bool extra_pass)
910{
911 const struct bpf_prog *prog = ctx->prog;
912 int i;
913
914
915
916
917
918
919
920
921
922
923 for (i = 0; i < prog->len; i++) {
924 const struct bpf_insn *insn = &prog->insnsi[i];
925 int ret;
926
927 if (ctx->image == NULL)
928 ctx->offset[i] = ctx->idx;
929 ret = build_insn(insn, ctx, extra_pass);
930 if (ret > 0) {
931 i++;
932 if (ctx->image == NULL)
933 ctx->offset[i] = ctx->idx;
934 continue;
935 }
936 if (ret)
937 return ret;
938 }
939
940
941
942
943
944 if (ctx->image == NULL)
945 ctx->offset[i] = ctx->idx;
946
947 return 0;
948}
949
950static int validate_code(struct jit_ctx *ctx)
951{
952 int i;
953
954 for (i = 0; i < ctx->idx; i++) {
955 u32 a64_insn = le32_to_cpu(ctx->image[i]);
956
957 if (a64_insn == AARCH64_BREAK_FAULT)
958 return -1;
959 }
960
961 if (WARN_ON_ONCE(ctx->exentry_idx != ctx->prog->aux->num_exentries))
962 return -1;
963
964 return 0;
965}
966
967static inline void bpf_flush_icache(void *start, void *end)
968{
969 flush_icache_range((unsigned long)start, (unsigned long)end);
970}
971
972struct arm64_jit_data {
973 struct bpf_binary_header *header;
974 u8 *image;
975 struct jit_ctx ctx;
976};
977
978struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
979{
980 int image_size, prog_size, extable_size;
981 struct bpf_prog *tmp, *orig_prog = prog;
982 struct bpf_binary_header *header;
983 struct arm64_jit_data *jit_data;
984 bool was_classic = bpf_prog_was_classic(prog);
985 bool tmp_blinded = false;
986 bool extra_pass = false;
987 struct jit_ctx ctx;
988 u8 *image_ptr;
989
990 if (!prog->jit_requested)
991 return orig_prog;
992
993 tmp = bpf_jit_blind_constants(prog);
994
995
996
997 if (IS_ERR(tmp))
998 return orig_prog;
999 if (tmp != prog) {
1000 tmp_blinded = true;
1001 prog = tmp;
1002 }
1003
1004 jit_data = prog->aux->jit_data;
1005 if (!jit_data) {
1006 jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
1007 if (!jit_data) {
1008 prog = orig_prog;
1009 goto out;
1010 }
1011 prog->aux->jit_data = jit_data;
1012 }
1013 if (jit_data->ctx.offset) {
1014 ctx = jit_data->ctx;
1015 image_ptr = jit_data->image;
1016 header = jit_data->header;
1017 extra_pass = true;
1018 prog_size = sizeof(u32) * ctx.idx;
1019 goto skip_init_ctx;
1020 }
1021 memset(&ctx, 0, sizeof(ctx));
1022 ctx.prog = prog;
1023
1024 ctx.offset = kcalloc(prog->len + 1, sizeof(int), GFP_KERNEL);
1025 if (ctx.offset == NULL) {
1026 prog = orig_prog;
1027 goto out_off;
1028 }
1029
1030
1031
1032
1033 if (build_body(&ctx, extra_pass)) {
1034 prog = orig_prog;
1035 goto out_off;
1036 }
1037
1038 if (build_prologue(&ctx, was_classic)) {
1039 prog = orig_prog;
1040 goto out_off;
1041 }
1042
1043 ctx.epilogue_offset = ctx.idx;
1044 build_epilogue(&ctx);
1045
1046 extable_size = prog->aux->num_exentries *
1047 sizeof(struct exception_table_entry);
1048
1049
1050 prog_size = sizeof(u32) * ctx.idx;
1051 image_size = prog_size + extable_size;
1052 header = bpf_jit_binary_alloc(image_size, &image_ptr,
1053 sizeof(u32), jit_fill_hole);
1054 if (header == NULL) {
1055 prog = orig_prog;
1056 goto out_off;
1057 }
1058
1059
1060
1061 ctx.image = (__le32 *)image_ptr;
1062 if (extable_size)
1063 prog->aux->extable = (void *)image_ptr + prog_size;
1064skip_init_ctx:
1065 ctx.idx = 0;
1066 ctx.exentry_idx = 0;
1067
1068 build_prologue(&ctx, was_classic);
1069
1070 if (build_body(&ctx, extra_pass)) {
1071 bpf_jit_binary_free(header);
1072 prog = orig_prog;
1073 goto out_off;
1074 }
1075
1076 build_epilogue(&ctx);
1077
1078
1079 if (validate_code(&ctx)) {
1080 bpf_jit_binary_free(header);
1081 prog = orig_prog;
1082 goto out_off;
1083 }
1084
1085
1086 if (bpf_jit_enable > 1)
1087 bpf_jit_dump(prog->len, prog_size, 2, ctx.image);
1088
1089 bpf_flush_icache(header, ctx.image + ctx.idx);
1090
1091 if (!prog->is_func || extra_pass) {
1092 if (extra_pass && ctx.idx != jit_data->ctx.idx) {
1093 pr_err_once("multi-func JIT bug %d != %d\n",
1094 ctx.idx, jit_data->ctx.idx);
1095 bpf_jit_binary_free(header);
1096 prog->bpf_func = NULL;
1097 prog->jited = 0;
1098 goto out_off;
1099 }
1100 bpf_jit_binary_lock_ro(header);
1101 } else {
1102 jit_data->ctx = ctx;
1103 jit_data->image = image_ptr;
1104 jit_data->header = header;
1105 }
1106 prog->bpf_func = (void *)ctx.image;
1107 prog->jited = 1;
1108 prog->jited_len = prog_size;
1109
1110 if (!prog->is_func || extra_pass) {
1111 bpf_prog_fill_jited_linfo(prog, ctx.offset + 1);
1112out_off:
1113 kfree(ctx.offset);
1114 kfree(jit_data);
1115 prog->aux->jit_data = NULL;
1116 }
1117out:
1118 if (tmp_blinded)
1119 bpf_jit_prog_release_other(prog, prog == orig_prog ?
1120 tmp : orig_prog);
1121 return prog;
1122}
1123
1124void *bpf_jit_alloc_exec(unsigned long size)
1125{
1126 return __vmalloc_node_range(size, PAGE_SIZE, BPF_JIT_REGION_START,
1127 BPF_JIT_REGION_END, GFP_KERNEL,
1128 PAGE_KERNEL, 0, NUMA_NO_NODE,
1129 __builtin_return_address(0));
1130}
1131
1132void bpf_jit_free_exec(void *addr)
1133{
1134 return vfree(addr);
1135}
1136