1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * BPF JIT compiler for LoongArch 4 * 5 * Copyright (C) 2022 Loongson Technology Corporation Limited 6 */ 7 #include "bpf_jit.h" 8 9 #define REG_TCC LOONGARCH_GPR_A6 10 #define TCC_SAVED LOONGARCH_GPR_S5 11 12 #define SAVE_RA BIT(0) 13 #define SAVE_TCC BIT(1) 14 15 static const int regmap[] = { 16 /* return value from in-kernel function, and exit value for eBPF program */ 17 [BPF_REG_0] = LOONGARCH_GPR_A5, 18 /* arguments from eBPF program to in-kernel function */ 19 [BPF_REG_1] = LOONGARCH_GPR_A0, 20 [BPF_REG_2] = LOONGARCH_GPR_A1, 21 [BPF_REG_3] = LOONGARCH_GPR_A2, 22 [BPF_REG_4] = LOONGARCH_GPR_A3, 23 [BPF_REG_5] = LOONGARCH_GPR_A4, 24 /* callee saved registers that in-kernel function will preserve */ 25 [BPF_REG_6] = LOONGARCH_GPR_S0, 26 [BPF_REG_7] = LOONGARCH_GPR_S1, 27 [BPF_REG_8] = LOONGARCH_GPR_S2, 28 [BPF_REG_9] = LOONGARCH_GPR_S3, 29 /* read-only frame pointer to access stack */ 30 [BPF_REG_FP] = LOONGARCH_GPR_S4, 31 /* temporary register for blinding constants */ 32 [BPF_REG_AX] = LOONGARCH_GPR_T0, 33 }; 34 35 static void mark_call(struct jit_ctx *ctx) 36 { 37 ctx->flags |= SAVE_RA; 38 } 39 40 static void mark_tail_call(struct jit_ctx *ctx) 41 { 42 ctx->flags |= SAVE_TCC; 43 } 44 45 static bool seen_call(struct jit_ctx *ctx) 46 { 47 return (ctx->flags & SAVE_RA); 48 } 49 50 static bool seen_tail_call(struct jit_ctx *ctx) 51 { 52 return (ctx->flags & SAVE_TCC); 53 } 54 55 static u8 tail_call_reg(struct jit_ctx *ctx) 56 { 57 if (seen_call(ctx)) 58 return TCC_SAVED; 59 60 return REG_TCC; 61 } 62 63 /* 64 * eBPF prog stack layout: 65 * 66 * high 67 * original $sp ------------> +-------------------------+ <--LOONGARCH_GPR_FP 68 * | $ra | 69 * +-------------------------+ 70 * | $fp | 71 * +-------------------------+ 72 * | $s0 | 73 * +-------------------------+ 74 * | $s1 | 75 * +-------------------------+ 76 * | $s2 | 77 * +-------------------------+ 78 * | $s3 | 79 * +-------------------------+ 80 * | $s4 | 81 * +-------------------------+ 82 * | $s5 | 83 * +-------------------------+ <--BPF_REG_FP 84 * | prog->aux->stack_depth | 85 * | (optional) | 86 * current $sp -------------> +-------------------------+ 87 * low 88 */ 89 static void build_prologue(struct jit_ctx *ctx) 90 { 91 int stack_adjust = 0, store_offset, bpf_stack_adjust; 92 93 bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16); 94 95 /* To store ra, fp, s0, s1, s2, s3, s4 and s5. */ 96 stack_adjust += sizeof(long) * 8; 97 98 stack_adjust = round_up(stack_adjust, 16); 99 stack_adjust += bpf_stack_adjust; 100 101 /* 102 * First instruction initializes the tail call count (TCC). 103 * On tail call we skip this instruction, and the TCC is 104 * passed in REG_TCC from the caller. 105 */ 106 emit_insn(ctx, addid, REG_TCC, LOONGARCH_GPR_ZERO, MAX_TAIL_CALL_CNT); 107 108 emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_adjust); 109 110 store_offset = stack_adjust - sizeof(long); 111 emit_insn(ctx, std, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, store_offset); 112 113 store_offset -= sizeof(long); 114 emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, store_offset); 115 116 store_offset -= sizeof(long); 117 emit_insn(ctx, std, LOONGARCH_GPR_S0, LOONGARCH_GPR_SP, store_offset); 118 119 store_offset -= sizeof(long); 120 emit_insn(ctx, std, LOONGARCH_GPR_S1, LOONGARCH_GPR_SP, store_offset); 121 122 store_offset -= sizeof(long); 123 emit_insn(ctx, std, LOONGARCH_GPR_S2, LOONGARCH_GPR_SP, store_offset); 124 125 store_offset -= sizeof(long); 126 emit_insn(ctx, std, LOONGARCH_GPR_S3, LOONGARCH_GPR_SP, store_offset); 127 128 store_offset -= sizeof(long); 129 emit_insn(ctx, std, LOONGARCH_GPR_S4, LOONGARCH_GPR_SP, store_offset); 130 131 store_offset -= sizeof(long); 132 emit_insn(ctx, std, LOONGARCH_GPR_S5, LOONGARCH_GPR_SP, store_offset); 133 134 emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_adjust); 135 136 if (bpf_stack_adjust) 137 emit_insn(ctx, addid, regmap[BPF_REG_FP], LOONGARCH_GPR_SP, bpf_stack_adjust); 138 139 /* 140 * Program contains calls and tail calls, so REG_TCC need 141 * to be saved across calls. 142 */ 143 if (seen_tail_call(ctx) && seen_call(ctx)) 144 move_reg(ctx, TCC_SAVED, REG_TCC); 145 146 ctx->stack_size = stack_adjust; 147 } 148 149 static void __build_epilogue(struct jit_ctx *ctx, bool is_tail_call) 150 { 151 int stack_adjust = ctx->stack_size; 152 int load_offset; 153 154 load_offset = stack_adjust - sizeof(long); 155 emit_insn(ctx, ldd, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, load_offset); 156 157 load_offset -= sizeof(long); 158 emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, load_offset); 159 160 load_offset -= sizeof(long); 161 emit_insn(ctx, ldd, LOONGARCH_GPR_S0, LOONGARCH_GPR_SP, load_offset); 162 163 load_offset -= sizeof(long); 164 emit_insn(ctx, ldd, LOONGARCH_GPR_S1, LOONGARCH_GPR_SP, load_offset); 165 166 load_offset -= sizeof(long); 167 emit_insn(ctx, ldd, LOONGARCH_GPR_S2, LOONGARCH_GPR_SP, load_offset); 168 169 load_offset -= sizeof(long); 170 emit_insn(ctx, ldd, LOONGARCH_GPR_S3, LOONGARCH_GPR_SP, load_offset); 171 172 load_offset -= sizeof(long); 173 emit_insn(ctx, ldd, LOONGARCH_GPR_S4, LOONGARCH_GPR_SP, load_offset); 174 175 load_offset -= sizeof(long); 176 emit_insn(ctx, ldd, LOONGARCH_GPR_S5, LOONGARCH_GPR_SP, load_offset); 177 178 emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_adjust); 179 180 if (!is_tail_call) { 181 /* Set return value */ 182 move_reg(ctx, LOONGARCH_GPR_A0, regmap[BPF_REG_0]); 183 /* Return to the caller */ 184 emit_insn(ctx, jirl, LOONGARCH_GPR_RA, LOONGARCH_GPR_ZERO, 0); 185 } else { 186 /* 187 * Call the next bpf prog and skip the first instruction 188 * of TCC initialization. 189 */ 190 emit_insn(ctx, jirl, LOONGARCH_GPR_T3, LOONGARCH_GPR_ZERO, 1); 191 } 192 } 193 194 static void build_epilogue(struct jit_ctx *ctx) 195 { 196 __build_epilogue(ctx, false); 197 } 198 199 bool bpf_jit_supports_kfunc_call(void) 200 { 201 return true; 202 } 203 204 /* initialized on the first pass of build_body() */ 205 static int out_offset = -1; 206 static int emit_bpf_tail_call(struct jit_ctx *ctx) 207 { 208 int off; 209 u8 tcc = tail_call_reg(ctx); 210 u8 a1 = LOONGARCH_GPR_A1; 211 u8 a2 = LOONGARCH_GPR_A2; 212 u8 t1 = LOONGARCH_GPR_T1; 213 u8 t2 = LOONGARCH_GPR_T2; 214 u8 t3 = LOONGARCH_GPR_T3; 215 const int idx0 = ctx->idx; 216 217 #define cur_offset (ctx->idx - idx0) 218 #define jmp_offset (out_offset - (cur_offset)) 219 220 /* 221 * a0: &ctx 222 * a1: &array 223 * a2: index 224 * 225 * if (index >= array->map.max_entries) 226 * goto out; 227 */ 228 off = offsetof(struct bpf_array, map.max_entries); 229 emit_insn(ctx, ldwu, t1, a1, off); 230 /* bgeu $a2, $t1, jmp_offset */ 231 if (emit_tailcall_jmp(ctx, BPF_JGE, a2, t1, jmp_offset) < 0) 232 goto toofar; 233 234 /* 235 * if (--TCC < 0) 236 * goto out; 237 */ 238 emit_insn(ctx, addid, REG_TCC, tcc, -1); 239 if (emit_tailcall_jmp(ctx, BPF_JSLT, REG_TCC, LOONGARCH_GPR_ZERO, jmp_offset) < 0) 240 goto toofar; 241 242 /* 243 * prog = array->ptrs[index]; 244 * if (!prog) 245 * goto out; 246 */ 247 emit_insn(ctx, alsld, t2, a2, a1, 2); 248 off = offsetof(struct bpf_array, ptrs); 249 emit_insn(ctx, ldd, t2, t2, off); 250 /* beq $t2, $zero, jmp_offset */ 251 if (emit_tailcall_jmp(ctx, BPF_JEQ, t2, LOONGARCH_GPR_ZERO, jmp_offset) < 0) 252 goto toofar; 253 254 /* goto *(prog->bpf_func + 4); */ 255 off = offsetof(struct bpf_prog, bpf_func); 256 emit_insn(ctx, ldd, t3, t2, off); 257 __build_epilogue(ctx, true); 258 259 /* out: */ 260 if (out_offset == -1) 261 out_offset = cur_offset; 262 if (cur_offset != out_offset) { 263 pr_err_once("tail_call out_offset = %d, expected %d!\n", 264 cur_offset, out_offset); 265 return -1; 266 } 267 268 return 0; 269 270 toofar: 271 pr_info_once("tail_call: jump too far\n"); 272 return -1; 273 #undef cur_offset 274 #undef jmp_offset 275 } 276 277 static void emit_atomic(const struct bpf_insn *insn, struct jit_ctx *ctx) 278 { 279 const u8 t1 = LOONGARCH_GPR_T1; 280 const u8 t2 = LOONGARCH_GPR_T2; 281 const u8 t3 = LOONGARCH_GPR_T3; 282 const u8 r0 = regmap[BPF_REG_0]; 283 const u8 src = regmap[insn->src_reg]; 284 const u8 dst = regmap[insn->dst_reg]; 285 const s16 off = insn->off; 286 const s32 imm = insn->imm; 287 const bool isdw = BPF_SIZE(insn->code) == BPF_DW; 288 289 move_imm(ctx, t1, off, false); 290 emit_insn(ctx, addd, t1, dst, t1); 291 move_reg(ctx, t3, src); 292 293 switch (imm) { 294 /* lock *(size *)(dst + off) <op>= src */ 295 case BPF_ADD: 296 if (isdw) 297 emit_insn(ctx, amaddd, t2, t1, src); 298 else 299 emit_insn(ctx, amaddw, t2, t1, src); 300 break; 301 case BPF_AND: 302 if (isdw) 303 emit_insn(ctx, amandd, t2, t1, src); 304 else 305 emit_insn(ctx, amandw, t2, t1, src); 306 break; 307 case BPF_OR: 308 if (isdw) 309 emit_insn(ctx, amord, t2, t1, src); 310 else 311 emit_insn(ctx, amorw, t2, t1, src); 312 break; 313 case BPF_XOR: 314 if (isdw) 315 emit_insn(ctx, amxord, t2, t1, src); 316 else 317 emit_insn(ctx, amxorw, t2, t1, src); 318 break; 319 /* src = atomic_fetch_<op>(dst + off, src) */ 320 case BPF_ADD | BPF_FETCH: 321 if (isdw) { 322 emit_insn(ctx, amaddd, src, t1, t3); 323 } else { 324 emit_insn(ctx, amaddw, src, t1, t3); 325 emit_zext_32(ctx, src, true); 326 } 327 break; 328 case BPF_AND | BPF_FETCH: 329 if (isdw) { 330 emit_insn(ctx, amandd, src, t1, t3); 331 } else { 332 emit_insn(ctx, amandw, src, t1, t3); 333 emit_zext_32(ctx, src, true); 334 } 335 break; 336 case BPF_OR | BPF_FETCH: 337 if (isdw) { 338 emit_insn(ctx, amord, src, t1, t3); 339 } else { 340 emit_insn(ctx, amorw, src, t1, t3); 341 emit_zext_32(ctx, src, true); 342 } 343 break; 344 case BPF_XOR | BPF_FETCH: 345 if (isdw) { 346 emit_insn(ctx, amxord, src, t1, t3); 347 } else { 348 emit_insn(ctx, amxorw, src, t1, t3); 349 emit_zext_32(ctx, src, true); 350 } 351 break; 352 /* src = atomic_xchg(dst + off, src); */ 353 case BPF_XCHG: 354 if (isdw) { 355 emit_insn(ctx, amswapd, src, t1, t3); 356 } else { 357 emit_insn(ctx, amswapw, src, t1, t3); 358 emit_zext_32(ctx, src, true); 359 } 360 break; 361 /* r0 = atomic_cmpxchg(dst + off, r0, src); */ 362 case BPF_CMPXCHG: 363 move_reg(ctx, t2, r0); 364 if (isdw) { 365 emit_insn(ctx, lld, r0, t1, 0); 366 emit_insn(ctx, bne, t2, r0, 4); 367 move_reg(ctx, t3, src); 368 emit_insn(ctx, scd, t3, t1, 0); 369 emit_insn(ctx, beq, t3, LOONGARCH_GPR_ZERO, -4); 370 } else { 371 emit_insn(ctx, llw, r0, t1, 0); 372 emit_zext_32(ctx, t2, true); 373 emit_zext_32(ctx, r0, true); 374 emit_insn(ctx, bne, t2, r0, 4); 375 move_reg(ctx, t3, src); 376 emit_insn(ctx, scw, t3, t1, 0); 377 emit_insn(ctx, beq, t3, LOONGARCH_GPR_ZERO, -6); 378 emit_zext_32(ctx, r0, true); 379 } 380 break; 381 } 382 } 383 384 static bool is_signed_bpf_cond(u8 cond) 385 { 386 return cond == BPF_JSGT || cond == BPF_JSLT || 387 cond == BPF_JSGE || cond == BPF_JSLE; 388 } 389 390 #define BPF_FIXUP_REG_MASK GENMASK(31, 27) 391 #define BPF_FIXUP_OFFSET_MASK GENMASK(26, 0) 392 393 bool ex_handler_bpf(const struct exception_table_entry *ex, 394 struct pt_regs *regs) 395 { 396 int dst_reg = FIELD_GET(BPF_FIXUP_REG_MASK, ex->fixup); 397 off_t offset = FIELD_GET(BPF_FIXUP_OFFSET_MASK, ex->fixup); 398 399 regs->regs[dst_reg] = 0; 400 regs->csr_era = (unsigned long)&ex->fixup - offset; 401 402 return true; 403 } 404 405 /* For accesses to BTF pointers, add an entry to the exception table */ 406 static int add_exception_handler(const struct bpf_insn *insn, 407 struct jit_ctx *ctx, 408 int dst_reg) 409 { 410 unsigned long pc; 411 off_t offset; 412 struct exception_table_entry *ex; 413 414 if (!ctx->image || !ctx->prog->aux->extable) 415 return 0; 416 417 if (BPF_MODE(insn->code) != BPF_PROBE_MEM && 418 BPF_MODE(insn->code) != BPF_PROBE_MEMSX) 419 return 0; 420 421 if (WARN_ON_ONCE(ctx->num_exentries >= ctx->prog->aux->num_exentries)) 422 return -EINVAL; 423 424 ex = &ctx->prog->aux->extable[ctx->num_exentries]; 425 pc = (unsigned long)&ctx->image[ctx->idx - 1]; 426 427 offset = pc - (long)&ex->insn; 428 if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN)) 429 return -ERANGE; 430 431 ex->insn = offset; 432 433 /* 434 * Since the extable follows the program, the fixup offset is always 435 * negative and limited to BPF_JIT_REGION_SIZE. Store a positive value 436 * to keep things simple, and put the destination register in the upper 437 * bits. We don't need to worry about buildtime or runtime sort 438 * modifying the upper bits because the table is already sorted, and 439 * isn't part of the main exception table. 440 */ 441 offset = (long)&ex->fixup - (pc + LOONGARCH_INSN_SIZE); 442 if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, offset)) 443 return -ERANGE; 444 445 ex->type = EX_TYPE_BPF; 446 ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, offset) | FIELD_PREP(BPF_FIXUP_REG_MASK, dst_reg); 447 448 ctx->num_exentries++; 449 450 return 0; 451 } 452 453 static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool extra_pass) 454 { 455 u8 tm = -1; 456 u64 func_addr; 457 bool func_addr_fixed, sign_extend; 458 int i = insn - ctx->prog->insnsi; 459 int ret, jmp_offset; 460 const u8 code = insn->code; 461 const u8 cond = BPF_OP(code); 462 const u8 t1 = LOONGARCH_GPR_T1; 463 const u8 t2 = LOONGARCH_GPR_T2; 464 const u8 src = regmap[insn->src_reg]; 465 const u8 dst = regmap[insn->dst_reg]; 466 const s16 off = insn->off; 467 const s32 imm = insn->imm; 468 const u64 imm64 = (u64)(insn + 1)->imm << 32 | (u32)insn->imm; 469 const bool is32 = BPF_CLASS(insn->code) == BPF_ALU || BPF_CLASS(insn->code) == BPF_JMP32; 470 471 switch (code) { 472 /* dst = src */ 473 case BPF_ALU | BPF_MOV | BPF_X: 474 case BPF_ALU64 | BPF_MOV | BPF_X: 475 switch (off) { 476 case 0: 477 move_reg(ctx, dst, src); 478 emit_zext_32(ctx, dst, is32); 479 break; 480 case 8: 481 move_reg(ctx, t1, src); 482 emit_insn(ctx, extwb, dst, t1); 483 emit_zext_32(ctx, dst, is32); 484 break; 485 case 16: 486 move_reg(ctx, t1, src); 487 emit_insn(ctx, extwh, dst, t1); 488 emit_zext_32(ctx, dst, is32); 489 break; 490 case 32: 491 emit_insn(ctx, addw, dst, src, LOONGARCH_GPR_ZERO); 492 break; 493 } 494 break; 495 496 /* dst = imm */ 497 case BPF_ALU | BPF_MOV | BPF_K: 498 case BPF_ALU64 | BPF_MOV | BPF_K: 499 move_imm(ctx, dst, imm, is32); 500 break; 501 502 /* dst = dst + src */ 503 case BPF_ALU | BPF_ADD | BPF_X: 504 case BPF_ALU64 | BPF_ADD | BPF_X: 505 emit_insn(ctx, addd, dst, dst, src); 506 emit_zext_32(ctx, dst, is32); 507 break; 508 509 /* dst = dst + imm */ 510 case BPF_ALU | BPF_ADD | BPF_K: 511 case BPF_ALU64 | BPF_ADD | BPF_K: 512 if (is_signed_imm12(imm)) { 513 emit_insn(ctx, addid, dst, dst, imm); 514 } else { 515 move_imm(ctx, t1, imm, is32); 516 emit_insn(ctx, addd, dst, dst, t1); 517 } 518 emit_zext_32(ctx, dst, is32); 519 break; 520 521 /* dst = dst - src */ 522 case BPF_ALU | BPF_SUB | BPF_X: 523 case BPF_ALU64 | BPF_SUB | BPF_X: 524 emit_insn(ctx, subd, dst, dst, src); 525 emit_zext_32(ctx, dst, is32); 526 break; 527 528 /* dst = dst - imm */ 529 case BPF_ALU | BPF_SUB | BPF_K: 530 case BPF_ALU64 | BPF_SUB | BPF_K: 531 if (is_signed_imm12(-imm)) { 532 emit_insn(ctx, addid, dst, dst, -imm); 533 } else { 534 move_imm(ctx, t1, imm, is32); 535 emit_insn(ctx, subd, dst, dst, t1); 536 } 537 emit_zext_32(ctx, dst, is32); 538 break; 539 540 /* dst = dst * src */ 541 case BPF_ALU | BPF_MUL | BPF_X: 542 case BPF_ALU64 | BPF_MUL | BPF_X: 543 emit_insn(ctx, muld, dst, dst, src); 544 emit_zext_32(ctx, dst, is32); 545 break; 546 547 /* dst = dst * imm */ 548 case BPF_ALU | BPF_MUL | BPF_K: 549 case BPF_ALU64 | BPF_MUL | BPF_K: 550 move_imm(ctx, t1, imm, is32); 551 emit_insn(ctx, muld, dst, dst, t1); 552 emit_zext_32(ctx, dst, is32); 553 break; 554 555 /* dst = dst / src */ 556 case BPF_ALU | BPF_DIV | BPF_X: 557 case BPF_ALU64 | BPF_DIV | BPF_X: 558 if (!off) { 559 emit_zext_32(ctx, dst, is32); 560 move_reg(ctx, t1, src); 561 emit_zext_32(ctx, t1, is32); 562 emit_insn(ctx, divdu, dst, dst, t1); 563 emit_zext_32(ctx, dst, is32); 564 } else { 565 emit_sext_32(ctx, dst, is32); 566 move_reg(ctx, t1, src); 567 emit_sext_32(ctx, t1, is32); 568 emit_insn(ctx, divd, dst, dst, t1); 569 emit_sext_32(ctx, dst, is32); 570 } 571 break; 572 573 /* dst = dst / imm */ 574 case BPF_ALU | BPF_DIV | BPF_K: 575 case BPF_ALU64 | BPF_DIV | BPF_K: 576 if (!off) { 577 move_imm(ctx, t1, imm, is32); 578 emit_zext_32(ctx, dst, is32); 579 emit_insn(ctx, divdu, dst, dst, t1); 580 emit_zext_32(ctx, dst, is32); 581 } else { 582 move_imm(ctx, t1, imm, false); 583 emit_sext_32(ctx, t1, is32); 584 emit_sext_32(ctx, dst, is32); 585 emit_insn(ctx, divd, dst, dst, t1); 586 emit_sext_32(ctx, dst, is32); 587 } 588 break; 589 590 /* dst = dst % src */ 591 case BPF_ALU | BPF_MOD | BPF_X: 592 case BPF_ALU64 | BPF_MOD | BPF_X: 593 if (!off) { 594 emit_zext_32(ctx, dst, is32); 595 move_reg(ctx, t1, src); 596 emit_zext_32(ctx, t1, is32); 597 emit_insn(ctx, moddu, dst, dst, t1); 598 emit_zext_32(ctx, dst, is32); 599 } else { 600 emit_sext_32(ctx, dst, is32); 601 move_reg(ctx, t1, src); 602 emit_sext_32(ctx, t1, is32); 603 emit_insn(ctx, modd, dst, dst, t1); 604 emit_sext_32(ctx, dst, is32); 605 } 606 break; 607 608 /* dst = dst % imm */ 609 case BPF_ALU | BPF_MOD | BPF_K: 610 case BPF_ALU64 | BPF_MOD | BPF_K: 611 if (!off) { 612 move_imm(ctx, t1, imm, is32); 613 emit_zext_32(ctx, dst, is32); 614 emit_insn(ctx, moddu, dst, dst, t1); 615 emit_zext_32(ctx, dst, is32); 616 } else { 617 move_imm(ctx, t1, imm, false); 618 emit_sext_32(ctx, t1, is32); 619 emit_sext_32(ctx, dst, is32); 620 emit_insn(ctx, modd, dst, dst, t1); 621 emit_sext_32(ctx, dst, is32); 622 } 623 break; 624 625 /* dst = -dst */ 626 case BPF_ALU | BPF_NEG: 627 case BPF_ALU64 | BPF_NEG: 628 move_imm(ctx, t1, imm, is32); 629 emit_insn(ctx, subd, dst, LOONGARCH_GPR_ZERO, dst); 630 emit_zext_32(ctx, dst, is32); 631 break; 632 633 /* dst = dst & src */ 634 case BPF_ALU | BPF_AND | BPF_X: 635 case BPF_ALU64 | BPF_AND | BPF_X: 636 emit_insn(ctx, and, dst, dst, src); 637 emit_zext_32(ctx, dst, is32); 638 break; 639 640 /* dst = dst & imm */ 641 case BPF_ALU | BPF_AND | BPF_K: 642 case BPF_ALU64 | BPF_AND | BPF_K: 643 if (is_unsigned_imm12(imm)) { 644 emit_insn(ctx, andi, dst, dst, imm); 645 } else { 646 move_imm(ctx, t1, imm, is32); 647 emit_insn(ctx, and, dst, dst, t1); 648 } 649 emit_zext_32(ctx, dst, is32); 650 break; 651 652 /* dst = dst | src */ 653 case BPF_ALU | BPF_OR | BPF_X: 654 case BPF_ALU64 | BPF_OR | BPF_X: 655 emit_insn(ctx, or, dst, dst, src); 656 emit_zext_32(ctx, dst, is32); 657 break; 658 659 /* dst = dst | imm */ 660 case BPF_ALU | BPF_OR | BPF_K: 661 case BPF_ALU64 | BPF_OR | BPF_K: 662 if (is_unsigned_imm12(imm)) { 663 emit_insn(ctx, ori, dst, dst, imm); 664 } else { 665 move_imm(ctx, t1, imm, is32); 666 emit_insn(ctx, or, dst, dst, t1); 667 } 668 emit_zext_32(ctx, dst, is32); 669 break; 670 671 /* dst = dst ^ src */ 672 case BPF_ALU | BPF_XOR | BPF_X: 673 case BPF_ALU64 | BPF_XOR | BPF_X: 674 emit_insn(ctx, xor, dst, dst, src); 675 emit_zext_32(ctx, dst, is32); 676 break; 677 678 /* dst = dst ^ imm */ 679 case BPF_ALU | BPF_XOR | BPF_K: 680 case BPF_ALU64 | BPF_XOR | BPF_K: 681 if (is_unsigned_imm12(imm)) { 682 emit_insn(ctx, xori, dst, dst, imm); 683 } else { 684 move_imm(ctx, t1, imm, is32); 685 emit_insn(ctx, xor, dst, dst, t1); 686 } 687 emit_zext_32(ctx, dst, is32); 688 break; 689 690 /* dst = dst << src (logical) */ 691 case BPF_ALU | BPF_LSH | BPF_X: 692 emit_insn(ctx, sllw, dst, dst, src); 693 emit_zext_32(ctx, dst, is32); 694 break; 695 696 case BPF_ALU64 | BPF_LSH | BPF_X: 697 emit_insn(ctx, slld, dst, dst, src); 698 break; 699 700 /* dst = dst << imm (logical) */ 701 case BPF_ALU | BPF_LSH | BPF_K: 702 emit_insn(ctx, slliw, dst, dst, imm); 703 emit_zext_32(ctx, dst, is32); 704 break; 705 706 case BPF_ALU64 | BPF_LSH | BPF_K: 707 emit_insn(ctx, sllid, dst, dst, imm); 708 break; 709 710 /* dst = dst >> src (logical) */ 711 case BPF_ALU | BPF_RSH | BPF_X: 712 emit_insn(ctx, srlw, dst, dst, src); 713 emit_zext_32(ctx, dst, is32); 714 break; 715 716 case BPF_ALU64 | BPF_RSH | BPF_X: 717 emit_insn(ctx, srld, dst, dst, src); 718 break; 719 720 /* dst = dst >> imm (logical) */ 721 case BPF_ALU | BPF_RSH | BPF_K: 722 emit_insn(ctx, srliw, dst, dst, imm); 723 emit_zext_32(ctx, dst, is32); 724 break; 725 726 case BPF_ALU64 | BPF_RSH | BPF_K: 727 emit_insn(ctx, srlid, dst, dst, imm); 728 break; 729 730 /* dst = dst >> src (arithmetic) */ 731 case BPF_ALU | BPF_ARSH | BPF_X: 732 emit_insn(ctx, sraw, dst, dst, src); 733 emit_zext_32(ctx, dst, is32); 734 break; 735 736 case BPF_ALU64 | BPF_ARSH | BPF_X: 737 emit_insn(ctx, srad, dst, dst, src); 738 break; 739 740 /* dst = dst >> imm (arithmetic) */ 741 case BPF_ALU | BPF_ARSH | BPF_K: 742 emit_insn(ctx, sraiw, dst, dst, imm); 743 emit_zext_32(ctx, dst, is32); 744 break; 745 746 case BPF_ALU64 | BPF_ARSH | BPF_K: 747 emit_insn(ctx, sraid, dst, dst, imm); 748 break; 749 750 /* dst = BSWAP##imm(dst) */ 751 case BPF_ALU | BPF_END | BPF_FROM_LE: 752 switch (imm) { 753 case 16: 754 /* zero-extend 16 bits into 64 bits */ 755 emit_insn(ctx, bstrpickd, dst, dst, 15, 0); 756 break; 757 case 32: 758 /* zero-extend 32 bits into 64 bits */ 759 emit_zext_32(ctx, dst, is32); 760 break; 761 case 64: 762 /* do nothing */ 763 break; 764 } 765 break; 766 767 case BPF_ALU | BPF_END | BPF_FROM_BE: 768 case BPF_ALU64 | BPF_END | BPF_FROM_LE: 769 switch (imm) { 770 case 16: 771 emit_insn(ctx, revb2h, dst, dst); 772 /* zero-extend 16 bits into 64 bits */ 773 emit_insn(ctx, bstrpickd, dst, dst, 15, 0); 774 break; 775 case 32: 776 emit_insn(ctx, revb2w, dst, dst); 777 /* clear the upper 32 bits */ 778 emit_zext_32(ctx, dst, true); 779 break; 780 case 64: 781 emit_insn(ctx, revbd, dst, dst); 782 break; 783 } 784 break; 785 786 /* PC += off if dst cond src */ 787 case BPF_JMP | BPF_JEQ | BPF_X: 788 case BPF_JMP | BPF_JNE | BPF_X: 789 case BPF_JMP | BPF_JGT | BPF_X: 790 case BPF_JMP | BPF_JGE | BPF_X: 791 case BPF_JMP | BPF_JLT | BPF_X: 792 case BPF_JMP | BPF_JLE | BPF_X: 793 case BPF_JMP | BPF_JSGT | BPF_X: 794 case BPF_JMP | BPF_JSGE | BPF_X: 795 case BPF_JMP | BPF_JSLT | BPF_X: 796 case BPF_JMP | BPF_JSLE | BPF_X: 797 case BPF_JMP32 | BPF_JEQ | BPF_X: 798 case BPF_JMP32 | BPF_JNE | BPF_X: 799 case BPF_JMP32 | BPF_JGT | BPF_X: 800 case BPF_JMP32 | BPF_JGE | BPF_X: 801 case BPF_JMP32 | BPF_JLT | BPF_X: 802 case BPF_JMP32 | BPF_JLE | BPF_X: 803 case BPF_JMP32 | BPF_JSGT | BPF_X: 804 case BPF_JMP32 | BPF_JSGE | BPF_X: 805 case BPF_JMP32 | BPF_JSLT | BPF_X: 806 case BPF_JMP32 | BPF_JSLE | BPF_X: 807 jmp_offset = bpf2la_offset(i, off, ctx); 808 move_reg(ctx, t1, dst); 809 move_reg(ctx, t2, src); 810 if (is_signed_bpf_cond(BPF_OP(code))) { 811 emit_sext_32(ctx, t1, is32); 812 emit_sext_32(ctx, t2, is32); 813 } else { 814 emit_zext_32(ctx, t1, is32); 815 emit_zext_32(ctx, t2, is32); 816 } 817 if (emit_cond_jmp(ctx, cond, t1, t2, jmp_offset) < 0) 818 goto toofar; 819 break; 820 821 /* PC += off if dst cond imm */ 822 case BPF_JMP | BPF_JEQ | BPF_K: 823 case BPF_JMP | BPF_JNE | BPF_K: 824 case BPF_JMP | BPF_JGT | BPF_K: 825 case BPF_JMP | BPF_JGE | BPF_K: 826 case BPF_JMP | BPF_JLT | BPF_K: 827 case BPF_JMP | BPF_JLE | BPF_K: 828 case BPF_JMP | BPF_JSGT | BPF_K: 829 case BPF_JMP | BPF_JSGE | BPF_K: 830 case BPF_JMP | BPF_JSLT | BPF_K: 831 case BPF_JMP | BPF_JSLE | BPF_K: 832 case BPF_JMP32 | BPF_JEQ | BPF_K: 833 case BPF_JMP32 | BPF_JNE | BPF_K: 834 case BPF_JMP32 | BPF_JGT | BPF_K: 835 case BPF_JMP32 | BPF_JGE | BPF_K: 836 case BPF_JMP32 | BPF_JLT | BPF_K: 837 case BPF_JMP32 | BPF_JLE | BPF_K: 838 case BPF_JMP32 | BPF_JSGT | BPF_K: 839 case BPF_JMP32 | BPF_JSGE | BPF_K: 840 case BPF_JMP32 | BPF_JSLT | BPF_K: 841 case BPF_JMP32 | BPF_JSLE | BPF_K: 842 jmp_offset = bpf2la_offset(i, off, ctx); 843 if (imm) { 844 move_imm(ctx, t1, imm, false); 845 tm = t1; 846 } else { 847 /* If imm is 0, simply use zero register. */ 848 tm = LOONGARCH_GPR_ZERO; 849 } 850 move_reg(ctx, t2, dst); 851 if (is_signed_bpf_cond(BPF_OP(code))) { 852 emit_sext_32(ctx, tm, is32); 853 emit_sext_32(ctx, t2, is32); 854 } else { 855 emit_zext_32(ctx, tm, is32); 856 emit_zext_32(ctx, t2, is32); 857 } 858 if (emit_cond_jmp(ctx, cond, t2, tm, jmp_offset) < 0) 859 goto toofar; 860 break; 861 862 /* PC += off if dst & src */ 863 case BPF_JMP | BPF_JSET | BPF_X: 864 case BPF_JMP32 | BPF_JSET | BPF_X: 865 jmp_offset = bpf2la_offset(i, off, ctx); 866 emit_insn(ctx, and, t1, dst, src); 867 emit_zext_32(ctx, t1, is32); 868 if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0) 869 goto toofar; 870 break; 871 872 /* PC += off if dst & imm */ 873 case BPF_JMP | BPF_JSET | BPF_K: 874 case BPF_JMP32 | BPF_JSET | BPF_K: 875 jmp_offset = bpf2la_offset(i, off, ctx); 876 move_imm(ctx, t1, imm, is32); 877 emit_insn(ctx, and, t1, dst, t1); 878 emit_zext_32(ctx, t1, is32); 879 if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0) 880 goto toofar; 881 break; 882 883 /* PC += off */ 884 case BPF_JMP | BPF_JA: 885 case BPF_JMP32 | BPF_JA: 886 if (BPF_CLASS(code) == BPF_JMP) 887 jmp_offset = bpf2la_offset(i, off, ctx); 888 else 889 jmp_offset = bpf2la_offset(i, imm, ctx); 890 if (emit_uncond_jmp(ctx, jmp_offset) < 0) 891 goto toofar; 892 break; 893 894 /* function call */ 895 case BPF_JMP | BPF_CALL: 896 mark_call(ctx); 897 ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, 898 &func_addr, &func_addr_fixed); 899 if (ret < 0) 900 return ret; 901 902 move_addr(ctx, t1, func_addr); 903 emit_insn(ctx, jirl, t1, LOONGARCH_GPR_RA, 0); 904 move_reg(ctx, regmap[BPF_REG_0], LOONGARCH_GPR_A0); 905 break; 906 907 /* tail call */ 908 case BPF_JMP | BPF_TAIL_CALL: 909 mark_tail_call(ctx); 910 if (emit_bpf_tail_call(ctx) < 0) 911 return -EINVAL; 912 break; 913 914 /* function return */ 915 case BPF_JMP | BPF_EXIT: 916 if (i == ctx->prog->len - 1) 917 break; 918 919 jmp_offset = epilogue_offset(ctx); 920 if (emit_uncond_jmp(ctx, jmp_offset) < 0) 921 goto toofar; 922 break; 923 924 /* dst = imm64 */ 925 case BPF_LD | BPF_IMM | BPF_DW: 926 move_imm(ctx, dst, imm64, is32); 927 return 1; 928 929 /* dst = *(size *)(src + off) */ 930 case BPF_LDX | BPF_MEM | BPF_B: 931 case BPF_LDX | BPF_MEM | BPF_H: 932 case BPF_LDX | BPF_MEM | BPF_W: 933 case BPF_LDX | BPF_MEM | BPF_DW: 934 case BPF_LDX | BPF_PROBE_MEM | BPF_DW: 935 case BPF_LDX | BPF_PROBE_MEM | BPF_W: 936 case BPF_LDX | BPF_PROBE_MEM | BPF_H: 937 case BPF_LDX | BPF_PROBE_MEM | BPF_B: 938 /* dst_reg = (s64)*(signed size *)(src_reg + off) */ 939 case BPF_LDX | BPF_MEMSX | BPF_B: 940 case BPF_LDX | BPF_MEMSX | BPF_H: 941 case BPF_LDX | BPF_MEMSX | BPF_W: 942 case BPF_LDX | BPF_PROBE_MEMSX | BPF_B: 943 case BPF_LDX | BPF_PROBE_MEMSX | BPF_H: 944 case BPF_LDX | BPF_PROBE_MEMSX | BPF_W: 945 sign_extend = BPF_MODE(insn->code) == BPF_MEMSX || 946 BPF_MODE(insn->code) == BPF_PROBE_MEMSX; 947 switch (BPF_SIZE(code)) { 948 case BPF_B: 949 if (is_signed_imm12(off)) { 950 if (sign_extend) 951 emit_insn(ctx, ldb, dst, src, off); 952 else 953 emit_insn(ctx, ldbu, dst, src, off); 954 } else { 955 move_imm(ctx, t1, off, is32); 956 if (sign_extend) 957 emit_insn(ctx, ldxb, dst, src, t1); 958 else 959 emit_insn(ctx, ldxbu, dst, src, t1); 960 } 961 break; 962 case BPF_H: 963 if (is_signed_imm12(off)) { 964 if (sign_extend) 965 emit_insn(ctx, ldh, dst, src, off); 966 else 967 emit_insn(ctx, ldhu, dst, src, off); 968 } else { 969 move_imm(ctx, t1, off, is32); 970 if (sign_extend) 971 emit_insn(ctx, ldxh, dst, src, t1); 972 else 973 emit_insn(ctx, ldxhu, dst, src, t1); 974 } 975 break; 976 case BPF_W: 977 if (is_signed_imm12(off)) { 978 if (sign_extend) 979 emit_insn(ctx, ldw, dst, src, off); 980 else 981 emit_insn(ctx, ldwu, dst, src, off); 982 } else { 983 move_imm(ctx, t1, off, is32); 984 if (sign_extend) 985 emit_insn(ctx, ldxw, dst, src, t1); 986 else 987 emit_insn(ctx, ldxwu, dst, src, t1); 988 } 989 break; 990 case BPF_DW: 991 move_imm(ctx, t1, off, is32); 992 emit_insn(ctx, ldxd, dst, src, t1); 993 break; 994 } 995 996 ret = add_exception_handler(insn, ctx, dst); 997 if (ret) 998 return ret; 999 break; 1000 1001 /* *(size *)(dst + off) = imm */ 1002 case BPF_ST | BPF_MEM | BPF_B: 1003 case BPF_ST | BPF_MEM | BPF_H: 1004 case BPF_ST | BPF_MEM | BPF_W: 1005 case BPF_ST | BPF_MEM | BPF_DW: 1006 switch (BPF_SIZE(code)) { 1007 case BPF_B: 1008 move_imm(ctx, t1, imm, is32); 1009 if (is_signed_imm12(off)) { 1010 emit_insn(ctx, stb, t1, dst, off); 1011 } else { 1012 move_imm(ctx, t2, off, is32); 1013 emit_insn(ctx, stxb, t1, dst, t2); 1014 } 1015 break; 1016 case BPF_H: 1017 move_imm(ctx, t1, imm, is32); 1018 if (is_signed_imm12(off)) { 1019 emit_insn(ctx, sth, t1, dst, off); 1020 } else { 1021 move_imm(ctx, t2, off, is32); 1022 emit_insn(ctx, stxh, t1, dst, t2); 1023 } 1024 break; 1025 case BPF_W: 1026 move_imm(ctx, t1, imm, is32); 1027 if (is_signed_imm12(off)) { 1028 emit_insn(ctx, stw, t1, dst, off); 1029 } else if (is_signed_imm14(off)) { 1030 emit_insn(ctx, stptrw, t1, dst, off); 1031 } else { 1032 move_imm(ctx, t2, off, is32); 1033 emit_insn(ctx, stxw, t1, dst, t2); 1034 } 1035 break; 1036 case BPF_DW: 1037 move_imm(ctx, t1, imm, is32); 1038 if (is_signed_imm12(off)) { 1039 emit_insn(ctx, std, t1, dst, off); 1040 } else if (is_signed_imm14(off)) { 1041 emit_insn(ctx, stptrd, t1, dst, off); 1042 } else { 1043 move_imm(ctx, t2, off, is32); 1044 emit_insn(ctx, stxd, t1, dst, t2); 1045 } 1046 break; 1047 } 1048 break; 1049 1050 /* *(size *)(dst + off) = src */ 1051 case BPF_STX | BPF_MEM | BPF_B: 1052 case BPF_STX | BPF_MEM | BPF_H: 1053 case BPF_STX | BPF_MEM | BPF_W: 1054 case BPF_STX | BPF_MEM | BPF_DW: 1055 switch (BPF_SIZE(code)) { 1056 case BPF_B: 1057 if (is_signed_imm12(off)) { 1058 emit_insn(ctx, stb, src, dst, off); 1059 } else { 1060 move_imm(ctx, t1, off, is32); 1061 emit_insn(ctx, stxb, src, dst, t1); 1062 } 1063 break; 1064 case BPF_H: 1065 if (is_signed_imm12(off)) { 1066 emit_insn(ctx, sth, src, dst, off); 1067 } else { 1068 move_imm(ctx, t1, off, is32); 1069 emit_insn(ctx, stxh, src, dst, t1); 1070 } 1071 break; 1072 case BPF_W: 1073 if (is_signed_imm12(off)) { 1074 emit_insn(ctx, stw, src, dst, off); 1075 } else if (is_signed_imm14(off)) { 1076 emit_insn(ctx, stptrw, src, dst, off); 1077 } else { 1078 move_imm(ctx, t1, off, is32); 1079 emit_insn(ctx, stxw, src, dst, t1); 1080 } 1081 break; 1082 case BPF_DW: 1083 if (is_signed_imm12(off)) { 1084 emit_insn(ctx, std, src, dst, off); 1085 } else if (is_signed_imm14(off)) { 1086 emit_insn(ctx, stptrd, src, dst, off); 1087 } else { 1088 move_imm(ctx, t1, off, is32); 1089 emit_insn(ctx, stxd, src, dst, t1); 1090 } 1091 break; 1092 } 1093 break; 1094 1095 case BPF_STX | BPF_ATOMIC | BPF_W: 1096 case BPF_STX | BPF_ATOMIC | BPF_DW: 1097 emit_atomic(insn, ctx); 1098 break; 1099 1100 /* Speculation barrier */ 1101 case BPF_ST | BPF_NOSPEC: 1102 break; 1103 1104 default: 1105 pr_err("bpf_jit: unknown opcode %02x\n", code); 1106 return -EINVAL; 1107 } 1108 1109 return 0; 1110 1111 toofar: 1112 pr_info_once("bpf_jit: opcode %02x, jump too far\n", code); 1113 return -E2BIG; 1114 } 1115 1116 static int build_body(struct jit_ctx *ctx, bool extra_pass) 1117 { 1118 int i; 1119 const struct bpf_prog *prog = ctx->prog; 1120 1121 for (i = 0; i < prog->len; i++) { 1122 const struct bpf_insn *insn = &prog->insnsi[i]; 1123 int ret; 1124 1125 if (ctx->image == NULL) 1126 ctx->offset[i] = ctx->idx; 1127 1128 ret = build_insn(insn, ctx, extra_pass); 1129 if (ret > 0) { 1130 i++; 1131 if (ctx->image == NULL) 1132 ctx->offset[i] = ctx->idx; 1133 continue; 1134 } 1135 if (ret) 1136 return ret; 1137 } 1138 1139 if (ctx->image == NULL) 1140 ctx->offset[i] = ctx->idx; 1141 1142 return 0; 1143 } 1144 1145 /* Fill space with break instructions */ 1146 static void jit_fill_hole(void *area, unsigned int size) 1147 { 1148 u32 *ptr; 1149 1150 /* We are guaranteed to have aligned memory */ 1151 for (ptr = area; size >= sizeof(u32); size -= sizeof(u32)) 1152 *ptr++ = INSN_BREAK; 1153 } 1154 1155 static int validate_code(struct jit_ctx *ctx) 1156 { 1157 int i; 1158 union loongarch_instruction insn; 1159 1160 for (i = 0; i < ctx->idx; i++) { 1161 insn = ctx->image[i]; 1162 /* Check INSN_BREAK */ 1163 if (insn.word == INSN_BREAK) 1164 return -1; 1165 } 1166 1167 if (WARN_ON_ONCE(ctx->num_exentries != ctx->prog->aux->num_exentries)) 1168 return -1; 1169 1170 return 0; 1171 } 1172 1173 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) 1174 { 1175 bool tmp_blinded = false, extra_pass = false; 1176 u8 *image_ptr; 1177 int image_size, prog_size, extable_size; 1178 struct jit_ctx ctx; 1179 struct jit_data *jit_data; 1180 struct bpf_binary_header *header; 1181 struct bpf_prog *tmp, *orig_prog = prog; 1182 1183 /* 1184 * If BPF JIT was not enabled then we must fall back to 1185 * the interpreter. 1186 */ 1187 if (!prog->jit_requested) 1188 return orig_prog; 1189 1190 tmp = bpf_jit_blind_constants(prog); 1191 /* 1192 * If blinding was requested and we failed during blinding, 1193 * we must fall back to the interpreter. Otherwise, we save 1194 * the new JITed code. 1195 */ 1196 if (IS_ERR(tmp)) 1197 return orig_prog; 1198 1199 if (tmp != prog) { 1200 tmp_blinded = true; 1201 prog = tmp; 1202 } 1203 1204 jit_data = prog->aux->jit_data; 1205 if (!jit_data) { 1206 jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); 1207 if (!jit_data) { 1208 prog = orig_prog; 1209 goto out; 1210 } 1211 prog->aux->jit_data = jit_data; 1212 } 1213 if (jit_data->ctx.offset) { 1214 ctx = jit_data->ctx; 1215 image_ptr = jit_data->image; 1216 header = jit_data->header; 1217 extra_pass = true; 1218 prog_size = sizeof(u32) * ctx.idx; 1219 goto skip_init_ctx; 1220 } 1221 1222 memset(&ctx, 0, sizeof(ctx)); 1223 ctx.prog = prog; 1224 1225 ctx.offset = kvcalloc(prog->len + 1, sizeof(u32), GFP_KERNEL); 1226 if (ctx.offset == NULL) { 1227 prog = orig_prog; 1228 goto out_offset; 1229 } 1230 1231 /* 1. Initial fake pass to compute ctx->idx and set ctx->flags */ 1232 build_prologue(&ctx); 1233 if (build_body(&ctx, extra_pass)) { 1234 prog = orig_prog; 1235 goto out_offset; 1236 } 1237 ctx.epilogue_offset = ctx.idx; 1238 build_epilogue(&ctx); 1239 1240 extable_size = prog->aux->num_exentries * sizeof(struct exception_table_entry); 1241 1242 /* Now we know the actual image size. 1243 * As each LoongArch instruction is of length 32bit, 1244 * we are translating number of JITed intructions into 1245 * the size required to store these JITed code. 1246 */ 1247 prog_size = sizeof(u32) * ctx.idx; 1248 image_size = prog_size + extable_size; 1249 /* Now we know the size of the structure to make */ 1250 header = bpf_jit_binary_alloc(image_size, &image_ptr, 1251 sizeof(u32), jit_fill_hole); 1252 if (header == NULL) { 1253 prog = orig_prog; 1254 goto out_offset; 1255 } 1256 1257 /* 2. Now, the actual pass to generate final JIT code */ 1258 ctx.image = (union loongarch_instruction *)image_ptr; 1259 if (extable_size) 1260 prog->aux->extable = (void *)image_ptr + prog_size; 1261 1262 skip_init_ctx: 1263 ctx.idx = 0; 1264 ctx.num_exentries = 0; 1265 1266 build_prologue(&ctx); 1267 if (build_body(&ctx, extra_pass)) { 1268 bpf_jit_binary_free(header); 1269 prog = orig_prog; 1270 goto out_offset; 1271 } 1272 build_epilogue(&ctx); 1273 1274 /* 3. Extra pass to validate JITed code */ 1275 if (validate_code(&ctx)) { 1276 bpf_jit_binary_free(header); 1277 prog = orig_prog; 1278 goto out_offset; 1279 } 1280 1281 /* And we're done */ 1282 if (bpf_jit_enable > 1) 1283 bpf_jit_dump(prog->len, prog_size, 2, ctx.image); 1284 1285 /* Update the icache */ 1286 flush_icache_range((unsigned long)header, (unsigned long)(ctx.image + ctx.idx)); 1287 1288 if (!prog->is_func || extra_pass) { 1289 if (extra_pass && ctx.idx != jit_data->ctx.idx) { 1290 pr_err_once("multi-func JIT bug %d != %d\n", 1291 ctx.idx, jit_data->ctx.idx); 1292 bpf_jit_binary_free(header); 1293 prog->bpf_func = NULL; 1294 prog->jited = 0; 1295 prog->jited_len = 0; 1296 goto out_offset; 1297 } 1298 bpf_jit_binary_lock_ro(header); 1299 } else { 1300 jit_data->ctx = ctx; 1301 jit_data->image = image_ptr; 1302 jit_data->header = header; 1303 } 1304 prog->jited = 1; 1305 prog->jited_len = prog_size; 1306 prog->bpf_func = (void *)ctx.image; 1307 1308 if (!prog->is_func || extra_pass) { 1309 int i; 1310 1311 /* offset[prog->len] is the size of program */ 1312 for (i = 0; i <= prog->len; i++) 1313 ctx.offset[i] *= LOONGARCH_INSN_SIZE; 1314 bpf_prog_fill_jited_linfo(prog, ctx.offset + 1); 1315 1316 out_offset: 1317 kvfree(ctx.offset); 1318 kfree(jit_data); 1319 prog->aux->jit_data = NULL; 1320 } 1321 1322 out: 1323 if (tmp_blinded) 1324 bpf_jit_prog_release_other(prog, prog == orig_prog ? tmp : orig_prog); 1325 1326 out_offset = -1; 1327 1328 return prog; 1329 } 1330 1331 /* Indicate the JIT backend supports mixing bpf2bpf and tailcalls. */ 1332 bool bpf_jit_supports_subprog_tailcalls(void) 1333 { 1334 return true; 1335 } 1336