1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * BPF JIT compiler for RV32G 4 * 5 * Copyright (c) 2020 Luke Nelson <luke.r.nels@gmail.com> 6 * Copyright (c) 2020 Xi Wang <xi.wang@gmail.com> 7 * 8 * The code is based on the BPF JIT compiler for RV64G by Björn Töpel and 9 * the BPF JIT compiler for 32-bit ARM by Shubham Bansal and Mircea Gherzan. 10 */ 11 12 #include <linux/bpf.h> 13 #include <linux/filter.h> 14 #include "bpf_jit.h" 15 16 /* 17 * Stack layout during BPF program execution: 18 * 19 * high 20 * RV32 fp => +----------+ 21 * | saved ra | 22 * | saved fp | RV32 callee-saved registers 23 * | ... | 24 * +----------+ <= (fp - 4 * NR_SAVED_REGISTERS) 25 * | hi(R6) | 26 * | lo(R6) | 27 * | hi(R7) | JIT scratch space for BPF registers 28 * | lo(R7) | 29 * | ... | 30 * BPF_REG_FP => +----------+ <= (fp - 4 * NR_SAVED_REGISTERS 31 * | | - 4 * BPF_JIT_SCRATCH_REGS) 32 * | | 33 * | ... | BPF program stack 34 * | | 35 * RV32 sp => +----------+ 36 * | | 37 * | ... | Function call stack 38 * | | 39 * +----------+ 40 * low 41 */ 42 43 enum { 44 /* Stack layout - these are offsets from top of JIT scratch space. */ 45 BPF_R6_HI, 46 BPF_R6_LO, 47 BPF_R7_HI, 48 BPF_R7_LO, 49 BPF_R8_HI, 50 BPF_R8_LO, 51 BPF_R9_HI, 52 BPF_R9_LO, 53 BPF_AX_HI, 54 BPF_AX_LO, 55 /* Stack space for BPF_REG_6 through BPF_REG_9 and BPF_REG_AX. */ 56 BPF_JIT_SCRATCH_REGS, 57 }; 58 59 /* Number of callee-saved registers stored to stack: ra, fp, s1--s7. */ 60 #define NR_SAVED_REGISTERS 9 61 62 /* Offset from fp for BPF registers stored on stack. */ 63 #define STACK_OFFSET(k) (-4 - (4 * NR_SAVED_REGISTERS) - (4 * (k))) 64 65 #define TMP_REG_1 (MAX_BPF_JIT_REG + 0) 66 #define TMP_REG_2 (MAX_BPF_JIT_REG + 1) 67 68 #define RV_REG_TCC RV_REG_T6 69 #define RV_REG_TCC_SAVED RV_REG_S7 70 71 static const s8 bpf2rv32[][2] = { 72 /* Return value from in-kernel function, and exit value from eBPF. */ 73 [BPF_REG_0] = {RV_REG_S2, RV_REG_S1}, 74 /* Arguments from eBPF program to in-kernel function. */ 75 [BPF_REG_1] = {RV_REG_A1, RV_REG_A0}, 76 [BPF_REG_2] = {RV_REG_A3, RV_REG_A2}, 77 [BPF_REG_3] = {RV_REG_A5, RV_REG_A4}, 78 [BPF_REG_4] = {RV_REG_A7, RV_REG_A6}, 79 [BPF_REG_5] = {RV_REG_S4, RV_REG_S3}, 80 /* 81 * Callee-saved registers that in-kernel function will preserve. 82 * Stored on the stack. 83 */ 84 [BPF_REG_6] = {STACK_OFFSET(BPF_R6_HI), STACK_OFFSET(BPF_R6_LO)}, 85 [BPF_REG_7] = {STACK_OFFSET(BPF_R7_HI), STACK_OFFSET(BPF_R7_LO)}, 86 [BPF_REG_8] = {STACK_OFFSET(BPF_R8_HI), STACK_OFFSET(BPF_R8_LO)}, 87 [BPF_REG_9] = {STACK_OFFSET(BPF_R9_HI), STACK_OFFSET(BPF_R9_LO)}, 88 /* Read-only frame pointer to access BPF stack. */ 89 [BPF_REG_FP] = {RV_REG_S6, RV_REG_S5}, 90 /* Temporary register for blinding constants. Stored on the stack. */ 91 [BPF_REG_AX] = {STACK_OFFSET(BPF_AX_HI), STACK_OFFSET(BPF_AX_LO)}, 92 /* 93 * Temporary registers used by the JIT to operate on registers stored 94 * on the stack. Save t0 and t1 to be used as temporaries in generated 95 * code. 96 */ 97 [TMP_REG_1] = {RV_REG_T3, RV_REG_T2}, 98 [TMP_REG_2] = {RV_REG_T5, RV_REG_T4}, 99 }; 100 101 static s8 hi(const s8 *r) 102 { 103 return r[0]; 104 } 105 106 static s8 lo(const s8 *r) 107 { 108 return r[1]; 109 } 110 111 static void emit_imm(const s8 rd, s32 imm, struct rv_jit_context *ctx) 112 { 113 u32 upper = (imm + (1 << 11)) >> 12; 114 u32 lower = imm & 0xfff; 115 116 if (upper) { 117 emit(rv_lui(rd, upper), ctx); 118 emit(rv_addi(rd, rd, lower), ctx); 119 } else { 120 emit(rv_addi(rd, RV_REG_ZERO, lower), ctx); 121 } 122 } 123 124 static void emit_imm32(const s8 *rd, s32 imm, struct rv_jit_context *ctx) 125 { 126 /* Emit immediate into lower bits. */ 127 emit_imm(lo(rd), imm, ctx); 128 129 /* Sign-extend into upper bits. */ 130 if (imm >= 0) 131 emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); 132 else 133 emit(rv_addi(hi(rd), RV_REG_ZERO, -1), ctx); 134 } 135 136 static void emit_imm64(const s8 *rd, s32 imm_hi, s32 imm_lo, 137 struct rv_jit_context *ctx) 138 { 139 emit_imm(lo(rd), imm_lo, ctx); 140 emit_imm(hi(rd), imm_hi, ctx); 141 } 142 143 static void __build_epilogue(bool is_tail_call, struct rv_jit_context *ctx) 144 { 145 int stack_adjust = ctx->stack_size; 146 const s8 *r0 = bpf2rv32[BPF_REG_0]; 147 148 /* Set return value if not tail call. */ 149 if (!is_tail_call) { 150 emit(rv_addi(RV_REG_A0, lo(r0), 0), ctx); 151 emit(rv_addi(RV_REG_A1, hi(r0), 0), ctx); 152 } 153 154 /* Restore callee-saved registers. */ 155 emit(rv_lw(RV_REG_RA, stack_adjust - 4, RV_REG_SP), ctx); 156 emit(rv_lw(RV_REG_FP, stack_adjust - 8, RV_REG_SP), ctx); 157 emit(rv_lw(RV_REG_S1, stack_adjust - 12, RV_REG_SP), ctx); 158 emit(rv_lw(RV_REG_S2, stack_adjust - 16, RV_REG_SP), ctx); 159 emit(rv_lw(RV_REG_S3, stack_adjust - 20, RV_REG_SP), ctx); 160 emit(rv_lw(RV_REG_S4, stack_adjust - 24, RV_REG_SP), ctx); 161 emit(rv_lw(RV_REG_S5, stack_adjust - 28, RV_REG_SP), ctx); 162 emit(rv_lw(RV_REG_S6, stack_adjust - 32, RV_REG_SP), ctx); 163 emit(rv_lw(RV_REG_S7, stack_adjust - 36, RV_REG_SP), ctx); 164 165 emit(rv_addi(RV_REG_SP, RV_REG_SP, stack_adjust), ctx); 166 167 if (is_tail_call) { 168 /* 169 * goto *(t0 + 4); 170 * Skips first instruction of prologue which initializes tail 171 * call counter. Assumes t0 contains address of target program, 172 * see emit_bpf_tail_call. 173 */ 174 emit(rv_jalr(RV_REG_ZERO, RV_REG_T0, 4), ctx); 175 } else { 176 emit(rv_jalr(RV_REG_ZERO, RV_REG_RA, 0), ctx); 177 } 178 } 179 180 static bool is_stacked(s8 reg) 181 { 182 return reg < 0; 183 } 184 185 static const s8 *bpf_get_reg64(const s8 *reg, const s8 *tmp, 186 struct rv_jit_context *ctx) 187 { 188 if (is_stacked(hi(reg))) { 189 emit(rv_lw(hi(tmp), hi(reg), RV_REG_FP), ctx); 190 emit(rv_lw(lo(tmp), lo(reg), RV_REG_FP), ctx); 191 reg = tmp; 192 } 193 return reg; 194 } 195 196 static void bpf_put_reg64(const s8 *reg, const s8 *src, 197 struct rv_jit_context *ctx) 198 { 199 if (is_stacked(hi(reg))) { 200 emit(rv_sw(RV_REG_FP, hi(reg), hi(src)), ctx); 201 emit(rv_sw(RV_REG_FP, lo(reg), lo(src)), ctx); 202 } 203 } 204 205 static const s8 *bpf_get_reg32(const s8 *reg, const s8 *tmp, 206 struct rv_jit_context *ctx) 207 { 208 if (is_stacked(lo(reg))) { 209 emit(rv_lw(lo(tmp), lo(reg), RV_REG_FP), ctx); 210 reg = tmp; 211 } 212 return reg; 213 } 214 215 static void bpf_put_reg32(const s8 *reg, const s8 *src, 216 struct rv_jit_context *ctx) 217 { 218 if (is_stacked(lo(reg))) { 219 emit(rv_sw(RV_REG_FP, lo(reg), lo(src)), ctx); 220 if (!ctx->prog->aux->verifier_zext) 221 emit(rv_sw(RV_REG_FP, hi(reg), RV_REG_ZERO), ctx); 222 } else if (!ctx->prog->aux->verifier_zext) { 223 emit(rv_addi(hi(reg), RV_REG_ZERO, 0), ctx); 224 } 225 } 226 227 static void emit_jump_and_link(u8 rd, s32 rvoff, bool force_jalr, 228 struct rv_jit_context *ctx) 229 { 230 s32 upper, lower; 231 232 if (rvoff && is_21b_int(rvoff) && !force_jalr) { 233 emit(rv_jal(rd, rvoff >> 1), ctx); 234 return; 235 } 236 237 upper = (rvoff + (1 << 11)) >> 12; 238 lower = rvoff & 0xfff; 239 emit(rv_auipc(RV_REG_T1, upper), ctx); 240 emit(rv_jalr(rd, RV_REG_T1, lower), ctx); 241 } 242 243 static void emit_alu_i64(const s8 *dst, s32 imm, 244 struct rv_jit_context *ctx, const u8 op) 245 { 246 const s8 *tmp1 = bpf2rv32[TMP_REG_1]; 247 const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); 248 249 switch (op) { 250 case BPF_MOV: 251 emit_imm32(rd, imm, ctx); 252 break; 253 case BPF_AND: 254 if (is_12b_int(imm)) { 255 emit(rv_andi(lo(rd), lo(rd), imm), ctx); 256 } else { 257 emit_imm(RV_REG_T0, imm, ctx); 258 emit(rv_and(lo(rd), lo(rd), RV_REG_T0), ctx); 259 } 260 if (imm >= 0) 261 emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); 262 break; 263 case BPF_OR: 264 if (is_12b_int(imm)) { 265 emit(rv_ori(lo(rd), lo(rd), imm), ctx); 266 } else { 267 emit_imm(RV_REG_T0, imm, ctx); 268 emit(rv_or(lo(rd), lo(rd), RV_REG_T0), ctx); 269 } 270 if (imm < 0) 271 emit(rv_ori(hi(rd), RV_REG_ZERO, -1), ctx); 272 break; 273 case BPF_XOR: 274 if (is_12b_int(imm)) { 275 emit(rv_xori(lo(rd), lo(rd), imm), ctx); 276 } else { 277 emit_imm(RV_REG_T0, imm, ctx); 278 emit(rv_xor(lo(rd), lo(rd), RV_REG_T0), ctx); 279 } 280 if (imm < 0) 281 emit(rv_xori(hi(rd), hi(rd), -1), ctx); 282 break; 283 case BPF_LSH: 284 if (imm >= 32) { 285 emit(rv_slli(hi(rd), lo(rd), imm - 32), ctx); 286 emit(rv_addi(lo(rd), RV_REG_ZERO, 0), ctx); 287 } else if (imm == 0) { 288 /* Do nothing. */ 289 } else { 290 emit(rv_srli(RV_REG_T0, lo(rd), 32 - imm), ctx); 291 emit(rv_slli(hi(rd), hi(rd), imm), ctx); 292 emit(rv_or(hi(rd), RV_REG_T0, hi(rd)), ctx); 293 emit(rv_slli(lo(rd), lo(rd), imm), ctx); 294 } 295 break; 296 case BPF_RSH: 297 if (imm >= 32) { 298 emit(rv_srli(lo(rd), hi(rd), imm - 32), ctx); 299 emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); 300 } else if (imm == 0) { 301 /* Do nothing. */ 302 } else { 303 emit(rv_slli(RV_REG_T0, hi(rd), 32 - imm), ctx); 304 emit(rv_srli(lo(rd), lo(rd), imm), ctx); 305 emit(rv_or(lo(rd), RV_REG_T0, lo(rd)), ctx); 306 emit(rv_srli(hi(rd), hi(rd), imm), ctx); 307 } 308 break; 309 case BPF_ARSH: 310 if (imm >= 32) { 311 emit(rv_srai(lo(rd), hi(rd), imm - 32), ctx); 312 emit(rv_srai(hi(rd), hi(rd), 31), ctx); 313 } else if (imm == 0) { 314 /* Do nothing. */ 315 } else { 316 emit(rv_slli(RV_REG_T0, hi(rd), 32 - imm), ctx); 317 emit(rv_srli(lo(rd), lo(rd), imm), ctx); 318 emit(rv_or(lo(rd), RV_REG_T0, lo(rd)), ctx); 319 emit(rv_srai(hi(rd), hi(rd), imm), ctx); 320 } 321 break; 322 } 323 324 bpf_put_reg64(dst, rd, ctx); 325 } 326 327 static void emit_alu_i32(const s8 *dst, s32 imm, 328 struct rv_jit_context *ctx, const u8 op) 329 { 330 const s8 *tmp1 = bpf2rv32[TMP_REG_1]; 331 const s8 *rd = bpf_get_reg32(dst, tmp1, ctx); 332 333 switch (op) { 334 case BPF_MOV: 335 emit_imm(lo(rd), imm, ctx); 336 break; 337 case BPF_ADD: 338 if (is_12b_int(imm)) { 339 emit(rv_addi(lo(rd), lo(rd), imm), ctx); 340 } else { 341 emit_imm(RV_REG_T0, imm, ctx); 342 emit(rv_add(lo(rd), lo(rd), RV_REG_T0), ctx); 343 } 344 break; 345 case BPF_SUB: 346 if (is_12b_int(-imm)) { 347 emit(rv_addi(lo(rd), lo(rd), -imm), ctx); 348 } else { 349 emit_imm(RV_REG_T0, imm, ctx); 350 emit(rv_sub(lo(rd), lo(rd), RV_REG_T0), ctx); 351 } 352 break; 353 case BPF_AND: 354 if (is_12b_int(imm)) { 355 emit(rv_andi(lo(rd), lo(rd), imm), ctx); 356 } else { 357 emit_imm(RV_REG_T0, imm, ctx); 358 emit(rv_and(lo(rd), lo(rd), RV_REG_T0), ctx); 359 } 360 break; 361 case BPF_OR: 362 if (is_12b_int(imm)) { 363 emit(rv_ori(lo(rd), lo(rd), imm), ctx); 364 } else { 365 emit_imm(RV_REG_T0, imm, ctx); 366 emit(rv_or(lo(rd), lo(rd), RV_REG_T0), ctx); 367 } 368 break; 369 case BPF_XOR: 370 if (is_12b_int(imm)) { 371 emit(rv_xori(lo(rd), lo(rd), imm), ctx); 372 } else { 373 emit_imm(RV_REG_T0, imm, ctx); 374 emit(rv_xor(lo(rd), lo(rd), RV_REG_T0), ctx); 375 } 376 break; 377 case BPF_LSH: 378 if (is_12b_int(imm)) { 379 emit(rv_slli(lo(rd), lo(rd), imm), ctx); 380 } else { 381 emit_imm(RV_REG_T0, imm, ctx); 382 emit(rv_sll(lo(rd), lo(rd), RV_REG_T0), ctx); 383 } 384 break; 385 case BPF_RSH: 386 if (is_12b_int(imm)) { 387 emit(rv_srli(lo(rd), lo(rd), imm), ctx); 388 } else { 389 emit_imm(RV_REG_T0, imm, ctx); 390 emit(rv_srl(lo(rd), lo(rd), RV_REG_T0), ctx); 391 } 392 break; 393 case BPF_ARSH: 394 if (is_12b_int(imm)) { 395 emit(rv_srai(lo(rd), lo(rd), imm), ctx); 396 } else { 397 emit_imm(RV_REG_T0, imm, ctx); 398 emit(rv_sra(lo(rd), lo(rd), RV_REG_T0), ctx); 399 } 400 break; 401 } 402 403 bpf_put_reg32(dst, rd, ctx); 404 } 405 406 static void emit_alu_r64(const s8 *dst, const s8 *src, 407 struct rv_jit_context *ctx, const u8 op) 408 { 409 const s8 *tmp1 = bpf2rv32[TMP_REG_1]; 410 const s8 *tmp2 = bpf2rv32[TMP_REG_2]; 411 const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); 412 const s8 *rs = bpf_get_reg64(src, tmp2, ctx); 413 414 switch (op) { 415 case BPF_MOV: 416 emit(rv_addi(lo(rd), lo(rs), 0), ctx); 417 emit(rv_addi(hi(rd), hi(rs), 0), ctx); 418 break; 419 case BPF_ADD: 420 if (rd == rs) { 421 emit(rv_srli(RV_REG_T0, lo(rd), 31), ctx); 422 emit(rv_slli(hi(rd), hi(rd), 1), ctx); 423 emit(rv_or(hi(rd), RV_REG_T0, hi(rd)), ctx); 424 emit(rv_slli(lo(rd), lo(rd), 1), ctx); 425 } else { 426 emit(rv_add(lo(rd), lo(rd), lo(rs)), ctx); 427 emit(rv_sltu(RV_REG_T0, lo(rd), lo(rs)), ctx); 428 emit(rv_add(hi(rd), hi(rd), hi(rs)), ctx); 429 emit(rv_add(hi(rd), hi(rd), RV_REG_T0), ctx); 430 } 431 break; 432 case BPF_SUB: 433 emit(rv_sub(RV_REG_T1, hi(rd), hi(rs)), ctx); 434 emit(rv_sltu(RV_REG_T0, lo(rd), lo(rs)), ctx); 435 emit(rv_sub(hi(rd), RV_REG_T1, RV_REG_T0), ctx); 436 emit(rv_sub(lo(rd), lo(rd), lo(rs)), ctx); 437 break; 438 case BPF_AND: 439 emit(rv_and(lo(rd), lo(rd), lo(rs)), ctx); 440 emit(rv_and(hi(rd), hi(rd), hi(rs)), ctx); 441 break; 442 case BPF_OR: 443 emit(rv_or(lo(rd), lo(rd), lo(rs)), ctx); 444 emit(rv_or(hi(rd), hi(rd), hi(rs)), ctx); 445 break; 446 case BPF_XOR: 447 emit(rv_xor(lo(rd), lo(rd), lo(rs)), ctx); 448 emit(rv_xor(hi(rd), hi(rd), hi(rs)), ctx); 449 break; 450 case BPF_MUL: 451 emit(rv_mul(RV_REG_T0, hi(rs), lo(rd)), ctx); 452 emit(rv_mul(hi(rd), hi(rd), lo(rs)), ctx); 453 emit(rv_mulhu(RV_REG_T1, lo(rd), lo(rs)), ctx); 454 emit(rv_add(hi(rd), hi(rd), RV_REG_T0), ctx); 455 emit(rv_mul(lo(rd), lo(rd), lo(rs)), ctx); 456 emit(rv_add(hi(rd), hi(rd), RV_REG_T1), ctx); 457 break; 458 case BPF_LSH: 459 emit(rv_addi(RV_REG_T0, lo(rs), -32), ctx); 460 emit(rv_blt(RV_REG_T0, RV_REG_ZERO, 8), ctx); 461 emit(rv_sll(hi(rd), lo(rd), RV_REG_T0), ctx); 462 emit(rv_addi(lo(rd), RV_REG_ZERO, 0), ctx); 463 emit(rv_jal(RV_REG_ZERO, 16), ctx); 464 emit(rv_addi(RV_REG_T1, RV_REG_ZERO, 31), ctx); 465 emit(rv_srli(RV_REG_T0, lo(rd), 1), ctx); 466 emit(rv_sub(RV_REG_T1, RV_REG_T1, lo(rs)), ctx); 467 emit(rv_srl(RV_REG_T0, RV_REG_T0, RV_REG_T1), ctx); 468 emit(rv_sll(hi(rd), hi(rd), lo(rs)), ctx); 469 emit(rv_or(hi(rd), RV_REG_T0, hi(rd)), ctx); 470 emit(rv_sll(lo(rd), lo(rd), lo(rs)), ctx); 471 break; 472 case BPF_RSH: 473 emit(rv_addi(RV_REG_T0, lo(rs), -32), ctx); 474 emit(rv_blt(RV_REG_T0, RV_REG_ZERO, 8), ctx); 475 emit(rv_srl(lo(rd), hi(rd), RV_REG_T0), ctx); 476 emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); 477 emit(rv_jal(RV_REG_ZERO, 16), ctx); 478 emit(rv_addi(RV_REG_T1, RV_REG_ZERO, 31), ctx); 479 emit(rv_slli(RV_REG_T0, hi(rd), 1), ctx); 480 emit(rv_sub(RV_REG_T1, RV_REG_T1, lo(rs)), ctx); 481 emit(rv_sll(RV_REG_T0, RV_REG_T0, RV_REG_T1), ctx); 482 emit(rv_srl(lo(rd), lo(rd), lo(rs)), ctx); 483 emit(rv_or(lo(rd), RV_REG_T0, lo(rd)), ctx); 484 emit(rv_srl(hi(rd), hi(rd), lo(rs)), ctx); 485 break; 486 case BPF_ARSH: 487 emit(rv_addi(RV_REG_T0, lo(rs), -32), ctx); 488 emit(rv_blt(RV_REG_T0, RV_REG_ZERO, 8), ctx); 489 emit(rv_sra(lo(rd), hi(rd), RV_REG_T0), ctx); 490 emit(rv_srai(hi(rd), hi(rd), 31), ctx); 491 emit(rv_jal(RV_REG_ZERO, 16), ctx); 492 emit(rv_addi(RV_REG_T1, RV_REG_ZERO, 31), ctx); 493 emit(rv_slli(RV_REG_T0, hi(rd), 1), ctx); 494 emit(rv_sub(RV_REG_T1, RV_REG_T1, lo(rs)), ctx); 495 emit(rv_sll(RV_REG_T0, RV_REG_T0, RV_REG_T1), ctx); 496 emit(rv_srl(lo(rd), lo(rd), lo(rs)), ctx); 497 emit(rv_or(lo(rd), RV_REG_T0, lo(rd)), ctx); 498 emit(rv_sra(hi(rd), hi(rd), lo(rs)), ctx); 499 break; 500 case BPF_NEG: 501 emit(rv_sub(lo(rd), RV_REG_ZERO, lo(rd)), ctx); 502 emit(rv_sltu(RV_REG_T0, RV_REG_ZERO, lo(rd)), ctx); 503 emit(rv_sub(hi(rd), RV_REG_ZERO, hi(rd)), ctx); 504 emit(rv_sub(hi(rd), hi(rd), RV_REG_T0), ctx); 505 break; 506 } 507 508 bpf_put_reg64(dst, rd, ctx); 509 } 510 511 static void emit_alu_r32(const s8 *dst, const s8 *src, 512 struct rv_jit_context *ctx, const u8 op) 513 { 514 const s8 *tmp1 = bpf2rv32[TMP_REG_1]; 515 const s8 *tmp2 = bpf2rv32[TMP_REG_2]; 516 const s8 *rd = bpf_get_reg32(dst, tmp1, ctx); 517 const s8 *rs = bpf_get_reg32(src, tmp2, ctx); 518 519 switch (op) { 520 case BPF_MOV: 521 emit(rv_addi(lo(rd), lo(rs), 0), ctx); 522 break; 523 case BPF_ADD: 524 emit(rv_add(lo(rd), lo(rd), lo(rs)), ctx); 525 break; 526 case BPF_SUB: 527 emit(rv_sub(lo(rd), lo(rd), lo(rs)), ctx); 528 break; 529 case BPF_AND: 530 emit(rv_and(lo(rd), lo(rd), lo(rs)), ctx); 531 break; 532 case BPF_OR: 533 emit(rv_or(lo(rd), lo(rd), lo(rs)), ctx); 534 break; 535 case BPF_XOR: 536 emit(rv_xor(lo(rd), lo(rd), lo(rs)), ctx); 537 break; 538 case BPF_MUL: 539 emit(rv_mul(lo(rd), lo(rd), lo(rs)), ctx); 540 break; 541 case BPF_DIV: 542 emit(rv_divu(lo(rd), lo(rd), lo(rs)), ctx); 543 break; 544 case BPF_MOD: 545 emit(rv_remu(lo(rd), lo(rd), lo(rs)), ctx); 546 break; 547 case BPF_LSH: 548 emit(rv_sll(lo(rd), lo(rd), lo(rs)), ctx); 549 break; 550 case BPF_RSH: 551 emit(rv_srl(lo(rd), lo(rd), lo(rs)), ctx); 552 break; 553 case BPF_ARSH: 554 emit(rv_sra(lo(rd), lo(rd), lo(rs)), ctx); 555 break; 556 case BPF_NEG: 557 emit(rv_sub(lo(rd), RV_REG_ZERO, lo(rd)), ctx); 558 break; 559 } 560 561 bpf_put_reg32(dst, rd, ctx); 562 } 563 564 static int emit_branch_r64(const s8 *src1, const s8 *src2, s32 rvoff, 565 struct rv_jit_context *ctx, const u8 op) 566 { 567 int e, s = ctx->ninsns; 568 const s8 *tmp1 = bpf2rv32[TMP_REG_1]; 569 const s8 *tmp2 = bpf2rv32[TMP_REG_2]; 570 571 const s8 *rs1 = bpf_get_reg64(src1, tmp1, ctx); 572 const s8 *rs2 = bpf_get_reg64(src2, tmp2, ctx); 573 574 /* 575 * NO_JUMP skips over the rest of the instructions and the 576 * emit_jump_and_link, meaning the BPF branch is not taken. 577 * JUMP skips directly to the emit_jump_and_link, meaning 578 * the BPF branch is taken. 579 * 580 * The fallthrough case results in the BPF branch being taken. 581 */ 582 #define NO_JUMP(idx) (6 + (2 * (idx))) 583 #define JUMP(idx) (2 + (2 * (idx))) 584 585 switch (op) { 586 case BPF_JEQ: 587 emit(rv_bne(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); 588 emit(rv_bne(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); 589 break; 590 case BPF_JGT: 591 emit(rv_bgtu(hi(rs1), hi(rs2), JUMP(2)), ctx); 592 emit(rv_bltu(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); 593 emit(rv_bleu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); 594 break; 595 case BPF_JLT: 596 emit(rv_bltu(hi(rs1), hi(rs2), JUMP(2)), ctx); 597 emit(rv_bgtu(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); 598 emit(rv_bgeu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); 599 break; 600 case BPF_JGE: 601 emit(rv_bgtu(hi(rs1), hi(rs2), JUMP(2)), ctx); 602 emit(rv_bltu(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); 603 emit(rv_bltu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); 604 break; 605 case BPF_JLE: 606 emit(rv_bltu(hi(rs1), hi(rs2), JUMP(2)), ctx); 607 emit(rv_bgtu(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); 608 emit(rv_bgtu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); 609 break; 610 case BPF_JNE: 611 emit(rv_bne(hi(rs1), hi(rs2), JUMP(1)), ctx); 612 emit(rv_beq(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); 613 break; 614 case BPF_JSGT: 615 emit(rv_bgt(hi(rs1), hi(rs2), JUMP(2)), ctx); 616 emit(rv_blt(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); 617 emit(rv_bleu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); 618 break; 619 case BPF_JSLT: 620 emit(rv_blt(hi(rs1), hi(rs2), JUMP(2)), ctx); 621 emit(rv_bgt(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); 622 emit(rv_bgeu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); 623 break; 624 case BPF_JSGE: 625 emit(rv_bgt(hi(rs1), hi(rs2), JUMP(2)), ctx); 626 emit(rv_blt(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); 627 emit(rv_bltu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); 628 break; 629 case BPF_JSLE: 630 emit(rv_blt(hi(rs1), hi(rs2), JUMP(2)), ctx); 631 emit(rv_bgt(hi(rs1), hi(rs2), NO_JUMP(1)), ctx); 632 emit(rv_bgtu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx); 633 break; 634 case BPF_JSET: 635 emit(rv_and(RV_REG_T0, hi(rs1), hi(rs2)), ctx); 636 emit(rv_bne(RV_REG_T0, RV_REG_ZERO, JUMP(2)), ctx); 637 emit(rv_and(RV_REG_T0, lo(rs1), lo(rs2)), ctx); 638 emit(rv_beq(RV_REG_T0, RV_REG_ZERO, NO_JUMP(0)), ctx); 639 break; 640 } 641 642 #undef NO_JUMP 643 #undef JUMP 644 645 e = ctx->ninsns; 646 /* Adjust for extra insns. */ 647 rvoff -= ninsns_rvoff(e - s); 648 emit_jump_and_link(RV_REG_ZERO, rvoff, true, ctx); 649 return 0; 650 } 651 652 static int emit_bcc(u8 op, u8 rd, u8 rs, int rvoff, struct rv_jit_context *ctx) 653 { 654 int e, s = ctx->ninsns; 655 bool far = false; 656 int off; 657 658 if (op == BPF_JSET) { 659 /* 660 * BPF_JSET is a special case: it has no inverse so we always 661 * treat it as a far branch. 662 */ 663 far = true; 664 } else if (!is_13b_int(rvoff)) { 665 op = invert_bpf_cond(op); 666 far = true; 667 } 668 669 /* 670 * For a far branch, the condition is negated and we jump over the 671 * branch itself, and the two instructions from emit_jump_and_link. 672 * For a near branch, just use rvoff. 673 */ 674 off = far ? 6 : (rvoff >> 1); 675 676 switch (op) { 677 case BPF_JEQ: 678 emit(rv_beq(rd, rs, off), ctx); 679 break; 680 case BPF_JGT: 681 emit(rv_bgtu(rd, rs, off), ctx); 682 break; 683 case BPF_JLT: 684 emit(rv_bltu(rd, rs, off), ctx); 685 break; 686 case BPF_JGE: 687 emit(rv_bgeu(rd, rs, off), ctx); 688 break; 689 case BPF_JLE: 690 emit(rv_bleu(rd, rs, off), ctx); 691 break; 692 case BPF_JNE: 693 emit(rv_bne(rd, rs, off), ctx); 694 break; 695 case BPF_JSGT: 696 emit(rv_bgt(rd, rs, off), ctx); 697 break; 698 case BPF_JSLT: 699 emit(rv_blt(rd, rs, off), ctx); 700 break; 701 case BPF_JSGE: 702 emit(rv_bge(rd, rs, off), ctx); 703 break; 704 case BPF_JSLE: 705 emit(rv_ble(rd, rs, off), ctx); 706 break; 707 case BPF_JSET: 708 emit(rv_and(RV_REG_T0, rd, rs), ctx); 709 emit(rv_beq(RV_REG_T0, RV_REG_ZERO, off), ctx); 710 break; 711 } 712 713 if (far) { 714 e = ctx->ninsns; 715 /* Adjust for extra insns. */ 716 rvoff -= ninsns_rvoff(e - s); 717 emit_jump_and_link(RV_REG_ZERO, rvoff, true, ctx); 718 } 719 return 0; 720 } 721 722 static int emit_branch_r32(const s8 *src1, const s8 *src2, s32 rvoff, 723 struct rv_jit_context *ctx, const u8 op) 724 { 725 int e, s = ctx->ninsns; 726 const s8 *tmp1 = bpf2rv32[TMP_REG_1]; 727 const s8 *tmp2 = bpf2rv32[TMP_REG_2]; 728 729 const s8 *rs1 = bpf_get_reg32(src1, tmp1, ctx); 730 const s8 *rs2 = bpf_get_reg32(src2, tmp2, ctx); 731 732 e = ctx->ninsns; 733 /* Adjust for extra insns. */ 734 rvoff -= ninsns_rvoff(e - s); 735 736 if (emit_bcc(op, lo(rs1), lo(rs2), rvoff, ctx)) 737 return -1; 738 739 return 0; 740 } 741 742 static void emit_call(bool fixed, u64 addr, struct rv_jit_context *ctx) 743 { 744 const s8 *r0 = bpf2rv32[BPF_REG_0]; 745 const s8 *r5 = bpf2rv32[BPF_REG_5]; 746 u32 upper = ((u32)addr + (1 << 11)) >> 12; 747 u32 lower = addr & 0xfff; 748 749 /* R1-R4 already in correct registers---need to push R5 to stack. */ 750 emit(rv_addi(RV_REG_SP, RV_REG_SP, -16), ctx); 751 emit(rv_sw(RV_REG_SP, 0, lo(r5)), ctx); 752 emit(rv_sw(RV_REG_SP, 4, hi(r5)), ctx); 753 754 /* Backup TCC. */ 755 emit(rv_addi(RV_REG_TCC_SAVED, RV_REG_TCC, 0), ctx); 756 757 /* 758 * Use lui/jalr pair to jump to absolute address. Don't use emit_imm as 759 * the number of emitted instructions should not depend on the value of 760 * addr. 761 */ 762 emit(rv_lui(RV_REG_T1, upper), ctx); 763 emit(rv_jalr(RV_REG_RA, RV_REG_T1, lower), ctx); 764 765 /* Restore TCC. */ 766 emit(rv_addi(RV_REG_TCC, RV_REG_TCC_SAVED, 0), ctx); 767 768 /* Set return value and restore stack. */ 769 emit(rv_addi(lo(r0), RV_REG_A0, 0), ctx); 770 emit(rv_addi(hi(r0), RV_REG_A1, 0), ctx); 771 emit(rv_addi(RV_REG_SP, RV_REG_SP, 16), ctx); 772 } 773 774 static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx) 775 { 776 /* 777 * R1 -> &ctx 778 * R2 -> &array 779 * R3 -> index 780 */ 781 int tc_ninsn, off, start_insn = ctx->ninsns; 782 const s8 *arr_reg = bpf2rv32[BPF_REG_2]; 783 const s8 *idx_reg = bpf2rv32[BPF_REG_3]; 784 785 tc_ninsn = insn ? ctx->offset[insn] - ctx->offset[insn - 1] : 786 ctx->offset[0]; 787 788 /* max_entries = array->map.max_entries; */ 789 off = offsetof(struct bpf_array, map.max_entries); 790 if (is_12b_check(off, insn)) 791 return -1; 792 emit(rv_lw(RV_REG_T1, off, lo(arr_reg)), ctx); 793 794 /* 795 * if (index >= max_entries) 796 * goto out; 797 */ 798 off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); 799 emit_bcc(BPF_JGE, lo(idx_reg), RV_REG_T1, off, ctx); 800 801 /* 802 * if (--tcc < 0) 803 * goto out; 804 */ 805 emit(rv_addi(RV_REG_TCC, RV_REG_TCC, -1), ctx); 806 off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); 807 emit_bcc(BPF_JSLT, RV_REG_TCC, RV_REG_ZERO, off, ctx); 808 809 /* 810 * prog = array->ptrs[index]; 811 * if (!prog) 812 * goto out; 813 */ 814 emit(rv_slli(RV_REG_T0, lo(idx_reg), 2), ctx); 815 emit(rv_add(RV_REG_T0, RV_REG_T0, lo(arr_reg)), ctx); 816 off = offsetof(struct bpf_array, ptrs); 817 if (is_12b_check(off, insn)) 818 return -1; 819 emit(rv_lw(RV_REG_T0, off, RV_REG_T0), ctx); 820 off = ninsns_rvoff(tc_ninsn - (ctx->ninsns - start_insn)); 821 emit_bcc(BPF_JEQ, RV_REG_T0, RV_REG_ZERO, off, ctx); 822 823 /* 824 * tcc = temp_tcc; 825 * goto *(prog->bpf_func + 4); 826 */ 827 off = offsetof(struct bpf_prog, bpf_func); 828 if (is_12b_check(off, insn)) 829 return -1; 830 emit(rv_lw(RV_REG_T0, off, RV_REG_T0), ctx); 831 /* Epilogue jumps to *(t0 + 4). */ 832 __build_epilogue(true, ctx); 833 return 0; 834 } 835 836 static int emit_load_r64(const s8 *dst, const s8 *src, s16 off, 837 struct rv_jit_context *ctx, const u8 size) 838 { 839 const s8 *tmp1 = bpf2rv32[TMP_REG_1]; 840 const s8 *tmp2 = bpf2rv32[TMP_REG_2]; 841 const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); 842 const s8 *rs = bpf_get_reg64(src, tmp2, ctx); 843 844 emit_imm(RV_REG_T0, off, ctx); 845 emit(rv_add(RV_REG_T0, RV_REG_T0, lo(rs)), ctx); 846 847 switch (size) { 848 case BPF_B: 849 emit(rv_lbu(lo(rd), 0, RV_REG_T0), ctx); 850 if (!ctx->prog->aux->verifier_zext) 851 emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); 852 break; 853 case BPF_H: 854 emit(rv_lhu(lo(rd), 0, RV_REG_T0), ctx); 855 if (!ctx->prog->aux->verifier_zext) 856 emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); 857 break; 858 case BPF_W: 859 emit(rv_lw(lo(rd), 0, RV_REG_T0), ctx); 860 if (!ctx->prog->aux->verifier_zext) 861 emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); 862 break; 863 case BPF_DW: 864 emit(rv_lw(lo(rd), 0, RV_REG_T0), ctx); 865 emit(rv_lw(hi(rd), 4, RV_REG_T0), ctx); 866 break; 867 } 868 869 bpf_put_reg64(dst, rd, ctx); 870 return 0; 871 } 872 873 static int emit_store_r64(const s8 *dst, const s8 *src, s16 off, 874 struct rv_jit_context *ctx, const u8 size, 875 const u8 mode) 876 { 877 const s8 *tmp1 = bpf2rv32[TMP_REG_1]; 878 const s8 *tmp2 = bpf2rv32[TMP_REG_2]; 879 const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); 880 const s8 *rs = bpf_get_reg64(src, tmp2, ctx); 881 882 if (mode == BPF_ATOMIC && size != BPF_W) 883 return -1; 884 885 emit_imm(RV_REG_T0, off, ctx); 886 emit(rv_add(RV_REG_T0, RV_REG_T0, lo(rd)), ctx); 887 888 switch (size) { 889 case BPF_B: 890 emit(rv_sb(RV_REG_T0, 0, lo(rs)), ctx); 891 break; 892 case BPF_H: 893 emit(rv_sh(RV_REG_T0, 0, lo(rs)), ctx); 894 break; 895 case BPF_W: 896 switch (mode) { 897 case BPF_MEM: 898 emit(rv_sw(RV_REG_T0, 0, lo(rs)), ctx); 899 break; 900 case BPF_ATOMIC: /* Only BPF_ADD supported */ 901 emit(rv_amoadd_w(RV_REG_ZERO, lo(rs), RV_REG_T0, 0, 0), 902 ctx); 903 break; 904 } 905 break; 906 case BPF_DW: 907 emit(rv_sw(RV_REG_T0, 0, lo(rs)), ctx); 908 emit(rv_sw(RV_REG_T0, 4, hi(rs)), ctx); 909 break; 910 } 911 912 return 0; 913 } 914 915 static void emit_rev16(const s8 rd, struct rv_jit_context *ctx) 916 { 917 emit(rv_slli(rd, rd, 16), ctx); 918 emit(rv_slli(RV_REG_T1, rd, 8), ctx); 919 emit(rv_srli(rd, rd, 8), ctx); 920 emit(rv_add(RV_REG_T1, rd, RV_REG_T1), ctx); 921 emit(rv_srli(rd, RV_REG_T1, 16), ctx); 922 } 923 924 static void emit_rev32(const s8 rd, struct rv_jit_context *ctx) 925 { 926 emit(rv_addi(RV_REG_T1, RV_REG_ZERO, 0), ctx); 927 emit(rv_andi(RV_REG_T0, rd, 255), ctx); 928 emit(rv_add(RV_REG_T1, RV_REG_T1, RV_REG_T0), ctx); 929 emit(rv_slli(RV_REG_T1, RV_REG_T1, 8), ctx); 930 emit(rv_srli(rd, rd, 8), ctx); 931 emit(rv_andi(RV_REG_T0, rd, 255), ctx); 932 emit(rv_add(RV_REG_T1, RV_REG_T1, RV_REG_T0), ctx); 933 emit(rv_slli(RV_REG_T1, RV_REG_T1, 8), ctx); 934 emit(rv_srli(rd, rd, 8), ctx); 935 emit(rv_andi(RV_REG_T0, rd, 255), ctx); 936 emit(rv_add(RV_REG_T1, RV_REG_T1, RV_REG_T0), ctx); 937 emit(rv_slli(RV_REG_T1, RV_REG_T1, 8), ctx); 938 emit(rv_srli(rd, rd, 8), ctx); 939 emit(rv_andi(RV_REG_T0, rd, 255), ctx); 940 emit(rv_add(RV_REG_T1, RV_REG_T1, RV_REG_T0), ctx); 941 emit(rv_addi(rd, RV_REG_T1, 0), ctx); 942 } 943 944 static void emit_zext64(const s8 *dst, struct rv_jit_context *ctx) 945 { 946 const s8 *rd; 947 const s8 *tmp1 = bpf2rv32[TMP_REG_1]; 948 949 rd = bpf_get_reg64(dst, tmp1, ctx); 950 emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); 951 bpf_put_reg64(dst, rd, ctx); 952 } 953 954 int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, 955 bool extra_pass) 956 { 957 bool is64 = BPF_CLASS(insn->code) == BPF_ALU64 || 958 BPF_CLASS(insn->code) == BPF_JMP; 959 int s, e, rvoff, i = insn - ctx->prog->insnsi; 960 u8 code = insn->code; 961 s16 off = insn->off; 962 s32 imm = insn->imm; 963 964 const s8 *dst = bpf2rv32[insn->dst_reg]; 965 const s8 *src = bpf2rv32[insn->src_reg]; 966 const s8 *tmp1 = bpf2rv32[TMP_REG_1]; 967 const s8 *tmp2 = bpf2rv32[TMP_REG_2]; 968 969 switch (code) { 970 case BPF_ALU64 | BPF_MOV | BPF_X: 971 972 case BPF_ALU64 | BPF_ADD | BPF_X: 973 case BPF_ALU64 | BPF_ADD | BPF_K: 974 975 case BPF_ALU64 | BPF_SUB | BPF_X: 976 case BPF_ALU64 | BPF_SUB | BPF_K: 977 978 case BPF_ALU64 | BPF_AND | BPF_X: 979 case BPF_ALU64 | BPF_OR | BPF_X: 980 case BPF_ALU64 | BPF_XOR | BPF_X: 981 982 case BPF_ALU64 | BPF_MUL | BPF_X: 983 case BPF_ALU64 | BPF_MUL | BPF_K: 984 985 case BPF_ALU64 | BPF_LSH | BPF_X: 986 case BPF_ALU64 | BPF_RSH | BPF_X: 987 case BPF_ALU64 | BPF_ARSH | BPF_X: 988 if (BPF_SRC(code) == BPF_K) { 989 emit_imm32(tmp2, imm, ctx); 990 src = tmp2; 991 } 992 emit_alu_r64(dst, src, ctx, BPF_OP(code)); 993 break; 994 995 case BPF_ALU64 | BPF_NEG: 996 emit_alu_r64(dst, tmp2, ctx, BPF_OP(code)); 997 break; 998 999 case BPF_ALU64 | BPF_DIV | BPF_X: 1000 case BPF_ALU64 | BPF_DIV | BPF_K: 1001 case BPF_ALU64 | BPF_MOD | BPF_X: 1002 case BPF_ALU64 | BPF_MOD | BPF_K: 1003 goto notsupported; 1004 1005 case BPF_ALU64 | BPF_MOV | BPF_K: 1006 case BPF_ALU64 | BPF_AND | BPF_K: 1007 case BPF_ALU64 | BPF_OR | BPF_K: 1008 case BPF_ALU64 | BPF_XOR | BPF_K: 1009 case BPF_ALU64 | BPF_LSH | BPF_K: 1010 case BPF_ALU64 | BPF_RSH | BPF_K: 1011 case BPF_ALU64 | BPF_ARSH | BPF_K: 1012 emit_alu_i64(dst, imm, ctx, BPF_OP(code)); 1013 break; 1014 1015 case BPF_ALU | BPF_MOV | BPF_X: 1016 if (imm == 1) { 1017 /* Special mov32 for zext. */ 1018 emit_zext64(dst, ctx); 1019 break; 1020 } 1021 fallthrough; 1022 1023 case BPF_ALU | BPF_ADD | BPF_X: 1024 case BPF_ALU | BPF_SUB | BPF_X: 1025 case BPF_ALU | BPF_AND | BPF_X: 1026 case BPF_ALU | BPF_OR | BPF_X: 1027 case BPF_ALU | BPF_XOR | BPF_X: 1028 1029 case BPF_ALU | BPF_MUL | BPF_X: 1030 case BPF_ALU | BPF_MUL | BPF_K: 1031 1032 case BPF_ALU | BPF_DIV | BPF_X: 1033 case BPF_ALU | BPF_DIV | BPF_K: 1034 1035 case BPF_ALU | BPF_MOD | BPF_X: 1036 case BPF_ALU | BPF_MOD | BPF_K: 1037 1038 case BPF_ALU | BPF_LSH | BPF_X: 1039 case BPF_ALU | BPF_RSH | BPF_X: 1040 case BPF_ALU | BPF_ARSH | BPF_X: 1041 if (BPF_SRC(code) == BPF_K) { 1042 emit_imm32(tmp2, imm, ctx); 1043 src = tmp2; 1044 } 1045 emit_alu_r32(dst, src, ctx, BPF_OP(code)); 1046 break; 1047 1048 case BPF_ALU | BPF_MOV | BPF_K: 1049 case BPF_ALU | BPF_ADD | BPF_K: 1050 case BPF_ALU | BPF_SUB | BPF_K: 1051 case BPF_ALU | BPF_AND | BPF_K: 1052 case BPF_ALU | BPF_OR | BPF_K: 1053 case BPF_ALU | BPF_XOR | BPF_K: 1054 case BPF_ALU | BPF_LSH | BPF_K: 1055 case BPF_ALU | BPF_RSH | BPF_K: 1056 case BPF_ALU | BPF_ARSH | BPF_K: 1057 /* 1058 * mul,div,mod are handled in the BPF_X case since there are 1059 * no RISC-V I-type equivalents. 1060 */ 1061 emit_alu_i32(dst, imm, ctx, BPF_OP(code)); 1062 break; 1063 1064 case BPF_ALU | BPF_NEG: 1065 /* 1066 * src is ignored---choose tmp2 as a dummy register since it 1067 * is not on the stack. 1068 */ 1069 emit_alu_r32(dst, tmp2, ctx, BPF_OP(code)); 1070 break; 1071 1072 case BPF_ALU | BPF_END | BPF_FROM_LE: 1073 { 1074 const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); 1075 1076 switch (imm) { 1077 case 16: 1078 emit(rv_slli(lo(rd), lo(rd), 16), ctx); 1079 emit(rv_srli(lo(rd), lo(rd), 16), ctx); 1080 fallthrough; 1081 case 32: 1082 if (!ctx->prog->aux->verifier_zext) 1083 emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); 1084 break; 1085 case 64: 1086 /* Do nothing. */ 1087 break; 1088 default: 1089 pr_err("bpf-jit: BPF_END imm %d invalid\n", imm); 1090 return -1; 1091 } 1092 1093 bpf_put_reg64(dst, rd, ctx); 1094 break; 1095 } 1096 1097 case BPF_ALU | BPF_END | BPF_FROM_BE: 1098 { 1099 const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); 1100 1101 switch (imm) { 1102 case 16: 1103 emit_rev16(lo(rd), ctx); 1104 if (!ctx->prog->aux->verifier_zext) 1105 emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); 1106 break; 1107 case 32: 1108 emit_rev32(lo(rd), ctx); 1109 if (!ctx->prog->aux->verifier_zext) 1110 emit(rv_addi(hi(rd), RV_REG_ZERO, 0), ctx); 1111 break; 1112 case 64: 1113 /* Swap upper and lower halves. */ 1114 emit(rv_addi(RV_REG_T0, lo(rd), 0), ctx); 1115 emit(rv_addi(lo(rd), hi(rd), 0), ctx); 1116 emit(rv_addi(hi(rd), RV_REG_T0, 0), ctx); 1117 1118 /* Swap each half. */ 1119 emit_rev32(lo(rd), ctx); 1120 emit_rev32(hi(rd), ctx); 1121 break; 1122 default: 1123 pr_err("bpf-jit: BPF_END imm %d invalid\n", imm); 1124 return -1; 1125 } 1126 1127 bpf_put_reg64(dst, rd, ctx); 1128 break; 1129 } 1130 1131 case BPF_JMP | BPF_JA: 1132 rvoff = rv_offset(i, off, ctx); 1133 emit_jump_and_link(RV_REG_ZERO, rvoff, false, ctx); 1134 break; 1135 1136 case BPF_JMP | BPF_CALL: 1137 { 1138 bool fixed; 1139 int ret; 1140 u64 addr; 1141 1142 ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, &addr, 1143 &fixed); 1144 if (ret < 0) 1145 return ret; 1146 emit_call(fixed, addr, ctx); 1147 break; 1148 } 1149 1150 case BPF_JMP | BPF_TAIL_CALL: 1151 if (emit_bpf_tail_call(i, ctx)) 1152 return -1; 1153 break; 1154 1155 case BPF_JMP | BPF_JEQ | BPF_X: 1156 case BPF_JMP | BPF_JEQ | BPF_K: 1157 case BPF_JMP32 | BPF_JEQ | BPF_X: 1158 case BPF_JMP32 | BPF_JEQ | BPF_K: 1159 1160 case BPF_JMP | BPF_JNE | BPF_X: 1161 case BPF_JMP | BPF_JNE | BPF_K: 1162 case BPF_JMP32 | BPF_JNE | BPF_X: 1163 case BPF_JMP32 | BPF_JNE | BPF_K: 1164 1165 case BPF_JMP | BPF_JLE | BPF_X: 1166 case BPF_JMP | BPF_JLE | BPF_K: 1167 case BPF_JMP32 | BPF_JLE | BPF_X: 1168 case BPF_JMP32 | BPF_JLE | BPF_K: 1169 1170 case BPF_JMP | BPF_JLT | BPF_X: 1171 case BPF_JMP | BPF_JLT | BPF_K: 1172 case BPF_JMP32 | BPF_JLT | BPF_X: 1173 case BPF_JMP32 | BPF_JLT | BPF_K: 1174 1175 case BPF_JMP | BPF_JGE | BPF_X: 1176 case BPF_JMP | BPF_JGE | BPF_K: 1177 case BPF_JMP32 | BPF_JGE | BPF_X: 1178 case BPF_JMP32 | BPF_JGE | BPF_K: 1179 1180 case BPF_JMP | BPF_JGT | BPF_X: 1181 case BPF_JMP | BPF_JGT | BPF_K: 1182 case BPF_JMP32 | BPF_JGT | BPF_X: 1183 case BPF_JMP32 | BPF_JGT | BPF_K: 1184 1185 case BPF_JMP | BPF_JSLE | BPF_X: 1186 case BPF_JMP | BPF_JSLE | BPF_K: 1187 case BPF_JMP32 | BPF_JSLE | BPF_X: 1188 case BPF_JMP32 | BPF_JSLE | BPF_K: 1189 1190 case BPF_JMP | BPF_JSLT | BPF_X: 1191 case BPF_JMP | BPF_JSLT | BPF_K: 1192 case BPF_JMP32 | BPF_JSLT | BPF_X: 1193 case BPF_JMP32 | BPF_JSLT | BPF_K: 1194 1195 case BPF_JMP | BPF_JSGE | BPF_X: 1196 case BPF_JMP | BPF_JSGE | BPF_K: 1197 case BPF_JMP32 | BPF_JSGE | BPF_X: 1198 case BPF_JMP32 | BPF_JSGE | BPF_K: 1199 1200 case BPF_JMP | BPF_JSGT | BPF_X: 1201 case BPF_JMP | BPF_JSGT | BPF_K: 1202 case BPF_JMP32 | BPF_JSGT | BPF_X: 1203 case BPF_JMP32 | BPF_JSGT | BPF_K: 1204 1205 case BPF_JMP | BPF_JSET | BPF_X: 1206 case BPF_JMP | BPF_JSET | BPF_K: 1207 case BPF_JMP32 | BPF_JSET | BPF_X: 1208 case BPF_JMP32 | BPF_JSET | BPF_K: 1209 rvoff = rv_offset(i, off, ctx); 1210 if (BPF_SRC(code) == BPF_K) { 1211 s = ctx->ninsns; 1212 emit_imm32(tmp2, imm, ctx); 1213 src = tmp2; 1214 e = ctx->ninsns; 1215 rvoff -= ninsns_rvoff(e - s); 1216 } 1217 1218 if (is64) 1219 emit_branch_r64(dst, src, rvoff, ctx, BPF_OP(code)); 1220 else 1221 emit_branch_r32(dst, src, rvoff, ctx, BPF_OP(code)); 1222 break; 1223 1224 case BPF_JMP | BPF_EXIT: 1225 if (i == ctx->prog->len - 1) 1226 break; 1227 1228 rvoff = epilogue_offset(ctx); 1229 emit_jump_and_link(RV_REG_ZERO, rvoff, false, ctx); 1230 break; 1231 1232 case BPF_LD | BPF_IMM | BPF_DW: 1233 { 1234 struct bpf_insn insn1 = insn[1]; 1235 s32 imm_lo = imm; 1236 s32 imm_hi = insn1.imm; 1237 const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); 1238 1239 emit_imm64(rd, imm_hi, imm_lo, ctx); 1240 bpf_put_reg64(dst, rd, ctx); 1241 return 1; 1242 } 1243 1244 case BPF_LDX | BPF_MEM | BPF_B: 1245 case BPF_LDX | BPF_MEM | BPF_H: 1246 case BPF_LDX | BPF_MEM | BPF_W: 1247 case BPF_LDX | BPF_MEM | BPF_DW: 1248 if (emit_load_r64(dst, src, off, ctx, BPF_SIZE(code))) 1249 return -1; 1250 break; 1251 1252 /* speculation barrier */ 1253 case BPF_ST | BPF_NOSPEC: 1254 break; 1255 1256 case BPF_ST | BPF_MEM | BPF_B: 1257 case BPF_ST | BPF_MEM | BPF_H: 1258 case BPF_ST | BPF_MEM | BPF_W: 1259 case BPF_ST | BPF_MEM | BPF_DW: 1260 1261 case BPF_STX | BPF_MEM | BPF_B: 1262 case BPF_STX | BPF_MEM | BPF_H: 1263 case BPF_STX | BPF_MEM | BPF_W: 1264 case BPF_STX | BPF_MEM | BPF_DW: 1265 if (BPF_CLASS(code) == BPF_ST) { 1266 emit_imm32(tmp2, imm, ctx); 1267 src = tmp2; 1268 } 1269 1270 if (emit_store_r64(dst, src, off, ctx, BPF_SIZE(code), 1271 BPF_MODE(code))) 1272 return -1; 1273 break; 1274 1275 case BPF_STX | BPF_ATOMIC | BPF_W: 1276 if (insn->imm != BPF_ADD) { 1277 pr_info_once( 1278 "bpf-jit: not supported: atomic operation %02x ***\n", 1279 insn->imm); 1280 return -EFAULT; 1281 } 1282 1283 if (emit_store_r64(dst, src, off, ctx, BPF_SIZE(code), 1284 BPF_MODE(code))) 1285 return -1; 1286 break; 1287 1288 /* No hardware support for 8-byte atomics in RV32. */ 1289 case BPF_STX | BPF_ATOMIC | BPF_DW: 1290 /* Fallthrough. */ 1291 1292 notsupported: 1293 pr_info_once("bpf-jit: not supported: opcode %02x ***\n", code); 1294 return -EFAULT; 1295 1296 default: 1297 pr_err("bpf-jit: unknown opcode %02x\n", code); 1298 return -EINVAL; 1299 } 1300 1301 return 0; 1302 } 1303 1304 void bpf_jit_build_prologue(struct rv_jit_context *ctx) 1305 { 1306 const s8 *fp = bpf2rv32[BPF_REG_FP]; 1307 const s8 *r1 = bpf2rv32[BPF_REG_1]; 1308 int stack_adjust = 0; 1309 int bpf_stack_adjust = 1310 round_up(ctx->prog->aux->stack_depth, STACK_ALIGN); 1311 1312 /* Make space for callee-saved registers. */ 1313 stack_adjust += NR_SAVED_REGISTERS * sizeof(u32); 1314 /* Make space for BPF registers on stack. */ 1315 stack_adjust += BPF_JIT_SCRATCH_REGS * sizeof(u32); 1316 /* Make space for BPF stack. */ 1317 stack_adjust += bpf_stack_adjust; 1318 /* Round up for stack alignment. */ 1319 stack_adjust = round_up(stack_adjust, STACK_ALIGN); 1320 1321 /* 1322 * The first instruction sets the tail-call-counter (TCC) register. 1323 * This instruction is skipped by tail calls. 1324 */ 1325 emit(rv_addi(RV_REG_TCC, RV_REG_ZERO, MAX_TAIL_CALL_CNT), ctx); 1326 1327 emit(rv_addi(RV_REG_SP, RV_REG_SP, -stack_adjust), ctx); 1328 1329 /* Save callee-save registers. */ 1330 emit(rv_sw(RV_REG_SP, stack_adjust - 4, RV_REG_RA), ctx); 1331 emit(rv_sw(RV_REG_SP, stack_adjust - 8, RV_REG_FP), ctx); 1332 emit(rv_sw(RV_REG_SP, stack_adjust - 12, RV_REG_S1), ctx); 1333 emit(rv_sw(RV_REG_SP, stack_adjust - 16, RV_REG_S2), ctx); 1334 emit(rv_sw(RV_REG_SP, stack_adjust - 20, RV_REG_S3), ctx); 1335 emit(rv_sw(RV_REG_SP, stack_adjust - 24, RV_REG_S4), ctx); 1336 emit(rv_sw(RV_REG_SP, stack_adjust - 28, RV_REG_S5), ctx); 1337 emit(rv_sw(RV_REG_SP, stack_adjust - 32, RV_REG_S6), ctx); 1338 emit(rv_sw(RV_REG_SP, stack_adjust - 36, RV_REG_S7), ctx); 1339 1340 /* Set fp: used as the base address for stacked BPF registers. */ 1341 emit(rv_addi(RV_REG_FP, RV_REG_SP, stack_adjust), ctx); 1342 1343 /* Set up BPF frame pointer. */ 1344 emit(rv_addi(lo(fp), RV_REG_SP, bpf_stack_adjust), ctx); 1345 emit(rv_addi(hi(fp), RV_REG_ZERO, 0), ctx); 1346 1347 /* Set up BPF context pointer. */ 1348 emit(rv_addi(lo(r1), RV_REG_A0, 0), ctx); 1349 emit(rv_addi(hi(r1), RV_REG_ZERO, 0), ctx); 1350 1351 ctx->stack_size = stack_adjust; 1352 } 1353 1354 void bpf_jit_build_epilogue(struct rv_jit_context *ctx) 1355 { 1356 __build_epilogue(false, ctx); 1357 } 1358