1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * BPF Jit compiler for s390. 4 * 5 * Minimum build requirements: 6 * 7 * - HAVE_MARCH_Z196_FEATURES: laal, laalg 8 * - HAVE_MARCH_Z10_FEATURES: msfi, cgrj, clgrj 9 * - HAVE_MARCH_Z9_109_FEATURES: alfi, llilf, clfi, oilf, nilf 10 * - PACK_STACK 11 * - 64BIT 12 * 13 * Copyright IBM Corp. 2012,2015 14 * 15 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> 16 * Michael Holzheu <holzheu@linux.vnet.ibm.com> 17 */ 18 19 #define KMSG_COMPONENT "bpf_jit" 20 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 21 22 #include <linux/netdevice.h> 23 #include <linux/filter.h> 24 #include <linux/init.h> 25 #include <linux/bpf.h> 26 #include <linux/mm.h> 27 #include <linux/kernel.h> 28 #include <asm/cacheflush.h> 29 #include <asm/dis.h> 30 #include <asm/facility.h> 31 #include <asm/nospec-branch.h> 32 #include <asm/set_memory.h> 33 #include "bpf_jit.h" 34 35 struct bpf_jit { 36 u32 seen; /* Flags to remember seen eBPF instructions */ 37 u32 seen_reg[16]; /* Array to remember which registers are used */ 38 u32 *addrs; /* Array with relative instruction addresses */ 39 u8 *prg_buf; /* Start of program */ 40 int size; /* Size of program and literal pool */ 41 int size_prg; /* Size of program */ 42 int prg; /* Current position in program */ 43 int lit32_start; /* Start of 32-bit literal pool */ 44 int lit32; /* Current position in 32-bit literal pool */ 45 int lit64_start; /* Start of 64-bit literal pool */ 46 int lit64; /* Current position in 64-bit literal pool */ 47 int base_ip; /* Base address for literal pool */ 48 int exit_ip; /* Address of exit */ 49 int r1_thunk_ip; /* Address of expoline thunk for 'br %r1' */ 50 int r14_thunk_ip; /* Address of expoline thunk for 'br %r14' */ 51 int tail_call_start; /* Tail call start offset */ 52 int excnt; /* Number of exception table entries */ 53 }; 54 55 #define SEEN_MEM BIT(0) /* use mem[] for temporary storage */ 56 #define SEEN_LITERAL BIT(1) /* code uses literals */ 57 #define SEEN_FUNC BIT(2) /* calls C functions */ 58 #define SEEN_TAIL_CALL BIT(3) /* code uses tail calls */ 59 #define SEEN_STACK (SEEN_FUNC | SEEN_MEM) 60 61 /* 62 * s390 registers 63 */ 64 #define REG_W0 (MAX_BPF_JIT_REG + 0) /* Work register 1 (even) */ 65 #define REG_W1 (MAX_BPF_JIT_REG + 1) /* Work register 2 (odd) */ 66 #define REG_L (MAX_BPF_JIT_REG + 2) /* Literal pool register */ 67 #define REG_15 (MAX_BPF_JIT_REG + 3) /* Register 15 */ 68 #define REG_0 REG_W0 /* Register 0 */ 69 #define REG_1 REG_W1 /* Register 1 */ 70 #define REG_2 BPF_REG_1 /* Register 2 */ 71 #define REG_14 BPF_REG_0 /* Register 14 */ 72 73 /* 74 * Mapping of BPF registers to s390 registers 75 */ 76 static const int reg2hex[] = { 77 /* Return code */ 78 [BPF_REG_0] = 14, 79 /* Function parameters */ 80 [BPF_REG_1] = 2, 81 [BPF_REG_2] = 3, 82 [BPF_REG_3] = 4, 83 [BPF_REG_4] = 5, 84 [BPF_REG_5] = 6, 85 /* Call saved registers */ 86 [BPF_REG_6] = 7, 87 [BPF_REG_7] = 8, 88 [BPF_REG_8] = 9, 89 [BPF_REG_9] = 10, 90 /* BPF stack pointer */ 91 [BPF_REG_FP] = 13, 92 /* Register for blinding */ 93 [BPF_REG_AX] = 12, 94 /* Work registers for s390x backend */ 95 [REG_W0] = 0, 96 [REG_W1] = 1, 97 [REG_L] = 11, 98 [REG_15] = 15, 99 }; 100 101 static inline u32 reg(u32 dst_reg, u32 src_reg) 102 { 103 return reg2hex[dst_reg] << 4 | reg2hex[src_reg]; 104 } 105 106 static inline u32 reg_high(u32 reg) 107 { 108 return reg2hex[reg] << 4; 109 } 110 111 static inline void reg_set_seen(struct bpf_jit *jit, u32 b1) 112 { 113 u32 r1 = reg2hex[b1]; 114 115 if (!jit->seen_reg[r1] && r1 >= 6 && r1 <= 15) 116 jit->seen_reg[r1] = 1; 117 } 118 119 #define REG_SET_SEEN(b1) \ 120 ({ \ 121 reg_set_seen(jit, b1); \ 122 }) 123 124 #define REG_SEEN(b1) jit->seen_reg[reg2hex[(b1)]] 125 126 /* 127 * EMIT macros for code generation 128 */ 129 130 #define _EMIT2(op) \ 131 ({ \ 132 if (jit->prg_buf) \ 133 *(u16 *) (jit->prg_buf + jit->prg) = (op); \ 134 jit->prg += 2; \ 135 }) 136 137 #define EMIT2(op, b1, b2) \ 138 ({ \ 139 _EMIT2((op) | reg(b1, b2)); \ 140 REG_SET_SEEN(b1); \ 141 REG_SET_SEEN(b2); \ 142 }) 143 144 #define _EMIT4(op) \ 145 ({ \ 146 if (jit->prg_buf) \ 147 *(u32 *) (jit->prg_buf + jit->prg) = (op); \ 148 jit->prg += 4; \ 149 }) 150 151 #define EMIT4(op, b1, b2) \ 152 ({ \ 153 _EMIT4((op) | reg(b1, b2)); \ 154 REG_SET_SEEN(b1); \ 155 REG_SET_SEEN(b2); \ 156 }) 157 158 #define EMIT4_RRF(op, b1, b2, b3) \ 159 ({ \ 160 _EMIT4((op) | reg_high(b3) << 8 | reg(b1, b2)); \ 161 REG_SET_SEEN(b1); \ 162 REG_SET_SEEN(b2); \ 163 REG_SET_SEEN(b3); \ 164 }) 165 166 #define _EMIT4_DISP(op, disp) \ 167 ({ \ 168 unsigned int __disp = (disp) & 0xfff; \ 169 _EMIT4((op) | __disp); \ 170 }) 171 172 #define EMIT4_DISP(op, b1, b2, disp) \ 173 ({ \ 174 _EMIT4_DISP((op) | reg_high(b1) << 16 | \ 175 reg_high(b2) << 8, (disp)); \ 176 REG_SET_SEEN(b1); \ 177 REG_SET_SEEN(b2); \ 178 }) 179 180 #define EMIT4_IMM(op, b1, imm) \ 181 ({ \ 182 unsigned int __imm = (imm) & 0xffff; \ 183 _EMIT4((op) | reg_high(b1) << 16 | __imm); \ 184 REG_SET_SEEN(b1); \ 185 }) 186 187 #define EMIT4_PCREL(op, pcrel) \ 188 ({ \ 189 long __pcrel = ((pcrel) >> 1) & 0xffff; \ 190 _EMIT4((op) | __pcrel); \ 191 }) 192 193 #define EMIT4_PCREL_RIC(op, mask, target) \ 194 ({ \ 195 int __rel = ((target) - jit->prg) / 2; \ 196 _EMIT4((op) | (mask) << 20 | (__rel & 0xffff)); \ 197 }) 198 199 #define _EMIT6(op1, op2) \ 200 ({ \ 201 if (jit->prg_buf) { \ 202 *(u32 *) (jit->prg_buf + jit->prg) = (op1); \ 203 *(u16 *) (jit->prg_buf + jit->prg + 4) = (op2); \ 204 } \ 205 jit->prg += 6; \ 206 }) 207 208 #define _EMIT6_DISP(op1, op2, disp) \ 209 ({ \ 210 unsigned int __disp = (disp) & 0xfff; \ 211 _EMIT6((op1) | __disp, op2); \ 212 }) 213 214 #define _EMIT6_DISP_LH(op1, op2, disp) \ 215 ({ \ 216 u32 _disp = (u32) (disp); \ 217 unsigned int __disp_h = _disp & 0xff000; \ 218 unsigned int __disp_l = _disp & 0x00fff; \ 219 _EMIT6((op1) | __disp_l, (op2) | __disp_h >> 4); \ 220 }) 221 222 #define EMIT6_DISP_LH(op1, op2, b1, b2, b3, disp) \ 223 ({ \ 224 _EMIT6_DISP_LH((op1) | reg(b1, b2) << 16 | \ 225 reg_high(b3) << 8, op2, disp); \ 226 REG_SET_SEEN(b1); \ 227 REG_SET_SEEN(b2); \ 228 REG_SET_SEEN(b3); \ 229 }) 230 231 #define EMIT6_PCREL_RIEB(op1, op2, b1, b2, mask, target) \ 232 ({ \ 233 unsigned int rel = (int)((target) - jit->prg) / 2; \ 234 _EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), \ 235 (op2) | (mask) << 12); \ 236 REG_SET_SEEN(b1); \ 237 REG_SET_SEEN(b2); \ 238 }) 239 240 #define EMIT6_PCREL_RIEC(op1, op2, b1, imm, mask, target) \ 241 ({ \ 242 unsigned int rel = (int)((target) - jit->prg) / 2; \ 243 _EMIT6((op1) | (reg_high(b1) | (mask)) << 16 | \ 244 (rel & 0xffff), (op2) | ((imm) & 0xff) << 8); \ 245 REG_SET_SEEN(b1); \ 246 BUILD_BUG_ON(((unsigned long) (imm)) > 0xff); \ 247 }) 248 249 #define EMIT6_PCREL(op1, op2, b1, b2, i, off, mask) \ 250 ({ \ 251 /* Branch instruction needs 6 bytes */ \ 252 int rel = (addrs[(i) + (off) + 1] - (addrs[(i) + 1] - 6)) / 2;\ 253 _EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), (op2) | (mask));\ 254 REG_SET_SEEN(b1); \ 255 REG_SET_SEEN(b2); \ 256 }) 257 258 #define EMIT6_PCREL_RILB(op, b, target) \ 259 ({ \ 260 unsigned int rel = (int)((target) - jit->prg) / 2; \ 261 _EMIT6((op) | reg_high(b) << 16 | rel >> 16, rel & 0xffff);\ 262 REG_SET_SEEN(b); \ 263 }) 264 265 #define EMIT6_PCREL_RIL(op, target) \ 266 ({ \ 267 unsigned int rel = (int)((target) - jit->prg) / 2; \ 268 _EMIT6((op) | rel >> 16, rel & 0xffff); \ 269 }) 270 271 #define EMIT6_PCREL_RILC(op, mask, target) \ 272 ({ \ 273 EMIT6_PCREL_RIL((op) | (mask) << 20, (target)); \ 274 }) 275 276 #define _EMIT6_IMM(op, imm) \ 277 ({ \ 278 unsigned int __imm = (imm); \ 279 _EMIT6((op) | (__imm >> 16), __imm & 0xffff); \ 280 }) 281 282 #define EMIT6_IMM(op, b1, imm) \ 283 ({ \ 284 _EMIT6_IMM((op) | reg_high(b1) << 16, imm); \ 285 REG_SET_SEEN(b1); \ 286 }) 287 288 #define _EMIT_CONST_U32(val) \ 289 ({ \ 290 unsigned int ret; \ 291 ret = jit->lit32; \ 292 if (jit->prg_buf) \ 293 *(u32 *)(jit->prg_buf + jit->lit32) = (u32)(val);\ 294 jit->lit32 += 4; \ 295 ret; \ 296 }) 297 298 #define EMIT_CONST_U32(val) \ 299 ({ \ 300 jit->seen |= SEEN_LITERAL; \ 301 _EMIT_CONST_U32(val) - jit->base_ip; \ 302 }) 303 304 #define _EMIT_CONST_U64(val) \ 305 ({ \ 306 unsigned int ret; \ 307 ret = jit->lit64; \ 308 if (jit->prg_buf) \ 309 *(u64 *)(jit->prg_buf + jit->lit64) = (u64)(val);\ 310 jit->lit64 += 8; \ 311 ret; \ 312 }) 313 314 #define EMIT_CONST_U64(val) \ 315 ({ \ 316 jit->seen |= SEEN_LITERAL; \ 317 _EMIT_CONST_U64(val) - jit->base_ip; \ 318 }) 319 320 #define EMIT_ZERO(b1) \ 321 ({ \ 322 if (!fp->aux->verifier_zext) { \ 323 /* llgfr %dst,%dst (zero extend to 64 bit) */ \ 324 EMIT4(0xb9160000, b1, b1); \ 325 REG_SET_SEEN(b1); \ 326 } \ 327 }) 328 329 /* 330 * Return whether this is the first pass. The first pass is special, since we 331 * don't know any sizes yet, and thus must be conservative. 332 */ 333 static bool is_first_pass(struct bpf_jit *jit) 334 { 335 return jit->size == 0; 336 } 337 338 /* 339 * Return whether this is the code generation pass. The code generation pass is 340 * special, since we should change as little as possible. 341 */ 342 static bool is_codegen_pass(struct bpf_jit *jit) 343 { 344 return jit->prg_buf; 345 } 346 347 /* 348 * Return whether "rel" can be encoded as a short PC-relative offset 349 */ 350 static bool is_valid_rel(int rel) 351 { 352 return rel >= -65536 && rel <= 65534; 353 } 354 355 /* 356 * Return whether "off" can be reached using a short PC-relative offset 357 */ 358 static bool can_use_rel(struct bpf_jit *jit, int off) 359 { 360 return is_valid_rel(off - jit->prg); 361 } 362 363 /* 364 * Return whether given displacement can be encoded using 365 * Long-Displacement Facility 366 */ 367 static bool is_valid_ldisp(int disp) 368 { 369 return disp >= -524288 && disp <= 524287; 370 } 371 372 /* 373 * Return whether the next 32-bit literal pool entry can be referenced using 374 * Long-Displacement Facility 375 */ 376 static bool can_use_ldisp_for_lit32(struct bpf_jit *jit) 377 { 378 return is_valid_ldisp(jit->lit32 - jit->base_ip); 379 } 380 381 /* 382 * Return whether the next 64-bit literal pool entry can be referenced using 383 * Long-Displacement Facility 384 */ 385 static bool can_use_ldisp_for_lit64(struct bpf_jit *jit) 386 { 387 return is_valid_ldisp(jit->lit64 - jit->base_ip); 388 } 389 390 /* 391 * Fill whole space with illegal instructions 392 */ 393 static void jit_fill_hole(void *area, unsigned int size) 394 { 395 memset(area, 0, size); 396 } 397 398 /* 399 * Save registers from "rs" (register start) to "re" (register end) on stack 400 */ 401 static void save_regs(struct bpf_jit *jit, u32 rs, u32 re) 402 { 403 u32 off = STK_OFF_R6 + (rs - 6) * 8; 404 405 if (rs == re) 406 /* stg %rs,off(%r15) */ 407 _EMIT6(0xe300f000 | rs << 20 | off, 0x0024); 408 else 409 /* stmg %rs,%re,off(%r15) */ 410 _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0024, off); 411 } 412 413 /* 414 * Restore registers from "rs" (register start) to "re" (register end) on stack 415 */ 416 static void restore_regs(struct bpf_jit *jit, u32 rs, u32 re, u32 stack_depth) 417 { 418 u32 off = STK_OFF_R6 + (rs - 6) * 8; 419 420 if (jit->seen & SEEN_STACK) 421 off += STK_OFF + stack_depth; 422 423 if (rs == re) 424 /* lg %rs,off(%r15) */ 425 _EMIT6(0xe300f000 | rs << 20 | off, 0x0004); 426 else 427 /* lmg %rs,%re,off(%r15) */ 428 _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0004, off); 429 } 430 431 /* 432 * Return first seen register (from start) 433 */ 434 static int get_start(struct bpf_jit *jit, int start) 435 { 436 int i; 437 438 for (i = start; i <= 15; i++) { 439 if (jit->seen_reg[i]) 440 return i; 441 } 442 return 0; 443 } 444 445 /* 446 * Return last seen register (from start) (gap >= 2) 447 */ 448 static int get_end(struct bpf_jit *jit, int start) 449 { 450 int i; 451 452 for (i = start; i < 15; i++) { 453 if (!jit->seen_reg[i] && !jit->seen_reg[i + 1]) 454 return i - 1; 455 } 456 return jit->seen_reg[15] ? 15 : 14; 457 } 458 459 #define REGS_SAVE 1 460 #define REGS_RESTORE 0 461 /* 462 * Save and restore clobbered registers (6-15) on stack. 463 * We save/restore registers in chunks with gap >= 2 registers. 464 */ 465 static void save_restore_regs(struct bpf_jit *jit, int op, u32 stack_depth) 466 { 467 const int last = 15, save_restore_size = 6; 468 int re = 6, rs; 469 470 if (is_first_pass(jit)) { 471 /* 472 * We don't know yet which registers are used. Reserve space 473 * conservatively. 474 */ 475 jit->prg += (last - re + 1) * save_restore_size; 476 return; 477 } 478 479 do { 480 rs = get_start(jit, re); 481 if (!rs) 482 break; 483 re = get_end(jit, rs + 1); 484 if (op == REGS_SAVE) 485 save_regs(jit, rs, re); 486 else 487 restore_regs(jit, rs, re, stack_depth); 488 re++; 489 } while (re <= last); 490 } 491 492 static void bpf_skip(struct bpf_jit *jit, int size) 493 { 494 if (size >= 6 && !is_valid_rel(size)) { 495 /* brcl 0xf,size */ 496 EMIT6_PCREL_RIL(0xc0f4000000, size); 497 size -= 6; 498 } else if (size >= 4 && is_valid_rel(size)) { 499 /* brc 0xf,size */ 500 EMIT4_PCREL(0xa7f40000, size); 501 size -= 4; 502 } 503 while (size >= 2) { 504 /* bcr 0,%0 */ 505 _EMIT2(0x0700); 506 size -= 2; 507 } 508 } 509 510 /* 511 * Emit function prologue 512 * 513 * Save registers and create stack frame if necessary. 514 * See stack frame layout desription in "bpf_jit.h"! 515 */ 516 static void bpf_jit_prologue(struct bpf_jit *jit, u32 stack_depth) 517 { 518 if (jit->seen & SEEN_TAIL_CALL) { 519 /* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */ 520 _EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT); 521 } else { 522 /* 523 * There are no tail calls. Insert nops in order to have 524 * tail_call_start at a predictable offset. 525 */ 526 bpf_skip(jit, 6); 527 } 528 /* Tail calls have to skip above initialization */ 529 jit->tail_call_start = jit->prg; 530 /* Save registers */ 531 save_restore_regs(jit, REGS_SAVE, stack_depth); 532 /* Setup literal pool */ 533 if (is_first_pass(jit) || (jit->seen & SEEN_LITERAL)) { 534 if (!is_first_pass(jit) && 535 is_valid_ldisp(jit->size - (jit->prg + 2))) { 536 /* basr %l,0 */ 537 EMIT2(0x0d00, REG_L, REG_0); 538 jit->base_ip = jit->prg; 539 } else { 540 /* larl %l,lit32_start */ 541 EMIT6_PCREL_RILB(0xc0000000, REG_L, jit->lit32_start); 542 jit->base_ip = jit->lit32_start; 543 } 544 } 545 /* Setup stack and backchain */ 546 if (is_first_pass(jit) || (jit->seen & SEEN_STACK)) { 547 if (is_first_pass(jit) || (jit->seen & SEEN_FUNC)) 548 /* lgr %w1,%r15 (backchain) */ 549 EMIT4(0xb9040000, REG_W1, REG_15); 550 /* la %bfp,STK_160_UNUSED(%r15) (BPF frame pointer) */ 551 EMIT4_DISP(0x41000000, BPF_REG_FP, REG_15, STK_160_UNUSED); 552 /* aghi %r15,-STK_OFF */ 553 EMIT4_IMM(0xa70b0000, REG_15, -(STK_OFF + stack_depth)); 554 if (is_first_pass(jit) || (jit->seen & SEEN_FUNC)) 555 /* stg %w1,152(%r15) (backchain) */ 556 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, 557 REG_15, 152); 558 } 559 } 560 561 /* 562 * Function epilogue 563 */ 564 static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth) 565 { 566 jit->exit_ip = jit->prg; 567 /* Load exit code: lgr %r2,%b0 */ 568 EMIT4(0xb9040000, REG_2, BPF_REG_0); 569 /* Restore registers */ 570 save_restore_regs(jit, REGS_RESTORE, stack_depth); 571 if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable) { 572 jit->r14_thunk_ip = jit->prg; 573 /* Generate __s390_indirect_jump_r14 thunk */ 574 if (test_facility(35)) { 575 /* exrl %r0,.+10 */ 576 EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10); 577 } else { 578 /* larl %r1,.+14 */ 579 EMIT6_PCREL_RILB(0xc0000000, REG_1, jit->prg + 14); 580 /* ex 0,0(%r1) */ 581 EMIT4_DISP(0x44000000, REG_0, REG_1, 0); 582 } 583 /* j . */ 584 EMIT4_PCREL(0xa7f40000, 0); 585 } 586 /* br %r14 */ 587 _EMIT2(0x07fe); 588 589 if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable && 590 (is_first_pass(jit) || (jit->seen & SEEN_FUNC))) { 591 jit->r1_thunk_ip = jit->prg; 592 /* Generate __s390_indirect_jump_r1 thunk */ 593 if (test_facility(35)) { 594 /* exrl %r0,.+10 */ 595 EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10); 596 /* j . */ 597 EMIT4_PCREL(0xa7f40000, 0); 598 /* br %r1 */ 599 _EMIT2(0x07f1); 600 } else { 601 /* ex 0,S390_lowcore.br_r1_tampoline */ 602 EMIT4_DISP(0x44000000, REG_0, REG_0, 603 offsetof(struct lowcore, br_r1_trampoline)); 604 /* j . */ 605 EMIT4_PCREL(0xa7f40000, 0); 606 } 607 } 608 } 609 610 static int get_probe_mem_regno(const u8 *insn) 611 { 612 /* 613 * insn must point to llgc, llgh, llgf or lg, which have destination 614 * register at the same position. 615 */ 616 if (insn[0] != 0xe3) /* common llgc, llgh, llgf and lg prefix */ 617 return -1; 618 if (insn[5] != 0x90 && /* llgc */ 619 insn[5] != 0x91 && /* llgh */ 620 insn[5] != 0x16 && /* llgf */ 621 insn[5] != 0x04) /* lg */ 622 return -1; 623 return insn[1] >> 4; 624 } 625 626 static bool ex_handler_bpf(const struct exception_table_entry *x, 627 struct pt_regs *regs) 628 { 629 int regno; 630 u8 *insn; 631 632 regs->psw.addr = extable_fixup(x); 633 insn = (u8 *)__rewind_psw(regs->psw, regs->int_code >> 16); 634 regno = get_probe_mem_regno(insn); 635 if (WARN_ON_ONCE(regno < 0)) 636 /* JIT bug - unexpected instruction. */ 637 return false; 638 regs->gprs[regno] = 0; 639 return true; 640 } 641 642 static int bpf_jit_probe_mem(struct bpf_jit *jit, struct bpf_prog *fp, 643 int probe_prg, int nop_prg) 644 { 645 struct exception_table_entry *ex; 646 s64 delta; 647 u8 *insn; 648 int prg; 649 int i; 650 651 if (!fp->aux->extable) 652 /* Do nothing during early JIT passes. */ 653 return 0; 654 insn = jit->prg_buf + probe_prg; 655 if (WARN_ON_ONCE(get_probe_mem_regno(insn) < 0)) 656 /* JIT bug - unexpected probe instruction. */ 657 return -1; 658 if (WARN_ON_ONCE(probe_prg + insn_length(*insn) != nop_prg)) 659 /* JIT bug - gap between probe and nop instructions. */ 660 return -1; 661 for (i = 0; i < 2; i++) { 662 if (WARN_ON_ONCE(jit->excnt >= fp->aux->num_exentries)) 663 /* Verifier bug - not enough entries. */ 664 return -1; 665 ex = &fp->aux->extable[jit->excnt]; 666 /* Add extable entries for probe and nop instructions. */ 667 prg = i == 0 ? probe_prg : nop_prg; 668 delta = jit->prg_buf + prg - (u8 *)&ex->insn; 669 if (WARN_ON_ONCE(delta < INT_MIN || delta > INT_MAX)) 670 /* JIT bug - code and extable must be close. */ 671 return -1; 672 ex->insn = delta; 673 /* 674 * Always land on the nop. Note that extable infrastructure 675 * ignores fixup field, it is handled by ex_handler_bpf(). 676 */ 677 delta = jit->prg_buf + nop_prg - (u8 *)&ex->fixup; 678 if (WARN_ON_ONCE(delta < INT_MIN || delta > INT_MAX)) 679 /* JIT bug - landing pad and extable must be close. */ 680 return -1; 681 ex->fixup = delta; 682 ex->handler = (u8 *)ex_handler_bpf - (u8 *)&ex->handler; 683 jit->excnt++; 684 } 685 return 0; 686 } 687 688 /* 689 * Compile one eBPF instruction into s390x code 690 * 691 * NOTE: Use noinline because for gcov (-fprofile-arcs) gcc allocates a lot of 692 * stack space for the large switch statement. 693 */ 694 static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, 695 int i, bool extra_pass, u32 stack_depth) 696 { 697 struct bpf_insn *insn = &fp->insnsi[i]; 698 u32 dst_reg = insn->dst_reg; 699 u32 src_reg = insn->src_reg; 700 int last, insn_count = 1; 701 u32 *addrs = jit->addrs; 702 s32 imm = insn->imm; 703 s16 off = insn->off; 704 int probe_prg = -1; 705 unsigned int mask; 706 int nop_prg; 707 int err; 708 709 if (BPF_CLASS(insn->code) == BPF_LDX && 710 BPF_MODE(insn->code) == BPF_PROBE_MEM) 711 probe_prg = jit->prg; 712 713 switch (insn->code) { 714 /* 715 * BPF_MOV 716 */ 717 case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */ 718 /* llgfr %dst,%src */ 719 EMIT4(0xb9160000, dst_reg, src_reg); 720 if (insn_is_zext(&insn[1])) 721 insn_count = 2; 722 break; 723 case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */ 724 /* lgr %dst,%src */ 725 EMIT4(0xb9040000, dst_reg, src_reg); 726 break; 727 case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */ 728 /* llilf %dst,imm */ 729 EMIT6_IMM(0xc00f0000, dst_reg, imm); 730 if (insn_is_zext(&insn[1])) 731 insn_count = 2; 732 break; 733 case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */ 734 /* lgfi %dst,imm */ 735 EMIT6_IMM(0xc0010000, dst_reg, imm); 736 break; 737 /* 738 * BPF_LD 64 739 */ 740 case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */ 741 { 742 /* 16 byte instruction that uses two 'struct bpf_insn' */ 743 u64 imm64; 744 745 imm64 = (u64)(u32) insn[0].imm | ((u64)(u32) insn[1].imm) << 32; 746 /* lgrl %dst,imm */ 747 EMIT6_PCREL_RILB(0xc4080000, dst_reg, _EMIT_CONST_U64(imm64)); 748 insn_count = 2; 749 break; 750 } 751 /* 752 * BPF_ADD 753 */ 754 case BPF_ALU | BPF_ADD | BPF_X: /* dst = (u32) dst + (u32) src */ 755 /* ar %dst,%src */ 756 EMIT2(0x1a00, dst_reg, src_reg); 757 EMIT_ZERO(dst_reg); 758 break; 759 case BPF_ALU64 | BPF_ADD | BPF_X: /* dst = dst + src */ 760 /* agr %dst,%src */ 761 EMIT4(0xb9080000, dst_reg, src_reg); 762 break; 763 case BPF_ALU | BPF_ADD | BPF_K: /* dst = (u32) dst + (u32) imm */ 764 if (!imm) 765 break; 766 /* alfi %dst,imm */ 767 EMIT6_IMM(0xc20b0000, dst_reg, imm); 768 EMIT_ZERO(dst_reg); 769 break; 770 case BPF_ALU64 | BPF_ADD | BPF_K: /* dst = dst + imm */ 771 if (!imm) 772 break; 773 /* agfi %dst,imm */ 774 EMIT6_IMM(0xc2080000, dst_reg, imm); 775 break; 776 /* 777 * BPF_SUB 778 */ 779 case BPF_ALU | BPF_SUB | BPF_X: /* dst = (u32) dst - (u32) src */ 780 /* sr %dst,%src */ 781 EMIT2(0x1b00, dst_reg, src_reg); 782 EMIT_ZERO(dst_reg); 783 break; 784 case BPF_ALU64 | BPF_SUB | BPF_X: /* dst = dst - src */ 785 /* sgr %dst,%src */ 786 EMIT4(0xb9090000, dst_reg, src_reg); 787 break; 788 case BPF_ALU | BPF_SUB | BPF_K: /* dst = (u32) dst - (u32) imm */ 789 if (!imm) 790 break; 791 /* alfi %dst,-imm */ 792 EMIT6_IMM(0xc20b0000, dst_reg, -imm); 793 EMIT_ZERO(dst_reg); 794 break; 795 case BPF_ALU64 | BPF_SUB | BPF_K: /* dst = dst - imm */ 796 if (!imm) 797 break; 798 /* agfi %dst,-imm */ 799 EMIT6_IMM(0xc2080000, dst_reg, -imm); 800 break; 801 /* 802 * BPF_MUL 803 */ 804 case BPF_ALU | BPF_MUL | BPF_X: /* dst = (u32) dst * (u32) src */ 805 /* msr %dst,%src */ 806 EMIT4(0xb2520000, dst_reg, src_reg); 807 EMIT_ZERO(dst_reg); 808 break; 809 case BPF_ALU64 | BPF_MUL | BPF_X: /* dst = dst * src */ 810 /* msgr %dst,%src */ 811 EMIT4(0xb90c0000, dst_reg, src_reg); 812 break; 813 case BPF_ALU | BPF_MUL | BPF_K: /* dst = (u32) dst * (u32) imm */ 814 if (imm == 1) 815 break; 816 /* msfi %r5,imm */ 817 EMIT6_IMM(0xc2010000, dst_reg, imm); 818 EMIT_ZERO(dst_reg); 819 break; 820 case BPF_ALU64 | BPF_MUL | BPF_K: /* dst = dst * imm */ 821 if (imm == 1) 822 break; 823 /* msgfi %dst,imm */ 824 EMIT6_IMM(0xc2000000, dst_reg, imm); 825 break; 826 /* 827 * BPF_DIV / BPF_MOD 828 */ 829 case BPF_ALU | BPF_DIV | BPF_X: /* dst = (u32) dst / (u32) src */ 830 case BPF_ALU | BPF_MOD | BPF_X: /* dst = (u32) dst % (u32) src */ 831 { 832 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0; 833 834 /* lhi %w0,0 */ 835 EMIT4_IMM(0xa7080000, REG_W0, 0); 836 /* lr %w1,%dst */ 837 EMIT2(0x1800, REG_W1, dst_reg); 838 /* dlr %w0,%src */ 839 EMIT4(0xb9970000, REG_W0, src_reg); 840 /* llgfr %dst,%rc */ 841 EMIT4(0xb9160000, dst_reg, rc_reg); 842 if (insn_is_zext(&insn[1])) 843 insn_count = 2; 844 break; 845 } 846 case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */ 847 case BPF_ALU64 | BPF_MOD | BPF_X: /* dst = dst % src */ 848 { 849 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0; 850 851 /* lghi %w0,0 */ 852 EMIT4_IMM(0xa7090000, REG_W0, 0); 853 /* lgr %w1,%dst */ 854 EMIT4(0xb9040000, REG_W1, dst_reg); 855 /* dlgr %w0,%dst */ 856 EMIT4(0xb9870000, REG_W0, src_reg); 857 /* lgr %dst,%rc */ 858 EMIT4(0xb9040000, dst_reg, rc_reg); 859 break; 860 } 861 case BPF_ALU | BPF_DIV | BPF_K: /* dst = (u32) dst / (u32) imm */ 862 case BPF_ALU | BPF_MOD | BPF_K: /* dst = (u32) dst % (u32) imm */ 863 { 864 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0; 865 866 if (imm == 1) { 867 if (BPF_OP(insn->code) == BPF_MOD) 868 /* lhgi %dst,0 */ 869 EMIT4_IMM(0xa7090000, dst_reg, 0); 870 break; 871 } 872 /* lhi %w0,0 */ 873 EMIT4_IMM(0xa7080000, REG_W0, 0); 874 /* lr %w1,%dst */ 875 EMIT2(0x1800, REG_W1, dst_reg); 876 if (!is_first_pass(jit) && can_use_ldisp_for_lit32(jit)) { 877 /* dl %w0,<d(imm)>(%l) */ 878 EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0, REG_L, 879 EMIT_CONST_U32(imm)); 880 } else { 881 /* lgfrl %dst,imm */ 882 EMIT6_PCREL_RILB(0xc40c0000, dst_reg, 883 _EMIT_CONST_U32(imm)); 884 jit->seen |= SEEN_LITERAL; 885 /* dlr %w0,%dst */ 886 EMIT4(0xb9970000, REG_W0, dst_reg); 887 } 888 /* llgfr %dst,%rc */ 889 EMIT4(0xb9160000, dst_reg, rc_reg); 890 if (insn_is_zext(&insn[1])) 891 insn_count = 2; 892 break; 893 } 894 case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */ 895 case BPF_ALU64 | BPF_MOD | BPF_K: /* dst = dst % imm */ 896 { 897 int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0; 898 899 if (imm == 1) { 900 if (BPF_OP(insn->code) == BPF_MOD) 901 /* lhgi %dst,0 */ 902 EMIT4_IMM(0xa7090000, dst_reg, 0); 903 break; 904 } 905 /* lghi %w0,0 */ 906 EMIT4_IMM(0xa7090000, REG_W0, 0); 907 /* lgr %w1,%dst */ 908 EMIT4(0xb9040000, REG_W1, dst_reg); 909 if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) { 910 /* dlg %w0,<d(imm)>(%l) */ 911 EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0, REG_L, 912 EMIT_CONST_U64(imm)); 913 } else { 914 /* lgrl %dst,imm */ 915 EMIT6_PCREL_RILB(0xc4080000, dst_reg, 916 _EMIT_CONST_U64(imm)); 917 jit->seen |= SEEN_LITERAL; 918 /* dlgr %w0,%dst */ 919 EMIT4(0xb9870000, REG_W0, dst_reg); 920 } 921 /* lgr %dst,%rc */ 922 EMIT4(0xb9040000, dst_reg, rc_reg); 923 break; 924 } 925 /* 926 * BPF_AND 927 */ 928 case BPF_ALU | BPF_AND | BPF_X: /* dst = (u32) dst & (u32) src */ 929 /* nr %dst,%src */ 930 EMIT2(0x1400, dst_reg, src_reg); 931 EMIT_ZERO(dst_reg); 932 break; 933 case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */ 934 /* ngr %dst,%src */ 935 EMIT4(0xb9800000, dst_reg, src_reg); 936 break; 937 case BPF_ALU | BPF_AND | BPF_K: /* dst = (u32) dst & (u32) imm */ 938 /* nilf %dst,imm */ 939 EMIT6_IMM(0xc00b0000, dst_reg, imm); 940 EMIT_ZERO(dst_reg); 941 break; 942 case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */ 943 if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) { 944 /* ng %dst,<d(imm)>(%l) */ 945 EMIT6_DISP_LH(0xe3000000, 0x0080, 946 dst_reg, REG_0, REG_L, 947 EMIT_CONST_U64(imm)); 948 } else { 949 /* lgrl %w0,imm */ 950 EMIT6_PCREL_RILB(0xc4080000, REG_W0, 951 _EMIT_CONST_U64(imm)); 952 jit->seen |= SEEN_LITERAL; 953 /* ngr %dst,%w0 */ 954 EMIT4(0xb9800000, dst_reg, REG_W0); 955 } 956 break; 957 /* 958 * BPF_OR 959 */ 960 case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */ 961 /* or %dst,%src */ 962 EMIT2(0x1600, dst_reg, src_reg); 963 EMIT_ZERO(dst_reg); 964 break; 965 case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */ 966 /* ogr %dst,%src */ 967 EMIT4(0xb9810000, dst_reg, src_reg); 968 break; 969 case BPF_ALU | BPF_OR | BPF_K: /* dst = (u32) dst | (u32) imm */ 970 /* oilf %dst,imm */ 971 EMIT6_IMM(0xc00d0000, dst_reg, imm); 972 EMIT_ZERO(dst_reg); 973 break; 974 case BPF_ALU64 | BPF_OR | BPF_K: /* dst = dst | imm */ 975 if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) { 976 /* og %dst,<d(imm)>(%l) */ 977 EMIT6_DISP_LH(0xe3000000, 0x0081, 978 dst_reg, REG_0, REG_L, 979 EMIT_CONST_U64(imm)); 980 } else { 981 /* lgrl %w0,imm */ 982 EMIT6_PCREL_RILB(0xc4080000, REG_W0, 983 _EMIT_CONST_U64(imm)); 984 jit->seen |= SEEN_LITERAL; 985 /* ogr %dst,%w0 */ 986 EMIT4(0xb9810000, dst_reg, REG_W0); 987 } 988 break; 989 /* 990 * BPF_XOR 991 */ 992 case BPF_ALU | BPF_XOR | BPF_X: /* dst = (u32) dst ^ (u32) src */ 993 /* xr %dst,%src */ 994 EMIT2(0x1700, dst_reg, src_reg); 995 EMIT_ZERO(dst_reg); 996 break; 997 case BPF_ALU64 | BPF_XOR | BPF_X: /* dst = dst ^ src */ 998 /* xgr %dst,%src */ 999 EMIT4(0xb9820000, dst_reg, src_reg); 1000 break; 1001 case BPF_ALU | BPF_XOR | BPF_K: /* dst = (u32) dst ^ (u32) imm */ 1002 if (!imm) 1003 break; 1004 /* xilf %dst,imm */ 1005 EMIT6_IMM(0xc0070000, dst_reg, imm); 1006 EMIT_ZERO(dst_reg); 1007 break; 1008 case BPF_ALU64 | BPF_XOR | BPF_K: /* dst = dst ^ imm */ 1009 if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) { 1010 /* xg %dst,<d(imm)>(%l) */ 1011 EMIT6_DISP_LH(0xe3000000, 0x0082, 1012 dst_reg, REG_0, REG_L, 1013 EMIT_CONST_U64(imm)); 1014 } else { 1015 /* lgrl %w0,imm */ 1016 EMIT6_PCREL_RILB(0xc4080000, REG_W0, 1017 _EMIT_CONST_U64(imm)); 1018 jit->seen |= SEEN_LITERAL; 1019 /* xgr %dst,%w0 */ 1020 EMIT4(0xb9820000, dst_reg, REG_W0); 1021 } 1022 break; 1023 /* 1024 * BPF_LSH 1025 */ 1026 case BPF_ALU | BPF_LSH | BPF_X: /* dst = (u32) dst << (u32) src */ 1027 /* sll %dst,0(%src) */ 1028 EMIT4_DISP(0x89000000, dst_reg, src_reg, 0); 1029 EMIT_ZERO(dst_reg); 1030 break; 1031 case BPF_ALU64 | BPF_LSH | BPF_X: /* dst = dst << src */ 1032 /* sllg %dst,%dst,0(%src) */ 1033 EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, src_reg, 0); 1034 break; 1035 case BPF_ALU | BPF_LSH | BPF_K: /* dst = (u32) dst << (u32) imm */ 1036 if (imm == 0) 1037 break; 1038 /* sll %dst,imm(%r0) */ 1039 EMIT4_DISP(0x89000000, dst_reg, REG_0, imm); 1040 EMIT_ZERO(dst_reg); 1041 break; 1042 case BPF_ALU64 | BPF_LSH | BPF_K: /* dst = dst << imm */ 1043 if (imm == 0) 1044 break; 1045 /* sllg %dst,%dst,imm(%r0) */ 1046 EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, REG_0, imm); 1047 break; 1048 /* 1049 * BPF_RSH 1050 */ 1051 case BPF_ALU | BPF_RSH | BPF_X: /* dst = (u32) dst >> (u32) src */ 1052 /* srl %dst,0(%src) */ 1053 EMIT4_DISP(0x88000000, dst_reg, src_reg, 0); 1054 EMIT_ZERO(dst_reg); 1055 break; 1056 case BPF_ALU64 | BPF_RSH | BPF_X: /* dst = dst >> src */ 1057 /* srlg %dst,%dst,0(%src) */ 1058 EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, src_reg, 0); 1059 break; 1060 case BPF_ALU | BPF_RSH | BPF_K: /* dst = (u32) dst >> (u32) imm */ 1061 if (imm == 0) 1062 break; 1063 /* srl %dst,imm(%r0) */ 1064 EMIT4_DISP(0x88000000, dst_reg, REG_0, imm); 1065 EMIT_ZERO(dst_reg); 1066 break; 1067 case BPF_ALU64 | BPF_RSH | BPF_K: /* dst = dst >> imm */ 1068 if (imm == 0) 1069 break; 1070 /* srlg %dst,%dst,imm(%r0) */ 1071 EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, REG_0, imm); 1072 break; 1073 /* 1074 * BPF_ARSH 1075 */ 1076 case BPF_ALU | BPF_ARSH | BPF_X: /* ((s32) dst) >>= src */ 1077 /* sra %dst,%dst,0(%src) */ 1078 EMIT4_DISP(0x8a000000, dst_reg, src_reg, 0); 1079 EMIT_ZERO(dst_reg); 1080 break; 1081 case BPF_ALU64 | BPF_ARSH | BPF_X: /* ((s64) dst) >>= src */ 1082 /* srag %dst,%dst,0(%src) */ 1083 EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, src_reg, 0); 1084 break; 1085 case BPF_ALU | BPF_ARSH | BPF_K: /* ((s32) dst >> imm */ 1086 if (imm == 0) 1087 break; 1088 /* sra %dst,imm(%r0) */ 1089 EMIT4_DISP(0x8a000000, dst_reg, REG_0, imm); 1090 EMIT_ZERO(dst_reg); 1091 break; 1092 case BPF_ALU64 | BPF_ARSH | BPF_K: /* ((s64) dst) >>= imm */ 1093 if (imm == 0) 1094 break; 1095 /* srag %dst,%dst,imm(%r0) */ 1096 EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, REG_0, imm); 1097 break; 1098 /* 1099 * BPF_NEG 1100 */ 1101 case BPF_ALU | BPF_NEG: /* dst = (u32) -dst */ 1102 /* lcr %dst,%dst */ 1103 EMIT2(0x1300, dst_reg, dst_reg); 1104 EMIT_ZERO(dst_reg); 1105 break; 1106 case BPF_ALU64 | BPF_NEG: /* dst = -dst */ 1107 /* lcgr %dst,%dst */ 1108 EMIT4(0xb9030000, dst_reg, dst_reg); 1109 break; 1110 /* 1111 * BPF_FROM_BE/LE 1112 */ 1113 case BPF_ALU | BPF_END | BPF_FROM_BE: 1114 /* s390 is big endian, therefore only clear high order bytes */ 1115 switch (imm) { 1116 case 16: /* dst = (u16) cpu_to_be16(dst) */ 1117 /* llghr %dst,%dst */ 1118 EMIT4(0xb9850000, dst_reg, dst_reg); 1119 if (insn_is_zext(&insn[1])) 1120 insn_count = 2; 1121 break; 1122 case 32: /* dst = (u32) cpu_to_be32(dst) */ 1123 if (!fp->aux->verifier_zext) 1124 /* llgfr %dst,%dst */ 1125 EMIT4(0xb9160000, dst_reg, dst_reg); 1126 break; 1127 case 64: /* dst = (u64) cpu_to_be64(dst) */ 1128 break; 1129 } 1130 break; 1131 case BPF_ALU | BPF_END | BPF_FROM_LE: 1132 switch (imm) { 1133 case 16: /* dst = (u16) cpu_to_le16(dst) */ 1134 /* lrvr %dst,%dst */ 1135 EMIT4(0xb91f0000, dst_reg, dst_reg); 1136 /* srl %dst,16(%r0) */ 1137 EMIT4_DISP(0x88000000, dst_reg, REG_0, 16); 1138 /* llghr %dst,%dst */ 1139 EMIT4(0xb9850000, dst_reg, dst_reg); 1140 if (insn_is_zext(&insn[1])) 1141 insn_count = 2; 1142 break; 1143 case 32: /* dst = (u32) cpu_to_le32(dst) */ 1144 /* lrvr %dst,%dst */ 1145 EMIT4(0xb91f0000, dst_reg, dst_reg); 1146 if (!fp->aux->verifier_zext) 1147 /* llgfr %dst,%dst */ 1148 EMIT4(0xb9160000, dst_reg, dst_reg); 1149 break; 1150 case 64: /* dst = (u64) cpu_to_le64(dst) */ 1151 /* lrvgr %dst,%dst */ 1152 EMIT4(0xb90f0000, dst_reg, dst_reg); 1153 break; 1154 } 1155 break; 1156 /* 1157 * BPF_ST(X) 1158 */ 1159 case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src_reg */ 1160 /* stcy %src,off(%dst) */ 1161 EMIT6_DISP_LH(0xe3000000, 0x0072, src_reg, dst_reg, REG_0, off); 1162 jit->seen |= SEEN_MEM; 1163 break; 1164 case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */ 1165 /* sthy %src,off(%dst) */ 1166 EMIT6_DISP_LH(0xe3000000, 0x0070, src_reg, dst_reg, REG_0, off); 1167 jit->seen |= SEEN_MEM; 1168 break; 1169 case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */ 1170 /* sty %src,off(%dst) */ 1171 EMIT6_DISP_LH(0xe3000000, 0x0050, src_reg, dst_reg, REG_0, off); 1172 jit->seen |= SEEN_MEM; 1173 break; 1174 case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */ 1175 /* stg %src,off(%dst) */ 1176 EMIT6_DISP_LH(0xe3000000, 0x0024, src_reg, dst_reg, REG_0, off); 1177 jit->seen |= SEEN_MEM; 1178 break; 1179 case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */ 1180 /* lhi %w0,imm */ 1181 EMIT4_IMM(0xa7080000, REG_W0, (u8) imm); 1182 /* stcy %w0,off(dst) */ 1183 EMIT6_DISP_LH(0xe3000000, 0x0072, REG_W0, dst_reg, REG_0, off); 1184 jit->seen |= SEEN_MEM; 1185 break; 1186 case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */ 1187 /* lhi %w0,imm */ 1188 EMIT4_IMM(0xa7080000, REG_W0, (u16) imm); 1189 /* sthy %w0,off(dst) */ 1190 EMIT6_DISP_LH(0xe3000000, 0x0070, REG_W0, dst_reg, REG_0, off); 1191 jit->seen |= SEEN_MEM; 1192 break; 1193 case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */ 1194 /* llilf %w0,imm */ 1195 EMIT6_IMM(0xc00f0000, REG_W0, (u32) imm); 1196 /* sty %w0,off(%dst) */ 1197 EMIT6_DISP_LH(0xe3000000, 0x0050, REG_W0, dst_reg, REG_0, off); 1198 jit->seen |= SEEN_MEM; 1199 break; 1200 case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */ 1201 /* lgfi %w0,imm */ 1202 EMIT6_IMM(0xc0010000, REG_W0, imm); 1203 /* stg %w0,off(%dst) */ 1204 EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W0, dst_reg, REG_0, off); 1205 jit->seen |= SEEN_MEM; 1206 break; 1207 /* 1208 * BPF_STX XADD (atomic_add) 1209 */ 1210 case BPF_STX | BPF_XADD | BPF_W: /* *(u32 *)(dst + off) += src */ 1211 /* laal %w0,%src,off(%dst) */ 1212 EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W0, src_reg, 1213 dst_reg, off); 1214 jit->seen |= SEEN_MEM; 1215 break; 1216 case BPF_STX | BPF_XADD | BPF_DW: /* *(u64 *)(dst + off) += src */ 1217 /* laalg %w0,%src,off(%dst) */ 1218 EMIT6_DISP_LH(0xeb000000, 0x00ea, REG_W0, src_reg, 1219 dst_reg, off); 1220 jit->seen |= SEEN_MEM; 1221 break; 1222 /* 1223 * BPF_LDX 1224 */ 1225 case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */ 1226 case BPF_LDX | BPF_PROBE_MEM | BPF_B: 1227 /* llgc %dst,0(off,%src) */ 1228 EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off); 1229 jit->seen |= SEEN_MEM; 1230 if (insn_is_zext(&insn[1])) 1231 insn_count = 2; 1232 break; 1233 case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */ 1234 case BPF_LDX | BPF_PROBE_MEM | BPF_H: 1235 /* llgh %dst,0(off,%src) */ 1236 EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off); 1237 jit->seen |= SEEN_MEM; 1238 if (insn_is_zext(&insn[1])) 1239 insn_count = 2; 1240 break; 1241 case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */ 1242 case BPF_LDX | BPF_PROBE_MEM | BPF_W: 1243 /* llgf %dst,off(%src) */ 1244 jit->seen |= SEEN_MEM; 1245 EMIT6_DISP_LH(0xe3000000, 0x0016, dst_reg, src_reg, REG_0, off); 1246 if (insn_is_zext(&insn[1])) 1247 insn_count = 2; 1248 break; 1249 case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */ 1250 case BPF_LDX | BPF_PROBE_MEM | BPF_DW: 1251 /* lg %dst,0(off,%src) */ 1252 jit->seen |= SEEN_MEM; 1253 EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, src_reg, REG_0, off); 1254 break; 1255 /* 1256 * BPF_JMP / CALL 1257 */ 1258 case BPF_JMP | BPF_CALL: 1259 { 1260 u64 func; 1261 bool func_addr_fixed; 1262 int ret; 1263 1264 ret = bpf_jit_get_func_addr(fp, insn, extra_pass, 1265 &func, &func_addr_fixed); 1266 if (ret < 0) 1267 return -1; 1268 1269 REG_SET_SEEN(BPF_REG_5); 1270 jit->seen |= SEEN_FUNC; 1271 /* lgrl %w1,func */ 1272 EMIT6_PCREL_RILB(0xc4080000, REG_W1, _EMIT_CONST_U64(func)); 1273 if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable) { 1274 /* brasl %r14,__s390_indirect_jump_r1 */ 1275 EMIT6_PCREL_RILB(0xc0050000, REG_14, jit->r1_thunk_ip); 1276 } else { 1277 /* basr %r14,%w1 */ 1278 EMIT2(0x0d00, REG_14, REG_W1); 1279 } 1280 /* lgr %b0,%r2: load return value into %b0 */ 1281 EMIT4(0xb9040000, BPF_REG_0, REG_2); 1282 break; 1283 } 1284 case BPF_JMP | BPF_TAIL_CALL: { 1285 int patch_1_clrj, patch_2_clij, patch_3_brc; 1286 1287 /* 1288 * Implicit input: 1289 * B1: pointer to ctx 1290 * B2: pointer to bpf_array 1291 * B3: index in bpf_array 1292 */ 1293 jit->seen |= SEEN_TAIL_CALL; 1294 1295 /* 1296 * if (index >= array->map.max_entries) 1297 * goto out; 1298 */ 1299 1300 /* llgf %w1,map.max_entries(%b2) */ 1301 EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_2, 1302 offsetof(struct bpf_array, map.max_entries)); 1303 /* if ((u32)%b3 >= (u32)%w1) goto out; */ 1304 /* clrj %b3,%w1,0xa,out */ 1305 patch_1_clrj = jit->prg; 1306 EMIT6_PCREL_RIEB(0xec000000, 0x0077, BPF_REG_3, REG_W1, 0xa, 1307 jit->prg); 1308 1309 /* 1310 * if (tail_call_cnt++ > MAX_TAIL_CALL_CNT) 1311 * goto out; 1312 */ 1313 1314 if (jit->seen & SEEN_STACK) 1315 off = STK_OFF_TCCNT + STK_OFF + stack_depth; 1316 else 1317 off = STK_OFF_TCCNT; 1318 /* lhi %w0,1 */ 1319 EMIT4_IMM(0xa7080000, REG_W0, 1); 1320 /* laal %w1,%w0,off(%r15) */ 1321 EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, REG_15, off); 1322 /* clij %w1,MAX_TAIL_CALL_CNT,0x2,out */ 1323 patch_2_clij = jit->prg; 1324 EMIT6_PCREL_RIEC(0xec000000, 0x007f, REG_W1, MAX_TAIL_CALL_CNT, 1325 2, jit->prg); 1326 1327 /* 1328 * prog = array->ptrs[index]; 1329 * if (prog == NULL) 1330 * goto out; 1331 */ 1332 1333 /* llgfr %r1,%b3: %r1 = (u32) index */ 1334 EMIT4(0xb9160000, REG_1, BPF_REG_3); 1335 /* sllg %r1,%r1,3: %r1 *= 8 */ 1336 EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, REG_1, REG_0, 3); 1337 /* ltg %r1,prog(%b2,%r1) */ 1338 EMIT6_DISP_LH(0xe3000000, 0x0002, REG_1, BPF_REG_2, 1339 REG_1, offsetof(struct bpf_array, ptrs)); 1340 /* brc 0x8,out */ 1341 patch_3_brc = jit->prg; 1342 EMIT4_PCREL_RIC(0xa7040000, 8, jit->prg); 1343 1344 /* 1345 * Restore registers before calling function 1346 */ 1347 save_restore_regs(jit, REGS_RESTORE, stack_depth); 1348 1349 /* 1350 * goto *(prog->bpf_func + tail_call_start); 1351 */ 1352 1353 /* lg %r1,bpf_func(%r1) */ 1354 EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, REG_1, REG_0, 1355 offsetof(struct bpf_prog, bpf_func)); 1356 /* bc 0xf,tail_call_start(%r1) */ 1357 _EMIT4(0x47f01000 + jit->tail_call_start); 1358 /* out: */ 1359 if (jit->prg_buf) { 1360 *(u16 *)(jit->prg_buf + patch_1_clrj + 2) = 1361 (jit->prg - patch_1_clrj) >> 1; 1362 *(u16 *)(jit->prg_buf + patch_2_clij + 2) = 1363 (jit->prg - patch_2_clij) >> 1; 1364 *(u16 *)(jit->prg_buf + patch_3_brc + 2) = 1365 (jit->prg - patch_3_brc) >> 1; 1366 } 1367 break; 1368 } 1369 case BPF_JMP | BPF_EXIT: /* return b0 */ 1370 last = (i == fp->len - 1) ? 1 : 0; 1371 if (last) 1372 break; 1373 if (!is_first_pass(jit) && can_use_rel(jit, jit->exit_ip)) 1374 /* brc 0xf, <exit> */ 1375 EMIT4_PCREL_RIC(0xa7040000, 0xf, jit->exit_ip); 1376 else 1377 /* brcl 0xf, <exit> */ 1378 EMIT6_PCREL_RILC(0xc0040000, 0xf, jit->exit_ip); 1379 break; 1380 /* 1381 * Branch relative (number of skipped instructions) to offset on 1382 * condition. 1383 * 1384 * Condition code to mask mapping: 1385 * 1386 * CC | Description | Mask 1387 * ------------------------------ 1388 * 0 | Operands equal | 8 1389 * 1 | First operand low | 4 1390 * 2 | First operand high | 2 1391 * 3 | Unused | 1 1392 * 1393 * For s390x relative branches: ip = ip + off_bytes 1394 * For BPF relative branches: insn = insn + off_insns + 1 1395 * 1396 * For example for s390x with offset 0 we jump to the branch 1397 * instruction itself (loop) and for BPF with offset 0 we 1398 * branch to the instruction behind the branch. 1399 */ 1400 case BPF_JMP | BPF_JA: /* if (true) */ 1401 mask = 0xf000; /* j */ 1402 goto branch_oc; 1403 case BPF_JMP | BPF_JSGT | BPF_K: /* ((s64) dst > (s64) imm) */ 1404 case BPF_JMP32 | BPF_JSGT | BPF_K: /* ((s32) dst > (s32) imm) */ 1405 mask = 0x2000; /* jh */ 1406 goto branch_ks; 1407 case BPF_JMP | BPF_JSLT | BPF_K: /* ((s64) dst < (s64) imm) */ 1408 case BPF_JMP32 | BPF_JSLT | BPF_K: /* ((s32) dst < (s32) imm) */ 1409 mask = 0x4000; /* jl */ 1410 goto branch_ks; 1411 case BPF_JMP | BPF_JSGE | BPF_K: /* ((s64) dst >= (s64) imm) */ 1412 case BPF_JMP32 | BPF_JSGE | BPF_K: /* ((s32) dst >= (s32) imm) */ 1413 mask = 0xa000; /* jhe */ 1414 goto branch_ks; 1415 case BPF_JMP | BPF_JSLE | BPF_K: /* ((s64) dst <= (s64) imm) */ 1416 case BPF_JMP32 | BPF_JSLE | BPF_K: /* ((s32) dst <= (s32) imm) */ 1417 mask = 0xc000; /* jle */ 1418 goto branch_ks; 1419 case BPF_JMP | BPF_JGT | BPF_K: /* (dst_reg > imm) */ 1420 case BPF_JMP32 | BPF_JGT | BPF_K: /* ((u32) dst_reg > (u32) imm) */ 1421 mask = 0x2000; /* jh */ 1422 goto branch_ku; 1423 case BPF_JMP | BPF_JLT | BPF_K: /* (dst_reg < imm) */ 1424 case BPF_JMP32 | BPF_JLT | BPF_K: /* ((u32) dst_reg < (u32) imm) */ 1425 mask = 0x4000; /* jl */ 1426 goto branch_ku; 1427 case BPF_JMP | BPF_JGE | BPF_K: /* (dst_reg >= imm) */ 1428 case BPF_JMP32 | BPF_JGE | BPF_K: /* ((u32) dst_reg >= (u32) imm) */ 1429 mask = 0xa000; /* jhe */ 1430 goto branch_ku; 1431 case BPF_JMP | BPF_JLE | BPF_K: /* (dst_reg <= imm) */ 1432 case BPF_JMP32 | BPF_JLE | BPF_K: /* ((u32) dst_reg <= (u32) imm) */ 1433 mask = 0xc000; /* jle */ 1434 goto branch_ku; 1435 case BPF_JMP | BPF_JNE | BPF_K: /* (dst_reg != imm) */ 1436 case BPF_JMP32 | BPF_JNE | BPF_K: /* ((u32) dst_reg != (u32) imm) */ 1437 mask = 0x7000; /* jne */ 1438 goto branch_ku; 1439 case BPF_JMP | BPF_JEQ | BPF_K: /* (dst_reg == imm) */ 1440 case BPF_JMP32 | BPF_JEQ | BPF_K: /* ((u32) dst_reg == (u32) imm) */ 1441 mask = 0x8000; /* je */ 1442 goto branch_ku; 1443 case BPF_JMP | BPF_JSET | BPF_K: /* (dst_reg & imm) */ 1444 case BPF_JMP32 | BPF_JSET | BPF_K: /* ((u32) dst_reg & (u32) imm) */ 1445 mask = 0x7000; /* jnz */ 1446 if (BPF_CLASS(insn->code) == BPF_JMP32) { 1447 /* llilf %w1,imm (load zero extend imm) */ 1448 EMIT6_IMM(0xc00f0000, REG_W1, imm); 1449 /* nr %w1,%dst */ 1450 EMIT2(0x1400, REG_W1, dst_reg); 1451 } else { 1452 /* lgfi %w1,imm (load sign extend imm) */ 1453 EMIT6_IMM(0xc0010000, REG_W1, imm); 1454 /* ngr %w1,%dst */ 1455 EMIT4(0xb9800000, REG_W1, dst_reg); 1456 } 1457 goto branch_oc; 1458 1459 case BPF_JMP | BPF_JSGT | BPF_X: /* ((s64) dst > (s64) src) */ 1460 case BPF_JMP32 | BPF_JSGT | BPF_X: /* ((s32) dst > (s32) src) */ 1461 mask = 0x2000; /* jh */ 1462 goto branch_xs; 1463 case BPF_JMP | BPF_JSLT | BPF_X: /* ((s64) dst < (s64) src) */ 1464 case BPF_JMP32 | BPF_JSLT | BPF_X: /* ((s32) dst < (s32) src) */ 1465 mask = 0x4000; /* jl */ 1466 goto branch_xs; 1467 case BPF_JMP | BPF_JSGE | BPF_X: /* ((s64) dst >= (s64) src) */ 1468 case BPF_JMP32 | BPF_JSGE | BPF_X: /* ((s32) dst >= (s32) src) */ 1469 mask = 0xa000; /* jhe */ 1470 goto branch_xs; 1471 case BPF_JMP | BPF_JSLE | BPF_X: /* ((s64) dst <= (s64) src) */ 1472 case BPF_JMP32 | BPF_JSLE | BPF_X: /* ((s32) dst <= (s32) src) */ 1473 mask = 0xc000; /* jle */ 1474 goto branch_xs; 1475 case BPF_JMP | BPF_JGT | BPF_X: /* (dst > src) */ 1476 case BPF_JMP32 | BPF_JGT | BPF_X: /* ((u32) dst > (u32) src) */ 1477 mask = 0x2000; /* jh */ 1478 goto branch_xu; 1479 case BPF_JMP | BPF_JLT | BPF_X: /* (dst < src) */ 1480 case BPF_JMP32 | BPF_JLT | BPF_X: /* ((u32) dst < (u32) src) */ 1481 mask = 0x4000; /* jl */ 1482 goto branch_xu; 1483 case BPF_JMP | BPF_JGE | BPF_X: /* (dst >= src) */ 1484 case BPF_JMP32 | BPF_JGE | BPF_X: /* ((u32) dst >= (u32) src) */ 1485 mask = 0xa000; /* jhe */ 1486 goto branch_xu; 1487 case BPF_JMP | BPF_JLE | BPF_X: /* (dst <= src) */ 1488 case BPF_JMP32 | BPF_JLE | BPF_X: /* ((u32) dst <= (u32) src) */ 1489 mask = 0xc000; /* jle */ 1490 goto branch_xu; 1491 case BPF_JMP | BPF_JNE | BPF_X: /* (dst != src) */ 1492 case BPF_JMP32 | BPF_JNE | BPF_X: /* ((u32) dst != (u32) src) */ 1493 mask = 0x7000; /* jne */ 1494 goto branch_xu; 1495 case BPF_JMP | BPF_JEQ | BPF_X: /* (dst == src) */ 1496 case BPF_JMP32 | BPF_JEQ | BPF_X: /* ((u32) dst == (u32) src) */ 1497 mask = 0x8000; /* je */ 1498 goto branch_xu; 1499 case BPF_JMP | BPF_JSET | BPF_X: /* (dst & src) */ 1500 case BPF_JMP32 | BPF_JSET | BPF_X: /* ((u32) dst & (u32) src) */ 1501 { 1502 bool is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32; 1503 1504 mask = 0x7000; /* jnz */ 1505 /* nrk or ngrk %w1,%dst,%src */ 1506 EMIT4_RRF((is_jmp32 ? 0xb9f40000 : 0xb9e40000), 1507 REG_W1, dst_reg, src_reg); 1508 goto branch_oc; 1509 branch_ks: 1510 is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32; 1511 /* cfi or cgfi %dst,imm */ 1512 EMIT6_IMM(is_jmp32 ? 0xc20d0000 : 0xc20c0000, 1513 dst_reg, imm); 1514 if (!is_first_pass(jit) && 1515 can_use_rel(jit, addrs[i + off + 1])) { 1516 /* brc mask,off */ 1517 EMIT4_PCREL_RIC(0xa7040000, 1518 mask >> 12, addrs[i + off + 1]); 1519 } else { 1520 /* brcl mask,off */ 1521 EMIT6_PCREL_RILC(0xc0040000, 1522 mask >> 12, addrs[i + off + 1]); 1523 } 1524 break; 1525 branch_ku: 1526 /* lgfi %w1,imm (load sign extend imm) */ 1527 src_reg = REG_1; 1528 EMIT6_IMM(0xc0010000, src_reg, imm); 1529 goto branch_xu; 1530 branch_xs: 1531 is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32; 1532 if (!is_first_pass(jit) && 1533 can_use_rel(jit, addrs[i + off + 1])) { 1534 /* crj or cgrj %dst,%src,mask,off */ 1535 EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0076 : 0x0064), 1536 dst_reg, src_reg, i, off, mask); 1537 } else { 1538 /* cr or cgr %dst,%src */ 1539 if (is_jmp32) 1540 EMIT2(0x1900, dst_reg, src_reg); 1541 else 1542 EMIT4(0xb9200000, dst_reg, src_reg); 1543 /* brcl mask,off */ 1544 EMIT6_PCREL_RILC(0xc0040000, 1545 mask >> 12, addrs[i + off + 1]); 1546 } 1547 break; 1548 branch_xu: 1549 is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32; 1550 if (!is_first_pass(jit) && 1551 can_use_rel(jit, addrs[i + off + 1])) { 1552 /* clrj or clgrj %dst,%src,mask,off */ 1553 EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0077 : 0x0065), 1554 dst_reg, src_reg, i, off, mask); 1555 } else { 1556 /* clr or clgr %dst,%src */ 1557 if (is_jmp32) 1558 EMIT2(0x1500, dst_reg, src_reg); 1559 else 1560 EMIT4(0xb9210000, dst_reg, src_reg); 1561 /* brcl mask,off */ 1562 EMIT6_PCREL_RILC(0xc0040000, 1563 mask >> 12, addrs[i + off + 1]); 1564 } 1565 break; 1566 branch_oc: 1567 if (!is_first_pass(jit) && 1568 can_use_rel(jit, addrs[i + off + 1])) { 1569 /* brc mask,off */ 1570 EMIT4_PCREL_RIC(0xa7040000, 1571 mask >> 12, addrs[i + off + 1]); 1572 } else { 1573 /* brcl mask,off */ 1574 EMIT6_PCREL_RILC(0xc0040000, 1575 mask >> 12, addrs[i + off + 1]); 1576 } 1577 break; 1578 } 1579 default: /* too complex, give up */ 1580 pr_err("Unknown opcode %02x\n", insn->code); 1581 return -1; 1582 } 1583 1584 if (probe_prg != -1) { 1585 /* 1586 * Handlers of certain exceptions leave psw.addr pointing to 1587 * the instruction directly after the failing one. Therefore, 1588 * create two exception table entries and also add a nop in 1589 * case two probing instructions come directly after each 1590 * other. 1591 */ 1592 nop_prg = jit->prg; 1593 /* bcr 0,%0 */ 1594 _EMIT2(0x0700); 1595 err = bpf_jit_probe_mem(jit, fp, probe_prg, nop_prg); 1596 if (err < 0) 1597 return err; 1598 } 1599 1600 return insn_count; 1601 } 1602 1603 /* 1604 * Return whether new i-th instruction address does not violate any invariant 1605 */ 1606 static bool bpf_is_new_addr_sane(struct bpf_jit *jit, int i) 1607 { 1608 /* On the first pass anything goes */ 1609 if (is_first_pass(jit)) 1610 return true; 1611 1612 /* The codegen pass must not change anything */ 1613 if (is_codegen_pass(jit)) 1614 return jit->addrs[i] == jit->prg; 1615 1616 /* Passes in between must not increase code size */ 1617 return jit->addrs[i] >= jit->prg; 1618 } 1619 1620 /* 1621 * Update the address of i-th instruction 1622 */ 1623 static int bpf_set_addr(struct bpf_jit *jit, int i) 1624 { 1625 int delta; 1626 1627 if (is_codegen_pass(jit)) { 1628 delta = jit->prg - jit->addrs[i]; 1629 if (delta < 0) 1630 bpf_skip(jit, -delta); 1631 } 1632 if (WARN_ON_ONCE(!bpf_is_new_addr_sane(jit, i))) 1633 return -1; 1634 jit->addrs[i] = jit->prg; 1635 return 0; 1636 } 1637 1638 /* 1639 * Compile eBPF program into s390x code 1640 */ 1641 static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp, 1642 bool extra_pass, u32 stack_depth) 1643 { 1644 int i, insn_count, lit32_size, lit64_size; 1645 1646 jit->lit32 = jit->lit32_start; 1647 jit->lit64 = jit->lit64_start; 1648 jit->prg = 0; 1649 jit->excnt = 0; 1650 1651 bpf_jit_prologue(jit, stack_depth); 1652 if (bpf_set_addr(jit, 0) < 0) 1653 return -1; 1654 for (i = 0; i < fp->len; i += insn_count) { 1655 insn_count = bpf_jit_insn(jit, fp, i, extra_pass, stack_depth); 1656 if (insn_count < 0) 1657 return -1; 1658 /* Next instruction address */ 1659 if (bpf_set_addr(jit, i + insn_count) < 0) 1660 return -1; 1661 } 1662 bpf_jit_epilogue(jit, stack_depth); 1663 1664 lit32_size = jit->lit32 - jit->lit32_start; 1665 lit64_size = jit->lit64 - jit->lit64_start; 1666 jit->lit32_start = jit->prg; 1667 if (lit32_size) 1668 jit->lit32_start = ALIGN(jit->lit32_start, 4); 1669 jit->lit64_start = jit->lit32_start + lit32_size; 1670 if (lit64_size) 1671 jit->lit64_start = ALIGN(jit->lit64_start, 8); 1672 jit->size = jit->lit64_start + lit64_size; 1673 jit->size_prg = jit->prg; 1674 1675 if (WARN_ON_ONCE(fp->aux->extable && 1676 jit->excnt != fp->aux->num_exentries)) 1677 /* Verifier bug - too many entries. */ 1678 return -1; 1679 1680 return 0; 1681 } 1682 1683 bool bpf_jit_needs_zext(void) 1684 { 1685 return true; 1686 } 1687 1688 struct s390_jit_data { 1689 struct bpf_binary_header *header; 1690 struct bpf_jit ctx; 1691 int pass; 1692 }; 1693 1694 static struct bpf_binary_header *bpf_jit_alloc(struct bpf_jit *jit, 1695 struct bpf_prog *fp) 1696 { 1697 struct bpf_binary_header *header; 1698 u32 extable_size; 1699 u32 code_size; 1700 1701 /* We need two entries per insn. */ 1702 fp->aux->num_exentries *= 2; 1703 1704 code_size = roundup(jit->size, 1705 __alignof__(struct exception_table_entry)); 1706 extable_size = fp->aux->num_exentries * 1707 sizeof(struct exception_table_entry); 1708 header = bpf_jit_binary_alloc(code_size + extable_size, &jit->prg_buf, 1709 8, jit_fill_hole); 1710 if (!header) 1711 return NULL; 1712 fp->aux->extable = (struct exception_table_entry *) 1713 (jit->prg_buf + code_size); 1714 return header; 1715 } 1716 1717 /* 1718 * Compile eBPF program "fp" 1719 */ 1720 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) 1721 { 1722 u32 stack_depth = round_up(fp->aux->stack_depth, 8); 1723 struct bpf_prog *tmp, *orig_fp = fp; 1724 struct bpf_binary_header *header; 1725 struct s390_jit_data *jit_data; 1726 bool tmp_blinded = false; 1727 bool extra_pass = false; 1728 struct bpf_jit jit; 1729 int pass; 1730 1731 if (!fp->jit_requested) 1732 return orig_fp; 1733 1734 tmp = bpf_jit_blind_constants(fp); 1735 /* 1736 * If blinding was requested and we failed during blinding, 1737 * we must fall back to the interpreter. 1738 */ 1739 if (IS_ERR(tmp)) 1740 return orig_fp; 1741 if (tmp != fp) { 1742 tmp_blinded = true; 1743 fp = tmp; 1744 } 1745 1746 jit_data = fp->aux->jit_data; 1747 if (!jit_data) { 1748 jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); 1749 if (!jit_data) { 1750 fp = orig_fp; 1751 goto out; 1752 } 1753 fp->aux->jit_data = jit_data; 1754 } 1755 if (jit_data->ctx.addrs) { 1756 jit = jit_data->ctx; 1757 header = jit_data->header; 1758 extra_pass = true; 1759 pass = jit_data->pass + 1; 1760 goto skip_init_ctx; 1761 } 1762 1763 memset(&jit, 0, sizeof(jit)); 1764 jit.addrs = kvcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL); 1765 if (jit.addrs == NULL) { 1766 fp = orig_fp; 1767 goto out; 1768 } 1769 /* 1770 * Three initial passes: 1771 * - 1/2: Determine clobbered registers 1772 * - 3: Calculate program size and addrs arrray 1773 */ 1774 for (pass = 1; pass <= 3; pass++) { 1775 if (bpf_jit_prog(&jit, fp, extra_pass, stack_depth)) { 1776 fp = orig_fp; 1777 goto free_addrs; 1778 } 1779 } 1780 /* 1781 * Final pass: Allocate and generate program 1782 */ 1783 header = bpf_jit_alloc(&jit, fp); 1784 if (!header) { 1785 fp = orig_fp; 1786 goto free_addrs; 1787 } 1788 skip_init_ctx: 1789 if (bpf_jit_prog(&jit, fp, extra_pass, stack_depth)) { 1790 bpf_jit_binary_free(header); 1791 fp = orig_fp; 1792 goto free_addrs; 1793 } 1794 if (bpf_jit_enable > 1) { 1795 bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf); 1796 print_fn_code(jit.prg_buf, jit.size_prg); 1797 } 1798 if (!fp->is_func || extra_pass) { 1799 bpf_jit_binary_lock_ro(header); 1800 } else { 1801 jit_data->header = header; 1802 jit_data->ctx = jit; 1803 jit_data->pass = pass; 1804 } 1805 fp->bpf_func = (void *) jit.prg_buf; 1806 fp->jited = 1; 1807 fp->jited_len = jit.size; 1808 1809 if (!fp->is_func || extra_pass) { 1810 bpf_prog_fill_jited_linfo(fp, jit.addrs + 1); 1811 free_addrs: 1812 kvfree(jit.addrs); 1813 kfree(jit_data); 1814 fp->aux->jit_data = NULL; 1815 } 1816 out: 1817 if (tmp_blinded) 1818 bpf_jit_prog_release_other(fp, fp == orig_fp ? 1819 tmp : orig_fp); 1820 return fp; 1821 } 1822