1 /*- 2 * Copyright 1996-1998 John D. Polstra. 3 * Copyright (c) 2015 Ruslan Bukin <br@bsdpad.com> 4 * Copyright (c) 2016 Yukishige Shibata <y-shibat@mtd.biglobe.ne.jp> 5 * All rights reserved. 6 * 7 * Portions of this software were developed by SRI International and the 8 * University of Cambridge Computer Laboratory under DARPA/AFRL contract 9 * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme. 10 * 11 * Portions of this software were developed by the University of Cambridge 12 * Computer Laboratory as part of the CTSRD Project, with support from the 13 * UK Higher Education Innovation Fund (HEIF). 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #include <sys/param.h> 38 #include <sys/kernel.h> 39 #include <sys/systm.h> 40 #include <sys/exec.h> 41 #include <sys/imgact.h> 42 #include <sys/linker.h> 43 #include <sys/proc.h> 44 #include <sys/reg.h> 45 #include <sys/sysctl.h> 46 #include <sys/sysent.h> 47 #include <sys/imgact_elf.h> 48 #include <sys/syscall.h> 49 #include <sys/signalvar.h> 50 #include <sys/vnode.h> 51 52 #include <vm/vm.h> 53 #include <vm/pmap.h> 54 #include <vm/vm_param.h> 55 56 #include <machine/elf.h> 57 #include <machine/md_var.h> 58 59 u_long elf_hwcap; 60 61 static struct sysentvec elf64_freebsd_sysvec = { 62 .sv_size = SYS_MAXSYSCALL, 63 .sv_table = sysent, 64 .sv_fixup = __elfN(freebsd_fixup), 65 .sv_sendsig = sendsig, 66 .sv_sigcode = sigcode, 67 .sv_szsigcode = &szsigcode, 68 .sv_name = "FreeBSD ELF64", 69 .sv_coredump = __elfN(coredump), 70 .sv_elf_core_osabi = ELFOSABI_FREEBSD, 71 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR, 72 .sv_elf_core_prepare_notes = __elfN(prepare_notes), 73 .sv_minsigstksz = MINSIGSTKSZ, 74 .sv_minuser = VM_MIN_ADDRESS, 75 .sv_maxuser = 0, /* Filled in during boot. */ 76 .sv_usrstack = 0, /* Filled in during boot. */ 77 .sv_psstrings = 0, /* Filled in during boot. */ 78 .sv_psstringssz = sizeof(struct ps_strings), 79 .sv_stackprot = VM_PROT_READ | VM_PROT_WRITE, 80 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs), 81 .sv_copyout_strings = exec_copyout_strings, 82 .sv_setregs = exec_setregs, 83 .sv_fixlimit = NULL, 84 .sv_maxssiz = NULL, 85 .sv_flags = SV_ABI_FREEBSD | SV_LP64 | SV_SHP | SV_TIMEKEEP | 86 SV_ASLR | SV_RNG_SEED_VER | SV_SIGSYS, 87 .sv_set_syscall_retval = cpu_set_syscall_retval, 88 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 89 .sv_syscallnames = syscallnames, 90 .sv_shared_page_base = 0, /* Filled in during boot. */ 91 .sv_shared_page_len = PAGE_SIZE, 92 .sv_schedtail = NULL, 93 .sv_thread_detach = NULL, 94 .sv_trap = NULL, 95 .sv_hwcap = &elf_hwcap, 96 .sv_onexec_old = exec_onexec_old, 97 .sv_onexit = exit_onexit, 98 .sv_regset_begin = SET_BEGIN(__elfN(regset)), 99 .sv_regset_end = SET_LIMIT(__elfN(regset)), 100 }; 101 INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec); 102 103 static Elf64_Brandinfo freebsd_brand_info = { 104 .brand = ELFOSABI_FREEBSD, 105 .machine = EM_RISCV, 106 .compat_3_brand = "FreeBSD", 107 .interp_path = "/libexec/ld-elf.so.1", 108 .sysvec = &elf64_freebsd_sysvec, 109 .interp_newpath = NULL, 110 .brand_note = &elf64_freebsd_brandnote, 111 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 112 }; 113 SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST, 114 (sysinit_cfunc_t)elf64_insert_brand_entry, &freebsd_brand_info); 115 116 static void 117 elf64_register_sysvec(void *arg) 118 { 119 struct sysentvec *sv; 120 121 sv = arg; 122 switch (pmap_mode) { 123 case PMAP_MODE_SV48: 124 sv->sv_maxuser = VM_MAX_USER_ADDRESS_SV48; 125 sv->sv_usrstack = USRSTACK_SV48; 126 sv->sv_psstrings = PS_STRINGS_SV48; 127 sv->sv_shared_page_base = SHAREDPAGE_SV48; 128 break; 129 case PMAP_MODE_SV39: 130 sv->sv_maxuser = VM_MAX_USER_ADDRESS_SV39; 131 sv->sv_usrstack = USRSTACK_SV39; 132 sv->sv_psstrings = PS_STRINGS_SV39; 133 sv->sv_shared_page_base = SHAREDPAGE_SV39; 134 break; 135 } 136 } 137 SYSINIT(elf64_register_sysvec, SI_SUB_VM, SI_ORDER_ANY, elf64_register_sysvec, 138 &elf64_freebsd_sysvec); 139 140 static bool debug_kld; 141 SYSCTL_BOOL(_debug, OID_AUTO, kld_reloc, CTLFLAG_RW, &debug_kld, 0, 142 "Activate debug prints in elf_reloc_internal()"); 143 144 struct type2str_ent { 145 int type; 146 const char *str; 147 }; 148 149 void 150 elf64_dump_thread(struct thread *td, void *dst, size_t *off) 151 { 152 153 } 154 155 /* 156 * Following 4 functions are used to manipulate bits on 32bit integer value. 157 * FIXME: I implemetend for ease-to-understand rather than for well-optimized. 158 */ 159 static uint32_t 160 gen_bitmask(int msb, int lsb) 161 { 162 uint32_t mask; 163 164 if (msb == sizeof(mask) * 8 - 1) 165 mask = ~0; 166 else 167 mask = (1U << (msb + 1)) - 1; 168 169 if (lsb > 0) 170 mask &= ~((1U << lsb) - 1); 171 172 return (mask); 173 } 174 175 static uint32_t 176 extract_bits(uint32_t x, int msb, int lsb) 177 { 178 uint32_t mask; 179 180 mask = gen_bitmask(msb, lsb); 181 182 x &= mask; 183 x >>= lsb; 184 185 return (x); 186 } 187 188 static uint32_t 189 insert_bits(uint32_t d, uint32_t s, int msb, int lsb) 190 { 191 uint32_t mask; 192 193 mask = gen_bitmask(msb, lsb); 194 195 d &= ~mask; 196 197 s <<= lsb; 198 s &= mask; 199 200 return (d | s); 201 } 202 203 static uint32_t 204 insert_imm(uint32_t insn, uint32_t imm, int imm_msb, int imm_lsb, 205 int insn_lsb) 206 { 207 int insn_msb; 208 uint32_t v; 209 210 v = extract_bits(imm, imm_msb, imm_lsb); 211 insn_msb = (imm_msb - imm_lsb) + insn_lsb; 212 213 return (insert_bits(insn, v, insn_msb, insn_lsb)); 214 } 215 216 /* 217 * The RISC-V ISA is designed so that all of immediate values are 218 * sign-extended. 219 * An immediate value is sometimes generated at runtime by adding 220 * 12bit sign integer and 20bit signed integer. This requests 20bit 221 * immediate value to be ajusted if the MSB of the 12bit immediate 222 * value is asserted (sign-extended value is treated as negative value). 223 * 224 * For example, 0x123800 can be calculated by adding upper 20 bit of 225 * 0x124000 and sign-extended 12bit immediate whose bit pattern is 226 * 0x800 as follows: 227 * 0x123800 228 * = 0x123000 + 0x800 229 * = (0x123000 + 0x1000) + (-0x1000 + 0x800) 230 * = (0x123000 + 0x1000) + (0xff...ff800) 231 * = 0x124000 + sign-extention(0x800) 232 */ 233 static uint32_t 234 calc_hi20_imm(uint32_t value) 235 { 236 /* 237 * There is the arithmetical hack that can remove conditional 238 * statement. But I implement it in straightforward way. 239 */ 240 if ((value & 0x800) != 0) 241 value += 0x1000; 242 return (value & ~0xfff); 243 } 244 245 static const struct type2str_ent t2s[] = { 246 { R_RISCV_NONE, "R_RISCV_NONE" }, 247 { R_RISCV_64, "R_RISCV_64" }, 248 { R_RISCV_JUMP_SLOT, "R_RISCV_JUMP_SLOT" }, 249 { R_RISCV_RELATIVE, "R_RISCV_RELATIVE" }, 250 { R_RISCV_JAL, "R_RISCV_JAL" }, 251 { R_RISCV_CALL, "R_RISCV_CALL" }, 252 { R_RISCV_PCREL_HI20, "R_RISCV_PCREL_HI20" }, 253 { R_RISCV_PCREL_LO12_I, "R_RISCV_PCREL_LO12_I" }, 254 { R_RISCV_PCREL_LO12_S, "R_RISCV_PCREL_LO12_S" }, 255 { R_RISCV_HI20, "R_RISCV_HI20" }, 256 { R_RISCV_LO12_I, "R_RISCV_LO12_I" }, 257 { R_RISCV_LO12_S, "R_RISCV_LO12_S" }, 258 }; 259 260 static const char * 261 reloctype_to_str(int type) 262 { 263 int i; 264 265 for (i = 0; i < sizeof(t2s) / sizeof(t2s[0]); ++i) { 266 if (type == t2s[i].type) 267 return t2s[i].str; 268 } 269 270 return "*unknown*"; 271 } 272 273 bool 274 elf_is_ifunc_reloc(Elf_Size r_info __unused) 275 { 276 277 return (false); 278 } 279 280 /* 281 * Currently kernel loadable module for RISCV is compiled with -fPIC option. 282 * (see also additional CFLAGS definition for RISCV in sys/conf/kmod.mk) 283 * Only R_RISCV_64, R_RISCV_JUMP_SLOT and RISCV_RELATIVE are emitted in 284 * the module. Other relocations will be processed when kernel loadable 285 * modules are built in non-PIC. 286 * 287 * FIXME: only RISCV64 is supported. 288 */ 289 static int 290 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 291 int type, int local, elf_lookup_fn lookup) 292 { 293 Elf_Size rtype, symidx; 294 const Elf_Rela *rela; 295 Elf_Addr val, addr; 296 Elf64_Addr *where; 297 Elf_Addr addend; 298 uint32_t before32_1; 299 uint32_t before32; 300 uint64_t before64; 301 uint32_t *insn32p; 302 uint32_t imm20; 303 int error; 304 305 switch (type) { 306 case ELF_RELOC_RELA: 307 rela = (const Elf_Rela *)data; 308 where = (Elf_Addr *)(relocbase + rela->r_offset); 309 insn32p = (uint32_t *)where; 310 addend = rela->r_addend; 311 rtype = ELF_R_TYPE(rela->r_info); 312 symidx = ELF_R_SYM(rela->r_info); 313 break; 314 default: 315 printf("%s:%d unknown reloc type %d\n", 316 __FUNCTION__, __LINE__, type); 317 return (-1); 318 } 319 320 switch (rtype) { 321 case R_RISCV_NONE: 322 break; 323 324 case R_RISCV_64: 325 error = lookup(lf, symidx, 1, &addr); 326 if (error != 0) 327 return (-1); 328 329 before64 = *where; 330 *where = addr + addend; 331 if (debug_kld) 332 printf("%p %c %-24s %016lx -> %016lx\n", where, 333 (local ? 'l' : 'g'), reloctype_to_str(rtype), 334 before64, *where); 335 break; 336 337 case R_RISCV_JUMP_SLOT: 338 error = lookup(lf, symidx, 1, &addr); 339 if (error != 0) 340 return (-1); 341 342 before64 = *where; 343 *where = addr; 344 if (debug_kld) 345 printf("%p %c %-24s %016lx -> %016lx\n", where, 346 (local ? 'l' : 'g'), reloctype_to_str(rtype), 347 before64, *where); 348 break; 349 350 case R_RISCV_RELATIVE: 351 before64 = *where; 352 *where = elf_relocaddr(lf, relocbase + addend); 353 if (debug_kld) 354 printf("%p %c %-24s %016lx -> %016lx\n", where, 355 (local ? 'l' : 'g'), reloctype_to_str(rtype), 356 before64, *where); 357 break; 358 359 case R_RISCV_JAL: 360 error = lookup(lf, symidx, 1, &addr); 361 if (error != 0) 362 return (-1); 363 364 val = addr - (Elf_Addr)where; 365 if (val <= -(1UL << 20) || (1UL << 20) <= val) { 366 printf("kldload: huge offset against R_RISCV_JAL\n"); 367 return (-1); 368 } 369 370 before32 = *insn32p; 371 *insn32p = insert_imm(*insn32p, val, 20, 20, 31); 372 *insn32p = insert_imm(*insn32p, val, 10, 1, 21); 373 *insn32p = insert_imm(*insn32p, val, 11, 11, 20); 374 *insn32p = insert_imm(*insn32p, val, 19, 12, 12); 375 if (debug_kld) 376 printf("%p %c %-24s %08x -> %08x\n", where, 377 (local ? 'l' : 'g'), reloctype_to_str(rtype), 378 before32, *insn32p); 379 break; 380 381 case R_RISCV_CALL: 382 /* 383 * R_RISCV_CALL relocates 8-byte region that consists 384 * of the sequence of AUIPC and JALR. 385 */ 386 /* Calculate and check the pc relative offset. */ 387 error = lookup(lf, symidx, 1, &addr); 388 if (error != 0) 389 return (-1); 390 391 val = addr - (Elf_Addr)where; 392 if (val <= -(1UL << 32) || (1UL << 32) <= val) { 393 printf("kldload: huge offset against R_RISCV_CALL\n"); 394 return (-1); 395 } 396 397 /* Relocate AUIPC. */ 398 before32 = insn32p[0]; 399 imm20 = calc_hi20_imm(val); 400 insn32p[0] = insert_imm(insn32p[0], imm20, 31, 12, 12); 401 402 /* Relocate JALR. */ 403 before32_1 = insn32p[1]; 404 insn32p[1] = insert_imm(insn32p[1], val, 11, 0, 20); 405 if (debug_kld) 406 printf("%p %c %-24s %08x %08x -> %08x %08x\n", where, 407 (local ? 'l' : 'g'), reloctype_to_str(rtype), 408 before32, insn32p[0], before32_1, insn32p[1]); 409 break; 410 411 case R_RISCV_PCREL_HI20: 412 error = lookup(lf, symidx, 1, &addr); 413 if (error != 0) 414 return (-1); 415 416 val = addr - (Elf_Addr)where; 417 insn32p = (uint32_t *)where; 418 before32 = *insn32p; 419 imm20 = calc_hi20_imm(val); 420 *insn32p = insert_imm(*insn32p, imm20, 31, 12, 12); 421 if (debug_kld) 422 printf("%p %c %-24s %08x -> %08x\n", where, 423 (local ? 'l' : 'g'), reloctype_to_str(rtype), 424 before32, *insn32p); 425 break; 426 427 case R_RISCV_PCREL_LO12_I: 428 error = lookup(lf, symidx, 1, &addr); 429 if (error != 0) 430 return (-1); 431 432 val = addr - (Elf_Addr)where; 433 insn32p = (uint32_t *)where; 434 before32 = *insn32p; 435 *insn32p = insert_imm(*insn32p, addr, 11, 0, 20); 436 if (debug_kld) 437 printf("%p %c %-24s %08x -> %08x\n", where, 438 (local ? 'l' : 'g'), reloctype_to_str(rtype), 439 before32, *insn32p); 440 break; 441 442 case R_RISCV_PCREL_LO12_S: 443 error = lookup(lf, symidx, 1, &addr); 444 if (error != 0) 445 return (-1); 446 447 val = addr - (Elf_Addr)where; 448 insn32p = (uint32_t *)where; 449 before32 = *insn32p; 450 *insn32p = insert_imm(*insn32p, addr, 11, 5, 25); 451 *insn32p = insert_imm(*insn32p, addr, 4, 0, 7); 452 if (debug_kld) 453 printf("%p %c %-24s %08x -> %08x\n", where, 454 (local ? 'l' : 'g'), reloctype_to_str(rtype), 455 before32, *insn32p); 456 break; 457 458 case R_RISCV_HI20: 459 error = lookup(lf, symidx, 1, &addr); 460 if (error != 0) 461 return (-1); 462 463 val = addr; 464 insn32p = (uint32_t *)where; 465 before32 = *insn32p; 466 imm20 = calc_hi20_imm(val); 467 *insn32p = insert_imm(*insn32p, imm20, 31, 12, 12); 468 if (debug_kld) 469 printf("%p %c %-24s %08x -> %08x\n", where, 470 (local ? 'l' : 'g'), reloctype_to_str(rtype), 471 before32, *insn32p); 472 break; 473 474 case R_RISCV_LO12_I: 475 error = lookup(lf, symidx, 1, &addr); 476 if (error != 0) 477 return (-1); 478 479 val = addr; 480 insn32p = (uint32_t *)where; 481 before32 = *insn32p; 482 *insn32p = insert_imm(*insn32p, addr, 11, 0, 20); 483 if (debug_kld) 484 printf("%p %c %-24s %08x -> %08x\n", where, 485 (local ? 'l' : 'g'), reloctype_to_str(rtype), 486 before32, *insn32p); 487 break; 488 489 case R_RISCV_LO12_S: 490 error = lookup(lf, symidx, 1, &addr); 491 if (error != 0) 492 return (-1); 493 494 val = addr; 495 insn32p = (uint32_t *)where; 496 before32 = *insn32p; 497 *insn32p = insert_imm(*insn32p, addr, 11, 5, 25); 498 *insn32p = insert_imm(*insn32p, addr, 4, 0, 7); 499 if (debug_kld) 500 printf("%p %c %-24s %08x -> %08x\n", where, 501 (local ? 'l' : 'g'), reloctype_to_str(rtype), 502 before32, *insn32p); 503 break; 504 505 default: 506 printf("kldload: unexpected relocation type %ld, " 507 "symbol index %ld\n", rtype, symidx); 508 return (-1); 509 } 510 511 return (0); 512 } 513 514 int 515 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 516 elf_lookup_fn lookup) 517 { 518 519 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 520 } 521 522 int 523 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 524 int type, elf_lookup_fn lookup) 525 { 526 527 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 528 } 529 530 int 531 elf_cpu_load_file(linker_file_t lf __unused) 532 { 533 534 return (0); 535 } 536 537 int 538 elf_cpu_unload_file(linker_file_t lf __unused) 539 { 540 541 return (0); 542 } 543 544 int 545 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused) 546 { 547 548 return (0); 549 } 550