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/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <sys/param.h> 41 #include <sys/kernel.h> 42 #include <sys/systm.h> 43 #include <sys/exec.h> 44 #include <sys/imgact.h> 45 #include <sys/linker.h> 46 #include <sys/proc.h> 47 #include <sys/reg.h> 48 #include <sys/sysctl.h> 49 #include <sys/sysent.h> 50 #include <sys/imgact_elf.h> 51 #include <sys/syscall.h> 52 #include <sys/signalvar.h> 53 #include <sys/vnode.h> 54 55 #include <vm/vm.h> 56 #include <vm/pmap.h> 57 #include <vm/vm_param.h> 58 59 #include <machine/elf.h> 60 #include <machine/md_var.h> 61 62 static const char *riscv_machine_arch(struct proc *p); 63 64 u_long elf_hwcap; 65 66 static struct sysentvec elf64_freebsd_sysvec = { 67 .sv_size = SYS_MAXSYSCALL, 68 .sv_table = sysent, 69 .sv_transtrap = NULL, 70 .sv_fixup = __elfN(freebsd_fixup), 71 .sv_sendsig = sendsig, 72 .sv_sigcode = sigcode, 73 .sv_szsigcode = &szsigcode, 74 .sv_name = "FreeBSD ELF64", 75 .sv_coredump = __elfN(coredump), 76 .sv_elf_core_osabi = ELFOSABI_FREEBSD, 77 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR, 78 .sv_elf_core_prepare_notes = __elfN(prepare_notes), 79 .sv_imgact_try = NULL, 80 .sv_minsigstksz = MINSIGSTKSZ, 81 .sv_minuser = VM_MIN_ADDRESS, 82 .sv_maxuser = 0, /* Filled in during boot. */ 83 .sv_usrstack = 0, /* Filled in during boot. */ 84 .sv_psstrings = 0, /* Filled in during boot. */ 85 .sv_psstringssz = sizeof(struct ps_strings), 86 .sv_stackprot = VM_PROT_READ | VM_PROT_WRITE, 87 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs), 88 .sv_copyout_strings = exec_copyout_strings, 89 .sv_setregs = exec_setregs, 90 .sv_fixlimit = NULL, 91 .sv_maxssiz = NULL, 92 .sv_flags = SV_ABI_FREEBSD | SV_LP64 | SV_SHP | SV_TIMEKEEP | 93 SV_ASLR | SV_RNG_SEED_VER, 94 .sv_set_syscall_retval = cpu_set_syscall_retval, 95 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 96 .sv_syscallnames = syscallnames, 97 .sv_shared_page_base = 0, /* Filled in during boot. */ 98 .sv_shared_page_len = PAGE_SIZE, 99 .sv_schedtail = NULL, 100 .sv_thread_detach = NULL, 101 .sv_trap = NULL, 102 .sv_hwcap = &elf_hwcap, 103 .sv_machine_arch = riscv_machine_arch, 104 .sv_onexec_old = exec_onexec_old, 105 .sv_onexit = exit_onexit, 106 .sv_regset_begin = SET_BEGIN(__elfN(regset)), 107 .sv_regset_end = SET_LIMIT(__elfN(regset)), 108 }; 109 INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec); 110 111 static const char * 112 riscv_machine_arch(struct proc *p) 113 { 114 115 if ((p->p_elf_flags & EF_RISCV_FLOAT_ABI_MASK) == 116 EF_RISCV_FLOAT_ABI_SOFT) 117 return (MACHINE_ARCH "sf"); 118 return (MACHINE_ARCH); 119 } 120 121 static Elf64_Brandinfo freebsd_brand_info = { 122 .brand = ELFOSABI_FREEBSD, 123 .machine = EM_RISCV, 124 .compat_3_brand = "FreeBSD", 125 .emul_path = NULL, 126 .interp_path = "/libexec/ld-elf.so.1", 127 .sysvec = &elf64_freebsd_sysvec, 128 .interp_newpath = NULL, 129 .brand_note = &elf64_freebsd_brandnote, 130 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 131 }; 132 SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST, 133 (sysinit_cfunc_t)elf64_insert_brand_entry, &freebsd_brand_info); 134 135 static void 136 elf64_register_sysvec(void *arg) 137 { 138 struct sysentvec *sv; 139 140 sv = arg; 141 switch (pmap_mode) { 142 case PMAP_MODE_SV48: 143 sv->sv_maxuser = VM_MAX_USER_ADDRESS_SV48; 144 sv->sv_usrstack = USRSTACK_SV48; 145 sv->sv_psstrings = PS_STRINGS_SV48; 146 sv->sv_shared_page_base = SHAREDPAGE_SV48; 147 break; 148 case PMAP_MODE_SV39: 149 sv->sv_maxuser = VM_MAX_USER_ADDRESS_SV39; 150 sv->sv_usrstack = USRSTACK_SV39; 151 sv->sv_psstrings = PS_STRINGS_SV39; 152 sv->sv_shared_page_base = SHAREDPAGE_SV39; 153 break; 154 } 155 } 156 SYSINIT(elf64_register_sysvec, SI_SUB_VM, SI_ORDER_ANY, elf64_register_sysvec, 157 &elf64_freebsd_sysvec); 158 159 static bool debug_kld; 160 SYSCTL_BOOL(_debug, OID_AUTO, kld_reloc, CTLFLAG_RW, &debug_kld, 0, 161 "Activate debug prints in elf_reloc_internal()"); 162 163 struct type2str_ent { 164 int type; 165 const char *str; 166 }; 167 168 void 169 elf64_dump_thread(struct thread *td, void *dst, size_t *off) 170 { 171 172 } 173 174 /* 175 * Following 4 functions are used to manipulate bits on 32bit integer value. 176 * FIXME: I implemetend for ease-to-understand rather than for well-optimized. 177 */ 178 static uint32_t 179 gen_bitmask(int msb, int lsb) 180 { 181 uint32_t mask; 182 183 if (msb == sizeof(mask) * 8 - 1) 184 mask = ~0; 185 else 186 mask = (1U << (msb + 1)) - 1; 187 188 if (lsb > 0) 189 mask &= ~((1U << lsb) - 1); 190 191 return (mask); 192 } 193 194 static uint32_t 195 extract_bits(uint32_t x, int msb, int lsb) 196 { 197 uint32_t mask; 198 199 mask = gen_bitmask(msb, lsb); 200 201 x &= mask; 202 x >>= lsb; 203 204 return (x); 205 } 206 207 static uint32_t 208 insert_bits(uint32_t d, uint32_t s, int msb, int lsb) 209 { 210 uint32_t mask; 211 212 mask = gen_bitmask(msb, lsb); 213 214 d &= ~mask; 215 216 s <<= lsb; 217 s &= mask; 218 219 return (d | s); 220 } 221 222 static uint32_t 223 insert_imm(uint32_t insn, uint32_t imm, int imm_msb, int imm_lsb, 224 int insn_lsb) 225 { 226 int insn_msb; 227 uint32_t v; 228 229 v = extract_bits(imm, imm_msb, imm_lsb); 230 insn_msb = (imm_msb - imm_lsb) + insn_lsb; 231 232 return (insert_bits(insn, v, insn_msb, insn_lsb)); 233 } 234 235 /* 236 * The RISC-V ISA is designed so that all of immediate values are 237 * sign-extended. 238 * An immediate value is sometimes generated at runtime by adding 239 * 12bit sign integer and 20bit signed integer. This requests 20bit 240 * immediate value to be ajusted if the MSB of the 12bit immediate 241 * value is asserted (sign-extended value is treated as negative value). 242 * 243 * For example, 0x123800 can be calculated by adding upper 20 bit of 244 * 0x124000 and sign-extended 12bit immediate whose bit pattern is 245 * 0x800 as follows: 246 * 0x123800 247 * = 0x123000 + 0x800 248 * = (0x123000 + 0x1000) + (-0x1000 + 0x800) 249 * = (0x123000 + 0x1000) + (0xff...ff800) 250 * = 0x124000 + sign-extention(0x800) 251 */ 252 static uint32_t 253 calc_hi20_imm(uint32_t value) 254 { 255 /* 256 * There is the arithmetical hack that can remove conditional 257 * statement. But I implement it in straightforward way. 258 */ 259 if ((value & 0x800) != 0) 260 value += 0x1000; 261 return (value & ~0xfff); 262 } 263 264 static const struct type2str_ent t2s[] = { 265 { R_RISCV_NONE, "R_RISCV_NONE" }, 266 { R_RISCV_64, "R_RISCV_64" }, 267 { R_RISCV_JUMP_SLOT, "R_RISCV_JUMP_SLOT" }, 268 { R_RISCV_RELATIVE, "R_RISCV_RELATIVE" }, 269 { R_RISCV_JAL, "R_RISCV_JAL" }, 270 { R_RISCV_CALL, "R_RISCV_CALL" }, 271 { R_RISCV_PCREL_HI20, "R_RISCV_PCREL_HI20" }, 272 { R_RISCV_PCREL_LO12_I, "R_RISCV_PCREL_LO12_I" }, 273 { R_RISCV_PCREL_LO12_S, "R_RISCV_PCREL_LO12_S" }, 274 { R_RISCV_HI20, "R_RISCV_HI20" }, 275 { R_RISCV_LO12_I, "R_RISCV_LO12_I" }, 276 { R_RISCV_LO12_S, "R_RISCV_LO12_S" }, 277 }; 278 279 static const char * 280 reloctype_to_str(int type) 281 { 282 int i; 283 284 for (i = 0; i < sizeof(t2s) / sizeof(t2s[0]); ++i) { 285 if (type == t2s[i].type) 286 return t2s[i].str; 287 } 288 289 return "*unknown*"; 290 } 291 292 bool 293 elf_is_ifunc_reloc(Elf_Size r_info __unused) 294 { 295 296 return (false); 297 } 298 299 /* 300 * Currently kernel loadable module for RISCV is compiled with -fPIC option. 301 * (see also additional CFLAGS definition for RISCV in sys/conf/kmod.mk) 302 * Only R_RISCV_64, R_RISCV_JUMP_SLOT and RISCV_RELATIVE are emitted in 303 * the module. Other relocations will be processed when kernel loadable 304 * modules are built in non-PIC. 305 * 306 * FIXME: only RISCV64 is supported. 307 */ 308 static int 309 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 310 int type, int local, elf_lookup_fn lookup) 311 { 312 Elf_Size rtype, symidx; 313 const Elf_Rela *rela; 314 Elf_Addr val, addr; 315 Elf64_Addr *where; 316 Elf_Addr addend; 317 uint32_t before32_1; 318 uint32_t before32; 319 uint64_t before64; 320 uint32_t *insn32p; 321 uint32_t imm20; 322 int error; 323 324 switch (type) { 325 case ELF_RELOC_RELA: 326 rela = (const Elf_Rela *)data; 327 where = (Elf_Addr *)(relocbase + rela->r_offset); 328 insn32p = (uint32_t *)where; 329 addend = rela->r_addend; 330 rtype = ELF_R_TYPE(rela->r_info); 331 symidx = ELF_R_SYM(rela->r_info); 332 break; 333 default: 334 printf("%s:%d unknown reloc type %d\n", 335 __FUNCTION__, __LINE__, type); 336 return (-1); 337 } 338 339 switch (rtype) { 340 case R_RISCV_NONE: 341 break; 342 343 case R_RISCV_64: 344 case R_RISCV_JUMP_SLOT: 345 error = lookup(lf, symidx, 1, &addr); 346 if (error != 0) 347 return (-1); 348 349 val = addr; 350 before64 = *where; 351 if (*where != val) 352 *where = val; 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_RELATIVE: 360 before64 = *where; 361 *where = elf_relocaddr(lf, relocbase + addend); 362 if (debug_kld) 363 printf("%p %c %-24s %016lx -> %016lx\n", where, 364 (local ? 'l' : 'g'), reloctype_to_str(rtype), 365 before64, *where); 366 break; 367 368 case R_RISCV_JAL: 369 error = lookup(lf, symidx, 1, &addr); 370 if (error != 0) 371 return (-1); 372 373 val = addr - (Elf_Addr)where; 374 if (val <= -(1UL << 20) || (1UL << 20) <= val) { 375 printf("kldload: huge offset against R_RISCV_JAL\n"); 376 return (-1); 377 } 378 379 before32 = *insn32p; 380 *insn32p = insert_imm(*insn32p, val, 20, 20, 31); 381 *insn32p = insert_imm(*insn32p, val, 10, 1, 21); 382 *insn32p = insert_imm(*insn32p, val, 11, 11, 20); 383 *insn32p = insert_imm(*insn32p, val, 19, 12, 12); 384 if (debug_kld) 385 printf("%p %c %-24s %08x -> %08x\n", where, 386 (local ? 'l' : 'g'), reloctype_to_str(rtype), 387 before32, *insn32p); 388 break; 389 390 case R_RISCV_CALL: 391 /* 392 * R_RISCV_CALL relocates 8-byte region that consists 393 * of the sequence of AUIPC and JALR. 394 */ 395 /* Calculate and check the pc relative offset. */ 396 error = lookup(lf, symidx, 1, &addr); 397 if (error != 0) 398 return (-1); 399 400 val = addr - (Elf_Addr)where; 401 if (val <= -(1UL << 32) || (1UL << 32) <= val) { 402 printf("kldload: huge offset against R_RISCV_CALL\n"); 403 return (-1); 404 } 405 406 /* Relocate AUIPC. */ 407 before32 = insn32p[0]; 408 imm20 = calc_hi20_imm(val); 409 insn32p[0] = insert_imm(insn32p[0], imm20, 31, 12, 12); 410 411 /* Relocate JALR. */ 412 before32_1 = insn32p[1]; 413 insn32p[1] = insert_imm(insn32p[1], val, 11, 0, 20); 414 if (debug_kld) 415 printf("%p %c %-24s %08x %08x -> %08x %08x\n", where, 416 (local ? 'l' : 'g'), reloctype_to_str(rtype), 417 before32, insn32p[0], before32_1, insn32p[1]); 418 break; 419 420 case R_RISCV_PCREL_HI20: 421 error = lookup(lf, symidx, 1, &addr); 422 if (error != 0) 423 return (-1); 424 425 val = addr - (Elf_Addr)where; 426 insn32p = (uint32_t *)where; 427 before32 = *insn32p; 428 imm20 = calc_hi20_imm(val); 429 *insn32p = insert_imm(*insn32p, imm20, 31, 12, 12); 430 if (debug_kld) 431 printf("%p %c %-24s %08x -> %08x\n", where, 432 (local ? 'l' : 'g'), reloctype_to_str(rtype), 433 before32, *insn32p); 434 break; 435 436 case R_RISCV_PCREL_LO12_I: 437 error = lookup(lf, symidx, 1, &addr); 438 if (error != 0) 439 return (-1); 440 441 val = addr - (Elf_Addr)where; 442 insn32p = (uint32_t *)where; 443 before32 = *insn32p; 444 *insn32p = insert_imm(*insn32p, addr, 11, 0, 20); 445 if (debug_kld) 446 printf("%p %c %-24s %08x -> %08x\n", where, 447 (local ? 'l' : 'g'), reloctype_to_str(rtype), 448 before32, *insn32p); 449 break; 450 451 case R_RISCV_PCREL_LO12_S: 452 error = lookup(lf, symidx, 1, &addr); 453 if (error != 0) 454 return (-1); 455 456 val = addr - (Elf_Addr)where; 457 insn32p = (uint32_t *)where; 458 before32 = *insn32p; 459 *insn32p = insert_imm(*insn32p, addr, 11, 5, 25); 460 *insn32p = insert_imm(*insn32p, addr, 4, 0, 7); 461 if (debug_kld) 462 printf("%p %c %-24s %08x -> %08x\n", where, 463 (local ? 'l' : 'g'), reloctype_to_str(rtype), 464 before32, *insn32p); 465 break; 466 467 case R_RISCV_HI20: 468 error = lookup(lf, symidx, 1, &addr); 469 if (error != 0) 470 return (-1); 471 472 val = addr; 473 insn32p = (uint32_t *)where; 474 before32 = *insn32p; 475 imm20 = calc_hi20_imm(val); 476 *insn32p = insert_imm(*insn32p, imm20, 31, 12, 12); 477 if (debug_kld) 478 printf("%p %c %-24s %08x -> %08x\n", where, 479 (local ? 'l' : 'g'), reloctype_to_str(rtype), 480 before32, *insn32p); 481 break; 482 483 case R_RISCV_LO12_I: 484 error = lookup(lf, symidx, 1, &addr); 485 if (error != 0) 486 return (-1); 487 488 val = addr; 489 insn32p = (uint32_t *)where; 490 before32 = *insn32p; 491 *insn32p = insert_imm(*insn32p, addr, 11, 0, 20); 492 if (debug_kld) 493 printf("%p %c %-24s %08x -> %08x\n", where, 494 (local ? 'l' : 'g'), reloctype_to_str(rtype), 495 before32, *insn32p); 496 break; 497 498 case R_RISCV_LO12_S: 499 error = lookup(lf, symidx, 1, &addr); 500 if (error != 0) 501 return (-1); 502 503 val = addr; 504 insn32p = (uint32_t *)where; 505 before32 = *insn32p; 506 *insn32p = insert_imm(*insn32p, addr, 11, 5, 25); 507 *insn32p = insert_imm(*insn32p, addr, 4, 0, 7); 508 if (debug_kld) 509 printf("%p %c %-24s %08x -> %08x\n", where, 510 (local ? 'l' : 'g'), reloctype_to_str(rtype), 511 before32, *insn32p); 512 break; 513 514 default: 515 printf("kldload: unexpected relocation type %ld, " 516 "symbol index %ld\n", rtype, symidx); 517 return (-1); 518 } 519 520 return (0); 521 } 522 523 int 524 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 525 elf_lookup_fn lookup) 526 { 527 528 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 529 } 530 531 int 532 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 533 int type, elf_lookup_fn lookup) 534 { 535 536 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 537 } 538 539 int 540 elf_cpu_load_file(linker_file_t lf __unused) 541 { 542 543 return (0); 544 } 545 546 int 547 elf_cpu_unload_file(linker_file_t lf __unused) 548 { 549 550 return (0); 551 } 552 553 int 554 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused) 555 { 556 557 return (0); 558 } 559