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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 | // SPDX-License-Identifier: GPL-2.0+ /* * Author: Hanlu Li <lihanlu@loongson.cn> * Huacai Chen <chenhuacai@loongson.cn> * * Copyright (C) 2020-2022 Loongson Technology Corporation Limited */ #define pr_fmt(fmt) "kmod: " fmt #include <linux/moduleloader.h> #include <linux/elf.h> #include <linux/mm.h> #include <linux/numa.h> #include <linux/vmalloc.h> #include <linux/slab.h> #include <linux/fs.h> #include <linux/ftrace.h> #include <linux/string.h> #include <linux/kernel.h> #include <asm/alternative.h> #include <asm/inst.h> #include <asm/unwind.h> static int rela_stack_push(s64 stack_value, s64 *rela_stack, size_t *rela_stack_top) { if (*rela_stack_top >= RELA_STACK_DEPTH) return -ENOEXEC; rela_stack[(*rela_stack_top)++] = stack_value; pr_debug("%s stack_value = 0x%llx\n", __func__, stack_value); return 0; } static int rela_stack_pop(s64 *stack_value, s64 *rela_stack, size_t *rela_stack_top) { if (*rela_stack_top == 0) return -ENOEXEC; *stack_value = rela_stack[--(*rela_stack_top)]; pr_debug("%s stack_value = 0x%llx\n", __func__, *stack_value); return 0; } static int apply_r_larch_none(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { return 0; } static int apply_r_larch_error(struct module *me, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { pr_err("%s: Unsupport relocation type %u, please add its support.\n", me->name, type); return -EINVAL; } static int apply_r_larch_32(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { *location = v; return 0; } static int apply_r_larch_64(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { *(Elf_Addr *)location = v; return 0; } static int apply_r_larch_sop_push_pcrel(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { return rela_stack_push(v - (u64)location, rela_stack, rela_stack_top); } static int apply_r_larch_sop_push_absolute(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { return rela_stack_push(v, rela_stack, rela_stack_top); } static int apply_r_larch_sop_push_dup(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { int err = 0; s64 opr1; err = rela_stack_pop(&opr1, rela_stack, rela_stack_top); if (err) return err; err = rela_stack_push(opr1, rela_stack, rela_stack_top); if (err) return err; err = rela_stack_push(opr1, rela_stack, rela_stack_top); if (err) return err; return 0; } static int apply_r_larch_sop_push_plt_pcrel(struct module *mod, Elf_Shdr *sechdrs, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { ptrdiff_t offset = (void *)v - (void *)location; if (offset >= SZ_128M) v = module_emit_plt_entry(mod, sechdrs, v); if (offset < -SZ_128M) v = module_emit_plt_entry(mod, sechdrs, v); return apply_r_larch_sop_push_pcrel(mod, location, v, rela_stack, rela_stack_top, type); } static int apply_r_larch_sop(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { int err = 0; s64 opr1, opr2, opr3; if (type == R_LARCH_SOP_IF_ELSE) { err = rela_stack_pop(&opr3, rela_stack, rela_stack_top); if (err) return err; } err = rela_stack_pop(&opr2, rela_stack, rela_stack_top); if (err) return err; err = rela_stack_pop(&opr1, rela_stack, rela_stack_top); if (err) return err; switch (type) { case R_LARCH_SOP_AND: err = rela_stack_push(opr1 & opr2, rela_stack, rela_stack_top); break; case R_LARCH_SOP_ADD: err = rela_stack_push(opr1 + opr2, rela_stack, rela_stack_top); break; case R_LARCH_SOP_SUB: err = rela_stack_push(opr1 - opr2, rela_stack, rela_stack_top); break; case R_LARCH_SOP_SL: err = rela_stack_push(opr1 << opr2, rela_stack, rela_stack_top); break; case R_LARCH_SOP_SR: err = rela_stack_push(opr1 >> opr2, rela_stack, rela_stack_top); break; case R_LARCH_SOP_IF_ELSE: err = rela_stack_push(opr1 ? opr2 : opr3, rela_stack, rela_stack_top); break; default: pr_err("%s: Unsupport relocation type %u\n", mod->name, type); return -EINVAL; } return err; } static int apply_r_larch_sop_imm_field(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { int err = 0; s64 opr1; union loongarch_instruction *insn = (union loongarch_instruction *)location; err = rela_stack_pop(&opr1, rela_stack, rela_stack_top); if (err) return err; switch (type) { case R_LARCH_SOP_POP_32_U_10_12: if (!unsigned_imm_check(opr1, 12)) goto overflow; /* (*(uint32_t *) PC) [21 ... 10] = opr [11 ... 0] */ insn->reg2i12_format.immediate = opr1 & 0xfff; return 0; case R_LARCH_SOP_POP_32_S_10_12: if (!signed_imm_check(opr1, 12)) goto overflow; insn->reg2i12_format.immediate = opr1 & 0xfff; return 0; case R_LARCH_SOP_POP_32_S_10_16: if (!signed_imm_check(opr1, 16)) goto overflow; insn->reg2i16_format.immediate = opr1 & 0xffff; return 0; case R_LARCH_SOP_POP_32_S_10_16_S2: if (opr1 % 4) goto unaligned; if (!signed_imm_check(opr1, 18)) goto overflow; insn->reg2i16_format.immediate = (opr1 >> 2) & 0xffff; return 0; case R_LARCH_SOP_POP_32_S_5_20: if (!signed_imm_check(opr1, 20)) goto overflow; insn->reg1i20_format.immediate = (opr1) & 0xfffff; return 0; case R_LARCH_SOP_POP_32_S_0_5_10_16_S2: if (opr1 % 4) goto unaligned; if (!signed_imm_check(opr1, 23)) goto overflow; opr1 >>= 2; insn->reg1i21_format.immediate_l = opr1 & 0xffff; insn->reg1i21_format.immediate_h = (opr1 >> 16) & 0x1f; return 0; case R_LARCH_SOP_POP_32_S_0_10_10_16_S2: if (opr1 % 4) goto unaligned; if (!signed_imm_check(opr1, 28)) goto overflow; opr1 >>= 2; insn->reg0i26_format.immediate_l = opr1 & 0xffff; insn->reg0i26_format.immediate_h = (opr1 >> 16) & 0x3ff; return 0; case R_LARCH_SOP_POP_32_U: if (!unsigned_imm_check(opr1, 32)) goto overflow; /* (*(uint32_t *) PC) = opr */ *location = (u32)opr1; return 0; default: pr_err("%s: Unsupport relocation type %u\n", mod->name, type); return -EINVAL; } overflow: pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s (%u) relocation\n", mod->name, opr1, __func__, type); return -ENOEXEC; unaligned: pr_err("module %s: opr1 = 0x%llx unaligned! dangerous %s (%u) relocation\n", mod->name, opr1, __func__, type); return -ENOEXEC; } static int apply_r_larch_add_sub(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { switch (type) { case R_LARCH_ADD32: *(s32 *)location += v; return 0; case R_LARCH_ADD64: *(s64 *)location += v; return 0; case R_LARCH_SUB32: *(s32 *)location -= v; return 0; case R_LARCH_SUB64: *(s64 *)location -= v; return 0; default: pr_err("%s: Unsupport relocation type %u\n", mod->name, type); return -EINVAL; } } static int apply_r_larch_b26(struct module *mod, Elf_Shdr *sechdrs, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { ptrdiff_t offset = (void *)v - (void *)location; union loongarch_instruction *insn = (union loongarch_instruction *)location; if (offset >= SZ_128M) v = module_emit_plt_entry(mod, sechdrs, v); if (offset < -SZ_128M) v = module_emit_plt_entry(mod, sechdrs, v); offset = (void *)v - (void *)location; if (offset & 3) { pr_err("module %s: jump offset = 0x%llx unaligned! dangerous R_LARCH_B26 (%u) relocation\n", mod->name, (long long)offset, type); return -ENOEXEC; } if (!signed_imm_check(offset, 28)) { pr_err("module %s: jump offset = 0x%llx overflow! dangerous R_LARCH_B26 (%u) relocation\n", mod->name, (long long)offset, type); return -ENOEXEC; } offset >>= 2; insn->reg0i26_format.immediate_l = offset & 0xffff; insn->reg0i26_format.immediate_h = (offset >> 16) & 0x3ff; return 0; } static int apply_r_larch_pcala(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { union loongarch_instruction *insn = (union loongarch_instruction *)location; /* Use s32 for a sign-extension deliberately. */ s32 offset_hi20 = (void *)((v + 0x800) & ~0xfff) - (void *)((Elf_Addr)location & ~0xfff); Elf_Addr anchor = (((Elf_Addr)location) & ~0xfff) + offset_hi20; ptrdiff_t offset_rem = (void *)v - (void *)anchor; switch (type) { case R_LARCH_PCALA_LO12: insn->reg2i12_format.immediate = v & 0xfff; break; case R_LARCH_PCALA_HI20: v = offset_hi20 >> 12; insn->reg1i20_format.immediate = v & 0xfffff; break; case R_LARCH_PCALA64_LO20: v = offset_rem >> 32; insn->reg1i20_format.immediate = v & 0xfffff; break; case R_LARCH_PCALA64_HI12: v = offset_rem >> 52; insn->reg2i12_format.immediate = v & 0xfff; break; default: pr_err("%s: Unsupport relocation type %u\n", mod->name, type); return -EINVAL; } return 0; } static int apply_r_larch_got_pc(struct module *mod, Elf_Shdr *sechdrs, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { Elf_Addr got = module_emit_got_entry(mod, sechdrs, v); if (!got) return -EINVAL; switch (type) { case R_LARCH_GOT_PC_LO12: type = R_LARCH_PCALA_LO12; break; case R_LARCH_GOT_PC_HI20: type = R_LARCH_PCALA_HI20; break; default: pr_err("%s: Unsupport relocation type %u\n", mod->name, type); return -EINVAL; } return apply_r_larch_pcala(mod, location, got, rela_stack, rela_stack_top, type); } static int apply_r_larch_32_pcrel(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { ptrdiff_t offset = (void *)v - (void *)location; *(u32 *)location = offset; return 0; } static int apply_r_larch_64_pcrel(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type) { ptrdiff_t offset = (void *)v - (void *)location; *(u64 *)location = offset; return 0; } /* * reloc_handlers_rela() - Apply a particular relocation to a module * @mod: the module to apply the reloc to * @location: the address at which the reloc is to be applied * @v: the value of the reloc, with addend for RELA-style * @rela_stack: the stack used for store relocation info, LOCAL to THIS module * @rela_stac_top: where the stack operation(pop/push) applies to * * Return: 0 upon success, else -ERRNO */ typedef int (*reloc_rela_handler)(struct module *mod, u32 *location, Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top, unsigned int type); /* The handlers for known reloc types */ static reloc_rela_handler reloc_rela_handlers[] = { [R_LARCH_NONE ... R_LARCH_64_PCREL] = apply_r_larch_error, [R_LARCH_NONE] = apply_r_larch_none, [R_LARCH_32] = apply_r_larch_32, [R_LARCH_64] = apply_r_larch_64, [R_LARCH_MARK_LA] = apply_r_larch_none, [R_LARCH_MARK_PCREL] = apply_r_larch_none, [R_LARCH_SOP_PUSH_PCREL] = apply_r_larch_sop_push_pcrel, [R_LARCH_SOP_PUSH_ABSOLUTE] = apply_r_larch_sop_push_absolute, [R_LARCH_SOP_PUSH_DUP] = apply_r_larch_sop_push_dup, [R_LARCH_SOP_SUB ... R_LARCH_SOP_IF_ELSE] = apply_r_larch_sop, [R_LARCH_SOP_POP_32_S_10_5 ... R_LARCH_SOP_POP_32_U] = apply_r_larch_sop_imm_field, [R_LARCH_ADD32 ... R_LARCH_SUB64] = apply_r_larch_add_sub, [R_LARCH_PCALA_HI20...R_LARCH_PCALA64_HI12] = apply_r_larch_pcala, [R_LARCH_32_PCREL] = apply_r_larch_32_pcrel, [R_LARCH_64_PCREL] = apply_r_larch_64_pcrel, }; int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *mod) { int i, err; unsigned int type; s64 rela_stack[RELA_STACK_DEPTH]; size_t rela_stack_top = 0; reloc_rela_handler handler; void *location; Elf_Addr v; Elf_Sym *sym; Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr; pr_debug("%s: Applying relocate section %u to %u\n", __func__, relsec, sechdrs[relsec].sh_info); rela_stack_top = 0; for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { /* This is where to make the change */ location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + rel[i].r_offset; /* This is the symbol it is referring to */ sym = (Elf_Sym *)sechdrs[symindex].sh_addr + ELF_R_SYM(rel[i].r_info); if (IS_ERR_VALUE(sym->st_value)) { /* Ignore unresolved weak symbol */ if (ELF_ST_BIND(sym->st_info) == STB_WEAK) continue; pr_warn("%s: Unknown symbol %s\n", mod->name, strtab + sym->st_name); return -ENOENT; } type = ELF_R_TYPE(rel[i].r_info); if (type < ARRAY_SIZE(reloc_rela_handlers)) handler = reloc_rela_handlers[type]; else handler = NULL; if (!handler) { pr_err("%s: Unknown relocation type %u\n", mod->name, type); return -EINVAL; } pr_debug("type %d st_value %llx r_addend %llx loc %llx\n", (int)ELF_R_TYPE(rel[i].r_info), sym->st_value, rel[i].r_addend, (u64)location); v = sym->st_value + rel[i].r_addend; switch (type) { case R_LARCH_B26: err = apply_r_larch_b26(mod, sechdrs, location, v, rela_stack, &rela_stack_top, type); break; case R_LARCH_GOT_PC_HI20...R_LARCH_GOT_PC_LO12: err = apply_r_larch_got_pc(mod, sechdrs, location, v, rela_stack, &rela_stack_top, type); break; case R_LARCH_SOP_PUSH_PLT_PCREL: err = apply_r_larch_sop_push_plt_pcrel(mod, sechdrs, location, v, rela_stack, &rela_stack_top, type); break; default: err = handler(mod, location, v, rela_stack, &rela_stack_top, type); } if (err) return err; } return 0; } void *module_alloc(unsigned long size) { return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE, __builtin_return_address(0)); } static void module_init_ftrace_plt(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mod) { #ifdef CONFIG_DYNAMIC_FTRACE struct plt_entry *ftrace_plts; ftrace_plts = (void *)sechdrs->sh_addr; ftrace_plts[FTRACE_PLT_IDX] = emit_plt_entry(FTRACE_ADDR); if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS)) ftrace_plts[FTRACE_REGS_PLT_IDX] = emit_plt_entry(FTRACE_REGS_ADDR); mod->arch.ftrace_trampolines = ftrace_plts; #endif } int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mod) { const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; const Elf_Shdr *s, *alt = NULL, *orc = NULL, *orc_ip = NULL, *ftrace = NULL; for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { if (!strcmp(".altinstructions", secstrs + s->sh_name)) alt = s; if (!strcmp(".orc_unwind", secstrs + s->sh_name)) orc = s; if (!strcmp(".orc_unwind_ip", secstrs + s->sh_name)) orc_ip = s; if (!strcmp(".ftrace_trampoline", secstrs + s->sh_name)) ftrace = s; } if (alt) apply_alternatives((void *)alt->sh_addr, (void *)alt->sh_addr + alt->sh_size); if (orc && orc_ip) unwind_module_init(mod, (void *)orc_ip->sh_addr, orc_ip->sh_size, (void *)orc->sh_addr, orc->sh_size); if (ftrace) module_init_ftrace_plt(hdr, ftrace, mod); return 0; } |