1 /*- 2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> 3 * Copyright (c) 1998 Peter Wemm <peter@freebsd.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/param.h> 32 #include <sys/endian.h> 33 #include <sys/exec.h> 34 #include <sys/linker.h> 35 #include <sys/module.h> 36 #include <sys/stdint.h> 37 #include <string.h> 38 #include <machine/elf.h> 39 #include <stand.h> 40 #define FREEBSD_ELF 41 #include <sys/link_elf.h> 42 43 #include "bootstrap.h" 44 45 #define COPYOUT(s,d,l) archsw.arch_copyout((vm_offset_t)(s), d, l) 46 47 #if defined(__i386__) && __ELF_WORD_SIZE == 64 48 #undef ELF_TARG_CLASS 49 #undef ELF_TARG_MACH 50 #define ELF_TARG_CLASS ELFCLASS64 51 #define ELF_TARG_MACH EM_X86_64 52 #endif 53 54 typedef struct elf_file { 55 Elf_Phdr *ph; 56 Elf_Ehdr *ehdr; 57 Elf_Sym *symtab; 58 Elf_Hashelt *hashtab; 59 Elf_Hashelt nbuckets; 60 Elf_Hashelt nchains; 61 Elf_Hashelt *buckets; 62 Elf_Hashelt *chains; 63 Elf_Rel *rel; 64 size_t relsz; 65 Elf_Rela *rela; 66 size_t relasz; 67 char *strtab; 68 size_t strsz; 69 int fd; 70 caddr_t firstpage; 71 size_t firstlen; 72 int kernel; 73 uint64_t off; 74 #ifdef LOADER_VERIEXEC_VECTX 75 struct vectx *vctx; 76 #endif 77 } *elf_file_t; 78 79 #ifdef LOADER_VERIEXEC_VECTX 80 #define VECTX_HANDLE(ef) (ef)->vctx 81 #else 82 #define VECTX_HANDLE(ef) (ef)->fd 83 #endif 84 85 static int __elfN(loadimage)(struct preloaded_file *mp, elf_file_t ef, 86 uint64_t loadaddr); 87 static int __elfN(lookup_symbol)(struct preloaded_file *mp, elf_file_t ef, 88 const char* name, Elf_Sym* sym); 89 static int __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, 90 Elf_Addr p, void *val, size_t len); 91 static int __elfN(parse_modmetadata)(struct preloaded_file *mp, elf_file_t ef, 92 Elf_Addr p_start, Elf_Addr p_end); 93 static symaddr_fn __elfN(symaddr); 94 static char *fake_modname(const char *name); 95 96 const char *__elfN(kerneltype) = "elf kernel"; 97 const char *__elfN(moduletype) = "elf module"; 98 99 uint64_t __elfN(relocation_offset) = 0; 100 101 extern void elf_wrong_field_size(void); 102 #define CONVERT_FIELD(b, f, e) \ 103 switch (sizeof((b)->f)) { \ 104 case 2: \ 105 (b)->f = e ## 16toh((b)->f); \ 106 break; \ 107 case 4: \ 108 (b)->f = e ## 32toh((b)->f); \ 109 break; \ 110 case 8: \ 111 (b)->f = e ## 64toh((b)->f); \ 112 break; \ 113 default: \ 114 /* Force a link time error. */ \ 115 elf_wrong_field_size(); \ 116 break; \ 117 } 118 119 #define CONVERT_SWITCH(h, d, f) \ 120 switch ((h)->e_ident[EI_DATA]) { \ 121 case ELFDATA2MSB: \ 122 f(d, be); \ 123 break; \ 124 case ELFDATA2LSB: \ 125 f(d, le); \ 126 break; \ 127 default: \ 128 return (EINVAL); \ 129 } 130 131 132 static int elf_header_convert(Elf_Ehdr *ehdr) 133 { 134 /* 135 * Fixup ELF header endianness. 136 * 137 * The Xhdr structure was loaded using block read call to optimize file 138 * accesses. It might happen, that the endianness of the system memory 139 * is different that endianness of the ELF header. Swap fields here to 140 * guarantee that Xhdr always contain valid data regardless of 141 * architecture. 142 */ 143 #define HEADER_FIELDS(b, e) \ 144 CONVERT_FIELD(b, e_type, e); \ 145 CONVERT_FIELD(b, e_machine, e); \ 146 CONVERT_FIELD(b, e_version, e); \ 147 CONVERT_FIELD(b, e_entry, e); \ 148 CONVERT_FIELD(b, e_phoff, e); \ 149 CONVERT_FIELD(b, e_shoff, e); \ 150 CONVERT_FIELD(b, e_flags, e); \ 151 CONVERT_FIELD(b, e_ehsize, e); \ 152 CONVERT_FIELD(b, e_phentsize, e); \ 153 CONVERT_FIELD(b, e_phnum, e); \ 154 CONVERT_FIELD(b, e_shentsize, e); \ 155 CONVERT_FIELD(b, e_shnum, e); \ 156 CONVERT_FIELD(b, e_shstrndx, e) 157 158 CONVERT_SWITCH(ehdr, ehdr, HEADER_FIELDS); 159 160 #undef HEADER_FIELDS 161 162 return (0); 163 } 164 165 static int elf_program_header_convert(const Elf_Ehdr *ehdr, Elf_Phdr *phdr) 166 { 167 #define PROGRAM_HEADER_FIELDS(b, e) \ 168 CONVERT_FIELD(b, p_type, e); \ 169 CONVERT_FIELD(b, p_flags, e); \ 170 CONVERT_FIELD(b, p_offset, e); \ 171 CONVERT_FIELD(b, p_vaddr, e); \ 172 CONVERT_FIELD(b, p_paddr, e); \ 173 CONVERT_FIELD(b, p_filesz, e); \ 174 CONVERT_FIELD(b, p_memsz, e); \ 175 CONVERT_FIELD(b, p_align, e) 176 177 CONVERT_SWITCH(ehdr, phdr, PROGRAM_HEADER_FIELDS); 178 179 #undef PROGRAM_HEADER_FIELDS 180 181 return (0); 182 } 183 184 static int elf_section_header_convert(const Elf_Ehdr *ehdr, Elf_Shdr *shdr) 185 { 186 #define SECTION_HEADER_FIELDS(b, e) \ 187 CONVERT_FIELD(b, sh_name, e); \ 188 CONVERT_FIELD(b, sh_type, e); \ 189 CONVERT_FIELD(b, sh_link, e); \ 190 CONVERT_FIELD(b, sh_info, e); \ 191 CONVERT_FIELD(b, sh_flags, e); \ 192 CONVERT_FIELD(b, sh_addr, e); \ 193 CONVERT_FIELD(b, sh_offset, e); \ 194 CONVERT_FIELD(b, sh_size, e); \ 195 CONVERT_FIELD(b, sh_addralign, e); \ 196 CONVERT_FIELD(b, sh_entsize, e) 197 198 CONVERT_SWITCH(ehdr, shdr, SECTION_HEADER_FIELDS); 199 200 #undef SECTION_HEADER_FIELDS 201 202 return (0); 203 } 204 #undef CONVERT_SWITCH 205 #undef CONVERT_FIELD 206 207 static int 208 __elfN(load_elf_header)(char *filename, elf_file_t ef) 209 { 210 ssize_t bytes_read; 211 Elf_Ehdr *ehdr; 212 int err; 213 214 /* 215 * Open the image, read and validate the ELF header 216 */ 217 if (filename == NULL) /* can't handle nameless */ 218 return (EFTYPE); 219 if ((ef->fd = open(filename, O_RDONLY)) == -1) 220 return (errno); 221 ef->firstpage = malloc(PAGE_SIZE); 222 if (ef->firstpage == NULL) { 223 close(ef->fd); 224 return (ENOMEM); 225 } 226 #ifdef LOADER_VERIEXEC_VECTX 227 { 228 int verror; 229 230 ef->vctx = vectx_open(ef->fd, filename, 0L, NULL, &verror, __func__); 231 if (verror) { 232 printf("Unverified %s: %s\n", filename, ve_error_get()); 233 close(ef->fd); 234 free(ef->vctx); 235 return (EAUTH); 236 } 237 } 238 #endif 239 bytes_read = VECTX_READ(VECTX_HANDLE(ef), ef->firstpage, PAGE_SIZE); 240 ef->firstlen = (size_t)bytes_read; 241 if (bytes_read < 0 || ef->firstlen <= sizeof(Elf_Ehdr)) { 242 err = EFTYPE; /* could be EIO, but may be small file */ 243 goto error; 244 } 245 ehdr = ef->ehdr = (Elf_Ehdr *)ef->firstpage; 246 247 /* Is it ELF? */ 248 if (!IS_ELF(*ehdr)) { 249 err = EFTYPE; 250 goto error; 251 } 252 253 if (ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || /* Layout ? */ 254 ehdr->e_ident[EI_DATA] != ELF_TARG_DATA || 255 ehdr->e_ident[EI_VERSION] != EV_CURRENT) /* Version ? */ { 256 err = EFTYPE; 257 goto error; 258 } 259 260 err = elf_header_convert(ehdr); 261 if (err) 262 goto error; 263 264 if (ehdr->e_version != EV_CURRENT || ehdr->e_machine != ELF_TARG_MACH) { 265 /* Machine ? */ 266 err = EFTYPE; 267 goto error; 268 } 269 270 #if defined(LOADER_VERIEXEC) && !defined(LOADER_VERIEXEC_VECTX) 271 if (verify_file(ef->fd, filename, bytes_read, VE_MUST, __func__) < 0) { 272 err = EAUTH; 273 goto error; 274 } 275 #endif 276 return (0); 277 278 error: 279 if (ef->firstpage != NULL) { 280 free(ef->firstpage); 281 ef->firstpage = NULL; 282 } 283 if (ef->fd != -1) { 284 #ifdef LOADER_VERIEXEC_VECTX 285 free(ef->vctx); 286 #endif 287 close(ef->fd); 288 ef->fd = -1; 289 } 290 return (err); 291 } 292 293 /* 294 * Attempt to load the file (file) as an ELF module. It will be stored at 295 * (dest), and a pointer to a module structure describing the loaded object 296 * will be saved in (result). 297 */ 298 int 299 __elfN(loadfile)(char *filename, uint64_t dest, struct preloaded_file **result) 300 { 301 return (__elfN(loadfile_raw)(filename, dest, result, 0)); 302 } 303 304 int 305 __elfN(loadfile_raw)(char *filename, uint64_t dest, 306 struct preloaded_file **result, int multiboot) 307 { 308 struct preloaded_file *fp, *kfp; 309 struct elf_file ef; 310 Elf_Ehdr *ehdr; 311 int err; 312 313 fp = NULL; 314 bzero(&ef, sizeof(struct elf_file)); 315 ef.fd = -1; 316 317 err = __elfN(load_elf_header)(filename, &ef); 318 if (err != 0) 319 return (err); 320 321 ehdr = ef.ehdr; 322 323 /* 324 * Check to see what sort of module we are. 325 */ 326 kfp = file_findfile(NULL, __elfN(kerneltype)); 327 #ifdef __powerpc__ 328 /* 329 * Kernels can be ET_DYN, so just assume the first loaded object is the 330 * kernel. This assumption will be checked later. 331 */ 332 if (kfp == NULL) 333 ef.kernel = 1; 334 #endif 335 if (ef.kernel || ehdr->e_type == ET_EXEC) { 336 /* Looks like a kernel */ 337 if (kfp != NULL) { 338 printf("elf" __XSTRING(__ELF_WORD_SIZE) 339 "_loadfile: kernel already loaded\n"); 340 err = EPERM; 341 goto oerr; 342 } 343 /* 344 * Calculate destination address based on kernel entrypoint. 345 * 346 * For ARM, the destination address is independent of any values 347 * in the elf header (an ARM kernel can be loaded at any 2MB 348 * boundary), so we leave dest set to the value calculated by 349 * archsw.arch_loadaddr() and passed in to this function. 350 */ 351 #ifndef __arm__ 352 if (ehdr->e_type == ET_EXEC) 353 dest = (ehdr->e_entry & ~PAGE_MASK); 354 #endif 355 if ((ehdr->e_entry & ~PAGE_MASK) == 0) { 356 printf("elf" __XSTRING(__ELF_WORD_SIZE) 357 "_loadfile: not a kernel (maybe static binary?)\n"); 358 err = EPERM; 359 goto oerr; 360 } 361 ef.kernel = 1; 362 363 } else if (ehdr->e_type == ET_DYN) { 364 /* Looks like a kld module */ 365 if (multiboot != 0) { 366 printf("elf" __XSTRING(__ELF_WORD_SIZE) 367 "_loadfile: can't load module as multiboot\n"); 368 err = EPERM; 369 goto oerr; 370 } 371 if (kfp == NULL) { 372 printf("elf" __XSTRING(__ELF_WORD_SIZE) 373 "_loadfile: can't load module before kernel\n"); 374 err = EPERM; 375 goto oerr; 376 } 377 if (strcmp(__elfN(kerneltype), kfp->f_type)) { 378 printf("elf" __XSTRING(__ELF_WORD_SIZE) 379 "_loadfile: can't load module with kernel type '%s'\n", 380 kfp->f_type); 381 err = EPERM; 382 goto oerr; 383 } 384 /* Looks OK, got ahead */ 385 ef.kernel = 0; 386 387 } else { 388 err = EFTYPE; 389 goto oerr; 390 } 391 392 if (archsw.arch_loadaddr != NULL) 393 dest = archsw.arch_loadaddr(LOAD_ELF, ehdr, dest); 394 else 395 dest = roundup(dest, PAGE_SIZE); 396 397 /* 398 * Ok, we think we should handle this. 399 */ 400 fp = file_alloc(); 401 if (fp == NULL) { 402 printf("elf" __XSTRING(__ELF_WORD_SIZE) 403 "_loadfile: cannot allocate module info\n"); 404 err = EPERM; 405 goto out; 406 } 407 if (ef.kernel == 1 && multiboot == 0) 408 setenv("kernelname", filename, 1); 409 fp->f_name = strdup(filename); 410 if (multiboot == 0) 411 fp->f_type = strdup(ef.kernel ? 412 __elfN(kerneltype) : __elfN(moduletype)); 413 else 414 fp->f_type = strdup("elf multiboot kernel"); 415 416 #ifdef ELF_VERBOSE 417 if (ef.kernel) 418 printf("%s entry at 0x%jx\n", filename, 419 (uintmax_t)ehdr->e_entry); 420 #else 421 printf("%s ", filename); 422 #endif 423 424 fp->f_size = __elfN(loadimage)(fp, &ef, dest); 425 if (fp->f_size == 0 || fp->f_addr == 0) 426 goto ioerr; 427 428 /* save exec header as metadata */ 429 file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*ehdr), ehdr); 430 431 /* Load OK, return module pointer */ 432 *result = (struct preloaded_file *)fp; 433 err = 0; 434 goto out; 435 436 ioerr: 437 err = EIO; 438 oerr: 439 file_discard(fp); 440 out: 441 if (ef.firstpage) 442 free(ef.firstpage); 443 if (ef.fd != -1) { 444 #ifdef LOADER_VERIEXEC_VECTX 445 if (!err && ef.vctx) { 446 int verror; 447 448 verror = vectx_close(ef.vctx, VE_MUST, __func__); 449 if (verror) { 450 err = EAUTH; 451 file_discard(fp); 452 } 453 } 454 #endif 455 close(ef.fd); 456 } 457 return (err); 458 } 459 460 /* 461 * With the file (fd) open on the image, and (ehdr) containing 462 * the Elf header, load the image at (off) 463 */ 464 static int 465 __elfN(loadimage)(struct preloaded_file *fp, elf_file_t ef, uint64_t off) 466 { 467 int i; 468 u_int j; 469 Elf_Ehdr *ehdr; 470 Elf_Phdr *phdr, *php; 471 Elf_Shdr *shdr; 472 char *shstr; 473 int ret; 474 vm_offset_t firstaddr; 475 vm_offset_t lastaddr; 476 size_t chunk; 477 ssize_t result; 478 Elf_Addr ssym, esym; 479 Elf_Dyn *dp; 480 Elf_Addr adp; 481 Elf_Addr ctors; 482 int ndp; 483 int symstrindex; 484 int symtabindex; 485 Elf_Size size; 486 u_int fpcopy; 487 Elf_Sym sym; 488 Elf_Addr p_start, p_end; 489 490 dp = NULL; 491 shdr = NULL; 492 ret = 0; 493 firstaddr = lastaddr = 0; 494 ehdr = ef->ehdr; 495 #ifdef __powerpc__ 496 if (ef->kernel) { 497 #else 498 if (ehdr->e_type == ET_EXEC) { 499 #endif 500 #if defined(__i386__) || defined(__amd64__) 501 #if __ELF_WORD_SIZE == 64 502 /* x86_64 relocates after locore */ 503 off = - (off & 0xffffffffff000000ull); 504 #else 505 /* i386 relocates after locore */ 506 off = - (off & 0xff000000u); 507 #endif 508 #elif defined(__powerpc__) 509 /* 510 * On the purely virtual memory machines like e500, the kernel 511 * is linked against its final VA range, which is most often 512 * not available at the loader stage, but only after kernel 513 * initializes and completes its VM settings. In such cases we 514 * cannot use p_vaddr field directly to load ELF segments, but 515 * put them at some 'load-time' locations. 516 */ 517 if (off & 0xf0000000u) { 518 off = -(off & 0xf0000000u); 519 /* 520 * XXX the physical load address should not be 521 * hardcoded. Note that the Book-E kernel assumes that 522 * it's loaded at a 16MB boundary for now... 523 */ 524 off += 0x01000000; 525 } 526 ehdr->e_entry += off; 527 #ifdef ELF_VERBOSE 528 printf("Converted entry 0x%jx\n", (uintmax_t)ehdr->e_entry); 529 #endif 530 #elif defined(__arm__) && !defined(EFI) 531 /* 532 * The elf headers in arm kernels specify virtual addresses in 533 * all header fields, even the ones that should be physical 534 * addresses. We assume the entry point is in the first page, 535 * and masking the page offset will leave us with the virtual 536 * address the kernel was linked at. We subtract that from the 537 * load offset, making 'off' into the value which, when added 538 * to a virtual address in an elf header, translates it to a 539 * physical address. We do the va->pa conversion on the entry 540 * point address in the header now, so that later we can launch 541 * the kernel by just jumping to that address. 542 * 543 * When booting from UEFI the copyin and copyout functions 544 * handle adjusting the location relative to the first virtual 545 * address. Because of this there is no need to adjust the 546 * offset or entry point address as these will both be handled 547 * by the efi code. 548 */ 549 off -= ehdr->e_entry & ~PAGE_MASK; 550 ehdr->e_entry += off; 551 #ifdef ELF_VERBOSE 552 printf("ehdr->e_entry 0x%jx, va<->pa off %llx\n", 553 (uintmax_t)ehdr->e_entry, off); 554 #endif 555 #else 556 off = 0; /* other archs use direct mapped kernels */ 557 #endif 558 } 559 ef->off = off; 560 561 if (ef->kernel) 562 __elfN(relocation_offset) = off; 563 564 if ((ehdr->e_phoff + ehdr->e_phnum * sizeof(*phdr)) > ef->firstlen) { 565 printf("elf" __XSTRING(__ELF_WORD_SIZE) 566 "_loadimage: program header not within first page\n"); 567 goto out; 568 } 569 phdr = (Elf_Phdr *)(ef->firstpage + ehdr->e_phoff); 570 571 for (i = 0; i < ehdr->e_phnum; i++) { 572 if (elf_program_header_convert(ehdr, phdr)) 573 continue; 574 575 /* We want to load PT_LOAD segments only.. */ 576 if (phdr[i].p_type != PT_LOAD) 577 continue; 578 579 #ifdef ELF_VERBOSE 580 printf("Segment: 0x%lx@0x%lx -> 0x%lx-0x%lx", 581 (long)phdr[i].p_filesz, (long)phdr[i].p_offset, 582 (long)(phdr[i].p_vaddr + off), 583 (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1)); 584 #else 585 if ((phdr[i].p_flags & PF_W) == 0) { 586 printf("text=0x%lx ", (long)phdr[i].p_filesz); 587 } else { 588 printf("data=0x%lx", (long)phdr[i].p_filesz); 589 if (phdr[i].p_filesz < phdr[i].p_memsz) 590 printf("+0x%lx", (long)(phdr[i].p_memsz - 591 phdr[i].p_filesz)); 592 printf(" "); 593 } 594 #endif 595 fpcopy = 0; 596 if (ef->firstlen > phdr[i].p_offset) { 597 fpcopy = ef->firstlen - phdr[i].p_offset; 598 archsw.arch_copyin(ef->firstpage + phdr[i].p_offset, 599 phdr[i].p_vaddr + off, fpcopy); 600 } 601 if (phdr[i].p_filesz > fpcopy) { 602 if (kern_pread(VECTX_HANDLE(ef), 603 phdr[i].p_vaddr + off + fpcopy, 604 phdr[i].p_filesz - fpcopy, 605 phdr[i].p_offset + fpcopy) != 0) { 606 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 607 "_loadimage: read failed\n"); 608 goto out; 609 } 610 } 611 /* clear space from oversized segments; eg: bss */ 612 if (phdr[i].p_filesz < phdr[i].p_memsz) { 613 #ifdef ELF_VERBOSE 614 printf(" (bss: 0x%lx-0x%lx)", 615 (long)(phdr[i].p_vaddr + off + phdr[i].p_filesz), 616 (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz -1)); 617 #endif 618 619 kern_bzero(phdr[i].p_vaddr + off + phdr[i].p_filesz, 620 phdr[i].p_memsz - phdr[i].p_filesz); 621 } 622 #ifdef ELF_VERBOSE 623 printf("\n"); 624 #endif 625 626 if (archsw.arch_loadseg != NULL) 627 archsw.arch_loadseg(ehdr, phdr + i, off); 628 629 if (firstaddr == 0 || firstaddr > (phdr[i].p_vaddr + off)) 630 firstaddr = phdr[i].p_vaddr + off; 631 if (lastaddr == 0 || lastaddr < 632 (phdr[i].p_vaddr + off + phdr[i].p_memsz)) 633 lastaddr = phdr[i].p_vaddr + off + phdr[i].p_memsz; 634 } 635 lastaddr = roundup(lastaddr, sizeof(long)); 636 637 /* 638 * Get the section headers. We need this for finding the .ctors 639 * section as well as for loading any symbols. Both may be hard 640 * to do if reading from a .gz file as it involves seeking. I 641 * think the rule is going to have to be that you must strip a 642 * file to remove symbols before gzipping it. 643 */ 644 chunk = (size_t)ehdr->e_shnum * (size_t)ehdr->e_shentsize; 645 if (chunk == 0 || ehdr->e_shoff == 0) 646 goto nosyms; 647 shdr = alloc_pread(VECTX_HANDLE(ef), ehdr->e_shoff, chunk); 648 if (shdr == NULL) { 649 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 650 "_loadimage: failed to read section headers"); 651 goto nosyms; 652 } 653 654 for (i = 0; i < ehdr->e_shnum; i++) 655 elf_section_header_convert(ehdr, &shdr[i]); 656 657 file_addmetadata(fp, MODINFOMD_SHDR, chunk, shdr); 658 659 /* 660 * Read the section string table and look for the .ctors section. 661 * We need to tell the kernel where it is so that it can call the 662 * ctors. 663 */ 664 chunk = shdr[ehdr->e_shstrndx].sh_size; 665 if (chunk) { 666 shstr = alloc_pread(VECTX_HANDLE(ef), 667 shdr[ehdr->e_shstrndx].sh_offset, chunk); 668 if (shstr) { 669 for (i = 0; i < ehdr->e_shnum; i++) { 670 if (strcmp(shstr + shdr[i].sh_name, 671 ".ctors") != 0) 672 continue; 673 ctors = shdr[i].sh_addr; 674 file_addmetadata(fp, MODINFOMD_CTORS_ADDR, 675 sizeof(ctors), &ctors); 676 size = shdr[i].sh_size; 677 file_addmetadata(fp, MODINFOMD_CTORS_SIZE, 678 sizeof(size), &size); 679 break; 680 } 681 free(shstr); 682 } 683 } 684 685 /* 686 * Now load any symbols. 687 */ 688 symtabindex = -1; 689 symstrindex = -1; 690 for (i = 0; i < ehdr->e_shnum; i++) { 691 if (shdr[i].sh_type != SHT_SYMTAB) 692 continue; 693 for (j = 0; j < ehdr->e_phnum; j++) { 694 if (phdr[j].p_type != PT_LOAD) 695 continue; 696 if (shdr[i].sh_offset >= phdr[j].p_offset && 697 (shdr[i].sh_offset + shdr[i].sh_size <= 698 phdr[j].p_offset + phdr[j].p_filesz)) { 699 shdr[i].sh_offset = 0; 700 shdr[i].sh_size = 0; 701 break; 702 } 703 } 704 if (shdr[i].sh_offset == 0 || shdr[i].sh_size == 0) 705 continue; /* alread loaded in a PT_LOAD above */ 706 /* Save it for loading below */ 707 symtabindex = i; 708 symstrindex = shdr[i].sh_link; 709 } 710 if (symtabindex < 0 || symstrindex < 0) 711 goto nosyms; 712 713 /* Ok, committed to a load. */ 714 #ifndef ELF_VERBOSE 715 printf("syms=["); 716 #endif 717 ssym = lastaddr; 718 for (i = symtabindex; i >= 0; i = symstrindex) { 719 #ifdef ELF_VERBOSE 720 char *secname; 721 722 switch(shdr[i].sh_type) { 723 case SHT_SYMTAB: /* Symbol table */ 724 secname = "symtab"; 725 break; 726 case SHT_STRTAB: /* String table */ 727 secname = "strtab"; 728 break; 729 default: 730 secname = "WHOA!!"; 731 break; 732 } 733 #endif 734 size = shdr[i].sh_size; 735 #if defined(__powerpc__) 736 #if __ELF_WORD_SIZE == 64 737 size = htobe64(size); 738 #else 739 size = htobe32(size); 740 #endif 741 #endif 742 743 archsw.arch_copyin(&size, lastaddr, sizeof(size)); 744 lastaddr += sizeof(size); 745 746 #ifdef ELF_VERBOSE 747 printf("\n%s: 0x%jx@0x%jx -> 0x%jx-0x%jx", secname, 748 (uintmax_t)shdr[i].sh_size, (uintmax_t)shdr[i].sh_offset, 749 (uintmax_t)lastaddr, 750 (uintmax_t)(lastaddr + shdr[i].sh_size)); 751 #else 752 if (i == symstrindex) 753 printf("+"); 754 printf("0x%lx+0x%lx", (long)sizeof(size), (long)size); 755 #endif 756 757 if (VECTX_LSEEK(VECTX_HANDLE(ef), (off_t)shdr[i].sh_offset, SEEK_SET) == -1) { 758 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 759 "_loadimage: could not seek for symbols - skipped!"); 760 lastaddr = ssym; 761 ssym = 0; 762 goto nosyms; 763 } 764 result = archsw.arch_readin(VECTX_HANDLE(ef), lastaddr, shdr[i].sh_size); 765 if (result < 0 || (size_t)result != shdr[i].sh_size) { 766 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 767 "_loadimage: could not read symbols - skipped! " 768 "(%ju != %ju)", (uintmax_t)result, 769 (uintmax_t)shdr[i].sh_size); 770 lastaddr = ssym; 771 ssym = 0; 772 goto nosyms; 773 } 774 /* Reset offsets relative to ssym */ 775 lastaddr += shdr[i].sh_size; 776 lastaddr = roundup(lastaddr, sizeof(size)); 777 if (i == symtabindex) 778 symtabindex = -1; 779 else if (i == symstrindex) 780 symstrindex = -1; 781 } 782 esym = lastaddr; 783 #ifndef ELF_VERBOSE 784 printf("]"); 785 #endif 786 787 #if defined(__powerpc__) 788 /* On PowerPC we always need to provide BE data to the kernel */ 789 #if __ELF_WORD_SIZE == 64 790 ssym = htobe64((uint64_t)ssym); 791 esym = htobe64((uint64_t)esym); 792 #else 793 ssym = htobe32((uint32_t)ssym); 794 esym = htobe32((uint32_t)esym); 795 #endif 796 #endif 797 798 file_addmetadata(fp, MODINFOMD_SSYM, sizeof(ssym), &ssym); 799 file_addmetadata(fp, MODINFOMD_ESYM, sizeof(esym), &esym); 800 801 nosyms: 802 printf("\n"); 803 804 ret = lastaddr - firstaddr; 805 fp->f_addr = firstaddr; 806 807 php = NULL; 808 for (i = 0; i < ehdr->e_phnum; i++) { 809 if (phdr[i].p_type == PT_DYNAMIC) { 810 php = phdr + i; 811 adp = php->p_vaddr; 812 file_addmetadata(fp, MODINFOMD_DYNAMIC, sizeof(adp), 813 &adp); 814 break; 815 } 816 } 817 818 if (php == NULL) /* this is bad, we cannot get to symbols or _DYNAMIC */ 819 goto out; 820 821 ndp = php->p_filesz / sizeof(Elf_Dyn); 822 if (ndp == 0) 823 goto out; 824 dp = malloc(php->p_filesz); 825 if (dp == NULL) 826 goto out; 827 archsw.arch_copyout(php->p_vaddr + off, dp, php->p_filesz); 828 829 ef->strsz = 0; 830 for (i = 0; i < ndp; i++) { 831 if (dp[i].d_tag == 0) 832 break; 833 switch (dp[i].d_tag) { 834 case DT_HASH: 835 ef->hashtab = 836 (Elf_Hashelt*)(uintptr_t)(dp[i].d_un.d_ptr + off); 837 break; 838 case DT_STRTAB: 839 ef->strtab = 840 (char *)(uintptr_t)(dp[i].d_un.d_ptr + off); 841 break; 842 case DT_STRSZ: 843 ef->strsz = dp[i].d_un.d_val; 844 break; 845 case DT_SYMTAB: 846 ef->symtab = 847 (Elf_Sym *)(uintptr_t)(dp[i].d_un.d_ptr + off); 848 break; 849 case DT_REL: 850 ef->rel = 851 (Elf_Rel *)(uintptr_t)(dp[i].d_un.d_ptr + off); 852 break; 853 case DT_RELSZ: 854 ef->relsz = dp[i].d_un.d_val; 855 break; 856 case DT_RELA: 857 ef->rela = 858 (Elf_Rela *)(uintptr_t)(dp[i].d_un.d_ptr + off); 859 break; 860 case DT_RELASZ: 861 ef->relasz = dp[i].d_un.d_val; 862 break; 863 default: 864 break; 865 } 866 } 867 if (ef->hashtab == NULL || ef->symtab == NULL || 868 ef->strtab == NULL || ef->strsz == 0) 869 goto out; 870 COPYOUT(ef->hashtab, &ef->nbuckets, sizeof(ef->nbuckets)); 871 COPYOUT(ef->hashtab + 1, &ef->nchains, sizeof(ef->nchains)); 872 ef->buckets = ef->hashtab + 2; 873 ef->chains = ef->buckets + ef->nbuckets; 874 875 if (__elfN(lookup_symbol)(fp, ef, "__start_set_modmetadata_set", 876 &sym) != 0) 877 return 0; 878 p_start = sym.st_value + ef->off; 879 if (__elfN(lookup_symbol)(fp, ef, "__stop_set_modmetadata_set", 880 &sym) != 0) 881 return ENOENT; 882 p_end = sym.st_value + ef->off; 883 884 if (__elfN(parse_modmetadata)(fp, ef, p_start, p_end) == 0) 885 goto out; 886 887 if (ef->kernel) /* kernel must not depend on anything */ 888 goto out; 889 890 out: 891 if (dp) 892 free(dp); 893 if (shdr) 894 free(shdr); 895 return ret; 896 } 897 898 static char invalid_name[] = "bad"; 899 900 char * 901 fake_modname(const char *name) 902 { 903 const char *sp, *ep; 904 char *fp; 905 size_t len; 906 907 sp = strrchr(name, '/'); 908 if (sp) 909 sp++; 910 else 911 sp = name; 912 913 ep = strrchr(sp, '.'); 914 if (ep == NULL) { 915 ep = sp + strlen(sp); 916 } 917 if (ep == sp) { 918 sp = invalid_name; 919 ep = invalid_name + sizeof(invalid_name) - 1; 920 } 921 922 len = ep - sp; 923 fp = malloc(len + 1); 924 if (fp == NULL) 925 return NULL; 926 memcpy(fp, sp, len); 927 fp[len] = '\0'; 928 return fp; 929 } 930 931 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64 932 struct mod_metadata64 { 933 int md_version; /* structure version MDTV_* */ 934 int md_type; /* type of entry MDT_* */ 935 uint64_t md_data; /* specific data */ 936 uint64_t md_cval; /* common string label */ 937 }; 938 #endif 939 #if defined(__amd64__) && __ELF_WORD_SIZE == 32 940 struct mod_metadata32 { 941 int md_version; /* structure version MDTV_* */ 942 int md_type; /* type of entry MDT_* */ 943 uint32_t md_data; /* specific data */ 944 uint32_t md_cval; /* common string label */ 945 }; 946 #endif 947 948 int 949 __elfN(load_modmetadata)(struct preloaded_file *fp, uint64_t dest) 950 { 951 struct elf_file ef; 952 int err, i, j; 953 Elf_Shdr *sh_meta, *shdr = NULL; 954 Elf_Shdr *sh_data[2]; 955 char *shstrtab = NULL; 956 size_t size; 957 Elf_Addr p_start, p_end; 958 959 bzero(&ef, sizeof(struct elf_file)); 960 ef.fd = -1; 961 962 err = __elfN(load_elf_header)(fp->f_name, &ef); 963 if (err != 0) 964 goto out; 965 966 if (ef.kernel == 1 || ef.ehdr->e_type == ET_EXEC) { 967 ef.kernel = 1; 968 } else if (ef.ehdr->e_type != ET_DYN) { 969 err = EFTYPE; 970 goto out; 971 } 972 973 size = (size_t)ef.ehdr->e_shnum * (size_t)ef.ehdr->e_shentsize; 974 shdr = alloc_pread(VECTX_HANDLE(&ef), ef.ehdr->e_shoff, size); 975 if (shdr == NULL) { 976 err = ENOMEM; 977 goto out; 978 } 979 980 /* Load shstrtab. */ 981 shstrtab = alloc_pread(VECTX_HANDLE(&ef), shdr[ef.ehdr->e_shstrndx].sh_offset, 982 shdr[ef.ehdr->e_shstrndx].sh_size); 983 if (shstrtab == NULL) { 984 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 985 "load_modmetadata: unable to load shstrtab\n"); 986 err = EFTYPE; 987 goto out; 988 } 989 990 /* Find set_modmetadata_set and data sections. */ 991 sh_data[0] = sh_data[1] = sh_meta = NULL; 992 for (i = 0, j = 0; i < ef.ehdr->e_shnum; i++) { 993 if (strcmp(&shstrtab[shdr[i].sh_name], 994 "set_modmetadata_set") == 0) { 995 sh_meta = &shdr[i]; 996 } 997 if ((strcmp(&shstrtab[shdr[i].sh_name], ".data") == 0) || 998 (strcmp(&shstrtab[shdr[i].sh_name], ".rodata") == 0)) { 999 sh_data[j++] = &shdr[i]; 1000 } 1001 } 1002 if (sh_meta == NULL || sh_data[0] == NULL || sh_data[1] == NULL) { 1003 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 1004 "load_modmetadata: unable to find set_modmetadata_set or data sections\n"); 1005 err = EFTYPE; 1006 goto out; 1007 } 1008 1009 /* Load set_modmetadata_set into memory */ 1010 err = kern_pread(VECTX_HANDLE(&ef), dest, sh_meta->sh_size, sh_meta->sh_offset); 1011 if (err != 0) { 1012 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 1013 "load_modmetadata: unable to load set_modmetadata_set: %d\n", err); 1014 goto out; 1015 } 1016 p_start = dest; 1017 p_end = dest + sh_meta->sh_size; 1018 dest += sh_meta->sh_size; 1019 1020 /* Load data sections into memory. */ 1021 err = kern_pread(VECTX_HANDLE(&ef), dest, sh_data[0]->sh_size, 1022 sh_data[0]->sh_offset); 1023 if (err != 0) { 1024 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 1025 "load_modmetadata: unable to load data: %d\n", err); 1026 goto out; 1027 } 1028 1029 /* 1030 * We have to increment the dest, so that the offset is the same into 1031 * both the .rodata and .data sections. 1032 */ 1033 ef.off = -(sh_data[0]->sh_addr - dest); 1034 dest += (sh_data[1]->sh_addr - sh_data[0]->sh_addr); 1035 1036 err = kern_pread(VECTX_HANDLE(&ef), dest, sh_data[1]->sh_size, 1037 sh_data[1]->sh_offset); 1038 if (err != 0) { 1039 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 1040 "load_modmetadata: unable to load data: %d\n", err); 1041 goto out; 1042 } 1043 1044 err = __elfN(parse_modmetadata)(fp, &ef, p_start, p_end); 1045 if (err != 0) { 1046 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 1047 "load_modmetadata: unable to parse metadata: %d\n", err); 1048 goto out; 1049 } 1050 1051 out: 1052 if (shstrtab != NULL) 1053 free(shstrtab); 1054 if (shdr != NULL) 1055 free(shdr); 1056 if (ef.firstpage != NULL) 1057 free(ef.firstpage); 1058 if (ef.fd != -1) { 1059 #ifdef LOADER_VERIEXEC_VECTX 1060 if (!err && ef.vctx) { 1061 int verror; 1062 1063 verror = vectx_close(ef.vctx, VE_MUST, __func__); 1064 if (verror) { 1065 err = EAUTH; 1066 file_discard(fp); 1067 } 1068 } 1069 #endif 1070 close(ef.fd); 1071 } 1072 return (err); 1073 } 1074 1075 int 1076 __elfN(parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef, 1077 Elf_Addr p_start, Elf_Addr p_end) 1078 { 1079 struct mod_metadata md; 1080 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64 1081 struct mod_metadata64 md64; 1082 #elif defined(__amd64__) && __ELF_WORD_SIZE == 32 1083 struct mod_metadata32 md32; 1084 #endif 1085 struct mod_depend *mdepend; 1086 struct mod_version mver; 1087 char *s; 1088 int error, modcnt, minfolen; 1089 Elf_Addr v, p; 1090 1091 modcnt = 0; 1092 p = p_start; 1093 while (p < p_end) { 1094 COPYOUT(p, &v, sizeof(v)); 1095 error = __elfN(reloc_ptr)(fp, ef, p, &v, sizeof(v)); 1096 if (error == EOPNOTSUPP) 1097 v += ef->off; 1098 else if (error != 0) 1099 return (error); 1100 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64 1101 COPYOUT(v, &md64, sizeof(md64)); 1102 error = __elfN(reloc_ptr)(fp, ef, v, &md64, sizeof(md64)); 1103 if (error == EOPNOTSUPP) { 1104 md64.md_cval += ef->off; 1105 md64.md_data += ef->off; 1106 } else if (error != 0) 1107 return (error); 1108 md.md_version = md64.md_version; 1109 md.md_type = md64.md_type; 1110 md.md_cval = (const char *)(uintptr_t)md64.md_cval; 1111 md.md_data = (void *)(uintptr_t)md64.md_data; 1112 #elif defined(__amd64__) && __ELF_WORD_SIZE == 32 1113 COPYOUT(v, &md32, sizeof(md32)); 1114 error = __elfN(reloc_ptr)(fp, ef, v, &md32, sizeof(md32)); 1115 if (error == EOPNOTSUPP) { 1116 md32.md_cval += ef->off; 1117 md32.md_data += ef->off; 1118 } else if (error != 0) 1119 return (error); 1120 md.md_version = md32.md_version; 1121 md.md_type = md32.md_type; 1122 md.md_cval = (const char *)(uintptr_t)md32.md_cval; 1123 md.md_data = (void *)(uintptr_t)md32.md_data; 1124 #else 1125 COPYOUT(v, &md, sizeof(md)); 1126 error = __elfN(reloc_ptr)(fp, ef, v, &md, sizeof(md)); 1127 if (error == EOPNOTSUPP) { 1128 md.md_cval += ef->off; 1129 md.md_data = (void *)((uintptr_t)md.md_data + 1130 (uintptr_t)ef->off); 1131 } else if (error != 0) 1132 return (error); 1133 #endif 1134 p += sizeof(Elf_Addr); 1135 switch(md.md_type) { 1136 case MDT_DEPEND: 1137 if (ef->kernel) /* kernel must not depend on anything */ 1138 break; 1139 s = strdupout((vm_offset_t)md.md_cval); 1140 minfolen = sizeof(*mdepend) + strlen(s) + 1; 1141 mdepend = malloc(minfolen); 1142 if (mdepend == NULL) 1143 return ENOMEM; 1144 COPYOUT((vm_offset_t)md.md_data, mdepend, 1145 sizeof(*mdepend)); 1146 strcpy((char*)(mdepend + 1), s); 1147 free(s); 1148 file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen, 1149 mdepend); 1150 free(mdepend); 1151 break; 1152 case MDT_VERSION: 1153 s = strdupout((vm_offset_t)md.md_cval); 1154 COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver)); 1155 file_addmodule(fp, s, mver.mv_version, NULL); 1156 free(s); 1157 modcnt++; 1158 break; 1159 } 1160 } 1161 if (modcnt == 0) { 1162 s = fake_modname(fp->f_name); 1163 file_addmodule(fp, s, 1, NULL); 1164 free(s); 1165 } 1166 return 0; 1167 } 1168 1169 static unsigned long 1170 elf_hash(const char *name) 1171 { 1172 const unsigned char *p = (const unsigned char *) name; 1173 unsigned long h = 0; 1174 unsigned long g; 1175 1176 while (*p != '\0') { 1177 h = (h << 4) + *p++; 1178 if ((g = h & 0xf0000000) != 0) 1179 h ^= g >> 24; 1180 h &= ~g; 1181 } 1182 return h; 1183 } 1184 1185 static const char __elfN(bad_symtable)[] = "elf" __XSTRING(__ELF_WORD_SIZE) 1186 "_lookup_symbol: corrupt symbol table\n"; 1187 int 1188 __elfN(lookup_symbol)(struct preloaded_file *fp, elf_file_t ef, 1189 const char* name, Elf_Sym *symp) 1190 { 1191 Elf_Hashelt symnum; 1192 Elf_Sym sym; 1193 char *strp; 1194 unsigned long hash; 1195 1196 hash = elf_hash(name); 1197 COPYOUT(&ef->buckets[hash % ef->nbuckets], &symnum, sizeof(symnum)); 1198 1199 while (symnum != STN_UNDEF) { 1200 if (symnum >= ef->nchains) { 1201 printf(__elfN(bad_symtable)); 1202 return ENOENT; 1203 } 1204 1205 COPYOUT(ef->symtab + symnum, &sym, sizeof(sym)); 1206 if (sym.st_name == 0) { 1207 printf(__elfN(bad_symtable)); 1208 return ENOENT; 1209 } 1210 1211 strp = strdupout((vm_offset_t)(ef->strtab + sym.st_name)); 1212 if (strcmp(name, strp) == 0) { 1213 free(strp); 1214 if (sym.st_shndx != SHN_UNDEF || 1215 (sym.st_value != 0 && 1216 ELF_ST_TYPE(sym.st_info) == STT_FUNC)) { 1217 *symp = sym; 1218 return 0; 1219 } 1220 return ENOENT; 1221 } 1222 free(strp); 1223 COPYOUT(&ef->chains[symnum], &symnum, sizeof(symnum)); 1224 } 1225 return ENOENT; 1226 } 1227 1228 /* 1229 * Apply any intra-module relocations to the value. p is the load address 1230 * of the value and val/len is the value to be modified. This does NOT modify 1231 * the image in-place, because this is done by kern_linker later on. 1232 * 1233 * Returns EOPNOTSUPP if no relocation method is supplied. 1234 */ 1235 static int 1236 __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, 1237 Elf_Addr p, void *val, size_t len) 1238 { 1239 size_t n; 1240 Elf_Rela a; 1241 Elf_Rel r; 1242 int error; 1243 1244 /* 1245 * The kernel is already relocated, but we still want to apply 1246 * offset adjustments. 1247 */ 1248 if (ef->kernel) 1249 return (EOPNOTSUPP); 1250 1251 for (n = 0; n < ef->relsz / sizeof(r); n++) { 1252 COPYOUT(ef->rel + n, &r, sizeof(r)); 1253 1254 error = __elfN(reloc)(ef, __elfN(symaddr), &r, ELF_RELOC_REL, 1255 ef->off, p, val, len); 1256 if (error != 0) 1257 return (error); 1258 } 1259 for (n = 0; n < ef->relasz / sizeof(a); n++) { 1260 COPYOUT(ef->rela + n, &a, sizeof(a)); 1261 1262 error = __elfN(reloc)(ef, __elfN(symaddr), &a, ELF_RELOC_RELA, 1263 ef->off, p, val, len); 1264 if (error != 0) 1265 return (error); 1266 } 1267 1268 return (0); 1269 } 1270 1271 static Elf_Addr 1272 __elfN(symaddr)(struct elf_file *ef, Elf_Size symidx) 1273 { 1274 1275 /* Symbol lookup by index not required here. */ 1276 return (0); 1277 } 1278