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 u_int64_t off; 74 } *elf_file_t; 75 76 static int __elfN(loadimage)(struct preloaded_file *mp, elf_file_t ef, u_int64_t loadaddr); 77 static int __elfN(lookup_symbol)(struct preloaded_file *mp, elf_file_t ef, const char* name, Elf_Sym* sym); 78 static int __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, 79 Elf_Addr p, void *val, size_t len); 80 static int __elfN(parse_modmetadata)(struct preloaded_file *mp, elf_file_t ef, 81 Elf_Addr p_start, Elf_Addr p_end); 82 static symaddr_fn __elfN(symaddr); 83 static char *fake_modname(const char *name); 84 85 const char *__elfN(kerneltype) = "elf kernel"; 86 const char *__elfN(moduletype) = "elf module"; 87 88 u_int64_t __elfN(relocation_offset) = 0; 89 90 extern void elf_wrong_field_size(void); 91 #define CONVERT_FIELD(b, f, e) \ 92 switch (sizeof((b)->f)) { \ 93 case 2: \ 94 (b)->f = e ## 16toh((b)->f); \ 95 break; \ 96 case 4: \ 97 (b)->f = e ## 32toh((b)->f); \ 98 break; \ 99 case 8: \ 100 (b)->f = e ## 64toh((b)->f); \ 101 break; \ 102 default: \ 103 /* Force a link time error. */ \ 104 elf_wrong_field_size(); \ 105 break; \ 106 } 107 108 #define CONVERT_SWITCH(h, d, f) \ 109 switch ((h)->e_ident[EI_DATA]) { \ 110 case ELFDATA2MSB: \ 111 f(d, be); \ 112 break; \ 113 case ELFDATA2LSB: \ 114 f(d, le); \ 115 break; \ 116 default: \ 117 return (EINVAL); \ 118 } 119 120 121 static int elf_header_convert(Elf_Ehdr *ehdr) 122 { 123 /* 124 * Fixup ELF header endianness. 125 * 126 * The Xhdr structure was loaded using block read call to optimize file 127 * accesses. It might happen, that the endianness of the system memory 128 * is different that endianness of the ELF header. Swap fields here to 129 * guarantee that Xhdr always contain valid data regardless of 130 * architecture. 131 */ 132 #define HEADER_FIELDS(b, e) \ 133 CONVERT_FIELD(b, e_type, e); \ 134 CONVERT_FIELD(b, e_machine, e); \ 135 CONVERT_FIELD(b, e_version, e); \ 136 CONVERT_FIELD(b, e_entry, e); \ 137 CONVERT_FIELD(b, e_phoff, e); \ 138 CONVERT_FIELD(b, e_shoff, e); \ 139 CONVERT_FIELD(b, e_flags, e); \ 140 CONVERT_FIELD(b, e_ehsize, e); \ 141 CONVERT_FIELD(b, e_phentsize, e); \ 142 CONVERT_FIELD(b, e_phnum, e); \ 143 CONVERT_FIELD(b, e_shentsize, e); \ 144 CONVERT_FIELD(b, e_shnum, e); \ 145 CONVERT_FIELD(b, e_shstrndx, e) 146 147 CONVERT_SWITCH(ehdr, ehdr, HEADER_FIELDS); 148 149 #undef HEADER_FIELDS 150 151 return (0); 152 } 153 154 static int elf_program_header_convert(const Elf_Ehdr *ehdr, Elf_Phdr *phdr) 155 { 156 #define PROGRAM_HEADER_FIELDS(b, e) \ 157 CONVERT_FIELD(b, p_type, e); \ 158 CONVERT_FIELD(b, p_flags, e); \ 159 CONVERT_FIELD(b, p_offset, e); \ 160 CONVERT_FIELD(b, p_vaddr, e); \ 161 CONVERT_FIELD(b, p_paddr, e); \ 162 CONVERT_FIELD(b, p_filesz, e); \ 163 CONVERT_FIELD(b, p_memsz, e); \ 164 CONVERT_FIELD(b, p_align, e) 165 166 CONVERT_SWITCH(ehdr, phdr, PROGRAM_HEADER_FIELDS); 167 168 #undef PROGRAM_HEADER_FIELDS 169 170 return (0); 171 } 172 173 static int elf_section_header_convert(const Elf_Ehdr *ehdr, Elf_Shdr *shdr) 174 { 175 #define SECTION_HEADER_FIELDS(b, e) \ 176 CONVERT_FIELD(b, sh_name, e); \ 177 CONVERT_FIELD(b, sh_type, e); \ 178 CONVERT_FIELD(b, sh_link, e); \ 179 CONVERT_FIELD(b, sh_info, e); \ 180 CONVERT_FIELD(b, sh_flags, e); \ 181 CONVERT_FIELD(b, sh_addr, e); \ 182 CONVERT_FIELD(b, sh_offset, e); \ 183 CONVERT_FIELD(b, sh_size, e); \ 184 CONVERT_FIELD(b, sh_addralign, e); \ 185 CONVERT_FIELD(b, sh_entsize, e) 186 187 CONVERT_SWITCH(ehdr, shdr, SECTION_HEADER_FIELDS); 188 189 #undef SECTION_HEADER_FIELDS 190 191 return (0); 192 } 193 #undef CONVERT_SWITCH 194 #undef CONVERT_FIELD 195 196 static int 197 __elfN(load_elf_header)(char *filename, elf_file_t ef) 198 { 199 ssize_t bytes_read; 200 Elf_Ehdr *ehdr; 201 int err; 202 203 /* 204 * Open the image, read and validate the ELF header 205 */ 206 if (filename == NULL) /* can't handle nameless */ 207 return (EFTYPE); 208 if ((ef->fd = open(filename, O_RDONLY)) == -1) 209 return (errno); 210 ef->firstpage = malloc(PAGE_SIZE); 211 if (ef->firstpage == NULL) { 212 close(ef->fd); 213 return (ENOMEM); 214 } 215 bytes_read = read(ef->fd, ef->firstpage, PAGE_SIZE); 216 ef->firstlen = (size_t)bytes_read; 217 if (bytes_read < 0 || ef->firstlen <= sizeof(Elf_Ehdr)) { 218 err = EFTYPE; /* could be EIO, but may be small file */ 219 goto error; 220 } 221 ehdr = ef->ehdr = (Elf_Ehdr *)ef->firstpage; 222 223 /* Is it ELF? */ 224 if (!IS_ELF(*ehdr)) { 225 err = EFTYPE; 226 goto error; 227 } 228 229 if (ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || /* Layout ? */ 230 ehdr->e_ident[EI_DATA] != ELF_TARG_DATA || 231 ehdr->e_ident[EI_VERSION] != EV_CURRENT) /* Version ? */ { 232 err = EFTYPE; 233 goto error; 234 } 235 236 err = elf_header_convert(ehdr); 237 if (err) 238 goto error; 239 240 if (ehdr->e_version != EV_CURRENT || ehdr->e_machine != ELF_TARG_MACH) { /* Machine ? */ 241 err = EFTYPE; 242 goto error; 243 } 244 245 return (0); 246 247 error: 248 if (ef->firstpage != NULL) { 249 free(ef->firstpage); 250 ef->firstpage = NULL; 251 } 252 if (ef->fd != -1) { 253 close(ef->fd); 254 ef->fd = -1; 255 } 256 return (err); 257 } 258 259 /* 260 * Attempt to load the file (file) as an ELF module. It will be stored at 261 * (dest), and a pointer to a module structure describing the loaded object 262 * will be saved in (result). 263 */ 264 int 265 __elfN(loadfile)(char *filename, u_int64_t dest, struct preloaded_file **result) 266 { 267 return (__elfN(loadfile_raw)(filename, dest, result, 0)); 268 } 269 270 int 271 __elfN(loadfile_raw)(char *filename, u_int64_t dest, 272 struct preloaded_file **result, int multiboot) 273 { 274 struct preloaded_file *fp, *kfp; 275 struct elf_file ef; 276 Elf_Ehdr *ehdr; 277 int err; 278 279 fp = NULL; 280 bzero(&ef, sizeof(struct elf_file)); 281 ef.fd = -1; 282 283 err = __elfN(load_elf_header)(filename, &ef); 284 if (err != 0) 285 return (err); 286 287 ehdr = ef.ehdr; 288 289 /* 290 * Check to see what sort of module we are. 291 */ 292 kfp = file_findfile(NULL, __elfN(kerneltype)); 293 #ifdef __powerpc__ 294 /* 295 * Kernels can be ET_DYN, so just assume the first loaded object is the 296 * kernel. This assumption will be checked later. 297 */ 298 if (kfp == NULL) 299 ef.kernel = 1; 300 #endif 301 if (ef.kernel || ehdr->e_type == ET_EXEC) { 302 /* Looks like a kernel */ 303 if (kfp != NULL) { 304 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: kernel already loaded\n"); 305 err = EPERM; 306 goto oerr; 307 } 308 /* 309 * Calculate destination address based on kernel entrypoint. 310 * 311 * For ARM, the destination address is independent of any values in the 312 * elf header (an ARM kernel can be loaded at any 2MB boundary), so we 313 * leave dest set to the value calculated by archsw.arch_loadaddr() and 314 * passed in to this function. 315 */ 316 #ifndef __arm__ 317 if (ehdr->e_type == ET_EXEC) 318 dest = (ehdr->e_entry & ~PAGE_MASK); 319 #endif 320 if ((ehdr->e_entry & ~PAGE_MASK) == 0) { 321 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: not a kernel (maybe static binary?)\n"); 322 err = EPERM; 323 goto oerr; 324 } 325 ef.kernel = 1; 326 327 } else if (ehdr->e_type == ET_DYN) { 328 /* Looks like a kld module */ 329 if (multiboot != 0) { 330 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module as multiboot\n"); 331 err = EPERM; 332 goto oerr; 333 } 334 if (kfp == NULL) { 335 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module before kernel\n"); 336 err = EPERM; 337 goto oerr; 338 } 339 if (strcmp(__elfN(kerneltype), kfp->f_type)) { 340 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module with kernel type '%s'\n", kfp->f_type); 341 err = EPERM; 342 goto oerr; 343 } 344 /* Looks OK, got ahead */ 345 ef.kernel = 0; 346 347 } else { 348 err = EFTYPE; 349 goto oerr; 350 } 351 352 if (archsw.arch_loadaddr != NULL) 353 dest = archsw.arch_loadaddr(LOAD_ELF, ehdr, dest); 354 else 355 dest = roundup(dest, PAGE_SIZE); 356 357 /* 358 * Ok, we think we should handle this. 359 */ 360 fp = file_alloc(); 361 if (fp == NULL) { 362 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: cannot allocate module info\n"); 363 err = EPERM; 364 goto out; 365 } 366 if (ef.kernel == 1 && multiboot == 0) 367 setenv("kernelname", filename, 1); 368 fp->f_name = strdup(filename); 369 if (multiboot == 0) 370 fp->f_type = strdup(ef.kernel ? 371 __elfN(kerneltype) : __elfN(moduletype)); 372 else 373 fp->f_type = strdup("elf multiboot kernel"); 374 375 #ifdef ELF_VERBOSE 376 if (ef.kernel) 377 printf("%s entry at 0x%jx\n", filename, (uintmax_t)ehdr->e_entry); 378 #else 379 printf("%s ", filename); 380 #endif 381 382 fp->f_size = __elfN(loadimage)(fp, &ef, dest); 383 if (fp->f_size == 0 || fp->f_addr == 0) 384 goto ioerr; 385 386 /* save exec header as metadata */ 387 file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*ehdr), ehdr); 388 389 /* Load OK, return module pointer */ 390 *result = (struct preloaded_file *)fp; 391 err = 0; 392 goto out; 393 394 ioerr: 395 err = EIO; 396 oerr: 397 file_discard(fp); 398 out: 399 if (ef.firstpage) 400 free(ef.firstpage); 401 if (ef.fd != -1) 402 close(ef.fd); 403 return(err); 404 } 405 406 /* 407 * With the file (fd) open on the image, and (ehdr) containing 408 * the Elf header, load the image at (off) 409 */ 410 static int 411 __elfN(loadimage)(struct preloaded_file *fp, elf_file_t ef, u_int64_t off) 412 { 413 int i; 414 u_int j; 415 Elf_Ehdr *ehdr; 416 Elf_Phdr *phdr, *php; 417 Elf_Shdr *shdr; 418 char *shstr; 419 int ret; 420 vm_offset_t firstaddr; 421 vm_offset_t lastaddr; 422 size_t chunk; 423 ssize_t result; 424 Elf_Addr ssym, esym; 425 Elf_Dyn *dp; 426 Elf_Addr adp; 427 Elf_Addr ctors; 428 int ndp; 429 int symstrindex; 430 int symtabindex; 431 Elf_Size size; 432 u_int fpcopy; 433 Elf_Sym sym; 434 Elf_Addr p_start, p_end; 435 436 dp = NULL; 437 shdr = NULL; 438 ret = 0; 439 firstaddr = lastaddr = 0; 440 ehdr = ef->ehdr; 441 if (ehdr->e_type == ET_EXEC) { 442 #if defined(__i386__) || defined(__amd64__) 443 #if __ELF_WORD_SIZE == 64 444 off = - (off & 0xffffffffff000000ull);/* x86_64 relocates after locore */ 445 #else 446 off = - (off & 0xff000000u); /* i386 relocates after locore */ 447 #endif 448 #elif defined(__powerpc__) 449 /* 450 * On the purely virtual memory machines like e500, the kernel is 451 * linked against its final VA range, which is most often not 452 * available at the loader stage, but only after kernel initializes 453 * and completes its VM settings. In such cases we cannot use p_vaddr 454 * field directly to load ELF segments, but put them at some 455 * 'load-time' locations. 456 */ 457 if (off & 0xf0000000u) { 458 off = -(off & 0xf0000000u); 459 /* 460 * XXX the physical load address should not be hardcoded. Note 461 * that the Book-E kernel assumes that it's loaded at a 16MB 462 * boundary for now... 463 */ 464 off += 0x01000000; 465 ehdr->e_entry += off; 466 #ifdef ELF_VERBOSE 467 printf("Converted entry 0x%08x\n", ehdr->e_entry); 468 #endif 469 } else 470 off = 0; 471 #elif defined(__arm__) && !defined(EFI) 472 /* 473 * The elf headers in arm kernels specify virtual addresses in all 474 * header fields, even the ones that should be physical addresses. 475 * We assume the entry point is in the first page, and masking the page 476 * offset will leave us with the virtual address the kernel was linked 477 * at. We subtract that from the load offset, making 'off' into the 478 * value which, when added to a virtual address in an elf header, 479 * translates it to a physical address. We do the va->pa conversion on 480 * the entry point address in the header now, so that later we can 481 * launch the kernel by just jumping to that address. 482 * 483 * When booting from UEFI the copyin and copyout functions handle 484 * adjusting the location relative to the first virtual address. 485 * Because of this there is no need to adjust the offset or entry 486 * point address as these will both be handled by the efi code. 487 */ 488 off -= ehdr->e_entry & ~PAGE_MASK; 489 ehdr->e_entry += off; 490 #ifdef ELF_VERBOSE 491 printf("ehdr->e_entry 0x%08x, va<->pa off %llx\n", ehdr->e_entry, off); 492 #endif 493 #else 494 off = 0; /* other archs use direct mapped kernels */ 495 #endif 496 } 497 ef->off = off; 498 499 if (ef->kernel) 500 __elfN(relocation_offset) = off; 501 502 if ((ehdr->e_phoff + ehdr->e_phnum * sizeof(*phdr)) > ef->firstlen) { 503 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: program header not within first page\n"); 504 goto out; 505 } 506 phdr = (Elf_Phdr *)(ef->firstpage + ehdr->e_phoff); 507 508 for (i = 0; i < ehdr->e_phnum; i++) { 509 if (elf_program_header_convert(ehdr, phdr)) 510 continue; 511 512 /* We want to load PT_LOAD segments only.. */ 513 if (phdr[i].p_type != PT_LOAD) 514 continue; 515 516 #ifdef ELF_VERBOSE 517 printf("Segment: 0x%lx@0x%lx -> 0x%lx-0x%lx", 518 (long)phdr[i].p_filesz, (long)phdr[i].p_offset, 519 (long)(phdr[i].p_vaddr + off), 520 (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1)); 521 #else 522 if ((phdr[i].p_flags & PF_W) == 0) { 523 printf("text=0x%lx ", (long)phdr[i].p_filesz); 524 } else { 525 printf("data=0x%lx", (long)phdr[i].p_filesz); 526 if (phdr[i].p_filesz < phdr[i].p_memsz) 527 printf("+0x%lx", (long)(phdr[i].p_memsz -phdr[i].p_filesz)); 528 printf(" "); 529 } 530 #endif 531 fpcopy = 0; 532 if (ef->firstlen > phdr[i].p_offset) { 533 fpcopy = ef->firstlen - phdr[i].p_offset; 534 archsw.arch_copyin(ef->firstpage + phdr[i].p_offset, 535 phdr[i].p_vaddr + off, fpcopy); 536 } 537 if (phdr[i].p_filesz > fpcopy) { 538 if (kern_pread(ef->fd, phdr[i].p_vaddr + off + fpcopy, 539 phdr[i].p_filesz - fpcopy, phdr[i].p_offset + fpcopy) != 0) { 540 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 541 "_loadimage: read failed\n"); 542 goto out; 543 } 544 } 545 /* clear space from oversized segments; eg: bss */ 546 if (phdr[i].p_filesz < phdr[i].p_memsz) { 547 #ifdef ELF_VERBOSE 548 printf(" (bss: 0x%lx-0x%lx)", 549 (long)(phdr[i].p_vaddr + off + phdr[i].p_filesz), 550 (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1)); 551 #endif 552 553 kern_bzero(phdr[i].p_vaddr + off + phdr[i].p_filesz, 554 phdr[i].p_memsz - phdr[i].p_filesz); 555 } 556 #ifdef ELF_VERBOSE 557 printf("\n"); 558 #endif 559 560 if (archsw.arch_loadseg != NULL) 561 archsw.arch_loadseg(ehdr, phdr + i, off); 562 563 if (firstaddr == 0 || firstaddr > (phdr[i].p_vaddr + off)) 564 firstaddr = phdr[i].p_vaddr + off; 565 if (lastaddr == 0 || lastaddr < (phdr[i].p_vaddr + off + phdr[i].p_memsz)) 566 lastaddr = phdr[i].p_vaddr + off + phdr[i].p_memsz; 567 } 568 lastaddr = roundup(lastaddr, sizeof(long)); 569 570 /* 571 * Get the section headers. We need this for finding the .ctors 572 * section as well as for loading any symbols. Both may be hard 573 * to do if reading from a .gz file as it involves seeking. I 574 * think the rule is going to have to be that you must strip a 575 * file to remove symbols before gzipping it. 576 */ 577 chunk = (size_t)ehdr->e_shnum * (size_t)ehdr->e_shentsize; 578 if (chunk == 0 || ehdr->e_shoff == 0) 579 goto nosyms; 580 shdr = alloc_pread(ef->fd, ehdr->e_shoff, chunk); 581 if (shdr == NULL) { 582 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 583 "_loadimage: failed to read section headers"); 584 goto nosyms; 585 } 586 587 for (i = 0; i < ehdr->e_shnum; i++) 588 elf_section_header_convert(ehdr, &shdr[i]); 589 590 file_addmetadata(fp, MODINFOMD_SHDR, chunk, shdr); 591 592 /* 593 * Read the section string table and look for the .ctors section. 594 * We need to tell the kernel where it is so that it can call the 595 * ctors. 596 */ 597 chunk = shdr[ehdr->e_shstrndx].sh_size; 598 if (chunk) { 599 shstr = alloc_pread(ef->fd, shdr[ehdr->e_shstrndx].sh_offset, chunk); 600 if (shstr) { 601 for (i = 0; i < ehdr->e_shnum; i++) { 602 if (strcmp(shstr + shdr[i].sh_name, ".ctors") != 0) 603 continue; 604 ctors = shdr[i].sh_addr; 605 file_addmetadata(fp, MODINFOMD_CTORS_ADDR, sizeof(ctors), 606 &ctors); 607 size = shdr[i].sh_size; 608 file_addmetadata(fp, MODINFOMD_CTORS_SIZE, sizeof(size), 609 &size); 610 break; 611 } 612 free(shstr); 613 } 614 } 615 616 /* 617 * Now load any symbols. 618 */ 619 symtabindex = -1; 620 symstrindex = -1; 621 for (i = 0; i < ehdr->e_shnum; i++) { 622 if (shdr[i].sh_type != SHT_SYMTAB) 623 continue; 624 for (j = 0; j < ehdr->e_phnum; j++) { 625 if (phdr[j].p_type != PT_LOAD) 626 continue; 627 if (shdr[i].sh_offset >= phdr[j].p_offset && 628 (shdr[i].sh_offset + shdr[i].sh_size <= 629 phdr[j].p_offset + phdr[j].p_filesz)) { 630 shdr[i].sh_offset = 0; 631 shdr[i].sh_size = 0; 632 break; 633 } 634 } 635 if (shdr[i].sh_offset == 0 || shdr[i].sh_size == 0) 636 continue; /* alread loaded in a PT_LOAD above */ 637 /* Save it for loading below */ 638 symtabindex = i; 639 symstrindex = shdr[i].sh_link; 640 } 641 if (symtabindex < 0 || symstrindex < 0) 642 goto nosyms; 643 644 /* Ok, committed to a load. */ 645 #ifndef ELF_VERBOSE 646 printf("syms=["); 647 #endif 648 ssym = lastaddr; 649 for (i = symtabindex; i >= 0; i = symstrindex) { 650 #ifdef ELF_VERBOSE 651 char *secname; 652 653 switch(shdr[i].sh_type) { 654 case SHT_SYMTAB: /* Symbol table */ 655 secname = "symtab"; 656 break; 657 case SHT_STRTAB: /* String table */ 658 secname = "strtab"; 659 break; 660 default: 661 secname = "WHOA!!"; 662 break; 663 } 664 #endif 665 size = shdr[i].sh_size; 666 #if defined(__powerpc__) 667 #if __ELF_WORD_SIZE == 64 668 size = htobe64(size); 669 #else 670 size = htobe32(size); 671 #endif 672 #endif 673 674 archsw.arch_copyin(&size, lastaddr, sizeof(size)); 675 lastaddr += sizeof(size); 676 677 #ifdef ELF_VERBOSE 678 printf("\n%s: 0x%jx@0x%jx -> 0x%jx-0x%jx", secname, 679 (uintmax_t)shdr[i].sh_size, (uintmax_t)shdr[i].sh_offset, 680 (uintmax_t)lastaddr, (uintmax_t)(lastaddr + shdr[i].sh_size)); 681 #else 682 if (i == symstrindex) 683 printf("+"); 684 printf("0x%lx+0x%lx", (long)sizeof(size), (long)size); 685 #endif 686 687 if (lseek(ef->fd, (off_t)shdr[i].sh_offset, SEEK_SET) == -1) { 688 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not seek for symbols - skipped!"); 689 lastaddr = ssym; 690 ssym = 0; 691 goto nosyms; 692 } 693 result = archsw.arch_readin(ef->fd, lastaddr, shdr[i].sh_size); 694 if (result < 0 || (size_t)result != shdr[i].sh_size) { 695 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not read symbols - skipped! (%ju != %ju)", (uintmax_t)result, 696 (uintmax_t)shdr[i].sh_size); 697 lastaddr = ssym; 698 ssym = 0; 699 goto nosyms; 700 } 701 /* Reset offsets relative to ssym */ 702 lastaddr += shdr[i].sh_size; 703 lastaddr = roundup(lastaddr, sizeof(size)); 704 if (i == symtabindex) 705 symtabindex = -1; 706 else if (i == symstrindex) 707 symstrindex = -1; 708 } 709 esym = lastaddr; 710 #ifndef ELF_VERBOSE 711 printf("]"); 712 #endif 713 714 #if defined(__powerpc__) 715 /* On PowerPC we always need to provide BE data to the kernel */ 716 #if __ELF_WORD_SIZE == 64 717 ssym = htobe64((uint64_t)ssym); 718 esym = htobe64((uint64_t)esym); 719 #else 720 ssym = htobe32((uint32_t)ssym); 721 esym = htobe32((uint32_t)esym); 722 #endif 723 #endif 724 725 file_addmetadata(fp, MODINFOMD_SSYM, sizeof(ssym), &ssym); 726 file_addmetadata(fp, MODINFOMD_ESYM, sizeof(esym), &esym); 727 728 nosyms: 729 printf("\n"); 730 731 ret = lastaddr - firstaddr; 732 fp->f_addr = firstaddr; 733 734 php = NULL; 735 for (i = 0; i < ehdr->e_phnum; i++) { 736 if (phdr[i].p_type == PT_DYNAMIC) { 737 php = phdr + i; 738 adp = php->p_vaddr; 739 file_addmetadata(fp, MODINFOMD_DYNAMIC, sizeof(adp), &adp); 740 break; 741 } 742 } 743 744 if (php == NULL) /* this is bad, we cannot get to symbols or _DYNAMIC */ 745 goto out; 746 747 ndp = php->p_filesz / sizeof(Elf_Dyn); 748 if (ndp == 0) 749 goto out; 750 dp = malloc(php->p_filesz); 751 if (dp == NULL) 752 goto out; 753 archsw.arch_copyout(php->p_vaddr + off, dp, php->p_filesz); 754 755 ef->strsz = 0; 756 for (i = 0; i < ndp; i++) { 757 if (dp[i].d_tag == 0) 758 break; 759 switch (dp[i].d_tag) { 760 case DT_HASH: 761 ef->hashtab = (Elf_Hashelt*)(uintptr_t)(dp[i].d_un.d_ptr + off); 762 break; 763 case DT_STRTAB: 764 ef->strtab = (char *)(uintptr_t)(dp[i].d_un.d_ptr + off); 765 break; 766 case DT_STRSZ: 767 ef->strsz = dp[i].d_un.d_val; 768 break; 769 case DT_SYMTAB: 770 ef->symtab = (Elf_Sym*)(uintptr_t)(dp[i].d_un.d_ptr + off); 771 break; 772 case DT_REL: 773 ef->rel = (Elf_Rel *)(uintptr_t)(dp[i].d_un.d_ptr + off); 774 break; 775 case DT_RELSZ: 776 ef->relsz = dp[i].d_un.d_val; 777 break; 778 case DT_RELA: 779 ef->rela = (Elf_Rela *)(uintptr_t)(dp[i].d_un.d_ptr + off); 780 break; 781 case DT_RELASZ: 782 ef->relasz = dp[i].d_un.d_val; 783 break; 784 default: 785 break; 786 } 787 } 788 if (ef->hashtab == NULL || ef->symtab == NULL || 789 ef->strtab == NULL || ef->strsz == 0) 790 goto out; 791 COPYOUT(ef->hashtab, &ef->nbuckets, sizeof(ef->nbuckets)); 792 COPYOUT(ef->hashtab + 1, &ef->nchains, sizeof(ef->nchains)); 793 ef->buckets = ef->hashtab + 2; 794 ef->chains = ef->buckets + ef->nbuckets; 795 796 if (__elfN(lookup_symbol)(fp, ef, "__start_set_modmetadata_set", &sym) != 0) 797 return 0; 798 p_start = sym.st_value + ef->off; 799 if (__elfN(lookup_symbol)(fp, ef, "__stop_set_modmetadata_set", &sym) != 0) 800 return ENOENT; 801 p_end = sym.st_value + ef->off; 802 803 if (__elfN(parse_modmetadata)(fp, ef, p_start, p_end) == 0) 804 goto out; 805 806 if (ef->kernel) /* kernel must not depend on anything */ 807 goto out; 808 809 out: 810 if (dp) 811 free(dp); 812 if (shdr) 813 free(shdr); 814 return ret; 815 } 816 817 static char invalid_name[] = "bad"; 818 819 char * 820 fake_modname(const char *name) 821 { 822 const char *sp, *ep; 823 char *fp; 824 size_t len; 825 826 sp = strrchr(name, '/'); 827 if (sp) 828 sp++; 829 else 830 sp = name; 831 ep = strrchr(name, '.'); 832 if (ep) { 833 if (ep == name) { 834 sp = invalid_name; 835 ep = invalid_name + sizeof(invalid_name) - 1; 836 } 837 } else 838 ep = name + strlen(name); 839 len = ep - sp; 840 fp = malloc(len + 1); 841 if (fp == NULL) 842 return NULL; 843 memcpy(fp, sp, len); 844 fp[len] = '\0'; 845 return fp; 846 } 847 848 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64 849 struct mod_metadata64 { 850 int md_version; /* structure version MDTV_* */ 851 int md_type; /* type of entry MDT_* */ 852 u_int64_t md_data; /* specific data */ 853 u_int64_t md_cval; /* common string label */ 854 }; 855 #endif 856 #if defined(__amd64__) && __ELF_WORD_SIZE == 32 857 struct mod_metadata32 { 858 int md_version; /* structure version MDTV_* */ 859 int md_type; /* type of entry MDT_* */ 860 u_int32_t md_data; /* specific data */ 861 u_int32_t md_cval; /* common string label */ 862 }; 863 #endif 864 865 int 866 __elfN(load_modmetadata)(struct preloaded_file *fp, u_int64_t dest) 867 { 868 struct elf_file ef; 869 int err, i, j; 870 Elf_Shdr *sh_meta, *shdr = NULL; 871 Elf_Shdr *sh_data[2]; 872 char *shstrtab = NULL; 873 size_t size; 874 Elf_Addr p_start, p_end; 875 876 bzero(&ef, sizeof(struct elf_file)); 877 ef.fd = -1; 878 879 err = __elfN(load_elf_header)(fp->f_name, &ef); 880 if (err != 0) 881 goto out; 882 883 if (ef.kernel == 1 || ef.ehdr->e_type == ET_EXEC) { 884 ef.kernel = 1; 885 } else if (ef.ehdr->e_type != ET_DYN) { 886 err = EFTYPE; 887 goto out; 888 } 889 890 size = (size_t)ef.ehdr->e_shnum * (size_t)ef.ehdr->e_shentsize; 891 shdr = alloc_pread(ef.fd, ef.ehdr->e_shoff, size); 892 if (shdr == NULL) { 893 err = ENOMEM; 894 goto out; 895 } 896 897 /* Load shstrtab. */ 898 shstrtab = alloc_pread(ef.fd, shdr[ef.ehdr->e_shstrndx].sh_offset, 899 shdr[ef.ehdr->e_shstrndx].sh_size); 900 if (shstrtab == NULL) { 901 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 902 "load_modmetadata: unable to load shstrtab\n"); 903 err = EFTYPE; 904 goto out; 905 } 906 907 /* Find set_modmetadata_set and data sections. */ 908 sh_data[0] = sh_data[1] = sh_meta = NULL; 909 for (i = 0, j = 0; i < ef.ehdr->e_shnum; i++) { 910 if (strcmp(&shstrtab[shdr[i].sh_name], 911 "set_modmetadata_set") == 0) { 912 sh_meta = &shdr[i]; 913 } 914 if ((strcmp(&shstrtab[shdr[i].sh_name], ".data") == 0) || 915 (strcmp(&shstrtab[shdr[i].sh_name], ".rodata") == 0)) { 916 sh_data[j++] = &shdr[i]; 917 } 918 } 919 if (sh_meta == NULL || sh_data[0] == NULL || sh_data[1] == NULL) { 920 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 921 "load_modmetadata: unable to find set_modmetadata_set or data sections\n"); 922 err = EFTYPE; 923 goto out; 924 } 925 926 /* Load set_modmetadata_set into memory */ 927 err = kern_pread(ef.fd, dest, sh_meta->sh_size, sh_meta->sh_offset); 928 if (err != 0) { 929 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 930 "load_modmetadata: unable to load set_modmetadata_set: %d\n", err); 931 goto out; 932 } 933 p_start = dest; 934 p_end = dest + sh_meta->sh_size; 935 dest += sh_meta->sh_size; 936 937 /* Load data sections into memory. */ 938 err = kern_pread(ef.fd, dest, sh_data[0]->sh_size, 939 sh_data[0]->sh_offset); 940 if (err != 0) { 941 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 942 "load_modmetadata: unable to load data: %d\n", err); 943 goto out; 944 } 945 946 /* 947 * We have to increment the dest, so that the offset is the same into 948 * both the .rodata and .data sections. 949 */ 950 ef.off = -(sh_data[0]->sh_addr - dest); 951 dest += (sh_data[1]->sh_addr - sh_data[0]->sh_addr); 952 953 err = kern_pread(ef.fd, dest, sh_data[1]->sh_size, 954 sh_data[1]->sh_offset); 955 if (err != 0) { 956 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 957 "load_modmetadata: unable to load data: %d\n", err); 958 goto out; 959 } 960 961 err = __elfN(parse_modmetadata)(fp, &ef, p_start, p_end); 962 if (err != 0) { 963 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 964 "load_modmetadata: unable to parse metadata: %d\n", err); 965 goto out; 966 } 967 968 out: 969 if (shstrtab != NULL) 970 free(shstrtab); 971 if (shdr != NULL) 972 free(shdr); 973 if (ef.firstpage != NULL) 974 free(ef.firstpage); 975 if (ef.fd != -1) 976 close(ef.fd); 977 return (err); 978 } 979 980 int 981 __elfN(parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef, 982 Elf_Addr p_start, Elf_Addr p_end) 983 { 984 struct mod_metadata md; 985 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64 986 struct mod_metadata64 md64; 987 #elif defined(__amd64__) && __ELF_WORD_SIZE == 32 988 struct mod_metadata32 md32; 989 #endif 990 struct mod_depend *mdepend; 991 struct mod_version mver; 992 char *s; 993 int error, modcnt, minfolen; 994 Elf_Addr v, p; 995 996 modcnt = 0; 997 p = p_start; 998 while (p < p_end) { 999 COPYOUT(p, &v, sizeof(v)); 1000 error = __elfN(reloc_ptr)(fp, ef, p, &v, sizeof(v)); 1001 if (error == EOPNOTSUPP) 1002 v += ef->off; 1003 else if (error != 0) 1004 return (error); 1005 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64 1006 COPYOUT(v, &md64, sizeof(md64)); 1007 error = __elfN(reloc_ptr)(fp, ef, v, &md64, sizeof(md64)); 1008 if (error == EOPNOTSUPP) { 1009 md64.md_cval += ef->off; 1010 md64.md_data += ef->off; 1011 } else if (error != 0) 1012 return (error); 1013 md.md_version = md64.md_version; 1014 md.md_type = md64.md_type; 1015 md.md_cval = (const char *)(uintptr_t)md64.md_cval; 1016 md.md_data = (void *)(uintptr_t)md64.md_data; 1017 #elif defined(__amd64__) && __ELF_WORD_SIZE == 32 1018 COPYOUT(v, &md32, sizeof(md32)); 1019 error = __elfN(reloc_ptr)(fp, ef, v, &md32, sizeof(md32)); 1020 if (error == EOPNOTSUPP) { 1021 md32.md_cval += ef->off; 1022 md32.md_data += ef->off; 1023 } else if (error != 0) 1024 return (error); 1025 md.md_version = md32.md_version; 1026 md.md_type = md32.md_type; 1027 md.md_cval = (const char *)(uintptr_t)md32.md_cval; 1028 md.md_data = (void *)(uintptr_t)md32.md_data; 1029 #else 1030 COPYOUT(v, &md, sizeof(md)); 1031 error = __elfN(reloc_ptr)(fp, ef, v, &md, sizeof(md)); 1032 if (error == EOPNOTSUPP) { 1033 md.md_cval += ef->off; 1034 md.md_data = (void *)((uintptr_t)md.md_data + (uintptr_t)ef->off); 1035 } else if (error != 0) 1036 return (error); 1037 #endif 1038 p += sizeof(Elf_Addr); 1039 switch(md.md_type) { 1040 case MDT_DEPEND: 1041 if (ef->kernel) /* kernel must not depend on anything */ 1042 break; 1043 s = strdupout((vm_offset_t)md.md_cval); 1044 minfolen = sizeof(*mdepend) + strlen(s) + 1; 1045 mdepend = malloc(minfolen); 1046 if (mdepend == NULL) 1047 return ENOMEM; 1048 COPYOUT((vm_offset_t)md.md_data, mdepend, sizeof(*mdepend)); 1049 strcpy((char*)(mdepend + 1), s); 1050 free(s); 1051 file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen, mdepend); 1052 free(mdepend); 1053 break; 1054 case MDT_VERSION: 1055 s = strdupout((vm_offset_t)md.md_cval); 1056 COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver)); 1057 file_addmodule(fp, s, mver.mv_version, NULL); 1058 free(s); 1059 modcnt++; 1060 break; 1061 } 1062 } 1063 if (modcnt == 0) { 1064 s = fake_modname(fp->f_name); 1065 file_addmodule(fp, s, 1, NULL); 1066 free(s); 1067 } 1068 return 0; 1069 } 1070 1071 static unsigned long 1072 elf_hash(const char *name) 1073 { 1074 const unsigned char *p = (const unsigned char *) name; 1075 unsigned long h = 0; 1076 unsigned long g; 1077 1078 while (*p != '\0') { 1079 h = (h << 4) + *p++; 1080 if ((g = h & 0xf0000000) != 0) 1081 h ^= g >> 24; 1082 h &= ~g; 1083 } 1084 return h; 1085 } 1086 1087 static const char __elfN(bad_symtable)[] = "elf" __XSTRING(__ELF_WORD_SIZE) "_lookup_symbol: corrupt symbol table\n"; 1088 int 1089 __elfN(lookup_symbol)(struct preloaded_file *fp, elf_file_t ef, const char* name, 1090 Elf_Sym *symp) 1091 { 1092 Elf_Hashelt symnum; 1093 Elf_Sym sym; 1094 char *strp; 1095 unsigned long hash; 1096 1097 hash = elf_hash(name); 1098 COPYOUT(&ef->buckets[hash % ef->nbuckets], &symnum, sizeof(symnum)); 1099 1100 while (symnum != STN_UNDEF) { 1101 if (symnum >= ef->nchains) { 1102 printf(__elfN(bad_symtable)); 1103 return ENOENT; 1104 } 1105 1106 COPYOUT(ef->symtab + symnum, &sym, sizeof(sym)); 1107 if (sym.st_name == 0) { 1108 printf(__elfN(bad_symtable)); 1109 return ENOENT; 1110 } 1111 1112 strp = strdupout((vm_offset_t)(ef->strtab + sym.st_name)); 1113 if (strcmp(name, strp) == 0) { 1114 free(strp); 1115 if (sym.st_shndx != SHN_UNDEF || 1116 (sym.st_value != 0 && 1117 ELF_ST_TYPE(sym.st_info) == STT_FUNC)) { 1118 *symp = sym; 1119 return 0; 1120 } 1121 return ENOENT; 1122 } 1123 free(strp); 1124 COPYOUT(&ef->chains[symnum], &symnum, sizeof(symnum)); 1125 } 1126 return ENOENT; 1127 } 1128 1129 /* 1130 * Apply any intra-module relocations to the value. p is the load address 1131 * of the value and val/len is the value to be modified. This does NOT modify 1132 * the image in-place, because this is done by kern_linker later on. 1133 * 1134 * Returns EOPNOTSUPP if no relocation method is supplied. 1135 */ 1136 static int 1137 __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, 1138 Elf_Addr p, void *val, size_t len) 1139 { 1140 size_t n; 1141 Elf_Rela a; 1142 Elf_Rel r; 1143 int error; 1144 1145 /* 1146 * The kernel is already relocated, but we still want to apply 1147 * offset adjustments. 1148 */ 1149 if (ef->kernel) 1150 return (EOPNOTSUPP); 1151 1152 for (n = 0; n < ef->relsz / sizeof(r); n++) { 1153 COPYOUT(ef->rel + n, &r, sizeof(r)); 1154 1155 error = __elfN(reloc)(ef, __elfN(symaddr), &r, ELF_RELOC_REL, 1156 ef->off, p, val, len); 1157 if (error != 0) 1158 return (error); 1159 } 1160 for (n = 0; n < ef->relasz / sizeof(a); n++) { 1161 COPYOUT(ef->rela + n, &a, sizeof(a)); 1162 1163 error = __elfN(reloc)(ef, __elfN(symaddr), &a, ELF_RELOC_RELA, 1164 ef->off, p, val, len); 1165 if (error != 0) 1166 return (error); 1167 } 1168 1169 return (0); 1170 } 1171 1172 static Elf_Addr 1173 __elfN(symaddr)(struct elf_file *ef, Elf_Size symidx) 1174 { 1175 1176 /* Symbol lookup by index not required here. */ 1177 return (0); 1178 } 1179