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/exec.h> 33 #include <sys/linker.h> 34 #include <sys/module.h> 35 #include <sys/stdint.h> 36 #include <string.h> 37 #include <machine/elf.h> 38 #include <stand.h> 39 #define FREEBSD_ELF 40 #include <link.h> 41 42 #include "bootstrap.h" 43 44 #define COPYOUT(s,d,l) archsw.arch_copyout((vm_offset_t)(s), d, l) 45 46 #if defined(__i386__) && __ELF_WORD_SIZE == 64 47 #undef ELF_TARG_CLASS 48 #undef ELF_TARG_MACH 49 #define ELF_TARG_CLASS ELFCLASS64 50 #define ELF_TARG_MACH EM_X86_64 51 #endif 52 53 typedef struct elf_file { 54 Elf_Phdr *ph; 55 Elf_Ehdr *ehdr; 56 Elf_Sym *symtab; 57 Elf_Hashelt *hashtab; 58 Elf_Hashelt nbuckets; 59 Elf_Hashelt nchains; 60 Elf_Hashelt *buckets; 61 Elf_Hashelt *chains; 62 Elf_Rel *rel; 63 size_t relsz; 64 Elf_Rela *rela; 65 size_t relasz; 66 char *strtab; 67 size_t strsz; 68 int fd; 69 caddr_t firstpage; 70 size_t firstlen; 71 int kernel; 72 u_int64_t off; 73 } *elf_file_t; 74 75 static int __elfN(loadimage)(struct preloaded_file *mp, elf_file_t ef, u_int64_t loadaddr); 76 static int __elfN(lookup_symbol)(struct preloaded_file *mp, elf_file_t ef, const char* name, Elf_Sym* sym); 77 static int __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, 78 Elf_Addr p, void *val, size_t len); 79 static int __elfN(parse_modmetadata)(struct preloaded_file *mp, elf_file_t ef, 80 Elf_Addr p_start, Elf_Addr p_end); 81 static symaddr_fn __elfN(symaddr); 82 static char *fake_modname(const char *name); 83 84 const char *__elfN(kerneltype) = "elf kernel"; 85 const char *__elfN(moduletype) = "elf module"; 86 87 u_int64_t __elfN(relocation_offset) = 0; 88 89 static int 90 __elfN(load_elf_header)(char *filename, elf_file_t ef) 91 { 92 ssize_t bytes_read; 93 Elf_Ehdr *ehdr; 94 int err; 95 96 /* 97 * Open the image, read and validate the ELF header 98 */ 99 if (filename == NULL) /* can't handle nameless */ 100 return (EFTYPE); 101 if ((ef->fd = open(filename, O_RDONLY)) == -1) 102 return (errno); 103 ef->firstpage = malloc(PAGE_SIZE); 104 if (ef->firstpage == NULL) { 105 close(ef->fd); 106 return (ENOMEM); 107 } 108 bytes_read = read(ef->fd, ef->firstpage, PAGE_SIZE); 109 ef->firstlen = (size_t)bytes_read; 110 if (bytes_read < 0 || ef->firstlen <= sizeof(Elf_Ehdr)) { 111 err = EFTYPE; /* could be EIO, but may be small file */ 112 goto error; 113 } 114 ehdr = ef->ehdr = (Elf_Ehdr *)ef->firstpage; 115 116 /* Is it ELF? */ 117 if (!IS_ELF(*ehdr)) { 118 err = EFTYPE; 119 goto error; 120 } 121 if (ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || /* Layout ? */ 122 ehdr->e_ident[EI_DATA] != ELF_TARG_DATA || 123 ehdr->e_ident[EI_VERSION] != EV_CURRENT || /* Version ? */ 124 ehdr->e_version != EV_CURRENT || 125 ehdr->e_machine != ELF_TARG_MACH) { /* Machine ? */ 126 err = EFTYPE; 127 goto error; 128 } 129 130 return (0); 131 132 error: 133 if (ef->firstpage != NULL) { 134 free(ef->firstpage); 135 ef->firstpage = NULL; 136 } 137 if (ef->fd != -1) { 138 close(ef->fd); 139 ef->fd = -1; 140 } 141 return (err); 142 } 143 144 /* 145 * Attempt to load the file (file) as an ELF module. It will be stored at 146 * (dest), and a pointer to a module structure describing the loaded object 147 * will be saved in (result). 148 */ 149 int 150 __elfN(loadfile)(char *filename, u_int64_t dest, struct preloaded_file **result) 151 { 152 return (__elfN(loadfile_raw)(filename, dest, result, 0)); 153 } 154 155 int 156 __elfN(loadfile_raw)(char *filename, u_int64_t dest, 157 struct preloaded_file **result, int multiboot) 158 { 159 struct preloaded_file *fp, *kfp; 160 struct elf_file ef; 161 Elf_Ehdr *ehdr; 162 int err; 163 164 fp = NULL; 165 bzero(&ef, sizeof(struct elf_file)); 166 ef.fd = -1; 167 168 err = __elfN(load_elf_header)(filename, &ef); 169 if (err != 0) 170 return (err); 171 172 ehdr = ef.ehdr; 173 174 /* 175 * Check to see what sort of module we are. 176 */ 177 kfp = file_findfile(NULL, __elfN(kerneltype)); 178 #ifdef __powerpc__ 179 /* 180 * Kernels can be ET_DYN, so just assume the first loaded object is the 181 * kernel. This assumption will be checked later. 182 */ 183 if (kfp == NULL) 184 ef.kernel = 1; 185 #endif 186 if (ef.kernel || ehdr->e_type == ET_EXEC) { 187 /* Looks like a kernel */ 188 if (kfp != NULL) { 189 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: kernel already loaded\n"); 190 err = EPERM; 191 goto oerr; 192 } 193 /* 194 * Calculate destination address based on kernel entrypoint. 195 * 196 * For ARM, the destination address is independent of any values in the 197 * elf header (an ARM kernel can be loaded at any 2MB boundary), so we 198 * leave dest set to the value calculated by archsw.arch_loadaddr() and 199 * passed in to this function. 200 */ 201 #ifndef __arm__ 202 if (ehdr->e_type == ET_EXEC) 203 dest = (ehdr->e_entry & ~PAGE_MASK); 204 #endif 205 if ((ehdr->e_entry & ~PAGE_MASK) == 0) { 206 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: not a kernel (maybe static binary?)\n"); 207 err = EPERM; 208 goto oerr; 209 } 210 ef.kernel = 1; 211 212 } else if (ehdr->e_type == ET_DYN) { 213 /* Looks like a kld module */ 214 if (multiboot != 0) { 215 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module as multiboot\n"); 216 err = EPERM; 217 goto oerr; 218 } 219 if (kfp == NULL) { 220 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module before kernel\n"); 221 err = EPERM; 222 goto oerr; 223 } 224 if (strcmp(__elfN(kerneltype), kfp->f_type)) { 225 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module with kernel type '%s'\n", kfp->f_type); 226 err = EPERM; 227 goto oerr; 228 } 229 /* Looks OK, got ahead */ 230 ef.kernel = 0; 231 232 } else { 233 err = EFTYPE; 234 goto oerr; 235 } 236 237 if (archsw.arch_loadaddr != NULL) 238 dest = archsw.arch_loadaddr(LOAD_ELF, ehdr, dest); 239 else 240 dest = roundup(dest, PAGE_SIZE); 241 242 /* 243 * Ok, we think we should handle this. 244 */ 245 fp = file_alloc(); 246 if (fp == NULL) { 247 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: cannot allocate module info\n"); 248 err = EPERM; 249 goto out; 250 } 251 if (ef.kernel == 1 && multiboot == 0) 252 setenv("kernelname", filename, 1); 253 fp->f_name = strdup(filename); 254 if (multiboot == 0) 255 fp->f_type = strdup(ef.kernel ? 256 __elfN(kerneltype) : __elfN(moduletype)); 257 else 258 fp->f_type = strdup("elf multiboot kernel"); 259 260 #ifdef ELF_VERBOSE 261 if (ef.kernel) 262 printf("%s entry at 0x%jx\n", filename, (uintmax_t)ehdr->e_entry); 263 #else 264 printf("%s ", filename); 265 #endif 266 267 fp->f_size = __elfN(loadimage)(fp, &ef, dest); 268 if (fp->f_size == 0 || fp->f_addr == 0) 269 goto ioerr; 270 271 /* save exec header as metadata */ 272 file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*ehdr), ehdr); 273 274 /* Load OK, return module pointer */ 275 *result = (struct preloaded_file *)fp; 276 err = 0; 277 goto out; 278 279 ioerr: 280 err = EIO; 281 oerr: 282 file_discard(fp); 283 out: 284 if (ef.firstpage) 285 free(ef.firstpage); 286 if (ef.fd != -1) 287 close(ef.fd); 288 return(err); 289 } 290 291 /* 292 * With the file (fd) open on the image, and (ehdr) containing 293 * the Elf header, load the image at (off) 294 */ 295 static int 296 __elfN(loadimage)(struct preloaded_file *fp, elf_file_t ef, u_int64_t off) 297 { 298 int i; 299 u_int j; 300 Elf_Ehdr *ehdr; 301 Elf_Phdr *phdr, *php; 302 Elf_Shdr *shdr; 303 char *shstr; 304 int ret; 305 vm_offset_t firstaddr; 306 vm_offset_t lastaddr; 307 size_t chunk; 308 ssize_t result; 309 Elf_Addr ssym, esym; 310 Elf_Dyn *dp; 311 Elf_Addr adp; 312 Elf_Addr ctors; 313 int ndp; 314 int symstrindex; 315 int symtabindex; 316 Elf_Size size; 317 u_int fpcopy; 318 Elf_Sym sym; 319 Elf_Addr p_start, p_end; 320 321 dp = NULL; 322 shdr = NULL; 323 ret = 0; 324 firstaddr = lastaddr = 0; 325 ehdr = ef->ehdr; 326 if (ehdr->e_type == ET_EXEC) { 327 #if defined(__i386__) || defined(__amd64__) 328 #if __ELF_WORD_SIZE == 64 329 off = - (off & 0xffffffffff000000ull);/* x86_64 relocates after locore */ 330 #else 331 off = - (off & 0xff000000u); /* i386 relocates after locore */ 332 #endif 333 #elif defined(__powerpc__) 334 /* 335 * On the purely virtual memory machines like e500, the kernel is 336 * linked against its final VA range, which is most often not 337 * available at the loader stage, but only after kernel initializes 338 * and completes its VM settings. In such cases we cannot use p_vaddr 339 * field directly to load ELF segments, but put them at some 340 * 'load-time' locations. 341 */ 342 if (off & 0xf0000000u) { 343 off = -(off & 0xf0000000u); 344 /* 345 * XXX the physical load address should not be hardcoded. Note 346 * that the Book-E kernel assumes that it's loaded at a 16MB 347 * boundary for now... 348 */ 349 off += 0x01000000; 350 ehdr->e_entry += off; 351 #ifdef ELF_VERBOSE 352 printf("Converted entry 0x%08x\n", ehdr->e_entry); 353 #endif 354 } else 355 off = 0; 356 #elif defined(__arm__) && !defined(EFI) 357 /* 358 * The elf headers in arm kernels specify virtual addresses in all 359 * header fields, even the ones that should be physical addresses. 360 * We assume the entry point is in the first page, and masking the page 361 * offset will leave us with the virtual address the kernel was linked 362 * at. We subtract that from the load offset, making 'off' into the 363 * value which, when added to a virtual address in an elf header, 364 * translates it to a physical address. We do the va->pa conversion on 365 * the entry point address in the header now, so that later we can 366 * launch the kernel by just jumping to that address. 367 * 368 * When booting from UEFI the copyin and copyout functions handle 369 * adjusting the location relative to the first virtual address. 370 * Because of this there is no need to adjust the offset or entry 371 * point address as these will both be handled by the efi code. 372 */ 373 off -= ehdr->e_entry & ~PAGE_MASK; 374 ehdr->e_entry += off; 375 #ifdef ELF_VERBOSE 376 printf("ehdr->e_entry 0x%08x, va<->pa off %llx\n", ehdr->e_entry, off); 377 #endif 378 #else 379 off = 0; /* other archs use direct mapped kernels */ 380 #endif 381 } 382 ef->off = off; 383 384 if (ef->kernel) 385 __elfN(relocation_offset) = off; 386 387 if ((ehdr->e_phoff + ehdr->e_phnum * sizeof(*phdr)) > ef->firstlen) { 388 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: program header not within first page\n"); 389 goto out; 390 } 391 phdr = (Elf_Phdr *)(ef->firstpage + ehdr->e_phoff); 392 393 for (i = 0; i < ehdr->e_phnum; i++) { 394 /* We want to load PT_LOAD segments only.. */ 395 if (phdr[i].p_type != PT_LOAD) 396 continue; 397 398 #ifdef ELF_VERBOSE 399 printf("Segment: 0x%lx@0x%lx -> 0x%lx-0x%lx", 400 (long)phdr[i].p_filesz, (long)phdr[i].p_offset, 401 (long)(phdr[i].p_vaddr + off), 402 (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1)); 403 #else 404 if ((phdr[i].p_flags & PF_W) == 0) { 405 printf("text=0x%lx ", (long)phdr[i].p_filesz); 406 } else { 407 printf("data=0x%lx", (long)phdr[i].p_filesz); 408 if (phdr[i].p_filesz < phdr[i].p_memsz) 409 printf("+0x%lx", (long)(phdr[i].p_memsz -phdr[i].p_filesz)); 410 printf(" "); 411 } 412 #endif 413 fpcopy = 0; 414 if (ef->firstlen > phdr[i].p_offset) { 415 fpcopy = ef->firstlen - phdr[i].p_offset; 416 archsw.arch_copyin(ef->firstpage + phdr[i].p_offset, 417 phdr[i].p_vaddr + off, fpcopy); 418 } 419 if (phdr[i].p_filesz > fpcopy) { 420 if (kern_pread(ef->fd, phdr[i].p_vaddr + off + fpcopy, 421 phdr[i].p_filesz - fpcopy, phdr[i].p_offset + fpcopy) != 0) { 422 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 423 "_loadimage: read failed\n"); 424 goto out; 425 } 426 } 427 /* clear space from oversized segments; eg: bss */ 428 if (phdr[i].p_filesz < phdr[i].p_memsz) { 429 #ifdef ELF_VERBOSE 430 printf(" (bss: 0x%lx-0x%lx)", 431 (long)(phdr[i].p_vaddr + off + phdr[i].p_filesz), 432 (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1)); 433 #endif 434 435 kern_bzero(phdr[i].p_vaddr + off + phdr[i].p_filesz, 436 phdr[i].p_memsz - phdr[i].p_filesz); 437 } 438 #ifdef ELF_VERBOSE 439 printf("\n"); 440 #endif 441 442 if (archsw.arch_loadseg != NULL) 443 archsw.arch_loadseg(ehdr, phdr + i, off); 444 445 if (firstaddr == 0 || firstaddr > (phdr[i].p_vaddr + off)) 446 firstaddr = phdr[i].p_vaddr + off; 447 if (lastaddr == 0 || lastaddr < (phdr[i].p_vaddr + off + phdr[i].p_memsz)) 448 lastaddr = phdr[i].p_vaddr + off + phdr[i].p_memsz; 449 } 450 lastaddr = roundup(lastaddr, sizeof(long)); 451 452 /* 453 * Get the section headers. We need this for finding the .ctors 454 * section as well as for loading any symbols. Both may be hard 455 * to do if reading from a .gz file as it involves seeking. I 456 * think the rule is going to have to be that you must strip a 457 * file to remove symbols before gzipping it. 458 */ 459 chunk = ehdr->e_shnum * ehdr->e_shentsize; 460 if (chunk == 0 || ehdr->e_shoff == 0) 461 goto nosyms; 462 shdr = alloc_pread(ef->fd, ehdr->e_shoff, chunk); 463 if (shdr == NULL) { 464 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 465 "_loadimage: failed to read section headers"); 466 goto nosyms; 467 } 468 file_addmetadata(fp, MODINFOMD_SHDR, chunk, shdr); 469 470 /* 471 * Read the section string table and look for the .ctors section. 472 * We need to tell the kernel where it is so that it can call the 473 * ctors. 474 */ 475 chunk = shdr[ehdr->e_shstrndx].sh_size; 476 if (chunk) { 477 shstr = alloc_pread(ef->fd, shdr[ehdr->e_shstrndx].sh_offset, chunk); 478 if (shstr) { 479 for (i = 0; i < ehdr->e_shnum; i++) { 480 if (strcmp(shstr + shdr[i].sh_name, ".ctors") != 0) 481 continue; 482 ctors = shdr[i].sh_addr; 483 file_addmetadata(fp, MODINFOMD_CTORS_ADDR, sizeof(ctors), 484 &ctors); 485 size = shdr[i].sh_size; 486 file_addmetadata(fp, MODINFOMD_CTORS_SIZE, sizeof(size), 487 &size); 488 break; 489 } 490 free(shstr); 491 } 492 } 493 494 /* 495 * Now load any symbols. 496 */ 497 symtabindex = -1; 498 symstrindex = -1; 499 for (i = 0; i < ehdr->e_shnum; i++) { 500 if (shdr[i].sh_type != SHT_SYMTAB) 501 continue; 502 for (j = 0; j < ehdr->e_phnum; j++) { 503 if (phdr[j].p_type != PT_LOAD) 504 continue; 505 if (shdr[i].sh_offset >= phdr[j].p_offset && 506 (shdr[i].sh_offset + shdr[i].sh_size <= 507 phdr[j].p_offset + phdr[j].p_filesz)) { 508 shdr[i].sh_offset = 0; 509 shdr[i].sh_size = 0; 510 break; 511 } 512 } 513 if (shdr[i].sh_offset == 0 || shdr[i].sh_size == 0) 514 continue; /* alread loaded in a PT_LOAD above */ 515 /* Save it for loading below */ 516 symtabindex = i; 517 symstrindex = shdr[i].sh_link; 518 } 519 if (symtabindex < 0 || symstrindex < 0) 520 goto nosyms; 521 522 /* Ok, committed to a load. */ 523 #ifndef ELF_VERBOSE 524 printf("syms=["); 525 #endif 526 ssym = lastaddr; 527 for (i = symtabindex; i >= 0; i = symstrindex) { 528 #ifdef ELF_VERBOSE 529 char *secname; 530 531 switch(shdr[i].sh_type) { 532 case SHT_SYMTAB: /* Symbol table */ 533 secname = "symtab"; 534 break; 535 case SHT_STRTAB: /* String table */ 536 secname = "strtab"; 537 break; 538 default: 539 secname = "WHOA!!"; 540 break; 541 } 542 #endif 543 544 size = shdr[i].sh_size; 545 archsw.arch_copyin(&size, lastaddr, sizeof(size)); 546 lastaddr += sizeof(size); 547 548 #ifdef ELF_VERBOSE 549 printf("\n%s: 0x%jx@0x%jx -> 0x%jx-0x%jx", secname, 550 (uintmax_t)shdr[i].sh_size, (uintmax_t)shdr[i].sh_offset, 551 (uintmax_t)lastaddr, (uintmax_t)(lastaddr + shdr[i].sh_size)); 552 #else 553 if (i == symstrindex) 554 printf("+"); 555 printf("0x%lx+0x%lx", (long)sizeof(size), (long)size); 556 #endif 557 558 if (lseek(ef->fd, (off_t)shdr[i].sh_offset, SEEK_SET) == -1) { 559 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not seek for symbols - skipped!"); 560 lastaddr = ssym; 561 ssym = 0; 562 goto nosyms; 563 } 564 result = archsw.arch_readin(ef->fd, lastaddr, shdr[i].sh_size); 565 if (result < 0 || (size_t)result != shdr[i].sh_size) { 566 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not read symbols - skipped! (%ju != %ju)", (uintmax_t)result, 567 (uintmax_t)shdr[i].sh_size); 568 lastaddr = ssym; 569 ssym = 0; 570 goto nosyms; 571 } 572 /* Reset offsets relative to ssym */ 573 lastaddr += shdr[i].sh_size; 574 lastaddr = roundup(lastaddr, sizeof(size)); 575 if (i == symtabindex) 576 symtabindex = -1; 577 else if (i == symstrindex) 578 symstrindex = -1; 579 } 580 esym = lastaddr; 581 #ifndef ELF_VERBOSE 582 printf("]"); 583 #endif 584 585 file_addmetadata(fp, MODINFOMD_SSYM, sizeof(ssym), &ssym); 586 file_addmetadata(fp, MODINFOMD_ESYM, sizeof(esym), &esym); 587 588 nosyms: 589 printf("\n"); 590 591 ret = lastaddr - firstaddr; 592 fp->f_addr = firstaddr; 593 594 php = NULL; 595 for (i = 0; i < ehdr->e_phnum; i++) { 596 if (phdr[i].p_type == PT_DYNAMIC) { 597 php = phdr + i; 598 adp = php->p_vaddr; 599 file_addmetadata(fp, MODINFOMD_DYNAMIC, sizeof(adp), &adp); 600 break; 601 } 602 } 603 604 if (php == NULL) /* this is bad, we cannot get to symbols or _DYNAMIC */ 605 goto out; 606 607 ndp = php->p_filesz / sizeof(Elf_Dyn); 608 if (ndp == 0) 609 goto out; 610 dp = malloc(php->p_filesz); 611 if (dp == NULL) 612 goto out; 613 archsw.arch_copyout(php->p_vaddr + off, dp, php->p_filesz); 614 615 ef->strsz = 0; 616 for (i = 0; i < ndp; i++) { 617 if (dp[i].d_tag == 0) 618 break; 619 switch (dp[i].d_tag) { 620 case DT_HASH: 621 ef->hashtab = (Elf_Hashelt*)(uintptr_t)(dp[i].d_un.d_ptr + off); 622 break; 623 case DT_STRTAB: 624 ef->strtab = (char *)(uintptr_t)(dp[i].d_un.d_ptr + off); 625 break; 626 case DT_STRSZ: 627 ef->strsz = dp[i].d_un.d_val; 628 break; 629 case DT_SYMTAB: 630 ef->symtab = (Elf_Sym*)(uintptr_t)(dp[i].d_un.d_ptr + off); 631 break; 632 case DT_REL: 633 ef->rel = (Elf_Rel *)(uintptr_t)(dp[i].d_un.d_ptr + off); 634 break; 635 case DT_RELSZ: 636 ef->relsz = dp[i].d_un.d_val; 637 break; 638 case DT_RELA: 639 ef->rela = (Elf_Rela *)(uintptr_t)(dp[i].d_un.d_ptr + off); 640 break; 641 case DT_RELASZ: 642 ef->relasz = dp[i].d_un.d_val; 643 break; 644 default: 645 break; 646 } 647 } 648 if (ef->hashtab == NULL || ef->symtab == NULL || 649 ef->strtab == NULL || ef->strsz == 0) 650 goto out; 651 COPYOUT(ef->hashtab, &ef->nbuckets, sizeof(ef->nbuckets)); 652 COPYOUT(ef->hashtab + 1, &ef->nchains, sizeof(ef->nchains)); 653 ef->buckets = ef->hashtab + 2; 654 ef->chains = ef->buckets + ef->nbuckets; 655 656 if (__elfN(lookup_symbol)(fp, ef, "__start_set_modmetadata_set", &sym) != 0) 657 return 0; 658 p_start = sym.st_value + ef->off; 659 if (__elfN(lookup_symbol)(fp, ef, "__stop_set_modmetadata_set", &sym) != 0) 660 return ENOENT; 661 p_end = sym.st_value + ef->off; 662 663 if (__elfN(parse_modmetadata)(fp, ef, p_start, p_end) == 0) 664 goto out; 665 666 if (ef->kernel) /* kernel must not depend on anything */ 667 goto out; 668 669 out: 670 if (dp) 671 free(dp); 672 if (shdr) 673 free(shdr); 674 return ret; 675 } 676 677 static char invalid_name[] = "bad"; 678 679 char * 680 fake_modname(const char *name) 681 { 682 const char *sp, *ep; 683 char *fp; 684 size_t len; 685 686 sp = strrchr(name, '/'); 687 if (sp) 688 sp++; 689 else 690 sp = name; 691 ep = strrchr(name, '.'); 692 if (ep) { 693 if (ep == name) { 694 sp = invalid_name; 695 ep = invalid_name + sizeof(invalid_name) - 1; 696 } 697 } else 698 ep = name + strlen(name); 699 len = ep - sp; 700 fp = malloc(len + 1); 701 if (fp == NULL) 702 return NULL; 703 memcpy(fp, sp, len); 704 fp[len] = '\0'; 705 return fp; 706 } 707 708 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64 709 struct mod_metadata64 { 710 int md_version; /* structure version MDTV_* */ 711 int md_type; /* type of entry MDT_* */ 712 u_int64_t md_data; /* specific data */ 713 u_int64_t md_cval; /* common string label */ 714 }; 715 #endif 716 #if defined(__amd64__) && __ELF_WORD_SIZE == 32 717 struct mod_metadata32 { 718 int md_version; /* structure version MDTV_* */ 719 int md_type; /* type of entry MDT_* */ 720 u_int32_t md_data; /* specific data */ 721 u_int32_t md_cval; /* common string label */ 722 }; 723 #endif 724 725 int 726 __elfN(load_modmetadata)(struct preloaded_file *fp, u_int64_t dest) 727 { 728 struct elf_file ef; 729 int err, i, j; 730 Elf_Shdr *sh_meta, *shdr = NULL; 731 Elf_Shdr *sh_data[2]; 732 char *shstrtab = NULL; 733 size_t size; 734 Elf_Addr p_start, p_end; 735 736 bzero(&ef, sizeof(struct elf_file)); 737 ef.fd = -1; 738 739 err = __elfN(load_elf_header)(fp->f_name, &ef); 740 if (err != 0) 741 goto out; 742 743 if (ef.kernel == 1 || ef.ehdr->e_type == ET_EXEC) { 744 ef.kernel = 1; 745 } else if (ef.ehdr->e_type != ET_DYN) { 746 err = EFTYPE; 747 goto out; 748 } 749 750 size = ef.ehdr->e_shnum * ef.ehdr->e_shentsize; 751 shdr = alloc_pread(ef.fd, ef.ehdr->e_shoff, size); 752 if (shdr == NULL) { 753 err = ENOMEM; 754 goto out; 755 } 756 757 /* Load shstrtab. */ 758 shstrtab = alloc_pread(ef.fd, shdr[ef.ehdr->e_shstrndx].sh_offset, 759 shdr[ef.ehdr->e_shstrndx].sh_size); 760 if (shstrtab == NULL) { 761 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 762 "load_modmetadata: unable to load shstrtab\n"); 763 err = EFTYPE; 764 goto out; 765 } 766 767 /* Find set_modmetadata_set and data sections. */ 768 sh_data[0] = sh_data[1] = sh_meta = NULL; 769 for (i = 0, j = 0; i < ef.ehdr->e_shnum; i++) { 770 if (strcmp(&shstrtab[shdr[i].sh_name], 771 "set_modmetadata_set") == 0) { 772 sh_meta = &shdr[i]; 773 } 774 if ((strcmp(&shstrtab[shdr[i].sh_name], ".data") == 0) || 775 (strcmp(&shstrtab[shdr[i].sh_name], ".rodata") == 0)) { 776 sh_data[j++] = &shdr[i]; 777 } 778 } 779 if (sh_meta == NULL || sh_data[0] == NULL || sh_data[1] == NULL) { 780 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 781 "load_modmetadata: unable to find set_modmetadata_set or data sections\n"); 782 err = EFTYPE; 783 goto out; 784 } 785 786 /* Load set_modmetadata_set into memory */ 787 err = kern_pread(ef.fd, dest, sh_meta->sh_size, sh_meta->sh_offset); 788 if (err != 0) { 789 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 790 "load_modmetadata: unable to load set_modmetadata_set: %d\n", err); 791 goto out; 792 } 793 p_start = dest; 794 p_end = dest + sh_meta->sh_size; 795 dest += sh_meta->sh_size; 796 797 /* Load data sections into memory. */ 798 err = kern_pread(ef.fd, dest, sh_data[0]->sh_size, 799 sh_data[0]->sh_offset); 800 if (err != 0) { 801 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 802 "load_modmetadata: unable to load data: %d\n", err); 803 goto out; 804 } 805 806 /* 807 * We have to increment the dest, so that the offset is the same into 808 * both the .rodata and .data sections. 809 */ 810 ef.off = -(sh_data[0]->sh_addr - dest); 811 dest += (sh_data[1]->sh_addr - sh_data[0]->sh_addr); 812 813 err = kern_pread(ef.fd, dest, sh_data[1]->sh_size, 814 sh_data[1]->sh_offset); 815 if (err != 0) { 816 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 817 "load_modmetadata: unable to load data: %d\n", err); 818 goto out; 819 } 820 821 err = __elfN(parse_modmetadata)(fp, &ef, p_start, p_end); 822 if (err != 0) { 823 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 824 "load_modmetadata: unable to parse metadata: %d\n", err); 825 goto out; 826 } 827 828 out: 829 if (shstrtab != NULL) 830 free(shstrtab); 831 if (shdr != NULL) 832 free(shdr); 833 if (ef.firstpage != NULL) 834 free(ef.firstpage); 835 if (ef.fd != -1) 836 close(ef.fd); 837 return (err); 838 } 839 840 int 841 __elfN(parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef, 842 Elf_Addr p_start, Elf_Addr p_end) 843 { 844 struct mod_metadata md; 845 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64 846 struct mod_metadata64 md64; 847 #elif defined(__amd64__) && __ELF_WORD_SIZE == 32 848 struct mod_metadata32 md32; 849 #endif 850 struct mod_depend *mdepend; 851 struct mod_version mver; 852 char *s; 853 int error, modcnt, minfolen; 854 Elf_Addr v, p; 855 856 modcnt = 0; 857 p = p_start; 858 while (p < p_end) { 859 COPYOUT(p, &v, sizeof(v)); 860 error = __elfN(reloc_ptr)(fp, ef, p, &v, sizeof(v)); 861 if (error == EOPNOTSUPP) 862 v += ef->off; 863 else if (error != 0) 864 return (error); 865 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64 866 COPYOUT(v, &md64, sizeof(md64)); 867 error = __elfN(reloc_ptr)(fp, ef, v, &md64, sizeof(md64)); 868 if (error == EOPNOTSUPP) { 869 md64.md_cval += ef->off; 870 md64.md_data += ef->off; 871 } else if (error != 0) 872 return (error); 873 md.md_version = md64.md_version; 874 md.md_type = md64.md_type; 875 md.md_cval = (const char *)(uintptr_t)md64.md_cval; 876 md.md_data = (void *)(uintptr_t)md64.md_data; 877 #elif defined(__amd64__) && __ELF_WORD_SIZE == 32 878 COPYOUT(v, &md32, sizeof(md32)); 879 error = __elfN(reloc_ptr)(fp, ef, v, &md32, sizeof(md32)); 880 if (error == EOPNOTSUPP) { 881 md32.md_cval += ef->off; 882 md32.md_data += ef->off; 883 } else if (error != 0) 884 return (error); 885 md.md_version = md32.md_version; 886 md.md_type = md32.md_type; 887 md.md_cval = (const char *)(uintptr_t)md32.md_cval; 888 md.md_data = (void *)(uintptr_t)md32.md_data; 889 #else 890 COPYOUT(v, &md, sizeof(md)); 891 error = __elfN(reloc_ptr)(fp, ef, v, &md, sizeof(md)); 892 if (error == EOPNOTSUPP) { 893 md.md_cval += ef->off; 894 md.md_data = (void *)((uintptr_t)md.md_data + (uintptr_t)ef->off); 895 } else if (error != 0) 896 return (error); 897 #endif 898 p += sizeof(Elf_Addr); 899 switch(md.md_type) { 900 case MDT_DEPEND: 901 if (ef->kernel) /* kernel must not depend on anything */ 902 break; 903 s = strdupout((vm_offset_t)md.md_cval); 904 minfolen = sizeof(*mdepend) + strlen(s) + 1; 905 mdepend = malloc(minfolen); 906 if (mdepend == NULL) 907 return ENOMEM; 908 COPYOUT((vm_offset_t)md.md_data, mdepend, sizeof(*mdepend)); 909 strcpy((char*)(mdepend + 1), s); 910 free(s); 911 file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen, mdepend); 912 free(mdepend); 913 break; 914 case MDT_VERSION: 915 s = strdupout((vm_offset_t)md.md_cval); 916 COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver)); 917 file_addmodule(fp, s, mver.mv_version, NULL); 918 free(s); 919 modcnt++; 920 break; 921 } 922 } 923 if (modcnt == 0) { 924 s = fake_modname(fp->f_name); 925 file_addmodule(fp, s, 1, NULL); 926 free(s); 927 } 928 return 0; 929 } 930 931 static unsigned long 932 elf_hash(const char *name) 933 { 934 const unsigned char *p = (const unsigned char *) name; 935 unsigned long h = 0; 936 unsigned long g; 937 938 while (*p != '\0') { 939 h = (h << 4) + *p++; 940 if ((g = h & 0xf0000000) != 0) 941 h ^= g >> 24; 942 h &= ~g; 943 } 944 return h; 945 } 946 947 static const char __elfN(bad_symtable)[] = "elf" __XSTRING(__ELF_WORD_SIZE) "_lookup_symbol: corrupt symbol table\n"; 948 int 949 __elfN(lookup_symbol)(struct preloaded_file *fp, elf_file_t ef, const char* name, 950 Elf_Sym *symp) 951 { 952 Elf_Hashelt symnum; 953 Elf_Sym sym; 954 char *strp; 955 unsigned long hash; 956 957 hash = elf_hash(name); 958 COPYOUT(&ef->buckets[hash % ef->nbuckets], &symnum, sizeof(symnum)); 959 960 while (symnum != STN_UNDEF) { 961 if (symnum >= ef->nchains) { 962 printf(__elfN(bad_symtable)); 963 return ENOENT; 964 } 965 966 COPYOUT(ef->symtab + symnum, &sym, sizeof(sym)); 967 if (sym.st_name == 0) { 968 printf(__elfN(bad_symtable)); 969 return ENOENT; 970 } 971 972 strp = strdupout((vm_offset_t)(ef->strtab + sym.st_name)); 973 if (strcmp(name, strp) == 0) { 974 free(strp); 975 if (sym.st_shndx != SHN_UNDEF || 976 (sym.st_value != 0 && 977 ELF_ST_TYPE(sym.st_info) == STT_FUNC)) { 978 *symp = sym; 979 return 0; 980 } 981 return ENOENT; 982 } 983 free(strp); 984 COPYOUT(&ef->chains[symnum], &symnum, sizeof(symnum)); 985 } 986 return ENOENT; 987 } 988 989 /* 990 * Apply any intra-module relocations to the value. p is the load address 991 * of the value and val/len is the value to be modified. This does NOT modify 992 * the image in-place, because this is done by kern_linker later on. 993 * 994 * Returns EOPNOTSUPP if no relocation method is supplied. 995 */ 996 static int 997 __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, 998 Elf_Addr p, void *val, size_t len) 999 { 1000 size_t n; 1001 Elf_Rela a; 1002 Elf_Rel r; 1003 int error; 1004 1005 /* 1006 * The kernel is already relocated, but we still want to apply 1007 * offset adjustments. 1008 */ 1009 if (ef->kernel) 1010 return (EOPNOTSUPP); 1011 1012 for (n = 0; n < ef->relsz / sizeof(r); n++) { 1013 COPYOUT(ef->rel + n, &r, sizeof(r)); 1014 1015 error = __elfN(reloc)(ef, __elfN(symaddr), &r, ELF_RELOC_REL, 1016 ef->off, p, val, len); 1017 if (error != 0) 1018 return (error); 1019 } 1020 for (n = 0; n < ef->relasz / sizeof(a); n++) { 1021 COPYOUT(ef->rela + n, &a, sizeof(a)); 1022 1023 error = __elfN(reloc)(ef, __elfN(symaddr), &a, ELF_RELOC_RELA, 1024 ef->off, p, val, len); 1025 if (error != 0) 1026 return (error); 1027 } 1028 1029 return (0); 1030 } 1031 1032 static Elf_Addr 1033 __elfN(symaddr)(struct elf_file *ef, Elf_Size symidx) 1034 { 1035 1036 /* Symbol lookup by index not required here. */ 1037 return (0); 1038 } 1039