sys/boot/common/load_elf.c

   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  * $FreeBSD: src/sys/boot/common/load_elf.c,v 1.39 2008/10/14 10:11:14 raj Exp $
  28  */
  29
  30 #include <sys/param.h>
  31 #include <sys/exec.h>
  32 #include <sys/linker.h>
  33 #include <sys/module.h>
  34 #include <sys/stdint.h>
  35 #include <string.h>
  36 #include <machine/elf.h>
  37 #include <stand.h>
  38 #define FREEBSD_ELF
  39 #include <link.h>
  40
  41 #include "bootstrap.h"
  42
  43 #define COPYOUT(s,d,l)  archsw.arch_copyout((vm_offset_t)(s), d, l)
  44
  45 #if defined(__i386__) && __ELF_WORD_SIZE == 64
  46 #undef ELF_TARG_CLASS
  47 #undef ELF_TARG_MACH
  48 #define ELF_TARG_CLASS  ELFCLASS64
  49 #define ELF_TARG_MACH   EM_X86_64
  50 #endif
  51
  52 typedef struct elf_file {
  53     Elf_Phdr    *ph;
  54     Elf_Ehdr    *ehdr;
  55     Elf_Sym     *symtab;
  56     Elf_Hashelt *hashtab;
  57     Elf_Hashelt nbuckets;
  58     Elf_Hashelt nchains;
  59     Elf_Hashelt *buckets;
  60     Elf_Hashelt *chains;
  61     Elf_Rel     *rel;
  62     size_t      relsz;
  63     Elf_Rela    *rela;
  64     size_t      relasz;
  65     char        *strtab;
  66     size_t      strsz;
  67     int         fd;
  68     caddr_t     firstpage;
  69     size_t      firstlen;
  70     int         kernel;
  71     u_int64_t   off;
  72 } *elf_file_t;
  73
  74 static int __elfN(loadimage)(struct preloaded_file *mp, elf_file_t ef, u_int64_t loadaddr);
  75 static int __elfN(lookup_symbol)(struct preloaded_file *mp, elf_file_t ef, const char* name, Elf_Sym* sym);
  76 static int __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
  77     Elf_Addr p, void *val, size_t len);
  78 static int __elfN(parse_modmetadata)(struct preloaded_file *mp, elf_file_t ef);
  79 static symaddr_fn __elfN(symaddr);
  80 static char     *fake_modname(const char *name);
  81
  82 const char      *__elfN(kerneltype) = "elf kernel";
  83 const char      *__elfN(moduletype) = "elf module";
  84
  85 u_int64_t       __elfN(relocation_offset) = 0;
  86
  87 /*
  88  * Attempt to load the file (file) as an ELF module.  It will be stored at
  89  * (dest), and a pointer to a module structure describing the loaded object
  90  * will be saved in (result).
  91  */
  92 int
  93 __elfN(loadfile)(char *filename, u_int64_t dest, struct preloaded_file **result)
  94 {
  95     struct preloaded_file       *fp, *kfp;
  96     struct elf_file             ef;
  97     Elf_Ehdr                    *ehdr;
  98     int                         err;
  99     u_int                       pad;
 100     ssize_t                     bytes_read;
 101
 102     fp = NULL;
 103     bzero(&ef, sizeof(struct elf_file));
 104
 105     /*
 106      * Open the image, read and validate the ELF header
 107      */
 108     if (filename == NULL)       /* can't handle nameless */
 109         return(EFTYPE);
 110     if ((ef.fd = rel_open(filename, O_RDONLY)) == -1)
 111         return(errno);
 112     ef.firstpage = malloc(PAGE_SIZE);
 113     if (ef.firstpage == NULL) {
 114         close(ef.fd);
 115         return(ENOMEM);
 116     }
 117     bytes_read = read(ef.fd, ef.firstpage, PAGE_SIZE);
 118     ef.firstlen = (size_t)bytes_read;
 119     if (bytes_read < 0 || ef.firstlen <= sizeof(Elf_Ehdr)) {
 120         err = EFTYPE;           /* could be EIO, but may be small file */
 121         goto oerr;
 122     }
 123     ehdr = ef.ehdr = (Elf_Ehdr *)ef.firstpage;
 124
 125     /* Is it ELF? */
 126     if (!IS_ELF(*ehdr)) {
 127         err = EFTYPE;
 128         goto oerr;
 129     }
 130     if (ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||    /* Layout ? */
 131         ehdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
 132         ehdr->e_ident[EI_VERSION] != EV_CURRENT ||      /* Version ? */
 133         ehdr->e_version != EV_CURRENT ||
 134         ehdr->e_machine != ELF_TARG_MACH) {             /* Machine ? */
 135         err = EFTYPE;
 136         goto oerr;
 137     }
 138
 139
 140     /*
 141      * Check to see what sort of module we are.
 142      */
 143     kfp = file_findfile(NULL, NULL);
 144     if (ehdr->e_type == ET_DYN) {
 145         /* Looks like a kld module */
 146         if (kfp == NULL) {
 147             printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module before kernel\n");
 148             err = EPERM;
 149             goto oerr;
 150         }
 151         if (strcmp(__elfN(kerneltype), kfp->f_type)) {
 152             printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module with kernel type '%s'\n", kfp->f_type);
 153             err = EPERM;
 154             goto oerr;
 155         }
 156         /* Looks OK, got ahead */
 157         ef.kernel = 0;
 158
 159         /* Page-align the load address */
 160         pad = (u_int)dest & PAGE_MASK;
 161         if (pad != 0) {
 162             pad = PAGE_SIZE - pad;
 163             dest += pad;
 164         }
 165     } else if (ehdr->e_type == ET_EXEC) {
 166         /* Looks like a kernel */
 167         if (kfp != NULL) {
 168             printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: kernel already loaded\n");
 169             err = EPERM;
 170             goto oerr;
 171         }
 172         /*
 173          * Calculate destination address based on kernel entrypoint
 174          */
 175         dest = ehdr->e_entry;
 176         if (dest == 0) {
 177             printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: not a kernel (maybe static binary?)\n");
 178             err = EPERM;
 179             goto oerr;
 180         }
 181         ef.kernel = 1;
 182
 183     } else {
 184         err = EFTYPE;
 185         goto oerr;
 186     }
 187
 188     /*
 189      * Ok, we think we should handle this.
 190      */
 191     fp = file_alloc();
 192     if (fp == NULL) {
 193             printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: cannot allocate module info\n");
 194             err = EPERM;
 195             goto out;
 196     }
 197     if (ef.kernel)
 198         setenv("kernelname", filename, 1);
 199     fp->f_name = strdup(filename);
 200     fp->f_type = strdup(ef.kernel ? __elfN(kerneltype) : __elfN(moduletype));
 201
 202 #ifdef ELF_VERBOSE
 203     if (ef.kernel)
 204         printf("%s entry at 0x%jx\n", filename, (uintmax_t)dest);
 205 #else
 206     printf("%s ", filename);
 207 #endif
 208
 209     fp->f_size = __elfN(loadimage)(fp, &ef, dest);
 210     if (fp->f_size == 0 || fp->f_addr == 0)
 211         goto ioerr;
 212
 213     /* save exec header as metadata */
 214     file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*ehdr), ehdr);
 215
 216     /* Load OK, return module pointer */
 217     *result = (struct preloaded_file *)fp;
 218     err = 0;
 219     goto out;
 220
 221  ioerr:
 222     err = EIO;
 223  oerr:
 224     file_discard(fp);
 225  out:
 226     if (ef.firstpage)
 227         free(ef.firstpage);
 228     close(ef.fd);
 229     return(err);
 230 }
 231
 232 /*
 233  * With the file (fd) open on the image, and (ehdr) containing
 234  * the Elf header, load the image at (off)
 235  */
 236 static int
 237 __elfN(loadimage)(struct preloaded_file *fp, elf_file_t ef, u_int64_t off)
 238 {
 239     int         i;
 240     u_int       j;
 241     Elf_Ehdr    *ehdr;
 242     Elf_Phdr    *phdr, *php;
 243     Elf_Shdr    *shdr;
 244     int         ret;
 245     vm_offset_t firstaddr;
 246     vm_offset_t lastaddr;
 247     size_t      chunk;
 248     ssize_t     result;
 249     Elf_Addr    ssym, esym;
 250     Elf_Dyn     *dp;
 251     Elf_Addr    adp;
 252     int         ndp;
 253     int         symstrindex;
 254     int         symtabindex;
 255     Elf_Size    size;
 256     u_int       fpcopy;
 257
 258     dp = NULL;
 259     shdr = NULL;
 260     ret = 0;
 261     firstaddr = lastaddr = 0;
 262     ehdr = ef->ehdr;
 263     if (ef->kernel) {
 264 #ifdef __i386__
 265 #if __ELF_WORD_SIZE == 64
 266         off = - (off & 0xffffffffff000000ull);/* x86_64 relocates after locore */
 267 #else
 268         off = - (off & 0xff000000u);    /* i386 relocates after locore */
 269 #endif
 270 #elif defined(__powerpc__)
 271         /*
 272          * On the purely virtual memory machines like e500, the kernel is
 273          * linked against its final VA range, which is most often not
 274          * available at the loader stage, but only after kernel initializes
 275          * and completes its VM settings. In such cases we cannot use p_vaddr
 276          * field directly to load ELF segments, but put them at some
 277          * 'load-time' locations.
 278          */
 279         if (off & 0xf0000000u) {
 280             off = -(off & 0xf0000000u);
 281             /*
 282              * XXX the physical load address should not be hardcoded. Note
 283              * that the Book-E kernel assumes that it's loaded at a 16MB
 284              * boundary for now...
 285              */
 286             off += 0x01000000;
 287             ehdr->e_entry += off;
 288 #ifdef ELF_VERBOSE
 289             printf("Converted entry 0x%08x\n", ehdr->e_entry);
 290 #endif
 291         } else
 292             off = 0;
 293 #elif defined(__arm__)
 294         if (off & 0xf0000000u) {
 295             off = -(off & 0xf0000000u);
 296             ehdr->e_entry += off;
 297 #ifdef ELF_VERBOSE
 298             printf("Converted entry 0x%08x\n", ehdr->e_entry);
 299 #endif
 300         } else
 301             off = 0;
 302 #else
 303         off = 0;                /* other archs use direct mapped kernels */
 304 #endif
 305         __elfN(relocation_offset) = off;
 306     }
 307     ef->off = off;
 308
 309     if ((ehdr->e_phoff + ehdr->e_phnum * sizeof(*phdr)) > ef->firstlen) {
 310         printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: program header not within first page\n");
 311         goto out;
 312     }
 313     phdr = (Elf_Phdr *)(ef->firstpage + ehdr->e_phoff);
 314
 315     for (i = 0; i < ehdr->e_phnum; i++) {
 316         /* We want to load PT_LOAD segments only.. */
 317         if (phdr[i].p_type != PT_LOAD)
 318             continue;
 319
 320 #ifdef ELF_VERBOSE
 321         printf("Segment: 0x%lx@0x%lx -> 0x%lx-0x%lx",
 322             (long)phdr[i].p_filesz, (long)phdr[i].p_offset,
 323             (long)(phdr[i].p_vaddr + off),
 324             (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1));
 325 #else
 326         if ((phdr[i].p_flags & PF_W) == 0) {
 327             printf("text=0x%lx ", (long)phdr[i].p_filesz);
 328         } else {
 329             printf("data=0x%lx", (long)phdr[i].p_filesz);
 330             if (phdr[i].p_filesz < phdr[i].p_memsz)
 331                 printf("+0x%lx", (long)(phdr[i].p_memsz -phdr[i].p_filesz));
 332             printf(" ");
 333         }
 334 #endif
 335         fpcopy = 0;
 336         if (ef->firstlen > phdr[i].p_offset) {
 337             fpcopy = ef->firstlen - phdr[i].p_offset;
 338             archsw.arch_copyin(ef->firstpage + phdr[i].p_offset,
 339                                phdr[i].p_vaddr + off, fpcopy);
 340         }
 341         if (phdr[i].p_filesz > fpcopy) {
 342             if (kern_pread(ef->fd, phdr[i].p_vaddr + off + fpcopy,
 343                 phdr[i].p_filesz - fpcopy, phdr[i].p_offset + fpcopy) != 0) {
 344                 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
 345                     "_loadimage: read failed\n");
 346                 goto out;
 347             }
 348         }
 349         /* clear space from oversized segments; eg: bss */
 350         if (phdr[i].p_filesz < phdr[i].p_memsz) {
 351 #ifdef ELF_VERBOSE
 352             printf(" (bss: 0x%lx-0x%lx)",
 353                 (long)(phdr[i].p_vaddr + off + phdr[i].p_filesz),
 354                 (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1));
 355 #endif
 356
 357             kern_bzero(phdr[i].p_vaddr + off + phdr[i].p_filesz,
 358                 phdr[i].p_memsz - phdr[i].p_filesz);
 359         }
 360 #ifdef ELF_VERBOSE
 361         printf("\n");
 362 #endif
 363
 364         if (firstaddr == 0 || firstaddr > (phdr[i].p_vaddr + off))
 365             firstaddr = phdr[i].p_vaddr + off;
 366         if (lastaddr == 0 || lastaddr < (phdr[i].p_vaddr + off + phdr[i].p_memsz))
 367             lastaddr = phdr[i].p_vaddr + off + phdr[i].p_memsz;
 368     }
 369     lastaddr = roundup(lastaddr, sizeof(long));
 370
 371     /*
 372      * Now grab the symbol tables.  This isn't easy if we're reading a
 373      * .gz file.  I think the rule is going to have to be that you must
 374      * strip a file to remove symbols before gzipping it so that we do not
 375      * try to lseek() on it.
 376      */
 377     chunk = ehdr->e_shnum * ehdr->e_shentsize;
 378     if (chunk == 0 || ehdr->e_shoff == 0)
 379         goto nosyms;
 380     shdr = alloc_pread(ef->fd, ehdr->e_shoff, chunk);
 381     if (shdr == NULL) {
 382         printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
 383             "_loadimage: failed to read section headers");
 384         goto nosyms;
 385     }
 386     symtabindex = -1;
 387     symstrindex = -1;
 388     for (i = 0; i < ehdr->e_shnum; i++) {
 389         if (shdr[i].sh_type != SHT_SYMTAB)
 390             continue;
 391         for (j = 0; j < ehdr->e_phnum; j++) {
 392             if (phdr[j].p_type != PT_LOAD)
 393                 continue;
 394             if (shdr[i].sh_offset >= phdr[j].p_offset &&
 395                 (shdr[i].sh_offset + shdr[i].sh_size <=
 396                  phdr[j].p_offset + phdr[j].p_filesz)) {
 397                 shdr[i].sh_offset = 0;
 398                 shdr[i].sh_size = 0;
 399                 break;
 400             }
 401         }
 402         if (shdr[i].sh_offset == 0 || shdr[i].sh_size == 0)
 403             continue;           /* alread loaded in a PT_LOAD above */
 404         /* Save it for loading below */
 405         symtabindex = i;
 406         symstrindex = shdr[i].sh_link;
 407     }
 408     if (symtabindex < 0 || symstrindex < 0)
 409         goto nosyms;
 410
 411     /* Ok, committed to a load. */
 412 #ifndef ELF_VERBOSE
 413     printf("syms=[");
 414 #endif
 415     ssym = lastaddr;
 416     for (i = symtabindex; i >= 0; i = symstrindex) {
 417 #ifdef ELF_VERBOSE
 418         char    *secname;
 419
 420         switch(shdr[i].sh_type) {
 421             case SHT_SYMTAB:            /* Symbol table */
 422                 secname = "symtab";
 423                 break;
 424             case SHT_STRTAB:            /* String table */
 425                 secname = "strtab";
 426                 break;
 427             default:
 428                 secname = "WHOA!!";
 429                 break;
 430         }
 431 #endif
 432
 433         size = shdr[i].sh_size;
 434         archsw.arch_copyin(&size, lastaddr, sizeof(size));
 435         lastaddr += sizeof(size);
 436
 437 #ifdef ELF_VERBOSE
 438         printf("\n%s: 0x%jx@0x%jx -> 0x%jx-0x%jx", secname,
 439             (uintmax_t)shdr[i].sh_size, (uintmax_t)shdr[i].sh_offset,
 440             (uintmax_t)lastaddr, (uintmax_t)(lastaddr + shdr[i].sh_size));
 441 #else
 442         if (i == symstrindex)
 443             printf("+");
 444         printf("0x%lx+0x%lx", (long)sizeof(size), (long)size);
 445 #endif
 446
 447         if (lseek(ef->fd, (off_t)shdr[i].sh_offset, SEEK_SET) == -1) {
 448             printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not seek for symbols - skipped!");
 449             lastaddr = ssym;
 450             ssym = 0;
 451             goto nosyms;
 452         }
 453         result = archsw.arch_readin(ef->fd, lastaddr, shdr[i].sh_size);
 454         if (result < 0 || (size_t)result != shdr[i].sh_size) {
 455             printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not read symbols - skipped!");
 456             lastaddr = ssym;
 457             ssym = 0;
 458             goto nosyms;
 459         }
 460         /* Reset offsets relative to ssym */
 461         lastaddr += shdr[i].sh_size;
 462         lastaddr = roundup(lastaddr, sizeof(size));
 463         if (i == symtabindex)
 464             symtabindex = -1;
 465         else if (i == symstrindex)
 466             symstrindex = -1;
 467     }
 468     esym = lastaddr;
 469 #ifndef ELF_VERBOSE
 470     printf("]");
 471 #endif
 472
 473     file_addmetadata(fp, MODINFOMD_SSYM, sizeof(ssym), &ssym);
 474     file_addmetadata(fp, MODINFOMD_ESYM, sizeof(esym), &esym);
 475
 476 nosyms:
 477     printf("\n");
 478
 479     ret = lastaddr - firstaddr;
 480     fp->f_addr = firstaddr;
 481
 482     php = NULL;
 483     for (i = 0; i < ehdr->e_phnum; i++) {
 484         if (phdr[i].p_type == PT_DYNAMIC) {
 485             php = phdr + i;
 486             adp = php->p_vaddr;
 487             file_addmetadata(fp, MODINFOMD_DYNAMIC, sizeof(adp), &adp);
 488             break;
 489         }
 490     }
 491
 492     if (php == NULL)    /* this is bad, we cannot get to symbols or _DYNAMIC */
 493         goto out;
 494
 495     ndp = php->p_filesz / sizeof(Elf_Dyn);
 496     if (ndp == 0)
 497         goto out;
 498     dp = malloc(php->p_filesz);
 499     if (dp == NULL)
 500         goto out;
 501     archsw.arch_copyout(php->p_vaddr + off, dp, php->p_filesz);
 502
 503     ef->strsz = 0;
 504     for (i = 0; i < ndp; i++) {
 505         if (dp[i].d_tag == 0)
 506             break;
 507         switch (dp[i].d_tag) {
 508         case DT_HASH:
 509             ef->hashtab = (Elf_Hashelt*)(uintptr_t)(dp[i].d_un.d_ptr + off);
 510             break;
 511         case DT_STRTAB:
 512             ef->strtab = (char *)(uintptr_t)(dp[i].d_un.d_ptr + off);
 513             break;
 514         case DT_STRSZ:
 515             ef->strsz = dp[i].d_un.d_val;
 516             break;
 517         case DT_SYMTAB:
 518             ef->symtab = (Elf_Sym*)(uintptr_t)(dp[i].d_un.d_ptr + off);
 519             break;
 520         case DT_REL:
 521             ef->rel = (Elf_Rel *)(uintptr_t)(dp[i].d_un.d_ptr + off);
 522             break;
 523         case DT_RELSZ:
 524             ef->relsz = dp[i].d_un.d_val;
 525             break;
 526         case DT_RELA:
 527             ef->rela = (Elf_Rela *)(uintptr_t)(dp[i].d_un.d_ptr + off);
 528             break;
 529         case DT_RELASZ:
 530             ef->relasz = dp[i].d_un.d_val;
 531             break;
 532         default:
 533             break;
 534         }
 535     }
 536     if (ef->hashtab == NULL || ef->symtab == NULL ||
 537         ef->strtab == NULL || ef->strsz == 0)
 538         goto out;
 539     COPYOUT(ef->hashtab, &ef->nbuckets, sizeof(ef->nbuckets));
 540     COPYOUT(ef->hashtab + 1, &ef->nchains, sizeof(ef->nchains));
 541     ef->buckets = ef->hashtab + 2;
 542     ef->chains = ef->buckets + ef->nbuckets;
 543     if (__elfN(parse_modmetadata)(fp, ef) == 0)
 544         goto out;
 545
 546     if (ef->kernel)                     /* kernel must not depend on anything */
 547         goto out;
 548
 549 out:
 550     if (dp)
 551         free(dp);
 552     if (shdr)
 553         free(shdr);
 554     return ret;
 555 }
 556
 557 static char invalid_name[] = "bad";
 558
 559 char *
 560 fake_modname(const char *name)
 561 {
 562     const char *sp, *ep;
 563     char *fp;
 564     size_t len;
 565
 566     sp = strrchr(name, '/');
 567     if (sp)
 568         sp++;
 569     else
 570         sp = name;
 571     ep = strrchr(name, '.');
 572     if (ep) {
 573             if (ep == name) {
 574                 sp = invalid_name;
 575                 ep = invalid_name + sizeof(invalid_name) - 1;
 576             }
 577     } else
 578         ep = name + strlen(name);
 579     len = ep - sp;
 580     fp = malloc(len + 1);
 581     if (fp == NULL)
 582         return NULL;
 583     memcpy(fp, sp, len);
 584     fp[len] = '\0';
 585     return fp;
 586 }
 587
 588 #if defined(__i386__) && __ELF_WORD_SIZE == 64
 589 struct mod_metadata64 {
 590         int             md_version;     /* structure version MDTV_* */
 591         int             md_type;        /* type of entry MDT_* */
 592         u_int64_t       md_data;        /* specific data */
 593         u_int64_t       md_cval;        /* common string label */
 594 };
 595 #endif
 596
 597 int
 598 __elfN(parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef)
 599 {
 600     struct mod_metadata md;
 601 #if defined(__i386__) && __ELF_WORD_SIZE == 64
 602     struct mod_metadata64 md64;
 603 #endif
 604     struct mod_depend *mdepend;
 605     struct mod_version mver;
 606     Elf_Sym sym;
 607     char *s;
 608     int error, modcnt, minfolen;
 609     Elf_Addr v, p, p_stop;
 610
 611     if (__elfN(lookup_symbol)(fp, ef, "__start_set_modmetadata_set", &sym) != 0)
 612         return ENOENT;
 613     p = sym.st_value + ef->off;
 614     if (__elfN(lookup_symbol)(fp, ef, "__stop_set_modmetadata_set", &sym) != 0)
 615         return ENOENT;
 616     p_stop = sym.st_value + ef->off;
 617
 618     modcnt = 0;
 619     while (p < p_stop) {
 620         COPYOUT(p, &v, sizeof(v));
 621         error = __elfN(reloc_ptr)(fp, ef, p, &v, sizeof(v));
 622         if (error == EOPNOTSUPP)
 623             v += ef->off;
 624         else if (error != 0)
 625             return (error);
 626 #if defined(__i386__) && __ELF_WORD_SIZE == 64
 627         COPYOUT(v, &md64, sizeof(md64));
 628         error = __elfN(reloc_ptr)(fp, ef, v, &md64, sizeof(md64));
 629         if (error == EOPNOTSUPP) {
 630             md64.md_cval += ef->off;
 631             md64.md_data += ef->off;
 632         } else if (error != 0)
 633             return (error);
 634         md.md_version = md64.md_version;
 635         md.md_type = md64.md_type;
 636         md.md_cval = (const char *)(uintptr_t)md64.md_cval;
 637         md.md_data = (void *)(uintptr_t)md64.md_data;
 638 #else
 639         COPYOUT(v, &md, sizeof(md));
 640         error = __elfN(reloc_ptr)(fp, ef, v, &md, sizeof(md));
 641         if (error == EOPNOTSUPP) {
 642             md.md_cval += ef->off;
 643             md.md_data += ef->off;
 644         } else if (error != 0)
 645             return (error);
 646 #endif
 647         p += sizeof(Elf_Addr);
 648         switch(md.md_type) {
 649           case MDT_DEPEND:
 650             if (ef->kernel)             /* kernel must not depend on anything */
 651               break;
 652             s = strdupout((vm_offset_t)md.md_cval);
 653             minfolen = sizeof(*mdepend) + strlen(s) + 1;
 654             mdepend = malloc(minfolen);
 655             if (mdepend == NULL)
 656                 return ENOMEM;
 657             COPYOUT((vm_offset_t)md.md_data, mdepend, sizeof(*mdepend));
 658             strcpy((char*)(mdepend + 1), s);
 659             free(s);
 660             file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen, mdepend);
 661             free(mdepend);
 662             break;
 663           case MDT_VERSION:
 664             s = strdupout((vm_offset_t)md.md_cval);
 665             COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver));
 666             file_addmodule(fp, s, mver.mv_version, NULL);
 667             free(s);
 668             modcnt++;
 669             break;
 670         }
 671     }
 672     if (modcnt == 0) {
 673         s = fake_modname(fp->f_name);
 674         file_addmodule(fp, s, 1, NULL);
 675         free(s);
 676     }
 677     return 0;
 678 }
 679
 680 static unsigned long
 681 elf_hash(const char *name)
 682 {
 683     const unsigned char *p = (const unsigned char *) name;
 684     unsigned long h = 0;
 685     unsigned long g;
 686
 687     while (*p != '\0') {
 688         h = (h << 4) + *p++;
 689         if ((g = h & 0xf0000000) != 0)
 690             h ^= g >> 24;
 691         h &= ~g;
 692     }
 693     return h;
 694 }
 695
 696 static const char __elfN(bad_symtable)[] = "elf" __XSTRING(__ELF_WORD_SIZE) "_lookup_symbol: corrupt symbol table\n";
 697 int
 698 __elfN(lookup_symbol)(struct preloaded_file *fp, elf_file_t ef, const char* name,
 699                   Elf_Sym *symp)
 700 {
 701     Elf_Hashelt symnum;
 702     Elf_Sym sym;
 703     char *strp;
 704     unsigned long hash;
 705
 706     hash = elf_hash(name);
 707     COPYOUT(&ef->buckets[hash % ef->nbuckets], &symnum, sizeof(symnum));
 708
 709     while (symnum != STN_UNDEF) {
 710         if (symnum >= ef->nchains) {
 711             printf(__elfN(bad_symtable));
 712             return ENOENT;
 713         }
 714
 715         COPYOUT(ef->symtab + symnum, &sym, sizeof(sym));
 716         if (sym.st_name == 0) {
 717             printf(__elfN(bad_symtable));
 718             return ENOENT;
 719         }
 720
 721         strp = strdupout((vm_offset_t)(ef->strtab + sym.st_name));
 722         if (strcmp(name, strp) == 0) {
 723             free(strp);
 724             if (sym.st_shndx != SHN_UNDEF ||
 725                 (sym.st_value != 0 &&
 726                  ELF_ST_TYPE(sym.st_info) == STT_FUNC)) {
 727                 *symp = sym;
 728                 return 0;
 729             }
 730             return ENOENT;
 731         }
 732         free(strp);
 733         COPYOUT(&ef->chains[symnum], &symnum, sizeof(symnum));
 734     }
 735     return ENOENT;
 736 }
 737
 738 /*
 739  * Apply any intra-module relocations to the value. p is the load address
 740  * of the value and val/len is the value to be modified. This does NOT modify
 741  * the image in-place, because this is done by kern_linker later on.
 742  *
 743  * Returns EOPNOTSUPP if no relocation method is supplied.
 744  */
 745 static int
 746 __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
 747     Elf_Addr p, void *val, size_t len)
 748 {
 749         size_t n;
 750         Elf_Rela a;
 751         Elf_Rel r;
 752         int error;
 753
 754         /*
 755          * The kernel is already relocated, but we still want to apply
 756          * offset adjustments.
 757          */
 758         if (ef->kernel)
 759                 return (EOPNOTSUPP);
 760
 761         for (n = 0; n < ef->relsz / sizeof(r); n++) {
 762                 COPYOUT(ef->rel + n, &r, sizeof(r));
 763
 764                 error = __elfN(reloc)(ef, __elfN(symaddr), &r, ELF_RELOC_REL,
 765                     ef->off, p, val, len);
 766                 if (error != 0)
 767                         return (error);
 768         }
 769         for (n = 0; n < ef->relasz / sizeof(a); n++) {
 770                 COPYOUT(ef->rela + n, &a, sizeof(a));
 771
 772                 error = __elfN(reloc)(ef, __elfN(symaddr), &a, ELF_RELOC_RELA,
 773                     ef->off, p, val, len);
 774                 if (error != 0)
 775                         return (error);
 776         }
 777
 778         return (0);
 779 }
 780
 781 static Elf_Addr
 782 __elfN(symaddr)(struct elf_file *ef, Elf_Size symidx)
 783 {
 784
 785         /* Symbol lookup by index not required here. */
 786         return (0);
 787 }