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 1.29 2003/08/25 23:30:41 obrien Exp $
  28  * $DragonFly: src/sys/boot/common/load_elf.c,v 1.6 2007/11/25 18:10:07 swildner Exp $
  29  */
  30
  31 #include <sys/param.h>
  32 #include <sys/exec.h>
  33 #include <sys/linker.h>
  34 #include <sys/module.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_Rela    *rela;
  62     size_t      relasz;
  63     char        *strtab;
  64     size_t      strsz;
  65     int         fd;
  66     caddr_t     firstpage;
  67     size_t      firstlen;
  68     int         kernel;
  69     u_int64_t   off;
  70 } *elf_file_t;
  71
  72 static int __elfN(loadimage)(struct preloaded_file *mp, elf_file_t ef, u_int64_t loadaddr);
  73 static int __elfN(lookup_symbol)(struct preloaded_file *mp, elf_file_t ef, const char* name, Elf_Sym* sym);
  74 #ifdef __sparc__
  75 static void __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
  76     void *p, void *val, size_t len);
  77 #endif
  78 static int __elfN(parse_modmetadata)(struct preloaded_file *mp, elf_file_t ef);
  79 static char     *fake_modname(const char *name);
  80
  81 const char      *__elfN(kerneltype) = "elf kernel";
  82 const char      *__elfN(moduletype) = "elf module";
  83
  84 /*
  85  * Attempt to load the file (file) as an ELF module.  It will be stored at
  86  * (dest), and a pointer to a module structure describing the loaded object
  87  * will be saved in (result).
  88  */
  89 int
  90 __elfN(loadfile)(char *filename, u_int64_t dest, struct preloaded_file **result)
  91 {
  92     struct preloaded_file       *fp, *kfp;
  93     struct elf_file             ef;
  94     Elf_Ehdr                    *ehdr;
  95     int                         err;
  96     u_int                       pad;
  97     ssize_t                     bytes_read;
  98
  99     fp = NULL;
 100     bzero(&ef, sizeof(struct elf_file));
 101
 102     /*
 103      * Open the image, read and validate the ELF header
 104      */
 105     if (filename == NULL)       /* can't handle nameless */
 106         return(EFTYPE);
 107     if ((ef.fd = open(filename, O_RDONLY)) == -1)
 108         return(errno);
 109     ef.firstpage = malloc(PAGE_SIZE);
 110     if (ef.firstpage == NULL) {
 111         close(ef.fd);
 112         return(ENOMEM);
 113     }
 114     bytes_read = read(ef.fd, ef.firstpage, PAGE_SIZE);
 115     ef.firstlen = (size_t)bytes_read;
 116     if (bytes_read < 0 || ef.firstlen <= sizeof(Elf_Ehdr)) {
 117         err = EFTYPE;           /* could be EIO, but may be small file */
 118         goto oerr;
 119     }
 120     ehdr = ef.ehdr = (Elf_Ehdr *)ef.firstpage;
 121
 122     /* Is it ELF? */
 123     if (!IS_ELF(*ehdr)) {
 124         err = EFTYPE;
 125         goto oerr;
 126     }
 127     if (ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||    /* Layout ? */
 128         ehdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
 129         ehdr->e_ident[EI_VERSION] != EV_CURRENT ||      /* Version ? */
 130         ehdr->e_version != EV_CURRENT ||
 131         ehdr->e_machine != ELF_TARG_MACH) {             /* Machine ? */
 132         err = EFTYPE;
 133         goto oerr;
 134     }
 135
 136
 137     /*
 138      * Check to see what sort of module we are.
 139      */
 140     kfp = file_findfile(NULL, NULL);
 141     if (ehdr->e_type == ET_DYN) {
 142         /* Looks like a kld module */
 143         if (kfp == NULL) {
 144             printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module before kernel\n");
 145             err = EPERM;
 146             goto oerr;
 147         }
 148         if (strcmp(__elfN(kerneltype), kfp->f_type)) {
 149             printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module with kernel type '%s'\n", kfp->f_type);
 150             err = EPERM;
 151             goto oerr;
 152         }
 153         /* Looks OK, got ahead */
 154         ef.kernel = 0;
 155
 156         /* Page-align the load address */
 157         pad = (u_int)dest & PAGE_MASK;
 158         if (pad != 0) {
 159             pad = PAGE_SIZE - pad;
 160             dest += pad;
 161         }
 162     } else if (ehdr->e_type == ET_EXEC) {
 163         /* Looks like a kernel */
 164         if (kfp != NULL) {
 165             printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: kernel already loaded\n");
 166             err = EPERM;
 167             goto oerr;
 168         }
 169         /*
 170          * Calculate destination address based on kernel entrypoint
 171          */
 172         dest = ehdr->e_entry;
 173         if (dest == 0) {
 174             printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: not a kernel (maybe static binary?)\n");
 175             err = EPERM;
 176             goto oerr;
 177         }
 178         ef.kernel = 1;
 179
 180     } else {
 181         err = EFTYPE;
 182         goto oerr;
 183     }
 184
 185     /*
 186      * Ok, we think we should handle this.
 187      */
 188     fp = file_alloc();
 189     if (fp == NULL) {
 190             printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: cannot allocate module info\n");
 191             err = EPERM;
 192             goto out;
 193     }
 194     if (ef.kernel)
 195         setenv("kernelname", filename, 1);
 196     fp->f_name = strdup(filename);
 197     fp->f_type = strdup(ef.kernel ? __elfN(kerneltype) : __elfN(moduletype));
 198
 199 #ifdef ELF_VERBOSE
 200     if (ef.kernel)
 201         printf("%s entry at 0x%jx\n", filename, (uintmax_t)dest);
 202 #else
 203     printf("%s ", filename);
 204 #endif
 205
 206     fp->f_size = __elfN(loadimage)(fp, &ef, dest);
 207     if (fp->f_size == 0 || fp->f_addr == 0)
 208         goto ioerr;
 209
 210     /* save exec header as metadata */
 211     file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*ehdr), ehdr);
 212
 213     /* Load OK, return module pointer */
 214     *result = (struct preloaded_file *)fp;
 215     err = 0;
 216     goto out;
 217
 218  ioerr:
 219     err = EIO;
 220  oerr:
 221     file_discard(fp);
 222  out:
 223     if (ef.firstpage)
 224         free(ef.firstpage);
 225     close(ef.fd);
 226     return(err);
 227 }
 228
 229 /*
 230  * With the file (fd) open on the image, and (ehdr) containing
 231  * the Elf header, load the image at (off)
 232  */
 233 static int
 234 __elfN(loadimage)(struct preloaded_file *fp, elf_file_t ef, u_int64_t off)
 235 {
 236     int         i;
 237     u_int       j;
 238     Elf_Ehdr    *ehdr;
 239     Elf_Phdr    *phdr, *php;
 240     Elf_Shdr    *shdr;
 241     int         ret;
 242     vm_offset_t firstaddr;
 243     vm_offset_t lastaddr;
 244     void        *buf;
 245     size_t      resid, chunk;
 246     ssize_t     result;
 247     vm_offset_t dest;
 248     Elf_Addr    ssym, esym;
 249     Elf_Dyn     *dp;
 250     Elf_Addr    adp;
 251     int         ndp;
 252     int         symstrindex;
 253     int         symtabindex;
 254     Elf_Size    size;
 255     u_int       fpcopy;
 256
 257     dp = NULL;
 258     shdr = NULL;
 259     ret = 0;
 260     firstaddr = lastaddr = 0;
 261     ehdr = ef->ehdr;
 262     if (ef->kernel) {
 263 #ifdef __i386__
 264 #if __ELF_WORD_SIZE == 64
 265         off = - (off & 0xffffffffff000000ull);/* x86_64 relocates after locore */
 266 #else
 267         off = - (off & 0xff000000u);    /* i386 relocates after locore */
 268 #endif
 269 #endif
 270     }
 271     ef->off = off;
 272
 273     if ((ehdr->e_phoff + ehdr->e_phnum * sizeof(*phdr)) > ef->firstlen) {
 274         printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: program header not within first page\n");
 275         goto out;
 276     }
 277     phdr = (Elf_Phdr *)(ef->firstpage + ehdr->e_phoff);
 278
 279     for (i = 0; i < ehdr->e_phnum; i++) {
 280         /* We want to load PT_LOAD segments only.. */
 281         if (phdr[i].p_type != PT_LOAD)
 282             continue;
 283
 284 #ifdef ELF_VERBOSE
 285         printf("Segment: 0x%lx@0x%lx -> 0x%lx-0x%lx",
 286             (long)phdr[i].p_filesz, (long)phdr[i].p_offset,
 287             (long)(phdr[i].p_vaddr + off),
 288             (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1));
 289 #else
 290         if ((phdr[i].p_flags & PF_W) == 0) {
 291             printf("text=0x%lx ", (long)phdr[i].p_filesz);
 292         } else {
 293             printf("data=0x%lx", (long)phdr[i].p_filesz);
 294             if (phdr[i].p_filesz < phdr[i].p_memsz)
 295                 printf("+0x%lx", (long)(phdr[i].p_memsz -phdr[i].p_filesz));
 296             printf(" ");
 297         }
 298 #endif
 299         fpcopy = 0;
 300         if (ef->firstlen > phdr[i].p_offset) {
 301             fpcopy = ef->firstlen - phdr[i].p_offset;
 302             archsw.arch_copyin(ef->firstpage + phdr[i].p_offset,
 303                                phdr[i].p_vaddr + off, fpcopy);
 304         }
 305         if (phdr[i].p_filesz > fpcopy) {
 306             if (lseek(ef->fd, (off_t)(phdr[i].p_offset + fpcopy),
 307                       SEEK_SET) == -1) {
 308                 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadexec: cannot seek\n");
 309                 goto out;
 310             }
 311             if (archsw.arch_readin(ef->fd, phdr[i].p_vaddr + off + fpcopy,
 312                 phdr[i].p_filesz - fpcopy) != (ssize_t)(phdr[i].p_filesz - fpcopy)) {
 313                 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadexec: archsw.readin failed\n");
 314                 goto out;
 315             }
 316         }
 317         /* clear space from oversized segments; eg: bss */
 318         if (phdr[i].p_filesz < phdr[i].p_memsz) {
 319 #ifdef ELF_VERBOSE
 320             printf(" (bss: 0x%lx-0x%lx)",
 321                 (long)(phdr[i].p_vaddr + off + phdr[i].p_filesz),
 322                 (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1));
 323 #endif
 324
 325             /* no archsw.arch_bzero */
 326             buf = malloc(PAGE_SIZE);
 327             if (buf == NULL) {
 328                 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: malloc() failed\n");
 329                 goto out;
 330             }
 331             bzero(buf, PAGE_SIZE);
 332             resid = phdr[i].p_memsz - phdr[i].p_filesz;
 333             dest = phdr[i].p_vaddr + off + phdr[i].p_filesz;
 334             while (resid > 0) {
 335                 chunk = min(PAGE_SIZE, resid);
 336                 archsw.arch_copyin(buf, dest, chunk);
 337                 resid -= chunk;
 338                 dest += chunk;
 339             }
 340             free(buf);
 341         }
 342 #ifdef ELF_VERBOSE
 343         printf("\n");
 344 #endif
 345
 346         if (firstaddr == 0 || firstaddr > (phdr[i].p_vaddr + off))
 347             firstaddr = phdr[i].p_vaddr + off;
 348         if (lastaddr == 0 || lastaddr < (phdr[i].p_vaddr + off + phdr[i].p_memsz))
 349             lastaddr = phdr[i].p_vaddr + off + phdr[i].p_memsz;
 350     }
 351     lastaddr = roundup(lastaddr, sizeof(long));
 352
 353     /*
 354      * Now grab the symbol tables.  This isn't easy if we're reading a
 355      * .gz file.  I think the rule is going to have to be that you must
 356      * strip a file to remove symbols before gzipping it so that we do not
 357      * try to lseek() on it.
 358      */
 359     chunk = ehdr->e_shnum * ehdr->e_shentsize;
 360     if (chunk == 0 || ehdr->e_shoff == 0)
 361         goto nosyms;
 362     shdr = malloc(chunk);
 363     if (shdr == NULL)
 364         goto nosyms;
 365     if (lseek(ef->fd, (off_t)ehdr->e_shoff, SEEK_SET) == -1) {
 366         printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: cannot lseek() to section headers");
 367         goto nosyms;
 368     }
 369     result = read(ef->fd, shdr, chunk);
 370     if (result < 0 || (size_t)result != chunk) {
 371         printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: read section headers failed");
 372         goto nosyms;
 373     }
 374     symtabindex = -1;
 375     symstrindex = -1;
 376     for (i = 0; i < ehdr->e_shnum; i++) {
 377         if (shdr[i].sh_type != SHT_SYMTAB)
 378             continue;
 379         for (j = 0; j < ehdr->e_phnum; j++) {
 380             if (phdr[j].p_type != PT_LOAD)
 381                 continue;
 382             if (shdr[i].sh_offset >= phdr[j].p_offset &&
 383                 (shdr[i].sh_offset + shdr[i].sh_size <=
 384                  phdr[j].p_offset + phdr[j].p_filesz)) {
 385                 shdr[i].sh_offset = 0;
 386                 shdr[i].sh_size = 0;
 387                 break;
 388             }
 389         }
 390         if (shdr[i].sh_offset == 0 || shdr[i].sh_size == 0)
 391             continue;           /* alread loaded in a PT_LOAD above */
 392         /* Save it for loading below */
 393         symtabindex = i;
 394         symstrindex = shdr[i].sh_link;
 395     }
 396     if (symtabindex < 0 || symstrindex < 0)
 397         goto nosyms;
 398
 399     /* Ok, committed to a load. */
 400 #ifndef ELF_VERBOSE
 401     printf("syms=[");
 402 #endif
 403     ssym = lastaddr;
 404     for (i = symtabindex; i >= 0; i = symstrindex) {
 405 #ifdef ELF_VERBOSE
 406         char    *secname;
 407
 408         switch(shdr[i].sh_type) {
 409             case SHT_SYMTAB:            /* Symbol table */
 410                 secname = "symtab";
 411                 break;
 412             case SHT_STRTAB:            /* String table */
 413                 secname = "strtab";
 414                 break;
 415             default:
 416                 secname = "WHOA!!";
 417                 break;
 418         }
 419 #endif
 420
 421         size = shdr[i].sh_size;
 422         archsw.arch_copyin(&size, lastaddr, sizeof(size));
 423         lastaddr += sizeof(size);
 424
 425 #ifdef ELF_VERBOSE
 426         printf("\n%s: 0x%lx@0x%lx -> 0x%lx-0x%lx", secname,
 427             shdr[i].sh_size, shdr[i].sh_offset,
 428             lastaddr, lastaddr + shdr[i].sh_size);
 429 #else
 430         if (i == symstrindex)
 431             printf("+");
 432         printf("0x%lx+0x%lx", (long)sizeof(size), (long)size);
 433 #endif
 434
 435         if (lseek(ef->fd, (off_t)shdr[i].sh_offset, SEEK_SET) == -1) {
 436             printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not seek for symbols - skipped!");
 437             lastaddr = ssym;
 438             ssym = 0;
 439             goto nosyms;
 440         }
 441         result = archsw.arch_readin(ef->fd, lastaddr, shdr[i].sh_size);
 442         if (result < 0 || (size_t)result != shdr[i].sh_size) {
 443             printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not read symbols - skipped!");
 444             lastaddr = ssym;
 445             ssym = 0;
 446             goto nosyms;
 447         }
 448         /* Reset offsets relative to ssym */
 449         lastaddr += shdr[i].sh_size;
 450         lastaddr = roundup(lastaddr, sizeof(size));
 451         if (i == symtabindex)
 452             symtabindex = -1;
 453         else if (i == symstrindex)
 454             symstrindex = -1;
 455     }
 456     esym = lastaddr;
 457 #ifndef ELF_VERBOSE
 458     printf("]");
 459 #endif
 460
 461     file_addmetadata(fp, MODINFOMD_SSYM, sizeof(ssym), &ssym);
 462     file_addmetadata(fp, MODINFOMD_ESYM, sizeof(esym), &esym);
 463
 464 nosyms:
 465     printf("\n");
 466
 467     ret = lastaddr - firstaddr;
 468     fp->f_addr = firstaddr;
 469
 470     php = NULL;
 471     for (i = 0; i < ehdr->e_phnum; i++) {
 472         if (phdr[i].p_type == PT_DYNAMIC) {
 473             php = phdr + i;
 474             adp = php->p_vaddr;
 475             file_addmetadata(fp, MODINFOMD_DYNAMIC, sizeof(adp), &adp);
 476             break;
 477         }
 478     }
 479
 480     if (php == NULL)    /* this is bad, we cannot get to symbols or _DYNAMIC */
 481         goto out;
 482
 483     ndp = php->p_filesz / sizeof(Elf_Dyn);
 484     if (ndp == 0)
 485         goto out;
 486     dp = malloc(php->p_filesz);
 487     if (dp == NULL)
 488         goto out;
 489     archsw.arch_copyout(php->p_vaddr + off, dp, php->p_filesz);
 490
 491     ef->strsz = 0;
 492     for (i = 0; i < ndp; i++) {
 493         if (dp[i].d_tag == 0)
 494             break;
 495         switch (dp[i].d_tag) {
 496         case DT_HASH:
 497             ef->hashtab = (Elf_Hashelt*)(uintptr_t)(dp[i].d_un.d_ptr + off);
 498             break;
 499         case DT_STRTAB:
 500             ef->strtab = (char *)(uintptr_t)(dp[i].d_un.d_ptr + off);
 501             break;
 502         case DT_STRSZ:
 503             ef->strsz = dp[i].d_un.d_val;
 504             break;
 505         case DT_SYMTAB:
 506             ef->symtab = (Elf_Sym*)(uintptr_t)(dp[i].d_un.d_ptr + off);
 507             break;
 508         case DT_RELA:
 509             ef->rela = (Elf_Rela *)(uintptr_t)(dp[i].d_un.d_ptr + off);
 510             break;
 511         case DT_RELASZ:
 512             ef->relasz = dp[i].d_un.d_val;
 513             break;
 514         default:
 515             break;
 516         }
 517     }
 518     if (ef->hashtab == NULL || ef->symtab == NULL ||
 519         ef->strtab == NULL || ef->strsz == 0)
 520         goto out;
 521     COPYOUT(ef->hashtab, &ef->nbuckets, sizeof(ef->nbuckets));
 522     COPYOUT(ef->hashtab + 1, &ef->nchains, sizeof(ef->nchains));
 523     ef->buckets = ef->hashtab + 2;
 524     ef->chains = ef->buckets + ef->nbuckets;
 525     if (__elfN(parse_modmetadata)(fp, ef) == 0)
 526         goto out;
 527
 528     if (ef->kernel)                     /* kernel must not depend on anything */
 529         goto out;
 530
 531 out:
 532     if (dp)
 533         free(dp);
 534     if (shdr)
 535         free(shdr);
 536     return ret;
 537 }
 538
 539 static char invalid_name[] = "bad";
 540
 541 char *
 542 fake_modname(const char *name)
 543 {
 544     const char *sp, *ep;
 545     char *fp;
 546     size_t len;
 547
 548     sp = strrchr(name, '/');
 549     if (sp)
 550         sp++;
 551     else
 552         sp = name;
 553     ep = strrchr(name, '.');
 554     if (ep) {
 555             if (ep == name) {
 556                 sp = invalid_name;
 557                 ep = invalid_name + sizeof(invalid_name) - 1;
 558             }
 559     } else
 560         ep = name + strlen(name);
 561     len = ep - sp;
 562     fp = malloc(len + 1);
 563     if (fp == NULL)
 564         return NULL;
 565     memcpy(fp, sp, len);
 566     fp[len] = '\0';
 567     return fp;
 568 }
 569
 570 #if defined(__i386__) && __ELF_WORD_SIZE == 64
 571 struct mod_metadata64 {
 572         int             md_version;     /* structure version MDTV_* */
 573         int             md_type;        /* type of entry MDT_* */
 574         u_int64_t       md_data;        /* specific data */
 575         u_int64_t       md_cval;        /* common string label */
 576 };
 577 #endif
 578
 579 int
 580 __elfN(parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef)
 581 {
 582     struct mod_metadata md;
 583 #if defined(__i386__) && __ELF_WORD_SIZE == 64
 584     struct mod_metadata64 md64;
 585 #endif
 586     struct mod_depend *mdepend;
 587     struct mod_version mver;
 588     Elf_Sym sym;
 589     char *s;
 590     int modcnt, minfolen;
 591     Elf_Addr v, p, p_stop;
 592
 593     if (__elfN(lookup_symbol)(fp, ef, "__start_set_modmetadata_set", &sym) != 0)
 594         return ENOENT;
 595     p = sym.st_value + ef->off;
 596     if (__elfN(lookup_symbol)(fp, ef, "__stop_set_modmetadata_set", &sym) != 0)
 597         return ENOENT;
 598     p_stop = sym.st_value + ef->off;
 599
 600     modcnt = 0;
 601     while (p < p_stop) {
 602         COPYOUT(p, &v, sizeof(v));
 603 #ifdef __sparc64__
 604         __elfN(reloc_ptr)(fp, ef, p, &v, sizeof(v));
 605 #else
 606         v += ef->off;
 607 #endif
 608 #if defined(__i386__) && __ELF_WORD_SIZE == 64
 609         COPYOUT(v, &md64, sizeof(md64));
 610         md.md_version = md64.md_version;
 611         md.md_type = md64.md_type;
 612         md.md_cval = (const char *)(uintptr_t)(md64.md_cval + ef->off);
 613         md.md_data = (void *)(uintptr_t)(md64.md_data + ef->off);
 614 #else
 615         COPYOUT(v, &md, sizeof(md));
 616 #ifdef __sparc64__
 617         __elfN(reloc_ptr)(fp, ef, v, &md, sizeof(md));
 618 #else
 619         md.md_cval += ef->off;
 620         md.md_data = (uint8_t *)md.md_data + ef->off;
 621 #endif
 622 #endif
 623         p += sizeof(Elf_Addr);
 624         switch(md.md_type) {
 625           case MDT_DEPEND:
 626             if (ef->kernel)             /* kernel must not depend on anything */
 627               break;
 628             s = strdupout((vm_offset_t)md.md_cval);
 629             minfolen = sizeof(*mdepend) + strlen(s) + 1;
 630             mdepend = malloc(minfolen);
 631             if (mdepend == NULL)
 632                 return ENOMEM;
 633             COPYOUT((vm_offset_t)md.md_data, mdepend, sizeof(*mdepend));
 634             strcpy((char*)(mdepend + 1), s);
 635             free(s);
 636             file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen, mdepend);
 637             free(mdepend);
 638             break;
 639           case MDT_VERSION:
 640             s = strdupout((vm_offset_t)md.md_cval);
 641             COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver));
 642             file_addmodule(fp, s, mver.mv_version, NULL);
 643             free(s);
 644             modcnt++;
 645             break;
 646         }
 647     }
 648     if (modcnt == 0) {
 649         s = fake_modname(fp->f_name);
 650         file_addmodule(fp, s, 1, NULL);
 651         free(s);
 652     }
 653     return 0;
 654 }
 655
 656 static unsigned long
 657 elf_hash(const char *name)
 658 {
 659     const unsigned char *p = (const unsigned char *) name;
 660     unsigned long h = 0;
 661     unsigned long g;
 662
 663     while (*p != '\0') {
 664         h = (h << 4) + *p++;
 665         if ((g = h & 0xf0000000) != 0)
 666             h ^= g >> 24;
 667         h &= ~g;
 668     }
 669     return h;
 670 }
 671
 672 static const char __elfN(bad_symtable)[] = "elf" __XSTRING(__ELF_WORD_SIZE) "_lookup_symbol: corrupt symbol table\n";
 673 int
 674 __elfN(lookup_symbol)(struct preloaded_file *fp, elf_file_t ef, const char* name,
 675                   Elf_Sym *symp)
 676 {
 677     Elf_Hashelt symnum;
 678     Elf_Sym sym;
 679     char *strp;
 680     unsigned long hash;
 681
 682     hash = elf_hash(name);
 683     COPYOUT(&ef->buckets[hash % ef->nbuckets], &symnum, sizeof(symnum));
 684
 685     while (symnum != STN_UNDEF) {
 686         if (symnum >= ef->nchains) {
 687             printf(__elfN(bad_symtable));
 688             return ENOENT;
 689         }
 690
 691         COPYOUT(ef->symtab + symnum, &sym, sizeof(sym));
 692         if (sym.st_name == 0) {
 693             printf(__elfN(bad_symtable));
 694             return ENOENT;
 695         }
 696
 697         strp = strdupout((vm_offset_t)(ef->strtab + sym.st_name));
 698         if (strcmp(name, strp) == 0) {
 699             free(strp);
 700             if (sym.st_shndx != SHN_UNDEF ||
 701                 (sym.st_value != 0 &&
 702                  ELF_ST_TYPE(sym.st_info) == STT_FUNC)) {
 703                 *symp = sym;
 704                 return 0;
 705             }
 706             return ENOENT;
 707         }
 708         free(strp);
 709         COPYOUT(&ef->chains[symnum], &symnum, sizeof(symnum));
 710     }
 711     return ENOENT;
 712 }
 713
 714 #ifdef __sparc__
 715 /*
 716  * Apply any intra-module relocations to the value. *p is the load address
 717  * of the value and val/len is the value to be modified. This does NOT modify
 718  * the image in-place, because this is done by kern_linker later on.
 719  */
 720 static void
 721 __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
 722     void *p, void *val, size_t len)
 723 {
 724         Elf_Addr off = (Elf_Addr)p - ef->off, word;
 725         size_t n;
 726         Elf_Rela r;
 727
 728         for (n = 0; n < ef->relasz / sizeof(r); n++) {
 729                 COPYOUT(ef->rela + n, &r, sizeof(r));
 730
 731                 if (r.r_offset >= off && r.r_offset < off + len &&
 732                     ELF_R_TYPE(r.r_info) == R_SPARC_RELATIVE) {
 733                         word = ef->off + r.r_addend;
 734                         bcopy(&word, (char *)val + (r.r_offset - off),
 735                             sizeof(word));
 736                 }
 737         }
 738 }
 739 #endif