sys/kern/link_elf_obj.c

   1 /*-
   2  * Copyright (c) 1998-2000 Doug Rabson
   3  * Copyright (c) 2004 Peter Wemm
   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 "opt_ddb.h"
  32
  33 #include <sys/param.h>
  34 #include <sys/systm.h>
  35 #include <sys/kernel.h>
  36 #include <sys/lock.h>
  37 #include <sys/malloc.h>
  38 #include <sys/mutex.h>
  39 #include <sys/mount.h>
  40 #include <sys/proc.h>
  41 #include <sys/namei.h>
  42 #include <sys/fcntl.h>
  43 #include <sys/vnode.h>
  44 #include <sys/linker.h>
  45
  46 #include <machine/elf.h>
  47
  48 #include <net/vnet.h>
  49
  50 #include <security/mac/mac_framework.h>
  51
  52 #include <vm/vm.h>
  53 #include <vm/vm_param.h>
  54 #include <vm/vm_object.h>
  55 #include <vm/vm_kern.h>
  56 #include <vm/vm_extern.h>
  57 #include <vm/pmap.h>
  58 #include <vm/vm_map.h>
  59
  60 #include <sys/link_elf.h>
  61
  62 #ifdef DDB_CTF
  63 #include <net/zlib.h>
  64 #endif
  65
  66 #include "linker_if.h"
  67
  68 typedef struct {
  69         void            *addr;
  70         Elf_Off         size;
  71         int             flags;
  72         int             sec;    /* Original section */
  73         char            *name;
  74 } Elf_progent;
  75
  76 typedef struct {
  77         Elf_Rel         *rel;
  78         int             nrel;
  79         int             sec;
  80 } Elf_relent;
  81
  82 typedef struct {
  83         Elf_Rela        *rela;
  84         int             nrela;
  85         int             sec;
  86 } Elf_relaent;
  87
  88
  89 typedef struct elf_file {
  90         struct linker_file lf;          /* Common fields */
  91
  92         int             preloaded;
  93         caddr_t         address;        /* Relocation address */
  94         vm_object_t     object;         /* VM object to hold file pages */
  95         Elf_Shdr        *e_shdr;
  96
  97         Elf_progent     *progtab;
  98         int             nprogtab;
  99
 100         Elf_relaent     *relatab;
 101         int             nrelatab;
 102
 103         Elf_relent      *reltab;
 104         int             nreltab;
 105
 106         Elf_Sym         *ddbsymtab;     /* The symbol table we are using */
 107         long            ddbsymcnt;      /* Number of symbols */
 108         caddr_t         ddbstrtab;      /* String table */
 109         long            ddbstrcnt;      /* number of bytes in string table */
 110
 111         caddr_t         shstrtab;       /* Section name string table */
 112         long            shstrcnt;       /* number of bytes in string table */
 113
 114         caddr_t         ctftab;         /* CTF table */
 115         long            ctfcnt;         /* number of bytes in CTF table */
 116         caddr_t         ctfoff;         /* CTF offset table */
 117         caddr_t         typoff;         /* Type offset table */
 118         long            typlen;         /* Number of type entries. */
 119
 120 } *elf_file_t;
 121
 122 #include <kern/kern_ctf.c>
 123
 124 static int      link_elf_link_preload(linker_class_t cls,
 125                     const char *, linker_file_t *);
 126 static int      link_elf_link_preload_finish(linker_file_t);
 127 static int      link_elf_load_file(linker_class_t, const char *, linker_file_t *);
 128 static int      link_elf_lookup_symbol(linker_file_t, const char *,
 129                     c_linker_sym_t *);
 130 static int      link_elf_symbol_values(linker_file_t, c_linker_sym_t,
 131                     linker_symval_t *);
 132 static int      link_elf_search_symbol(linker_file_t, caddr_t value,
 133                     c_linker_sym_t *sym, long *diffp);
 134
 135 static void     link_elf_unload_file(linker_file_t);
 136 static int      link_elf_lookup_set(linker_file_t, const char *,
 137                     void ***, void ***, int *);
 138 static int      link_elf_each_function_name(linker_file_t,
 139                     int (*)(const char *, void *), void *);
 140 static int      link_elf_each_function_nameval(linker_file_t,
 141                                 linker_function_nameval_callback_t,
 142                                 void *);
 143 static void     link_elf_reloc_local(linker_file_t);
 144 static long     link_elf_symtab_get(linker_file_t, const Elf_Sym **);
 145 static long     link_elf_strtab_get(linker_file_t, caddr_t *);
 146
 147 static Elf_Addr elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps);
 148
 149 static kobj_method_t link_elf_methods[] = {
 150         KOBJMETHOD(linker_lookup_symbol,        link_elf_lookup_symbol),
 151         KOBJMETHOD(linker_symbol_values,        link_elf_symbol_values),
 152         KOBJMETHOD(linker_search_symbol,        link_elf_search_symbol),
 153         KOBJMETHOD(linker_unload,               link_elf_unload_file),
 154         KOBJMETHOD(linker_load_file,            link_elf_load_file),
 155         KOBJMETHOD(linker_link_preload,         link_elf_link_preload),
 156         KOBJMETHOD(linker_link_preload_finish,  link_elf_link_preload_finish),
 157         KOBJMETHOD(linker_lookup_set,           link_elf_lookup_set),
 158         KOBJMETHOD(linker_each_function_name,   link_elf_each_function_name),
 159         KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
 160         KOBJMETHOD(linker_ctf_get,              link_elf_ctf_get),
 161         KOBJMETHOD(linker_symtab_get,           link_elf_symtab_get),
 162         KOBJMETHOD(linker_strtab_get,           link_elf_strtab_get),
 163         { 0, 0 }
 164 };
 165
 166 static struct linker_class link_elf_class = {
 167 #if ELF_TARG_CLASS == ELFCLASS32
 168         "elf32_obj",
 169 #else
 170         "elf64_obj",
 171 #endif
 172         link_elf_methods, sizeof(struct elf_file)
 173 };
 174
 175 static int      relocate_file(elf_file_t ef);
 176
 177 static void
 178 link_elf_error(const char *filename, const char *s)
 179 {
 180         if (filename == NULL)
 181                 printf("kldload: %s\n", s);
 182         else
 183                 printf("kldload: %s: %s\n", filename, s);
 184 }
 185
 186 static void
 187 link_elf_init(void *arg)
 188 {
 189
 190         linker_add_class(&link_elf_class);
 191 }
 192
 193 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
 194
 195 static int
 196 link_elf_link_preload(linker_class_t cls, const char *filename,
 197     linker_file_t *result)
 198 {
 199         Elf_Ehdr *hdr;
 200         Elf_Shdr *shdr;
 201         Elf_Sym *es;
 202         void *modptr, *baseptr, *sizeptr;
 203         char *type;
 204         elf_file_t ef;
 205         linker_file_t lf;
 206         Elf_Addr off;
 207         int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
 208
 209         /* Look to see if we have the file preloaded */
 210         modptr = preload_search_by_name(filename);
 211         if (modptr == NULL)
 212                 return ENOENT;
 213
 214         type = (char *)preload_search_info(modptr, MODINFO_TYPE);
 215         baseptr = preload_search_info(modptr, MODINFO_ADDR);
 216         sizeptr = preload_search_info(modptr, MODINFO_SIZE);
 217         hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
 218             MODINFOMD_ELFHDR);
 219         shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
 220             MODINFOMD_SHDR);
 221         if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
 222             " obj module") != 0 &&
 223             strcmp(type, "elf obj module") != 0)) {
 224                 return (EFTYPE);
 225         }
 226         if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
 227             shdr == NULL)
 228                 return (EINVAL);
 229
 230         lf = linker_make_file(filename, &link_elf_class);
 231         if (lf == NULL)
 232                 return (ENOMEM);
 233
 234         ef = (elf_file_t)lf;
 235         ef->preloaded = 1;
 236         ef->address = *(caddr_t *)baseptr;
 237         lf->address = *(caddr_t *)baseptr;
 238         lf->size = *(size_t *)sizeptr;
 239
 240         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
 241             hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
 242             hdr->e_ident[EI_VERSION] != EV_CURRENT ||
 243             hdr->e_version != EV_CURRENT ||
 244             hdr->e_type != ET_REL ||
 245             hdr->e_machine != ELF_TARG_MACH) {
 246                 error = EFTYPE;
 247                 goto out;
 248         }
 249         ef->e_shdr = shdr;
 250
 251         /* Scan the section header for information and table sizing. */
 252         symtabindex = -1;
 253         symstrindex = -1;
 254         for (i = 0; i < hdr->e_shnum; i++) {
 255                 switch (shdr[i].sh_type) {
 256                 case SHT_PROGBITS:
 257                 case SHT_NOBITS:
 258                         ef->nprogtab++;
 259                         break;
 260                 case SHT_SYMTAB:
 261                         symtabindex = i;
 262                         symstrindex = shdr[i].sh_link;
 263                         break;
 264                 case SHT_REL:
 265                         ef->nreltab++;
 266                         break;
 267                 case SHT_RELA:
 268                         ef->nrelatab++;
 269                         break;
 270                 }
 271         }
 272
 273         shstrindex = hdr->e_shstrndx;
 274         if (ef->nprogtab == 0 || symstrindex < 0 ||
 275             symstrindex >= hdr->e_shnum ||
 276             shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
 277             shstrindex >= hdr->e_shnum ||
 278             shdr[shstrindex].sh_type != SHT_STRTAB) {
 279                 printf("%s: bad/missing section headers\n", filename);
 280                 error = ENOEXEC;
 281                 goto out;
 282         }
 283
 284         /* Allocate space for tracking the load chunks */
 285         if (ef->nprogtab != 0)
 286                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 287                     M_LINKER, M_WAITOK | M_ZERO);
 288         if (ef->nreltab != 0)
 289                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 290                     M_LINKER, M_WAITOK | M_ZERO);
 291         if (ef->nrelatab != 0)
 292                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 293                     M_LINKER, M_WAITOK | M_ZERO);
 294         if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
 295             (ef->nreltab != 0 && ef->reltab == NULL) ||
 296             (ef->nrelatab != 0 && ef->relatab == NULL)) {
 297                 error = ENOMEM;
 298                 goto out;
 299         }
 300
 301         /* XXX, relocate the sh_addr fields saved by the loader. */
 302         off = 0;
 303         for (i = 0; i < hdr->e_shnum; i++) {
 304                 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
 305                         off = shdr[i].sh_addr;
 306         }
 307         for (i = 0; i < hdr->e_shnum; i++) {
 308                 if (shdr[i].sh_addr != 0)
 309                         shdr[i].sh_addr = shdr[i].sh_addr - off +
 310                             (Elf_Addr)ef->address;
 311         }
 312
 313         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 314         ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
 315         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 316         ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
 317         ef->shstrcnt = shdr[shstrindex].sh_size;
 318         ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
 319
 320         /* Now fill out progtab and the relocation tables. */
 321         pb = 0;
 322         rl = 0;
 323         ra = 0;
 324         for (i = 0; i < hdr->e_shnum; i++) {
 325                 switch (shdr[i].sh_type) {
 326                 case SHT_PROGBITS:
 327                 case SHT_NOBITS:
 328                         ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
 329                         if (shdr[i].sh_type == SHT_PROGBITS)
 330                                 ef->progtab[pb].name = "<<PROGBITS>>";
 331                         else
 332                                 ef->progtab[pb].name = "<<NOBITS>>";
 333                         ef->progtab[pb].size = shdr[i].sh_size;
 334                         ef->progtab[pb].sec = i;
 335                         if (ef->shstrtab && shdr[i].sh_name != 0)
 336                                 ef->progtab[pb].name =
 337                                     ef->shstrtab + shdr[i].sh_name;
 338                         if (ef->progtab[pb].name != NULL &&
 339                             !strcmp(ef->progtab[pb].name, "set_pcpu")) {
 340                                 void *dpcpu;
 341
 342                                 dpcpu = dpcpu_alloc(shdr[i].sh_size);
 343                                 if (dpcpu == NULL) {
 344                                         error = ENOSPC;
 345                                         goto out;
 346                                 }
 347                                 memcpy(dpcpu, ef->progtab[pb].addr,
 348                                     ef->progtab[pb].size);
 349                                 dpcpu_copy(dpcpu, shdr[i].sh_size);
 350                                 ef->progtab[pb].addr = dpcpu;
 351 #ifdef VIMAGE
 352                         } else if (ef->progtab[pb].name != NULL &&
 353                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
 354                                 void *vnet_data;
 355
 356                                 vnet_data = vnet_data_alloc(shdr[i].sh_size);
 357                                 if (vnet_data == NULL) {
 358                                         error = ENOSPC;
 359                                         goto out;
 360                                 }
 361                                 memcpy(vnet_data, ef->progtab[pb].addr,
 362                                     ef->progtab[pb].size);
 363                                 vnet_data_copy(vnet_data, shdr[i].sh_size);
 364                                 ef->progtab[pb].addr = vnet_data;
 365 #endif
 366                         }
 367
 368                         /* Update all symbol values with the offset. */
 369                         for (j = 0; j < ef->ddbsymcnt; j++) {
 370                                 es = &ef->ddbsymtab[j];
 371                                 if (es->st_shndx != i)
 372                                         continue;
 373                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 374                         }
 375                         pb++;
 376                         break;
 377                 case SHT_REL:
 378                         ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
 379                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 380                         ef->reltab[rl].sec = shdr[i].sh_info;
 381                         rl++;
 382                         break;
 383                 case SHT_RELA:
 384                         ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
 385                         ef->relatab[ra].nrela =
 386                             shdr[i].sh_size / sizeof(Elf_Rela);
 387                         ef->relatab[ra].sec = shdr[i].sh_info;
 388                         ra++;
 389                         break;
 390                 }
 391         }
 392         if (pb != ef->nprogtab)
 393                 panic("lost progbits");
 394         if (rl != ef->nreltab)
 395                 panic("lost reltab");
 396         if (ra != ef->nrelatab)
 397                 panic("lost relatab");
 398
 399         /* Local intra-module relocations */
 400         link_elf_reloc_local(lf);
 401
 402         *result = lf;
 403         return (0);
 404
 405 out:
 406         /* preload not done this way */
 407         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 408         return (error);
 409 }
 410
 411 static int
 412 link_elf_link_preload_finish(linker_file_t lf)
 413 {
 414         elf_file_t ef;
 415         int error;
 416
 417         ef = (elf_file_t)lf;
 418         error = relocate_file(ef);
 419         if (error)
 420                 return error;
 421
 422         /* Notify MD code that a module is being loaded. */
 423         error = elf_cpu_load_file(lf);
 424         if (error)
 425                 return (error);
 426
 427         return (0);
 428 }
 429
 430 static int
 431 link_elf_load_file(linker_class_t cls, const char *filename,
 432     linker_file_t *result)
 433 {
 434         struct nameidata nd;
 435         struct thread *td = curthread;  /* XXX */
 436         Elf_Ehdr *hdr;
 437         Elf_Shdr *shdr;
 438         Elf_Sym *es;
 439         int nbytes, i, j;
 440         vm_offset_t mapbase;
 441         size_t mapsize;
 442         int error = 0;
 443         int resid, flags;
 444         elf_file_t ef;
 445         linker_file_t lf;
 446         int symtabindex;
 447         int symstrindex;
 448         int shstrindex;
 449         int nsym;
 450         int pb, rl, ra;
 451         int alignmask;
 452         int vfslocked;
 453
 454         shdr = NULL;
 455         lf = NULL;
 456         mapsize = 0;
 457         hdr = NULL;
 458
 459         NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td);
 460         flags = FREAD;
 461         error = vn_open(&nd, &flags, 0, NULL);
 462         if (error)
 463                 return error;
 464         vfslocked = NDHASGIANT(&nd);
 465         NDFREE(&nd, NDF_ONLY_PNBUF);
 466         if (nd.ni_vp->v_type != VREG) {
 467                 error = ENOEXEC;
 468                 goto out;
 469         }
 470 #ifdef MAC
 471         error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
 472         if (error) {
 473                 goto out;
 474         }
 475 #endif
 476
 477         /* Read the elf header from the file. */
 478         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
 479         if (hdr == NULL) {
 480                 error = ENOMEM;
 481                 goto out;
 482         }
 483         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
 484             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 485             &resid, td);
 486         if (error)
 487                 goto out;
 488         if (resid != 0){
 489                 error = ENOEXEC;
 490                 goto out;
 491         }
 492
 493         if (!IS_ELF(*hdr)) {
 494                 error = ENOEXEC;
 495                 goto out;
 496         }
 497
 498         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
 499             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
 500                 link_elf_error(filename, "Unsupported file layout");
 501                 error = ENOEXEC;
 502                 goto out;
 503         }
 504         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
 505             || hdr->e_version != EV_CURRENT) {
 506                 link_elf_error(filename, "Unsupported file version");
 507                 error = ENOEXEC;
 508                 goto out;
 509         }
 510         if (hdr->e_type != ET_REL) {
 511                 error = ENOSYS;
 512                 goto out;
 513         }
 514         if (hdr->e_machine != ELF_TARG_MACH) {
 515                 link_elf_error(filename, "Unsupported machine");
 516                 error = ENOEXEC;
 517                 goto out;
 518         }
 519
 520         lf = linker_make_file(filename, &link_elf_class);
 521         if (!lf) {
 522                 error = ENOMEM;
 523                 goto out;
 524         }
 525         ef = (elf_file_t) lf;
 526         ef->nprogtab = 0;
 527         ef->e_shdr = 0;
 528         ef->nreltab = 0;
 529         ef->nrelatab = 0;
 530
 531         /* Allocate and read in the section header */
 532         nbytes = hdr->e_shnum * hdr->e_shentsize;
 533         if (nbytes == 0 || hdr->e_shoff == 0 ||
 534             hdr->e_shentsize != sizeof(Elf_Shdr)) {
 535                 error = ENOEXEC;
 536                 goto out;
 537         }
 538         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
 539         if (shdr == NULL) {
 540                 error = ENOMEM;
 541                 goto out;
 542         }
 543         ef->e_shdr = shdr;
 544         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
 545             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
 546         if (error)
 547                 goto out;
 548         if (resid) {
 549                 error = ENOEXEC;
 550                 goto out;
 551         }
 552
 553         /* Scan the section header for information and table sizing. */
 554         nsym = 0;
 555         symtabindex = -1;
 556         symstrindex = -1;
 557         for (i = 0; i < hdr->e_shnum; i++) {
 558                 switch (shdr[i].sh_type) {
 559                 case SHT_PROGBITS:
 560                 case SHT_NOBITS:
 561                         ef->nprogtab++;
 562                         break;
 563                 case SHT_SYMTAB:
 564                         nsym++;
 565                         symtabindex = i;
 566                         symstrindex = shdr[i].sh_link;
 567                         break;
 568                 case SHT_REL:
 569                         ef->nreltab++;
 570                         break;
 571                 case SHT_RELA:
 572                         ef->nrelatab++;
 573                         break;
 574                 case SHT_STRTAB:
 575                         break;
 576                 }
 577         }
 578         if (ef->nprogtab == 0) {
 579                 link_elf_error(filename, "file has no contents");
 580                 error = ENOEXEC;
 581                 goto out;
 582         }
 583         if (nsym != 1) {
 584                 /* Only allow one symbol table for now */
 585                 link_elf_error(filename, "file has no valid symbol table");
 586                 error = ENOEXEC;
 587                 goto out;
 588         }
 589         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
 590             shdr[symstrindex].sh_type != SHT_STRTAB) {
 591                 link_elf_error(filename, "file has invalid symbol strings");
 592                 error = ENOEXEC;
 593                 goto out;
 594         }
 595
 596         /* Allocate space for tracking the load chunks */
 597         if (ef->nprogtab != 0)
 598                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 599                     M_LINKER, M_WAITOK | M_ZERO);
 600         if (ef->nreltab != 0)
 601                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 602                     M_LINKER, M_WAITOK | M_ZERO);
 603         if (ef->nrelatab != 0)
 604                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 605                     M_LINKER, M_WAITOK | M_ZERO);
 606         if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
 607             (ef->nreltab != 0 && ef->reltab == NULL) ||
 608             (ef->nrelatab != 0 && ef->relatab == NULL)) {
 609                 error = ENOMEM;
 610                 goto out;
 611         }
 612
 613         if (symtabindex == -1)
 614                 panic("lost symbol table index");
 615         /* Allocate space for and load the symbol table */
 616         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 617         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
 618         if (ef->ddbsymtab == NULL) {
 619                 error = ENOMEM;
 620                 goto out;
 621         }
 622         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
 623             shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
 624             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 625             &resid, td);
 626         if (error)
 627                 goto out;
 628         if (resid != 0){
 629                 error = EINVAL;
 630                 goto out;
 631         }
 632
 633         if (symstrindex == -1)
 634                 panic("lost symbol string index");
 635         /* Allocate space for and load the symbol strings */
 636         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 637         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
 638         if (ef->ddbstrtab == NULL) {
 639                 error = ENOMEM;
 640                 goto out;
 641         }
 642         error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
 643             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
 644             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 645             &resid, td);
 646         if (error)
 647                 goto out;
 648         if (resid != 0){
 649                 error = EINVAL;
 650                 goto out;
 651         }
 652
 653         /* Do we have a string table for the section names?  */
 654         shstrindex = -1;
 655         if (hdr->e_shstrndx != 0 &&
 656             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
 657                 shstrindex = hdr->e_shstrndx;
 658                 ef->shstrcnt = shdr[shstrindex].sh_size;
 659                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
 660                     M_WAITOK);
 661                 if (ef->shstrtab == NULL) {
 662                         error = ENOMEM;
 663                         goto out;
 664                 }
 665                 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
 666                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
 667                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 668                     &resid, td);
 669                 if (error)
 670                         goto out;
 671                 if (resid != 0){
 672                         error = EINVAL;
 673                         goto out;
 674                 }
 675         }
 676
 677         /* Size up code/data(progbits) and bss(nobits). */
 678         alignmask = 0;
 679         for (i = 0; i < hdr->e_shnum; i++) {
 680                 switch (shdr[i].sh_type) {
 681                 case SHT_PROGBITS:
 682                 case SHT_NOBITS:
 683                         alignmask = shdr[i].sh_addralign - 1;
 684                         mapsize += alignmask;
 685                         mapsize &= ~alignmask;
 686                         mapsize += shdr[i].sh_size;
 687                         break;
 688                 }
 689         }
 690
 691         /*
 692          * We know how much space we need for the text/data/bss/etc.
 693          * This stuff needs to be in a single chunk so that profiling etc
 694          * can get the bounds and gdb can associate offsets with modules
 695          */
 696         ef->object = vm_object_allocate(OBJT_DEFAULT,
 697             round_page(mapsize) >> PAGE_SHIFT);
 698         if (ef->object == NULL) {
 699                 error = ENOMEM;
 700                 goto out;
 701         }
 702         ef->address = (caddr_t) vm_map_min(kernel_map);
 703
 704         /*
 705          * In order to satisfy amd64's architectural requirements on the
 706          * location of code and data in the kernel's address space, request a
 707          * mapping that is above the kernel.
 708          */
 709         mapbase = KERNBASE;
 710         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
 711             round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE);
 712         if (error) {
 713                 vm_object_deallocate(ef->object);
 714                 ef->object = 0;
 715                 goto out;
 716         }
 717
 718         /* Wire the pages */
 719         error = vm_map_wire(kernel_map, mapbase,
 720             mapbase + round_page(mapsize),
 721             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 722         if (error != KERN_SUCCESS) {
 723                 error = ENOMEM;
 724                 goto out;
 725         }
 726
 727         /* Inform the kld system about the situation */
 728         lf->address = ef->address = (caddr_t)mapbase;
 729         lf->size = mapsize;
 730
 731         /*
 732          * Now load code/data(progbits), zero bss(nobits), allocate space for
 733          * and load relocs
 734          */
 735         pb = 0;
 736         rl = 0;
 737         ra = 0;
 738         alignmask = 0;
 739         for (i = 0; i < hdr->e_shnum; i++) {
 740                 switch (shdr[i].sh_type) {
 741                 case SHT_PROGBITS:
 742                 case SHT_NOBITS:
 743                         alignmask = shdr[i].sh_addralign - 1;
 744                         mapbase += alignmask;
 745                         mapbase &= ~alignmask;
 746                         if (ef->shstrtab && shdr[i].sh_name != 0)
 747                                 ef->progtab[pb].name =
 748                                     ef->shstrtab + shdr[i].sh_name;
 749                         else if (shdr[i].sh_type == SHT_PROGBITS)
 750                                 ef->progtab[pb].name = "<<PROGBITS>>";
 751                         else
 752                                 ef->progtab[pb].name = "<<NOBITS>>";
 753                         if (ef->progtab[pb].name != NULL &&
 754                             !strcmp(ef->progtab[pb].name, "set_pcpu"))
 755                                 ef->progtab[pb].addr =
 756                                     dpcpu_alloc(shdr[i].sh_size);
 757 #ifdef VIMAGE
 758                         else if (ef->progtab[pb].name != NULL &&
 759                             !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 760                                 ef->progtab[pb].addr =
 761                                     vnet_data_alloc(shdr[i].sh_size);
 762 #endif
 763                         else
 764                                 ef->progtab[pb].addr =
 765                                     (void *)(uintptr_t)mapbase;
 766                         if (ef->progtab[pb].addr == NULL) {
 767                                 error = ENOSPC;
 768                                 goto out;
 769                         }
 770                         ef->progtab[pb].size = shdr[i].sh_size;
 771                         ef->progtab[pb].sec = i;
 772                         if (shdr[i].sh_type == SHT_PROGBITS) {
 773                                 error = vn_rdwr(UIO_READ, nd.ni_vp,
 774                                     ef->progtab[pb].addr,
 775                                     shdr[i].sh_size, shdr[i].sh_offset,
 776                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
 777                                     NOCRED, &resid, td);
 778                                 if (error)
 779                                         goto out;
 780                                 if (resid != 0){
 781                                         error = EINVAL;
 782                                         goto out;
 783                                 }
 784                                 /* Initialize the per-cpu or vnet area. */
 785                                 if (ef->progtab[pb].addr != (void *)mapbase &&
 786                                     !strcmp(ef->progtab[pb].name, "set_pcpu"))
 787                                         dpcpu_copy(ef->progtab[pb].addr,
 788                                             shdr[i].sh_size);
 789 #ifdef VIMAGE
 790                                 else if (ef->progtab[pb].addr !=
 791                                     (void *)mapbase &&
 792                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 793                                         vnet_data_copy(ef->progtab[pb].addr,
 794                                             shdr[i].sh_size);
 795 #endif
 796                         } else
 797                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
 798
 799                         /* Update all symbol values with the offset. */
 800                         for (j = 0; j < ef->ddbsymcnt; j++) {
 801                                 es = &ef->ddbsymtab[j];
 802                                 if (es->st_shndx != i)
 803                                         continue;
 804                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 805                         }
 806                         mapbase += shdr[i].sh_size;
 807                         pb++;
 808                         break;
 809                 case SHT_REL:
 810                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
 811                             M_WAITOK);
 812                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 813                         ef->reltab[rl].sec = shdr[i].sh_info;
 814                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 815                             (void *)ef->reltab[rl].rel,
 816                             shdr[i].sh_size, shdr[i].sh_offset,
 817                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 818                             &resid, td);
 819                         if (error)
 820                                 goto out;
 821                         if (resid != 0){
 822                                 error = EINVAL;
 823                                 goto out;
 824                         }
 825                         rl++;
 826                         break;
 827                 case SHT_RELA:
 828                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
 829                             M_WAITOK);
 830                         ef->relatab[ra].nrela =
 831                             shdr[i].sh_size / sizeof(Elf_Rela);
 832                         ef->relatab[ra].sec = shdr[i].sh_info;
 833                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 834                             (void *)ef->relatab[ra].rela,
 835                             shdr[i].sh_size, shdr[i].sh_offset,
 836                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 837                             &resid, td);
 838                         if (error)
 839                                 goto out;
 840                         if (resid != 0){
 841                                 error = EINVAL;
 842                                 goto out;
 843                         }
 844                         ra++;
 845                         break;
 846                 }
 847         }
 848         if (pb != ef->nprogtab)
 849                 panic("lost progbits");
 850         if (rl != ef->nreltab)
 851                 panic("lost reltab");
 852         if (ra != ef->nrelatab)
 853                 panic("lost relatab");
 854         if (mapbase != (vm_offset_t)ef->address + mapsize)
 855                 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
 856                     mapbase, ef->address, mapsize,
 857                     (vm_offset_t)ef->address + mapsize);
 858
 859         /* Local intra-module relocations */
 860         link_elf_reloc_local(lf);
 861
 862         /* Pull in dependencies */
 863         VOP_UNLOCK(nd.ni_vp, 0);
 864         error = linker_load_dependencies(lf);
 865         vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
 866         if (error)
 867                 goto out;
 868
 869         /* External relocations */
 870         error = relocate_file(ef);
 871         if (error)
 872                 goto out;
 873
 874         /* Notify MD code that a module is being loaded. */
 875         error = elf_cpu_load_file(lf);
 876         if (error)
 877                 goto out;
 878
 879         *result = lf;
 880
 881 out:
 882         if (error && lf)
 883                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 884         if (hdr)
 885                 free(hdr, M_LINKER);
 886         VOP_UNLOCK(nd.ni_vp, 0);
 887         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
 888         VFS_UNLOCK_GIANT(vfslocked);
 889
 890         return error;
 891 }
 892
 893 static void
 894 link_elf_unload_file(linker_file_t file)
 895 {
 896         elf_file_t ef = (elf_file_t) file;
 897         int i;
 898
 899         /* Notify MD code that a module is being unloaded. */
 900         elf_cpu_unload_file(file);
 901
 902         if (ef->progtab) {
 903                 for (i = 0; i < ef->nprogtab; i++) {
 904                         if (ef->progtab[i].size == 0)
 905                                 continue;
 906                         if (ef->progtab[i].name == NULL)
 907                                 continue;
 908                         if (!strcmp(ef->progtab[i].name, "set_pcpu"))
 909                                 dpcpu_free(ef->progtab[i].addr,
 910                                     ef->progtab[i].size);
 911 #ifdef VIMAGE
 912                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
 913                                 vnet_data_free(ef->progtab[i].addr,
 914                                     ef->progtab[i].size);
 915 #endif
 916                 }
 917         }
 918         if (ef->preloaded) {
 919                 if (ef->reltab)
 920                         free(ef->reltab, M_LINKER);
 921                 if (ef->relatab)
 922                         free(ef->relatab, M_LINKER);
 923                 if (ef->progtab)
 924                         free(ef->progtab, M_LINKER);
 925                 if (ef->ctftab)
 926                         free(ef->ctftab, M_LINKER);
 927                 if (ef->ctfoff)
 928                         free(ef->ctfoff, M_LINKER);
 929                 if (ef->typoff)
 930                         free(ef->typoff, M_LINKER);
 931                 if (file->filename != NULL)
 932                         preload_delete_name(file->filename);
 933                 /* XXX reclaim module memory? */
 934                 return;
 935         }
 936
 937         for (i = 0; i < ef->nreltab; i++)
 938                 if (ef->reltab[i].rel)
 939                         free(ef->reltab[i].rel, M_LINKER);
 940         for (i = 0; i < ef->nrelatab; i++)
 941                 if (ef->relatab[i].rela)
 942                         free(ef->relatab[i].rela, M_LINKER);
 943         if (ef->reltab)
 944                 free(ef->reltab, M_LINKER);
 945         if (ef->relatab)
 946                 free(ef->relatab, M_LINKER);
 947         if (ef->progtab)
 948                 free(ef->progtab, M_LINKER);
 949
 950         if (ef->object) {
 951                 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
 952                     (vm_offset_t) ef->address +
 953                     (ef->object->size << PAGE_SHIFT));
 954         }
 955         if (ef->e_shdr)
 956                 free(ef->e_shdr, M_LINKER);
 957         if (ef->ddbsymtab)
 958                 free(ef->ddbsymtab, M_LINKER);
 959         if (ef->ddbstrtab)
 960                 free(ef->ddbstrtab, M_LINKER);
 961         if (ef->shstrtab)
 962                 free(ef->shstrtab, M_LINKER);
 963         if (ef->ctftab)
 964                 free(ef->ctftab, M_LINKER);
 965         if (ef->ctfoff)
 966                 free(ef->ctfoff, M_LINKER);
 967         if (ef->typoff)
 968                 free(ef->typoff, M_LINKER);
 969 }
 970
 971 static const char *
 972 symbol_name(elf_file_t ef, Elf_Size r_info)
 973 {
 974         const Elf_Sym *ref;
 975
 976         if (ELF_R_SYM(r_info)) {
 977                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
 978                 return ef->ddbstrtab + ref->st_name;
 979         } else
 980                 return NULL;
 981 }
 982
 983 static Elf_Addr
 984 findbase(elf_file_t ef, int sec)
 985 {
 986         int i;
 987         Elf_Addr base = 0;
 988
 989         for (i = 0; i < ef->nprogtab; i++) {
 990                 if (sec == ef->progtab[i].sec) {
 991                         base = (Elf_Addr)ef->progtab[i].addr;
 992                         break;
 993                 }
 994         }
 995         return base;
 996 }
 997
 998 static int
 999 relocate_file(elf_file_t ef)
1000 {
1001         const Elf_Rel *rellim;
1002         const Elf_Rel *rel;
1003         const Elf_Rela *relalim;
1004         const Elf_Rela *rela;
1005         const char *symname;
1006         const Elf_Sym *sym;
1007         int i;
1008         Elf_Size symidx;
1009         Elf_Addr base;
1010
1011
1012         /* Perform relocations without addend if there are any: */
1013         for (i = 0; i < ef->nreltab; i++) {
1014                 rel = ef->reltab[i].rel;
1015                 if (rel == NULL)
1016                         panic("lost a reltab!");
1017                 rellim = rel + ef->reltab[i].nrel;
1018                 base = findbase(ef, ef->reltab[i].sec);
1019                 if (base == 0)
1020                         panic("lost base for reltab");
1021                 for ( ; rel < rellim; rel++) {
1022                         symidx = ELF_R_SYM(rel->r_info);
1023                         if (symidx >= ef->ddbsymcnt)
1024                                 continue;
1025                         sym = ef->ddbsymtab + symidx;
1026                         /* Local relocs are already done */
1027                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1028                                 continue;
1029                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1030                             elf_obj_lookup)) {
1031                                 symname = symbol_name(ef, rel->r_info);
1032                                 printf("link_elf_obj: symbol %s undefined\n",
1033                                     symname);
1034                                 return ENOENT;
1035                         }
1036                 }
1037         }
1038
1039         /* Perform relocations with addend if there are any: */
1040         for (i = 0; i < ef->nrelatab; i++) {
1041                 rela = ef->relatab[i].rela;
1042                 if (rela == NULL)
1043                         panic("lost a relatab!");
1044                 relalim = rela + ef->relatab[i].nrela;
1045                 base = findbase(ef, ef->relatab[i].sec);
1046                 if (base == 0)
1047                         panic("lost base for relatab");
1048                 for ( ; rela < relalim; rela++) {
1049                         symidx = ELF_R_SYM(rela->r_info);
1050                         if (symidx >= ef->ddbsymcnt)
1051                                 continue;
1052                         sym = ef->ddbsymtab + symidx;
1053                         /* Local relocs are already done */
1054                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1055                                 continue;
1056                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1057                             elf_obj_lookup)) {
1058                                 symname = symbol_name(ef, rela->r_info);
1059                                 printf("link_elf_obj: symbol %s undefined\n",
1060                                     symname);
1061                                 return ENOENT;
1062                         }
1063                 }
1064         }
1065
1066         return 0;
1067 }
1068
1069 static int
1070 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1071 {
1072         elf_file_t ef = (elf_file_t) lf;
1073         const Elf_Sym *symp;
1074         const char *strp;
1075         int i;
1076
1077         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1078                 strp = ef->ddbstrtab + symp->st_name;
1079                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1080                         *sym = (c_linker_sym_t) symp;
1081                         return 0;
1082                 }
1083         }
1084         return ENOENT;
1085 }
1086
1087 static int
1088 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1089     linker_symval_t *symval)
1090 {
1091         elf_file_t ef = (elf_file_t) lf;
1092         const Elf_Sym *es = (const Elf_Sym*) sym;
1093
1094         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1095                 symval->name = ef->ddbstrtab + es->st_name;
1096                 symval->value = (caddr_t)es->st_value;
1097                 symval->size = es->st_size;
1098                 return 0;
1099         }
1100         return ENOENT;
1101 }
1102
1103 static int
1104 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1105     c_linker_sym_t *sym, long *diffp)
1106 {
1107         elf_file_t ef = (elf_file_t) lf;
1108         u_long off = (uintptr_t) (void *) value;
1109         u_long diff = off;
1110         u_long st_value;
1111         const Elf_Sym *es;
1112         const Elf_Sym *best = 0;
1113         int i;
1114
1115         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1116                 if (es->st_name == 0)
1117                         continue;
1118                 st_value = es->st_value;
1119                 if (off >= st_value) {
1120                         if (off - st_value < diff) {
1121                                 diff = off - st_value;
1122                                 best = es;
1123                                 if (diff == 0)
1124                                         break;
1125                         } else if (off - st_value == diff) {
1126                                 best = es;
1127                         }
1128                 }
1129         }
1130         if (best == 0)
1131                 *diffp = off;
1132         else
1133                 *diffp = diff;
1134         *sym = (c_linker_sym_t) best;
1135
1136         return 0;
1137 }
1138
1139 /*
1140  * Look up a linker set on an ELF system.
1141  */
1142 static int
1143 link_elf_lookup_set(linker_file_t lf, const char *name,
1144     void ***startp, void ***stopp, int *countp)
1145 {
1146         elf_file_t ef = (elf_file_t)lf;
1147         void **start, **stop;
1148         int i, count;
1149
1150         /* Relative to section number */
1151         for (i = 0; i < ef->nprogtab; i++) {
1152                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1153                     strcmp(ef->progtab[i].name + 4, name) == 0) {
1154                         start  = (void **)ef->progtab[i].addr;
1155                         stop = (void **)((char *)ef->progtab[i].addr +
1156                             ef->progtab[i].size);
1157                         count = stop - start;
1158                         if (startp)
1159                                 *startp = start;
1160                         if (stopp)
1161                                 *stopp = stop;
1162                         if (countp)
1163                                 *countp = count;
1164                         return (0);
1165                 }
1166         }
1167         return (ESRCH);
1168 }
1169
1170 static int
1171 link_elf_each_function_name(linker_file_t file,
1172     int (*callback)(const char *, void *), void *opaque)
1173 {
1174         elf_file_t ef = (elf_file_t)file;
1175         const Elf_Sym *symp;
1176         int i, error;
1177
1178         /* Exhaustive search */
1179         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1180                 if (symp->st_value != 0 &&
1181                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1182                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
1183                         if (error)
1184                                 return (error);
1185                 }
1186         }
1187         return (0);
1188 }
1189
1190 static int
1191 link_elf_each_function_nameval(linker_file_t file,
1192     linker_function_nameval_callback_t callback, void *opaque)
1193 {
1194         linker_symval_t symval;
1195         elf_file_t ef = (elf_file_t)file;
1196         const Elf_Sym* symp;
1197         int i, error;
1198
1199         /* Exhaustive search */
1200         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1201                 if (symp->st_value != 0 &&
1202                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1203                         error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1204                         if (error)
1205                                 return (error);
1206                         error = callback(file, i, &symval, opaque);
1207                         if (error)
1208                                 return (error);
1209                 }
1210         }
1211         return (0);
1212 }
1213
1214 /*
1215  * Symbol lookup function that can be used when the symbol index is known (ie
1216  * in relocations). It uses the symbol index instead of doing a fully fledged
1217  * hash table based lookup when such is valid. For example for local symbols.
1218  * This is not only more efficient, it's also more correct. It's not always
1219  * the case that the symbol can be found through the hash table.
1220  */
1221 static Elf_Addr
1222 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1223 {
1224         elf_file_t ef = (elf_file_t)lf;
1225         const Elf_Sym *sym;
1226         const char *symbol;
1227         Elf_Addr ret;
1228
1229         /* Don't even try to lookup the symbol if the index is bogus. */
1230         if (symidx >= ef->ddbsymcnt)
1231                 return (0);
1232
1233         sym = ef->ddbsymtab + symidx;
1234
1235         /* Quick answer if there is a definition included. */
1236         if (sym->st_shndx != SHN_UNDEF)
1237                 return (sym->st_value);
1238
1239         /* If we get here, then it is undefined and needs a lookup. */
1240         switch (ELF_ST_BIND(sym->st_info)) {
1241         case STB_LOCAL:
1242                 /* Local, but undefined? huh? */
1243                 return (0);
1244
1245         case STB_GLOBAL:
1246                 /* Relative to Data or Function name */
1247                 symbol = ef->ddbstrtab + sym->st_name;
1248
1249                 /* Force a lookup failure if the symbol name is bogus. */
1250                 if (*symbol == 0)
1251                         return (0);
1252                 ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1253                 return ret;
1254
1255         case STB_WEAK:
1256                 printf("link_elf_obj: Weak symbols not supported\n");
1257                 return (0);
1258
1259         default:
1260                 return (0);
1261         }
1262 }
1263
1264 static void
1265 link_elf_fix_link_set(elf_file_t ef)
1266 {
1267         static const char startn[] = "__start_";
1268         static const char stopn[] = "__stop_";
1269         Elf_Sym *sym;
1270         const char *sym_name, *linkset_name;
1271         Elf_Addr startp, stopp;
1272         Elf_Size symidx;
1273         int start, i;
1274
1275         startp = stopp = 0;
1276         for (symidx = 1 /* zero entry is special */;
1277                 symidx < ef->ddbsymcnt; symidx++) {
1278                 sym = ef->ddbsymtab + symidx;
1279                 if (sym->st_shndx != SHN_UNDEF)
1280                         continue;
1281
1282                 sym_name = ef->ddbstrtab + sym->st_name;
1283                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1284                         start = 1;
1285                         linkset_name = sym_name + sizeof(startn) - 1;
1286                 }
1287                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1288                         start = 0;
1289                         linkset_name = sym_name + sizeof(stopn) - 1;
1290                 }
1291                 else
1292                         continue;
1293
1294                 for (i = 0; i < ef->nprogtab; i++) {
1295                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1296                                 startp = (Elf_Addr)ef->progtab[i].addr;
1297                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1298                                 break;
1299                         }
1300                 }
1301                 if (i == ef->nprogtab)
1302                         continue;
1303
1304                 sym->st_value = start ? startp : stopp;
1305                 sym->st_shndx = i;
1306         }
1307 }
1308
1309 static void
1310 link_elf_reloc_local(linker_file_t lf)
1311 {
1312         elf_file_t ef = (elf_file_t)lf;
1313         const Elf_Rel *rellim;
1314         const Elf_Rel *rel;
1315         const Elf_Rela *relalim;
1316         const Elf_Rela *rela;
1317         const Elf_Sym *sym;
1318         Elf_Addr base;
1319         int i;
1320         Elf_Size symidx;
1321
1322         link_elf_fix_link_set(ef);
1323
1324         /* Perform relocations without addend if there are any: */
1325         for (i = 0; i < ef->nreltab; i++) {
1326                 rel = ef->reltab[i].rel;
1327                 if (rel == NULL)
1328                         panic("lost a reltab!");
1329                 rellim = rel + ef->reltab[i].nrel;
1330                 base = findbase(ef, ef->reltab[i].sec);
1331                 if (base == 0)
1332                         panic("lost base for reltab");
1333                 for ( ; rel < rellim; rel++) {
1334                         symidx = ELF_R_SYM(rel->r_info);
1335                         if (symidx >= ef->ddbsymcnt)
1336                                 continue;
1337                         sym = ef->ddbsymtab + symidx;
1338                         /* Only do local relocs */
1339                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1340                                 continue;
1341                         elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1342                             elf_obj_lookup);
1343                 }
1344         }
1345
1346         /* Perform relocations with addend if there are any: */
1347         for (i = 0; i < ef->nrelatab; i++) {
1348                 rela = ef->relatab[i].rela;
1349                 if (rela == NULL)
1350                         panic("lost a relatab!");
1351                 relalim = rela + ef->relatab[i].nrela;
1352                 base = findbase(ef, ef->relatab[i].sec);
1353                 if (base == 0)
1354                         panic("lost base for relatab");
1355                 for ( ; rela < relalim; rela++) {
1356                         symidx = ELF_R_SYM(rela->r_info);
1357                         if (symidx >= ef->ddbsymcnt)
1358                                 continue;
1359                         sym = ef->ddbsymtab + symidx;
1360                         /* Only do local relocs */
1361                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1362                                 continue;
1363                         elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1364                             elf_obj_lookup);
1365                 }
1366         }
1367 }
1368
1369 static long
1370 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1371 {
1372     elf_file_t ef = (elf_file_t)lf;
1373
1374     *symtab = ef->ddbsymtab;
1375
1376     if (*symtab == NULL)
1377         return (0);
1378
1379     return (ef->ddbsymcnt);
1380 }
1381
1382 static long
1383 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1384 {
1385     elf_file_t ef = (elf_file_t)lf;
1386
1387     *strtab = ef->ddbstrtab;
1388
1389     if (*strtab == NULL)
1390         return (0);
1391
1392     return (ef->ddbstrcnt);
1393 }