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, DPCPU_SETNAME)) {
 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         ssize_t resid;
 444         int flags;
 445         elf_file_t ef;
 446         linker_file_t lf;
 447         int symtabindex;
 448         int symstrindex;
 449         int shstrindex;
 450         int nsym;
 451         int pb, rl, ra;
 452         int alignmask;
 453
 454         shdr = NULL;
 455         lf = NULL;
 456         mapsize = 0;
 457         hdr = NULL;
 458
 459         NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
 460         flags = FREAD;
 461         error = vn_open(&nd, &flags, 0, NULL);
 462         if (error)
 463                 return error;
 464         NDFREE(&nd, NDF_ONLY_PNBUF);
 465         if (nd.ni_vp->v_type != VREG) {
 466                 error = ENOEXEC;
 467                 goto out;
 468         }
 469 #ifdef MAC
 470         error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
 471         if (error) {
 472                 goto out;
 473         }
 474 #endif
 475
 476         /* Read the elf header from the file. */
 477         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
 478         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
 479             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 480             &resid, td);
 481         if (error)
 482                 goto out;
 483         if (resid != 0){
 484                 error = ENOEXEC;
 485                 goto out;
 486         }
 487
 488         if (!IS_ELF(*hdr)) {
 489                 error = ENOEXEC;
 490                 goto out;
 491         }
 492
 493         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
 494             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
 495                 link_elf_error(filename, "Unsupported file layout");
 496                 error = ENOEXEC;
 497                 goto out;
 498         }
 499         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
 500             || hdr->e_version != EV_CURRENT) {
 501                 link_elf_error(filename, "Unsupported file version");
 502                 error = ENOEXEC;
 503                 goto out;
 504         }
 505         if (hdr->e_type != ET_REL) {
 506                 error = ENOSYS;
 507                 goto out;
 508         }
 509         if (hdr->e_machine != ELF_TARG_MACH) {
 510                 link_elf_error(filename, "Unsupported machine");
 511                 error = ENOEXEC;
 512                 goto out;
 513         }
 514
 515         lf = linker_make_file(filename, &link_elf_class);
 516         if (!lf) {
 517                 error = ENOMEM;
 518                 goto out;
 519         }
 520         ef = (elf_file_t) lf;
 521         ef->nprogtab = 0;
 522         ef->e_shdr = 0;
 523         ef->nreltab = 0;
 524         ef->nrelatab = 0;
 525
 526         /* Allocate and read in the section header */
 527         nbytes = hdr->e_shnum * hdr->e_shentsize;
 528         if (nbytes == 0 || hdr->e_shoff == 0 ||
 529             hdr->e_shentsize != sizeof(Elf_Shdr)) {
 530                 error = ENOEXEC;
 531                 goto out;
 532         }
 533         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
 534         ef->e_shdr = shdr;
 535         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
 536             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
 537         if (error)
 538                 goto out;
 539         if (resid) {
 540                 error = ENOEXEC;
 541                 goto out;
 542         }
 543
 544         /* Scan the section header for information and table sizing. */
 545         nsym = 0;
 546         symtabindex = -1;
 547         symstrindex = -1;
 548         for (i = 0; i < hdr->e_shnum; i++) {
 549                 if (shdr[i].sh_size == 0)
 550                         continue;
 551                 switch (shdr[i].sh_type) {
 552                 case SHT_PROGBITS:
 553                 case SHT_NOBITS:
 554                         ef->nprogtab++;
 555                         break;
 556                 case SHT_SYMTAB:
 557                         nsym++;
 558                         symtabindex = i;
 559                         symstrindex = shdr[i].sh_link;
 560                         break;
 561                 case SHT_REL:
 562                         ef->nreltab++;
 563                         break;
 564                 case SHT_RELA:
 565                         ef->nrelatab++;
 566                         break;
 567                 case SHT_STRTAB:
 568                         break;
 569                 }
 570         }
 571         if (ef->nprogtab == 0) {
 572                 link_elf_error(filename, "file has no contents");
 573                 error = ENOEXEC;
 574                 goto out;
 575         }
 576         if (nsym != 1) {
 577                 /* Only allow one symbol table for now */
 578                 link_elf_error(filename, "file has no valid symbol table");
 579                 error = ENOEXEC;
 580                 goto out;
 581         }
 582         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
 583             shdr[symstrindex].sh_type != SHT_STRTAB) {
 584                 link_elf_error(filename, "file has invalid symbol strings");
 585                 error = ENOEXEC;
 586                 goto out;
 587         }
 588
 589         /* Allocate space for tracking the load chunks */
 590         if (ef->nprogtab != 0)
 591                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 592                     M_LINKER, M_WAITOK | M_ZERO);
 593         if (ef->nreltab != 0)
 594                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 595                     M_LINKER, M_WAITOK | M_ZERO);
 596         if (ef->nrelatab != 0)
 597                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 598                     M_LINKER, M_WAITOK | M_ZERO);
 599
 600         if (symtabindex == -1)
 601                 panic("lost symbol table index");
 602         /* Allocate space for and load the symbol table */
 603         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 604         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
 605         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
 606             shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
 607             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 608             &resid, td);
 609         if (error)
 610                 goto out;
 611         if (resid != 0){
 612                 error = EINVAL;
 613                 goto out;
 614         }
 615
 616         if (symstrindex == -1)
 617                 panic("lost symbol string index");
 618         /* Allocate space for and load the symbol strings */
 619         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 620         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
 621         error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
 622             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
 623             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 624             &resid, td);
 625         if (error)
 626                 goto out;
 627         if (resid != 0){
 628                 error = EINVAL;
 629                 goto out;
 630         }
 631
 632         /* Do we have a string table for the section names?  */
 633         shstrindex = -1;
 634         if (hdr->e_shstrndx != 0 &&
 635             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
 636                 shstrindex = hdr->e_shstrndx;
 637                 ef->shstrcnt = shdr[shstrindex].sh_size;
 638                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
 639                     M_WAITOK);
 640                 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
 641                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
 642                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 643                     &resid, td);
 644                 if (error)
 645                         goto out;
 646                 if (resid != 0){
 647                         error = EINVAL;
 648                         goto out;
 649                 }
 650         }
 651
 652         /* Size up code/data(progbits) and bss(nobits). */
 653         alignmask = 0;
 654         for (i = 0; i < hdr->e_shnum; i++) {
 655                 if (shdr[i].sh_size == 0)
 656                         continue;
 657                 switch (shdr[i].sh_type) {
 658                 case SHT_PROGBITS:
 659                 case SHT_NOBITS:
 660                         alignmask = shdr[i].sh_addralign - 1;
 661                         mapsize += alignmask;
 662                         mapsize &= ~alignmask;
 663                         mapsize += shdr[i].sh_size;
 664                         break;
 665                 }
 666         }
 667
 668         /*
 669          * We know how much space we need for the text/data/bss/etc.
 670          * This stuff needs to be in a single chunk so that profiling etc
 671          * can get the bounds and gdb can associate offsets with modules
 672          */
 673         ef->object = vm_object_allocate(OBJT_DEFAULT,
 674             round_page(mapsize) >> PAGE_SHIFT);
 675         if (ef->object == NULL) {
 676                 error = ENOMEM;
 677                 goto out;
 678         }
 679         ef->address = (caddr_t) vm_map_min(kernel_map);
 680
 681         /*
 682          * In order to satisfy amd64's architectural requirements on the
 683          * location of code and data in the kernel's address space, request a
 684          * mapping that is above the kernel.
 685          */
 686 #ifdef __amd64__
 687         mapbase = KERNBASE;
 688 #else
 689         mapbase = VM_MIN_KERNEL_ADDRESS;
 690 #endif
 691         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
 692             round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
 693             VM_PROT_ALL, 0);
 694         if (error) {
 695                 vm_object_deallocate(ef->object);
 696                 ef->object = 0;
 697                 goto out;
 698         }
 699
 700         /* Wire the pages */
 701         error = vm_map_wire(kernel_map, mapbase,
 702             mapbase + round_page(mapsize),
 703             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 704         if (error != KERN_SUCCESS) {
 705                 error = ENOMEM;
 706                 goto out;
 707         }
 708
 709         /* Inform the kld system about the situation */
 710         lf->address = ef->address = (caddr_t)mapbase;
 711         lf->size = mapsize;
 712
 713         /*
 714          * Now load code/data(progbits), zero bss(nobits), allocate space for
 715          * and load relocs
 716          */
 717         pb = 0;
 718         rl = 0;
 719         ra = 0;
 720         alignmask = 0;
 721         for (i = 0; i < hdr->e_shnum; i++) {
 722                 if (shdr[i].sh_size == 0)
 723                         continue;
 724                 switch (shdr[i].sh_type) {
 725                 case SHT_PROGBITS:
 726                 case SHT_NOBITS:
 727                         alignmask = shdr[i].sh_addralign - 1;
 728                         mapbase += alignmask;
 729                         mapbase &= ~alignmask;
 730                         if (ef->shstrtab && shdr[i].sh_name != 0)
 731                                 ef->progtab[pb].name =
 732                                     ef->shstrtab + shdr[i].sh_name;
 733                         else if (shdr[i].sh_type == SHT_PROGBITS)
 734                                 ef->progtab[pb].name = "<<PROGBITS>>";
 735                         else
 736                                 ef->progtab[pb].name = "<<NOBITS>>";
 737                         if (ef->progtab[pb].name != NULL &&
 738                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 739                                 ef->progtab[pb].addr =
 740                                     dpcpu_alloc(shdr[i].sh_size);
 741 #ifdef VIMAGE
 742                         else if (ef->progtab[pb].name != NULL &&
 743                             !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 744                                 ef->progtab[pb].addr =
 745                                     vnet_data_alloc(shdr[i].sh_size);
 746 #endif
 747                         else
 748                                 ef->progtab[pb].addr =
 749                                     (void *)(uintptr_t)mapbase;
 750                         if (ef->progtab[pb].addr == NULL) {
 751                                 error = ENOSPC;
 752                                 goto out;
 753                         }
 754                         ef->progtab[pb].size = shdr[i].sh_size;
 755                         ef->progtab[pb].sec = i;
 756                         if (shdr[i].sh_type == SHT_PROGBITS) {
 757                                 error = vn_rdwr(UIO_READ, nd.ni_vp,
 758                                     ef->progtab[pb].addr,
 759                                     shdr[i].sh_size, shdr[i].sh_offset,
 760                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
 761                                     NOCRED, &resid, td);
 762                                 if (error)
 763                                         goto out;
 764                                 if (resid != 0){
 765                                         error = EINVAL;
 766                                         goto out;
 767                                 }
 768                                 /* Initialize the per-cpu or vnet area. */
 769                                 if (ef->progtab[pb].addr != (void *)mapbase &&
 770                                     !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 771                                         dpcpu_copy(ef->progtab[pb].addr,
 772                                             shdr[i].sh_size);
 773 #ifdef VIMAGE
 774                                 else if (ef->progtab[pb].addr !=
 775                                     (void *)mapbase &&
 776                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 777                                         vnet_data_copy(ef->progtab[pb].addr,
 778                                             shdr[i].sh_size);
 779 #endif
 780                         } else
 781                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
 782
 783                         /* Update all symbol values with the offset. */
 784                         for (j = 0; j < ef->ddbsymcnt; j++) {
 785                                 es = &ef->ddbsymtab[j];
 786                                 if (es->st_shndx != i)
 787                                         continue;
 788                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 789                         }
 790                         mapbase += shdr[i].sh_size;
 791                         pb++;
 792                         break;
 793                 case SHT_REL:
 794                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
 795                             M_WAITOK);
 796                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 797                         ef->reltab[rl].sec = shdr[i].sh_info;
 798                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 799                             (void *)ef->reltab[rl].rel,
 800                             shdr[i].sh_size, shdr[i].sh_offset,
 801                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 802                             &resid, td);
 803                         if (error)
 804                                 goto out;
 805                         if (resid != 0){
 806                                 error = EINVAL;
 807                                 goto out;
 808                         }
 809                         rl++;
 810                         break;
 811                 case SHT_RELA:
 812                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
 813                             M_WAITOK);
 814                         ef->relatab[ra].nrela =
 815                             shdr[i].sh_size / sizeof(Elf_Rela);
 816                         ef->relatab[ra].sec = shdr[i].sh_info;
 817                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 818                             (void *)ef->relatab[ra].rela,
 819                             shdr[i].sh_size, shdr[i].sh_offset,
 820                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 821                             &resid, td);
 822                         if (error)
 823                                 goto out;
 824                         if (resid != 0){
 825                                 error = EINVAL;
 826                                 goto out;
 827                         }
 828                         ra++;
 829                         break;
 830                 }
 831         }
 832         if (pb != ef->nprogtab)
 833                 panic("lost progbits");
 834         if (rl != ef->nreltab)
 835                 panic("lost reltab");
 836         if (ra != ef->nrelatab)
 837                 panic("lost relatab");
 838         if (mapbase != (vm_offset_t)ef->address + mapsize)
 839                 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
 840                     (u_long)mapbase, ef->address, (u_long)mapsize,
 841                     (u_long)(vm_offset_t)ef->address + mapsize);
 842
 843         /* Local intra-module relocations */
 844         link_elf_reloc_local(lf);
 845
 846         /* Pull in dependencies */
 847         VOP_UNLOCK(nd.ni_vp, 0);
 848         error = linker_load_dependencies(lf);
 849         vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
 850         if (error)
 851                 goto out;
 852
 853         /* External relocations */
 854         error = relocate_file(ef);
 855         if (error)
 856                 goto out;
 857
 858         /* Notify MD code that a module is being loaded. */
 859         error = elf_cpu_load_file(lf);
 860         if (error)
 861                 goto out;
 862
 863         *result = lf;
 864
 865 out:
 866         VOP_UNLOCK(nd.ni_vp, 0);
 867         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
 868         if (error && lf)
 869                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 870         if (hdr)
 871                 free(hdr, M_LINKER);
 872
 873         return error;
 874 }
 875
 876 static void
 877 link_elf_unload_file(linker_file_t file)
 878 {
 879         elf_file_t ef = (elf_file_t) file;
 880         int i;
 881
 882         /* Notify MD code that a module is being unloaded. */
 883         elf_cpu_unload_file(file);
 884
 885         if (ef->progtab) {
 886                 for (i = 0; i < ef->nprogtab; i++) {
 887                         if (ef->progtab[i].size == 0)
 888                                 continue;
 889                         if (ef->progtab[i].name == NULL)
 890                                 continue;
 891                         if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
 892                                 dpcpu_free(ef->progtab[i].addr,
 893                                     ef->progtab[i].size);
 894 #ifdef VIMAGE
 895                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
 896                                 vnet_data_free(ef->progtab[i].addr,
 897                                     ef->progtab[i].size);
 898 #endif
 899                 }
 900         }
 901         if (ef->preloaded) {
 902                 if (ef->reltab)
 903                         free(ef->reltab, M_LINKER);
 904                 if (ef->relatab)
 905                         free(ef->relatab, M_LINKER);
 906                 if (ef->progtab)
 907                         free(ef->progtab, M_LINKER);
 908                 if (ef->ctftab)
 909                         free(ef->ctftab, M_LINKER);
 910                 if (ef->ctfoff)
 911                         free(ef->ctfoff, M_LINKER);
 912                 if (ef->typoff)
 913                         free(ef->typoff, M_LINKER);
 914                 if (file->filename != NULL)
 915                         preload_delete_name(file->filename);
 916                 /* XXX reclaim module memory? */
 917                 return;
 918         }
 919
 920         for (i = 0; i < ef->nreltab; i++)
 921                 if (ef->reltab[i].rel)
 922                         free(ef->reltab[i].rel, M_LINKER);
 923         for (i = 0; i < ef->nrelatab; i++)
 924                 if (ef->relatab[i].rela)
 925                         free(ef->relatab[i].rela, M_LINKER);
 926         if (ef->reltab)
 927                 free(ef->reltab, M_LINKER);
 928         if (ef->relatab)
 929                 free(ef->relatab, M_LINKER);
 930         if (ef->progtab)
 931                 free(ef->progtab, M_LINKER);
 932
 933         if (ef->object) {
 934                 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
 935                     (vm_offset_t) ef->address +
 936                     (ef->object->size << PAGE_SHIFT));
 937         }
 938         if (ef->e_shdr)
 939                 free(ef->e_shdr, M_LINKER);
 940         if (ef->ddbsymtab)
 941                 free(ef->ddbsymtab, M_LINKER);
 942         if (ef->ddbstrtab)
 943                 free(ef->ddbstrtab, M_LINKER);
 944         if (ef->shstrtab)
 945                 free(ef->shstrtab, M_LINKER);
 946         if (ef->ctftab)
 947                 free(ef->ctftab, M_LINKER);
 948         if (ef->ctfoff)
 949                 free(ef->ctfoff, M_LINKER);
 950         if (ef->typoff)
 951                 free(ef->typoff, M_LINKER);
 952 }
 953
 954 static const char *
 955 symbol_name(elf_file_t ef, Elf_Size r_info)
 956 {
 957         const Elf_Sym *ref;
 958
 959         if (ELF_R_SYM(r_info)) {
 960                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
 961                 return ef->ddbstrtab + ref->st_name;
 962         } else
 963                 return NULL;
 964 }
 965
 966 static Elf_Addr
 967 findbase(elf_file_t ef, int sec)
 968 {
 969         int i;
 970         Elf_Addr base = 0;
 971
 972         for (i = 0; i < ef->nprogtab; i++) {
 973                 if (sec == ef->progtab[i].sec) {
 974                         base = (Elf_Addr)ef->progtab[i].addr;
 975                         break;
 976                 }
 977         }
 978         return base;
 979 }
 980
 981 static int
 982 relocate_file(elf_file_t ef)
 983 {
 984         const Elf_Rel *rellim;
 985         const Elf_Rel *rel;
 986         const Elf_Rela *relalim;
 987         const Elf_Rela *rela;
 988         const char *symname;
 989         const Elf_Sym *sym;
 990         int i;
 991         Elf_Size symidx;
 992         Elf_Addr base;
 993
 994
 995         /* Perform relocations without addend if there are any: */
 996         for (i = 0; i < ef->nreltab; i++) {
 997                 rel = ef->reltab[i].rel;
 998                 if (rel == NULL)
 999                         panic("lost a reltab!");
1000                 rellim = rel + ef->reltab[i].nrel;
1001                 base = findbase(ef, ef->reltab[i].sec);
1002                 if (base == 0)
1003                         panic("lost base for reltab");
1004                 for ( ; rel < rellim; rel++) {
1005                         symidx = ELF_R_SYM(rel->r_info);
1006                         if (symidx >= ef->ddbsymcnt)
1007                                 continue;
1008                         sym = ef->ddbsymtab + symidx;
1009                         /* Local relocs are already done */
1010                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1011                                 continue;
1012                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1013                             elf_obj_lookup)) {
1014                                 symname = symbol_name(ef, rel->r_info);
1015                                 printf("link_elf_obj: symbol %s undefined\n",
1016                                     symname);
1017                                 return ENOENT;
1018                         }
1019                 }
1020         }
1021
1022         /* Perform relocations with addend if there are any: */
1023         for (i = 0; i < ef->nrelatab; i++) {
1024                 rela = ef->relatab[i].rela;
1025                 if (rela == NULL)
1026                         panic("lost a relatab!");
1027                 relalim = rela + ef->relatab[i].nrela;
1028                 base = findbase(ef, ef->relatab[i].sec);
1029                 if (base == 0)
1030                         panic("lost base for relatab");
1031                 for ( ; rela < relalim; rela++) {
1032                         symidx = ELF_R_SYM(rela->r_info);
1033                         if (symidx >= ef->ddbsymcnt)
1034                                 continue;
1035                         sym = ef->ddbsymtab + symidx;
1036                         /* Local relocs are already done */
1037                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1038                                 continue;
1039                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1040                             elf_obj_lookup)) {
1041                                 symname = symbol_name(ef, rela->r_info);
1042                                 printf("link_elf_obj: symbol %s undefined\n",
1043                                     symname);
1044                                 return ENOENT;
1045                         }
1046                 }
1047         }
1048
1049         return 0;
1050 }
1051
1052 static int
1053 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1054 {
1055         elf_file_t ef = (elf_file_t) lf;
1056         const Elf_Sym *symp;
1057         const char *strp;
1058         int i;
1059
1060         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1061                 strp = ef->ddbstrtab + symp->st_name;
1062                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1063                         *sym = (c_linker_sym_t) symp;
1064                         return 0;
1065                 }
1066         }
1067         return ENOENT;
1068 }
1069
1070 static int
1071 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1072     linker_symval_t *symval)
1073 {
1074         elf_file_t ef = (elf_file_t) lf;
1075         const Elf_Sym *es = (const Elf_Sym*) sym;
1076
1077         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1078                 symval->name = ef->ddbstrtab + es->st_name;
1079                 symval->value = (caddr_t)es->st_value;
1080                 symval->size = es->st_size;
1081                 return 0;
1082         }
1083         return ENOENT;
1084 }
1085
1086 static int
1087 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1088     c_linker_sym_t *sym, long *diffp)
1089 {
1090         elf_file_t ef = (elf_file_t) lf;
1091         u_long off = (uintptr_t) (void *) value;
1092         u_long diff = off;
1093         u_long st_value;
1094         const Elf_Sym *es;
1095         const Elf_Sym *best = 0;
1096         int i;
1097
1098         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1099                 if (es->st_name == 0)
1100                         continue;
1101                 st_value = es->st_value;
1102                 if (off >= st_value) {
1103                         if (off - st_value < diff) {
1104                                 diff = off - st_value;
1105                                 best = es;
1106                                 if (diff == 0)
1107                                         break;
1108                         } else if (off - st_value == diff) {
1109                                 best = es;
1110                         }
1111                 }
1112         }
1113         if (best == 0)
1114                 *diffp = off;
1115         else
1116                 *diffp = diff;
1117         *sym = (c_linker_sym_t) best;
1118
1119         return 0;
1120 }
1121
1122 /*
1123  * Look up a linker set on an ELF system.
1124  */
1125 static int
1126 link_elf_lookup_set(linker_file_t lf, const char *name,
1127     void ***startp, void ***stopp, int *countp)
1128 {
1129         elf_file_t ef = (elf_file_t)lf;
1130         void **start, **stop;
1131         int i, count;
1132
1133         /* Relative to section number */
1134         for (i = 0; i < ef->nprogtab; i++) {
1135                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1136                     strcmp(ef->progtab[i].name + 4, name) == 0) {
1137                         start  = (void **)ef->progtab[i].addr;
1138                         stop = (void **)((char *)ef->progtab[i].addr +
1139                             ef->progtab[i].size);
1140                         count = stop - start;
1141                         if (startp)
1142                                 *startp = start;
1143                         if (stopp)
1144                                 *stopp = stop;
1145                         if (countp)
1146                                 *countp = count;
1147                         return (0);
1148                 }
1149         }
1150         return (ESRCH);
1151 }
1152
1153 static int
1154 link_elf_each_function_name(linker_file_t file,
1155     int (*callback)(const char *, void *), void *opaque)
1156 {
1157         elf_file_t ef = (elf_file_t)file;
1158         const Elf_Sym *symp;
1159         int i, error;
1160
1161         /* Exhaustive search */
1162         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1163                 if (symp->st_value != 0 &&
1164                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1165                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
1166                         if (error)
1167                                 return (error);
1168                 }
1169         }
1170         return (0);
1171 }
1172
1173 static int
1174 link_elf_each_function_nameval(linker_file_t file,
1175     linker_function_nameval_callback_t callback, void *opaque)
1176 {
1177         linker_symval_t symval;
1178         elf_file_t ef = (elf_file_t)file;
1179         const Elf_Sym* symp;
1180         int i, error;
1181
1182         /* Exhaustive search */
1183         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1184                 if (symp->st_value != 0 &&
1185                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1186                         error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1187                         if (error)
1188                                 return (error);
1189                         error = callback(file, i, &symval, opaque);
1190                         if (error)
1191                                 return (error);
1192                 }
1193         }
1194         return (0);
1195 }
1196
1197 /*
1198  * Symbol lookup function that can be used when the symbol index is known (ie
1199  * in relocations). It uses the symbol index instead of doing a fully fledged
1200  * hash table based lookup when such is valid. For example for local symbols.
1201  * This is not only more efficient, it's also more correct. It's not always
1202  * the case that the symbol can be found through the hash table.
1203  */
1204 static Elf_Addr
1205 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1206 {
1207         elf_file_t ef = (elf_file_t)lf;
1208         const Elf_Sym *sym;
1209         const char *symbol;
1210         Elf_Addr ret;
1211
1212         /* Don't even try to lookup the symbol if the index is bogus. */
1213         if (symidx >= ef->ddbsymcnt)
1214                 return (0);
1215
1216         sym = ef->ddbsymtab + symidx;
1217
1218         /* Quick answer if there is a definition included. */
1219         if (sym->st_shndx != SHN_UNDEF)
1220                 return (sym->st_value);
1221
1222         /* If we get here, then it is undefined and needs a lookup. */
1223         switch (ELF_ST_BIND(sym->st_info)) {
1224         case STB_LOCAL:
1225                 /* Local, but undefined? huh? */
1226                 return (0);
1227
1228         case STB_GLOBAL:
1229                 /* Relative to Data or Function name */
1230                 symbol = ef->ddbstrtab + sym->st_name;
1231
1232                 /* Force a lookup failure if the symbol name is bogus. */
1233                 if (*symbol == 0)
1234                         return (0);
1235                 ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1236                 return ret;
1237
1238         case STB_WEAK:
1239                 printf("link_elf_obj: Weak symbols not supported\n");
1240                 return (0);
1241
1242         default:
1243                 return (0);
1244         }
1245 }
1246
1247 static void
1248 link_elf_fix_link_set(elf_file_t ef)
1249 {
1250         static const char startn[] = "__start_";
1251         static const char stopn[] = "__stop_";
1252         Elf_Sym *sym;
1253         const char *sym_name, *linkset_name;
1254         Elf_Addr startp, stopp;
1255         Elf_Size symidx;
1256         int start, i;
1257
1258         startp = stopp = 0;
1259         for (symidx = 1 /* zero entry is special */;
1260                 symidx < ef->ddbsymcnt; symidx++) {
1261                 sym = ef->ddbsymtab + symidx;
1262                 if (sym->st_shndx != SHN_UNDEF)
1263                         continue;
1264
1265                 sym_name = ef->ddbstrtab + sym->st_name;
1266                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1267                         start = 1;
1268                         linkset_name = sym_name + sizeof(startn) - 1;
1269                 }
1270                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1271                         start = 0;
1272                         linkset_name = sym_name + sizeof(stopn) - 1;
1273                 }
1274                 else
1275                         continue;
1276
1277                 for (i = 0; i < ef->nprogtab; i++) {
1278                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1279                                 startp = (Elf_Addr)ef->progtab[i].addr;
1280                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1281                                 break;
1282                         }
1283                 }
1284                 if (i == ef->nprogtab)
1285                         continue;
1286
1287                 sym->st_value = start ? startp : stopp;
1288                 sym->st_shndx = i;
1289         }
1290 }
1291
1292 static void
1293 link_elf_reloc_local(linker_file_t lf)
1294 {
1295         elf_file_t ef = (elf_file_t)lf;
1296         const Elf_Rel *rellim;
1297         const Elf_Rel *rel;
1298         const Elf_Rela *relalim;
1299         const Elf_Rela *rela;
1300         const Elf_Sym *sym;
1301         Elf_Addr base;
1302         int i;
1303         Elf_Size symidx;
1304
1305         link_elf_fix_link_set(ef);
1306
1307         /* Perform relocations without addend if there are any: */
1308         for (i = 0; i < ef->nreltab; i++) {
1309                 rel = ef->reltab[i].rel;
1310                 if (rel == NULL)
1311                         panic("lost a reltab!");
1312                 rellim = rel + ef->reltab[i].nrel;
1313                 base = findbase(ef, ef->reltab[i].sec);
1314                 if (base == 0)
1315                         panic("lost base for reltab");
1316                 for ( ; rel < rellim; rel++) {
1317                         symidx = ELF_R_SYM(rel->r_info);
1318                         if (symidx >= ef->ddbsymcnt)
1319                                 continue;
1320                         sym = ef->ddbsymtab + symidx;
1321                         /* Only do local relocs */
1322                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1323                                 continue;
1324                         elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1325                             elf_obj_lookup);
1326                 }
1327         }
1328
1329         /* Perform relocations with addend if there are any: */
1330         for (i = 0; i < ef->nrelatab; i++) {
1331                 rela = ef->relatab[i].rela;
1332                 if (rela == NULL)
1333                         panic("lost a relatab!");
1334                 relalim = rela + ef->relatab[i].nrela;
1335                 base = findbase(ef, ef->relatab[i].sec);
1336                 if (base == 0)
1337                         panic("lost base for relatab");
1338                 for ( ; rela < relalim; rela++) {
1339                         symidx = ELF_R_SYM(rela->r_info);
1340                         if (symidx >= ef->ddbsymcnt)
1341                                 continue;
1342                         sym = ef->ddbsymtab + symidx;
1343                         /* Only do local relocs */
1344                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1345                                 continue;
1346                         elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1347                             elf_obj_lookup);
1348                 }
1349         }
1350 }
1351
1352 static long
1353 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1354 {
1355     elf_file_t ef = (elf_file_t)lf;
1356
1357     *symtab = ef->ddbsymtab;
1358
1359     if (*symtab == NULL)
1360         return (0);
1361
1362     return (ef->ddbsymcnt);
1363 }
1364
1365 static long
1366 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1367 {
1368     elf_file_t ef = (elf_file_t)lf;
1369
1370     *strtab = ef->ddbstrtab;
1371
1372     if (*strtab == NULL)
1373         return (0);
1374
1375     return (ef->ddbstrcnt);
1376 }