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 int      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 int      elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps,
 148                     Elf_Addr *);
 149
 150 static kobj_method_t link_elf_methods[] = {
 151         KOBJMETHOD(linker_lookup_symbol,        link_elf_lookup_symbol),
 152         KOBJMETHOD(linker_symbol_values,        link_elf_symbol_values),
 153         KOBJMETHOD(linker_search_symbol,        link_elf_search_symbol),
 154         KOBJMETHOD(linker_unload,               link_elf_unload_file),
 155         KOBJMETHOD(linker_load_file,            link_elf_load_file),
 156         KOBJMETHOD(linker_link_preload,         link_elf_link_preload),
 157         KOBJMETHOD(linker_link_preload_finish,  link_elf_link_preload_finish),
 158         KOBJMETHOD(linker_lookup_set,           link_elf_lookup_set),
 159         KOBJMETHOD(linker_each_function_name,   link_elf_each_function_name),
 160         KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
 161         KOBJMETHOD(linker_ctf_get,              link_elf_ctf_get),
 162         KOBJMETHOD(linker_symtab_get,           link_elf_symtab_get),
 163         KOBJMETHOD(linker_strtab_get,           link_elf_strtab_get),
 164         { 0, 0 }
 165 };
 166
 167 static struct linker_class link_elf_class = {
 168 #if ELF_TARG_CLASS == ELFCLASS32
 169         "elf32_obj",
 170 #else
 171         "elf64_obj",
 172 #endif
 173         link_elf_methods, sizeof(struct elf_file)
 174 };
 175
 176 static int      relocate_file(elf_file_t ef);
 177 static void     elf_obj_cleanup_globals_cache(elf_file_t);
 178
 179 static void
 180 link_elf_error(const char *filename, const char *s)
 181 {
 182         if (filename == NULL)
 183                 printf("kldload: %s\n", s);
 184         else
 185                 printf("kldload: %s: %s\n", filename, s);
 186 }
 187
 188 static void
 189 link_elf_init(void *arg)
 190 {
 191
 192         linker_add_class(&link_elf_class);
 193 }
 194
 195 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
 196
 197 static int
 198 link_elf_link_preload(linker_class_t cls, const char *filename,
 199     linker_file_t *result)
 200 {
 201         Elf_Ehdr *hdr;
 202         Elf_Shdr *shdr;
 203         Elf_Sym *es;
 204         void *modptr, *baseptr, *sizeptr;
 205         char *type;
 206         elf_file_t ef;
 207         linker_file_t lf;
 208         Elf_Addr off;
 209         int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
 210
 211         /* Look to see if we have the file preloaded */
 212         modptr = preload_search_by_name(filename);
 213         if (modptr == NULL)
 214                 return ENOENT;
 215
 216         type = (char *)preload_search_info(modptr, MODINFO_TYPE);
 217         baseptr = preload_search_info(modptr, MODINFO_ADDR);
 218         sizeptr = preload_search_info(modptr, MODINFO_SIZE);
 219         hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
 220             MODINFOMD_ELFHDR);
 221         shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
 222             MODINFOMD_SHDR);
 223         if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
 224             " obj module") != 0 &&
 225             strcmp(type, "elf obj module") != 0)) {
 226                 return (EFTYPE);
 227         }
 228         if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
 229             shdr == NULL)
 230                 return (EINVAL);
 231
 232         lf = linker_make_file(filename, &link_elf_class);
 233         if (lf == NULL)
 234                 return (ENOMEM);
 235
 236         ef = (elf_file_t)lf;
 237         ef->preloaded = 1;
 238         ef->address = *(caddr_t *)baseptr;
 239         lf->address = *(caddr_t *)baseptr;
 240         lf->size = *(size_t *)sizeptr;
 241
 242         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
 243             hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
 244             hdr->e_ident[EI_VERSION] != EV_CURRENT ||
 245             hdr->e_version != EV_CURRENT ||
 246             hdr->e_type != ET_REL ||
 247             hdr->e_machine != ELF_TARG_MACH) {
 248                 error = EFTYPE;
 249                 goto out;
 250         }
 251         ef->e_shdr = shdr;
 252
 253         /* Scan the section header for information and table sizing. */
 254         symtabindex = -1;
 255         symstrindex = -1;
 256         for (i = 0; i < hdr->e_shnum; i++) {
 257                 switch (shdr[i].sh_type) {
 258                 case SHT_PROGBITS:
 259                 case SHT_NOBITS:
 260 #ifdef __amd64__
 261                 case SHT_AMD64_UNWIND:
 262 #endif
 263                         ef->nprogtab++;
 264                         break;
 265                 case SHT_SYMTAB:
 266                         symtabindex = i;
 267                         symstrindex = shdr[i].sh_link;
 268                         break;
 269                 case SHT_REL:
 270                         ef->nreltab++;
 271                         break;
 272                 case SHT_RELA:
 273                         ef->nrelatab++;
 274                         break;
 275                 }
 276         }
 277
 278         shstrindex = hdr->e_shstrndx;
 279         if (ef->nprogtab == 0 || symstrindex < 0 ||
 280             symstrindex >= hdr->e_shnum ||
 281             shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
 282             shstrindex >= hdr->e_shnum ||
 283             shdr[shstrindex].sh_type != SHT_STRTAB) {
 284                 printf("%s: bad/missing section headers\n", filename);
 285                 error = ENOEXEC;
 286                 goto out;
 287         }
 288
 289         /* Allocate space for tracking the load chunks */
 290         if (ef->nprogtab != 0)
 291                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 292                     M_LINKER, M_WAITOK | M_ZERO);
 293         if (ef->nreltab != 0)
 294                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 295                     M_LINKER, M_WAITOK | M_ZERO);
 296         if (ef->nrelatab != 0)
 297                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 298                     M_LINKER, M_WAITOK | M_ZERO);
 299         if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
 300             (ef->nreltab != 0 && ef->reltab == NULL) ||
 301             (ef->nrelatab != 0 && ef->relatab == NULL)) {
 302                 error = ENOMEM;
 303                 goto out;
 304         }
 305
 306         /* XXX, relocate the sh_addr fields saved by the loader. */
 307         off = 0;
 308         for (i = 0; i < hdr->e_shnum; i++) {
 309                 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
 310                         off = shdr[i].sh_addr;
 311         }
 312         for (i = 0; i < hdr->e_shnum; i++) {
 313                 if (shdr[i].sh_addr != 0)
 314                         shdr[i].sh_addr = shdr[i].sh_addr - off +
 315                             (Elf_Addr)ef->address;
 316         }
 317
 318         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 319         ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
 320         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 321         ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
 322         ef->shstrcnt = shdr[shstrindex].sh_size;
 323         ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
 324
 325         /* Now fill out progtab and the relocation tables. */
 326         pb = 0;
 327         rl = 0;
 328         ra = 0;
 329         for (i = 0; i < hdr->e_shnum; i++) {
 330                 switch (shdr[i].sh_type) {
 331                 case SHT_PROGBITS:
 332                 case SHT_NOBITS:
 333 #ifdef __amd64__
 334                 case SHT_AMD64_UNWIND:
 335 #endif
 336                         ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
 337                         if (shdr[i].sh_type == SHT_PROGBITS)
 338                                 ef->progtab[pb].name = "<<PROGBITS>>";
 339 #ifdef __amd64__
 340                         else if (shdr[i].sh_type == SHT_AMD64_UNWIND)
 341                                 ef->progtab[pb].name = "<<UNWIND>>";
 342 #endif
 343                         else
 344                                 ef->progtab[pb].name = "<<NOBITS>>";
 345                         ef->progtab[pb].size = shdr[i].sh_size;
 346                         ef->progtab[pb].sec = i;
 347                         if (ef->shstrtab && shdr[i].sh_name != 0)
 348                                 ef->progtab[pb].name =
 349                                     ef->shstrtab + shdr[i].sh_name;
 350                         if (ef->progtab[pb].name != NULL &&
 351                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
 352                                 void *dpcpu;
 353
 354                                 dpcpu = dpcpu_alloc(shdr[i].sh_size);
 355                                 if (dpcpu == NULL) {
 356                                         error = ENOSPC;
 357                                         goto out;
 358                                 }
 359                                 memcpy(dpcpu, ef->progtab[pb].addr,
 360                                     ef->progtab[pb].size);
 361                                 dpcpu_copy(dpcpu, shdr[i].sh_size);
 362                                 ef->progtab[pb].addr = dpcpu;
 363 #ifdef VIMAGE
 364                         } else if (ef->progtab[pb].name != NULL &&
 365                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
 366                                 void *vnet_data;
 367
 368                                 vnet_data = vnet_data_alloc(shdr[i].sh_size);
 369                                 if (vnet_data == NULL) {
 370                                         error = ENOSPC;
 371                                         goto out;
 372                                 }
 373                                 memcpy(vnet_data, ef->progtab[pb].addr,
 374                                     ef->progtab[pb].size);
 375                                 vnet_data_copy(vnet_data, shdr[i].sh_size);
 376                                 ef->progtab[pb].addr = vnet_data;
 377 #endif
 378                         }
 379
 380                         /* Update all symbol values with the offset. */
 381                         for (j = 0; j < ef->ddbsymcnt; j++) {
 382                                 es = &ef->ddbsymtab[j];
 383                                 if (es->st_shndx != i)
 384                                         continue;
 385                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 386                         }
 387                         pb++;
 388                         break;
 389                 case SHT_REL:
 390                         ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
 391                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 392                         ef->reltab[rl].sec = shdr[i].sh_info;
 393                         rl++;
 394                         break;
 395                 case SHT_RELA:
 396                         ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
 397                         ef->relatab[ra].nrela =
 398                             shdr[i].sh_size / sizeof(Elf_Rela);
 399                         ef->relatab[ra].sec = shdr[i].sh_info;
 400                         ra++;
 401                         break;
 402                 }
 403         }
 404         if (pb != ef->nprogtab) {
 405                 printf("%s: lost progbits\n", filename);
 406                 error = ENOEXEC;
 407                 goto out;
 408         }
 409         if (rl != ef->nreltab) {
 410                 printf("%s: lost reltab\n", filename);
 411                 error = ENOEXEC;
 412                 goto out;
 413         }
 414         if (ra != ef->nrelatab) {
 415                 printf("%s: lost relatab\n", filename);
 416                 error = ENOEXEC;
 417                 goto out;
 418         }
 419
 420         /* Local intra-module relocations */
 421         error = link_elf_reloc_local(lf);
 422         if (error != 0)
 423                 goto out;
 424
 425         *result = lf;
 426         return (0);
 427
 428 out:
 429         /* preload not done this way */
 430         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 431         return (error);
 432 }
 433
 434 static int
 435 link_elf_link_preload_finish(linker_file_t lf)
 436 {
 437         elf_file_t ef;
 438         int error;
 439
 440         ef = (elf_file_t)lf;
 441         error = relocate_file(ef);
 442         if (error)
 443                 return error;
 444
 445         /* Notify MD code that a module is being loaded. */
 446         error = elf_cpu_load_file(lf);
 447         if (error)
 448                 return (error);
 449
 450         return (0);
 451 }
 452
 453 static int
 454 link_elf_load_file(linker_class_t cls, const char *filename,
 455     linker_file_t *result)
 456 {
 457         struct nameidata nd;
 458         struct thread *td = curthread;  /* XXX */
 459         Elf_Ehdr *hdr;
 460         Elf_Shdr *shdr;
 461         Elf_Sym *es;
 462         int nbytes, i, j;
 463         vm_offset_t mapbase;
 464         size_t mapsize;
 465         int error = 0;
 466         ssize_t resid;
 467         int flags;
 468         elf_file_t ef;
 469         linker_file_t lf;
 470         int symtabindex;
 471         int symstrindex;
 472         int shstrindex;
 473         int nsym;
 474         int pb, rl, ra;
 475         int alignmask;
 476
 477         shdr = NULL;
 478         lf = NULL;
 479         mapsize = 0;
 480         hdr = NULL;
 481
 482         NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
 483         flags = FREAD;
 484         error = vn_open(&nd, &flags, 0, NULL);
 485         if (error)
 486                 return error;
 487         NDFREE(&nd, NDF_ONLY_PNBUF);
 488         if (nd.ni_vp->v_type != VREG) {
 489                 error = ENOEXEC;
 490                 goto out;
 491         }
 492 #ifdef MAC
 493         error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
 494         if (error) {
 495                 goto out;
 496         }
 497 #endif
 498
 499         /* Read the elf header from the file. */
 500         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
 501         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
 502             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 503             &resid, td);
 504         if (error)
 505                 goto out;
 506         if (resid != 0){
 507                 error = ENOEXEC;
 508                 goto out;
 509         }
 510
 511         if (!IS_ELF(*hdr)) {
 512                 error = ENOEXEC;
 513                 goto out;
 514         }
 515
 516         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
 517             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
 518                 link_elf_error(filename, "Unsupported file layout");
 519                 error = ENOEXEC;
 520                 goto out;
 521         }
 522         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
 523             || hdr->e_version != EV_CURRENT) {
 524                 link_elf_error(filename, "Unsupported file version");
 525                 error = ENOEXEC;
 526                 goto out;
 527         }
 528         if (hdr->e_type != ET_REL) {
 529                 error = ENOSYS;
 530                 goto out;
 531         }
 532         if (hdr->e_machine != ELF_TARG_MACH) {
 533                 link_elf_error(filename, "Unsupported machine");
 534                 error = ENOEXEC;
 535                 goto out;
 536         }
 537
 538         lf = linker_make_file(filename, &link_elf_class);
 539         if (!lf) {
 540                 error = ENOMEM;
 541                 goto out;
 542         }
 543         ef = (elf_file_t) lf;
 544         ef->nprogtab = 0;
 545         ef->e_shdr = 0;
 546         ef->nreltab = 0;
 547         ef->nrelatab = 0;
 548
 549         /* Allocate and read in the section header */
 550         nbytes = hdr->e_shnum * hdr->e_shentsize;
 551         if (nbytes == 0 || hdr->e_shoff == 0 ||
 552             hdr->e_shentsize != sizeof(Elf_Shdr)) {
 553                 error = ENOEXEC;
 554                 goto out;
 555         }
 556         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
 557         ef->e_shdr = shdr;
 558         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
 559             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
 560         if (error)
 561                 goto out;
 562         if (resid) {
 563                 error = ENOEXEC;
 564                 goto out;
 565         }
 566
 567         /* Scan the section header for information and table sizing. */
 568         nsym = 0;
 569         symtabindex = -1;
 570         symstrindex = -1;
 571         for (i = 0; i < hdr->e_shnum; i++) {
 572                 if (shdr[i].sh_size == 0)
 573                         continue;
 574                 switch (shdr[i].sh_type) {
 575                 case SHT_PROGBITS:
 576                 case SHT_NOBITS:
 577 #ifdef __amd64__
 578                 case SHT_AMD64_UNWIND:
 579 #endif
 580                         ef->nprogtab++;
 581                         break;
 582                 case SHT_SYMTAB:
 583                         nsym++;
 584                         symtabindex = i;
 585                         symstrindex = shdr[i].sh_link;
 586                         break;
 587                 case SHT_REL:
 588                         ef->nreltab++;
 589                         break;
 590                 case SHT_RELA:
 591                         ef->nrelatab++;
 592                         break;
 593                 case SHT_STRTAB:
 594                         break;
 595                 }
 596         }
 597         if (ef->nprogtab == 0) {
 598                 link_elf_error(filename, "file has no contents");
 599                 error = ENOEXEC;
 600                 goto out;
 601         }
 602         if (nsym != 1) {
 603                 /* Only allow one symbol table for now */
 604                 link_elf_error(filename, "file has no valid symbol table");
 605                 error = ENOEXEC;
 606                 goto out;
 607         }
 608         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
 609             shdr[symstrindex].sh_type != SHT_STRTAB) {
 610                 link_elf_error(filename, "file has invalid symbol strings");
 611                 error = ENOEXEC;
 612                 goto out;
 613         }
 614
 615         /* Allocate space for tracking the load chunks */
 616         if (ef->nprogtab != 0)
 617                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 618                     M_LINKER, M_WAITOK | M_ZERO);
 619         if (ef->nreltab != 0)
 620                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 621                     M_LINKER, M_WAITOK | M_ZERO);
 622         if (ef->nrelatab != 0)
 623                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 624                     M_LINKER, M_WAITOK | M_ZERO);
 625
 626         if (symtabindex == -1) {
 627                 link_elf_error(filename, "lost symbol table index");
 628                 error = ENOEXEC;
 629                 goto out;
 630         }
 631         /* Allocate space for and load the symbol table */
 632         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 633         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
 634         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
 635             shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
 636             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 637             &resid, td);
 638         if (error)
 639                 goto out;
 640         if (resid != 0){
 641                 error = EINVAL;
 642                 goto out;
 643         }
 644
 645         if (symstrindex == -1) {
 646                 link_elf_error(filename, "lost symbol string index");
 647                 error = ENOEXEC;
 648                 goto out;
 649         }
 650         /* Allocate space for and load the symbol strings */
 651         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 652         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
 653         error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
 654             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
 655             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 656             &resid, td);
 657         if (error)
 658                 goto out;
 659         if (resid != 0){
 660                 error = EINVAL;
 661                 goto out;
 662         }
 663
 664         /* Do we have a string table for the section names?  */
 665         shstrindex = -1;
 666         if (hdr->e_shstrndx != 0 &&
 667             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
 668                 shstrindex = hdr->e_shstrndx;
 669                 ef->shstrcnt = shdr[shstrindex].sh_size;
 670                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
 671                     M_WAITOK);
 672                 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
 673                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
 674                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 675                     &resid, td);
 676                 if (error)
 677                         goto out;
 678                 if (resid != 0){
 679                         error = EINVAL;
 680                         goto out;
 681                 }
 682         }
 683
 684         /* Size up code/data(progbits) and bss(nobits). */
 685         alignmask = 0;
 686         for (i = 0; i < hdr->e_shnum; i++) {
 687                 if (shdr[i].sh_size == 0)
 688                         continue;
 689                 switch (shdr[i].sh_type) {
 690                 case SHT_PROGBITS:
 691                 case SHT_NOBITS:
 692 #ifdef __amd64__
 693                 case SHT_AMD64_UNWIND:
 694 #endif
 695                         alignmask = shdr[i].sh_addralign - 1;
 696                         mapsize += alignmask;
 697                         mapsize &= ~alignmask;
 698                         mapsize += shdr[i].sh_size;
 699                         break;
 700                 }
 701         }
 702
 703         /*
 704          * We know how much space we need for the text/data/bss/etc.
 705          * This stuff needs to be in a single chunk so that profiling etc
 706          * can get the bounds and gdb can associate offsets with modules
 707          */
 708         ef->object = vm_object_allocate(OBJT_DEFAULT,
 709             round_page(mapsize) >> PAGE_SHIFT);
 710         if (ef->object == NULL) {
 711                 error = ENOMEM;
 712                 goto out;
 713         }
 714         ef->address = (caddr_t) vm_map_min(kernel_map);
 715
 716         /*
 717          * In order to satisfy amd64's architectural requirements on the
 718          * location of code and data in the kernel's address space, request a
 719          * mapping that is above the kernel.
 720          */
 721 #ifdef __amd64__
 722         mapbase = KERNBASE;
 723 #else
 724         mapbase = VM_MIN_KERNEL_ADDRESS;
 725 #endif
 726         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
 727             round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
 728             VM_PROT_ALL, 0);
 729         if (error) {
 730                 vm_object_deallocate(ef->object);
 731                 ef->object = 0;
 732                 goto out;
 733         }
 734
 735         /* Wire the pages */
 736         error = vm_map_wire(kernel_map, mapbase,
 737             mapbase + round_page(mapsize),
 738             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 739         if (error != KERN_SUCCESS) {
 740                 error = ENOMEM;
 741                 goto out;
 742         }
 743
 744         /* Inform the kld system about the situation */
 745         lf->address = ef->address = (caddr_t)mapbase;
 746         lf->size = mapsize;
 747
 748         /*
 749          * Now load code/data(progbits), zero bss(nobits), allocate space for
 750          * and load relocs
 751          */
 752         pb = 0;
 753         rl = 0;
 754         ra = 0;
 755         alignmask = 0;
 756         for (i = 0; i < hdr->e_shnum; i++) {
 757                 if (shdr[i].sh_size == 0)
 758                         continue;
 759                 switch (shdr[i].sh_type) {
 760                 case SHT_PROGBITS:
 761                 case SHT_NOBITS:
 762 #ifdef __amd64__
 763                 case SHT_AMD64_UNWIND:
 764 #endif
 765                         alignmask = shdr[i].sh_addralign - 1;
 766                         mapbase += alignmask;
 767                         mapbase &= ~alignmask;
 768                         if (ef->shstrtab && shdr[i].sh_name != 0)
 769                                 ef->progtab[pb].name =
 770                                     ef->shstrtab + shdr[i].sh_name;
 771                         else if (shdr[i].sh_type == SHT_PROGBITS)
 772                                 ef->progtab[pb].name = "<<PROGBITS>>";
 773 #ifdef __amd64__
 774                         else if (shdr[i].sh_type == SHT_AMD64_UNWIND)
 775                                 ef->progtab[pb].name = "<<UNWIND>>";
 776 #endif
 777                         else
 778                                 ef->progtab[pb].name = "<<NOBITS>>";
 779                         if (ef->progtab[pb].name != NULL &&
 780                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 781                                 ef->progtab[pb].addr =
 782                                     dpcpu_alloc(shdr[i].sh_size);
 783 #ifdef VIMAGE
 784                         else if (ef->progtab[pb].name != NULL &&
 785                             !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 786                                 ef->progtab[pb].addr =
 787                                     vnet_data_alloc(shdr[i].sh_size);
 788 #endif
 789                         else
 790                                 ef->progtab[pb].addr =
 791                                     (void *)(uintptr_t)mapbase;
 792                         if (ef->progtab[pb].addr == NULL) {
 793                                 error = ENOSPC;
 794                                 goto out;
 795                         }
 796                         ef->progtab[pb].size = shdr[i].sh_size;
 797                         ef->progtab[pb].sec = i;
 798                         if (shdr[i].sh_type == SHT_PROGBITS
 799 #ifdef __amd64__
 800                             || shdr[i].sh_type == SHT_AMD64_UNWIND
 801 #endif
 802                             ) {
 803                                 error = vn_rdwr(UIO_READ, nd.ni_vp,
 804                                     ef->progtab[pb].addr,
 805                                     shdr[i].sh_size, shdr[i].sh_offset,
 806                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
 807                                     NOCRED, &resid, td);
 808                                 if (error)
 809                                         goto out;
 810                                 if (resid != 0){
 811                                         error = EINVAL;
 812                                         goto out;
 813                                 }
 814                                 /* Initialize the per-cpu or vnet area. */
 815                                 if (ef->progtab[pb].addr != (void *)mapbase &&
 816                                     !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 817                                         dpcpu_copy(ef->progtab[pb].addr,
 818                                             shdr[i].sh_size);
 819 #ifdef VIMAGE
 820                                 else if (ef->progtab[pb].addr !=
 821                                     (void *)mapbase &&
 822                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 823                                         vnet_data_copy(ef->progtab[pb].addr,
 824                                             shdr[i].sh_size);
 825 #endif
 826                         } else
 827                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
 828
 829                         /* Update all symbol values with the offset. */
 830                         for (j = 0; j < ef->ddbsymcnt; j++) {
 831                                 es = &ef->ddbsymtab[j];
 832                                 if (es->st_shndx != i)
 833                                         continue;
 834                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 835                         }
 836                         mapbase += shdr[i].sh_size;
 837                         pb++;
 838                         break;
 839                 case SHT_REL:
 840                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
 841                             M_WAITOK);
 842                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 843                         ef->reltab[rl].sec = shdr[i].sh_info;
 844                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 845                             (void *)ef->reltab[rl].rel,
 846                             shdr[i].sh_size, shdr[i].sh_offset,
 847                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 848                             &resid, td);
 849                         if (error)
 850                                 goto out;
 851                         if (resid != 0){
 852                                 error = EINVAL;
 853                                 goto out;
 854                         }
 855                         rl++;
 856                         break;
 857                 case SHT_RELA:
 858                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
 859                             M_WAITOK);
 860                         ef->relatab[ra].nrela =
 861                             shdr[i].sh_size / sizeof(Elf_Rela);
 862                         ef->relatab[ra].sec = shdr[i].sh_info;
 863                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 864                             (void *)ef->relatab[ra].rela,
 865                             shdr[i].sh_size, shdr[i].sh_offset,
 866                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 867                             &resid, td);
 868                         if (error)
 869                                 goto out;
 870                         if (resid != 0){
 871                                 error = EINVAL;
 872                                 goto out;
 873                         }
 874                         ra++;
 875                         break;
 876                 }
 877         }
 878         if (pb != ef->nprogtab) {
 879                 link_elf_error(filename, "lost progbits");
 880                 error = ENOEXEC;
 881                 goto out;
 882         }
 883         if (rl != ef->nreltab) {
 884                 link_elf_error(filename, "lost reltab");
 885                 error = ENOEXEC;
 886                 goto out;
 887         }
 888         if (ra != ef->nrelatab) {
 889                 link_elf_error(filename, "lost relatab");
 890                 error = ENOEXEC;
 891                 goto out;
 892         }
 893         if (mapbase != (vm_offset_t)ef->address + mapsize) {
 894                 printf(
 895                     "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
 896                     filename != NULL ? filename : "<none>",
 897                     (u_long)mapbase, ef->address, (u_long)mapsize,
 898                     (u_long)(vm_offset_t)ef->address + mapsize);
 899                 error = ENOMEM;
 900                 goto out;
 901         }
 902
 903         /* Local intra-module relocations */
 904         error = link_elf_reloc_local(lf);
 905         if (error != 0)
 906                 goto out;
 907
 908         /* Pull in dependencies */
 909         VOP_UNLOCK(nd.ni_vp, 0);
 910         error = linker_load_dependencies(lf);
 911         vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
 912         if (error)
 913                 goto out;
 914
 915         /* External relocations */
 916         error = relocate_file(ef);
 917         if (error)
 918                 goto out;
 919
 920         /* Notify MD code that a module is being loaded. */
 921         error = elf_cpu_load_file(lf);
 922         if (error)
 923                 goto out;
 924
 925         *result = lf;
 926
 927 out:
 928         VOP_UNLOCK(nd.ni_vp, 0);
 929         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
 930         if (error && lf)
 931                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 932         free(hdr, M_LINKER);
 933
 934         return error;
 935 }
 936
 937 static void
 938 link_elf_unload_file(linker_file_t file)
 939 {
 940         elf_file_t ef = (elf_file_t) file;
 941         int i;
 942
 943         /* Notify MD code that a module is being unloaded. */
 944         elf_cpu_unload_file(file);
 945
 946         if (ef->progtab) {
 947                 for (i = 0; i < ef->nprogtab; i++) {
 948                         if (ef->progtab[i].size == 0)
 949                                 continue;
 950                         if (ef->progtab[i].name == NULL)
 951                                 continue;
 952                         if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
 953                                 dpcpu_free(ef->progtab[i].addr,
 954                                     ef->progtab[i].size);
 955 #ifdef VIMAGE
 956                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
 957                                 vnet_data_free(ef->progtab[i].addr,
 958                                     ef->progtab[i].size);
 959 #endif
 960                 }
 961         }
 962         if (ef->preloaded) {
 963                 free(ef->reltab, M_LINKER);
 964                 free(ef->relatab, M_LINKER);
 965                 free(ef->progtab, M_LINKER);
 966                 free(ef->ctftab, M_LINKER);
 967                 free(ef->ctfoff, M_LINKER);
 968                 free(ef->typoff, M_LINKER);
 969                 if (file->filename != NULL)
 970                         preload_delete_name(file->filename);
 971                 /* XXX reclaim module memory? */
 972                 return;
 973         }
 974
 975         for (i = 0; i < ef->nreltab; i++)
 976                 free(ef->reltab[i].rel, M_LINKER);
 977         for (i = 0; i < ef->nrelatab; i++)
 978                 free(ef->relatab[i].rela, M_LINKER);
 979         free(ef->reltab, M_LINKER);
 980         free(ef->relatab, M_LINKER);
 981         free(ef->progtab, M_LINKER);
 982
 983         if (ef->object) {
 984                 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
 985                     (vm_offset_t) ef->address +
 986                     (ef->object->size << PAGE_SHIFT));
 987         }
 988         free(ef->e_shdr, M_LINKER);
 989         free(ef->ddbsymtab, M_LINKER);
 990         free(ef->ddbstrtab, M_LINKER);
 991         free(ef->shstrtab, M_LINKER);
 992         free(ef->ctftab, M_LINKER);
 993         free(ef->ctfoff, M_LINKER);
 994         free(ef->typoff, M_LINKER);
 995 }
 996
 997 static const char *
 998 symbol_name(elf_file_t ef, Elf_Size r_info)
 999 {
1000         const Elf_Sym *ref;
1001
1002         if (ELF_R_SYM(r_info)) {
1003                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1004                 return ef->ddbstrtab + ref->st_name;
1005         } else
1006                 return NULL;
1007 }
1008
1009 static Elf_Addr
1010 findbase(elf_file_t ef, int sec)
1011 {
1012         int i;
1013         Elf_Addr base = 0;
1014
1015         for (i = 0; i < ef->nprogtab; i++) {
1016                 if (sec == ef->progtab[i].sec) {
1017                         base = (Elf_Addr)ef->progtab[i].addr;
1018                         break;
1019                 }
1020         }
1021         return base;
1022 }
1023
1024 static int
1025 relocate_file(elf_file_t ef)
1026 {
1027         const Elf_Rel *rellim;
1028         const Elf_Rel *rel;
1029         const Elf_Rela *relalim;
1030         const Elf_Rela *rela;
1031         const char *symname;
1032         const Elf_Sym *sym;
1033         int i;
1034         Elf_Size symidx;
1035         Elf_Addr base;
1036
1037
1038         /* Perform relocations without addend if there are any: */
1039         for (i = 0; i < ef->nreltab; i++) {
1040                 rel = ef->reltab[i].rel;
1041                 if (rel == NULL) {
1042                         link_elf_error(ef->lf.filename, "lost a reltab!");
1043                         return (ENOEXEC);
1044                 }
1045                 rellim = rel + ef->reltab[i].nrel;
1046                 base = findbase(ef, ef->reltab[i].sec);
1047                 if (base == 0) {
1048                         link_elf_error(ef->lf.filename, "lost base for reltab");
1049                         return (ENOEXEC);
1050                 }
1051                 for ( ; rel < rellim; rel++) {
1052                         symidx = ELF_R_SYM(rel->r_info);
1053                         if (symidx >= ef->ddbsymcnt)
1054                                 continue;
1055                         sym = ef->ddbsymtab + symidx;
1056                         /* Local relocs are already done */
1057                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1058                                 continue;
1059                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1060                             elf_obj_lookup)) {
1061                                 symname = symbol_name(ef, rel->r_info);
1062                                 printf("link_elf_obj: symbol %s undefined\n",
1063                                     symname);
1064                                 return (ENOENT);
1065                         }
1066                 }
1067         }
1068
1069         /* Perform relocations with addend if there are any: */
1070         for (i = 0; i < ef->nrelatab; i++) {
1071                 rela = ef->relatab[i].rela;
1072                 if (rela == NULL) {
1073                         link_elf_error(ef->lf.filename, "lost a relatab!");
1074                         return (ENOEXEC);
1075                 }
1076                 relalim = rela + ef->relatab[i].nrela;
1077                 base = findbase(ef, ef->relatab[i].sec);
1078                 if (base == 0) {
1079                         link_elf_error(ef->lf.filename,
1080                             "lost base for relatab");
1081                         return (ENOEXEC);
1082                 }
1083                 for ( ; rela < relalim; rela++) {
1084                         symidx = ELF_R_SYM(rela->r_info);
1085                         if (symidx >= ef->ddbsymcnt)
1086                                 continue;
1087                         sym = ef->ddbsymtab + symidx;
1088                         /* Local relocs are already done */
1089                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1090                                 continue;
1091                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1092                             elf_obj_lookup)) {
1093                                 symname = symbol_name(ef, rela->r_info);
1094                                 printf("link_elf_obj: symbol %s undefined\n",
1095                                     symname);
1096                                 return (ENOENT);
1097                         }
1098                 }
1099         }
1100
1101         /*
1102          * Only clean SHN_FBSD_CACHED for successful return.  If we
1103          * modified symbol table for the object but found an
1104          * unresolved symbol, there is no reason to roll back.
1105          */
1106         elf_obj_cleanup_globals_cache(ef);
1107
1108         return (0);
1109 }
1110
1111 static int
1112 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1113 {
1114         elf_file_t ef = (elf_file_t) lf;
1115         const Elf_Sym *symp;
1116         const char *strp;
1117         int i;
1118
1119         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1120                 strp = ef->ddbstrtab + symp->st_name;
1121                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1122                         *sym = (c_linker_sym_t) symp;
1123                         return 0;
1124                 }
1125         }
1126         return ENOENT;
1127 }
1128
1129 static int
1130 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1131     linker_symval_t *symval)
1132 {
1133         elf_file_t ef = (elf_file_t) lf;
1134         const Elf_Sym *es = (const Elf_Sym*) sym;
1135
1136         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1137                 symval->name = ef->ddbstrtab + es->st_name;
1138                 symval->value = (caddr_t)es->st_value;
1139                 symval->size = es->st_size;
1140                 return 0;
1141         }
1142         return ENOENT;
1143 }
1144
1145 static int
1146 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1147     c_linker_sym_t *sym, long *diffp)
1148 {
1149         elf_file_t ef = (elf_file_t) lf;
1150         u_long off = (uintptr_t) (void *) value;
1151         u_long diff = off;
1152         u_long st_value;
1153         const Elf_Sym *es;
1154         const Elf_Sym *best = 0;
1155         int i;
1156
1157         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1158                 if (es->st_name == 0)
1159                         continue;
1160                 st_value = es->st_value;
1161                 if (off >= st_value) {
1162                         if (off - st_value < diff) {
1163                                 diff = off - st_value;
1164                                 best = es;
1165                                 if (diff == 0)
1166                                         break;
1167                         } else if (off - st_value == diff) {
1168                                 best = es;
1169                         }
1170                 }
1171         }
1172         if (best == 0)
1173                 *diffp = off;
1174         else
1175                 *diffp = diff;
1176         *sym = (c_linker_sym_t) best;
1177
1178         return 0;
1179 }
1180
1181 /*
1182  * Look up a linker set on an ELF system.
1183  */
1184 static int
1185 link_elf_lookup_set(linker_file_t lf, const char *name,
1186     void ***startp, void ***stopp, int *countp)
1187 {
1188         elf_file_t ef = (elf_file_t)lf;
1189         void **start, **stop;
1190         int i, count;
1191
1192         /* Relative to section number */
1193         for (i = 0; i < ef->nprogtab; i++) {
1194                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1195                     strcmp(ef->progtab[i].name + 4, name) == 0) {
1196                         start  = (void **)ef->progtab[i].addr;
1197                         stop = (void **)((char *)ef->progtab[i].addr +
1198                             ef->progtab[i].size);
1199                         count = stop - start;
1200                         if (startp)
1201                                 *startp = start;
1202                         if (stopp)
1203                                 *stopp = stop;
1204                         if (countp)
1205                                 *countp = count;
1206                         return (0);
1207                 }
1208         }
1209         return (ESRCH);
1210 }
1211
1212 static int
1213 link_elf_each_function_name(linker_file_t file,
1214     int (*callback)(const char *, void *), void *opaque)
1215 {
1216         elf_file_t ef = (elf_file_t)file;
1217         const Elf_Sym *symp;
1218         int i, error;
1219
1220         /* Exhaustive search */
1221         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1222                 if (symp->st_value != 0 &&
1223                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1224                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
1225                         if (error)
1226                                 return (error);
1227                 }
1228         }
1229         return (0);
1230 }
1231
1232 static int
1233 link_elf_each_function_nameval(linker_file_t file,
1234     linker_function_nameval_callback_t callback, void *opaque)
1235 {
1236         linker_symval_t symval;
1237         elf_file_t ef = (elf_file_t)file;
1238         const Elf_Sym* symp;
1239         int i, error;
1240
1241         /* Exhaustive search */
1242         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1243                 if (symp->st_value != 0 &&
1244                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1245                         error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1246                         if (error)
1247                                 return (error);
1248                         error = callback(file, i, &symval, opaque);
1249                         if (error)
1250                                 return (error);
1251                 }
1252         }
1253         return (0);
1254 }
1255
1256 static void
1257 elf_obj_cleanup_globals_cache(elf_file_t ef)
1258 {
1259         Elf_Sym *sym;
1260         Elf_Size i;
1261
1262         for (i = 0; i < ef->ddbsymcnt; i++) {
1263                 sym = ef->ddbsymtab + i;
1264                 if (sym->st_shndx == SHN_FBSD_CACHED) {
1265                         sym->st_shndx = SHN_UNDEF;
1266                         sym->st_value = 0;
1267                 }
1268         }
1269 }
1270
1271 /*
1272  * Symbol lookup function that can be used when the symbol index is known (ie
1273  * in relocations). It uses the symbol index instead of doing a fully fledged
1274  * hash table based lookup when such is valid. For example for local symbols.
1275  * This is not only more efficient, it's also more correct. It's not always
1276  * the case that the symbol can be found through the hash table.
1277  */
1278 static int
1279 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1280 {
1281         elf_file_t ef = (elf_file_t)lf;
1282         Elf_Sym *sym;
1283         const char *symbol;
1284         Elf_Addr res1;
1285
1286         /* Don't even try to lookup the symbol if the index is bogus. */
1287         if (symidx >= ef->ddbsymcnt) {
1288                 *res = 0;
1289                 return (EINVAL);
1290         }
1291
1292         sym = ef->ddbsymtab + symidx;
1293
1294         /* Quick answer if there is a definition included. */
1295         if (sym->st_shndx != SHN_UNDEF) {
1296                 *res = sym->st_value;
1297                 return (0);
1298         }
1299
1300         /* If we get here, then it is undefined and needs a lookup. */
1301         switch (ELF_ST_BIND(sym->st_info)) {
1302         case STB_LOCAL:
1303                 /* Local, but undefined? huh? */
1304                 *res = 0;
1305                 return (EINVAL);
1306
1307         case STB_GLOBAL:
1308         case STB_WEAK:
1309                 /* Relative to Data or Function name */
1310                 symbol = ef->ddbstrtab + sym->st_name;
1311
1312                 /* Force a lookup failure if the symbol name is bogus. */
1313                 if (*symbol == 0) {
1314                         *res = 0;
1315                         return (EINVAL);
1316                 }
1317                 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1318
1319                 /*
1320                  * Cache global lookups during module relocation. The failure
1321                  * case is particularly expensive for callers, who must scan
1322                  * through the entire globals table doing strcmp(). Cache to
1323                  * avoid doing such work repeatedly.
1324                  *
1325                  * After relocation is complete, undefined globals will be
1326                  * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1327                  * above.
1328                  */
1329                 if (res1 != 0) {
1330                         sym->st_shndx = SHN_FBSD_CACHED;
1331                         sym->st_value = res1;
1332                         *res = res1;
1333                         return (0);
1334                 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1335                         sym->st_value = 0;
1336                         *res = 0;
1337                         return (0);
1338                 }
1339                 return (EINVAL);
1340
1341         default:
1342                 return (EINVAL);
1343         }
1344 }
1345
1346 static void
1347 link_elf_fix_link_set(elf_file_t ef)
1348 {
1349         static const char startn[] = "__start_";
1350         static const char stopn[] = "__stop_";
1351         Elf_Sym *sym;
1352         const char *sym_name, *linkset_name;
1353         Elf_Addr startp, stopp;
1354         Elf_Size symidx;
1355         int start, i;
1356
1357         startp = stopp = 0;
1358         for (symidx = 1 /* zero entry is special */;
1359                 symidx < ef->ddbsymcnt; symidx++) {
1360                 sym = ef->ddbsymtab + symidx;
1361                 if (sym->st_shndx != SHN_UNDEF)
1362                         continue;
1363
1364                 sym_name = ef->ddbstrtab + sym->st_name;
1365                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1366                         start = 1;
1367                         linkset_name = sym_name + sizeof(startn) - 1;
1368                 }
1369                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1370                         start = 0;
1371                         linkset_name = sym_name + sizeof(stopn) - 1;
1372                 }
1373                 else
1374                         continue;
1375
1376                 for (i = 0; i < ef->nprogtab; i++) {
1377                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1378                                 startp = (Elf_Addr)ef->progtab[i].addr;
1379                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1380                                 break;
1381                         }
1382                 }
1383                 if (i == ef->nprogtab)
1384                         continue;
1385
1386                 sym->st_value = start ? startp : stopp;
1387                 sym->st_shndx = i;
1388         }
1389 }
1390
1391 static int
1392 link_elf_reloc_local(linker_file_t lf)
1393 {
1394         elf_file_t ef = (elf_file_t)lf;
1395         const Elf_Rel *rellim;
1396         const Elf_Rel *rel;
1397         const Elf_Rela *relalim;
1398         const Elf_Rela *rela;
1399         const Elf_Sym *sym;
1400         Elf_Addr base;
1401         int i;
1402         Elf_Size symidx;
1403
1404         link_elf_fix_link_set(ef);
1405
1406         /* Perform relocations without addend if there are any: */
1407         for (i = 0; i < ef->nreltab; i++) {
1408                 rel = ef->reltab[i].rel;
1409                 if (rel == NULL) {
1410                         link_elf_error(ef->lf.filename, "lost a reltab");
1411                         return (ENOEXEC);
1412                 }
1413                 rellim = rel + ef->reltab[i].nrel;
1414                 base = findbase(ef, ef->reltab[i].sec);
1415                 if (base == 0) {
1416                         link_elf_error(ef->lf.filename, "lost base for reltab");
1417                         return (ENOEXEC);
1418                 }
1419                 for ( ; rel < rellim; rel++) {
1420                         symidx = ELF_R_SYM(rel->r_info);
1421                         if (symidx >= ef->ddbsymcnt)
1422                                 continue;
1423                         sym = ef->ddbsymtab + symidx;
1424                         /* Only do local relocs */
1425                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1426                                 continue;
1427                         elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1428                             elf_obj_lookup);
1429                 }
1430         }
1431
1432         /* Perform relocations with addend if there are any: */
1433         for (i = 0; i < ef->nrelatab; i++) {
1434                 rela = ef->relatab[i].rela;
1435                 if (rela == NULL) {
1436                         link_elf_error(ef->lf.filename, "lost a relatab!");
1437                         return (ENOEXEC);
1438                 }
1439                 relalim = rela + ef->relatab[i].nrela;
1440                 base = findbase(ef, ef->relatab[i].sec);
1441                 if (base == 0) {
1442                         link_elf_error(ef->lf.filename, "lost base for reltab");
1443                         return (ENOEXEC);
1444                 }
1445                 for ( ; rela < relalim; rela++) {
1446                         symidx = ELF_R_SYM(rela->r_info);
1447                         if (symidx >= ef->ddbsymcnt)
1448                                 continue;
1449                         sym = ef->ddbsymtab + symidx;
1450                         /* Only do local relocs */
1451                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1452                                 continue;
1453                         elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1454                             elf_obj_lookup);
1455                 }
1456         }
1457         return (0);
1458 }
1459
1460 static long
1461 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1462 {
1463     elf_file_t ef = (elf_file_t)lf;
1464
1465     *symtab = ef->ddbsymtab;
1466
1467     if (*symtab == NULL)
1468         return (0);
1469
1470     return (ef->ddbsymcnt);
1471 }
1472
1473 static long
1474 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1475 {
1476     elf_file_t ef = (elf_file_t)lf;
1477
1478     *strtab = ef->ddbstrtab;
1479
1480     if (*strtab == NULL)
1481         return (0);
1482
1483     return (ef->ddbstrcnt);
1484 }