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), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE);
 693         if (error) {
 694                 vm_object_deallocate(ef->object);
 695                 ef->object = 0;
 696                 goto out;
 697         }
 698
 699         /* Wire the pages */
 700         error = vm_map_wire(kernel_map, mapbase,
 701             mapbase + round_page(mapsize),
 702             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 703         if (error != KERN_SUCCESS) {
 704                 error = ENOMEM;
 705                 goto out;
 706         }
 707
 708         /* Inform the kld system about the situation */
 709         lf->address = ef->address = (caddr_t)mapbase;
 710         lf->size = mapsize;
 711
 712         /*
 713          * Now load code/data(progbits), zero bss(nobits), allocate space for
 714          * and load relocs
 715          */
 716         pb = 0;
 717         rl = 0;
 718         ra = 0;
 719         alignmask = 0;
 720         for (i = 0; i < hdr->e_shnum; i++) {
 721                 if (shdr[i].sh_size == 0)
 722                         continue;
 723                 switch (shdr[i].sh_type) {
 724                 case SHT_PROGBITS:
 725                 case SHT_NOBITS:
 726                         alignmask = shdr[i].sh_addralign - 1;
 727                         mapbase += alignmask;
 728                         mapbase &= ~alignmask;
 729                         if (ef->shstrtab && shdr[i].sh_name != 0)
 730                                 ef->progtab[pb].name =
 731                                     ef->shstrtab + shdr[i].sh_name;
 732                         else if (shdr[i].sh_type == SHT_PROGBITS)
 733                                 ef->progtab[pb].name = "<<PROGBITS>>";
 734                         else
 735                                 ef->progtab[pb].name = "<<NOBITS>>";
 736                         if (ef->progtab[pb].name != NULL &&
 737                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 738                                 ef->progtab[pb].addr =
 739                                     dpcpu_alloc(shdr[i].sh_size);
 740 #ifdef VIMAGE
 741                         else if (ef->progtab[pb].name != NULL &&
 742                             !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 743                                 ef->progtab[pb].addr =
 744                                     vnet_data_alloc(shdr[i].sh_size);
 745 #endif
 746                         else
 747                                 ef->progtab[pb].addr =
 748                                     (void *)(uintptr_t)mapbase;
 749                         if (ef->progtab[pb].addr == NULL) {
 750                                 error = ENOSPC;
 751                                 goto out;
 752                         }
 753                         ef->progtab[pb].size = shdr[i].sh_size;
 754                         ef->progtab[pb].sec = i;
 755                         if (shdr[i].sh_type == SHT_PROGBITS) {
 756                                 error = vn_rdwr(UIO_READ, nd.ni_vp,
 757                                     ef->progtab[pb].addr,
 758                                     shdr[i].sh_size, shdr[i].sh_offset,
 759                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
 760                                     NOCRED, &resid, td);
 761                                 if (error)
 762                                         goto out;
 763                                 if (resid != 0){
 764                                         error = EINVAL;
 765                                         goto out;
 766                                 }
 767                                 /* Initialize the per-cpu or vnet area. */
 768                                 if (ef->progtab[pb].addr != (void *)mapbase &&
 769                                     !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 770                                         dpcpu_copy(ef->progtab[pb].addr,
 771                                             shdr[i].sh_size);
 772 #ifdef VIMAGE
 773                                 else if (ef->progtab[pb].addr !=
 774                                     (void *)mapbase &&
 775                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 776                                         vnet_data_copy(ef->progtab[pb].addr,
 777                                             shdr[i].sh_size);
 778 #endif
 779                         } else
 780                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
 781
 782                         /* Update all symbol values with the offset. */
 783                         for (j = 0; j < ef->ddbsymcnt; j++) {
 784                                 es = &ef->ddbsymtab[j];
 785                                 if (es->st_shndx != i)
 786                                         continue;
 787                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 788                         }
 789                         mapbase += shdr[i].sh_size;
 790                         pb++;
 791                         break;
 792                 case SHT_REL:
 793                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
 794                             M_WAITOK);
 795                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 796                         ef->reltab[rl].sec = shdr[i].sh_info;
 797                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 798                             (void *)ef->reltab[rl].rel,
 799                             shdr[i].sh_size, shdr[i].sh_offset,
 800                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 801                             &resid, td);
 802                         if (error)
 803                                 goto out;
 804                         if (resid != 0){
 805                                 error = EINVAL;
 806                                 goto out;
 807                         }
 808                         rl++;
 809                         break;
 810                 case SHT_RELA:
 811                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
 812                             M_WAITOK);
 813                         ef->relatab[ra].nrela =
 814                             shdr[i].sh_size / sizeof(Elf_Rela);
 815                         ef->relatab[ra].sec = shdr[i].sh_info;
 816                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 817                             (void *)ef->relatab[ra].rela,
 818                             shdr[i].sh_size, shdr[i].sh_offset,
 819                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 820                             &resid, td);
 821                         if (error)
 822                                 goto out;
 823                         if (resid != 0){
 824                                 error = EINVAL;
 825                                 goto out;
 826                         }
 827                         ra++;
 828                         break;
 829                 }
 830         }
 831         if (pb != ef->nprogtab)
 832                 panic("lost progbits");
 833         if (rl != ef->nreltab)
 834                 panic("lost reltab");
 835         if (ra != ef->nrelatab)
 836                 panic("lost relatab");
 837         if (mapbase != (vm_offset_t)ef->address + mapsize)
 838                 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
 839                     (u_long)mapbase, ef->address, (u_long)mapsize,
 840                     (u_long)(vm_offset_t)ef->address + mapsize);
 841
 842         /* Local intra-module relocations */
 843         link_elf_reloc_local(lf);
 844
 845         /* Pull in dependencies */
 846         VOP_UNLOCK(nd.ni_vp, 0);
 847         error = linker_load_dependencies(lf);
 848         vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
 849         if (error)
 850                 goto out;
 851
 852         /* External relocations */
 853         error = relocate_file(ef);
 854         if (error)
 855                 goto out;
 856
 857         /* Notify MD code that a module is being loaded. */
 858         error = elf_cpu_load_file(lf);
 859         if (error)
 860                 goto out;
 861
 862         *result = lf;
 863
 864 out:
 865         VOP_UNLOCK(nd.ni_vp, 0);
 866         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
 867         if (error && lf)
 868                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 869         if (hdr)
 870                 free(hdr, M_LINKER);
 871
 872         return error;
 873 }
 874
 875 static void
 876 link_elf_unload_file(linker_file_t file)
 877 {
 878         elf_file_t ef = (elf_file_t) file;
 879         int i;
 880
 881         /* Notify MD code that a module is being unloaded. */
 882         elf_cpu_unload_file(file);
 883
 884         if (ef->progtab) {
 885                 for (i = 0; i < ef->nprogtab; i++) {
 886                         if (ef->progtab[i].size == 0)
 887                                 continue;
 888                         if (ef->progtab[i].name == NULL)
 889                                 continue;
 890                         if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
 891                                 dpcpu_free(ef->progtab[i].addr,
 892                                     ef->progtab[i].size);
 893 #ifdef VIMAGE
 894                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
 895                                 vnet_data_free(ef->progtab[i].addr,
 896                                     ef->progtab[i].size);
 897 #endif
 898                 }
 899         }
 900         if (ef->preloaded) {
 901                 if (ef->reltab)
 902                         free(ef->reltab, M_LINKER);
 903                 if (ef->relatab)
 904                         free(ef->relatab, M_LINKER);
 905                 if (ef->progtab)
 906                         free(ef->progtab, M_LINKER);
 907                 if (ef->ctftab)
 908                         free(ef->ctftab, M_LINKER);
 909                 if (ef->ctfoff)
 910                         free(ef->ctfoff, M_LINKER);
 911                 if (ef->typoff)
 912                         free(ef->typoff, M_LINKER);
 913                 if (file->filename != NULL)
 914                         preload_delete_name(file->filename);
 915                 /* XXX reclaim module memory? */
 916                 return;
 917         }
 918
 919         for (i = 0; i < ef->nreltab; i++)
 920                 if (ef->reltab[i].rel)
 921                         free(ef->reltab[i].rel, M_LINKER);
 922         for (i = 0; i < ef->nrelatab; i++)
 923                 if (ef->relatab[i].rela)
 924                         free(ef->relatab[i].rela, M_LINKER);
 925         if (ef->reltab)
 926                 free(ef->reltab, M_LINKER);
 927         if (ef->relatab)
 928                 free(ef->relatab, M_LINKER);
 929         if (ef->progtab)
 930                 free(ef->progtab, M_LINKER);
 931
 932         if (ef->object) {
 933                 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
 934                     (vm_offset_t) ef->address +
 935                     (ef->object->size << PAGE_SHIFT));
 936         }
 937         if (ef->e_shdr)
 938                 free(ef->e_shdr, M_LINKER);
 939         if (ef->ddbsymtab)
 940                 free(ef->ddbsymtab, M_LINKER);
 941         if (ef->ddbstrtab)
 942                 free(ef->ddbstrtab, M_LINKER);
 943         if (ef->shstrtab)
 944                 free(ef->shstrtab, M_LINKER);
 945         if (ef->ctftab)
 946                 free(ef->ctftab, M_LINKER);
 947         if (ef->ctfoff)
 948                 free(ef->ctfoff, M_LINKER);
 949         if (ef->typoff)
 950                 free(ef->typoff, M_LINKER);
 951 }
 952
 953 static const char *
 954 symbol_name(elf_file_t ef, Elf_Size r_info)
 955 {
 956         const Elf_Sym *ref;
 957
 958         if (ELF_R_SYM(r_info)) {
 959                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
 960                 return ef->ddbstrtab + ref->st_name;
 961         } else
 962                 return NULL;
 963 }
 964
 965 static Elf_Addr
 966 findbase(elf_file_t ef, int sec)
 967 {
 968         int i;
 969         Elf_Addr base = 0;
 970
 971         for (i = 0; i < ef->nprogtab; i++) {
 972                 if (sec == ef->progtab[i].sec) {
 973                         base = (Elf_Addr)ef->progtab[i].addr;
 974                         break;
 975                 }
 976         }
 977         return base;
 978 }
 979
 980 static int
 981 relocate_file(elf_file_t ef)
 982 {
 983         const Elf_Rel *rellim;
 984         const Elf_Rel *rel;
 985         const Elf_Rela *relalim;
 986         const Elf_Rela *rela;
 987         const char *symname;
 988         const Elf_Sym *sym;
 989         int i;
 990         Elf_Size symidx;
 991         Elf_Addr base;
 992
 993
 994         /* Perform relocations without addend if there are any: */
 995         for (i = 0; i < ef->nreltab; i++) {
 996                 rel = ef->reltab[i].rel;
 997                 if (rel == NULL)
 998                         panic("lost a reltab!");
 999                 rellim = rel + ef->reltab[i].nrel;
1000                 base = findbase(ef, ef->reltab[i].sec);
1001                 if (base == 0)
1002                         panic("lost base for reltab");
1003                 for ( ; rel < rellim; rel++) {
1004                         symidx = ELF_R_SYM(rel->r_info);
1005                         if (symidx >= ef->ddbsymcnt)
1006                                 continue;
1007                         sym = ef->ddbsymtab + symidx;
1008                         /* Local relocs are already done */
1009                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1010                                 continue;
1011                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1012                             elf_obj_lookup)) {
1013                                 symname = symbol_name(ef, rel->r_info);
1014                                 printf("link_elf_obj: symbol %s undefined\n",
1015                                     symname);
1016                                 return ENOENT;
1017                         }
1018                 }
1019         }
1020
1021         /* Perform relocations with addend if there are any: */
1022         for (i = 0; i < ef->nrelatab; i++) {
1023                 rela = ef->relatab[i].rela;
1024                 if (rela == NULL)
1025                         panic("lost a relatab!");
1026                 relalim = rela + ef->relatab[i].nrela;
1027                 base = findbase(ef, ef->relatab[i].sec);
1028                 if (base == 0)
1029                         panic("lost base for relatab");
1030                 for ( ; rela < relalim; rela++) {
1031                         symidx = ELF_R_SYM(rela->r_info);
1032                         if (symidx >= ef->ddbsymcnt)
1033                                 continue;
1034                         sym = ef->ddbsymtab + symidx;
1035                         /* Local relocs are already done */
1036                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1037                                 continue;
1038                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1039                             elf_obj_lookup)) {
1040                                 symname = symbol_name(ef, rela->r_info);
1041                                 printf("link_elf_obj: symbol %s undefined\n",
1042                                     symname);
1043                                 return ENOENT;
1044                         }
1045                 }
1046         }
1047
1048         return 0;
1049 }
1050
1051 static int
1052 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1053 {
1054         elf_file_t ef = (elf_file_t) lf;
1055         const Elf_Sym *symp;
1056         const char *strp;
1057         int i;
1058
1059         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1060                 strp = ef->ddbstrtab + symp->st_name;
1061                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1062                         *sym = (c_linker_sym_t) symp;
1063                         return 0;
1064                 }
1065         }
1066         return ENOENT;
1067 }
1068
1069 static int
1070 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1071     linker_symval_t *symval)
1072 {
1073         elf_file_t ef = (elf_file_t) lf;
1074         const Elf_Sym *es = (const Elf_Sym*) sym;
1075
1076         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1077                 symval->name = ef->ddbstrtab + es->st_name;
1078                 symval->value = (caddr_t)es->st_value;
1079                 symval->size = es->st_size;
1080                 return 0;
1081         }
1082         return ENOENT;
1083 }
1084
1085 static int
1086 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1087     c_linker_sym_t *sym, long *diffp)
1088 {
1089         elf_file_t ef = (elf_file_t) lf;
1090         u_long off = (uintptr_t) (void *) value;
1091         u_long diff = off;
1092         u_long st_value;
1093         const Elf_Sym *es;
1094         const Elf_Sym *best = 0;
1095         int i;
1096
1097         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1098                 if (es->st_name == 0)
1099                         continue;
1100                 st_value = es->st_value;
1101                 if (off >= st_value) {
1102                         if (off - st_value < diff) {
1103                                 diff = off - st_value;
1104                                 best = es;
1105                                 if (diff == 0)
1106                                         break;
1107                         } else if (off - st_value == diff) {
1108                                 best = es;
1109                         }
1110                 }
1111         }
1112         if (best == 0)
1113                 *diffp = off;
1114         else
1115                 *diffp = diff;
1116         *sym = (c_linker_sym_t) best;
1117
1118         return 0;
1119 }
1120
1121 /*
1122  * Look up a linker set on an ELF system.
1123  */
1124 static int
1125 link_elf_lookup_set(linker_file_t lf, const char *name,
1126     void ***startp, void ***stopp, int *countp)
1127 {
1128         elf_file_t ef = (elf_file_t)lf;
1129         void **start, **stop;
1130         int i, count;
1131
1132         /* Relative to section number */
1133         for (i = 0; i < ef->nprogtab; i++) {
1134                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1135                     strcmp(ef->progtab[i].name + 4, name) == 0) {
1136                         start  = (void **)ef->progtab[i].addr;
1137                         stop = (void **)((char *)ef->progtab[i].addr +
1138                             ef->progtab[i].size);
1139                         count = stop - start;
1140                         if (startp)
1141                                 *startp = start;
1142                         if (stopp)
1143                                 *stopp = stop;
1144                         if (countp)
1145                                 *countp = count;
1146                         return (0);
1147                 }
1148         }
1149         return (ESRCH);
1150 }
1151
1152 static int
1153 link_elf_each_function_name(linker_file_t file,
1154     int (*callback)(const char *, void *), void *opaque)
1155 {
1156         elf_file_t ef = (elf_file_t)file;
1157         const Elf_Sym *symp;
1158         int i, error;
1159
1160         /* Exhaustive search */
1161         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1162                 if (symp->st_value != 0 &&
1163                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1164                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
1165                         if (error)
1166                                 return (error);
1167                 }
1168         }
1169         return (0);
1170 }
1171
1172 static int
1173 link_elf_each_function_nameval(linker_file_t file,
1174     linker_function_nameval_callback_t callback, void *opaque)
1175 {
1176         linker_symval_t symval;
1177         elf_file_t ef = (elf_file_t)file;
1178         const Elf_Sym* symp;
1179         int i, error;
1180
1181         /* Exhaustive search */
1182         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1183                 if (symp->st_value != 0 &&
1184                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1185                         error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1186                         if (error)
1187                                 return (error);
1188                         error = callback(file, i, &symval, opaque);
1189                         if (error)
1190                                 return (error);
1191                 }
1192         }
1193         return (0);
1194 }
1195
1196 /*
1197  * Symbol lookup function that can be used when the symbol index is known (ie
1198  * in relocations). It uses the symbol index instead of doing a fully fledged
1199  * hash table based lookup when such is valid. For example for local symbols.
1200  * This is not only more efficient, it's also more correct. It's not always
1201  * the case that the symbol can be found through the hash table.
1202  */
1203 static Elf_Addr
1204 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1205 {
1206         elf_file_t ef = (elf_file_t)lf;
1207         const Elf_Sym *sym;
1208         const char *symbol;
1209         Elf_Addr ret;
1210
1211         /* Don't even try to lookup the symbol if the index is bogus. */
1212         if (symidx >= ef->ddbsymcnt)
1213                 return (0);
1214
1215         sym = ef->ddbsymtab + symidx;
1216
1217         /* Quick answer if there is a definition included. */
1218         if (sym->st_shndx != SHN_UNDEF)
1219                 return (sym->st_value);
1220
1221         /* If we get here, then it is undefined and needs a lookup. */
1222         switch (ELF_ST_BIND(sym->st_info)) {
1223         case STB_LOCAL:
1224                 /* Local, but undefined? huh? */
1225                 return (0);
1226
1227         case STB_GLOBAL:
1228                 /* Relative to Data or Function name */
1229                 symbol = ef->ddbstrtab + sym->st_name;
1230
1231                 /* Force a lookup failure if the symbol name is bogus. */
1232                 if (*symbol == 0)
1233                         return (0);
1234                 ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1235                 return ret;
1236
1237         case STB_WEAK:
1238                 printf("link_elf_obj: Weak symbols not supported\n");
1239                 return (0);
1240
1241         default:
1242                 return (0);
1243         }
1244 }
1245
1246 static void
1247 link_elf_fix_link_set(elf_file_t ef)
1248 {
1249         static const char startn[] = "__start_";
1250         static const char stopn[] = "__stop_";
1251         Elf_Sym *sym;
1252         const char *sym_name, *linkset_name;
1253         Elf_Addr startp, stopp;
1254         Elf_Size symidx;
1255         int start, i;
1256
1257         startp = stopp = 0;
1258         for (symidx = 1 /* zero entry is special */;
1259                 symidx < ef->ddbsymcnt; symidx++) {
1260                 sym = ef->ddbsymtab + symidx;
1261                 if (sym->st_shndx != SHN_UNDEF)
1262                         continue;
1263
1264                 sym_name = ef->ddbstrtab + sym->st_name;
1265                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1266                         start = 1;
1267                         linkset_name = sym_name + sizeof(startn) - 1;
1268                 }
1269                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1270                         start = 0;
1271                         linkset_name = sym_name + sizeof(stopn) - 1;
1272                 }
1273                 else
1274                         continue;
1275
1276                 for (i = 0; i < ef->nprogtab; i++) {
1277                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1278                                 startp = (Elf_Addr)ef->progtab[i].addr;
1279                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1280                                 break;
1281                         }
1282                 }
1283                 if (i == ef->nprogtab)
1284                         continue;
1285
1286                 sym->st_value = start ? startp : stopp;
1287                 sym->st_shndx = i;
1288         }
1289 }
1290
1291 static void
1292 link_elf_reloc_local(linker_file_t lf)
1293 {
1294         elf_file_t ef = (elf_file_t)lf;
1295         const Elf_Rel *rellim;
1296         const Elf_Rel *rel;
1297         const Elf_Rela *relalim;
1298         const Elf_Rela *rela;
1299         const Elf_Sym *sym;
1300         Elf_Addr base;
1301         int i;
1302         Elf_Size symidx;
1303
1304         link_elf_fix_link_set(ef);
1305
1306         /* Perform relocations without addend if there are any: */
1307         for (i = 0; i < ef->nreltab; i++) {
1308                 rel = ef->reltab[i].rel;
1309                 if (rel == NULL)
1310                         panic("lost a reltab!");
1311                 rellim = rel + ef->reltab[i].nrel;
1312                 base = findbase(ef, ef->reltab[i].sec);
1313                 if (base == 0)
1314                         panic("lost base for reltab");
1315                 for ( ; rel < rellim; rel++) {
1316                         symidx = ELF_R_SYM(rel->r_info);
1317                         if (symidx >= ef->ddbsymcnt)
1318                                 continue;
1319                         sym = ef->ddbsymtab + symidx;
1320                         /* Only do local relocs */
1321                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1322                                 continue;
1323                         elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1324                             elf_obj_lookup);
1325                 }
1326         }
1327
1328         /* Perform relocations with addend if there are any: */
1329         for (i = 0; i < ef->nrelatab; i++) {
1330                 rela = ef->relatab[i].rela;
1331                 if (rela == NULL)
1332                         panic("lost a relatab!");
1333                 relalim = rela + ef->relatab[i].nrela;
1334                 base = findbase(ef, ef->relatab[i].sec);
1335                 if (base == 0)
1336                         panic("lost base for relatab");
1337                 for ( ; rela < relalim; rela++) {
1338                         symidx = ELF_R_SYM(rela->r_info);
1339                         if (symidx >= ef->ddbsymcnt)
1340                                 continue;
1341                         sym = ef->ddbsymtab + symidx;
1342                         /* Only do local relocs */
1343                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1344                                 continue;
1345                         elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1346                             elf_obj_lookup);
1347                 }
1348         }
1349 }
1350
1351 static long
1352 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1353 {
1354     elf_file_t ef = (elf_file_t)lf;
1355
1356     *symtab = ef->ddbsymtab;
1357
1358     if (*symtab == NULL)
1359         return (0);
1360
1361     return (ef->ddbsymcnt);
1362 }
1363
1364 static long
1365 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1366 {
1367     elf_file_t ef = (elf_file_t)lf;
1368
1369     *strtab = ef->ddbstrtab;
1370
1371     if (*strtab == NULL)
1372         return (0);
1373
1374     return (ef->ddbstrcnt);
1375 }