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