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