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