sys/kern/link_elf_obj.c

   1 /*-
   2  * Copyright (c) 1998-2000 Doug Rabson
   3  * Copyright (c) 2004 Peter Wemm
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27
  28 #include <sys/cdefs.h>
  29 __FBSDID("$FreeBSD$");
  30
  31 #include "opt_ddb.h"
  32
  33 #include <sys/param.h>
  34 #include <sys/systm.h>
  35 #include <sys/kernel.h>
  36 #include <sys/lock.h>
  37 #include <sys/malloc.h>
  38 #include <sys/mutex.h>
  39 #include <sys/mount.h>
  40 #include <sys/proc.h>
  41 #include <sys/namei.h>
  42 #include <sys/fcntl.h>
  43 #include <sys/vnode.h>
  44 #include <sys/linker.h>
  45
  46 #include <machine/elf.h>
  47
  48 #include <net/vnet.h>
  49
  50 #include <security/mac/mac_framework.h>
  51
  52 #include <vm/vm.h>
  53 #include <vm/vm_param.h>
  54 #include <vm/vm_object.h>
  55 #include <vm/vm_kern.h>
  56 #include <vm/vm_extern.h>
  57 #include <vm/pmap.h>
  58 #include <vm/vm_map.h>
  59
  60 #include <sys/link_elf.h>
  61
  62 #ifdef DDB_CTF
  63 #include <net/zlib.h>
  64 #endif
  65
  66 #include "linker_if.h"
  67
  68 typedef struct {
  69         void            *addr;
  70         Elf_Off         size;
  71         int             flags;
  72         int             sec;    /* Original section */
  73         char            *name;
  74 } Elf_progent;
  75
  76 typedef struct {
  77         Elf_Rel         *rel;
  78         int             nrel;
  79         int             sec;
  80 } Elf_relent;
  81
  82 typedef struct {
  83         Elf_Rela        *rela;
  84         int             nrela;
  85         int             sec;
  86 } Elf_relaent;
  87
  88
  89 typedef struct elf_file {
  90         struct linker_file lf;          /* Common fields */
  91
  92         int             preloaded;
  93         caddr_t         address;        /* Relocation address */
  94         vm_object_t     object;         /* VM object to hold file pages */
  95         Elf_Shdr        *e_shdr;
  96
  97         Elf_progent     *progtab;
  98         int             nprogtab;
  99
 100         Elf_relaent     *relatab;
 101         int             nrelatab;
 102
 103         Elf_relent      *reltab;
 104         int             nreltab;
 105
 106         Elf_Sym         *ddbsymtab;     /* The symbol table we are using */
 107         long            ddbsymcnt;      /* Number of symbols */
 108         caddr_t         ddbstrtab;      /* String table */
 109         long            ddbstrcnt;      /* number of bytes in string table */
 110
 111         caddr_t         shstrtab;       /* Section name string table */
 112         long            shstrcnt;       /* number of bytes in string table */
 113
 114         caddr_t         ctftab;         /* CTF table */
 115         long            ctfcnt;         /* number of bytes in CTF table */
 116         caddr_t         ctfoff;         /* CTF offset table */
 117         caddr_t         typoff;         /* Type offset table */
 118         long            typlen;         /* Number of type entries. */
 119
 120 } *elf_file_t;
 121
 122 #include <kern/kern_ctf.c>
 123
 124 static int      link_elf_link_preload(linker_class_t cls,
 125                     const char *, linker_file_t *);
 126 static int      link_elf_link_preload_finish(linker_file_t);
 127 static int      link_elf_load_file(linker_class_t, const char *, linker_file_t *);
 128 static int      link_elf_lookup_symbol(linker_file_t, const char *,
 129                     c_linker_sym_t *);
 130 static int      link_elf_symbol_values(linker_file_t, c_linker_sym_t,
 131                     linker_symval_t *);
 132 static int      link_elf_search_symbol(linker_file_t, caddr_t value,
 133                     c_linker_sym_t *sym, long *diffp);
 134
 135 static void     link_elf_unload_file(linker_file_t);
 136 static int      link_elf_lookup_set(linker_file_t, const char *,
 137                     void ***, void ***, int *);
 138 static int      link_elf_each_function_name(linker_file_t,
 139                     int (*)(const char *, void *), void *);
 140 static int      link_elf_each_function_nameval(linker_file_t,
 141                                 linker_function_nameval_callback_t,
 142                                 void *);
 143 static void     link_elf_reloc_local(linker_file_t);
 144 static long     link_elf_symtab_get(linker_file_t, const Elf_Sym **);
 145 static long     link_elf_strtab_get(linker_file_t, caddr_t *);
 146
 147 static int      elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps,
 148                     Elf_Addr *);
 149
 150 static kobj_method_t link_elf_methods[] = {
 151         KOBJMETHOD(linker_lookup_symbol,        link_elf_lookup_symbol),
 152         KOBJMETHOD(linker_symbol_values,        link_elf_symbol_values),
 153         KOBJMETHOD(linker_search_symbol,        link_elf_search_symbol),
 154         KOBJMETHOD(linker_unload,               link_elf_unload_file),
 155         KOBJMETHOD(linker_load_file,            link_elf_load_file),
 156         KOBJMETHOD(linker_link_preload,         link_elf_link_preload),
 157         KOBJMETHOD(linker_link_preload_finish,  link_elf_link_preload_finish),
 158         KOBJMETHOD(linker_lookup_set,           link_elf_lookup_set),
 159         KOBJMETHOD(linker_each_function_name,   link_elf_each_function_name),
 160         KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
 161         KOBJMETHOD(linker_ctf_get,              link_elf_ctf_get),
 162         KOBJMETHOD(linker_symtab_get,           link_elf_symtab_get),
 163         KOBJMETHOD(linker_strtab_get,           link_elf_strtab_get),
 164         { 0, 0 }
 165 };
 166
 167 static struct linker_class link_elf_class = {
 168 #if ELF_TARG_CLASS == ELFCLASS32
 169         "elf32_obj",
 170 #else
 171         "elf64_obj",
 172 #endif
 173         link_elf_methods, sizeof(struct elf_file)
 174 };
 175
 176 static int      relocate_file(elf_file_t ef);
 177 static void     elf_obj_cleanup_globals_cache(elf_file_t);
 178
 179 static void
 180 link_elf_error(const char *filename, const char *s)
 181 {
 182         if (filename == NULL)
 183                 printf("kldload: %s\n", s);
 184         else
 185                 printf("kldload: %s: %s\n", filename, s);
 186 }
 187
 188 static void
 189 link_elf_init(void *arg)
 190 {
 191
 192         linker_add_class(&link_elf_class);
 193 }
 194
 195 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
 196
 197 static int
 198 link_elf_link_preload(linker_class_t cls, const char *filename,
 199     linker_file_t *result)
 200 {
 201         Elf_Ehdr *hdr;
 202         Elf_Shdr *shdr;
 203         Elf_Sym *es;
 204         void *modptr, *baseptr, *sizeptr;
 205         char *type;
 206         elf_file_t ef;
 207         linker_file_t lf;
 208         Elf_Addr off;
 209         int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
 210
 211         /* Look to see if we have the file preloaded */
 212         modptr = preload_search_by_name(filename);
 213         if (modptr == NULL)
 214                 return ENOENT;
 215
 216         type = (char *)preload_search_info(modptr, MODINFO_TYPE);
 217         baseptr = preload_search_info(modptr, MODINFO_ADDR);
 218         sizeptr = preload_search_info(modptr, MODINFO_SIZE);
 219         hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
 220             MODINFOMD_ELFHDR);
 221         shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
 222             MODINFOMD_SHDR);
 223         if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
 224             " obj module") != 0 &&
 225             strcmp(type, "elf obj module") != 0)) {
 226                 return (EFTYPE);
 227         }
 228         if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
 229             shdr == NULL)
 230                 return (EINVAL);
 231
 232         lf = linker_make_file(filename, &link_elf_class);
 233         if (lf == NULL)
 234                 return (ENOMEM);
 235
 236         ef = (elf_file_t)lf;
 237         ef->preloaded = 1;
 238         ef->address = *(caddr_t *)baseptr;
 239         lf->address = *(caddr_t *)baseptr;
 240         lf->size = *(size_t *)sizeptr;
 241
 242         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
 243             hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
 244             hdr->e_ident[EI_VERSION] != EV_CURRENT ||
 245             hdr->e_version != EV_CURRENT ||
 246             hdr->e_type != ET_REL ||
 247             hdr->e_machine != ELF_TARG_MACH) {
 248                 error = EFTYPE;
 249                 goto out;
 250         }
 251         ef->e_shdr = shdr;
 252
 253         /* Scan the section header for information and table sizing. */
 254         symtabindex = -1;
 255         symstrindex = -1;
 256         for (i = 0; i < hdr->e_shnum; i++) {
 257                 switch (shdr[i].sh_type) {
 258                 case SHT_PROGBITS:
 259                 case SHT_NOBITS:
 260 #ifdef __amd64__
 261                 case SHT_AMD64_UNWIND:
 262 #endif
 263                         ef->nprogtab++;
 264                         break;
 265                 case SHT_SYMTAB:
 266                         symtabindex = i;
 267                         symstrindex = shdr[i].sh_link;
 268                         break;
 269                 case SHT_REL:
 270                         ef->nreltab++;
 271                         break;
 272                 case SHT_RELA:
 273                         ef->nrelatab++;
 274                         break;
 275                 }
 276         }
 277
 278         shstrindex = hdr->e_shstrndx;
 279         if (ef->nprogtab == 0 || symstrindex < 0 ||
 280             symstrindex >= hdr->e_shnum ||
 281             shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
 282             shstrindex >= hdr->e_shnum ||
 283             shdr[shstrindex].sh_type != SHT_STRTAB) {
 284                 printf("%s: bad/missing section headers\n", filename);
 285                 error = ENOEXEC;
 286                 goto out;
 287         }
 288
 289         /* Allocate space for tracking the load chunks */
 290         if (ef->nprogtab != 0)
 291                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 292                     M_LINKER, M_WAITOK | M_ZERO);
 293         if (ef->nreltab != 0)
 294                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 295                     M_LINKER, M_WAITOK | M_ZERO);
 296         if (ef->nrelatab != 0)
 297                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 298                     M_LINKER, M_WAITOK | M_ZERO);
 299         if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
 300             (ef->nreltab != 0 && ef->reltab == NULL) ||
 301             (ef->nrelatab != 0 && ef->relatab == NULL)) {
 302                 error = ENOMEM;
 303                 goto out;
 304         }
 305
 306         /* XXX, relocate the sh_addr fields saved by the loader. */
 307         off = 0;
 308         for (i = 0; i < hdr->e_shnum; i++) {
 309                 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
 310                         off = shdr[i].sh_addr;
 311         }
 312         for (i = 0; i < hdr->e_shnum; i++) {
 313                 if (shdr[i].sh_addr != 0)
 314                         shdr[i].sh_addr = shdr[i].sh_addr - off +
 315                             (Elf_Addr)ef->address;
 316         }
 317
 318         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 319         ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
 320         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 321         ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
 322         ef->shstrcnt = shdr[shstrindex].sh_size;
 323         ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
 324
 325         /* Now fill out progtab and the relocation tables. */
 326         pb = 0;
 327         rl = 0;
 328         ra = 0;
 329         for (i = 0; i < hdr->e_shnum; i++) {
 330                 switch (shdr[i].sh_type) {
 331                 case SHT_PROGBITS:
 332                 case SHT_NOBITS:
 333 #ifdef __amd64__
 334                 case SHT_AMD64_UNWIND:
 335 #endif
 336                         ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
 337                         if (shdr[i].sh_type == SHT_PROGBITS)
 338                                 ef->progtab[pb].name = "<<PROGBITS>>";
 339 #ifdef __amd64__
 340                         else if (shdr[i].sh_type == SHT_AMD64_UNWIND)
 341                                 ef->progtab[pb].name = "<<UNWIND>>";
 342 #endif
 343                         else
 344                                 ef->progtab[pb].name = "<<NOBITS>>";
 345                         ef->progtab[pb].size = shdr[i].sh_size;
 346                         ef->progtab[pb].sec = i;
 347                         if (ef->shstrtab && shdr[i].sh_name != 0)
 348                                 ef->progtab[pb].name =
 349                                     ef->shstrtab + shdr[i].sh_name;
 350                         if (ef->progtab[pb].name != NULL &&
 351                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
 352                                 void *dpcpu;
 353
 354                                 dpcpu = dpcpu_alloc(shdr[i].sh_size);
 355                                 if (dpcpu == NULL) {
 356                                         error = ENOSPC;
 357                                         goto out;
 358                                 }
 359                                 memcpy(dpcpu, ef->progtab[pb].addr,
 360                                     ef->progtab[pb].size);
 361                                 dpcpu_copy(dpcpu, shdr[i].sh_size);
 362                                 ef->progtab[pb].addr = dpcpu;
 363 #ifdef VIMAGE
 364                         } else if (ef->progtab[pb].name != NULL &&
 365                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
 366                                 void *vnet_data;
 367
 368                                 vnet_data = vnet_data_alloc(shdr[i].sh_size);
 369                                 if (vnet_data == NULL) {
 370                                         error = ENOSPC;
 371                                         goto out;
 372                                 }
 373                                 memcpy(vnet_data, ef->progtab[pb].addr,
 374                                     ef->progtab[pb].size);
 375                                 vnet_data_copy(vnet_data, shdr[i].sh_size);
 376                                 ef->progtab[pb].addr = vnet_data;
 377 #endif
 378                         }
 379
 380                         /* Update all symbol values with the offset. */
 381                         for (j = 0; j < ef->ddbsymcnt; j++) {
 382                                 es = &ef->ddbsymtab[j];
 383                                 if (es->st_shndx != i)
 384                                         continue;
 385                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 386                         }
 387                         pb++;
 388                         break;
 389                 case SHT_REL:
 390                         ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
 391                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 392                         ef->reltab[rl].sec = shdr[i].sh_info;
 393                         rl++;
 394                         break;
 395                 case SHT_RELA:
 396                         ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
 397                         ef->relatab[ra].nrela =
 398                             shdr[i].sh_size / sizeof(Elf_Rela);
 399                         ef->relatab[ra].sec = shdr[i].sh_info;
 400                         ra++;
 401                         break;
 402                 }
 403         }
 404         if (pb != ef->nprogtab)
 405                 panic("lost progbits");
 406         if (rl != ef->nreltab)
 407                 panic("lost reltab");
 408         if (ra != ef->nrelatab)
 409                 panic("lost relatab");
 410
 411         /* Local intra-module relocations */
 412         link_elf_reloc_local(lf);
 413
 414         *result = lf;
 415         return (0);
 416
 417 out:
 418         /* preload not done this way */
 419         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 420         return (error);
 421 }
 422
 423 static int
 424 link_elf_link_preload_finish(linker_file_t lf)
 425 {
 426         elf_file_t ef;
 427         int error;
 428
 429         ef = (elf_file_t)lf;
 430         error = relocate_file(ef);
 431         if (error)
 432                 return error;
 433
 434         /* Notify MD code that a module is being loaded. */
 435         error = elf_cpu_load_file(lf);
 436         if (error)
 437                 return (error);
 438
 439         return (0);
 440 }
 441
 442 static int
 443 link_elf_load_file(linker_class_t cls, const char *filename,
 444     linker_file_t *result)
 445 {
 446         struct nameidata nd;
 447         struct thread *td = curthread;  /* XXX */
 448         Elf_Ehdr *hdr;
 449         Elf_Shdr *shdr;
 450         Elf_Sym *es;
 451         int nbytes, i, j;
 452         vm_offset_t mapbase;
 453         size_t mapsize;
 454         int error = 0;
 455         ssize_t resid;
 456         int flags;
 457         elf_file_t ef;
 458         linker_file_t lf;
 459         int symtabindex;
 460         int symstrindex;
 461         int shstrindex;
 462         int nsym;
 463         int pb, rl, ra;
 464         int alignmask;
 465
 466         shdr = NULL;
 467         lf = NULL;
 468         mapsize = 0;
 469         hdr = NULL;
 470
 471         NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
 472         flags = FREAD;
 473         error = vn_open(&nd, &flags, 0, NULL);
 474         if (error)
 475                 return error;
 476         NDFREE(&nd, NDF_ONLY_PNBUF);
 477         if (nd.ni_vp->v_type != VREG) {
 478                 error = ENOEXEC;
 479                 goto out;
 480         }
 481 #ifdef MAC
 482         error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
 483         if (error) {
 484                 goto out;
 485         }
 486 #endif
 487
 488         /* Read the elf header from the file. */
 489         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
 490         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
 491             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 492             &resid, td);
 493         if (error)
 494                 goto out;
 495         if (resid != 0){
 496                 error = ENOEXEC;
 497                 goto out;
 498         }
 499
 500         if (!IS_ELF(*hdr)) {
 501                 error = ENOEXEC;
 502                 goto out;
 503         }
 504
 505         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
 506             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
 507                 link_elf_error(filename, "Unsupported file layout");
 508                 error = ENOEXEC;
 509                 goto out;
 510         }
 511         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
 512             || hdr->e_version != EV_CURRENT) {
 513                 link_elf_error(filename, "Unsupported file version");
 514                 error = ENOEXEC;
 515                 goto out;
 516         }
 517         if (hdr->e_type != ET_REL) {
 518                 error = ENOSYS;
 519                 goto out;
 520         }
 521         if (hdr->e_machine != ELF_TARG_MACH) {
 522                 link_elf_error(filename, "Unsupported machine");
 523                 error = ENOEXEC;
 524                 goto out;
 525         }
 526
 527         lf = linker_make_file(filename, &link_elf_class);
 528         if (!lf) {
 529                 error = ENOMEM;
 530                 goto out;
 531         }
 532         ef = (elf_file_t) lf;
 533         ef->nprogtab = 0;
 534         ef->e_shdr = 0;
 535         ef->nreltab = 0;
 536         ef->nrelatab = 0;
 537
 538         /* Allocate and read in the section header */
 539         nbytes = hdr->e_shnum * hdr->e_shentsize;
 540         if (nbytes == 0 || hdr->e_shoff == 0 ||
 541             hdr->e_shentsize != sizeof(Elf_Shdr)) {
 542                 error = ENOEXEC;
 543                 goto out;
 544         }
 545         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
 546         ef->e_shdr = shdr;
 547         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
 548             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
 549         if (error)
 550                 goto out;
 551         if (resid) {
 552                 error = ENOEXEC;
 553                 goto out;
 554         }
 555
 556         /* Scan the section header for information and table sizing. */
 557         nsym = 0;
 558         symtabindex = -1;
 559         symstrindex = -1;
 560         for (i = 0; i < hdr->e_shnum; i++) {
 561                 if (shdr[i].sh_size == 0)
 562                         continue;
 563                 switch (shdr[i].sh_type) {
 564                 case SHT_PROGBITS:
 565                 case SHT_NOBITS:
 566 #ifdef __amd64__
 567                 case SHT_AMD64_UNWIND:
 568 #endif
 569                         ef->nprogtab++;
 570                         break;
 571                 case SHT_SYMTAB:
 572                         nsym++;
 573                         symtabindex = i;
 574                         symstrindex = shdr[i].sh_link;
 575                         break;
 576                 case SHT_REL:
 577                         ef->nreltab++;
 578                         break;
 579                 case SHT_RELA:
 580                         ef->nrelatab++;
 581                         break;
 582                 case SHT_STRTAB:
 583                         break;
 584                 }
 585         }
 586         if (ef->nprogtab == 0) {
 587                 link_elf_error(filename, "file has no contents");
 588                 error = ENOEXEC;
 589                 goto out;
 590         }
 591         if (nsym != 1) {
 592                 /* Only allow one symbol table for now */
 593                 link_elf_error(filename, "file has no valid symbol table");
 594                 error = ENOEXEC;
 595                 goto out;
 596         }
 597         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
 598             shdr[symstrindex].sh_type != SHT_STRTAB) {
 599                 link_elf_error(filename, "file has invalid symbol strings");
 600                 error = ENOEXEC;
 601                 goto out;
 602         }
 603
 604         /* Allocate space for tracking the load chunks */
 605         if (ef->nprogtab != 0)
 606                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 607                     M_LINKER, M_WAITOK | M_ZERO);
 608         if (ef->nreltab != 0)
 609                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 610                     M_LINKER, M_WAITOK | M_ZERO);
 611         if (ef->nrelatab != 0)
 612                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 613                     M_LINKER, M_WAITOK | M_ZERO);
 614
 615         if (symtabindex == -1)
 616                 panic("lost symbol table index");
 617         /* Allocate space for and load the symbol table */
 618         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 619         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
 620         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
 621             shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
 622             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 623             &resid, td);
 624         if (error)
 625                 goto out;
 626         if (resid != 0){
 627                 error = EINVAL;
 628                 goto out;
 629         }
 630
 631         if (symstrindex == -1)
 632                 panic("lost symbol string index");
 633         /* Allocate space for and load the symbol strings */
 634         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 635         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
 636         error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
 637             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
 638             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 639             &resid, td);
 640         if (error)
 641                 goto out;
 642         if (resid != 0){
 643                 error = EINVAL;
 644                 goto out;
 645         }
 646
 647         /* Do we have a string table for the section names?  */
 648         shstrindex = -1;
 649         if (hdr->e_shstrndx != 0 &&
 650             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
 651                 shstrindex = hdr->e_shstrndx;
 652                 ef->shstrcnt = shdr[shstrindex].sh_size;
 653                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
 654                     M_WAITOK);
 655                 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
 656                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
 657                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 658                     &resid, td);
 659                 if (error)
 660                         goto out;
 661                 if (resid != 0){
 662                         error = EINVAL;
 663                         goto out;
 664                 }
 665         }
 666
 667         /* Size up code/data(progbits) and bss(nobits). */
 668         alignmask = 0;
 669         for (i = 0; i < hdr->e_shnum; i++) {
 670                 if (shdr[i].sh_size == 0)
 671                         continue;
 672                 switch (shdr[i].sh_type) {
 673                 case SHT_PROGBITS:
 674                 case SHT_NOBITS:
 675 #ifdef __amd64__
 676                 case SHT_AMD64_UNWIND:
 677 #endif
 678                         alignmask = shdr[i].sh_addralign - 1;
 679                         mapsize += alignmask;
 680                         mapsize &= ~alignmask;
 681                         mapsize += shdr[i].sh_size;
 682                         break;
 683                 }
 684         }
 685
 686         /*
 687          * We know how much space we need for the text/data/bss/etc.
 688          * This stuff needs to be in a single chunk so that profiling etc
 689          * can get the bounds and gdb can associate offsets with modules
 690          */
 691         ef->object = vm_object_allocate(OBJT_DEFAULT,
 692             round_page(mapsize) >> PAGE_SHIFT);
 693         if (ef->object == NULL) {
 694                 error = ENOMEM;
 695                 goto out;
 696         }
 697         ef->address = (caddr_t) vm_map_min(kernel_map);
 698
 699         /*
 700          * In order to satisfy amd64's architectural requirements on the
 701          * location of code and data in the kernel's address space, request a
 702          * mapping that is above the kernel.
 703          */
 704 #ifdef __amd64__
 705         mapbase = KERNBASE;
 706 #else
 707         mapbase = VM_MIN_KERNEL_ADDRESS;
 708 #endif
 709         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
 710             round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
 711             VM_PROT_ALL, 0);
 712         if (error) {
 713                 vm_object_deallocate(ef->object);
 714                 ef->object = 0;
 715                 goto out;
 716         }
 717
 718         /* Wire the pages */
 719         error = vm_map_wire(kernel_map, mapbase,
 720             mapbase + round_page(mapsize),
 721             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 722         if (error != KERN_SUCCESS) {
 723                 error = ENOMEM;
 724                 goto out;
 725         }
 726
 727         /* Inform the kld system about the situation */
 728         lf->address = ef->address = (caddr_t)mapbase;
 729         lf->size = mapsize;
 730
 731         /*
 732          * Now load code/data(progbits), zero bss(nobits), allocate space for
 733          * and load relocs
 734          */
 735         pb = 0;
 736         rl = 0;
 737         ra = 0;
 738         alignmask = 0;
 739         for (i = 0; i < hdr->e_shnum; i++) {
 740                 if (shdr[i].sh_size == 0)
 741                         continue;
 742                 switch (shdr[i].sh_type) {
 743                 case SHT_PROGBITS:
 744                 case SHT_NOBITS:
 745 #ifdef __amd64__
 746                 case SHT_AMD64_UNWIND:
 747 #endif
 748                         alignmask = shdr[i].sh_addralign - 1;
 749                         mapbase += alignmask;
 750                         mapbase &= ~alignmask;
 751                         if (ef->shstrtab && shdr[i].sh_name != 0)
 752                                 ef->progtab[pb].name =
 753                                     ef->shstrtab + shdr[i].sh_name;
 754                         else if (shdr[i].sh_type == SHT_PROGBITS)
 755                                 ef->progtab[pb].name = "<<PROGBITS>>";
 756 #ifdef __amd64__
 757                         else if (shdr[i].sh_type == SHT_AMD64_UNWIND)
 758                                 ef->progtab[pb].name = "<<UNWIND>>";
 759 #endif
 760                         else
 761                                 ef->progtab[pb].name = "<<NOBITS>>";
 762                         if (ef->progtab[pb].name != NULL &&
 763                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 764                                 ef->progtab[pb].addr =
 765                                     dpcpu_alloc(shdr[i].sh_size);
 766 #ifdef VIMAGE
 767                         else if (ef->progtab[pb].name != NULL &&
 768                             !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 769                                 ef->progtab[pb].addr =
 770                                     vnet_data_alloc(shdr[i].sh_size);
 771 #endif
 772                         else
 773                                 ef->progtab[pb].addr =
 774                                     (void *)(uintptr_t)mapbase;
 775                         if (ef->progtab[pb].addr == NULL) {
 776                                 error = ENOSPC;
 777                                 goto out;
 778                         }
 779                         ef->progtab[pb].size = shdr[i].sh_size;
 780                         ef->progtab[pb].sec = i;
 781                         if (shdr[i].sh_type == SHT_PROGBITS
 782 #ifdef __amd64__
 783                             || shdr[i].sh_type == SHT_AMD64_UNWIND
 784 #endif
 785                             ) {
 786                                 error = vn_rdwr(UIO_READ, nd.ni_vp,
 787                                     ef->progtab[pb].addr,
 788                                     shdr[i].sh_size, shdr[i].sh_offset,
 789                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
 790                                     NOCRED, &resid, td);
 791                                 if (error)
 792                                         goto out;
 793                                 if (resid != 0){
 794                                         error = EINVAL;
 795                                         goto out;
 796                                 }
 797                                 /* Initialize the per-cpu or vnet area. */
 798                                 if (ef->progtab[pb].addr != (void *)mapbase &&
 799                                     !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 800                                         dpcpu_copy(ef->progtab[pb].addr,
 801                                             shdr[i].sh_size);
 802 #ifdef VIMAGE
 803                                 else if (ef->progtab[pb].addr !=
 804                                     (void *)mapbase &&
 805                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 806                                         vnet_data_copy(ef->progtab[pb].addr,
 807                                             shdr[i].sh_size);
 808 #endif
 809                         } else
 810                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
 811
 812                         /* Update all symbol values with the offset. */
 813                         for (j = 0; j < ef->ddbsymcnt; j++) {
 814                                 es = &ef->ddbsymtab[j];
 815                                 if (es->st_shndx != i)
 816                                         continue;
 817                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 818                         }
 819                         mapbase += shdr[i].sh_size;
 820                         pb++;
 821                         break;
 822                 case SHT_REL:
 823                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
 824                             M_WAITOK);
 825                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 826                         ef->reltab[rl].sec = shdr[i].sh_info;
 827                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 828                             (void *)ef->reltab[rl].rel,
 829                             shdr[i].sh_size, shdr[i].sh_offset,
 830                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 831                             &resid, td);
 832                         if (error)
 833                                 goto out;
 834                         if (resid != 0){
 835                                 error = EINVAL;
 836                                 goto out;
 837                         }
 838                         rl++;
 839                         break;
 840                 case SHT_RELA:
 841                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
 842                             M_WAITOK);
 843                         ef->relatab[ra].nrela =
 844                             shdr[i].sh_size / sizeof(Elf_Rela);
 845                         ef->relatab[ra].sec = shdr[i].sh_info;
 846                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 847                             (void *)ef->relatab[ra].rela,
 848                             shdr[i].sh_size, shdr[i].sh_offset,
 849                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 850                             &resid, td);
 851                         if (error)
 852                                 goto out;
 853                         if (resid != 0){
 854                                 error = EINVAL;
 855                                 goto out;
 856                         }
 857                         ra++;
 858                         break;
 859                 }
 860         }
 861         if (pb != ef->nprogtab)
 862                 panic("lost progbits");
 863         if (rl != ef->nreltab)
 864                 panic("lost reltab");
 865         if (ra != ef->nrelatab)
 866                 panic("lost relatab");
 867         if (mapbase != (vm_offset_t)ef->address + mapsize)
 868                 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
 869                     (u_long)mapbase, ef->address, (u_long)mapsize,
 870                     (u_long)(vm_offset_t)ef->address + mapsize);
 871
 872         /* Local intra-module relocations */
 873         link_elf_reloc_local(lf);
 874
 875         /* Pull in dependencies */
 876         VOP_UNLOCK(nd.ni_vp, 0);
 877         error = linker_load_dependencies(lf);
 878         vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
 879         if (error)
 880                 goto out;
 881
 882         /* External relocations */
 883         error = relocate_file(ef);
 884         if (error)
 885                 goto out;
 886
 887         /* Notify MD code that a module is being loaded. */
 888         error = elf_cpu_load_file(lf);
 889         if (error)
 890                 goto out;
 891
 892         *result = lf;
 893
 894 out:
 895         VOP_UNLOCK(nd.ni_vp, 0);
 896         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
 897         if (error && lf)
 898                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 899         if (hdr)
 900                 free(hdr, M_LINKER);
 901
 902         return error;
 903 }
 904
 905 static void
 906 link_elf_unload_file(linker_file_t file)
 907 {
 908         elf_file_t ef = (elf_file_t) file;
 909         int i;
 910
 911         /* Notify MD code that a module is being unloaded. */
 912         elf_cpu_unload_file(file);
 913
 914         if (ef->progtab) {
 915                 for (i = 0; i < ef->nprogtab; i++) {
 916                         if (ef->progtab[i].size == 0)
 917                                 continue;
 918                         if (ef->progtab[i].name == NULL)
 919                                 continue;
 920                         if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
 921                                 dpcpu_free(ef->progtab[i].addr,
 922                                     ef->progtab[i].size);
 923 #ifdef VIMAGE
 924                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
 925                                 vnet_data_free(ef->progtab[i].addr,
 926                                     ef->progtab[i].size);
 927 #endif
 928                 }
 929         }
 930         if (ef->preloaded) {
 931                 if (ef->reltab)
 932                         free(ef->reltab, M_LINKER);
 933                 if (ef->relatab)
 934                         free(ef->relatab, M_LINKER);
 935                 if (ef->progtab)
 936                         free(ef->progtab, M_LINKER);
 937                 if (ef->ctftab)
 938                         free(ef->ctftab, M_LINKER);
 939                 if (ef->ctfoff)
 940                         free(ef->ctfoff, M_LINKER);
 941                 if (ef->typoff)
 942                         free(ef->typoff, M_LINKER);
 943                 if (file->filename != NULL)
 944                         preload_delete_name(file->filename);
 945                 /* XXX reclaim module memory? */
 946                 return;
 947         }
 948
 949         for (i = 0; i < ef->nreltab; i++)
 950                 if (ef->reltab[i].rel)
 951                         free(ef->reltab[i].rel, M_LINKER);
 952         for (i = 0; i < ef->nrelatab; i++)
 953                 if (ef->relatab[i].rela)
 954                         free(ef->relatab[i].rela, M_LINKER);
 955         if (ef->reltab)
 956                 free(ef->reltab, M_LINKER);
 957         if (ef->relatab)
 958                 free(ef->relatab, M_LINKER);
 959         if (ef->progtab)
 960                 free(ef->progtab, M_LINKER);
 961
 962         if (ef->object) {
 963                 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
 964                     (vm_offset_t) ef->address +
 965                     (ef->object->size << PAGE_SHIFT));
 966         }
 967         if (ef->e_shdr)
 968                 free(ef->e_shdr, M_LINKER);
 969         if (ef->ddbsymtab)
 970                 free(ef->ddbsymtab, M_LINKER);
 971         if (ef->ddbstrtab)
 972                 free(ef->ddbstrtab, M_LINKER);
 973         if (ef->shstrtab)
 974                 free(ef->shstrtab, M_LINKER);
 975         if (ef->ctftab)
 976                 free(ef->ctftab, M_LINKER);
 977         if (ef->ctfoff)
 978                 free(ef->ctfoff, M_LINKER);
 979         if (ef->typoff)
 980                 free(ef->typoff, M_LINKER);
 981 }
 982
 983 static const char *
 984 symbol_name(elf_file_t ef, Elf_Size r_info)
 985 {
 986         const Elf_Sym *ref;
 987
 988         if (ELF_R_SYM(r_info)) {
 989                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
 990                 return ef->ddbstrtab + ref->st_name;
 991         } else
 992                 return NULL;
 993 }
 994
 995 static Elf_Addr
 996 findbase(elf_file_t ef, int sec)
 997 {
 998         int i;
 999         Elf_Addr base = 0;
1000
1001         for (i = 0; i < ef->nprogtab; i++) {
1002                 if (sec == ef->progtab[i].sec) {
1003                         base = (Elf_Addr)ef->progtab[i].addr;
1004                         break;
1005                 }
1006         }
1007         return base;
1008 }
1009
1010 static int
1011 relocate_file(elf_file_t ef)
1012 {
1013         const Elf_Rel *rellim;
1014         const Elf_Rel *rel;
1015         const Elf_Rela *relalim;
1016         const Elf_Rela *rela;
1017         const char *symname;
1018         const Elf_Sym *sym;
1019         int i;
1020         Elf_Size symidx;
1021         Elf_Addr base;
1022
1023
1024         /* Perform relocations without addend if there are any: */
1025         for (i = 0; i < ef->nreltab; i++) {
1026                 rel = ef->reltab[i].rel;
1027                 if (rel == NULL)
1028                         panic("lost a reltab!");
1029                 rellim = rel + ef->reltab[i].nrel;
1030                 base = findbase(ef, ef->reltab[i].sec);
1031                 if (base == 0)
1032                         panic("lost base for reltab");
1033                 for ( ; rel < rellim; rel++) {
1034                         symidx = ELF_R_SYM(rel->r_info);
1035                         if (symidx >= ef->ddbsymcnt)
1036                                 continue;
1037                         sym = ef->ddbsymtab + symidx;
1038                         /* Local relocs are already done */
1039                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1040                                 continue;
1041                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1042                             elf_obj_lookup)) {
1043                                 symname = symbol_name(ef, rel->r_info);
1044                                 printf("link_elf_obj: symbol %s undefined\n",
1045                                     symname);
1046                                 return ENOENT;
1047                         }
1048                 }
1049         }
1050
1051         /* Perform relocations with addend if there are any: */
1052         for (i = 0; i < ef->nrelatab; i++) {
1053                 rela = ef->relatab[i].rela;
1054                 if (rela == NULL)
1055                         panic("lost a relatab!");
1056                 relalim = rela + ef->relatab[i].nrela;
1057                 base = findbase(ef, ef->relatab[i].sec);
1058                 if (base == 0)
1059                         panic("lost base for relatab");
1060                 for ( ; rela < relalim; rela++) {
1061                         symidx = ELF_R_SYM(rela->r_info);
1062                         if (symidx >= ef->ddbsymcnt)
1063                                 continue;
1064                         sym = ef->ddbsymtab + symidx;
1065                         /* Local relocs are already done */
1066                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1067                                 continue;
1068                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1069                             elf_obj_lookup)) {
1070                                 symname = symbol_name(ef, rela->r_info);
1071                                 printf("link_elf_obj: symbol %s undefined\n",
1072                                     symname);
1073                                 return ENOENT;
1074                         }
1075                 }
1076         }
1077
1078         /*
1079          * Only clean SHN_FBSD_CACHED for successfull return.  If we
1080          * modified symbol table for the object but found an
1081          * unresolved symbol, there is no reason to roll back.
1082          */
1083         elf_obj_cleanup_globals_cache(ef);
1084
1085         return 0;
1086 }
1087
1088 static int
1089 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1090 {
1091         elf_file_t ef = (elf_file_t) lf;
1092         const Elf_Sym *symp;
1093         const char *strp;
1094         int i;
1095
1096         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1097                 strp = ef->ddbstrtab + symp->st_name;
1098                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1099                         *sym = (c_linker_sym_t) symp;
1100                         return 0;
1101                 }
1102         }
1103         return ENOENT;
1104 }
1105
1106 static int
1107 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1108     linker_symval_t *symval)
1109 {
1110         elf_file_t ef = (elf_file_t) lf;
1111         const Elf_Sym *es = (const Elf_Sym*) sym;
1112
1113         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1114                 symval->name = ef->ddbstrtab + es->st_name;
1115                 symval->value = (caddr_t)es->st_value;
1116                 symval->size = es->st_size;
1117                 return 0;
1118         }
1119         return ENOENT;
1120 }
1121
1122 static int
1123 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1124     c_linker_sym_t *sym, long *diffp)
1125 {
1126         elf_file_t ef = (elf_file_t) lf;
1127         u_long off = (uintptr_t) (void *) value;
1128         u_long diff = off;
1129         u_long st_value;
1130         const Elf_Sym *es;
1131         const Elf_Sym *best = 0;
1132         int i;
1133
1134         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1135                 if (es->st_name == 0)
1136                         continue;
1137                 st_value = es->st_value;
1138                 if (off >= st_value) {
1139                         if (off - st_value < diff) {
1140                                 diff = off - st_value;
1141                                 best = es;
1142                                 if (diff == 0)
1143                                         break;
1144                         } else if (off - st_value == diff) {
1145                                 best = es;
1146                         }
1147                 }
1148         }
1149         if (best == 0)
1150                 *diffp = off;
1151         else
1152                 *diffp = diff;
1153         *sym = (c_linker_sym_t) best;
1154
1155         return 0;
1156 }
1157
1158 /*
1159  * Look up a linker set on an ELF system.
1160  */
1161 static int
1162 link_elf_lookup_set(linker_file_t lf, const char *name,
1163     void ***startp, void ***stopp, int *countp)
1164 {
1165         elf_file_t ef = (elf_file_t)lf;
1166         void **start, **stop;
1167         int i, count;
1168
1169         /* Relative to section number */
1170         for (i = 0; i < ef->nprogtab; i++) {
1171                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1172                     strcmp(ef->progtab[i].name + 4, name) == 0) {
1173                         start  = (void **)ef->progtab[i].addr;
1174                         stop = (void **)((char *)ef->progtab[i].addr +
1175                             ef->progtab[i].size);
1176                         count = stop - start;
1177                         if (startp)
1178                                 *startp = start;
1179                         if (stopp)
1180                                 *stopp = stop;
1181                         if (countp)
1182                                 *countp = count;
1183                         return (0);
1184                 }
1185         }
1186         return (ESRCH);
1187 }
1188
1189 static int
1190 link_elf_each_function_name(linker_file_t file,
1191     int (*callback)(const char *, void *), void *opaque)
1192 {
1193         elf_file_t ef = (elf_file_t)file;
1194         const Elf_Sym *symp;
1195         int i, error;
1196
1197         /* Exhaustive search */
1198         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1199                 if (symp->st_value != 0 &&
1200                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1201                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
1202                         if (error)
1203                                 return (error);
1204                 }
1205         }
1206         return (0);
1207 }
1208
1209 static int
1210 link_elf_each_function_nameval(linker_file_t file,
1211     linker_function_nameval_callback_t callback, void *opaque)
1212 {
1213         linker_symval_t symval;
1214         elf_file_t ef = (elf_file_t)file;
1215         const Elf_Sym* symp;
1216         int i, error;
1217
1218         /* Exhaustive search */
1219         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1220                 if (symp->st_value != 0 &&
1221                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1222                         error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1223                         if (error)
1224                                 return (error);
1225                         error = callback(file, i, &symval, opaque);
1226                         if (error)
1227                                 return (error);
1228                 }
1229         }
1230         return (0);
1231 }
1232
1233 static void
1234 elf_obj_cleanup_globals_cache(elf_file_t ef)
1235 {
1236         Elf_Sym *sym;
1237         Elf_Size i;
1238
1239         for (i = 0; i < ef->ddbsymcnt; i++) {
1240                 sym = ef->ddbsymtab + i;
1241                 if (sym->st_shndx == SHN_FBSD_CACHED) {
1242                         sym->st_shndx = SHN_UNDEF;
1243                         sym->st_value = 0;
1244                 }
1245         }
1246 }
1247
1248 /*
1249  * Symbol lookup function that can be used when the symbol index is known (ie
1250  * in relocations). It uses the symbol index instead of doing a fully fledged
1251  * hash table based lookup when such is valid. For example for local symbols.
1252  * This is not only more efficient, it's also more correct. It's not always
1253  * the case that the symbol can be found through the hash table.
1254  */
1255 static int
1256 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1257 {
1258         elf_file_t ef = (elf_file_t)lf;
1259         Elf_Sym *sym;
1260         const char *symbol;
1261         Elf_Addr res1;
1262
1263         /* Don't even try to lookup the symbol if the index is bogus. */
1264         if (symidx >= ef->ddbsymcnt) {
1265                 *res = 0;
1266                 return (EINVAL);
1267         }
1268
1269         sym = ef->ddbsymtab + symidx;
1270
1271         /* Quick answer if there is a definition included. */
1272         if (sym->st_shndx != SHN_UNDEF) {
1273                 *res = sym->st_value;
1274                 return (0);
1275         }
1276
1277         /* If we get here, then it is undefined and needs a lookup. */
1278         switch (ELF_ST_BIND(sym->st_info)) {
1279         case STB_LOCAL:
1280                 /* Local, but undefined? huh? */
1281                 *res = 0;
1282                 return (EINVAL);
1283
1284         case STB_GLOBAL:
1285         case STB_WEAK:
1286                 /* Relative to Data or Function name */
1287                 symbol = ef->ddbstrtab + sym->st_name;
1288
1289                 /* Force a lookup failure if the symbol name is bogus. */
1290                 if (*symbol == 0) {
1291                         *res = 0;
1292                         return (EINVAL);
1293                 }
1294                 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1295
1296                 /*
1297                  * Cache global lookups during module relocation. The failure
1298                  * case is particularly expensive for callers, who must scan
1299                  * through the entire globals table doing strcmp(). Cache to
1300                  * avoid doing such work repeatedly.
1301                  *
1302                  * After relocation is complete, undefined globals will be
1303                  * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1304                  * above.
1305                  */
1306                 if (res1 != 0) {
1307                         sym->st_shndx = SHN_FBSD_CACHED;
1308                         sym->st_value = res1;
1309                         *res = res1;
1310                         return (0);
1311                 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1312                         sym->st_value = 0;
1313                         *res = 0;
1314                         return (0);
1315                 }
1316                 return (EINVAL);
1317
1318         default:
1319                 return (EINVAL);
1320         }
1321 }
1322
1323 static void
1324 link_elf_fix_link_set(elf_file_t ef)
1325 {
1326         static const char startn[] = "__start_";
1327         static const char stopn[] = "__stop_";
1328         Elf_Sym *sym;
1329         const char *sym_name, *linkset_name;
1330         Elf_Addr startp, stopp;
1331         Elf_Size symidx;
1332         int start, i;
1333
1334         startp = stopp = 0;
1335         for (symidx = 1 /* zero entry is special */;
1336                 symidx < ef->ddbsymcnt; symidx++) {
1337                 sym = ef->ddbsymtab + symidx;
1338                 if (sym->st_shndx != SHN_UNDEF)
1339                         continue;
1340
1341                 sym_name = ef->ddbstrtab + sym->st_name;
1342                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1343                         start = 1;
1344                         linkset_name = sym_name + sizeof(startn) - 1;
1345                 }
1346                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1347                         start = 0;
1348                         linkset_name = sym_name + sizeof(stopn) - 1;
1349                 }
1350                 else
1351                         continue;
1352
1353                 for (i = 0; i < ef->nprogtab; i++) {
1354                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1355                                 startp = (Elf_Addr)ef->progtab[i].addr;
1356                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1357                                 break;
1358                         }
1359                 }
1360                 if (i == ef->nprogtab)
1361                         continue;
1362
1363                 sym->st_value = start ? startp : stopp;
1364                 sym->st_shndx = i;
1365         }
1366 }
1367
1368 static void
1369 link_elf_reloc_local(linker_file_t lf)
1370 {
1371         elf_file_t ef = (elf_file_t)lf;
1372         const Elf_Rel *rellim;
1373         const Elf_Rel *rel;
1374         const Elf_Rela *relalim;
1375         const Elf_Rela *rela;
1376         const Elf_Sym *sym;
1377         Elf_Addr base;
1378         int i;
1379         Elf_Size symidx;
1380
1381         link_elf_fix_link_set(ef);
1382
1383         /* Perform relocations without addend if there are any: */
1384         for (i = 0; i < ef->nreltab; i++) {
1385                 rel = ef->reltab[i].rel;
1386                 if (rel == NULL)
1387                         panic("lost a reltab!");
1388                 rellim = rel + ef->reltab[i].nrel;
1389                 base = findbase(ef, ef->reltab[i].sec);
1390                 if (base == 0)
1391                         panic("lost base for reltab");
1392                 for ( ; rel < rellim; rel++) {
1393                         symidx = ELF_R_SYM(rel->r_info);
1394                         if (symidx >= ef->ddbsymcnt)
1395                                 continue;
1396                         sym = ef->ddbsymtab + symidx;
1397                         /* Only do local relocs */
1398                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1399                                 continue;
1400                         elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1401                             elf_obj_lookup);
1402                 }
1403         }
1404
1405         /* Perform relocations with addend if there are any: */
1406         for (i = 0; i < ef->nrelatab; i++) {
1407                 rela = ef->relatab[i].rela;
1408                 if (rela == NULL)
1409                         panic("lost a relatab!");
1410                 relalim = rela + ef->relatab[i].nrela;
1411                 base = findbase(ef, ef->relatab[i].sec);
1412                 if (base == 0)
1413                         panic("lost base for relatab");
1414                 for ( ; rela < relalim; rela++) {
1415                         symidx = ELF_R_SYM(rela->r_info);
1416                         if (symidx >= ef->ddbsymcnt)
1417                                 continue;
1418                         sym = ef->ddbsymtab + symidx;
1419                         /* Only do local relocs */
1420                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1421                                 continue;
1422                         elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1423                             elf_obj_lookup);
1424                 }
1425         }
1426 }
1427
1428 static long
1429 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1430 {
1431     elf_file_t ef = (elf_file_t)lf;
1432
1433     *symtab = ef->ddbsymtab;
1434
1435     if (*symtab == NULL)
1436         return (0);
1437
1438     return (ef->ddbsymcnt);
1439 }
1440
1441 static long
1442 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1443 {
1444     elf_file_t ef = (elf_file_t)lf;
1445
1446     *strtab = ef->ddbstrtab;
1447
1448     if (*strtab == NULL)
1449         return (0);
1450
1451     return (ef->ddbstrcnt);
1452 }