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                         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                         }
 369
 370                         /* Update all symbol values with the offset. */
 371                         for (j = 0; j < ef->ddbsymcnt; j++) {
 372                                 es = &ef->ddbsymtab[j];
 373                                 if (es->st_shndx != i)
 374                                         continue;
 375                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 376                         }
 377                         pb++;
 378                         break;
 379                 case SHT_REL:
 380                         ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
 381                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 382                         ef->reltab[rl].sec = shdr[i].sh_info;
 383                         rl++;
 384                         break;
 385                 case SHT_RELA:
 386                         ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
 387                         ef->relatab[ra].nrela =
 388                             shdr[i].sh_size / sizeof(Elf_Rela);
 389                         ef->relatab[ra].sec = shdr[i].sh_info;
 390                         ra++;
 391                         break;
 392                 }
 393         }
 394         if (pb != ef->nprogtab)
 395                 panic("lost progbits");
 396         if (rl != ef->nreltab)
 397                 panic("lost reltab");
 398         if (ra != ef->nrelatab)
 399                 panic("lost relatab");
 400
 401         /* Local intra-module relocations */
 402         link_elf_reloc_local(lf);
 403
 404         *result = lf;
 405         return (0);
 406
 407 out:
 408         /* preload not done this way */
 409         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 410         return (error);
 411 }
 412
 413 static int
 414 link_elf_link_preload_finish(linker_file_t lf)
 415 {
 416         elf_file_t ef;
 417         int error;
 418
 419         ef = (elf_file_t)lf;
 420         error = relocate_file(ef);
 421         if (error)
 422                 return error;
 423
 424         /* Notify MD code that a module is being loaded. */
 425         error = elf_cpu_load_file(lf);
 426         if (error)
 427                 return (error);
 428
 429         return (0);
 430 }
 431
 432 static int
 433 link_elf_load_file(linker_class_t cls, const char *filename,
 434     linker_file_t *result)
 435 {
 436         struct nameidata nd;
 437         struct thread *td = curthread;  /* XXX */
 438         Elf_Ehdr *hdr;
 439         Elf_Shdr *shdr;
 440         Elf_Sym *es;
 441         int nbytes, i, j;
 442         vm_offset_t mapbase;
 443         size_t mapsize;
 444         int error = 0;
 445         ssize_t resid;
 446         int flags;
 447         elf_file_t ef;
 448         linker_file_t lf;
 449         int symtabindex;
 450         int symstrindex;
 451         int shstrindex;
 452         int nsym;
 453         int pb, rl, ra;
 454         int alignmask;
 455
 456         shdr = NULL;
 457         lf = NULL;
 458         mapsize = 0;
 459         hdr = NULL;
 460
 461         NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
 462         flags = FREAD;
 463         error = vn_open(&nd, &flags, 0, NULL);
 464         if (error)
 465                 return error;
 466         NDFREE(&nd, NDF_ONLY_PNBUF);
 467         if (nd.ni_vp->v_type != VREG) {
 468                 error = ENOEXEC;
 469                 goto out;
 470         }
 471 #ifdef MAC
 472         error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
 473         if (error) {
 474                 goto out;
 475         }
 476 #endif
 477
 478         /* Read the elf header from the file. */
 479         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
 480         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
 481             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 482             &resid, td);
 483         if (error)
 484                 goto out;
 485         if (resid != 0){
 486                 error = ENOEXEC;
 487                 goto out;
 488         }
 489
 490         if (!IS_ELF(*hdr)) {
 491                 error = ENOEXEC;
 492                 goto out;
 493         }
 494
 495         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
 496             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
 497                 link_elf_error(filename, "Unsupported file layout");
 498                 error = ENOEXEC;
 499                 goto out;
 500         }
 501         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
 502             || hdr->e_version != EV_CURRENT) {
 503                 link_elf_error(filename, "Unsupported file version");
 504                 error = ENOEXEC;
 505                 goto out;
 506         }
 507         if (hdr->e_type != ET_REL) {
 508                 error = ENOSYS;
 509                 goto out;
 510         }
 511         if (hdr->e_machine != ELF_TARG_MACH) {
 512                 link_elf_error(filename, "Unsupported machine");
 513                 error = ENOEXEC;
 514                 goto out;
 515         }
 516
 517         lf = linker_make_file(filename, &link_elf_class);
 518         if (!lf) {
 519                 error = ENOMEM;
 520                 goto out;
 521         }
 522         ef = (elf_file_t) lf;
 523         ef->nprogtab = 0;
 524         ef->e_shdr = 0;
 525         ef->nreltab = 0;
 526         ef->nrelatab = 0;
 527
 528         /* Allocate and read in the section header */
 529         nbytes = hdr->e_shnum * hdr->e_shentsize;
 530         if (nbytes == 0 || hdr->e_shoff == 0 ||
 531             hdr->e_shentsize != sizeof(Elf_Shdr)) {
 532                 error = ENOEXEC;
 533                 goto out;
 534         }
 535         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
 536         ef->e_shdr = shdr;
 537         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
 538             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
 539         if (error)
 540                 goto out;
 541         if (resid) {
 542                 error = ENOEXEC;
 543                 goto out;
 544         }
 545
 546         /* Scan the section header for information and table sizing. */
 547         nsym = 0;
 548         symtabindex = -1;
 549         symstrindex = -1;
 550         for (i = 0; i < hdr->e_shnum; i++) {
 551                 if (shdr[i].sh_size == 0)
 552                         continue;
 553                 switch (shdr[i].sh_type) {
 554                 case SHT_PROGBITS:
 555                 case SHT_NOBITS:
 556                         ef->nprogtab++;
 557                         break;
 558                 case SHT_SYMTAB:
 559                         nsym++;
 560                         symtabindex = i;
 561                         symstrindex = shdr[i].sh_link;
 562                         break;
 563                 case SHT_REL:
 564                         ef->nreltab++;
 565                         break;
 566                 case SHT_RELA:
 567                         ef->nrelatab++;
 568                         break;
 569                 case SHT_STRTAB:
 570                         break;
 571                 }
 572         }
 573         if (ef->nprogtab == 0) {
 574                 link_elf_error(filename, "file has no contents");
 575                 error = ENOEXEC;
 576                 goto out;
 577         }
 578         if (nsym != 1) {
 579                 /* Only allow one symbol table for now */
 580                 link_elf_error(filename, "file has no valid symbol table");
 581                 error = ENOEXEC;
 582                 goto out;
 583         }
 584         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
 585             shdr[symstrindex].sh_type != SHT_STRTAB) {
 586                 link_elf_error(filename, "file has invalid symbol strings");
 587                 error = ENOEXEC;
 588                 goto out;
 589         }
 590
 591         /* Allocate space for tracking the load chunks */
 592         if (ef->nprogtab != 0)
 593                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 594                     M_LINKER, M_WAITOK | M_ZERO);
 595         if (ef->nreltab != 0)
 596                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 597                     M_LINKER, M_WAITOK | M_ZERO);
 598         if (ef->nrelatab != 0)
 599                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 600                     M_LINKER, M_WAITOK | M_ZERO);
 601
 602         if (symtabindex == -1)
 603                 panic("lost symbol table index");
 604         /* Allocate space for and load the symbol table */
 605         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 606         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
 607         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
 608             shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
 609             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 610             &resid, td);
 611         if (error)
 612                 goto out;
 613         if (resid != 0){
 614                 error = EINVAL;
 615                 goto out;
 616         }
 617
 618         if (symstrindex == -1)
 619                 panic("lost symbol string index");
 620         /* Allocate space for and load the symbol strings */
 621         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 622         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
 623         error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
 624             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
 625             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 626             &resid, td);
 627         if (error)
 628                 goto out;
 629         if (resid != 0){
 630                 error = EINVAL;
 631                 goto out;
 632         }
 633
 634         /* Do we have a string table for the section names?  */
 635         shstrindex = -1;
 636         if (hdr->e_shstrndx != 0 &&
 637             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
 638                 shstrindex = hdr->e_shstrndx;
 639                 ef->shstrcnt = shdr[shstrindex].sh_size;
 640                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
 641                     M_WAITOK);
 642                 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
 643                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
 644                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 645                     &resid, td);
 646                 if (error)
 647                         goto out;
 648                 if (resid != 0){
 649                         error = EINVAL;
 650                         goto out;
 651                 }
 652         }
 653
 654         /* Size up code/data(progbits) and bss(nobits). */
 655         alignmask = 0;
 656         for (i = 0; i < hdr->e_shnum; i++) {
 657                 if (shdr[i].sh_size == 0)
 658                         continue;
 659                 switch (shdr[i].sh_type) {
 660                 case SHT_PROGBITS:
 661                 case SHT_NOBITS:
 662                         alignmask = shdr[i].sh_addralign - 1;
 663                         mapsize += alignmask;
 664                         mapsize &= ~alignmask;
 665                         mapsize += shdr[i].sh_size;
 666                         break;
 667                 }
 668         }
 669
 670         /*
 671          * We know how much space we need for the text/data/bss/etc.
 672          * This stuff needs to be in a single chunk so that profiling etc
 673          * can get the bounds and gdb can associate offsets with modules
 674          */
 675         ef->object = vm_object_allocate(OBJT_DEFAULT,
 676             round_page(mapsize) >> PAGE_SHIFT);
 677         if (ef->object == NULL) {
 678                 error = ENOMEM;
 679                 goto out;
 680         }
 681         ef->address = (caddr_t) vm_map_min(kernel_map);
 682
 683         /*
 684          * In order to satisfy amd64's architectural requirements on the
 685          * location of code and data in the kernel's address space, request a
 686          * mapping that is above the kernel.
 687          */
 688 #ifdef __amd64__
 689         mapbase = KERNBASE;
 690 #else
 691         mapbase = VM_MIN_KERNEL_ADDRESS;
 692 #endif
 693         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
 694             round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
 695             VM_PROT_ALL, 0);
 696         if (error) {
 697                 vm_object_deallocate(ef->object);
 698                 ef->object = 0;
 699                 goto out;
 700         }
 701
 702         /* Wire the pages */
 703         error = vm_map_wire(kernel_map, mapbase,
 704             mapbase + round_page(mapsize),
 705             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 706         if (error != KERN_SUCCESS) {
 707                 error = ENOMEM;
 708                 goto out;
 709         }
 710
 711         /* Inform the kld system about the situation */
 712         lf->address = ef->address = (caddr_t)mapbase;
 713         lf->size = mapsize;
 714
 715         /*
 716          * Now load code/data(progbits), zero bss(nobits), allocate space for
 717          * and load relocs
 718          */
 719         pb = 0;
 720         rl = 0;
 721         ra = 0;
 722         alignmask = 0;
 723         for (i = 0; i < hdr->e_shnum; i++) {
 724                 if (shdr[i].sh_size == 0)
 725                         continue;
 726                 switch (shdr[i].sh_type) {
 727                 case SHT_PROGBITS:
 728                 case SHT_NOBITS:
 729                         alignmask = shdr[i].sh_addralign - 1;
 730                         mapbase += alignmask;
 731                         mapbase &= ~alignmask;
 732                         if (ef->shstrtab && shdr[i].sh_name != 0)
 733                                 ef->progtab[pb].name =
 734                                     ef->shstrtab + shdr[i].sh_name;
 735                         else if (shdr[i].sh_type == SHT_PROGBITS)
 736                                 ef->progtab[pb].name = "<<PROGBITS>>";
 737                         else
 738                                 ef->progtab[pb].name = "<<NOBITS>>";
 739                         if (ef->progtab[pb].name != NULL &&
 740                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 741                                 ef->progtab[pb].addr =
 742                                     dpcpu_alloc(shdr[i].sh_size);
 743 #ifdef VIMAGE
 744                         else if (ef->progtab[pb].name != NULL &&
 745                             !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 746                                 ef->progtab[pb].addr =
 747                                     vnet_data_alloc(shdr[i].sh_size);
 748 #endif
 749                         else
 750                                 ef->progtab[pb].addr =
 751                                     (void *)(uintptr_t)mapbase;
 752                         if (ef->progtab[pb].addr == NULL) {
 753                                 error = ENOSPC;
 754                                 goto out;
 755                         }
 756                         ef->progtab[pb].size = shdr[i].sh_size;
 757                         ef->progtab[pb].sec = i;
 758                         if (shdr[i].sh_type == SHT_PROGBITS) {
 759                                 error = vn_rdwr(UIO_READ, nd.ni_vp,
 760                                     ef->progtab[pb].addr,
 761                                     shdr[i].sh_size, shdr[i].sh_offset,
 762                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
 763                                     NOCRED, &resid, td);
 764                                 if (error)
 765                                         goto out;
 766                                 if (resid != 0){
 767                                         error = EINVAL;
 768                                         goto out;
 769                                 }
 770                                 /* Initialize the per-cpu or vnet area. */
 771                                 if (ef->progtab[pb].addr != (void *)mapbase &&
 772                                     !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 773                                         dpcpu_copy(ef->progtab[pb].addr,
 774                                             shdr[i].sh_size);
 775 #ifdef VIMAGE
 776                                 else if (ef->progtab[pb].addr !=
 777                                     (void *)mapbase &&
 778                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 779                                         vnet_data_copy(ef->progtab[pb].addr,
 780                                             shdr[i].sh_size);
 781 #endif
 782                         } else
 783                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
 784
 785                         /* Update all symbol values with the offset. */
 786                         for (j = 0; j < ef->ddbsymcnt; j++) {
 787                                 es = &ef->ddbsymtab[j];
 788                                 if (es->st_shndx != i)
 789                                         continue;
 790                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 791                         }
 792                         mapbase += shdr[i].sh_size;
 793                         pb++;
 794                         break;
 795                 case SHT_REL:
 796                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
 797                             M_WAITOK);
 798                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 799                         ef->reltab[rl].sec = shdr[i].sh_info;
 800                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 801                             (void *)ef->reltab[rl].rel,
 802                             shdr[i].sh_size, shdr[i].sh_offset,
 803                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 804                             &resid, td);
 805                         if (error)
 806                                 goto out;
 807                         if (resid != 0){
 808                                 error = EINVAL;
 809                                 goto out;
 810                         }
 811                         rl++;
 812                         break;
 813                 case SHT_RELA:
 814                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
 815                             M_WAITOK);
 816                         ef->relatab[ra].nrela =
 817                             shdr[i].sh_size / sizeof(Elf_Rela);
 818                         ef->relatab[ra].sec = shdr[i].sh_info;
 819                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 820                             (void *)ef->relatab[ra].rela,
 821                             shdr[i].sh_size, shdr[i].sh_offset,
 822                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 823                             &resid, td);
 824                         if (error)
 825                                 goto out;
 826                         if (resid != 0){
 827                                 error = EINVAL;
 828                                 goto out;
 829                         }
 830                         ra++;
 831                         break;
 832                 }
 833         }
 834         if (pb != ef->nprogtab)
 835                 panic("lost progbits");
 836         if (rl != ef->nreltab)
 837                 panic("lost reltab");
 838         if (ra != ef->nrelatab)
 839                 panic("lost relatab");
 840         if (mapbase != (vm_offset_t)ef->address + mapsize)
 841                 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
 842                     (u_long)mapbase, ef->address, (u_long)mapsize,
 843                     (u_long)(vm_offset_t)ef->address + mapsize);
 844
 845         /* Local intra-module relocations */
 846         link_elf_reloc_local(lf);
 847
 848         /* Pull in dependencies */
 849         VOP_UNLOCK(nd.ni_vp, 0);
 850         error = linker_load_dependencies(lf);
 851         vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
 852         if (error)
 853                 goto out;
 854
 855         /* External relocations */
 856         error = relocate_file(ef);
 857         if (error)
 858                 goto out;
 859
 860         /* Notify MD code that a module is being loaded. */
 861         error = elf_cpu_load_file(lf);
 862         if (error)
 863                 goto out;
 864
 865         *result = lf;
 866
 867 out:
 868         VOP_UNLOCK(nd.ni_vp, 0);
 869         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
 870         if (error && lf)
 871                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 872         if (hdr)
 873                 free(hdr, M_LINKER);
 874
 875         return error;
 876 }
 877
 878 static void
 879 link_elf_unload_file(linker_file_t file)
 880 {
 881         elf_file_t ef = (elf_file_t) file;
 882         int i;
 883
 884         /* Notify MD code that a module is being unloaded. */
 885         elf_cpu_unload_file(file);
 886
 887         if (ef->progtab) {
 888                 for (i = 0; i < ef->nprogtab; i++) {
 889                         if (ef->progtab[i].size == 0)
 890                                 continue;
 891                         if (ef->progtab[i].name == NULL)
 892                                 continue;
 893                         if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
 894                                 dpcpu_free(ef->progtab[i].addr,
 895                                     ef->progtab[i].size);
 896 #ifdef VIMAGE
 897                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
 898                                 vnet_data_free(ef->progtab[i].addr,
 899                                     ef->progtab[i].size);
 900 #endif
 901                 }
 902         }
 903         if (ef->preloaded) {
 904                 if (ef->reltab)
 905                         free(ef->reltab, M_LINKER);
 906                 if (ef->relatab)
 907                         free(ef->relatab, M_LINKER);
 908                 if (ef->progtab)
 909                         free(ef->progtab, M_LINKER);
 910                 if (ef->ctftab)
 911                         free(ef->ctftab, M_LINKER);
 912                 if (ef->ctfoff)
 913                         free(ef->ctfoff, M_LINKER);
 914                 if (ef->typoff)
 915                         free(ef->typoff, M_LINKER);
 916                 if (file->filename != NULL)
 917                         preload_delete_name(file->filename);
 918                 /* XXX reclaim module memory? */
 919                 return;
 920         }
 921
 922         for (i = 0; i < ef->nreltab; i++)
 923                 if (ef->reltab[i].rel)
 924                         free(ef->reltab[i].rel, M_LINKER);
 925         for (i = 0; i < ef->nrelatab; i++)
 926                 if (ef->relatab[i].rela)
 927                         free(ef->relatab[i].rela, M_LINKER);
 928         if (ef->reltab)
 929                 free(ef->reltab, M_LINKER);
 930         if (ef->relatab)
 931                 free(ef->relatab, M_LINKER);
 932         if (ef->progtab)
 933                 free(ef->progtab, M_LINKER);
 934
 935         if (ef->object) {
 936                 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
 937                     (vm_offset_t) ef->address +
 938                     (ef->object->size << PAGE_SHIFT));
 939         }
 940         if (ef->e_shdr)
 941                 free(ef->e_shdr, M_LINKER);
 942         if (ef->ddbsymtab)
 943                 free(ef->ddbsymtab, M_LINKER);
 944         if (ef->ddbstrtab)
 945                 free(ef->ddbstrtab, M_LINKER);
 946         if (ef->shstrtab)
 947                 free(ef->shstrtab, M_LINKER);
 948         if (ef->ctftab)
 949                 free(ef->ctftab, M_LINKER);
 950         if (ef->ctfoff)
 951                 free(ef->ctfoff, M_LINKER);
 952         if (ef->typoff)
 953                 free(ef->typoff, M_LINKER);
 954 }
 955
 956 static const char *
 957 symbol_name(elf_file_t ef, Elf_Size r_info)
 958 {
 959         const Elf_Sym *ref;
 960
 961         if (ELF_R_SYM(r_info)) {
 962                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
 963                 return ef->ddbstrtab + ref->st_name;
 964         } else
 965                 return NULL;
 966 }
 967
 968 static Elf_Addr
 969 findbase(elf_file_t ef, int sec)
 970 {
 971         int i;
 972         Elf_Addr base = 0;
 973
 974         for (i = 0; i < ef->nprogtab; i++) {
 975                 if (sec == ef->progtab[i].sec) {
 976                         base = (Elf_Addr)ef->progtab[i].addr;
 977                         break;
 978                 }
 979         }
 980         return base;
 981 }
 982
 983 static int
 984 relocate_file(elf_file_t ef)
 985 {
 986         const Elf_Rel *rellim;
 987         const Elf_Rel *rel;
 988         const Elf_Rela *relalim;
 989         const Elf_Rela *rela;
 990         const char *symname;
 991         const Elf_Sym *sym;
 992         int i;
 993         Elf_Size symidx;
 994         Elf_Addr base;
 995
 996
 997         /* Perform relocations without addend if there are any: */
 998         for (i = 0; i < ef->nreltab; i++) {
 999                 rel = ef->reltab[i].rel;
1000                 if (rel == NULL)
1001                         panic("lost a reltab!");
1002                 rellim = rel + ef->reltab[i].nrel;
1003                 base = findbase(ef, ef->reltab[i].sec);
1004                 if (base == 0)
1005                         panic("lost base for reltab");
1006                 for ( ; rel < rellim; rel++) {
1007                         symidx = ELF_R_SYM(rel->r_info);
1008                         if (symidx >= ef->ddbsymcnt)
1009                                 continue;
1010                         sym = ef->ddbsymtab + symidx;
1011                         /* Local relocs are already done */
1012                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1013                                 continue;
1014                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1015                             elf_obj_lookup)) {
1016                                 symname = symbol_name(ef, rel->r_info);
1017                                 printf("link_elf_obj: symbol %s undefined\n",
1018                                     symname);
1019                                 return ENOENT;
1020                         }
1021                 }
1022         }
1023
1024         /* Perform relocations with addend if there are any: */
1025         for (i = 0; i < ef->nrelatab; i++) {
1026                 rela = ef->relatab[i].rela;
1027                 if (rela == NULL)
1028                         panic("lost a relatab!");
1029                 relalim = rela + ef->relatab[i].nrela;
1030                 base = findbase(ef, ef->relatab[i].sec);
1031                 if (base == 0)
1032                         panic("lost base for relatab");
1033                 for ( ; rela < relalim; rela++) {
1034                         symidx = ELF_R_SYM(rela->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, rela, ELF_RELOC_RELA,
1042                             elf_obj_lookup)) {
1043                                 symname = symbol_name(ef, rela->r_info);
1044                                 printf("link_elf_obj: symbol %s undefined\n",
1045                                     symname);
1046                                 return ENOENT;
1047                         }
1048                 }
1049         }
1050
1051         /*
1052          * Only clean SHN_FBSD_CACHED for successfull return.  If we
1053          * modified symbol table for the object but found an
1054          * unresolved symbol, there is no reason to roll back.
1055          */
1056         elf_obj_cleanup_globals_cache(ef);
1057
1058         return 0;
1059 }
1060
1061 static int
1062 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1063 {
1064         elf_file_t ef = (elf_file_t) lf;
1065         const Elf_Sym *symp;
1066         const char *strp;
1067         int i;
1068
1069         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1070                 strp = ef->ddbstrtab + symp->st_name;
1071                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1072                         *sym = (c_linker_sym_t) symp;
1073                         return 0;
1074                 }
1075         }
1076         return ENOENT;
1077 }
1078
1079 static int
1080 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1081     linker_symval_t *symval)
1082 {
1083         elf_file_t ef = (elf_file_t) lf;
1084         const Elf_Sym *es = (const Elf_Sym*) sym;
1085
1086         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1087                 symval->name = ef->ddbstrtab + es->st_name;
1088                 symval->value = (caddr_t)es->st_value;
1089                 symval->size = es->st_size;
1090                 return 0;
1091         }
1092         return ENOENT;
1093 }
1094
1095 static int
1096 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1097     c_linker_sym_t *sym, long *diffp)
1098 {
1099         elf_file_t ef = (elf_file_t) lf;
1100         u_long off = (uintptr_t) (void *) value;
1101         u_long diff = off;
1102         u_long st_value;
1103         const Elf_Sym *es;
1104         const Elf_Sym *best = 0;
1105         int i;
1106
1107         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1108                 if (es->st_name == 0)
1109                         continue;
1110                 st_value = es->st_value;
1111                 if (off >= st_value) {
1112                         if (off - st_value < diff) {
1113                                 diff = off - st_value;
1114                                 best = es;
1115                                 if (diff == 0)
1116                                         break;
1117                         } else if (off - st_value == diff) {
1118                                 best = es;
1119                         }
1120                 }
1121         }
1122         if (best == 0)
1123                 *diffp = off;
1124         else
1125                 *diffp = diff;
1126         *sym = (c_linker_sym_t) best;
1127
1128         return 0;
1129 }
1130
1131 /*
1132  * Look up a linker set on an ELF system.
1133  */
1134 static int
1135 link_elf_lookup_set(linker_file_t lf, const char *name,
1136     void ***startp, void ***stopp, int *countp)
1137 {
1138         elf_file_t ef = (elf_file_t)lf;
1139         void **start, **stop;
1140         int i, count;
1141
1142         /* Relative to section number */
1143         for (i = 0; i < ef->nprogtab; i++) {
1144                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1145                     strcmp(ef->progtab[i].name + 4, name) == 0) {
1146                         start  = (void **)ef->progtab[i].addr;
1147                         stop = (void **)((char *)ef->progtab[i].addr +
1148                             ef->progtab[i].size);
1149                         count = stop - start;
1150                         if (startp)
1151                                 *startp = start;
1152                         if (stopp)
1153                                 *stopp = stop;
1154                         if (countp)
1155                                 *countp = count;
1156                         return (0);
1157                 }
1158         }
1159         return (ESRCH);
1160 }
1161
1162 static int
1163 link_elf_each_function_name(linker_file_t file,
1164     int (*callback)(const char *, void *), void *opaque)
1165 {
1166         elf_file_t ef = (elf_file_t)file;
1167         const Elf_Sym *symp;
1168         int i, error;
1169
1170         /* Exhaustive search */
1171         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1172                 if (symp->st_value != 0 &&
1173                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1174                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
1175                         if (error)
1176                                 return (error);
1177                 }
1178         }
1179         return (0);
1180 }
1181
1182 static int
1183 link_elf_each_function_nameval(linker_file_t file,
1184     linker_function_nameval_callback_t callback, void *opaque)
1185 {
1186         linker_symval_t symval;
1187         elf_file_t ef = (elf_file_t)file;
1188         const Elf_Sym* symp;
1189         int i, error;
1190
1191         /* Exhaustive search */
1192         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1193                 if (symp->st_value != 0 &&
1194                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1195                         error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1196                         if (error)
1197                                 return (error);
1198                         error = callback(file, i, &symval, opaque);
1199                         if (error)
1200                                 return (error);
1201                 }
1202         }
1203         return (0);
1204 }
1205
1206 static void
1207 elf_obj_cleanup_globals_cache(elf_file_t ef)
1208 {
1209         Elf_Sym *sym;
1210         Elf_Size i;
1211
1212         for (i = 0; i < ef->ddbsymcnt; i++) {
1213                 sym = ef->ddbsymtab + i;
1214                 if (sym->st_shndx == SHN_FBSD_CACHED) {
1215                         sym->st_shndx = SHN_UNDEF;
1216                         sym->st_value = 0;
1217                 }
1218         }
1219 }
1220
1221 /*
1222  * Symbol lookup function that can be used when the symbol index is known (ie
1223  * in relocations). It uses the symbol index instead of doing a fully fledged
1224  * hash table based lookup when such is valid. For example for local symbols.
1225  * This is not only more efficient, it's also more correct. It's not always
1226  * the case that the symbol can be found through the hash table.
1227  */
1228 static int
1229 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1230 {
1231         elf_file_t ef = (elf_file_t)lf;
1232         Elf_Sym *sym;
1233         const char *symbol;
1234         Elf_Addr res1;
1235
1236         /* Don't even try to lookup the symbol if the index is bogus. */
1237         if (symidx >= ef->ddbsymcnt) {
1238                 *res = 0;
1239                 return (EINVAL);
1240         }
1241
1242         sym = ef->ddbsymtab + symidx;
1243
1244         /* Quick answer if there is a definition included. */
1245         if (sym->st_shndx != SHN_UNDEF) {
1246                 *res = sym->st_value;
1247                 return (0);
1248         }
1249
1250         /* If we get here, then it is undefined and needs a lookup. */
1251         switch (ELF_ST_BIND(sym->st_info)) {
1252         case STB_LOCAL:
1253                 /* Local, but undefined? huh? */
1254                 *res = 0;
1255                 return (EINVAL);
1256
1257         case STB_GLOBAL:
1258         case STB_WEAK:
1259                 /* Relative to Data or Function name */
1260                 symbol = ef->ddbstrtab + sym->st_name;
1261
1262                 /* Force a lookup failure if the symbol name is bogus. */
1263                 if (*symbol == 0) {
1264                         *res = 0;
1265                         return (EINVAL);
1266                 }
1267                 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1268
1269                 /*
1270                  * Cache global lookups during module relocation. The failure
1271                  * case is particularly expensive for callers, who must scan
1272                  * through the entire globals table doing strcmp(). Cache to
1273                  * avoid doing such work repeatedly.
1274                  *
1275                  * After relocation is complete, undefined globals will be
1276                  * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1277                  * above.
1278                  */
1279                 if (res1 != 0) {
1280                         sym->st_shndx = SHN_FBSD_CACHED;
1281                         sym->st_value = res1;
1282                         *res = res1;
1283                         return (0);
1284                 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1285                         sym->st_value = 0;
1286                         *res = 0;
1287                         return (0);
1288                 }
1289                 return (EINVAL);
1290
1291         default:
1292                 return (EINVAL);
1293         }
1294 }
1295
1296 static void
1297 link_elf_fix_link_set(elf_file_t ef)
1298 {
1299         static const char startn[] = "__start_";
1300         static const char stopn[] = "__stop_";
1301         Elf_Sym *sym;
1302         const char *sym_name, *linkset_name;
1303         Elf_Addr startp, stopp;
1304         Elf_Size symidx;
1305         int start, i;
1306
1307         startp = stopp = 0;
1308         for (symidx = 1 /* zero entry is special */;
1309                 symidx < ef->ddbsymcnt; symidx++) {
1310                 sym = ef->ddbsymtab + symidx;
1311                 if (sym->st_shndx != SHN_UNDEF)
1312                         continue;
1313
1314                 sym_name = ef->ddbstrtab + sym->st_name;
1315                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1316                         start = 1;
1317                         linkset_name = sym_name + sizeof(startn) - 1;
1318                 }
1319                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1320                         start = 0;
1321                         linkset_name = sym_name + sizeof(stopn) - 1;
1322                 }
1323                 else
1324                         continue;
1325
1326                 for (i = 0; i < ef->nprogtab; i++) {
1327                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1328                                 startp = (Elf_Addr)ef->progtab[i].addr;
1329                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1330                                 break;
1331                         }
1332                 }
1333                 if (i == ef->nprogtab)
1334                         continue;
1335
1336                 sym->st_value = start ? startp : stopp;
1337                 sym->st_shndx = i;
1338         }
1339 }
1340
1341 static void
1342 link_elf_reloc_local(linker_file_t lf)
1343 {
1344         elf_file_t ef = (elf_file_t)lf;
1345         const Elf_Rel *rellim;
1346         const Elf_Rel *rel;
1347         const Elf_Rela *relalim;
1348         const Elf_Rela *rela;
1349         const Elf_Sym *sym;
1350         Elf_Addr base;
1351         int i;
1352         Elf_Size symidx;
1353
1354         link_elf_fix_link_set(ef);
1355
1356         /* Perform relocations without addend if there are any: */
1357         for (i = 0; i < ef->nreltab; i++) {
1358                 rel = ef->reltab[i].rel;
1359                 if (rel == NULL)
1360                         panic("lost a reltab!");
1361                 rellim = rel + ef->reltab[i].nrel;
1362                 base = findbase(ef, ef->reltab[i].sec);
1363                 if (base == 0)
1364                         panic("lost base for reltab");
1365                 for ( ; rel < rellim; rel++) {
1366                         symidx = ELF_R_SYM(rel->r_info);
1367                         if (symidx >= ef->ddbsymcnt)
1368                                 continue;
1369                         sym = ef->ddbsymtab + symidx;
1370                         /* Only do local relocs */
1371                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1372                                 continue;
1373                         elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1374                             elf_obj_lookup);
1375                 }
1376         }
1377
1378         /* Perform relocations with addend if there are any: */
1379         for (i = 0; i < ef->nrelatab; i++) {
1380                 rela = ef->relatab[i].rela;
1381                 if (rela == NULL)
1382                         panic("lost a relatab!");
1383                 relalim = rela + ef->relatab[i].nrela;
1384                 base = findbase(ef, ef->relatab[i].sec);
1385                 if (base == 0)
1386                         panic("lost base for relatab");
1387                 for ( ; rela < relalim; rela++) {
1388                         symidx = ELF_R_SYM(rela->r_info);
1389                         if (symidx >= ef->ddbsymcnt)
1390                                 continue;
1391                         sym = ef->ddbsymtab + symidx;
1392                         /* Only do local relocs */
1393                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1394                                 continue;
1395                         elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1396                             elf_obj_lookup);
1397                 }
1398         }
1399 }
1400
1401 static long
1402 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1403 {
1404     elf_file_t ef = (elf_file_t)lf;
1405
1406     *symtab = ef->ddbsymtab;
1407
1408     if (*symtab == NULL)
1409         return (0);
1410
1411     return (ef->ddbsymcnt);
1412 }
1413
1414 static long
1415 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1416 {
1417     elf_file_t ef = (elf_file_t)lf;
1418
1419     *strtab = ef->ddbstrtab;
1420
1421     if (*strtab == NULL)
1422         return (0);
1423
1424     return (ef->ddbstrcnt);
1425 }