sys/kern/link_elf_obj.c

   1 /*-
   2  * Copyright (c) 1998-2000 Doug Rabson
   3  * Copyright (c) 2004 Peter Wemm
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27
  28 #include <sys/cdefs.h>
  29 __FBSDID("$FreeBSD$");
  30
  31 #include "opt_ddb.h"
  32
  33 #include <sys/param.h>
  34 #include <sys/systm.h>
  35 #include <sys/kernel.h>
  36 #include <sys/lock.h>
  37 #include <sys/malloc.h>
  38 #include <sys/mutex.h>
  39 #include <sys/mount.h>
  40 #include <sys/proc.h>
  41 #include <sys/namei.h>
  42 #include <sys/fcntl.h>
  43 #include <sys/vnode.h>
  44 #include <sys/linker.h>
  45
  46 #include <machine/elf.h>
  47
  48 #include <net/vnet.h>
  49
  50 #include <security/mac/mac_framework.h>
  51
  52 #include <vm/vm.h>
  53 #include <vm/vm_param.h>
  54 #include <vm/vm_object.h>
  55 #include <vm/vm_kern.h>
  56 #include <vm/vm_extern.h>
  57 #include <vm/pmap.h>
  58 #include <vm/vm_map.h>
  59
  60 #include <sys/link_elf.h>
  61
  62 #ifdef DDB_CTF
  63 #include <sys/zlib.h>
  64 #endif
  65
  66 #include "linker_if.h"
  67
  68 typedef struct {
  69         void            *addr;
  70         Elf_Off         size;
  71         int             flags;
  72         int             sec;    /* Original section */
  73         char            *name;
  74 } Elf_progent;
  75
  76 typedef struct {
  77         Elf_Rel         *rel;
  78         int             nrel;
  79         int             sec;
  80 } Elf_relent;
  81
  82 typedef struct {
  83         Elf_Rela        *rela;
  84         int             nrela;
  85         int             sec;
  86 } Elf_relaent;
  87
  88
  89 typedef struct elf_file {
  90         struct linker_file lf;          /* Common fields */
  91
  92         int             preloaded;
  93         caddr_t         address;        /* Relocation address */
  94         vm_object_t     object;         /* VM object to hold file pages */
  95         Elf_Shdr        *e_shdr;
  96
  97         Elf_progent     *progtab;
  98         int             nprogtab;
  99
 100         Elf_relaent     *relatab;
 101         int             nrelatab;
 102
 103         Elf_relent      *reltab;
 104         int             nreltab;
 105
 106         Elf_Sym         *ddbsymtab;     /* The symbol table we are using */
 107         long            ddbsymcnt;      /* Number of symbols */
 108         caddr_t         ddbstrtab;      /* String table */
 109         long            ddbstrcnt;      /* number of bytes in string table */
 110
 111         caddr_t         shstrtab;       /* Section name string table */
 112         long            shstrcnt;       /* number of bytes in string table */
 113
 114         caddr_t         ctftab;         /* CTF table */
 115         long            ctfcnt;         /* number of bytes in CTF table */
 116         caddr_t         ctfoff;         /* CTF offset table */
 117         caddr_t         typoff;         /* Type offset table */
 118         long            typlen;         /* Number of type entries. */
 119
 120 } *elf_file_t;
 121
 122 #include <kern/kern_ctf.c>
 123
 124 static int      link_elf_link_preload(linker_class_t cls,
 125                     const char *, linker_file_t *);
 126 static int      link_elf_link_preload_finish(linker_file_t);
 127 static int      link_elf_load_file(linker_class_t, const char *, linker_file_t *);
 128 static int      link_elf_lookup_symbol(linker_file_t, const char *,
 129                     c_linker_sym_t *);
 130 static int      link_elf_symbol_values(linker_file_t, c_linker_sym_t,
 131                     linker_symval_t *);
 132 static int      link_elf_search_symbol(linker_file_t, caddr_t value,
 133                     c_linker_sym_t *sym, long *diffp);
 134
 135 static void     link_elf_unload_file(linker_file_t);
 136 static int      link_elf_lookup_set(linker_file_t, const char *,
 137                     void ***, void ***, int *);
 138 static int      link_elf_each_function_name(linker_file_t,
 139                     int (*)(const char *, void *), void *);
 140 static int      link_elf_each_function_nameval(linker_file_t,
 141                                 linker_function_nameval_callback_t,
 142                                 void *);
 143 static int      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_X86_64_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_X86_64_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_X86_64_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                         } else if (ef->progtab[pb].name != NULL &&
 379                             !strcmp(ef->progtab[pb].name, ".ctors")) {
 380                                 lf->ctors_addr = ef->progtab[pb].addr;
 381                                 lf->ctors_size = shdr[i].sh_size;
 382                         }
 383
 384                         /* Update all symbol values with the offset. */
 385                         for (j = 0; j < ef->ddbsymcnt; j++) {
 386                                 es = &ef->ddbsymtab[j];
 387                                 if (es->st_shndx != i)
 388                                         continue;
 389                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 390                         }
 391                         pb++;
 392                         break;
 393                 case SHT_REL:
 394                         ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
 395                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 396                         ef->reltab[rl].sec = shdr[i].sh_info;
 397                         rl++;
 398                         break;
 399                 case SHT_RELA:
 400                         ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
 401                         ef->relatab[ra].nrela =
 402                             shdr[i].sh_size / sizeof(Elf_Rela);
 403                         ef->relatab[ra].sec = shdr[i].sh_info;
 404                         ra++;
 405                         break;
 406                 }
 407         }
 408         if (pb != ef->nprogtab) {
 409                 printf("%s: lost progbits\n", filename);
 410                 error = ENOEXEC;
 411                 goto out;
 412         }
 413         if (rl != ef->nreltab) {
 414                 printf("%s: lost reltab\n", filename);
 415                 error = ENOEXEC;
 416                 goto out;
 417         }
 418         if (ra != ef->nrelatab) {
 419                 printf("%s: lost relatab\n", filename);
 420                 error = ENOEXEC;
 421                 goto out;
 422         }
 423
 424         /* Local intra-module relocations */
 425         error = link_elf_reloc_local(lf);
 426         if (error != 0)
 427                 goto out;
 428
 429         *result = lf;
 430         return (0);
 431
 432 out:
 433         /* preload not done this way */
 434         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 435         return (error);
 436 }
 437
 438 static void
 439 link_elf_invoke_ctors(caddr_t addr, size_t size)
 440 {
 441         void (**ctor)(void);
 442         size_t i, cnt;
 443
 444         if (addr == NULL || size == 0)
 445                 return;
 446         cnt = size / sizeof(*ctor);
 447         ctor = (void *)addr;
 448         for (i = 0; i < cnt; i++) {
 449                 if (ctor[i] != NULL)
 450                         (*ctor[i])();
 451         }
 452 }
 453
 454 static int
 455 link_elf_link_preload_finish(linker_file_t lf)
 456 {
 457         elf_file_t ef;
 458         int error;
 459
 460         ef = (elf_file_t)lf;
 461         error = relocate_file(ef);
 462         if (error)
 463                 return error;
 464
 465         /* Notify MD code that a module is being loaded. */
 466         error = elf_cpu_load_file(lf);
 467         if (error)
 468                 return (error);
 469
 470         /* Invoke .ctors */
 471         link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
 472         return (0);
 473 }
 474
 475 static int
 476 link_elf_load_file(linker_class_t cls, const char *filename,
 477     linker_file_t *result)
 478 {
 479         struct nameidata nd;
 480         struct thread *td = curthread;  /* XXX */
 481         Elf_Ehdr *hdr;
 482         Elf_Shdr *shdr;
 483         Elf_Sym *es;
 484         int nbytes, i, j;
 485         vm_offset_t mapbase;
 486         size_t mapsize;
 487         int error = 0;
 488         ssize_t resid;
 489         int flags;
 490         elf_file_t ef;
 491         linker_file_t lf;
 492         int symtabindex;
 493         int symstrindex;
 494         int shstrindex;
 495         int nsym;
 496         int pb, rl, ra;
 497         int alignmask;
 498
 499         shdr = NULL;
 500         lf = NULL;
 501         mapsize = 0;
 502         hdr = NULL;
 503
 504         NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
 505         flags = FREAD;
 506         error = vn_open(&nd, &flags, 0, NULL);
 507         if (error)
 508                 return error;
 509         NDFREE(&nd, NDF_ONLY_PNBUF);
 510         if (nd.ni_vp->v_type != VREG) {
 511                 error = ENOEXEC;
 512                 goto out;
 513         }
 514 #ifdef MAC
 515         error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
 516         if (error) {
 517                 goto out;
 518         }
 519 #endif
 520
 521         /* Read the elf header from the file. */
 522         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
 523         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
 524             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 525             &resid, td);
 526         if (error)
 527                 goto out;
 528         if (resid != 0){
 529                 error = ENOEXEC;
 530                 goto out;
 531         }
 532
 533         if (!IS_ELF(*hdr)) {
 534                 error = ENOEXEC;
 535                 goto out;
 536         }
 537
 538         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
 539             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
 540                 link_elf_error(filename, "Unsupported file layout");
 541                 error = ENOEXEC;
 542                 goto out;
 543         }
 544         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
 545             || hdr->e_version != EV_CURRENT) {
 546                 link_elf_error(filename, "Unsupported file version");
 547                 error = ENOEXEC;
 548                 goto out;
 549         }
 550         if (hdr->e_type != ET_REL) {
 551                 error = ENOSYS;
 552                 goto out;
 553         }
 554         if (hdr->e_machine != ELF_TARG_MACH) {
 555                 link_elf_error(filename, "Unsupported machine");
 556                 error = ENOEXEC;
 557                 goto out;
 558         }
 559
 560         lf = linker_make_file(filename, &link_elf_class);
 561         if (!lf) {
 562                 error = ENOMEM;
 563                 goto out;
 564         }
 565         ef = (elf_file_t) lf;
 566         ef->nprogtab = 0;
 567         ef->e_shdr = 0;
 568         ef->nreltab = 0;
 569         ef->nrelatab = 0;
 570
 571         /* Allocate and read in the section header */
 572         nbytes = hdr->e_shnum * hdr->e_shentsize;
 573         if (nbytes == 0 || hdr->e_shoff == 0 ||
 574             hdr->e_shentsize != sizeof(Elf_Shdr)) {
 575                 error = ENOEXEC;
 576                 goto out;
 577         }
 578         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
 579         ef->e_shdr = shdr;
 580         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
 581             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
 582         if (error)
 583                 goto out;
 584         if (resid) {
 585                 error = ENOEXEC;
 586                 goto out;
 587         }
 588
 589         /* Scan the section header for information and table sizing. */
 590         nsym = 0;
 591         symtabindex = -1;
 592         symstrindex = -1;
 593         for (i = 0; i < hdr->e_shnum; i++) {
 594                 if (shdr[i].sh_size == 0)
 595                         continue;
 596                 switch (shdr[i].sh_type) {
 597                 case SHT_PROGBITS:
 598                 case SHT_NOBITS:
 599 #ifdef __amd64__
 600                 case SHT_X86_64_UNWIND:
 601 #endif
 602                         ef->nprogtab++;
 603                         break;
 604                 case SHT_SYMTAB:
 605                         nsym++;
 606                         symtabindex = i;
 607                         symstrindex = shdr[i].sh_link;
 608                         break;
 609                 case SHT_REL:
 610                         ef->nreltab++;
 611                         break;
 612                 case SHT_RELA:
 613                         ef->nrelatab++;
 614                         break;
 615                 case SHT_STRTAB:
 616                         break;
 617                 }
 618         }
 619         if (ef->nprogtab == 0) {
 620                 link_elf_error(filename, "file has no contents");
 621                 error = ENOEXEC;
 622                 goto out;
 623         }
 624         if (nsym != 1) {
 625                 /* Only allow one symbol table for now */
 626                 link_elf_error(filename, "file has no valid symbol table");
 627                 error = ENOEXEC;
 628                 goto out;
 629         }
 630         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
 631             shdr[symstrindex].sh_type != SHT_STRTAB) {
 632                 link_elf_error(filename, "file has invalid symbol strings");
 633                 error = ENOEXEC;
 634                 goto out;
 635         }
 636
 637         /* Allocate space for tracking the load chunks */
 638         if (ef->nprogtab != 0)
 639                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 640                     M_LINKER, M_WAITOK | M_ZERO);
 641         if (ef->nreltab != 0)
 642                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 643                     M_LINKER, M_WAITOK | M_ZERO);
 644         if (ef->nrelatab != 0)
 645                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 646                     M_LINKER, M_WAITOK | M_ZERO);
 647
 648         if (symtabindex == -1) {
 649                 link_elf_error(filename, "lost symbol table index");
 650                 error = ENOEXEC;
 651                 goto out;
 652         }
 653         /* Allocate space for and load the symbol table */
 654         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 655         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
 656         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
 657             shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
 658             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 659             &resid, td);
 660         if (error)
 661                 goto out;
 662         if (resid != 0){
 663                 error = EINVAL;
 664                 goto out;
 665         }
 666
 667         if (symstrindex == -1) {
 668                 link_elf_error(filename, "lost symbol string index");
 669                 error = ENOEXEC;
 670                 goto out;
 671         }
 672         /* Allocate space for and load the symbol strings */
 673         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 674         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
 675         error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
 676             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
 677             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 678             &resid, td);
 679         if (error)
 680                 goto out;
 681         if (resid != 0){
 682                 error = EINVAL;
 683                 goto out;
 684         }
 685
 686         /* Do we have a string table for the section names?  */
 687         shstrindex = -1;
 688         if (hdr->e_shstrndx != 0 &&
 689             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
 690                 shstrindex = hdr->e_shstrndx;
 691                 ef->shstrcnt = shdr[shstrindex].sh_size;
 692                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
 693                     M_WAITOK);
 694                 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
 695                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
 696                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 697                     &resid, td);
 698                 if (error)
 699                         goto out;
 700                 if (resid != 0){
 701                         error = EINVAL;
 702                         goto out;
 703                 }
 704         }
 705
 706         /* Size up code/data(progbits) and bss(nobits). */
 707         alignmask = 0;
 708         for (i = 0; i < hdr->e_shnum; i++) {
 709                 if (shdr[i].sh_size == 0)
 710                         continue;
 711                 switch (shdr[i].sh_type) {
 712                 case SHT_PROGBITS:
 713                 case SHT_NOBITS:
 714 #ifdef __amd64__
 715                 case SHT_X86_64_UNWIND:
 716 #endif
 717                         alignmask = shdr[i].sh_addralign - 1;
 718                         mapsize += alignmask;
 719                         mapsize &= ~alignmask;
 720                         mapsize += shdr[i].sh_size;
 721                         break;
 722                 }
 723         }
 724
 725         /*
 726          * We know how much space we need for the text/data/bss/etc.
 727          * This stuff needs to be in a single chunk so that profiling etc
 728          * can get the bounds and gdb can associate offsets with modules
 729          */
 730         ef->object = vm_object_allocate(OBJT_DEFAULT,
 731             round_page(mapsize) >> PAGE_SHIFT);
 732         if (ef->object == NULL) {
 733                 error = ENOMEM;
 734                 goto out;
 735         }
 736         ef->address = (caddr_t) vm_map_min(kernel_map);
 737
 738         /*
 739          * In order to satisfy amd64's architectural requirements on the
 740          * location of code and data in the kernel's address space, request a
 741          * mapping that is above the kernel.
 742          */
 743 #ifdef __amd64__
 744         mapbase = KERNBASE;
 745 #else
 746         mapbase = VM_MIN_KERNEL_ADDRESS;
 747 #endif
 748         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
 749             round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
 750             VM_PROT_ALL, 0);
 751         if (error) {
 752                 vm_object_deallocate(ef->object);
 753                 ef->object = 0;
 754                 goto out;
 755         }
 756
 757         /* Wire the pages */
 758         error = vm_map_wire(kernel_map, mapbase,
 759             mapbase + round_page(mapsize),
 760             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 761         if (error != KERN_SUCCESS) {
 762                 error = ENOMEM;
 763                 goto out;
 764         }
 765
 766         /* Inform the kld system about the situation */
 767         lf->address = ef->address = (caddr_t)mapbase;
 768         lf->size = mapsize;
 769
 770         /*
 771          * Now load code/data(progbits), zero bss(nobits), allocate space for
 772          * and load relocs
 773          */
 774         pb = 0;
 775         rl = 0;
 776         ra = 0;
 777         alignmask = 0;
 778         for (i = 0; i < hdr->e_shnum; i++) {
 779                 if (shdr[i].sh_size == 0)
 780                         continue;
 781                 switch (shdr[i].sh_type) {
 782                 case SHT_PROGBITS:
 783                 case SHT_NOBITS:
 784 #ifdef __amd64__
 785                 case SHT_X86_64_UNWIND:
 786 #endif
 787                         alignmask = shdr[i].sh_addralign - 1;
 788                         mapbase += alignmask;
 789                         mapbase &= ~alignmask;
 790                         if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
 791                                 ef->progtab[pb].name =
 792                                     ef->shstrtab + shdr[i].sh_name;
 793                                 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
 794                                         lf->ctors_addr = (caddr_t)mapbase;
 795                                         lf->ctors_size = shdr[i].sh_size;
 796                                 }
 797                         } else if (shdr[i].sh_type == SHT_PROGBITS)
 798                                 ef->progtab[pb].name = "<<PROGBITS>>";
 799 #ifdef __amd64__
 800                         else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
 801                                 ef->progtab[pb].name = "<<UNWIND>>";
 802 #endif
 803                         else
 804                                 ef->progtab[pb].name = "<<NOBITS>>";
 805                         if (ef->progtab[pb].name != NULL &&
 806                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 807                                 ef->progtab[pb].addr =
 808                                     dpcpu_alloc(shdr[i].sh_size);
 809 #ifdef VIMAGE
 810                         else if (ef->progtab[pb].name != NULL &&
 811                             !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 812                                 ef->progtab[pb].addr =
 813                                     vnet_data_alloc(shdr[i].sh_size);
 814 #endif
 815                         else
 816                                 ef->progtab[pb].addr =
 817                                     (void *)(uintptr_t)mapbase;
 818                         if (ef->progtab[pb].addr == NULL) {
 819                                 error = ENOSPC;
 820                                 goto out;
 821                         }
 822                         ef->progtab[pb].size = shdr[i].sh_size;
 823                         ef->progtab[pb].sec = i;
 824                         if (shdr[i].sh_type == SHT_PROGBITS
 825 #ifdef __amd64__
 826                             || shdr[i].sh_type == SHT_X86_64_UNWIND
 827 #endif
 828                             ) {
 829                                 error = vn_rdwr(UIO_READ, nd.ni_vp,
 830                                     ef->progtab[pb].addr,
 831                                     shdr[i].sh_size, shdr[i].sh_offset,
 832                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
 833                                     NOCRED, &resid, td);
 834                                 if (error)
 835                                         goto out;
 836                                 if (resid != 0){
 837                                         error = EINVAL;
 838                                         goto out;
 839                                 }
 840                                 /* Initialize the per-cpu or vnet area. */
 841                                 if (ef->progtab[pb].addr != (void *)mapbase &&
 842                                     !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 843                                         dpcpu_copy(ef->progtab[pb].addr,
 844                                             shdr[i].sh_size);
 845 #ifdef VIMAGE
 846                                 else if (ef->progtab[pb].addr !=
 847                                     (void *)mapbase &&
 848                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 849                                         vnet_data_copy(ef->progtab[pb].addr,
 850                                             shdr[i].sh_size);
 851 #endif
 852                         } else
 853                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
 854
 855                         /* Update all symbol values with the offset. */
 856                         for (j = 0; j < ef->ddbsymcnt; j++) {
 857                                 es = &ef->ddbsymtab[j];
 858                                 if (es->st_shndx != i)
 859                                         continue;
 860                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 861                         }
 862                         mapbase += shdr[i].sh_size;
 863                         pb++;
 864                         break;
 865                 case SHT_REL:
 866                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
 867                             M_WAITOK);
 868                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 869                         ef->reltab[rl].sec = shdr[i].sh_info;
 870                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 871                             (void *)ef->reltab[rl].rel,
 872                             shdr[i].sh_size, shdr[i].sh_offset,
 873                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 874                             &resid, td);
 875                         if (error)
 876                                 goto out;
 877                         if (resid != 0){
 878                                 error = EINVAL;
 879                                 goto out;
 880                         }
 881                         rl++;
 882                         break;
 883                 case SHT_RELA:
 884                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
 885                             M_WAITOK);
 886                         ef->relatab[ra].nrela =
 887                             shdr[i].sh_size / sizeof(Elf_Rela);
 888                         ef->relatab[ra].sec = shdr[i].sh_info;
 889                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 890                             (void *)ef->relatab[ra].rela,
 891                             shdr[i].sh_size, shdr[i].sh_offset,
 892                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 893                             &resid, td);
 894                         if (error)
 895                                 goto out;
 896                         if (resid != 0){
 897                                 error = EINVAL;
 898                                 goto out;
 899                         }
 900                         ra++;
 901                         break;
 902                 }
 903         }
 904         if (pb != ef->nprogtab) {
 905                 link_elf_error(filename, "lost progbits");
 906                 error = ENOEXEC;
 907                 goto out;
 908         }
 909         if (rl != ef->nreltab) {
 910                 link_elf_error(filename, "lost reltab");
 911                 error = ENOEXEC;
 912                 goto out;
 913         }
 914         if (ra != ef->nrelatab) {
 915                 link_elf_error(filename, "lost relatab");
 916                 error = ENOEXEC;
 917                 goto out;
 918         }
 919         if (mapbase != (vm_offset_t)ef->address + mapsize) {
 920                 printf(
 921                     "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
 922                     filename != NULL ? filename : "<none>",
 923                     (u_long)mapbase, ef->address, (u_long)mapsize,
 924                     (u_long)(vm_offset_t)ef->address + mapsize);
 925                 error = ENOMEM;
 926                 goto out;
 927         }
 928
 929         /* Local intra-module relocations */
 930         error = link_elf_reloc_local(lf);
 931         if (error != 0)
 932                 goto out;
 933
 934         /* Pull in dependencies */
 935         VOP_UNLOCK(nd.ni_vp, 0);
 936         error = linker_load_dependencies(lf);
 937         vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
 938         if (error)
 939                 goto out;
 940
 941         /* External relocations */
 942         error = relocate_file(ef);
 943         if (error)
 944                 goto out;
 945
 946         /* Notify MD code that a module is being loaded. */
 947         error = elf_cpu_load_file(lf);
 948         if (error)
 949                 goto out;
 950
 951         /* Invoke .ctors */
 952         link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
 953
 954         *result = lf;
 955
 956 out:
 957         VOP_UNLOCK(nd.ni_vp, 0);
 958         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
 959         if (error && lf)
 960                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 961         free(hdr, M_LINKER);
 962
 963         return error;
 964 }
 965
 966 static void
 967 link_elf_unload_file(linker_file_t file)
 968 {
 969         elf_file_t ef = (elf_file_t) file;
 970         int i;
 971
 972         /* Notify MD code that a module is being unloaded. */
 973         elf_cpu_unload_file(file);
 974
 975         if (ef->progtab) {
 976                 for (i = 0; i < ef->nprogtab; i++) {
 977                         if (ef->progtab[i].size == 0)
 978                                 continue;
 979                         if (ef->progtab[i].name == NULL)
 980                                 continue;
 981                         if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
 982                                 dpcpu_free(ef->progtab[i].addr,
 983                                     ef->progtab[i].size);
 984 #ifdef VIMAGE
 985                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
 986                                 vnet_data_free(ef->progtab[i].addr,
 987                                     ef->progtab[i].size);
 988 #endif
 989                 }
 990         }
 991         if (ef->preloaded) {
 992                 free(ef->reltab, M_LINKER);
 993                 free(ef->relatab, M_LINKER);
 994                 free(ef->progtab, M_LINKER);
 995                 free(ef->ctftab, M_LINKER);
 996                 free(ef->ctfoff, M_LINKER);
 997                 free(ef->typoff, M_LINKER);
 998                 if (file->filename != NULL)
 999                         preload_delete_name(file->filename);
1000                 /* XXX reclaim module memory? */
1001                 return;
1002         }
1003
1004         for (i = 0; i < ef->nreltab; i++)
1005                 free(ef->reltab[i].rel, M_LINKER);
1006         for (i = 0; i < ef->nrelatab; i++)
1007                 free(ef->relatab[i].rela, M_LINKER);
1008         free(ef->reltab, M_LINKER);
1009         free(ef->relatab, M_LINKER);
1010         free(ef->progtab, M_LINKER);
1011
1012         if (ef->object) {
1013                 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1014                     (vm_offset_t) ef->address +
1015                     (ef->object->size << PAGE_SHIFT));
1016         }
1017         free(ef->e_shdr, M_LINKER);
1018         free(ef->ddbsymtab, M_LINKER);
1019         free(ef->ddbstrtab, M_LINKER);
1020         free(ef->shstrtab, M_LINKER);
1021         free(ef->ctftab, M_LINKER);
1022         free(ef->ctfoff, M_LINKER);
1023         free(ef->typoff, M_LINKER);
1024 }
1025
1026 static const char *
1027 symbol_name(elf_file_t ef, Elf_Size r_info)
1028 {
1029         const Elf_Sym *ref;
1030
1031         if (ELF_R_SYM(r_info)) {
1032                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1033                 return ef->ddbstrtab + ref->st_name;
1034         } else
1035                 return NULL;
1036 }
1037
1038 static Elf_Addr
1039 findbase(elf_file_t ef, int sec)
1040 {
1041         int i;
1042         Elf_Addr base = 0;
1043
1044         for (i = 0; i < ef->nprogtab; i++) {
1045                 if (sec == ef->progtab[i].sec) {
1046                         base = (Elf_Addr)ef->progtab[i].addr;
1047                         break;
1048                 }
1049         }
1050         return base;
1051 }
1052
1053 static int
1054 relocate_file(elf_file_t ef)
1055 {
1056         const Elf_Rel *rellim;
1057         const Elf_Rel *rel;
1058         const Elf_Rela *relalim;
1059         const Elf_Rela *rela;
1060         const char *symname;
1061         const Elf_Sym *sym;
1062         int i;
1063         Elf_Size symidx;
1064         Elf_Addr base;
1065
1066
1067         /* Perform relocations without addend if there are any: */
1068         for (i = 0; i < ef->nreltab; i++) {
1069                 rel = ef->reltab[i].rel;
1070                 if (rel == NULL) {
1071                         link_elf_error(ef->lf.filename, "lost a reltab!");
1072                         return (ENOEXEC);
1073                 }
1074                 rellim = rel + ef->reltab[i].nrel;
1075                 base = findbase(ef, ef->reltab[i].sec);
1076                 if (base == 0) {
1077                         link_elf_error(ef->lf.filename, "lost base for reltab");
1078                         return (ENOEXEC);
1079                 }
1080                 for ( ; rel < rellim; rel++) {
1081                         symidx = ELF_R_SYM(rel->r_info);
1082                         if (symidx >= ef->ddbsymcnt)
1083                                 continue;
1084                         sym = ef->ddbsymtab + symidx;
1085                         /* Local relocs are already done */
1086                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1087                                 continue;
1088                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1089                             elf_obj_lookup)) {
1090                                 symname = symbol_name(ef, rel->r_info);
1091                                 printf("link_elf_obj: symbol %s undefined\n",
1092                                     symname);
1093                                 return (ENOENT);
1094                         }
1095                 }
1096         }
1097
1098         /* Perform relocations with addend if there are any: */
1099         for (i = 0; i < ef->nrelatab; i++) {
1100                 rela = ef->relatab[i].rela;
1101                 if (rela == NULL) {
1102                         link_elf_error(ef->lf.filename, "lost a relatab!");
1103                         return (ENOEXEC);
1104                 }
1105                 relalim = rela + ef->relatab[i].nrela;
1106                 base = findbase(ef, ef->relatab[i].sec);
1107                 if (base == 0) {
1108                         link_elf_error(ef->lf.filename,
1109                             "lost base for relatab");
1110                         return (ENOEXEC);
1111                 }
1112                 for ( ; rela < relalim; rela++) {
1113                         symidx = ELF_R_SYM(rela->r_info);
1114                         if (symidx >= ef->ddbsymcnt)
1115                                 continue;
1116                         sym = ef->ddbsymtab + symidx;
1117                         /* Local relocs are already done */
1118                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1119                                 continue;
1120                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1121                             elf_obj_lookup)) {
1122                                 symname = symbol_name(ef, rela->r_info);
1123                                 printf("link_elf_obj: symbol %s undefined\n",
1124                                     symname);
1125                                 return (ENOENT);
1126                         }
1127                 }
1128         }
1129
1130         /*
1131          * Only clean SHN_FBSD_CACHED for successful return.  If we
1132          * modified symbol table for the object but found an
1133          * unresolved symbol, there is no reason to roll back.
1134          */
1135         elf_obj_cleanup_globals_cache(ef);
1136
1137         return (0);
1138 }
1139
1140 static int
1141 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1142 {
1143         elf_file_t ef = (elf_file_t) lf;
1144         const Elf_Sym *symp;
1145         const char *strp;
1146         int i;
1147
1148         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1149                 strp = ef->ddbstrtab + symp->st_name;
1150                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1151                         *sym = (c_linker_sym_t) symp;
1152                         return 0;
1153                 }
1154         }
1155         return ENOENT;
1156 }
1157
1158 static int
1159 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1160     linker_symval_t *symval)
1161 {
1162         elf_file_t ef = (elf_file_t) lf;
1163         const Elf_Sym *es = (const Elf_Sym*) sym;
1164
1165         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1166                 symval->name = ef->ddbstrtab + es->st_name;
1167                 symval->value = (caddr_t)es->st_value;
1168                 symval->size = es->st_size;
1169                 return 0;
1170         }
1171         return ENOENT;
1172 }
1173
1174 static int
1175 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1176     c_linker_sym_t *sym, long *diffp)
1177 {
1178         elf_file_t ef = (elf_file_t) lf;
1179         u_long off = (uintptr_t) (void *) value;
1180         u_long diff = off;
1181         u_long st_value;
1182         const Elf_Sym *es;
1183         const Elf_Sym *best = NULL;
1184         int i;
1185
1186         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1187                 if (es->st_name == 0)
1188                         continue;
1189                 st_value = es->st_value;
1190                 if (off >= st_value) {
1191                         if (off - st_value < diff) {
1192                                 diff = off - st_value;
1193                                 best = es;
1194                                 if (diff == 0)
1195                                         break;
1196                         } else if (off - st_value == diff) {
1197                                 best = es;
1198                         }
1199                 }
1200         }
1201         if (best == NULL)
1202                 *diffp = off;
1203         else
1204                 *diffp = diff;
1205         *sym = (c_linker_sym_t) best;
1206
1207         return 0;
1208 }
1209
1210 /*
1211  * Look up a linker set on an ELF system.
1212  */
1213 static int
1214 link_elf_lookup_set(linker_file_t lf, const char *name,
1215     void ***startp, void ***stopp, int *countp)
1216 {
1217         elf_file_t ef = (elf_file_t)lf;
1218         void **start, **stop;
1219         int i, count;
1220
1221         /* Relative to section number */
1222         for (i = 0; i < ef->nprogtab; i++) {
1223                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1224                     strcmp(ef->progtab[i].name + 4, name) == 0) {
1225                         start  = (void **)ef->progtab[i].addr;
1226                         stop = (void **)((char *)ef->progtab[i].addr +
1227                             ef->progtab[i].size);
1228                         count = stop - start;
1229                         if (startp)
1230                                 *startp = start;
1231                         if (stopp)
1232                                 *stopp = stop;
1233                         if (countp)
1234                                 *countp = count;
1235                         return (0);
1236                 }
1237         }
1238         return (ESRCH);
1239 }
1240
1241 static int
1242 link_elf_each_function_name(linker_file_t file,
1243     int (*callback)(const char *, void *), void *opaque)
1244 {
1245         elf_file_t ef = (elf_file_t)file;
1246         const Elf_Sym *symp;
1247         int i, error;
1248
1249         /* Exhaustive search */
1250         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1251                 if (symp->st_value != 0 &&
1252                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1253                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
1254                         if (error)
1255                                 return (error);
1256                 }
1257         }
1258         return (0);
1259 }
1260
1261 static int
1262 link_elf_each_function_nameval(linker_file_t file,
1263     linker_function_nameval_callback_t callback, void *opaque)
1264 {
1265         linker_symval_t symval;
1266         elf_file_t ef = (elf_file_t)file;
1267         const Elf_Sym* symp;
1268         int i, error;
1269
1270         /* Exhaustive search */
1271         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1272                 if (symp->st_value != 0 &&
1273                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1274                         error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1275                         if (error)
1276                                 return (error);
1277                         error = callback(file, i, &symval, opaque);
1278                         if (error)
1279                                 return (error);
1280                 }
1281         }
1282         return (0);
1283 }
1284
1285 static void
1286 elf_obj_cleanup_globals_cache(elf_file_t ef)
1287 {
1288         Elf_Sym *sym;
1289         Elf_Size i;
1290
1291         for (i = 0; i < ef->ddbsymcnt; i++) {
1292                 sym = ef->ddbsymtab + i;
1293                 if (sym->st_shndx == SHN_FBSD_CACHED) {
1294                         sym->st_shndx = SHN_UNDEF;
1295                         sym->st_value = 0;
1296                 }
1297         }
1298 }
1299
1300 /*
1301  * Symbol lookup function that can be used when the symbol index is known (ie
1302  * in relocations). It uses the symbol index instead of doing a fully fledged
1303  * hash table based lookup when such is valid. For example for local symbols.
1304  * This is not only more efficient, it's also more correct. It's not always
1305  * the case that the symbol can be found through the hash table.
1306  */
1307 static int
1308 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1309 {
1310         elf_file_t ef = (elf_file_t)lf;
1311         Elf_Sym *sym;
1312         const char *symbol;
1313         Elf_Addr res1;
1314
1315         /* Don't even try to lookup the symbol if the index is bogus. */
1316         if (symidx >= ef->ddbsymcnt) {
1317                 *res = 0;
1318                 return (EINVAL);
1319         }
1320
1321         sym = ef->ddbsymtab + symidx;
1322
1323         /* Quick answer if there is a definition included. */
1324         if (sym->st_shndx != SHN_UNDEF) {
1325                 *res = sym->st_value;
1326                 return (0);
1327         }
1328
1329         /* If we get here, then it is undefined and needs a lookup. */
1330         switch (ELF_ST_BIND(sym->st_info)) {
1331         case STB_LOCAL:
1332                 /* Local, but undefined? huh? */
1333                 *res = 0;
1334                 return (EINVAL);
1335
1336         case STB_GLOBAL:
1337         case STB_WEAK:
1338                 /* Relative to Data or Function name */
1339                 symbol = ef->ddbstrtab + sym->st_name;
1340
1341                 /* Force a lookup failure if the symbol name is bogus. */
1342                 if (*symbol == 0) {
1343                         *res = 0;
1344                         return (EINVAL);
1345                 }
1346                 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1347
1348                 /*
1349                  * Cache global lookups during module relocation. The failure
1350                  * case is particularly expensive for callers, who must scan
1351                  * through the entire globals table doing strcmp(). Cache to
1352                  * avoid doing such work repeatedly.
1353                  *
1354                  * After relocation is complete, undefined globals will be
1355                  * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1356                  * above.
1357                  */
1358                 if (res1 != 0) {
1359                         sym->st_shndx = SHN_FBSD_CACHED;
1360                         sym->st_value = res1;
1361                         *res = res1;
1362                         return (0);
1363                 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1364                         sym->st_value = 0;
1365                         *res = 0;
1366                         return (0);
1367                 }
1368                 return (EINVAL);
1369
1370         default:
1371                 return (EINVAL);
1372         }
1373 }
1374
1375 static void
1376 link_elf_fix_link_set(elf_file_t ef)
1377 {
1378         static const char startn[] = "__start_";
1379         static const char stopn[] = "__stop_";
1380         Elf_Sym *sym;
1381         const char *sym_name, *linkset_name;
1382         Elf_Addr startp, stopp;
1383         Elf_Size symidx;
1384         int start, i;
1385
1386         startp = stopp = 0;
1387         for (symidx = 1 /* zero entry is special */;
1388                 symidx < ef->ddbsymcnt; symidx++) {
1389                 sym = ef->ddbsymtab + symidx;
1390                 if (sym->st_shndx != SHN_UNDEF)
1391                         continue;
1392
1393                 sym_name = ef->ddbstrtab + sym->st_name;
1394                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1395                         start = 1;
1396                         linkset_name = sym_name + sizeof(startn) - 1;
1397                 }
1398                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1399                         start = 0;
1400                         linkset_name = sym_name + sizeof(stopn) - 1;
1401                 }
1402                 else
1403                         continue;
1404
1405                 for (i = 0; i < ef->nprogtab; i++) {
1406                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1407                                 startp = (Elf_Addr)ef->progtab[i].addr;
1408                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1409                                 break;
1410                         }
1411                 }
1412                 if (i == ef->nprogtab)
1413                         continue;
1414
1415                 sym->st_value = start ? startp : stopp;
1416                 sym->st_shndx = i;
1417         }
1418 }
1419
1420 static int
1421 link_elf_reloc_local(linker_file_t lf)
1422 {
1423         elf_file_t ef = (elf_file_t)lf;
1424         const Elf_Rel *rellim;
1425         const Elf_Rel *rel;
1426         const Elf_Rela *relalim;
1427         const Elf_Rela *rela;
1428         const Elf_Sym *sym;
1429         Elf_Addr base;
1430         int i;
1431         Elf_Size symidx;
1432
1433         link_elf_fix_link_set(ef);
1434
1435         /* Perform relocations without addend if there are any: */
1436         for (i = 0; i < ef->nreltab; i++) {
1437                 rel = ef->reltab[i].rel;
1438                 if (rel == NULL) {
1439                         link_elf_error(ef->lf.filename, "lost a reltab");
1440                         return (ENOEXEC);
1441                 }
1442                 rellim = rel + ef->reltab[i].nrel;
1443                 base = findbase(ef, ef->reltab[i].sec);
1444                 if (base == 0) {
1445                         link_elf_error(ef->lf.filename, "lost base for reltab");
1446                         return (ENOEXEC);
1447                 }
1448                 for ( ; rel < rellim; rel++) {
1449                         symidx = ELF_R_SYM(rel->r_info);
1450                         if (symidx >= ef->ddbsymcnt)
1451                                 continue;
1452                         sym = ef->ddbsymtab + symidx;
1453                         /* Only do local relocs */
1454                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1455                                 continue;
1456                         elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1457                             elf_obj_lookup);
1458                 }
1459         }
1460
1461         /* Perform relocations with addend if there are any: */
1462         for (i = 0; i < ef->nrelatab; i++) {
1463                 rela = ef->relatab[i].rela;
1464                 if (rela == NULL) {
1465                         link_elf_error(ef->lf.filename, "lost a relatab!");
1466                         return (ENOEXEC);
1467                 }
1468                 relalim = rela + ef->relatab[i].nrela;
1469                 base = findbase(ef, ef->relatab[i].sec);
1470                 if (base == 0) {
1471                         link_elf_error(ef->lf.filename, "lost base for reltab");
1472                         return (ENOEXEC);
1473                 }
1474                 for ( ; rela < relalim; rela++) {
1475                         symidx = ELF_R_SYM(rela->r_info);
1476                         if (symidx >= ef->ddbsymcnt)
1477                                 continue;
1478                         sym = ef->ddbsymtab + symidx;
1479                         /* Only do local relocs */
1480                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1481                                 continue;
1482                         elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1483                             elf_obj_lookup);
1484                 }
1485         }
1486         return (0);
1487 }
1488
1489 static long
1490 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1491 {
1492     elf_file_t ef = (elf_file_t)lf;
1493
1494     *symtab = ef->ddbsymtab;
1495
1496     if (*symtab == NULL)
1497         return (0);
1498
1499     return (ef->ddbsymcnt);
1500 }
1501
1502 static long
1503 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1504 {
1505     elf_file_t ef = (elf_file_t)lf;
1506
1507     *strtab = ef->ddbstrtab;
1508
1509     if (*strtab == NULL)
1510         return (0);
1511
1512     return (ef->ddbstrcnt);
1513 }