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, bool);
 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                         /* Ignore sections not loaded by the loader. */
 264                         if (shdr[i].sh_addr == 0)
 265                                 break;
 266                         ef->nprogtab++;
 267                         break;
 268                 case SHT_SYMTAB:
 269                         symtabindex = i;
 270                         symstrindex = shdr[i].sh_link;
 271                         break;
 272                 case SHT_REL:
 273                         /*
 274                          * Ignore relocation tables for sections not
 275                          * loaded by the loader.
 276                          */
 277                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 278                                 break;
 279                         ef->nreltab++;
 280                         break;
 281                 case SHT_RELA:
 282                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 283                                 break;
 284                         ef->nrelatab++;
 285                         break;
 286                 }
 287         }
 288
 289         shstrindex = hdr->e_shstrndx;
 290         if (ef->nprogtab == 0 || symstrindex < 0 ||
 291             symstrindex >= hdr->e_shnum ||
 292             shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
 293             shstrindex >= hdr->e_shnum ||
 294             shdr[shstrindex].sh_type != SHT_STRTAB) {
 295                 printf("%s: bad/missing section headers\n", filename);
 296                 error = ENOEXEC;
 297                 goto out;
 298         }
 299
 300         /* Allocate space for tracking the load chunks */
 301         if (ef->nprogtab != 0)
 302                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 303                     M_LINKER, M_WAITOK | M_ZERO);
 304         if (ef->nreltab != 0)
 305                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 306                     M_LINKER, M_WAITOK | M_ZERO);
 307         if (ef->nrelatab != 0)
 308                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 309                     M_LINKER, M_WAITOK | M_ZERO);
 310         if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
 311             (ef->nreltab != 0 && ef->reltab == NULL) ||
 312             (ef->nrelatab != 0 && ef->relatab == NULL)) {
 313                 error = ENOMEM;
 314                 goto out;
 315         }
 316
 317         /* XXX, relocate the sh_addr fields saved by the loader. */
 318         off = 0;
 319         for (i = 0; i < hdr->e_shnum; i++) {
 320                 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
 321                         off = shdr[i].sh_addr;
 322         }
 323         for (i = 0; i < hdr->e_shnum; i++) {
 324                 if (shdr[i].sh_addr != 0)
 325                         shdr[i].sh_addr = shdr[i].sh_addr - off +
 326                             (Elf_Addr)ef->address;
 327         }
 328
 329         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 330         ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
 331         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 332         ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
 333         ef->shstrcnt = shdr[shstrindex].sh_size;
 334         ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
 335
 336         /* Now fill out progtab and the relocation tables. */
 337         pb = 0;
 338         rl = 0;
 339         ra = 0;
 340         for (i = 0; i < hdr->e_shnum; i++) {
 341                 switch (shdr[i].sh_type) {
 342                 case SHT_PROGBITS:
 343                 case SHT_NOBITS:
 344 #ifdef __amd64__
 345                 case SHT_X86_64_UNWIND:
 346 #endif
 347                         if (shdr[i].sh_addr == 0)
 348                                 break;
 349                         ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
 350                         if (shdr[i].sh_type == SHT_PROGBITS)
 351                                 ef->progtab[pb].name = "<<PROGBITS>>";
 352 #ifdef __amd64__
 353                         else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
 354                                 ef->progtab[pb].name = "<<UNWIND>>";
 355 #endif
 356                         else
 357                                 ef->progtab[pb].name = "<<NOBITS>>";
 358                         ef->progtab[pb].size = shdr[i].sh_size;
 359                         ef->progtab[pb].sec = i;
 360                         if (ef->shstrtab && shdr[i].sh_name != 0)
 361                                 ef->progtab[pb].name =
 362                                     ef->shstrtab + shdr[i].sh_name;
 363                         if (ef->progtab[pb].name != NULL &&
 364                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
 365                                 void *dpcpu;
 366
 367                                 dpcpu = dpcpu_alloc(shdr[i].sh_size);
 368                                 if (dpcpu == NULL) {
 369                                         printf("%s: pcpu module space is out "
 370                                             "of space; cannot allocate %#jx "
 371                                             "for %s\n", __func__,
 372                                             (uintmax_t)shdr[i].sh_size,
 373                                             filename);
 374                                         error = ENOSPC;
 375                                         goto out;
 376                                 }
 377                                 memcpy(dpcpu, ef->progtab[pb].addr,
 378                                     ef->progtab[pb].size);
 379                                 dpcpu_copy(dpcpu, shdr[i].sh_size);
 380                                 ef->progtab[pb].addr = dpcpu;
 381 #ifdef VIMAGE
 382                         } else if (ef->progtab[pb].name != NULL &&
 383                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
 384                                 void *vnet_data;
 385
 386                                 vnet_data = vnet_data_alloc(shdr[i].sh_size);
 387                                 if (vnet_data == NULL) {
 388                                         printf("%s: vnet module space is out "
 389                                             "of space; cannot allocate %#jx "
 390                                             "for %s\n", __func__,
 391                                             (uintmax_t)shdr[i].sh_size,
 392                                             filename);
 393                                         error = ENOSPC;
 394                                         goto out;
 395                                 }
 396                                 memcpy(vnet_data, ef->progtab[pb].addr,
 397                                     ef->progtab[pb].size);
 398                                 vnet_data_copy(vnet_data, shdr[i].sh_size);
 399                                 ef->progtab[pb].addr = vnet_data;
 400 #endif
 401                         } else if (ef->progtab[pb].name != NULL &&
 402                             !strcmp(ef->progtab[pb].name, ".ctors")) {
 403                                 lf->ctors_addr = ef->progtab[pb].addr;
 404                                 lf->ctors_size = shdr[i].sh_size;
 405                         }
 406
 407                         /* Update all symbol values with the offset. */
 408                         for (j = 0; j < ef->ddbsymcnt; j++) {
 409                                 es = &ef->ddbsymtab[j];
 410                                 if (es->st_shndx != i)
 411                                         continue;
 412                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 413                         }
 414                         pb++;
 415                         break;
 416                 case SHT_REL:
 417                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 418                                 break;
 419                         ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
 420                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 421                         ef->reltab[rl].sec = shdr[i].sh_info;
 422                         rl++;
 423                         break;
 424                 case SHT_RELA:
 425                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 426                                 break;
 427                         ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
 428                         ef->relatab[ra].nrela =
 429                             shdr[i].sh_size / sizeof(Elf_Rela);
 430                         ef->relatab[ra].sec = shdr[i].sh_info;
 431                         ra++;
 432                         break;
 433                 }
 434         }
 435         if (pb != ef->nprogtab) {
 436                 printf("%s: lost progbits\n", filename);
 437                 error = ENOEXEC;
 438                 goto out;
 439         }
 440         if (rl != ef->nreltab) {
 441                 printf("%s: lost reltab\n", filename);
 442                 error = ENOEXEC;
 443                 goto out;
 444         }
 445         if (ra != ef->nrelatab) {
 446                 printf("%s: lost relatab\n", filename);
 447                 error = ENOEXEC;
 448                 goto out;
 449         }
 450
 451         /* Local intra-module relocations */
 452         error = link_elf_reloc_local(lf, false);
 453         if (error != 0)
 454                 goto out;
 455         *result = lf;
 456         return (0);
 457
 458 out:
 459         /* preload not done this way */
 460         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 461         return (error);
 462 }
 463
 464 static void
 465 link_elf_invoke_ctors(caddr_t addr, size_t size)
 466 {
 467         void (**ctor)(void);
 468         size_t i, cnt;
 469
 470         if (addr == NULL || size == 0)
 471                 return;
 472         cnt = size / sizeof(*ctor);
 473         ctor = (void *)addr;
 474         for (i = 0; i < cnt; i++) {
 475                 if (ctor[i] != NULL)
 476                         (*ctor[i])();
 477         }
 478 }
 479
 480 static int
 481 link_elf_link_preload_finish(linker_file_t lf)
 482 {
 483         elf_file_t ef;
 484         int error;
 485
 486         ef = (elf_file_t)lf;
 487         error = relocate_file(ef);
 488         if (error)
 489                 return (error);
 490
 491         /* Notify MD code that a module is being loaded. */
 492         error = elf_cpu_load_file(lf);
 493         if (error)
 494                 return (error);
 495
 496 #if defined(__i386__) || defined(__amd64__)
 497         /* Now ifuncs. */
 498         error = link_elf_reloc_local(lf, true);
 499         if (error != 0)
 500                 return (error);
 501 #endif
 502
 503         /* Invoke .ctors */
 504         link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
 505         return (0);
 506 }
 507
 508 static int
 509 link_elf_load_file(linker_class_t cls, const char *filename,
 510     linker_file_t *result)
 511 {
 512         struct nameidata nd;
 513         struct thread *td = curthread;  /* XXX */
 514         Elf_Ehdr *hdr;
 515         Elf_Shdr *shdr;
 516         Elf_Sym *es;
 517         int nbytes, i, j;
 518         vm_offset_t mapbase;
 519         size_t mapsize;
 520         int error = 0;
 521         ssize_t resid;
 522         int flags;
 523         elf_file_t ef;
 524         linker_file_t lf;
 525         int symtabindex;
 526         int symstrindex;
 527         int shstrindex;
 528         int nsym;
 529         int pb, rl, ra;
 530         int alignmask;
 531
 532         shdr = NULL;
 533         lf = NULL;
 534         mapsize = 0;
 535         hdr = NULL;
 536
 537         NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
 538         flags = FREAD;
 539         error = vn_open(&nd, &flags, 0, NULL);
 540         if (error)
 541                 return error;
 542         NDFREE(&nd, NDF_ONLY_PNBUF);
 543         if (nd.ni_vp->v_type != VREG) {
 544                 error = ENOEXEC;
 545                 goto out;
 546         }
 547 #ifdef MAC
 548         error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
 549         if (error) {
 550                 goto out;
 551         }
 552 #endif
 553
 554         /* Read the elf header from the file. */
 555         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
 556         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
 557             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 558             &resid, td);
 559         if (error)
 560                 goto out;
 561         if (resid != 0){
 562                 error = ENOEXEC;
 563                 goto out;
 564         }
 565
 566         if (!IS_ELF(*hdr)) {
 567                 error = ENOEXEC;
 568                 goto out;
 569         }
 570
 571         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
 572             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
 573                 link_elf_error(filename, "Unsupported file layout");
 574                 error = ENOEXEC;
 575                 goto out;
 576         }
 577         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
 578             || hdr->e_version != EV_CURRENT) {
 579                 link_elf_error(filename, "Unsupported file version");
 580                 error = ENOEXEC;
 581                 goto out;
 582         }
 583         if (hdr->e_type != ET_REL) {
 584                 error = ENOSYS;
 585                 goto out;
 586         }
 587         if (hdr->e_machine != ELF_TARG_MACH) {
 588                 link_elf_error(filename, "Unsupported machine");
 589                 error = ENOEXEC;
 590                 goto out;
 591         }
 592
 593         lf = linker_make_file(filename, &link_elf_class);
 594         if (!lf) {
 595                 error = ENOMEM;
 596                 goto out;
 597         }
 598         ef = (elf_file_t) lf;
 599         ef->nprogtab = 0;
 600         ef->e_shdr = 0;
 601         ef->nreltab = 0;
 602         ef->nrelatab = 0;
 603
 604         /* Allocate and read in the section header */
 605         nbytes = hdr->e_shnum * hdr->e_shentsize;
 606         if (nbytes == 0 || hdr->e_shoff == 0 ||
 607             hdr->e_shentsize != sizeof(Elf_Shdr)) {
 608                 error = ENOEXEC;
 609                 goto out;
 610         }
 611         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
 612         ef->e_shdr = shdr;
 613         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
 614             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
 615         if (error)
 616                 goto out;
 617         if (resid) {
 618                 error = ENOEXEC;
 619                 goto out;
 620         }
 621
 622         /* Scan the section header for information and table sizing. */
 623         nsym = 0;
 624         symtabindex = -1;
 625         symstrindex = -1;
 626         for (i = 0; i < hdr->e_shnum; i++) {
 627                 if (shdr[i].sh_size == 0)
 628                         continue;
 629                 switch (shdr[i].sh_type) {
 630                 case SHT_PROGBITS:
 631                 case SHT_NOBITS:
 632 #ifdef __amd64__
 633                 case SHT_X86_64_UNWIND:
 634 #endif
 635                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 636                                 break;
 637                         ef->nprogtab++;
 638                         break;
 639                 case SHT_SYMTAB:
 640                         nsym++;
 641                         symtabindex = i;
 642                         symstrindex = shdr[i].sh_link;
 643                         break;
 644                 case SHT_REL:
 645                         /*
 646                          * Ignore relocation tables for unallocated
 647                          * sections.
 648                          */
 649                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
 650                                 break;
 651                         ef->nreltab++;
 652                         break;
 653                 case SHT_RELA:
 654                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
 655                                 break;
 656                         ef->nrelatab++;
 657                         break;
 658                 case SHT_STRTAB:
 659                         break;
 660                 }
 661         }
 662         if (ef->nprogtab == 0) {
 663                 link_elf_error(filename, "file has no contents");
 664                 error = ENOEXEC;
 665                 goto out;
 666         }
 667         if (nsym != 1) {
 668                 /* Only allow one symbol table for now */
 669                 link_elf_error(filename, "file has no valid symbol table");
 670                 error = ENOEXEC;
 671                 goto out;
 672         }
 673         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
 674             shdr[symstrindex].sh_type != SHT_STRTAB) {
 675                 link_elf_error(filename, "file has invalid symbol strings");
 676                 error = ENOEXEC;
 677                 goto out;
 678         }
 679
 680         /* Allocate space for tracking the load chunks */
 681         if (ef->nprogtab != 0)
 682                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 683                     M_LINKER, M_WAITOK | M_ZERO);
 684         if (ef->nreltab != 0)
 685                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 686                     M_LINKER, M_WAITOK | M_ZERO);
 687         if (ef->nrelatab != 0)
 688                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 689                     M_LINKER, M_WAITOK | M_ZERO);
 690
 691         if (symtabindex == -1) {
 692                 link_elf_error(filename, "lost symbol table index");
 693                 error = ENOEXEC;
 694                 goto out;
 695         }
 696         /* Allocate space for and load the symbol table */
 697         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 698         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
 699         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
 700             shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
 701             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 702             &resid, td);
 703         if (error)
 704                 goto out;
 705         if (resid != 0){
 706                 error = EINVAL;
 707                 goto out;
 708         }
 709
 710         if (symstrindex == -1) {
 711                 link_elf_error(filename, "lost symbol string index");
 712                 error = ENOEXEC;
 713                 goto out;
 714         }
 715         /* Allocate space for and load the symbol strings */
 716         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 717         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
 718         error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
 719             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
 720             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 721             &resid, td);
 722         if (error)
 723                 goto out;
 724         if (resid != 0){
 725                 error = EINVAL;
 726                 goto out;
 727         }
 728
 729         /* Do we have a string table for the section names?  */
 730         shstrindex = -1;
 731         if (hdr->e_shstrndx != 0 &&
 732             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
 733                 shstrindex = hdr->e_shstrndx;
 734                 ef->shstrcnt = shdr[shstrindex].sh_size;
 735                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
 736                     M_WAITOK);
 737                 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
 738                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
 739                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 740                     &resid, td);
 741                 if (error)
 742                         goto out;
 743                 if (resid != 0){
 744                         error = EINVAL;
 745                         goto out;
 746                 }
 747         }
 748
 749         /* Size up code/data(progbits) and bss(nobits). */
 750         alignmask = 0;
 751         for (i = 0; i < hdr->e_shnum; i++) {
 752                 if (shdr[i].sh_size == 0)
 753                         continue;
 754                 switch (shdr[i].sh_type) {
 755                 case SHT_PROGBITS:
 756                 case SHT_NOBITS:
 757 #ifdef __amd64__
 758                 case SHT_X86_64_UNWIND:
 759 #endif
 760                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 761                                 break;
 762                         alignmask = shdr[i].sh_addralign - 1;
 763                         mapsize += alignmask;
 764                         mapsize &= ~alignmask;
 765                         mapsize += shdr[i].sh_size;
 766                         break;
 767                 }
 768         }
 769
 770         /*
 771          * We know how much space we need for the text/data/bss/etc.
 772          * This stuff needs to be in a single chunk so that profiling etc
 773          * can get the bounds and gdb can associate offsets with modules
 774          */
 775         ef->object = vm_object_allocate(OBJT_DEFAULT,
 776             round_page(mapsize) >> PAGE_SHIFT);
 777         if (ef->object == NULL) {
 778                 error = ENOMEM;
 779                 goto out;
 780         }
 781         ef->address = (caddr_t) vm_map_min(kernel_map);
 782
 783         /*
 784          * In order to satisfy amd64's architectural requirements on the
 785          * location of code and data in the kernel's address space, request a
 786          * mapping that is above the kernel.
 787          */
 788 #ifdef __amd64__
 789         mapbase = KERNBASE;
 790 #else
 791         mapbase = VM_MIN_KERNEL_ADDRESS;
 792 #endif
 793         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
 794             round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
 795             VM_PROT_ALL, 0);
 796         if (error) {
 797                 vm_object_deallocate(ef->object);
 798                 ef->object = 0;
 799                 goto out;
 800         }
 801
 802         /* Wire the pages */
 803         error = vm_map_wire(kernel_map, mapbase,
 804             mapbase + round_page(mapsize),
 805             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 806         if (error != KERN_SUCCESS) {
 807                 error = ENOMEM;
 808                 goto out;
 809         }
 810
 811         /* Inform the kld system about the situation */
 812         lf->address = ef->address = (caddr_t)mapbase;
 813         lf->size = mapsize;
 814
 815         /*
 816          * Now load code/data(progbits), zero bss(nobits), allocate space for
 817          * and load relocs
 818          */
 819         pb = 0;
 820         rl = 0;
 821         ra = 0;
 822         alignmask = 0;
 823         for (i = 0; i < hdr->e_shnum; i++) {
 824                 if (shdr[i].sh_size == 0)
 825                         continue;
 826                 switch (shdr[i].sh_type) {
 827                 case SHT_PROGBITS:
 828                 case SHT_NOBITS:
 829 #ifdef __amd64__
 830                 case SHT_X86_64_UNWIND:
 831 #endif
 832                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 833                                 break;
 834                         alignmask = shdr[i].sh_addralign - 1;
 835                         mapbase += alignmask;
 836                         mapbase &= ~alignmask;
 837                         if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
 838                                 ef->progtab[pb].name =
 839                                     ef->shstrtab + shdr[i].sh_name;
 840                                 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
 841                                         lf->ctors_addr = (caddr_t)mapbase;
 842                                         lf->ctors_size = shdr[i].sh_size;
 843                                 }
 844                         } else if (shdr[i].sh_type == SHT_PROGBITS)
 845                                 ef->progtab[pb].name = "<<PROGBITS>>";
 846 #ifdef __amd64__
 847                         else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
 848                                 ef->progtab[pb].name = "<<UNWIND>>";
 849 #endif
 850                         else
 851                                 ef->progtab[pb].name = "<<NOBITS>>";
 852                         if (ef->progtab[pb].name != NULL &&
 853                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
 854                                 ef->progtab[pb].addr =
 855                                     dpcpu_alloc(shdr[i].sh_size);
 856                                 if (ef->progtab[pb].addr == NULL) {
 857                                         printf("%s: pcpu module space is out "
 858                                             "of space; cannot allocate %#jx "
 859                                             "for %s\n", __func__,
 860                                             (uintmax_t)shdr[i].sh_size,
 861                                             filename);
 862                                 }
 863                         }
 864 #ifdef VIMAGE
 865                         else if (ef->progtab[pb].name != NULL &&
 866                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
 867                                 ef->progtab[pb].addr =
 868                                     vnet_data_alloc(shdr[i].sh_size);
 869                                 if (ef->progtab[pb].addr == NULL) {
 870                                         printf("%s: vnet module space is out "
 871                                             "of space; cannot allocate %#jx "
 872                                             "for %s\n", __func__,
 873                                             (uintmax_t)shdr[i].sh_size,
 874                                             filename);
 875                                 }
 876                         }
 877 #endif
 878                         else
 879                                 ef->progtab[pb].addr =
 880                                     (void *)(uintptr_t)mapbase;
 881                         if (ef->progtab[pb].addr == NULL) {
 882                                 error = ENOSPC;
 883                                 goto out;
 884                         }
 885                         ef->progtab[pb].size = shdr[i].sh_size;
 886                         ef->progtab[pb].sec = i;
 887                         if (shdr[i].sh_type == SHT_PROGBITS
 888 #ifdef __amd64__
 889                             || shdr[i].sh_type == SHT_X86_64_UNWIND
 890 #endif
 891                             ) {
 892                                 error = vn_rdwr(UIO_READ, nd.ni_vp,
 893                                     ef->progtab[pb].addr,
 894                                     shdr[i].sh_size, shdr[i].sh_offset,
 895                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
 896                                     NOCRED, &resid, td);
 897                                 if (error)
 898                                         goto out;
 899                                 if (resid != 0){
 900                                         error = EINVAL;
 901                                         goto out;
 902                                 }
 903                                 /* Initialize the per-cpu or vnet area. */
 904                                 if (ef->progtab[pb].addr != (void *)mapbase &&
 905                                     !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
 906                                         dpcpu_copy(ef->progtab[pb].addr,
 907                                             shdr[i].sh_size);
 908 #ifdef VIMAGE
 909                                 else if (ef->progtab[pb].addr !=
 910                                     (void *)mapbase &&
 911                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
 912                                         vnet_data_copy(ef->progtab[pb].addr,
 913                                             shdr[i].sh_size);
 914 #endif
 915                         } else
 916                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
 917
 918                         /* Update all symbol values with the offset. */
 919                         for (j = 0; j < ef->ddbsymcnt; j++) {
 920                                 es = &ef->ddbsymtab[j];
 921                                 if (es->st_shndx != i)
 922                                         continue;
 923                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 924                         }
 925                         mapbase += shdr[i].sh_size;
 926                         pb++;
 927                         break;
 928                 case SHT_REL:
 929                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
 930                                 break;
 931                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
 932                             M_WAITOK);
 933                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 934                         ef->reltab[rl].sec = shdr[i].sh_info;
 935                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 936                             (void *)ef->reltab[rl].rel,
 937                             shdr[i].sh_size, shdr[i].sh_offset,
 938                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 939                             &resid, td);
 940                         if (error)
 941                                 goto out;
 942                         if (resid != 0){
 943                                 error = EINVAL;
 944                                 goto out;
 945                         }
 946                         rl++;
 947                         break;
 948                 case SHT_RELA:
 949                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
 950                                 break;
 951                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
 952                             M_WAITOK);
 953                         ef->relatab[ra].nrela =
 954                             shdr[i].sh_size / sizeof(Elf_Rela);
 955                         ef->relatab[ra].sec = shdr[i].sh_info;
 956                         error = vn_rdwr(UIO_READ, nd.ni_vp,
 957                             (void *)ef->relatab[ra].rela,
 958                             shdr[i].sh_size, shdr[i].sh_offset,
 959                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 960                             &resid, td);
 961                         if (error)
 962                                 goto out;
 963                         if (resid != 0){
 964                                 error = EINVAL;
 965                                 goto out;
 966                         }
 967                         ra++;
 968                         break;
 969                 }
 970         }
 971         if (pb != ef->nprogtab) {
 972                 link_elf_error(filename, "lost progbits");
 973                 error = ENOEXEC;
 974                 goto out;
 975         }
 976         if (rl != ef->nreltab) {
 977                 link_elf_error(filename, "lost reltab");
 978                 error = ENOEXEC;
 979                 goto out;
 980         }
 981         if (ra != ef->nrelatab) {
 982                 link_elf_error(filename, "lost relatab");
 983                 error = ENOEXEC;
 984                 goto out;
 985         }
 986         if (mapbase != (vm_offset_t)ef->address + mapsize) {
 987                 printf(
 988                     "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
 989                     filename != NULL ? filename : "<none>",
 990                     (u_long)mapbase, ef->address, (u_long)mapsize,
 991                     (u_long)(vm_offset_t)ef->address + mapsize);
 992                 error = ENOMEM;
 993                 goto out;
 994         }
 995
 996         /* Local intra-module relocations */
 997         error = link_elf_reloc_local(lf, false);
 998         if (error != 0)
 999                 goto out;
1000
1001         /* Pull in dependencies */
1002         VOP_UNLOCK(nd.ni_vp, 0);
1003         error = linker_load_dependencies(lf);
1004         vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
1005         if (error)
1006                 goto out;
1007
1008         /* External relocations */
1009         error = relocate_file(ef);
1010         if (error)
1011                 goto out;
1012
1013         /* Notify MD code that a module is being loaded. */
1014         error = elf_cpu_load_file(lf);
1015         if (error)
1016                 goto out;
1017
1018 #if defined(__i386__) || defined(__amd64__)
1019         /* Now ifuncs. */
1020         error = link_elf_reloc_local(lf, true);
1021         if (error != 0)
1022                 goto out;
1023 #endif
1024
1025         /* Invoke .ctors */
1026         link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
1027
1028         *result = lf;
1029
1030 out:
1031         VOP_UNLOCK(nd.ni_vp, 0);
1032         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1033         if (error && lf)
1034                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1035         free(hdr, M_LINKER);
1036
1037         return error;
1038 }
1039
1040 static void
1041 link_elf_unload_file(linker_file_t file)
1042 {
1043         elf_file_t ef = (elf_file_t) file;
1044         int i;
1045
1046         /* Notify MD code that a module is being unloaded. */
1047         elf_cpu_unload_file(file);
1048
1049         if (ef->progtab) {
1050                 for (i = 0; i < ef->nprogtab; i++) {
1051                         if (ef->progtab[i].size == 0)
1052                                 continue;
1053                         if (ef->progtab[i].name == NULL)
1054                                 continue;
1055                         if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
1056                                 dpcpu_free(ef->progtab[i].addr,
1057                                     ef->progtab[i].size);
1058 #ifdef VIMAGE
1059                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
1060                                 vnet_data_free(ef->progtab[i].addr,
1061                                     ef->progtab[i].size);
1062 #endif
1063                 }
1064         }
1065         if (ef->preloaded) {
1066                 free(ef->reltab, M_LINKER);
1067                 free(ef->relatab, M_LINKER);
1068                 free(ef->progtab, M_LINKER);
1069                 free(ef->ctftab, M_LINKER);
1070                 free(ef->ctfoff, M_LINKER);
1071                 free(ef->typoff, M_LINKER);
1072                 if (file->pathname != NULL)
1073                         preload_delete_name(file->pathname);
1074                 return;
1075         }
1076
1077         for (i = 0; i < ef->nreltab; i++)
1078                 free(ef->reltab[i].rel, M_LINKER);
1079         for (i = 0; i < ef->nrelatab; i++)
1080                 free(ef->relatab[i].rela, M_LINKER);
1081         free(ef->reltab, M_LINKER);
1082         free(ef->relatab, M_LINKER);
1083         free(ef->progtab, M_LINKER);
1084
1085         if (ef->object) {
1086                 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1087                     (vm_offset_t) ef->address +
1088                     (ef->object->size << PAGE_SHIFT));
1089         }
1090         free(ef->e_shdr, M_LINKER);
1091         free(ef->ddbsymtab, M_LINKER);
1092         free(ef->ddbstrtab, M_LINKER);
1093         free(ef->shstrtab, M_LINKER);
1094         free(ef->ctftab, M_LINKER);
1095         free(ef->ctfoff, M_LINKER);
1096         free(ef->typoff, M_LINKER);
1097 }
1098
1099 static const char *
1100 symbol_name(elf_file_t ef, Elf_Size r_info)
1101 {
1102         const Elf_Sym *ref;
1103
1104         if (ELF_R_SYM(r_info)) {
1105                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1106                 return ef->ddbstrtab + ref->st_name;
1107         } else
1108                 return NULL;
1109 }
1110
1111 static Elf_Addr
1112 findbase(elf_file_t ef, int sec)
1113 {
1114         int i;
1115         Elf_Addr base = 0;
1116
1117         for (i = 0; i < ef->nprogtab; i++) {
1118                 if (sec == ef->progtab[i].sec) {
1119                         base = (Elf_Addr)ef->progtab[i].addr;
1120                         break;
1121                 }
1122         }
1123         return base;
1124 }
1125
1126 static int
1127 relocate_file(elf_file_t ef)
1128 {
1129         const Elf_Rel *rellim;
1130         const Elf_Rel *rel;
1131         const Elf_Rela *relalim;
1132         const Elf_Rela *rela;
1133         const char *symname;
1134         const Elf_Sym *sym;
1135         int i;
1136         Elf_Size symidx;
1137         Elf_Addr base;
1138
1139
1140         /* Perform relocations without addend if there are any: */
1141         for (i = 0; i < ef->nreltab; i++) {
1142                 rel = ef->reltab[i].rel;
1143                 if (rel == NULL) {
1144                         link_elf_error(ef->lf.filename, "lost a reltab!");
1145                         return (ENOEXEC);
1146                 }
1147                 rellim = rel + ef->reltab[i].nrel;
1148                 base = findbase(ef, ef->reltab[i].sec);
1149                 if (base == 0) {
1150                         link_elf_error(ef->lf.filename, "lost base for reltab");
1151                         return (ENOEXEC);
1152                 }
1153                 for ( ; rel < rellim; rel++) {
1154                         symidx = ELF_R_SYM(rel->r_info);
1155                         if (symidx >= ef->ddbsymcnt)
1156                                 continue;
1157                         sym = ef->ddbsymtab + symidx;
1158                         /* Local relocs are already done */
1159                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1160                                 continue;
1161                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1162                             elf_obj_lookup)) {
1163                                 symname = symbol_name(ef, rel->r_info);
1164                                 printf("link_elf_obj: symbol %s undefined\n",
1165                                     symname);
1166                                 return (ENOENT);
1167                         }
1168                 }
1169         }
1170
1171         /* Perform relocations with addend if there are any: */
1172         for (i = 0; i < ef->nrelatab; i++) {
1173                 rela = ef->relatab[i].rela;
1174                 if (rela == NULL) {
1175                         link_elf_error(ef->lf.filename, "lost a relatab!");
1176                         return (ENOEXEC);
1177                 }
1178                 relalim = rela + ef->relatab[i].nrela;
1179                 base = findbase(ef, ef->relatab[i].sec);
1180                 if (base == 0) {
1181                         link_elf_error(ef->lf.filename,
1182                             "lost base for relatab");
1183                         return (ENOEXEC);
1184                 }
1185                 for ( ; rela < relalim; rela++) {
1186                         symidx = ELF_R_SYM(rela->r_info);
1187                         if (symidx >= ef->ddbsymcnt)
1188                                 continue;
1189                         sym = ef->ddbsymtab + symidx;
1190                         /* Local relocs are already done */
1191                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1192                                 continue;
1193                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1194                             elf_obj_lookup)) {
1195                                 symname = symbol_name(ef, rela->r_info);
1196                                 printf("link_elf_obj: symbol %s undefined\n",
1197                                     symname);
1198                                 return (ENOENT);
1199                         }
1200                 }
1201         }
1202
1203         /*
1204          * Only clean SHN_FBSD_CACHED for successful return.  If we
1205          * modified symbol table for the object but found an
1206          * unresolved symbol, there is no reason to roll back.
1207          */
1208         elf_obj_cleanup_globals_cache(ef);
1209
1210         return (0);
1211 }
1212
1213 static int
1214 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1215 {
1216         elf_file_t ef = (elf_file_t) lf;
1217         const Elf_Sym *symp;
1218         const char *strp;
1219         int i;
1220
1221         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1222                 strp = ef->ddbstrtab + symp->st_name;
1223                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1224                         *sym = (c_linker_sym_t) symp;
1225                         return 0;
1226                 }
1227         }
1228         return ENOENT;
1229 }
1230
1231 static int
1232 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1233     linker_symval_t *symval)
1234 {
1235         elf_file_t ef;
1236         const Elf_Sym *es;
1237         caddr_t val;
1238
1239         ef = (elf_file_t) lf;
1240         es = (const Elf_Sym*) sym;
1241         val = (caddr_t)es->st_value;
1242         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1243                 symval->name = ef->ddbstrtab + es->st_name;
1244                 val = (caddr_t)es->st_value;
1245                 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1246                         val = ((caddr_t (*)(void))val)();
1247                 symval->value = val;
1248                 symval->size = es->st_size;
1249                 return 0;
1250         }
1251         return ENOENT;
1252 }
1253
1254 static int
1255 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1256     c_linker_sym_t *sym, long *diffp)
1257 {
1258         elf_file_t ef = (elf_file_t) lf;
1259         u_long off = (uintptr_t) (void *) value;
1260         u_long diff = off;
1261         u_long st_value;
1262         const Elf_Sym *es;
1263         const Elf_Sym *best = NULL;
1264         int i;
1265
1266         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1267                 if (es->st_name == 0)
1268                         continue;
1269                 st_value = es->st_value;
1270                 if (off >= st_value) {
1271                         if (off - st_value < diff) {
1272                                 diff = off - st_value;
1273                                 best = es;
1274                                 if (diff == 0)
1275                                         break;
1276                         } else if (off - st_value == diff) {
1277                                 best = es;
1278                         }
1279                 }
1280         }
1281         if (best == NULL)
1282                 *diffp = off;
1283         else
1284                 *diffp = diff;
1285         *sym = (c_linker_sym_t) best;
1286
1287         return 0;
1288 }
1289
1290 /*
1291  * Look up a linker set on an ELF system.
1292  */
1293 static int
1294 link_elf_lookup_set(linker_file_t lf, const char *name,
1295     void ***startp, void ***stopp, int *countp)
1296 {
1297         elf_file_t ef = (elf_file_t)lf;
1298         void **start, **stop;
1299         int i, count;
1300
1301         /* Relative to section number */
1302         for (i = 0; i < ef->nprogtab; i++) {
1303                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1304                     strcmp(ef->progtab[i].name + 4, name) == 0) {
1305                         start  = (void **)ef->progtab[i].addr;
1306                         stop = (void **)((char *)ef->progtab[i].addr +
1307                             ef->progtab[i].size);
1308                         count = stop - start;
1309                         if (startp)
1310                                 *startp = start;
1311                         if (stopp)
1312                                 *stopp = stop;
1313                         if (countp)
1314                                 *countp = count;
1315                         return (0);
1316                 }
1317         }
1318         return (ESRCH);
1319 }
1320
1321 static int
1322 link_elf_each_function_name(linker_file_t file,
1323     int (*callback)(const char *, void *), void *opaque)
1324 {
1325         elf_file_t ef = (elf_file_t)file;
1326         const Elf_Sym *symp;
1327         int i, error;
1328
1329         /* Exhaustive search */
1330         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1331                 if (symp->st_value != 0 &&
1332                     (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1333                     ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1334                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
1335                         if (error)
1336                                 return (error);
1337                 }
1338         }
1339         return (0);
1340 }
1341
1342 static int
1343 link_elf_each_function_nameval(linker_file_t file,
1344     linker_function_nameval_callback_t callback, void *opaque)
1345 {
1346         linker_symval_t symval;
1347         elf_file_t ef = (elf_file_t)file;
1348         const Elf_Sym* symp;
1349         int i, error;
1350
1351         /* Exhaustive search */
1352         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1353                 if (symp->st_value != 0 &&
1354                     (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1355                     ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1356                         error = link_elf_symbol_values(file,
1357                             (c_linker_sym_t)symp, &symval);
1358                         if (error)
1359                                 return (error);
1360                         error = callback(file, i, &symval, opaque);
1361                         if (error)
1362                                 return (error);
1363                 }
1364         }
1365         return (0);
1366 }
1367
1368 static void
1369 elf_obj_cleanup_globals_cache(elf_file_t ef)
1370 {
1371         Elf_Sym *sym;
1372         Elf_Size i;
1373
1374         for (i = 0; i < ef->ddbsymcnt; i++) {
1375                 sym = ef->ddbsymtab + i;
1376                 if (sym->st_shndx == SHN_FBSD_CACHED) {
1377                         sym->st_shndx = SHN_UNDEF;
1378                         sym->st_value = 0;
1379                 }
1380         }
1381 }
1382
1383 /*
1384  * Symbol lookup function that can be used when the symbol index is known (ie
1385  * in relocations). It uses the symbol index instead of doing a fully fledged
1386  * hash table based lookup when such is valid. For example for local symbols.
1387  * This is not only more efficient, it's also more correct. It's not always
1388  * the case that the symbol can be found through the hash table.
1389  */
1390 static int
1391 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1392 {
1393         elf_file_t ef = (elf_file_t)lf;
1394         Elf_Sym *sym;
1395         const char *symbol;
1396         Elf_Addr res1;
1397
1398         /* Don't even try to lookup the symbol if the index is bogus. */
1399         if (symidx >= ef->ddbsymcnt) {
1400                 *res = 0;
1401                 return (EINVAL);
1402         }
1403
1404         sym = ef->ddbsymtab + symidx;
1405
1406         /* Quick answer if there is a definition included. */
1407         if (sym->st_shndx != SHN_UNDEF) {
1408                 res1 = (Elf_Addr)sym->st_value;
1409                 if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC)
1410                         res1 = ((Elf_Addr (*)(void))res1)();
1411                 *res = res1;
1412                 return (0);
1413         }
1414
1415         /* If we get here, then it is undefined and needs a lookup. */
1416         switch (ELF_ST_BIND(sym->st_info)) {
1417         case STB_LOCAL:
1418                 /* Local, but undefined? huh? */
1419                 *res = 0;
1420                 return (EINVAL);
1421
1422         case STB_GLOBAL:
1423         case STB_WEAK:
1424                 /* Relative to Data or Function name */
1425                 symbol = ef->ddbstrtab + sym->st_name;
1426
1427                 /* Force a lookup failure if the symbol name is bogus. */
1428                 if (*symbol == 0) {
1429                         *res = 0;
1430                         return (EINVAL);
1431                 }
1432                 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1433
1434                 /*
1435                  * Cache global lookups during module relocation. The failure
1436                  * case is particularly expensive for callers, who must scan
1437                  * through the entire globals table doing strcmp(). Cache to
1438                  * avoid doing such work repeatedly.
1439                  *
1440                  * After relocation is complete, undefined globals will be
1441                  * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1442                  * above.
1443                  */
1444                 if (res1 != 0) {
1445                         sym->st_shndx = SHN_FBSD_CACHED;
1446                         sym->st_value = res1;
1447                         *res = res1;
1448                         return (0);
1449                 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1450                         sym->st_value = 0;
1451                         *res = 0;
1452                         return (0);
1453                 }
1454                 return (EINVAL);
1455
1456         default:
1457                 return (EINVAL);
1458         }
1459 }
1460
1461 static void
1462 link_elf_fix_link_set(elf_file_t ef)
1463 {
1464         static const char startn[] = "__start_";
1465         static const char stopn[] = "__stop_";
1466         Elf_Sym *sym;
1467         const char *sym_name, *linkset_name;
1468         Elf_Addr startp, stopp;
1469         Elf_Size symidx;
1470         int start, i;
1471
1472         startp = stopp = 0;
1473         for (symidx = 1 /* zero entry is special */;
1474                 symidx < ef->ddbsymcnt; symidx++) {
1475                 sym = ef->ddbsymtab + symidx;
1476                 if (sym->st_shndx != SHN_UNDEF)
1477                         continue;
1478
1479                 sym_name = ef->ddbstrtab + sym->st_name;
1480                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1481                         start = 1;
1482                         linkset_name = sym_name + sizeof(startn) - 1;
1483                 }
1484                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1485                         start = 0;
1486                         linkset_name = sym_name + sizeof(stopn) - 1;
1487                 }
1488                 else
1489                         continue;
1490
1491                 for (i = 0; i < ef->nprogtab; i++) {
1492                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1493                                 startp = (Elf_Addr)ef->progtab[i].addr;
1494                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1495                                 break;
1496                         }
1497                 }
1498                 if (i == ef->nprogtab)
1499                         continue;
1500
1501                 sym->st_value = start ? startp : stopp;
1502                 sym->st_shndx = i;
1503         }
1504 }
1505
1506 static int
1507 link_elf_reloc_local(linker_file_t lf, bool ifuncs)
1508 {
1509         elf_file_t ef = (elf_file_t)lf;
1510         const Elf_Rel *rellim;
1511         const Elf_Rel *rel;
1512         const Elf_Rela *relalim;
1513         const Elf_Rela *rela;
1514         const Elf_Sym *sym;
1515         Elf_Addr base;
1516         int i;
1517         Elf_Size symidx;
1518
1519         link_elf_fix_link_set(ef);
1520
1521         /* Perform relocations without addend if there are any: */
1522         for (i = 0; i < ef->nreltab; i++) {
1523                 rel = ef->reltab[i].rel;
1524                 if (rel == NULL) {
1525                         link_elf_error(ef->lf.filename, "lost a reltab");
1526                         return (ENOEXEC);
1527                 }
1528                 rellim = rel + ef->reltab[i].nrel;
1529                 base = findbase(ef, ef->reltab[i].sec);
1530                 if (base == 0) {
1531                         link_elf_error(ef->lf.filename, "lost base for reltab");
1532                         return (ENOEXEC);
1533                 }
1534                 for ( ; rel < rellim; rel++) {
1535                         symidx = ELF_R_SYM(rel->r_info);
1536                         if (symidx >= ef->ddbsymcnt)
1537                                 continue;
1538                         sym = ef->ddbsymtab + symidx;
1539                         /* Only do local relocs */
1540                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1541                                 continue;
1542                         if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1543                             elf_is_ifunc_reloc(rel->r_info)) == ifuncs)
1544                                 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1545                                     elf_obj_lookup);
1546                 }
1547         }
1548
1549         /* Perform relocations with addend if there are any: */
1550         for (i = 0; i < ef->nrelatab; i++) {
1551                 rela = ef->relatab[i].rela;
1552                 if (rela == NULL) {
1553                         link_elf_error(ef->lf.filename, "lost a relatab!");
1554                         return (ENOEXEC);
1555                 }
1556                 relalim = rela + ef->relatab[i].nrela;
1557                 base = findbase(ef, ef->relatab[i].sec);
1558                 if (base == 0) {
1559                         link_elf_error(ef->lf.filename, "lost base for reltab");
1560                         return (ENOEXEC);
1561                 }
1562                 for ( ; rela < relalim; rela++) {
1563                         symidx = ELF_R_SYM(rela->r_info);
1564                         if (symidx >= ef->ddbsymcnt)
1565                                 continue;
1566                         sym = ef->ddbsymtab + symidx;
1567                         /* Only do local relocs */
1568                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1569                                 continue;
1570                         if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1571                             elf_is_ifunc_reloc(rela->r_info)) == ifuncs)
1572                                 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1573                                     elf_obj_lookup);
1574                 }
1575         }
1576         return (0);
1577 }
1578
1579 static long
1580 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1581 {
1582     elf_file_t ef = (elf_file_t)lf;
1583
1584     *symtab = ef->ddbsymtab;
1585
1586     if (*symtab == NULL)
1587         return (0);
1588
1589     return (ef->ddbsymcnt);
1590 }
1591
1592 static long
1593 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1594 {
1595     elf_file_t ef = (elf_file_t)lf;
1596
1597     *strtab = ef->ddbstrtab;
1598
1599     if (*strtab == NULL)
1600         return (0);
1601
1602     return (ef->ddbstrcnt);
1603 }