sys/kern/link_elf_obj.c

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