sys/kern/link_elf_obj.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 1998-2000 Doug Rabson
   5  * Copyright (c) 2004 Peter Wemm
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include <sys/cdefs.h>
  31 __FBSDID("$FreeBSD$");
  32
  33 #include "opt_ddb.h"
  34
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/fcntl.h>
  38 #include <sys/kernel.h>
  39 #include <sys/lock.h>
  40 #include <sys/malloc.h>
  41 #include <sys/linker.h>
  42 #include <sys/mutex.h>
  43 #include <sys/mount.h>
  44 #include <sys/namei.h>
  45 #include <sys/proc.h>
  46 #include <sys/rwlock.h>
  47 #include <sys/vnode.h>
  48
  49 #include <machine/elf.h>
  50
  51 #include <net/vnet.h>
  52
  53 #include <security/mac/mac_framework.h>
  54
  55 #include <vm/vm.h>
  56 #include <vm/vm_param.h>
  57 #include <vm/pmap.h>
  58 #include <vm/vm_extern.h>
  59 #include <vm/vm_kern.h>
  60 #include <vm/vm_map.h>
  61 #include <vm/vm_object.h>
  62 #include <vm/vm_page.h>
  63 #include <vm/vm_pager.h>
  64
  65 #include <sys/link_elf.h>
  66
  67 #ifdef DDB_CTF
  68 #include <sys/zlib.h>
  69 #endif
  70
  71 #include "linker_if.h"
  72
  73 typedef struct {
  74         void            *addr;
  75         Elf_Off         size;
  76         int             flags;  /* Section flags. */
  77         int             sec;    /* Original section number. */
  78         char            *name;
  79 } Elf_progent;
  80
  81 typedef struct {
  82         Elf_Rel         *rel;
  83         int             nrel;
  84         int             sec;
  85 } Elf_relent;
  86
  87 typedef struct {
  88         Elf_Rela        *rela;
  89         int             nrela;
  90         int             sec;
  91 } Elf_relaent;
  92
  93
  94 typedef struct elf_file {
  95         struct linker_file lf;          /* Common fields */
  96
  97         int             preloaded;
  98         caddr_t         address;        /* Relocation address */
  99         vm_object_t     object;         /* VM object to hold file pages */
 100         Elf_Shdr        *e_shdr;
 101
 102         Elf_progent     *progtab;
 103         u_int           nprogtab;
 104
 105         Elf_relaent     *relatab;
 106         u_int           nrelatab;
 107
 108         Elf_relent      *reltab;
 109         int             nreltab;
 110
 111         Elf_Sym         *ddbsymtab;     /* The symbol table we are using */
 112         long            ddbsymcnt;      /* Number of symbols */
 113         caddr_t         ddbstrtab;      /* String table */
 114         long            ddbstrcnt;      /* number of bytes in string table */
 115
 116         caddr_t         shstrtab;       /* Section name string table */
 117         long            shstrcnt;       /* number of bytes in string table */
 118
 119         caddr_t         ctftab;         /* CTF table */
 120         long            ctfcnt;         /* number of bytes in CTF table */
 121         caddr_t         ctfoff;         /* CTF offset table */
 122         caddr_t         typoff;         /* Type offset table */
 123         long            typlen;         /* Number of type entries. */
 124
 125 } *elf_file_t;
 126
 127 #include <kern/kern_ctf.c>
 128
 129 static int      link_elf_link_preload(linker_class_t cls,
 130                     const char *, linker_file_t *);
 131 static int      link_elf_link_preload_finish(linker_file_t);
 132 static int      link_elf_load_file(linker_class_t, const char *, linker_file_t *);
 133 static int      link_elf_lookup_symbol(linker_file_t, const char *,
 134                     c_linker_sym_t *);
 135 static int      link_elf_symbol_values(linker_file_t, c_linker_sym_t,
 136                     linker_symval_t *);
 137 static int      link_elf_search_symbol(linker_file_t, caddr_t value,
 138                     c_linker_sym_t *sym, long *diffp);
 139
 140 static void     link_elf_unload_file(linker_file_t);
 141 static int      link_elf_lookup_set(linker_file_t, const char *,
 142                     void ***, void ***, int *);
 143 static int      link_elf_each_function_name(linker_file_t,
 144                     int (*)(const char *, void *), void *);
 145 static int      link_elf_each_function_nameval(linker_file_t,
 146                                 linker_function_nameval_callback_t,
 147                                 void *);
 148 static int      link_elf_reloc_local(linker_file_t, bool);
 149 static long     link_elf_symtab_get(linker_file_t, const Elf_Sym **);
 150 static long     link_elf_strtab_get(linker_file_t, caddr_t *);
 151
 152 static int      elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps,
 153                     Elf_Addr *);
 154
 155 static kobj_method_t link_elf_methods[] = {
 156         KOBJMETHOD(linker_lookup_symbol,        link_elf_lookup_symbol),
 157         KOBJMETHOD(linker_symbol_values,        link_elf_symbol_values),
 158         KOBJMETHOD(linker_search_symbol,        link_elf_search_symbol),
 159         KOBJMETHOD(linker_unload,               link_elf_unload_file),
 160         KOBJMETHOD(linker_load_file,            link_elf_load_file),
 161         KOBJMETHOD(linker_link_preload,         link_elf_link_preload),
 162         KOBJMETHOD(linker_link_preload_finish,  link_elf_link_preload_finish),
 163         KOBJMETHOD(linker_lookup_set,           link_elf_lookup_set),
 164         KOBJMETHOD(linker_each_function_name,   link_elf_each_function_name),
 165         KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
 166         KOBJMETHOD(linker_ctf_get,              link_elf_ctf_get),
 167         KOBJMETHOD(linker_symtab_get,           link_elf_symtab_get),
 168         KOBJMETHOD(linker_strtab_get,           link_elf_strtab_get),
 169         KOBJMETHOD_END
 170 };
 171
 172 static struct linker_class link_elf_class = {
 173 #if ELF_TARG_CLASS == ELFCLASS32
 174         "elf32_obj",
 175 #else
 176         "elf64_obj",
 177 #endif
 178         link_elf_methods, sizeof(struct elf_file)
 179 };
 180
 181 static int      relocate_file(elf_file_t ef);
 182 static void     elf_obj_cleanup_globals_cache(elf_file_t);
 183
 184 static void
 185 link_elf_error(const char *filename, const char *s)
 186 {
 187         if (filename == NULL)
 188                 printf("kldload: %s\n", s);
 189         else
 190                 printf("kldload: %s: %s\n", filename, s);
 191 }
 192
 193 static void
 194 link_elf_init(void *arg)
 195 {
 196
 197         linker_add_class(&link_elf_class);
 198 }
 199
 200 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, NULL);
 201
 202 static void
 203 link_elf_protect_range(elf_file_t ef, vm_offset_t start, vm_offset_t end,
 204     vm_prot_t prot)
 205 {
 206         int error __unused;
 207
 208         KASSERT(start <= end && start >= (vm_offset_t)ef->address &&
 209             end <= round_page((vm_offset_t)ef->address + ef->lf.size),
 210             ("link_elf_protect_range: invalid range %#jx-%#jx",
 211             (uintmax_t)start, (uintmax_t)end));
 212
 213         if (start == end)
 214                 return;
 215         error = vm_map_protect(kernel_map, start, end, prot, FALSE);
 216         KASSERT(error == KERN_SUCCESS,
 217             ("link_elf_protect_range: vm_map_protect() returned %d", error));
 218 }
 219
 220 /*
 221  * Restrict permissions on linker file memory based on section flags.
 222  * Sections need not be page-aligned, so overlap within a page is possible.
 223  */
 224 static void
 225 link_elf_protect(elf_file_t ef)
 226 {
 227         vm_offset_t end, segend, segstart, start;
 228         vm_prot_t gapprot, prot, segprot;
 229         int i;
 230
 231         /*
 232          * If the file was preloaded, the last page may contain other preloaded
 233          * data which may need to be writeable.  ELF files are always
 234          * page-aligned, but other preloaded data, such as entropy or CPU
 235          * microcode may be loaded with a smaller alignment.
 236          */
 237         gapprot = ef->preloaded ? VM_PROT_RW : VM_PROT_READ;
 238
 239         start = end = (vm_offset_t)ef->address;
 240         prot = VM_PROT_READ;
 241         for (i = 0; i < ef->nprogtab; i++) {
 242                 /*
 243                  * VNET and DPCPU sections have their memory allocated by their
 244                  * respective subsystems.
 245                  */
 246                 if (ef->progtab[i].name != NULL && (
 247 #ifdef VIMAGE
 248                     strcmp(ef->progtab[i].name, VNET_SETNAME) == 0 ||
 249 #endif
 250                     strcmp(ef->progtab[i].name, DPCPU_SETNAME) == 0))
 251                         continue;
 252
 253                 segstart = trunc_page((vm_offset_t)ef->progtab[i].addr);
 254                 segend = round_page((vm_offset_t)ef->progtab[i].addr +
 255                     ef->progtab[i].size);
 256                 segprot = VM_PROT_READ;
 257                 if ((ef->progtab[i].flags & SHF_WRITE) != 0)
 258                         segprot |= VM_PROT_WRITE;
 259                 if ((ef->progtab[i].flags & SHF_EXECINSTR) != 0)
 260                         segprot |= VM_PROT_EXECUTE;
 261
 262                 if (end <= segstart) {
 263                         /*
 264                          * Case 1: there is no overlap between the previous
 265                          * segment and this one.  Apply protections to the
 266                          * previous segment, and protect the gap between the
 267                          * previous and current segments, if any.
 268                          */
 269                         link_elf_protect_range(ef, start, end, prot);
 270                         link_elf_protect_range(ef, end, segstart, gapprot);
 271
 272                         start = segstart;
 273                         end = segend;
 274                         prot = segprot;
 275                 } else if (start < segstart && end == segend) {
 276                         /*
 277                          * Case 2: the current segment is a subrange of the
 278                          * previous segment.  Apply protections to the
 279                          * non-overlapping portion of the previous segment.
 280                          */
 281                         link_elf_protect_range(ef, start, segstart, prot);
 282
 283                         start = segstart;
 284                         prot |= segprot;
 285                 } else if (end < segend) {
 286                         /*
 287                          * Case 3: there is partial overlap between the previous
 288                          * and current segments.  Apply protections to the
 289                          * non-overlapping portion of the previous segment, and
 290                          * then the overlap, which must use the union of the two
 291                          * segments' protections.
 292                          */
 293                         link_elf_protect_range(ef, start, segstart, prot);
 294                         link_elf_protect_range(ef, segstart, end,
 295                             prot | segprot);
 296                         start = end;
 297                         end = segend;
 298                         prot = segprot;
 299                 } else {
 300                         /*
 301                          * Case 4: the two segments reside in the same page.
 302                          */
 303                         prot |= segprot;
 304                 }
 305         }
 306
 307         /*
 308          * Fix up the last unprotected segment and trailing data.
 309          */
 310         link_elf_protect_range(ef, start, end, prot);
 311         link_elf_protect_range(ef, end,
 312             round_page((vm_offset_t)ef->address + ef->lf.size), gapprot);
 313 }
 314
 315 static int
 316 link_elf_link_preload(linker_class_t cls, const char *filename,
 317     linker_file_t *result)
 318 {
 319         Elf_Ehdr *hdr;
 320         Elf_Shdr *shdr;
 321         Elf_Sym *es;
 322         void *modptr, *baseptr, *sizeptr;
 323         char *type;
 324         elf_file_t ef;
 325         linker_file_t lf;
 326         Elf_Addr off;
 327         int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
 328
 329         /* Look to see if we have the file preloaded */
 330         modptr = preload_search_by_name(filename);
 331         if (modptr == NULL)
 332                 return ENOENT;
 333
 334         type = (char *)preload_search_info(modptr, MODINFO_TYPE);
 335         baseptr = preload_search_info(modptr, MODINFO_ADDR);
 336         sizeptr = preload_search_info(modptr, MODINFO_SIZE);
 337         hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
 338             MODINFOMD_ELFHDR);
 339         shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
 340             MODINFOMD_SHDR);
 341         if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
 342             " obj module") != 0 &&
 343             strcmp(type, "elf obj module") != 0)) {
 344                 return (EFTYPE);
 345         }
 346         if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
 347             shdr == NULL)
 348                 return (EINVAL);
 349
 350         lf = linker_make_file(filename, &link_elf_class);
 351         if (lf == NULL)
 352                 return (ENOMEM);
 353
 354         ef = (elf_file_t)lf;
 355         ef->preloaded = 1;
 356         ef->address = *(caddr_t *)baseptr;
 357         lf->address = *(caddr_t *)baseptr;
 358         lf->size = *(size_t *)sizeptr;
 359
 360         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
 361             hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
 362             hdr->e_ident[EI_VERSION] != EV_CURRENT ||
 363             hdr->e_version != EV_CURRENT ||
 364             hdr->e_type != ET_REL ||
 365             hdr->e_machine != ELF_TARG_MACH) {
 366                 error = EFTYPE;
 367                 goto out;
 368         }
 369         ef->e_shdr = shdr;
 370
 371         /* Scan the section header for information and table sizing. */
 372         symtabindex = -1;
 373         symstrindex = -1;
 374         for (i = 0; i < hdr->e_shnum; i++) {
 375                 switch (shdr[i].sh_type) {
 376                 case SHT_PROGBITS:
 377                 case SHT_NOBITS:
 378 #ifdef __amd64__
 379                 case SHT_X86_64_UNWIND:
 380 #endif
 381                         /* Ignore sections not loaded by the loader. */
 382                         if (shdr[i].sh_addr == 0)
 383                                 break;
 384                         ef->nprogtab++;
 385                         break;
 386                 case SHT_SYMTAB:
 387                         symtabindex = i;
 388                         symstrindex = shdr[i].sh_link;
 389                         break;
 390                 case SHT_REL:
 391                         /*
 392                          * Ignore relocation tables for sections not
 393                          * loaded by the loader.
 394                          */
 395                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 396                                 break;
 397                         ef->nreltab++;
 398                         break;
 399                 case SHT_RELA:
 400                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 401                                 break;
 402                         ef->nrelatab++;
 403                         break;
 404                 }
 405         }
 406
 407         shstrindex = hdr->e_shstrndx;
 408         if (ef->nprogtab == 0 || symstrindex < 0 ||
 409             symstrindex >= hdr->e_shnum ||
 410             shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
 411             shstrindex >= hdr->e_shnum ||
 412             shdr[shstrindex].sh_type != SHT_STRTAB) {
 413                 printf("%s: bad/missing section headers\n", filename);
 414                 error = ENOEXEC;
 415                 goto out;
 416         }
 417
 418         /* Allocate space for tracking the load chunks */
 419         if (ef->nprogtab != 0)
 420                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 421                     M_LINKER, M_WAITOK | M_ZERO);
 422         if (ef->nreltab != 0)
 423                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 424                     M_LINKER, M_WAITOK | M_ZERO);
 425         if (ef->nrelatab != 0)
 426                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 427                     M_LINKER, M_WAITOK | M_ZERO);
 428         if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
 429             (ef->nreltab != 0 && ef->reltab == NULL) ||
 430             (ef->nrelatab != 0 && ef->relatab == NULL)) {
 431                 error = ENOMEM;
 432                 goto out;
 433         }
 434
 435         /* XXX, relocate the sh_addr fields saved by the loader. */
 436         off = 0;
 437         for (i = 0; i < hdr->e_shnum; i++) {
 438                 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
 439                         off = shdr[i].sh_addr;
 440         }
 441         for (i = 0; i < hdr->e_shnum; i++) {
 442                 if (shdr[i].sh_addr != 0)
 443                         shdr[i].sh_addr = shdr[i].sh_addr - off +
 444                             (Elf_Addr)ef->address;
 445         }
 446
 447         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 448         ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
 449         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 450         ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
 451         ef->shstrcnt = shdr[shstrindex].sh_size;
 452         ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
 453
 454         /* Now fill out progtab and the relocation tables. */
 455         pb = 0;
 456         rl = 0;
 457         ra = 0;
 458         for (i = 0; i < hdr->e_shnum; i++) {
 459                 switch (shdr[i].sh_type) {
 460                 case SHT_PROGBITS:
 461                 case SHT_NOBITS:
 462 #ifdef __amd64__
 463                 case SHT_X86_64_UNWIND:
 464 #endif
 465                         if (shdr[i].sh_addr == 0)
 466                                 break;
 467                         ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
 468                         if (shdr[i].sh_type == SHT_PROGBITS)
 469                                 ef->progtab[pb].name = "<<PROGBITS>>";
 470 #ifdef __amd64__
 471                         else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
 472                                 ef->progtab[pb].name = "<<UNWIND>>";
 473 #endif
 474                         else
 475                                 ef->progtab[pb].name = "<<NOBITS>>";
 476                         ef->progtab[pb].size = shdr[i].sh_size;
 477                         ef->progtab[pb].flags = shdr[i].sh_flags;
 478                         ef->progtab[pb].sec = i;
 479                         if (ef->shstrtab && shdr[i].sh_name != 0)
 480                                 ef->progtab[pb].name =
 481                                     ef->shstrtab + shdr[i].sh_name;
 482                         if (ef->progtab[pb].name != NULL &&
 483                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
 484                                 void *dpcpu;
 485
 486                                 dpcpu = dpcpu_alloc(shdr[i].sh_size);
 487                                 if (dpcpu == NULL) {
 488                                         printf("%s: pcpu module space is out "
 489                                             "of space; cannot allocate %#jx "
 490                                             "for %s\n", __func__,
 491                                             (uintmax_t)shdr[i].sh_size,
 492                                             filename);
 493                                         error = ENOSPC;
 494                                         goto out;
 495                                 }
 496                                 memcpy(dpcpu, ef->progtab[pb].addr,
 497                                     ef->progtab[pb].size);
 498                                 dpcpu_copy(dpcpu, shdr[i].sh_size);
 499                                 ef->progtab[pb].addr = dpcpu;
 500 #ifdef VIMAGE
 501                         } else if (ef->progtab[pb].name != NULL &&
 502                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
 503                                 void *vnet_data;
 504
 505                                 vnet_data = vnet_data_alloc(shdr[i].sh_size);
 506                                 if (vnet_data == NULL) {
 507                                         printf("%s: vnet module space is out "
 508                                             "of space; cannot allocate %#jx "
 509                                             "for %s\n", __func__,
 510                                             (uintmax_t)shdr[i].sh_size,
 511                                             filename);
 512                                         error = ENOSPC;
 513                                         goto out;
 514                                 }
 515                                 memcpy(vnet_data, ef->progtab[pb].addr,
 516                                     ef->progtab[pb].size);
 517                                 vnet_data_copy(vnet_data, shdr[i].sh_size);
 518                                 ef->progtab[pb].addr = vnet_data;
 519 #endif
 520                         } else if (ef->progtab[pb].name != NULL &&
 521                             !strcmp(ef->progtab[pb].name, ".ctors")) {
 522                                 lf->ctors_addr = ef->progtab[pb].addr;
 523                                 lf->ctors_size = shdr[i].sh_size;
 524                         }
 525
 526                         /* Update all symbol values with the offset. */
 527                         for (j = 0; j < ef->ddbsymcnt; j++) {
 528                                 es = &ef->ddbsymtab[j];
 529                                 if (es->st_shndx != i)
 530                                         continue;
 531                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 532                         }
 533                         pb++;
 534                         break;
 535                 case SHT_REL:
 536                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 537                                 break;
 538                         ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
 539                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 540                         ef->reltab[rl].sec = shdr[i].sh_info;
 541                         rl++;
 542                         break;
 543                 case SHT_RELA:
 544                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 545                                 break;
 546                         ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
 547                         ef->relatab[ra].nrela =
 548                             shdr[i].sh_size / sizeof(Elf_Rela);
 549                         ef->relatab[ra].sec = shdr[i].sh_info;
 550                         ra++;
 551                         break;
 552                 }
 553         }
 554         if (pb != ef->nprogtab) {
 555                 printf("%s: lost progbits\n", filename);
 556                 error = ENOEXEC;
 557                 goto out;
 558         }
 559         if (rl != ef->nreltab) {
 560                 printf("%s: lost reltab\n", filename);
 561                 error = ENOEXEC;
 562                 goto out;
 563         }
 564         if (ra != ef->nrelatab) {
 565                 printf("%s: lost relatab\n", filename);
 566                 error = ENOEXEC;
 567                 goto out;
 568         }
 569
 570         /* Local intra-module relocations */
 571         error = link_elf_reloc_local(lf, false);
 572         if (error != 0)
 573                 goto out;
 574         *result = lf;
 575         return (0);
 576
 577 out:
 578         /* preload not done this way */
 579         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 580         return (error);
 581 }
 582
 583 static void
 584 link_elf_invoke_ctors(caddr_t addr, size_t size)
 585 {
 586         void (**ctor)(void);
 587         size_t i, cnt;
 588
 589         if (addr == NULL || size == 0)
 590                 return;
 591         cnt = size / sizeof(*ctor);
 592         ctor = (void *)addr;
 593         for (i = 0; i < cnt; i++) {
 594                 if (ctor[i] != NULL)
 595                         (*ctor[i])();
 596         }
 597 }
 598
 599 static int
 600 link_elf_link_preload_finish(linker_file_t lf)
 601 {
 602         elf_file_t ef;
 603         int error;
 604
 605         ef = (elf_file_t)lf;
 606         error = relocate_file(ef);
 607         if (error)
 608                 return (error);
 609
 610         /* Notify MD code that a module is being loaded. */
 611         error = elf_cpu_load_file(lf);
 612         if (error)
 613                 return (error);
 614
 615 #if defined(__i386__) || defined(__amd64__)
 616         /* Now ifuncs. */
 617         error = link_elf_reloc_local(lf, true);
 618         if (error != 0)
 619                 return (error);
 620 #endif
 621
 622         /* Invoke .ctors */
 623         link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
 624         return (0);
 625 }
 626
 627 static int
 628 link_elf_load_file(linker_class_t cls, const char *filename,
 629     linker_file_t *result)
 630 {
 631         struct nameidata *nd;
 632         struct thread *td = curthread;  /* XXX */
 633         Elf_Ehdr *hdr;
 634         Elf_Shdr *shdr;
 635         Elf_Sym *es;
 636         int nbytes, i, j;
 637         vm_offset_t mapbase;
 638         size_t mapsize;
 639         int error = 0;
 640         ssize_t resid;
 641         int flags;
 642         elf_file_t ef;
 643         linker_file_t lf;
 644         int symtabindex;
 645         int symstrindex;
 646         int shstrindex;
 647         int nsym;
 648         int pb, rl, ra;
 649         int alignmask;
 650
 651         shdr = NULL;
 652         lf = NULL;
 653         mapsize = 0;
 654         hdr = NULL;
 655
 656         nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK);
 657         NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
 658         flags = FREAD;
 659         error = vn_open(nd, &flags, 0, NULL);
 660         if (error) {
 661                 free(nd, M_TEMP);
 662                 return error;
 663         }
 664         NDFREE(nd, NDF_ONLY_PNBUF);
 665         if (nd->ni_vp->v_type != VREG) {
 666                 error = ENOEXEC;
 667                 goto out;
 668         }
 669 #ifdef MAC
 670         error = mac_kld_check_load(td->td_ucred, nd->ni_vp);
 671         if (error) {
 672                 goto out;
 673         }
 674 #endif
 675
 676         /* Read the elf header from the file. */
 677         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
 678         error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0,
 679             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 680             &resid, td);
 681         if (error)
 682                 goto out;
 683         if (resid != 0){
 684                 error = ENOEXEC;
 685                 goto out;
 686         }
 687
 688         if (!IS_ELF(*hdr)) {
 689                 error = ENOEXEC;
 690                 goto out;
 691         }
 692
 693         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
 694             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
 695                 link_elf_error(filename, "Unsupported file layout");
 696                 error = ENOEXEC;
 697                 goto out;
 698         }
 699         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
 700             || hdr->e_version != EV_CURRENT) {
 701                 link_elf_error(filename, "Unsupported file version");
 702                 error = ENOEXEC;
 703                 goto out;
 704         }
 705         if (hdr->e_type != ET_REL) {
 706                 error = ENOSYS;
 707                 goto out;
 708         }
 709         if (hdr->e_machine != ELF_TARG_MACH) {
 710                 link_elf_error(filename, "Unsupported machine");
 711                 error = ENOEXEC;
 712                 goto out;
 713         }
 714
 715         lf = linker_make_file(filename, &link_elf_class);
 716         if (!lf) {
 717                 error = ENOMEM;
 718                 goto out;
 719         }
 720         ef = (elf_file_t) lf;
 721         ef->nprogtab = 0;
 722         ef->e_shdr = 0;
 723         ef->nreltab = 0;
 724         ef->nrelatab = 0;
 725
 726         /* Allocate and read in the section header */
 727         nbytes = hdr->e_shnum * hdr->e_shentsize;
 728         if (nbytes == 0 || hdr->e_shoff == 0 ||
 729             hdr->e_shentsize != sizeof(Elf_Shdr)) {
 730                 error = ENOEXEC;
 731                 goto out;
 732         }
 733         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
 734         ef->e_shdr = shdr;
 735         error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes,
 736             hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
 737             NOCRED, &resid, td);
 738         if (error)
 739                 goto out;
 740         if (resid) {
 741                 error = ENOEXEC;
 742                 goto out;
 743         }
 744
 745         /* Scan the section header for information and table sizing. */
 746         nsym = 0;
 747         symtabindex = -1;
 748         symstrindex = -1;
 749         for (i = 0; i < hdr->e_shnum; i++) {
 750                 if (shdr[i].sh_size == 0)
 751                         continue;
 752                 switch (shdr[i].sh_type) {
 753                 case SHT_PROGBITS:
 754                 case SHT_NOBITS:
 755 #ifdef __amd64__
 756                 case SHT_X86_64_UNWIND:
 757 #endif
 758                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 759                                 break;
 760                         ef->nprogtab++;
 761                         break;
 762                 case SHT_SYMTAB:
 763                         nsym++;
 764                         symtabindex = i;
 765                         symstrindex = shdr[i].sh_link;
 766                         break;
 767                 case SHT_REL:
 768                         /*
 769                          * Ignore relocation tables for unallocated
 770                          * sections.
 771                          */
 772                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
 773                                 break;
 774                         ef->nreltab++;
 775                         break;
 776                 case SHT_RELA:
 777                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
 778                                 break;
 779                         ef->nrelatab++;
 780                         break;
 781                 case SHT_STRTAB:
 782                         break;
 783                 }
 784         }
 785         if (ef->nprogtab == 0) {
 786                 link_elf_error(filename, "file has no contents");
 787                 error = ENOEXEC;
 788                 goto out;
 789         }
 790         if (nsym != 1) {
 791                 /* Only allow one symbol table for now */
 792                 link_elf_error(filename,
 793                     "file must have exactly one symbol table");
 794                 error = ENOEXEC;
 795                 goto out;
 796         }
 797         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
 798             shdr[symstrindex].sh_type != SHT_STRTAB) {
 799                 link_elf_error(filename, "file has invalid symbol strings");
 800                 error = ENOEXEC;
 801                 goto out;
 802         }
 803
 804         /* Allocate space for tracking the load chunks */
 805         if (ef->nprogtab != 0)
 806                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 807                     M_LINKER, M_WAITOK | M_ZERO);
 808         if (ef->nreltab != 0)
 809                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 810                     M_LINKER, M_WAITOK | M_ZERO);
 811         if (ef->nrelatab != 0)
 812                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 813                     M_LINKER, M_WAITOK | M_ZERO);
 814
 815         if (symtabindex == -1) {
 816                 link_elf_error(filename, "lost symbol table index");
 817                 error = ENOEXEC;
 818                 goto out;
 819         }
 820         /* Allocate space for and load the symbol table */
 821         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 822         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
 823         error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab,
 824             shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
 825             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 826             &resid, td);
 827         if (error)
 828                 goto out;
 829         if (resid != 0){
 830                 error = EINVAL;
 831                 goto out;
 832         }
 833
 834         /* Allocate space for and load the symbol strings */
 835         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 836         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
 837         error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab,
 838             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
 839             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 840             &resid, td);
 841         if (error)
 842                 goto out;
 843         if (resid != 0){
 844                 error = EINVAL;
 845                 goto out;
 846         }
 847
 848         /* Do we have a string table for the section names?  */
 849         shstrindex = -1;
 850         if (hdr->e_shstrndx != 0 &&
 851             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
 852                 shstrindex = hdr->e_shstrndx;
 853                 ef->shstrcnt = shdr[shstrindex].sh_size;
 854                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
 855                     M_WAITOK);
 856                 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab,
 857                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
 858                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 859                     &resid, td);
 860                 if (error)
 861                         goto out;
 862                 if (resid != 0){
 863                         error = EINVAL;
 864                         goto out;
 865                 }
 866         }
 867
 868         /* Size up code/data(progbits) and bss(nobits). */
 869         alignmask = 0;
 870         for (i = 0; i < hdr->e_shnum; i++) {
 871                 if (shdr[i].sh_size == 0)
 872                         continue;
 873                 switch (shdr[i].sh_type) {
 874                 case SHT_PROGBITS:
 875                 case SHT_NOBITS:
 876 #ifdef __amd64__
 877                 case SHT_X86_64_UNWIND:
 878 #endif
 879                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 880                                 break;
 881                         alignmask = shdr[i].sh_addralign - 1;
 882                         mapsize += alignmask;
 883                         mapsize &= ~alignmask;
 884                         mapsize += shdr[i].sh_size;
 885                         break;
 886                 }
 887         }
 888
 889         /*
 890          * We know how much space we need for the text/data/bss/etc.
 891          * This stuff needs to be in a single chunk so that profiling etc
 892          * can get the bounds and gdb can associate offsets with modules
 893          */
 894         ef->object = vm_pager_allocate(OBJT_PHYS, NULL, round_page(mapsize),
 895             VM_PROT_ALL, 0, thread0.td_ucred);
 896         if (ef->object == NULL) {
 897                 error = ENOMEM;
 898                 goto out;
 899         }
 900
 901         /*
 902          * In order to satisfy amd64's architectural requirements on the
 903          * location of code and data in the kernel's address space, request a
 904          * mapping that is above the kernel.
 905          *
 906          * Protections will be restricted once relocations are applied.
 907          */
 908 #ifdef __amd64__
 909         mapbase = KERNBASE;
 910 #else
 911         mapbase = VM_MIN_KERNEL_ADDRESS;
 912 #endif
 913         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
 914             round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
 915             VM_PROT_ALL, 0);
 916         if (error != KERN_SUCCESS) {
 917                 vm_object_deallocate(ef->object);
 918                 ef->object = NULL;
 919                 error = ENOMEM;
 920                 goto out;
 921         }
 922
 923         /* Wire the pages */
 924         error = vm_map_wire(kernel_map, mapbase,
 925             mapbase + round_page(mapsize),
 926             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 927         if (error != KERN_SUCCESS) {
 928                 error = ENOMEM;
 929                 goto out;
 930         }
 931
 932         /* Inform the kld system about the situation */
 933         lf->address = ef->address = (caddr_t)mapbase;
 934         lf->size = mapsize;
 935
 936         /*
 937          * Now load code/data(progbits), zero bss(nobits), allocate space for
 938          * and load relocs
 939          */
 940         pb = 0;
 941         rl = 0;
 942         ra = 0;
 943         alignmask = 0;
 944         for (i = 0; i < hdr->e_shnum; i++) {
 945                 if (shdr[i].sh_size == 0)
 946                         continue;
 947                 switch (shdr[i].sh_type) {
 948                 case SHT_PROGBITS:
 949                 case SHT_NOBITS:
 950 #ifdef __amd64__
 951                 case SHT_X86_64_UNWIND:
 952 #endif
 953                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 954                                 break;
 955                         alignmask = shdr[i].sh_addralign - 1;
 956                         mapbase += alignmask;
 957                         mapbase &= ~alignmask;
 958                         if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
 959                                 ef->progtab[pb].name =
 960                                     ef->shstrtab + shdr[i].sh_name;
 961                                 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
 962                                         lf->ctors_addr = (caddr_t)mapbase;
 963                                         lf->ctors_size = shdr[i].sh_size;
 964                                 }
 965                         } else if (shdr[i].sh_type == SHT_PROGBITS)
 966                                 ef->progtab[pb].name = "<<PROGBITS>>";
 967 #ifdef __amd64__
 968                         else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
 969                                 ef->progtab[pb].name = "<<UNWIND>>";
 970 #endif
 971                         else
 972                                 ef->progtab[pb].name = "<<NOBITS>>";
 973                         if (ef->progtab[pb].name != NULL &&
 974                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
 975                                 ef->progtab[pb].addr =
 976                                     dpcpu_alloc(shdr[i].sh_size);
 977                                 if (ef->progtab[pb].addr == NULL) {
 978                                         printf("%s: pcpu module space is out "
 979                                             "of space; cannot allocate %#jx "
 980                                             "for %s\n", __func__,
 981                                             (uintmax_t)shdr[i].sh_size,
 982                                             filename);
 983                                 }
 984                         }
 985 #ifdef VIMAGE
 986                         else if (ef->progtab[pb].name != NULL &&
 987                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
 988                                 ef->progtab[pb].addr =
 989                                     vnet_data_alloc(shdr[i].sh_size);
 990                                 if (ef->progtab[pb].addr == NULL) {
 991                                         printf("%s: vnet module space is out "
 992                                             "of space; cannot allocate %#jx "
 993                                             "for %s\n", __func__,
 994                                             (uintmax_t)shdr[i].sh_size,
 995                                             filename);
 996                                 }
 997                         }
 998 #endif
 999                         else
1000                                 ef->progtab[pb].addr =
1001                                     (void *)(uintptr_t)mapbase;
1002                         if (ef->progtab[pb].addr == NULL) {
1003                                 error = ENOSPC;
1004                                 goto out;
1005                         }
1006                         ef->progtab[pb].size = shdr[i].sh_size;
1007                         ef->progtab[pb].flags = shdr[i].sh_flags;
1008                         ef->progtab[pb].sec = i;
1009                         if (shdr[i].sh_type == SHT_PROGBITS
1010 #ifdef __amd64__
1011                             || shdr[i].sh_type == SHT_X86_64_UNWIND
1012 #endif
1013                             ) {
1014                                 error = vn_rdwr(UIO_READ, nd->ni_vp,
1015                                     ef->progtab[pb].addr,
1016                                     shdr[i].sh_size, shdr[i].sh_offset,
1017                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
1018                                     NOCRED, &resid, td);
1019                                 if (error)
1020                                         goto out;
1021                                 if (resid != 0){
1022                                         error = EINVAL;
1023                                         goto out;
1024                                 }
1025                                 /* Initialize the per-cpu or vnet area. */
1026                                 if (ef->progtab[pb].addr != (void *)mapbase &&
1027                                     !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
1028                                         dpcpu_copy(ef->progtab[pb].addr,
1029                                             shdr[i].sh_size);
1030 #ifdef VIMAGE
1031                                 else if (ef->progtab[pb].addr !=
1032                                     (void *)mapbase &&
1033                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
1034                                         vnet_data_copy(ef->progtab[pb].addr,
1035                                             shdr[i].sh_size);
1036 #endif
1037                         } else
1038                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
1039
1040                         /* Update all symbol values with the offset. */
1041                         for (j = 0; j < ef->ddbsymcnt; j++) {
1042                                 es = &ef->ddbsymtab[j];
1043                                 if (es->st_shndx != i)
1044                                         continue;
1045                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
1046                         }
1047                         mapbase += shdr[i].sh_size;
1048                         pb++;
1049                         break;
1050                 case SHT_REL:
1051                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
1052                                 break;
1053                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
1054                             M_WAITOK);
1055                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
1056                         ef->reltab[rl].sec = shdr[i].sh_info;
1057                         error = vn_rdwr(UIO_READ, nd->ni_vp,
1058                             (void *)ef->reltab[rl].rel,
1059                             shdr[i].sh_size, shdr[i].sh_offset,
1060                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1061                             &resid, td);
1062                         if (error)
1063                                 goto out;
1064                         if (resid != 0){
1065                                 error = EINVAL;
1066                                 goto out;
1067                         }
1068                         rl++;
1069                         break;
1070                 case SHT_RELA:
1071                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
1072                                 break;
1073                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
1074                             M_WAITOK);
1075                         ef->relatab[ra].nrela =
1076                             shdr[i].sh_size / sizeof(Elf_Rela);
1077                         ef->relatab[ra].sec = shdr[i].sh_info;
1078                         error = vn_rdwr(UIO_READ, nd->ni_vp,
1079                             (void *)ef->relatab[ra].rela,
1080                             shdr[i].sh_size, shdr[i].sh_offset,
1081                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1082                             &resid, td);
1083                         if (error)
1084                                 goto out;
1085                         if (resid != 0){
1086                                 error = EINVAL;
1087                                 goto out;
1088                         }
1089                         ra++;
1090                         break;
1091                 }
1092         }
1093         if (pb != ef->nprogtab) {
1094                 link_elf_error(filename, "lost progbits");
1095                 error = ENOEXEC;
1096                 goto out;
1097         }
1098         if (rl != ef->nreltab) {
1099                 link_elf_error(filename, "lost reltab");
1100                 error = ENOEXEC;
1101                 goto out;
1102         }
1103         if (ra != ef->nrelatab) {
1104                 link_elf_error(filename, "lost relatab");
1105                 error = ENOEXEC;
1106                 goto out;
1107         }
1108         if (mapbase != (vm_offset_t)ef->address + mapsize) {
1109                 printf(
1110                     "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
1111                     filename != NULL ? filename : "<none>",
1112                     (u_long)mapbase, ef->address, (u_long)mapsize,
1113                     (u_long)(vm_offset_t)ef->address + mapsize);
1114                 error = ENOMEM;
1115                 goto out;
1116         }
1117
1118         /* Local intra-module relocations */
1119         error = link_elf_reloc_local(lf, false);
1120         if (error != 0)
1121                 goto out;
1122
1123         /* Pull in dependencies */
1124         VOP_UNLOCK(nd->ni_vp, 0);
1125         error = linker_load_dependencies(lf);
1126         vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY);
1127         if (error)
1128                 goto out;
1129
1130         /* External relocations */
1131         error = relocate_file(ef);
1132         if (error)
1133                 goto out;
1134
1135         /* Notify MD code that a module is being loaded. */
1136         error = elf_cpu_load_file(lf);
1137         if (error)
1138                 goto out;
1139
1140 #if defined(__i386__) || defined(__amd64__)
1141         /* Now ifuncs. */
1142         error = link_elf_reloc_local(lf, true);
1143         if (error != 0)
1144                 goto out;
1145 #endif
1146
1147         link_elf_protect(ef);
1148         link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
1149         *result = lf;
1150
1151 out:
1152         VOP_UNLOCK(nd->ni_vp, 0);
1153         vn_close(nd->ni_vp, FREAD, td->td_ucred, td);
1154         free(nd, M_TEMP);
1155         if (error && lf)
1156                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1157         free(hdr, M_LINKER);
1158
1159         return error;
1160 }
1161
1162 static void
1163 link_elf_unload_file(linker_file_t file)
1164 {
1165         elf_file_t ef = (elf_file_t) file;
1166         u_int i;
1167
1168         /* Notify MD code that a module is being unloaded. */
1169         elf_cpu_unload_file(file);
1170
1171         if (ef->progtab) {
1172                 for (i = 0; i < ef->nprogtab; i++) {
1173                         if (ef->progtab[i].size == 0)
1174                                 continue;
1175                         if (ef->progtab[i].name == NULL)
1176                                 continue;
1177                         if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
1178                                 dpcpu_free(ef->progtab[i].addr,
1179                                     ef->progtab[i].size);
1180 #ifdef VIMAGE
1181                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
1182                                 vnet_data_free(ef->progtab[i].addr,
1183                                     ef->progtab[i].size);
1184 #endif
1185                 }
1186         }
1187         if (ef->preloaded) {
1188                 free(ef->reltab, M_LINKER);
1189                 free(ef->relatab, M_LINKER);
1190                 free(ef->progtab, M_LINKER);
1191                 free(ef->ctftab, M_LINKER);
1192                 free(ef->ctfoff, M_LINKER);
1193                 free(ef->typoff, M_LINKER);
1194                 if (file->pathname != NULL)
1195                         preload_delete_name(file->pathname);
1196                 return;
1197         }
1198
1199         for (i = 0; i < ef->nreltab; i++)
1200                 free(ef->reltab[i].rel, M_LINKER);
1201         for (i = 0; i < ef->nrelatab; i++)
1202                 free(ef->relatab[i].rela, M_LINKER);
1203         free(ef->reltab, M_LINKER);
1204         free(ef->relatab, M_LINKER);
1205         free(ef->progtab, M_LINKER);
1206
1207         if (ef->object != NULL)
1208                 vm_map_remove(kernel_map, (vm_offset_t)ef->address,
1209                     (vm_offset_t)ef->address + ptoa(ef->object->size));
1210         free(ef->e_shdr, M_LINKER);
1211         free(ef->ddbsymtab, M_LINKER);
1212         free(ef->ddbstrtab, M_LINKER);
1213         free(ef->shstrtab, M_LINKER);
1214         free(ef->ctftab, M_LINKER);
1215         free(ef->ctfoff, M_LINKER);
1216         free(ef->typoff, M_LINKER);
1217 }
1218
1219 static const char *
1220 symbol_name(elf_file_t ef, Elf_Size r_info)
1221 {
1222         const Elf_Sym *ref;
1223
1224         if (ELF_R_SYM(r_info)) {
1225                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1226                 return ef->ddbstrtab + ref->st_name;
1227         } else
1228                 return NULL;
1229 }
1230
1231 static Elf_Addr
1232 findbase(elf_file_t ef, int sec)
1233 {
1234         int i;
1235         Elf_Addr base = 0;
1236
1237         for (i = 0; i < ef->nprogtab; i++) {
1238                 if (sec == ef->progtab[i].sec) {
1239                         base = (Elf_Addr)ef->progtab[i].addr;
1240                         break;
1241                 }
1242         }
1243         return base;
1244 }
1245
1246 static int
1247 relocate_file(elf_file_t ef)
1248 {
1249         const Elf_Rel *rellim;
1250         const Elf_Rel *rel;
1251         const Elf_Rela *relalim;
1252         const Elf_Rela *rela;
1253         const char *symname;
1254         const Elf_Sym *sym;
1255         int i;
1256         Elf_Size symidx;
1257         Elf_Addr base;
1258
1259
1260         /* Perform relocations without addend if there are any: */
1261         for (i = 0; i < ef->nreltab; i++) {
1262                 rel = ef->reltab[i].rel;
1263                 if (rel == NULL) {
1264                         link_elf_error(ef->lf.filename, "lost a reltab!");
1265                         return (ENOEXEC);
1266                 }
1267                 rellim = rel + ef->reltab[i].nrel;
1268                 base = findbase(ef, ef->reltab[i].sec);
1269                 if (base == 0) {
1270                         link_elf_error(ef->lf.filename, "lost base for reltab");
1271                         return (ENOEXEC);
1272                 }
1273                 for ( ; rel < rellim; rel++) {
1274                         symidx = ELF_R_SYM(rel->r_info);
1275                         if (symidx >= ef->ddbsymcnt)
1276                                 continue;
1277                         sym = ef->ddbsymtab + symidx;
1278                         /* Local relocs are already done */
1279                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1280                                 continue;
1281                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1282                             elf_obj_lookup)) {
1283                                 symname = symbol_name(ef, rel->r_info);
1284                                 printf("link_elf_obj: symbol %s undefined\n",
1285                                     symname);
1286                                 return (ENOENT);
1287                         }
1288                 }
1289         }
1290
1291         /* Perform relocations with addend if there are any: */
1292         for (i = 0; i < ef->nrelatab; i++) {
1293                 rela = ef->relatab[i].rela;
1294                 if (rela == NULL) {
1295                         link_elf_error(ef->lf.filename, "lost a relatab!");
1296                         return (ENOEXEC);
1297                 }
1298                 relalim = rela + ef->relatab[i].nrela;
1299                 base = findbase(ef, ef->relatab[i].sec);
1300                 if (base == 0) {
1301                         link_elf_error(ef->lf.filename,
1302                             "lost base for relatab");
1303                         return (ENOEXEC);
1304                 }
1305                 for ( ; rela < relalim; rela++) {
1306                         symidx = ELF_R_SYM(rela->r_info);
1307                         if (symidx >= ef->ddbsymcnt)
1308                                 continue;
1309                         sym = ef->ddbsymtab + symidx;
1310                         /* Local relocs are already done */
1311                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1312                                 continue;
1313                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1314                             elf_obj_lookup)) {
1315                                 symname = symbol_name(ef, rela->r_info);
1316                                 printf("link_elf_obj: symbol %s undefined\n",
1317                                     symname);
1318                                 return (ENOENT);
1319                         }
1320                 }
1321         }
1322
1323         /*
1324          * Only clean SHN_FBSD_CACHED for successful return.  If we
1325          * modified symbol table for the object but found an
1326          * unresolved symbol, there is no reason to roll back.
1327          */
1328         elf_obj_cleanup_globals_cache(ef);
1329
1330         return (0);
1331 }
1332
1333 static int
1334 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1335 {
1336         elf_file_t ef = (elf_file_t) lf;
1337         const Elf_Sym *symp;
1338         const char *strp;
1339         int i;
1340
1341         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1342                 strp = ef->ddbstrtab + symp->st_name;
1343                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1344                         *sym = (c_linker_sym_t) symp;
1345                         return 0;
1346                 }
1347         }
1348         return ENOENT;
1349 }
1350
1351 static int
1352 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1353     linker_symval_t *symval)
1354 {
1355         elf_file_t ef;
1356         const Elf_Sym *es;
1357         caddr_t val;
1358
1359         ef = (elf_file_t) lf;
1360         es = (const Elf_Sym*) sym;
1361         val = (caddr_t)es->st_value;
1362         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1363                 symval->name = ef->ddbstrtab + es->st_name;
1364                 val = (caddr_t)es->st_value;
1365                 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1366                         val = ((caddr_t (*)(void))val)();
1367                 symval->value = val;
1368                 symval->size = es->st_size;
1369                 return 0;
1370         }
1371         return ENOENT;
1372 }
1373
1374 static int
1375 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1376     c_linker_sym_t *sym, long *diffp)
1377 {
1378         elf_file_t ef = (elf_file_t) lf;
1379         u_long off = (uintptr_t) (void *) value;
1380         u_long diff = off;
1381         u_long st_value;
1382         const Elf_Sym *es;
1383         const Elf_Sym *best = NULL;
1384         int i;
1385
1386         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1387                 if (es->st_name == 0)
1388                         continue;
1389                 st_value = es->st_value;
1390                 if (off >= st_value) {
1391                         if (off - st_value < diff) {
1392                                 diff = off - st_value;
1393                                 best = es;
1394                                 if (diff == 0)
1395                                         break;
1396                         } else if (off - st_value == diff) {
1397                                 best = es;
1398                         }
1399                 }
1400         }
1401         if (best == NULL)
1402                 *diffp = off;
1403         else
1404                 *diffp = diff;
1405         *sym = (c_linker_sym_t) best;
1406
1407         return 0;
1408 }
1409
1410 /*
1411  * Look up a linker set on an ELF system.
1412  */
1413 static int
1414 link_elf_lookup_set(linker_file_t lf, const char *name,
1415     void ***startp, void ***stopp, int *countp)
1416 {
1417         elf_file_t ef = (elf_file_t)lf;
1418         void **start, **stop;
1419         int i, count;
1420
1421         /* Relative to section number */
1422         for (i = 0; i < ef->nprogtab; i++) {
1423                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1424                     strcmp(ef->progtab[i].name + 4, name) == 0) {
1425                         start  = (void **)ef->progtab[i].addr;
1426                         stop = (void **)((char *)ef->progtab[i].addr +
1427                             ef->progtab[i].size);
1428                         count = stop - start;
1429                         if (startp)
1430                                 *startp = start;
1431                         if (stopp)
1432                                 *stopp = stop;
1433                         if (countp)
1434                                 *countp = count;
1435                         return (0);
1436                 }
1437         }
1438         return (ESRCH);
1439 }
1440
1441 static int
1442 link_elf_each_function_name(linker_file_t file,
1443     int (*callback)(const char *, void *), void *opaque)
1444 {
1445         elf_file_t ef = (elf_file_t)file;
1446         const Elf_Sym *symp;
1447         int i, error;
1448
1449         /* Exhaustive search */
1450         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1451                 if (symp->st_value != 0 &&
1452                     (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1453                     ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1454                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
1455                         if (error)
1456                                 return (error);
1457                 }
1458         }
1459         return (0);
1460 }
1461
1462 static int
1463 link_elf_each_function_nameval(linker_file_t file,
1464     linker_function_nameval_callback_t callback, void *opaque)
1465 {
1466         linker_symval_t symval;
1467         elf_file_t ef = (elf_file_t)file;
1468         const Elf_Sym* symp;
1469         int i, error;
1470
1471         /* Exhaustive search */
1472         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1473                 if (symp->st_value != 0 &&
1474                     (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1475                     ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1476                         error = link_elf_symbol_values(file,
1477                             (c_linker_sym_t)symp, &symval);
1478                         if (error)
1479                                 return (error);
1480                         error = callback(file, i, &symval, opaque);
1481                         if (error)
1482                                 return (error);
1483                 }
1484         }
1485         return (0);
1486 }
1487
1488 static void
1489 elf_obj_cleanup_globals_cache(elf_file_t ef)
1490 {
1491         Elf_Sym *sym;
1492         Elf_Size i;
1493
1494         for (i = 0; i < ef->ddbsymcnt; i++) {
1495                 sym = ef->ddbsymtab + i;
1496                 if (sym->st_shndx == SHN_FBSD_CACHED) {
1497                         sym->st_shndx = SHN_UNDEF;
1498                         sym->st_value = 0;
1499                 }
1500         }
1501 }
1502
1503 /*
1504  * Symbol lookup function that can be used when the symbol index is known (ie
1505  * in relocations). It uses the symbol index instead of doing a fully fledged
1506  * hash table based lookup when such is valid. For example for local symbols.
1507  * This is not only more efficient, it's also more correct. It's not always
1508  * the case that the symbol can be found through the hash table.
1509  */
1510 static int
1511 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1512 {
1513         elf_file_t ef = (elf_file_t)lf;
1514         Elf_Sym *sym;
1515         const char *symbol;
1516         Elf_Addr res1;
1517
1518         /* Don't even try to lookup the symbol if the index is bogus. */
1519         if (symidx >= ef->ddbsymcnt) {
1520                 *res = 0;
1521                 return (EINVAL);
1522         }
1523
1524         sym = ef->ddbsymtab + symidx;
1525
1526         /* Quick answer if there is a definition included. */
1527         if (sym->st_shndx != SHN_UNDEF) {
1528                 res1 = (Elf_Addr)sym->st_value;
1529                 if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC)
1530                         res1 = ((Elf_Addr (*)(void))res1)();
1531                 *res = res1;
1532                 return (0);
1533         }
1534
1535         /* If we get here, then it is undefined and needs a lookup. */
1536         switch (ELF_ST_BIND(sym->st_info)) {
1537         case STB_LOCAL:
1538                 /* Local, but undefined? huh? */
1539                 *res = 0;
1540                 return (EINVAL);
1541
1542         case STB_GLOBAL:
1543         case STB_WEAK:
1544                 /* Relative to Data or Function name */
1545                 symbol = ef->ddbstrtab + sym->st_name;
1546
1547                 /* Force a lookup failure if the symbol name is bogus. */
1548                 if (*symbol == 0) {
1549                         *res = 0;
1550                         return (EINVAL);
1551                 }
1552                 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1553
1554                 /*
1555                  * Cache global lookups during module relocation. The failure
1556                  * case is particularly expensive for callers, who must scan
1557                  * through the entire globals table doing strcmp(). Cache to
1558                  * avoid doing such work repeatedly.
1559                  *
1560                  * After relocation is complete, undefined globals will be
1561                  * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1562                  * above.
1563                  */
1564                 if (res1 != 0) {
1565                         sym->st_shndx = SHN_FBSD_CACHED;
1566                         sym->st_value = res1;
1567                         *res = res1;
1568                         return (0);
1569                 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1570                         sym->st_value = 0;
1571                         *res = 0;
1572                         return (0);
1573                 }
1574                 return (EINVAL);
1575
1576         default:
1577                 return (EINVAL);
1578         }
1579 }
1580
1581 static void
1582 link_elf_fix_link_set(elf_file_t ef)
1583 {
1584         static const char startn[] = "__start_";
1585         static const char stopn[] = "__stop_";
1586         Elf_Sym *sym;
1587         const char *sym_name, *linkset_name;
1588         Elf_Addr startp, stopp;
1589         Elf_Size symidx;
1590         int start, i;
1591
1592         startp = stopp = 0;
1593         for (symidx = 1 /* zero entry is special */;
1594                 symidx < ef->ddbsymcnt; symidx++) {
1595                 sym = ef->ddbsymtab + symidx;
1596                 if (sym->st_shndx != SHN_UNDEF)
1597                         continue;
1598
1599                 sym_name = ef->ddbstrtab + sym->st_name;
1600                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1601                         start = 1;
1602                         linkset_name = sym_name + sizeof(startn) - 1;
1603                 }
1604                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1605                         start = 0;
1606                         linkset_name = sym_name + sizeof(stopn) - 1;
1607                 }
1608                 else
1609                         continue;
1610
1611                 for (i = 0; i < ef->nprogtab; i++) {
1612                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1613                                 startp = (Elf_Addr)ef->progtab[i].addr;
1614                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1615                                 break;
1616                         }
1617                 }
1618                 if (i == ef->nprogtab)
1619                         continue;
1620
1621                 sym->st_value = start ? startp : stopp;
1622                 sym->st_shndx = i;
1623         }
1624 }
1625
1626 static int
1627 link_elf_reloc_local(linker_file_t lf, bool ifuncs)
1628 {
1629         elf_file_t ef = (elf_file_t)lf;
1630         const Elf_Rel *rellim;
1631         const Elf_Rel *rel;
1632         const Elf_Rela *relalim;
1633         const Elf_Rela *rela;
1634         const Elf_Sym *sym;
1635         Elf_Addr base;
1636         int i;
1637         Elf_Size symidx;
1638
1639         link_elf_fix_link_set(ef);
1640
1641         /* Perform relocations without addend if there are any: */
1642         for (i = 0; i < ef->nreltab; i++) {
1643                 rel = ef->reltab[i].rel;
1644                 if (rel == NULL) {
1645                         link_elf_error(ef->lf.filename, "lost a reltab");
1646                         return (ENOEXEC);
1647                 }
1648                 rellim = rel + ef->reltab[i].nrel;
1649                 base = findbase(ef, ef->reltab[i].sec);
1650                 if (base == 0) {
1651                         link_elf_error(ef->lf.filename, "lost base for reltab");
1652                         return (ENOEXEC);
1653                 }
1654                 for ( ; rel < rellim; rel++) {
1655                         symidx = ELF_R_SYM(rel->r_info);
1656                         if (symidx >= ef->ddbsymcnt)
1657                                 continue;
1658                         sym = ef->ddbsymtab + symidx;
1659                         /* Only do local relocs */
1660                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1661                                 continue;
1662                         if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1663                             elf_is_ifunc_reloc(rel->r_info)) != ifuncs)
1664                                 continue;
1665                         if (elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1666                             elf_obj_lookup) != 0)
1667                                 return (ENOEXEC);
1668                 }
1669         }
1670
1671         /* Perform relocations with addend if there are any: */
1672         for (i = 0; i < ef->nrelatab; i++) {
1673                 rela = ef->relatab[i].rela;
1674                 if (rela == NULL) {
1675                         link_elf_error(ef->lf.filename, "lost a relatab!");
1676                         return (ENOEXEC);
1677                 }
1678                 relalim = rela + ef->relatab[i].nrela;
1679                 base = findbase(ef, ef->relatab[i].sec);
1680                 if (base == 0) {
1681                         link_elf_error(ef->lf.filename, "lost base for reltab");
1682                         return (ENOEXEC);
1683                 }
1684                 for ( ; rela < relalim; rela++) {
1685                         symidx = ELF_R_SYM(rela->r_info);
1686                         if (symidx >= ef->ddbsymcnt)
1687                                 continue;
1688                         sym = ef->ddbsymtab + symidx;
1689                         /* Only do local relocs */
1690                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1691                                 continue;
1692                         if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1693                             elf_is_ifunc_reloc(rela->r_info)) != ifuncs)
1694                                 continue;
1695                         if (elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1696                             elf_obj_lookup) != 0)
1697                                 return (ENOEXEC);
1698                 }
1699         }
1700         return (0);
1701 }
1702
1703 static long
1704 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1705 {
1706     elf_file_t ef = (elf_file_t)lf;
1707
1708     *symtab = ef->ddbsymtab;
1709
1710     if (*symtab == NULL)
1711         return (0);
1712
1713     return (ef->ddbsymcnt);
1714 }
1715
1716 static long
1717 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1718 {
1719     elf_file_t ef = (elf_file_t)lf;
1720
1721     *strtab = ef->ddbstrtab;
1722
1723     if (*strtab == NULL)
1724         return (0);
1725
1726     return (ef->ddbstrcnt);
1727 }