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/kernel.h>
  38 #include <sys/lock.h>
  39 #include <sys/malloc.h>
  40 #include <sys/mutex.h>
  41 #include <sys/mount.h>
  42 #include <sys/proc.h>
  43 #include <sys/namei.h>
  44 #include <sys/fcntl.h>
  45 #include <sys/vnode.h>
  46 #include <sys/linker.h>
  47
  48 #include <machine/elf.h>
  49
  50 #include <net/vnet.h>
  51
  52 #include <security/mac/mac_framework.h>
  53
  54 #include <vm/vm.h>
  55 #include <vm/vm_param.h>
  56 #include <vm/vm_object.h>
  57 #include <vm/vm_kern.h>
  58 #include <vm/vm_extern.h>
  59 #include <vm/pmap.h>
  60 #include <vm/vm_map.h>
  61
  62 #include <sys/link_elf.h>
  63
  64 #ifdef DDB_CTF
  65 #include <contrib/zlib/zlib.h>
  66 #endif
  67
  68 #include "linker_if.h"
  69
  70 typedef struct {
  71         void            *addr;
  72         Elf_Off         size;
  73         int             flags;  /* Section flags. */
  74         int             sec;    /* Original section number. */
  75         char            *name;
  76 } Elf_progent;
  77
  78 typedef struct {
  79         Elf_Rel         *rel;
  80         int             nrel;
  81         int             sec;
  82 } Elf_relent;
  83
  84 typedef struct {
  85         Elf_Rela        *rela;
  86         int             nrela;
  87         int             sec;
  88 } Elf_relaent;
  89
  90 typedef struct elf_file {
  91         struct linker_file lf;          /* Common fields */
  92
  93         int             preloaded;
  94         caddr_t         address;        /* Relocation address */
  95         vm_object_t     object;         /* VM object to hold file pages */
  96         Elf_Shdr        *e_shdr;
  97
  98         Elf_progent     *progtab;
  99         u_int           nprogtab;
 100
 101         Elf_relaent     *relatab;
 102         u_int           nrelatab;
 103
 104         Elf_relent      *reltab;
 105         int             nreltab;
 106
 107         Elf_Sym         *ddbsymtab;     /* The symbol table we are using */
 108         long            ddbsymcnt;      /* Number of symbols */
 109         caddr_t         ddbstrtab;      /* String table */
 110         long            ddbstrcnt;      /* number of bytes in string table */
 111
 112         caddr_t         shstrtab;       /* Section name string table */
 113         long            shstrcnt;       /* number of bytes in string table */
 114
 115         caddr_t         ctftab;         /* CTF table */
 116         long            ctfcnt;         /* number of bytes in CTF table */
 117         caddr_t         ctfoff;         /* CTF offset table */
 118         caddr_t         typoff;         /* Type offset table */
 119         long            typlen;         /* Number of type entries. */
 120
 121 } *elf_file_t;
 122
 123 #include <kern/kern_ctf.c>
 124
 125 static int      link_elf_link_preload(linker_class_t cls,
 126                     const char *, linker_file_t *);
 127 static int      link_elf_link_preload_finish(linker_file_t);
 128 static int      link_elf_load_file(linker_class_t, const char *, linker_file_t *);
 129 static int      link_elf_lookup_symbol(linker_file_t, const char *,
 130                     c_linker_sym_t *);
 131 static int      link_elf_symbol_values(linker_file_t, c_linker_sym_t,
 132                     linker_symval_t *);
 133 static int      link_elf_search_symbol(linker_file_t, caddr_t value,
 134                     c_linker_sym_t *sym, long *diffp);
 135
 136 static void     link_elf_unload_file(linker_file_t);
 137 static int      link_elf_lookup_set(linker_file_t, const char *,
 138                     void ***, void ***, int *);
 139 static int      link_elf_each_function_name(linker_file_t,
 140                     int (*)(const char *, void *), void *);
 141 static int      link_elf_each_function_nameval(linker_file_t,
 142                                 linker_function_nameval_callback_t,
 143                                 void *);
 144 static int      link_elf_reloc_local(linker_file_t, bool);
 145 static long     link_elf_symtab_get(linker_file_t, const Elf_Sym **);
 146 static long     link_elf_strtab_get(linker_file_t, caddr_t *);
 147
 148 static int      elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps,
 149                     Elf_Addr *);
 150
 151 static kobj_method_t link_elf_methods[] = {
 152         KOBJMETHOD(linker_lookup_symbol,        link_elf_lookup_symbol),
 153         KOBJMETHOD(linker_symbol_values,        link_elf_symbol_values),
 154         KOBJMETHOD(linker_search_symbol,        link_elf_search_symbol),
 155         KOBJMETHOD(linker_unload,               link_elf_unload_file),
 156         KOBJMETHOD(linker_load_file,            link_elf_load_file),
 157         KOBJMETHOD(linker_link_preload,         link_elf_link_preload),
 158         KOBJMETHOD(linker_link_preload_finish,  link_elf_link_preload_finish),
 159         KOBJMETHOD(linker_lookup_set,           link_elf_lookup_set),
 160         KOBJMETHOD(linker_each_function_name,   link_elf_each_function_name),
 161         KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
 162         KOBJMETHOD(linker_ctf_get,              link_elf_ctf_get),
 163         KOBJMETHOD(linker_symtab_get,           link_elf_symtab_get),
 164         KOBJMETHOD(linker_strtab_get,           link_elf_strtab_get),
 165         KOBJMETHOD_END
 166 };
 167
 168 static struct linker_class link_elf_class = {
 169 #if ELF_TARG_CLASS == ELFCLASS32
 170         "elf32_obj",
 171 #else
 172         "elf64_obj",
 173 #endif
 174         link_elf_methods, sizeof(struct elf_file)
 175 };
 176
 177 static int      relocate_file(elf_file_t ef);
 178 static void     elf_obj_cleanup_globals_cache(elf_file_t);
 179
 180 static void
 181 link_elf_error(const char *filename, const char *s)
 182 {
 183         if (filename == NULL)
 184                 printf("kldload: %s\n", s);
 185         else
 186                 printf("kldload: %s: %s\n", filename, s);
 187 }
 188
 189 static void
 190 link_elf_init(void *arg)
 191 {
 192
 193         linker_add_class(&link_elf_class);
 194 }
 195 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, NULL);
 196
 197 static void
 198 link_elf_protect_range(elf_file_t ef, vm_offset_t start, vm_offset_t end,
 199     vm_prot_t prot)
 200 {
 201         int error __unused;
 202
 203         KASSERT(start <= end && start >= (vm_offset_t)ef->address &&
 204             end <= round_page((vm_offset_t)ef->address + ef->lf.size),
 205             ("link_elf_protect_range: invalid range %#jx-%#jx",
 206             (uintmax_t)start, (uintmax_t)end));
 207
 208         if (start == end)
 209                 return;
 210         if (ef->preloaded) {
 211 #ifdef __amd64__
 212                 error = pmap_change_prot(start, end - start, prot);
 213                 KASSERT(error == 0,
 214                     ("link_elf_protect_range: pmap_change_prot() returned %d",
 215                     error));
 216 #endif
 217                 return;
 218         }
 219         error = vm_map_protect(kernel_map, start, end, prot, FALSE);
 220         KASSERT(error == KERN_SUCCESS,
 221             ("link_elf_protect_range: vm_map_protect() returned %d", error));
 222 }
 223
 224 /*
 225  * Restrict permissions on linker file memory based on section flags.
 226  * Sections need not be page-aligned, so overlap within a page is possible.
 227  */
 228 static void
 229 link_elf_protect(elf_file_t ef)
 230 {
 231         vm_offset_t end, segend, segstart, start;
 232         vm_prot_t gapprot, prot, segprot;
 233         int i;
 234
 235         /*
 236          * If the file was preloaded, the last page may contain other preloaded
 237          * data which may need to be writeable.  ELF files are always
 238          * page-aligned, but other preloaded data, such as entropy or CPU
 239          * microcode may be loaded with a smaller alignment.
 240          */
 241         gapprot = ef->preloaded ? VM_PROT_RW : VM_PROT_READ;
 242
 243         start = end = (vm_offset_t)ef->address;
 244         prot = VM_PROT_READ;
 245         for (i = 0; i < ef->nprogtab; i++) {
 246                 /*
 247                  * VNET and DPCPU sections have their memory allocated by their
 248                  * respective subsystems.
 249                  */
 250                 if (ef->progtab[i].name != NULL && (
 251 #ifdef VIMAGE
 252                     strcmp(ef->progtab[i].name, VNET_SETNAME) == 0 ||
 253 #endif
 254                     strcmp(ef->progtab[i].name, DPCPU_SETNAME) == 0))
 255                         continue;
 256
 257                 segstart = trunc_page((vm_offset_t)ef->progtab[i].addr);
 258                 segend = round_page((vm_offset_t)ef->progtab[i].addr +
 259                     ef->progtab[i].size);
 260                 segprot = VM_PROT_READ;
 261                 if ((ef->progtab[i].flags & SHF_WRITE) != 0)
 262                         segprot |= VM_PROT_WRITE;
 263                 if ((ef->progtab[i].flags & SHF_EXECINSTR) != 0)
 264                         segprot |= VM_PROT_EXECUTE;
 265
 266                 if (end <= segstart) {
 267                         /*
 268                          * Case 1: there is no overlap between the previous
 269                          * segment and this one.  Apply protections to the
 270                          * previous segment, and protect the gap between the
 271                          * previous and current segments, if any.
 272                          */
 273                         link_elf_protect_range(ef, start, end, prot);
 274                         link_elf_protect_range(ef, end, segstart, gapprot);
 275
 276                         start = segstart;
 277                         end = segend;
 278                         prot = segprot;
 279                 } else if (start < segstart && end == segend) {
 280                         /*
 281                          * Case 2: the current segment is a subrange of the
 282                          * previous segment.  Apply protections to the
 283                          * non-overlapping portion of the previous segment.
 284                          */
 285                         link_elf_protect_range(ef, start, segstart, prot);
 286
 287                         start = segstart;
 288                         prot |= segprot;
 289                 } else if (end < segend) {
 290                         /*
 291                          * Case 3: there is partial overlap between the previous
 292                          * and current segments.  Apply protections to the
 293                          * non-overlapping portion of the previous segment, and
 294                          * then the overlap, which must use the union of the two
 295                          * segments' protections.
 296                          */
 297                         link_elf_protect_range(ef, start, segstart, prot);
 298                         link_elf_protect_range(ef, segstart, end,
 299                             prot | segprot);
 300                         start = end;
 301                         end = segend;
 302                         prot = segprot;
 303                 } else {
 304                         /*
 305                          * Case 4: the two segments reside in the same page.
 306                          */
 307                         prot |= segprot;
 308                 }
 309         }
 310
 311         /*
 312          * Fix up the last unprotected segment and trailing data.
 313          */
 314         link_elf_protect_range(ef, start, end, prot);
 315         link_elf_protect_range(ef, end,
 316             round_page((vm_offset_t)ef->address + ef->lf.size), gapprot);
 317 }
 318
 319 static int
 320 link_elf_link_preload(linker_class_t cls, const char *filename,
 321     linker_file_t *result)
 322 {
 323         Elf_Ehdr *hdr;
 324         Elf_Shdr *shdr;
 325         Elf_Sym *es;
 326         void *modptr, *baseptr, *sizeptr;
 327         char *type;
 328         elf_file_t ef;
 329         linker_file_t lf;
 330         Elf_Addr off;
 331         int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
 332
 333         /* Look to see if we have the file preloaded */
 334         modptr = preload_search_by_name(filename);
 335         if (modptr == NULL)
 336                 return ENOENT;
 337
 338         type = (char *)preload_search_info(modptr, MODINFO_TYPE);
 339         baseptr = preload_search_info(modptr, MODINFO_ADDR);
 340         sizeptr = preload_search_info(modptr, MODINFO_SIZE);
 341         hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
 342             MODINFOMD_ELFHDR);
 343         shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
 344             MODINFOMD_SHDR);
 345         if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
 346             " obj module") != 0 &&
 347             strcmp(type, "elf obj module") != 0)) {
 348                 return (EFTYPE);
 349         }
 350         if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
 351             shdr == NULL)
 352                 return (EINVAL);
 353
 354         lf = linker_make_file(filename, &link_elf_class);
 355         if (lf == NULL)
 356                 return (ENOMEM);
 357
 358         ef = (elf_file_t)lf;
 359         ef->preloaded = 1;
 360         ef->address = *(caddr_t *)baseptr;
 361         lf->address = *(caddr_t *)baseptr;
 362         lf->size = *(size_t *)sizeptr;
 363
 364         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
 365             hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
 366             hdr->e_ident[EI_VERSION] != EV_CURRENT ||
 367             hdr->e_version != EV_CURRENT ||
 368             hdr->e_type != ET_REL ||
 369             hdr->e_machine != ELF_TARG_MACH) {
 370                 error = EFTYPE;
 371                 goto out;
 372         }
 373         ef->e_shdr = shdr;
 374
 375         /* Scan the section header for information and table sizing. */
 376         symtabindex = -1;
 377         symstrindex = -1;
 378         for (i = 0; i < hdr->e_shnum; i++) {
 379                 switch (shdr[i].sh_type) {
 380                 case SHT_PROGBITS:
 381                 case SHT_NOBITS:
 382 #ifdef __amd64__
 383                 case SHT_X86_64_UNWIND:
 384 #endif
 385                         /* Ignore sections not loaded by the loader. */
 386                         if (shdr[i].sh_addr == 0)
 387                                 break;
 388                         ef->nprogtab++;
 389                         break;
 390                 case SHT_SYMTAB:
 391                         symtabindex = i;
 392                         symstrindex = shdr[i].sh_link;
 393                         break;
 394                 case SHT_REL:
 395                         /*
 396                          * Ignore relocation tables for sections not
 397                          * loaded by the loader.
 398                          */
 399                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 400                                 break;
 401                         ef->nreltab++;
 402                         break;
 403                 case SHT_RELA:
 404                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 405                                 break;
 406                         ef->nrelatab++;
 407                         break;
 408                 }
 409         }
 410
 411         shstrindex = hdr->e_shstrndx;
 412         if (ef->nprogtab == 0 || symstrindex < 0 ||
 413             symstrindex >= hdr->e_shnum ||
 414             shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
 415             shstrindex >= hdr->e_shnum ||
 416             shdr[shstrindex].sh_type != SHT_STRTAB) {
 417                 printf("%s: bad/missing section headers\n", filename);
 418                 error = ENOEXEC;
 419                 goto out;
 420         }
 421
 422         /* Allocate space for tracking the load chunks */
 423         if (ef->nprogtab != 0)
 424                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 425                     M_LINKER, M_WAITOK | M_ZERO);
 426         if (ef->nreltab != 0)
 427                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 428                     M_LINKER, M_WAITOK | M_ZERO);
 429         if (ef->nrelatab != 0)
 430                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 431                     M_LINKER, M_WAITOK | M_ZERO);
 432         if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
 433             (ef->nreltab != 0 && ef->reltab == NULL) ||
 434             (ef->nrelatab != 0 && ef->relatab == NULL)) {
 435                 error = ENOMEM;
 436                 goto out;
 437         }
 438
 439         /* XXX, relocate the sh_addr fields saved by the loader. */
 440         off = 0;
 441         for (i = 0; i < hdr->e_shnum; i++) {
 442                 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
 443                         off = shdr[i].sh_addr;
 444         }
 445         for (i = 0; i < hdr->e_shnum; i++) {
 446                 if (shdr[i].sh_addr != 0)
 447                         shdr[i].sh_addr = shdr[i].sh_addr - off +
 448                             (Elf_Addr)ef->address;
 449         }
 450
 451         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 452         ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
 453         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 454         ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
 455         ef->shstrcnt = shdr[shstrindex].sh_size;
 456         ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
 457
 458         /* Now fill out progtab and the relocation tables. */
 459         pb = 0;
 460         rl = 0;
 461         ra = 0;
 462         for (i = 0; i < hdr->e_shnum; i++) {
 463                 switch (shdr[i].sh_type) {
 464                 case SHT_PROGBITS:
 465                 case SHT_NOBITS:
 466 #ifdef __amd64__
 467                 case SHT_X86_64_UNWIND:
 468 #endif
 469                         if (shdr[i].sh_addr == 0)
 470                                 break;
 471                         ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
 472                         if (shdr[i].sh_type == SHT_PROGBITS)
 473                                 ef->progtab[pb].name = "<<PROGBITS>>";
 474 #ifdef __amd64__
 475                         else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
 476                                 ef->progtab[pb].name = "<<UNWIND>>";
 477 #endif
 478                         else
 479                                 ef->progtab[pb].name = "<<NOBITS>>";
 480                         ef->progtab[pb].size = shdr[i].sh_size;
 481                         ef->progtab[pb].flags = shdr[i].sh_flags;
 482                         ef->progtab[pb].sec = i;
 483                         if (ef->shstrtab && shdr[i].sh_name != 0)
 484                                 ef->progtab[pb].name =
 485                                     ef->shstrtab + shdr[i].sh_name;
 486                         if (ef->progtab[pb].name != NULL &&
 487                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
 488                                 void *dpcpu;
 489
 490                                 dpcpu = dpcpu_alloc(shdr[i].sh_size);
 491                                 if (dpcpu == NULL) {
 492                                         printf("%s: pcpu module space is out "
 493                                             "of space; cannot allocate %#jx "
 494                                             "for %s\n", __func__,
 495                                             (uintmax_t)shdr[i].sh_size,
 496                                             filename);
 497                                         error = ENOSPC;
 498                                         goto out;
 499                                 }
 500                                 memcpy(dpcpu, ef->progtab[pb].addr,
 501                                     ef->progtab[pb].size);
 502                                 dpcpu_copy(dpcpu, shdr[i].sh_size);
 503                                 ef->progtab[pb].addr = dpcpu;
 504 #ifdef VIMAGE
 505                         } else if (ef->progtab[pb].name != NULL &&
 506                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
 507                                 void *vnet_data;
 508
 509                                 vnet_data = vnet_data_alloc(shdr[i].sh_size);
 510                                 if (vnet_data == NULL) {
 511                                         printf("%s: vnet module space is out "
 512                                             "of space; cannot allocate %#jx "
 513                                             "for %s\n", __func__,
 514                                             (uintmax_t)shdr[i].sh_size,
 515                                             filename);
 516                                         error = ENOSPC;
 517                                         goto out;
 518                                 }
 519                                 memcpy(vnet_data, ef->progtab[pb].addr,
 520                                     ef->progtab[pb].size);
 521                                 vnet_data_copy(vnet_data, shdr[i].sh_size);
 522                                 ef->progtab[pb].addr = vnet_data;
 523 #endif
 524                         } else if (ef->progtab[pb].name != NULL &&
 525                             !strcmp(ef->progtab[pb].name, ".ctors")) {
 526                                 lf->ctors_addr = ef->progtab[pb].addr;
 527                                 lf->ctors_size = shdr[i].sh_size;
 528                         }
 529
 530                         /* Update all symbol values with the offset. */
 531                         for (j = 0; j < ef->ddbsymcnt; j++) {
 532                                 es = &ef->ddbsymtab[j];
 533                                 if (es->st_shndx != i)
 534                                         continue;
 535                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 536                         }
 537                         pb++;
 538                         break;
 539                 case SHT_REL:
 540                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 541                                 break;
 542                         ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
 543                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 544                         ef->reltab[rl].sec = shdr[i].sh_info;
 545                         rl++;
 546                         break;
 547                 case SHT_RELA:
 548                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 549                                 break;
 550                         ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
 551                         ef->relatab[ra].nrela =
 552                             shdr[i].sh_size / sizeof(Elf_Rela);
 553                         ef->relatab[ra].sec = shdr[i].sh_info;
 554                         ra++;
 555                         break;
 556                 }
 557         }
 558         if (pb != ef->nprogtab) {
 559                 printf("%s: lost progbits\n", filename);
 560                 error = ENOEXEC;
 561                 goto out;
 562         }
 563         if (rl != ef->nreltab) {
 564                 printf("%s: lost reltab\n", filename);
 565                 error = ENOEXEC;
 566                 goto out;
 567         }
 568         if (ra != ef->nrelatab) {
 569                 printf("%s: lost relatab\n", filename);
 570                 error = ENOEXEC;
 571                 goto out;
 572         }
 573
 574         /*
 575          * The file needs to be writeable and executable while applying
 576          * relocations.  Mapping protections are applied once relocation
 577          * processing is complete.
 578          */
 579         link_elf_protect_range(ef, (vm_offset_t)ef->address,
 580             round_page((vm_offset_t)ef->address + ef->lf.size), VM_PROT_ALL);
 581
 582         /* Local intra-module relocations */
 583         error = link_elf_reloc_local(lf, false);
 584         if (error != 0)
 585                 goto out;
 586         *result = lf;
 587         return (0);
 588
 589 out:
 590         /* preload not done this way */
 591         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 592         return (error);
 593 }
 594
 595 static void
 596 link_elf_invoke_ctors(caddr_t addr, size_t size)
 597 {
 598         void (**ctor)(void);
 599         size_t i, cnt;
 600
 601         if (addr == NULL || size == 0)
 602                 return;
 603         cnt = size / sizeof(*ctor);
 604         ctor = (void *)addr;
 605         for (i = 0; i < cnt; i++) {
 606                 if (ctor[i] != NULL)
 607                         (*ctor[i])();
 608         }
 609 }
 610
 611 static int
 612 link_elf_link_preload_finish(linker_file_t lf)
 613 {
 614         elf_file_t ef;
 615         int error;
 616
 617         ef = (elf_file_t)lf;
 618         error = relocate_file(ef);
 619         if (error)
 620                 return (error);
 621
 622         /* Notify MD code that a module is being loaded. */
 623         error = elf_cpu_load_file(lf);
 624         if (error)
 625                 return (error);
 626
 627 #if defined(__i386__) || defined(__amd64__)
 628         /* Now ifuncs. */
 629         error = link_elf_reloc_local(lf, true);
 630         if (error != 0)
 631                 return (error);
 632 #endif
 633
 634         /* Apply protections now that relocation processing is complete. */
 635         link_elf_protect(ef);
 636
 637         link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
 638         return (0);
 639 }
 640
 641 static int
 642 link_elf_load_file(linker_class_t cls, const char *filename,
 643     linker_file_t *result)
 644 {
 645         struct nameidata *nd;
 646         struct thread *td = curthread;  /* XXX */
 647         Elf_Ehdr *hdr;
 648         Elf_Shdr *shdr;
 649         Elf_Sym *es;
 650         int nbytes, i, j;
 651         vm_offset_t mapbase;
 652         size_t mapsize;
 653         int error = 0;
 654         ssize_t resid;
 655         int flags;
 656         elf_file_t ef;
 657         linker_file_t lf;
 658         int symtabindex;
 659         int symstrindex;
 660         int shstrindex;
 661         int nsym;
 662         int pb, rl, ra;
 663         int alignmask;
 664
 665         shdr = NULL;
 666         lf = NULL;
 667         mapsize = 0;
 668         hdr = NULL;
 669
 670         nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK);
 671         NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
 672         flags = FREAD;
 673         error = vn_open(nd, &flags, 0, NULL);
 674         if (error) {
 675                 free(nd, M_TEMP);
 676                 return error;
 677         }
 678         NDFREE(nd, NDF_ONLY_PNBUF);
 679         if (nd->ni_vp->v_type != VREG) {
 680                 error = ENOEXEC;
 681                 goto out;
 682         }
 683 #ifdef MAC
 684         error = mac_kld_check_load(td->td_ucred, nd->ni_vp);
 685         if (error) {
 686                 goto out;
 687         }
 688 #endif
 689
 690         /* Read the elf header from the file. */
 691         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
 692         error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0,
 693             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 694             &resid, td);
 695         if (error)
 696                 goto out;
 697         if (resid != 0){
 698                 error = ENOEXEC;
 699                 goto out;
 700         }
 701
 702         if (!IS_ELF(*hdr)) {
 703                 error = ENOEXEC;
 704                 goto out;
 705         }
 706
 707         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
 708             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
 709                 link_elf_error(filename, "Unsupported file layout");
 710                 error = ENOEXEC;
 711                 goto out;
 712         }
 713         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
 714             || hdr->e_version != EV_CURRENT) {
 715                 link_elf_error(filename, "Unsupported file version");
 716                 error = ENOEXEC;
 717                 goto out;
 718         }
 719         if (hdr->e_type != ET_REL) {
 720                 error = ENOSYS;
 721                 goto out;
 722         }
 723         if (hdr->e_machine != ELF_TARG_MACH) {
 724                 link_elf_error(filename, "Unsupported machine");
 725                 error = ENOEXEC;
 726                 goto out;
 727         }
 728
 729         lf = linker_make_file(filename, &link_elf_class);
 730         if (!lf) {
 731                 error = ENOMEM;
 732                 goto out;
 733         }
 734         ef = (elf_file_t) lf;
 735         ef->nprogtab = 0;
 736         ef->e_shdr = 0;
 737         ef->nreltab = 0;
 738         ef->nrelatab = 0;
 739
 740         /* Allocate and read in the section header */
 741         nbytes = hdr->e_shnum * hdr->e_shentsize;
 742         if (nbytes == 0 || hdr->e_shoff == 0 ||
 743             hdr->e_shentsize != sizeof(Elf_Shdr)) {
 744                 error = ENOEXEC;
 745                 goto out;
 746         }
 747         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
 748         ef->e_shdr = shdr;
 749         error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes,
 750             hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
 751             NOCRED, &resid, td);
 752         if (error)
 753                 goto out;
 754         if (resid) {
 755                 error = ENOEXEC;
 756                 goto out;
 757         }
 758
 759         /* Scan the section header for information and table sizing. */
 760         nsym = 0;
 761         symtabindex = -1;
 762         symstrindex = -1;
 763         for (i = 0; i < hdr->e_shnum; i++) {
 764                 if (shdr[i].sh_size == 0)
 765                         continue;
 766                 switch (shdr[i].sh_type) {
 767                 case SHT_PROGBITS:
 768                 case SHT_NOBITS:
 769 #ifdef __amd64__
 770                 case SHT_X86_64_UNWIND:
 771 #endif
 772                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 773                                 break;
 774                         ef->nprogtab++;
 775                         break;
 776                 case SHT_SYMTAB:
 777                         nsym++;
 778                         symtabindex = i;
 779                         symstrindex = shdr[i].sh_link;
 780                         break;
 781                 case SHT_REL:
 782                         /*
 783                          * Ignore relocation tables for unallocated
 784                          * sections.
 785                          */
 786                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
 787                                 break;
 788                         ef->nreltab++;
 789                         break;
 790                 case SHT_RELA:
 791                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
 792                                 break;
 793                         ef->nrelatab++;
 794                         break;
 795                 case SHT_STRTAB:
 796                         break;
 797                 }
 798         }
 799         if (ef->nprogtab == 0) {
 800                 link_elf_error(filename, "file has no contents");
 801                 error = ENOEXEC;
 802                 goto out;
 803         }
 804         if (nsym != 1) {
 805                 /* Only allow one symbol table for now */
 806                 link_elf_error(filename,
 807                     "file must have exactly one symbol table");
 808                 error = ENOEXEC;
 809                 goto out;
 810         }
 811         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
 812             shdr[symstrindex].sh_type != SHT_STRTAB) {
 813                 link_elf_error(filename, "file has invalid symbol strings");
 814                 error = ENOEXEC;
 815                 goto out;
 816         }
 817
 818         /* Allocate space for tracking the load chunks */
 819         if (ef->nprogtab != 0)
 820                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 821                     M_LINKER, M_WAITOK | M_ZERO);
 822         if (ef->nreltab != 0)
 823                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 824                     M_LINKER, M_WAITOK | M_ZERO);
 825         if (ef->nrelatab != 0)
 826                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 827                     M_LINKER, M_WAITOK | M_ZERO);
 828
 829         if (symtabindex == -1) {
 830                 link_elf_error(filename, "lost symbol table index");
 831                 error = ENOEXEC;
 832                 goto out;
 833         }
 834         /* Allocate space for and load the symbol table */
 835         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 836         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
 837         error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab,
 838             shdr[symtabindex].sh_size, shdr[symtabindex].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         /* Allocate space for and load the symbol strings */
 849         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 850         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
 851         error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab,
 852             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
 853             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 854             &resid, td);
 855         if (error)
 856                 goto out;
 857         if (resid != 0){
 858                 error = EINVAL;
 859                 goto out;
 860         }
 861
 862         /* Do we have a string table for the section names?  */
 863         shstrindex = -1;
 864         if (hdr->e_shstrndx != 0 &&
 865             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
 866                 shstrindex = hdr->e_shstrndx;
 867                 ef->shstrcnt = shdr[shstrindex].sh_size;
 868                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
 869                     M_WAITOK);
 870                 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab,
 871                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
 872                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 873                     &resid, td);
 874                 if (error)
 875                         goto out;
 876                 if (resid != 0){
 877                         error = EINVAL;
 878                         goto out;
 879                 }
 880         }
 881
 882         /* Size up code/data(progbits) and bss(nobits). */
 883         alignmask = 0;
 884         for (i = 0; i < hdr->e_shnum; i++) {
 885                 if (shdr[i].sh_size == 0)
 886                         continue;
 887                 switch (shdr[i].sh_type) {
 888                 case SHT_PROGBITS:
 889                 case SHT_NOBITS:
 890 #ifdef __amd64__
 891                 case SHT_X86_64_UNWIND:
 892 #endif
 893                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 894                                 break;
 895                         alignmask = shdr[i].sh_addralign - 1;
 896                         mapsize += alignmask;
 897                         mapsize &= ~alignmask;
 898                         mapsize += shdr[i].sh_size;
 899                         break;
 900                 }
 901         }
 902
 903         /*
 904          * We know how much space we need for the text/data/bss/etc.
 905          * This stuff needs to be in a single chunk so that profiling etc
 906          * can get the bounds and gdb can associate offsets with modules
 907          */
 908         ef->object = vm_object_allocate(OBJT_PHYS, atop(round_page(mapsize)));
 909         if (ef->object == NULL) {
 910                 error = ENOMEM;
 911                 goto out;
 912         }
 913
 914         /*
 915          * In order to satisfy amd64's architectural requirements on the
 916          * location of code and data in the kernel's address space, request a
 917          * mapping that is above the kernel.
 918          *
 919          * Protections will be restricted once relocations are applied.
 920          */
 921 #ifdef __amd64__
 922         mapbase = KERNBASE;
 923 #else
 924         mapbase = VM_MIN_KERNEL_ADDRESS;
 925 #endif
 926         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
 927             round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
 928             VM_PROT_ALL, 0);
 929         if (error != KERN_SUCCESS) {
 930                 vm_object_deallocate(ef->object);
 931                 ef->object = NULL;
 932                 error = ENOMEM;
 933                 goto out;
 934         }
 935
 936         /* Wire the pages */
 937         error = vm_map_wire(kernel_map, mapbase,
 938             mapbase + round_page(mapsize),
 939             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 940         if (error != KERN_SUCCESS) {
 941                 error = ENOMEM;
 942                 goto out;
 943         }
 944
 945         /* Inform the kld system about the situation */
 946         lf->address = ef->address = (caddr_t)mapbase;
 947         lf->size = mapsize;
 948
 949         /*
 950          * Now load code/data(progbits), zero bss(nobits), allocate space for
 951          * and load relocs
 952          */
 953         pb = 0;
 954         rl = 0;
 955         ra = 0;
 956         alignmask = 0;
 957         for (i = 0; i < hdr->e_shnum; i++) {
 958                 if (shdr[i].sh_size == 0)
 959                         continue;
 960                 switch (shdr[i].sh_type) {
 961                 case SHT_PROGBITS:
 962                 case SHT_NOBITS:
 963 #ifdef __amd64__
 964                 case SHT_X86_64_UNWIND:
 965 #endif
 966                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 967                                 break;
 968                         alignmask = shdr[i].sh_addralign - 1;
 969                         mapbase += alignmask;
 970                         mapbase &= ~alignmask;
 971                         if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
 972                                 ef->progtab[pb].name =
 973                                     ef->shstrtab + shdr[i].sh_name;
 974                                 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
 975                                         lf->ctors_addr = (caddr_t)mapbase;
 976                                         lf->ctors_size = shdr[i].sh_size;
 977                                 }
 978                         } else if (shdr[i].sh_type == SHT_PROGBITS)
 979                                 ef->progtab[pb].name = "<<PROGBITS>>";
 980 #ifdef __amd64__
 981                         else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
 982                                 ef->progtab[pb].name = "<<UNWIND>>";
 983 #endif
 984                         else
 985                                 ef->progtab[pb].name = "<<NOBITS>>";
 986                         if (ef->progtab[pb].name != NULL &&
 987                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
 988                                 ef->progtab[pb].addr =
 989                                     dpcpu_alloc(shdr[i].sh_size);
 990                                 if (ef->progtab[pb].addr == NULL) {
 991                                         printf("%s: pcpu 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 #ifdef VIMAGE
 999                         else if (ef->progtab[pb].name != NULL &&
1000                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
1001                                 ef->progtab[pb].addr =
1002                                     vnet_data_alloc(shdr[i].sh_size);
1003                                 if (ef->progtab[pb].addr == NULL) {
1004                                         printf("%s: vnet module space is out "
1005                                             "of space; cannot allocate %#jx "
1006                                             "for %s\n", __func__,
1007                                             (uintmax_t)shdr[i].sh_size,
1008                                             filename);
1009                                 }
1010                         }
1011 #endif
1012                         else
1013                                 ef->progtab[pb].addr =
1014                                     (void *)(uintptr_t)mapbase;
1015                         if (ef->progtab[pb].addr == NULL) {
1016                                 error = ENOSPC;
1017                                 goto out;
1018                         }
1019                         ef->progtab[pb].size = shdr[i].sh_size;
1020                         ef->progtab[pb].flags = shdr[i].sh_flags;
1021                         ef->progtab[pb].sec = i;
1022                         if (shdr[i].sh_type == SHT_PROGBITS
1023 #ifdef __amd64__
1024                             || shdr[i].sh_type == SHT_X86_64_UNWIND
1025 #endif
1026                             ) {
1027                                 error = vn_rdwr(UIO_READ, nd->ni_vp,
1028                                     ef->progtab[pb].addr,
1029                                     shdr[i].sh_size, shdr[i].sh_offset,
1030                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
1031                                     NOCRED, &resid, td);
1032                                 if (error)
1033                                         goto out;
1034                                 if (resid != 0){
1035                                         error = EINVAL;
1036                                         goto out;
1037                                 }
1038                                 /* Initialize the per-cpu or vnet area. */
1039                                 if (ef->progtab[pb].addr != (void *)mapbase &&
1040                                     !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
1041                                         dpcpu_copy(ef->progtab[pb].addr,
1042                                             shdr[i].sh_size);
1043 #ifdef VIMAGE
1044                                 else if (ef->progtab[pb].addr !=
1045                                     (void *)mapbase &&
1046                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
1047                                         vnet_data_copy(ef->progtab[pb].addr,
1048                                             shdr[i].sh_size);
1049 #endif
1050                         } else
1051                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
1052
1053                         /* Update all symbol values with the offset. */
1054                         for (j = 0; j < ef->ddbsymcnt; j++) {
1055                                 es = &ef->ddbsymtab[j];
1056                                 if (es->st_shndx != i)
1057                                         continue;
1058                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
1059                         }
1060                         mapbase += shdr[i].sh_size;
1061                         pb++;
1062                         break;
1063                 case SHT_REL:
1064                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
1065                                 break;
1066                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
1067                             M_WAITOK);
1068                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
1069                         ef->reltab[rl].sec = shdr[i].sh_info;
1070                         error = vn_rdwr(UIO_READ, nd->ni_vp,
1071                             (void *)ef->reltab[rl].rel,
1072                             shdr[i].sh_size, shdr[i].sh_offset,
1073                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1074                             &resid, td);
1075                         if (error)
1076                                 goto out;
1077                         if (resid != 0){
1078                                 error = EINVAL;
1079                                 goto out;
1080                         }
1081                         rl++;
1082                         break;
1083                 case SHT_RELA:
1084                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
1085                                 break;
1086                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
1087                             M_WAITOK);
1088                         ef->relatab[ra].nrela =
1089                             shdr[i].sh_size / sizeof(Elf_Rela);
1090                         ef->relatab[ra].sec = shdr[i].sh_info;
1091                         error = vn_rdwr(UIO_READ, nd->ni_vp,
1092                             (void *)ef->relatab[ra].rela,
1093                             shdr[i].sh_size, shdr[i].sh_offset,
1094                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1095                             &resid, td);
1096                         if (error)
1097                                 goto out;
1098                         if (resid != 0){
1099                                 error = EINVAL;
1100                                 goto out;
1101                         }
1102                         ra++;
1103                         break;
1104                 }
1105         }
1106         if (pb != ef->nprogtab) {
1107                 link_elf_error(filename, "lost progbits");
1108                 error = ENOEXEC;
1109                 goto out;
1110         }
1111         if (rl != ef->nreltab) {
1112                 link_elf_error(filename, "lost reltab");
1113                 error = ENOEXEC;
1114                 goto out;
1115         }
1116         if (ra != ef->nrelatab) {
1117                 link_elf_error(filename, "lost relatab");
1118                 error = ENOEXEC;
1119                 goto out;
1120         }
1121         if (mapbase != (vm_offset_t)ef->address + mapsize) {
1122                 printf(
1123                     "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
1124                     filename != NULL ? filename : "<none>",
1125                     (u_long)mapbase, ef->address, (u_long)mapsize,
1126                     (u_long)(vm_offset_t)ef->address + mapsize);
1127                 error = ENOMEM;
1128                 goto out;
1129         }
1130
1131         /* Local intra-module relocations */
1132         error = link_elf_reloc_local(lf, false);
1133         if (error != 0)
1134                 goto out;
1135
1136         /* Pull in dependencies */
1137         VOP_UNLOCK(nd->ni_vp);
1138         error = linker_load_dependencies(lf);
1139         vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY);
1140         if (error)
1141                 goto out;
1142
1143         /* External relocations */
1144         error = relocate_file(ef);
1145         if (error)
1146                 goto out;
1147
1148         /* Notify MD code that a module is being loaded. */
1149         error = elf_cpu_load_file(lf);
1150         if (error)
1151                 goto out;
1152
1153 #if defined(__i386__) || defined(__amd64__)
1154         /* Now ifuncs. */
1155         error = link_elf_reloc_local(lf, true);
1156         if (error != 0)
1157                 goto out;
1158 #endif
1159
1160         link_elf_protect(ef);
1161         link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
1162         *result = lf;
1163
1164 out:
1165         VOP_UNLOCK(nd->ni_vp);
1166         vn_close(nd->ni_vp, FREAD, td->td_ucred, td);
1167         free(nd, M_TEMP);
1168         if (error && lf)
1169                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1170         free(hdr, M_LINKER);
1171
1172         return error;
1173 }
1174
1175 static void
1176 link_elf_unload_file(linker_file_t file)
1177 {
1178         elf_file_t ef = (elf_file_t) file;
1179         u_int i;
1180
1181         /* Notify MD code that a module is being unloaded. */
1182         elf_cpu_unload_file(file);
1183
1184         if (ef->progtab) {
1185                 for (i = 0; i < ef->nprogtab; i++) {
1186                         if (ef->progtab[i].size == 0)
1187                                 continue;
1188                         if (ef->progtab[i].name == NULL)
1189                                 continue;
1190                         if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
1191                                 dpcpu_free(ef->progtab[i].addr,
1192                                     ef->progtab[i].size);
1193 #ifdef VIMAGE
1194                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
1195                                 vnet_data_free(ef->progtab[i].addr,
1196                                     ef->progtab[i].size);
1197 #endif
1198                 }
1199         }
1200         if (ef->preloaded) {
1201                 free(ef->reltab, M_LINKER);
1202                 free(ef->relatab, M_LINKER);
1203                 free(ef->progtab, M_LINKER);
1204                 free(ef->ctftab, M_LINKER);
1205                 free(ef->ctfoff, M_LINKER);
1206                 free(ef->typoff, M_LINKER);
1207                 if (file->pathname != NULL)
1208                         preload_delete_name(file->pathname);
1209                 return;
1210         }
1211
1212         for (i = 0; i < ef->nreltab; i++)
1213                 free(ef->reltab[i].rel, M_LINKER);
1214         for (i = 0; i < ef->nrelatab; i++)
1215                 free(ef->relatab[i].rela, M_LINKER);
1216         free(ef->reltab, M_LINKER);
1217         free(ef->relatab, M_LINKER);
1218         free(ef->progtab, M_LINKER);
1219
1220         if (ef->object != NULL)
1221                 vm_map_remove(kernel_map, (vm_offset_t)ef->address,
1222                     (vm_offset_t)ef->address + ptoa(ef->object->size));
1223         free(ef->e_shdr, M_LINKER);
1224         free(ef->ddbsymtab, M_LINKER);
1225         free(ef->ddbstrtab, M_LINKER);
1226         free(ef->shstrtab, M_LINKER);
1227         free(ef->ctftab, M_LINKER);
1228         free(ef->ctfoff, M_LINKER);
1229         free(ef->typoff, M_LINKER);
1230 }
1231
1232 static const char *
1233 symbol_name(elf_file_t ef, Elf_Size r_info)
1234 {
1235         const Elf_Sym *ref;
1236
1237         if (ELF_R_SYM(r_info)) {
1238                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1239                 return ef->ddbstrtab + ref->st_name;
1240         } else
1241                 return NULL;
1242 }
1243
1244 static Elf_Addr
1245 findbase(elf_file_t ef, int sec)
1246 {
1247         int i;
1248         Elf_Addr base = 0;
1249
1250         for (i = 0; i < ef->nprogtab; i++) {
1251                 if (sec == ef->progtab[i].sec) {
1252                         base = (Elf_Addr)ef->progtab[i].addr;
1253                         break;
1254                 }
1255         }
1256         return base;
1257 }
1258
1259 static int
1260 relocate_file(elf_file_t ef)
1261 {
1262         const Elf_Rel *rellim;
1263         const Elf_Rel *rel;
1264         const Elf_Rela *relalim;
1265         const Elf_Rela *rela;
1266         const char *symname;
1267         const Elf_Sym *sym;
1268         int i;
1269         Elf_Size symidx;
1270         Elf_Addr base;
1271
1272         /* Perform relocations without addend if there are any: */
1273         for (i = 0; i < ef->nreltab; i++) {
1274                 rel = ef->reltab[i].rel;
1275                 if (rel == NULL) {
1276                         link_elf_error(ef->lf.filename, "lost a reltab!");
1277                         return (ENOEXEC);
1278                 }
1279                 rellim = rel + ef->reltab[i].nrel;
1280                 base = findbase(ef, ef->reltab[i].sec);
1281                 if (base == 0) {
1282                         link_elf_error(ef->lf.filename, "lost base for reltab");
1283                         return (ENOEXEC);
1284                 }
1285                 for ( ; rel < rellim; rel++) {
1286                         symidx = ELF_R_SYM(rel->r_info);
1287                         if (symidx >= ef->ddbsymcnt)
1288                                 continue;
1289                         sym = ef->ddbsymtab + symidx;
1290                         /* Local relocs are already done */
1291                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1292                                 continue;
1293                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1294                             elf_obj_lookup)) {
1295                                 symname = symbol_name(ef, rel->r_info);
1296                                 printf("link_elf_obj: symbol %s undefined\n",
1297                                     symname);
1298                                 return (ENOENT);
1299                         }
1300                 }
1301         }
1302
1303         /* Perform relocations with addend if there are any: */
1304         for (i = 0; i < ef->nrelatab; i++) {
1305                 rela = ef->relatab[i].rela;
1306                 if (rela == NULL) {
1307                         link_elf_error(ef->lf.filename, "lost a relatab!");
1308                         return (ENOEXEC);
1309                 }
1310                 relalim = rela + ef->relatab[i].nrela;
1311                 base = findbase(ef, ef->relatab[i].sec);
1312                 if (base == 0) {
1313                         link_elf_error(ef->lf.filename,
1314                             "lost base for relatab");
1315                         return (ENOEXEC);
1316                 }
1317                 for ( ; rela < relalim; rela++) {
1318                         symidx = ELF_R_SYM(rela->r_info);
1319                         if (symidx >= ef->ddbsymcnt)
1320                                 continue;
1321                         sym = ef->ddbsymtab + symidx;
1322                         /* Local relocs are already done */
1323                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1324                                 continue;
1325                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1326                             elf_obj_lookup)) {
1327                                 symname = symbol_name(ef, rela->r_info);
1328                                 printf("link_elf_obj: symbol %s undefined\n",
1329                                     symname);
1330                                 return (ENOENT);
1331                         }
1332                 }
1333         }
1334
1335         /*
1336          * Only clean SHN_FBSD_CACHED for successful return.  If we
1337          * modified symbol table for the object but found an
1338          * unresolved symbol, there is no reason to roll back.
1339          */
1340         elf_obj_cleanup_globals_cache(ef);
1341
1342         return (0);
1343 }
1344
1345 static int
1346 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1347 {
1348         elf_file_t ef = (elf_file_t) lf;
1349         const Elf_Sym *symp;
1350         const char *strp;
1351         int i;
1352
1353         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1354                 strp = ef->ddbstrtab + symp->st_name;
1355                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1356                         *sym = (c_linker_sym_t) symp;
1357                         return 0;
1358                 }
1359         }
1360         return ENOENT;
1361 }
1362
1363 static int
1364 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1365     linker_symval_t *symval)
1366 {
1367         elf_file_t ef;
1368         const Elf_Sym *es;
1369         caddr_t val;
1370
1371         ef = (elf_file_t) lf;
1372         es = (const Elf_Sym*) sym;
1373         val = (caddr_t)es->st_value;
1374         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1375                 symval->name = ef->ddbstrtab + es->st_name;
1376                 val = (caddr_t)es->st_value;
1377                 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1378                         val = ((caddr_t (*)(void))val)();
1379                 symval->value = val;
1380                 symval->size = es->st_size;
1381                 return 0;
1382         }
1383         return ENOENT;
1384 }
1385
1386 static int
1387 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1388     c_linker_sym_t *sym, long *diffp)
1389 {
1390         elf_file_t ef = (elf_file_t) lf;
1391         u_long off = (uintptr_t) (void *) value;
1392         u_long diff = off;
1393         u_long st_value;
1394         const Elf_Sym *es;
1395         const Elf_Sym *best = NULL;
1396         int i;
1397
1398         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1399                 if (es->st_name == 0)
1400                         continue;
1401                 st_value = es->st_value;
1402                 if (off >= st_value) {
1403                         if (off - st_value < diff) {
1404                                 diff = off - st_value;
1405                                 best = es;
1406                                 if (diff == 0)
1407                                         break;
1408                         } else if (off - st_value == diff) {
1409                                 best = es;
1410                         }
1411                 }
1412         }
1413         if (best == NULL)
1414                 *diffp = off;
1415         else
1416                 *diffp = diff;
1417         *sym = (c_linker_sym_t) best;
1418
1419         return 0;
1420 }
1421
1422 /*
1423  * Look up a linker set on an ELF system.
1424  */
1425 static int
1426 link_elf_lookup_set(linker_file_t lf, const char *name,
1427     void ***startp, void ***stopp, int *countp)
1428 {
1429         elf_file_t ef = (elf_file_t)lf;
1430         void **start, **stop;
1431         int i, count;
1432
1433         /* Relative to section number */
1434         for (i = 0; i < ef->nprogtab; i++) {
1435                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1436                     strcmp(ef->progtab[i].name + 4, name) == 0) {
1437                         start  = (void **)ef->progtab[i].addr;
1438                         stop = (void **)((char *)ef->progtab[i].addr +
1439                             ef->progtab[i].size);
1440                         count = stop - start;
1441                         if (startp)
1442                                 *startp = start;
1443                         if (stopp)
1444                                 *stopp = stop;
1445                         if (countp)
1446                                 *countp = count;
1447                         return (0);
1448                 }
1449         }
1450         return (ESRCH);
1451 }
1452
1453 static int
1454 link_elf_each_function_name(linker_file_t file,
1455     int (*callback)(const char *, void *), void *opaque)
1456 {
1457         elf_file_t ef = (elf_file_t)file;
1458         const Elf_Sym *symp;
1459         int i, error;
1460
1461         /* Exhaustive search */
1462         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1463                 if (symp->st_value != 0 &&
1464                     (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1465                     ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1466                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
1467                         if (error)
1468                                 return (error);
1469                 }
1470         }
1471         return (0);
1472 }
1473
1474 static int
1475 link_elf_each_function_nameval(linker_file_t file,
1476     linker_function_nameval_callback_t callback, void *opaque)
1477 {
1478         linker_symval_t symval;
1479         elf_file_t ef = (elf_file_t)file;
1480         const Elf_Sym* symp;
1481         int i, error;
1482
1483         /* Exhaustive search */
1484         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1485                 if (symp->st_value != 0 &&
1486                     (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1487                     ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1488                         error = link_elf_symbol_values(file,
1489                             (c_linker_sym_t)symp, &symval);
1490                         if (error)
1491                                 return (error);
1492                         error = callback(file, i, &symval, opaque);
1493                         if (error)
1494                                 return (error);
1495                 }
1496         }
1497         return (0);
1498 }
1499
1500 static void
1501 elf_obj_cleanup_globals_cache(elf_file_t ef)
1502 {
1503         Elf_Sym *sym;
1504         Elf_Size i;
1505
1506         for (i = 0; i < ef->ddbsymcnt; i++) {
1507                 sym = ef->ddbsymtab + i;
1508                 if (sym->st_shndx == SHN_FBSD_CACHED) {
1509                         sym->st_shndx = SHN_UNDEF;
1510                         sym->st_value = 0;
1511                 }
1512         }
1513 }
1514
1515 /*
1516  * Symbol lookup function that can be used when the symbol index is known (ie
1517  * in relocations). It uses the symbol index instead of doing a fully fledged
1518  * hash table based lookup when such is valid. For example for local symbols.
1519  * This is not only more efficient, it's also more correct. It's not always
1520  * the case that the symbol can be found through the hash table.
1521  */
1522 static int
1523 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1524 {
1525         elf_file_t ef = (elf_file_t)lf;
1526         Elf_Sym *sym;
1527         const char *symbol;
1528         Elf_Addr res1;
1529
1530         /* Don't even try to lookup the symbol if the index is bogus. */
1531         if (symidx >= ef->ddbsymcnt) {
1532                 *res = 0;
1533                 return (EINVAL);
1534         }
1535
1536         sym = ef->ddbsymtab + symidx;
1537
1538         /* Quick answer if there is a definition included. */
1539         if (sym->st_shndx != SHN_UNDEF) {
1540                 res1 = (Elf_Addr)sym->st_value;
1541                 if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC)
1542                         res1 = ((Elf_Addr (*)(void))res1)();
1543                 *res = res1;
1544                 return (0);
1545         }
1546
1547         /* If we get here, then it is undefined and needs a lookup. */
1548         switch (ELF_ST_BIND(sym->st_info)) {
1549         case STB_LOCAL:
1550                 /* Local, but undefined? huh? */
1551                 *res = 0;
1552                 return (EINVAL);
1553
1554         case STB_GLOBAL:
1555         case STB_WEAK:
1556                 /* Relative to Data or Function name */
1557                 symbol = ef->ddbstrtab + sym->st_name;
1558
1559                 /* Force a lookup failure if the symbol name is bogus. */
1560                 if (*symbol == 0) {
1561                         *res = 0;
1562                         return (EINVAL);
1563                 }
1564                 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1565
1566                 /*
1567                  * Cache global lookups during module relocation. The failure
1568                  * case is particularly expensive for callers, who must scan
1569                  * through the entire globals table doing strcmp(). Cache to
1570                  * avoid doing such work repeatedly.
1571                  *
1572                  * After relocation is complete, undefined globals will be
1573                  * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1574                  * above.
1575                  */
1576                 if (res1 != 0) {
1577                         sym->st_shndx = SHN_FBSD_CACHED;
1578                         sym->st_value = res1;
1579                         *res = res1;
1580                         return (0);
1581                 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1582                         sym->st_value = 0;
1583                         *res = 0;
1584                         return (0);
1585                 }
1586                 return (EINVAL);
1587
1588         default:
1589                 return (EINVAL);
1590         }
1591 }
1592
1593 static void
1594 link_elf_fix_link_set(elf_file_t ef)
1595 {
1596         static const char startn[] = "__start_";
1597         static const char stopn[] = "__stop_";
1598         Elf_Sym *sym;
1599         const char *sym_name, *linkset_name;
1600         Elf_Addr startp, stopp;
1601         Elf_Size symidx;
1602         int start, i;
1603
1604         startp = stopp = 0;
1605         for (symidx = 1 /* zero entry is special */;
1606                 symidx < ef->ddbsymcnt; symidx++) {
1607                 sym = ef->ddbsymtab + symidx;
1608                 if (sym->st_shndx != SHN_UNDEF)
1609                         continue;
1610
1611                 sym_name = ef->ddbstrtab + sym->st_name;
1612                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1613                         start = 1;
1614                         linkset_name = sym_name + sizeof(startn) - 1;
1615                 }
1616                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1617                         start = 0;
1618                         linkset_name = sym_name + sizeof(stopn) - 1;
1619                 }
1620                 else
1621                         continue;
1622
1623                 for (i = 0; i < ef->nprogtab; i++) {
1624                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1625                                 startp = (Elf_Addr)ef->progtab[i].addr;
1626                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1627                                 break;
1628                         }
1629                 }
1630                 if (i == ef->nprogtab)
1631                         continue;
1632
1633                 sym->st_value = start ? startp : stopp;
1634                 sym->st_shndx = i;
1635         }
1636 }
1637
1638 static int
1639 link_elf_reloc_local(linker_file_t lf, bool ifuncs)
1640 {
1641         elf_file_t ef = (elf_file_t)lf;
1642         const Elf_Rel *rellim;
1643         const Elf_Rel *rel;
1644         const Elf_Rela *relalim;
1645         const Elf_Rela *rela;
1646         const Elf_Sym *sym;
1647         Elf_Addr base;
1648         int i;
1649         Elf_Size symidx;
1650
1651         link_elf_fix_link_set(ef);
1652
1653         /* Perform relocations without addend if there are any: */
1654         for (i = 0; i < ef->nreltab; i++) {
1655                 rel = ef->reltab[i].rel;
1656                 if (rel == NULL) {
1657                         link_elf_error(ef->lf.filename, "lost a reltab");
1658                         return (ENOEXEC);
1659                 }
1660                 rellim = rel + ef->reltab[i].nrel;
1661                 base = findbase(ef, ef->reltab[i].sec);
1662                 if (base == 0) {
1663                         link_elf_error(ef->lf.filename, "lost base for reltab");
1664                         return (ENOEXEC);
1665                 }
1666                 for ( ; rel < rellim; rel++) {
1667                         symidx = ELF_R_SYM(rel->r_info);
1668                         if (symidx >= ef->ddbsymcnt)
1669                                 continue;
1670                         sym = ef->ddbsymtab + symidx;
1671                         /* Only do local relocs */
1672                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1673                                 continue;
1674                         if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1675                             elf_is_ifunc_reloc(rel->r_info)) == ifuncs)
1676                                 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1677                                     elf_obj_lookup);
1678                 }
1679         }
1680
1681         /* Perform relocations with addend if there are any: */
1682         for (i = 0; i < ef->nrelatab; i++) {
1683                 rela = ef->relatab[i].rela;
1684                 if (rela == NULL) {
1685                         link_elf_error(ef->lf.filename, "lost a relatab!");
1686                         return (ENOEXEC);
1687                 }
1688                 relalim = rela + ef->relatab[i].nrela;
1689                 base = findbase(ef, ef->relatab[i].sec);
1690                 if (base == 0) {
1691                         link_elf_error(ef->lf.filename, "lost base for reltab");
1692                         return (ENOEXEC);
1693                 }
1694                 for ( ; rela < relalim; rela++) {
1695                         symidx = ELF_R_SYM(rela->r_info);
1696                         if (symidx >= ef->ddbsymcnt)
1697                                 continue;
1698                         sym = ef->ddbsymtab + symidx;
1699                         /* Only do local relocs */
1700                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1701                                 continue;
1702                         if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1703                             elf_is_ifunc_reloc(rela->r_info)) == ifuncs)
1704                                 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1705                                     elf_obj_lookup);
1706                 }
1707         }
1708         return (0);
1709 }
1710
1711 static long
1712 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1713 {
1714     elf_file_t ef = (elf_file_t)lf;
1715
1716     *symtab = ef->ddbsymtab;
1717
1718     if (*symtab == NULL)
1719         return (0);
1720
1721     return (ef->ddbsymcnt);
1722 }
1723
1724 static long
1725 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1726 {
1727     elf_file_t ef = (elf_file_t)lf;
1728
1729     *strtab = ef->ddbstrtab;
1730
1731     if (*strtab == NULL)
1732         return (0);
1733
1734     return (ef->ddbstrcnt);
1735 }