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 <contrib/zlib/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 typedef struct elf_file {
  94         struct linker_file lf;          /* Common fields */
  95
  96         int             preloaded;
  97         caddr_t         address;        /* Relocation address */
  98         vm_object_t     object;         /* VM object to hold file pages */
  99         Elf_Shdr        *e_shdr;
 100
 101         Elf_progent     *progtab;
 102         u_int           nprogtab;
 103
 104         Elf_relaent     *relatab;
 105         u_int           nrelatab;
 106
 107         Elf_relent      *reltab;
 108         int             nreltab;
 109
 110         Elf_Sym         *ddbsymtab;     /* The symbol table we are using */
 111         long            ddbsymcnt;      /* Number of symbols */
 112         caddr_t         ddbstrtab;      /* String table */
 113         long            ddbstrcnt;      /* number of bytes in string table */
 114
 115         caddr_t         shstrtab;       /* Section name string table */
 116         long            shstrcnt;       /* number of bytes in string table */
 117
 118         caddr_t         ctftab;         /* CTF table */
 119         long            ctfcnt;         /* number of bytes in CTF table */
 120         caddr_t         ctfoff;         /* CTF offset table */
 121         caddr_t         typoff;         /* Type offset table */
 122         long            typlen;         /* Number of type entries. */
 123
 124 } *elf_file_t;
 125
 126 #include <kern/kern_ctf.c>
 127
 128 static int      link_elf_link_preload(linker_class_t cls,
 129                     const char *, linker_file_t *);
 130 static int      link_elf_link_preload_finish(linker_file_t);
 131 static int      link_elf_load_file(linker_class_t, const char *, linker_file_t *);
 132 static int      link_elf_lookup_symbol(linker_file_t, const char *,
 133                     c_linker_sym_t *);
 134 static int      link_elf_symbol_values(linker_file_t, c_linker_sym_t,
 135                     linker_symval_t *);
 136 static int      link_elf_search_symbol(linker_file_t, caddr_t value,
 137                     c_linker_sym_t *sym, long *diffp);
 138
 139 static void     link_elf_unload_file(linker_file_t);
 140 static int      link_elf_lookup_set(linker_file_t, const char *,
 141                     void ***, void ***, int *);
 142 static int      link_elf_each_function_name(linker_file_t,
 143                     int (*)(const char *, void *), void *);
 144 static int      link_elf_each_function_nameval(linker_file_t,
 145                                 linker_function_nameval_callback_t,
 146                                 void *);
 147 static int      link_elf_reloc_local(linker_file_t, bool);
 148 static long     link_elf_symtab_get(linker_file_t, const Elf_Sym **);
 149 static long     link_elf_strtab_get(linker_file_t, caddr_t *);
 150
 151 static int      elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps,
 152                     Elf_Addr *);
 153
 154 static kobj_method_t link_elf_methods[] = {
 155         KOBJMETHOD(linker_lookup_symbol,        link_elf_lookup_symbol),
 156         KOBJMETHOD(linker_symbol_values,        link_elf_symbol_values),
 157         KOBJMETHOD(linker_search_symbol,        link_elf_search_symbol),
 158         KOBJMETHOD(linker_unload,               link_elf_unload_file),
 159         KOBJMETHOD(linker_load_file,            link_elf_load_file),
 160         KOBJMETHOD(linker_link_preload,         link_elf_link_preload),
 161         KOBJMETHOD(linker_link_preload_finish,  link_elf_link_preload_finish),
 162         KOBJMETHOD(linker_lookup_set,           link_elf_lookup_set),
 163         KOBJMETHOD(linker_each_function_name,   link_elf_each_function_name),
 164         KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
 165         KOBJMETHOD(linker_ctf_get,              link_elf_ctf_get),
 166         KOBJMETHOD(linker_symtab_get,           link_elf_symtab_get),
 167         KOBJMETHOD(linker_strtab_get,           link_elf_strtab_get),
 168         KOBJMETHOD_END
 169 };
 170
 171 static struct linker_class link_elf_class = {
 172 #if ELF_TARG_CLASS == ELFCLASS32
 173         "elf32_obj",
 174 #else
 175         "elf64_obj",
 176 #endif
 177         link_elf_methods, sizeof(struct elf_file)
 178 };
 179
 180 static int      relocate_file(elf_file_t ef);
 181 static void     elf_obj_cleanup_globals_cache(elf_file_t);
 182
 183 static void
 184 link_elf_error(const char *filename, const char *s)
 185 {
 186         if (filename == NULL)
 187                 printf("kldload: %s\n", s);
 188         else
 189                 printf("kldload: %s: %s\n", filename, s);
 190 }
 191
 192 static void
 193 link_elf_init(void *arg)
 194 {
 195
 196         linker_add_class(&link_elf_class);
 197 }
 198 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, NULL);
 199
 200 static void
 201 link_elf_protect_range(elf_file_t ef, vm_offset_t start, vm_offset_t end,
 202     vm_prot_t prot)
 203 {
 204         int error __unused;
 205
 206         KASSERT(start <= end && start >= (vm_offset_t)ef->address &&
 207             end <= round_page((vm_offset_t)ef->address + ef->lf.size),
 208             ("link_elf_protect_range: invalid range %#jx-%#jx",
 209             (uintmax_t)start, (uintmax_t)end));
 210
 211         if (start == end)
 212                 return;
 213         if (ef->preloaded) {
 214 #ifdef __amd64__
 215                 error = pmap_change_prot(start, end - start, prot);
 216                 KASSERT(error == 0,
 217                     ("link_elf_protect_range: pmap_change_prot() returned %d",
 218                     error));
 219 #endif
 220                 return;
 221         }
 222         error = vm_map_protect(kernel_map, start, end, prot, 0,
 223             VM_MAP_PROTECT_SET_PROT);
 224         KASSERT(error == KERN_SUCCESS,
 225             ("link_elf_protect_range: vm_map_protect() returned %d", error));
 226 }
 227
 228 /*
 229  * Restrict permissions on linker file memory based on section flags.
 230  * Sections need not be page-aligned, so overlap within a page is possible.
 231  */
 232 static void
 233 link_elf_protect(elf_file_t ef)
 234 {
 235         vm_offset_t end, segend, segstart, start;
 236         vm_prot_t gapprot, prot, segprot;
 237         int i;
 238
 239         /*
 240          * If the file was preloaded, the last page may contain other preloaded
 241          * data which may need to be writeable.  ELF files are always
 242          * page-aligned, but other preloaded data, such as entropy or CPU
 243          * microcode may be loaded with a smaller alignment.
 244          */
 245         gapprot = ef->preloaded ? VM_PROT_RW : VM_PROT_READ;
 246
 247         start = end = (vm_offset_t)ef->address;
 248         prot = VM_PROT_READ;
 249         for (i = 0; i < ef->nprogtab; i++) {
 250                 /*
 251                  * VNET and DPCPU sections have their memory allocated by their
 252                  * respective subsystems.
 253                  */
 254                 if (ef->progtab[i].name != NULL && (
 255 #ifdef VIMAGE
 256                     strcmp(ef->progtab[i].name, VNET_SETNAME) == 0 ||
 257 #endif
 258                     strcmp(ef->progtab[i].name, DPCPU_SETNAME) == 0))
 259                         continue;
 260
 261                 segstart = trunc_page((vm_offset_t)ef->progtab[i].addr);
 262                 segend = round_page((vm_offset_t)ef->progtab[i].addr +
 263                     ef->progtab[i].size);
 264                 segprot = VM_PROT_READ;
 265                 if ((ef->progtab[i].flags & SHF_WRITE) != 0)
 266                         segprot |= VM_PROT_WRITE;
 267                 if ((ef->progtab[i].flags & SHF_EXECINSTR) != 0)
 268                         segprot |= VM_PROT_EXECUTE;
 269
 270                 if (end <= segstart) {
 271                         /*
 272                          * Case 1: there is no overlap between the previous
 273                          * segment and this one.  Apply protections to the
 274                          * previous segment, and protect the gap between the
 275                          * previous and current segments, if any.
 276                          */
 277                         link_elf_protect_range(ef, start, end, prot);
 278                         link_elf_protect_range(ef, end, segstart, gapprot);
 279
 280                         start = segstart;
 281                         end = segend;
 282                         prot = segprot;
 283                 } else if (start < segstart && end == segend) {
 284                         /*
 285                          * Case 2: the current segment is a subrange of the
 286                          * previous segment.  Apply protections to the
 287                          * non-overlapping portion of the previous segment.
 288                          */
 289                         link_elf_protect_range(ef, start, segstart, prot);
 290
 291                         start = segstart;
 292                         prot |= segprot;
 293                 } else if (end < segend) {
 294                         /*
 295                          * Case 3: there is partial overlap between the previous
 296                          * and current segments.  Apply protections to the
 297                          * non-overlapping portion of the previous segment, and
 298                          * then the overlap, which must use the union of the two
 299                          * segments' protections.
 300                          */
 301                         link_elf_protect_range(ef, start, segstart, prot);
 302                         link_elf_protect_range(ef, segstart, end,
 303                             prot | segprot);
 304                         start = end;
 305                         end = segend;
 306                         prot = segprot;
 307                 } else {
 308                         /*
 309                          * Case 4: the two segments reside in the same page.
 310                          */
 311                         prot |= segprot;
 312                 }
 313         }
 314
 315         /*
 316          * Fix up the last unprotected segment and trailing data.
 317          */
 318         link_elf_protect_range(ef, start, end, prot);
 319         link_elf_protect_range(ef, end,
 320             round_page((vm_offset_t)ef->address + ef->lf.size), gapprot);
 321 }
 322
 323 static int
 324 link_elf_link_preload(linker_class_t cls, const char *filename,
 325     linker_file_t *result)
 326 {
 327         Elf_Ehdr *hdr;
 328         Elf_Shdr *shdr;
 329         Elf_Sym *es;
 330         void *modptr, *baseptr, *sizeptr;
 331         char *type;
 332         elf_file_t ef;
 333         linker_file_t lf;
 334         Elf_Addr off;
 335         int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
 336
 337         /* Look to see if we have the file preloaded */
 338         modptr = preload_search_by_name(filename);
 339         if (modptr == NULL)
 340                 return ENOENT;
 341
 342         type = (char *)preload_search_info(modptr, MODINFO_TYPE);
 343         baseptr = preload_search_info(modptr, MODINFO_ADDR);
 344         sizeptr = preload_search_info(modptr, MODINFO_SIZE);
 345         hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
 346             MODINFOMD_ELFHDR);
 347         shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
 348             MODINFOMD_SHDR);
 349         if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
 350             " obj module") != 0 &&
 351             strcmp(type, "elf obj module") != 0)) {
 352                 return (EFTYPE);
 353         }
 354         if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
 355             shdr == NULL)
 356                 return (EINVAL);
 357
 358         lf = linker_make_file(filename, &link_elf_class);
 359         if (lf == NULL)
 360                 return (ENOMEM);
 361
 362         ef = (elf_file_t)lf;
 363         ef->preloaded = 1;
 364         ef->address = *(caddr_t *)baseptr;
 365         lf->address = *(caddr_t *)baseptr;
 366         lf->size = *(size_t *)sizeptr;
 367
 368         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
 369             hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
 370             hdr->e_ident[EI_VERSION] != EV_CURRENT ||
 371             hdr->e_version != EV_CURRENT ||
 372             hdr->e_type != ET_REL ||
 373             hdr->e_machine != ELF_TARG_MACH) {
 374                 error = EFTYPE;
 375                 goto out;
 376         }
 377         ef->e_shdr = shdr;
 378
 379         /* Scan the section header for information and table sizing. */
 380         symtabindex = -1;
 381         symstrindex = -1;
 382         for (i = 0; i < hdr->e_shnum; i++) {
 383                 switch (shdr[i].sh_type) {
 384                 case SHT_PROGBITS:
 385                 case SHT_NOBITS:
 386 #ifdef __amd64__
 387                 case SHT_X86_64_UNWIND:
 388 #endif
 389                 case SHT_INIT_ARRAY:
 390                 case SHT_FINI_ARRAY:
 391                         /* Ignore sections not loaded by the loader. */
 392                         if (shdr[i].sh_addr == 0)
 393                                 break;
 394                         ef->nprogtab++;
 395                         break;
 396                 case SHT_SYMTAB:
 397                         symtabindex = i;
 398                         symstrindex = shdr[i].sh_link;
 399                         break;
 400                 case SHT_REL:
 401                         /*
 402                          * Ignore relocation tables for sections not
 403                          * loaded by the loader.
 404                          */
 405                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 406                                 break;
 407                         ef->nreltab++;
 408                         break;
 409                 case SHT_RELA:
 410                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 411                                 break;
 412                         ef->nrelatab++;
 413                         break;
 414                 }
 415         }
 416
 417         shstrindex = hdr->e_shstrndx;
 418         if (ef->nprogtab == 0 || symstrindex < 0 ||
 419             symstrindex >= hdr->e_shnum ||
 420             shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
 421             shstrindex >= hdr->e_shnum ||
 422             shdr[shstrindex].sh_type != SHT_STRTAB) {
 423                 printf("%s: bad/missing section headers\n", filename);
 424                 error = ENOEXEC;
 425                 goto out;
 426         }
 427
 428         /* Allocate space for tracking the load chunks */
 429         if (ef->nprogtab != 0)
 430                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 431                     M_LINKER, M_WAITOK | M_ZERO);
 432         if (ef->nreltab != 0)
 433                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 434                     M_LINKER, M_WAITOK | M_ZERO);
 435         if (ef->nrelatab != 0)
 436                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 437                     M_LINKER, M_WAITOK | M_ZERO);
 438         if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
 439             (ef->nreltab != 0 && ef->reltab == NULL) ||
 440             (ef->nrelatab != 0 && ef->relatab == NULL)) {
 441                 error = ENOMEM;
 442                 goto out;
 443         }
 444
 445         /* XXX, relocate the sh_addr fields saved by the loader. */
 446         off = 0;
 447         for (i = 0; i < hdr->e_shnum; i++) {
 448                 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
 449                         off = shdr[i].sh_addr;
 450         }
 451         for (i = 0; i < hdr->e_shnum; i++) {
 452                 if (shdr[i].sh_addr != 0)
 453                         shdr[i].sh_addr = shdr[i].sh_addr - off +
 454                             (Elf_Addr)ef->address;
 455         }
 456
 457         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 458         ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
 459         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 460         ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
 461         ef->shstrcnt = shdr[shstrindex].sh_size;
 462         ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
 463
 464         /* Now fill out progtab and the relocation tables. */
 465         pb = 0;
 466         rl = 0;
 467         ra = 0;
 468         for (i = 0; i < hdr->e_shnum; i++) {
 469                 switch (shdr[i].sh_type) {
 470                 case SHT_PROGBITS:
 471                 case SHT_NOBITS:
 472 #ifdef __amd64__
 473                 case SHT_X86_64_UNWIND:
 474 #endif
 475                 case SHT_INIT_ARRAY:
 476                 case SHT_FINI_ARRAY:
 477                         if (shdr[i].sh_addr == 0)
 478                                 break;
 479                         ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
 480                         if (shdr[i].sh_type == SHT_PROGBITS)
 481                                 ef->progtab[pb].name = "<<PROGBITS>>";
 482 #ifdef __amd64__
 483                         else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
 484                                 ef->progtab[pb].name = "<<UNWIND>>";
 485 #endif
 486                         else if (shdr[i].sh_type == SHT_INIT_ARRAY)
 487                                 ef->progtab[pb].name = "<<INIT_ARRAY>>";
 488                         else if (shdr[i].sh_type == SHT_FINI_ARRAY)
 489                                 ef->progtab[pb].name = "<<FINI_ARRAY>>";
 490                         else
 491                                 ef->progtab[pb].name = "<<NOBITS>>";
 492                         ef->progtab[pb].size = shdr[i].sh_size;
 493                         ef->progtab[pb].flags = shdr[i].sh_flags;
 494                         ef->progtab[pb].sec = i;
 495                         if (ef->shstrtab && shdr[i].sh_name != 0)
 496                                 ef->progtab[pb].name =
 497                                     ef->shstrtab + shdr[i].sh_name;
 498                         if (ef->progtab[pb].name != NULL &&
 499                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
 500                                 void *dpcpu;
 501
 502                                 dpcpu = dpcpu_alloc(shdr[i].sh_size);
 503                                 if (dpcpu == NULL) {
 504                                         printf("%s: pcpu module space is out "
 505                                             "of space; cannot allocate %#jx "
 506                                             "for %s\n", __func__,
 507                                             (uintmax_t)shdr[i].sh_size,
 508                                             filename);
 509                                         error = ENOSPC;
 510                                         goto out;
 511                                 }
 512                                 memcpy(dpcpu, ef->progtab[pb].addr,
 513                                     ef->progtab[pb].size);
 514                                 dpcpu_copy(dpcpu, shdr[i].sh_size);
 515                                 ef->progtab[pb].addr = dpcpu;
 516 #ifdef VIMAGE
 517                         } else if (ef->progtab[pb].name != NULL &&
 518                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
 519                                 void *vnet_data;
 520
 521                                 vnet_data = vnet_data_alloc(shdr[i].sh_size);
 522                                 if (vnet_data == NULL) {
 523                                         printf("%s: vnet module space is out "
 524                                             "of space; cannot allocate %#jx "
 525                                             "for %s\n", __func__,
 526                                             (uintmax_t)shdr[i].sh_size,
 527                                             filename);
 528                                         error = ENOSPC;
 529                                         goto out;
 530                                 }
 531                                 memcpy(vnet_data, ef->progtab[pb].addr,
 532                                     ef->progtab[pb].size);
 533                                 vnet_data_copy(vnet_data, shdr[i].sh_size);
 534                                 ef->progtab[pb].addr = vnet_data;
 535 #endif
 536                         } else if ((ef->progtab[pb].name != NULL &&
 537                             strcmp(ef->progtab[pb].name, ".ctors") == 0) ||
 538                             shdr[i].sh_type == SHT_INIT_ARRAY) {
 539                                 if (lf->ctors_addr != 0) {
 540                                         printf(
 541                                     "%s: multiple ctor sections in %s\n",
 542                                             __func__, filename);
 543                                 } else {
 544                                         lf->ctors_addr = ef->progtab[pb].addr;
 545                                         lf->ctors_size = shdr[i].sh_size;
 546                                 }
 547                         }
 548
 549                         /* Update all symbol values with the offset. */
 550                         for (j = 0; j < ef->ddbsymcnt; j++) {
 551                                 es = &ef->ddbsymtab[j];
 552                                 if (es->st_shndx != i)
 553                                         continue;
 554                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 555                         }
 556                         pb++;
 557                         break;
 558                 case SHT_REL:
 559                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 560                                 break;
 561                         ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
 562                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 563                         ef->reltab[rl].sec = shdr[i].sh_info;
 564                         rl++;
 565                         break;
 566                 case SHT_RELA:
 567                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 568                                 break;
 569                         ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
 570                         ef->relatab[ra].nrela =
 571                             shdr[i].sh_size / sizeof(Elf_Rela);
 572                         ef->relatab[ra].sec = shdr[i].sh_info;
 573                         ra++;
 574                         break;
 575                 }
 576         }
 577         if (pb != ef->nprogtab) {
 578                 printf("%s: lost progbits\n", filename);
 579                 error = ENOEXEC;
 580                 goto out;
 581         }
 582         if (rl != ef->nreltab) {
 583                 printf("%s: lost reltab\n", filename);
 584                 error = ENOEXEC;
 585                 goto out;
 586         }
 587         if (ra != ef->nrelatab) {
 588                 printf("%s: lost relatab\n", filename);
 589                 error = ENOEXEC;
 590                 goto out;
 591         }
 592
 593         /*
 594          * The file needs to be writeable and executable while applying
 595          * relocations.  Mapping protections are applied once relocation
 596          * processing is complete.
 597          */
 598         link_elf_protect_range(ef, (vm_offset_t)ef->address,
 599             round_page((vm_offset_t)ef->address + ef->lf.size), VM_PROT_ALL);
 600
 601         /* Local intra-module relocations */
 602         error = link_elf_reloc_local(lf, false);
 603         if (error != 0)
 604                 goto out;
 605         *result = lf;
 606         return (0);
 607
 608 out:
 609         /* preload not done this way */
 610         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 611         return (error);
 612 }
 613
 614 static void
 615 link_elf_invoke_ctors(caddr_t addr, size_t size)
 616 {
 617         void (**ctor)(void);
 618         size_t i, cnt;
 619
 620         if (addr == NULL || size == 0)
 621                 return;
 622         cnt = size / sizeof(*ctor);
 623         ctor = (void *)addr;
 624         for (i = 0; i < cnt; i++) {
 625                 if (ctor[i] != NULL)
 626                         (*ctor[i])();
 627         }
 628 }
 629
 630 static int
 631 link_elf_link_preload_finish(linker_file_t lf)
 632 {
 633         elf_file_t ef;
 634         int error;
 635
 636         ef = (elf_file_t)lf;
 637         error = relocate_file(ef);
 638         if (error)
 639                 return (error);
 640
 641         /* Notify MD code that a module is being loaded. */
 642         error = elf_cpu_load_file(lf);
 643         if (error)
 644                 return (error);
 645
 646 #if defined(__i386__) || defined(__amd64__)
 647         /* Now ifuncs. */
 648         error = link_elf_reloc_local(lf, true);
 649         if (error != 0)
 650                 return (error);
 651 #endif
 652
 653         /* Apply protections now that relocation processing is complete. */
 654         link_elf_protect(ef);
 655
 656         link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
 657         return (0);
 658 }
 659
 660 static int
 661 link_elf_load_file(linker_class_t cls, const char *filename,
 662     linker_file_t *result)
 663 {
 664         struct nameidata *nd;
 665         struct thread *td = curthread;  /* XXX */
 666         Elf_Ehdr *hdr;
 667         Elf_Shdr *shdr;
 668         Elf_Sym *es;
 669         int nbytes, i, j;
 670         vm_offset_t mapbase;
 671         size_t mapsize;
 672         int error = 0;
 673         ssize_t resid;
 674         int flags;
 675         elf_file_t ef;
 676         linker_file_t lf;
 677         int symtabindex;
 678         int symstrindex;
 679         int shstrindex;
 680         int nsym;
 681         int pb, rl, ra;
 682         int alignmask;
 683
 684         shdr = NULL;
 685         lf = NULL;
 686         mapsize = 0;
 687         hdr = NULL;
 688
 689         nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK);
 690         NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
 691         flags = FREAD;
 692         error = vn_open(nd, &flags, 0, NULL);
 693         if (error) {
 694                 free(nd, M_TEMP);
 695                 return error;
 696         }
 697         NDFREE(nd, NDF_ONLY_PNBUF);
 698         if (nd->ni_vp->v_type != VREG) {
 699                 error = ENOEXEC;
 700                 goto out;
 701         }
 702 #ifdef MAC
 703         error = mac_kld_check_load(td->td_ucred, nd->ni_vp);
 704         if (error) {
 705                 goto out;
 706         }
 707 #endif
 708
 709         /* Read the elf header from the file. */
 710         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
 711         error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0,
 712             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 713             &resid, td);
 714         if (error)
 715                 goto out;
 716         if (resid != 0){
 717                 error = ENOEXEC;
 718                 goto out;
 719         }
 720
 721         if (!IS_ELF(*hdr)) {
 722                 error = ENOEXEC;
 723                 goto out;
 724         }
 725
 726         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
 727             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
 728                 link_elf_error(filename, "Unsupported file layout");
 729                 error = ENOEXEC;
 730                 goto out;
 731         }
 732         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
 733             || hdr->e_version != EV_CURRENT) {
 734                 link_elf_error(filename, "Unsupported file version");
 735                 error = ENOEXEC;
 736                 goto out;
 737         }
 738         if (hdr->e_type != ET_REL) {
 739                 error = ENOSYS;
 740                 goto out;
 741         }
 742         if (hdr->e_machine != ELF_TARG_MACH) {
 743                 link_elf_error(filename, "Unsupported machine");
 744                 error = ENOEXEC;
 745                 goto out;
 746         }
 747
 748         lf = linker_make_file(filename, &link_elf_class);
 749         if (!lf) {
 750                 error = ENOMEM;
 751                 goto out;
 752         }
 753         ef = (elf_file_t) lf;
 754         ef->nprogtab = 0;
 755         ef->e_shdr = 0;
 756         ef->nreltab = 0;
 757         ef->nrelatab = 0;
 758
 759         /* Allocate and read in the section header */
 760         nbytes = hdr->e_shnum * hdr->e_shentsize;
 761         if (nbytes == 0 || hdr->e_shoff == 0 ||
 762             hdr->e_shentsize != sizeof(Elf_Shdr)) {
 763                 error = ENOEXEC;
 764                 goto out;
 765         }
 766         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
 767         ef->e_shdr = shdr;
 768         error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes,
 769             hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
 770             NOCRED, &resid, td);
 771         if (error)
 772                 goto out;
 773         if (resid) {
 774                 error = ENOEXEC;
 775                 goto out;
 776         }
 777
 778         /* Scan the section header for information and table sizing. */
 779         nsym = 0;
 780         symtabindex = -1;
 781         symstrindex = -1;
 782         for (i = 0; i < hdr->e_shnum; i++) {
 783                 if (shdr[i].sh_size == 0)
 784                         continue;
 785                 switch (shdr[i].sh_type) {
 786                 case SHT_PROGBITS:
 787                 case SHT_NOBITS:
 788 #ifdef __amd64__
 789                 case SHT_X86_64_UNWIND:
 790 #endif
 791                 case SHT_INIT_ARRAY:
 792                 case SHT_FINI_ARRAY:
 793                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 794                                 break;
 795                         ef->nprogtab++;
 796                         break;
 797                 case SHT_SYMTAB:
 798                         nsym++;
 799                         symtabindex = i;
 800                         symstrindex = shdr[i].sh_link;
 801                         break;
 802                 case SHT_REL:
 803                         /*
 804                          * Ignore relocation tables for unallocated
 805                          * sections.
 806                          */
 807                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
 808                                 break;
 809                         ef->nreltab++;
 810                         break;
 811                 case SHT_RELA:
 812                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
 813                                 break;
 814                         ef->nrelatab++;
 815                         break;
 816                 case SHT_STRTAB:
 817                         break;
 818                 }
 819         }
 820         if (ef->nprogtab == 0) {
 821                 link_elf_error(filename, "file has no contents");
 822                 error = ENOEXEC;
 823                 goto out;
 824         }
 825         if (nsym != 1) {
 826                 /* Only allow one symbol table for now */
 827                 link_elf_error(filename,
 828                     "file must have exactly one symbol table");
 829                 error = ENOEXEC;
 830                 goto out;
 831         }
 832         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
 833             shdr[symstrindex].sh_type != SHT_STRTAB) {
 834                 link_elf_error(filename, "file has invalid symbol strings");
 835                 error = ENOEXEC;
 836                 goto out;
 837         }
 838
 839         /* Allocate space for tracking the load chunks */
 840         if (ef->nprogtab != 0)
 841                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 842                     M_LINKER, M_WAITOK | M_ZERO);
 843         if (ef->nreltab != 0)
 844                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 845                     M_LINKER, M_WAITOK | M_ZERO);
 846         if (ef->nrelatab != 0)
 847                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 848                     M_LINKER, M_WAITOK | M_ZERO);
 849
 850         if (symtabindex == -1) {
 851                 link_elf_error(filename, "lost symbol table index");
 852                 error = ENOEXEC;
 853                 goto out;
 854         }
 855         /* Allocate space for and load the symbol table */
 856         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 857         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
 858         error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab,
 859             shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
 860             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 861             &resid, td);
 862         if (error)
 863                 goto out;
 864         if (resid != 0){
 865                 error = EINVAL;
 866                 goto out;
 867         }
 868
 869         /* Allocate space for and load the symbol strings */
 870         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 871         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
 872         error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab,
 873             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
 874             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 875             &resid, td);
 876         if (error)
 877                 goto out;
 878         if (resid != 0){
 879                 error = EINVAL;
 880                 goto out;
 881         }
 882
 883         /* Do we have a string table for the section names?  */
 884         shstrindex = -1;
 885         if (hdr->e_shstrndx != 0 &&
 886             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
 887                 shstrindex = hdr->e_shstrndx;
 888                 ef->shstrcnt = shdr[shstrindex].sh_size;
 889                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
 890                     M_WAITOK);
 891                 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab,
 892                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
 893                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 894                     &resid, td);
 895                 if (error)
 896                         goto out;
 897                 if (resid != 0){
 898                         error = EINVAL;
 899                         goto out;
 900                 }
 901         }
 902
 903         /* Size up code/data(progbits) and bss(nobits). */
 904         alignmask = 0;
 905         for (i = 0; i < hdr->e_shnum; i++) {
 906                 if (shdr[i].sh_size == 0)
 907                         continue;
 908                 switch (shdr[i].sh_type) {
 909                 case SHT_PROGBITS:
 910                 case SHT_NOBITS:
 911 #ifdef __amd64__
 912                 case SHT_X86_64_UNWIND:
 913 #endif
 914                 case SHT_INIT_ARRAY:
 915                 case SHT_FINI_ARRAY:
 916                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 917                                 break;
 918                         alignmask = shdr[i].sh_addralign - 1;
 919                         mapsize += alignmask;
 920                         mapsize &= ~alignmask;
 921                         mapsize += shdr[i].sh_size;
 922                         break;
 923                 }
 924         }
 925
 926         /*
 927          * We know how much space we need for the text/data/bss/etc.
 928          * This stuff needs to be in a single chunk so that profiling etc
 929          * can get the bounds and gdb can associate offsets with modules
 930          */
 931         ef->object = vm_pager_allocate(OBJT_PHYS, NULL, round_page(mapsize),
 932             VM_PROT_ALL, 0, thread0.td_ucred);
 933         if (ef->object == NULL) {
 934                 error = ENOMEM;
 935                 goto out;
 936         }
 937 #if VM_NRESERVLEVEL > 0
 938         vm_object_color(ef->object, 0);
 939 #endif
 940
 941         /*
 942          * In order to satisfy amd64's architectural requirements on the
 943          * location of code and data in the kernel's address space, request a
 944          * mapping that is above the kernel.
 945          *
 946          * Protections will be restricted once relocations are applied.
 947          */
 948 #ifdef __amd64__
 949         mapbase = KERNBASE;
 950 #else
 951         mapbase = VM_MIN_KERNEL_ADDRESS;
 952 #endif
 953         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
 954             round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
 955             VM_PROT_ALL, 0);
 956         if (error != KERN_SUCCESS) {
 957                 vm_object_deallocate(ef->object);
 958                 ef->object = NULL;
 959                 error = ENOMEM;
 960                 goto out;
 961         }
 962
 963         /* Wire the pages */
 964         error = vm_map_wire(kernel_map, mapbase,
 965             mapbase + round_page(mapsize),
 966             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 967         if (error != KERN_SUCCESS) {
 968                 error = ENOMEM;
 969                 goto out;
 970         }
 971
 972         /* Inform the kld system about the situation */
 973         lf->address = ef->address = (caddr_t)mapbase;
 974         lf->size = mapsize;
 975
 976         /*
 977          * Now load code/data(progbits), zero bss(nobits), allocate space for
 978          * and load relocs
 979          */
 980         pb = 0;
 981         rl = 0;
 982         ra = 0;
 983         alignmask = 0;
 984         for (i = 0; i < hdr->e_shnum; i++) {
 985                 if (shdr[i].sh_size == 0)
 986                         continue;
 987                 switch (shdr[i].sh_type) {
 988                 case SHT_PROGBITS:
 989                 case SHT_NOBITS:
 990 #ifdef __amd64__
 991                 case SHT_X86_64_UNWIND:
 992 #endif
 993                 case SHT_INIT_ARRAY:
 994                 case SHT_FINI_ARRAY:
 995                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 996                                 break;
 997                         alignmask = shdr[i].sh_addralign - 1;
 998                         mapbase += alignmask;
 999                         mapbase &= ~alignmask;
1000                         if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
1001                                 ef->progtab[pb].name =
1002                                     ef->shstrtab + shdr[i].sh_name;
1003                                 if (!strcmp(ef->progtab[pb].name, ".ctors") ||
1004                                     shdr[i].sh_type == SHT_INIT_ARRAY) {
1005                                         if (lf->ctors_addr != 0) {
1006                                                 printf(
1007                                     "%s: multiple ctor sections in %s\n",
1008                                                     __func__, filename);
1009                                         } else {
1010                                                 lf->ctors_addr =
1011                                                     (caddr_t)mapbase;
1012                                                 lf->ctors_size =
1013                                                     shdr[i].sh_size;
1014                                         }
1015                                 }
1016                         } else if (shdr[i].sh_type == SHT_PROGBITS)
1017                                 ef->progtab[pb].name = "<<PROGBITS>>";
1018 #ifdef __amd64__
1019                         else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
1020                                 ef->progtab[pb].name = "<<UNWIND>>";
1021 #endif
1022                         else
1023                                 ef->progtab[pb].name = "<<NOBITS>>";
1024                         if (ef->progtab[pb].name != NULL &&
1025                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
1026                                 ef->progtab[pb].addr =
1027                                     dpcpu_alloc(shdr[i].sh_size);
1028                                 if (ef->progtab[pb].addr == NULL) {
1029                                         printf("%s: pcpu module space is out "
1030                                             "of space; cannot allocate %#jx "
1031                                             "for %s\n", __func__,
1032                                             (uintmax_t)shdr[i].sh_size,
1033                                             filename);
1034                                 }
1035                         }
1036 #ifdef VIMAGE
1037                         else if (ef->progtab[pb].name != NULL &&
1038                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
1039                                 ef->progtab[pb].addr =
1040                                     vnet_data_alloc(shdr[i].sh_size);
1041                                 if (ef->progtab[pb].addr == NULL) {
1042                                         printf("%s: vnet module space is out "
1043                                             "of space; cannot allocate %#jx "
1044                                             "for %s\n", __func__,
1045                                             (uintmax_t)shdr[i].sh_size,
1046                                             filename);
1047                                 }
1048                         }
1049 #endif
1050                         else
1051                                 ef->progtab[pb].addr =
1052                                     (void *)(uintptr_t)mapbase;
1053                         if (ef->progtab[pb].addr == NULL) {
1054                                 error = ENOSPC;
1055                                 goto out;
1056                         }
1057                         ef->progtab[pb].size = shdr[i].sh_size;
1058                         ef->progtab[pb].flags = shdr[i].sh_flags;
1059                         ef->progtab[pb].sec = i;
1060                         if (shdr[i].sh_type == SHT_PROGBITS
1061 #ifdef __amd64__
1062                             || shdr[i].sh_type == SHT_X86_64_UNWIND
1063 #endif
1064                             ) {
1065                                 error = vn_rdwr(UIO_READ, nd->ni_vp,
1066                                     ef->progtab[pb].addr,
1067                                     shdr[i].sh_size, shdr[i].sh_offset,
1068                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
1069                                     NOCRED, &resid, td);
1070                                 if (error)
1071                                         goto out;
1072                                 if (resid != 0){
1073                                         error = EINVAL;
1074                                         goto out;
1075                                 }
1076                                 /* Initialize the per-cpu or vnet area. */
1077                                 if (ef->progtab[pb].addr != (void *)mapbase &&
1078                                     !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
1079                                         dpcpu_copy(ef->progtab[pb].addr,
1080                                             shdr[i].sh_size);
1081 #ifdef VIMAGE
1082                                 else if (ef->progtab[pb].addr !=
1083                                     (void *)mapbase &&
1084                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
1085                                         vnet_data_copy(ef->progtab[pb].addr,
1086                                             shdr[i].sh_size);
1087 #endif
1088                         } else
1089                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
1090
1091                         /* Update all symbol values with the offset. */
1092                         for (j = 0; j < ef->ddbsymcnt; j++) {
1093                                 es = &ef->ddbsymtab[j];
1094                                 if (es->st_shndx != i)
1095                                         continue;
1096                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
1097                         }
1098                         mapbase += shdr[i].sh_size;
1099                         pb++;
1100                         break;
1101                 case SHT_REL:
1102                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
1103                                 break;
1104                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
1105                             M_WAITOK);
1106                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
1107                         ef->reltab[rl].sec = shdr[i].sh_info;
1108                         error = vn_rdwr(UIO_READ, nd->ni_vp,
1109                             (void *)ef->reltab[rl].rel,
1110                             shdr[i].sh_size, shdr[i].sh_offset,
1111                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1112                             &resid, td);
1113                         if (error)
1114                                 goto out;
1115                         if (resid != 0){
1116                                 error = EINVAL;
1117                                 goto out;
1118                         }
1119                         rl++;
1120                         break;
1121                 case SHT_RELA:
1122                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
1123                                 break;
1124                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
1125                             M_WAITOK);
1126                         ef->relatab[ra].nrela =
1127                             shdr[i].sh_size / sizeof(Elf_Rela);
1128                         ef->relatab[ra].sec = shdr[i].sh_info;
1129                         error = vn_rdwr(UIO_READ, nd->ni_vp,
1130                             (void *)ef->relatab[ra].rela,
1131                             shdr[i].sh_size, shdr[i].sh_offset,
1132                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1133                             &resid, td);
1134                         if (error)
1135                                 goto out;
1136                         if (resid != 0){
1137                                 error = EINVAL;
1138                                 goto out;
1139                         }
1140                         ra++;
1141                         break;
1142                 }
1143         }
1144         if (pb != ef->nprogtab) {
1145                 link_elf_error(filename, "lost progbits");
1146                 error = ENOEXEC;
1147                 goto out;
1148         }
1149         if (rl != ef->nreltab) {
1150                 link_elf_error(filename, "lost reltab");
1151                 error = ENOEXEC;
1152                 goto out;
1153         }
1154         if (ra != ef->nrelatab) {
1155                 link_elf_error(filename, "lost relatab");
1156                 error = ENOEXEC;
1157                 goto out;
1158         }
1159         if (mapbase != (vm_offset_t)ef->address + mapsize) {
1160                 printf(
1161                     "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
1162                     filename != NULL ? filename : "<none>",
1163                     (u_long)mapbase, ef->address, (u_long)mapsize,
1164                     (u_long)(vm_offset_t)ef->address + mapsize);
1165                 error = ENOMEM;
1166                 goto out;
1167         }
1168
1169         /* Local intra-module relocations */
1170         error = link_elf_reloc_local(lf, false);
1171         if (error != 0)
1172                 goto out;
1173
1174         /* Pull in dependencies */
1175         VOP_UNLOCK(nd->ni_vp);
1176         error = linker_load_dependencies(lf);
1177         vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY);
1178         if (error)
1179                 goto out;
1180
1181         /* External relocations */
1182         error = relocate_file(ef);
1183         if (error)
1184                 goto out;
1185
1186         /* Notify MD code that a module is being loaded. */
1187         error = elf_cpu_load_file(lf);
1188         if (error)
1189                 goto out;
1190
1191 #if defined(__i386__) || defined(__amd64__)
1192         /* Now ifuncs. */
1193         error = link_elf_reloc_local(lf, true);
1194         if (error != 0)
1195                 goto out;
1196 #endif
1197
1198         link_elf_protect(ef);
1199         link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
1200         *result = lf;
1201
1202 out:
1203         VOP_UNLOCK(nd->ni_vp);
1204         vn_close(nd->ni_vp, FREAD, td->td_ucred, td);
1205         free(nd, M_TEMP);
1206         if (error && lf)
1207                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1208         free(hdr, M_LINKER);
1209
1210         return error;
1211 }
1212
1213 static void
1214 link_elf_unload_file(linker_file_t file)
1215 {
1216         elf_file_t ef = (elf_file_t) file;
1217         u_int i;
1218
1219         /* Notify MD code that a module is being unloaded. */
1220         elf_cpu_unload_file(file);
1221
1222         if (ef->progtab) {
1223                 for (i = 0; i < ef->nprogtab; i++) {
1224                         if (ef->progtab[i].size == 0)
1225                                 continue;
1226                         if (ef->progtab[i].name == NULL)
1227                                 continue;
1228                         if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
1229                                 dpcpu_free(ef->progtab[i].addr,
1230                                     ef->progtab[i].size);
1231 #ifdef VIMAGE
1232                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
1233                                 vnet_data_free(ef->progtab[i].addr,
1234                                     ef->progtab[i].size);
1235 #endif
1236                 }
1237         }
1238         if (ef->preloaded) {
1239                 free(ef->reltab, M_LINKER);
1240                 free(ef->relatab, M_LINKER);
1241                 free(ef->progtab, M_LINKER);
1242                 free(ef->ctftab, M_LINKER);
1243                 free(ef->ctfoff, M_LINKER);
1244                 free(ef->typoff, M_LINKER);
1245                 if (file->pathname != NULL)
1246                         preload_delete_name(file->pathname);
1247                 return;
1248         }
1249
1250         for (i = 0; i < ef->nreltab; i++)
1251                 free(ef->reltab[i].rel, M_LINKER);
1252         for (i = 0; i < ef->nrelatab; i++)
1253                 free(ef->relatab[i].rela, M_LINKER);
1254         free(ef->reltab, M_LINKER);
1255         free(ef->relatab, M_LINKER);
1256         free(ef->progtab, M_LINKER);
1257
1258         if (ef->object != NULL)
1259                 vm_map_remove(kernel_map, (vm_offset_t)ef->address,
1260                     (vm_offset_t)ef->address + ptoa(ef->object->size));
1261         free(ef->e_shdr, M_LINKER);
1262         free(ef->ddbsymtab, M_LINKER);
1263         free(ef->ddbstrtab, M_LINKER);
1264         free(ef->shstrtab, M_LINKER);
1265         free(ef->ctftab, M_LINKER);
1266         free(ef->ctfoff, M_LINKER);
1267         free(ef->typoff, M_LINKER);
1268 }
1269
1270 static const char *
1271 symbol_name(elf_file_t ef, Elf_Size r_info)
1272 {
1273         const Elf_Sym *ref;
1274
1275         if (ELF_R_SYM(r_info)) {
1276                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1277                 return ef->ddbstrtab + ref->st_name;
1278         } else
1279                 return NULL;
1280 }
1281
1282 static Elf_Addr
1283 findbase(elf_file_t ef, int sec)
1284 {
1285         int i;
1286         Elf_Addr base = 0;
1287
1288         for (i = 0; i < ef->nprogtab; i++) {
1289                 if (sec == ef->progtab[i].sec) {
1290                         base = (Elf_Addr)ef->progtab[i].addr;
1291                         break;
1292                 }
1293         }
1294         return base;
1295 }
1296
1297 static int
1298 relocate_file(elf_file_t ef)
1299 {
1300         const Elf_Rel *rellim;
1301         const Elf_Rel *rel;
1302         const Elf_Rela *relalim;
1303         const Elf_Rela *rela;
1304         const char *symname;
1305         const Elf_Sym *sym;
1306         int i;
1307         Elf_Size symidx;
1308         Elf_Addr base;
1309
1310         /* Perform relocations without addend if there are any: */
1311         for (i = 0; i < ef->nreltab; i++) {
1312                 rel = ef->reltab[i].rel;
1313                 if (rel == NULL) {
1314                         link_elf_error(ef->lf.filename, "lost a reltab!");
1315                         return (ENOEXEC);
1316                 }
1317                 rellim = rel + ef->reltab[i].nrel;
1318                 base = findbase(ef, ef->reltab[i].sec);
1319                 if (base == 0) {
1320                         link_elf_error(ef->lf.filename, "lost base for reltab");
1321                         return (ENOEXEC);
1322                 }
1323                 for ( ; rel < rellim; rel++) {
1324                         symidx = ELF_R_SYM(rel->r_info);
1325                         if (symidx >= ef->ddbsymcnt)
1326                                 continue;
1327                         sym = ef->ddbsymtab + symidx;
1328                         /* Local relocs are already done */
1329                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1330                                 continue;
1331                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1332                             elf_obj_lookup)) {
1333                                 symname = symbol_name(ef, rel->r_info);
1334                                 printf("link_elf_obj: symbol %s undefined\n",
1335                                     symname);
1336                                 return (ENOENT);
1337                         }
1338                 }
1339         }
1340
1341         /* Perform relocations with addend if there are any: */
1342         for (i = 0; i < ef->nrelatab; i++) {
1343                 rela = ef->relatab[i].rela;
1344                 if (rela == NULL) {
1345                         link_elf_error(ef->lf.filename, "lost a relatab!");
1346                         return (ENOEXEC);
1347                 }
1348                 relalim = rela + ef->relatab[i].nrela;
1349                 base = findbase(ef, ef->relatab[i].sec);
1350                 if (base == 0) {
1351                         link_elf_error(ef->lf.filename,
1352                             "lost base for relatab");
1353                         return (ENOEXEC);
1354                 }
1355                 for ( ; rela < relalim; rela++) {
1356                         symidx = ELF_R_SYM(rela->r_info);
1357                         if (symidx >= ef->ddbsymcnt)
1358                                 continue;
1359                         sym = ef->ddbsymtab + symidx;
1360                         /* Local relocs are already done */
1361                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1362                                 continue;
1363                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1364                             elf_obj_lookup)) {
1365                                 symname = symbol_name(ef, rela->r_info);
1366                                 printf("link_elf_obj: symbol %s undefined\n",
1367                                     symname);
1368                                 return (ENOENT);
1369                         }
1370                 }
1371         }
1372
1373         /*
1374          * Only clean SHN_FBSD_CACHED for successful return.  If we
1375          * modified symbol table for the object but found an
1376          * unresolved symbol, there is no reason to roll back.
1377          */
1378         elf_obj_cleanup_globals_cache(ef);
1379
1380         return (0);
1381 }
1382
1383 static int
1384 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1385 {
1386         elf_file_t ef = (elf_file_t) lf;
1387         const Elf_Sym *symp;
1388         const char *strp;
1389         int i;
1390
1391         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1392                 strp = ef->ddbstrtab + symp->st_name;
1393                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1394                         *sym = (c_linker_sym_t) symp;
1395                         return 0;
1396                 }
1397         }
1398         return ENOENT;
1399 }
1400
1401 static int
1402 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1403     linker_symval_t *symval)
1404 {
1405         elf_file_t ef;
1406         const Elf_Sym *es;
1407         caddr_t val;
1408
1409         ef = (elf_file_t) lf;
1410         es = (const Elf_Sym*) sym;
1411         val = (caddr_t)es->st_value;
1412         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1413                 symval->name = ef->ddbstrtab + es->st_name;
1414                 val = (caddr_t)es->st_value;
1415                 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1416                         val = ((caddr_t (*)(void))val)();
1417                 symval->value = val;
1418                 symval->size = es->st_size;
1419                 return 0;
1420         }
1421         return ENOENT;
1422 }
1423
1424 static int
1425 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1426     c_linker_sym_t *sym, long *diffp)
1427 {
1428         elf_file_t ef = (elf_file_t) lf;
1429         u_long off = (uintptr_t) (void *) value;
1430         u_long diff = off;
1431         u_long st_value;
1432         const Elf_Sym *es;
1433         const Elf_Sym *best = NULL;
1434         int i;
1435
1436         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1437                 if (es->st_name == 0)
1438                         continue;
1439                 st_value = es->st_value;
1440                 if (off >= st_value) {
1441                         if (off - st_value < diff) {
1442                                 diff = off - st_value;
1443                                 best = es;
1444                                 if (diff == 0)
1445                                         break;
1446                         } else if (off - st_value == diff) {
1447                                 best = es;
1448                         }
1449                 }
1450         }
1451         if (best == NULL)
1452                 *diffp = off;
1453         else
1454                 *diffp = diff;
1455         *sym = (c_linker_sym_t) best;
1456
1457         return 0;
1458 }
1459
1460 /*
1461  * Look up a linker set on an ELF system.
1462  */
1463 static int
1464 link_elf_lookup_set(linker_file_t lf, const char *name,
1465     void ***startp, void ***stopp, int *countp)
1466 {
1467         elf_file_t ef = (elf_file_t)lf;
1468         void **start, **stop;
1469         int i, count;
1470
1471         /* Relative to section number */
1472         for (i = 0; i < ef->nprogtab; i++) {
1473                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1474                     strcmp(ef->progtab[i].name + 4, name) == 0) {
1475                         start  = (void **)ef->progtab[i].addr;
1476                         stop = (void **)((char *)ef->progtab[i].addr +
1477                             ef->progtab[i].size);
1478                         count = stop - start;
1479                         if (startp)
1480                                 *startp = start;
1481                         if (stopp)
1482                                 *stopp = stop;
1483                         if (countp)
1484                                 *countp = count;
1485                         return (0);
1486                 }
1487         }
1488         return (ESRCH);
1489 }
1490
1491 static int
1492 link_elf_each_function_name(linker_file_t file,
1493     int (*callback)(const char *, void *), void *opaque)
1494 {
1495         elf_file_t ef = (elf_file_t)file;
1496         const Elf_Sym *symp;
1497         int i, error;
1498
1499         /* Exhaustive search */
1500         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1501                 if (symp->st_value != 0 &&
1502                     (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1503                     ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1504                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
1505                         if (error)
1506                                 return (error);
1507                 }
1508         }
1509         return (0);
1510 }
1511
1512 static int
1513 link_elf_each_function_nameval(linker_file_t file,
1514     linker_function_nameval_callback_t callback, void *opaque)
1515 {
1516         linker_symval_t symval;
1517         elf_file_t ef = (elf_file_t)file;
1518         const Elf_Sym* symp;
1519         int i, error;
1520
1521         /* Exhaustive search */
1522         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1523                 if (symp->st_value != 0 &&
1524                     (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1525                     ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1526                         error = link_elf_symbol_values(file,
1527                             (c_linker_sym_t)symp, &symval);
1528                         if (error)
1529                                 return (error);
1530                         error = callback(file, i, &symval, opaque);
1531                         if (error)
1532                                 return (error);
1533                 }
1534         }
1535         return (0);
1536 }
1537
1538 static void
1539 elf_obj_cleanup_globals_cache(elf_file_t ef)
1540 {
1541         Elf_Sym *sym;
1542         Elf_Size i;
1543
1544         for (i = 0; i < ef->ddbsymcnt; i++) {
1545                 sym = ef->ddbsymtab + i;
1546                 if (sym->st_shndx == SHN_FBSD_CACHED) {
1547                         sym->st_shndx = SHN_UNDEF;
1548                         sym->st_value = 0;
1549                 }
1550         }
1551 }
1552
1553 /*
1554  * Symbol lookup function that can be used when the symbol index is known (ie
1555  * in relocations). It uses the symbol index instead of doing a fully fledged
1556  * hash table based lookup when such is valid. For example for local symbols.
1557  * This is not only more efficient, it's also more correct. It's not always
1558  * the case that the symbol can be found through the hash table.
1559  */
1560 static int
1561 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1562 {
1563         elf_file_t ef = (elf_file_t)lf;
1564         Elf_Sym *sym;
1565         const char *symbol;
1566         Elf_Addr res1;
1567
1568         /* Don't even try to lookup the symbol if the index is bogus. */
1569         if (symidx >= ef->ddbsymcnt) {
1570                 *res = 0;
1571                 return (EINVAL);
1572         }
1573
1574         sym = ef->ddbsymtab + symidx;
1575
1576         /* Quick answer if there is a definition included. */
1577         if (sym->st_shndx != SHN_UNDEF) {
1578                 res1 = (Elf_Addr)sym->st_value;
1579                 if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC)
1580                         res1 = ((Elf_Addr (*)(void))res1)();
1581                 *res = res1;
1582                 return (0);
1583         }
1584
1585         /* If we get here, then it is undefined and needs a lookup. */
1586         switch (ELF_ST_BIND(sym->st_info)) {
1587         case STB_LOCAL:
1588                 /* Local, but undefined? huh? */
1589                 *res = 0;
1590                 return (EINVAL);
1591
1592         case STB_GLOBAL:
1593         case STB_WEAK:
1594                 /* Relative to Data or Function name */
1595                 symbol = ef->ddbstrtab + sym->st_name;
1596
1597                 /* Force a lookup failure if the symbol name is bogus. */
1598                 if (*symbol == 0) {
1599                         *res = 0;
1600                         return (EINVAL);
1601                 }
1602                 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1603
1604                 /*
1605                  * Cache global lookups during module relocation. The failure
1606                  * case is particularly expensive for callers, who must scan
1607                  * through the entire globals table doing strcmp(). Cache to
1608                  * avoid doing such work repeatedly.
1609                  *
1610                  * After relocation is complete, undefined globals will be
1611                  * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1612                  * above.
1613                  */
1614                 if (res1 != 0) {
1615                         sym->st_shndx = SHN_FBSD_CACHED;
1616                         sym->st_value = res1;
1617                         *res = res1;
1618                         return (0);
1619                 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1620                         sym->st_value = 0;
1621                         *res = 0;
1622                         return (0);
1623                 }
1624                 return (EINVAL);
1625
1626         default:
1627                 return (EINVAL);
1628         }
1629 }
1630
1631 static void
1632 link_elf_fix_link_set(elf_file_t ef)
1633 {
1634         static const char startn[] = "__start_";
1635         static const char stopn[] = "__stop_";
1636         Elf_Sym *sym;
1637         const char *sym_name, *linkset_name;
1638         Elf_Addr startp, stopp;
1639         Elf_Size symidx;
1640         int start, i;
1641
1642         startp = stopp = 0;
1643         for (symidx = 1 /* zero entry is special */;
1644                 symidx < ef->ddbsymcnt; symidx++) {
1645                 sym = ef->ddbsymtab + symidx;
1646                 if (sym->st_shndx != SHN_UNDEF)
1647                         continue;
1648
1649                 sym_name = ef->ddbstrtab + sym->st_name;
1650                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1651                         start = 1;
1652                         linkset_name = sym_name + sizeof(startn) - 1;
1653                 }
1654                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1655                         start = 0;
1656                         linkset_name = sym_name + sizeof(stopn) - 1;
1657                 }
1658                 else
1659                         continue;
1660
1661                 for (i = 0; i < ef->nprogtab; i++) {
1662                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1663                                 startp = (Elf_Addr)ef->progtab[i].addr;
1664                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1665                                 break;
1666                         }
1667                 }
1668                 if (i == ef->nprogtab)
1669                         continue;
1670
1671                 sym->st_value = start ? startp : stopp;
1672                 sym->st_shndx = i;
1673         }
1674 }
1675
1676 static int
1677 link_elf_reloc_local(linker_file_t lf, bool ifuncs)
1678 {
1679         elf_file_t ef = (elf_file_t)lf;
1680         const Elf_Rel *rellim;
1681         const Elf_Rel *rel;
1682         const Elf_Rela *relalim;
1683         const Elf_Rela *rela;
1684         const Elf_Sym *sym;
1685         Elf_Addr base;
1686         int i;
1687         Elf_Size symidx;
1688
1689         link_elf_fix_link_set(ef);
1690
1691         /* Perform relocations without addend if there are any: */
1692         for (i = 0; i < ef->nreltab; i++) {
1693                 rel = ef->reltab[i].rel;
1694                 if (rel == NULL) {
1695                         link_elf_error(ef->lf.filename, "lost a reltab");
1696                         return (ENOEXEC);
1697                 }
1698                 rellim = rel + ef->reltab[i].nrel;
1699                 base = findbase(ef, ef->reltab[i].sec);
1700                 if (base == 0) {
1701                         link_elf_error(ef->lf.filename, "lost base for reltab");
1702                         return (ENOEXEC);
1703                 }
1704                 for ( ; rel < rellim; rel++) {
1705                         symidx = ELF_R_SYM(rel->r_info);
1706                         if (symidx >= ef->ddbsymcnt)
1707                                 continue;
1708                         sym = ef->ddbsymtab + symidx;
1709                         /* Only do local relocs */
1710                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1711                                 continue;
1712                         if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1713                             elf_is_ifunc_reloc(rel->r_info)) != ifuncs)
1714                                 continue;
1715                         if (elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1716                             elf_obj_lookup) != 0)
1717                                 return (ENOEXEC);
1718                 }
1719         }
1720
1721         /* Perform relocations with addend if there are any: */
1722         for (i = 0; i < ef->nrelatab; i++) {
1723                 rela = ef->relatab[i].rela;
1724                 if (rela == NULL) {
1725                         link_elf_error(ef->lf.filename, "lost a relatab!");
1726                         return (ENOEXEC);
1727                 }
1728                 relalim = rela + ef->relatab[i].nrela;
1729                 base = findbase(ef, ef->relatab[i].sec);
1730                 if (base == 0) {
1731                         link_elf_error(ef->lf.filename, "lost base for reltab");
1732                         return (ENOEXEC);
1733                 }
1734                 for ( ; rela < relalim; rela++) {
1735                         symidx = ELF_R_SYM(rela->r_info);
1736                         if (symidx >= ef->ddbsymcnt)
1737                                 continue;
1738                         sym = ef->ddbsymtab + symidx;
1739                         /* Only do local relocs */
1740                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1741                                 continue;
1742                         if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1743                             elf_is_ifunc_reloc(rela->r_info)) != ifuncs)
1744                                 continue;
1745                         if (elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1746                             elf_obj_lookup) != 0)
1747                                 return (ENOEXEC);
1748                 }
1749         }
1750         return (0);
1751 }
1752
1753 static long
1754 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1755 {
1756     elf_file_t ef = (elf_file_t)lf;
1757
1758     *symtab = ef->ddbsymtab;
1759
1760     if (*symtab == NULL)
1761         return (0);
1762
1763     return (ef->ddbsymcnt);
1764 }
1765
1766 static long
1767 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1768 {
1769     elf_file_t ef = (elf_file_t)lf;
1770
1771     *strtab = ef->ddbstrtab;
1772
1773     if (*strtab == NULL)
1774         return (0);
1775
1776     return (ef->ddbstrcnt);
1777 }