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
  91 typedef struct elf_file {
  92         struct linker_file lf;          /* Common fields */
  93
  94         int             preloaded;
  95         caddr_t         address;        /* Relocation address */
  96         vm_object_t     object;         /* VM object to hold file pages */
  97         Elf_Shdr        *e_shdr;
  98
  99         Elf_progent     *progtab;
 100         u_int           nprogtab;
 101
 102         Elf_relaent     *relatab;
 103         u_int           nrelatab;
 104
 105         Elf_relent      *reltab;
 106         int             nreltab;
 107
 108         Elf_Sym         *ddbsymtab;     /* The symbol table we are using */
 109         long            ddbsymcnt;      /* Number of symbols */
 110         caddr_t         ddbstrtab;      /* String table */
 111         long            ddbstrcnt;      /* number of bytes in string table */
 112
 113         caddr_t         shstrtab;       /* Section name string table */
 114         long            shstrcnt;       /* number of bytes in string table */
 115
 116         caddr_t         ctftab;         /* CTF table */
 117         long            ctfcnt;         /* number of bytes in CTF table */
 118         caddr_t         ctfoff;         /* CTF offset table */
 119         caddr_t         typoff;         /* Type offset table */
 120         long            typlen;         /* Number of type entries. */
 121
 122 } *elf_file_t;
 123
 124 #include <kern/kern_ctf.c>
 125
 126 static int      link_elf_link_preload(linker_class_t cls,
 127                     const char *, linker_file_t *);
 128 static int      link_elf_link_preload_finish(linker_file_t);
 129 static int      link_elf_load_file(linker_class_t, const char *, linker_file_t *);
 130 static int      link_elf_lookup_symbol(linker_file_t, const char *,
 131                     c_linker_sym_t *);
 132 static int      link_elf_symbol_values(linker_file_t, c_linker_sym_t,
 133                     linker_symval_t *);
 134 static int      link_elf_search_symbol(linker_file_t, caddr_t value,
 135                     c_linker_sym_t *sym, long *diffp);
 136
 137 static void     link_elf_unload_file(linker_file_t);
 138 static int      link_elf_lookup_set(linker_file_t, const char *,
 139                     void ***, void ***, int *);
 140 static int      link_elf_each_function_name(linker_file_t,
 141                     int (*)(const char *, void *), void *);
 142 static int      link_elf_each_function_nameval(linker_file_t,
 143                                 linker_function_nameval_callback_t,
 144                                 void *);
 145 static int      link_elf_reloc_local(linker_file_t, bool);
 146 static long     link_elf_symtab_get(linker_file_t, const Elf_Sym **);
 147 static long     link_elf_strtab_get(linker_file_t, caddr_t *);
 148
 149 static int      elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps,
 150                     Elf_Addr *);
 151
 152 static kobj_method_t link_elf_methods[] = {
 153         KOBJMETHOD(linker_lookup_symbol,        link_elf_lookup_symbol),
 154         KOBJMETHOD(linker_symbol_values,        link_elf_symbol_values),
 155         KOBJMETHOD(linker_search_symbol,        link_elf_search_symbol),
 156         KOBJMETHOD(linker_unload,               link_elf_unload_file),
 157         KOBJMETHOD(linker_load_file,            link_elf_load_file),
 158         KOBJMETHOD(linker_link_preload,         link_elf_link_preload),
 159         KOBJMETHOD(linker_link_preload_finish,  link_elf_link_preload_finish),
 160         KOBJMETHOD(linker_lookup_set,           link_elf_lookup_set),
 161         KOBJMETHOD(linker_each_function_name,   link_elf_each_function_name),
 162         KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
 163         KOBJMETHOD(linker_ctf_get,              link_elf_ctf_get),
 164         KOBJMETHOD(linker_symtab_get,           link_elf_symtab_get),
 165         KOBJMETHOD(linker_strtab_get,           link_elf_strtab_get),
 166         KOBJMETHOD_END
 167 };
 168
 169 static struct linker_class link_elf_class = {
 170 #if ELF_TARG_CLASS == ELFCLASS32
 171         "elf32_obj",
 172 #else
 173         "elf64_obj",
 174 #endif
 175         link_elf_methods, sizeof(struct elf_file)
 176 };
 177
 178 static int      relocate_file(elf_file_t ef);
 179 static void     elf_obj_cleanup_globals_cache(elf_file_t);
 180
 181 static void
 182 link_elf_error(const char *filename, const char *s)
 183 {
 184         if (filename == NULL)
 185                 printf("kldload: %s\n", s);
 186         else
 187                 printf("kldload: %s: %s\n", filename, s);
 188 }
 189
 190 static void
 191 link_elf_init(void *arg)
 192 {
 193
 194         linker_add_class(&link_elf_class);
 195 }
 196 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, NULL);
 197
 198 static void
 199 link_elf_protect_range(elf_file_t ef, vm_offset_t start, vm_offset_t end,
 200     vm_prot_t prot)
 201 {
 202         int error __unused;
 203
 204         KASSERT(start <= end && start >= (vm_offset_t)ef->address &&
 205             end <= round_page((vm_offset_t)ef->address + ef->lf.size),
 206             ("link_elf_protect_range: invalid range %#jx-%#jx",
 207             (uintmax_t)start, (uintmax_t)end));
 208
 209         if (start == end)
 210                 return;
 211         if (ef->preloaded) {
 212 #ifdef __amd64__
 213                 error = pmap_change_prot(start, end - start, prot);
 214                 KASSERT(error == 0,
 215                     ("link_elf_protect_range: pmap_change_prot() returned %d",
 216                     error));
 217 #endif
 218                 return;
 219         }
 220         error = vm_map_protect(kernel_map, start, end, prot, FALSE);
 221         KASSERT(error == KERN_SUCCESS,
 222             ("link_elf_protect_range: vm_map_protect() returned %d", error));
 223 }
 224
 225 /*
 226  * Restrict permissions on linker file memory based on section flags.
 227  * Sections need not be page-aligned, so overlap within a page is possible.
 228  */
 229 static void
 230 link_elf_protect(elf_file_t ef)
 231 {
 232         vm_offset_t end, segend, segstart, start;
 233         vm_prot_t gapprot, prot, segprot;
 234         int i;
 235
 236         /*
 237          * If the file was preloaded, the last page may contain other preloaded
 238          * data which may need to be writeable.  ELF files are always
 239          * page-aligned, but other preloaded data, such as entropy or CPU
 240          * microcode may be loaded with a smaller alignment.
 241          */
 242         gapprot = ef->preloaded ? VM_PROT_RW : VM_PROT_READ;
 243
 244         start = end = (vm_offset_t)ef->address;
 245         prot = VM_PROT_READ;
 246         for (i = 0; i < ef->nprogtab; i++) {
 247                 /*
 248                  * VNET and DPCPU sections have their memory allocated by their
 249                  * respective subsystems.
 250                  */
 251                 if (ef->progtab[i].name != NULL && (
 252 #ifdef VIMAGE
 253                     strcmp(ef->progtab[i].name, VNET_SETNAME) == 0 ||
 254 #endif
 255                     strcmp(ef->progtab[i].name, DPCPU_SETNAME) == 0))
 256                         continue;
 257
 258                 segstart = trunc_page((vm_offset_t)ef->progtab[i].addr);
 259                 segend = round_page((vm_offset_t)ef->progtab[i].addr +
 260                     ef->progtab[i].size);
 261                 segprot = VM_PROT_READ;
 262                 if ((ef->progtab[i].flags & SHF_WRITE) != 0)
 263                         segprot |= VM_PROT_WRITE;
 264                 if ((ef->progtab[i].flags & SHF_EXECINSTR) != 0)
 265                         segprot |= VM_PROT_EXECUTE;
 266
 267                 if (end <= segstart) {
 268                         /*
 269                          * Case 1: there is no overlap between the previous
 270                          * segment and this one.  Apply protections to the
 271                          * previous segment, and protect the gap between the
 272                          * previous and current segments, if any.
 273                          */
 274                         link_elf_protect_range(ef, start, end, prot);
 275                         link_elf_protect_range(ef, end, segstart, gapprot);
 276
 277                         start = segstart;
 278                         end = segend;
 279                         prot = segprot;
 280                 } else if (start < segstart && end == segend) {
 281                         /*
 282                          * Case 2: the current segment is a subrange of the
 283                          * previous segment.  Apply protections to the
 284                          * non-overlapping portion of the previous segment.
 285                          */
 286                         link_elf_protect_range(ef, start, segstart, prot);
 287
 288                         start = segstart;
 289                         prot |= segprot;
 290                 } else if (end < segend) {
 291                         /*
 292                          * Case 3: there is partial overlap between the previous
 293                          * and current segments.  Apply protections to the
 294                          * non-overlapping portion of the previous segment, and
 295                          * then the overlap, which must use the union of the two
 296                          * segments' protections.
 297                          */
 298                         link_elf_protect_range(ef, start, segstart, prot);
 299                         link_elf_protect_range(ef, segstart, end,
 300                             prot | segprot);
 301                         start = end;
 302                         end = segend;
 303                         prot = segprot;
 304                 } else {
 305                         /*
 306                          * Case 4: the two segments reside in the same page.
 307                          */
 308                         prot |= segprot;
 309                 }
 310         }
 311
 312         /*
 313          * Fix up the last unprotected segment and trailing data.
 314          */
 315         link_elf_protect_range(ef, start, end, prot);
 316         link_elf_protect_range(ef, end,
 317             round_page((vm_offset_t)ef->address + ef->lf.size), gapprot);
 318 }
 319
 320 static int
 321 link_elf_link_preload(linker_class_t cls, const char *filename,
 322     linker_file_t *result)
 323 {
 324         Elf_Ehdr *hdr;
 325         Elf_Shdr *shdr;
 326         Elf_Sym *es;
 327         void *modptr, *baseptr, *sizeptr;
 328         char *type;
 329         elf_file_t ef;
 330         linker_file_t lf;
 331         Elf_Addr off;
 332         int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
 333
 334         /* Look to see if we have the file preloaded */
 335         modptr = preload_search_by_name(filename);
 336         if (modptr == NULL)
 337                 return ENOENT;
 338
 339         type = (char *)preload_search_info(modptr, MODINFO_TYPE);
 340         baseptr = preload_search_info(modptr, MODINFO_ADDR);
 341         sizeptr = preload_search_info(modptr, MODINFO_SIZE);
 342         hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
 343             MODINFOMD_ELFHDR);
 344         shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
 345             MODINFOMD_SHDR);
 346         if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
 347             " obj module") != 0 &&
 348             strcmp(type, "elf obj module") != 0)) {
 349                 return (EFTYPE);
 350         }
 351         if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
 352             shdr == NULL)
 353                 return (EINVAL);
 354
 355         lf = linker_make_file(filename, &link_elf_class);
 356         if (lf == NULL)
 357                 return (ENOMEM);
 358
 359         ef = (elf_file_t)lf;
 360         ef->preloaded = 1;
 361         ef->address = *(caddr_t *)baseptr;
 362         lf->address = *(caddr_t *)baseptr;
 363         lf->size = *(size_t *)sizeptr;
 364
 365         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
 366             hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
 367             hdr->e_ident[EI_VERSION] != EV_CURRENT ||
 368             hdr->e_version != EV_CURRENT ||
 369             hdr->e_type != ET_REL ||
 370             hdr->e_machine != ELF_TARG_MACH) {
 371                 error = EFTYPE;
 372                 goto out;
 373         }
 374         ef->e_shdr = shdr;
 375
 376         /* Scan the section header for information and table sizing. */
 377         symtabindex = -1;
 378         symstrindex = -1;
 379         for (i = 0; i < hdr->e_shnum; i++) {
 380                 switch (shdr[i].sh_type) {
 381                 case SHT_PROGBITS:
 382                 case SHT_NOBITS:
 383 #ifdef __amd64__
 384                 case SHT_X86_64_UNWIND:
 385 #endif
 386                         /* Ignore sections not loaded by the loader. */
 387                         if (shdr[i].sh_addr == 0)
 388                                 break;
 389                         ef->nprogtab++;
 390                         break;
 391                 case SHT_SYMTAB:
 392                         symtabindex = i;
 393                         symstrindex = shdr[i].sh_link;
 394                         break;
 395                 case SHT_REL:
 396                         /*
 397                          * Ignore relocation tables for sections not
 398                          * loaded by the loader.
 399                          */
 400                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 401                                 break;
 402                         ef->nreltab++;
 403                         break;
 404                 case SHT_RELA:
 405                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 406                                 break;
 407                         ef->nrelatab++;
 408                         break;
 409                 }
 410         }
 411
 412         shstrindex = hdr->e_shstrndx;
 413         if (ef->nprogtab == 0 || symstrindex < 0 ||
 414             symstrindex >= hdr->e_shnum ||
 415             shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
 416             shstrindex >= hdr->e_shnum ||
 417             shdr[shstrindex].sh_type != SHT_STRTAB) {
 418                 printf("%s: bad/missing section headers\n", filename);
 419                 error = ENOEXEC;
 420                 goto out;
 421         }
 422
 423         /* Allocate space for tracking the load chunks */
 424         if (ef->nprogtab != 0)
 425                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 426                     M_LINKER, M_WAITOK | M_ZERO);
 427         if (ef->nreltab != 0)
 428                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 429                     M_LINKER, M_WAITOK | M_ZERO);
 430         if (ef->nrelatab != 0)
 431                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 432                     M_LINKER, M_WAITOK | M_ZERO);
 433         if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
 434             (ef->nreltab != 0 && ef->reltab == NULL) ||
 435             (ef->nrelatab != 0 && ef->relatab == NULL)) {
 436                 error = ENOMEM;
 437                 goto out;
 438         }
 439
 440         /* XXX, relocate the sh_addr fields saved by the loader. */
 441         off = 0;
 442         for (i = 0; i < hdr->e_shnum; i++) {
 443                 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
 444                         off = shdr[i].sh_addr;
 445         }
 446         for (i = 0; i < hdr->e_shnum; i++) {
 447                 if (shdr[i].sh_addr != 0)
 448                         shdr[i].sh_addr = shdr[i].sh_addr - off +
 449                             (Elf_Addr)ef->address;
 450         }
 451
 452         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 453         ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
 454         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 455         ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
 456         ef->shstrcnt = shdr[shstrindex].sh_size;
 457         ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
 458
 459         /* Now fill out progtab and the relocation tables. */
 460         pb = 0;
 461         rl = 0;
 462         ra = 0;
 463         for (i = 0; i < hdr->e_shnum; i++) {
 464                 switch (shdr[i].sh_type) {
 465                 case SHT_PROGBITS:
 466                 case SHT_NOBITS:
 467 #ifdef __amd64__
 468                 case SHT_X86_64_UNWIND:
 469 #endif
 470                         if (shdr[i].sh_addr == 0)
 471                                 break;
 472                         ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
 473                         if (shdr[i].sh_type == SHT_PROGBITS)
 474                                 ef->progtab[pb].name = "<<PROGBITS>>";
 475 #ifdef __amd64__
 476                         else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
 477                                 ef->progtab[pb].name = "<<UNWIND>>";
 478 #endif
 479                         else
 480                                 ef->progtab[pb].name = "<<NOBITS>>";
 481                         ef->progtab[pb].size = shdr[i].sh_size;
 482                         ef->progtab[pb].flags = shdr[i].sh_flags;
 483                         ef->progtab[pb].sec = i;
 484                         if (ef->shstrtab && shdr[i].sh_name != 0)
 485                                 ef->progtab[pb].name =
 486                                     ef->shstrtab + shdr[i].sh_name;
 487                         if (ef->progtab[pb].name != NULL &&
 488                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
 489                                 void *dpcpu;
 490
 491                                 dpcpu = dpcpu_alloc(shdr[i].sh_size);
 492                                 if (dpcpu == NULL) {
 493                                         printf("%s: pcpu module space is out "
 494                                             "of space; cannot allocate %#jx "
 495                                             "for %s\n", __func__,
 496                                             (uintmax_t)shdr[i].sh_size,
 497                                             filename);
 498                                         error = ENOSPC;
 499                                         goto out;
 500                                 }
 501                                 memcpy(dpcpu, ef->progtab[pb].addr,
 502                                     ef->progtab[pb].size);
 503                                 dpcpu_copy(dpcpu, shdr[i].sh_size);
 504                                 ef->progtab[pb].addr = dpcpu;
 505 #ifdef VIMAGE
 506                         } else if (ef->progtab[pb].name != NULL &&
 507                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
 508                                 void *vnet_data;
 509
 510                                 vnet_data = vnet_data_alloc(shdr[i].sh_size);
 511                                 if (vnet_data == NULL) {
 512                                         printf("%s: vnet module space is out "
 513                                             "of space; cannot allocate %#jx "
 514                                             "for %s\n", __func__,
 515                                             (uintmax_t)shdr[i].sh_size,
 516                                             filename);
 517                                         error = ENOSPC;
 518                                         goto out;
 519                                 }
 520                                 memcpy(vnet_data, ef->progtab[pb].addr,
 521                                     ef->progtab[pb].size);
 522                                 vnet_data_copy(vnet_data, shdr[i].sh_size);
 523                                 ef->progtab[pb].addr = vnet_data;
 524 #endif
 525                         } else if (ef->progtab[pb].name != NULL &&
 526                             !strcmp(ef->progtab[pb].name, ".ctors")) {
 527                                 lf->ctors_addr = ef->progtab[pb].addr;
 528                                 lf->ctors_size = shdr[i].sh_size;
 529                         }
 530
 531                         /* Update all symbol values with the offset. */
 532                         for (j = 0; j < ef->ddbsymcnt; j++) {
 533                                 es = &ef->ddbsymtab[j];
 534                                 if (es->st_shndx != i)
 535                                         continue;
 536                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
 537                         }
 538                         pb++;
 539                         break;
 540                 case SHT_REL:
 541                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 542                                 break;
 543                         ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
 544                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
 545                         ef->reltab[rl].sec = shdr[i].sh_info;
 546                         rl++;
 547                         break;
 548                 case SHT_RELA:
 549                         if (shdr[shdr[i].sh_info].sh_addr == 0)
 550                                 break;
 551                         ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
 552                         ef->relatab[ra].nrela =
 553                             shdr[i].sh_size / sizeof(Elf_Rela);
 554                         ef->relatab[ra].sec = shdr[i].sh_info;
 555                         ra++;
 556                         break;
 557                 }
 558         }
 559         if (pb != ef->nprogtab) {
 560                 printf("%s: lost progbits\n", filename);
 561                 error = ENOEXEC;
 562                 goto out;
 563         }
 564         if (rl != ef->nreltab) {
 565                 printf("%s: lost reltab\n", filename);
 566                 error = ENOEXEC;
 567                 goto out;
 568         }
 569         if (ra != ef->nrelatab) {
 570                 printf("%s: lost relatab\n", filename);
 571                 error = ENOEXEC;
 572                 goto out;
 573         }
 574
 575         /*
 576          * The file needs to be writeable and executable while applying
 577          * relocations.  Mapping protections are applied once relocation
 578          * processing is complete.
 579          */
 580         link_elf_protect_range(ef, (vm_offset_t)ef->address,
 581             round_page((vm_offset_t)ef->address + ef->lf.size), VM_PROT_ALL);
 582
 583         /* Local intra-module relocations */
 584         error = link_elf_reloc_local(lf, false);
 585         if (error != 0)
 586                 goto out;
 587         *result = lf;
 588         return (0);
 589
 590 out:
 591         /* preload not done this way */
 592         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 593         return (error);
 594 }
 595
 596 static void
 597 link_elf_invoke_ctors(caddr_t addr, size_t size)
 598 {
 599         void (**ctor)(void);
 600         size_t i, cnt;
 601
 602         if (addr == NULL || size == 0)
 603                 return;
 604         cnt = size / sizeof(*ctor);
 605         ctor = (void *)addr;
 606         for (i = 0; i < cnt; i++) {
 607                 if (ctor[i] != NULL)
 608                         (*ctor[i])();
 609         }
 610 }
 611
 612 static int
 613 link_elf_link_preload_finish(linker_file_t lf)
 614 {
 615         elf_file_t ef;
 616         int error;
 617
 618         ef = (elf_file_t)lf;
 619         error = relocate_file(ef);
 620         if (error)
 621                 return (error);
 622
 623         /* Notify MD code that a module is being loaded. */
 624         error = elf_cpu_load_file(lf);
 625         if (error)
 626                 return (error);
 627
 628 #if defined(__i386__) || defined(__amd64__)
 629         /* Now ifuncs. */
 630         error = link_elf_reloc_local(lf, true);
 631         if (error != 0)
 632                 return (error);
 633 #endif
 634
 635         /* Apply protections now that relocation processing is complete. */
 636         link_elf_protect(ef);
 637
 638         link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
 639         return (0);
 640 }
 641
 642 static int
 643 link_elf_load_file(linker_class_t cls, const char *filename,
 644     linker_file_t *result)
 645 {
 646         struct nameidata *nd;
 647         struct thread *td = curthread;  /* XXX */
 648         Elf_Ehdr *hdr;
 649         Elf_Shdr *shdr;
 650         Elf_Sym *es;
 651         int nbytes, i, j;
 652         vm_offset_t mapbase;
 653         size_t mapsize;
 654         int error = 0;
 655         ssize_t resid;
 656         int flags;
 657         elf_file_t ef;
 658         linker_file_t lf;
 659         int symtabindex;
 660         int symstrindex;
 661         int shstrindex;
 662         int nsym;
 663         int pb, rl, ra;
 664         int alignmask;
 665
 666         shdr = NULL;
 667         lf = NULL;
 668         mapsize = 0;
 669         hdr = NULL;
 670
 671         nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK);
 672         NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
 673         flags = FREAD;
 674         error = vn_open(nd, &flags, 0, NULL);
 675         if (error) {
 676                 free(nd, M_TEMP);
 677                 return error;
 678         }
 679         NDFREE(nd, NDF_ONLY_PNBUF);
 680         if (nd->ni_vp->v_type != VREG) {
 681                 error = ENOEXEC;
 682                 goto out;
 683         }
 684 #ifdef MAC
 685         error = mac_kld_check_load(td->td_ucred, nd->ni_vp);
 686         if (error) {
 687                 goto out;
 688         }
 689 #endif
 690
 691         /* Read the elf header from the file. */
 692         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
 693         error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0,
 694             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 695             &resid, td);
 696         if (error)
 697                 goto out;
 698         if (resid != 0){
 699                 error = ENOEXEC;
 700                 goto out;
 701         }
 702
 703         if (!IS_ELF(*hdr)) {
 704                 error = ENOEXEC;
 705                 goto out;
 706         }
 707
 708         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
 709             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
 710                 link_elf_error(filename, "Unsupported file layout");
 711                 error = ENOEXEC;
 712                 goto out;
 713         }
 714         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
 715             || hdr->e_version != EV_CURRENT) {
 716                 link_elf_error(filename, "Unsupported file version");
 717                 error = ENOEXEC;
 718                 goto out;
 719         }
 720         if (hdr->e_type != ET_REL) {
 721                 error = ENOSYS;
 722                 goto out;
 723         }
 724         if (hdr->e_machine != ELF_TARG_MACH) {
 725                 link_elf_error(filename, "Unsupported machine");
 726                 error = ENOEXEC;
 727                 goto out;
 728         }
 729
 730         lf = linker_make_file(filename, &link_elf_class);
 731         if (!lf) {
 732                 error = ENOMEM;
 733                 goto out;
 734         }
 735         ef = (elf_file_t) lf;
 736         ef->nprogtab = 0;
 737         ef->e_shdr = 0;
 738         ef->nreltab = 0;
 739         ef->nrelatab = 0;
 740
 741         /* Allocate and read in the section header */
 742         nbytes = hdr->e_shnum * hdr->e_shentsize;
 743         if (nbytes == 0 || hdr->e_shoff == 0 ||
 744             hdr->e_shentsize != sizeof(Elf_Shdr)) {
 745                 error = ENOEXEC;
 746                 goto out;
 747         }
 748         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
 749         ef->e_shdr = shdr;
 750         error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes,
 751             hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
 752             NOCRED, &resid, td);
 753         if (error)
 754                 goto out;
 755         if (resid) {
 756                 error = ENOEXEC;
 757                 goto out;
 758         }
 759
 760         /* Scan the section header for information and table sizing. */
 761         nsym = 0;
 762         symtabindex = -1;
 763         symstrindex = -1;
 764         for (i = 0; i < hdr->e_shnum; i++) {
 765                 if (shdr[i].sh_size == 0)
 766                         continue;
 767                 switch (shdr[i].sh_type) {
 768                 case SHT_PROGBITS:
 769                 case SHT_NOBITS:
 770 #ifdef __amd64__
 771                 case SHT_X86_64_UNWIND:
 772 #endif
 773                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 774                                 break;
 775                         ef->nprogtab++;
 776                         break;
 777                 case SHT_SYMTAB:
 778                         nsym++;
 779                         symtabindex = i;
 780                         symstrindex = shdr[i].sh_link;
 781                         break;
 782                 case SHT_REL:
 783                         /*
 784                          * Ignore relocation tables for unallocated
 785                          * sections.
 786                          */
 787                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
 788                                 break;
 789                         ef->nreltab++;
 790                         break;
 791                 case SHT_RELA:
 792                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
 793                                 break;
 794                         ef->nrelatab++;
 795                         break;
 796                 case SHT_STRTAB:
 797                         break;
 798                 }
 799         }
 800         if (ef->nprogtab == 0) {
 801                 link_elf_error(filename, "file has no contents");
 802                 error = ENOEXEC;
 803                 goto out;
 804         }
 805         if (nsym != 1) {
 806                 /* Only allow one symbol table for now */
 807                 link_elf_error(filename,
 808                     "file must have exactly one symbol table");
 809                 error = ENOEXEC;
 810                 goto out;
 811         }
 812         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
 813             shdr[symstrindex].sh_type != SHT_STRTAB) {
 814                 link_elf_error(filename, "file has invalid symbol strings");
 815                 error = ENOEXEC;
 816                 goto out;
 817         }
 818
 819         /* Allocate space for tracking the load chunks */
 820         if (ef->nprogtab != 0)
 821                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
 822                     M_LINKER, M_WAITOK | M_ZERO);
 823         if (ef->nreltab != 0)
 824                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
 825                     M_LINKER, M_WAITOK | M_ZERO);
 826         if (ef->nrelatab != 0)
 827                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
 828                     M_LINKER, M_WAITOK | M_ZERO);
 829
 830         if (symtabindex == -1) {
 831                 link_elf_error(filename, "lost symbol table index");
 832                 error = ENOEXEC;
 833                 goto out;
 834         }
 835         /* Allocate space for and load the symbol table */
 836         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
 837         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
 838         error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab,
 839             shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
 840             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 841             &resid, td);
 842         if (error)
 843                 goto out;
 844         if (resid != 0){
 845                 error = EINVAL;
 846                 goto out;
 847         }
 848
 849         /* Allocate space for and load the symbol strings */
 850         ef->ddbstrcnt = shdr[symstrindex].sh_size;
 851         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
 852         error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab,
 853             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
 854             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 855             &resid, td);
 856         if (error)
 857                 goto out;
 858         if (resid != 0){
 859                 error = EINVAL;
 860                 goto out;
 861         }
 862
 863         /* Do we have a string table for the section names?  */
 864         shstrindex = -1;
 865         if (hdr->e_shstrndx != 0 &&
 866             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
 867                 shstrindex = hdr->e_shstrndx;
 868                 ef->shstrcnt = shdr[shstrindex].sh_size;
 869                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
 870                     M_WAITOK);
 871                 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab,
 872                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
 873                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
 874                     &resid, td);
 875                 if (error)
 876                         goto out;
 877                 if (resid != 0){
 878                         error = EINVAL;
 879                         goto out;
 880                 }
 881         }
 882
 883         /* Size up code/data(progbits) and bss(nobits). */
 884         alignmask = 0;
 885         for (i = 0; i < hdr->e_shnum; i++) {
 886                 if (shdr[i].sh_size == 0)
 887                         continue;
 888                 switch (shdr[i].sh_type) {
 889                 case SHT_PROGBITS:
 890                 case SHT_NOBITS:
 891 #ifdef __amd64__
 892                 case SHT_X86_64_UNWIND:
 893 #endif
 894                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 895                                 break;
 896                         alignmask = shdr[i].sh_addralign - 1;
 897                         mapsize += alignmask;
 898                         mapsize &= ~alignmask;
 899                         mapsize += shdr[i].sh_size;
 900                         break;
 901                 }
 902         }
 903
 904         /*
 905          * We know how much space we need for the text/data/bss/etc.
 906          * This stuff needs to be in a single chunk so that profiling etc
 907          * can get the bounds and gdb can associate offsets with modules
 908          */
 909         ef->object = vm_object_allocate(OBJT_PHYS, atop(round_page(mapsize)));
 910         if (ef->object == NULL) {
 911                 error = ENOMEM;
 912                 goto out;
 913         }
 914
 915         /*
 916          * In order to satisfy amd64's architectural requirements on the
 917          * location of code and data in the kernel's address space, request a
 918          * mapping that is above the kernel.
 919          *
 920          * Protections will be restricted once relocations are applied.
 921          */
 922 #ifdef __amd64__
 923         mapbase = KERNBASE;
 924 #else
 925         mapbase = VM_MIN_KERNEL_ADDRESS;
 926 #endif
 927         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
 928             round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
 929             VM_PROT_ALL, 0);
 930         if (error != KERN_SUCCESS) {
 931                 vm_object_deallocate(ef->object);
 932                 ef->object = NULL;
 933                 error = ENOMEM;
 934                 goto out;
 935         }
 936
 937         /* Wire the pages */
 938         error = vm_map_wire(kernel_map, mapbase,
 939             mapbase + round_page(mapsize),
 940             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 941         if (error != KERN_SUCCESS) {
 942                 error = ENOMEM;
 943                 goto out;
 944         }
 945
 946         /* Inform the kld system about the situation */
 947         lf->address = ef->address = (caddr_t)mapbase;
 948         lf->size = mapsize;
 949
 950         /*
 951          * Now load code/data(progbits), zero bss(nobits), allocate space for
 952          * and load relocs
 953          */
 954         pb = 0;
 955         rl = 0;
 956         ra = 0;
 957         alignmask = 0;
 958         for (i = 0; i < hdr->e_shnum; i++) {
 959                 if (shdr[i].sh_size == 0)
 960                         continue;
 961                 switch (shdr[i].sh_type) {
 962                 case SHT_PROGBITS:
 963                 case SHT_NOBITS:
 964 #ifdef __amd64__
 965                 case SHT_X86_64_UNWIND:
 966 #endif
 967                         if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
 968                                 break;
 969                         alignmask = shdr[i].sh_addralign - 1;
 970                         mapbase += alignmask;
 971                         mapbase &= ~alignmask;
 972                         if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
 973                                 ef->progtab[pb].name =
 974                                     ef->shstrtab + shdr[i].sh_name;
 975                                 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
 976                                         lf->ctors_addr = (caddr_t)mapbase;
 977                                         lf->ctors_size = shdr[i].sh_size;
 978                                 }
 979                         } else if (shdr[i].sh_type == SHT_PROGBITS)
 980                                 ef->progtab[pb].name = "<<PROGBITS>>";
 981 #ifdef __amd64__
 982                         else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
 983                                 ef->progtab[pb].name = "<<UNWIND>>";
 984 #endif
 985                         else
 986                                 ef->progtab[pb].name = "<<NOBITS>>";
 987                         if (ef->progtab[pb].name != NULL &&
 988                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
 989                                 ef->progtab[pb].addr =
 990                                     dpcpu_alloc(shdr[i].sh_size);
 991                                 if (ef->progtab[pb].addr == NULL) {
 992                                         printf("%s: pcpu module space is out "
 993                                             "of space; cannot allocate %#jx "
 994                                             "for %s\n", __func__,
 995                                             (uintmax_t)shdr[i].sh_size,
 996                                             filename);
 997                                 }
 998                         }
 999 #ifdef VIMAGE
1000                         else if (ef->progtab[pb].name != NULL &&
1001                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
1002                                 ef->progtab[pb].addr =
1003                                     vnet_data_alloc(shdr[i].sh_size);
1004                                 if (ef->progtab[pb].addr == NULL) {
1005                                         printf("%s: vnet module space is out "
1006                                             "of space; cannot allocate %#jx "
1007                                             "for %s\n", __func__,
1008                                             (uintmax_t)shdr[i].sh_size,
1009                                             filename);
1010                                 }
1011                         }
1012 #endif
1013                         else
1014                                 ef->progtab[pb].addr =
1015                                     (void *)(uintptr_t)mapbase;
1016                         if (ef->progtab[pb].addr == NULL) {
1017                                 error = ENOSPC;
1018                                 goto out;
1019                         }
1020                         ef->progtab[pb].size = shdr[i].sh_size;
1021                         ef->progtab[pb].flags = shdr[i].sh_flags;
1022                         ef->progtab[pb].sec = i;
1023                         if (shdr[i].sh_type == SHT_PROGBITS
1024 #ifdef __amd64__
1025                             || shdr[i].sh_type == SHT_X86_64_UNWIND
1026 #endif
1027                             ) {
1028                                 error = vn_rdwr(UIO_READ, nd->ni_vp,
1029                                     ef->progtab[pb].addr,
1030                                     shdr[i].sh_size, shdr[i].sh_offset,
1031                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
1032                                     NOCRED, &resid, td);
1033                                 if (error)
1034                                         goto out;
1035                                 if (resid != 0){
1036                                         error = EINVAL;
1037                                         goto out;
1038                                 }
1039                                 /* Initialize the per-cpu or vnet area. */
1040                                 if (ef->progtab[pb].addr != (void *)mapbase &&
1041                                     !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
1042                                         dpcpu_copy(ef->progtab[pb].addr,
1043                                             shdr[i].sh_size);
1044 #ifdef VIMAGE
1045                                 else if (ef->progtab[pb].addr !=
1046                                     (void *)mapbase &&
1047                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
1048                                         vnet_data_copy(ef->progtab[pb].addr,
1049                                             shdr[i].sh_size);
1050 #endif
1051                         } else
1052                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
1053
1054                         /* Update all symbol values with the offset. */
1055                         for (j = 0; j < ef->ddbsymcnt; j++) {
1056                                 es = &ef->ddbsymtab[j];
1057                                 if (es->st_shndx != i)
1058                                         continue;
1059                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
1060                         }
1061                         mapbase += shdr[i].sh_size;
1062                         pb++;
1063                         break;
1064                 case SHT_REL:
1065                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
1066                                 break;
1067                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
1068                             M_WAITOK);
1069                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
1070                         ef->reltab[rl].sec = shdr[i].sh_info;
1071                         error = vn_rdwr(UIO_READ, nd->ni_vp,
1072                             (void *)ef->reltab[rl].rel,
1073                             shdr[i].sh_size, shdr[i].sh_offset,
1074                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1075                             &resid, td);
1076                         if (error)
1077                                 goto out;
1078                         if (resid != 0){
1079                                 error = EINVAL;
1080                                 goto out;
1081                         }
1082                         rl++;
1083                         break;
1084                 case SHT_RELA:
1085                         if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
1086                                 break;
1087                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
1088                             M_WAITOK);
1089                         ef->relatab[ra].nrela =
1090                             shdr[i].sh_size / sizeof(Elf_Rela);
1091                         ef->relatab[ra].sec = shdr[i].sh_info;
1092                         error = vn_rdwr(UIO_READ, nd->ni_vp,
1093                             (void *)ef->relatab[ra].rela,
1094                             shdr[i].sh_size, shdr[i].sh_offset,
1095                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1096                             &resid, td);
1097                         if (error)
1098                                 goto out;
1099                         if (resid != 0){
1100                                 error = EINVAL;
1101                                 goto out;
1102                         }
1103                         ra++;
1104                         break;
1105                 }
1106         }
1107         if (pb != ef->nprogtab) {
1108                 link_elf_error(filename, "lost progbits");
1109                 error = ENOEXEC;
1110                 goto out;
1111         }
1112         if (rl != ef->nreltab) {
1113                 link_elf_error(filename, "lost reltab");
1114                 error = ENOEXEC;
1115                 goto out;
1116         }
1117         if (ra != ef->nrelatab) {
1118                 link_elf_error(filename, "lost relatab");
1119                 error = ENOEXEC;
1120                 goto out;
1121         }
1122         if (mapbase != (vm_offset_t)ef->address + mapsize) {
1123                 printf(
1124                     "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
1125                     filename != NULL ? filename : "<none>",
1126                     (u_long)mapbase, ef->address, (u_long)mapsize,
1127                     (u_long)(vm_offset_t)ef->address + mapsize);
1128                 error = ENOMEM;
1129                 goto out;
1130         }
1131
1132         /* Local intra-module relocations */
1133         error = link_elf_reloc_local(lf, false);
1134         if (error != 0)
1135                 goto out;
1136
1137         /* Pull in dependencies */
1138         VOP_UNLOCK(nd->ni_vp);
1139         error = linker_load_dependencies(lf);
1140         vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY);
1141         if (error)
1142                 goto out;
1143
1144         /* External relocations */
1145         error = relocate_file(ef);
1146         if (error)
1147                 goto out;
1148
1149         /* Notify MD code that a module is being loaded. */
1150         error = elf_cpu_load_file(lf);
1151         if (error)
1152                 goto out;
1153
1154 #if defined(__i386__) || defined(__amd64__)
1155         /* Now ifuncs. */
1156         error = link_elf_reloc_local(lf, true);
1157         if (error != 0)
1158                 goto out;
1159 #endif
1160
1161         link_elf_protect(ef);
1162         link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
1163         *result = lf;
1164
1165 out:
1166         VOP_UNLOCK(nd->ni_vp);
1167         vn_close(nd->ni_vp, FREAD, td->td_ucred, td);
1168         free(nd, M_TEMP);
1169         if (error && lf)
1170                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1171         free(hdr, M_LINKER);
1172
1173         return error;
1174 }
1175
1176 static void
1177 link_elf_unload_file(linker_file_t file)
1178 {
1179         elf_file_t ef = (elf_file_t) file;
1180         u_int i;
1181
1182         /* Notify MD code that a module is being unloaded. */
1183         elf_cpu_unload_file(file);
1184
1185         if (ef->progtab) {
1186                 for (i = 0; i < ef->nprogtab; i++) {
1187                         if (ef->progtab[i].size == 0)
1188                                 continue;
1189                         if (ef->progtab[i].name == NULL)
1190                                 continue;
1191                         if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
1192                                 dpcpu_free(ef->progtab[i].addr,
1193                                     ef->progtab[i].size);
1194 #ifdef VIMAGE
1195                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
1196                                 vnet_data_free(ef->progtab[i].addr,
1197                                     ef->progtab[i].size);
1198 #endif
1199                 }
1200         }
1201         if (ef->preloaded) {
1202                 free(ef->reltab, M_LINKER);
1203                 free(ef->relatab, M_LINKER);
1204                 free(ef->progtab, M_LINKER);
1205                 free(ef->ctftab, M_LINKER);
1206                 free(ef->ctfoff, M_LINKER);
1207                 free(ef->typoff, M_LINKER);
1208                 if (file->pathname != NULL)
1209                         preload_delete_name(file->pathname);
1210                 return;
1211         }
1212
1213         for (i = 0; i < ef->nreltab; i++)
1214                 free(ef->reltab[i].rel, M_LINKER);
1215         for (i = 0; i < ef->nrelatab; i++)
1216                 free(ef->relatab[i].rela, M_LINKER);
1217         free(ef->reltab, M_LINKER);
1218         free(ef->relatab, M_LINKER);
1219         free(ef->progtab, M_LINKER);
1220
1221         if (ef->object != NULL)
1222                 vm_map_remove(kernel_map, (vm_offset_t)ef->address,
1223                     (vm_offset_t)ef->address + ptoa(ef->object->size));
1224         free(ef->e_shdr, M_LINKER);
1225         free(ef->ddbsymtab, M_LINKER);
1226         free(ef->ddbstrtab, M_LINKER);
1227         free(ef->shstrtab, M_LINKER);
1228         free(ef->ctftab, M_LINKER);
1229         free(ef->ctfoff, M_LINKER);
1230         free(ef->typoff, M_LINKER);
1231 }
1232
1233 static const char *
1234 symbol_name(elf_file_t ef, Elf_Size r_info)
1235 {
1236         const Elf_Sym *ref;
1237
1238         if (ELF_R_SYM(r_info)) {
1239                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1240                 return ef->ddbstrtab + ref->st_name;
1241         } else
1242                 return NULL;
1243 }
1244
1245 static Elf_Addr
1246 findbase(elf_file_t ef, int sec)
1247 {
1248         int i;
1249         Elf_Addr base = 0;
1250
1251         for (i = 0; i < ef->nprogtab; i++) {
1252                 if (sec == ef->progtab[i].sec) {
1253                         base = (Elf_Addr)ef->progtab[i].addr;
1254                         break;
1255                 }
1256         }
1257         return base;
1258 }
1259
1260 static int
1261 relocate_file(elf_file_t ef)
1262 {
1263         const Elf_Rel *rellim;
1264         const Elf_Rel *rel;
1265         const Elf_Rela *relalim;
1266         const Elf_Rela *rela;
1267         const char *symname;
1268         const Elf_Sym *sym;
1269         int i;
1270         Elf_Size symidx;
1271         Elf_Addr base;
1272
1273
1274         /* Perform relocations without addend if there are any: */
1275         for (i = 0; i < ef->nreltab; i++) {
1276                 rel = ef->reltab[i].rel;
1277                 if (rel == NULL) {
1278                         link_elf_error(ef->lf.filename, "lost a reltab!");
1279                         return (ENOEXEC);
1280                 }
1281                 rellim = rel + ef->reltab[i].nrel;
1282                 base = findbase(ef, ef->reltab[i].sec);
1283                 if (base == 0) {
1284                         link_elf_error(ef->lf.filename, "lost base for reltab");
1285                         return (ENOEXEC);
1286                 }
1287                 for ( ; rel < rellim; rel++) {
1288                         symidx = ELF_R_SYM(rel->r_info);
1289                         if (symidx >= ef->ddbsymcnt)
1290                                 continue;
1291                         sym = ef->ddbsymtab + symidx;
1292                         /* Local relocs are already done */
1293                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1294                                 continue;
1295                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1296                             elf_obj_lookup)) {
1297                                 symname = symbol_name(ef, rel->r_info);
1298                                 printf("link_elf_obj: symbol %s undefined\n",
1299                                     symname);
1300                                 return (ENOENT);
1301                         }
1302                 }
1303         }
1304
1305         /* Perform relocations with addend if there are any: */
1306         for (i = 0; i < ef->nrelatab; i++) {
1307                 rela = ef->relatab[i].rela;
1308                 if (rela == NULL) {
1309                         link_elf_error(ef->lf.filename, "lost a relatab!");
1310                         return (ENOEXEC);
1311                 }
1312                 relalim = rela + ef->relatab[i].nrela;
1313                 base = findbase(ef, ef->relatab[i].sec);
1314                 if (base == 0) {
1315                         link_elf_error(ef->lf.filename,
1316                             "lost base for relatab");
1317                         return (ENOEXEC);
1318                 }
1319                 for ( ; rela < relalim; rela++) {
1320                         symidx = ELF_R_SYM(rela->r_info);
1321                         if (symidx >= ef->ddbsymcnt)
1322                                 continue;
1323                         sym = ef->ddbsymtab + symidx;
1324                         /* Local relocs are already done */
1325                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1326                                 continue;
1327                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1328                             elf_obj_lookup)) {
1329                                 symname = symbol_name(ef, rela->r_info);
1330                                 printf("link_elf_obj: symbol %s undefined\n",
1331                                     symname);
1332                                 return (ENOENT);
1333                         }
1334                 }
1335         }
1336
1337         /*
1338          * Only clean SHN_FBSD_CACHED for successful return.  If we
1339          * modified symbol table for the object but found an
1340          * unresolved symbol, there is no reason to roll back.
1341          */
1342         elf_obj_cleanup_globals_cache(ef);
1343
1344         return (0);
1345 }
1346
1347 static int
1348 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1349 {
1350         elf_file_t ef = (elf_file_t) lf;
1351         const Elf_Sym *symp;
1352         const char *strp;
1353         int i;
1354
1355         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1356                 strp = ef->ddbstrtab + symp->st_name;
1357                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1358                         *sym = (c_linker_sym_t) symp;
1359                         return 0;
1360                 }
1361         }
1362         return ENOENT;
1363 }
1364
1365 static int
1366 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1367     linker_symval_t *symval)
1368 {
1369         elf_file_t ef;
1370         const Elf_Sym *es;
1371         caddr_t val;
1372
1373         ef = (elf_file_t) lf;
1374         es = (const Elf_Sym*) sym;
1375         val = (caddr_t)es->st_value;
1376         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1377                 symval->name = ef->ddbstrtab + es->st_name;
1378                 val = (caddr_t)es->st_value;
1379                 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1380                         val = ((caddr_t (*)(void))val)();
1381                 symval->value = val;
1382                 symval->size = es->st_size;
1383                 return 0;
1384         }
1385         return ENOENT;
1386 }
1387
1388 static int
1389 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1390     c_linker_sym_t *sym, long *diffp)
1391 {
1392         elf_file_t ef = (elf_file_t) lf;
1393         u_long off = (uintptr_t) (void *) value;
1394         u_long diff = off;
1395         u_long st_value;
1396         const Elf_Sym *es;
1397         const Elf_Sym *best = NULL;
1398         int i;
1399
1400         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1401                 if (es->st_name == 0)
1402                         continue;
1403                 st_value = es->st_value;
1404                 if (off >= st_value) {
1405                         if (off - st_value < diff) {
1406                                 diff = off - st_value;
1407                                 best = es;
1408                                 if (diff == 0)
1409                                         break;
1410                         } else if (off - st_value == diff) {
1411                                 best = es;
1412                         }
1413                 }
1414         }
1415         if (best == NULL)
1416                 *diffp = off;
1417         else
1418                 *diffp = diff;
1419         *sym = (c_linker_sym_t) best;
1420
1421         return 0;
1422 }
1423
1424 /*
1425  * Look up a linker set on an ELF system.
1426  */
1427 static int
1428 link_elf_lookup_set(linker_file_t lf, const char *name,
1429     void ***startp, void ***stopp, int *countp)
1430 {
1431         elf_file_t ef = (elf_file_t)lf;
1432         void **start, **stop;
1433         int i, count;
1434
1435         /* Relative to section number */
1436         for (i = 0; i < ef->nprogtab; i++) {
1437                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1438                     strcmp(ef->progtab[i].name + 4, name) == 0) {
1439                         start  = (void **)ef->progtab[i].addr;
1440                         stop = (void **)((char *)ef->progtab[i].addr +
1441                             ef->progtab[i].size);
1442                         count = stop - start;
1443                         if (startp)
1444                                 *startp = start;
1445                         if (stopp)
1446                                 *stopp = stop;
1447                         if (countp)
1448                                 *countp = count;
1449                         return (0);
1450                 }
1451         }
1452         return (ESRCH);
1453 }
1454
1455 static int
1456 link_elf_each_function_name(linker_file_t file,
1457     int (*callback)(const char *, void *), void *opaque)
1458 {
1459         elf_file_t ef = (elf_file_t)file;
1460         const Elf_Sym *symp;
1461         int i, error;
1462
1463         /* Exhaustive search */
1464         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1465                 if (symp->st_value != 0 &&
1466                     (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1467                     ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1468                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
1469                         if (error)
1470                                 return (error);
1471                 }
1472         }
1473         return (0);
1474 }
1475
1476 static int
1477 link_elf_each_function_nameval(linker_file_t file,
1478     linker_function_nameval_callback_t callback, void *opaque)
1479 {
1480         linker_symval_t symval;
1481         elf_file_t ef = (elf_file_t)file;
1482         const Elf_Sym* symp;
1483         int i, error;
1484
1485         /* Exhaustive search */
1486         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1487                 if (symp->st_value != 0 &&
1488                     (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1489                     ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1490                         error = link_elf_symbol_values(file,
1491                             (c_linker_sym_t)symp, &symval);
1492                         if (error)
1493                                 return (error);
1494                         error = callback(file, i, &symval, opaque);
1495                         if (error)
1496                                 return (error);
1497                 }
1498         }
1499         return (0);
1500 }
1501
1502 static void
1503 elf_obj_cleanup_globals_cache(elf_file_t ef)
1504 {
1505         Elf_Sym *sym;
1506         Elf_Size i;
1507
1508         for (i = 0; i < ef->ddbsymcnt; i++) {
1509                 sym = ef->ddbsymtab + i;
1510                 if (sym->st_shndx == SHN_FBSD_CACHED) {
1511                         sym->st_shndx = SHN_UNDEF;
1512                         sym->st_value = 0;
1513                 }
1514         }
1515 }
1516
1517 /*
1518  * Symbol lookup function that can be used when the symbol index is known (ie
1519  * in relocations). It uses the symbol index instead of doing a fully fledged
1520  * hash table based lookup when such is valid. For example for local symbols.
1521  * This is not only more efficient, it's also more correct. It's not always
1522  * the case that the symbol can be found through the hash table.
1523  */
1524 static int
1525 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1526 {
1527         elf_file_t ef = (elf_file_t)lf;
1528         Elf_Sym *sym;
1529         const char *symbol;
1530         Elf_Addr res1;
1531
1532         /* Don't even try to lookup the symbol if the index is bogus. */
1533         if (symidx >= ef->ddbsymcnt) {
1534                 *res = 0;
1535                 return (EINVAL);
1536         }
1537
1538         sym = ef->ddbsymtab + symidx;
1539
1540         /* Quick answer if there is a definition included. */
1541         if (sym->st_shndx != SHN_UNDEF) {
1542                 res1 = (Elf_Addr)sym->st_value;
1543                 if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC)
1544                         res1 = ((Elf_Addr (*)(void))res1)();
1545                 *res = res1;
1546                 return (0);
1547         }
1548
1549         /* If we get here, then it is undefined and needs a lookup. */
1550         switch (ELF_ST_BIND(sym->st_info)) {
1551         case STB_LOCAL:
1552                 /* Local, but undefined? huh? */
1553                 *res = 0;
1554                 return (EINVAL);
1555
1556         case STB_GLOBAL:
1557         case STB_WEAK:
1558                 /* Relative to Data or Function name */
1559                 symbol = ef->ddbstrtab + sym->st_name;
1560
1561                 /* Force a lookup failure if the symbol name is bogus. */
1562                 if (*symbol == 0) {
1563                         *res = 0;
1564                         return (EINVAL);
1565                 }
1566                 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1567
1568                 /*
1569                  * Cache global lookups during module relocation. The failure
1570                  * case is particularly expensive for callers, who must scan
1571                  * through the entire globals table doing strcmp(). Cache to
1572                  * avoid doing such work repeatedly.
1573                  *
1574                  * After relocation is complete, undefined globals will be
1575                  * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1576                  * above.
1577                  */
1578                 if (res1 != 0) {
1579                         sym->st_shndx = SHN_FBSD_CACHED;
1580                         sym->st_value = res1;
1581                         *res = res1;
1582                         return (0);
1583                 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1584                         sym->st_value = 0;
1585                         *res = 0;
1586                         return (0);
1587                 }
1588                 return (EINVAL);
1589
1590         default:
1591                 return (EINVAL);
1592         }
1593 }
1594
1595 static void
1596 link_elf_fix_link_set(elf_file_t ef)
1597 {
1598         static const char startn[] = "__start_";
1599         static const char stopn[] = "__stop_";
1600         Elf_Sym *sym;
1601         const char *sym_name, *linkset_name;
1602         Elf_Addr startp, stopp;
1603         Elf_Size symidx;
1604         int start, i;
1605
1606         startp = stopp = 0;
1607         for (symidx = 1 /* zero entry is special */;
1608                 symidx < ef->ddbsymcnt; symidx++) {
1609                 sym = ef->ddbsymtab + symidx;
1610                 if (sym->st_shndx != SHN_UNDEF)
1611                         continue;
1612
1613                 sym_name = ef->ddbstrtab + sym->st_name;
1614                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1615                         start = 1;
1616                         linkset_name = sym_name + sizeof(startn) - 1;
1617                 }
1618                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1619                         start = 0;
1620                         linkset_name = sym_name + sizeof(stopn) - 1;
1621                 }
1622                 else
1623                         continue;
1624
1625                 for (i = 0; i < ef->nprogtab; i++) {
1626                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1627                                 startp = (Elf_Addr)ef->progtab[i].addr;
1628                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1629                                 break;
1630                         }
1631                 }
1632                 if (i == ef->nprogtab)
1633                         continue;
1634
1635                 sym->st_value = start ? startp : stopp;
1636                 sym->st_shndx = i;
1637         }
1638 }
1639
1640 static int
1641 link_elf_reloc_local(linker_file_t lf, bool ifuncs)
1642 {
1643         elf_file_t ef = (elf_file_t)lf;
1644         const Elf_Rel *rellim;
1645         const Elf_Rel *rel;
1646         const Elf_Rela *relalim;
1647         const Elf_Rela *rela;
1648         const Elf_Sym *sym;
1649         Elf_Addr base;
1650         int i;
1651         Elf_Size symidx;
1652
1653         link_elf_fix_link_set(ef);
1654
1655         /* Perform relocations without addend if there are any: */
1656         for (i = 0; i < ef->nreltab; i++) {
1657                 rel = ef->reltab[i].rel;
1658                 if (rel == NULL) {
1659                         link_elf_error(ef->lf.filename, "lost a reltab");
1660                         return (ENOEXEC);
1661                 }
1662                 rellim = rel + ef->reltab[i].nrel;
1663                 base = findbase(ef, ef->reltab[i].sec);
1664                 if (base == 0) {
1665                         link_elf_error(ef->lf.filename, "lost base for reltab");
1666                         return (ENOEXEC);
1667                 }
1668                 for ( ; rel < rellim; rel++) {
1669                         symidx = ELF_R_SYM(rel->r_info);
1670                         if (symidx >= ef->ddbsymcnt)
1671                                 continue;
1672                         sym = ef->ddbsymtab + symidx;
1673                         /* Only do local relocs */
1674                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1675                                 continue;
1676                         if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1677                             elf_is_ifunc_reloc(rel->r_info)) == ifuncs)
1678                                 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1679                                     elf_obj_lookup);
1680                 }
1681         }
1682
1683         /* Perform relocations with addend if there are any: */
1684         for (i = 0; i < ef->nrelatab; i++) {
1685                 rela = ef->relatab[i].rela;
1686                 if (rela == NULL) {
1687                         link_elf_error(ef->lf.filename, "lost a relatab!");
1688                         return (ENOEXEC);
1689                 }
1690                 relalim = rela + ef->relatab[i].nrela;
1691                 base = findbase(ef, ef->relatab[i].sec);
1692                 if (base == 0) {
1693                         link_elf_error(ef->lf.filename, "lost base for reltab");
1694                         return (ENOEXEC);
1695                 }
1696                 for ( ; rela < relalim; rela++) {
1697                         symidx = ELF_R_SYM(rela->r_info);
1698                         if (symidx >= ef->ddbsymcnt)
1699                                 continue;
1700                         sym = ef->ddbsymtab + symidx;
1701                         /* Only do local relocs */
1702                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1703                                 continue;
1704                         if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1705                             elf_is_ifunc_reloc(rela->r_info)) == ifuncs)
1706                                 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1707                                     elf_obj_lookup);
1708                 }
1709         }
1710         return (0);
1711 }
1712
1713 static long
1714 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1715 {
1716     elf_file_t ef = (elf_file_t)lf;
1717
1718     *symtab = ef->ddbsymtab;
1719
1720     if (*symtab == NULL)
1721         return (0);
1722
1723     return (ef->ddbsymcnt);
1724 }
1725
1726 static long
1727 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1728 {
1729     elf_file_t ef = (elf_file_t)lf;
1730
1731     *strtab = ef->ddbstrtab;
1732
1733     if (*strtab == NULL)
1734         return (0);
1735
1736     return (ef->ddbstrcnt);
1737 }