sysdeps/i386/dl-machine.h

   1 /* Machine-dependent ELF dynamic relocation inline functions.  i386 version.
   2    Copyright (C) 1995-2013 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef dl_machine_h
  20 #define dl_machine_h
  21
  22 #define ELF_MACHINE_NAME "i386"
  23
  24 #include <sys/param.h>
  25 #include <sysdep.h>
  26 #include <tls.h>
  27 #include <dl-tlsdesc.h>
  28
  29 /* Return nonzero iff ELF header is compatible with the running host.  */
  30 static inline int __attribute__ ((unused))
  31 elf_machine_matches_host (const Elf32_Ehdr *ehdr)
  32 {
  33   return ehdr->e_machine == EM_386;
  34 }
  35
  36
  37 #ifdef PI_STATIC_AND_HIDDEN
  38
  39 /* Return the link-time address of _DYNAMIC.  Conveniently, this is the
  40    first element of the GOT, a special entry that is never relocated.  */
  41 static inline Elf32_Addr __attribute__ ((unused, const))
  42 elf_machine_dynamic (void)
  43 {
  44   /* This produces a GOTOFF reloc that resolves to zero at link time, so in
  45      fact just loads from the GOT register directly.  By doing it without
  46      an asm we can let the compiler choose any register.  */
  47   extern const Elf32_Addr _GLOBAL_OFFSET_TABLE_[] attribute_hidden;
  48   return _GLOBAL_OFFSET_TABLE_[0];
  49 }
  50
  51 /* Return the run-time load address of the shared object.  */
  52 static inline Elf32_Addr __attribute__ ((unused))
  53 elf_machine_load_address (void)
  54 {
  55   /* Compute the difference between the runtime address of _DYNAMIC as seen
  56      by a GOTOFF reference, and the link-time address found in the special
  57      unrelocated first GOT entry.  */
  58   extern Elf32_Dyn bygotoff[] asm ("_DYNAMIC") attribute_hidden;
  59   return (Elf32_Addr) &bygotoff - elf_machine_dynamic ();
  60 }
  61
  62 #else  /* Without .hidden support, we can't compile the code above.  */
  63
  64 /* Return the link-time address of _DYNAMIC.  Conveniently, this is the
  65    first element of the GOT.  This must be inlined in a function which
  66    uses global data.  */
  67 static inline Elf32_Addr __attribute__ ((unused))
  68 elf_machine_dynamic (void)
  69 {
  70   register Elf32_Addr *got asm ("%ebx");
  71   return *got;
  72 }
  73
  74
  75 /* Return the run-time load address of the shared object.  */
  76 static inline Elf32_Addr __attribute__ ((unused))
  77 elf_machine_load_address (void)
  78 {
  79   /* It doesn't matter what variable this is, the reference never makes
  80      it to assembly.  We need a dummy reference to some global variable
  81      via the GOT to make sure the compiler initialized %ebx in time.  */
  82   extern int _dl_argc;
  83   Elf32_Addr addr;
  84   asm ("leal _dl_start@GOTOFF(%%ebx), %0\n"
  85        "subl _dl_start@GOT(%%ebx), %0"
  86        : "=r" (addr) : "m" (_dl_argc) : "cc");
  87   return addr;
  88 }
  89
  90 #endif
  91
  92
  93 /* Set up the loaded object described by L so its unrelocated PLT
  94    entries will jump to the on-demand fixup code in dl-runtime.c.  */
  95
  96 static inline int __attribute__ ((unused, always_inline))
  97 elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
  98 {
  99   Elf32_Addr *got;
 100   extern void _dl_runtime_resolve (Elf32_Word) attribute_hidden;
 101   extern void _dl_runtime_profile (Elf32_Word) attribute_hidden;
 102
 103   if (l->l_info[DT_JMPREL] && lazy)
 104     {
 105       /* The GOT entries for functions in the PLT have not yet been filled
 106          in.  Their initial contents will arrange when called to push an
 107          offset into the .rel.plt section, push _GLOBAL_OFFSET_TABLE_[1],
 108          and then jump to _GLOBAL_OFFSET_TABLE[2].  */
 109       got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
 110       /* If a library is prelinked but we have to relocate anyway,
 111          we have to be able to undo the prelinking of .got.plt.
 112          The prelinker saved us here address of .plt + 0x16.  */
 113       if (got[1])
 114         {
 115           l->l_mach.plt = got[1] + l->l_addr;
 116           l->l_mach.gotplt = (Elf32_Addr) &got[3];
 117         }
 118       got[1] = (Elf32_Addr) l;  /* Identify this shared object.  */
 119
 120       /* The got[2] entry contains the address of a function which gets
 121          called to get the address of a so far unresolved function and
 122          jump to it.  The profiling extension of the dynamic linker allows
 123          to intercept the calls to collect information.  In this case we
 124          don't store the address in the GOT so that all future calls also
 125          end in this function.  */
 126       if (__builtin_expect (profile, 0))
 127         {
 128           got[2] = (Elf32_Addr) &_dl_runtime_profile;
 129
 130           if (GLRO(dl_profile) != NULL
 131               && _dl_name_match_p (GLRO(dl_profile), l))
 132             /* This is the object we are looking for.  Say that we really
 133                want profiling and the timers are started.  */
 134             GL(dl_profile_map) = l;
 135         }
 136       else
 137         /* This function will get called to fix up the GOT entry indicated by
 138            the offset on the stack, and then jump to the resolved address.  */
 139         got[2] = (Elf32_Addr) &_dl_runtime_resolve;
 140     }
 141
 142   return lazy;
 143 }
 144
 145 #ifdef IN_DL_RUNTIME
 146
 147 # ifndef PROF
 148 /* We add a declaration of this function here so that in dl-runtime.c
 149    the ELF_MACHINE_RUNTIME_TRAMPOLINE macro really can pass the parameters
 150    in registers.
 151
 152    We cannot use this scheme for profiling because the _mcount call
 153    destroys the passed register information.  */
 154 #define ARCH_FIXUP_ATTRIBUTE __attribute__ ((regparm (3), stdcall, unused))
 155
 156 extern ElfW(Addr) _dl_fixup (struct link_map *l,
 157                              ElfW(Word) reloc_offset)
 158      ARCH_FIXUP_ATTRIBUTE;
 159 extern ElfW(Addr) _dl_profile_fixup (struct link_map *l,
 160                                      ElfW(Word) reloc_offset,
 161                                      ElfW(Addr) retaddr, void *regs,
 162                                      long int *framesizep)
 163      ARCH_FIXUP_ATTRIBUTE;
 164 # endif
 165
 166 #endif
 167
 168 /* Mask identifying addresses reserved for the user program,
 169    where the dynamic linker should not map anything.  */
 170 #define ELF_MACHINE_USER_ADDRESS_MASK   0xf8000000UL
 171
 172 /* Initial entry point code for the dynamic linker.
 173    The C function `_dl_start' is the real entry point;
 174    its return value is the user program's entry point.  */
 175
 176 #define RTLD_START asm ("\n\
 177         .text\n\
 178         .align 16\n\
 179 0:      movl (%esp), %ebx\n\
 180         ret\n\
 181         .align 16\n\
 182 .globl _start\n\
 183 .globl _dl_start_user\n\
 184 _start:\n\
 185         # Note that _dl_start gets the parameter in %eax.\n\
 186         movl %esp, %eax\n\
 187         call _dl_start\n\
 188 _dl_start_user:\n\
 189         # Save the user entry point address in %edi.\n\
 190         movl %eax, %edi\n\
 191         # Point %ebx at the GOT.\n\
 192         call 0b\n\
 193         addl $_GLOBAL_OFFSET_TABLE_, %ebx\n\
 194         # See if we were run as a command with the executable file\n\
 195         # name as an extra leading argument.\n\
 196         movl _dl_skip_args@GOTOFF(%ebx), %eax\n\
 197         # Pop the original argument count.\n\
 198         popl %edx\n\
 199         # Adjust the stack pointer to skip _dl_skip_args words.\n\
 200         leal (%esp,%eax,4), %esp\n\
 201         # Subtract _dl_skip_args from argc.\n\
 202         subl %eax, %edx\n\
 203         # Push argc back on the stack.\n\
 204         push %edx\n\
 205         # The special initializer gets called with the stack just\n\
 206         # as the application's entry point will see it; it can\n\
 207         # switch stacks if it moves these contents over.\n\
 208 " RTLD_START_SPECIAL_INIT "\n\
 209         # Load the parameters again.\n\
 210         # (eax, edx, ecx, *--esp) = (_dl_loaded, argc, argv, envp)\n\
 211         movl _rtld_local@GOTOFF(%ebx), %eax\n\
 212         leal 8(%esp,%edx,4), %esi\n\
 213         leal 4(%esp), %ecx\n\
 214         movl %esp, %ebp\n\
 215         # Make sure _dl_init is run with 16 byte aligned stack.\n\
 216         andl $-16, %esp\n\
 217         pushl %eax\n\
 218         pushl %eax\n\
 219         pushl %ebp\n\
 220         pushl %esi\n\
 221         # Clear %ebp, so that even constructors have terminated backchain.\n\
 222         xorl %ebp, %ebp\n\
 223         # Call the function to run the initializers.\n\
 224         call _dl_init_internal@PLT\n\
 225         # Pass our finalizer function to the user in %edx, as per ELF ABI.\n\
 226         leal _dl_fini@GOTOFF(%ebx), %edx\n\
 227         # Restore %esp _start expects.\n\
 228         movl (%esp), %esp\n\
 229         # Jump to the user's entry point.\n\
 230         jmp *%edi\n\
 231         .previous\n\
 232 ");
 233
 234 #ifndef RTLD_START_SPECIAL_INIT
 235 # define RTLD_START_SPECIAL_INIT /* nothing */
 236 #endif
 237
 238 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or
 239    TLS variable, so undefined references should not be allowed to
 240    define the value.
 241    ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
 242    of the main executable's symbols, as for a COPY reloc.  */
 243 # define elf_machine_type_class(type) \
 244   ((((type) == R_386_JMP_SLOT || (type) == R_386_TLS_DTPMOD32                 \
 245      || (type) == R_386_TLS_DTPOFF32 || (type) == R_386_TLS_TPOFF32           \
 246      || (type) == R_386_TLS_TPOFF || (type) == R_386_TLS_DESC)                \
 247     * ELF_RTYPE_CLASS_PLT)                                                    \
 248    | (((type) == R_386_COPY) * ELF_RTYPE_CLASS_COPY))
 249
 250 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.  */
 251 #define ELF_MACHINE_JMP_SLOT    R_386_JMP_SLOT
 252
 253 /* The i386 never uses Elf32_Rela relocations for the dynamic linker.
 254    Prelinked libraries may use Elf32_Rela though.  */
 255 #define ELF_MACHINE_PLT_REL 1
 256
 257 /* We define an initialization functions.  This is called very early in
 258    _dl_sysdep_start.  */
 259 #define DL_PLATFORM_INIT dl_platform_init ()
 260
 261 static inline void __attribute__ ((unused))
 262 dl_platform_init (void)
 263 {
 264   if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
 265     /* Avoid an empty string which would disturb us.  */
 266     GLRO(dl_platform) = NULL;
 267 }
 268
 269 static inline Elf32_Addr
 270 elf_machine_fixup_plt (struct link_map *map, lookup_t t,
 271                        const Elf32_Rel *reloc,
 272                        Elf32_Addr *reloc_addr, Elf32_Addr value)
 273 {
 274   return *reloc_addr = value;
 275 }
 276
 277 /* Return the final value of a plt relocation.  */
 278 static inline Elf32_Addr
 279 elf_machine_plt_value (struct link_map *map, const Elf32_Rel *reloc,
 280                        Elf32_Addr value)
 281 {
 282   return value;
 283 }
 284
 285
 286 /* Names of the architecture-specific auditing callback functions.  */
 287 #define ARCH_LA_PLTENTER i86_gnu_pltenter
 288 #define ARCH_LA_PLTEXIT i86_gnu_pltexit
 289
 290 #endif /* !dl_machine_h */
 291
 292 /* The i386 never uses Elf32_Rela relocations for the dynamic linker.
 293    Prelinked libraries may use Elf32_Rela though.  */
 294 #define ELF_MACHINE_NO_RELA defined RTLD_BOOTSTRAP
 295
 296 #ifdef RESOLVE_MAP
 297
 298 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
 299    MAP is the object containing the reloc.  */
 300
 301 auto inline void
 302 __attribute ((always_inline))
 303 elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc,
 304                  const Elf32_Sym *sym, const struct r_found_version *version,
 305                  void *const reloc_addr_arg, int skip_ifunc)
 306 {
 307   Elf32_Addr *const reloc_addr = reloc_addr_arg;
 308   const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
 309
 310 # if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC
 311   if (__builtin_expect (r_type == R_386_RELATIVE, 0))
 312     {
 313 #  if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
 314       /* This is defined in rtld.c, but nowhere in the static libc.a;
 315          make the reference weak so static programs can still link.
 316          This declaration cannot be done when compiling rtld.c
 317          (i.e. #ifdef RTLD_BOOTSTRAP) because rtld.c contains the
 318          common defn for _dl_rtld_map, which is incompatible with a
 319          weak decl in the same file.  */
 320 #   ifndef SHARED
 321       weak_extern (_dl_rtld_map);
 322 #   endif
 323       if (map != &GL(dl_rtld_map)) /* Already done in rtld itself.  */
 324 #  endif
 325         *reloc_addr += map->l_addr;
 326     }
 327 #  ifndef RTLD_BOOTSTRAP
 328   else if (__builtin_expect (r_type == R_386_NONE, 0))
 329     return;
 330 #  endif
 331   else
 332 # endif /* !RTLD_BOOTSTRAP and have no -z combreloc */
 333     {
 334 # ifndef RTLD_BOOTSTRAP
 335       const Elf32_Sym *const refsym = sym;
 336 # endif
 337       struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
 338       Elf32_Addr value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
 339
 340       if (sym != NULL
 341           && __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC,
 342                                0)
 343           && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
 344           && __builtin_expect (!skip_ifunc, 1))
 345         value = ((Elf32_Addr (*) (void)) value) ();
 346
 347       switch (r_type)
 348         {
 349 # ifndef RTLD_BOOTSTRAP
 350         case R_386_SIZE32:
 351           /* Set to symbol size plus addend.  */
 352           *reloc_addr += sym->st_size;
 353           break;
 354 # endif
 355         case R_386_GLOB_DAT:
 356         case R_386_JMP_SLOT:
 357           *reloc_addr = value;
 358           break;
 359
 360         case R_386_TLS_DTPMOD32:
 361 # ifdef RTLD_BOOTSTRAP
 362           /* During startup the dynamic linker is always the module
 363              with index 1.
 364              XXX If this relocation is necessary move before RESOLVE
 365              call.  */
 366           *reloc_addr = 1;
 367 # else
 368           /* Get the information from the link map returned by the
 369              resolv function.  */
 370           if (sym_map != NULL)
 371             *reloc_addr = sym_map->l_tls_modid;
 372 # endif
 373           break;
 374         case R_386_TLS_DTPOFF32:
 375 # ifndef RTLD_BOOTSTRAP
 376           /* During relocation all TLS symbols are defined and used.
 377              Therefore the offset is already correct.  */
 378           if (sym != NULL)
 379             *reloc_addr = sym->st_value;
 380 # endif
 381           break;
 382         case R_386_TLS_DESC:
 383           {
 384             struct tlsdesc volatile *td =
 385               (struct tlsdesc volatile *)reloc_addr;
 386
 387 # ifndef RTLD_BOOTSTRAP
 388             if (! sym)
 389               td->entry = _dl_tlsdesc_undefweak;
 390             else
 391 # endif
 392               {
 393 # ifndef RTLD_BOOTSTRAP
 394 #  ifndef SHARED
 395                 CHECK_STATIC_TLS (map, sym_map);
 396 #  else
 397                 if (!TRY_STATIC_TLS (map, sym_map))
 398                   {
 399                     td->arg = _dl_make_tlsdesc_dynamic
 400                       (sym_map, sym->st_value + (ElfW(Word))td->arg);
 401                     td->entry = _dl_tlsdesc_dynamic;
 402                   }
 403                 else
 404 #  endif
 405 # endif
 406                   {
 407                     td->arg = (void*)(sym->st_value - sym_map->l_tls_offset
 408                                       + (ElfW(Word))td->arg);
 409                     td->entry = _dl_tlsdesc_return;
 410                   }
 411               }
 412             break;
 413           }
 414         case R_386_TLS_TPOFF32:
 415           /* The offset is positive, backward from the thread pointer.  */
 416 #  ifdef RTLD_BOOTSTRAP
 417           *reloc_addr += map->l_tls_offset - sym->st_value;
 418 #  else
 419           /* We know the offset of object the symbol is contained in.
 420              It is a positive value which will be subtracted from the
 421              thread pointer.  To get the variable position in the TLS
 422              block we subtract the offset from that of the TLS block.  */
 423           if (sym != NULL)
 424             {
 425               CHECK_STATIC_TLS (map, sym_map);
 426               *reloc_addr += sym_map->l_tls_offset - sym->st_value;
 427             }
 428 # endif
 429           break;
 430         case R_386_TLS_TPOFF:
 431           /* The offset is negative, forward from the thread pointer.  */
 432 # ifdef RTLD_BOOTSTRAP
 433           *reloc_addr += sym->st_value - map->l_tls_offset;
 434 # else
 435           /* We know the offset of object the symbol is contained in.
 436              It is a negative value which will be added to the
 437              thread pointer.  */
 438           if (sym != NULL)
 439             {
 440               CHECK_STATIC_TLS (map, sym_map);
 441               *reloc_addr += sym->st_value - sym_map->l_tls_offset;
 442             }
 443 # endif
 444           break;
 445
 446 # ifndef RTLD_BOOTSTRAP
 447         case R_386_32:
 448           *reloc_addr += value;
 449           break;
 450         case R_386_PC32:
 451           *reloc_addr += (value - (Elf32_Addr) reloc_addr);
 452           break;
 453         case R_386_COPY:
 454           if (sym == NULL)
 455             /* This can happen in trace mode if an object could not be
 456                found.  */
 457             break;
 458           if (__builtin_expect (sym->st_size > refsym->st_size, 0)
 459               || (__builtin_expect (sym->st_size < refsym->st_size, 0)
 460                   && GLRO(dl_verbose)))
 461             {
 462               const char *strtab;
 463
 464               strtab = (const char *) D_PTR (map, l_info[DT_STRTAB]);
 465               _dl_error_printf ("\
 466 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
 467                                 rtld_progname ?: "<program name unknown>",
 468                                 strtab + refsym->st_name);
 469             }
 470           memcpy (reloc_addr_arg, (void *) value,
 471                   MIN (sym->st_size, refsym->st_size));
 472           break;
 473         case R_386_IRELATIVE:
 474           value = map->l_addr + *reloc_addr;
 475           value = ((Elf32_Addr (*) (void)) value) ();
 476           *reloc_addr = value;
 477           break;
 478         default:
 479           _dl_reloc_bad_type (map, r_type, 0);
 480           break;
 481 # endif /* !RTLD_BOOTSTRAP */
 482         }
 483     }
 484 }
 485
 486 # ifndef RTLD_BOOTSTRAP
 487 auto inline void
 488 __attribute__ ((always_inline))
 489 elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
 490                   const Elf32_Sym *sym, const struct r_found_version *version,
 491                   void *const reloc_addr_arg, int skip_ifunc)
 492 {
 493   Elf32_Addr *const reloc_addr = reloc_addr_arg;
 494   const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
 495
 496   if (ELF32_R_TYPE (reloc->r_info) == R_386_RELATIVE)
 497     *reloc_addr = map->l_addr + reloc->r_addend;
 498   else if (r_type != R_386_NONE)
 499     {
 500 #  ifndef RESOLVE_CONFLICT_FIND_MAP
 501       const Elf32_Sym *const refsym = sym;
 502 #  endif
 503       struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
 504       Elf32_Addr value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value;
 505
 506       if (sym != NULL
 507           && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
 508           && __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC, 0)
 509           && __builtin_expect (!skip_ifunc, 1))
 510         value = ((Elf32_Addr (*) (void)) value) ();
 511
 512       switch (ELF32_R_TYPE (reloc->r_info))
 513         {
 514         case R_386_SIZE32:
 515           /* Set to symbol size plus addend.  */
 516           value = sym->st_size;
 517         case R_386_GLOB_DAT:
 518         case R_386_JMP_SLOT:
 519         case R_386_32:
 520           *reloc_addr = value + reloc->r_addend;
 521           break;
 522 #  ifndef RESOLVE_CONFLICT_FIND_MAP
 523           /* Not needed for dl-conflict.c.  */
 524         case R_386_PC32:
 525           *reloc_addr = (value + reloc->r_addend - (Elf32_Addr) reloc_addr);
 526           break;
 527
 528         case R_386_TLS_DTPMOD32:
 529           /* Get the information from the link map returned by the
 530              resolv function.  */
 531           if (sym_map != NULL)
 532             *reloc_addr = sym_map->l_tls_modid;
 533           break;
 534         case R_386_TLS_DTPOFF32:
 535           /* During relocation all TLS symbols are defined and used.
 536              Therefore the offset is already correct.  */
 537           *reloc_addr = (sym == NULL ? 0 : sym->st_value) + reloc->r_addend;
 538           break;
 539         case R_386_TLS_DESC:
 540           {
 541             struct tlsdesc volatile *td =
 542               (struct tlsdesc volatile *)reloc_addr;
 543
 544 #   ifndef RTLD_BOOTSTRAP
 545             if (!sym)
 546               {
 547                 td->arg = (void*)reloc->r_addend;
 548                 td->entry = _dl_tlsdesc_undefweak;
 549               }
 550             else
 551 #   endif
 552               {
 553 #   ifndef RTLD_BOOTSTRAP
 554 #    ifndef SHARED
 555                 CHECK_STATIC_TLS (map, sym_map);
 556 #    else
 557                 if (!TRY_STATIC_TLS (map, sym_map))
 558                   {
 559                     td->arg = _dl_make_tlsdesc_dynamic
 560                       (sym_map, sym->st_value + reloc->r_addend);
 561                     td->entry = _dl_tlsdesc_dynamic;
 562                   }
 563                 else
 564 #    endif
 565 #   endif
 566                   {
 567                     td->arg = (void*)(sym->st_value - sym_map->l_tls_offset
 568                                       + reloc->r_addend);
 569                     td->entry = _dl_tlsdesc_return;
 570                   }
 571               }
 572           }
 573           break;
 574         case R_386_TLS_TPOFF32:
 575           /* The offset is positive, backward from the thread pointer.  */
 576           /* We know the offset of object the symbol is contained in.
 577              It is a positive value which will be subtracted from the
 578              thread pointer.  To get the variable position in the TLS
 579              block we subtract the offset from that of the TLS block.  */
 580           if (sym != NULL)
 581             {
 582               CHECK_STATIC_TLS (map, sym_map);
 583               *reloc_addr = sym_map->l_tls_offset - sym->st_value
 584                             + reloc->r_addend;
 585             }
 586           break;
 587         case R_386_TLS_TPOFF:
 588           /* The offset is negative, forward from the thread pointer.  */
 589           /* We know the offset of object the symbol is contained in.
 590              It is a negative value which will be added to the
 591              thread pointer.  */
 592           if (sym != NULL)
 593             {
 594               CHECK_STATIC_TLS (map, sym_map);
 595               *reloc_addr = sym->st_value - sym_map->l_tls_offset
 596                             + reloc->r_addend;
 597             }
 598           break;
 599         case R_386_COPY:
 600           if (sym == NULL)
 601             /* This can happen in trace mode if an object could not be
 602                found.  */
 603             break;
 604           if (__builtin_expect (sym->st_size > refsym->st_size, 0)
 605               || (__builtin_expect (sym->st_size < refsym->st_size, 0)
 606                   && GLRO(dl_verbose)))
 607             {
 608               const char *strtab;
 609
 610               strtab = (const char *) D_PTR (map, l_info[DT_STRTAB]);
 611               _dl_error_printf ("\
 612 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
 613                                 rtld_progname ?: "<program name unknown>",
 614                                 strtab + refsym->st_name);
 615             }
 616           memcpy (reloc_addr_arg, (void *) value,
 617                   MIN (sym->st_size, refsym->st_size));
 618           break;
 619 #  endif /* !RESOLVE_CONFLICT_FIND_MAP */
 620         case R_386_IRELATIVE:
 621           value = map->l_addr + reloc->r_addend;
 622           value = ((Elf32_Addr (*) (void)) value) ();
 623           *reloc_addr = value;
 624           break;
 625         default:
 626           /* We add these checks in the version to relocate ld.so only
 627              if we are still debugging.  */
 628           _dl_reloc_bad_type (map, r_type, 0);
 629           break;
 630         }
 631     }
 632 }
 633 # endif /* !RTLD_BOOTSTRAP */
 634
 635 auto inline void
 636 __attribute ((always_inline))
 637 elf_machine_rel_relative (Elf32_Addr l_addr, const Elf32_Rel *reloc,
 638                           void *const reloc_addr_arg)
 639 {
 640   Elf32_Addr *const reloc_addr = reloc_addr_arg;
 641   assert (ELF32_R_TYPE (reloc->r_info) == R_386_RELATIVE);
 642   *reloc_addr += l_addr;
 643 }
 644
 645 # ifndef RTLD_BOOTSTRAP
 646 auto inline void
 647 __attribute__ ((always_inline))
 648 elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc,
 649                            void *const reloc_addr_arg)
 650 {
 651   Elf32_Addr *const reloc_addr = reloc_addr_arg;
 652   *reloc_addr = l_addr + reloc->r_addend;
 653 }
 654 # endif /* !RTLD_BOOTSTRAP */
 655
 656 auto inline void
 657 __attribute__ ((always_inline))
 658 elf_machine_lazy_rel (struct link_map *map,
 659                       Elf32_Addr l_addr, const Elf32_Rel *reloc,
 660                       int skip_ifunc)
 661 {
 662   Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
 663   const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
 664   /* Check for unexpected PLT reloc type.  */
 665   if (__builtin_expect (r_type == R_386_JMP_SLOT, 1))
 666     {
 667       if (__builtin_expect (map->l_mach.plt, 0) == 0)
 668         *reloc_addr += l_addr;
 669       else
 670         *reloc_addr = (map->l_mach.plt
 671                        + (((Elf32_Addr) reloc_addr) - map->l_mach.gotplt) * 4);
 672     }
 673   else if (__builtin_expect (r_type == R_386_TLS_DESC, 1))
 674     {
 675       struct tlsdesc volatile * __attribute__((__unused__)) td =
 676         (struct tlsdesc volatile *)reloc_addr;
 677
 678       /* Handle relocations that reference the local *ABS* in a simple
 679          way, so as to preserve a potential addend.  */
 680       if (ELF32_R_SYM (reloc->r_info) == 0)
 681         td->entry = _dl_tlsdesc_resolve_abs_plus_addend;
 682       /* Given a known-zero addend, we can store a pointer to the
 683          reloc in the arg position.  */
 684       else if (td->arg == 0)
 685         {
 686           td->arg = (void*)reloc;
 687           td->entry = _dl_tlsdesc_resolve_rel;
 688         }
 689       else
 690         {
 691           /* We could handle non-*ABS* relocations with non-zero addends
 692              by allocating dynamically an arg to hold a pointer to the
 693              reloc, but that sounds pointless.  */
 694           const Elf32_Rel *const r = reloc;
 695           /* The code below was borrowed from elf_dynamic_do_rel().  */
 696           const ElfW(Sym) *const symtab =
 697             (const void *) D_PTR (map, l_info[DT_SYMTAB]);
 698
 699 # ifdef RTLD_BOOTSTRAP
 700           /* The dynamic linker always uses versioning.  */
 701           assert (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL);
 702 # else
 703           if (map->l_info[VERSYMIDX (DT_VERSYM)])
 704 # endif
 705             {
 706               const ElfW(Half) *const version =
 707                 (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
 708               ElfW(Half) ndx = version[ELFW(R_SYM) (r->r_info)] & 0x7fff;
 709               elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)],
 710                                &map->l_versions[ndx],
 711                                (void *) (l_addr + r->r_offset), skip_ifunc);
 712             }
 713 # ifndef RTLD_BOOTSTRAP
 714           else
 715             elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)], NULL,
 716                              (void *) (l_addr + r->r_offset), skip_ifunc);
 717 # endif
 718         }
 719     }
 720   else if (__builtin_expect (r_type == R_386_IRELATIVE, 0))
 721     {
 722       Elf32_Addr value = map->l_addr + *reloc_addr;
 723       if (__builtin_expect (!skip_ifunc, 1))
 724         value = ((Elf32_Addr (*) (void)) value) ();
 725       *reloc_addr = value;
 726     }
 727   else
 728     _dl_reloc_bad_type (map, r_type, 1);
 729 }
 730
 731 # ifndef RTLD_BOOTSTRAP
 732
 733 auto inline void
 734 __attribute__ ((always_inline))
 735 elf_machine_lazy_rela (struct link_map *map,
 736                        Elf32_Addr l_addr, const Elf32_Rela *reloc,
 737                        int skip_ifunc)
 738 {
 739   Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
 740   const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
 741   if (__builtin_expect (r_type == R_386_JMP_SLOT, 1))
 742     ;
 743   else if (__builtin_expect (r_type == R_386_TLS_DESC, 1))
 744     {
 745       struct tlsdesc volatile * __attribute__((__unused__)) td =
 746         (struct tlsdesc volatile *)reloc_addr;
 747
 748       td->arg = (void*)reloc;
 749       td->entry = _dl_tlsdesc_resolve_rela;
 750     }
 751   else if (__builtin_expect (r_type == R_386_IRELATIVE, 0))
 752     {
 753       Elf32_Addr value = map->l_addr + reloc->r_addend;
 754       if (__builtin_expect (!skip_ifunc, 1))
 755         value = ((Elf32_Addr (*) (void)) value) ();
 756       *reloc_addr = value;
 757     }
 758   else
 759     _dl_reloc_bad_type (map, r_type, 1);
 760 }
 761
 762 # endif /* !RTLD_BOOTSTRAP */
 763
 764 #endif /* RESOLVE_MAP */