sysdeps/alpha/dl-machine.h

   1 /* Machine-dependent ELF dynamic relocation inline functions.  Alpha version.
   2    Copyright (C) 1996-2001, 2002 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Richard Henderson <rth@tamu.edu>.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 /* This was written in the absence of an ABI -- don't expect
  22    it to remain unchanged.  */
  23
  24 #ifndef dl_machine_h
  25 #define dl_machine_h 1
  26
  27 #define ELF_MACHINE_NAME "alpha"
  28
  29 #include <string.h>
  30
  31
  32 /* Mask identifying addresses reserved for the user program,
  33    where the dynamic linker should not map anything.  */
  34 #define ELF_MACHINE_USER_ADDRESS_MASK   0x120000000UL
  35
  36 /* Return nonzero iff ELF header is compatible with the running host.  */
  37 static inline int
  38 elf_machine_matches_host (const Elf64_Ehdr *ehdr)
  39 {
  40   return ehdr->e_machine == EM_ALPHA;
  41 }
  42
  43 /* Return the link-time address of _DYNAMIC.  The multiple-got-capable
  44    linker no longer allocates the first .got entry for this.  But not to
  45    worry, no special tricks are needed.  */
  46 static inline Elf64_Addr
  47 elf_machine_dynamic (void)
  48 {
  49 #ifndef NO_AXP_MULTI_GOT_LD
  50   return (Elf64_Addr) &_DYNAMIC;
  51 #else
  52   register Elf64_Addr *gp __asm__ ("$29");
  53   return gp[-4096];
  54 #endif
  55 }
  56
  57 /* Return the run-time load address of the shared object.  */
  58 static inline Elf64_Addr
  59 elf_machine_load_address (void)
  60 {
  61   /* NOTE: While it is generally unfriendly to put data in the text
  62      segment, it is only slightly less so when the "data" is an
  63      instruction.  While we don't have to worry about GLD just yet, an
  64      optimizing linker might decide that our "data" is an unreachable
  65      instruction and throw it away -- with the right switches, DEC's
  66      linker will do this.  What ought to happen is we should add
  67      something to GAS to allow us access to the new GPREL_HI32/LO32
  68      relocation types stolen from OSF/1 3.0.  */
  69   /* This code relies on the fact that BRADDR relocations do not
  70      appear in dynamic relocation tables.  Not that that would be very
  71      useful anyway -- br/bsr has a 4MB range and the shared libraries
  72      are usually many many terabytes away.  */
  73
  74   Elf64_Addr dot;
  75   long int zero_disp;
  76
  77   asm("br %0, 1f\n"
  78       "0:\n\t"
  79       "br $0, 2f\n"
  80       "1:\n\t"
  81       ".section\t.data\n"
  82       "2:\n\t"
  83       ".quad 0b\n\t"
  84       ".previous"
  85       : "=r"(dot));
  86
  87   zero_disp = *(int *) dot;
  88   zero_disp = (zero_disp << 43) >> 41;
  89
  90   return dot - *(Elf64_Addr *) (dot + 4 + zero_disp);
  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
  97 elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
  98 {
  99   Elf64_Addr plt;
 100   extern void _dl_runtime_resolve (void);
 101   extern void _dl_runtime_profile (void);
 102
 103   if (l->l_info[DT_JMPREL] && lazy)
 104     {
 105       /* The GOT entries for the functions in the PLT have not been
 106          filled in yet.  Their initial contents are directed to the
 107          PLT which arranges for the dynamic linker to be called.  */
 108       plt = D_PTR (l, l_info[DT_PLTGOT]);
 109
 110       /* This function will be called to perform the relocation.  */
 111       if (!profile)
 112         *(Elf64_Addr *)(plt + 16) = (Elf64_Addr) &_dl_runtime_resolve;
 113       else
 114         {
 115           *(Elf64_Addr *)(plt + 16) = (Elf64_Addr) &_dl_runtime_profile;
 116
 117           if (_dl_name_match_p (GL(dl_profile), l))
 118             {
 119               /* This is the object we are looking for.  Say that we really
 120                  want profiling and the timers are started.  */
 121               GL(dl_profile_map) = l;
 122             }
 123         }
 124
 125       /* Identify this shared object */
 126       *(Elf64_Addr *)(plt + 24) = (Elf64_Addr) l;
 127
 128       /* If the first instruction of the plt entry is not
 129          "br $28, plt0", we have to reinitialize .plt for lazy relocation.  */
 130       if (*(unsigned int *)(plt + 32) != 0xc39ffff7)
 131         {
 132           unsigned int val = 0xc39ffff7;
 133           unsigned int *slot, *end;
 134           const Elf64_Rela *rela = (const Elf64_Rela *)
 135                                    D_PTR (l, l_info[DT_JMPREL]);
 136           Elf64_Addr l_addr = l->l_addr;
 137
 138           /* br t12,.+4; ldq t12,12(t12); nop; jmp t12,(t12),.+4 */
 139           *(unsigned long *)plt = 0xa77b000cc3600000;
 140           *(unsigned long *)(plt + 8) = 0x6b7b000047ff041f;
 141           slot = (unsigned int *)(plt + 32);
 142           end = (unsigned int *)(plt + 32
 143                                  + l->l_info[DT_PLTRELSZ]->d_un.d_val / 2);
 144           while (slot < end)
 145             {
 146               /* br at,.plt+0 */
 147               *slot = val;
 148               *(Elf64_Addr *) rela->r_offset = (Elf64_Addr) slot - l_addr;
 149               val -= 3;
 150               slot += 3;
 151               ++rela;
 152             }
 153         }
 154     }
 155
 156   return lazy;
 157 }
 158
 159 /* This code is used in dl-runtime.c to call the `fixup' function
 160    and then redirect to the address it returns.  */
 161 #define TRAMPOLINE_TEMPLATE(tramp_name, fixup_name, IMB)        \
 162   extern void tramp_name (void);                                \
 163   asm ( "\
 164         .globl " #tramp_name "                                  \n\
 165         .ent " #tramp_name "                                    \n\
 166 " #tramp_name ":                                                \n\
 167         lda     $sp, -44*8($sp)                                 \n\
 168         .frame  $sp, 44*8, $26                                  \n\
 169         /* Preserve all integer registers that C normally       \n\
 170            doesn't.  */                                         \n\
 171         stq     $26, 0*8($sp)                                   \n\
 172         stq     $0, 1*8($sp)                                    \n\
 173         stq     $1, 2*8($sp)                                    \n\
 174         stq     $2, 3*8($sp)                                    \n\
 175         stq     $3, 4*8($sp)                                    \n\
 176         stq     $4, 5*8($sp)                                    \n\
 177         stq     $5, 6*8($sp)                                    \n\
 178         stq     $6, 7*8($sp)                                    \n\
 179         stq     $7, 8*8($sp)                                    \n\
 180         stq     $8, 9*8($sp)                                    \n\
 181         stq     $16, 10*8($sp)                                  \n\
 182         stq     $17, 11*8($sp)                                  \n\
 183         stq     $18, 12*8($sp)                                  \n\
 184         stq     $19, 13*8($sp)                                  \n\
 185         stq     $20, 14*8($sp)                                  \n\
 186         stq     $21, 15*8($sp)                                  \n\
 187         stq     $22, 16*8($sp)                                  \n\
 188         stq     $23, 17*8($sp)                                  \n\
 189         stq     $24, 18*8($sp)                                  \n\
 190         stq     $25, 19*8($sp)                                  \n\
 191         stq     $29, 20*8($sp)                                  \n\
 192         stt     $f0, 21*8($sp)                                  \n\
 193         stt     $f1, 22*8($sp)                                  \n\
 194         stt     $f10, 23*8($sp)                                 \n\
 195         stt     $f11, 24*8($sp)                                 \n\
 196         stt     $f12, 25*8($sp)                                 \n\
 197         stt     $f13, 26*8($sp)                                 \n\
 198         stt     $f14, 27*8($sp)                                 \n\
 199         stt     $f15, 28*8($sp)                                 \n\
 200         stt     $f16, 29*8($sp)                                 \n\
 201         stt     $f17, 30*8($sp)                                 \n\
 202         stt     $f18, 31*8($sp)                                 \n\
 203         stt     $f19, 32*8($sp)                                 \n\
 204         stt     $f20, 33*8($sp)                                 \n\
 205         stt     $f21, 34*8($sp)                                 \n\
 206         stt     $f22, 35*8($sp)                                 \n\
 207         stt     $f23, 36*8($sp)                                 \n\
 208         stt     $f24, 37*8($sp)                                 \n\
 209         stt     $f25, 38*8($sp)                                 \n\
 210         stt     $f26, 39*8($sp)                                 \n\
 211         stt     $f27, 40*8($sp)                                 \n\
 212         stt     $f28, 41*8($sp)                                 \n\
 213         stt     $f29, 42*8($sp)                                 \n\
 214         stt     $f30, 43*8($sp)                                 \n\
 215         .mask   0x27ff01ff, -44*8                               \n\
 216         .fmask  0xfffffc03, -(44-21)*8                          \n\
 217         /* Set up our $gp */                                    \n\
 218         br      $gp, .+4                                        \n\
 219         ldgp    $gp, 0($gp)                                     \n\
 220         .prologue 0                                             \n\
 221         /* Set up the arguments for fixup: */                   \n\
 222         /* $16 = link_map out of plt0 */                        \n\
 223         /* $17 = offset of reloc entry = ($28 - $27 - 20) /12 * 24 */\n\
 224         /* $18 = return address */                              \n\
 225         subq    $28, $27, $17                                   \n\
 226         ldq     $16, 8($27)                                     \n\
 227         subq    $17, 20, $17                                    \n\
 228         mov     $26, $18                                        \n\
 229         addq    $17, $17, $17                                   \n\
 230         /* Do the fixup */                                      \n\
 231         bsr     $26, " #fixup_name "    !samegp                 \n\
 232         /* Move the destination address into position.  */      \n\
 233         mov     $0, $27                                         \n\
 234         /* Restore program registers.  */                       \n\
 235         ldq     $26, 0*8($sp)                                   \n\
 236         ldq     $0, 1*8($sp)                                    \n\
 237         ldq     $1, 2*8($sp)                                    \n\
 238         ldq     $2, 3*8($sp)                                    \n\
 239         ldq     $3, 4*8($sp)                                    \n\
 240         ldq     $4, 5*8($sp)                                    \n\
 241         ldq     $5, 6*8($sp)                                    \n\
 242         ldq     $6, 7*8($sp)                                    \n\
 243         ldq     $7, 8*8($sp)                                    \n\
 244         ldq     $8, 9*8($sp)                                    \n\
 245         ldq     $16, 10*8($sp)                                  \n\
 246         ldq     $17, 11*8($sp)                                  \n\
 247         ldq     $18, 12*8($sp)                                  \n\
 248         ldq     $19, 13*8($sp)                                  \n\
 249         ldq     $20, 14*8($sp)                                  \n\
 250         ldq     $21, 15*8($sp)                                  \n\
 251         ldq     $22, 16*8($sp)                                  \n\
 252         ldq     $23, 17*8($sp)                                  \n\
 253         ldq     $24, 18*8($sp)                                  \n\
 254         ldq     $25, 19*8($sp)                                  \n\
 255         ldq     $29, 20*8($sp)                                  \n\
 256         ldt     $f0, 21*8($sp)                                  \n\
 257         ldt     $f1, 22*8($sp)                                  \n\
 258         ldt     $f10, 23*8($sp)                                 \n\
 259         ldt     $f11, 24*8($sp)                                 \n\
 260         ldt     $f12, 25*8($sp)                                 \n\
 261         ldt     $f13, 26*8($sp)                                 \n\
 262         ldt     $f14, 27*8($sp)                                 \n\
 263         ldt     $f15, 28*8($sp)                                 \n\
 264         ldt     $f16, 29*8($sp)                                 \n\
 265         ldt     $f17, 30*8($sp)                                 \n\
 266         ldt     $f18, 31*8($sp)                                 \n\
 267         ldt     $f19, 32*8($sp)                                 \n\
 268         ldt     $f20, 33*8($sp)                                 \n\
 269         ldt     $f21, 34*8($sp)                                 \n\
 270         ldt     $f22, 35*8($sp)                                 \n\
 271         ldt     $f23, 36*8($sp)                                 \n\
 272         ldt     $f24, 37*8($sp)                                 \n\
 273         ldt     $f25, 38*8($sp)                                 \n\
 274         ldt     $f26, 39*8($sp)                                 \n\
 275         ldt     $f27, 40*8($sp)                                 \n\
 276         ldt     $f28, 41*8($sp)                                 \n\
 277         ldt     $f29, 42*8($sp)                                 \n\
 278         ldt     $f30, 43*8($sp)                                 \n\
 279         /* Flush the Icache after having modified the .plt code.  */\n\
 280         " #IMB "                                                \n\
 281         /* Clean up and turn control to the destination */      \n\
 282         lda     $sp, 44*8($sp)                                  \n\
 283         jmp     $31, ($27)                                      \n\
 284         .end " #tramp_name)
 285
 286 #ifndef PROF
 287 #define ELF_MACHINE_RUNTIME_TRAMPOLINE                          \
 288   TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup, imb);        \
 289   TRAMPOLINE_TEMPLATE (_dl_runtime_profile, profile_fixup, /* nop */);
 290 #else
 291 #define ELF_MACHINE_RUNTIME_TRAMPOLINE                          \
 292   TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup, imb);        \
 293   strong_alias (_dl_runtime_resolve, _dl_runtime_profile);
 294 #endif
 295
 296 /* Initial entry point code for the dynamic linker.
 297    The C function `_dl_start' is the real entry point;
 298    its return value is the user program's entry point.  */
 299
 300 #define RTLD_START asm ("\
 301         .section .text                                          \n\
 302         .set at                                                 \n\
 303         .globl _start                                           \n\
 304         .ent _start                                             \n\
 305 _start:                                                         \n\
 306         br      $gp, 0f                                         \n\
 307 0:      ldgp    $gp, 0($gp)                                     \n\
 308         .prologue 0                                             \n\
 309         /* Pass pointer to argument block to _dl_start.  */     \n\
 310         mov     $sp, $16                                        \n\
 311         bsr     $26, _dl_start          !samegp                 \n\
 312         .end _start                                             \n\
 313         /* FALLTHRU */                                          \n\
 314         .globl _dl_start_user                                   \n\
 315         .ent _dl_start_user                                     \n\
 316 _dl_start_user:                                                 \n\
 317         .frame $30,0,$31,0                                      \n\
 318         .prologue 0                                             \n\
 319         /* Save the user entry point address in s0.  */         \n\
 320         mov     $0, $9                                          \n\
 321         /* Store the highest stack address.  */                 \n\
 322         stq     $30, __libc_stack_end                           \n\
 323         /* See if we were run as a command with the executable  \n\
 324            file name as an extra leading argument.  */          \n\
 325         ldl     $1, _dl_skip_args($gp)  !gprel                  \n\
 326         bne     $1, $fixup_stack                                \n\
 327 $fixup_stack_ret:                                               \n\
 328         /* The special initializer gets called with the stack   \n\
 329            just as the application's entry point will see it;   \n\
 330            it can switch stacks if it moves these contents      \n\
 331            over.  */                                            \n\
 332 " RTLD_START_SPECIAL_INIT "                                     \n\
 333         /* Call _dl_init(_dl_loaded, argc, argv, envp) to run   \n\
 334            initializers.  */                                    \n\
 335         ldah    $16, _rtld_local($gp)   !gprelhigh              \n\
 336         ldq     $16, _rtld_local($16)   !gprellow               \n\
 337         ldq     $17, 0($sp)                                     \n\
 338         lda     $18, 8($sp)                                     \n\
 339         s8addq  $17, 8, $19                                     \n\
 340         addq    $19, $18, $19                                   \n\
 341         bsr     $26, _dl_init_internal  !samegp                 \n\
 342         /* Pass our finalizer function to the user in $0. */    \n\
 343         ldah    $0, _dl_fini($gp)       !gprelhigh              \n\
 344         lda     $0, _dl_fini($0)        !gprellow               \n\
 345         /* Jump to the user's entry point.  */                  \n\
 346         mov     $9, $27                                         \n\
 347         jmp     ($9)                                            \n\
 348 $fixup_stack:                                                   \n\
 349         /* Adjust the stack pointer to skip _dl_skip_args words.\n\
 350            This involves copying everything down, since the     \n\
 351            stack pointer must always be 16-byte aligned.  */    \n\
 352         ldq     $2, 0($sp)                                      \n\
 353         ldq     $5, _dl_argv                                    \n\
 354         subq    $31, $1, $6                                     \n\
 355         subq    $2, $1, $2                                      \n\
 356         s8addq  $6, $5, $5                                      \n\
 357         mov     $sp, $4                                         \n\
 358         s8addq  $1, $sp, $3                                     \n\
 359         stq     $2, 0($sp)                                      \n\
 360         stq     $5, _dl_argv                                    \n\
 361         /* Copy down argv.  */                                  \n\
 362 0:      ldq     $5, 8($3)                                       \n\
 363         addq    $4, 8, $4                                       \n\
 364         addq    $3, 8, $3                                       \n\
 365         stq     $5, 0($4)                                       \n\
 366         bne     $5, 0b                                          \n\
 367         /* Copy down envp.  */                                  \n\
 368 1:      ldq     $5, 8($3)                                       \n\
 369         addq    $4, 8, $4                                       \n\
 370         addq    $3, 8, $3                                       \n\
 371         stq     $5, 0($4)                                       \n\
 372         bne     $5, 1b                                          \n\
 373         /* Copy down auxiliary table.  */                       \n\
 374 2:      ldq     $5, 8($3)                                       \n\
 375         ldq     $6, 16($3)                                      \n\
 376         addq    $4, 16, $4                                      \n\
 377         addq    $3, 16, $3                                      \n\
 378         stq     $5, -8($4)                                      \n\
 379         stq     $6, 0($4)                                       \n\
 380         bne     $5, 2b                                          \n\
 381         br      $fixup_stack_ret                                \n\
 382         .end _dl_start_user                                     \n\
 383         .set noat                                               \n\
 384 .previous");
 385
 386 #ifndef RTLD_START_SPECIAL_INIT
 387 #define RTLD_START_SPECIAL_INIT /* nothing */
 388 #endif
 389
 390 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so
 391    PLT entries should not be allowed to define the value.
 392    ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
 393    of the main executable's symbols, as for a COPY reloc, which we don't
 394    use.  */
 395 #define elf_machine_type_class(type)    \
 396   (((type) == R_ALPHA_JMP_SLOT) * ELF_RTYPE_CLASS_PLT)
 397
 398 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.  */
 399 #define ELF_MACHINE_JMP_SLOT     R_ALPHA_JMP_SLOT
 400
 401 /* The alpha never uses Elf64_Rel relocations.  */
 402 #define ELF_MACHINE_NO_REL 1
 403
 404 /* Fix up the instructions of a PLT entry to invoke the function
 405    rather than the dynamic linker.  */
 406 static inline Elf64_Addr
 407 elf_machine_fixup_plt (struct link_map *l, lookup_t t,
 408                        const Elf64_Rela *reloc,
 409                        Elf64_Addr *got_addr, Elf64_Addr value)
 410 {
 411   const Elf64_Rela *rela_plt;
 412   Elf64_Word *plte;
 413   long int edisp;
 414
 415   /* Store the value we are going to load.  */
 416   *got_addr = value;
 417
 418   /* Recover the PLT entry address by calculating reloc's index into the
 419      .rela.plt, and finding that entry in the .plt.  */
 420   rela_plt = (void *) D_PTR (l, l_info[DT_JMPREL]);
 421   plte = (void *) (D_PTR (l, l_info[DT_PLTGOT]) + 32);
 422   plte += 3 * (reloc - rela_plt);
 423
 424   /* Find the displacement from the plt entry to the function.  */
 425   edisp = (long int) (value - (Elf64_Addr)&plte[3]) / 4;
 426
 427   if (edisp >= -0x100000 && edisp < 0x100000)
 428     {
 429       /* If we are in range, use br to perfect branch prediction and
 430          elide the dependency on the address load.  This case happens,
 431          e.g., when a shared library call is resolved to the same library.  */
 432
 433       int hi, lo;
 434       hi = value - (Elf64_Addr)&plte[0];
 435       lo = (short int) hi;
 436       hi = (hi - lo) >> 16;
 437
 438       /* Emit "lda $27,lo($27)" */
 439       plte[1] = 0x237b0000 | (lo & 0xffff);
 440
 441       /* Emit "br $31,function" */
 442       plte[2] = 0xc3e00000 | (edisp & 0x1fffff);
 443
 444       /* Think about thread-safety -- the previous instructions must be
 445          committed to memory before the first is overwritten.  */
 446       __asm__ __volatile__("wmb" : : : "memory");
 447
 448       /* Emit "ldah $27,hi($27)" */
 449       plte[0] = 0x277b0000 | (hi & 0xffff);
 450     }
 451   else
 452     {
 453       /* Don't bother with the hint since we already know the hint is
 454          wrong.  Eliding it prevents the wrong page from getting pulled
 455          into the cache.  */
 456
 457       int hi, lo;
 458       hi = (Elf64_Addr)got_addr - (Elf64_Addr)&plte[0];
 459       lo = (short)hi;
 460       hi = (hi - lo) >> 16;
 461
 462       /* Emit "ldq $27,lo($27)" */
 463       plte[1] = 0xa77b0000 | (lo & 0xffff);
 464
 465       /* Emit "jmp $31,($27)" */
 466       plte[2] = 0x6bfb0000;
 467
 468       /* Think about thread-safety -- the previous instructions must be
 469          committed to memory before the first is overwritten.  */
 470       __asm__ __volatile__("wmb" : : : "memory");
 471
 472       /* Emit "ldah $27,hi($27)" */
 473       plte[0] = 0x277b0000 | (hi & 0xffff);
 474     }
 475
 476   /* At this point, if we've been doing runtime resolution, Icache is dirty.
 477      This will be taken care of in _dl_runtime_resolve.  If instead we are
 478      doing this as part of non-lazy startup relocation, that bit of code
 479      hasn't made it into Icache yet, so there's nothing to clean up.  */
 480
 481   return value;
 482 }
 483
 484 /* Return the final value of a plt relocation.  */
 485 static inline Elf64_Addr
 486 elf_machine_plt_value (struct link_map *map, const Elf64_Rela *reloc,
 487                        Elf64_Addr value)
 488 {
 489   return value + reloc->r_addend;
 490 }
 491
 492 #endif /* !dl_machine_h */
 493
 494 #ifdef RESOLVE
 495
 496 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
 497    MAP is the object containing the reloc.  */
 498 static inline void
 499 elf_machine_rela (struct link_map *map,
 500                   const Elf64_Rela *reloc,
 501                   const Elf64_Sym *sym,
 502                   const struct r_found_version *version,
 503                   Elf64_Addr *const reloc_addr)
 504 {
 505   unsigned long int const r_type = ELF64_R_TYPE (reloc->r_info);
 506
 507 #if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC && !defined SHARED
 508   /* This is defined in rtld.c, but nowhere in the static libc.a; make the
 509      reference weak so static programs can still link.  This declaration
 510      cannot be done when compiling rtld.c (i.e.  #ifdef RTLD_BOOTSTRAP)
 511      because rtld.c contains the common defn for _dl_rtld_map, which is
 512      incompatible with a weak decl in the same file.  */
 513   weak_extern (_dl_rtld_map);
 514 #endif
 515
 516   /* We cannot use a switch here because we cannot locate the switch
 517      jump table until we've self-relocated.  */
 518
 519 #if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC
 520   if (__builtin_expect (r_type == R_ALPHA_RELATIVE, 0))
 521     {
 522 # if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
 523       /* Already done in dynamic linker.  */
 524       if (map != &GL(dl_rtld_map))
 525 # endif
 526         {
 527           /* XXX Make some timings.  Maybe it's preferable to test for
 528              unaligned access and only do it the complex way if necessary.  */
 529           void *reloc_addr_1 = reloc_addr;
 530           Elf64_Addr reloc_addr_val;
 531
 532           /* Load value without causing unaligned trap. */
 533           memcpy (&reloc_addr_val, reloc_addr_1, 8);
 534           reloc_addr_val += map->l_addr;
 535
 536           /* Store value without causing unaligned trap. */
 537           memcpy (reloc_addr_1, &reloc_addr_val, 8);
 538         }
 539     }
 540   else
 541 #endif
 542     if (__builtin_expect (r_type == R_ALPHA_NONE, 0))
 543       return;
 544   else
 545     {
 546       Elf64_Addr sym_value;
 547
 548 #if defined USE_TLS && !defined RTLD_BOOTSTRAP
 549       struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
 550       sym_value = sym ? sym_map->l_addr + sym->st_value : 0;
 551 #else
 552       Elf64_Addr loadbase = RESOLVE (&sym, version, r_type);
 553       sym_value = sym ? loadbase + sym->st_value : 0;
 554 #endif
 555       sym_value += reloc->r_addend;
 556
 557       if (r_type == R_ALPHA_GLOB_DAT)
 558         *reloc_addr = sym_value;
 559 #ifdef RESOLVE_CONFLICT_FIND_MAP
 560       /* In .gnu.conflict section, R_ALPHA_JMP_SLOT relocations have
 561          R_ALPHA_JMP_SLOT in lower 8 bits and the remaining 24 bits
 562          are .rela.plt index.  */
 563       else if ((r_type & 0xff) == R_ALPHA_JMP_SLOT)
 564         {
 565           /* elf_machine_fixup_plt needs the map reloc_addr points into,
 566              while in _dl_resolve_conflicts map is _dl_loaded.  */
 567           RESOLVE_CONFLICT_FIND_MAP (map, reloc_addr);
 568           reloc = ((const Elf64_Rela *) D_PTR (map, l_info[DT_JMPREL]))
 569                   + (r_type >> 8);
 570           elf_machine_fixup_plt (map, 0, reloc, reloc_addr, sym_value);
 571         }
 572 #else
 573       else if (r_type == R_ALPHA_JMP_SLOT)
 574         elf_machine_fixup_plt (map, 0, reloc, reloc_addr, sym_value);
 575 #endif
 576 #ifndef RTLD_BOOTSTRAP
 577       else if (r_type == R_ALPHA_REFQUAD)
 578         {
 579           void *reloc_addr_1 = reloc_addr;
 580
 581           /* Store value without causing unaligned trap.  */
 582           memcpy (reloc_addr_1, &sym_value, 8);
 583         }
 584 #endif
 585 #if defined USE_TLS && (!defined RTLD_BOOTSTRAP || USE___THREAD)
 586       else if (r_type == R_ALPHA_DTPMOD64)
 587         {
 588 #ifdef RTLD_BOOTSTRAP
 589           /* During startup the dynamic linker is always index 1.  */
 590           *reloc_addr = 1;
 591 #else
 592           /* Get the information from the link map returned by the
 593              resolv function.  */
 594           if (sym_map != NULL)
 595             *reloc_addr = sym_map->l_tls_modid;
 596 #endif
 597         }
 598       else if (r_type == R_ALPHA_DTPREL64)
 599         {
 600 #ifndef RTLD_BOOTSTRAP
 601           /* During relocation all TLS symbols are defined and used.
 602              Therefore the offset is already correct.  */
 603           *reloc_addr = sym_value;
 604 #endif
 605         }
 606       else if (r_type == R_ALPHA_TPREL64)
 607         {
 608 #ifdef RTLD_BOOTSTRAP
 609           *reloc_addr = sym_value - map->l_tls_offset;
 610 #else
 611           if (sym_map)
 612             {
 613               *reloc_addr = sym_value - sym_map->l_tls_offset;
 614               CHECK_STATIC_TLS (map, sym_map);
 615             }
 616 #endif
 617         }
 618 #endif /* USE_TLS */
 619       else
 620         _dl_reloc_bad_type (map, r_type, 0);
 621     }
 622 }
 623
 624 /* Let do-rel.h know that on Alpha if l_addr is 0, all RELATIVE relocs
 625    can be skipped.  */
 626 #define ELF_MACHINE_REL_RELATIVE 1
 627
 628 static inline void
 629 elf_machine_rela_relative (Elf64_Addr l_addr, const Elf64_Rela *reloc,
 630                            Elf64_Addr *const reloc_addr)
 631 {
 632   /* XXX Make some timings.  Maybe it's preverable to test for
 633      unaligned access and only do it the complex way if necessary.  */
 634   void *reloc_addr_1 = reloc_addr;
 635   Elf64_Addr reloc_addr_val;
 636
 637   /* Load value without causing unaligned trap. */
 638   memcpy (&reloc_addr_val, reloc_addr_1, 8);
 639   reloc_addr_val += l_addr;
 640
 641   /* Store value without causing unaligned trap. */
 642   memcpy (reloc_addr_1, &reloc_addr_val, 8);
 643 }
 644
 645 static inline void
 646 elf_machine_lazy_rel (struct link_map *map,
 647                       Elf64_Addr l_addr, const Elf64_Rela *reloc)
 648 {
 649   Elf64_Addr * const reloc_addr = (void *)(l_addr + reloc->r_offset);
 650   unsigned long int const r_type = ELF64_R_TYPE (reloc->r_info);
 651
 652   if (r_type == R_ALPHA_JMP_SLOT)
 653     {
 654       /* Perform a RELATIVE reloc on the .got entry that transfers
 655          to the .plt.  */
 656       *reloc_addr += l_addr;
 657     }
 658   else if (r_type == R_ALPHA_NONE)
 659     return;
 660   else
 661     _dl_reloc_bad_type (map, r_type, 1);
 662 }
 663
 664 #endif /* RESOLVE */