ld/emultempl/ppc32elf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright (C) 2003-2018 Free Software Foundation, Inc.
   3 #
   4 # This file is part of the GNU Binutils.
   5 #
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program 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
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program; if not, write to the Free Software
  18 # Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  19 # MA 02110-1301, USA.
  20 #
  21
  22 # This file is sourced from elf32.em, and defines extra powerpc32-elf
  23 # specific routines.
  24 #
  25 fragment <<EOF
  26
  27 #include "elf32-ppc.h"
  28 #include "ldlex.h"
  29 #include "ldlang.h"
  30
  31 #define is_ppc_elf(bfd) \
  32   (bfd_get_flavour (bfd) == bfd_target_elf_flavour \
  33    && elf_object_id (bfd) == PPC32_ELF_DATA)
  34
  35 /* Whether to run tls optimization.  */
  36 static int notlsopt = 0;
  37
  38 /* Choose the correct place for .got.  */
  39 static int old_got = 0;
  40
  41 static struct ppc_elf_params params = { PLT_UNSET, 0, 1, -1,
  42                                         0, 0, 0, 0, 0, 0, 0 };
  43
  44 static void
  45 ppc_after_open_output (void)
  46 {
  47   if (params.emit_stub_syms < 0)
  48     params.emit_stub_syms = (link_info.emitrelocations
  49                              || bfd_link_pic (&link_info));
  50   if (params.pagesize == 0)
  51     params.pagesize = config.commonpagesize;
  52   ppc_elf_link_params (&link_info, &params);
  53 }
  54
  55 EOF
  56
  57 # No --secure-plt, --bss-plt, or --sdata-got for vxworks.
  58 if test -z "$VXWORKS_BASE_EM_FILE" ; then
  59   fragment <<EOF
  60 static void
  61 ppc_after_check_relocs (void)
  62 {
  63   if (is_ppc_elf (link_info.output_bfd))
  64     {
  65       int new_plt;
  66       int keep_new;
  67       unsigned int num_plt;
  68       unsigned int num_got;
  69       lang_output_section_statement_type *os;
  70       lang_output_section_statement_type *plt_os[2];
  71       lang_output_section_statement_type *got_os[2];
  72
  73       new_plt = ppc_elf_select_plt_layout (link_info.output_bfd, &link_info);
  74       if (new_plt < 0)
  75         einfo (_("%X%P: select_plt_layout problem %E\n"));
  76
  77       num_got = 0;
  78       num_plt = 0;
  79       for (os = &lang_output_section_statement.head->output_section_statement;
  80            os != NULL;
  81            os = os->next)
  82         {
  83           if (os->constraint == SPECIAL && strcmp (os->name, ".plt") == 0)
  84             {
  85               if (num_plt < 2)
  86                 plt_os[num_plt] = os;
  87               ++num_plt;
  88             }
  89           if (os->constraint == SPECIAL && strcmp (os->name, ".got") == 0)
  90             {
  91               if (num_got < 2)
  92                 got_os[num_got] = os;
  93               ++num_got;
  94             }
  95         }
  96
  97       keep_new = new_plt == 1 ? 0 : -1;
  98       if (num_plt == 2)
  99         {
 100           plt_os[0]->constraint = keep_new;
 101           plt_os[1]->constraint = ~keep_new;
 102         }
 103       if (num_got == 2)
 104         {
 105           if (old_got)
 106             keep_new = -1;
 107           got_os[0]->constraint = keep_new;
 108           got_os[1]->constraint = ~keep_new;
 109         }
 110     }
 111
 112   after_check_relocs_default ();
 113 }
 114
 115 EOF
 116 fi
 117 fragment <<EOF
 118 static void
 119 ppc_before_allocation (void)
 120 {
 121   if (is_ppc_elf (link_info.output_bfd))
 122     {
 123       if (ppc_elf_tls_setup (link_info.output_bfd, &link_info)
 124           && !notlsopt)
 125         {
 126           if (!ppc_elf_tls_optimize (link_info.output_bfd, &link_info))
 127             {
 128               einfo (_("%X%P: TLS problem %E\n"));
 129               return;
 130             }
 131         }
 132     }
 133
 134   gld${EMULATION_NAME}_before_allocation ();
 135
 136   ppc_elf_maybe_strip_sdata_syms (&link_info);
 137
 138   if (RELAXATION_ENABLED)
 139     params.branch_trampolines = 1;
 140
 141   /* Turn on relaxation if executable sections have addresses that
 142      might make branches overflow.  */
 143   else if (!RELAXATION_DISABLED_BY_USER)
 144     {
 145       bfd_vma low = (bfd_vma) -1;
 146       bfd_vma high = 0;
 147       asection *o;
 148
 149       /* Run lang_size_sections (if not already done).  */
 150       if (expld.phase != lang_mark_phase_enum)
 151         {
 152           expld.phase = lang_mark_phase_enum;
 153           expld.dataseg.phase = exp_seg_none;
 154           one_lang_size_sections_pass (NULL, FALSE);
 155           lang_reset_memory_regions ();
 156         }
 157
 158       for (o = link_info.output_bfd->sections; o != NULL; o = o->next)
 159         {
 160           if ((o->flags & (SEC_ALLOC | SEC_CODE)) != (SEC_ALLOC | SEC_CODE))
 161             continue;
 162           if (o->rawsize == 0)
 163             continue;
 164           if (low > o->vma)
 165             low = o->vma;
 166           if (high < o->vma + o->rawsize - 1)
 167             high = o->vma + o->rawsize - 1;
 168         }
 169       if (high > low && high - low > (1 << 25) - 1)
 170         params.branch_trampolines = 1;
 171     }
 172
 173   if (params.branch_trampolines
 174       || params.ppc476_workaround
 175       || params.pic_fixup > 0)
 176     ENABLE_RELAXATION;
 177 }
 178
 179 /* Replaces default zero fill padding in executable sections with
 180    "ba 0" instructions.  This works around the ppc476 icache bug if we
 181    have a function pointer tail call near the end of a page, some
 182    small amount of padding, then the function called at the beginning
 183    of the next page.  If the "ba 0" is ever executed we should hit a
 184    segv, so it's almost as good as an illegal instruction (zero).  */
 185
 186 static void
 187 no_zero_padding (lang_statement_union_type *l)
 188 {
 189   if (l->header.type == lang_padding_statement_enum
 190       && l->padding_statement.size != 0
 191       && l->padding_statement.output_section != NULL
 192       && (l->padding_statement.output_section->flags & SEC_CODE) != 0
 193       && l->padding_statement.fill->size == 0)
 194     {
 195       struct _ppc_fill_type
 196       {
 197         size_t size;
 198         unsigned char data[4];
 199       };
 200       static struct _ppc_fill_type fill_be = { 4, {0x48, 0, 0, 2} };
 201       static struct _ppc_fill_type fill_le = { 4, {2, 0, 0, 0x48} };
 202
 203       if (bfd_big_endian (link_info.output_bfd))
 204         l->padding_statement.fill = (struct _fill_type *) &fill_be;
 205       else
 206         l->padding_statement.fill = (struct _fill_type *) &fill_le;
 207     }
 208 }
 209
 210 static void
 211 ppc_finish (void)
 212 {
 213   if (params.ppc476_workaround)
 214     lang_for_each_statement (no_zero_padding);
 215   finish_default ();
 216 }
 217
 218 EOF
 219
 220 if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
 221   fragment <<EOF
 222 /* Special handling for embedded SPU executables.  */
 223 extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
 224 static bfd_boolean gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *);
 225
 226 static bfd_boolean
 227 ppc_recognized_file (lang_input_statement_type *entry)
 228 {
 229   if (embedded_spu_file (entry, "-m32"))
 230     return TRUE;
 231
 232   return gld${EMULATION_NAME}_load_symbols (entry);
 233 }
 234
 235 EOF
 236 LDEMUL_RECOGNIZED_FILE=ppc_recognized_file
 237 fi
 238
 239 # Define some shell vars to insert bits of code into the standard elf
 240 # parse_args and list_options functions.
 241 #
 242 PARSE_AND_LIST_PROLOGUE=${PARSE_AND_LIST_PROLOGUE}'
 243 enum ppc32_opt
 244 {
 245   OPTION_NO_TLS_OPT = 321,
 246   OPTION_NO_TLS_GET_ADDR_OPT,
 247   OPTION_NEW_PLT,
 248   OPTION_OLD_PLT,
 249   OPTION_SPECULATE_INDIRECT_JUMPS,
 250   OPTION_NO_SPECULATE_INDIRECT_JUMPS,
 251   OPTION_PLT_ALIGN,
 252   OPTION_NO_PLT_ALIGN,
 253   OPTION_OLD_GOT,
 254   OPTION_STUBSYMS,
 255   OPTION_NO_STUBSYMS,
 256   OPTION_PPC476_WORKAROUND,
 257   OPTION_NO_PPC476_WORKAROUND,
 258   OPTION_NO_PICFIXUP,
 259   OPTION_VLE_RELOC_FIXUP
 260 };
 261 '
 262
 263 PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
 264   { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
 265   { "no-emit-stub-syms", no_argument, NULL, OPTION_NO_STUBSYMS },
 266   { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
 267   { "no-tls-get-addr-optimize", no_argument, NULL, OPTION_NO_TLS_GET_ADDR_OPT },'
 268 if test -z "$VXWORKS_BASE_EM_FILE" ; then
 269   PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
 270   { "secure-plt", no_argument, NULL, OPTION_NEW_PLT },
 271   { "bss-plt", no_argument, NULL, OPTION_OLD_PLT },
 272   { "speculate-indirect-jumps", no_argument, NULL, OPTION_SPECULATE_INDIRECT_JUMPS },
 273   { "no-speculate-indirect-jumps", no_argument, NULL, OPTION_NO_SPECULATE_INDIRECT_JUMPS },
 274   { "plt-align", no_argument, NULL, OPTION_PLT_ALIGN },
 275   { "no-plt-align", no_argument, NULL, OPTION_NO_PLT_ALIGN },
 276   { "sdata-got", no_argument, NULL, OPTION_OLD_GOT },'
 277 fi
 278 PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
 279   { "ppc476-workaround", optional_argument, NULL, OPTION_PPC476_WORKAROUND },
 280   { "no-ppc476-workaround", no_argument, NULL, OPTION_NO_PPC476_WORKAROUND },
 281   { "no-pic-fixup", no_argument, NULL, OPTION_NO_PICFIXUP },
 282   { "vle-reloc-fixup", no_argument, NULL, OPTION_VLE_RELOC_FIXUP },
 283 '
 284
 285 PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'
 286   fprintf (file, _("\
 287   --emit-stub-syms            Label linker stubs with a symbol.\n"
 288                    ));
 289   fprintf (file, _("\
 290   --no-emit-stub-syms         Don'\''t label linker stubs with a symbol.\n"
 291                    ));
 292   fprintf (file, _("\
 293   --no-tls-optimize           Don'\''t try to optimize TLS accesses.\n"
 294                    ));
 295   fprintf (file, _("\
 296   --no-tls-get-addr-optimize  Don'\''t use a special __tls_get_addr call.\n"
 297                    ));'
 298 if test -z "$VXWORKS_BASE_EM_FILE" ; then
 299   PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'\
 300   fprintf (file, _("\
 301   --secure-plt                Use new-style PLT if possible.\n"
 302                    ));
 303   fprintf (file, _("\
 304   --bss-plt                   Force old-style BSS PLT.\n"
 305                    ));
 306   fprintf (file, _("\
 307   --speculate-indirect-jumps  PLT call stubs without speculation barrier.\n"
 308                    ));
 309   fprintf (file, _("\
 310   --no-speculate-indirect-jumps PLT call stubs with speculation barrier.\n"
 311                    ));
 312   fprintf (file, _("\
 313   --plt-align                 Align PLT call stubs to fit cache lines.\n"
 314                    ));
 315   fprintf (file, _("\
 316   --no-plt-align              Dont'\''t align individual PLT call stubs.\n"
 317                    ));
 318   fprintf (file, _("\
 319   --sdata-got                 Force GOT location just before .sdata.\n"
 320                    ));'
 321 fi
 322 PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'\
 323   fprintf (file, _("\
 324   --ppc476-workaround [=pagesize]\n\
 325                               Avoid a cache bug on ppc476.\n"
 326                    ));
 327   fprintf (file, _("\
 328   --no-ppc476-workaround      Disable workaround.\n"
 329                    ));
 330   fprintf (file, _("\
 331   --no-pic-fixup              Don'\''t edit non-pic to pic.\n"
 332                    ));
 333   fprintf (file, _("\
 334   --vle-reloc-fixup           Correct old object file 16A/16D relocation.\n"
 335                    ));
 336 '
 337
 338 PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LIST_ARGS_CASES}'
 339     case OPTION_STUBSYMS:
 340       params.emit_stub_syms = 1;
 341       break;
 342
 343     case OPTION_NO_STUBSYMS:
 344       params.emit_stub_syms = 0;
 345       break;
 346
 347     case OPTION_NO_TLS_OPT:
 348       notlsopt = 1;
 349       break;
 350
 351     case OPTION_NO_TLS_GET_ADDR_OPT:
 352       params.no_tls_get_addr_opt = 1;
 353       break;
 354
 355     case OPTION_NEW_PLT:
 356       params.plt_style = PLT_NEW;
 357       break;
 358
 359     case OPTION_OLD_PLT:
 360       params.plt_style = PLT_OLD;
 361       break;
 362
 363     case OPTION_SPECULATE_INDIRECT_JUMPS:
 364       params.speculate_indirect_jumps = 1;
 365       break;
 366
 367     case OPTION_NO_SPECULATE_INDIRECT_JUMPS:
 368       params.speculate_indirect_jumps = 0;
 369       break;
 370
 371     case OPTION_PLT_ALIGN:
 372       params.plt_stub_align = 5;
 373       break;
 374
 375     case OPTION_NO_PLT_ALIGN:
 376       params.plt_stub_align = 0;
 377       break;
 378
 379     case OPTION_OLD_GOT:
 380       old_got = 1;
 381       break;
 382
 383     case OPTION_TRADITIONAL_FORMAT:
 384       notlsopt = 1;
 385       params.no_tls_get_addr_opt = 1;
 386       return FALSE;
 387
 388     case OPTION_PPC476_WORKAROUND:
 389       params.ppc476_workaround = 1;
 390       if (optarg != NULL)
 391         {
 392           char *end;
 393           params.pagesize = strtoul (optarg, &end, 0);
 394           if (*end
 395               || (params.pagesize < 4096 && params.pagesize != 0)
 396               || params.pagesize != (params.pagesize & -params.pagesize))
 397             einfo (_("%P%F: invalid pagesize `%s'\''\n"), optarg);
 398         }
 399       break;
 400
 401     case OPTION_NO_PPC476_WORKAROUND:
 402       params.ppc476_workaround = 0;
 403       break;
 404
 405     case OPTION_NO_PICFIXUP:
 406       params.pic_fixup = -1;
 407       break;
 408
 409     case OPTION_VLE_RELOC_FIXUP:
 410       params.vle_reloc_fixup = 1;
 411       break;
 412 '
 413
 414 # Put these extra ppc32elf routines in ld_${EMULATION_NAME}_emulation
 415 #
 416 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_after_open_output
 417 if test -z "$VXWORKS_BASE_EM_FILE" ; then
 418   LDEMUL_AFTER_CHECK_RELOCS=ppc_after_check_relocs
 419 fi
 420 LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
 421 LDEMUL_FINISH=ppc_finish