ld/emultempl/ppc32elf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright (C) 2003-2019 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 /* Whether to convert inline PLT calls to direct.  */
  39 static int no_inline_opt = 0;
  40
  41 /* Choose the correct place for .got.  */
  42 static int old_got = 0;
  43
  44 static struct ppc_elf_params params = { PLT_UNSET, 0, -1,
  45                                         0, 0, 0, 0, 0, 0, 0 };
  46
  47 static void
  48 ppc_after_open_output (void)
  49 {
  50   if (params.emit_stub_syms < 0)
  51     params.emit_stub_syms = (link_info.emitrelocations
  52                              || bfd_link_pic (&link_info));
  53   if (params.pagesize == 0)
  54     params.pagesize = config.commonpagesize;
  55   ppc_elf_link_params (&link_info, &params);
  56 }
  57
  58 EOF
  59
  60 # No --secure-plt, --bss-plt, or --sdata-got for vxworks.
  61 if test -z "$VXWORKS_BASE_EM_FILE" ; then
  62   fragment <<EOF
  63 static void
  64 ppc_after_check_relocs (void)
  65 {
  66   if (is_ppc_elf (link_info.output_bfd))
  67     {
  68       int new_plt;
  69       int keep_new;
  70       unsigned int num_plt;
  71       unsigned int num_got;
  72       lang_output_section_statement_type *os;
  73       lang_output_section_statement_type *plt_os[2];
  74       lang_output_section_statement_type *got_os[2];
  75
  76       new_plt = ppc_elf_select_plt_layout (link_info.output_bfd, &link_info);
  77       if (new_plt < 0)
  78         einfo (_("%X%P: select_plt_layout problem %E\n"));
  79
  80       num_got = 0;
  81       num_plt = 0;
  82       for (os = &lang_os_list.head->output_section_statement;
  83            os != NULL;
  84            os = os->next)
  85         {
  86           if (os->constraint == SPECIAL && strcmp (os->name, ".plt") == 0)
  87             {
  88               if (num_plt < 2)
  89                 plt_os[num_plt] = os;
  90               ++num_plt;
  91             }
  92           if (os->constraint == SPECIAL && strcmp (os->name, ".got") == 0)
  93             {
  94               if (num_got < 2)
  95                 got_os[num_got] = os;
  96               ++num_got;
  97             }
  98         }
  99
 100       keep_new = new_plt == 1 ? 0 : -1;
 101       if (num_plt == 2)
 102         {
 103           plt_os[0]->constraint = keep_new;
 104           plt_os[1]->constraint = ~keep_new;
 105         }
 106       if (num_got == 2)
 107         {
 108           if (old_got)
 109             keep_new = -1;
 110           got_os[0]->constraint = keep_new;
 111           got_os[1]->constraint = ~keep_new;
 112         }
 113     }
 114
 115   after_check_relocs_default ();
 116 }
 117
 118 EOF
 119 fi
 120 fragment <<EOF
 121 static void
 122 prelim_size_sections (void)
 123 {
 124   if (expld.phase != lang_mark_phase_enum)
 125     {
 126       expld.phase = lang_mark_phase_enum;
 127       expld.dataseg.phase = exp_seg_none;
 128       one_lang_size_sections_pass (NULL, FALSE);
 129       /* We must not cache anything from the preliminary sizing.  */
 130       lang_reset_memory_regions ();
 131     }
 132 }
 133
 134 static void
 135 ppc_before_allocation (void)
 136 {
 137   if (is_ppc_elf (link_info.output_bfd))
 138     {
 139       if (!no_inline_opt
 140           && !bfd_link_relocatable (&link_info))
 141         {
 142           prelim_size_sections ();
 143
 144           if (!ppc_elf_inline_plt (&link_info))
 145             einfo (_("%X%P: inline PLT: %E\n"));
 146         }
 147
 148       if (ppc_elf_tls_setup (link_info.output_bfd, &link_info)
 149           && !notlsopt)
 150         {
 151           if (!ppc_elf_tls_optimize (link_info.output_bfd, &link_info))
 152             {
 153               einfo (_("%X%P: TLS problem %E\n"));
 154               return;
 155             }
 156         }
 157     }
 158
 159   gld${EMULATION_NAME}_before_allocation ();
 160
 161   ppc_elf_maybe_strip_sdata_syms (&link_info);
 162
 163   if (RELAXATION_ENABLED)
 164     params.branch_trampolines = 1;
 165
 166   /* Turn on relaxation if executable sections have addresses that
 167      might make branches overflow.  */
 168   else if (!RELAXATION_DISABLED_BY_USER)
 169     {
 170       bfd_vma low = (bfd_vma) -1;
 171       bfd_vma high = 0;
 172       asection *o;
 173
 174       /* Run lang_size_sections (if not already done).  */
 175       prelim_size_sections ();
 176
 177       for (o = link_info.output_bfd->sections; o != NULL; o = o->next)
 178         {
 179           if ((o->flags & (SEC_ALLOC | SEC_CODE)) != (SEC_ALLOC | SEC_CODE))
 180             continue;
 181           if (o->rawsize == 0)
 182             continue;
 183           if (low > o->vma)
 184             low = o->vma;
 185           if (high < o->vma + o->rawsize - 1)
 186             high = o->vma + o->rawsize - 1;
 187         }
 188       if (high > low && high - low > (1 << 25) - 1)
 189         params.branch_trampolines = 1;
 190     }
 191
 192   if (params.branch_trampolines
 193       || params.ppc476_workaround
 194       || params.pic_fixup > 0)
 195     ENABLE_RELAXATION;
 196 }
 197
 198 /* Replaces default zero fill padding in executable sections with
 199    "ba 0" instructions.  This works around the ppc476 icache bug if we
 200    have a function pointer tail call near the end of a page, some
 201    small amount of padding, then the function called at the beginning
 202    of the next page.  If the "ba 0" is ever executed we should hit a
 203    segv, so it's almost as good as an illegal instruction (zero).  */
 204
 205 static void
 206 no_zero_padding (lang_statement_union_type *l)
 207 {
 208   if (l->header.type == lang_padding_statement_enum
 209       && l->padding_statement.size != 0
 210       && l->padding_statement.output_section != NULL
 211       && (l->padding_statement.output_section->flags & SEC_CODE) != 0
 212       && l->padding_statement.fill->size == 0)
 213     {
 214       struct _ppc_fill_type
 215       {
 216         size_t size;
 217         unsigned char data[4];
 218       };
 219       static struct _ppc_fill_type fill_be = { 4, {0x48, 0, 0, 2} };
 220       static struct _ppc_fill_type fill_le = { 4, {2, 0, 0, 0x48} };
 221
 222       if (bfd_big_endian (link_info.output_bfd))
 223         l->padding_statement.fill = (struct _fill_type *) &fill_be;
 224       else
 225         l->padding_statement.fill = (struct _fill_type *) &fill_le;
 226     }
 227 }
 228
 229 static void
 230 ppc_finish (void)
 231 {
 232   if (params.ppc476_workaround)
 233     lang_for_each_statement (no_zero_padding);
 234   if (!ppc_finish_symbols (&link_info))
 235     einfo (_("%X%P: ppc_finish_symbols problem %E\n"));
 236   finish_default ();
 237 }
 238
 239 EOF
 240
 241 if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
 242   fragment <<EOF
 243 /* Special handling for embedded SPU executables.  */
 244 extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
 245 static bfd_boolean gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *);
 246
 247 static bfd_boolean
 248 ppc_recognized_file (lang_input_statement_type *entry)
 249 {
 250   if (embedded_spu_file (entry, "-m32"))
 251     return TRUE;
 252
 253   return gld${EMULATION_NAME}_load_symbols (entry);
 254 }
 255
 256 EOF
 257 LDEMUL_RECOGNIZED_FILE=ppc_recognized_file
 258 fi
 259
 260 # Define some shell vars to insert bits of code into the standard elf
 261 # parse_args and list_options functions.
 262 #
 263 PARSE_AND_LIST_PROLOGUE=${PARSE_AND_LIST_PROLOGUE}'
 264 enum ppc32_opt
 265 {
 266   OPTION_NO_TLS_OPT = 321,
 267   OPTION_NO_TLS_GET_ADDR_OPT,
 268   OPTION_NEW_PLT,
 269   OPTION_OLD_PLT,
 270   OPTION_PLT_ALIGN,
 271   OPTION_NO_PLT_ALIGN,
 272   OPTION_NO_INLINE_OPT,
 273   OPTION_OLD_GOT,
 274   OPTION_STUBSYMS,
 275   OPTION_NO_STUBSYMS,
 276   OPTION_PPC476_WORKAROUND,
 277   OPTION_NO_PPC476_WORKAROUND,
 278   OPTION_NO_PICFIXUP,
 279   OPTION_VLE_RELOC_FIXUP
 280 };
 281 '
 282
 283 PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
 284   { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
 285   { "no-emit-stub-syms", no_argument, NULL, OPTION_NO_STUBSYMS },
 286   { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
 287   { "no-tls-get-addr-optimize", no_argument, NULL, OPTION_NO_TLS_GET_ADDR_OPT },'
 288 if test -z "$VXWORKS_BASE_EM_FILE" ; then
 289   PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
 290   { "secure-plt", no_argument, NULL, OPTION_NEW_PLT },
 291   { "bss-plt", no_argument, NULL, OPTION_OLD_PLT },
 292   { "plt-align", optional_argument, NULL, OPTION_PLT_ALIGN },
 293   { "no-plt-align", no_argument, NULL, OPTION_NO_PLT_ALIGN },
 294   { "no-inline-optimize", no_argument, NULL, OPTION_NO_INLINE_OPT },
 295   { "sdata-got", no_argument, NULL, OPTION_OLD_GOT },'
 296 fi
 297 PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
 298   { "ppc476-workaround", optional_argument, NULL, OPTION_PPC476_WORKAROUND },
 299   { "no-ppc476-workaround", no_argument, NULL, OPTION_NO_PPC476_WORKAROUND },
 300   { "no-pic-fixup", no_argument, NULL, OPTION_NO_PICFIXUP },
 301   { "vle-reloc-fixup", no_argument, NULL, OPTION_VLE_RELOC_FIXUP },
 302 '
 303
 304 PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'
 305   fprintf (file, _("\
 306   --emit-stub-syms            Label linker stubs with a symbol\n"
 307                    ));
 308   fprintf (file, _("\
 309   --no-emit-stub-syms         Don'\''t label linker stubs with a symbol\n"
 310                    ));
 311   fprintf (file, _("\
 312   --no-tls-optimize           Don'\''t try to optimize TLS accesses\n"
 313                    ));
 314   fprintf (file, _("\
 315   --no-tls-get-addr-optimize  Don'\''t use a special __tls_get_addr call\n"
 316                    ));'
 317 if test -z "$VXWORKS_BASE_EM_FILE" ; then
 318   PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'\
 319   fprintf (file, _("\
 320   --secure-plt                Use new-style PLT if possible\n"
 321                    ));
 322   fprintf (file, _("\
 323   --bss-plt                   Force old-style BSS PLT\n"
 324                    ));
 325   fprintf (file, _("\
 326   --plt-align                 Align PLT call stubs to fit cache lines\n"
 327                    ));
 328   fprintf (file, _("\
 329   --no-plt-align              Dont'\''t align individual PLT call stubs\n"
 330                    ));
 331   fprintf (file, _("\
 332   --no-inline-optimize        Don'\''t convert inline PLT to direct calls\n"
 333                    ));
 334   fprintf (file, _("\
 335   --sdata-got                 Force GOT location just before .sdata\n"
 336                    ));'
 337 fi
 338 PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'\
 339   fprintf (file, _("\
 340   --ppc476-workaround [=pagesize]\n\
 341                               Avoid a cache bug on ppc476\n"
 342                    ));
 343   fprintf (file, _("\
 344   --no-ppc476-workaround      Disable workaround\n"
 345                    ));
 346   fprintf (file, _("\
 347   --no-pic-fixup              Don'\''t edit non-pic to pic\n"
 348                    ));
 349   fprintf (file, _("\
 350   --vle-reloc-fixup           Correct old object file 16A/16D relocation\n"
 351                    ));
 352 '
 353
 354 PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LIST_ARGS_CASES}'
 355     case OPTION_STUBSYMS:
 356       params.emit_stub_syms = 1;
 357       break;
 358
 359     case OPTION_NO_STUBSYMS:
 360       params.emit_stub_syms = 0;
 361       break;
 362
 363     case OPTION_NO_TLS_OPT:
 364       notlsopt = 1;
 365       break;
 366
 367     case OPTION_NO_TLS_GET_ADDR_OPT:
 368       params.no_tls_get_addr_opt = 1;
 369       break;
 370
 371     case OPTION_NEW_PLT:
 372       params.plt_style = PLT_NEW;
 373       break;
 374
 375     case OPTION_OLD_PLT:
 376       params.plt_style = PLT_OLD;
 377       break;
 378
 379     case OPTION_PLT_ALIGN:
 380       if (optarg != NULL)
 381         {
 382           char *end;
 383           unsigned long val = strtoul (optarg, &end, 0);
 384           if (*end || val > 5)
 385             einfo (_("%F%P: invalid --plt-align `%s'\''\n"), optarg);
 386           params.plt_stub_align = val;
 387         }
 388       else
 389         params.plt_stub_align = 5;
 390       break;
 391
 392     case OPTION_NO_PLT_ALIGN:
 393       params.plt_stub_align = 0;
 394       break;
 395
 396     case OPTION_NO_INLINE_OPT:
 397       no_inline_opt = 1;
 398       break;
 399
 400     case OPTION_OLD_GOT:
 401       old_got = 1;
 402       break;
 403
 404     case OPTION_TRADITIONAL_FORMAT:
 405       notlsopt = 1;
 406       params.no_tls_get_addr_opt = 1;
 407       return FALSE;
 408
 409     case OPTION_PPC476_WORKAROUND:
 410       params.ppc476_workaround = 1;
 411       if (optarg != NULL)
 412         {
 413           char *end;
 414           params.pagesize = strtoul (optarg, &end, 0);
 415           if (*end
 416               || (params.pagesize < 4096 && params.pagesize != 0)
 417               || params.pagesize != (params.pagesize & -params.pagesize))
 418             einfo (_("%F%P: invalid pagesize `%s'\''\n"), optarg);
 419         }
 420       break;
 421
 422     case OPTION_NO_PPC476_WORKAROUND:
 423       params.ppc476_workaround = 0;
 424       break;
 425
 426     case OPTION_NO_PICFIXUP:
 427       params.pic_fixup = -1;
 428       break;
 429
 430     case OPTION_VLE_RELOC_FIXUP:
 431       params.vle_reloc_fixup = 1;
 432       break;
 433 '
 434
 435 # Put these extra ppc32elf routines in ld_${EMULATION_NAME}_emulation
 436 #
 437 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_after_open_output
 438 if test -z "$VXWORKS_BASE_EM_FILE" ; then
 439   LDEMUL_AFTER_CHECK_RELOCS=ppc_after_check_relocs
 440 fi
 441 LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
 442 LDEMUL_FINISH=ppc_finish