ld/emultempl/ppc32elf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright (C) 2003-2021 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 elf.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 = link_info.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 = (void *) lang_os_list.head;
  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 even if already done, so as to pick
 175          up gld${EMULATION_NAME}_before_allocation sizing.  This
 176          matters when we have an executable bss plt which will
 177          typically be laid out near the end of the image, ie. worst
 178          case for branches at the start of .text.  */
 179       expld.phase = lang_first_phase_enum;
 180       prelim_size_sections ();
 181
 182       for (o = link_info.output_bfd->sections; o != NULL; o = o->next)
 183         {
 184           if ((o->flags & (SEC_ALLOC | SEC_CODE)) != (SEC_ALLOC | SEC_CODE))
 185             continue;
 186           if (o->rawsize == 0)
 187             continue;
 188           if (low > o->vma)
 189             low = o->vma;
 190           if (high < o->vma + o->rawsize - 1)
 191             high = o->vma + o->rawsize - 1;
 192         }
 193       if (high > low && high - low > (1 << 25) - 1)
 194         params.branch_trampolines = 1;
 195     }
 196
 197   if (params.branch_trampolines
 198       || params.ppc476_workaround
 199       || params.pic_fixup > 0)
 200     ENABLE_RELAXATION;
 201 }
 202
 203 /* Replaces default zero fill padding in executable sections with
 204    "ba 0" instructions.  This works around the ppc476 icache bug if we
 205    have a function pointer tail call near the end of a page, some
 206    small amount of padding, then the function called at the beginning
 207    of the next page.  If the "ba 0" is ever executed we should hit a
 208    segv, so it's almost as good as an illegal instruction (zero).  */
 209
 210 static void
 211 no_zero_padding (lang_statement_union_type *l)
 212 {
 213   if (l->header.type == lang_padding_statement_enum
 214       && l->padding_statement.size != 0
 215       && l->padding_statement.output_section != NULL
 216       && (l->padding_statement.output_section->flags & SEC_CODE) != 0
 217       && l->padding_statement.fill->size == 0)
 218     {
 219       struct _ppc_fill_type
 220       {
 221         size_t size;
 222         unsigned char data[4];
 223       };
 224       static struct _ppc_fill_type fill_be = { 4, {0x48, 0, 0, 2} };
 225       static struct _ppc_fill_type fill_le = { 4, {2, 0, 0, 0x48} };
 226
 227       if (bfd_big_endian (link_info.output_bfd))
 228         l->padding_statement.fill = (struct _fill_type *) &fill_be;
 229       else
 230         l->padding_statement.fill = (struct _fill_type *) &fill_le;
 231     }
 232 }
 233
 234 static void
 235 ppc_finish (void)
 236 {
 237   if (params.ppc476_workaround)
 238     lang_for_each_statement (no_zero_padding);
 239   if (!ppc_finish_symbols (&link_info))
 240     einfo (_("%X%P: ppc_finish_symbols problem %E\n"));
 241   finish_default ();
 242 }
 243
 244 EOF
 245
 246 if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
 247   fragment <<EOF
 248 /* Special handling for embedded SPU executables.  */
 249 extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
 250
 251 static bfd_boolean
 252 ppc_recognized_file (lang_input_statement_type *entry)
 253 {
 254   if (embedded_spu_file (entry, "-m32"))
 255     return TRUE;
 256
 257   return ldelf_load_symbols (entry);
 258 }
 259
 260 EOF
 261 LDEMUL_RECOGNIZED_FILE=ppc_recognized_file
 262 fi
 263
 264 # Define some shell vars to insert bits of code into the standard elf
 265 # parse_args and list_options functions.
 266 #
 267 PARSE_AND_LIST_PROLOGUE=${PARSE_AND_LIST_PROLOGUE}'
 268 enum ppc32_opt
 269 {
 270   OPTION_NO_TLS_OPT = 321,
 271   OPTION_NO_TLS_GET_ADDR_OPT,
 272   OPTION_NEW_PLT,
 273   OPTION_OLD_PLT,
 274   OPTION_PLT_ALIGN,
 275   OPTION_NO_PLT_ALIGN,
 276   OPTION_NO_INLINE_OPT,
 277   OPTION_OLD_GOT,
 278   OPTION_STUBSYMS,
 279   OPTION_NO_STUBSYMS,
 280   OPTION_PPC476_WORKAROUND,
 281   OPTION_NO_PPC476_WORKAROUND,
 282   OPTION_NO_PICFIXUP,
 283   OPTION_VLE_RELOC_FIXUP
 284 };
 285 '
 286
 287 PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
 288   { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
 289   { "no-emit-stub-syms", no_argument, NULL, OPTION_NO_STUBSYMS },
 290   { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
 291   { "no-tls-get-addr-optimize", no_argument, NULL, OPTION_NO_TLS_GET_ADDR_OPT },'
 292 if test -z "$VXWORKS_BASE_EM_FILE" ; then
 293   PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
 294   { "secure-plt", no_argument, NULL, OPTION_NEW_PLT },
 295   { "bss-plt", no_argument, NULL, OPTION_OLD_PLT },
 296   { "plt-align", optional_argument, NULL, OPTION_PLT_ALIGN },
 297   { "no-plt-align", no_argument, NULL, OPTION_NO_PLT_ALIGN },
 298   { "no-inline-optimize", no_argument, NULL, OPTION_NO_INLINE_OPT },
 299   { "sdata-got", no_argument, NULL, OPTION_OLD_GOT },'
 300 fi
 301 PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
 302   { "ppc476-workaround", optional_argument, NULL, OPTION_PPC476_WORKAROUND },
 303   { "no-ppc476-workaround", no_argument, NULL, OPTION_NO_PPC476_WORKAROUND },
 304   { "no-pic-fixup", no_argument, NULL, OPTION_NO_PICFIXUP },
 305   { "vle-reloc-fixup", no_argument, NULL, OPTION_VLE_RELOC_FIXUP },
 306 '
 307
 308 PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'
 309   fprintf (file, _("\
 310   --emit-stub-syms            Label linker stubs with a symbol\n"
 311                    ));
 312   fprintf (file, _("\
 313   --no-emit-stub-syms         Don'\''t label linker stubs with a symbol\n"
 314                    ));
 315   fprintf (file, _("\
 316   --no-tls-optimize           Don'\''t try to optimize TLS accesses\n"
 317                    ));
 318   fprintf (file, _("\
 319   --no-tls-get-addr-optimize  Don'\''t use a special __tls_get_addr call\n"
 320                    ));'
 321 if test -z "$VXWORKS_BASE_EM_FILE" ; then
 322   PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'\
 323   fprintf (file, _("\
 324   --secure-plt                Use new-style PLT if possible\n"
 325                    ));
 326   fprintf (file, _("\
 327   --bss-plt                   Force old-style BSS PLT\n"
 328                    ));
 329   fprintf (file, _("\
 330   --plt-align                 Align PLT call stubs to fit cache lines\n"
 331                    ));
 332   fprintf (file, _("\
 333   --no-plt-align              Dont'\''t align individual PLT call stubs\n"
 334                    ));
 335   fprintf (file, _("\
 336   --no-inline-optimize        Don'\''t convert inline PLT to direct calls\n"
 337                    ));
 338   fprintf (file, _("\
 339   --sdata-got                 Force GOT location just before .sdata\n"
 340                    ));'
 341 fi
 342 PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'\
 343   fprintf (file, _("\
 344   --ppc476-workaround [=pagesize]\n\
 345                               Avoid a cache bug on ppc476\n"
 346                    ));
 347   fprintf (file, _("\
 348   --no-ppc476-workaround      Disable workaround\n"
 349                    ));
 350   fprintf (file, _("\
 351   --no-pic-fixup              Don'\''t edit non-pic to pic\n"
 352                    ));
 353   fprintf (file, _("\
 354   --vle-reloc-fixup           Correct old object file 16A/16D relocation\n"
 355                    ));
 356 '
 357
 358 PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LIST_ARGS_CASES}'
 359     case OPTION_STUBSYMS:
 360       params.emit_stub_syms = 1;
 361       break;
 362
 363     case OPTION_NO_STUBSYMS:
 364       params.emit_stub_syms = 0;
 365       break;
 366
 367     case OPTION_NO_TLS_OPT:
 368       notlsopt = 1;
 369       break;
 370
 371     case OPTION_NO_TLS_GET_ADDR_OPT:
 372       params.no_tls_get_addr_opt = 1;
 373       break;
 374
 375     case OPTION_NEW_PLT:
 376       params.plt_style = PLT_NEW;
 377       break;
 378
 379     case OPTION_OLD_PLT:
 380       params.plt_style = PLT_OLD;
 381       break;
 382
 383     case OPTION_PLT_ALIGN:
 384       if (optarg != NULL)
 385         {
 386           char *end;
 387           unsigned long val = strtoul (optarg, &end, 0);
 388           if (*end || val > 5)
 389             einfo (_("%F%P: invalid --plt-align `%s'\''\n"), optarg);
 390           params.plt_stub_align = val;
 391         }
 392       else
 393         params.plt_stub_align = 5;
 394       break;
 395
 396     case OPTION_NO_PLT_ALIGN:
 397       params.plt_stub_align = 0;
 398       break;
 399
 400     case OPTION_NO_INLINE_OPT:
 401       no_inline_opt = 1;
 402       break;
 403
 404     case OPTION_OLD_GOT:
 405       old_got = 1;
 406       break;
 407
 408     case OPTION_TRADITIONAL_FORMAT:
 409       notlsopt = 1;
 410       params.no_tls_get_addr_opt = 1;
 411       return FALSE;
 412
 413     case OPTION_PPC476_WORKAROUND:
 414       params.ppc476_workaround = 1;
 415       if (optarg != NULL)
 416         {
 417           char *end;
 418           params.pagesize = strtoul (optarg, &end, 0);
 419           if (*end
 420               || (params.pagesize < 4096 && params.pagesize != 0)
 421               || params.pagesize != (params.pagesize & -params.pagesize))
 422             einfo (_("%F%P: invalid pagesize `%s'\''\n"), optarg);
 423         }
 424       break;
 425
 426     case OPTION_NO_PPC476_WORKAROUND:
 427       params.ppc476_workaround = 0;
 428       break;
 429
 430     case OPTION_NO_PICFIXUP:
 431       params.pic_fixup = -1;
 432       break;
 433
 434     case OPTION_VLE_RELOC_FIXUP:
 435       params.vle_reloc_fixup = 1;
 436       break;
 437 '
 438
 439 # Put these extra ppc32elf routines in ld_${EMULATION_NAME}_emulation
 440 #
 441 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_after_open_output
 442 if test -z "$VXWORKS_BASE_EM_FILE" ; then
 443   LDEMUL_AFTER_CHECK_RELOCS=ppc_after_check_relocs
 444 fi
 445 LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
 446 LDEMUL_FINISH=ppc_finish