ld/emultempl/ppc32elf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright (C) 2003-2017 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, -1, 0, 0, 0, 0, 0, 0, 0 };
  42
  43 static void
  44 ppc_after_open_output (void)
  45 {
  46   if (params.emit_stub_syms < 0)
  47     params.emit_stub_syms = (link_info.emitrelocations
  48                              || bfd_link_pic (&link_info));
  49   if (params.pagesize == 0)
  50     params.pagesize = config.commonpagesize;
  51   ppc_elf_link_params (&link_info, &params);
  52 }
  53
  54 EOF
  55
  56 # No --secure-plt, --bss-plt, or --sdata-got for vxworks.
  57 if test -z "$VXWORKS_BASE_EM_FILE" ; then
  58   fragment <<EOF
  59 static void
  60 ppc_after_check_relocs (void)
  61 {
  62   if (is_ppc_elf (link_info.output_bfd))
  63     {
  64       int new_plt;
  65       int keep_new;
  66       unsigned int num_plt;
  67       unsigned int num_got;
  68       lang_output_section_statement_type *os;
  69       lang_output_section_statement_type *plt_os[2];
  70       lang_output_section_statement_type *got_os[2];
  71
  72       new_plt = ppc_elf_select_plt_layout (link_info.output_bfd, &link_info);
  73       if (new_plt < 0)
  74         einfo (_("%X%P: select_plt_layout problem %E\n"));
  75
  76       num_got = 0;
  77       num_plt = 0;
  78       for (os = &lang_output_section_statement.head->output_section_statement;
  79            os != NULL;
  80            os = os->next)
  81         {
  82           if (os->constraint == SPECIAL && strcmp (os->name, ".plt") == 0)
  83             {
  84               if (num_plt < 2)
  85                 plt_os[num_plt] = os;
  86               ++num_plt;
  87             }
  88           if (os->constraint == SPECIAL && strcmp (os->name, ".got") == 0)
  89             {
  90               if (num_got < 2)
  91                 got_os[num_got] = os;
  92               ++num_got;
  93             }
  94         }
  95
  96       keep_new = new_plt == 1 ? 0 : -1;
  97       if (num_plt == 2)
  98         {
  99           plt_os[0]->constraint = keep_new;
 100           plt_os[1]->constraint = ~keep_new;
 101         }
 102       if (num_got == 2)
 103         {
 104           if (old_got)
 105             keep_new = -1;
 106           got_os[0]->constraint = keep_new;
 107           got_os[1]->constraint = ~keep_new;
 108         }
 109     }
 110
 111   after_check_relocs_default ();
 112 }
 113
 114 EOF
 115 fi
 116 fragment <<EOF
 117 static void
 118 ppc_before_allocation (void)
 119 {
 120   if (is_ppc_elf (link_info.output_bfd))
 121     {
 122       if (ppc_elf_tls_setup (link_info.output_bfd, &link_info)
 123           && !notlsopt)
 124         {
 125           if (!ppc_elf_tls_optimize (link_info.output_bfd, &link_info))
 126             {
 127               einfo (_("%X%P: TLS problem %E\n"));
 128               return;
 129             }
 130         }
 131     }
 132
 133   gld${EMULATION_NAME}_before_allocation ();
 134
 135   ppc_elf_maybe_strip_sdata_syms (&link_info);
 136
 137   if (RELAXATION_ENABLED)
 138     params.branch_trampolines = 1;
 139
 140   /* Turn on relaxation if executable sections have addresses that
 141      might make branches overflow.  */
 142   else if (!RELAXATION_DISABLED_BY_USER)
 143     {
 144       bfd_vma low = (bfd_vma) -1;
 145       bfd_vma high = 0;
 146       asection *o;
 147
 148       /* Run lang_size_sections (if not already done).  */
 149       if (expld.phase != lang_mark_phase_enum)
 150         {
 151           expld.phase = lang_mark_phase_enum;
 152           expld.dataseg.phase = exp_dataseg_none;
 153           one_lang_size_sections_pass (NULL, FALSE);
 154           lang_reset_memory_regions ();
 155         }
 156
 157       for (o = link_info.output_bfd->sections; o != NULL; o = o->next)
 158         {
 159           if ((o->flags & (SEC_ALLOC | SEC_CODE)) != (SEC_ALLOC | SEC_CODE))
 160             continue;
 161           if (o->rawsize == 0)
 162             continue;
 163           if (low > o->vma)
 164             low = o->vma;
 165           if (high < o->vma + o->rawsize - 1)
 166             high = o->vma + o->rawsize - 1;
 167         }
 168       if (high > low && high - low > (1 << 25) - 1)
 169         params.branch_trampolines = 1;
 170     }
 171
 172   if (params.branch_trampolines
 173       || params.ppc476_workaround
 174       || params.pic_fixup > 0)
 175     ENABLE_RELAXATION;
 176 }
 177
 178 /* Replaces default zero fill padding in executable sections with
 179    "ba 0" instructions.  This works around the ppc476 icache bug if we
 180    have a function pointer tail call near the end of a page, some
 181    small amount of padding, then the function called at the beginning
 182    of the next page.  If the "ba 0" is ever executed we should hit a
 183    segv, so it's almost as good as an illegal instruction (zero).  */
 184
 185 static void
 186 no_zero_padding (lang_statement_union_type *l)
 187 {
 188   if (l->header.type == lang_padding_statement_enum
 189       && l->padding_statement.size != 0
 190       && l->padding_statement.output_section != NULL
 191       && (l->padding_statement.output_section->flags & SEC_CODE) != 0
 192       && l->padding_statement.fill->size == 0)
 193     {
 194       struct _ppc_fill_type
 195       {
 196         size_t size;
 197         unsigned char data[4];
 198       };
 199       static struct _ppc_fill_type fill_be = { 4, {0x48, 0, 0, 2} };
 200       static struct _ppc_fill_type fill_le = { 4, {2, 0, 0, 0x48} };
 201
 202       if (bfd_big_endian (link_info.output_bfd))
 203         l->padding_statement.fill = (struct _fill_type *) &fill_be;
 204       else
 205         l->padding_statement.fill = (struct _fill_type *) &fill_le;
 206     }
 207 }
 208
 209 static void
 210 ppc_finish (void)
 211 {
 212   if (params.ppc476_workaround)
 213     lang_for_each_statement (no_zero_padding);
 214   finish_default ();
 215 }
 216
 217 EOF
 218
 219 if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
 220   fragment <<EOF
 221 /* Special handling for embedded SPU executables.  */
 222 extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
 223 static bfd_boolean gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *);
 224
 225 static bfd_boolean
 226 ppc_recognized_file (lang_input_statement_type *entry)
 227 {
 228   if (embedded_spu_file (entry, "-m32"))
 229     return TRUE;
 230
 231   return gld${EMULATION_NAME}_load_symbols (entry);
 232 }
 233
 234 EOF
 235 LDEMUL_RECOGNIZED_FILE=ppc_recognized_file
 236 fi
 237
 238 # Define some shell vars to insert bits of code into the standard elf
 239 # parse_args and list_options functions.
 240 #
 241 PARSE_AND_LIST_PROLOGUE=${PARSE_AND_LIST_PROLOGUE}'
 242 #define OPTION_NO_TLS_OPT               321
 243 #define OPTION_NO_TLS_GET_ADDR_OPT      (OPTION_NO_TLS_OPT + 1)
 244 #define OPTION_NEW_PLT                  (OPTION_NO_TLS_GET_ADDR_OPT + 1)
 245 #define OPTION_OLD_PLT                  (OPTION_NEW_PLT + 1)
 246 #define OPTION_OLD_GOT                  (OPTION_OLD_PLT + 1)
 247 #define OPTION_STUBSYMS                 (OPTION_OLD_GOT + 1)
 248 #define OPTION_NO_STUBSYMS              (OPTION_STUBSYMS + 1)
 249 #define OPTION_PPC476_WORKAROUND        (OPTION_NO_STUBSYMS + 1)
 250 #define OPTION_NO_PPC476_WORKAROUND     (OPTION_PPC476_WORKAROUND + 1)
 251 #define OPTION_NO_PICFIXUP              (OPTION_NO_PPC476_WORKAROUND + 1)
 252 #define OPTION_VLE_RELOC_FIXUP          (OPTION_NO_PICFIXUP + 1)
 253 '
 254
 255 PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
 256   { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
 257   { "no-emit-stub-syms", no_argument, NULL, OPTION_NO_STUBSYMS },
 258   { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
 259   { "no-tls-get-addr-optimize", no_argument, NULL, OPTION_NO_TLS_GET_ADDR_OPT },'
 260 if test -z "$VXWORKS_BASE_EM_FILE" ; then
 261   PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
 262   { "secure-plt", no_argument, NULL, OPTION_NEW_PLT },
 263   { "bss-plt", no_argument, NULL, OPTION_OLD_PLT },
 264   { "sdata-got", no_argument, NULL, OPTION_OLD_GOT },'
 265 fi
 266 PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
 267   { "ppc476-workaround", optional_argument, NULL, OPTION_PPC476_WORKAROUND },
 268   { "no-ppc476-workaround", no_argument, NULL, OPTION_NO_PPC476_WORKAROUND },
 269   { "no-pic-fixup", no_argument, NULL, OPTION_NO_PICFIXUP },
 270   { "vle-reloc-fixup", no_argument, NULL, OPTION_VLE_RELOC_FIXUP },
 271 '
 272
 273 PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'
 274   fprintf (file, _("\
 275   --emit-stub-syms            Label linker stubs with a symbol.\n\
 276   --no-emit-stub-syms         Don'\''t label linker stubs with a symbol.\n\
 277   --no-tls-optimize           Don'\''t try to optimize TLS accesses.\n\
 278   --no-tls-get-addr-optimize  Don'\''t use a special __tls_get_addr call.\n'
 279 if test -z "$VXWORKS_BASE_EM_FILE" ; then
 280   PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'\
 281   --secure-plt                Use new-style PLT if possible.\n\
 282   --bss-plt                   Force old-style BSS PLT.\n\
 283   --sdata-got                 Force GOT location just before .sdata.\n'
 284 fi
 285 PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'\
 286   --ppc476-workaround [=pagesize]\n\
 287                               Avoid a cache bug on ppc476.\n\
 288   --no-ppc476-workaround      Disable workaround.\n\
 289   --no-pic-fixup              Don'\''t edit non-pic to pic.\n\
 290   --vle-reloc-fixup           Correct old object file 16A/16D relocation.\n"
 291                    ));
 292 '
 293
 294 PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LIST_ARGS_CASES}'
 295     case OPTION_STUBSYMS:
 296       params.emit_stub_syms = 1;
 297       break;
 298
 299     case OPTION_NO_STUBSYMS:
 300       params.emit_stub_syms = 0;
 301       break;
 302
 303     case OPTION_NO_TLS_OPT:
 304       notlsopt = 1;
 305       break;
 306
 307     case OPTION_NO_TLS_GET_ADDR_OPT:
 308       params.no_tls_get_addr_opt = 1;
 309       break;
 310
 311     case OPTION_NEW_PLT:
 312       params.plt_style = PLT_NEW;
 313       break;
 314
 315     case OPTION_OLD_PLT:
 316       params.plt_style = PLT_OLD;
 317       break;
 318
 319     case OPTION_OLD_GOT:
 320       old_got = 1;
 321       break;
 322
 323     case OPTION_TRADITIONAL_FORMAT:
 324       notlsopt = 1;
 325       params.no_tls_get_addr_opt = 1;
 326       return FALSE;
 327
 328     case OPTION_PPC476_WORKAROUND:
 329       params.ppc476_workaround = 1;
 330       if (optarg != NULL)
 331         {
 332           char *end;
 333           params.pagesize = strtoul (optarg, &end, 0);
 334           if (*end
 335               || (params.pagesize < 4096 && params.pagesize != 0)
 336               || params.pagesize != (params.pagesize & -params.pagesize))
 337             einfo (_("%P%F: invalid pagesize `%s'\''\n"), optarg);
 338         }
 339       break;
 340
 341     case OPTION_NO_PPC476_WORKAROUND:
 342       params.ppc476_workaround = 0;
 343       break;
 344
 345     case OPTION_NO_PICFIXUP:
 346       params.pic_fixup = -1;
 347       break;
 348
 349     case OPTION_VLE_RELOC_FIXUP:
 350       params.vle_reloc_fixup = 1;
 351       break;
 352 '
 353
 354 # Put these extra ppc32elf routines in ld_${EMULATION_NAME}_emulation
 355 #
 356 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_after_open_output
 357 if test -z "$VXWORKS_BASE_EM_FILE" ; then
 358   LDEMUL_AFTER_CHECK_RELOCS=ppc_after_check_relocs
 359 fi
 360 LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
 361 LDEMUL_FINISH=ppc_finish