bfd/elf32-moxie.c

   1 /* moxie-specific support for 32-bit ELF.
   2    Copyright (C) 2009-2023 Free Software Foundation, Inc.
   3
   4    Copied from elf32-fr30.c which is..
   5    Copyright (C) 1998-2023 Free Software Foundation, Inc.
   6
   7    This file is part of BFD, the Binary File Descriptor library.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  22    MA 02110-1301, USA.  */
  23
  24 #include "sysdep.h"
  25 #include "bfd.h"
  26 #include "libbfd.h"
  27 #include "elf-bfd.h"
  28 #include "elf/moxie.h"
  29
  30 /* Forward declarations.  */
  31
  32 static reloc_howto_type moxie_elf_howto_table [] =
  33 {
  34   /* This reloc does nothing.  */
  35   HOWTO (R_MOXIE_NONE,          /* type */
  36          0,                     /* rightshift */
  37          0,                     /* size */
  38          0,                     /* bitsize */
  39          false,                 /* pc_relative */
  40          0,                     /* bitpos */
  41          complain_overflow_dont, /* complain_on_overflow */
  42          bfd_elf_generic_reloc, /* special_function */
  43          "R_MOXIE_NONE",                /* name */
  44          false,                 /* partial_inplace */
  45          0,                     /* src_mask */
  46          0,                     /* dst_mask */
  47          false),                /* pcrel_offset */
  48
  49   /* A 32 bit absolute relocation.  */
  50   HOWTO (R_MOXIE_32,            /* type */
  51          0,                     /* rightshift */
  52          4,                     /* size */
  53          32,                    /* bitsize */
  54          false,                 /* pc_relative */
  55          0,                     /* bitpos */
  56          complain_overflow_bitfield, /* complain_on_overflow */
  57          bfd_elf_generic_reloc, /* special_function */
  58          "R_MOXIE_32",          /* name */
  59          false,                 /* partial_inplace */
  60          0x00000000,            /* src_mask */
  61          0xffffffff,            /* dst_mask */
  62          false),                /* pcrel_offset */
  63
  64   /* A 10 bit PC-relative relocation.  */
  65   HOWTO (R_MOXIE_PCREL10,       /* type.  */
  66          1,                     /* rightshift.  */
  67          2,                     /* size.  */
  68          10,                    /* bitsize.  */
  69          true,                  /* pc_relative.  */
  70          0,                     /* bitpos.  */
  71          complain_overflow_signed, /* complain_on_overflow.  */
  72          bfd_elf_generic_reloc, /* special_function.  */
  73          "R_MOXIE_PCREL10",             /* name.  */
  74          false,                 /* partial_inplace.  */
  75          0,                     /* src_mask.  */
  76          0x000003FF,            /* dst_mask.  */
  77          true),                 /* pcrel_offset.  */
  78 };
  79 \f
  80 /* Map BFD reloc types to MOXIE ELF reloc types.  */
  81
  82 struct moxie_reloc_map
  83 {
  84   bfd_reloc_code_real_type bfd_reloc_val;
  85   unsigned int moxie_reloc_val;
  86 };
  87
  88 static const struct moxie_reloc_map moxie_reloc_map [] =
  89 {
  90   { BFD_RELOC_NONE,            R_MOXIE_NONE },
  91   { BFD_RELOC_32,              R_MOXIE_32 },
  92   { BFD_RELOC_MOXIE_10_PCREL,  R_MOXIE_PCREL10 },
  93 };
  94
  95 static reloc_howto_type *
  96 moxie_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
  97                          bfd_reloc_code_real_type code)
  98 {
  99   unsigned int i;
 100
 101   for (i = sizeof (moxie_reloc_map) / sizeof (moxie_reloc_map[0]);
 102        i--;)
 103     if (moxie_reloc_map [i].bfd_reloc_val == code)
 104       return & moxie_elf_howto_table [moxie_reloc_map[i].moxie_reloc_val];
 105
 106   return NULL;
 107 }
 108
 109 static reloc_howto_type *
 110 moxie_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED, const char *r_name)
 111 {
 112   unsigned int i;
 113
 114   for (i = 0;
 115        i < sizeof (moxie_elf_howto_table) / sizeof (moxie_elf_howto_table[0]);
 116        i++)
 117     if (moxie_elf_howto_table[i].name != NULL
 118         && strcasecmp (moxie_elf_howto_table[i].name, r_name) == 0)
 119       return &moxie_elf_howto_table[i];
 120
 121   return NULL;
 122 }
 123
 124 /* Set the howto pointer for an MOXIE ELF reloc.  */
 125
 126 static bool
 127 moxie_info_to_howto_rela (bfd *abfd,
 128                           arelent *cache_ptr,
 129                           Elf_Internal_Rela *dst)
 130 {
 131   unsigned int r_type;
 132
 133   r_type = ELF32_R_TYPE (dst->r_info);
 134   if (r_type >= (unsigned int) R_MOXIE_max)
 135     {
 136       /* xgettext:c-format */
 137       _bfd_error_handler (_("%pB: unsupported relocation type %#x"),
 138                           abfd, r_type);
 139       bfd_set_error (bfd_error_bad_value);
 140       return false;
 141     }
 142   cache_ptr->howto = & moxie_elf_howto_table [r_type];
 143   return true;
 144 }
 145 \f
 146 /* Perform a single relocation.  By default we use the standard BFD
 147    routines, but a few relocs, we have to do them ourselves.  */
 148
 149 static bfd_reloc_status_type
 150 moxie_final_link_relocate (reloc_howto_type *howto,
 151                            bfd *input_bfd,
 152                            asection *input_section,
 153                            bfd_byte *contents,
 154                            Elf_Internal_Rela *rel,
 155                            bfd_vma relocation)
 156 {
 157   bfd_reloc_status_type r = bfd_reloc_ok;
 158
 159   switch (howto->type)
 160     {
 161     default:
 162       r = _bfd_final_link_relocate (howto, input_bfd, input_section,
 163                                     contents, rel->r_offset,
 164                                     relocation, rel->r_addend);
 165     }
 166
 167   return r;
 168 }
 169 \f
 170 /* Relocate an MOXIE ELF section.
 171
 172    The RELOCATE_SECTION function is called by the new ELF backend linker
 173    to handle the relocations for a section.
 174
 175    The relocs are always passed as Rela structures; if the section
 176    actually uses Rel structures, the r_addend field will always be
 177    zero.
 178
 179    This function is responsible for adjusting the section contents as
 180    necessary, and (if using Rela relocs and generating a relocatable
 181    output file) adjusting the reloc addend as necessary.
 182
 183    This function does not have to worry about setting the reloc
 184    address or the reloc symbol index.
 185
 186    LOCAL_SYMS is a pointer to the swapped in local symbols.
 187
 188    LOCAL_SECTIONS is an array giving the section in the input file
 189    corresponding to the st_shndx field of each local symbol.
 190
 191    The global hash table entry for the global symbols can be found
 192    via elf_sym_hashes (input_bfd).
 193
 194    When generating relocatable output, this function must handle
 195    STB_LOCAL/STT_SECTION symbols specially.  The output symbol is
 196    going to be the section symbol corresponding to the output
 197    section, which means that the addend must be adjusted
 198    accordingly.  */
 199
 200 static int
 201 moxie_elf_relocate_section (bfd *output_bfd,
 202                             struct bfd_link_info *info,
 203                             bfd *input_bfd,
 204                             asection *input_section,
 205                             bfd_byte *contents,
 206                             Elf_Internal_Rela *relocs,
 207                             Elf_Internal_Sym *local_syms,
 208                             asection **local_sections)
 209 {
 210   Elf_Internal_Shdr *symtab_hdr;
 211   struct elf_link_hash_entry **sym_hashes;
 212   Elf_Internal_Rela *rel;
 213   Elf_Internal_Rela *relend;
 214
 215   symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
 216   sym_hashes = elf_sym_hashes (input_bfd);
 217   relend     = relocs + input_section->reloc_count;
 218
 219   for (rel = relocs; rel < relend; rel ++)
 220     {
 221       reloc_howto_type *howto;
 222       unsigned long r_symndx;
 223       Elf_Internal_Sym *sym;
 224       asection *sec;
 225       struct elf_link_hash_entry *h;
 226       bfd_vma relocation;
 227       bfd_reloc_status_type r;
 228       const char *name;
 229       int r_type;
 230
 231       r_type = ELF32_R_TYPE (rel->r_info);
 232       r_symndx = ELF32_R_SYM (rel->r_info);
 233       howto  = moxie_elf_howto_table + r_type;
 234       h      = NULL;
 235       sym    = NULL;
 236       sec    = NULL;
 237
 238       if (r_symndx < symtab_hdr->sh_info)
 239         {
 240           sym = local_syms + r_symndx;
 241           sec = local_sections [r_symndx];
 242           relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
 243
 244           name = bfd_elf_string_from_elf_section
 245             (input_bfd, symtab_hdr->sh_link, sym->st_name);
 246           name = name == NULL ? bfd_section_name (sec) : name;
 247         }
 248       else
 249         {
 250           bool unresolved_reloc, warned, ignored;
 251
 252           RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
 253                                    r_symndx, symtab_hdr, sym_hashes,
 254                                    h, sec, relocation,
 255                                    unresolved_reloc, warned, ignored);
 256
 257           name = h->root.root.string;
 258         }
 259
 260       if (sec != NULL && discarded_section (sec))
 261         RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
 262                                          rel, 1, relend, howto, 0, contents);
 263
 264       if (bfd_link_relocatable (info))
 265         continue;
 266
 267       r = moxie_final_link_relocate (howto, input_bfd, input_section,
 268                                      contents, rel, relocation);
 269
 270       if (r != bfd_reloc_ok)
 271         {
 272           const char * msg = NULL;
 273
 274           switch (r)
 275             {
 276             case bfd_reloc_overflow:
 277               (*info->callbacks->reloc_overflow)
 278                 (info, (h ? &h->root : NULL), name, howto->name,
 279                  (bfd_vma) 0, input_bfd, input_section, rel->r_offset);
 280               break;
 281
 282             case bfd_reloc_undefined:
 283               (*info->callbacks->undefined_symbol)
 284                 (info, name, input_bfd, input_section, rel->r_offset, true);
 285               break;
 286
 287             case bfd_reloc_outofrange:
 288               msg = _("internal error: out of range error");
 289               break;
 290
 291             case bfd_reloc_notsupported:
 292               msg = _("internal error: unsupported relocation error");
 293               break;
 294
 295             case bfd_reloc_dangerous:
 296               msg = _("internal error: dangerous relocation");
 297               break;
 298
 299             default:
 300               msg = _("internal error: unknown error");
 301               break;
 302             }
 303
 304           if (msg)
 305             (*info->callbacks->warning) (info, msg, name, input_bfd,
 306                                          input_section, rel->r_offset);
 307         }
 308     }
 309
 310   return true;
 311 }
 312 \f
 313 /* Return the section that should be marked against GC for a given
 314    relocation.  */
 315
 316 static asection *
 317 moxie_elf_gc_mark_hook (asection *sec,
 318                         struct bfd_link_info *info,
 319                         Elf_Internal_Rela *rel,
 320                         struct elf_link_hash_entry *h,
 321                         Elf_Internal_Sym *sym)
 322 {
 323   return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
 324 }
 325
 326 /* Look through the relocs for a section during the first phase.
 327    Since we don't do .gots or .plts, we just need to consider the
 328    virtual table relocs for gc.  */
 329
 330 static bool
 331 moxie_elf_check_relocs (bfd *abfd,
 332                         struct bfd_link_info *info,
 333                         asection *sec,
 334                         const Elf_Internal_Rela *relocs)
 335 {
 336   Elf_Internal_Shdr *symtab_hdr;
 337   struct elf_link_hash_entry **sym_hashes;
 338   const Elf_Internal_Rela *rel;
 339   const Elf_Internal_Rela *rel_end;
 340
 341   if (bfd_link_relocatable (info))
 342     return true;
 343
 344   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
 345   sym_hashes = elf_sym_hashes (abfd);
 346
 347   rel_end = relocs + sec->reloc_count;
 348   for (rel = relocs; rel < rel_end; rel++)
 349     {
 350       struct elf_link_hash_entry *h;
 351       unsigned long r_symndx;
 352
 353       r_symndx = ELF32_R_SYM (rel->r_info);
 354       if (r_symndx < symtab_hdr->sh_info)
 355         h = NULL;
 356       else
 357         {
 358           h = sym_hashes[r_symndx - symtab_hdr->sh_info];
 359           while (h->root.type == bfd_link_hash_indirect
 360                  || h->root.type == bfd_link_hash_warning)
 361             h = (struct elf_link_hash_entry *) h->root.u.i.link;
 362         }
 363     }
 364
 365   return true;
 366 }
 367 \f
 368 #define ELF_ARCH                bfd_arch_moxie
 369 #define ELF_MACHINE_CODE        EM_MOXIE
 370 #define ELF_MACHINE_ALT1        EM_MOXIE_OLD
 371 #define ELF_MAXPAGESIZE         0x1
 372
 373 #define TARGET_BIG_SYM          moxie_elf32_be_vec
 374 #define TARGET_BIG_NAME         "elf32-bigmoxie"
 375 #define TARGET_LITTLE_SYM       moxie_elf32_le_vec
 376 #define TARGET_LITTLE_NAME      "elf32-littlemoxie"
 377
 378 #define elf_info_to_howto_rel                   NULL
 379 #define elf_info_to_howto                       moxie_info_to_howto_rela
 380 #define elf_backend_relocate_section            moxie_elf_relocate_section
 381 #define elf_backend_gc_mark_hook                moxie_elf_gc_mark_hook
 382 #define elf_backend_check_relocs                moxie_elf_check_relocs
 383
 384 #define elf_backend_can_gc_sections             1
 385 #define elf_backend_rela_normal                 1
 386
 387 #define bfd_elf32_bfd_reloc_type_lookup         moxie_reloc_type_lookup
 388 #define bfd_elf32_bfd_reloc_name_lookup         moxie_reloc_name_lookup
 389
 390 #include "elf32-target.h"