bfd/elf32-d10v.c

/* D10V-specific support for 32-bit ELF
   Copyright (C) 1996-2023 Free Software Foundation, Inc.
   Contributed by Martin Hunt (hunt@cygnus.com).

   This file is part of BFD, the Binary File Descriptor library.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
   MA 02110-1301, USA.  */

#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "elf/d10v.h"

/* Use REL instead of RELA to save space.  */
#define USE_REL	1

static reloc_howto_type elf_d10v_howto_table[] =
{
  /* This reloc does nothing.  */
  HOWTO (R_D10V_NONE,		/* Type.  */
	 0,			/* Rightshift.  */
	 0,			/* Size.  */
	 0,			/* Bitsize.  */
	 false,			/* PC_relative.  */
	 0,			/* Bitpos.  */
	 complain_overflow_dont,/* Complain_on_overflow.  */
	 bfd_elf_generic_reloc, /* Special_function.  */
	 "R_D10V_NONE",		/* Name.  */
	 false,			/* Partial_inplace.  */
	 0,			/* Src_mask.  */
	 0,			/* Dst_mask.  */
	 false),		/* PCrel_offset.  */

  /* An PC Relative 10-bit relocation, shifted by 2, right container.  */
  HOWTO (R_D10V_10_PCREL_R,	/* Type.  */
	 2,			/* Rightshift.  */
	 4,			/* Size.  */
	 8,			/* Bitsize.  */
	 true,			/* PC_relative.  */
	 0,			/* Bitpos.  */
	 complain_overflow_signed, /* Complain_on_overflow.  */
	 bfd_elf_generic_reloc, /* Special_function.  */
	 "R_D10V_10_PCREL_R",	/* Name.  */
	 false,			/* Partial_inplace.  */
	 0xff,			/* Src_mask.  */
	 0xff,			/* Dst_mask.  */
	 true),			/* PCrel_offset.  */

  /* An PC Relative 10-bit relocation, shifted by 2, left container.  */
  HOWTO (R_D10V_10_PCREL_L,	/* Type.  */
	 2,			/* Rightshift.  */
	 4,			/* Size.  */
	 8,			/* Bitsize.  */
	 true,			/* PC_relative.  */
	 15,			/* Bitpos.  */
	 complain_overflow_signed, /* Complain_on_overflow.  */
	 bfd_elf_generic_reloc, /* Special_function.  */
	 "R_D10V_10_PCREL_L",	/* Name.  */
	 false,			/* Partial_inplace.  */
	 0x07f8000,		/* Src_mask.  */
	 0x07f8000,		/* Dst_mask.  */
	 true),			/* PCrel_offset.  */

  /* A 16 bit absolute relocation.  */
  HOWTO (R_D10V_16,		/* Type.  */
	 0,			/* Rightshift.  */
	 2,			/* Size.  */
	 16,			/* Bitsize.  */
	 false,			/* PC_relative.  */
	 0,			/* Bitpos.  */
	 complain_overflow_dont,/* Complain_on_overflow.  */
	 bfd_elf_generic_reloc, /* Special_function.  */
	 "R_D10V_16",		/* Name.  */
	 false,			/* Partial_inplace.  */
	 0xffff,		/* Src_mask.  */
	 0xffff,		/* Dst_mask.  */
	 false),		/* PCrel_offset.  */

  /* An 18 bit absolute relocation, right shifted 2.  */
  HOWTO (R_D10V_18,		/* Type.  */
	 2,			/* Rightshift.  */
	 2,			/* Size.  */
	 16,			/* Bitsize.  */
	 false,			/* PC_relative.  */
	 0,			/* Bitpos.  */
	 complain_overflow_dont, /* Complain_on_overflow.  */
	 bfd_elf_generic_reloc, /* Special_function.  */
	 "R_D10V_18",		/* Name.  */
	 false,			/* Partial_inplace.  */
	 0xffff,		/* Src_mask.  */
	 0xffff,		/* Dst_mask.  */
	 false),		/* PCrel_offset.  */

  /* A relative 18 bit relocation, right shifted by 2.  */
  HOWTO (R_D10V_18_PCREL,	/* Type.  */
	 2,			/* Rightshift.  */
	 4,			/* Size.  */
	 16,			/* Bitsize.  */
	 true,			/* PC_relative.  */
	 0,			/* Bitpos.  */
	 complain_overflow_signed, /* Complain_on_overflow.  */
	 bfd_elf_generic_reloc, /* Special_function.  */
	 "R_D10V_18_PCREL",	/* Name.  */
	 false,			/* Partial_inplace.  */
	 0xffff,		/* Src_mask.  */
	 0xffff,		/* Dst_mask.  */
	 true),			/* PCrel_offset.  */

  /* A 32 bit absolute relocation.  */
  HOWTO (R_D10V_32,		/* Type.  */
	 0,			/* Rightshift.  */
	 4,			/* Size.  */
	 32,			/* Bitsize.  */
	 false,			/* PC_relative.  */
	 0,			/* Bitpos.  */
	 complain_overflow_dont,/* Complain_on_overflow.  */
	 bfd_elf_generic_reloc, /* Special_function.  */
	 "R_D10V_32",		/* Name.  */
	 false,			/* Partial_inplace.  */
	 0xffffffff,		/* Src_mask.  */
	 0xffffffff,		/* Dst_mask.  */
	 false),		/* PCrel_offset.  */

  /* GNU extension to record C++ vtable hierarchy.  */
  HOWTO (R_D10V_GNU_VTINHERIT,	/* Type.  */
	 0,			/* Rightshift.  */
	 4,			/* Size.  */
	 0,			/* Bitsize.  */
	 false,			/* PC_relative.  */
	 0,			/* Bitpos.  */
	 complain_overflow_dont,/* Complain_on_overflow.  */
	 NULL,			/* Special_function.  */
	 "R_D10V_GNU_VTINHERIT",/* Name.  */
	 false,			/* Partial_inplace.  */
	 0,			/* Src_mask.  */
	 0,			/* Dst_mask.  */
	 false),		/* PCrel_offset.  */

  /* GNU extension to record C++ vtable member usage.  */
  HOWTO (R_D10V_GNU_VTENTRY,	/* Type.  */
	 0,			/* Rightshift.  */
	 4,			/* Size.  */
	 0,			/* Bitsize.  */
	 false,			/* PC_relative.  */
	 0,			/* Bitpos.  */
	 complain_overflow_dont,/* Complain_on_overflow.  */
	 _bfd_elf_rel_vtable_reloc_fn,  /* Special_function.  */
	 "R_D10V_GNU_VTENTRY",	/* Name.  */
	 false,			/* Partial_inplace.  */
	 0,			/* Src_mask.  */
	 0,			/* Dst_mask.  */
	 false),		/* PCrel_offset.  */
};

/* Map BFD reloc types to D10V ELF reloc types.  */

struct d10v_reloc_map
{
  bfd_reloc_code_real_type bfd_reloc_val;
  unsigned char elf_reloc_val;
};

static const struct d10v_reloc_map d10v_reloc_map[] =
{
  { BFD_RELOC_NONE, R_D10V_NONE, },
  { BFD_RELOC_D10V_10_PCREL_R, R_D10V_10_PCREL_R },
  { BFD_RELOC_D10V_10_PCREL_L, R_D10V_10_PCREL_L },
  { BFD_RELOC_16, R_D10V_16 },
  { BFD_RELOC_D10V_18, R_D10V_18 },
  { BFD_RELOC_D10V_18_PCREL, R_D10V_18_PCREL },
  { BFD_RELOC_32, R_D10V_32 },
  { BFD_RELOC_VTABLE_INHERIT, R_D10V_GNU_VTINHERIT },
  { BFD_RELOC_VTABLE_ENTRY, R_D10V_GNU_VTENTRY },
};

static reloc_howto_type *
bfd_elf32_bfd_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
				 bfd_reloc_code_real_type code)
{
  unsigned int i;

  for (i = 0;
       i < sizeof (d10v_reloc_map) / sizeof (struct d10v_reloc_map);
       i++)
    if (d10v_reloc_map[i].bfd_reloc_val == code)
      return &elf_d10v_howto_table[d10v_reloc_map[i].elf_reloc_val];

  return NULL;
}

static reloc_howto_type *
bfd_elf32_bfd_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
				 const char *r_name)
{
  unsigned int i;

  for (i = 0;
       i < sizeof (elf_d10v_howto_table) / sizeof (elf_d10v_howto_table[0]);
       i++)
    if (elf_d10v_howto_table[i].name != NULL
	&& strcasecmp (elf_d10v_howto_table[i].name, r_name) == 0)
      return &elf_d10v_howto_table[i];

  return NULL;
}

/* Set the howto pointer for an D10V ELF reloc.  */

static bool
d10v_info_to_howto_rel (bfd *abfd,
			arelent *cache_ptr,
			Elf_Internal_Rela *dst)
{
  unsigned int r_type;

  r_type = ELF32_R_TYPE (dst->r_info);
  if (r_type >= (unsigned int) R_D10V_max)
    {
      /* xgettext:c-format */
      _bfd_error_handler (_("%pB: unsupported relocation type %#x"),
			  abfd, r_type);
      bfd_set_error (bfd_error_bad_value);
      return false;
    }
  cache_ptr->howto = &elf_d10v_howto_table[r_type];
  return true;
}

static asection *
elf32_d10v_gc_mark_hook (asection *sec,
			 struct bfd_link_info *info,
			 Elf_Internal_Rela *rel,
			 struct elf_link_hash_entry *h,
			 Elf_Internal_Sym *sym)
{
  if (h != NULL)
    switch (ELF32_R_TYPE (rel->r_info))
      {
      case R_D10V_GNU_VTINHERIT:
      case R_D10V_GNU_VTENTRY:
	return NULL;
      }

  return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
}

/* Look through the relocs for a section during the first phase.
   Since we don't do .gots or .plts, we just need to consider the
   virtual table relocs for gc.  */

static bool
elf32_d10v_check_relocs (bfd *abfd,
			 struct bfd_link_info *info,
			 asection *sec,
			 const Elf_Internal_Rela *relocs)
{
  Elf_Internal_Shdr *symtab_hdr;
  struct elf_link_hash_entry **sym_hashes;
  const Elf_Internal_Rela *rel;
  const Elf_Internal_Rela *rel_end;

  if (bfd_link_relocatable (info))
    return true;

  symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
  sym_hashes = elf_sym_hashes (abfd);

  rel_end = relocs + sec->reloc_count;
  for (rel = relocs; rel < rel_end; rel++)
    {
      struct elf_link_hash_entry *h;
      unsigned long r_symndx;

      r_symndx = ELF32_R_SYM (rel->r_info);
      if (r_symndx < symtab_hdr->sh_info)
	h = NULL;
      else
	{
	  h = sym_hashes[r_symndx - symtab_hdr->sh_info];
	  while (h->root.type == bfd_link_hash_indirect
		 || h->root.type == bfd_link_hash_warning)
	    h = (struct elf_link_hash_entry *) h->root.u.i.link;
	}

      switch (ELF32_R_TYPE (rel->r_info))
	{
	/* This relocation describes the C++ object vtable hierarchy.
	   Reconstruct it for later use during GC.  */
	case R_D10V_GNU_VTINHERIT:
	  if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
	    return false;
	  break;

	/* This relocation describes which C++ vtable entries are actually
	   used.  Record for later use during GC.  */
	case R_D10V_GNU_VTENTRY:
	  if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_offset))
	    return false;
	  break;
	}
    }

  return true;
}

static bfd_vma
extract_rel_addend (bfd *abfd,
		    bfd_byte *where,
		    reloc_howto_type *howto)
{
  bfd_vma insn, val;

  switch (bfd_get_reloc_size (howto))
    {
    case 1:
      insn = bfd_get_8 (abfd, where);
      break;
    case 2:
      insn = bfd_get_16 (abfd, where);
      break;
    case 4:
      insn = bfd_get_32 (abfd, where);
      break;
    default:
      abort ();
    }

  val = (insn & howto->dst_mask) >> howto->bitpos << howto->rightshift;
  /* We should really be testing for signed addends here, but we don't
     have that info directly in the howto.  */
  if (howto->pc_relative)
    {
      bfd_vma sign;
      sign = howto->dst_mask & (~howto->dst_mask >> 1 | ~(-(bfd_vma) 1 >> 1));
      sign = sign >> howto->bitpos << howto->rightshift;
      val = (val ^ sign) - sign;
    }
  return val;
}

static void
insert_rel_addend (bfd *abfd,
		   bfd_byte *where,
		   reloc_howto_type *howto,
		   bfd_vma addend)
{
  bfd_vma insn;

  addend = (addend >> howto->rightshift << howto->bitpos) & howto->dst_mask;
  insn = ~howto->dst_mask;
  switch (bfd_get_reloc_size (howto))
    {
    case 1:
      insn &= bfd_get_8 (abfd, where);
      insn |= addend;
      bfd_put_8 (abfd, insn, where);
      break;
    case 2:
      insn &= bfd_get_16 (abfd, where);
      insn |= addend;
      bfd_put_16 (abfd, insn, where);
      break;
    case 4:
      insn &= bfd_get_32 (abfd, where);
      insn |= addend;
      bfd_put_32 (abfd, insn, where);
      break;
    default:
      abort ();
    }
}

/* Relocate a D10V ELF section.  */

static int
elf32_d10v_relocate_section (bfd *output_bfd,
			     struct bfd_link_info *info,
			     bfd *input_bfd,
			     asection *input_section,
			     bfd_byte *contents,
			     Elf_Internal_Rela *relocs,
			     Elf_Internal_Sym *local_syms,
			     asection **local_sections)
{
  Elf_Internal_Shdr *symtab_hdr;
  struct elf_link_hash_entry **sym_hashes;
  Elf_Internal_Rela *rel, *relend;
  const char *name;

  symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
  sym_hashes = elf_sym_hashes (input_bfd);

  rel = relocs;
  relend = relocs + input_section->reloc_count;
  for (; rel < relend; rel++)
    {
      int r_type;
      reloc_howto_type *howto;
      unsigned long r_symndx;
      Elf_Internal_Sym *sym;
      asection *sec;
      struct elf_link_hash_entry *h;
      bfd_vma relocation;
      bfd_reloc_status_type r;

      r_symndx = ELF32_R_SYM (rel->r_info);
      r_type = ELF32_R_TYPE (rel->r_info);

      if (r_type == R_D10V_GNU_VTENTRY
	  || r_type == R_D10V_GNU_VTINHERIT)
	continue;

      howto = elf_d10v_howto_table + r_type;
      h = NULL;
      sym = NULL;
      sec = NULL;
      if (r_symndx < symtab_hdr->sh_info)
	{
	  sym = local_syms + r_symndx;
	  sec = local_sections[r_symndx];
	  relocation = (sec->output_section->vma
			+ sec->output_offset
			+ sym->st_value);
	  if (ELF_ST_TYPE (sym->st_info) == STT_SECTION
	      && ((sec->flags & SEC_MERGE) != 0
		  || (bfd_link_relocatable (info)
		      && sec->output_offset != 0)))
	    {
	      bfd_vma addend;
	      bfd_byte *where = contents + rel->r_offset;

	      addend = extract_rel_addend (input_bfd, where, howto);

	      if (bfd_link_relocatable (info))
		addend += sec->output_offset;
	      else
		{
		  asection *msec = sec;
		  addend = _bfd_elf_rel_local_sym (output_bfd, sym, &msec,
						   addend);
		  addend -= relocation;
		  addend += msec->output_section->vma + msec->output_offset;
		}
	      insert_rel_addend (input_bfd, where, howto, addend);
	    }
	}
      else
	{
	  bool unresolved_reloc, warned, ignored;

	  RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
				   r_symndx, symtab_hdr, sym_hashes,
				   h, sec, relocation,
				   unresolved_reloc, warned, ignored);
	}

      if (sec != NULL && discarded_section (sec))
	RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
					 rel, 1, relend, howto, 0, contents);

      if (bfd_link_relocatable (info))
	continue;

      if (h != NULL)
	name = h->root.root.string;
      else
	{
	  name = (bfd_elf_string_from_elf_section
		  (input_bfd, symtab_hdr->sh_link, sym->st_name));
	  if (name == NULL || *name == '\0')
	    name = bfd_section_name (sec);
	}

      r = _bfd_final_link_relocate (howto, input_bfd, input_section,
				    contents, rel->r_offset,
				    relocation, (bfd_vma) 0);

      if (r != bfd_reloc_ok)
	{
	  const char * msg = (const char *) 0;

	  switch (r)
	    {
	    case bfd_reloc_overflow:
	      (*info->callbacks->reloc_overflow)
		(info, (h ? &h->root : NULL), name, howto->name,
		 (bfd_vma) 0, input_bfd, input_section, rel->r_offset);
	      break;

	    case bfd_reloc_undefined:
	      (*info->callbacks->undefined_symbol)
		(info, name, input_bfd, input_section, rel->r_offset, true);
	      break;

	    case bfd_reloc_outofrange:
	      msg = _("internal error: out of range error");
	      goto common_error;

	    case bfd_reloc_notsupported:
	      msg = _("internal error: unsupported relocation error");
	      goto common_error;

	    case bfd_reloc_dangerous:
	      msg = _("internal error: dangerous error");
	      goto common_error;

	    default:
	      msg = _("internal error: unknown error");
	      /* fall through */

	    common_error:
	      (*info->callbacks->warning) (info, msg, name, input_bfd,
					   input_section, rel->r_offset);
	      break;
	    }
	}
    }

  return true;
}
#define ELF_ARCH		bfd_arch_d10v
#define ELF_MACHINE_CODE	EM_D10V
#define ELF_MACHINE_ALT1	EM_CYGNUS_D10V
#define ELF_MAXPAGESIZE		0x1000

#define TARGET_BIG_SYM		d10v_elf32_vec
#define TARGET_BIG_NAME		"elf32-d10v"

#define elf_info_to_howto		     NULL
#define elf_info_to_howto_rel		     d10v_info_to_howto_rel
#define elf_backend_object_p		     0
#define elf_backend_gc_mark_hook	     elf32_d10v_gc_mark_hook
#define elf_backend_check_relocs	     elf32_d10v_check_relocs
#define elf_backend_relocate_section	     elf32_d10v_relocate_section
#define elf_backend_can_gc_sections	     1

#include "elf32-target.h"