bfd/elfxx-kvx.c

   1 /* KVX-specific support for ELF.
   2    Copyright (C) 2009-2023 Free Software Foundation, Inc.
   3    Contributed by Kalray SA.
   4
   5    This file is part of BFD, the Binary File Descriptor library.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; see the file COPYING3. If not,
  19    see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "sysdep.h"
  22 #include "elfxx-kvx.h"
  23 #include <stdarg.h>
  24 #include <string.h>
  25
  26 /* Return non-zero if the indicated VALUE has overflowed the maximum
  27    range expressible by a unsigned number with the indicated number of
  28    BITS.  */
  29
  30 static bfd_reloc_status_type
  31 kvx_unsigned_overflow (bfd_vma value, unsigned int bits)
  32 {
  33   bfd_vma lim;
  34   if (bits >= sizeof (bfd_vma) * 8)
  35     return bfd_reloc_ok;
  36   lim = (bfd_vma) 1 << bits;
  37   if (value >= lim)
  38     return bfd_reloc_overflow;
  39   return bfd_reloc_ok;
  40 }
  41
  42 /* Return non-zero if the indicated VALUE has overflowed the maximum
  43    range expressible by an signed number with the indicated number of
  44    BITS.  */
  45
  46 static bfd_reloc_status_type
  47 kvx_signed_overflow (bfd_vma value, unsigned int bits)
  48 {
  49   bfd_vma lim;
  50
  51   if (bits >= sizeof (bfd_vma) * 8)
  52     return bfd_reloc_ok;
  53   lim = (bfd_vma) 1 << (bits - 1);
  54   if (value + lim >= lim * 2)
  55     return bfd_reloc_overflow;
  56   return bfd_reloc_ok;
  57 }
  58
  59 /* Insert the addend/value into the instruction or data object being
  60    relocated.  */
  61 bfd_reloc_status_type
  62 _bfd_kvx_elf_put_addend (bfd *abfd,
  63                          bfd_byte *address,
  64                          bfd_reloc_code_real_type r_type ATTRIBUTE_UNUSED,
  65                          reloc_howto_type *howto,
  66                          bfd_signed_vma addend)
  67 {
  68   bfd_reloc_status_type status = bfd_reloc_ok;
  69   bfd_vma contents;
  70   int size;
  71
  72   size = bfd_get_reloc_size (howto);
  73   switch (size)
  74     {
  75     case 2:
  76       contents = bfd_get_16 (abfd, address);
  77       break;
  78     case 4:
  79       if (howto->src_mask != 0xffffffff)
  80         /* Must be 32-bit instruction, always little-endian.  */
  81         contents = bfd_getl32 (address);
  82       else
  83         /* Must be 32-bit data (endianness dependent).  */
  84         contents = bfd_get_32 (abfd, address);
  85       break;
  86     case 8:
  87       contents = bfd_get_64 (abfd, address);
  88       break;
  89     default:
  90       abort ();
  91     }
  92
  93   switch (howto->complain_on_overflow)
  94     {
  95     case complain_overflow_dont:
  96       break;
  97     case complain_overflow_signed:
  98       status = kvx_signed_overflow (addend,
  99                                     howto->bitsize + howto->rightshift);
 100       break;
 101     case complain_overflow_unsigned:
 102       status = kvx_unsigned_overflow (addend,
 103                                       howto->bitsize + howto->rightshift);
 104       break;
 105     case complain_overflow_bitfield:
 106     default:
 107       abort ();
 108     }
 109
 110   addend >>= howto->rightshift;
 111
 112   /* FIXME KVX : AARCH64 is "redoing" what the link_relocate bfd
 113    * function does ie. extract bitfields and apply then to the
 114    * existing content (insn) (howto's job) Not sure exactly
 115    * why. Maybe because we need this even when not applying reloc
 116    * against a input_bfd (eg. when doing PLT).  On KVX, we have not
 117    * reached a point where we would need to write similar
 118    * functions for each insn. So we'll simply enrich the default
 119    * case for handling a bit more than "right aligned bitfields"
 120    *
 121    * Beware that this won't be able to apply generic howto !
 122    */
 123
 124   /* if (howto->dst_mask & (howto->dst_mask + 1)) */
 125   /*    return bfd_reloc_notsupported; */
 126   addend <<= howto->bitpos;
 127   contents = ((contents & ~howto->dst_mask) | (addend & howto->dst_mask));
 128
 129   switch (size)
 130     {
 131     case 2:
 132       bfd_put_16 (abfd, contents, address);
 133       break;
 134     case 4:
 135       if (howto->dst_mask != 0xffffffff)
 136         /* must be 32-bit instruction, always little-endian */
 137         bfd_putl32 (contents, address);
 138       else
 139         /* must be 32-bit data (endianness dependent) */
 140         bfd_put_32 (abfd, contents, address);
 141       break;
 142     case 8:
 143       bfd_put_64 (abfd, contents, address);
 144       break;
 145     default:
 146       abort ();
 147     }
 148
 149   return status;
 150 }
 151
 152 bool
 153 _bfd_kvx_elf_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
 154 {
 155   int offset;
 156   size_t size;
 157
 158   switch (note->descsz)
 159     {
 160     case 680: /* sizeof(struct elf_prstatus) on Linux/kvx.  */
 161       /* pr_cursig */
 162       elf_tdata (abfd)->core->signal = bfd_get_16 (abfd, note->descdata + 12);
 163
 164       /* pr_pid */
 165       elf_tdata (abfd)->core->lwpid = bfd_get_32 (abfd, note->descdata + 32);
 166
 167       /* pr_reg */
 168       offset = 112;
 169       size = 560;
 170       break;
 171
 172     default:
 173       return false;
 174     }
 175
 176   /* Make a ".reg/999" section.  */
 177   return _bfd_elfcore_make_pseudosection (abfd, ".reg", size,
 178                                           note->descpos + offset);
 179 }
 180
 181 bool
 182 _bfd_kvx_elf_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
 183 {
 184   switch (note->descsz)
 185     {
 186     case 136: /* This is sizeof(struct elf_prpsinfo) on Linux/kvx.  */
 187       elf_tdata (abfd)->core->pid = bfd_get_32 (abfd, note->descdata + 24);
 188       elf_tdata (abfd)->core->program
 189         = _bfd_elfcore_strndup (abfd, note->descdata + 40, 16);
 190       elf_tdata (abfd)->core->command
 191         = _bfd_elfcore_strndup (abfd, note->descdata + 56, 80);
 192       break;
 193
 194     default:
 195       return false;
 196     }
 197
 198   /* Note that for some reason, a spurious space is tacked
 199      onto the end of the args in some (at least one anyway)
 200      implementations, so strip it off if it exists.  */
 201
 202   {
 203     char *command = elf_tdata (abfd)->core->command;
 204     int n = strlen (command);
 205
 206     if (n > 0 && command[n - 1] == ' ')
 207       command[n - 1] = 0;
 208   }
 209
 210   return true;
 211 }