xref: /netbsd-src/external/gpl3/gdb/dist/bfd/elf32-mt.c (revision a24efa7dea9f1f56c3bdb15a927d3516792ace1c)
1 /* Morpho Technologies MT specific support for 32-bit ELF
2    Copyright (C) 2001-2015 Free Software Foundation, Inc.
3 
4    This file is part of BFD, the Binary File Descriptor library.
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., 59 Temple Place - Suite 330, Boston,
19    MA 02111-1307, USA.  */
20 
21 #include "sysdep.h"
22 #include "bfd.h"
23 #include "libbfd.h"
24 #include "elf-bfd.h"
25 #include "elf/mt.h"
26 
27 /* Prototypes.  */
28 static reloc_howto_type * mt_reloc_type_lookup
29   (bfd *, bfd_reloc_code_real_type);
30 
31 static void mt_info_to_howto_rela
32   (bfd *, arelent *, Elf_Internal_Rela *);
33 
34 static bfd_reloc_status_type mt_elf_relocate_hi16
35   (bfd *, Elf_Internal_Rela *, bfd_byte *, bfd_vma);
36 
37 static bfd_reloc_status_type mt_final_link_relocate
38   (reloc_howto_type *, bfd *, asection *, bfd_byte *,
39    Elf_Internal_Rela *, bfd_vma);
40 
41 static bfd_boolean mt_elf_relocate_section
42   (bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
43    Elf_Internal_Rela *, Elf_Internal_Sym *, asection **);
44 
45 /* Relocation tables.  */
46 static reloc_howto_type mt_elf_howto_table [] =
47 {
48   /* This reloc does nothing.  */
49   HOWTO (R_MT_NONE,           /* type */
50           0,                      /* rightshift */
51           3,                      /* size (0 = byte, 1 = short, 2 = long) */
52           0,                      /* bitsize */
53           FALSE,                  /* pc_relative */
54           0,                      /* bitpos */
55           complain_overflow_dont, /* complain_on_overflow */
56           bfd_elf_generic_reloc,  /* special_function */
57           "R_MT_NONE",          /* name */
58           FALSE,                  /* partial_inplace */
59           0 ,                     /* src_mask */
60           0,                      /* dst_mask */
61           FALSE),                 /* pcrel_offset */
62 
63   /* A 16 bit absolute relocation.  */
64   HOWTO (R_MT_16,             /* type */
65           0,                      /* rightshift */
66           2,                      /* size (0 = byte, 1 = short, 2 = long) */
67           16,                     /* bitsize */
68           FALSE,                  /* pc_relative */
69           0,                      /* bitpos */
70           complain_overflow_dont, /* complain_on_overflow */
71           bfd_elf_generic_reloc,  /* special_function */
72           "R_MT_16",            /* name */
73           FALSE,                  /* partial_inplace */
74           0 ,                     /* src_mask */
75           0xffff,                 /* dst_mask */
76           FALSE),                 /* pcrel_offset */
77 
78   /* A 32 bit absolute relocation.  */
79   HOWTO (R_MT_32,             /* type */
80           0,                      /* rightshift */
81           2,                      /* size (0 = byte, 1 = short, 2 = long) */
82           32,                     /* bitsize */
83           FALSE,                  /* pc_relative */
84           0,                      /* bitpos */
85           complain_overflow_dont, /* complain_on_overflow */
86           bfd_elf_generic_reloc,  /* special_function */
87           "R_MT_32",            /* name */
88           FALSE,                  /* partial_inplace */
89           0 ,                     /* src_mask */
90           0xffffffff,             /* dst_mask */
91           FALSE),                 /* pcrel_offset */
92 
93   /* A 32 bit pc-relative relocation.  */
94   HOWTO (R_MT_32_PCREL,       /* type */
95           0,                      /* rightshift */
96           2,                      /* size (0 = byte, 1 = short, 2 = long) */
97           32,                     /* bitsize */
98           TRUE,                   /* pc_relative */
99           0,                      /* bitpos */
100           complain_overflow_dont, /* complain_on_overflow */
101           bfd_elf_generic_reloc,  /* special_function */
102           "R_MT_32_PCREL",    /* name */
103           FALSE,                  /* partial_inplace */
104           0 ,                     /* src_mask */
105           0xffffffff,             /* dst_mask */
106           TRUE),                  /* pcrel_offset */
107 
108   /* A 16 bit pc-relative relocation.  */
109   HOWTO (R_MT_PC16,           /* type */
110           0,                      /* rightshift */
111           2,                      /* size (0 = byte, 1 = short, 2 = long) */
112           16,                     /* bitsize */
113           TRUE,                   /* pc_relative */
114           0,                      /* bitpos */
115           complain_overflow_signed, /* complain_on_overflow */
116           bfd_elf_generic_reloc,  /* special_function */
117           "R_MT_PC16",          /* name */
118           FALSE,                  /* partial_inplace */
119           0,                      /* src_mask */
120           0xffff,                 /* dst_mask */
121           TRUE),                  /* pcrel_offset */
122 
123   /* high 16 bits of symbol value.  */
124   HOWTO (R_MT_HI16,          /* type */
125          0,                     /* rightshift */
126          2,                     /* size (0 = byte, 1 = short, 2 = long) */
127          16,                    /* bitsize */
128          FALSE,                 /* pc_relative */
129          0,                     /* bitpos */
130          complain_overflow_dont, /* complain_on_overflow */
131          bfd_elf_generic_reloc, /* special_function */
132          "R_MT_HI16",        /* name */
133          FALSE,                  /* partial_inplace */
134          0xffff0000,            /* src_mask */
135          0xffff0000,            /* dst_mask */
136          FALSE),                /* pcrel_offset */
137 
138   /* Low 16 bits of symbol value.  */
139   HOWTO (R_MT_LO16,          /* type */
140          0,                     /* rightshift */
141          2,                     /* size (0 = byte, 1 = short, 2 = long) */
142          16,                    /* bitsize */
143          FALSE,                 /* pc_relative */
144          0,                     /* bitpos */
145          complain_overflow_dont, /* complain_on_overflow */
146          bfd_elf_generic_reloc, /* special_function */
147          "R_MT_LO16",        /* name */
148          FALSE,                  /* partial_inplace */
149          0xffff,                /* src_mask */
150          0xffff,                /* dst_mask */
151          FALSE),                /* pcrel_offset */
152 };
153 
154 /* Map BFD reloc types to MT ELF reloc types.  */
155 
156 static reloc_howto_type *
157 mt_reloc_type_lookup
158     (bfd *                    abfd ATTRIBUTE_UNUSED,
159      bfd_reloc_code_real_type code)
160 {
161   /* Note that the mt_elf_howto_table is indxed by the R_
162      constants.  Thus, the order that the howto records appear in the
163      table *must* match the order of the relocation types defined in
164      include/elf/mt.h.  */
165 
166   switch (code)
167     {
168     case BFD_RELOC_NONE:
169       return &mt_elf_howto_table[ (int) R_MT_NONE];
170     case BFD_RELOC_16:
171       return &mt_elf_howto_table[ (int) R_MT_16];
172     case BFD_RELOC_32:
173       return &mt_elf_howto_table[ (int) R_MT_32];
174     case BFD_RELOC_32_PCREL:
175       return &mt_elf_howto_table[ (int) R_MT_32_PCREL];
176     case BFD_RELOC_16_PCREL:
177       return &mt_elf_howto_table[ (int) R_MT_PC16];
178     case BFD_RELOC_HI16:
179       return &mt_elf_howto_table[ (int) R_MT_HI16];
180     case BFD_RELOC_LO16:
181       return &mt_elf_howto_table[ (int) R_MT_LO16];
182 
183     default:
184       /* Pacify gcc -Wall.  */
185       return NULL;
186     }
187   return NULL;
188 }
189 
190 static reloc_howto_type *
191 mt_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
192 		      const char *r_name)
193 {
194   unsigned int i;
195 
196   for (i = 0;
197        i < sizeof (mt_elf_howto_table) / sizeof (mt_elf_howto_table[0]);
198        i++)
199     if (mt_elf_howto_table[i].name != NULL
200 	&& strcasecmp (mt_elf_howto_table[i].name, r_name) == 0)
201       return &mt_elf_howto_table[i];
202 
203   return NULL;
204 }
205 
206 bfd_reloc_status_type
207 mt_elf_relocate_hi16
208     (bfd *               input_bfd,
209      Elf_Internal_Rela * relhi,
210      bfd_byte *          contents,
211      bfd_vma             value)
212 {
213   bfd_vma insn;
214 
215   insn = bfd_get_32 (input_bfd, contents + relhi->r_offset);
216 
217   value += relhi->r_addend;
218   value >>= 16;
219   insn = ((insn & ~0xFFFF) | value);
220 
221   bfd_put_32 (input_bfd, insn, contents + relhi->r_offset);
222   return bfd_reloc_ok;
223 }
224 
225 /* XXX: The following code is the result of a cut&paste.  This unfortunate
226    practice is very widespread in the various target back-end files.  */
227 
228 /* Set the howto pointer for a MT ELF reloc.  */
229 
230 static void
231 mt_info_to_howto_rela
232     (bfd *               abfd ATTRIBUTE_UNUSED,
233      arelent *           cache_ptr,
234      Elf_Internal_Rela * dst)
235 {
236   unsigned int r_type;
237 
238   r_type = ELF32_R_TYPE (dst->r_info);
239   if (r_type >= (unsigned int) R_MT_max)
240     {
241       _bfd_error_handler (_("%B: invalid MT reloc number: %d"), abfd, r_type);
242       r_type = 0;
243     }
244   cache_ptr->howto = & mt_elf_howto_table [r_type];
245 }
246 
247 /* Perform a single relocation.  By default we use the standard BFD
248    routines.  */
249 
250 static bfd_reloc_status_type
251 mt_final_link_relocate
252     (reloc_howto_type *  howto,
253      bfd *               input_bfd,
254      asection *          input_section,
255      bfd_byte *          contents,
256      Elf_Internal_Rela * rel,
257      bfd_vma             relocation)
258 {
259   return _bfd_final_link_relocate (howto, input_bfd, input_section,
260 				   contents, rel->r_offset,
261 				   relocation, rel->r_addend);
262 }
263 
264 /* Relocate a MT ELF section.
265    There is some attempt to make this function usable for many architectures,
266    both USE_REL and USE_RELA ['twould be nice if such a critter existed],
267    if only to serve as a learning tool.
268 
269    The RELOCATE_SECTION function is called by the new ELF backend linker
270    to handle the relocations for a section.
271 
272    The relocs are always passed as Rela structures; if the section
273    actually uses Rel structures, the r_addend field will always be
274    zero.
275 
276    This function is responsible for adjusting the section contents as
277    necessary, and (if using Rela relocs and generating a relocatable
278    output file) adjusting the reloc addend as necessary.
279 
280    This function does not have to worry about setting the reloc
281    address or the reloc symbol index.
282 
283    LOCAL_SYMS is a pointer to the swapped in local symbols.
284 
285    LOCAL_SECTIONS is an array giving the section in the input file
286    corresponding to the st_shndx field of each local symbol.
287 
288    The global hash table entry for the global symbols can be found
289    via elf_sym_hashes (input_bfd).
290 
291    When generating relocatable output, this function must handle
292    STB_LOCAL/STT_SECTION symbols specially.  The output symbol is
293    going to be the section symbol corresponding to the output
294    section, which means that the addend must be adjusted
295    accordingly.  */
296 
297 static bfd_boolean
298 mt_elf_relocate_section
299     (bfd *                   output_bfd ATTRIBUTE_UNUSED,
300      struct bfd_link_info *  info,
301      bfd *                   input_bfd,
302      asection *              input_section,
303      bfd_byte *              contents,
304      Elf_Internal_Rela *     relocs,
305      Elf_Internal_Sym *      local_syms,
306      asection **             local_sections)
307 {
308   Elf_Internal_Shdr *           symtab_hdr;
309   struct elf_link_hash_entry ** sym_hashes;
310   Elf_Internal_Rela *           rel;
311   Elf_Internal_Rela *           relend;
312 
313   symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
314   sym_hashes = elf_sym_hashes (input_bfd);
315   relend     = relocs + input_section->reloc_count;
316 
317   for (rel = relocs; rel < relend; rel ++)
318     {
319       reloc_howto_type *           howto;
320       unsigned long                r_symndx;
321       Elf_Internal_Sym *           sym;
322       asection *                   sec;
323       struct elf_link_hash_entry * h;
324       bfd_vma                      relocation;
325       bfd_reloc_status_type        r;
326       const char *                 name = NULL;
327       int                          r_type;
328 
329       r_type = ELF32_R_TYPE (rel->r_info);
330 
331       r_symndx = ELF32_R_SYM (rel->r_info);
332 
333       howto  = mt_elf_howto_table + ELF32_R_TYPE (rel->r_info);
334       h      = NULL;
335       sym    = NULL;
336       sec    = NULL;
337 
338       if (r_symndx < symtab_hdr->sh_info)
339 	{
340 	  sym = local_syms + r_symndx;
341 	  sec = local_sections [r_symndx];
342 	  relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
343 
344 	  name = bfd_elf_string_from_elf_section
345 	    (input_bfd, symtab_hdr->sh_link, sym->st_name);
346 	  name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;
347 	}
348       else
349 	{
350 	  bfd_boolean unresolved_reloc;
351 	  bfd_boolean warned, ignored;
352 
353 	  RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
354 				   r_symndx, symtab_hdr, sym_hashes,
355 				   h, sec, relocation,
356 				   unresolved_reloc, warned, ignored);
357 
358 	  name = h->root.root.string;
359 	}
360 
361       if (sec != NULL && discarded_section (sec))
362 	RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
363 					 rel, 1, relend, howto, 0, contents);
364 
365       if (info->relocatable)
366 	continue;
367 
368       /* Finally, the sole MT-specific part.  */
369       switch (r_type)
370         {
371         case R_MT_HI16:
372           r = mt_elf_relocate_hi16 (input_bfd, rel, contents, relocation);
373           break;
374 	default:
375           r = mt_final_link_relocate (howto, input_bfd, input_section,
376 		        		  contents, rel, relocation);
377           break;
378         }
379 
380 
381       if (r != bfd_reloc_ok)
382 	{
383 	  const char * msg = (const char *) NULL;
384 
385 	  switch (r)
386 	    {
387 	    case bfd_reloc_overflow:
388 	      r = info->callbacks->reloc_overflow
389 		(info, (h ? &h->root : NULL), name, howto->name, (bfd_vma) 0,
390 		 input_bfd, input_section, rel->r_offset);
391 	      break;
392 
393 	    case bfd_reloc_undefined:
394 	      r = info->callbacks->undefined_symbol
395 		(info, name, input_bfd, input_section, rel->r_offset, TRUE);
396 	      break;
397 
398 	    case bfd_reloc_outofrange:
399 	      msg = _("internal error: out of range error");
400 	      break;
401 
402 	    case bfd_reloc_dangerous:
403 	      msg = _("internal error: dangerous relocation");
404 	      break;
405 
406 	    default:
407 	      msg = _("internal error: unknown error");
408 	      break;
409 	    }
410 
411 	  if (msg)
412 	    r = info->callbacks->warning
413 	      (info, msg, name, input_bfd, input_section, rel->r_offset);
414 
415 	  if (! r)
416 	    return FALSE;
417 	}
418     }
419 
420   return TRUE;
421 }
422 
423 /* Look through the relocs for a section during the first phase.
424    Since we don't do .gots or .plts, we just need to consider the
425    virtual table relocs for gc.  */
426 
427 static bfd_boolean
428 mt_elf_check_relocs
429     (bfd *                     abfd,
430      struct bfd_link_info *    info,
431      asection *                sec,
432      const Elf_Internal_Rela * relocs)
433 {
434   Elf_Internal_Shdr *           symtab_hdr;
435   struct elf_link_hash_entry ** sym_hashes;
436   const Elf_Internal_Rela *     rel;
437   const Elf_Internal_Rela *     rel_end;
438 
439   if (info->relocatable)
440     return TRUE;
441 
442   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
443   sym_hashes = elf_sym_hashes (abfd);
444 
445   rel_end = relocs + sec->reloc_count;
446   for (rel = relocs; rel < rel_end; rel++)
447     {
448       struct elf_link_hash_entry *h;
449       unsigned long r_symndx;
450 
451       r_symndx = ELF32_R_SYM (rel->r_info);
452       if (r_symndx < symtab_hdr->sh_info)
453         h = NULL;
454       else
455 	{
456 	  h = sym_hashes[r_symndx - symtab_hdr->sh_info];
457 	  while (h->root.type == bfd_link_hash_indirect
458 		 || h->root.type == bfd_link_hash_warning)
459 	    h = (struct elf_link_hash_entry *) h->root.u.i.link;
460 
461 	  /* PR15323, ref flags aren't set for references in the same
462 	     object.  */
463 	  h->root.non_ir_ref = 1;
464 	}
465     }
466 
467   return TRUE;
468 }
469 
470 /* Return the MACH for an e_flags value.  */
471 
472 static int
473 elf32_mt_machine (bfd *abfd)
474 {
475   switch (elf_elfheader (abfd)->e_flags & EF_MT_CPU_MASK)
476     {
477     case EF_MT_CPU_MRISC:	return bfd_mach_ms1;
478     case EF_MT_CPU_MRISC2:	return bfd_mach_mrisc2;
479     case EF_MT_CPU_MS2:		return bfd_mach_ms2;
480     }
481 
482   return bfd_mach_ms1;
483 }
484 
485 static bfd_boolean
486 mt_elf_object_p (bfd * abfd)
487 {
488   bfd_default_set_arch_mach (abfd, bfd_arch_mt, elf32_mt_machine (abfd));
489 
490   return TRUE;
491 }
492 
493 /* Function to set the ELF flag bits.  */
494 
495 static bfd_boolean
496 mt_elf_set_private_flags (bfd *    abfd,
497 			   flagword flags)
498 {
499   elf_elfheader (abfd)->e_flags = flags;
500   elf_flags_init (abfd) = TRUE;
501   return TRUE;
502 }
503 
504 /* Merge backend specific data from an object file to the output
505    object file when linking.  */
506 
507 static bfd_boolean
508 mt_elf_merge_private_bfd_data (bfd * ibfd, bfd * obfd)
509 {
510   flagword     old_flags, new_flags;
511   bfd_boolean  ok = TRUE;
512 
513   /* Check if we have the same endianness.  */
514   if (_bfd_generic_verify_endian_match (ibfd, obfd) == FALSE)
515     return FALSE;
516 
517   /* If they're not both mt, then merging is meaningless, so just
518      don't do it.  */
519   if (strcmp (ibfd->arch_info->arch_name, "mt") != 0)
520     return TRUE;
521   if (strcmp (obfd->arch_info->arch_name, "mt") != 0)
522     return TRUE;
523 
524   new_flags = elf_elfheader (ibfd)->e_flags;
525   old_flags = elf_elfheader (obfd)->e_flags;
526 
527 #ifdef DEBUG
528   _bfd_error_handler ("%B: old_flags = 0x%.8lx, new_flags = 0x%.8lx, init = %s",
529 		      ibfd, old_flags, new_flags, elf_flags_init (obfd) ? "yes" : "no");
530 #endif
531 
532   if (!elf_flags_init (obfd))
533     {
534       old_flags = new_flags;
535       elf_flags_init (obfd) = TRUE;
536     }
537   else if ((new_flags & EF_MT_CPU_MASK) != (old_flags & EF_MT_CPU_MASK))
538     {
539       /* CPU has changed.  This is invalid, because MRISC, MRISC2 and
540 	 MS2 are not subsets of each other.   */
541       ok = FALSE;
542     }
543 
544   if (ok)
545     {
546       obfd->arch_info = ibfd->arch_info;
547       elf_elfheader (obfd)->e_flags = old_flags;
548     }
549 
550   return ok;
551 }
552 
553 static bfd_boolean
554 mt_elf_print_private_bfd_data (bfd * abfd, void * ptr)
555 {
556   FILE *   file = (FILE *) ptr;
557   flagword flags;
558 
559   BFD_ASSERT (abfd != NULL && ptr != NULL);
560 
561   /* Print normal ELF private data.  */
562   _bfd_elf_print_private_bfd_data (abfd, ptr);
563 
564   flags = elf_elfheader (abfd)->e_flags;
565   fprintf (file, _("private flags = 0x%lx:"), (unsigned long) flags);
566 
567   switch (flags & EF_MT_CPU_MASK)
568     {
569     default:
570     case EF_MT_CPU_MRISC:   fprintf (file, " ms1-16-002");	break;
571     case EF_MT_CPU_MRISC2:  fprintf (file, " ms1-16-003");	break;
572     case EF_MT_CPU_MS2:     fprintf (file, " ms2");	break;
573     }
574 
575   fputc ('\n', file);
576 
577   return TRUE;
578 }
579 
580 
581 #define TARGET_BIG_SYM	 mt_elf32_vec
582 #define TARGET_BIG_NAME  "elf32-mt"
583 
584 #define ELF_ARCH	 bfd_arch_mt
585 #define ELF_MACHINE_CODE EM_MT
586 #define ELF_MAXPAGESIZE  1 /* No pages on the MT.  */
587 
588 #define elf_info_to_howto_rel			NULL
589 #define elf_info_to_howto			mt_info_to_howto_rela
590 
591 #define elf_backend_relocate_section		mt_elf_relocate_section
592 
593 #define bfd_elf32_bfd_reloc_type_lookup	        mt_reloc_type_lookup
594 #define bfd_elf32_bfd_reloc_name_lookup   mt_reloc_name_lookup
595 
596 #define elf_backend_check_relocs                mt_elf_check_relocs
597 #define elf_backend_object_p		        mt_elf_object_p
598 #define elf_backend_rela_normal			1
599 
600 #define elf_backend_can_gc_sections		1
601 
602 #define bfd_elf32_bfd_set_private_flags		mt_elf_set_private_flags
603 #define bfd_elf32_bfd_merge_private_bfd_data	mt_elf_merge_private_bfd_data
604 #define bfd_elf32_bfd_print_private_bfd_data	mt_elf_print_private_bfd_data
605 
606 #include "elf32-target.h"
607