xref: /netbsd-src/external/gpl3/binutils.old/dist/bfd/elf32-mt.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* Morpho Technologies MT specific support for 32-bit ELF
2    Copyright (C) 2001-2016 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 (bfd_link_relocatable (info))
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 	      (*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 	      (*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 	    (*info->callbacks->warning) (info, msg, name, input_bfd,
413 					 input_section, rel->r_offset);
414 	}
415     }
416 
417   return TRUE;
418 }
419 
420 /* Look through the relocs for a section during the first phase.
421    Since we don't do .gots or .plts, we just need to consider the
422    virtual table relocs for gc.  */
423 
424 static bfd_boolean
425 mt_elf_check_relocs
426     (bfd *                     abfd,
427      struct bfd_link_info *    info,
428      asection *                sec,
429      const Elf_Internal_Rela * relocs)
430 {
431   Elf_Internal_Shdr *           symtab_hdr;
432   struct elf_link_hash_entry ** sym_hashes;
433   const Elf_Internal_Rela *     rel;
434   const Elf_Internal_Rela *     rel_end;
435 
436   if (bfd_link_relocatable (info))
437     return TRUE;
438 
439   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
440   sym_hashes = elf_sym_hashes (abfd);
441 
442   rel_end = relocs + sec->reloc_count;
443   for (rel = relocs; rel < rel_end; rel++)
444     {
445       struct elf_link_hash_entry *h;
446       unsigned long r_symndx;
447 
448       r_symndx = ELF32_R_SYM (rel->r_info);
449       if (r_symndx < symtab_hdr->sh_info)
450         h = NULL;
451       else
452 	{
453 	  h = sym_hashes[r_symndx - symtab_hdr->sh_info];
454 	  while (h->root.type == bfd_link_hash_indirect
455 		 || h->root.type == bfd_link_hash_warning)
456 	    h = (struct elf_link_hash_entry *) h->root.u.i.link;
457 
458 	  /* PR15323, ref flags aren't set for references in the same
459 	     object.  */
460 	  h->root.non_ir_ref = 1;
461 	}
462     }
463 
464   return TRUE;
465 }
466 
467 /* Return the MACH for an e_flags value.  */
468 
469 static int
470 elf32_mt_machine (bfd *abfd)
471 {
472   switch (elf_elfheader (abfd)->e_flags & EF_MT_CPU_MASK)
473     {
474     case EF_MT_CPU_MRISC:	return bfd_mach_ms1;
475     case EF_MT_CPU_MRISC2:	return bfd_mach_mrisc2;
476     case EF_MT_CPU_MS2:		return bfd_mach_ms2;
477     }
478 
479   return bfd_mach_ms1;
480 }
481 
482 static bfd_boolean
483 mt_elf_object_p (bfd * abfd)
484 {
485   bfd_default_set_arch_mach (abfd, bfd_arch_mt, elf32_mt_machine (abfd));
486 
487   return TRUE;
488 }
489 
490 /* Function to set the ELF flag bits.  */
491 
492 static bfd_boolean
493 mt_elf_set_private_flags (bfd *    abfd,
494 			   flagword flags)
495 {
496   elf_elfheader (abfd)->e_flags = flags;
497   elf_flags_init (abfd) = TRUE;
498   return TRUE;
499 }
500 
501 /* Merge backend specific data from an object file to the output
502    object file when linking.  */
503 
504 static bfd_boolean
505 mt_elf_merge_private_bfd_data (bfd * ibfd, bfd * obfd)
506 {
507   flagword     old_flags, new_flags;
508   bfd_boolean  ok = TRUE;
509 
510   /* Check if we have the same endianness.  */
511   if (_bfd_generic_verify_endian_match (ibfd, obfd) == FALSE)
512     return FALSE;
513 
514   /* If they're not both mt, then merging is meaningless, so just
515      don't do it.  */
516   if (strcmp (ibfd->arch_info->arch_name, "mt") != 0)
517     return TRUE;
518   if (strcmp (obfd->arch_info->arch_name, "mt") != 0)
519     return TRUE;
520 
521   new_flags = elf_elfheader (ibfd)->e_flags;
522   old_flags = elf_elfheader (obfd)->e_flags;
523 
524 #ifdef DEBUG
525   _bfd_error_handler ("%B: old_flags = 0x%.8lx, new_flags = 0x%.8lx, init = %s",
526 		      ibfd, old_flags, new_flags, elf_flags_init (obfd) ? "yes" : "no");
527 #endif
528 
529   if (!elf_flags_init (obfd))
530     {
531       old_flags = new_flags;
532       elf_flags_init (obfd) = TRUE;
533     }
534   else if ((new_flags & EF_MT_CPU_MASK) != (old_flags & EF_MT_CPU_MASK))
535     {
536       /* CPU has changed.  This is invalid, because MRISC, MRISC2 and
537 	 MS2 are not subsets of each other.   */
538       ok = FALSE;
539     }
540 
541   if (ok)
542     {
543       obfd->arch_info = ibfd->arch_info;
544       elf_elfheader (obfd)->e_flags = old_flags;
545     }
546 
547   return ok;
548 }
549 
550 static bfd_boolean
551 mt_elf_print_private_bfd_data (bfd * abfd, void * ptr)
552 {
553   FILE *   file = (FILE *) ptr;
554   flagword flags;
555 
556   BFD_ASSERT (abfd != NULL && ptr != NULL);
557 
558   /* Print normal ELF private data.  */
559   _bfd_elf_print_private_bfd_data (abfd, ptr);
560 
561   flags = elf_elfheader (abfd)->e_flags;
562   fprintf (file, _("private flags = 0x%lx:"), (unsigned long) flags);
563 
564   switch (flags & EF_MT_CPU_MASK)
565     {
566     default:
567     case EF_MT_CPU_MRISC:   fprintf (file, " ms1-16-002");	break;
568     case EF_MT_CPU_MRISC2:  fprintf (file, " ms1-16-003");	break;
569     case EF_MT_CPU_MS2:     fprintf (file, " ms2");	break;
570     }
571 
572   fputc ('\n', file);
573 
574   return TRUE;
575 }
576 
577 
578 #define TARGET_BIG_SYM	 mt_elf32_vec
579 #define TARGET_BIG_NAME  "elf32-mt"
580 
581 #define ELF_ARCH	 bfd_arch_mt
582 #define ELF_MACHINE_CODE EM_MT
583 #define ELF_MAXPAGESIZE  1 /* No pages on the MT.  */
584 
585 #define elf_info_to_howto_rel			NULL
586 #define elf_info_to_howto			mt_info_to_howto_rela
587 
588 #define elf_backend_relocate_section		mt_elf_relocate_section
589 
590 #define bfd_elf32_bfd_reloc_type_lookup	        mt_reloc_type_lookup
591 #define bfd_elf32_bfd_reloc_name_lookup   mt_reloc_name_lookup
592 
593 #define elf_backend_check_relocs                mt_elf_check_relocs
594 #define elf_backend_object_p		        mt_elf_object_p
595 #define elf_backend_rela_normal			1
596 
597 #define elf_backend_can_gc_sections		1
598 
599 #define bfd_elf32_bfd_set_private_flags		mt_elf_set_private_flags
600 #define bfd_elf32_bfd_merge_private_bfd_data	mt_elf_merge_private_bfd_data
601 #define bfd_elf32_bfd_print_private_bfd_data	mt_elf_print_private_bfd_data
602 
603 #include "elf32-target.h"
604