1 /* D10V-specific support for 32-bit ELF
2    Copyright 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
3    Free Software Foundation, Inc.
4    Contributed by Martin Hunt (hunt@cygnus.com).
5 
6    This file is part of BFD, the Binary File Descriptor library.
7 
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 2 of the License, or
11    (at your option) any later version.
12 
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17 
18    You should have received a copy of the GNU General Public License
19    along with this program; if not, write to the Free Software
20    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21    MA 02110-1301, USA.  */
22 
23 #include "bfd.h"
24 #include "sysdep.h"
25 #include "libbfd.h"
26 #include "elf-bfd.h"
27 #include "elf/d10v.h"
28 
29 /* Use REL instead of RELA to save space.  */
30 #define USE_REL	1
31 
32 static reloc_howto_type elf_d10v_howto_table[] =
33 {
34   /* This reloc does nothing.  */
35   HOWTO (R_D10V_NONE,		/* Type.  */
36 	 0,			/* Rightshift.  */
37 	 2,			/* Size (0 = byte, 1 = short, 2 = long).  */
38 	 32,			/* Bitsize.  */
39 	 FALSE,			/* PC_relative.  */
40 	 0,			/* Bitpos.  */
41 	 complain_overflow_dont,/* Complain_on_overflow.  */
42 	 bfd_elf_generic_reloc, /* Special_function.  */
43 	 "R_D10V_NONE",		/* Name.  */
44 	 FALSE,			/* Partial_inplace.  */
45 	 0,			/* Src_mask.  */
46 	 0,			/* Dst_mask.  */
47 	 FALSE),		/* PCrel_offset.  */
48 
49   /* An PC Relative 10-bit relocation, shifted by 2, right container.  */
50   HOWTO (R_D10V_10_PCREL_R,	/* Type.  */
51 	 2,	                /* Rightshift.  */
52 	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
53 	 8,	                /* Bitsize.  */
54 	 TRUE,	        	/* PC_relative.  */
55 	 0,	                /* Bitpos.  */
56 	 complain_overflow_signed, /* Complain_on_overflow.  */
57 	 bfd_elf_generic_reloc, /* Special_function.  */
58 	 "R_D10V_10_PCREL_R",	/* Name.  */
59 	 FALSE,	        	/* Partial_inplace.  */
60 	 0xff,			/* Src_mask.  */
61 	 0xff,   		/* Dst_mask.  */
62 	 TRUE),			/* PCrel_offset.  */
63 
64   /* An PC Relative 10-bit relocation, shifted by 2, left container.  */
65   HOWTO (R_D10V_10_PCREL_L,	/* Type.  */
66 	 2,	                /* Rightshift.  */
67 	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
68 	 8,	                /* Bitsize.  */
69 	 TRUE,	        	/* PC_relative.  */
70 	 15,	                /* Bitpos.  */
71 	 complain_overflow_signed, /* Complain_on_overflow.  */
72 	 bfd_elf_generic_reloc, /* Special_function.  */
73 	 "R_D10V_10_PCREL_L",	/* Name.  */
74 	 FALSE,	        	/* Partial_inplace.  */
75 	 0x07f8000,		/* Src_mask.  */
76 	 0x07f8000,   		/* Dst_mask.  */
77 	 TRUE),			/* PCrel_offset.  */
78 
79   /* A 16 bit absolute relocation.  */
80   HOWTO (R_D10V_16,		/* Type.  */
81 	 0,			/* Rightshift.  */
82 	 1,			/* Size (0 = byte, 1 = short, 2 = long).  */
83 	 16,			/* Bitsize.  */
84 	 FALSE,			/* PC_relative.  */
85 	 0,			/* Bitpos.  */
86 	 complain_overflow_dont,/* Complain_on_overflow.  */
87 	 bfd_elf_generic_reloc, /* Special_function.  */
88 	 "R_D10V_16",		/* Name.  */
89 	 FALSE,			/* Partial_inplace.  */
90 	 0xffff,		/* Src_mask.  */
91 	 0xffff,		/* Dst_mask.  */
92 	 FALSE),		/* PCrel_offset.  */
93 
94   /* An 18 bit absolute relocation, right shifted 2.  */
95   HOWTO (R_D10V_18,		/* Type.  */
96 	 2,			/* Rightshift.  */
97 	 1,			/* Size (0 = byte, 1 = short, 2 = long).  */
98 	 16,			/* Bitsize.  */
99 	 FALSE,			/* PC_relative.  */
100 	 0,			/* Bitpos.  */
101 	 complain_overflow_dont, /* Complain_on_overflow.  */
102 	 bfd_elf_generic_reloc, /* Special_function.  */
103 	 "R_D10V_18",		/* Name.  */
104 	 FALSE,			/* Partial_inplace.  */
105 	 0xffff,		/* Src_mask.  */
106 	 0xffff,		/* Dst_mask.  */
107 	 FALSE),		/* PCrel_offset.  */
108 
109   /* A relative 18 bit relocation, right shifted by 2.  */
110   HOWTO (R_D10V_18_PCREL,	/* Type.  */
111 	 2,			/* Rightshift.  */
112 	 2,			/* Size (0 = byte, 1 = short, 2 = long).  */
113 	 16,			/* Bitsize.  */
114 	 TRUE,			/* PC_relative.  */
115 	 0,			/* Bitpos.  */
116 	 complain_overflow_signed, /* Complain_on_overflow.  */
117 	 bfd_elf_generic_reloc, /* Special_function.  */
118 	 "R_D10V_18_PCREL",	/* Name.  */
119 	 FALSE,			/* Partial_inplace.  */
120 	 0xffff,		/* Src_mask.  */
121 	 0xffff,		/* Dst_mask.  */
122 	 TRUE),			/* PCrel_offset.  */
123 
124   /* A 32 bit absolute relocation.  */
125   HOWTO (R_D10V_32,		/* Type.  */
126 	 0,			/* Rightshift.  */
127 	 2,			/* Size (0 = byte, 1 = short, 2 = long).  */
128 	 32,			/* Bitsize.  */
129 	 FALSE,			/* PC_relative.  */
130 	 0,			/* Bitpos.  */
131 	 complain_overflow_dont,/* Complain_on_overflow.  */
132 	 bfd_elf_generic_reloc, /* Special_function.  */
133 	 "R_D10V_32",		/* Name.  */
134 	 FALSE,			/* Partial_inplace.  */
135 	 0xffffffff,		/* Src_mask.  */
136 	 0xffffffff,		/* Dst_mask.  */
137 	 FALSE),		/* PCrel_offset.  */
138 
139   /* GNU extension to record C++ vtable hierarchy.  */
140   HOWTO (R_D10V_GNU_VTINHERIT,	/* Type.  */
141 	 0,                     /* Rightshift.  */
142 	 2,                     /* Size (0 = byte, 1 = short, 2 = long).  */
143 	 0,                     /* Bitsize.  */
144 	 FALSE,                 /* PC_relative.  */
145 	 0,                     /* Bitpos.  */
146 	 complain_overflow_dont,/* Complain_on_overflow.  */
147 	 NULL,                  /* Special_function.  */
148 	 "R_D10V_GNU_VTINHERIT",/* Name.  */
149 	 FALSE,                 /* Partial_inplace.  */
150 	 0,                     /* Src_mask.  */
151 	 0,                     /* Dst_mask.  */
152 	 FALSE),                /* PCrel_offset.  */
153 
154   /* GNU extension to record C++ vtable member usage.  */
155   HOWTO (R_D10V_GNU_VTENTRY,    /* Type.  */
156 	 0,                     /* Rightshift.  */
157 	 2,                     /* Size (0 = byte, 1 = short, 2 = long).  */
158 	 0,                     /* Bitsize.  */
159 	 FALSE,                 /* PC_relative.  */
160 	 0,                     /* Bitpos.  */
161 	 complain_overflow_dont,/* Complain_on_overflow.  */
162 	 _bfd_elf_rel_vtable_reloc_fn,  /* Special_function.  */
163 	 "R_D10V_GNU_VTENTRY",  /* Name.  */
164 	 FALSE,                 /* Partial_inplace.  */
165 	 0,                     /* Src_mask.  */
166 	 0,                     /* Dst_mask.  */
167 	 FALSE),                /* PCrel_offset.  */
168 };
169 
170 /* Map BFD reloc types to D10V ELF reloc types.  */
171 
172 struct d10v_reloc_map
173 {
174   bfd_reloc_code_real_type bfd_reloc_val;
175   unsigned char elf_reloc_val;
176 };
177 
178 static const struct d10v_reloc_map d10v_reloc_map[] =
179 {
180   { BFD_RELOC_NONE, R_D10V_NONE, },
181   { BFD_RELOC_D10V_10_PCREL_R, R_D10V_10_PCREL_R },
182   { BFD_RELOC_D10V_10_PCREL_L, R_D10V_10_PCREL_L },
183   { BFD_RELOC_16, R_D10V_16 },
184   { BFD_RELOC_D10V_18, R_D10V_18 },
185   { BFD_RELOC_D10V_18_PCREL, R_D10V_18_PCREL },
186   { BFD_RELOC_32, R_D10V_32 },
187   { BFD_RELOC_VTABLE_INHERIT, R_D10V_GNU_VTINHERIT },
188   { BFD_RELOC_VTABLE_ENTRY, R_D10V_GNU_VTENTRY },
189 };
190 
191 static reloc_howto_type *
192 bfd_elf32_bfd_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
193 				 bfd_reloc_code_real_type code)
194 {
195   unsigned int i;
196 
197   for (i = 0;
198        i < sizeof (d10v_reloc_map) / sizeof (struct d10v_reloc_map);
199        i++)
200     if (d10v_reloc_map[i].bfd_reloc_val == code)
201       return &elf_d10v_howto_table[d10v_reloc_map[i].elf_reloc_val];
202 
203   return NULL;
204 }
205 
206 /* Set the howto pointer for an D10V ELF reloc.  */
207 
208 static void
209 d10v_info_to_howto_rel (bfd *abfd ATTRIBUTE_UNUSED,
210 			arelent *cache_ptr,
211 			Elf_Internal_Rela *dst)
212 {
213   unsigned int r_type;
214 
215   r_type = ELF32_R_TYPE (dst->r_info);
216   BFD_ASSERT (r_type < (unsigned int) R_D10V_max);
217   cache_ptr->howto = &elf_d10v_howto_table[r_type];
218 }
219 
220 static asection *
221 elf32_d10v_gc_mark_hook (asection *sec,
222 			 struct bfd_link_info *info ATTRIBUTE_UNUSED,
223 			 Elf_Internal_Rela *rel,
224 			 struct elf_link_hash_entry *h,
225 			 Elf_Internal_Sym *sym)
226 {
227   if (h != NULL)
228     {
229       switch (ELF32_R_TYPE (rel->r_info))
230       {
231       case R_D10V_GNU_VTINHERIT:
232       case R_D10V_GNU_VTENTRY:
233         break;
234 
235       default:
236         switch (h->root.type)
237           {
238           case bfd_link_hash_defined:
239           case bfd_link_hash_defweak:
240             return h->root.u.def.section;
241 
242           case bfd_link_hash_common:
243             return h->root.u.c.p->section;
244 
245 	  default:
246 	    break;
247           }
248        }
249      }
250    else
251      return bfd_section_from_elf_index (sec->owner, sym->st_shndx);
252 
253   return NULL;
254 }
255 
256 static bfd_boolean
257 elf32_d10v_gc_sweep_hook (bfd *abfd ATTRIBUTE_UNUSED,
258 			  struct bfd_link_info *info ATTRIBUTE_UNUSED,
259 			  asection *sec ATTRIBUTE_UNUSED,
260 			  const Elf_Internal_Rela *relocs ATTRIBUTE_UNUSED)
261 {
262   /* We don't use got and plt entries for d10v.  */
263   return TRUE;
264 }
265 
266 /* Look through the relocs for a section during the first phase.
267    Since we don't do .gots or .plts, we just need to consider the
268    virtual table relocs for gc.  */
269 
270 static bfd_boolean
271 elf32_d10v_check_relocs (bfd *abfd,
272 			 struct bfd_link_info *info,
273 			 asection *sec,
274 			 const Elf_Internal_Rela *relocs)
275 {
276   Elf_Internal_Shdr *symtab_hdr;
277   struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
278   const Elf_Internal_Rela *rel;
279   const Elf_Internal_Rela *rel_end;
280 
281   if (info->relocatable)
282     return TRUE;
283 
284   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
285   sym_hashes = elf_sym_hashes (abfd);
286   sym_hashes_end = sym_hashes + symtab_hdr->sh_size/sizeof (Elf32_External_Sym);
287   if (!elf_bad_symtab (abfd))
288     sym_hashes_end -= symtab_hdr->sh_info;
289 
290   rel_end = relocs + sec->reloc_count;
291   for (rel = relocs; rel < rel_end; rel++)
292     {
293       struct elf_link_hash_entry *h;
294       unsigned long r_symndx;
295 
296       r_symndx = ELF32_R_SYM (rel->r_info);
297       if (r_symndx < symtab_hdr->sh_info)
298         h = NULL;
299       else
300 	{
301 	  h = sym_hashes[r_symndx - symtab_hdr->sh_info];
302 	  while (h->root.type == bfd_link_hash_indirect
303 		 || h->root.type == bfd_link_hash_warning)
304 	    h = (struct elf_link_hash_entry *) h->root.u.i.link;
305 	}
306 
307       switch (ELF32_R_TYPE (rel->r_info))
308         {
309         /* This relocation describes the C++ object vtable hierarchy.
310            Reconstruct it for later use during GC.  */
311         case R_D10V_GNU_VTINHERIT:
312           if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
313             return FALSE;
314           break;
315 
316         /* This relocation describes which C++ vtable entries are actually
317            used.  Record for later use during GC.  */
318         case R_D10V_GNU_VTENTRY:
319           if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_offset))
320             return FALSE;
321           break;
322         }
323     }
324 
325   return TRUE;
326 }
327 
328 static bfd_vma
329 extract_rel_addend (bfd *abfd,
330 		    bfd_byte *where,
331 		    reloc_howto_type *howto)
332 {
333   bfd_vma insn, val;
334 
335   switch (howto->size)
336     {
337     case 0:
338       insn = bfd_get_8 (abfd, where);
339       break;
340     case 1:
341       insn = bfd_get_16 (abfd, where);
342       break;
343     case 2:
344       insn = bfd_get_32 (abfd, where);
345       break;
346     default:
347       abort ();
348     }
349 
350   val = (insn & howto->dst_mask) >> howto->bitpos << howto->rightshift;
351   /* We should really be testing for signed addends here, but we don't
352      have that info directly in the howto.  */
353   if (howto->pc_relative)
354     {
355       bfd_vma sign;
356       sign = howto->dst_mask & (~howto->dst_mask >> 1 | ~(-(bfd_vma) 1 >> 1));
357       sign = sign >> howto->bitpos << howto->rightshift;
358       val = (val ^ sign) - sign;
359     }
360   return val;
361 }
362 
363 static void
364 insert_rel_addend (bfd *abfd,
365 		   bfd_byte *where,
366 		   reloc_howto_type *howto,
367 		   bfd_vma addend)
368 {
369   bfd_vma insn;
370 
371   addend = (addend >> howto->rightshift << howto->bitpos) & howto->dst_mask;
372   insn = ~howto->dst_mask;
373   switch (howto->size)
374     {
375     case 0:
376       insn &= bfd_get_8 (abfd, where);
377       insn |= addend;
378       bfd_put_8 (abfd, insn, where);
379       break;
380     case 1:
381       insn &= bfd_get_16 (abfd, where);
382       insn |= addend;
383       bfd_put_16 (abfd, insn, where);
384       break;
385     case 2:
386       insn &= bfd_get_32 (abfd, where);
387       insn |= addend;
388       bfd_put_32 (abfd, insn, where);
389       break;
390     default:
391       abort ();
392     }
393 }
394 
395 /* Relocate a D10V ELF section.  */
396 
397 static bfd_boolean
398 elf32_d10v_relocate_section (bfd *output_bfd,
399 			     struct bfd_link_info *info,
400 			     bfd *input_bfd,
401 			     asection *input_section,
402 			     bfd_byte *contents,
403 			     Elf_Internal_Rela *relocs,
404 			     Elf_Internal_Sym *local_syms,
405 			     asection **local_sections)
406 {
407   Elf_Internal_Shdr *symtab_hdr;
408   struct elf_link_hash_entry **sym_hashes;
409   Elf_Internal_Rela *rel, *relend;
410   const char *name;
411 
412   symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
413   sym_hashes = elf_sym_hashes (input_bfd);
414 
415   rel = relocs;
416   relend = relocs + input_section->reloc_count;
417   for (; rel < relend; rel++)
418     {
419       int r_type;
420       reloc_howto_type *howto;
421       unsigned long r_symndx;
422       Elf_Internal_Sym *sym;
423       asection *sec;
424       struct elf_link_hash_entry *h;
425       bfd_vma relocation;
426       bfd_reloc_status_type r;
427 
428       r_symndx = ELF32_R_SYM (rel->r_info);
429       r_type = ELF32_R_TYPE (rel->r_info);
430 
431       if (r_type == R_D10V_GNU_VTENTRY
432           || r_type == R_D10V_GNU_VTINHERIT)
433         continue;
434 
435       howto = elf_d10v_howto_table + r_type;
436 
437       if (info->relocatable)
438 	{
439 	  bfd_vma val;
440 	  bfd_byte *where;
441 
442 	  /* This is a relocatable link.  We don't have to change
443 	     anything, unless the reloc is against a section symbol,
444 	     in which case we have to adjust according to where the
445 	     section symbol winds up in the output section.  */
446 	  if (r_symndx >= symtab_hdr->sh_info)
447 	    continue;
448 
449 	  sym = local_syms + r_symndx;
450 	  if (ELF_ST_TYPE (sym->st_info) != STT_SECTION)
451 	    continue;
452 
453 	  sec = local_sections[r_symndx];
454 	  val = sec->output_offset;
455 	  if (val == 0)
456 	    continue;
457 
458 	  where = contents + rel->r_offset;
459 	  val += extract_rel_addend (input_bfd, where, howto);
460 	  insert_rel_addend (input_bfd, where, howto, val);
461 	  continue;
462 	}
463 
464       /* This is a final link.  */
465       h = NULL;
466       sym = NULL;
467       sec = NULL;
468       if (r_symndx < symtab_hdr->sh_info)
469 	{
470 	  sym = local_syms + r_symndx;
471 	  sec = local_sections[r_symndx];
472 	  relocation = (sec->output_section->vma
473 			+ sec->output_offset
474 			+ sym->st_value);
475 	  if ((sec->flags & SEC_MERGE)
476 	      && ELF_ST_TYPE (sym->st_info) == STT_SECTION)
477 	    {
478 	      asection *msec;
479 	      bfd_vma addend;
480 	      bfd_byte *where = contents + rel->r_offset;
481 
482 	      addend = extract_rel_addend (input_bfd, where, howto);
483 	      msec = sec;
484 	      addend = _bfd_elf_rel_local_sym (output_bfd, sym, &msec, addend);
485 	      addend -= relocation;
486 	      addend += msec->output_section->vma + msec->output_offset;
487 	      insert_rel_addend (input_bfd, where, howto, addend);
488 	    }
489 	}
490       else
491 	{
492 	  bfd_boolean unresolved_reloc, warned;
493 
494 	  RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
495 				   r_symndx, symtab_hdr, sym_hashes,
496 				   h, sec, relocation,
497 				   unresolved_reloc, warned);
498 	}
499 
500       if (h != NULL)
501 	name = h->root.root.string;
502       else
503 	{
504 	  name = (bfd_elf_string_from_elf_section
505 		  (input_bfd, symtab_hdr->sh_link, sym->st_name));
506 	  if (name == NULL || *name == '\0')
507 	    name = bfd_section_name (input_bfd, sec);
508 	}
509 
510       r = _bfd_final_link_relocate (howto, input_bfd, input_section,
511                                     contents, rel->r_offset,
512                                     relocation, (bfd_vma) 0);
513 
514       if (r != bfd_reloc_ok)
515 	{
516 	  const char * msg = (const char *) 0;
517 
518 	  switch (r)
519 	    {
520 	    case bfd_reloc_overflow:
521 	      if (!((*info->callbacks->reloc_overflow)
522 		    (info, (h ? &h->root : NULL), name, howto->name,
523 		     (bfd_vma) 0, input_bfd, input_section,
524 		     rel->r_offset)))
525 		return FALSE;
526 	      break;
527 
528 	    case bfd_reloc_undefined:
529 	      if (!((*info->callbacks->undefined_symbol)
530 		    (info, name, input_bfd, input_section,
531 		     rel->r_offset, TRUE)))
532 		return FALSE;
533 	      break;
534 
535 	    case bfd_reloc_outofrange:
536 	      msg = _("internal error: out of range error");
537 	      goto common_error;
538 
539 	    case bfd_reloc_notsupported:
540 	      msg = _("internal error: unsupported relocation error");
541 	      goto common_error;
542 
543 	    case bfd_reloc_dangerous:
544 	      msg = _("internal error: dangerous error");
545 	      goto common_error;
546 
547 	    default:
548 	      msg = _("internal error: unknown error");
549 	      /* fall through */
550 
551 	    common_error:
552 	      if (!((*info->callbacks->warning)
553 		    (info, msg, name, input_bfd, input_section,
554 		     rel->r_offset)))
555 		return FALSE;
556 	      break;
557 	    }
558 	}
559     }
560 
561   return TRUE;
562 }
563 #define ELF_ARCH		bfd_arch_d10v
564 #define ELF_MACHINE_CODE	EM_D10V
565 #define ELF_MACHINE_ALT1	EM_CYGNUS_D10V
566 #define ELF_MAXPAGESIZE		0x1000
567 
568 #define TARGET_BIG_SYM          bfd_elf32_d10v_vec
569 #define TARGET_BIG_NAME		"elf32-d10v"
570 
571 #define elf_info_to_howto	             0
572 #define elf_info_to_howto_rel	             d10v_info_to_howto_rel
573 #define elf_backend_object_p	             0
574 #define elf_backend_final_write_processing   0
575 #define elf_backend_gc_mark_hook             elf32_d10v_gc_mark_hook
576 #define elf_backend_gc_sweep_hook            elf32_d10v_gc_sweep_hook
577 #define elf_backend_check_relocs             elf32_d10v_check_relocs
578 #define elf_backend_relocate_section         elf32_d10v_relocate_section
579 #define elf_backend_can_gc_sections          1
580 
581 #include "elf32-target.h"
582