1 /* D10V-specific support for 32-bit ELF
2    Copyright (C) 1996-2016 Free Software Foundation, Inc.
3    Contributed by Martin Hunt (hunt@cygnus.com).
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; if not, write to the Free Software
19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
20    MA 02110-1301, USA.  */
21 
22 #include "sysdep.h"
23 #include "bfd.h"
24 #include "libbfd.h"
25 #include "elf-bfd.h"
26 #include "elf/d10v.h"
27 
28 /* Use REL instead of RELA to save space.  */
29 #define USE_REL	1
30 
31 static reloc_howto_type elf_d10v_howto_table[] =
32 {
33   /* This reloc does nothing.  */
34   HOWTO (R_D10V_NONE,		/* Type.  */
35 	 0,			/* Rightshift.  */
36 	 3,			/* Size (0 = byte, 1 = short, 2 = long).  */
37 	 0,			/* Bitsize.  */
38 	 FALSE,			/* PC_relative.  */
39 	 0,			/* Bitpos.  */
40 	 complain_overflow_dont,/* Complain_on_overflow.  */
41 	 bfd_elf_generic_reloc, /* Special_function.  */
42 	 "R_D10V_NONE",		/* Name.  */
43 	 FALSE,			/* Partial_inplace.  */
44 	 0,			/* Src_mask.  */
45 	 0,			/* Dst_mask.  */
46 	 FALSE),		/* PCrel_offset.  */
47 
48   /* An PC Relative 10-bit relocation, shifted by 2, right container.  */
49   HOWTO (R_D10V_10_PCREL_R,	/* Type.  */
50 	 2,	                /* Rightshift.  */
51 	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
52 	 8,	                /* Bitsize.  */
53 	 TRUE,	        	/* PC_relative.  */
54 	 0,	                /* Bitpos.  */
55 	 complain_overflow_signed, /* Complain_on_overflow.  */
56 	 bfd_elf_generic_reloc, /* Special_function.  */
57 	 "R_D10V_10_PCREL_R",	/* Name.  */
58 	 FALSE,	        	/* Partial_inplace.  */
59 	 0xff,			/* Src_mask.  */
60 	 0xff,   		/* Dst_mask.  */
61 	 TRUE),			/* PCrel_offset.  */
62 
63   /* An PC Relative 10-bit relocation, shifted by 2, left container.  */
64   HOWTO (R_D10V_10_PCREL_L,	/* Type.  */
65 	 2,	                /* Rightshift.  */
66 	 2,	                /* Size (0 = byte, 1 = short, 2 = long).  */
67 	 8,	                /* Bitsize.  */
68 	 TRUE,	        	/* PC_relative.  */
69 	 15,	                /* Bitpos.  */
70 	 complain_overflow_signed, /* Complain_on_overflow.  */
71 	 bfd_elf_generic_reloc, /* Special_function.  */
72 	 "R_D10V_10_PCREL_L",	/* Name.  */
73 	 FALSE,	        	/* Partial_inplace.  */
74 	 0x07f8000,		/* Src_mask.  */
75 	 0x07f8000,   		/* Dst_mask.  */
76 	 TRUE),			/* PCrel_offset.  */
77 
78   /* A 16 bit absolute relocation.  */
79   HOWTO (R_D10V_16,		/* Type.  */
80 	 0,			/* Rightshift.  */
81 	 1,			/* Size (0 = byte, 1 = short, 2 = long).  */
82 	 16,			/* Bitsize.  */
83 	 FALSE,			/* PC_relative.  */
84 	 0,			/* Bitpos.  */
85 	 complain_overflow_dont,/* Complain_on_overflow.  */
86 	 bfd_elf_generic_reloc, /* Special_function.  */
87 	 "R_D10V_16",		/* Name.  */
88 	 FALSE,			/* Partial_inplace.  */
89 	 0xffff,		/* Src_mask.  */
90 	 0xffff,		/* Dst_mask.  */
91 	 FALSE),		/* PCrel_offset.  */
92 
93   /* An 18 bit absolute relocation, right shifted 2.  */
94   HOWTO (R_D10V_18,		/* Type.  */
95 	 2,			/* Rightshift.  */
96 	 1,			/* Size (0 = byte, 1 = short, 2 = long).  */
97 	 16,			/* Bitsize.  */
98 	 FALSE,			/* PC_relative.  */
99 	 0,			/* Bitpos.  */
100 	 complain_overflow_dont, /* Complain_on_overflow.  */
101 	 bfd_elf_generic_reloc, /* Special_function.  */
102 	 "R_D10V_18",		/* Name.  */
103 	 FALSE,			/* Partial_inplace.  */
104 	 0xffff,		/* Src_mask.  */
105 	 0xffff,		/* Dst_mask.  */
106 	 FALSE),		/* PCrel_offset.  */
107 
108   /* A relative 18 bit relocation, right shifted by 2.  */
109   HOWTO (R_D10V_18_PCREL,	/* Type.  */
110 	 2,			/* 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_D10V_18_PCREL",	/* Name.  */
118 	 FALSE,			/* Partial_inplace.  */
119 	 0xffff,		/* Src_mask.  */
120 	 0xffff,		/* Dst_mask.  */
121 	 TRUE),			/* PCrel_offset.  */
122 
123   /* A 32 bit absolute relocation.  */
124   HOWTO (R_D10V_32,		/* Type.  */
125 	 0,			/* Rightshift.  */
126 	 2,			/* Size (0 = byte, 1 = short, 2 = long).  */
127 	 32,			/* Bitsize.  */
128 	 FALSE,			/* PC_relative.  */
129 	 0,			/* Bitpos.  */
130 	 complain_overflow_dont,/* Complain_on_overflow.  */
131 	 bfd_elf_generic_reloc, /* Special_function.  */
132 	 "R_D10V_32",		/* Name.  */
133 	 FALSE,			/* Partial_inplace.  */
134 	 0xffffffff,		/* Src_mask.  */
135 	 0xffffffff,		/* Dst_mask.  */
136 	 FALSE),		/* PCrel_offset.  */
137 
138   /* GNU extension to record C++ vtable hierarchy.  */
139   HOWTO (R_D10V_GNU_VTINHERIT,	/* Type.  */
140 	 0,                     /* Rightshift.  */
141 	 2,                     /* Size (0 = byte, 1 = short, 2 = long).  */
142 	 0,                     /* Bitsize.  */
143 	 FALSE,                 /* PC_relative.  */
144 	 0,                     /* Bitpos.  */
145 	 complain_overflow_dont,/* Complain_on_overflow.  */
146 	 NULL,                  /* Special_function.  */
147 	 "R_D10V_GNU_VTINHERIT",/* Name.  */
148 	 FALSE,                 /* Partial_inplace.  */
149 	 0,                     /* Src_mask.  */
150 	 0,                     /* Dst_mask.  */
151 	 FALSE),                /* PCrel_offset.  */
152 
153   /* GNU extension to record C++ vtable member usage.  */
154   HOWTO (R_D10V_GNU_VTENTRY,    /* Type.  */
155 	 0,                     /* Rightshift.  */
156 	 2,                     /* Size (0 = byte, 1 = short, 2 = long).  */
157 	 0,                     /* Bitsize.  */
158 	 FALSE,                 /* PC_relative.  */
159 	 0,                     /* Bitpos.  */
160 	 complain_overflow_dont,/* Complain_on_overflow.  */
161 	 _bfd_elf_rel_vtable_reloc_fn,  /* Special_function.  */
162 	 "R_D10V_GNU_VTENTRY",  /* Name.  */
163 	 FALSE,                 /* Partial_inplace.  */
164 	 0,                     /* Src_mask.  */
165 	 0,                     /* Dst_mask.  */
166 	 FALSE),                /* PCrel_offset.  */
167 };
168 
169 /* Map BFD reloc types to D10V ELF reloc types.  */
170 
171 struct d10v_reloc_map
172 {
173   bfd_reloc_code_real_type bfd_reloc_val;
174   unsigned char elf_reloc_val;
175 };
176 
177 static const struct d10v_reloc_map d10v_reloc_map[] =
178 {
179   { BFD_RELOC_NONE, R_D10V_NONE, },
180   { BFD_RELOC_D10V_10_PCREL_R, R_D10V_10_PCREL_R },
181   { BFD_RELOC_D10V_10_PCREL_L, R_D10V_10_PCREL_L },
182   { BFD_RELOC_16, R_D10V_16 },
183   { BFD_RELOC_D10V_18, R_D10V_18 },
184   { BFD_RELOC_D10V_18_PCREL, R_D10V_18_PCREL },
185   { BFD_RELOC_32, R_D10V_32 },
186   { BFD_RELOC_VTABLE_INHERIT, R_D10V_GNU_VTINHERIT },
187   { BFD_RELOC_VTABLE_ENTRY, R_D10V_GNU_VTENTRY },
188 };
189 
190 static reloc_howto_type *
bfd_elf32_bfd_reloc_type_lookup(bfd * abfd ATTRIBUTE_UNUSED,bfd_reloc_code_real_type code)191 bfd_elf32_bfd_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
192 				 bfd_reloc_code_real_type code)
193 {
194   unsigned int i;
195 
196   for (i = 0;
197        i < sizeof (d10v_reloc_map) / sizeof (struct d10v_reloc_map);
198        i++)
199     if (d10v_reloc_map[i].bfd_reloc_val == code)
200       return &elf_d10v_howto_table[d10v_reloc_map[i].elf_reloc_val];
201 
202   return NULL;
203 }
204 
205 static reloc_howto_type *
bfd_elf32_bfd_reloc_name_lookup(bfd * abfd ATTRIBUTE_UNUSED,const char * r_name)206 bfd_elf32_bfd_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
207 				 const char *r_name)
208 {
209   unsigned int i;
210 
211   for (i = 0;
212        i < sizeof (elf_d10v_howto_table) / sizeof (elf_d10v_howto_table[0]);
213        i++)
214     if (elf_d10v_howto_table[i].name != NULL
215 	&& strcasecmp (elf_d10v_howto_table[i].name, r_name) == 0)
216       return &elf_d10v_howto_table[i];
217 
218   return NULL;
219 }
220 
221 /* Set the howto pointer for an D10V ELF reloc.  */
222 
223 static void
d10v_info_to_howto_rel(bfd * abfd ATTRIBUTE_UNUSED,arelent * cache_ptr,Elf_Internal_Rela * dst)224 d10v_info_to_howto_rel (bfd *abfd ATTRIBUTE_UNUSED,
225 			arelent *cache_ptr,
226 			Elf_Internal_Rela *dst)
227 {
228   unsigned int r_type;
229 
230   r_type = ELF32_R_TYPE (dst->r_info);
231   if (r_type >= (unsigned int) R_D10V_max)
232     {
233       _bfd_error_handler (_("%B: invalid D10V reloc number: %d"), abfd, r_type);
234       r_type = 0;
235     }
236   cache_ptr->howto = &elf_d10v_howto_table[r_type];
237 }
238 
239 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)240 elf32_d10v_gc_mark_hook (asection *sec,
241 			 struct bfd_link_info *info,
242 			 Elf_Internal_Rela *rel,
243 			 struct elf_link_hash_entry *h,
244 			 Elf_Internal_Sym *sym)
245 {
246   if (h != NULL)
247     switch (ELF32_R_TYPE (rel->r_info))
248       {
249       case R_D10V_GNU_VTINHERIT:
250       case R_D10V_GNU_VTENTRY:
251 	return NULL;
252       }
253 
254   return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
255 }
256 
257 /* Look through the relocs for a section during the first phase.
258    Since we don't do .gots or .plts, we just need to consider the
259    virtual table relocs for gc.  */
260 
261 static bfd_boolean
elf32_d10v_check_relocs(bfd * abfd,struct bfd_link_info * info,asection * sec,const Elf_Internal_Rela * relocs)262 elf32_d10v_check_relocs (bfd *abfd,
263 			 struct bfd_link_info *info,
264 			 asection *sec,
265 			 const Elf_Internal_Rela *relocs)
266 {
267   Elf_Internal_Shdr *symtab_hdr;
268   struct elf_link_hash_entry **sym_hashes;
269   const Elf_Internal_Rela *rel;
270   const Elf_Internal_Rela *rel_end;
271 
272   if (bfd_link_relocatable (info))
273     return TRUE;
274 
275   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
276   sym_hashes = elf_sym_hashes (abfd);
277 
278   rel_end = relocs + sec->reloc_count;
279   for (rel = relocs; rel < rel_end; rel++)
280     {
281       struct elf_link_hash_entry *h;
282       unsigned long r_symndx;
283 
284       r_symndx = ELF32_R_SYM (rel->r_info);
285       if (r_symndx < symtab_hdr->sh_info)
286         h = NULL;
287       else
288 	{
289 	  h = sym_hashes[r_symndx - symtab_hdr->sh_info];
290 	  while (h->root.type == bfd_link_hash_indirect
291 		 || h->root.type == bfd_link_hash_warning)
292 	    h = (struct elf_link_hash_entry *) h->root.u.i.link;
293 
294 	  /* PR15323, ref flags aren't set for references in the same
295 	     object.  */
296 	  h->root.non_ir_ref = 1;
297 	}
298 
299       switch (ELF32_R_TYPE (rel->r_info))
300         {
301         /* This relocation describes the C++ object vtable hierarchy.
302            Reconstruct it for later use during GC.  */
303         case R_D10V_GNU_VTINHERIT:
304           if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
305             return FALSE;
306           break;
307 
308         /* This relocation describes which C++ vtable entries are actually
309            used.  Record for later use during GC.  */
310         case R_D10V_GNU_VTENTRY:
311           BFD_ASSERT (h != NULL);
312           if (h != NULL
313               && !bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_offset))
314             return FALSE;
315           break;
316         }
317     }
318 
319   return TRUE;
320 }
321 
322 static bfd_vma
extract_rel_addend(bfd * abfd,bfd_byte * where,reloc_howto_type * howto)323 extract_rel_addend (bfd *abfd,
324 		    bfd_byte *where,
325 		    reloc_howto_type *howto)
326 {
327   bfd_vma insn, val;
328 
329   switch (howto->size)
330     {
331     case 0:
332       insn = bfd_get_8 (abfd, where);
333       break;
334     case 1:
335       insn = bfd_get_16 (abfd, where);
336       break;
337     case 2:
338       insn = bfd_get_32 (abfd, where);
339       break;
340     default:
341       abort ();
342     }
343 
344   val = (insn & howto->dst_mask) >> howto->bitpos << howto->rightshift;
345   /* We should really be testing for signed addends here, but we don't
346      have that info directly in the howto.  */
347   if (howto->pc_relative)
348     {
349       bfd_vma sign;
350       sign = howto->dst_mask & (~howto->dst_mask >> 1 | ~(-(bfd_vma) 1 >> 1));
351       sign = sign >> howto->bitpos << howto->rightshift;
352       val = (val ^ sign) - sign;
353     }
354   return val;
355 }
356 
357 static void
insert_rel_addend(bfd * abfd,bfd_byte * where,reloc_howto_type * howto,bfd_vma addend)358 insert_rel_addend (bfd *abfd,
359 		   bfd_byte *where,
360 		   reloc_howto_type *howto,
361 		   bfd_vma addend)
362 {
363   bfd_vma insn;
364 
365   addend = (addend >> howto->rightshift << howto->bitpos) & howto->dst_mask;
366   insn = ~howto->dst_mask;
367   switch (howto->size)
368     {
369     case 0:
370       insn &= bfd_get_8 (abfd, where);
371       insn |= addend;
372       bfd_put_8 (abfd, insn, where);
373       break;
374     case 1:
375       insn &= bfd_get_16 (abfd, where);
376       insn |= addend;
377       bfd_put_16 (abfd, insn, where);
378       break;
379     case 2:
380       insn &= bfd_get_32 (abfd, where);
381       insn |= addend;
382       bfd_put_32 (abfd, insn, where);
383       break;
384     default:
385       abort ();
386     }
387 }
388 
389 /* Relocate a D10V ELF section.  */
390 
391 static bfd_boolean
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)392 elf32_d10v_relocate_section (bfd *output_bfd,
393 			     struct bfd_link_info *info,
394 			     bfd *input_bfd,
395 			     asection *input_section,
396 			     bfd_byte *contents,
397 			     Elf_Internal_Rela *relocs,
398 			     Elf_Internal_Sym *local_syms,
399 			     asection **local_sections)
400 {
401   Elf_Internal_Shdr *symtab_hdr;
402   struct elf_link_hash_entry **sym_hashes;
403   Elf_Internal_Rela *rel, *relend;
404   const char *name;
405 
406   symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
407   sym_hashes = elf_sym_hashes (input_bfd);
408 
409   rel = relocs;
410   relend = relocs + input_section->reloc_count;
411   for (; rel < relend; rel++)
412     {
413       int r_type;
414       reloc_howto_type *howto;
415       unsigned long r_symndx;
416       Elf_Internal_Sym *sym;
417       asection *sec;
418       struct elf_link_hash_entry *h;
419       bfd_vma relocation;
420       bfd_reloc_status_type r;
421 
422       r_symndx = ELF32_R_SYM (rel->r_info);
423       r_type = ELF32_R_TYPE (rel->r_info);
424 
425       if (r_type == R_D10V_GNU_VTENTRY
426           || r_type == R_D10V_GNU_VTINHERIT)
427         continue;
428 
429       howto = elf_d10v_howto_table + r_type;
430       h = NULL;
431       sym = NULL;
432       sec = NULL;
433       if (r_symndx < symtab_hdr->sh_info)
434 	{
435 	  sym = local_syms + r_symndx;
436 	  sec = local_sections[r_symndx];
437 	  relocation = (sec->output_section->vma
438 			+ sec->output_offset
439 			+ sym->st_value);
440 	  if (ELF_ST_TYPE (sym->st_info) == STT_SECTION
441 	      && ((sec->flags & SEC_MERGE) != 0
442 		  || (bfd_link_relocatable (info)
443 		      && sec->output_offset != 0)))
444 	    {
445 	      bfd_vma addend;
446 	      bfd_byte *where = contents + rel->r_offset;
447 
448 	      addend = extract_rel_addend (input_bfd, where, howto);
449 
450 	      if (bfd_link_relocatable (info))
451 		addend += sec->output_offset;
452 	      else
453 		{
454 		  asection *msec = sec;
455 		  addend = _bfd_elf_rel_local_sym (output_bfd, sym, &msec,
456 						   addend);
457 		  addend -= relocation;
458 		  addend += msec->output_section->vma + msec->output_offset;
459 		}
460 	      insert_rel_addend (input_bfd, where, howto, addend);
461 	    }
462 	}
463       else
464 	{
465 	  bfd_boolean unresolved_reloc, warned, ignored;
466 
467 	  RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
468 				   r_symndx, symtab_hdr, sym_hashes,
469 				   h, sec, relocation,
470 				   unresolved_reloc, warned, ignored);
471 	}
472 
473       if (sec != NULL && discarded_section (sec))
474 	RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
475 					 rel, 1, relend, howto, 0, contents);
476 
477       if (bfd_link_relocatable (info))
478 	continue;
479 
480       if (h != NULL)
481 	name = h->root.root.string;
482       else
483 	{
484 	  name = (bfd_elf_string_from_elf_section
485 		  (input_bfd, symtab_hdr->sh_link, sym->st_name));
486 	  if (name == NULL || *name == '\0')
487 	    name = bfd_section_name (input_bfd, sec);
488 	}
489 
490       r = _bfd_final_link_relocate (howto, input_bfd, input_section,
491                                     contents, rel->r_offset,
492                                     relocation, (bfd_vma) 0);
493 
494       if (r != bfd_reloc_ok)
495 	{
496 	  const char * msg = (const char *) 0;
497 
498 	  switch (r)
499 	    {
500 	    case bfd_reloc_overflow:
501 	      (*info->callbacks->reloc_overflow)
502 		(info, (h ? &h->root : NULL), name, howto->name,
503 		 (bfd_vma) 0, input_bfd, input_section, rel->r_offset);
504 	      break;
505 
506 	    case bfd_reloc_undefined:
507 	      (*info->callbacks->undefined_symbol)
508 		(info, name, input_bfd, input_section, rel->r_offset, TRUE);
509 	      break;
510 
511 	    case bfd_reloc_outofrange:
512 	      msg = _("internal error: out of range error");
513 	      goto common_error;
514 
515 	    case bfd_reloc_notsupported:
516 	      msg = _("internal error: unsupported relocation error");
517 	      goto common_error;
518 
519 	    case bfd_reloc_dangerous:
520 	      msg = _("internal error: dangerous error");
521 	      goto common_error;
522 
523 	    default:
524 	      msg = _("internal error: unknown error");
525 	      /* fall through */
526 
527 	    common_error:
528 	      (*info->callbacks->warning) (info, msg, name, input_bfd,
529 					   input_section, rel->r_offset);
530 	      break;
531 	    }
532 	}
533     }
534 
535   return TRUE;
536 }
537 #define ELF_ARCH		bfd_arch_d10v
538 #define ELF_MACHINE_CODE	EM_D10V
539 #define ELF_MACHINE_ALT1	EM_CYGNUS_D10V
540 #define ELF_MAXPAGESIZE		0x1000
541 
542 #define TARGET_BIG_SYM          d10v_elf32_vec
543 #define TARGET_BIG_NAME		"elf32-d10v"
544 
545 #define elf_info_to_howto	             0
546 #define elf_info_to_howto_rel	             d10v_info_to_howto_rel
547 #define elf_backend_object_p	             0
548 #define elf_backend_final_write_processing   0
549 #define elf_backend_gc_mark_hook             elf32_d10v_gc_mark_hook
550 #define elf_backend_check_relocs             elf32_d10v_check_relocs
551 #define elf_backend_relocate_section         elf32_d10v_relocate_section
552 #define elf_backend_can_gc_sections          1
553 
554 #include "elf32-target.h"
555