xref: /netbsd-src/external/gpl3/binutils/dist/bfd/elf32-moxie.c (revision 7863ba460b0a05b553c754e5dbc29247dddec322)
1 /* moxie-specific support for 32-bit ELF.
2    Copyright (C) 2009-2016 Free Software Foundation, Inc.
3 
4    Copied from elf32-fr30.c which is..
5    Copyright (C) 1998-2016 Free Software Foundation, Inc.
6 
7    This file is part of BFD, the Binary File Descriptor library.
8 
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 3 of the License, or
12    (at your option) any later version.
13 
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program; if not, write to the Free Software
21    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22    MA 02110-1301, USA.  */
23 
24 #include "sysdep.h"
25 #include "bfd.h"
26 #include "libbfd.h"
27 #include "elf-bfd.h"
28 #include "elf/moxie.h"
29 
30 /* Forward declarations.  */
31 
32 static reloc_howto_type moxie_elf_howto_table [] =
33 {
34   /* This reloc does nothing.  */
35   HOWTO (R_MOXIE_NONE,		/* type */
36 	 0,			/* rightshift */
37 	 3,			/* size (0 = byte, 1 = short, 2 = long) */
38 	 0,			/* bitsize */
39 	 FALSE,			/* pc_relative */
40 	 0,			/* bitpos */
41 	 complain_overflow_dont, /* complain_on_overflow */
42 	 bfd_elf_generic_reloc,	/* special_function */
43 	 "R_MOXIE_NONE",		/* name */
44 	 FALSE,			/* partial_inplace */
45 	 0,			/* src_mask */
46 	 0,			/* dst_mask */
47 	 FALSE),		/* pcrel_offset */
48 
49   /* A 32 bit absolute relocation.  */
50   HOWTO (R_MOXIE_32,		/* type */
51 	 0,			/* rightshift */
52 	 2,			/* size (0 = byte, 1 = short, 2 = long) */
53 	 32,			/* bitsize */
54 	 FALSE,			/* pc_relative */
55 	 0,			/* bitpos */
56 	 complain_overflow_bitfield, /* complain_on_overflow */
57 	 bfd_elf_generic_reloc,	/* special_function */
58 	 "R_MOXIE_32",		/* name */
59 	 FALSE,			/* partial_inplace */
60 	 0x00000000,		/* src_mask */
61 	 0xffffffff,		/* dst_mask */
62 	 FALSE),		/* pcrel_offset */
63 
64   /* A 10 bit PC-relative relocation.  */
65   HOWTO (R_MOXIE_PCREL10,	/* type.  */
66 	 1,			/* rightshift.  */
67 	 1,			/* size (0 = byte, 1 = short, 2 = long).  */
68 	 10,			/* bitsize.  */
69 	 TRUE,			/* pc_relative.  */
70 	 0,			/* bitpos.  */
71 	 complain_overflow_signed, /* complain_on_overflow.  */
72 	 bfd_elf_generic_reloc,	/* special_function.  */
73 	 "R_MOXIE_PCREL10",		/* name.  */
74 	 FALSE,			/* partial_inplace.  */
75 	 0,			/* src_mask.  */
76 	 0x000003FF,		/* dst_mask.  */
77 	 TRUE),			/* pcrel_offset.  */
78 };
79 
80 /* Map BFD reloc types to MOXIE ELF reloc types.  */
81 
82 struct moxie_reloc_map
83 {
84   bfd_reloc_code_real_type bfd_reloc_val;
85   unsigned int moxie_reloc_val;
86 };
87 
88 static const struct moxie_reloc_map moxie_reloc_map [] =
89 {
90   { BFD_RELOC_NONE,            R_MOXIE_NONE },
91   { BFD_RELOC_32,              R_MOXIE_32 },
92   { BFD_RELOC_MOXIE_10_PCREL,  R_MOXIE_PCREL10 },
93 };
94 
95 static reloc_howto_type *
96 moxie_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
97 			 bfd_reloc_code_real_type code)
98 {
99   unsigned int i;
100 
101   for (i = sizeof (moxie_reloc_map) / sizeof (moxie_reloc_map[0]);
102        i--;)
103     if (moxie_reloc_map [i].bfd_reloc_val == code)
104       return & moxie_elf_howto_table [moxie_reloc_map[i].moxie_reloc_val];
105 
106   return NULL;
107 }
108 
109 static reloc_howto_type *
110 moxie_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED, const char *r_name)
111 {
112   unsigned int i;
113 
114   for (i = 0;
115        i < sizeof (moxie_elf_howto_table) / sizeof (moxie_elf_howto_table[0]);
116        i++)
117     if (moxie_elf_howto_table[i].name != NULL
118 	&& strcasecmp (moxie_elf_howto_table[i].name, r_name) == 0)
119       return &moxie_elf_howto_table[i];
120 
121   return NULL;
122 }
123 
124 /* Set the howto pointer for an MOXIE ELF reloc.  */
125 
126 static void
127 moxie_info_to_howto_rela (bfd *abfd ATTRIBUTE_UNUSED,
128 			  arelent *cache_ptr,
129 			  Elf_Internal_Rela *dst)
130 {
131   unsigned int r_type;
132 
133   r_type = ELF32_R_TYPE (dst->r_info);
134   if (r_type >= (unsigned int) R_MOXIE_max)
135     {
136       _bfd_error_handler (_("%B: invalid Moxie reloc number: %d"), abfd, r_type);
137       r_type = 0;
138     }
139   cache_ptr->howto = & moxie_elf_howto_table [r_type];
140 }
141 
142 /* Perform a single relocation.  By default we use the standard BFD
143    routines, but a few relocs, we have to do them ourselves.  */
144 
145 static bfd_reloc_status_type
146 moxie_final_link_relocate (reloc_howto_type *howto,
147 			   bfd *input_bfd,
148 			   asection *input_section,
149 			   bfd_byte *contents,
150 			   Elf_Internal_Rela *rel,
151 			   bfd_vma relocation)
152 {
153   bfd_reloc_status_type r = bfd_reloc_ok;
154 
155   switch (howto->type)
156     {
157     default:
158       r = _bfd_final_link_relocate (howto, input_bfd, input_section,
159 				    contents, rel->r_offset,
160 				    relocation, rel->r_addend);
161     }
162 
163   return r;
164 }
165 
166 /* Relocate an MOXIE ELF section.
167 
168    The RELOCATE_SECTION function is called by the new ELF backend linker
169    to handle the relocations for a section.
170 
171    The relocs are always passed as Rela structures; if the section
172    actually uses Rel structures, the r_addend field will always be
173    zero.
174 
175    This function is responsible for adjusting the section contents as
176    necessary, and (if using Rela relocs and generating a relocatable
177    output file) adjusting the reloc addend as necessary.
178 
179    This function does not have to worry about setting the reloc
180    address or the reloc symbol index.
181 
182    LOCAL_SYMS is a pointer to the swapped in local symbols.
183 
184    LOCAL_SECTIONS is an array giving the section in the input file
185    corresponding to the st_shndx field of each local symbol.
186 
187    The global hash table entry for the global symbols can be found
188    via elf_sym_hashes (input_bfd).
189 
190    When generating relocatable output, this function must handle
191    STB_LOCAL/STT_SECTION symbols specially.  The output symbol is
192    going to be the section symbol corresponding to the output
193    section, which means that the addend must be adjusted
194    accordingly.  */
195 
196 static bfd_boolean
197 moxie_elf_relocate_section (bfd *output_bfd,
198 			    struct bfd_link_info *info,
199 			    bfd *input_bfd,
200 			    asection *input_section,
201 			    bfd_byte *contents,
202 			    Elf_Internal_Rela *relocs,
203 			    Elf_Internal_Sym *local_syms,
204 			    asection **local_sections)
205 {
206   Elf_Internal_Shdr *symtab_hdr;
207   struct elf_link_hash_entry **sym_hashes;
208   Elf_Internal_Rela *rel;
209   Elf_Internal_Rela *relend;
210 
211   symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
212   sym_hashes = elf_sym_hashes (input_bfd);
213   relend     = relocs + input_section->reloc_count;
214 
215   for (rel = relocs; rel < relend; rel ++)
216     {
217       reloc_howto_type *howto;
218       unsigned long r_symndx;
219       Elf_Internal_Sym *sym;
220       asection *sec;
221       struct elf_link_hash_entry *h;
222       bfd_vma relocation;
223       bfd_reloc_status_type r;
224       const char *name;
225       int r_type;
226 
227       r_type = ELF32_R_TYPE (rel->r_info);
228       r_symndx = ELF32_R_SYM (rel->r_info);
229       howto  = moxie_elf_howto_table + r_type;
230       h      = NULL;
231       sym    = NULL;
232       sec    = NULL;
233 
234       if (r_symndx < symtab_hdr->sh_info)
235 	{
236 	  sym = local_syms + r_symndx;
237 	  sec = local_sections [r_symndx];
238 	  relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
239 
240 	  name = bfd_elf_string_from_elf_section
241 	    (input_bfd, symtab_hdr->sh_link, sym->st_name);
242 	  name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;
243 	}
244       else
245 	{
246 	  bfd_boolean unresolved_reloc, warned, ignored;
247 
248 	  RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
249 				   r_symndx, symtab_hdr, sym_hashes,
250 				   h, sec, relocation,
251 				   unresolved_reloc, warned, ignored);
252 
253 	  name = h->root.root.string;
254 	}
255 
256       if (sec != NULL && discarded_section (sec))
257 	RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
258 					 rel, 1, relend, howto, 0, contents);
259 
260       if (bfd_link_relocatable (info))
261 	continue;
262 
263       r = moxie_final_link_relocate (howto, input_bfd, input_section,
264 				     contents, rel, relocation);
265 
266       if (r != bfd_reloc_ok)
267 	{
268 	  const char * msg = NULL;
269 
270 	  switch (r)
271 	    {
272 	    case bfd_reloc_overflow:
273 	      (*info->callbacks->reloc_overflow)
274 		(info, (h ? &h->root : NULL), name, howto->name,
275 		 (bfd_vma) 0, input_bfd, input_section, rel->r_offset);
276 	      break;
277 
278 	    case bfd_reloc_undefined:
279 	      (*info->callbacks->undefined_symbol)
280 		(info, name, input_bfd, input_section, rel->r_offset, TRUE);
281 	      break;
282 
283 	    case bfd_reloc_outofrange:
284 	      msg = _("internal error: out of range error");
285 	      break;
286 
287 	    case bfd_reloc_notsupported:
288 	      msg = _("internal error: unsupported relocation error");
289 	      break;
290 
291 	    case bfd_reloc_dangerous:
292 	      msg = _("internal error: dangerous relocation");
293 	      break;
294 
295 	    default:
296 	      msg = _("internal error: unknown error");
297 	      break;
298 	    }
299 
300 	  if (msg)
301 	    (*info->callbacks->warning) (info, msg, name, input_bfd,
302 					 input_section, rel->r_offset);
303 	}
304     }
305 
306   return TRUE;
307 }
308 
309 /* Return the section that should be marked against GC for a given
310    relocation.  */
311 
312 static asection *
313 moxie_elf_gc_mark_hook (asection *sec,
314 			struct bfd_link_info *info,
315 			Elf_Internal_Rela *rel,
316 			struct elf_link_hash_entry *h,
317 			Elf_Internal_Sym *sym)
318 {
319   return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
320 }
321 
322 /* Look through the relocs for a section during the first phase.
323    Since we don't do .gots or .plts, we just need to consider the
324    virtual table relocs for gc.  */
325 
326 static bfd_boolean
327 moxie_elf_check_relocs (bfd *abfd,
328 			struct bfd_link_info *info,
329 			asection *sec,
330 			const Elf_Internal_Rela *relocs)
331 {
332   Elf_Internal_Shdr *symtab_hdr;
333   struct elf_link_hash_entry **sym_hashes;
334   const Elf_Internal_Rela *rel;
335   const Elf_Internal_Rela *rel_end;
336 
337   if (bfd_link_relocatable (info))
338     return TRUE;
339 
340   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
341   sym_hashes = elf_sym_hashes (abfd);
342 
343   rel_end = relocs + sec->reloc_count;
344   for (rel = relocs; rel < rel_end; rel++)
345     {
346       struct elf_link_hash_entry *h;
347       unsigned long r_symndx;
348 
349       r_symndx = ELF32_R_SYM (rel->r_info);
350       if (r_symndx < symtab_hdr->sh_info)
351         h = NULL;
352       else
353 	{
354 	  h = sym_hashes[r_symndx - symtab_hdr->sh_info];
355 	  while (h->root.type == bfd_link_hash_indirect
356 		 || h->root.type == bfd_link_hash_warning)
357 	    h = (struct elf_link_hash_entry *) h->root.u.i.link;
358 
359 	  /* PR15323, ref flags aren't set for references in the same
360 	     object.  */
361 	  h->root.non_ir_ref = 1;
362 	}
363     }
364 
365   return TRUE;
366 }
367 
368 #define ELF_ARCH		bfd_arch_moxie
369 #define ELF_MACHINE_CODE	EM_MOXIE
370 #define ELF_MACHINE_ALT1        EM_MOXIE_OLD
371 #define ELF_MAXPAGESIZE		0x1
372 
373 #define TARGET_BIG_SYM          moxie_elf32_be_vec
374 #define TARGET_BIG_NAME		"elf32-bigmoxie"
375 #define TARGET_LITTLE_SYM       moxie_elf32_le_vec
376 #define TARGET_LITTLE_NAME	"elf32-littlemoxie"
377 
378 #define elf_info_to_howto_rel			NULL
379 #define elf_info_to_howto			moxie_info_to_howto_rela
380 #define elf_backend_relocate_section		moxie_elf_relocate_section
381 #define elf_backend_gc_mark_hook		moxie_elf_gc_mark_hook
382 #define elf_backend_check_relocs                moxie_elf_check_relocs
383 
384 #define elf_backend_can_gc_sections		1
385 #define elf_backend_rela_normal			1
386 
387 #define bfd_elf32_bfd_reloc_type_lookup		moxie_reloc_type_lookup
388 #define bfd_elf32_bfd_reloc_name_lookup		moxie_reloc_name_lookup
389 
390 #include "elf32-target.h"
391