xref: /netbsd-src/external/gpl3/binutils.old/dist/bfd/simple.c (revision e992f068c547fd6e84b3f104dc2340adcc955732)
1 /* simple.c -- BFD simple client routines
2    Copyright (C) 2002-2022 Free Software Foundation, Inc.
3    Contributed by MontaVista Software, Inc.
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 "bfdlink.h"
26 
27 static void
simple_dummy_add_to_set(struct bfd_link_info * info ATTRIBUTE_UNUSED,struct bfd_link_hash_entry * entry ATTRIBUTE_UNUSED,bfd_reloc_code_real_type reloc ATTRIBUTE_UNUSED,bfd * abfd ATTRIBUTE_UNUSED,asection * sec ATTRIBUTE_UNUSED,bfd_vma value ATTRIBUTE_UNUSED)28 simple_dummy_add_to_set (struct bfd_link_info * info ATTRIBUTE_UNUSED,
29 			 struct bfd_link_hash_entry *entry ATTRIBUTE_UNUSED,
30 			 bfd_reloc_code_real_type reloc ATTRIBUTE_UNUSED,
31 			 bfd *abfd ATTRIBUTE_UNUSED,
32 			 asection *sec ATTRIBUTE_UNUSED,
33 			 bfd_vma value ATTRIBUTE_UNUSED)
34 {
35 }
36 
37 static  void
simple_dummy_constructor(struct bfd_link_info * info ATTRIBUTE_UNUSED,bool constructor ATTRIBUTE_UNUSED,const char * name ATTRIBUTE_UNUSED,bfd * abfd ATTRIBUTE_UNUSED,asection * sec ATTRIBUTE_UNUSED,bfd_vma value ATTRIBUTE_UNUSED)38 simple_dummy_constructor (struct bfd_link_info * info ATTRIBUTE_UNUSED,
39 			  bool constructor ATTRIBUTE_UNUSED,
40 			  const char *name ATTRIBUTE_UNUSED,
41 			  bfd *abfd ATTRIBUTE_UNUSED,
42 			  asection *sec ATTRIBUTE_UNUSED,
43 			  bfd_vma value ATTRIBUTE_UNUSED)
44 {
45 }
46 
47 static void
simple_dummy_multiple_common(struct bfd_link_info * info ATTRIBUTE_UNUSED,struct bfd_link_hash_entry * entry ATTRIBUTE_UNUSED,bfd * abfd ATTRIBUTE_UNUSED,enum bfd_link_hash_type type ATTRIBUTE_UNUSED,bfd_vma size ATTRIBUTE_UNUSED)48 simple_dummy_multiple_common (struct bfd_link_info * info ATTRIBUTE_UNUSED,
49 			      struct bfd_link_hash_entry * entry ATTRIBUTE_UNUSED,
50 			      bfd * abfd ATTRIBUTE_UNUSED,
51 			      enum bfd_link_hash_type type ATTRIBUTE_UNUSED,
52 			      bfd_vma size ATTRIBUTE_UNUSED)
53 {
54 }
55 
56 static void
simple_dummy_warning(struct bfd_link_info * link_info ATTRIBUTE_UNUSED,const char * warning ATTRIBUTE_UNUSED,const char * symbol ATTRIBUTE_UNUSED,bfd * abfd ATTRIBUTE_UNUSED,asection * section ATTRIBUTE_UNUSED,bfd_vma address ATTRIBUTE_UNUSED)57 simple_dummy_warning (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,
58 		      const char *warning ATTRIBUTE_UNUSED,
59 		      const char *symbol ATTRIBUTE_UNUSED,
60 		      bfd *abfd ATTRIBUTE_UNUSED,
61 		      asection *section ATTRIBUTE_UNUSED,
62 		      bfd_vma address ATTRIBUTE_UNUSED)
63 {
64 }
65 
66 static void
simple_dummy_undefined_symbol(struct bfd_link_info * link_info ATTRIBUTE_UNUSED,const char * name ATTRIBUTE_UNUSED,bfd * abfd ATTRIBUTE_UNUSED,asection * section ATTRIBUTE_UNUSED,bfd_vma address ATTRIBUTE_UNUSED,bool fatal ATTRIBUTE_UNUSED)67 simple_dummy_undefined_symbol (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,
68 			       const char *name ATTRIBUTE_UNUSED,
69 			       bfd *abfd ATTRIBUTE_UNUSED,
70 			       asection *section ATTRIBUTE_UNUSED,
71 			       bfd_vma address ATTRIBUTE_UNUSED,
72 			       bool fatal ATTRIBUTE_UNUSED)
73 {
74 }
75 
76 static void
simple_dummy_reloc_overflow(struct bfd_link_info * link_info ATTRIBUTE_UNUSED,struct bfd_link_hash_entry * entry ATTRIBUTE_UNUSED,const char * name ATTRIBUTE_UNUSED,const char * reloc_name ATTRIBUTE_UNUSED,bfd_vma addend ATTRIBUTE_UNUSED,bfd * abfd ATTRIBUTE_UNUSED,asection * section ATTRIBUTE_UNUSED,bfd_vma address ATTRIBUTE_UNUSED)77 simple_dummy_reloc_overflow (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,
78 			     struct bfd_link_hash_entry *entry ATTRIBUTE_UNUSED,
79 			     const char *name ATTRIBUTE_UNUSED,
80 			     const char *reloc_name ATTRIBUTE_UNUSED,
81 			     bfd_vma addend ATTRIBUTE_UNUSED,
82 			     bfd *abfd ATTRIBUTE_UNUSED,
83 			     asection *section ATTRIBUTE_UNUSED,
84 			     bfd_vma address ATTRIBUTE_UNUSED)
85 {
86 }
87 
88 static void
simple_dummy_reloc_dangerous(struct bfd_link_info * link_info ATTRIBUTE_UNUSED,const char * message ATTRIBUTE_UNUSED,bfd * abfd ATTRIBUTE_UNUSED,asection * section ATTRIBUTE_UNUSED,bfd_vma address ATTRIBUTE_UNUSED)89 simple_dummy_reloc_dangerous (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,
90 			      const char *message ATTRIBUTE_UNUSED,
91 			      bfd *abfd ATTRIBUTE_UNUSED,
92 			      asection *section ATTRIBUTE_UNUSED,
93 			      bfd_vma address ATTRIBUTE_UNUSED)
94 {
95 }
96 
97 static void
simple_dummy_unattached_reloc(struct bfd_link_info * link_info ATTRIBUTE_UNUSED,const char * name ATTRIBUTE_UNUSED,bfd * abfd ATTRIBUTE_UNUSED,asection * section ATTRIBUTE_UNUSED,bfd_vma address ATTRIBUTE_UNUSED)98 simple_dummy_unattached_reloc (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,
99 			       const char *name ATTRIBUTE_UNUSED,
100 			       bfd *abfd ATTRIBUTE_UNUSED,
101 			       asection *section ATTRIBUTE_UNUSED,
102 			       bfd_vma address ATTRIBUTE_UNUSED)
103 {
104 }
105 
106 static void
simple_dummy_multiple_definition(struct bfd_link_info * link_info ATTRIBUTE_UNUSED,struct bfd_link_hash_entry * h ATTRIBUTE_UNUSED,bfd * nbfd ATTRIBUTE_UNUSED,asection * nsec ATTRIBUTE_UNUSED,bfd_vma nval ATTRIBUTE_UNUSED)107 simple_dummy_multiple_definition (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,
108 				  struct bfd_link_hash_entry *h ATTRIBUTE_UNUSED,
109 				  bfd *nbfd ATTRIBUTE_UNUSED,
110 				  asection *nsec ATTRIBUTE_UNUSED,
111 				  bfd_vma nval ATTRIBUTE_UNUSED)
112 {
113 }
114 
115 static void
simple_dummy_einfo(const char * fmt ATTRIBUTE_UNUSED,...)116 simple_dummy_einfo (const char *fmt ATTRIBUTE_UNUSED, ...)
117 {
118 }
119 
120 struct saved_output_info
121 {
122   bfd_vma offset;
123   asection *section;
124 };
125 
126 struct saved_offsets
127 {
128   unsigned int section_count;
129   struct saved_output_info *sections;
130 };
131 
132 /* The sections in ABFD may already have output sections and offsets
133    set if we are here during linking.
134 
135    DWARF-2 specifies offsets into debug sections in many cases and
136    bfd_simple_get_relocated_section_contents is called to relocate
137    debug info for a single relocatable object file.  So we want
138    offsets relative to that object file's sections, not offsets in the
139    output file.  For that reason, reset a debug section->output_offset
140    to zero.
141 
142    If not called during linking then set section->output_section to
143    point back to the input section, because output_section must not be
144    NULL when calling the relocation routines.
145 
146    Save the original output offset and section to restore later.  */
147 
148 static void
simple_save_output_info(bfd * abfd ATTRIBUTE_UNUSED,asection * section,void * ptr)149 simple_save_output_info (bfd *abfd ATTRIBUTE_UNUSED,
150 			 asection *section,
151 			 void *ptr)
152 {
153   struct saved_offsets *saved_offsets = (struct saved_offsets *) ptr;
154   struct saved_output_info *output_info;
155 
156   output_info = &saved_offsets->sections[section->index];
157   output_info->offset = section->output_offset;
158   output_info->section = section->output_section;
159   if ((section->flags & SEC_DEBUGGING) != 0
160       || section->output_section == NULL)
161     {
162       section->output_offset = 0;
163       section->output_section = section;
164     }
165 }
166 
167 static void
simple_restore_output_info(bfd * abfd ATTRIBUTE_UNUSED,asection * section,void * ptr)168 simple_restore_output_info (bfd *abfd ATTRIBUTE_UNUSED,
169 			    asection *section,
170 			    void *ptr)
171 {
172   struct saved_offsets *saved_offsets = (struct saved_offsets *) ptr;
173   struct saved_output_info *output_info;
174 
175   if (section->index >= saved_offsets->section_count)
176     return;
177 
178   output_info = &saved_offsets->sections[section->index];
179   section->output_offset = output_info->offset;
180   section->output_section = output_info->section;
181 }
182 
183 /*
184 FUNCTION
185 	bfd_simple_relocate_secton
186 
187 SYNOPSIS
188 	bfd_byte *bfd_simple_get_relocated_section_contents
189 	  (bfd *abfd, asection *sec, bfd_byte *outbuf, asymbol **symbol_table);
190 
191 DESCRIPTION
192 	Returns the relocated contents of section @var{sec}.  The symbols in
193 	@var{symbol_table} will be used, or the symbols from @var{abfd} if
194 	@var{symbol_table} is NULL.  The output offsets for debug sections will
195 	be temporarily reset to 0.  The result will be stored at @var{outbuf}
196 	or allocated with @code{bfd_malloc} if @var{outbuf} is @code{NULL}.
197 
198 	Returns @code{NULL} on a fatal error; ignores errors applying
199 	particular relocations.
200 */
201 
202 bfd_byte *
bfd_simple_get_relocated_section_contents(bfd * abfd,asection * sec,bfd_byte * outbuf,asymbol ** symbol_table)203 bfd_simple_get_relocated_section_contents (bfd *abfd,
204 					   asection *sec,
205 					   bfd_byte *outbuf,
206 					   asymbol **symbol_table)
207 {
208   struct bfd_link_info link_info;
209   struct bfd_link_order link_order;
210   struct bfd_link_callbacks callbacks;
211   bfd_byte *contents, *data;
212   int storage_needed;
213   struct saved_offsets saved_offsets;
214   bfd *link_next;
215 
216   /* Don't apply relocation on executable and shared library.  See
217      PR 4756.  */
218   if ((abfd->flags & (HAS_RELOC | EXEC_P | DYNAMIC)) != HAS_RELOC
219       || ! (sec->flags & SEC_RELOC))
220     {
221       contents = outbuf;
222       if (!bfd_get_full_section_contents (abfd, sec, &contents))
223 	return NULL;
224       return contents;
225     }
226 
227   /* In order to use bfd_get_relocated_section_contents, we need
228      to forge some data structures that it expects.  */
229 
230   /* Fill in the bare minimum number of fields for our purposes.  */
231   memset (&link_info, 0, sizeof (link_info));
232   link_info.output_bfd = abfd;
233   link_info.input_bfds = abfd;
234   link_info.input_bfds_tail = &abfd->link.next;
235 
236   link_next = abfd->link.next;
237   abfd->link.next = NULL;
238   link_info.hash = _bfd_generic_link_hash_table_create (abfd);
239   link_info.callbacks = &callbacks;
240   /* Make sure that any fields not initialised below do not
241      result in a potential indirection via a random address.  */
242   memset (&callbacks, 0, sizeof callbacks);
243   callbacks.warning = simple_dummy_warning;
244   callbacks.undefined_symbol = simple_dummy_undefined_symbol;
245   callbacks.reloc_overflow = simple_dummy_reloc_overflow;
246   callbacks.reloc_dangerous = simple_dummy_reloc_dangerous;
247   callbacks.unattached_reloc = simple_dummy_unattached_reloc;
248   callbacks.multiple_definition = simple_dummy_multiple_definition;
249   callbacks.einfo = simple_dummy_einfo;
250   callbacks.multiple_common = simple_dummy_multiple_common;
251   callbacks.constructor = simple_dummy_constructor;
252   callbacks.add_to_set = simple_dummy_add_to_set;
253 
254   memset (&link_order, 0, sizeof (link_order));
255   link_order.next = NULL;
256   link_order.type = bfd_indirect_link_order;
257   link_order.offset = 0;
258   link_order.size = sec->size;
259   link_order.u.indirect.section = sec;
260 
261   data = NULL;
262   if (outbuf == NULL)
263     {
264       bfd_size_type amt = sec->rawsize > sec->size ? sec->rawsize : sec->size;
265       data = (bfd_byte *) bfd_malloc (amt);
266       if (data == NULL)
267 	{
268 	  _bfd_generic_link_hash_table_free (abfd);
269 	  abfd->link.next = link_next;
270 	  return NULL;
271 	}
272       outbuf = data;
273     }
274 
275   saved_offsets.section_count = abfd->section_count;
276   saved_offsets.sections = malloc (sizeof (*saved_offsets.sections)
277 				   * saved_offsets.section_count);
278   if (saved_offsets.sections == NULL)
279     {
280       free (data);
281       _bfd_generic_link_hash_table_free (abfd);
282       abfd->link.next = link_next;
283       return NULL;
284     }
285   bfd_map_over_sections (abfd, simple_save_output_info, &saved_offsets);
286 
287   if (symbol_table == NULL)
288     {
289       _bfd_generic_link_add_symbols (abfd, &link_info);
290 
291       storage_needed = bfd_get_symtab_upper_bound (abfd);
292       symbol_table = (asymbol **) bfd_malloc (storage_needed);
293       bfd_canonicalize_symtab (abfd, symbol_table);
294     }
295   else
296     storage_needed = 0;
297 
298   contents = bfd_get_relocated_section_contents (abfd,
299 						 &link_info,
300 						 &link_order,
301 						 outbuf,
302 						 0,
303 						 symbol_table);
304   if (contents == NULL)
305     free (data);
306 
307   bfd_map_over_sections (abfd, simple_restore_output_info, &saved_offsets);
308   free (saved_offsets.sections);
309 
310   _bfd_generic_link_hash_table_free (abfd);
311   abfd->link.next = link_next;
312   return contents;
313 }
314