Handle array- and string-like values in no-op pretty printers
[binutils-gdb.git] / bfd / elfcode.h
1 /* ELF executable support for BFD.
2 Copyright (C) 1991-2023 Free Software Foundation, Inc.
3
4 Written by Fred Fish @ Cygnus Support, from information published
5 in "UNIX System V Release 4, Programmers Guide: ANSI C and
6 Programming Support Tools". Sufficient support for gdb.
7
8 Rewritten by Mark Eichin @ Cygnus Support, from information
9 published in "System V Application Binary Interface", chapters 4
10 and 5, as well as the various "Processor Supplement" documents
11 derived from it. Added support for assembler and other object file
12 utilities. Further work done by Ken Raeburn (Cygnus Support), Michael
13 Meissner (Open Software Foundation), and Peter Hoogenboom (University
14 of Utah) to finish and extend this.
15
16 This file is part of BFD, the Binary File Descriptor library.
17
18 This program is free software; you can redistribute it and/or modify
19 it under the terms of the GNU General Public License as published by
20 the Free Software Foundation; either version 3 of the License, or
21 (at your option) any later version.
22
23 This program is distributed in the hope that it will be useful,
24 but WITHOUT ANY WARRANTY; without even the implied warranty of
25 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
26 GNU General Public License for more details.
27
28 You should have received a copy of the GNU General Public License
29 along with this program; if not, write to the Free Software
30 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
31 MA 02110-1301, USA. */
32
33
34 /* Problems and other issues to resolve.
35
36 (1) BFD expects there to be some fixed number of "sections" in
37 the object file. I.E. there is a "section_count" variable in the
38 bfd structure which contains the number of sections. However, ELF
39 supports multiple "views" of a file. In particular, with current
40 implementations, executable files typically have two tables, a
41 program header table and a section header table, both of which
42 partition the executable.
43
44 In ELF-speak, the "linking view" of the file uses the section header
45 table to access "sections" within the file, and the "execution view"
46 uses the program header table to access "segments" within the file.
47 "Segments" typically may contain all the data from one or more
48 "sections".
49
50 Note that the section header table is optional in ELF executables,
51 but it is this information that is most useful to gdb. If the
52 section header table is missing, then gdb should probably try
53 to make do with the program header table. (FIXME)
54
55 (2) The code in this file is compiled twice, once in 32-bit mode and
56 once in 64-bit mode. More of it should be made size-independent
57 and moved into elf.c.
58
59 (3) ELF section symbols are handled rather sloppily now. This should
60 be cleaned up, and ELF section symbols reconciled with BFD section
61 symbols.
62
63 (4) We need a published spec for 64-bit ELF. We've got some stuff here
64 that we're using for SPARC V9 64-bit chips, but don't assume that
65 it's cast in stone.
66 */
67
68 #include "sysdep.h"
69 #include "bfd.h"
70 #include "libiberty.h"
71 #include "bfdlink.h"
72 #include "libbfd.h"
73 #include "elf-bfd.h"
74 #include "libiberty.h"
75
76 /* Renaming structures, typedefs, macros and functions to be size-specific. */
77 #define Elf_External_Ehdr NAME(Elf,External_Ehdr)
78 #define Elf_External_Sym NAME(Elf,External_Sym)
79 #define Elf_External_Shdr NAME(Elf,External_Shdr)
80 #define Elf_External_Phdr NAME(Elf,External_Phdr)
81 #define Elf_External_Rel NAME(Elf,External_Rel)
82 #define Elf_External_Rela NAME(Elf,External_Rela)
83 #define Elf_External_Dyn NAME(Elf,External_Dyn)
84
85 #define elf_core_file_failing_command NAME(bfd_elf,core_file_failing_command)
86 #define elf_core_file_failing_signal NAME(bfd_elf,core_file_failing_signal)
87 #define elf_core_file_matches_executable_p \
88 NAME(bfd_elf,core_file_matches_executable_p)
89 #define elf_core_file_pid NAME(bfd_elf,core_file_pid)
90 #define elf_object_p NAME(bfd_elf,object_p)
91 #define elf_core_file_p NAME(bfd_elf,core_file_p)
92 #define elf_get_symtab_upper_bound NAME(bfd_elf,get_symtab_upper_bound)
93 #define elf_get_dynamic_symtab_upper_bound \
94 NAME(bfd_elf,get_dynamic_symtab_upper_bound)
95 #define elf_swap_reloc_in NAME(bfd_elf,swap_reloc_in)
96 #define elf_swap_reloca_in NAME(bfd_elf,swap_reloca_in)
97 #define elf_swap_reloc_out NAME(bfd_elf,swap_reloc_out)
98 #define elf_swap_reloca_out NAME(bfd_elf,swap_reloca_out)
99 #define elf_swap_symbol_in NAME(bfd_elf,swap_symbol_in)
100 #define elf_swap_symbol_out NAME(bfd_elf,swap_symbol_out)
101 #define elf_swap_phdr_in NAME(bfd_elf,swap_phdr_in)
102 #define elf_swap_phdr_out NAME(bfd_elf,swap_phdr_out)
103 #define elf_swap_dyn_in NAME(bfd_elf,swap_dyn_in)
104 #define elf_swap_dyn_out NAME(bfd_elf,swap_dyn_out)
105 #define elf_get_reloc_upper_bound NAME(bfd_elf,get_reloc_upper_bound)
106 #define elf_canonicalize_reloc NAME(bfd_elf,canonicalize_reloc)
107 #define elf_slurp_symbol_table NAME(bfd_elf,slurp_symbol_table)
108 #define elf_canonicalize_symtab NAME(bfd_elf,canonicalize_symtab)
109 #define elf_canonicalize_dynamic_symtab \
110 NAME(bfd_elf,canonicalize_dynamic_symtab)
111 #define elf_get_synthetic_symtab \
112 NAME(bfd_elf,get_synthetic_symtab)
113 #define elf_make_empty_symbol NAME(bfd_elf,make_empty_symbol)
114 #define elf_get_symbol_info NAME(bfd_elf,get_symbol_info)
115 #define elf_get_lineno NAME(bfd_elf,get_lineno)
116 #define elf_set_arch_mach NAME(bfd_elf,set_arch_mach)
117 #define elf_find_nearest_line NAME(bfd_elf,find_nearest_line)
118 #define elf_sizeof_headers NAME(bfd_elf,sizeof_headers)
119 #define elf_set_section_contents NAME(bfd_elf,set_section_contents)
120 #define elf_no_info_to_howto NAME(bfd_elf,no_info_to_howto)
121 #define elf_no_info_to_howto_rel NAME(bfd_elf,no_info_to_howto_rel)
122 #define elf_find_section NAME(bfd_elf,find_section)
123 #define elf_write_shdrs_and_ehdr NAME(bfd_elf,write_shdrs_and_ehdr)
124 #define elf_write_out_phdrs NAME(bfd_elf,write_out_phdrs)
125 #define elf_checksum_contents NAME(bfd_elf,checksum_contents)
126 #define elf_write_relocs NAME(bfd_elf,write_relocs)
127 #define elf_slurp_reloc_table NAME(bfd_elf,slurp_reloc_table)
128
129 #if ARCH_SIZE == 64
130 #define ELF_R_INFO(X,Y) ELF64_R_INFO(X,Y)
131 #define ELF_R_SYM(X) ELF64_R_SYM(X)
132 #define ELF_R_TYPE(X) ELF64_R_TYPE(X)
133 #define ELFCLASS ELFCLASS64
134 #define FILE_ALIGN 8
135 #define LOG_FILE_ALIGN 3
136 #endif
137 #if ARCH_SIZE == 32
138 #define ELF_R_INFO(X,Y) ELF32_R_INFO(X,Y)
139 #define ELF_R_SYM(X) ELF32_R_SYM(X)
140 #define ELF_R_TYPE(X) ELF32_R_TYPE(X)
141 #define ELFCLASS ELFCLASS32
142 #define FILE_ALIGN 4
143 #define LOG_FILE_ALIGN 2
144 #endif
145
146 #if DEBUG & 2
147 static void elf_debug_section (int, Elf_Internal_Shdr *);
148 #endif
149 #if DEBUG & 1
150 static void elf_debug_file (Elf_Internal_Ehdr *);
151 #endif
152 \f
153 /* Structure swapping routines */
154
155 /* Should perhaps use put_offset, put_word, etc. For now, the two versions
156 can be handled by explicitly specifying 32 bits or "the long type". */
157 #if ARCH_SIZE == 64
158 #define H_PUT_WORD H_PUT_64
159 #define H_PUT_SIGNED_WORD H_PUT_S64
160 #define H_GET_WORD H_GET_64
161 #define H_GET_SIGNED_WORD H_GET_S64
162 #endif
163 #if ARCH_SIZE == 32
164 #define H_PUT_WORD H_PUT_32
165 #define H_PUT_SIGNED_WORD H_PUT_S32
166 #define H_GET_WORD H_GET_32
167 #define H_GET_SIGNED_WORD H_GET_S32
168 #endif
169
170 /* Translate an ELF symbol in external format into an ELF symbol in internal
171 format. */
172
173 bool
174 elf_swap_symbol_in (bfd *abfd,
175 const void *psrc,
176 const void *pshn,
177 Elf_Internal_Sym *dst)
178 {
179 const Elf_External_Sym *src = (const Elf_External_Sym *) psrc;
180 const Elf_External_Sym_Shndx *shndx = (const Elf_External_Sym_Shndx *) pshn;
181 int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma;
182
183 dst->st_name = H_GET_32 (abfd, src->st_name);
184 if (signed_vma)
185 dst->st_value = H_GET_SIGNED_WORD (abfd, src->st_value);
186 else
187 dst->st_value = H_GET_WORD (abfd, src->st_value);
188 dst->st_size = H_GET_WORD (abfd, src->st_size);
189 dst->st_info = H_GET_8 (abfd, src->st_info);
190 dst->st_other = H_GET_8 (abfd, src->st_other);
191 dst->st_shndx = H_GET_16 (abfd, src->st_shndx);
192 if (dst->st_shndx == (SHN_XINDEX & 0xffff))
193 {
194 if (shndx == NULL)
195 return false;
196 dst->st_shndx = H_GET_32 (abfd, shndx->est_shndx);
197 }
198 else if (dst->st_shndx >= (SHN_LORESERVE & 0xffff))
199 dst->st_shndx += SHN_LORESERVE - (SHN_LORESERVE & 0xffff);
200 dst->st_target_internal = 0;
201 return true;
202 }
203
204 /* Translate an ELF symbol in internal format into an ELF symbol in external
205 format. */
206
207 void
208 elf_swap_symbol_out (bfd *abfd,
209 const Elf_Internal_Sym *src,
210 void *cdst,
211 void *shndx)
212 {
213 unsigned int tmp;
214 Elf_External_Sym *dst = (Elf_External_Sym *) cdst;
215 H_PUT_32 (abfd, src->st_name, dst->st_name);
216 H_PUT_WORD (abfd, src->st_value, dst->st_value);
217 H_PUT_WORD (abfd, src->st_size, dst->st_size);
218 H_PUT_8 (abfd, src->st_info, dst->st_info);
219 H_PUT_8 (abfd, src->st_other, dst->st_other);
220 tmp = src->st_shndx;
221 if (tmp >= (SHN_LORESERVE & 0xffff) && tmp < SHN_LORESERVE)
222 {
223 if (shndx == NULL)
224 abort ();
225 H_PUT_32 (abfd, tmp, shndx);
226 tmp = SHN_XINDEX & 0xffff;
227 }
228 H_PUT_16 (abfd, tmp, dst->st_shndx);
229 }
230
231 /* Translate an ELF file header in external format into an ELF file header in
232 internal format. */
233
234 static void
235 elf_swap_ehdr_in (bfd *abfd,
236 const Elf_External_Ehdr *src,
237 Elf_Internal_Ehdr *dst)
238 {
239 int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma;
240 memcpy (dst->e_ident, src->e_ident, EI_NIDENT);
241 dst->e_type = H_GET_16 (abfd, src->e_type);
242 dst->e_machine = H_GET_16 (abfd, src->e_machine);
243 dst->e_version = H_GET_32 (abfd, src->e_version);
244 if (signed_vma)
245 dst->e_entry = H_GET_SIGNED_WORD (abfd, src->e_entry);
246 else
247 dst->e_entry = H_GET_WORD (abfd, src->e_entry);
248 dst->e_phoff = H_GET_WORD (abfd, src->e_phoff);
249 dst->e_shoff = H_GET_WORD (abfd, src->e_shoff);
250 dst->e_flags = H_GET_32 (abfd, src->e_flags);
251 dst->e_ehsize = H_GET_16 (abfd, src->e_ehsize);
252 dst->e_phentsize = H_GET_16 (abfd, src->e_phentsize);
253 dst->e_phnum = H_GET_16 (abfd, src->e_phnum);
254 dst->e_shentsize = H_GET_16 (abfd, src->e_shentsize);
255 dst->e_shnum = H_GET_16 (abfd, src->e_shnum);
256 dst->e_shstrndx = H_GET_16 (abfd, src->e_shstrndx);
257 }
258
259 /* Translate an ELF file header in internal format into an ELF file header in
260 external format. */
261
262 static void
263 elf_swap_ehdr_out (bfd *abfd,
264 const Elf_Internal_Ehdr *src,
265 Elf_External_Ehdr *dst)
266 {
267 unsigned int tmp;
268 int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma;
269 bool no_section_header = (abfd->flags & BFD_NO_SECTION_HEADER) != 0;
270 memcpy (dst->e_ident, src->e_ident, EI_NIDENT);
271 /* note that all elements of dst are *arrays of unsigned char* already... */
272 H_PUT_16 (abfd, src->e_type, dst->e_type);
273 H_PUT_16 (abfd, src->e_machine, dst->e_machine);
274 H_PUT_32 (abfd, src->e_version, dst->e_version);
275 if (signed_vma)
276 H_PUT_SIGNED_WORD (abfd, src->e_entry, dst->e_entry);
277 else
278 H_PUT_WORD (abfd, src->e_entry, dst->e_entry);
279 H_PUT_WORD (abfd, src->e_phoff, dst->e_phoff);
280 if (no_section_header)
281 H_PUT_WORD (abfd, 0, dst->e_shoff);
282 else
283 H_PUT_WORD (abfd, src->e_shoff, dst->e_shoff);
284 H_PUT_32 (abfd, src->e_flags, dst->e_flags);
285 H_PUT_16 (abfd, src->e_ehsize, dst->e_ehsize);
286 H_PUT_16 (abfd, src->e_phentsize, dst->e_phentsize);
287 tmp = src->e_phnum;
288 if (tmp > PN_XNUM)
289 tmp = PN_XNUM;
290 H_PUT_16 (abfd, tmp, dst->e_phnum);
291 if (no_section_header)
292 {
293 H_PUT_16 (abfd, 0, dst->e_shentsize);
294 H_PUT_16 (abfd, 0, dst->e_shnum);
295 H_PUT_16 (abfd, 0, dst->e_shstrndx);
296 }
297 else
298 {
299 H_PUT_16 (abfd, src->e_shentsize, dst->e_shentsize);
300 tmp = src->e_shnum;
301 if (tmp >= (SHN_LORESERVE & 0xffff))
302 tmp = SHN_UNDEF;
303 H_PUT_16 (abfd, tmp, dst->e_shnum);
304 tmp = src->e_shstrndx;
305 if (tmp >= (SHN_LORESERVE & 0xffff))
306 tmp = SHN_XINDEX & 0xffff;
307 H_PUT_16 (abfd, tmp, dst->e_shstrndx);
308 }
309 }
310
311 /* Translate an ELF section header table entry in external format into an
312 ELF section header table entry in internal format. */
313
314 static void
315 elf_swap_shdr_in (bfd *abfd,
316 const Elf_External_Shdr *src,
317 Elf_Internal_Shdr *dst)
318 {
319 int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma;
320
321 dst->sh_name = H_GET_32 (abfd, src->sh_name);
322 dst->sh_type = H_GET_32 (abfd, src->sh_type);
323 dst->sh_flags = H_GET_WORD (abfd, src->sh_flags);
324 if (signed_vma)
325 dst->sh_addr = H_GET_SIGNED_WORD (abfd, src->sh_addr);
326 else
327 dst->sh_addr = H_GET_WORD (abfd, src->sh_addr);
328 dst->sh_offset = H_GET_WORD (abfd, src->sh_offset);
329 dst->sh_size = H_GET_WORD (abfd, src->sh_size);
330 /* PR 23657. Check for invalid section size, in sections with contents.
331 Note - we do not set an error value here because the contents
332 of this particular section might not be needed by the consumer. */
333 if (dst->sh_type != SHT_NOBITS)
334 {
335 ufile_ptr filesize = bfd_get_file_size (abfd);
336
337 if (filesize != 0
338 && ((ufile_ptr) dst->sh_offset > filesize
339 || dst->sh_size > filesize - dst->sh_offset)
340 && !abfd->read_only)
341 {
342 _bfd_error_handler (_("warning: %pB has a section "
343 "extending past end of file"), abfd);
344 abfd->read_only = 1;
345 }
346 }
347 dst->sh_link = H_GET_32 (abfd, src->sh_link);
348 dst->sh_info = H_GET_32 (abfd, src->sh_info);
349 dst->sh_addralign = H_GET_WORD (abfd, src->sh_addralign);
350 dst->sh_entsize = H_GET_WORD (abfd, src->sh_entsize);
351 dst->bfd_section = NULL;
352 dst->contents = NULL;
353 }
354
355 /* Translate an ELF section header table entry in internal format into an
356 ELF section header table entry in external format. */
357
358 static void
359 elf_swap_shdr_out (bfd *abfd,
360 const Elf_Internal_Shdr *src,
361 Elf_External_Shdr *dst)
362 {
363 /* note that all elements of dst are *arrays of unsigned char* already... */
364 H_PUT_32 (abfd, src->sh_name, dst->sh_name);
365 H_PUT_32 (abfd, src->sh_type, dst->sh_type);
366 H_PUT_WORD (abfd, src->sh_flags, dst->sh_flags);
367 H_PUT_WORD (abfd, src->sh_addr, dst->sh_addr);
368 H_PUT_WORD (abfd, src->sh_offset, dst->sh_offset);
369 H_PUT_WORD (abfd, src->sh_size, dst->sh_size);
370 H_PUT_32 (abfd, src->sh_link, dst->sh_link);
371 H_PUT_32 (abfd, src->sh_info, dst->sh_info);
372 H_PUT_WORD (abfd, src->sh_addralign, dst->sh_addralign);
373 H_PUT_WORD (abfd, src->sh_entsize, dst->sh_entsize);
374 }
375
376 /* Translate an ELF program header table entry in external format into an
377 ELF program header table entry in internal format. */
378
379 void
380 elf_swap_phdr_in (bfd *abfd,
381 const Elf_External_Phdr *src,
382 Elf_Internal_Phdr *dst)
383 {
384 int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma;
385
386 dst->p_type = H_GET_32 (abfd, src->p_type);
387 dst->p_flags = H_GET_32 (abfd, src->p_flags);
388 dst->p_offset = H_GET_WORD (abfd, src->p_offset);
389 if (signed_vma)
390 {
391 dst->p_vaddr = H_GET_SIGNED_WORD (abfd, src->p_vaddr);
392 dst->p_paddr = H_GET_SIGNED_WORD (abfd, src->p_paddr);
393 }
394 else
395 {
396 dst->p_vaddr = H_GET_WORD (abfd, src->p_vaddr);
397 dst->p_paddr = H_GET_WORD (abfd, src->p_paddr);
398 }
399 dst->p_filesz = H_GET_WORD (abfd, src->p_filesz);
400 dst->p_memsz = H_GET_WORD (abfd, src->p_memsz);
401 dst->p_align = H_GET_WORD (abfd, src->p_align);
402 }
403
404 void
405 elf_swap_phdr_out (bfd *abfd,
406 const Elf_Internal_Phdr *src,
407 Elf_External_Phdr *dst)
408 {
409 const struct elf_backend_data *bed;
410 bfd_vma p_paddr;
411
412 bed = get_elf_backend_data (abfd);
413 p_paddr = bed->want_p_paddr_set_to_zero ? 0 : src->p_paddr;
414
415 /* note that all elements of dst are *arrays of unsigned char* already... */
416 H_PUT_32 (abfd, src->p_type, dst->p_type);
417 H_PUT_WORD (abfd, src->p_offset, dst->p_offset);
418 H_PUT_WORD (abfd, src->p_vaddr, dst->p_vaddr);
419 H_PUT_WORD (abfd, p_paddr, dst->p_paddr);
420 H_PUT_WORD (abfd, src->p_filesz, dst->p_filesz);
421 H_PUT_WORD (abfd, src->p_memsz, dst->p_memsz);
422 H_PUT_32 (abfd, src->p_flags, dst->p_flags);
423 H_PUT_WORD (abfd, src->p_align, dst->p_align);
424 }
425
426 /* Translate an ELF reloc from external format to internal format. */
427 void
428 elf_swap_reloc_in (bfd *abfd,
429 const bfd_byte *s,
430 Elf_Internal_Rela *dst)
431 {
432 const Elf_External_Rel *src = (const Elf_External_Rel *) s;
433 dst->r_offset = H_GET_WORD (abfd, src->r_offset);
434 dst->r_info = H_GET_WORD (abfd, src->r_info);
435 dst->r_addend = 0;
436 }
437
438 void
439 elf_swap_reloca_in (bfd *abfd,
440 const bfd_byte *s,
441 Elf_Internal_Rela *dst)
442 {
443 const Elf_External_Rela *src = (const Elf_External_Rela *) s;
444 dst->r_offset = H_GET_WORD (abfd, src->r_offset);
445 dst->r_info = H_GET_WORD (abfd, src->r_info);
446 dst->r_addend = H_GET_SIGNED_WORD (abfd, src->r_addend);
447 }
448
449 /* Translate an ELF reloc from internal format to external format. */
450 void
451 elf_swap_reloc_out (bfd *abfd,
452 const Elf_Internal_Rela *src,
453 bfd_byte *d)
454 {
455 Elf_External_Rel *dst = (Elf_External_Rel *) d;
456 H_PUT_WORD (abfd, src->r_offset, dst->r_offset);
457 H_PUT_WORD (abfd, src->r_info, dst->r_info);
458 }
459
460 void
461 elf_swap_reloca_out (bfd *abfd,
462 const Elf_Internal_Rela *src,
463 bfd_byte *d)
464 {
465 Elf_External_Rela *dst = (Elf_External_Rela *) d;
466 H_PUT_WORD (abfd, src->r_offset, dst->r_offset);
467 H_PUT_WORD (abfd, src->r_info, dst->r_info);
468 H_PUT_SIGNED_WORD (abfd, src->r_addend, dst->r_addend);
469 }
470
471 void
472 elf_swap_dyn_in (bfd *abfd,
473 const void *p,
474 Elf_Internal_Dyn *dst)
475 {
476 const Elf_External_Dyn *src = (const Elf_External_Dyn *) p;
477
478 dst->d_tag = H_GET_WORD (abfd, src->d_tag);
479 dst->d_un.d_val = H_GET_WORD (abfd, src->d_un.d_val);
480 }
481
482 void
483 elf_swap_dyn_out (bfd *abfd,
484 const Elf_Internal_Dyn *src,
485 void *p)
486 {
487 Elf_External_Dyn *dst = (Elf_External_Dyn *) p;
488
489 H_PUT_WORD (abfd, src->d_tag, dst->d_tag);
490 H_PUT_WORD (abfd, src->d_un.d_val, dst->d_un.d_val);
491 }
492 \f
493 /* ELF .o/exec file reading */
494
495 /* Begin processing a given object.
496
497 First we validate the file by reading in the ELF header and checking
498 the magic number. */
499
500 static inline bool
501 elf_file_p (Elf_External_Ehdr *x_ehdrp)
502 {
503 return ((x_ehdrp->e_ident[EI_MAG0] == ELFMAG0)
504 && (x_ehdrp->e_ident[EI_MAG1] == ELFMAG1)
505 && (x_ehdrp->e_ident[EI_MAG2] == ELFMAG2)
506 && (x_ehdrp->e_ident[EI_MAG3] == ELFMAG3));
507 }
508
509 /* Check to see if the file associated with ABFD matches the target vector
510 that ABFD points to.
511
512 Note that we may be called several times with the same ABFD, but different
513 target vectors, most of which will not match. We have to avoid leaving
514 any side effects in ABFD, or any data it points to (like tdata), if the
515 file does not match the target vector. */
516
517 bfd_cleanup
518 elf_object_p (bfd *abfd)
519 {
520 Elf_External_Ehdr x_ehdr; /* Elf file header, external form */
521 Elf_Internal_Ehdr *i_ehdrp; /* Elf file header, internal form */
522 Elf_External_Shdr x_shdr; /* Section header table entry, external form */
523 Elf_Internal_Shdr i_shdr;
524 Elf_Internal_Shdr *i_shdrp; /* Section header table, internal form */
525 unsigned int shindex;
526 const struct elf_backend_data *ebd;
527 asection *s;
528 const bfd_target *target;
529
530 /* Read in the ELF header in external format. */
531
532 if (bfd_read (&x_ehdr, sizeof (x_ehdr), abfd) != sizeof (x_ehdr))
533 {
534 if (bfd_get_error () != bfd_error_system_call)
535 goto got_wrong_format_error;
536 else
537 goto got_no_match;
538 }
539
540 /* Now check to see if we have a valid ELF file, and one that BFD can
541 make use of. The magic number must match, the address size ('class')
542 and byte-swapping must match our XVEC entry, and it must have a
543 section header table (FIXME: See comments re sections at top of this
544 file). */
545
546 if (! elf_file_p (&x_ehdr)
547 || x_ehdr.e_ident[EI_VERSION] != EV_CURRENT
548 || x_ehdr.e_ident[EI_CLASS] != ELFCLASS)
549 goto got_wrong_format_error;
550
551 /* Check that file's byte order matches xvec's */
552 switch (x_ehdr.e_ident[EI_DATA])
553 {
554 case ELFDATA2MSB: /* Big-endian */
555 if (! bfd_header_big_endian (abfd))
556 goto got_wrong_format_error;
557 break;
558 case ELFDATA2LSB: /* Little-endian */
559 if (! bfd_header_little_endian (abfd))
560 goto got_wrong_format_error;
561 break;
562 case ELFDATANONE: /* No data encoding specified */
563 default: /* Unknown data encoding specified */
564 goto got_wrong_format_error;
565 }
566
567 target = abfd->xvec;
568
569 /* Allocate an instance of the elf_obj_tdata structure and hook it up to
570 the tdata pointer in the bfd. */
571
572 if (! (*target->_bfd_set_format[bfd_object]) (abfd))
573 goto got_no_match;
574
575 /* Now that we know the byte order, swap in the rest of the header */
576 i_ehdrp = elf_elfheader (abfd);
577 elf_swap_ehdr_in (abfd, &x_ehdr, i_ehdrp);
578 #if DEBUG & 1
579 elf_debug_file (i_ehdrp);
580 #endif
581
582 /* Reject ET_CORE (header indicates core file, not object file) */
583 if (i_ehdrp->e_type == ET_CORE)
584 goto got_wrong_format_error;
585
586 /* If this is a relocatable file and there is no section header
587 table, then we're hosed. */
588 if (i_ehdrp->e_shoff < sizeof (x_ehdr) && i_ehdrp->e_type == ET_REL)
589 goto got_wrong_format_error;
590
591 /* As a simple sanity check, verify that what BFD thinks is the
592 size of each section header table entry actually matches the size
593 recorded in the file, but only if there are any sections. */
594 if (i_ehdrp->e_shentsize != sizeof (x_shdr) && i_ehdrp->e_shnum != 0)
595 goto got_wrong_format_error;
596
597 /* Further sanity check. */
598 if (i_ehdrp->e_shoff < sizeof (x_ehdr) && i_ehdrp->e_shnum != 0)
599 goto got_wrong_format_error;
600
601 ebd = get_elf_backend_data (abfd);
602 if (ebd->s->arch_size != ARCH_SIZE)
603 goto got_wrong_format_error;
604
605 /* Check that the ELF e_machine field matches what this particular
606 BFD format expects. */
607 if (ebd->elf_machine_code != i_ehdrp->e_machine
608 && (ebd->elf_machine_alt1 == 0
609 || i_ehdrp->e_machine != ebd->elf_machine_alt1)
610 && (ebd->elf_machine_alt2 == 0
611 || i_ehdrp->e_machine != ebd->elf_machine_alt2)
612 && ebd->elf_machine_code != EM_NONE)
613 goto got_wrong_format_error;
614
615 if (i_ehdrp->e_type == ET_EXEC)
616 abfd->flags |= EXEC_P;
617 else if (i_ehdrp->e_type == ET_DYN)
618 abfd->flags |= DYNAMIC;
619
620 if (i_ehdrp->e_phnum > 0)
621 abfd->flags |= D_PAGED;
622
623 if (! bfd_default_set_arch_mach (abfd, ebd->arch, 0))
624 {
625 /* It's OK if this fails for the generic target. */
626 if (ebd->elf_machine_code != EM_NONE)
627 goto got_no_match;
628 }
629
630 if (ebd->elf_machine_code != EM_NONE
631 && i_ehdrp->e_ident[EI_OSABI] != ebd->elf_osabi
632 && ebd->elf_osabi != ELFOSABI_NONE)
633 goto got_wrong_format_error;
634
635 if (i_ehdrp->e_shoff >= sizeof (x_ehdr))
636 {
637 file_ptr where = (file_ptr) i_ehdrp->e_shoff;
638
639 /* Seek to the section header table in the file. */
640 if (bfd_seek (abfd, where, SEEK_SET) != 0)
641 goto got_no_match;
642
643 /* Read the first section header at index 0, and convert to internal
644 form. */
645 if (bfd_read (&x_shdr, sizeof x_shdr, abfd) != sizeof (x_shdr))
646 goto got_no_match;
647 elf_swap_shdr_in (abfd, &x_shdr, &i_shdr);
648
649 /* If the section count is zero, the actual count is in the first
650 section header. */
651 if (i_ehdrp->e_shnum == SHN_UNDEF)
652 {
653 i_ehdrp->e_shnum = i_shdr.sh_size;
654 if (i_ehdrp->e_shnum >= SHN_LORESERVE
655 || i_ehdrp->e_shnum != i_shdr.sh_size
656 || i_ehdrp->e_shnum == 0)
657 goto got_wrong_format_error;
658 }
659
660 /* And similarly for the string table index. */
661 if (i_ehdrp->e_shstrndx == (SHN_XINDEX & 0xffff))
662 {
663 i_ehdrp->e_shstrndx = i_shdr.sh_link;
664 if (i_ehdrp->e_shstrndx != i_shdr.sh_link)
665 goto got_wrong_format_error;
666 }
667
668 /* And program headers. */
669 if (i_ehdrp->e_phnum == PN_XNUM && i_shdr.sh_info != 0)
670 {
671 i_ehdrp->e_phnum = i_shdr.sh_info;
672 if (i_ehdrp->e_phnum != i_shdr.sh_info)
673 goto got_wrong_format_error;
674 }
675
676 /* Sanity check that we can read all of the section headers.
677 It ought to be good enough to just read the last one. */
678 if (i_ehdrp->e_shnum != 1)
679 {
680 /* Check that we don't have a totally silly number of sections. */
681 if (i_ehdrp->e_shnum > (unsigned int) -1 / sizeof (x_shdr)
682 || i_ehdrp->e_shnum > (unsigned int) -1 / sizeof (i_shdr))
683 goto got_wrong_format_error;
684
685 where += (i_ehdrp->e_shnum - 1) * sizeof (x_shdr);
686 if ((bfd_size_type) where <= i_ehdrp->e_shoff)
687 goto got_wrong_format_error;
688
689 if (bfd_seek (abfd, where, SEEK_SET) != 0)
690 goto got_no_match;
691 if (bfd_read (&x_shdr, sizeof x_shdr, abfd) != sizeof (x_shdr))
692 goto got_no_match;
693
694 /* Back to where we were. */
695 where = i_ehdrp->e_shoff + sizeof (x_shdr);
696 if (bfd_seek (abfd, where, SEEK_SET) != 0)
697 goto got_no_match;
698 }
699 }
700
701 /* Allocate space for a copy of the section header table in
702 internal form. */
703 if (i_ehdrp->e_shnum != 0)
704 {
705 Elf_Internal_Shdr *shdrp;
706 unsigned int num_sec;
707 size_t amt;
708
709 if (_bfd_mul_overflow (i_ehdrp->e_shnum, sizeof (*i_shdrp), &amt))
710 goto got_wrong_format_error;
711 i_shdrp = (Elf_Internal_Shdr *) bfd_alloc (abfd, amt);
712 if (!i_shdrp)
713 goto got_no_match;
714 num_sec = i_ehdrp->e_shnum;
715 elf_numsections (abfd) = num_sec;
716 if (_bfd_mul_overflow (num_sec, sizeof (i_shdrp), &amt))
717 goto got_wrong_format_error;
718 elf_elfsections (abfd) = (Elf_Internal_Shdr **) bfd_alloc (abfd, amt);
719 if (!elf_elfsections (abfd))
720 goto got_no_match;
721 elf_tdata (abfd)->being_created = bfd_zalloc (abfd, num_sec);
722 if (!elf_tdata (abfd)->being_created)
723 goto got_no_match;
724
725 memcpy (i_shdrp, &i_shdr, sizeof (*i_shdrp));
726 for (shdrp = i_shdrp, shindex = 0; shindex < num_sec; shindex++)
727 elf_elfsections (abfd)[shindex] = shdrp++;
728
729 /* Read in the rest of the section header table and convert it
730 to internal form. */
731 for (shindex = 1; shindex < i_ehdrp->e_shnum; shindex++)
732 {
733 if (bfd_read (&x_shdr, sizeof x_shdr, abfd) != sizeof (x_shdr))
734 goto got_no_match;
735 elf_swap_shdr_in (abfd, &x_shdr, i_shdrp + shindex);
736
737 /* Sanity check sh_link and sh_info. */
738 if (i_shdrp[shindex].sh_link >= num_sec)
739 {
740 /* PR 10478: Accept Solaris binaries with a sh_link
741 field set to SHN_BEFORE or SHN_AFTER. */
742 switch (ebd->elf_machine_code)
743 {
744 case EM_386:
745 case EM_IAMCU:
746 case EM_X86_64:
747 case EM_OLD_SPARCV9:
748 case EM_SPARC32PLUS:
749 case EM_SPARCV9:
750 case EM_SPARC:
751 if (i_shdrp[shindex].sh_link == (SHN_LORESERVE & 0xffff) /* SHN_BEFORE */
752 || i_shdrp[shindex].sh_link == ((SHN_LORESERVE + 1) & 0xffff) /* SHN_AFTER */)
753 break;
754 /* Otherwise fall through. */
755 default:
756 goto got_wrong_format_error;
757 }
758 }
759
760 if (((i_shdrp[shindex].sh_flags & SHF_INFO_LINK)
761 || i_shdrp[shindex].sh_type == SHT_RELA
762 || i_shdrp[shindex].sh_type == SHT_REL)
763 && i_shdrp[shindex].sh_info >= num_sec)
764 goto got_wrong_format_error;
765
766 /* If the section is loaded, but not page aligned, clear
767 D_PAGED. */
768 if (i_shdrp[shindex].sh_size != 0
769 && (i_shdrp[shindex].sh_flags & SHF_ALLOC) != 0
770 && i_shdrp[shindex].sh_type != SHT_NOBITS
771 && (((i_shdrp[shindex].sh_addr - i_shdrp[shindex].sh_offset)
772 % ebd->minpagesize)
773 != 0))
774 abfd->flags &= ~D_PAGED;
775 }
776
777 if (i_ehdrp->e_shstrndx >= elf_numsections (abfd)
778 || i_shdrp[i_ehdrp->e_shstrndx].sh_type != SHT_STRTAB)
779 {
780 /* PR 2257:
781 We used to just goto got_wrong_format_error here
782 but there are binaries in existance for which this test
783 will prevent the binutils from working with them at all.
784 So we are kind, and reset the string index value to 0
785 so that at least some processing can be done. */
786 i_ehdrp->e_shstrndx = SHN_UNDEF;
787 if (!abfd->read_only)
788 {
789 _bfd_error_handler
790 (_("warning: %pB has a corrupt string table index"), abfd);
791 abfd->read_only = 1;
792 }
793 }
794 }
795 else if (i_ehdrp->e_shstrndx != SHN_UNDEF)
796 goto got_wrong_format_error;
797
798 /* Read in the program headers. */
799 if (i_ehdrp->e_phnum == 0)
800 elf_tdata (abfd)->phdr = NULL;
801 else
802 {
803 Elf_Internal_Phdr *i_phdr;
804 unsigned int i;
805 ufile_ptr filesize;
806 size_t amt;
807
808 /* Check for a corrupt input file with an impossibly large number
809 of program headers. */
810 filesize = bfd_get_file_size (abfd);
811 if (filesize != 0
812 && i_ehdrp->e_phnum > filesize / sizeof (Elf_External_Phdr))
813 goto got_wrong_format_error;
814 if (_bfd_mul_overflow (i_ehdrp->e_phnum, sizeof (*i_phdr), &amt))
815 goto got_wrong_format_error;
816 elf_tdata (abfd)->phdr
817 = (Elf_Internal_Phdr *) bfd_alloc (abfd, amt);
818 if (elf_tdata (abfd)->phdr == NULL)
819 goto got_no_match;
820 if (bfd_seek (abfd, i_ehdrp->e_phoff, SEEK_SET) != 0)
821 goto got_no_match;
822 bool eu_strip_broken_phdrs = false;
823 i_phdr = elf_tdata (abfd)->phdr;
824 for (i = 0; i < i_ehdrp->e_phnum; i++, i_phdr++)
825 {
826 Elf_External_Phdr x_phdr;
827
828 if (bfd_read (&x_phdr, sizeof x_phdr, abfd) != sizeof x_phdr)
829 goto got_no_match;
830 elf_swap_phdr_in (abfd, &x_phdr, i_phdr);
831 /* Too much code in BFD relies on alignment being a power of
832 two, as required by the ELF spec. */
833 if (i_phdr->p_align != (i_phdr->p_align & -i_phdr->p_align))
834 {
835 i_phdr->p_align &= -i_phdr->p_align;
836 if (!abfd->read_only)
837 {
838 _bfd_error_handler (_("warning: %pB has a program header "
839 "with invalid alignment"), abfd);
840 abfd->read_only = 1;
841 }
842 }
843 /* Detect eu-strip -f debug files, which have program
844 headers that describe the original file. */
845 if (i_phdr->p_filesz != 0
846 && (i_phdr->p_filesz > filesize
847 || i_phdr->p_offset > filesize - i_phdr->p_filesz))
848 eu_strip_broken_phdrs = true;
849 }
850 if (!eu_strip_broken_phdrs
851 && i_ehdrp->e_shoff == 0
852 && i_ehdrp->e_shstrndx == 0)
853 {
854 /* Try to reconstruct dynamic symbol table from PT_DYNAMIC
855 segment if there is no section header. */
856 i_phdr = elf_tdata (abfd)->phdr;
857 for (i = 0; i < i_ehdrp->e_phnum; i++, i_phdr++)
858 if (i_phdr->p_type == PT_DYNAMIC)
859 {
860 if (i_phdr->p_filesz != 0
861 && !_bfd_elf_get_dynamic_symbols (abfd, i_phdr,
862 elf_tdata (abfd)->phdr,
863 i_ehdrp->e_phnum,
864 filesize))
865 goto got_no_match;
866 break;
867 }
868 }
869 }
870
871 if (i_ehdrp->e_shstrndx != 0 && i_ehdrp->e_shoff >= sizeof (x_ehdr))
872 {
873 unsigned int num_sec;
874
875 /* Once all of the section headers have been read and converted, we
876 can start processing them. Note that the first section header is
877 a dummy placeholder entry, so we ignore it. */
878 num_sec = elf_numsections (abfd);
879 for (shindex = 1; shindex < num_sec; shindex++)
880 if (!bfd_section_from_shdr (abfd, shindex))
881 goto got_no_match;
882
883 /* Set up ELF sections for SHF_GROUP and SHF_LINK_ORDER. */
884 if (! _bfd_elf_setup_sections (abfd))
885 goto got_wrong_format_error;
886 }
887
888 /* Let the backend double check the format and override global
889 information. */
890 if (ebd->elf_backend_object_p)
891 {
892 if (! (*ebd->elf_backend_object_p) (abfd))
893 goto got_wrong_format_error;
894 }
895
896 /* Remember the entry point specified in the ELF file header. */
897 bfd_set_start_address (abfd, i_ehdrp->e_entry);
898
899 /* If we have created any reloc sections that are associated with
900 debugging sections, mark the reloc sections as debugging as well. */
901 for (s = abfd->sections; s != NULL; s = s->next)
902 {
903 if ((elf_section_data (s)->this_hdr.sh_type == SHT_REL
904 || elf_section_data (s)->this_hdr.sh_type == SHT_RELA)
905 && elf_section_data (s)->this_hdr.sh_info > 0)
906 {
907 unsigned long targ_index;
908 asection *targ_sec;
909
910 targ_index = elf_section_data (s)->this_hdr.sh_info;
911 targ_sec = bfd_section_from_elf_index (abfd, targ_index);
912 if (targ_sec != NULL
913 && (targ_sec->flags & SEC_DEBUGGING) != 0)
914 s->flags |= SEC_DEBUGGING;
915 }
916 }
917 return _bfd_no_cleanup;
918
919 got_wrong_format_error:
920 bfd_set_error (bfd_error_wrong_format);
921
922 got_no_match:
923 return NULL;
924 }
925 \f
926 /* ELF .o/exec file writing */
927
928 /* Write out the relocs. */
929
930 void
931 elf_write_relocs (bfd *abfd, asection *sec, void *data)
932 {
933 const struct elf_backend_data * const bed = get_elf_backend_data (abfd);
934 bool *failedp = (bool *) data;
935 Elf_Internal_Shdr *rela_hdr;
936 bfd_vma addr_offset;
937 void (*swap_out) (bfd *, const Elf_Internal_Rela *, bfd_byte *);
938 size_t extsize;
939 bfd_byte *dst_rela;
940 unsigned int idx;
941 asymbol *last_sym;
942 int last_sym_idx;
943 size_t amt;
944
945 /* If we have already failed, don't do anything. */
946 if (*failedp)
947 return;
948
949 if ((sec->flags & SEC_RELOC) == 0)
950 return;
951
952 /* The linker backend writes the relocs out itself, and sets the
953 reloc_count field to zero to inhibit writing them here. Also,
954 sometimes the SEC_RELOC flag gets set even when there aren't any
955 relocs. */
956 if (sec->reloc_count == 0)
957 return;
958
959 /* If we have opened an existing file for update, reloc_count may be
960 set even though we are not linking. In that case we have nothing
961 to do. */
962 if (sec->orelocation == NULL)
963 return;
964
965 rela_hdr = elf_section_data (sec)->rela.hdr;
966 if (rela_hdr == NULL)
967 rela_hdr = elf_section_data (sec)->rel.hdr;
968
969 rela_hdr->sh_size = rela_hdr->sh_entsize * sec->reloc_count;
970 if (_bfd_mul_overflow (sec->reloc_count, rela_hdr->sh_entsize, &amt)
971 || (rela_hdr->contents = bfd_alloc (abfd, amt)) == NULL)
972 {
973 bfd_set_error (bfd_error_no_memory);
974 *failedp = true;
975 return;
976 }
977
978 /* Figure out whether the relocations are RELA or REL relocations. */
979 if (rela_hdr->sh_type == SHT_RELA)
980 {
981 swap_out = elf_swap_reloca_out;
982 extsize = sizeof (Elf_External_Rela);
983 }
984 else if (rela_hdr->sh_type == SHT_REL)
985 {
986 swap_out = elf_swap_reloc_out;
987 extsize = sizeof (Elf_External_Rel);
988 }
989 else
990 /* Every relocation section should be either an SHT_RELA or an
991 SHT_REL section. */
992 abort ();
993
994 /* The address of an ELF reloc is section relative for an object
995 file, and absolute for an executable file or shared library.
996 The address of a BFD reloc is always section relative. */
997 addr_offset = 0;
998 if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
999 addr_offset = sec->vma;
1000
1001 /* orelocation has the data, reloc_count has the count... */
1002 last_sym = 0;
1003 last_sym_idx = 0;
1004 dst_rela = rela_hdr->contents;
1005
1006 for (idx = 0; idx < sec->reloc_count; idx++, dst_rela += extsize)
1007 {
1008 Elf_Internal_Rela src_rela;
1009 arelent *ptr;
1010 asymbol *sym;
1011 int n;
1012
1013 ptr = sec->orelocation[idx];
1014 sym = *ptr->sym_ptr_ptr;
1015 if (sym == last_sym)
1016 n = last_sym_idx;
1017 else if (bfd_is_abs_section (sym->section) && sym->value == 0)
1018 n = STN_UNDEF;
1019 else
1020 {
1021 last_sym = sym;
1022 n = _bfd_elf_symbol_from_bfd_symbol (abfd, &sym);
1023 if (n < 0)
1024 {
1025 *failedp = true;
1026 return;
1027 }
1028 last_sym_idx = n;
1029 }
1030
1031 if ((*ptr->sym_ptr_ptr)->the_bfd != NULL
1032 && (*ptr->sym_ptr_ptr)->the_bfd->xvec != abfd->xvec
1033 && ! _bfd_elf_validate_reloc (abfd, ptr))
1034 {
1035 *failedp = true;
1036 return;
1037 }
1038
1039 if (ptr->howto == NULL)
1040 {
1041 *failedp = true;
1042 return;
1043 }
1044
1045 #if defined(BFD64) && ARCH_SIZE == 32
1046 if (rela_hdr->sh_type == SHT_RELA
1047 && ptr->howto->bitsize > 32
1048 && ptr->addend - INT32_MIN > UINT32_MAX)
1049 {
1050 _bfd_error_handler (_("%pB: %pA+%" PRIx64 ": "
1051 "relocation addend %" PRIx64 " too large"),
1052 abfd, sec, (uint64_t) ptr->address,
1053 (uint64_t) ptr->addend);
1054 *failedp = true;
1055 bfd_set_error (bfd_error_bad_value);
1056 }
1057 #endif
1058
1059 src_rela.r_offset = ptr->address + addr_offset;
1060 src_rela.r_info = ELF_R_INFO (n, ptr->howto->type);
1061 src_rela.r_addend = ptr->addend;
1062 (*swap_out) (abfd, &src_rela, dst_rela);
1063 }
1064
1065 if (elf_section_data (sec)->has_secondary_relocs
1066 && !bed->write_secondary_relocs (abfd, sec))
1067 {
1068 *failedp = true;
1069 return;
1070 }
1071 }
1072
1073 /* Write out the program headers. */
1074
1075 int
1076 elf_write_out_phdrs (bfd *abfd,
1077 const Elf_Internal_Phdr *phdr,
1078 unsigned int count)
1079 {
1080 while (count--)
1081 {
1082 Elf_External_Phdr extphdr;
1083
1084 elf_swap_phdr_out (abfd, phdr, &extphdr);
1085 if (bfd_write (&extphdr, sizeof (Elf_External_Phdr), abfd)
1086 != sizeof (Elf_External_Phdr))
1087 return -1;
1088 phdr++;
1089 }
1090 return 0;
1091 }
1092
1093 /* Write out the section headers and the ELF file header. */
1094
1095 bool
1096 elf_write_shdrs_and_ehdr (bfd *abfd)
1097 {
1098 Elf_External_Ehdr x_ehdr; /* Elf file header, external form */
1099 Elf_Internal_Ehdr *i_ehdrp; /* Elf file header, internal form */
1100 Elf_External_Shdr *x_shdrp; /* Section header table, external form */
1101 Elf_Internal_Shdr **i_shdrp; /* Section header table, internal form */
1102 unsigned int count;
1103 size_t amt;
1104
1105 i_ehdrp = elf_elfheader (abfd);
1106 i_shdrp = elf_elfsections (abfd);
1107
1108 /* swap the header before spitting it out... */
1109
1110 #if DEBUG & 1
1111 elf_debug_file (i_ehdrp);
1112 #endif
1113 elf_swap_ehdr_out (abfd, i_ehdrp, &x_ehdr);
1114 amt = sizeof (x_ehdr);
1115 if (bfd_seek (abfd, 0, SEEK_SET) != 0
1116 || bfd_write (&x_ehdr, amt, abfd) != amt)
1117 return false;
1118
1119 if ((abfd->flags & BFD_NO_SECTION_HEADER) != 0)
1120 return true;
1121
1122 /* Some fields in the first section header handle overflow of ehdr
1123 fields. */
1124 if (i_ehdrp->e_phnum >= PN_XNUM)
1125 i_shdrp[0]->sh_info = i_ehdrp->e_phnum;
1126 if (i_ehdrp->e_shnum >= (SHN_LORESERVE & 0xffff))
1127 i_shdrp[0]->sh_size = i_ehdrp->e_shnum;
1128 if (i_ehdrp->e_shstrndx >= (SHN_LORESERVE & 0xffff))
1129 i_shdrp[0]->sh_link = i_ehdrp->e_shstrndx;
1130
1131 /* at this point we've concocted all the ELF sections... */
1132 if (_bfd_mul_overflow (i_ehdrp->e_shnum, sizeof (*x_shdrp), &amt))
1133 {
1134 bfd_set_error (bfd_error_no_memory);
1135 return false;
1136 }
1137 x_shdrp = (Elf_External_Shdr *) bfd_alloc (abfd, amt);
1138 if (!x_shdrp)
1139 return false;
1140
1141 for (count = 0; count < i_ehdrp->e_shnum; i_shdrp++, count++)
1142 {
1143 #if DEBUG & 2
1144 elf_debug_section (count, *i_shdrp);
1145 #endif
1146 elf_swap_shdr_out (abfd, *i_shdrp, x_shdrp + count);
1147 }
1148 amt = (bfd_size_type) i_ehdrp->e_shnum * sizeof (*x_shdrp);
1149 if (bfd_seek (abfd, i_ehdrp->e_shoff, SEEK_SET) != 0
1150 || bfd_write (x_shdrp, amt, abfd) != amt)
1151 return false;
1152
1153 /* need to dump the string table too... */
1154
1155 return true;
1156 }
1157
1158 bool
1159 elf_checksum_contents (bfd *abfd,
1160 void (*process) (const void *, size_t, void *),
1161 void *arg)
1162 {
1163 Elf_Internal_Ehdr *i_ehdrp = elf_elfheader (abfd);
1164 Elf_Internal_Shdr **i_shdrp = elf_elfsections (abfd);
1165 Elf_Internal_Phdr *i_phdrp = elf_tdata (abfd)->phdr;
1166 unsigned int count, num;
1167
1168 {
1169 Elf_External_Ehdr x_ehdr;
1170 Elf_Internal_Ehdr i_ehdr;
1171
1172 i_ehdr = *i_ehdrp;
1173 i_ehdr.e_phoff = i_ehdr.e_shoff = 0;
1174 elf_swap_ehdr_out (abfd, &i_ehdr, &x_ehdr);
1175 (*process) (&x_ehdr, sizeof x_ehdr, arg);
1176 }
1177
1178 num = i_ehdrp->e_phnum;
1179 for (count = 0; count < num; count++)
1180 {
1181 Elf_External_Phdr x_phdr;
1182 elf_swap_phdr_out (abfd, &i_phdrp[count], &x_phdr);
1183 (*process) (&x_phdr, sizeof x_phdr, arg);
1184 }
1185
1186 num = elf_numsections (abfd);
1187 for (count = 0; count < num; count++)
1188 {
1189 Elf_Internal_Shdr i_shdr;
1190 Elf_External_Shdr x_shdr;
1191 bfd_byte *contents, *free_contents;
1192
1193 i_shdr = *i_shdrp[count];
1194 i_shdr.sh_offset = 0;
1195
1196 elf_swap_shdr_out (abfd, &i_shdr, &x_shdr);
1197 (*process) (&x_shdr, sizeof x_shdr, arg);
1198
1199 /* Process the section's contents, if it has some.
1200 PR ld/12451: Read them in if necessary. */
1201 if (i_shdr.sh_type == SHT_NOBITS)
1202 continue;
1203 free_contents = NULL;
1204 contents = i_shdr.contents;
1205 if (contents == NULL)
1206 {
1207 asection *sec;
1208
1209 sec = bfd_section_from_elf_index (abfd, count);
1210 if (sec != NULL)
1211 {
1212 contents = sec->contents;
1213 if (contents == NULL)
1214 {
1215 /* Force rereading from file. */
1216 sec->flags &= ~SEC_IN_MEMORY;
1217 if (!bfd_malloc_and_get_section (abfd, sec, &free_contents))
1218 continue;
1219 contents = free_contents;
1220 }
1221 }
1222 }
1223 if (contents != NULL)
1224 {
1225 (*process) (contents, i_shdr.sh_size, arg);
1226 free (free_contents);
1227 }
1228 }
1229
1230 return true;
1231 }
1232
1233 long
1234 elf_slurp_symbol_table (bfd *abfd, asymbol **symptrs, bool dynamic)
1235 {
1236 Elf_Internal_Shdr *hdr;
1237 Elf_Internal_Shdr *verhdr;
1238 unsigned long symcount; /* Number of external ELF symbols */
1239 elf_symbol_type *sym; /* Pointer to current bfd symbol */
1240 elf_symbol_type *symbase; /* Buffer for generated bfd symbols */
1241 Elf_Internal_Sym *isym;
1242 Elf_Internal_Sym *isymend;
1243 Elf_Internal_Sym *isymbuf = NULL;
1244 Elf_External_Versym *xver;
1245 Elf_External_Versym *xverbuf = NULL;
1246 const struct elf_backend_data *ebd;
1247 size_t amt;
1248
1249 /* Read each raw ELF symbol, converting from external ELF form to
1250 internal ELF form, and then using the information to create a
1251 canonical bfd symbol table entry.
1252
1253 Note that we allocate the initial bfd canonical symbol buffer
1254 based on a one-to-one mapping of the ELF symbols to canonical
1255 symbols. We actually use all the ELF symbols, so there will be no
1256 space left over at the end. When we have all the symbols, we
1257 build the caller's pointer vector. */
1258
1259 if (! dynamic)
1260 {
1261 hdr = &elf_tdata (abfd)->symtab_hdr;
1262 verhdr = NULL;
1263 }
1264 else
1265 {
1266 hdr = &elf_tdata (abfd)->dynsymtab_hdr;
1267 if (elf_dynversym (abfd) == 0)
1268 verhdr = NULL;
1269 else
1270 verhdr = &elf_tdata (abfd)->dynversym_hdr;
1271 if ((elf_dynverdef (abfd) != 0
1272 && elf_tdata (abfd)->verdef == NULL)
1273 || (elf_dynverref (abfd) != 0
1274 && elf_tdata (abfd)->verref == NULL)
1275 || elf_tdata (abfd)->dt_verdef != NULL
1276 || elf_tdata (abfd)->dt_verneed != NULL)
1277 {
1278 if (!_bfd_elf_slurp_version_tables (abfd, false))
1279 return -1;
1280 }
1281 }
1282
1283 ebd = get_elf_backend_data (abfd);
1284 symcount = elf_tdata (abfd)->dt_symtab_count;
1285 if (symcount == 0)
1286 symcount = hdr->sh_size / sizeof (Elf_External_Sym);
1287 if (symcount == 0)
1288 sym = symbase = NULL;
1289 else
1290 {
1291 size_t i;
1292
1293 isymbuf = bfd_elf_get_elf_syms (abfd, hdr, symcount, 0,
1294 NULL, NULL, NULL);
1295 if (isymbuf == NULL)
1296 return -1;
1297
1298 if (_bfd_mul_overflow (symcount, sizeof (elf_symbol_type), &amt))
1299 {
1300 bfd_set_error (bfd_error_file_too_big);
1301 goto error_return;
1302 }
1303 symbase = (elf_symbol_type *) bfd_zalloc (abfd, amt);
1304 if (symbase == (elf_symbol_type *) NULL)
1305 goto error_return;
1306
1307 /* Read the raw ELF version symbol information. */
1308 if (verhdr != NULL
1309 && verhdr->sh_size / sizeof (Elf_External_Versym) != symcount)
1310 {
1311 _bfd_error_handler
1312 /* xgettext:c-format */
1313 (_("%pB: version count (%" PRId64 ")"
1314 " does not match symbol count (%ld)"),
1315 abfd,
1316 (int64_t) (verhdr->sh_size / sizeof (Elf_External_Versym)),
1317 symcount);
1318
1319 /* Slurp in the symbols without the version information,
1320 since that is more helpful than just quitting. */
1321 verhdr = NULL;
1322 }
1323
1324 if (verhdr != NULL)
1325 {
1326 if (bfd_seek (abfd, verhdr->sh_offset, SEEK_SET) != 0)
1327 goto error_return;
1328 xverbuf = (Elf_External_Versym *)
1329 _bfd_malloc_and_read (abfd, verhdr->sh_size, verhdr->sh_size);
1330 if (xverbuf == NULL && verhdr->sh_size != 0)
1331 goto error_return;
1332 }
1333
1334 /* Skip first symbol, which is a null dummy. */
1335 xver = xverbuf;
1336 if (xver != NULL)
1337 ++xver;
1338 isymend = isymbuf + symcount;
1339 for (isym = isymbuf + 1, sym = symbase, i = 1;
1340 isym < isymend;
1341 isym++, sym++, i++)
1342 {
1343 memcpy (&sym->internal_elf_sym, isym, sizeof (Elf_Internal_Sym));
1344
1345 sym->symbol.the_bfd = abfd;
1346 if (elf_use_dt_symtab_p (abfd))
1347 sym->symbol.name = (elf_tdata (abfd)->dt_strtab
1348 + isym->st_name);
1349 else
1350 sym->symbol.name = bfd_elf_sym_name (abfd, hdr, isym, NULL);
1351 sym->symbol.value = isym->st_value;
1352
1353 if (isym->st_shndx == SHN_UNDEF)
1354 {
1355 sym->symbol.section = bfd_und_section_ptr;
1356 }
1357 else if (isym->st_shndx == SHN_ABS)
1358 {
1359 sym->symbol.section = bfd_abs_section_ptr;
1360 }
1361 else if (isym->st_shndx == SHN_COMMON)
1362 {
1363 sym->symbol.section = bfd_com_section_ptr;
1364 if ((abfd->flags & BFD_PLUGIN) != 0)
1365 {
1366 asection *xc = bfd_get_section_by_name (abfd, "COMMON");
1367
1368 if (xc == NULL)
1369 {
1370 flagword flags = (SEC_ALLOC | SEC_IS_COMMON | SEC_KEEP
1371 | SEC_EXCLUDE);
1372 xc = bfd_make_section_with_flags (abfd, "COMMON", flags);
1373 if (xc == NULL)
1374 goto error_return;
1375 }
1376 sym->symbol.section = xc;
1377 }
1378 /* Elf puts the alignment into the `value' field, and
1379 the size into the `size' field. BFD wants to see the
1380 size in the value field, and doesn't care (at the
1381 moment) about the alignment. */
1382 sym->symbol.value = isym->st_size;
1383 }
1384 else if (elf_use_dt_symtab_p (abfd))
1385 {
1386 asection *sec;
1387 sec = _bfd_elf_get_section_from_dynamic_symbol (abfd,
1388 isym);
1389 if (sec == NULL)
1390 goto error_return;
1391 sym->symbol.section = sec;
1392 }
1393 else
1394 {
1395 sym->symbol.section
1396 = bfd_section_from_elf_index (abfd, isym->st_shndx);
1397 if (sym->symbol.section == NULL)
1398 {
1399 /* This symbol is in a section for which we did not
1400 create a BFD section. Just use bfd_abs_section,
1401 although it is wrong. FIXME. Note - there is
1402 code in elf.c:swap_out_syms that calls
1403 symbol_section_index() in the elf backend for
1404 cases like this. */
1405 sym->symbol.section = bfd_abs_section_ptr;
1406 }
1407 }
1408
1409 /* If this is a relocatable file, then the symbol value is
1410 already section relative. */
1411 if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
1412 sym->symbol.value -= sym->symbol.section->vma;
1413
1414 switch (ELF_ST_BIND (isym->st_info))
1415 {
1416 case STB_LOCAL:
1417 sym->symbol.flags |= BSF_LOCAL;
1418 break;
1419 case STB_GLOBAL:
1420 if (isym->st_shndx != SHN_UNDEF && isym->st_shndx != SHN_COMMON)
1421 sym->symbol.flags |= BSF_GLOBAL;
1422 break;
1423 case STB_WEAK:
1424 sym->symbol.flags |= BSF_WEAK;
1425 break;
1426 case STB_GNU_UNIQUE:
1427 sym->symbol.flags |= BSF_GNU_UNIQUE;
1428 break;
1429 }
1430
1431 switch (ELF_ST_TYPE (isym->st_info))
1432 {
1433 case STT_SECTION:
1434 /* Mark the input section symbol as used since it may be
1435 used for relocation and section group.
1436 NB: BSF_SECTION_SYM_USED is ignored by linker and may
1437 be cleared by objcopy for non-relocatable inputs. */
1438 sym->symbol.flags |= (BSF_SECTION_SYM
1439 | BSF_DEBUGGING
1440 | BSF_SECTION_SYM_USED);
1441 break;
1442 case STT_FILE:
1443 sym->symbol.flags |= BSF_FILE | BSF_DEBUGGING;
1444 break;
1445 case STT_FUNC:
1446 sym->symbol.flags |= BSF_FUNCTION;
1447 break;
1448 case STT_COMMON:
1449 /* FIXME: Do we have to put the size field into the value field
1450 as we do with symbols in SHN_COMMON sections (see above) ? */
1451 sym->symbol.flags |= BSF_ELF_COMMON;
1452 /* Fall through. */
1453 case STT_OBJECT:
1454 sym->symbol.flags |= BSF_OBJECT;
1455 break;
1456 case STT_TLS:
1457 sym->symbol.flags |= BSF_THREAD_LOCAL;
1458 break;
1459 case STT_RELC:
1460 sym->symbol.flags |= BSF_RELC;
1461 break;
1462 case STT_SRELC:
1463 sym->symbol.flags |= BSF_SRELC;
1464 break;
1465 case STT_GNU_IFUNC:
1466 sym->symbol.flags |= BSF_GNU_INDIRECT_FUNCTION;
1467 break;
1468 }
1469
1470 if (dynamic)
1471 sym->symbol.flags |= BSF_DYNAMIC;
1472
1473 if (elf_tdata (abfd)->dt_versym)
1474 sym->version = bfd_get_16 (abfd,
1475 elf_tdata (abfd)->dt_versym + 2 * i);
1476 else if (xver != NULL)
1477 {
1478 Elf_Internal_Versym iversym;
1479
1480 _bfd_elf_swap_versym_in (abfd, xver, &iversym);
1481 sym->version = iversym.vs_vers;
1482 xver++;
1483 }
1484
1485 /* Do some backend-specific processing on this symbol. */
1486 if (ebd->elf_backend_symbol_processing)
1487 (*ebd->elf_backend_symbol_processing) (abfd, &sym->symbol);
1488 }
1489 }
1490
1491 /* Do some backend-specific processing on this symbol table. */
1492 if (ebd->elf_backend_symbol_table_processing)
1493 (*ebd->elf_backend_symbol_table_processing) (abfd, symbase, symcount);
1494
1495 /* We rely on the zalloc to clear out the final symbol entry. */
1496
1497 symcount = sym - symbase;
1498
1499 /* Fill in the user's symbol pointer vector if needed. */
1500 if (symptrs)
1501 {
1502 long l = symcount;
1503
1504 sym = symbase;
1505 while (l-- > 0)
1506 {
1507 *symptrs++ = &sym->symbol;
1508 sym++;
1509 }
1510 *symptrs = 0; /* Final null pointer */
1511 }
1512
1513 free (xverbuf);
1514 if (hdr->contents != (unsigned char *) isymbuf
1515 && !elf_use_dt_symtab_p (abfd))
1516 free (isymbuf);
1517 return symcount;
1518
1519 error_return:
1520 free (xverbuf);
1521 if (hdr->contents != (unsigned char *) isymbuf
1522 && !elf_use_dt_symtab_p (abfd))
1523 free (isymbuf);
1524 return -1;
1525 }
1526
1527 /* Read relocations for ASECT from REL_HDR. There are RELOC_COUNT of
1528 them. */
1529
1530 static bool
1531 elf_slurp_reloc_table_from_section (bfd *abfd,
1532 asection *asect,
1533 Elf_Internal_Shdr *rel_hdr,
1534 bfd_size_type reloc_count,
1535 arelent *relents,
1536 asymbol **symbols,
1537 bool dynamic)
1538 {
1539 const struct elf_backend_data * const ebd = get_elf_backend_data (abfd);
1540 void *allocated = NULL;
1541 bfd_byte *native_relocs;
1542 arelent *relent;
1543 unsigned int i;
1544 int entsize;
1545 unsigned int symcount;
1546
1547 if (bfd_seek (abfd, rel_hdr->sh_offset, SEEK_SET) != 0)
1548 return false;
1549 allocated = _bfd_malloc_and_read (abfd, rel_hdr->sh_size, rel_hdr->sh_size);
1550 if (allocated == NULL)
1551 return false;
1552
1553 native_relocs = (bfd_byte *) allocated;
1554
1555 entsize = rel_hdr->sh_entsize;
1556 BFD_ASSERT (entsize == sizeof (Elf_External_Rel)
1557 || entsize == sizeof (Elf_External_Rela));
1558
1559 if (dynamic)
1560 symcount = bfd_get_dynamic_symcount (abfd);
1561 else
1562 symcount = bfd_get_symcount (abfd);
1563
1564 for (i = 0, relent = relents;
1565 i < reloc_count;
1566 i++, relent++, native_relocs += entsize)
1567 {
1568 bool res;
1569 Elf_Internal_Rela rela;
1570
1571 if (entsize == sizeof (Elf_External_Rela))
1572 elf_swap_reloca_in (abfd, native_relocs, &rela);
1573 else
1574 elf_swap_reloc_in (abfd, native_relocs, &rela);
1575
1576 /* The address of an ELF reloc is section relative for an object
1577 file, and absolute for an executable file or shared library.
1578 The address of a normal BFD reloc is always section relative,
1579 and the address of a dynamic reloc is absolute.. */
1580 if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0 || dynamic)
1581 relent->address = rela.r_offset;
1582 else
1583 relent->address = rela.r_offset - asect->vma;
1584
1585 if (ELF_R_SYM (rela.r_info) == STN_UNDEF)
1586 /* FIXME: This and the error case below mean that we have a
1587 symbol on relocs that is not elf_symbol_type. */
1588 relent->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;
1589 else if (ELF_R_SYM (rela.r_info) > symcount)
1590 {
1591 _bfd_error_handler
1592 /* xgettext:c-format */
1593 (_("%pB(%pA): relocation %d has invalid symbol index %ld"),
1594 abfd, asect, i, (long) ELF_R_SYM (rela.r_info));
1595 bfd_set_error (bfd_error_bad_value);
1596 relent->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;
1597 }
1598 else
1599 {
1600 asymbol **ps;
1601
1602 ps = symbols + ELF_R_SYM (rela.r_info) - 1;
1603
1604 relent->sym_ptr_ptr = ps;
1605 }
1606
1607 relent->addend = rela.r_addend;
1608
1609 if ((entsize == sizeof (Elf_External_Rela)
1610 && ebd->elf_info_to_howto != NULL)
1611 || ebd->elf_info_to_howto_rel == NULL)
1612 res = ebd->elf_info_to_howto (abfd, relent, &rela);
1613 else
1614 res = ebd->elf_info_to_howto_rel (abfd, relent, &rela);
1615
1616 if (! res || relent->howto == NULL)
1617 goto error_return;
1618 }
1619
1620 free (allocated);
1621 return true;
1622
1623 error_return:
1624 free (allocated);
1625 return false;
1626 }
1627
1628 /* Read in and swap the external relocs. */
1629
1630 bool
1631 elf_slurp_reloc_table (bfd *abfd,
1632 asection *asect,
1633 asymbol **symbols,
1634 bool dynamic)
1635 {
1636 const struct elf_backend_data * const bed = get_elf_backend_data (abfd);
1637 struct bfd_elf_section_data * const d = elf_section_data (asect);
1638 Elf_Internal_Shdr *rel_hdr;
1639 Elf_Internal_Shdr *rel_hdr2;
1640 bfd_size_type reloc_count;
1641 bfd_size_type reloc_count2;
1642 arelent *relents;
1643 size_t amt;
1644
1645 if (asect->relocation != NULL)
1646 return true;
1647
1648 if (! dynamic)
1649 {
1650 if ((asect->flags & SEC_RELOC) == 0
1651 || asect->reloc_count == 0)
1652 return true;
1653
1654 rel_hdr = d->rel.hdr;
1655 reloc_count = rel_hdr ? NUM_SHDR_ENTRIES (rel_hdr) : 0;
1656 rel_hdr2 = d->rela.hdr;
1657 reloc_count2 = rel_hdr2 ? NUM_SHDR_ENTRIES (rel_hdr2) : 0;
1658
1659 /* PR 17512: file: 0b4f81b7. */
1660 if (asect->reloc_count != reloc_count + reloc_count2)
1661 return false;
1662 BFD_ASSERT ((rel_hdr && asect->rel_filepos == rel_hdr->sh_offset)
1663 || (rel_hdr2 && asect->rel_filepos == rel_hdr2->sh_offset));
1664
1665 }
1666 else
1667 {
1668 /* Note that ASECT->RELOC_COUNT tends not to be accurate in this
1669 case because relocations against this section may use the
1670 dynamic symbol table, and in that case bfd_section_from_shdr
1671 in elf.c does not update the RELOC_COUNT. */
1672 if (asect->size == 0)
1673 return true;
1674
1675 rel_hdr = &d->this_hdr;
1676 reloc_count = NUM_SHDR_ENTRIES (rel_hdr);
1677 rel_hdr2 = NULL;
1678 reloc_count2 = 0;
1679 }
1680
1681 if (_bfd_mul_overflow (reloc_count + reloc_count2, sizeof (arelent), &amt))
1682 {
1683 bfd_set_error (bfd_error_file_too_big);
1684 return false;
1685 }
1686 relents = (arelent *) bfd_alloc (abfd, amt);
1687 if (relents == NULL)
1688 return false;
1689
1690 if (rel_hdr
1691 && !elf_slurp_reloc_table_from_section (abfd, asect,
1692 rel_hdr, reloc_count,
1693 relents,
1694 symbols, dynamic))
1695 return false;
1696
1697 if (rel_hdr2
1698 && !elf_slurp_reloc_table_from_section (abfd, asect,
1699 rel_hdr2, reloc_count2,
1700 relents + reloc_count,
1701 symbols, dynamic))
1702 return false;
1703
1704 if (!bed->slurp_secondary_relocs (abfd, asect, symbols, dynamic))
1705 return false;
1706
1707 asect->relocation = relents;
1708 return true;
1709 }
1710
1711 #if DEBUG & 2
1712 static void
1713 elf_debug_section (int num, Elf_Internal_Shdr *hdr)
1714 {
1715 fprintf (stderr, "\nSection#%d '%s' 0x%.8lx\n", num,
1716 hdr->bfd_section != NULL ? hdr->bfd_section->name : "",
1717 (long) hdr);
1718 fprintf (stderr,
1719 "sh_name = %ld\tsh_type = %ld\tsh_flags = %ld\n",
1720 (long) hdr->sh_name,
1721 (long) hdr->sh_type,
1722 (long) hdr->sh_flags);
1723 fprintf (stderr,
1724 "sh_addr = %ld\tsh_offset = %ld\tsh_size = %ld\n",
1725 (long) hdr->sh_addr,
1726 (long) hdr->sh_offset,
1727 (long) hdr->sh_size);
1728 fprintf (stderr,
1729 "sh_link = %ld\tsh_info = %ld\tsh_addralign = %ld\n",
1730 (long) hdr->sh_link,
1731 (long) hdr->sh_info,
1732 (long) hdr->sh_addralign);
1733 fprintf (stderr, "sh_entsize = %ld\n",
1734 (long) hdr->sh_entsize);
1735 fflush (stderr);
1736 }
1737 #endif
1738
1739 #if DEBUG & 1
1740 static void
1741 elf_debug_file (Elf_Internal_Ehdr *ehdrp)
1742 {
1743 fprintf (stderr, "e_entry = 0x%.8lx\n", (long) ehdrp->e_entry);
1744 fprintf (stderr, "e_phoff = %ld\n", (long) ehdrp->e_phoff);
1745 fprintf (stderr, "e_phnum = %ld\n", (long) ehdrp->e_phnum);
1746 fprintf (stderr, "e_phentsize = %ld\n", (long) ehdrp->e_phentsize);
1747 fprintf (stderr, "e_shoff = %ld\n", (long) ehdrp->e_shoff);
1748 fprintf (stderr, "e_shnum = %ld\n", (long) ehdrp->e_shnum);
1749 fprintf (stderr, "e_shentsize = %ld\n", (long) ehdrp->e_shentsize);
1750 }
1751 #endif
1752 \f
1753 /* Create a new BFD as if by bfd_openr. Rather than opening a file,
1754 reconstruct an ELF file by reading the segments out of remote
1755 memory based on the ELF file header at EHDR_VMA and the ELF program
1756 headers it points to. If non-zero, SIZE is the known extent of the
1757 object. If not null, *LOADBASEP is filled in with the difference
1758 between the VMAs from which the segments were read, and the VMAs
1759 the file headers (and hence BFD's idea of each section's VMA) put
1760 them at.
1761
1762 The function TARGET_READ_MEMORY is called to copy LEN bytes from
1763 the remote memory at target address VMA into the local buffer at
1764 MYADDR; it should return zero on success or an `errno' code on
1765 failure. TEMPL must be a BFD for a target with the word size and
1766 byte order found in the remote memory. */
1767
1768 bfd *
1769 NAME(_bfd_elf,bfd_from_remote_memory)
1770 (bfd *templ,
1771 bfd_vma ehdr_vma /* Bytes. */,
1772 bfd_size_type size /* Octets. */,
1773 bfd_vma *loadbasep /* Bytes. */,
1774 int (*target_read_memory) (bfd_vma, bfd_byte *, bfd_size_type))
1775 /* (Bytes , , octets ). */
1776 {
1777 Elf_External_Ehdr x_ehdr; /* Elf file header, external form */
1778 Elf_Internal_Ehdr i_ehdr; /* Elf file header, internal form */
1779 Elf_External_Phdr *x_phdrs;
1780 Elf_Internal_Phdr *i_phdrs, *last_phdr, *first_phdr;
1781 bfd *nbfd;
1782 struct bfd_in_memory *bim;
1783 bfd_byte *contents;
1784 int err;
1785 unsigned int i;
1786 bfd_vma high_offset;
1787 bfd_vma shdr_end;
1788 bfd_vma loadbase; /* Bytes. */
1789 size_t amt;
1790 unsigned int opb = bfd_octets_per_byte (templ, NULL);
1791
1792 /* Read in the ELF header in external format. */
1793 err = target_read_memory (ehdr_vma, (bfd_byte *) &x_ehdr, sizeof x_ehdr);
1794 if (err)
1795 {
1796 bfd_set_error (bfd_error_system_call);
1797 errno = err;
1798 return NULL;
1799 }
1800
1801 /* Now check to see if we have a valid ELF file, and one that BFD can
1802 make use of. The magic number must match, the address size ('class')
1803 and byte-swapping must match our XVEC entry. */
1804
1805 if (! elf_file_p (&x_ehdr)
1806 || x_ehdr.e_ident[EI_VERSION] != EV_CURRENT
1807 || x_ehdr.e_ident[EI_CLASS] != ELFCLASS)
1808 {
1809 bfd_set_error (bfd_error_wrong_format);
1810 return NULL;
1811 }
1812
1813 /* Check that file's byte order matches xvec's */
1814 switch (x_ehdr.e_ident[EI_DATA])
1815 {
1816 case ELFDATA2MSB: /* Big-endian */
1817 if (! bfd_header_big_endian (templ))
1818 {
1819 bfd_set_error (bfd_error_wrong_format);
1820 return NULL;
1821 }
1822 break;
1823 case ELFDATA2LSB: /* Little-endian */
1824 if (! bfd_header_little_endian (templ))
1825 {
1826 bfd_set_error (bfd_error_wrong_format);
1827 return NULL;
1828 }
1829 break;
1830 case ELFDATANONE: /* No data encoding specified */
1831 default: /* Unknown data encoding specified */
1832 bfd_set_error (bfd_error_wrong_format);
1833 return NULL;
1834 }
1835
1836 elf_swap_ehdr_in (templ, &x_ehdr, &i_ehdr);
1837
1838 /* The file header tells where to find the program headers.
1839 These are what we use to actually choose what to read. */
1840
1841 if (i_ehdr.e_phentsize != sizeof (Elf_External_Phdr) || i_ehdr.e_phnum == 0)
1842 {
1843 bfd_set_error (bfd_error_wrong_format);
1844 return NULL;
1845 }
1846
1847 if (_bfd_mul_overflow (i_ehdr.e_phnum,
1848 sizeof (*x_phdrs) + sizeof (*i_phdrs), &amt))
1849 {
1850 bfd_set_error (bfd_error_file_too_big);
1851 return NULL;
1852 }
1853 x_phdrs = (Elf_External_Phdr *) bfd_malloc (amt);
1854 if (x_phdrs == NULL)
1855 return NULL;
1856 err = target_read_memory (ehdr_vma + i_ehdr.e_phoff, (bfd_byte *) x_phdrs,
1857 i_ehdr.e_phnum * sizeof x_phdrs[0]);
1858 if (err)
1859 {
1860 free (x_phdrs);
1861 bfd_set_error (bfd_error_system_call);
1862 errno = err;
1863 return NULL;
1864 }
1865 i_phdrs = (Elf_Internal_Phdr *) &x_phdrs[i_ehdr.e_phnum];
1866
1867 high_offset = 0;
1868 loadbase = 0;
1869 first_phdr = NULL;
1870 last_phdr = NULL;
1871 for (i = 0; i < i_ehdr.e_phnum; ++i)
1872 {
1873 elf_swap_phdr_in (templ, &x_phdrs[i], &i_phdrs[i]);
1874 if (i_phdrs[i].p_type == PT_LOAD)
1875 {
1876 bfd_vma segment_end = i_phdrs[i].p_offset + i_phdrs[i].p_filesz;
1877
1878 if (segment_end > high_offset)
1879 {
1880 high_offset = segment_end;
1881 last_phdr = &i_phdrs[i];
1882 }
1883
1884 /* If this program header covers offset zero, where the file
1885 header sits, then we can figure out the loadbase. */
1886 if (first_phdr == NULL)
1887 {
1888 bfd_vma p_offset = i_phdrs[i].p_offset; /* Octets. */
1889 bfd_vma p_vaddr = i_phdrs[i].p_vaddr; /* Octets. */
1890
1891 if (i_phdrs[i].p_align > 1)
1892 {
1893 p_offset &= -(i_phdrs[i].p_align * opb);
1894 p_vaddr &= -(i_phdrs[i].p_align * opb);
1895 }
1896 if (p_offset == 0)
1897 {
1898 loadbase = ehdr_vma - p_vaddr / opb;
1899 first_phdr = &i_phdrs[i];
1900 }
1901 }
1902 }
1903 }
1904 if (high_offset == 0)
1905 {
1906 /* There were no PT_LOAD segments, so we don't have anything to read. */
1907 free (x_phdrs);
1908 bfd_set_error (bfd_error_wrong_format);
1909 return NULL;
1910 }
1911
1912 shdr_end = 0;
1913 if (i_ehdr.e_shoff != 0 && i_ehdr.e_shnum != 0 && i_ehdr.e_shentsize != 0)
1914 {
1915 shdr_end = i_ehdr.e_shoff + i_ehdr.e_shnum * i_ehdr.e_shentsize;
1916
1917 if (last_phdr->p_filesz != last_phdr->p_memsz)
1918 {
1919 /* If the last PT_LOAD header has a bss area then ld.so will
1920 have cleared anything past p_filesz, zapping the section
1921 headers. */
1922 }
1923 else if (size >= shdr_end)
1924 high_offset = size;
1925 else
1926 {
1927 bfd_vma page_size = get_elf_backend_data (templ)->minpagesize;
1928 bfd_vma segment_end = last_phdr->p_offset + last_phdr->p_filesz;
1929
1930 /* Assume we loaded full pages, allowing us to sometimes see
1931 section headers. */
1932 if (page_size > 1 && shdr_end > segment_end)
1933 {
1934 bfd_vma page_end = (segment_end + page_size - 1) & -page_size;
1935
1936 if (page_end >= shdr_end)
1937 /* Whee, section headers covered. */
1938 high_offset = shdr_end;
1939 }
1940 }
1941 }
1942
1943 /* Now we know the size of the whole image we want read in. */
1944 contents = (bfd_byte *) bfd_zmalloc (high_offset);
1945 if (contents == NULL)
1946 {
1947 free (x_phdrs);
1948 return NULL;
1949 }
1950
1951 for (i = 0; i < i_ehdr.e_phnum; ++i)
1952 if (i_phdrs[i].p_type == PT_LOAD)
1953 {
1954 bfd_vma start = i_phdrs[i].p_offset; /* Octets. */
1955 bfd_vma end = start + i_phdrs[i].p_filesz; /* Octets. */
1956 bfd_vma vaddr = i_phdrs[i].p_vaddr; /* Octets. */
1957
1958 /* Extend the beginning of the first pt_load to cover file
1959 header and program headers, if we proved earlier that its
1960 aligned offset is 0. */
1961 if (first_phdr == &i_phdrs[i])
1962 {
1963 vaddr -= start;
1964 start = 0;
1965 }
1966 /* Extend the end of the last pt_load to cover section headers. */
1967 if (last_phdr == &i_phdrs[i])
1968 end = high_offset;
1969 err = target_read_memory (loadbase + vaddr / opb,
1970 contents + start, end - start);
1971 if (err)
1972 {
1973 free (x_phdrs);
1974 free (contents);
1975 bfd_set_error (bfd_error_system_call);
1976 errno = err;
1977 return NULL;
1978 }
1979 }
1980 free (x_phdrs);
1981
1982 /* If the segments visible in memory didn't include the section headers,
1983 then clear them from the file header. */
1984 if (high_offset < shdr_end)
1985 {
1986 memset (&x_ehdr.e_shoff, 0, sizeof x_ehdr.e_shoff);
1987 memset (&x_ehdr.e_shnum, 0, sizeof x_ehdr.e_shnum);
1988 memset (&x_ehdr.e_shstrndx, 0, sizeof x_ehdr.e_shstrndx);
1989 }
1990
1991 /* This will normally have been in the first PT_LOAD segment. But it
1992 conceivably could be missing, and we might have just changed it. */
1993 memcpy (contents, &x_ehdr, sizeof x_ehdr);
1994
1995 /* Now we have a memory image of the ELF file contents. Make a BFD. */
1996 bim = (struct bfd_in_memory *) bfd_malloc (sizeof (struct bfd_in_memory));
1997 if (bim == NULL)
1998 {
1999 free (contents);
2000 return NULL;
2001 }
2002 nbfd = _bfd_new_bfd ();
2003 if (nbfd == NULL
2004 || !bfd_set_filename (nbfd, "<in-memory>"))
2005 {
2006 free (bim);
2007 free (contents);
2008 return NULL;
2009 }
2010 nbfd->xvec = templ->xvec;
2011 bim->size = high_offset;
2012 bim->buffer = contents;
2013 nbfd->iostream = bim;
2014 nbfd->flags = BFD_IN_MEMORY;
2015 nbfd->iovec = &_bfd_memory_iovec;
2016 nbfd->origin = 0;
2017 nbfd->direction = read_direction;
2018 nbfd->mtime = time (NULL);
2019 nbfd->mtime_set = true;
2020
2021 if (loadbasep)
2022 *loadbasep = loadbase;
2023 return nbfd;
2024 }
2025
2026 /* Function for ELF_R_INFO. */
2027
2028 bfd_vma
2029 NAME(elf,r_info) (bfd_vma sym, bfd_vma type)
2030 {
2031 return ELF_R_INFO (sym, type);
2032 }
2033
2034 /* Function for ELF_R_SYM. */
2035
2036 bfd_vma
2037 NAME(elf,r_sym) (bfd_vma r_info)
2038 {
2039 return ELF_R_SYM (r_info);
2040 }
2041 \f
2042 #include "elfcore.h"
2043 \f
2044 /* Size-dependent data and functions. */
2045 const struct elf_size_info NAME(_bfd_elf,size_info) = {
2046 sizeof (Elf_External_Ehdr),
2047 sizeof (Elf_External_Phdr),
2048 sizeof (Elf_External_Shdr),
2049 sizeof (Elf_External_Rel),
2050 sizeof (Elf_External_Rela),
2051 sizeof (Elf_External_Sym),
2052 sizeof (Elf_External_Dyn),
2053 sizeof (Elf_External_Note),
2054 4,
2055 1,
2056 ARCH_SIZE, LOG_FILE_ALIGN,
2057 ELFCLASS, EV_CURRENT,
2058 elf_write_out_phdrs,
2059 elf_write_shdrs_and_ehdr,
2060 elf_checksum_contents,
2061 elf_write_relocs,
2062 elf_swap_symbol_in,
2063 elf_swap_symbol_out,
2064 elf_slurp_reloc_table,
2065 elf_slurp_symbol_table,
2066 elf_swap_dyn_in,
2067 elf_swap_dyn_out,
2068 elf_swap_reloc_in,
2069 elf_swap_reloc_out,
2070 elf_swap_reloca_in,
2071 elf_swap_reloca_out
2072 };