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