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1 /* Internal interfaces for libelf.
2    Copyright (C) 1998-2010, 2015, 2016 Red Hat, Inc.
3    This file is part of elfutils.
4    Contributed by Ulrich Drepper <drepper@redhat.com>, 1998.
5 
6    This file is free software; you can redistribute it and/or modify
7    it under the terms of either
8 
9      * the GNU Lesser General Public License as published by the Free
10        Software Foundation; either version 3 of the License, or (at
11        your option) any later version
12 
13    or
14 
15      * the GNU General Public License as published by the Free
16        Software Foundation; either version 2 of the License, or (at
17        your option) any later version
18 
19    or both in parallel, as here.
20 
21    elfutils is distributed in the hope that it will be useful, but
22    WITHOUT ANY WARRANTY; without even the implied warranty of
23    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
24    General Public License for more details.
25 
26    You should have received copies of the GNU General Public License and
27    the GNU Lesser General Public License along with this program.  If
28    not, see <http://www.gnu.org/licenses/>.  */
29 
30 #ifndef _LIBELFP_H
31 #define _LIBELFP_H 1
32 
33 #include <ar.h>
34 #include <gelf.h>
35 
36 #include <errno.h>
37 #include <stdbool.h>
38 #include <stdint.h>
39 #include <stdio.h>
40 #include <string.h>
41 
42 #include <system.h>
43 
44 /* Helper Macros to write 32 bit and 64 bit functions.  */
45 #define __elfw2_(Bits, Name) __elf##Bits##_##Name
46 #define elfw2_(Bits, Name) elf##Bits##_##Name
47 #define ElfW2_(Bits, Name) Elf##Bits##_##Name
48 #define ELFW2_(Bits, Name) ELF##Bits##_##Name
49 #define ELFW_(Name, Bits) Name##Bits
50 #define __elfw2(Bits, Name) __elfw2_(Bits, Name)
51 #define elfw2(Bits, Name) elfw2_(Bits, Name)
52 #define ElfW2(Bits, Name) ElfW2_(Bits, Name)
53 #define ELFW2(Bits, Name) ELFW2_(Bits, Name)
54 #define ELFW(Name, Bits)  ELFW_(Name, Bits)
55 
56 
57 /* Sizes of the external types, for 32 bits objects.  */
58 #define ELF32_FSZ_ADDR   4
59 #define ELF32_FSZ_OFF    4
60 #define ELF32_FSZ_HALF   2
61 #define ELF32_FSZ_WORD   4
62 #define ELF32_FSZ_SWORD  4
63 #define ELF32_FSZ_XWORD  8
64 #define ELF32_FSZ_SXWORD 8
65 
66 /* Same for 64 bits objects.  */
67 #define ELF64_FSZ_ADDR   8
68 #define ELF64_FSZ_OFF    8
69 #define ELF64_FSZ_HALF   2
70 #define ELF64_FSZ_WORD   4
71 #define ELF64_FSZ_SWORD  4
72 #define ELF64_FSZ_XWORD  8
73 #define ELF64_FSZ_SXWORD 8
74 
75 
76 /* This is an extension of the ELF_F_* enumeration.  The values here are
77    not part of the library interface, they are only used internally.  */
78 enum
79 {
80   ELF_F_MMAPPED = 0x40,
81   ELF_F_MALLOCED = 0x80,
82   ELF_F_FILEDATA = 0x100
83 };
84 
85 
86 /* Get definition of all the external types.  */
87 #include "exttypes.h"
88 
89 
90 /* Error values.  */
91 enum
92 {
93   ELF_E_NOERROR = 0,
94   ELF_E_UNKNOWN_ERROR,
95   ELF_E_UNKNOWN_VERSION,
96   ELF_E_UNKNOWN_TYPE,
97   ELF_E_INVALID_HANDLE,
98   ELF_E_SOURCE_SIZE,
99   ELF_E_DEST_SIZE,
100   ELF_E_INVALID_ENCODING,
101   ELF_E_NOMEM,
102   ELF_E_INVALID_FILE,
103   ELF_E_INVALID_ELF,
104   ELF_E_INVALID_OP,
105   ELF_E_NO_VERSION,
106   ELF_E_INVALID_CMD,
107   ELF_E_RANGE,
108   ELF_E_ARCHIVE_FMAG,
109   ELF_E_INVALID_ARCHIVE,
110   ELF_E_NO_ARCHIVE,
111   ELF_E_NO_INDEX,
112   ELF_E_READ_ERROR,
113   ELF_E_WRITE_ERROR,
114   ELF_E_INVALID_CLASS,
115   ELF_E_INVALID_INDEX,
116   ELF_E_INVALID_OPERAND,
117   ELF_E_INVALID_SECTION,
118   ELF_E_INVALID_COMMAND,
119   ELF_E_WRONG_ORDER_EHDR,
120   ELF_E_FD_DISABLED,
121   ELF_E_FD_MISMATCH,
122   ELF_E_OFFSET_RANGE,
123   ELF_E_NOT_NUL_SECTION,
124   ELF_E_DATA_MISMATCH,
125   ELF_E_INVALID_SECTION_HEADER,
126   ELF_E_INVALID_DATA,
127   ELF_E_DATA_ENCODING,
128   ELF_E_SECTION_TOO_SMALL,
129   ELF_E_INVALID_ALIGN,
130   ELF_E_INVALID_SHENTSIZE,
131   ELF_E_UPDATE_RO,
132   ELF_E_NOFILE,
133   ELF_E_GROUP_NOT_REL,
134   ELF_E_INVALID_PHDR,
135   ELF_E_NO_PHDR,
136   ELF_E_INVALID_OFFSET,
137   ELF_E_INVALID_SECTION_TYPE,
138   ELF_E_INVALID_SECTION_FLAGS,
139   ELF_E_NOT_COMPRESSED,
140   ELF_E_ALREADY_COMPRESSED,
141   ELF_E_UNKNOWN_COMPRESSION_TYPE,
142   ELF_E_COMPRESS_ERROR,
143   ELF_E_DECOMPRESS_ERROR,
144   /* Keep this as the last entry.  */
145   ELF_E_NUM
146 };
147 
148 
149 /* The visible `Elf_Data' type is not sufficient for some operations due
150    to a misdesigned interface.  Extend it for internal purposes.  */
151 typedef struct
152 {
153   Elf_Data d;
154   Elf_Scn *s;
155 } Elf_Data_Scn;
156 
157 
158 /* List of `Elf_Data' descriptors.  This is what makes up the section
159    contents.  */
160 typedef struct Elf_Data_List
161 {
162   /* `data' *must* be the first element in the struct.  */
163   Elf_Data_Scn data;
164   struct Elf_Data_List *next;
165   int flags;
166 } Elf_Data_List;
167 
168 
169 /* Descriptor for ELF section.  */
170 struct Elf_Scn
171 {
172   /* We have to distinguish several different situations:
173 
174      1. the section is user created.  Therefore there is no file or memory
175         region to read the data from.  Here we have two different subcases:
176 
177         a) data was not yet added (before the first `elf_newdata' call)
178 
179         b) at least one data set is available
180 
181      2. this is a section from a file/memory region.  We have to read the
182         current content in one data block if we have to.  But we don't
183         read the data until it is necessary.  So we have the subcases:
184 
185         a) the section in the file has size zero (for whatever reason)
186 
187         b) the data of the file is not (yet) read
188 
189         c) the data is read and available.
190 
191      In addition to this we have different data sets, the raw and the converted
192      data.  This distinction only exists for the data read from the file.
193      All user-added data set (all but the first when read from the file or
194      all of them for user-create sections) are the same in both formats.
195      We don't create the converted data before it is necessary.
196 
197      The `data_read' element signals whether data is available in the
198      raw format.
199 
200      If there is data from the file/memory region or if read one data
201      set is added the `rawdata_list_read' pointer in non-NULL and points
202      to the last filled data set.  `raw_datalist_rear' is therefore NULL
203      only if there is no data set at all.
204 
205      This so far allows to distinguish all but two cases (given that the
206      `rawdata_list' and `data_list' entries are initialized to zero) is
207      between not yet loaded data from the file/memory region and a section
208      with zero size and type ELF_T_BYTE.   */
209   Elf_Data_List data_list;	/* List of data buffers.  */
210   Elf_Data_List *data_list_rear; /* Pointer to the rear of the data list. */
211 
212   Elf_Data_Scn rawdata;		/* Uninterpreted data of the section.  */
213 
214   int data_read;		/* Nonzero if the section was created by the
215 				   user or if the data from the file/memory
216 				   is read.  */
217   int shndx_index;		/* Index of the extended section index
218 				   table for this symbol table (if this
219 				   section is a symbol table).  */
220 
221   size_t index;			/* Index of this section.  */
222   struct Elf *elf;		/* The underlying ELF file.  */
223 
224   union
225   {
226     Elf32_Shdr *e32;		/* Pointer to 32bit section header.  */
227     Elf64_Shdr *e64;		/* Pointer to 64bit section header.  */
228   } shdr;
229 
230   unsigned int shdr_flags;	/* Section header modified?  */
231   unsigned int flags;		/* Section changed in size?
232 				   ELF_F_MALLOCED for a Elf_Data_Chunk
233 				   dummy_scn means the rawchunks
234 				   data.d.d_buf was malloced. For normal
235 				   sections it means rawdata_base was
236 				   malloced (by elf_compress) even if
237 				   the Elf was mmapped.  */
238 
239   char *rawdata_base;		/* The unmodified data of the section.  */
240   char *data_base;		/* The converted data of the section.  */
241 
242   char *zdata_base;		/* The uncompressed data of the section.  */
243   size_t zdata_size;		/* If zdata_base != NULL, the size of data.  */
244   size_t zdata_align;		/* If zdata_base != NULL, the addralign.  */
245 
246   struct Elf_ScnList *list;	/* Pointer to the section list element the
247 				   data is in.  */
248 };
249 
250 
251 /* List of section.  */
252 typedef struct Elf_ScnList
253 {
254   unsigned int cnt;		/* Number of elements of 'data' used.  */
255   unsigned int max;		/* Number of elements of 'data' allocated.  */
256   struct Elf_ScnList *next;	/* Next block of sections.  */
257   struct Elf_Scn data[0];	/* Section data.  */
258 } Elf_ScnList;
259 
260 
261 /* elf_getdata_rawchunk result.  */
262 typedef struct Elf_Data_Chunk
263 {
264   Elf_Data_Scn data;
265   union
266   {
267     Elf_Scn dummy_scn;
268     struct Elf_Data_Chunk *next;
269   };
270   int64_t offset;		/* The original raw offset in the Elf image.  */
271 } Elf_Data_Chunk;
272 
273 
274 /* The ELF descriptor.  */
275 struct Elf
276 {
277   /* Address to which the file was mapped.  NULL if not mapped.  */
278   void *map_address;
279 
280   /* When created for an archive member this points to the descriptor
281      for the archive. */
282   Elf *parent;
283   Elf *next;             /* Used in list of archive descriptors.  */
284 
285   /* What kind of file is underneath (ELF file, archive...).  */
286   Elf_Kind kind;
287 
288   /* Command used to create this descriptor.  */
289   Elf_Cmd cmd;
290 
291   /* The binary class.  */
292   unsigned int class;
293 
294   /* The used file descriptor.  -1 if not available anymore.  */
295   int fildes;
296 
297   /* Offset in the archive this file starts or zero.  */
298   int64_t start_offset;
299 
300   /* Size of the file in the archive or the entire file size, or ~0
301      for an (yet) unknown size.  */
302   size_t maximum_size;
303 
304   /* Describes the way the memory was allocated and if the dirty bit is
305      signalled it means that the whole file has to be rewritten since
306      the layout changed.  */
307   int flags;
308 
309   /* Reference counting for the descriptor.  */
310   int ref_count;
311 
312   /* Lock to handle multithreaded programs.  */
313   rwlock_define (,lock);
314 
315   union
316   {
317     struct
318     {
319       /* The next fields are only useful when testing for ==/!= NULL.  */
320       void *ehdr;
321       void *shdr;
322       void *phdr;
323 
324       Elf_ScnList *scns_last;	/* Last element in the section list.
325 				   If NULL the data has not yet been
326 				   read from the file.  */
327       Elf_Data_Chunk *rawchunks; /* List of elf_getdata_rawchunk results.  */
328       unsigned int scnincr;	/* Number of sections allocate the last
329 				   time.  */
330       int ehdr_flags;		/* Flags (dirty) for ELF header.  */
331       int phdr_flags;		/* Flags (dirty|malloc) for program header.  */
332       int shdr_malloced;	/* Nonzero if shdr array was allocated.  */
333       off_t sizestr_offset;	/* Offset of the size string in the parent
334 				   if this is an archive member.  */
335     } elf;
336 
337     struct
338     {
339       Elf32_Ehdr *ehdr;		/* Pointer to the ELF header.  This is
340 				   never malloced.  */
341       Elf32_Shdr *shdr;		/* Used when reading from a file.  */
342       Elf32_Phdr *phdr;		/* Pointer to the program header array.  */
343       Elf_ScnList *scns_last;	/* Last element in the section list.
344 				   If NULL the data has not yet been
345 				   read from the file.  */
346       Elf_Data_Chunk *rawchunks; /* List of elf_getdata_rawchunk results.  */
347       unsigned int scnincr;	/* Number of sections allocate the last
348 				   time.  */
349       int ehdr_flags;		/* Flags (dirty) for ELF header.  */
350       int phdr_flags;		/* Flags (dirty|malloc) for program header.  */
351       int shdr_malloced;	/* Nonzero if shdr array was allocated.  */
352       int64_t sizestr_offset;	/* Offset of the size string in the parent
353 				   if this is an archive member.  */
354       Elf32_Ehdr ehdr_mem;	/* Memory used for ELF header when not
355 				   mmaped.  */
356       char __e32scnspad[sizeof (Elf64_Ehdr) - sizeof (Elf32_Ehdr)];
357 
358       /* The section array.  */
359       Elf_ScnList scns;
360     } elf32;
361 
362     struct
363     {
364       Elf64_Ehdr *ehdr;		/* Pointer to the ELF header.  This is
365 				   never malloced.  */
366       Elf64_Shdr *shdr;		/* Used when reading from a file.  */
367       Elf64_Phdr *phdr;		/* Pointer to the program header array.  */
368       Elf_ScnList *scns_last;	/* Last element in the section list.
369 				   If NULL the data has not yet been
370 				   read from the file.  */
371       Elf_Data_Chunk *rawchunks; /* List of elf_getdata_rawchunk results.  */
372       unsigned int scnincr;	/* Number of sections allocate the last
373 				   time.  */
374       int ehdr_flags;		/* Flags (dirty) for ELF header.  */
375       int phdr_flags;		/* Flags (dirty|malloc) for program header.  */
376       int shdr_malloced;	/* Nonzero if shdr array was allocated.  */
377       int64_t sizestr_offset;	/* Offset of the size string in the parent
378 				   if this is an archive member.  */
379       Elf64_Ehdr ehdr_mem;	/* Memory used for ELF header when not
380 				   mmaped.  */
381 
382       /* The section array.  */
383       Elf_ScnList scns;
384     } elf64;
385 
386     struct
387     {
388       Elf *children;		/* List of all descriptors for this archive. */
389       Elf_Arsym *ar_sym;	/* Symbol table returned by elf_getarsym.  */
390       size_t ar_sym_num;	/* Number of entries in `ar_sym'.  */
391       char *long_names;		/* If no index is available but long names
392 				   are used this elements points to the data.*/
393       size_t long_names_len;	/* Length of the long name table.  */
394       int64_t offset;		/* Offset in file we are currently at.
395 				   elf_next() advances this to the next
396 				   member of the archive.  */
397       Elf_Arhdr elf_ar_hdr;	/* Structure returned by 'elf_getarhdr'.  */
398       struct ar_hdr ar_hdr;	/* Header read from file.  */
399       char ar_name[16];		/* NUL terminated ar_name of elf_ar_hdr.  */
400       char raw_name[17];	/* This is a buffer for the NUL terminated
401 				   named raw_name used in the elf_ar_hdr.  */
402     } ar;
403   } state;
404 
405   /* There absolutely never must be anything following the union.  */
406 };
407 
408 /* Type of the conversion functions.  These functions will convert the
409    byte order.  */
410 typedef void (*xfct_t) (void *, const void *, size_t, int);
411 
412 /* The table with the function pointers.  */
413 extern const xfct_t __elf_xfctstom[ELFCLASSNUM - 1][ELF_T_NUM]
414   attribute_hidden;
415 
416 
417 /* Array with sizes of the external types indexed by ELF version, binary
418    class, and type. */
419 extern const size_t __libelf_type_sizes[ELFCLASSNUM - 1][ELF_T_NUM]
420   attribute_hidden;
421 /* We often have to access the size for a type in the current version.  */
422 # define elf_typesize(class,type,n) \
423   (__libelf_type_sizes[ELFW(ELFCLASS,class) - 1][type] * n)
424 
425 /* The byte value used for filling gaps.  */
426 extern int __libelf_fill_byte attribute_hidden;
427 
428 /* EV_CURRENT if the version was set, EV_NONE otherwise.  */
429 extern unsigned int __libelf_version attribute_hidden;
430 
431 /* Array with alignment requirements of the internal types indexed by
432    binary class, and type. */
433 extern const uint_fast8_t __libelf_type_aligns[ELFCLASSNUM - 1][ELF_T_NUM]
434   attribute_hidden;
435 # define __libelf_type_align(class, type)	\
436     (__libelf_type_aligns[class - 1][type] ?: 1)
437 
438 /* Given an GElf_Ehdr handle and a section type returns the Elf_Data d_type.
439    Should not be called when SHF_COMPRESSED is set, the d_type should
440    be ELF_T_BYTE.  */
441 extern Elf_Type __libelf_data_type (GElf_Ehdr *ehdr,
442 				    int sh_type, GElf_Xword align)
443   internal_function;
444 
445 
446 /* Create Elf descriptor from memory image.  */
447 extern Elf *__libelf_read_mmaped_file (int fildes, void *map_address,
448 				       int64_t offset, size_t maxsize,
449 				       Elf_Cmd cmd, Elf *parent)
450      internal_function;
451 
452 /* Set error value.  */
453 extern void __libelf_seterrno (int value) internal_function;
454 
455 /* Get the next archive header.  */
456 extern int __libelf_next_arhdr_wrlock (Elf *elf) internal_function;
457 
458 /* Read all of the file associated with the descriptor.  */
459 extern char *__libelf_readall (Elf *elf) internal_function;
460 
461 /* Read the complete section table and convert the byte order if necessary.  */
462 extern int __libelf_readsections (Elf *elf) internal_function;
463 
464 /* Store the information for the raw data in the `rawdata_list' element.  */
465 extern int __libelf_set_rawdata (Elf_Scn *scn) internal_function;
466 extern int __libelf_set_rawdata_wrlock (Elf_Scn *scn) internal_function;
467 
468 
469 /* Helper functions for elf_update.  */
470 extern int64_t __elf32_updatenull_wrlock (Elf *elf, int *change_bop,
471 					  size_t shnum) internal_function;
472 extern int64_t __elf64_updatenull_wrlock (Elf *elf, int *change_bop,
473 					  size_t shnum) internal_function;
474 
475 extern int __elf32_updatemmap (Elf *elf, int change_bo, size_t shnum)
476      internal_function;
477 extern int __elf64_updatemmap (Elf *elf, int change_bo, size_t shnum)
478      internal_function;
479 extern int __elf32_updatefile (Elf *elf, int change_bo, size_t shnum)
480      internal_function;
481 extern int __elf64_updatefile (Elf *elf, int change_bo, size_t shnum)
482      internal_function;
483 
484 
485 /* Alias for exported functions to avoid PLT entries, and
486    rdlock/wrlock variants of these functions.  */
487 extern int __elf_end_internal (Elf *__elf) attribute_hidden;
488 extern Elf *__elf_begin_internal (int __fildes, Elf_Cmd __cmd, Elf *__ref)
489      attribute_hidden;
490 extern Elf32_Ehdr *__elf32_getehdr_wrlock (Elf *__elf) internal_function;
491 extern Elf64_Ehdr *__elf64_getehdr_wrlock (Elf *__elf) internal_function;
492 extern Elf32_Ehdr *__elf32_newehdr_internal (Elf *__elf) attribute_hidden;
493 extern Elf64_Ehdr *__elf64_newehdr_internal (Elf *__elf) attribute_hidden;
494 extern Elf32_Phdr *__elf32_getphdr_internal (Elf *__elf) attribute_hidden;
495 extern Elf64_Phdr *__elf64_getphdr_internal (Elf *__elf) attribute_hidden;
496 extern Elf32_Phdr *__elf32_getphdr_wrlock (Elf *__elf) attribute_hidden;
497 extern Elf64_Phdr *__elf64_getphdr_wrlock (Elf *__elf) attribute_hidden;
498 extern Elf32_Phdr *__elf32_newphdr_internal (Elf *__elf, size_t __cnt)
499      attribute_hidden;
500 extern Elf64_Phdr *__elf64_newphdr_internal (Elf *__elf, size_t __cnt)
501      attribute_hidden;
502 extern Elf_Scn *__elf32_offscn_internal (Elf *__elf, Elf32_Off __offset)
503      attribute_hidden;
504 extern Elf_Scn *__elf64_offscn_internal (Elf *__elf, Elf64_Off __offset)
505      attribute_hidden;
506 extern int __elf_getphdrnum_rdlock (Elf *__elf, size_t *__dst)
507      internal_function;
508 extern int __elf_getphdrnum_chk_rdlock (Elf *__elf, size_t *__dst)
509      internal_function;
510 extern int __elf_getshdrnum_rdlock (Elf *__elf, size_t *__dst)
511      internal_function;
512 extern int __elf_getshdrstrndx_internal (Elf *__elf, size_t *__dst)
513      attribute_hidden;
514 extern Elf32_Shdr *__elf32_getshdr_rdlock (Elf_Scn *__scn) internal_function;
515 extern Elf64_Shdr *__elf64_getshdr_rdlock (Elf_Scn *__scn) internal_function;
516 extern Elf32_Shdr *__elf32_getshdr_wrlock (Elf_Scn *__scn) internal_function;
517 extern Elf64_Shdr *__elf64_getshdr_wrlock (Elf_Scn *__scn) internal_function;
518 extern Elf_Scn *__elf_getscn_internal (Elf *__elf, size_t __index)
519      attribute_hidden;
520 extern Elf_Scn *__elf_nextscn_internal (Elf *__elf, Elf_Scn *__scn)
521      attribute_hidden;
522 extern int __elf_scnshndx_internal (Elf_Scn *__scn) attribute_hidden;
523 extern Elf_Data *__elf_getdata_internal (Elf_Scn *__scn, Elf_Data *__data)
524      attribute_hidden;
525 extern Elf_Data *__elf_getdata_rdlock (Elf_Scn *__scn, Elf_Data *__data)
526      internal_function;
527 extern Elf_Data *__elf_rawdata_internal (Elf_Scn *__scn, Elf_Data *__data)
528      attribute_hidden;
529 /* Should be called to setup first section data element if
530    data_list_rear is NULL and we know data_read is set and there is
531    raw data available.  Might upgrade the ELF lock from a read to a
532    write lock.  If the lock is already a write lock set wrlocked.  */
533 extern void __libelf_set_data_list_rdlock (Elf_Scn *scn, int wrlocked)
534      internal_function;
535 extern char *__elf_strptr_internal (Elf *__elf, size_t __index,
536 				    size_t __offset) attribute_hidden;
537 extern Elf_Data *__elf32_xlatetom_internal (Elf_Data *__dest,
538 					    const Elf_Data *__src,
539 					    unsigned int __encode)
540      attribute_hidden;
541 extern Elf_Data *__elf64_xlatetom_internal (Elf_Data *__dest,
542 					    const Elf_Data *__src,
543 					    unsigned int __encode)
544      attribute_hidden;
545 extern Elf_Data *__elf32_xlatetof_internal (Elf_Data *__dest,
546 					    const Elf_Data *__src,
547 					    unsigned int __encode)
548      attribute_hidden;
549 extern Elf_Data *__elf64_xlatetof_internal (Elf_Data *__dest,
550 					    const Elf_Data *__src,
551 					    unsigned int __encode)
552      attribute_hidden;
553 extern unsigned int __elf_version_internal (unsigned int __version)
554      attribute_hidden;
555 extern unsigned long int __elf_hash_internal (const char *__string)
556        __attribute__ ((__pure__)) attribute_hidden;
557 extern long int __elf32_checksum_internal (Elf *__elf) attribute_hidden;
558 extern long int __elf64_checksum_internal (Elf *__elf) attribute_hidden;
559 
560 
561 extern GElf_Ehdr *__gelf_getehdr_rdlock (Elf *__elf, GElf_Ehdr *__dest)
562      internal_function;
563 extern size_t __gelf_fsize_internal (Elf *__elf, Elf_Type __type,
564 				     size_t __count, unsigned int __version)
565      attribute_hidden;
566 extern GElf_Shdr *__gelf_getshdr_internal (Elf_Scn *__scn, GElf_Shdr *__dst)
567      attribute_hidden;
568 extern GElf_Sym *__gelf_getsym_internal (Elf_Data *__data, int __ndx,
569 					 GElf_Sym *__dst) attribute_hidden;
570 
571 
572 extern uint32_t __libelf_crc32 (uint32_t crc, unsigned char *buf, size_t len)
573      attribute_hidden;
574 
575 extern void * __libelf_compress (Elf_Scn *scn, size_t hsize, int ei_data,
576 				 size_t *orig_size, size_t *orig_addralign,
577 				 size_t *size, bool force)
578      internal_function;
579 
580 extern void * __libelf_decompress (void *buf_in, size_t size_in,
581 				   size_t size_out) internal_function;
582 extern void * __libelf_decompress_elf (Elf_Scn *scn,
583 				       size_t *size_out, size_t *addralign)
584      internal_function;
585 
586 
587 extern void __libelf_reset_rawdata (Elf_Scn *scn, void *buf, size_t size,
588 				    size_t align, Elf_Type type)
589      internal_function;
590 
591 
592 /* We often have to update a flag iff a value changed.  Make this
593    convenient.  */
594 #define update_if_changed(var, exp, flag) \
595   do {									      \
596     __typeof__ (var) *_var = &(var);					      \
597     __typeof__ (exp) _exp = (exp);					      \
598     if (*_var != _exp)							      \
599       {									      \
600 	*_var = _exp;							      \
601 	(flag) |= ELF_F_DIRTY;						      \
602       }									      \
603   } while (0)
604 
605 /* Align offset to 4 bytes as needed for note name and descriptor data.
606    This is almost always used, except for GNU Property notes, which use
607    8 byte padding...  */
608 #define NOTE_ALIGN4(n)	(((n) + 3) & -4UL)
609 
610 /* Special note padding rule for GNU Property notes.  */
611 #define NOTE_ALIGN8(n)	(((n) + 7) & -8UL)
612 
613 /* Convenience macro.  */
614 #define INVALID_NDX(ndx, type, data) \
615   unlikely ((data)->d_size / sizeof (type) <= (unsigned int) (ndx))
616 
617 #endif  /* libelfP.h */
618