1ELF(5)                     Linux Programmer's Manual                    ELF(5)
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3
4

NAME

6       elf - format of Executable and Linking Format (ELF) files
7

SYNOPSIS

9       #include <elf.h>
10

DESCRIPTION

12       The  header  file  <elf.h>  defines the format of ELF executable binary
13       files.  Amongst these files are normal  executable  files,  relocatable
14       object files, core files, and shared objects.
15
16       An executable file using the ELF file format consists of an ELF header,
17       followed by a program header table or a section header table, or  both.
18       The  ELF  header  is  always  at  offset zero of the file.  The program
19       header table and the section header table's  offset  in  the  file  are
20       defined  in  the  ELF  header.  The two tables describe the rest of the
21       particularities of the file.
22
23       This header file describes the above mentioned headers as C  structures
24       and  also includes structures for dynamic sections, relocation sections
25       and symbol tables.
26
27   Basic types
28       The following types are used for  N-bit  architectures  (N=32,64,  ElfN
29       stands for Elf32 or Elf64, uintN_t stands for uint32_t or uint64_t):
30
31           ElfN_Addr       Unsigned program address, uintN_t
32           ElfN_Off        Unsigned file offset, uintN_t
33           ElfN_Section    Unsigned section index, uint16_t
34           ElfN_Versym     Unsigned version symbol information, uint16_t
35           Elf_Byte        unsigned char
36           ElfN_Half       uint16_t
37           ElfN_Sword      int32_t
38           ElfN_Word       uint32_t
39           ElfN_Sxword     int64_t
40           ElfN_Xword      uint64_t
41
42       (Note:  the  *BSD terminology is a bit different.  There, Elf64_Half is
43       twice as large as Elf32_Half, and Elf64Quarter is  used  for  uint16_t.
44       In  order  to avoid confusion these types are replaced by explicit ones
45       in the below.)
46
47       All data structures that the file format defines follow  the  "natural"
48       size  and  alignment  guidelines for the relevant class.  If necessary,
49       data structures contain explicit padding to ensure 4-byte alignment for
50       4-byte objects, to force structure sizes to a multiple of 4, and so on.
51
52   ELF header (Ehdr)
53       The ELF header is described by the type Elf32_Ehdr or Elf64_Ehdr:
54
55           #define EI_NIDENT 16
56
57           typedef struct {
58               unsigned char e_ident[EI_NIDENT];
59               uint16_t      e_type;
60               uint16_t      e_machine;
61               uint32_t      e_version;
62               ElfN_Addr     e_entry;
63               ElfN_Off      e_phoff;
64               ElfN_Off      e_shoff;
65               uint32_t      e_flags;
66               uint16_t      e_ehsize;
67               uint16_t      e_phentsize;
68               uint16_t      e_phnum;
69               uint16_t      e_shentsize;
70               uint16_t      e_shnum;
71               uint16_t      e_shstrndx;
72           } ElfN_Ehdr;
73
74       The fields have the following meanings:
75
76       e_ident   This  array  of  bytes  specifies  how to interpret the file,
77                 independent of the processor or  the  file's  remaining  con‐
78                 tents.   Within  this  array  everything  is named by macros,
79                 which start with the prefix EI_ and may contain values  which
80                 start with the prefix ELF.  The following macros are defined:
81
82                 EI_MAG0  The  first  byte  of  the  magic number.  It must be
83                          filled with ELFMAG0.  (0: 0x7f)
84
85                 EI_MAG1  The second byte of the magic  number.   It  must  be
86                          filled with ELFMAG1.  (1: 'E')
87
88                 EI_MAG2  The  third  byte  of  the  magic number.  It must be
89                          filled with ELFMAG2.  (2: 'L')
90
91                 EI_MAG3  The fourth byte of the magic  number.   It  must  be
92                          filled with ELFMAG3.  (3: 'F')
93
94                 EI_CLASS The  fifth byte identifies the architecture for this
95                          binary:
96
97                          ELFCLASSNONE  This class is invalid.
98                          ELFCLASS32    This defines the 32-bit  architecture.
99                                        It  supports  machines  with files and
100                                        virtual address spaces up to  4  Giga‐
101                                        bytes.
102                          ELFCLASS64    This defines the 64-bit architecture.
103
104                 EI_DATA  The  sixth  byte  specifies the data encoding of the
105                          processor-specific data  in  the  file.   Currently,
106                          these encodings are supported:
107
108                          ELFDATANONE   Unknown data format.
109                          ELFDATA2LSB   Two's complement, little-endian.
110                          ELFDATA2MSB   Two's complement, big-endian.
111
112                 EI_VERSION
113                          The  seventh  byte  is the version number of the ELF
114                          specification:
115
116                          EV_NONE       Invalid version.
117                          EV_CURRENT    Current version.
118
119                 EI_OSABI The eighth byte identifies the operating system  and
120                          ABI to which the object is targeted.  Some fields in
121                          other ELF structures have flags and values that have
122                          platform-specific  meanings;  the  interpretation of
123                          those fields is determined  by  the  value  of  this
124                          byte.  For example:
125
126                          ELFOSABI_NONE        Same as ELFOSABI_SYSV
127                          ELFOSABI_SYSV        UNIX System V ABI
128                          ELFOSABI_HPUX        HP-UX ABI
129                          ELFOSABI_NETBSD      NetBSD ABI
130                          ELFOSABI_LINUX       Linux ABI
131                          ELFOSABI_SOLARIS     Solaris ABI
132                          ELFOSABI_IRIX        IRIX ABI
133                          ELFOSABI_FREEBSD     FreeBSD ABI
134                          ELFOSABI_TRU64       TRU64 UNIX ABI
135                          ELFOSABI_ARM         ARM architecture ABI
136                          ELFOSABI_STANDALONE  Stand-alone (embedded) ABI
137
138                 EI_ABIVERSION
139                          The  ninth byte identifies the version of the ABI to
140                          which the object is targeted.  This field is used to
141                          distinguish  among  incompatible versions of an ABI.
142                          The interpretation of this version number is  depen‐
143                          dent  on  the  ABI identified by the EI_OSABI field.
144                          Applications conforming to  this  specification  use
145                          the value 0.
146
147                 EI_PAD   Start  of padding.  These bytes are reserved and set
148                          to zero.  Programs which  read  them  should  ignore
149                          them.   The  value  for  EI_PAD  will  change in the
150                          future if currently unused bytes are given meanings.
151
152                 EI_NIDENT
153                          The size of the e_ident array.
154
155       e_type    This member of the structure identifies the object file type:
156
157                 ET_NONE         An unknown type.
158                 ET_REL          A relocatable file.
159                 ET_EXEC         An executable file.
160                 ET_DYN          A shared object.
161                 ET_CORE         A core file.
162
163       e_machine This member specifies the required architecture for an  indi‐
164                 vidual file.  For example:
165
166                 EM_NONE         An unknown machine
167                 EM_M32          AT&T WE 32100
168                 EM_SPARC        Sun Microsystems SPARC
169                 EM_386          Intel 80386
170                 EM_68K          Motorola 68000
171                 EM_88K          Motorola 88000
172                 EM_860          Intel 80860
173                 EM_MIPS         MIPS RS3000 (big-endian only)
174                 EM_PARISC       HP/PA
175                 EM_SPARC32PLUS  SPARC with enhanced instruction set
176                 EM_PPC          PowerPC
177                 EM_PPC64        PowerPC 64-bit
178                 EM_S390         IBM S/390
179                 EM_ARM          Advanced RISC Machines
180                 EM_SH           Renesas SuperH
181                 EM_SPARCV9      SPARC v9 64-bit
182                 EM_IA_64        Intel Itanium
183                 EM_X86_64       AMD x86-64
184                 EM_VAX          DEC Vax
185
186       e_version This member identifies the file version:
187
188                 EV_NONE         Invalid version
189                 EV_CURRENT      Current version
190
191       e_entry   This  member  gives  the  virtual address to which the system
192                 first transfers control, thus starting the process.   If  the
193                 file has no associated entry point, this member holds zero.
194
195       e_phoff   This  member  holds the program header table's file offset in
196                 bytes.  If the file has no program header table, this  member
197                 holds zero.
198
199       e_shoff   This  member  holds the section header table's file offset in
200                 bytes.  If the file has no section header table, this  member
201                 holds zero.
202
203       e_flags   This  member  holds  processor-specific flags associated with
204                 the file.  Flag names take the form EF_`machine_flag'.   Cur‐
205                 rently, no flags have been defined.
206
207       e_ehsize  This member holds the ELF header's size in bytes.
208
209       e_phentsize
210                 This  member  holds  the  size  in  bytes of one entry in the
211                 file's program header table; all entries are the same size.
212
213       e_phnum   This member holds the number of entries in the program header
214                 table.  Thus the product of e_phentsize and e_phnum gives the
215                 table's size in bytes.  If a  file  has  no  program  header,
216                 e_phnum holds the value zero.
217
218                 If  the  number  of  entries  in  the program header table is
219                 larger than or equal to PN_XNUM (0xffff), this  member  holds
220                 PN_XNUM  (0xffff)  and the real number of entries in the pro‐
221                 gram header table is held in the sh_info member of  the  ini‐
222                 tial  entry  in section header table.  Otherwise, the sh_info
223                 member of the initial entry contains the value zero.
224
225                 PN_XNUM  This  is  defined  as  0xffff,  the  largest  number
226                          e_phnum can have, specifying where the actual number
227                          of program headers is assigned.
228
229       e_shentsize
230                 This member holds a sections header's size in bytes.  A  sec‐
231                 tion  header  is  one  entry in the section header table; all
232                 entries are the same size.
233
234       e_shnum   This member holds the number of entries in the section header
235                 table.  Thus the product of e_shentsize and e_shnum gives the
236                 section header table's size in bytes.  If a file has no  sec‐
237                 tion header table, e_shnum holds the value of zero.
238
239                 If  the  number  of  entries  in  the section header table is
240                 larger than or equal to SHN_LORESERVE (0xff00), e_shnum holds
241                 the  value zero and the real number of entries in the section
242                 header table is held in the sh_size  member  of  the  initial
243                 entry in section header table.  Otherwise, the sh_size member
244                 of the initial entry in the section header  table  holds  the
245                 value zero.
246
247       e_shstrndx
248                 This member holds the section header table index of the entry
249                 associated with the section name string table.  If  the  file
250                 has no section name string table, this member holds the value
251                 SHN_UNDEF.
252
253                 If the index of section name string table section  is  larger
254                 than  or  equal  to SHN_LORESERVE (0xff00), this member holds
255                 SHN_XINDEX (0xffff) and the real index of  the  section  name
256                 string  table  section  is  held in the sh_link member of the
257                 initial  entry  in  section  header  table.   Otherwise,  the
258                 sh_link  member  of the initial entry in section header table
259                 contains the value zero.
260
261   Program header (Phdr)
262       An executable or shared object file's program header table is an  array
263       of  structures, each describing a segment or other information the sys‐
264       tem needs to prepare the program for execution.  An object file segment
265       contains one or more sections.  Program headers are meaningful only for
266       executable and shared object files.  A file specifies its  own  program
267       header size with the ELF header's e_phentsize and e_phnum members.  The
268       ELF program header is described by the type  Elf32_Phdr  or  Elf64_Phdr
269       depending on the architecture:
270
271           typedef struct {
272               uint32_t   p_type;
273               Elf32_Off  p_offset;
274               Elf32_Addr p_vaddr;
275               Elf32_Addr p_paddr;
276               uint32_t   p_filesz;
277               uint32_t   p_memsz;
278               uint32_t   p_flags;
279               uint32_t   p_align;
280           } Elf32_Phdr;
281
282           typedef struct {
283               uint32_t   p_type;
284               uint32_t   p_flags;
285               Elf64_Off  p_offset;
286               Elf64_Addr p_vaddr;
287               Elf64_Addr p_paddr;
288               uint64_t   p_filesz;
289               uint64_t   p_memsz;
290               uint64_t   p_align;
291           } Elf64_Phdr;
292
293       The  main  difference  between the 32-bit and the 64-bit program header
294       lies in the location of the p_flags member in the total struct.
295
296       p_type    This member of the structure indicates what kind  of  segment
297                 this  array  element  describes or how to interpret the array
298                 element's information.
299
300                 PT_NULL     The array element is unused and  the  other  mem‐
301                             bers'  values  are undefined.  This lets the pro‐
302                             gram header have ignored entries.
303
304                 PT_LOAD     The array element specifies a  loadable  segment,
305                             described  by  p_filesz  and  p_memsz.  The bytes
306                             from the file are mapped to the beginning of  the
307                             memory  segment.   If  the  segment's memory size
308                             p_memsz is larger than the  file  size  p_filesz,
309                             the "extra" bytes are defined to hold the value 0
310                             and to follow  the  segment's  initialized  area.
311                             The  file  size may not be larger than the memory
312                             size.  Loadable segment entries  in  the  program
313                             header table appear in ascending order, sorted on
314                             the p_vaddr member.
315
316                 PT_DYNAMIC  The  array  element  specifies  dynamic   linking
317                             information.
318
319                 PT_INTERP   The array element specifies the location and size
320                             of a null-terminated pathname  to  invoke  as  an
321                             interpreter.   This  segment  type  is meaningful
322                             only for executable files (though  it  may  occur
323                             for  shared  objects).   However it may not occur
324                             more than once in a file.  If it is  present,  it
325                             must precede any loadable segment entry.
326
327                 PT_NOTE     The array element specifies the location of notes
328                             (ElfN_Nhdr).
329
330                 PT_SHLIB    This segment type is reserved but has unspecified
331                             semantics.   Programs  that contain an array ele‐
332                             ment of this type do not conform to the ABI.
333
334                 PT_PHDR     The array  element,  if  present,  specifies  the
335                             location  and  size  of  the program header table
336                             itself, both in the file and in the memory  image
337                             of  the program.  This segment type may not occur
338                             more than once in a file.  Moreover, it may occur
339                             only  if  the program header table is part of the
340                             memory image of the program.  If it  is  present,
341                             it must precede any loadable segment entry.
342
343                 PT_LOPROC, PT_HIPROC
344                             Values   in   the   inclusive  range  [PT_LOPROC,
345                             PT_HIPROC] are  reserved  for  processor-specific
346                             semantics.
347
348                 PT_GNU_STACK
349                             GNU  extension  which is used by the Linux kernel
350                             to control the state of the stack via  the  flags
351                             set in the p_flags member.
352
353       p_offset  This  member  holds the offset from the beginning of the file
354                 at which the first byte of the segment resides.
355
356       p_vaddr   This member holds the virtual address at which the first byte
357                 of the segment resides in memory.
358
359       p_paddr   On  systems  for  which physical addressing is relevant, this
360                 member is reserved for the segment's physical address.  Under
361                 BSD this member is not used and must be zero.
362
363       p_filesz  This  member  holds  the number of bytes in the file image of
364                 the segment.  It may be zero.
365
366       p_memsz   This member holds the number of bytes in the memory image  of
367                 the segment.  It may be zero.
368
369       p_flags   This  member  holds  a bit mask of flags relevant to the seg‐
370                 ment:
371
372                 PF_X   An executable segment.
373                 PF_W   A writable segment.
374                 PF_R   A readable segment.
375
376                 A text segment commonly has the flags PF_X and PF_R.  A  data
377                 segment commonly has PF_W and PF_R.
378
379       p_align   This member holds the value to which the segments are aligned
380                 in memory and in the file.  Loadable  process  segments  must
381                 have  congruent  values  for p_vaddr and p_offset, modulo the
382                 page size.  Values of zero  and  one  mean  no  alignment  is
383                 required.   Otherwise, p_align should be a positive, integral
384                 power of two,  and  p_vaddr  should  equal  p_offset,  modulo
385                 p_align.
386
387   Section header (Shdr)
388       A  file's section header table lets one locate all the file's sections.
389       The section header table is an array of Elf32_Shdr or Elf64_Shdr struc‐
390       tures.   The ELF header's e_shoff member gives the byte offset from the
391       beginning of the file to the section header table.  e_shnum  holds  the
392       number of entries the section header table contains.  e_shentsize holds
393       the size in bytes of each entry.
394
395       A section header table index is a subscript into this array.  Some sec‐
396       tion  header  table  indices  are  reserved:  the initial entry and the
397       indices between SHN_LORESERVE and SHN_HIRESERVE.  The initial entry  is
398       used  in  ELF  extensions  for  e_phnum, e_shnum and e_strndx; in other
399       cases, each field in the initial entry is set to zero.  An object  file
400       does not have sections for these special indices:
401
402       SHN_UNDEF
403              This value marks an undefined, missing, irrelevant, or otherwise
404              meaningless section reference.
405
406       SHN_LORESERVE
407              This value specifies the lower bound of the  range  of  reserved
408              indices.
409
410       SHN_LOPROC, SHN_HIPROC
411              Values  greater  in the inclusive range [SHN_LOPROC, SHN_HIPROC]
412              are reserved for processor-specific semantics.
413
414       SHN_ABS
415              This value specifies the absolute value  for  the  corresponding
416              reference.   For  example,  a symbol defined relative to section
417              number SHN_ABS has an absolute value  and  is  not  affected  by
418              relocation.
419
420       SHN_COMMON
421              Symbols  defined  relative  to  this section are common symbols,
422              such as FORTRAN COMMON or unallocated C external variables.
423
424       SHN_HIRESERVE
425              This value specifies the upper bound of the  range  of  reserved
426              indices.   The system reserves indices between SHN_LORESERVE and
427              SHN_HIRESERVE, inclusive.  The section  header  table  does  not
428              contain entries for the reserved indices.
429
430       The section header has the following structure:
431
432           typedef struct {
433               uint32_t   sh_name;
434               uint32_t   sh_type;
435               uint32_t   sh_flags;
436               Elf32_Addr sh_addr;
437               Elf32_Off  sh_offset;
438               uint32_t   sh_size;
439               uint32_t   sh_link;
440               uint32_t   sh_info;
441               uint32_t   sh_addralign;
442               uint32_t   sh_entsize;
443           } Elf32_Shdr;
444
445           typedef struct {
446               uint32_t   sh_name;
447               uint32_t   sh_type;
448               uint64_t   sh_flags;
449               Elf64_Addr sh_addr;
450               Elf64_Off  sh_offset;
451               uint64_t   sh_size;
452               uint32_t   sh_link;
453               uint32_t   sh_info;
454               uint64_t   sh_addralign;
455               uint64_t   sh_entsize;
456           } Elf64_Shdr;
457
458       No  real  differences exist between the 32-bit and 64-bit section head‐
459       ers.
460
461       sh_name   This member specifies the name of the section.  Its value  is
462                 an index into the section header string table section, giving
463                 the location of a null-terminated string.
464
465       sh_type   This member categorizes the section's contents and semantics.
466
467                 SHT_NULL       This value marks the section header  as  inac‐
468                                tive.  It does not have an associated section.
469                                Other members of the section header have unde‐
470                                fined values.
471
472                 SHT_PROGBITS   This  section holds information defined by the
473                                program, whose format and meaning  are  deter‐
474                                mined solely by the program.
475
476                 SHT_SYMTAB     This section holds a symbol table.  Typically,
477                                SHT_SYMTAB provides symbols for link  editing,
478                                though  it  may also be used for dynamic link‐
479                                ing.  As a complete symbol table, it may  con‐
480                                tain  many  symbols  unnecessary  for  dynamic
481                                linking.  An object file can  also  contain  a
482                                SHT_DYNSYM section.
483
484                 SHT_STRTAB     This  section holds a string table.  An object
485                                file may have multiple string table sections.
486
487                 SHT_RELA       This section  holds  relocation  entries  with
488                                explicit  addends, such as type Elf32_Rela for
489                                the 32-bit class of object files.   An  object
490                                may have multiple relocation sections.
491
492                 SHT_HASH       This  section  holds  a symbol hash table.  An
493                                object participating in dynamic  linking  must
494                                contain  a  symbol hash table.  An object file
495                                may have only one hash table.
496
497                 SHT_DYNAMIC    This section  holds  information  for  dynamic
498                                linking.   An  object  file  may have only one
499                                dynamic section.
500
501                 SHT_NOTE       This section holds notes (ElfN_Nhdr).
502
503                 SHT_NOBITS     A section of this type occupies  no  space  in
504                                the file but otherwise resembles SHT_PROGBITS.
505                                Although this section contains no  bytes,  the
506                                sh_offset  member contains the conceptual file
507                                offset.
508
509                 SHT_REL        This section holds relocation offsets  without
510                                explicit  addends,  such as type Elf32_Rel for
511                                the 32-bit class of object files.   An  object
512                                file may have multiple relocation sections.
513
514                 SHT_SHLIB      This  section  is reserved but has unspecified
515                                semantics.
516
517                 SHT_DYNSYM     This section holds a minimal  set  of  dynamic
518                                linking symbols.  An object file can also con‐
519                                tain a SHT_SYMTAB section.
520
521                 SHT_LOPROC, SHT_HIPROC
522                                Values in  the  inclusive  range  [SHT_LOPROC,
523                                SHT_HIPROC]  are  reserved  for processor-spe‐
524                                cific semantics.
525
526                 SHT_LOUSER     This value specifies the lower  bound  of  the
527                                range of indices reserved for application pro‐
528                                grams.
529
530                 SHT_HIUSER     This value specifies the upper  bound  of  the
531                                range of indices reserved for application pro‐
532                                grams.  Section types between  SHT_LOUSER  and
533                                SHT_HIUSER  may  be  used  by the application,
534                                without conflicting  with  current  or  future
535                                system-defined section types.
536
537       sh_flags  Sections  support  one-bit  flags that describe miscellaneous
538                 attributes.  If a flag bit is set in sh_flags, the  attribute
539                 is  "on"  for the section.  Otherwise, the attribute is "off"
540                 or does not apply.  Undefined attributes are set to zero.
541
542                 SHF_WRITE      This section  contains  data  that  should  be
543                                writable during process execution.
544
545                 SHF_ALLOC      This  section  occupies  memory during process
546                                execution.   Some  control  sections  do   not
547                                reside  in the memory image of an object file.
548                                This attribute is off for those sections.
549
550                 SHF_EXECINSTR  This  section  contains   executable   machine
551                                instructions.
552
553                 SHF_MASKPROC   All  bits  included  in this mask are reserved
554                                for processor-specific semantics.
555
556       sh_addr   If this section appears in the memory  image  of  a  process,
557                 this  member  holds  the address at which the section's first
558                 byte should reside.  Otherwise, the member contains zero.
559
560       sh_offset This member's value holds the byte offset from the  beginning
561                 of  the  file  to the first byte in the section.  One section
562                 type, SHT_NOBITS, occupies no space  in  the  file,  and  its
563                 sh_offset  member  locates  the  conceptual  placement in the
564                 file.
565
566       sh_size   This member holds the section's size in  bytes.   Unless  the
567                 section  type  is  SHT_NOBITS,  the  section occupies sh_size
568                 bytes in the file.  A section of type SHT_NOBITS may  have  a
569                 nonzero size, but it occupies no space in the file.
570
571       sh_link   This  member  holds  a section header table index link, whose
572                 interpretation depends on the section type.
573
574       sh_info   This member holds  extra  information,  whose  interpretation
575                 depends on the section type.
576
577       sh_addralign
578                 Some  sections have address alignment constraints.  If a sec‐
579                 tion holds a doubleword, the system  must  ensure  doubleword
580                 alignment  for  the  entire  section.   That is, the value of
581                 sh_addr must be  congruent  to  zero,  modulo  the  value  of
582                 sh_addralign.   Only zero and positive integral powers of two
583                 are allowed.  The value 0 or 1 means that the section has  no
584                 alignment constraints.
585
586       sh_entsize
587                 Some  sections hold a table of fixed-sized entries, such as a
588                 symbol table.  For such a section, this member gives the size
589                 in  bytes  for  each entry.  This member contains zero if the
590                 section does not hold a table of fixed-size entries.
591
592       Various sections hold program and control information:
593
594       .bss      This section holds uninitialized data that contributes to the
595                 program's  memory  image.  By definition, the system initial‐
596                 izes the data with zeros when  the  program  begins  to  run.
597                 This  section is of type SHT_NOBITS.  The attribute types are
598                 SHF_ALLOC and SHF_WRITE.
599
600       .comment  This section holds version control information.  This section
601                 is of type SHT_PROGBITS.  No attribute types are used.
602
603       .ctors    This  section holds initialized pointers to the C++ construc‐
604                 tor functions.  This section is of  type  SHT_PROGBITS.   The
605                 attribute types are SHF_ALLOC and SHF_WRITE.
606
607       .data     This  section  holds  initialized data that contribute to the
608                 program's memory image.  This section is  of  type  SHT_PROG‐
609                 BITS.  The attribute types are SHF_ALLOC and SHF_WRITE.
610
611       .data1    This  section  holds  initialized data that contribute to the
612                 program's memory image.  This section is  of  type  SHT_PROG‐
613                 BITS.  The attribute types are SHF_ALLOC and SHF_WRITE.
614
615       .debug    This  section  holds information for symbolic debugging.  The
616                 contents are unspecified.  This section is of type  SHT_PROG‐
617                 BITS.  No attribute types are used.
618
619       .dtors    This section holds initialized pointers to the C++ destructor
620                 functions.   This  section  is  of  type  SHT_PROGBITS.   The
621                 attribute types are SHF_ALLOC and SHF_WRITE.
622
623       .dynamic  This  section  holds  dynamic  linking information.  The sec‐
624                 tion's attributes will include the  SHF_ALLOC  bit.   Whether
625                 the SHF_WRITE bit is set is processor-specific.  This section
626                 is of type SHT_DYNAMIC.  See the attributes above.
627
628       .dynstr   This section holds strings needed for dynamic  linking,  most
629                 commonly the strings that represent the names associated with
630                 symbol table entries.  This section is  of  type  SHT_STRTAB.
631                 The attribute type used is SHF_ALLOC.
632
633       .dynsym   This  section  holds  the dynamic linking symbol table.  This
634                 section  is  of  type  SHT_DYNSYM.   The  attribute  used  is
635                 SHF_ALLOC.
636
637       .fini     This section holds executable instructions that contribute to
638                 the process termination code.  When a program exits  normally
639                 the  system  arranges  to  execute  the code in this section.
640                 This section is of type SHT_PROGBITS.   The  attributes  used
641                 are SHF_ALLOC and SHF_EXECINSTR.
642
643       .gnu.version
644                 This  section  holds  the  version  symbol table, an array of
645                 ElfN_Half elements.  This section is of type  SHT_GNU_versym.
646                 The attribute type used is SHF_ALLOC.
647
648       .gnu.version_d
649                 This section holds the version symbol definitions, a table of
650                 ElfN_Verdef   structures.    This   section   is   of    type
651                 SHT_GNU_verdef.  The attribute type used is SHF_ALLOC.
652
653       .gnu.version_r
654                 This  section holds the version symbol needed elements, a ta‐
655                 ble of ElfN_Verneed structures.   This  section  is  of  type
656                 SHT_GNU_versym.  The attribute type used is SHF_ALLOC.
657
658       .got      This  section holds the global offset table.  This section is
659                 of type SHT_PROGBITS.  The attributes are processor-specific.
660
661       .hash     This section holds a symbol hash table.  This section  is  of
662                 type SHT_HASH.  The attribute used is SHF_ALLOC.
663
664       .init     This section holds executable instructions that contribute to
665                 the process initialization code.  When a  program  starts  to
666                 run  the  system arranges to execute the code in this section
667                 before calling the main program entry point.  This section is
668                 of  type SHT_PROGBITS.  The attributes used are SHF_ALLOC and
669                 SHF_EXECINSTR.
670
671       .interp   This section holds the pathname of a program interpreter.  If
672                 the  file  has  a loadable segment that includes the section,
673                 the section's attributes  will  include  the  SHF_ALLOC  bit.
674                 Otherwise,  that  bit  will  be off.  This section is of type
675                 SHT_PROGBITS.
676
677       .line     This section  holds  line  number  information  for  symbolic
678                 debugging,  which  describes  the  correspondence between the
679                 program source  and  the  machine  code.   The  contents  are
680                 unspecified.   This  section  is  of  type  SHT_PROGBITS.  No
681                 attribute types are used.
682
683       .note     This section holds various notes.  This section  is  of  type
684                 SHT_NOTE.  No attribute types are used.
685
686       .note.ABI-tag
687                 This  section is used to declare the expected run-time ABI of
688                 the ELF image.  It may include the operating system name  and
689                 its  run-time  versions.   This  section is of type SHT_NOTE.
690                 The only attribute used is SHF_ALLOC.
691
692       .note.gnu.build-id
693                 This section is used to hold an ID that  uniquely  identifies
694                 the contents of the ELF image.  Different files with the same
695                 build ID should contain the same executable content.  See the
696                 --build-id  option  to  the  GNU  linker  (ld  (1))  for more
697                 details.   This  section  is  of  type  SHT_NOTE.   The  only
698                 attribute used is SHF_ALLOC.
699
700       .note.GNU-stack
701                 This  section  is  used  in  Linux object files for declaring
702                 stack attributes.  This section is of type SHT_PROGBITS.  The
703                 only  attribute used is SHF_EXECINSTR.  This indicates to the
704                 GNU linker that the object file requires an executable stack.
705
706       .note.openbsd.ident
707                 OpenBSD native executables usually contain  this  section  to
708                 identify  themselves so the kernel can bypass any compatibil‐
709                 ity ELF binary emulation tests when loading the file.
710
711       .plt      This section holds the procedure linkage table.  This section
712                 is  of  type SHT_PROGBITS.  The attributes are processor-spe‐
713                 cific.
714
715       .relNAME  This section holds relocation information as described below.
716                 If  the file has a loadable segment that includes relocation,
717                 the section's attributes  will  include  the  SHF_ALLOC  bit.
718                 Otherwise,  the  bit  will  be off.  By convention, "NAME" is
719                 supplied by the section to which the relocations apply.  Thus
720                 a  relocation  section for .text normally would have the name
721                 .rel.text.  This section is of type SHT_REL.
722
723       .relaNAME This section holds relocation information as described below.
724                 If  the file has a loadable segment that includes relocation,
725                 the section's attributes  will  include  the  SHF_ALLOC  bit.
726                 Otherwise,  the  bit  will  be off.  By convention, "NAME" is
727                 supplied by the section to which the relocations apply.  Thus
728                 a  relocation  section for .text normally would have the name
729                 .rela.text.  This section is of type SHT_RELA.
730
731       .rodata   This section holds read-only data that typically  contributes
732                 to  a nonwritable segment in the process image.  This section
733                 is of type SHT_PROGBITS.  The attribute used is SHF_ALLOC.
734
735       .rodata1  This section holds read-only data that typically  contributes
736                 to  a nonwritable segment in the process image.  This section
737                 is of type SHT_PROGBITS.  The attribute used is SHF_ALLOC.
738
739       .shstrtab This section holds section names.  This section  is  of  type
740                 SHT_STRTAB.  No attribute types are used.
741
742       .strtab   This  section  holds  strings, most commonly the strings that
743                 represent the names associated with symbol table entries.  If
744                 the  file  has  a  loadable  segment that includes the symbol
745                 string table,  the  section's  attributes  will  include  the
746                 SHF_ALLOC bit.  Otherwise, the bit will be off.  This section
747                 is of type SHT_STRTAB.
748
749       .symtab   This section holds a symbol table.  If the file has  a  load‐
750                 able  segment  that  includes the symbol table, the section's
751                 attributes will include the SHF_ALLOC  bit.   Otherwise,  the
752                 bit will be off.  This section is of type SHT_SYMTAB.
753
754       .text     This section holds the "text", or executable instructions, of
755                 a program.   This  section  is  of  type  SHT_PROGBITS.   The
756                 attributes used are SHF_ALLOC and SHF_EXECINSTR.
757
758   String and symbol tables
759       String  table  sections  hold null-terminated character sequences, com‐
760       monly called strings.  The object file uses these strings to  represent
761       symbol and section names.  One references a string as an index into the
762       string table section.  The first byte, which is index zero, is  defined
763       to  hold  a null byte ('\0').  Similarly, a string table's last byte is
764       defined to hold a null byte, ensuring null termination for all strings.
765
766       An object file's symbol table holds information needed  to  locate  and
767       relocate a program's symbolic definitions and references.  A symbol ta‐
768       ble index is a subscript into this array.
769
770           typedef struct {
771               uint32_t      st_name;
772               Elf32_Addr    st_value;
773               uint32_t      st_size;
774               unsigned char st_info;
775               unsigned char st_other;
776               uint16_t      st_shndx;
777           } Elf32_Sym;
778
779           typedef struct {
780               uint32_t      st_name;
781               unsigned char st_info;
782               unsigned char st_other;
783               uint16_t      st_shndx;
784               Elf64_Addr    st_value;
785               uint64_t      st_size;
786           } Elf64_Sym;
787
788       The 32-bit and 64-bit versions have the same members, just in a differ‐
789       ent order.
790
791       st_name   This  member  holds  an  index  into the object file's symbol
792                 string table, which holds character  representations  of  the
793                 symbol  names.   If  the  value  is  nonzero, it represents a
794                 string table index that gives the  symbol  name.   Otherwise,
795                 the symbol has no name.
796
797       st_value  This member gives the value of the associated symbol.
798
799       st_size   Many  symbols  have associated sizes.  This member holds zero
800                 if the symbol has no size or an unknown size.
801
802       st_info   This  member  specifies  the  symbol's   type   and   binding
803                 attributes:
804
805                 STT_NOTYPE  The symbol's type is not defined.
806
807                 STT_OBJECT  The symbol is associated with a data object.
808
809                 STT_FUNC    The symbol is associated with a function or other
810                             executable code.
811
812                 STT_SECTION The symbol is associated with a section.   Symbol
813                             table  entries  of  this type exist primarily for
814                             relocation and normally have STB_LOCAL bindings.
815
816                 STT_FILE    By convention, the symbol's name gives  the  name
817                             of  the  source  file  associated with the object
818                             file.  A file symbol has STB_LOCAL bindings,  its
819                             section  index  is  SHN_ABS,  and it precedes the
820                             other STB_LOCAL symbols of the  file,  if  it  is
821                             present.
822
823                 STT_LOPROC, STT_HIPROC
824                             Values   in   the  inclusive  range  [STT_LOPROC,
825                             STT_HIPROC] are reserved  for  processor-specific
826                             semantics.
827
828                 STB_LOCAL   Local  symbols are not visible outside the object
829                             file containing their definition.  Local  symbols
830                             of  the  same  name  may  exist in multiple files
831                             without interfering with each other.
832
833                 STB_GLOBAL  Global symbols are visible to  all  object  files
834                             being  combined.   One  file's  definition  of  a
835                             global symbol will satisfy another  file's  unde‐
836                             fined reference to the same symbol.
837
838                 STB_WEAK    Weak  symbols  resemble global symbols, but their
839                             definitions have lower precedence.
840
841                 STB_LOPROC, STB_HIPROC
842                             Values  in  the  inclusive   range   [STB_LOPROC,
843                             STB_HIPROC]  are  reserved for processor-specific
844                             semantics.
845
846                 There are macros for packing and unpacking  the  binding  and
847                 type fields:
848
849                 ELF32_ST_BIND(info), ELF64_ST_BIND(info)
850                        Extract a binding from an st_info value.
851
852                 ELF32_ST_TYPE(info), ELF64_ST_TYPE(info)
853                        Extract a type from an st_info value.
854
855                 ELF32_ST_INFO(bind, type), ELF64_ST_INFO(bind, type)
856                        Convert a binding and a type into an st_info value.
857
858       st_other  This member defines the symbol visibility.
859
860                 STV_DEFAULT     Default  symbol visibility rules.  Global and
861                                 weak symbols are available to other  modules;
862                                 references  in the local module can be inter‐
863                                 posed by definitions in other modules.
864                 STV_INTERNAL    Processor-specific hidden class.
865                 STV_HIDDEN      Symbol is unavailable to other modules;  ref‐
866                                 erences in the local module always resolve to
867                                 the local symbol (i.e., the symbol  can't  be
868                                 interposed by definitions in other modules).
869                 STV_PROTECTED   Symbol  is  available  to  other modules, but
870                                 references in the local module always resolve
871                                 to the local symbol.
872
873                 There are macros for extracting the visibility type:
874
875                 ELF32_ST_VISIBILITY(other) or ELF64_ST_VISIBILITY(other)
876
877       st_shndx  Every  symbol  table  entry  is "defined" in relation to some
878                 section.  This member holds the relevant section header table
879                 index.
880
881   Relocation entries (Rel & Rela)
882       Relocation  is  the process of connecting symbolic references with sym‐
883       bolic  definitions.   Relocatable  files  must  have  information  that
884       describes  how  to  modify  their  section contents, thus allowing exe‐
885       cutable and shared object files to hold the  right  information  for  a
886       process's program image.  Relocation entries are these data.
887
888       Relocation structures that do not need an addend:
889
890           typedef struct {
891               Elf32_Addr r_offset;
892               uint32_t   r_info;
893           } Elf32_Rel;
894
895           typedef struct {
896               Elf64_Addr r_offset;
897               uint64_t   r_info;
898           } Elf64_Rel;
899
900       Relocation structures that need an addend:
901
902           typedef struct {
903               Elf32_Addr r_offset;
904               uint32_t   r_info;
905               int32_t    r_addend;
906           } Elf32_Rela;
907
908           typedef struct {
909               Elf64_Addr r_offset;
910               uint64_t   r_info;
911               int64_t    r_addend;
912           } Elf64_Rela;
913
914       r_offset  This  member gives the location at which to apply the reloca‐
915                 tion action.  For a relocatable file, the value is  the  byte
916                 offset  from the beginning of the section to the storage unit
917                 affected by the relocation.  For an executable file or shared
918                 object,  the value is the virtual address of the storage unit
919                 affected by the relocation.
920
921       r_info    This member gives both the symbol table index with respect to
922                 which  the relocation must be made and the type of relocation
923                 to apply.  Relocation types are processor-specific.  When the
924                 text refers to a relocation entry's relocation type or symbol
925                 table   index,   it   means   the    result    of    applying
926                 ELF[32|64]_R_TYPE  or  ELF[32|64]_R_SYM, respectively, to the
927                 entry's r_info member.
928
929       r_addend  This member specifies a constant addend used to  compute  the
930                 value to be stored into the relocatable field.
931
932   Dynamic tags (Dyn)
933       The .dynamic section contains a series of structures that hold relevant
934       dynamic linking information.  The d_tag member controls the interpreta‐
935       tion of d_un.
936
937           typedef struct {
938               Elf32_Sword    d_tag;
939               union {
940                   Elf32_Word d_val;
941                   Elf32_Addr d_ptr;
942               } d_un;
943           } Elf32_Dyn;
944           extern Elf32_Dyn _DYNAMIC[];
945
946           typedef struct {
947               Elf64_Sxword    d_tag;
948               union {
949                   Elf64_Xword d_val;
950                   Elf64_Addr  d_ptr;
951               } d_un;
952           } Elf64_Dyn;
953           extern Elf64_Dyn _DYNAMIC[];
954
955       d_tag     This member may have any of the following values:
956
957                 DT_NULL     Marks end of dynamic section
958
959                 DT_NEEDED   String table offset to name of a needed library
960
961                 DT_PLTRELSZ Size in bytes of PLT relocation entries
962
963                 DT_PLTGOT   Address of PLT and/or GOT
964
965                 DT_HASH     Address of symbol hash table
966
967                 DT_STRTAB   Address of string table
968
969                 DT_SYMTAB   Address of symbol table
970
971                 DT_RELA     Address of Rela relocation table
972
973                 DT_RELASZ   Size in bytes of the Rela relocation table
974
975                 DT_RELAENT  Size in bytes of a Rela relocation table entry
976
977                 DT_STRSZ    Size in bytes of string table
978
979                 DT_SYMENT   Size in bytes of a symbol table entry
980
981                 DT_INIT     Address of the initialization function
982
983                 DT_FINI     Address of the termination function
984
985                 DT_SONAME   String table offset to name of shared object
986
987                 DT_RPATH    String  table offset to library search path (dep‐
988                             recated)
989
990                 DT_SYMBOLIC Alert linker to search this shared object  before
991                             the executable for symbols
992
993                 DT_REL      Address of Rel relocation table
994
995                 DT_RELSZ    Size in bytes of Rel relocation table
996
997                 DT_RELENT   Size in bytes of a Rel table entry
998
999                 DT_PLTREL   Type  of relocation entry to which the PLT refers
1000                             (Rela or Rel)
1001
1002                 DT_DEBUG    Undefined use for debugging
1003
1004                 DT_TEXTREL  Absence of this entry indicates that  no  reloca‐
1005                             tion  entries  should apply to a nonwritable seg‐
1006                             ment
1007
1008                 DT_JMPREL   Address of relocation entries  associated  solely
1009                             with the PLT
1010
1011                 DT_BIND_NOW Instruct  dynamic  linker  to process all reloca‐
1012                             tions before transferring  control  to  the  exe‐
1013                             cutable
1014
1015                 DT_RUNPATH  String table offset to library search path
1016
1017                 DT_LOPROC, DT_HIPROC
1018                             Values   in   the   inclusive  range  [DT_LOPROC,
1019                             DT_HIPROC] are  reserved  for  processor-specific
1020                             semantics
1021
1022       d_val     This  member represents integer values with various interpre‐
1023                 tations.
1024
1025       d_ptr     This  member  represents  program  virtual  addresses.   When
1026                 interpreting  these  addresses,  the actual address should be
1027                 computed based on the original file  value  and  memory  base
1028                 address.   Files  do  not contain relocation entries to fixup
1029                 these addresses.
1030
1031       _DYNAMIC  Array containing all the dynamic structures in  the  .dynamic
1032                 section.  This is automatically populated by the linker.
1033
1034   Notes (Nhdr)
1035       ELF  notes  allow for appending arbitrary information for the system to
1036       use.  They are largely used by core files (e_type of ET_CORE), but many
1037       projects define their own set of extensions.  For example, the GNU tool
1038       chain uses ELF notes to pass information  from  the  linker  to  the  C
1039       library.
1040
1041       Note  sections  contain  a  series of notes (see the struct definitions
1042       below).  Each note is followed by  the  name  field  (whose  length  is
1043       defined  in n_namesz) and then by the descriptor field (whose length is
1044       defined in n_descsz) and whose starting address has a 4 byte alignment.
1045       Neither  field  is  defined  in  the note struct due to their arbitrary
1046       lengths.
1047
1048       An example for parsing out two consecutive notes should  clarify  their
1049       layout in memory:
1050
1051           void *memory, *name, *desc;
1052           Elf64_Nhdr *note, *next_note;
1053
1054           /* The buffer is pointing to the start of the section/segment */
1055           note = memory;
1056
1057           /* If the name is defined, it follows the note */
1058           name = note->n_namesz == 0 ? NULL : memory + sizeof(*note);
1059
1060           /* If the descriptor is defined, it follows the name
1061              (with alignment) */
1062
1063           desc = note->n_descsz == 0 ? NULL :
1064                  memory + sizeof(*note) + ALIGN_UP(note->n_namesz, 4);
1065
1066           /* The next note follows both (with alignment) */
1067           next_note = memory + sizeof(*note) +
1068                                ALIGN_UP(note->n_namesz, 4) +
1069                                ALIGN_UP(note->n_descsz, 4);
1070
1071       Keep in mind that the interpretation of n_type depends on the namespace
1072       defined by the n_namesz field.  If the n_namesz field is not set (e.g.,
1073       is 0), then there are two sets of notes: one for core files and one for
1074       all other ELF types.  If the namespace is unknown, then tools will usu‐
1075       ally fallback to these sets of notes as well.
1076
1077           typedef struct {
1078               Elf32_Word n_namesz;
1079               Elf32_Word n_descsz;
1080               Elf32_Word n_type;
1081           } Elf32_Nhdr;
1082
1083           typedef struct {
1084               Elf64_Word n_namesz;
1085               Elf64_Word n_descsz;
1086               Elf64_Word n_type;
1087           } Elf64_Nhdr;
1088
1089       n_namesz  The  length  of  the  name field in bytes.  The contents will
1090                 immediately follow this note in memory.   The  name  is  null
1091                 terminated.  For example, if the name is "GNU", then n_namesz
1092                 will be set to 4.
1093
1094       n_descsz  The length of the descriptor field in  bytes.   The  contents
1095                 will immediately follow the name field in memory.
1096
1097       n_type    Depending  on  the  value  of the name field, this member may
1098                 have any of the following values:
1099
1100                 Core files (e_type = ET_CORE)
1101                      Notes used by all core files.  These are highly  operat‐
1102                      ing  system  or  architecture specific and often require
1103                      close coordination with kernels, C libraries, and debug‐
1104                      gers.   These are used when the namespace is the default
1105                      (i.e., n_namesz will be set to 0), or  a  fallback  when
1106                      the namespace is unknown.
1107
1108                      NT_PRSTATUS          prstatus struct
1109                      NT_FPREGSET          fpregset struct
1110                      NT_PRPSINFO          prpsinfo struct
1111                      NT_PRXREG            prxregset struct
1112                      NT_TASKSTRUCT        task structure
1113                      NT_PLATFORM          String from sysinfo(SI_PLATFORM)
1114                      NT_AUXV              auxv array
1115                      NT_GWINDOWS          gwindows struct
1116                      NT_ASRS              asrset struct
1117                      NT_PSTATUS           pstatus struct
1118                      NT_PSINFO            psinfo struct
1119                      NT_PRCRED            prcred struct
1120                      NT_UTSNAME           utsname struct
1121                      NT_LWPSTATUS         lwpstatus struct
1122                      NT_LWPSINFO          lwpinfo struct
1123                      NT_PRFPXREG          fprxregset struct
1124                      NT_SIGINFO           siginfo_t (size might increase over
1125                                           time)
1126                      NT_FILE              Contains information  about  mapped
1127                                           files
1128                      NT_PRXFPREG          user_fxsr_struct
1129                      NT_PPC_VMX           PowerPC Altivec/VMX registers
1130                      NT_PPC_SPE           PowerPC SPE/EVR registers
1131                      NT_PPC_VSX           PowerPC VSX registers
1132                      NT_386_TLS           i386 TLS slots (struct user_desc)
1133                      NT_386_IOPERM        x86 io permission bitmap (1=deny)
1134                      NT_X86_XSTATE        x86 extended state using xsave
1135                      NT_S390_HIGH_GPRS    s390 upper register halves
1136                      NT_S390_TIMER        s390 timer register
1137                      NT_S390_TODCMP       s390  time-of-day  (TOD) clock com‐
1138                                           parator register
1139                      NT_S390_TODPREG      s390 time-of-day (TOD) programmable
1140                                           register
1141                      NT_S390_CTRS         s390 control registers
1142                      NT_S390_PREFIX       s390 prefix register
1143                      NT_S390_LAST_BREAK   s390 breaking event address
1144                      NT_S390_SYSTEM_CALL  s390 system call restart data
1145                      NT_S390_TDB          s390 transaction diagnostic block
1146                      NT_ARM_VFP           ARM VFP/NEON registers
1147                      NT_ARM_TLS           ARM TLS register
1148                      NT_ARM_HW_BREAK      ARM hardware breakpoint registers
1149                      NT_ARM_HW_WATCH      ARM hardware watchpoint registers
1150                      NT_ARM_SYSTEM_CALL   ARM system call number
1151
1152                 n_name = GNU
1153                      Extensions used by the GNU tool chain.
1154
1155                      NT_GNU_ABI_TAG
1156                             Operating  system (OS) ABI information.  The desc
1157                             field will be 4 words:
1158
1159                             · word  0:  OS   descriptor   (ELF_NOTE_OS_LINUX,
1160                               ELF_NOTE_OS_GNU, and so on)`
1161                             · word 1: major version of the ABI
1162                             · word 2: minor version of the ABI
1163                             · word 3: subminor version of the ABI
1164
1165                      NT_GNU_HWCAP
1166                             Synthetic  hwcap  information.   The  desc  field
1167                             begins with two words:
1168
1169                             · word 0: number of entries
1170                             · word 1: bit mask of enabled entries
1171
1172                             Then follow  variable-length  entries,  one  byte
1173                             followed  by a null-terminated hwcap name string.
1174                             The byte gives the bit number to test if enabled,
1175                             (1U << bit) & bit mask.
1176
1177                      NT_GNU_BUILD_ID
1178                             Unique  build  ID  as  generated by the GNU ld(1)
1179                             --build-id option.   The  desc  consists  of  any
1180                             nonzero number of bytes.
1181
1182                      NT_GNU_GOLD_VERSION
1183                             The  desc  contains  the  GNU Gold linker version
1184                             used.
1185
1186                 Default/unknown namespace (e_type != ET_CORE)
1187                      These are used when the namespace is the default  (i.e.,
1188                      n_namesz  will  be  set  to  0),  or a fallback when the
1189                      namespace is unknown.
1190
1191                      NT_VERSION           A version string of some sort.
1192                      NT_ARCH              Architecture information.
1193

NOTES

1195       ELF first appeared in System V.  The ELF format is an adopted standard.
1196
1197       The extensions for e_phnum, e_shnum and e_strndx respectively are Linux
1198       extensions.  Sun, BSD and AMD64 also support them; for further informa‐
1199       tion, look under SEE ALSO.
1200

SEE ALSO

1202       as(1), elfedit(1), gdb(1), ld(1), nm(1), objdump(1), patchelf(1), read‐
1203       elf(1),  size(1),  strings(1), strip(1), execve(2), dl_iterate_phdr(3),
1204       core(5), ld.so(8)
1205
1206       Hewlett-Packard, Elf-64 Object File Format.
1207
1208       Santa Cruz Operation, System V Application Binary Interface.
1209
1210       UNIX System Laboratories, "Object Files", Executable and Linking Format
1211       (ELF).
1212
1213       Sun Microsystems, Linker and Libraries Guide.
1214
1215       AMD64  ABI Draft, System V Application Binary Interface AMD64 Architec‐
1216       ture Processor Supplement.
1217

COLOPHON

1219       This page is part of release 5.02 of the Linux  man-pages  project.   A
1220       description  of  the project, information about reporting bugs, and the
1221       latest    version    of    this    page,    can     be     found     at
1222       https://www.kernel.org/doc/man-pages/.
1223
1224
1225
1226Linux                             2019-05-09                            ELF(5)
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