diff options
Diffstat (limited to 'man5')
| -rw-r--r-- | man5/elf.5 | 154 |
1 files changed, 133 insertions, 21 deletions
diff --git a/man5/elf.5 b/man5/elf.5 index 7d96714579..11436dec62 100644 --- a/man5/elf.5 +++ b/man5/elf.5 @@ -26,12 +26,14 @@ .\" $FreeBSD: src/share/man/man5/elf.5,v 1.21 2001/10/01 16:09:23 ru Exp $ .\" .\" Slightly adapted - aeb, 2004-01-01 +.\" 2005-07-15, Mike Frysinger <vapier@gentoo.org>, various fixes +.\" .Dd July 31, 1999 .Dt ELF 5 .Os .Sh NAME .Nm elf -.Nd format of ELF executable binary files +.Nd format of Executable and Linking Format (ELF) files .Sh SYNOPSIS .\" .Fd #include <elf_abi.h> .Fd #include <elf.h> @@ -206,6 +208,9 @@ the interpretation of those fields is determined by the value of this byte. E.g.: .Pp .Bl -tag -width "ELFOSABI_STANDALONE" -compact +.It Dv ELFOSABI_NONE +Same as ELFOSABI_SYSV +.\" 0 .It Dv ELFOSABI_SYSV UNIX System V ABI. .\" 0 @@ -328,7 +333,7 @@ MIPS RS3000 (big-endian only). .\" EM_MIPS_RS3_LE (MIPS R3000 little-endian) .\" 10 .It Dv EM_PARISC -HPPA. +HP/PA. .\" 15 .It Dv EM_SPARC32PLUS SPARC with enhanced instruction set. @@ -336,18 +341,26 @@ SPARC with enhanced instruction set. .It Dv EM_PPC PowerPC. .\" 20 -.\" EM_PPC64 +.It Dv EM_PPC64 +PowerPC 64-bit. .\" 21 -.\" EM_S390 +.It Dv EM_S390 +IBM S/390 .\" 22 -.\" EM_SH +.It Dv EM_ARM +Advanced RISC Machines +.\" 40 +.It Dv EM_SH +Renesas SuperH .\" 42 .It Dv EM_SPARCV9 SPARC v9 64-bit. .\" 43 -.\" EM_IA_64 +.It Dv EM_IA_64 +Intel Itanium .\" 50 -.\" EM_X86_64 +.It Dv EM_X86_64 +AMD x86-64 .\" 62 .It Dv EM_VAX DEC Vax. @@ -714,7 +727,9 @@ typedef struct { uint64_t sh_entsize; } Elf64_Shdr; .Ed -.Bl -tag -width "sh_addralign" +.Pp +No real differences exist between the 32-bit and 64-bit section headers. +.Bl -tag -width "sh_addralign" -offset indent .It Dv sh_name This member specifies the name of the section. Its value is an index @@ -889,7 +904,7 @@ fixed-size entries. .El .Pp Various sections hold program and control information: -.Bl -tag -width ".shstrtab" +.Bl -tag -width ".shstrtab" -offset indent .It .bss This section holds uninitialized data that contributes to the program's memory image. @@ -1162,7 +1177,10 @@ typedef struct { uint64_t st_size; } Elf64_Sym; .Ed -.Bl -tag -width "st_value" +.Pp +The 32-bit and 64-bit versions have the same members, just in a different +order. +.Bl -tag -width "st_value" -offset indent .It Dv st_name This member holds an index into the object file's symbol string table, which holds character representations of the symbol names. @@ -1235,27 +1253,24 @@ is reserved for processor-specific semantics. .Pp There are macros for packing and unpacking the binding and type fields: .Pp -.Bl -tag -width "ELF32_ST_INFO(bind, type)" -compact -.It Xo +.Bl -tag -width "ELF_ST_INFO" -compact .Fn ELF32_ST_BIND info -.Xc or .Fn ELF64_ST_BIND info extract a binding from an st_info value. -.It Xo -.Fn ELF64_ST_TYPE info -.Xc -or +.Pp .Fn ELF32_ST_TYPE info +or +.Fn ELF64_ST_TYPE info +.br extract a type from an st_info value. -.It Xo +.Pp .Fn ELF32_ST_INFO bind type -.Xc or .Fn ELF64_ST_INFO bind type +.br convert a binding and a type into an st_info value. .El -.El .Pp .It Dv st_other This member currently holds zero and has no defined meaning. @@ -1304,7 +1319,7 @@ typedef struct { int64_t r_addend; } Elf64_Rela; .Ed -.Bl -tag -width "r_offset" +.Bl -tag -width "r_offset" -offset indent .It Dv r_offset This member gives the location at which to apply the relocation action. For a relocatable file, the value is the byte offset from the beginning @@ -1330,6 +1345,103 @@ member. This member specifies a constant addend used to compute the value to be stored into the relocatable field. .El +.Pp +The .dynamic section contains a series of structures that hold relevant +dynamic linking information. The d_tag member controls the interpretation +of d_un. +.Bd -literal -offset indent +typedef struct { + Elf32_Sword d_tag; + union { + Elf32_Word d_val; + Elf32_Addr d_ptr; + } d_un; +} Elf32_Dyn; +extern Elf32_Dyn _DYNAMIC[]; +.Ed +.Bd -literal -offset indent +typedef struct { + Elf64_Sxword d_tag; + union { + Elf64_Xword d_val; + Elf64_Addr d_ptr; + } d_un; +} Elf64_Dyn; +extern Elf64_Dyn _DYNAMIC[]; +.Ed +.Bl -tag -width "d_tag" -offset indent +.It Dv d_tag +This member may have any of the following values: +.Bl -tag -width "DT_SYMBOLIC" +.It Dv DT_NULL +Marks end of dynamic section +.It Dv DT_NEEDED +String table offset to name of a needed library +.It Dv DT_PLTRELSZ +Size in bytes of PLT relocs +.It Dv DT_PLTGOT +Address of PLT and/or GOT +.It Dv DT_HASH +Address of symbol hash table +.It Dv DT_STRTAB +Address of string table +.It Dv DT_SYMTAB +Address of symbol table +.It Dv DT_RELA +Address of Rela relocs table +.It Dv DT_RELASZ +Size in bytes of Rela table +.It Dv DT_RELAENT +Size in bytes of a Rela table entry +.It Dv DT_STRSZ +Size in bytes of string table +.It Dv DT_SYMENT +Size in bytes of a symbol table entry +.It Dv DT_INIT +Address of the initialization function +.It Dv DT_FINI +Address of the termination function +.It Dv DT_SONAME +String table offset to name of shared object +.It Dv DT_RPATH +String table offset to library search path (deprecated) +.It Dv DT_SYMBOLIC +Alert linker to search this shared object before the executable for symbols +.It Dv DT_REL +Address of Rel relocs table +.It Dv DT_RELSZ +Size in bytes of Rel table +.It Dv DT_RELENT +Size in bytes of a Rel table entry +.It Dv DT_PLTREL +Type of reloc the PLT refers (Rela or Rel) +.It Dv DT_DEBUG +Undefined use for debugging +.It Dv DT_TEXTREL +Absence of this indicates no relocs should apply to a non-writable segment +.It Dv DT_JMPREL +Address of reloc entries solely for the PLT +.It Dv DT_BIND_NOW +Instruct dynamic linker to process all relocs before transferring control to +the executable +.It Dv DT_RUNPATH +String table offset to library search path +.It Dv DT_LOPROC +Start of processor-specific semantics +.It Dv DT_HIPROC +End of processor-specific semantics +.El +.It Dv d_val +This member represents integer values with various interpretations. +.It Dv d_ptr +This member represents program virtual addresses. When interpreting +these addresses, the actual address should be computed based on the +original file value and memory base address. Files do not contain +relocation entries to fixup these addresses. +.It Dv _DYNAMIC +Array containing all the dynamic structures in the .dynamic section. +This is automatically populated by the linker. +.El .Sh SEE ALSO .Xr as 1 , .Xr gdb 1 , |