Executable and Linking Format (ELF)

Executable and Linking Format (ELF): https://de.wikipedia.org/wiki/Executable_and_Linking_Format (außerdem: a.out, COFF, COM, ECOFF, ELF, Hunk, Mach-O, MZ, NE, OMF, PE, PEF, XCOFF)

Das ELF-Binärformat: http://www.linux-kernel.de/appendix/ap05.pdf - Doku: Aufbau und Struktur, ELF-Header.

ELF Header: http://www.sco.com/developers/gabi/latest/ch4.eheader.html - mit ausführlicher Beschreibung von e_type, e_machine, EI_OSABI, etc.

Linux Programmer's Manual:

elf(5) - Header <elf.h>
readelf(1) - Displays information about ELF files.

Datentypen

<elf.h>

/* 32-bit ELF base types. */
typedef uint16_t	Elf32_Half;
typedef uint32_t	Elf32_Word;
typedef int32_t		Elf32_Sword;
typedef uint64_t	Elf32_Xword;
typedef int64_t		Elf32_Sxword;
typedef uint32_t	Elf32_Addr;
typedef uint32_t	Elf32_Off;
typedef uint16_t	Elf32_Section;
typedef Elf32_Half	Elf32_Versym;
 
/* 64-bit ELF base types. */
typedef uint16_t	Elf64_Half;
typedef uint32_t	Elf64_Word;
typedef int32_t		Elf64_Sword;
typedef uint64_t	Elf64_Xword;
typedef int64_t		Elf64_Sxword;
typedef uint64_t	Elf64_Addr;
typedef uint64_t	Elf64_Off;
typedef uint16_t	Elf64_Section;
typedef Elf64_Half	Elf64_Versym;

ELF-Header

(aus <elf.h>)

Auf 32-Bit-Architekturen:

#define EI_NIDENT 16
 
typedef struct elf32_hdr
{
	unsigned char	e_ident[EI_NIDENT];
	Elf32_Half	e_type;
	Elf32_Half	e_machine;
	Elf32_Word	e_version;
	Elf32_Addr	e_entry;	/* Entry point */
	Elf32_Off	e_phoff;
	Elf32_Off	e_shoff;
	Elf32_Word	e_flags;
	Elf32_Half	e_ehsize;
	Elf32_Half	e_phentsize;
	Elf32_Half	e_phnum;
	Elf32_Half	e_shentsize;
	Elf32_Half	e_shnum;
	Elf32_Half	e_shstrndx;
} Elf32_Ehdr;

Auf 64-Bit-Architekturen:

#define EI_NIDENT 16
 
typedef struct elf64_hdr
{
	unsigned char	e_ident[EI_NIDENT];	/* ELF magic number */
	Elf64_Half	e_type;
	Elf64_Half	e_machine;
	Elf64_Word	e_version;
	Elf64_Addr	e_entry;	/* Entry point virtual address */
	Elf64_Off	e_phoff;	/* Program header table file offset */
	Elf64_Off	e_shoff;	/* Section header table file offset */
	Elf64_Word	e_flags;
	Elf64_Half	e_ehsize;
	Elf64_Half	e_phentsize;
	Elf64_Half	e_phnum;
	Elf64_Half	e_shentsize;
	Elf64_Half	e_shnum;
	Elf64_Half	e_shstrndx;
} Elf64_Ehdr;

Weitere Infos

Redirecting functions in shared ELF libraries: http://www.codeproject.com/Articles/70302/Redirecting-functions-in-shared-ELF-libraries

Stand: 12.09.2016
— : Jürgen Kreick

EOF