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GELF_NEWEHDR(3)            Library Functions Manual            GELF_NEWEHDR(3)

NAME
     elf32_newehdr, elf64_newehdr, gelf_newehdr - retrieve or allocate the
     object file header

LIBRARY
     ELF Access Library (libelf, -lelf)

SYNOPSIS
     #include <libelf.h>

     Elf32_Ehdr *
     elf32_newehdr(Elf *elf);

     Elf64_Ehdr *
     elf64_newehdr(Elf *elf);

     #include <gelf.h>

     void *
     gelf_newehdr(Elf *elf, int elfclass);

DESCRIPTION
     These functions retrieve the ELF header from the ELF descriptor elf,
     allocating a new header if needed.  File data structures are translated
     to their in-memory representations as described in elf(3).

     Function elf32_newehdr() returns a pointer to a 32 bit Elf32_Ehdr
     structure.  Function elf64_newehdr() returns a pointer to a 64 bit
     Elf64_Ehdr structure.

     When argument elfclass has value ELFCLASS32, function gelf_newehdr()
     returns the value returned by elf32_newehdr(elf).  When argument elfclass
     has value ELFCLASS64 it returns the value returned by elf64_newehdr(elf).

     If a fresh header structure is allocated, the members of the structure
     are initialized as follows:

     e_ident[EI_MAG0..EI_MAG3]
             Identification bytes at offsets EI_MAG0, EI_MAG1, EI_MAG2 and
             EI_MAG3 are set to the ELF signature.

     e_ident[EI_CLASS]
             The identification byte at offset EI_CLASS is set to the ELF
             class associated with the function being called or to argument
             elfclass for function gelf_newehdr().

     e_ident[EI_DATA]
             The identification byte at offset EI_DATA is set to ELFDATANONE.

     e_ident[EI_VERSION]
             The identification byte at offset EI_VERSION is set to the ELF
             library's operating version set by a prior call to
             elf_version(3).

     e_machine
             is set to EM_NONE.

     e_type  is set to ELF_K_NONE.

     e_version
             is set to the ELF library's operating version set by a prior call
             to elf_version(3).

     Other members of the header are set to zero.  The application is
     responsible for changing these values as needed before calling
     elf_update().

     If successful, these three functions set the ELF_F_DIRTY flag on ELF
     descriptor elf.

RETURN VALUES
     These functions return a pointer to a translated header descriptor if
     successful, or NULL on failure.

COMPATIBILITY
     The gelf_newehdr() function uses a type of void * for its returned value.
     This differs from some other implementations of the elf(3) API, which use
     an unsigned long return type.

ERRORS
     These functions can fail with the following errors:

     [ELF_E_ARGUMENT]  The argument elf was null.

     [ELF_E_ARGUMENT]  Argument elf was not a descriptor for an ELF object.

     [ELF_E_ARGUMENT]  Argument elfclass had an unsupported value.

     [ELF_E_ARGUMENT]  The class of the ELF descriptor elf did not match that
                       of the requested operation.

     [ELF_E_ARGUMENT]  For function gelf_newehdr(), the class of argument elf
                       was not ELFCLASSNONE and did not match the argument
                       elfclass.

     [ELF_E_CLASS]     The ELF class of descriptor elf did not match that of
                       the API function being called.

     [ELF_E_HEADER]    A malformed ELF header was detected.

     [ELF_E_RESOURCE]  An out of memory condition was detected during
                       execution.

     [ELF_E_SECTION]   The ELF descriptor in argument elf did not adhere to
                       the conventions used for extended numbering.

     [ELF_E_VERSION]   The ELF descriptor elf had an unsupported ELF version
                       number.

SEE ALSO
     elf(3), elf32_getehdr(3), elf64_getehdr(3), elf_flagdata(3),
     elf_getident(3), elf_update(3), elf_version(3), gelf(3), gelf_getehdr(3),
     elf(5)

NetBSD 10.99                     June 12, 2019                    NetBSD 10.99