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Diffstat (limited to 'lib/libelf/gelf_newehdr.3')
-rw-r--r-- | lib/libelf/gelf_newehdr.3 | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/lib/libelf/gelf_newehdr.3 b/lib/libelf/gelf_newehdr.3 new file mode 100644 index 0000000..6a2edf8 --- /dev/null +++ b/lib/libelf/gelf_newehdr.3 @@ -0,0 +1,185 @@ +.\" Copyright (c) 2006,2007 Joseph Koshy. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" This software is provided by Joseph Koshy ``as is'' and +.\" any express or implied warranties, including, but not limited to, the +.\" implied warranties of merchantability and fitness for a particular purpose +.\" are disclaimed. in no event shall Joseph Koshy be liable +.\" for any direct, indirect, incidental, special, exemplary, or consequential +.\" damages (including, but not limited to, procurement of substitute goods +.\" or services; loss of use, data, or profits; or business interruption) +.\" however caused and on any theory of liability, whether in contract, strict +.\" liability, or tort (including negligence or otherwise) arising in any way +.\" out of the use of this software, even if advised of the possibility of +.\" such damage. +.\" +.\" $FreeBSD$ +.\" +.Dd October 22, 2007 +.Dt GELF_NEWEHDR 3 +.Os +.Sh NAME +.Nm elf32_newehdr , +.Nm elf64_newehdr , +.Nm gelf_newehdr +.Nd retrieve or allocate the object file header +.Sh LIBRARY +.Lb libelf +.Sh SYNOPSIS +.In libelf.h +.Ft "Elf32_Ehdr *" +.Fn elf32_newehdr "Elf *elf" +.Ft "Elf64_Ehdr *" +.Fn elf64_newehdr "Elf *elf" +.In gelf.h +.Ft "void *" +.Fn gelf_newehdr "Elf *elf" "int elfclass" +.Sh DESCRIPTION +These functions retrieve the ELF header from the ELF descriptor +.Ar elf , +allocating a new header if needed. +File data structures are translated to their in-memory representations +as described in +.Xr elf 3 . +.Pp +Function +.Fn elf32_newehdr +returns a pointer to a 32 bit +.Vt Elf32_Ehdr +structure. +Function +.Fn elf64_newehdr +returns a pointer to a 64 bit +.Vt Elf64_Ehdr structure. +.Pp +When argument +.Ar elfclass +has value +.Dv ELFCLASS32 , +function +.Fn gelf_newehdr +returns the value returned by +.Fn elf32_newehdr "elf" . +When argument +.Ar elfclass +has value +.Dv ELFCLASS64 +it returns the value returned by +.Fn elf64_newehdr "elf" . +.Pp +If a fresh header structure is allocated, the members of the +structure are initialized as follows: +.Bl -tag -width indent +.It Va "e_ident[EI_MAG0..EI_MAG3]" +Identification bytes at offsets +.Dv EI_MAG0 , +.Dv EI_MAG1 , +.Dv EI_MAG2 +and +.Dv EI_MAG3 +are set to the ELF signature. +.It Va "e_ident[EI_CLASS]" +The identification byte at offset +.Dv EI_CLASS +is set to the ELF class associated with the function being called +or to argument +.Ar elfclass +for function +.Fn gelf_newehdr . +.It Va "e_ident[EI_DATA]" +The identification byte at offset +.Dv EI_DATA +is set to +.Dv ELFDATANONE . +.It Va "e_ident[EI_VERSION]" +The identification byte at offset +.Dv EI_VERSION +is set to the ELF library's operating version set by a prior call to +.Xr elf_version 3 . +.It Va e_machine +is set to +.Dv EM_NONE . +.It Va e_type +is set to +.Dv ELF_K_NONE . +.It Va e_version +is set to the ELF library's operating version set by a prior call to +.Xr elf_version 3 . +.El +.Pp +Other members of the header are set to zero. +The application is responsible for changing these values +as needed before calling +.Fn elf_update . +.Pp +If successful, these three functions set the +.Dv ELF_F_DIRTY +flag on ELF descriptor +.Ar elf . +.Sh RETURN VALUES +These functions return a pointer to a translated header descriptor +if successful, or NULL on failure. +.Sh ERRORS +These functions can fail with the following errors: +.Bl -tag -width "[ELF_E_RESOURCE]" +.It Bq Er ELF_E_ARGUMENT +The argument +.Ar elf +was null. +.It Bq Er ELF_E_ARGUMENT +Argument +.Ar elf +was not a descriptor for an ELF object. +.It Bq Er ELF_E_ARGUMENT +Argument +.Ar elfclass +had an unsupported value. +.It Bq Er ELF_E_ARGUMENT +The class of the ELF descriptor +.Ar elf +did not match that of the requested operation. +.It Bq Er ELF_E_ARGUMENT +For function +.Fn gelf_newehdr , +the class of argument +.Ar elf +was not +.Dv ELFCLASSNONE +and did not match the argument +.Ar elfclass . +.It Bq Er ELF_E_CLASS +The ELF class of descriptor +.Ar elf +did not match that of the API function being called. +.It Bq Er ELF_E_HEADER +A malformed ELF header was detected. +.It Bq Er ELF_E_RESOURCE +An out of memory condition was detected during execution. +.It Bq Er ELF_E_SECTION +The ELF descriptor in argument +.Ar elf +did not adhere to the conventions used for extended numbering. +.It Bq Er ELF_E_VERSION +The ELF descriptor +.Ar elf +had an unsupported ELF version number. +.El +.Sh SEE ALSO +.Xr elf 3 , +.Xr elf32_getehdr 3 , +.Xr elf64_getehdr 3 , +.Xr elf_flagdata 3 , +.Xr elf_getident 3 , +.Xr elf_update 3 , +.Xr elf_version 3 , +.Xr gelf 3 , +.Xr gelf_getehdr 3 , +.Xr elf 5 |