1.\" $NetBSD: gelf_getrel.3,v 1.6 2024/03/03 17:37:34 christos Exp $ 2.\" 3.\" Copyright (c) 2006,2008 Joseph Koshy. All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" This software is provided by Joseph Koshy ``as is'' and 15.\" any express or implied warranties, including, but not limited to, the 16.\" implied warranties of merchantability and fitness for a particular purpose 17.\" are disclaimed. in no event shall Joseph Koshy be liable 18.\" for any direct, indirect, incidental, special, exemplary, or consequential 19.\" damages (including, but not limited to, procurement of substitute goods 20.\" or services; loss of use, data, or profits; or business interruption) 21.\" however caused and on any theory of liability, whether in contract, strict 22.\" liability, or tort (including negligence or otherwise) arising in any way 23.\" out of the use of this software, even if advised of the possibility of 24.\" such damage. 25.\" 26.\" Id: gelf_getrel.3 3958 2022-03-12 14:31:32Z jkoshy 27.\" 28.Dd April 22, 2019 29.Dt GELF_GETREL 3 30.Os 31.Sh NAME 32.Nm gelf_getrel , 33.Nm gelf_update_rel 34.Nd read and update ELF relocation entries 35.Sh LIBRARY 36.Lb libelf 37.Sh SYNOPSIS 38.In gelf.h 39.Ft "GElf_Rel *" 40.Fn gelf_getrel "Elf_Data *data" "int ndx" "GElf_Rel *rel" 41.Ft int 42.Fn gelf_update_rel "Elf_Data *data" "int ndx" "GElf_Rel *rel" 43.Sh DESCRIPTION 44These convenience functions are used to retrieve and update class-dependent 45.Vt Elf32_Rel 46or 47.Vt Elf64_Rel 48structures in an ELF object. 49.Pp 50Argument 51.Fa data 52is an 53.Vt Elf_Data 54descriptor associated with a section of type 55.Dv SHT_REL . 56Argument 57.Fa ndx 58is the index of the entry being retrieved or updated. 59The class-independent 60.Vt GElf_Rel 61structure is described in 62.Xr gelf 3 . 63.Pp 64Function 65.Fn gelf_getrel 66retrieves the class-dependent entry at index 67.Fa ndx 68in data buffer 69.Fa data 70and copies it to the destination pointed to by argument 71.Fa rel 72after translation to class-independent form. 73.Pp 74Function 75.Fn gelf_update_rel 76converts the class-independent entry pointed to 77by argument 78.Fa rel 79to class-dependent form, and writes it to the entry at index 80.Fa ndx 81in the data buffer described by argument 82.Fa data . 83Function 84.Fn gelf_update_rel 85signals an error if any of the values in the class-independent 86representation exceeds the representable limits of the target 87type. 88.Sh RETURN VALUES 89Function 90.Fn gelf_getrel 91returns the value of argument 92.Fa rel 93if successful, or 94.Dv NULL 95in case of an error. 96Function 97.Fn gelf_update_rel 98returns a non-zero value if successful, or zero in case of an error. 99.Sh ERRORS 100These functions may fail with the following errors: 101.Bl -tag -width "[ELF_E_RESOURCE]" 102.It Bq Er ELF_E_ARGUMENT 103Arguments 104.Fa data 105or 106.Fa rel 107were 108.Dv NULL . 109.It Bq Er ELF_E_ARGUMENT 110Argument 111.Fa ndx 112was less than zero or larger than the number of entries in the data 113descriptor. 114.It Bq Er ELF_E_ARGUMENT 115Data descriptor 116.Fa data 117was not associated with a section of type 118.Dv SHT_REL . 119.It Bq Er ELF_E_RANGE 120A value was not representable in the target type. 121.It Bq Er ELF_E_VERSION 122The 123.Vt Elf_Data 124descriptor denoted by argument 125.Fa data 126is associated with an ELF object with an unsupported version. 127.El 128.Sh SEE ALSO 129.Xr elf 3 , 130.Xr elf_getdata 3 , 131.Xr elf_getscn 3 , 132.Xr gelf 3 133