xref: /freebsd/contrib/elftoolchain/libelf/gelf_checksum.3 (revision fed1ca4b719c56c930f2259d80663cd34be812bb)
1.\" Copyright (c) 2006,2008 Joseph Koshy.  All rights reserved.
2.\"
3.\" Redistribution and use in source and binary forms, with or without
4.\" modification, are permitted provided that the following conditions
5.\" are met:
6.\" 1. Redistributions of source code must retain the above copyright
7.\"    notice, this list of conditions and the following disclaimer.
8.\" 2. Redistributions in binary form must reproduce the above copyright
9.\"    notice, this list of conditions and the following disclaimer in the
10.\"    documentation and/or other materials provided with the distribution.
11.\"
12.\" This software is provided by Joseph Koshy ``as is'' and
13.\" any express or implied warranties, including, but not limited to, the
14.\" implied warranties of merchantability and fitness for a particular purpose
15.\" are disclaimed.  in no event shall Joseph Koshy be liable
16.\" for any direct, indirect, incidental, special, exemplary, or consequential
17.\" damages (including, but not limited to, procurement of substitute goods
18.\" or services; loss of use, data, or profits; or business interruption)
19.\" however caused and on any theory of liability, whether in contract, strict
20.\" liability, or tort (including negligence or otherwise) arising in any way
21.\" out of the use of this software, even if advised of the possibility of
22.\" such damage.
23.\"
24.\" $Id: gelf_checksum.3 189 2008-07-20 10:38:08Z jkoshy $
25.\"
26.Dd August 29, 2006
27.Os
28.Dt GELF_CHECKSUM 3
29.Sh NAME
30.Nm elf32_checksum ,
31.Nm elf64_checksum ,
32.Nm gelf_checksum
33.Nd return the checksum of an ELF object
34.Sh LIBRARY
35.Lb libelf
36.Sh SYNOPSIS
37.In libelf.h
38.Ft long
39.Fn elf32_checksum "Elf *elf"
40.Ft long
41.Fn elf64_checksum "Elf *elf"
42.In gelf.h
43.Ft long
44.Fn gelf_checksum "Elf *elf"
45.Sh DESCRIPTION
46These functions return a simple checksum of the ELF object described
47by their argument
48.Ar elf .
49The checksum is computed in way that allows its value to remain
50unchanged in presence of modifications to the ELF object by utilities
51like
52.Xr strip 1 .
53.Pp
54Function
55.Fn elf32_checksum
56returns a checksum for an ELF descriptor
57.Ar elf
58of class
59.Dv ELFCLASS32 .
60.Pp
61Function
62.Fn elf64_checksum
63returns a checksum for an ELF descriptor
64.Ar elf
65of class
66.Dv ELFCLASS64 .
67.Pp
68Function
69.Fn gelf_checksum
70provides a class-independent way retrieving the checksum
71for ELF object
72.Ar elf .
73.Sh RETURN VALUES
74These functions return the checksum of the ELF object, or zero in case
75an error was encountered.
76.Sh ERRORS
77These functions may fail with the following errors:
78.Bl -tag -width "[ELF_E_RESOURCE]"
79.It Bq Er ELF_E_ARGUMENT
80Argument
81.Ar elf
82was NULL.
83.It Bq Er ELF_E_ARGUMENT
84Argument
85.Ar elf
86was not a descriptor for an ELF file.
87.It Bq Er ELF_E_ARGUMENT
88The ELF descriptor
89.Ar elf
90was not opened for reading or updating.
91.It Bq Er ELF_E_CLASS
92For functions
93.Fn elf32_checksum
94and
95.Fn elf64_checksum ,
96ELF descriptor
97.Ar elf
98did not match the class of the called function.
99.It Bq Er ELF_E_HEADER
100The ELF object specified by argument
101.Ar elf
102had a malformed executable header.
103.It Bq Er ELF_E_RESOURCE
104An out of memory condition was detected during processing.
105.It Bq Er ELF_E_SECTION
106The ELF object specified by argument
107.Ar elf
108contained a section with a malformed section header.
109.It Bq Er ELF_E_VERSION
110The ELF object was of an unsupported version.
111.El
112.Sh SEE ALSO
113.Xr strip 1 ,
114.Xr elf 3 ,
115.Xr gelf 3
116