xref: /freebsd/contrib/elftoolchain/libelf/gelf_getrel.3 (revision bc3f5ec90bde2f3a5e4021d133c89793d68b8c73)
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24.\" $Id: gelf_getrel.3 189 2008-07-20 10:38:08Z jkoshy $
25.\"
26.Dd August 29, 2006
27.Os
28.Dt GELF_GETREL 3
29.Sh NAME
30.Nm gelf_getrel ,
31.Nm gelf_update_rel
32.Nd read and update ELF relocation entries
33.Sh LIBRARY
34.Lb libelf
35.Sh SYNOPSIS
36.In gelf.h
37.Ft "GElf_Rel *"
38.Fn gelf_getrel "Elf_Data *data" "int ndx" "GElf_Rel *rel"
39.Ft int
40.Fn gelf_update_rel "Elf_Data *data" "int ndx" "GElf_Rel *rel"
41.Sh DESCRIPTION
42These convenience functions are used to retrieve and update class-dependent
43.Vt Elf32_Rel
44or
45.Vt Elf64_Rel
46structures in an ELF object.
47.Pp
48Argument
49.Ar data
50is an
51.Vt Elf_Data
52descriptor associated with a section of type
53.Dv SHT_REL .
54Argument
55.Ar ndx
56is the index of the entry being retrieved or updated.
57The class-independent
58.Vt GElf_Rel
59structure is described in
60.Xr gelf 3 .
61.Pp
62Function
63.Fn gelf_getrel
64retrieves the class-dependent entry at index
65.Ar ndx
66in data buffer
67.Ar data
68and copies it to the destination pointed to by argument
69.Ar rel
70after translation to class-independent form.
71.Pp
72Function
73.Fn gelf_update_rel
74converts the class-independent entry pointed to
75by argument
76.Ar rel
77to class-dependent form, and writes it to the entry at index
78.Ar ndx
79in the data buffer described by argument
80.Ar data .
81Function
82.Fn gelf_update_rel
83signals an error if any of the values in the class-independent
84representation exceeds the representable limits of the target
85type.
86.Sh RETURN VALUES
87Function
88.Fn gelf_getrel
89returns the value of argument
90.Ar rel
91if successful, or NULL in case of an error.
92Function
93.Fn gelf_update_rel
94returns a non-zero value if successful, or zero in case of an error.
95.Sh ERRORS
96These functions may fail with the following errors:
97.Bl -tag -width "[ELF_E_RESOURCE]"
98.It Bq Er ELF_E_ARGUMENT
99Arguments
100.Ar data
101or
102.Ar rel
103were NULL.
104.It Bq Er ELF_E_ARGUMENT
105Argument
106.Ar ndx
107was less than zero or larger than the number of entries in the data
108descriptor.
109.It Bq Er ELF_E_ARGUMENT
110Data descriptor
111.Ar data
112was not associated with a section of type
113.Dv SHT_REL .
114.It Bq Er ELF_E_RANGE
115A value was not representable in the target type.
116.El
117.Sh SEE ALSO
118.Xr elf 3 ,
119.Xr elf_getdata 3 ,
120.Xr elf_getscn 3 ,
121.Xr gelf 3
122