xref: /freebsd/usr.bin/elfctl/elfctl.1 (revision edf7c8ddcecae93ced005144b6eeac14e08ade8e)
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3.\" This software was developed by Bora Ozarslan under sponsorship from
4.\" the FreeBSD Foundation.
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27.\" $FreeBSD$
28.\"
29.Dd January 12, 2021
30.Dt ELFCTL 1
31.Os
32.Sh NAME
33.Nm elfctl
34.Nd change an ELF binary's feature control note
35.Sh SYNOPSIS
36.Nm
37.Op Fl h | Fl -help
38.Op Fl i
39.Op Fl l
40.Op Fl e Ar featurelist
41.Ar
42.Sh DESCRIPTION
43The
44.Nm
45utility modifies feature flags in the feature control note in an ELF binary.
46.Pp
47The options are as follows:
48.Bl -tag -width indent
49.It Fl h | Fl -help
50Print a usage message and exit.
51.It Fl i
52Ignore unknown feature flags in
53.Ar featurelist .
54.It Fl l
55List known ELF feature flags.
56.It Fl e Ar featurelist
57Edit features from the given comma separated list
58.Ar featurelist .
59.Ar featurelist
60starts with one of the three operations:
61.Dq Li +
62to turn on the features,
63.Dq Li -
64to turn off the features,
65.Dq Li =
66to only turn on the given features.
67A comma separated list of feature names follows the operation.
68.El
69.Pp
70If
71.Fl e
72is not specified
73.Nm
74displays the status of each feature in the ELF note in each
75.Ar .
76.Sh EXIT STATUS
77Exit status is 0 on success, and 1 if the command
78fails if a file does not exist, is too short,
79or fails to find or edit features note.
80.Sh EXAMPLES
81The following is an example of a typical usage
82of the
83.Nm
84command:
85.Bd -literal -offset indent
86elfctl file
87elfctl -e +aslr file
88.Ed
89.Sh HISTORY
90.Nm
91first appeared in
92.Fx 12.2 .
93.Sh AUTHORS
94.Nm
95was written by
96.An Bora Ozarslan Mt borako.ozarslan@gmail.com
97under sponsorship from the
98.Fx Foundation.
99