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.Dd October 5, 2023 .Dt ELFCTL 1 .Os .Sh NAME .Nm elfctl .Nd change an ELF binary's feature control note .Sh SYNOPSIS .Nm .Op Fl h | Fl -help .Op Fl i .Op Fl l .Op Fl e Ar featurelist .Ar .Sh DESCRIPTION The .Nm utility modifies feature flags in the feature control note in an ELF binary.
p The options are as follows: l -tag -width indent t Fl h | Fl -help Print a usage message and exit. t Fl i Ignore unknown feature flags in .Ar featurelist . t Fl l List known ELF feature flags. t Fl e Ar featurelist Edit features from the given comma separated list .Ar featurelist . .Ar featurelist starts with one of the three operations: .Dq Li + to turn on the features, .Dq Li - to turn off the features, .Dq Li = to only turn on the given features. A comma separated list of feature names or numeric values follows the operation. .El
p If .Fl e is not specified .Nm displays the status of each feature in the ELF note in each .Ar . .Sh EXIT STATUS Exit status is 0 on success, and 1 if the command fails if a file does not exist, is too short, or fails to find or edit features note. .Sh EXAMPLES The following is an example of a typical usage of the .Nm command: d -literal -offset indent elfctl file elfctl -e +noaslr file .Ed
p Features may be specified as numerical values: d -literal -offset -indent elfctl -e =0x0001,0x0004 file .Ed
p Features may also be specified as a single combined value: d -literal -offset -indent elfctl -e =0x5 file .Ed .Sh SEE ALSO .Xr mitigations 7 .Sh HISTORY .Nm first appeared in .Fx 12.2 . .Sh AUTHORS .Nm was written by .An Bora Ozarslan Mt borako.ozarslan@gmail.com under sponsorship from the .Fx Foundation.