.\"	$NetBSD: paxctl.8,v 1.16.24.1 2023/06/27 18:20:18 martin Exp $
.\"
.\" Copyright 2006 Elad Efrat <elad@NetBSD.org>
.\" Copyright 2008 Christos Zoulas <christos@NetBSD.org>
.\" All rights reserved.
.\"
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.Dd June 23, 2023
.Dt PAXCTL 8
.Os
.Sh NAME
.Nm paxctl
.Nd list and modify PaX flags associated with an ELF program
.Sh SYNOPSIS
.Nm
.Op Fl 0 | Cm flags
.Ar program ...
.Sh DESCRIPTION
The
.Nm
utility is used to list and manipulate PaX flags associated with an ELF
program.
The PaX flags signify to the loader the privilege protections to be applied
to mapped memory pages, and fuller explanations of the specific protections
can be found in the
.Xr security 7
manpage.
.Pp
If
.Fl 0
option is specified, all PaX flags (including reserved bits) are cleared.
Otherwise, each flag can be prefixed either with a
.Dq +
or a
.Dq -
sign to add or remove the flag, respectively.
.Pp
The following flags are available:
.Bl -tag -width flag
.It a
Explicitly disable PaX ASLR (Address Space Layout Randomization) for
.Ar program .
.It A
Explicitly enable PaX ASLR for
.Ar program .
.It g
Explicitly disable PaX Segvguard for
.Ar program .
.It G
Explicitly enable PaX Segvguard for
.Ar program .
.It m
Explicitly disable PaX MPROTECT
.Po Xr mprotect 2
restrictions
.Pc
for
.Ar program .
.It M
Explicitly enable PaX MPROTECT
.Po Xr mprotect 2
restrictions
.Pc
for
.Ar program .
.El
.Pp
To view existing flags on a file, execute
.Nm
without any flags.
.Sh SEE ALSO
.Xr mprotect 2 ,
.Xr sysctl 3 ,
.Xr options 4 ,
.Xr elf 5 ,
.Xr security 7 ,
.Xr sysctl 8 ,
.Xr fileassoc 9
.Sh HISTORY
The
.Nm
utility first appeared in
.Nx 4.0 .
.Pp
The
.Nm
utility is modeled after a tool of the same name available for Linux from the
PaX project.
.Sh AUTHORS
.An Elad Efrat Aq Mt elad@NetBSD.org
.An Christos Zoulas Aq Mt christos@NetBSD.org
.Sh BUGS
The
.Nm
utility currently uses
.Xr elf 5
.Dq note
sections to mark executables as having PaX flags enabled.
This will be done using
.Xr fileassoc 9
in the future so that we can control who does the marking and
not altering the binary file signature.
(Note this also means that
at present any flags set do not survive binary file upgrades.)