1 .\" Copyright (c) 1993 Michael Haardt
3 .\" Fri Apr 2 11:32:09 MET DST 1993
5 .\" %%%LICENSE_START(GPLv2+_DOC_FULL)
6 .\" This is free documentation; you can redistribute it and/or
7 .\" modify it under the terms of the GNU General Public License as
8 .\" published by the Free Software Foundation; either version 2 of
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11 .\" The GNU General Public License's references to "object code"
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19 .\" GNU General Public License for more details.
21 .\" You should have received a copy of the GNU General Public
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26 .\" Modified Sat Jul 24 15:12:05 1993 by Rik Faith <faith@cs.unc.edu>
27 .\" Modified Tue Aug 1 16:27 1995 by Jochen Karrer
28 .\" <cip307@cip.physik.uni-wuerzburg.de>
29 .\" Modified Tue Oct 22 08:11:14 EDT 1996 by Eric S. Raymond <esr@thyrsus.com>
30 .\" Modified Mon Feb 15 17:28:41 CET 1999 by Andries E. Brouwer <aeb@cwi.nl>
31 .\" Modified, 27 May 2004, Michael Kerrisk <mtk.manpages@gmail.com>
32 .\" Added notes on capability requirements
34 .TH IOPERM 2 2013-03-12 "Linux" "Linux Programmer's Manual"
36 ioperm \- set port input/output permissions
38 .B #include <unistd.h>
41 .B #include <sys/io.h>
44 .BI "int ioperm(unsigned long " from ", unsigned long " num ", int " turn_on );
47 sets the port access permission bits for the calling thread for
49 bits starting from port address
53 is nonzero, then permission for the specified bits is enabled;
54 otherwise it is disabled.
57 is nonzero, the calling thread must be privileged
58 .RB ( CAP_SYS_RAWIO ).
61 only the first 0x3ff I/O ports could be specified in this manner.
64 system call had to be used (with a
67 Since Linux 2.6.8, 65,536 I/O ports can be specified.
69 Permissions are not inherited by the child created by
73 the child must turn on those permissions that it needs.
74 Permissions are preserved across
76 this is useful for giving port access permissions to unprivileged
79 This call is mostly for the i386 architecture.
80 On many other architectures it does not exist or will always
83 On success, zero is returned.
84 On error, \-1 is returned, and
96 (on PowerPC) This call is not supported.
99 .\" Could not allocate I/O bitmap.
103 The calling thread has insufficient privilege.
106 is Linux-specific and should not be used in programs
107 intended to be portable.
111 file shows the I/O ports that are currently allocated on the system.
113 Libc5 treats it as a system call and has a prototype in
115 Glibc1 does not have a prototype.
116 Glibc2 has a prototype both in
120 Avoid the latter, it is available on i386 only.
126 This page is part of release 3.68 of the Linux
129 A description of the project,
130 information about reporting bugs,
131 and the latest version of this page,
133 \%http://www.kernel.org/doc/man\-pages/.