ioperm — set port input/output permissions
#include <unistd.h> /* for libc5 */ #include <sys/io.h> /* for glibc */
int
ioperm( |
unsigned long | from, |
| unsigned long | num, | |
| int | turn_on); |
ioperm() sets the port
access permission bits for the calling process for num bytes starting from port
address from to the
value turn_on. If
turn_on is nonzero,
the calling process must be privileged (CAP_SYS_RAWIO).
Only the first 0x3ff I/O ports can be specified in this manner. For more ports, the iopl(2) system call must be used.
Permissions are not inherited by the child created by fork(2). Permissions are preserved across execve(2); this is useful for giving port access permissions to non-privileged programs.
This call is mostly for the i386 architecture. On many other architectures it does not exist or will always return an error.
On success, zero is returned. On error, −1 is
returned, and errno is set
appropriately.
Invalid values for from or num.
(on PowerPC) This call is not supported.
Out of memory.
The calling process has insufficient privilege.
ioperm() is Linux-specific
and should not be used in programs intended to be
portable.
Libc5 treats it as a system call and has a prototype in
<unistd.h>
Glibc1 does not have a prototype. Glibc2 has a prototype both
in <sys/io.h>
and in <sys/perm.h>
Avoid the latter, it is available on i386 only.
This page is part of release 2.79 of the Linux man-pages project. A
description of the project, and information about reporting
bugs, can be found at
http://www.kernel.org/doc/man-pages/.
|
Copyright (c) 1993 Michael Haardt (michaelmoria.de) Fri Apr 2 11:32:09 MET DST 1993 This is free documentation; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU General Public License's references to "object code" and "executables" are to be interpreted as the output of any document formatting or typesetting system, including intermediate and printed output. This manual is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this manual; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. Modified Sat Jul 24 15:12:05 1993 by Rik Faith <faithcs.unc.edu> Modified Tue Aug 1 16:27 1995 by Jochen Karrer <cip307cip.physik.uni-wuerzburg.de> Modified Tue Oct 22 08:11:14 EDT 1996 by Eric S. Raymond <esrthyrsus.com> Modified Mon Feb 15 17:28:41 CET 1999 by Andries E. Brouwer <aebcwi.nl> Modified, 27 May 2004, Michael Kerrisk <mtk.manpagesgmail.com> Added notes on capability requirements |