Manpage of IOPERM
IOPERMSection: Linux Programmer's Manual (2)
NAMEioperm - set port input/output permissions
SYNOPSIS#include <sys/io.h>/* for glibc */
DESCRIPTIONioperm() sets the port access permission bits for the calling thread for numbits starting from port address from. If turn_onis nonzero, then permission for the specified bits is enabled; otherwise it is disabled. If turn_onis nonzero, the calling thread must be privileged (CAP_SYS_RAWIO).
Before Linux 2.6.8, only the first 0x3ff I/O ports could be specified in this manner. For more ports, the iopl(2) system call had to be used (with a levelargument of 3). Since Linux 2.6.8, 65,536 I/O ports can be specified.
RETURN VALUEOn success, zero is returned. On error, -1 is returned, and errnois set appropriately.
- Invalid values for fromor num.
- (on PowerPC) This call is not supported.
- Out of memory.
- The calling thread has insufficient privilege.
CONFORMING TOioperm() is Linux-specific and should not be used in programs intended to be portable.
NOTESThe /proc/ioportsfile shows the I/O ports that are currently allocated on the system.
Before Linux 2.4, permissions were not inherited by a child created by fork(2).
SEE ALSOiopl(2), outb(2), capabilities(7)
This document was created by man2html, using the manual pages.
Time: 16:30:08 GMT, March 14, 2017 Click Here!