iopl(2) — Справочная страница Linux

iopl(2)                    System Calls Manual                   iopl(2)

ИМЯ

       iopl - change I/O privilege level

БИБЛИОТЕКА

       Standard C library (libc, -lc)

СИНТАКСИС

       #include <sys/io.h>

       [[deprecated]] int iopl(int level);

ОПИСАНИЕ

       iopl() changes the I/O privilege level of the calling thread, as
       specified by the two least significant bits in level.

       The I/O privilege level for a normal thread is 0.  Permissions
       are inherited from parents to children.

       This call is deprecated, is significantly slower than ioperm(2),
       and is only provided for older X servers which require access to
       all 65536 I/O ports.  It is mostly for the i386 architecture.  On
       many other architectures it does not exist or will always return
       an error.

ЗНАЧЕНИЕ, ВОЗВРАЩАЕМОЕ ФУНКЦИЕЙ

       On success, zero is returned.  On error, -1 is returned, and
       errno is set to indicate the error.

ОШИБКИ

       EINVAL level is greater than 3.

       ENOSYS This call is unimplemented.

       EPERM  The calling thread has insufficient privilege to call
              iopl(); the CAP_SYS_RAWIO capability is required to raise
              the I/O privilege level above its current value.

ВЕРСИИ

       glibc2 has a prototype both in <sys/io.h> and in <sys/perm.h>.
       Avoid the latter, it is available on i386 only.

СТАНДАРТЫ

       Linux.

ИСТОРИЯ

       Prior to Linux 5.5 iopl() allowed the thread to disable
       interrupts while running at a higher I/O privilege level.  This
       will probably crash the system, and is not recommended.

       Prior to Linux 3.7, on some architectures (such as i386),
       permissions were inherited by the child produced by fork(2) and
       were preserved across execve(2).  This behavior was inadvertently
       changed in Linux 3.7, and won't be reinstated.

СМОТРИТЕ ТАКЖЕ

       ioperm(2), outb(2), capabilities(7)

КОЛОФОН

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report
       for this manual page, see
       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
       This page was obtained from the tarball man-pages-6.9.1.tar.gz
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       2024-06-26.  If you discover any rendering problems in this HTML
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       man-pages@man7.org

Linux man-pages 6.9.1          2024-05-02                        iopl(2)

Страницы, которые ссылаются на эту страницу: ioperm(2), outb(2), syscalls(2), unimplemented(2), systemd.exec(5), capabilities(7)