afs_syscall, break, fattach, fdetach, ftime, getmsg, getpmsg, gtty, isastream, lock, madvise1, mpx, prof, profil, putmsg, putpmsg, security, stty, tuxcall, ulimit, vserver — unimplemented system calls


Unimplemented system calls.


These system calls are not implemented in the Linux kernel.

Return Value

These system calls always return -1 and set errno to ENOSYS.


Note that ftime(3), profil(3), and ulimit(3) are implemented as library functions.

Some system calls, like alloc_hugepages(2), free_hugepages(2), ioperm(2), iopl(2), and vm86(2) exist only on certain architectures.

Some system calls, like ipc(2), create_module(2), init_module(2), and delete_module(2) exist only when the Linux kernel was built with support for them.

See Also



This page is part of release 5.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at

Referenced By

syscalls(2), systemd.exec(5).

The man pages afs_syscall(2), break(2), fattach(2), fdetach(2), getmsg(2), getpmsg(2), gtty(2), isastream(2), lock(2), madvise1(2), mpx(2), phys(2), prof(2), putmsg(2), putpmsg(2), security(2), stty(2), tuxcall(2) and vserver(2) are aliases of unimplemented(2).

2017-09-15 Linux Programmer's Manual