+++ /dev/null
-.\" Copyright (c) 2013 by Michael Kerrisk <mtk.manpages@gmail.com>
-.\"
-.\" %%%LICENSE_START(VERBATIM)
-.\" Permission is granted to make and distribute verbatim copies of this
-.\" manual provided the copyright notice and this permission notice are
-.\" preserved on all copies.
-.\"
-.\" Permission is granted to copy and distribute modified versions of this
-.\" manual under the conditions for verbatim copying, provided that the
-.\" entire resulting derived work is distributed under the terms of a
-.\" permission notice identical to this one.
-.\"
-.\" Since the Linux kernel and libraries are constantly changing, this
-.\" manual page may be incorrect or out-of-date. The author(s) assume no
-.\" responsibility for errors or omissions, or for damages resulting from
-.\" the use of the information contained herein. The author(s) may not
-.\" have taken the same level of care in the production of this manual,
-.\" which is licensed free of charge, as they might when working
-.\" professionally.
-.\"
-.\" Formatted or processed versions of this manual, if unaccompanied by
-.\" the source, must acknowledge the copyright and authors of this work.
-.\" %%%LICENSE_END
-.\"
-.\" http://thread.gmane.org/gmane.linux.kernel/76552/focus=76803
-.\" From: Linus Torvalds <torvalds <at> transmeta.com>
-.\" Subject: Re: [PATCH] compatibility syscall layer (lets try again)
-.\" Newsgroups: gmane.linux.kernel
-.\" Date: 2002-12-05 02:51:12 GMT
-.\"
-.\" See also Section 11.3.3 of Understanding the Linux Kernel, 3rd edition
-.\"
-.TH RESTART_SYSCALL 2 2014-12-31 "Linux" "Linux Programmer's Manual"
-.SH NAME
-restart_syscall \- restart a system call after interruption by a stop signal
-.SH SYNOPSIS
-.B int restart_syscall(void);
-
-.IR Note :
-There is no glibc wrapper for this system call; see NOTES.
-.SH DESCRIPTION
-The
-.BR restart_syscall ()
-system call is used to restart certain system calls
-after a process that was stopped by a signal (e.g.,
-.BR SIGSTOP
-or
-.BR SIGTSTP )
-is later resumed after receiving a
-.BR SIGCONT
-signal.
-This system call is designed only for internal use by the kernel.
-
-.BR restart_syscall ()
-is used for restarting only those system calls that,
-when restarted, should adjust their time-related parameters\(emnamely
-.BR poll (2)
-(since Linux 2.6.24),
-.BR nanosleep (2)
-(since Linux 2.6),
-.BR clock_nanosleep (2)
-(since Linux 2.6),
-and
-.BR futex (2),
-when employed with the
-.BR FUTEX_WAIT
-(since Linux 2.6.22)
-and
-.BR FUTEX_WAIT_BITSET
-(since Linux 2.6.31)
-operations.
-.\" These system calls correspond to the special internal errno value
-.\" ERESTART_RESTARTBLOCK. Each of the system calls has a "restart"
-.\" helper function that is invoked by restart_syscall().
-.\" Notable (as at Linux 3.17) is that poll() has such a "restart"
-.\" function, but ppoll(), select(), and pselect() do not.
-.\" This means that the latter system calls do not take account of the
-.\" time spent in the stopped state when restarting.
-.BR restart_syscall ()
-restarts the interrupted system call with a
-time argument that is suitably adjusted to account for the
-time that has already elapsed (including the time where the process
-was stopped by a signal).
-Without the
-.BR restart_syscall ()
-mechanism, restarting these system calls would not correctly deduct the
-already elapsed time when the process continued execution.
-.SH RETURN VALUE
-The return value of
-.BR restart_syscall ()
-is the return value of whatever system call is being restarted.
-.SH ERRORS
-.I errno
-is set as per the errors for whatever system call is being restarted by
-.BR restart_syscall ().
-.SH VERSIONS
-The
-.BR restart_syscall ()
-system call is present since Linux 2.6.
-.SH CONFORMING TO
-This system call is Linux-specific.
-.SH NOTES
-There is no glibc wrapper for this system call,
-because it is intended for use only by the kernel and
-should never be called by applications.
-
-The kernel uses
-.BR restart_syscall ()
-to ensure that when a system call is restarted
-after a process has been stopped by a signal and then resumed by
-.BR SIGCONT ,
-then the time that the process spent in the stopped state is counted
-against the timeout interval specified in the original system call.
-In the case of system calls that take a timeout argument and
-automatically restart after a stop signal plus
-.BR SIGCONT ,
-but which do not have the
-.BR restart_syscall (2)
-mechanism built in, then, after the process resumes execution,
-the time that the process spent in the stop state is
-.I not
-counted against the timeout value.
-Notable examples of system calls that suffer this problem are
-.BR ppoll (2),
-.BR select (2),
-and
-.BR pselect (2).
-
-From user space, the operation of
-.BR restart_syscall (2)
-is largely invisible:
-to the process that made the system call that is restarted,
-it appears as though that system call executed and
-returned in the usual fashion.
-.SH SEE ALSO
-.BR sigaction (2),
-.BR sigreturn (2),
-.BR signal (7)
-.\" FIXME . ppoll(2), select(2), and pselect(2)
-.\" should probably get the restart_syscall() treatment:
-.\" If a select() call is suspended by stop-sig+SIGCONT, the time
-.\" spent suspended is *not* deducted when the select() is restarted.
-.\" FIXME . check whether recvmmsg() handles stop-sig+SIGCONT properly.
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
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