new syscalls
This commit is contained in:
cgd
parent
081527a861
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fc7bd30680
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@ -0,0 +1,161 @@
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.\" Copyright (c) 1993
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.\" The Regents of the University of California. All rights reserved.
|
||||
.\"
|
||||
.\" Redistribution and use in source and binary forms, with or without
|
||||
.\" modification, are permitted provided that the following conditions
|
||||
.\" are met:
|
||||
.\" 1. Redistributions of source code must retain the above copyright
|
||||
.\" notice, this list of conditions and the following disclaimer.
|
||||
.\" 2. Redistributions in binary form must reproduce the above copyright
|
||||
.\" notice, this list of conditions and the following disclaimer in the
|
||||
.\" documentation and/or other materials provided with the distribution.
|
||||
.\" 3. All advertising materials mentioning features or use of this software
|
||||
.\" must display the following acknowledgement:
|
||||
.\" This product includes software developed by the University of
|
||||
.\" California, Berkeley and its contributors.
|
||||
.\" 4. Neither the name of the University nor the names of its contributors
|
||||
.\" may be used to endorse or promote products derived from this software
|
||||
.\" without specific prior written permission.
|
||||
.\"
|
||||
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
||||
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||||
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||||
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
||||
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||||
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||||
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||||
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||||
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)mlock.2 8.2 (Berkeley) 12/11/93
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.\"
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.Dd June 2, 1993
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.Dt MLOCK 2
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.Os
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.Sh NAME
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.Nm mlock ,
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.Nm munlock
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.Nd lock (unlock) physical pages in memory
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.Sh SYNOPSIS
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.Fd #include <sys/types.h>
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.Fd #include <sys/mman.h>
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.Ft int
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.Fn mlock "caddr_t addr" "size_t len"
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.Ft int
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.Fn munlock "caddr_t addr" "size_t len"
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.Sh DESCRIPTION
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The
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.Nm mlock
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system call
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locks into memory the physical pages associated with the virtual address
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range starting at
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.Fa addr
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for
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.Fa len
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bytes.
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The
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.Nm munlock
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call unlocks pages previously locked by one or more
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.Nm mlock
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calls.
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For both, the
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.Fa addr
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parameter should be aligned to a multiple of the page size.
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If the
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.Fa len
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parameter is not a multiple of the page size, it will be rounded up
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to be so.
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The entire range must be allocated.
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.Pp
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After an
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.Nm mlock
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call, the indicated pages will cause neither a non-resident page
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nor address-translation fault until they are unlocked.
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They may still cause protection-violation faults or TLB-miss faults on
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architectures with software-managed TLBs.
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The physical pages remain in memory until all locked mappings for the pages
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are removed.
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Multiple processes may have the same physical pages locked via their own
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virtual address mappings.
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A single process may likewise have pages multiply-locked via different virtual
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mappings of the same pages or via nested
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.Nm mlock
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calls on the same address range.
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Unlocking is performed explicitly by
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.Nm munlock
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or implicitly by a call to
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.Nm munmap
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which deallocates the unmapped address range.
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Locked mappings are not inherited by the child process after a
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.Xr fork 2 .
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.Pp
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Since physical memory is a potentially scarce resource, processes are
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limited in how much they can lock down.
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A single process can
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.Nm mlock
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the minimum of
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a system-wide ``wired pages'' limit and
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the per-process
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.Li RLIMIT_MEMLOCK
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resource limit.
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.Sh RETURN VALUES
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A return value of 0 indicates that the call
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succeeded and all pages in the range have either been locked or unlocked.
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A return value of -1 indicates an error occurred and the locked
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status of all pages in the range remains unchanged.
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In this case, the global location
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.Va errno
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is set to indicate the error.
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.Sh ERRORS
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.Fn Mlock
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will fail if:
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.Bl -tag -width Er
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.It Bq Er EINVAL
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The address given is not page aligned or the length is negative.
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.It Bq Er EAGAIN
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Locking the indicated range would exceed either the system or per-process
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limit for locked memory.
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.It Bq Er ENOMEM
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Some portion of the indicated address range is not allocated.
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There was an error faulting/mapping a page.
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.El
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.Fn Munlock
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will fail if:
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.Bl -tag -width Er
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.It Bq Er EINVAL
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The address given is not page aligned or the length is negative.
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.It Bq Er ENOMEM
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Some portion of the indicated address range is not allocated.
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Some portion of the indicated address range is not locked.
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.El
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.Sh "SEE ALSO"
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.Xr fork 2 ,
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.Xr mmap 2 ,
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.Xr munmap 2 ,
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.Xr setrlimit 2 ,
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.Xr getpagesize 3
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.Sh BUGS
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Unlike The Sun implementation, multiple
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.Nm mlock
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calls on the same address range require the corresponding number of
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.Nm munlock
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calls to actually unlock the pages, i.e.
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.Nm mlock
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nests.
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This should be considered a consequence of the implementation
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and not a feature.
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.Pp
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The per-process resource limit is a limit on the amount of virtual
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memory locked, while the system-wide limit is for the number of locked
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physical pages.
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Hence a process with two distinct locked mappings of the same physical page
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counts as 2 pages against the per-process limit and as only a single page
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in the system limit.
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.Sh HISTORY
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The
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.Fn mlock
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and
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.Fn munlock
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functions first appeared in 4.4BSD.
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@ -0,0 +1,163 @@
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.\" Copyright (c) 1993
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.\" The Regents of the University of California. All rights reserved.
|
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.\"
|
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.\" Redistribution and use in source and binary forms, with or without
|
||||
.\" modification, are permitted provided that the following conditions
|
||||
.\" are met:
|
||||
.\" 1. Redistributions of source code must retain the above copyright
|
||||
.\" notice, this list of conditions and the following disclaimer.
|
||||
.\" 2. Redistributions in binary form must reproduce the above copyright
|
||||
.\" notice, this list of conditions and the following disclaimer in the
|
||||
.\" documentation and/or other materials provided with the distribution.
|
||||
.\" 3. All advertising materials mentioning features or use of this software
|
||||
.\" must display the following acknowledgement:
|
||||
.\" This product includes software developed by the University of
|
||||
.\" California, Berkeley and its contributors.
|
||||
.\" 4. Neither the name of the University nor the names of its contributors
|
||||
.\" may be used to endorse or promote products derived from this software
|
||||
.\" without specific prior written permission.
|
||||
.\"
|
||||
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
||||
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||||
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||||
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
||||
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||||
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||||
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||||
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||||
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)pathconf.2 8.1 (Berkeley) 6/4/93
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.\"
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.Dd June 4, 1993
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.Dt PATHCONF 2
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.Os BSD 4
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.Sh NAME
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.Nm pathconf ,
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.Nm fpathconf
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.Nd get configurable pathname variables
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.Sh SYNOPSIS
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.Fd #include <unistd.h>
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.Ft long
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.Fn pathconf "const char *path" "int name"
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.Ft long
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.Fn fpathconf "int fd" "int name"
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.Sh DESCRIPTION
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.Pp
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The
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.Fn pathconf
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and
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.Fn fpathconf
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functions provides a method for applications to determine the current
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value of a configurable system limit or option variable associated
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with a pathname or file descriptor.
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.Pp
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For
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.Nm pathconf ,
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the
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.Fa path
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argument is the name of a file or directory.
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For
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.Nm fpathconf ,
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the
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.Fa fd
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argument is an open file descriptor.
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The
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.Fa name
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argument specifies the system variable to be queried.
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Symbolic constants for each name value are found in the include file
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.Li <unistd.h> .
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.Pp
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The available values are as follows:
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.Pp
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.Bl -tag -width "123456"
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.Pp
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.It Li _PC_LINK_MAX
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The maximum file link count.
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.It Li _PC_MAX_CANON
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The maximum number of bytes in terminal canonical input line.
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.It Li _PC_MAX_INPUT
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The minimum maximum number of bytes for which space is available in
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a terminal input queue.
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.It Li _PC_NAME_MAX
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The maximum number of bytes in a file name.
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.It Li _PC_PATH_MAX
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The maximum number of bytes in a pathname.
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.It Li _PC_PIPE_BUF
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The maximum number of bytes which will be written atomically to a pipe.
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.It Li _PC_CHOWN_RESTRICTED
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Return 1 if appropriate privileges are required for the
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.Xr chown 2
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system call, otherwise 0.
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.It Li _PC_NO_TRUNC
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Return 1 if file names longer than KERN_NAME_MAX are truncated.
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.It Li _PC_VDISABLE
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Returns the terminal character disabling value.
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.El
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.Sh RETURN VALUES
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If the call to
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.Nm pathconf
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or
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.Nm fpathconf
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is not successful, \-1 is returned and
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.Va errno
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is set appropriately.
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Otherwise, if the variable is associated with functionality that does
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not have a limit in the system, \-1 is returned and
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.Va errno
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is not modified.
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Otherwise, the current variable value is returned.
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.Sh ERRORS
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If any of the following conditions occur, the
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.Nm pathconf
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and
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.Nm fpathconf
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functions shall return -1 and set
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.Va errno
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to the corresponding value.
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.Bl -tag -width Er
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.It Bq Er EINVAL
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The value of the
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.Fa name
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argument is invalid.
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.It Bq Er EINVAL
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The implementation does not support an association of the variable
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name with the associated file.
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.El
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.Fn Pathconf
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will fail if:
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.Bl -tag -width ENAMETOOLONGAA
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.It Bq Er ENOTDIR
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A component of the path prefix is not a directory.
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.It Bq Er ENAMETOOLONG
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A component of a pathname exceeded 255 characters,
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or an entire path name exceeded 1023 characters.
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.It Bq Er ENOENT
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The named file does not exist.
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.It Bq Er EACCES
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Search permission is denied for a component of the path prefix.
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.It Bq Er ELOOP
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Too many symbolic links were encountered in translating the pathname.
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.It Bq Er EIO
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An I/O error occurred while reading from or writing to the file system.
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.El
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.Pp
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.Bl -tag -width [EFAULT]
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.Fn Fpathconf
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will fail if:
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.It Bq Er EBADF
|
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.Fa fd
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is not a valid open file descriptor.
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.It Bq Er EIO
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An I/O error occurred while reading from or writing to the file system.
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.El
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.Sh SEE ALSO
|
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.Xr sysctl 3
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.Sh HISTORY
|
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The
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.Nm pathconf
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and
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.Nm fpathconf
|
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functions first appeared in 4.4BSD.
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@ -0,0 +1,165 @@
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|||
.\" Copyright (c) 1983, 1991, 1992, 1993
|
||||
.\" The Regents of the University of California. All rights reserved.
|
||||
.\"
|
||||
.\" Redistribution and use in source and binary forms, with or without
|
||||
.\" modification, are permitted provided that the following conditions
|
||||
.\" are met:
|
||||
.\" 1. Redistributions of source code must retain the above copyright
|
||||
.\" notice, this list of conditions and the following disclaimer.
|
||||
.\" 2. Redistributions in binary form must reproduce the above copyright
|
||||
.\" notice, this list of conditions and the following disclaimer in the
|
||||
.\" documentation and/or other materials provided with the distribution.
|
||||
.\" 3. All advertising materials mentioning features or use of this software
|
||||
.\" must display the following acknowledgement:
|
||||
.\" This product includes software developed by the University of
|
||||
.\" California, Berkeley and its contributors.
|
||||
.\" 4. Neither the name of the University nor the names of its contributors
|
||||
.\" may be used to endorse or promote products derived from this software
|
||||
.\" without specific prior written permission.
|
||||
.\"
|
||||
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
||||
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||||
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||||
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
||||
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||||
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||||
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||||
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||||
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||||
.\" SUCH DAMAGE.
|
||||
.\"
|
||||
.\" @(#)sigaltstack.2 8.1 (Berkeley) 6/4/93
|
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.\"
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.Dd June 4, 1993
|
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.Dt SIGALTSTACK 2
|
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.Os BSD 4.2
|
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.Sh NAME
|
||||
.Nm sigaltstack
|
||||
.Nd set and/or get signal stack context
|
||||
.Sh SYNOPSIS
|
||||
.Fd #include <sys/types.h>
|
||||
.Fd #include <signal.h>
|
||||
.Bd -literal
|
||||
struct sigaltstack {
|
||||
caddr_t ss_sp;
|
||||
long ss_size;
|
||||
int ss_flags;
|
||||
};
|
||||
.Ed
|
||||
.Ft int
|
||||
.Fn sigaltstack "const struct sigaltstack *ss" "struct sigaltstack *oss"
|
||||
.Sh DESCRIPTION
|
||||
.Fn Sigaltstack
|
||||
allows users to define an alternate stack on which signals
|
||||
are to be processed.
|
||||
If
|
||||
.Fa ss
|
||||
is non-zero,
|
||||
it specifies a pointer to and the size of a
|
||||
.Em "signal stack"
|
||||
on which to deliver signals,
|
||||
and tells the system if the process is currently executing
|
||||
on that stack.
|
||||
When a signal's action indicates its handler
|
||||
should execute on the signal stack (specified with a
|
||||
.Xr sigaction 2
|
||||
call), the system checks to see
|
||||
if the process is currently executing on that stack.
|
||||
If the process is not currently executing on the signal stack,
|
||||
the system arranges a switch to the signal stack for the
|
||||
duration of the signal handler's execution.
|
||||
.Pp
|
||||
If
|
||||
.Dv SA_DISABLE
|
||||
is set in
|
||||
.Fa ss_flags ,
|
||||
.Fa ss_sp
|
||||
and
|
||||
.Fa ss_size
|
||||
are ignored and the signal stack will be disabled.
|
||||
Trying to disable an active stack will cause
|
||||
.Nm
|
||||
to return -1 with
|
||||
.Va errno
|
||||
set to
|
||||
.Dv EINVAL .
|
||||
A disabled stack will cause all signals to be
|
||||
taken on the regular user stack.
|
||||
If the stack is later re-enabled then all signals that were specified
|
||||
to be processed on an alternate stack will resume doing so.
|
||||
.Pp
|
||||
If
|
||||
.Fa oss
|
||||
is non-zero, the current signal stack state is returned.
|
||||
The
|
||||
.Fa ss_flags
|
||||
field will contain the value
|
||||
.Dv SA_ONSTACK
|
||||
if the process is currently on a signal stack and
|
||||
.Dv SA_DISABLE
|
||||
if the signal stack is currently disabled.
|
||||
.Sh NOTES
|
||||
The value
|
||||
.Dv SIGSTKSZ
|
||||
is defined to be the number of bytes/chars that would be used to cover
|
||||
the usual case when allocating an alternate stack area.
|
||||
The following code fragment is typically used to allocate an alternate stack.
|
||||
.Bd -literal -offset indent
|
||||
if ((sigstk.ss_sp = malloc(SIGSTKSZ)) == NULL)
|
||||
/* error return */
|
||||
sigstk.ss_size = SIGSTKSZ;
|
||||
sigstk.ss_flags = 0;
|
||||
if (sigaltstack(&sigstk,0) < 0)
|
||||
perror("sigaltstack");
|
||||
.Ed
|
||||
An alternative approach is provided for programs with signal handlers
|
||||
that require a specific amount of stack space other than the default size.
|
||||
The value
|
||||
.Dv MINSIGSTKSZ
|
||||
is defined to be the number of bytes/chars that is required by
|
||||
the operating system to implement the alternate stack feature.
|
||||
In computing an alternate stack size,
|
||||
programs should add
|
||||
.Dv MINSIGSTKSZ
|
||||
to their stack requirements to allow for the operating system overhead.
|
||||
.Pp
|
||||
Signal stacks are automatically adjusted for the direction of stack
|
||||
growth and alignment requirements.
|
||||
Signal stacks may or may not be protected by the hardware and
|
||||
are not ``grown'' automatically as is done for the normal stack.
|
||||
If the stack overflows and this space is not protected
|
||||
unpredictable results may occur.
|
||||
.Sh RETURN VALUES
|
||||
Upon successful completion, a value of 0 is returned.
|
||||
Otherwise, a value of -1 is returned and
|
||||
.Va errno
|
||||
is set to indicate the error.
|
||||
.Sh ERRORS
|
||||
.Fn Sigstack
|
||||
will fail and the signal stack context will remain unchanged
|
||||
if one of the following occurs.
|
||||
.Bl -tag -width [ENOMEM]
|
||||
.It Bq Er EFAULT
|
||||
Either
|
||||
.Fa ss
|
||||
or
|
||||
.Fa oss
|
||||
points to memory that is not a valid part of the process
|
||||
address space.
|
||||
.It Bq Er EINVAL
|
||||
An attempt was made to disable an active stack.
|
||||
.It Bq Er ENOMEM
|
||||
Size of alternate stack area is less than or equal to
|
||||
.Dv MINSIGSTKSZ .
|
||||
.El
|
||||
.Sh SEE ALSO
|
||||
.Xr sigaction 2 ,
|
||||
.Xr setjmp 3
|
||||
.Sh HISTORY
|
||||
The predecessor to
|
||||
.Nm sigaltstack ,
|
||||
the
|
||||
.Fn sigstack
|
||||
system call, appeared in
|
||||
.Bx 4.2 .
|
||||
Loading…
Reference in New Issue