e4fc1154a4
Linux compat. Add code to enforce alignment of the new location. Special thanks to wizd for helping with the man page.
94 lines
2.8 KiB
Groff
94 lines
2.8 KiB
Groff
.\" $NetBSD: mremap.2,v 1.1 2007/07/17 17:42:08 joerg Exp $
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.\"
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.\" Copyright (c) 2007 Thomas Klausner and Joerg Sonnenberger
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" 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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.\" ------------------------------------------------------------
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.Dd July 6, 2007
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.Dt MREMAP 2
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.Os
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.Sh NAME
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.Nm mremap
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.Nd re-map a virtual memory address
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.\" ------------------------------------------------------------
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In sys/mman.h
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.Ft void *
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.Fn mremap "void *oldp" "size_t oldsize" "void *newp" "size_t newsize" \
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"int flags"
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.\" ------------------------------------------------------------
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.Sh DESCRIPTION
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The
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.Fn mremap
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function resizes the mapped range (see
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.Xr mmap 2 )
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starting at
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.Ar oldp
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and having size
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.Ar oldsize
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to
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.Ar newsize .
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The following arguments can be
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.Dv OR Ap ed
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together in the
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.Ar flags
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argument:
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.Bl -tag -width XXMAPXALIGNEDXnXX
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.It Dv MAP_ALIGNED Ns Pq Ar n
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The allocation should be aligned to the given boundary, i.e. ensure
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that the lowest
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.Ar n
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bits of the address are zero.
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The parameter
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.Ar n
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should be the base 2 logarithm of the desired alignment (e.g., to
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request alignment to 16K, use 14 as the value for n).
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The alignment must be equal to or greater than the platform's page
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size as returned by
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.Xr sysconf 3
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with the
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.Dv _SC_PAGESIZE
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request.
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.It Dv MAP_FIXED
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.Ar newp
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is tried and
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.Fn mremap
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fails if that address can't be used as new base address for the range.
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Otherwise,
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.Ar oldp
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and
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.Ar newp
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are used as hints for the position, factoring in the given alignment.
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.El
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.Sh RETURN VALUES
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.Fn mremap
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returns the new address or
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.Dv MAP_FAILED ,
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if the remap failed.
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.Sh SEE ALSO
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.Xr mmap 2 ,
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.Xr munmap 2
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