bsd/man/man2/munmap.2

   1 .\"     $NetBSD: munmap.2,v 1.5 1995/02/27 12:35:03 cgd Exp $
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  34 .\"     @(#)munmap.2    8.2 (Berkeley) 4/15/94
  35 .\"
  36 .Dd April 15, 1994
  37 .Dt MUNMAP 2
  38 .Os
  39 .Sh NAME
  40 .Nm munmap
  41 .Nd remove a mapping
  42 .Sh SYNOPSIS
  43 .Fd #include <sys/mman.h>
  44 .Ft int
  45 .Fo munmap
  46 .Fa "void *addr"
  47 .Fa "size_t len"
  48 .Fc
  49 .Sh DESCRIPTION
  50 The
  51 .Fn munmap
  52 system call
  53 deletes the mappings for the specified address range,
  54 causing further references to addresses within the range
  55 to generate invalid memory references.
  56 .Sh RETURN VALUES
  57 Upon successful completion,
  58 .Nm munmap
  59 returns zero.
  60 Otherwise, a value of -1 is returned and
  61 .Va errno
  62 is set to indicate the error.
  63 .Sh ERRORS
  64 .Fn Munmap
  65 will fail if:
  66 .Bl -tag -width Er
  67 .\" ===========
  68 .It Bq Er EINVAL
  69 The
  70 .Fa addr
  71 parameter was not page aligned (i.e., a multiple of the page size).
  72 .\" ===========
  73 .It Bq Er EINVAL
  74 The
  75 .Fa len
  76 parameter was negative or zero.
  77 .\" ===========
  78 .It Bq Er EINVAL
  79 Some part of the region being unmapped is not part of the currently
  80 valid address space.
  81 .El
  82 .Sh LEGACY SYNOPSIS
  83 .Fd #include <sys/types.h>
  84 .Fd #include <sys/mman.h>
  85 .Pp
  86 The include file
  87 .In sys/types.h
  88 is necessary.
  89 .Pp
  90 .Ft int
  91 .br
  92 .Fo munmap
  93 .Fa "caddr_t addr"
  94 .Fa "size_t len"
  95 .Fc ;
  96 .Pp
  97 The type of
  98 .Fa addr
  99 has changed.
 100 .Sh "SEE ALSO"
 101 .Xr getpagesize 3 ,
 102 .Xr msync 2 ,
 103 .Xr munmap 2 ,
 104 .Xr mprotect 2 ,
 105 .Xr madvise 2 ,
 106 .Xr mincore 2 ,
 107 .Xr compat 5
 108 .Sh HISTORY
 109 The
 110 .Fn munmap
 111 function first appeared in 4.4BSD.