bsd/man/man2/mprotect.2

   1 .\"     $NetBSD: mprotect.2,v 1.6 1995/10/12 15:41:08 jtc Exp $
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  34 .\"     @(#)mprotect.2  8.1 (Berkeley) 6/9/93
  35 .\"
  36 .Dd June 9, 1993
  37 .Dt MPROTECT 2
  38 .Os
  39 .Sh NAME
  40 .Nm mprotect
  41 .Nd control the protection of pages
  42 .Sh SYNOPSIS
  43 .Fd #include <sys/mman.h>
  44 .Ft int
  45 .Fo mprotect
  46 .Fa "void *addr"
  47 .Fa "size_t len"
  48 .Fa "int prot"
  49 .Fc
  50 .Sh DESCRIPTION
  51 The
  52 .Fn mprotect
  53 system call
  54 changes the specified pages to have protection
  55 .Fa prot .
  56 Not all implementations will guarantee protection on a page basis;
  57 the granularity of protection changes may be as large as an entire region.
  58 .Sh RETURN VALUES
  59 Upon successful completion,
  60 a value of 0 is returned.
  61 Otherwise, a value of -1 is returned and
  62 .Va errno
  63 is set to indicate the error.
  64 .Sh ERRORS
  65 .Fn mprotect
  66 will fail if:
  67 .Bl -tag -width Er
  68 .\" ===========
  69 .It Bq Er EACCES
  70 The requested protection conflicts with
  71 the access permissions of the process
  72 on the specified address range.
  73 .\" ===========
  74 .\" .It Bq Er EAGAIN
  75 .\" Insufficient memory resources exist to allow locking a private page
  76 .\" under PROT_WRITE.
  77 .\" ===========
  78 .It Bq Er EINVAL
  79 .Fa addr
  80 is not a multiple of the page size.
  81 .\" ===========
  82 .\" .It Bq Er ENOMEM
  83 .\" The specified address range is outside of the address range
  84 .\" of the process or includes an unmapped page.
  85 .\" ===========
  86 .It Bq Er ENOTSUP
  87 The combination of accesses requested in
  88 .Fa prot
  89 is not supported.
  90 .El
  91 .Sh LEGACY SYNOPSIS
  92 .Fd #include <sys/types.h>
  93 .Fd #include <sys/mman.h>
  94 .Pp
  95 The include file
  96 .In sys/types.h
  97 is necessary.
  98 .Pp
  99 .Ft int
 100 .br
 101 .Fo mprotect
 102 .Fa "caddr_t addr"
 103 .Fa "size_t len"
 104 .Fa "int prot"
 105 .Fc ;
 106 .Pp
 107 The type of
 108 .Fa addr
 109 has changed.
 110 .Sh SEE ALSO
 111 .Xr madvise 2 ,
 112 .Xr mincore 2 ,
 113 .Xr msync 2 ,
 114 .Xr munmap 2 ,
 115 .Xr compat 5
 116 .Sh HISTORY
 117 The
 118 .Fn mprotect
 119 function first appeared in 4.4BSD.