xnu-7195.101.1.tar.gz

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.\"
.\"	$NetBSD: copy.9,v 1.2 1996/01/09 03:23:04 thorpej Exp $
.\"
.\" Copyright (c) 1996 Jason R. Thorpe.
.\" All rights reserved.
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.\" This code is derived from software contributed by Kenneth Stailey.
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.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed for the NetBSD Project
.\"	by Jason R. Thorpe.
.\" 4. The name of the author may not be used to endorse or promote products
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.\" $FreeBSD: src/share/man/man9/copy.9,v 1.6.2.5 2001/12/17 11:30:18 ru Exp $
.\"
.Dd October 2, 2008
.Dt COPY 9
.Os
.Sh NAME
.Nm copy ,
.Nm copyin ,
.Nm copyinstr ,
.Nm copyout ,
.Nm copystr
.Nd kernel copy functions
.Sh SYNOPSIS
.In sys/types.h
.In sys/systm.h
.Ft int
.Fo copyin
.Fa "const void *uaddr"
.Fa "void *kaddr"
.Fa "size_t len"
.Fc
.Ft int
.Fo copyinstr
.Fa "const void *uaddr"
.Fa "void *kaddr"
.Fa "size_t len"
.Fa "size_t *done"
.Fc
.Ft int
.Fo copyout
.Fa "const void *kaddr"
.Fa "void *uaddr"
.Fa "size_t len"
.Fc
.\" .Ft int
.\" .Fn copyoutstr
.\" .Fa "const void *kaddr"
.\" .Fa "void *uaddr"
.\" .Fa "size_t len"
.\" .Fa "size_t *done"
.\" .Fc
.Ft int
.Fo copystr
.Fa "const void *kfaddr"
.Fa "void *kdaddr"
.Fa "size_t len"
.Fa "size_t *done"
.Fc
.Sh DESCRIPTION
The
.Nm
functions are designed to copy contiguous data from one address
to another.  All but
.Fn copystr
copy data from user-space to kernel-space or vice-versa.
.Pp
The
.Nm
routines provide the following functionality:
.Bl -tag -width "copyoutstr()"
.\" ========
.It Fn copyin
Copies
.Pa len
bytes of data from the user-space address
.Pa uaddr
to the kernel-space address
.Pa kaddr .
.\" ========
.It Fn copyinstr
Copies a NUL-terminated string, at most
.Pa len
bytes long, from user-space address
.Pa uaddr
to kernel-space address
.Pa kaddr .
The number of bytes actually copied, including the terminating
NUL, is returned in
.Pa *done .
.\" ========
.It Fn copyout
Copies
.Pa len
bytes of data from the kernel-space address
.Pa kaddr
to the user-space address
.Pa uaddr .
.\" ========
.\" .It Fn copyoutstr
.\" Copies a NUL-terminated string, at most
.\" bytes long, from kernel-space address
.\" .Pa kaddr
.\" to user-space address
.\" .Pa uaddr .
.\" The number of bytes actually copied, including the terminating
.\" NUL, is returned in
.\" .Pa *done .
.\" ========
.It Fn copystr
Copies a NUL-terminated string, at most
.Pa len
bytes long, from kernel-space address
.Pa kfaddr
to kernel-space address
.Pa kdaddr .
The number of bytes actually copied, including the terminating
NUL, is returned in
.Pa *done .
.El
.Sh RETURN VALUES
The
.Nm
functions return 0 on success or the following error on failure:
.\" ========
.Bl -tag -width Er
.It Bq EFAULT
If a bad address is encountered. When this error is returned, the contents of the destination buffer (
.Fa *kaddr
for
.Fn copyin ,
.Fn copyinstr ,
and
.Fn copystr ;
.Fa *uaddr
for
.Fn copyout )
are undefined. For
.Fn copyinstr
and
.Fn copystr ,
the contents of the
.Fa *done
parameter are also undefined on a return of EFAULT.
.El
.Pp
In addition to EFAULT,
.\" .Fn copystr ,
.\" .Fn copyinstr ,
.\" and
.\" .Fn copyoutstr
.Fn copystr
and
.Fn copyinstr
on failure will return:
.\" ========
.Bl -tag -width Er
.It Bq ENAMETOLONG
When the string is longer than
.Pa len
bytes. On this error return, the destination buffer is not null-terminated, but the
.Fa *done
parameter is maintained.
.EL
.Sh SEE ALSO
.Xr fetch 9 ,
.Xr store 9