$OpenBSD: copy.9,v 1.18 2023/01/06 19:10:18 miod Exp $
$NetBSD: copy.9,v 1.2 1996/01/09 03:23:04 thorpej Exp $

Copyright (c) 1996 Jason R. Thorpe.
All rights reserved.

This code is derived from software contributed by Kenneth Stailey.

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 for the NetBSD Project
by Jason R. Thorpe.
4. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.

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.Dd $Mdocdate: November 23 2015 $ .Dt COPYIN 9 .Os .Sh NAME .Nm copyin , .Nm copyout , .Nm copyinstr , .Nm copyoutstr , .Nm kcopy .Nd kernel copy functions .Sh SYNOPSIS n sys/types.h n sys/systm.h .Ft int .Fn copyin "const void *uaddr" "void *kaddr" "size_t len" .Ft int .Fn copyout "const void *kaddr" "void *uaddr" "size_t len" .Ft int .Fn copyinstr "const void *uaddr" "void *kaddr" "size_t len" "size_t *done" .Ft int .Fn copyoutstr "const void *kaddr" "void *uaddr" "size_t len" "size_t *done" .Ft int .Fn kcopy "const void *kfaddr" "void *kdaddr" "size_t len" .Sh DESCRIPTION The .Nm functions are designed to copy contiguous data from one address to another. All but .Fn kcopy copy data from user-space to kernel-space or vice-versa.

p The .Nm routines provide the following functionality: l -tag -width "copyoutstr()" t Fn copyin Copies .Fa len bytes of data from the user-space address .Fa uaddr to the kernel-space address .Fa kaddr . t Fn copyout Copies .Fa len bytes of data from the kernel-space address .Fa kaddr to the user-space address .Fa uaddr . t Fn copyinstr Copies a null-terminated string, at most .Fa len bytes long, from user-space address .Fa uaddr to kernel-space address .Fa kaddr . The number of bytes actually copied, including the terminating null, is returned in .Fa *done , if .Fa done is not .Dv NULL . t Fn copyoutstr Copies a null-terminated string, at most .Fa len bytes long, from kernel-space address .Fa kaddr to user-space address .Fa uaddr . The number of bytes actually copied, including the terminating null, is returned in .Fa *done , if .Fa done is not .Dv NULL . t Fn kcopy Copies .Fa len bytes of data from the kernel-space address .Fa kfaddr to the kernel-space address .Fa kdaddr . .El .Sh RETURN VALUES The .Nm functions return 0 on success or .Er EFAULT if a bad address is encountered. In addition, the .Fn copyinstr and .Fn copyoutstr functions return .Er ENAMETOOLONG if the string is longer than .Fa len bytes. .Sh SEE ALSO