NetBSD/share/man/man9/kmem_alloc.9

85 lines
3.1 KiB
Groff

.\" $NetBSD: kmem_alloc.9,v 1.2 2006/06/25 13:24:45 wiz Exp $
.\"
.\" Copyright (c)2006 YAMAMOTO Takashi,
.\" All rights reserved.
.\"
.\" 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.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" ------------------------------------------------------------
.Dd June 25, 2006
.Dt KMEM_ALLOC 9
.Os
.\" ------------------------------------------------------------
.Sh NAME
.Nm kmem_alloc
.Nd allocate kernel wired memory
.\" ------------------------------------------------------------
.Sh SYNOPSIS
.In sys/kmem.h
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.Ft void *
.Fn kmem_alloc \
"size_t size" "km_flag_t kmflags"
.\" ------------------------------------------------------------
.Sh DESCRIPTION
.Fn kmem_alloc
allocates kernel wired memory.
It takes the following arguments.
.Bl -tag -width kmflags
.It Fa size
Specify the size of allocation in bytes.
.It Fa kmflags
Either of the following:
.Bl -tag -width KM_NOSLEEP -compact
.It KM_SLEEP
Can sleep until enough memory is available.
.It KM_NOSLEEP
Don't sleep.
Immediately return
.Dv NULL
if there is not enough memory available.
.El
.El
.Pp
The contents of allocated memory are uninitialized.
.\" ------------------------------------------------------------
.Sh RETURN VALUES
.Fn kmem_alloc
returns a pointer to allocated memory on success.
Otherwise, it returns
.Dv NULL .
.\" ------------------------------------------------------------
.Sh SEE ALSO
.Xr intro 9 ,
.Xr kmem_free 9 ,
.Xr kmem_zalloc 9 ,
.Xr malloc 9
.\" ------------------------------------------------------------
.Sh CAVEATS
.Fn kmem_alloc
can not be used from interrupt context.
.\" ------------------------------------------------------------
.Sh SECURITY CONSIDERATION
As the allocated memory is uninitialized, it can contain security-sensitive
data left by its previous user.
It's the caller's responsibility not to expose it to the world.