phunix/lib/libkvm/kvm_read.3
David van Moolenbroek 9da227510d Import NetBSD libkvm
Imported with no changes, but not all parts are expected to be
functional.  The libc nlist functionality is enabled for the
purpose of successful linking, although the nlist functionaly has
not been tested on MINIX3 nor is it needed for how we use libkvm.

In terms of function calls: kvm_getproc2, kvm_getargv2,
kvm_getenvv2, and kvm_getlwps are expected to work, whereas
kvm_getproc, kvm_getargv, kvm_getenvv, and kvm_getfiles are not.

Change-Id: I7539209736f1771fc0b7db5e839d2df72f5ac615
2016-01-13 20:32:49 +01:00

94 lines
3.0 KiB
Groff

.\" $NetBSD: kvm_read.3,v 1.8 2003/08/07 16:44:39 agc Exp $
.\"
.\" Copyright (c) 1992, 1993
.\" The Regents of the University of California. All rights reserved.
.\"
.\" This code is derived from software developed by the Computer Systems
.\" Engineering group at Lawrence Berkeley Laboratory under DARPA contract
.\" BG 91-66 and contributed to Berkeley.
.\"
.\" 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. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
.\"
.\" @(#)kvm_read.3 8.1 (Berkeley) 6/4/93
.\"
.Dd June 4, 1993
.Dt KVM_READ 3
.Os
.Sh NAME
.Nm kvm_read ,
.Nm kvm_write
.Nd read or write kernel virtual memory
.Sh LIBRARY
.Lb libkvm
.Sh SYNOPSIS
.In kvm.h
.Ft ssize_t
.Fn kvm_read "kvm_t *kd" "u_long addr" "void *buf" "size_t nbytes"
.Ft ssize_t
.Fn kvm_write "kvm_t *kd" "u_long addr" "const void *buf" "size_t nbytes"
.Sh DESCRIPTION
The
.Fn kvm_read
and
.Fn kvm_write
functions are used to read and write kernel virtual memory (or a crash
dump file).
See
.Fn kvm_open 3
or
.Fn kvm_openfiles 3
for information regarding opening kernel virtual memory and crash dumps.
.Pp
The
.Fn kvm_read
function transfers
.Fa nbytes
bytes of data from
the kernel space address
.Fa addr
to
.Fa buf .
Conversely,
.Fn kvm_write
transfers data from
.Fa buf
to
.Fa addr .
Unlike their SunOS counterparts, these functions cannot be used to
read or write process address spaces.
.Sh RETURN VALUES
Upon success, the number of bytes actually transferred is returned.
Otherwise, -1 is returned.
.Sh SEE ALSO
.Xr kvm 3 ,
.Xr kvm_close 3 ,
.Xr kvm_getargv 3 ,
.Xr kvm_getenvv 3 ,
.Xr kvm_geterr 3 ,
.Xr kvm_getprocs 3 ,
.Xr kvm_nlist 3 ,
.Xr kvm_open 3 ,
.Xr kvm_openfiles 3