110 lines
4.1 KiB
Groff
110 lines
4.1 KiB
Groff
.\" $NetBSD: kvm.3,v 1.4 1998/02/06 05:41:59 perry 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. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. 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.3 8.1 (Berkeley) 6/4/93
|
|
.\"
|
|
.Dd June 4, 1993
|
|
.Dt KVM 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm kvm
|
|
.Nd kernel memory interface
|
|
.Sh LIBRARY
|
|
.Lb libkvm
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Xr kvm 3
|
|
library provides a uniform interface for accessing kernel virtual memory
|
|
images, including live systems and crashdumps.
|
|
Access to live systems is via
|
|
.Pa /dev/mem
|
|
while crashdumps can be examined via the core file generated by
|
|
.Xr savecore 8 .
|
|
The interface behaves identically in both cases.
|
|
Memory can be read and written, kernel symbol addresses can be
|
|
looked up efficiently, and information about user processes can
|
|
be gathered.
|
|
.Pp
|
|
.Fn kvm_open
|
|
is first called to obtain a descriptor for all subsequent calls.
|
|
.Sh COMPATIBILITY
|
|
The kvm interface was first introduced in SunOS. A considerable
|
|
number of programs have been developed that use this interface,
|
|
making backward compatibility highly desirable.
|
|
In most respects, the Sun kvm interface is consistent and clean.
|
|
Accordingly, the generic portion of the interface (i.e.,
|
|
.Fn kvm_open ,
|
|
.Fn kvm_close ,
|
|
.Fn kvm_read ,
|
|
.Fn kvm_write ,
|
|
and
|
|
.Fn kvm_nlist )
|
|
has been incorporated into the
|
|
.Bx
|
|
interface. Indeed, many kvm
|
|
applications (i.e., debuggers and statistical monitors) use only
|
|
this subset of the interface.
|
|
.Pp
|
|
The process interface was not kept. This is not a portability
|
|
issue since any code that manipulates processes is inherently
|
|
machine dependent.
|
|
.Pp
|
|
Finally, the Sun kvm error reporting semantics are poorly defined.
|
|
The library can be configured either to print errors to stderr automatically,
|
|
or to print no error messages at all.
|
|
In the latter case, the nature of the error cannot be determined.
|
|
To overcome this, the
|
|
.Bx
|
|
interface includes a
|
|
routine,
|
|
.Xr kvm_geterr 3 ,
|
|
to return (not print out) the error message
|
|
corresponding to the most recent error condition on the
|
|
given descriptor.
|
|
.Sh SEE ALSO
|
|
.Xr kvm_close 3 ,
|
|
.Xr kvm_getargv 3 ,
|
|
.Xr kvm_getenvv 3 ,
|
|
.Xr kvm_geterr 3 ,
|
|
.Xr kvm_getloadavg 3 ,
|
|
.Xr kvm_getprocs 3 ,
|
|
.Xr kvm_nlist 3 ,
|
|
.Xr kvm_open 3 ,
|
|
.Xr kvm_openfiles 3 ,
|
|
.Xr kvm_read 3 ,
|
|
.Xr kvm_write 3
|