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.\" $MidnightBSD$ |
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.\" Copyright (c) 1992, 1993 |
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.\" The Regents of the University of California. All rights reserved. |
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.\" |
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.\" This code is derived from software developed by the Computer Systems |
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.\" Engineering group at Lawrence Berkeley Laboratory under DARPA contract |
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.\" BG 91-66 and contributed to Berkeley. |
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.\" |
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.\" Redistribution and use in source and binary forms, with or without |
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.\" modification, are permitted provided that the following conditions |
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.\" are met: |
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.\" 1. Redistributions of source code must retain the above copyright |
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.\" notice, this list of conditions and the following disclaimer. |
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.\" 2. Redistributions in binary form must reproduce the above copyright |
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.\" notice, this list of conditions and the following disclaimer in the |
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.\" documentation and/or other materials provided with the distribution. |
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.\" 4. Neither the name of the University nor the names of its contributors |
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.\" may be used to endorse or promote products derived from this software |
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.\" without specific prior written permission. |
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.\" |
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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.\" SUCH DAMAGE. |
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.\" |
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.\" @(#)kvm_read.3 8.1 (Berkeley) 6/4/93 |
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.\" $FreeBSD: stable/10/lib/libkvm/kvm_read.3 165888 2007-01-08 17:35:36Z imp $ |
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.\" |
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.Dd June 4, 1993 |
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.Dt KVM_READ 3 |
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.Os |
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.Sh NAME |
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.Nm kvm_read , |
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.Nm kvm_write |
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.Nd read or write kernel virtual memory |
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.Sh LIBRARY |
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.Lb libkvm |
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.Sh SYNOPSIS |
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.In kvm.h |
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.Ft ssize_t |
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.Fn kvm_read "kvm_t *kd" "unsigned long addr" "void *buf" "size_t nbytes" |
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.Ft ssize_t |
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.Fn kvm_write "kvm_t *kd" "unsigned long addr" "const void *buf" "size_t nbytes" |
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.Sh DESCRIPTION |
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The |
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.Fn kvm_read |
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and |
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.Fn kvm_write |
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functions are used to read and write kernel virtual memory (or a crash |
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dump file). |
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See |
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.Fn kvm_open 3 |
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or |
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.Fn kvm_openfiles 3 |
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for information regarding opening kernel virtual memory and crash dumps. |
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.Pp |
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The |
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.Fn kvm_read |
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function transfers |
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.Fa nbytes |
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bytes of data from |
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the kernel space address |
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.Fa addr |
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to |
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.Fa buf . |
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Conversely, |
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.Fn kvm_write |
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transfers data from |
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.Fa buf |
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to |
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.Fa addr . |
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Unlike their SunOS counterparts, these functions cannot be used to |
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read or write process address spaces. |
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.Sh RETURN VALUES |
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Upon success, the number of bytes actually transferred is returned. |
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Otherwise, -1 is returned. |
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.Sh SEE ALSO |
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.Xr kvm 3 , |
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.Xr kvm_close 3 , |
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.Xr kvm_getargv 3 , |
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.Xr kvm_getenvv 3 , |
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.Xr kvm_geterr 3 , |
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.Xr kvm_getprocs 3 , |
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.Xr kvm_nlist 3 , |
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.Xr kvm_open 3 , |
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.Xr kvm_openfiles 3 |
