7f911abe54
- Add a kvaddr_type to represent kernel virtual addresses instead of unsigned long. - Add a struct kvm_nlist which is a stripped down version of struct nlist that uses kvaddr_t for n_value. - Add a kvm_native() routine that returns true if an open kvm descriptor is for a native kernel and memory image. - Add a kvm_open2() function similar to kvm_openfiles(). It drops the unused 'swapfile' argument and adds a new function pointer argument for a symbol resolving function. Native kernels still use _fdnlist() from libc to resolve symbols if a resolver function is not supplied, but cross kernels require a resolver. - Add a kvm_nlist2() function similar to kvm_nlist() except that it uses struct kvm_nlist instead of struct nlist. - Add a kvm_read2() function similar to kvm_read() except that it uses kvaddr_t instead of unsigned long for the kernel virtual address. - Add a new kvm_arch switch of routines needed by a vmcore backend. Each backend is responsible for implementing kvm_read2() for a given vmcore format. - Use libelf to read headers from ELF kernels and cores (except for powerpc cores). - Add internal helper routines for the common page offset hash table used by the minidump backends. - Port all of the existing kvm backends to implement a kvm_arch switch and to be cross-friendly by using private constants instead of ones that vary by platform (e.g. PAGE_SIZE). Static assertions are present when a given backend is compiled natively to ensure the private constants match the real ones. - Enable all of the existing vmcore backends on all platforms. This means that libkvm on any platform should be able to perform KVA translation and read data from a vmcore of any platform. Tested on: amd64, i386, sparc64 (marius) Differential Revision: https://reviews.freebsd.org/D3341
107 lines
3.3 KiB
Groff
107 lines
3.3 KiB
Groff
.\" 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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.\" $FreeBSD$
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.\"
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.Dd November 27, 2015
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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_read2 ,
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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_read2 "kvm_t *kd" "kvaddr_t 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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.Fn kvm_read2 ,
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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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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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and
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.Fn kvm_read2
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functions transfer
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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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.Pp
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The
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.Fn kvm_read2
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function uses a different type
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.Pq Vt kvaddr_t
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for the
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.Fa addr
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argument to allow use of addresses larger than
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.Dv ULONG_MAX
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when examining non-native kernel images.
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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
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