1# 2# CDDL HEADER START 3# 4# The contents of this file are subject to the terms of the 5# Common Development and Distribution License, Version 1.0 only 6# (the "License"). You may not use this file except in compliance 7# with the License. 8# 9# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10# or http://www.opensolaris.org/os/licensing. 11# See the License for the specific language governing permissions 12# and limitations under the License. 13# 14# When distributing Covered Code, include this CDDL HEADER in each 15# file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16# If applicable, add the following below this CDDL HEADER, with the 17# fields enclosed by brackets "[]" replaced with your own identifying 18# information: Portions Copyright [yyyy] [name of copyright owner] 19# 20# CDDL HEADER END 21# 22 23Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24Use is subject to license terms. 25 26Copyright 2022 Garrett D'Amore 27 28 291. Introduction 30 31This directory contains source code for sample debugger modules for the Modular 32Debugger (MDB). These modules demonstrate how developers can use the MDB 33programming API to extend the capabilities of MDB itself. MDB is an extensible 34utility for low-level debugging and editing of the live operating system, 35operating system crash dumps, user processes, user process core dumps, and 36object files. For a more detailed description of MDB features and documentation 37for the MDB programming API, refer to the manual, "Solaris Modular Debugger 38Guide". This document is available on-line at http://docs.sun.com. 39 402. Configuration 41 42As the files in this directory are owned by the administrator, you should make 43a copy of this directory to your home directory or other location before you 44begin experimenting with MDB. If you wish to change the configuration, edit 45the CC macro definitions in Makefile.i386 and Makefile.amd64 to point to the 46appropriate pathnames. 47 48The Makefiles contained in this directory are set up to use the C compiler (cc) 49found in your $PATH. These four Makefiles can also be used to define base 50compiler settings for the corresponding instruction set architecture (ISA): 51 52 Makefile.i386 - rules for building 32-bit x86 objects 53 Makefile.amd64 - rules for building 64-bit x86 objects 54 55The Makefile.common file adds common compiler and linker flags to these base 56definitions, and defines the rules for building the example modules. You will 57not need to change any of the definitions here in order to build the examples. 58If you wish to construct additional modules of your own, edit the MODULES macro 59at the top of Makefile.common. For example, if you create a new module source 60file common/mymodule.c, you should change: 61 62< MODULES = example1.so example2.so 63 64to: 65 66> MODULES = example1.so example2.so mymodule.so 67 68and then execute "make". 69 703. Targets 71 72The Makefile in this directory supports the following targets: 73 74 make all (default) - build all modules for the current machine 75 make clean - remove object files from build directories 76 make clobber - remove objects, and modules 77 78To build the example modules, execute "make" in this directory. This will 79execute the default "make all" target. 80 814. Loading Modules 82 83After you successfully compile the example modules, the module object files 84reside in one or more of the i386/, amd64/ subdirectories 85depending on the ISAs supported on your machine. In order to load the example 86modules, you can either use the ::load built-in dcmd with the absolute pathname 87of a given module, or you can adjust the module library path to include the 88directory where your modules are located. This can be done using the ::set -L 89built-in dcmd. For example: 90 91 > ::set -L %o:/usr/demo/mdb/%i 92 > ::load example1 93 94The %o token expands to the old value of the path. The %i token expands to 95the appropriate ISA name. You can restore this setting each time you use 96MDB by adding the ::set directive to your $HOME/.mdbrc file. This file, if 97present, is processed automatically each time you start the debugger. 98 995. Example 1: Echo and Vmstat 100 101The first example module provides the source code for two example loadable 102dcmds. ::simple_echo is a command to echo back its arguments, similar to 103/usr/bin/echo or MDB's built-in ::echo dcmd. ::vminfo is a command to read 104and print the kernel's global virtual memory statistics structure. This 105example introduces the basic structure of an MDB module and demonstrates some 106simple argument processing. In order to use ::vminfo, you will need to apply 107MDB to a crash dump of your system, or to the live kernel. To apply MDB to a 108crash dump, you might execute: 109 110 $ mdb unix.0 vmcore.0 111 112To apply MDB to the live kernel, become super-user and then execute: 113 114 # mdb -k 115 1166. Example 2: Proc Walker and PS 117 118The second example module provides a more realistic example of something you 119might want to do with MDB: print a formatted table of active processes, 120similar to the /usr/bin/ps command or MDB's ::ps dcmd. This example 121introduces the concept of a walker, a set of functions which describe how to 122iterate over a data structure, and them demonstrates how the ::simple_ps 123dcmd can be built using this walker. Using the simple_proc walker, you can 124obtain a listing of kernel proc_t addresses: 125 126 > ::load example2 127 > ::walk simple_proc 128 71690a80 129 7168ee40 130 71611898 131 [ ... ] 132 7103b178 133 7103b888 134 1041ce20 135 136Using the ::simple_ps dcmd you can obtain a formatted listing of processes: 137 138 > ::simple_ps 139 PID COMM 140 285 sh 141 271 mibiisa 142 269 ttymon 143 [ ... ] 144 1457. Packaging and Installation 146 147If you are a software developer, you may wish to develop and deliver MDB 148modules along with your software products in order to facilitate analysis 149of software problems at customer sites. Your completed MDB modules should 150be packaged along with your software and delivered into the appropriate 151MDB module directory. For kernel debugging modules, your module should 152be delivered in one of the following directories: 153 154 /usr/lib/mdb/kvm 155 /usr/platform/`uname -i`/lib/mdb/kvm 156 157and should be named after your kernel module. For example, the "ip" kernel 158module has a debugging module named "ip.so". 159