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) 49and lint utility found in your $PATH. These four Makefiles can also be used 50to define base compiler settings for the corresponding instruction set 51architecture (ISA): 52 53 Makefile.i386 - rules for building 32-bit x86 objects 54 Makefile.amd64 - rules for building 64-bit x86 objects 55 56The Makefile.common file adds common compiler and linker flags to these base 57definitions, and defines the rules for building the example modules. You will 58not need to change any of the definitions here in order to build the examples. 59If you wish to construct additional modules of your own, edit the MODULES macro 60at the top of Makefile.common. For example, if you create a new module source 61file common/mymodule.c, you should change: 62 63< MODULES = example1.so example2.so 64 65to: 66 67> MODULES = example1.so example2.so mymodule.so 68 69and then execute "make". 70 713. Targets 72 73The Makefile in this directory supports the following targets: 74 75 make all (default) - build all modules for the current machine 76 make clean - remove object files from build directories 77 make clean.lint - remove lint files from build directories 78 make clobber - remove objects, modules, and lint files 79 make lint - run lint against each example module 80 81To build the example modules, execute "make" in this directory. This will 82execute the default "make all" target. 83 844. Loading Modules 85 86After you successfully compile the example modules, the module object files 87reside in one or more of the i386/, amd64/ subdirectories 88depending on the ISAs supported on your machine. In order to load the example 89modules, you can either use the ::load built-in dcmd with the absolute pathname 90of a given module, or you can adjust the module library path to include the 91directory where your modules are located. This can be done using the ::set -L 92built-in dcmd. For example: 93 94 > ::set -L %o:/usr/demo/mdb/%i 95 > ::load example1 96 97The %o token expands to the old value of the path. The %i token expands to 98the appropriate ISA name. You can restore this setting each time you use 99MDB by adding the ::set directive to your $HOME/.mdbrc file. This file, if 100present, is processed automatically each time you start the debugger. 101 1025. Example 1: Echo and Vmstat 103 104The first example module provides the source code for two example loadable 105dcmds. ::simple_echo is a command to echo back its arguments, similar to 106/usr/bin/echo or MDB's built-in ::echo dcmd. ::vminfo is a command to read 107and print the kernel's global virtual memory statistics structure. This 108example introduces the basic structure of an MDB module and demonstrates some 109simple argument processing. In order to use ::vminfo, you will need to apply 110MDB to a crash dump of your system, or to the live kernel. To apply MDB to a 111crash dump, you might execute: 112 113 $ mdb unix.0 vmcore.0 114 115To apply MDB to the live kernel, become super-user and then execute: 116 117 # mdb -k 118 1196. Example 2: Proc Walker and PS 120 121The second example module provides a more realistic example of something you 122might want to do with MDB: print a formatted table of active processes, 123similar to the /usr/bin/ps command or MDB's ::ps dcmd. This example 124introduces the concept of a walker, a set of functions which describe how to 125iterate over a data structure, and them demonstrates how the ::simple_ps 126dcmd can be built using this walker. Using the simple_proc walker, you can 127obtain a listing of kernel proc_t addresses: 128 129 > ::load example2 130 > ::walk simple_proc 131 71690a80 132 7168ee40 133 71611898 134 [ ... ] 135 7103b178 136 7103b888 137 1041ce20 138 139Using the ::simple_ps dcmd you can obtain a formatted listing of processes: 140 141 > ::simple_ps 142 PID COMM 143 285 sh 144 271 mibiisa 145 269 ttymon 146 [ ... ] 147 1487. Packaging and Installation 149 150If you are a software developer, you may wish to develop and deliver MDB 151modules along with your software products in order to facilitate analysis 152of software problems at customer sites. Your completed MDB modules should 153be packaged along with your software and delivered into the appropriate 154MDB module directory. For kernel debugging modules, your module should 155be delivered in one of the following directories: 156 157 /usr/lib/mdb/kvm 158 /usr/platform/`uname -i`/lib/mdb/kvm 159 160and should be named after your kernel module. For example, the "ip" kernel 161module has a debugging module named "ip.so". 162