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diff --git a/usr/src/man/man1/mdb.1 b/usr/src/man/man1/mdb.1 new file mode 100644 index 0000000000..380c868add --- /dev/null +++ b/usr/src/man/man1/mdb.1 @@ -0,0 +1,5107 @@ +'\" te +.\" Copyright (c) 2005, Sun Microsystems, Inc. All Rights Reserved. +.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License. +.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License. +.\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] +.TH mdb 1 "30 Nov 2005" "SunOS 5.11" "User Commands" +.SH NAME +mdb \- modular debugger +.SH SYNOPSIS +.LP +.nf +\fBmdb\fR [\fB-fkmuwyAFKMSUW\fR] [\(+-o \fIoption\fR] [\fB-p\fR \fIpid\fR] [\fB-s\fR \fIdistance\fR] + [\fB-I\fR \fIpath\fR] [\fB-L\fR \fIpath\fR] [\fB-P\fR \fIprompt\fR] [\fB-R\fR \fIroot\fR] + [\fB-V\fR \fIdis-version\fR] [object [core] | core | suffix] +.fi + +.SH DESCRIPTION +.SS "Introduction" +.sp +.LP +The \fBmdb\fR utility is an extensible utility for low-level debugging and +editing of the live operating system, operating system crash dumps, user +processes, user process core dumps, and object files. For a more detailed +description of \fBmdb\fR features, refer to the manual, \fISolaris Modular +Debugger Guide\fR. +.sp +.LP +Debugging is the process of analyzing the execution and state of a software +program in order to remove defects. Traditional debugging tools provide +facilities for execution control so that programmers can re-execute programs in +a controlled environment and display the current state of program data or +evaluate expressions in the source language used to develop the program. +.sp +.LP +Unfortunately, these techniques are often inappropriate for debugging complex +software systems such as an operating system, where bugs might not be +reproducible and program state is massive and distributed, for programs that +are highly optimized, have had their debug information removed, or are +themselves low-level debugging tools, or for customer situations where the +developer can only access post-mortem information. +.sp +.LP +\fBmdb\fR provides a completely customizable environment for debugging these +programs and scenarios, including a dynamic module facility that programmers +can use to implement their own debugging commands to perform program-specific +analysis. Each \fBmdb\fR module can be used to examine the program in several +different contexts, including live and post-mortem. +.SS "Definitions" +.sp +.LP +The \fItarget\fR is the program being inspected by the debugger. \fBmdb\fR +currently provides support for the following types of targets: user processes, +user process core files, the live operating system (via \fB/dev/kmem\fR and +\fB/dev/ksyms\fR), operating system crash dumps, user process images recorded +inside an operating system crash dump, \fBELF\fR object files, and raw binary +files. Each target exports a standard set of properties, including one or more +address spaces, one or more symbol tables, a set of load objects, and a set of +threads that can be examined using the debugger commands described below. +.sp +.LP +A debugger command, or \fIdcmd\fR (pronounced dee-command) in \fBmdb\fR +terminology, is a routine in the debugger that can access any of the properties +of the current target. \fBmdb\fR parses commands from standard input, and then +executes the corresponding dcmds. Each dcmd can also accept a list of string or +numerical arguments, as shown in the syntax description below. \fBmdb\fR +contains a set of built-in dcmds, described below, that are always available. +You can also extend the capabilities of \fBmdb\fR itself by writing your own +dcmds, as described in the \fISolaris Modular Debugger Guide\fR. +.sp +.LP +A \fIwalker\fR is a set of routines that describe how to walk, or iterate, +through the elements of a particular program data structure. A walker +encapsulates the data structure's implementation from dcmds and from \fBmdb\fR +itself. You can use walkers interactively, or use them as a primitive to build +other dcmds or walkers. As with dcmds, you can extend \fBmdb\fR by implementing +your own walkers as part of a debugger module. +.sp +.LP +A debugger module, or \fIdmod\fR (pronounced dee-mod), is a dynamically loaded +library containing a set of dcmds and walkers. During initialization, \fBmdb\fR +attempts to load dmods corresponding to the load objects present in the target. +You can subsequently load or unload dmods at any time while running \fBmdb\fR. +\fBmdb\fR ships with a set of standard dmods for debugging the Solaris kernel. +The \fISolaris Modular Debugger Guide\fR contains more information on +developing your own debugger modules. +.sp +.LP +A \fImacro file\fR is a text file containing a set of commands to execute. +Macro files are typically used to automate the process of displaying a simple +data structure. \fBmdb\fR provides complete backward compatibility for the +execution of macro files written for \fBadb\fR(1), and the Solaris installation +includes a set of macro files for debugging the Solaris kernel that can be used +with either tool. +.SS "Syntax" +.sp +.LP +The debugger processes commands from standard input. If standard input is a +terminal, \fBmdb\fR provides terminal editing capabilities. \fBmdb\fR can also +process commands from macro files and from dcmd pipelines, described below. The +language syntax is designed around the concept of computing the value of an +expression (typically a memory address in the target), and then applying a dcmd +to that address. The current address location is referred to as \fIdot\fR, and +its value is referenced using ``.''. +.sp +.LP +A \fImetacharacter\fR is one of the following characters: +.sp +.in +2 +.nf +[ ] | ! / \e ? = > $ : ; + \fINEWLINE\fR \fISPACE\fR \fITAB\fR +.fi +.in -2 +.sp + +.sp +.LP +A \fIblank\fR is a \fITAB\fR or a \fISPACE\fR. A \fIword\fR is a sequence of +characters separated by one or more non-quoted metacharacters. Some of the +metacharacters only function as delimiters in certain contexts, as described +below. An \fIidentifier\fR is a sequence of letters, digits, underscores, +periods, or backquotes beginning with a letter, underscore, or period. +Identifiers are used as the names of symbols, variables, dcmds, and walkers. +Commands are delimited by a \fINEWLINE\fR or semicolon ( \fB;\fR ). +.sp +.LP +A dcmd is denoted by one of the following words or metacharacters: +.sp +.in +2 +.nf +/ \e ? = > $character :character ::identifier +.fi +.in -2 +.sp + +.sp +.LP +dcmds named by metacharacters or prefixed by a single \fB$\fR or \fB:\fR are +provided as built-in operators, and implement complete compatibility with the +command set of the legacy \fBadb\fR(1) utility. Once a dcmd has been parsed, +the \fB/\fR, \fB\e\fR, \fB?\fR, \fB=\fR, \fB>\fR, \fB$\fR, and \fB:\fR +characters are no longer recognized as metacharacters until the termination of +the argument list. +.sp +.LP +A \fIsimple-command\fR is a dcmd followed by a sequence of zero or more +blank-separated words. The words are passed as arguments to the invoked dcmd, +except as specified under \fBQuoting and Arithmetic Expansion\fR below. Each +dcmd returns an exit status that indicates it was either successful, failed, or +was invoked with invalid arguments. +.sp +.LP +A \fIpipeline\fR is a sequence of one or more simple commands separated by +\fB|\fR. Unlike the shell, dcmds in \fBmdb\fR pipelines are not executed as +separate processes. After the pipeline has been parsed, each dcmd is invoked in +order from left to right. Each dcmd's output is processed and stored as +described under \fBdcmd Pipelines\fR below. Once the left-hand dcmd is +complete, its processed output is used as input for the next dcmd in the +pipeline. If any dcmd does not return a successful exit status, the pipeline is +aborted. +.sp +.LP +An \fIexpression\fR is a sequence of words that is evaluated to compute a +64-bit unsigned integer value. The words are evaluated using the rules +described under \fBArithmetic Expansion\fR below. +.SS "Commands" +.sp +.LP +A \fIcommand\fR is one of the following: +.sp +.ne 2 +.mk +.na +\fB\fIpipeline\fR [\fB!\fR \fIword\fR .\|.\|.] [ \fB;\fR ]\fR +.ad +.sp .6 +.RS 4n +A simple-command or pipeline can be optionally suffixed with the \fB!\fR +character, indicating that the debugger should open a \fBpipe\fR(2) and send +the standard output of the last dcmd in the \fBmdb\fR pipeline to an external +process created by executing \fB$SHELL\fR \fB-c\fR followed by the string +formed by concatenating the words after the \fB!\fR character. For more +details, refer to \fBShell Escapes\fR below. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIexpression\fR \fI pipeline\fR [\fB!\fR \fIword\fR .\|.\|.] [ \fB;\fR ]\fR +.ad +.sp .6 +.RS 4n +A simple-command or pipeline can be prefixed with an expression. Before +execution of the pipeline, the value of dot (the variable denoted by +``\fB\&.\fR'') is set to the value of the expression. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIexpression\fR\fB ,\fR \fIexpression\fR \fIpipeline \fR [\fB!\fR +\fIword\fR .\|.\|.] [ \fB;\fR ]\fR +.ad +.sp .6 +.RS 4n +A simple-command or pipeline can be prefixed with two expressions. The first is +evaluated to determine the new value of dot, and the second is evaluated to +determine a repeat count for the first dcmd in the pipeline. This dcmd is +executed \fIcount\fR times before the next dcmd in the pipeline is executed. +The repeat count only applies to the first dcmd in the pipeline. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB,\fR \fIexpression\fR \fIpipeline\fR [\fB!\fR \fIword\fR .\|.\|.] [ +\fB;\fR ]\fR +.ad +.sp .6 +.RS 4n +If the initial expression is omitted, dot is not modified but the first dcmd in +the pipeline is repeated according to the value of the expression. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIexpression\fR [\fB!\fR \fIword\fR .\|.\|.] [ \fB;\fR ]\fR +.ad +.sp .6 +.RS 4n +A command can consist only of an arithmetic expression. The expression is +evaluated and the dot variable is set to its value, and then the previous dcmd +and arguments are executed using the new value of dot. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIexpression\fR\fB,\fR \fIexpression\fR [\fB!\fR \fI word\fR .\|.\|.] [ +\fB;\fR ]\fR +.ad +.sp .6 +.RS 4n +A command can consist only of a dot expression and repeat count expression. +After dot is set to the value of the first expression, the previous dcmd and +arguments are repeatedly executed the number of times specified by the value of +the second expression. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB,\fR \fIexpression \fR [\fB!\fR \fIword\fR .\|.\|.] [ \fB;\fR ]\fR +.ad +.sp .6 +.RS 4n +If the initial expression is omitted, dot is not modified but the previous dcmd +and arguments are repeatedly executed the number of times specified by the +value of the count expression. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB!\fR \fIword\fR .\|.\|. [ \fB;\fR ]\fR +.ad +.sp .6 +.RS 4n +If the command begins with the \fB!\fR character, no dcmds are executed and the +debugger simply executes \fB$SHELL\fR \fB-c\fR followed by the string formed by +concatenating the words after the \fB!\fR character. +.RE + +.SS "Comments" +.sp +.LP +A word beginning with \fB//\fR causes that word and all the subsequent +characters up to a \fINEWLINE\fR to be ignored. +.SS "Arithmetic Expansion" +.sp +.LP +Arithmetic expansion is performed when an \fBmdb\fR command is preceded by an +optional expression representing a start address, or a start address and a +repeat count. Arithmetic expansion can also be performed to compute a numerical +argument for a dcmd. An arithmetic expression can appear in an argument list +enclosed in square brackets preceded by a dollar sign (\fB$[ expression ]\fR), +and is replaced by the value of the expression. +.sp +.LP +Expressions can contain any of the following special words: +.sp +.ne 2 +.mk +.na +\fB\fIinteger\fR\fR +.ad +.RS 22n +.rt +The specified integer value. Integer values can be prefixed with \fB0i\fR or +\fB0I\fR to indicate binary values, \fB0o\fR or \fB0O\fR to indicate octal +values, \fB0t\fR or \fB0T\fR to indicate decimal values, and \fB0x\fR or +\fB0X\fR to indicate hexadecimal values (the default). +.RE + +.sp +.ne 2 +.mk +.na +\fB0[tT][0-9]+.[0-9]+\fR +.ad +.RS 22n +.rt +The specified decimal floating point value, converted to its \fBIEEE\fR +double-precision floating point representation. +.RE + +.sp +.ne 2 +.mk +.na +\fB\&'\fIcccccccc\fR'\fR +.ad +.RS 22n +.rt +The integer value computed by converting each character to a byte equal to its +\fBASCII\fR value. Up to eight characters can be specified in a character +constant. Characters are packed into the integer in reverse order +(right-to-left) beginning at the least significant byte. +.RE + +.sp +.ne 2 +.mk +.na +\fB<\fIidentifier\fR\fR +.ad +.RS 22n +.rt +The value of the variable named by \fIidentifier\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIidentifier\fR\fR +.ad +.RS 22n +.rt +The value of the symbol named by \fIidentifier\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB(\fIexpression\fR)\fR +.ad +.RS 22n +.rt +The value of \fIexpression\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\&.\fR +.ad +.RS 22n +.rt +The value of dot. +.RE + +.sp +.ne 2 +.mk +.na +\fB&\fR +.ad +.RS 22n +.rt +The most recent value of dot used to execute a dcmd. +.RE + +.sp +.ne 2 +.mk +.na +\fB+\fR +.ad +.RS 22n +.rt +The value of dot incremented by the current increment. +.RE + +.sp +.ne 2 +.mk +.na +\fB^\fR +.ad +.RS 22n +.rt +The value of dot decremented by the current increment. +.RE + +.sp +.LP +The increment is a global variable that stores the total bytes read by the last +formatting dcmd. For more information on the increment, refer to the discussion +of \fBFormatting dcmds\fR below. +.sp +.LP +Unary operators are right associative and have higher precedence than binary +operators. The unary operators are: +.sp +.ne 2 +.mk +.na +\fB#\fIexpression\fR\fR +.ad +.RS 23n +.rt +Logical negation. +.RE + +.sp +.ne 2 +.mk +.na +\fB~\fIexpression\fR\fR +.ad +.RS 23n +.rt +Bitwise complement. +.RE + +.sp +.ne 2 +.mk +.na +\fB-\fIexpression\fR\fR +.ad +.RS 23n +.rt +Integer negation. +.RE + +.sp +.ne 2 +.mk +.na +\fB%\fIexpression\fR\fR +.ad +.RS 23n +.rt +The value of a pointer-sized quantity at the object file location corresponding +to virtual address \fIexpression\fR in the target's virtual address space. +.RE + +.sp +.ne 2 +.mk +.na +\fB%/[csil]/\fIexpression\fR\fR +.ad +.RS 23n +.rt +The value of a char, short, int, or long-sized quantity at the object file +location corresponding to virtual address \fIexpression\fR in the target's +virtual address space. +.RE + +.sp +.ne 2 +.mk +.na +\fB%/[1248]/\fIexpression\fR\fR +.ad +.RS 23n +.rt +The value of a one, two, four, or eight-byte quantity at the object file +location corresponding to virtual address \fIexpression\fR in the target's +virtual address space. +.RE + +.sp +.ne 2 +.mk +.na +\fB*\fIexpression\fR\fR +.ad +.RS 23n +.rt +The value of a pointer-sized quantity at virtual address \fIexpression\fR in +the target's virtual address space. +.RE + +.sp +.ne 2 +.mk +.na +\fB*/[csil]/\fIexpression\fR\fR +.ad +.RS 23n +.rt +The value of a char, short, int, or long-sized quantity at virtual address +\fIexpression\fR in the target's virtual address space. +.RE + +.sp +.ne 2 +.mk +.na +\fB*/[1248]/\fIexpression\fR\fR +.ad +.RS 23n +.rt +The value of a one, two, four, or eight-byte quantity at virtual address +\fIexpression\fR in the target's virtual address space. +.RE + +.sp +.LP +Binary operators are left associative and have lower precedence than unary +operators. The binary operators, in order of precedence from highest to lowest, +are: +.sp +.ne 2 +.mk +.na +\fB\fB*\fR\fR +.ad +.RS 6n +.rt +Integer multiplication. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB%\fR\fR +.ad +.RS 6n +.rt +Integer division. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB#\fR\fR +.ad +.RS 6n +.rt +Left-hand side rounded up to next multiple of right-hand side. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB+\fR\fR +.ad +.RS 6n +.rt +Integer addition. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-\fR\fR +.ad +.RS 6n +.rt +Integer subtraction. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB<<\fR\fR +.ad +.RS 6n +.rt +Bitwise shift left. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB>>\fR\fR +.ad +.RS 6n +.rt +Bitwise shift right. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB==\fR\fR +.ad +.RS 6n +.rt +Logical equality. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB!=\fR\fR +.ad +.RS 6n +.rt +Logical inequality. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB&\fR\fR +.ad +.RS 6n +.rt +Bitwise AND. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB\fR^\fR +.ad +.RS 6n +.rt +Bitwise exclusive OR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB|\fR\fR +.ad +.RS 6n +.rt +Bitwise inclusive OR. +.RE + +.SS "Quoting" +.sp +.LP +Each metacharacter described above (see \fBSyntax\fR) terminates a word unless +quoted. Characters can be quoted (forcing \fBmdb\fR to interpret each character +as itself without any special significance) by enclosing them in a pair of +single (\fB\&' '\fR) or double (\fB" "\fR) quote marks. A single quote cannot +appear within single quotes. Inside double quotes, \fBmdb\fR recognizes the C +programming language character escape sequences. +.SS "Shell Escapes" +.sp +.LP +The \fB!\fR character can be used to create a pipeline between an \fBmdb\fR +command and the user's shell. If the $\fBSHELL\fR environment variable is set, +\fBmdb\fR forks and execs this program for shell escapes; otherwise +\fB/bin/sh\fR is used. The shell is invoked with the \fB-c\fR option followed +by a string formed by concatenating the words after the \fB!\fR character. The +\fB!\fR character takes precedence over all other metacharacters, except +semicolon (\fB;\fR) and \fINEWLINE\fR. Once a shell escape is detected, the +remaining characters up to the next semicolon or \fINEWLINE\fR are passed as is +to the shell. The output of shell commands can not be piped to \fBmdb\fR dcmds. +Commands executed by a shell escape have their output sent directly to the +terminal, not to \fBmdb\fR. +.SS "Variables" +.sp +.LP +A \fIvariable\fR is a variable name, a corresponding integer value, and a set +of attributes. A variable name is a sequence of letters, digits, underscores, +or periods. A variable can be assigned a value using the \fB>\fR dcmd or +\fB::typeset\fR dcmd, and its attributes can be manipulated using the +\fB::typeset\fR dcmd. Each variable's value is represented as a 64-bit unsigned +integer. A variable can have one or more of the following attributes: read-only +(cannot be modified by the user), persistent (cannot be unset by the user), and +tagged (user-defined indicator). +.sp +.LP +The following variables are defined as persistent: +.sp +.ne 2 +.mk +.na +\fB0\fR +.ad +.RS 10n +.rt +The most recent value printed using the \fB/\fR, \fB\e\fR, \fB?\fR, or \fB=\fR +dcmd. +.RE + +.sp +.ne 2 +.mk +.na +\fB9\fR +.ad +.RS 10n +.rt +The most recent count used with the \fB$<\fR dcmd. +.RE + +.sp +.ne 2 +.mk +.na +\fBb\fR +.ad +.RS 10n +.rt +The virtual address of the base of the data section. +.RE + +.sp +.ne 2 +.mk +.na +\fBd\fR +.ad +.RS 10n +.rt +The size of the data section in bytes. +.RE + +.sp +.ne 2 +.mk +.na +\fBe\fR +.ad +.RS 10n +.rt +The virtual address of the entry point. +.RE + +.sp +.ne 2 +.mk +.na +\fBm\fR +.ad +.RS 10n +.rt +The initial bytes (magic number) of the target's primary object file, or zero +if no object file has been read yet. +.RE + +.sp +.ne 2 +.mk +.na +\fBt\fR +.ad +.RS 10n +.rt +The size of the text section in bytes. +.RE + +.sp +.ne 2 +.mk +.na +\fBhits\fR +.ad +.RS 10n +.rt +The count of the number of times the matched software event specifier has been +matched. See \fBEvent Callbacks\fR, below. +.RE + +.sp +.ne 2 +.mk +.na +\fBthread\fR +.ad +.RS 10n +.rt +The thread identifier of the current representative thread. The value of the +identifier depends on the threading model used by the current target. See +\fBThread Support\fR, below. +.RE + +.sp +.LP +In addition, the \fBmdb\fR kernel and process targets export the current values +of the representative thread's register set as named variables. The names of +these variables depend on the target's platform and instruction set +architecture. +.SS "Symbol Name Resolution" +.sp +.LP +As explained in the \fBSyntax\fR description above, a symbol identifier present +in an expression context evaluates to the value of this symbol. The value +typically denotes the virtual address of the storage associated with the symbol +in the target's virtual address space. A target can support multiple symbol +tables including, but not limited to, a primary executable symbol table, a +primary dynamic symbol table, a run-time link-editor symbol table, and standard +and dynamic symbol tables for each of a number of load objects (such as shared +libraries in a user process, or kernel modules in the Solaris kernel). The +target typically searches the primary executable's symbol tables first, and +then one or more of the other symbol tables. Notice that \fBELF\fR symbol +tables only contain entries for external, global, and static symbols; automatic +symbols do not appear in the symbol tables processed by \fBmdb\fR. +.sp +.LP +Additionally, \fBmdb\fR provides a private user-defined symbol table that is +searched prior to any of the target symbol tables. The private symbol table is +initially empty, and can be manipulated using the \fB::nmadd\fR and +\fB::nmdel\fR dcmds. The \fB::nm\fR \fB-P\fR option can be used to display the +contents of the private symbol table. The private symbol table allows the user +to create symbol definitions for program functions or data that were either +missing from the original program or stripped out. These definitions are then +used whenever \fBmdb\fR converts a symbolic name to an address, or an address +to the nearest symbol. +.sp +.LP +As targets contain multiple symbol tables, and each symbol table can include +symbols from multiple object files, different symbols with the same name can +exist. \fBmdb\fR uses the backquote (\fB`\fR) character as a symbol name +scoping operator to allow the programmer to obtain the value of the desired +symbol in this situation. The programmer can specify the scope used to resolve +a symbol name as either: \fIobject\fR\fB`\fR\fIname\fR, or +\fIfile\fR\fB`\fR\fIname\fR, or \fIobject\fR\fB`\fR\fIfile\fR\fB`\fR\fIname\fR. +The object identifier refers to the name of a load object. The file identifier +refers to the basename of a source file that has a symbol of type +\fBSTT_FILE\fR in the specified object's symbol table. The object identifier's +interpretation depends on the target type. +.sp +.LP +The \fBmdb\fR kernel target expects \fIobject\fR to specify the basename of a +loaded kernel module. For example, the symbol name +.sp +.in +2 +.nf +specfs`_init +.fi +.in -2 +.sp + +.sp +.LP +evaluates to the value of the \fB_init\fR symbol in the \fBspecfs\fR kernel +module. +.sp +.LP +The \fBmdb\fR process target expects \fIobject\fR to specify the name of the +executable or of a loaded shared library. It can take any of the following +forms: +.RS +4 +.TP +1. +An exact match (that is, a full pathname): \fB/usr/lib/libc.so.1\fR +.RE +.RS +4 +.TP +2. +An exact basename match: \fBlibc.so.1\fR +.RE +.RS +4 +.TP +3. +An initial basename match up to a ``\fB\&.\fR'' suffix: \fBlibc.so\fR or +\fBlibc\fR +.RE +.RS +4 +.TP +4. +The literal string \fBa.out\fR is accepted as an alias for the executable. +.RE +.sp +.LP +The process target also accepts any of the four forms described above preceded +by an optional link-map id (lmid). The lmid prefix is specified by an initial +"\fBLM\fR" followed by the link-map id in hexadecimal followed by an additional +backquote. For example, the symbol name +.sp +.in +2 +.nf +LM0`libc.so.1`_init +.fi +.in -2 +.sp + +.sp +.LP +evaluates to the value of the \fB_init\fR symbol in the \fBlibc.so.1\fR library +that is loaded on link-map 0 (\fBLM_ID_BASE\fR). The link-map specifier can be +necessary to resolve symbol naming conflicts in the event that the same library +is loaded on more than one link map. For more information on link maps, refer +to the \fILinker and Libraries Guide\fR and \fBdlopen\fR(3C). Link-map +identifiers are displayed when symbols are printed according to the setting of +the \fBshowlmid\fR option, as described under OPTIONS. +.sp +.LP +In the case of a naming conflict between symbols and hexadecimal integer +values, \fBmdb\fR attempts to evaluate an ambiguous token as a symbol first, +before evaluating it as an integer value. For example, the token \fBf\fR can +either refer to the decimal integer value \fB15\fR specified in hexadecimal +(the default base), or to a global variable named \fBf\fR in the target's +symbol table. If a symbol with an ambiguous name is present, the integer value +can be specified by using an explicit \fB0x\fR or \fB0X\fR prefix. +.SS "dcmd and Walker Name Resolution" +.sp +.LP +As described earlier, each \fBmdb\fR dmod provides a set of dcmds and walkers. +dcmds and walkers are tracked in two distinct, global namespaces. \fBmdb\fR +also keeps track of a dcmd and walker namespace associated with each dmod. +Identically named dcmds or walkers within a given dmod are not allowed: a dmod +with this type of naming conflict fails to load. Name conflicts between dcmds +or walkers from different dmods are allowed in the global namespace. In the +case of a conflict, the first dcmd or walker with that particular name to be +loaded is given precedence in the global namespace. Alternate definitions are +kept in a list in load order. The backquote character (\fB`\fR) can be used in +a dcmd or walker name as a scoping operator to select an alternate definition. +For example, if dmods \fBm1\fR and \fBm2\fR each provide a dcmd \fBd\fR, and +\fBm1\fR is loaded prior to \fBm2\fR, then: +.sp +.ne 2 +.mk +.na +\fB\fB::d\fR\fR +.ad +.RS 10n +.rt +Executes \fBm1\fR's definition of \fBd\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::m1`d\fR\fR +.ad +.RS 10n +.rt +Executes \fBm1\fR's definition of \fBd\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::m2`d\fR\fR +.ad +.RS 10n +.rt +Executes \fBm2'\fRs definition of \fBd\fR. +.RE + +.sp +.LP +If module \fBm1\fR were now unloaded, the next dcmd on the global definition +list (\fBm2`d\fR) would be promoted to global visibility. The current +definition of a dcmd or walker can be determined using the \fB::which\fR dcmd, +described below. The global definition list can be displayed using the +\fB::which\fR \fB-v\fR option. +.SS "dcmd Pipelines" +.sp +.LP +dcmds can be composed into a pipeline using the \fB|\fR operator. The purpose +of a pipeline is to pass a list of values, typically virtual addresses, from +one dcmd or walker to another. Pipeline stages might be used to map a pointer +from one type of data structure to a pointer to a corresponding data structure, +to sort a list of addresses, or to select the addresses of structures with +certain properties. +.sp +.LP +\fBmdb\fR executes each dcmd in the pipeline in order from left to right. The +leftmost dcmd is executed using the current value of dot, or using the value +specified by an explicit expression at the start of the command. When a \fB|\fR +operator is encountered, \fBmdb\fR creates a pipe (a shared buffer) between the +output of the dcmd to its left and the \fBmdb\fR parser, and an empty list of +values. As the dcmd executes, its standard output is placed in the pipe and +then consumed and evaluated by the parser, as if \fBmdb\fR were reading this +data from standard input. Each line must consist of an arithmetic expression +terminated by a \fINEWLINE\fR or semicolon (\fB;\fR). The value of the +expression is appended to the list of values associated with the pipe. If a +syntax error is detected, the pipeline is aborted. +.sp +.LP +When the dcmd to the left of a \fB|\fR operator completes, the list of values +associated with the pipe is then used to invoke the dcmd to the right of the +\fB|\fR operator. For each value in the list, dot is set to this value and the +right-hand dcmd is executed. Only the rightmost dcmd in the pipeline has its +output printed to standard output. If any dcmd in the pipeline produces output +to standard error, these messages are printed directly to standard error and +are not processed as part of the pipeline. +.SS "Signal Handling" +.sp +.LP +The debugger ignores the \fBPIPE\fR and \fBQUIT\fR signals. The \fBINT\fR +signal aborts the command that is currently executing. The debugger intercepts +and provides special handling for the \fBILL\fR, \fBTRAP\fR, \fBEMT\fR, +\fBFPE\fR, \fBBUS\fR, and \fBSEGV\fR signals. If any of these signals are +generated asynchronously (that is, delivered from another process using +\fBkill\fR(2)), \fBmdb\fR restores the signal to its default disposition and +dump core. However, if any of these signals are generated synchronously by the +debugger process itself and a dcmd from an externally loaded dmod is currently +executing, and standard input is a terminal, \fBmdb\fR provides a menu of +choices allowing the user to force a core dump, quit without producing a core +dump, stop for attach by a debugger, or attempt to resume. The resume option +aborts all active commands and unload the dmod whose dcmd was active at the +time the fault occurred. It can then be subsequently re-loaded by the user. The +resume option provides limited protection against buggy dcmds. Refer to +WARNINGS, \fBUse of the Error Recovery Mechanism\fR, below for information +about the risks associated with the resume option. +.SS "Command Re-entry" +.sp +.LP +The text of the last \fBHISTSIZE \fR (default 128) commands entered from a +terminal device are saved in memory. The in-line editing facility, described +next, provides key mappings for searching and fetching elements from the +history list. +.SS "In-line Editing" +.sp +.LP +If standard input is a terminal device, \fBmdb\fR provides some simple +emacs-style facilities for editing the command line. The \fBsearch\fR, +\fBprevious\fR, and \fBnext\fR commands in edit mode provide access to the +history list. Only strings, not patterns, are matched when searching. In the +table below, the notation for control characters is caret (\fB^\fR) followed by +a character shown in upper case. The notation for escape sequences is \fBM-\fR +followed by a character. For example, \fBM-f\fR (pronounced meta-eff) is +entered by depressing ESC followed by '\fBf\fR', or by depressing Meta followed +by '\fBf\fR' on keyboards that support a \fBMeta\fR key. A command line is +committed and executed using \fIRETURN\fR or \fINEWLINE\fR. The edit commands +are: +.sp +.ne 2 +.mk +.na +\fB^F\fR +.ad +.RS 14n +.rt +Move cursor forward (right) one character. +.RE + +.sp +.ne 2 +.mk +.na +\fBM-f\fR +.ad +.RS 14n +.rt +Move cursor forward one word. +.RE + +.sp +.ne 2 +.mk +.na +\fB^B\fR +.ad +.RS 14n +.rt +Move cursor backward (left) one character. +.RE + +.sp +.ne 2 +.mk +.na +\fBM-b\fR +.ad +.RS 14n +.rt +Move cursor backward one word. +.RE + +.sp +.ne 2 +.mk +.na +\fB^A\fR +.ad +.RS 14n +.rt +Move cursor to start of line. +.RE + +.sp +.ne 2 +.mk +.na +\fB^E\fR +.ad +.RS 14n +.rt +Move cursor to end of line. +.RE + +.sp +.ne 2 +.mk +.na +\fB^D\fR +.ad +.RS 14n +.rt +Delete current character, if the current line is not empty. If the current line +is empty, \fB^D\fR denotes \fBEOF\fR and the debugger exits. +.RE + +.sp +.ne 2 +.mk +.na +\fBM-^H\fR +.ad +.RS 14n +.rt +(Meta-backspace) Delete previous word. +.RE + +.sp +.ne 2 +.mk +.na +\fB^K\fR +.ad +.RS 14n +.rt +Delete from the cursor to the end of the line. +.RE + +.sp +.ne 2 +.mk +.na +\fB^L\fR +.ad +.RS 14n +.rt +Clear the screen and reprint the current line. +.RE + +.sp +.ne 2 +.mk +.na +\fB^T\fR +.ad +.RS 14n +.rt +Transpose current character with next character. +.RE + +.sp +.ne 2 +.mk +.na +\fB^N\fR +.ad +.RS 14n +.rt +Fetch the next command from the history. Each time \fB^N\fR is entered, the +next command forward in time is retrieved. +.RE + +.sp +.ne 2 +.mk +.na +\fB^P\fR +.ad +.RS 14n +.rt +Fetch the previous command from the history. Each time \fB^P\fR is entered, the +next command backward in time is retrieved. +.RE + +.sp +.ne 2 +.mk +.na +\fB^R[\fIstring\fR]\fR +.ad +.RS 14n +.rt +Search backward in the history for a previous command line containing +\fIstring\fR. The string should be terminated by a \fIRETURN\fR or +\fINEWLINE\fR. If \fIstring\fR is omitted, the previous history element +containing the most recent string is retrieved. +.RE + +.sp +.LP +The editing mode also interprets the following user-defined sequences as +editing commands. User defined sequences can be read or modified using the +\fBstty\fR(1) command. +.sp +.ne 2 +.mk +.na +\fBerase\fR +.ad +.RS 11n +.rt +User defined erase character (usually \fB^H\fR or \fB^?\fR). Delete previous +character. +.RE + +.sp +.ne 2 +.mk +.na +\fBintr\fR +.ad +.RS 11n +.rt +User defined interrupt character (usually \fB^C\fR). Abort the current command +and print a new prompt. +.RE + +.sp +.ne 2 +.mk +.na +\fBkill\fR +.ad +.RS 11n +.rt +User defined kill character (usually \fB^U\fR). Kill the entire current command +line. +.RE + +.sp +.ne 2 +.mk +.na +\fBquit\fR +.ad +.RS 11n +.rt +User defined quit character (usually \fB^\e\fR). Quit the debugger. +.RE + +.sp +.ne 2 +.mk +.na +\fBsuspend\fR +.ad +.RS 11n +.rt +User defined suspend character (usually \fB^Z\fR). Suspend the debugger. +.RE + +.sp +.ne 2 +.mk +.na +\fBwerase\fR +.ad +.RS 11n +.rt +User defined word erase character (usually \fB^W\fR). Erase the preceding word. +.RE + +.sp +.LP +On keyboards that support an extended keypad with arrow keys, \fBmdb\fR +interprets these keystrokes as editing commands: +.sp +.ne 2 +.mk +.na +\fBup-arrow\fR +.ad +.RS 15n +.rt +Fetch the previous command from the history (same as \fB^P\fR). +.RE + +.sp +.ne 2 +.mk +.na +\fBdown-arrow\fR +.ad +.RS 15n +.rt +Fetch the next command from the history (same as \fB^N\fR). +.RE + +.sp +.ne 2 +.mk +.na +\fBleft-arrow\fR +.ad +.RS 15n +.rt +Move cursor backward one character (same as \fB^B\fR). +.RE + +.sp +.ne 2 +.mk +.na +\fBright-arrow\fR +.ad +.RS 15n +.rt +Move cursor forward one character (same as \fB^F\fR). +.RE + +.SS "Output Pager" +.sp +.LP +\fBmdb\fR provides a built-in output pager. The output pager is enabled if the +debugger's standard output is a terminal device. Each time a command is +executed, \fBmdb\fR pauses after one screenful of output is produced and +displays a pager prompt: +.sp +.in +2 +.nf + >> More [<space>, <cr>, q, n, c, a] ? +.fi +.in -2 +.sp + +.sp +.LP +The following key sequences are recognized by the pager: +.sp +.ne 2 +.mk +.na +\fB\fISPACE\fR\fR +.ad +.RS 25n +.rt +Display the next screenful of output. +.RE + +.sp +.ne 2 +.mk +.na +\fBa, A\fR +.ad +.RS 25n +.rt +Abort the current top-level command and return to the prompt. +.RE + +.sp +.ne 2 +.mk +.na +\fBc, C\fR +.ad +.RS 25n +.rt +Continue displaying output without pausing at each screenful until the current +top-level command is complete. +.RE + +.sp +.ne 2 +.mk +.na +\fBn, N, \fINEWLINE\fR, \fIRETURN\fR\fR +.ad +.RS 25n +.rt +Display the next line of output. +.RE + +.sp +.ne 2 +.mk +.na +\fBq, Q, ^C, ^\e\fR +.ad +.RS 25n +.rt +Quit (abort) the current dcmd only. +.RE + +.SS "Formatting dcmds" +.sp +.LP +The \fB/\fR, \fB\e\fR, \fB?\fR, and \fB=\fR metacharacters are used to denote +the special output formatting dcmds. Each of these dcmds accepts an argument +list consisting of one or more format characters, repeat counts, or quoted +strings. A format character is one of the \fBASCII\fR characters shown in the +table below. Format characters are used to read and format data from the +target. A repeat count is a positive integer preceding the format character +that is always interpreted in base 10 (decimal). A repeat count can also be +specified as an expression enclosed in square brackets preceded by a dollar +sign (\fB$[ ]\fR). A string argument must be enclosed in double-quotes (\fB" +"\fR). No blanks are necessary between format arguments. +.sp +.LP +The formatting dcmds are: +.sp +.ne 2 +.mk +.na +\fB\fB/\fR\fR +.ad +.RS 6n +.rt +Display data from the target's virtual address space starting at the virtual +address specified by dot. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB\e\fR\fR +.ad +.RS 6n +.rt +Display data from the target's physical address space starting at the physical +address specified by dot. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB?\fR\fR +.ad +.RS 6n +.rt +Display data from the target's primary object file starting at the object file +location corresponding to the virtual address specified by dot. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB=\fR\fR +.ad +.RS 6n +.rt +Display the value of dot itself in each of the specified data formats. The +\fB=\fR dcmd is therefore useful for converting between bases and performing +arithmetic. +.RE + +.sp +.LP +In addition to dot, \fBmdb\fR keeps track of another global value called the +\fIincrement\fR. The increment represents the distance between dot and the +address following all the data read by the last formatting dcmd. For example, +if a formatting dcmd is executed with dot equal to address A, and displays a +4-byte integer, then after this dcmd completes, dot is still A, but the +increment is set to \fB4\fR. The \fB+\fR character (described under +\fBArithmetic Expansion\fR above) would now evaluate to the value \fBA + 4\fR, +and could be used to reset dot to the address of the next data object for a +subsequent dcmd. +.sp +.LP +Most format characters increase the value of the increment by the number of +bytes corresponding to the size of the data format, shown in the table. The +table of format characters can be displayed from within \fBmdb\fR using the +\fB::formats\fR dcmd. The format characters are: +.sp + +.sp +.TS +tab(); +lw(.69i) lw(4.81i) +lw(.69i) lw(4.81i) +. +\fB+\fRT{ +increment dot by the count (variable size) +T} +\fB-\fRT{ +decrement dot by the count (variable size) +T} +Bhexadecimal int (1 byte) +CT{ +character using C character notation (1 byte) +T} +Ddecimal signed int (4 bytes) +Edecimal unsigned long long (8 bytes) +Fdouble (8 bytes) +Goctal unsigned long long (8 bytes) +Hswap bytes and shorts (4 bytes) +IT{ +address and disassembled instruction (variable size) +T} +Jhexadecimal long long (8 bytes) +Khexadecimal uintptr_t (4 or 8 bytes) +Nnewline +Ooctal unsigned int (4 bytes) +Psymbol (4 or 8 bytes) +Qoctal signed int (4 bytes) +Rbinary int (8 bytes) +ST{ +string using C string notation (variable size) +T} +Thorizontal tab +Udecimal unsigned int (4 bytes) +Vdecimal unsigned int (1 byte) +Wdefault radix unsigned int (4 bytes) +Xhexadecimal int (4 bytes) +Ydecoded time32_t (4 bytes) +Zhexadecimal long long (8 bytes) +^T{ +decrement dot by increment * count (variable size) +T} +adot as symbol+offset +boctal unsigned int (1 byte) +ccharacter (1 byte) +ddecimal signed short (2 bytes) +edecimal signed long long (8 bytes) +ffloat (4 bytes) +goctal signed long long (8 bytes) +hswap bytes (2 bytes) +idisassembled instruction (variable size) +nnewline +ooctal unsigned short (2 bytes) +psymbol (4 or 8 bytes) +qoctal signed short (2 bytes) +rwhitespace +sraw string (variable size) +thorizontal tab +udecimal unsigned short (2 bytes) +vdecimal signed int (1 byte) +wdefault radix unsigned short (2 bytes) +xhexadecimal short (2 bytes) +ydecoded time64_t (8 bytes) +.TE + +.sp +.LP +The \fB/\fR, \fB\e\fR, and \fB?\fR formatting dcmds can also be used to write +to the target's virtual address space, physical address space, or object file +by specifying one of the following modifiers as the first format character, and +then specifying a list of words that are either immediate values or expressions +enclosed in square brackets preceded by a dollar sign (\fB$[ ]\fR). +.sp +.LP +The write modifiers are: +.sp +.ne 2 +.mk +.na +\fB\fBv\fR\fR +.ad +.RS 5n +.rt +Write the lowest byte of the value of each expression to the target beginning +at the location specified by dot. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBw\fR\fR +.ad +.RS 5n +.rt +Write the lowest two bytes of the value of each expression to the target +beginning at the location specified by dot. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBW\fR\fR +.ad +.RS 5n +.rt +Write the lowest 4 bytes of the value of each expression to the target +beginning at the location specified by dot. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBZ\fR\fR +.ad +.RS 5n +.rt +Write the complete 8 bytes of the value of each expression to the target +beginning at the location specified by dot. +.RE + +.sp +.LP +The \fB/\fR, \fB\e\fR, and \fB?\fR formatting dcmds can also be used to search +for a particular integer value in the target's virtual address space, physical +address space, and object file, respectively, by specifying one of the +following modifiers as the first format character, and then specifying a value +and optional mask. The value and mask are each specified as either immediate +values or expressions enclosed in square brackets preceded by a dollar sign. If +only a value is specified, \fBmdb\fR reads integers of the appropriate size and +stops at the address containing the matching value. If a value \fBV\fR and mask +\fBM\fR are specified, \fBmdb\fR reads integers of the appropriate size and +stops at the address containing a value \fBX\fR where \fB(X & M) == V\fR. At +the completion of the dcmd, dot is updated to the address containing the match. +If no match is found, dot is left at the last address that was read. +.sp +.LP +The search modifiers are: +.sp + +.sp +.TS +tab(); +lw(.69i) lw(4.81i) +lw(.69i) lw(4.81i) +. +lSearch for the specified 2-byte value. +LSearch for the specified 4-byte value. +MSearch for the specified 8-byte value. +.TE + +.sp +.LP +Notice that for both user and kernel targets, an address space is typically +composed of a set of discontiguous segments. It is not legal to read from an +address that does not have a corresponding segment. If a search reaches a +segment boundary without finding a match, it aborts when the read past the end +of the segment boundary fails. +.SS "Execution Control" +.sp +.LP +\fBmdb\fR provides facilities for controlling and tracing the execution of a +live running program. Currently, only the user process target provides support +for execution control. \fBmdb\fR provides a simple model of execution control: +a target process can be started from within the debugger using \fB::run\fR, or +\fBmdb\fR can attach to an existing process using \fB:A\fR, \fB::attach\fR, or +the \fB-p\fR command-line option, as described below. A list of traced software +events can be specified by the user. Each time a traced event occurs in the +target process, all threads in the target stop, the thread that triggered the +event is chosen as the representative thread, and control returns to the +debugger. Once the target program is set running, control can be asynchronously +returned to the debugger by typing the user-defined interrupt character +(typically \fB^C\fR). +.sp +.LP +A \fBsoftware event\fR is a state transition in the target program that is +observed by the debugger. For example, the debugger can observe the transition +of a program counter register to a value of interest (a breakpoint) or the +delivery of a particular signal. +.sp +.LP +A \fBsoftware event specifier\fR is a description of a class of software events +that is used by the debugger to instrument the target program in order to +observe these events. The \fB::events\fR dcmd is used to list the software +event specifiers. A set of standard properties is associated with each event +specifier, as described under \fB::events\fR, below. +.sp +.LP +The debugger can observe a variety of different software events, including +breakpoints, watchpoints, signals, machine faults, and system calls. New +specifiers can be created using \fB::bp\fR, \fB::fltbp\fR, \fB::sigbp\fR, +\fB::sysbp\fR, or \fB::wp\fR. Each specifier has an associated callback (an +\fBmdb\fR command string to execute as if it had been typed at the command +prompt) and a set of properties, as described below. Any number of specifiers +for the same event can be created, each with different callbacks and +properties. The current list of traced events and the properties of the +corresponding event specifiers can be displayed using the \fB::events\fR dcmd. +The event specifier properties are defined as part of the description of the +\fB::events\fR and \fB::evset\fR dcmds, below. +.sp +.LP +The execution control built-in dcmds, described below, are always available, +but issues an error message indicating they are not supported if applied to a +target that does not support execution control. For more information about the +interaction of exec, attach, release, and job control with debugger execution +control, refer to NOTES, below. +.SS "Event Callbacks" +.sp +.LP +The \fB::evset\fR dcmd and event tracing dcmds allow you to associate an event +callback (using the \fB-c\fR option) with each event specifier. The event +callbacks are strings that represent \fBmdb\fR commands to execute when the +corresponding event occurs in the target. These commands are executed as if +they had been typed at the command prompt. Before executing each callback, the +dot variable is set to the value of the representative thread's program counter +and the "\fBhits\fR" variable is set to the number of times this specifier has +been matched, including the current match. +.sp +.LP +If the event callbacks themselves contain one or more commands to continue the +target (for example, \fB::cont\fR or \fB::step\fR), these commands do not +immediately continue the target and wait for it to stop again. Instead, inside +of an event callback, the continue dcmds note that a continue operation is now +pending, and then return immediately. Therefore, if multiple dcmds are included +in an event callback, the step or continue dcmd should be the last command +specified. Following the execution of \fBall\fR event callbacks, the target +immediately resumes execution if \fBall\fR matching event callbacks requested a +continue. If conflicting continue operations are requested, the operation with +the highest precedence determines what type of continue occurs. The order of +precedence from highest to lowest is: step, step-over (next), step-out, +continue. +.SS "Thread Support" +.sp +.LP +\fBmdb\fR provides facilities to examine the stacks and registers of each +thread associated with the target. The persistent "\fBthread\fR" variable +contains the current representative thread identifier. The format of the thread +identifier depends on the target. The \fB::regs\fR and \fB::fpregs\fR dcmds can +be used to examine the register set of the representative thread, or of another +thread if its register set is currently available. In addition, the register +set of the representative thread is exported as a set of named variables. The +user can modify the value of one or more registers by applying the \fB>\fR dcmd +to the corresponding named variable. +.sp +.LP +The \fBmdb\fR kernel target exports the virtual address of the corresponding +internal thread structure as the identifier for a given thread. The \fISolaris +Modular Debugger Guide\fR provides more information on debugging support for +threads in the Solaris kernel. The \fBmdb\fR process target provides proper +support for examination of multi-threaded user processes that use the native +\fBlwp_*\fR interfaces, \fB/usr/lib/libthread.so\fR or +\fB/usr/lib/lwp/libthread.so\fR. When debugging a live user process, \fBmdb\fR +detects if a single threaded process \fBdlopen\fRs or closes \fBlibthread\fR +and automatically adjusts its view of the threading model on-the-fly. The +process target thread identifiers corresponds to either the \fBlwpid_t\fR, +\fBthread_t\fR, or \fBpthread_t\fR of the representative, depending on the +threading model used by the application. +.sp +.LP +If \fBmdb\fR is debugging a user process target and the target makes use of +compiler-supported thread-local storage, \fBmdb\fR automatically evaluates +symbol names referring to thread-local storage to the address of the storage +corresponding to the current representative thread. The \fB::tls\fR built-in +dcmd can be used to display the value of the symbol for threads other than the +representative thread. +.SS "Built-in dcmds" +.sp +.LP +\fBmdb\fR provides a set of built-in dcmds that are always defined. Some of +these dcmds are only applicable to certain targets: if a dcmd is not applicable +to the current target, it fails and prints a message indicating "command is not +supported by current target". In many cases, \fBmdb\fR provides a mnemonic +equivalent (\fB::identifier\fR) for the legacy \fBadb\fR(1) dcmd names. For +example, \fB::quit\fR is provided as the equivalent of \fB$q\fR. Programmers +who are experienced with \fBadb\fR(1) or who appreciate brevity or arcana can +prefer the \fB$\fR or \fB:\fR forms of the built-ins. Programmers who are new +to \fBmdb\fR might prefer the more verbose \fB::\fR form. The built-ins are +shown in alphabetical order. If a \fB$\fR or \fB:\fR form has a +\fB::identifier\fR equivalent, it is shown underneath the \fB::identifier\fR +form. The built-in dcmds are: +.sp +.ne 2 +.mk +.na +\fB> \fIvariable-name\fR\fR +.ad +.br +.na +\fB\fB>\fR/\fImodifier\fR/\fIvariable-name\fR\fR +.ad +.sp .6 +.RS 4n +Assign the value of dot to the specified named variable. Some variables are +read-only and can not be modified. If the \fB>\fR is followed by a modifier +character surrounded by \fB/ /\fR, then the value is modified as part of the +assignment. The modifier characters are: +.sp +.ne 2 +.mk +.na +\fB\fBc\fR\fR +.ad +.RS 5n +.rt +unsigned char quantity (1-byte) +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBs\fR\fR +.ad +.RS 5n +.rt +unsigned short quantity (2-byte) +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBi\fR\fR +.ad +.RS 5n +.rt +unsigned int quantity (4-byte) +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBl\fR\fR +.ad +.RS 5n +.rt +unsigned long quantity (4-byte in 32-bit, 8-byte in 64-bit) +.RE + +Notice that these operators do not perform a cast. Instead, they fetch the +specified number of low-order bytes (on little-endian architectures) or +high-order bytes (big-endian architectures). Modifiers are provided for +backwards compatibility; the \fBmdb\fR */\fImodifier\fR/ and %/\fImodifier\fR/ +syntax should be used instead. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB$<\fR \fImacro-name\fR\fR +.ad +.sp .6 +.RS 4n +Read and execute commands from the specified macro file. The filename can be +given as an absolute or relative path. If the filename is a simple name (that +is, if it does not contain a '\fB/\fR'), \fBmdb\fR searches for it in the macro +file include path. If another macro file is currently being processed, this +file is closed and replaced with the new file. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB$<<\fR \fImacro-name\fR\fR +.ad +.sp .6 +.RS 4n +Read and execute commands from the specified macro file (as with \fB$<\fR), but +do not close the current open macro file. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB$?\fR\fR +.ad +.sp .6 +.RS 4n +Print the process-\fBID\fR and current signal of the target if it is a user +process or core file, and then print the general register set of the +representative thread. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIaddress\fR ] \fB$C\fR [ \fIcount\fR ]\fR +.ad +.sp .6 +.RS 4n +Print a C stack backtrace, including stack frame pointer information. If the +dcmd is preceded by an explicit \fIaddress\fR, a backtrace beginning at this +virtual memory address is displayed. Otherwise the stack of the representative +thread is displayed. If an optional count value is given as an argument, no +more than \fIcount\fR arguments are displayed for each stack frame in the +output. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIbase\fR ] \fB$d\fR\fR +.ad +.sp .6 +.RS 4n +Get or set the default output radix. If the dcmd is preceded by an explicit +expression, the default output radix is set to the given \fIbase\fR; otherwise +the current radix is printed in base 10 (decimal). The default radix is base 16 +(hexadecimal). +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB$e\fR\fR +.ad +.sp .6 +.RS 4n +Print a list of all known external (global) symbols of type object or function, +the value of the symbol, and the first 4 (32-bit \fBmdb\fR) or 8 (64-bit +\fBmdb\fR) bytes stored at this location in the target's virtual address space. +The \fB::nm\fR dcmd provides more flexible options for displaying symbol +tables. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB$P\fR \fIprompt-string\fR\fR +.ad +.sp .6 +.RS 4n +Set the prompt to the specified \fIprompt-string\fR. The default prompt +is '\fB>\fR '. The prompt can also be set using \fB::set\fR \fB-P\fR or the +\fB-P\fR command-line option. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIdistance\fR \fB$s\fR\fR +.ad +.sp .6 +.RS 4n +Get or set the symbol matching \fIdistance\fR for address-to-symbol-name +conversions. The symbol matching distance modes are discussed along with the +\fB-s\fR command-line option under OPTIONS. The symbol matching distance can +also be modified using the \fB::set\fR \fB-s\fR option. If no distance is +specified, the current setting is displayed. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB$v\fR\fR +.ad +.sp .6 +.RS 4n +Print a list of the named variables that have non-zero values. The \fB::vars\fR +dcmd provides other options for listing variables. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIwidth\fR \fB$w\fR\fR +.ad +.sp .6 +.RS 4n +Set the output page \fIwidth\fR to the specified value. Typically, this command +is not necessary as \fBmdb\fR queries the terminal for its width and handles +resize events. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB$W\fR\fR +.ad +.sp .6 +.RS 4n +Re-open the target for writing, as if \fBmdb\fR had been executed with the +\fB-w\fR option on the command line. Write mode can also be enabled with the +\fB::set\fR \fB-w\fR option. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIpid\fR ] \fB::attach \fR [ \fIcore\fR | \fIpid\fR ]\fR +.ad +.br +.na +\fB[ \fIpid\fR ] \fB:A\fR [ \fI core\fR | \fIpid\fR ]\fR +.ad +.sp .6 +.RS 4n +If the user process target is active, attach to and debug the specified +process-\fBID\fR or \fIcore\fR file. The core file pathname should be specified +as a string argument. The process-\fBID\fR can be specified as the string +argument, or as the value of the expression preceding the dcmd. Recall that the +default base is hexadecimal, so decimal \fBPID\fRs obtained using +\fBpgrep\fR(1) or \fBps\fR(1) should be preceded with "\fB0t\fR" when specified +as expressions. +.RE + +.sp +.ne 2 +.mk +.na +\fB[\fIaddress\fR] \fB::bp\fR [\fB-/\fR\fB-dDesT\fR] [\fB-c\fR \fIcmd\fR] +[\fB-n\fR \fIcount\fR] \fIsym\fR ...\fR +.ad +.br +.na +\fB\fIaddress\fR \fB:b\fR [\fIcmd\fR ...]\fR +.ad +.sp .6 +.RS 4n +Set a breakpoint at the specified locations. The \fB::bp\fR dcmd sets a +breakpoint at each address or symbol specified, including an optional address +specified by an explicit expression preceding the dcmd, and each string or +immediate value following the dcmd. The arguments can either be symbol names or +immediate values denoting a particular virtual address of interest. If a symbol +name is specified, it can refer to a symbol that cannot yet be evaluated in the +target process. That is, it can consist of an object name and function name in +a load object that has not yet been opened. In this case, the breakpoint is +deferred and is not active in the target until an object matching the given +name is loaded. The breakpoint is automatically enabled when the load object is +opened. Breakpoints on symbols defined in a shared library should always be set +using a symbol name and not using an address expression, as the address can +refer to the corresponding Procedure Linkage Table (\fBPLT\fR) entry instead of +the actual symbol definition. Breakpoints set on \fBPLT\fR entries can be +overwritten by the run-time link-editor when the \fBPLT\fR entry is +subsequently resolved to the actual symbol definition. The \fB-d\fR, \fB-D\fR, +\fB-e\fR, \fB-s\fR, \fB-t\fR, \fB-T\fR, \fB-c\fR, and \fB-n\fR options have the +same meaning as they do for the \fB::evset\fR dcmd, as described below. If the +\fB:b\fR form of the dcmd is used, a breakpoint is only set at the virtual +address specified by the expression preceding the dcmd. The arguments following +the \fB:b\fR dcmd are concatenated together to form the callback string. If +this string contains meta-characters, it must be quoted. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::cat\fR \fIfilename\fR ...\fR +.ad +.sp .6 +.RS 4n +Concatenate and display files. Each filename can be specified as a relative or +absolute pathname. The file contents are printed to standard output, but are +not passed to the output pager. This dcmd is intended to be used with the +\fB|\fR operator; the programmer can initiate a pipeline using a list of +addresses stored in an external file. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::cont\fR [ \fISIG\fR ]\fR +.ad +.br +.na +\fB\fB:c\fR [ \fISIG\fR ]\fR +.ad +.sp .6 +.RS 4n +Suspend the debugger, continue the target program, and wait for it to terminate +or stop following a software event of interest. If the target is already +running because the debugger was attached to a running program with the +\fB-o\fR \fBnostop\fR option enabled, this dcmd simply waits for the target to +terminate or stop after an event of interest. If an optional signal name or +number (see \fBsignal.h\fR(3HEAD)) is specified as an argument, the signal is +immediately delivered to the target as part of resuming its execution. If the +\fBSIGINT\fR signal is traced, control can be asynchronously returned to the +debugger by typing the user-defined interrupt character (usually \fB^C\fR). +This \fBSIGINT\fR signal is automatically cleared and is not observed by the +target the next time it is continued. If no target program is currently +running, \fB::cont\fR starts a new program running as if by \fB::run\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIaddress\fR \fB::context\fR\fR +.ad +.br +.na +\fB\fIaddress\fR \fB$p\fR\fR +.ad +.sp .6 +.RS 4n +Context switch to the specified process. A context switch operation is only +valid when using the kernel target. The process context is specified using the +\fIaddress\fR of its proc structure in the kernel's virtual address space. The +special context address "\fB0\fR" is used to denote the context of the kernel +itself. \fBmdb\fR can only perform a context switch when examining a crash dump +if the dump contains the physical memory pages of the specified user process +(as opposed to just kernel pages). The kernel crash dump facility can be +configured to dump all pages or the pages of the current user process using +\fBdumpadm\fR(1M). The \fB::status\fR dcmd can be used to display the contents +of the current crash dump. +.sp +When the user requests a context switch from the kernel target, \fBmdb\fR +constructs a new target representing the specified user process. Once the +switch occurs, the new target interposes its dcmds at the global level: thus +the \fB/\fR dcmd now formats and displays data from the virtual address space +of the user process, the \fB::mappings\fR dcmd displays the mappings in the +address space of the user process, and so on. The kernel target can be restored +by executing \fB0::context\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::dcmds\fR\fR +.ad +.sp .6 +.RS 4n +List the available dcmds and print a brief description for each one. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIaddress\fR ] \fB::delete\fR [ \fIid\fR | \fBall\fR ]\fR +.ad +.br +.na +\fB[ \fIaddress\fR ] \fB:d\fR [ \fIid\fR | \fBall\fR ]\fR +.ad +.sp .6 +.RS 4n +Delete the event specifiers with the given id number. The id number argument is +interpreted in decimal by default. If an optional address is specified +preceding the dcmd, all event specifiers that are associated with the given +virtual address are deleted (for example, all breakpoints or watchpoints +affecting that address). If the special argument "\fBall\fR" is given, all +event specifiers are deleted, except those that are marked sticky (\fBT\fR +flag). The \fB::events\fR dcmd displays the current list of event specifiers. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIaddress\fR ] \fB::dis\fR [ \fB-fw\fR ] [ \fB-n\fR \fIcount\fR ] [ +\fIaddress\fR ]\fR +.ad +.sp .6 +.RS 4n +Disassemble starting at or around the \fIaddress\fR specified by the final +argument, or the current value of dot. If the address matches the start of a +known function, the entire function is disassembled. Otherwise, a "window" of +instructions before and after the specified address is printed in order to +provide context. By default, instructions are read from the target's virtual +address space. If the \fB-f\fR option is present, instructions are read from +the target's object file instead. The \fB-f\fR option is enabled by default if +the debugger is not currently attached to a live process, core file, or crash +dump. The \fB-w\fR option can be used to force "window"-mode, even if the +address is the start of a known function. The size of the window defaults to +ten instructions; the number of instructions can be specified explicitly using +the \fB-n\fR option. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::disasms\fR\fR +.ad +.sp .6 +.RS 4n +List the available disassembler modes. When a target is initialized, \fBmdb\fR +attempts to select the appropriate disassembler mode. The user can change the +mode to any of the modes listed using the \fB::dismode\fR dcmd. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::dismode\fR [ \fImode\fR ]\fR +.ad +.br +.na +\fB\fB$V\fR [ \fImode\fR ] \fR +.ad +.sp .6 +.RS 4n +Get or set the disassembler mode. If no argument is specified, print the +current disassembler mode. If a \fImode\fR argument is specified, switch the +disassembler to the specified mode. The list of available disassemblers can be +displayed using the \fB::disasms\fR dcmd. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::dmods\fR [ \fB-l\fR ] [ \fImodule-name\fR ]\fR +.ad +.sp .6 +.RS 4n +List the loaded debugger modules. If the \fB-l\fR option is specified, the list +of the dcmds and walkers associated with each dmod is printed below its name. +The output can be restricted to a particular dmod by specifying its name as an +additional argument. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIaddress\fR ] \fB::dump\fR [ \fB-eqrstu\fR ] [ \fB-f\fR|\fB-p\fR ]\fR +.ad +.br +.na +\fB#sp;#sp;[ \fB-g\fR \fIbytes\fR ] [ \fB-w\fR \fIparagraphs\fR ]\fR +.ad +.sp .6 +.RS 4n +Print a hexadecimal and ASCII memory dump of the 16-byte aligned region of +memory containing the address specified by dot. If a repeat count is specified +for \fB::dump\fR, this is interpreted as a number of bytes to dump rather than +a number of iterations. The \fB::dump\fR dcmd also recognizes the following +options: +.sp +.ne 2 +.mk +.na +\fB\fB-e\fR\fR +.ad +.RS 17n +.rt +Adjusts for endian-ness. The \fB-e\fR option assumes 4-byte words. The \fB-g\fR +option can be used to change the default word size. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-f\fR\fR +.ad +.RS 17n +.rt +Reads data from the object file location corresponding to the given virtual +address instead of from the target's virtual address space. The \fB-f\fR option +is enabled by default if the debugger is not currently attached to a live +process, core file, or crash dump. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-g\fR \fIbytes\fR\fR +.ad +.RS 17n +.rt +Displays bytes in groups of \fIbytes\fR. The default group size is 4 bytes. The +group size must be a power of two that divides the line width. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-p\fR\fR +.ad +.RS 17n +.rt +Interprets \fIaddress\fR as a physical address location in the target's address +space instead of a virtual address. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-q\fR\fR +.ad +.RS 17n +.rt +Does not print an ASCII decoding of the data. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-r\fR\fR +.ad +.RS 17n +.rt +Numbers lines relative to the start address instead of with the explicit +address of each line. This option implies the \fB-u\fR option. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-s\fR\fR +.ad +.RS 17n +.rt +Elides repeated lines. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-t\fR\fR +.ad +.RS 17n +.rt +Only reads from and displays the contents of the specified addresses, instead +of reading and printing entire lines. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-u\fR\fR +.ad +.RS 17n +.rt +Unaligns output instead of aligning the output at a paragraph boundary. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-w\fR \fIparagraphs\fR\fR +.ad +.RS 17n +.rt +Displays paragraphs at 16-byte paragraphs per line. The default number of +\fIparagraphs\fR is one. The maximum value accepted for \fB-w\fR is \fB16\fR. +.RE + +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::echo\fR [ \fIstring\fR | \fIvalue\fR ...]\fR +.ad +.sp .6 +.RS 4n +Print the arguments separated by blanks and terminated by a \fINEWLINE\fR to +standard output. Expressions enclosed in \fB$[ ]\fR is evaluated to a value +and printed in the default base. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::eval\fR \fIcommand\fR\fR +.ad +.sp .6 +.RS 4n +Evaluate and execute the specified string as a command. If the command contains +metacharacters or whitespace, it should be enclosed in double or single quotes. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::events\fR [ \fB-av\fR ]\fR +.ad +.br +.na +\fB\fB$b\fR [ \fB-av\fR ]\fR +.ad +.sp .6 +.RS 4n +Display the list of software event specifiers. Each event specifier is assigned +a unique \fBID\fR number that can be used to delete or modify it at a later +time. The debugger can also have its own internal events enabled for tracing. +These events are only be displayed if the \fB-a\fR option is present. If the +\fB-v\fR option is present, a more verbose display, including the reason for +any specifier inactivity, are shown. Here is some sample output: +.sp +.in +2 +.nf +> ::events + ID S TA HT LM Description Action +----- - -- -- -- -------------------------------- ------ +[ 1 ] - T 1 0 stop on SIGINT - +[ 2 ] - T 0 0 stop on SIGQUIT - +[ 3 ] - T 0 0 stop on SIGILL - + ... +[ 11] - T 0 0 stop on SIGXCPU - +[ 12] - T 0 0 stop on SIGXFSZ - +[ 13] - 2 0 stop at libc`printf ::echo printf +> +.fi +.in -2 +.sp + +The following table explains the meaning of each column. A summary of this +information is available using \fB::help\fR \fBevents\fR. +.sp +.ne 2 +.mk +.na +\fB\fBID\fR\fR +.ad +.RS 15n +.rt +The event specifier identifier. The identifier is shown in square brackets \fB[ +]\fR if the specifier is enabled, in parentheses \fB( )\fR if the specifier is +disabled, or in angle brackets \fB< >\fR if the target program is currently +stopped on an event that matches the given specifier. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBS\fR\fR +.ad +.RS 15n +.rt +The event specifier state. The state is one of the following symbols: +.sp +.ne 2 +.mk +.na +\fB\fB-\fR\fR +.ad +.RS 5n +.rt +The event specifier is idle. When no target program is running, all specifiers +are idle. When the target program is running, a specifier can be idle if it +cannot be evaluated (for example, a deferred breakpoint in a shared object that +is not yet loaded). +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB+\fR\fR +.ad +.RS 5n +.rt +The event specifier is active. When the target is continued, events of this +type is detected by the debugger. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB*\fR\fR +.ad +.RS 5n +.rt +The event specifier is armed. This state means that the target is currently +running with instrumentation for this type of event. This state is only visible +if the debugger is attached to a running program with the \fB-o\fR \fBnostop\fR +option. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB!\fR\fR +.ad +.RS 5n +.rt +The event specifier was not armed due to an operating system error. The +\fB::events\fR \fB-v\fR option can be used to display more information about +the reason the instrumentation failed. +.RE + +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBTA\fR\fR +.ad +.RS 15n +.rt +The Temporary, Sticky, and Automatic event specifier properties. One or more of +the following symbols can be shown: +.sp +.ne 2 +.mk +.na +\fB\fBt\fR\fR +.ad +.RS 5n +.rt +The event specifier is temporary, and is deleted the next time the target +stops, regardless of whether it is matched. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBT\fR\fR +.ad +.RS 5n +.rt +The event specifier is sticky, and is not be deleted by \fB::delete\fR +\fBall\fR or \fB:z\fR. The specifier can be deleted by explicitly specifying +its id number to \fB::delete\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBd\fR\fR +.ad +.RS 5n +.rt +The event specifier is automatically disabled when the hit count is equal to +the hit limit. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBD\fR\fR +.ad +.RS 5n +.rt +The event specifier is automatically deleted when the hit count is equal to the +hit limit. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBs\fR\fR +.ad +.RS 5n +.rt +The target automatically stops when the hit count is equal to the hit limit. +.RE + +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBHT\fR\fR +.ad +.RS 15n +.rt +The current hit count. This column displays the number of times the +corresponding software event has occurred in the target since the creation of +this event specifier. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBLM\fR\fR +.ad +.RS 15n +.rt +The current hit limit. This column displays the limit on the hit count at which +the auto-disable, auto-delete, or auto-stop behavior takes effect. These +behaviors can be configured using the \fB::evset\fR dcmd, described below. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBDescription\fR\fR +.ad +.RS 15n +.rt +A description of the type of software event that is matched by the given +specifier. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBAction\fR\fR +.ad +.RS 15n +.rt +The callback string to execute when the corresponding software event occurs. +This callback is executed as if it had been typed at the command prompt. +.RE + +.RE + +.sp +.ne 2 +.mk +.na +\fB[\fIid\fR] \fB::evset\fR [\fB-/\fR\fB-dDestT\fR] [\fB-c\fR \fIcmd\fR] +[\fB-n\fR \fIcount\fR] \fIid\fR ...\fR +.ad +.sp .6 +.RS 4n +Modify the properties of one or more software event specifiers. The properties +are set for each specifier identified by the optional expression preceding the +dcmd and an optional list of arguments following the dcmd. The argument list is +interpreted as a list of decimal integers, unless an explicit radix is +specified. The \fB::evset\fR dcmd recognizes the following options: +.sp +.ne 2 +.mk +.na +\fB\fB-d\fR\fR +.ad +.RS 6n +.rt +Disables the event specifier when the hit count reaches the hit limit. If the +\fB-d\fR form of the option is given, this behavior is disabled. Once an event +specifier is disabled, the debugger removes any corresponding instrumentation +and ignores the corresponding software events until the specifier is +subsequently re-enabled. If the \fB-n\fR option is not present, the specifier +is disabled immediately. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-D\fR\fR +.ad +.RS 6n +.rt +Deletes the event specifier when the hit count reaches the hit limit. If the +\fB-D\fR form of the option is given, this behavior is disabled. The \fB-D\fR +option takes precedence over the \fB-d\fR option. The hit limit can be +configured using the \fB-n\fR option. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-e\fR\fR +.ad +.RS 6n +.rt +Enables the event specifier. If the \fB-e\fR form of the option is given, the +specifier is disabled. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-s\fR\fR +.ad +.RS 6n +.rt +Stops the target program when the hit count reaches the hit limit. If the +\fB-s\fR form of the option is given, this behavior is disabled. The \fB-s\fR +behavior tells the debugger to act as if the \fB::cont\fR were issued following +each execution of the specifier's callback, except for the \fIN\fRth execution, +where \fIN\fR is the current value of the specifier's hit limit. The \fB-s\fR +option takes precedence over both the \fB-D\fR option and the \fB-d\fR option. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-t\fR\fR +.ad +.RS 6n +.rt +Marks the event specifier as temporary. Temporary specifiers are automatically +deleted the next time the target stops, regardless of whether it stopped as the +result of a software event corresponding to the given specifier. If the +\fB-t\fR form of the option is given, the temporary marker is removed. The +\fB-t\fR option takes precedence over the \fB-T\fR option. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-T\fR\fR +.ad +.RS 6n +.rt +Marks the event specifier as sticky. Sticky specifiers are not deleted by +\fB::delete\fR \fBall\fR or \fB:z.\fR They can be deleted by specifying the +corresponding specifier \fBID\fR as an explicit argument to \fB::delete\fR. If +the \fB-T\fR form of the option is given, the sticky property is removed. The +default set of event specifiers are all initially marked sticky. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-c\fR\fR +.ad +.RS 6n +.rt +Executes the specified \fIcmd\fR string each time the corresponding software +event occurs in the target program. The current callback string can be +displayed using \fB::events\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-n\fR\fR +.ad +.RS 6n +.rt +Sets the current value of the hit limit to \fIcount\fR. If no hit limit is +currently set and the \fB-n\fR option does not accompany \fB-s\fR or D, the hit +limit is set to one. +.RE + +A summary of this information is available using \fB::help\fR \fBevset\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::files\fR\fR +.ad +.br +.na +\fB\fB$f\fR\fR +.ad +.sp .6 +.RS 4n +Print a list of the known source files (symbols of type \fISTT_FILE\fR present +in the various target symbol tables). +.RE + +.sp +.ne 2 +.mk +.na +\fB[\fIflt\fR] \fB::fltbp\fR [\fB-/\fR\fB-dDestT\fR] [\fB-c\fR \fIcmd\fR] +[\fB-n\fR \fIcount\fR] \fIflt\fR ...\fR +.ad +.sp .6 +.RS 4n +Trace the specified machine faults. The faults are identified using an optional +fault number preceding the dcmd, or a list of fault names or numbers (see +\fB<sys/fault.h>\fR) following the dcmd. The \fB-d\fR, \fB-D\fR, \fB-e\fR, +\fB-s\fR, \fB-t\fR, \fB-T\fR, \fB-c\fR, and \fB-n\fR options have the same +meaning as they do for the \fB::evset\fR dcmd. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fB\fIthread\fR\fR ] \fB::fpregs\fR\fR +.ad +.br +.na +\fB[ \fB\fIthread\fR\fR ] \fB$x\fR, \fB$X\fR, \fB$y\fR, \fB$Y\fR\fR +.ad +.sp .6 +.RS 4n +Print the floating-point register set of the representative thread. If a thread +is specified, the floating point registers of that thread are displayed. The +thread expression should be one of the thread identifiers described under +\fBThread Support\fR, above. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::formats\fR\fR +.ad +.sp .6 +.RS 4n +List the available output format characters for use with the \fB/\fR, \fB\e\fR, +\fB?\fR, and \fB=\fR formatting dcmds. The formats and their use is described +under \fBFormatting dcmds\fR, above. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::grep\fR \fIcommand\fR\fR +.ad +.sp .6 +.RS 4n +Evaluate the specified command string, and then print the old value of dot if +the new value of dot is non-zero. If the \fIcommand\fR contains whitespace or +metacharacters, it must be quoted. The \fB::grep\fR dcmd can be used in +pipelines to filter a list of addresses. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::help\fR [ \fIdcmd-name\fR ]\fR +.ad +.sp .6 +.RS 4n +With no arguments, the \fB::help\fR dcmd prints a brief overview of the help +facilities available in \fBmdb\fR. If a \fIdcmd-name\fR is specified, \fBmdb\fR +prints a usage summary for that dcmd. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIsignal\fR \fB:i\fR\fR +.ad +.sp .6 +.RS 4n +If the target is a live user process, ignore the specified signal and allow it +to be delivered transparently to the target. All event specifiers that are +tracing delivery of the specified signal is deleted from the list of traced +events. By default, the set of ignored signals is initialized to the complement +of the set of signals that cause a process to dump core by default (see +\fBsignal.h\fR(3HEAD)), except for \fBSIGINT\fR, which is traced by default. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB$i\fR\fR +.ad +.sp .6 +.RS 4n +Display the list of signals that are ignored by the debugger and that is +handled directly by the target. More information on traced signals can be +obtained using the \fB::events\fR dcmd. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::kill\fR\fR +.ad +.br +.na +\fB\fB:k\fR\fR +.ad +.sp .6 +.RS 4n +Forcibly terminate the target if it is a live user process. The target is also +forcibly terminated when the debugger exits if it was created by the debugger +using \fB::run\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB$l\fR\fR +.ad +.sp .6 +.RS 4n +Print the \fBLWPID\fR of the representative thread, if the target is a user +process. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB$L\fR\fR +.ad +.sp .6 +.RS 4n +Print the \fBLWPID\fRs of each \fBLWP\fR in the target, if the target is a user +process. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIaddress\fR ] \fB::list\fR \fItype\fR \fImember\fR [ \fIvariable-name\fR +]\fR +.ad +.sp .6 +.RS 4n +Walk through the elements of a linked list data structure and print the address +of each element in the list. The address of the first element in the list can +be specified using an optional address. Otherwise, the list is assumed to start +at the current value of dot. The type parameter must name a C struct or union +type and is used to describe the type of the list elements so that \fBmdb\fR +can read in objects of the appropriate size. The member parameter is used to +name the \fImember\fR of \fItype\fR that contains a pointer to the next list +element. The \fB::list\fR dcmd continues iterating until a \fBNULL\fR pointer +is encountered, the first element is reached again (a circular list), or an +error occurs while reading an element. If the optional \fIvariable-name\fR is +specified, the specified variable is assigned the value returned at each step +of the walk when \fBmdb\fR invokes the next stage of a pipeline. The +\fB::list\fR dcmd can only be used with objects that contain symbolic debugging +information designed for use with mdb. Refer to NOTES, \fBSymbolic Debugging +Information\fR, below for more information. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::load\fR [ \fB-s\fR ] \fImodule-name\fR\fR +.ad +.sp .6 +.RS 4n +Load the specified dmod. The module name can be given as an absolute or +relative path. If \fImodule-name\fR is a simple name (that is, does not contain +a '\fB/\fR'), \fBmdb\fR searches for it in the module library path. Modules +with conflicting names can not be loaded; the existing module must be unloaded +first. If the \fB-s\fR option is present, \fBmdb\fR remains silent and not +issue any error messages if the module is not found or could not be loaded. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::log\fR [ \fB-d\fR | [ \fB-e\fR ] \fIfilename\fR ]\fR +.ad +.br +.na +\fB\fB$>\fR [ \fIfilename\fR ]\fR +.ad +.sp .6 +.RS 4n +Enable or disable the output log. \fBmdb\fR provides an interactive logging +facility where both the input commands and standard output can be logged to a +file while still interacting with the user. The \fB-e\fR option enables logging +to the specified file, or re-enables logging to the previous log file if no +filename is given. The \fB-d\fR option disables logging. If the \fB$>\fR dcmd +is used, logging is enabled if a filename argument is specified; otherwise, +logging is disabled. If the specified log file already exists, \fBmdb\fR +appends any new log output to the file. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::map\fR \fIcommand\fR\fR +.ad +.sp .6 +.RS 4n +Map the value of dot to a corresponding value using the \fIcommand\fR specified +as a string argument, and then print the new value of dot. If the command +contains whitespace or metacharacters, it must be quoted. The \fB::map\fR dcmd +can be used in pipelines to transform the list of addresses into a new list of +addresses. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIaddress\fR ] \fB::mappings\fR [ \fIname\fR ]\fR +.ad +.br +.na +\fB[ \fI address\fR ] \fB$m\fR [ \fIname\fR ]\fR +.ad +.sp .6 +.RS 4n +Print a list of each mapping in the target's virtual address space, including +the address, size, and description of each mapping. If the dcmd is preceded by +an \fIaddress\fR, \fBmdb\fR only shows the mapping that contains the given +address. If a string \fIname\fR argument is given, \fBmdb\fR only shows the +mapping matching that description. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::next\fR [ \fISIG\fR ]\fR +.ad +.br +.na +\fB\fB:e\fR [ \fISIG\fR ]\fR +.ad +.sp .6 +.RS 4n +Step the target program one instruction, but step over subroutine calls. If an +optional signal name or number (see \fBsignal.h\fR(3HEAD)) is specified as an +argument, the signal is immediately delivered to the target as part of resuming +its execution. If no target program is currently running, \fB::next\fR starts a +new program running as if by \fB::run\fR and stop at the first instruction. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIaddress\fR ] \fB::nm\fR [ \fB-DPdghnopuvx\fR ] [ \fB-t\fR \fItypes\fR +]\fR +.ad +.br +.na +\fB#sp;#sp;[ \fB-f\fR \fIformat\fR ] [ \fIobject\fR ]\fR +.ad +.sp .6 +.RS 4n +Print the symbol tables associated with the current target. If an optional +address preceding the dcmd is specified, only the symbol table entry for the +symbol corresponding to \fIaddress\fR is displayed. If an \fIobject\fR is +specified, only the symbol table for this load object is displayed. The +\fB::nm\fR dcmd also recognizes the following options: +.sp +.ne 2 +.mk +.na +\fB\fB-D\fR\fR +.ad +.RS 27n +.rt +Prints \fB\&.dynsym\fR (dynamic symbol table) instead of \fB\&.symtab\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-P\fR\fR +.ad +.RS 27n +.rt +Prints the private symbol table instead of \fB\&.symtab\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-d\fR\fR +.ad +.RS 27n +.rt +Prints value and size fields in decimal. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-g\fR\fR +.ad +.RS 27n +.rt +Prints only global symbols. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-h\fR\fR +.ad +.RS 27n +.rt +Suppresses the header line. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-n\fR\fR +.ad +.RS 27n +.rt +Sorts symbols by name. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-o\fR\fR +.ad +.RS 27n +.rt +Prints value and size fields in octal. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-p\fR\fR +.ad +.RS 27n +.rt +Prints symbols as a series of \fB::nmadd\fR commands. This option can be used +with \fB-P\fR to produce a macro file that can be subsequently read into the +debugger with \fB$<\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-u\fR\fR +.ad +.RS 27n +.rt +Prints only undefined symbols. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-v\fR\fR +.ad +.RS 27n +.rt +Sorts symbols by value. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-x\fR\fR +.ad +.RS 27n +.rt +Prints value and size fields in hexadecimal. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-t\fR \fItype\fR[,\fItype\fR ... ]\fR +.ad +.RS 27n +.rt +Prints only symbols of the specified type(s). The valid \fItype\fR argument +strings are: +.sp +.ne 2 +.mk +.na +\fB\fBnoty\fR\fR +.ad +.RS 8n +.rt +\fISTT_NOTYPE\fR +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBobjt\fR\fR +.ad +.RS 8n +.rt +\fISTT_OBJECT\fR +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBfunc\fR\fR +.ad +.RS 8n +.rt +\fISTT_FUNC\fR +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBsect\fR\fR +.ad +.RS 8n +.rt +\fISTT_SECTION\fR +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBfile\fR\fR +.ad +.RS 8n +.rt +\fISTT_FILE\fR +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBcomm\fR\fR +.ad +.RS 8n +.rt +\fISTT_COMMON\fR +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBtls\fR\fR +.ad +.RS 8n +.rt +\fISTT_TLS\fR +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBregi\fR\fR +.ad +.RS 8n +.rt +\fISTT_SPARC_REGISTER\fR +.RE + +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-f\fR \fIformat\fR[,\fIformat\fR ... ]\fR +.ad +.RS 27n +.rt +Prints only the specified symbol information. The valid \fIformat\fR argument +strings are: +.sp +.ne 2 +.mk +.na +\fB\fBndx\fR\fR +.ad +.RS 9n +.rt +symbol table index +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBval\fR\fR +.ad +.RS 9n +.rt +symbol value +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBsize\fR\fR +.ad +.RS 9n +.rt +size in bytes +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBtype\fR\fR +.ad +.RS 9n +.rt +symbol type +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBbind\fR\fR +.ad +.RS 9n +.rt +binding +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBoth\fR\fR +.ad +.RS 9n +.rt +other +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBshndx\fR\fR +.ad +.RS 9n +.rt +section index +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBname\fR\fR +.ad +.RS 9n +.rt +symbol name +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBctype\fR\fR +.ad +.RS 9n +.rt +C type for symbol (if known) +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBobj\fR\fR +.ad +.RS 9n +.rt +object which defines symbol +.RE + +.RE + +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIvalue\fR \fB::nmadd\fR [ \fB-fo\fR ] [ \fB-e\fR \fIend\fR ] [ \fB-s\fR +\fIsize\fR ] \fIname \fR\fR +.ad +.sp .6 +.RS 4n +Add the specified symbol \fIname\fR to the private symbol table. \fBmdb\fR +provides a private, configurable symbol table that can be used to interpose on +the target's symbol table, as described under \fBSymbol Name Resolution\fR +above. The \fB::nmadd\fR dcmd also recognizes the following options: +.sp +.ne 2 +.mk +.na +\fB\fB-e\fR\fR +.ad +.RS 6n +.rt +Sets the size of the symbol to \fIend\fR - \fIvalue\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-f\fR\fR +.ad +.RS 6n +.rt +Sets the type of the symbol to \fBSTT_FUNC\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-o\fR\fR +.ad +.RS 6n +.rt +Sets the type of the symbol to \fBSTT_OBJECT\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-s\fR\fR +.ad +.RS 6n +.rt +Sets the size of the symbol to \fIsize\fR. +.RE + +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::nmdel\fR \fIname\fR\fR +.ad +.sp .6 +.RS 4n +Delete the specified symbol \fIname\fR from the private symbol table. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::objects\fR [ \fB-v\fR ]\fR +.ad +.sp .6 +.RS 4n +Print a map of the target's virtual address space, showing only those mappings +that correspond to the primary mapping (usually the text section) of each of +the known load objects. The \fB-v\fR option displays the version of each load +object. Version information is not available for all load objects. Load objects +without version information is listed as having a version of "\fBUnknown\fR" in +the output for the \fB-v\fR option. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::offsetof\fR \fItype member\fR\fR +.ad +.sp .6 +.RS 4n +Print the offset of the specified \fImember\fR of the specified \fItype\fR. The +\fItype\fR should be the name of a C structure. The offset is printed in bytes, +unless the member is a bit-field, in which case the offset can be printed in +bits. The output is always suffixed with the appropriate units for clarity. The +type name can use the backquote (\fB`\fR) scoping operator described under +\fBSymbol Name Resolution\fR, above. The \fB::offsetof\fR dcmd can only be used +with objects that contain symbolic debugging information designed for use with +\fBmdb\fR. Refer to NOTES, \fBSymbolic Debugging Information\fR, below for more +information. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIaddress\fR \fB::print\fR [ \fB-aCdiLptx\fR ] [ \fB-c\fR \fIlim\fR ]\fR +.ad +.br +.na +\fB#sp;#sp;[ \fB-l\fR \fIlim\fR ] [ \fItype\fR [ \fImember\fR ... ] ]\fR +.ad +.sp .6 +.RS 4n +Print the data structure at the specified virtual \fIaddress\fR using the given +\fItype\fR information. The \fItype\fR parameter can name a C struct, union, +enum, fundamental integer type, or a pointer to any of these types. If the type +name contains whitespace (for example, "\fBstruct foo\fR"), it must be enclosed +in single or double quotes. The type name can use the backquote (\fB`\fR) +scoping operator described under \fBSymbol Name Resolution\fR, above. If the +type is a structured type, the \fB::print\fR dcmd recursively prints each +member of the struct or union. If the \fItype\fR argument is not present and a +static or global \fISTT_OBJECT\fR symbol matches the address, \fB::print\fR +infers the appropriate type automatically. If the \fItype\fR argument is +specified, it can be followed by an optional list of \fImember\fR expressions, +in which case only those members and submembers of the specified \fItype\fR are +displayed. If \fItype\fR contains other structured types, each member string +can refer to a sub-structure element by forming a list of member names +separated by period ('\fB\&.\fR') delimiters. The \fB::print\fR dcmd can only +be used with objects that contain symbolic debugging information designed for +use with \fBmdb\fR. Refer to NOTES, \fBSymbolic Debugging Information\fR, below +for more information. After displaying the data structure, \fB::print\fR +increments dot by the size of \fItype\fR in bytes. +.sp +If the \fB-a\fR option is present, the address of each member is displayed. If +the \fB-p\fR option is present, \fB::print\fR interprets \fIaddress\fR as a +physical memory address instead of a virtual memory address. If the \fB-t\fR +option is present, the type of each member is displayed. If the \fB-d\fR or +\fB-x\fR options are present, all integers are displayed in decimal (\fB-d\fR) +or hexadecimal (\fB-x\fR). By default, a heuristic is used to determine if the +value should be displayed in decimal or hexadecimal. The number of characters +in a character array that is read and displayed as a string can be limited with +the \fB-c\fR option. If the \fB-C\fR option is present, no limit is enforced. +The number of elements in a standard array that is read and displayed can be +limited with the \fB-l\fR option. If the \fB-L\fR option is present, no limit +is enforced and all array elements are shown. The default values for \fB-c\fR +and \fB-l\fR can be modified using \fB::set\fR or the \fB-o\fR command-line +option as described under OPTIONS. +.sp +If the \fB-i\fR option is specified, the address value is interpreted as an +immediate value to be printed. You must give a type with which to interpret the +value. If the type is smaller than 64 bits, the immediate value is interpreted +as if it were the size of the type. The \fB-i\fR option cannot be used in +conjunction with the \fB-p\fR option. If the \fB-a\fR option is given, the +addresses shown are byte offsets starting at zero. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::quit\fR\fR +.ad +.br +.na +\fB\fB$q\fR\fR +.ad +.sp .6 +.RS 4n +Quit the debugger. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIthread\fR ] \fB::regs\fR\fR +.ad +.br +.na +\fB[ \fIthread\fR ] \fB$r\fR\fR +.ad +.sp .6 +.RS 4n +Print the general purpose register set of the representative thread. If a +thread is specified, the general purpose register set of that thread is +displayed. The thread expression should be one of the thread identifiers +described under \fBThread Support\fR, above. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::release\fR [ \fB-a\fR ]\fR +.ad +.br +.na +\fB\fB:R\fR [ \fB-a\fR ]\fR +.ad +.sp .6 +.RS 4n +Release the previously attached process or core file. If the \fB-a\fR option is +present, the process is released and left stopped and abandoned. It can +subsequently be continued by \fBprun\fR(1) (see \fBproc\fR(1)) or it can be +resumed by applying \fBmdb\fR or another debugger. By default, a released +process is forcibly terminated if it was created by \fBmdb\fR using +\fB::run\fR, or it is released and set running if it was attached to by +\fBmdb\fR using the \fB-p\fR option or using the \fB::attach\fR or \fB:A\fR +dcmds. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::run\fR [ \fIargs\fR . . . ]\fR +.ad +.br +.na +\fB\fB:r\fR [ \fIargs\fR . . . ]\fR +.ad +.sp .6 +.RS 4n +Start a new target program running with the specified arguments and attach to +it. The arguments are not interpreted by the shell. If the debugger is already +examining a live running program, it first detaches from this program as if by +\fB::release\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::set\fR [ \fB-wF\fR ] [ \fB-/\fR\fB-o\fR \fIoption\fR ] [ \fB-s\fR +\fIdistance\fR ] [ \fB-I\fR \fIpath\fR ]\fR +.ad +.br +.na +\fB#sp;#sp;[ \fB-L\fR \fIpath\fR ] [ \fB-P\fR \fIprompt\fR ]\fR +.ad +.sp .6 +.RS 4n +Get or set miscellaneous debugger properties. If no options are specified, the +current set of debugger properties is displayed. The \fB::set\fR dcmd +recognizes the following options: +.sp +.ne 2 +.mk +.na +\fB\fB-F\fR\fR +.ad +.RS 6n +.rt +Forcibly takes over the next user process that \fB::attach\fR is applied to, as +if \fBmdb\fR had been executed with the \fB-F\fR option on the command line. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-I\fR\fR +.ad +.RS 6n +.rt +Sets the default path for locating macro files. The path argument can contain +any of the special tokens described for the \fB-I\fR command-line option under +OPTIONS. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-L\fR\fR +.ad +.RS 6n +.rt +Sets the default path for locating debugger modules. The path argument can +contain any of the special tokens described for the \fB-I\fR command-line +option under OPTIONS. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-o\fR\fR +.ad +.RS 6n +.rt +Enables the specified debugger option. If the \fB-o\fR form is used, the option +is disabled. The option strings are described along with the \fB-o\fR +command-line option under OPTIONS. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-P\fR\fR +.ad +.RS 6n +.rt +Sets the command prompt to the specified prompt string. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-s\fR\fR +.ad +.RS 6n +.rt +Sets the symbol matching distance to the specified distance. Refer to the +description of the \fB-s\fR command-line option under OPTIONS for more +information. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-w\fR\fR +.ad +.RS 6n +.rt +Re-opens the target for writing, as if \fBmdb\fR had been executed with the +\fB-w\fR option on the command line. +.RE + +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::showrev\fR [ \fB-pv\fR ]\fR +.ad +.sp .6 +.RS 4n +Display revision information for the hardware and software. With no options +specified, general system information is displayed. The \fB-v\fR option +displays version information for all load objects, whereas the \fB-p\fR option +displays the version information only for the load objects that have been +installed on the system as part of a patch. Version information is not +available for all load objects. Load objects without version information is +omitted from the output for the \fB-p\fR option and is listed as having a +version of "\fBUnknown\fR" in the output for the \fB-v\fR option. +.RE + +.sp +.ne 2 +.mk +.na +\fB[\fIsignal\fR] \fB::sigbp\fR [\fB-/\fR\fB-dDestT\fR] [\fB-c\fR \fIcmd\fR] +[\fB-n\fR \fIcount\fR] \fISIG\fR ...\fR +.ad +.br +.na +\fB[\fIsignal\fR] \fB:t\fR [\fB-/\fR\fB-dDestT\fR] [\fB-c\fR \fIcmd\fR] +[\fB-n\fR \fIcount\fR] \fISIG\fR ...\fR +.ad +.sp .6 +.RS 4n +Trace delivery of the specified signals. The signals are identified using an +optional signal number preceding the dcmd, or a list of signal names or numbers +(see \fBsignal.h\fR(3HEAD)) following the dcmd. The \fB-d\fR, \fB-D\fR, +\fB-e\fR, \fB-s\fR, \fB-t\fR, \fB-T\fR, \fB-c\fR, and \fB-n\fR options have the +same meaning as they do for the \fB::evset\fR dcmd. Initially, the set of +signals that cause the process to dump core by default (see +\fBsignal.h\fR(3HEAD)) and \fBSIGINT\fR are traced. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::sizeof\fR \fItype\fR \fR +.ad +.sp .6 +.RS 4n +Print the size of the specified \fItype\fR in bytes. The \fItype\fR parameter +can name a C struct, union, enum, fundamental integer type, or a pointer to any +of these types. The type name can use the backquote (\fB`\fR) scoping operator +described under \fBSymbol Name Resolution\fR, above. The \fB::sizeof\fR dcmd +can only be used with objects that contain symbolic debugging information +designed for use with \fBmdb\fR. Refer to NOTES, \fBSymbolic Debugging +Information\fR, below for more information. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIaddress\fR ] \fB::stack \fR [ \fIcount\fR ]\fR +.ad +.br +.na +\fB[ \fI address\fR ] \fB$c\fR [ \fIcount\fR ]\fR +.ad +.sp .6 +.RS 4n +Print a C stack backtrace. If the dcmd is preceded by an explicit +\fIaddress\fR, a backtrace beginning at this virtual memory address is +displayed. Otherwise the stack of the representative thread is displayed. If an +optional count value is given as an argument, no more than \fIcount\fR +arguments are displayed for each stack frame in the output. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::status\fR\fR +.ad +.sp .6 +.RS 4n +Print a summary of information related to the current target. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::step\fR [ \fBover\fR | \fBout\fR ] [ \fISIG\fR ]\fR +.ad +.br +.na +\fB\fB:s\fR [ \fISIG\fR ]\fR +.ad +.br +.na +\fB\fB:u\fR [ \fISIG\fR ]\fR +.ad +.sp .6 +.RS 4n +Step the target program one instruction. If an optional signal name or number +(see \fBsignal.h\fR(3HEAD)) is specified as an argument, the signal is +immediately delivered to the target as part of resuming its execution. If the +optional "\fBover\fR" argument is specified, \fB::step\fR steps over subroutine +calls. The \fB::step\fR \fBover\fR argument is the same as the \fB::next\fR +dcmd. If the optional "\fBout\fR" argument is specified, the target program +continues until the representative thread returns from the current function. If +no target program is currently running, \fB::step\fR \fBout\fR starts a new +program running as if by \fB::run\fR and stop at the first instruction. The +\fB:s\fR dcmd is the same as \fB::step\fR. The \fB:u\fR dcmd is the same as +\fB::step\fR \fBout\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIsyscall\fR ] \fB::sysbp\fR [ \fB-/\fR\fB-dDestT\fR ] [ \fB-io\fR ] [ +\fB-c\fR \fIcmd\fR ]\fR +.ad +.br +.na +\fB#sp;#sp;[ \fB-n\fR \fIcount\fR ] \fIsyscall\fR...\fR +.ad +.sp .6 +.RS 4n +Trace entry to or exit from the specified system calls. The system calls are +identified using an optional system call number preceding the dcmd, or a list +of system call names or numbers (see \fB<sys/syscall.h>\fR) following the dcmd. +If the \fB-i\fR option is specified (the default), the event specifiers trigger +on entry into the kernel for each system call. If the \fB-o\fR option is +specified, the event specifiers trigger on exit out from the kernel. The +\fB-d\fR, \fB-D\fR, \fB-e\fR, \fB-s\fR, \fB-t\fR, \fB-T\fR, \fB-c\fR, and +\fB-n\fR options have the same meaning as they do for the \fB::evset\fR dcmd. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIthread\fR \fB::tls\fR \fIsymbol\fR\fR +.ad +.sp .6 +.RS 4n +Print the address of the storage for the specified thread-local storage +(\fBTLS\fR) symbol in the context of the specified thread. The thread +expression should be one of the thread identifiers described under \fBThread +Support\fR, above. The symbol name can use any of the scoping operators +described under \fBSymbol Name Resolution\fR, above. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::typeset\fR [ \fB-/\fR\fB-t\fR] \fIvariable-name\fR . . .\fR +.ad +.sp .6 +.RS 4n +Set attributes for named variables. If one or more variable names are +specified, they are defined and set to the value of dot. If the \fB-t\fR option +is present, the user-defined tag associated with each variable is set. If the +\fB-t\fR option is present, the tag is cleared. If no variable names are +specified, the list of variables and their values is printed. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::unload\fR \fImodule-name\fR\fR +.ad +.sp .6 +.RS 4n +Unload the specified dmod. The list of active dmods can be printed using the +\fB::dmods\fR dcmd. Built-in modules can not be unloaded. Modules that are busy +(that is, provide dcmds that are currently executing) can not be unloaded. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::unset\fR \fIvariable-name\fR . . .\fR +.ad +.sp .6 +.RS 4n +Unset (remove) the specified variable(s) from the list of defined variables. +Some variables exported by \fBmdb\fR are marked as persistent, and can not be +unset by the user. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::vars\fR [ \fB-npt\fR] \fR +.ad +.sp .6 +.RS 4n +Print a listing of named variables. If the \fB-n\fR option is present, the +output is restricted to variables that currently have non-zero values. If the +\fB-p\fR option is present, the variables are printed in a form suitable for +re-processing by the debugger using the \fB$<\fR dcmd. This option can be used +to record the variables to a macro file and then restore these values later. If +the \fB-t\fR option is present, only the tagged variables are printed. +Variables can be tagged using the \fB-t\fR option of the \fB::typeset\fR dcmd. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::version\fR\fR +.ad +.sp .6 +.RS 4n +Print the debugger version number. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIaddress\fR \fB::vtop\fR [\fB-a\fR \fIas\fR]\fR +.ad +.sp .6 +.RS 4n +Print the physical address mapping for the specified virtual address, if +possible. The \fB::vtop\fR dcmd is only available when examining a kernel +target, or when examining a user process inside a kernel crash dump (after a +\fB::context\fR dcmd has been issued). +.sp +When examining a kernel target from the kernel context, the \fB-a\fR option can +be used to specify the address (\fIas\fR) of an alternate address space +structure that should be used for the virtual to physical translation. By +default, the kernel's address space is used for translation. This option is +available for active address spaces even when the dump content only contains +kernel pages. +.RE + +.sp +.ne 2 +.mk +.na +\fB[ \fIaddress\fR ] \fB::walk\fR \fIwalker-name\fR [ \fIvariable-name\fR ]\fR +.ad +.sp .6 +.RS 4n +Walk through the elements of a data structure using the specified walker. The +available walkers can be listed using the \fB::walkers\fR dcmd. Some walkers +operate on a global data structure and do not require a starting address. For +example, walk the list of proc structures in the kernel. Other walkers operate +on a specific data structure whose address must be specified explicitly. For +example, given a pointer to an address space, walk the list of segments. When +used interactively, the \fB::walk\fR dcmd prints the address of each element of +the data structure in the default base. The dcmd can also be used to provide a +list of addresses for a pipeline. The walker name can use the backquote +(\fB`\fR) scoping operator described under \fBdcmd and Walker Name +Resolution\fR, above. If the optional \fIvariable-name\fR is specified, the +specified variable is assigned the value returned at each step of the walk when +\fBmdb\fR invokes the next stage of the pipeline. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::walkers\fR\fR +.ad +.sp .6 +.RS 4n +List the available walkers and print a brief description for each one. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::whence\fR [ \fB-v\fR ] \fIname\fR . . .\fR +.ad +.br +.na +\fB\fB::which\fR [ \fB-v\fR ] \fIname\fR ...\fR +.ad +.sp .6 +.RS 4n +Print the dmod that exports the specified dcmds and walkers. These dcmds can be +used to determine which dmod is currently providing the global definition of +the given dcmd or walker. Refer to the section on \fBdcmd and Walker Name +Resolution\fR above for more information on global name resolution. The +\fB-v\fR option causes the dcmd to print the alternate definitions of each dcmd +and walker in order of precedence. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIaddr\fR [ ,\fIlen\fR ]\fB::wp\fR [ \fB-/\fR\fB-dDestT\fR ] [ \fB-rwx\fR +] [ \fB-c\fR \fIcmd\fR ]\fR +.ad +.br +.na +\fB#sp;#sp; [ \fB-n\fR \fIcount\fR ]\fR +.ad +.br +.na +\fB\fIaddr\fR [ ,\fIlen\fR ] \fB:a\fR [ \fIcmd\fR . . . ]\fR +.ad +.br +.na +\fB\fIaddr\fR [ ,\fIlen\fR ] \fB:p\fR [ \fIcmd\fR . \&. . ]\fR +.ad +.br +.na +\fB\fIaddr\fR [ ,\fIlen\fR ] \fB:w\fR [ \fIcmd\fR . . . ]\fR +.ad +.sp .6 +.RS 4n +Set a watchpoint at the specified address. The length in bytes of the watched +region can be set by specifying an optional repeat count preceding the dcmd. If +no length is explicitly set, the default is one byte. The \fB::wp\fR dcmd +allows the watchpoint to be configured to trigger on any combination of read +(\fB-r\fR option), write (\fB-w\fR option), or execute (\fB-x\fR option) +access. The \fB-d\fR, \fB-D\fR, \fB-e\fR, \fB-s\fR, \fB-t\fR, \fB-T\fR, +\fB-c\fR, and \fB-n\fR options have the same meaning as they do for the +\fB::evset\fR dcmd. The \fB:a\fR dcmd sets a read access watchpoint at the +specified address. The \fB:p\fR dcmd sets an execute access watchpoint at the +specified address. The \fB:w\fR dcmd sets a write access watchpoint at the +specified address. The arguments following the \fB:a\fR, \fB:p\fR, and \fB:w\fR +dcmds are concatenated together to form the callback string. If this string +contains meta-characters, it must be quoted. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB::xdata\fR\fR +.ad +.sp .6 +.RS 4n +List the external data buffers exported by the current target. External data +buffers represent information associated with the target that can not be +accessed through standard target facilities (that is, an address space, symbol +table, or register set). These buffers can be consumed by dcmds; for more +information, refer to the \fISolaris Modular Debugger Guide\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB:z\fR\fR +.ad +.sp .6 +.RS 4n +Delete all event specifiers from the list of traced software events. Event +specifiers can also be deleted using \fB::delete\fR. +.RE + +.SH OPTIONS +.sp +.LP +The following options are supported: +.sp +.ne 2 +.mk +.na +\fB\fB-A\fR\fR +.ad +.RS 15n +.rt +Disables automatic loading of \fBmdb\fR modules. By default, \fBmdb\fR attempts +to load debugger modules corresponding to the active shared libraries in a user +process or core file, or to the loaded kernel modules in the live operating +system or an operating system crash dump. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-f\fR\fR +.ad +.RS 15n +.rt +Forces raw file debugging mode. By default, \fBmdb\fR attempts to infer whether +the object and core file operands refer to a user executable and core dump or +to a pair of operating system crash dump files. If the file type cannot be +inferred, the debugger defaults to examining the files as plain binary data. +The \fB-f\fR option forces \fBmdb\fR to interpret the arguments as a set of raw +files to examine. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-F\fR\fR +.ad +.RS 15n +.rt +Forcibly takes over the specified user process, if necessary. By default, +\fBmdb\fR refuses to attach to a user process that is already under the control +of another debugging tool, such as \fBtruss\fR(1). With the \fB-F\fR option, +\fBmdb\fR attaches to these processes anyway. This can produce unexpected +interactions between \fBmdb\fR and the other tools attempting to control the +process. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-I\fR \fIpath\fR\fR +.ad +.RS 15n +.rt +Sets default path for locating macro files. Macro files are read using the +\fB$<\fR or \fB$<<\fR dcmds. The path is a sequence of directory names +delimited by colon (\fB:\fR) characters. The \fB-I\fR \fBinclude\fR path and +\fB-L\fR \fBlibrary\fR path (see below) can also contain any of the following +tokens: +.sp +.ne 2 +.mk +.na +\fB%i\fR +.ad +.RS 6n +.rt +Expands to the current instruction set architecture (\fBISA\fR) name +('sparc', 'sparcv9', or 'i386'). +.RE + +.sp +.ne 2 +.mk +.na +\fB%o\fR +.ad +.RS 6n +.rt +Expands to the old value of the path being modified. This is useful for +appending or prepending directories to an existing path. +.RE + +.sp +.ne 2 +.mk +.na +\fB%p\fR +.ad +.RS 6n +.rt +Expands to the current platform string (either \fBuname\fR \fB-i\fR or the +platform string stored in the process core file or crash dump). +.RE + +.sp +.ne 2 +.mk +.na +\fB%r\fR +.ad +.RS 6n +.rt +Expands to the pathname of the root directory. An alternate root directory can +be specified using the \fB-R\fR option. If no \fB-R\fR option is present, the +root directory is derived dynamically from the path to the \fBmdb\fR executable +itself. For example, if \fB/bin/mdb\fR is executed, the root directory is +\fB/\fR. If \fB/net/hostname/bin/mdb\fR were executed, the root directory would +be derived as \fB/net/hostname\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB%t\fR +.ad +.RS 6n +.rt +Expands to the name of the current target. This is either be the literal +string '\fBproc\fR' (a user process or user process core file), '\fBkvm\fR' (a kernel +crash dump or the live operating system), or '\fBraw\fR' (a raw file). +.RE + +The default include path for 32-bit \fBmdb\fR is: +.sp +.in +2 +.nf +%r/usr/platform/%p/lib/adb:%r/usr/lib/adb +.fi +.in -2 +.sp + +The default include path for 64-bit \fBmdb\fR is: +.sp +.in +2 +.nf +%r/usr/platform/%p/lib/adb/%i:%r/usr/lib/adb/%i +.fi +.in -2 +.sp + +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-k\fR\fR +.ad +.RS 15n +.rt +Forces kernel debugging mode. By default, \fBmdb\fR attempts to infer whether +the object and core file operands refer to a user executable and core dump, or +to a pair of operating system crash dump files. The \fB-k\fR option forces +\fBmdb\fR to assume these files are operating system crash dump files. If no +object or core operand is specified, but the \fB-k\fR option is specified, +\fBmdb\fR defaults to an object file of \fB/dev/ksyms\fR and a core file of +\fB/dev/kmem\fR. Read access to \fB/dev/kmem\fR is restricted to group sys. +Write access requires ALL privileges. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-K\fR\fR +.ad +.RS 15n +.rt +Load \fBkmdb\fR, stop the live running operating system kernel, and proceed to +the \fBkmdb\fR debugger prompt. This option should only be used on the system +console, as the subsequent \fBkmdb\fR prompt appears on the system console. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-L\fR \fIpath\fR\fR +.ad +.RS 15n +.rt +Sets default path for locating debugger modules. Modules are loaded +automatically on startup or using the \fB::load\fR dcmd. The path is a sequence +of directory names delimited by colon (\fB:\fR) characters. The \fB-L\fR +library path can also contain any of the tokens shown for \fB-I\fR above. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-m\fR\fR +.ad +.RS 15n +.rt +Disables demand-loading of kernel module symbols. By default, \fBmdb\fR +processes the list of loaded kernel modules and performs demand loading of +per-module symbol tables. If the \fB-m\fR option is specified, \fBmdb\fR does +not attempt to process the kernel module list or provide per-module symbol +tables. As a result, \fBmdb\fR modules corresponding to active kernel modules +are not loaded on startup. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-M\fR\fR +.ad +.RS 15n +.rt +Preloads all kernel module symbols. By default, \fBmdb\fR performs +demand-loading for kernel module symbols: the complete symbol table for a +module is read when an address is that module's text or data section is +referenced. With the \fB-M\fR option, \fBmdb\fR loads the complete symbol table +of all kernel modules during startup. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-o\fR \fIoption\fR\fR +.ad +.RS 15n +.rt +Enables the specified debugger option. If the \fB-o\fR form of the option is +used, the specified \fIoption\fR is disabled. Unless noted below, each option +is off by default. \fBmdb\fR recognizes the following \fIoption\fR arguments: +.sp +.ne 2 +.mk +.na +\fB\fBadb\fR\fR +.ad +.RS 25n +.rt +Enables stricter \fBadb\fR(1) compatibility. The prompt is set to the empty +string and many \fBmdb\fR features, such as the output pager, is disabled. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBarray_mem_limit=\fR\fIlimit\fR\fR +.ad +.RS 25n +.rt +Sets the default limit on the number of array members that \fB::print\fR +displays. If \fIlimit\fR is the special token \fBnone\fR, all array members are +displayed by default. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBarray_str_limit=\fR\fIlimit\fR\fR +.ad +.RS 25n +.rt +Sets the default limit on the number of characters that \fB::print\fR attempts +to display as an ASCII string when printing a char array. If \fIlimit\fR is the +special token \fBnone\fR, the entire char array is displayed as a string by +default. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBfollow_exec_mode=\fR\fImode\fR\fR +.ad +.RS 25n +.rt +Sets the debugger behavior for following an \fBexec\fR(2) system call. The +\fImode\fR should be one of the following named constants: +.sp +.ne 2 +.mk +.na +\fB\fBask\fR\fR +.ad +.RS 10n +.rt +If stdout is a terminal device, the debugger stops after the \fBexec\fR(2) +system call has returned and then prompts the user to decide whether to follow +the exec or stop. If stdout is not a terminal device, the \fBask\fR mode +defaults to \fBstop\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBfollow\fR\fR +.ad +.RS 10n +.rt +The debugger follows the exec by automatically continuing the target process +and resetting all of its mappings and symbol tables based on the new +executable. The \fBfollow\fR behavior is discussed in more detail under NOTES, +\fBInteraction with Exec\fR, below. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBstop\fR\fR +.ad +.RS 10n +.rt +The debugger stops following return from the exec system call. The \fBstop\fR +behavior is discussed in more detail under NOTES, \fBInteraction with Exec\fR, +below. +.RE + +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBfollow_fork_mode=\fR\fImode\fR\fR +.ad +.RS 25n +.rt +Sets the debugger behavior for following a \fBfork\fR(2), \fBfork1\fR(2), or +\fBvfork\fR(2) system call. The \fImode\fR should be one of the following named +constants: +.sp +.ne 2 +.mk +.na +\fB\fBask\fR\fR +.ad +.RS 10n +.rt +If stdout is a terminal device, the debugger stops after the \fBfork\fR(2) +system call has returned and then prompts the user to decide whether to follow +the parent or child. If stdout is not a terminal device, the \fBask\fR mode +defaults to \fBparent\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBparent\fR\fR +.ad +.RS 10n +.rt +The debugger follows the parent process, and detaches from the child process +and sets it running. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBchild\fR\fR +.ad +.RS 10n +.rt +The debugger follows the child process, and detaches from the parent process +and sets it running. +.RE + +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBignoreeof\fR\fR +.ad +.RS 25n +.rt +The debugger does not exit when an \fBEOF\fR sequence (\fB^D\fR) is entered at +the terminal. The \fB::quit\fR dcmd must be used to quit. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBnostop\fR\fR +.ad +.RS 25n +.rt +Does not stop a user process when attaching to it when the \fB-p\fR option is +specified or when the \fB::attach\fR or \fB:A\fR dcmds are applied. The +\fBnostop\fR behavior is described in more detail under NOTES, \fBProcess +Attach and Release\fR, below. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBpager\fR\fR +.ad +.RS 25n +.rt +Enables the output pager (default). +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBrepeatlast\fR\fR +.ad +.RS 25n +.rt +If a \fINEWLINE\fR is entered as the complete command at the terminal, +\fBmdb\fR repeats the previous command with the current value of dot. This +option is implied by \fB-o\fR \fBadb\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBshowlmid\fR\fR +.ad +.RS 25n +.rt +\fBmdb\fR provides support for symbol naming and identification in user +applications that make use of link maps other than \fILM_ID_BASE\fR and +\fILM_ID_LDSO\fR, as described in \fBSymbol Name Resolution\fR, above. Symbols +on link maps other than \fILM_ID_BASE\fR or \fILM_ID_LDSO\fR is shown as +\fBLMlmid`library`symbol\fR, where \fBlmid\fR is the link-map \fBID\fR in the +default output radix (16). The user can optionally configure \fBmdb\fR to show +the link-map \fBID\fR scope of all symbols and objects, including those +associated with \fILM_ID_BASE\fR and \fILM_ID_LDSO\fR, by enabling the +\fBshowlmid\fR option. Built-in dcmds that deal with object file names displays +link-map \fBID\fRs according to the value of \fBshowlmid\fR above, including +\fB::nm\fR, \fB::mappings\fR, \fB$m\fR, and \fB::objects\fR. +.RE + +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-p\fR \fIpid\fR\fR +.ad +.RS 15n +.rt +Attaches to and stops the specified process-id. \fBmdb\fR uses the +\fB/proc/\fIpid\fR/object/a.out\fR file as the executable file pathname. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-P\fR \fIprompt\fR\fR +.ad +.RS 15n +.rt +Sets the command prompt. The default prompt is '\fB>\fR '. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-R\fR \fIroot\fR\fR +.ad +.RS 15n +.rt +Sets root directory for pathname expansion. By default, the root directory is +derived from the pathname of the \fBmdb\fR executable itself. The root +directory is substituted in place of the \fB%r\fR token during pathname +expansion. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-s\fR \fIdistance\fR\fR +.ad +.RS 15n +.rt +Sets the symbol matching distance for address-to-symbol-name conversions to the +specified \fIdistance\fR. By default, \fBmdb\fR sets the distance to zero, +which enables a smart-matching mode. Each \fBELF\fR symbol table entry includes +a value V and size S, representing the size of the function or data object in +bytes. In smart mode, \fBmdb\fR matches an address A with the given symbol if A +is in the range [ V, V + S ). If any non-zero distance is specified, the same +algorithm is used, but S in the expression above is always the specified +absolute distance and the symbol size is ignored. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-S\fR\fR +.ad +.RS 15n +.rt +Suppresses processing of the user's \fB~/.mdbrc\fR file. By default, \fBmdb\fR +reads and processes the macro file \fB\&.mdbrc\fR if one is present in the +user's home directory, as defined by $\fBHOME\fR. If the \fB-S\fR option is +present, this file is not read. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-u\fR\fR +.ad +.RS 15n +.rt +Forces user debugging mode. By default, \fBmdb\fR attempts to infer whether the +object and core file operands refer to a user executable and core dump, or to a +pair of operating system crash dump files. The \fB-u\fR option forces \fBmdb\fR +to assume these files are not operating system crash dump files. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-U\fR\fR +.ad +.RS 15n +.rt +Unload \fBkmdb\fR if it is loaded. You should unload \fBkmdb\fR when it is not +in use to release the memory used by the kernel debugger back to the free +memory available to the operating system. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-V\fR \fIversion\fR\fR +.ad +.RS 15n +.rt +Sets disassembler version. By default, \fBmdb\fR attempts to infer the +appropriate disassembler version for the debug target. The disassembler can be +set explicitly using the \fB-V\fR option. The \fB::disasms\fR dcmd lists the +available disassembler versions. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-w\fR\fR +.ad +.RS 15n +.rt +Opens the specified object and core files for writing. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-W\fR\fR +.ad +.RS 15n +.rt +Permit access to memory addresses that are mapped to I/O devices. By default, +\fBmdb\fR does not allow such access because many devices do not provide +hardware protection against invalid software manipulations. Use this option +only when debugging device drivers and with caution. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB-y\fR\fR +.ad +.RS 15n +.rt +Sends explicit terminal initialization sequences for tty mode. Some terminals, +such as \fBcmdtool\fR(1), require explicit initialization sequences to switch +into a tty mode. Without this initialization sequence, terminal features such +as standout mode can not be available to \fBmdb\fR. +.RE + +.SH OPERANDS +.sp +.LP +The following operands are supported: +.sp +.ne 2 +.mk +.na +\fB\fIobject\fR\fR +.ad +.RS 10n +.rt +Specifies an \fBELF\fR format object file to examine. \fBmdb\fR provides the +ability to examine and edit \fBELF\fR format executables (\fBET_EXEC\fR), +\fBELF\fR dynamic library files (\fBET_DYN\fR), \fBELF\fR relocatable object +files (\fBET_REL\fR), and operating system unix.X symbol table files. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIcore\fR\fR +.ad +.RS 10n +.rt +Specifies an \fBELF\fR process core file (\fBET_CORE\fR), or an operating +system crash dump vmcore.X file. If an \fBELF\fR core file operand is provided +without a corresponding object file, \fBmdb\fR attempts to infer the name of +the executable file that produced the core using several different algorithms. +If no executable is found, \fBmdb\fR still executes, but some symbol +information can be unavailable. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fIsuffix\fR\fR +.ad +.RS 10n +.rt +Specifies the numerical suffix representing a pair of operating system crash +dump files. For example, if the suffix is '\fB3\fR', \fBmdb\fR infers that it +should examine the files '\fBunix.3\fR' and '\fBvmcore.3\fR'. The string of +digits are not interpreted as a suffix if an actual file of the same name is +present in the current directory. +.RE + +.SH USAGE +.sp +.LP +\fBmdb\fR processes all input files (including scripts, object files, core +files, and raw data files) in a large file aware fashion. See +\fBlargefile\fR(5) for more information about the processing of large files, +which are files greater than or equal to 2 Gbytes (2^31 bytes). +.SH EXIT STATUS +.sp +.LP +The following exit values are returned: +.sp +.ne 2 +.mk +.na +\fB\fB0\fR\fR +.ad +.RS 5n +.rt +Debugger completed execution successfully. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB1\fR\fR +.ad +.RS 5n +.rt +A fatal error occurred. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB2\fR\fR +.ad +.RS 5n +.rt +Invalid command line options were specified. +.RE + +.SH ENVIRONMENT VARIABLES +.sp +.ne 2 +.mk +.na +\fB\fBHISTSIZE\fR\fR +.ad +.RS 12n +.rt +This variable is used to determine the maximum length of the command history +list. If this variable is not present, the default length is \fB128\fR. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBHOME\fR\fR +.ad +.RS 12n +.rt +This variable is used to determine the pathname of the user's home directory, +where a \fB\&.mdbrc\fR file can reside. If this variable is not present, no +\fB\&.mdbrc\fR processing occurs. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fBSHELL\fR\fR +.ad +.RS 12n +.rt +This variable is used to determine the pathname of the shell used to process +shell escapes requested using the \fB!\fR meta-character. If this variable is +not present, \fB/bin/sh\fR is used. +.RE + +.SH FILES +.sp +.ne 2 +.mk +.na +\fB\fB$HOME/.mdbrc\fR\fR +.ad +.sp .6 +.RS 4n +User \fBmdb\fR initialization file. The \fB\&.mdbrc\fR file, if present, is +processed after the debug target has been initialized, but before module +auto-loading is performed or any commands have been read from standard input. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB/dev/kmem\fR\fR +.ad +.sp .6 +.RS 4n +Kernel virtual memory image device. This device special file is used as the +core file when examining the live operating system. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB/dev/ksyms\fR\fR +.ad +.sp .6 +.RS 4n +Kernel symbol table device. This device special file is used as the object file +when examining the live operating system. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB/proc/\fIpid\fR/*\fR\fR +.ad +.sp .6 +.RS 4n +Process information files that are read when examining and controlling user +processes. +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB/usr/lib/adb\fR\fR +.ad +.br +.na +\fB\fB/usr/platform/\fIplatform-name\fR/lib/adb\fR\fR +.ad +.sp .6 +.RS 4n +Default directories for macro files that are read with the \fB$<\fR and +\fB$<<\fR dcmds. \fIplatform-name\fR is the name of the platform, derived +either from information in a core file or crash dump, or from the current +machine as if by \fBuname\fR \fB-i\fR (see \fBuname\fR(1)). +.RE + +.sp +.ne 2 +.mk +.na +\fB\fB/usr/lib/mdb\fR\fR +.ad +.br +.na +\fB\fB/usr/platform/\fIplatform-name\fR/lib/mdb\fR\fR +.ad +.sp .6 +.RS 4n +Default directories for debugger modules that are loaded using the \fB::load\fR +dcmd. \fIplatform-name\fR is the name of the platform, derived either from +information in a core file or crash dump, or from the current machine as if by +\fBuname\fR \fB-i\fR (see \fBuname\fR(1)). +.RE + +.SH ATTRIBUTES +.sp +.LP +See \fBattributes\fR(5) for descriptions of the following attributes: +.sp + +.sp +.TS +tab() box; +cw(2.75i) |cw(2.75i) +lw(2.75i) |lw(2.75i) +. +ATTRIBUTE TYPEATTRIBUTE VALUE +_ +Interface StabilityEvolving +.TE + +.SH SEE ALSO +.sp +.LP +\fBadb\fR(1), \fBcmdtool\fR(1), \fBgcore\fR(1), \fBproc\fR(1), \fBpgrep\fR(1), +\fBps\fR(1), \fBstty\fR(1), \fBtruss\fR(1), \fBuname\fR(1), \fBcoreadm\fR(1M), +\fBdumpadm\fR(1M), \fBlargefile\fR(5), \fBsavecore\fR(1M), \fBexec\fR(2), +\fBfork\fR(2), \fB_lwp_self\fR(2), \fBpipe\fR(2), \fBvfork\fR(2), +\fBdlopen\fR(3C), \fBelf\fR(3ELF), \fBlibc_db\fR(3LIB), \fBlibkvm\fR(3LIB), +\fBlibthread\fR(3LIB), \fBsignal\fR(3C), \fBsignal.h\fR(3HEAD), +\fBthr_self\fR(3C), \fBcore\fR(4), \fBproc\fR(4), \fBattributes\fR(5), +\fBlargefile\fR(5), \fBthreads\fR(5), \fBksyms\fR(7D), \fBmem\fR(7D) +.sp +.LP +\fILinker and Libraries Guide\fR +.sp +.LP +\fISolaris Modular Debugger Guide\fR +.SH WARNINGS +.SS "Use of the Error Recovery Mechanism" +.sp +.LP +The debugger and its dmods execute in the same address space, and thus it is +quite possible that a buggy dmod can cause \fBmdb\fR to dump core or otherwise +misbehave. The \fBmdb\fR resume capability, described above under \fBSignal +Handling\fR, provides a limited recovery mechanism for these situations. +However, it is not possible for \fBmdb\fR to know definitively whether the dmod +in question has corrupted only its own state, or the debugger's global state. +Therefore a resume operation cannot be guaranteed to be safe, or to prevent a +subsequent crash of the debugger. The safest course of action following a +resume is to save any important debug information, and then quit and restart +the debugger. +.SS "Use of the Debugger to Modify the Live Operating System" +.sp +.LP +The use of the debugger to modify (that is, write to) the address space of live +running operating system is extremely dangerous, and can result in a system +panic in the event the user damages a kernel data structure. +.SH NOTES +.SS "Limitations on Examining Process Core Files" +.sp +.LP +\fBmdb\fR does not provide support for examining process core files that were +generated by a release of Solaris preceding Solaris 2.6. When debugging core +files generated by a release of Solaris 9 or an earlier release, symbol +information might not be available. Since the text section and read-only data +is not present in those core files, the symbol information might not match the +data present in the process at the time it dumped core. In releases later than +Solaris 9, text sections and read-only data are included in core files by +default. Users can configure their processes to exclude that information from +core files using \fBcoreadm\fR(1M). Thus, the information presented by +\fBmdb\fR for those core files can not match the data that was present at the +time the process dumped core. Core files from Solaris x86 systems can not be +examined on Solaris SPARC systems, and vice-versa. +.SS "Limitations on Examining Crash Dump Files" +.sp +.LP +Crash dumps from Solaris 7 and earlier releases can only be examined with the +aid of the libkvm from the corresponding operating system release. If a crash +dump from one operating system release is examined using the dmods from a +different operating system release, changes in the kernel implementation can +prevent some dcmds or walkers from working properly. \fBmdb\fR issues a warning +message if it detects this condition. Crash dumps from Solaris x86 systems can +not be examined on Solaris SPARC systems, and vice-versa. +.SS "Relationship Between 32-bit and 64-bit Debugger" +.sp +.LP +\fBmdb\fR provides support for debugging both 32-bit and 64-bit programs. Once +it has examined the target and determined its data model, \fBmdb\fR +automatically re-executes the \fBmdb\fR binary that has the same data model as +the target, if necessary. This approach simplifies the task of writing debugger +modules, because the modules that are loaded use the same data model as the +primary target. Only the 64-bit debugger can be used to debug 64-bit target +programs. The 64-bit debugger can only be used on a system that is running the +64-bit operating environment. +.sp +.LP +The debugger can also need to re-execute itself when debugging a 32-bit process +that execs a 64-bit process, or vice-versa. The handling of this situation is +discussed in more detail under \fBInteraction with Exec\fR, below. +.SS "Interaction with Exec" +.sp +.LP +When a controlled process performs a successful \fBexec\fR(2), the behavior of +the debugger is controlled by the \fB::set\fR \fB-o\fR \fBfollow_exec_mode\fR +option, as described above. If the debugger and victim process have the same +data model, then the "\fBstop\fR" and "\fBfollow\fR" modes determine whether +\fBmdb\fR automatically continues the target or returns to the debugger prompt +following the exec. If the debugger and victim process have a different data +model, then the "\fBfollow\fR" behavior causes \fBmdb\fR to automatically +re-exec the \fBmdb\fR binary with the appropriate data model and to re-attach +to the process, still stopped on return from the exec. Not all debugger state +is preserved across this re-exec. +.sp +.LP +If a 32-bit victim process execs a 64-bit program, then "\fBstop\fR" returns to +the command prompt, but the debugger is no longer able to examine the process +because it is now using the 64-bit data model. To resume debugging, execute the +\fB::release\fR \fB-a\fR dcmd, quit \fBmdb\fR, and then execute \fBmdb\fR +\fB-p\fR \fIpid\fR to re-attach the 64-bit debugger to the process. +.sp +.LP +If a 64-bit victim process execs a 32-bit program, then "\fBstop\fR" returns to +the command prompt, but the debugger only provides limited capabilities for +examining the new process. All built-in dcmds work as advertised, but loadable +dcmds do not since they do not perform data model conversion of structures. The +user should release and re-attach the debugger to the process as described +above in order to restore full debugging capabilities. +.SS "Interaction with Job Control" +.sp +.LP +If the debugger is attached to a process that is stopped by job control (that +is, it stopped in response to \fBSIGTSTP\fR, \fBSIGTTIN\fR, or \fBSIGTTOU\fR), +the process can not be able to be set running again when it is continued by a +continue dcmd. If the victim process is a member of the same session (that is, +it shares the same controlling terminal as \fBmdb\fR), \fBmdb\fR attempts to +bring the associated process group to the foreground and to continue the +process with \fBSIGCONT\fR to resume it from job control stop. When \fBmdb\fR +is detached from such a process, it restores the process group to the +background before exiting. If the victim process is not a member of the same +session, \fBmdb\fR cannot safely bring the process group to the foreground, so +it continues the process with respect to the debugger, but the process remains +stopped by job control. \fBmdb\fR prints a warning in this case, and the user +must issue an "\fBfg\fR" command from the appropriate shell in order to resume +the process. +.SS "Process Attach and Release" +.sp +.LP +When \fBmdb\fR attaches to a running process, the process is stopped and +remains stopped until one of the continue dcmds is applied, or the debugger +quits. If the \fB-o\fR \fBnostop\fR option is enabled prior to attaching the +debugger to a process with \fB-p\fR, or prior to issuing an \fB::attach\fR or +\fB:A\fR command, \fBmdb\fR attaches to the process but does not stop it. While +the process is still running, it can be inspected as usual (albeit with +inconsistent results) and breakpoints or other tracing flags might be enabled. +If the \fB:c\fR or \fB::cont\fR dcmds are executed while the process is +running, the debugger waits for the process to stop. If no traced software +events occur, the user can send an interrupt (\fB^C\fR) after \fB:c\fR or +\fB::cont\fR to force the process to stop and return control to the debugger. +.sp +.LP +\fBmdb\fR releases the current running process (if any) when the \fB:R\fR, +\fB::release\fR, \fB:r\fR, \fB::run\fR, \fB$q\fR, or \fB::quit\fR dcmds are +executed, or when the debugger terminates as the result of an \fBEOF\fR or +signal. If the process was originally created by the debugger using \fB:r\fR or +\fB::run\fR, it is forcibly terminated as if by \fBSIGKILL\fR when it is +released. If the process was already running prior to attaching \fBmdb\fR to +it, it is set running again when it is released. A process can be released and +left stopped and abandoned using the \fB::release\fR \fB-a\fR option. +.SS "Symbolic Debugging Information" +.sp +.LP +The \fB::list\fR, \fB::offsetof\fR, \fB::print\fR, and \fB::sizeof\fR dcmds +require that one or more load objects contain compressed symbolic debugging +information suitable for use with \fBmdb\fR. This information is currently only +available for certain Solaris kernel modules. +.SS "Developer Information" +.sp +.LP +The \fISolaris Modular Debugger Guide\fR provides a more detailed description +of \fBmdb\fR features, as well as information for debugger module developers. +.sp +.LP +The header file \fB<sys/mdb_modapi.h>\fR contains prototypes for the functions +in the MDB Module \fBAPI\fR, and the SUNWmdbdm package provides source code for +an example module in the directory \fB/usr/demo/mdb\fR. |