Subject: kern/775: DDB manpage is nonexistant
To: None <gnats-admin@NetBSD.ORG>
From: None <jhawk@MIT.EDU>
List: netbsd-bugs
Date: 02/02/1995 00:20:04
>Number: 775
>Category: kern
>Synopsis: DDB manpage is nonexistant
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: kern-bug-people (Kernel Bug People)
>State: open
>Class: doc-bug
>Submitter-Id: net
>Arrival-Date: Thu Feb 2 00:20:03 1995
>Originator: John Hawkinson
>Organization:
MIT: SIPB
>Release: 1.0
>Environment:
System: NetBSD lola-granola 1.0 NetBSD 1.0 (ATHENA-AHA) #4: Sat Jan 21 12:12:54 EST 1995 ghudson@glacier:/usr/src/sys/arch/i386/compile/ATHENA-AHA i386
>Description:
A manpage for DDB is not included with NetBSD.
>How-To-Repeat:
Ask Mark Eichin, <eichin@cygnus.com>, to port it from Mach
again.
>Fix:
Attached is what is presumably the current version of the Mach
ddb manpage. It certainly fails wrt expansion of the TLA,
but otherwise seems to be reasonably accurate. Of course,
it still uses old-style (-man) macros; thanks to Mark for
digging this up...
This version was found in:
/afs/cs.cmu.edu/project/mach/public/src/mkernel/src/kernel/man/ddb.2
*** /dev/null Thu Feb 2 02:01:42 1995
--- ddb.2 Thu Feb 2 01:44:47 1995
***************
*** 0 ****
--- 1,575 ----
+ .\"
+ .\" Mach Operating System
+ .\" Copyright (c) 1991,1990 Carnegie Mellon University
+ .\" All Rights Reserved.
+ .\"
+ .\" Permission to use, copy, modify and distribute this software and its
+ .\" documentation is hereby granted, provided that both the copyright
+ .\" notice and this permission notice appear in all copies of the
+ .\" software, derivative works or modified versions, and any portions
+ .\" thereof, and that both notices appear in supporting documentation.
+ .\"
+ .\" CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ .\" CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ .\" ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ .\"
+ .\" Carnegie Mellon requests users of this software to return to
+ .\"
+ .\" Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
+ .\" School of Computer Science
+ .\" Carnegie Mellon University
+ .\" Pittsburgh PA 15213-3890
+ .\"
+ .\" any improvements or extensions that they make and grant Carnegie Mellon
+ .\" the rights to redistribute these changes.
+ .\"
+ .\"
+ .\" HISTORY
+ .\" $Log: ddb.man,v $
+ .\" Revision 2.7 93/03/09 18:01:38 danner
+ .\" Added , modifier to examine
+ .\" [93/03/09 jfriedl]
+ .\"
+ .\" Revision 2.6 92/04/08 08:52:57 rpd
+ .\" Changes from OSF.
+ .\" [92/01/17 14:19:22 jsb]
+ .\" Changes for OSF debugger modifications.
+ .\" [91/12/12 tak]
+ .\"
+ .\" Revision 2.5 91/06/25 13:50:22 rpd
+ .\" Added some watchpoint explanation.
+ .\" [91/06/25 rpd]
+ .\"
+ .\" Revision 2.4 91/06/17 15:47:31 jsb
+ .\" Added documentation for continue/c, match, search, and watchpoints.
+ .\" I've not actually explained what a watchpoint is; maybe Rich can
+ .\" do that (hint, hint).
+ .\" [91/06/17 10:58:08 jsb]
+ .\"
+ .\" Revision 2.3 91/05/14 17:04:23 mrt
+ .\" Correcting copyright
+ .\"
+ .\" Revision 2.2 91/02/14 14:10:06 mrt
+ .\" Changed to new Mach copyright
+ .\" [91/02/12 18:10:12 mrt]
+ .\"
+ .\" Revision 2.2 90/08/30 14:23:15 dbg
+ .\" Created.
+ .\" [90/08/30 dbg]
+ .\"
+ .TH ddb 8
+ .SH NAME
+ ddb \- new kernel debugger
+ .de XX
+ .sp
+ .ti -4n
+ \\$1
+ .br
+ .sp
+ ..
+ .de XS
+ .nr )R +\\$1
+ ..
+ .de XE
+ .nr )R -\\$1
+ ..
+ .SH DESCRIPTION
+ .br
+ .sp
+ The new kernel debugger has most of the features of the old kdb,
+ but with a more rational (gdb-like) syntax.
+ .sp
+ The current location is called 'dot'. The 'dot' is displayed with
+ a hexadecimal format at a prompt.
+ Examine and write commands update 'dot' to the address of the last line
+ examined or the last location modified, and set 'next' to the address of
+ the next location to be examined or changed.
+ Other commands don't change 'dot', and set 'next' to be the same as 'dot'.
+ .sp
+ The general command syntax is:
+ .sp
+ .ti +4n
+ \fIcommand[/modifier] address [,count]\fR
+ .sp
+ "!!" repeats the previous command, and
+ a blank line repeats from the address 'next' with count 1 and no modifiers.
+ Specifying 'address' sets 'dot' to the address.
+ Omitting 'address' uses 'dot'.
+ A missing 'count' is taken to be 1 for printing commands or infinity
+ for stack traces.
+ .sp
+ Current
+ .B ddb
+ is enhanced to support multi-thread debugging. A break point can be
+ set only for a specific thread, and the address space or registers of
+ non current thread can be examined or modified if supported by machine
+ dependent routines.
+ For example,
+ .sp
+ .ti +4n
+ break/t mach_msg_trap $task11.0
+ .sp
+ sets a break point at "mach_msg_trap" for the first thread
+ of task 11 listed by a "show all threads" command.
+ .br
+ In the above example, "$task11.0" is translated to the corresponding
+ thread structure's address by variable translation mechanism described later.
+ If a default target thread is set in a variable "$thread", the "$task11.0"
+ can be omitted.
+ In general, if 't' is specified in a modifier of a command line,
+ a specified thread or a default target thread is used as a target thread
+ instead of the current one.
+ The 't' modifier in a command line is not valid in evaluating
+ expressions in a command line. If you want to get a value indirectly
+ from a specific thread's address space or access to its registers within
+ an expression, you have to specify a default target thread in advance,
+ and to use ":t" modifier immediately after the indirect access or the register
+ reference like as follows:
+ .sp
+ .ti +4n
+ set $thread $task11.0
+ .br
+ .ti +4n
+ print $eax:t *(0x100):tuh
+ .sp
+ No sign extension and indirection size(long, half word, byte)
+ can be specified with 'u', 'l', 'h' and 'b' respectively
+ for the indirect access.
+ .br
+ Note: Support of non current space/register access and user space
+ break point depend on the machines. If not supported, attempts of
+ such operation may provide incorrect information or may cause strange
+ behavior. Even if supported, the user space access is limited
+ to the pages resident in the main memory at that time. If a target
+ page is not in the main memory, an error will be reported.
+ .sp
+ "\fBddb\fR" has a feature like a command "\fBmore\fR"
+ for the output. If an output line exceeds the number set in the $lines
+ variable, it displays "\fI--db_more--\fR"
+ and waits for a response.
+ The valid responses for it are:
+ .XS 4n
+ .IP \fI\<space>\fR 10n
+ one more page
+ .IP \fI\<return>\fR 10n
+ one more line
+ .IP \fB\q\fR 10n
+ abort the current command, and return to the command input mode.
+ .LP
+ .sp
+ .XE 4n
+ .LP
+ .B COMMANDS
+ .sp
+ .XS 4n
+ .LP
+ .XX "\fBexamine(x) \fI[/<modifier>] <addr>[,<count>] [ <thread> ]\fR"
+ Display the addressed locations according to the formats in the modifier.
+ Multiple modifier formats display multiple locations.
+ If no format is specified, the last formats specified for this command
+ is used.
+ Address space other than that of the current thread can be specified
+ with 't' option in the modifier and 'thread' parameter.
+ .br
+ The format characters are
+ .sp
+ .LP
+ .XS 2n
+ .IP b 5n
+ look at by bytes(8 bits)
+ .IP h 5n
+ look at by half words(16 bits)
+ .IP l 5n
+ look at by long words(32 bits)
+ .IP a 5n
+ print the location being displayed
+ .IP , 5n
+ skip one unit producing no output
+ .IP A 5n
+ print the location with a line number if possible
+ .IP x 5n
+ display in unsigned hex
+ .IP z 5n
+ display in signed hex
+ .IP o 5n
+ display in unsigned octal
+ .IP d 5n
+ display in signed decimal
+ .IP u 5n
+ display in unsigned decimal
+ .IP r 5n
+ display in current radix, signed
+ .IP c 5n
+ display low 8 bits as a character.
+ Non-printing characters are displayed as an octal escape code (e.g. '\\000').
+ .IP s 5n
+ display the null-terminated string at the location.
+ Non-printing characters are displayed as octal escapes.
+ .IP m 5n
+ display in unsigned hex with character dump at the end of each line.
+ The location is also displayed in hex at the beginning of each line.
+ .IP i 5n
+ display as an instruction
+ .IP I 5n
+ display as an instruction with possible alternate formats depending on the
+ machine:
+ .XE 2n
+ .LP
+ .XS 5n
+ .LP
+ .IP vax 6n
+ don't assume that each external label is a procedure entry mask
+ .IP i386 6n
+ don't round to the next long word boundary
+ .IP mips 6n
+ print register contents
+ .LP
+ .XE 5n
+ .LP
+ .XX xf
+ Examine forward.
+ It executes an examine command with the last specified parameters to it
+ except that the next address displayed by it is used as the start address.
+ .XX xb
+ Examine backward.
+ It executes an examine command with the last specified parameters to it
+ except that the last start address subtracted by the size displayed by it
+ is used as the start address.
+ .XX "\fBprint[/axzodurc] \fI<addr1> [ <addr2> ... ]\fR"
+ Print 'addr's according to the modifier character.
+ Valid formats are: a x z o d u r c.
+ If no modifier is specified, the last one specified to it is used. 'addr'
+ can be a string, and it is printed as it is. For example,
+ .br
+ .sp
+ .ti +4n
+ print/x "eax = " $eax "\\necx = " $ecx "\\n"
+ .br
+ .sp
+ will print like
+ .sp
+ .in +4n
+ eax = xxxxxx
+ .br
+ ecx = yyyyyy
+ .in -4n
+ .sp
+ .br
+ .XX "\fBwrite[/bhlt] \fI<addr> [ <thread> ] <expr1> [ <expr2> ... ]\fR"
+ Write the expressions at succeeding locations.
+ The write unit size can be specified in the modifier with a letter
+ b (byte), h (half word) or l(long word) respectively. If omitted,
+ long word is assumed. Target address space can also be specified
+ with 't' option in the modifier and 'thread' parameter.
+ .br
+ Warning: since there is no delimiter between expressions, strange
+ things may happen.
+ It's best to enclose each expression in parentheses.
+ .XX "\fBset \fI$<variable> [=] <expr>\fR"
+ Set the named variable or register with the value of 'expr'.
+ Valid variable names are described below.
+ .XX "\fBbreak[/tuTU] \fI<addr>[,<count>] [ <thread1> ...]\fR"
+ Set a break point at 'addr'.
+ If count is supplied, continues (count-1) times before stopping at the
+ break point. If the break point is set, a break point number is
+ printed with '#'. This number can be used in deleting the break point
+ or adding conditions to it.
+ .LP
+ .XS 2n
+ .IP t 5n
+ Set a break point only for a specific thread. The thread is specified
+ by 'thread' parameter, or default one is used if the parameter is omitted.
+ .IP u 5n
+ Set a break point in user space address. It may be combined with 't' or 'T'
+ option to specify the non-current target user space. Without 'u' option,
+ the address is considered in the kernel space, and wrong space address
+ is rejected with an error message.
+ This option can be used only if it is supported by machine dependent
+ routines.
+ .IP T 5n
+ Set a break point only for threads in a specific task. It is like 't'
+ option except that the break point is valid for all threads which belong
+ to the same task as the specified target thread.
+ .IP U 5n
+ Set a break point in shared user space address. It is like 'u' option,
+ except that the break point is valid for all threads which share the
+ same address space even if 't' option is specified. 't' option is used
+ only to specify the target shared space. Without 't' option, 'u' and 'U'
+ have the same meanings. 'U' is useful for setting a user space
+ break point in non-current address space with 't' option such as in an
+ emulation library space.
+ This option can be used only if it is supported by machine dependent
+ routines.
+ .LP
+ .XE 2n
+ Warning: if a user text is shadowed by a normal user space debugger,
+ user space break points may not work correctly. Setting a break
+ point at the low-level code paths may also cause strange behavior.
+ .XX "\fBdelete[/tuTU] \fI<addr>|#<number> [ <thread1> ...]\fR"
+ Delete the break point. The target break point can be specified by a
+ break point number with '#', or by 'addr' like specified in 'break'
+ command.
+ .XX "\fBcond \fI#<number> [ <condition> <commands> ]\fR"
+ Set or delete a condition for the break point specified by the 'number'.
+ If the 'condition' and 'commands' are null, the condition is deleted.
+ Otherwise the condition is set for it.
+ When the break point is hit, the 'condition' is evaluated.
+ The 'commands' will be executed if the condition is true and the break
+ point count set by a break point command becomes zero. 'commands' is
+ a list of commands separated by semicolons.
+ Each command in the list is executed in that order, but if a "continue"
+ command is executed, the command execution stops there, and the stopped
+ thread resumes execution. If the command execution reaches the
+ end of the list, and it enters into a command input mode.
+ .br
+ For example,
+ .sp
+ .nf
+ set $work0 0
+ break/Tu xxx_start $task7.0
+ cond #1 (1) set $work0 1; set $work1 0; cont
+ break/T vm_fault $task7.0
+ cond #2 ($work0) set $work1 ($work1+1); cont
+ break/Tu xxx_end $task7.0
+ cond #3 ($work0) print $work1 " faults\\n"; set $work0 0
+ cont
+ .br
+ .fi
+ .sp
+ will print page fault counts from 'xxx_start' to 'xxx_end' in task7.
+ .br
+ .XX "\fBstep[/p] \fI[,<count>]\fR"
+ Single step 'count' times.
+ If 'p' option is specified, print each instruction at each step.
+ Otherwise, only print the last instruction.
+ .br
+ .sp
+ Warning: depending on machine type, it may not be possible to
+ single-step through some low-level code paths or user space code.
+ On machines with software-emulated single-stepping (e.g., pmax),
+ stepping through code executed by interrupt handlers will probably
+ do the wrong thing.
+ .XX "\fBcontinue[/c]\fR"
+ Continue execution until a breakpoint or watchpoint.
+ If /c, count instructions while executing.
+ Some machines (e.g., pmax) also count loads and stores.
+ .br
+ .sp
+ Warning: when counting, the debugger is really silently single-stepping.
+ This means that single-stepping on low-level code may cause strange
+ behavior.
+ .XX "\fBuntil\fR"
+ Stop at the next call or return instruction.
+ .XX "\fBnext[/p]\fR"
+ Stop at the matching return instruction.
+ If 'p' option is specified, print the call nesting depth and the
+ cumulative instruction count at each call or return. Otherwise,
+ only print when the matching return is hit.
+ .XX "\fBmatch[/p]\fR"
+ A synonym for 'next'.
+ .XX "\fBtrace[/tu] \fI[ <frame_addr>|<thread> ][,<count>]\fR"
+ Stack trace. 'u' option traces user space; if omitted, only traces
+ kernel space. If 't' option is specified, it shows the stack trace
+ of the specified thread or a default target thread.
+ Otherwise, it shows the stack trace of the current thread from the
+ frame address specified by a parameter or from the current frame. 'count'
+ is the number of frames to be traced. If the 'count' is omitted,
+ all frames are printed.
+ .br
+ .sp
+ Warning: If the target thread's stack is not in the main memory at that
+ time, the stack trace will fail. User space stack trace is valid
+ only if the machine dependent code supports it.
+ .XX "\fBsearch[/bhl] \fI<addr> <value> [<mask>] [,<count>]\fR"
+ Search memory for a value. This command might fail in interesting
+ ways if it doesn't find the searched-for value. This is because
+ ddb doesn't always recover from touching bad memory. The optional
+ count argument limits the search.
+ .XX "\fBmacro \fI<name> <commands>\fR"
+ Define a debugger macro as 'name'. 'commands' is a list of commands
+ to be associated with the macro.
+ In the expressions of the command list, a variable
+ .B $arg\fIxx\fR
+ can be used to get a parameter passed to the macro.
+ When a macro is called, each argument is evaluated as an expression,
+ and the value is assigned to each parameter,
+ .B $arg1, $arg2, ...
+ respectively. 10
+ .B $arg
+ variables are reserved to each level of macros, and they can be used
+ as local variables.
+ The nesting of macro can be allowed up to 5 levels.
+ .br
+ For example,
+ .sp
+ .nf
+ macro xinit set $work0 $arg1
+ macro xlist examine/m $work0,4; set $work0 *($work0)
+ xinit *(xxx_list)
+ xlist
+ ....
+ .sp
+ will print the contents of a list starting from 'xxx_list'
+ by each "xlist" command.
+ .fi
+ .XX "\fBdmacro \fI<name>\fR"
+ Delete the macro named 'name'.
+ .XX "\fBshow all threads[/ul]\fR"
+ Display all tasks and threads information.
+ This version of "\fBddb\fR"
+ prints more information than previous one.
+ It shows UNIX process information like "ps" for each task.
+ The UNIX process information may not be shown if it is not
+ supported in the machine, or the bottom of the stack of the
+ target task is not in the main memory at that time.
+ .br
+ It also shows task and thread identification numbers.
+ These numbers can be used to specify a task or a thread
+ symbolically in various commands.
+ The numbers are valid only in the same debugger session.
+ If the execution is resumed again, the numbers may change.
+ The current thread can be distinguished from others by a '#' after
+ the thread id instead of ':'.
+ .br
+ Without 'l' option, it only shows thread id, thread structure address
+ and the status for each thread. The status consists of 5 letters,
+ R(run), W(wait), S(suspended), O(swapped out) and N(interruptible),
+ and if corresponding status bit is off, '.' is printed instead.
+ If 'l' option is specified, more detail information is printed for each
+ thread.
+ .XX "\fBshow task \fI[ <addr> ]\fR"
+ Display the information of a task specified by 'addr'. If 'addr' is
+ omitted, current task information is displayed.
+ .XX "\fBshow thread \fI[ <addr> ]\fR"
+ Display the information of a thread specified by 'addr'. If 'addr' is
+ omitted, current thread information is displayed.
+ .XX "\fBshow registers[/tu \fI[ <thread> ]]\fR"
+ Display the register set.
+ Target thread can be specified with 't' option and 'thread' parameter.
+ If 'u' option is specified, it displays user registers instead of
+ kernel or currently saved one.
+ .br
+ .sp
+ Warning: The support of 't' and 'u' option depends on the machine. If
+ not supported, incorrect information will be displayed.
+ .XX "\fBshow map \fI<addr>\fR"
+ Prints the vm_map at 'addr'.
+ .XX "\fBshow object \fI<addr>\fR"
+ Prints the vm_object at 'addr'.
+ .XX "\fBshow page \fI<addr>\fR"
+ Prints the vm_page structure at 'addr'.
+ .XX "\fBshow port\fR"
+ Prints the ipc_port structure at 'addr'.
+ .XX "\fBshow ipc_port[/t \fI[ <thread> ]]\fR"
+ Prints all ipc_port structure's addresses the target thread has.
+ The target thread is a current thread or that specified by a parameter.
+ .XX "\fBshow macro \fI[ <name> ]\fR"
+ Show the definitions of macros.
+ If 'name' is specified, only the definition of it is displayed.
+ Otherwise, definitions of all macros are displayed.
+ .XX "\fBshow watches\fR"
+ Displays all watchpoints.
+ .XX "\fBwatch[/T] \fI<addr>,<size> [ <task> ]\fR"
+ Set a watchpoint for a region. Execution stops
+ when an attempt to modify the region occurs.
+ The 'size' argument defaults to 4.
+ .br
+ Without 'T' option, 'addr' is assumed to be a kernel address.
+ If you want to set a watch point in user space, specify 'T'
+ and 'task' parameter where the address belongs to. If the 'task'
+ parameter is omitted, a task of the default target thread or
+ a current task is assumed.
+ If you specify a wrong space address, the request is rejected
+ with an error message.
+ .br
+ .sp
+ Warning: Attempts to watch wired kernel memory
+ may cause unrecoverable error in some systems such as i386.
+ Watchpoints on user addresses work best.
+ .br
+ .LP
+ .XE 4n
+ .LP
+ .sp
+ .B VARIABLES
+ .sp
+ The debugger accesses registers and variables as
+ .I $<name>.
+ Register names are as in the "\fBshow registers\fR"
+ command.
+ Some variables are suffixed with numbers, and may have some modifier
+ following a colon immediately after the variable name.
+ For example, register variables can have 'u' and 't' modifier to indicate
+ user register and that of a default target thread instead of that of the
+ current thread (e.g. $eax:tu).
+ .br
+ .sp
+ Built-in variables currently supported are:
+ .sp
+ .IP task\fIxx[.yy]\fR 12n
+ Task or thread structure address. 'xx' and 'yy' are task and thread
+ identification numbers printed by a "\fBshow all threads\fR"
+ command respectively. This variable is read only.
+ .IP thread 12n
+ The default target thread. The value is used when 't' option is
+ specified without explicit thread structure address parameter
+ in command lines or expression evaluation.
+ .IP radix 12n
+ Input and output radix
+ .IP maxoff 12n
+ Addresses are printed as 'symbol'+offset unless offset is greater than maxoff.
+ .IP maxwidth 12n
+ The width of the displayed line.
+ .IP lines 12n
+ The number of lines. It is used by "more" feature.
+ .IP tabstops 12n
+ Tab stop width.
+ .IP arg\fIxx\fR
+ Parameters passed to a macro.
+ .I 'xx'
+ can be 1 to 10.
+ .IP work\fIxx\fR
+ Work variable.
+ .I 'xx'
+ can be 0 to 31.
+ .LP
+ .LP
+ .sp
+ .B EXPRESSIONS
+ .sp
+ Almost all expression operators in C are supported except '~', '^',
+ and unary '&'.
+ Special rules in "\fBddb\fR"
+ are:
+ .br
+ .IP "<identifier>" 15n
+ name of a symbol. It is translated to the address(or value) of it. '.'
+ and ':' can be used in the identifier. If supported by an object format
+ dependent routine,
+ [\fI<file_name>\fR:]\fI<func>\fR[:\fI<line_number>\fR]
+ [\fI<file_name>\fR:]\fI<variable>\fR, and
+ \fI<file_name>\fR[:\fI<line_number>\fR]
+ can be accepted as a symbol.
+ The symbol may be prefixed with '\fI<symbol_table_name>\fR::'
+ like 'emulator::mach_msg_trap' to specify other than kernel symbols.
+ .IP "<number>" 15n
+ radix is determined by the first two letters:
+ 0x: hex, 0o: octal, 0t: decimal, otherwise, follow current radix.
+ .IP \. 15n
+ \'dot'
+ .IP \+ 15n
+ \'next'
+ .IP \.. 15n
+ address of the start of the last line examined.
+ Unlike 'dot' or 'next', this is only changed by "examine" or
+ "write" command.
+ .IP \' 15n
+ last address explicitly specified.
+ .IP "$<variable>" 15n
+ register name or variable. It is translated to the value of it.
+ It may be followed by a ':' and modifiers as described above.
+ .IP \# 15n
+ a binary operator which rounds up the left hand side to the next
+ multiple of right hand side.
+ .IP "*<expr>" 15n
+ indirection. It may be followed by a ':' and modifiers as described above.
>Audit-Trail:
>Unformatted: