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kdbx(8) System Manager's Manual kdbx(8) NAME kdbx - Analyzes running kernels and dump files. SYNOPSIS /usr/bin/kdbx [ -dbx dbx-path ] -k [ dbx-flags ] object-file [ core- file ] DESCRIPTION The kdbx debugger is a crash analysis and kernel debugging tool; it is an interactive program that serves as a front-end to the dbx debugger. The kdbx debugger is extensible, customizable, and insensitive to changes of offsets and sizes of fields in structures. The only depen- dencies on kernel header files are for bit definitions in flag fields. The kdbx debugger lets you examine either the running kernel or dump files created by the savecore command. In either case, you examine an object file and a core file. For running systems, these files are usu- ally /vmunix and /dev/mem, respectively. Dump files created by savecore are saved in the directory specified by the /sbin/init.d/savecore script. By default, the directory is /var/adm/crash. The kdbx debugger has facilities for interpreting various symbols and data structures. It can format and display the symbols and data struc- tures in the following ways: In a predefined form as specified in the modules that currently accompany the kdbx debugger As defined in user- written source code modules according to a standardized format for the contents of the kdbx modules All dbx commands are available through kdbx using the dbx flag to kdbx. Defaults If you do not specify a core file, kdbx uses the dbx default of /dev/mem. Therefore, you can use kdbx with /vmunix as its only argu- ment to examine an active system. In general, kdbx assumes that ad- dresses are specified in hexadecimal in commands that perform input or output. When you begin a debugging session, kdbx executes the commands in the system initialization file /var/kdbx/SYSTEM.kdbxrc. The initialization file contains setup commands and alias definitions. The Aliases sec- tion lists the aliases defined in this file. You can further customize the kdbx environment by adding commands and aliases to one of the fol- lowing initialization files: /var/kdbx/SITE.kdbxrc Contains customized commands and alias definitions for a partic- ular system. ~/.kdbxrc Contains customized commands and alias definitions for a spe- cific user. ./.kdbxrc Contains customized commands and alias definitions for a spe- cific project. This file must reside in the current working di- rectory when kdbx is invoked. Invocation To use kdbx to examine a running system, issue the following kdbx com- mand: # kdbx -k /vmunix /dev/mem dbx version 3.11.1 Type 'help' for help. stopped at [thread_block:1403 ,0xfffffc000032e3c0] Source not available (kdbx) To use kdbx to examine an object file and core file created by the savecore utility, issue a kdbx command like the following one: # kdbx -k /usr/adm/crash/vmunix.1 /usr/adm/crash/dev/vmcore.1 dbx ver- sion 3.11.1 Type 'help' for help. stopped at [thread_block:1403 ,0xfffffc000032e3c0] Source not available (kdbx) In this case, the version number in the bounds file is one. Commands The kdbx debugger provides the following commands: alias [ name ] [ command-string ] Sets or displays aliases. If you specify the alias command without arguments, kdbx displays all aliases. If you specify only the variable name, the command displays the alias for name, if one exists. If you specify both name and command-string, name is established as an alias for command-string. context proc | user Sets the context to user's aliases or extension's aliases. This command is used only by extensions. coredata start-address end-address Dumps, in hexadecimal, the contents of the core file starting at start-address and ending before end-address. dbx command-string Passes the variable command-string to dbx. Specifying dbx is optional; if the command is not recognized by kdbx, it is passed to dbx automatically. See the dbx(1) reference page for a com- plete description of the dbx commands. help [ -long ] [ arg ... ] Displays help text. proc [ flags ] [ extension ] [ arg ... ] Executes an extension and gives it control of the kdbx session until it quits. The variable extension specifies the named ex- tension file and passes it arguments as specified by the arg variables. Valid proc flags are as follows: -debug Causes I/O to and from the extension to be displayed on the screen. -pipe in-pipe out-pipe Used in conjunction with the dbx debugger for debugging exten- sions. The file in-pipe takes output from the dbx session and directs it as input to the kdbx session. The file out-pipe takes output from the kdbx session and directs it as input to the dbx session. -print_output Causes the output of the procedure to be sent to the invoker of the procedure without interpretation as kdbx commands. -redirect_output Used by extensions that execute other extensions to receive the output from the called extension instead of the user receiving it. -tty Causes kdbx to talk to the subprocess through a tty line instead of pipes. If you also specify the -pipe flag, proc ignores it. print string Displays string on the terminal. If this command is used by an extension, the extension receives no output. quit Exits the current command loop. If the current command loop is the top level loop that the user is using, kdbx exits. Other- wise, control is given to the next lowest loop. source [ -x ] [ files ] Reads and interprets files as kdbx commands in the context of the current aliases. The -x flag causes commands to be dis- played as they are executed. unalias name Removes an alias, if any, from name. Predefined kdbx Aliases The following aliases are defined in the kdbx startup file /var/kdbx/system.kdbxrc: tab(@); lfB lfB l l . _ Alias@Definition _ arp@"proc" arp array_action@"proc" array_action buf@"proc" buf buf_action@list_action "struct buf *" b_forw buf buf callout_action@list_action "struct callout *" c_next 0 callout cast@"proc" cast convert@"proc" convert config@"proc" config dis@"proc" dis echo@"proc" echo export@"proc" export fields@"proc" fields file@"proc" file h@help inpcb_action@list_action "struct inpcb *" inp_next list_action@"proc" list_action mount_action@list_action "struct mount *" m_next rootfs rootfs mount@"proc" mount name- cache@"proc" namecache ofile@"proc" ofile paddr@"proc" paddr pcb@"proc" pcb pr@"proc" printf@"proc" printf proc@"proc" proc procaddr@"proc" procaddr procp@"proc" -pipe /tmp/pipein /tmp/pipeout procpd@"proc" -de- bug -pipe /tmp/pipein /tmp/pipeout proc_action@list_action "struct proc *" p_nxt 0 allproc ps@"dbx" kps sh@"proc" -print_output -tty socket@"proc" socket sum@"proc" sum swap@"proc" swap task@"proc" task thread@"proc" thread u@"proc" u ucred@"proc" ucred unaliasall@"proc" unaliasall vnode@"proc" vnode _ Extensions For extensions that display addresses as part of their output, some use a shorthand notation for the upper 32-bits of an address to keep the output readable. The following table lists the notation for each ad- dress type. tab(@); lfB lfB lfB lfB lfCW lw(1.5i) lfCW lfCW. _ Notation@Address Type@Replaces@Example _ v@virtual@ffffffff@v0x902416f0 k@kseg@fffffc00@k0x363076f4 u@user space@00000000@u0x86406200 ?@T{ Unrecognized or random type T}@@?0x0033aa24 _ The extensions available to kdbx are as follows: arp [ - ] Displays the contents of the address resolution protocol (arp) table. If you specify the optional hyphen (-), arp displays the entire arp table; otherwise, arp displays those entries that have nonzero at_iaddr.s_addr and at_flags fields. array_action "type" length start_address [ flags ] command Performs a command action on each element of an array. This ex- tension allows you to step through any array in the operating system kernel and display specific components or values as de- scribed in the list of command flags. The arguments to the ar- ray_action extension are as follows: "type" The type of address of the array element. length The number of elements in the array. start_address The address of the array. A variable name or a number can be used to specify start_address. The more common syntax or nota- tion used to refer to the start_address is usually of the form &arrayname[0]. flags Valid flags for the array_action extension are as follows: -head If you specify the -head flag, kdbx displays the next argument as the table header. -size If you specify the -size flag, kdbx uses the next argument as the array element size. Otherwise, kdbx calculates the size from the element type. -cond If you specify the -cond flag, kdbx uses the next argument as a filter. The dbx debugger evaluates the condition for each array element, and if it evaluates to TRUE, takes the action on the array element. The same substitutions that are applied to the command are applied to the condition. command The name of the kdbx or dbx command that is to be performed on each element of the array. Note that the kdbx debugger includes several aliases, such as file_action, that might be easier to use than directly using the array_action extension. Substitutions similar to printf can be performed on the command for each array element. The possible substitutions are as fol- lows: tab(@); lfCW l. %a@Address of element %c@Cast of address to pointer to array element %i@Index of element within the array %s@Size of element %t@Type of pointer to element buf [ address | -free | -all ] Displays the buffer table. If no arguments are specified, the buffers on the hash list are displayed. If addresses are specified, the buffers at those addresses are displayed. If you specify the -free flag, kdbx displays all the buffers on the free list. If you specify the -all flag, kdbx displays buffers on the hash list first, followed by buffers on the free list. callout Displays the callout table. cast address type Forces dbx to display a piece of memory as a given type. This extension is equivalent to dbx print *((type)address). config Displays the configuration of the machine. convert [ -in 8 | 10 | 16 ] -out 2 | 8 | 10 | 16 [ args ] Converts numbers from one base to another. The -in and -out flags specify the input and output bases, respectively. If you omit -in, kdbx infers the input base from the arguments. The ar- guments can be either numbers or variables. cpustat [ -update n ] Displays CPU use statistics on a per-CPU basis. If you specify -update, kdbx updates the display every n seconds. dis start-address [ num-instructions ] Disassembles some number of instructions as specified in the num-instructions instructions starting at start-address. If you omit the number of instructions, kdbx disassembles one instruc- tion. export Displays the exported entries that are mounted remotely. file [ addresses ] Displays the file table. If no addresses are specified, all file entries with nonzero reference counts are displayed. Oth- erwise, the file entries at the specified addresses are dis- played. inpcb [ -udp ] [ -tcp ] [ addresses ] Displays the udb and tcb tables. If no arguments are specified, both tables are displayed. If you specify either -udp or -tcp, kdbx displays the corresponding table. If addresses are specified, -udp and -tcp are ignored and the entries at the specified addresses are displayed. list_action type next-field end-addr start-addr [ flags ] command Performs some command on each element of a linked list. This extension makes it possible to walk through any linked list in the operating system kernel and display particular components while walking through the linked list. The arguments to the list_action extension are as follows: "type" The type of address of an element in the specified list. next-field The name of the field that points to the next element. end-addr The value of the next field that terminates the list. If the list is NULL-terminated, the value of end-addr is 0. If the list is circular, the value of end-addr is equal to start-addr. start_address The address of a list. The address can be specified as a vari- able name or a number. flags Valid flags for the list_action extension are as follows: -head header If you specify the -head header flag, kdbx displays the header argument as the table header. -cond If you specify -cond, the next arg is used as a filter. The dbx debugger evaluates the condition for each list element, and if it evaluates to true, takes the action on the list element. The same substitutions that are applied to the command are applied to the condition. command The kdbx or dbx command to perform on each element of the list. Note that kdbx includes several aliases, such as file_action, that might be easier to use than directly using the list_action extension. Substitutions similar to printf substitutions are performed on the command for each element. The possible substitutions are as follows: tab(@); lfCW l. %a@Address of element %c@Cast of address to pointer to list element %i@Index of element within the list %n@Name of next field %t@Type of pointer to element lockinfo [-class name] Displays the static lock type information contained in the lock- info structures. This extension is available only when the lockmode system attribute is set to four. The -class flag al- lows you to display information about a particular class of locks. lockstats [-class name -cpu number -read -sum -total -update n] Displays statistics about locks recorded in the lockstats struc- ture. These statistics are dynamic. This extension is available only when the lockmode system attribute is set to four. Statistics displayed include information about the number of in- stances of a particular lock type, the number of times processes tried to get a lock type, the number of times processes tried and failed to get a particular lock type and the amount of time spent waiting for locks. The flags for the lockstats extension are as follows: -class name Displays the lockstats structures of the specified lock type -cpu number Displays the lockstats structures associated with the specified CPU -read Displays the reads, sleeps attributes, and summary of time spent waiting or number of misses -sum Displays summary data for all CPUs and all lock types -total Displays summary data for all CPUs -update n Updates the display every n seconds mount [ -s ] [ address ] Displays the mount table. The -s flag outputs a short form of the table. If addresses are specified, the mount entries at the specified addresses are displayed. namecache Displays the namecache structures on the system. ofile [ -proc address | -pid pid | -v ] Displays the files opened by processes. If no arguments are specified, the extension displays the files opened by each process. If you specify either -proc address or -pid pid, kdbx displays the open files of the given process. The -v flag dis- plays more information about the open files. paddr address number-of-longwords Converts a range of memory to symbolic references. The argument address is the starting address. The argument number-of-long- words is the number of words to dump out. pcb thread_address Displays the process control block for a given thread at the specified address. For integer and floating-point registers, only nonzero contents are displayed. printf format-string [ args ] Formats one argument at a time to work around the dbx debugger's command length limitation. It also implements the %s string sub- stitution, which the dbx printf command does not. The argument format-string specifies a character string combining literal characters with conversion specifications. proc [ addresses ] Displays the process table. If addresses are specified, the proc structures at the specified addresses are displayed. Oth- erwise, all proc structures are displayed. procaddr [ address ] Converts the specified address to a procedure name. socket Displays the files that are sockets with nonzero reference counts in the file table. sum Displays a summary of the system. swap Displays a summary of swap space. task [ proc_addresses ] Displays the task structures associated with the specified ad- dresses. If no addresses are specified, all tasks are dis- played. thread [ proc_addresses ] Displays information about the threads associated with the spec- ified addresses. If no addresses are specified, all threads are displayed. trace [ thread_address... | -k | -u | -a ] Displays the stack trace of one or more threads. If you specify thread_address, the extension displays the stack trace of the specified thread. If you omit the argument and all the flags, trace displays the stack trace of all threads. You can specify the following flags: -a Display the stack trace of the active thread on each CPU. -k Display the stack trace of all kernel threads. -u Display the stack trace of all user threads. -buf Display all ucred structures referenced by the buf structures. -ref address Display all references to a given ucred structure. -check address Check the reference count of a particular ucred structure. -checkall Check the reference count of all ucred structures (mismatch marked by *). u [ proc_address ] Displays a u structure at the address proc-addr. ucred [ -proc | -uthread | -file | -buf | -ref address \ | -check address | -checkall ] Displays or checks references to ucred structures. If no flags are specified, this extension displays all references to ucred structures on the system. Possible flags are as follows: -proc Display all ucred structures referenced by the proc structures. -uthread Display all ucred structures referenced by the uthread struc- tures. -file Display all ucred structures referenced by the file structures. -buf Display all ucred structures referenced by the buf structures. -ref address Display all references to a given ucred structure. -check address Check the reference count of a particular ucred structure. -checkall Check the reference count of all ucred structures (mismatch marked by *). unaliasall Removes all aliases including the predefined aliases described in the Predefined Aliases section. vnode [ -free | -all | -ufs | -nfs | -cdfs | -fs address | \ -u uid | -g gid | -v ] Displays the vnode table. If no arguments are specified, all AC- TIVE vnodes on the system are displayed. ACTIVE means nonzero usecount or nonzero holdcnt. Possible flags are listed as fol- lows: -free Display INACTIVE (both usecount and holdcnt are zeros) entries in the vnode table. -all Display ALL (both ACTIVE and INACTIVE) entries in the vnode ta- ble. -ufs Display all UFS vnodes. -nfs Display all NFS vnodes. -cdfs Display all CDFS vnodes. -fs address Display vnode entries of a mounted file system. -u uid Display vnode entries of a particular user. -g gid Display vnode entries of a particular group. -v Display related inode/rnode/cdnode information (used with -ufs, -nfs, or -cdfs only). RELATED INFORMATION Commands: dbx(1), savecore(8) Manuals: Kernel Debugging, Programmer's Guide delim off kdbx(8)