NAME

crash − examine system images

SYNOPSIS

/usr/sbin/crash [ −d dumpfile ] [ −n namelist ] [ −w ]

DESCRIPTION

The crash command is used to examine the system memory image of a running or a crashed system by formatting and printing control structures, tables, and other information.  Command line arguments to crash are dumpfile, namelist, and outputfile. 

dumpfile is the file containing the system memory image.  The default dumpfile is /dev/mem. 

The text file namelist contains the symbol table information needed for symbolic access to the system memory image to be examined.  The default namelist is the file used to boot the running system (e.g. /stand/unix).  If a system image from another machine is to be examined, the corresponding text file must be copied from that machine. 

When the crash command is invoked, a session is initiated.  The output from a crash session is directed to outputfile.  The default outputfile is the standard output. 

Input during a crash session is of the form:

function [ argument. . . ]

where function is one of the crash functions described in the “FUNCTIONS” subsection of this manual page, and arguments are qualifying data that indicate which items of the system image are to be printed. 

The default for process-related items is the current process for a running system or the process that was running at the time of the crash for a crashed system.  If the contents of a table are being dumped, the default is all active table entries. 

The following function options are available to crash functions wherever they are semantically valid. 

−e Display every entry in a table. 

−f Display the full structure. 

−L level Specify a level of detail for a particular command line; the larger the level, the more detail displayed.  Level begins at 1 and usually tops out at 3.  Larger values simply act as 3. 

−p Interpret all address arguments in the command line as physical addresses.  If they are not physical addresses, results are inconsistent. 

−s process Specify a process slot other than the default. 

−w file Redirect the output of a function to file. 

The functions mode, defproc, and redirect correspond to the function options −p, −s, and −w.  The mode function may be used to set the address translation mode to physical or virtual for all subsequently entered functions; defproc sets the value of the process slot argument for subsequent functions; and redirect redirects all subsequent output. 

Output from crash functions may be piped to another program in the following way:

function [ argument. . . ] ! shell_command

For example,

mount ! grep rw

writes all mount table entries with an rw flag to the standard output.  The redirection option (−w) cannot be used with this feature. 

Depending on the context of the function, numeric arguments are assumed to be in a specific radix.  Counts are assumed to be decimal.  Addresses are always hexadecimal.  Table address arguments larger than the size of the function table are interpreted as hexadecimal addresses; those smaller are assumed to be decimal slots in the table.  Default bases on all arguments may be overridden.  The C conventions for designating the bases of numbers are recognized.  A number that is usually interpreted as decimal is interpreted as hexadecimal if it is preceded by 0x and as octal if it is preceded by 0.  Decimal override is designated by 0d, and binary by 0b. 

Aliases for functions may be any uniquely identifiable initial substring of the function name.  Traditional aliases of one letter, such as p for proc, remain valid. 

Many functions accept different forms of entry for the same argument.  Requests for table information accept a table entry number, a physical address, a virtual address, a symbol, a range, or an expression.  A range of slot numbers may be specified in the form a−b where a and b are decimal numbers.  An expression consists of two operands and an operator.  An operand may be an address, a symbol, or a number; the operator may be +, −, ∗, /, &, or | .  An operand that is a number should be preceded by a radix prefix if it is not a decimal number (0 for octal, 0x for hexadecimal, 0b for binary).  The expression must be enclosed in parentheses.  Other functions accept any of these argument forms that are meaningful. 

Two abbreviated arguments to crash functions are used throughout.  Both accept data entered in several forms.  They may be expanded into the following:

table_entry = table entry | address | symbol | range | expression

start_addr = address | symbol | expression

FUNCTIONS

? [−w file]
List available functions.

!command
Escape to the shell and execute command.

as [−k] [−e] [−f] [−L lev] [−w file] [proc. . .]
Print information on process segments. Increasing levels given to -L provide increasing levels of detail regarding constituent segments, their global properties, and individual slot entries.  The −k flag displays the kernel’s address space structure, overriding the proc entry specification. 

base [−w file] number . . . 
Print number in binary, octal, decimal, and hexadecimal.  A number in a radix other than decimal should be preceded by a prefix that indicates its radix as follows: 0x, hexadecimal; 0, octal; and 0b, binary. 

buffer [−w file] [−format] [−p]buffer_addr
Alias: b. 
Print the contents of a buffer in the designated format. The following format designations are recognized: −b, byte: −c, character; −d, decimal; −x, hexadecimal; −o, octal; and, −i, inode.  If no format is given, the previous format is used.  The default format at the beginning of a crash session is hexadecimal. 

bufhdr [−f] [−w file] [[−p]hdr_addr. . .]
Alias: buf. 
Print system buffer headers. The −f option produces different output depending on whether the buffer is local or remote (contains RFS data). 

callout [−w file]
Alias: c. 
Print the callout table.

class [−w file] [table_entry. . .]
Print information about process scheduler classes.

dbfree  [−w file] [class . . . ]
Print free streams data block headers. If a class is entered, only data block headers for the class specified is printed.

dblock [−e] [−w file] [−c class. . .]

dblock [−e] [−w file] [[−p] table_entry. . .]
Print allocated streams data block headers. If the class option (−c) is used, only data block headers for the class specified is printed. 

defproc [−w file] [−c]

defproc [−w file] [slot]
Set the value of the process slot argument. The process slot argument may be set to the current slot number (−c) or the slot number may be specified.  If no argument is entered, the value of the previously set slot number is printed.  At the start of a crash session, the process slot is set to the current process. 

dis [−w file] [−a] start_addr [count]

dis [−w file] [−a] −c [count]
Disassemble count instructions starting at start_addr.  The default count is 1.  The absolute option (−a) specifies a non-symbolic disassembly.  The −c option can be used in place of start_addr to continue disassembly at the address at which a previous disassembly ended. 

dispq [−w file] [table_entry. . .]
Print the dispatcher (scheduler) queues.

ds [−w file] virtual_address . . . 
Print the data symbol whose address is closest to, but not greater than, the address entered.

file [−e] [−w file] [[−p]table_entry. . .]
Alias: f. 
Print the file table.

findaddr [−w file] table slot
Print the address of slot in table.  Only tables available to the size function are available to findaddr. 

findslot [−w file] virtual_address . . . 
Print the table, entry slot number, and offset for the address entered. Only tables available to the size function are available to findslot. 

fs [−w file] [[−p]table_entry. . .]
Print the file system information table.

gdp [−e] [−f] [−w file] [[−p]table_entry. . .]
Print the gift descriptor protocol table.

help [−w file] function . . . 
Print a description of the named function, including syntax and aliases.

inode [−e] [−f] [−L lev] [−w file] [[−p]table_entry. . .]
Alias: i. 
Print the inode table, including file system switch information. Higher levels show file blocks and then pages attached to the file.

kfp [−w file] [−s process] [−r]

kfp [−w file] [−s process] [value]
Print the kernel frame pointer (kfp) for the start of a kernel stack trace. The kfp value can be set using the value argument or the reset option (−r), which sets the kfp from the saved kfp in the dumpfile.  If no argument is entered, the current value of the kfp is printed. 

kmastat [−w file]
Print kernel memory allocator statistics.

lck [−e] [−w file] [[−p]table_entry. . .]
Alias: l. 
Print record locking information. If the −e option is used or table address arguments are given, the record lock list is printed.  If no argument is entered, information on locks relative to inodes is printed. 

linkblk [−e] [−w file] [[−p]table_entry. . .]
Print the linkblk table.

major [−w file] [entry . . .]
Print the MAJOR table.

map [−w file] mapname . . . 
Print the map structure of the given mapname.

mbfree [−w file]
Print free streams message block headers.

mblock [−e] [−w file] [[−p]table_entry. . .]
Print allocated streams message block headers.

mode [−w file] [mode]
Set address translation of arguments to virtual (v) or physical (p) mode.  If no mode argument is given, the current mode is printed.  At the start of a crash session, the mode is virtual. 

mount [−e] [−w file] [[−p]table_entry. . .]
Alias: m, vfs. 
Print information about mounted file systems.

nm [−w file] symbol . . . 
Print value and type for the given symbol.

nvram [−w file] user|0|net|1|os|3|bug|5|config|6|all|7
Print out the contents of non-volatile RAM. Using a numerical section identifier causes the values to be printed in hexadecimal byte and ascii formats. Using the section name causes the values to be printed in formatted form if a specific format is defined for that section of non-volatile RAM and in hexadecimal byte and ascii formats if no specific format has been defined. Currently, only the config section has a specific format.  The nvram command may not be available on all systems since some systems may not have any non-volatile RAM. 

od [−p] [−w file] [−format] [−mode] [−s process] start_addr [count]
Alias: rd. 
Print count values starting at start_addr in one of the following formats:  character (−c), decimal (−d), hexadecimal (−x), octal (−o), ASCII (−a), or hexadecimal/character (−h), and one of the following modes: long (−l), short (−t), or byte (−b).  The default mode for character and ASCII formats is byte; the default mode for decimal, hexadecimal, and octal formats is long.  The format −h prints both hexadecimal and character representations of the addresses dumped; no mode needs to be specified.  When format or mode is omitted, the previous value is used.  At the start of a crash session, the format is hexadecimal and the mode is long.  If no count is entered, 1 is assumed. 

page [-e] [-wfile] [[-p] table_entry . . .]
Print information about pages.

pcb [−w file] [process]
Print the process control block.  If no arguments are given, the active pcb for the current process is printed.  This applies to M88000 family of processors. 

prnode [−e] [−L lev] [−w file] [[−p] table_entry. . .]
Print information about the private data of processes being traced.

proc [−e] [−u] [−f] [−w file] [[−p] table_entry . . . #procid . . .]

proc [−u] [−f] [−w file] [−r]
Alias: p. 
Print the process table. Process table information may be specified in two ways. First, any mixture of table entries and process IDs may be entered.  Each process ID must be preceded by a #.  Alternatively, process table information for runnable processes may be specified with the runnable option (−r).  The -u option displays the address of the u-segment page tables. 

ptbl [−w file] [−sprocess] ste [count]

ptbl [−w file] [−sprocess]  [−p]  addr [count]
Print information on page descriptor tables, where ste is the segment table entry. 

pty [−f] [-e] [−w file] [−s] [−h] [−l]
Print the pseudo ttys presently configured. The −l, −s and −h options give information about the STREAMS modules ldterm, ptem and pckt, respectively. 

qrun [−w file]
Print the list of scheduled streams queues.

queue [−e] [−w file] [[−p]table_entry. . .]
Print streams queues.

quit Alias: q. 
Terminate the crash session. 

rcvd [−e] [−f] [−w file] [[−p]table_entry. . .]
Print the receive descriptor table.

rduser [−e] [−f] [−w file] [[−p]table_entry. . .]
Print the receive descriptor user table.

regs [−w file] [-g] [-s] [-m] [-f] [-a] 
Print Motorola M68000 or M88000 family of processors and co-processor registers including the general, supervisor, mmu, and floating point registers. The (−a) option prints all of the register groups. 

redirect [−w file] [−c]

redirect [−w file] [newfile]
Used with a file name, redirects output of a crash session to newfile.  If no argument is given, the file name to which output is being redirected is printed.  Alternatively, the close option (−c) closes the previously set file and redirects output to the standard output. 

resource [−e] [−w file] [[−p]table_entry. . .]
Print the advertise table.

rtdptbl [−w file] [table_entry. . .]
Print the real-time scheduler parameter table. See rt_dptbl(4). 

rtproc [−w file]
Print information about processes in the real-time scheduler class.

sdt [−e] [−w file] [−s process] [−p start_addr] [count]
The segment descriptor table for the named memory section is printed. Alternatively, the segment descriptor table starting at start_addr for count entries is printed.  If no count is given, a count of 1 is assumed. 

search [−p] [−w file] [−m mask] [−s process] pattern  start_addr  length
Print the words in memory that match pattern, beginning at the start_addr for length words.  The mask is ANDed (&) with each memory word and the result compared against the pattern.  The mask defaults to 0xffffffff. 

size [−w file] [−x] [structure_name . . . ]
Print the size of the designated structure.  The (−x) option prints the size in hexadecimal.  If no argument is given, a list of the structure names for which sizes are available is printed. 

sndd [−e] [−f] [−w file] [[−p]table_entry. . .]
Print the send descriptor table.

snode [−e] [−f] [−L lev] [−w file] [[−p]table_entry. . .]
Print information about open special files.

srmount [−e] [−w file] [[−p]table_entry. . .]
Print the server mount table.

stat [−w file]
Print out the system status.  This consists of general information about the system itself, information about when the system crashed (or the current time if used on a running system) and how long the system was running before a crash (or has been running).

stack [−w file] [−u] [process]

stack [−w file] [−k] [process]

stack [−w file] [[−p]−i start_addr]
Alias: s. 
Dump the stack.  The (−u) option prints the user stack.  The (−k) option prints the kernel stack.  The (−i) option prints the interrupt stack.  If no arguments are entered, the kernel stack for the current process is printed.  The interrupt stack and the stack for the current process are not available on a running system. 

stream [−e] [−f] [−w file] [[−p]table_entry. . .]
Print the streams table.

strstat [−w file]
Print streams statistics.

swapinfo [−w file] [−L lev] [-p]
Print the list of swap devices.

trace [−w file] [−r] [process]

trace [−w file] [[−p]−istart_addr]
Alias: t. 
Print stack trace. The kfp value is used with the −r option; the kfp function prints or sets the kfp (kernel frame pointer) value.  The interrupt option prints a trace of the interrupt stack beginning at start_addr.  The interrupt stack trace and the stack trace for the current process are not available on a running system. 

ts [−w file] virtual_address . . . 
Print text symbol closest to the designated address.

tsdptbl [−w file] [table_entry. . .]
Print the time-sharing scheduler parameter table. See ts_dptbl(4). 

tsproc [−w file]
Print information about processes in the time-sharing scheduler class.

tty [−e] [−f] [−l] [−w file] [−ttype[[−p]table_entry. . .]]

tty [−e] [−f] [−l] [−w file] [[−p]start_addr]
Valid types: iu. 
Print the tty table. If no arguments are given, the tty table for the console tty type is printed. If the −t option is used, the table for the single tty type specified is printed.  If no argument follows the type option, all entries in the table are printed.  A single tty entry may be specified using start_addr.  The −l option prints the line discipline information. 

uinode [−e] [−f] [−L lev] [−w file] [[−p]table_entry. . .]
Alias: ui. 
Print the ufs inode table. Higher levels show file blocks and then pages attached to the file.

user [−f] [−w file] [process]
Alias: u. 
Print the ublock for the designated process.

var [−w file]
Alias: v. 
Print the tunable system parameters.

vfs [−e] [−w file] [[−p]table_entry. . .]
Alias: mount, m. 
Print information about mounted file systems.

vfssw [−w file] [[−p]table_entry. . .]
Print information about configured file system types.

vnode [−L lev] [−w file] [[−p]vnode_addr. . .]
Print information about vnodes.

vtop [−w file] [−s process] start_addr. . .
Print the physical address translation of the virtual address start_addr. 

FILES

/dev/mem system image of currently running system

/dev/rmt/ctape1
used to access system image on cartridge tape

/dev/swap used to access system image in swap slice

SEE ALSO

ldsysdump(1M)
 

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