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HP OpenVMS Systems Documentation

OpenVMS Alpha System Analysis Tools Manual

Contents

Index

HELP

Displays information about the SDA utility, its operation, and the format of its commands.

Format

HELP [topic-name]

Parameter

topic-name
Topic for which you need information. A topic can be a command name or one of the following keywords:

Keyword Function

ANALYZE_USAGE_SUMMARY Describes the parameters and qualifiers for the ANALYZE/CRASH_DUMP and ANALYZE/SYSTEM DCL commands

CPU_CONTEXT Describes the concept of CPU context as it governs the behavior of SDA

EXECUTE_COMMAND Describes the use of @ file to execute SDA commands contained in a file

EXPRESSIONS Prints a description of SDA expressions

INITIALIZATION Describes the circumstances under which SDA executes an initialization file when first invoked

OPERATION Describes how to operate SDA at your terminal and by means of the site-specific startup procedure

PROCESS_CONTEXT Describes the concept of process context as it governs the behavior of SDA

SDA_CLUE_EXTENSION_COMMANDS Provides an overview of SDA CLUE (Crash Log Utility Extractor)

SDA_EXTENSION_ROUTINES Describes how to write, debug, and invoke an SDA extension and provides details of all callable routines

SDA_SPINLOCK_TRACING_COMMANDS Provides an overview of SDA SPL (Spinlock Tracing utility)

SYMBOLS Describes the symbols used by SDA

Qualifiers

None.

Description

The HELP command displays brief descriptions of SDA commands and concepts on the terminal screen (or sends these descriptions to the file designated in a SET OUTPUT command). You can request additional information by specifying the name of a topic in response to the Topic? prompt.
If you do not specify a parameter in the HELP command, it lists the features of SDA and those commands and topics for which you can request help, as follows:

Example

SDA> HELP
HELP


     The System Dump Analyzer (SDA) allows you to inspect the contents
     of memory as saved in the dump taken at crash time or as exists
     in a running system. You can use SDA interactively or in batch
     mode. You can send the output from SDA to a listing file. You can
     use SDA to perform the following operations:

                      Assign a value to a symbol
                      Examine memory of any process
                      Format instructions and blocks of data
                      Display device data structures
                      Display memory management data structures
                      Display a summary of all processes on the system
                      Display the SDA symbol table
                      Copy the system dump file
                      Send output to a file or device
                      Read global symbols from any object module
                      Send output to a file or device
                      Search memory for a given value

     For help on performing these functions, use the HELP command and
     specify a topic.

     Format

       HELP  [topic-name]




  Additional information available:

  ANALYZE_Usage_Summary ATTACH     CLUE       COPY       CPU_Context
  DEFINE     DUMP       EVALUATE   EXAMINE    Execute_Command       EXIT
  Expressions           FORMAT     HELP       Initialization        MAP
  MODIFY     Operation  Process_Context       READ       REPEAT
  SDA_CLUE_Extension_Commands      SDA_Extension_Routines
  SDA_Spinlock_Tracing_Commands    SEARCH     SET        SHOW       SPAWN
  SPL        Symbols    UNDEFINE   VALIDATE

Topic?

MAP

Transforms an address into an offset in a particular image.

Format

MAP address

Parameter

address
Address to be identified.

Qualifiers

None.

Description

The MAP command identifies the image name and offset corresponding to an address. With this information, you can examine the image map to locate the source module and program section offset corresponding to an address. MAP searches for the specified address in executive images first. It then checks activated images in process space to include those images installed using the /RESIDENT qualifier of the Install utility. Finally, it checks all image-resident sections in system space.
If the address cannot be found, MAP displays the following message:
%SDA-E-NOTINIMAGE, Address not within a system/installed image

Examples

#1
SDA> MAP G90308 Image Base End Image Offset SYS$VM Nonpaged read only 80090000 800ABA00 00000308

Examining the image map identified by this MAP command (SYS$VM.MAP) shows that image offset 308 falls within psect EXEC$HI_USE_PAGEABLE_CODE because the psect goes from offset 0 to offset 45D3:
. . . EXEC$HI_USE_PAGEABLE_CODE 00000000 000045D3 000045D4 ( 17876.) 2 ** 5... SYSCREDEL 00000000 0000149B 0000149C ( 5276.) 2 ** 5 SYSCRMPSC 000014A0 000045D3 00003134 ( 12596.) 2 ** 5 EXEC$NONPAGED_CODE 000045E0 0001B8B3 000172D4 ( 94932.) 2 ** 5... EXECUTE_FAULT 000045E0 0000483B 0000025C ( 604.) 2 ** 5 IOLOCK 00004840 000052E7 00000AA8 ( 2728.) 2 ** 5 LOCK_SYSTEM_PAGES . . .
Specifically, image offset 308 is located within source module SYSCREDEL. Therefore, to locate the corresponding code, you would look in SYSCREDEL for offset 308 in psect EXEC$HI_USE_PAGEABLE_CODE.

#2
SDA> MAP G550000 Image Base End Image Offset SYS$DKDRIVER 80548000 80558000 00008000

In this example, the MAP command identifies the address as an offset into an executive image that is not sliced. The base and end addresses are the boundaries of the image.

#3
SDA> MAP G550034 Image Base End Image Offset SYS$DUDRIVER Nonpaged read/write 80550000 80551400 00008034

In this example, the MAP command identifies the address as an offset into an executive image that is sliced. The base and end addresses are the boundaries of the image section that contains the address of interest.

#4
SDA> MAP GF0040 Image Resident Section Base End Image Offset MAILSHR 800F0000 80119000 00000040

The MAP command identifies the address as an offset into an image-resident section residing in system space.

#5
SDA> MAP 12000 Activated Image Base End Image Offset MAIL 00010000 000809FF 00002000

The MAP command identifies the address as an offset into an activated image residing in process-private space.

#6
SDA> MAP B2340 Compressed Data Section Base End Image Offset LIBRTL 000B2000 000B6400 00080340

The MAP command identifies the address as being within a compressed data section. When an image is installed with the Install utility using the /RESIDENT qualifier, the code sections are mapped in system space. The data sections are compressed into process-private space to reduce null pages or holes in the address space left by the absence of the code section. The SHOW PROCESS/IMAGE=ALL display shows how the data has been compressed; the MAP command searches this information to map an address in a compressed data section to an offset in an image.

#7
SDA> MAP 7FC06000 Shareable Address Data Section Base End Image Offset LIBRTL 7FC06000 7FC16800 00090000

The MAP command identifies the address as an offset into a shareable address data section residing in P1 space.

#8
SDA> MAP 7FC26000 Read-Write Data Section Base End Image Offset LIBRTL 7FC26000 7FC27000 000B0000

The MAP command identifies the address as an offset into a read-write data section residing in P1 space.

#9
SDA> MAP 7FC36000 Shareable Read-Only Data Section Base End Image Offset LIBRTL 7FC36000 7FC3F600 000C0000

The MAP command identifies the address as an offset into a shareable read-only data section residing in P1 space.

#10
SDA> MAP 7FC56000 Demand Zero Data Section Base End Image Offset LIBRTL 7FC56000 7FC57000 000E0000

The MAP command identifies the address as an offset into a demand zero data section residing in P1 space.

MODIFY DUMP

Allows a given byte, word, longword, or quadword in the dump to be modified.

Format

MODIFY DUMP {/BLOCK=n/OFFSET=n|/NEXT} [/CONFIRM=n] {/BYTE|/WORD|/LONGWORD (d)|/QUADWORD} value

Parameter

value
New value deposited in the specified location in the dump file.

Qualifiers

/BLOCK=n
Indicates block number to be modified. Required unless the /NEXT qualifier is given.
/OFFSET=n
Indicates byte offset within block to be modified. Required unless the /NEXT qualifier is given.
/NEXT
Indicates that the byte or bytes immediately following the location altered by the previous MODIFY DUMP command are to be modified. Used instead of the /BLOCK=n and /OFFSET=n qualifiers.
/CONFIRM=n
Checks existing contents of location to be modified.
/BYTE
Indicates that only a single byte is to be replaced.
/WORD
Indicates that a word is to be replaced.
/LONGWORD
Indicates that a longword is to be replaced. This is the default.
/QUADWORD
Indicates that a quadword is to be replaced.

Description

The MODIFY DUMP command is used on a dump file that cannot be analyzed without specifying the /OVERRIDE qualifier on the ANALYZE/CRASH_DUMP command. You can use the MODIFY DUMP command to correct the problem that prevents normal analysis of a dump file. You can only use the MODIFY DUMP command when you have invoked SDA with the ANALYZE/CRASH_DUMP/OVERRIDE command.

Important
This command is not intended for general use. It is provided for the benefit of Compaq support personnel when investigating crash dumps that cannot be analyzed in other ways.

If the block being modified is part of either the dump header, the error log buffers, or the compression map, the changes made are not seen when you issue the appropriate SHOW DUMP command, unless you first exit from SDA and then reissue the ANALYZE/CRASH_DUMP command.
The MODIFY DUMP command sets a bit in the dump header to indicate that the dump has been modified. Subsequent ANALYZE/CRASH_DUMP commands issued to that file produce the following warning message:
%SDA-W-DUMPMOD, dump has been modified

Examples

#1
SDA>> MODIFY DUMP/BLOCK=10/OFFSET=100/WORD FF

This example shows the dump file modified with the word at offset 100 in block 00000010 replaced by 00FF.

#2
SDA>> MODIFY DUMP/BLOCK=10/OFFSET=100/WORD 0/CONFIRM=EE

This example shows that the actual word value of 00FF at offset 100 in block 00000010 does not match the given value of 00EE. The following message is displayed:

#3
%SDA-E-NOMATCH, expected value does not match value in dump; dump not updated

#4
SDA>> MODIFY DUMP/BLOCK=10/OFFSET=100/WORD 0/CONFIRM=FF

This example shows the dump file modified with a word value of 00FF at offset 100 in block 00000010 replaced by 0000.

READ

Loads the global symbols contained in the specified file into the SDA symbol table.

Format

READ [/[NO]LOG|/RELOCATE =expression|/SYMVA=expression]
{/EXECUTIVE [directory spec]|/FORCE filespec
|/IMAGE filespec|filespec}

Parameters

directory-spec
Name of the directory containing the loadable images of the executive. This parameter defaults to SDA$READ_DIR, which is a search list of SYS$LOADABLE_IMAGES and SYS$LIBRARY.
filespec
Name of the device, directory, and file that contains the file from which you want to read global symbols. The filespec defaults to SYS$DISK:[default-dir]filename.type, where SYS$DISK and [default-dir] represent the disk and directory specified in your last DCL command SET DEFAULT. If no type has been given in filespec, SDA first tries .STB and then .EXE.
If no device or directory is given in the file specification, and the file specification is not found in SYS$DISK:[default_dir], then SDA attempts to open the file SDA$READ_DIR:filename.type. If no type has been given in filespec, SDA first tries .STB and then .EXE.
If the file name is the same as that of an execlet or image, but the symbols in the file are not those of the execlet or image, then you must use the /FORCE qualifier, and optionally /RELOCATE and /SYMVA qualifiers, to tell SDA how to interpret the symbols in the file.

Qualifiers

/EXECUTIVE directory-spec
Reads into the SDA symbol table all global symbols and global entry points defined within all loadable images that make up the executive. For all the execlets in the system, SDA reads the .STB or .EXE files in the requested directory.
/FORCE filespec
Forces SDA to read the symbols file, regardless of what other information or qualifiers are specified. If you do not specify the /FORCE qualifier, SDA may not read the symbols file if the specified filespec matches the image name in either the executive loaded images or the current processes activated image list, and one of the following conditions is true:

The image has a symbols vector (is a shareable image), and a symbols vector was not specified with the /SYMVA or /IMAGE qualifier.
The image is sliced, and slicing information was not provided with the /IMAGE qualifier.
The shareable or executive image is not loaded at the same address it was linked at, and the relocation information was not provided with either the /IMAGE or /RELOCATE qualifier.

The use of /FORCE [/SYMVA=addr][/RELOCATE=addr] filespec is a variant of the /IMAGE qualifier and avoids fixing up the symbols to match an image of the same name.
/IMAGE filespec
Searches the executive loaded image list and the current process activated image list for the image specified by filespec. If the image is found, the symbols are read in using the image symbol vector (if there is one) and either slicing or relocation information.
This is the preferred way to read in the .STB files produced by the linker. These .STB files contain all universal symbols, unless SYMBOL_TABLE=GLOBAL is in the linker options file, in which case the .STB file contains all universal and global symbols.
/LOG
/NOLOG
The /LOG qualifier causes SDA to output the %SDA-I-READSYM message for each symbol table file it reads. This is the default. You can specify the /LOG qualifier with any other combination of parameters and qualifiers.
The /NOLOG qualifier suppresses the output of the %SDA-I-READSYM messages. You can specify the /NOLOG qualifier with any other combination of parameters and qualifiers.
/RELOCATE=expression
Changes the relative addresses of the symbols to absolute addresses by adding the value of expression to the value of each symbol in the symbol table file to be read. This qualifier changes those addresses to absolute addresses in the address space into which the dump is mapped.
The relocation only applies to symbols with the relocate flag set. All universal symbols must be found in the symbol vector for the image. All constants are read in without any relocation.
If the image is sliced (image sections are placed in memory at different relative offsets than how the image is linked), then the /RELOCATE qualifier does not work. SDA compares the file name used as a parameter to the READ command against all the image names in the executive loaded image list and the current processes activated image list. If a match is found, and that image contains a symbol vector, an error results. At this point you can either use the /FORCE qualifier or the /IMAGE qualifier to override the error.
/SYMVA=expression
Informs SDA whether the absolute symbol vector address is for a shareable image (SYS$PUBLIC_VECTORS.EXE) or base system image (SYS$BASE_IMAGE.EXE). All symbols found in the file with the universal flag are found by referencing the symbol vector (that is, the symbol value is a symbol vector offset).

Description

The READ command symbolically identifies locations in memory and the definitions used by SDA for which the default files (SDA$READ_DIR:SYS$BASE_IMAGE.EXE and SDA$READ_DIR:REQSYSDEF.STB) provide no definition. In other words, the required global symbols are located in modules and symbol tables that have been compiled and/or linked separately from the executive. SDA extracts no local symbols from the files.
The file specified in the READ command can be the output of a compiler or assembler (for example, an .OBJ file).

Note
The READ command can read both OpenVMS VAX and OpenVMS Alpha format files. Do not use READ to read OpenVMS VAX format files that contain VAX specific symbols, as this might change the behavior of other OpenVMS Alpha SDA commands.

Most often the file is provided in SYS$LOADABLE_IMAGES. Many SDA applications, for instance, need to load the definitions of system data structures by issuing a READ command specifying SYSDEF.STB. Others require the definitions of specific global entry points within the executive image.
The files in SYS$LOADABLE_IMAGES define global locations within executive images, including those listed in Table 4-1. The actual list of executive images used varies, depending on platform type, devices, and the settings of several system parameters.

Table 4-1 Modules Defining Global Locations Within Executive Images
File Contents

ACME.EXE $ACM system service

CNX$DEBUG.EXE Connection Manager trace routines

DDIF$RMS_EXTENSION.EXE Support for Digital Document Interchange Format (DDIF) file operations

ERRORLOG.STB Error-logging routines and system services

EXCEPTION.STB ¹ Bugcheck and exception-handling routines and those system services that declare condition and exit handlers

EXEC_INIT.STB Initialization code

F11BXQP.STB File system support

FC$GLOGALS.STB Fibrechannel symbols

IMAGE_MANAGEMENT.STB Image activator and the related system services

IO_ROUTINES.STB ¹ $QIO system service, related system services (for example, $CANCEL and $ASSIGN), and supporting routines

LAT$RATING.EXE CPU load-balancing routines for LAT

LCK$DEBUG.EXE Lock manager trace routines

LMF$GROUP_TABLE.EXE Data structures for licensed product groups

LOCKING.STB Lock management routines and system services

LOGICAL_NAMES.STB Logical name routines and system services

MESSAGE_ROUTINES.STB System message routines and system services (including $SNDJBC and $GETTIM)

MSCP.EXE Disk MSCP server

MULTIPATH.STB ¹ Fibrechannel multipath support routines

NET$CSMACD.EXE CSMA/CD LAN management module

NET$FDDI.EXE FDDI LAN management module

NT_EXTENSION.EXE NT extensions for persona system services

PROCESS_MANAGEMENT.STB ¹ Scheduler, report system event, and supporting routines and system services

RECOVERY_UNIT_SERVICES.STB Recovery unit system services

RMS.EXE Global symbols and entry points for RMS

SECURITY.STB ¹ Security management routines and system services

SHELL xxK.STB Process shell

SPL$DEBUG.EXE Spinlock trace routines

SSPI.EXE Security Support Provider Interface

SYS$ xxDRIVER.EXE Run-time device drivers

SYS$ATMWORKS351.EXE PCI-ATM driver

SYS$CLUSTER.EXE OpenVMS Cluster support routines

SYS$CPU_ROUTINES_ xxxx.EXE Processor-specific data and initialization routines

SYS$EW1000A.EXE Gigabit Ethernet driver

SYS$GALAXY.STB OpenVMS Galaxy support routines

SYS$IPC_SERVICES.EXE Interprocess communication for DECdtm and Batch/Print

SYS$LAN.EXE Common LAN routines

SYS$LAN_ATM.EXE LAN routines for ATM

SYS$LAN_ATM4.EXE LAN routines for ATM (ForeThought)

SYS$LAN_CSMACD.EXE LAN routines for CSMA/CD

SYS$LAN_FDDI.EXE LAN routines for FDDI

SYS$LAN_TR.EXE LAN routines for Token Ring

SYS$MME_SERVICES.STB Media Management Extensions

SYS$NETWORK_SERVICES.EXE DECnet support

SYS$NTA.STB NT affinity routines and services

SYS$PUBLIC_VECTORS.EXE ² System service vector base image

SYS$SCS.EXE System Communication Services

SYS$TRANSACTION_SERVICES.EXE DECdtm services

SYS$UTC_SERVICES.EXE Universal Coordinated Time services

SYS$VCC.STB ¹ Virtual I/O cache

SYS$VM.STB System pager and swapper, along with their supporting routines, and management system services

SYS$XFCACHE.STB ¹ Extented File Cache

SYSDEVICE.STB Mailbox driver and null driver

SYSGETSYI.STB Get System Information system service ($GETSYI)

SYSLDR_DYN.STB Dynamic executive image loader

SYSLICENSE.STB Licensing system service ($LICENSE)

SYSTEM_DEBUG.EXE XDelta and SCD routines

SYSTEM_PRIMITIVES.STB ¹ Miscellaneous basic system routines, including those that allocate system memory, maintain system time, create fork processes, and control mutex acquisition

SYSTEM_SYNCHRONIZATION.STB ¹ Routines that enforce synchronization

TCPIP$BGDRIVER.STB ³ TCP/IP internet driver

TCPIP$INETACP.STB ³ TCP/IP internet ACP

TCPIP$INETDRIVER.STB ³ TCP/IP internet driver

TCPIP$INTERNET_SERVICES.STB ³ TCP/IP internet execlet

TCPIP$NFS_SERVICES.STB ³ Symbols for the TCP/IP NFS server

TCPIP$PROXY_SERVICES.STB ³ Symbols for the TCP/IP proxy execlet

TCPIP$PWIPACP.STB ³ TCP/IP PWIP ACP

TCPIP$PWIPDRIVER.STB ³ TCP/IP PWIP driver

TCPIP$TNDRIVER.STB ³ TCP/IP TELNET/RLOGIN server driver

TMSCP.EXE Tape MSCP server

VMS_EXTENSION.EXE VMS extensions for persona system services

¹Variations of these files also exist, for example, where the file name ends in "_MON." System parameters such as SYSTEM_CHECK determine which image is loaded.
²This file is located in SYS$LIBRARY.
³Only available if TCP/IP has been installed. These are found in SYS$SYSTEM, and are not automatically read in when you issue a READ/EXEC command.

Contents

Index

HP OpenVMS Systems Documentation

OpenVMS Alpha System Analysis Tools Manual

HELP

Format

Parameter

topic-name

Qualifiers

Description

Example

MAP

Format

Parameter

address

Qualifiers

Description

Examples

MODIFY DUMP

Format

Parameter

value

Qualifiers

/BLOCK=n

/OFFSET=n

/NEXT

/CONFIRM=n

/BYTE

/WORD

/LONGWORD

/QUADWORD

Description

Examples

READ

Format

Parameters

directory-spec

filespec

Qualifiers

/EXECUTIVE directory-spec

/FORCE filespec

/IMAGE filespec

/LOG /NOLOG

/RELOCATE=expression

/SYMVA=expression

Description

/LOG
/NOLOG