check subcommand

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The check subcommand runs consistency checkers on kernel data structures.

Format

check

check ? | -?

check -h CheckerName

check [ -v ] [ -l level ] [ -n count ] CheckerName [ .SuffixName ] [ EffectiveAddress ]

check -e [ -v ] [ -l level ] CheckerName [ .SuffixName ] EffectiveAddress

Parameters

Item	Description
CheckerName	Specifies the name of the checker to run. Run the check command with no parameters to display the list of known checkers.
SuffixName	Specifies which of the suffixes of the given checker to run. Run the check command with the -h parameter to display the list of known suffixes for a given checker.
Effective Address	Specifies the effective address of the element to be validated or the effective address of the first element to be validated for lists. Symbols, hexadecimal values, or hexadecimal expressions can be used to specify the effective address.
-e	Specifies that only one element should be checked. This is equivalent to -n 1. An effective address must be specified if the -e parameter is specified.
-h	Displays help for each suffix of the specified checker.
-l level	Specifies the checking level the checker should use. This is a decimal value between 0 and 9. A value of 9 specifies the most detailed checking level and a value of 0 specifies no checking. The default value is 3 (light level) unless the -e flag is specified, in which case the default value is 7 (detailed level).
-n count	Specifies the number of elements (count is a decimal value) to validate.
-v	Specifies that the checker should run in verbose mode and display additional information if the checker supports this option.

Other

No aliases.

Examples

To display the list of known checkers, type the following:

check

Output similar to the following displays:

Please specify a checker name:
 
Kernel Checkers         Description
--------------------------------------------------------------------------------
proc                    Validate proc and pvproc structures
thread                  Validate thread and pvthread structures
 
Kernext Checkers        Description
--------------------------------------------------------------------------------

To display detailed help for a specified checker, type the following:

check -h proc

Output similar to the following displays:

Checker 'proc' is used to validate pvproc and proc structures:
proc                    check the global pvproc process table
proc <addr>             check a single pvproc
proc.pv_db <addr>       check a list of pvproc linked by pv_dbnext
proc.pv_sched <addr>    check a list of pvproc linked by pv_sched_next/back
proc.pv_siblings <addr> check a list of pvproc linked by pv_siblings
proc.pv_pgrp <addr>     check a list of pvproc linked by pv_pgrpl/pv_pgrpb
proc.pv_ttyl <addr>     check a list of pvproc linked by pv_ttyl
proc.pv_crid <addr>     check a list of pvproc linked by pv_cridnext
For each element, both pvproc and associated proc structure are validated
        <addr> shoud be the address of a pvproc structure (not a proc structure)

To run proc checker to validate the entire process table, type the following:
```
check -l 7 proc
```
Output similar to the following displays. In this example, a corruption is found in a flag.
```
Corruption found in pvproc.pv_flag: F100020E0000A400+0100 | RASCHK_BAD_BITMASK | Invalid flags
```
To run proc checker to perform a detailed check on a single process, type the following:
```
check -e -l 7 proc pvproc+006800
```

To run proc checker to validate the first five elements of a list of processes linked by the pv_siblings field starting at pvproc+00AC00 in verbose mode, type the following:

check -l 7 -n 5 -v proc.pv_siblings pvproc+00AC00

Output similar to the following displays:

Last element checked: F100020E0000AC00 <pvproc+00AC00>
Last element checked: F100020E0000C000 <pvproc+00C000>
Last element checked: F100020E0000BC00 <pvproc+00A400>
Corruption found in pvproc.pv_flag: F100020E0000A400+0100 | RASCHK_BAD_BITMASK | Invalid flags
Last element checked: F100020E0000B000 <pvproc+00BC00>
Last element checked: F100020E0000B000 <pvproc+00B000>