th_define(1M)

Name | Synopsis | Description | Options | Examples | Notes | See Also

Name

th_define– create fault injection test harness error specifications

Synopsis

th_define [-n name -i instance| -P path] [-a acc_types] 
     [-r reg_number] [-l offset [length]] 
     [-c count [failcount]] [-o operator [operand]] 
     [-f acc_chk] [-w max_wait_period [report_interval]]

or 

th_define [-n name -i instance| -P path] 
     [-a log [acc_types] [-r reg_number] [-l offset [length]]] 
     [-c count [failcount]] [-s collect_time] [-p policy] 
     [-x flags] [-C comment_string] 
     [-e fixup_script [args]]

or 

th_define [-h]

Description

The th_define utility provides an interface to the bus_ops fault injection bofi device driver for defining error injection specifications (referred to as errdefs). An errdef corresponds to a specification of how to corrupt a device driver's accesses to its hardware. The command line arguments determine the precise nature of the fault to be injected. If the supplied arguments define a consistent errdef, the th_define process will store the errdef with the bofi driver and suspend itself until the criteria given by the errdef become satisfied (in practice, this will occur when the access counts go to zero).

You use the th_manage(1M) command with the start option to activate the resulting errdef. The effect of th_manage with the start option is that the bofi driver acts upon the errdef by matching the number of hardware accesses—specified in count, that are of the type specified in acc_types, made by instance number instance—of the driver whose name is name, (or by the driver instance specified by path) to the register set (or DMA handle) specified by reg_number, that lie within the range offset to offset + length from the beginning of the register set or DMA handle. It then applies operator and operand to the next failcount matching accesses.

If acc_types includes log, th_define runs in automatic test script generation mode, and a set of test scripts (written in the Korn shell) is created and placed in a sub-directory of the current directory with the name <driver>.test.<id> (for example, glm.test.978177106). A separate, executable script is generated for each access handle that matches the logging criteria. The log of accesses is placed at the top of each script as a record of the session. If the current directory is not writable, file output is written to standard output. The base name of each test file is the driver name, and the extension is a number that discriminates between different access handles. A control script (with the same name as the created test directory) is generated that will run all the test scripts sequentially.

Executing the scripts will install, and then activate, the resulting error definitions. Error definitions are activated sequentially and the driver instance under test is taken offline and brought back online before each test (refer to the -e option for more information). By default, logging applies to all PIO accesses, all interrupts, and all DMA accesses to and from areas mapped for both reading and writing. You can constrain logging by specifying additional acc_types, reg_number, offset and length. Logging will continue for count matching accesses, with an optional time limit of collect_time seconds.

Either the -n or -P option must be provided. The other options are optional. If an option (other than -a) is specified multiple times, only the final value for the option is used. If an option is not specified, its associated value is set to an appropriate default, which will provide maximal error coverage as described below.

Options

The following options are available:

-n name

Specify the name of the driver to test. (String)

-i instance

Test only the specified driver instance (-1 matches all instances of driver). (Numeric)

-P path

Specify the full device path of the driver to test. (String)

-r reg_number

Test only the given register set or DMA handle (-1 matches all register sets and DMA handles). (Numeric)

-a acc_types

Only the specified access types will be matched. Valid values for the acc_types argument are log, pio, pio_r, pio_w, dma, dma_r, dma_w and intr. Multiple access types, separated by spaces, can be specified. The default is to match all hardware accesses.

If acc_types is set to log, logging will match all PIO accesses, interrupts and DMA accesses to and from areas mapped for both reading and writing. log can be combined with other acc_types, in which case the matching condition for logging will be restricted to the specified addional acc_types. Note that dma_r will match only DMA handles mapped for reading only; dma_w will match only DMA handles mapped for writing only; dma will match only DMA handles mapped for both reading and writing.

-l offset [length]

Constrain the range of qualifying accesses. The offset and length arguments indicate that any access of the type specified with the -a option, to the register set or DMA handle specified with the -r option, lie at least offset bytes into the register set or DMA handle and at most offset + length bytes into it. The default for offset is 0. The default for length is the maximum value that can be placed in an offset_t C data type (see types.h). Negative values are converted into unsigned quantities. Thus, th_define -l 0 -1 is maximal.

-c count[failcount]

Wait for count number of matching accesses, then apply an operator and operand (see the -o option) to the next failcount number of matching accesses. If the access type (see the -a option) includes logging, the number of logged accesses is given by count + failcount - 1. The -1 is required because the last access coincides with the first faulting access.

Note that access logging may be combined with error injection if failcount and operator are nonzero and if the access type includes logging and any of the other access types (pio, dma and intr) See the description of access types in the definition of the -a option, above.

When the count and failcount fields reach zero, the status of the errdef is reported to standard output. When all active errdefs created by the th_define process complete, the process exits. If acc_types includes log, count determines how many accesses to log. If count is not specified, a default value is used. If failcount is set in this mode, it will simply increase the number of accesses logged by a further failcount - 1.

-o operator [operand]

For qualifying PIO read and write accesses, the value read from or written to the hardware is corrupted according to the value of operator:

EQ

operand is returned to the driver.

OR

operand is bitwise ORed with the real value.

AND

operand is bitwise ANDed with the real value.

XOR

operand is bitwise XORed with the real value.

For PIO write accesses, the following operator is allowed:

NO

Simply ignore the driver's attempt to write to the hardware.

Note that a driver performs PIO via the ddi_getX(), ddi_putX(), ddi_rep_getX() and ddi_rep_putX() routines (where X is 8, 16, 32 or 64). Accesses made using ddi_getX() and ddi_putX() are treated as a single access, whereas an access made using the ddi_rep_*(9F) routines are broken down into their respective number of accesses, as given by the repcount parameter to these DDI calls. If the access is performed via a DMA handle, operator and value are applied to every access that comprises the DMA request. If interference with interrupts has been requested then the operator may take any of the following values:

DELAY

After count accesses (see the -c option), delay delivery of the next failcount number of interrupts for operand number of microseconds.

LOSE

After count number of interrupts, fail to deliver the next failcount number of real interrupts to the driver.

EXTRA

After count number of interrupts, start delivering operand number of extra interrupts for the next failcount number of real interrupts.

The default value for operand and operator is to corrupt the data access by flipping each bit (XOR with -1).

-f acc_chk

If the acc_chk parameter is set to 1 or pio, then the driver's calls to ddi_check_acc_handle(9F) return DDI_FAILURE when the access count goes to 1. If the acc_chk parameter is set to 2 or dma, then the driver's calls to ddi_check_dma_handle(9F) return DDI_FAILURE when the access count goes to 1.

-w max_wait_period [report_interval]

Constrain the period for which an error definition will remain active. The option applies only to non-logging errdefs. If an error definition remains active for max_wait_period seconds, the test will be aborted. If report_interval is set to a nonzero value, the current status of the error definition is reported to standard output every report_interval seconds. The default value is zero. The status of the errdef is reported in parsable format (eight fields, each separated by a colon (:) character, the last of which is a string enclosed by double quotes and the remaining seven fields are integers):

ft:mt:ac:fc:chk:ec:s:"message" which are defined as follows:

ft

The UTC time when the fault was injected.

mt

The UTC time when the driver reported the fault.

ac

The number of remaining non-faulting accesses.

fc

The number of remaining faulting accesses.

chk

The value of the acc_chk field of the errdef.

ec

The number of fault reports issued by the driver against this errdef (mt holds the time of the initial report).

s

The severity level reported by the driver.

"message"

Textual reason why the driver has reported a fault.

-h

Display the command usage string.

-s collect_time

If acc_types is given with the -a option and includes log, the errdef will log accesses for collect_time seconds (the default is to log until the log becomes full). Note that, if the errdef specification matches multiple driver handles, multiple logging errdefs are registered with the bofi driver and logging terminates when all logs become full or when collect_time expires or when the associated errdefs are cleared. The current state of the log can be checked with the th_manage(1M) command, using the broadcast parameter. A log can be terminated by running th_manage(1M) with the clear_errdefs option or by sending a SIGALRM signal to the th_define process. See alarm(2) for the semantics of SIGALRM.

-p policy

Applicable when the acc_types option includes log. The parameter modifies the policy used for converting from logged accesses to errdefs. All policies are inclusive:

• Use rare to bias error definitions toward rare accesses (default).

• Use operator to produce a separate error definition for each operator type (default).

• Use common to bias error definitions toward common accesses.

• Use median to bias error definitions toward median accesses.

• Use maximal to produce multiple error definitions for duplicate accesses.

• Use unbiased to create unbiased error definitions.

• Use onebyte, twobyte, fourbyte, or eightbyte to select errdefs corresponding to 1, 2, 4 or 8 byte accesses (if chosen, the -xr option is enforced in order to ensure that ddi_rep_*() calls are decomposed into multiple single accesses).

• Use multibyte to create error definitions for multibyte accesses performed using ddi_rep_get*() and ddi_rep_put*().

Policies can be combined by adding together these options. See the NOTES section for further information.

-x flags

Applicable when the acc_types option includes log. The flags parameter modifies the way in which the bofi driver logs accesses. It is specified as a string containing any combination of the following letters:

w

Continuous logging (that is, the log will wrap when full).

t

Timestamp each log entry (access times are in seconds).

r

Log repeated I/O as individual accesses (for example, a ddi_rep_get16(9F) call which has a repcount of N is logged N times with each transaction logged as size 2 bytes. Without this option, the default logging behavior is to log this access once only, with a transaction size of twice the repcount).

-C comment_string

Applicable when the acc_types option includes log. It provides a comment string to be placed in any generated test scripts. The string must be enclosed in double quotes.

-e fixup_script [args]

Applicable when the acc_types option includes log. The output of a logging errdefs is to generate a test script for each driver access handle. Use this option to embed a command in the resulting script before the errors are injected. The generated test scripts will take an instance offline and bring it back online before injecting errors in order to bring the instance into a known fault–free state. The executable fixup_script will be called twice with the set of optional args— once just before the instance is taken offline and again after the instance has been brought online. The following variables are passed into the environment of the called executable:

DRIVER_PATH

Identifies the device path of the instance.

DRIVER_INSTANCE

Identifies the instance number of the device.

DRIVER_UNCONFIGURE

Has the value 1 when the instance is about to be taken offline.

DRIVER_CONFIGURE

Has the value 1 when the instance has just been brought online.

Typically, the executable ensures that the device under test is in a suitable state to be taken offline (unconfigured) or in a suitable state for error injection (for example configured, error free and servicing a workload). A minimal script for a network driver could be:

#!/bin/ksh driver=xyznetdriver ifnum=$driver$DRIVER_INSTANCE if [[ $DRIVER_CONFIGURE = 1 ]]; then ifconfig $ifnum plumb ifconfig $ifnum ... ifworkload start $ifnum elif [[ $DRIVER_UNCONFIGURE = 1 ]]; then ifworkload stop $ifnum ifconfig $ifnum down ifconfig $ifnum unplumb fi exit $?

The -e option must be the last option on the command line.

If the -a log option is selected but the -e option is not given, a default script is used. This script repeatedly attempts to detach and then re-attach the device instance under test.

Examples

Examples of Error Definitions

th_define -n foo -i 1 -a log

Logs all accesses to all handles used by instance 1 of the foo driver while running the default workload (attaching and detaching the instance). Then generates a set of test scripts to inject appropriate errdefs while running that default workload.

th_define -n foo -i 1 -a log pio

Logs PIO accesses to each PIO handle used by instance 1 of the foo driver while running the default workload (attaching and detaching the instance). Then generates a set of test scripts to inject appropriate errdefs while running that default workload.

th_define -n foo -i 1 -p onebyte median -e fixup arg -now

Logs all accesses to all handles used by instance 1 of the foo driver while running the workload defined in the fixup script fixup with arguments arg and -now. Then generates a set of test scripts to inject appropriate errdefs while running that workload. The resulting error definitions are requested to focus upon single byte accesses to locations that are accessed a median number of times with respect to frequency of access to I/O addresses.

th_define -n se -l 0x20 1 -a pio_r -o OR 0x4 -c 10 1000

Simulates a stuck serial chip command by forcing 1000 consecutive read accesses made by any instance of the se driver to its command status register, thereby returning status busy.

th_define -n foo -i 3 -r 1 -a pio_r -c 0 1 -f 1 -o OR 0x100

Causes 0x100 to be ORed into the next physical I/O read access from any register in register set 1 of instance 3 of the foo driver. Subsequent calls in the driver to ddi_check_acc_handle() return DDI_FAILURE.

th_define -n foo -i 3 -r 1 -a pio_r -c 0 1 -o OR 0x0

Causes 0x0 to be ORed into the next physical I/O read access from any register in register set 1 of instance 3 of the foo driver. This is of course a no-op.

th_define -n foo -i 3 -r 1 -l 0x8100 1 -a pio_r -c 0 10 -o EQ 0x70003

Causes the next ten next physical I/O reads from the register at offset 0x8100 in register set 1 of instance 3 of the foo driver to return 0x70003.

th_define -n foo -i 3 -r 1 -l 0x8100 1 -a pio_w -c 100 3 -o AND 0xffffffffffffefff

The next 100 physical I/O writes to the register at offset 0x8100 in register set 1 of instance 3 of the foo driver take place as normal. However, on each of the three subsequent accesses, the 0x1000 bit will be cleared.

th_define -n foo -i 3 -r 1 -l 0x8100 0x10 -a pio_r -c 0 1 -f 1 -o XOR 7

Causes the bottom three bits to have their values toggled for the next physical I/O read access to registers with offsets in the range 0x8100 to 0x8110 in register set 1 of instance 3 of the foo driver. Subsequent calls in the driver to ddi_check_acc_handle() return DDI_FAILURE.

th_define -n foo -i 3 -a pio_w -c 0 1 -o NO 0

Prevents the next physical I/O write access to any register in any register set of instance 3 of the foo driver from going out on the bus.

th_define -n foo -i 3 -l 0 8192 -a dma_r -c 0 1 -o OR 7

Causes 0x7 to be ORed into each long long in the first 8192 bytes of the next DMA read, using any DMA handle for instance 3 of the foo driver.

th_define -n foo -i 3 -r 2 -l 0 8 -a dma_r -c 0 1 -o OR 0x7070707070707070

Causes 0x70 to be ORed into each byte of the first long long of the next DMA read, using the DMA handle with sequential allocation number 2 for instance 3 of the foo driver.

th_define -n foo -i 3 -l 256 256 -a dma_w -c 0 1 -f 2 -o OR 7

Causes 0x7 to be ORed into each long long in the range from offset 256 to offset 512 of the next DMA write, using any DMA handle for instance 3 of the foo driver. Subsequent calls in the driver to ddi_check_dma_handle() return DDI_FAILURE.

th_define -n foo -i 3 -r 0 -l 0 8 -a dma_w -c 100 3 -o AND 0xffffffffffffefff

The next 100 DMA writes using the DMA handle with sequential allocation number 0 for instance 3 of the foo driver take place as normal. However, on each of the three subsequent accesses, the 0x1000 bit will be cleared in the first long long of the transfer.

th_define -n foo -i 3 -a intr -c 0 6 -o LOSE 0

Causes the next six interrupts for instance 3 of the foo driver to be lost.

th_define -n foo -i 3 -a intr -c 30 1 -o EXTRA 10

When the thirty-first subsequent interrupt for instance 3 of the foo driver occurs, a further ten interrupts are also generated.

th_define -n foo -i 3 -a intr -c 0 1 -o DELAY 1024

Causes the next interrupt for instance 3 of the foo driver to be delayed by 1024 microseconds.

Notes

The policy option in the th_define -p syntax determines how a set of logged accesses will be converted into the set of error definitions. Each logged access will be matched against the chosen policies to determine whether an error definition should be created based on the access.

Any number of policy options can be combined to modify the generated error definitions.

Bytewise Policies

These select particular I/O transfer sizes. Specifing a byte policy will exclude other byte policies that have not been chosen. If none of the byte type policies is selected, all transfer sizes are treated equally. Otherwise, only those specified transfer sizes will be selected.

onebyte

Create errdefs for one byte accesses (ddi_get8())

twobyte

Create errdefs for two byte accesses (ddi_get16())

fourbyte

Create errdefs for four byte accesses (ddi_get32())

eightbyte

Create errdefs for eight byte accesses (ddi_get64())

multibyte

Create errdefs for repeated byte accesses (ddi_rep_get*())

Frequency of Access Policies

The frequency of access to a location is determined according to the access type, location and transfer size (for example, a two-byte read access to address A is considered distinct from a four-byte read access to address A). The algorithm is to count the number of accesses (of a given type and size) to a given location, and find the locations that were most and least accessed (let maxa and mina be the number of times these locations were accessed, and mean the total number of accesses divided by total number of locations that were accessed). Then a rare access is a location that was accessed less than

(mean - mina) / 3 + mina

times. Similarly for the definition of common accesses:

maxa - (maxa - mean) / 3

A location whose access patterns lies within these cutoffs is regarded as a location that is accessed with median frequency.

rare

Create errdefs for locations that are rarely accessed.

common

Create errdefs for locations that are commonly accessed.

median

Create errdefs for locations that are accessed a median frequency.

Policies for Minimizing errdefs

If a transaction is duplicated, either a single or multiple errdefs will be written to the test scripts, depending upon the following two policies:

maximal

Create multiple errdefs for locations that are repeatedly accessed.

unbiased

Create a single errdef for locations that are repeatedly accessed.

operators

For each location, a default operator and operand is typically applied. For maximal test coverage, this default may be modified using the operators policy so that a separate errdef is created for each of the possible corruption operators.

See Also

kill(1), th_manage(1M), alarm(2), ddi_check_acc_handle(9F), ddi_check_dma_handle(9F)

Name | Synopsis | Description | Options | Examples | Notes | See Also