TH_DEFINE(8) Maintenance Procedures TH_DEFINE(8)

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(8) 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 additional 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(8) command, using the broadcast parameter. A log can be
terminated by running th_manage(8) 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:

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

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

o Use common to bias error definitions toward common
accesses.

o Use median to bias error definitions toward median
accesses.

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

o Use unbiased to create unbiased error definitions.

o 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).

o 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. Specifying 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), alarm(2), th_manage(8), ddi_check_acc_handle(9F),
ddi_check_dma_handle(9F)


April 9, 2016 TH_DEFINE(8)