Enforcer.doc

     Enforcer() 
     FindHit() 
     LawBreaker() 
     Move4K() 
     SegTracker() 


Enforcer


   NAME
	Enforcer V37 - An advanced version of Enforcer - Requires V37

   SYNOPSIS
	Enforcer - A tool to watch for illegal memory accesses

   FUNCTION
	Enforcer will use the MMU in the advanced 680x0 processors
	to set up MMU tables to watch for illegal accesses to memory
	such as the low-page and non-existent pages.

	To use, run Enforcer (plus any options you may wish)
	If you wish to detach, just use RUN >NIL:    INPUTS
	The options for Enforcer are as follows:

	QUIET/S        - This tells Enforcer to not complain about any invalid
	                 access and to just build MMU tables for cache setting
	                 reasons -- mainly used in conjunction with an
	                 Amiga BridgeBoard in a 68030 environment so that
	                 the system can run with the data cache turned on.
	                 In this case,
	                                RUN >NIL: Enforcer QUIET
	                 should be placed into the startup-sequence right
	                 after SetPatch.

	TINY/S         - This tells Enforcer to output a minimal hit.  The
	                 output is basically the first line of the Enforcer
	                 hit.  (see below)

	SMALL/S        - This tells Enforcer to output the hit line, the
	                 USP: line, and the Name: line.  (This means that
	                 no register or stack display will be output)

	SHOWPC/S       - This tells Enforcer to also output the two lines
	                 that contain the memory area around the PC where
	                 the hit happened.  Useful for disassembly.
	                 This option will not do anything if QUIET, SMALL or
	                 TINY output modes are selected.

	STACKLINES/K/N - This lets you pick the number of lines of stack
	                 backtrace to display.  The default is 2.  If set
	                 to 0, no stack backtrace will be displayed.  There
	                 is NO ENFORCED LIMIT on the number of lines.

	STACKCHECK/S   - This option tells Enforcer that you wish all of
	                 the long words displayed in the stack to be checked
	                 against the global seglists via SegTracker.
	                 This will tell you what seglist various return
	                 addresses are on the stack.  If you are not
	                 displaying stack information in the Enforcer hit
	                 then STACKCHECK will have nothing to check.
	                 If you are displaying stack information, then
	                 each long word will be check and only those which
	                 are in one of the tracked seglists will be
	                 displayed in a SegTracker line.
	                 The output will show the PC address first and
	                 then work its way back on the stack such that you
	                 can read it from bottom up as the order of calling
	                 or from top down as the stack-frame backtrace.

	AREGCHECK/S    - This option tells Enforcer that you wish all of
	                 the values in the Address Registers checked via
	                 SegTracker, much like STACKCHECK.

	DREGCHECK/S    - This option tells Enforcer that you wish all of
	                 the values in the Data Registers checked via
	                 SegTracker, much like STACKCHECK.

	DATESTAMP/S    - This makes Enforcer output a date and time with each
	                 hit.  Due to the nature of the way Enforcer must
	                 work, the time can not be read during the Enforcer
	                 hit itself so the time output will be the last time
	                 value the main Enforcer task set up.  Enforcer will
	                 update this value every second as to try to not
	                 use any real CPU time.  The time displayed in the
	                 hit will thus be exact.
	                 (Assuming the system clock is correct.)
	                 The date is output before anything from the hit
	                 other than the optional introduction string.

	DEADLY/S       - This makes Enforcer be a bit more nasty.  Normally,
	                 when an illegal read happens, Enforcer returns 0
	                 as the result of this read.  With this option,
	                 Enforcer will return $ABADFEED as the read data.
	                 This option can make programs with Enforcer hits
	                 cause even more hits.

	FSPACE/S       - This option will make the special $00F00000 address
	                 space available for writing to.  This is useful for
	                 those people with $00F00000 boards.  Mainly Commodore
	                 internal development work -- should only be used
	                 in that enviroment.

	NORELOADKICK/S - In A3000 SuperKickstart machines, Enforcer would
	                 force the Kickstart to be reloaded on a reboot.
	                 This option will disable this feature of Enforcer.
	                 Note that on some systems, reboots may not be
	                 reliable in this case.  Also note that if software
	                 tries to reboot the machine and it does not use the
	                 2.x ColdReboot() function, the system will not
	                 correctly reboot.  (It may, in fact, hang)

	VERBOSE/S      - This option will make Enforcer display information
	                 as to the mapping of the I/O boards and other
	                 technical information.  This information maybe useful
	                 in specialized debugging.

	LED/K/N        - This option lets you specify the speed at which
	                 the LED will be toggled for each Enforcer hit.
	                 The default is 1 (which is like it always was)
	                 Setting it to 0 will make Enforcer not touch
	                 the LED.  Using a larger value will make the
	                 flash take longer (such that it can be noticed
	                 when doing I/O models other than the default
	                 serial output)  The time that the flash will
	                 take is a bit more than 1.3 microseconds times
	                 the number.  So 1000 will be a bit more than
	                 1.3 milliseconds.  (Or 1000000 is a bit more than
	                 1.3 seconds.)

	PARALLEL/S     - This option will make Enforcer use the parallel port
	                 hardware rather than the serial port for output.

	RAWIO/S        - This option will make Enforcer stuff the hit report
	(special IO)     into an internal buffer and then from the main
	                 Enforcer process output the results via the
	                 RawPutChar() EXEC debugging LVO.  Since the output
	                 happens on the Enforcer task it is possible for a
	                 hit that ends in a system crash to not be able to
	                 be reported.  This option is here such that tools
	                 which can redirect debugging output can redirect
	                 the Enforcer output too.

	FILE/K         - This option will make Enforcer output the hit report
	(special IO)     but to a file insted of sending it to the hardware
	                 directly or using the RAWIO LVO.  A good example of
	                 such a file is CON:0/0/640/100/HIT/AUTO/WAIT.
	                 Another thing that can be done is to have a program
	                 sit on a named pipe and have Enforcer output to it.
	                 This program can then do whatever it feels like with
	                 the Enforcer hits.  (Such as decode them, etc.)
	                 *NOTE*  It is not a good idea to have Enforcer hits
	                 go to a file on a disk as if the system crashes
	                 during/after the Enforcer hit, the disk may
	                 become corrupt.

	STDIO/S        - This option will make Enforcer output the hit report
	(special IO)     to STDOUT.  This option only works from the CLI as it
	                 requires STDOUT.  It is best used with redirection or
	                 pipes.

	BUFFERSIZE/K/N - This lets you set Enforcer's internal output buffer
	                 for the special I/O options.  This option is only
	                 valid with the RAWIO, FILE, or STDIO options.
	                 The minimum setting is 8000.  The default is 8000.
	                 Having the right amount of buffer is rather
	                 important for the special I/O modes.  The reason
	                 is due to the fact that no operating system calls
	                 can be made from a bus error.  Thus, in the
	                 special I/O mode, Enforcer must store the output
	                 in this buffer and, via some special magic,
	                 wake up the Enforcer task to read the buffer and
	                 write it out as needed.  However, if a task is
	                 in Forbid() or Disable() when the Enforcer hit
	                 happens, the Enforcer task will not be able to
	                 output the results of the hit.  This buffer lets
	                 a number of hits happen even if the Enforcer task
	                 was unable to do the I/O.  If the number of
	                 hits that happen before the I/O was able to
	                 run gets too large, the last few hits will either
	                 be cut off completely or contain only partial
	                 information.

	INTRO/K        - This optional introduction string will be output
	                 at the start of every Enforcer hit.  For example:
	                 INTRO="*NBad Program!"   The default is no string.

	PRIORITY/K/N   - This lets you set Enforcer's I/O task priority.
	                 The default for this priority is 99.  In some
	                 special cases, you may wish to adjust this.
	                 It is, however, recommended that if you are using
	                 one of the special I/O options (RAWIO, FILE, or
	                 STDIO) that you keep the priority rather high.
	                 If the priority you supply is outside of the
	                 valid task priority range (-127 to 127) Enforcer
	                 will use the default priority.

	NOALERTPATCH/S - This option disables the patching of the EXEC
	                 Alert() function.  Normally Enforcer will patch
	                 this function to provide information as to what
	                 called Alert() and to prevent the Enforcer hits
	                 that a call to Alert() would cause.

	ON/S           - Mainly for completeness.  If not specified, it
	                 is assumed you want to turn ON Enforcer.

	QUIT=OFF/S     - Tells Enforcer to turn off.  Enforcer can also be
	                 stopped by sending a CTRL-C to its process.

   RESULTS
	When running, a set of MMU tables that map addresses that are not
	in the system's address map as invalid such that any access to them
	will cause an access fault.  Enforcer will then display this fact
	and generate a diagnostic message as to what the illegal access
	was.  The first memory page (the one starting at location 0) is
	also marked as invalid as many programming errors cause invalid
	access to these addresses.  These addresses are completely off
	limits to applications.

	When an	access violation happens, a report such as the following
	is output.

03-Apr-93  21:26:18
WORD-WRITE to  00000000        data=4444       PC: 07895CA4
USP:  078D692C SR: 0000 SW: 0729  (U0)(-)(-)  TCB: 078A2690
Data: DDDD0000 DDDD1111 DDDD2222 DDDD3333 DDDD4444 DDDD5555 DDDD6666 DDDD7777
Addr: AAAA0000 AAAA1111 AAAA2222 AAAA3333 AAAA4444 AAAA5555 07800804 --------
Stck: 00000000 07848E1C 00009C40 078A30B4 BBBBBBBB BBBBBBBB BBBBBBBB BBBBBBBB
Stck: BBBBBBBB BBBBBBBB BBBBBBBB BBBBBBBB BBBBBBBB 078E9048 00011DA8 DEADBEEF
----> 07895CA4 - "lawbreaker"  Hunk 0000 Offset 0000007C
PC-8: AAAA1111 247CAAAA 2222267C AAAA3333 287CAAAA 44442A7C AAAA5555 31C40000
PC *: 522E0127 201433FC 400000DF F09A522E 012611C7 00CE4EAE FF7642B8 0324532E
Name: "New_Shell"  CLI: "lawbreaker"  Hunk 0000 Offset 0000007C

LONG-READ from AAAA4444                        PC: 07895CA8
USP:  078D692C SR: 0015 SW: 0749  (U0)(F)(-)  TCB: 078A2690
Data: DDDD0000 DDDD1111 DDDD2222 DDDD3333 DDDD4444 DDDD5555 DDDD6666 DDDD7777
Addr: AAAA0000 AAAA1111 AAAA2222 AAAA3333 AAAA4444 AAAA5555 07800804 --------
Stck: 00000000 07848E1C 00009C40 078A30B4 BBBBBBBB BBBBBBBB BBBBBBBB BBBBBBBB
Stck: BBBBBBBB BBBBBBBB BBBBBBBB BBBBBBBB BBBBBBBB 078E9048 00011DA8 DEADBEEF
----> 07895CA8 - "lawbreaker"  Hunk 0000 Offset 00000080
PC-8: 247CAAAA 2222267C AAAA3333 287CAAAA 44442A7C AAAA5555 31C40000 522E0127
PC *: 201433FC 400000DF F09A522E 012611C7 00CE4EAE FF7642B8 0324532E 01266C08
Name: "New_Shell"  CLI: "lawbreaker"  Hunk 0000 Offset 00000080

25-Jul-93  17:15:06
Alert !! Alert 35000000     TCB: 07642F70     USP: 07657C10
Data: 00000000 DDDD1111 DDDD2222 DDDD3333 0763852A DDDD5555 DDDD6666 35000000
Addr: AAAA0000 AAAA1111 AAAA2222 AAAA3333 AAAA4444 0763852A 07400810 --------
Stck: 076385A0 00000000 0752EE9A 00002800 07643994 00000000 0762F710 076305F0
----> 076385A0 - "lawbreaker"  Hunk 0000 Offset 00000098

	Here is a breakdown of what these reports are saying:

	In the first report, the first line is the date stamp.

	The first line of each report describes the access violation
	and where it happened from.  In the case of a WRITE, the data
	that was being written will be displayed as well.  If an instruction
	mode access caused the fault, there will be an (INST) in the line.

	The first line may also contain the BUS ERROR message.  This will
	be displayed when an address that is valid in the system lists
	causes a physical bus fault during the access.  This usually
	will happen with plug-in cards or when a hardware problem causes
	some form of system fault.  Watch out, if this does show up, your
	system may be unstable and/or unreliable.

	The second line (starts USP:) displays the USER stack pointer (USP),
	the status register (SR:), the special status word (SW:).  It then
	displays the supervisor/user state and the interrupt level.  This
	will be from (U0) to (U7) or (S0) to (S7)  (S=Supervisor)  Next
	is the forbid state (F=forbid, -=not) and the disable state (D or -)
	of the task that was running when the access fault took place.
	Finally, the task control block address is displayed (TCB:)

	The next two lines contain the data and address register dumps from
	when the access fault happened.  Note that A7 is not listed here.
	It is the stack pointer and is listed as USP: in the line above.

	Then come the lines of stack backtrace.  These lines show the
	data on the stack.  If the stack is in invalid memory, Enforcer will
	display a message to that fact.

	If SegTracker was installed before Enforcer, the "---->" lines
	will display in which seglist the given addresses are in based on the
	global tracking that SegTracker does.  (See docs on SegTracker)
	If no seglist match is found, no lines will be displayed.
	One line will be displayed for each of the stack longwords asked
	for (see the STACKCHECK option) and one line for the PC address of
	the Enforcer hit.  (The PC line is always checked for is SegTracker
	is installed.)  The lines are in order: hit, first stack find,
	second stack find, etc.  This is useful for tracking down who
	called the routine that caused the Enforcer hit.

	Next, optionally, comes the data around the program counter when the
	access fault happened.  The first line (PC-8:) is the 8 long-words
	before the program counter.  The second line starts at the program
	counter and goes for 8 long words.

	The last line displays the name of the task that was running when
	the access fault took place.  If the task was a CLI, it will display
	the name of the CLI command that was running.  If the access fault
	was found to have happened within the seglist of a loaded program,
	the segment number and the offset from the start of the segment will
	be displayed.  (Note that this works for any LoadSeg()'ed process)

	Note that the name will display as "Processor Interrupt Level x"
	if the access happened in an interrupt.

	The other output that could happen is when a program or the OS
	calls the EXEC Alert function.  Enforcer catches these calls
	and will display the alert information as seen above.  (With the
	data and time if needed)

   WARNING
	Enforcer is for software testing.  In this role it is vital.
	Software that causes Enforcer hits may well not be able to run on
	newer hardware.  (Enforcer hits of high addresses on systems not
	running Enforcer but with a 68040 will most likely crash the system)
	Future systems and hardware will make this even more important.  The
	system can NOT survive software that causes Enforcer hits.

	However, Enforcer is NOT a system protector.  As a side effect, it
	may well keep a system from crashing when Enforcer hits happen, but
	it may just as well make the software crash earlier.  Enforcer is
	mainly a development and testing tool.

	Enforcer causes	no ill effects with correctly working software.
	If a program fails to work while Enforcer is active, you should
	contact the developer of that program.

   NOTES
	This is Enforcer V37.  Bryce Nesbitt came up with the original
	"Enforcer" that has been instrumental to the improvement in the
	quality of software on the Amiga.  The Amiga users and developers
	owe him a great deal for this.  Thank you Bryce!  Enforcer V37,
	however, is a greatly enhanced and more advanced tool.

	Enforcer V37 came about due to a number of needs.  These included
	the need for more output options and better performance.  It also
	marks the removal of all kludges that were in the older versions.
	Also, some future plans required some of these changes...

	In addition, the complete redesign was needed in order to also
	support the 68040.  The internal design of Enforcer is now set up
	such that CPU/MMU specific code can be cleanly accessed from the
	general house keeping aspect of the code.  The MMU bus error
	handling is, however, 100% CPU specific.

	Since AbsExecBase is in low memory, reads of this address are slower
	with Enforcer running.  Caching AbsExecBase locally is highly
	recommended since it is in CHIP memory and on systems with FAST
	memory, it will be faster to access the local cached value. (In
	addition to the performance increase when running Enforcer) Note
	that doing many reads of location 4 will hurt interrupt performance.

	When the Amiga produces an ALERT, EXEC places some magic numbers
	into some special locations in low memory.  The exact pattern
	changes between versions of the operating system.

	Enforcer will patch the EXEC function ColdReboot() in an attempt to
	"get out of the way" when someone tries to reboot the system.
	Enforcer will clean up as much as possible the MMU tables and then
	call the original LVO.  When Enforcer is asked to quit, it will
	check to make sure it can remove itself from this LVO. If it can
	not, it will not quit at that time.  If run from the shell, it will
	display a message saying that it tried but could not exit.  Enforcer
	will continue to be active and you can try later to deactivate it.

	Enforcer will also patch the EXEC function Alert() in an attempt to
	provide better tracking of other events in the system.  It is also
	patched such that dead-end alerts will correctly reset the system
	and be displayed.  With this patch in place, the normal alerts will
	not be seen but will be replaced by the Enforcer output shown
	above.  See LawBreaker for a more complete example of this.

   68020 NOTES
	The 68020 does not have a built-in MMU but has a co-processor
	feature that lets an external MMU be connected.  Enforcer MMU code
	is designed for use with 68851 MMU.  This is the some-what 68030
	compatible MMU by Motorola.  Enforcer uses the same code for both
	the 68030 and the 68020/68851.  For this reason, 68020/68851 users
	should see the 68030 NOTES section.

   68030 NOTES
	The 68030 uses cycle/instruction continuation and will
	supply the data on reads and ignore writes during an access
	fault rather than let the real bus cycle happen.  This means
	that on a fault caused by MMU tables, no bus cycle to the
	fault address will be generated.  (For those of you with analyzers)

	In some cases, the 68030 will have advanced the Program Counter
	past the instruction by the time the access fault happens.
	This is usually only on WRITE faults.  For this reason, the PC
	may either point at the instruction that caused the fault or
	just after the instruction that caused the fault.  (Which could
	mean that it is pointing to the middle of the instruction
	that caused the fault.)

	Note that there is a processor called 68EC030.  This processor
	has a disabled or defective MMU.  However, it may function well
	enough for Enforcer to think it has a fully functional MMU and
	thus Enforcer will attempt to run.  However, even if it looks like
	the MMU is functioning, it is not fully operational and thus may
	cause strange system activity and even crashes.  Do not assume
	that Enforcer is safe to use on 68EC030 systems.

   68040 NOTES
	Enforcer, on the 68040, *requires* that the 68040.library be
	installed and it requires an MMU 68040 CPU.  The 68EC040 does not
	have a MMU.  The 68LC040 does have an MMU and is supported. Enforcer
	will work best in a system with the 68040.library 37.10 or better
	but it does know how to deal with systems that do not have that
	version.

	Due to the design of the 68040, Enforcer is required to do a number
	of things differently.  For example, the MMU page size can only be
	either 8K or 4K.  This means that to protect the low 1K of memory,
	Enforcer will end up having to mark the first 4K of memory as
	invalid and emulate the access to the 3K of that memory that is
	valid. For this reason Enforcer moves a number of possible
	structures from the first 4K of memory to higher addresses.  This
	means that the system will continue to run at a reasonable speed.
	The first time Enforcer is run it may need to allocate memory for
	these structures that it will move.  Enforcer can never return this
	memory to the system.

	In addition to the fact that the 68040 MMU table size is different,
	the address fault handling is also different.  Namely, the 68040 can
	only rerun the cycle and not continue it like the 68030. This means
	that on a 68040, the page must be made available first and then made
	unavailable.  Make this work, Enforcer will switch the instruction
	that caused the error into trace mode and let it run with a special
	MMU setup.  When the trace exception comes in, the MMU is set up
	back to the way it was.  Enforcer does its best to keep debuggers
	working.  Note, however, that the interrupt level during a trace of
	a READ will end up being set to 7.  This is to prevent interrupts
	from changing the order of trace/MMU table execution.  The level
	will be restored to the original state before continuing.  Since T0
	mode tracing is also supported, there are also some changes in the
	way it operates.  T0 mode tracing is defined, on the 68040, to cause
	a trace whenever the instruction pipeline needed to be reloaded.
	While on the 68020/030 processors this was normally only for the
	branch instructions, in the 68040 this includes a large number of
	other instructions.  (Including NOP!)  Anyway, if an Enforcer hit
	happens while in T0 tracing mode, the trace will happen even on
	instructions that normally would not cause a T0 mode trace.  Since
	this may actually help in debugging and because it was not possible
	to do anything else, this method of operation is deemed acceptable.

	Another issue with the 68040 is that WRITE faults happen *after* the
	instruction has executed.  (Except for MOVEM)  In fact, it is common
	for the 68040 to execute one or more extra instructions before the
	WRITE fault is executed.  This design makes the 68040 much faster,
	but it also makes the Program Counter value that Enforcer can report
	for the fault much less likely to be pointing to the instruction
	that caused it.  The worst cases are sequences such as a write fault
	followed by a branch instruction.  In these cases, the branch is
	usually already executed before the write fault happens and thus the
	PC will be pointing to the target of the branch.  There is nothing
	that can be done within Enforcer to help out here.  You will just
	need to be aware of this and deal with it as best as possible.

	Along with the above issue, is the fact that since a write fault may
	be delayed, a read fault may happen before the write fault shows up.
	Internally, enforcer does not do special processing for these and
	they will not show up.  Since another hit was happening anyway, it
	is felt that it is best to just not report the hit.  Along the same
	lines, the hit generated from a MOVEM instruction may only show as a
	single hit rather than 1 for each register moved.

	On the Amiga, MOVE16 is not supported 100%.  Causing an Enforcer hit
	with a MOVE16 will cause major problems and maybe cause Enforcer or
	your task to lock.  Since MOVE16 is not supported, this is not a
	major issue.  Just watch out if you are using this 68040
	instruction.  (Also, watch out for the 68040 CPU bug with MOVE16)

	The functions CachePreDMA(), CachePostDMA(), and CacheControl() are
	patched when the 68040 MMU is turned on by Enforcer.  These
	functions are patched such the issues with DMA and the 68040
	COPYBACK data caches are addressed.  The 68040.library normally
	deals with this, however since Enforcer turns on the MMU, the method
	of dealing with it in the 68040.library will not work. For this
	reason, Enforcer will patch these and implement the required fix for
	when the MMU is on.  When Enforcer is asked to exit, it will check
	if it can remove itself from these functions.  If it can not, it
	will ignore the request to exit.  If Enforcer was run from the CLI,
	it will print a message saying that it can not exit when the attempt
	is made.

   WRITING DEBUGGERS
	If you wish to make a debugger that works with Enforcer to help
	pinpoint Enforcer hits in the application and not cause Enforcer
	hits itself, here are some simple tips and a bit of code.

   DEBUGGERS:  TRAPPING A HIT
	To trap a hit requires a number of things to work.

	First, the debugger itself must never cause an Enforcer hit.
	For help on that, see the "DEBUGGERS: NOT CAUSING A HIT"

	Second, the debugger must be global.  That is, you must be
	able to deal with a task getting a hit that is not the task
	under test.  There are a number of simple ways to deal with
	this, and I will leave this up to the debugger writer.
	(One method will be shown below)

	Third, the debugger must start *AFTER* Enforcer starts.
	If it is started before Enforcer, the hits will not be
	trapped.  (Note that this is not a problem)

	A very important point:  The code needs to be fast for
	the special case of location 4.  This is shown in the
	code below.  It is very important that this be fast.

	Note that it is much prefered that debuggers use the
	method described below for trapping hits.  It should
	be much more supportable this way as any of the tricky
	work that may need to be done in the hit processing
	will be handled by Enforcer itself.  If you wish the
	hit decoded, you can capture the Enforcer output via a
	pipe or some other method (such as RAWIO) or you can
	leave that issue up to the user.

	Now, given the above, the following bits of code can be
	used to get the debugger to switch into single-step mode
	at the point of the Enforcer hit.  You can also set some
	data value here to tell your debugger about this.

	;
	; The following code is inserted into the bus error vector.
	; Make sure you follow the VBR to find the vector.
	; Store the old vector in the address OldVector
	; Make sure you already have the single-step trap vector
	; installed before you install this.  Note that any extra
	; code you add in the comment area *MUST NOT* cause a bus
	; fault of any kind, including reading of location 4.
	;
	; This is the 68020 and 68030 version...
	;
	EnforcerHit:    ds.l    1                       ; Some private flag
	MyTask:         ds.l    1                       ; Task under test
	MyExecBase:     ds.l    1                       ; The local copy
	OldVector:      ds.l    1                       ; One long word
	NewVector:      cmp.l   #4,$10(sp)              ; 68020 and 68030
	                beq.s   TraceSkip               ; If AbsExecBase, OK
	                ;
	                ; Now, if you wish to only trap a specific task,
	                ; do the check at this point.  For example, a
	                ; simple single-task debugger would do something
	                ; like this:
	                move.l  a0,-(sp)                ; Save this...
	                move.l  MyExecBase(pc),a0       ; Get ExecBase...
	                move.l  ThisTask(a0),a0         ; Get ThisTask
	                cmp.l   MyTask(pc),a0           ; Are they the same?
	                move.l  (sp)+,a0                ; Restore A0 (no flags)
	                bne.s   TraceSkip               ; If not my task, skip
	                ;
	                bset.b  #7,(sp)                 ; Set trace bit...
	                ; If you have any other data to set, do it now...
	                ; Set as setting the EnforcerHit bit in your data...
	                addq.l	#1,EnforcerHit          : Count the hit...
	                ;
	TraceSkip:      move.l  OldVector(pc),-(sp)     ; Ready to return
	                rts
	;
	; This is the 68040 version...
	;
	NewVector040:   cmp.l   #4,$14(sp)              ; 68040
	                beq.s   TraceSkip040            ; If AbsExecBase, OK
	                ;
	                ; Now, if you wish to only trap a specific task,
	                ; do the check at this point.  For example, a
	                ; simple single-task debugger would do something
	                ; like this:
	                move.l  a0,-(sp)                ; Save this...
	                move.l  MyExecBase(pc),a0       ; Get ExecBase...
	                move.l  ThisTask(a0),a0         ; Get ThisTask
	                cmp.l   MyTask(pc),a0           ; Are they the same?
	                move.l  (sp)+,a0                ; Restore A0 (no flags)
	                bne.s   TraceSkip               ; If not my task, skip
	                ;
	                bset.b  #7,(sp)                 ; Set trace bit...
	                ; If you have any other data to set, do it now...
	                ; Set as setting the EnforcerHit bit in your data...
	                addq.l	#1,EnforcerHit          : Count the hit...
	                ;
	TraceSkip040:   move.l  OldVector(pc),-(sp)     ; Ready to return
	                rts

   DEBUGGERS:  NOT CAUSING A HIT
	In order not to cause Enforcer hits, you can do a number
	of things.  The easiest is to test the address with the TypeOfMem()
	EXEC function.  If TypeOfMem() returns 0, the address is not
	in the memory lists.  However, this does not mean it is not a
	valid address in all cases.  (ROM, chip registers, I/O boards)
	For those cases, you can build a "valid memory access table"
	much like Enforcer does.  Here is the code from Enforcer for
	the base memory tables:

	/*
	 * Mark_Address(mmu,start address,length,type)
	 */

	/*
	 * Special case the first page of CHIP RAM
	 */
	mmu=Mark_Address(mmu,0,0x1000,INVALID | NONCACHEABLE);

	/*
	 * Map in the free memory
	 */
	Forbid();
	mem=(struct MemHeader *)SysBase->MemList.lh_Head;
	while (mem->mh_Node.ln_Succ)
	{
	  mmu=Mark_Address(mmu,
	                   (ULONG)(mem->mh_Lower),
	                   (ULONG)(mem->mh_Upper)-(ULONG)(mem->mh_Lower),
	                   ((MEMF_CHIP & TypeOfMem(mem->mh_Lower)) ?
	                     (NONCACHEABLE | VALID) : (CACHEABLE | VALID)));
	  mem=(struct MemHeader *)(mem->mh_Node.ln_Succ);
	}
	Permit();

	/*
	 * Map in the autoconfig boards
	 */
	if (ExpansionBase=OpenLibrary("expansion.library",0))
	{
	struct	ConfigDev	*cd=NULL;

	  while (cd=FindConfigDev(cd,-1L,-1L))
	  {
	    /* Skip memory boards... */
	    if (!(cd->cd_Rom.er_Type & ERTF_MEMLIST))
	    {
	      mmu=Mark_Address(mmu,
	                       (ULONG)(cd->cd_BoardAddr),
	                       cd->cd_BoardSize,
	                       VALID | NONCACHEABLE);
	    }
	  }
	  CloseLibrary(ExpansionBase);
	}

	/*
	 * Now for the control areas...
	 */
	mmu=Mark_Address(mmu,0x00BC0000,0x00040000,VALID | NONCACHEABLE);
	mmu=Mark_Address(mmu,0x00D80000,0x00080000,VALID | NONCACHEABLE);

	/*
	 * and the ROM...
	 */
	mmu=Mark_Address(mmu,
	                 0x00F80000,
	                 0x00080000,
	                 VALID | CACHEABLE | WRITEPROTECT);

	/*
	 * If the credit card resource, make the addresses valid...
	 */
	if (OpenResource("card.resource"))
	{
	  mmu=Mark_Address(mmu,0x00600000,0x00440002,VALID | NONCACHEABLE);
	}

	/*
	 * If CD-based Amiga (CDTV, A570, etc.)
	 */
	if (FindResident("cdstrap"))
	{
	  mmu=Mark_Address(mmu,0x00E00000,0x00080000,VALID | NONCACHEABLE);
	  mmu=Mark_Address(mmu,0x00B80000,0x00040000,VALID | NONCACHEABLE);
	}

	/*
	 * Check for ReKick/ZKick/KickIt
	 */
	if ((((ULONG)(SysBase->LibNode.lib_Node.ln_Name)) >> 16) == 0x20)
	{
	  mmu=Mark_Address(mmu,
	                   0x00200000,
	                   0x00080000,
	                   VALID | CACHEABLE | WRITEPROTECT);
	}

   SEE ALSO
	"A master's secrets are only as good as the
	 master's ability to explain them to others."  -  Michael Sinz

   BUGS
	None?


FindHit


   NAME
	FindHit - A tool that can locate the source file and line number
	          that a SegTracker report happened at.

   SYNOPSIS
	FindHit will read the executable file and if there is debugging
	information in it, will try to locate the source file and line
	number that correspond to the Enforcer hit HUNK/OFFSET.

   FUNCTION
	FindHit uses the Lattice/SAS/MetaScope standard 'LINE'
	debug hunk to locate the closest line to the hunk/offset given.
	Note that this can only happen if the executable has the
	LINE debugging turned on.  (The LawBreaker program has this
	such that you can test this yourself.)

	In SAS/C 6.x, you need to compile with DEBUG=LINE or better
	and do not use the link option of NODEBUG.

	In SAS/C 5.x, you need to compile with -d1 or better.
	Note that FindHit works with the old SAS/C 5.x 'SRC '
	debugging information too.  This is required for -d2 or
	higher debugging support.  However, I do not have 'SRC ' hunk
	documentation and thus FindHit may be very specific to the
	SAS/C 5.x version of this hunk.

	In DICE (2.07 registered being the one I tried) the -d1
	debug switch also supports the 'LINE' debug hunk and
	works with FindHit.

	In HX68 and CAPE, you need to add the DEBUG directive to
	the assembly code program.  (See LawBreaker source)

	For other languages, or other versions of the above, please
	see the documentation that comes with the language.

   INPUTS
	FILE/A      - The executable file, with debugging information.

	OFFSETS/A/M - The HEX offset (with or without leading $)
	              If a hunk number other than the default
	              is needed, it is expressed as hunk:offset.
	              The default hunk is that of the last argument
	              or hunk 0 if no hunk number has been given.
	              For example:  12 $22 $3:12 22 4:$12 32 $0:$32
	              will find information for:
	              hunk $0, offset $12
	              hunk $0, offset $22
	              hunk $3, offset $12
	              hunk $3, offset $22
	              hunk $4, offset $12
	              hunk $4, offset $32
	              hunk $0, offset $32

   EXAMPLE
	FindHit FooBar $0342 $1:4F2 3:$1A 2C
	badcode.c : Line 184
	No line number information for Hunk $1, Offset $4F2
	badcode2.c : Line 12

	See the Enforcer documentation about issues dealing with the
	exact location of the Enforcer hit.  The line given may
	not be exactly where the hit happened.

	The way I use this is to always have line debugging turned on
	when I compile.  This does not change the quality of the code
	and takes only a small amount of extra disk space.  However,
	what I do is to link the program twice:  Once to a file called
	program.ld which contains all of the debugging information.
	Then, I link program.ld to program, stripping debug information.
	The command line for SLINK or BLINK is as follows:

	    BLINK program.ld TO program NODEBUG

	I keep both of these on hand; with program being the one I
	distribute and use.  When a hit happens, I can just use program.ld
	with FindHit to get the line number and source file that it happened
	in.  This way you can distribute your software without the debugging
	information and still be able to use FindHit on the actual code.
	(After all, that link command does nothing but strip symbol and
	debug hunks)

   NOTES
	Note that this program does nothing when run from the Workbench
	and thus does not have an icon.

   SEE ALSO
	"Quantum Physics:  The Dreams that Stuff is made of." - Michael Sinz

   BUGS


LawBreaker


   NAME
	LawBreaker - A quicky test of Enforcer

   SYNOPSIS
	This is a quick test of Enforcer and its reporting abilities.

   FUNCTION
	This program is used to make sure that Enforcer is correctly
	installed and operating.  LawBreaker works from either the CLI
	or Workbench.  It will try to read and write certain memory
	areas that will cause an Enforcer hit or four.

	LawBreaker will also do an Alert to show how Enforcer reports
	an Alert.

	Note that the LawBreaker executable has debugging information
	in it (standard LINE format debug hunk) such that you can
	try the FindHit program to find the line that causes the hit.

   INPUTS
	Just run it...

   RESULTS
	When running Enforcer, you will see some output from Enforcer.
	Output on a 68030 machine would look something like this:

25-Jul-93  17:15:04
WORD-WRITE to  00000000        data=0000       PC: 0763857C
USP:  07657C14 SR: 0004 SW: 04C1  (U0)(-)(-)  TCB: 07642F70
Data: DDDD0000 DDDD1111 DDDD2222 DDDD3333 0763852A DDDD5555 DDDD6666 DDDD7777
Addr: AAAA0000 AAAA1111 AAAA2222 AAAA3333 AAAA4444 0763852A 07400810 --------
Stck: 00000000 0752EE9A 00002800 07643994 00000000 076786D8 000208B0 2EAC80EE
Stck: 487AFD12 486C82C4 4EBA3D50 4EBAEA28 4FEF0014 52ACE2E4 204D43EC 88BC203C
----> 0763857C - "lawbreaker"  Hunk 0000 Offset 00000074
Name: "Shell"  CLI: "LawBreaker"  Hunk 0000 Offset 00000074

25-Jul-93  17:15:04
LONG-READ from AAAA4444                        PC: 07638580
USP:  07657C14 SR: 0015 SW: 0501  (U0)(F)(-)  TCB: 07642F70
Data: DDDD0000 DDDD1111 DDDD2222 DDDD3333 0763852A DDDD5555 DDDD6666 DDDD7777
Addr: AAAA0000 AAAA1111 AAAA2222 AAAA3333 AAAA4444 0763852A 07400810 --------
Stck: 00000000 0752EE9A 00002800 07643994 00000000 076786D8 000208B0 2EAC80EE
Stck: 487AFD12 486C82C4 4EBA3D50 4EBAEA28 4FEF0014 52ACE2E4 204D43EC 88BC203C
----> 07638580 - "lawbreaker"  Hunk 0000 Offset 00000078
Name: "Shell"  CLI: "LawBreaker"  Hunk 0000 Offset 00000078

25-Jul-93  17:15:04
BYTE-WRITE to  00000101        data=11         PC: 0763858A
USP:  07657C14 SR: 0010 SW: 04A1  (U0)(F)(D)  TCB: 07642F70
Data: 00000000 DDDD1111 DDDD2222 DDDD3333 0763852A DDDD5555 DDDD6666 DDDD7777
Addr: AAAA0000 AAAA1111 AAAA2222 AAAA3333 AAAA4444 0763852A 07400810 --------
Stck: 00000000 0752EE9A 00002800 07643994 00000000 076786D8 000208B0 2EAC80EE
Stck: 487AFD12 486C82C4 4EBA3D50 4EBAEA28 4FEF0014 52ACE2E4 204D43EC 88BC203C
----> 0763858A - "lawbreaker"  Hunk 0000 Offset 00000082
Name: "Shell"  CLI: "LawBreaker"  Hunk 0000 Offset 00000082

25-Jul-93  17:15:04
LONG-WRITE to  00000102        data=00000000   PC: 07638592
USP:  07657C14 SR: 0014 SW: 0481  (U0)(-)(D)  TCB: 07642F70
Data: 00000000 DDDD1111 DDDD2222 DDDD3333 0763852A DDDD5555 DDDD6666 DDDD7777
Addr: AAAA0000 AAAA1111 AAAA2222 AAAA3333 AAAA4444 0763852A 07400810 --------
Stck: 00000000 0752EE9A 00002800 07643994 00000000 076786D8 000208B0 2EAC80EE
Stck: 487AFD12 486C82C4 4EBA3D50 4EBAEA28 4FEF0014 52ACE2E4 204D43EC 88BC203C
----> 07638592 - "lawbreaker"  Hunk 0000 Offset 0000008A
Name: "Shell"  CLI: "LawBreaker"  Hunk 0000 Offset 0000008A

25-Jul-93  17:15:06
Alert !! Alert 35000000     TCB: 07642F70     USP: 07657C10
Data: 00000000 DDDD1111 DDDD2222 DDDD3333 0763852A DDDD5555 DDDD6666 35000000
Addr: AAAA0000 AAAA1111 AAAA2222 AAAA3333 AAAA4444 0763852A 07400810 --------
Stck: 076385A0 00000000 0752EE9A 00002800 07643994 00000000 0762F710 076305F0
----> 076385A0 - "lawbreaker"  Hunk 0000 Offset 00000098

	Now, using FindHit, you would type:

	FindHit LawBreaker 0:82

	and it will tell you the source file name and the line number
	where the hit happened.  See the FindHit documentation.

   NOTES
	If enforcer is not running, the program should not cause the
	system to crash.  It will, however, write to certain areas
	of low memory.  Also, it will cause read access of some
	addresses that may not exist.  This may cause bus faults.

   SEE ALSO
	"Quantum Physics:  The Dreams that Stuff is made of." - Michael Sinz

   BUGS
	There are 4 known Enforcer hits in this code and 1 alert, however,
	they will not be fixed.  ;^)


Move4K


   NAME
	Move4K - Moves as much out of the lower 4K of RAM as possible

   SYNOPSIS
	On 68040 systems, as much of the lower 4K of CHIP RAM as possible
	is removed from system use.

   FUNCTION
	On 68040 systems the MMU page sizes are 4K and 8K.  Enforcer
	uses the 4K page size.  Since watching for hits of low memory
	is a vital part of Enforcer, this means that the first 4K
	of RAM will be marked invalid.  On current systems, only
	the first 1K of RAM is invalid and thus 3K of RAM in that
	first 4K will end up needing to be emulated in Enforcer.
	In order to reduce the overhead that this causes (and the
	major performance loss) this program will try to move as much
	from that first 4K as possible and make any of the free
	memory within the first 4K inaccessible.

	Enforcer itself also has this logic, but it may be useful
	to be able to run this program as the first program in
	the Startup-Sequence (*AFTER* SetPatch) to try to limit
	the number of things that may use the lower 4K of RAM.

   INPUTS
	Just run it...  Can be run from CLI or Workbench

   RESULTS
	Any available memory in the lower 4K of CHIP RAM is removed
	plus a special graphics buffer is moved if it needs to be.
	After running this program you may have a bit less CHIP RAM
	than before.  You can run this program as many times as you
	wish since it only moves things if it needs to.

   NOTES
	This program will do nothing on systems without a 68040.
	It does not, however, check for the MMU and thus it will
	move the lower 4K even if the CPU is not able to run Enforcer.

	V39 of the operating system already does have the lowest
	MMU page empty and thus this program will effectively do
	nothing under V39.

   SEE ALSO
	"Eloquence is vehement simplicity"

   BUGS
	None.


SegTracker


   NAME
	SegTracker - A global SegList tracking utility

   SYNOPSIS
	A global tracking utility for disk loaded files including
	libraries and devices.  If placed in the startup-sequence
	right after SetPatch, it will track all disk loaded segments
	(other than those loaded by SetPatch)

   FUNCTION
	SegTracker will patch the DOS LoadSeg(), NewLoadSeg(), and UnLoadSeg()
	functions in order to track the SegLists that are loaded.
	SegTracker keeps these seglist stored in a "safe" manner and
	even handles programs which SegList split.

	The first time the program is run, it installs the patches
	and semaphore.  After that point, it just finds the semaphore
	and uses it.

	By using SegTracker, it will be possible to better identify
	where Enforcer hits come from when dealing with libraries
	and devices.  Basically, it is a system-global Hunk-o-matic.

	External programs can then pass in an address to SegTracker
	either via the command line or via the given function pointer
	in the SegTracker semaphore and get back results as to what
	hunk and offset the address is at.

	To work with the function directly, you need to find the
	the semaphore of "SegTracker" using FindSemaphore().
	The structure found will be the following:

	struct  SegSem
	{
	struct  SignalSemaphore seg_Semaphore;
	        SegTrack        *seg_Find;
	};

	The function pointer points to a routine that takes an address
	and two pointers to long words for returning the Segment number
	and Offset within the segment.  The function returns the name
	of the file loaded.  Note that you must call this function
	while in Forbid() and then copy the name as the seglist may
	be UnLoadSeg'ed at any moment and the name string will then
	no longer be in memory.

	typedef	char (* __asm SegTrack(register __a0 ULONG Address,
	                               register __a1 ULONG *SegNum,
	                               register __a2 ULONG *Offset));

	The above is for use in C code function pointer prototype
	in SAS/C 5 and 6.

   INPUTS
	SHOW/S  - Shows all of the segments being tracked.

	DUMP/S  - Displays all of the segment elements being tracked.

	FIND/M  - Find the hex (in $xxxxx format) address in
	          the tracked segments.  Multiple addresses
	          can be given.

	Options are not available from Workbench as they require
	the CLI.  However, you can run SegTracker from Workbench
	to install it.

   EXAMPLE USAGE
	/*
	 * A simple program that will "find" given addresses in the SegLists
	 * This program has been compiled with SAS/C 6.2 without errors or
	 * warnings.
	 *
	 * Compiler options:
	 * DATA=FARONLY PARAMETERS=REGISTER NOSTACKCHECK
	 * NOMULTIPLEINCLUDES STRINGMERGE STRUCTUREEQUIVALENCE
	 * MULTIPLECHARACTERCONSTANTS DEBUG=LINE NOVERSION
	 * OPTIMIZE OPTIMIZERINLOCAL NOICONS
	 *
	 * Linker options:
	 * FindSeg.o TO FindSeg SMALLCODE SMALLDATA NODEBUG LIB LIB:sc.lib
	 */
	#include 
	#include 
	#include 
	#include 
	#include 
	#include 
	#include 

	#include 
	#include 

	#include 
	#include 

	#include 

	#include "FindSeg_rev.h"

	#define EXECBASE (*(struct ExecBase **)4)

	typedef char (* __asm SegTrack(register __a0 ULONG,
	                               register __a1 ULONG *,
	                               register __a2 ULONG *));

	struct SegSem
	{
	struct SignalSemaphore seg_Semaphore;
	       SegTrack        *seg_Find;
	};

	#define SEG_SEM "SegTracker"

	#define TEMPLATE "FIND/M" VERSTAG

	#define OPT_FIND  0
	#define OPT_COUNT 1

	ULONG cmd(void)
	{
	struct ExecBase *SysBase;
	struct Library  *DOSBase;
	struct RDArgs   *rdargs;
	       ULONG    rc=RETURN_FAIL;
	struct SegSem   *segSem;
	       char     **hex;
	       LONG     opts[OPT_COUNT];

	  SysBase = EXECBASE;
	  if (DOSBase = OpenLibrary("dos.library",37))
	  {
	    memset((char *)opts, 0, sizeof(opts));

	    if (!(rdargs = ReadArgs(TEMPLATE, opts, NULL)))
	    {
	      PrintFault(IoErr(),NULL);
	    }
	    else if (CheckSignal(SIGBREAKF_CTRL_C))
	    {
	      PrintFault(ERROR_BREAK,NULL);
	    }
	    else if (segSem=(struct SegSem *)FindSemaphore(SEG_SEM))
	    {
	      rc=RETURN_OK;
	      if (opts[OPT_FIND])
	      {
	        for (hex=(char **)opts[OPT_FIND];(*hex);hex++)
	        {
	        char  *p;
	        ULONG val;
	        ULONG tmp[4];
	        ULONG c;

	          val=0;
	          p=*hex;
	          if (*p=='$') p++; /* Support $hex */
	          while (*p)
	          {
	            c=(ULONG)*p;
	            if ((c>='a') && (c<='f')) c-=32;
	            c-='0';
	            if (c>9)
	            {
	              c-=7;
	              if (c<10) c=16;
	            }

	            if (c<16)
	            {
	              val=(val << 4) + c;
	              p++;
	            }
	            else
	            {
	              val=0;
	              p=&p[strlen(p)];
	            }
	          }

	          /*
	           * Ok, we need to do this within Forbid()
	           * as segments can unload at ANY time, including
	           * during AllocMem(), so we use a stack buffer...
	           *
	           */
	          Forbid();
	          if (p=(*segSem->seg_Find)(tmp[0]=val,&tmp[2],&tmp[3]))
	          {
	          char Buffer[200];

	            stccpy(Buffer,p,200);
	            tmp[1]=(ULONG)Buffer;
	            VPrintf("$%08lx - %s : Hunk %ld, Offset $%08lx",tmp);

	            /*
	             * Now get the SegList address by passing the
	             * same pointer for both hunk & offset.  Note
	             * that this is only in the newer SegTrackers
	             * To test if this worked, check if the result
	             * of this call is either a hunk or an offset.
	             */
	            (*segSem->seg_Find)(val,&tmp[0],&tmp[0]);
	            /*
	             * This "kludge" is for compatibility reasons
	             * Check if result is the same as either the hunk
	             * or the offset.  If so, do not print it...
	             */
	            if ((tmp[0]!=tmp[2]) && (tmp[0]!=tmp[3]))
	            {
	              VPrintf(", SegList $%08lx",tmp);
	            }

	            PutStr("\n");
	          }
	          else VPrintf("$%08lx - Not found\n",tmp);
	          Permit();
	        }
	      }
	    }
	    else PutStr("Could not find SegTracker semaphore.\n");

	    if (rdargs) FreeArgs(rdargs);
	    CloseLibrary(DOSBase);
	  }
	  else if (DOSBase=OpenLibrary("dos.library",0))
	  {
	    Write(Output(),"Requires Kickstart 2.04 (37.175) or later.\n",43);
	    CloseLibrary(DOSBase);
	  }

	  return(rc);
	}

   NOTES
	The earlier this command is run, the better off it will be in
	tracking disk loaded segments.  Under debug usage, you may
	wish to run the command right *AFTER* SetPatch.

	Some things may not call UnLoadSeg() to free their seglists.
	There is no way SegTracker can follow a seglist that is not
	unloaded via the dos.library call to UnLoadSeg().  For this
	reason, SegTracker adds new LoadSeg() segments to the top
	of its list.  This way, if any old segments are still on
	the list but have been unloaded via some other method
	they will not clash with newer segments during the find operation.

	Note that the resident list is one such place where
	UnLoadSeg() is not called to free the seglist.  Thus,
	if something is made resident and then later unloaded
	it will still be listed as tracked by SegTracker.

	In order to support a new feature in CPR, the SegTracker function
	got a "kludge" added to it.  If a segment is found, you can then
	call the function again with the same address but with having
	both pointers point to the same longword of storage.  By doing
	this, the function will now return (in that longword) the
	SegList pointer (CPTR not BPTR) of the file that contains
	the address.  The reason this method was used was such that
	it was compatible with older SegTracker versions.  In older
	versions you would not get the result you wanted but you would
	also not crash.  See the example above for more details on how
	to use this feature.  The SegTracker FIND option has been
	expanded to include this information.

	Due to the fact that I am working on a design of a new set of
	debugging tools (Enforcer/SegTracker/etc)  I do not wish to
	expand the current SegTracker model in too many ways.

   SEE ALSO
	"Quantum Physics:  The Dreams that Stuff is made of." - Michael Sinz

   BUGS


Converted on 22 Apr 2000 with RexxDoesAmigaGuide2HTML 2.1 by Michael Ranner.