Fw: Found a serious bug in OpenBios Tokenizer

[Mark W Wenning]

Greetings,

Our "OpenBIOS guy" thinks he found a bug in the tokenizer.
Can you comment?
What's the procedure for submitting fixes?

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Mark Wenning     [e-mail]     1-512-838-6263
Global FirmWare:  Networking and I/O, FC lackey
-----
Experience is what you get when you were expecting something else.     -
Anon
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----- Forwarded by Mark W Wenning/Austin/IBM on 03/07/2005 10:02 AM -----

David L                                                       
             Paktor/Almaden/IB                                             
             M                                                          To 
                                       [e-mail]                  
             03/04/2005 05:33                                           cc 
             PM                                                            
                                                                   Subject 
                                       Re: Found a serious bug in OpenBios 
                                       Tokenizer(Document link: Mark W     
                                       Wenning)

Hi, Mark.

As we spoke, I'm giving you some additional detail to describe the bug I
found.

Here's a recap of what I wrote before:

It has to do with  fload ;  When your source  fload s a file, that file is
supposed to be a continuation of your source-stream.

New definitions, as they are processed in the Tokenizer, are supposed to
get successive FCode tokens assigned to them, starting at 0x0800.

But when the OpenBios Tokenizer  fload s a new file, it resets the FCode
token-number, and starts assigning tokens from  0x0800 again.  So if you
have:

definition A
definition B
definition C
definition D

\   and then

fload File1                       \  which has:

definition E
definition F
definition G
definition H

and then you have something that intends to invoke  A B C  or D   you will
instead get  E F G  or  H , respectively....

Here's the additional material:

The source of the problem can be traced to the routines:  init_stream   and
init_output   in the file stream.c  .  They are both called at the
beginning of tokenization, one to prepare the source from which input will
be scanned, and the other to prepare the area to which output will be
delivered (broadly speaking).  When the  fload  directive is encountered,
the input source is suspended and a new one is activated; when the new one
is exhausted, the previous one is re-activated at the point from which it
was suspended.  So far so good.  The  init_stream  routine is called to
effectuate that activation.  Unfortunately, the line that initializes the
FCode token-numbers being assigning to new definitions -- the variable
called nextfcode -- occurs inside the  init_stream  routine.

I believe that moving that line to the  init_output  routine is sufficient
to fix this bug.

The two files attached are the new version of  stream.c  and a  diffs
file, going from the old version to the new.

Please incorporate this fix into the published code at the earliest
possible juncture.

David L. Paktor                  System Firmware Developer
System and Technology Group      Global Firmware Division
[e-mail]              David L Paktor/Almaden/IBM@IBMUS

18880 Homestead Rd.              Building 9945
Cupertino CA 95014               Room 1026
408-342-6110                     T/L 560-6110(See attached file: stream.c)
(See attached file: stream.diffs)