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Line 23... |
| 23 |
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23 |
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| 24 |
; Buffer used to remember previous command, when SvarCOM calls the buffered
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; Buffer used to remember previous command, when SvarCOM calls the buffered
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| 25 |
; input service at INT 21h,AH=0x0A.
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; input service at INT 21h,AH=0x0A.
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; This buffer is right before the stack, so in case of a stack overflow event
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; This buffer is right before the stack, so in case of a stack overflow event
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| 27 |
; (for example because of a "too ambitious" TSR) only this buffer is damaged,
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; (for example because of a "too ambitious" TSR) only this buffer is damaged,
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| 28 |
; and can be invalidated without much harm.
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; and can be invalidated without much harm. To detect such damage, SvarCOM's
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| 29 |
INPUTBUF: times 130 db 0
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| 30 |
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| 31 |
; This stack sig is a guardian value that is checked by the transient part of
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; transient part is appending a signature at the end of the buffer.
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| 32 |
; SvarCOM to detect possible stack overflows. If a stack overflow occurs, then
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| 33 |
; the INPUTBUFF area above is invalidated and stack signature reverted.
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30 |
INPUTBUF: times 132 db 0 ; 130 bytes for the input buffer + 2 for signature
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| 34 |
STACKSIG dw 0xCAFE
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| 35 |
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31 |
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| 36 |
; DOS int 21h functions that I use require at least 40 bytes of stack under
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32 |
; DOS int 21h functions that I use require at least 40 bytes of stack under
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| 37 |
; DOS-C (FreeDOS) kernel, so here I reserve 64 bytes juste to be sure
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33 |
; DOS-C (FreeDOS) kernel, so here I reserve 64 bytes juste to be sure
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| 38 |
STACKBUF db "XXX SVARCOM RMOD BY MATEUSZ VISTE XXXXXXXXXXXXXXXXXXXXXXXXXXXX"
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34 |
STACKBUF db "XXX SVARCOM RMOD BY MATEUSZ VISTE XXXXXXXXXXXXXXXXXXXXXXXXXXXX"
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| 39 |
STACKPTR dw 0
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35 |
STACKPTR dw 0
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