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|
; SCCSID = @(#)segcheck.asm 1.2 85/07/24
TITLE SegCheck - internal consistency check
NAME SegCheck
.xlist
INCLUDE DOSSYM.INC
INCLUDE DEVSYM.INC
ShareF = FALSE
IF NOT SHAREF
include dosseg.asm
ENDIF
.list
AsmVars <NET, DEBUG>
DEBUG = FALSE
IF NOT SHAREF
CODE SEGMENT BYTE PUBLIC 'CODE'
ASSUME CS:DOSGroup
ELSE
SHARE SEGMENT BYTE PUBLIC 'SHARE'
ASSUME CS:SHARE
ENDIF
DEBUG = FALSE
BREAK <SegCheck - validate segments in MSDOS>
Off Macro reg,var
IF SHAREF
mov reg,offset var
else
mov reg,offset DOSGroup:var
endif
endm
zfmt MACRO fmts,args
local a,b
PUSHF
PUSH AX
PUSH BP
MOV BP,SP
If (not sharef) and (not redirector)
Table segment
a db fmts,0
Table ends
MOV AX,OFFSET DOSGROUP:a
else
jmp short b
a db fmts,0
if sharef
b: mov ax,offset share:a
else
b: mov ax,offset netwrk:a
endif
endif
PUSH AX
cargs = 2
IRP item,<args>
IFIDN <AX>,<item>
MOV AX,[BP+2]
ELSE
MOV AX,item
ENDIF
PUSH AX
cargs = cargs + 2
ENDM
invoke PFMT
ADD SP,Cargs
POP BP
POP AX
POPF
ENDM
segFrame Struc
segbp DW ?
segip DW ?
segmes dw ?
segtemp DW ?
segFrame ENDS
;
; SegCheck - assure that segments are correctly set up
;
; Inputs: top of stack points to:
; 2-byte jump
; byte flags 04h is ES 02h is DS 01 is CS/SS
; offset asciz message
;
; Outputs: message to screen (via INT 29h)
; Nothing modified (flags too)
Procedure SegCheck,NEAR
ASSUME DS:NOTHING,ES:NOTHING,SS:NOTHING
SaveReg <BP>
MOV BP,SP ; set up addressing
PUSHF
SaveReg <AX,BX,CX,DX>
MOV AL,BYTE PTR [BP].segtemp; get flags
MOV CX,SS
TEST AL,1 ; shall we use CS or SS?
JZ SegUseSS ; use SS
MOV CX,CS ; use CS instead
SegUseSS:
TEST AL,2 ; do we check DS?
JZ SegTestES ; no, go check ES
MOV DX,DS
CMP CX,DX
JZ SegTestES ; DS is valid, go check ES
MOV AX,[BP].segmes
zfmt <"Assumed DS invalid $s\n">,<AX>
SegTestES:
TEST AL,4 ; do we check ES?
JZ SegTestDone ; no, all done
MOV DX,ES
CMP CX,DX
JZ SegTestDone ; ES is valid, all done
MOV AX,[BP].segmes
zfmt <"Assumed ES invalid $s\n">,<AX>
SegTestDone:
RestoreReg <DX,CX,BX,AX>
POPF
RestoreReg <BP>
ret 4 ; release message, temp
EndProc SegCheck
IF NOT SHAREF
I_need DPBHead,DWORD
I_need BuffHead,DWORD
I_need sftFCB,DWORD
I_need AuxStack,BYTE
I_need IOStack,BYTE
I_need renbuf,byte
I_need CurrentPDB,WORD
I_need User_In_AX,WORD
extrn ECritDisk:NEAR
CritNOP label byte
RET
AstFrame STRUC
Astbp dw ?
Astip dw ?
Astmes dw ?
Astarg dd ?
AstFrame ENDS
Public SGCHK001S,SGCHK001E
SGCHK001S label byte
DPBMes DB "DPB assertion failed: ",0
BUFMes DB "BUF assertion failed: ",0
SFTMes DB "SFT assertion failed: ",0
BlankSp DB " ",0
Colon DB ":",0
Msg DW ?
SGCHK001E label byte
Table segment
Extrn SectPDB:WORD, SectRef:WORD
Table ends
; DPBCheck - validate a supposed DPB pointer
; Inputs: Pushed arguments
; Outputs: Message to screen
; Registers modified: none
Procedure DPBCheck,NEAR
MOV Msg,OFFSET DOSGroup:DPBMes
SaveReg <BP>
MOV BP,SP
PUSHF
SaveReg <AX,BX,DS,SI,ES,DI>
LES DI,DPBHead
LDS SI,[BP].Astarg
DPBLoop:CMP DI,-1
JZ DPBNotFound
invoke PointComp
JZ DPBRet
LES DI,ES:[DI.dpb_next_dpb]
JMP DPBLoop
DPBNotFound:
MOV AX,[BP].Astmes
zfmt <"$s$x:$x $s\n">,<msg,ds,si,AX>
CLI
a: JMP a ; slam the door.
DPBRet: RestoreReg <DI,ES,SI,DS,BX,AX> ; Done:
POPF
RestoreReg <BP>
RET 6
EndProc DPBCheck
; SFTCheck - validate a supposed SFT pointer
; Inputs: Pushed arguments
; Outputs: Message to screen
; Registers modified: none
Procedure SFTCheck,NEAR
MOV Msg,OFFSET DOSGroup:SFTMes
SaveReg <BP>
MOV BP,SP
PUSHF
SaveReg <AX,BX,DS,SI,ES,DI>
LDS SI,[BP].Astarg
XOR BX,BX ; i = 0;
SFTLoop:
SaveReg <BX>
invoke SFFromSFN ; while ((d=SF(i)) != NULL)
RestoreReg <BX>
JC Sft1
invoke PointComp
JZ DPBRet ; goto Done;
SFTNext:INC BX ; else
JMP SFTLoop ; i++;
SFT1: LES DI,sftFCB
MOV BX,ES:[DI.sfCount]
LEA DI,[DI.sfTable]
SFT2:
invoke PointComp
DPBRETJ:JZ DPBRet
ADD DI,SIZE sf_entry
DEC BX
JNZ SFT2
;
; The SFT is not in the allocated tables. See if it is one of the static
; areas.
;
Context ES
MOV DI,OFFSET DOSGROUP:AUXSTACK - SIZE SF_ENTRY
Invoke PointComp
JZ DPBRet
MOV DI,OFFSET DOSGROUP:RenBuf
Invoke PointComp
JZ DPBRetj
DPBNotFoundJ:
JMP DPBNotFound
EndProc SFTCheck
; BUFCheck - validate a supposed BUF pointer
; Inputs: Pushed arguments
; Outputs: Message to screen
; Registers modified: none
Procedure BUFCheck,NEAR
MOV Msg,OFFSET DOSGroup:BUFMes
SaveReg <BP>
MOV BP,SP
PUSHF
SaveReg <AX,BX,DS,SI,ES,DI>
;
; CheckDisk - make sure that we are in the disk critical section...
;
MOV AL,BYTE PTR ECritDisk
CMP AL,CritNOP
JZ CheckDone
MOV AX,CurrentPDB
CMP SectPDB + 2 * critDisk,AX
MOV AX,[BP].astmes
JZ CheckRef
zfmt <"$p: $x $s critDisk owned by $x\n">,<User_In_AX,AX,SectPDB+2*critDisk>
CheckRef:
CMP SectRef + 2 * critDisk,0
JNZ CheckDone
zfmt <"$p: $x $s critDisk ref count is 0\n">,<User_In_AX,AX>
CheckDone:
LDS SI,[BP].Astarg
LES DI,BUFFHead
BUFLoop:CMP DI,-1
JZ DPBNotFoundJ
invoke PointComp
JNZ BufNext
JMP DPBRet
BufNext:
LES DI,ES:[DI.buf_link]
JMP BUFLoop
EndProc BUFCheck
CODE ENDS
ELSE
SHARE ENDS
ENDIF
END
|
