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.xlistinclude kernel.inc.list
if KDEBUG
DataBegin
externB fBootingexternW pGlobalHeap;externW hGlobalHeap
DataEnd
sBegin CODEassumes CS,CODE
externW gdtdsc
externNP check_lru_listexternNP check_free_listexternNP get_physical_address
;externFP ValidateFreeSpaces
;-----------------------------------------------------------------------;; CheckGlobalHeap ;; ;; The Global Heap is checked for consistency. First the forward links ;; are examined to make sure they lead from the hi_first to the hi_last. ;; Then the backward links are checked to make sure they lead from the ;; hi_last to the hi_first. Then the arenas are sequentially checked ;; to see that the moveable entries point to allocated handles and that ;; said handles point back. The handle table is then checked to see ;; that the number of used handles match the number of referenced ;; handles, and that the number of total handles matches the sum of the ;; free, discarded, and used handles. Finally the free list of handles ;; is checked. ;; ;; Arguments: ;; none ;; ;; Returns: ;; CF = 0 everything is just fine ;; all registers preserved ;; ;; Error Returns: ;; CF = 1 ;; DX = offending arena header ;; AX = 01h Forward links invalid ;; 02h Backward links invalid ;; 04h ga_handle points to free handle ;; 08h arena points to handle but not vice versa ;; 80h ga_sig is bad ;; DX = 0 ;; AX = 10h allocated handles don't match used handles ;; 20h total number of handles don't match up ;; 40h total number of free handles don't match up ;; ;; Registers Preserved: ;; All ;; ;; Registers Destroyed: ;; ;; Calls: ;; ;; History: ;; ;; Sat Nov 01, 1986 02:16:46p -by- David N. Weise [davidw] ;; Rewrote it from C into assembly. ;;-----------------------------------------------------------------------;
cProc CheckGlobalHeap,<PUBLIC,NEAR>cBegin nogen push ax push dx push bx push cx push di push si push ds push es
xor ax,ax xor dx,dx xor di,di SetKernelDS cmp pGlobalHeap,di jnz there_is_a_GlobalHeap jmp all_donethere_is_a_GlobalHeap: cmp fBooting, 1 jz no_check mov ds,pGlobalHeap UnSetKernelDS cmp [di].hi_check,di jnz checking_enabledno_check: jmp all_donechecking_enabled: mov cx,[di].hi_count mov dx,[di].hi_first mov es, dxforward_ho: push cx cCall get_physical_address, <es> add ax, 10h adc dx, 0 mov bx, es:[di].ga_size xor cx, cxrept 4 shl bx, 1 rcl cx, 1endm cmp es:[di].ga_owner, di je no_limit_check cmp es:[di].ga_handle, di je no_limit_check push bx push cx push si push ds smov ds, gdtdsc mov si, es:[di].ga_handle sel_check si sub bx, 1 sbb cx, 0 or cx, cx ; More than 1 selector? jz @F mov bx, -1@@: cmp [si], bx jne bad_limit mov ch, [si+6] and cx, 0F0Fh cmp ch, cl je ok_limitbad_limit: Debug_Out "gacheck: Bad limit for #SI"ok_limit: pop ds pop si pop cx pop bxno_limit_check:
cmp es:[di].ga_owner,GA_NOT_THERE ;286pmode has some of these jnz check_size ; with 0 size pop cx jmp short size_ok
check_size: add bx, ax adc cx, dx cCall get_physical_address, <es:[di].ga_next> cmp cx, dx pop cx mov dx, es xchg ax, dx jne forward_size_mismatch cmp dx, bx jne forward_size_mismatch
size_ok: mov ax, es mov dx, es:[di].ga_next mov es, dx cmp ax, es:[di].ga_prev jz size_and_next_matchforward_size_mismatch: cmp cx,1 jnz forward_links_invalidsize_and_next_match: loop xxxx cmp ax,[di].hi_last jz forward_links_okayforward_links_invalid: Debug_Out "gacheck: Forward links invalid" mov dx,ax mov ax,1 jmp all_donexxxx: jmp forward_ho
forward_links_okay:
xor ax, axclear_dx_all_done: xor dx,dxall_done: pop es pop ds pop si pop di pop cx pop bx or ax,ax jnz cgh_error pop dx pop ax retcgh_error: int 3 add sp,4 stc retcEnd nogen
sEnd CODE
endif
end
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