stack and proc

[john113]

please help...cannot get this code to work!

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.const
    para1 equ 0
    para2 equ 0

       
    .code                       
    start:                         
    print "Running.....",13,10
    invoke poo para1,para2                 
    print "Ended.",13,10
    invoke ExitProcess,0

;procedure code
poo proc para1:DWORD,para2:DWORD       
    push ebp
    mov ebp,esp
    push esi
    push edi
    mov eax,[ebp+8]
    mov ecx,[ebp+12]
    dec eax                     
    jnz poo                 
    pop edi
    pop esi
    pop ebp
    ret 8
   
poo endp                   

end start         




[NightWare]

maybe too much PUSH...  :wink jump after...

[raymond]

Use a debugger and step through your code. Watch what is happening in your registers and on the stack. You will then certainly understand why it doesn't work.

You're also missing a coma between your proc name and the first parameter when you invoke the proc.

[evlncrn8]

;procedure code
poo proc para1:DWORD,para2:DWORD       
    push ebp
    mov ebp,esp
    push esi
    push edi

    mov eax,[ebp+8]
    mov ecx,[ebp+12]

loopie:

    dec eax                     
    jnz loopie

    pop edi
    pop esi
    pop ebp
    ret 8
   
poo endp                   

something like that maybe, but your code will deadlock, u sure u know where you're wanting to loop...
can't actually see the point of the proc though, can you explain a little more?

[Darrel]

Each loop you mov 0 into eax then decrement eax (eax=-1), which makes it a never ending loop. From your procedure it looks like you want to setup the following loop:

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loop00000:

       dec     eax
       jnz     loop00000

[raymond]

Each loop you mov 0 into eax

I would think he's moving the old value of EBP into EAX, which is a value of ESP prior to pushing all those registers!!! The stack eventually runs out of space and the program crashes.

[Darrel]

You are correct Raymond.