strange Bug

Björn Döbel doebel at os.inf.tu-dresden.de
Sat Nov 22 10:16:07 CET 2014


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Hi,

>>> And at 15c7a8 there is e12fff37 <=> blx r7 , which i've
>>> already found in MOE. But that's not what i'm looking for, is
>>> it?
>> 
>> This has nothing to do with MOE. When you objdump the myClient
>> binary, can you find the address in there? Does the binary
>> contain blx r7 as well?
> 
> No, this instruction or PC is not in myClient nor in myServer. But
> i can find the instruction in a shared lib which myServer uses.

No. We are definitely looking at myClient as this is where the page
fault happens. Please objdump myClient and find the page fault PC again.

>>> Goto f118a000, gives me the PC=15c7a8 again, where the Error 
>>> happens.
>> 
>> Yep, the UTCB contains the exception message informing the
>> exception handler about the page fault. This is the effect of
>> your page fault, not the cause.
> 
> Well then, where do i find the cause for the page error? Do i need
> a deeper unterstanding of the stack, or shall i just look at the
> instructions around PC=15c7a8 ?

Actually I still think we are looking for the instruction exactly at
this location. How does the objdump around this area look like?


Bjoern
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