[DiSL-user] Taint Analysis with DiSL

[Lubomír Bulej]

Dear Alessio,

sorry for the misspelled attribute name. When I was replying to you, I looked
into the source code of the trunk version, which supports both.

In the trunk version, DiSL-Transformers supports a list of classes, wheres the
DiSL-Transformer only supports a single class name.


Sorry for the hold-up.


Best regards,
Lubomir

On 19/04/17 13:26, Alessio Gambi wrote:
> A quick follow up:
> 
> my code did not trigger because I misspelled the manifest attribute name
> (DiSL-Transformers).
> 
> The correct manifest attribute name is:
> DiSL-Transformer
> 
> Best
> 
> — Alessio
> 
> Alessio Gambi, Ph.D.
> gambi at st.cs.uni-saarland.de <mailto:gambi at st.cs.uni-saarland.de>
> 
> 
> 
>> On 19 Apr 2017, at 12:13, Alessio Gambi <gambi at st.cs.uni-saarland.de
>> <mailto:gambi at st.cs.uni-saarland.de>> wrote:
>>
>> Hi DiSL-ers,
>>
>> following Lubomir advice I implemented the  ch.usi.dag.disl.Transformer into
>> a class, then specified its fully qualified
>> name in the DiSL-Transformers attribute in the manifest of the
>> instumentation jar [1].
>>
>> However, I suspect that DiSL in not picking this up. I say I suspect because
>> I do not how to verify that my Transformer is instantiated
>> and used. I put a couple of System.out statements in the Transformer code
>> but did not see them out the console, but I might be looking at the wrong
>> console ;)
>>
>> I invoke my test application (one of the examples provided in the DiSL
>> distribution) using the disl.py script.
>>
>> Note that I see the DiSL snippets being triggered…
>>
>> Any advice  ?
>>
>> Best
>>
>> — Alessio
>>
>>
>> [1] Manifest
>> Manifest-Version: 1.0
>> DiSL-Classes: de.unisaarland.instrumentation.disl.ConflictDetection
>> DiSL-Transformers:
>> de.unisaarland.instrumentation.RWDependencyClassFileTransformer
>>
>> Alessio Gambi, Ph.D.
>> gambi at st.cs.uni-saarland.de <mailto:gambi at st.cs.uni-saarland.de>
>>
>>
>>
>>> On 18 Apr 2017, at 16:07, Lubomír Bulej <lubomir.bulej at d3s.mff.cuni.cz> wrote:
>>>
>>> Dear Alessio,
>>>
>>> DiSL itself was not meant to modify classes in this way, but it would
>>> certainly work if you give it classes that are already modified in this way.
>>>
>>>
>>> If you want to do everything at load time, you can also give DiSL a
>>> transformer class, and DiSL will use it to pre-transform class before starting
>>> to instrument it.
>>>
>>> You should implement the ch.usi.dag.disl.Transformer interface, and set the
>>> DiSL-Transformers attribute in the manifest of the jar file with
>>> instrumentation classes (the jar file with snippets which the DiSL server
>>> uses) to the fully qualified class name of your transformer class.
>>>
>>> We generally use exactly the pattern you describe, because you don't want to
>>> do a lot of work in the snippets (they are inlined as bytecode) and it can
>>> blow up the size of the methods significantly. So we usually call an analysis
>>> method from the snippets and include the event data as parameters, possibly
>>> with a bit of state stored in thread-local and synthetic local variables (the
>>> synthetic locals allow embedding small amounts of state information in stack
>>> frames).
>>>
>>> Let me know if it helps...
>>>
>>>
>>> Best regards,
>>> Lubomir
>>>
>>>
>>> On 18/04/17 15:14, Alessio Gambi wrote:
>>>> Hi DiSL-ers
>>>>
>>>> I was wondering if I can dynamically add private fields and
>>>> getters/setters to classes using DiSL.
>>>>
>>>> The reason for that is I want to implement a (special) taint analysis that
>>>> stores taint information directly inside
>>>> the objects and partially analyze them locally. In other terms, I do not
>>>> like to implement the following pattern:
>>>>
>>>> observe event -> publish the event to an event handler -> do the complete
>>>> analysis inside the event handler
>>>>
>>>> I already have the code which adds the fields to the classes… would DiSL
>>>> work it I pass to it code which is
>>>> already instrumented?
>>>>
>>>> Any thoughts?
>>>>
>>>> Best
>>>>
>>>> — Alessio
>>>>
>>>>
>>>>
>>>> Alessio Gambi, Ph.D.
>>>> gambi at st.cs.uni-saarland.de
>>>>
>>
> 
> 
> 
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-- 
Dept. Dist. and Dependable Systems
Faculty of Mathematics and Physics
Charles University, Czech Republic
Web: http://d3s.mff.cuni.cz
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