Re: [DynInst_API:] the cause of uninstrumentable functions

[Xiaozhu Meng <xmeng@xxxxxxxxxxx>]

Hi Victor,

On Thu, Feb 12, 2015 at 6:17 PM, Victor van der Veen <vvdveen@xxxxxxxxx> wrote:

Hi Xiaozhu, Bill,

> I am working on the project of improving our abilities to resolve jump
> tables. My code is able to resolve the jump tables in strncmp, memcmp,
> and strcmp.
> I don't find a function "__cfree" in my local version of libc. But I
> do find a "libc_free", which contains a unresolved indirect branch and
> the unresolved indirect branch looks like an indirect tail call.
>
> My code is currently under integration and should be included in the
> next release of Dyninst.

This sounds very promising. Any chance that you can share a recent patch
so I can give this a try locally?

Unfortunately, my changes are not a small patch. Even though my code has much improved abilities to resolve jump tables, it causes very large overhead compared to the Dyninst version you have.

The time needed to parse a binary is almost doubled... I am optimizing this code.

On the other hand, if you think the parsing overhead is bearable, I can create a new branch for you to get my current code. Let me know your opinion.

Thanks

--Xiaozhu

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