Re: [DynInst_API:] Patching every basic block of a given elf binary

[Xiaozhu Meng <mxz297@xxxxxxxxx>]

Hi Shuai,

BPatch_entry represents the entry of a function. You should use
BPatch_locBasicBlockEntry instead of BPatch_entry.

Or, you can try "BPatch_point* BPatch_basicBlock::findEntryPoint()".

Thanks

--Xiaozhu

On Sat, Aug 22, 2015 at 9:06 PM, Shuai Wang <wangshuai901@xxxxxxxxx> wrote:
> Dear list,
>
>
> I am a newbie to DynInst, and I am trying to instrument every basic blocks
> of a given elf binary. For example, to insert a basic block counter at the
> beginning of each basic block.
>
> I installed DynInst 8.2.1, and modified the example in DynInstAPI's appendix
> A, some code snippet like this:
>
>
>  .....
>
> BPatch_point *entryPointBB(BPatch_basicBlock *bb) {
>     BPatch_point *points;
>     points = bb->findPoint(BPatch_entry);
>
>     return points;
> }
>
> void binaryAnalysis(BPatch_addressSpace *app) {
>     BPatch_image *appImage = app->getImage();
>     int insns_access_memory = 0;
>     std::vector<BPatch_function *> funcs;
>     appImage->findFunction("main", funcs);
>
>     BPatch_flowGraph *fg = funcs[0]->getCFG();
>     std::set<BPatch_basicBlock *> blocks;
>     fg->getAllBasicBlocks(blocks);
>
>     std::set<BPatch_basicBlock *>::iterator block_iter;
>     for (block_iter = blocks.begin(); block_iter != blocks.end();
> ++block_iter)
>     {
>         BPatch_basicBlock *block = *block_iter;
>
>         BPatch_point * ps =  entryPointBB(block);
>
>         //patchBB(app, ps);
>         printf("%p\n", ps);    <------------------- (nil)
>     }
> }
> ....
>
> However, after the compilation, when I tried to execute the code, I find
> that BPatch_point ps does not get any value. As a result, the last printf
> statement print out a nil for this empty pointer..
>
>
> Here is my question: Am I missed anything? What should I do if I want to
> instrument every basic block at its front?
>
> I really appreciate if anyone can give me some help. Thank you a lot!
>
> Sincerely,
> Shuai
>
>
>
>
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