Re: [ft-devel] More fuzzing for freetype2?

[Kostya Serebryany]

On Wed, Oct 7, 2015 at 1:18 AM, Werner LEMBERG <address@hidden> wrote:

> I've inserted this file into the corpus, and it added 2 more control flow
> edges (out of ~15000).
> Not much, but not zero.

The current function used for the fuzzer doesn't cover GX stuff at
all.  We have to extend it step by step to get a better FreeType
coverage.

Let's start from here. 

I think the more sustainable approach is to commit the target function into the FreeType git first.

I'll then re-target the bot to use that file instead of my own. 

Once that works, one of the domain experts (i.e. not me :)  will be able to add more stuff there. 

This way you will fully control what functionality is actually being fuzzed, and I will just monitor the infrastructure. 

Does that sounds reasonable?  

--kcc 

 

> The current target function handles any kind of font, so it may be
> rather slow in finding problems specific to a single font type.  For
> that we better write a separate target function. Would you like to
> help?

Yes, this would be great!  Have a look into the `ftmulti' FreeType
demo program :-) If you want to test named instances only, a simpler
approach of looping over all faces might work also with the recent
2.6.1 version (we have to add to test TTC support anyways to the
fuzzing routine).


    Werner