The liblockdep userspace lock debugging tool was merged to the mainline kernel tree in version 3.14. Unfortunately, the very next official release, linux 3.15, had a lockdep change that happened to break liblockdep. I have submitted a patch to fix the regression, but it is currently two steps away from the mainline tree (first Ingo Molnar will need to pull the fix from Sasha Levin, then Linus will need to pull from Ingo). Thus 3.16 might also get released without this fix. Here is a copy of the patch for those who wish to apply it manually to an affected kernel (3.15, and possibly 3.16): liblockdep-fix-regression.patch