passing zero to PTR_ERR() warnings

Everyone seems to be hitting this warning, but I can't reproduce it at all. It came from a bug when I made pointers unsigned...

I though I fixed it in commit 8a9817501654 ("zero_to_err_ptr: fix fall out from unsigned pointer changes and improve") but now I can't reproduce it even when I revert that patch.

I'm using a clean smatch clone and a clean kernel clone, but I just can't trigger false positives. I get valid warnings still but not the false positives.

Can anyone help me figure this out?

regards,
dan carpenter