Subject: Re: [next-20170609] WARNING: CPU: 3 PID: 71167 at lib/idr.c:157 idr_replace

From: Tejun Heo <[email-masked]>
Date: Thu, 22 Jun 2017 14:58:37 -0400

On Thu, Jun 22, 2017 at 12:31:35AM +0100, Chris Wilson wrote:
> Quoting Tejun Heo (2017-06-13 14:58:49)
> > Cc'ing David Airlie.
> > 
> > This is from drm driver calling in idr_replace() w/ a negative id.
> > Probably a silly bug in error handling path?
> 
> No, this is the validation of an invalid userspace handle. The drm ABI
> for handles is supposed to be a full u32 range with 0 reserved for an
> invalid handle (constrained by the idr_alloc ofc). The WARN was
> introduced by 0a835c4f090a.

Matthew, did idr lost some of its range while being reimplemented
using radix tree?

Thanks.

-- 
tejun