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

From: Chris Wilson
Date: Wed Jun 21 2017 - 19:32:00 EST

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.