Re: [PATCH] idr: explain WARN_ON_ONCE() on negative IDs out-of-rangeID

From: Thomas Gleixner
Date: Thu Feb 21 2013 - 04:11:08 EST

On Wed, 20 Feb 2013, Tejun Heo wrote:

> Until recently, when an negative ID is specified, idr functions used
> to ignore the sign bit and proceeded with the operation with the rest
> of bits, which is bizarre and error-prone. The behavior recently got
> changed so that negative IDs are treated as invalid but we're
> triggering WARN_ON_ONCE() on negative IDs just in case somebody was
> depending on the sign bit being ignored, so that those can be detected
> and fixed easily.
> We only need this for a while. Explain why WARN_ON_ONCE()s are there
> and that they can be removed later.
> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>

Acked-by : Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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