Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753654AbdFVS6m (ORCPT ); Thu, 22 Jun 2017 14:58:42 -0400 Received: from mail-yb0-f195.google.com ([209.85.213.195]:36416 "EHLO mail-yb0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753594AbdFVS6k (ORCPT ); Thu, 22 Jun 2017 14:58:40 -0400 Date: Thu, 22 Jun 2017 14:58:37 -0400 From: Tejun Heo To: Matthew Wilcox , Chris Wilson Cc: David Airlie , linuxppc-dev , linux-kernel , linux-next@vger.kernel.org, sachinp , Stephen Rothwell , Abdul Haleem Subject: Re: [next-20170609] WARNING: CPU: 3 PID: 71167 at lib/idr.c:157 idr_replace Message-ID: <20170622185837.GD18600@htj.duckdns.org> References: <1497278454.15415.50.camel@abdul.in.ibm.com> <20170613135849.GB28327@htj.duckdns.org> <149808789548.17054.471609626305557642@mail.alporthouse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <149808789548.17054.471609626305557642@mail.alporthouse.com> User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 603 Lines: 19 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