From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joonas Lahtinen Subject: Re: [PATCH] kernfs: Move faulting copy_user operations outside of the mutex Date: Thu, 31 Mar 2016 20:30:05 +0300 Message-ID: <1459445405.8191.32.camel@linux.intel.com> References: <1459421106-17788-1-git-send-email-chris@chris-wilson.co.uk> <20160331164915.GC24661@htj.duckdns.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTP id 9A8A16E274 for ; Thu, 31 Mar 2016 17:30:32 +0000 (UTC) In-Reply-To: <20160331164915.GC24661@htj.duckdns.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Tejun Heo , Chris Wilson , Daniel Vetter Cc: NeilBrown , Greg Kroah-Hartman , intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org List-Id: intel-gfx@lists.freedesktop.org T24gdG8sIDIwMTYtMDMtMzEgYXQgMTI6NDkgLTA0MDAsIFRlanVuIEhlbyB3cm90ZToKPiBPbiBU aHUsIE1hciAzMSwgMjAxNiBhdCAxMTo0NTowNkFNICswMTAwLCBDaHJpcyBXaWxzb24gd3JvdGU6 Cj4gPiAKPiA+IEEgZmF1bHQgaW4gYSB1c2VyIHByb3ZpZGVkIGJ1ZmZlciBtYXkgbGVhZCBhbnl3 aGVyZSwgYW5kIGxvY2tkZXAgd2FybnMKPiA+IHRoYXQgd2UgaGF2ZSBhIHBvdGVudGlhbCBkZWFk bG9jayBiZXR3ZWVuIHRoZSBtbS0+bW1hcF9zZW0gYW5kIHRoZQo+ID4ga2VybmZzIGZpbGUgbXV0 ZXg6Cj4gLi4uCj4gPiAKPiA+IFJlcG9ydGVkLWJ5OiBWaWxsZSBTeXJqw6Rsw6QgPHZpbGxlLnN5 cmphbGFAbGludXguaW50ZWwuY29tPgo+ID4gQnVnemlsbGE6IGh0dHBzOi8vYnVncy5mcmVlZGVz a3RvcC5vcmcvc2hvd19idWcuY2dpP2lkPTk0MzUwCj4gPiBTaWduZWQtb2ZmLWJ5OiBDaHJpcyBX aWxzb24gPGNocmlzQGNocmlzLXdpbHNvbi5jby51az4KPiA+IFJldmlld2VkLWJ5OiBKb29uYXMg TGFodGluZW4gPGpvb25hcy5sYWh0aW5lbkBsaW51eC5pbnRlbC5jb20+Cj4gPiBDYzogVmlsbGUg U3lyasOkbMOkIDx2aWxsZS5zeXJqYWxhQGxpbnV4LmludGVsLmNvbT4KPiA+IENjOiBKb29uYXMg TGFodGluZW4gPGpvb25hcy5sYWh0aW5lbkBsaW51eC5pbnRlbC5jb20+Cj4gPiBDYzogVGVqdW4g SGVvIDx0akBrZXJuZWwub3JnPgo+ID4gQ2M6IEdyZWcgS3JvYWgtSGFydG1hbiA8Z3JlZ2toQGxp bnV4Zm91bmRhdGlvbi5vcmc+Cj4gPiBDYzogTmVpbEJyb3duIDxuZWlsYkBzdXNlLmRlPgo+ID4g Q2M6IGxpbnV4LWtlcm5lbEB2Z2VyLmtlcm5lbC5vcmcKPiBBY2tlZC1ieTogVGVqdW4gSGVvIDx0 akBrZXJuZWwub3JnPgo+IAoKVGhhbmtzLgoKSSBoYXZlIGFwcGxpZWQgdGhpcyBsb2NhbGx5IHRv IG91ciByZXBvIHRvIGJlIGluY2x1ZGVkIGludG8gb3VyIENJCmJ1aWxkcy4KCldlIHdpbGwgZHJv cCB0aGUgbG9jYWwgcGF0Y2ggb25jZSB0aGlzIHdhdGVyZmFsbHMgZnJvbSB1cHN0cmVhbSB0byBv dXIKZHJtLWludGVsLW5pZ2h0bHkgcmVwby4KClJlZ2FyZHMsIEpvb25hcwotLSAKSm9vbmFzIExh aHRpbmVuCk9wZW4gU291cmNlIFRlY2hub2xvZ3kgQ2VudGVyCkludGVsIENvcnBvcmF0aW9uCgpf X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpJbnRlbC1nZngg bWFpbGluZyBsaXN0CkludGVsLWdmeEBsaXN0cy5mcmVlZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0 cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9saXN0aW5mby9pbnRlbC1nZngK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757915AbcCaRag (ORCPT ); Thu, 31 Mar 2016 13:30:36 -0400 Received: from mga01.intel.com ([192.55.52.88]:44575 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757644AbcCaRad (ORCPT ); Thu, 31 Mar 2016 13:30:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,423,1455004800"; d="scan'208";a="775592327" Message-ID: <1459445405.8191.32.camel@linux.intel.com> Subject: Re: [PATCH] kernfs: Move faulting copy_user operations outside of the mutex From: Joonas Lahtinen To: Tejun Heo , Chris Wilson , Daniel Vetter Cc: intel-gfx@lists.freedesktop.org, Ville =?ISO-8859-1?Q?Syrj=E4l=E4?= , Greg Kroah-Hartman , NeilBrown , linux-kernel@vger.kernel.org Date: Thu, 31 Mar 2016 20:30:05 +0300 In-Reply-To: <20160331164915.GC24661@htj.duckdns.org> References: <1459421106-17788-1-git-send-email-chris@chris-wilson.co.uk> <20160331164915.GC24661@htj.duckdns.org> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.5.2 (3.18.5.2-1.fc23) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On to, 2016-03-31 at 12:49 -0400, Tejun Heo wrote: > On Thu, Mar 31, 2016 at 11:45:06AM +0100, Chris Wilson wrote: > > > > A fault in a user provided buffer may lead anywhere, and lockdep warns > > that we have a potential deadlock between the mm->mmap_sem and the > > kernfs file mutex: > ... > > > > Reported-by: Ville Syrjälä > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94350 > > Signed-off-by: Chris Wilson > > Reviewed-by: Joonas Lahtinen > > Cc: Ville Syrjälä > > Cc: Joonas Lahtinen > > Cc: Tejun Heo > > Cc: Greg Kroah-Hartman > > Cc: NeilBrown > > Cc: linux-kernel@vger.kernel.org > Acked-by: Tejun Heo > Thanks. I have applied this locally to our repo to be included into our CI builds. We will drop the local patch once this waterfalls from upstream to our drm-intel-nightly repo. Regards, Joonas -- Joonas Lahtinen Open Source Technology Center Intel Corporation