From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chen Gang Subject: Re: [Suggestion] kernel/cgroup.c: about kfree after 'get_new_cssid' Date: Wed, 08 May 2013 10:00:14 +0800 Message-ID: <5189B1AE.4000906@asianux.com> References: <5188DB93.2080504@asianux.com> <5188DF27.4080000@huawei.com> <5188E391.6040505@asianux.com> <5189A166.9080301@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <5189A166.9080301-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Li Zefan Cc: tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" T24gMjAxM+W5tDA15pyIMDjml6UgMDg6NTAsIExpIFplZmFuIHdyb3RlOgo+Pj4gVGhlcmUncyBh IGJ1ZyBpbiBjZ3JvdXBfdW5sb2FkX3N1YnN5cygpIHRoYXQgaWRyX2Rlc3Ryb3koKSBzaG91bGQg YmUgY2FsbGVkIGFmdGVyCj4+PiA+PiBzcy0+Y3NzX2ZyZWUoKS4gVGhhdCBzYWlkLCBnaXZlbiB0 aGVyZSdzIG5vIG1vZHVsYXIgY2dyb3VwIHN1YnN5c3RlbSB1c2luZyBjc3NfaWQsCj4+PiA+PiBh bmQgdGhlIHdob2xlIGNzc19pZCB0aGluZyB3aWxsIGJlIGVsaW1pbmF0ZWQgaW4gMy4xMSwgd2h5 IGJvdGhlciBmaXhpbmcgaXQuCj4+PiA+Pgo+PiA+IAo+PiA+IEkganVzdCBmaW5kIGl0IGJ5IHJl YWRpbmcgY29kZSAoSSBhbHNvIHdhbnQgdG8gbGVhcm4gYWJvdXQga2VybmVsKS4KPj4gPiAKPj4g PiBJIGd1ZXNzLCBmb3Igc29tZSBzdGFibGUgdmVyc2lvbnMsIG1heSBmb2N1cyBvbiBpdCwgdGhl eSBhcmUgdGhlCj4+ID4gZGlmZmVyZW50IGJyYW5jaGVzIGZyb20gdGhlIGxhdGVzdCB2ZXJzaW9u Lgo+PiA+IAo+PiA+IFNvLCBpcyBpdCBzdWl0YWJsZSB0byBzZW5kIHJlbGF0ZWQgcGF0Y2ggZm9y IHRoZSBidWcgPwo+PiA+IAo+IEFzIEkgc2FpZCwgdGhlcmUncyBubyBtb2R1bGFyIGNncm91cCBz dWJzeXN0ZW0gdXNpbmcgY3NzX2lkLCBzbyB0aGUgYnVnCj4gZG9lc24ndCBleGlzdCBpbiByZWFs IHdvcmxkLgo+IAo+IAo+IAoKRXhjdXNlIG1lLCBteSBFbmdsaXNoIGlzIG5vdCBxdWl0ZSB3ZWxs LCBJIGd1ZXNzIHdoYXQgeW91IHNhaWQgaXM6CgogIGEuIGlkcl9kZXN0cm95KCkgc2hvdWxkIGJl IGNhbGxlZCBhZnRlciBzcy0+Y3NzX2ZyZWUoKQogIGIuIG5lZWQgY2hlY2sgdGhlIHJldHVybiB2 YWx1ZSBvZiBjZ3JvdXBfaW5pdF9pZHIoKSBpbiBjZ3JvdXBfaW5pdCgpLgoKICBidXQgYWxsIGZl YXR1cmVzIHdoaWNoIHJlbGF0ZWQgd2l0aCB0aGUgMiBpc3N1ZXMgYWJvdmUsIG5ldmVyIGJlIHVz ZWQKaW4gYW55IG1haW4gbGludXggbWFpbiBicmFuY2hlcy4KICBzbywgdGhlIDIgYnVncyBkb2Vz bid0IGV4aXN0IGluIHJlYWwgd29ybGQuCgpJcyB3aGF0IEkgZ3Vlc3MgY29ycmVjdCA/CgpUaGFu a3MuCgotLSAKQ2hlbiBHYW5nCgpBc2lhbnV4IENvcnBvcmF0aW9uCl9fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCkNvbnRhaW5lcnMgbWFpbGluZyBsaXN0CkNv bnRhaW5lcnNAbGlzdHMubGludXgtZm91bmRhdGlvbi5vcmcKaHR0cHM6Ly9saXN0cy5saW51eGZv dW5kYXRpb24ub3JnL21haWxtYW4vbGlzdGluZm8vY29udGFpbmVycw== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756687Ab3EHCBG (ORCPT ); Tue, 7 May 2013 22:01:06 -0400 Received: from intranet.asianux.com ([58.214.24.6]:30698 "EHLO intranet.asianux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755443Ab3EHCBE (ORCPT ); Tue, 7 May 2013 22:01:04 -0400 X-Spam-Score: -100.8 Message-ID: <5189B1AE.4000906@asianux.com> Date: Wed, 08 May 2013 10:00:14 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Li Zefan CC: tj@kernel.org, containers@lists.linux-foundation.org, cgroups@vger.kernel.org, "linux-kernel@vger.kernel.org" Subject: Re: [Suggestion] kernel/cgroup.c: about kfree after 'get_new_cssid' References: <5188DB93.2080504@asianux.com> <5188DF27.4080000@huawei.com> <5188E391.6040505@asianux.com> <5189A166.9080301@huawei.com> In-Reply-To: <5189A166.9080301@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2013年05月08日 08:50, Li Zefan wrote: >>> There's a bug in cgroup_unload_subsys() that idr_destroy() should be called after >>> >> ss->css_free(). That said, given there's no modular cgroup subsystem using css_id, >>> >> and the whole css_id thing will be eliminated in 3.11, why bother fixing it. >>> >> >> > >> > I just find it by reading code (I also want to learn about kernel). >> > >> > I guess, for some stable versions, may focus on it, they are the >> > different branches from the latest version. >> > >> > So, is it suitable to send related patch for the bug ? >> > > As I said, there's no modular cgroup subsystem using css_id, so the bug > doesn't exist in real world. > > > Excuse me, my English is not quite well, I guess what you said is: a. idr_destroy() should be called after ss->css_free() b. need check the return value of cgroup_init_idr() in cgroup_init(). but all features which related with the 2 issues above, never be used in any main linux main branches. so, the 2 bugs doesn't exist in real world. Is what I guess correct ? Thanks. -- Chen Gang Asianux Corporation