Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751820AbdH2K5N convert rfc822-to-8bit (ORCPT ); Tue, 29 Aug 2017 06:57:13 -0400 Received: from mga07.intel.com ([134.134.136.100]:4349 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751493AbdH2K5L (ORCPT ); Tue, 29 Aug 2017 06:57:11 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.41,444,1498546800"; d="scan'208";a="895131741" From: "Reshetova, Elena" To: Julia Lawall CC: "linux-kernel@vger.kernel.org" , "cocci@systeme.lip6.fr" , "Gilles.Muller@lip6.fr" , "nicolas.palix@imag.fr" , "mmarek@suse.com" , "keescook@chromium.org" , "ishkamiel@gmail.com" Subject: RE: [PATCH v3] provide rule for finding refcounters Thread-Topic: [PATCH v3] provide rule for finding refcounters Thread-Index: AQHTFoYnjE36oQ6350SbcuWGBTMgOqKG9qCAgBQiMAD///oxgIAAKt5A Date: Tue, 29 Aug 2017 10:57:07 +0000 Message-ID: <2236FBA76BA1254E88B949DDB74E612B6FF5FA49@IRSMSX102.ger.corp.intel.com> References: <1502884342-10702-1-git-send-email-elena.reshetova@intel.com> <2236FBA76BA1254E88B949DDB74E612B6FF5F9AD@IRSMSX102.ger.corp.intel.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-version: 11.0.0.116 dlp-reaction: no-action x-originating-ip: [163.33.239.181] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2925 Lines: 81 > On Tue, 29 Aug 2017, Reshetova, Elena wrote: > > > Hi, I am very sorry for the delayed reply. Finally unrigging my inbox :( > > > > > A few more small issues: > > > > > > When you deleted the disjunction, you kept the surrounding parentheses. > > > you can drop them (lines 83 and 85). > > > > > > I guess that the "del" regular expression is supposed to be matching > > > delete. But it also matches delayed, eg > > > > > > net/batman-adv/bridge_loop_avoidance.c:1495:8-27: > > > atomic_dec_and_test variation before object free at line 1507. > > > > Actually the idea is to match them both :) "delete" because it is obvious, > > "delay", exactly because "queue_delayed_work" (in addition to "queue_work") is a > common way some > > structure destruction might be scheduled. It might give false positives, since > > the queued work might not be related to freeing the object, but at least > > we don't miss such cases. The issue also that you do want to have "del" pattern > > since I think some functions are of kind xyz_del() also and I want to catch them as > well. > > Of course del then might catch some other non-queue related "delay", but I > haven't seen that many > > to consider it a problem. > > > > > > > > In the following result, the lines are at least quite far apart. I don't > > > know if there is some way to consider this to be a false positive: > > > > > > fs/btrfs/disk-io.c:708:14-33: atomic_dec_and_test > > > variation before object free at line 775. > > > > I actually think this is a valid result. Yes, there are a lot of things happening > > in between the dec_and_test and actual free on the buffer, but kernel structures > > can be so complicated that it might legitimately (like in this case) take that long > > for it to cleanup before the real free can be done. > > OK, if you are happy with the results of the regexps, I think that the > only remaining improvement was an extra pair of () where there was no > longer a disjuction. If you want to send it back, then I can ack it. Sure, I will fix that extra pair of brackets and resend. Thank you very much! Best Regards, Elena. > > julia > > > > > Best Regards, > > Elena. > > > > > > > > julia > > > > > > On Wed, 16 Aug 2017, Elena Reshetova wrote: > > > > > > > changes in v3: > > > > Removed unnessesary rule 4 conditions pointed by Julia. > > > > > > > > changes in v2: > > > > Following the suggestion from Julia the first rule is split into > > > > 2. The output does not differ that much between these two versions, > > > > but rule became more precise. > > > > > > > > Elena Reshetova (1): > > > > Coccinelle: add atomic_as_refcounter script > > > > > > > > scripts/coccinelle/api/atomic_as_refcounter.cocci | 133 > > > ++++++++++++++++++++++ > > > > 1 file changed, 133 insertions(+) > > > > create mode 100644 scripts/coccinelle/api/atomic_as_refcounter.cocci > > > > > > > > -- > > > > 2.7.4 > > > > > > > > > >