From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934571AbeE2Nol (ORCPT ); Tue, 29 May 2018 09:44:41 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:45660 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934183AbeE2Noj (ORCPT ); Tue, 29 May 2018 09:44:39 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Christian Brauner Cc: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, mingo@kernel.org, james.morris@microsoft.com, keescook@chromium.org, peterz@infradead.org, sds@tycho.nsa.gov, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, oleg@redhat.com References: <20180528215355.16119-1-christian@brauner.io> <20180528215355.16119-5-christian@brauner.io> <87r2lusl8l.fsf@xmission.com> <20180529124159.GB11221@mailbox.org> Date: Tue, 29 May 2018 08:44:22 -0500 In-Reply-To: <20180529124159.GB11221@mailbox.org> (Christian Brauner's message of "Tue, 29 May 2018 14:41:59 +0200") Message-ID: <87fu2apoeh.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1fNevU-0003Ol-AV;;;mid=<87fu2apoeh.fsf@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=97.119.174.25;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1/aPs6JEd5ipzP93vR70RmFaBLr9ahXwsw= X-SA-Exim-Connect-IP: 97.119.174.25 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa05 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_03 6+ unique symbols in subject * 0.0 T_TooManySym_02 5+ unique symbols in subject * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: XMission; sa05 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Christian Brauner X-Spam-Relay-Country: X-Spam-Timing: total 237 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 3.5 (1.5%), b_tie_ro: 2.4 (1.0%), parse: 1.42 (0.6%), extract_message_metadata: 17 (7.0%), get_uri_detail_list: 2.3 (1.0%), tests_pri_-1000: 7 (3.0%), tests_pri_-950: 1.71 (0.7%), tests_pri_-900: 1.38 (0.6%), tests_pri_-400: 25 (10.6%), check_bayes: 24 (10.0%), b_tokenize: 9 (3.8%), b_tok_get_all: 7 (2.9%), b_comp_prob: 2.9 (1.2%), b_tok_touch_all: 3.0 (1.2%), b_finish: 0.62 (0.3%), tests_pri_0: 171 (72.2%), check_dkim_signature: 0.59 (0.2%), check_dkim_adsp: 3.2 (1.4%), tests_pri_500: 4.5 (1.9%), rewrite_mail: 0.00 (0.0%) Subject: Re: [PATCH v1 04/20] signal: add copy_pending() helper X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christian Brauner writes: > On Tue, May 29, 2018 at 07:24:26AM -0500, Eric W. Biederman wrote: >> Christian Brauner writes: >> >> > Instead of using a goto for this let's add a simple helper copy_pending() >> > which can be called in both places. >> >> Ick no. As far as I can see this just confuses the logic of the >> collect_signal function. >> >> Instead of having two cases with an optional >> "sigdelset(&list->signal, sig)" if the signal is no longer in the queue, >> you are moving the core work of collect_signal into another function. >> >> At the very least this is going to make maintenance more difficult >> as now the work of this function is split into two functions. > > I do disagree here tbh. The goto jump into it the if part of an if-else > seems pretty nasty. > I also don't know why this should be confusing the logic. There's a > single function that is called in two places and it is declared directly > atop it's only caller. Additionally, recognizing a single name of a > function as being the same in two places is way easier then recognizing > that a multi-line pattern is the same in two places. But there are not two places. There is only one place. The logic might be cleaned up reorganizing the tests a little bit. Something like this perhaps. /* * Collect the siginfo appropriate to this signal. Check if * there is another siginfo for the same signal. */ list_for_each_entry(q, &list->list, list) { if (q->info.si_signo == sig) { if (first) break; first = q; } } /* Not still pending? */ if (!first || (&q->list != &list->list)) sigdelset(&list->signal, sig); if (first) { ... The logic at a high level is: Is there another instance of this signal pending? yes? Then don't "sigdelset" Do we have siginfo? yes? return it. no? dummy up a siginfo. Making that logic clearer would be nice. Obscuring it with an extra function just obstructs maintenance. Eric