Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752814Ab3GSVmD (ORCPT ); Fri, 19 Jul 2013 17:42:03 -0400 Received: from mail-lb0-f170.google.com ([209.85.217.170]:38872 "EHLO mail-lb0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752034Ab3GSVmA (ORCPT ); Fri, 19 Jul 2013 17:42:00 -0400 MIME-Version: 1.0 In-Reply-To: References: <1374191339-10124-1-git-send-email-mcgrof@do-not-panic.com> From: "Luis R. Rodriguez" Date: Fri, 19 Jul 2013 14:41:37 -0700 X-Google-Sender-Auth: TRBG-eF4GOReapYaUZlcX5O-3aw Message-ID: Subject: Re: [PATCH] backports: backport drvdata = NULL core driver fixes To: Julia Lawall Cc: Alan Stern , "backports@vger.kernel.org" , Hans de Goede , USB list , "linux-kernel@vger.kernel.org" , Jiri Slaby , Jiri Kosina , Felix Fietkau Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1592 Lines: 34 On Fri, Jul 19, 2013 at 2:27 PM, Julia Lawall wrote: > On Fri, 19 Jul 2013, Luis R. Rodriguez wrote: > >> On Fri, Jul 19, 2013 at 2:07 PM, Luis R. Rodriguez >> wrote: >> >> This is not a very good idea. Although setting drvdata to NULL allowed >> >> a lot of code to be removed, it also exposed a bunch of hidden bugs -- >> >> drivers were using the drvdata value even after their remove function >> >> returned. >> > >> > Eek, have we not SmPL'ify'd a proof yet to ensure code like this no >> > longer exists? Julia? :) >> >> Come to think of it, perhaps we should require *proof* with SmPL like >> this in future to avoid regressions ? > > Is it a concurrency problem? SmPL is not so good at that in the general > case. One would have to know a specific case where other functions of the > driver can be invoked after remove. Thanks Julia. In that case I'm going to just leave this in place given that if there's a bug upstream we'll get it fixed as soon as a respective patch gets upstream as well. That is, we are not using old drivers, we use the same upstream drivers so if a regression was found in backports the fix must go upstream s well. This is one of the benefits of backporting -- the range of users and testers increases and we still benefit from the upstream bandwagon. Luis -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/