From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA75EC2BC61 for ; Tue, 30 Oct 2018 18:29:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8B6562081B for ; Tue, 30 Oct 2018 18:29:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8B6562081B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727668AbeJaDY0 (ORCPT ); Tue, 30 Oct 2018 23:24:26 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:58582 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726522AbeJaDY0 (ORCPT ); Tue, 30 Oct 2018 23:24:26 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 62177341; Tue, 30 Oct 2018 11:29:51 -0700 (PDT) Received: from [10.1.196.62] (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7F6C43F557; Tue, 30 Oct 2018 11:29:50 -0700 (PDT) Subject: Re: [PATCH] soc: ti: QMSS: Fix usage of irq_set_affinity_hint To: Florian Fainelli , Santosh Shilimkar Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20181030111103.12110-1-marc.zyngier@arm.com> <1d813bdf-3161-1514-0368-48fbe24f2205@gmail.com> From: Marc Zyngier Openpgp: preference=signencrypt Autocrypt: addr=marc.zyngier@arm.com; prefer-encrypt=mutual; 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Linux aarch64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <1d813bdf-3161-1514-0368-48fbe24f2205@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/10/18 17:02, Florian Fainelli wrote: > On 10/30/18 4:11 AM, Marc Zyngier wrote: >> The Keystone QMSS driver is pretty damaged, in the sense that it >> does things like this: >> >> irq_set_affinity_hint(irq, to_cpumask(&cpu_map)); >> >> where cpu_map is a local variable. As we leave the function, this >> will point to nowhere-land, and things will end-up badly. >> >> Instead, let's use a proper cpumask that gets allocated, giving >> the driver a chance to actually work with things like irqbalance >> as well as have a hypothetical 64bit future. > > Since this is at least the second patch from you that I can see in this > area, would it make sense to sprinkle object_is_on_stack() checks > throughout irq_set_affinity_hint() to help catch offenders? I think I nuked the only two offenders in the tree. And to be honest, I'm far more worried about the use of to_cpumask() itself, because this can be wrong in quite a number of ways. As much as I dislike checkpatch, I wonder if having a rule checking for the usage of to_cpumask() would be a good idea... Thanks, M. -- Jazz is not dead. It just smells funny...