From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
Received: from vger.kernel.org (vger.kernel.org [23.128.96.18])
	by smtp.lore.kernel.org (Postfix) with ESMTP id 83EEBC001DE
	for <linux-kernel@archiver.kernel.org>; Wed, 19 Jul 2023 16:54:32 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S230375AbjGSQyb (ORCPT <rfc822;linux-kernel@archiver.kernel.org>);
        Wed, 19 Jul 2023 12:54:31 -0400
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38590 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S229540AbjGSQy3 (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Wed, 19 Jul 2023 12:54:29 -0400
Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31])
        by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 440FC91;
        Wed, 19 Jul 2023 09:54:28 -0700 (PDT)
X-IronPort-AV: E=McAfee;i="6600,9927,10776"; a="430289382"
X-IronPort-AV: E=Sophos;i="6.01,216,1684825200"; 
   d="scan'208";a="430289382"
Received: from fmsmga008.fm.intel.com ([10.253.24.58])
  by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2023 09:54:27 -0700
X-ExtLoop1: 1
X-IronPort-AV: E=McAfee;i="6600,9927,10776"; a="789481190"
X-IronPort-AV: E=Sophos;i="6.01,216,1684825200"; 
   d="scan'208";a="789481190"
Received: from smile.fi.intel.com ([10.237.72.54])
  by fmsmga008.fm.intel.com with ESMTP; 19 Jul 2023 09:54:24 -0700
Received: from andy by smile.fi.intel.com with local (Exim 4.96)
        (envelope-from <andy@kernel.org>)
        id 1qMARS-001aWY-2H;
        Wed, 19 Jul 2023 19:54:22 +0300
Date:   Wed, 19 Jul 2023 19:54:22 +0300
From:   Andy Shevchenko <andy@kernel.org>
To:     Samuel Holland <samuel.holland@sifive.com>
Cc:     Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <brgl@bgdev.pl>,
        Emil Renner Berthing <emil.renner.berthing@canonical.com>,
        Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-riscv@lists.infradead.org
Subject: Re: [PATCH v2 3/4] gpio: sifive: Get the parent IRQ's domain from
 its irq_data
Message-ID: <ZLgVPv7zdoaiUCU6@smile.fi.intel.com>
References: <20230719163446.1398961-1-samuel.holland@sifive.com>
 <20230719163446.1398961-4-samuel.holland@sifive.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230719163446.1398961-4-samuel.holland@sifive.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, Jul 19, 2023 at 09:34:44AM -0700, Samuel Holland wrote:
> Do not parse the devicetree again when the data is already available
> from the IRQ subsystem. This follows the example of the ThunderX and
> X-Gene GPIO drivers. The ngpio check is needed to avoid a possible
> out-of-bounds read.

...

> -	girq->parent_domain = parent;
> +	girq->parent_domain = irq_get_irq_data(chip->irq_number[0])->domain;

For the sake of readability I would like to leave parent variable
and assign it beforehand somewhere upper in the code.

Also, can irq_get_irq_data() return NULL? Needs a comment on top
of that assignment or an additional check.

-- 
With Best Regards,
Andy Shevchenko