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=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 529DFC433B4 for ; Mon, 10 May 2021 19:36:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 275ED611C2 for ; Mon, 10 May 2021 19:36:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230342AbhEJThy (ORCPT ); Mon, 10 May 2021 15:37:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230002AbhEJThx (ORCPT ); Mon, 10 May 2021 15:37:53 -0400 Received: from mail-oi1-x22a.google.com (mail-oi1-x22a.google.com [IPv6:2607:f8b0:4864:20::22a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72466C061574; Mon, 10 May 2021 12:36:48 -0700 (PDT) Received: by mail-oi1-x22a.google.com with SMTP id l6so16876867oii.1; Mon, 10 May 2021 12:36:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=rfwM6aeV64dlStCtynVwqpYhrKx+20fvdPRxkUUNoPk=; b=mxmiFt5qvY4oygWWBZxPyrzPAzIDNPiRcZSHCSYNuvlWGg8DdQseRAuHq9FSY4Tulj rTPDmvc2kJn1gm/Rc5Oyhvk22cnWgQ6DwjLFryi8ks3TwScNLTffiDchRZYJGv7cU0Ho 3cQ/72SWBHLm95nxpzNwLYuBEnTRnMg7Wjx7k1FQcwJ+yXpiErHlCMIU/wENp432qolY XsgfAxICnVrKS2y6S44pXIiBJoJZ+F13bL9LW3esNjjfCmViHQj55iiCYPRwZswAF4EO gIG6z/C2KJGqNXH2ElAzW9TWhgwYULSpttiV0EBleBsYBCgEjnYYioHiwotB8K0Rb37c uzJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=rfwM6aeV64dlStCtynVwqpYhrKx+20fvdPRxkUUNoPk=; b=hE0ItELCGgYlU4JX0txKaZQElbOT+i+fYQnIeX18Wg5rEdUdU08YNWCrNoV1BUT1Fz poZi8O6HsJVGYA90f0Ijh0ssHGpuK9S2LhgLriUD3SM6Cn7C7hhiTfseSVuei+VeEFe1 w2URoWGAfO4SPPoj4VZtbk30jlMQMyjrnxfUUYvfUFqaP/peHOPbAT1XXeOprsZMzMRn Vxfp+HaDtYmVvaqzBdpsVikXjSYBOoCbjv+dSqSSdK52n2RNvoY8+hioUf7oQ563Zevl KEHCLP/cdmDNLbNkZp9jJKKYRkCwiwRmkHjK23BOLVVZmy1XX6DCeK9DyDjj31jUce5A AV4w== X-Gm-Message-State: AOAM530OwcOcXZrZJPXLvVzEzQ8yj4ljIxkXQm+uKs4V0EqClhVATGdU CW2rHROXaTPnYPf6Vq000Yw= X-Google-Smtp-Source: ABdhPJz99SSWF74iI7aVgrfSha6fpI7t5Ox7OPhvT9ZInZpyUwZvMG07nJMrZkS9zEDf/bXgZ7WPdQ== X-Received: by 2002:aca:4004:: with SMTP id n4mr19028827oia.89.1620675407817; Mon, 10 May 2021 12:36:47 -0700 (PDT) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id g11sm288735oif.27.2021.05.10.12.36.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 May 2021 12:36:47 -0700 (PDT) Sender: Guenter Roeck Date: Mon, 10 May 2021 12:36:45 -0700 From: Guenter Roeck To: Tudor Ambarus Cc: gregkh@linuxfoundation.org, rafael@kernel.org, mturquette@baylibre.com, sboyd@kernel.org, nsaenz@kernel.org, maxime@cerno.tech, khilman@kernel.org, ulf.hansson@linaro.org, len.brown@intel.com, pavel@ucw.cz, robh+dt@kernel.org, frowand.list@gmail.com, maz@kernel.org, tglx@linutronix.de, saravanak@google.com, geert@linux-m68k.org, nsaenzjulienne@suse.de, guillaume.tucker@collabora.com, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, corbet@lwn.net, nicolas.ferre@microchip.com, claudiu.beznea@microchip.com, linux-doc@vger.kernel.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-acpi@vger.kernel.org, kernel-team@android.com, linux-rpi-kernel@lists.infradead.org, Marek Szyprowski Subject: Re: [PATCH v2] clk: Skip clk provider registration when np is NULL Message-ID: <20210510193645.GA3920948@roeck-us.net> References: <20210426065618.588144-1-tudor.ambarus@microchip.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210426065618.588144-1-tudor.ambarus@microchip.com> Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Mon, Apr 26, 2021 at 09:56:18AM +0300, Tudor Ambarus wrote: > commit 6579c8d97ad7 ("clk: Mark fwnodes when their clock provider is added") > revealed that clk/bcm/clk-raspberrypi.c driver calls > devm_of_clk_add_hw_provider(), with a NULL dev->of_node, which resulted in a > NULL pointer dereference in of_clk_add_hw_provider() when calling > fwnode_dev_initialized(). > > Returning 0 is reducing the if conditions in driver code and is being > consistent with the CONFIG_OF=n inline stub that returns 0 when CONFIG_OF > is disabled. The downside is that drivers will maybe register clkdev lookups > when they don't need to and waste some memory. > > Reported-by: Marek Szyprowski > Fixes: 6579c8d97ad7 ("clk: Mark fwnodes when their clock provider is added") > Fixes: 3c9ea42802a1 ("clk: Mark fwnodes when their clock provider is added/removed") > Signed-off-by: Tudor Ambarus > Reviewed-by: Stephen Boyd Tested-by: Guenter Roeck > --- > v2: > - s/return 0;/return; in void of_clk_del_provider() > - add second fixes tag and Stephen's R-b tag > The opinions on whether to return an error or zero were split. Returning 0 > and skipping the logic was considered safer as we don't know for sure if > other drivers are affected. See: > https://lore.kernel.org/lkml/d24bebc5-0f78-021f-293f-e58defa32531@samsung.com/ > https://lore.kernel.org/lkml/20210423171335.262316-1-tudor.ambarus@microchip.com/ > > drivers/clk/clk.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index a3b30f7de2ef..b47460b40d14 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -4552,6 +4552,9 @@ int of_clk_add_provider(struct device_node *np, > struct of_clk_provider *cp; > int ret; > > + if (!np) > + return 0; > + > cp = kzalloc(sizeof(*cp), GFP_KERNEL); > if (!cp) > return -ENOMEM; > @@ -4591,6 +4594,9 @@ int of_clk_add_hw_provider(struct device_node *np, > struct of_clk_provider *cp; > int ret; > > + if (!np) > + return 0; > + > cp = kzalloc(sizeof(*cp), GFP_KERNEL); > if (!cp) > return -ENOMEM; > @@ -4688,6 +4694,9 @@ void of_clk_del_provider(struct device_node *np) > { > struct of_clk_provider *cp; > > + if (!np) > + return; > + > mutex_lock(&of_clk_mutex); > list_for_each_entry(cp, &of_clk_providers, link) { > if (cp->node == np) { > -- > 2.25.1 >