From patchwork Mon Apr 26 06:56:18 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tudor Ambarus X-Patchwork-Id: 12223929 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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 6EE5CC433B4 for ; Mon, 26 Apr 2021 06:56:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D0B360698 for ; Mon, 26 Apr 2021 06:56:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232053AbhDZG5M (ORCPT ); Mon, 26 Apr 2021 02:57:12 -0400 Received: from esa.microchip.iphmx.com ([68.232.153.233]:23292 "EHLO esa.microchip.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231616AbhDZG5L (ORCPT ); Mon, 26 Apr 2021 02:57:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1619420190; x=1650956190; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=uhDMDx6U8lKJACDDMg5wJ1xGShyMkk8ZFuePWaxHS1A=; b=I4NZFXczk40EQQ/Nhzl1I86VCKQr30BOqZ7Yd6HdL+tmHgFqi2S4iRg2 Jdd1ubPhMpCigXqHdGxDpi95Dt6UPX04yu6gw/7Du3wv0HGvfEbFQdaaW J95xJALTAQD3GzuxkUJ2j42dAITlaXIVllyioECvofvpzIUbCl0tH8+c+ mFCBR/mopW+CTS+8a3sluYkQtDlqBeDoy1qHwUVxU7UUlgvS8FxgXpdgO 0shaefzdjS5nTI1O8PXVyPF0FTuGy5aNjSAyacu1QALLLqz5kywUMd36X RzA6FcDQRJiZjV3E/8eqdLAcUKkqLfG1dH6DlnY+OugJsGRZ8KfQ4xvz5 w==; IronPort-SDR: eQx0XRS0qdgNtEscfcMgNylm24Yn6OdQCsMYQ/JM+r0a2OLPJWPoIAGuTJkX2E7JJ4azYberSY pTbQTH3KHNSQBuPHfR3uiIZ0ECAkZsAOLTnDm1rUpmG16AOf/oXI1Cs3iuuhuXANXlgHO5C2LI qGON2LKbum09IQQUT62FJeOo5mxoQKMiFq7fDViWaZXqT9uTgxAsu6vSJGOwb9Zm72sova0vMf 5qecgKuyfyeYMMhpsZway34KiQkqBgdq2xm881kQvgLvvktY53qH52eq/Au5msKIZ0Q2KCbK5l kCs= X-IronPort-AV: E=Sophos;i="5.82,251,1613458800"; d="scan'208";a="118343164" Received: from smtpout.microchip.com (HELO email.microchip.com) ([198.175.253.82]) by esa3.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 25 Apr 2021 23:56:27 -0700 Received: from chn-vm-ex03.mchp-main.com (10.10.85.151) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Sun, 25 Apr 2021 23:56:27 -0700 Received: from ROB-ULT-M18064N.mchp-main.com (10.10.115.15) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server id 15.1.2176.2 via Frontend Transport; Sun, 25 Apr 2021 23:56:20 -0700 From: Tudor Ambarus To: , , , , , , , , , , , , , , , , , , CC: , , , , , , , , , , , Tudor Ambarus , Marek Szyprowski Subject: [PATCH v2] clk: Skip clk provider registration when np is NULL Date: Mon, 26 Apr 2021 09:56:18 +0300 Message-ID: <20210426065618.588144-1-tudor.ambarus@microchip.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org 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 Reviewed-by: Saravana Kannan Reviewed-by: Nicolas Saenz Julienne Tested-by: Guenter Roeck Tested-by: Nathan Chancellor --- 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) {