From patchwork Mon Aug 22 18:37:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 599332 Return-Path: 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 641CEC32774 for ; Mon, 22 Aug 2022 18:38:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237600AbiHVSiX (ORCPT ); Mon, 22 Aug 2022 14:38:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236531AbiHVSh4 (ORCPT ); Mon, 22 Aug 2022 14:37:56 -0400 Received: from mail.baikalelectronics.com (mail.baikalelectronics.com [87.245.175.230]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 9C6F22F67A; Mon, 22 Aug 2022 11:37:44 -0700 (PDT) Received: from mail (mail.baikal.int [192.168.51.25]) by mail.baikalelectronics.com (Postfix) with ESMTP id A7088DA9; Mon, 22 Aug 2022 21:40:51 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.baikalelectronics.com A7088DA9 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baikalelectronics.ru; s=mail; t=1661193651; bh=1w09WlHzsLJJ1Iix44RngaZfNGmBziRoxLwbJ26Cixk=; h=From:To:CC:Subject:Date:In-Reply-To:References:From; b=S8nTTgFaEUPw32poHVgVhp+HHIdD7manyGv9290LHKhLcnu6CZxJpF+4IK9SZ1wCn p2ke4lMIGoT0Xc6VcOlxQX2+oMTxONEm97LIgpODzKAq6Ifr/QJrTq2WPutIviHUw0 WjOrg8wANOnpWxFBshcldZ8t+pxvjKyyVTpjLA2U= Received: from localhost (192.168.168.10) by mail (192.168.51.25) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Mon, 22 Aug 2022 21:37:37 +0300 From: Serge Semin To: Damien Le Moal , Hans de Goede , Jens Axboe , Hannes Reinecke CC: Serge Semin , Serge Semin , Alexey Malahov , Pavel Parkhomenko , Rob Herring , Krzysztof Kozlowski , , , Subject: [PATCH v7 08/23] ata: libahci_platform: Sanity check the DT child nodes number Date: Mon, 22 Aug 2022 21:37:13 +0300 Message-ID: <20220822183728.24434-9-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20220822183728.24434-1-Sergey.Semin@baikalelectronics.ru> References: <20220822183728.24434-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Having greater than AHCI_MAX_PORTS (32) ports detected isn't that critical from the further AHCI-platform initialization point of view since exceeding the ports upper limit will cause allocating more resources than will be used afterwards. But detecting too many child DT-nodes doesn't seem right since it's very unlikely to have it on an ordinary platform. In accordance with the AHCI specification there can't be more than 32 ports implemented at least due to having the CAP.NP field of 5 bits wide and the PI register of dword size. Thus if such situation is found the DTB must have been corrupted and the data read from it shouldn't be reliable. Let's consider that as an erroneous situation and halt further resources allocation. Note it's logically more correct to have the nports set only after the initialization value is checked for being sane. So while at it let's make sure nports is assigned with a correct value. Signed-off-by: Serge Semin Reviewed-by: Hannes Reinecke --- Changelog v2: - Drop the else word from the child_nodes value checking if-else-if statement (@Damien) and convert the after-else part into the ternary operator-based statement. Changelog v4: - Fix some logical mistakes in the patch log. (@Sergei Shtylyov) - Replace "?:" operator with if-else statement. (@Damien) --- drivers/ata/libahci_platform.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c index 814804582d1d..579039956917 100644 --- a/drivers/ata/libahci_platform.c +++ b/drivers/ata/libahci_platform.c @@ -451,14 +451,24 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev, } } - hpriv->nports = child_nodes = of_get_child_count(dev->of_node); + /* + * Too many sub-nodes most likely means having something wrong with + * the firmware. + */ + child_nodes = of_get_child_count(dev->of_node); + if (child_nodes > AHCI_MAX_PORTS) { + rc = -EINVAL; + goto err_out; + } /* * If no sub-node was found, we still need to set nports to * one in order to be able to use the * ahci_platform_[en|dis]able_[phys|regulators] functions. */ - if (!child_nodes) + if (child_nodes) + hpriv->nports = child_nodes; + else hpriv->nports = 1; hpriv->phys = devm_kcalloc(dev, hpriv->nports, sizeof(*hpriv->phys), GFP_KERNEL);