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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF430C43334 for ; Tue, 14 Jun 2022 08:23:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351701AbiFNIXr (ORCPT ); Tue, 14 Jun 2022 04:23:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240449AbiFNIXl (ORCPT ); Tue, 14 Jun 2022 04:23:41 -0400 Received: from esa2.hgst.iphmx.com (esa2.hgst.iphmx.com [68.232.143.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 573B4369DD for ; Tue, 14 Jun 2022 01:23:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1655195020; x=1686731020; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=MmvF2pvUPJk+l0G2cFMgXO+laIHLHX4qzgsWbZlC+FM=; b=QCIItuFAQcpJ1jQdKdCedubREQk3Uf0YxXoD+NxcSPhTsdcQK28xcDWC fG/iRDU2OikBjLbRAo+xvIEDiRpIIBVDuXfjTrMcB4hK+SVfCzj6ccRC+ PZQ5SNQ0nZ82Gi20HuLhXXkjCIS9Mm0gUs0f0gONfsWMmT+l2cFkS1lIF v/O3BHzfhLWI5ycYYeIquIcY9xnAgtxaUPr6nw1EKqXroacPRtaVF7G+D oWKf+yVo1rfFeO5WJfQU/dPGBjPMt5CfgCzlMMl0zaNPcHkn4JIW60Mx9 tTyexjWhpdoxGA8hWvkW2ceuyjct5pAENelFwYoI6TVFloRW5YgAXMZSJ w==; X-IronPort-AV: E=Sophos;i="5.91,299,1647273600"; d="scan'208";a="307384173" Received: from uls-op-cesaip01.wdc.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 14 Jun 2022 16:23:38 +0800 IronPort-SDR: x8VsxMSoEtHJ9z9xhnCmlOfaoMtUeTBS/0PrBvYLU/YYlB7De6BiSIBRBkvIKbVYZOiyy6WYWG ix48vVKRclQNWzeVIhEF9iL0YnT3Im5qgOBITffq2S0jEA0o46ynfNVH4MNU9HTbTxxYBU3BiW Lzgus0CB9rdVbYO2XZ1uKkDs1vY7OBaatKQglZwksSxVlLKxgc50qVjiTCId2Eh2YT999QMi8u 4eIcCdgLaxNHllYFZgUrrFr30UJY51THBRpfzzovl/kr8c9WtLRn2dvQtyCFdhMq/ZsLnaZlc6 9FHGttycOHL4Eq1alzXq63Ow Received: from uls-op-cesaip01.wdc.com ([10.248.3.36]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 14 Jun 2022 00:46:36 -0700 IronPort-SDR: CnM/PZFAoc5FjHoRf8tI5FhjmHIiEI9Mvt++8CHnWhrTHPWTsENWNjBgIPnWtM6O7oTYnNVVk3 p2XoAznCxP+5ywDAfEscefPZx8hJLfdeIUAWodNhecVF4muUMeAspukuE/KOqZjy0DBJc8Ze7b aIeGUiGDIY1jOlRGdgeS/BOzQuJs84TLWXPViFW/X7Jpou0hm8NJ11DiMLvHTZXodlqJm0cZF0 S8/ycYWlPW3MIt3hXStPJRBicAaOq0QCr4wq2Xy/+JImk41CUCXx7711Px0r9OWcOp4CwAslc2 8xE= WDCIronportException: Internal Received: from usg-ed-osssrv.wdc.com ([10.3.10.180]) by uls-op-cesaip01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 14 Jun 2022 01:23:38 -0700 Received: from usg-ed-osssrv.wdc.com (usg-ed-osssrv.wdc.com [127.0.0.1]) by usg-ed-osssrv.wdc.com (Postfix) with ESMTP id 4LMhKP4V1lz1SVp4 for ; Tue, 14 Jun 2022 01:23:37 -0700 (PDT) Authentication-Results: usg-ed-osssrv.wdc.com (amavisd-new); dkim=pass reason="pass (just generated, assumed good)" header.d=opensource.wdc.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d= opensource.wdc.com; h=content-transfer-encoding:content-type :in-reply-to:organization:from:references:to:content-language :subject:user-agent:mime-version:date:message-id; s=dkim; t= 1655195016; x=1657787017; bh=MmvF2pvUPJk+l0G2cFMgXO+laIHLHX4qzgs WbZlC+FM=; b=cZgBSiPGopdTy3/f3GexXyiQJGRLQCM5ePdjjqM+Mw5uensNmg5 02s/0vZmih6XWX3v/F4UyynmVBuVpMJ2CVW7sEVuq8T7d/YwePnO7JHp8VfZ+w+d JSNT7ngTk1d/PUJ8YQ40msTkvWOXYLjJdvPXV+7PuO2TLoVRNiMbnLgpLSZnHyv7 A6BHlclzYoVKYxydhG30lwNfoZiVED4rP/waEx06tT1RuVq+FDfldH2bsjCGpntQ Bwwu1aIOQ3ZgrRiHm5hSpQEhLTjh1okSo1jCfDt5uC9ujFkmQMc9zxFNcNlFT0N6 aEZ0ufp9l94E4+baq7rH9HpKd+88a+Era9g== X-Virus-Scanned: amavisd-new at usg-ed-osssrv.wdc.com Received: from usg-ed-osssrv.wdc.com ([127.0.0.1]) by usg-ed-osssrv.wdc.com (usg-ed-osssrv.wdc.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id VTSbvKWi_Kjf for ; Tue, 14 Jun 2022 01:23:36 -0700 (PDT) Received: from [10.225.163.77] (unknown [10.225.163.77]) by usg-ed-osssrv.wdc.com (Postfix) with ESMTPSA id 4LMhKM12P2z1Rvlc; Tue, 14 Jun 2022 01:23:34 -0700 (PDT) Message-ID: Date: Tue, 14 Jun 2022 17:23:33 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Subject: Re: [PATCH v4 08/23] ata: libahci_platform: Sanity check the DT child nodes number Content-Language: en-US To: Serge Semin , Hans de Goede , Jens Axboe , Hannes Reinecke Cc: Serge Semin , Alexey Malahov , Pavel Parkhomenko , Rob Herring , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org References: <20220610081801.11854-1-Sergey.Semin@baikalelectronics.ru> <20220610081801.11854-9-Sergey.Semin@baikalelectronics.ru> From: Damien Le Moal Organization: Western Digital Research In-Reply-To: <20220610081801.11854-9-Sergey.Semin@baikalelectronics.ru> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/10/22 17:17, Serge Semin wrote: > 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) > --- > drivers/ata/libahci_platform.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c > index 814804582d1d..8aed7b29c7ab 100644 > --- a/drivers/ata/libahci_platform.c > +++ b/drivers/ata/libahci_platform.c > @@ -451,15 +451,22 @@ 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) > - hpriv->nports = 1; > + hpriv->nports = child_nodes ?: 1; This change is not necessary and makes the code far less easy to read. > > hpriv->phys = devm_kcalloc(dev, hpriv->nports, sizeof(*hpriv->phys), GFP_KERNEL); > if (!hpriv->phys) { -- Damien Le Moal Western Digital Research