From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1F0B8421259; Mon, 5 Oct 2026 23:37:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791243481; cv=none; b=dk2xq6pjw2/tEwj86itR0hVaz2zW9TS66O7Dx0TtuxItJcnD+GaAQk1LVIyXP3KCkc1pw9HCenGNbS/TQ9rGvw268k2xfjxI+hrmdpyAKiFTx5fHqy72jaBlfuFdCdYjmGYuKzrZMSQ7lgmyTSiscWtKw3uJ0LGwld8AtuWJw5E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791243481; c=relaxed/simple; bh=wHhFpuZX54/313lqoel9OUyPQIGXxcFUhf5FAjdR2Qo=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=D9Xwui4rQHqPLu12IpigbNCVN6N/N4fq++CFnX6xZiL30J8NvyKMXU4fKfWKQTVdP4MC40HmR/42yAtccJ6NnI1EtLhebQTAdkhSTY5ApzAyoE0V0mKqvhhrbU9nr/3dW10fH8ZLbsnqolZgA397utASdbqnBY9mVnm7rgy1qOU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oVafL/jF; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oVafL/jF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7DF151F000FF; Mon, 5 Oct 2026 23:37:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791243479; bh=F9mj9hBOR4INL/J0dw4RHuFc+zlALPDdCwtt8rXEwx4=; h=Date:From:To:Cc:Subject:In-Reply-To; b=oVafL/jF7wbNV8UIs9FpvDi7Q24YuKgnGDwngw1i7TpMYQq6KjEomG+s21lza/nYs KfHiTikEFtwfozV0j3MOGC6NBGuz2dHMHXaw21Ae5dxHtmRxZtmJ2PHDFQpcRNT6nh Kja2MveAf51QPd7G+apbw2fajqK6FojV4WEUPzcM/pjeHRaCRASko1ELi2zMDvKSMQ I9r4oICbQVlzMQyRxvDHCO2Zns7d87s4zYo3HSyzPEbyoNtAF4MLRT2yZkab8QYm3L R+eXCOs71vZAgLtorZlk2w4zB22xuBfrWKkpZ9AGkPlF2zENaunLXZ8TsKLqXr3z20 NlDDc1TapaLjA== Date: Mon, 5 Oct 2026 18:37:58 -0500 From: Bjorn Helgaas To: Marek Vasut Cc: linux-pci@vger.kernel.org, Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Bjorn Helgaas , Geert Uytterhoeven , Lad Prabhakar , Lorenzo Pieralisi , Magnus Damm , Manivannan Sadhasivam , Rob Herring , Yoshihiro Shimoda , linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org Subject: Re: [PATCH] PCI: rcar-host: Validate IO/MEM resource count in DT ranges property Message-ID: <20261005233758.GA646371@bhelgaas> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20261003073701.354551-1-marek.vasut+renesas@mailbox.org> On Sat, Oct 03, 2026 at 09:35:59AM +0200, Marek Vasut wrote: > The R-Car Gen3 PCIEC controller supports up to 4 memory area mappings. > Count the IO and MEM ranges described in DT 'ranges' property of the > controller DT node, and in case there are more than 4, refuse to probe > the controller driver, because such DT does not describe valid hardware > configuration. Do the IO and MEM counting early to avoid controller > configuration rollback in case of failure. > > Fixes: 5d2917d469fa ("PCI: rcar: Convert to DT resource parsing API") > Signed-off-by: Marek Vasut > --- > Cc: "Krzysztof Wilczyński" > Cc: Bjorn Helgaas > Cc: Geert Uytterhoeven > Cc: Lad Prabhakar > Cc: Lorenzo Pieralisi > Cc: Magnus Damm > Cc: Manivannan Sadhasivam > Cc: Rob Herring > Cc: Yoshihiro Shimoda > Cc: linux-kernel@vger.kernel.org > Cc: linux-pci@vger.kernel.org > Cc: linux-renesas-soc@vger.kernel.org > --- > drivers/pci/controller/pcie-rcar-host.c | 31 +++++++++++++++++++++++++ > 1 file changed, 31 insertions(+) > > diff --git a/drivers/pci/controller/pcie-rcar-host.c b/drivers/pci/controller/pcie-rcar-host.c > index cd9171eebc289..4bcc8c3051ac4 100644 > --- a/drivers/pci/controller/pcie-rcar-host.c > +++ b/drivers/pci/controller/pcie-rcar-host.c > @@ -341,6 +341,32 @@ static void rcar_pcie_force_speedup(struct rcar_pcie *pcie) > (macsr & LINK_SPEED) == LINK_SPEED_5_0GTS ? "5" : "2.5"); > } > > +static int rcar_pcie_validate_resource_count(struct rcar_pcie_host *host) > +{ > + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(host); > + struct rcar_pcie *pcie = &host->pcie; > + struct resource_entry *win; > + int i = 0; > + > + resource_list_for_each_entry(win, &bridge->windows) { > + struct resource *res = win->res; > + unsigned long type = resource_type(res); > + > + if (!res->flags) > + continue; > + > + if (type == IORESOURCE_IO || type == IORESOURCE_MEM) > + i++; > + > + if (i > RCAR_PCI_MAX_RESOURCES) > + return dev_err_probe(pcie->dev, -ENOSPC, > + "Too many IO/MEM entries in DT 'ranges' property, limit is %d\n", > + RCAR_PCI_MAX_RESOURCES); > + } > + > + return 0; > +} > + > static void rcar_pcie_hw_enable(struct rcar_pcie_host *host) > { > struct rcar_pcie *pcie = &host->pcie; > @@ -947,6 +973,11 @@ static int rcar_pcie_probe(struct platform_device *pdev) > host = pci_host_bridge_priv(bridge); > pcie = &host->pcie; > pcie->dev = dev; > + > + err = rcar_pcie_validate_resource_count(host); > + if (err) > + return err; I guess you did this here to avoid rolling back controller config, but the code would be a lot more readable if it checked the index at the point where it might exceed the array bound, e.g., (I think) in rcar_pcie_set_outbound(). This is for an invalid DT, which is unlikely. What if rcar_pcie_set_outbound() just printed a warning and ignored any excess windows? > platform_set_drvdata(pdev, host); > > for (i = 0; i < ARRAY_SIZE(rcar_pcie_supplies); i++) { > -- > 2.53.0 >